WO1997046622A1

WO1997046622A1 - Use of natural colorants or synthetic colorants identical to natural ones for the temporary marking or colouring of materials

Info

Publication number: WO1997046622A1
Application number: PCT/EP1997/002685
Authority: WO
Inventors: Günter Gaus; Clemens Sambale; Lutz End
Original assignee: Basf Aktiengesellschaft
Priority date: 1996-05-31
Filing date: 1997-05-26
Publication date: 1997-12-11
Also published as: DE19621966A1; AU3167397A

Abstract

The use of natural colorants or synthetic colorants identical to natural ones selected from the group chlorophyll, flavonoids, retinoids, betalains, carotinides or plant extracts containing these colorants, their natural or synthetic derivatives or mixtures of the colorants, plant extracts containing them or their natural or synthetic derivatives, for the temporary marking or colouring of solid or liquid materials except for foodstuffs.

Description

USE OF NATURAL OR NATURIDENTIC SYNTHETIC DYES FOR TEMPORARY MARKING OR COLORING OF MATERIALS

description

The invention relates to the use of natural or nature-identical synthetic dyes or pigments for the temporary marking or coloring of solid or liquid materials. The invention further relates to inks, inks, lacquers and paints containing dyes selected from the group consisting of chlorophyll, flavonoids, retinoids, betaiains, carotenoids or plant extracts containing these dyes, their natural or synthetic derivatives, or mixtures of the dyes, the dye-containing plant extracts or their natural or synthetic derivatives.

Natural dyes such as carotenoids, chlorophyll, anthocyanins, retinoids, betaiains or flavonoids are widespread in nature. They color in nature e.g. Fruits, anthers, pollen, roots, sprouts, leaves and flowers. Carotenoids are widely used in the coloring of foods such as butter, margarine, cheese, salmon and fruit juices.

Synthetic carotenoids such as ß-carotene, ß-apo-8-carotinal, cantaxanthin, citranaxanthin or astaxanthin, which are identical in nature, are used in the food sector in the form of special formulations for permanent coloring.

Synthetic dyes or pigments are out of the question because of their fastness to use such as, for example, their light fastness for temporary marking or coloring. As a rule, they are not readily biodegradable or have an allergenic effect.

The high light fastness of the synthetic dyes is a problem in some areas. If children paint with felt pens on paper, for example, other objects such as tablecloths, tables, chairs, seat cushions, carpets or children's clothing will get dirty again and again due to the felt pen colors. A cleaning of the soiled objects or clothing is complex and usually not completely possible, so that stains remain. Since the felt-tip pens are also often put in the mouth, the colors must be non-toxic. In medicine, the surgical field is disinfected several times in succession with a colored disinfection solution and marked in the process. The color penetrating deep into the skin only disappears after several days to weeks due to gradual scaling down of the skin. A further disadvantage is that the dyes are generally not harmless.

The object was therefore to provide a dye for temporary marking or coloring, which is non-toxic, ecologically harmless, biodegradable and has no allergenic effect.

It has now been found that natural or nature-identical synthetic dyes have the desired advantageous properties and are suitable for temporary marking or coloring of solid or liquid materials.

Natural or nature-identical synthetic unstable dyes according to the invention are, for example, the following dyes:

• Chlorophyll such as chlorophyll a, b, c, d, bacteriochlorophyll a and their various chlorophyll-protein complexes

• Flavonoids are e.g. Anthocyanidins, chalcones, flavanones, flavones, flavonols, isoflavonoids, their glycosides and alkaline earth or alkali salts such as pelargonidine, cyanidine, dolphinidine, paeonidine, petunidine, malvidin, hirsutidine, tuberidine, apigenidine, aurantinidine, luteoliningin, rosinidine Biochanin, Prunetin, Promiferin, Cladrin, Chrysin, Galangin, Gossypetin, Apigenin, Myricetin, Luteolin, Camphor Oil, Morin, Robinetin, Durmillone, Derrusnin, Chrysin, Baicalein, Prime tin, Wogonin, Aluetin, Sericetin, Acacetin, Populin, Dactin lin, Tamarixetin, Spiraloside, Gardenin, Kanngin, Naringin, Ficinin, Hesperidin, Diosmin, Quercetin, Primuletin, Fisetin, Rhoifolin or Selinon (see Handbook of Naturally Occurring Compounds Vol. I, Eds. Devon, TK, Scott AJ, Academic Press Inc 1975: Flavone p. 117-170, isoflavonoids p. 179-189, biflavonoids p. 191-205, anthocyanidins p. 207-213).

Retinoids such as retinol, retinal, retinoic acids, retrovitamin A, their double bond isomers, their esters (preferably acetate, propionate, palmitate), their glycosides, their galactosides, their ethers, their amides or their synthetic derivatives (DL New¬ ton, WR Henderson and MB Sporn, Cancer Research 40, 3413-3425) • Betaiains such as Betacyane, Betaxanthine, Betanin and their free aglyca

• Carotenoids such as carotenes or xanthophylls. Examples include ß-carotene, lycopene, lutein, astaxanthin, citranaxanthine, canthaxanthin, zeaxanthin, bixin, narbixin, capsorubin, neurosporaxanthin, ß-apo-8-carotinal, violaxanthin, cryptoxanthine, neoxanthine, zeinoxanthine, myonoxanthine, myon , Fucoxanthin, Capsanthin, ß-Apo-8-Carotinsäureethylester, α-Carotin, γ-Larotin, δ-Carotin, ξ-Carotin, Rubixanthin, Plect- taniaxanthin, Flavoxanthin, Phytofluen, Azafrin, Crocetin, Crocin-Z, Neurosporin , ß-zeacarotin, bacteriorulin, decaprenoxanthin, diadinoxanthin, adonirubin. In Carotenoids as Colorants and Vitamin A Precursors (Ed. JC Bauernfeind, Academic Press, 1981: 883-916) or Carotenoids (Vol. IA, Eds. Britton G., Liaaen-Jensen S., Pfander H., 296-316, Vol. 1B, 47-61, 1995) further carotenoids are described which can be used according to the invention.

Carotenoids such as carotenes or xanthophylls are preferably used for the marking or coloring according to the invention. Β-carotene, β-apo-8-carotinal, citranaxanthin, canthaxanthin, astaxanthin, lycopene, zeaxanthin, bixin, norbixin, lutein, capsorubin, capsanthin or neurosporaxanthin are particularly preferably used. Synthetically produced are very particularly preferred

Carotenoids such as ß-carotene, ß-apo-8-carotenal, ß-apo-8-carotenic acid esters, citranaxanthin, canthaxanthin, astaxanthin and zeaxane thin. J. Paust (Chimia, 48, No. 11, 1994: 494-498) gives an overview of the various carotenoid syntheses.

For the marking and coloring according to the invention, plant extracts can advantageously be used directly after the digestion of the corresponding plants or parts of plants without further purification or after purification of the natural dyes or pigments. The dyes can be in the form of their crystals or natural derivatives, e.g. as glycosides or bound to proteins and / or lipids or as free dyes after cleavage e.g. the sugar residues or after chemical modification or derivatization, for example in the form of synthetic isomers, glycosides, esters, ethers or amides or other derivatives.

Plant extracts can be prepared, for example, by extracting the plant material with hot water or solvent, or mortaring the plant material with quartz sand or homogenizing the material with a mixer and other subsequent extraction with water or solvent, for example acetone, ethanol, ether, ethyl acetate or MTB.

Also suitable for the use according to the invention are synthetic dyes or pigments such as flavonoids, retinoids, betaines or carotenoids and / or their crystals or derivatives such as their esters, diesters, ethers, thioethers, polyethers, amides, amines, glycosides, lipids , Protein conjugates, phosphates, carbonates, urethanes, sulfoxides, sulfones, sulfates, nitriles, acrylates, urea, selenium or halogen derivatives or inclusion compounds, for example in dextrins.

The dyes or pigments from chemical synthesis or from plant extracts can be used directly or after formulation. Formulations are for the invention

Use of optimal application forms such as micronizates, which e.g. were produced by precipitation processes (EP-A-0 065 193) and contain dye particles in the size range less than 1 μm, or solubilisates which are obtained according to e.g. EP-A-0 055 817. They are preferably suitable for use in aqueous systems, since they are water-soluble or water-miscible. They are therefore advantageously suitable for aqueous stains, emulsion paints, water-based paints or aqueous pesticide formulations. The durability of the dyes is influenced less by the formulation than by the application. Without a formulation, the dyes can be used directly or in organic solution in solvent-based systems such as in paints or stains.

The formulated dyes or pigments advantageously contain auxiliaries such as powdered or granular carriers, protective colloids such as pectins, lipids, gelatin, lecethin, gum arabic, dextrins, partially hydrolyzed soy protein or casein, emulsifiers, solvents, dispersants, wetting agents, stabilizers , Defoamers, viscosity regulators, hydrophobizing agents, antioxidants such as 2-aminobenzenethiol, t-butylhydroxyisol, t-butylhydroxytoluene, p-toluidine, 1,8-diaminonaphthalene, phenyl-α-naphthylamine, 4-aminodiphenylamine, N, N '- Diphenyl-p-phenylenediamine, 6-ethoxy-2, 2, 4-trimethyl-1, 2-dihydro-quinoline, 1-phenylsemicarbazide, phenothiazine, vitamin E or vitamin C, and optionally other formulation auxiliaries.

The instability of the dyes or pigments and their color tone can be influenced, ie amplified or weakened, as desired by the suitable choice of the auxiliaries or their combination. For example, the duration of the coloring can be extended by adding antioxidants. Also the duration of the coloring can be extended by adding film formers, for example in inks.

Formulations in which the dye or pigment is present in a very finely divided form in the aqueous phase are particularly suitable. Formulations of this type are described, for example, for carotenoids in EP-A-0 055 817 and EP-A-0 065 193.

In the formulation according to EP-A-0 055 817, a solubilizate of β-carotene in water is prepared by heating a dispersion of β-carotene in a nonionic emulsifier, so that a molecularly disperse solution is formed which can be obtained by adding Mixed water micelles of ß-carotene and the emulsifier.

According to EP-A-0 065 193, β-carotene is dissolved in a water-miscible solvent in the presence of a protective colloid and subjected to mixing chamber micronization. A colloidally disperse carotenoid formulation is formed.

Formulations are also advantageously suitable, the carotenoids first being dissolved in oil and then stirred into an emulsifier / water mixture and thus being in finely emulsified form.

All types of formulation can then be spray dried and then e.g. be redispersed in water.

By appropriately grinding the dye particles or crystals, as with the different types of formulation, particle or crystal sizes which are advantageous for marking or coloring can also be produced. Advantageous particle sizes are in the range </ = 10 μm, particularly advantageously below 1 μm, very particularly advantageously below 0.1 μm.

The dyes used according to the invention are so well suited for temporary marking or coloring because they are sensitive to external influences such as temperature, radiation, for example UV light or daylight or the action of oxidizing agents, such as atmospheric oxygen, and fade completely.

As a rule, depending on whether they are used as free or formulated dyes, they are completely faded within a few hours to a few days or weeks. For example, the dyes in emulsion paints bleach within a few hours when exposed to daylight.

If the dyes are used in paints, they will fade on wood, for example, within 1 to 7 days, depending on the incidence of light and light intensity. Dyes used in board marker inks will discolor on the white, rewritable board within a few hours to a day. The dye streaks can be removed at any time with a cloth or sponge without leaving any traces.

According to the invention, materials are temporarily marked or colored that are not otherwise colored for this purpose.

For coloring, the synthetic dyes and pigments or the plant extracts containing dye or pigment can be used directly, after derivatization or formulation or in any mixtures between the different synthetic dyes, pigments, plant extracts and / or derivatizations or formulations. Colloidal, persistent formulations of the dyes are preferred. These formulations have proven particularly useful for carotenoids.

According to the invention, the dyes or pigments are used in inks, i.e. in writing liquids which contain very little or no binding agent in addition to the water-soluble dye, for fountain pens, ink pens, ballpoint pens, ball pens, fiber or felt pens or for inkjet printers, or in ink, i.e. in writing liquids that contain a pigment suspension or a color solution containing a large amount of binder. Wax crayons can be colored with dye formulations in powder form.

Further expedient uses of the unstable dyes and pigments are lacquers which are suitable for lacquering or electrophoretic coating of metal, ceramic, porcelain, stone, wood or plastic; Paints such as water, emulsion paints, oil paints, synthetic resin paints or silicate paints for painting, spraying, dipping, flooding or electropheretic coating; Stamping inks for, for example, ink pads, ink ribbons, copy paper or ink sheets; Printing inks for, for example, letterpress, flat, gravure and throughprint in book, offset, screen, flexo and gravure printing. According to the invention, the unstable dyes or pigments are also used for marking or coloring in leather, textile, wood, paper or wallpaper manufacture.

The dyes or mixtures thereof are advantageously used for coloring where the inherent color allows the materials to be clearly marked by the dyes according to the invention.

Further examples of use according to the invention are the short-term marking of operating fields by means of a disinfectant solution containing dye or colored pencils on the skin or the temporary coloring of crop protection agents or fertilizers for checking the area already treated, the marking in the packaging area of labels, the packaging film of a perishable product , so that a quality control of the product is possible by the fading of the unstable dye or pigment in the labels, the film or the product in the event of improper storage (eg long exposure to light or temperature).

The dyes in the labels, films or in the product thus indicate the integral load on the product due to the degree of their fading. Such labels can also be used to easily measure the incidence of light on a plant over a longer period of time. For this purpose, the colored label is impregnated against water and applied at a suitable point within the planting.

Another possible application is to mix with other unstable or stable real colors. In the case of real colors, a color change is then obtained by bleaching out the dyes.

Like the formulations, depending on the matrix to be colored, carotenoids, for example, can also be used directly to achieve a temporary coloration. The light instability of the carotenoids can be used to advantage to indicate the exposure of materials that are sensitive to sunlight and weather. Such a material is, for example, spinnaker nylon, which embrittles after a certain period of use and tends to tear. By dyeing the nylon fiber with carotenoids, a coloring can be achieved which indicates the stress on the material due to its slow fading. The bleaching effect can be used advantageously for other applications. This makes it possible to produce pens for writing on boards that are only briefly described for presentation purposes and can be cleaned with a dry fleece. When, for example, β-carotene is used as the pigment, the annoying, permanently coloring abrasion of pigments is avoided. Furthermore, β-carotene can be used in film pens, which can be used for the explanatory labeling of films during a presentation. After a short storage time, the additional labeling has disappeared again and the user has his professional looking original film again.

The colloidally disperse carotenoid formulations described above can be converted into a water-dispersible powder after drying. This powder can be used to produce an ink which is viscous enough for use in ballpoint pens.

Other uses of the dyes according to the invention are characteristic drawings of the pattern in the textile and leather sector with, for example, appropriate ballpoint pens or felt-tip pens instead of the customary chalk which has to be removed by post-treatment, the addition of the dyes to cleaning, hygiene or impregnating sprays for the temporary marking and thus control of the treated or cleaned area or the marking of wild animals for the study of their habits. The dyes can also be used for flow studies in rivers, streams or in the air or for marking underground water courses or glaciers and thus elucidating their course and their migration.

The following examples serve to further illustrate the invention without restricting it in any way.

Examples:

Example 1:

A standard felt pen is filled with ß-carotene solubilisate with a weight concentration of 4%. The solubilizate has an average particle size of the β-carotene particles of approximately 20 nm. Due to this small particle size, the dye is evenly absorbed by the absorbent fleece, which stores the ink. The felt pen filled in this way results in an even orange-yellow line. To demonstrate bleaching, this area is used to evenly coat an area of approx. 30 mm by 30 mm and measure the color of this area as a function of the exposure time. A matching chamber with illuminant D65 is used as the exposure source, the same piece of paper but an unstained area is used as reference.

The color values obtained in this way are converted into color distances ΔE * (CIELAB system) and plotted as a function of time. The results of this application are shown in FIG. 1 (bleaching of felt pen strokes on paper under illumination with D65 light).

Example 2:

A standard white board is written with the felt pen according to Example 1. The line disappears overnight. There remains on the board a thin, colorless coating of the solubilizer used, which does not interfere with the further labeling, but is an advantage when cleaning because it is a nonionic emulsifier. In addition, the line obtained can be immediately removed again with the fleece belonging to the table.

Example 3:

As in Example 1, β-carotene solubilizate is used. However, the solubilizate is knife-coated onto paper in order to obtain a uniform, extremely intense color. The stained paper is bleached again under D65 light and the color difference to an untreated paper surface is noted as a function of time (see FIG. 2). A delay is observed at the beginning of the bleaching, which is due to the fact that the staining was already in the saturation color value of the solubilizate. Then, as with the felt pen stroke, rapid bleaching is again obtained until there is no color difference to the untreated paper.

Example 4:

A commercially available ball pen is emptied and the ink is replaced by ß-carotene solubilisate. You get an even line without a gradient on the paper, so that you can write very well with the pen. The dark yellow writing fades overnight.

Example 5:

100 g of commercially available emulsion paint for woodchip wallpaper are stained with 0.06 g of a 4% ß-carotene solubilisate (24 ppm ß-carotene in the paint). A clear yellow color is obtained. The color obtained in this way is applied to woodchip wallpaper. wear and then the color difference between this surface and a comparison surface without β-carotene staining is determined. To determine the color difference, measurements are made in reflection and the ΔE * is calculated according to CIELAB. The values obtained are listed in the table below and in FIG. 3 (fading of woodchip wallpaper coated with β-carotene solubilizate).

1 5, 96

2 2, 94

3 1, 65

4 1, 05

5 0, 86

6 0, 82

7 0, 82

8 0.85

9 0, 83

The remaining color difference of 0.8 is within the range of the reproducibility of the paint application and is essentially due to the rough structure of the woodchip wallpaper.

Example 6:

Commercial Desmodur / Desmophen varnishes or acid-curing PV varnishes were colored with β-carotene solubilizate, as described in Example 5. To color polyurethane lacquer, the β-carotene solubilizate was previously diluted with a solubilizer (coloration as in Example 5). Wooden buttons were painted with the varnish. The color fades to the level of the unpainted control buttons within a week.

Claims

claims

1. Use of natural or nature-identical synthetic dyes selected from the group chlorophyll, fla¬ vonoide, retinoids, betaiains, carotenoids or plant extracts containing these dyes, their natural or synthetic derivatives, or mixtures of the dyes, the dye-containing plant extracts or their natural or synthetic derivatives for temporary use

Marking or coloring of solid or liquid materials except food.

2. Use according to claim 1, characterized in that carotenoids are used as the dye.

3. Use according to claims 1 or 2, characterized gekennzeich¬ net that carotenes or xanthophylls are used as carotenoids.

4. Use according to claims 1 to 3, characterized gekennzeich¬ net that one uses the dyes in the form of their crystals, solutions or aqueous solutions unbound or bound to proteins, lipids or sugar.

5. Use according to claims 1 to 4, characterized gekennzeich¬ net that the dyes in colloidal dispersions gene with particle sizes in the range of less than or equal to

10 μm is used.

6. Use according to claims 1 to 5, characterized in that the dyes are used in medicine, in crop protection, in the textile, leather, hygiene, plastics, wood, paper or packaging material sector.

7. Use according to claims 1 to 5, characterized in that the dyes are used in inks, inks, paints, paints, stamps or printing inks.

8. inks or inks containing dyes selected from the group consisting of chlorophyll, flavonoids, retinoids, betaines, carotenoids or plant extracts containing these dyes, their natural or synthetic derivatives, or

5 mixtures of the dyes, the plant extracts containing the dye or their natural or synthetic derivatives.

9. Varnishes containing dyes selected from the group chlorophyll, flavonoids, retinoids, betaiains, carotenoids or plant extracts containing these dyes, their natural or synthetic derivatives, or mixtures of the dyes, the dye-containing plant extracts or their natural or synthetic derivatives. 5

10. Paints containing dyes selected from the group consisting of chlorophyll, flavonoids, retinoids, betaines, carotenoids or plant extracts containing these dyes, their natural or synthetic derivatives, or mixtures of the dyes, the dye-containing plant extracts or their natural or synthetic derivatives .

11. Use according to claims 1 to 7, characterized in that the dyes are used in clear coats.

12. Use according to claims 1 to 7, characterized gekennzeich¬ net that one uses the dyes for coloring Dispersionsfar¬ ben.

30

13. Use according to claims 1 to 7, characterized gekennzeich¬ net that the dyes are used as inks or inks.

35 14. Use according to claims 1 to 7, characterized gekennzeich¬ net that one stains labels or packaging materials of perishable products.

40

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