Moisture curing polyurethane hot-melt adhesive

A moisture-curing polyurethane hotmelt adhesive comprising at least one polyurethane prepolymer which is the reaction product of:

• about 15 to about 45% by weight of at least one aromatic diisocyanate;
• about 10 to about 70% by weight of at least one polypropylene glycol that has a molecular weight of about 100 to about 1,000;
• about 5 to about 65% by weight of a mixture of at least two polyester glycols with different glass transition temperatures, as measured by DSC;
• and
• about 0.1 to about 16% by weight of diol chain extender, said weights being based on the hotmelt adhesive as a whole.

A moisture-curing polyurethane hotmelt adhesive comprising

• (a) at least one polyurethane prepolymer which is the reaction product of:
• (i) about 25 to about 40% by weight of at least one aromatic diisocyanate selected from the group consisting of toluene diisocyanate, 4,4'-diphenyl methane diisocyanate and 2,4'-diphenyl methane diisocyanate and mixtures thereof;
• (ii) about 15 to about 35% by weight of at least one polypropylene glycol that has a molecular weight of about 250 to about 700;
• (iii) about 20 to about 40% by weight of a mixture of at least two polyester glycols with different glass transition temperatures, as measured by DSC, wherein the glass transition temperatures of the polyester mixture are in the range from about -50 to about +50.degree. C., one glass transition temperature being below about 0.degree. C. and the other above about 0.degree. C.;
• and
• (iv) about 1 to about 8% by weight of at least one diol chain extender;
• (b) about 3 to about 10% by weight of a hydrocarbon resin;
• and
• (c) about 0.01 to about 0.1% by weight of stabilizer;
• said weights being based on the hotmelt adhesive as a whole.

A moisture-curing polyurethane hotmelt adhesive, which comprises:

• (a) at least one polyurethane prepolymer comprising the reaction product of:
• (i) at least one polyisocyanate;
• (ii) at least one polyalkylene glycol in a concentration of more than 10% by weight, based on the hotmelt adhesive as a whole;
• (iii) at least one polyester glycol;
• and
• (iv) at least one chain extender;
• and
• (b) at least one hydrocarbon resin.

A moisture-curing polyurethane hotmelt adhesive, which comprises at least one polyurethane prepolymer comprising the reaction product of:

• (i) at least one polyisocyanate;
• (ii) at least one polypropylene glycol having a molecular weight of about 100 to about 1,000 in a concentration of more than 10% by weight, based on the hotmelt adhesive as a whole;
• (iii) at least one polyester glycol;
• and
• (iv) at least one chain extender.

A moisture-curing polyurethane hotmelt adhesive, which comprises at least one polyurethane prepolymer comprising the reaction product of:

• (i) at least one polyisocyanate;
• (ii) at least one polyalkylene glycol in a concentration of more than 10% by weight, based on the hotmelt adhesive as a whole;
• (iii) at least one polyester glycol;
• and
• (iv) at least one aromatic chain extender having a molecular weight below about 500.

A moisture-curing polyurethane hotmelt adhesive, which comprises:

• (a) at least one polyurethane prepolymer comprising the reaction product of:
• (i) at least one polyisocyanate;
• (ii) at least one polyalkylene glycol in a concentration of more than 10% by weight, based on the hotmelt adhesive as a whole;
• (iii) at least one polyester glycol;
• and
• (iv) at least one chain extender;
• and
• (b) at least one stabilizer selected from the group consisting of phosphoric acid, phosphorous acid and toluene sulfonyl isocyanate.