DE1006101B - Lacquers, especially cold-curing lacquers - Google Patents

Description

GERMAN

LIBRARY

DEE-GERMAN

PATENT OFFICE

Curable paint mixtures are proposed which contain on average more than one epoxy group Compounds, primary or secondary diamines, in which the amino groups on two optionally hydroaromatic radicals linked to one another via bridging atoms or atom groups and paint solvents exist.

It has now been found that excellently curable paint mixtures are obtained if one is used instead the primary or secondary diamines, in which the amino groups are optionally connected to two Bridging atoms or atom groups are linked hydroaromatic radicals, cycloaliphatic Diamines are used whose amino groups are bonded to the same cycloaliphatic radical. The amino groups can be in the o-, m- or p-position to one another. To these connections include, for example, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, and 1,3-diaminocyclohexane. The cyclic radicals can be substituted in the ring, for example by alkyl, aryl, aralkyl, Alkaryl or cycloalkyl radicals. Examples are the 1,2-diamino-4-ethylcyclohexane, 1,4-diamino-3,6-diethylcyclohexane and 1-cyclohexyl-3,4-diaminocyclohexane. The amino groups can also carry a substituent, that is to say they can be secondary. Such an amine is e.g. B. bis- (methylamino) -cyclohexane-l, 4. The claimed amines can be mixed with aliphatic amines and polyamines, ζ. B. with diethylenetriamine, and with primary or secondary diamines, in which the amino groups are optionally connected to two Bridge atoms or groups of atoms linked to one another are hydroaromatic radicals, use.

It is particularly advantageous to use equivalent amounts of the epoxy compounds and the diamines. In this case, there is one amine hydrogen atom for each epoxy group. The amine can, however also use in a slight excess or excess.

Both aromatic and aliphatic glycidyl ethers are used to produce the claimed paint solutions suitable. The usual paint solvents are suitable as solvents, e.g. B. ketones, Esters, alcohols, glycol ethers and hydrocarbons, optionally mixed with one another. Further be often a few percent of a leveling agent, based on epoxy compounds, added, for example Urea-formaldehyde resins, phenol-formaldehyde resins, high molecular weight amines and their Salts or quaternary ammonium compounds.

The mixtures according to the invention of polyglycid ethers and diamines can also be used as solvent-free Varnishes are used (see. Example 1).

Lacquers, especially cold-curing lacquers

Applicant:

Aniline & Soda Factory in Baden
Aktiengesellschaft, Ludwigshafen / Rhein

Dipl.-Ing. Oskar Lissner, Mannheim,

and Dr. Heinrich Scholz, Ludwigshafen / Rhine,

have been named as inventors

The paint solutions absorb pigments, dyes and fillers well. They can be stored for much longer than when using corresponding amounts of other amines. Still, they dry with these Paint solutions produced coatings very quickly at normal temperature and are extremely water-resistant. The lacquer solutions can be stored or heated for some time after the hardener has been added, until pre-hardening has taken place, but this is not necessary to avoid the blooming effect. The lacquer solutions can be used at room temperature or at elevated temperature, e.g. B. at 120 up to 180 °, can be dried. Clear and haze-free films are obtained even with immediate processing. The coatings are particularly bright, shiny and lightfast. They are hard and yet elastic.

The parts mentioned in the examples are parts by weight.

example 1

100 parts of a liquid epoxy resin prepared from 1 mole of butanetriol and 3 moles of epichlorohydrin with an epoxy value of 0.36 (the epoxy value indicates how many epoxy groups are present in 100 g / mole of epoxy resin are) are mixed with 12 parts of 1,4-diaminocyclohexane. The mix is up to about Stable for 2 hours at 20 °. After applying to sheet metal and drying at room temperature the coating is completely cured after about 7 hours. A pore-free, high-gloss, hard yet elastic coating, even if you only apply the solvent-free paint once applies.

If, instead of the 1,4-diaminocyclohexane, equivalent amounts of an aliphatic polyamine are used, z. B. ethylenediamine or dipropylenetriamine,

609 868/401

so the hardening reaction proceeds at room temperature undesirably quickly, so that charring of the mixture can only be avoided by cooling.

Example 12 -

A 40% solution of an epoxy resin is made from 1 mol of 4,4'-dioxydiphenylpropane and 2 mol Epichlorohydrin with an epoxy value of 0.20 in a mixture of equal parts of methyl isobutyl ketone, Ethylene glycol monoethyl ether and toluene. 100 parts of this solution are mixed with 2 parts of the 6O% oigen butanolic Solution of a non-plasticized urea formaldehyde resin and then with 2, 4 parts 1, 2-diaminocyclohexane mixed. The lacquer solution is spread on a glass plate and one is obtained Coating that is tack-free within 2/2 hours at 20 ° dries and is fully cured after 10 hours. The coating is high-gloss, completely free of haze and shows no cloudiness after soaking in water. The paint solution can be kept for about 14 days at 20 °. If, instead of 1,2-diaminocyclohexane, the equivalent amount of an aliphatic polyamine is used, the paint solution can only be kept for about 2 to 3 days. The coatings require drying and curing then for a longer period of time, and the hardened coatings are somewhat more cloudy (blooming effect) and more sensitive to water.

Claims (1)

Claim Lacquers, especially cold-curing lacquers, based on an average of more than one epoxy group Compounds containing in the molecule with the addition of polyamines as curing agents, thereby characterized in that primary or secondary cycloaliphatic diamines are used as hardeners whose amino groups are on the same cycloaliphatic radical. © 609 868/401 4.57