Patent US2449537A successfully refreshed from Google Patents.
Patent US4727093A successfully refreshed from Google Patents.
US4727093A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low density particles of polyphenylene ether resins
Assignee: General Electric Co
•
Filing: 1986-10-27
•
Granted: 1988-02-23
•
Expires: 2006-10-27
Abstract
Abstract Low density particles or beads of polyphenylene ether or polyphenylene ether-polystyrene blends are provided by incorporation of a suitable blowing agent such as pentane into the resin mixture, flowed by expansion of the resin particles by exposure temperatures near the Tg of the blend.
Inventors
- 👤 Richard B. Allen
- 👤 Frederick L. Sanford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:46
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08J9/16; C08J9/18; C08J2325/00; C08J2371/00; C08J2371/08; C08J2371/10; C08J2371/12; C08J2425/00; C08J2471/00; C08J2471/08; C08J2471/10; C08J2471/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
161 words
A process for producing low density polyphenylene ether resin compositions wherein said polyphenylene ether resin may be admixed with up to approximately 98 weight percent of an alkenyl aromatic resin based upon the weight of both resins taken together, comprising the steps of: incorporating a blowing agent in said resin composition wherein the blowing agent is a volatile liquid or gas selected from the group consisting of C 4 to C 7 aliphatic hydrocarbons and C 1 to C 2 fluorocarbons capable of being absorbed by the resin composition and which will vaporize at a temperature below the glass transition temperature of the resin composition, and which is present in an amount sufficient to effect expansion of the resin composition in the next step; expanding the resin composition containing the blowing agent by heating to a temperature between about 100° and 210° C.; thereby providing an polyphenylene ether resin composition having a bulk density less than about 20 lbs./ft 3 .
Claim 2
Dependent Claim
161 words
A process for producing low density polyphenylene ether resin compositions wherein said polyphenylene ether resin may be admixed with up to approximately 98 weight percent of an alkenyl aromatic resin based upon the weight of both resins taken together, comprising the steps of: incorporating a blowing agent in said resin composition wherein the blowing agent is a volatile liquid or gas selected from the group consisting of C 4 to C 7 aliphatic hydrocarbons and C 1 to C 2 fluorocarbons capable of being absorbed by the resin composition and which will vaporize at a temperature below the glass transition temperature of the resin composition, and which is present in an amount sufficient to effect expansion of the resin composition in the next step; expanding the resin composition containing the blowing agent by heating to a temperature between about 100° and 210° C.; thereby providing an polyphenylene ether resin composition having a bulk density less than about 20 lbs./ft 3 .
Claim 3
Dependent Claim
32 words
A process as in claim 1 wherein prior to incorporation of the blowing agent and expansion of the composition, the polyphenylene ether resin composition is in the form of pellets or particles.
Claim 4
Dependent Claim
21 words
A process as in claim 2 wherein said pellets or particles are approximately 10 to 30 U.S. Standard mesh in size.
Claim 5
Dependent Claim
17 words
A process as in claim 1 wherein said polyphenylene ether resin composition consists essentially of polyphenylene ether.
Claim 6
Dependent Claim
41 words
A process as in claim 1 wherein said polyphenylene ether resin composition is comprised of about 10 to 90 parts by weight polyphenylene ether and correspondingly 90 to 10 parts alkenyl aromatic resin per 100 parts by weight of both resins.
Claim 7
Dependent Claim
43 words
A process as in claim 1 wherein said polyphenylene ether is a homopolymer or copolymer comprised primarily of 2,6-dimethyl phenylene units and 2,3,6-trimethyl phenylene units and has an intrinsic viscosity of about 0.1 to 0.7 dl/gm as measured in chloroform at 25° C.
Claim 8
Dependent Claim
24 words
A process as in claim 1 wherein the alkenyl aromatic resin is a homopolymer or copolymer comprised primarily of styrene and substituted styrene units.
Claim 9
Dependent Claim
13 words
A process as in claim 7 wherein said alkenyl aromatic resin is polystyrene.
Claim 10
Dependent Claim
24 words
A process as in claim 1 wherein said polyphenylene ether resin composition is further comprised of a rubbery modifier or a flame retarding agent.
Claim 11
Dependent Claim
30 words
A process as in claim 1 wherein said blowing agent is present in an amount of about 3 to 15 weight percent based upon the weight of the resin composition.
Claim 12
Dependent Claim
26 words
A process as in claim 1 wherein the blowing agent is an aliphatic hydrocarbon selected from the group consisting of pentane, isopentane, pentene, hexane, and heptane.
Claim 13
Dependent Claim
35 words
A process as in claim 1 wherein the blowing agent is a fluorocarbon selected from the group consisting of CCl 3 F, CCl 2 F 2 , CHClF 2 an CClF 2 --CClF 2 .
Claim 14
Dependent Claim
25 words
A process as in claim 1 wherein expansion of the resin composition is accomplished with saturated steam at about the Tg of the resin composition.
Claim 15
Dependent Claim
23 words
A process as in claim 1 wherein the expanded polyphenylene ether composition has a bulk density between 2 and 15 lbs/ft 3 .
Claim 16
Dependent Claim
22 words
A process as in claim 14 wherein the expanded polyphenylene ether composition has a bulk density less than 2 lbs./ft 3 .
References Cited (Backward Citations)
US2442940A
Cited
US2787809A
Cited
US2888410A
Cited
US4532094A
Cited
US4532263A
Cited
US4535100A
Cited
US4579873A
Cited
US4579878A
Cited
US4579710A
Cited
US4579874A
Cited
US4587271A
Cited
US4594208A
Cited
US4598098A
Cited
US4598104A
Cited
US4598100A
Cited
US4598101A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |