DE752582C - Process for the production of paints - Google Patents

Description

ISSUED ΑΛΙ
9. MXRZ 1953

REICH PATENT OFFICE

CLASS 22h GROUP

G 95589 IVc 122h

The invention relates to a method for the production of paints, with F'ormaldehydkoruleusationsprodukte as paint binders or paint additive of amiiiotriazines can be used.

Methods for making such condensation products include: in the German Patent specification 647 303 and described in French patent specification 811 S04.

As a representative of the aminotriazines comes in particular the 2, 4, 6-Triamiiio-i, 3, 5-triazine, usually called melamine, which has proven to be particularly beneficial. In addition, the derivatives of melamine come into consideration, as they are, for example, from this arise through deamidation, such as melam, melen, melon, or as they arise by replacement of one or two amino groups are formed by OH groups, such as ammeline and ammelide. Other derivatives can also be used are used in which some of the amino groups are replaced by other groups of the most varied Kind such as B. hydrogen, halogen, aryl, alkyl or aralkyl groups, is substituted. As a representative of such derivatives are mentioned: 4, 6-diamino-1, 3, 5-triazm (Formoguanamine), 2 - chloro - 4, 6 - diamino J. 3; 5-triazine, 2- (p-0xyphenyl) -4, 6-diamino- '· 3. 5-triazine, 2-phenyl-4-amino-6-oxyi, 3, 5-triazine, etc. One can also use these

Derivatives of aminotriazines run out in which the hydrogen atoms of the amino groups are replaced in whole or in part by the above-mentioned groups, such as. B. symmetrical Triarylmelamines, mono-, di-, trialkylmelamines or corresponding aralkylmelamines etc. The isoderivatives of aminotriazines are also suitable, according to the known The possibility of storing the triazine ring in its isoform is the hydrogen atoms of the ring nitrogen also replaced in whole or in part by substituents of all kinds could be.

The following description considers in particular the not claimed herein preparation of formaldehyde condensates of 2, 4, 6-Triaminoi, 3,5-triazine (melamine), but it applies, mutatis mutandis, for other amino triazines or derivatives of aminotriazines.

Melamine reacts surprisingly easily with neutral aqueous formaldehyde solutions, namely in all possible molecular proportions of melamine to Formaldehyde. In the cold, methylol compounds are formed with prolonged exposure to the bucket, which precipitate out of the solution in crystalline form when the concentration is appropriate can. In the warmth the λίείΐινίοΐ connections formed in a very short time, e.g. B. by cooking for a few minutes, and can be eliminated by cooling. Hei further exposure to heat occurs rapid formation of hydrophilic and then hydrophobic resins with further condensation one, which the latter is already in the warmth when cooling or with a longer reaction time deposit with formation of layers. With even longer exposure to heat, it finally occurs Curing via a rubbery phase to an insoluble polymerisation product. Depending on the desired condensation product, the reaction can be carried out in any Interrupt the condensation phase and the condensation or resinification product in known way by filtering off, evaporation. Separation, decanting. Win drying, etc.

The hydrogen ion concentration has a very great influence on the rate of the reaction. In the case of a neutral or weakly alkaline reaction, the condensation generally proceeds the slowest. at With a weakly acidic reaction, a very strong acceleration of the condensation is achieved. Strongly alkaline reactions also accelerate condensation.

Depending on the direction of the condensation, they are easily distorted in all molecular ratios from melamine to formaldehyde, e.g. B. 1: ι to i: JO, clear hydrophilic or hydropholx 'Kon- j densification products. Here are the hydrophobic properties of the condensation products, in particular due to the pn ratios of the solutions, can be largely influenced.

That much is often not necessary for the manufacture of technical condensation products To bring formaldehyde to the reaction than can be bound, as the maximum condensation products obtained with less formaldehyde have good technical properties exhibit.

The condensation can also be carried out in several stages by first either melamine or formaldehyde used in the oil and then on the reaction mixture formed in one or more stages that is in deficit Brings component to action. For example, 1 mole of melamine Va mol formaldehyde to act and the resulting product with further amounts Treat formaldehyde. But you can also first use condensation products with a lot of formaldehyde and make them react with additional amounts of melamine.

The reaction of melamine with formaldehyde can also take place in organic media instead of in aqueous solution, with direct solutions of the condensation products in question in organic solvents. B. nitrocellulose lacquers. Can find application. Such organic solvents are, for. B. ethyl and butyl alcohol or the glycerides of linseed oil fatty acid mentioned. The condensation can also be carried out in aqueous-organic solvents, e.g. B. 50 ⁰ / pc alcohol aqueous alcohol.

The condensation of melamine and formaldehyde is also possible with the exclusion of solvents, for example using paraformaldehyde.

When using solvents, it can be advantageous to carry out the reaction in the closed Make a vessel (autoclave), which also makes it possible to adjust the reaction temperature to choose above the boiling point of the solvent, such as. R. 1> ei ethyl alcohol. The formaldehyde condensation products of the obtained by the reaction described Melamins have very good heat-curing properties, i.e. they are under infusible to the influence of heat and insoluble: they are also lightfast and free from Kigenfariie. The surprisingly good one Thermal stability of the condensation products is expressed as a great advantage in ilite hardening by hardening not tied to tight temperature limits

Claims (4)

is, but extends over a wide temperature range can extend. The melamine resins are in this regard the phenolic resins similar. Furthermore, the formaldehyde condensation products of the melamine in the hardened state has surprisingly good water resistance. In a manner similar to melamine, other aminotriazines or their derivatives can be used ίο be converted into their corresponding condensation products with formaldehyde. Instead of using the aminotriazines alone you can the condensation also with the addition of compounds which form resins with aldehydes, like phenols. Urea, thiourea, aniline and the like, or mixtures thereof , whereby co-condensation products are obtained. Here, too, can the condensation can be carried out in several stages, with z. B. the retrospective added component to one with sufficient Amount or an excess of formaldehyde produced primary condensation product can be added. One can 25 * also the aminotriazine condensation products with other natural or artificial Resins, e.g. B. phenol-formaldehyde resins, or urea bz \ v. Thiourea-formaldehyde condensation products mix or condense further. Furthermore, further substances can be used at each stage of condensation, like dyes. Fillers, plasticizers, water repellants, etc. are added will. _π . . , example 1 50 parts by weight of a methylol compound of melamine are added to 80 parts by volume of butyl alcohol and 0.5 parts by volume of concentrated hydrochloric acid and the mixture is heated to boiling for ^{1 hour.} The result is an almost clear solution, which quickly dries in a thin layer in the heat to form a hard lacquer and hardens. Such solutions in butyl alcohol can, for. B. Xitrocellulose lacquers are added to give them hardness and filling power. The methylol compound of melamine is according to French patent 811 804 manufactured as follows: 1 2.6 parts by weight (0.1 mol) of melamine are dissolved in 75 parts by volume (0.8 mol) of 32 percent by volume, neutral formaldehyde in a Mvfk-mlen water bath and left there for minutes. This is followed by cooling, with flakes already separating out when cooling down. After 2 days, the crystal pulp is suction filtered, washed thoroughly with alcohol and dried at 60 ° for 5 hours. Example 2 50 parts by weight of xitrocellulose (tVa-Sekunlon wool) are mixed in a mixture of 110 parts by weight of tricresyl phosphate and 10 parts by weight of isutyl alcohol. 50 parts by weight! Ethyl acetate and 40 parts by weight of toluene! solves. 100 parts by weight of an alcoholic melamine resin solution are added to the very thick, pasty solution obtained! stirred, which by heating 126 parts by weight of melamine (1 mol) with 300 parts by volume of a 4i, 8 ° Zoigen. Alcoholic formaldehyde solution (5 mol), 300 parts by volume of alcohol and [part by volume of concentrated hydrochloric acid (0.01 mol) under reflux for 45 minutes and then cooling egg solution. The water-clear solution obtained is diluted for use with a mixture of equal parts of toluene, absolute alcohol and ethyl acetate. The solution dries, poured onto glass or metal, water-white and mirror-smooth and, when cured at a slowly increasing temperature, the temperature being ^{kept at 120 ° for about 1} hour, paint films of very good water resistance and hardness. Example 3 ^8s 1.1 part formoguanamine (0.01 mol) are treated with 3 parts of neutral formaldehyde 30 ⁰ / oig (0.03 mol) of 4 Za ¹ hour in a boiling water and then cooled. The result is a clear solution which, when diluted with water. Resin separates. If this solution is applied to a base and dried and hardened at a higher temperature, a clear, hard, water-resistant coating is obtained. Example 4 6.3 parts by weight of melamine ('Vso mol), r5 parts by volume of 4 8 ° alcoholic formaldehyde (V20 mol), 15 parts by volume of absolute alcohol, ο, ι part by ^{volume of concentrated hydrochloric acid (1} cmO mol) and 0 parts by weight of the monoglyceride of linolenic acid are combined 3 ^{left to react for 1} Za hours on the boiling water bath under reflux. The result is an efrvas cloudy, slightly yellowish, oily liquid which, on further evaporation, finally solidifies into a tough, clear, rubber-like mass. If, however, the oily condensation product is diluted with a little benzene before it solidifies and, expediently, according to Zugalx; of a siccative, applied to a base, it dries in the air after a while to form clear, transparent, hard coatings that can no longer be scratched with the Xagel. Ρλ τ ε ν τ α ν s ρ η ü c 111 :: i. Process for the production of paints, characterized in that one here as a paint binder or paint Addition of formaldehyde condensation products used by aminotriazines. 2. The method according to claim i. characterized in that a formaldehyde condensation product of 2, 4, 6-triamino-i, 3, 5-triazine is used. 3. The method according to claims 1 and 2, characterized in that one produced in the presence of an acidic or basic condensing agent Condensation product is used. 4. The method according to claims 1 to 3, characterized in that a mixed condensation product is used is obtained by adding other substances that condensation products with aldehydes able to form. To delimit the subject matter From the state of the art, the following publications are considered in the granting procedure been drawn: French patent specification No. 719 929, 684317, 644075, 811 804.