Foams containing treated titanium dioxide and processes for making
AssigneeThe Dow Chemical Company
InventorBharat I. Chaudhary
Life of this patent
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Abstract
Disclosed is a closed-cell polymer foam comprising a quantity of titanium dioxidce particulates sufficient to reduce the thermal conductivity of the foam to less than that of a corresponding foam without the titanium dioxide particulates. The titanium dioxide particulates have a wetting aggent applied to a substantial portion of their surfaces. Further disclosed are processes for making the foams.
Claims24
A process for making an extruded thermoplastic polymer foam, comprising:
- a) heating a thermoplastic polymer material to form a melt polymer material;
- b) incorporating into the melt polymer material about 1 to about 20 weight percent of titanium dioxide particulates based upon the weight of the polymer wherein the particulates have a wetting agent applied to a substantial portion of their surfaces;
- c) further incorporating into the melt polymer material at an elevated pressure a blowing agent to form a foamable gel;
- d) cooling the foamable gel to an optimum foaming temperature;
- and
- e) extruding the foamable gel through a die to a region of lower pressure to form the foam.
A process for making a thermoset polymer foam, comprising:
- a) providing a first thermoset monomer;
- b) providing a second thermoset monomer the same or different than the first monomer and polymerizable with the first monomer;
- c) incorporating into either or both the first and second monomers about 1 to about 20 weight percent of treated titanium dioxide particulates based upon the weight of the polymer wherein the particulates have a wetting agent applied to a substantial portion of their surfaces;
- d) incorporating into either or both the first and second monomers a blowing agent;
- and
- e) mixing the first and second monomers under polymerizing conditions to form the thermoset polymer foam.
A process for making expandable thermoplastic foam beads, comprising:
- a) providing a first thermoplastic monomer;
- b) providing a second thermoplastic monomer the same or different than the first monomer and polymerizable with the first monomer;
- c) polymerizing the first and second monomers to form thermoplastic particles;
- d) incorporating during polymerization about 1 to about 20 weight percent of treated titanium dioxide particulates based upon the weight of the polymer wherein the particulates have a wetting agent applied to a substantial portion of their surfaces;
- e) incorporating a blowing agent into the thermoplastic particles during or after polymerization;
- and
- f) cooling the thermoplastic particles to form the expandable foam beads.
A process for making expandable thermoplastic foam beads, comprising:
- a) heating a thermoplastic polymer material to form a melt polymer material;
- b) incorporating into the melt polymer material about 1 to about 20 weight percent of treated titanium dioxide particulates based upon the weight of the polymer wherein the particulates have a wetting agent applied to a substantial portion of their surfaces;
- c) further incorporating into the melt polymer material at an elevated temperature a blowing agent to form a foamable gel;
- d) cooling the foamable gel to form an essentially continuous expandable thermoplastic strand;
- and
- e) pelletizing the expandable thermoplastic strand to form expandable thermoplastic foam beads.
Dependencies are inferred from the claim text.