ITMI20121220A1 - STYLBENIC COMPOUNDS - Google Patents

Description

Description of the patent for industrial invention entitled:

â € œSTILBENIC COMPOUNDSâ €

The present invention relates to new hydrated compounds of the tertiary alkanolamine salts of a specific compound based on 4,4â € ™ -di-triazinylamino-2,2â € ™ -di-sulfostilbene, characterized by their content of water of hydration, by their crystalline forms, from the process of preparation of the new hydrates and from the use of the new hydrates for the preparation of concentrated aqueous formulations of the same.

State of the art

The use of bleaching agents is well known to impart a higher degree of whiteness to products such as paper, cardboard, fabrics and nonwovens. The most widely used whitening agents in the paper and cardboard sector are the derivatives of the 4,4â € ™ -bis- [1,3,5-triazinyl] -diaminostilbene-2,2â € ™ -disulfonic acid substituted at the ring triazine with aniline groups and alkanolamino groups. The aniline groups can in turn contain other sulphonic groups but, as they increase the water solubility of the relative molecules, they reduce their affinity towards the cellulose fibers making up the paper and lead to lower performances in terms of whiteness. .

For reasons of ease of processing, the paper industry requires these bleaching agents to be supplied in liquid liquid forms of aqueous dispersion or, much more preferably, aqueous solutions stable at least for a few months at temperatures from 5 to 40 ° C.

Stilbenic bleaching agents derived from 4,4â € ™ -bis- [1,3,5-triazinyl] -diaminostilbene-2,2â € ™ -disulfonic acid substituted for the triazine ring with aniline and alkanolamino groups, preferred from this sector, they are not easily soluble in water, therefore the production of the relative concentrated and stable aqueous solutions required in the past the addition of significant quantities, up to 30%, of solubilizing additives such as urea, caprolactam, glycol ethylene and polyglycols.

However, the added solubilizers do not have great affinity for cellulose and do not significantly contribute to the performance of the product resulting in unwanted pollutants at the end of the paper production process. For example, in the case of use of whitening agents in solution formulated with urea, a strong additional pollutant load based on nitrogen by-products and ammonia is introduced into the liquid process effluents.

A further problem derives from the inevitable presence in the solutions of whitening agents of inorganic chlorides, for example sodium chloride, which derives from the synthesis processes of the bleaching agents themselves. In fact, all the industrial processes for the production of stilbenic bleaching agents substituted with triazine, involve the use of cyanuryl chloride as a reagent, whose reaction in successive stages with the various necessary amino products inevitably leads to the generation of large quantities of inorganic chlorides. which are difficult to eliminate.

The residual inorganic chlorides generate instability in the concentrated aqueous solutions of the bleaching agents and it is therefore essential to significantly reduce their content, inevitably resorting to expensive osmotic separation techniques, to obtain compositions stable over time.

US 3012971 describes paper bleaching compositions consisting of concentrated aqueous solutions of 4,4â € ™ -bis- [2-phenylamino-4-diethanolamino-1,3,5-triazinyl] -diaminostilbene-2,2â € ™ - disulfonic or a salt thereof in admixture with alkanolamines, in which the weight proportion of the alkanolamines with respect to the whitening agents varies from 0.5: 1 to 3.0: 1. Since the molecular weight of alkanolamines is much lower than that of bleaching agents, this range reflects a strong excess of alkanolamine compared to the bleaching agent. However, such high amounts of alkanolamines, compared to the whitening power of the composition, are not acceptable from an ecological point of view.

WO 2005/028749 discloses aqueous compositions comprising stilbenic bleaching agents and alkanolamines. No example of a composition comprising a tertiary alkanolamine is described in this document. Furthermore, the problem of the effect of inorganic chlorides on the stability of the solution is not mentioned.

US 2010/0159763 discloses aqueous compositions of fluorescent whitening agents, substituted for the triazine rings with amino propionamide groups, having the following formula:

in which at least 25% of the [M <+>] ions associated with the sulphonic group have been replaced with (CH3) 2NH <+> CH2CH2OH ions. However, in such compositions

It is necessary to reduce the content of inorganic salts with suitable processes

osmosis to ensure the stability of the formulation.

IT 1356016 describes a method for optical paper bleaching

through the use of substantially aqueous suspensions of the compound

having the following formula:

H N H N N N SO3M

N H O <N>

H <H>

N N H

M1O3S N <N>

N N H OH

where M and M1 represent hydrogen, an alkali metal, a metal

alkaline earth or ammonium.

US 6153122 discloses new hydrated compounds of M and M1 = metals

alkaline, alkaline earth or ammonium, having the following formula:

HOHN N N N SO3M1

N x H2O HO HN NH OH N MO3S N N

NNHOH

and capable of producing stable concentrated aqueous suspensions. These compounds are unable to produce stable concentrated aqueous solutions.

Description of the invention

Surprisingly, we have found new hydrated compounds of the salts of

tertiary alkanolamines of formula (I):

HOHN N N N SO3X

R N n H2O HN NH N R XO3S N N

NNHOH

(THE)

where R is hydrogen or the -CH2CH2OH group, X is a group

-HN <+> R1R2R3 in which R1, R2 and R3 are chosen from the group formed by alkyl groups

linear or branched C1-C6, C3-C6 cycloalkyl groups, linear hydroxyalkyl groups

or branched C1-C6, C3-C6 hydroxycycloalkyl groups; and in which at least one of R1,

R2ed R3Ã is a linear or branched C1-C6e hydroxyalkyl group and the number of

moles of water of hydration n is a number between 1 and 80.

The compounds of the invention are capable of producing aqueous solutions

stable concentrates useful for improving the whiteness of many

substrates including textiles and paper. They can also be easily formulated

in detergents so that these can impart to the products with washing

an improved degree of whiteness.

The obtainable solutions are stable even in the presence of significant ones

quantity of salts and in particular of sodium chloride. These solutions are stable regardless of the presence of suitable stabilizers or solubilizers.

This property allows to simplify the production process

avoiding the introduction of the final purification phases of the agent

whitening from salts, such as osmosis.

The hydrates according to the present invention comprise the compounds of

formula (I):

HOHN N N N SO3X

R N n H2O HN NH N R XO3S N N

NNHOH

(THE)

where R is hydrogen or the -CH2CH2OH group, X is a group

-HN <+> R1R2R3 in which R1, R2 and R3 are chosen from the group formed by groups

linear or branched C1-C6 alkyl groups, C3-C6 cycloalkyl groups,

linear or branched C1-C6 hydroxyalkyls, C3-C6 hydroxycycloalkyl groups; and

wherein at least one of R1, R2 and R3 is a linear o hydroxyalkyl group

branched C1-C6e the number of moles of water of hydration n is a number

between 1 and 80.

Preferably the compounds of formula (I) are those in which R is a

group - CH2CH2OH.

Preferably the compounds of formula (I) are the hydrates of the col salts

2- (dimethylamino) ethanol in which X is HN <+> (CH3) 2 (CH2CH2OH).

Preferably n is a number comprised between 10 and 70, more preferably between 15 and 65.

Even more preferably the compounds of formula (I) are the hydrates represented by the compounds of formula (II):

HOHN N N N SO3X

N n H2O HO HN NH OH N XO3S N N

NNHOH

(II)

where X is HN <+> (CH3) 2 (CH2CH2OH) and n is between 15 and 80.

For these compounds, stability in aqueous solution has been verified at temperatures up to 40 ° C and in the presence of high quantities of sodium chloride, for example equal to about 1% by weight of the total weight of the solution.

The compounds of the present invention can be prepared by reacting in aqueous medium, optionally combined with polar solvents such as for example acetone and / or methylethylketone, in succession the cyanuryl chloride with the 4,4â € ™ -diamino stilbene disulfonic acid and the disulfonic acid € ™ aniline in order to obtain a compound of formula (III):

(III)

The compound of formula (III) is then reacted with at least 2 moles of diethanolamine or monoethanolamine, adjusting the pH between 9 and 12 with an appropriate quantity of bases such as for example hydroxides, bicarbonates or sodium or potassium carbonates. The reaction mixture is heterogeneous and heat separates the sodium or potassium salt of the optical bleach which is treated with a strong acid solution, preferably hydrochloric or sulfuric acid, in a quantity at least stoichiometric with respect to the sulphonic groups present. The acid form of the optical bleach is thus obtained.

This is subsequently reacted with at least a stoichiometric quantity of tertiary alkanolamine, preferably 2- (dimethylamino) ethanol in the presence of water in order to obtain the hydrated salts of the present invention by neutralization.

The temperatures of these processes are between -20 ° C and 100 ° C and the pressures between 0 and 10 bar, more preferably between 0 and 3 bar.

In a further aspect, the invention then relates to a concentrated aqueous solution of the hydrates of the present invention comprising:

- from 5 to 95% by weight of at least one compound of formula (I) defined in claim 1 or mixtures thereof;

- from 5 to 95% by weight of water; And

- from 0 to 1% by weight of additives.

The aqueous solution of the hydrates of the invention can also comprise an excess of tertiary alkanolamine with respect to the fluorescent whitening agent of formula (I). It is stable for a long time even in the absence of stabilizing agents and also in the presence of any inorganic chlorides deriving from the production process of the stabilizing agent.

The aqueous solutions of the hydrates of the invention may however comprise further components such as for example further bleaching agents, inorganic salts, surfactants, preservatives, solubilizing agents or organic solvents.

Examples of optical brighteners are tetra and / or hexasulfonated stilbenic optics.

Examples of inorganic salts are sodium chloride, sodium sulfate, ammonium chloride, potassium chloride.

Examples of surfactants are sodium polynaphthalenesulfonates, ethoxylated fatty alcohols.

Examples of preservatives are glutaraldehyde, isothiazolinones, 2-bromo-2-nitropropan-1,3-diol.

Examples of solubilizing agents are polyethylene glycols, urea, caprolactam.

Examples of organic solvents are ethylene and propylene glycols.

The solutions of the hydrates according to the invention are obtained by dissolving the fluorescent agent of formula (I) and preferably the compound of formula (II) in water or in a mixture of water and another water-miscible solvent, possibly subjecting the solution by heating and stirring.

The solutions of the hydrates according to the invention can be used for the bleaching of natural, semi-synthetic or synthetic fibers or of paper.

The solutions containing the hydrates of the invention are used with particular effectiveness in the mixture or mass and also surface treatment of paper and cardboard (size press or glue press, coating or patina).

The hydrates of the invention can also be used in the formulation of detergents capable, with washing, of improving the degree of whiteness of textile and non-textile articles.

The invention will be illustrated below with reference to the following examples.

The number of moles of hydration water â € œnâ € in formulas (I) and (II) of the compounds of the invention was determined by subtracting from the value of the total water content obtainable by weight difference after drying or with the Karl Fischer method the value of the freezing water content obtainable with differential scanning calorimetry measurements.

The specific E11 extinction of the hydrated compounds of the invention and their solutions were determined with the UV-VIS Perkin-Elmer Lambda 35 spectrophotometer in 1 cm cells.

The degree of whiteness D65 / 10 ° CIE Whiteness of the artifacts treated with the hydrates of the invention was determined with the Elrepho LWE450-X Datacolor Reflectometer according to the ISO 11475 standard.

Example 1

62.8 g of 4,4â € ™ -bis- [2-phenylamino-4-diethanolamino-1,3,5-triazinyl] -diaminostilbene-2,2â € ™ -disulfonic acid, were dispersed in a solution of 20, 5 g of dimethylaminoethanol (pH> 8) in 325.2 g of water at 80-90 ° C.

The mixture was completely dissolved.

7 g of NaCl were added to the solution to cause demixing.

The temperature was maintained at 80-85 ° C under stirring until the solid was transformed into an oily organic phase.

Subsequently, the stirring was stopped, it was cooled to 10-15 ° C and the two phases were separated, obtaining 170 g of stable oil phase with E11 equal to 286.4 and consisting of the hydrate corresponding to the compound of formula (II ) with n = 24 (SAMPLE 1A)

Demineralized water was added to the oil in order to have an E11 equal to 116 and clarified on clarcel to obtain a solution of hydrate of formula (II) with n = 46 stable (SAMPLE 1B)

Example 2

161.2 g of 4,4â € ™ -bis- [2-phenylamino-4-monoethanolamino-1,3,5-triazinyl] -diaminostilbene-2,2â € ™ -disulfonic acid, were dispersed in a solution of 51, 5 g of dimethylaminoethanol (pH> 8) in 754.8 g of water at 80-90 ° C.

The mixture was completely dissolved.

20 g of NaCl were added to the solution to cause demixing.

The temperature was maintained at 80-85 ° C under stirring until the solid was transformed into an oily organic phase.

Subsequently, the stirring was stopped, cooled to 10-15 ° C and the two phases were separated, obtaining 320 g of oil with E11 equal to 299.2 and consisting of the hydrate of the corresponding formula (I) in which R = H and n = 21 (SAMPLE 2A).

Demineralized water was added to the oil in order to have an E11 equal to 116 and clarified on clarcel to obtain a hydrate of formula (I) with R = H and n = 35 stable (SAMPLE 2B).

Application tests

The aqueous solutions of the hydrates of Examples 1 and 2 were applied applicatively on paper in slurry, patina and glue press and in a detergent and compared with the results obtained on the same system in the absence of the compounds of the present invention. In all cases it was shown that the degree of whiteness of the articles obtained with the treatments in the presence of the hydrated compounds of the present invention were decidedly higher.

Application example of evaluation of hydrated compounds in dough A fibrous mixture prepared according to the following recipe:

50% long fiber bleached cellulose, 50% short fiber bleached cellulose, with a dry fiber content of 3%, pH 6.8 and Schopper-Riegler refining grade equal to 35 ° SR, has been added with 20% by weight of precipitated calcium carbonate (PCC).

The fibrous dispersion thus obtained was divided into 5 parts.

One portion was left as it is (i.e. unchanged for reference), while the other portions were respectively added with:

0.30% by weight referred to the dry weight of the fiber of sample 1A

0.90% by weight referred to the dry weight of the fiber of sample 1B

0.30% by weight referred to the dry weight of the fiber of sample 2A

0.90% by weight referred to the dry weight of the fiber of sample 2B

These dosages were calculated to have the same extinction value.

After 15 minutes of stirring, laboratory leaflets were prepared using a Rapid Koethen desiccant, on which the degree of whiteness was detected.

The values obtained are shown in the following table 1

Table 1

D65 CIE whiteness optical delta sample

Reference 0 86.76

Sample 1A 0.30% 136.26 49.50 Sample 1B 0.90% 137.37 50.61 Sample 2A 0.30% 135.25 48.49 Sample 2B 0.90% 136.10 49.34

The applicative yield of bleaching agents is quantifiable

by the increase in the degree of whiteness of the paper in comparison with the degree of

reference white.

Application example of evaluation of hydrated compounds in patina

The coated specimens were obtained by applying on the backing paper

type â € œFabriano 2 smoothâ €, having a weight of 110 g / m <2>, one layer

uniform of a patina prepared according to the following recipe:

90 parts of Calcium Carbonate Hydrocarb 90AV

10 parts of Kaolin Hydrafine

10 parts of Acronal S728 synthetic binder

0.8 parts Mowiol 4-98 polyvinyl alcohol

Sodium hydroxide in solution (NaOH 10%) up to pH ~ 9

Demineralized water until final dryness equal to 70%.

The patina thus prepared was divided into 5 parts: one portion was

left as it is (i.e. unchanged by reference, with a dosage of

optical whitener = 0), while the other portions were respectively added with:

0.40% by weight referred to the dry product of the formulation of sample 1A

1.20% by weight referred to the dry product of the formulation of sample 1B

0.40% by weight referred to the dry product of the formulation of sample 2A

1.20% by weight referred to the dry product of the formulation of sample 2B

These dosages have been calculated to have the same degree of

extinction.

After 10 minutes of stirring, each sample was applied to the

backing paper using a laboratory doctor blade; at the end of the application i

specimens were dried at room temperature for one hour.

The values of the degree of whiteness D65 / 10 ° CIE Whiteness measured on

laboratory coated samples are shown in the following table 2

Table 2

D65 CIE optical delta whiteness whitening assay sample

Reference 0 95.65

Sample 1A 0.40% 116.05 20.40 Sample 1B 1.20% 118.17 22.52 Sample 2A 0.40% 114.20 18.55 Sample 2B 1.20% 114.11 18.46

Also in this case, the application yield of the bleaching agents is

quantifiable by the increase in the degree of whiteness of the paper afterwards

the application in comparison with the reference level of whiteness.

Application example of evaluation of hydrated compounds in the press

glue

A solution for the surface treatment of paper in size press, consisting of a C * Film 07311 corn starch weld with final dryness equal to

5.0% was divided into 3 parts;

a portion has been left as it is (i.e. unaltered by reference,

with optical brightener dosage = 0), while the other portions were

respectively additives with:

1.5 grams of 1B sample / liter of formulation

3.5 grams of 2B sample / liter of formulation

After 5 minutes of stirring, each sample was applied to the

backing paper â € œFabriano 2 smooth 110 g / m <2> â € using a

laboratory; at the end of the application the specimens were dried a

room temperature for one hour.

The values of the degree of whiteness D65 / 10 ° CIE Whiteness measured on

laboratory samples are shown in the following table 3.

Table 3

Sample <Whitening dosage> D65 CIE

otticowhiteness <delta> Reference 0 103.35

Sample 1B 1.5 g / l 107.21 3.86 Sample 2B 3.5 g / l 109.39 6.04

Also in this application an increase in the degree of

paper whiteness in comparison with the reference whiteness.

Application example of evaluation of hydrated compounds in a

detergent

The sample of example 1B was formulated at the concentration of

0.52% (specific extinction 116) in a liquid detergent (heavy duty liquid,

table 4) for washing fabrics.

Table 4: composition of heavy duty liquid

Percentage Ingredient

by weight (%) Alkylbenzenesulphonate sodium salt (LAS) 30% C13-C15 ethoxylated fatty alcohol 7 moles (Lutensol AO7) 25% Propylene glycol 15% Ethyl alcohol 6% Coconut fatty acids 14% Optical stilbenes disulfonate example 1B 0.52% 100% water Monoethanolamine up to pH = 8

The detergent formulation was evaluated for

whitening power, carrying out repeated washing on two different types of fabrics

standard:

1) Empa 211 cotton fabric, chemically bleached and without

optical whitener

2) Empa 213 Polyester / Cotton fabric, in a 65/35 ratio, bleached

chemically and without optical brightener.

Experimentally, the fabrics were repeatedly washed with the

same formulation, evaluating the degree of whitening power by means of

reading on the colorimeter of the fabric surface. The reading on the colorimeter is

was carried out before washing, after 3 and after 5 consecutive washes. The

whitening power was expressed using the Berger scale.

As a reference, the same fabrics were washed using the

detergent of table 4 in which the stilbenic optic has not been added, going

100% formula with water.

The experimental conditions are shown below

Linitest washing machine

Water hardness ± 20 ° French

Washing cycle 10 minutes

Number of washes (cycles) 5

Detergent concentration 5 g / L

Weight ratio 10: 1

fabric / washing water

Tested fabrics - Empa 211 cotton fabric, chemically bleached and without optical brightener - Empa 213 Polyester / Cotton fabric, in a 65/35 ratio, chemically bleached and without optical brightener.

Washing temperature 25 ° C

Drying conditions 1 minute at 90 ° C in the Benz Dryer

Elrepho 2000 Colorimeter measuring instrument - Zeiss

Expression degree of whiteness Berger scale

The whiteness results are shown in Table 5

Table 5

Before the 3rd wash 5th wash Fabric Washing formulation

(degree (degree (Berger degree) Berger) Berger)

Optical

EMPA 21180.93 122.50 example 1B132.69

Without optic 80.93 81.10 79.69

Optical 78.40 111.23 119.63 EMPA 213 example 1B

Without optic 78.40 78.25 76.40

Claims (10)

CLAIMS 1. Hydrated compounds of the tertiary alkanolamine salts of formula (I): HOHN N N N SO3X R N n H2O HN NH N R XO3S N N NNHOH (THE) where R is hydrogen or the -CH2CH2OH group, X is -HN <+> R1R2R3in wherein R1, R2 and R3 are selected from the group formed by linear alkyl groups o branched C1-C6, C3-C6 cycloalkyl groups, linear hydroxyalkyl groups or branched C1-C6, C3-C6 hydroxycycloalkyl groups; and in which at least one of R1, R2ed R3Ã is a linear or branched C1-C6 hydroxyalkyl group and the number of moles of hydration water n is a number between 1 and 80. 2. Compounds according to claim 1 wherein the group R is -CH2CH2OH. 3. Compounds according to claim 1 or 2 wherein X is HN <+> (CH3) 2 (CH2CH2OH). 4. Compounds according to one or more of claims 1 to 3 wherein n is a number between 10 and 70. 5. Compounds according to one or more of claims 1 to 4 wherein n is a number between 15 and 65. 6. Compounds according to claims 1-4 of formula (II) HOHN N N N SO3X N n H2O HO HN NH OH N XO3S N N NNHOH (II) where X is HN <+> (CH3) 2 (CH2CH2OH) and n is between 15 and 80. 7. Process for the preparation of the compounds of formula (I) which comprises: a) reaction in aqueous medium, optionally mixed with polar solvents of cyanuryl chloride with 4,4â € ™ -diamino stilbene disulfonic acid and then with aniline to give a compound of formula (III): (III); b) reaction of the compound of formula (III) with at least 2 moles of diethanolamine or monoethanolamine in the presence of sodium or potassium hydroxides, bicarbonates or carbonates, treatment of the precipitated sodium or potassium salts with a strong acid solution in a quantity at least stoichiometric with respect to the sulphonic groups present; c) reaction of the compounds of formula (I) in which X is hydrogen with at least a stoichiometric amount of tertiary alkanolamine, preferably 2- (dimethylamino) ethanol. 8. A concentrated aqueous solution of the hydrates of claims 1-6 comprising: - from 5 to 95% by weight of at least one compound of formula (I) defined in claim 1 or mixtures thereof; - from 5 to 95% by weight of water; And - from 0 to 1% by weight of additives. 9. Aqueous solutions according to claim 7 further comprising bleaching agents, inorganic salts, surfactants, preservatives, solubilizing agents or organic solvents. 10. Use of the solutions of claims 8 and 9 for the bleaching of natural, semi-synthetic or synthetic fibers or of paper in particular in mixture, patina and glue press, and in the formulation of detergents for textile and non-textile products.