US4029729A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotational molding and compositions therefor
Assignee: Phillips Petroleum Co
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Filing: 1972-05-08
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Granted: 1977-06-14
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Expires: 1992-05-08
Abstract
Abstract Polymers of ethylene having a melt index of at least 10 are simultaneously rotationally molded and crosslinked by an acetylenic diperoxy compound to produce molded articles having high impact strength and stress cracking resistance.
Inventors
- 👤 Robert L. Rees
- 👤 Fay W. Bailey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:36
CPC Classifications
B; B29; B29C; B29C41/00; B29C41/003; C; C08; C08K; C08K5/00; C08K5/04; C08K5/14; B29C41/02; B29C41/04; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2105/00; B29K2105/24
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
162 words
A method for producing hollow articles which comprises: supplying to a mold a measured amount of a powdered thermoplastic moldable material comprising a solid polymer selected from the group consisting of ethylene homopolymers, copolymers of ethylene and at least one acrylic mono-1 olefin hydrocarbon having 3 to 8 carbon atoms per molecule formed from at least 75 weight percent ethylene, and mixtures thereof, having a melt index of at least about 10 having incorporated within the molding resin a crosslinking amount of an acetylenic diperoxy compound selected from the group consisting of hexynes having the formula ##STR4## octynes having the formula ##STR5## and octynes having the formula ##STR6## wherein R is selected from the group consisting of tertiary alkyl, alkyl carbonate, and benzoate; rotating the mold while heating it to fuse the thermoplastic powder; and cooling the mold to cause the hollow article to solidify whereby said article has high impact strength and environmental stress cracking resistance (ESCR) and smooth inner surface.
Claim 2
Independent Claim
162 words
A method for producing hollow articles which comprises: supplying to a mold a measured amount of a powdered thermoplastic moldable material comprising a solid polymer selected from the group consisting of ethylene homopolymers, copolymers of ethylene and at least one acrylic mono-1 olefin hydrocarbon having 3 to 8 carbon atoms per molecule formed from at least 75 weight percent ethylene, and mixtures thereof, having a melt index of at least about 10 having incorporated within the molding resin a crosslinking amount of an acetylenic diperoxy compound selected from the group consisting of hexynes having the formula ##STR4## octynes having the formula ##STR5## and octynes having the formula ##STR6## wherein R is selected from the group consisting of tertiary alkyl, alkyl carbonate, and benzoate; rotating the mold while heating it to fuse the thermoplastic powder; and cooling the mold to cause the hollow article to solidify whereby said article has high impact strength and environmental stress cracking resistance (ESCR) and smooth inner surface.
Claim 3
Dependent Claim
36 words
The method of claim 1 wherein said solid polymer has a density in the range of 0.920 - 0.970 and a molecular weight distribution not greater than about 7, and said diperoxy compound is a hexyne.
Claim 4
Dependent Claim
30 words
The method of claim 2 wherein said diperoxy compound is selected from the group consisting of 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3; 2,5-dimethyl-2,5-di(peroxybenzoate)hexyne-3; 2,5-dimethyl-2,5-di(peroxy-n-propylcarbonate)hexyne-3; 2,5-dimethyl-2,5-di(peroxy isobutyl carbonate)hexyne-3; 2,5-dimethyl-2,5-di(peroxy ethyl carbonate)hexyne-3; 2,5-dimethyl-2,5-di(alpha-cumyl peroxy)hexyne-3; 2,5-dimethyl-2,5-di(peroxy beta-chloroethyl carbonate)-hexyne-3.
Claim 5
Dependent Claim
11 words
The method of claim 3 wherein said diperoxy compound is 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3.
Claim 6
Dependent Claim
38 words
The method of claim 4 wherein said melt index is in the range of 10-200 and said diperoxy compound is present in an amount between 0.1 and 10 parts by weight per 100 parts by weight of polymer.
Claim 7
Dependent Claim
21 words
The method of claim 5 wherein said acyclic mono-1 olefin hydrocarbon having 3 to 8 carbon atoms per molecule is butene.
Claim 8
Dependent Claim
19 words
A method according to claim 1 wherein the mold is closed and is rotated around more than one axis.
Claim 9
Dependent Claim
28 words
The method according to claim 7 wherein said mold is closed and is rotated around two axes at right angles to distribute the powdered material throughout the mold.
Claim 10
Dependent Claim
21 words
A method according to claim 8 wherein said powder is ground to pass 30 mesh sieve number (U.S. Standard Sieve Series).
Claim 11
Dependent Claim
30 words
A method according to claim 8 wherein said ESCR is greater than 1000 hours (ASTM D-1693-66) and said impact strength is at least about 40 foot pounds (dart impact test).
Claim 12
Dependent Claim
31 words
A method according to claim 1 wherein said diperoxy compound is selected from the group consisting of 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3; 2,5-dimethyl-2,5-di(peroxybenzoate)hexyne-3; 2,5-dimethyl-2,5-di(peroxy-n-propylcarbonate)hexyne-3; 2,5-dimethyl-2,5-di(peroxy isobutyl carbonate)hexyne-3; 2,5-dimethyl-2,5-di(peroxy ethyl carbonate)hexyne-3; 2,5-dimethyl-2,5-di(alphacumyl peroxy)hexyne-3; 2,5-dimethyl-2,5-di(peroxy beta-chloroethyl carbonate)-hexyne-3.
Claim 13
Dependent Claim
12 words
A method according to claim 11 wherein said diperoxy compound is 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3.
Claim 14
Dependent Claim
53 words
A method according to claim 12 wherein said melt index is in the range of 10-200, said diperoxy compound is present in an amount between 0.1 and 10 parts by weight per 100 parts by weight of polymer and said powder is ground to pass 30 mesh sieve number (U.S. Standard Sieve Series).
Claim 15
Dependent Claim
20 words
A method according to claim 13 wherein said acyclic mono-1 olefin hydrocarbon having 3-8 carbon atoms per molecule is butene.
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) | 1980-06-13 | 1980-12-13 | 1981-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-13 | 1984-12-13 | 1985-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-13 | 1988-12-13 | 1989-06-14 | $7700.00 | Window Closed / Lapsed |