US2192219A - Sizing of cellulose ether and ester materials - Google Patents

Description

Patented Mar. 5, 1940 UNITEDSTATES QFFICE ziisiar a No Drawings.

This invention relates to the treatment of cellulose ether and ester materials and more particularly to the sizing of cellulose acetate materials prior to weaving.

The sizing of certain textile materials with starch or starch derivatives presents special" problems, particularly in the sizing of regenerated cellulose and cellulose ether and ester materials. Thus, in sizing regenerated cellulose an ordinary starch size adheresso well to the ma terial that a distinct problem is encountered in I, desizing the material after weaving. In otherf words, there appears to be a bond or afllnity between a, starch size and a regenerated cellulose; On the other hand, fibers such as the wellknown cellulose acetate when sized with ordinary amylaceous sizing compositions fail to weave properly, the size being rapidly removedv from. the fibers under the chafing action of weaving. For 0 this reason it has not been possible to satisfactorily size cellulose ester yarns such as cellulose acetate with amylaceous products, and it has been necessary to rely entirely .upon special sizes, particularly sizes of a protein nature such 25 as gelatin. casein and the.like.

It is an object of this invention to provide a method of sizing cellulose acetate and other cellulose ester or cellulose ether materials utilizing amylaceous materials. A further object is the 30 preparation of improved cellulose acetate sizing compositions. Another object is to prepare cellulose ecetate sized with a composition which strengthens the fibers to resist the mechanical action of the loom and is not rapidly removed 35 under the chafing action of weaving. Other objects will appear hereinafter.

These objects are accomplished in accordance with this invention by incorporating about to or more of urea in a specially prepared m starch derivative and applying the resultant composition as a sizing composition to cellulose ester or ether fibers, particularly cellulose acttate. I have found that such a sizing composition becomes bound to cellulose acetate fibers,

45 that is, it shows a natural afilnity previouslylacking. The exact nature of this action is unknown, but it seems to be due to some coordinate valence bonding between the starch on the one hand and the cellulose ester on the other. 50 Good results can be obtained with compositions containing a minor proportion of urea and a major proportion of a dispersible amylaceous material, the amount of urea preferably being about 25% to 75% by weight of the amylaceous 55' material.

Application June 14, 1937, erlal No. 148,113

9' Claims. (01. 1344-23) g The manner in which the invention may be practiced wlll'be illustrated, but is not limited, by the following example in which the quantities are stated in parts by weight:

Eeample 'A sizing composition was prepared by mixing together 10-parts of a modified starch, 2 to 6 parts of urea, "and '40 to 80 parts of water,-and heating the mixture at atemperature of about 10 180? with agitation for 15 minutes.

A cellulose: 'acetatecyarn was then sized by -'the skein "method'by: immersing it in the resultant sizing composition -at-.a temperature of about 140 to ab0ut .150 F. Ifdesired, the sizing may 5 be efieete'din the cold at temperatures of say 60" t0'80 F.

--Thesize strengthened the fibers to resist the mechanical action" of the loom'and was not rapidly removedunder the chafing action of weav- 20 ing; After weaving'thesize was readily removable by washing with water.

In the above example auxiliary agents may be added-to the composition, for instance, 1.5 parts of glycerine or 3 parts of Turkey red. This 25 form'ulacan be used for both skein and warp sizing. I

In a similar manner other compositions may be prepared in'accordance with the invention, with varying-proportions of urea and amylaceous matter. It is usually preferable to employ a starch degeneration product, by which is meant a derivative of starch such as may be obtained by the various processes of making thin-boiling and so-called soluble starches and dextrins. By a specially modified starch is meant a starch degeneration product which, after having been colloidally dispersed in water, yields a dried protective film of suitable physical characteristics for the purpose involved. In order to obtain these characteristics and to form so-called solutions suitable for textile application, ordinary undegenerated starch is suitably degenerated in part, or modified, by various chemical and heat treatments. If desired,. mixtures of undegenerated starch and modifled starches may be used in conjunction with the urea. A

The term amylaceous material is employed herein to cover starch and starch derivatives or degeneration products. The expression "starch degeneration products" is employed to cover dextrins as well as modified starches. Among the suitable starchy materials may be mentioned wheat, rye, barley, oat, rice, maize and potato starches, sago and cassava flours and starch dato use a sizing composition having a ratio of solids to water within the range of about 2:5 to about 1:7.

The amount of such material incorporated into or applied to the cellulose acetate-is subject to variation, but ordinarily good results are obtained by adding to the cellulose acetate about 4% to about 6% of the sizing composition based upon the normally air-dry weight of the sized material. The amount of sizing composition retained by the material treated will depend largely upon the concentration of the bath and the time of treatment. Ordinarily the bath may be either hot or cold. The method of treatment may be the warp method, skein method or any other suitable method.

It will be recognized that a wide variety of auxiliary agents may be added to the sizing compositions herein described. Among such addition agents may be mentioned fullers earth, bentonite; wetting, penetrating and dispersing agents, for example, sulfonated oils,'higher alcohol sulfates (e. g., dodecyl sulfate, cetyl sulfate, and similar compounds), dlethylene glycol, glycerine and related substances. The proportions of these materials may also vary, depending upon the type of treatment and the material treated. For instance, it is usually preferable to use about 2 parts of glycerine or 4 parts of Turkey red oil for each 80 parts of sizing composition in the treatment of cellulose acetate materials. It will be observed that applicant's compositions are of such a nature as to be permanently water dispersible even upon the application of heat.

In preparing the sizing compositions described above it is preferable to prepare a dry blend of amylaceous binding agent and urea as a base material. This blend is marketed in dry or powdered form and requires only the addition of water and mixing, preferably with heating, to produce the sizing composition. Auxiliary materials such as those mentioned above may also be included in the dry base.

It will be apparent that the use of an amylaceous material intimately dispersed with urea in sizing textile fibers such as cellulose acetate has many advantages over the use of the amylaceous substance or urea per se. starchy materials .alone have not proven satisfactory in cellulose acetate sizing because of the lack of afiinlty with cellulose acetate. Urea has been suggested for use in conjunction with starch and other materials in veneer glues but has not heretofore been applied to starch sizing mixtures for cellulose acetate and similar materials. Urea solutions have also been used to reduce the infiammability of materials, but the use of urea alone does not fulfill the function of the combination of urea and starch or starch degeneration products for the treatment of cellulose acetate and similar materials as herein described.

Having thus described the invention, what I claim as new "and desire to secureby Letters Patent of the United States is:

1. In the art of sizing cellulose ether and ester materials, the step which comprises applying to said materials a permanently water dispersible composition containing an intimate dispersion of an amylaceous substance and urea, the amount of urea being at least about 20% by weight of the amylaceous substance.

A method of sizing cellulose acetate yarn which comprises treating the yarn with a permanently water dispersible intimate dispersion of an amylaceous substance and urea in water, the amount of urea being at least about by weight of the amylaceous substance and the ratio of solids to water being within the range of about 2:5 to about 1:7.

3- A method of sizing cellulose acetate yarn which consists in treating the yarn with an intimate dispersion consisting essentially of about 10 parts of a modified starch, 2 to 6 parts of urea and 40 to 80 parts of water.

4. A cellulose acetate sizing composition com-' prising a permanently water dispersible intimate dispersion of an amylaceous substance and urea in water:

A cellulose acetate sizing composition-comprising a permanently water dispersible intimate dispersion of a starch degeneration product and main water, the amount of urea being about 25% to about 75% by weight of the starch degeneration product and the ratio of solids to water being within the range of about 2:5 to about 1':'7. 6. A sizing composition adapted for sizing cellulose acetate fibers prior to weaving and consisting essentially of an intimate dispersion of about parts of a modified starch and about 2 to about 6 parts of urea in about 40 to about 80 parts of water.

'I. A cellulose ether and ester material sized with a permanently water dispersible intimate dispersion of an amylaceous substance and urea in water.

A cellulose acetate material containing a sizing composition consisting essentially of a major proportion of amylaceous substance and a minor proportion of urea, the amount of urea being at least 25% by weight of the amylaceous substance.

9. A cellulose acetate material containing a permanently water dispersible sizing composition having an amylaceous material as its sole or substantially its sole binding agent and containing urea in an amount from about 25% to about 75% by weight of the amylaceous material.

HERMAN B. BOSLAND.

CERTIFICATE OF CORRECTION.-

Patent No. 2, 19?,219. March 5, l9lLO.

HERMAN s. B0sLA1 rD. It is hereby certified that error appears in the printed specification of the shore numbered patent requiring correction as follows: Page 1, first column, line 52, for "acetate" r'ead acetate; and second column, line 25,

after the word "red" insert oil; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office Signed and sealed this 9th day of April, A. D. l9h0.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents