NO845103L - PROCEDURE FOR PAINTING WITH POWDER-SHAPED COLORS AND CONNECTION FOR EXECUTION OF THE PROCEDURE - Google Patents

Description

The present invention relates to a method for dyeing where the substrate to be dyed is brought into contact with a bath to which is added a powdered dye and a powder of an inorganic material that is insoluble in the bath, and the distinctive feature of the method according to the invention is that the material is chemically inert to the dye, it does not absorb, does not give a colored insoluble combination with the dye and is very finely particulate with the same degree of fineness as the dye.

The invention also relates to a means for carrying out the aforementioned method, and the peculiarity of the means is that it comprises an intimate mixture of 5 to 98% by weight of the dry dye and 95 to 2% of the inorganic material, the two components being particles with size 1 to 50 micrometers.

These and other features of the invention appear in the patent claims.

The invention is applicable for dyeing various materials, especially textile fibres, cellulose webs, polymers, keratin-containing materials and others.

Although dyeing is an old technique, it entails difficulties and uncertainties that often occur with the various dyes, especially when these are used in powder form. The present invention remedies irregularities in dyeing regardless of the dye used and is particularly useful with natural dyes.

The use of vegetable dyes is known and has

been carried out since ancient times. Dyeing is carried out by bringing the material to be dyed into contact with an aqueous suspension of various parts of the plants that are rich in the dye. However, the results are not reproducible due to variations in the content and quality of the dye from one batch of plants to another. Furthermore, the heterogeneity of the bath leads to irregularities from the dye to the treated material.

Concentrated vegetable extracts in liquid form, in the form of lumps, as crystallized powders or as atomized powders, for dyeing textiles, leather or printing ink, only provide a reproducible dyeing in operations that use large quantities of the dyes and materials to be dyed.

However, due to the non-toxic nature of most natural dyes, as well as the very reasonable price of some of them, certain dyes still have numerous uses. They are used within the food and pharmaceutical industry, e.g. for coloring beverages, oils, dairy products, confectionery, biscuits or ice cream. These extracts, however, even if they are highly concentrated, usually undergo more or less marked degradation after storage for several months. It is also noted that the colors that are possible to achieve are limited to yellow, orange, red, green and brown.

With regard to the special application of vegetable color extracts in capillary dyeing, this is simple, but the obtained coloring is weak and the preservation of the extracts is dependent on chance.

Certain mixtures for coloring hair comprise a dry vegetable color extract, a plant color powder, or the dye itself as a powder, mixed with substances such as sugar, polyols, inorganic or organic salts, or powders of extracted vegetable materials. At the time, the combined ingredients are mixed with warm milk or with warm water and applied to the hair to achieve toning. These preparation types are difficult to use, because they form a very thick paste or cream. They require large quantities of dyes and mechanical devices for the preparations intended for hair dyeing.

There are also certain mixtures of the powder of vegetable dyes, ready for use in the form of ointments by adding water, for coloring the hair. These products entail difficulties in use which are linked to the formation of the ointments. In general, the coloring achieved is weak and the application time is long.

Certain dyes used in paints, coatings, varnishes, printing inks or plastic materials are available in the form of pigments or so-called color varnishes. The dye is absorbed by an insoluble powder or is combined with this in the form of a metal complex. This is then made insoluble and is not released when the pigment or color varnish is diluted with water. In the applications indicated above, this product is in dispersion with a medium containing a binder such as e.g. a resin, rubber or synthetic polymer. When this dispersion is applied to a substrate, the dye does not react with it. In other words, it is not a question of coloring the substrate with the dye.

Although dyeing in general can give rise to difficulties, dyeing using natural vegetable dyes is particularly difficult. This technique has disadvantages due to difficulties in implementation, lack of reproducibility, generally too weak intensity of the staining and difficulties in preserving the dye preparation.

The present invention constitutes a significant advance

in the dyeing technique in that it allows the achievement of very stable dye preparations that can be easily applied for dyeing all types of materials on a small or large scale. The invention also makes it possible to prepare mixtures with any desired concentration which are useful for achieving lighter tints as well as intense colourings. The mixtures according to the invention are characterized by a very good stability under normal storage conditions, especially at normal temperature - in the dark in a closed container without special precautions. These products are insensitive to moisture and do not require the addition of a preservative. A vegetable extract ensures its own preservation more effectively than a preservative in some cases.

In the invention, one or more dyes are introduced in a solid state into a dye bath and this bath is brought into contact with a substrate to be dyed, as the dyes are used in the form of fine particles, intimately mixed with one or more solid inorganic materials that are insoluble in dye- the medium, as the fine particles are chemically inert towards the dye and do not absorb this and are used in the form of fine particles of the same order of magnitude as the dye.

The inorganic material can be introduced into the dye bath from the introduction of the dye, after which the bath is carefully mixed. In the meantime, it is preferred to use a very intimate mixture of these two substances prepared in advance.

The inert nature of the inorganic compound towards the dye means that when placed in the solvent medium these products do not form any insoluble combination of the dye. In other words, with mixtures according to the invention diluted with the solvent, the unchanged particles of the inorganic substance and the particles or solution of the dye are present in the liquid. This is a fundamental difference between mixtures according to the invention and the previously known pigments, which comprise particles formed by an inorganic compound which is combined with the dye, these particles being insoluble in the solvent. The inorganic compound should also not give rise to any reaction involving oxidation, reduction or release of ions with the dyes used.

In the case of a natural dye, the powder used in accordance with the invention preferably comprises an extract prepared in a manner known per se from one or more parts of a plant containing the dye. The preferred form of the invention uses a powder of the vegetable coloring material itself. However, the effect of the addition of the inorganic compound allows good color products to be produced, even with the powder obtained by grinding roots, leaves, shoots, fruits, husks, grains, etc. of a color-bearing plant. Due to the fineness of the paint and the presence of the inorganic compound, the above disadvantages mentioned in connection with the previous methods no longer occur.

When carrying out the invention, the fineness of the powders used should be such that the particles only have a size of approximately 1 to 50 micrometers and preferably from 2 to 30 micrometers. Particularly favorable results are obtained when the dye particles have a size of between 5 and 10 micrometers and the particles in the inorganic substance from 2 to 16 micrometers.

The first criterion in the selection of the inorganic compound, as indicated above, is not to form any combination which is insoluble in the solvent, with the desired dye. The other two criteria are preferably based on an apparent density of not more than 300 g/cm 3 or better in the range from 50 to 200 g/cm 3 for the non-compacted powder. The specific surface should be between 4 and 110 m o/g and preferably below 8 m 2/g.

As a non-limiting example, oxides of zinc, titanium, silicon or Al, natural silicates such as kaolin, bentolite or talc, certain carbonates, phosphates or fluorides, such as e.g. of calcium or magnesium, complex aluminum silicates such as mica. Apart from natural silicon oxides, synthetic microcrystalline silicon oxides can also be used, provided that these are hydrophilic or rendered hydrophobic by chemical treatment.

It is noted that an inorganic compound which with certain dyes gives a pigment and consequently does not form any part of the invention in connection with this dye, can, if desired, be used within the scope of the invention with other dyes, with which it does not give any insoluble pigment.

This is e.g. the case of hydrated aluminum oxides which with extract of scrub root or with alizarin form a color varnish that lies outside the scope of the invention. Conversely, the same hydrated alumina can form a mixture in accordance with the invention with an extract of indigo leaves or methyl violet.

The relative proportions of dye and inorganic compound can vary within wide limits, in particular from 5 to 98% of one to the other in the mixture. In practice, the preferred amount is about 10 to 80% by weight.

It can be seen that mixtures in accordance with the invention can include one or more dyes and one or more of the inorganic compounds mentioned above.

The dyes produced in the form of mixtures in accordance with the invention are particularly stable when stored for long periods, of more than 18 months in most cases, even when the content of dye element is low. However, they are easily dispersed or transferred easily in solution in a uniform manner, without forming agglomerates, lumps or granules,

in the solvent that is usually used to carry out the actual dyeing, depending on the material to be dyed. This can be done by simple stirring which does not require the use of any special equipment and also both at normal temperature as well as at temperatures between 10°C and the boiling point of the solvent, depending on the process required by the nature of the material to be dyed. The solvent can be water, another solvent, a mixture of solvents, or even a solution mixed from different chemical substances usually used for dyeing.

Due to the dye preparation produced according to the invention, the dyeing of fibers or other materials can take place in a completely homogeneous manner. It is very simple and reproducibility of the toning is facilitated, due to the fact that the invention facilitates the handling of the very small quantities of color substances in an accurate manner, without complicated or intricate weighing equipment. It is actually sufficient to use a mixture according to the invention with a low dye content, due to the fact that the amount of coloring material is low for a relatively large volume. In addition, due to the mixtures according to the invention, the dye molecules must react in a uniform manner with metal salts, oxidizing substances or other reaction components present in the dye solution. A material dyed on a

.homogeneous manner in every respect is thus achieved. Consequently

the user can easily achieve several tints with the same dye, without varying the dye procedure for the same material to be dyed. The intensity of the coloring is determined by the manufacturer of the color mixture. Furthermore, dyes that can be used can be mixed without difficulty, when there is no reactivity between the dyes used,

before the actual dyeing. The different dyes are then evenly distributed over the material to be dyed and the user can achieve highly varied shades.

Another advantage of the method according to the invention is that the time required to achieve coloring of a given material is reduced considerably. For example, in the case of wool, dyeings using vegetable dyes which normally require two days can be carried out in only 2 to 3 hours.

The method according to the invention is suitable for dyeing various substrates with the help of inorganic or organic dyes, especially materials of animal origin, especially Tyrian purple, koschineal red or guanine, and numerous synthetic dyes, such as e.g. the azoids, phthalocyanines, oxazines, thiazines, anthraquinones, benzidines, xanthenes and others. The invention can thus be used for dyeing with different dyes for varnishes, plastic material, textile, paper, wood, leather, printing ink, pharmaceutical preparations, food preparations or cosmetic products.

The invention is particularly useful for dyeing using natural dyes. This can be used for a large number of color plants and allows the achievement of a large range of basic tones, especially in yellow, brown, organge, blue, red, black and, by mixing, intermediate tones. A table of several plants that can be used to obtain color extracts that are used in the process in accordance with the invention is given below.

The following examples illustrate the invention.

EXAMPLE 1

Dyeing of paper

To 100 parts of a suspension of 2.5 parts of bisulphite-treated wood pulp, bleached in water, is added 0.08 parts of crystalline aluminum sulphate previously dissolved in 0.8 parts of water. 0.25 g of a mixture in accordance with the invention is added to this preparation while stirring

10% Campeachy extract,

85% talcum powder with particle size 2-5 micrometers, 5% microcrystalline silica, 2-4 micrometers.

After 15 minutes, the mixture is filtered through a cloth and dried. The paper sheet thus formed is dyed in the pulp to

give a good uniform violet color and the dyeing resists water very well.

If the simple color extracts are used, a paper web is produced with a deep blue-violet color mottled in an irregular manner with darker violet spots.

EXAMPLE 2

Dyeing of paper

The operations are the same as in example 1, but the color mixture is replaced by the following:

4% Campeachy extract,

6% Sophora Japonica extract,

85% talc,

5% microcrystalline silica.

The resulting sheet of paper is uniformly green.

EXAMPLE_3_

Dyeing of fur

For a washed and tanned sheepskin, a solution of ferroacetate is applied to the ends of the hair using a soft brush.

After drying, apply the following solution:

100 parts lime water (water saturated with calcium hydroxide),

2 parts of double sulphate of aluminum and

ammonium,

2 parts iron sulfate,

10 parts, added at the time of use, of a mixture in accordance with the invention, which consists of: 27% kaloin in powder form with a particle size of 3 to 10 micrometres,

3% microcrystalline silica,

25% Campeachy extract,

45% Pernambuco wood extract.

The mixture comprising this solution, also applied with a brush, serves to color the fur uniformly brown if it is completely covered. When applied pointwise, an imitation of the fur of certain animals is achieved.

This process has also been used with other types of leather or fur.

When it is desired to achieve a similar dyeing of fur by means of the previously known method using a plant powder, difficulties arise. The same applies if it is desired to use a vegetable extract that has not been prepared in accordance with the invention. The dye solution is actually not homogeneous, as it forms a suspension with agglomerates of particles with the dye, due to poor solubilization, above 20°C. The coloring of the coats is irregular and unusable or at least requires very long and vigorous stirring.

EXAMPLE_4_

Dyeing of woolen yarn

100 parts of wool in cloves are treated in a solution containing: 10 parts of the double sulphate of aluminium

and potassium,

3 parts potassium hydrogen tartrate, and 3000 parts water, for one hour at 90°C. After cooling, cleaning and draining, dyeing is carried out in: 3,000 parts of water to which 10 parts of a mixture as follows has been added:

produced in accordance with the invention:

70 parts of an extract of Genista tinctoria,

27 parts talc,

3 parts microcrystalline silica.

After 45 minutes at 90°C, the yarn is dyed with fresh cintron color in a uniform and permanent way.

When plants or plant powders are used, two days are necessary for complete coloring and this requires the following laborious method of operation: 500 parts of yellow leaves of Genista Tinktoaria are ground, crushed overnight in 3000 parts of non-calcareous water and then brought to a boil for 45 minutes. After cooling, the solution is filtered through fine cloth and the vegetable remains are introduced into a textile bag which is then placed in the dye bath. The wool fibers, stained as before and still moist, are then placed in this solution and the whole mixture is brought up to 90°C for 45 minutes. After drying, the yarns are colored lemon yellow. However, if the dye solution is not suitably filtered, the dyeing is not uniform and after cooling several cleanings are necessary to completely remove the vegetable powder.

EXAMPLE 5

Capillary staining

Using the method described in French patent application 8312458, hair is first treated with a preparation (A) containing: 3% nonylphenol combined with 10 mol of ethylene oxide,

0.8% diethylanolamide in coconut oil,

3% aluminum lactate,

sufficient percentage of ionized water acidified to pH 3.5 with lactic acid.

After 5 minutes of this treatment, the hair is cleaned and the following preparation (B) is then applied: 3.5 parts nonylphenol combined with 6 moles of ethylene oxide,

1 part sorbitan monooleate,

1.5 parts isopropanol,

13

2 parts stearic acid,

0.3 parts sodium hydroxide,

1 part sodium alginate,

to which are added 3 parts of a mixture in accordance with the invention containing:

30* kaolin,; 3% microcrystalline silica,; 30* extract from red sandalwood,

20% Roucou extract,

17% Campeachy extract.

Applied for 30 minutes on fair hair, this mixture produces a light tan with deep tan areas after a simple rinse and dry.

The use of vegetable extracts alone leads to a solution (B) which is not homogeneous. The dyes agglomerate into lumps in the preparation and the coloring is consequently not uniform.

The direct use of the powder of these vegetables as such leads to a solution (B) which is difficult to apply, forms a cream and gives only very pale colorings which are non-homogeneous both with regard to coloring and distribution.

Furthermore, abundant rinsing of the hair is necessary to remove the vegetable powders.

EXAMPLE 6

Color varnish for wood

A mixture consisting of the following is prepared:

14 parts resin rubber,

7 parts rosin,

3 parts turpentine,

76 parts ethyl alcohol

1.6 parts of a mixture according to the invention are then added, containing: 50 parts of the dye CI Acid Brown 357, 25 parts of talcum powder of particle size

2-5 micrometers,

25 parts micronized kaolin.

When applied with a brush on light wood, a good brown color is achieved, without marbling or stains.

The direct use of the same dye leads to a marbled and mottled colouring.

EXAMPLE_7

Printing ink

In 85 parts of a mixture of equal parts by weight of distilled water and ethyl alcohol, 15 parts of a low molecular weight polyamide 6 resin are dissolved. 0.5 parts of a mixture according to the invention is then added, comprising: 60 parts of a yellow dye comprising

a metallic complex of chromium (CI

Acid Yellow 121),

10 parts microcrystalline silica,

2-4 micrometers,

30 parts kaolin 5-8 micrometers.

When applied with a stencil to a polyethylene container followed by drying, decorative motifs of a clear yellow color free of marbling are obtained.

EXAMPLE_8

In a textile dyeing machine used for dyeing polyesters by means of the process known as high-temperature bath circulation, a spool of textured polyester jersey is introduced in a bath ratio of 1 to 10.

For 100 parts of polyester, 1.5 parts of a preparation according to the invention are prepared in the form of a paste with a small fraction of the dye bath, comprising:

30% of a red dye with formula:

The paste-like product is introduced into the dye bath in circulation at 30°C. The apparatus is then closed and the temperature is brought to 120°C for 1 hour. After cooling and washing, a textile fabric uniformly colored to a good uniform red color is obtained.

Using the red dye as such a powder is difficult, due to the fact that it forms an unfortunate paste with the dye bath and stains the textile material.

EXAMPLE 9

100 parts of silk cloth are treated for one hour at 50°C in a bath composed of:

300 parts water,

10 parts of the double sulfate salt of aluminum and

potassium, and

3 parts potassium hydrogen tartrate.

After cooling, rinsing and draining, the dyeing is carried out in 2000 parts of water to which 10 parts of the following mixture are added:

50 parts cochineal extract,

40 parts kaolin, and

10 parts microcrystalline silica.

The temperature is maintained at 150°C for one hour and then the dye bath is cooled slowly. When it has assumed normal temperature, the silk fabric is removed, rinsed and dried. It has an intense carmine color that is brilliant and completely uniform.

Claims (12)

1. Dyeing process where the substrate to be dyed is brought into contact with a bath to which is added a powdered dye and a powder of an inorganic material that is insoluble in the bath, characterized in that this material is chemically inert to the dye, does not absorb it and does not give a colored insoluble combination with it and is very fine-grained with the same order of magnitude of fineness as the dye. 2. Method as stated in claim 1, characterized in that the color powder and the powder of the inorganic material are particles with approximately 1 to 10 micrometers and preferably from 2 to 30 micrometers. 3. Method as stated in claim 1 or 2, characterized in that the inorganic material is a powder with a particle size of from 2 to 16 micrometres. 4. Method as stated in claims 1-3, characterized in that the particles of the dye have a size of between 5 and 10 micrometres. eh 5. Method as stated in claims 1-4, characterized in that the powder of the inorganic material has an apparent density of not more than 300 g/dm 3 and preferably between 50 and 200 g/dm 3 in a non-compacted state. 6. Method as stated in claims 1-5, characterized in that the powder of the inorganic material has a specific surface of between 4 and 110 m 2 /g and preferably below 8 m<2>/g. 7. Method as stated in claims 1-6, characterized in that the inorganic material is an oxide or silicate of a metal, especially zinc, titanium or silicon, aluminum, especially a natural silicate of the kaolin, bentonite or talc type and silica. 8. Method as stated in claims 1-6, characterized in that the inorganic compound is a microcrystalline silica which is hydrophilic or rendered hydrophobic. 9. Method as stated in claims 1-8, characterized in that the dye is an organic synthetic or animal dye. 10. Method as stated in claims 1-9, characterized in that the dye is an extract of a dye-bearing plant. 11. Means for carrying out the method specified in claims 1-10, characterized in that it comprises an intimate mixture of 5 to 98% by weight of dry dye and 95 to 2% by weight of inorganic material, in that the two components are particles with a size of 1 to 50 micrometers. 12. Agent as stated in claim 11, characterized in that it only comprises 10 to 80% of the dry dye as a powder with particles from 2 to 30 micrometers respectively 90 to 20% of the inorganic substance in the form of particles with a size of 2 to 30 micrometer.