US3929753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing high bulk density polyvinyl chloride
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1973-11-13
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Granted: 1975-12-30
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Expires: 1993-11-13
Abstract
Abstract A method for producing polyvinyl chloride having a high bulk density, superior gelling property and superior processability by suspension polymerization of vinyl chloride monomer or a mixture of predominantly vinyl chloride and at least one monomer copolymerizable therewith in the presence of an oil soluble catalyst, wherein the polymerization reaction is initiated in the presence of a partially saponified polyvinyl alcohol having 70 to 80 mol % of saponification degree and 500 to 900 of average degree of polymerization as a suspension stabilizer, and when the polymerization conversion becomes 3 to 40 % by weight, a partially saponified polyvinyl alcohol having 75 to 95 mol % of saponification degree and 1000 or more of average degree of polymerization is added to the polymerization system.
Inventors
- 👤 Iko Itoh
- 👤 Takeshi Sekihara
- 👤 Tomoyuki Emura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:29
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/02; C08F14/04; C08F14/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
141 words
A METHOD FOR PRODUCING POLYVINYL CHLORIDE OR A COPOLYMER OF VINYL CHLORIDE HAVING A HIGH BULK DENSITY BY THE SUSPENSION POLYMERIZATION OF VINYL CHLORIDE ALONE OR A MIXTURE CONSISTING PREDOMINANTLY OF VINYL CHLORIDE AND AT LEAST ONE MONOMER COPOLYMERIZABLE THEREWITH IN THE PRESENCE OF AN OIL SOLUBLE CATALYST WHICH COMPRISES INITIATING THE POLYMERIZATION REACTION IN THE PRESENCE OF (1) A PARTIALLY SAPONIFIED POLYVINYL ACETATE HAVING A DEGREE OF SAPONIFICATION OF 70 TO 80 MOL % AND AN AVERAGE DEGREE OF POLYMERIZATION OF 500 TO 900 AS A SUSPENSION STABILIZER AND IN THE PRESENCE OF SAID OIL SOLUBLE CATALYST, AND WHEN THE POLYMERIZATION CONVERSION REACHES 3 TO 40% BY WEIGHT, ADDING (2) A PARTIALLY SAPONIFIED POLYVINYL ACETATE HAVING A DEGREE OF SAPONIFICATION OF 75 TO 95 MOL &% AND AN AVERAGE DEGREE OF POLYMERIZATION OF 1000 OR MORE TO THE POLYMERIZATION SYSTEM.
Claim 2
Independent Claim
141 words
A METHOD FOR PRODUCING POLYVINYL CHLORIDE OR A COPOLYMER OF VINYL CHLORIDE HAVING A HIGH BULK DENSITY BY THE SUSPENSION POLYMERIZATION OF VINYL CHLORIDE ALONE OR A MIXTURE CONSISTING PREDOMINANTLY OF VINYL CHLORIDE AND AT LEAST ONE MONOMER COPOLYMERIZABLE THEREWITH IN THE PRESENCE OF AN OIL SOLUBLE CATALYST WHICH COMPRISES INITIATING THE POLYMERIZATION REACTION IN THE PRESENCE OF (1) A PARTIALLY SAPONIFIED POLYVINYL ACETATE HAVING A DEGREE OF SAPONIFICATION OF 70 TO 80 MOL % AND AN AVERAGE DEGREE OF POLYMERIZATION OF 500 TO 900 AS A SUSPENSION STABILIZER AND IN THE PRESENCE OF SAID OIL SOLUBLE CATALYST, AND WHEN THE POLYMERIZATION CONVERSION REACHES 3 TO 40% BY WEIGHT, ADDING (2) A PARTIALLY SAPONIFIED POLYVINYL ACETATE HAVING A DEGREE OF SAPONIFICATION OF 75 TO 95 MOL &% AND AN AVERAGE DEGREE OF POLYMERIZATION OF 1000 OR MORE TO THE POLYMERIZATION SYSTEM.
Claim 3
Dependent Claim
106 words
The method according to claim 1, wherein the partially saponified polyvinyl acetate having a degree of saponification of 70 to 80 mol % and an average degree of polymerization of 500 to 900 is used in an amount of 0.01 to 0.2 part by weight on the basis of 100 parts by weight of the monomer and the partially saponified polyvinyl acetate having a degree of saponification of 75 to 95 mol % and an average degree of polymerization of 1000 or more is used in an amount of 0.01 or more part by weight on the basis of 100 parts by weight of the monomer.
Claim 4
Dependent Claim
62 words
The method according to claim 2, wherein both of the partially saponified polyvinyl acetates are used in a weight ratio of 1 : 10 to 10 : 1 and the total amount of both of the partially saponified polyvinyl acetate is in a range of 0.03 to 0.3 part by weight on the basis of 100 parts by weight of the monomer.
Claim 5
Dependent Claim
45 words
The method according to claim 1, wherein the monomer copolymerizable with vinyl chloride is a member selected from the group cOnsisting of ethylene, propylene, vinyl acetate, vinyl propionate, lauryl vinyl ether, isobutyl vinyl ether, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate and octyl acrylate.
Claim 6
Dependent Claim
35 words
The method according to claim 1, wherein the polymerization reaction is conducted in the presence of from 0.005 to 1% by weight of said oil soluble catalyst at a temperature of from 20* to 70*C.
Claim 7
Dependent Claim
41 words
The method according to claim 1, wherein the proportion of water to the monomer to be polymerized is employed in a range of 0.8 to 2.0 parts by weight on the basis of 1 part by weight of the starting monomer.
Claim 8
Dependent Claim
33 words
The method according to claim 5, wherein said oil soluble catalyst is selected from the group consisting of lauroyl peroxide, t-butyl peroxypivalate, diisopropyl peroxydicarbonate, di-sec.-butyl peroxydicarbonate, azobisisobutyronitrile, azobis (2,4-dimethylvaleronitrile), azobis(2,4-dimethyl-4-methoxyvaleronitrile and mixtures thereof.
Claim 9
Dependent Claim
28 words
The method according to claim 1, wherein the partially saponified polyvinyl acetate (2) added to the polymerization system has an average degree of polymerization of 1000 to 3000.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |