| 摘要 |
Thixotropic gelled resins are prepared by heating at temperatures greater than 220 DEG C. an ester of allyl alcohol and of a monocarboxylic acid which is saturated or contains one olefinic double bond or of a saturated aliphatic or aromatic dicarboxylic acid with a drying oil, a semi-drying oil or a drying alkyd resin from 10 to 30 hours when a reversible gel is obtained. Allyl esters specified are the acetate, benzoate, propionate, butyrate, heptanoate, acrylate, crotonate, undecylenate, and the allyl esters of fatty acids. Diallyl esters specified are the phthalate, isophthalate, malonate, succinate and adipate. Drying oils mentioned are linseed oil, soya-bean oil, cotton-seed oil and the esters of drying fatty acids used in the form of stand oils, of styrenated oils or of oxidized oils. Drying alkyd resins are obtained by condensation of polyhydric alcohols with polycarboxylic acids and the product modified by drying fatty acids or oils. Solvents for the resin include aliphatic hydrocarbons, e.g. white spirit. A catalyst, e.g. litharge or calcium acetate may be added to the reaction medium. In Example 1 linseed oil is added to diallyl phthalate and heated to 260 DEG C. for 24 hours when a gel is produced. After a further 15 minutes, the product is cooled and diluted to 50% with white spirit yielding a soft thixotropic gel. The resins can be used in the manufacture of paints, varnishes and coating compositions. Two paint compositions are described: a matt paint containing the thixotropic resin of Claim 1, rutile, calcium carbonate, lead naphthenate, cobalt naphthenate, hydroquinone and white spirit and a gloss paint of same composition as the matt except there is no calcium carbonate and amyl phenol instead of hydroquinone is used as the anti-skinning agent. |
