Document:

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                                                                  Exhibit 10.15

                                                                  Execution Copy

                              TAX MATTERS AGREEMENT

                                 BY AND BETWEEN

                                  GENCORP INC.

                                       AND

                              OMNOVA SOLUTIONS INC.

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                             TAX MATTERS AGREEMENT
                                 BY AND BETWEEN
                                  GENCORP INC.
                                      AND
                             OMNOVA SOLUTIONS INC.

                               TABLE OF CONTENTS

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                                                                                                               PAGE
<S>                                                                                                            <C>
RECITALS              .........................................................................................1
ARTICLE I             DEFINITIONS..............................................................................2
ARTICLE II            ALLOCATION OF TAX LIABILITIES............................................................6
         2.01         Liability for United States Federal Taxes................................................6
         2.02         Liability for State Taxes................................................................6
         2.03         Liability for Foreign Taxes..............................................................7
         2.04         Spin-off Taxes...........................................................................7
         2.05         Method of Allocating Taxes for Straddle Periods..........................................7
         2.06         Tax Accounting Practices.................................................................8
ARTICLE III           PREPARATION AND FILING OF TAX RETURNS....................................................8
         3.01         General..................................................................................8
         3.02         Consolidated, Combined and Joint Returns.................................................8
         3.05         Right to Review Returns..................................................................9
ARTICLE IV            TAX REFUNDS AND CARRYOVERS..............................................................10
         4.01         Refunds.................................................................................10
         4.02         Carrybacks or Claims for Refund.........................................................10
         4.03         Carryovers from Pre-Distribution Periods to Post-Distribution Periods...................11
         4.04         State Tax Credits.......................................................................11
ARTICLE V             TAX PAYMENTS............................................................................11
         5.01         Payment of Consolidated United States Federal Taxes
                      for Pre-Distribution Periods............................................................11
         5.02         Payment of State and Foreign Taxes for Which
                      GenCorp has Filing Responsibility.......................................................11
         5.03         Indemnification Payments................................................................11
         5.04         Tax Treatment of Tax and Indemnification Payments.......................................12
ARTICLE VI            TAX AUDITS AND APPEALS....................................................................
         6.01         Notice..................................................................................12
         6.02         Control of Audits and Appeals...........................................................12
         6.03         Consent to Settlements..................................................................13
         6.04         Information.............................................................................14
         6.05         Expenses................................................................................14
         6.06         Adverse Effect Issues...................................................................14
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<S>                                                                                                           <C>
ARTICLE VII           SPECIAL RULES PERTAINING TO GENCORP SERVICES, INC.......................................16
         7.01         Liability for State Taxes...............................................................16
         7.02         GSI Tax Returns.........................................................................16
ARTICLE VIII          MISCELLANEOUS MATTERS.....................................................................
         8.01         Amendment and Waiver....................................................................16
         8.02         Tax Allocation Agreements, Etc..........................................................16
         8.03         Entire Agreement; Inconsistent Provisions...............................................17
         8.04         Affiliate Obligations...................................................................17
         8.05         Further Action..........................................................................17
         8.06         Time for Notice.........................................................................17
         8.07         Notices.................................................................................17
         8.08         Remedies................................................................................17
         8.09         Successors and Assigns..................................................................18
         8.10         Severability............................................................................18
         8.11         Counterparts............................................................................18
         8.12         Descriptive Headings....................................................................18
         8.13         No Third-Party Beneficiaries............................................................18
         8.14         Construction............................................................................18
         8.15         Form of Payments and Late Payments......................................................19
         8.16         Governing Law...........................................................................19
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                                                                  Execution Copy

                              TAX MATTERS AGREEMENT
                                 BY AND BETWEEN
                                  GENCORP INC.
                                       AND
                              OMNOVA SOLUTIONS INC.

         THIS TAX MATTERS AGREEMENT (the "Agreement") is made and entered into
September 30, 1999, by and between GenCorp Inc. ("GenCorp"), an Ohio
corporation, and OMNOVA Solutions Inc. ("OMNOVA"), an Ohio corporation, on
behalf of themselves and their respective Affiliates.

                                    RECITALS:
                                    ---------

         WHEREAS, the Board of Directors of GenCorp has determined that it is
appropriate and desirable to separate GenCorp's Decorative & Building Products
and Performance Chemicals businesses from its other businesses by means of a
series of transactions, including (1) a transfer to OMNOVA of the assets of such
businesses in exchange for all the issued and outstanding stock of OMNOVA and
other consideration (the "Separation") and (2) a dividend consisting of all the
issued and outstanding stock of OMNOVA, on a pro rata basis, to the holders of
GenCorp common stock (the "Distribution"), in transactions that will qualify for
tax-free treatment for purposes of United States Federal Taxes under Sections
368(a)(1)(D) and 355 of the Code (the Separation, the Distribution and related
transactions described in the Ruling Request and in the Ruling being,
collectively, the "Spin-off"); and

         WHEREAS, GenCorp and OMNOVA have set forth the principal corporate
transactions required to effect the Spin-off, together with the terms of such
transactions and related matters, in a Distribution Agreement between GenCorp
and OMNOVA, dated September 30, 1999 (the Distribution Agreement"); and

         WHEREAS, after the Spin-off. OMNOVA and its Affiliates will cease to be
members of the affiliated group (within the meaning of Section 1504(a) of the
Code) of which GenCorp is the common parent, effective as of the Distribution
Date; and

         WHEREAS, GenCorp and OMNOVA desire to provide for and agree upon (1)
the allocation of liabilities for Taxes with respect to the Parties prior to,
arising out of, and subsequent to the Spin-off, (2) the preparation and filing
of Tax Returns along with the payment of Taxes shown due and payable thereon,
(3) the retention and maintenance of records necessary to prepare and file
appropriate Tax Returns and to handle any Tax Contests, as well as the provision
for appropriate access to those records by the Parties, (4) the conduct of
audits, examinations and proceedings by governmental entities which could result
in a redetermination of Taxes of the Parties, (5) the responsibility for any Tax
deficiencies and the treatment of refunds of Taxes and Carryovers and Carrybacks
of the Parties, (6) the cooperation of the Parties

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with one another in order to fulfill their duties and responsibilities under
this Agreement and under the Code and other applicable Law, and (7) other
matters related to Taxes;

         NOW, THEREFORE, in consideration of the foregoing, and of the mutual
promises, covenants and conditions hereinafter contained, the Parties agree as
follows:

                                    ARTICLE I
                                    ---------
                                   DEFINITIONS
                                   -----------

         "Affiliate" means any Person that directly or indirectly controls, is
under the control of, or is under common control with, the Person in question.
"Control" of a Person means the possession, directly or indirectly, of the power
to direct or cause the direction of the management and policies of such Person,
whether through ownership or voting securities, by contract or otherwise. Except
as otherwise provided herein, the term "Affiliate" shall refer to Affiliates of
a Person determined immediately after the Distribution Date, provided, however,
that, after the Spin-off, GenCorp and OMNOVA (in each case together with the
members of their respective Groups) shall not be Affiliates of each another.

         "Adverse Effect Issue" has the meaning set forth in Section 6.06(b).

         "Affected Party" has the meaning set forth in Section 6.06(b).

         "Agreement" has the meaning set forth in the introduction.

         "Carryover" and "Carryback" mean any net operating loss, net capital
loss, excess tax credit, or other similar Tax item which may or must be carried
forward or back, respectively, from one Tax Period to another under the Code or
other applicable Law.

         "Code" means the United States Internal Revenue Code of 1986, as
amended, or any successor law.

         "Distribution" has the meaning set forth in the Recitals.

         "Distribution Agreement" has the meaning set forth in the Recitals.

         "Distribution Date" means the effective date of the Distribution as set
forth in the Distribution Agreement.

         "Examined Party" has the meaning set forth in Section 6.06(a).

         "Foreign Taxes" means any Taxes imposed or collected by any foreign
government, together with any interest and any penalties, additions to tax or
additional amounts with respect thereto, and "Foreign Tax" means any one of the
foregoing Foreign Taxes.

         "GenCorp" has the meaning set forth in the introduction.

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         "GenCorp Group" means GenCorp and its Affiliates.

         "Granting Party" has the meaning set forth in Section 6.06(b).

         "Group" means each of the GenCorp Group and the OMNOVA Group whenever
no distinction is otherwise required between them.

         "GSI" has the meaning set forth in Section 7.01.

         "Including" has the meaning set forth in Section 8.14.

         "Indemnification Payment" means a payment subject to Section 5.03.

         "Indemnified Party" and "Indemnifying Party" have the meanings set
forth in Section 5.03(b).

         "IRS" means the United States Internal Revenue Service and any
successor department, agency or organization of the United States.

         "Joint Contest" means any Tax Contest seeking a redetermination of
Taxes which involves or could involve one or more members of the GenCorp Group
and the OMNOVA Group.

         "Law" means the law of any governmental entity or political subdivision
thereof, other than the Code, relating to any Tax.

         "OMNOVA" has the meaning set forth in the introduction.

         "OMNOVA Group" means OMNOVA and its Affiliates.

         "OMNOVA Group Carryback" has the meaning set forth in Section 4.02(a).

         "Participating Party" has the meaning set forth in Section 6.02(b).

         "Parties" means GenCorp and OMNOVA.

         "Party" means either GenCorp or OMNOVA.

         "Person" means any individual and any partnership, joint venture,
corporation, limited liability company, trust, unincorporated organization or
other business entity formed or operating under United States or foreign law.

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         "Post-Distribution Period" means any Tax Period beginning after the
Distribution Date and, in the case of any Straddle Period, the portion of such
Tax Period ending after the Distribution Date.

         "Pre-Distribution Period" means any Tax Period ending on or before the
Distribution Date and, in the case of any Straddle Period, the portion of such
Tax Period ending on the Distribution Date.

         "Prime Rate" means the prime interest rate published in the Wall Street
Journal from time to time.

         "Return" means any return or report of Taxes due, any information
return or statement with respect to Taxes, or any other similar report,
statement, declaration, or document required to be filed under the Code or other
Laws, any claims for refund of Taxes paid, and any amendments or supplements to
any of the foregoing.

         "Ruling" means the private letter ruling, dated June 30, 1999, issued
by the IRS in reply to the Ruling Request (including any amendment or supplement
thereto).

         "Ruling Request" means the private letter ruling request filed by
GenCorp with the IRS on February 24, 1999, (as modified or supplemented by any
materials submitted to the IRS), seeking rulings that, inter alia, the Spin-off
will qualify for Federal income tax purposes for tax-free treatment under
Sections 368(a)(1)(D) and 355 of the Code.

         "Separate Contest" means a Tax Contest which involves (i) only GenCorp
and members of the GenCorp Group, or (ii) only OMNOVA and members of the OMNOVA
Group.

         "Separation" has the meaning set forth in the Recitals.

         "Short Period" means any Tax Period which is based on an accounting
period which is shorter than the normal accounting period used for determining
such Tax (e.g., in the case of the United States Federal income Tax, any Tax
Period of less than one year).

         "Spin-off" has the meaning set forth in the Recitals.

         "Spin-off Taxes" means any Taxes incurred by or imposed on GenCorp or
OMNOVA (or their respective Affiliates) resulting from the Spin-off and any
disposition of stock or assets undertaken to separate the OMNOVA Group from the
GenCorp Group, in accordance with the terms of the Distribution Agreement.

         "State Property Taxes" means State Taxes that are imposed on or with
respect to the ownership or use of property or based on the value of property,
including ad valorem, real property, personal property (tangible or intangible)
and similar Taxes.

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         "State Taxes" means all Taxes imposed or collected by any state or
local government in the United States (including possessions and territories of
the United States), and "State Tax" means any one of the foregoing State Taxes.

         "Straddle Period" means (i) any Tax Period that begins before and ends
after the Distribution Date, (ii) any Short Period that ends on the Distribution
Date and (iii) any Short Period that begins on the first day following the
Distribution Date.

         "Tax Authority" means, with respect to any Tax, the governmental entity
or political subdivision thereof that imposes such Tax and any governmental
department, office or agency (if any) charged with the determination or
collection of such Tax for such entity or subdivision.

         "Tax Benefit" means any refund, credit, Carryover, Carryback or other
reduction in otherwise required Tax payments. Such term does not include a
decrease in any Tax in one Tax Period that results from a Tax Adjustment in
another Tax Period, such as an increase in a deduction for depreciation that
results from a determination that, in a previous Tax Period, an expenditure is
capitalized and not deducted, or an item of gain is recognized.

         "Tax Contest" means an audit, review, examination or any other
administrative or judicial proceeding with the purpose or effect of
redetermining Taxes of any member of any of the GenCorp Group or the OMNOVA
Group for (1) any Pre-Distribution Period, (2) any Straddle Period or (3) any
Post-Distribution Period, if such proceeding could result in any Tax Adjustment
or Tax Benefit for any Pre-Distribution Period or Straddle Period (without
regard to whether such matter was initiated by an appropriate Tax Authority or
in response to a claim for a refund of Taxes).

         "Taxes" means all Federal, state, territorial, local, foreign and other
net income, gross income, gross receipts, sales, use, value added, ad valorem,
transfer, franchise, profits, license, lease, service, service use, withholding,
payroll, employment, unemployment insurance, workers compensation, social
security, excise, severance, stamp, business license, occupation, premium,
property, environmental, windfall profits, customs, duties, alternative minimum,
estimated or other taxes, fees, premiums, assessments or charges of any kind
whatever imposed or collected by any governmental entity or political
subdivision thereof, which any member of the GenCorp Group or of the OMNOVA
Group is required to pay, collect or withhold, together with any interest and
any penalties, additions to Tax or additional amounts with respect thereto, and
"Tax" means any one of the foregoing Taxes.

         "Tax Period" means, with respect to any Tax, the period for which the
Tax is reported as provided under the Code or other applicable Laws.

         "United States Federal Taxes" means all Taxes imposed or collected by
the United States Federal Government, and "United States Federal Tax" means any
one of the foregoing United States Federal Taxes.

         "1999 Fiscal Year" has the meaning set forth in Section 3.02(b).

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                                   ARTICLE II
                                   ----------
                          ALLOCATION OF TAX LIABILITIES
                          -----------------------------

         2.01 LIABILITY FOR UNITED STATES FEDERAL TAXES.

                  (a) Subject to Sections 2.04, 2.05, 4.01, and 4.02, GenCorp
shall be liable for, and shall indemnify and hold the OMNOVA Group harmless
from:

                      (1)     any United States Federal Taxes imposed on
GenCorp, OMNOVA and all members of their respective Groups for any
Pre-Distribution Period and

                      (2)     any United States Federal Taxes imposed on
any members of the GenCorp Group for any Post-Distribution Period.

                  (b) Subject to Sections 2.04, 2.05, 4.01, and 4.02, OMNOVA
shall be liable for, and shall indemnify and hold the GenCorp Group harmless
from all United States Federal Taxes imposed on any members of the OMNOVA Group
for any Post-Distribution Period.

         2.02 LIABILITY FOR STATE TAXES.

                  (a)     Subject to Sections 2.04, 2.05, 4.01, 4.02, and 7.01,
GenCorp shall be liable for, and shall indemnify and hold the OMNOVA Group
harmless from:

                      (1) any State Taxes imposed on GenCorp or OMNOVA and all
members of their respective Groups for any Pre-Distribution Period (except as
provided in Section 2.02(b)(1)) and

                      (2) any State Taxes imposed on any members of the GenCorp
Group for any Post-Distribution Period.

                  (b)     Subject to Sections 2.04, 2.05, 4.01, and 4.02,
OMNOVA shall be liable for, and shall indemnify and hold the GenCorp Group
harmless from:

                      (1) any State Property Taxes imposed on GenCorp or OMNOVA
and all members of their respective groups for any Pre-Distribution Period, to
the extent such State Property Taxes are imposed on or with respect to the
ownership or use, or are based on the value, of property principally used by any
member of the OMNOVA Group before the Spin-off or immediately thereafter
(including all property transferred, directly or indirectly, to any member of
the OMNOVA Group in the Spin-off).

                      (2) any State Taxes imposed on any members of the OMNOVA
Group for any Post-Distribution Period.

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         2.03 LIABILITY FOR FOREIGN TAXES.

                  (a) Subject to Sections 2.04, 2.05, 4.01, and 4.02,
GenCorp shall be liable for, and shall indemnify and hold the OMNOVA Group
harmless from:

                      (1) any Foreign Taxes imposed on GenCorp, OMNOVA or their
respective Groups for any Pre-Distribution Period and

                      (2) any Foreign Taxes imposed on the GenCorp Group for any
Post-Distribution Period.

                  (b) Subject to Sections 2.04, 2.05, 4.01, and 4.02, OMNOVA
shall be liable for, and shall indemnify and hold the GenCorp Group harmless
from all Foreign Taxes imposed on the OMNOVA Group for any Post-Distribution
Period.

         2.04 SPIN-OFF TAXES. Except as otherwise provided in Section 5.02 of
the Distribution Agreement, GenCorp shall be liable for, and shall indemnify and
hold the OMNOVA Group harmless from all Spin-off Taxes.

         2.05 METHOD OF ALLOCATING TAXES FOR STRADDLE PERIODS.

                  (a) To the extent required or allowed by applicable law,
the Parties shall apportion their respective liabilities for Taxes relating to a
Straddle Period that begins before and ends after the Distribution Date in
accordance with an actual or hypothetical closing of the books on the
Distribution Date in the case of income Taxes or other Taxes based on actual
events and activities of such Party.

                  (b) Except as provided in Section 2.05(a) Taxes for any
Straddle Period, with respect to any member of the GenCorp Group and the OMNOVA
Group shall be apportioned between Pre-Distribution and Post-Distribution
Periods as follows: First, Taxes for Tax Periods or portions thereof ending on
the last day of the calendar month preceding the Distribution Date (such date is
hereinafter referred to as the "Cutoff Date") shall be based on actual events
and activities through the Cutoff Date and in accordance with past accounting
practices. Second, Taxes for the period from the Cutoff Date through the
Distribution Date shall be computed by prorating the activities of the calendar
month which includes the Distribution Date on a daily pro rata basis.
Notwithstanding the foregoing provisions of this Section 2.05(b), (i)
depreciation, amortization and depletion for any Straddle Period shall be
apportioned on a daily pro rata basis and (ii) extraordinary items not arising
in the ordinary course of business shall be apportioned to the Tax Period in
which the event giving rise to such item occurs.

                  (c) For purposes of this Agreement, franchise Taxes shall
be allocated to the Periods in which the items with respect to which the Tax is
imposed occur, regardless of whether the Tax is imposed with respect to one or
more other Periods.

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                  (d) For purposes of this Agreement, any taxes computed on
a unitary method shall be allocated between the members of the GenCorp Group and
the OMNOVA Group consistent with past accounting practice and consistent with
applicable law.

         2.06 TAX ACCOUNTING PRACTICES. Any Straddle Period Returns prepared by
any member of the GenCorp Group or the OMNOVA Group shall be filed in accordance
with past Tax accounting practices used with respect to the Tax Returns in
question, and to the extent any items are not covered by past practices, in
accordance with reasonable Tax accounting practices selected by GenCorp or
OMNOVA, as the case may be (except that accounting elections and determinations
shall be made by each Party, where reasonably possible, in a manner that
minimizes the net Tax incurred by the other Party and its Affiliates). In the
event any member of the GenCorp Group or the OMNOVA Group files Tax Returns for
Straddle Periods that are inconsistent with such past Tax accounting practices,
then, notwithstanding any provision of this Agreement to the contrary, in
addition to any other remedies available, the other Party shall only be
responsible for the amount of Taxes it would owe if such Tax Returns had been
consistent with such past Tax accounting practices. The Parties shall consult
regarding any such proposed changes in accounting methods and attempt in good
faith to agree as to procedures to be followed and the amount of any indemnity
hereunder.

                                   ARTICLE III
                                   -----------
                      PREPARATION AND FILING OF TAX RETURNS
                      -------------------------------------

         3.01 GENERAL. Except as otherwise provided in this Article III, Tax
Returns shall be prepared and filed by the Person liable for the Tax reported on
such Tax Return, or otherwise obligated to file such Return, under the Code or
other applicable Law. Schedule 3.01 sets forth the United States Federal and
State Tax Returns relating to income Taxes to be filed under this provision and
the Person responsible for filing each such Return. Without limiting the
foregoing, in accordance with Article VI, the Person responsible for filing such
a Return shall also be responsible for responding to any revenue agent request
or any other formal or informal request for information or otherwise relating to
such Return by the IRS or any other applicable Tax Authority. The Parties shall
render assistance and cooperate with one another in accordance with the terms of
the Distribution Agreement.

         3.02     CONSOLIDATED, COMBINED AND JOINT RETURNS.

                  (a) Any Tax Returns for United States Federal Taxes
imposed for any Pre-Distribution Period which reflect Taxes for which any member
of the GenCorp Group has liability under Article II (including, without
limitation, GenCorp's consolidated Federal income Tax Return for the Tax Period
in which the Distribution occurs) shall be prepared by and filed by GenCorp. In
furtherance of, and not by limitation of, the cooperation and assistance
required by the terms of the Distribution Agreement, OMNOVA shall, in connection
with any Tax Return for United States Federal income Taxes for any
Pre-Distribution Period filed after the Distribution Date for which GenCorp has
filing responsibility under this Agreement and which reflects income or
transactions attributable to the OMNOVA Group, provide GenCorp with (i) true and
correct separate Federal income Tax Returns for the OMNOVA Group, together with
all

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accompanying work papers and other computations of separate Federal income Tax
liability for the OMNOVA Group; (ii) a true and correct reconciliation of book
income to Federal taxable income for the OMNOVA Group, and (iii) any other
information or documentation reasonably requested by GenCorp in connection with
such Tax Return; provided, however, that the Parties shall consult regarding the
type and extent of the information required by GenCorp hereunder.

                  (b) With respect to the Period ending on November 30, 1999,
or, where applicable to any Group member, the corresponding 52-53 week Period
(the "1999 Fiscal Year"), OMNOVA hereby agrees to provide GenCorp with all such
Returns, work papers and computations relating to Federal Taxes on or before May
15, 2000, and with all such Returns, work papers and computations relating to
State Taxes on or before on or before June 15, 2000.

                  (c) If, without reasonable cause, OMNOVA fails to provide any
information required by this Section 3.02 within the time frame specified
herein, GenCorp may file the applicable Returns based on the information
available at the time such Returns are due and OMNOVA shall be liable for, and
shall indemnify GenCorp from, any interest or penalties relating to Taxes,
additions to Tax or other costs imposed on GenCorp as a result of OMNOVA's
failure to provide such information; provided, however, that in no event will
OMNOVA be liable to reimburse GenCorp for or indemnify GenCorp against any
increase in tax liability (excluding interest, penalties, additions to tax and
the like) resulting from such information. The Parties shall attempt in good
faith to reach agreement regarding the information to be provided by OMNOVA to
GenCorp and the time such information is needed.

                  (d) Any Tax Returns for State Taxes for any Pre-Distribution
Period which reflect Taxes for which the GenCorp Group has liability
under Article II, shall be prepared and filed by GenCorp. Sections 3.02(a) and
3.02(c) shall apply mutatis mutandis to all State Tax Returns for any
Pre-Distribution Period that GenCorp must prepare and/or file under this
Agreement that is measured by income and that includes any income or
transactions attributable to OMNOVA or any member of the OMNOVA Group.

                  (e) Any Tax Returns for Foreign Taxes for any Pre-Distribution
Period which reflect Taxes for which the GenCorp Group has liability under
Article II, shall be prepared and filed by GenCorp. Any Tax Returns for Foreign
Taxes for any Post-Distribution Period (including any such Straddle Period)
which reflect Taxes for which the OMNOVA Group has liability under Article II,
shall be prepared and filed by OMNOVA. For any Straddle Period Tax Returns
prepared and filed by OMNOVA, the liability for Taxes reflected on such Tax
Return will be divided between the Pre-Distribution Period and the
Post-Distribution Period in accordance with Section 2.05.

         3.03 RIGHT TO REVIEW RETURNS. Upon the request of either Party, the
other Party shall make available for inspection and copying all Tax Returns (and
related work papers) with respect to Taxes to the extent that (i) such Return
relates to Taxes for which the requesting Party may be liable under this
Agreement, (ii) such Return relates to Taxes for which the requesting Party may
have a claim for Tax Benefits hereunder, or (iii) the requesting Party
reasonably determines that it must inspect such Return to confirm any Person's
compliance with the terms of this

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Agreement. The Parties shall attempt in good faith to resolve any issues arising
out of the review of such Returns.

                                   ARTICLE IV
                                   ----------
                           TAX REFUNDS AND CARRYOVERS
                           --------------------------

         4.01 REFUNDS. Except as provided in Section 4.02, any refund of any
Taxes for any Pre-Distribution Period shall belong to GenCorp. In the event
OMNOVA or any of its Affiliates receives a refund for any Pre-Distribution
Period, the Person receiving such refund shall immediately remit such refund to
GenCorp. A refund includes the application of an amount otherwise refundable as
a reduction of amounts owed or to be owed notwithstanding that no cash is
transferred.

         4.02 CARRYBACKS OR CLAIMS FOR REFUND.

                  (a) At the request of OMNOVA and at OMNOVA's expense,
GenCorp or one of its Affiliates will file one or more claims for refund
(including any tentative carryback or refund adjustment under Section 6411 of
the Code) of Taxes with respect to any Pre-Distribution Period resulting from
any Carryback generated by any member of the OMNOVA Group from a
Post-Distribution Period ("OMNOVA Group Carryback"), provided (subject to
Section 4.02(b)) that such refund does not result in any increase in the
liability of any member of GenCorp's Group for Taxes for any Tax Period. In the
event GenCorp or one of its Affiliates receives a refund for any
Pre-Distribution Period resulting from any OMNOVA Group Carryback from a
Post-Distribution Period, GenCorp shall immediately remit such refund to OMNOVA.

                  (b) In the event GenCorp or one of its Affiliates files
one or more claims for refund (including any tentative carryback or refund
adjustment under Section 6411 of the Code) of Taxes with respect to any
Pre-Distribution Period resulting from any OMNOVA Group Carryback from a
Post-Distribution Period that results in any increase in the liability of any
member of GenCorp's Group for Taxes for any Tax Period, GenCorp or any of its
Affiliates shall be entitled to retain that portion of the refund that exactly
offsets the additional Taxes for which it becomes liable as a result of filing
the refund claim, and the balance of such refund shall be refunded immediately
to OMNOVA. To the extent the increased liability for Taxes of GenCorp or any of
its Affiliates with respect to any Pre-Distribution Period resulting from any
OMNOVA Group Carryback from a Post-Distribution Period is reversed for any Tax
Period, the amount of any Tax Benefit resulting from such reversal shall be paid
immediately to OMNOVA on the date when the Return is filed for the year in which
the Tax Benefit arises or, if such return has already been filed, then
immediately after GenCorp or any of its Affiliates receives a payment reflecting
the Tax Benefit in question. Similarly, to the extent the increased liability
for Taxes of GenCorp or any of its Affiliates with respect to any
Pre-Distribution Period resulting from any OMNOVA Group Carryback from a
Post-Distribution Period for any Period arises after the refund has been paid to
OMNOVA, GenCorp shall inform OMNOVA of the amount of such increase, and OMNOVA
shall pay the amount of such increase to GenCorp promptly. Procedures similar to
those in Section 5.03 shall apply. All computations under this Section 4.02

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shall be adjusted to take into account interest payable by or to GenCorp, and
any Tax Benefit resulting therefrom.

         4.03 CARRYOVERS FROM PRE-DISTRIBUTION PERIODS TO POST-DISTRIBUTION
PERIODS.

                  (a) If GenCorp or any of its Affiliates (determined for
this purpose as of immediately before the Distribution Date) is entitled to
carry over any Tax Benefit from a Pre-Distribution Period to a Post-Distribution
Period, and if the proper person to claim such Tax Benefit is a member of the
OMNOVA Group, OMNOVA or such member shall, upon request of GenCorp and at
GenCorp's expense, file any return or report reasonably requested by GenCorp in
a manner that claims such Tax Benefit and shall pay the full amount of such Tax
Benefit to GenCorp promptly upon receipt, provided (subject to Section 4.02(b)
)) that such Tax Benefit does not result in any increase in the liability of any
member of the OMNOVA Group for Taxes for any Tax Period.

                  (b) If OMNOVA or any of its Affiliates claims a carryover
of a Tax Benefit described in Section 4.03(a) that results in any increase in
the liability of any member of the OMNOVA Group for Taxes for any Tax Period,
the provisions of Section 4.02(b) shall apply, mutatis mutandis, to OMNOVA's
obligation to refund such Tax Benefit to GenCorp.

         4.04 STATE TAX CREDITS. Notwithstanding any other provision of this
Agreement, the Parties shall consult and shall attempt in good faith to agree
concerning the allocation between them of credits for State Taxes.

                                    ARTICLE V
                                    ---------
                                  TAX PAYMENTS
                                  ------------

         5.01 PAYMENT OF CONSOLIDATED UNITED STATES FEDERAL TAXES FOR
PRE-DISTRIBUTION PERIODS. GenCorp shall pay all Taxes due, be entitled to the
benefit of all overpayments of estimated income tax, and, except as provided in
Section 4.02, shall receive all refunds in connection with, the filing of
GenCorp's Tax Returns relating to U.S. Federal Taxes for all Pre-Distribution
Periods, including GenCorp's consolidated Federal income Tax Return for the 1999
Fiscal Year.

         5.02 PAYMENT OF STATE AND FOREIGN TAXES FOR WHICH GENCORP HAS FILING
RESPONSIBILITY. GenCorp shall pay to the appropriate Tax Authority all State and
Foreign Taxes for Tax Returns with respect to which GenCorp (or another member
of the GenCorp Group) has filing responsibility pursuant to Article III.

         5.03     INDEMNIFICATION PAYMENTS.

                  (a) The Parties shall attempt to agree upon procedures
for the payment of indemnities under this Agreement. In the absence of any such
Agreement, the procedures set forth in paragraph (b) shall be followed.

                                       11
<PAGE>   15

                  (b) Upon payment of any Taxes with respect to which
either Party is entitled to receive indemnification hereunder, such member (the
"Indemnified Party") shall send to the other Party (the "Indemnifying Party") an
invoice accompanied by evidence of payment and a statement detailing the Taxes
paid and describing in reasonable detail the particulars relating thereto. The
Indemnifying Party (or such one or more members of the Indemnifying Party's
Group as it shall nominate) shall remit payment for Taxes for which the
Indemnifying Party is liable for indemnification hereunder to the Indemnified
Party (or such one or more members of the Indemnified Party's Group as it shall
nominate) within 30 days of receipt of such invoice, evidence of payment and
statement, or at any earlier time identified by the Indemnifying Party.
Notwithstanding any provision in this Agreement to the contrary, to the extent
the Indemnified Party receives a refund of Taxes for which it has been
indemnified, it shall remit the refund to the Indemnifying Party (or such one or
more members of the Indemnifying Party's Group as it shall nominate)
immediately. The amount of any payment under this Section 5.03 that is
attributable to interest paid to a Tax Authority shall be adjusted to take into
account the Tax Benefit resulting therefrom.

         5.04 TAX TREATMENT OF TAX AND INDEMNIFICATION PAYMENTS. The Parties
agree that, in the absence of any change in law, any Tax or indemnification
payments made under this Agreement or the Distribution Agreement (including
payments made under Sections 2.04, 4.01, 4.02, 4,03, and 5.03 shall be reported
for Tax purposes by the payor and the recipient as capital contributions or
dividends, as appropriate, relating back to the period beginning before the
Distribution Date. The Parties will file their respective Tax Returns on this
basis, unless agreed otherwise in writing by the Indemnified Party and the
Indemnifying Party.

                                   ARTICLE VI
                                   ----------
                             TAX AUDITS AND APPEALS
                             ----------------------

         6.01 NOTICE.. Each Party shall provide prompt notice to the other Party
of any pending or threatened Tax Contest of which it becomes aware relating to
Taxes for Tax Periods for which it is indemnified by the other Party. Such
notice shall contain factual information (to the extent known) describing any
asserted Tax liability in reasonable detail and shall be accompanied by copies
of any notice or other document received from any Tax Authority in respect of
any such matter. If either Party has knowledge of an asserted Tax liability with
respect to a matter for which it is to be indemnified hereunder and such Party
fails to give the Indemnifying Party notice of such asserted Tax liability
within 30 days after it has received written notice thereof, then, unless such
failure has no material adverse effect upon the Indemnifying Party's ability to
participate in the Tax Contest, the Indemnifying Party shall have no obligation
to indemnify the Indemnified Party for any Taxes arising out of such asserted
Tax liability.

         6.02 CONTROL OF AUDITS AND APPEALS.

                  (a) SEPARATE CONTESTS. Any Separate Contest shall be
controlled solely by the Party involved in the Tax Contest.

                                       12
<PAGE>   16

                  (b) JOINT CONTESTS. With respect to any Joint Contest, the
Party that filed the Return shall control the proceeding. The personnel and
outside advisers (including counsel) of the Party not controlling the proceeding
may participate, at the expense of such Party, in the proceeding to the extent
such proceeding relates to items or adjustments for which such Party may incur
indemnity liability under this Agreement. Such participation shall be reflected
by the grant of appropriate powers of attorney. The Party granting such power of
attorney (the "Granting Party") shall have the right to revoke the power of
attorney if the Granting Party reasonably determines that the actions or failure
to act on the part of the other Person (the "Participating Party") in the
proceeding has resulted, or can be reasonably expected to result, in the
hindrance or delay of any resolution or settlement of the proceeding. In the
event the Participating Party fails to participate timely and fully in any
proceeding to the extent to which such proceeding relates to items or
adjustments for which the Participating Party has indemnity liability under this
Agreement, the Participating Party shall be liable for, in addition to all Taxes
for which the Participating Party shall be liable under this Agreement, any and
all costs imposed on, or incurred by, the Granting Party as a result of the
Participating Party's failure to participate. The revocation of any power of
attorney under this Section 6.02 shall in no way limit the Participating Party's
indemnity liability under this Agreement.

         6.03 CONSENT TO SETTLEMENTS.

                  (a) Subject to Sections 6.03(b) and (c) neither Party shall
agree to any Tax liability or compromise any Tax claim in a Joint Contest for
the account of any member of the other Group without the consent of such other
Party, which consent shall not be withheld unreasonably. Decisions regarding
settlement of a Joint Contest shall be made jointly by the Parties and their
respective representatives.

                  (b) If GenCorp refuses to accept a settlement proposal in a
Joint Contest that OMNOVA wishes to accept, then the contest shall continue, and
(i) OMNOVA's liability to GenCorp with respect to such adjustment shall be
determined as if the settlement proposal had been accepted; (ii) GenCorp shall
indemnify OMNOVA from and against any Taxes resulting from an outcome of the
contest less favorable than the settlement and any other costs resulting from
the continuation of the contest, and (iii) GenCorp shall be entitled to all
benefits resulting from any outcome of the contest that is more favorable than
the settlement (less any costs to OMNOVA, against which GenCorp shall indemnify
OMNOVA).

                  (c) If OMNOVA refuses to accept a settlement proposal in a
Joint Contest that GenCorp wishes to accept, then the contest shall continue and
(i) GenCorp's liability to OMNOVA with respect to such adjustment shall be
determined as if the settlement proposal had been accepted, (ii) OMNOVA shall
indemnify GenCorp from and against any Taxes resulting from an outcome of the
contest less favorable than the settlement and any other costs resulting from
the continuation of the contest, and (iii) OMNOVA shall be entitled to all
benefits resulting from any outcome of the contest that is more favorable than
the settlement (less any costs to GenCorp, against which OMNOVA shall indemnify
GenCorp).

                                       13
<PAGE>   17

         6.04 INFORMATION. Each Party shall provide the other Party with
information pertaining to any increase or decrease in its Taxes that might
affect the liability for Taxes of the other Party for any Period. In addition,
upon reasonable request, each Party shall provide information to the other Party
regarding the Tax treatment of any item.

         6.05 EXPENSES. Each Party shall bear its own Group's expenses incurred
in connection with any Tax Contest.

         6.06 ADVERSE EFFECT ISSUES

                  (a) The procedures set forth in Sections 6.03(c) through
6.06(f) shall apply if -

                      (i) in an examination of a Federal income Tax Return of
one of the Parties or any member of its Group (the "Examined Party"), the IRS
raises one or more Adverse Effect Issues, or

                      (ii) the Examined Party (whether or not in the course of
any audit, examination or other proceeding relating to the determination of its
liability for Federal income Taxes) files an amended Federal income Tax Return
or claim for refund of Federal income Taxes or otherwise takes a position with
the IRS inconsistent with a Federal income Tax Return already filed, if such
amended Federal income Tax Return, claim or position is likely, itself or in
combination with other issues, to be an Adverse Effect Issue.

                  (b) One or more issues are "Adverse Effect Issues" if, in the
reasonable judgment of the Examined Party, the aggregate effect of all such
issues with respect to the Periods within an examination cycle or similar
proceeding of the Examined Party is significantly likely to increase the
liability for Federal income Taxes (less interest) of the Party that is not the
Examined Party and the members of its Group (the "Affected Party") by at least
$250,000. Only for purposes of determining whether an issue is an Adverse Effect
Issue, the amount of such increase in liability for Federal income Taxes shall
be measured under the following principles:

                      (i) All increases (less any offsetting decreases resulting
from the same or a related item) in the Affected Party's liability for Federal
income Tax likely to result from such Adverse Effect Issue for all Periods shall
be taken into account, provided, however, that any decrease in liability for
Federal income Tax that may result from the sale or disposition of property not
expected to be sold or disposed of (for example, stock of an operating
subsidiary), or similar items, shall not be taken into account.

                      (ii) Computations of liability for Federal income Tax
shall be based on the highest marginal rate of Federal income Tax applicable to
the Affected Party for each of the Periods involved.

                      (iii) There shall be taken into account only increases in
liability for Federal income Tax as compared with the return position taken by
the Affected Party.

                                       14
<PAGE>   18

                  (c) In each case, the Parties shall use their reasonable best
efforts to identify issues that are, or in combination with other issues could
become, Adverse Effect Issues.

                      (i) Promptly upon becoming aware that any Adverse Effect
Issue has been raised as described in Section 6.06(a)(i), the Examined Party
shall provide notice of such event to the Affected Party. Such notice shall
include a description of the Adverse Effect Issue, a computation (as described
in Section 6.06(b)(ii) showing the expected increase in the Affected Party's
liability for Federal income Tax resulting therefrom, and copies of all
correspondence between the Examined Party and the IRS (including information
document requests, responses thereto and notices of proposed adjustment).

                      (ii) No less than 30 days before filing any amended return
or claim for refund or taking any action described in Section 6.06(a)(ii), the
Examined Party shall (x) provide notice to the Affected Party (such Notice to
include the information and material listed with respect to the notice provided
in Section 6.06(c)(i) and copies of all amended returns, claims for refund or
other documents proposed to be filed with the IRS with respect to such Adverse
Effect Issue) and (y) consult with the Affected Party regarding such action.

                  (d) Within 30 days after the notice provided in Section
6.06(c)(i) or Section 6.06(c)(ii), the Affected Party may notify the Examined
Party that the Affected Party wishes to participate in proceedings relating to
the disposition of any or all of the Adverse Effect Issues. If the Affected
Party provides such notice, the procedures for Joint Contest set forth in
Section 6.06(b) shall apply, with the Examined Party being in control of the
proceeding. Provided, however, that (i) if the Affected Party does not provide
such notice within such time period, the proceeding shall continue without
participation of the Affected Party and without regard to Sections 6.06(e) and
6.06(f) and (ii) the Affected Party's right to participate in the proceedings
shall terminate if the Examined Party makes a reasonable determination, after
consultation with the Affected Party, that, notwithstanding the Adverse Effect
Items, the total net increase in the Affected Party's liability for Taxes
(determined as set forth in Section 6.06(b)) from all adjustments relating to
the Period or Periods in the examination cycle or similar proceeding is less
than the amount set forth in Section 6.06(b).

                  (e) Subject to Section 6.06(f), the Examined Party shall
settle any Adverse Effect Issue with the IRS only with the prior consent of the
Affected Party. The Parties shall attempt in good faith to agree as to the terms
of a proposed settlement. If the Parties are unable to agree, the procedures set
forth in Section 6.03(b) or Section 6.03(c) as the case may be, shall apply to
such Adverse Effect Issue.

                  (f) Notwithstanding Section 6.06(e), the Examined Party may
settle with the IRS any Adverse Effect Issue without consent of the Affected
Party, if, after consultation with the Affected Party, the Examined Party
reasonably determines that (i) a settlement of such Adverse Effect Issue is
desirable to the Examined Party; (ii) in light of all the circumstances
(including the likelihood of various positions of the Parties being sustained in
further proceedings, the cost of such proceedings and the impact of settlement
on other issues), the overall terms of the settlement do not discriminate
against the Affected Party; and (iii) other

                                       15
<PAGE>   19

issues (which may or may not be Adverse Effect Issues) will be settled, and it
is not practical to settle such other issues on the proposed terms without a
settlement of the Adverse Effect Issue. Before determining that a proposed
settlement of other issues is not practical without a settlement of the Adverse
Effect Issue, the Examined Party will use its reasonable best efforts to secure
a settlement of the other issues while leaving the Adverse Effect Issue open for
further proceedings (for example, by entering into an agreement on IRS Form
870AD or similar form to close proceedings relating to one or more Periods but
reserving the Adverse Effect Issue for further proceedings).

                                   Article VII
                                   -----------
               Special RuleS Pertaining to Gencorp Services, Inc.
               --------------------------------------------------

         7.01 LIABILITY FOR STATE TAXES. Notwithstanding Section 6.02(b), OMNOVA
shall be responsible for, and shall indemnify GenCorp against, (a) all
liabilities for State Taxes of GenCorp Services, Inc., a Ohio corporation
("GSI"), and (b) any liability to GSI or to any member of the GenCorp Group for
adjustments to State Taxes resulting from transactions or arrangements between
GSI and any other member of the GenCorp Group or the OMNOVA Group. Such
liabilities for any Straddle Year in jurisdictions using the unitary method
shall be determined in accordance with Section 2.05(d).

         7.02 GSI TAX RETURNS. Notwithstanding Sections 3.01 and 3.02, OMNOVA
shall file all State Tax Returns for GSI, with the exception of unitary returns
set forth on Schedule 3.01, and any tax audit or other proceeding pertaining to
any State Tax of GSI shall be a Separate Contest of the OMNOVA Group. GenCorp
shall provide notice to OMNOVA of any issue raised by a Tax Authority that could
reasonably result in the application of this Article VIII.

                                  ARTICLE VIII
                                  ------------
                              MISCELLANEOUS MATTERS
                              ---------------------

         8.01 AMENDMENT AND WAIVER. This Agreement shall not be amended or
modified in any manner whatsoever except by a writing executed by each of the
Parties. No failure by either Party to insist upon the strict performance of any
covenant, duty, agreement or condition of this Agreement or to exercise any
right or remedy consequent upon a breach thereof shall constitute waiver of any
such breach or any other covenant, duty, agreement or condition.

         8.02 TAX ALLOCATION AGREEMENTS, ETC. Immediately prior to the
Distribution, GenCorp shall cause any and all tax allocation, tax sharing and
similar agreements or arrangements existing between GenCorp and all members of
the OMNOVA Group to be terminated as of the Distribution Date, and shall cause
any amounts due under such agreements or arrangements to be settled in the
manner agreed to by the Parties prior to the Distribution Date. Upon such
termination and settlement, no further payments made by one Party to the other
with respect to such agreements or arrangements shall be made, and all other
rights and obligations resulting from such agreements or arrangements between
the Parties shall cease as of such time. This Agreement shall supercede any such
agreements or arrangements.

                                       16
<PAGE>   20

         8.03 ENTIRE AGREEMENT; INCONSISTENT PROVISIONS; OTHER AGREEMENTS. The
Parties agree that the Distribution Agreement, this Agreement and the other
Ancillary Agreements (as that term is defined in the Distribution Agreement)
constitutes the entire agreement between them in respect of the subject matter
of this Agreement, and that, in the event of a conflict or other inconsistency
between any provision or term of this Agreement and any other agreement,
including any provision or term of the Distribution Agreement, then insofar as
such matter relates to Taxes, this Agreement shall prevail.

         8.04 AFFILIATE OBLIGATIONS. To the extent that the provisions of this
Agreement pertain to an Affiliate of GenCorp or OMNOVA, GenCorp and OMNOVA
hereby respectively agree that they shall cause such Affiliate to carry out the
terms of this Agreement.

         8.05 FURTHER ACTION. The Parties shall execute and deliver all
documents, provide all information, and take or refrain from taking any action
as may be necessary or appropriate to achieve the purposes of this Agreement.
Without limiting the preceding sentence, the members of each Group shall provide
the members of the other Group with such powers of attorney or other authorizing
documentation as is reasonably necessary to empower then to execute and file Tax
Returns they are responsible for hereunder, file claims for refunds and
equivalent claims for Taxes for which they are responsible, and contest, settle
and resolve any Tax Contests that they control under Article VII.

         8.06 TIME FOR NOTICE. Notice of any indemnification claim under this
Agreement must be received by the Party against which such claim is made no
later than 30 days from the date on which the Taxes to which such claim relates
have been paid.

                  8.07 NOTICES. All notices, demands and other communications
which may or are required to be given to or made by either party to the other in
connection with this Agreement shall be in writing (including telex, fax or
other similar writing) and shall be deemed to have been duly given or made: (a)
if sent by registered or certified mail, five days after the posting thereof
with first class postage attached, (b) if sent by hand or overnight delivery,
upon the delivery thereof and (c) if sent by telex or fax, upon confirmation of
receipt of such telex or fax, in each case addressed to the respective parties
as follows:

         GenCorp:          GenCorp Inc.
                           Highway 50 & Aerojet Road
                           Rancho Cordova, CA    95670
                           Attn:  Secretary

         OMNOVA:           OMNOVA Solutions Inc.
                           175 Ghent Road
                           Fairlawn, Ohio 44333
                           Attn:  Secretary

or to such other address and to the attention of such other persons as either
party hereto may specify from time to time by notice to the other party.

                                       17
<PAGE>   21

         8.08 SUCCESSORS AND ASSIGNS. This Agreement and all of the provisions
hereof shall be binding upon and inure to the benefit of the parties and their
respective successors and assigns; provided, however, that neither this
Agreement nor any of the rights, interests or obligations hereunder shall be
assigned (other than by merger or pursuant to a sale of all or substantially all
of a party's assets to one Person) by either of the parties hereto without the
prior written consent of the other party, which consent shall not be
unreasonably withheld; provided, however, that no such assignment shall relieve
the assigning party of any liabilities or obligations hereunder. Any transfer or
assignment of any of the rights, interests or obligations hereunder in violation
of the terms hereof shall be void and of no force or effect.

         8.09 SEVERABILITY. Any term or provision of this Agreement that is
invalid or unenforceable in any situation in any jurisdiction shall not affect
the validity or enforceability of the remaining terms and provisions hereof or
the validity or enforceability of the offending term or provision in any other
situation or in any other jurisdiction. If the final judgment of a court of
competent jurisdiction declares that any term or provision hereof is invalid or
unenforceable, the court making the determination of invalidity or
unenforceability shall have the power to delete specific words or phrases, or to
replace any invalid or unenforceable term or provision with a term or provision
that is valid and enforceable and that comes closest to expressing the intention
of the invalid or unenforceable term or provision, and this Agreement shall be
enforceable as so modified after the expiration of the time within which the
judgment may be appealed.

         8.10 COUNTERPARTS. This Agreement may be executed simultaneously in
multiple counterparts, each of which shall be deemed an original, but all such
counterparts taken together shall constitute one and the same Agreement.

         8.11 DESCRIPTIVE HEADINGS. The Table of Contents and Article and
Section headings of this Agreement are inserted for convenience only and shall
not constitute a part of this Agreement in construing or interpreting any
provision hereof.

         8.12 NO THIRD-PARTY BENEFICIARIES. Except as provided in Article V
hereto nothing herein, expressed or implied, is intended or shall be construed
to confer upon or give to any Person any legal or equitable right, remedy, claim
or other benefit under or by reason of this Agreement.

         8.13 CONSTRUCTION. It is acknowledged by OMNOVA and GenCorp that this
Agreement has undergone several drafts with the negotiated suggestions of each
and, therefore, no presumptions shall arise favoring either party by virtue of
the authorship of any provision of this Agreement.

         8.14 FORM OF PAYMENTS AND LATE PAYMENTS. Any payments owed by any
member of either Group to any member of the other Group under this Agreement
shall be made in the currency in which the Tax to which such payment relates is
assessed by the Tax Authority, and shall be paid in immediately available funds
and in such other manner as the Person to whom such payment is owed may
reasonably request. Any payments required by this Agreement that

                                       18
<PAGE>   22

are not made when due shall bear interest at the Prime Rate from the due date of
the payment to the date paid.

         8.15 GOVERNING LAW. ALL QUESTIONS CONCERNING THE CONSTRUCTION, VALIDITY
AND INTERPRETATION OF THIS AGREEMENT SHALL BE GOVERNED BY THE INTERNAL LAW, AND
NOT THE LAW OF CONFLICTS, OF THE STATE OF OHIO.

         IN WITNESS WHEREOF, the Agreement has been duly executed as of the day
and year first above written.

                                        GENCORP INC.

                                        By /s/ William R. Phillips
                                          ---------------------------------

                                        Name:   William R. Phillips
                                              -----------------------------

                                        Title:  Senior Vice President
                                              -----------------------------

                                        OMNOVA SOLUTIONS INC.

                                        By /s/ James C. LeMay
                                          ---------------------------------

                                        Name:     James C. LeMay
                                              -----------------------------

                                        Title:    Senior Vice President
                                              -----------------------------

                                       19<PAGE>   1

                                                                 Exhibit 10.16

                                                                  Execution Copy

                    ALTERNATIVE DISPUTE RESOLUTION AGREEMENT
                    ----------------------------------------

         ALTERNATIVE DISPUTE RESOLUTION AGREEMENT (the "Agreement") dated
September 30, 1999 by and between GENCORP INC., an Ohio corporation ("GenCorp")
and OMNOVA Solutions Inc., an Ohio corporation ("OMNOVA").

         This Agreement is made pursuant to the Distribution Agreement dated as
of the date hereof between GenCorp and OMNOVA ("Distribution Agreement"). Each
term used herein that is defined in the Distribution Agreement shall have the
same meaning when used herein as it is given in the Distribution Agreement.

         WHEREAS, GenCorp and OMNOVA have determined that it is necessary and
desirable to agree on the procedures described in this Agreement as the sole and
exclusive method or remedy for them to resolve every dispute, controversy or
claim whether sounding in contract, tort or otherwise (hereinafter "Dispute")
which may from time to time arise under or out of, or is in any way related to,
the Transaction Documents or the Distribution (as herein defined); and,

         WHEREAS, this Agreement shall apply whether such Dispute is based on a
breach of one party or its obligations under the Transaction Documents or
disagreement between the parties as to the meaning or application of the
Transaction Documents or in any manner related to or arising under or out of the
Distribution or the transactions contemplated by the Transaction Documents
(including all actions taken in furtherance of said Distribution).

         NOW, THEREFORE, in consideration of the mutual agreements, provisions
and covenants contained in this Agreement, the parties hereby agree as follows:

                                    ARTICLE I

         As used in this Agreement, the following terms shall have the following
meanings (such meanings to be equally applicable to both the singular and plural
forms of the terms defined):

         AMOUNT IN CONTROVERSY: the monetary value of any Dispute plus the
         monetary value of any related Dispute or series of related Disputes
         then existing or likely to occur in the future.

         APPLICABLE DEADLINE: one year and 45 days after the later of the
         occurrence of the act or event giving rise to the claim underlying the
         Dispute or the date on which such act or event was, or should have
         been, in the exercise of reasonable due diligence, discovered by the
         party asserting the claim; provided, however, that with respect to
         Disputes involving Third Party Claims the applicable act or event shall
         be the making of such Third Party Claim.

<PAGE>   2
                                      -2-

         CPR:  the Center for Public Resources, Inc., New York, NY.

         DEMAND: a written demand for arbitration under Article IV of this
         Agreement which shall contain a statement setting forth the nature of
         the Dispute and the Amount in Controversy.

         DISPUTE:  is defined in the recitals to this Agreement.

         ESCALATION NOTICE: a written notice demanding a meeting of the
         respective Chief Executive Officers of the parties for the purpose of
         resolving a Dispute.

         REQUEST: a written request for mediation under Article III of this
         Agreement which shall set forth the nature of the Dispute and the
         Amount in Controversy.

         TRANSACTION DOCUMENTS: the Distribution Agreement together with the
         Ancillary Agreements and other documents referenced in the Distribution
         Agreement.

                                   ARTICLE II
                             RESOLUTION OF DISPUTES

         Section 2.01. INTENT. It is the intent of the parties to use their
respective reasonable efforts to resolve expeditiously and on a mutually
acceptable negotiated basis any Dispute between them that may arise from time to
time.

         Section 2.02. WAIVER OF RIGHTS. The procedures in this Agreement shall
be the sole and exclusive remedy in connection with any Dispute. Each party to
this Agreement hereby irrevocably waives any rights it may have to trial by jury
or to commence any action in any court of law or equity or before any other
governmental authority with respect to any Dispute, except as expressly
otherwise provided in Sections 4.05(b) and 4.06 of Article IV of this Agreement.

         Section 2.03. PROCEDURE. All Disputes between the parties should be
resolved promptly through consultation and good faith negotiation at the working
levels of GenCorp and OMNOVA. All Disputes which cannot be resolved by the
parties at the working level shall first be subjected to escalation as provided
in Section 2.04 of this Article. If escalation does not resolve the Dispute, the
Dispute shall next be submitted to mediation pursuant to Article III of this
Agreement. Subject to Sections 4.05(b) and 4.06 of Article IV of this Agreement,
if a Dispute cannot be resolved through mediation, then such Dispute shall be
submitted to binding Arbitration pursuant to Article IV of this Agreement.

         Section 2.04. ESCALATION. If the parties are unable to resolve a
Dispute at working levels within GenCorp and OMNOVA, either party may deliver an
Escalation Notice to the other party demanding an in-person meeting for the
purpose of resolving the Dispute between the Chief Executive Officers ("CEOs")
of both parties in Denver, Colorado, within thirty days

<PAGE>   3
                                      -3-

of receipt of the Escalation Notice. The Escalation Notice shall be delivered in
accordance with Section 5.04 of Article V of this Agreement. The CEO's of the
parties shall have fifteen days following their meeting to resolve the Dispute.
If the Dispute is not resolved within the foregoing period, and in any event
after forty-five days following receipt of an Escalation Notice, either party
may initiate mediation of the Dispute in accordance with Article III of this
Agreement.

                                   ARTICLE III
                                    MEDIATION

         Section 3.01. REQUEST FOR MEDIATION. Following completion of the
escalation procedure described in Section 2.04 of Article II of this Agreement,
either party may initiate mediation by delivering a Request to the other party
in accordance with Section 5.04 of Article V of this Agreement.

         Section 3.02. APPOINTMENT OF MEDIATOR. Unless the parties otherwise
agree in writing, a single mediator will be appointed by the two parties from
among the former directors of GenCorp who ceased to be members of the GenCorp
Board of Directors at least six months before the Distribution. In the event the
parties are unable to agree upon a mediator or no such former director is
available, the parties shall apply to CPR to appoint a single mediator from the
CPR Panel of Neutrals, which appointment shall be made by CPR within 15 days
after such application.

         Section 3.03. DATE, TIME AND PLACE. The date, time and place of each
mediation session shall be determined by agreement of the parties or, if the
parties cannot agree within a reasonable period of time, by the mediator;
provided that the first mediation session shall be held within fifteen (15) days
of the date on which the mediator is appointed. Unless the parties otherwise
agree in writing, all mediation proceedings shall take place in Denver,
Colorado.

         Section 3.04. ROLE OF THE MEDIATOR. The mediator shall aid the parties
in their discussions and negotiations by informally advising the parties. Any
opinion expressed by the mediator shall be strictly advisory and shall not be
binding on the parties; provided, however, any final, written opinion expressed
by the mediator shall be admissible in any arbitration proceedings.

         Section 3.05. COSTS OF MEDIATION. Costs of the mediation shall be borne
equally by the parties, except that each party shall be responsible for its own
attorney's fees and expenses.

         Section 3.06. TERMINATION. The mediation proceedings shall be
terminated upon the happening of any of the following: (i) execution of a
settlement agreement by the parties; (ii) receipt of a written declaration of
the mediator that further efforts at mediation are no longer worthwhile; or,
(iii) receipt of a written declaration of one or both parties that the mediation
proceedings are terminated, which is delivered (in accordance with Section 5.04
of Article V of this Agreement) not earlier than completion of the first
mediation session.

<PAGE>   4
                                      -4-

                                   ARTICLE IV
                                   ARBITRATION

         Section 4.01. DEMAND FOR ARBITRATION. (a) At any time after the
termination of mediation as described in Section 3.06 of Article III of this
Agreement, any party may, unless the Applicable Deadline has occurred, make a
Demand that the Dispute be resolved by binding arbitration, which Demand shall
be delivered in the manner set forth in Section 5.04 of Article V of this
Agreement. In the event that any party shall deliver a Demand, the other party
may itself deliver a Demand to such first party with respect to any related
Dispute (with respect to which the Applicable Deadline has not passed) without
the requirement of delivering an Escalation Notice or a Request. In the event
that any party delivers a Demand with respect to any Dispute that is the subject
of any then pending arbitration proceeding or of a previously delivered Demand,
all such Disputes shall be resolved in the arbitration proceeding for which a
Demand was first delivered unless the arbitrator in his or her sole discretion
determines that it is impracticable or otherwise inadvisable to do so.

                  (b) Except as may be expressly provided in any Transaction
Document, any Demand must be given prior to the Applicable Deadline. The parties
may specifically agree in writing to extend or waive the Applicable Deadline
with respect to any Dispute; however, no discussions, negotiations or mediations
between the parties pursuant to this Agreement, or otherwise, will toll the
Applicable Deadline unless expressly agreed in writing by the parties. Each of
the parties agrees that if a Demand is not given prior to the expiration of the
Applicable Deadline, as between or among the parties, such Dispute will be
barred; provided, however, that if there is a Dispute regarding whether the
Applicable Deadline has expired such Dispute shall be resolved by the
Arbitrator. Subject to Sections 4.05(c) and 4.06 of Article IV of this Agreement
and the preceding sentence, upon delivery of a Demand prior to the Applicable
Deadline, the Dispute shall be decided by a sole arbitrator in accordance with
the rules set forth in this Article IV.

         Section 4.02. ARBITRATORS. (a) Within 15 days after a valid Demand is
received, the parties shall attempt to select a sole arbitrator satisfactory to
both parties.

                  (b) In the event that the parties are not able jointly to
select a sole arbitrator within such 15-day period, the parties shall each
appoint an arbitrator (who need not be disinterested as to the parties or the
matter) within 30 days after delivery of the Demand. If one party appoints an
arbitrator within such time period and the other party fails to appoint an
arbitrator within such time period, the arbitrator appointed by the one party
shall be the sole arbitrator of the matter.

                  (c) In the event that a sole arbitrator is not selected
pursuant to paragraph (a) or (b) above and, instead, two arbitrators are
selected pursuant to paragraph (b) above, the two arbitrators will, within 30
days after the appointment of the later of them to be appointed, select an
additional arbitrator who shall act as the sole arbitrator of the dispute. After
selection of such sole arbitrator, the initial arbitrators shall have no further
role with respect to the dispute. In the event that the arbitrators so appointed
do not, within 30 days after the

<PAGE>   5
                                      -5-

appointment of the later of them to be appointed, agree on the selection of the
sole arbitrator, any party involved in such dispute may apply to CPR to select
the sole arbitrator, which selection shall be made by CPR within 30 days after
such application. Any arbitrator selected pursuant to this paragraph (c) shall
be disinterested with respect to any of the parties and the matter and shall be
reasonably competent in the applicable subject matter of the Dispute.

                  (d) The sole arbitrator selected pursuant to paragraph (a),
(b) or (c) above will set a time for the hearing of the matter which will
commence no later than 90 days after the date of appointment of the sole
arbitrator pursuant to paragraph (a), (b) or (c) above and which hearing will be
no longer than 30 days (unless in the judgment of the arbitrator the matter is
unusually complex and sophisticated and thereby requires a longer time, in which
event such hearing shall be no longer than 90 days). The final decision of such
arbitrator will be rendered in writing to the parties not later than 60 days
after the last hearing date, unless otherwise agreed by the parties in writing.

                  (e) The place of any arbitration hereunder will be Denver,
Colorado, unless otherwise agreed by the parties.

         Section 4.03. HEARINGS. Within the time period specified in Section
4.02(d) of Article IV of this Agreement, the matter shall be presented to the
arbitrator at a hearing by means of written submissions of memoranda and
verified witness statements, filed simultaneously, and responses, if necessary
in the judgment of the arbitrator or both parties. If the arbitrator deems it to
be essential to a fair resolution of the dispute, live cross-examination or
direct examination may be permitted, but is not generally contemplated to be
necessary. The arbitrator shall actively manage the arbitration with a view to
achieving a just, speedy and cost-effective resolution of the Dispute. The
arbitrator may, in his or her discretion, set time and other limits on the
presentation of each party's case, its memoranda or other submissions, and
refuse to receive any proffered evidence, which the arbitrator, in his or her
discretion, finds to be cumulative, unnecessary, irrelevant or of low probative
nature. Except as otherwise set forth herein, any arbitration hereunder will be
conducted in accordance with the CPR Rules for Non-Administered Arbitration of
Business Disputes then prevailing (except that the fee schedule of CPR will not
apply). Except as expressly set forth in Section 4.06 of Article IV of this
Agreement, the decision of the arbitrator will be final and binding on the
parties, and judgment thereon may be had and will be enforceable in any court
having jurisdiction over the parties. Arbitration awards will bear interest at
an annual rate of the Prime Rate per annum from the date of the award. To the
extent that the provisions of this Agreement and the prevailing rules of the CPR
conflict, the provisions of this Agreement shall govern.

         Section 4.04. DISCOVERY AND CERTAIN OTHER MATTERS. (a) Any party may
request limited document production from the other party of specific and
expressly relevant documents, with the reasonable expenses of the producing
party incurred in such production paid by the requesting party. Any such
discovery (under which rights to documents shall be substantially less than
document discovery rights prevailing under the Federal Rules of Civil Procedure)
shall be conducted expeditiously and shall not cause the hearing provided for in
Section 4.03 of Article IV of this Agreement to be adjourned except upon consent
of both

<PAGE>   6
                                      -6-

parties or upon an extraordinary showing of cause demonstrating that such
adjournment is necessary to permit discovery essential to a party to the
proceeding. Depositions, interrogatories or other forms of discovery (other than
the document production set forth above) shall be permitted only upon an
extraordinary showing that such discovery is essential to a party to the
proceeding or upon consent of the parties involved in the applicable Dispute.
Disputes concerning the scope of discovery (including document production and
enforcement of the document production requests) will be determined by written
agreement of the parties or, failing such agreement, will be referred to the
arbitrator for resolution. All discovery requests will be subject to the
parties' rights to claim any applicable privilege. The arbitrator will adopt
procedures to protect the proprietary rights of the parties and to maintain the
confidential treatment of the arbitration proceedings (except as may be required
by law). Subject to the foregoing, the arbitrator shall have the power to issue
subpoenas to compel discovery.

                  (b) The arbitrator shall have full power and authority to
determine issues of arbitrability but shall otherwise be limited to interpreting
or construing the applicable provisions of the Transaction Documents, including
this Agreement, and will have no authority or power to limit, expand, alter,
amend, modify, revoke or suspend any condition or provision of any of the
Transaction Documents, including this Agreement; it being understood, however,
that the arbitrator will have full authority to implement the provisions of, and
to fashion appropriate remedies for breaches of, the Transaction Documents
including this Agreement (including interim or permanent injunctive relief);
provided that the arbitrator shall not have: (i) any authority in excess of the
authority a court having jurisdiction over the parties and the Dispute would
have absent these arbitration provisions; or, (ii) any right or power to award
punitive, treble or consequential damages except to the extent that any of such
damages are actually paid by a party or a member of a party's Group to a Person.
It is the intention of the parties that in rendering a decision the arbitrator
give effect to the applicable provisions of the Transaction Documents including
this Agreement, and the laws of the State of Ohio without regard to the
principles of conflicts of law thereof (it being understood and agreed that this
sentence shall not give rise to a right of judicial review of the arbitrator's
award).

                  (c) If a party fails or refuses to appear at and participate
in an arbitration hearing after due notice, the arbitrator may hear and
determine the controversy upon evidence produced by the appearing party.

                  (d) Arbitration costs will be borne equally by each party,
except that each party will be responsible for its own attorney's fees and its
other costs and expenses, including the costs of witnesses selected by such
party and all internal costs.

         Section 4.05. CERTAIN ADDITIONAL MATTERS. (a) Any arbitration award
shall be a bare award limited to a holding for or against a party and shall be
without findings as to facts, issues or conclusions of law (including awards
with respect to any matters relating to the validity or infringement of patents
or patent applications) and shall be without a statement of the reasoning on
which the award rests, but must be in adequate form so that a judgment of a

<PAGE>   7
                                      -7-

court may be entered thereupon. Judgment upon any arbitration award hereunder
may be entered in any court having jurisdiction thereof.

                  (b) Prior to the time at which an arbitrator is appointed
pursuant to Section 4.02 of Section IV of this Agreement, any party may seek one
or more temporary restraining orders in a court of competent jurisdiction if
necessary in order to preserve and protect the status quo. Neither the request
for, or grant or denial of, any such temporary restraining order shall be deemed
a waiver of the obligation to arbitrate as set forth herein and the arbitrator
may dissolve, continue or modify any such order. Any such temporary restraining
order shall remain in effect until the first to occur of the expiration of the
order in accordance with its terms or the dissolution thereof by the arbitrator.

                  (c) In the event that at any time the sole arbitrator shall
fail to serve as an arbitrator for any reason, the parties shall select a new
arbitrator who shall be disinterested as to the parties and the matter in
accordance with the procedures set forth herein for the selection of the initial
arbitrator. The extent, if any, to which testimony previously given shall be
repeated or as to which the replacement arbitrator elects to rely on the
stenographic record (if there is one) of such testimony shall be determined by
the replacement arbitrator.

         Section 4.06. LIMITED COURT ACTIONS. (a) Notwithstanding anything
herein to the contrary, in the event that any party reasonably determines the
amount in controversy in any Dispute (or series of related Disputes) is, or is
reasonably likely to be, in excess of $100 million and if such party desires to
commence a lawsuit in lieu of complying with the arbitration provisions of this
Article IV, such party shall so state in its Demand or by notice given to the
other parties within 20 days after receipt of a Demand with respect thereto. If
the other party to the arbitration does not agree that the amount in controversy
in such Dispute (or series of related Disputes) is, or is reasonably likely to
be, in excess of $100 million, the arbitrator selected pursuant to Section 4.02
hereof shall decide whether the amount in controversy in such Dispute (or series
of related Disputes) is, or is reasonably likely to be, in excess of $100
million. The arbitrator shall set a date that is no later than ten days after
the date of his or her appointment for submissions by the parties with respect
to such issue. There shall not be any discovery in connection with such issue.
The arbitrator shall render his or her decision on such issue within five days
of such date so set to the arbitrator. In the event that the arbitrator
determines that the amount in controversy in such Dispute (or such series of
related Disputes) is, or is reasonably likely to be, in excess of $100 million,
the provisions of Sections 4.01, 4.02, 4.03, 4.04, and 4.05 of Article IV of
this Agreement shall not apply, and on or before (but, except as expressly set
forth in Section 4.06(b), not after) the tenth business day after the date of
such decision, either party to the arbitration may elect, in lieu of
arbitration, to commence a lawsuit with respect to such Dispute in any court of
competent jurisdiction. If the arbitrator does not so determine, the provisions
of this Article IV (including with respect to time periods) shall apply as if no
determinations were sought or made pursuant to this Section 4.06(a).

                  (b) In the event that an arbitration award in excess of $100
million is issued in any arbitration proceeding commenced hereunder, any party
may, within 60 days after the date

<PAGE>   8
                                      -8-

of such award, submit the Dispute giving rise thereto to a court of competent
jurisdiction, regardless of whether such party or any other party sought to
commence lawsuit in lieu of proceeding with arbitration in accordance with
Section 4.06(a) of Article IV of this Agreement. In such event, the applicable
court may elect to rely on the record developed in the arbitration or, if it
determines that it would be advisable in connection with the matter, allow the
parties to seek additional discovery or to present additional evidence. Each
party shall be entitled to present arguments to the court with respect to
whether any such additional discovery or evidence shall be permitted and with
respect to all other matters relating to the Dispute.

                  (c) No party shall raise as a defense the statute of
limitations if the applicable Demand was delivered on or prior to the Applicable
Deadline and, if applicable, if the matter is submitted to a court of competent
jurisdiction within the 60-day period specified in Section 4.06(b) of Article IV
of this Agreement.

         Section 4.07. CONTINUITY OF SERVICE AND PERFORMANCE. Unless otherwise
agreed in writing, the parties will continue to provide service and honor all
other commitments under the Transaction Documents during the course of
arbitration pursuant to the provisions of this Article IV with respect to all
matters not subject to such Dispute.

                                    ARTICLE V
                                  MISCELLANEOUS

         Section 5.01. COMPLETE AGREEMENT; CONSTRUCTION. This Agreement and the
Transaction Documents and other agreements and documents referred to therein,
shall constitute the entire agreement between the parties with respect to the
subject matter hereof and shall supersede all previous negotiations, commitments
and writings with respect to such subject matter.

         Section 5.02. SURVIVAL OF AGREEMENTS. All covenants and agreements of
the parties contained in this Agreement shall survive the Distribution Date.

         Section 5.03. GOVERNING LAW. This Agreement shall be governed by and
construed in accordance with the laws of the State of Ohio without regard to the
principles of conflicts of law thereof.

         Section 5.04. NOTICE. All notices and other communications required or
permitted to be given or made under this Agreement shall, unless otherwise
provided herein, be in writing and shall be deemed to have been given: (i) on
the date of personal delivery; or, (ii) provided such notice or communication is
actually received by the party to which it is addressed in the ordinary course
of delivery, on the date of (A) deposit in the United States mail, postage
prepaid, by registered or certified mail, return receipt requested, (B)
transmission by telegram, cable, telex or facsimile transmission, or (C)
delivery to a nationally-recognized overnight courier service, in each case
addressed as set forth below, or to such other person, entity or address as
either party shall designate by notice to the other in accordance herewith:

<PAGE>   9
                                      -9-

                           To GenCorp:      GenCorp Inc.
                                            Highway 50 & Aerojet Road
                                            Rancho Cordova, CA  95670
                                            Attention:  General Counsel

                           To OMNOVA:       Omnova Solutions Inc.
                                            175 Ghent Road
                                            Fairlawn, Ohio 44333-3300
                                            Attention:  General Counsel

         Section 5.05. WAIVER. No waiver by any party of any of the provisions
of this Agreement will be deemed, or will constitute, a waiver of any other
provision, whether similar, not will any waiver constitute a continuing waiver.
No waiver will be binding unless executed in writing by the party making the
waiver.

         Section 5.06. ASSIGNMENT. Neither party may assign, by operation of
law, merger or otherwise, license, sublicense or otherwise transfer any or all
of its rights or obligations under this Agreement to any other person or entity
without obtaining the prior written consent of the other party.

         Section 5.07. AMENDMENTS. This Agreement may not be modified or amended
except by an agreement in writing signed by the parties.

         Section 5.08. SUCCESSORS AND ASSIGNS. This Agreement and all of the
provisions hereof shall be binding upon and inure to the benefit of the parties
and their respective successors and permitted assigns.

         Section 5.09. SUBSIDIARIES. Each of the parties hereto shall cause to
be performed, and hereby guarantees the performance of, all actions, agreements,
and obligations set forth herein or arising hereunder to be performed by any
member of such parties' Group on and after the Distribution Date.

         Section 5.10. NO THIRD PARTY BENEFICIARIES. This Agreement is solely
for the benefit of the parties hereto and their respective Group members and
shall not be deemed to confer upon third parties any remedy, claim, right or
reimbursement or other right.

         Section 5.11. TITLES AND HEADINGS. Titles and headings to articles and
sections herein are inserted for the convenience of reference only and are not
intended to be a part of or to affect the meaning or interpretation of this
Agreement.

         Section 5.12. CONFIDENTIALITY. Except as required by law, the parties
shall hold, and shall cause their respective officers, directors, employees,
agents and other representatives to hold, the existence, content and result of
any escalation, mediation or arbitration in confidence in accordance with the
requirements of the Transaction Documents, except as may be required

<PAGE>   10
                                      -10-

in order to enforce any award. Each of the parties shall request that any
mediator or arbitrator comply with such confidentiality requirement.

         Section 5.13. SEVERABILITY. Any provision of this Agreement that is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof. Any such prohibition or
unenforceability in any jurisdiction shall not invalidate or render
unenforceable such provision in any other jurisdiction. Without prejudice to any
rights or remedies otherwise available to any party hereto, each party
acknowledges that damages would be an inadequate remedy for any breach of the
provisions of this Agreement and agrees that the obligations of the parties
hereunder shall be specifically enforceable.

         IN WITNESS WHEREOF, the parties have caused this Agreement to be duly
executed as of the day and year first above written.

                                     GENCORP INC.

                                     By: /s/ William R. Phillips
                                        ------------------------------------

                                     Name:  William R. Phillips
                                            --------------------------------

                                     Title:     Senior Vice President
                                            --------------------------------

                                     OMNOVA SOLUTIONS INC.

                                     By: /s/ James C. LeMay
                                        ------------------------------------

                                     Name:  James C. LeMay
                                            --------------------------------

                                     Title:    Senior Vice President
                                            --------------------------------

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