Paper having a melt-stable lactide polymer coating and process for manufacture thereof
AssigneeCargill, Incorporated
InventorsPatrick R. Gruber, Jeffrey J. Kolstad, Christopher M. Ryan, Eric S. Hall, Robin S. 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.
Claims51
A paper product having a coating thereon, said coating formed from a melt stable lactide polymer composition comprising:
- i) a plurality of poly(lactide) polymer chains, said polymer chains being reaction products of polymerizing a lactide mixture comprising about 3 to about 50 percent by weight meso-lactide, with the remaining lactide being selected from the group consisting of L-lactide, D-lactide and mixtures thereof, said plurality having a number average molecular weight of from about 10,000 to about 200,000;
- ii) lactide in a concentration of less than about 5 percent by weight;
- and
- iii) water, if present at all, present in a concentration of less than about 2000 parts per million.
A process for coating paper, said process comprising the steps of:
- a) providing a paper substrate to be coated,
- b) providing a melt-stable lactide polymer composition comprising:
- i) a plurality of poly(lactide) polymer chains, said plurality of polymer chains being reaction products of polymerizing a lactide mixture comprising about 3 to about 50 percent by weight meso-lactide, with the remaining lactide being selected from the group consisting of L-lactide, D-lactide and mixtures thereof, said plurality of polymer chains having a number average molecular weight of about 10,000 to about 200,000;
- ii) lactide in a concentration of less than about 5 percent by weight;
- and
- iii) water, if present at all, present in a concentration of less than about 2000 parts per million;
- and
- c) coating said polymer composition onto said substrate.
Dependencies are inferred from the claim text.