Biodegradable foamed product from a starch graft copolymer
AssigneeUni-Star Industries, Inc.
InventorDonald L. Fisk
Life of this patent
Estimating the term…
Abstract
The biodegradable foamed product is made from a starch graft copolymer with an add-on level of about 5 to about 60%.
Claims26
A biodegradable foamed product consisting essentially of an expanded starch craft copolymer having a closed cell structure, said starch graft copolymer prior to expansion being a granular starch onto which has been grafted a thermoplastic polymer selected from the group consisting of poly(methyl acrylate), poly(butyl acrylate), poly(styrene), poly(methyl methacrylate), and blends thereof wherein the thermoplastic polymer is present in an amount of about 5 to about 60 weight percent by weight of copolymer, said foamed product having a closed cell structure making said product suitable as a packaging material.
A composition suitable for extruding into a biodegradable foamed product, consisting essentially of:
- a starch graft copolymer made from a granular starch onto which has been grafted a thermoplastic polymer selected from the group consisting of poly(methyl acrylate), poly (butyl acrylate), poly(styrene), poly(methyl methacrylate) and blends thereof wherein the thermoplastic polymer is present in an amount of about 5 to about 60 weight percent by weight copolymer;
- and a chemical blowing agent in an amount of about 0.1 to about 1.5 weight percent of copolymer, said chemical blowing agent being compatible with the temperature used during extrusion, said temperature being about 100.degree. C. to about 250.degree. C.
A method for using a starch graft copolymer to make a foamed product comprising the steps of:
- (a) forming a composition consisting essentially of a starch graft copolymer and a blowing agent, said starch graft copolymer being a granular starch onto which has been grafted a thermoplastic polymer selected from the group consisting of poly(methyl acrylate), poly(butyl acrylate), poly(styrene), poly(methyl methacrylate) and blends thereof wherein the thermoplastic polymer is present in an amount of about 5 to about 60 weight percent by weight of copolymer;
- (b) heating the composition of starch graft copolymer and blowing agent to form a fluid mix and to form cells in said fluid mix;
- and
- (c) solidifying said fluid mix to form a solid foamed product.
A method for using a starch graft copolymer as a foamed product for absorbing hydrocarbons comprising the steps of:
- (a) forming a composition consisting essentially of a starch graft copolymer and a blowing agent, said starch graft copolymer being a granular starch onto which has been grafted a thermoplastic polymer selected from the group consisting of poly(methyl acrylate), poly(butyl acrylate), poly(styrene), poly(methyl methacrylate), and blends thereof wherein the thermoplastic polymer is present in an amount of about 5 to about 60 weight percent by weight of copolymer;
- (b) heating the composition of starch graft copolymer and blowing agent to form a fluid mix and to form cells in said fluid mix;
- and
- (c) solidifying said fluid mix to form a solid foamed product.
In a process for making a starch graft copolymer, wherein starch is reacted with a thermoplastic polymer, the improvement comprising using a granular prime starch and said thermoplastic polymer being selected from the group consisting of poly(methyl acrylate), poly(butyl acrylate), poly(styrene), poly(methyl methacrylate), and blends thereof, the thermoplastic polymer being present in an amount of about 5 to about 60 weight percent by weight of copolymer.
A biodegradable foamed product comprising a granular prime starch onto which has been grafted a thermoplastic polymer selected from the group consisting of poly(methyl acrylate), poly(butyl acrylate), poly(styrene), poly(methyl methacrylate), and blends thereof wherein the thermoplastic polymer is present in an amount of about 5 to about 60 weight percent by weight of copolymer, said foamed product having a closed cell structure making said product suitable as a packaging material.
A method for using a starch graft copolymer to make a foamed product comprising the steps of:
- (a) forming a composition comprising a starch graft copolymer and a blowing agent, said starch graft copolymer being made from a prime starch and a thermoplastic polymer selected from the group consisting of poly(methyl acrylate), poly(butyl acrylate, poly(styrene), poly(methyl methacrylate), and blends thereof, the thermoplastic polymer being present in an amount of about 5 to about 60 weight percent by weight of copolymer;
- (b) heating the composition of starch graft copolymer and blowing agent to form a fluid mix and to form cells in said fluid mix;
- and
- (c) solidifying said fluid mix to form a solid foamed product.
Dependencies are inferred from the claim text.