WO2001044210A1

WO2001044210A1 - Allyl- and diallylaminotriazinylaminostilbene derivatives and their use as optical brightening

Info

Publication number: WO2001044210A1
Application number: PCT/EP2000/012200
Authority: WO
Inventors: Bernd Wockenfuss; Hans Kramer
Original assignee: Ciba Spezialitaetenchemie Holding AG; Ciba SC Holding AG
Current assignee: BASF Schweiz AG
Priority date: 1999-12-14
Filing date: 2000-12-05
Publication date: 2001-06-21
Anticipated expiration: 2002-06-14
Also published as: AU3006201A; AR026924A1

Abstract

The present invention provides new compounds having formula: wherein each R1 represents, independently, an allyl- or diallylamino residue; each R2 represents, independently, phenylamino which is unsubstituted or substituted by one or more C1-C4-alkyl, halogen, cyano, SO3M, -SO2NH2, SO2NHC1-C4-alkyl, -CO2M, -CO2C1-C4-alkyl, -CONH2, -CONHC1-C4-alkyl, or -NHCOC1-C4-alkyl groups, with the proviso that the phenylamino group is not substituted by two SO3Na groups; or an allyl- or diallylamino residue and M is an alkali or alkaline-earth metal atom, ammonium or a cation formed from an amine and their use as optical brightening agents for synthetic or natural organic materials, especially cotton and polyamide.

Description

ALLYL- AND DIALLYLAMINOTRIAZINYLAMINOSTILBENE DERIVATIVES AND THEIR USE AS OPTICAL BRIGHTENING

The present invention relates to new allyl- and diallylaminotriazinylaminostilbene derivatives which are useful as optical brightening agents for synthetic or natural organic materials.

In Dyes and Pigments, 43, 197-201 (1999) the synthesis and properties of the free sulphonic acids of a number of unsaturated triazinylstilbene fluorescent brightening agents has been described. However, the use of these compounds, in the form of the free sulphonic acids, is directed primarily towards their copoiymerisation with styrene and acrylonitrile to yield colourless fluorescent polymers.

It has now, surprisingly, been found that novel salts of allyl- and diallyiaminotriazinylamino- stilbenes are useful as optical brightening agents for paper, textile and detergent applications, possessing superior properties with regard to, for example, solubility, light- fastness and degree of whiteness.

Accordingly, the present invention provides new compounds having the formula:

wherein each

Ri represents, independently, an allyl- or diallylamino residue; each

R represents, independently, phenylamino which is unsubstituted or substituted by one or more C,-C₄-aikyl, halogen, cyano, S0₃M, -S0₂NH₂, S0₂NHCι-C₄-alkyl, -C0₂M, -C0₂C₁-C4-al yl, -CONH₂, -CONHd-C-4-alkyl, or -NHCOCrC₄-alkyl groups, with the proviso that the phenylamino group is not substituted by two S0₃Na groups; or an allyl- or diallylamino residue and M is an alkali or alkaline-earth metal atom, ammonium or a cation formed from an amine.

Within the scope of the compounds of formula (1 ) both of the R , groups and the R₂ groups are preferably identical.

Preferred compounds of formula (1) are those in which R₂ represents phenylamino, optionally substituted by a Cι-C₄-alkyl, halogen, cyano, S0₃M, -SO₂NH₂, SO₂NHC₁-C₄-alkyl, -C0₂M, -C0₂Ci-C₄-alkyl, -CONH₂, -CONHCι-C₄-alkyl, or -NHCOd-C₄-alkyl group, especially such in which R₂ represents phenylamino which may be substituted by S0₃M, M being as previously defined.

Further preferred compounds of formula (1) are those in which R^ and R₂ both, independently, represent an allyl- or diallylamino residue.

The cation M, within the scope of formula (1), is, preferably, Na, K, Ca, Mg, ammonium, mono-, di-, tri- or tetra-Crdalkylammonium, mono-, di- or tri-C₂-C -hydroxyalkylammonium or ammonium that is di- or tri-substituted with a mixture of C C₄-alkyl and C₂-C₄-hydroxyalkyl groups.

Especially preferred compounds of formula (1) are those in which R^ is allylamino, R₂ is phenylamino which may be unsubstituted or substituted by S0₃Na and M is Na , as well as those, in which R< is diallylamino, R₂ is phenylamino which may be unsubstituted or substituted by S0₃Na, whereby M is Na and, additionally, those in which Ri and R₂ are both allylamino or diallylamino and M is Na.

Within the scope of the above definitions, Cι-C₄alkyl may be methyl, ethyl, n- or isopropyl or n-, sec- or t-butyl and C₂-C₄-hydroxyalkyl may be hydroxyethyl, hydroxypropyl or hydroxybutyl, whilst halogen may be fluorine, chlorine, bromine or iodine, preferrably chlorine. The compounds of formula (1) may be produced by reacting, under known reaction conditions, cyanuric chloride, successively, in any desired sequence, with each of 4,4'-diaminostilbene-2,2'- disulfonic acid, an amino compound capable of introducing a group group R₂ in which R₂ has its previous significance, and a compound capable of introducing a group Rι, in which Ri has its previous significance i.e. allyl- or diallylamine

Preferably, 2 moles of cyanuric chloride are initially reacted with 1 mole of 4,4'-diaminostilbene-2,2'- disulfonic acid, then with an amino compound capable of introducing a group R₂ in which R₂ has its previous significance, and, finally, with allyl- or diallylamine.

The starting materials are known compounds which are readily available.

A further aspect of the invention is a composition for whitening synthetic or natural organic materials, which contains water, a fluorescent whitening agent of formula (1) and, optionally, auxiliaries.

More specifically, such brightener compositions contain water and, in each case based on the weight of the formulation, from 3 to 25% by weight, preferably from 5 to 15% by weight of the above defined fluorescent whitening agent mixture and also 0 to 60%, preferably 5 to 50% by weight, of auxiliaries.

Suitable auxiliaries include, for example, anionic or non-ionic dispersants from the class of ethylene oxide adducts with fatty alcohols, higher fatty acids or alkyl phenols or ethylenediamine ethylene oxide-propylene oxide adducts, copolymers of N-vinylpyrrolidone with 3-vinylpropionic acid, water retention aids, such as ethylene glycol, glycerol orsorbitol, or biocides.

Most of the compounds of formula (1) are excellent fluorescent whitening agents for substrates such as textiles and for paper and for the addition to detergent compositions.

Accordingly, the present invention further provides a method for the fluorescent whitening of a substrate comprising contacting the substrate with a compound having the formula (1). When used for the fluorescent whitening of paper, the compound of formula (1) according to the present invention may be applied to the paper substrate in the form of a paper coating composition, or directly in the size press.

In one preferred aspect, the present invention provides a method for the fluorescent whitening of a paper surface, comprising contacting the paper surface with a coating composition comprising a white pigment; a binder dispersion; optionally a water-soluble co-binder; and sufficient of a fluorescent whitening agent having the formula (1) according to the present invention, to ensure that the treated paper contains 0.01 to 1 % by weight, based on the white pigment, of a fluorescent whitening agent having the formula (1 ).

As the white pigment component of the paper coating composition used according to the method of the present invention, there are preferred inorganic pigments, e.g., aluminium or magnesium silicates, such as China clay and kaolin and, further, barium sulfate, satin white, titanium dioxide , calcium carbonate (chalk) or talcum; as well as white organic pigments.

The paper coating compositions used according to the method of the present invention may contain, as binder, inter alia, plastics dispersions based on copolymers of butadiene/styrene, acrylonitrile/butadiene/styrene, acrylic acid esters, acrylic acid esters/styrene/acrylonitrile, ethylene/vinyl chloride and ethylene/vinyl acetate; or homopolymers, such as polyvinyl chloride, polyvinylidene chloride, polyethylene and polyvinyl acetate or polyurethanes. A preferred binder consists of styrene/butyl acrylate or styrene/butadiene/ acrylic acid copolymers or styrene/butadiene rubbers. Other polymer latices are described, for example, in U.S.Patent Specifications 3,265,654, 3,657,174, 3,547,899 and 3,240,740.

The optional water-soluble protective colloid may be, e.g., soya protein, casein, carboxymethylcellulose, natural or modified starch, chitosan or a derivative thereof or, especially, polyvinyl alcohol. The preferred polyvinyl alcohol protective colloid component may have a wide range of saponification levels and molecular weights; e.g. a saponification level ranging from 40 to 100; and an average molecular weight ranging from 10,000 to 100,000. Recipes for coating compositions for paper are described, for example, in J.P. Casey "Pulp and Paper"; Chemistry and Chemical Technology, 2nd edition, Volume III, pagesl 684-1649 and in "Pulp and Paper Manufacture", 2nd and 5th edition, Volume II, page497 (McGraw-Hill).

The paper coating compositions used according to the method of the present invention preferably contain 10 to 70% by weight of a white pigment. The binder is preferably used in an amount which is sufficient to make the dry content of polymeric compound up to 1 to 30% by weight, preferably 5 to 25% by weight, of the white pigment. The amount of fluorescent brightener preparation used according to the invention is calculated so that the fluorescent brightener is preferably present in amounts of 0.01 to 1 % by weight, more preferably 0.05 to 1% by weight, and especially 0.05 to 0.6% by weight, based on the white pigment.

The paper coating composition used in the method according to the invention can be prepared by mixing the components in any desired sequence at temperature from 10 to 100°C, preferably 20 to 80°C. The components here also include the customary auxiliaries which can be added to regulate the rheological properties, such as viscosity or water retention capacity, of the coating compositions. Such auxiliaries are, for example, natural binders, such as starch, casein, protein or gelatin, cellulose ethers, such as carboxyalkylcellulose or hydroxyalkylcellulose, alginic acid, alginates, polyethylene oxide or polyethylene oxide alkyl ethers, copolymers of ethylene oxide and propylene oxide, polyvinyl alcohol, water-soluble condensation products of formaldehyde with urea or melamine, polyphosphates or polyacrylic acid salts.

The coating composition used according to the method of the present invention is preferably used to produce coated printed or writing paper, or special papers such as cardboard or photographic papers.

The coating composition used according to the method of the invention can be applied to the substrate by any conventional process, for example with an air blade, a coating blade, a roller, a doctor blade or a rod, or in the size press, after which the coatings are dried at paper surface temperatures in the range from 70 to 200°C, preferably 90 to 130°C, to a residual moisture content of 3-8%, for example with infra-red driers and/or hot-air driers. Comparably high degrees of whiteness are thus achieved even at low drying temperatures.

By the use of the method according to the invention, the coatings obtained are distinguished by optimum distribution of the dispersion fluorescent brightener over the entire surface and by an increase in the level of whiteness thereby achieved, by a high fastness to light and to elevated temperature (e.g. stability for 24 hours at 60-100°C.) and excellent bleed-fastness to water.

In a second preferred aspect, the present invention provides a method for the fluorescent whitening of a paper surface comprising contacting the paper in the size press with an aqueous solution containing a size, optionally an inorganic or organic pigment and 0.1 to 20g/l of a fluorescent whitening agent having the formula (1). Preferably, the size is starch, a starch derivative or a synthetic sizing agent, especially a water-soluble copolymer.

In a third preferred aspect, the brighteners defined above are of particular importance for the treatment of textile fabrics. The treatment of textile substrates is advantageously carried out in an aqueous medium in which the particular optical brighteners are present in a finely divided form (suspensions, so-called microdispersions and in some cases solutions). Dispersing agents, stabilisers, wetting agents and further auxiliaries can optionally be added during the treatment.

The treatment is usually carried out at temperatures of from about 20° to 140°C, for example at the boiling point of the bath, or in the region thereof (about 90°C). For the finishing, according to the invention, of textile substrates it is also possible to use solutions or emulsions in organic solvents, as are used in dyeing practice in so-called solvent dyeing (pad-thermofix method and the exhaustion dyeing process in dyeing machines).

The optical brighteners which can be used according to the present invention can also be employed, for example, in the following use forms: (a) In mixtures with so-called "carriers", wetting agents, softeners, swelling agents, antioxidants, light stabilisers, heat stabilisers and chemical bleaching agents (chlorite bleach and bleaching bath additives).

(b) In mixtures with crosslinking agents and finishing agents (for example starch or synthetic finishing agents) and also in combination with very diverse textile finishing processes, especially synthetic resin finishes (for example crease resistant finishes such as "wash-and- wear", "permanent press" and "no-iron"), and also flame resistant finishes, soft handle finishes, anti-soiling finshes or anti-static finishes or antimicrobial finishes.

(c) As additives to various soaps and washing agents.

(d) In combination with other substances having an optical brightening action.

If the brightening process is combined with textile treatment or finishing methods, the combined treatment can in many cases advantageously be effected with the aid of corresponding stable formulations which contain the compounds having an optical brightening action in a concentration such that the desired brightening effect is obtained.

In certain cases, the full effect of the brightener is achieved by an after-treatment. This can be, for example, a chemical treatment (for example acid treatment), a thermal treatment (for example heat) or a combined chemical/heat treatment.

The amount of the optical brighteners to be used according to the invention, relative to the material to be optically brightened, can vary within wide limits. A distinct and durable effect can already be achieved with vary small amounts and in certain cases, for example, with amounts of 0.03% by weight. However amounts of up to about 0.5% by weight can also be used. For most cases of interest in practice, amounts of between 0.05 and 0.5% by weight relative to the material to be brightened, are preferably of interest.

In a fourth aspect of the invention, the optical brighteners are also especially suitable as additives for washing baths or to industrial and household washing agents and they can be added in various ways. They are appropriately added to washing baths in the form of their solutions in water or organic solvents or also in a state of fine division as aqueous dispersions or slurries. They, or their components, are advantageously added to household or industrial washing agents at any phase of the manufacturing process of the washing agent, for example to the so-called "slurry" prior to spray-drying of the washing powder or during the preparation of liquid washing agent combinations. The compounds can be added both in the form of a solution or dispersion in water or other solvents and also without auxiliaries in the form of a dry brightener powder. However, they can also be sprayed, in the dissolved or pre-dispersed form, onto the finished washing agent.

Washing agents which can be used are the known mixtures of detergent substances, such as, for example, soap in the form of chips and powders, synthetic products, soluble salts of sulphonic acid half-esters of higher fatty alcohols, arylsulphonic acids, which are substituted by higher alkyl and /or polysubstituted by alkyl, carboxylic acid esters with alcohols of medium to higher molecular weight, fatty acid acylaminoalkyl- or aminoaryl-glycerol- sulphonates, phosphoric acid esters of fatty alcohols and the like. So-called "builders" which can be used are, for example, alkali metal polyphosphates and alkali metal polymeta- phosphates, alkali metal pyrophosphates, alkali metal salts of carboxyethylcellulose and other "soil redeposition inhibitors", and also alkali metal silicates, alkali metal carbonates, alkali metal borates, alkali metal perborates, nitrilotriacetic acid, ethylenediamine-tetraacetic acid and foam stabilisers, such as alkanolamides of higher fatty acids. Furthermore, the washing agents can contain, for example: antistatic agents, superfatting skin protection agents, such as lanolin, enzymes, antimicrobial agents, perfumes and dyestuffs.

The brighteners have the particular advantage that they are also effective in the presence of active chlorine donors, such as, for example, hypochlorite and can be used without substantial loss of the effects in washing baths with non-ionic washing agents, for example alkylphenol polyglycol ethers. Also in the presence of perborate or peracids and activators, for example tetraacetylglycoluril or ethylenediamine-tetraacetic acid are the new brighteners very stable both in pulverulent washing agent and in washing baths.

The brighteners according to the invention are added in amounts of 0.005 to 2% or more and preferably of 0.03 to 0.5%, relative to the weight of the liquid or pulverulent ready-to-use washing agent. When they are used to wash textiles made of cellulose fibres, polyamide fibres, cellulose fibres with a high grade finish, wool and the like, wash liquors which contain the indicated amounts of the optical brighteners according to the invention impart a brilliant appearance in daylight.

The washing treatment is carried out, for example, as follows: The indicated textiles are treated for 1 to 30 minutes at 5° to 100°C and preferably at 25° to 100°C in a wash bath which contains 1 to 10 g kg of a composite washing agent containing builders and 0.05 to 1% relative to the weight of the washing agent, of the brighteners claimed. The liquor ratio can be 1 :3 to 1 :50. After washing, the textiles are rinsed and dried in the customary manner. The wash bath can contain, as a bleach additive, 0.2 g/l of active chlorine (for example in the form of hypochlorite) or 0.1 to 2 g/l of sodium perborate.

The brighteners according to the invention can also be applied from a rinsing bath with a "carrier". For this purpose the brightener is incorporated in a soft rinsing agent or in another rinsing agent, which contains, as the "carrier", for example, polyvinyl alcohol, starch, copolymers on an acrylic basis or formaldehyde/urea or ethylene-urea or propylene-urea derivatives, in amounts of 0.005 to 5% or more and preferably of 0.2 to 2%, relative to the rinsing agent. When used in amounts of 1 to 100 ml, and preferably of 2 to 25 ml, per litre of rinsing bath, rinsing agents of this type, which contain the brighteners according to the invention, impart brilliant brightening effects to very diverse types of treated textiles.

The following Examples serve to illustrate the invention; parts and percentages are by weight, unless otherwise stated.

A. Preparative Examples

Example 1

26.4g. of 4,4'-bis[(4-anilino-6-chloro-1 ,3,5-triazin-2-yl)amino]stilbene-2,2'disulphonic acid disodium salt are stirred in 50ml. of water and 70ml. of ethyl methyl ketone, the mixture heated to 60°C and 3.5g of allylamine and 12.7g. of sodium carbonate added. The mixture is then stirred under reflux for 5 hours, during which time the initial pale yellow suspension changes to a cloudy yellow solution. After cooling to room temperature, the ethyl methyl ketone is removed on a rotary evaporator. The resulting rubbery mass is boiled in 600ml. of water, the pH adjusted to 7-8 by addition of dilute hydrochloric acid and cooled to room temperature. The rubbery mixture is ground in a mixer, filtered with suction, washed with a little water and dried under vacuum at 100°C.

There are obtained 16.5g. of the compound of formula (101) as a yellow powder exhibiting a UV absorption maximum at 354 nm., a fluorescence maximum at 433 nm. and a quantum yield of 0.47. Example 2

To a flask equipped with thermometer, stirrer, pH-electrode and dropping funnel is charged, under an atmosphere of nitrogen, a solution of 18.4g. of cyanuric chloride in 10g. of ice and 200ml. of acetone. After cooling to 0-5°C, a solution of 21.0g. of 80.8% diaminostilbene disulphonic acid in 50ml. of water (previously neutralized with 1N sodium hydroxide solution) is added dropwise over 30 minutes with vigorous stirring, the pH being continuously maintained at 2.5 to 3.0 by the addition of 100ml. of 1 M sodium hydrogen carbonate solution. Subsequently, the mixture is stirred for a further 2 hours at 0-5°C. A solution of 22.6g. of sulphanilic acid sodium salt in 100ml. of water is then added over 10 minutes to the above mixture. The pH is then adjusted to 6.5 to 7.0 by the addition of 36ml. of 15% aqueous sodium carbonate solution, the temperature raised to 50°C and the mixture stirred for a further 4 hours at this temperature.

To the above mixture 11.4g. of allylamine and 21.2g. of sodium carbonate are added with stirring at 50°C. The pH rises to 10.8. The temperature is raised to reflux (60-65°C), whereby the pH drops to 10, and the mixture stirred over night at this temperature. A clear, yellow suspension results having a pH of 9.8. The suspension is evaporated to dryness and dried over phosphorus pentoxide under vacuum. This product is then heated to 110°C in 1000ml. of dimethyl formamide, filtered hot, evaporated to dryness, the product stirred with 200ml. of petroleum ether, filtered and dried under vacuum at 140°C.

There are obtained 32.1 g of compound (102) as a pure yellow powder containing 7% dimethyl formamide, exhibiting a UV absorption maximum at 357 nm. Example 3

To a flask equipped with thermometer, stirrer, pH-electrode and dropping funnel is charged, under an atmosphere of nitrogen, a solution of 18.4g. of cyanuric chloride in 10g. of ice and 200ml. of acetone. After cooling to 0-5°C, a solution of 21.0g. of 80.8% diaminostilbene disulphonic acid in 50ml. of water (previously neutralized with 1 N sodium hydroxide solution) is added dropwise over 30 minutes with vigorous stirring, the pH being continuously maintained at 2.5 to 3.0 by the addition of 100ml. of 1 M sodium hydrogen carbonate solution. Subsequently, the mixture is stirred for a further 2 hours at 0-5°C. A solution of 22.6g. of sulphanilic acid sodium salt in 100ml. of water is then added over 10 minutes to the above mixture. The pH is then adjusted to 6.5 to 7.0 by the addition of 36ml. of 15% aqueous sodium carbonate solution, the temperature raised to 50°C and the mixture stirred for a further 4 hours at this temperature.

To the above mixture 20g. of diallylamine and 21.2g. of sodium carbonate are added with stirring at 50°C. The pH rises to 10.6. The temperature is raised to reflux (60-65°C), whereby the pH drops to 9.6, and the mixture stirred over night at this temperature. A clear, yellow solution results, which is evaporated until a viscous residue is obtained. 300ml. of methanol and a little water are then added and the mixture stirred until a suspension is obtained. The solids are then filtered off and dried at 80°C under vacuum.

There are obtained 106g. of the compound of formula (103) as a yellow powder, exhibiting a UV absoφtion maximum at 350 nm., a fluorescence maximum at 439 nm. and a quantum yield of 0.58.

Example 4

45g. of 91.5% 4,4'-bis[(4-anilino-6-chloro-1 ,3,5-triazin-2-yl)amino]stilbene-2,2'disulphonic acid disodium salt are stirred in 100ml. of water and 140ml. of ethyl methyl ketone, the mixture heated to 60°C and 11.7g of diallylamine and 25.5g. of sodium carbonate added. After stirring for 1 hour at 60°C a further 11.7g of diallylamine are added. The mixture is then stirred under reflux for 5 hours, during which time the initial pale yellow suspension changes to an emulsion and then returns to a suspension. After cooling to room temperature, the mixture is filtered and washed with a little water. The filter cake is then stirred in acetone, filtered and finally recrystallized from 400ml. of ethanol/water. After drying at 80°C under vacuum, 30.8g. of the pure compound (104) are obtained as an almost white powder, exhibiting a UV absorption maximum at 349 nm., a fluorescence maximum at 439 nm. and a quantum yield of 0.55. Example 5

To a well-stirred mixture of 18.4g. of cyanuric chloride and 10g. of ice in 200ml. of acetone is added over 30 minutes at 0°C a solution of 26.1 g. of 65.1% 4,4'-diaminostilbene-2,2'- disulphonic acid in 100ml. of water, previously adjusted to pH 7.5 by the addition of 30% sodium hydroxide solution, the pH being maintained at 2.5 to 3 by the addition of approximately 100ml. of 1 molar sodium hydrogen carbonate solution. A thick yellow suspension results which is stirred for a further 1.5 hours to complete reaction. A solution of 5.7g. of allylamine in 100ml. of water is then added, whereby the pH rises initially to 8.9 and then falls successively. By the addition of approximately 25ml. of 15% sodium carbonate solution, the pH is maintained at 6.5 to 7.0, whilst the temperature is raised to 50°C. After stirring for 1 hour, a yellow suspension results. Finally, at 50°C, a further 5.7g. of allylamine and 12.7g. of sodium carbonate are added in one portion and the temperature raised to reflux (62-65°C). After stirring for 2 hours at this temperature the reaction is complete. The reaction mixture is then evaporated to dryness under vacuum and dried at 100°C.

There are obtained 38.3g. of compound (105) as a yellow powder containing 1.93% water and 10.42% sodium chloride, exhibiting a UV absorption maximum at 347 nm., a fluorescence maximum at 438 nm. and a quantum yield of 0.31. B. Application Examples

a) Pad-thermofixation Process

1.0g/l. of each of the compounds described in Table 1 are dissolved in an aqueous solution containing:

2 g/l. of Tinovetin JUN™

4 g/l. of IrgasolP™ and

10% ethanol.

These mixtures are then applied to 5g samples of bleached cotton and of polyamide by the pad-batch process, the pinch-off effect being 70%. The fabric samples are dried at 60 °C and then thermofixed during 3 minutes at 160°C.

Subsequently, the degrees of whiteness of the fabric samples were measured with the aid of a DCI/SF 500 spectrophotometer according to the method of Ganz (see Table 1).

The so-treated fabric samples exhibit high degrees of whiteness as illustrated in the following Table 1 :

Table 1

b) Exhaust Process

The compounds described in Table 2 are firstly applied to cotton and polyamide fabric samples using the pad-batch process as described in a) above. Subsequently, the cotton sample is added to 200ml. of a liquor containing 10g/l. of sodium sulphate, whilst the polyamide sample is introduced into a bath which was buffered at pH 7 with the aid of a phosphate buffer.

The 2 baths are then heated from 25 to 100°C over 35 minutes, held at 100°C for a further 30 minutes and then cooled to room temperature. The samples are then rinsed, spin-dried and ironed at 160°C.

Subsequently, the degrees of whiteness of the fabric samples were measured with the aid of a DCI/SF 500 spectrophotometer according to the method of Ganz (see Table 2).

The so-treated fabric samples exhibit high degrees of whiteness as illustrated in the following Table 2:

Table 2

Claims

1. A compound having the formula:

wherein each

Ri represents, independently, an allyl- or diallylamino residue; each

R represents, independently, phenylamino which is unsubstituted or substituted by one or more C C -alkyl, halogen, cyano, S0₃M, -SO₂NH₂, S0₂NHd-C₄-alkyl, , -CO₂M, -C0₂C_r C₄-alkyl, -CONH₂, -CONHC_rC₄-alkyl, or -NHCOd-C₄-alkyl groups, with the proviso that the phenylamino group is not substituted by two S0₃Na groups; or an allyl- or diallylamino residue and

M is an alkali or alkaline-earth metal atom, ammonium or a cation formed from an amine.

2. A compound according to claim 1 in which both of the R groups and the R₂ groups are identical.

3. A compound according to claims 1 or 2 in which R₂ represents phenylamino, optionally substituted by a Cι-C₄-alkyl, halogen, cyano, S0₃M, -S0₂NH₂, Sθ₂NHd-C₄-alkyl, -C0₂M, - C-0₂d-C₄-alkyl, -CONH₂, -CONHCι-C₄-alkyl, or -NHCOCι-C₄-alkyl group, M being defined as in claim 1.

4. A compound according to claim 3 in which R₂ represents phenylamino which may be substituted by S0₃M.

5. A compound according to claims 1 or 2 in which R₂ represents allyl- or diallylamino.

6. A compound according to any of the preceding claims in which M is, Na, K, Ca, Mg, ammonium, mono-, di-, tri- or tetra-Cι-C alkylammonium, mono-, di- or tri-C₂-C₄- hydroxyalkylammonium or ammonium that is di- or tri-substituted with a mixture of C C - alkyl and C₂-C -hydroxyalkyl groups.

7. A compound of formula (1) in which R, is allylamino, R₂ is phenylamino which may be substituted by SO₃Na and M is Na.

8. A compound of formula (1) in which R, is diallylamino, R₂ is phenylamino which may be substituted by SO₃Na and M is Na.

9. A compound of formula (1) in which R, and R₂ are allyl- or diallylamino and M is Na.

10. A process for the preparation of a compound of formula (1 ) by reacting, under known reaction conditions, cyanuric chloride, successively, in any desired sequence, with each of 4,4'-diaminostilbene-2,2'- disulphonic acid, an amino compound capable of introducing a group R₂ and an amino compound capable of introducing a group R₁₍ Ri and R₂ being as previously defined.

11. Use of the compounds of formula (1 ) as optical brightening agents for synthetic or natural organic materials.

12. Use of the compounds of formula (1 ) according to claim 11 as optical brightening agents for paper in pulp, size-press or coating applications.

13. Use of the compounds of formula (1 ) according to claim 11 as optical brightening agents for textile materials, especially cotton and polyamide materials as well as mixtures of the same and other synthetic fibres.

14. Use of the compounds of formula (1 ) according to claim 11 as optical brightening agents in detergent compositions.