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US 5,665,474 AGranted
Paper having a melt-stable lactide polymer coating and process for manufacture thereof
AssigneeCargill, Incorporated
InventorsPatrick Richard Gruber, Jeffrey John Kolstad, Christopher M. Ryan, Eric Stanley Hall, Robin Sue Eichen Conn
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Abstract
A lactide polymer coating resulting in a strong, repulpable, high gloss, paper coating. The lactide polymer comprises a plurality of poly(lactide) polymer chains, residual lactide in concentration of less than about 5 percent and water in concentration of less than about 2000 parts-per-million. A process for coating paper with the lactide polymer composition is also disclosed.
Claims26
A coated paper product comprising:
- (a) a paper substrate having a first surface;
- and
- (b) a polymer coating on said paper substrate first surface;
- said polymer coating comprising a melt stable polymer composition formed from at least:
- meso-lactide;
- lactide reactant;
- and, epoxidized oil;
- (i) said polymer composition having a number average molecular weight of from about 10,000 to about 200,000;
- (ii) said polymer composition having a lactide monomer concentration of less than about 5% by weight;
- and
- (iii) said lactide reactant being selected from the group consisting of L-lactide, D-lactide and mixtures thereof;
- (c) said polymer composition being formed from a reaction mixture comprising about 3% to about 50% by weight meso-lactide, based on the total weight of meso-lactide and lactide reactant in the reaction mixture;
- and
- (d) said polymer composition being a polymeric material in a form such that, when isolated and devolatilized, and before incorporation into said polymer coating, it will form less than 1% by weight lactide, upon heating at 180.degree. C. for 1 hour.
11 more elements
A coated paper product comprising:
- (a) a paper substrate having a first surface;
- and
- (b) a biodegradable polymer coating on said paper substrate first surface;
- said biodegradable polymer coating comprising a polymer composition comprising the polymer forming reaction product of at least:
- meso-lactide and L-lactide;
- (i) said polymer composition having a number average molecular weight of 10,000 to 200,000;
- (ii) said polymer composition having a lactide monomer concentration of less than about 5% by weight;
- and,
- (iii) said polymer composition being formed from a reaction mixture comprising about 3% to about 50% by weight meso-lactide, based on the total weight of meso-lactide, L-lactide and, if present, D-lactide.
6 more elements
A process for preparing coated paper;
- said process including the steps of:
- (a) melt processing a melt stable polymer composition formed from:
- meso-lactide;
- lactide reactant;
- and epoxidized oil, to form a coating composition;
- (i) said polymer composition having a number average molecular weight of 10,000 to 200,000;
- (ii) said polymer composition having a lactide monomer concentration of less than about 5% by weight;
- and
- (iii) said lactide reactant being selected from the group consisting of L-lactide, D-lactide and mixtures thereof;
- (iv) said polymer composition being formed from a reaction mixture comprising at least 3% by weight meso-lactide, based on the total weight of meso-lactide and lactide reactant;
- and
- (b) applying said coating composition to a paper substrate.
9 more elements
Dependencies are inferred from the claim text.