this portion of the application includes sections entitled , definitions , compounds and their methods of preparation , and hair - treating methods and compositions . the term &# 34 ; conditioning &# 34 ;, as it applies to keratinous fiber such as hair , denotes textural properties of smoothness , softness , combability and the absence of static buildup . other properties recognized as characteristic of &# 34 ; conditioning &# 34 ; are known to those skilled in the art . the term &# 34 ; alkyl &# 34 ; means an aliphatic hydrocarbon including about one to about eight carbon atoms in the chain which can be either straight or branched . the preferred alkyl groups are lower alkyl groups which include about one to about four carbon atoms . the term &# 34 ; fatty alkyl &# 34 ; means an aliphatic hydrocarbon group including about eleven to about twenty two carbon atoms in the chain which can be either straight or branched . the term &# 34 ; reducing agent &# 34 ; means a material which provides a source of electrons or hydrogen . in the context of the present invention , a reducing agent permits the cleavage of disulfide bonds in keratinous fiber to form mercaptyl groups . the term &# 34 ; oxidizing agent &# 34 ; means a material which promotes the oxidative bonding of mercaptyl groups to form disulfide bonds . exemplary oxidizing agents include hydrogen peroxide and sodium bromate . x - is an anion that is non - toxic to human and animal skin and scalp . preferred anions include chloride , bromide , sulfate , bicarbonate , acetate , lactate , and phosphate . the compounds , methods for their preparation and examples of the preparation of specific compounds of this invention are described in the next section . a class of compounds of formula i , which is of particular use in the hair - dyeing method described in more detail below , comprises compounds where r 2 is a substituent group which is capable of exhibiting a visible color chromophore in oxidized form and thereby capable of imparting color to hair . a particularly preferred hair - coloring moiety has the formula wherein : c is 0 or 1 ; r 9 is hydrogen , phenyl , lower alkyl or hydroxy lower alkyl ; and z is phenyl substituted by one or more substituents selected from the group including amino , alkylamino , phenylamino , hydroxyalkyl , hydroxy , chloro , methoxy and nitro . a most preferred class of substituent groups include a z --( nr 9 ) c moiety which may be described as 4 - aminoanilino , 2 - methyl - 5 - aminoanilino , 3 - methyl - 4 - aminoanilino , m -, o - and p - hydroxyanilino , 4 - nitro - 2 - aminoaniline , 4 - chloro - 2 - aminoaniline , 2 - aminoanilino , 2 - chloro - 4 - aminoanilino , 4 - amino - 2 - chloro - 5 - methoxyanilino , 4 - amino - n - phenylanilino , 4 - amino - 3 - nitro - n - phenylanilino , 4 - amino - n - methylanilino , 4 - amino - 2 , 6 - dichloroanilino , 4 - amino - 2 - nitroanilino , 4 -( bis - 2 - hydroxyethyl ) amine - 2 - nitro - n - methylanilino , 4 -( bis - 2 - hydroxyethyl ) amine - 2 - nitro - n -( 2 - hydroxyethyl ) anilino , 4 - amino - 2 - nitro - n -( 2 - hydroxyethyl ) anilino , 2 - nitro - n -( 2 - hydroxyethyl ) anilino , 2 - amino - 4 - nitro - n -[ tris ( hydroxymethyl ) methyl ] anilino , and 2 - amino - 4 - nitro - n -( 2 - hydroxyethyl )- anilino , when c is 1 , and phenyl - 2 , 5 - diamine , phenyl - 3 , 4 - diamine , catechol , pyrogallol or resorcinol when c is 0 . other classes of compounds within the scope of formula i , which are particularly useful for imparting additional permanent properties , such as sheen and lubricity properties , to hair treated therewith according to the method of this invention , comprise compounds wherein r 3 is : r 4 and r 5 are each independently lower alkyl , phenyl , phenyl lower alkyl , styryl or -- osi ( r 6 )( r 7 )( r 8 ); and r 6 , r 7 , and r 8 are each independently lower alkyl ; and ( b ) r 3 is hydroxy polyoxyalkylene alkyl of the formula compounds according to the present invention may be prepared by the reaction of an n - alkylation agent with an appropriate amine intermediate containing a mercaptyl group . a preferred method involves the n - alkylation of a tertiary amine intermediate . compounds of formula i where a is 1 , which are particularly preferred in view of the increased stability of the amido functionality , may be prepared using an intermediate which is the product of a mercaptyl - containing carboxylic acid or - carboxylic ester and an n - aminoalkyl tertiary amine reacted under appropriate amide - forming or ester - amide interchange conditions . this reaction sequence is depicted in scheme i below . ## str2 ## wherein the variables m , n , a , r 1 , r 2 , r 3 are as defined for formula i above . diamino compounds shown in scheme i above are available commercially or may be prepared according to methods known in the literature . compounds including r 1 and / or r 2 substiutent groups other than hydrogen may be prepared by selectively n - alkylating the unsubstituted diamine or by reducing the analogous nitro compound . n - alklating agents may include compounds such as alkyl halides or sulfonates , and such agents wherein the alkyl group is substituted with a polysiloxy or polyalkyloxy group . mercaptyl - containing compounds shown in scheme i above are available commercially or may be may be prepared according to known literature methods . compounds of formula i where a is 0 may be prepared also by the n - alkylation of a tertiary amine intermediate which is the product of a secondary amine and a mercaptylalkyl halide . another means for preparing these compounds which does not include the amido functionality involves the reaction of an appropr - iate alkyl mercaptyl reagent , such as a mercaptyl - containing alkyl halide , with a tertiary amine . this reaction sequence , shown in scheme ii below , is also an alternative route to the preparation of the amido - containing compounds , where an appropriate tertiary amine is reacted with an n - alkylating amidomer - captyl - containing compound . ## str3 ## where l is a leaving group such as bromo , chloro , sulfonate , and m , n , a , r 1 , r 2 , r 3 are as defined above . a mixture of 3 - dimethylaminopropylamine ( 60 g ) and ® thyl thioglycolate ( 60 g ) in methanol ( 125 ml ) is stirred at rt for one hour . bromoethane ( 60 g ) is added to the stirred mixture which is refluxed for 1 . 5 hours . the methanol in the reaction mixture is distilled away leaving the desired product as an oily residue . ir spectra ( neat )( cm - 1 ): 3420 ( s ), 3240 ( s ), 2960 ( s ), ( m ), 2510 ( w ), 2480 ( w ), 1710 ( s ), 1540 ( s ), 1465 ( s ). a mixture of 3 - dimethylaminopropylamine ( 30 g ) and ethyl thioglycolate ( 30 g ) in methanol ( 60 ml ) is stirred at rt for 1 . 5 hours . methyl iodide ( 80 g ) is added to the stirred mixture which is refluxed for 2 hours . the methanol in the reaction 1 . 5 mixture is removed under vacuo leaving 106 g of the desired product as an oil . lr spectra ( neat )( cm - 1 ): 3440 ( s ), 3260 ( s ), 2960 ( bs ), 2700 ( s ), 2510 ( w ), 2460 ( w ), 1725 ( m ), 1650 ( s ), 1540 ( s ), 1480 ( s ). a mixture of 3 - dimethylaminopropylamine ( 30 g ) and ethyl thioglycolate ( 30 g ) in methanol ( 60 ml ) is stirred at rt for 4 hours . the methanol is removed under vacuo and toluene ( 85 g ) and 1 - bromododecane ( 80 g ) are added to the residue . the reaction mixture is refluxed for about three hours and the toluene is removed under vacuo . the resulting desired product solidified slowly to a yellow waxy material . ir spectra ( neat ) ( cm - 1 ): 3420 ( m ), 3240 ( s ), 2920 ( bs ), 2680 ( s ), 25i0 ( w ), 2470 ( w ), 1725 ( w ), 1665 ( s ), 1645 ( s ), 1540 ( s ), 1465 ( s ). a mixture of 3 - dimethylaminopropylamine ( 70 g ) and methyl 3 - mercaptopropionate ( 60 g ) is stirred under vacuum at temperature of about 85 ° c . for about three hours . the reaction residue comprises the amide intermediate . ir spectra ( neat )( cm - 1 ): 3290 ( s ), 3075 ( m ), 2940 ( s ), 2860 ( s ), 2810 ( s ), 2760 ( s ), 2580 - 2400 ( w ), 1690 ( s ), 1575 ( s ), 1460 ( s ). ethyl bromide ( 23 g ) in toluene is added to about 30 grams of the reaction mixture residue and the mixture is refluxed , the toluene removed under vacuum , and the desired product obtained as an oil . mercaptyl - containing quaternary nitrogen compounds described above may be used in the hair treating methods and the hair treating compositions described below . the compounds of the present invention can be used to impart permanent conditioning and shaping , for example , curling or straightening , to keratinous fiber . the permanent conditioning properties are believed to result from the chemical binding of the quaternary group derived from the mercaptyl - containing quaternary nitrogen compound of formula i to keratin by means of disulfide bonds . such bonded chemical groups remain on the hair keratin and are not removed by shampooing . of course ., as new hair grows from the scalp , hair fiber which is not chemically bound to compounds of formula i will diminish the conditioning properties achieved by the present invention . accordingly , it should be understood that periodic treatment of hair with a compound of the present invention will be required to maintain the permanent conditioning effect . one aspect of the present invention comprises contacting hair with a reducing agent followed by the mercaptyl - containing quaternary nitrogen compound and an oxidizing agent . the reducing agent can either remain on the hair or be rinsed from the hair prior to the application of the mercaptyl - containing quaternary compound . reducing agents and reducing compositions , which are known to persons skilled in the art , can be used . the reducing agent is applied typically to the hair in the form of an aqueous composition including , for example , ammonium monothioglycolate or glyceryl monothioglycolate , for a time which is effective for reducing a substantial number of disulfide bonds . typical times are from about 5 to about 20 minutes at temperatures of about room temperature to about 110 ° f . oxidizing conditions which are known to persons skilled in the art may be used in the present method of hair treatment . the oxidizing conditions may involve exposure to atmospheric or concentrated oxygen or result from the application of a fluid composition including an oxidizing agent to the hair . the oxidizing agent is chosen from those used typically in the art such as hydrogen peroxide and sodium bromate . it is applied preferably in the form of aqueous solutions and is allowed to remain on the hair for a time which is effective to regenerate a substantial number of the reduced disulfide bonds . typical application times are from about 5 to about 20 minutes at temperatures from room temperature to about 110 ° f . the oxidizing agent is rinsed from the hair using tap water or a rinse product known to the art . a preferred rinse composition comprises an acidic aqueous composition having a ph of about 4 . 5 to about 6 . 5 . another aspect of the present development is a method for permanently conditioning and shaping hair comprising the steps of : ( 1 ) contacting hair with an aqueous composition comprising a compound according to formula i above in the presence of a mercaptyl - disulfide interchange catalyst ; and the mercaptyl - disulfide interchange catalyst is a material which , in the presence of protein disulfide groups and free non - protein mercaptyl groups , will promote the cleavage of the disulfide bonds and permit the recombination of protein mercaptyl groups and free mercaptyl groups to form disulfide bonds which link protein and non - protein mercaptyl compounds . one such catalyst is thioredoxin , which is an enzyme protein . u . s . pat . no . 4 , 738 , 841 disclosed thioredoxin and equivalent enzymes . the concentration of thioredoxin in the composition is about 1 nmole / ml to about 100 nmole / ml . although the compound of formula i contains free mercaptyl groups which may participate in the reduction of the disulfide bonds to free mercaptyl groups , it is preferred that the composition in the foregoing method containing an additional source of reducing material such as described herein above . the most preferred materials include glyceryl monothioglycolate and bisulfite salts such as sodium , potassium and ammonium bisulfite . the mercaptyl - disulfide catalyst and quaternary compound are permitted to remain on the hair for an amount of time sufficient to cleave a substantial amount of the disulfide bonds in the hair . a preferred time is about 2 to about 15 minutes at a temperature from room temperature to about 90 ° f . it is preferred that this method be practiced by subjecting hair treated according to step ( 1 ) to oxidizing conditions as described above prior to rinsing the mercaptyl - containing quaternary nitrogen compound from the hair . it is believed that this improves the opportunity for the mercaptyl - containing quaternary nitrogen compound to participate in the disulfide formation and thereby chemically bind to keratin . the present invention may also be used to impart other permanent properties , for example , sheen , water and humidity resistance and / or color , to treated keratinous fiber by the suitable choice of a compound of formula i having particular substituent groups as described herein and / or use of special embodiments of the present method . one such embodiment relates to the dyeing of keratinous fiber , wherein the dye - complexing properties of the quaternary nitrogen compounds of formula i are exploited . this involves introducing the quaternary nitrogen group into the chemical structure of the keratinous fiber by contacting said fiber with a composition containing a mercaptyl - containing quaternary nitrogen compound , subjecting such fiber to oxidizing conditions and contacting fiber containing the chemically bound quaternary groups with a hair dye capable of complexing with the quaternary moiety . exemplary dyes that can be used in this method include disperse black 9 , disperse blue 3 , direct red 81 , and acid red 95 . a further embodiment of the method aspects of the present invention relates to the permanent dyeing of keratinous fiber comprising the steps of : ( 1 ) contacting said fiber with a composition containing a mercaptyl - containing quaternary nitrogen compound which also contains a moiety capable of imparting color to said fiber under oxidizing conditions ; and another aspect of the present invention encompasses a hairtreating composition comprising a mercaptyl - containing quaternary nitrogen compound of formula i . the composition can be aqueous or nonaqueous and be in the form of a solution , a gel or a concentrate which can be mixed shortly prior to use . preferred compositions are aqueous and may include also nonaqueous fluid materials which are soluble , miscible or dispersible in water and which are generally recognized as nontoxic to skin and scalp . exemplary materials include ethanol , isopropanol , butanol , benzyl alcohol and other co - solvents , and propellant gases such as carbon dioxide , nitrous oxide , and fluorinated and / or chlorinated hydrocarbons . the amounts of the additional fluid materials included in the compositions of this development can be determined by those skilled in the art and can vary depending on the composition &# 39 ; s intended use . the mercaptyl - containing compound is present in the composition in an amount which depends also on the composition &# 39 ; s intended use and which is effective to impart to keratinous fiber the desired properties . typical amounts of compound will be about 0 . 1 to about 30 weight percent based on the total weight of the composition . in compositions used for the permanent waving of hair into tight curls , the mercaptyl - containing compound comprises about 5 to about 30 weight percent based on the total weight of the composition . in compositions where only permanent conditioning properties are to be imparted to the hair , the mercaptyl - containing compound comprises about 0 . 1 to about 2 weight percent based on the total weight of the composition . in compositions where a dye complex is formed with the quaternary compound , the mercaptyl - containing compound may comprise 0 . 1 to 15 weight percent of the composition . the preferred amount of quaternary compound included in a dye composition will be up to the formulist who will determine a particular dye system specific for a particular desired type and color of hair . a particularly preferred composition includes also a mercaptyl - disulfide bond interchange catalyst , which can be thioredoxin or analogue thereof . the concentration of thioredoxin in the composition is about 1 to about 100 nmole / ml . a preferred concentration is about 5 to about 25 nmole / ml of composition . a most preferred composition includes also a reducing agent such as glyceryl monothioglycolate or a bisulfite salt . the reducing agent may comprise about 1 to about 20 percent of the total weight of the composition . a preferred amount of reducing agent is about 2 to about 8 weight percent of the composition . it should be understood that the formulation of the present composition into a commercially acceptable composition may involve the inclusion of additional optional ingredients such as fragrances , thickeners , preservatives , stabilizers , emulsifiers , the nature and amounts of which are within the skill of the art . the following examples illustrate the practice of hair treating methods of the present invention . the hair treated in examples 6 to 9 comprise tresses of dark brown virgin human hair ( 11 inches in length ). a hair tress is wrapped on a curling rod which is submerged for 20 mins at 50 ° c . in an aqueous solution having a ph of about 9 and containing 5 % of the mercapto - quaternary compound bf example 1 above . the hair is removed from the solution , damp dried , submerged at rt in a 10 % aqueous solution of sodium bromate ( ph of 6 ) for 5 mins , removed from the solution , shampooed twice and air dried . a hair tress is wrapped on a curling rod and is treated with an aqueous solution of glyceryl monothioglycolate ( gmtg ). the hair is removed from the solution , damp dried and submerged in an aqueous solution of the mercapto - quaternary compound of example 1 above for 20 mins . the hair is removed from the solution , damp dried without a rinse and submerged at rt in a 10 % solution ( ph of 6 ) of sodium bromate for 5 mins . the hair is rinsed free of bromate solution , shampooed twice and air dried . a hair tress wrapped on a curling rod is submerged for 20 mins at 50 ° c . in a shaken composition containing 30 ml of a 5 % aqueous solution of the mercapto - quaternary compound of example 1 above , sodium bisulfite ( 5 g ), butanol ( 20 ml ), ethyl alcohol ( 25 ml ) and water ( 25 ml ). the hair is removed from the composition , damp dried without a rinse and submerged for 5 min in a neutralizing solution containing 10 % sodium bromate in a mixture of water : ethanol : butanol ( 50 : 25 : 25 ). the hair is rinsed free of bromate solution , shampooed twice and air dried . a tress of hair was treated according to the procedure described in example 6 except that gmtg was used as control . after drying , the hair treated according to each of the aforementioned examples is unwound from the curling rods and the curl - length , curl pattern and softness of the hair is evaluated . the results are presented below . ______________________________________example no . hair length hair turns comment______________________________________untreated 11 in . 6 8 in . 11 / 2 very soft curl7 4 in . 8 6 in . 4c - 1 2 in . 61 / 2 very tight curl______________________________________ the procedures of the aforementioned examples are repeated using virgin blond hair , and the treated hair is submerged in a 0 . 1 % aqueous solution ( ph of 6 ) brilliant vital red dye for 15 min . at rt , rinsed under running tap water , shampooed twice with ammonium lauryl sulfate solution , washed with methanol , washed with dmso , rinsed under water , and washed again with dmso . the color density of the treated hair is measured on a relative scale and the results are presented below . ______________________________________example no . observation color intensity______________________________________no treatment no color 0c - 1 &# 39 ; very slight color 0 . 56 &# 39 ; slightly more color 1 . 57 &# 39 ; some color 28 &# 39 ; most color 5______________________________________ the results of the aforementioned examples demonstrate that hair treated with the mercapto - containing quaternary compound of formula i is chemically bonded thereto and has imparted thereto permanent conditioning properties . the test results demonstrate also that hair treated with the quaternary compounds of this . invention are capable of permanently complexing significant amounts of dye even after shampoo treatment .
mercaptyl - containing quaternary nitrogen compounds , which may contain additional functional moieties such as dye , polysiloxane , or polyoxyalkylenes groups , are useful in the treatment of hair , used in hair - treating compositions , to impart properties such as conditioning , shape , color , sheen , and manageability .