Claims
- 1. A polymerization inhibitor composition for the emulsion polymerization of chloroprene comprising a 4-(C1-C3 alkoxy)phenol and a hindered bis(phenol)methane of the formula wherein each R1 is independently selected from the group consisting of C1-C12 alkyl radicals and each R2 is independently selected from the group consisting of H and C1-C12 alkyl radicals, the molar ratio of the alkoxyphenol to the hindered bis(phenol)methane being in the range of 0.5/1-2.5/1.
- 2. The composition of claim 1 wherein the 4-( C1-C3 alkoxy)phenol is 4-methoxyphenol.
- 3. The composition of claim 2 wherein each R1 is independently selected from the group consisting of C3-C12 branched alkyl and cycloalkyl radicals.
- 4. The composition of claim 3 wherein the bis(phenol)methane is 2,2′-methylene-bis(6-tert-butyl-4-methylphenol).
- 5. The composition of claim 3 wherein the bis(phenol)methane is 2,2′-methylene-bis(6-tert-butyl-4-ethylphenol).
- 6. A process for preparing a discoloration-resistant polychloroprene comprising the steps of polymerizing chloroprene monomer in an aqueous emulsion and inhibiting the polymerization step by adding at least 0.0003%, based on the weight of total starting monomer, of a polymerization inhibitor composition comprising a 4-(C1-C3alkoxy)phenol and a hindered bis(phenol)methane of the formula wherein each R1 is independently selected from the group consisting of C1-C12 alkyl radicals and each R2 is independently selected from the group consisting of H and C1-C12 alkyl radicals, the molar ratio of the alkoxyphenol to the hindered (bisphenol)methane being in the range of 0.5/1-2.5/1.
- 7. The process of claim 6 wherein the 4-(C1-C3 alkoxy)phenol is 4-methoxyphenol.
- 8. The process of claim 6 wherein each R1 of the hindered bis(phenol)methane is independently selected form the group consisting of C3-C12 branched alkyl and cycloalkyl radicals.
- 9. The process of claim 8 wherein the hindered bis(phenol)methane is 2,2′-methylene-bis(6-tert-butyl-4-methylphenol).
- 10. The composition of claim 8 wherein the hindered bis(phenol)methane is 2,2′-methylene-bis(6-tert-butyl-4-ethylphenol).
REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/072,218 filed Jan. 22, 1998.
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