Patent US4079107A successfully refreshed from Google Patents.
US4079107A
Expired / Lapsed
US
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Process for the production of extra soft polyvinyl chloride foam plastics
Assignee: Lonza AG
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Filing: 1975-10-06
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Granted: 1978-03-14
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Expires: 1995-10-06
Abstract
Abstract The process for the production of closed-cell, extra soft polyvinylchloride foam plastics having improved volume stability at elevated temperatures. The process includes heating a plastisol or plastigel comprised of a plasticizer and foaming agent containing polyvinyl chloride or vinyl chloride copolymerizate in a pressure mold at a pressure of up to 300 atm. to a temperature of 150° to 180° C. for 1 to 2 hours. The plastigel or plastisol is cooled, at an unchanged closing force of the press of said pressure mold, to a temperature of 20° to 70° C. The plastigel or plastisol is removed from the pressure mold, a crude foam plastic forming. The crude foam plastic is heated under a gas pressure of 2 to 10 atm. to a temperature of 140° to 170° C. The crude foam plastic is cooled at said pressure of 2 to 10 atm. to a temperature of 100° to 130° C. The pressure is lowered to atmospheric pressure, the foam plastic simultaneous expanding. The resultant foam plastic will not shrink or expand more than 5 percent after storage for one week at 60° C.
Inventors
- 👤 Emil Brunner
- 👤 Alfred Huber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:43
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/06; Y; Y10; Y10S; Y10S264/00; Y10S264/60
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
216 words
The process for the production of a closed-cell, extra soft polyvinylchloride foam plastic product having improved volume stability at elevated temperatures which comprises (a) heating a plastisol or plastigel comprised of a plasticizer- and a foaming agent-containing polyvinyl chloride or vinylchloride copolymerizate in a pressure mold at a pressure of up to 300 atm. to a temperature of 150° to 180° C., (b) cooling said plastigel or plastisol, at an unchanged closing force of the press or said pressure mold, to a temperature of 20° to 70° C., (c) removing said cooled plastigel or plastisol from said pressure mold as a crude foam plastic preform, (d) heating said crude foam plastic preform under a gas pressure of 2 to 10 atm. to a temperature of 140° to 170° C., (e) cooling said crude foam plastic preform at said pressure of 2 to 10 atm. to a temperature of 100° to 130° C., and (f) lowering said pressure to atmospheric pressure, said foam plastic preform simultaneously expanding to form said closed-cell extra soft polyvinyl chloride product, step (a) achieving gelation and the decomposition of the foaming agent, step (d) imparting said extra softness and said improved volume stability at elevated temperatures to said polyvinylchloride foam plastic preform and steps (c) and (f) achieving expansion under light pressure.
Claim 2
Dependent Claim
216 words
The process for the production of a closed-cell, extra soft polyvinylchloride foam plastic product having improved volume stability at elevated temperatures which comprises (a) heating a plastisol or plastigel comprised of a plasticizer- and a foaming agent-containing polyvinyl chloride or vinylchloride copolymerizate in a pressure mold at a pressure of up to 300 atm. to a temperature of 150° to 180° C., (b) cooling said plastigel or plastisol, at an unchanged closing force of the press or said pressure mold, to a temperature of 20° to 70° C., (c) removing said cooled plastigel or plastisol from said pressure mold as a crude foam plastic preform, (d) heating said crude foam plastic preform under a gas pressure of 2 to 10 atm. to a temperature of 140° to 170° C., (e) cooling said crude foam plastic preform at said pressure of 2 to 10 atm. to a temperature of 100° to 130° C., and (f) lowering said pressure to atmospheric pressure, said foam plastic preform simultaneously expanding to form said closed-cell extra soft polyvinyl chloride product, step (a) achieving gelation and the decomposition of the foaming agent, step (d) imparting said extra softness and said improved volume stability at elevated temperatures to said polyvinylchloride foam plastic preform and steps (c) and (f) achieving expansion under light pressure.
Claim 3
Dependent Claim
41 words
The process of claim 1 wherein the copolymerizable monomer forming said copolymerizate with said vinyl chloride or said polyvinyl chloride is a vinyl ester, an acrylic acid ester, a methacrylic ester, an olefin or a chlorinated monomer other than vinyl chloride.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the starting material is a plastisol.
Claim 5
Dependent Claim
20 words
The process of claim 1 wherein said heating of step (a) is to a temperature of 160° to 170° C.
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein, after heating step (a) is effected, said temperature and pressure being maintained for 1 to 2 hours.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein a pressure of 100° to 200° C. is achieved in step (a).
Claim 8
Dependent Claim
20 words
The process of claim 1 wherein said cooling of step (b) is to a temperature of 30° to 50° C.
Claim 9
Dependent Claim
20 words
The process of claim 1 wherein said heating of step (d) is to a temperature of 150° to 160° C.
Claim 10
Dependent Claim
21 words
The process of claim 1 wherein after heating step (d) is effected, said temperature being maintained for 0.5 to 1 hour.
Claim 11
Dependent Claim
28 words
The process of claim 1 wherein said pressure in step (d) is achieved by means of air and wherein said step (d) is achieved in a pressure vessel.
Claim 12
Dependent Claim
23 words
The process of claim 10 wherein steam is introduced into said pressure vessel to obtain a relative humidity of 10 to 40 percent.
Claim 13
Dependent Claim
30 words
The process of claim 1 wherein, in step (a), said plastisol is filled into said pressure mold in the form of a heavy foam, obtained by mechanical beating in air.
Claim 14
Dependent Claim
28 words
The process of claim 1 wherein said crude foam plastic preform obtained from step (c) is split and said split pieces are subjected to steps (d) to (f).
Claim 15
Dependent Claim
25 words
The process of claim 1 wherein, in step (a), said pressure mold is completely filled with said plastisol or plastigel before said heating is started.
Claim 16
Dependent Claim
15 words
The process of claim 1 wherein more than one of said pressure molds are used.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |