US4110273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blowing agent mixture
Assignee: Bayer AG
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Filing: 1977-09-12
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Granted: 1978-08-29
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Expires: 1997-09-12
Abstract
Abstract The invention refers to a blowing agent composition consisting of 1,4 butan-diol-bis-(carbonic acid ester-benzoic acid anhydride) and silicon dioxide. Silicon dioxide reduces the decomposition temperature of the anhydride while at the same time increasing the yield of gas substantially.
Inventors
- 👤 Wolfgang Cohnen
- 👤 Gerhard Apel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:04
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/08; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S521/00; Y10S521/909
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
131 words
A process for the production of foams from thermoplastic resins comprising (A) mixing (i) granules of a thermoplastic resin selected from the group consisting of a polycarbonate, a polyamide, a polyester and a thermoplastic composition of polyphenylene ether and impact resistant polystyrene, with (ii) 0.1 to 15% by weight based on the weight of the total mixture of a blowing agent mixture comprising (a) 85 to 60 wt.% of 1,4-butane diol-bis-(carbonic acid ester benzoic acid anhydride), and (b) 15 to 40 wt.% of silicon dioxide having a surface area according to B.E.T. of from 50 to 400 m 2 /g and a water loss at 1000° C. for 2 hours of less than 2.5% by weight, and (B) heating the mixture of (A) to a temperature of 160° to 300° C.
Claim 2
Dependent Claim
131 words
A process for the production of foams from thermoplastic resins comprising (A) mixing (i) granules of a thermoplastic resin selected from the group consisting of a polycarbonate, a polyamide, a polyester and a thermoplastic composition of polyphenylene ether and impact resistant polystyrene, with (ii) 0.1 to 15% by weight based on the weight of the total mixture of a blowing agent mixture comprising (a) 85 to 60 wt.% of 1,4-butane diol-bis-(carbonic acid ester benzoic acid anhydride), and (b) 15 to 40 wt.% of silicon dioxide having a surface area according to B.E.T. of from 50 to 400 m 2 /g and a water loss at 1000° C. for 2 hours of less than 2.5% by weight, and (B) heating the mixture of (A) to a temperature of 160° to 300° C.
Claim 3
Dependent Claim
124 words
In a process for producing foamed thermoplastic resins by mixing the resin with a blowing agent and heating the mixture to a temperature above the decomposition temperature of the blowing agent and the softening temperature of the resin, the improvement wherein the blowing agent comprises a mixture of (a) 85 to 60 wt.% of 1,4-butane diol-bis-(carbonic acid ester benzoic acid anhydride) and (b) 15 to 40 wt.% silicon dioxide having a surface area according to B.E.T. of from 50 to 400 m 2 /g and a water loss at 1000° C. for 2 hours of less than 2.5 wt.% whereby the decomposition temperature of the blowing agent is lowered and the gas evolution increased compared to pure 1,4-butane diol-bis-(carbonic acid ester benzoic acid anhydride).
Claim 4
Dependent Claim
124 words
In a process for producing foamed thermoplastic resins by mixing the resin with a blowing agent and heating the mixture to a temperature above the decomposition temperature of the blowing agent and the softening temperature of the resin, the improvement wherein the blowing agent comprises a mixture of (a) 85 to 60 wt.% of 1,4-butane diol-bis-(carbonic acid ester benzoic acid anhydride) and (b) 15 to 40 wt.% silicon dioxide having a surface area according to B.E.T. of from 50 to 400 m 2 /g and a water loss at 1000° C. for 2 hours of less than 2.5 wt.% whereby the decomposition temperature of the blowing agent is lowered and the gas evolution increased compared to pure 1,4-butane diol-bis-(carbonic acid ester benzoic acid anhydride).
References Cited (Backward Citations)
US2819231A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-08-28 | 1982-02-27 | 1982-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-28 | 1986-02-27 | 1986-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-28 | 1990-02-27 | 1990-08-29 | $7700.00 | Window Closed / Lapsed |