DE1619064A1 - Process for the chemical change of keratin-containing fibers and solid preparation for this - Google Patents

Description

■ Tile Sill et te Company 2 0. SER 1965

Boston, Mass., USA 161906 ^ »

Process for the chemical modification of keratin-containing fibers and solid preparation for this

The invention "relates to a method for chemical Change of keratinous pastes and one for this suitable solid! preparation. This change can be used to remove hair or roll to make it resistant to matting and shrinking during washing or to facilitate the coloring of these fibers.

The keratin-containing fibers which can be treated according to the invention encircle both human and animal hair, ζ.3. Wool and textile goods made from it.

The method and preparation according to the invention enable softening or dissolving of keratin-containing fibers under mild conditions, i.e. at moderate temperatures and without having to use strong alkali.

According to the invention it was found that practically

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V / water-free dry mixtures of water-soluble reducing agents in the form of sulfites, 3isulfites or hydrosulfites and water-soluble oxidizing agents in the form of -Tri-, Tetra, penta or hexathicnates after dissolving in one aqueous medium at normal or elevated temperature with keratin-containing fibers with conversion of the disulfide bonds of the keratin in the S-sulfofrom and at the same time Able to implement fiber accumulation and softening.

The substances that can be used according to the invention include the ammonium, alkali metal and the mono-, di- or iri-lower alkanolamine salts of the aforementioned anions. The mixture can consist of compounds with the same or different Cations exist.

With the help of the invention is the extent of the possible fiber conversion far higher than with hair treatment with the reducing agent alone. The preparation according to the invention is non-toxic, whether it is in dry-form or applied to the skin in solution or suspension. The dry preparations are very stable and can be Long-term storage, but become comparatively unstable after adding water in the form of a solution or slurry and must then no longer be kept for long before use will.

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original

The mechanism of the reaction may be difficult to understand but - without being bound by this assumption - might consist of that {Detra-, Penta- and Hexathionat each under consumption of one, two or three moles of sulfite according to the general equation

S _n O ₆ "" + (n-3) SO ₅ "~ '^ = - S ₅ O ₆ ""+ Cn-J) S ₂ O ₃ ""

pass into the irithionate. The reaction probably takes place between the irithionate and the reducing agent only slowly, but the latter settles with the disulfide bonds in the hair with the formation of an S-SuIfo- and one thiol group per bond around, and the! drithionate oxidizes any thiol group so formed to the disulfide form return"

The quantity ratio between reducing agent and oxidizing agent can be varied to a large extent; If, for example, only sulfite and trithionate are present, any excess of irithionate over the sulfite is of no practical use, if the mixture contains, in addition to sulfite, letra or higher polythionate, some sulfite reacts with the polythionate, so that only the remainder with the keratin can react, and under these circumstances the reducing agent is preferably used in excess. For the purpose of

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For best results, generally 0.05 to 2 and preferably 0.05 should be used per mole of reducing agent up to 1 mole of oxidizing agent may be present, with after As stated earlier, in the presence of an oxidizing agent other than trithionate, correspondingly excess reducing agent should be present.

Also the concentration of reducing and oxidizing agents in the aqueous dissolution or slurry is largely variable. In general, the approach can be 0.1 to 4 mol of reducing agent per liter and - as I said ije Moles of the latter contain 0.05 to 2 moles of oxidizing agent. Its pH value can be between 4.5 and 11, with the reaction being fastest in the area between 6 and 7 runs. If you want to make wool shrink-free or easier to dye with the invention, you subjugate it Keratin fibers, preferably a short treatment at a pH value above 8, in order to remove as many disulfide bonds as possible to convert in the fiber outer zones and as few of them as possible inside the fiber. On the other hand, if you have a have uniform conversion of the whole keratinous fiber the best results are obtained with a longer fiber treatment at a pH value of 8 and below Any desired pH adjustment is possible with any alkaline material possible, but happens

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usually, preferably with ammonium hydroxide. If so desired you can keep the pH in the desired range with any conventional buffer salt.

Protein swelling agents such as urea, Isopropanol, lithium bromide, phenol -, add, which then both the formation speed of the Increase S-sulfo groups as well as promote the swelling of the keratin fibers. If "is used, you can depending on your Type and desired performance in an amount of usually up to 8 moles and preferably 1 to 8 moles per mole Reducing agent be present. Overflows can become your own Insolubility or salting out of other ingredients to lead. If the preparation is to be used for depilating human or animal skin, it is present such swelling agents are particularly useful.

On the other hand, such as when removing the shrinkage of wool, the preparation should only have a superficial effect on the keratin fibers, you can use a swelling agent for it, for example a water-soluble salt such as sodium chloride, potassium chloride, sodium sulfate, magnesium sulfate or the like, add to the oxidizing agent, the Reducing agents and the hair keratin chemically behaves neutrally. This is used depending on

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the type of salt and the desired performance in general up to 4 moles and preferably 0.5 to 4 moles per one Moles of reducing agent.

In the case of use, the preparation is first mixed into the aqueous medium and then applied to the keratin fibers at a temperature that can be normal or elevated and, in the case of animal skin depilation or shrinkage removal of wool, can reach the boiling point of the solution. But in general is carried out at room temperature up to about 4O ⁰ C.

The process according to the invention leads to in one step and without the use of metal catalysts a high level of S-SuIfo (i.e. -S-SO, -) groups in the Pasers. The stable, dry ceratin fiber obtained in this way is practically metal-free and by breaking it open • from 10 to 70 $ of their disulfide bonds and formation of -S-SO, groups modified in its chemical composition. This increases their ability to absorb and dye their shape retention strengthens.

If you use the preparations according to the invention for the depilation of animal or human skin, you simply keep them in aqueous medium in contact with the keratin fibers,

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until these are so swollen and softened that they can be removed by gently rubbing or scraping the support can remove.

The following examples are intended to illustrate the invention without Explain the limitation of the scope of protection in more detail.

example 1

A number of aqueous solutions were made those in relation to ammonium bisulfite per 1 molar, in relation to on sodium tetrathionate according to the table below molar and adjusted to pH 7 using ammonium hydroxide. In 50 ml samples of these solutions 1 g of brown European hair was immersed for 30 minutes at 35 ° C. After taking them out again the individual hair samples for 5 minutes with flowing Water washed, with most of the remaining pairs of thiol and S-sulfo groups forming Disulfide bonds reunited. It was then determined how many S-sulfo groups without being converted back into Disulfide bonds in the keratin fiber remained by one first of all still, remaining thiol groups through Immersing the hair for 15 minutes in a molar aqueous acrylonitrile solution of pH 9 »2 alkylated and

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then through the hair, dipping in for two hours 25 ecm 1O5 ° G hot 3O ^ ige sulfuric acid hydrolyzed, to convert the remaining S-sulfo groups into thiol groups, then their concentration by titration using an organomercury salyrganic acid compound was determined by nitroprusside sodium as an indicator. The title thus established was in the following Table in milliequivalents (by diluting the solution) irreversible S-suIfo groups per g hair.

Molar concentration of
Sodium tetrathionate Irreversible S-SuIfo-
groups 0.0 0.08 0.2 0.65 0.4 0.68 0.6 0.63 0.8 0.42 1.0 0.22

The tables clearly show that even the presence of only a little sodium tetrathionate in the solution leads to a considerable increase in the number of irreversible S-sulfo groups in the keratin fiber and the effectiveness of the mixture decreases as soon as the amount of thionate increases approaches the amount of bisulfite. But even with molar the same

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chem content of reducing agents and oxidizing agents is effective the Öemisch solution is still much stronger than just one the reducing agent-containing solution because the reaction there is and always something between sodium tetrathionate and ammonium bisulfite Bisulfite available for conversion with the hair keratin lets stay.

Example 2

The procedure of Example 1 was followed with the modification repeats that instead of the [eetrathionate, sodium trithionate was used. The results obtained in this way are shown in the table below:

Molar concentration of the irreversible S-sulfo sodium trithionate groups

0.0 0.08 0.1 0.56 0.2 0.77 0.3 0.81 0.4 0.84 0.5 0.86 0.75 0.89 1.0 0.88

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These results clearly show that there is already a small amount of sodium trithionate in the aqueous solution a very strong increase in the proportion of keratin fibers formed, irreversible S-sulfo groups result and the effectiveness of the mixture also does not decrease when the amount of sodium trithionate is greater than the amount of reducing agent approaching.

Example 3

In this further repetition of Example 1, sodium pentathionate was used instead of sodium tetrathionate worked. The table below shows the results obtained

Molar concentration of the
Sodium pentathionate Irreversible S-SuIfo-
groups 0.0 0.08 0.2 0.50 0.5 0.65

This shows the superior effectiveness of the aqueous mixture solution compared to an aqueous solution the reducing agent alone.

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. Example 4-

By. Dissolving a sodium hydrosulphite / sodium trithionate mixture in water produced a solution that was 0.6 molar in relation to hydrosulphite and 0.2 molar in relation to irithionate, "in which the molar ratio of oxidizing agent to reducing agent was about 0.53 to 1" «. In 50 7 set and held at 35 ⁰ C ecm means of ammonium hydroxide to a pH value of solution was added 1 g "brown European hair immersed for 6 hours, rinsed after searching out with water and Example 1 investigates-SuIfogruppen S according to content of irreversible. 0.69 milliequivalents per gram were found.

Example 5

50 millimoles each, ie 13.5 g sodium tetrathionate, 6.1 g sodium sulfate and 5-4 g sodium bisulfite were rubbed together and stored in a loosely covered container. This mixture of fine particles was then dissolved in water to make 100 ml of a pH 7 solution. In the content at 35 ⁰ C eneiLösung 1 g of brown European hair was soaked for 30 minutes. After removal and rinsing, the hair treated in this way contained 0.33 milli-equivalent irreversible S-sulfo groups per gram.

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In an experiment carried out accordingly with 12.0 g (50 millimoles) of sodium trithionate instead of the tetrathionate became 0.72 milliequivalents of irreversible S-sulfo groups determined per gram of hair.

Example 6

An aqueous solution related to ammonium sulfite 0.6 molar, 0.2 molar for sodium tetrathionate and 3 molar for urea, was taken in 50 ml portions adjusted to various pH values given in the table below by means of ammonium hydroxide. In the individual portions, kept at 35 ° C., were immersed in each case 1 g of brown European hair for 10 minutes and then as in Example 1 examined for its content of irreversible S-sulfo groups. The results are in the given in the table below.

PH value Irreversible S-SuIfo groups 7.0 0.24 8.0 0.29 9.0 0.26 9.7 0.25

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When the irreversible S-sulfo groups were essentially equally strong, a microscopic examination revealed the keratin fibers that the solutions with a higher pH penetrated more slowly into the fiber interior.

Example 7

50 ml portions of an aqueous solution, which was 1 molar in relation to ammonium bisulfite and 0.5 molar in relation to sodium tetrathionate, were mixed with different amounts of keratin source according to the table below and adjusted to pH 7 with ammonium hydroxide. In each of the portions, kept at 35 ^° C., 1 g of brown European hair was immersed for 30 minutes and, after being removed, examined on the one hand for its content of irreversible S-sulfo groups and on the other hand, according to the standard method, for its degree of swelling in a buffer solution of pH 7. The results are given in the table below.

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Swelling agent Irreversible S-SuIfo groups untreated hair without addition o, 68 2 m urea 0.84 4 m urea 0.84 2 m isopropanol 0.85 4 m isopropanol 0.84

Swelling 31

131

172

340

177

213

As can be clearly seen, the swelling agent causes both an increased formation of irreversible S-sulfo groups as well as an increased breakdown of the keratin protein structure, which manifests itself in increased swelling capacity.

• Example 8

A solution which was 0.6 molar for ammonium bisulfite, 0.3 molar for sodium trithionate and 3 molar for urea was adjusted to pH 7 using ammonium hydroxide. A 76 × 76 mm piece of salted bull skin, which had previously been made salt-free by rinsing with water, was immersed for 45 minutes in this ^{solution, which was kept at 35 0 G.} The hair was then loosened so that it could be removed with a wooden scraper. This is in contrast to well-known

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th depilatory process that takes several hours to several days for an equally strong loosening of the hair fibers Require treatment.

Example. 9

An aqueous solution was prepared which was 1 molar for ammonium bisulfite and 1 molar for potassium trithionate 0.8 molar, and using ammonium hydroxide adjusted to pH 7. A piece of cotton gauze was soaked with this solution, one on the skin of the forearm Woman placed on top and covered with a plastic cover. After 20 minutes, the arm section treated in this way was able to escape the hair fibers pulled out with very little effort Vi earth.

Example 10

There were four aqueous solutions of the tabulated below specified composition prepared and each adjusted to the pH 9.6. Small squares made of uncolored Wool flannel were each in a serving of different Solutions corresponding to 50 ml per 1 g of Planeil are immersed for 15 minutes in the solution kept at 35 ° C leave, after removing it carefully with water.

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rinsed and then with a 0.1 molar aqueous borax solution treated to those remaining in the keratin fiber To combine thiol groups with the S-sulfo groups. The so Treated flannel squares were then measured for size, by hand, with a 5% aqueous sodium oleate solution tumbled through and "again to the extent of shrinkage measured. The results obtained in this way are shown in the table below.

Molar solution composition Area shrinkage in i

sodium
sulfite Hatrium
trithionate Sodium-
tetrathionate potassium
chloride 8.8 A 0.5 0.2 nothing nothing 0.6 B 1.0 0.2 nothing nothing 0.6 G 1.0 0.2 nothing 3 0.7 D 1.0 nothing 0.2 nothing 29.2 untreated

All samples with sample 0 as the best were after the treatment satisfactory in terms of feel and appearance.

Example 11

An aqueous solution that was 1 molar for ammonium bisulfite and 0.2 molar for sodium trithionate ,

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was adjusted by means of ammonium hydroxide to pH 7, and divided into 100 ml portions, partly for 10 minutes O were and immersed part 30 minutes at 25 ⁰ C in the per 152 χ 152 nmr large Yierecke of undyed wool flannel at 55 ^0th The samples treated in this way were carefully rinsed with water and then treated with a 0.05% aqueous borax solution in order to reunite all of the thiol groups remaining in the εeratin fiber with the S-sulfo groups.

Sections of the. Planell samples treated in this way were dipped together with an untreated crown roll sample colored in solutions of basic and acidic dyes. In all cases the treated sample was compared to the Control sample colored more intensely.

Example 12

An aqueous solution which had been adjusted to pH 6 in terms of ammonium bisulfite 0.6 molar, in terms of sodium tetrathionate 0.3 molar and in terms of urea 0.3 molar and with aqueous ammonia was added in 50 ml portions divided into each of which 1 g of brown European hair was immersed at 35 G for a specified time »Each of these samples was immediately loaded with 1 η hydrochloric acid

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is the progression of the disruption reaction to prevent, and then hydrolyzed and analyzed for thiol content. The value thus obtained was expressed as Measure of the total extent of disulfide bond breakage in the keratin at the time of acid immersion, i.e. the present thiol and S-sulfo groups taken together, considered. The second pair specimen was with water rinsed out and treated according to example 1 with acrylonitrile before it is hydrolyzed and irreversible on any present S-SuIfogruppen was examined. The results obtained are listed in the following table.

Irreversible

Treatment time, total breakdown in S-sulfo groups in minutes, mill equivalents per g Mill equivalents per g

5 0.29 0.09 10 0.49 0.18 15th 0.58 0.28 22 1/2 0.68 0.37 30th 0.74 0.54

As you can see, under the conditions used here, the total break-up is faster than the formation at the beginning irreversible S-sulfo groups in front of you. After the first 10 to 15 minutes, however, the breakup slows down, while the formation of S-SuIfo groups at constant speed

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progress. After 30 minutes, about three quarters of the breakdown product is in the form of irreversible S-suIfo groups.

Example 13

1 g samples of brown European ^{hair were immersed for 10 minutes at 35 0} C in 50 ml portions of solutions, each 0.6 molar in relation to ammonium bisulfite, 0.2 molar in relation to sodium tetrathionate and 3 molar in relation to urea, but had been adjusted to various pH values with aqueous ammonia. They were examined for the total extent of fracture and the content of irreversible S-sulfo groups according to the method according to Examples 1 and 4 and gave the following results:

PH value Total breakdown in
Milliequivalents per g Irreversible
S-SuIfo groups in
Milliequivalents per g 7.0 0.44 0.24 8.0 0.36 0.29 9.0 0.30 0.26 9.7 0.25 0.25

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One recognizes from this that one "with a short treatment the Proportion of irreversible S-SuIfo groups in the total breakdown can vary by suitable choice of the pH of the reaction medium. With increasing pH it increases the speed of the total breakup decreases, but the proportion of irreversible S-suIfo groups increases.

The microscopic examination of the reaction process between the keratin fibers and the suIfit solutions showed that the slower reaction at higher pH values is accompanied by slower penetration of the reagent into the paser is.

Example 14-

An aqueous solution was prepared which was 1 molar in relation to ammonium bisulfite, 0.4 molar in relation to potassium tetrathionate and 4 molar in relation to urea, and adjusted to pH 8 by means of ammonia. A strand of European hair weighing 0.5 g was immersed in 10 ml of this 32 ^° C. solution for one hour, then carefully washed out with water and shampooed. Two further, similar tresses were treated with media of the same salt composition, but which were diluted with 1 or 2 volumes of water per volume of solution.

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Individual hairs were removed from each strand and divided in half into two sample duplicates. Every The sample was measured for the radius of curvature and then, when wet, was placed in a collar form 16 mm in diameter. From the knowledge of the original radius of curvature of the specimen and the shape diameter, it was possible to calculate how tight each sample was.

The fiber-filled molds were then held at 100% humidity for 1 hour and at 32 % relative humidity for an additional 18 hours to shape the fibers. The hair was then removed from the mold, placed in an atmosphere of 65% relative humidity, and observed for an increase in the radius of curvature for 2 hours. The "Tension Ratio" reported in the table below is the tension retained by the fiber after two hours of relief divided by the tension applied. The higher this ratio, the greater the extent to which the hair fiber retained the tension imposed on it in the 16 mm fret shape.

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Concentration of
solution - Irreversible
S-SuIf ogroups Untreated control fiber Tension relationship Full strength 0.84 0.98 0.5 0.44 0.52 0.33 0.24 0.40 0.34

Obviously, as the content of irreversible increases sensitive S-SuIfo groups, the tension ratio is greater or, in other words, the shape of the hair improved.

Example 15

A slurry was prepared from 13.5 g (50 millimoles) of sodium tetrathionate, 6.1 g (50 millimoles) of sodium sulfite, 5.4 g of sodium bisulfite (50 millimoles) and 30.6 ml (400 millimoles) of isopropanol which resulted in in a stopper bottle ψ proved to be stable. Shortly before use, the slurry was brought to 100 ml total batch with a pH of 6.7 by adding water.

In this held at 35 ⁰ O solution 2 g of brown European hair was immersed for 30 minutes, to form S-SuIfogruppen "The hair was then rinsed and tested for swelling in a buffer at pH 7, which was 167 $.

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Keratin fibers treated according to the invention and * consisting thereof Textile goods can be rinsed with water and dried without loss of irreversible S-sulfo groups. Both retain their increased dye absorption capacity, their shape retention and their resistance to felting indefinitely. Are such fibers and textiles on the other hand with an aqueous solution of If only sulphite is treated, then they lose their S-sulpho groups again in contact with washing water take back the properties of untreated material at.

Such stable keratin fibers are those whose disulfide bonds broken down to $ 10 to $ 70 and into the so resulting end groups for at least $ 50 from irreversible S-SuIfogruppen exist, that is to say during the fiber treatment do not recombine with water with the thiol groups in the molecule. Since the method according to the invention without Metal catalyst is worked, are such fibers also metal-free.

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Claims (1)

Claim 1, fine particles l "ntßtolf preparation for the water-soluble β c heroic change keratin-containing fibers with a Keduktionemittel in advance BuIfit ·, bisulfites or hydrosulfites" gekennselehnet characterized in that it also a Xvdationßisittel in the form of y.asserlösliclten i'rl-, Tetre-, rente- or hexathionate in the ratio of f'ixyßatione to Beduktionetaittel between> 0? Γ. Preparation according to claim 1, characterized in »that en also a l "r» teiuanwellmittel i «i ^ olv« rhHltni · from cuell to lieduction means from 1 »1 to 8i1 contains. 5. The composition of claim 1 or? "By gekenns" leans that s still "in waee" rlÖBlich · ^ ^ ais ₉ I β the * ;; dationii- _t de 'Beduktione- and de "swelling agent behaves towards neutral, la Holvtraaltni «from iJeutraleals su heduktionmittel swiech ·« ⁽ _t 5i1 and 4: 1 contains. 009843/1729 bad 4. Process for the chemical change 70η kcratin-containing fibers "when they were brought into contact with a # 4-core Frtiparat" erdca, because a BecUiktione * agent in i'oivi a wasc soluble in i'uli'itsi, bisulfite ader Hjdroaulflts etithl * lt _t is characterized by the fact that iann «used in a preparation which also contains an xydation agent ia οτ.λ v-ai watery aliciien tri, tetra, perita or hexathionates xn . -olveriiiiltnie ψοη - to i.eiiuktionoiaittel sswiachea 'J5j1 and iulle of' Jrithiünüt jed.-cii bit au 2 * 1 up includes "the concentration en> £ fduktioneaittele -)» 1 to 4 <4ol per liter walked preparation. the procedure £ ewäu> iUiapiiich 4 wrapped keratin Γcitier, thereby marked "da; i olc Kievallfrei i" t and to 1 to 7? ' eufjebrociiene 'isulphide bonds aüf- «ei: t, vvobei the so entetandtuen ^ nu ^ ru ^ pea au aindenteue 5 v' iiurj irrevorr.ibleü i-Julx ^ ri ^ i ^ -en exist · BATH 009843/1729