Modified vinyl alcohol-based polymer and dispersion stabilizer for suspension polymerization

Patent metadata

Field	Value
Publication number	US-11345768-B2
Application number	US-201916759300-A
Country	US
Kind code	B2
Filing date	Feb 1, 2019
Priority date	Feb 8, 2018
Publication date	May 31, 2022
Grant date	May 31, 2022

Abstract

A modified vinyl alcohol-based polymer including a polyoxyalkylene unit represented by a general formula (I) in a side chain and a carbonyl unit represented by a general formula (II) at a main chain terminal, wherein with respect to a total mole number of monomer units constituting the main chain of the modified vinyl alcohol-based polymer, a ratio of a mole number of monomer units having the polyoxyalkylene unit represented by the general formula (I) in the side chain to is 0.01 mol % to 5 mol %, and a ratio of a mole number of the carbonyl unit represented by the general formula (II) is 0.01 mol % to 0.5 mol %.

First claim

The invention claimed is:

1. A modified vinyl alcohol-based polymer, comprising a polyoxyalkylene unit represented by a general formula (I) in a side chain and a carbonyl unit represented by a general formula (II) at a main chain terminal, wherein with respect to a total mole number of monomer units constituting the main chain of the modified vinyl alcohol-based polymer, a ratio of a mole number of monomer units having the polyoxyalkylene unit represented by the general formula (I) in the side chain is 0.01 mol% to 5 mol%, a ratio of a mole number of the carbonyl unit represented by the general formula (II) is 0.01 mol% to 0.5 mol%, and the modified vinyl alcohol-based polymer comprises a monomer unit represented by a general formula (III)

where R 1 and R 2 are each independently a methyl group, an ethyl group or a hydrogen atom, R 3 is a methyl group or a hydrogen atom. n represents a number of repeating units and is an integer of 1<n<70, R 4 represents a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, one of R 5 and R 6 is a methyl group or an ethyl group, the other of R 5 and R 6 is a hydrogen atom, and m represents a number of repeating units and is an integer of 1<m<30.

2. The modified vinyl alcohol-based polymer according to claim 1 , wherein an ether bond and/or a carbon-carbon bond is interposed between the polyoxyalkylene unit represented by the general formula (I) and the polyvinyl alcohol chain of the main chain.

3. The modified vinyl alcohol-based polymer according to claim 1 , wherein the carbonyl unit represented by the general formula (II) has R 4 which is an alkyl having 1 to 9 carbon atoms, and R 4 which is a hydrogen atom.

4. The modified vinyl alcohol-based polymer according to claim 1 , wherein the carbonyl unit comprises a formyl group.

5. The modified vinyl alcohol-based polymer according to claim 1 , wherein a viscosity-average polymerization degree is 300 to 5,000, as measured according to JIS K6726:1994, and a saponification degree is 65 mol% to 90 mol%; as measured according to JIS K6726:1994.

6. A dispersion stabilizer for suspension polymerization, comprising the modified vinyl alcohol-based polymer according to claim 1 .

7. A method for manufacturing a vinyl-based resin, comprising performing suspension polymerization using the dispersion stabilizer for suspension polymerization according to claim 6 for dispersing a vinyl-based compound monomer or a mixture of a vinyl-based compound monomer and a monomer copolymerizable with the vinyl-based compound monomer in water.

8. A method for manufacturing the modified vinyl alcohol-based polymer according to claim 1 , comprising a step of obtaining a modified vinyl ester-based polymer by copolymerizing a vinyl ester-based monomer with an unsaturated monomer having the polyoxyalkylene unit represented by the general formula (I) in a presence of an aldehyde having the carbonyl unit represented by the general formula (II).

9. The method for producing a modified vinyl alcohol-based polymer according to claim 8 , wherein the step of obtaining the modified vinyl ester-based polymer is performed while introducing a gas containing oxygen.

Assignees

• Denka Company Ltd

Inventors

• Watanabe Wataru

Classifications

• C08F216/06 Primary

  Polyvinyl alcohol {; Vinyl alcohol} · CPC title

• C08F218/08

  Vinyl acetate · CPC title

• C08F14/06

  Vinyl chloride · CPC title

• C08F18/08

  Vinyl acetate · CPC title

• C08F8/12

  Hydrolysis · CPC title