US4180447A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of hard plastic foams using a polyvinylchloride base
Assignee: Lonza AG
•
Filing: 1978-09-11
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Granted: 1979-12-25
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Expires: 1998-09-11
Abstract
Abstract A process for the production of hard plastic foams, using a polyvinylchloride base, from a mixture of polyvinylchloride, at least one temporary softener and at least one expansion agent, wherein the mixture is heated, cooled and expanded. A polymerizable ethylenically unsaturated monomer having at least one double linkage is used as the softener. The polymerization of such monomer is carried out after complete expansion by means of ionizing rays.
Inventors
- 👤 Drago Sencar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:33
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/36; C08F; C08F259/00; C08F259/02; C08F259/04; C08J9/0061; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
88 words
A process for the production of hard plastic foam, using a polyvinylchloride base, from a mixture of polyvinylchloride, at least one temporary softener and at least one expansion agent, wherein the mixture is heated, cooled and expanded, the improvement consisting of using at least one polymerizable ethylenically unsaturated monomer having at least one double linkage as a softener and conducting the polymerization of said polymerizable monomer, after completion of the expansions, by means of ionizing rays, the dosage of the ionizing rays being between 3 and 15 megarads.
Claim 2
Dependent Claim
88 words
A process for the production of hard plastic foam, using a polyvinylchloride base, from a mixture of polyvinylchloride, at least one temporary softener and at least one expansion agent, wherein the mixture is heated, cooled and expanded, the improvement consisting of using at least one polymerizable ethylenically unsaturated monomer having at least one double linkage as a softener and conducting the polymerization of said polymerizable monomer, after completion of the expansions, by means of ionizing rays, the dosage of the ionizing rays being between 3 and 15 megarads.
Claim 3
Dependent Claim
27 words
A process as described in claim 1 wherein said polymerizable monomers are used in a quantity of 10 to 50 percent by weight, based on the polyvinylchloride.
Claim 4
Dependent Claim
22 words
A process as described in claim 1 where said polymerizable monomer is a lower alkyl ester of acrylic acid and/or methacrylic acid.
Claim 5
Dependent Claim
22 words
A process as described in claim 1 wherein said polymerizable monomer is an acrylic acid ester and/or methacrylic acid esters of glycol.
Claim 6
Dependent Claim
15 words
A process as described in claim 1 wherein said polymerizable monomer is a vinyl compound.
Claim 7
Dependent Claim
15 words
A process as described in claim 1 wherein said polymerizable monomer is an allyl compound.
Claim 8
Dependent Claim
23 words
A process as described in claim 1 wherein a mixture of a prepolymer in said polymerizable monomer is used as said polymerizable monomer.
Claim 9
Dependent Claim
16 words
A process as described in claim 1 wherein electron rays are used as said ionizing rays.
Claim 10
Dependent Claim
21 words
A process as described in claim 1 wherein the radiation dosage of the ionizing rays is between 3 and 15 megrads.
Claim 11
Dependent Claim
23 words
A process as described in claim 1 wherein the hard plastic foam has a foam density between 60 and 100 kg/cm 3 .
Claim 12
Dependent Claim
23 words
A process as described in claim 1 wherein the hard plastic foam has a foam density between 60 and 80 kg/cm 3 .
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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) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |