US4442233A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the manufacture of cross-linked and optionally foamed polypropylene
Assignee: Carl Freudenberg KG
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Filing: 1982-06-17
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Granted: 1984-04-10
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Expires: 2002-06-17
Abstract
Abstract Disclosed herein is a process for producing cross-linked polypropylene by subjecting a homogenous mixture of a polypropylene with from about 2 to about 20 weight percent, based upon the weight of the polypropylene, of polybutadiene with a molecular weight of from about 500 to about 10,000 to conditions sufficient to effect cross-linking, for example, through the use of cross-linking agents and/or irradiation. In addition, the process disclosed herein may be utilized to produce cross-linked and foamed polypropylenes.
Inventors
- 👤 Ernst Lohmar
- 👤 Wolffried Wenneis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:35
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08K; C08K5/00; C08K5/04; C08K5/14; C08L; C08L23/00; C08L23/02; C08L23/10; C08L23/12; C08J2323/00; C08J2323/02; C08J2323/10; C08J2323/12; C08J2409/00; C08L2312/00; C08L2312/06; C08L9/00
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
95 words
In a method for producing cross-linked crystalline high pressure or low pressure polypropylene by subjecting said polypropylene to high energy radiation and/or heating a mixture of said polypropylene with a peroxide cross-linking agent, the improvement comprising mixing said polypropylene with from about 2 to about 20 weight percent, based upon the weight of said polypropylene of, a normally liquid polybutadiene, and a foaming agent compounding said mixture at a temperature of about 160° C. to about 180° C.; and thereafter subjecting said compounded mixture to conditions sufficient to cross-link said polypropylene and foam said mixture.
Claim 2
Dependent Claim
95 words
In a method for producing cross-linked crystalline high pressure or low pressure polypropylene by subjecting said polypropylene to high energy radiation and/or heating a mixture of said polypropylene with a peroxide cross-linking agent, the improvement comprising mixing said polypropylene with from about 2 to about 20 weight percent, based upon the weight of said polypropylene of, a normally liquid polybutadiene, and a foaming agent compounding said mixture at a temperature of about 160° C. to about 180° C.; and thereafter subjecting said compounded mixture to conditions sufficient to cross-link said polypropylene and foam said mixture.
Claim 3
Dependent Claim
24 words
A method according to claim 1 wherein the amount of polybutadiene is from about 5 to about 10 weight percent based upon said polypropylene.
Claim 4
Dependent Claim
18 words
A method according to claim 1 wherein said polybutadiene has a 1,2-vinylpolybutadiene content of at least 35 percent.
Claim 5
Dependent Claim
21 words
A method according to claim 1 wherein said polybutadiene has a 1,2-vinylpolybutadiene content of from about 85 to about 90 percent.
Claim 6
Dependent Claim
27 words
A method according to claim 1, wherein cross-linking is effected by irradiation of said mixture at a dose rate of from about 2 to about 20 Mrad.
Claim 7
Dependent Claim
17 words
A method according to claim 5, wherein said dose is from about 6 to about 10 Mrad.
Claim 8
Dependent Claim
40 words
A method according to claim 1 wherein cross-linking is effected by admixing said mixture of polypropylene and polybutadiene with an organic peroxide cross-linking agent and heating the resulting mixture at a temperature greater than the decomposition temperature of said peroxide.
Claim 9
Dependent Claim
26 words
A method according to claim 7 wherein polypropylene, polybutadiene and organic cross-linking agent are mixed at a temperature below the decomposition temperature of the cross-linking agent.
Claim 10
Dependent Claim
37 words
A method according to claim 1 wherein polypropylene, polybutadiene and a foaming agent are mixed at a temperature below the decomposition of the foaming agent, thereafter subjecting the resulting mixture to conditions sufficient to cross-link said polypropylene.
Claim 11
Dependent Claim
24 words
A method according to claim 9 wherein the amount of polybutadiene is from about 5 to about 10 weight percent based upon said polypropylene.
Claim 12
Dependent Claim
18 words
A method according to claim 9 wherein said polybutadiene has a 1,2-vinylpolybutadiene content of at least 35 percent.
Claim 13
Dependent Claim
21 words
A method according to claim 9 wherein said polybutadiene has a 1,2-vinylpolybutadiene content of from about 85 to about 90 percent.
Claim 14
Dependent Claim
27 words
A method according to claim 9 wherein cross-linking is effected by irradiation of said mixture at a dose rate of from about 2 to about 20 Mrad.
Claim 15
Dependent Claim
17 words
A method according to claim 13, wherein said dose is from about 6 to about 10 Mrad.
Claim 16
Dependent Claim
41 words
A method according to claim 9 wherein cross-linking is effected by admixing said mixture of polypropylene and polybutadiene with an organic peroxide polypropylene cross-linking agent and heating the resulting mixture at a temperature greater than the decomposition temperature of said peroxide.
Claim 17
Dependent Claim
34 words
A method according to claim 7 wherein polypropylene, polybutadiene, an organic cross-linking agent and a foaming agent are mixed at a temperature below the decomposition temperatures of the cross-linking agent and the foaming agent.
Claim 18
Dependent Claim
22 words
A method according to claim 16, wherein the decomposition temperature of the foaming agent is higher than that of the cross-linking agent.
Claim 19
Dependent Claim
13 words
A method according to claim 7 wherein said mixture is compounded by extrusion.
Claim 20
Dependent Claim
21 words
A method according to claim 1 wherein said mixture of said polypropylene, polybutadiene and organic cross-linking agent is compounded by extrusion.
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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) | 1987-04-10 | 1987-10-10 | 1988-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-10 | 1991-10-10 | 1992-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-10 | 1995-10-10 | 1996-04-10 | $7700.00 | Window Closed / Lapsed |