Patent GB-859773-A (GB)
Title: Method for production of sulfur-containing carboxylic-ester adducts and products so-called
IPC: C08K5/37
Filed: 1957-05-01
Abstract: Poly vinyl chloride is plasticized by means of a sulphur-containing carboxylic ester adduct obtainable by reacting a compound of the general formula:  <FORM:0859773/IV(a)/1> with a compound R 1SH wherein R represents a C1-14 alkyl group, an alkoxyalkyl group containing 2-14 carbon atoms, an aralkyl group containing 7-14 carbon atoms or a cycloalkyl, cycloalkyl-alkyl or alkyl-cycloalkyl group containing 3-14 carbon atoms and R1 represents hydrogen or a C1-18 alkyl group, an aryl group containing 6-10 carbon atoms, an aralkyl or alkaryl group containing 7-20 carbon atoms, a hydroxy-alkyl hydroxy alkoxy alkyl, poly hydroxy alkyl or hydroxy-cycloalkyl group containing 2-12 carbon atoms, a mercapto-alkyl group containing 2-12 carbon atoms or an alkoxy carbonyl alkyl group in which the alkoxy portion contains 1-8 carbon atoms and the alkyl portion contains 1-6 carbon atoms.  Numerous examples of the adducts are given (see Group IV(b)) The transferred adducts are those in which R represents methyl.  When R 1SH is a mercaptan the adduct consists primarily of a compound of the structure:  <FORM:0859773/IV(a)/2> with some <FORM:0859773/IV(a)/3> When R 1SH is H2S the principal product is <FORM:0859773/IV(a)/4> with some <FORM:0859773/IV(a)/5> The adducts may be used by milling with the polyvinyl chloride in admixture with minor amounts of stearic acid and tribasic lead sulphate at elevated temperatures.ALSO:The invention comprises sulphur-containing carboxylic ester adducts of a compound (a) having the general formula:  <FORM:0859773/IV(b)/1> wherein R represents an alkyl group containing 1-14 carbon atoms, an alkoxyalkyl group containing 2-14 carbon atoms, an aralkyl group containing 7-14 carbon atoms or a cycloalkyl, cycloalkyl-alkyl or alkyl-cyclo alkyl group containing 3-14 carbon atoms, and a compound (b) of the general formula R1SH wherein R1 represents hydrogen, an alkyl group containing 1-18 carbon atoms, an aryl group containing 6-10 carbon atoms, an aralkyl or alkaryl group containing 7-20 carbon atoms, a hydroxy alkyl, hydroxy alkoxy alkyl, polyhydroxy alkyl or hydroxycycloalkyl group containing 2-12 carbon atoms, a mercapto alkyl group containing 2-12 carbon atoms or an alkoxy carbonyl alkyl group in which the alkoxy portion contains 1-8 carbon atoms and the alkyl portion contains 1-6 carbon atoms.  The adducts may be prepared by reacting if necessary with the aid of heat, a compound A with a compound B in the presence of a catalyst which is a strongly alkaline compound such as an alkali metal oxide, hydroxide, hydride, amide or alkoxide, an amine or a quaternary ammonium hydroxide or alkoxide, many examples being given; free radical catalysts such as an organic peroxide or azo diiso butyronitrile; and ultra violet light alone or with a free radical catalyst.  Temperatures are generally from about 20 to 200 DEG  C. and atmospheric or elevated pressures may be used.  When an organic mercaptan is used as reagent, the adduct is a thio ether of the adipic acid diester resulting from addition of the mercaptan to the double bond of the ester, which may, in some cases, react with a further mole of compound A.  Hydrogen sulphide yields a mercaptan of the initial ester or a thio ether resulting from addition of one mole of H2S to the double bonds of 2 moles of the ester; the latter predominates when about equimolar proportion of reagents are used. Those products wherein the R group is methyl or ethyl can be converted into esters having other values of R by transesterification of those products with an alcohol R11 OH in which R11 represents an alkyl group containing 3-14 carbon atoms, an alkoxy alkyl group containing 2-14 carbon atoms, an aralkyl group containing 7-14 carbon atoms or a cycloalkyl or cyclo alkyl-alkyl group containing 3-14 carbon atoms, in the presence of a strongly acidic or alkaline esterification catalyst at the reflux temperature of the mixture, whereby at least one R group in the initial adduct is replaced by R11; suitable catalysts are sulphuric acid, lower alkane sulphonic acids, aryl sulphonic acids, sodium or potassium ethoxide or a strongly acidic ion-exchange resin.  Inert solvents may be present. The products may be used as synthetic lubricants, or as plasticisers (see Group IV (a)).  Examples describe typically the preparation of (1) 2 : 5-di (methoxy carbonyl) hexyl mercaptan and bis [2 : 5-di (methoxy carbonyl) hexyl sulphide, and 2 : 5- di (benzyloxycarbonyl) hexyl mercaptan and bis [2 : 5-di (benzyloxy carbonyl) hexyl] sulphide; (2) 2 : 5-di (butoxy carbonyl) hexyl mercaptan and bis [2 : 5- di (butoxy carbonyl) hexyl] sulphide; (5) 2 : 5-bis (methoxy carbonyl) hexyl phenyl sulphide and its condensation product with one mole of dimethyl a -methylene-a 1-methyl adipate; (7) the 1 : 1 adduct of dicyclohexyl-a -methylene-a 1-methyl adipate and octyl thio glycollate; and (12) diethyl a -phenyl thio methyl-a 1-methyl adipate and its conversion by inter-esterification into ethyl octyl a -phenyl thio methyl-a 1-methyl adipate.