DED0014895MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Registration date: April 22, 1953 Bekanmtgemaeht on August 2, 1956

GERMAN PATENT OFFICE

It is known that the incorporation of pigments obtained in the aqueous phase in paints or varnishes containing organic solvents, presents certain difficulties. When drying aqueous pigment suspensions or when incorporating aqueous ones In almost all cases, suspensions in an organic medium lead to agglomeration of the pigment particles instead of. The size of each particle

ίο is not changed here; the single ones However, particles agglomerate to form larger clumps and are not evenly distributed in the Paints. A similar phenomenon occurs when processing carbon black. Soot is also known Difficult to distribute evenly in water or organic solvents. The single ones Rather, soot particles form coherent chains.

It is therefore difficult to obtain varnishes or paints in which the pigment or Soot particles are present in such a fine and even distribution that a completely grain-free and an even coat of paint is created. In order to overcome these difficulties, one usually grinds With the help of ball mills the finished pigmented coating material. Such a grinding often takes days and requires a considerable amount of work. Another way to get a fine one To achieve distribution of the pigments consists in the production of the so-called chips. Here the pigment is so together with the binder and optionally with plasticizers processed between friction rollers for a long time until an even distribution is obtained. the Chips usually contain the pigment in a higher concentration than is required for the finished paint.

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that is. In technology, they are added to colorless varnishes in order to give them the desired coloring give. Although the pigment is very evenly distributed in the usual chips, Their manufacture may require a long time and considerable effort.

It has now surprisingly been found

that there are pigments or finely divided fillers, which at. Manufacturing process or in a post-treatment occur in water-damp form, to particularly deep colors and lacquer-technically valuable ones Allow masses to be processed if they are used in the form of an aqueous dispersion. It has been shown that the pigments or fillers from the aqueous phase easily 'and almost quantitatively on the film formers present as a dispersion, e.g. B. high polymers, such as nitrocellulose, fail. The other paint raw materials are advantageous before the precipitation

ao dispersion added: According to one embodiment, of the process can be an aqueous dispersion of the pigments with the aid of a high-speed stirrer in one produced a considerable excess of water and then the remaining raw materials for lacquer and the film-forming agent added to the dispersion. In the case of collodion wool, for example, one can initially Add softener and dispersant and then water-dampened collodion wool.

These substances fall out in a very finely divided form on the collodion wool, which is placed on suction cups or can be separated from the bulk of the water by centrifugation. This process can be easily carried out in such a way that the water running off does not contain any pigment.

The dyed collodion wool thrown off or otherwise separated from the excess water is now subjected to mechanical processing, for example in a kneading machine, wherein further amounts of water leak out. If small amounts of a solvent are used during kneading to, then the dehydration is continued, and a celluloid-like modeling clay is obtained, which are rolled out on a friction roller in a few minutes into thin foils or sheets which the pigments in may be unusual

<■ 'fine distribution included. Especially with that Difficult to distribute soot, the advantages of the process stand out conspicuously in the high quality of the paints made with such chips. In general, the advantage is the possibility of

; to use water-moist pigments in their Production usually incurred in highly dispersed form, but one due to the drying process Experience coarsening of the particles.

It is known that nitrocellulose from aqueous dispersions plasticizers, which have gelatinization capacity, absorbs and can be dehydrated by kneading. Man makes extensive use of this in the manufacture of smokeless powder by

;. one treats gun cotton in an aqueous suspension with nitroglycerin or dinitrodiglycol. From this known process, however, it could not be concluded that in a Such "absorption" of the gelatinizing agent onto the fiber of the nitrocellulose also applies to the pigments be completely and evenly distributed. Furthermore, it was not foreseeable that this would lead to special Technical lacquer effects can be achieved in a special depth of color and high gloss of the with such masses produced paints exist. Finally, the rolling time is significantly reduced to be rated as a valuable technical effect.

The application of the method is not limited to collodion wool, but to others Film formers, especially high polymers, transferable, e.g. B. polyvinyl butyraldehyde acetals, polyvinyl acetaldehyde acetals, Polyvinyl acetate, also in the form of aqueous dispersion, polymethacrylates and soluble copolymers of vinyl chloride, this also in the form of the aqueous dispersion, such as that formed in emulsion polymerization.

It is known, a suspension of a finely divided pigment with an alkaline solution of a To mix polyvinyl ester. This mixture is then precipitated by adding acids and further processed in the usual way by kneading. In contrast to this, according to the invention, no Solution, but an aqueous suspension of a Höchpolymer can be used. The advantage of the The method according to the invention is that no solvents are used after either escape the procedure or in particular Recovery devices must be collected. Furthermore, in the invention Process for distributing the dyes in the binder does not require long and costly rolling, kneading or the like.

In order to achieve optimal effects, it is advantageous to disperse the pigments in water before mixing them with the other constituents of the mixture or to convert them to a state which facilitates their dispersion. While this is the case with many aqueous pastes of pigments resulting from precipitation processes, e.g. B. Berlinerblau, is possible without special aids, because of its hydrophobic nature, carbon black requires the use of wetting agents, emulsifiers and the like. Similar effects can also be achieved by treating the carbon black with water under pressure or by treating it with steam. Of course, for example, oxidizing agent or basic substances to delay the lying generally below 4 p _H value of the carbon blacks according to the basic range may be added with water under pressure wetting agents and other auxiliaries in the treatment of the carbon black.

example 1

An approach to the production of 40 kg of black chips

for nitro lacquers

14.4 kg of carbon black (trademark FWi) in 100! Of water,

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the o, 5 kg of a Fettalkoholsulfonats are added, heated for 5 hours with stirring to 140 ^0th

The aqueous carbon black dispersion obtained is pressed into a stirrer with a useful capacity of 500 l S which has 200 liters of cold water.

'' The agitator is charged with 34.6 kg of water-moist collodion wool of low viscosity (corresponding to about 23 kg dry N C) and homogenize the mixture by 10 minutes intensive stirring.

9.6 kg of dibutyl phthalate and 0.72 kg of toluene bisguanide (trade name Vulkacit 100). After brief, vigorous stirring, the mixture is allowed to run off into a centrifuge and throw off the water.

The resulting centrifugal cake is processed in a tiltable kneading machine and that here escaping water can be removed by tilting the machine. Continue kneading until none More water escapes, and brings the now guimmi-like soft product to about 60 ° warm roller mill.

Here other small amounts of water run off and the mass forms within a few minutes a rolled rind, which can be peeled off in the form of thin sheets after the rollers are narrowed. In In the cold, the product is relatively brittle and can easily be broken into flakes (chips) will.

These chips dissolve in the solvents and solvent mixtures suitable for collodion wool with deep black color. The solutions are particularly effective when poured onto glass smooth, deep black layers. The chips are used in a known manner to produce black Nitro and combination lacquers are used.

Example 2

for 10 kg of a nitiOcellulose-free rolling wet
for synthetic resin paints with a carbon black content of 35% 100 l of water are intimately mixed with 4.825 kg of a copolymer made from 80 parts of vinyl chloride and 20 parts of vinyl isobutyl ether under the name "Vinoflex MP 400" in a rapidly running, open stirrer.

To do this, you add so much of an aqueous carbon black paste, than 3.4 kg of dry soot.

After the two solid substances have been homogenized in water, a solution of 1.5 kg of Uresin B, a polycondensation product of butyl carbamate and formaldehyde and 0.175 g of paraphenylenediamine in 1.5 kg of methyl alcohol, is added. After a few minutes, the aqueous dispersion becomes more viscous and foamy. The mixture is stirred for 10 minutes and then heated to 80 to 90 ^° . The dispersion coagulates and the water can be separated on a suction filter. Bringing the coagulate in a 80 to 90 ⁰ heated kneading machine and rolls. then at a rolling temperature of 60 to 65 ⁰ . After the roller has cooled to about 20 °, the rolled sheet can be easily peeled off and shredded. The chips obtained dissolve in esters, ketones and mixtures of these with aromatic hydrocarbons. The solutions are preferably used for coloring synthetic resin paints, e.g. B. those that are used to paint bicycles and cars. The paintwork can be baked in up to 180 ° without affecting the gloss and depth of color.

Instead of carbon black, water-containing dispersions or pastes of inorganic or organic pigments can also be used. Very good 'results' were z. B. with pigments such as Berlin blue, cadmium sulfide, lead chromate, iron oxides, and organic pigments from the group of indanthrene dyes. In the same way, finely divided metal oxides of groups II to IV of the Periodic Table, in particular aluminum oxide, zinc oxide, silicon dioxide, titanium dioxide, can also be used according to the invention. Such white or transparent oxides, especially when they are thermally in the gas phase, eg. B. by the decomposition of volatile compounds such as SiCl ₄ , AlCl ₃ , etc., are obtained to achieve special paint effects such. B. matting or sedimentation delay, often desirable.

go B eis ρ ie I 3

Blue nitro chips

9 kg of Prussian blue are carried in the form of a 20% aqueous paste, as used in manufacture is obtained, in 80 kg of water with stirring. This blue colloidal solution is mixed in vigorous stirring with an 'about 10% mushy aqueous dispersion of 36 kg collodion wool of medium viscosity and leaves the lively agitated mixture run 15 kg of dibutyl phthalate in a thin stream. Dehydrated after 10 minutes using a centrifuge, the intensely blue colored pulp is brought into an internal kneader and removes most of the still adhering water.

The now already celluloid-like mass is about with a friction roller heated to 60 ° C Worked for 5 minutes and then rolled out into thin sheets.

By dissolving in butyl acetate and other solvents for collodion wool, smooth viscous solutions are obtained, which when poured onto glass result in completely transparent, strongly colored layers.

B is ρ ie 1 4 " ⁵

Chrome yellow with polyvinyl acetate as a binder

25 parts of lead chromate as a water-moist paste are mixed with 60 parts of a polyvinyl butyraldehyde acetal also in water-moist form, as it is, for. B. according to the method of the German patent specification 891 745, Example 4, with the addition of 15 parts of "Uresin B" (see Example 2) in a vigorous agitator, if necessary with further addition of water, mixed intensively. Centrifuge after 15 minutes, bring the

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Spin material into a kneading machine and then onto the friction roller. The work-up too Chips takes place as in example i.

It has proven to be particularly advantageous instead of the solid, powdery polymers or copolymers, the aqueous dispersions obtained in the emulsion polymerization to use their mixtures with carbon black or other pigments by known precipitants

ίο can be separated quantitatively.

Claims (2)

Patent claims: I. Process for the production of pigmented rolling compounds for paint purposes by adding from aqueous pigment or filler pulps to film formers distributed in water, in particular High polymers and subsequent kneading and rolling of the pigment film-forming mixture, characterized in that one uses aqueous pigment or filler pulps, especially aqueous Carbon black dispersions, based on aqueous dispersions of film formers, especially of high polymers or on emulsions of these film formers, as they arise during emulsion polymerization, precipitates. 2. The method according to claim 1 to 3, characterized in that that the dispersions of high polymers with pigments prior to coagulation, the remaining paint raw materials, z. B. dispersants and gelling agent. Considered publications:
French patent specification No. 1023925. 60S 577/463 7. 56