Patent US3051901A successfully refreshed from Google Patents.
Patent US4346205A successfully refreshed from Google Patents.
US4346205A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Energy absorbing elastomers and composites
Assignee: BTG International Ltd
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Filing: 1980-05-19
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Granted: 1982-08-24
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Expires: 2000-05-19
Abstract
Abstract A novel elastomer having a very low compression set and a very slow recovery from compression comprises a flexible polyurethane of essentially linear structure containing unsatisfied hydroxyl groups, and is the reaction product of substantially linear polyols having hydroxyl end groups and an average molecular weight in the range 600 to 1200, with an aromatic isocyanate in less than stoichiometric amount. This elastomer can be used as one layer of an energy-absorbing material, in combination with a more difficultly compressible layer comprising a tough flexible polymeric matrix having a plurality of rigid hollow bodies embedded therein.
Inventors
- 👤 Maurice A. F. Hiles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:38
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/48; C08G18/4825; B; B60; B60R; B60R19/00; B60R19/02; B60R19/18; B60R19/22; C08L; C08L75/00; C08L75/04; C08G2350/00; Y; Y10; Y10S; Y10S528/00; Y10S528/906; Y10T; Y10T428/00; Y10T428/23; Y10T428/233; Y10T428/249921; Y10T428/249953; Y10T428/249987; Y10T428/249991; Y10T428/31504; Y10T428/31551; Y10T428/31554; Y10T428/31573
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
74 words
An elastomer comprising a flexible polyurethane of essentially linear structure containing unsatisfied hydroxyl groups, and having a compression set less than 15%, an elongation at break of at least 500%, and a recovery which is delayed after compression by at least 0.7 sec, said elastomer comprising the reaction product of substantially linear polyols based on polyalkylene glycol and having an average molecular weight in the range of 600 to 1200, and an aromatic diisocyanate.
Claim 2
Dependent Claim
74 words
An elastomer comprising a flexible polyurethane of essentially linear structure containing unsatisfied hydroxyl groups, and having a compression set less than 15%, an elongation at break of at least 500%, and a recovery which is delayed after compression by at least 0.7 sec, said elastomer comprising the reaction product of substantially linear polyols based on polyalkylene glycol and having an average molecular weight in the range of 600 to 1200, and an aromatic diisocyanate.
Claim 3
Dependent Claim
17 words
An elastomer as claimed in claim 1 having a compression set at room temperature less than 5%.
Claim 4
Dependent Claim
19 words
An elastomer as claimed in claim 1 having a Shore (0 0) hardness in the range 0 to 50.
Claim 5
Dependent Claim
16 words
An elastomer as claimed in claim 3 having a hardness in the range 0 to 20.
Claim 6
Dependent Claim
16 words
An elastomer as claimed in claim 1, having a recovery delay of at least 2 secs.
Claim 7
Dependent Claim
13 words
An elastomer as claimed in claim 1, wherein the diisocyanate is 4,4'-diphenylmethane diisocyanate.
Claim 8
Dependent Claim
18 words
An elastomer as claimed in claim 1 containing 0.002 to 0.004 gram of unsatisfied OH groups per gram.
Claim 9
Dependent Claim
18 words
An elastomer as claimed in claim 7 containing 0.0023 to 0.0034 gram of unsatisfied OH groups per gram.
Claim 10
Dependent Claim
11 words
An elastomer as claimed in claim 1 containing an anti-tack agent.
Claim 11
Dependent Claim
14 words
An elastomer as claimed in claim 9 wherein said agent is a silicone polycarbinol.
Claim 12
Dependent Claim
15 words
An elastomer as claimed in claim 10 wherein said agent is a polypropylene oxide-siloxane copolymer.
Claim 13
Dependent Claim
21 words
An elastomer as claimed in claim 10 in which the proportion of said agent is not more than 2% by weight.
Claim 14
Independent Claim
79 words
A method of making a flexible polyurethane elastomer of essentially linear structure containing unsatisfied hydroxyl groups and having a compression set less than 15%, an elongation at break of at least 500%, and a recovery which is delayed after compression by at least 0.7 sec, which method comprises reacting substantially linear polyols based on polyalkylene glycol and having an average molecular weight in the range 600 to 1200 with an aromatic diisocyanate which is in less than stoichiometric amount.
Claim 15
Independent Claim
79 words
A method of making a flexible polyurethane elastomer of essentially linear structure containing unsatisfied hydroxyl groups and having a compression set less than 15%, an elongation at break of at least 500%, and a recovery which is delayed after compression by at least 0.7 sec, which method comprises reacting substantially linear polyols based on polyalkylene glycol and having an average molecular weight in the range 600 to 1200 with an aromatic diisocyanate which is in less than stoichiometric amount.
Claim 16
Dependent Claim
28 words
An elastomer as claimed in claim 1 wherein said substantially linear polyols based on polyalkylene glycol have an average molecular weight in the range of 700 to 900.
Claim 17
Dependent Claim
45 words
An elastomer as claimed in claim 1 wherein said substantially linear polyols based on polyalkylene glycol are a blend of a major amount of polyol having an average molecular weight above 1500 and a minor amount of polyol having an average molecular weight below 500.
Claim 18
Dependent Claim
49 words
An elastomer as claimed in claim 1 wherein said substantially linear polyols based on polyalkylene glycol are a blend of about 75 percent by weight of polyol having an average molecular weight above 1500 and about 25 percent by weight of polyol having an average molecular weight below 500.
Claim 19
Dependent Claim
28 words
A method as claimed in claim 13 wherein said substantially linear polyols based on polyalkylene glycol have an average molecular weight in the range of 700 to 900.
Claim 20
Dependent Claim
16 words
A method as claimed in claim 13 wherein the reaction is catalyzed by a tertiary amine.
Claim 21
Dependent Claim
24 words
A method as claimed in claim 13 further comprising admixing a silicone polycarbinol in an amount not exceeding 2% by weight of the polyol.
Claim 22
Dependent Claim
22 words
A method as claimed in claim 19 wherein the amount of silicone polycarbinol is 0.5 to 1% by weight of the polyol.
Claim 23
Dependent Claim
16 words
A method as claimed in claim 13 wherein the reaction is carried out under superatmospheric pressure.
Claim 24
Dependent Claim
18 words
A method as claimed in claim 21 wherein the pressure is in the range 50 to 150 p.s.i.
Claim 25
Dependent Claim
45 words
A method as claimed in claim 13 wherein said substantially linear polyols based on polyalkylene glycol are a blend of a major amount of polyol having an average molecular weight above 1500 and a minor amount of polyol having an average molecular weight below 500.
Claim 26
Dependent Claim
49 words
A method as claimed in claim 13 wherein said substantially linear polyols based on polyalkylene glycol are a blend of about 75 percent by weight of polyol having an average molecular weight above 1500 and about 25 percent by weight of polyol having an average molecular weight below 500.
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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) | 1985-08-23 | 1986-02-22 | 1986-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-23 | 1990-02-22 | 1990-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-23 | 1994-02-22 | 1994-08-24 | $7700.00 | Window Closed / Lapsed |