US4035322A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing curable pellets of polyethylene
Assignee: Southwire Co LLC
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Filing: 1975-04-10
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Granted: 1977-07-12
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Expires: 1995-04-10
Abstract
Abstract The present invention relates to a method for preparing curable pellets of polyethylene and copolymers thereof for subsequent use in an extrusion coating process by mixing polyethylene pellets with a liquid curing agent at a temperature below the decomposition temperature of the curing agent and below the softening point of polyethylene and copolymers thereof.
Inventors
- 👤 Stanley L. Tate
- 👤 Bobby A. Rowland
- 👤 Herbert M. Jacobs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:02
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/20; C08J3/201; B; B29; B29B; B29B7/00; B29B7/80; B29B7/88; B29B7/90; B29B7/94; B29B7/945; B29B9/00; B29B9/02; B29B9/06; B29B9/065; B29B9/16; C08J3/203; B29B2009/161; B29B2009/163; B29K; B29K2023/00; B29K2101/00; B29K2101/10; C08J2323/00; C08J2323/02; C08J2323/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
118 words
A method of preparing curable pellets of polyethylene and copolymers of polyethylene comprising the steps of: (a) fusing polymers such as polyethylene and copolymers thereof with fillers, lubricants and antitoxidants in a plasticating means until said fillers, lubricants and antioxidants are evenly dispersed throughout the polymers; (b) processing the final polymer, filler, lubricant, antioxidant mixture into pellets; (c) drying said pellets; (d) contacting and mixing said pellets with a stochiometric amount of a curing agent in an air fluid bed at a temperature below the softening point of said pellets and below the decomposition temperature of said curing agent with a continuous flow of turbulent air whereby said curing agent is coated upon and absorbed into said pellets.
Claim 2
Independent Claim
118 words
A method of preparing curable pellets of polyethylene and copolymers of polyethylene comprising the steps of: (a) fusing polymers such as polyethylene and copolymers thereof with fillers, lubricants and antitoxidants in a plasticating means until said fillers, lubricants and antioxidants are evenly dispersed throughout the polymers; (b) processing the final polymer, filler, lubricant, antioxidant mixture into pellets; (c) drying said pellets; (d) contacting and mixing said pellets with a stochiometric amount of a curing agent in an air fluid bed at a temperature below the softening point of said pellets and below the decomposition temperature of said curing agent with a continuous flow of turbulent air whereby said curing agent is coated upon and absorbed into said pellets.
Claim 3
Dependent Claim
34 words
The method of claim 1 further including the step of cooling the dried pellets of step (c) to a temperature of about 50° C. prior to contacting said dried pellets with said curing agent.
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein step (d) comprises blowing turbulent air through said pellets for from about four to about nine hours.
Claim 5
Dependent Claim
30 words
The method of claim 1 further including the step of cooling said pellets coated with curing agent to a temperature of no more than 25° C. before storing said pellets.
Claim 6
Dependent Claim
68 words
The method of claim 1 further including heating the dried pellets to a temperature of from about 45° C. to about 75° C., spraying said pellets with from about 0.01 to about 10.0 percent by weight of an organic peroxide curing agent selected from a group consisting of dicumylperoxide and α,α-bis(t-butylperoxy)-diiopropyl benzene and simultaneously subjecting the mixture of pellets and organic peroxide to violent agitation with turbulent air.
Claim 7
Dependent Claim
35 words
The method of claim 1 wherein said pellets consist essentially of about 69.82 percent polyethylene, about 1.52 percent α,α-bis(t-butylperoxy)-diisopropyl benzene, about 0.345 percent polymerized-1,2,-dihydro-2,2,4-trimethylquinoline, about 27.970 percent carbon black and about 0.345 percent zinc stearate.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein said pellets consist essentially of about 83.264 percent polyethylene, about 1.748 percent α,α-bis(t-butylperoxy)-diisopropyl benzene, about 0.416 percent 1,2-dihydro-2,2,4-trimethylquinoline, about 14.156 percent carbon black and about 0.416 percent zinc stearate.
Claim 9
Dependent Claim
49 words
The method of claim 1 wherein said pellets consist essentially of about 65.42 percent polyethylene, about 8.51 percent chlorinated polyethylene, about 5.23 percent antimony trioxide, about 18.45 percent clay, about 0.16 percent polymerized-1,2,-dihydro-2,2,4-trimethyl quinoline, about 0.26 lead oxide, about 0.33 percent zinc stearate and about 1.64 percent α,α-bis(t-butylperoxy)-diisopropyl benzene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |