Modified epoxy resin and composition
AssigneeDaicel Chemical Industries, Ltd.
InventorsShoji Watanabe, Kiyoshi Okitsu
Life of this patent
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Abstract
An epoxy resin having hydroxyl groups is modified with .epsilon.-caprolactone by effecting the ring opening polymerization of .epsilon.-caprolactone onto the hydroxyl groups contained in the epoxy resin. The modified epoxy resin is further combined with a polycarboxylic anhydride and a promotor for curing, or polyamine to give a curable composition. The modified epoxy resin is further modified by reacting the epoxy groups therein with a primary or secondary amine. Both the modified resin and the compositions are useful as coating.
Claims6
A lactone-modified epoxy resin which is the reaction product obtained by effecting ring-opening polymerization of from 3 to 95 parts by weight of .epsilon.-caprolactone, in the presence of from 97 to 5 parts by weight of an epoxy resin having terminal unreacted epoxy groups and having at least one hydroxyl group in the epoxy resin molecule, at a temperature of from 100.degree. to 240.degree. C., in the presence of a catalytically effective amount of a catalyst effective for polymerizing .epsilon.-caprolactone and selected from the group consisting of titanium compounds, organotin compounds and stannous halides, the conditions being effective to form poly(.epsilon.-caprolactone) as a side chain bonded to the epoxy resin molecule at the location of said hydroxyl group or groups, said poly(.epsilon.-caprolactone) side chain having a terminal primary hydroxyl group at the end thereof remote from said epoxy resin molecule, whereby to obtain a lactone-modified epoxy resin, and then reacting at least some of said terminal unreacted epoxy groups of said lactone-modified epoxy resin with a primary or secondary amine.
A lactone-modified epoxy resin as claimed in claim 2 in which the amount of .epsilon.-caprolactone is from 5 to 70 parts by weight and the amount of said epoxy resin is from 95 to 30 parts by weight, and in which the polymerization is performed at a temperature of from 120.degree. to 200.degree. C., in the presence of a catalytically effective amount of a catalyst selected from the group consisting of tetrabutyl titanate, tetrapropyl titanate, tetraethyl titanate, stannous octoate, dibutyltin oxide, dibutyltin laurate, stannous chloride, stannous bromide and stannous iodide.
Dependencies are inferred from the claim text.