<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:74adcae8-3aca-4fbf-adae-133cc93727a0,g:ef7020bf-6d1f-4a12-865b-547d84d01950-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:kop="http://www.koppers.com/20251231" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2024-01-31" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.koppers.com/20251231">
  <xs:import namespace="http://fasb.org/srt/2025" schemaLocation="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap/2025" schemaLocation="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2024-01-31" schemaLocation="https://www.xbrl.org/dtr/type/2024-01-31/types.xsd"/>
  <xs:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/country/2025" schemaLocation="https://xbrl.sec.gov/country/2025/country-2025.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/cyd-af-sub/2025" schemaLocation="https://xbrl.sec.gov/cyd/2025/cyd-af-sub-2025.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/dei/2025" schemaLocation="https://xbrl.sec.gov/dei/2025/dei-2025.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/ecd/2025" schemaLocation="https://xbrl.sec.gov/ecd/2025/ecd-2025.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/stpr/2025" schemaLocation="https://xbrl.sec.gov/stpr/2025/stpr-2025.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="kop-20251231_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="kop-20251231_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="kop-20251231_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="kop-20251231_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="CoverPage" roleURI="http://www.koppers.com/role/CoverPage">
        <link:definition>0000001 - Document - Cover Page</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AuditInformation" roleURI="http://www.koppers.com/role/AuditInformation">
        <link:definition>0000002 - Document - Audit Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDSTATEMENTOFOPERATIONS" roleURI="http://www.koppers.com/role/CONSOLIDATEDSTATEMENTOFOPERATIONS">
        <link:definition>9952151 - Statement - CONSOLIDATED STATEMENT OF OPERATIONS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDSTATEMENTOFCOMPREHENSIVEINCOME" roleURI="http://www.koppers.com/role/CONSOLIDATEDSTATEMENTOFCOMPREHENSIVEINCOME">
        <link:definition>9952152 - Statement - CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDSTATEMENTOFCOMPREHENSIVEINCOMEParenthetical" roleURI="http://www.koppers.com/role/CONSOLIDATEDSTATEMENTOFCOMPREHENSIVEINCOMEParenthetical">
        <link:definition>9952153 - Statement - CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDBALANCESHEET" roleURI="http://www.koppers.com/role/CONSOLIDATEDBALANCESHEET">
        <link:definition>9952154 - Statement - CONSOLIDATED BALANCE SHEET</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDBALANCESHEETParenthetical" roleURI="http://www.koppers.com/role/CONSOLIDATEDBALANCESHEETParenthetical">
        <link:definition>9952155 - Statement - CONSOLIDATED BALANCE SHEET (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDSTATEMENTOFCASHFLOWS" roleURI="http://www.koppers.com/role/CONSOLIDATEDSTATEMENTOFCASHFLOWS">
        <link:definition>9952156 - Statement - CONSOLIDATED STATEMENT OF CASH FLOWS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITY" roleURI="http://www.koppers.com/role/CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITY">
        <link:definition>9952157 - Statement - CONSOLIDATED STATEMENT OF SHAREHOLDERS&#8217; EQUITY</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITYParenthetical" roleURI="http://www.koppers.com/role/CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITYParenthetical">
        <link:definition>9952158 - Statement - CONSOLIDATED STATEMENT OF SHAREHOLDERS&#8217; EQUITY (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DescriptionofBusiness" roleURI="http://www.koppers.com/role/DescriptionofBusiness">
        <link:definition>9952159 - Disclosure - Description of Business</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SummaryofSignificantAccountingPolicies" roleURI="http://www.koppers.com/role/SummaryofSignificantAccountingPolicies">
        <link:definition>9952160 - Disclosure - Summary of Significant Accounting Policies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AcquisitionsandRestructuring" roleURI="http://www.koppers.com/role/AcquisitionsandRestructuring">
        <link:definition>9952161 - Disclosure - Acquisitions and Restructuring</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommonStockandSeniorConvertiblePreferredStock" roleURI="http://www.koppers.com/role/CommonStockandSeniorConvertiblePreferredStock">
        <link:definition>9952162 - Disclosure - Common Stock and Senior Convertible Preferred Stock</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DerivativeFinancialInstruments" roleURI="http://www.koppers.com/role/DerivativeFinancialInstruments">
        <link:definition>9952163 - Disclosure - Derivative Financial Instruments</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueMeasurements" roleURI="http://www.koppers.com/role/FairValueMeasurements">
        <link:definition>9952164 - Disclosure - Fair Value Measurements</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsandDividendsperCommonShare" roleURI="http://www.koppers.com/role/EarningsandDividendsperCommonShare">
        <link:definition>9952165 - Disclosure - Earnings and Dividends per Common Share</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockbasedCompensation" roleURI="http://www.koppers.com/role/StockbasedCompensation">
        <link:definition>9952166 - Disclosure - Stock-based Compensation</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformation" roleURI="http://www.koppers.com/role/SegmentInformation">
        <link:definition>9952167 - Disclosure - Segment Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxes" roleURI="http://www.koppers.com/role/IncomeTaxes">
        <link:definition>9952168 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Inventories" roleURI="http://www.koppers.com/role/Inventories">
        <link:definition>9952169 - Disclosure - Inventories</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PropertyPlantandEquipment" roleURI="http://www.koppers.com/role/PropertyPlantandEquipment">
        <link:definition>9952170 - Disclosure - Property, Plant and Equipment</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GoodwillandIntangibleAssets" roleURI="http://www.koppers.com/role/GoodwillandIntangibleAssets">
        <link:definition>9952171 - Disclosure - Goodwill and Intangible Assets</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlans" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlans">
        <link:definition>9952172 - Disclosure - Pensions and Post-Retirement Benefit Plans</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Debt" roleURI="http://www.koppers.com/role/Debt">
        <link:definition>9952173 - Disclosure - Debt</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Leases" roleURI="http://www.koppers.com/role/Leases">
        <link:definition>9952174 - Disclosure - Leases</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsandContingentLiabilities" roleURI="http://www.koppers.com/role/CommitmentsandContingentLiabilities">
        <link:definition>9952175 - Disclosure - Commitments and Contingent Liabilities</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTS" roleURI="http://www.koppers.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTS">
        <link:definition>9952176 - Disclosure - SCHEDULE II &#8211; VALUATION AND QUALIFYING ACCOUNTS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SummaryofSignificantAccountingPoliciesPolicies" roleURI="http://www.koppers.com/role/SummaryofSignificantAccountingPoliciesPolicies">
        <link:definition>9955511 - Disclosure - Summary of Significant Accounting Policies (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SummaryofSignificantAccountingPoliciesTables" roleURI="http://www.koppers.com/role/SummaryofSignificantAccountingPoliciesTables">
        <link:definition>9955512 - Disclosure - Summary of Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AcquisitionsandRestructuringTables" roleURI="http://www.koppers.com/role/AcquisitionsandRestructuringTables">
        <link:definition>9955513 - Disclosure - Acquisitions and Restructuring (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommonStockandSeniorConvertiblePreferredStockTables" roleURI="http://www.koppers.com/role/CommonStockandSeniorConvertiblePreferredStockTables">
        <link:definition>9955514 - Disclosure - Common Stock and Senior Convertible Preferred Stock (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DerivativeFinancialInstrumentsTables" roleURI="http://www.koppers.com/role/DerivativeFinancialInstrumentsTables">
        <link:definition>9955515 - Disclosure - Derivative Financial Instruments (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueMeasurementsTables" roleURI="http://www.koppers.com/role/FairValueMeasurementsTables">
        <link:definition>9955516 - Disclosure - Fair Value Measurements (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsandDividendsperCommonShareTables" roleURI="http://www.koppers.com/role/EarningsandDividendsperCommonShareTables">
        <link:definition>9955517 - Disclosure - Earnings and Dividends per Common Share (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockbasedCompensationTables" roleURI="http://www.koppers.com/role/StockbasedCompensationTables">
        <link:definition>9955518 - Disclosure - Stock-based Compensation (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformationTables" roleURI="http://www.koppers.com/role/SegmentInformationTables">
        <link:definition>9955519 - Disclosure - Segment Information (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesTables" roleURI="http://www.koppers.com/role/IncomeTaxesTables">
        <link:definition>9955520 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InventoriesTables" roleURI="http://www.koppers.com/role/InventoriesTables">
        <link:definition>9955521 - Disclosure - Inventories (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PropertyPlantandEquipmentTables" roleURI="http://www.koppers.com/role/PropertyPlantandEquipmentTables">
        <link:definition>9955522 - Disclosure - Property, Plant and Equipment (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GoodwillandIntangibleAssetsTables" roleURI="http://www.koppers.com/role/GoodwillandIntangibleAssetsTables">
        <link:definition>9955523 - Disclosure - Goodwill and Intangible Assets (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlansTables" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlansTables">
        <link:definition>9955524 - Disclosure - Pensions and Post-Retirement Benefit Plans (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DebtTables" roleURI="http://www.koppers.com/role/DebtTables">
        <link:definition>9955525 - Disclosure - Debt (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesTables" roleURI="http://www.koppers.com/role/LeasesTables">
        <link:definition>9955526 - Disclosure - Leases (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsandContingentLiabilitiesTables" roleURI="http://www.koppers.com/role/CommitmentsandContingentLiabilitiesTables">
        <link:definition>9955527 - Disclosure - Commitments and Contingent Liabilities (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DescriptionofBusinessDetails" roleURI="http://www.koppers.com/role/DescriptionofBusinessDetails">
        <link:definition>9955528 - Disclosure - Description of Business (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SummaryofSignificantAccountingPoliciesAdditionalInformationDetails" roleURI="http://www.koppers.com/role/SummaryofSignificantAccountingPoliciesAdditionalInformationDetails">
        <link:definition>9955529 - Disclosure - Summary of Significant Accounting Policies - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SummaryofSignificantAccountingPoliciesSummaryofCloudBasedSoftwareImplementationCostsDetails" roleURI="http://www.koppers.com/role/SummaryofSignificantAccountingPoliciesSummaryofCloudBasedSoftwareImplementationCostsDetails">
        <link:definition>9955530 - Disclosure - Summary of Significant Accounting Policies - Summary of Cloud-Based Software Implementation Costs (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SummaryofSignificantAccountingPoliciesSummaryofAssetRetirementObligationLiabilitiesDetails" roleURI="http://www.koppers.com/role/SummaryofSignificantAccountingPoliciesSummaryofAssetRetirementObligationLiabilitiesDetails">
        <link:definition>9955531 - Disclosure - Summary of Significant Accounting Policies - Summary of Asset Retirement Obligation Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AcquisitionsandRestructuringAdditionalInformationDetails" roleURI="http://www.koppers.com/role/AcquisitionsandRestructuringAdditionalInformationDetails">
        <link:definition>9955532 - Disclosure - Acquisitions and Restructuring - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AcquisitionsandRestructuringSummaryofPurchasePriceandEstimatedFairValueofAssetsAcquiredandLiabilitiesAssumedDetails" roleURI="http://www.koppers.com/role/AcquisitionsandRestructuringSummaryofPurchasePriceandEstimatedFairValueofAssetsAcquiredandLiabilitiesAssumedDetails">
        <link:definition>9955533 - Disclosure - Acquisitions and Restructuring - Summary of Purchase Price and Estimated Fair Value of Assets Acquired and Liabilities Assumed (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AcquisitionsandRestructuringSummaryofRestructuringActivitiesDetails" roleURI="http://www.koppers.com/role/AcquisitionsandRestructuringSummaryofRestructuringActivitiesDetails">
        <link:definition>9955534 - Disclosure - Acquisitions and Restructuring - Summary of Restructuring Activities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AcquisitionsandRestructuringSummaryofDetailsofPlantClosuresandRestructuringLiabilitiesDetails" roleURI="http://www.koppers.com/role/AcquisitionsandRestructuringSummaryofDetailsofPlantClosuresandRestructuringLiabilitiesDetails">
        <link:definition>9955535 - Disclosure - Acquisitions and Restructuring - Summary of Details of Plant Closures and Restructuring Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommonStockandSeniorConvertiblePreferredStockAdditionalInformationDetails" roleURI="http://www.koppers.com/role/CommonStockandSeniorConvertiblePreferredStockAdditionalInformationDetails">
        <link:definition>9955536 - Disclosure - Common Stock and Senior Convertible Preferred Stock - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommonStockandSeniorConvertiblePreferredStockSummaryofChangesinCommonStockandTreasuryStockDetails" roleURI="http://www.koppers.com/role/CommonStockandSeniorConvertiblePreferredStockSummaryofChangesinCommonStockandTreasuryStockDetails">
        <link:definition>9955537 - Disclosure - Common Stock and Senior Convertible Preferred Stock - Summary of Changes in Common Stock and Treasury Stock (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DerivativeFinancialInstrumentsAdditionalInformationDetails" roleURI="http://www.koppers.com/role/DerivativeFinancialInstrumentsAdditionalInformationDetails">
        <link:definition>9955538 - Disclosure - Derivative Financial Instruments - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DerivativeFinancialInstrumentsSummaryofFairValueofOutstandingDerivativecontractsDetails" roleURI="http://www.koppers.com/role/DerivativeFinancialInstrumentsSummaryofFairValueofOutstandingDerivativecontractsDetails">
        <link:definition>9955539 - Disclosure - Derivative Financial Instruments - Summary of Fair Value of Outstanding Derivative contracts (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DerivativeFinancialInstrumentsSummaryofUnrealizedGainLossfromHedgingContractsWhereHedgeAccountingWasNotElectedDetails" roleURI="http://www.koppers.com/role/DerivativeFinancialInstrumentsSummaryofUnrealizedGainLossfromHedgingContractsWhereHedgeAccountingWasNotElectedDetails">
        <link:definition>9955540 - Disclosure - Derivative Financial Instruments - Summary of Unrealized (Gain) Loss from Hedging Contracts Where Hedge Accounting Was Not Elected (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DerivativeFinancialInstrumentsSummaryofOutstandingCopperSwapContractsDetails" roleURI="http://www.koppers.com/role/DerivativeFinancialInstrumentsSummaryofOutstandingCopperSwapContractsDetails">
        <link:definition>9955541 - Disclosure - Derivative Financial Instruments - Summary of Outstanding Copper Swap Contracts (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DerivativeFinancialInstrumentsSummaryofNetCurrencyUnitsOutstandingDetails" roleURI="http://www.koppers.com/role/DerivativeFinancialInstrumentsSummaryofNetCurrencyUnitsOutstandingDetails">
        <link:definition>9955542 - Disclosure - Derivative Financial Instruments - Summary of Net Currency Units Outstanding (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueMeasurementsDetails" roleURI="http://www.koppers.com/role/FairValueMeasurementsDetails">
        <link:definition>9955543 - Disclosure - Fair Value Measurements (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsandDividendsperCommonShareSummaryofComputationofBasicandDilutedEarningsperCommonShareDetails" roleURI="http://www.koppers.com/role/EarningsandDividendsperCommonShareSummaryofComputationofBasicandDilutedEarningsperCommonShareDetails">
        <link:definition>9955544 - Disclosure - Earnings and Dividends per Common Share - Summary of Computation of Basic and Diluted Earnings per Common Share (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsandDividendsperCommonShareAdditionalInformationDetails" roleURI="http://www.koppers.com/role/EarningsandDividendsperCommonShareAdditionalInformationDetails">
        <link:definition>9955545 - Disclosure - Earnings and Dividends per Common Share - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockbasedCompensationAdditionalInformationDetails" roleURI="http://www.koppers.com/role/StockbasedCompensationAdditionalInformationDetails">
        <link:definition>9955546 - Disclosure - Stock-based Compensation - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockbasedCompensationSummaryofStockOptionsAndPerformanceAwardFairValueAssumptionsDetails" roleURI="http://www.koppers.com/role/StockbasedCompensationSummaryofStockOptionsAndPerformanceAwardFairValueAssumptionsDetails">
        <link:definition>9955547 - Disclosure - Stock-based Compensation - Summary of Stock Options And Performance Award Fair Value Assumptions (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockbasedCompensationSummaryofPerformanceStockUnitsDetails" roleURI="http://www.koppers.com/role/StockbasedCompensationSummaryofPerformanceStockUnitsDetails">
        <link:definition>9955548 - Disclosure - Stock-based Compensation - Summary of Performance Stock Units (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockbasedCompensationSummaryofStatusandActivityofNonVestedStockAwardsDetails" roleURI="http://www.koppers.com/role/StockbasedCompensationSummaryofStatusandActivityofNonVestedStockAwardsDetails">
        <link:definition>9955549 - Disclosure - Stock-based Compensation - Summary of Status and Activity of Non-Vested Stock Awards (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockbasedCompensationSummaryofStatusandActivityofStockOptionsDetails" roleURI="http://www.koppers.com/role/StockbasedCompensationSummaryofStatusandActivityofStockOptionsDetails">
        <link:definition>9955550 - Disclosure - Stock-based Compensation - Summary of Status and Activity of Stock Options (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockbasedCompensationSummaryofStockBasedCompensationExpenseRecognizedDetails" roleURI="http://www.koppers.com/role/StockbasedCompensationSummaryofStockBasedCompensationExpenseRecognizedDetails">
        <link:definition>9955551 - Disclosure - Stock-based Compensation - Summary of Stock-Based Compensation Expense Recognized (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformationAdditionalInformationDetails" roleURI="http://www.koppers.com/role/SegmentInformationAdditionalInformationDetails">
        <link:definition>9955552 - Disclosure - Segment Information - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformationSummaryofSegmentRevenuesforSignificantProductLinesDetails" roleURI="http://www.koppers.com/role/SegmentInformationSummaryofSegmentRevenuesforSignificantProductLinesDetails">
        <link:definition>9955553 - Disclosure - Segment Information - Summary of Segment Revenues for Significant Product Lines (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformationSummaryofResultsofSegmentOperationsDetails" roleURI="http://www.koppers.com/role/SegmentInformationSummaryofResultsofSegmentOperationsDetails">
        <link:definition>9955554 - Disclosure - Segment Information - Summary of Results of Segment Operations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformationSummaryofTangibleandIntangibleAssetsbySegmentsDetails" roleURI="http://www.koppers.com/role/SegmentInformationSummaryofTangibleandIntangibleAssetsbySegmentsDetails">
        <link:definition>9955555 - Disclosure - Segment Information - Summary of Tangible and Intangible Assets by Segments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformationSummaryofRevenuesandLongLivedAssetsbyGeographicAreaDetails" roleURI="http://www.koppers.com/role/SegmentInformationSummaryofRevenuesandLongLivedAssetsbyGeographicAreaDetails">
        <link:definition>9955556 - Disclosure - Segment Information - Summary of Revenues and Long-Lived Assets by Geographic Area (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesSummaryofIncomeTaxProvisionDetails" roleURI="http://www.koppers.com/role/IncomeTaxesSummaryofIncomeTaxProvisionDetails">
        <link:definition>9955557 - Disclosure - Income Taxes - Summary of Income Tax Provision (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesSummaryofIncomeTaxProvisionDetails_1" roleURI="http://www.koppers.com/role/IncomeTaxesSummaryofIncomeTaxProvisionDetails_1">
        <link:definition>9955557 - Disclosure - Income Taxes - Summary of Income Tax Provision (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesSummaryofComponentsofCashPaidforIncomeTaxesDetails" roleURI="http://www.koppers.com/role/IncomeTaxesSummaryofComponentsofCashPaidforIncomeTaxesDetails">
        <link:definition>9955558 - Disclosure - Income Taxes - Summary of Components of Cash Paid for Income Taxes (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesSummaryofIncomeTaxesReconciledwithFederalStatutoryRateDetails" roleURI="http://www.koppers.com/role/IncomeTaxesSummaryofIncomeTaxesReconciledwithFederalStatutoryRateDetails">
        <link:definition>9955559 - Disclosure - Income Taxes - Summary of Income Taxes Reconciled with Federal Statutory Rate (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesAdditionalInformationDetails" roleURI="http://www.koppers.com/role/IncomeTaxesAdditionalInformationDetails">
        <link:definition>9955560 - Disclosure - Income Taxes - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesSummaryofDeferredTaxAssetsandLiabilitiesDetails" roleURI="http://www.koppers.com/role/IncomeTaxesSummaryofDeferredTaxAssetsandLiabilitiesDetails">
        <link:definition>9955561 - Disclosure - Income Taxes - Summary of Deferred Tax Assets and Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesSummaryofValuationAllowancesRecordedtoOffsetDeferredTaxAssetsDetails" roleURI="http://www.koppers.com/role/IncomeTaxesSummaryofValuationAllowancesRecordedtoOffsetDeferredTaxAssetsDetails">
        <link:definition>9955562 - Disclosure - Income Taxes - Summary of Valuation Allowances Recorded to Offset Deferred Tax Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncometaxesSummaryofUnrecognizedTaxBenefitsDetails" roleURI="http://www.koppers.com/role/IncometaxesSummaryofUnrecognizedTaxBenefitsDetails">
        <link:definition>9955563 - Disclosure - Income taxes - Summary of Unrecognized Tax Benefits (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InventoriesDetails" roleURI="http://www.koppers.com/role/InventoriesDetails">
        <link:definition>9955564 - Disclosure - Inventories (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PropertyPlantandEquipmentSummaryofPropertyPlantandEquipmentDetails" roleURI="http://www.koppers.com/role/PropertyPlantandEquipmentSummaryofPropertyPlantandEquipmentDetails">
        <link:definition>9955565 - Disclosure - Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PropertyPlantandEquipmentAdditionalInformationDetails" roleURI="http://www.koppers.com/role/PropertyPlantandEquipmentAdditionalInformationDetails">
        <link:definition>9955566 - Disclosure - Property, Plant and Equipment - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GoodwillandIntangibleAssetsAdditionalInformationDetails" roleURI="http://www.koppers.com/role/GoodwillandIntangibleAssetsAdditionalInformationDetails">
        <link:definition>9955567 - Disclosure - Goodwill and Intangible Assets - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GoodwillandIntangibleAssetsSummaryofChangesinCarryingAmountofGoodwillDetails" roleURI="http://www.koppers.com/role/GoodwillandIntangibleAssetsSummaryofChangesinCarryingAmountofGoodwillDetails">
        <link:definition>9955568 - Disclosure - Goodwill and Intangible Assets - Summary of Changes in Carrying Amount of Goodwill (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GoodwillandIntangibleAssetsSummaryofIdentifiableIntangibleAssetsDetails" roleURI="http://www.koppers.com/role/GoodwillandIntangibleAssetsSummaryofIdentifiableIntangibleAssetsDetails">
        <link:definition>9955569 - Disclosure - Goodwill and Intangible Assets - Summary of Identifiable Intangible Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="GoodwillandIntangibleAssetsSummaryofFutureAmortizationExpenseDetails" roleURI="http://www.koppers.com/role/GoodwillandIntangibleAssetsSummaryofFutureAmortizationExpenseDetails">
        <link:definition>9955570 - Disclosure - Goodwill and Intangible Assets - Summary of Future Amortization Expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlansAdditionalInformationDetails" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlansAdditionalInformationDetails">
        <link:definition>9955571 - Disclosure - Pensions and Post-Retirement Benefit Plans - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlansSummaryofComponentsofNetPeriodicBenefitCostforPensionPlansandOtherBenefitPlansDetails" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlansSummaryofComponentsofNetPeriodicBenefitCostforPensionPlansandOtherBenefitPlansDetails">
        <link:definition>9955572 - Disclosure - Pensions and Post-Retirement Benefit Plans - Summary of Components of Net Periodic Benefit Cost for Pension Plans and Other Benefit Plans (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlansSummaryofChangeinFundedStatusofPensionandPostRetirementPlansDetails" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlansSummaryofChangeinFundedStatusofPensionandPostRetirementPlansDetails">
        <link:definition>9955573 - Disclosure - Pensions and Post-Retirement Benefit Plans - Summary of Change in Funded Status of Pension and Post-Retirement Plans (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlansSummaryofPlanDataDetails" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlansSummaryofPlanDataDetails">
        <link:definition>9955574 - Disclosure - Pensions and Post-Retirement Benefit Plans - Summary of Plan Data (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlansSummaryofProjectedBenefitPaymentsDetails" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlansSummaryofProjectedBenefitPaymentsDetails">
        <link:definition>9955575 - Disclosure - Pensions and Post-Retirement Benefit Plans - Summary of Projected Benefit Payments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlansSummaryofWeightedAverageAssumptionsDetails" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlansSummaryofWeightedAverageAssumptionsDetails">
        <link:definition>9955576 - Disclosure - Pensions and Post-Retirement Benefit Plans - Summary of Weighted-Average Assumptions (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PensionsandPostRetirementBenefitPlansSummaryofWeightedAverageAssetAllocationforCompanysPensionPlansDetails" roleURI="http://www.koppers.com/role/PensionsandPostRetirementBenefitPlansSummaryofWeightedAverageAssetAllocationforCompanysPensionPlansDetails">
        <link:definition>9955577 - Disclosure - Pensions and Post-Retirement Benefit Plans - Summary of Weighted Average Asset Allocation for Company's Pension Plans (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DebtSummaryofLongTermDebtInstrumentsDetails" roleURI="http://www.koppers.com/role/DebtSummaryofLongTermDebtInstrumentsDetails">
        <link:definition>9955578 - Disclosure - Debt - Summary of Long-Term Debt Instruments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DebtAdditionalInformationDetails" roleURI="http://www.koppers.com/role/DebtAdditionalInformationDetails">
        <link:definition>9955579 - Disclosure - Debt - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DebtSummaryofDebtMaturitiesDetails" roleURI="http://www.koppers.com/role/DebtSummaryofDebtMaturitiesDetails">
        <link:definition>9955580 - Disclosure - Debt - Summary of Debt Maturities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesSummaryofOperatingLeaseCostsVariableLeaseCostsandSupplementalCashFlowInformationDetails" roleURI="http://www.koppers.com/role/LeasesSummaryofOperatingLeaseCostsVariableLeaseCostsandSupplementalCashFlowInformationDetails">
        <link:definition>9955581 - Disclosure - Leases - Summary of Operating Lease Costs, Variable Lease Costs and Supplemental Cash Flow Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesSummaryofAmountandTimingofCashFlowsFromOperatingLeasesDetails" roleURI="http://www.koppers.com/role/LeasesSummaryofAmountandTimingofCashFlowsFromOperatingLeasesDetails">
        <link:definition>9955582 - Disclosure - Leases - Summary of Amount and Timing of Cash Flows From Operating Leases (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesSummaryofAmountandTimingofCashFlowsFromOperatingLeasesDetails_1" roleURI="http://www.koppers.com/role/LeasesSummaryofAmountandTimingofCashFlowsFromOperatingLeasesDetails_1">
        <link:definition>9955582 - Disclosure - Leases - Summary of Amount and Timing of Cash Flows From Operating Leases (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LeasesSummaryofSupplementalConsolidatedBalanceSheetInformationRelatedtoLeasesDetails" roleURI="http://www.koppers.com/role/LeasesSummaryofSupplementalConsolidatedBalanceSheetInformationRelatedtoLeasesDetails">
        <link:definition>9955583 - Disclosure - Leases - Summary of Supplemental Consolidated Balance Sheet Information Related to Leases (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsandContingentLiabilitiesAdditionalInformationDetails" roleURI="http://www.koppers.com/role/CommitmentsandContingentLiabilitiesAdditionalInformationDetails">
        <link:definition>9955584 - Disclosure - Commitments and Contingent Liabilities - Additional Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsandContingentLiabilitiesSummaryofChangesinAccruedLiabilityforEnvironmentalMattersDetails" roleURI="http://www.koppers.com/role/CommitmentsandContingentLiabilitiesSummaryofChangesinAccruedLiabilityforEnvironmentalMattersDetails">
        <link:definition>9955585 - Disclosure - Commitments and Contingent Liabilities - Summary of Changes in Accrued Liability for Environmental Matters (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSDetails" roleURI="http://www.koppers.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSDetails">
        <link:definition>9955586 - Disclosure - SCHEDULE II &#8211; VALUATION AND QUALIFYING ACCOUNTS (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="kop_AuditInformationAbstract" abstract="true" name="AuditInformationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_EarningsPerShareBasicAndDilutedEPSAbstract" abstract="true" name="EarningsPerShareBasicAndDilutedEPSAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_WeightedAverageNumberOfSharesOutstandingBasicAndDilutedAbstract" abstract="true" name="WeightedAverageNumberOfSharesOutstandingBasicAndDilutedAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_DerivativeFairValueOfDerivativeCurrentAssets" abstract="false" name="DerivativeFairValueOfDerivativeCurrentAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DepreciationAndAmortization1" abstract="false" name="DepreciationAndAmortization1" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DepreciationInImpairmentAndRestructuring" abstract="false" name="DepreciationInImpairmentAndRestructuring" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_ChangeInDerivativeLiability" abstract="false" name="ChangeInDerivativeLiability" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DefinedBenefitPlanGainLossDueToSettlement" abstract="false" name="DefinedBenefitPlanGainLossDueToSettlement" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_PaymentsForComputerSoftwareImplementationNet" abstract="false" name="PaymentsForComputerSoftwareImplementationNet" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_NoncashOrPartNoncashAcquisitionNoncashConsideration" abstract="false" name="NoncashOrPartNoncashAcquisitionNoncashConsideration" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_OtherComprehensiveIncomeLossRevaluationAdjustmentFromAociPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax" abstract="false" name="OtherComprehensiveIncomeLossRevaluationAdjustmentFromAociPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_OtherComprehensiveIncomeLossRevaluationAdjustmentFromAociPensionAndOtherPostretirementBenefitPlansForNetGainLossTax" abstract="false" name="OtherComprehensiveIncomeLossRevaluationAdjustmentFromAociPensionAndOtherPostretirementBenefitPlansForNetGainLossTax" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_AcquisitionAndRestructuringTextBlock" abstract="false" name="AcquisitionAndRestructuringTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="kop_EarningsAndDividendsPerCommonShareTextBlock" abstract="false" name="EarningsAndDividendsPerCommonShareTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="kop_ScheduleOfCapitalizedComputerSoftwareTableTextBlock" abstract="false" name="ScheduleOfCapitalizedComputerSoftwareTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="kop_SummaryOfDetailsOfPlantClosuresAndRestructuringLiabilitiesTableTextBlock" abstract="false" name="SummaryOfDetailsOfPlantClosuresAndRestructuringLiabilitiesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="kop_ScheduleOfLeaseCostsAndSupplementalCashFlowInformationTableTextBlock" abstract="false" name="ScheduleOfLeaseCostsAndSupplementalCashFlowInformationTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="kop_LeasesSupplementalConsolidatedBalanceSheetInformationTableTableTextBlock" abstract="false" name="LeasesSupplementalConsolidatedBalanceSheetInformationTableTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="kop_SummaryOfSignificantAccountingPoliciesTable" abstract="true" name="SummaryOfSignificantAccountingPoliciesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="kop_SummaryOfSignificantAccountingPoliciesLineItems" abstract="true" name="SummaryOfSignificantAccountingPoliciesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_PeriodForPaymentTermsOnShipAndInvoiceArrangements" abstract="false" name="PeriodForPaymentTermsOnShipAndInvoiceArrangements" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="kop_PeriodForPaymentOfApprovalsBasisSale" abstract="false" name="PeriodForPaymentOfApprovalsBasisSale" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="kop_GreenhillReloadLLCMember" abstract="true" name="GreenhillReloadLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_BrownWoodPreservingCompanyIncMember" abstract="true" name="BrownWoodPreservingCompanyIncMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_KoppersChinaCarbonChemicalCompanyLimitedMember" abstract="true" name="KoppersChinaCarbonChemicalCompanyLimitedMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_TangshanIronSteelGroupCoLtdMember" abstract="true" name="TangshanIronSteelGroupCoLtdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_Pre-TaxChargesToEarnings" abstract="false" name="Pre-TaxChargesToEarnings" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_Non-CashCharges" abstract="false" name="Non-CashCharges" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_CashExpenditures" abstract="false" name="CashExpenditures" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_RetentionAndSeveranceCosts" abstract="false" name="RetentionAndSeveranceCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_AcceleratedDepreciationAndAssetWrite-DownCosts" abstract="false" name="AcceleratedDepreciationAndAssetWrite-DownCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_PlantCleaningWasteDisposalAndDemolitionCosts" abstract="false" name="PlantCleaningWasteDisposalAndDemolitionCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_OperatingLossFromAcquisition" abstract="false" name="OperatingLossFromAcquisition" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DepreciationAndAssetDisposalCostsMember" abstract="true" name="DepreciationAndAssetDisposalCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PlantCleaningWasteDisposalAndDemolitionCostsMember" abstract="true" name="PlantCleaningWasteDisposalAndDemolitionCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_WorkforceReductionProgramMember" abstract="true" name="WorkforceReductionProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_ConsultingServicesMember" abstract="true" name="ConsultingServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PhthalicAnhydrideShutdownMember" abstract="true" name="PhthalicAnhydrideShutdownMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_AOCICashFlowHedgeCumulativeGainLossBeforeTaxAtTimeOfDiscontinuation" abstract="false" name="AOCICashFlowHedgeCumulativeGainLossBeforeTaxAtTimeOfDiscontinuation" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_AOCICashFlowHedgeCumulativeGainLossAfterTaxAtTimeOfDiscontinuation" abstract="false" name="AOCICashFlowHedgeCumulativeGainLossAfterTaxAtTimeOfDiscontinuation" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DerivativeContractsMember" abstract="true" name="DerivativeContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_AccruedLiabilitiesCaptionMember" abstract="true" name="AccruedLiabilitiesCaptionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_HeatingOilContractsMember" abstract="true" name="HeatingOilContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_DerivativeNetCurrencyUnitsOutstanding" abstract="false" name="DerivativeNetCurrencyUnitsOutstanding" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_EmployeeMember" abstract="true" name="EmployeeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PerformanceSharesMarketConditionMember" abstract="true" name="PerformanceSharesMarketConditionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PerformanceStockUnitsIssuedInLieuOfCashIncentiveAwardMember" abstract="true" name="PerformanceStockUnitsIssuedInLieuOfCashIncentiveAwardMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_TwoThousandTwentyThreeThroughTwoThousandTwentyFiveMember" abstract="true" name="TwoThousandTwentyThreeThroughTwoThousandTwentyFiveMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_GrantsInMarchTwoThousandFifteenAndThereafterMember" abstract="true" name="GrantsInMarchTwoThousandFifteenAndThereafterMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfTargetAwardParticipantsEarn" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfTargetAwardParticipantsEarn" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsToBeVestedIfPerformanceCriteriaNotAchieved" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsToBeVestedIfPerformanceCriteriaNotAchieved" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOriginalTargetPercentage" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOriginalTargetPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="kop_JanuaryTwoThousandTwentyFiveGrantMember" abstract="true" name="JanuaryTwoThousandTwentyFiveGrantMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_JanuaryTwoThousandTwentyFourGrantMember" abstract="true" name="JanuaryTwoThousandTwentyFourGrantMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_JanuaryTwoThousandTwentyThreeGrantMember" abstract="true" name="JanuaryTwoThousandTwentyThreeGrantMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsLookBackPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsLookBackPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValueCapPerShare" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValueCapPerShare" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="kop_TwoThousandTwentyFourThroughTwoThousandTwentySixMember" abstract="true" name="TwoThousandTwentyFourThroughTwoThousandTwentySixMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_TwoThousandTwentyFiveThroughTwoThousandTwentySevenMember" abstract="true" name="TwoThousandTwentyFiveThroughTwoThousandTwentySevenMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_MarketConditionUnitsMember" abstract="true" name="MarketConditionUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByCreditedFromDividends" abstract="false" name="ShareBasedCompensationArrangementByCreditedFromDividends" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByPerformanceShareAdjustment" abstract="false" name="ShareBasedCompensationArrangementByPerformanceShareAdjustment" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsCreditedFromDividends" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsCreditedFromDividends" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="kop_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPerformanceShareAdjustment" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPerformanceShareAdjustment" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="kop_RailroadAndUtilityProductsAndServicesMember" abstract="true" name="RailroadAndUtilityProductsAndServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PerformanceChemicalsMember" abstract="true" name="PerformanceChemicalsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_CarbonMaterialsAndChemicalsMember" abstract="true" name="CarbonMaterialsAndChemicalsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_RailroadTreatedProductsMember" abstract="true" name="RailroadTreatedProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_UtilityPolesMember" abstract="true" name="UtilityPolesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_RailroadInfrastructureProductsAndServicesMember" abstract="true" name="RailroadInfrastructureProductsAndServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_WoodPreservativeAndOtherProductMember" abstract="true" name="WoodPreservativeAndOtherProductMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PitchAndRelatedProductsMember" abstract="true" name="PitchAndRelatedProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PhthalicAnhydrideNaphthaleneAndOtherChemicalsMember" abstract="true" name="PhthalicAnhydrideNaphthaleneAndOtherChemicalsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_CarbonBlackFeedstockAndDistillatesMember" abstract="true" name="CarbonBlackFeedstockAndDistillatesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_OtherIncomeExpenseToReconcileToAdjustedEarningsBeforeInterestTaxDepreciationAndAmortization" abstract="false" name="OtherIncomeExpenseToReconcileToAdjustedEarningsBeforeInterestTaxDepreciationAndAmortization" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_AdjustedEBITDAAbstract" abstract="true" name="AdjustedEBITDAAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_AdjustedEarningsBeforeInterestTaxDepreciationAndAmortization" abstract="false" name="AdjustedEarningsBeforeInterestTaxDepreciationAndAmortization" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_ItemsExcludedFromDeterminationOfSegmentProfitAbstract" abstract="true" name="ItemsExcludedFromDeterminationOfSegmentProfitAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_ImpairmentRestructuringAndPlantClosureBenefitsCosts" abstract="false" name="ImpairmentRestructuringAndPlantClosureBenefitsCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_ChangesInDerivativeLiability" abstract="false" name="ChangesInDerivativeLiability" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_AcquisitionInventoryStepUpAmortization" abstract="false" name="AcquisitionInventoryStepUpAmortization" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DefinedBenefitPlanGainLossDueToSettlementAndExpense" abstract="false" name="DefinedBenefitPlanGainLossDueToSettlementAndExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_InterestExpenseExcludedFromDeterminationOfSegmentProfit" abstract="false" name="InterestExpenseExcludedFromDeterminationOfSegmentProfit" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DepreciationAndAmortizationIncludingImpairmentAndRestructuring" abstract="false" name="DepreciationAndAmortizationIncludingImpairmentAndRestructuring" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_OtherCountriesMember" abstract="true" name="OtherCountriesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_IncomeTaxPaidFederalStateAndLocalAfterRefundReceivedAbstract" abstract="true" name="IncomeTaxPaidFederalStateAndLocalAfterRefundReceivedAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseSection162mAdjustmentAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseSection162mAdjustmentAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_EffectiveIncomeTaxRateReconciliationDeferredTaxLiabilityAdjustmentAmount" abstract="false" name="EffectiveIncomeTaxRateReconciliationDeferredTaxLiabilityAdjustmentAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseSection162mAdjustmentPercent" abstract="false" name="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseSection162mAdjustmentPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="kop_EffectiveIncomeTaxRateReconciliationDeferredTaxLiabilityAdjustmentPercent" abstract="false" name="EffectiveIncomeTaxRateReconciliationDeferredTaxLiabilityAdjustmentPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="kop_IncomeTaxesTable" abstract="true" name="IncomeTaxesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="kop_CopperSwapContractsMember" abstract="true" name="CopperSwapContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_IncomeTaxesLineItems" abstract="true" name="IncomeTaxesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_MinimumEffectiveCorporateTaxRateIncomeAsPerPillarTwo" abstract="false" name="MinimumEffectiveCorporateTaxRateIncomeAsPerPillarTwo" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="kop_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpenseBenefit" abstract="false" name="UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpenseBenefit" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DeferredTaxAssetsFederalAndStateTaxLossCarryforwardsSubjectToExpiration" abstract="false" name="DeferredTaxAssetsFederalAndStateTaxLossCarryforwardsSubjectToExpiration" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DeferredTaxAssetsForeignTaxLossCarryforwardsSubjectToExpiration" abstract="false" name="DeferredTaxAssetsForeignTaxLossCarryforwardsSubjectToExpiration" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DeferredTaxLiabilitiesDerivativesNet" abstract="false" name="DeferredTaxLiabilitiesDerivativesNet" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_OperatingLossCarryforwardsAndTaxCreditCarryforwardsMember" abstract="true" name="OperatingLossCarryforwardsAndTaxCreditCarryforwardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_OperatingLossesCarryforwardsAndCapitalLossesCarryforwardsMember" abstract="true" name="OperatingLossesCarryforwardsAndCapitalLossesCarryforwardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_RailroadProductsAndServicesMember" abstract="true" name="RailroadProductsAndServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_UtilityProductsMember" abstract="true" name="UtilityProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_GoodwillDivestituresDuringPeriod" abstract="false" name="GoodwillDivestituresDuringPeriod" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_SalariedAndHourlyEmployeesMember" abstract="true" name="SalariedAndHourlyEmployeesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_AnnuityInsurancePolicyMember" abstract="true" name="AnnuityInsurancePolicyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_UsQualifiedPensionPlanMember" abstract="true" name="UsQualifiedPensionPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_NumberOfNonQualifiedDefinedBenefitPensionPlans" abstract="false" name="NumberOfNonQualifiedDefinedBenefitPensionPlans" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="kop_IncreaseDecreaseInRevaluationOfBulkInsurancePolicy" abstract="false" name="IncreaseDecreaseInRevaluationOfBulkInsurancePolicy" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_NumberOfParticipantsToReceivePensionPayment" abstract="false" name="NumberOfParticipantsToReceivePensionPayment" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="kop_AdditionalCashFunding" abstract="false" name="AdditionalCashFunding" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DefinedBenefitPlanAssets" abstract="false" name="DefinedBenefitPlanAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_DefinedBenefitPlanBenefitObligationExpensesPaid" abstract="false" name="DefinedBenefitPlanBenefitObligationExpensesPaid" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_OtherSecuritiesMember" abstract="true" name="OtherSecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_SixPointSixThreePercentCreditFacilityMember" abstract="true" name="SixPointSixThreePercentCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_CreditFacilityMember" abstract="true" name="CreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_TermLoanBMember" abstract="true" name="TermLoanBMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_RevolvingCreditAgreementMember" abstract="true" name="RevolvingCreditAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_SwinglineRevolvingCreditFacilityMember" abstract="true" name="SwinglineRevolvingCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_AmendmentNumberOneToCreditFacilityMember" abstract="true" name="AmendmentNumberOneToCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_AmendmentNumberTwoToCreditFacilityMember" abstract="true" name="AmendmentNumberTwoToCreditFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_SeniorSecuredCreditFacilitiesMember" abstract="true" name="SeniorSecuredCreditFacilitiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_AmendedNetLeverageRatioFinancialCovenant" abstract="false" name="AmendedNetLeverageRatioFinancialCovenant" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="kop_AmendedBasisPointCreditSpreadAdjustment" abstract="false" name="AmendedBasisPointCreditSpreadAdjustment" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="kop_DebtInstrumentFloorInterestRate" abstract="false" name="DebtInstrumentFloorInterestRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="kop_DebtInstrumentPercentageOfPrincipalPayment" abstract="false" name="DebtInstrumentPercentageOfPrincipalPayment" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="kop_CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract" abstract="true" name="CashPaidForAmountsIncludedInMeasurementOfLeaseLiabilitiesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="kop_BeazerEastMember" abstract="true" name="BeazerEastMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PortlandHarborMember" abstract="true" name="PortlandHarborMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_PortlandHarborTrusteeClaimsMember" abstract="true" name="PortlandHarborTrusteeClaimsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_EnvironmentalRemedialSiteTwoMember" abstract="true" name="EnvironmentalRemedialSiteTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_UtilityAndIndustrialProductsMember" abstract="true" name="UtilityAndIndustrialProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="kop_NumberOfSitesListedOnNationalPrioritiesList" abstract="false" name="NumberOfSitesListedOnNationalPrioritiesList" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="kop_NumberOfPotentiallyResponsibleParties" abstract="false" name="NumberOfPotentiallyResponsibleParties" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="kop_NetPresentValueOfSelectedRemedyEstimation" abstract="false" name="NetPresentValueOfSelectedRemedyEstimation" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_UndiscountedCostOfSelectedRemedyEstimation" abstract="false" name="UndiscountedCostOfSelectedRemedyEstimation" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_LossContingencyClaimsNumber" abstract="false" name="LossContingencyClaimsNumber" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="kop_NumberOfDefendantsFilingAnAppeal" abstract="false" name="NumberOfDefendantsFilingAnAppeal" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="kop_CostsOfParticipatingInPotentiallyResponsiblePartiesGroup" abstract="false" name="CostsOfParticipatingInPotentiallyResponsiblePartiesGroup" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_NumberOfAcquiredPlantSitesWithRecordedEnvironmentalRemediationLiability" abstract="false" name="NumberOfAcquiredPlantSitesWithRecordedEnvironmentalRemediationLiability" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="kop_ValuationAllowancesAndReservesIncreaseDecreaseChargedToCostAndExpense" abstract="false" name="ValuationAllowancesAndReservesIncreaseDecreaseChargedToCostAndExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="kop_ValuationAllowancesAndReservesCurrencyTranslation" abstract="false" name="ValuationAllowancesAndReservesCurrencyTranslation" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
