# US 11,111,329 B2 · Preparation of an aqueous dispersion of copolymer particles of vinyl acetate and a cyclic ketene acetal monomer

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- Number: US 11,111,329 B2
- Document ID: US11111329B2
- Status: Granted
- Kind: B2
- Application number: 16/822,292
- Filed: 2020-03-18
- Published: 2020-10-15
- Granted: 2021-09-07
- Earliest claimed: 2019-04-10
- Assignees: Rohm and Haas Company
- Applicants: Rohm and Haas Company
- Inventors: Matthew Carter; Ralph C. Even; Andrew Hejl
- Web page: https://patentgrep.com/patent/US11111329B2

## CPC

- C08F 18/08: Vinyl acetate
- C08F 218/08: Vinyl acetate
- C08G 63/005: {Polyesters prepared from ketenes}
- C08G 63/688: containing sulfur
- C08L 31/04: Homopolymers or copolymers of vinyl acetate
- C08F 2800/20: as weight or mass percentages
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

The present invention relates to a method comprising the steps of a) contacting under emulsion polymerization conditions vinyl acetate; a cyclic ketene acetal monomer; and a monoethylenically unsaturated acid monomer or a salt thereof; to form an aqueous dispersion of copolymer particles comprising structural units of vinyl acetate, the cyclic ketene acetal, and the monoethylenically unsaturated acid monomer or a salt thereof; wherein the cyclic ketene acetal monomer is characterized by following structure: where n and the R groups are as defined herein. The method of the present invention provides a water-borne dispersion that is substantially free of volatile organic solvents and that provides a readily degradable polymer that is useful, for example, in the manufacture of biodegradable packaging products.

## Claims

### Claim 1

A method for preparing an aqueous dispersion of vinyl acetate-cyclic ketene acetal copolymer particles comprising the steps of:
a) contacting under emulsion polymerization conditions at a temperature in the range of from 30° C. to 55° C., and at a pH in the range of from 6.0 to 9.0:
1) 75 to 98.5 parts by weight of vinyl acetate;
2) 1 to 20 parts by weight of a cyclic ketene acetal monomer; and
3) 0.05 to 5 parts by weight of a monoethylenically unsaturated acid monomer or a salt thereof; to form an aqueous dispersion of copolymer particles comprising structural units of vinyl acetate, the cyclic ketene acetal, and the monoethylenically unsaturated acid monomer or a salt thereof;
wherein the cyclic ketene acetal monomer is the following structure:
where n is 0, 1, or 2;
R is H or C1-C6-alkyl;
R1 and R2 are each independently H, C1-C12-alkyl, phenyl, or vinyl; or R1 and R2 together with the carbon atoms to which they are attached, form a fused benzene ring or a fused C3-C7 cycloaliphatic ring; and
R1′ and R2′ are each independently H or C1-C12-alkyl; or R1 and R1′ and/or R2 and R2′ form an exocyclic double bond;
with the proviso that when n is 1:
R3 and R3′ are each independently H, C1-C12-alkyl, phenyl, or R3 and R3′ form an exocyclic double bond or a spirocycloaliphatic group or spiro-2-methylene-1,3-dioxepane group;
with the proviso that when n is 2:
each R3 is H, C1-C2-alkyl, or together with the carbon atoms to which they are attached form a double bond, a fused benzene ring, or a fused C3-C7-cycloaliphatic ring.

### Claim 2 (depends on 1)

The method of claim 1 wherein the cyclic ketene acetal monomer, the vinyl acetate, and the monoethylenically unsaturated acid monomer or a salt thereof are contacted under emulsion polymerization conditions at a temperature in the range of from 35° C. to 55° C., and at a pH in the range of from 6.5 to 8.5.

### Claim 3 (depends on 2)

The method of claim 2 wherein cyclic ketene acetal monomer is selected from the group consisting of:

### Claim 4 (depends on 3)

The method of claim 3 wherein the cyclic ketene acetal monomer is 2-methylene-1,3-dioxepane, and the monoethylenically unsaturated acid monomer is a sulfur acid containing monomer or a salt thereof; wherein the 2-methylene-1,3-dioxepane, the vinyl acetate, and the sulfur acid containing monomer or a salt thereof are contacted under emulsion polymerization conditions at a temperature in the range of from 35° C. to 50° C. and at a pH in the range of from 7.5 to 8.5; wherein the aqueous dispersion of polymer particles comprises structural units of vinyl acetate and 2-methylene-1,3-dioxepane.

### Claim 5 (depends on 4)

The method of claim 4 wherein the sulfur acid containing monomer or salt thereof is selected from the group consisting of 2-acrylamido-2-methyl-1-propanesulfonic acid, salts of 2-acrylamido-2-methyl-1-propanesulfonic acid, vinyl sulfonic acid, salts of vinyl sulfonic acid, 2-sulfoethyl acrylate, 2-sulfoethyl methacrylate, 3-sulfopropyl acrylate, 3-sulfopropyl methacrylate, sodium styrene sulfonate, 2-propene-1-sulfonic acid and salts of 2-propene-1-sulfonic acid.

### Claim 6 (depends on 5)

The method of claim 5 wherein the sulfur acid containing monomer or salt thereof is a salt of 2-acrylamido-2-methyl-1-propanesulfonic acid.

### Claim 7 (depends on 6)

The method of claim 6 wherein the aqueous dispersion of polymer particles further comprises less than 20 weight percent 4-hydroxybutyl acetate based on the weight of structural units of 2-methylene-1,3-dioxepane in the polymer particles; wherein the 2-methylene-1,3-dioxepane, the vinyl acetate, and the sulfur acid containing monomer or a salt thereof are contacted under emulsion polymerization conditions at a temperature in the range of from 35° C. to 45° C.

### Claim 8 (depends on 4)

The method of claim 4 wherein the aqueous dispersion of polymer particles further comprises less than 10 weight percent 4-hydroxybutyl acetate based on the weight of structural units of 2-methylene-1,3-dioxepane in the polymer particles.

### Claim 9 (depends on 5)

The method of claim 5 wherein the aqueous dispersion of polymer particles further comprises less than 2 weight percent 4-hydroxybutyl acetate based on the weight of structural units of 2-methylene-1,3-dioxepane in the polymer particles.

### Claim 10 (depends on 7)

The method of claim 7 wherein the aqueous dispersion of polymer particles further comprises less than 1 weight percent 4-hydroxybutyl acetate based on the weight of structural units of 2-methylene-1,3-dioxepane in the polymer particles.