The area of use covered by s-triazinylaminostilbene OWAs is very broad, but of particular interest is the whitening of paper and textile substrates by the class of triazinylaminostilbene derivatives known as the "hexasulphonated" compounds resulting from the use of aniline-2,5-disulphonic acid as one of the substituents. The substantivity- (i.e. the natural affinity of the substance for the fibre) of this class of

OWA to cellulose for example, is generally a function of the number of solubilising groups (particularly sulphonic acids) present. in the molecule: thus, the disulphonic acid derivatives, such as 4,4'-bis(6"-phenylamino-4 ^,1 -morpholino- l",3 ,5"-triazin-2"-yl)aminostilbene-2,2'-disulphonic acid, are very substantive, the tetrasulphonic acid derivatives, such as 4,4'-bis[6"-(4'"-suIphophenylamino)- 4 " - morpholino-1 " ,3" ,5"-triazin-2"-yl]aminostilbene-2,2'-disulphonic acid, are moderately substantive, and the hexasulphonic acid derivatives, such as 4,4'-bis[6"-

(2'" ,5" '-disulphophenylamino)-4"-morpholino-l " ,3 " ,5 "-triazin-2"-yl]aminostilbene-

2,2'-disulphonic acid, are hardly substantive.

We have now found a new group of s-triazinylaminostilbenes which contain a solubilising group (such as sulphonic acid) attached to a methylamino substituent on the triazine ring. This contrasts to the tetra- and hexasulphonic acid derivatives referred to above in which the sulphonic acid substituents are attached to phenylamino groups. Surprisingly, these compounds are stable to acid hydrolysis and have different properties compared to the known tetrasulphonic acid derivatives. In particular we have found that these tetrasulphonic acid derivatives have the substantivity properties of the hexasulphonic acid derivatives of the prior art OWAs. These tetrasulphonic acids are thus especially useful for application to paper either alone, or in combination with other optical whitening agents, dyestuffs, pigments or

other additives by size press or other surface application methods, and to textiles by padding, either alone or in combination with other typical textile finishing additives e.g. acid resins, crease- and water-proofmg agents, or specialist finishes, or during laundering processes as part of detergent or fabric conditioner compositions.

The novel s-triazinylaminostilbene derivatives according to the invention are compounds of formula (1)

in which:

Y is halogen (e.g. fluoro, chloro or bromo), alkoxy (e.g. C alkoxy) or -NR ² R ³ [ where R ² and R ³ are the same or different and are H, alkyl (e.g. C alkyl), hydroxy¬ alkyl (e.g. C _M hydroxyalkyl), or aryl (e.g. phenyl, optionally substituted), or together with the nitrogen atom form a substituted or unsubstituted cyclic amino group having 5-7 ring members, e.g. morpholino or piperidino],

R is H, aryl (e.g. phenyl), which is unsubstituted or substituted (e.g. by one or more electron releasing groups such as C alkyl and/or C _M alkoxy),

R ¹ is H or alkyl (e.g. C _M alkyI, optionally substituted),

Z is an electron-withdrawing group (e.g. CN, -SO^ ),

x is 2 or 3 and

M is H, a metal cation (e.g. alkali metal, such as Na, K or Li) or -N ⁺ R R ⁵ R ⁶ R ⁷ (where R ⁴ -R ⁷ are the same or different and are H, alkyl (e.g. C _M alkyl), aralkyl (e.g. phenyl(C _j . ₆ )-alkyl) or hydroxyalkyl (e.g. C _M hydroxyalkyl)).

Y is preferably bis(2-hydroxyethyl)amino or morpholino. R is preferably phenyl or substituted phenyl, e.g. o, m- or p_-tolyl, anisyl, xylyl or cresyl. R ¹ is preferably H or -CH ₃ and Z is preferably -S0 ₃ M (particularly where M is an alkali metal cation such as Na) or CN.

A compound of particular importance is the compound in which Y is bis(2- hydroxyethyl)amino, R is phenyl, R ¹ is H and Z is -S0 ₃ Na.

The compounds of formula (1) can be prepared by reacting a compound of formula (2)

(where X is halogen (e.g. fluoro, chloro or bromo), Y is halogen (e.g. fluoro, chloro or bromo) or alkoxy (e.g. C^alkoxy) and N(R)CHR ^f Z is as defined above) with 4,4'- diaminostilbene-2,2'-disulphonic acid.

To ensure complete reaction, at least 2 moles of the compound (2) should be added per mole of the disulphonic acid. The reaction can be carried out at any convenient temperature (e.g. 20-60°C or to reflux) in a suitable solvent (e.g. water or aqueous acetone), preferably in the presence of an acid binding agent such as sodium bicarbonate or carbonate.

When a compound in which Y is -NR ² R ³ is required, a compound of formula (1) in which Y is halogen can be reacted with an amine HNR ² R ³ , in generally the same manner as for the preparations of other compounds of formula (1).

The compounds of formula (2), which also form part of the invention, may be

prepared by reacting a cyanuric halide of formula (3)

(where X and Y are as defined for formula (2) above) with an amine of formula (4), RNHCHR'Z. This reaction may be performed as described above for die preparation of the compounds (1), preferably at 0-25°C.

The amines (4) may be prepared by reacting an amine RNH ₂ with an alcohol HOCHR'Z, for example in a neutral aqueous or aqueous alcoholic medium at 20- 60°C.

Alternatively, die compounds of formula (4), (Z=CN) may be prepared from die compound of formula (4) (Z=S0 ₃ Na) by treatment with a soluble cyanide (e.g. NaCN, KCN).

The main applications of me compounds of formula (1), particularly the preferred compounds, lie in the optical whitening of paper and textiles under conditions normally used for me "hexasulphonic acid derivatives" referred to above. However, diey may also be used to treat any other cellulosic or otfier natural, synmetic or semi- syndietic materials to which optical brightening is relevant.

The following Examples illustrate the invention.

EXAMPLE 1

Tetra-sodium 4.4'bis^6"-N-phenyl-N-sulphonatomethylamino-4''-bis( ^' 2" ^, - hydroxyethyl)amino-l".3".5"-triazin-2"-yl]aminostilbene-2.2' -disulphonate

To a solution of sodium N-phenyl-N-(2,4-dichloro-l,3,5-triazin-6-yl)aminomemane sulphonate (37.5g, 0.105g. mol.) in aqueous acetone (375ml) at 20°C containing sodium bicarbonate (8.8g, 0.105 g.mol.) is added a solution of sodium 4,4'- diaminostilbene-2,2'-disulphonate (20.7g, 0.05 g.mol.) in water (140ml) at 20°C. The mixture is then heated up to 50°C and maintained at mat temperature until me reaction is complete (ca. 1 hour). Diethanolamine (12. lg, 0.115 g.mol.) and sodium bicarbonate (8.8g, 0.105 g.mol.) are men added and me solution is heated to 100°C whilst distilling off the acetone and maintained at that temperature for 2 hours. The resulting solution may be used as is, or may be desalinated and concentrated by ultrafiltration to give the title compound as a concentrated solution.

The starting material is prepared as follows:

Sodium N-phenyl-N-(2.4-dichloro-1.3.5-triazin-6-yD aminomethane sulphonate

A solution of cyanuric chloride (19.4g, 0.105. mol.) in acetone (200ml) containing sodium bicarbonate (8.8g, 0.105g.mol.) is cooled to -10°C, and an ice-cold solution of sodium ω -anilinomethane sulphonate (23.0g, OJlOg.mol.) in water (175ml) is added as rapidly as possible and me mixture is allowed to warm up to room temperature. The reaction may be followed by means of HPLC using detection at 265nm to enable visualisation of all me starting products and final products, (including any by-products) to be observed. The resulting solution of me title compound may then be used for further condensations wim nucleophiles, e.g. 4,4'- diaminostilbene-2,2'-disulphonic acid and other amines as required.

The solution of sodium ω -anilinomethane sulphonate is prepared as follows. Aniline (10.2g, 0.110 g.mol) is added to a stirred solution of the sodium salt of the formaldehyde bisulphite addition complex (15.4g, 0.115 g.mol) in water (100ml) at 25-30°C. Formation of the sodium phenylaminomethane sulphonate is complete within 90 minutes (less at higher temperatures) and the solution may then be diluted and cooled and used as described above.

EXAMPLE 2

Tetra-sodium 4.4 ' -b isfό " -N-phenyl-N-sulphonatomethylamino-4 " -morpholino- 1 " .3\5"-triazin-2 ^w -yl1aminostilbene-2.2'-disulphonate

The above compound is prepared by me method of Example 1 except that the diethanolamine is replaced witii morpholine (lO.Og, 0.115g. mol.) to give the corresponding morpholine derivative. The product may be isolated by salting followed by filtration.

EXAMPLES 3-6

The aniline used in the preparation of the starting material in Examples 1 and 2 may be replaced by p-toluidine (11.8g, O.llOg.mol.) or p-anisidine (13.5g, O.llOg.mol.) to give the corresponding derivatives.

The following is a further example of a compound of formula (2).

EXAMPLE 7

N-Phenyl-N-(2.4-dichloro-l .3.5-triazin-6-yl ^' ) aminoacetonitrile

Cyanuric chloride (18.5g) is added all at once to a stirred, ice-cold slurry of phenylaminoacetonitrile (13.9g) in water (150ml) containing sodium bicarbonate (8.4g) and the mixture is allowed to warm up to room temperature. The resulting slurry of the title compound may then be used for further condensations wim nucleophiles, e.g. 4,4'-diaminostilbene-2,2'-disulphonic acid and other amines as required.

The slurry of phenylaminoacetonitrile is prepared as follows. Aniline (9.8g) is added to a stirred solution of glycolonitrile (55% aqueous solution, 11.5g) in water (100ml)

at 20°C, warmed up to 60°C and maintained at mat temperature until the reaction is complete (ca. 1 hour). The resulting oily dispersion may then be cooled and diluted and used as described above.

The following Examples illustrate me use of the compounds of Examples 1 and 2.

Examples A - Size Press Application

Blank handsheets (comprised of 27.2% bleached kraft softwood, 52.8% bleached kraft hardwood and 20% calcium carbonate filler internally sized wim alkyl ketene dimer) are passed through 9% clear starch solution at pH 6 containing 30, 40 and 50 g/1 of OWA (optical strength (E _ll ^ _t )62) and then fed through a size press to squeeze out me excess liquor. The OWAs used are (i) me compound of Example 1 and (ii) Photine ^m SLC Standard (a proprietary brand of "hexa-sulpho" OWA). The sheets are dried (4 minutes at 105°C), conditioned (1 hour at room temperature and 70% R.H.) and men the fluorescence is measured on a Harrison Meter and me brightness on an ICS Q MM 2000 meter, with and without UV filter. To check on the shade and overall appearance, a visual assessment of me two sets of patterns is also made. Typical readings of brightness lift (e-f) obtained are:-

Concentration (g/1 Product from Photine ^m of 62) Example 1 SLC

30 13.1 15.9 40 16.0 16.9 50 17.3 16.8

Visual Assessment

Equivalent to the Photine ^m SLC patterns.

Example B - Padding Application

Patterns of 80 x 80 bleached cotton fabric are passed through solutions of OWAs containing 5,10,15 and 20 g/1 of OWA of optical strength (E^) adjusted to 65, and men fed tiirough a padding mangle at constant pressure to give 100% wt/wt pick-up of liquor. Where a resin finish is employed, the padding solutions contain (in addition to the OWA) 100 g/1 Fixapret ⁰⁰ CPN and 10 g/1 magnesium chloride. The OWAs used are (i) that of Example 2 and (ii) a "hexa-sulpho" OWA based on aniline- 2,5-disulphonic acid and morpholine. The patterns are dried for 5 minutes at 140°C

10 and conditioned for 1 hour at room temperature and 70% R.H. The fluorescence is then measured using a Harrison fluorescence meter and the ISO whiteness by means of a ICS Q MM 2000 meter. Typical readings obtained are:-

(a) Harrison Meter 15

Concentration Water Resin

(g/1 of JjJJ, 65) Product from Hexa-sulpho Product from Hexa-sulpho Example 2 OWA Example 2 OWA

5 309 316 317 335

10 338 347 362 366

15 365 373 382 383

20 369 396 391 386

5

(b) ISO Brightness

Concentration Water Resin

Product from Hexa-sulpho Product from Hexa-sulpho Example 2 OWA Example 2 OWA

5 111.9 113.1 111.5 112.1

10 113.8 114.7 114.9 115.0

15 115.9 117.5 115.8 116.8

20 116.4 119.3 115.5 115.9

10 These results show mat the compound of Example 2 is comparable in performance to me hexa-sulpho compound.