DE2163143B2 - Aqueous dispersion of a non-gelled epoxy resin that is dispersible in water - Google Patents

Description

The invention relates to aqueous dispersions of ungelled water-dispersible epoxy resins and their use for the electrical coating of electrically conductive substrates.

Although electrical deposition has long been known, it has been used as a method of making Coatings only recently gained technical importance. Side by side with the intensifying Use of this process has led to the development of certain preparations with which satisfactory Coatings are obtained. Even if many preparations can be deposited electrically, so preserve one with most coating preparations, when applied by electrodeposition, none Coatings that meet industrial requirements. Moreover, the electrical deposition is of many Coating compositions, even if they otherwise lead to good results, often with disadvantages like that Formation of non-uniform coatings or poor dispersion. They also have Coatings obtained by this process in most cases have defects with regard to certain defects

ίο properties that are suitable for their use for purposes are essential for which the electrical deposition is otherwise suitable. Above all, it is difficult to do so Properties such as good corrosion resistance and good resistance to alkalis, with resins,

[5 as it is commonly used in electrodeposition used to achieve. This is especially true of those used in electrical deposition Preparations of the conventional type which contain polycarboxylic acid resins which have been made soluble with a base. These are deposited on the anode and, because of their acidic character, tend to be sensitive to corrosive ones Attacks of the usual kind, for example by salts or alkalis. Lots of electrical on the anode Deposited coatings suffer discoloration or staining as a result of metal ions on the anode go into solution.

Epoxy resins, which have excellent corrosion resistance and other valuable properties, are among the most suitable substances for many purposes. They are used in many coatings; however, they are not found in water-dispersible electrodeposition formulations used because they are insufficient under the conditions of this deposition process Let the measure disperse in water. There are also esterified and also amino-containing epoxy resins used, but these behave similarly to the polycarboxylic acid resins, and if they also behave towards Polycarboxylic acid resins have many advantages, but they also have many disadvantages.

The object of this invention is therefore an improved dispersion of an epoxy resin which is used for electrical Deposition is suitable.

According to the invention, this object is achieved by an aqueous dispersion of a non-gelled water-dispersible epoxy resin, which may optionally contain solvents, which is characterized in that it consists of 1 to 25 percent by weight of an epoxy resin with at least one epoxy group in the molecule and a content of chemically bound nitrogen of at least 0.05% in the form of a salt of a quaternary ammonium base and an acid with a dissociation constant of greater than 1 · ΙΟ- ⁵ , 0.01 to 8 percent by weight boron in the form of boric acid and optionally other common resinous materials, plasticizers , coupling solvents, pigments, antioxidants, surface treatment agents and wetting agents.

Aqueous dispersions of this type are outstandingly suitable as coating compositions. You can follow them apply conventional methods such as dipping or brushing. You are suitable but especially excellent for electrodeposition application.

The electrodeposition coatings obtained with dispersions of this type are all inexpensive Properties of the previously known electrical

depositable resins obtained coatings and, moreover, other excellent advantages and Properties. These include excellent resistance to salt spray, alkalis and the like corrosive substances, even on unprimed metals or in the absence of corrosion inhibitors Pigments as well as the resistance to staining or discoloration, as is often the case with electrical power shows stored coatings of anionic resins. • lir. Another advantage of the dispersions after Invention is that they have a significantly higher spread in electrical deposition than Similar preparations, for example those known from US Pat. No. 3,301,804.

In the dispersions according to the invention, epoxy resins are either the sole resin component or the main ingredient among other resinous or film-forming materials.

The resins contained in the dispersions according to the invention are ungelled, water-dispersible epoxy resins which contain in their molecule at least one 1,2-epoxy group, chemically bound quaternary ammonium salts and optionally oxalkylene groups, the ammonium salts being salts of an acid which has a dissociation constant that is greater than 1 ■ 10 ~ ⁵ . An acid of this kind can be chosen from the series of organic and inorganic acids. Preference is given to using a carboxylic acid and, as such, currently preferably lactic acid.

The concentration of the epoxy resin in the dispersion depends on the conditions of use. In the Usually, however, water is the main component of the dispersion and the concentration of the epoxy resin it is is 1 to 25 percent by weight of the dispersion and the boric acid content is 0.01 to 8 percent by weight Boron in the form of boric acid. The term "dispersion" used here also includes colloidal aqueous solutions the epoxy resins.

The epoxy resin occurring in the dispersions according to the invention preferably contains from 0.05 to 16 percent by weight nitrogen, of which at least 1%, expediently 20%, more expediently 50% and preferred essentially all of the chemically bound groups are quaternary ammonium salts, while the remainder of the nitrogen is amino nitrogen.

Any desired epoxy resins can be used to prepare the epoxy resins contained in the dispersions according to the invention monomeric or polymeric compounds with a 1,2-epoxy equivalent of more than 1.0, i.e. in which the The average number of 1,2-epoxy groups in the molecule is greater than 1, or mixtures of such compounds use. It is preferred to use a resinous epoxy compound; H. a polyepoxide that contains more than one epoxy group in the molecule. The polyepoxide can be any known epoxide. pre-condition for its usefulness is that it must contain epoxy groups in such an amount that in the Product after the oxyalkylation, some epoxy groups for the reaction described below with the Amino compound are present. Epoxides of this type are for example in US Patents 24 67 171, 26 15 007, 27 16 123, 30 30 336, 30 53 855 and 30 75 999 mentioned. A particularly suitable class of polyepoxides are the polyglycidyl ethers of polyphenols, for example of bisphenol A. You can use these ethers prepare, for example, that a polyphenol with epichlorohydrin or dichlorohydrin in the presence of an alkali etherified. As a phenolic compound you can here

Bis (4-hydroxyphenyl) -2,2-propane,

3,4'-dihydroxybenzophenone,

Bis (4-hydroxyphenyl) -1,1 -ethane,

Bis (4-hydroxyphenyl) -l, l-isobutane,

Bis- (4-hydroxy-tert-butylphenyl) -2,2-propane,

Bis (2-hydroxynaphthyl) methane and

1,5-dihydroxynaphthalene

use. Another class of very suitable polyepoxides can be found in the same way Manufacture novolak resins or similar polyphenol resins.

Other particularly suitable epoxy-containing compounds and resins are selected from 1,1-methylene-bis (5-substituted Hydrantoin) produced epoxy resins, see US-PS 33 91 097, and heterocyclic N.N'-diglycidyl compounds, see U.S. Patent 3,503,979; also nitrogen-containing diepoxides, see US Pat. No. 3,365,471; Aminoepoxyphosphonates, see GB-PS 11 72 916 and 1,3,5-triglycidyl isocyanurates.

The corresponding polyglycidyl ethers of polyhydric alcohols are also suitable. As polyhydric alcohols be in this context

Ethylene glycol, diethylene glycol, triethylene glycol,

1,2-propylene glycol, 1,4-butylene glycol,

1,5-pentanediol, 1,2,6-hexanetriol, glycerin and

Bis (4-hydroxycyclohexyl) 2,2-propane
called.

It is also possible to use polyglycidyl esters of polycarboxylic acids. You provide this by implementing of epichlorohydrin or a similar epoxy compound with an aliphatic or aromatic one Polycarboxylic acid, for example oxalic acid, succinic acid, glutaric acid, terephthalic acid, 2,6-naphthyl dicarboxylic acid and dimerized linolenic acid. Examples of such esters are diglycidyl adipate and the Diglycidyl phthalate.

In addition, there are also those produced by the epoxidation of olefinically unsaturated alicyclic compounds Suitable for polyepoxides. These include diepoxides, some of which are a monoepoxide or several monoepoxides contain. These polyepoxides are non-phenolic. They are obtained by using alicyclic olefins, for example with oxygen in the presence of selected metal catalysts with perbenzoic acid, with acetaldehyde monoperacetate or epoxidized with peracetic acid. These polyepoxides include the epoxyalicyclic ethers and Esters known from the literature.

Another class of polyepoxides which is preferably used in many cases comprises such Polyepoxides that contain oxalkylene groups in the epoxy molecule. The oxalkylene groups of these compounds are usually groups of the general formula

in which R is hydrogen or alkyl, preferably a lower alkyl having, for example, 1 to 6 carbon atoms, and in most cases m is a number from 1 to 4 and η is a number from 2 to 50. These groups can be attached to the main molecular chain of the polyepoxide or be part of this chain. The amount of oxalkylene groups in the polyepoxide depends on a number of factors, such as the

Chain length of the oxalkylene group, the type of epoxide and the desired degree of water solubility.

A number of polyepoxides containing oxalkylene groups are prepared by reacting some of the epoxy groups of a polyepoxide, for example one of the epoxy resins mentioned, with a monohydric alcohol containing oxyalkylene groups. Monohydric alcohols of this type are conveniently prepared by oxyalkylating an alcohol, such as methanol or ethanol, with an alkylene oxide. Ethylene oxide, 1,2-propylene oxide and 1,2-butylene oxide are particularly suitable as alkylene oxides for this purpose. Also suitable as monohydric alcohols are, for example, the commercially available monoalkyl ethers of alkylene and polyalkylene glycols. The reaction of the monohydric alcohol with the polyepoxide is generally carried out in the presence of a catalyst. The catalyst used is formic acid, dimethylmethanolamine, diethylethanolamine, N ₁ N-dimethylbenzylamine and, in some cases, tin dichloride.

Oxalkylene group-containing polyepoxides of a similar type can be prepared by the Epoxy resin oxalkylated in another way, for example by a direct reaction with an alkylene oxide.

The one used for the preparation of the above-mentioned oxalkylene group-containing epoxy compounds Polyepoxide should contain epoxide groups in such an amount that the number of these groups following the Oxalkylation still present in the product averages greater than 1.0 per molecule. If that Epoxy resin contains oxalkylene groups, their proportion makes up 1.0 to 90 percent by weight or more.

The epoxy resins contained in the dispersions according to the invention can be prepared in that one containing the epoxy compound with an amino salt to a quaternary ammonium group Resin converts.

As examples of salts are salts of ammonia, primary, secondary and tertiary amines, preferably tertiary amines and an acid having a dissociation constant greater than 1 called -10-. ⁵ The preferred tertiary amines react with the epoxy compounds directly to form a quaternary ammonium compound, whereas the other amino compounds and the epoxy compound initially form tertiary amines, which are then reacted further with excess epoxy compound. As examples of acids having a dissociation constant greater than 1 × 10 ^-5 may be mentioned lactic acid, acetic acid, propionic acid, butyric acid, hydrochloric acid, phosphoric acid and sulfuric acid. Of these acids, lactic acid is preferably used at present. The amines can be unsubstituted amines or amines substituted with non-reactive substituents, such as halogen or hydroxylamines. Examples of such amines are dimethylethanolamine, salts of boric acid, lactic acid, propionic acid, butyric acid, hydrochloric acid, phosphoric acid and sulfuric acid or similar salts of triethylamine, diethylethanolamine, trimethylamine, diethylamine, dipropylamine and 1, -amino-2-propanol.

Within the broad class of amino compounds, the salts that may be mentioned as a special class are those of Amines with a secondary or tertiary amino group or more such groups and with one Hydroxyl group are derived.

In most cases the hydroxylamine used corresponds to the general formula

R,

NR ₁ -OH

ίο In this formula, Ri and R2 are preferably methyl, Ethyl or other lower alkyl groups. In principle, except for the groups mentioned, you can do any mean organic group which does not adversely affect the desired reaction. As examples are Benzyl and alkoxyalkyl called. In addition, Ri can also be hydrogen. The nature of the groups is less important here than the presence of a secondary or tertiary amino nitrogen atom. Therefore can also higher alkyl, aryl, alkaryl or aralkyl groups or substituted groups of these Kind of be present. R3 in the formula denotes a divalent organic group, for example one Alkylene or substituted alkylene group, such as oxalkylene or poly (oxalkylene) or, less expediently, an arylene, alkarylene, or substituted arylene group. R3 can also be an unsaturated group, for example be an alkenylene group. As examples are

-CH = CH-

and

-CH = C-

called. Rj also denotes cyclic and aromatic Groups. Suitable amines in the latter case are those with the formula

CH ₂ N

R,

R,

in which Ri and R2 have the abovementioned meaning and η is an integer from 1 to 3. Dialkanolamines of the general formula RiN (R3OH) 2 and trialkanolamines of the general formula N (R3OH) 3 are also suitable. As an example of the above definitions corresponding and particularly suitable amines may be
Dimethylethanolamine, dimethylpropanolamine,

Dimethylisopropanolamine, dimethylbutanolamine, diethylethanolamine, ethylethanolamine,
Methylethanolamine, N-benzylethanolamine,
Diethanolamine, triethanolamine,
Dimethylaminoethylphenol,

Tris (dimethylaminomethyl) phenol,
2- [2- (dimethylamino) ethoxy] ethanol,
1 - [I - (dimethylamino) -2-propoxy] -2-propanol,
2- (2-2- (Dimethylamino) ethoxy] ethoxy) ethanol,
l- [2- (dimethylamino) ethoxy] -2-propanol and

1- (1- [Dimethylamino) -2-propoxy] -2-propoxy) -2-propanol
called.

Within the broad class of amino compounds, amines may also be mentioned in particular, the one secondary or tertiary amino group or more such groups and at least one terminal group Contain carboxyl group and as such, d. H. without being converted into a salt form, can be used. As a rule, such a carboxylamine corresponds to the general formula

NR ₃ COOH

In this formula, Ri and R2 preferably stand for Methyl, ethyl or other lower alkyl group. They can basically mean any organic group, which does not adversely affect the desired reaction. Examples are benzyl and alkoxyalkyl called. In addition, Ri can also be hydrogen. The type of group is less important than the presence of a secondary or tertiary amino nitrogen atom. Hence, higher Alkyl, aryl, alkaryl and aralkyl groups or substituted groups of this type may be present. R, denotes in the formula a divalent organic group, for example an alkylene or a substituted one Alkylene group, such as oxalkylene or poly (oxalkylene) or, but less conveniently, an arylene, Alkarylene or substituted arylene group. R3 can also be an unsaturated group, for example a Be alkenylene group.

You can prepare amines of this type by known processes, for example in the manner that an acid anhydride such as succinic anhydride, phthalic anhydride or maleic anhydride with an alkanolamine, such as dimethylethanolamine or methyldiethanolamine, is reacted. In the here received Amines contain the group designated by R3, ester groups. Other types of amines are made for example, by using alkylamines by the process of US Pat. No. 3,419,525 Alkyl acrylates or alkyl methacrylates, for example with methyl or ethyl acrylate or methyl or Ethyl methacrylate converts. In this case, the ester group is subsequently suitably converted into a by hydrolysis free carboxyl group converted. You can also use other types of amines to prepare amines Procedure work.

As can be seen, the groups labeled R3 can be of very different types. As examples be groups of formulas

- R'—
—R'OCOR'—

HRO) ₁₁ COR'-

called, in which R 'is an alkylene group, for example -CH2CH2- or

CH,
-CH ₁ CH -

or an alkenylene group denotes, for example, -CH = CH- and η denotes a number from 2 to or more. R 'can also denote cyclic or aromatic groups.

As examples of the definitions given above corresponding and particularly suitable Are amines

Ν, Ν-dimethylaminoethyl hydrogen maleate,

Ν, Ν-diethylaminoethyl hydrogen maleate,

Ν, Ν-dimethylaminoethyl hydrogen succinate,

Ν, Ν-dimethylaminoethyl hydrogen phthalate,

Ν, Ν-Dimethylaminoäthylhydrogenhexahydro-

phthalate,

2- (2-dimethylaminoethoxy) ethyl hydrogen maleate,

l-methyl-2- (2-dimethylaminoethoxy) ethyl

hydrogen maleate,

2- (2-dimethylaminoethoxy) ethyl hydrogen

succinate,

l, l-dimethyl-2- (2-dimethylaminoethoxy) ethyl

hydrogen succinate,

2- [2- (2-dimethylaminoethoxy) ethoxy] ethyl

hydrogen maleate,

beta (dimethylamino) propionic acid,

beta (dimethylamino) isobutyric acid,

beta (dimethylamino) ethyl hydrogen maleate,

beta (diethylamino) propionic acid,

2- (methylamino) ethyl hydrogen succinate,

3- (ethylamino) propyl hydrogen maleate,

2 [2- (dimethylamino) ethoxy] ethyl hydrogen

adipate,

Ν, Ν-dimethylaminoethyl hydrogen azelate,

Di- (N, N-dimethylaminoethyl) hydrogen

tricaballylat,

Ν, Ν-dimethylaminoethyl hydrogen itaconate,

1 - (1 - [1 (dimethylamino) -2-propoxy] -2-propoxy) -

2-propyl hydrogen maleate and

2- [2- (2- [2- (dimethylamino) ethoxy] ethoxy) -

ethoxy] ethyl hydrogen succinate

called.

It should be noted that a carboxylamine as such, i.e. H. without it in an additional salt form because the amino acid is a zwitterion that forms an inner salt.

The boric acid contained in the dispersions according to the invention can be added to the dispersions as such or in the form of compounds which hydrolyze to boric acid. The presence of the boric acid in the dispersions is beneficial in that it catalyzes the curing of a film made therefrom, enables lower curing temperatures and / or results in harder films. The boric acid can also be introduced into the dispersion by a special embodiment for the preparation of the nitrogen-containing epoxy compounds by first reacting epoxy compounds with a boric acid ester containing amino groups and / or a tertiary amine salt of boric acid and then reacting an acid with a dissociation constant of greater than 1 ■ ΙΟ- ⁵ adds.

Any desired triorganoborate, for example, can be used as the boron compound for the preparation of the reaction products use in which at least one of the organic groups is replaced by an amino group is. According to their structure, such esters are esters of boric acid or a dehydrated boric acid, for example metaboric acid and tetraboric acid, although they are not necessarily composed of these acids must be made. In most cases

609 525/473

the boron esters used correspond to one of the formulas

RO-B

OR

OR

/ \
RO - BR

in which R denotes the same or different organic radicals. R can be practically any organic Be remainder, for example a hydrocarbon radical or substituted hydrocarbon radical, which is not more than Contains 20 carbon atoms, preferably not more than 8 carbon atoms. The preferred used Esters contain alkyl radicals or polyoxalkyl radicals. At least one of these organic residues contains one Amino group, d. H. a group of the formula

- N

in which Ri and R2 represent hydrogen or, preferably, for Methyl, ethyl or another lower alkyl radical, but also be any other organic radical can, provided that this does not adversely affect the desired reaction. It depends less on the nature of the radicals used in each case rather than the presence of the nitrogen atom of an amino group. For this reason, higher alkyl, aryl, alkaryl radicals and substituted radicals of this type can be present be. If both Ri and R2 can be hydrogen, i. H. the amino group is a primary one Is amino group, one preferably uses at least one alkyl radical or another organic radical, so that the amino group is a secondary or tertiary amino group.

The boric acid esters or boron esters used with preference correspond to the formula

R,

X-O-Rj-N

in which X is the formula

/ \
R ₄ B-

R ₅ -O

R ₁ , -

B-

Has. In these formulas, Ri and R2 have the above Meaning and R3 and R4 stand for divalent organic radicals, for example alkylene radicals or:

substituted alkylene radicals, such as oxalkylene or poly (oxylkylene) radicals, or, less desirable, arylene, Alkarylene or substituted arylene radicals and Rs and Ri stand for alkyl radicals, substituted alkyl, aryl, alkaryl radicals or another radical consisting of a any monohydric alcohol can be derived by removing the hydroxyl group. Rs and Rd can be the same or different.

Examples of boric acid esters of the class mentioned include:

2- (beta-dimethylaminoisopropoxy) -4,5-dimethyl-

K3,2-dioxiborolane,

2- (beta-diethylaminoethoxy) -4,4,6-trimethyl-1,3,2-dioxaborinane,

2- (beta-dimethylaminoethoxy) -4,4,6-trimethyl-

1,3,2-dioxaborinane,

2- (beta-diisopropylaminoethoxy) -

1,3,2-dioxaborolane,
2- (beta-dibutylaminoethoxy) -4-methyl-

1,3,2-dioxaborinane,

2- (beta-diethylaminoethoxy) -1,3.2-dioxaborinane,

2- (gamma-aminopropoxy) -4-methyl-

1,3,2-dioxaborinane,
2- (beta-methylaminoethoxy) -4,4,6-trimethyl-

t, 3,2-dioxaborinane,

2- (beta-ethylaminoethoxy) -l, 3,6-trioxa-

2-boracyclooctane,

2- (gamma-dimethylaminopropoxy) -1,3,6,9-tetraoxa-2-boracycloundecane,

? - (Beta-dimethylaminoethoxy) -4- (4-hydroxy-

butyl) -l, 3,2-dioxaborolane and

the reaction product from (CFb ^ NCHhCFhOH,

Lactic acid, B2Cb and neopentyl glycol.
A number of boric acid esters containing amino groups are known. Many of them are described in US Pat. No. 3,301,804 and 3,257,442, for example. They can be prepared by reacting one mole of boric acid (or an equivalent amount of boron oxide) with at least three moles of alcohol, at least one mole of the alcohol being an amino-substituted alcohol. The reaction is usually carried out in such a way that the starting materials are boiled under reflux and the water formed is removed.
To implement the amino salts with the epoxy compound is added, the two components at a moderately elevated temperature, for example at a temperature between 70 to 110 ⁰ C, together. If a tertiary amine is used, according to a less common embodiment, the amine can be added to the epoxy compound and the acid used to prepare the desired salt can be added to the mixture of the two, if appropriate not until the solubilization stage. The use of a solvent is not necessary, although a solvent is often used to better control the reaction. As solvents are aromatic hydrocarbons and monoalkyl ethers of the ethylene

glycols suitable. The amount ratio between the amino salt and the epoxy compound can vary. The optimal proportion is determined by the type of raw materials used in each case. In the Typically 1 part by weight to 50 parts by weight of the salt is used per 100 parts by weight of the epoxy compound. The amount ratio is usually based on the amount of nitrogen, which is normally between Is 0.05 to about 16 percent by weight of the total weight of the amino salt and the epoxy compound. There the amino salt with the epoxy groups of the epoxy resin to form an epoxy group-containing resin reacts, the stoichiometric amount of the amine used must be smaller than the stoichiometric Equivalent of epoxy groups present, so that the resin has an average of one epoxy group per molecule contains.

The starting materials, their proportions and the reaction conditions should be selected according to guidelines which prevent the product from gelling and are known to the person skilled in the art. For example, should extremely severe reaction conditions are not used. Similarly, should connections with reactive substituents cannot be used together with epoxy compounds with which these Substituents could react disadvantageously under the given conditions.

The epoxy resin contained in the dispersions according to the invention can to a certain extent to be connected. However, it must be soluble in certain organic solvents and curable with heat stay. It is essential because of its epoxy content and because of its content of chemically bound quaternaries Marked with ammonium groups.

When one at least partially employs the salt of an acid in the manufacture of the resin with a dissociation constant of greater than 1 x 10 ^-5, it takes the product to produce a suitable aqueous add electrically depositable preparation no solubilizing agent, although a desired Can use acid or an acidic agent as a solubilizing agent. If one of the type described above boric acid salts and boron compounds used in the absence of a salt of an acid having a dissociation constant of greater than 1 x 10 ~ ⁵ for the preparation of the resin, to dispersions of the inventive type can be prepared by the fact that adding such an acid, whereby the stronger acid replaces the boron compound in the resin and the boron compound, which forms an essentially undissociated boric acid, remains in the aqueous medium and is at least partially deposited with the resin.

The existing as a partner of the quaternary ammonium groups in the novel dispersions acids having a dissociation constant greater than 1 x 10 ~ ^5, have a stabilizing effect on the resin, since the epoxy resin tends to continue to polymerize upon storage under strongly alkaline conditions. In some, the acid also helps the resin to dissolve to a greater extent. It is also useful to electrically deposit the coatings from an acidic or only slightly basic solution, for example at a pH between 3 and 8.5, and the addition of an acid is often useful in order to set the desired pH.

If a carboxylamine is used to prepare the epoxy resin, the resin contains a zwitterion or internal salt formed by the reaction between the quaternary group formed and the carboxyl group present. Here, the carboxyl group must have a dissociation constant containing 1 x 10- ⁵ exceeds. The resin obtained is an inherently soluble product, ie it does not require the use of a special agent in order to make it soluble.

One sets the electrically depositable preparations

ίο appropriate a coupling solvent. Through this one can improve the appearance of electrodeposited films. As such solvents are Hydrocarbons, alcohols, esters, ethers and ketones are suitable. Preference is given to using monoalcohols, Glycols and polyols as well as ketones and ether alcohols. In particular, as coupling solvents Isopropanol, butanol, isophorone, 4-methoxy-4-methylpentanone-2, ethylene and propylene glycol, the monomethyl ether, Monoethyl ether and monobutyl ether of ethylene glycol, called 2-ethylhexanol, and ethylene glycol monohexyl ether. The presently preferred coupling solvent used is 2-ethylhexanol. The amount of solvent is not essential to the invention in the strict sense. Generally applies the dispersant in an amount of 0.1 to 40 percent by weight, preferably 0.5 to 25 percent by weight at.

Even if the dispersions according to the invention contain the ungelled epoxy resins with quaternary ammonium groups contained essentially as the only resin component, it is often used for improvement and to modify the appearance and / or the properties of the film obtained, the electrically depositable preparation non-reactive and reactive substances or resins such as Plasticizers, for example N-cyclohexyl-p-toluenesulfonamide, Ortho and paratoluene sulfonamide, N-ethyl ortho and N-ethyl paratoluene sulfonamide, aromatic and aliphatic polyether polyols, phenolic resins, for example phenolic resins containing allyl ethers, liquid Epoxy resins, tetrakis (2-hydroxypropyl) ethylenediamine and polycaprolactones; Triazine resins, for example Melamine resins and benzoguanamine resins, in particular their alkylated formaldehyde reaction products; Urea-formaldehyde resins, acrylic resins, polyesters containing hydroxyl and / or carboxyl groups and to add hydrocarbon resins.

In a preferred embodiment, the aqueous dispersion according to the invention contains something else resinous material as the non-gelled epoxy resin having quaternary ammonium groups, a melamine-formaldehyde resin or a urea formaldehyde halide in lesser amounts than the epoxy resin.

Other additives are esters, for example

Butyl benzyl phthalate, dioctyl phthalate,
Methyl phthalyl ethyl glycolate,
Butyl phthalyl butyl glycolate,
Cresyl diphenyl phosphate,
2-ethylhexyl diphenyl phosphate,

Polyethylene glycol 200 dibenzoate and polyester
and 2,2,4-trimethylpentanediol monoisobutyrate,
called.

In most cases, the resin preparations are also given a pigment and, if necessary, one Oxidation inhibitors, a surface treatment agent or a wetting agent, for example an im Commercially available diatomaceous earth containing a hydrocarbon oil and glycol-substituted acetylenes,

Sulfonates, sulfonated fatty acid amides and alkylphenoxy polyoxyalkylene alkanols to. The pigments used are those of the conventional type, for example iron oxides, lead oxides, strontium chromate, carbon black, titanium dioxide, Talc and barium sulfate, as well as color pigments such as cadmium yellow, cadmium red and chrome yellow.

When using the dispersions according to the invention for the electrical coating of electrically conductive These preparations are substrates with an electrically conductive anode and an electrically conductive anode Brought into contact with the cathode, the surface to be coated serving as the cathode. When the current flows between the anode and the cathode is deposited in contact with the bath containing the coating composition a firmly adhering film of the coating compound on the cathode.

The conditions under which the electrodeposition of the dispersions of the invention is carried out are generally the same as those employed in the electrodeposition of coatings of other types. The applied voltage can fluctuate widely, for example between 1 volt and several thousand volts. Usually the voltage is between 50 and 500 volts. The current density is usually between 1.0 A and 15 A per 929 cm ² . It tends to decrease during electrodeposition.

The resin freshly deposited on the cathode contains quaternary ammonium groups. The one that forms the salt Acid group migrates at least in part towards the anode. The electrodeposited resin contains also boron, which is bonded to the basic groups. The amount bound to the deposited film Bors grows depending on the number of basic groups in the concentration and the basicity of the basic groups with the concentration of boron in the bath until a degree of saturation is reached.

The film, even if it can be crosslinked to a certain extent, remains in certain organic Solvents soluble.

The dispersions according to the invention can be used for coating conductive substrates of any type. Metals such as steel, aluminum, copper and magnesium are particularly suitable as substrates. After the deposition, the coating is cured, usually at an elevated temperature. For this purpose it is normally exposed to a temperature between 121 and 260 ^° C. for 1 to 30 minutes. During curing, especially if it takes place at elevated temperature, at least a substantial part of the quaternary ammonium base is broken down into tertiary amino nitrogen. This contributes to the crosslinking of the coating, which after curing is infusible and insoluble. The presence of boric acid in the film increases the rate of crosslinking, decreases the temperatures at which a desired degree of hardness can be achieved in a commercially acceptable time, and results in coatings of greater hardness and corrosion resistance.

The epoxy groups can be determined by the well-known pyridine hydrochloride method. One A description of this method can be found, for example, on p. 242 of the »Quantitative Organic Analysis Via Functional Groups «by S i g g i a, published in 1963 by John Wiley & Sons, Inc., New York is.

The total amount of basic groups present in the polymer, i.e. H. of the quaternary groups and the amino groups can be determined on another resin sample. Usually the Resin sample neutral. If the resin is basic, the sample should be salted with a known amount of that in the resin any acid present can be neutralized. When the acid present in the resin as a salt is a weaker acid as HCl, the resin is titrated with HCl and with sodium hydroxide in an automatic titrator

ίο back-titrated. By titrating with HCl, the Total amount of base groups present while back-titrating with sodium hydroxide separating the quaternary groups from the amino groups. An analysis that is typical for this leads is carried out, for example, in the following manner: A 10 ml sample of approximately 10% solids is carried out Using the pipette, pour the sedimentation bath into 60 ml of tetrahydrofuran and then titrate the sample with 0.1 n-HCl up to the pH end point. The amount of acid consumed is the amount of quaternary groups and of amino groups equivalent. The sample is then titrated back with 0.1 η sodium hydroxide so that a The result is a titration curve with several end points. In this typical example, the first corresponds to the endpoint excess hydrochloric acid. When titrating with HCI, the second endpoint of neutralization corresponds to weak acid such as lactic acid and the amino hydrochloride. The volume difference between the two end points denote the volume of the standard base, that of the weak acid and thus is equivalent to the amine content of the sample.

When using a solvent such as propylene glycol, for example together with tetrahydrofuran, In order to keep the sample homogeneous, the boron present also has a titrating effect, since it interacts with the Propylene glycol forms an acid complex. Boric acid differs under the conditions mentioned from the weak acid, for example lactic acid, by a further neutral point in the pH titration curve. Depending on the strength of the amino group present, this either appears in that of the weak acid, for example lactic acid, or in the part of the titration curve corresponding to boric acid.

Excess weak acid or excess amine salt can be titrated with in the deposition bath alcoholic KOH can be determined. For this purpose, a 10 ml sample of approximately 10% solids is carried out containing deposition bath with a pipette in 60 ml of tetrahydrofuran and titrated potentiometrically with 0.1 η alcoholic KOH up to the first end point The amount of KOH consumed is the acid or the Amine salt equivalent in the sample. In the case of neutral preparations, titration with KOH determine the amount of amine present in the form of an amine salt, since the quaternary base is a strong one Base is not titrated.

If salts of strong acids are present in the sample, other methods must be used to reduce the acidity. and to determine amino groups as well as the quaternary groups. For example, if the resin is Hydrochloride of amines and quaternary hydrochloride groups, it can, for example, in a mixture of Glacial acetic acid and tetrahydrofuran are dispersed, whereupon the chloride with mercury-11-acetate a Forms a complex and the sample is titrated with perchloric acid to determine the total amount of amino groups and quaternary groups. One

titration carried out separately from alcoholic KOH gives the amount of amino groups present, since the quaternary groups are one of the alcoholic KOH have comparable strength.

Boron can be determined by the method described by R.S. Braman in Volume 7, on pp. 384 to 423 of the F. D. S η e 11 and Hilton at John Wiley & Sons, Inc., New York, published Encyclopedia of Industrial Chemical Analysis under the title Boron Determination «. The boron can be determined on a separated sample, for example by pipetting a 10 ml sample of a cationic deposition bath containing approximately 10% solids into 60 ml of distilled water introduces, the pH value by the addition of a sufficient amount of HCl lowers to about 4, the Sample using an automatic titration apparatus of the Metrohm Potentiograph E-436 or a similar device with 0.1 normal sodium hydroxide to the first neutral point of the pH titration curve back-titrate, make the solution acidic by adding 7 g of mannitol and titrating up to the second The neutral point of the pH titration curve. The amount of between the first and the second The end point of the base consumed is the measure of the number of moles of the boric acid complex formed in the sample.

In the preceding part of the description, a procedure is shown as an example, according to which the Resin of the dispersion according to the invention contained groups are determined according to amount and type can. In special cases, the process can be adapted to the resin to be analyzed. However, it is general spoken, in accordance with the description for the precise determination of the chemical contained in the resin Groups known a suitable method for each case.

Raw materials

Some of the starting materials used in the following examples are characterized below will.

Filling 741.6 parts of dimethylethanolamine, 714 parts of lactic acid and 300 parts of toluene in a with a thermometer, a stirrer, a distillation apparatus with reflux condenser and water trap and means for producing an inert gas cushion equipped reaction vessel and the reaction mixture heated for 4 hours at 105 to 110 ⁰ C. A total of 120 parts of water with a refractive index of η, 1.377 are collected. 245 parts of boric acid and 728 parts of neopentyl glycol are then added, and the reaction mixture is heated to 115 to 128 ° C. for about 4 hours, a further 205 parts of water of reaction having a refractive index of η ',' ■ 1.386 being collected. The reaction product contains 4.51% nitrogen. It has the likely formula

CH, O O — CH,

\ Il / \

N-CH, -CH, -O-C-CH-O-BC- (CH,) ₂

CH, CH, O -CH,

The product is referred to as boron compound A in the examples.

In several examples, oxalkylene group-containing monoalcohols are used which are obtained by reacting of ethanol with ethylene oxide in the presence of potassium hydroxide as a catalyst. In the In the following examples, "Monoalcohol A" is the reaction product of 5 moles of ethylene oxide and 1 mole of ethanol and "Mono alcohol B" is the reaction product of 10 moles of ethylene oxide and 1 mole of ethanol.

example 1

200 parts of an epoxy resin prepared from epichlorohydrin and bisphenol A and having an epoxy equivalent of 290 to 335 and a molecular weight of 580 to 670 are placed in a reaction vessel, 58.5 parts of monoalcohol A, 2.3 parts of tin (II) chloride and 28 are added parts of the dimethyl ether of diethylene glycol to the mixture and heated for 3 hours at 145 to 150 ⁰ C. this gives a modified by oxyalkylene groups epoxy compound having an epoxy equivalent of about 890. the mixture is heated 200 parts of the modified epoxy compound with stirring to 70 ⁰ C and are in the course of 13 parts of 2- (beta-dimethylaminoethoxy) -4-methyl-1,3,2-dioxaborinane were added in 21 minutes, the temperature increasing to 92.degree. After 5 minutes with stirring, 1719 parts of deionized water are then added together with formic acid in such an amount that the solution has a pH of 4.4. A colloidal dispersion containing 9.1% non-volatile solids is obtained. According to the analysis, the solid component contains quaternary ammonium groups and boron. The dispersion is deposited on steel electrodes under the following conditions:

Bath temperature 21, rC pH 4.4 Deposit time 180 seconds tension 225 volts Amperage 1.5 to 0.2 amps

Is obtained on the cathode of a firmly adhering coating for 20 minutes at 204.4 C ⁰ is cured. Analyzed in the wet state, the electrodeposited film shows a content of quaternary borate and quaternary hydroxide. When cured, the 0.0254 mm thick coating is hard, smooth and firmly adhering. It has excellent resistance to acetone, salt mist and alkalis.

Example 2

Example 1 is followed, but in contrast to this, an aluminum cathode is used. Man obtained the same results as in Example 1. The coating produced by deposition adheres firmly aluminum and has other satisfactory properties.

Example 3

In this example, the epoxy resin used is a reaction product of epichlorohydrin and bisphenol A having a molecular weight of 660 to 760 and an epoxy equivalent of 330 to 380.

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Are employed 445 parts of this resin with 125 parts monoalcohol B, 9.5 parts of 90% formic acid and 63 parts of diethylene glycol dimethyl ether for 8 hours at 150 to 155 ⁰ C in order. 16.3 parts of 2- (beta-dimethylaminoethoxy) -4-methyl-1,3,2-dioxaborinane are slowly added to 200 parts of the reaction product obtained, which has an epoxide equivalent of 737. A solution with a pH of 4.9 and a solids content of 38% is produced from this mixture by adding formic acid and water. This solution gives coatings with excellent properties by electrodeposition.

Example 4

Example 3 is followed, but in contrast to this, monoalcohol A is used and it is acidified Reaction product with acetic acid to a pH of 5.6. Coatings with are obtained from the solution equally good properties.

Example 5

An epoxy compound containing oxalkylene groups with an epoxy equivalent of 642 is prepared from 2500 parts of an epoxy resin of the type also used in Example 1, 441 parts of monoalcohol A and 49 parts of 90% formic acid. Are employed 325 parts of this modified epoxy compound at 7O ⁰ C in the course of 20 minutes a solution of 37.8 parts of boric ester prepared from 1 mole of boron oxide (B2O3), 2 moles of diethylene glycol and 2 moles of dimethylethanolamine to. This ester is probably 2- (beta-dimethylaminoethoxy) -1,3,6-trioxa-2-boracyclooctane of the formula

CHXl-U

BO-CHXH ₁ -N

/
CIIXH,

CH ₃

The solvent used is a mixture of 37.8 parts of butyl diethylene glycol acetate and 26.4 parts of isophorane. After completion of the Esterzugabe by which the temperature rises to 9O ⁰ C, the heating is continued for 2 minutes. 89.5 parts of deionized water and 50% strength aqueous acetic acid are then added in such an amount that a solution with a pH of 4.6 is formed. A coating is produced from the glycolic acid solution under the conditions mentioned in Example 1 by electrical deposition and cured for 20 minutes at 191 ^° C. A firmly adhering, hard, flexible and glossy coating is obtained which has high resistance to acetone.

Example 6

One uses one from 117 parts of the oxalkylene-modified Epoxy compound according to Example 5 and 55.5 parts of 1 mole of boron oxide, 2 moles of dimethylethanolamine and 4 mol of n-hexanol obtained boron ester and acidified this with Acetic acid to pH 4.5. By the borester

it is probably beta-dimethylaminoethyl-di-n-hexylborate from the formula

-O

15 O CIKCH, N.

CH,

CH ₁

From the reaction product acidified with acetic acid to a pH value of 4.5 one obtains clear ' aqueous solutions.

Example 7

The boron ester used in this example is prepared from 3 moles of 1,3-butanediol and 3 moles of 2-ethylaminoethanol and 1.5 moles of B2O3. This ester is probably 2- (beta-ethylaminoethoxy) -4-methyl-1,3,2-dioxaborinane from the formula

CH,

CH-O H

I \

CH, B-OCHXH ₁ -N-- CHXH,

CH, -O

An epoxy compound is also prepared by adding 2000 parts of an epoxy resin obtained by reacting epichlorohydrin and bisphenol A with the epoxy equivalent of 225 to 290 with 175 parts of polypropylene glycol (molecular weight 425), 150 parts of isophorone and 2.8 parts of dimethylbenzylamine 6 ^{; i} / 4 hours at 108 to 117 ⁰ C and the reaction product neutralized with 1.1 parts of 90% formic acid. It has an epoxy equivalent of 665 calculated on a 100% solids basis.

You then put 200 parts of the epoxy compound with 17.4 parts of the boron ester in the preceding Examples described way around and makes from the reaction product with water and 50% aqueous Formic acid produces a solution with a pH value of 4.45. It is made out of solution by electrical deposition Makes coatings and cures them at 196 ° C for 20 minutes. The coatings are smooth and shiny and durable against solvents.

Example 8

In this example, one of 2 moles!, 3-butanediol, 2 moles of 3-amino-1-propanol and 1 mole is used B2O3 manufactured boron ester from likely formula

CH,

CH-O

I \

CH, BO-CHXHXH ₇ NH,

1 ■ / "■ ■ -

CH ₂ -O

and one through the implementation of 2000 parts of the Epoxy resin according to Example 7.825 parts of Pclyäthyleneglycol (Molecular weight 400), 725 parts of isophorone and 14 parts of dimethylbenzylamine and puts the two components in the

Ratio of 70 parts of the epoxy compound (80%

Solids content) around. The implementation example 9 is brought

duct by adding water and formic acid in one of 2 moles is used in this example

Solution and makes from this solution by electrical boric acid, 2 moles of neopentyl glycol, 2 moles of glycolic acid

Deposits coatings, which after hardening are solidly produced on 5 and 3 mol of dimethylethanolamine,

adhere to their records. which is the likely formula

, CH, -O

H ₃ CC-CH ₃ BO-CH ₂ CO-CH ₂ -CH ₂ -N

CH ₂ -O

hai and at least a small amount of the likely formula

CH ₂ -OO-CO

CH.,

CH ₃

CH ₃ -C-CH ₃

CH, -O O-CH,

CH ₃
N- <
CH ₃

N-CH ₂ CH ₂ OH

contains corresponding salt.

65 parts of the ester in the form of a 60% solids solution in isopropyl alcohol with 500 parts of the epoxy compound according to Example 12, this in the form of an 80% solids solution, is made from the reaction product with water and formic acid a clear solution with the pH 7.8, applies this at 230 volts by electrical deposition on the cathode and cures the coating for 10 minutes at 204 ^° C. The coating is hard, flexible and resistant to solvents.

Even if the preparations described in these examples have the particular advantage, that they can be deposited electrically, as described, they can also be deposited according to more conventional ones Apply procedure. Furthermore, the preparations, although they are usually acidic pH value are neutralized, in many cases not neutralized. You can continue to do certain things Reaction products that are less desirable in electrodeposition processes by other means and make coatings suitable for many purposes. These indicated here Embodiments are described in more detail in the following examples.

Example 10

A mixture of 280 parts is heated by reacting epichlorohydrin with polypropylene glycol obtained epoxy resin having an epoxy equivalent of 186 and a molecular weight of 372 and 342 parts of bisphenol A for 10 hours at 140 to 150 ° C with 11 parts of 85% formic acid and sets 547 parts of the product obtained with 1070 parts of epichlorohydrin in the presence of sodium hydroxide. After removing excess epichlorohydrin, the reaction product obtained is an epoxy compound, which contains oxalkylene groups in the polymer chain and has an epoxide equivalent of 528.

The epoxy compound is added as a mixture with 42 parts of ethylene glycol monobutyl ether acetate 30.4 parts of 2- (beta-dimethylaminoethoxy) -4-methyl-1,3,2-dioxaborinane in the manner described above and acidify the reaction product with aqueous Acetic acid to pH 5.2. The colloidal solution obtained can be used with good results deposit electrically. The coating deposited on the cathode is allowed to cure for 30 minutes Heat from 177 ° C. It then adheres firmly to his Backing and, although somewhat soft, has good solvent resistance.

If the reaction product contains only a few epoxy groups, it can happen that the Preparation does not network to the desired extent. In such cases it is often advisable to start the preparation to add another resinous substance, the one with the hydroxyl groups present in the reaction product or other groups respond. As a coreactive resin, for example, an aminoaldehyde resin, z. B. Hexakis (methoxymethyl) melamine or another melamine-formaldehyde resin or urea-formaldehyde resin or use another resin containing reactive functional groups. It can in some cases it may be expedient to add a small amount of an epoxy resin-curing catalyst. This is explained in more detail in the following example.

Example 11

1770 parts of a liquid epychlorohydrin-bis-phenol are used A epoxy resin with a viscosity of 30 to 70 poise and an epoxy equivalent of 193 to 203 and 302 parts of bisphenol A in a reaction vessel for 45 minutes at 170 to 180 ° C, cools down to 130 ° C, then adds 790 parts of 600 molecular weight polypropylene glycol and maintains the reaction mixture 130 ° C until it, at 50% solids in a mixture of 90 parts isophorone and 10 parts Toluene measured, the viscosity of L-N according to Gardner-Holdt reached. The one for the overall reaction time to this point is approximately

5 hours. The reaction mixture is then cooled to 120 ° C. and the amine present is added to neutralize

6 parts of a 90% solution of formic acid, further cooled to 70 ° C. and 318 parts of the boron compound A and 82 parts of isopropanol over 20 minutes, whereby the temperature is increased from 70 to 9O ⁰ C. The mixture is then kept at 95 ° C. for 5 minutes, then 500 parts of water are slowly added and, as soon as the mixture is homogeneous, 15.5 parts of a surface-active agent and 200 parts are slowly added.

le 2-ethylhexanol and then a further 840 parts of water.

The product contains 0.225 milliequivalents of quaternary groups, 0.213 milliequivalents per gram Lactic acid and 0.228 milliequivalents boric acid.

If the product is a 10% solids aqueous bath at a temperature of 26.7 ⁰ C and a voltage of 250 volts 90 seconds electrically deposited on phosphatized steel discs, then rinsed and cured 30 minutes at 177 ° C, to obtain a 0 .01524 mm thick film of a hardness exceeding the pencil hardness 6 H. The film is very resistant to acetone and salt spray.

Example 12 '5

336 parts of the epoxy resin from Example 11 and 113 parts of bisphenol A are charged into a reaction vessel equipped with a stirrer, a thermometer, a condenser, a device for introducing inert gas and a heating device, and the mixture is heated to 180 ^° C., after which the reaction is exothermic. The reaction mixture is kept for 45 minutes at 180 to 190 ° C, then cooled to 110 ° C gives 40 parts of isopropanol are then cooled further to 8O ⁰ C, are in the course of 20 minutes at a temperature between 80 and 90 ⁰ C a Solution of 42.7 parts of 2- (beta-dimethylaminoethoxy) -4-methyl-l, 2,3-dioxaborinane in 10.7 parts of isopropanol, keeps the mixture for 5 minutes at 94 ° C and then puts 107 parts of water in the course of 4 minutes to. A clear, brown resin solution is obtained.

The resin solution is mixed at 74 ° C. with a solution of 2.4 parts of an antifoam agent in 33 parts of 2-ethylhexanol and adjusts them to a solids content of 100%. It has the epoxy number 752 and the hydroxyl number 275.

Example 13

40

The following electrodeposable preparations are made:

A. 272 parts of the resin solution obtained according to Example 12 are added to 1630 parts of deionized water. With difficulty, a milky dispersion is formed that contains 9.36% solids and has a pH of 9.3. This preparation has a breakdown voltage of 400VoIt at 26.7 ° C. When 90 seconds to deposit this composition at a bath temperature of 26.7 ⁰ C at a voltage of 250 volts to zinc phosphate-treated steel plates, one obtains a wet, rough film , which is rough and blistered even after curing for 25 minutes at 177 ^{° C.}

According to the analysis, the deposit bath contains per milliliter

0.0374 milliequivalents of quaternary base,
0.0038 milliequivalents of amino groups and
0.0444 milliequivalents of boric acid.

B. From 272 parts of the resin solution obtained according to Example 12, 10 parts of an 85% strength lactic acid are prepared and 1630 parts of deionized water produce an electrodepositable formulation containing 10.3% Contains solids and has a pH of 6.3. The resin easily turns into an almost clear colloid disperse. The preparation has a breakdown voltage of 400 volts at 26.7 ° C. One draws up from it a zinc phosphate treated steel plate is electrodeposited and cured these 25 minutes at 177 ° C. The obtained smooth and The solvent-resistant coating has a pencil hardness of 6 H. According to the analysis, it contains Deposition bath per milliliter

0.0419 milliequivalents of quaternary base
0.0013 milliequivalents of amino groups,
0.0437 milliequivalents of lactic acid and
0.0484 milliequivalents of boric acid.
The particle size according to A and B is determined by the light scattering method. In a light source of 4358 Å, dispersion A has a particle size of 560 Å and dispersion B has a particle size of 290 Å, while in a light source of 5460 Å dispersion A has a particle size of 630 Å and dispersion B has a particle size of 300 Å .

Example 14

In a reaction vessel of the type described in Example 12 1,000 parts of epoxy resin of Example One are 11 and 335 parts of bisphenol A and the mixture heated to 170 ⁰ C, whereupon the reaction is exothermic. The reaction mixture obtained for 45 minutes at 180 ° -185 ⁰ C, then cooled to 117 ° C, is then 125 parts of isopropanol, cooled further to 8O ⁰ C, then a 80% solids solution of 230 parts of the boron compound A in isopropanol In the course of 20 minutes at a temperature of 80 to 90 ° C., the mixture is kept for 5 minutes at a temperature of 90 to 94 ° C. and then in the course of 5 minutes 375 parts of deionized water and then at a temperature of 70 ⁰ C, a solution of 7.6 parts of an antifoam in 100 parts of 2-ethylhexanol. The clear brown resin solution obtained has, adjusted to a solids content of 100%, the epoxy number 1125 and the hydroxyl number 293.

272 parts of the resin solution thus obtained are added to 1630 parts of deionized water. The resin can easily be dispersed into a blue-green colloidal solution which contains 9.74% solids and has a pH of 6.8. The preparation has a breakdown voltage of 410VoIt at 26.7 ° C. So that one coated with zinc phosphate-treated steel plates for 90 seconds by electrical deposition at a voltage of 250 volts and a bath temperature of 29.4 ⁰ C and subjecting the film obtained 25 minutes to a heat treatment at 177 ° C. A slightly textured, smooth and shiny coating is obtained. According to the analysis, the deposit bath contains per milliliter

0.0379 milliequivalents of quaternary base,
0.0011 milliequivalents of amino groups,
0.0374 milliequivalents of lactic acid and
0.0392 milliequivalents of boric acid.

Example 15

A mixture of 500 parts of the epoxy resin from Example 3 and 65 parts of isophorone is poured into it Reaction vessel of the type described in Example 12 and this mixture is added in the course of 20 minutes within a temperature range beginning at 55 ° C. and ending at 76 ° C. one of 32.2 parts Dimethylethanolamine, 22.8 parts boric acid, 15.5 parts Isopropanol and 20 parts of deionized water made solution into it. After the The reaction mixture is kept for a further 5 minutes

at 76 to 85 ° C. Then 287 parts of deionized water are added over the course of 4 minutes. Man receives the resin solution at a temperature of 62 ° C. After the analysis it has a solids content of 100% adjusted resin solution the epoxy number 573 and the hydroxyl number 93.

A deposition bath is made from 215 parts of the resin solution and 1200 parts of deionized water with a pH of 8.5 and a breakdown voltage of 200 volts. The ones from this bathroom are electric Deposited films are rough and blistered. According to the analysis, the bath contains per milliliter

0.0602 milliequivalents of quaternary bases and

0.0657 milliequivalents of boric acid.
Analysis shows that the electrodeposited film contains 0.0967 milliequivalents of quaternary borate groups per gram. The wet film contains 63% solids.

It is also made from 215 parts of the resin solution, 3 parts of an 85% lactic acid and 1200 parts Use deionized water to create a scale bath with a pH of 8.5. For this bath you can leave the above conditions by electrodeposition films of better appearance that cure to uniform coatings when treated in the heat. After the analysis contains the deposit bath per milliliter

0.0617 milliequivalents of quaternary base,

0.0337 milliequivalents of lactic acid and

0.0693 milliequivalents of boric acid.
Analysis shows that the electrodeposited wet film contains 0.1474 milliequivalents per gram of quaternary borate groups. It has a solids content of 66.9%.

Example 16

In a reaction vessel of the type described in Example 12, 400 parts of the epoxy resin is one of Example 11 and 100 parts of bisphenol A and the mixture heated to 17O ⁰ C. At this temperature, the reaction is exothermic. Maintaining the reaction mixture for 45 minutes at 175-184 ° C, cooled to 155 ° C, 90 parts of isophorone are added and cooled to 7O ⁰ C. In the following, this reaction mixture is referred to as the starting resin.

In the course of 20 minutes a solution of 55 parts of the boron compound A are added over a beginning at 70 ⁰ C and ending at 90 ⁰ C temperature interval in 14 parts of isopropanol, the mixture is kept after further 5 minutes at 90 to 96 ° C and sets continued to add 295 parts of deionized water over 10 minutes. The resin solution obtained has a clear appearance when stirred and, when at rest, a pearlescent appearance. According to the analysis, the resin solution, adjusted to a solids content of 100%, has an epoxide number of 578 and a hydroxyl number of 141.

A deposit bath with a pH of 6.7 is made from 215 parts of this starting resin and 1285 parts of deionized water. At a bath temperature of 25 ° C. and a voltage of 300 volts, this bath has a throwing power of 7.62 cm in 90 seconds. They were from this bath at a bath temperature of 25 ⁰ C, a voltage of 200 volts and a deposition time of 90 seconds films on zinc phosphate-treated steel plates electrically, and then subjected to 30 minutes of heat treatment at 177-193 ° C. The films obtained are 0.01 mm thick and have a pencil hardness of 6 H plus. They are smooth and shiny. According to the analysis, the deposit bath contains per milliliter
0.0293 milliequivalents of quaternary bases,
0.0280 milliequivalents of lactic acid and

0.0311 milliequivalents of boric acid.

55 parts of 2- (beta-dimethylaminoethoxy) -4-methyl-1,3,2-dioxaborinane are added to the starting resin described in the course of 20 minutes within a temperature interval beginning at 70 ° C. and ending at 89 ° C., and the mixture is maintained 5 minutes at 89 to 100 ⁰ C., and 285 parts of deionized water over 4 minutes. A clear resin solution is obtained which, adjusted to a solids content of 100%, has an epoxide number of 582 and a hydroxyl number of 132.5. A sediment bath with a pH of 8.9 is prepared from 215 parts of this resin solution and 1285 parts of deionized water. This bath has a throwing power of 5.4 cm. From this bath, films are deposited electrically onto zinc phosphate-treated steel plates at a bath temperature of 25 ° C., a voltage of 200 volts and a deposition time of 90 seconds, and they are subjected to a heat treatment. The films obtained have a thickness of 0.0063 to 0.0076 mm and a pencil hardness of 6 H plus. According to the analysis, the deposit bath contains per milliliter

0.0420 milliequivalents of quaternary bases and
0.0510 milliequivalents of boric acid.

Example 17

Filling in 1005 parts of the epoxy resin of Example 11 and 339 parts bisphenol A into a reaction vessel of the type described in Example 12 type, the mixture is heated to 180 ⁰ C, keeping it for 45 minutes at 180-188 ⁰ C, it is cooled to 12O ⁰ C ₁ adds 114 parts of isopropanol, cools further to 79 ° C, then adds 141 parts of a 75% solids solution of dimethylethanolamine lactate in isopropanol over 20 minutes at a temperature rising from 79 to 93 ° C Minutes at 93 to 97 ° C. and then 425 parts of deionized water are added over the course of 4 minutes. At the end of this time the reaction mixture has a temperature of 75 ⁰ C

By adding a solution of 7 parts of antifoam in 90 parts of 2-ethylhexanol a clear, yellow resin solution, hereinafter referred to as the starting resin. With a solids content of 100% the resin has an epoxy number of 1085 and a hydroxyl number of 233.

Make up 10% solids from 272 parts of the starting resin and 1630 parts of deionized water containing sedimentation bath with a pH value of 6.7. This bath is obtained by electrical deposition at a bath temperature of 27 ° C, a voltage of 250 volts and a deposition time of 90 seconds a film of uniform structure on steel plates treated with zinc phosphate. After a half-hour heat treatment at 177 ° C, the now glossy film has a thickness of 0.011 mm and the pencil hardness 6 H. One from this bath at 300 volts but otherwise under the same conditions by electrical Deposition produced and heat treated film has a thickness of 0.0127 mm and the Pencil hardness 6 H.

A mixture is made from 272 parts of the starting resin, 1630 parts of deionized water and 6.6 parts Boric acid is another bath with a pH of 6.4. Films that one from this bathroom under the

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aforementioned conditions electrically on with zinc phosphate treated steel plates have a thickness of 0.0127 mm at a tension of 250 volts and a thickness of 0.0154 mm at a voltage of 300 volts. In both cases they have Film the pencil hardness 7 H plus.

Example 18

2070 parts of the epoxy resin from Example 7, 875 parts of a polypropylene glycol are filled with a medium Molecular weight from 400 to 425, and 7 parts of dimethylethanolamine in a reaction vessel from the im Example 18, the mixture is heated to 130 to 138 ° C and held there for five and a half hours Temperature. At the end of this time, the reaction product, as measured by a 50% solids content Solution of the reaction product in a 90:10 mixture consisting of isophorone and toluene, a Gardner-Holdt viscosity of H-. One sets then to neutralize the dimethylethanolamine catalyst 4.2 parts of 90% formic acid. The product obtained has an epoxide equivalent of 800 and the hydroxyl number is 269. It is referred to below as the starting resin according to Example 27.

A mixture of 25 parts of 1-amino-2-propanol, 35.3 parts of 85% lactic acid and 14 parts is added to 500 parts of this starting resin over a period of 20 minutes within a ^{temperature interval beginning at 70 °} C. and ^{ending at 89 ° C.} Isopropanol. The reaction mixture is left to stand for 5 minutes, the temperature rising to 97 ° C., and a pearlescent dispersion is then produced by adding 315 parts of deionized water. According to the analysis, the product contains 0.159 milliequivalents of quaternary base groups, 0.133 milliequivalents of amine and 0.327 milliequivalents of lactic acid per gram. According to the analysis, the resin has adjusted to a solids content of 100% and calculates the epoxide number 1590 and the hydroxyl number 131.

Example 19

Filling in 1890 parts of the epoxy resin of Example 11 and 180 parts bisphenol A into a reaction vessel of the type described in Example 12 type, the mixture heated to 170 ° C, after which the temperature to exotherm to 182 ⁰ C increases, the mixture holds a 45 minutes between 180 and 19O ⁰ C, cools to 130 ⁰ C ₁ is a mixture of 875 parts of polypropylene glycol 425 and 8 parts of dimethylethanolamine, heated to a temperature between 130 and 137 ° C and held for about five and a half hours at this temperature to the reaction mixture A 50% solids-containing solution in a 90:10 ratio of isophorone and toluene mixture measured to give a Gardner-Holdt viscosity of J +. 9.6 parts of 90% formic acid are then added.

Are added to 500Teilen the cooled to 70 ⁰ C the reaction mixture then in the course of 18 minutes within a beginning at 7O ⁰ C and ending at 90 ⁰ C temperature interval a consisting of 18 parts of boric acid, 25.3 parts of dimethylethanolamine and 11 parts of isopropanol salt solution and thereafter 276 parts of deionized water added, the mixture keeps 5 minutes at 75 ⁰ C and then add a solution of 2, 7 parts of an antifoaming agent in 34.5 parts of 2-ethylhexanol to. The analysis of the resin gives, based on a 100% solids content, the epoxide number 920 and the hydroxyl number 71.

One sets from 220 parts of the resin solution, 47.5 parts of butylbenzyl phthalate and deionized water Electrically depositable preparation containing 5.75% solids with a pH of 7.6 and coated from this one treated with zinc phosphate at 250 volts and a bath temperature of 27 ° C for 90 seconds Steel plate by electrical deposition.

ίο The electrically storable bath contains after the Analysis per milliliter 0.0074 milliequivalents of weak acid and 0.0255 milliequivalents of Bcr. The wet electrodeposited film was analyzed to contain 75.1% solids and more per gram 0.062 milliequivalents of quaternary borate and 0.188 milliequivalents of amine.

Example 20

1135 parts of the epoxy resin from Example 11 are reacted with 108 parts of bisphenol A for 50 minutes in a reaction vessel of the type described in Example 12, 525 parts of polypropylene glycol 425 and 4.2 parts of dimethylethanolamine are added, and the mixture is kept at 130 to 137 for five and a half hours ° C, measured on a 50% solids solution in a 90:10 mixture of isophorone and toluene, to give it a Gardner-Holdt viscosity of H +, cools to 123 ° C, sets 5.1 parts 90% formic acid is added, cools further to 71 ^° C., and a mixture of 51.6 parts of dimethylethanolamine, 61.3 parts of an 85% strength lactic acid solution and 60.3 parts of neopentyl glycol is added over the course of 20 minutes at 71 ^° C. beginning and ending at 79 ⁰ C temperature interval to the reaction holds: - mixture after 5 minutes at 79-91 ⁰ C and then sets to 1000 parts of deionized water. According to the analysis, the resin solution obtained, based on a solids content of 100%, has the epoxide number 1270, the hydroxyl number 116 and the acid number 0-. It is referred to below as the starting resin.

433 parts of this starting resin, 95 parts of butylbenzyl phthalate, 19 parts of 2-ethylhexanol and 3250 parts of water are used to produce an electrically depositable preparation with a pH of 5.6 and this preparation is used to coat steel plates treated with zinc phosphate for 90 seconds at 250 volts and a bath temperature of 27 ⁰ C by electrical deposition. The deposited film is subjected to a heat treatment at 177 ^° C. for 20 minutes. A smooth, glossy film with a pencil hardness of H is obtained.

435 parts of the starting resin according to this example, 95 parts of butylbenzyl phthalate, 8.9 parts of trimethoxyboroxine, 20 parts of 2-ethylhexanol, 2 parts of an antifoam and 3250 parts of deionized water are used to produce a white pearlescent dispersion with a pH of 5.6. One carries out this dispersion by electrical deposition for 90 seconds films at 250VoIt and a bath temperature of 27 ⁰ C on zinc phosphate-treated steel plates, and then subjecting the films 20 minutes of heat treatment at 177 ⁰ C. The films have a thickness of 0.021 to 0.025 mm and the pencil hardness 4 H plus. The dispersion has a deposit capacity of 6.83 cm.

According to the analysis, this deposit bath contains 0.0238 at a solids content of 9.2% per milliliter Milliequivalents of quaternary bases; 0.0243 milliequivalents of lactic acid and 0.050 milliequivalents of boron.

Example 21

In a reaction vessel of the type described in Example 12, 1890 parts of a liquid epoxy resin, which is a polyglycidyl ether of bisphenol A with a viscosity and 100 to 160 poise and an epoxy equivalent of 185 to 192, and 180 parts of bisphenol A for 45 minutes at 175 to 180 ⁰ C to, cooled to 130 ⁰ C, are 875 parts of polypropylene glycol (MW 425) and 7 parts of dimethylethanolamine to the reaction mixture heated to 130 ° to 138 ° C and keeps it for 5 hours at this temperature to give it, at a 50% Solids-containing solution measured in a mixture consisting of isophorone and toluene in a ratio of 90:10 to give a Gardner-Holdt viscosity of H +, cools to 121 ° C., adds 4.8 g of 90% formic acid and cools further 73 ° C. At this point, the reaction mixture, the epoxy 763 and the hydroxyl number 348. It is added to the reaction mixture continues in the course of 18 minutes at a temperature of 73 to 8O ⁰ C for one from 106 parts of dimethylethanolamine, 129 parts of a 85% lactic acid solution and 53.9 parts of isopropanol existing salt solution, it keeps 7 minutes at a temperature of 80 to 100 ⁰ C, is 500 milliliters of deionized water and a solution of 15.5 parts of an antifoam agent in 208 parts of 2-ethylhexanol and then again 960 parts of water. According to the analysis, the resin solution obtained has, based on 100% solids, the epoxy number 1460 and the hydroxide number 132.5. It is referred to below as the starting resin.

220 parts of this starting resin, 47.5 parts of butylbenzyl phthalate and 1630 parts of water are prepared an electrically depositable preparation with a pH value of 8.5 is stored from this preparation 250 volts and a bath temperature of 27 ° C for 90 seconds electrically on a film with zinc phosphate treated steel plates and then heat-treats the deposited film for 20 minutes at 177 ° C. A smooth, glossy film is obtained which has a thickness of 0.0165 mm and which Has a pencil hardness of 2 H. The preparation has a deposit capacity of 5.08 cm.

From 220 parts of the starting resin according to this example, 45 parts of butylbenzyl phthalate and 2 parts are made Boric acid and 1675 parts of deionized water produce another preparation that has a pH of 5.7, and therefrom electrically deposits films on zinc phosphate treated steel plates in the above manner away. The film obtained after the heat treatment has a thickness of 0.0208 mm and a pencil hardness of 4H plus. The preparation has a scattering power of 6.99 cm.

From 220 parts of the starting resin according to this example, 45 parts of butylbenzyl phthalate and 6 parts are made Boric acid and 1675 parts of deionized water make another preparation like the previous one Preparation also has a pH value of 5.7, and stores films from it in the manner described above electrically on steel plates treated with zinc phosphate. The film obtained after the heat treatment

has a thickness of 0.020 mm and a pencil hardness of 5 H. The preparation has a scattering power of 7.30 cm.

Example 22

1890 parts of the epoxy resin from Example 11 are used and 180 parts of bisphenol A in a reaction vessel of the type described in Example 12 at 175 for 30 minutes

ίο to 180 ⁰ C in order, are 875 parts of polypropylene glycol 445 to the temperature set to 130 ⁰ C down, are then 8 parts dimethylethanolamine to, heated to 130 to 140 ^c C, holding five and a half hours at this temperature to the reaction mixture, of a 50% solids solution in a mixture consisting of isophorone and toluene in a ratio of 90:10 measured to give a Gardner-Holdt viscosity of H +, the temperature then drops to 116 ° C. and gives 9.6 parts of 90% strength Formic acid too.

Are employed 500 parts of the resin solution obtained 15 parts of dimethylethanolamine, over the course of 9 minutes at 60 to 70 ⁰ C to, allowed to stand for an additional minute at 73 ° C, then 17.8 parts of lactic acid in the course of 10 minutes at a temperature of 73 to 78 ° C, the mixture is allowed 3 minutes at 75 ° C are, gives 17.4 parts of neopentyl glycol to, stirred for 2 minutes at 71 ⁰ C are, are to 9.8 parts boric acid, allowed a short time at 75 to 77 ° C stand and then add 30 parts of deionized water. According to the analysis, based on 100% solids, the resin solution has the epoxide number 1285, the acid number 16.4 and the hydroxyl number 107.8. It is referred to below as the starting resin.

It is made from 440 parts of this starting resin, 95 parts of butylbenzyl phthalate, 19 parts of 2-ethylhexanol, 1.9 parts of an antifoam agent and 3250 parts of deionized water an electrodeposable one Preparation, stored from this at 250 volts and a bath temperature of 27 ° C for 90 seconds peeled a film on zinc phosphate treated steel panels and subject the deposited film for 20 minutes a heat treatment at 177 ° C. A smooth, hard and glossy film is obtained, which is a starch from 0.018 to 0.02 mm and has a pencil hardness of 4 H plus.

18.6 parts of 85% strength lactic acid and 19.4 parts of triethylamine are added to 500 parts of the resin adduct according to paragraph 1 of this example 35 in the course of 19 minutes within the temperature interval between 70 and 85 ° C. The reaction mixture is left to ^{stand at 85 to 90 °} C. for 5 minutes. According to the analysis, it has an epoxide number of 2790 and a hydroxyl number of 105.

Is prepared from 440 parts of this resin solution, 95 parts of butyl benzyl phthalate, 19 parts of 2-ethylhexanol, 1.9 parts of an antifoam agent and 3250 parts of deionized water, an electrically depositable preparation forth superimposed from this preparation at 250 volts and a bath temperature of 27 ⁰ C 90 Electrically deposited a film on zinc phosphate treated steel plates for seconds, and then heat-treated the deposited film at 177 ° C for 20 minutes. A smooth, glossy film is obtained which has a thickness of 0.0127 to 0.0152 mm and a pencil hardness of 3H.

Claims (8)

Patent claims: 1. Aqueous dispersion of a non-gelled water-dispersible epoxy resin, which may optionally contain solvents, characterized in that it consists of 1 to 25 percent by weight of an epoxy resin with at least one epoxy group in the molecule and a content of chemically bound nitrogen of at least 0.05% in Form of a salt of a quaternary ammonium base and an acid with a dissociation constant of greater than 1 ■ 10 " ⁵ , 0.01 to 8 percent by weight boron in the form of boric acid and optionally other common resinous materials, plasticizers, coupling solvents, pigments, antioxidants, surface treatment agents and Wetting agents. 2. Aqueous dispersion according to claim 1, characterized in that the epoxy resin has a content of chemically bound nitrogen of 0.05 to 16 percent by weight in the form of chemically bound nitrogen of a salt of a quaternary ammonium base and an acid with a dissociation constant of greater than 1 x 10 " ⁵ , owns. 3. Aqueous dispersion according to claim 1 or 2, characterized in that the epoxy resin is a Is polyglycidyl ether of a polyphenol. 4. Aqueous dispersion according to claim 1 or 2, characterized in that the epoxy resin consists of 1,1-methylene-bis- (5-substituted hydantoin) has been produced. 5. Aqueous dispersion according to claim 1 or 2, characterized in that the epoxy resin is a Ν, Ν'-diglycidyl heterocyclic compound. 6. Aqueous dispersion according to one of claims 1 to 5, characterized in that the epoxy resin additionally contains 1.0 to 90 percent by weight of oxyalkylene groups. 7. Aqueous dispersion according to one of claims 1 to 6, characterized in that it is used as the other resinous material, a melamine-formaldehyde resin or a urea-formaldehyde resin in lesser Amount than the epoxy resin contains. 8. Use of the dispersion according to any one of claims 1 to 7 for the electrical coating of electrically conductive substrates.