US1883347A - Process of making artificial filaments and product thereof - Google Patents

Description

Patented Oct. 18, I932.

CAMILLE oeuvres, or New YORILN. "2., AND ILLIAM WHITEHEAD, on CUMBERLAND.

'IYLALRYLAND, Ass enons 'ro oE NEsE CORPORATION 01?. AMERICA, Aoonron 'rIon,

or DELAW R rnoonss or MA ING No Drawing. Application filed September This invention relates'to'the production of artificial filaments, yarns, bristles and'the like made of or containing cellulosic material. An object of our invention'is to produce filaments of cellulosic material, which filaments contain lumens or other hollow-spaces reim 'nother object of'ourinvention is to "produce hollow filaments or bristles from solutions of cellulosio material by forming the same at a lower rate than has been previously employed. Other objects of our invention will appear from the following detaileddescription.

In the process of making artificial filaments is from cellulosic derivatives as now practiced, solutions of celluloslc' materlal are extruded orifices :of a spinnerette,

through circular either into a preclpitating bath, as in wet spinning, or into an evaporative atmosphere, as in dry spinning, and the filaments thus formed are drawn oil at a comparatively high speed, ranging from 25 to 200 meters of length of filament per minute. The filaments thus formed, however, have a solid cross section. We have found that if the rate of spinning is materially reduced, low spaces therein ma be formed. Such hollow filaments are pre erable to the solid-filaments, since for a given weight they have greater covering power than the solid filaments.

In accordancewith our'invention, we pre pare filaments having lumens or hollow spaces therein by the wet or dry spinning of solutions containing cellulosic derivatives at a much lower rate than has been previously employed. 7

By the process of our invention, filaments,

yarns, bristles or artificial horse-hair, etc. may be made. of a very fine denier, on the order of less than 2 to 15 or more denier, which filaments may be associated together to form artificial yarns.

This process may be employed for preparing strands or single filaments of much heavier denier such as 100, 300 to 1500'denier or more,

thus forming stifi' bristles or artificialhorsehair that maybe used in brushes that are adapted for toilet use. The filaments may s, 1928. Serial No. 304,804.

"or any other suitable material;

filaments having hol-' ride, ethylene dichloride-and ethyl or methyl alcohol.

The filaments formed maybe ARTIFICIAL II II II'rsANDrnoDI cr: 'rnnimor,

also be employed for making braids, ribbons This invention may be applied for makin filaments orbristles by the viscose metho wherein a solution .of viscose is extruded through spinnerettes into an aqueous bath containing a precipitating agent such' as an acid.

The invention is'eminentlysuited for mak lng filaments from organic derivativesof cel lulose. Examples of organic derivatives of .cellulose are organic esters of cellulosesuch as cellulose acetate, celluose 'formate, cellulosepropionate, cellulosebutyr'ate; or'cellulose ethersysuch as ethyl cellulose, methyl cellulose or of benzyl cellulose;- Tliese or- ,ganic derivatives of cellulose are'dissolved in.

a suitable solvent and the solution'extruded through orifices or a spinnerette, either into a bath containing a liquid which causespre cipitation of the cellulose derivativefrom the solution, or intoa drying and evaporative' atmosphereas in dry spinning;

The sol-vents employed formakin'g solutionsof the organic derivatives of cellulose maybe any suitable ones ,examples ofwhich a reaacetone, acetone and water, methylene chloride and ethyl alcohol, ethylene dichloalcohol (ethyl or methyl) ,rchloroform, or chloroform and As to the rate'of spinning, this is prefl erably. on the order'of 0.025 to 0.1 to5meters 'er' minute or more, dependin ofithe filaments to be produce .1 I s Thesize of theiorifices throughiwhich'the spinning solution'iisiextruded will-vary with the heaviness of the filament desired. More'- over, the speed at which'the filaments are 96 the filamentto be formed; i. e.- the heavier the V spun will vary inversely with the weight of filamentto be, formed, the slowerthe rate "of spinning.f..i

jon' thesize I The'filament after formation is preferably 1 drawn out while it still-retains some of the solvent ingorde'r to increaseits length.

so'drawingou't, filaments of superior tenac ty: areproduced.-

lumens or hollow spaces: therein as shown by RT he filament stormed our procesi haive an examination of the cross section thereof,

whichhas distinct holes.

While we do not limit ourselves to this theory, we believe that the formation of hollow filaments by our process is due to the fact that because of the low' rate of spinning, the spinning solution after issuing from the jets of the spinnerette first starts to dry or skin at the surface only, as in dry spinning, .or coagulate at the surface as in wet spinning, before the interior of the filament sets. Subsequently the interior of the filament dries or coagulates with some shrinkage, which owing to the previous formation of the solid hollow skin or shell of the filament, causes the formation of hollow spaces. j a

In order further to illustrateour invention without limiting'the scope thereof, the

following specific example is given.

Example The following is a description of a method of preparing bristles having hollow spaces therein. A solution is made by dissolving one part of an acetone soluble cellulose acetate having an actyl value of 54.5% in 4: parts and 5% water.

The solution is extruded through a spinnerette having one or more orifices of 0.8 mm. diameter into air, carbon dioxide or other inert gas having a temperature of 40 to 45 C. The filaments thus formed are drawn off by a roller at the rate of 0.1 meters per minute. As a result of this process filaments or bristles are ob tained that have a denier of approximately 1300, which bristles have lumens or hollow spaces therein. I

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be'madetherein without departing from the spirit of ourrin'vention. Having described our invention what we claim and desire to secure by Letters Patentis:'-

1.-Process of forming hollow filaments, bristles and the like comprising extruding a solution of an organic derivative of cellulose in a volatile solvent through orificesof a of a solvent mixture containing 95% acetone 7 spinnerette into an. evaporating atmosphere heated to a temperature below the boiling point of the solvent employed in the solut1on whereby solid cellulosic filaments are formed and drawing off the filament at such slow rate that the solvent evaporates at the surface of the filaments first sufiiciently to form asohd skinprior to the substantial 1 evaporation of the solvent in the interior of the filaments, whereby upon the evaporation of t e solvent inthe interior of the filament hollow filaments are formed. i

2. -rocess of forming hollow filaments, brlstles 1 and the like comprising f extruding an evaporative atmosphere of prior to the substantial evaporation ofthe solvent in the interior of the filaments, whereby upon the evaporation of the solvent in the interior of the filament hollow'filaments are formed. I '3. Process of forming hollow filaments comprisingextruding a solution of cellulose acetate in a volatile solvent through the orifices of a spinnerette into an evaporative atmosphere heated to atemperature below theboiling point of the volatile solvent and drawing ofl the filaments thus formed at a rate of less than 5 meters per minute.

In testimony whereof, we have hereunto subscribed our names.

' CAMILLE DREYFUS.

WILLIAM WHITEHEAD.