One-component polyurethane adhesive compositions

Claim 2

A heat-curable one-component polyurethane composition, comprising: (a) a secondary or tertiary aliphatic diisocyanate prepolymer; (b) a polyol compound; (c) a chain extender selected from the group consisting of sucrose and sorbitol; and (d) a curingly effective amount of a catalyst selected from the group consisting of magnesium acetylacetonate, nickel acetylacetonate, magnesium stearate, cadmium stearate, and organic acid salts of 1,8-diazabicyclo[5.4.0]undec-7-ene.

Claim 3

A polyurethane composition according to claim 1 wherein the catalyst is magnesium stearate or cadmium stearate, at a concentration of from about 0.05% to about 1% by weight based on the weight of the composition.

Claim 4

A polyurethane adhesive composition according to claim 1 wherein the catalyst is magnesium acetylacetonate or nickel acetylacetone, at a concentration of from about 0.01% to about 4% by weight, based on the weight of the composition.

Claim 5

A polyurethane composition according to claim 1 wherein the catalyst is an oleic acid salt or a 2-ethylhexanoic acid salt of 1,8-diazabicyclo[5.4.0]undec-7-ene.

Claim 6

A polyurethane composition according to claim 1, wherein said catalyst is present at a concentration of from about 0.05% to about 2% by weight, based on the weight of the composition.

Claim 7

A polyurethane composition according to claim 1 wherein said secondary or tertiary aliphatic diisocyanate prepolymer is formed as a reaction product of a hydroxyl-terminated polyester or polyether and a secondary or tertiary aliphatic diisocyanate compound.

Claim 8

A polyurethane composition according to claim 6 wherein said polyester or polyether has an equivalent weight of from about 100 to about 2000.

Claim 9

A composition according to claim 6 wherein said secondary or tertiary aliphatic diisocyanate compound is selected from the group consisting of: α,α,α',α'-tetramethyl-1,3-xylylene diisocyanate; α,α,α',α'-tetramethyl-1,4-xylylene diisocyanate; methylenebis(4-cyclohexylisocyanate);

Claim 10

4-cyclohexylene diisocyanate; and 1,8-p-menthane diisocyanate.

Claim 11

4-cyclohexylene diisocyanate; and 1,8-p-menthane diisocyanate.

Claim 12

A composition according to claim 8 wherein said polyol compound (b) is selected from the group consisting of: polypropylene glycol; hydroxyl-terminated poly(ethylene adipate): hydroxyl-terminated poly(butylene adipate): polycaprolactone; poly(tetramethylene ether glycol): trifunctional polymers obtained by chain extending glycerol or trimethylol propane with propylene oxide, and/or caprolactone units; polyesters made from dibasic acids, diols and triols to provide polymers having more than two hydroxyl groups per molecule; and polyacrylates containing hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, or hydroxypropyl methacrylate repeating units.

Claim 13

A process for bonding substrate workpieces with a polyurethane adhesive, comprising applying a wet film of said polyurethane composition of claim 1 interposed between and in contact with said substrate workpieces, and curing same at elevated temperature to form a solid polyurethane film adhesively bonding said substrate workpieces to one another.

Claim 14

A process according to claim 10 wherein the catalyst in said polyurethane composition is magnesium stearate or cadmium stearate, at a concentration of from about 0.05% to about 1% by weight based on the weight of the composition.

Claim 15

A process according to claim 10 wherein the catalyst in said polyurethane composition is magnesium acetylacetonate or nickel acetylacetonate, at a concentration of from about 0.01% to about 4% by weight, based on the weight of the composition.

Claim 16

A process according to claim 10 wherein the catalyst in said polyurethane composition is an oleic acid salt or a 2-ethylhexanoic acid salt of 1,8-diazabicyclo[5.4.0]undec-7-ene.

Claim 17

A process according to claim 10 wherein said secondary or tertiary aliphatic diisocyanate prepolymer in said polyurethane composition is formed as a reaction product of a hydroxyl-terminated polyester or polyether and a secondary or tertiary diisocyanate compound.

Claim 18

A process according to claim 14 wherein said polyester or polyether has an equivalent weight of from about 100 to about 2000.

Claim 19

A process according to claim 14 wherein said secondary or tertiary aliphatic diisocyanate compound in said polyurethane composition is selected from the group consisting of: α,α,α',α'-tetramethyl-1,3-xylylene diisocyanate, α,α,α',α'-tetramethyl-1,4-xylylene diisocyanate; methylenebis(4-cyclohexyl-isocyanate); isophorone diisocyanate; 1,4-cyclohexylene diisocyanate; and 1,8-p-menthane diisocyanate.

Claim 20

A process according to claim 10, wherein said polyol compound in said polyurethane composition is selected from the group consisting of: polypropylene glycol; hydroxyl-terminated poly(ethylene adipate): hydroxyl-terminated poly(butylene adipate); polycaprolactone; poly(tetramethylene ether glycol); trifunctional polymers obtained by chain extending glycerol or trimethylolpropane with propylene oxide, and/or caprolactone units; polyesters made from dibasic acids, diols and triols to provide polymers having more than two hydroxyl groups per molecule; and polyacrylates containing hydroxyethyl acrylate or hydroxyethyl methacrylate repeating units.

Claim 21

An article comprising an assembly of substrate workpieces adhesively bonded to one another by a cured film of the heat-curable polyurethane composition of claim 1.