US4026828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Foamed thermoset articles and processes
Assignee: Rohm and Haas Co
•
Filing: 1975-06-13
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Granted: 1977-05-31
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Expires: 1995-06-13
Abstract
Abstract Foamed thermoset articles are produced by introducing a thermosettable organic resin, a specific class of blowing agents, inorganic particulate filler, and glass fiber in a mold at a given temperature and pressure, and then lowering the mold pressure to a predetermined reduced pressure to cause foaming, and completing the foaming before gelation. The foamed thermoset articles are also disclosed.
Inventors
- 👤 Leonard H. Smiley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:58
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/0095; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/17
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
170 words
A process for preparing foamed thermoset articles comprising introducing in a mold a molding composition comprising about 90 to 98 parts by weight of a thermosettable organic resin, about 2 to 10 parts by weight blowing agent which chemically decomposes to generate gas at a temperature of about 50° - 160° C. and which does not prevent complete cure of the resin, about 50 to 300 parts by weight inorganic particulate filler, about 15 to 160 parts by weight of glass fiber; molding at about 4 to 10.5 million Newtons-m - 2 at a temperature of about 130° to 160° C. for about 0.1 to 10 seconds until the molding composition fills the mold cavity; reducing the mold pressure to about 0.51 to 2.1 million Newtons-m - 2 without opening the mold cavity, maintaining said reduced pressure for about 30 to 300 seconds at about the same temperature so as to allow foaming at the reduced pressure, causing said foaming to be completed before gelation occurs in the mold cavity.
Claim 2
Dependent Claim
170 words
A process for preparing foamed thermoset articles comprising introducing in a mold a molding composition comprising about 90 to 98 parts by weight of a thermosettable organic resin, about 2 to 10 parts by weight blowing agent which chemically decomposes to generate gas at a temperature of about 50° - 160° C. and which does not prevent complete cure of the resin, about 50 to 300 parts by weight inorganic particulate filler, about 15 to 160 parts by weight of glass fiber; molding at about 4 to 10.5 million Newtons-m - 2 at a temperature of about 130° to 160° C. for about 0.1 to 10 seconds until the molding composition fills the mold cavity; reducing the mold pressure to about 0.51 to 2.1 million Newtons-m - 2 without opening the mold cavity, maintaining said reduced pressure for about 30 to 300 seconds at about the same temperature so as to allow foaming at the reduced pressure, causing said foaming to be completed before gelation occurs in the mold cavity.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the blowing agent is selected from the group consisting of ammonium carbonate, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, azobisisobutyronitrile, and 2-t-butylazo-2-cyano-4-methyl pentane.
Claim 4
Dependent Claim
39 words
The process of claim 1 wherein about 0.5 to 3 parts by weight chemical thickener is incorporated in the molding composition, and the molding composition is caused to thicken over a period of at least one day before molding.
Claim 5
Dependent Claim
17 words
The process of claim 3 wherein the molding composition is in the form of sheet molding compound.
Claim 6
Dependent Claim
36 words
The process of claim 1 wherein the thermosettable organic resin composition is selected from the group consisting of unsaturated polyester with monoethylenically unsaturated monomer; monoethylenically unsaturated acrylic monomer with acrylic polymer and polyethylenically unsaturated crosslinking monomer.
Claim 7
Dependent Claim
11 words
Foamed thermoset polyester molding produced by the process of claim 5.
Claim 8
Dependent Claim
25 words
Process of claim 1 wherein the thermosettable organic resin is an acrylic resin comprising monoethylenically unsaturated acrylic monomer, acrylic polymer, and polyethylenically unsaturated crosslinking monomer.
Claim 9
Dependent Claim
25 words
Process of claim 7 wherein the molding composition further includes a chemical thickener and the molding composition is in the form of sheet molding compound.
Claim 10
Dependent Claim
11 words
Foamed thermoset acrylic molding produced by the process of claim 7.
Claim 11
Dependent Claim
10 words
Foamed thermoset article produced by the process of claim 1.
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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) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |