Patent GB-305965-A (GB)
IPC: C08G63/127
Abstract: 305,965. Imperial Chemical Industries, Ltd., Hill, R.., and Walker, E. E. Nov. 11, 1927. Samples furnished. Ester condensation and polymerization products.-Synthetic resins are obtained by condensing a polybasic acid or its anhydride with a plurality of alcohols, at least one of which is di- or polyhydric, products of low acid value and high solubility being obtained if a mono- or dihydric alcohol is used. The term " mono- or dihydric alcohol " embraces not only simple alcohols, such as methyl alcohol, benzyl alcohol, cyclohexanol, and ethylene- or trimethyleneglycol, but also derivatives of polyhydric alcohols in which all but one, or all but two, of the alcoholic groups have been converted into ether or ester groups, e.g. glycol monoalkyl ethers and monoacetate, mono- and di-acetin, chlorhydrins of glycol and glycerol, partly acylated mannitol, and derivatives of glucose such as partly acylated methyl glucoside. The process may be conducted by mixing phthalic anhydride, for example, with a polyhydric alcohol and another alcohol or alcohols, heating the mixture until the more volatile alcohol has reacted, and then continuing the reaction at a higher temperature. Alternatively, one alcohol (preferably the more volatile one) may be caused to react with an excess of phthalic anhydride first, and the other alcohol may then be added. A modified procedure consists in reacting glycerol with a semi-ester of phthalic acid, and a further modification, which is not applicable when one of the alcohols is monohydric, consists in preparing two resins, e.g. a glycerol-phthalic anhydride resin and a glycol-phthalic anhydride resin, and melting them together. Monobasic acids, such as butyric or stearic acid or the acids of linseed, castor, or tung oil, may be substituted for part of the polybasic acid or its anhydride. The products are particularly suitable for lacquers, but they may be hardened by prolonged heating at 80‹-100‹ C. followed by heating at a higher temperature, and may be used also, admixed with fillers, as moulding powders. In example 1, a mixture of phthalic anhydride, glycerol, and ethylene glycol is heated under a short air-cooled reflux condenser, the temperature being raised, with stirring, first to 100‹ C., then to 180‹-190‹ C., and finally to 200‹-210‹ C. A stream of carbon dioxide is passed through the mixture in the later stages to assist in removing the water. The product is a brittle soluble resin of low acid value. In example 2, resins are prepared, by processes similar to that of example 1, from phthalic anhydride and ethylene glycol and from phthalic anhydride and glycerol, and equal parts of these resins are heated and stirred together at 210‹ C. In example 3, a mixture of acid butyl phthalate and glycerol is heated to 200‹-210‹ C. In example 4, a mixture of butyl alcohol and phthalic anhydride is heated to 200‹-210‹ C., whereafter the mass is allowed to cool, glycerol is added, and the temperature is raised again to 185‹-195‹ C. In example 5, a mixture of phthalic anhydride, cyclohexanol, and glycerol is heated to 170‹ C. and then to 185‹-195‹ C. The product is soluble in ethyl acetate, amyl acetate, and other ester solvents, and may be used as a constituent of nitrocellulose lacquers. In the final example, a mixture of phthalic anhydride, glycerol, and ethylene glycol is heated in an open vessel to 185‹ C. and fatty acids from linseed oil are then slowly added. After further heating at 185‹ C., the temperature is raised to 230‹- 240‹ C. and maintained in that range for some time. The product is soluble in acetone and benzene-alcohol and may be used as a lacquer. Reference has been directed by the Comptroller to Specification 299.424.