DE1966119A1 - Process for making synthetic pearlescent pigments - Google Patents

Description

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DIPL.ING. H. LEINWEBER »if £ ..ing. H.ZIMBIERMAIiPi

Z-open *

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«• fern (HIt) SMIfW

PoHtch ^ de-KontO:

February 26, 1971

PQS 24 §49 ASAHI KASEI KOGIO KABÜSH1KI IAISIA, Osaka. / Japan

Method of making synthetic nacreous

Pigments

Application for divorce from patent. ,,,,. (Patent application

P 19 65 in 4-43)

The invention "relates to a method of making synthetic pearlescent pigments in the form of thin platelets Crystals with a smooth surface and uniform shape and size from at least one of the compounds triazine or triazine derivatives. The peculiarity of this procedure is that one the triazine or its derivatives from a solution in the presence of a Surfactant crystallized, The invention relates to furthermore synthetic mother-of-pearl-like pigment particles from the on these Way obtained thin platelet-shaped crystals, as well as synthetic ones pearlescent pigments for Sohmuck purposes, which contain these Pigijentteilchen: contain.

Pigments with a pearlescent luster have been known for a long time. Synthetic pearlescent pigments were made, for example, from table scales of herrings, sprats, sardines, etc., as well as inorganic compounds such as lead carbide, wisai chloride, lead phos-

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phat etc. manufactured. The fish scales are not expensive, but inevitably contain a large amount of impurities. They therefore have the disadvantage that the product when used as a perlessem, as a result of the Presence of impurities during storage yellowish or reddish discoloration. If the fish scales are also insufficient cleaned, they have an unpleasant odor at. Fish scales are therefore not suitable starting materials for modern industry, in which a mass'? ». production of standardized products is a prerequisite.

Numerous studies have therefore been carried out in order to produce pigments with a good pearlescent luster, but without the disadvantage of fisehicules. The ones used as replacements. Compounds lead carbonate, bismuth chloride, lead phosphate etc. are, however, highly toxic and have a low resistance to chemicals. Therefore, they are not suitable for face painting, synthetishe resins for toys, containers for '· Food and Beverage and the like. j

In the context of the invention, cheap organic '■ compounds with pearlescent luster on the basis of triazole and its derivatives have now been found, which meet the requirements for a'

Pearlescent substances are sufficient. j '

According to the invention, a synthetic mother-of-pearl-j Produce a pigment which is completely harmless to the human organism and which is excellent Neten pearlescent.

The invention provides a method of making voi new synthetic pearlescent pigment articles which platelet-shaped crystals from at least one of the

■ · '109830/2 077

Compounds triazine or its derivatives are obtained.

The invention will now be further explained with reference to the following description. Commercially available triazine or triazine derivatives, for example 2,4,6-triamine-s-triazine (monomeric melamine), is dissolved in hot water and the resulting solution is cooled relatively quickly with or without the addition of a surface-active agent, with stirring, or poured into cold water, whereby thin platelet-shaped crystals of the compound precipitate. In this case one can use thin platelet ^; obtain shaped crystals of relatively uniform shape by cooling the solution relatively slowly until the start of crystallization and rapidly cooling the solution with stirring after the start of crystallization; crystals precipitate quickly, although the shape and size of the crystals may vary depending on the crystallization process. The crystals thus obtained can in some cases be mixed with an aqueous face lotion, with soap or a milky lotion. Generally, however, these crystals are dispersed in η-hexane, butyl alcohol or the like, which are used as a dispersion medium for ordinary pigments. If necessary, they can be mixed with other additives, such as, for example, nitrocellulose and the like, it being possible to obtain a pigment with an elegant pearlescent luster. Cosmetics, such as lipsticks, flanic liquid, etc., tableware made of various

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synthetic resins such as polystyrene, methacrylate resin, etc., Cotton, various chemical and synthetic fibers, natural and synthetic leathers, paper, glass and · The like, which are mixed with the above-mentioned pearlescent pigments of triazine or triazine derivatives or coated, have an elegant and fine pearlescent luster. The above pigments are very persistent to heat and chemicals and also have good weather resistance even after being mixed with various other materials or applied as a coating became.

Under "triazine" and "triazine derivatives" are in the present Connection to understand compounds of the following general formulas I and II, which both have an s-triazine ring as well as an as-triazine ring: R

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(D "ö. Dl)

In the above formulas, R has the meaning of hydrogen or hydroxyl, carboxyl, amino, "dimethylamine, Äthyleniaino, methyl, ethyl, propyl, butyl, phenyl or benzoyl. The desired pearlescent product with pearlescent luster can be obtained from these compounds by suitable choice of the crystallization region -. create conditions.

The above-mentioned triazine and its derivatives can in a simple V / eise by known reactions for the preparation of s-triazine rings and. as-triazine rings are obtained .

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BATH ORIGINAL

1 $ 68119

For example, 2,4,6-triamino-s-triazine can be obtained by heating Manufacture of Dyciandiamide in Liquid Ammonia; 2,4,6-Trihydroxy-s-triazine can be polymerized of cyanic acid. Furthermore, one can use 3-AmInO ^, 6-di— Easily prepare methyl-as-triazine by reacting diacetyl and aminoguanidine. Furthermore, 2,4,6-triamini-s-triazine is commercially available as a starting monomer for melamine resins available and is already being produced on an industrial scale. . . . .

The thin platelet-like crystals of triazine and triazine derivatives according to the invention, which can develop a pearlescent usually will have a length of up to 100 microns, a width of 3 to 40 microns and a thickness of 0 _F 05 to 3 microns. In "this case, it is most important that the crystals have a uniform shape and size and have a smooth crystal surface. Commercially available triazine or triazine derivatives are in the form of a powder or a shape and therefore have no such pearlescence. Even if these compounds are mentioned Uncrystallized under conventional crystallization conditions, they do not form crystals with pearlescent luster. For this reason, despite the high refractive indices, it was not possible to use triazine or triazine derivatives as starting materials for synthetic pearlescent pigments.

In the context of the invention, the crystallization conditions for triazine and triazine derivatives were investigated and it was found that crystals corresponding to the above requirements can be obtained by regulating the temperature change and the pH during crystallization and at the same time adding a surface-active agent to the crystallization · * Admits. . - 6 -

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The crystallization conditions can vary depending on the. the connections used as well as the shape, size and The strength of the desired crystals will vary. Furthermore, the shape of the crystals by suitable combination of the temperature difference, the cooling rate, the speed the pH changes as well as the type, amount and pulling time of the surfactant is affected. Although these conditions are specified in more detail in the following examples; are explained, the relationship between the crystallization conditions and the crystal shape is explained in more detail below: ,

If 2,4,6-triamino-s-triazine is crystallized from an aqueous solution containing a single anionic surface-active agent, LUIOX 100, the shape and strength of the precipitated crystals fluctuates largely with the cooling rate of the solution. For example, if a solution is cooled in the _; Over 60 .Minuten under Hühren of 5O ⁰ C to 30 C, one rectangular crystals obtained with a length of 20 microns, a width vo 10 microns and a thickness of _0.07; Micron. The solution is cooled over a period of 40 minutes under Hühreß of 50 ⁰ C to 3O ⁰ C, one rectangular crystals obtained with a length of 15 to 20 microns, a width of 3 to '■ 5 microns and a thickness of 0.08 Micron. If the cooling is carried out in the course of 10 minutes, Heine crystals with a length of 5 microns and a width of 2 mkron will fall! and a thickness of 0.2 microns. Therefore, the higher the ex "is cooling rate ', the greater and more sinct die'ge i-formed crystals, and the lower the gloss crystal. If one the other hand, cooling from 50 to 3O ⁰ C in the course

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of -180 minutes or even longer, one obtains. cylindrical, but not thin, platelet-shaped crystals.

A difference in pH fourth of the solution after adding of the surfactant and prior to the first precipitation of the microcrystals also causes a difference in the shape and strength of the crystals formed. Holds if the pH of the solution is, for example, 6.8 to 7.2, rectangular crystals with a thickness of 0.07 fall Micron off. At a pH of 5 to 6, rhombic or triangular crystals with a thickness of 0.1 are obtained Micron. At a pH value of 7.5 to 8.5 rectangular crystals are obtained with a length of 20 microns, - a width: 3 microns and a thickness of 0.1 microns. If you lead the If the solution crystallizes in a neutral state, a streamlined shape is obtained with the strongest ' Pearlescent luster in the solution. ι

LUNOX 100 is the most suitable surfactant to remove thin platy crystals of 2,4,6-tria- i to get mino-s-triasin. The amount of added top I Surface-active coat affects the strength of the precipitated crystals. With an added amount of 0.5 to 1.0 ..; Gev. '? I, for example, crystals with a strength are obtained. of 0.07 microns; with a larger amount you get some j

stronger crystals. . I.

The mechanism of the influence of a surface-active agent in the process of the present invention has not yet been clarified, but it is believed that the surface-active agent Agent causes or causes some change in the state of the solution, such as the physical "properties, ·

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density, diffusion, etc., so that certain favorable conditions for the formation of the crystal nuclei and the growth of the thin platelet-shaped microcrystals arise in the crystallization system. If, for example, 1 g of pure 2,4,6-triamino-s-triazine ^ dissolved in 100 ml of hot water at 9O ⁰ C and the resulting solution is cooled relatively rapidly with stirring at 10 ⁰ C, so .lediglich precipitated forms a part. Crystalline thin platelet-shaped crystals and few streamlined patterns appear in the solution. It is extremely difficult to separate only the thin platelet-shaped crystals from this crystallization solution; furthermore, the thin plate-like crystals obtained in this way do not have a uniform shape and dimensions. On the other hand to solve 1 g of 2,4,6-triamino-st-riazinetrione of relatively high purity, for example a purity of 95, in hot water at 9O ⁰ C and, after-cooling the solution to 50 C. 0.5 g of an anionic surface-active agent, LUNOX 100 (trade name) and the solution slowly cools with suitable control of the solution temperature, 0.45 g of thin platelet-shaped materials is obtained. Crystals of uniform rectangular shape 15 to 20 microns long, 3 to 5 microns wide and 0.08 microns thick. If the same experiment is carried out without the use of a surface-active agent, almost all of the precipitated crystals have a columnar structure.

The surfactant used in the invention not only serves to properly control crystal strength, i.e. regulating the direction of crystal growth, with the formation of thin platelet-shaped crystals, but rather

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also to regulate the uniform shape and size of the crystals, and at the same time prevents the adverse influence. of the impurities present, which cause crystallization impede.

Suitable as surface-active agents in the invention

way
For example, kaxionic surface-active agents such as amines and their salts, quaternary ammonium salts, pyridinium salts, picolinium salts, zelanium salts, belanium salts, amine / ormaldehyde condensation products and stearon-ghrom-III-chloride; anionic surface-active agents, such as alkyl sulfates, alkylbenzenesulfonates, alkylnephthalene sulfonates, naphthalene- | sulfonate-formaldehyde condensation products, alkyl phosphates, amidosulfonet and sulfosuccinate dialkyl esters; anphoionische surfactants, such as betaines (such as alkylbetaines), .SuIfqxylatverbindungen (eg ^{Hydroxyäthylimidazolinsulfo-;} nat), sulphonate and phosphate compounds, etc .; non-ionic surfactants, ie esters, ethers, alkylphenols, tension-type compounds non-ionizing enteric fatty acid ^; '(Lauric, palmitic, stearic, oleic acid) and sorbites as well as compounds of the Tv / e type (polyoxyethylene derivative of GorLi- j tanhydride).

The zv / ockfiiäßi amount of the superficial active agent used in the uri'iriaungsgralisssn 'crystallization can j o according to the type of the aviJton triazine; or deaacn ^; Derivatives achwsnJien. In general, however, nino t-feng "ranges from '1 bic 0.001 Gow. ^, Based on the weight C-.:i·, ^. Pij .i-ci ·!."; Λ Lörring, aua. Dao superficial means b: .rn eu der! »" LUaai ^ roit zu Bc ;; inn odor unpittolbar vor:; -] or h-vJa dorn Bciilnn:. ^For AU :: cboidunr; dv * · ^ uünnchtcit ICr-. r.b'-lLii Kiiijuifnbori

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will. In this case, it suffices to use the surface active agent dissolve or disperse in the liquid during crystallization.

The crystallization concentration of the triazine or triazine compounds can of course vary depending on the nature of the Connection fluctuate. However, the crystallization concentration is preferably 0.1 to 2 $ although these compounds have different solubility.

The thin platelet-shaped crystals thus obtained are suitably removed by, for example, filtering off, centrifuging off or the like separated. If the separated crystals are treated with an aqueous or alcoholic face lotion, If you mix a soap or milk lotion, you can get commercial valuable products with a streamlined pattern and achieve an elegant pearlescent luster. Furthermore, these crystals can be mixed with a dispersing medium for pigments, such as acetone, n-hexane, Butyl alcohol or the like, can be mixed and the resulting dispersion can be added together with the necessary additives and pasting, kneaded with the desired material or coated thereon and then dried.

The invention provides a method for using thin platelet-shaped crystals of triazine or its Derivatives as pearlescent pigment particles, and a composition containing these crystals. The invention also provides a process, according to which crystals of triazine or triazine derivatives with practically the same crystal length and -strength as well as a smooth surface and uniform shape can be produced in good yield by using a surface

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active gown to a solution of triazine or triazine derivatives admits.

These advantages can be summarized as follows:

(1) The compounds used as raw materials are cheap.

(2) The synthetic mother-of-pearl-like pigments produced according to the invention are chemically stable and extremely weatherproof.

(3) The thin plate-shaped manufactured according to the invention Crystals have a specific weight similar to that of conventional pigment masses compared to inorganic flakes, e.g. of lead carbonate, lead arsenate, etc., and therefore can be easily dispersed uniformly.

• (4) The crystals according to the invention can be in contrast to fish scales, always in a simple manner with a uniform shape and size manufacture and are therefore suitable for mass production.

(5) The crystals of the present invention can be used together with other pigments having pearlescent luster will.

(6) Thin, plate-like crystals with certain dimensions, uniform shape and smoother Crystal surfaces can be easily obtained using a surface active agent will; the sealing of crystallization

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is easy given the strength, shape and size of the
Crystals according to the invention can be largely changed at will, in contrast to naturally occurring products such as fish scales. Furthermore, there is no chemical reaction during the
Crystallization is required as with the inorganic synthetic flakes such as lead carbonate and the like.

The invention will now be explained further with the aid of the following examples. In the examples all relate
Parts and percentages are by weight, if nothing

other is indicated. ·

Example 1 :

10 g of white powdery 2,4,6-triamino-s-triazine; with a purity of $ 95.5 was dissolved by heating in 1 liter ^: distilled water. The solution was then cooled with stirring to 5O ⁰ C and at this temperature
0.5 g of an anionic surfactant _: LUNOX 100 (trade name) was added. Then the solution was: history cooled from about an hour slowly to 3O ⁰ G \ where thin flaky microcrystals in length! of less than 1 micron began to fail. At this point the stirring speed was greatly slowed down and
the liquid was slowly ^{cooled to 10 0} C, crystals with pearlescent, smooth surface, a length of. about 20 microns, about 10 microns wide and one
Thickness of about 0.07 microns began to fall out, in this j

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In the state that the reaction has continued for a long time _: with all the precipitated crystals uniformly having the above: dimensions ·· the reaction liquid is white; a strong streamlined cough. The crystals were filtered out from the reaction liquid and dried. The dried ones. Crystals were mixed with resins as they were, and the mixture obtained was press-molded to obtain synthetic resin molded articles having pearlescent luster.

Example 2

A solution was prepared by heating and dissolving 10 g of white powdery 6-aminO-s-triazine-2,4-diol with a purity of 97 »5 ^ in 1 liter of distilled water. This solution is referred to below as "Solution A". Separately, a liquid was prepared by adding 0.5 g of a cationic surfactant, ANSTEI 0-200 (trade name), to 4 liters of distilled water. This solution is hereinafter referred to as "liquid B". The solution A was poured all at once into the liquid B with stirring and the reaction mixture was slowly cooled ^{to 20 ° C. in the course of about one hour.} Microcrystals with a size of about 1 micron began to separate out. In this condition, the reaction was continued for an additional two hours, the reaction geaisch exhibiting a strong streamlined sexton. At this point, thin diamond-shaped crystal flakes about 15 microns in diameter and about 0.08 microns wide were deposited. The crystals thus formed were filtered off in a moist place

10: $ £ 3 & / Ζ077 BAD ORIGINAL

T9B611S

Subjected to flash evaporation to the reaction solution remove from the surface of the crystals and with methanol washed. The crystals thus obtained were then.mit different starting materials, - depending on the different Uses., Mixed, being excellent Pigments with pearlescent luster were obtained.

10 g of white powdery 2,4,6-trihydroxy-s-triazine with a purity of 95.070 was heated and dissolved in 1 liter of distilled water. After cooling the resulting solution to 50 C, 0 _? 5 g of an amphoionic surfactant Obanol D (trade name) was added to the solution and the Eeaktionsflüssigkeit was added over VQN about 1 hour at 2O ⁰ C cooled. In this state, the reaction was continued for an additional two hours, with pearlescent pearlescent crystals precipitating that were 15 to 20 microns long, 3 to 5 microns wide, and 0.08 microns thick. The crystals were filtered off and then completely dehydrated by flash evaporation, whereby thin plate-shaped crystals of 2,4,6-trihydroxy-s-triazine were obtained. 2 parts of the crystals thus obtained were mixed with 15 parts of beeswax, 10 parts of lanolin, 4 parts of castor oil, 4 parts of ceresin and 1 part of cosmetic aromas to produce a lipstick. The lipstick obtained in this way had a good pearlescent luster »

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2 .Q: TT

BATH ORIGINAL Example 4_

10 g of white powdery 2,4-diamino-6-phenyl-striazine with a weight of 95.5% were heated and dissolved in 1 liter of 0.1 μm aqueous ammonia. The resulting solution was stirred in a boiling water bath, the ammonia present in the solution being evaporated. Here, thin platelet-shaped microcrystals with a size of less than 1 micron fell out. The solution was filtered and the FiItrat was treated with 15 ml of a I ^ aqueous solution of a nonionic surfactant, IONAL 210 (trade name) was added and the resulting mixture was allowed to stand in a cold liaum at 5 ⁰ C. After about 10 hours, crystals 10 microns long, 5 to 10 microns wide, and 0.07 microns thick separated. The crystals were filtered off and completely dehydrated by flash evaporation, whereby thin plate-shaped crystals of 2,3-diamino-6-phenyl-s-triazine were obtained. 2 parts of the crystals thus obtained were mixed with 100 parts of polyvinyl chloride resin, 48 parts of diocthyl phthalate, 0.7 part of gadmium stearate and 0.5 part of barium stearate. The resulting mixture was kneaded on an open roll of 170 ⁰ C and the kneaded product was

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rolled out on a calender roll into a pearl film. For example £ iel_5

1 liter of a 0.5 ^ suspension of 4-amino-6-phenyl-s-triazindlol with a spray unit of 96.5 ^ was ebracht _fc in a boiling water bath .and brought into solution. Ethanol was added dropwise to the solution in an amount of 10 ml / min, whereby needle-shaped crystals less than 3 microns in size were precipitated. The solution was filtered off and 1 ml of a 1% anionic surfactant solution, Gafac HS-410 (trade name) was added to the filtrate and the reaction mixture was rapidly cooled to 5 G over 5 to 10 minutes with stirring. Thereafter, the reaction mixture was allowed to stand at 5 ° C. for about 1 hour, whereby a streamlined pattern was observed. At this point, the precipitated crystals were 25 to 30 microns long, 5 to 6 microns wide, and 0.08 microns thick. A microscopic comparison of these crystals with herring scales showed that the shape of these crystals was very similar to the herring soups. The herring scales, however, had uneven surface dimensions, while the crystals according to the invention were practically regular.

The above crystals were filtered off with ethanol washed and air-dried and then added using a dispersant, resins and the like e.Lner paste processed. The paste was made with a suitable Diluent diluted, being a fai.be with pearlescent was obtained.

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5 g of white powdery J-triazine with a purity of 97.5 ^ was in 1 liter dissolved in distilled Viasser. laugh complete dissolution the solution was cooled to 50 ° C. and then methanol in an amount of ml per minute and a 1 ^ solution of a katicmix surfactant, ANSTEX-C-200 (trade name), added in an amount of 5 ml per minute, whereby microcrystals began to fail. At this point the cooling and the addition of methanol and surfactant Medium interrupted and the reaction mixture slowly increased to 5 C over the course of about 1 hour cooled down. In doing so, rhomboid to square ones fell Crystals about 10 microns in diameter and about 0.1 microns thick. The crystals were filtered off, washed with water and air-dried * The crystals thus obtained were resuspended and stirred in ethanol, a streamlined pattern with excellent pearlescent was observed. The so obtained Crystals can therefore be used as pearl pigments.

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Claims (5)

Patent claims: (Q method of making synthetic pearlescent Pigments in the form of thin platelets Crystals with a smooth surface and uniform shape and size from at least one of the compounds triazine or Iriazine derivatives, characterized in that the crystallization performs in the presence of at least one surfactant. 2. The method according to claim 1, characterized by that one uses triazine. 3. The method according to claim 1, characterized in that 2,4 »6-triamino-s-triazine is used, 4. The method according to claim 1, characterized in that 2,4,6-trihydroxy-s-triazine is used. 5. The method according to claim 1, characterized dadurcii, that one can obtain crystals 3 to 100 microns long, 1 to 40 microns wide and 0.05 up to 3 microns. _# 6 The method of claim 1, characterized in that one applies the surfactant in an amount of 0.001 to 1 wt. ^ Based on the weight of the Keaktionsflüssigkeit. 10983072077