US1999182A - Artificial filament - Google Patents

Description

Fatented Apr. 30,: E935 MNHTED STATES ARTIFICIAL FILAMENT Camille Dreyfus, New York, N. Y., and William Whitehead, Cumberland, Md., assignors to Gelanese Corporation of tion of Delaware America, a corporan Drawing. Application November 18, 1930, Serial No. 496,562

6 Claims.

This invention relates to the preparation of artificial filaments, yarns and the like and re lates more particularly to the preparation of yarns having apleasing appearance and improved textile properties.

An object of our invention is to prepare artificial filaments having improved appearance and other desirable properties 'and which contain a titanic acid. Other objects of our invention will appear from the following detailed description.

It has been previously proposed to incorporate inorganic pigment-like material in artificial yarn to subdue the lustre and increase the opacity thereof. In commercial processes involving the use of such pigments, many considerations enter so that the choice of a commercially suitable pigment is quite dificult. We have found that such pigment must grind easily, must have good covering power, must have a low specific gravity so that it does not tend to separate out readily from the spinning solution to which it is added, and preferably should be of light color. We have found that the titanic acids meet these requirements.

In accordance with our invention we prepare artificial filaments containing cellulosic materials which have improved properties by incorporating therein a finely divided titanic acid.

The filaments made or treated in accordance with this invention may be of low fine denier which are associated together to form yarn, or the filaments may be, heavier such as bristles, artificialhorsehair and straw. Such filaments may be of the reconstituted cellulose type formed by the Chardonnet or cuprammonium process, but this invention is particularly applicable to filaments containing organic derivatives of cellulose such as organic esters of cellulose and cellulose ethers. Examples of such organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate, while examples of cellulose ethers are ethyl cellulose, methyl cellulose and benzyl cellulose. The filaments containing the organic derivative of cellulose may be prepared by dissolving the organic derivative in a volatile solvent such as acetone and extruding such solutions through fine orifices into an evaporative atmosphere, as in dry spinning, or into a precipitating bath, as in wet Spinning.

As stated, we incorporate in the filaments a finely divided titanic acid. While any suitable titanic acid may be used, we-prefer to use the titanic acid having the formula HzTiOa, which may be formed by adding an aqueous solution of sodium carbonate to an aqueous solution of potassium titanium oxalate and then washing and drying the precipitate. These titanic acids are white in color and have remarkably high covering power. Moreover, titanic acid is much softer 5 than titanium dioxide and therefore filaments or yarns containing titanic acid do not tend to cut machinery parts, such as guides, knitting needles, etc: as readily as filaments or yarns containing a like amount of titanium dioxide.

In one form of our invention, the titanic acid is incorporated in the dope or spinning solution containing the cellulose compound. Generally the amount of titanic acid added is from 0.1 to 10% of the weight of the cellulose compound present in the finished yarn. The titanic acid is preferably in very fine form, the particles having a diameter of less than 0.1 to 5 microns and preferably less than 1 or 2 microns for increased covering power. This fine size may be attained 20 by grinding the titanic acid either with water or part of the spinning solution or the solvent used in the spinning solution in a ball mill'or colloid mill. The ground material is then added to the solution of the derivative of cellulose and to which mayalso be added diethylene glycol, heavy white mineral oil, olive oil, castor oil or other oils. The spinning solution containing the pigment is then preferably thoroughly mixed and subjected to the usual filtration before spinning. However the addition of the titanic acid to the spinning'dope at any stage of the filtration process or even after completion of filtration is not excluded.

In another form of our invention, the finely divided titantic acid is incorporated in the yarns or filaments by treating such yarns or filaments after their formation either'in the form, of hanks or in the form of woven or knitted fabric with a suspension of titanic acid in the presence of a swelling or penetrating agent for the cellulosic material of which such filaments are composed which causes the titanic acid to become disseminated throughout the filaments. Thus if the filaments are made of cellulose acetate, the swelling agent employed may be an aqueous solution of acetone, acetic acid, thiocyanates of sodium, potassium or ammonium, diacetone alcohol or any other suitable swelling agent.

Filaments or yarns made in accordance with this invention have a subdued lustre and increased opacity and covering power, the amount of which depends upon the fineness of the size of the titanic acid particles and the amount employed. Yarns made in accordance with this invention have highly improved textile properties,

as is shown by. the fact that they can be knitted to form circular knit or warp knit fabrics having many wales and courses and which are free of distortions and pin holes. Moreover such yarns may be woven to form fabrics which arefree of warp streaks and weft bars.

Yarns prepared by our method may be wound and twisted more readily and form cones or other packages which do not tend to collapse. Heavier filaments such as bristles, straw and the like when made in accordance with this invention have improved knotting properties.

In order further to illustrate our invention, but without being limited thereto, the following specific example is given.

Example One (1) part by weight of an acetone soluble cellulose acetate is dissolved in three (3) parts by weight of acetone and to this is added one hundredth (0.01) part by weight of titanic acid (HzTiOa) in a small amount of water or acetone preferably containing cellulose acetate. This dispersion maybe obtained by grinding the titanic acid with the liquid, to whichgranules or fibers of If desired olive oil or 'diethylene glycolor a mixture of the two, in amounts of 1 to 5% of the weight of the cellulose acetate present may be added to the solution of the cellulose acetate prior to spinning. Also instead of adding the finely divided titanic acid to the spinning solution before the filtration, it may be added after such filtration.

It is to be understood that the foregoing description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire and claim to secure by Letters Patent is:

1. Artificial products containing a finely divided titanic acid.

2. Artificial products containing an organic derivative of cellulose and a finely divided titanic acid.

3. Artificial filaments or yarn containing cellulose acetate and a finely divided titanic acid.

4. Artificial filaments or yarn containing finely divided particles of a titanic acid having a. diameter of less than 5 microns.

5. Artificial filaments or yarn containing cellulose acetate and finely divided particles of a titanic acid having a diameter of less than 2 microns.

1 6. Artificial filaments or yarns containing an organic derivative of cellulose, an oil and a finely divided titanic acid.

CAMILLE DREYFUS. WILLIAM WHITEHEAD.