US2108838A - Artificial material having modified characteristics and method of making same - Google Patents

Description

Patented Feb. 22, 19

DICE? ARTIFICIAL MATERIAL G MODIFIED CHARACTERISTICS o WTHOD @F MAKING SAME' William Whitehead, Cumberland, assignor to Celanese Corporation of America, a com.

tion or Delaware No Drawing.

Application April 3, 1935,

Serial No. 14,473

' 4 Claims.

This invention relates to the preparation and manufacture of yarns, filaments, fabrics and other articles from artificial materials which, after formation, are chemically treated to modify their 5 physical characteristics, and more particularly to the method of chemically treating the yarn whereby the amount of physical change is made visible to theeye by means of an indicator or similar material. This invention particularly relates to the preparation and manufacture -of yarns, filaments, fabrics and other articles containing organic esters of cellulose wherein at least a part of the filaments employed are treated with.a basic material to alter the acid value of the material or to sensitize the same for saponification.

An object of the invention is the economic and expeditious production of textile materials containing yarns and filaments of an organic material especially an organic ester of cellulose, which materials are so treated that any degree of physi-" cal or chemical modification, such as saponification or sensitization for saponiflcation, is registered through an indicator such that the operator may readily, and without the aid of instruments,

ascertain the degree of treatment that the mate rials have undergone, or to ascertain which part of the materials have been treated. A further ob-- ject of my invention is the production of textile 0 materials and fabrics, which contain yarns of organic esters of cellulose, which have been periodically treated with a saponifying or sensitizing agent and also with an indicator such that,

I upon visual inspection of the yarn and fabrics, 35 the locality of the saponification and/or sensitizing may be easily ascertained. A still further ob- Ject of the invention is theproduction of yarns and filaments which are so lubricated and/or treated that they are made particularly ame- 4o nable to textile operations and subsequent chemical treatments. Other objects of the invention will appear from the following detaileddescription.

cals or in any other manner to change their char- I 50 acteristics, which change although difilcult to see with the naked eye, nevertheless changes the pH value at least at the surface of the yarn, thus making a change in the color of the indicator which becomes readily visible. Thus, by employ- I ing this invention, very minute changes or By employing this invention, which in general 5 consists in applying to yarns and filaments a lunar-2o) changes not readily seen with the eye maybe made in the fabric, yarns and filaments, yet due to the highly sensitive indicator a fairly close observation may be kept on the extent and locality of the treatment. In this manner a much more uniform material may be produced, as the operator can watch immediately upon application of the treatment the extent of that treatment and, make any adjustments necessary to make the treatment uniform. Although this invention has 10 many uses, it is of particular applicability in the various processes wherein organic esters of cellwlose are saponified. Thus, in the treatment of yarns and filaments or fabrics containing organic esters of cellulose with a saponifying agent which 15 merely etches or partially saponifies the same, or sensitizes the same so that the sensitized materials may be developed in soap bathspetc. in later treatments, this invention is of great advantage in that the partial saponification of the yarn, 20 which is sometimes so slight as not to be identified without the use of the elaborate means for weight ing the yarn, etc., is made obvious to the eye due to the change in the color of the indicator at the places which have been contacted by the saponifying agent; This invention also may be used with advantage in the treatment of yarns wherein the yarns are saponified throughout their length,

in whichcase any differencev in the amount of application of saponifyin'g agent on various increments of the yarn that may produce a streaky appearance on the yarn may be indicated by the change in the color of the indicator and thus allow for change intreatment to correct any'lack of uniformity.

:A further advantage of this'invention is that the yarns" and filaments may be coated with a lubricant which allows for the material to pass through guides, needles, etc. and to be formed into fabrics of fine stitch shape. .The lubricant, which 40 preferably contains the color indicator, may be selected according to the subsequent treatment to be given the yarn; Thus, when the yarn'is to-be subsequently saponified, non-saponifiable oils containing an acid color indicator may be employed as the lubricant, which lubricant, although conditioning the yarn for all textile operations, does not interfere with the saponification, or sensitizing by partial saponificatlon, in the subsequent treatments.

In accordance with my invention, I incorporate with yarns or filaments or other artificial materials a lubricant containing a color indicator, which incorporation is preferably made by coating' the yarn: with an oily material containing an 55 apply a coating of a non-saponifiable lubricant containing an acid dyestuif to yarns and filaments during a winding operation and then apply to the yarns or filaments or fabrics made therefrom, either in localized areas or the entire surface thereof, either a basic material capable of at least partially saponifying the material to an extent sufficient to sensitize those parts coated with the basic material, or a saponifying agent of sufficient strength or for a sufficient length of time and temperature to materially saponify the material.

This invention is applicable to the treatment of yarns, filaments or other artificial materials formed of any suitable ester of cellulose or other artificial material. For instance, I may employ this invention in the treatment of yarns and filaments formed from the nitrates of cellulose, the organic esters of cellulose, cellulose others, or regenerated or reconstituted cellulose made by either the cuprammonium or the viscose methods. Examples of organic esters of cellulose and cellulose ethers that may be employed are cellulose acetate, cellulose formate and cellulose propionate as the cellulose esters, while examples of cellulose ethers are methyl cellulose, ethyl cellulose and benzyl cellulose. The yarns or filaments containing these organic esters of cellulose materials may be formed by either the wet or dry methods of spinning and may contain besides the derivatives of cellulose base material, effect materials such as pigments, dyes, lakes, fillers, plasticizers and lubricants,

Any suitable artificial material, or for that matter natural textile materials such as cotton, wool and the like, may be coated with a coating containing a lubricant and a color indicator, which color indicator and lubricant are chosen according to the subsequent treatment to be given the material. However, for application to textile materials formed of or containing organic esters of cellulose, which are to be subsequently treated with a base material for any purpose such as sensitizing the same for saponification in soap solution or for the'partial, intermittent, or total saponification, the textile materials may be lubricated with. a lubricant which is non-saponifiable and does not form a soap with the basic material used in the saponifying operations. Accordingly, theremay be used any of the following: mineral oils, fatty alcohols, glycerols, glycols, their substitution products and derivatives, or combinations of these materials. An example of a suitable combination of these materials is a fatty alcohol dissolved in mineral oil. It is preferable, when treating an organic ester of cellulose with a basic material, however, to incorporate with the textile materials a sulphonated naphthene dispersed in mineral oils as a better spread on the artificial material is obtained in this way and, also, the sulphonated naphthene acts to make the lubricant easily emulsifiable and readily scoured free from thematerial. Although vegetable oils are usually saponifiable, certain quantities of the same may be mixed with the unsaponifiable lubricants named above.

- As a preferred lubricant. for the treatment of organic esters of cellulose which are to be subsequently treated with a basic material, I may use one containing an acid color dissolved in sulphonated naphthene which in turn is dispersed in amineral oil. This dispersion may be applied to the yarns or filaments by applying the same with a furnishing device during any winding operation. Any suitable furnishing device may be employed, such as a wick or a roller dipping into the lubricating material and contacting with the travelling yarns and filaments as they are being wound upon a package. Although it is preferable to apply the lubricant during the winding operation, the same may be applied in any other suitable manner such as by hank dipping, forcing the lubricant through packages of the material, or by adding the lubricant to the spinning solution from which the yarns and filaments are formed.

Any suitable acid color dyestuif may be employed as the, color indicator to be dissolved or dispersed in the lubricant when treating organic derivatives of cellulose. These acid colors are usually very good indicators to make visible the pH concentration of the medium containing them. For example, there may be employed such acid colors as Violet BK, Methyl Green, Acid Green and similar acid colors that belong to the group of diand tri-amino derivatives of triphenylmethane and diphenylnaphthylmethane coloring matters. Other coloring matters that change color upon a change of pH value or upon the presence of specific reagents may be employed. When employing organic derivative of cellulose yarn, the above acid colors are of particular advantage because they may be easily scoured from the yarn. In treating yarns of other materials, indicators that merely tint the yarn and do not dye the same may likewise be selected.

After the yarns or filaments have been lubricated in accordance with this invention, they may be formed into fabrics in any suitable manner. The lubrication may be effected prior to any subsequent chemical treatment, and before forming the yarns into a fabric. The chemical treatment may be carried out during the same winding operation in which the lubricating step is effected or during a subsequent winding operation. When it is desired to chemically treat, such as by a saponifying agent, fabrics formed from yarns or filaments containing an organic ester of cellulose, as by printing a design upon the fabric with a saponifying agent or treating the whole of the fabric with a saponifying agent, the lubricated yarns or filaments may be employed in the fabric in any suitable manner to efficiently distribute the color indicator throughout the fabric or that part of the fabric to be treated. Lubricated yarns having the indicator thereon may be employed as the warp threads of the fabric or the weft threads of a fabric or as both warp and weft threads. These yarns may contain filaments made of other materials, such as yarns or threads of organic derivatives of cellulose that do not contain an indicator, wool, cotton, silk, flax, etc., or the lubricated yarns containing the color indicator may be woven into fabrics along with such other yarns or threads in any suitable manner. The fabrics may be formed of these threads, or combination of threads, by weaving, warp knitting, circularknitting, netting and knotting.

This invention is particularly applicable to the treatment of yarns of organic esters of cellulose as the same are formed, that is, a lubricant containing color indicator is applied prior to the first winding operation, thus giving to the yarns a color which makes them identifiable throughout the subsequent processes, which yarns are later to be sensitized for saponification during a subsequent Winding operation. The yarn containing the lubricant and color indicator may be caused to contact, or periodically contact, with a furnishing device supplying a saponiiying agent to the yarn in sumcient amount to merely etch the surface of the yarn by the saponifying action, which treatment may be termed sensitizing the yarn, as the yarn if later treated with a soap solution, saponifles in those rts which are etched, while the unetched portions are unaffected by the soap solution. This partial 'saponification or sensitizing, as it is applied during a winding operation, is' commercially limited by the amount of caustic that may be safely applied in such a way that the saponifying action actually taking place at this point is very light. For instance, the saponification is carried to such an extent that the loss in weight of the yarn at those parts sensitized is from 2 to 7%. This very light sapcnification, although capable of being developed in later treatments to a very heavy saponification, is nevertheless so light that it is dicult to observe at this stage. With the color indicator upon the yarn, however, those parts of the yarn contacted by the saponifying agent changes the pH value at the surface of the yarn, thus giving an obvious change in color to the indicator. The operator, under these conditions, may readily see how much of the area is being contacted by the saponifying agent merely by comparison of colors. The sensitizing or saponifying agent employed to treat the yarns, filaments or fabrics containing an organic ester of cellulose may be any suitable saponifying agent having a, pH valueof from 10.5 to 14. Any suitable basic solution may be employed for this purpose, such as an aqueous solution or an alcoholicsolution of an alkali hydroxide, for instance, sodium hydroxide or potassium hydroxide, an aqueous solution of ammonium hydroxide, a salt of a strong base, such as ammonia or alkali, and a weal: acid such as organic acids, organic compounds having a basic reaction, etc. Examples of salts of a strong base and an organic acid which may be employed for this inventionare sodium acetate, potassium acetate, etc. Examples of organic bases that may be employed as the sensitizing or saponifying agent are the primary, secondary and tertiary amines, for instance, ethanolamine, methanol amine, di-methanol amine, di-ethan'ol amine, tri-methanol amine and tri-ethanol amine. Also, quaternary ammonium bases may be employed, for instance, tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, etc. These materials may be applied to the yarn from aqueous solutions, which solutlons may be of any suitable concentration such that the. pH value of the solution is above 10. These and similar saponifylng or sensitizing agents do not materially interfere with the lubricating coating originally applied to the yarn, especially when said coating comprises an acid color in sulphonated naphthene dispersed in mineral oil or an acid color dissolved in a. mixture of a glycerol or a glycol, their derivatives or substitution products, and any suitable non-saponifiable oily material. When treating fabrics with a saponifying agent, the same may be applied by special devices such as a printing machine, etc.

Thus, in carryingout my inventiom -a yam treated at formation with a lubricant containing a color indicator such as Violet 5 BK is of a deep blue color. When this yarn is contacted by a saponiiying agent, that part of the yarn contacted changes to a red or a color between blue and red, depending upon the concentration of the hydrogen ion in the saponifying material, which concentration governs the shade or color of the indicator. In the partial saponification of organic esters of cellulose, the locality of treatment, may be readily ascertained. In other tym of treatment even the extent of treatment as well. as the locality may be indicated, especially in treatments that do not form salts.

As an aid to illustrating this invention and not as a. limitation, the following example is given:

Example An acetone soluble cellulose acetate yarn is formed by the dry method of spinning and prior to being wound into a. package it is caused to contact with a wich supplying thereto a coating comprising i i of an acid color, Violet 5 BK, dissolved in 20 parts of sulphonated naphthene, which in turn is dispersed in 75 parts of light mineral oil, in such a manner that the lubricant adhering to the yarn amounts to about 5% based on the weight of the yarn. The yarn thus produced is of a bright blue color and sufflciently lubricated for all textile operations.

This yarn is then re-wound and during the rematerial is found not to interfere with the speed or depth at which the saponifying agent attaclrs the yarn, nor is the lubricant decreased in value or altered in any manner to cause the yarn to become less adaptable for textile operations such as weaving, etc.

Although this invention has been described somewhat in detail with reference to applying the treatment during a winding operation, it nevertheless has applicability to the treatment of fabrics formed of lubricated yarns, the lubricant of which contains a. color indicator. The fabric thus produced will be of a solid blue color and printing paste may be applied thereto containing saponifying agents in any suitable concentration to give a light or heavy saponiflcation, and the parts contacted or printed with such paste become readily visible due to the change in color at the point or parts contacted with the saponifying ents. This invention has also been described somew in detail with reference to the lubricating of yarns for the purpose of indicating the extentpi area of saponification. It is nevertheless applicable to treatment of yarns with materials other than saponifying agents. For instance, color indicators may be employed when treating the yarns with any reagent which alters the pH value of the surface of the yarn, for instance, treatments with dilute acids, salts and similar materials for the purpose of producing shrinkage,

crepe or other desired effects in the material, or

visible the extent and concentration of treatment.

In the selection of the lubricant and color indicator, it is usually preferable to select -such a lubricant that may be readily scoured free from the material and such a color indicator that has no afilnity for the material being treated and thus does not permanently stain the material and interfere with dyeing operations or the production of material of natural color. Any suitable amount of lubricating material may be applied to the yarn, for instance, from 1 to 20% or more of lubricant on the weight of the yarn. The lubrieating material may contain from 1 to 10% of a coloring or tinting compound as an indicator.

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

Having described my invention, what I desire to secure by Letters Patent is:

i. In a process for saponifying yarns, filaments, fabrics and like materials having a basis of a cellulose ester by treatment with an alkaline reagent, the step which comprises indicating changes in the pH value on the materials during the saponification by means of a coating applied to the materials, said coating containing a fugitive coloring pH indicator, whereby the extent or degree of saponification may be visibly ascertained.

2. In a process for saponifying yarns, fllaments, fabrics and like materials having a basis of cellulose acetate by treatment with an alkaline reagent, the step which comprises indicating changes in the pH value on the materials during the saponiflcation by means of a coating applied to the materials, said coating containing a fugitive coloring pH indicator dispersed in a scour.- able lubricant, whereby the extent or degree of saponlflcation may be visibly ascertained.

3. In a process for locally saponifylng yarns, filaments, fabrics and like materials having a basis of cellulose acetate by treatment with an alkaline reagent, the step which comprises indicating local changes in the pH value by means of a coatingapplied over the whole surface of the material prior to the saponification treatment, said coating containing a fugitive coloring pH indicator dispersed in a scourable lubricant, whereby the extent or degree of saponification may be visibly ascertained.

l. In a process for saponifylng yarns, filaments, fabrics and like materials having a basis of cellulose acetate by treatment with an alkaline reagent, the step which comprises indicating changes in the pl-l value on the materials during the saponiflcation by means of a coating applied to the materials, said coating containing an acid color having no dyeing aflinlty for the cellulose acetate, whereby the extent or degree of saponification may be visibly ascertained.

WEMAM WEHTEHEAD.