US2288361A - Hosiery - Google Patents

Description

Patented June 30,1942

HOSIERY Otto Kress and Charles E. Johnson, Appleton,

Wisconsin Wis., assignors to The Institute of Paper Chemistry, Appleton, Wis,

a corporation of No Drawing. Application-June 23, 1939,

Serial No. 280,704

19 Claims.

The present invention relates to improved hosiery and the method of making the same. More specifically, the present invention is directed to the replacement of a protein-rubber protective agent upon fibers in which the original protective agent has been substantially removed in processing.

Silk, wool and other fibers possess inherent undesirable characteristics with which the hosiery industry have been struggling for years to overcome. Natural silk, for example, has the firmness, strength and body desired, but through processing a relatively highpercentage of protective gum supplied by nature is removed and silk becomes hygroscopic, pervious to dirt, perspiration and the like, which makes the fiber susceptible to rapid deterioration. The processing treatments materially decrease the fiber strength and desired stretch and stockings made from the processed fiber have little resistance to snagging and the subsequent development of runs. Returning a protective agent to fibers, which restores strength, increases stretch, etc. without diminishing the desirable qualities obtained through processing, has long been a problem of the manufacturers of hosiery.

Many treatments have been attempted in the past but for the most part all have failed to fully accomplish the essentialrequirements. Some of the better known treatments have been, dipping the hosiery in solutions of mineral salts, sizing with starch, glues and waxes, sizing with mineral soaps, etc. In addition, the dipping of hosiery in rubber solutions has also been su gested. All of these prior treatments have had objectionable features, such as, the inability to apply evenly and uniformly, the changing of the appearance from that of natural silk to an artificial silk, lack of permanency, tendency to stiffen and harshen the fabric, danger of rancidity on storing, etc. The rubberized hosiery in particular has been found unsatisfactory due to its sticky and clammy feel and rapid deteriorationdn storage and under influence of heat and light. Although the art apparently appreciated the potential value of rubber gums in the treatment of hosiery, satisfactory compositions'and methods of application, free from the above noted as well as other objections, have not been available up to the present time.

Therefore, the principal object of our invention is to provide, compositions and processes adapted v for use in the manufacture of improved hosiery free from thedisadvantages enumerated above.

Further objects will be apparent as soription hereinafter proceeds.

We have discovered that the stable protein emulsion such as described in our co-pending application, Serial No. 76,008, filed April 23, 1936, now Patent Number 2,172,392, are adapted for use in conjunction with rubber compositions in the manufacture of improved hosiery. The hosiery treated with our novel emulsion comprising finely divided waxy material and finely divided rubber particles dispersed in an aqueous medium containing a relatively high percentage of protein material and a smaller amount of a the dewater soluble emulsifying agent, are free from the disadvantages encountered in treating hosiery with the prior compositions and particularly the prior rubber containing compositions. For example, hosiery treated with our emulsion as hereinafter described are not sticky or clammy nor are they subject to deterioration in storage or deterioration under the influence of heat and light encountered in commercial practice. Hosiery treated in accordance with the present invention is of greatly increased strength and. stretch, and highly resistant to the development of runs. No difiiculty is encountered in uniform application of our emulsion to the hosiery, the hosiery being free from rubber, protein and wax spots.

Our emulsions which are prepared by adding liquid or molten waxy material and. rubber solution, e. g. latex, to an aqueous alkaline solution containing a suitable emulsifying agent and a relatively high percentage of water insoluble, acid precipitable protein and subjecting the same to agitation, are stable and lend themselves readily to commercial operation. L1 practice, we have found it desirable to break or precipitate the emulsion by addition of a small amount of dilute ourselves to any particular theory of action, our investigations indicate that the emulsion when broken by acidic materials forms minute particles of wax and rubber coated with a film of insolubilized protein which prevents coalescence of the wax and rubber as well as the protein into large particles. In other words, the protein and the rubber material and waxy material which latter materials may act as a carrier and an elastic lubricant for the protein, appear to actively cooperate and prevent agglomeration. The protein film also appears to stabilize the rubber and prevent deterioration during storage as well as protect the rubber from break-down due to the action of sunlight and heat. In addition, the

formation of snags and the acidic material. -While we do not wish to limit protective film of insolubilized casein-type protein eliminates the sticking of the treated stockings to the shaping forms, one of the inherent commercial disadvantages encountered in the manufacture of rubberized hosiery in accordance with previously suggested processes.

The following example will serve to illustrate the preparation of an emulsion in accordance with our invention.

About 30 pounds of casein (e; g. alpha soya bean protein) is added to about 13 gallons of water heated to a temperature of about 140-150 F. and the mixture stirred for about minutes until the protein swells. About 1.5 pounds of caustic soda (5 percent based on the weight of the casein) dissolved in about 1 gallon of water is added to the water-casein mixture which is maintained at a temperature of about 140-150 F. and stirred for about 15 minutes or until the protein is completely dispersed or dissolved. To the alkaline casein solution is next added about 15 pounds of ammonium oleate. To this mixture, which is being agitated with a suitable high speed agitator at a speed varying from 600 to 1700 R. P. M., there are added slowly about 90 pounds of a molten waxy material such, for example, as a water-white odorless paraifin wax (M. Pt. 124 F.) Complete dispersion is-attained in about minutes when the melted parafiin or oil no longer remains on the surface of the emulsion. Warm water may be added to the proteinwax emulsion so as to obtain the desired fiow characteristics or viscosity. This emulsion has a protein to wax ratio of 1:3.

In a separate container about 60 pounds of soya casein are mixed with about 600 pounds of water at a temperature of about 140 F. To this mixture are next added about 3 pounds of caustic soda (5 percent based on the weight of the casein) dissolved in a small amount of water. The mixture is stirred for about 15 minutes until the protein is completely dispersed. The protein solution is then cooled to around 100 F. and 1115 pounds of rubber latex solution percent rubber i. e. 446 pounds dry rubber) added. The original protein-wax emulsion, the preparation of which is described above, isthen added to the protein-latex dispersion with proper stirring (mild agitation) and the final emulsion diluted with warm water (100 F.) to the desired consistency. For ordinary practice sufiicient water is added to make the total mixture approximately 9160 pounds, which gives a solution consisting of about 4.87 percent (e. g. about 5 percent) rubber and about 2.13 percent proteinparafiin-ammonium oleate (e. g. about 2 percent protein-wax). The ratio of protein to paraffin wax in the final emulsion being about 1:1.

It will be understood that the above example is not to be interpreted as limiting our invention. For example, the soya bean casein for which may be substituted any water-insoluble, alkali-soluble, acid precipitable protein such as milk casein, may be added in a single addition instead of forming the separate protein-wax and proteinrubber dispersions as above described. In place of the caustic soda employed in the above example, any alkaline protein solubilizing compositions may be used including ammonium and alkali hydroxides and alkaline reacting salts such as borax, the sodium carbonates and the tri and di-sodium phosphates. If an alkaline reacting salt is used in place of the strongly alkaline sodium hydroxide employed above, it has been found necessary to use a slightly higher proportion of solubilizing salt. For example, if sodium carbonate (soda ash) is used about 7 percent based on the weight of the protein has been found sufiicient to give complete and uniform dispersion. In place of the ammonium oleate used in the above example, any suitable emulsifier may be employed such as the sulphonated oils, Turkey red oil, soluble soaps of any nature, triethanolamine, gums such as gum arabic, etc. Our investigations have shown that the proportion of emulsifying agent used should be at least about one-eighth of the amount of waxy material employed, although it is ordinarily preferred to employ approximately a 1:6 ratio of ammonium oleate to waxy material with a protein to waxy material ratio of about 1:1.

It will also be understood by those skilled in the art that in place of parafiin wax used in the above example, any inert waxy material may be substituted therefor including lower and higher melting point paraiiin or mineral Waxes including Vaseline, vegetable waxes including carnauba wax, natural waxes, inert fats and oils and the like.

It will likewise .be understood that our invention is not limited to the above temperatures and proportions of the various ingredients used in our preferred process. For example, our investigations have shown that a 1:3 to 3:1 protein to wax ratio and 1:12 to 1:1 protein to rubber ratio may be employed. In practice, a protein to wax ratio of 1:2 to 2:1 and a protein to rubber ratio of 1:6 to 3:6 is ordinarily preferred while for silk hosiery a protein to wax to rubber ratio of about 1:1:5 is, under the conditions described, preferred. In place of the preferred high speed stirrer above indicated, any suitable type colloidal mill or homogenizing equipment may be substituted therefor.

The latex used in the present invention is the ordinary commercial rubber latex. The amount of latex used will naturally vary-With the concentration of rubber contained in the latex dispersion, sufficient latex being added to furnish the requisite amount of rubber. The preferred type of rubber latex for use in the present invention is one which has been prevulcanized, not to the maximum extent but to approximately two-thirds of the strength which can be developed by maximum vulcanization. We also prefer to use a rubber latex to which a small amount of a suitable anti-oxidant has been added, which tends to prevent the oxidation of the fine rubber film. Latex including the partially vulcanized and stabilized rubber latex dispersions are available on the open market.

The emulsion, prepared for example as above described, may be applied in any suitable manner to the fibers either prior or subsequent to knitting. In practice, we have found it desirable to apply the emulsion to the knitted hose just after the completion of the dyeing operation when the fibers are moist. In our preferred process the moist stockings or socks are placed in a suitable container such as a rotary dye machine and are soaked in the protein-rubber-wax emulsion contained therein for about 20 to 40 minutes. The hose are then placed in an extractor centrifuge for a period of about one minute to remove excess emulsion. (The length of time depending on the degree of extraction desired.) The hose are next placed in another vat or container and treated for about 510 minutes with a dilute acidic solution such as a one-eighth to three-eighths percent iron-free paper makers emulsion bath may be adjusted to the desired concentration by addition of waterfor by addition of fresh emulsion. In practice, we have found a concentration of about 7 percent solid content (i. e. protein-rubber-wax) to be preferred, although lower (e. g. 3-5%) or higher (e. g. 911%) concentrations may be used, if desired. The use of low concentrations, e. g. 1 or 2 percent, yields corresponding results of less value due to the relatively small amount of emulsion retained by the fiber, while the use of high'concentrations, e. g. over 12 percent, increases danger of mechanical troubles, such as spotting of the finished hose, etc. Our investigations show that the preferred concentration of the rubber in the treating emulsion should be about 3 percent to '7 percent. The optimum concentrations which depend upon results desired, type of hosiery to be treated, etc. may be ascertained by experimental tests.

It will be understood that our invention is not limited to the above described method of emulsion application. Any suitable manner of incorporating the emulsion into the hosiery so as to thoroughly impregnate the threads or fibers may be employed. The times given in the above example are only illustrative and may be varied as desired to suit the weight of the hosiery treated etc. It will also be understood by those skilled in the art that our invention is not limited to the use of the above described acidic agent. Any suitable acidic agent or acid reacting salt, such as aluminum sulphate, that will break the alkaline protein-rubber-wax emulsion, may be used. The formaldehyde present in the acidic solution aids in insolubilizing the casein-type protein. The acidic reagents or protein insolubilizing agents employed should be such as do not deleteriously affect the colors of-the dyed fibers.

Our invention is adaptable for all types of hosiery including silk, wool, and cotton hose as well as hosiery made from synthetic compositions such as rayon, etc. However, as indicated above, our invention is particularly adaptable for use in the manufacture of improved silk hose. Hosiery treated in accordance with the present invention is rendered non-hygroscopic and impervious to dirt, etc. Of great importance, hosiery treated in accordancewith the present invention is of increased strength and stretch. The treated hose also has an extremely high resistance to snagging and the development of runs. Experiments run on age tests using both the standard oxygen bomb and oven-aging equipment indicate that hose treated-with our novel emulsion suffer no deterioration of the rubber film for a period of at least two years. Mill runs have shown the protein-rubber-wax emulsion of the present invention to be stable under pumping, agitation and other conditions encountered during actual commercial operation. No mechanical dimculties are encountered either through the spotting of the goods as a result of uneven application 'or through the sticking of the hose while being dried in the customary manner on the so-called boarding machines.

The emulsion of the present invention examined under the ultramicroscope shows a splendid Brownian movement, and when precipitated with alum or acid is free from agglomeration into large particles of any-of the precipitated ma-' terials. This characteristic is of the essence in the treatment of hosiery fibers. Ordinary rubber latex dispersions on the other-hand due to the agglomeration of rubber particles has been found unsatisfactory for use in the hosiery art.

One of the greatest advantages of our invention was in the discovery that our novel emulsion made the fibers highly flexible and elastic and gave the stockings the desired increase in stretch.

, In the hosiery art this property is also of the essence.

. Although we have illustrated our invention with a preferred process and specified ingredients, it willbe understood that our invention is not limited thereto. For example, our emulsion may be applied in some instances without subsequent treatment with acidic material, although the precipitations with alum or the like is preferred. Likewise, although we prefer to applyv the emulsion to the hose and then treat with an acidic solution the reverse, i. e. initial treatment with alum and subsequent application of the emulsion, may be followed, if desired.

The treated hose of the present invention is water resistant and retains the desired splashproof properties of hose treated in accordance with our related co-pending application for Proteinized hosiery, Serial No. 181,294, filed December 23, 1937, now Patent Number 2,192,919. This characteristic is not obtainable using ordinary rubber-compositions, including latex, which in addition, are relatively unstable. The improved hosiery of the present invention is dependent upon the wax-rubber combination as well as the specific protein, all of which are essential ingredients of the treating emulsion.

All modifications coming within the spirit and scope of our invention are intended to be covered by the following claims.

.We claim:

1. The step in the method of treating hosiery which comprises applying to hosiery an emulsion consisting of an aqueous dispersion containing a water-insoluble, acid precipitable protein, a rubber latex, particles of inert waxy material and a water-soluble emulsifying agent, the ratio of protein to waxy material being about 1:3 to 3:1 and the ratio of protein to. rubber being about 1:12 to 1:1, so that the protein surrounds and forms a film about the rubber and waxy material particles preventing agglomeration of the protein, rubber and waxy material when the emulsion is broken by addition of acidic material. v

2. The step in the method of treating hosiery emulsion consisting essentially of an aqueous alkaline dispersion of an alkali-soluble, waterinsoluble, acid precipitable protein, a rubber latex, particles of inert waxy material and an emulsifying agent, and breaking the emulsion contained in the hosiery by treating the same with a dilute acidic material, the ratio of protein to waxy material being about 1:3 to 3:1 and the alkaline dispersion of casein,

ratio of protein to rubber being about 1:12 to 1:1 so that the protein surrounds and forms a film about the rubber and waxy material particles preventing agglomeration of the protein, rubber and-waxy material when the emulsion is broken upon addition of the acidic material.

4. The steps in the method of treating hosiery which comprises impregnating hosiery with a dispersion containing as its essential ingredients an aqueous alkaline dispersion of a casein protein, a stabilized rubber latex, a mineral wax and a water-soluble emulsifying agent, and breaking the dispersion contained in the hosiery by treating the hosiery with an acidic material, the ratio of protein to wax being 1:3 to 3:1 and the ratio of protein to rubber being about 1:12 to 1:1.

5. The steps in the method of treating hosiery which comprises impregnating hosiery with an emulsion containing an aqueous alkaline dispersion of soya bean casein, a partially pre-vulcanized rubber latex,a paraflin wax and a soap emulsifying agent, and breaking the emulsion contained in the hosiery by treating the hosiery with an aqueous aluminum sulphate solution, the ratio of casein to wax being about 1:1 and said emulsion containing about 2 percent of caseinwax and approximately 5 percent rubber.

6. The method of precipitating rubber material upon silk fibers particularly adapted for use in the hosiery art, which comprises treating the fibers with an emulsion consisting of anaqueous alkaline dispersion of a water-insoluble casein, a rubber latex, an inert waxy material and an emulsifying retained by the fibers by treating the fibers with a dilute aqueous solution of alum. the ratio of casein to waxy material being about 1:2 to 2:1 and said emulsion containing about 5 to 9 percent casein-rubber-wax, the percentage of rubber in said emulsion being about 3 to 7- percent.

'7. The method of precipitating rubber material upon hosiery fibers which comprises treating the fibers with an emulsion consisting of an aqueous alkaline dispersion of soya bean protein, a rubber latex, a paraffin wax having a melting point of about 124 F., and a soap emulsifying agent, and breaking theemulsion by treating the fibers with an aqueous paper makers alum solution, the ratio of protein to parafiin and rubber being such as to prevent agglomeration of the protein, wax and rubber into large particles upon treatment with the alum solution.

mineral wax and an emulsifying agent, removto rubber being about 1:5.

9. The steps in the method of treating silk hosiery which comprises impregnating the hosiery with an emulsion consisting of an aqueous alkali dispersion of soya bean casein, a pre-vulcanized rubber latex, a 'paraflln wax and ammonium'oleate, removing excess emulsion from the hosiery and breaking the emulsion remaining in the hosiery by impregnating the hosiery! with a dilute aqueous aluminum sulphate solution containing a small amount offormaldehyde,

agent, and breaking the emulsion the ratio of casein to rubber being about 1:5, said emulsion containing about 5 percent rubber.

10. The method of precipitating rubber material upon silk hosiery, which comprises treating the hosiery with an emulsion consisting of an aqueous caustic soda dispersion of alpha soya bean protein, a rubber latex in which rubber has been partially vulcanized and stabilized by the addition of a small amount of a rubber antioxidant, parafiin wax and ammonium oleate, and breaking the emulsion retained by the hosiery by treating the same with a dilute aqueous formaldehyde solution of paper makers alum, the ratio of protein to ratio of protein to rubberbeing about 1:5, and the total protein-rubber-wax content in said emulsion being approximately 7 percent.

11. As a new article of manufacture, hosiery having incorporated therewith a composition made up of minute particles of rubber, and inert waxy material surrounded by a film of a waterinsoluble, acid precipitable protein, the ratio of protein-to waxy material being about 1:3 to 3 :1 and the ratio of protein to rubber being about 1:12 to 1:1.

12. As a new article of manufacture, hosiery having incorporated therewith a composition consisting essentially of minute particles of rubber and mineral wax surrounded by a film of insolubilized casein, the ratio of casein to wax being about 1:1 and the ratio of casein to rubber being about 1:5.

13. As a new article of manufacture, hosiery fibers having precipitated thereon a composition consisting essentially of minute particles of paralfin wax and rubber surrounded by a film of soya bean protein, the ratio of protein to wax being about 1:2 to 2:1 and the ratio of protein to rubber being about 1:5.

14. As a new article of manufacture, silk hosiery having precipitated on the fibers thereof, a composition made up of minute particles of paraffin wax and partially vulcanized rubber surrounded by a film of insolubilized soya bean casein, the ratio of casein to wax to rubber being about 1:1:5.

15. A silk stocking having precipitated on the threads thereof a composition consisting of minute particles of a lubricating inert waxy material and' minute particles of an elastic antioxidant stabilized partially vulcanized latex rubber, said particles being coated with a paper makers alum-formaldehyde insolubilized alpha soya bean protein.

16. Hosiery having incorporated therewith the paper makers alum precipitate of an emulsion consisting of an aqueous alkaline dispersion comprising a water-insoluble acid-precipitable protein, a rubber latex, particles of inert waxy material and an emulsifying agent, the ratio of protein to waxy material being about 1:2 to 2:1 and the ratio of protein to rubber being about 1:6 to 3:6.

17. Hosiery having incorporated therewith an aluminum sulphate precipitate of an emulsion consisting essentially of an aqueous alkaline dispersion ,of a water-insoluble casein protein, a stabilized rubber latex, particles of mineral wax and a soap emulsifying agent, the ratio of casein to rubber to wax being such as to prevent agglomeration and formation of large particles.

.18. Silk hosiery having incorporated therewith a paper makers alum-formaldehyde precipitate.

. of an emulsion consisting of an aqueous alkali the ratio of casein to wax being about 1:1 and dispersion of soya bean protein, a partially vulparaflin being about 1:1, the

canized rubber latex, particles of parafl'in wax and ammonium oleate, the ratio of protein to wax being about 1:1 and the ratio of protein to rubber being about 1:5, said emulsion containing about 5 percent rubber.

' 19. Silk hosiery having precipitated on the fibers thereof an acidic precipitate of a rubber latex emulsion consisting of an aqueous alkaline dispersion of a'water-insoluble, "acid-precipitable protein, particles of an inert waxy material and an emulsifying agent, suflicient protein being presentto prevent agglomeration and formation of large particles when the emulsion is broken CERTIFICATE OF CORRECTION.

Patent No. 2,288,561. June 30, 19m.

' OTTO 'KRESS, ET AL,

It is herebyeertified tint error appears iii the printed specification of the above numbered patent requiring c0 rrection as follows: Page 5, second column, lineflhb, claim 1, after the word "aqueous" insert "alkaline";

and that the said Letters Patent should beread with this correction thereirithat the same may conform to the record-of the case iri the Patent Office.

signed and. sealed this tum day of August, A. D. 191;.2.

Henry Veh Arsdale,- (Seal) Acting Commissioner of Patents.