DE2202497A1 - Process for producing images - Google Patents

Description

Process for producing images

The invention "deals with a new process for the production of pictures.

Substances that absorb light and are reversible Repeat color change are commonly referred to as photochromic compounds. These connections generally keep a stable colorless state without the influence of an exciting light such as ultraviolet rays, at. When ultraviolet rays are irradiated thereon, they change to a colored state with it different absorption spectrum. The molecules in this colored state easily revert to the original colorless state due to their instability when the exciting light is removed. If also

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already using numerous patents relating to photo coloring and decolorizing materials this reversibility are known, can be reversed due to the property of these photo coloring and decolorizing Materials when applying the photochromic compounds no permanent images can be obtained, though they were found to be suitable for temporary copying of images. Furthermore is the color shading monochrome and it was impossible to form multicolored images although shaded images could be obtained.

A new process has now been found which can be applied to this temporary as well as to a permanent one Image recording can be applied and in which the color shade can be varied. In detail is contain according to the invention the photochromic compound in an electrophotographic sensitive layer, whereby a sensitive material is obtained which is a photo coloring and decolorizing material, and Has properties as an electrophotographic material, the photochromic compound in a resinous Binder is dispersed in the sensitive material containing the photochromic compound.

That is, the sensitive material is electrically charged in the dark and then image-wise to form of a permanent image, whereupon it is exposed by means of ultraviolet rays in the same manner as in the previous process is colored and is decolorized by means of heat or visible rays. The suspension time is sufficiently short because the electrophotographic sensitivity is far higher than the photosensitivity of photochromism. It is then further treated by an electrophotographic process and a toner image results thereon. If a substance that has a special interaction si it the constituents

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in the sensitive layer shows, as material for Formation of the toner image is used, a new copying process is obtained, which is detailed below is specified.

Depending on the choice, this can be divided into the following four groups:

1) Palis a colorless image using a Toner made from a transparent resin which, for example, may contain an extender, but is free from a parb pigment is formed, whereby the coloration of the photochromic compound is prevented, the photochromic "compound in the area covered with the toner are not colored (colorless) and the uncolored The area is colored by the photochromic !! Connection when irradiating the entire surface colored with ultraviolet rays, making a negative Overall image results and difficulties in distinguishing the image arise. The image is made by suspension reproduced across the entire surface by ultraviolet rays.

As examples of such resin toners, resins can be used as binders for the photochromic sensitive materials are not preferred, e.g. polyvinyl chloride, polyvinylidene chloride, vinyl chloride / vinyl acetate copolymers, Polyhydroxyäthylmethaerylat and Polyvinylpyrrolidon.

2) Palis the image with such a toner that the parbe the photochromic compound due to the polarity if a transparent resin free of color pigment is mixed with this compound, developed the sensitive layer is mixed with the toner layer and a colored positive results Picture even in the dark. In this pail the Non-image area due to exposure of the entire surface to be colored. Examples of such toners are

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ζ. B. cellulose acetate, ethyl cellulose, cellulose acetate butylate, Cellulose acetate phthalate and the like.

3) Palis a toner is used in which the mixture made of transparent resin, free of color pigment, and a photochromic compound is not colored, however is colored when light is irradiated, the development takes place in the area provided with the toner application completely different from that in the non-image area and an image is obtained which is difficult with can be distinguished in the dark with the eyes, but different shades from other areas in the Has suspension of the entire surface.

As such toners, mixtures of resins such as polystyrene, polyvinyl acetate and polymethacrylate with one can be considered third substance mentioned. As examples of such third substances, compounds having a large polarity are cited preferred, which is different from that of the resins with preferably aromatic carboxylic acids and Is phenols, but is not limited only to such compounds. Examples are phthalic acid, Benzoic acid, nitrobenzoic acid, chlorobenzoic acid, oxybenzoic acid, salicylic acid, toluic acid, naphthoic acid, Anthranilic acid, anisic acid, nitrophenol, naphthol, picric acid, chlorophenol, oxyacetophenone, resorcinol, hydroquinone, Oxybenzophenone and the like mentioned.

4) Palis a toner that contains a colored pigment, is used, the color of the image area can be varied according to preference and in one positive image with the non-image area colored when the entire surface is exposed to ultraviolet rays is exposed. The toners to be used for this are not limited to Resins 1 to 3 and

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these can be used as toners after adding colored pigments or coloring agents can be used in these resins.

For example, the following pigments or colorants can be selected to make any desired to get colored toner:

Black: soot

Red: Brilliant Carmine 6B, Quinacridone

Red, Oil red,

Yellow: Hansa yellow, benzidine yellow, oil yellow Blue: phthalocyanine blue, phthalocyanine green

Combinations of photochromic compounds and toner resins can still create any desired image Color and occasionally various varying shades of the tinted areas appear.

According to the invention, a monochromatic or a multicolor image is obtained if the function of these four types of toners are used} for example, the sensitive material is made with a toner of group 1 treated, then the material carrying the first toner image is recharged in the dark and exposed imagewise, to obtain a second latent image which is then obtained with a Group 2 toner so that an image emerges which consists of three areas of different shades, i. H. the image area, the image area of the first toner (colorless) and the image area of the second toner (second shade different that of the non-image area). In this case, the image area of the first toner, if the toner is highly insulating, charged to a high voltage and the light fall-off is quite delayed, so that the second toner can strongly adhere to the first toner image area (in the case of positive-positive development)

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This has no effect on the overall shading of the image, which is not a problem, if so the second toner is also colorless.

In a very advantageous manner, that contained in the sensitive layer according to the invention shows Photochromic compound not only contributes to the property of delivering an image of more than one color the development, but also sensitizes the photosensitivity of the photoconductor, such as poly-N-vinylcarbazole, d. H. behaves as a sensitizer. As photochromic compounds to be used in the context of the invention are as examples those of the general formula

indicated, where R _{1 is} an alkyl radical with 1 to 5 carbon atoms, a substituted alkyl radical with substituents such as carboxyl, cyano or ester groups or a phenyl radical, R ₂ and R, an alkyl radical with 1 to 5 carbon atoms or a phenyl radical or together a group - (CH ₂ ) - form, η the numbers 4 or 5, X a hydrogen atom, a nitro group, a halogen atom, a hydroxycarbonyl or alkoxycarbonyl group, an alkyl radical with 1 to 5 carbon atoms or an alkoxy group and at least more than one of the radicals Y a hydrogen atom , a nitro group, a halogen atom, an aldehyde group or an alkoxy group.

The following compounds are listed as examples of compounds of the above general formula :

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1,3,3-trimethylspiro- (indoline-2, 2 '-2'H-ehromen), 1,3,3-trimethyl-8 "-formy! Spiro- (indoline-2,2 ^! -2'H- chromene), 1,3,3-trimethyl 1-6, 8 -dichlorospiro- (indoline-2, 2 '-2 Ή-chromene),

1,3,3-trimethyl 1-8'-methoxyspiro- (indoline-2,2'-2'H-chromene), 1,3 »3-trimethyl 1-6'-nitrospiro- (indoline-2m2 · -2'H -chromene), 1,3,3-trimethyl 1-6 ', 8'-dibromospiro- (indoline-2,2'-2 · H-chromene), 1,3,3-trimethyl 1-5', 7 ^! -dichloro-6'-nitrospiro- (indoline) -2,2'-2'H-chromene),

1,3,3-Trimethy1-8'-formy1-6'-nitrospiro- (indoline-2,2 »-2» H-chromene),

1,3,3-Trimethy1-8'-methoxy-6 "-nitrospiro- (indoline-2,2'-2'H-chromene),

1-Ethy1-3,3-dimethyl-6'-nitrospiro- (indoline-2,2'-2'H-chromene), 1-propyl-3,3-dimethy1-6'-nitrospiro- (indoline-2, 2 ^! -2'H-chromene), 1-buty1-3,3-dimethy1-6'-nitrospiro- (indoline-2,2'-2'H-chromene), 1,3,3-trimethy1-5- methy1-6'-nitrospiro- (indoline-2,2'-2 ¹ H-chromene),

1,3,3-Trimethy1-5-methy1-8'-methoxy-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

1,3,3rTrimethy1-5-methy1-5 ', 7'-dichloro-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

1,3,3-trimethyl-5-methoxyspiro- (indoline-2,2'-2'H-chromene), 1,3,3-Trimethy1-5-methoxy-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

1,3,3-trimethyl-5-methoxy-8'-raethoxy-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

1,3,3-trimethyl-5-chlorapiro- (indoline-2,2'-2'H-chromene), 1,3,3-trimethyl-5-chloro-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

.1,3 »3-trimethyl-5-chloro-8'-methoxy-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

1,3,3-trimethyl-5-chloro-6, 8'-dibromospiro- (indoline-2,2'-2'H-chron3en),

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1,3,3-trimethyl-5-nitrospiro- (indoline-2,2 '-2' H-chromene), 1,3,3-trimethyl-5,6'-dinitrospiro- (indoline-2,2'-2 · H-ehromen), 1,3,3-trimethyl-5,6'-dinitro-8-methoxyspiro- (indoline-2,2'-2'H-chromene),

1,3,3-triinethyl-5-nitro-6 ', 8'-dibromospiro- (indoline-2, 2' 2 Ή-chrome),

1 ψ 3,3-trimethyl-5-ethoxycarbonyl-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

1,3,3-trimethyl-5-ethoxycarbonyl-8-metboxy-6 -nitrospiro- (indoline-2,2'-2 »H-chromene),

1,3,3-trimethyl-5-ethboxycarbonyl-6 ', 8'-dibromospiro- (indoline-2,2-2'H-chromene),

1-benzyl-3,3-dimethyl-8'-metboxy-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

1-benzyl-3,3-dimethyl-8'-nitroapiro- (indoline-2,2'-2'H-chromene), 1-carboxyethyl-3,3-dimethyl-6 "-nitrospiro- (indoline-2,2'-2 · H-cbromene),

1-carboxyethyl-3,3-dimethyl-8-methoxy-6'-nitrospiro- (indoline-2 , 2 '-2' H-chrome),

1-cyanoethyl-3,3-dimethylspiro- (indoline-2,2'-2'H-chromene), 1-cyanoethyl-3,3-dimethyl-6'-nitrospiro- (indoline-2,2'-2 · H-chromene),

1-cyanoethyl-3,3-dimethyl-8'-methoxy-6'-nitrospiro- (indoline-2,2'-2Ή-chromene),

1-carboxypropyl-3,3-dimethyl-6'-nitrospiro- (indoline-2,2'-2Ή-chromene),

1-carboxypropyl-3,3-dimethyl-B * -methoxy-6'-nitrospiro- (indoline-2 , 2 «-2 · H-chrome),

1-Y-carbethoxypropyl-3,3-dimethylspiro- (indoline-2,2'-2 ¹ H-chromene),

1-Y-carbethoxypropyl-3,3-dimethyl-6 ^l -nitrospiro- (indoline-2,2'-2Ή-chromene),

1-Y-carbethoxypropyl-3,3-dimethyl-8'-methoxy-6'-nitroBpiro- (indoline-2,2-2 H-chromene),

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1 -ti ^ bromobutyl-3,3-dimethylspiro- (in.aolin-2,2'-2 · H-chromene), 1 -ö-Br ombu ty 1-3,3-dimethyl-6 · -nitrospiro- (indoline-2,2 '-2 »H-chromene),

1-6> -Bromobutyl-3,3-dimethyl-8-methoxy-6'-nitrospiro- (indoline-2,2-2 H-chromene),

3,3-dimethyl-1-hydroxyethyl-3piro (indoline-2,2'-2'H-chromene), 3,3-dimethyl-1-hydroxyethyl-6 ^! -nitrospiro- (indoline-2,2'-2'H-chromene),

3,3-dimethyl-1- "hydroxyethyl-8'-mefchoxy-6 ^! -Nitrospiro- (indoline-2, 2 · -2'H-chromene),

3,3-dimethyl-1-methoxyethyl-6-nitrospiro- (indoline-2,2'-2 ¹ H-chromene),

3,3-dimethyl-i-hydroxyethyl-8'-methoxy-6'-nitrospiro- (indoline-2, 2 « -2 'H-chromene),

3,3-Dimethy1-1-methoxyethyl-6'-nitrospiro- (indoline-2,2'-2 ¹ H-chromene),

3,3-Dimethy1-1-methoxyethyl-8 »-methoxy-6'-nitrospiro- (indoline-2 , 2'-2'H-chrome),

3,3-Diinethyl-1-phenyl-6'-nitrospiro- (indoline-2,2'-2'H-chromene),

3,3-dimethyl-1-phenyl-8 »-methoxy-6'-nitrospiro- (indoline-2,2» -2'H-chromene),

1,3-dimethyl-3-äthylspiro- (indoline-2,2'-2'H-chromene), 1,3-dimethyl-3-ethy1-6 »-nitrospiro- (indoline-2,2 · -2'H-chromene), 1,3-dimethyl-3-ethy1-8'-methoxy-6-nitrospiro- (indoline-2,2'-2'H-chromene),

1,3-Dimethy1-3-pheny1-6 »-nitrospiro- (indoline-2,2'-2 ¹ H-chromene),

1'-methyl-6-nitro-2H-chromene-2-spiro-2 -indoline-3'-spiro-1 "-cyclohexane,

1 '-Methyl-ö-nitro ^ H-chroffien ^ -spiro ^ ¹ -indoline-3' -spiro-1 "-cyclopentane.

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As the resins having photoconductivity, the following two groups of compounds are exemplified :

1) polynuclear aromatic vinyl polymers: polymers of Vinyl inaphthalene, vinyl anthracene, vinyl diphenyl, vinyl fluorene, Vinylacenaphthene, vinyl pyrene, vinyl naphthacene, Vinyl perylene and the like.

2) vinyl polymers with heterocyclic side chains: Polyvinyl carbazole, polyvinyl phenothiazine, polyvinyl acridine, polyacryloylcarbazole, polyvinylbenzofuran, polyvinylpyrazoline, Polyvinyl oxazole, polyvinyl fluorene and the like.

The amount of the photochromic compound to be used in the context of the invention is preferably from 0.1 to 10% by weight, based on the photoconductive resin, particularly preferably from 2 to 5 %. '

As the developer for the formation of the images by the electrophotographic process, those can be either from the cascade development or the liquid development be used.

For example, a colorless liquid developer can be made by the following process:

Polyvinyl acetate 2 parts by weight

modified with linseed oil

Alkyd resin, 5 parts by weight

Butyl acetate 30 parts by weight

Toluene x 10 parts by weight

5 parts of the mixed solution of the above ingredients are added dropwise to a mixture of

Kerosene 285 parts

Cottonseed Oil 15 parts

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added and dispersed by ultrasonic waves to obtain a positive charge developer will. An isoparaffin and the like can also be used instead of kerosene. *

The developer can be charged both positively and negatively due to the choice of polymer. as Examples are polyvinyl acetate and ethyl cellulose, that charge positively, and nitrocellulose, polyvinyl chloride, vinyl chloride / yinylacetate copolymers, polyvinylidene chloride, Polyvinylidene fluoride and the like, which charge negatively, are called.

The charge of the cascade developer can be either positive or negative according to the electrification series the resins used to make the positive or negative developers can be varied.

Colored pigments, dyes, or other additives can be added to these resins to suit toners the respective purposes.

To form the sensitive layer, a Solution of the photochromic compound and the photoconductive Resin, dissolved in a suitable organic solvent, on a carrier, for example a transparent film or paper and the like which has been subjected to conductivity treatment and dried. The product obtained in the process according to the invention can be used for multicolored copies, slides, Originals can be used for slides, decorative films and the like and is particularly excellent to fix the photochromic sensitive material.

The following examples serve to further illustrate the invention.

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example 1

A solution of 1 part 1, 3,: 5-trimethyl-5-ethoxycarbonyl-6 · -Nitrospiro- (indoline-2,2'-2 'H-chromene) and 50 parts of a 20 # solution of poly-N-vinylcarbazole in toluene was applied to a polyethylene terephthalate film with a transparent conductive undercoat was coated, so drawn up that the dry film thickness Was 10 microns. The film was colorless and transparent. The sensitive layer can be in the following can be used in both ways:

1) a transparent film with negative UiId is contacted with the layer and irradiated for 30 seconds with an ultraviolet lamp (Toshiba ShL-100 of Tokyo Shibaura Electric Co., Ltd.) from a distance of 15 cm to form a positive image which only is colored in the areas through which the ultraviolet rays passed. If it is left to stand in the dark or is ^{heated to 80 °} C., it develops back into a colorless, transparent film.

2) The colorless film is positively charged in the dark, contacted with a transparent film with a positive image, for 2 seconds with a 20 W fluorescent lamp (Toshiba Neoline FL-20S, of Tokyo Shibaura Electric Co., Ltd.) exposed from a distance of 15 cm and with a liquid colorless toner developer with negative charge, for example a liquid developer with a content of polyvinyl chloride as a toner, developed with the formation of a positive image by the with the toner equipped areas are opaque. If it is in a vapor atmosphere of a solvent that dissolves the toner, is brought, for example trichlorethylene, it becomes transparent and fixed. The picture is difficult with that

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Distinguish eyes. When it is irradiated with an ultraviolet lamp for a total of 30 seconds the light image area is colored blue and gives a negative image in which the image area developed with the toner is transparent. If you can Left in the dark or heated, it becomes discolored and transparent. Example 1 is part of the above specified classification 1.

Example 2

A solution of 1 part 1,3,3-trimethyl-6'-nitrospiro- (indoline-2.2 ^l ~ 2 ^l H ~ chromene) and 50 parts of a 20% solution of poly-N-vinylcarbazole in toluene is used drawn on a polyethylene terephthalate film provided with a transparent conductive undercoat so that the dry film thickness is 10 microns. It shows the above photochromism. The picture is further charged in the same manner as in Example 1 according to the electrophotographic method, exposed imagewise, developed with a cellulose triacetate toner, and fixed in an atmosphere of trichlorethylene to give an image in which the image area is red and the cut image area is colorless. If it is exposed to ultraviolet rays as a whole, the non-image areas become dark blue and the image area becomes reddish-purple.

This example belongs to classification 2 above.

In this example, varying the toner constituents results (Additives and resin) the results summarized in the following table:

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-H-

2202A97

additive resin in the dark Il Color of Total exposure to Color of Il Image Ultraviolet rays Image Color of η rich Color of rich Non-image colorless Non-image reddish- areas Il areas purple PMMA ¹ ) colorless'' Il blue pink 0 \ Il Red reddish- Il Il Il purple TAC ³ ) η Il colorless Il pink Il It dd PMMA Il pale yellow ti bluish- p-oxybenzoic PVAc η ti purple acid TAC η colorless Il pink Il It PS ⁴ ) η Il Il It PMMA η yellow Il bluish- Tinuvin PVAc η If purple 326 ⁵ ) TAC η colorless Il dd Il pink PS Il Il ti Il PMMA Il pale yellow Il reddish- PVAc It It purple Uvinul TAC Il colorless It bluish- M-4O ⁶⁾ purple PS Il pale red ti pink colorless Red PMMA pale yellow Il reddish- p-nitro PVAc It purple phenol TAC Red It bluish purple PS yellow Il purple dd orange Carbon- PMMA. ti dd golb tetrabromide PVAc Il It H TAC ti PS It

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1) PMMAi polymethyl methacrylate

2) PYAc : _; Polyvinyl acetate

3) TAC: cellulose triacetate 4 J PS: polystyrene

5) Tinuvin 326: Ultraviolet absorber from Geigy Co.

6) TJvinul M-40: Ultraviolet absorber from GAE Co.

7) The term "colorless" means "colorless and transparent".

Example 3

The sensitive obtained according to Example 1. material was with a toner made from p-oxybenzoic acid and polymethyl methacrylate Developed, fixed and totally exposed to ultraviolet rays, thereby reducing the photographic area blue and the image area colored pink. It changed to colorless and transparent when heated on 80PC.

This example is part of the above classification 3.

Example 4

A solution of 1 part of 1,3,3-trimethyl-5-methoxy-6 ¹ -nitrospiro- (indoline-2,2 ¹ -2'H-chromene) and 50 parts of a 20 5 ^ solution of polyacennaphthylene in toluene was coated on a polyethylene terephthalate film provided with a transparent conductive undercoat so that the dry film thickness was 10 microns and dried to a transparent picture showing the above photochromism. The film was charged and exposed in the same manner as in Example 1, cascade-developed and fixed with a blue toner, and a positive image was obtained.

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When totally exposed to ultraviolet rays became, the entire surface turned blue and it became difficult to distinguish of the picture. When heated, the high-image area became colorless and a distinct image was obtained.

This example belongs to classification 4 above.

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Claims (12)

Claims Iy method for producing a toner image, wherein an electrostatic latent image is formed on an electrophotographic sensitive layer, the contains a photochromic compound, is formed by the electrophotographic process and with a Toner is developed to form a toner image, characterized in that a toner having the effect is used to indicate the coloration or discoloration or the color shade of the photochromic compound controls in the sensitive layer. 2. The method according to claim 1, characterized in that a resin which the color development of the photochromic compound prevents it from being used as the resin of the toner. 3. The method according to claim 2, characterized in that a polyvinyl chloride, polyvinylidene chloride, Vinyl chloride / vinyl acetate copolymer, polyhydroxyethyl methacrylate or polyvinylpyrrolidone are used will. it. A method according to claim 1, characterized in that a resin which is color-developed when mixed with the photochromic compound is used as the resin of the toner. 5. The method according to claim 4, characterized in that cellulose acetate, ethyl cellulose, gelulose acetate butylate or cellulose acetate phthalate can be used as the resin of the toner. 6. The method according to claim 1, characterized in that a resin whose polarity is different from that of the photochromic Connection is different and that when mixing colored with the compound of greater polarity and exposure to light, is used, thereby reducing the 209832/1075 Parbe of the area provided with the toner different that of the substrate is used as the resin of the toner. 7. The method according to claim 6, characterized in that polystyrene, polyvinyl acetate or polymethacrylic acid ester can be used as the resin of the toner. 8. The method according to claim 6 or 71, characterized in that that phthalic acid, benzoic acid, microbenzoic acid, Chlorobenzoic acid, oxybenzoic acid, salicylic acid, toluic acid, uaphthoic acid, anthranilic acid, anisic acid, Nitrophenol, naphthol, picric acid, chlorophenol, oxyacetophenone, Resorcinol, hydroquinone or oxybenzophenone as compounds whose polarity differs from that of the Resin in the toner are different and the one bigger Have polarity can be used. 9. The method according to claim 1, characterized in that a resin containing a colored pigment, is used as the resin of the toner. 10. The method according to claim 9 »characterized in that that carbon black is used as a black pigment. 11. The method according to claim 9 »characterized in that Brillant Carmine 6B, Quinacridone Red or ÖÜJRed can be used as a red pigment. 12. The method according to claim 9t, characterized in that that Hansa-Yellow, Benzidin-Yellow or Öl-Iellow as yellow Pigment can be used. 13 · The method according to claim 9 »characterized in that that phthalocyanine blue or phthalocyanine green are used as the blue pigment. 209832/1075