GB729487A - Process for the production of polyester artificial resins - Google Patents

Abstract

Synthetic resins are prepared by heating a compound containing p at least two oxacyclobutane rings per molecule with a compound containing at least two carboxyl groups per molecule. The carboxyl groups may be present as acid chloride or anhydride groups. Oxacyclobutane compounds may be prepared by heating pentaerythritol dichlorhydrin with alcholic alkali producing 2.6-dioxaspiro[3,3]heptane of the formula <FORM:0729487/IV (a)/1> and <FORM:0729487/IV (a)/2> or by the process of Specification 729,459, [Group IV (b)]. Furthermore compounds with a single oxacyclobutane ring only, e.g. 3-methylol-3-chloromethyl oxacyclobutane, may be polymerized alone or in admixture and with the aid of Friedel-Craft catalysts or alkalies or bases to produce linear polyethers, e.g. <FORM:0729487/IV (a)/3> from which HCl may be split by treatment with alcoholic alkali to yield a polyether containing a plurality of oxacyclobutane rings in the chain together with residual methylol and chloromethyl groups. If the 3-methylol-3-chlormethyl oxacyclobutane is co-polymerized with a di- or polyoxacyclobutane compound the reaction should be terminated before insoluble, cross-linked resins are produced. Suitable polycarboxylic acids or derivatives are malonic, maleic, succinic, adipic, sebacic or carboxy-terminated polyesters or polyamides. The condensation may be accelerated by use of catalysts, e.g. BF3, AlCl3, ZnCl2, piperidine, inorganic alkalies, p-toluene sulphonic acid, sulphuric acid or a half ester thereof. The products may be used as casting resins, adhesives, cements or coatings. In the examples 2.6-dioxaspiro[3,3] heptane is melted together with (1) phthalic acid anhydride; (2) a polyester from glycerine and excess phthalic acid; (3) and (4) maleic acid anhydride; (5) adipic acid anhydride with p-toluene sulphonic acid as catalyst; (6) and (7) adipic acid; (8) terephthalic acid chloride; (10) a linseed oil-maleic acid adduct. In example (9) the residue left after distillation of the product obtained by treating pentaerythritol dichlorhydrin with alcoholic KOH is condensed with phthalic acid. In example (11) 3-methylol-3-chlormethyloxacyclobutane is polymerized with BF3, AlCl3 or FeCl3 and the polyether produced heated with alcoholic KOH to form oxacyclobutane rings in the chain. The resulting polymer is melted with phthalic anhydride; (12) the polymer of example (11) is heated with maleic acid anhydride; (13) and (16) the polymer of example (11) is heated with piperidine to induce some cross-linking and the product heated with maleic or phthalic anhydride. In example (14) 3-methylol-3-chlormethyl oxacyclobutane is copolymerized with 3-methylol-3-ethoxymethyl oxacyclobutane using BF3, SnCl4 or FeCl3 as catalyst. The product is treated with alcoholic KOH and the resulting oxacyclobutane ring-containing polymer melted with maleic or phthalic acid anhydride. Examples (15) and (17) are similar.ALSO:By the treatment of pentaerythritol dihalohydrin with alcoholic alkali or alkali metal alcoholate, compounds are formed of the formul <FORM:0729487/IV (b)/1> and <FORM:0729487/IV (b)/2> in which R is OH, Cl, Br, <FORM:0729487/IV (b)/3> or the residue of the alcohol used in the reaction. In example 9, pentaerythritol dichlorhydrin is refluxed with a solution of KOH in absolute alcohol. The product is filtered, the filtrate dissolved in ether, dried with sodium sulphate, freed from ether, sublimed and distilled in vacuo. Dioxaspiroheptane distils first, and then a fraction containing 3-methylol-3-chlormethyl-oxacyclobutane mixed with <FORM:0729487/IV (b)/4> Examples 11 and 14 are similar and describe formation of <FORM:0729487/IV (b)/5> and also of <FORM:0729487/IV (b)/6> Specification 729,459 is referred to.