Melt-Processed Films of Thermoplastic Cellulose and Microbial Aliphatic Polyester
Films made from a thermoplastic cellulose and microbially-derived, renewable and biodegradable aliphatic polyester such as polyhydroxyalkanoates are disclosed. The films, made from two relatively brittle materials exhibit more ductility and strength than the materials from which the film is made. The film may be incorporated into absorbent personal care product including but not limited to training pants, diaper, bandages, and bed pads.
1 . A melt-processed thermoplastic material film comprising:
a blend of about 5% to about 95% of a thermoplastic cellulose having a melting point temperature between about 100° C. to about 200° C., and about 5 wt. % to about 95 wt. % of a polyhydroxyalkanoate with an average molecular weight of at least 20,000 g/mol.
2 . The film according to claim 1 wherein the thermoplastic cellulose comprises cellulose alkanoate with two or more different alkanoate groups.
3 . The film according to claim 1 wherein the thermoplastic cellulose comprises cellulose acetate butyrate.
4 . The film according to claim 1 wherein the thermoplastic cellulose comprises alkyl cellulose and hydroxyalkyl cellulose.
5 . The film according to claim 1 wherein the thermoplastic cellulose comprises alkyl cellulose and hydroxyalkyl cellulose with 1 to 10 carbon in an alkyl or hydroxyalkyl groups.
6 . The film according to claim 1 wherein the thermoplastic cellulose comprises methyl cellulose, ethyl cellulose, methyl propyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and/or hydroxybutyl cellulose.
7 . The film according to claim 1 wherein the thermoplastic cellulose comprises cellulose acetate butyrate with a butyrate to acetate weight ratio of about 1:1 or greater.
8 . The film according to claim 9 , wherein said cellulose acetate butyrate has an average molecular weight of at least 20,000 g/mol.
9 . The film according to claim 9 , wherein said cellulose acetate butyrate ranges from about 20 wt. % to about 80 wt. % in the blend.
10 . The film according to claim 9 , wherein said cellulose acetate butyrate is 5 wt. % to about 90 wt. %.
11 . The film according to claim 1 wherein the thermoplastic material is in the form of a film having a thickness of about 0.5 to about 4.5 mil in both the machine and cross direction, and wherein the film comprises about 50 percent cellulose acetate butyrate and about 50 percent polyhydroxy butyrate.
12 . An absorbent article comprising:
a backsheet comprising the film of claim 1 ;
a top sheet attached to the backsheet, and
an absorbent core disposed between the backsheet and topsheet, and
directly attached to either the backsheet or the topsheet.
13 . The absorbent article of claim 20 wherein the absorbent article is configured as a training pant, diaper, an adult incontinent garment, a feminine pad, a feminine pantiliner, a bandage or a bed pad.