Patent GB-969042-A (GB)
Title: Esters containing more than one oxetane group, their production and their uses
Inventor: STARK BERNARD PETER
IPC: C08G63/668
Filed: 1961-10-11
Abstract: The invention comprises compounds of formula: <FORM:0969042/C1/1> wherein, n is 2, 3 or 4, Z is the residue of an organic carboxylic acid originally having n carboxyl groups but free from epoxide and other functional groups after removal of hydroxyl groups, and R is an alkyl, preferably methyl or ethyl groups, which are prepared by heating a hydroxy-oxetane: <FORM:0969042/C1/2> with an ester [R1O-]nZ in which R1 is a hydrocarbon residue in the presence of a transesterification catalyst e.g. tetrabutyl titanate, zinc or cadmium acetate, dibutyl tin oxide, alkali metals and their hydroxides and alkoxides, quaternary ammonium hydroxides and quaternary ammonium hydroxide containing ionexchange resins.  A solvent such as dioxan, toluene, or chlorine containing aromatic hydrocarbons may be used and the alcohol formed removed by distillation, and the products are liquid or readily fusible compounds which may be hardened e.g. by treatment with a dicarboxylic anhydride to clean light-coloured resins.  The preferred oxetane of Formula II is 3-methyl- or 3-ethyl -3- hydroxymethyl -1- oxacyclobutane, and methyl, ethyl, propyl or butyl esters of oxalic, malonic, succinic, glutaric, adipic, sebacic, phthalic, isophthalic, terephthalic, maleic, itaconic, citraconic, citric, tricarballylic, tetrahydrophthalic, methylendomethylene-tetrahydro. phthalic, hexahydrophthalic, pyromellitic acids and dimerised or trimerised unsaturated long-chain fatty acids are mentioned. A bye-product: <FORM:0969042/C1/3> may be present if the reaction does not proceed to completion. The esters may be polymerized with Friedel Crafts catalysts or cross-linked and hardened by bis- or polyfunctional compounds, and may be used in resinous compositions (see Division C3).ALSO:Compositions comprising esters of formula <FORM:0969042/C3/1> wherein n is 2, 3 or 4, Z is the residue of a carboxylic acid originally with n carboxylic groups and free from epoxide groups or other functional groups after removal of hydroxyl groups, and R is an alkyl preferably methyl or ethyl groups (see Division C2) may be polymerized with Friedel Crafts catalysts or cross-linked and hardened by bis- or polyfunctional compounds such as phthalic acid, methylendo-methylene-tetrahydrophthalic anhydrides, dodecenylsuccinic, hexahydrophthalic, hexachloroendomethylene-tetrahydrophthalic, endomethylene -tetrahydrophthalic, maleic, succinic, or phthalic anhydrides, or adipic acid or mixtures thereof.  The preferred esters are prepared from 3-methyl or 3-ethyl -3- hydroxymethyl -1- oxacyclobutane and esters of acids such as oxalic, malonic succinic, glutaric, adipic, sebacic, phthalic, isophthalic, terephthalic, maleic, itaconic, citraconic, citric, tricarballylic, tetrahydrophthalic, methylendomethylene - tetrahydrophthalic, hexahydrophthalic, and pyromellitic acids and dimerised or trimerised unsaturated long-chain fatty acids. Accelerators such as t-amines and/or toluene-p-sulphonic acid, a bye-product of the preparation of the esters of formula <FORM:0969042/C3/2> hydroxy-oxetanes or polyhydric alcohols, monoepoxides e.g. 2,6-dioxaspiro (3,3) heptane, the reaction products of alkali metal salts of bisphenols with 3-halomethyl -3- alkyl -1- oxacyclobutanes, di- or polyglycidyl ethers of di- or poly-alcohols or phenols e.g. bis (4-hydroxy-phenyl)-dimethylmethane, polyglycidyl esters of polycarboxylic acids, or aminopolyepoxides may also be present in the hardenable compositions, together with fillers, plasticisers and colouring agents.  The compositions may be in a filled or unfilled state and used as solutions or emulsions in textile auxiliaries, laminating resins, varnishes, lacquers, dipping or casting resins, moulding compositions or adhesives.  Examples describe the hardening of esters prepared from diethyl adipate and 3-ethyl -3- hydroxymethyl -1-oxacyclobutane with maleic anhydrides, or a polyglycidyl ether derived from epichlorohydrin and bis (4-hydroxyphenyl) dimethylmethane; diethyl isophthalate and 2-ethyl -3- hydroxy-methyl -1- oxacyclobutane with maleic anhydride or phthalic anhydride; di -npropyl isophthalate and 3-ethyl-3 hydroxymethyl -1- oxacyclobutane with phthalic anhydride; diethylphthalate and 3-ethyl -3- hydroxymethyl -1- oxacyclobutane with hexachloro-endomethylene tetrahydrophthalic anhydride or phthalic anhydride; tetra -npropyl pyromellitate and 3-ethyl -3- hydroxymethyl -1- oxacyclobutane with maleic anhydride; and di -npropyl-D 4-tetrahydrophthalate with 3-ethyl -3- hydroxymethyl -1- oxacyclobutane with phthalic anhydride, to form resins.