Abstract The alkali-soluble polyester resins described herein contain trimellitic anhydride in the amount of 41 to 44 parts by weight, dipropylene glycol in the amount of 28 to 31 parts by weight, glycerol in the amount of 6.3 to 7.2 parts by weight and castor oil in the amount of 20 to 26 parts by weight of the total composition. In addition, neopentyl glycol may be substituted for dipropylene glycol in amounts up to 16 parts by weight of the total composition, in which case the combined proportion of dipropylene glycol and neopentyl glycol may be reduced to 26.5 parts by weight. The components are proportioned within the ranges stated to give an OH/COOH ratio of from 1.05:1 to 1.15:1. When fully cured, the resins are useful as insulating coatings on wire.
An electric wire coated with a resin film which is the cured reaction product of the following components: trimellitic anhydride in the amount of from 41 to 44 parts by weight of the total weight of the resin, castor oil, in the amount of 20 to 26 parTs by weight of the total weight of the resin, one or more short-chain diols containing hydroxyl groups and containing less than 10 carbon atoms per molecule, said diols including at least 50 percent by weight of dipropylene glycol, and being present in the amount of from 28 to 31 parts by weight of the total weight of the resin, and glycerol in the amount of 6.3 to 7.2 parts by weight of the total weight of the resin, said components being combined within said parts by weight ranges to give a ratio of total functional OH groups to total functional COOH groups of from 1.05:1 to 1.15:1.
Claim 2
Dependent Claim
18 words
The article of claim 2 in which dipropylene glycol is the only diol entering into the reaction product.