GB1567782A - Preparations containing dyestuff pigment or optical brightener - Google Patents

Abstract

The colorants or optical brighteners are subjected in aqueous medium to a wet comminution until the particle size of the dispersion is less than 5 microns. After this, the dispersion is thoroughly mixed with a polar, organic solvent which has a limited solubility in the aqueous phase and together with this forms a settled two-phase system in which either, before the mixing, a water-insoluble, natural or synthetic, thermoplastic, organic compound is added as carrier substance to the organic solvent, or the addition of the carrier substance takes place after the mixing. The organic phase containing the carrier substance and colorant or optical brightener is then removed by successive addition of water, and the preparation particles are separated off and freed from the solvent-containing, aqueous phase by washing and drying. The preparations are obtained in pourable, non-dusting, granulated form and can be used for dyeing high-molecular weight organic materials.

Description

(S4) PREPARATIONS CONTAINING DYESTUFF, PIGMENT OR OPTICAL BRIGHTENER (71) We, CIBA-GEIGY AG., a Swiss Body Corporate, of Basle, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be per formed, to be particularly described in and by the following statement: The invention relates to a process for the manufacture of preparations containing a dyestuff, pigment or optical brightener which is sparingly soluble or insoluble in water to the preparations which are obtained in ac cordance with this process and to their use, especially for preparing printing inks, and to the use of such printing inks in the transfer printing process.

The invention will be described mainly with reference to dyestuffs which are at most sparingly soluble in water, i.e. whose solubility in water does not exceed 0.1% by weight at room temperature, but as pre pigment or optical brightener could be paration containing an equally insoluble manufactured in the same way and the word "dyestuff" will where appropriate be under stood to include also a pigment or optical brightener.

The process of the present invention in volves the use of a solvent which has some but limited solubility in water, such that there can be formed a two-phase system containing water in one phase and solvent together with dissolved carrier resins for the dyestuff in the other phase, but the solvent can be extracted from the other phase by diluting the two-phase system with water.

Processes for granulating dyestuffs from a two-phase system are known. As far as pig ments are concerned, reference may be made, for example to U.S. Patent Specification 3,755,244 and to Czechoslovak Patent Specification 121,598. In contrast with the process according to the present invention, these patent specifications disclose solvents which are insoluble and not miscible with water so that, after granulation has been carried out, these solvents must either remain in the granules or be removed therefrom by distillation. This fact constitutes a safety risk and involves the danger of explosions.The preparations manufactured in this way have, moreover, the character of toners, that is to say they are not selfdispersing, as are preparations manufactured according to the present process, presumably because, inter alia, the solvent remaining in the granules causes certain hardening effects on drying.

DOS 2,412,369 also discloses a granulating process which however differs from the process according to the invention in that the solvent also remains in the granules to some extent and that carrier resins are not present. Such carrier-free preparations are also not self-dispersing, if water-insoluble dyestuffs are subjected to this wet granulation process. Processes of this type, the aim of which consists in converting a finely pulverulent substance into a granulated form, are characterised by the quantity of solvent required, which is very low in comparison with the concentration of dyestuff and is preferably about 15 to 50%, relative to the quantity of dyestuff.

In DAS 1,279,658 and 1,669,783, which describe the granulation of substances at elevated temperatures in a two-phase system, the solvent which is employed for the manufacture of the second phase is also completely insoluble in water and constitutes the granulating agent, which remains in the granules. If additional solvents are used at the same time in order to reduce the granulating temperatures, they also remain in the granules or are removed therefrom by distillation.

Furthermore, the manufacture of dyestuff preparation using carrier resins has been disclosed in Swiss Patent Specifications 536;341, 560.234, 565,210 and 557,413. In contrast to these processes, where the dye stuffs are converted into stable dispersions by grinding in the organic solvent, it has now been found that many advantages are obtained if the wet comminution of the dyestuffs, pigments or optical brighteners, which is necessary to achieve the very fine dispersion required, is carried out in the aqueous phase. The present invention makes it possible to do this.

According to the present invention, there is provided a process for the manufacture of preparations containing a dyestuff (or pigment or optical brightener) having little or no solubility in water, which comprises (i) comminuting the dyestuff in water until the particle size of the dyestuff is below 5 microns, (ii) mixing the resultant dispersion with a high molecular weight, thermoplastic water-insoluble, organic carrier resin and with a polar organic solvent having limited solubility in water such that it forms a twophase system therewith comprising water and dissolved solvent as one phase and solvent containing the carrier resin and dyestuff particles as the other phase, and (iii) diluting the two-phase system with water thereby extracting solvent from said other phase and leaving particles of resin coated with particles of dyestuff, and (iv) recovering said particles from the aqueous phase.

By "little solubility" we mean a solubility in water less than 0.01 % at room temperature.

Surprisingly, this has proved feasible, provided certain points are observed. It can be advantageous in this flushing procedure to use auxiliaries such as are known and customary for flushing processes. Besides electrolytes, auxiliaries such as, for example, alkenylhydroxamic acids should be mentioned as such auxiliaries.

The concentration of dyestuff in the dispersion after the flushing procedure has been carried out should not exceed 60%, by weight of the organic phase, and preferablv is within the range 20 to 50%.

The following should be mentioned as the most important advantages which are obtained using aqueous wet grinding: 1. The pigment or the dyestuff can be employed as a press cake and therefore does not need to be dried, which helps to save energy and facilitates comminution.

2. Provided that care is taken during stir rinz the so-called "whipped cream effect", which is due to occluded air which cannot escape, does not occur, the grinding can be carried out in a hiahlv concentrated form, that is to say above 20%, preferably even 30 to 55%, which increases, not only the effectiveness of the grinding, but also its economy in operation.

3. By virtue of the aqueous grinding, it is possible to grind in open mills, in circulation with open vessels and without incurring safety risks.

4. It is possible to manufacture preparations for the most diverse fields of application from one large grinding batch and so to make the schedule of production much more efficient. As is known, different fields of application require corresponding preparations containing specifically adjusted carrier resins. On the other hand, not all of these exhibit the same optimum convertibility in the same two-phase system. If, however, the grinding is carried out in the aqueous phase, it is then possible to divide up the batch in any way desired, in order to manufacture preparations, by coating in the twophase system, in the solvents which are most advantageous for the particular carrier resins. This is also of great importance for the quality and conformity of the preparations, because it is possible to level out differences by virtue of the large batch.

Each production batch of water-insoluble dyestuffs and pigments differs to some extent from the others. Differences cannot, however, be levelled out by mixing together preparations from different manufacturing batches. This must take place in the batch itself. It is clear that the larger the batch can be made, the smaller will become the difficulties in selecting matching production batches of crude pigments. On the other hand, however, too large batches have the disadvantage of inadequate flexibility, if they have to be oriented towards a single end product. The process according to the present invention now opens up the possibility of reconciling the two opposing requirements and of offering an optimum solution.

The following must, however, be taken into consideration: the quality of the preparations depends on the quality of the dispersion which is employed for coating the carrier resin. Just as the dispersion is deposited on the carrier resin, so it is also dispersed again later during application. If grinding is carried out in a solvent, it is possible to ensure that the dispersion is good. If, on the other hand, grinding is carried out in water it is necessary to take into account, as a source of risk for the quality of the dispersion, the additional transference of the dyestuff dispersion into the organic phase. It is decisively important here that the quantity of organic phase is large enough to take up the dispersion, corresponding to its character and degree of grinding, in a stable, deflocculated form.

In no case can this quantity of solvent be smaller than if grinding had been carried out in a solvent. Grinding in a solvent is, rather, the method of choice in order to determine satisfactorily in a preliminarv experiment the quantity of solvent required.

Compared with the state of the art, therefore, the process according to the invention has a number of advantages which are to some extent as unexpected as they are remarkable and contributes a considerable technical advance in the manufacture of readily dispersible preparations from dyestuffs, pigments or optical brighteners.

In a preferred embodiment of the process, a dyestuff press cake is made into paste with water and a water-soluble dispersing agent, care being taken that the press cake does not still contain residues of solvent, from manufacture, which could cause problems in the reaction in the two-phase system. In the case of dried dyestuff, this danger is virtually eliminated. On the other hand, care must be taken in this case that the dyestuff-and the same applies to optical brighteners-is stirred in only very slowly and only at a rate which allows the entrained air to escape again each time.

Even when the dyestuff or the optical brightener has already been brought into a very finely divided form by reprecipitation, it is advisable additionally to carry out a subsequent mechanical grinding with balls or sand.

This wet comminution can suitably be carried out by grinding with sand or with balls of glass, ceramic or metal.

By virtue of the addition of dispersing agent, it is possible to keep the stirred mixture so low in viscosity that it is possible to carry out a rapid and effective grinding at high concentration. The dispersing agents, which are used in a quantity of not more than 5% by weight, should be soluble in water but insoluble in the organic solvent.

They are, above all, anionic or non-ionic dispersing agents, such as, for example, con densation products of benzenesulphonic and naphthalenesulphonic acids with formaldehyde or addition reaction products of ethylene oxide with fatty alcohols or phenols or with a combination of both types.

The carrier resin can be added both to the aqueous phase and to the organic solvent, that is to say before or during, and also after, the formation of the two-phase system. The variant chosen will be that which permits an improved fine dispersion to be achieved. The finer the carrier resin, the greater is its surface and so its capacity for being coated with particles of dyestuff, pigment or optical brighteners. For the coating, the organic solvent, which optionally contains the carrier resin in a dissolved or finelv dispersed form, is added to the dispersion and is then vigorously stirred until the dispersion has passed over completely from the aqueous phase into the organic phase of the two-phase system.If this does not take place itself, assistance must be giVen by the addition of more solvent, and possibly also by the addition of electrolyte, or by means of flushing auxiliaries, such as, for example, water soluble salts of fatty amine derivatives.

The interaction of the dispersion with the carrier resin within the organic phase is preferably carried out at room temperature, if only with a view to the economy of the process. Warming resulting from vigorous stirring is, however, normally not harmful.

In other cases it can be prevented by cooling.

After the combination of the dispersion and the carrier resin has been completed, it is necessary to reduce the organic solvent phase successively by extraction with water.

In the course thereof the preparation breaks down from initially large lumps into smaller and smaller particles. Depending on the type of preparation, it can be advantageous, or even necessary, to assist the process of granulation by wet comminution using mechanical means, for example using a Turmix apparatus. For manufacture on a production scale, continuous apparatuses, such as a Gorator (Gorator is a Registered Trade Mark), are also very suitable. It is important that this process is not carried out only when the granules contain virtually no more solvent and have become hard, since mechanical processing would then lead to undesirable abrasion. The process is best carried out just below the saturation limit of the water with the solvent.If the desired granule size has been achieved, the aqueous phase is poured off and the preparation is taken up in fresh water, so that solvent residues can still diffuse out. This process can be assisted by gentle stirring. The granules are then filtered off on a suction filter or in a filter press, washed with water and then dried. Solvent residues must be removed carefully, since they could give rise to sintering of the carrier resin in the preparation during drying and thus have an unfavourable influence on the redispersibility.

In order to stabilise the dispersion in the organic phase after the flushing process has been completed, it can be advantageous initially to take a portion of the carrier resin in the dissolved form in the solvent. For this purpose, a solvent in which the carrier resin has a certain solubility should be chosen for the second phase. On the other hand, care must be taken not to add to the ground material dispersing agents which are soluble in the organic phase and can pass over into the latter, such as, for example, derivatives of polyvinyl-pyrrolidone, since otherwise inhomogeneous preparations are formed and there can also be an unfavourable effect on the flushing process as such.

Suitable dyestuffs which can be employed in the process according to the invention are, above all, the dyestuffs which are insoluble or sparingly soluble (up to 0.01%) in water and are free from diluents and belong to the category of disperse dyestuffs, metal complex dyestuffs, vat dyestuffs and, preferably, deprotonised, basic dyestuffs. Inorganic and organic pigments of the known categories, as well as optical brighteners which have the character of pigments, should also be mentioned. Which dyestuffs, pigments and optical brighteners are employed in the process according to the invention depends, above all, also on the end use of the preparations.Thus, for example, in order to use the preparations for making up printing inks and employing the latter in the transfer printing process, dyestuffs or optical brighteners will be employed which can be transferred by the action of heat, especially disperse dyestuffs which can be transferred.

Carrier resins which can be uscd are the most diverse, water-insoluble, natural or synthetic, high-molecular, organic compounds. They should not be crystalline but should be amorphous and thermoplastic, should, with advantage, have a solubility of at least 1 ,Ó in the organic solvent forming the second phase, and should have a molecular weight above 350, preferably over 1,000. They can be liquid carrier resins, such as, for example, sucrose acetate, or, preferably, solid carrier compounds. They can belong to the categories of polyamides, polyesters, polyurethanes, polyolefines and polyvinyl and polyacrylic compounds and copolymers of such types, and also to derivatives of colophony and the esters or ethers of polysaccharides.The esters and ethers of cellulose, the polyvinyl acetals, the polyvinyl chloride/vinyl acetate copolymers and modified, especially esterified, derivatives of colophony should be designated as preferred resins which can be used as carrier substances.

Polar organic solvents having limited miscibility with water which can be used are those which have a miscibility gap in the presence of electrolytes and form a twophase system and which have a solubility in water of at least 1%, preferably at least 10 to 30%, at 20"C. They can also be solvents which are in themselves capable of forming a second, separated-out phase with water. They can belong to the categories of ethers, esters, aldehydes or ketones or to aliphatic hydrocarbons which are halogenated, nitrated or possess nitrile groups, but especially to alcohols. Preferred solvents are butanol. ethylglycol acetate, acetoacetic acid ethyl ester and methoxyhexanone. Good results are also achieved with acetvlactone, cyclohexanone and methyl ethvl ketone.

The preparations obtained according to the present process preferably contain from 20 to 90 per cent by weight, and preferably from 70 to 90 percent by weight, of a dyestuff, pigment or optical brightener and between 10 and 30 per cent by weight of carrier resin. They are preparations which are in a granulated form, are free-flowing and non-dusting and can be dispersed very readily. The ready and complete dispersibility in the particular medium of application, usually an organic solution, is, above all, of great importance for a reliable and efficient procedure.

These preparations are used for the most diverse purposes. They are employed, for example, for the bulk dyeing of plastics and for dyeing lacquers. A preferred use is the preparation of printing inks of an aqueous, organic or organic/aqueous nature using a suitable thickener. Suitable organic solvents here are, above all, alcohols, such as ethanol and propanol, while the thickeners employed are preferably those substances which are already used as the carrier resin. While the aqueous printing inks are used above all for the conventional printing of textile materials, the organic and organic/aqueous printing inks are used above all for printing paper and metal foils which, in turn, are then used in the transfer printing process, above all, on polyester material.

The examples which follow are intended to illustrate the invention without, however, limiting it to these embodiments. Parts denote parts by weight in each case and temperatures are quoted in degrees centigrade.

EXAMPLE 1 200 parts of flavanthrone are stirred, as a dry press cake, into a solution of 4 parts of a dispersing agent (for example Tamol NNOK) in 300 parts of water and the mixture is ground with 1,000 parts of Siliquartzit balls of 1 mm diameter until the particle size of the dispersion is below 1 micron.

After separating off the grinding aids and filtration, the resulting dispersion is divided into 5 parts.

a) 100 parts of the dispersion are stirred with 200 parts of cyclohexanone and 26.4 parts of polyacrylonitrile powder are then sprinkled in, while stirring well. After complete mixing has been achieved, the mixture is diluted slowly with water to a volume of 1,000 parts, vigorous stirring being maintained. The aqueous phase is then poured off and the mixture is again made up to the same volume with water and kept for a further hour with gentle stirring. The resulting granular preparation is then filtered off, washed with water and dried in vacuo at 80.

1 part of the preparation is well stirred into 200 parts of a 12% strength solution of polyacrylonitrile in dimethylformamide for 30 minutes on a toothed disc mill. This gives a very fine dispersion, free from agglomerates, of the pigment in the polymer solu tion, which can be shaped to give yellow films or fibres.

b) 100 parts of the dispersion are stirred with 26.4 parts of cellulose acetobutyrate dispersed in 100 parts of sec.-butanol satur ated with water. The mixture is then diluted slowly with 500 parts of water while stirring vigorously, the aqueous phase is poured off, the mixture is again made up to the same volume and is kept for one hour while stirring gently and the preparation is filtered off, washed and dried.

When stirred into an acrylic resin lacquer solution based on toluene, the preparation gives a faultlessly dispersed pigment dispersion.

c) 100 parts of the dispersion are stirred with a dispersion of 26.4 parts of ethylcellu lose in 100 parts of sec.-butanol and the mixture is processed as described under lib).

The resulting preparation can be dispersed very readily in a paper printing ink containing a mixture of nitrocellulose and ethylcellulose as a film forming agent, and gives good prints on paper.

d) 100 parts of the dispersion are stirred with 100 parts of a solution of 26.4 parts of cellulose acetate in ethylene glycol acet ate. 200 parts of water are then added slowly, while stirring vigorously and granulation is then carried out in a Turmix apparatus while adding a further 200 parts of water. The aqueous while adding a further 200 parts of water. The aquous phase is then poured off, the product is taken up in 500 parts of water and the preparation is filtered off after standing for one hour, washed and dried.

1 part of the yellow preparation is dispersed in 200 parts of a 12% strength acetone solution of acetylcellulose and is spun to give fibres. The pigment exhibits a faultless dispersion in the fibres.

e) 100 parts of the dispersion are processed as described under lid), but using, as the carrier resin, 26.4 parts of a colophony derivative which is commercially available under the designation Polypaleester.

The resulting preparation can be stirred in toluene to give a very good dispersion, free from agglomerates, and is suitable for the manufacture of printing inks.

EXAMPLE 2 150 parts of 1 -amino-2-chloro4-hydroxy- anthraquinone are ground in a solution of 3 parts of a dispersing agent (for example Tamol NNOK) in 150 parts of water with the addition of 600 parts of quartz sand, until the dispersion no longer contains particles of more than 5 microns. After separating off the sand, the dispersion is divided into three parts.

a) 100 parts of the dispersion are vigorously stirred with a solution of 5.5 parts of ethylcellulose in 100 parts of sec. -butanol saturated with water. The mixture is then diluted slowly with water, while stirring, up to a volume of 500 parts, the aqueous phase is poured off and the product is taken up in 300 parts of water and again stirred vigorously. The liquid is then again poured off and the product is covered with a layer of 500 parts of water and allowed to stand for one hour and the finely granulated, red powder is filtered off and dried.

1 part of the preparation is dispersed in 9 parts of a 5% strength solution of ethylcellulose in ethanol. A sheet of paper is printed with this printing ink and the print is transferred to a polyester fabric by the thermal transfer process. A good print results.

b) 100 parts of the dispersion are stirred with 100 parts of methyl ethy ketone and, after adding 30 parts of ethylhydroxy-ethylcellulose, the mixture is homogenised vigorously for 10 minutes on a toothed disc stirrer. It is then worked up as described under 2a).

The resulting preparation can be stirred into perchloroethylene to give a stable and agglomerate-free dispersion and can be used for dyeing synthetic fibres, such as, for example. polyester fabrics.

c) 100 parts of the dispersion are stirred with 100 parts of a solution of 14 parts of sucrose acetate and 6 parts of cellulose ace tobutyrate and the mixture is worked up as described above. This gives a red powder which, in a printing ink based on ethanol and methyl ethyl ketone as the solvents and cellulose acetobutyrate as the film forming agent, gives good prints on paper which can be transferred by the thermal transfer process, for example onto polyamide carpets.

EXAMPLE 3 Portions of 100 parts each of copper phthalocyanine in the form of an aqueous press cake from a total of 10 manufacturing batches having a varying residual moisture content are combined and the product is stirred with 3% of a dispersing agent (for example Tamol NNOK), a mobile paste being formed. A solids content determination gives a pigment content of 46%. The dispersion is ground by pendulum action in a type KDL Dyno mill, until the particle size is below 1 micron. The dispersion is then filtered and adjusted to a pigment titre of 40%.

100 parts of the dispersion are vigorously stirred with a suspension of 26.4 parts of ethylcellulose in sec.-butanol. The mixture is then diluted with 500 parts of water, the water is poured off and the product is granulated in a Turmix apparatus with the addition of 300 parts of water. The liquid is again poured off and the product is stirred for one hour in a further 500 parts of water. The blue granules are then filtered off, washed and dried.

The granules are very suitable for paper printing, for example, by means of printing inks based on ethanol and nitrocellulose.

Polyamide powder, polyester powder, polyethylene powder and magnesium behenate- are reacted in an analogous manner using ethylene glycol monoethyl ether acetate as the solvent for the second phase. This gives readily dispersible preparations.

WHAT WE CLAIM IS : - 1. Process for the manufacture of preparations containing a dyestuff (or pigment or optical brightener) having little or no solubility in water, which comprises (i) comminuting the dyestuff in water until the particle size of the dyestuff is below 5 microns, (ii) mixing the resultant dispersion with a high molecular weight, thermoplastic, waterinsoluble, organic carrier resin and with a polar organic solvent having limited solubility in water such that it forms a twophase system therewith comprising water and dissolved solvent as one phase and solvent containing the carrier resin and dyestuff particles as the other phase, (iii) diluting the two-phase system with water thereby extracting solvent from said other phase and leaving particles of resin coated with particles of dyestuff and (iv) recovering said particles from the aqueous phase.

2. Process according to claim 1, wherein the wet comminution is carried out by grinding with sand or balls composed of glass, ceramics or metal.

3. Process according to one of claims 1 or 2, wherein the wet comminution is carried out in the presence of a dispersing agent which is soluble in water but insoluble in organic solvents.

4. Process according to claim 3, wherein the wet comminution is carried out in the presence of not more than 5% by weight of anionic or non-ionic dispersing agent or in a mixture of both.

5. Process according to any of claims 1 to 4, wherein the organic solvent used is a solvent selected from alcohols, ethers, esters, ketones, aldehydes or halogen-, nitro- or nitrile-substituted compounds of aliphatic hydrocarbons having a solubility of at least 1%.

6. Process according to any of claims 1 to 5, wherein a water-miscible solvent which has a miscibility gap in the presence of electrolytes and which forms a two-phase system, is used.

7. Process according to any of claims 1 to 6, wherein the dyestuffs used are disperse dyestuffs, metal complex dyestuffs or vat dyestuffs and the pigments used are inorganic or organic pigments.

8. Process according to any of claims 1 to 7, wherein the carrier resin used is a compound having a molecular weight above 350 and a solubility of at least 1% in the organic solvent forming the second phase.

9. Process according to any of claims 1 to 8, wherein the carrier resin used is selected from esters or ethers of cellulose, polyvinyl acetals, polyolefins, polyamides, polyesters, polyurethanes or polyacrylic or other vinyl polymers.

10. A process according to claim 1, substantially as herein described.

11. A preparation manufactured according to the process of any of claims 1 to 10.

12. A preparation according to claim 11 which contains at least 20 percent by weight and not more than 90 percent by weight of the dyestuff (or pigment or optical brightener).

13. The use of the preparations according to claim 11 or 12 for the bulk dyeing of plastics, for dyeing lacquers or for preparing printing inks of an organic or organic/aqueous nature.

14. Use of printing inks prepared according to claim 13 for printing paper and the use of the printed paper in transfer printing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (14)

**WARNING** start of CLMS field may overlap end of DESC **. addition of 300 parts of water. The liquid is again poured off and the product is stirred for one hour in a further 500 parts of water. The blue granules are then filtered off, washed and dried. The granules are very suitable for paper printing, for example, by means of printing inks based on ethanol and nitrocellulose. Polyamide powder, polyester powder, polyethylene powder and magnesium behenate- are reacted in an analogous manner using ethylene glycol monoethyl ether acetate as the solvent for the second phase. This gives readily dispersible preparations. WHAT WE CLAIM IS : -

1. Process for the manufacture of preparations containing a dyestuff (or pigment or optical brightener) having little or no solubility in water, which comprises (i) comminuting the dyestuff in water until the particle size of the dyestuff is below 5 microns, (ii) mixing the resultant dispersion with a high molecular weight, thermoplastic, waterinsoluble, organic carrier resin and with a polar organic solvent having limited solubility in water such that it forms a twophase system therewith comprising water and dissolved solvent as one phase and solvent containing the carrier resin and dyestuff particles as the other phase, (iii) diluting the two-phase system with water thereby extracting solvent from said other phase and leaving particles of resin coated with particles of dyestuff and (iv) recovering said particles from the aqueous phase.

2. Process according to claim 1, wherein the wet comminution is carried out by grinding with sand or balls composed of glass, ceramics or metal.

3. Process according to one of claims 1 or 2, wherein the wet comminution is carried out in the presence of a dispersing agent which is soluble in water but insoluble in organic solvents.

4. Process according to claim 3, wherein the wet comminution is carried out in the presence of not more than 5% by weight of anionic or non-ionic dispersing agent or in a mixture of both.

5. Process according to any of claims 1 to 4, wherein the organic solvent used is a solvent selected from alcohols, ethers, esters, ketones, aldehydes or halogen-, nitro- or nitrile-substituted compounds of aliphatic hydrocarbons having a solubility of at least 1%.

6. Process according to any of claims 1 to 5, wherein a water-miscible solvent which has a miscibility gap in the presence of electrolytes and which forms a two-phase system, is used.

7. Process according to any of claims 1 to 6, wherein the dyestuffs used are disperse dyestuffs, metal complex dyestuffs or vat dyestuffs and the pigments used are inorganic or organic pigments.

8. Process according to any of claims 1 to 7, wherein the carrier resin used is a compound having a molecular weight above 350 and a solubility of at least 1% in the organic solvent forming the second phase.

9. Process according to any of claims 1 to 8, wherein the carrier resin used is selected from esters or ethers of cellulose, polyvinyl acetals, polyolefins, polyamides, polyesters, polyurethanes or polyacrylic or other vinyl polymers.

10. A process according to claim 1, substantially as herein described.

11. A preparation manufactured according to the process of any of claims 1 to 10.

12. A preparation according to claim 11 which contains at least 20 percent by weight and not more than 90 percent by weight of the dyestuff (or pigment or optical brightener).

13. The use of the preparations according to claim 11 or 12 for the bulk dyeing of plastics, for dyeing lacquers or for preparing printing inks of an organic or organic/aqueous nature.

14. Use of printing inks prepared according to claim 13 for printing paper and the use of the printed paper in transfer printing.