2,2'- (VINYLENEBIS ( (3-SULPHONATE-4,1-PHENYLENE) IMINO [6- [BIS (2-HYDROXYPROPYL) AMINO]-1, 3,5-T RIAZINE-4,2- DIYL] IMINO]] BIS (BENZENE-1,4-DISULPHONATE) OF HEXASODIUM AND METHOD FOR MAKING SAME FIELD OF THE INVENTION This invention relates to the product of general formula: in which X is diisopropanolamine, and to a method for making it. Said product is used mainly in the paper industry for the finishing of high-quality papers. Other possible uses of the product described in this invention are the preparation of coating mixtures that contain an appreciable quantity of starch or carboxymethyl cellulose and the whitening of cellulosic fibre garments.

BACKGROUND OF THE INVENTION Known in the art are products of general formula:

These are molecules with a nucleus formed by stylbene and cyanuryl which further include dimethanyl acid as remaining substitutes. More particularly, products are known whose X group is diethanolamine or dipropanolamine.

The first of these products, which contains diethanolamine, is used in the paper industry for whitening paper, as is described in patent JP98226680. The whitening achieved following application of this product reaches a state of saturation, that is, from a certain proportion of said product no further increase in the whitening effect is achieved.

The second product, which contains a dipropanolamine group, is not used in the paper industry but is used basically in the photographic industry, as described in patent US4894313.

Furthermore, no whitening effects are known for the diisopropanolamine group forming part of products similar to the product of general formula described.

DESCRIPTION OF THE INVENTION The product of the invention manages to achieve the whitening effect without the problems of saturation which affect the products known in the state of the art.

This invention relates to a product of general formula:

in which X is diisopropanolamine.

One characteristic of this invention is that the diisopropanolamine group lends the product of general formula (I) a slightly violet hue, which shows itself in an increased degree of whiteness.

This invention also has its object a method for making the product of general formula (I), characterised in that it comprises condensation of the product of formula (II) with the diisopropanolamine group, in which the reaction temperature is between 80 and 120°C and the pH is between 8 and 10.

Preferably, the reaction temperature is between 98 and 100°C and the pH is between 8.5 and 9.

Said compound of formula (II) is prepared by condensation of the product of formula (III) with the product of formula (IV), where the temperature of the added product of formula (IV) is between 75 and 85°C, the reaction temperature is maintained between 50 and 60°C and the pH between 6 and 9.

(III) (IV)

Said compound of formula (III) is prepared by condensation of cyanuryl chloride with the sodium salt of aniline 2,5-disulphonic acid, in which the reaction temperature is between 18 and 21°C and the pH of the reaction is between 1 and 3. More preferably still, the pH of said condensation reaction is between 2 and 2.5. The main application of the product of general formula (I) is in the paper industry for whitening of paper for the finishing of high-quality papers, particularly in the sizing press phase accompanying the starch preparations used in such cases. It should be stressed that application of the product successively causes an increase in the degree of whitening that is not obtained when the traditional products are used. Moreover, the increase of the TV value following use of the state-of-the-art product described in patent J98226680 indicates the start of saturation, which is not the case when the product of the invention is used.

The product of the invention can also be used in coating mixtures if they contain an appreciable quantity of starch or carboxymethyl cellulose.

Finally, the product described in this invention can be used in the textile industry in the continuous process for whitening of cellulosic fibre garments in which a finish with reactive resins is required.

For greater clarity, there follows a more detailed description of the method of the invention, including all the stages in the order in which they occur. As described above, a dispersion of cyanuryl chloride is made to react in an aqueous medium with a solution of the sodium salt of dimethanyl acid, to as to provide a product of formula (III). This reaction is preferably carried out at a temperature between 18 and 21°C, preferably keeping the pH

of the reaction between 2 and 2.5 by means of the controlled addition of caustic soda at 20%, and with the reaction time being approximately 90 minutes. Once this first phase has elapsed, neutralisation is completed, preferably to a pH between 6.5 and 7, by means of the addition of sodium bicarbonate.

Then, as described previously, it is made to react with a solution of the sodium salt of 4,4'- diaminostylbene-2,2'-disulphonic acid, containing sodium carbonate as reaction buffer. The addition of said reagent is carried out rapidly, preferably at a temperature between 79 and 81°C. More preferably still, the temperature of the reaction following addition of the sodium salt of 4,4'-diaminostylbene-2,2'-disulphonic acid must be kept between 54 and 56°C, and the pH of the reaction kept between 6.5 and 7.5.

Once this second condensation has finished, and as described above, the product obtained of formula (II) is made to react with diisopropanolamine, with addition of sodium carbonate to keep the pH to the preferable values of between 8.5 and 9. More preferably still, the reaction temperature is kept between 98 and 100°C.

Once the reaction has finished, the product is filtered, cooled and submitted to a process of desalination. A polyglycol is then added as a support medium for the application and it is brought to the optimum concentration for sale.

In the invention, noteworthy as novel points of the procedure described above are the study and determination of the pH of the first condensation. Said pH provides a rapid reaction of the cyanuryl chloride, preventing premature hydrolysis and, therefore, ensuring the absence of isomers which do not condense later and reduce the whitening power of the product.

Another noteworthy aspect of this invention is, similarly, the study and determination of the temperature of the sodium salt of 4,4'-diaminostylbene-2,2'- disulphonic acid added, and of the reaction temperature.

As in the previous case, said conditions prevent premature hydrolysis of the cyanuryl chloride and incomplete condensation of the 4,4'-diaminostylbene-2,2'-disulphonic acid, with appearance of coloured isomers, which have a very negative effect on the quality of the product.

In all cases, the product of the invention provides a sharp whiteness that is difficult to saturate.

EXAMPLES EXAMPLES OF EMBODIMENT Two examples of embodiment of the product of the invention are outlined below. As is detailed, a number of tests are carried out in the characteristic stages of the invention.

1. To a 1,200-litre polyester vat provided with a Cowles type agitator are added: 700 1 of transferred water cooled to 5°C. Then, and while agitating.

0.4 kg of emulsifier; 2.71 kmol (500 kg) of cyanuryl chloride. When all the product has finished falling it is passed through a colloid mill, falling into the condensation vat.

Dispensing then commences.

2.74 kmol (694 kg) Dimethanyl acid in the form of a 30% sodium salt solution. The temperature is held between 18 and 21°C and left to react for 90 minutes, maintaining the pH

between 2 and 2.5 by the addition of approximately 2.6 Kmol (104 kg) Caustic soda in the form of a 20% solution. Test no. 1. When the reaction has finished, approximately; 0.31 Kmol (26 kg) Sodium bicarbonate in powder form is added until pH 6.5 to 7 is achieved. Test no. 2. This first condensation is passed to the corresponding reactor, followed by rapid addition of 1.3 Kmol (481 kg) 4,4'-diaminostylbene-2,2'- disulphonic acid in the form of sodium salt at 15%, containing 29 kg of sodium carbonate for every 100 kg of 4,4'-diaminostylbene- 2,2'-disulphonic acid, and it is heated to 80°C. At the end of addition, the temperature is raised rapidly to 55°C and maintained for one hour. Upon completion of the maintenance time. Test no. 3. If in order, addition of 3 Kmol (400 kg) Diisopropanolamine in the form of 70% solution 1.35 Kmol (144 kg) Sodium carbonate, temperature raised to 98-100°C and maintained for 90 min. Once the reaction has finished the pH must be between 8.5-9, when there follows addition of 36 kg Dicalite 475 and filtering through a filter press and passing on to

the adjusting vat. It is then cooled to 35°C and submitted to a process of nanofiltering until the sodium chloride content is between 1.5 and 2%, when a support polyglycol is added and it is adjusted to the concentration of the Standard by adding the necessary water.

Final weight: 10,500 kg Density: 1.12 Final pH: 8.5-9 There follows an outline of the various tests carried out: Test no. 1 a) The pH must be 2-2.5. b) Test of total condensation of the cyanuryl chloride, 50 ml of the batch is dissolved in 400 ml of boiling transferred water; the solution must be transparent. c) Test of total condensation of the dimethanyl acid; 50 ml of the batch must not use up more than 0.8 to 1 mil of sodium nitrite 0.1 N.

Test no. 2 The pH must be between 6.5 and 7.

Test no. 3 a) The pH must be between 6.5 and 7.5. b) Test of total condensation of the 4,4'- diaminostylbene-2,2'-disulphonic acid; 50 ml of the batch must not use up more than 0.8 to 1 mil of sodium nitrite 0.1 N.

2. To a polyester vat of 1,200 litre capacity and provided with a Cowles type agitator, are added: 770 1 of transferred water cooled to 5°C ; then, and with agitation 0.4 kg Emulsifier; 2.71 kMol (500 kg) Cyanuryl chloride. When all the product has finished falling, it is passed through a colloid mill, from which it falls into the condensation vat. Dispensing then starts.

2.74 Kmol (694 kg) Dimethanyl acid in the form of a 30% sodium salt solution. The temperature is held between 14 and 16°C and left to react for 90 minutes, maintaining the pH between 1.5 and 1.7 by the addition of approximately 2.6 Kmol (104 kg) Caustic soda in the form of a 20% solution. Test no. 1. When the reaction has finished, addition of approximately 0.31 Kmol (26 kg) Sodium bicarbonate in powder form is added until pH 6.. 5 to 7 is achieved. Test no. 2. This first condensation is passed to the corresponding reactor, followed by addition within some 35 mins. of 1.27 Kmol (481 kg) 4,4'-diaminostylbene-2,2'- disulphonic acid in the form of sodium salt at 15%, containing 29 kg of sodium carbonate for every 100 kg of 4,4'-diaminostylbene- 2,2'-disulphonic acid. At the end of addition, the temperature is

raised to 40°C and maintained for two hours, following which it is raised to 50°C. Upon completion of the reaction time. Test no. 3. If in order, addition of 3 Kmol (400 kg) Diethanolamine in the form of 80% solution 1.88 Kmol (200 kg) Sodium carbonate, temperature raised to 98-100°C and maintained for 90 min. Once the reaction has finished the pH must be between 9- 9.5, when there follows addition of 36 kg Dicalite 475 and filtering through a filter press and passing on to the adjusting vat. It is then cooled to 35°C and submitted to a process of nanofiltering until the sodium chloride content is between 1.5 and 2%, when a support polyglycol is added and it is adjusted to the concentration of the Standard by adding the necessary water.

Final weight: 10,250 kg Density: 1.13 Final pH: 9-9.5 Test no. 1 d) The pH must be 1.5-1.7 e) Test of total condensation of the cyanuryl chloride, 50 ml of the batch is dissolved in 400 ml of boiling transferred water; the solution must be transparent.

f) Test of total condensation of the dimethanyl acid; 50 ml of the batch must not use up more than 1.5 to 1.8 ml of sodium nitrite 0.1 N.

Test no. 2 The pH must be between 6.5 and 7.

Test no. 3 c) The pH must be between 6.5 and 7.5. d) Test of total condensation of flavonic acid; 50 ml of the batch must not use up more than 0.8 to 1 mil of sodium nitrite 0.1 N.

EXAMPLES OF UTILISATION OF THE PRODUCT OF THE INVENTION There follows descriptions of a number of methods for using the product as a whitening agent.

1. On paper in sizing press Water is placed in a receptacle equipped with agitation and heating, and under agitation the necessary quantity of corn or potato starch is added to achieve a solution of suitable viscosity and starch content to be applied. It is then heated up to some 95°C, and when the solution is transparent the required quantity of the product of the invention is added together with a small quantity of sodium chloride to prevent static electricity.

It is then applied in the sizing press and the paper follows on its manufacturing process.

Into a stainless steel vat equipped with heating are placed: 5,000 1 Of cold water, to which are added under agitation 600 kg of corn starch. Agitation is continued and

heating up to 90-95°C applied until the solution becomes transparent. Then: 310 kg Of the product of the invention is added.

1,000 1 Water to cool a little 0.5 kg Sodium chloride This is left under agitation for some 10 minutes, when it is ready to apply. It is added to the sizing press so that it has an absorption of 35%, so that the quantity of Optical on the paper is 1.8%. It is then dried and calendered according to the quality of the paper.

2. On paper in coating mixture In a receptacle equipped with agitation a coating mixture based on water, a small quantity of dispersant, kaolin, CMC and an acrylic resin. Once a good dispersion has been achieved, the required quantity of the product is added.

It is then added on the coating machine.

In a steel vat equipped with good agitation are placed: 3,000 1 Water 6 kg Non-ionic dispersant 280 kg Corn starch solution at 20%, to which are added under good agitation 4,000 kg Kaolin. This is left to disperse, followed by addition of 1,200 kg Acrylic Latex as binder, and finally 170 kg Product of the invention.

This is applied on the coating machine by depositing on the paper between 2 and 5 g/m2 and side. It

is then dried and calendered according to the quality of the paper.

3. On continuous-process cellulosic-fibre fabric An impregnation bath is prepared with water, the necessary quantity of the product of the invention, the finishing resin and the cross-linker. The fabric is passed through a vat containing this bath solution and then drained in a Foulard, leaving the required amount of bath in the fabric. It is then dried and thermofixed for a very short period of time above 110°C.

An impregnation bath is prepared with: 3.000 1 Water 150 kg Reagent resin 30 kg Product of the invention 2 kg Magnesium chloride The fabric is impregnated in the vat of the Foulard and then drained with an 85-90% draining effect, dried at 90-95°C and then thermofixed for 30 seconds at 115-120°C.

4. Comparison in sizing press between the production of the invention and the product of the state of the art described in patent J98226680 CIE degree of whiteness Data MASTER V2.0 Illuminant : D65/10 Whiteness TV TD x y Y State-of-the-art product, 1st 119. 4 0. 4 0. 3036 0.3176 88.5 BATH State-of-the-art product, 2nd 123. 1 0.7 G1 0.3018 0.3154 88.6 BATH State-of-the-art product, 3rd 124.1 0.9 G1 0.3006 0.3141 88.7 BATH State-of-the-art product, 1st 121. 2 0.3 0.3032 0.3168 88.6 BATH State-of-the-art product, 2nd 127. 7 0.5 0.3010 0.3140 88.6 BATH State-of-the-art product, 3rd 129. 7 0.5 0.3008 0.3135 88.6 BATH The results of the table were obtained by colorimetric measurement. The TV parameter is the one called"tone value" ; positive values in this case indicate that the sample has a greenish hue, while negative values mean that it has a reddish hue. The TD parameter is the "Tone deviation", with deviation towards green from Gl to G5 and towards red from R1 to R5.

In the readings of the applications made in the sizing press, the two basic properties of the new product compared with the traditional product can be seen clearly.

In the first place, the increase in the degree of whiteness after application of successive baths is greater in the product of the invention.

In the second place, the increase of the TV value in the state-of-the-art product indicates the start of saturation, which is not the case with the product of the invention.

The final reaction conditions and replacement of the amine in the third condensation were decided upon following many tests by controlling the parameters of the intermediate tests, as indicative of the reaction, and by taking the results of the applications carried out with those tests as final indicator.