Patent GB-1096915-A (GB)
Title: Water-soluble polyesters
Inventor: BASHFORD LESLIE ARTHUR
IPC: C09D155/04
Filed: 1963-09-30
Abstract: Paint compositions comprise as a water-soluble binder the polyester salt of formula (MOOC.R1.COO)xR(OOCR11)y in which x is an integer, y an integer or zero, x+y is at least 4, R is an aliphatic radical of valency (x+y), R1 is a divalent aliphatic radical containing at least one double bond, R11 is a monovalent aliphatic radical containing at least two double bonds and M is a monovalent cation other than hydrogen, which has an acid value in the range 30-100 (see Division C2). The surface coating may be applied by spraying or brushing or by electro-deposition, and the air-drying or stoving stage cures the coating to a film impervious to water and solvents. Curing aids such as soluble salts of cobalt, lead or manganese, or oxides or hydroxides of zinc or aluminium, and calcium, magnesium, strontium and barium may be present.  An example describes the reaction of pentaerythritol with linseed oil fatty acids to form a tetra-ester which is reacted with maleic anhydride and the product neutralized with triethylamine and dissolved in ethylene glycol monobutyl ether. This medium is used to prepare a paint with titanium dioxide, zinc oxide, isobutanol, ethylene glycol monomethyl ether and water and with cobalt and lead octoates as driers.  The paint is suitable for application by brush.ALSO:The invention comprises a polyester salt of formula (MOOC.R1-COO)xR(OOC.R11)y in which x is an integer, y an integer or zero, x + y is at least 4, R is an aliphatic radical of valency (x + y), R1 is a divalent aliphatic radical containing at least one double bond, R11 is a monovalent aliphatic radical containing at least two double bonds, and M is a monovalent cation other than hydrogen, which has an acid value in the range 30-150, and is used as a water-soluble binder for use in paints. The compound is prepared by forming a polyester of formula R(OCOR11)x+y by condensing a polyol with 4 or more hydroxyl groups, e.g. pentaerythritol with monobasic unsaturated aliphatic acids, e.g. those derived from linseed, sunflower, soya bean, tall, safflower, tobacco seed, dehydrated castor, and tung oils, and forming an adduct with the ester and an acid or anhydride containing an a ,b -double bond, e.g. maleic, fumaric, and itaconic acids.  The anhydride ring is opened by water, alcohols, and amines, and the free acid groups converted to salts and sodium, potassium, ammonium or amine cations are mentioned. The products after application as surface coatings are air-dried or stoved to form cross-linked structures or they may be electro-deposited. Curing agents such as salts of cobalt, lead and manganese, or colloidal zinc oxide and aluminium hydroxide, or the oxide and hydroxides of calcium, magnesium, strontium and barium may be used in coating compositions.  An example describes the reaction of pentaerythritol with linseed oil fatty acids to form a tetra-ester which is reacted with maleic anhydride and the product neutralized with triethylamine and dissolved in ethylene glycol monobutyl ether. The medium is used to prepare a paint with titanium dioxide, zinc oxide isobutanol, ethylene glycol monomethyl ether and water and cobalt and lead octoates.