US3082110A - Stabilized yarn - Google Patents

Description

United States Patent 3,h82,110 sTAliillllZE i) YARN Robert C. Harrington, In, and James L. Smith, Kmgsport,

Tenn, assignors to Eastman Kodak Company, Rochestel, N.Y., a corporation of New Jersey No Drawing. Filed Oct. 25, 1960, Ser. No. 64,694 7 (Ilairns. (Cl. 106-194) This invention relates to a composition of matter, especially a cellulose ester containing composition whlch composition exhibits stability to actinic radiation. More particularly, this invention relates to dull and semi-dull cellulose ester filaments which are relatively highly stable toward photodegradation.

It is already well known in the industry to prepare spinning solutions of spinnable materials such as cellulose esters dissolved in a solvent. It is further known to extrude such spinning solutions through spinnerettes to form filaments therefrom by the elimination of the solvent from the extruded materials. In the manufacture of the so-called dull or semi-dull or delustered fibers, it is customary to include a pigment in the spinning solution for obtaining the dull or delustered effect. As is well known, titanium dioxide in finely divided form is a frequently used delustering pigment.

Studies have shown that scission of the polymer chain of the fiber forming material by light is catalyzed by titanium dioxide. Therefore, photodegradation of dull or semi-dull or the like delustered fibers is more severe than for the so-called bright yarns which do not include or include a lesser amount of such pigments as titanium dioxide. In order to retard such type photodegradation especially in the dull or delustered fibers as just referred to, it has already been proposed to incorporate ultraviolet light absorbing materials and antioxidants into the spinning compositions or onto the surface of the fibers or fabrics woven therefrom. Presumably the functioning of prior additives has been postulated on the theory that peroxides are formed in the fibers through the absorption of ultraviolet radiations. Thus the fiber material might be protected if the rays or radiation can be absorbed preferentially by some compound incorporated in the fiber or if the peroxides once formed are quickly taken care of by some agent such as an antioxidant in the fiber.

While prior .art methods of stabilization have received some favorable acceptance in the industry, it is apparent that the development of further more simplified or different procedures for stabilizing cellulose ester compositions represents a highly desirable result. After extended o investigation we have found a procedure of stabilizing and a stabilizing agent which appears not only to very efiiciently function, but to function by a mechanism different from the prior art stabilizers and in a manner, the principle of which is presently unknown to us.

This invention has for one object to provide compositions of matter especially compositions containing a substantial content of cellulose .acetate which compositions exhibit relatively good stability toward actinic radiations. A particular object is to provide a cellulose acetate spinning solution which is relatively highly stable to actinic radiation and which may be spun into filaments wherein the resultant filaments not only possess their original properties, but have better stability to photodegradation. A further object is to provide cellulose acetate fibers so stabilized that they are not substantially deleteriously affected with respect to strength, elongation or color. A still further object is to provide procedure for incorporating certain novel additives into cellulose ester spinning solutions and the spinning of fibers from such solutions. Other objects will appear hereinafter.

In the broader aspects of the present invention we have found that compositions of matter and more par ticularly exemplified by spinning solutions which ma: have added thereto a small portion of zinc acetyl ace tonate with the beneficial effect that such combinatioi and the extruded products resulting therefrom have decreased rate of photodegradation. Zinc acetyl ace tonate is a compound having the following type formula CH2 ZI1(O(|.L1CH2-(I|]CH3)2 In general we have found that a concentration as lov as 0.1% based on the weight of the composition 0 matter will give a beneficial effect. Usually we WOlJlt not use more than 1.5% by Weight. In the instance 0 cellulose ester spinning solutions we have found that concentration between 0.4% and 0.7% based on thl cellulose ester weight is quite satisfactory. We havl found that our zinc acetyl acetonate additive is particu larly effective in cellulose ester spinning solutions whicl contain titanium dioxide delustering or dulling agents.

In further detail, zinc acetyl acetonate may be preparer by the following procedure. Four hundred ml. of ab solute ethyl alcohol were placed in a flask fitted with stirrer, condenser and thermometer. The alcohol wa protected from atmospheric moisture by means of a cal cium chloride tube. One mole, 23 grams, of sodium was added in small pieces. After all the sodium ha reacted, one mole of 2,4-pentanedione (acetyl acetone: was slowly added. The solution was maintained for 34 minutes at a temperature sufiicient to cause refluxing Then /2 mole (68.2 grams) of anhydrous zinc chloridl dissolved in absolute alcohol was added over a ZO-minutI period and the mixture was maintained at refluxing tem perature for an hour. The mixture was filtered whil. hot to remove precipitated sodium chloride. Zinc acety acetonate crystallized from the filtrate on cooling. I was collected by filtration and recrystallized from ethy alcohol.

While we prefer the foregoing type of method for pro ducing the zinc acetyl acetonate, the exact source of thi additive or its method of manufacture is not a limitatioi on the present invention. A suitable quality zinc acety acetonate is obtained and then ground in the presence 0 the type of solvent that is to be used in dissolving th solid material from which the fibers are to be produced For example, in the instance of cellulose acetate, aceton is the type of solvent usually used for dissolving th cellulose acetate. Therefore, the zinc acetyl acetonat would be ground in the presence of acetone. A spinnin, solution may be made in the usual way from the filamen forming material, titanium dioxide or comparable de lusterant, coloring material or the like together wit] 0.1% to 1.5% of the zinc acetyl acetonate of the presen invention. Such spinning solutions may then be spun int filaments by conventional procedures such as dry spin ning, wet spinning, melt spinning or the like to produc filaments which exhibit greater resistance to .actinic radia tions either in the filament form or in the form 0 products such as fabrics.

A further understanding of our invention may be ha from a consideration of the following examples whic'. are set forth for illustrating certain preferred embodi ments.

Example I In accordance with this example the white fine acety acetonate powder-like solid was ground in the presenc of acetone. This mixture was added to a 27% solutio: of secondary cellulose acetate in acetone in which 1.4% based on the acetate weight, of titanium dioxide ha been suspended. The concentration of zinc acetyl ace tonate was 0.5% based on the weight of cellulose ace :ate. The solution was dry spun in a conventional manner by extruding it through small orifices into a drying :hamber to remove the solvent. Continuous filament yarn of 150 denier with 38 filaments prepared as described above was used as filling in a 75-denier bright lcetate Warp. A satin Weave was used wherein the yarn ihowing on the dull side of the fabric commonly referred as the back, was about 80% cellulose acetate contain- .ng 0.5% zinc acetyl acetonate. The fabric was exposed ;0 light rich in ultraviolet in a Fade-Ometer, an instrunent utilizing a carbon arc. The dull side of the fabric was turned toward the light. A control fabric, identical :0 the one described above except that the 150 denier iull yarn contained no zinc acetyl acetonate, was exposed .0 light in the same manner.

Strips of each fabric were exposed in a Fade-Ometer for 400 and 600 hours. Before exposure and after each .ime period the samples were tested. The forces were neasured which were necessary to pull apart, in a longi- .udinal direction, strips one inch wide and three inches ong. The strips had been cut from the fabric samples that the filling was running longitudinally and thus the )ulling was done against the fibers in the filling. The ibers containing zinc acetyl acetonate retained a much arger portion of their original strength and lost strength ess quickly than the control samples. After 400 hours ;he control sample had lost 57% of its original strength vhile the one containing zinc acetyl acetonate had lost 52%. After 600 hours, the sample containing the zinc :ompound was 62% stronger than the control.

Example 11 Yarn containing 0.1% zinc acetyl acetonate was pre- :iared and tested in an analogous manner to the yarn in Example 1. After 600 hours in a Fade-Ometer the fabric was 38% stronger than a control fabric.

Example 111 A fiber forming spinning solution consisting of acetone lOlVGIlt, cellulose acetate (39.3% acetyl) at a concentra- ;ion of 27%, and zinc acetyl acetonate at a concentration )f 0.5% based upon the acetate weight was dry spun in 1 conventional manner. The fibers of 4 denier per filanent were wound on wire frames and exposed in a Fade- Dmeter for 400 hours. Control fibers containing no zinc rcetyl acetonate were prepared and tested in the same nanner. The stabilized fibers lost only 7.1% of their itrength while the control fibers lost 29%. In other words the stabilized fibers were losing strength at only he rate of the control fibers. After the same exposure aeriod, the percent loss in the elongation of the control ibers was 60 while the stabilized fiber lost only 0.55 per- :ent of its original elongation. It should be noted, as ilustrated by this example, that zinc acetyl acetonate also ;erves as a stabilizer in the absence of titanium dioxide.

Example IV Two films of cellulose acetate butyrate, 13% acetyl and 37% butyryl, one containing 0.7% zinc acetyl ace- :onate and the other no stabilizer were cast from acetone :olutions. The films, 0.05 inch thick were exposed to iltraviolet light in a Fade ometer for 400 hours. The ntrinsic viscosities of the polymers were determined both )efore and after exposure. The stabilized polymer lost nly 2 percent of its original intrinsic viscosity while the :ontrol which contained no zinc acetyl acetonate lost 18 Jercent. Loss in intrinsic viscosity is indicative of a coresponding loss in strength.

Example V Example IV was repeated except that cellulose triaceate films, one with 0.7% zinc acetylacetonate and the ather without the stabilizer, were cast from a solvent con- ;isting of nine parts of methylene chloride and one part of methanol by weight. After 400 hours in the Fade-Ometer the stabilized film had lost 6% of its original intrinsic viscosity while the control had lost 20%.

It can be seen from the foregoing description that we have provided a number of new compositions of matter, particularly in the form of spinning solutions.

Such spinning solutions enable the production of filamentary and fabric products that are more resistant to actinic radiation than comparable products heretofore available. While our invention is particularly applicable to cellulose acetate compositions in the form of acetone spinning solutions made therefrom, certain other benefits of our invention may be had in combination with other types of fiber and film forming materials. Illustrations of these variations are as follows: cellulose triacetate, cellulose tripropionate, cellulose acetate butyrate and mixtures of cellulosic esters with other polymers.

Although we prefer to use acetone as the solvent for the fiber forming materials and for grinding the additive, since it is a well-known readily available commercial solvent, other solvents and solvent combinations may be used illustrated by the following: chlorinated hydrocarbons such as methylene chloride and tetrachloroethane, chlorinated hydrocarbons mixed with low molecular weight alcohols such as that illustrated in Example V, and lower N,N dialkyl .alkanamides such as dimethyl formamide.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. As a new composition of matter adapted for spinning, a solution consisting principally of a lower cellulose ester, a solvent for said lower cellulose ester, and 0.1 to 1.5% of zinc acetyl acetonate based on the weight of said lower cellulose ester.

2. A composition according to claim 1 wherein the cellulose ester consists essentially of cellulose acetate and 0.25 to 5% by weight of said cellulose ester of titanium dioxide.

3. As a new article of manufacture, a fabric comprising a lower cellulose ester, 0.1 to 1.5% zinc acetyl acetonate based on the weight of said lower cellulose ester, and 0.2 to 5% titanium dioxide based on the weight of said lower cellulose ester.

4. A product in accordance with claim 3 wherein the lower cellulose ester consists essentially of cellulose acetate.

5. As a new article of manufacture, a fabric which consists essentially of lower cellulose ester fibers containing 0.1 to 1.5% by weight of zinc acetyl acetonate whereby the fibers exhibit enhanced resistance to photodegradation.

6. A product in accordance with claim 5 wherein the lower cellulose ester consists essentially of cellulose acetate.

7. The method of preparing filaments of increased resistance to actinic radiation which comprises dry spinning a solution of cellulose acetate, 0.1 to 1.5% zinc acetyl acetonate based on the weight of said cellulose acetate and 0.25 to 5% titanium dioxide based on the weight of said cellulose acetate.

References Cited in the file of this patent UNITED STATES PATENTS 2,615,860 Burgess Oct. 28, 1952 2,819,978 Long et al Ian. 14, 1958 FOREIGN PATENTS 830,475 France Aug. 1, 1938

Claims (1)

1. AS A NEW COMPOSITION OF MATTER ADAPTED FOR SPINNING, A SOLUTION CONSISTING PRINCIPALLY OF A LOWER CELLULOSE ESTER, A SOLVENT FOR SAID LOWER CELLULOSE ESTER, AND 0.1 TO 1.5% OF ZINC ACETYL ACETONATE BASED ON THE WEIGHT OF SAID LOWER CELLULOSE ESTER.