Patent GB-810557-A (GB)
Title: Plasticisers for cellulose derivatives
Inventor: KING FREDERICK ERNEST
IPC: C08K5/103
Filed: 1955-07-19
Abstract: Carboxylic acid esters of cyclohexanol derivatives, containing a pair of methylol groups attached to an ortho carbon atom of the cyclohexanol ring, are used as plasticisers for organic substitution derivatives of cellulose.  The cyclohexanol derivative to be esterified preferably contains a pair of methylol groups attached to each ortho carbon atom, and all the hydroxyl groups are preferably esterified with the carboxylic acid to give compounds such as the penta-acetate of 2 : 2 : 6 : 6-tetramethylol cyclohexanol.  The cyclohexanol derivative to be esterified may be further substituted, but preferably only by methyl groups, and it is preferred that not more than two methyl groups should be present.  Thus the penta-acetates of 2 : 2 : 6 : 6 - tetramethylol - 3 : 4 - dimethylcyclohexanol and 2 : 2 : 6 : 6-tetramethylol - 3 : 5 - dimethylcyclohexanol and the triacetate of 2-methyl-6 : 6-dimethylol cyclohexanol and the corresponding 4-methyl derivative may be used. The carboxylic acid is preferably a fatty acid containing 2-4 carbon atoms, although dicarboxylic acids, e.g. oxalic acid or maleic acid, giving products containing cyclic ester groups, may be used.  The cellulose derivatives may be cellulose acetates, including acetates of higher acetyl value, e.g. 58 to 62.5 per cent (expressed as acetic acid), and other esters derived from fatty acids containing 2-4 carbon atoms, and cellulose ethers such as ethyl cellulose and benzyl cellulose. Other plasticisers, e.g. dimethyl phthalate and triacetin, and phosphate plasticisers, e.g. triphenyl phosphate, tricresyl phosphate and trichlorethyl phosphate, which give improved fire-resistance, may also be added to the composition, which may be cast into films or compression-moulded into discs.  The Provisional Specification describes the use of the plasticisers in cellulose nitrate compositions.ALSO:The penta - acetate of 2 : 2 : 6 : 6 - tetramethylolcyclohexanol is prepared (a) by heating 2 : 2 : 6 : 6 - tetramethylolcyclohexanol with acetic anhydride in a stream of hydrogen chloride for 6 hours, cutting off the current of hydrogen chloride, adding pyridine and then adding acetyl chloride while refluxing until no more hydrogen chloride is evolved, the product then being distilled first at atmospheric pressure and then under 2 mm. pressure, or (b) by refluxing 2 : 2 : 6 : 6-tetramethylolcyclohexanol for 7 hours with an excess of acetic anhydride, distilling off the residual acetic anhydride at atmospheric pressure and then reducing the pressure to 2 mm. and collecting the fraction distilling at 220-225 DEG  C.  The product may be dissolved in and recrystallized from ether.  The pentacetates of 2 : 2 : 6 : 6-tetramethylol cyclohexanol having up to two methyl groups substituted in the ring, e.g. of 2 : 2 : 6 : 6-tetramethylol-3 : 4-dimethylcyclohexanol and 2 : 2 : 6 : 6 - tetramethylol-3 : 5 - dimethylcyclohexanol, and the triacetates of 2-methyl-6 : 6-dimethylolcyclohexanol and 4-methyl-6 : 6-dimethylolcyclohexanol, may be prepared by the same method. Reference is made also to the esterification of the cyclohexanol derivatives with carboxylic acids other than acetic acids to give, for example, propionyl derivatives and mixed acetyl and propionyl derivatives, and to the use of dicarboxylic acids, e.g. oxalic acid or maleic acid, to give products containing cyclic ester groups.