US2508714A - Process of treating keratinous materials - Google Patents

Description

FIPSEU? XR faienteci May its REFERENCE rnocnss or TREATING KiiaATmoUs MATERIALS Milton Harris, Bethesda, Md., and Alfred E. Brown, Washington, D. 0., assignors to Harris Research Laboratories, Washington, D. C., a.

partnership N Drawing. Application October 7, 1946,

Serial No. 701,623

8 Claims. 1

The present invention relates to the treatment of keratinous' materials, such as wool, hair, fur and the'like, and to the product of such treatment. E

Thesematerials are characterized by the presen'ce therein of keratin, a fibrous protein containing amino acids including cystine. amino acids arejoined together by peptide linkages to form protein chains and the resultingchains are cross linked by the disulfide group (-SS) of cystine.

It is an object of the invention to provide an improved process for treating keratinous materials. A further object is to provide a processfor stripping color from wool and like materials.

Yet another object is to produce a modified keratinous material having improved-chemical properties combined with substantially unimpaired physical properties.

ucts such as shoddy, clippings, rags and the like, for reprocessing, it is necessary to remove the dye or color from the wool. The present-day practice is to strip colors from wool in acidic media with sodium or zinc formaldehyde sulfoxy late. This treatment adversely afiects the mechanical as well as the chemical properties of the wool even when the processing conditions are carefully'controlled. Both the wet and dry tensilestrength are decreased, especially the former, and often the wool acquires a dead'and harsh hand as compared with the untreated material. types of colors which are more difiicult to strip ping agent or the duration of the treatment must be increased. In some cases a second strip is The 'One application of theinvention is in the stripping of color from wool. In preparing wool prod- This problem is accentuated with (ore- 102)" f p and with which the concentration of the stripessential to remove the color and in these cases chemical damage to the wool is further increased. Wool products stripped by these conventional procedures also show an increased susceptibility to damage when treated under oxidizing,

reducing or alkaline conditions in subsequent processing.

By the process of the present invention it is possible not only to strip color from wool without substantial impairment of the mechanical properties .of the wool, but, quite apart from stripping. our process is useful in treating wool to improve its chemical properties and enhance its resistance to attack by oxidizing, reducing and alkaline agents.

In accordance with the invention, the kerati nous material is subjected to the action of areducing agent for keratm in the presence Oran.

alkylene. dihalide.

The action of reducing agents on keratinous material ordinarily results in rupture of disulfide linkagesand damage to the fiber. In our process,

however, the linkages ruptured by the reducing agent are immediately rebuilt with the formation o'fne'w'stable linkages. We provide an effective,

commercially practical process for replacing relatively unstable chemical bonds of keratinous material's'v'vith new chemical linkages whichare', resistant to the action of oxidizing, reducing and alkaline agents.

The invention is illustrated by the following examples of proceduresrby. which it maybe pu into practice: s

. Ezamplel 1.5: parts of 1, 2'-dichloroethane are dispersed inflf fl parts of borate solution adjusted to pH 8.6. 7.5 parts of sodium sulfoxylate-formaldehyde are dissolved in themixture, after which" 15 parts of wool are immersed'in the liquid. The" temperatureis raised to C. and held for one hour, after which the wool is removed, rinsed and ri V 7 Example 2 T9.-8 parts by weight of 1, 2-dibromoethane'are dispersed in '3000 parts of 1% borax by means of a small amount of a quaternary salt of a substituted fatty acid amide available commercially under the trade'name Sapamine KW. Any good dispersing agent'may be'used. 5 parts of sodium h'ydrosulfite are 'dissolvedin the mixture, after whichl00 parts of colored flannel rags are im- Inersed in the liquor,-and the mixture is kept at the boil for 15 30minutes. The wool is then rinsed anddried. The color is stripped from the wool by this treatment.

I tdmp e "1.5 parts'of l, -2-dibromoethane are dispersed in-450 parts of'borate buffer, pH 8.6, after which 0.7 part of sodium hydrosulflte are added. 15 parts of old red knits are'added. The mixture is treated at '80 C. for 30-60 minutes, after which I the wool is rinsed and dried. The color is stripped from the wool by this treatment.

Example 4 31.6 parts of 1,2-dibromoethane are dispersed in 4800 parts of water adjusted to pH 8.3 with borate solution. A convenient procedureis to" use' the required amount of a concentrated dis-y persionof 1,2-dibromo'ethane in water which can Example 45 parts of 1,2-dibromoethane are dispersed in 11,500 parts of water and the pH adjusted to 8.5 with borate buffer, after which '45 iof sodium hydrosulfite are added. 455 parts of wool cloth are added to this mixture. The entire mixture is then heated at 90-95 C. for oiiehour, after which the wool isrinsed and dried. The cloth is bleached li'ghtlyby this treatment. This treatment is also suitable for use'with'raw wool stock.

"Example 6 1.5 parts of 1, 2-dibromoethaneare dispersed in .450 parts of borate buffer, pH;8. 2, after which 0.7 part of formamidinesulfinicacidare added. parts of blue serge rags are thenaddedand h mixture is treat d $11 1 0.1 IQ! 30150 utes, after which the wool is rinsed anddried. The color is stripped from the serge by this treatment.

Example 7 '1.3 "parts of 1,2-"dibromoethane are dispersed in 420 parts of 0.3 molar boratestilution, by means of cetyl dimethylbenzyl ammonium chloride available commerciallyuncler the trade name ri on K-fiO, and 0. ar isOG Q K YE Sir formaldehyde are thendissolved. in the mixture. lip-a s o pas e sweate w r te s i in -$4.??? immersed in the mixture and the reaction carried out at the lboilro .3 to .60 min s. a er e ail the. o h s washedand dri d- -f-F afi9 0 is stripped from the worsteds by this treatment.

In general, the alkylenedihalides employed as alkylating agents in the foregoing examples are not completely miscible in water. It is advantageous in practice first to iorma concentrated dispersionef the alkyla-t-ing. agent in :water by the use of small amountsof suitable dispersing-agents such as those available commercially under the trade names of- Sapamine KW, Triton K-60, Span 60, Tween 60, and other dispersing agents having a similar action. Thisiconcentrateddispersion is thenadded inappropriate'amount to the solution containing the reducing agent, thus forming a suitable 'b'athfor the practice of our invention. y

The process of the invention is subject to variation, for example in the reducing and alkylating agents used and the --concen'tration thereon-the time of treatment, the temperature and pH of the bath, etc. 7

Examples oisuitable reducing agents are the various sulfoxylate-formaldehyde compounds, the 'hydrosulfites, formamadine 'sulfinic "acid and the like. Other reducing agents may beused, but they should be or a type which does not react with thealkylating agent (as would thiol compounds such, for "example, as fthioglycolic ecid and salts thereof, monothioethylene*glycol, an t ther mercaptans) since otherwise "the two cbmponents for 'thesolution would beexliausted by reaction with -each"other and would notice 4 available for reaction with the wool. The term reducing agent as used in the claims includes sulfoxylate formaldehyde compounds, hydrosulfites, formamidinesulfinic acid, and such other reducing agents for keratin asdo not react with 'alkylene dihalides.

In the case of stripping processes, the choice of reducing agent will depend on the cost and the quality of the strip and will also depend upon the type of 'dye or color to be removed. Small scale trials will quickly indicate the best set of conditions to use for. any given batch of goods. In some 'casesia much better strip can be obtained byfirstgivin'g the wool an ammonia scour, for

example with "2% to 5% of ammonia on the weight, of the wool for thirty minutes at 50" toIGOI C.

The amount of reducing agent employed may be varied over wide limits, up to or more on the weight of the wool, with no appreciable effect on the properties of the. modified 'wool p'roduced. In stripping. processes, in generali-3 to5% of 'the reducingag'ent'onthe weight ofthe wool will give an effective stripping action. Larger amounts may be .present in .the reaction mixture without significant, :adverse effect on the quality of the stripped. product. .With :colors which are difficult "to strip, it is advantageous to add the reducing :agent "in'increments "at :the boil, since maximum "reducing epowerzfor strip-e ping purposes is thus utilized.

Suitable alkylating a'gents are fthealkylerie' fiihalides and substituted and modifie'dallwlene dihali'des, f'or example, methylene rdibromide, methylene cliic xzlide, methylene ibromoiodide, eth-' ylene dibromide, "ethylene dichloride, .ethylerie chlorobromide, trimethylene 'dibromide,.-:1L4-:-di-. bromobutane, --1;4-dichloro-2 butene, .2,2=di'chlo-' rodiethyl ether, 4,4'-chloromethyl 'diphenyl rand 2,2-dibromodiethyl ether. The term falkylene dihal-ide as used;in 'th'e claims'zinclud'es substituted and modified'alkylene dihalides.

Very little alkylating agent is required; .as'little. as 0:00045 mol of alkylatin'g agent per gram of, wool gives -good results. riiharger amountsnhave no deleterious efiect.

. It hasbeen found desirable to maintain the pr: of the'solution at 7 or above and-preferably at pH 8-10. Adjustment of "the pH "to :the value. desired :can be made, :for example, with alkaline. salts suchas borate or aphosphate buffer or=with borax.

The liquor-wool :ratio may be varied over ea. wide range Withlno significant difierencesrinthe proportion of the wool wderivativeziormed. We prefer to employ liquor-wool ratios between about. 10 to land 40 toil.

The process f'isop'erative and reflective within a wide rangeoi temperatures. We prefer to carry out the "treatment" at temperatures between-about 60 C. -an'd.100"C.

The duration of the treating timemay-be-varied considerably. *Afterthe desired amount ofimod'ie fication :of the keratinousmaterialvhas occurred,- iurther treatment will not significantlyzchange the properties of thermodified keratin product. In general, treatment'for about one-half h'ourto one hour at 380 C. prziro'm-yabout one-quarter hour' to one hour-atfthe iboilgives goodresults;

With the proiuer-iameuht 70f alkylating agent present, thetnumber oi stabilized linkages that can be formed in :the'fiber will "depend'on'the'. concentration of reducing agent, "-theupll' of the solution and "the temperature and duration iiof the treatment. 1The 'keratinousprdductsitreated:

muss Kill iiiilli iUt in accordance with our invention exhibit significantly enhancedresistance to deterioration when exposed to oxidizing, reducing or alkaline agents. At the same time the mechanical properties of the wool are substantially unimpaired and are comparable to those of untreated Woo1..

It has been proposed to treat keratin with a reducing agent and subsequently to treatthe resulting product with an alkylating agent. This treatment, however, results in a product essentially diiferent from and markedly inferior to that obtained by our invention, when the same reducing agents are used. In the two-step process, deterioration of the fiber produced by the reducing agent persists in the final product to a substantial extent. Th subsequent treatment with an alkylating agent is not capable of restoring to the keratin its original properties.

While our invention is not limited to any theory of operation, it is suggested that the alkylating agent in the reducing solution, by forming stable linkages. immediately upon rupture of the disulfide linkages, preserves the physical properties of the material.

When keratinous material is treated with reducing agent alone, under the conditions of. our treatment, a substantial number of sulfhydryl groups is formed, as indicated by a strong nitroprusside reaction. The mechanical properties of wool so treated are markedly inferior to those of the untreated productits tensile strength is greatly weakened and the fabric becomes stiff and boardy. In our process, however, the detrimental effects noted with reducing agent alone are negligible.

Our process is capable of easy control. It is relatively insensitive to small variations in conditions such as temperature, concentration of reagents, time of treatment, etc. No damage is caused either by high concentrations of reducing agent or by unduly prolonged treatment.

We claim:

1. The process for modifying a keratino-us material to increase its resistance to attack by oxidizing agents, reducing agents and alkalis while preserving substantially unimpaired its mechanical properties, which comprises treating the keratinous material at a temperature between 60 C. and 100 C. and a pH above 7, in a liquid bath containing 3% to 100% of the weight of the keratinous material of a reducing agent for keratin which is inert to alkylene dihalides, to rupture disulfide across linkages of the keratinous material, said bath also containing morethan 0.00045 mol per gram of keratinous material'of an alkylene dihalide, whereby, new stable alkylene cross linkages between the peptide chains of the keratin are formed immediately. upon rupture of the disulfide linkages.

2. The method of stripping color from dyed wool while preserving substantially unimpaired the mechanical properties of the wool and increasing the resistance of the Wool to attack by oxidizing agents, reducing agents and alkalis, which comprises treating the wool at a temperature between C. and 100 C. and a pH above 7, in a liquid bath containing 3% to 100% of the weight of the wool of a reducing agent for keratin which is inert to alkylene dihalides and which is a stripping agent for dyestufi on wool, to rupture disulfide cross linkages of the wool and simultaneously strip the dyestufi, said bath also containing more than 0.00045 mol per gram of wool of an alkylene dihalide; whereby new tide chains ofthe woolare formedimmediately upon rupture of the disulfide linkages. 7

H3. The method of removing color from wool while presenving substantially unimpaired the mechanical properties of the wool and increasing the resistance of the wool to attack by oxidizing agents, reducing agents and alkalis which comprises treating the wool at a temperature between 60C. and C. and a pH above 7, ins, liquid bath containing 3% to 100% of the Weight of the wool of a keratin reducing agent selected from the class consisting of sulfoxylate formaldehyde compounds, hydrosulfites and f ormamidine sulfinic acid, to rupture disulfide cross linkages of the wool and simultaneously remove color, said bath also containing more than 0.00045 mol per gram of wool of an alkylene dihalide, whereby new stable alkylene cross linkages between the peptide chains of the wool are formed immediately upon rupture of the disulfide linkages. i

4. The method of stripping color from dyed wool while preserving substantially unimpaired the mechanical properties of the wool and increasing the resistance of the wool to attack by oxidizing agents, reducing agents and alkalis, which comprises treating the wool at a temperature between 60 C. and 100 C. and a pH above 7, in a liquid bath containing 3% to 100% of the Weight of the wool of a keratin reducing agent which is a dyestufi stripping agent selected from the class consisting of sulfoxylate formaldehyde compounds, hydrosulfites and formamidine sulfinic acid, to rupture disulfide cross linkages of the wool and simultaneously strip the dyestufi, said bath also containing more than 0.00045 mol per gram of wool of 1,2-dibromoethane, whereby new stable alkylene cross linkages between the peptide chains of the wool are formed immediately upon rupture of the disulfide linkages.

5. The method of stripping color from dyed wool while preserving substantially unimpaired the mechanical properties of the wool and increasing the resistance of the wool to attack by oxidizing agents, reducing agents and alkalis, which comprises scouring the wool with 2% to 5% of its weight of ammonia at a temperature between 50 C. and 60 C. and then treating the wool for from hour to 1 hour at a temperature between 60 and 100 C. and a pH above 7, in a liquid bath containing 3% to 100% of the weight of the wool of a reducing agent selected from the class consisting of sulfoxylate formaldehdyde compounds, hydrosulfites and formamidine sulfinic acid, to rupture disulfide cross linkages of the wool and simultaneously strip the dyestuii, said bath also containing more than 0.00045 mol per gram of wool of an alkylene dihalide, whereby new-stable alkylene cross linkages between the peptide chains of the wool are formed immediately upon rupture of the disulfide linkages.

6. The method of removing color from wool while preserving substantially unimpaired the mechanical properties of the wool and increasing the resistance of the wool to attack by oxidizing agents, reducing agents and alkalis which comprises treating the wool at a temperature between 60 C. and 100 C. and. a pH above 7, in a liquid bath containing 3% to 100% of the weight of the wool of sodium sulfoxylate formaldehyde, to rupture disulfide cross linkages of the wool and simultaneously remove color, said bath also containing more than 0.00045 mol per gram of wool ofan alkylene dihalide, whereby new stable alkylene cross linkages between the pep- 1 stable alkylene cross linkages between the pep,

RQQit tide' chmns ()Nihe Wo61' "are iofmdifififidihtefy upon ruptureef th'e' fl istfifide'iirikegesr 7. The method bfrein'o'vin'g @0101 mm wool while preserving slibstantia'liy uni' 'mpaired the mechanical properti'es' of the W001 andincreaving the resistance-DY the W001 teattabkby oxidiz ing agents} reducing agents anflmlkalij Whieh comprise's treating the W601 hth temperature between 60' C. and 100 C; and a/pH zitvtimri 7 ,''in a liquid bath cor itaining -3%-- to 100% oT bh'e weight of "the wool-0f sodium 'hydrosfilflfit'e to rupture diSuIfide cre's' linkages 6f the wool-find simultaneously remove colbrfsaid belth "32186- 1261?- tamingmo're than 0.00045 moi-per gram ef wbel of an -alky1ene-diha,1ide, whereby new stable alkylene linkages between me peptide chains of the W601 are formed immediately upen rupture of the distilfid linkages. '8. The method of removing 60161- -from W601 While preserving "substantially hhimiifiird the mechanical properties of the wool gnd increasing the resistance of the W001 to-attack by oxidizing agefits,-reducing agents and alkal is, which com pri'ses treating the wool elt & iaemperasurebetw'en 60 C. and 100 C-. and-a pH above 7, in a liquid bath containin'g-3% $0 100% of the Weight'df the

Claims (1)

1. THE PROCESS FOR MODIFYING A KERATINOUS MATERIAL TO INCREASE ITS RESISTANCE TO ATTACK BY OXIDIZING AGENTS, REDUCING AGENTS AND ALKALIS WHILE PRESERVING SUBSTNATIALLY UNIMPAIRED ITS MECHANICAL PROPERTIES, WHICH COMPRISES TREATING THE KERATINOUS MATERIAL AT A TEMPERATURE BETWEEN 60*C. AND 100*C. AND A PH ABOVE 7, IN A LIQUID BATH CONTAINING 3% TO 100% OF THE WEIGHT OF THE KERATINOUS MATERIAL OF A REDUCING AGENT FOR KERATIN WHICH IS INERT TO ALKYLENE DIAHALIDES, TO RUPTURE DISULFIDE ACROSS LINKAGES OF THE KERATINOUS MATERIAL, SAID BATH ALSO CONTAINING MORE THAN 0.00045 MOL PER GRAM OF KERATINOUS MATERIAL OF AN ALKYLENE DIHALIDE, WHEREBY NEW STABLE ALKYLENE CROSS LINKAGES BETWEEN THE PEPTIDE AND CHAINS OF THE KERATIN ARE FORMED IMMEDIATELY UPON RUPTURE OF THE DISULFIDE LINKAGES.