DE1131403B - Process for the production of curable aminotriazine condensation products - Google Patents

Description

Process for the preparation of curable aminotriazine condensation products Addition to Patent 1103 582 The main patent relates to a method of manufacture curable aminotriazine condensation products by condensation of aminotriazines or of mixtures of different aminotriazines with formaldehyde, which thereby is characterized in that such aminotriazines or mixtures thereof are used, which contain nitrogen-bonded alkanol radicals with at least 2 carbon atoms, being the average number of nitrogen present per aminotriazine molecule bound hydrogen atoms must not be less than three.

According to this process, aminotriazine resins are particularly good Maintain flow properties. According to a preferred embodiment of the method Modified melamine resins with significantly improved flowability are also available then still obtained if you put small in a melamine resin of the usual composition Amounts between 0.0005 and 0.1 moles per mole of melamine of an N-alkanol melamine with a condensed in up to six alkanol residues. Alkanolmelamines are preferred here Products which contain no more than 4 carbon atoms per alkanol radical are used, z. B. N-ethanol melamine, N-propanol melamine, N-isopropanol melamine, N-diethanol melamine, N, N'-diethanol melamine, N, N ', N "-triethanol melamine, N, N'-tetraethanol melamine or N, N ', N "-hexaethanol melamine.

It has now been found that the process for the preparation of curable Aminotriazine condensation products by condensation of aminotriazines or of Mixtures of various aminotriazines with formaldehyde, such aminotriazines or mixtures thereof are used which contain alkanol radicals bonded to nitrogen contain at least 2 carbon atoms and furthermore the number of on average hydrogen atoms bonded to nitrogen not present per aminotriazine molecule is less than three, according to patent 1 103 582, can be trained by at the polycondensation amides of aromatic sulfonic acids or carboxylic acids are also used. Those amides are preferably used which are in the weakly alkaline aqueous or aqueous-alcoholic condensation solutions have sufficient solubility.

Suitable amides are, for example, benzenesulfonamide, ortho- or para-toluenesulfonamide, naphthalene-oc- or -p-sulfonamide, benzamide or p-toluic acid amide. N-substituted amides are also suitable, e.g. B. N-methylbenzenesulfonamide, N-phenyltoluenesulfonamide, N-ethylbenzamide or p-toluene disulfimide; instead of the acid amides one can also use their low molecular weight condensation products with formaldehyde, e.g. B. N-methylol toluenesulfonamide, use.

The amount of amide added can vary within wide limits. For the production of a melamine resin with significantly improved flow properties Additions of 0.05 to 0.5 mol per mol of melamine are sufficient.

Mixtures are preferably processed which contain 0.0005 per mole of melamine to 0.1 mole of an N-alkanol melamine and 0.05 to 0.5 mole per mole of an amide.

For the production of the resins according to the invention, for example Melamine and formaldehyde in a molar ratio of 1: 2 to 1: 6 with the addition of the above Amounts of substituted melamines and acid amides condensed. The formaldehyde can be used in the form of commercially available aqueous solutions, which are about 30 contain up to 40% of the aldehyde.

The condensation is advantageous at a pH of 7.5-10 and carried out at an elevated temperature between about 50 and 100 ° C. It is appropriate to keep the pH constant during the condensation. The end point of condensation, which can be chosen differently for the different purposes of the resin can easily be determined by the well-known dilution test with water.

To carry out the condensation, the reactants in can be added in different order. For example, you can use melamine and Then condense formaldehyde and the alkanolmelamine in a known manner add the aromatic acid amide and then condense further.

It is also possible to create a melamine-formaldehyde precondensate, in which an alkanol melamine or a mixture of different alkanol melamines condenses is, subsequently, a condensation product of formaldehyde and an aromatic Acid amide, e.g. B. add the N-methylol toluenesulfonamide in the form of an aqueous solution. Of course, you can also share all of the participants in the reaction from the outset let react.

After the condensation, the aqueous or aqueous-alcoholic Process the solution of the precondensate further in the usual way. You can z. B. converted into a powder by spray drying or by drying on rollers. One can also use the solution of the precondensate compared to a solution of the unmodified Resin has an extended service life, directly for a wide variety of purposes use, whereby the service life by common condensation retarders, such as borax or urotropine, can be further prolonged. The hardening of the resin can be done in a known manner Wise done by heating, where appropriate customary curing catalysts can be added.

The invention is explained in more detail by means of the following examples. The content of volatile constituents or the residual moisture was determined by 10 Heating the finely divided, predried resin-filler mixture for minutes determined at 150 ° C.

Mixed condensation products are already used for the production of multilayer bodies from melamine, formaldehyde, toluenesulfonamide and small amounts of ammeline, or ammelide Cyanuric acid used.

From this, however, it was not to be inferred that the Flowability of the modified ones produced according to the process of the main patent Melamine resins by adding amides of organic sulfonic acids or carboxylic acids can improve significantly.

Example 1 A mixture of 252 g of melamine, 500 cm3 of 30 "/ liquid formaldehyde solution and 2.14 g of N-diethanolmelamine was adjusted to pH with dilute sodium hydroxide solution set of 8, 5. The mixture was then heated to 80 ° C. with stirring and kept at a constant pH of 8.5 for 30 minutes at this temperature.

Then 85.5 g of p-toluenesulfonamide were added and up to one Precipitation number of 1: 1 condensed.

It was then cooled and filtered.

Part of this solution was kneaded vigorously at room temperature Alfacellulose entered in powder form up to a filler content of 40% on total solids. The mixture was then placed in a vacuum dryer dried at 50 ° C to a residual moisture content of 5 or 8%. After that it was the mixture is crushed, pulverized and pre-compressed into pills of 0.85 g each. These Compound pills were in a Battenfeld flow tester (flow test according to Rossi Peakes, ASTM D 569-48) at 160 ° C and a pressure of 130 kg / cm2 on their flowability checked.

The data of the device are: flow channel diameter 3.2 mm flow channel length ..... 60.0 mm load ............... 83 kg counterweight ................... 0.220 kg Tablet diameter ............ 0.92 cm The table below shows the achieved Results at a volatile content of 5 and of 8 ° / o In comparison, the results are given with those with a melamine resin (Resin A), which is prepared in the same way, but without the addition of diethanol melamine and toluenesulfonamide prepared. Resin B is that above modified resin described. Resin C was made in the same manner as Resin B, but without the addition of diethanol melamine.

Table 1 resin AAIBICIAIBC Fugitive Components (° / 0) .. 5.0 5.0 5, 0 8, 0 8, 0 f 8, 0 Flow (mm) ........ 5 38 30 6 48 1 35 Example 2 A modified melamine resin was prepared in the same way as in Example 1, with the difference that 3.02 g of N, N'-tetraethanol melamine were used instead of N-diethanolmelamine.

The flowability was determined in the same manner as in the example 1. The values obtained are shown in Table 2 below. Resin A is again the unmodified, resin D the modified resin.

Table 2 resin AIDIAID Volatile components (° / 0) 5, 0 5, 0 8, 0 8, 0 River 5 45 6 1 50 Example 3 A mixture of 630 g of melamine, 10.7 g of N-diethanolmelamine and 755 cm3 of a 37% aqueous formaldehyde solution was adjusted to a pH of 8.5 using sodium hydroxide solution and heated to 90 to 95 ° C. with stirring, the pH value was kept constant by adding more sodium hydroxide solution. The mixture was then condensed at 90 to 95 ° C. and at the same pH value until a precipitation number of 1: 3.5 was reached. 85.5 g of p-toluenesulfonamide and a further 75 cm 3 of the 37% aqueous formaldehyde solution were then immediately added and the reaction mixture was cooled to room temperature.

The pus-vert was set to 10 while cooling down. The fluidity this resin was tested in the same manner as in Example 1. The resin drew are characterized by a particularly good flowability.

Example 4 A mixture of 630 g of melamine, 10.7 N-diethanol melamine and 755 cm3 of 37% aqueous formaldehyde solution was brought to a pH of 8.5 set and heated with stirring to 90 to 95 ° C, the pH drop during the heating was compensated by adding sodium hydroxide solution. Subsequently was condenses at a temperature of 90 to 95 ° C and at a pH of 8.5 so far, until a precipitation number of 1: 3.5 was reached. After that they were immediately 60.5 g of benzamide and a further 75 cm3 of 37% aqueous formaldehyde solution were added. After the addition, the condensation solution was cooled to room temperature, whereby the pH of the solution was adjusted to 10.

The flowability of the resin was determined in the same manner as in Example 1 checked. The values obtained are shown in the table below 3. Resin E is the resin made according to the present example.

Resin F was prepared in the same way, but without the addition of diethanol melamine manufactured.

Table 3 resin EEIF I. Volatile components (° / 0) 5.0 5, 0 8.0 8.0 Flow (mm) ............ 33 28 39 28 Example 5 A mixture of 630 g of melamine, 10.7 g of N-diethanolmelamine and 755 cm3 of a 370% aqueous formaldehyde solution was adjusted to a pH of 8.5 and heated to 90 to 95.degree. The pu value was kept constant by adding more sodium hydroxide solution. The mixture was then condensed at 90 to 95 ° C. and at a pH of 8.5 until a precipitation number of 1: 3.5 was reached.

Then 77.5 g of benzenesulfonamide and another 75 cm3 of a 37% aqueous formaldehyde solution was added, and the reaction mixture became cooled to room temperature, the pH being adjusted to 10.0.

The flowability of the obtained resin was determined in the same manner tested as in example 1. Table 4 shows the results obtained. Resin G is the resin prepared according to the previous example, while Resin H in the same Way, but without the addition of diethanol melamine.

Table 4 resin GIHIGIH Volatile components (° / 0) 5, 0 5, 0 8, 0 8, 0 Flow (mm) 33 29 36 30 Example 6 A mixture of 630 g of melamine, 1010 g of a 30% aqueous formaldehyde solution and 10.7 g of N-diethanolmelamine was at a pH of 8.5 and a temperature of 90 ° C in the same manner as in Example 1 described, condensed to a precipitation number of 1: 3.5 (at 20 ° C). After the stated precipitation number had been reached, 85.5 g of p-toluenesulfonamide and a further 100 g of the 30 "/ in aqueous formaldehyde solution were added. The reaction mixture was then cooled to 40 ° C. over the course of 20 minutes. The pH of the solution was increased during the cooling adjusted to 10.0 with dilute sodium hydroxide solution, then the resin solution was diluted with water to a solids content of 50%.

A gray decorative paper with a weight of 175 g / m2 was used with this Resin solution impregnated and dried in air at room temperature for 16 hours. The resin application was 74% of the weight of the paper.

To determine the volatile constituents, samples of the impregnated Paper 10 10 cm in size after-dried for 10 minutes at 150 ° C. The content of volatile Constituents was 5.99%.

Nine disks of the impregnated paper with a diameter of 6.9 cm were placed on top of one another and at a temperature of 140 ° C. and a compression pressure of 80 kg / cm2 pressed for 15 minutes. That over the circumference of the round body during the pressing Exiting resin was stripped off and the percentage weight loss (flow) des Specimen determined. The flow was 2.07 per cent.

Furthermore, a laminate was produced from the following components : Top layer: One impregnated with modified melamine resin according to the present example Decorative paper.

Middle layer: nine soda kraft papers impregnated with a mixed condensate from melamine-urea-formaldehyde.

Underside: decorative paper impregnated with modified melamine resin according to the present example.

The pressing took place under the following conditions: pressing temperature 140 ° C, pressing pressure 80 kg / cm2, pressing time 15 minutes, followed by re-cooling to 30 ° C within 25 minutes.

The surface gloss of the laminated panels produced in this way was measured with the help of an electrical gloss meter (universal meter No. 276 of Company Dr. B. Lange, Berlin). This resulted in ten individual measurements the mean value found. The values were recorded on a black calibration plate (100 ° / o) related. A value of 121.5% was obtained when using the modified melamine resin determined according to the present example.

The abrasion values of the laminate were measured in the Tabor Abraser device established. For this purpose, the samples were subjected to a grinding load of 200 revolutions subjected to a weight of 500 g. The percentage weight loss was 0.45%.

In addition, the laminate panels were the water vapor test and the Testing of the behavior against hot pot bottoms (both according to DIN draft 16 926). Apart from a slight loss of gloss, no changes were found, so that the laminate panels meet the standard.

Example 7 In the same way as described in Example 6, was made a modified melamine resin, but with the difference that in place of 85.5 g of p-toluenesulfonamide, a mixture of 42.5 g of o-toluenesulfonamide and 30.25 g benzamide was used.

A decorative paper of 150 g / m 2 was made with the resin solution obtained Weight in the same way as described in Example 1, impregnated and up predried to a volatile content of 2%. The resin application was 85% of the weight of the paper.

With the aid of the paper impregnated in this way, a laminate was made manufactured. The compression was carried out at 140 ° C. and a compression pressure of 80 kg / cm2. The pressing time was 15 minutes.

It was then cooled back to 30 ° C. in the course of 25 minutes. Of the The laminate obtained was very good even without the use of an overlay paper Surface property.

Claims (2)

PATENT CLAIMS: 1. Further development of the manufacturing process aminotriazine curable condensation products by condensation of aminotriazines or of mixtures of different aminotriazines with formaldehyde, such aminotriazines or mixtures thereof are used which contain alkanol radicals bonded to nitrogen contain at least 2 carbon atoms, and furthermore the number of on average hydrogen atoms bonded to nitrogen not present per aminotriazine molecule is less than three, according to patent 1 103 582, characterized in that at the polycondensation amides of aromatic sulfonic acids or carboxylic acids are also used. 2. The method according to claim 1, characterized in that mixtures used, which per mole of melamine from 0.0005 to 0.1 moles of alkanol melamine and from 0.05 to Contains 0.5 moles of amide. Documents considered: German Auslegeschrift No. 1 055 230.