Patent US4277388A successfully refreshed from Google Patents.
US4277388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermoplastic resin of hydrolyzed product of vinyl chloride copolymer for use in coating resin and process for preparing such resin
Assignee: Denka Co Ltd
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Filing: 1979-09-28
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Granted: 1981-07-07
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Expires: 1999-09-28
Abstract
Abstract According to the invention there are provided a thermoplastic resin for use in a coating resin, and a process for preparing such resin, said thermoplastic resin being a hydrolyzed product of a vinyl chloride copolymer obtained by polymerizing 50 to 80% by weight of a vinyl chloride monomer, 20 to 40% by weight of a vinyl ester monomer and 0 to 15% by weight of a comonomer polymerizable with the vinyl chloride monomer, said vinyl chloride copolymer having an average polymerization degree of 200 to 800 and said hydrolyzed product having an absorption ratio of OH/CH in the infrared absorption spectrum of from 0.5 to 0.9.
Inventors
- 👤 Toshio Kagami
- 👤 Yoshijiro Saito
- 👤 Shigeru Matsushita
- 👤 Kunio Iriuchijima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:47
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/12; C08F2800/00; C08F2800/20; C08F2810/00; C08F2810/50; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31645; Y10T428/31649
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
208 words
A process for preparing a thermoplastic resin for use in a coating resin to be coated on a base film of a magnetic recording tape which comprises the steps of: (a) copolymerizing 50 to 80% by weight of a vinyl chloride monomer, 20 to 40% by weight of a vinyl ester monomer and 0 to 15% by weight of a comonomer polymerizable with the vinyl chloride monomer to obtain a vinyl chloride copolymer having an average polymerization degree of 200 to 800; (b) hydrolyzing said vinyl chloride copolymer dissolved in a solvent in the presence of an alcohol until the absorption ratio of OH/CH of the hydrolyzed product in the infrared absorption spectrum reaches 0.5 to 0.9; (c) decoloring the hydrolyzed product; (d) cooling and neutralizing with an organic oxide the solution containing the hydrolyzed product of said vinyl chloride copolymer, said organic oxide being selected from the group consisting of propylene oxide and butylene oxide; and (e) removing the alcohol by distillation at a temperature of 40° C. to 70° C. under a reduced pressure of 50 to 200 Torr until the content of said alcohol in the solution reaches less than 1% by weight, whereby to obtain the hydrolyzed product in the form of a solution.
Claim 2
Dependent Claim
208 words
A process for preparing a thermoplastic resin for use in a coating resin to be coated on a base film of a magnetic recording tape which comprises the steps of: (a) copolymerizing 50 to 80% by weight of a vinyl chloride monomer, 20 to 40% by weight of a vinyl ester monomer and 0 to 15% by weight of a comonomer polymerizable with the vinyl chloride monomer to obtain a vinyl chloride copolymer having an average polymerization degree of 200 to 800; (b) hydrolyzing said vinyl chloride copolymer dissolved in a solvent in the presence of an alcohol until the absorption ratio of OH/CH of the hydrolyzed product in the infrared absorption spectrum reaches 0.5 to 0.9; (c) decoloring the hydrolyzed product; (d) cooling and neutralizing with an organic oxide the solution containing the hydrolyzed product of said vinyl chloride copolymer, said organic oxide being selected from the group consisting of propylene oxide and butylene oxide; and (e) removing the alcohol by distillation at a temperature of 40° C. to 70° C. under a reduced pressure of 50 to 200 Torr until the content of said alcohol in the solution reaches less than 1% by weight, whereby to obtain the hydrolyzed product in the form of a solution.
Claim 3
Dependent Claim
28 words
A process according to claim 1, wherein said vinyl ester monomer is a vinyl ester of an alkyl carboxylic acid, said acid having 2 or more carbon atoms.
Claim 4
Dependent Claim
23 words
A process according to claim 2, wherein said vinyl ester monomer is selected from the group consisting of vinyl acetate and vinyl propionate.
Claim 5
Dependent Claim
41 words
A process according to claim 1, wherein said comonomer is selected from the group consisting of methacrylic acid and esters thereof, acrylic acid and esters thereof, maleic acid, fumaric acid, acrylonitrile, vinylidene chloride and α-olefins having 2 to 9 carbon atoms.
Claim 6
Dependent Claim
28 words
A process according to claim 1, wherein said alcohol used in the hydrolyzing step is selected from the group consisting of methyl alcohol, ethyl alcohol and butyl alcohol.
Claim 7
Dependent Claim
16 words
A process according to claim 5, wherein an acid catalyst is used at the hydrolyzing step.
Claim 8
Dependent Claim
24 words
A process according to claim 6, wherein said acid catalyst is selected from the group consisting of hydrochloric acid, sulfuric acid and phosphoric acid.
Claim 9
Dependent Claim
47 words
A process according to claim 7, wherein said acid catalyst is hydrochloric acid and is added such that the quantity of the hydrochloric acid in a pure state ranges about 2 to 5 parts by weight based on 100 parts by weight of the vinyl chloride copolymer.
Claim 10
Dependent Claim
21 words
A process according to claim 1, wherein the hydrolyzing step is effected at a temperature of 40° C. to 70° C.
Claim 11
Dependent Claim
51 words
A process according to claim 1, wherein the hydrolyzed product is decolored by adding 1 to 2 parts by weight of an organic peroxide to the solution containing 100 parts by weight of the hydrolyzed product and maintaining the solution at 40° C. to 70° C. for 3 to 4 hours.
Claim 12
Dependent Claim
13 words
A process according to claim 10, wherein the organic peroxide is benzoyl peroxide.
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) | 1984-07-06 | 1985-01-05 | 1985-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-06 | 1989-01-05 | 1989-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-06 | 1993-01-05 | 1993-07-07 | $7700.00 | Window Closed / Lapsed |