Patent EP0377323A2 successfully refreshed from Google Patents.
EP0377323A2
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Closed cell microcellular foams and their method of manufacture
Assignee: Dow Chemical Co
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Filing: 1989-12-27
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Granted: —
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Expires: 2009-12-27
Abstract
Abstract Closed cell microcellular foam having cells with diameters of less than 10 mu m and preferably having a density is less than 0.1 gm/cm<3> are prepared from copolymers of alpha -olefin and alpha , beta -monoethylenically unsaturated carboxylic acid. The copolymer is permeated with a blowing agent and ammonia at a pressure of 1.4 to 20 MPag in the presence of an inert gas and subsequently is heated by electromagnetic radiation of 0.1 to 200 MHz.
Inventors
- 👤 Steve Pak-Wing Chum
- 👤 Louis C. Rubens
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 10:43
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; C08J9/14; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/08
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
127 words
A method for preparing a closed cell microcellular foam comprising the steps of: (a) permeating a copolymer of at least one α-olefin and at least one α,β-monoethylenically unsaturated carboxylic acid, by pressurizing using an inert gas in the presence of a blowing agent and ammonia for an incubation time sufficient to effect a substantial diffusion of the inert gas, the blowing agent and the ammonia throughout the copolymer, the pressurizing being sufficient to maintain a pressure from 1.4 MPag (200 psig) to 20 MPag (3,000 psig); and thereafter (b) heating the permeated copolymer in a field of electromagnetic radiation of from 0.1 megahertz (MHz) to 200 MHz to prepare a closed cell microcellular foam wherein the foam contains cells with a diameter of less than 10 µm..
Claim 2
Independent Claim
127 words
A method for preparing a closed cell microcellular foam comprising the steps of: (a) permeating a copolymer of at least one α-olefin and at least one α,β-monoethylenically unsaturated carboxylic acid, by pressurizing using an inert gas in the presence of a blowing agent and ammonia for an incubation time sufficient to effect a substantial diffusion of the inert gas, the blowing agent and the ammonia throughout the copolymer, the pressurizing being sufficient to maintain a pressure from 1.4 MPag (200 psig) to 20 MPag (3,000 psig); and thereafter (b) heating the permeated copolymer in a field of electromagnetic radiation of from 0.1 megahertz (MHz) to 200 MHz to prepare a closed cell microcellular foam wherein the foam contains cells with a diameter of less than 10 µm..
Claim 3
Dependent Claim
17 words
A method as claimed in Claim 1, wherein the blowing agent is selected from chlorofluorocarbons and chlorofluorohydrocarbons.
Claim 4
Dependent Claim
27 words
A method as claimed in Claim 1 or Claim 2, wherein the pressure of step (a) is from 1.4 MPag (200 psig) to 5.5 MPag (800 psig).
Claim 5
Independent Claim
17 words
A method as claimed in any one of the preceding claims, wherein the inert gas is nitrogen.
Claim 6
Independent Claim
32 words
A method as claimed in any one of the preceding claims, wherein the field of electromagnetic radiation of step (b) is radiowave radiation with a frequency from 6 MHz to 100 MHz.
Claim 7
Independent Claim
48 words
A method as claimed in any one of the preceding claims, wherein the copolymer comprises from 70 weight percent to 95 weight percent of an α-olefin and from 5 weight percent to 30 weight percent of an α,β-monoethylenically unsaturated carboxylic acid, based upon the weight of the copolymer.
Claim 8
Independent Claim
30 words
A method as claimed in any one of the preceding claims, wherein the α-olefin contains 3 to 8 carbons and the α,β-monoethylenically unsaturated carboxylic acid contains 3 to 8 carbons.
Claim 9
Dependent Claim
13 words
A method as claimed in Claim 7, wherein the copolymer is poly(ethylene/acrylic acid).
Claim 10
Independent Claim
18 words
A method as claimed in any one of the preceding claims, wherein the carboxylic acid is an ionomer.
Claim 11
Dependent Claim
20 words
A method as claimed in Claim 9, wherein the carboxylic acid is complexed with the cation of magnesium or lead.
Claim 12
Dependent Claim
22 words
A method as claimed in Claim 9 or Claim 10, further comprising the step of crosslinking of the copolymer of step (a).
Claim 13
Dependent Claim
33 words
A closed cell microcellular foam comprising a copolymer of at least one α-olefin and at least one α,β-monoethylenically unsaturated carboxylic acid wherein the foam has cells having diameters of less than 10 µm.
Claim 14
Dependent Claim
33 words
A closed cell microcellular foam comprising a copolymer of at least one α-olefin and at least one α,β-monoethylenically unsaturated carboxylic acid wherein the foam has cells having diameters of less than 10 µm.
Claim 15
Dependent Claim
24 words
A closed cell microcellular foam as claimed in Claim 12, wherein the copolymer is as defined in any one of Claims 6 to 11.
Claim 16
Dependent Claim
25 words
A closed cell microcellular foam as claimed in Claim 12 or Claim 13, wherein the cells have a diameter of 2 µm to 5 µm.
Claim 17
Dependent Claim
29 words
A closed cell microcellular foam as claimed in any one of Claims 12 to 14, wherein the density is from 0.01 g/cm³ (0.64 lb/ft³) to 0.1 g/cm³ (6.4 lb/ft³).
References Cited (Backward Citations)
No citation records indexed.
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