Compositions containing aromatic isocyanate functional components and aliphatic aromatics isocyanate functional components having improved cure speed

1. A composition comprising

in Part 1

a) one or more isocyanate functional components having aromatic isocyanate functional groups which comprises one or more prepolymers having aromatic isocyanate functional groups;

b) one or more isocyanate functional components having aliphatic isocyanate functional groups;

in Part 2

c) one or more compounds having more than one isocyanate reactive groups;

d) one or more fillers in one or both parts comprising one or more clays; and

e) one or more catalysts which catalyze the reaction of isocyanate functional groups with isocyanate reactive groups:

wherein the ratio of aromatic isocyanate functional groups to isocyanate reactive groups is from 0.95 to 1.05 and the ratio of aromatic isocyanate functional groups and aliphatic isocyanate functional groups to isocyanate reactive groups is from 1.10 to 1.30; and the one or more isocyanate functional components having aromatic isocyanate functional groups comprises one or more polyisocyanates having aromatic isocyanate functional groups and one or more isocyanate functional group containing prepolymers having in their backbones the residue of one or more chains of one or more polypropylene oxides, copolymers of ethylene oxide and propylene oxide or mixtures thereof wherein equivalent weight of the chains are predominantly greater than about 780 and having aromatic isocyanate functional groups; and

the isocyanate reactive component comprises one or more polypropylene oxides, copolymers of ethylene oxide and propylene oxide or mixtures thereof having equivalent weights predominantly about 960 or greater and terminal groups which are reactive with isocyanate groups, and

one or more low molecular weight compounds having two or more isocyanate reactive groups and a molecular weight of 120 or less.

2. A composition according to claim 1 wherein the copolymers of ethylene oxide and propylene oxide contain about 5 to about 40 percent by weight of ethylene oxide units.

3. A composition according to claim 1 wherein the lap shear strength of the composition 4 hours after application to substrates is about 9.0 MPa or greater.

4. A composition according to claim 1 wherein the lap shear strength of the composition 1 hours after application to substrates is about 3.5 MPa or greater.

5. A composition according claim 1 wherein the composition after contacting the two parts exhibits a tack free time of about 3 minutes or greater.

6. A method of bonding two or more substrates together comprising

acting Part 1 and Part 2 according to claim 1 ;

ii) contacting the mixture of step i) with one or more substrates;

iii) contacting the substrates together with the mixture of step i) disposed between the substrates; and

iv) allowing the mixture of step i) to cure so as to bond the substrates together.

7. A method according to claim 6 wherein the cure of the mixture of step i) is accelerated by exposing the substrates with the mixture of step i) disposed between the substrates to elevated temperatures.

8. A composition according to claim 1 wherein the ratio of aromatic isocyanate functional groups and aliphatic isocyanate functional groups to isocyanate reactive groups is from 1.10 to 1.20.

9. A composition according to claim 1 wherein the composition further comprises a polyoxyalkylene polyamine having 2 or more amines per polyamine.

10. A composition according to claim 1 wherein the one or more catalysts comprise a mixture of a tertiary amine and one or more of organotin compounds and metal alkanoates.

11. A composition according to claim 1 wherein the one or more isocyanate functional components having aromatic isocyanate functional groups comprise oligomeric aromatic polyisocyanates.