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US4005040A
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Foamed and solid rubber-starch graft copolymer compositions and method of preparation
Assignee: United States Department of Agriculture
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Filing: 1975-11-10
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Granted: 1977-01-25
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Expires: 1995-11-10
Abstract
Abstract Starch graft copolymers are prepared in aqueous media by reacting soluble sodium starch xanthate with a polymerizable vinyl monomer and hydrogen peroxide. Foamed rubbers reinforced with starch graft copolymers are prepared, without the need for mechanical frothing, by conducting the starch graft polymerization reaction in the latex emulsion. Nonfoamed rubber compositions are prepared in a similar manner.
Inventors
- 👤 George G. Maher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:36
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08F; C08F251/00; C08J9/04; C08J9/06; C08J9/08; C08J2321/00; C08J2451/00
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
105 words
A method of preparing starch graft copolymers comprising the following steps: a. Preparing an aqueous solution of an alkali metal salt of starch xanthate having a xanthate degree of subsitution of from 0.05 to 3, said aqueous solution having a pH of about 11; b. Reacting in said aqueous solution hydrogen peroxide and a vinyl monomer with said starch xanthate to form a gel of starch graft copolymer, said starch xanthate, hydrogen peroxide, and vinyl monomer being present in amounts such that the pH of the resulting reaction media drops to a value of from about 2 to 7; c. Recovering said starch graft copolymer.
Claim 2
Independent Claim
105 words
A method of preparing starch graft copolymers comprising the following steps: a. Preparing an aqueous solution of an alkali metal salt of starch xanthate having a xanthate degree of subsitution of from 0.05 to 3, said aqueous solution having a pH of about 11; b. Reacting in said aqueous solution hydrogen peroxide and a vinyl monomer with said starch xanthate to form a gel of starch graft copolymer, said starch xanthate, hydrogen peroxide, and vinyl monomer being present in amounts such that the pH of the resulting reaction media drops to a value of from about 2 to 7; c. Recovering said starch graft copolymer.
Claim 3
Dependent Claim
56 words
A method as described in claim 1 from about 3 to ;b 100 moles of vinyl monomer and from about 5 to 170 moles of hydrogen peroxide are reacted per mole of xanthate groups present in the aqueous solution, and wherein the starch xanthate has a xanthate degree of substitution of from about 0.1 to 0.6.
Claim 4
Dependent Claim
68 words
A method as described in claim 1 wherein the starch graft copolymer is recovered by washing the gel described in step (b) in a suitable solvent and drying the resulting solid starch graft copolymer, said solid starch graft copolymer containing from 10% to 98% by weight of the polymerized added vinyl monomer and from 0% to 60% by weight of the sulfur contained in the added starch xanthate.
Claim 5
Dependent Claim
21 words
A method as described in claim 1 wherein the vinyl monomer is acrylonitrile, acrylic acid, acrylamide, methyl acrylate, acrolein, or styrene.
Claim 6
Dependent Claim
21 words
A method as described in claim 2 wherein the vinyl monomer is acrylonitrile, acrylic acid, acrylamide, methyl acrylate, acrolein, or styrene.
Claim 7
Dependent Claim
21 words
A method as described in claim 3 wherein the vinyl monomer is acrylonitrile, acrylic acid, acrylamide, methyl acrylate, acrolein, or styrene.
Claim 8
Dependent Claim
10 words
The product prepared by the method described in claim 1.
Claim 9
Dependent Claim
10 words
The product prepared by the method described in claim 2.
Claim 10
Dependent Claim
10 words
The product prepared by the method described in claim 3.
Claim 11
Dependent Claim
10 words
The product prepared by the method described in claim 4.
Claim 12
Dependent Claim
10 words
The product prepared by the method described in claim 5.
Claim 13
Dependent Claim
10 words
The product prepared by the method described in claim 6.
Claim 14
Independent Claim
109 words
A method of preparing rubber compositions comprising the following steps: a. Preparing an aqueous solution of an alkali metal salt of starch xanthate having a xanthate degree of substitution of from 0.05 to 3, said aqueous solution having a pH of about 11; b. Mixing thoroughly the aqueous solution described in step (a) with a suitable aqueous rubber latex; c. Reacting the components of the mixture described in step (b) with hydrogen peroxide and a vinyl monomer, said starch xanthate, vinyl monomer, hydrogen peroxide and rubber latex being present in amounts such that the pH of the resulting reaction mixture drops below the gel point of the rubber latex.
Claim 15
Independent Claim
109 words
A method of preparing rubber compositions comprising the following steps: a. Preparing an aqueous solution of an alkali metal salt of starch xanthate having a xanthate degree of substitution of from 0.05 to 3, said aqueous solution having a pH of about 11; b. Mixing thoroughly the aqueous solution described in step (a) with a suitable aqueous rubber latex; c. Reacting the components of the mixture described in step (b) with hydrogen peroxide and a vinyl monomer, said starch xanthate, vinyl monomer, hydrogen peroxide and rubber latex being present in amounts such that the pH of the resulting reaction mixture drops below the gel point of the rubber latex.
Claim 16
Dependent Claim
75 words
A method as described in claim 13 wherein from about 0.1 to about 1.0 moles of vinyl monomer, from about 0.1 to about 1.0 moles of hydrogen peroxide, and an amount of starch xanthate containing from about 0.001 to about 0.04 moles of xanthane groups were reacted in the presence of about 100 g. of aqueous rubber latex solids, said starch xanthate having a xanthate degree of substitution of from about 0.1 to about 0.5.
Claim 17
Dependent Claim
37 words
A method of preparing solid rubber compositions as described in claim 13 wherein the reaction mixture described in step (c) is stirred during the reaction thereby preventing a foamed coagulum formation and resulting in a washable curd.
Claim 18
Dependent Claim
21 words
A method as described in claim 13 wherein the starch xanthate has a degree of substitution of from 0.1 to 0.25.
Claim 19
Dependent Claim
20 words
A method as described in claim 15 wherein the starch xanthate has a xanthate degree of subsitution of about 0.25.
Claim 20
Dependent Claim
21 words
A method as described in claim 13 wherein the vinyl monomer is acrylonitrile, acrylic acid, acrylamide, methyl acrylate, acrolein, or styrene.
Claim 21
Dependent Claim
21 words
A method as described in claim 14 wherein the vinyl monomer is acrylonitrile, acrylic acid, acylamide, methyl acrylate, acrolein, or styrene.
Claim 22
Dependent Claim
21 words
A method as described in claim 15 wherein the vinyl monomer is acrylonitrile, acrylic acid, acrylamide, methyl acrylate, acrolein, or styrene.
Claim 23
Dependent Claim
21 words
A method as described in claim 16 wherein the vinyl monomer is acrylonitrile, acrylic acid, acrylamide, methyl acrylate, acrolein, or styrene.
Claim 24
Dependent Claim
21 words
A method as described in claim 17 wherein the vinyl monomer is acrylonitrile, acrylic acid, acrylamide, methyl acrylate, acrolein, or styrene.
Claim 25
Dependent Claim
10 words
The product prepared by the method described in claim 13.
Claim 26
Dependent Claim
10 words
The product prepared by the method described in claim 14.
Claim 27
Dependent Claim
10 words
The product prepared by the method described in claim 15.
Claim 28
Dependent Claim
10 words
The product prepared by the method described in claim 16.
Claim 29
Dependent Claim
10 words
The product prepared by the method described in claim 17.
Claim 30
Dependent Claim
10 words
The product prepared by the method described in claim 18.
Claim 31
Dependent Claim
10 words
The product prepared by the method described in claim 19.
Claim 32
Dependent Claim
10 words
The product prepared by the method described in claim 20.
Claim 33
Dependent Claim
10 words
The product prepared by the method described in claim 21.
Claim 34
Dependent Claim
10 words
The product prepared by the method described in claim 22.
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) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |