Patent GB-852110-A (GB)
Title: Process for the preparation of esters
IPC: B01J31/02
Filed: 1956-10-08
Abstract: Acid sensitive plastics such as polyvinyl chloride are plasticised by means of esters of monohydric alcohols obtained by reacting the alcohol with a saturated or unsaturated, substituted or unsubstituted, aliphatic, cycloaliphatic or aromatic mono-or polycarboxylic acid or anhydride thereof in the presence of an organic titanium catalyst of the kind described in Specification 851,600 (see Group IV(b)).  The catalyst may be retained in the crude ester and thereby stabilise the plasticised resin. Extensive lists of alcohols and acids from which the esters may be derived are given and contain compounds having the following substituent groups or atoms:- Cl, Br CN, OH, nitro-, methoxy and ethoxy.  Specification 733,224 is referred to.ALSO:Esters are prepared by reacting at an elevated temperature in the liquid phase and in the absence of any polyhydric alcohols, a carboxylic acid or an anhydride thereof with a monohydric alcohol in the presence of a catalytic amount of one or more compounds of the general formula MX4 in which M is titanium or zirconium and X is a hydroxyl, alkoxy, aryoxy, acyloxy, hydroxy alkyloxy, hydroxy polyalkoxy or amino alkoxy group or a chlorine or bromine atom, at least one X being an organic radical specified above having 1 to 18 carbon atoms, and removing the water of esterification from the reaction mixture substantially as rapidly as it is formed. The catalysts are Ti and Zr esters, acylates and chelates.  Typical of many which are specified, in addition to those used in the examples, are tetra-methyl and -octadecyl titanates; hydroxy titaniumacetate, -hexanoate and -castor oil acylate; iso-propoxy titanium-octanoate and -tall oil acylate; tetra polyethylene glycol titanate; tetra triethanolamine titanate N-oleate; the corresponding zirconium compounds; certain zirconium and titanium monohalo trialkyl and dihalo dialkyl esters.  The catalyst may be used in amounts of 0,01 to 10% by weight of the acid.  Reduced or elevated pressures may be used.  In examples, (1) mono- or di-esters of 2-ethyl hexanol with phthalic acid are prepared from the alcohol and acid anhydride under reflux conditions using the following catalysts : tetra isopropyl titanate, tetra stearyl titanate, tetra phenyl titanate, tetra octylene glycol titanate, tetra triethanolamine titanate, hydroxy titanium stearate, hydroxy titanium coconut acylate, di-isopropoxy titanium dichloride and tetra ethyl zirconate; (2) phthalic anhyride is refluxed with excess octanol-2 using tetra isopropyl titanate, or in comparative experiments in the absence of catalyst or in the presence of toluene sulphonic acid.  Numerous other monohydric alcohols are specified including saturated and unsaturated aliphatic alcohols and araliphatic alcohols, some containing chlorine, CN, Br, NO2 or methoxy substituents. Many additional examples of acids and anhydrides are also given including aliphatic saturated and unsaturated mono- and polycarboxylic acids, some containing chlorine, bromine, CN, hydroxyl or phenyl substituents, saturated and unsaturated cycloaliphatic mono- and poly-carboxylic acids and aromatic mono- and poly-carboxylic acids, some containing chlorine, bromine, hydroxy, nitro, methoxy or alkyl substituents.  The esters are plasticisers for acid sensitive polymers.  (see Group IV (a)). Specification 733,224 also is referred to.