Polyurethane sealant compositions having high filler levels
View Patent ↗In one aspect, this invention is a composition comprising a urethane prepolymer having isocyanate moieties; a catalytic amount of a compound which catalyzes the reaction of isocyanate moieties with water or an active hydrogen containing compound; and untreated calcium carbonate as filler. The composition of the invention can be used to bond a window into a structure especially for the automobile windshield installation with good adhesion strength and durability.
1. A composition comprising:
(A) from about 40 parts to about 70 parts by weight of one or more urethane prepolymers having isocyanate moieties;
(B) a catalytic amount of from about 0.15 parts by weight to about 2.0 parts by weight of one or mere compounds containing one or more tertiary amine groups;
(C) from about 10 to about 35 parts by weight of carbon black;
(D) from about 30 to about 40 parts by weight of untreated calcium carbonate;
wherein the amounts are based on the total weight of the composition.
2. A con position according to claim 1 wherein the one or more compounds containing one or more tertiary amine groups is one or more dimorpholino dialkyl ethers wherein the morpholino groups may be substituted with groups which do not interfere in the catalytic effect of the one or more compounds containing one or more tertiary amine groups.
3. A composition according to claim 2 wherein the one or more compounds containing one or more tertiary amine groups is dimorpholino diethylether.
4. A composition according to claim 1 wherein the one urethane prepolymers is derived from a polyol containing alkylene oxide units of ethylene oxide, propylene oxide or mixtures thereof.
5. A composition according to claim 1 wherein the one or more urethane prepolymers is derived from an aromatic isocyanate.
6. A composition according to claim 5 wherein the one or more urethane prepolymers is derived from methylene diphenyl diisocyanate.
7. A composition according to claim 1 wherein the composition further comprises one or more plasticizers.
8. A composition according to claim 1 wherein form about 10 to about 25 parts by weight of carbon black is present.
9. A composition according to claim 8 wherein the amount of the untreated calcium carbonate is 34 to 40 parts by weight.
10. A composition according to claim 9 wherein the catalyst is a dimorpholino dialkyl ether.
11. A method of bonding glass or an abrasion resistant coating coated plastic to a substrate which comprises applying a composition according to claim 1 to the glass or coated plastic surface or the substrate surface; contacting the glass or coated plastic and substrate such that the composition is located between the glass or coated plastic and the substrate; allowing the composition to cure so as to bond the glass or coated plastic to the substrate.
12. A method according to claim 11 wherein the glass to which the adhesive is bonded has a ceramic frit coated on the surface and the substrate surface has a coating thereon.
13. A method according to claim 12 wherein the glass is primed and the coated substrate surface is either primed or unprimed.
14. A method according to claim 12 wherein the substrate is an automobile and the glass or coated plastic is adapted for use as a window.
15. A method according to claim 11 wherein the one or more compounds containing one or more tertiary amine groups is dimorpholino diethylether.
16. A method according to claim 11 wherein from about 10 to about 25 parts by weight of carbon black is present.