DEP0014339DA - - Google Patents

Description

—_2-— Be stc 11-Fr. 1194-2 / 53

The half-anides mentioned above can be combined with the amino compounds and dom formaldehyde condense, and thereby become thermosetting Receive aminoplasts that no longer need a hardening accelerator, thus can be referred to as self-retaining aminoplasts. Up to now it was necessary to test the known aminoplasts hardening knitting laboratory to be added in order to obtain perfectly cured products. According to the invention, a resin is obtained which has the Property to harden, contains in itself. Thus, one can speak of "self-hardening" resins. This invention is of great importance practical importance, since one with the prepared according to the invention Resins uniform and completely hardened o Pressings without bubbles and without discoloration are obtained. Die, resin syrups and molding compounds according to the invention can be left without for a long time Store change. The thermosetting aminoplasts used hitherto require a mostly acidic hardening accelerator for their hardening, and those with the addition of such a hardening accelerator The masses produced had to be processed after production.

For the production of the synthetic resins according to the invention, the aldehyde component used is preferably formaldehyde or substances which develop formaldehyde, such as, for example, paraformaldehyde, hexamethylenetetramine. The amino compounds that can be used are those that react with aldehydes _7, for example, urea, substituting ureas, substances with a urea-like character, such as guanidine, dicyandiamide, aninotriazines »

For the manufacture of new synthetic resins according to the invention expedient preconiation products at normal or elevated temperatures and in the absence or presence of an acidic or preferably made alkaline catalyst. The best results are obtained when the condensation reactions takes place between the starting components in the presence of a primary and secondary condensation catalyst. Products with optima] The shelf life is maintained when used as the primary catalyst nitrogenous, basic, tertiary compounds, the do not react with aldehydes, e.g. tertiary amines, or nitrogen-containing basic compounds that react with aldehydes, e.g. ammonia primary or secondary amines can be used. As a secondary catalyst, generally in smaller quantities used as the primary catalyst are fixed alkalis, ZtBt carbonates, cyanides, hydroxides of the alkali metals.

For the production of the initial condensation products, different ways can be tread; For example, all participants in the reaction are mixed first and the condensation is carried out in the presence or absence of additional substances such as catalysts, fillers, solvents. An initial condensation product of urea and aldehyde can also be produced first, which is condensed to end'-e after the addition of the oxalic acid halide Or the half-amides of oxalic acid are first condensed with aldehyde, and the product obtained in this way is converted into a urea-aldehyde precondensation product and condensed further Condensation is added. Dl ^ ^r ~ - "- ^ obicn can be at Eaumtemperatu;

3 Bestoll no. 11942/53

or increased temperature, normal, increased or decreased Perform pressure.

The wipe condensation products can be concentrated or diluted, by removing or adding liquid solvents. The liquid products can be used for the production of surface coatings, paints, lacquers, enamels and for the production of laminates. The gel-like products can be dried and used granulate and then form unfilled, thermosetting resins. Liquid, more viscous condensation products can be ^r ^, c gosson directly.

Example 1 parts

Melanin 315, ο

Urea 15o, o

Aqueous formaldehyde solution (about 37.1% HCHO) 1ooo, o

üässr. Ammonia (28% NH?) 3o, o

Sodium hydroxide in 30 parts of water o, 6

K ic nyl oxanic acid 1.9

The action participants, with the exception of phenyloxamic acid, will be mixed; and heated on the reflux condenser for 15 minutes. Then the Phenyloxamic acid added and brought to the boil again, hot resin syrup will flake it and η it 4-75 parts alpha-cellulose 4- part zinc carat mixed, the wet mass 1 1/2 hours dried at 75 and then 2 minutes at 13ο under a pressure of 40 kg / cm2. The compacts can be undamaged besides the still hot form en.tferii.on, you are good; through hardened, have excellent surface finish and water resistance. Without phenyloxamic acid, insufficiently hardened compacts are obtained which disintegrate in water.

Example 2 parts

-Io la " ¹ , in

Thiourea

r / aqueous formaldehyde solution (approx "Jässr. Aunoniak (28% NH,) Sodium hydroxide in 30 parts Phenyloxamic acid

The resin syrup is produced in the same way as in Example 1 and processed into a resin composition with 490 parts of alpha cellulose. The compacts are well cured, have good surface finish and ^w asserbeständigkeit. The hardening properties of the hemi-anides have a particularly favorable effect if urea or thiourea is completely or partially replaced by an aninotriazine, for example bielanine. For best results, the amount of lainotriazine should be at least 25% of the molar amount of urea, thiourea, dicyandiamide, etc.

315, o 19o, o 37.1% HCHO) 1ooo, o 3o, o i / acser 0.6 1.95

The limits of urea, aldehyde, and hemi-anide can be broad Limits vary · Good results are obtained when using 1 3/4 · - 6% of aldehyde per mole of urea substance of the hemiamide

__- 4 Be stc H no. 11942/53

sweckLiessig o, oo1 - o, 2 moles per mole of urea substance are used. Colorants, plasticizers, lubricants, opacifiers and fillers of all kinds are used in a known manner. Curing takes place preferably at temperature:.! from 120 18c and printing of preferably 14o - 28o kg / cm ^ »

The synthetic resins according to the invention are for the most diverse Purposes applicable, 3.P. for molding compounds, lacquers, for the production of layers bofion, for the production of arc-extinguishing pipes that a licit-arc-quenching gas in the heat of the electric arc develop for wire enamels.

The cured articles have excellent warning and cup resistance and high dielectric strength, especially when an aminotriazine is used as one of the reactants. Such products are particularly suitable for electrical isolation purposes.

Claims (2)

■ öatuc des Pateiitblattec: December 17, 1953 order no. 1T942 / 52 file number ρ 14 339 D. 39c. 5. Priority: Inventor: Gaetano FD ¹ AIeIIo, enough: 1.10.48 Mt. Lebanon, Pa. Known L-ciaacht: 17.12.53 (V.St.A.) Objection until: 17. 4. ^ 4 withdrawn / predicts:
DP. front: Process for the production of thermosetting aminoplasts « Patent claims: I. A process for the production of thermosetting aminoplasts which can be used in particular for electrotechnical purposes, characterized in that the amino compounds are condensed together with one or more aldehydes in the presence of halides of oxalic acid. 2.Verfahren according to claim 1, characterized in that the initial reaction in the presence of alkaline Kojadensationskatalysatoren is carried out. 3i - rindung relates to the preparation of thermosetting Aninopla_ste _t corresponding to the general Pornel organic substances iooH are modified. X in this formula denotes an anide radical or Thioanide residue with at least one hydrogen atom directly attached to aerosol nitrogen. Examples of such residues can be given by the general formulas -CON and -CSN be represented in which R is hydrogen or an alkyl, aryl, aralkyl, alkaryl, acyl, naphthyl, or hetero cyclic radical is hydrocyclischer or derivatives thereof. In particular, these are the semi-alaids of oxalic acid, for example oxamic acid OC) C) V! or fien ^ / loxanic acid 0OH 2