Claims
- 1. A method of preparing a cross-linkable composition comprising admixing:
- (a) a carboxylated latex,
- (b) a cross-linking catalyst, and
- (c) a mixed aliphatic and aromatic polycarbodiimide prepared by a process comprising the following steps seriatim:
- (A) charging a mixture of cycloaliphatic or saturated aliphatic mono- and diisocyanates to a reactor with agitation under an inert atmosphere;
- (B) heating the resultant mixture to about 120.degree. to about 160.degree. C.;
- (C) adding a catalytic amount of a phospholene oxide catalyst to the reactor;
- (D) feeding a mixture of a non-reactive solvent and aromatic mono- and/or diisocyanate to the reactor; and
- (E) maintaining agitation at about 120.degree. to about 160.degree. C. until all of the isocyanate functionality is converted to carbodiimide functionality, with the provisos that:
- (a) said cycloaliphatic moieties contain 6 to about 10 carbons;
- (b) said saturated aliphatic moieties contain from about 4 to about 12 carbons;
- (c) said aromatic moieties contain from 6 to about 16 carbons;
- (d) the molar ratio of all of the mono-to-diisocyanates ranges from about 2:1 to about 2:10; and
- (e) the molar ratio of cycloaliphatic and/or saturated aliphatic isocyanate groups to aromatic isocyanate groups ranges from about 0.5:1 to about 2:1.
- 2. A method of claim 1 wherein the molar ratio of cycloaliphatic and/or saturated aliphatic mono- and diisocyanates to aromatic mono- and diisocyanates ranges from about 0.75:1 to about 1.25:1.
- 3. A method of claim 2 wherein the aliphatic monoisocyanate is butyl isocyanate and the cycloaliphatic diisocyanate is isophorone diisocyanate.
- 4. A method of claim 2 wherein the aromatic diisocyanate is toluene diisocyanate.
- 5. A method of claim 1 using phenyl isocyanate, isophorone diisocyanate and toluene diisocyanate.
- 6. A method of claim 1 carried out in a non-reactive organic solvent.
- 7. A method of claim 6 wherein the solvent is a glycol diester.
- 8. A method of claim 6 wherein the solvent is an aliphatic ester.
- 9. A method of claim 1 wherein the phospholene oxide catalyst is 3-methyl-1-phenyl-2-phospholene-1-oxide.
- 10. A method of claim 1 wherein the cross-linking catalyst is an amine.
Parent Case Info
This application is a division of prior U.S. application Ser. No. 469,434, filing date, Feb. 24, 1983, now U.S. Pat. No. 4,487,964.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3639353 |
Brown |
Feb 1972 |
|
4169866 |
Bonin et al. |
Oct 1979 |
|
Divisions (1)
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Number |
Date |
Country |
Parent |
469434 |
Feb 1983 |
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