Patent US4420570A successfully refreshed from Google Patents.
US4420570A
Expired / Lapsed
US
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Reaction injection molded elastomer containing an internal mold release made by a two-stream system
Assignee: Huntsman Corp
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Filing: 1982-09-13
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Granted: 1983-12-13
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Expires: 2002-09-13
Abstract
Abstract The invention is a method of making a molded reaction injection molded elastomer which will release from its mold with reduced frequency of application of external mold release agents. The reaction injection molded (RIM) elastomer is made by injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream a high molecular weight polyhydric polyether, a low molecular weight active hydrogen containing compound of at least two functionality and an internal mold release agent, and in the second stream an aromatic polyisocyanate and tin catalyst in an amount equal to 100% of the tin catalyst present in the formulation. The resulting RIM elastomer may be removed from the mold easily. RIM elastomers are useful, for example, for automobile body parts.
Inventors
- 👤 Richard J. G. Dominguez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:24
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/65; B; B29; B29C; B29C33/00; B29C33/56; B29C33/60; B29C33/62; B29C33/64; B29C67/00; B29C67/24; B29C67/246; C08G18/08; C08G2120/00; Y; Y10; Y10S; Y10S264/00; Y10S264/83
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
99 words
A method for making a reaction injection molded elastomer which will release from its mold with reduced frequency of application of external mold release agents comprising injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream a high molecular weight polyhydric polyether, a low molecular weight active hydrogen containing compound of at least two functionality and an internal mold release agent, and in the second stream an aromatic polyisocyanate and tin catalyst in an amount equal to 100% of the tin catalyst present in the formulation.
Claim 2
Independent Claim
99 words
A method for making a reaction injection molded elastomer which will release from its mold with reduced frequency of application of external mold release agents comprising injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream a high molecular weight polyhydric polyether, a low molecular weight active hydrogen containing compound of at least two functionality and an internal mold release agent, and in the second stream an aromatic polyisocyanate and tin catalyst in an amount equal to 100% of the tin catalyst present in the formulation.
Claim 3
Dependent Claim
28 words
A method as in claim 1 wherein the low molecular weight active hydrogen containing compound is an amine terminated polyether having a functionality of about 2 to 6.
Claim 4
Dependent Claim
20 words
A method as in claim 2 wherein the functionality of the amine terminated polyethers is from about 2 to 3.
Claim 5
Dependent Claim
18 words
A method as in claim 1 wherein the polyhydric polyether has a molecular weight greater than about 2,500.
Claim 6
Dependent Claim
20 words
A method as in claim 1 where the internal mold release agent comprises a dimethyl siloxane with organic acid groups.
Claim 7
Independent Claim
100 words
A method for making a RIM elastomer which will release from its mold with reduced frequency of application of external mold release agents comprising injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream a polyhydric polyether of above about 5000 molecular weight, a low molecular weight active hydrogen containing compound of at least two functionality and an internal mold release agent, and in the second stream an aromatic polyisocyanate and tin catalyst in an amount equal to 100% of the tin catalyst present in the formulation.
Claim 8
Independent Claim
100 words
A method for making a RIM elastomer which will release from its mold with reduced frequency of application of external mold release agents comprising injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream a polyhydric polyether of above about 5000 molecular weight, a low molecular weight active hydrogen containing compound of at least two functionality and an internal mold release agent, and in the second stream an aromatic polyisocyanate and tin catalyst in an amount equal to 100% of the tin catalyst present in the formulation.
Claim 9
Dependent Claim
28 words
A method as in claim 6 wherein the low molecular weight active hydrogen containing compound is an amine terminated polyether having a functionality of about 2 to 6.
Claim 10
Dependent Claim
20 words
A method as in claim 7 wherein the functionality of the amine terminated polyethers is from about 2 to 3.
Claim 11
Dependent Claim
20 words
A method as in claim 6 where the internal mold release agent comprises a dimethyl siloxane with organic acid groups.
References Cited (Backward Citations)
US3523918A
Cited
US3838076A
Cited
US4130698A
Cited
US4218543A
Cited
US4272618A
Cited
US4254069A
Cited
US4246363A
Cited
US4281096A
Cited
US4314963A
Cited
US4269945A
Cited
US4273885A
Cited
US4314962A
Cited
US4374210A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-12 | 1987-06-13 | 1987-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-12 | 1991-06-13 | 1991-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-12 | 1995-06-13 | 1995-12-13 | $7700.00 | Window Closed / Lapsed |