US4276247A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cyclic peroxyketal cross-linking/blowing agents for polyethylene
Assignee: Argus Chemical Corp
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Filing: 1980-02-19
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Granted: 1981-06-30
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Expires: 2000-02-19
Abstract
Abstract Novel processes and compositions are provided for the preparation of foamed, crosslinked polyethylene utilizing cyclic peroxyketal crosslinking/blowing agents. The novel compositions include esters of thiodipropionic acid as activators.
Inventors
- 👤 John R. Muenchow
- 👤 Ronald L. Pastorino
- 👤 Reidar Halle
- 👤 Roger N. Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:51
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/08; C08J9/02; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06; Y; Y10; Y10S; Y10S264/00; Y10S264/05; Y10S264/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
111 words
A method for making foamed, crosslinked polyethylene comprising: mixing polyethylene with about 0.10-10% by weight of a crosslinking/blowing agent of the formula: ##STR9## wherein each of R 2 , R 3 , R 4 and R 5 is selected from alkyl having from 1-4 carbon atoms; each of R and R 1 is selected from alkyl, hydroxy alkyl and alkyl carboxylate ester groups having up to about 10 carbon atoms, ##STR10## where n=0 to 3 and X is lower alkyl or alkoxy of up to about 5 carbon atoms; and heating said mixture to a temperature sufficient to crosslink and foam said polyethylene under conditions which permit expansion of the polyethylene.
Claim 2
Independent Claim
111 words
A method for making foamed, crosslinked polyethylene comprising: mixing polyethylene with about 0.10-10% by weight of a crosslinking/blowing agent of the formula: ##STR9## wherein each of R 2 , R 3 , R 4 and R 5 is selected from alkyl having from 1-4 carbon atoms; each of R and R 1 is selected from alkyl, hydroxy alkyl and alkyl carboxylate ester groups having up to about 10 carbon atoms, ##STR10## where n=0 to 3 and X is lower alkyl or alkoxy of up to about 5 carbon atoms; and heating said mixture to a temperature sufficient to crosslink and foam said polyethylene under conditions which permit expansion of the polyethylene.
Claim 3
Dependent Claim
59 words
A method according to claim 1 wherein said step of mixing further comprises mixing an antioxidant/promoter of the formula: ##STR11## wherein R 6 and R 7 are selected from the group consisting of alkyl, alkenyl, aryl, cycloalkyl, hydrocarbon radicals and combinations thereof and wherein at least one of R 6 and R 7 has at least 10 carbon atoms.
Claim 4
Dependent Claim
70 words
A method according to claim 2 wherein R, R 2 , R 3 , R 4 and R 5 are each methyl, R 1 is alkyl of 1-4 carbon atoms or an alkyl carboxylate ester group having up to 10 carbon atoms and R 6 and R 7 are each alkyl of from 10-25 carbon atoms, and said step of heating is at a temperature of at least 150° C.
Claim 5
Dependent Claim
14 words
A method according to claim 1 wherein said mixture is simultaneously crosslinked and foamed.
Claim 6
Dependent Claim
28 words
A method according to claim 1 wherein said heating is under pressure and further comprising the step of releasing said pressure whereby said foam is allowed to expand.
Claim 7
Independent Claim
123 words
A method for producing foamed, crosslinked polyethylene articles comprising the steps of mixing polyethylene with about 0.10-10% by weight of an organic peroxide of the formula: ##STR12## wherein each of R 2 , R 3 , R 4 and R 5 is selected from alkyl having from 1-4 carbon atoms; each of R and R 1 is selected from alkyl, hydroxy alkyl and alkyl carboxylate ester groups having up to about 10 carbon atoms, ##STR13## where n=0 to 3 and X is lower alkyl or alkoxy of up to about 5 carbon atoms; shaping said mixture comprising said polyethylene and said organic peroxide in a mold; heating said mixture to a temperature sufficient to foam and cross-link said polyethylene; and expanding said mixture.
Claim 8
Independent Claim
123 words
A method for producing foamed, crosslinked polyethylene articles comprising the steps of mixing polyethylene with about 0.10-10% by weight of an organic peroxide of the formula: ##STR12## wherein each of R 2 , R 3 , R 4 and R 5 is selected from alkyl having from 1-4 carbon atoms; each of R and R 1 is selected from alkyl, hydroxy alkyl and alkyl carboxylate ester groups having up to about 10 carbon atoms, ##STR13## where n=0 to 3 and X is lower alkyl or alkoxy of up to about 5 carbon atoms; shaping said mixture comprising said polyethylene and said organic peroxide in a mold; heating said mixture to a temperature sufficient to foam and cross-link said polyethylene; and expanding said mixture.
Claim 9
Dependent Claim
27 words
A method according to claim 6 wherein said mold has a volume greater than the volume of said mixture and said mixture expands into said mold volume.
Claim 10
Dependent Claim
28 words
A method according to claim 6 wherein said mixture substantially fills said mold; said heating is under pressure; and further comprising releasing said pressure whereby said mixture expands.
Claim 11
Dependent Claim
117 words
In a method for producing hollow, foamed polyethylene articles by rotationally molding a composition comprising polyethylene of a density greater than 0.925 g/cc blended with a blowing agent under conditions which permit expansion of said composition, the improvement comprising utilizing as said blowing agent an organic peroxide of the formula: ##STR14## wherein each of R 2 , R 3 , R 4 and R 5 is selected from alkyl having from 1-4 carbon atoms; each of R and R 1 is selected from alkyl, hydroxy alkyl and alkyl carboxylate ester groups having up to about 10 carbon atoms, ##STR15## where n=0 to 3 and X is lower alkyl or alkoxy of up to about 5 carbon atoms.
Claim 12
Dependent Claim
117 words
In a method for producing hollow, foamed polyethylene articles by rotationally molding a composition comprising polyethylene of a density greater than 0.925 g/cc blended with a blowing agent under conditions which permit expansion of said composition, the improvement comprising utilizing as said blowing agent an organic peroxide of the formula: ##STR14## wherein each of R 2 , R 3 , R 4 and R 5 is selected from alkyl having from 1-4 carbon atoms; each of R and R 1 is selected from alkyl, hydroxy alkyl and alkyl carboxylate ester groups having up to about 10 carbon atoms, ##STR15## where n=0 to 3 and X is lower alkyl or alkoxy of up to about 5 carbon atoms.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1984-06-29 | 1984-12-29 | 1985-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-29 | 1988-12-29 | 1989-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-29 | 1992-12-29 | 1993-06-30 | $7700.00 | Window Closed / Lapsed |