CH627202A5 - Process for the preparation of yellow pigment intended for printing inks - Google Patents

Description

The subject of the invention is a process for the preparation of yellow pigment of formula:

50

55

R-Nll-CO-CII-N-N I

co

I

CH „

Cl

N = N-Cïï-CO-NH-R I

co (

CH „

(I)

3

627 202

where R represents the phenyl or naphthyl radical which is unsubstituted or substituted one or more times by an alkyl or alkoxy group or by a halogen atom, by coupling in an acid medium of one mole of the tetrazo compound of 4,4'- diamino 3,3'-di-chlorodiphenyl with 2 moles of acetoacetarylide of formula:

CH3-CO-CH2-CO-NH-R (II)

where R has the meaning designated above, in the presence of a water-soluble salt of zirconium or aluminum, and separation, generally by filtration followed by washing and drying.

In the sense of the invention, the water-soluble salt of zirconium or of aluminum is completely or at least partially soluble in the reaction medium at the end of coupling. This solubility, of at least 0.01 mole per mole of pigment, is essential for obtaining the advantageous results of the invention. Most often, the salt is completely soluble in the reaction medium at the start of coupling.

The amounts of salt used in the reaction range from 0.01 to 5, preferably from 0.05 to 1 and very particularly from 0.1 to 0.5 mole per mole of pigment.

The water-soluble zirconium salt is more particularly one of the following: oxychloride, oxybromide, oxyiodide, tetrachloride, sulfate, nitrate, selenate.

The water-soluble aluminum salt is generally a sulfate, nitrate, chloride, bromide, iodide, chlorate, bromate, perchlorate, lactate.

The end of copultation pH is less than 6 and preferably at least 4 and not more than 5.

Alkyl and alkoxy more particularly denote saturated radicals having from 1 to 4 carbon atoms.

The pigment preferably comprises a radical R corresponding to the formula:

X.

Y- <ÇÔ ^> - (III)

2

in which X, Y and Z represent one of the substituents hydrogen, alkyl, alkoxy or halogen, identical or different, and more particularly hydrogen, methyl, methoxy or chlorine.

The preferred yellow pigments of the invention include R = phenyl and X = Y = Z = H, or X = Y = CH3 and Z = H.

Another example of these yellow pigments includes R = phenyl, X = Y = OCH3 and Y = Cl.

As will be detailed below, the solution of the tetrazo compound is brought into contact with the coupler bath. The latter can be in the precipitated state of its alkaline solution with an acid, generally acetic or formic.

It is also possible to pour the solution of the tetrazo compound on the one hand, and the alkaline solution of the coupler, on the other hand, in a solution buffered to a suitable pH, solution where the coupling will take place.

Copulation generally takes place between 15 and 70 ° C, and most often at ordinary temperature, or at a temperature not exceeding 60 ° C.

The water-soluble salt of zirconium or aluminum is introduced into the reaction medium before or during the coupling, for example according to one of the following methods: the water-soluble salt is added to the coupling agent bath after precipitation thereof; the water-soluble salt, which often has an acidic character, is used to precipitate the coupling agent from its alkaline solution, instead, or in addition to the already mentioned acid necessary for this precipitation; pouring an aqueous solution of the water-soluble salt at the same time as the solution of the tetrazo compound; the coupling is carried out by pouring together the solution of tetrazo compound and an alkaline solution of the coupler in a buffered bath containing the water-soluble salt; the coupling can also be carried out by pouring an aqueous solution of the water-soluble salt together with the solutions of the tetrazo compound and of the coupler; the water-soluble salt can also be added to the solution of the tetrazo compound.

It is possible to remove the water-soluble salt of zirconium or aluminum by acidification, after coupling and io before filtration, until a pH of less than 2 and generally of the order of 1.5 is obtained. .

It is also possible to eliminate the water-soluble aluminum salt by basifying the medium, after coupling and before filtration, until a pH greater than 12 and generally gold-13 of 13 is obtained.

For acidification, a mineral acid such as hydrochloric or sulfuric acid can be used, for example. For alkalinization, caustic soda can be used, for example. After filtration, washing with water until disappearance of the soluble ions in the washing waters.

After elimination of the water-soluble zirconium and aluminum salt by acidification or alkalization, there remains in the pigment after filtration and washing only traces of zirconium or aluminum salt, of the order of at most 0.5% by weight, expressed as zirconium or aluminum metal, and most often significantly less than this figure.

It is also possible not to eliminate the zirconium or aluminum salt, by placing oneself outside of the pH zones defined above for their elimination. Filtration is then most often carried out at the end of coupling pH. A cutting effect occurs, but the Applicant has found that it is accompanied, with equal coloring force, better transparency and liveliness and better gloss than according to the prior art.

Preferably, the suspension of the pigment, after copulation, is brought to a temperature between 25 and 100 ° C, more particularly between 60 and 100 ° C. This heating can take place at the end of coupling pH, or after acidification or alkalinization.

According to a subsidiary method of the invention, it is sometimes advisable, in order to perfect the final development of the properties of the pigment, to incorporate therein, in addition, one or more additives already known for the manufacture of pigments, for example. example those described in French patents 1,226,652.1 246,922 or 1,253,937 already cited and in particular 45 in the examples of these patents; it is also possible to use fatty alcohols or insoluble mineral salts such as barium sulphate; it is also possible to add amines, for example fatty amines or rosinamine (which is the amine corresponding to abietic acid), or other known amines 50 in the preparation of pigments, taking care to n '' use only very low doses, not exceeding 2% of the weight of the pigment.

The invention also relates to the use of the pigment defined above in the preparation of printing inks, such as typographic, flexographic, heliographic or offset inks.

The nonlimiting examples below, in which the parts and percentages are given by weight unless otherwise indicated, illustrate the invention.

60

Example 1

A suspension of Yellow Pigment No. 12 of the Color Index (formula 21,090) (by coupling a mole of the tetrazo derivative of 4,4'-diamino 3,3'-dichlorodiphenyl with 2 moles 65 of acetoacetanilide) is prepared from the following way:

The tetrazotation of 63.5 parts of 4,4'-diamino 3,3'-dichlorodiphenyl is carried out conventionally. On the other hand, 95.6 parts of acetoacetanilide are dissolved with 100 parts by volume

627 202

4

of sodium hydroxide 10 N. Then the arylide is reprecipitated with 140 parts of aluminum sulphate Al2 (SO4) 3.18 H2O dissolved in 750 parts by volume of water.

Before coupling, 100 parts of sodium acetate CH3COONa, 3H20 are added to the coupler suspension. Then pouring into it, maintained at 60 ° C, the solution of 4,4'-diamino 3,3'-dichlorodiphenyl tetrazotée, so that there is never an excess of tetrazo derivative, detectable in pigment formation.

After coupling, the formation is brought to pH = 1.5 with hydrochloric acid, then heated for 1 hour at 95 ° C. It is filtered and washed until the mineral salts in the washing water have disappeared. After drying (60-65 ° C), 148 parts of pigment are obtained.

A fatty ink, containing 20% thereof, has a higher transparency and coloring power than that of an ink made with a pigment obtained under the same conditions, the coupler having been reprecipitated not by aluminum sulphate but with an organic acid (acetic or formic).

The fatty ink is made by grinding the pigment on a laboratory wheel with a varnish for offset ink.

The ink obtained is applied in a thin layer (a few tens of microns) on white paper with a black stripe, a strip making it possible to evaluate the transparency. To judge the coloring force, a part of the ink made up as indicated above is intimately mixed with titanium white ground in offset varnish (equal amount of titanium white and varnish).

This mixture is then drawn on a plate using a calibrated rod, and the coloring force of the application is measured on a densitometer.

Example 2

A suspension of Yellow Pigment 12 is prepared by coupling at 65 ° C., in a "coupling bath" containing 120 parts by volume of 10N sodium hydroxide and 100 parts by volume of 100% acetic acid, as well as 56 parts of aluminum sulphate Al2 (SO4) 3.18 H2O. We sink at the same time in this bath:

the solution obtained by tetrazotation of 63.5 parts of 4,4'-diamino 3,3 '-dichlorodiphenyl,

- the alkaline coupler solution (95.6 parts of acetoacetanilide dissolved by 100 parts by volume of 10N sodium hydroxide).

After copulation, the pigment formation is acidified to pH = 1.5 with hydrochloric acid. Then it is heated for one hour at 95 ° C, filtered, washed and dried. 154 parts of dry pigment are obtained. An ink prepared with the latter has a higher transparency and coloring power than those of an ink made from a pigment obtained under the same conditions, but with a coupling bath not containing aluminum sulphate.

Example 3

A suspension of Yellow Pigment 12 is prepared by coupling as in Example 2. But after coupling, the formation is heated for 1 hour at 95 ° C. at the pH of end of coupling, then filtered, washed and dried.

An ink prepared with the pigment obtained has a coloring power slightly lower than that of Example 2, but has, on the other hand, a still improved transparency.

Example 4

63.5 parts of 4,4'-diamino 3,3'-dichlorodiphenyl are tetrazoted in the conventional manner. On the other hand, 95.6 parts of acetoacetanilide are solubilized with 100 parts by volume of 10N sodium hydroxide.

Then a suspension of Pigment Yellow 12 is prepared by pouring these two solutions together in a "coupling bath", at room temperature, containing 20 parts of zirconium oxychloride ZrOCl2.8HzO and buffered with 74 parts of sodium acetate CH3COONa, 3H20 and 60 parts by volume of 100% acetic acid.

After coupling, the formation is brought to pH = 1.5 with hydrochloric acid, then heated for 1 hour at 75 ° C. After filtration, washing and drying, the pigment, which contains only non-dosable traces of zirconium, is incorporated into a fatty ink. The application of this ink has a coloring power and a liveliness clearly superior to that of an ink obtained with a pigment prepared under the same conditions as those described above, but in the absence of zirconium oxychloride.

Example 5

Copulation of the Yellow Pigment 12 is carried out as in Example 2, but replacing the aluminum sulphate with 32 parts of zirconium oxychloride.

The formation is then basified, to pH = 12, with sodium hydroxide, then, after heating for one hour at 100 ° C, filtered, washed and dried. It contains 4.7% by weight of zirconium metal, out of the 5.7% used.

A fatty ink made with the pigment obtained exhibits, during its application, a high coloring force, a very high transparency and a remarkable liveliness.

Example 6

The preparation is reproduced by coupling with Example 5, then the pigment formation is, after coupling, heated for 1 hour at 65 ° C., filtered, washed and dried. A pigment is obtained having the same remarkable properties as that of Example 5. It contains 2.2% by weight of zirconium metal, out of the 5.7% introduced.

Example 7

A suspension of Yellow Pigment 12 is prepared as in Example 5. But, after copulation, the formation is brought, with hydrochloric acid, to pH = 1.5. After being heated for 1 hour at 65 ° C, the pigment is filtered, washed and dried. It now contains only 0.07% by weight of zirconium metal, out of the 5.7% introduced.

The pigment obtained incorporated into a fatty ink, leads to an impression of very high coloring power, the transparency and the liveliness are also improved compared to those of a print produced from an ink made with a pigment prepared in the same conditions, but in the absence of zirconium salt.

Example 8

A suspension of Yellow Pigment No. 12 is prepared by pouring into a coupling bath, maintained at 65 ° C., containing 27 parts of zirconium oxychloride Zr OCl2,8H20 and buffered with 50 parts by volume of sodium hydroxide 10N and 56 parts by volume of glacial acetic acid:

a solution of 63.5 parts of 4,4'-diamino 3,3'-dichlo-rodiphenyl tetrazotée on the one hand,

- And a solution obtained by dissolving 95.6 parts of acetoacetanilide using 100 parts by volume of 10N sodium hydroxide on the other hand.

After coupling, the pigment formation is heated for 1 hour at 65 ° C, the pigment is filtered, washed until the mineral salts are removed, and dried at 65 ° C. It contains 3.3% by weight of zirconium metal, out of the 3.8% introduced.

A fatty ink obtained with the pigment has a coloring power and a transparency clearly superior to that of an ink made with a pigment prepared in the

5

10

15

20

25

30

35

40

45

50

55

60

65

5

627 202

same conditions, but in the absence of zirconium oxychloride. The liveliness of the application is also remarkable.

If we compare two applications of inks obtained

- one with the pigment of this example

The other with the pigment prepared according to the indications of Example 7 of French patent n ° 1 226 652,

it is found that the pigment of the present example leads to an impression of coloring strength and transparency clearly higher than the pigment according to the prior art. (Both pigments were prepared with the same amount of zirconium oxychloride).

Example 9

Yellow Pigment No. 12 is prepared as indicated in Example 8, but after heating the pigment formation, an alkaline solution of 40 parts of rosin is added. The pigment is then washed and dried as in Example 8. It contains 3.4% by weight of zirconium metal, out of the 3.8% introduced.

The application of an ink prepared with this pigment leads to an even greater transparency than that of an application of ink made with the pigment of Example 8. The liveliness is also remarkable. On the other hand, the coloring force is slightly lower (“cutting” effect due to zirconium resinate).

If we compare in fatty ink, the pigment of this example 5 and that of example 7 of French patent n ° 1 226 652 (compositions containing the same amount of zirconium resinate), it is found that the transparency and the strength coloring are in favor of the pigment prepared according to the invention. Vividness is higher with the pigment in this example.

10

Example 10 to 17

The same examples were respectively reproduced in the case of Yellow Pigment No. 13 (by copulation of one mole of the tetrazo derivative of 4,4'-diamino 3,3'-dichlorodiphenyl with 15 2 moles of acetylaceto metaxylidide).

In Examples 1 to 9, the 95.6 parts of acetoacetanilide were replaced by 109 parts of acetylaceto metaxylidide. The improved properties of the pigmented ink thus obtained are quite comparable to those observed when the pigments according to Examples 1 to 9 are used for the pigmentation of the inks.

VS

Claims (11)

627 202 CLAIMS 1. Process for the preparation of yellow pigment of formula (I) R-NH-C0-CH-fc:? CO I Clio where R represents the phenyl or naphthyl radical which is unsubstituted or substituted one or more times by alkyl, alkoxy or halogen, characterized by the coupling in acid medium of one mole of the tetrazo compound of 4,4'-diamino 3,3'- dichlorodiphenyl with 2 moles of acetoacetarylide of formula (II) (I), Œ3-CO-CH2-CO-NH-R (II), where R has the meaning designated above, in the presence of a water-soluble salt of zirconium or aluminum, and by the separation of the pigment thus obtained. 2. Method according to claim 1, wherein the water-soluble salt of zirconium is an oxychloride, oxybromide, oxyiodu-re, tetrachloride, sulfate, nitrate or selenate. 3. The method of claim 1, wherein the water-soluble aluminum salt is a sulfate, nitrate, chloride, bromide, iodide, chlorate, bromate, perchlorate or lactate. 4. Method according to one of claims 1 to 3, wherein the water-soluble salt of zirconium or aluminum is introduced into the reaction medium before or during coupling. 5. Method according to one of claims 1 to 4, in which R corresponds to formula (III) (III) 6. Method according to one of claims 1 to 5, wherein after coupling is acidified the reaction medium until a pH less than 2. 7. Method according to one of claims 1, 3, 4 and 5, in which, after coupling, the reaction medium is made alkaline until a pH greater than 12 is obtained. 8. Method according to one of claims 1 to 7, wherein after copulation a heating step is carried out at a temperature between 25 and 100 ° C, preferably between 60 and 100 ° C, preferably between 60 and 100 ° vs. 9. Yellow pigment of formula (I), obtained by the process according to claim 1. 10. Use of the yellow pigment according to claim 9 for the preparation of printing inks. 11. Use according to claim 10, characterized in that one or more additives are incorporated into the pigment. 30 N-N-CH-C0-NH-R I CO I cir The diarylide yellow pigments, which designate the product of the coupling of the tetrazo compound of 4,4'-diamino 3,3'-dichlordiphenyl with 2 molecules of arylamide of 15-acetylacetic acid, are used as primers in printing inks. They must not only be shiny, but also with high coloring power, great liveliness and high transparency. This last property is essential when, in three-color printing, yellow is applied as the last color (in offset printing for example, this is generally the case). Various techniques make it possible to achieve good transparency. It is, for example, possible to prepare the azo pigment in the presence of surfactants, or to treat the pigment dispersion with products such as amines, as described in French patent No. 1,428,172. However, the drawback generally encountered with the pigments thus obtained comes from their poor offset behavior: the hydrophilic nature of the pigment particle tends to favor the passage of the ink towards the wetting water, hence an impression of poor quality. Another solution consists in coating the pigment particle with natural or synthetic resins, or with products based on resin acids, according to French Patent No. 2,006,384. But this technique can also have drawbacks, such as a significant decrease in the coloring force, resulting from the cutting effect due to the resin. In French patents Nos. 1,226,652 and 1,246,922, the tititu-40 laire has already described methods making it possible to improve the gloss of certain pigments for inks, by incorporating resins of various metals, zirconium and aluminum among others. It has also found, in accordance with French Patent No. 1,253,937, that bright pigments can be obtained using various acidic organic compounds, in the form of salts of the same metals as above. These organic compounds comprising in particular carboxylic, sulfonic acids and acidic sulfuric esters. Continuing his research in this area, we discovered a new process for preparing pigment. This pigment presents, compared to the state of the art, new and appreciable progress from the point of view of the coloring force, the transparency and the liveliness and the gloss, while avoiding the drawbacks described above.