US3673136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Powdered polysaccharide-reinforced elastomer masterbatches, compounds, and resulting vulcanized rubbers
Assignee: United States Department of Agriculture
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Filing: 1970-07-24
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Granted: 1972-06-27
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Expires: 1990-07-24
Abstract
Abstract Powdered elastomer masterbatches are prepared by grinding dried rubber curds which contain highly effective reinforcing agents. Such finely comminuted elastomer masterbatches provide stable powdered rubber compounds when blended with usual powdered curatives and fine particle fillers. These powdered rubber compounds are formed into finished vulcanized rubber articles by direct heat-compression molding, by extrusion from a simple machine, or by injection molding without prior high shear mixing.
Inventors
- 👤 Russell A Buchanan
- 👤 Charles R Russell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:32
CPC Classifications
C; C08; C08L; C08L9/00; C08L9/06; C08L9/08; C08J; C08J3/00; C08J3/20; C08J3/22; C08J3/226; C08L21/00; C08L9/02; C08L9/04; C08J2409/00; C08L3/00; C08L3/02; C08L97/00; C08L97/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
59 words
Powdered zinc starch xanthate-SBR elastomer masterbatches containing from 20 to 45 phr starch, having nearly all particles below 1,410 Mu diameter and more than 45 weight percent below 350 Mu diameter, and which provide vulcanized rubbers having greater than about 710 p.s.i. tensile strength, greater than about 63 Shore A hardness, and greater than about 40 percent ultimate elongation.
Claim 2
Dependent Claim
65 words
Powdered lignin-starch xanthide-SBR elastomer masterbatches containing from 15 to 30 phr starch and from 13 to 26 phr lignin, having nearly all particles below 1,410 Mu diameter and more than 63 weight percent below 840 Mu diameter, and which provide vulcanized rubbers having greater than about 980 p.s.i. tensile strength, greater than about 67 Shore A hardness, and greater than about 200 percent ultimate elongation.
Claim 3
Dependent Claim
65 words
Powdered zinc starch xanthate-oil-extended SBR elastomer masterbatch containing about 20 phr starch based on total oil plus SBR polymer, having nearly all particles below 1,410 Mu diameter and more than 54 weight percent below 350 Mu diameter, and which provides vulcanized rubbers having greater than about 600 p.s.i. tensile strength, greater than about 49 Shore A hardness, and greater than about 250 percent ultimate elongation.
Claim 4
Independent Claim
116 words
A method for making free-flowing powdered polysaccharide-reinforced elastomer masterbatches capable of forming vulcanized rubber products by heat-compression or injection molding with little or no prior phase reversion which comprises: a. coprecipitating a polysaccharide selected from the group consisting of starch xanthide, zinc starch xanthate, lignin and starch xanthate in combination, and their cereal flour analogs with an elastomer selected from the group consisting of styrene-butadiene rubber, oil-extended styrene-butadiene rubber and nitrile rubber; b. drying the resulting coprecipitates; c. grinding the dried coprecipitates to a free-flowing powder in which substantially all particles have diameters of less than 1,410 Mu ; and d. optionally blending the powdered coprecipitates with normally used rubber curatives, fillers, extenders, or reinforcing agents.
Claim 5
Dependent Claim
48 words
Reinforced vulcanized rubber prepared from powdered starch xanthide-SBR elastomer masterbatches described in claim 1 blended with normally used rubber curatives, said rubber being characterized as having greater than about 760 p.s.i. tensile strength, greater than about 70 Shore A hardness, and greater than about 130 percent ultimate elongation.
Claim 6
Dependent Claim
49 words
Reinforced vulcanized rubber prepared from powdered zinc starch xanthate-SBR elastomer masterbatches described in claim 2 blended with normally used rubber curatives, said rubber being characterized as having greater than about 710 p.s.i. tensile strength, greater than about 63 Shore A hardness, and greater than about 40 percent ultimate elongation.
Claim 7
Dependent Claim
48 words
Reinforced vulcanized rubber prepared from powdered lignin-starch xanthide-SBR elastomer masterbatches described in claim 3 blended with normally used rubber curatives, said rubber being characterized as having greater than about 980 p.s.i. tensile strength, greater than about 67 Shore A hardness, and greater than about 200 percent ultimate elongation.
Claim 8
Dependent Claim
48 words
Reinforced vulcanized rubber prepared from powdered zinc-starch xanthate-oil-extended-SBR elastomer masterbatches described in claim 4 blended with normally used rubber curatives, said rubber being characterized as having greater than about 600 p.s.i. tensile strength, greater than about 49 Shore A hardness, and greater than about 250 percent ultimate elongation.
References Cited (Backward Citations)
US3113605A
Cited
US3015640A
Cited
US3294720A
Cited
US3442832A
Cited
US3533988A
Cited
US3542708A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |