Epoxy latent catalyst
AssigneeHitco
InventorEduard P. Babayan
Life of this patent
Estimating the term…
Abstract
A catalyst for forming ambient temperature stable diamino-diphenyl sulfone-epoxy composition comprises the half-salt of a strong aromatic sulfonic acid such as toluene sulfonic acid and an imidazole, preferably an alkylated imidazole such as 2-ethyl-4-methylimidazole. The composition fully cures at moderate temperature to form a humidity resistant resin having a high heat distortion temperature and can be impregnated onto reinforcing fibers such as graphite to form composites.
Claims14
A curable composition having an extended pot life at temperatures below 200 degrees F. comprising:
- 0.25% to 10% by weight of a half-salt of an imidazole and a strong aromatic acid soluble in epoxy selected from benzene sulfonic acid or alkylated benzene sulfonic acid containing 1 to 3 C.sub.1 to C.sub.8 alkyl groups, said imidazole being selected from compounds of the formula;
- ##STR5## where R.sup.1, R.sup.2 and R.sup.3 are selected from hydrogen, alkyl, aralkyl, hydroxyalkyl, cyanoalkyl and phenyl;
- 10% to 35% by weight of a diamino-diphenyl sulfone;
- and
- remainder being an organic material containing a plurality of epoxy groups.
A curable composition having an extended pot life at temperatures below 200 degrees F. comprising:
- 0.25% to 10% by weight of a half-salt of an imidazole and a strong aromatic sulfonic acid soluble in epoxy, said imidazole being selected from compounds of the formula;
- ##STR6## where R.sup.1, R.sup.2 and R.sup.3 are selected from hydrogen, alkyl, aralkyl, hydroxyalkyl, cyanoalkyl and phenyl;
- 10% to 35% by weight of a diamino-diphenyl sulfone;
- and
- remainder being an organic material containing a plurality of epoxy groups selected from epoxidized novolac and epoxidized alkylene dianiline materials.
A composition of matter comprising an organic material containing a plurality of epoxy groups having dissolved therein, and the half-salt of a strong aromatic sulfonic acid selected from benzene sulfonic acid or alkylated benzene sulfonic acid containing 1 to 3 C.sub.1 to C.sub.8 alkyl groups, said sulfonic acid being soluble in epoxy and an imidazole of the formula:
- ##STR7## where R.sup.1, R.sup.2 and R.sup.3 are selected from hydrogen, alkyl, aralkyl, hydroxyalkyl, cyanoalkyl and phenyl.
Dependencies are inferred from the claim text.