US4031302A
Expired / Lapsed
US
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Process for preparing granular rubber
Assignee: Tosoh Corp
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Filing: 1975-09-25
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Granted: 1977-06-21
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Expires: 1995-09-25
Abstract
Abstract Granular rubber is prepared by allowing a latex mixture of a rubber latex and an aqueous solution of a high molecular weight polyanion containing carboxylate groups and/or hydroxyl groups to fall freely into an aqueous solution of an alkaline earth metal salt and separating the granular rubber which forms.
Inventors
- 👤 Akihiko Shimizu
- 👤 Yasuhiro Sakanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:31
CPC Classifications
C; C08; C08C; C08C1/00; C08C1/14; B; B29; B29B; B29B9/00; B29B9/10; B29K; B29K2021/00; B29K2105/00; B29K2105/25; B29K2105/251; Y; Y10; Y10S; Y10S528/00; Y10S528/931; Y10S528/934; Y10S528/936
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
120 words
A process for preparing granular rubber, which comprises: allowing a latex mixture of a rubber latex and an aqueous solution of a high molecular weight polyanion containing carboxylate groups, hydroxyl groups or a mixture thereof to fall freely drop-wise for a distance of from 1 to 80 cm. into an aqueous solution of an alkaline earth metal salt; wherein: a. from 2 to 8 parts by weight of said polyanion is admixed with 100 parts by weight of rubber in the rubber latex; b. said latex mixture has a viscosity of from 200-8,000 cps; and c. said aqueous solution of an alkaline earth metal salt has a concentration of from 1 to 10 wt. %; and recovering the granular rubber.
Claim 2
Dependent Claim
120 words
A process for preparing granular rubber, which comprises: allowing a latex mixture of a rubber latex and an aqueous solution of a high molecular weight polyanion containing carboxylate groups, hydroxyl groups or a mixture thereof to fall freely drop-wise for a distance of from 1 to 80 cm. into an aqueous solution of an alkaline earth metal salt; wherein: a. from 2 to 8 parts by weight of said polyanion is admixed with 100 parts by weight of rubber in the rubber latex; b. said latex mixture has a viscosity of from 200-8,000 cps; and c. said aqueous solution of an alkaline earth metal salt has a concentration of from 1 to 10 wt. %; and recovering the granular rubber.
Claim 3
Dependent Claim
30 words
The process of claim 1, wherein from 4-6 parts by weight of the high molecular weight polyanion is admixed with 100 weight parts of the rubber in the rubber latex.
Claim 4
Dependent Claim
18 words
The process of claim 1, wherein the viscosity of the latex mixture is from 1,000 to 3,000 cps.
Claim 5
Dependent Claim
19 words
The process of claim 1, wherein the concentration of the alkaline earth metal salt is from 2-6 weight %.
Claim 6
Dependent Claim
26 words
The process of claim 1, wherein said polyanion is selected from the group consisting of sodium alginate, sodium carboxymethyl cellulose, and polyvinyl compounds containing carboxyl groups.
Claim 7
Dependent Claim
11 words
The process of claim 1, wherein said polyanion is sodium polyacrylate.
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) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |