US4042556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of hard vinyl chloride foams
Assignee: Central Glass Co Ltd
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Filing: 1975-04-29
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Granted: 1977-08-16
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Expires: 1995-04-29
Abstract
Abstract This invention relates to a process for the production of hard vinyl chloride resin foams, which comprises mixing a vinyl chloride resin foam forming composition containing or not containing a foaming agent of organic decomposition type with at least one uniformly blended mixture comprising a vinyl chloride resin composition and a foaming agent of organic decomposition type in a larger amount than in the former composition and then subjecting the resulting mixture to foaming.
Inventors
- 👤 Mituji Yoshinaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:38
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/20; C08J3/22; C08J3/226; C08J9/00; C08J9/04; C08J9/06; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/06; C08J2427/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
A process for the production of hard vinyl chloride resin foams, which comprises mixing a vinyl chloride resin foam forming composition comprising 100 parts by weight of vinyl chloride resin, 0.1 to 10 parts by weight of a stabilizer and 0.1 to 1.0 by weight of a foaming agent of organic decomposition type with at least one uniformly blended mixture comprising 100 parts by weight of vinyl chloride resin and 10 to 100 parts by weight of a foaming agent of organic decomposition type in a proportion of 1 to 30 parts by weight of the latter composition to 100 parts by weight of the former composition and then subjecting the resulting mixture to foaming.
Claim 2
Dependent Claim
115 words
A process for the production of hard vinyl chloride resin foams, which comprises mixing a vinyl chloride resin foam forming composition comprising 100 parts by weight of vinyl chloride resin, 0.1 to 10 parts by weight of a stabilizer and 0.1 to 1.0 by weight of a foaming agent of organic decomposition type with at least one uniformly blended mixture comprising 100 parts by weight of vinyl chloride resin and 10 to 100 parts by weight of a foaming agent of organic decomposition type in a proportion of 1 to 30 parts by weight of the latter composition to 100 parts by weight of the former composition and then subjecting the resulting mixture to foaming.
Claim 3
Dependent Claim
33 words
The process of claim 1, wherein the vinyl chloride resin is selected from the group consisting of polyvinyl chloride and copolymers of vinyl chloride-vinyl acetate, vinyl chloride-ethylene-vinyl acetate, vinyl chloride-ethylene and vinyl chloride-propylene.
Claim 4
Dependent Claim
32 words
The process of claim 1, wherein the foaming agent of organic decomposition type is at least one member selected from the group consisting azodicarbonamide, azoisobutyronitrile, azobisformamide, N,N-dinitrosopentamethylenetetramine, p-toluenesulfonyl hydrazide and benzenesulfonyl hydrazide.
Claim 5
Dependent Claim
22 words
The process of claim 1, wherein the uniformly blended mixture contains a vinyl chloride resin composition having an excellent cellular film strength.
Claim 6
Dependent Claim
23 words
The process of claim 4, wherein the vinyl chloride resin composition contains at least one of ordinary plasticizers and vinyl chloride resin modifiers.
Claim 7
Dependent Claim
39 words
The process of claim 5, wherein the vinyl chloride resin modifier is selected from the group consisting of methyl methacrylate-butadiene-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, chlorinated polyethylene, acrylic acid resin and graft copolymer of ethylene-vinyl acetate copolymer and vinyl chloride polymer.
Claim 8
Dependent Claim
33 words
The process of claim 1 wherein the uniformly blended mixture is prepared by blending the components with heating and melting at a temperature of less than the decomposition temperature of the foaming agent.
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) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |