Biodegradable paper-based cup or package and production method
AssigneeInternational Paper Company
InventorsChristopher Cleveland, Tricia Reighard
Life of this patent
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Abstract
There is disclosed a biodegradable laminate suitable for use in shaped paper-based articles such as containers for liquid or solid, hot or cool, food products, comprising a paper-based substrate having first and second copolyester layers deposited onto at least one surface of the substrate, in the substantial absence of intervening polymer layers between the substrate surface and the copolyesters deposited on the substrate surface. A biodegradable shaped article formed from the laminate and a method for forming a biodegradable laminate are also disclosed.
Claims29
A biodegradable laminate, comprising a paper-based substrate having laminated thereto at least one layer of a first copolyester and at least one layer of a second copolyester, said layers being deposited onto at least one surface of said substrate, wherein a first layer is an inner layer providing adhesion to the paper-based substrate, and a second layer is an outer layer preventing chill roll sticking and blocking in the roll and providing greater thermal stability compared to said first layer.
A biodegradable paper-based shaped article comprising a paper-based substrate having at least two surfaces and a biodegradable laminate provided on at least one surface of said substrate, wherein said laminate has an inner layer of first copolyester laminated thereto, said first copolyester layer providing adhesion to the paper-based substrate, and an outer layer of second copolyester preventing chill roll sticking and blocking in the roll and providing greater thermal stability compared to said first layer, and wherein the copolyesters of said first and second layers are non-identical copolymerization products of benzene-1,4-dicarboxylic acid with an aliphatic dihydric alcohol and at least one reactant selected from the group consisting of an aliphatic dicarboxylic acid and a cyclic dihydric alcohol.
A method of forming a biodegradable paper-based shaped article, which comprises the following steps:
- a) providing a paper-based substrate having a basis weight in the range of 100-300 lb/3000 ft2 and at least one flat surface;
- b) applying to at least one flat surface of the substrate a laminate of at least one first copolyester and at least one second copolyester, the first copolyester and the second copolyester being non-identical;
- and
- c) shaping the article;
- wherein a layer of first copolyester is an inner layer providing adhesion to the paper-based substrate, and a layer of second copolyester is an outer layer preventing chill roll sticking and blocking in the roll and providing greater thermal stability compared to the inner layer, and wherein the first and second copolyesters are non-identical copolymerization products of benzene-1,4-dicarboxylic acid with an aliphatic dihydric alcohol and at least one reactant selected from the group consisting of an aliphatic dicarboxylic acid and a cyclic dihydric alcohol.
Dependencies are inferred from the claim text.