Adhesive composition
First Claim
1. In an adhesive composition comprising a polyurethane and polyurea resin system, a catalyst, optionally one or more fillers and optionally a pigment and/or dye,wherein said resin system comprises a prepolymer and a curative composition, said prepolymer being a urethane prepolymer having terminal free --NCO groups, said curative composition comprising one or more polyamines and one or more polyols capable of forming a cross linked polyurethane,the improvement wherein the isocyanate index (--NCO/(--OH+--NH)) of said resin system is from 1.20 to 2 and wherein said one or more polyamines consist essentially of one or more aromatic polyamines, said one or more aromatic polyamines being one or more primary aromatic polyamines with fused polycyclic aromatic rings having at least 2 NH2 groups per molecule, and having H, NH2, C1 to C5 alkyl, or phenyl groups attached to the ring carbons which are not bridge-head carbons.
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Accused Products
Abstract
A polyurethane adhesive formed from (I) an NCO terminated prepolymer with excess of NCO and talc, and (II) a polyol, a urethane catalyst, talc and a minor amount of certain aryl or aromatic polyamines exhibits good sag and thixotropic properties and, also, exhibits good lap shear strength when cured between treatment-free substrates.
68 Citations
35 Claims
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1. In an adhesive composition comprising a polyurethane and polyurea resin system, a catalyst, optionally one or more fillers and optionally a pigment and/or dye,
wherein said resin system comprises a prepolymer and a curative composition, said prepolymer being a urethane prepolymer having terminal free --NCO groups, said curative composition comprising one or more polyamines and one or more polyols capable of forming a cross linked polyurethane, the improvement wherein the isocyanate index (--NCO/(--OH+--NH)) of said resin system is from 1.20 to 2 and wherein said one or more polyamines consist essentially of one or more aromatic polyamines, said one or more aromatic polyamines being one or more primary aromatic polyamines with fused polycyclic aromatic rings having at least 2 NH2 groups per molecule, and having H, NH2, C1 to C5 alkyl, or phenyl groups attached to the ring carbons which are not bridge-head carbons.
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9. A laminate comprising two substrates adhered together with a heat cured adhesive, said adhesive prior to curing comprising a polyurethane and polyurea resin system, a catalyst, optionally one or more fillers and optionally a pigment and/or dye,
wherein said resin system comprises a prepolymer and a curative composition, said prepolymer being a urethane prepolymer having terminal free --NCO groups, said curative composition comprising one or more polyamines and one or more polyols capable of forming a cross linked polyurethane, wherein the isocyanate index (--NCO/(--OH+--NH)) of said resin system is from 1.20 to 2 and wherein said one or more polyamines consist essentially of one or more aromatic polyamines, said one or more aromatic polyamines being (a) one or more primary aromatic polyamines having the formula ##STR3## where R1 is ##STR4## or the same as any of R2 through R6 and where the R2 through R6 and R7 through R11 are independently selected from the groups of: - H;
NH2 ;
C1 to C5 alkyl;
or phenyl;
wherein A is an alkylene hydrocarbon containing 0 to 12 carbons and each molecule contains at least 2 NH2 groups, when R1 is not Formula II, at least 4 of the R1 through R6 groups are not H, and Formula I is not diethyl toluene diamine, and where R1 is Formula II and A is 1 to 12 carbon atoms at least 4 of the R2 through R11 groups are not H or(b) one or more primary aromatic polyamines with fused polycyclic aromatic rings having at least 2 NH2 groups per molecule, and having H, NH2, C1 to C5 alkyl, or phenyl groups attached to the ring carbons which are not bridge-head carbons or combinations thereof. - View Dependent Claims (8, 10, 11, 13, 14, 15, 16)
- H;
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20. In an adhesive composition comprising a polyurethane and polyurea resin system, a catalyst, optionally one or more fillers and optionally a pigment and/or dye, and wherein said resin system comprises a prepolymer and a curative composition, said prepolymer being a urethane prepolymer having terminal free --NCO groups, said curative composition comprising one or more primary polyamines and one or more polyols capable of forming a cross linked polyurethane,
the improvement wherein the isocyanate index of NCO groups to OH+NH2 groups of said resin system is from 1.20 to 2 and wherein said one or more primary polyamines consist of one or more aromatic polyamines having an effective reactivity with the prepolymer to form a polyurethane having good sag resistance and good lap shear properties and being one or more primary aromatic polyamines with fused polycyclic aromatic rings having at least 2 NH2 groups per molecule, and having H, NH2, C1 to C5 alkyl, or phenyl groups attached to the ring carbons which are not bridge-head carbons.
- 27. In an adhesive composition comprising a resin system, a catalyst, optionally one or more fillers and optionally a pigment and/or dye, and wherein said resin system comprises a prepolymer and a curative composition, said prepolymer being a urethane prepolymer formed by reacting a polyol with polyisocyanate in a equivalent ratio (NCO/OH) of about 2 to about 20 and said curative composition comprising a primary polyamine and a polyol and wherein the isocyanate index NCO/(OH+NH2) of said resin system is about 1.20 to 2, the improvement wherein said composition is free of fast reacting primary aliphatic amines and wherein said polyamine of said curative is one or more primary aromatic polyamines with fused polycyclic aromatic rings having at least 2 NH2 groups per molecule, and having H, NH2, C1 to C5 alkyl, or phenyl groups attached to the ring carbons which are not bridge-head carbons.
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33. A process for adhesively joining two or more substrates individually selected from fiberglass reinforced plastic, metal, and plastic free of a surface primer, the process comprising;
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mixing a urethane prepolymer having unreacted isocyanate terminal groups with a curative component forming a urethane adhesive, wherein said curative component comprises one or more polyols and one or more polyamines having primary amine groups;
wherein all said primary amines consist essentially of aromatic primary amines;applying said urethane adhesive to the two or more substrates; thickening said urethane adhesive by forming homogeneously dispersed urea linkages from the isocyanate terminal groups and said one or more aromatic primary polyamines; and heating said urethane adhesive to a temperature above 50°
C. to cure said urethane adhesive and bond said two or more substrates;said one or more primary polyamines being used in amounts from 0.5 to 3 parts by wt. per 100 parts by wt. of said curative component and they consist essentially of (a) one or more primary aromatic polyamines having the formula ##STR5## where R1 is ##STR6## or the same as any of R2 through R6 and where the R2 through R6 and R7 through R11 are independently selected from the groups of;
H;
NH2 ;
C1 to C5 alkyl;
or phenyl, A is an alkylene hydrocarbon containing 0 to 12 carbons and each molecule contains at least 2 NH2 groups, where R1 is not Formula II, at least 4 of the R1 through R6 groups are not H, and Formula I is not diethyl toluene diamine, and where R1 is Formula II and A is 1 at least 4 of the R2 through R11 groups are not H, or(b) one or more primary aromatic polyamines with fused polycyclic aromatic rings having at least 2 NH2 groups per molecule, and having H, NH2, C1 to C5 alkyl, or phenyl groups attached to the ring carbons which are not bridge-head carbons, or combinations thereof, and wherein said thickening occurs in 3 seconds or less after said mixing process. - View Dependent Claims (34, 35)
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Specification