Alkylene glycol ether carboxylic ester prodn. - using organo-zirconium cpd. as catalyst and opt. co:catalyst, useful as solvent and plasticiser

摘要

In the prodn. of carboxylic esters (I) of alkylene glycol ethers by reacting alkylene oxides (II) with carboxylic esters (III), the catalyst used contains organo-Zr cpd(s). (IV) of the formula Zr-(R)n (in which n is the valency of Zr and the R substits. independently are 1-4C (ox)alkyl, (ox)aryl, alkaryl with 1-4C alkyl gp(s)., aralkyl with a 1-4C alkylene gp. or a halogen atom but max. 3 halogen atoms are bound to the Zr atom). A cocatalyst (V) may also be used, i.e. a 12C N-alkyl-carbonamide, N-1-4C alkyl-pyrrolidone, benzotriazole or amine of the formula N(R')3 (in which R' is H or a 1-18C hydrocarbyl gp.; 2 R' substits. can form a cyclic hydrocarbyl gp.). Pref. (II) is ethylene oxide (EO) or propylene oxide and (III) has the formula R2-CO-OR3 (in which R2 is H or 1-4C alkyl. R3 is 1-4C alkyl). In (IV), n is 4, the R gps. are the same and are 1-3C (ox)alkyl, (ox)phenyl or benzyl and (V) is a prim., sec. or tert. 1-4C alkylamine. The amt. of (IV) used is 0.05-10 mole-% w.r.t. (II), whilst the (IV)/(V) molar ratio is 0.01-10. The (II)/(III) molar ratio is 1:1-50, reaction temp. 100-250 deg.C and conversion 1-60 wt.%. It is pref. to react EO and ethyl acetate (IIIA) in 1:3-30 molar ratio in the presence of 0.1-5 (0.5-3) mole-% (IV) w.r.t. EO and a (IV)/(V) molar ratio of 0.1-4 at 130-180 deg. C to a conversion of 5-45 (10-25) wt.%. Large amts. of monoadduct (monoalkylene glycol alkyl ether ester) can be obtd. and the conversion is relatively high. (I) are valuable solvents for paints, lacquers, adhesives or printing inks and can also be used as plasticisers.