US4160072A
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US
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Foamable and crosslinkable polyethylene composition, process for its production, and process for producing crosslinked polyethylene foams using said composition
Assignee: Sekisui Chemical Co Ltd
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Filing: 1977-10-31
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Granted: 1979-07-03
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Expires: 1997-10-31
Abstract
Abstract A foamable and crosslinkable polyethylene composition comprising (A) MODIFIED POLYETHYLENE OBTAINED BY CHEMICALLY BONDING A SILANE COMPOUND CONTAINING AT LEAST ONE UNSATURATED GROUP TO POLYETHYLENE IN THE PRESENCE OF A RADICAL GENERATOR, (B) A ZINC SALT OF A HIGHER CARBOXYLIC ACID, AND (C) A HEAT-DECOMPOSABLE BLOWING AGENT, AND INGREDIENTS (A), (B) AND (C) HAVING BEEN MELT-KNEADED WITH ONE ANOTHER AT A TEMPERATURE LOWER THAN THE DECOMPOSITION TEMPERATURE OF THE HEAT-DECOMPOSABLE BLOWING AGENT.
Inventors
- 👤 Ken Shinkai
- 👤 Norio Chiba
- 👤 Yutaka Ozaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:16
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/10; C08F; C08F255/00; C08F255/02; C08J2323/00; C08J2323/26; Y; Y10; Y10S; Y10S521/00; Y10S521/909
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
72 words
A foamable and crosslinkable polyethylene composition conprising (a) modified polyethylene obtained by chemically bonding a silane compound containing at least one unsaturated group to polyethylene in the presence of a radical generator, (b) zinc stearate as the silanol condensation catalyst, and (c) azodicarbonamide as heat-decomposable blowing agent, said ingredients (a), (b) and (c) having been melt-kneaded with one another at a temperature lower than the decomposition temperature of the heat-decomposable blowing agent.
Claim 2
Dependent Claim
72 words
A foamable and crosslinkable polyethylene composition conprising (a) modified polyethylene obtained by chemically bonding a silane compound containing at least one unsaturated group to polyethylene in the presence of a radical generator, (b) zinc stearate as the silanol condensation catalyst, and (c) azodicarbonamide as heat-decomposable blowing agent, said ingredients (a), (b) and (c) having been melt-kneaded with one another at a temperature lower than the decomposition temperature of the heat-decomposable blowing agent.
Claim 3
Dependent Claim
17 words
The composition of claim 1 which has a gel content of not more than 40% by weight.
Claim 4
Dependent Claim
54 words
The composition of claim 1 comprising 100 parts by weight of polyethylene, 0.01 to 1.5 parts by weight of said radical generator, 0.5 to 10 parts by weight of the silane compound, 0.01 to 5 parts by weight of said zinc stearate, and 3 to 30 parts by weight of the heat-decomposable blowing agent.
Claim 5
Dependent Claim
21 words
The composition of claim 1 wherein said silane compound is a member selected from the group consisting of vinyltrimethoxysilane and vinyltriethoxysilane.
Claim 6
Dependent Claim
32 words
The composition of claim 1 wherein said radical generator has a half life of not more than 3 minutes at a temperature between the melting temperature of the polyethylene and 150° C.
Claim 7
Dependent Claim
34 words
The composition of claim 5 wherein said radical generator is a member selected from the group consisting of tert-butylperoxy pivalate, dicumyl peroxide, tert-butylperoxy 2-ethyl hexanoate, tert-butyl peracetate, tert-butylperoxy isobutyrate, benzoyl peroxide and lauroyl peroxide.
Claim 8
Dependent Claim
19 words
The composition of claim 1 wherein said heat-decomposable blowing agent has a decomposition temperature of 170° to 220° C.
Claim 9
Dependent Claim
27 words
The composition of claim 7 wherein said heat-decomposable blowing agent is a member selected from the group consisting of azodicarbonamide, dinitrosopentamethylene tetramine, benzenesulfonyl hydrazide and toluene-sulfonyl hydrazide.
Claim 10
Dependent Claim
12 words
The composition of claim 1 which further includes a chain transfer agent.
Claim 11
Dependent Claim
13 words
The composition of claim 9 wherein said chain transfer agent is dodecyl mercaptan.
Claim 12
Dependent Claim
28 words
The composition of claim 9 wherein the amount of said chain transfer agent is 0.01 to 0.5 part by weight per 100 parts by weight of the polyethylene.
Claim 13
Dependent Claim
102 words
The composition of claim 1 comprising 100 parts by weight of polyethylene, 0.1-1.0 parts by weight of said radical generator, 0.5-10 parts by weight of the silane compound, 0.1-3.0 parts by weight of said zinc stearate, and 10-20 parts by weight of the heat-decomposable blowing agent, said silane compound being a member selected from the group consisting of vinyltrimethoxysilane and vinyltriethoxysilane and said radical generator being a member selected from the group consisting of tert-butylperoxy pivalate, dicumyl peroxide, tert-butylperoxy 2-ethyl hexanoate, tert-butylperacetate, tert-butylperoxy isobutyrate, benzoyl peroxide and lauroyl peroxide, said composition having a gel content of not more than 20% by weight.
Claim 14
Dependent Claim
26 words
The composition of claim 11 wherein the amount of said chain transfer agent is 0.03-0.1 parts by weight per 100 parts by weight of the polyethylene.
Claim 15
Dependent Claim
91 words
A process for preparing crosslinked polyethylene foams, which comprises melt-kneading (a) modified polyethylene obtained by chemically bonding a silane compound containing at least one unsaturated group to polyethylene in the presence of a radical generator, (b) zinc stearate as the silanol condensation catalyst and (c) azodicarbonamide as a heat-decomposable blowing agent at a temperature below the decomposition temperature of the heat-decomposable blowing agent, shaping the kneaded mixture, and heating the shaped article to a temperature above the decomposition temperature of the heat-decomposable blowing agent to expand and crosslink the shaped article.
Claim 16
Dependent Claim
91 words
A process for preparing crosslinked polyethylene foams, which comprises melt-kneading (a) modified polyethylene obtained by chemically bonding a silane compound containing at least one unsaturated group to polyethylene in the presence of a radical generator, (b) zinc stearate as the silanol condensation catalyst and (c) azodicarbonamide as a heat-decomposable blowing agent at a temperature below the decomposition temperature of the heat-decomposable blowing agent, shaping the kneaded mixture, and heating the shaped article to a temperature above the decomposition temperature of the heat-decomposable blowing agent to expand and crosslink the shaped article.
Claim 17
Dependent Claim
10 words
Crosslinked polyethylene foams prepared by the process of claim 14.
Claim 18
Dependent Claim
19 words
The polyethylene foams of claim 15 which are in the form of a sheet, rod, cylinder, board or block.
Claim 19
Dependent Claim
66 words
A process for preparing a foamable and crosslinkable polyethylene composition, which comprises melt-kneading (a) modified polyethylene obtained by chemically bonding a silane compound containing at least one unsaturated group to polyethylene in the presence of a radical generator, (b) zinc stearate as the silanol condensation catalyst and (c) azodicarbonamide as heat-decomposable blowing agent at a temperature lower than the decomposition temperature of the heat-decomposable blowing agent.
Claim 20
Dependent Claim
66 words
A process for preparing a foamable and crosslinkable polyethylene composition, which comprises melt-kneading (a) modified polyethylene obtained by chemically bonding a silane compound containing at least one unsaturated group to polyethylene in the presence of a radical generator, (b) zinc stearate as the silanol condensation catalyst and (c) azodicarbonamide as heat-decomposable blowing agent at a temperature lower than the decomposition temperature of the heat-decomposable blowing agent.
Claim 21
Dependent Claim
21 words
The process of claim 17 wherein said silane compound is a member selected from the group consisting of vinyltrimethoxysilane and vinyltriethoxysilane.
Claim 22
Dependent Claim
27 words
The process of claim 17 wherein the amount of the silane compound is 0.5 to 10 parts by weight per 100 parts by weight of the polyethylene.
Claim 23
Dependent Claim
32 words
The process of claim 17 wherein said radical generator has a half life of not more than 3 minutes at a temperature between the melting temperature of the polyethylene and 150° C.
Claim 24
Dependent Claim
34 words
The process of claim 20 wherein said radical generator is a member selected from the group consisting of tert.-butylperoxy pivalate, dicumyl peroxide, tert.-butyl-peroxy 2-ethyl hexanoate, tert.-butyl peracetate, tert.-butylperoxy isobutyrate, benzoyl peroxide and lauroyl peroxide.
Claim 25
Dependent Claim
27 words
The process of claim 17 wherein the amount of the radical generator is 0.01 to 1.5 parts by weight per 100 parts by weight of the polyethylene.
Claim 26
Dependent Claim
27 words
The process of claim 17 wherein the amount of said zinc stearate is 0.01 to 5 parts by weight per 100 parts by weight of the polyethylene.
Claim 27
Dependent Claim
19 words
The process of claim 17 wherein said heat-decomposable blowing agent has a decomposition temperature of 170° to 220° C.
Claim 28
Dependent Claim
27 words
The process of claim 24 wherein said heat-decomposable blowing agent is a member selected from the group consisting of azodicarbonamide, dinitrosopentamethylene tetramine, benzenesulfonyl hydrazide and toluene-sulfonyl hydrazide.
Claim 29
Dependent Claim
28 words
The process of claim 17 wherein the amount of the heat-decomposable blowing agent is 3 to 30 parts by weight per 100 parts by weight of the polyethylene.
Claim 30
Dependent Claim
16 words
The process of claim 17 wherein a chain transfer agent is further kneaded into the mixture.
Claim 31
Dependent Claim
13 words
The process of claim 27 wherein the chain transfer agent is dodecyl mercaptan.
Claim 32
Dependent Claim
28 words
The process of claim 27 wherein the amount of the chain transfer agent is 0.01 to 0.05 part by weight per 100 parts by weight of the polyethylene.
Claim 33
Dependent Claim
16 words
The process of claim 17 wherein the melt-kneading is carried out by means of an extruder.
Claim 34
Dependent Claim
25 words
The process of claim 17 wherein components (a), (b) and (c) are melt-kneaded at a temperature in the range of from 110° to 150° C.
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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) | 1982-07-02 | 1983-01-01 | 1983-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-02 | 1987-01-01 | 1987-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-02 | 1991-01-01 | 1991-07-03 | $7700.00 | Window Closed / Lapsed |