Melt-stable semi-crystalline lactide polymer film and process for manufacture thereof
AssigneeCargill, Incorporated
InventorsPatrick R. Gruber, Jeffrey J. Kolstad, Christopher M. Ryan
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Abstract
A semi-crystalline film comprised of a lactide polymer. 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 manufacturing a semi-crystalline film with the lactide polymer composition is also disclosed.
Claims49
A semi-crystalline film exhibiting a net endotherm greater than about 10 joules per gram of poly(lactide) polymer, comprising a melt stable polymer composition, said composition comprising:
- i) a plurality of poly(lactide) polymer chains, said polymer chains being reaction products of polymerizing a lactide mixture comprising less than about 15 percent by weight meso-lactide, with the remaining lactide being selected from the group consisting of L-lactide, D-lactide and mixtures thereof, whereby at least about 85% of the lactide is either L-lactide or D-lactide, said plurality having a number average molecular weight of from about 10,000 to about 300,000;
- ii) residual lactide in a concentration of less than about 2 percent by weight;
- and
- iii) water, if present at all, present in a concentration of less than about 2000 parts per million.
A semi-crystalline poly(lactide) film wherein a substantial portion of crystallinity was induced through orientation.
A semi-crystalline film comprising:
- (i) 50 to 85% by weight of a semi-crystalline lactide polymer composition exhibiting a net endotherm greater than about 10 joules per gram of poly(lactide) polymer;
- (ii) 15 to 30% by weight of a plasticizer;
- and
- (iii) 0 to 20% by weight of a filler.
A semi-crystalline film made of poly(lactide) or poly(lactic acid) wherein sequences of the major lactic acid conformation have at least a 0.5 probability of comprising at least ten lactic acid residuals.
A process for the manufacture of a semi-crystalline film exhibiting a net endotherm greater than about 10 joules per gram of poly(lactide) polymer, said process comprising the steps of:
- a) 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 less than about 15 percent by weight meso-lactide, with the remaining lactide being selected from the group consisting of L-lactide, D-lactide and mixtures thereof, whereby at least about 85% of the lactide is either L-lactide or D-lactide, said plurality of polymer chains having a number average molecular weight of about 10,000 to about 300,000;
- ii) lactide in a concentration of less than about 2 percent by weight;
- and
- iii) water, if present at all, present in a concentration of less than about 2000 parts per million;
- and
- b) extruding said polymer composition into a film.
A process for the manufacture of a semi-crystalline film, said process comprising the steps of:
- (a) providing a composition comprising:
- (i) 50 to 85% by weight of a semi-crystalline lactide polymer composition exhibiting an endotherm greater than about 10 joules per gram of poly(lactide) polymer;
- (ii) about 15 to 30% by weight of a plasticizer;
- (iii) up to 20% by weight of a filler;
- (b) extruding said composition into a semi-crystalline film;
- (c) orienting said film in either the machine direction, the cross direction, or both directions by stretching the film at least 1.1 times its original size.
An article comprising a semi-crystalline film exhibiting a net endotherm greater than about 10 joules per gram of poly(lactide) polymer, comprising a melt stable polymer composition, said composition comprising:
- i) a plurality of poly(lactide) polymer chains, said polymer chains being reaction products of polymerizing a lactide mixture comprising less than about 15 percent by weight meso-lactide, with the remaining lactide being selected from the group consisting of L-lactide, D-lactide and mixtures thereof, whereby at least about 85% of the lactide is either L-lactide or D-lactide, said plurality having a number average molecular weight of from about 10,000 to about 300,000;
- ii) residual lactide in a concentration of less than about 2 percent by weight;
- and
- iii) water, if present at all, present in a concentration of less than about 2000 parts per million.
Dependencies are inferred from the claim text.