US4143099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing a thermoplastic elastomeric blend of monoolefin copolymer rubber and polyolefin resin
Assignee: Uniroyal Chemical Co Inc
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Filing: 1976-05-10
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Granted: 1979-03-06
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Expires: 1996-05-10
Abstract
Abstract A method of preparing a thermoplastic elastomeric blend comprising mixing from 90 to 10 parts by weight of monoolefin copolymer rubber with correspondingly from 10 to 90 parts by weight of polyolefin resin having tertiary hydrogen and a free radical generating curing agent therefor, masticating and shearing the mixture to produce a semi-cure of the rubber, completing the semi-cure before the onset of melting of the polyolefin resin, and ensuring that once the polyolefin has melted the level of free radicals remaining in the mixture is not sufficient to cause substantial degradation of the polyolefin.
Inventors
- 👤 David J. Duncan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:48
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/24; C08K; C08K3/00; C08K3/18; C08K3/20; C08K3/22; C08K5/00; C08K5/04; C08K5/10; C08K5/14; C08L; C08L23/00; C08L23/02; C08L23/10; C08L23/16; C08J2323/00; C08J2323/02; C08L2312/00; C08L2666/00; C08L2666/02; C08L2666/04
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
186 words
A method of preparing a thermoplastic elastomeric blend comprising mixing from 75 to 10 parts by weight of monoolefin copolymer rubber with correspondingly from 25 to 90 parts by weight of polyolefin resin having tertiary hydrogen and a free radical generating peroxide curing agent therefor having a ten hour half-life temperature of from not less than 50° C. to less than 100° C., the amount of the active constituent of the curing agent in the blend not exceeding 1 part by weight per 100 parts of said rubber and resin together, masticating and shearing the mixture at an elevated temperature sufficient to produce a semi-cure of the rubber but below the temperature of melting of the polyolefin resin, and completing the said semi-cure before the onset of melting of the polyolefin resin thereby ensuring that once the polyolefin has melted the level of free radicals remaining in the mixture is not sufficient to cause substantial degradation of the polyolefin as evidenced by stickiness, the final temperature reached by the mixture after completing the said semi-cure being sufficient to melt the resin and form a uniform blend.
Claim 2
Independent Claim
186 words
A method of preparing a thermoplastic elastomeric blend comprising mixing from 75 to 10 parts by weight of monoolefin copolymer rubber with correspondingly from 25 to 90 parts by weight of polyolefin resin having tertiary hydrogen and a free radical generating peroxide curing agent therefor having a ten hour half-life temperature of from not less than 50° C. to less than 100° C., the amount of the active constituent of the curing agent in the blend not exceeding 1 part by weight per 100 parts of said rubber and resin together, masticating and shearing the mixture at an elevated temperature sufficient to produce a semi-cure of the rubber but below the temperature of melting of the polyolefin resin, and completing the said semi-cure before the onset of melting of the polyolefin resin thereby ensuring that once the polyolefin has melted the level of free radicals remaining in the mixture is not sufficient to cause substantial degradation of the polyolefin as evidenced by stickiness, the final temperature reached by the mixture after completing the said semi-cure being sufficient to melt the resin and form a uniform blend.
Claim 3
Dependent Claim
31 words
A method according to claim 1 in which the monoolefin copolymer rubber is an essentially amorphous, random, elastomeric copolymer of at least two monoolefins, and optionally, at least one copolymerisable polyene.
Claim 4
Dependent Claim
16 words
A method according to claim 2 in which the monoolefin copolymer rubber is an ethylene/propylene copolymer.
Claim 5
Dependent Claim
22 words
A method according to claim 2 in which the monoolefin copolymer rubber is a terpolymer of ethylene propylene and a copolymerisable diene.
Claim 6
Dependent Claim
22 words
A method according to claim 4 in which the copolymerisable diene is selected from the group consisting of 1,4-hexadiene, dicyclopentadiene and 5-ethylidene-2-norbornene.
Claim 7
Dependent Claim
13 words
A method according to claim 4 in which the copolymerisable diene is 1,4-hexadiene.
Claim 8
Dependent Claim
13 words
A method according to claim 4 in which the copolymerisable diene is dicyclopentadiene.
Claim 9
Dependent Claim
13 words
A method according to claim 4 in which the copolymerisable diene is 5-ethylidene-2-norbornene.
Claim 10
Dependent Claim
13 words
A method according to claim 1 in which the polyolefin resin is polypropylene.
Claim 11
Dependent Claim
37 words
A method according to claim 1 in which the curing agent is selected so that during masticating and shearing of the blend the curing agent has completed three half-lives by the onset of melting of the polypropylene.
Claim 12
Dependent Claim
22 words
A method according to claim 1 in which the curing agent has a one hour half-life temperature of less than 120° C.
Claim 13
Dependent Claim
14 words
A method according to claim 1 in which the curing agent is benzoyl peroxide.
Claim 14
Dependent Claim
23 words
A method according to claim 1 in which the curing agent is selected from the group comprising 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, lauroyl peroxide and t-butyl peroctoate.
Claim 15
Dependent Claim
36 words
A method according to claim 1 in which the amount of the active constituent of the curing agent in the blend does not exceed 0.2 part by weight per 100 parts of rubber and resin together.
Claim 16
Dependent Claim
52 words
A method according to claim 1 in which included in the mixture is an activating agent for the curing agent selected from the group consisting of amine activating agents and mercaptan activating agents, effective to cause the curing agent to produce free radicals at a temperature lower than its normal activation temperature.
Claim 17
Dependent Claim
33 words
A method according to claim 1 in which a scavenging agent is added to the mixture after the semi-cure of the rubber is complete and before the onset of melting of the resin.
Claim 18
Dependent Claim
19 words
A method according to claim 16 in which the scavenging agent is a stabiliser for the resultant semi-cured blend.
Claim 19
Dependent Claim
21 words
A method according to claim 17 in which the stabiliser is a mixture of dilaurylthio dipropionate and tetrakis (methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenol) propionate) methane.
References Cited (Backward Citations)
US3806558A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-05 | 1982-09-04 | 1983-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-05 | 1986-09-04 | 1987-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-05 | 1990-09-04 | 1991-03-06 | $7700.00 | Window Closed / Lapsed |