Patent GB-1016076-A (GB)
Title: Unsaturated polyester resins
IPC: C08G63/553
Filed: 1962-09-05
Abstract: An oxygen-convertible unsaturated polyester having an acid number below about 60 is the reaction product of (a) an unsaturated polycarboxylic acid; (b) a polyhydric alcohol; and (c) a monohydric cyclic acetal having five carbon atoms in its cyclic structure.  The acetal is a condensation product of (i) a hydrocarbyl or halohydrocarbyl aldehyde (e.g. formaldehyde or a compound yielding it, acetaldehyde, butyraldehyde, heptoic aldehyde, nitroaldehyde, benzaldehyde, tolualdehyde, chloral or bromal); and (ii) a trihydric aliphatic straight-chain alcohol of 3-6 carbon atoms having a pair of vicinal hydroxy groups, one of which is primary and the other of which is secondary (e.g. glycerine or 1,2,6-hexanetriol).  Specified unsaturated polycarboxylic acids are maleic, chloromaleic, fumaric, itaconic, mesaconic and citraconic acids and these may be used in admixture with saturated polycarboxylic acids (e.g. phthalic, isophthalic, chlorinated phthalic, tetrahydrophthalic, adipic, succinic or azelaic acids).  Specified polyhydric alcohols for component (h) are polyoxyalkylene glycols (e.g. propylene glycerol, polypropyltylene glycols (e.g. diethylene glycol), 2-butene-1,4-diol, glycerine, trimethylolpropane, trimethylol ethane, trimethylol butane or pentaerythritol.  The polyesters may be further modified with dicyclopentadiene (see Specification 1,016,077), monocarboxylic acids, an alcohol of formula <FORM:1016076/C3/1> or 2-ethyl hexanol. Polyesterification is effected by heating the reactants in the presence of a small amount of an azeotroping liquid and then, possibly, adding p-quinone or a mixture thereof with a solution of acetamidine hydrochloride, as an inhibitor. Coating compositions are made by dissolving the polyesters in an organic solvent (e.g. toluene, xylene, butamol, ethanol, aromatic naphtha, ethylene glycol monomethyl ether acetide, or mixtures thereof) and/or an unsaturated monomer and adding a cobalt salt (e.g. the octoate), possibly in admixture with lead, manganese or zirconium salts (e.g. zirconium naphthenate) or a peroxidic, azo or ozonide catalyst.  Specified monomers are styrene, alpha-methyl styrene, vinyl toluene, divinyl benzene, the lower alkyl acrylates, crotonates or methacrylates, glycol dimethacrylates, diallyl phthalate, diallyl glycollate, vinyl acetate, vinyl butyrate, diallyl ether, vinyl allyl ether, methyl vinyl ether and triallyl cyanerate.  In examples (14) a coating composition comprises the unsaturated polyester, styrene, bentonite, magnesium silicate, dimethylsilicone (antifoam), cobalt octoate and M.E.K. peroxide; (17) a wood-filler comprises the unsaturated polyester, ethylene glycol monomethyl ether acetate, aromatic naphtha, silica, asbestine, burnt umber, bone black, Van Dyke brown, raw sienna, burnt sienna, carbon black, cobalt octoate and zirconium naphthenate; (19) a paint comprises the unsaturated polyester, xylene, ethanol, titanium dioxide, magnesium silicate, calcium carbonate, clay, silicon aerogel, coconut oil modified alkyd, methyl ethyl ketoxime (anti-skin agent) and cobalt octoate-the paint may also include diallyl phthalate and M.E.K. peroxide.ALSO:Monohydric cyclic acetals having the formula <FORM:1016076/C2/1> where R is hydrogen or a hydrocarbon or halohydrocarbon group and n is 0-3 are made by reacting (a) a trihydric alcohol having a primary hydroxyl group next to a secondary hydroxyl group (e.g. glycerine or 1,2,6-hexanetriol) with (b) an aldehyde (e.g. formaldehyde, paraformaldehyde, trioxymethylene, chloral, bromal, butyraldehyde, heptoic aldehyde, benzaldehyde, valeraldehyde or tolualdehyde).  The reaction may be effected in the presence of maleic anhydride (or a catalyst) and xylene or toluene (as azeotroping solvents).