Patent GB-837696-A (GB)
Title: Flame-retardant unsaturated polyester resin compositions
Inventor: WILLIAMS LESLIE
IPC: C08G63/682
Filed: 1956-04-12
Abstract: Antimony alcoholates may be prepared by dissolving antimony trichloride in a 5% excess of the appropriate saturated or unsaturated alcohol together with an inert solvent, e.g. carbon tetrachloride or toluene.  Anhydrous ammonia gas is passed in until excess is present, the temperature being maintained below 25 DEG  C. throughout.  Antimony tri-isopropoxide, tri-alloxide, tri-methallyloxide and tri-crotoxide are mentioned.  When antimony is to be combined with alcohols or glycols with boiling-points above that of isopropanol, the requisite amount of alcohol or glycol may be added to antimony tri-isopropoxide and the liberated isopropanol may be removed by distillation under reduced pressure; in this way ethylene glycol antimonite is prepared by reacting 1 mol. of antimony isopropoxide and 3 mols. of ethylene glycol.  Antimony acylates or mixed acylates/alcoholates may be prepared by mixing appropriate amounts of saturated or unsaturated acid with an antimony alcoholate; e.g. 3 mols. of methacrylic acid may be added to 1 mol. of antimony iso propoxide, and the mixture evaporated under as low a pressure as possible on a water bath at a temperature not exceeding 35 DEG  C., to leave a residue of the antimony triacylate.  Antimony acrylate, methacrylate, crotonate and monoalloxide dimethacrylate are mentioned and the use of hydroxy acids is referred to.  In the first Provisional Specification the following antimony compounds are also mentioned:-triethoxide, tri-butoxide, tri-sec.-but-oxide, triacetate, tripropionate, tributyrate and di-alloxide acrylate.  It is also stated that a preferred method of making the unsaturated alcoholates is to first saturate the unsaturated alcohol with ammonia, and then add the antimony trichloride, as a solution in toluene or xylene, while maintaining an excess of ammonia in the reaction mixture.  In the second Provisional Specification there is discussed a method of introducing chlorine into antimony alcoholates, and/or acylates; this is by making use of chlorine-containing alcohols or phenols, e.g. ethylene chlorohydrin, glycerol dichlorohydrins, trichloroethanol, tri- and pentachlorophenol, so that mixed antimony alcoholates, phenolates and/or acylates are formed.  It is also stated that such mixed compounds, chlorinated or unchlorinated, may be prepared by mixing appropriate proportions of antimony tri-alcoholates, tri-phenolates or tri-acylates.ALSO:Clear, flame-retardant, unsaturated polyester compositions comprise (i) a linear unsaturated polyester which may be dissolved in an ethylenically unsaturated monomer with a terminal methylene group, (ii) an antimony "alkoxide" (as defined below), antimony acylate or antimony "alkoxide"-acylate, and (iii) a chlorine compound which may be present as the polyester, the monomer, or chlorinated paraffin wax, provided that when the chlorine compound is a chlorinated paraffin wax containing at least 50% by weight of chlorine, the antimony compound is not an acylate nor an alkoxide-acylate.  The polyesters (i) may be derived from maleic acid and propylene glycol, with or without adipic or phthalic acids, and the monomers may be styrene, vinyl toluene, divinyl benzene or the allyl esters of phthalic, maleic or diglycollic acids; when the polyester or monomer is chlorinated (iii), there may be used tetrachlorophthalic or hexachloro-endomethylene tetrahydrophthalic acids or anhydrides, or chlorostyrene or diallyl tetrachlorophthalate.  Two preferred methods of combining the antimony compound and the polyester are disclosed: (A) The antimony compound may be ethylenically unsaturated, the term "alkoxide" being defined as including saturated alkoxides, unsaturated alkoxides and glycoxides, and is then co-polymerized with the polyester; e.g. antimony trialloxide, trimethallyl oxide, tricrotoxide, acrylate, methacrylate, crotonate, or monoalloxide dimethacrylate.  (B) The antimony compound may be incorporated into the polyester by esterification; e.g. saturated antimony alkoxides (tri-isopropoxide) or acylates, or the antimony compounds of hydroxy acids or glycols (ethylene glycol), may be used, volatile components such as the propanol being volatilized and non-volatile components such as ethylene glycol being incorporated into the polyester.  When addition polymerization is being used catalysts specified are benzoyl peroxide with or without dimethylaniline or dimethyl p  para-toluidine, and hydroquinone or p-tertiary butyl catechol may be used as inhibitors. Use.-Glass fibre matting or cloth laminates.  In the first Provisional Specification there is discussed the addition of soluble organic derivatives of antimony to polystyrene, acrylic resins and polyester fibre-glass laminates. Apart from the antimony compounds listed above, the following are also mentioned: antimony triethoxide, tributoxide, tri-sec.-butoxide, triacetate, tripropionate, tributyrate and dialloxide acrylate.  In the second Provisional Specification the subject-matter corresponds more closely to that of the Complete Specification but the following alternatives are given. Instead of chlorinated paraffin wax, there may be used chlorinated diphenyl or chlorinated rubber.  And the chlorine may be contained in the antimony compound; thus an unsaturated unchlorinated "alkoxide" or acylate may have introduced into it chlorine containing alkoxide or phenoxide groups derived from ethylene chlorohydrin, glycerol dichlorohydrin, trichloroethanol, tri- and penta-chlorophenol.