Biodegradable/compostable hot melt adhesives comprising polyester of lactic acid

A method of using a biodegradable/compostable composition as a hot melt adhesive comprising the steps of:

• I. providing a composition comprising:
• q) about 10-50 wt-% of a resin grade thermoplastic polylactic acid resin having a molecular weight (Mn) greater than about 30,000 grams per mole;
• and
• r) about 20-90 wt-% of a tackifying resin composition comprising a polymer of lactic acid having a molecular weight (Mn) less than about 20,000 grams per mole and a T.sub.g of about -20.degree. to 60.degree. C.;
• II. applying the adhesive to at least one substrate;
• and
• III. forming a bond among the substrates.

A method of using a biodegradable compostable composition as a hot melt adhesive comprising the steps of:

• I. providing a composition comprising:
• a) about 10-50 wt-% of a thermoplastic resin selected from the group consisting of a polyester urethane resin having a molecular weight (Mn) greater than 30,000 and a linear polyester resin comprising 1-95 wt-% of a hydroxy butyric acid composition and about 5-35 wt-% of a hydroxy valeric acid composition and mixtures thereof;
• and
• b) about 20-90 wt-% of a tackifying resin composition comprising a polymer of lactic acid having a molecular weight (Mn) less than about 30,000 grams per mole and a T.sub.g of less than 110.degree. C.;
• II. applying the adhesive to at least one substrate;
• and
• III. forming a bond among the substrates.