Patent GB-731817-A (GB)
Title: Improvements in dihydric alcohols and resins produced therefrom
IPC: C07C45/71
Filed: 1952-02-12
Abstract: Resinous condensation products are formed from dihydric alcohols of the general formula <FORM:0731817/IV (a)/1> wherein R1 represents the methyl or ethyl radical and R represents one of the radicals -CH2CH2-, -CH2CH2CH2-, -CH2CH2 CH2CH2- or CH2CH2OCH2CH2-, by elimination of water between a hydroxyl group of one molecule and a nuclear hydrogen atom of an adjacent molecule.  The condensation products may be prepared by heating the dihydric alcohols to a temperature within the range 130 DEG  to 250 DEG  C.  The resinous condensation products may be further condensed by continued heating under pressure to cause the remaining hydroxy groups to react and form a cross-linked colourless and infusible resin.  In the examples: (1) a resinous condensation product soluble in dimethyl formamide is obtained by heating ethylene - bis - (2 - methoxy - 4 - hydroxymethylphenyl) ether for 1 hour at 175 DEG  C.; (2) a solution of bis-(2-methoxy-4-hydroxymethylphenoxyethyl) ether in dimethyl formamide containing a catalytic quantity of oxalic acid is coated on a rod, dried at 110 DEG  C. and then baked at 160/170 DEG  C. to form a transparent coating; (3) a thermoplastic resin is obtained p  by dissolving ethylene-bis-(2-methoxy-4-hydroxymethylphenyl) ether in water with a small quantity of concentrated hydrochloric acid and the solution is refluxed to form an oil which solidifies on cooling; (4) the product of example (3) is heated under pressure to form an infusible resin; (5) a resinous condensation product is obtained by heating tetramethylene-bis-(2-methoxy - 4 - hydroxymethylphenyl) ether at 175/250 DEG  C. for 2 hours and is dissolved in dimethyl formamide, coated on a glass plate, dried and heated for 1 hour at 130 DEG  C.; (6) bis-(2-methoxy - 4 - hydroxymethylphenoxyethyl) ether is treated as in (5) using a catalytic quantity of oxalic acid in the dimethyl formamide solution, and the final baking is effected under an infra-red lamp; (7) ethylene-bis-(2-ethoxy-4-hydroxymethylphenyl) ether is treated as in (3), and the product is heated under pressure.ALSO:The invention comprises substituted ethers of the general formula <FORM:0731817/IV (b)/1> wherein R1 represents the methyl or ethyl radical and R represents the -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2- or -CH2CH2OCH2CH2- radical.  A typical method for the preparation of the above compounds is by refluxing vanillin, ethylenedibromide or dichloride and aqueous sodium hydroxide to form ethylene divanillin ether or ethylene di-(ethylvanillin) ether of the formula <FORM:0731817/IV (b)/2> wherein R1 has the above significance, and heating the resulting ether with an aluminium alkoxide of the formula Al(OR)3, wherein R represents a lower alkyl radical, in the presence of methyl isobutylcarbinol.  In a similar manner the corresponding ethyl compound is prepared from ethyl vanillin, tetramethylene divanillin ether is prepared using 1,4-dichlorobutane and diethylene glycol divanillin ether is prepared using b ,b 1-dichlorodiethyl ether.  In the examples the following compounds are prepared: ethylene-bis-(2-methoxy-4-hydroxymethylphenyl) ether, tetramethylene - bis - (2-methoxy - 4 - hydroxymethylphenyl) ether, bis-(2 - methoxy - 4 - hydroxymethylphenoxyethyl) ether and ethylene - bis - (2 - ethoxy - 4-hydroxymethylphenyl) ether.