Patent GB-965659-A (GB)
Title: Aqueous coating compositions containing aminoplast and alkyd resin condensates
IPC: C08G63/91
Filed: 1960-10-10
Abstract: A curable aqueous coating composition contains a mixture of (a) 1-50% by weight of water-soluble aminoplast condensate and (b) 99-50% of a salt of 2-(dimethylamino)-ethanol; 3-(dimethylamino)-propanol-2;2-(diethylamino)-ethanol; 3-(diethylamino)-propanol-2; or 3-(diethylamino)-propanol-1 with an alkyd resin of acid number 20-35 derived from (i) at least one dicarboxylic acid of 4-10 carbon atoms or ester thereof, e.g. oils, (ii) at least one aliphatic monocarboxylic acid, and (iii) a polyhydric alcohol with 2-10 carbon atoms and 2-6 hydroxyl groups. Suitable ingredients for the alkyd resin are:-trimellitic, o-iso- or tere-phthalic, pyromelletic, succinic, glutaric, adipic or sebacic acid or anhydride; ethylene glycol, diethylene glycol, glycerol, pentaerythritol, sorbitol, inositol, trimethylolethane, trimethylol propane, tetramethylolcyclohexanol, di- or poly-pentaerythritol; caprylic, pelargonic, capric, lauric, myristic, palmitic, oleic, linoleic, stearic, linolenic or ricinoleic acid, coconut oil or palm oil fatty acids, or fatty acids obtained by hydrogenation of acids from oils or fats. Optional ingredients for the a small proportion of alcohol containing at least 3 hydroxy groups, unsaturated acids, e.g. maleic, fumaric, or maleic anhydride adducts of abietic, ricinoleic or cleostearic acid, and aromatic monoboric acids, e.g. benzoic, toluic or p-tert-butyl benzoic acid.  The amine salt may be prepared with or without the acid of a water soluble organic liquid which is a solvent for the alkyd resin and for the salt, e.g. butoxyethanol, ethoxyethoxyethanol, butoxyethoxyethanol, propoxyethoxyethanol, ethoxyethanol, dimethylsulfone, dimethylsulfonide or t-butanol.  The polyester with or without the coupling agent and with or without an inert solvent, e.g. xylene, benzene or toluene is simply mixed with the amine to form the salt.  Suitable water-soluble aminoplasts are the methylated formaldehyde condensate of urea, N,N1-ethyleneurea, melamine, benzoguanamine, acetoguanamine, N,N1-dimethylmelamine, or a triazinone of formula:- <FORM:0965659/C3/1> in which R is 2-hydroxyethyl, 2-methyl-2-hydroxyethyl, or alkyl of 1-4 carbon atoms; and R1 is H, or methoxymethyl, at least one R1 being methoxymethyl.  In examples (1) An alkyd is formed from lauric acid, propylene glycol, pentaerythritol, and phthalic anhydride, in xylol, cooled to about 100 DEG C., mixed with butoxyethanol and then stirred with dimethylaminoethanol. The salt is mixed with dimethoxymethyltrimethylolmelamine, TiO2 and water to produce a sprayable enamel.  (2) The alkyd is formed from dehydrated castor oil, pentaerythritol, phthalic anhydride and propylene glycol with the acid of sodium methylate and xylol. A salt is formed with dimethylaminoethanol in butoxyethanol and the salt used to form a baking enamel as in Example 1.  In Example (3), the alkyd is prepared from cottonseed oil fatty acid, glycerine, and phthalic anhydride and salts are formed from (a) 3-(dimethylamino)-propanol-2 in dimethyl sulphone, (b) 3-(dimethylamino)-propanol-2 in dimethyl sulphoxide, (c) 2-(dimethylamino)-ethanol in propoxyethoxyethanol.  (d) 3-(diethylamino)-propanol-1 in ethoxyethoxyethanol.  Each of these salts was then mixed with methoxymethyl trimethylol melamine, red lead and water to form curable coating compositions.  The compositions are also useful as pigment binders in print and pigment-dyeing of textiles, for bonding fibres in non-woven webs or for transparentising of paper.