US2225843A - Fur treating composition and process - Google Patents

Description

Patented Dec. 24, 1940 PATENT OFFICE FUR TREATIlgG COMPOSITION AND aoonss William Page, Cranford, and Morris Lefkowitz, Irvington, N. J.

No Drawing.

'7 Claims.

The present invention is concerned with the production of fur which may be readily processed into felt of improved quality. The invention more particularly is concerned with an improved so-called carroting process by which rabbit, hare, beaver, and similar types of fur are treated, utilizing as a carroting solution an aqueous mixture comprising a zinc salt, an oxidizing agent, and a hydrolyzing agent. In accordance with the present process, a carroted fur is produced which may be readily processed into a smooth, strong, tight felt which will exhibit substantially improved wearing qualities. Our process is particularly desirable in that the resulting product is of a higher quality than has heretofore been secured and that this product is secured in an economical and efilcient process which is entirely innocuous with respect to the health of the operating personnel.

It is well known in the art to process animal fur, particularly rabbit, hare, beaver, and similar types of fur, by a carroting process which generally comprises treating the fur with an aqueous solution of mercuric nitrate and nitric acid. This solution is usually applied to the fur while still on the pelt although it may be applied after removal of the fur from the pelt. The fur is then dried at temperatures ranging from atmospheric to temperatures as high as 250 F. or higher, depending upon the nature of the fur and the type and quality of final treated product desired. The drying conditions vary considerably, depending to a large extent upon the particular fur being processed, the carroting solution employed, as well as upon general atmospheric and other related conditions. However, due to the fact that mercury and mercury salts are toxic in nature and may adversely affect the health of the operating personnel in contact with felting processes and related arts, it has been suggested that various non-mercuric carroting solutions be substituted for the mercuric carrotiug solutions. In general, these mercury-free solutions comprise an oxidation agent, as for example chloric acid, bromic acid, iodic acid, permanganic acid, hydrogen peroxide, and the like, and a hydrolyzing agent, such as sulfuric acid, acids of phosphorus,

or equivalent acids with function to duplicate.

the oxidation and hydrolyzing effects secured by the nitric acid present in the mercuric nitrate solution.

The hydrolyzing agents in general are characterized by having a high ionization value and by being relatively non-volatile at drying tem- 5 peratures. Qesirable hydrolyzing agents, fur- Application February 10, 1940, Serial No. 318,324

thermore, are relatively stable so that side reactions resultlng in the consumption of the agent do not occur during the processing. Particular non-mercurous carroting solutions which have been suggested are, for example, a solution comprising an oxidation .agentsuch as permanganic acid and a hydrolyzing agent which is preferably sulfuric acid or a carroting solution in which the oxidizing agent is a peroxide, as for example, hydrogen peroxide. These solutions, in general, 10 have not been commercially successful duein part to the fact that they have slow starting and slow sizing characteristics. It is also known that although certain desired results may be secured in the carroting process, provided the treating reagents are sufficiently strong and concentrated; Other deleterious factors are encountered in that the life of the fiber is adversely affected, particularly with respect to its wearing ability and with respect to its ability to absorb 0 color. Furthermore, when utilizing sulphuric acid as the hydrolyzing agent, increasing the concentrations of the same will tend to cause formation of tarry matter on the surface of the fiber giving it a burnt appearance and rendering it 25 unsuitable for use. In order to overcome th disadvantages of this type of carroting solution, numerous suggestions have been made for incorporating various inhibiting and catalytic agents into respective non-mercuric solutions which have not produced. material benefits, particularly with respect to duplicating the efiiciency of the mercuric nitrate solution and the uniform quality of the resulting product.

We have now discovered a non-toxic carroting solution which may be efliciently employed for the production of a carroted fur of exceptionally high uniform quality. The carroted fur produced by our process is' extremely stable and may be stored for longperiods of time without any substantial deterioration of the fiber occurring. Our carroted fur may be readily felted with an exceptionally low loss in weight during. the felting operation. Furthermore, the felted product produced from our fur is smoothly and tightly interlaced, resulting in the production of a fabric having exceptionally fine, natural lustre and resiliency of the fibers, which in turn contributes to the appearance and wearingquality of the felt. Our felt is also characterized in that it has the ability to absorb and indefinitely retain without fading all dye shades without objectionable overcast or other mottled efiects or background.

The carroting solution of our invention comp ses 8-. zinc salt, an oxidizing agent, and a hydrolyzingagent. Although the zinc salt may comprise the chloride or the nitrate, the preferred zinc salt is the sulfate. The oxidizing agent may comprise any known satisfactory oxidizing agent used in carroting processes, as for example, iodic acid, permanganic acid, hydrogen peroxide, and the like. However, in general, we prefer to employ hydrogen peroxide in combination with the zinc sulfate. The hydrolyzing agent likewise may comprise any satisfactory material which is generally characterized by having a high ionization value and which is relatively non-volatile at the temperatures of drying, as for example, a sulphuric acid, hydrochloric acid, nitric acid, or an acid of phosphorus. In

general, however, we have found that particularly desirable results are secured, provided zinc sulfate, hydrogen peroxide, and sulphuric acid be used in conjunction with one another.

The concentration, of the particular constituents in our carroting composition may vary considerably depending upon reagents employed. For example when utilizing a preferred composition it is desirable that the concentration of the zinc sulphate be in the range from about 2 to 10% by weight, particularly in the range from about 5 to 7%, that the weight concentration of the-hydrogen peroxide based on a hundred volume solution, be about equivalent to or several per cent higher than the weight concentration of the zinc sulphate; and that the weight concentration of the sulfuric acid be about 40% to 60% greater than the concentration of the zinc sulphate, based upon 66 Baum acid or equivalent. treating composition consists of an aqueous solution of about 6% by weight of zinc sulphate, about 8% by-weight of volume hydrogen peroxide, and about 9% by weight of 66 Baum sulfuric or its equivalent.

The properties of'our solution may be somewhat varied and controlled by the addition thereto of various inhibiting and catalyzing agents. In this regard we have further discov ered that the effectiveness and desirability of our solution is considerably enhanced provided a low ionizable organic acid and for example acetic acid and the like be employed in conjunction therewith, and that its value is further enhanced provided a ketone, particularly acetone, is also employed. We have also discovered that the waste, a loss of weight in felting, is materially reduced provided tannic acid be em- For example, a very satisfactory centrations' of the same be from two to three times the weight concentration of the zinc sulphate. The preferred tannic acid concentration is from about $3 to 8% weight per cent. A

particular desirable solution consists of from about 5 to 8% by weight zinc sulphate, 5 to 7% tannic acid, 12 to 25% of 28% acetic acid, 5 to l 10% of 66 Baum sulphuric acid and from about 4 to 8% of 100 volume hydrogen peroxide.

In order to further illustrate the invention the following examples are given which should not be construed as limiting the same in any manner whatsoever:

Example Preferred carroting solution-A Weight per cent Zinc sulphate- 6 Sulphuric acid, 66 Baum 9 Acetic acid, 28% 16 ,Hydrogen peroxide, 100 volume solution 6 Preferred carroting solution- B Zinc sulphate 5 Sulphuric acid, 66 Baum 9 Acetic acid, 28% 16 Hydrogen peroxide, 100 yolume solution 6 Preferred carrotz'ng soZutionC Zinc sulphate H 5 Sulphuric acid, 66 Baum 9 Acetone 16 Hydrogen peroxide, 100 volume solution 8 Preferred carrotz'ng solution-D Zinc chloride 5 Acetic acid, 28% 10 Hydrogen peroxide, 100 volume solution 6 Preferred carrot ing solutionE Zinc sulphate 5 Tannic' acid 7 Acetic acid, 28% l5 Sulphuric acid, 66 Baum 7 Hydrogen peroxide, volume solution 4 The results secured when employing the respective solutions are as follows:

Felting process shrinking liercenft characteristics Carroting composition Appearance of fur after treating, g

em We drying and cutting ff tir Machine Machine comlpen's felting stflmgg A" B (mun 8) (minutes) (minutes) Commercial mercuric nitrate carrot.- Good yield, glossy, fibers cling ll 4 8 18 Very good. Commerc al nonmercur c carrot, #1... Poor yield, dull, harsh appearance" 28 3% 10 22 Fair. Commerc al nonmercur c carrot, #2-.. Fair yield, slightly dull appearance..-. 2% 4% 12 33 Do. Commerc al nonmercuric carrot, #3... Fair yield, iur darkened, some gloss 27 6% 18 50 Poor. Commercial nonmercuric carrot, #4... Poor yield. some gloss, pungent (odor) 24 5 /4 10 20 Do. Preferred carrot ng solution (A) Good yield, harsh feel 15 5 /6 10 20 Good. Preferred carrot ng solution (B).. Good yield, glossy, fibers adhesive 17 5% ll 21 Very good. Preferred carrotlng solution (C) Good yield, some gloss, harsh feel"... 20 424 12 26 Good. Preferred carrotlng solution (D) Good yield, some gloss, good appear- 21 6 12 24 Fair.

, ance.

Preferred carroting solution (E) Good yield, glossy, fibers adhesive. 3 5% 10 20 Very good.

' N umber of times through machine for initial shrinking.

"Time required for shrinking to intermediate predetermined fixed size.

*Time required for shrinking to final predetermined fixed size.

ployed in conjunction with our solution. When employing acetic acid or acetone or equivalent reagents it is preferred that the weight con- From the above-data it is apparent that the carroting solutions of the present invention possess distinct advantages and result in an imwith a carroting solution comprising zinc sul-- proved product. The felted material furthermore is apparently impregnated in a manner with zinc which materially facilitates theshaping and sizing operations and results in the production of a product of a fine texture and lustre having improved properties with respect to its ability to retain its shape and wear for longer time period under extremely adverse conditions:

The process of the present invention is not to be limited by any theory or mode of operation but only in and by the following claims by which it is desired to claim all novelty insofar as the prior art permits.

' We claim:

1. A composition for carroting fur comprising zinc sulphate, acetic acid, a peroxidizing agent and an hydrolyzing agent.

2. A composition as defined by claim the concentration of the zinc sulphate is in the range from about 5% to 8% and the concentration of acetic acid is in the range from about 12% 3. A process for the production of fur which may-be readily felted comprising treating fur 1 in which phate, acetic acid, a peroxidizing agent and an hydrolyzing agent.

4. A process as defined by claim 3 in which the hydrolyzing agent comprises sulfuric acid.

5. A composition for carroting fur comprising zinc sulphate, acetic acid, tannic acid, a peroxidizing agent and an hydrolyzing agent.

6. A compositionfor carroting fur comprising 5% to 8% by weight of zinc sulphate, 5% to 7% of tannic acid, 12% to 25% by weight of 28% acetic acid, 5% to 10% of 66 Baum sulfuric acid, and from about 4% to 8% of 100 volume hydrogen peroxide.

WILLIAM PAGE. MORRIS LEFKOWITZ.