Patent GB-600618-A (GB)
Title: Improvements in or relating to the manufacture of synthetic resinous condensation products
Filed: 1945-01-31
Abstract: Synthetic resins are prepared by heating an a b -unsaturated aldehyde which does not contain conjugated ethylenic unsaturation and is not itself readily polymerized to produce a resin, or a substance giving rise to such an aldehyde under the reaction-conditions, with an a b -unsaturated dicarboxylic acid, anhydride, ester or non-resinous halogen derivative thereof or substance giving rise thereto under the reaction conditions and then reacting the adduct with a fatty oil, fatty acids derived therefrom and/or a partial ester thereof containing at least one free hydroxyl group, and if necessary an alcohol to complete esterification of any free carboxyl groups. Suitable aldehydes are crotonaldehyde, cinnamic aldehyde, tiglic aldehyde, a b -dimethyl crotonaldehyde.  A substance giving rise to such an aldehyde is acetaldol which by loss of water yields crotonaldehyde.  Suitable acid bodies are maleic, fumaric, glutaconic, citraconic or itaconic acids, ethyl maleate, or chlormaleic acid.  A substance giving rise to such bodies is citric acid which on heating yields a mixture of aconitic, itaconic and citraconic acids.  Suitable alcohols are pentaerythritol, glycerol, ethylene glycol, butyl, allyl, or cetyl alcohol.  The initial reactants are preferably heated with stirring in an inert atmosphere and under conditions permitting removal of water especially at the end of the reaction.  With high boiling reactants an open vessel may be used.  Natural resins, fossil gums or synthetic resins may be added at any stage of the process.  If desired the fatty oil, fatty acid therefrom or mixture thereof may be present during formation of the adduct, esterification being effected subsequently.  An adduct containing a group capable of reacting with an aldehyde, e.g. an adduct from o-hydroxycinnamic aldehyde may be reacted with formaldehyde before esterification.  Aldehydic groups in the adduct may be reacted simultaneously with or subsequent to the adduct formation with phenols, amines, urea, or sulphonamides.  Unsaturated bodies known to be polymerizable, e.g. styrene, di-isobutylene, methyl methacrylate or vinyl acetate may be present during adduct formation or may be copolymerized with the adducts.  The products of the invention may be used as or incorporated in coating compositions which may also include driers, and pigments. Products modified with non-drying oils may be used as plasticizers for other resins.  In examples: (1) crotonaldehyde and maleic anhydride were heated under reflux in carbon dioxide and the resinous product was esterified with a partial glyeryl ester of linseed oil acids.  A solution of the product in white spirit with driers was film forming at normal temperatures; (2) crotonaldehyde, phorone, and maleic anhydride were heated together and the product heated with linseed oil fatty acids and then esterified with glycerol.  Samples have been furnished under Sect. 2 (5) : (1) an adduct is formed from crotonaldehyde and maleic anhydride, is heated with linseed oil fatty acids and is then esterified with glycerol.  The product was thinned with mineral spirits and metallic naphthenate driers were added.  (2) Alkali-refined linseed oil, crotonaldehyde and maleic anhydride were heated together and the product esterified with glycerol, thinned with xylol and mixed with driers.  (3) Crotonaldehyde, phenol and maleicanhydride were heated together.  The product was heated with a partial glyeryl ester of linseed oil acids and then esterified with extra glycrol. The product was thinned with mineral spirits and driers added. (4) Maleic anhydride and 2-ethyl-3-propyl acrolein were heated together, styrene being added during the heating.  The product was heated with a partial glycryl ester of linseed oil fatty acids and then with glycerol.  The product was dissolved in mineral spirits and metallic naphthenate driers were added.  Specifications 517,684 and 600,408 are referred to.