US3696172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing styrene polymers having a high impact strength
Assignee: NIHON POLYSTYRENE KOGYO KK
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Filing: 1970-10-19
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Granted: 1972-10-03
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Expires: 1990-10-19
Abstract
Abstract Process for the production of high impact polystyrenic polymers comprising dissolving 3-10 parts by weight of a polybutadiene rubber and/or a styrene butadiene rubber in 100 parts of a styrenic monomer, polymerizing the solution under conditions of bulk polymerization in the absence of a catalyst or initiator until the solid content in the solution becomes from about 15 to 45 percent by weight, dispersing the polymerization product in water to provide an aqueous suspension, and polymerizing the aqueous suspension under the conditions of suspension polymerization in the presence of from 0.1 to 1 part by weight of t-butyl per-iso-butyrate and from 0.01 to 0.5 parts by weight of t-butyl peracetate.
Inventors
- 👤 Isao Kaiho
- 👤 Hiroshi Shimizu
- 👤 Hiroshi Osuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:25
CPC Classifications
C; C08; C08F; C08F279/00; C08F279/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
11 words
The process of claim 1 wherein the rubber is polybutadiene rubber.
Claim 2
Dependent Claim
11 words
The process of claim 1 wherein the rubber is styrene-butadiene rubber.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein said rubber is a mixture of polybutadiene and styrene-butadiene rubber.
Claim 4
Dependent Claim
19 words
The process of claim 1 wherein said t-butyl perisobutyrate and said t-butyl peracetate are the only catalytic materials present.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein a suspension stabilizer is present in said suspension.
Claim 6
Dependent Claim
23 words
The process of claim 6 wherein said suspension stabilizer is selected from the group consisting of calcium carbonate, magnesium phosphate, and polyvinyl alcohol.
Claim 7
Dependent Claim
31 words
The process according to claim 1 wherein said polymerization is carried out in the presence of n-dodecyl-mercaptan and a lubricant selected from the group consisting of liquid paraffins and n-butyl stearate.
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) | 1975-10-03 | 1976-04-03 | 1976-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-03 | 1980-04-03 | 1980-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-03 | 1984-04-03 | 1984-10-03 | $7700.00 | Window Closed / Lapsed |