US5536807A — Melt-stable semi-crystalline lactide polymer film…

Claim 1

Independent Claim 130 words

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.

Claim 2

Dependent Claim 130 words

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.

Claim 3

Dependent Claim 24 words

The film of claim 1 wherein said plurality of poly(lactide) polymer chains have a number average molecular weight from about 20,000 to about 275,000.

Claim 4

Dependent Claim 24 words

The film of claim 1 wherein said plurality of poly(lactide) polymer chains have a number average molecular weight from about 40,000 to about 250,000.

Claim 5

Dependent Claim 26 words

The film of claim 1 wherein said polymer chains are reaction products of polymerizing a lactide mixture comprising less than about 9 percent by weight meso-lactide.

Claim 6

Dependent Claim 18 words

The film of claim 1 wherein said concentration of water is less than about 500 parts per million.

Claim 7

Dependent Claim 18 words

The film of claim 1 wherein said concentration of water is less than about 100 parts per million.

Claim 8

Dependent Claim 14 words

The film of claim 1 wherein said polymer composition further comprises a stabilizing agent.

Claim 9

Dependent Claim 12 words

The film of claim 7 wherein said stabilizing agent is an antioxidant.

Claim 10

Dependent Claim 13 words

The film of claim 7 wherein said stabilizing agent is a water scavenger.

Claim 11

Dependent Claim 12 words

The film of claim 8, wherein said antioxidant comprises a phosphite-containing compound.

Claim 12

Dependent Claim 15 words

The film of claim 8, wherein said antioxidant comprises a hindered phenolic or phenolic compound.

Claim 13

Dependent Claim 54 words

The film of claim 8, wherein said antioxidant is selected from the group consisting of trialkyl phosphites, mixed alkyl/aryl phosphites, alkylated aryl phosphites, sterically hindered aryl phosphites, aliphatic spirocyclic phosphites, sterically hindered phenyl spirocyclics, sterically hindered bisphosphonites, hydroxyphenyl propionates, hydroxy benzyls, alkylidene bisphenols, alkyl phenols, aromatic amines, thioethers, hindered amines, hydroquinones and mixtures thereof.

Claim 14

Dependent Claim 26 words

The film of claim 9, wherein said water scavenger is selected from the group consisting of carbodiimides, anhydrides, acyl chlorides, isocyanates, alkoxy silanes and mixtures thereof.

Claim 15

Dependent Claim 33 words

The film of claim 9, wherein said water scavenger is a desiccant selected from the group consisting of clay, alumina, silica gel, zeolites, calcium chloride, calcium carbonates, sodium sulfate, bicarbonates and mixtures thereof.

Claim 16

Dependent Claim 38 words

The film of claim 1 wherein said polymer composition further comprises: iv) catalyst means for catalyzing the polymerization of lactide to form the poly(lactide) polymer chains, said catalyst means incorporated into the melt-stable lactide polymer composition during polymerization.

Claim 17

Dependent Claim 26 words

The film of claim 1 wherein said plurality of poly(lactide) polymer chains is the reaction product of polymerization at a temperature greater than about 160° C.

Claim 18

Dependent Claim 51 words

The film of claim 1 wherein said polymer composition further comprises a plasticizer selected from the group consisting of alkyl phosphate esters, dialkylether diesters, tricarboxylic esters, epoxidized oils and esters, polymeric polyesters, polyglycol diesters, alkyl alkylether diesters, aliphatic diesters, alkylether monoesters, citrate esters, dicarboxylic esters, esters of glycerine and mixtures thereof.

Claim 19

Dependent Claim 31 words

The film of claim 1 wherein said polymer composition further comprises a nucleating agent which is a crystalline polymer with a melting point greater than the processing temperature of the poly(lactide).

Claim 20

Dependent Claim 38 words

The film of claim 1 wherein said polymer composition further comprises a pigment selected from the group consisting of titanium dioxide, clays, calcium carbonate, talc, mica, silica, iron oxide, iron hydroxide, carbon black, magnesium oxide and mixtures thereof.

Claim 21

Dependent Claim 14 words

A semi-crystalline poly(lactide) film wherein a substantial portion of crystallinity was induced through orientation.

Claim 22

Dependent Claim 14 words

A semi-crystalline poly(lactide) film wherein a substantial portion of crystallinity was induced through orientation.

Claim 23

Dependent Claim 14 words

The film of claim 20 wherein said orientation is in a plurality of directions.

Claim 24

Dependent Claim 49 words

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.

Claim 25

Dependent Claim 49 words

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.

Claim 26

Dependent Claim 31 words

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.

Claim 27

Dependent Claim 31 words

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.

Claim 28

Dependent Claim 25 words

The film of claim 23 wherein the sequences of the minor component have less than 0.01 probability of comprising at least three lactic acid residuals.

Claim 29

Dependent Claim 153 words

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.

Claim 30

Dependent Claim 153 words

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.

Claim 31

Dependent Claim 26 words

The process of claim 25 wherein said polymer chains are reaction products of polymerizing a lactide mixture comprising less than about 9 percent by weight meso-lactide.

Claim 32

Dependent Claim 18 words

The process of claim 25 wherein said concentration of water is less than about 100 parts per million.

Claim 33

Dependent Claim 14 words

The process of claim 25 wherein said polymer composition further comprises a stabilizing agent.

Claim 34

Dependent Claim 12 words

The process of claim 28 wherein said stabilizing agent is an antioxidant.

Claim 35

Dependent Claim 13 words

The process of claim 28 wherein said stabilizing agent is a water scavenger.

Claim 36

Dependent Claim 12 words

The process of claim 29 wherein said antioxidant is a phosphite-containing compound.

Claim 37

Dependent Claim 15 words

The process of claim 29 wherein said antioxidant is a hindered phenolic or phenolic compound.

Claim 38

Dependent Claim 54 words

The process of claim 29 wherein said antioxidant is selected from the group consisting of trialkyl phosphites, mixed alkyl/aryl phosphites, alkylated aryl phosphites, sterically hindered aryl phosphites, aliphatic spirocyclic phosphites, sterically hindered phenyl spirocyclics, sterically hindered bisphosphonites, hydroxyphenyl propionates, hydroxy benzyls, alkylidene bisphenols, alkyl phenols, aromatic amines, thioethers, hindered amines, hydroquinones and mixtures thereof.

Claim 39

Dependent Claim 26 words

The process of claim 30 wherein said water scavenger is selected from the group consisting of carbodiimides, anhydrides, acyl chlorides, isocyanates, alkoxy silanes and mixtures thereof.

Claim 40

Dependent Claim 33 words

The process of claim 30 wherein said water scavenger is a desiccant selected from the group consisting of clay, alumina, silica gel, zeolites, calcium chloride, calcium carbonates, sodium sulfate, bicarbonates and mixtures thereof.

Claim 41

Dependent Claim 38 words

The process of claim 25 wherein said polymer composition further comprises: (iv) catalyst means for catalyzing the polymerization of lactide to form the poly(lactide) polymer chains, said catalyst means incorporated into the melt-stable lactide polymer composition during polymerization.

Claim 42

Dependent Claim 27 words

The process of claim 25 wherein said plurality of poly(lactide) polymer chains are the reaction products of polymerization at a temperature of greater than about 160° C.

Claim 43

Dependent Claim 14 words

The process of claim 25 further comprising the step of: (c) orienting the film.

Claim 44

Dependent Claim 11 words

The process of claim 38 wherein the orientation step induces crystallinity.

Claim 45

Dependent Claim 15 words

The process of claim 38 further comprising the step of: (d) heat setting the film.

Claim 46

Dependent Claim 98 words

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.

Claim 47

Dependent Claim 98 words

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.

Claim 48

Dependent Claim 133 words

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.

Claim 49

Dependent Claim 133 words

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.

Claim 50

Dependent Claim 11 words

The article according to claim 42, said article being a diaper.

Claim 51

Dependent Claim 12 words

The article according to claim 42, said article being a packaging film.

Claim 52

Dependent Claim 13 words

The article according to claim 42, said article being an agricultural mulch film.

Claim 53

Dependent Claim 13 words

The article according to claim 42, said article being a shrink wrap film.

Claim 54

Dependent Claim 11 words

The article according to claim 42, said article being a bag.

Claim 55

Dependent Claim 11 words

The article according to claim 42, said article being a tape.

Claim 56

Dependent Claim 59 words

The film of claim 1 wherein said polymer composition further comprises a filler selected from the group consisting of cellulose, wheat, starch, modified starch, chitin, chitosin, keratin, cellulose acetate, cellulosic materials derived from agricultural products, gluten, net shell flour, wood flour, corn cob flour, guar gum, talc, silica, mica, kaolin, titanium dioxide, wollastonite, perlite, diatomaceous earth and mixtures thereof.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1999-07-16	2000-01-15	2000-07-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2003-07-16	2004-01-15	2004-07-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2007-07-16	2008-01-15	2008-07-16	$7700.00	Window Closed / Lapsed

Melt-stable semi-crystalline lactide polymer film and process for manufacture thereof

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