AU5655898A - Treatment of keratin-based substrates - Google Patents

Description

WO 98/24964 PCT/EP97/06615 The treatment of keratin-containing substrates The present invention relates to a process for treating keratin-containing substrates to protect them against keratin pests using a liquid formulation which comprises a 5 diphenylurea active ingredient, surfactants, solvents and standardizing agents. The term standardizing agents includes softeners, for example phosphates, iminodisuccinates (IDS), polyaspartic acid (PAA), ethylenediamine-tetraacetic acid (EDTA) and others. It is known that keratin-containing substrates are damaged, and eventually destroyed, by 10 keratin-digesting pests such as the larvae of moths and of carpet beetles and fur beetles. Keratin-containing substrates of this kind are animal skins, furs, hair, wool, feathers, nails, hoofs, horns and plates and also silk. These substrates are processed, in many cases in combination with other materials, not at risk from feeding damage, to give various utility articles. This concerns in particular the use of wool, silk and blends 15 thereof with other natural or synthetic fibers for the production of clothing and of textiles for walls, floors and upholstered furniture. There has therefore been no lack of attempts in the past to protect these substrates by treating them with feeding inhibitors. Feeding inhibitors in accordance with DE 44 25 359 Al comprise, for example, as active ingredient a diphenylurea of the formula 20 R

R

5

R

2 / 0 NH-CO-NH CI M,

R

3 R4 in which R1 is hydrogen or 4-chloro-phenoxy-6-sulfonate, R2 is hydrogen or chlorine,

R

3 is chlorine or trifluoromethyl, R 4 is hydrogen or chlorine and R 5 is hydrogen or 25 trifluoromethyl. This active ingredient can be employed as a liquid formulation, for example with 1 part by weight of the diphenylurea active ingredient (I) and 2 parts by weight of propylene glycol. If, for example, a continuous process is operated it is found, however, that the 30 amounts of the active ingredient which pass from such liquid formulations onto the substrate are inadequate. Consequently, after treatment of the abovementioned substrates there remains a liquor, depleted in active ingredient, whose residual active -2 ingredient can be re-used only to a minor extent by concentration with further liquid formulation of the active ingredient, owing to the simultaneous contamination of the liquor by substrate components and other impurities, and must for the major part be disposed of; in this case, disposal is complicated by the high proportion of diphenylurea 5 active ingredient which remains. It was therefore desirable to develop other processes using said active ingredient which ensure increased passing of the active ingredient onto the substrate. 10 The invention provides a process for treating keratin-containing substrates to protect them against keratin pests using diphenylureas of the formula R R 5

R

2 / \ NH-CO-NH / C1 (I),

R

3 R4 15 in which

R

1 denotes hydrogen or 4-chlorophenoxy-6-sulfonate, R 2 denotes hydrogen or chlorine, 20 R 3 denotes chlorine or trifluoromethyl, R4 denotes hydrogen or chlorine and 25 R' denotes hydrogen or trifluoromethyl, which comprises treating the substrates at 30-1 10*C and at a pH of 2-7 with an aqueous liquor which comprises 1-25 ml/l of a liquid formulation consisting of 30 a) from 4 to 50% by weight of diphenylurea of the formula (I), b) from 2 to 50% by weight of one or more surfactants from the group consisting of the anionic, cationic and nonionic surfactants, -3 c) from 30 to 94% by weight of one or more solvents from the group consisting of the straight-chain or branched CI-C 1 2 -alkanols and of the C 2

-C

4 -polyols and their mono- or diethers with C 1

-C

4 -alkanols or with C 2

-C

4 -diols, of the C 3

-C

6 5 ketones, of the C 1

-C

6 -carboxylic acids and their esters with a C 1

-C

4 -alkanol or

C

2

-C

4 -polyol, of the N-(C 1

-C

4 -alkyl)-lactams having 5 to 8 ring members, dimethyl sulfoxide or a mixture of two or more thereof, where from 1 to 30% of their weight can be replaced by water, and 10 d) from 0 to 10% by weight of standardizing agents from the group consisting of the phosphates, polyphosphates, iminodisuccinate acid (IDS), hydroxy iminodisuccinic acid, polyaspartic acid (PAA), ethylenediamine-tetraacetic acid (EDTA), urea and urea derivatives some or all of whose H atoms can be substituted by C 1

-C

4 -alkyl or phenyl, sodium sulfate, ammonium sulfate and the 15 formaldehyde condensates of aromatic sulfonic acids, the percentages being based on the overall weight of the liquid formulations. Preferred liquid formulations for the process according to the invention comprise 20 a) from 10 to 40% by weight of the diphenylurea active ingredient (I), b) from 10 to 45% by weight of one or more abovementioned surfactants, 25 c) from 35 to 80% by weight of one or more abovementioned solvents and d) from 0 to 8% by weight of the abovementioned standardizing agents, all based on the overall weight of the formulations. 30 Particularly preferred liquid formulations comprise a) from 15 to 30% by weight of the diphenylurea active ingredient (I), b) from 15 to 40% by weight of one or more abovementioned surfactants, 35 c) from 40 to 70% by weight of one or more abovementioned solvents and -4 d) from 0 to 7% by weight of the abovementioned standardizing agents, all based on the overall weight of the formulations. 5 Surfactants which can be employed for the liquid formulations which are to be employed in accordance with the invention can be one or more from the group consisting of the anionic, cationic and nonionic surfactants. Anionic surfactants which can be employed are aliphatic, araliphatic, aromatic or alkylaromatic hydrocarbon 10 compounds having 8 to 22 C atoms which contain one or more carboxyl, sulfonic acid, sulfuric acid monoester or phosphonic acid group whose acid proton may be replaced by a cation from the group consisting of Lie, Na*, Ke, NH4*, H 3

N-CH

2

CH

2 OHe,

H

2

N(CH

2

CH

2

OH)

2 * and HN(CH 2

CH

2

OH)

3 *; this form in which there has been replacement by a cation is preferably employed. Examples thereof are: Cs-C22 15 carboxylic acids and their salts with cations of the abovementioned type, C 8

-C

2 2 -alkyl sulfonic acids and their salts with cations of the abovementioned type, C 4

-C

16 -alkyl benzene- and -naphthalene-sulfonic acids and their salts with cations of the abovementioned type, (poly)sulfonic acids of phenol-, diphenyl sulfone-, dihydroxydiphenyl sulfone- or naphthalene-formaldehyde condensates and also 20 (poly)sulfonic acids of diphenyl ether, ditolyl ether and terphenyl and their salts with cations of the abovementioned type, C 8

-C

22 -alkyl-sulfuric acid monoesters and C 8

-C

22 alkyl-phosphonic acids and their salts with cations of the abovementioend type. Individual substances which may be mentioned are: sulfonated phenyl-formaldehyde condensate and its Na salt, naphthalenesulfonic acid-formaldehyde condensate and its 25 Na salt, naphthalenesulfonic acid-dihydroxydiphenyl sulfone condensate and its Na salt, ditolyl ether sulfonic acid-formaldehyde condensate Na salt, NH 4 terphenylsulfonate, Na ditolyl ether sulfonate, NH 4 oleate, diisobutyl-naphthalenesulfonic acid Na salt, Na dodecylbenzenesulfonate, sulfated lauryl alcohol, optionally alkoxylated with 3 mol of ethylene oxide (EO), sulfated nonylphenol, optionally with 4 EO, C 10

-C

1 2 -, C 12

-C

16 - or 30 C 12

-C

21 -alkanesulfonate Na salt, Na di(2-ethylhexyl) phosphate, C 1 2

/C

1 3 -alkanol sulfate ethanolamine salt, sulfonated beef tallow as the Na salt, dibutyl phosphate diethanolamine salt. Instead of EO, alkoxylation can also be carried out with propylene oxide (PO) or with EO and PO. 35 Cationic surfactants which can be employed are tertiary amines in protonated form or quaternized ammonium compounds which contain on the N atom at least one aliphatic, -5 araliphatic, aromatic or alkylaromatic substituent which contains 8 to 22 C atoms; examples of anions for this purpose are Cl-, Br, 1/2 sulfate or 1/3 phosphate. Examples hereof are: C 8

-C

22 -alkyl-dimethyl-benzyl-ammonium chloride, amide of ethylenepolyamines and oleic acid, as the acetate, di-stearamide of diethylenetriamine 5 as the acetate, stearic acid-triethylenetetraamine condensate as the acetate, and tallow fatty alkyl-bishydroxyethyl-amine hydrochloride. Examples of betaine surfactants are: R-*NH 2

-CH

2 -COO~, R-CH(*NR1 3 )-COO~,

R-*NR'

2

(CH

2

)

3 -SO3- and others known to the skilled worker, in which R represents 10 alkyl, aralkyl, aryl or alkylaryl having 8-20 C atoms and R 1 represents identical or different C 1

-C

4 -alkyl. Examples of nonionic surfactants for the liquid feeding inhibitors according to the invention are polyethers of the formula 15 R-(-EO)m-(-PO)n-H (II), in which 20 R denotes for C 8

-C

22 -0, C 8

-C

22 -CO-0, C 8

-C

22 -CO-NH or C 4 -Ci 6 -alkyl-phenylene 0, EO and PO represents ethylene oxide and propylene oxide units, respectively, and 25 the indices m and n independently of one another denote numerical values from 0 to 50, but where the sum m+n is at least 2. The abovementioned radicals R are typically those as are known from the chemistry of fats, or are alkyl-aromatic radicals. Nonionic surfactants of the formula (II), 30 accordingly, are polyglycol ethers formed from ethylene oxide, propylene oxide or a mixture of the two with fatty alcohols, fatty acids, fatty acid amides or alkylphenols. Since, even if ethoxylation or propoxylation of mixtures is conducted in a controlled manner, the individual molecules in the ethoxidation or propoxidation of such substrates from fat chemistry represent compounds with different degrees of 35 ethoxylation or propoxylation, respectively, the indices m and n will in practice represent not only whole numbers but also intermediate values between whole numbers.

-6 In this context, mention may be made preferably of radicals R from fatty alcohols and alkylphenols. Typical individual examples are oleyl alcohol with from 30 to 50 EO, isododecanol with 8.5 EO, isodecylalcohol with 6 EO and 8 PO, nonyl/undecyl alcohol with 5 EO and 5 PO, castor oil with 30 EO, palm kernel fatty acid with 6.5 EO, stearyl 5 alcohol with from 6 to 30 EO, oleic acid with 6.5 EO, ethylhexyl alcohol with 6 EO, lauryl alcohol with from 2.5 to 30 EO and nonylphenol with from 4 to 30 EO. Preferably, one or more surfactants from the group of the abovementioned nonionic surfactants, or their mixtures with cationic or anionic surfactants, are employed. 10 Antifoams known to the skilled worker may be added to the surfactants. Solvents for the liquid formulations to be employed in accordance with the invention are one or more from the abovementioned group. Examples of straight-chain or 15 branched CI-C 1 2 -alkanols are methanol, ethanol, propanol, isopropanol, butanol, isobutanol, the isomeric pentanols, hexanols, octanols, decanols or dodecanols. Examples of C 2

-C

4 -polyols are ethylene glycol, 1,2- or 1,3-propanol, 1,2-, 1,3-, 1,4 butanediols or glycerol. Mono- or diethers of these polyols of C 1

-C

4 -alkanols or with

C

2

-C

4 -diols are, for example, ethylene glycol monomethyl ether and dimethyl ether, 20 ethylene glycol monoethyl ether and diethyl ether, such as 1-ethoxy-2-propanol and 1-methoxy-2-propanol, the homologous mono- and diethers of ethylene glycol with one of the abovementioned C 3 - or C 4 -alkanols, the corresponding mono- and diethers of the abovementioned higher diols or glycerol with methanol, ethanol or with one of the abovementioned higher alkanols, ethers of the abovementioned polyols with C 2

-C

4 25 diols, such as diethylene glycol or tripropylene glycol, or ethers of a polyol and both a diol and a C 1

-C

4 -alkanol, examples being diethylene glycyol monomethyl ether, monoethyl ether or monobutyl ether. Examples of ketones are acetone, butanone, 2- or 3-pentanone and 2- or 3-hexanone; examples of acids and esters are acetic acid, propionic acid, ethyl acetate, 2-ethoxyethyl acetate. Examples of lactams are N-methyl 30 pyrrolidone or -caprolactam. Among the solvents mentioned, it is preferred to employ those which have a high flash point. Preferred solvents for the liquid feeding inhibitor formulations according to the invention are, therefore, one or more from the group consisting of the straight-chain or branched C 3

-C

8 -alkanols, of the C 2

-C

3 -diols and their monoethers with Ci-C 3 -alkanols or C 2

-C

3 -diols. Where these solvents are miscible with 35 water, from 1 to 30%, preferably from 5 to 25% of their weight can be replaced by water.

-7 Where used concomitantly, standardizing agents are one or more of the abovementioned type which are known to the skilled worker. Examples of aromatic sulfonic acids are benzenesulfonic acids, toluenesulfonic acids. phenolsulfonic acid, 5 naphthalenesulfonic acids, sulfonated ditolyl ethers, 4,4'-dihydroxydiphenyl sulfone, sulfonated diphenylmethane, sulfonated biphenyl and sulfonated terphenyl. Examples of urea derivatives are dimethylolurea, melamine and guanidine. In urea and its derivatives some or all of the H atoms can be substituted by CI-C 4 -alkyl, such as methyl, ethyl, propyl, butyl or phenyl. Formaldehyde condensates in this context are 10 those formed from sulfonated aromatic compounds, formaldehyde and, optionally, one or more compounds from the group consisting of the nonsulfonated aromatic compounds, urea and urea derivatives. Sulfonated aromatics are, for example, those mentioned above. Examples of nonsulfonated aromatic compounds are phenol, cresol and dihydroxydiphenylmethane. 15 As diphenylurea active ingredient (I) it is preferred to employ one of the formula CI

MO

3 S /0 0 CI (III) NH-CO-NH Cl C1 20 in which M is an alkali metal cation, for example Na*. The invention provides the treatment of keratin-containing substrates of the abovementioned type, preferably the treatment of wool, silk and blends thereof with other natural or synthetic fibers. Examples of such blends are: wool/acrylonitrile, 25 wool/polyester, wool/nylon, wool/polypropylene, wool/cellulose and wool/silk. The abovementioned substrates are treated with the liquid formulations in aqueous liquor in processes which are known in principle to the skilled worker, examples being tape-scour processes, raw wool washing, Chemset processes, exhaust processes and 30 spray processes. In these processes the treatment of the abovementioned substrates with -8 the liquid formulations can be combined with other procedures, for example with dyeing. The addition of the liquid formulations to the liquor takes place on the part of the skilled worker in dependence on the desired amount of active ingredient on the substrate. To the skilled worker, liquid formulations within the scope of the 5 concentrations disclosed above, with from 4 to 50% by weight of the diphenylurea active ingredient (I), can be employed for this metering. In the case of formulations in the lower region of the overall concentration range of (I) the metering can be very fine; the disadvantage associated with this, however, is the large volume of liquid formulation required. Formulations in the upper region of the stated concentration of (I) 10 are intended primarily for transportation and storage purposes, so as to have to transport as little solvent as possible. Highly concentrated formulations of this kind are adjusted by the user, by dilution, to a median service strength. A typical median service strength has a content of from about 20% by weight to 35% by weight of (I) in the ready-to-use formulations. From about 1 to 25 ml of a formulation adjusted in this way are employed 15 per 1 of liquor, preferably from 1.5 to 10 ml/l and, with particular preference, from 1.5 to 4 ml/l. In this case the formulations give contents of diphenylurea active ingredient (I) of from about 2900 to 3000 mg/kg of substrate to be treated for a deployed amount of 1.5 ml/l, up to over 7000 mg/kg of substrate for a deployed amount of 4 mIl in the liquor. These attainable contents of active ingredient on the substrate amount to about 20 from 1.4 to 1.6 times that of treatment compositions known to date containing the diphenylurea active ingredient (I), in the lower range, up to from 2.4 to 2.5 times in the higher range of the content on the substrate. The treatment according to the invention is conducted at 30-1 10*C, preferably 40 25 100'C and in the pH range of 2-7. The process according to the invention gives the substrates thus treated protection against keratin tests, for example of the following species: Tineola bisselliella, Authrenus flavipes, Tinea pellionella, Tinea translucens, Attagenus pellio. 30 -9 Examples Example 1 (Testing by the tape-scour process) 5 1 g/l of surfactant solution (mixture of CIo-20-alkanesulfonate with nonylphenol* 7EO, content of active ingredient 40%) was stirred at 50'C in softened water. A 5 g strand of wool was dipped for 30 seconds in 2 liters of such a solution and then squeezed by means of a laboratory padder to 50% liquor pickup. Subsequently, softened water alone was employed in the same procedure. Then a liquor with the intended amount of liquid 10 formulation (e.g. 1.5 ml/l or 2.5 mIl) and 2 mIll of acetic acid (purity 60%) was prepared and the strand of wool was immersed for 30 seconds at the intended temperature (e.g. 40*C, 50*C, 60*C or 70C). Finally, the strand was squeezed off to a residual moisture content of 50%, dried in air and analyzed for uptake of active ingredient. 15 Example 2 The process described in Example 1 was used to treat a woollen fabric in a liquor having the deployed amounts specified in Tab. 1 at 50*C and at a pH of 4.5. The active 20 ingredient was a 33% strength by weight solution of the diphenylurea active ingredient (III) with M = Na8 in propylene glycol. The content of active ingredient on the substrate as a function of the amount of active ingredient deployed, and the quotient calculated from this, are indicated in Tab. 1. 25 Example 3 The process described in Example 1 was used to treat a woollen fabric in a liquor having the deployed amounts specified in Tab. 1 at 50'C and at a pH of 4.5. The active ingredient was a 40% strength by weight solution of the diphenylurea active ingredient 30 (III) with M = Na* in aqueous ethoxypropanol which additionally contained about 10% of urea and sodium polyphosphate. The content of active ingredient on the substrate as a function of the amount of active ingredient deployed, and the quotient calculated from this, are indicated in Tab. 1. The chosen amounts deployed in this case were lower than in Example 2 in order to take account of the higher content of active ingredient (40% as 35 against33%).

-10 Example 4 In a further experiment, in the process described in Example 1, a liquid feed inhibitor formulation having the following composition was employed: 20% by weight of 5 diphenylurea active ingredient (II), 5% by weight of urea and Na polyphosphate, 45% by weight of diethylene glycol and 30% by weight of a nonionic surfactant (ethoxylated and propoxylated C 9

.

11 -alcohols). The amounts deployed were chosen as in Example 2 despite the fact that the concentrations of active ingredient were markedly lower. From this liquor, which accordingly was less concentrated, a greater amount of active 10 ingredient passed on to the substrate (Tab. 1). Example 5 In accordance with the process described in Example 1, a liquid feed inhibitor 15 formulation having the following composition was employed in accordance with the invention: 20% by weight of diphenylurea active ingredient (III), 5% by weight of urea and Na polyphosphate, 2.5% by weight of water, 22.5% of ethoxypropanol, 20% of diethylene glycol and 30% by weight of a nonionic surfactant (ethoxylated and propoxylated C 9 1 -alcohols). With a significantly reduced supply of active ingredient in 20 comparison with Example 2, a significantly improved passage of active ingredient onto the substrate is observed (Tab. 1). Tab. 1 Results of Examples 2 to 5. The quotient of absolute uptake of active ingredient and supply of active ingredient in the liquor has been multiplied by a factor of 1000. 25 - 11 Example Amount of active ingredient used [mg/l] [mg] in 2-1 Content on Quotient of liquor product active [mg/kg] ingredient on product/supply Example 2 1.5 1139 1184 8.27 2.5 1898 2250 5.93 3.5 2657 2674 5.03 4.0 3036 2873 4.73 Example 3 1.3 1206 2139 8.87 2.1 1949 2305 5.91 2.9 2691 3060 5.69 3.4 3155 2996 4.75 Example 4 1.5 690 2963 21.47 2.5 1150 5465 23.76 3.5 1610 6534 20.29 4.0 1840 7174 19.49 Example 5 0.5 222 1839 41.44 1.0 444 3263 36.76 1.5 666 4563 34.26 11 __ _ 1 2.0 888 5635 31.73 Example 6 5 The procedure described in Example 1 was carried out under standardized conditions using not only in each case 3.4 ml/l of the formulation used in Example 3 (active ingredient content 40%) but also various surfactants in a proportion of 33%, based on the active ingredient formulation. The passage of the diphenylurea active ingredient (III) onto the substrate was significantly improved in each case (Tab. 2). 10 Surfactant A: Mixture of ethoxylated CIO-alcohol and propoxylated C 8 -alcohol. Surfactant B: Ethoxylated C 20 -alcohol Surfactant C: Ethoxylated and propoxylated CIO-alcohol - 12 Table 2 Results of Example 6. The quotient of absolute uptake of active ingredient and supply of active ingredient in the liquor has been multiplied by a factor of 1000. Surfactant type Amount of active ingredient used [mg/l] [mg] in 2-1 Content on Quotient of liquor product active [mg/kg] ingredient on product/supply Without 3.4 3155 3250 5.15 surfactant A 3.4 3155 4020 6.37 B 3.4 3155 5400 8.56 C 3.4 3155 11150 17.67 5 Example 7 In analogy to the process described in Example 1, liquors were treated with 3.4 ml/1 of the treatment composition known from Example 3, but where first of all water and then 10 ethoxypropanol were replaced in stages by a surfactant mixture having the following composition: Ethoxylated and propoxylated Cro-alcohol, ethoxylated C 16 -alcohol, C 8 sulfate ammonium salt and tributyl phosphate. Proportions of the surfactant mixture from the formulation, and also the concentrations of active ingredient on the substrate, are given in Table 3. 15 - 13 Table 3 Results of Example 7. The quotient of absolute uptake of active ingredient and supply of active ingredient in the liquor has been multiplied by a factor of 1000. Proportion of Amount of active ingredient used surf actant [mg/] [mg] in 2-1 Content on Quotient of liquor product active [mg/kg] ingredient on product/supply 0% 3.4 3155 3410 5.40 2% 3.4 3155 4580 7.26 10% 3.4 3155 5590 8.86 15% 3.4 3155 6425 10.18 20% 3.4 3155 7155 11.34 5 Example 8 Following the procedure of Example 1 the liquid formulation from Example 5 with deployed amounts of 1.5 ml/I and 2.5 m/l was applied at different temperatures to a wool substrate. A higher bath temperature had an additional positive effect on the 10 passage of the active ingredient onto the substrate (results: Table 4).

-14 Table 4 Results of Example 8. The quotient of absolute uptake of active ingredient and supply of active ingredient in the liquor has been multiplied by a factor of 1000. Temperature Amount of active ingredient used [mg/] [mg] in 2-1 Content on Quotient of liquor product active [mg/kg] ingredient on product/supply 40 0 C 1.5 666 3440 25.83 50 0 C 1.5 666 4000 30.03 60 0 C 1.5 666 4490 33.71 70 0 C 1.5 666 4625 34.72 40 0 C 2.5 1110 4425 19.93 50 0 C 2.5 1110 5025 22.64 60 0 C 2.5 1110 6540 29.46 70*C 2.5 1110 7100 31.98

Claims (9)

1. A process for treating keratin-containing substrates to protect them against keratin pests using diphenylureas of the formula R R 5 R 2 / NH-CO-NH C R 3 R in which R' denotes hydrogen or 4-chlorophenoxy-6-sulfonate, R2 denotes hydrogen or chlorine, R 3 denotes chlorine or trifluoromethyl, R 4 denotes hydrogen or chlorine and R 5 denotes hydrogen or trifluoromethyl, which comprises treating the substrates at 30-1 10 0 C and at a pH of 2-7 with an aqueous liquor which comprises 1-25 mIl of a liquid formulation consisting of a) from 4 to 50% by weight of diphenylurea of the formula (I), b) from 2 to 50% by weight of one or more surfactants from the group consisting of the anionic, cationic and nonionic surfactants, c) from 30 to 94% by weight of one or more solvents from the group consisting of the straight-chain or branched Cl-C 1 2 -alkanols and of the C 2 -C 4 -polyols and their mono- or diethers with C 1 -C 4 -alkanols or with C 2 -C 4 -diols, of the C3-C 6 -ketones, of the Cl-C 6 -carboxylic acids and their esters with a Ci-C 4 -alkanol or C 2 -C 4 -polyol, of the N-(Ci-C 4 -alkyl)- -16 lactams having 5 to 8 ring members, dimethyl sulfoxide or a mixture of two or more thereof, where from 1 to 30% of their weight can be replaced by water, and d) from 0 to 10% by weight of standardizing agents from the group consisting of the phosphates, polyphosphates, iminodisuccinate acid, hydroxy-iminodisuccinic acid, polyaspartic acid, ethylenediamine tetraacetic acid, urea and urea derivatives some or all of whose H atoms can be substituted by CI-C 4 -alkyl or phenyl, sodium sulfate, ammonium sulfate and the formaldehyde condensates of aromatic sulfonic acids, the percentages being based on the overall weight of the liquid formulation.

2. The process as claimed in claim 1, wherein the liquid formulation consists of a) from 10 to 40% by weight of the diphenylurea active ingredient (I), b) from 10 to 45% by weight of one or more surfactants, c) from 35 to 80% by weight of one or more solvents and d) from 0 to 8% by weight of the standardizing agents, the percentages being based on the overall weight of the formulation.

3. The process as claimed in claim 1, wherein the liquid formulation consists of a) from 15 to 30% by weight of the diphenylurea active ingredient (I), b) from 15 to 40% by weight of one or more surfactants, c) from 40 to 70% by weight of one or more solvents and d) from 0 to 7% by weight of the standardizing agents, the percentages being based on the overall weight of the formulation. -17

4. The process as claimed in claim 1, wherein the liquid formulation comprises, as surfactants, one or more from the group consisting of the nonionic surfactants.

5. The process as claimed in claim 1, wherein the solvent present in the liquid formulation comprises one or more from the group consisting of the straight chain or branched C 3 -C 8 -alkanols, of the C 2 -C 3 -diols and their monoethers with CI-C 3 -alkanols or C 2 -C 3 -diols, it being possible for 1 to 30% of their overall weight to be replaced by water.

6. The process as claimed in claim 1, wherein the liquid formulation comprises a diphenylurea of the formula CI MO 3 S_ / 0 0 CI NH-CO-NH C CI in which M is an alkali metal cation, preferably Na*.

7. The process as claimed in claim 1, wherein keratin-containing substrates treated are wool, silk and blends thereof with other natural or synthetic fibers.

8. The process as claimed in claim 1, wherein the aqueous liquor comprises 1.5 to 10 mI/1 of the liquid formulation.

9. The process as claimed in claim 1, which is operated at 40-100'C.