Polymer epoxidation process

DETAILED DESCRIPTION I claim: 1.
A process for the production of epoxidized polymers substantially free of gel which comprises contacting: (a) a rubbery polymer of a conjugated diene in (b) an aliphatic or alicyclic hydrocarbon diluent capable of dissolving said rubbery polymer with (c) hydrogen peroxide and (d) a mixture of formic acid and at least one other low molecular weight monocarboxylic acid under epoxidation conditions which produce substantially gel-free epoxidized rubbery polymers of conjugated diene.
2.
A process according to claim 1 wherein the ratio (molar) of formic acid to said other acid ranges from about 3:2 to about 1:10 and said other acid has from 2 to 9, inclusive, carbon atoms per molecule.
3.
A process according to claim 1 wherein said diluent has a boiling point in the range of about 35.
degree.
to about 150.
degree.
C.
, the amount of hydrogen peroxide ranges from about 1 to about 2 moles per mole of olefinic unsaturation in the polymer to be epoxidized, and the temperature during epoxidation is in the range of about -10.
degree.
C.
to about 120.
degree.
C.
4.
A process according to claim 1 wherein said rubbery polymer is selected from homopolymers of conjugated dienes having from 4 to 12, inclusive, carbon atoms and copolymers of said conjugated dienes and monovinylarenes having from 8 to 20, inclusive, carbon atoms, and wherein said polymers have a number average molecular weight in the range of about 5,000 to about 400,000.
5.
A process according to claim 1 wherein (a) is a rubbery polymer selected from homopolymers of conjugated dienes having from 4 to 12 carbon atoms and copolymers of said conjugated dienes and monovinylarenes having from 8 to 20 carbon atoms, (b) is a hydrocarbon diluent having a boiling point ranging from about 35.
degree.
C.
to about 150.
degree.
C.
, (c) the amount of hydrogen peroxide present ranges from about 1 to about 2 moles per mole of olefinic unsaturation in the polymer to be epoxidized, (d) the molar ratio of formic acid to said other acid ranges from about 3:2 to about 1:10, and further wherein the temperature of said contacting is in the range of about -10