Styrene-carboxylic acid copolymer foam

Patent metadata

Field	Value
Publication number	US-2016237233-A1
Application number	US-201415023742-A
Country	US
Kind code	A1
Filing date	Oct 29, 2014
Priority date	Nov 11, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

Prepare a polymer foam by expanding a foamable polymer composition of a copolymer component and a blowing agent where the copolymer component accounts for more than 50 weight-percent of the total polymer weight in the foamable polymer composition and is one or more than one styrene-carboxylic acid copolymer having an acid number of 20 or higher while the blowing agent comprises a fluorinated blowing agent, less than 70 weight-percent of which is 1,1,2,2-tetrafluoroethane and less than five weight-percent is carbon dioxide and C3-C5 hydrocarbons make up less than 30 mole-percent of the blowing agent; expand the foamable polymer composition into a polymer foam having an average cell size of less than 0.5 millimeters where the copolymer composition is a continuous phase in the polymer foam.

First claim

1 . A process for preparing polymer foam, the process comprising expanding a foamable polymer composition into a polymer foam wherein the foamable polymer composition comprises a copolymer component and a blowing agent, the process further characterized by:
a. the copolymer component consisting of one or more than one styrene-carboxylic acid copolymer; b. more than 50 weight-percent of the total polymer weight in the foamable polymer composition being the copolymer component; c. the acid number of the copolymer component being 20 or higher; d. the blowing agent consisting of at least one fluorinated blowing agent and, optionally, one or more than one additional blowing agent selected from a group consisting of carbon dioxide, water, aliphatic and cyclic hydrocarbons having from one to nine carbons, aliphatic alcohols having from one to five carbons, acetone, 2-butanone, acetaldehyde, dimethyl ether, diethyl ether, methyl ethyl ether, methyl formate, methyl acetate, and ethyl acetate; wherein less than 70 weight-percent of the total fluorinated blowing agent is 1,1,2,2-tetrafluoroethane; e. the blowing agent comprising less than five weight-percent carbon dioxide based on total blowing agent weight and less than 30 mole-percent hydrocarbons having from three to five carbons based on total moles of blowing agent; and f. the foamable polymer composition expanding into a polymer foam having an average cell size of less than 0.5 millimeters as determined by ASTM D3576 and wherein the copolymer composition forms a continuous phase in the resulting polymer foam.

2 . The process of claim 1 , further characterized by the blowing agent comprising a fluorinated blowing agent selected from HFC-152a, HFC-134a and HFO-1234ze.

3 . The process of claim 1 , further characterized by the copolymer being at least 90 weight-percent of the total weight of polymers in the foamable polymer composition and resulting polymer foam.

4 . The process of claim 1 , further characterized by the foamable polymer composition expanding into a polymeric foam having an open cell content of less than 20 percent as measured according to ASTM D6226.

5 . The process of claim 1 , further characterized by the carboxylic acid being selected from a group consisting of acrylic acid and methacrylic acid.

6 . The process of claim 1 , further characterized by the acid number of the copolymer component being 250 or less.

7 . The process of claim 1 , further characterized by the foamable polymer composition and resulting foam being free of propylene carbonate, ethylene carbonate and butylene carbonate.

8 . The process of claim 1 , further characterized by the process being a continuous extrusion foam process.

9 . The process of claim 1 , further characterized by the foamable polymer composition being free of styrenic polymers other than the copolymer component.

Assignees

• Dow Global Technologies Llc

Inventors

• Hood Lawrence S
• Costeux Stéphane
• Matteucci Scott T

Classifications

• C08J2203/162

  Halogenated unsaturated hydrocarbons, e.g. H2C=CF2 · CPC title

• C08J9/146 Primary

  only fluorine as halogen atoms · CPC title

• C08L25/08

  Copolymers of styrene (C08L29/08, C08L35/06, C08L55/02 take precedence) · CPC title

• C08J2325/08

  Copolymers of styrene (C08J2329/08, C08J2335/06, C08J2355/02 take precedence) · CPC title

• F16L59/028

  Compositions for or methods of fixing a thermally insulating material · CPC title