US4388442A
Expired / Lapsed
US
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Stabilizer or dispersing agent for use in a suspension polymerization of a vinyl compound comprising a modified and partially hydrolyzed anionic polyvinyl alcohol
Assignee: Denka Co Ltd
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Filing: 1980-10-10
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Granted: 1983-06-14
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Expires: 2000-10-10
Abstract
Abstract A stabilizer or dispersing agent for use in a suspension polymerization of a vinyl compound is provided which comprises a modified and partially hydrolyzed polyvinyl alcohol having an average polymerization degree of from 200 to 3,000 and an average hydrolysis degree of from 60 to 90 mol % and including anion hydrophilic groups at the side chains thereof, wherein said anion hydrophilic groups are selected from the group consisting of dicarboxyl groups and/or esters thereof and/or salts thereof, sulfuric esters and/or salts thereof and phosphoric esters and/or salts thereof, and the content of said anion hydrophilic groups is in the range of from 0.02 to 10 mol % per unit mol of the polyvinyl alcohol. A process for preparing a polymer of a vinyl compound is also provided wherein said vinyl compound is polymerized in a suspension thereof suspended by the use of the stabilizer or dispersing agent.
Inventors
- 👤 Yasuo Taniguchi
- 👤 Toshio Asano
- 👤 Haruo Funami
- 👤 Kouichi Itou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:14
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/12; C08F2/16; C08F2/18; C08F2/20
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
112 words
A stabilizer or dispersing agent for use in a suspension polymerization of a vinyl compound, comprising a modified and partially hydrolyzed polyvinyl alcohol having an average polymerization degree of from 200 to 3,000 and an average hydrolysis degree of from 60 to 90 mol% and including anion hydrophilic groups at the side chains thereof, wherein said anion hydrophilic groups are selected from the group consisting of dicarboxyl groups, and/or esters, and/or salts thereof, sulfuric esters and/or salts thereof, and phosphoric esters and/or salts thereof, and mixtures thereof, and the content of said anion hydrophilic groups is in the range of from 0.02 to 10 mol% per unit mol of the polyvinyl alcohol.
Claim 2
Dependent Claim
112 words
A stabilizer or dispersing agent for use in a suspension polymerization of a vinyl compound, comprising a modified and partially hydrolyzed polyvinyl alcohol having an average polymerization degree of from 200 to 3,000 and an average hydrolysis degree of from 60 to 90 mol% and including anion hydrophilic groups at the side chains thereof, wherein said anion hydrophilic groups are selected from the group consisting of dicarboxyl groups, and/or esters, and/or salts thereof, sulfuric esters and/or salts thereof, and phosphoric esters and/or salts thereof, and mixtures thereof, and the content of said anion hydrophilic groups is in the range of from 0.02 to 10 mol% per unit mol of the polyvinyl alcohol.
Claim 3
Dependent Claim
51 words
A stabilizer or dispersing agent as claimed in claim 1, wherein said dicarboxyl groups, and/or esters, and/or salts thereof are introduced into the polyvinyl alcohol by initially preparing a copolymer of vinyl acetate and at least one of an unsaturated dicarboxylic acid and an ester thereof, and then hydrolyzing said copolymer.
Claim 4
Dependent Claim
36 words
A stabilizer or dispersing agent as claimed in claim 2, wherein said unsaturated dicarboxylic acid and/or ester thereof is selected from the group consisting of maleic acid anhydride, maleic diesters and maleic monoesters and mixtures thereof.
Claim 5
Dependent Claim
33 words
A stabilizer or dispersing agent as claimed in claim 3, wherein said ester of unsaturated dicarboxylic acid is selected from the group consisting of dimethyl maleate, monomethyl maleate, diethyl maleate and monoethyl maleate.
Claim 6
Dependent Claim
40 words
A stabilizer or dispersing agent as claimed in claim 1, wherein said sulfuric esters and/or salts thereof are introduced into polyvinyl alcohol by the sulfonation method in which polyvinyl alcohol is treated in a concentrated aqueous solution of sulfuric acid.
Claim 7
Dependent Claim
39 words
A stabilizer or dispersing agent as claimed in claim 1, wherein said sulfuric ester and/or salts thereof are introduced into polyvinyl alcohol by the chlorosulfonation method in which the OH groups of polyvinyl alcohol are condensed with chlorosulfuric acid.
Claim 8
Dependent Claim
40 words
A stabilizer or dispersing agent as claimed in claim 1, wherein said phosphoric esters and/or salts thereof are introduced into polyvinyl alcohol by the esterification method in which polyvinyl alcohol is heated in a concentrated aqueous solution of phosphoric acid.
Claim 9
Dependent Claim
39 words
A stabilizer or dispersing agent as claimed in claim 1, wherein said phosphoric esters and/or salts thereof are introduced into polyvinyl alcohol by the esterification method in which the OH groups of polyvinyl alcohol are condensed with phosphorus oxychloride.
Claim 10
Dependent Claim
22 words
The stabilizer or dispersing agent of claim 1 wherein the polyvinyl alcohol has an average polymerization degree of from 600 to 1,500.
Claim 11
Dependent Claim
24 words
The stabilizer or dispersing agent of claim 9 wherein the polyvinyl alcohol has an average hydrolysis degree of from 60 to 80 mol %.
Claim 12
Dependent Claim
30 words
The stabilizer or dispersing agent of claim 10 wherein said anion hydrophilic groups are in the range of 0.02 to 5 mol % per unit mol of the polyvinyl alcohol.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |