DE4240425A1 - Use of nitro-substd. heterocyclic thione(s) as direct dyes - for natural or synthetic fibres, esp. human hair, giving fast, strong and levels orange to yellow shades - Google Patents

Abstract

Use of nitro-heterocycles of formula (I), and their salts, for dyeing natural and synthetic fibres is new. In the formula, R1 = H, OH, 1-4C alkyl, (CH2)xOR2 or halo; x = 2-4; R2 = H or 1-4C alkyl; n = 1-3; A = S or R3; R3 = H, 1-4C alkyl, (CH2)yOR4, phenyl or benzyl; y = 2-4; R4 = H or 1-4C alkyl. USE/ADVANTAGE - (I) are direct dyes for natural or synthetic fibres, e.g. silk, cotton, linen, wool, viscose, polyamide, polyester, polyacrylonitrile or polyurethane, but partic. keratin fibres, esp. human hair. (I) produce strong yellow to orange shades with very good exhaust and levelling properties, and good fastness to light, perspiration, washing, permanent waving, etc.

Description

The invention relates to the use of nitro-substituted He Terocyclen as a dye for fibers of natural origin and synthetic fibers and these nitro-substituted heterocycles Containing dyes for keratin fibers.

In the dyeing, the substantive dyes play a her prominent role.

For the purposes of the present invention is a direct-acting color fabric a dye, which can be obtained from one for each Coloring appropriate medium directly on the fiber raises.

The nitro dyes form an important group within the di rectifying dyes. Usually these have one or two attached to an aromatic ring nitro groups as Akzep torsubstituent (s) and one or two amino or hydroxyl groups as donor substituent (s) or auxochrome group (s).

The interaction of acceptor and donor substituents is for the Color of these compounds responsible. Additional batho chrome or hypsochromic shifts are achieved by as auxochromic groups alkyl, hydroxyalkyl, aminoalkyl or car boxyalkyl-substituted amino or hydroxyl groups used.

It has now been found that a group of nitro-substituted Heterocycles excellent for dyeing fibers natural ur and synthetic fibers, since they are high in color Color strength, wash, perspiration and light fastness result.

The invention therefore relates to the use of nitrosubsti tuierten heterocycles of the general formula I.

where R¹

• - hydrogen,
• a hydroxy group,
• an alkyl group having 1 to 4 C atoms,
• a group - (CH₂) _x - OR ² , where x is 2, 3 or 4 and R ^{2 is} hydrogen or an alkyl group having 1 to 4 C atoms, or
• - represents a halogen atom

and n is an integer from 1 to 3,
A represents a sulfur atom or a group NR ³ , where R ³

• - hydrogen,
• an alkyl group having 1 to 4 carbon atoms
• a group - (CH₂) _y - OR ⁴ , where y is 2, 3 or 4 and R ^{4 is} hydrogen or an alkyl group having 1 to 4 C atoms, or
• - represents a phenyl or benzyl group

or their salts for dyeing fibers of natural origin and synthetic fibers. With regard to possible tautomeric forms not to restrict the general formula (I).

Among fibers of natural origin are human, animal and vegetable fibers such. Silk, cotton, linen, jute and Sisal and keratin fibers, like hair, furs, wool or feathers, but also regenerated or modified natural fibers, such. B. viscose, Nitro and acetyl cellulose, alkyl, hydroxyalkyl and carboxyalkyl to understand celluloses. From the class of synthetic fibers are z. As polyamide, polyester, polyacrylonitrile and Polyurethanfa to call them.

If A represents a group NR ³ , preferably nitrosubsti tuierte heterocycles of the general formula I with R ³ = hydrogen are used. However, very particular preference is given to the nitro-substituted heterocycles in which R ¹ and, if A represents a group NR ³ , R ^{3 are} hydrogen.

Some nitro-substituted heterocycles of the formula I are compounds known from the literature. Representatives are z. B. 5-nitro-1,3-dihydrobenzimidazole-2-thione, an example of a ni tro-substituted heterocycle of formula I with R ¹ is hydrogen, A is NR ³ and R ³ is hydrogen, and 6-nitro-3H- benzothiazole-2-thione, an example of a nitro-substituted heterocycle of the formula I where R ¹ is hydrogen and A is sulfur.

Further compounds of the formula I are analogous to those in the Accessible to preparation examples (1) and (2).

The nitro-substituted heterocycles of the general formula I form in the alkaline, neutral or weakly acid medium colored Ver bonds ranging from yellow to orange.

For use as colorants, the nitro-substituted He terocycles of general formula I either as such or as their water-soluble salts in an alkaline, neutral or weakly acidic preparation are incorporated. To call here are the lithium, sodium and potassium salts and the ammonium salts of Ammonia, primary, secondary and tertiary amines, e.g. B. Diiso propylethylammoniumsalze.

In the weakly acidic environment, moreover, the use of Sal zen, such as As the hydrochlorides, hydrobromides or hydrogen sulfates possible.

It is not necessary that a single connection The formula I is used, but may also be a mixture of various compounds of formula I or their salts for Ein come.

Dyeing technique, the nitro-substituted heterocycles are characterized of the formula I and their salts by good absorption on fibers and good leveling behavior.

The colors obtained are in the range from yellow to orange and are characterized by high color strength and very good light, and wash fastness.

The dyeing of textile fibers is preferably done after the off Drawing process at temperatures above 90 ° C. Others for dyeing  However, dyeing processes customary for textile fibers are also known suitable.

Particularly good staining results are, however, on keratin fibers, before preferably human hair, scored. The nitro-substituted He terocycles of the formula I are already active in physiologically compatible temperatures below 40 ° C on human hair. On Another subject of the invention are therefore means for dyeing Keratin fibers, in particular human hair, containing nitro substituted heterocycles of the general formula I or their Salts in an amount of 0.01 to 5.0 wt .-%, preferably 0.1 to 2.0 wt .-%, based on the total colorant, and a water containing carrier.

It should be noted that in the hair dyeing to the dyes and special demands are placed on the obtained dyeings. The dyes must be dermatologically and toxicologically harmless be on your hair at low temperatures. The Dyeing must be prevented against hair treatment methods such as B. Dauerwel be stable. These high requirements are the nitro substituted heterocycles of the formula I and those obtained with them Dyeing to a special degree.

For dyeing human hair are the nitrosubstituierte Heterocycles of the formula I are preferred in a cosmetic carrier, For example, creams, emulsions, gels or surfactant-containing foaming solutions z. In shampoos, foam aerosols or others Preparations suitable for applications on the hair, incorporated.

Usual components of such cosmetic preparations are, for. B. Wetting and emulsifying agents, such as anionic, nonionic and ampho lytic surfactants, e.g. As fatty alcohol sulfates, alkanesulfonates, α-Ole  finsulfonates, fatty alcohol polyglycol ether sulfates, ethylene oxide plant products of fatty alcohols, fatty acids and alkylphenols, sorbi tan fatty acid esters and fatty acid partial glycerides, fatty acid alkanols Minde and thickeners, such as. As methyl or Hydroxycellu loose, starch, fatty alcohols, paraffin oils, fatty acids, furthermore perfume oils and hair care additives, such. B. water-soluble cationic Polymers, protein derivatives, pantothenic acid and cholesterol. The Be Components of the cosmetic carriers are used to produce the he inventive colorants in usual amounts for these purposes used, for. B. become emulsifiers in concentrations of 0.5 to 30% by weight and thickening agents in concentrations of 0.1 to 25% by weight of the total colorant used.

To modify the colorations, the nitro-substituted He terocyclene of formula I but also other common substantive Dyes, such as. B. nitrobenzene derivatives, anthraquinone dyes, Triphenylmethane or azo dyes or else customary oxida tion hair dye precursors, are mixed. With the Oxida tion hair dye precursors differentiates one developer compo nenten and coupler components. Developer components form through oxidative coupling with each other or optionally in the presence suitable coupler components from the Oxidationshaarfarbstoffe. When Developers are z. B. primary aromatic amines with Another in free or paranormal free or substituted hydroxy or amino group, diaminopyridine derivatives, heterocyclic hydrazones, 4-aminopyrazolone derivatives and 2,4,5,6-Te Traaminopyrimidine and its derivatives used. As Kupplersub Metaphenylenediamine derivatives, naphthols, resorcinol and Resorcinol derivatives, pyrazolones and metaaminophenols.

Other substantive dyes and oxidation hair dyes Products can be used in an amount of 0.01 to 5 wt .-%, preferably  from 1 to 3 wt .-%, based on the total colorant his.

The application of the hair dye according to the invention can be independent on the type of cosmetic preparation z. B. as a cream, gel or Shampoo in a weakly acidic, neutral or alkaline medium It is preferred to use the hair dye in a pH Range from 6 to 10. The application temperatures can be in one Range between 15 ° C and 40 ° C. After an exposure time of about 30 minutes, the hair dye by rinsing of the Hair to be dyed removed. After that, the hair is having a mild Shampoo washed and dried. The washing up with a Shampoo is omitted if a strong surfactant-containing carrier, eg. B. a Dyeing shampoo, was used.

The following examples are intended to illustrate the subject matter of the invention but without limiting it.  

Examples Preparation Examples (1) 5-nitro-1,3-dihydrobenzimidazole-2-thione

1.0 g of 2-chloro-5-nitrobenzimidazole and 0.5 g of thiourea were refluxed in 50 ml of ethanol for one hour. The mixture was then concentrated to dryness, the residue was shaken with 50 ml aq. 2% Na ₂ CO ₃ solution and acidified after one hour with 4N hydrochloric acid solution.
Crystals of 5-nitro-1,3-dihydrobenzimidazole-2-thione were obtained. Yield: 0.9 g. (Harrison, D., JT Ralph, J. Chem. Soc. (1965) 3132)

(2) 6-nitro-3H-benzothiazole-2-thione

10.6 g of 2-chloro-6-nitrobenzothiazole and 3.8 g of thiourea were refluxed in 75 ml of ethanol. After a few minutes, the solution turned orange yellow and 6-nitro-3H-benzothiazole-2-thione crystals began to precipitate. The reaction mixture was cooled, the crystals were filtered off, washed with cold ethanol and dried. The filtrate and washings were added to 500 ml of ice water and the precipitating yellow crystals were isolated as described above.
Total yield: 10.5 g, corresponding to a quantitative conversion. (W. Scott, GW Watt, J. Org. Chem. 2 (1937) 148)

To determine the absorption maxima of the nitro-substituted He terocyclene of the formula I as a function of the pH were at the play the 5-nitro-1,3-dihydrobenzimidazole-2-thione (1) and the 6- Nitro-3H-benzothiazole-2-thiones (2) UV / Vis absorption spectra taken at pH 3.0, the absorption maximum of (1) is 355 nm, that of (2) at 365 nm; at pH 12.5, the Absorptionsma are xima at 405 nm (1) and 402 nm (2), respectively.  

applications Dyeing textile fibers

For dyeing the textile fibers was a multi-fiber conjugated tissue, type DW (according to German Authenticity Commission) from the blank 10 cm x 4 cm of Beuth Verlag GmbH, Cologne. Such a tissue is made of 6 textile strips, consisting of acetylcellulose (2.5 Ace tyl groups per monomer unit), cotton, polyamide, polyester, Polyacrylic and wool, composed.

0.5 g of the dye (1) or (2), 8 g of sodium sulfate decahydrate and 2 g of sodium carbonate were dissolved at 60 ° C in 100 ml of water. To the dyebath, the multi-fiber conjugate fabric was added. subsequently, ßend was within 45 minutes to a temperature of 98 ° C. elevated. This temperature was maintained for 1 hour, with the evaporated water was replaced continuously. After that it became dyed fabrics first with cold and then with hot Water rinsed. The tissue was then in for 20 minutes Boiled 250 ml of water containing 0.25 g sodium lauryl sulfate and then rinsed. Finally, the fabric was dried. The Dyeing results are shown in Table 1.  

Table 1

Dyeing of human hair

Hair dye creams of the following composition were prepared provides:

Fatty alcohol C _12-18 | 10 g Fatty alcohol C _12-14 + 2 EO sulfate, Na salt (28%) 25 g water 60 g Dye (1) or (2) 1 g ammonium sulfate 1 g conc. ammonia solution to pH = 9.5 water ad 100 g

The ingredients were mixed together in order. To Addition of the 5-nitro-1,3-dihydrobenzimidazole-2-thione was treated with conc. Ammonia solution adjusted the pH of the emulsion to 9.5, then was made up to 100 g with water. The coloring cream was 5 cm long strands standardized, 90% gray, but not specially pretreated human hair applied and there 30 Mi leave at 27 ° C. After completion of the dyeing process was rinsed the hair, washed out with a standard shampoo and then dried. With (1) became a Dottergelbe, with (2) achieved an absinthe yellow nuance.

Claims (5)

1. Use of nitro-substituted heterocycles of the general formula I. where R¹

• - hydrogen,
• a hydroxy group,
• an alkyl group having 1 to 4 C atoms,
• a group - (CH ₂ ) _x - OR ² , where x is 2, 3 or 4 and R ^{2 is} hydrogen or an alkyl group having 1 to 4 C atoms, or
• - represents a halogen atom

and n is an integer from 1 to 3,
A represents a sulfur atom or a group NR ³ , where R ³

• - hydrogen,
• an alkyl group having 1 to 4 carbon atoms
• a group - (CH ₂ ) _y - OR ⁴ , where y is 2, 3 or 4 and R ^{4 is} hydrogen or an alkyl group having 1 to 4 C atoms, or
• - represents a phenyl or benzyl group or salts thereof for dyeing fibers of natural origin and synthetic fibers.

2. Use of nitro-substituted heterocycles of the general formula I according to claim 1, characterized in that, if A represents a group NR ³ , R ^{3 is} hydrogen. 3. Use of nitro-substituted heterocycles of the general formula I according to claim 1 and 2, characterized in that R ¹ and, if A represents a group NR ³ , R ^{3 are} hydrogen. 4. Agent for dyeing keratin fibers, in particular human Hair containing nitro-substituted heterocycles of the general my formula I or their salts in an amount of 0.01 to 5.0 wt .-%, preferably 0.1 to 2.0 wt .-%, based on the entire colorant, and a hydrous carrier.