Patent GB-305947-A (GB)
Title: Manufacture of soluble cellulose esters and ether-esters
IPC: C08B3/08
Filed: 1929-02-11
Abstract: 305,947. I. G. Farbenindustrie Akt.- Ges. Feb. 11, 1928, [Convention date]. Addition to 283,181 and 297,766. Cellulose carboxylates; cellulose ethers.-The processes for preparing cellulose higher fatty acid esters of the parent Specifications are modified in the following manners :-(1) employing mixtures of different halides of the higher fatty acids; (2) adding the esterifying-agent in stages, different acid halides being used at the successive stages or the same halide being employed throughout; (3) substituting for the halide of the higher fatty acid, either wholly or in part, a halide of a cyclic substituted fatty acid or of a alicyclic carboxylic acid. When producing soluble mixed esters by operating in stages, the first may be carried out at a temperature below 100‹ C., and the second with a different halide at a temperature above 100‹ C. or at a temperature below 100‹ C., followed by a heating stage to a temperature above 100‹ C. ; in the same way when using a mixture of halides, esterification may be carried out below 100‹ C., and the reaction mixture subsequently heated to above 100‹ C. Similarly, with the use of alicyclic carboxylic and cyclic substituted acid halides there must be heating to some temperature above 100‹ C. in order that the soluble ester may be obtained. The obtaining of the desired solubility in the heating stage is accelerated by the addition of an acid, acid anhydride, acid chloride, a salt of a strong acid with a weak base, or a mixture of these. The products may be worked up into threads, films, lacquers, coating and insulating compositions, and plastic masses; and the soluble esters of the salicyclic carboxylic acids or cyclic substituted fatty acids, although very hard at normal temperature, may be moulded at 50‹ C. without, the aid of a, solvent or softening-agent, although the latter may be employed. The products may be worked up according to the. process of Specification 289,063. The material to be esterified may be untreated cellulose or a cellulose 'derivative such as a cellulose ester or ether, which still contains reactive hydroxyl groups. In examples, linters are added to a heated mixture of pyridine bases, chlorobenzene and phenylacetic acid chloride, and the reaction mixture heated to 115-120‹ C.; cellulose is heated on a steam-bath with chlorobenzene, naphthenic acid chloride and a-picoline, and the resulting insoluble ester converted into a soluble product by heating to 135‹ C.; linters are added to xylene, pyridine, bases, lauryl chloride and phenylacetic acid chloride, the reaction mixture being maintained at 130‹ C. to produce a soluble mixed ester; cellulose is added to a mixture of chlorobenzene, butyric acid chloride, ricinoleic acid chloride and pyridine bases heated to 85- 90‹ C., the insoluble mixed ester first formed being rendered soluble by heating to 135‹ C. after an addition of butyric acid chloride: linters are introduced into chlorobenzene, lauryl chloride, and whale oil acid chloride, and the whole heated on an oil-bath to produce a soluble mixed ester; cotton is first heated in a steam-bath with lauryl chloride, pyridine bases and chlorobenzene, and subsequently with the addition of naphthenic acid chloride and pyridine bases while raising the temperature to 110 - 120‹ C.; cellulose acetate insoluble in acetone, is swollen with chlorobenzene and pyridine bases, and esterified with naphthenic acid chloride while heating to 110-120‹ C.; linters are impregnated with chlorobenzene or xylene and pyridine bases, heated to 50‹ C. and then treated with acetyl chloride, subsequently pyridine bases and palmityl chloride are added while heating on a steam-bath to produce an insoluble mixed ester, or if the temperature is raised to 120‹ C., a soluble mixed ester; soda cellulose prepared from wood pulp, is heated in an autoclave with powdered caustic soda, benzene and ethyl chloride, the mass is then rendered strongly acid with acetic acid, and to it are added pyridine bases and naphthenic acid chloride and the heating continued at 80‹ C., producing a soluble mixed ester. Specifications 284,298 and 292,929 also are referred to. The Specification as open to inspection under Sect. 91 (3) (a) states that if the reaction is carried out below 100‹ C., the subsequent heating may be omitted if the product is to be worked up according to the process of Specification 289,063. This subject-matter does not appear in the Specification as accepted.