DE2603767A1 - Methylolamino-triazines etherified with glycols - are devoid of electrolytes and useful for mouldings, laminates and coatings - Google Patents

Abstract

Etherified methylolaminotriazines (I) are devoid of electrolytes and contain (statistical average) 1.3n-2n, esp. 1.8n-2n, methylol gps. per molecule of aminotriazine (n= no. of amino gps. in the aminotriazine), these methylol gps. being >=33, pref. >=50% etherified by glycols of formula (II) R-(-OCH2CH2)mOH(R=1 -4C alky6; m=1-4). Pref. R=CH3 and n=1 or 2. (I) are heat hardenable and can be used to make moulded objects laminates or coatings. They have excellent elasticity and water resistance, and for electrical use excellent electrical stability and resistance to arcing. No catalysts are needed in prepn.

Description

Process for the production of moldings and

Surface coatings The present invention relates to a Process for the production of moldings and surface coatings by pressing or pressing on a thermosetting combination of an aminoplast resin with one Carrier or filler material and possibly other known additives such as pigments, Flow aids and lubricants or release agents at elevated temperatures, thereby characterized in that an electrolyte-free etherified methylolaminotriazine is used as the aminoplast resin is used, the statistical mean per mole of aminotriazine 1.3 to 2 Contains n methylol groups, where n is the number of amino groups of the aminotriazine which is at least 33 "with a glycol derivative of the general formula I R- (OCH; 22H2) mOH where R is an alkyl group with 1-4 carbon atoms and m is an integer of 1 to 9 are etherified.

It is known to produce molded bodies by pressing combinations of thermosetting Amino resins, carrier materials and, if necessary, other additives such as pigments, To produce flow aids and lubricants or release agents at elevated temperatures.

Carrier materials that are suitable for this purpose are in principle all absorbent inorganic or organic structures. In particular, are flat Materials used, such as webs of fabric made of natural or synthetic Fibers, especially cellulose fibers or random fiber fleece, especially paper. Wood veneer can also be used as a carrier material for the resin.

The carrier materials mentioned are combined with the aminoplast resins in in a known manner, for example by applying with brushes or with rollers, spraying on or immersion impregnated, the procedure being generally so that the impregnated Materials contain 25 to 75% of the aminoplast resin. After impregnation will be the materials are dried to a residual moisture content of 1 to 11%. The so sheet-like combinations obtained are in several layers one above the other and at temperatures between 110 and 1700C and pressures between 2.0 and 800 kp / cm² pressed into moldings.

The sheet-like combinations of carrier material with amino resins are also suitable for the surface coating of other materials, for example Wood or chipboard.

In the Mcbel industry, for example, they are used for coating used by chipboard, hardboard or plywood panels or other wood-based materials. Here, the carrier materials impregnated with aminoplast resin are used a gluing agent under the action of heat and pressure on the wood-based materials pressed on. Filled urea resins and melamine resins are used as gluing agents and / or offcuts the same as well as so-called Kaitleime based on polyvinyl acetate dispersion.

Another known possibility of producing moldings by pressing, consists in aminoplast resins with powdery fillers and optionally other known additives such as pigments, flow aids and optionally Combine lubricants or release agents and these products at elevated temperatures to press into molds. Known filling materials that are used in such molding compounds are, for example, wood flour, cellulose powder, rock flour, and asbestos fibers or graphite, of which the first two are preferred. Pigmento used in molding compounds can be organic or inorganic. Inorganic pigments are generally based on sulfides, oxides or mixed oxides of metals, in particular of titanium, zinc, iron, chromium, cobalt, lead and cadmium. Eln preferred black The pigment is soot. The organic pigments come in the color index as pigment dyes marked connections into consideration.

Well-known flow aids are sorbitol, glycols and glycol derivatives and polyglycols.

As a lubricant or release agent, which is essential for the proper removal of the Moldings are required from the die, metal stearates are preferred Zinc and magnesium stearate are used.

Mixing the aminoplast resins with the filler material and optionally the other additives are made in known Mixing units such as kueters or roller mixers and can be used at elevated temperature up to about 1200C.

The properties of those produced by one of the methods given above Shaped body is to a large extent dependent on the type of aminoplast resin used. The aminoplast resins that have been capped up to now have disadvantages that are their usability for the purposes indicated above, in some cases significantly restricted. So were for example by soaking paper or fabric webs with the previously named melamine Resins producible foils are not sufficiently elastic for some purposes. It was known that the elasticity and thus the bending radius can be improved can if the aminoplast resin modifiers such as glycols can be added. However, with the resulting improvement in elasticity a compromise of the water resistance connected, so that the foils for some Applications for example for wrapping profile strips are not used could. Also by pressing the by impregnating paper or fabric webs or laminates produced from veneers with known amino resins or wooden moldings did not show sufficient elasticity, especially when the point is to use the molded parts produced where they alternate are exposed to thermal stress.

The aminoplast resins known to date also showed in electrical engineering produced moldings due to their electrolyte content are not the desired Properties such as high electrical resistance and high creepage resistance.

Previously known etherified methylolaminotriazines were produced by ethylolation and simultaneous or subsequent etherification of the methylolaminotriazines in the presence of acidic catalysts (cf. Houben-Weyl, Vol. 14/2, pages 359-368; Ullmann Encyclopedia of techn. Chemie Vol. 3, pages 487-489).

The degree of methylolation is here, for example, in the case of melamine generally 3-6. After the reaction had ended, it was necessary to add the acidic Neutralize the catalyst and remove the resulting salt by filtration.

However, this was generally only incomplete, so that during storage the products produced in this way, undesirable cloudiness occurred, which on further notice Nachlallen of the salt are due and the rest of the non-removable Salt residues lead to an extraordinarily strong reduction in electrical resistance and the tracking resistance of those made with such aminoplast resins Molded bodies led.

Previously known methylolaminotriazines etherified with long-chain alcohols were previously mainly by Umtherun the corresponding methyl ethers under Acid catalysis won.

Surprisingly, it has now been found that laminates and molded wood parts can be used with high elasticity and high water resistance as well as electro laminates and Moldings with high electrical resistance and high tracking resistance can be produced if an electrolyte-free etherified methylolaminotriazine is used as the aminoplast resin uses, the statistical mean per mole of the aminotriazine 1.3 to 2 n methylol groups contains, where n is the number of amino groups of the aminotriazine, the at least 33% with a glycol derivative of the general formula I R- (oCH2CH2) mOH wherein R is a Denotes an alkyl group with 1-4 carbon atoms and m denotes an integer from 1 to 4, are etherified.

Glycols of the general formula I, which are used for the production of the invention to be used; * etherified methylolaminotriazines can be used For example, ethylglycol, ethylglycol, diglycol monomethyl ether, diglyol monoethyl ether, Diglycol monopropyl ether, triglycol monomethyl ether, triglycol monoethyl ether, triglycol monopropyl ether, Triglycol monobutyl ether, tetraglycol monomethyl ether, tetvaglycol monoethyl ether, Tetraglycol monopropyl ether, tetraglycol monobutyl ether. Aminotriazines used to manufacture the etherified methylolaminotriazines to be used according to the invention are, for example, melamine, benzoguanamine and acetoguanamine.

Those methylolaminotriazines are preferably used, which in the statistical Average per ttol of aminotriazine 1.8-2 n methylol groups, especially those which contain 0.8 n -1.2 n methylol groups per mole of the aminotriazine. Furthermore are those methylolaminotriazines are preferred in which at least 50% of the methylol groups are etherified. Of the glycols of the general formula used for etherification I preferred those in which R is a methyl group and also those where m stands for the number 1 or 2. Particularly preferred glycols of all n Formula 1 are those in which R denotes a methyl group and m denotes the Number 1 or 2. Another group of preferred ones to be used according to the invention Methylolaminotriazines are the ones that do. derived from melamine.

It was surprising that when using alcohols the general Formula I R- (OCEI2CI12) OH I for the etherification of the Methylolaminotriazine the use acidic catalysts is not required and that the molar ratio of aminotriazine to formaldehyde can be varied within much wider limits than has been the case up to now is known in normal etherified melamine-formaldehyde condensates.

Because of the absence of acidic catalysts there is no neutralization of the reaction mixtures required so that completely electrolyte-free products are obtained will.

The absence of electrolytes is crucial for the excellent electrical properties of the moldings 1 according to the invention and the wide range the degree of methylolation allows the properties of the products according to the invention especially with regard to elasticity, water resistance and temperature and thermal shock resistance to adapt to extreme practical requirements.

The preparation of the etherified methylolaminotriazines to be used according to the invention takes place by condensation of an amirotriazine with formaldehyde and an excess of the glycol of the formula I, with 1.3-2 n moles of formaldehyde per mole of the aminotriazine - If n is the number of amino groups of the aminotriazine - is used and the condensation is carried out in the absence of acids and alkalis. The condensation runs at temperatures from 50 to 1800C, preferably PO to 140C.

The condensation is continued until the degree of etherification of the reaction product is at least 33%. The excess glycol to be used can be 1.2 + to 20 times the theoretical amount. After reaching the desired degree of condensation the remaining excess glycol is distilled off, preferably in vacuo is being worked on. The water of reaction formed during the condensation is preferred continuously distilled off. The water of reaction is also distilled off expediently carried out in vacuo.

Provided that the water of reaction distilled off continuously during the reaction the degree of etherification achieved of the reaction product can be determined from the amount thereof to be determined.

The formaldehyde is preferably used in the form of paraformaldehyde. However, aqueous solutions of formaldehyde or solutions can also be used of formaldehyde in the alcohols used according to the invention for etherification general formula I.

The inventive production of moldings using the etherified methylolaminotriazines described above takes place in such a way that the etherified methylolaminotriazine is combined with a carrier or filler and pressing the combinations under pressure at elevated temperature to form moldings. The combinations can be obtained by, for example, sheet-like absorbent materials such as fabric webs, random fiber tiles or wood veneers impregnated with the amino resins to be used according to the invention.

The impregnation can be carried out in a manner known per se, for example by brushing or roller application, by spraying on or by dipping. Powdery filler materials are mixed with the aminoplast resins to be used according to the invention mixed. Mixing is also carried out in a manner known per se, for example in kneading units, on roller sleeves or similar known mixing units.

Sheet-like support materials are generally based on a resin content from 25 to 50, preferably 30 to 40%, based on the total combination. Molding compounds obtained by using powdery filler materials can be 40 to 70 preferably contain 50 to 60% of the aminoplast resin.

Other known auxiliaries and modifiers can also be added to the combinations are added according to the state of the art. So it is possible, for example, the railway carrier materials prior to impregnation with pigment dyes to be printed decoratively or, if it is celiulosef £ -ser- or textile fiber-containing sheet-like carrier materials act to this with textile dyes. to dye or to print. The combinations made with powdered filler material can also be pigmented and or contain release agents that ensure the proper detachment of the molded body from the Ensure compression shape.

To produce moldings, several layers of the sheet-like Combinations at temperatures between 110 and 1700C, preferably 130 to 1500C and under pressures of 50 to 120 kg / cm2, preferably 80 to 100 kg / cm2 to laminates pressed.

Preferred base material for random fiber tiles and fabric sheets is Cellulose. However, other known fiber materials can also replace the sheet-like Are based on carrier materials. The use of absorbent is particularly preferred Papers as a flat carrier material.

Cellulose powder is primarily used as a powder filler used. Other suggestions relate to the use of cellulose, Wood flour, cotton flakes or cellulose ester powders. Furthermore are used Flour, starch, but also peat or other waste from the wood industry.

Known lubricants, which are to be pressed according to the invention in the Combinations that can be included are, for example, zinc, magnesium or Calcium stearate.

The kneading of the powdery filling materials with the invention Amino resins to be used can preferably be used at temperatures between 70 and 140 105 to 120 ° C.

The kneading at elevated temperature brings in relation to the Kneading required energy and the achievable homogeneity of the combination essential Advantages. After mixing, the resulting combination is at room temperature cooled, generally solidifying. The solid product is then granulated and can then be pressed. The pressing is generally carried out at temperatures between 120 and 1800C, preferably 140 and 1700C with pressures from 200 to 800 kgf / cm preferably 400 to 600 kgf / cm2. The pressing time is Manufacturing of laminates in 10 to 60 minutes, in the production of moldings using powdered filler materials at 30 seconds to 5 minutes.

Surface coatings using the combinations according to the invention are generally manufactured in such a way that, as in the manufacture of laminates first a sheet-like carrier material is impregnated with the Prz. The impregnation is carried out as described above, the resin content of the combination can be between 25 and 45, preferably 30 to 40% based on the weight of the entire combination lie. As described above, the impregnated carrier materials are up to post-dried to a residual moisture content of 3 - 10 0. The flat-shaped ones obtained in this way Resin-carrier combinations are applied to the surfaces to be coated using an EJaftvermittelers under a pressure of 2 to 12 kp / cm², preferably 4 to 6 kp / cm² and at temperatures between 110 and 170, preferably 140 and 1500C.

The pressing time is generally 30 seconds to 4 minutes, preferably 1 to 2 minutes. In this way it is also possible to make decorative surface coatings to produce by using a corresponding printed or colored decorative paper is used. With the to be used according to the invention The combination can also be curved because of its extraordinarily high elasticity Coat surfaces such as profile strips perfectly. It is also possible, for example, to coat chipboard all around by using the planar combination pulls around the edges. That was known to date Aminoplast-based coating agents not possible. Here the individuals had to the upper surfaces are coated separately.

The laminates which can be produced according to the invention are distinguished due to excellent elasticity and very good water resistance at the same time the end. Because of their extremely high resistance values and high tracking resistance they are ideally suited for the production of components in the electrical industry. Moldings according to the invention also have the same valuable properties, which were produced using pulverulent materials.

Further advantages of the moldings and can be produced according to the invention Surface coatings are their resistance to high and low temperatures ud against temperature changes, the excellent Martens dimensional stability, high Impact strength and flexural strength and low post-shrinkage.

Example 1: 5300 ml of methyl glycol, 1372 g of melamine, 650 g of p-formaldehyde are stirred at 1200C. This solution is clear after 1 1/2 hours. It will be about 1.5 1 methyl glycol distilled off. A melamine resin solution with a content is obtained of condensate of 66% (determined by the weight loss on a sample through lstd. Heating at 1200C), an unlimited water dilutability and a limited Can be diluted with n-butanol, i.e. 1 part of the present resin can be mixed with 1 part n-butanol can be diluted at 20 ° C. without the occurrence of turbidity.

Analysis of the product shows that 15.4 70 as bound formaldehyde and 21.3% is present as bound methyl glycol.

The solvent content is 33.8%; determined as methyl glycol.

In this solution, 10 sheets of an 80 g / m2 heavy electrolyte-free Impregnated paper. The resin content is after drying, which is carried out at 1300C is approx. 60%, the residual moisture content (determined by drying a sample for 5 minutes at 1600C) approx. 6%.

The pressing of the superimposed papers takes place in a Multi-daylight press between high-gloss chrome-plated nickel sheets at one temperature of 1400C, a pressure of 80 kp / cm2 and a time of 15 min.

After cooling the laminate under pressure to approx. 700C it is obtained a 1.1 mm thick laminate. At this Become non-toxic the following data measured: Cure level Kiton test: 2 - 3 electrical surfaces Resistance DIN 53482: 5.5.101211 <Crischstropfestigkeit DIN 53480: level KA 3b Example 2: 7 liters of diglycol monomethyl ether, 630 g of melamine, 480 g of p-formaldehyde (Molar ratio 1: 3) are at a vacuum of 400 - 500 Torr to 120 - 1300C heated with stirring.

600 ml of water of reaction are distilled off.

The excess diglycol monomethyl ether is now at a vacuum of 10 torr (approx. 4 liters) distilled off at 1000C bath temperature. This recovered glycol monomethyl ether can be used again in further approaches.

2.1 kg of a 70% resin are obtained, determined by the content Stoving value 1 hour at 1200C, which can be mixed with water as required. The dilutability with the following solvents: toluene 1: n-butanol 1: 3 methanol 1: 00 The product obtained is with isopropyl alcohol to a concentration of approx. 45 X diluted. 2% p-toluenesulfonic acid (on solid resin related) added.

A cellulose carrier web weighing approx. 250 g / m2 is placed in this solution based on a resin content of approx. 25% Final paper weight, impregnated and dried at 1300C to a residual moisture content of 1%. In the Drying occurs simultaneously with the hardening of the resin in the film.

The melamine resin film is then given a paint coat of a acid-curing commercial paint, c. 30 g / m2, and is considered to be highly elastic Edge banding using a commercially available hot melt adhesive on the base of ethylene-vinyl acetate copolymers glued onto a chipboard edge.

Example 3: 1008 g melamine, 800 g p-formaldehyde (molar ratio 1 : 3), 8 liters of methylglycol are refluxed for 8 hours, then approx. 6 Liters of methyl glycol and water are distilled off.

3 kg of a 91% clear product are obtained, which is dissolved in water with can be mixed in any ratio. After diluting the solution with water to a concentration of 40%, a 2 80 g / m2 heavy printed wood pattern paper is impregnated in it. The resin content of the impregnated paper is approx. 38 or residual moisture content approx. 2 t.

The impregnated paper is made using a commercially available Polyvinylacetate glue cold-glued to a chipboard. The foil is left Stand over the edges of the chipboard and encased according to the thickness of the panel this in a second step by bending the film around the edge using from a suitable white glue.

The film is so elastic that there are no breaks when it is wrapped develop. The coated chipboard can then be treated with an acid-hardening Lacquer mark are provided.

Example 4: 126 g melamine, 180 g p-formaldehyde (molar ratio 1 : 6) 1.2 liters of methyl glycol are refluxed for t hours, then slowly 680 g of methyl glycol and water are distilled off.

730 g of an 80% strength resin are obtained, which is mixed with water and n-butanol can be diluted indefinitely.

70 parts of this resin, 30 parts of microcellulose, 4 parts of titanium dioxide, 1 part of zinc stearate is rolled out on a roller mill at 1100C to form a rolled sheet. After the rolled sheet has been granulated, it is processed in a standard rod form at 150 - 155 ° C, 250 kp / cm2 and 10 minutes of pressing time (or 8 minutes for the test for post-shrinkage) a molded body produced which has the following properties:, * flexural strength according to DIN 52362: 840 kp / cm2 tracking resistance according to DLN 53480: KA3c heat resistance according to Martens (DIN 53462): 1210C post-shrinkage according to DIN 53464: f impact strength according to DIN 53453: 7 kpcm / cm² Example 5: liters of methyl diglycol, 630 g of melamine, 480 g p-formaldehyde, molar ratio t: 3, are at a vacuum of 400-500 Torr heated to 120-1300C with stirring. 600 ml of water of reaction are distilled off.

The excess methyl diglycol is now at a vacuum of 10 torr (approx. 4 liters) distilled off at a bath temperature of 100 ° C.

This recovered methyl diglycol can be used again in further batches be used.

About 2.1 kg of a 70% resin are obtained, which can be mixed with water is miscible. In the resin solution diluted to 50% with water, 0.8 mm thick Veneers impregnated to a resin content of approx. 28 - 32% and to a residual moisture 7 - 8% dried in an air oven. 10 layers of these veneers are included 140 ° C, a pressure of 110 kp / cm2 and a time of 18 min.

pressed between high-gloss chrome-plated nickel sheets to form a plate. The following values are measured on the plate: Flexural strength according to DIN 52362: 2237 kp / cm² impact strength according to DIN 53453: 21.2 kpcm / cm² water absorption after storage 96h 6oOC: 11.7% After alternating heat treatment of the plate of 3 x 20 hours each.

no cracks are obtained at 800C and cooling three times to 200C.

Claims (9)

P a t e n t a n s p r ü c h e 1. Process for the production of VOI1 moldings and surface coatings by pressing or pressing a thermosetting Combination of an aminoplast resin with a carrier or filler material, and possibly known additives such as pigments. Flow auxiliaries and lubricants or release agents at elevated temperature, characterized in that the aminoplast resin is an electro @ tireies, Etherified methylolaminotriazine is used, the statistical mean per Moles of the aminotriazine contain 1.3 to 2n methylol groups, where n is the number of Amino groups of the aminotriazine are at least 33% with a Glykolderiat of the general formula I R- (OCH2CH2) mOH (I) where R is an alkyl group with 1 to 4 Means carbon atoms and m stands for an integer from 1 to 4, are etherified. 2. The method according to claim 1), characterized in that as Aminoplast resin uses an electrolyte-free, weathered methylolaminotriazine that in statistical mean per .Mo 'of the aminotriazine contains 1.8 to 2n methylol groups. 3. The method according to claim 1, characterized in that mar as Aminoplast resin an electrolyte-free etherified methylolaminotriazine used, the statistical mean per mole of the aminotriazine 0.8n to 1.2n methylol groups contains. 4. The method according to claims 1 to 3, characterized in, that an electrolyte-free etherified methylolaminotriazine is used as the aminoplast resin used, in which the methylol groups are etherified to at least 50%. 5. The method according to claims 1 to 4, characterized in that that an electrolyte-free etherified methylolaminotriazine is used as the amiiloplast resin used, in which the methylol groups etherified with a glycol derivative of the formula I. are in which R is a methyl group. 6. The method according to claims 1 to 5, characterized in that that an electrolyte-free etherified methylolaminotriazine is used as the aminoplast resin used, in which the methylol groups etherified mit.einem glycol derivative of the formula I. in which m stands for the number 1 or 2. 7. The method according to claims 1 to 6, characterized in that that an electrolyte-free etherified methylolamnotriazine is used as the aminoplast resin used in which the methylol groups with a glycol derivative of the formula. I etherified in which R is a methyl group and m is the number 1 or 2. 8. The method according to claims 1 to 7, characterized in that that the aminoplast resin is an electrolyte-free etherified methylolaminotriazine used in which the aminotriazine is melamine. 9. The moldings produced according to claims 1 to 8 or surface-coated materials.