US1551112A - Manufacture of cellulose-acetate artificial silk - Google Patents

Description

so u at" a U U i Patented Aug. 25, 1925. UNITED STATES PATENT OFFICE.

HARRY S. MOB/K, F BRODKLINE, AND CHARLES E QQFFINIJR, OF WATER'IOWN, MASSACHTISE'I'TS, ASSIGNORS, BY MESNE ASSIGNMENTS, TO LUSTR-ON COMPANY, INC., OF BO STON, MASSACHUSETTS, A CORPORATION OF MASSAGI-IU$ETTS. S i 1' 4 x MANUFACTURE OF GELLULOSE-ACETA'IE ARTIFICIAL SILK.

No Drawing. Application filed March 22, 1923. Serial No. 626,872.

To all whom 2'25 may comer-n:

Be it known that We (1) HARRY S. Moan, and (2) CHARLES F. dOFlIN, J12, citizens of the United States, residing at (1) Brookline, (2) Watertown, in the counties of (1) Norfolk, (2) Middlesex, and State of (1) and (2) Massachusetts, have invented certain new and useful Improvements in the Mannfacture of Cellulose-Acetate Artificial Silk, of which the following is a specification.

lhis invention relates specifically to improvements in the manufacture of cellulose acetate artificial silk as described in United States Patent No. 1,107,222, patented August 11, 1914:, to Harry S. Mork.

The said patentdescribes a process of making cellulose acetate artificial silk com.- prising dissolving the celluloseacetate in a mixture of tetrachlorethaiie and an alcohol, and squirting the resulting solution through fine orifices into a pggg ulgting gr bath composed of one 6i inore aliphatic liydiihharbons, preferably petroleiun hydrocarbons, or a mixture of aliphatic hydrocarbons and tetrachloretlw-ne.

e have :tound that better coagulation can be secured, and consequently more uniform spinning conditions can be maintained, if there is incorporated in the original cellulose acetate solution a limited proportion of an aliphatic hydrocarbon or mixtures of aliphatic hydrocarbons. The ellect of such addition is to bring the spinning solution considerably nearer to its coagulating point, and thereby to improve the coagulation in the second bath. The aliq'hatic hydrocarbons to be added may be the same as those used in the coagulating bath, but as this latter usually comprises a mixture of various hydrocarbons boiling over aconsiderable temperature range, We regard it as preferable, though not essential, to add tothe original solution hydrocarbons correspond ing to the loner boiling constituents of the hydrocarbon mixture used in the coagulating bath. These lower-boiling hydrocarbons will dry out of the silk more rapidly. We do not however wish to restrict ourselves to the use of a hydrocarbon identical with a component of the coagulating bath, or a mixture of hydrocarbons corresponding to the mixture employed in the coagulating bath.

When the coagulation bath becomes heavily chargednvith..telilflthlorethan h'stilldltai oone1:the..,.t and the distillation may be conducted so that the tetrachloret-hane distilled oil will contain some hydrocarbons. Such a distillate can be used to provide all or part of the totrachlo-rethane and hydrocarbon necessary for the preparation of the spinning solution.

No definite percentage can be prescribed ance with our invention, it being understoodthat the invention is not limited to the particular materials or proportions recited therein by Way of illustration:

306 grams of fibrous cellulose acetate prepared m accordance with the United States Patent 854,374, patented May 21, 1907, to Harry S. Mork, are dissolved in a mixture ol 1120 e. c. of tetrachlorethane, 420 c. c. of denatured alcohol and 160 c. c. of 150 fire test kerosene. The solution'is thoroughly agitated, then filtered and squirted under pressure througha suitable spinneret into a coagulating bath composed of 9 parts by volume of kerosene and 1 part by volume of tetrachlorethane.

Another method of preparing a spinning solution is as follows:

306 grams of cellulose acetate are dissolved m a mixture of 1280 c. c. of tetrachlorethane distillate and 120 c. c. of denatured alcohol. lhe distillate may contain 87 72; of tetrachlorethane and 12 kesosene by volume.

It is not essential that the hydrocarbon be present in the solvent mixture when the cellulose acetate is dissolved because the cellulose acetate may first be dissolved in a mixture of commercially pure tetrachlorethane and a suitable alcohol and the hydrocarbon be subsequently mixed into the solution.

' tain.

To the solutions as above described may be further added other solvents and nonsolvents of the cellulose acetate such as chloroform, acetone, benzol, 'toluol, xylol, ethyl-methyl ketone, ethyl acetate, and carbon tetrachloride, for the purpose. of altering the coagulation properties of the solu tion or the character of the artificial silk produced therefrom. Similar results are obtained by the addition of aliphatic hydrocarbons or mixtures thereof or mixtures of alipathie hydrocarbons with other solvents and non-solvents of cellulose acetate to solutions of cellulose acetate insolvents other than 'tetraohlorethane or tetrachlorcthane and alcohol hereinbefore described. Other solvents for the cellulose acetate which may be used are for example chlorinated hydrocarbons of lower boiling point than tetrachlorethane, dichlormetlmne, chloroform, dicl'ilorethane, trichloretlnme etc., either alone or in conjunction With alcohol.

We claim:

1. As a novel composition of matter, a coagulable solution comprising cellulose acetate, tctrachlorethane, and an aliphatic hydrocarbon.

2. As a novel composition of matter, a

coagulable solution comprising cellulose acetate, tetrachlorethane, an aliphatic hydrocarbon and an alcohol.

Process of making cellulose acetate artificial silk comprising preparing a solution of cellulose acetate in a solvent containing' tetrachlorethane and an aliphatic hydrocarbon, and coagulating said solution in a bath likewise containing an aliphatic hydrocarbon.

at. Process according to claim 3 in which the cellulose acetate solvent comprises tetrachlorcthane, an alcohol, and an aliphatic hyd rocarbon.

As a novel composition of matter, a coagulable solution comprising cellulose acetate, a solvent therefor, and. an aliphatic hydrocarbon.

(3. Process of making cellulose acetate artificial sill: comprising preparing a solution comprising cellulose acetate, a. cellulose acetate solvent and an aliphatic hydrocarhon, and coagulating said solution in a bath comprising an aliphatic hydrocarbon.

In testimony whereof, We all'ix our signatures.

I-IARRY S. MORK. CHARLES F. COFFIN, JR.