Patent GB-642414-A (GB)
Title: Improvements in and relating to modified rosin esters and compositions containing them
IPC: C09F1/00
Filed: 1947-07-21
Abstract: Modified rosin esters are prepared by reacting at between 200 DEG and 300 DEG  C., a rosin ester of a polyhydric alcohol containing the conjugated unsaturation of abietic acid with an unsaturated alcohol ester of either (a) an alpha unsaturated alpha beta dicarboxylic acid, or (b) a saturated dicarboxylic acid.  The reaction is preferably carried out in two stages, first at 200-250 DEG  C. and when a preliminary reaction is over, at 250-300 DEG  C.  Esters of allyl, crotyl, propargyl and butenyl alcohols are suitable, preferably allyl and di-allyl phthalates, succinates, maleates, and fumarates.  The products may be copolymerized with styrene, methyl methacrylate, or vinyl acetate, and the copolymers made into drying oils to form varnishes, or they may be blended with urea-, phenol-, or melamine-formaldehyde resins cellulose derivatives, or methyl methacrylate, acrylate, vinylidene chloride resins or polyvinyl alcohol.  The products may be cooked into drying oils to form varnish bases, which may be thinned with mineral spirits, and driers added. In an example (1) glycerol abietate and diallyl maleate are heated and the temperature increased slowly from 200-300 DEG  C.  The product is dissolved in heated linseed oil (previously treated to produce conjugated unsaturation).  The mixture is dissolved in mineral spirits and lead and cobalt naphthenates added. Alternatively a lacquer is obtained by dissolving the resin in a mixture of rosin, nitrocellulose, xylol, butyl-, ethyl-, and amyl acetates, and octyl alcohol.  The resin is also soluble in esters, ketones, hydrocarbons, chlorinated hydrocarbons, glycol ethers, nitropropane, and butanol.  The product of a similar example (2) is saponified with sodium hydroxide.  Further examples describe heating together mixtures of (3) pentaerythrityl abietate and diallyl maleate; (4) pentaerythrityl abietate and diallyl fumarate; (5) ester gum and diallyl fumarate; (6) ester gum and diallyl chloromaleate; (7) ester gum and diallyl itaconate; (8) ester gum and diallyl citraconate; (9) the reaction product of glycerol and rosin and monoallyl maleate; (10) the reaction product of rosin and pentaerythritol and monoallyl maleate; (11) the reaction product of tri-hydroxymethyl-amino-methane and rosin and monoallyl maleate; (12) the reaction product of rosin and glycerol and monoallyl citracontate; (13) ester gum, glycerol, and monomethallyl maleate. Examples using esters of saturated polycarboxylic acids describe reacting mixtures of (14) and (15) glyceryl tri-abietate and diallyl phthalate; (16) pentaerythrityl tetra-abietate and diallyl phthalate; (17) pentaerythrityl tetra-abietate and diallyl succinate; (18) glyceryl tri-abietate and diallyl oxalate; (19) glyceryl tri-abietate and diallyl adipate; (20) glyceryl tri-abietate and diallyl succinate; (21) glyceryl diabietate and monoallyl phthalate; (22) pentaerythrityl triabietate and monomethallyl phthalate; (23) tri-hydroxy methylamine methane triabietate and monomethallyl succinate. Varnish bases are described in further examples, in which the product obtained from a resin ester and an unsaturated alcohol ester is afterwards heated with drying oils.  Materials employed are, in examples (24) and (25) rosin glyceride, diallyl maleate, and linseed oil; (26) pentaerythritol tetra-abietate, diallyl fumarate, linseed oil, and china-wood oil; (27) glycerol diabietate, monoallyl maleate and raw tung oil; (28) ester gum, glycerol, monomethallyl maleate, and dehydrated castor oil; (29) glyceryl abietate, diallyl maleate, and alkali-refined linseed oil; (30) the resin of (23) and linseed oil; (31) ester gum, diallyl phthalate, and linseed oil; (32) pentaerythrityl abietate, diallyl phthalate, and linseed oil.  The base is in each case thinned with mineral spirits and lead and cobalt naphenate driers are added.