DE2252536A1 - CATIONIC STORAGE PREPARATIONS - Google Patents

Description

Dr. Michael Hann October 23, 1972

Patent attorney H / W (497) 5046/5056 63 Giessen- Ludwigstrasse 67 2252536

PPG Industries, Inc., Pittsburgh, Pa., USA CATIONIC STORAGE PREPARATIONS

Priority: October 28, 1971 / USA / Ser.No. 193,591 December 1, 1971 / USA / Ser.No. 203.875

The production of coatings by electrodeposition of film-forming materials under the influence an applied electrical voltage is known and is increasingly used. With the rising Use of this process is the development of different coating compositions that are more or less result in satisfactory coatings, run parallel. Most common coating methods give no commercially satisfactory coatings and the electrodeposition of many coating materials Even if feasible, it can suffer from a number of disadvantages, such as non-uniform coatings and poor throw-around (throw power), where wraparound is understood to mean the ability to use those areas of the electrode that are affected by

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of the other electrode are removed or shielded. In addition, the received Coatings often have defects for their use in some fields, although basically electrical Coating is applicable in these areas. In particular, it causes difficulties with the Resins generally used for electrical coating have a satisfactory corrosion resistance and alkali resistance. Furthermore, many electrodeposited resins are prone to any discoloration or pollution due to chemical changes during electrolysis or on due to the nature of the resin used. This is particularly true for common carrier resins which contain polycarboxylic acids neutralized with a base. These are deposited on the anode and, because of their acidic nature, are sensitive to the usual corrosive attacks, for Example by salt, alkalis and the like. There is also an anodic deposit the non-hardened coating near the metal ions developed at the anode, causing numerous Coating mass comes to a stain.

It has now been found that these difficulties do not arise when using an electrically depositable preparation used, from an acid-solubilized, self-curing organic synthetic resin containing amino groups

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Has hydroxyl groups and blocked isocyanate groups, which are stable at room temperature in the presence of hydroxyl or amino groups and with hydroxyl groups but are reactive at elevated temperatures.

Of particular interest are aqueous, electrically depositable coating compositions which are the reaction product of a resin having an epoxy group, a primary or secondary amine, and a partially capped one or blocked organic polyisocyanate and a catalyst for urethane formation. Such coating compositions can be deposited electrically on a cathode, the obtained Coatings have very good properties, such as very good alkali resistance. age and very good corrosion resistance.

It was found ierner that prime. "E Arc lOgruppen in almost all through amino groups." Si I made, epoxygvuppenhaltige resins c. .. animal ablagerbar are to be introduced _v. One can achieve this by placing a part of epoxy groups reacts with a polyamine, the polyamine e "* secondary group and primary amino groups e- \ t ... and the primary amino groups are blocked by Ketimingx pen. On contact with water, the ketimine groups decompose and release the primary amino groups.

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BATH

The presence of primary amino groups in an acid neutralized, amine group solubilized electrodeposable resin brings a number of benefits, such as an increased system pH, greater dispersibility, especially at low theoretical neutralization levels, greater throwing power and in cases where the resin is cured by amino groups, a faster one and complete curing.

As previously stated, any can be acid neutralized and soluble by amino groups Resin made by this procedure can be modified at a time when the epoxy resin retains the F-y functionality.

The epoxy compounds used to make the electrodepositable resins can be monomeric or polymeric compounds or mixtures of compounds on the average of one or more epoxy groups per molecule. The monoepoxides can be used, but resinous epoxy compounds are preferred, in particular polyepoxides having two or more epoxy groups per molecule are used. The epoxy compound can be essentially any known epoxy compound. A particularly well-suited one The polyglycidyl ethers of polyphenols, such as, for example, bisphenol A. Man receives such connections, for example, through

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etherification of a polyphenol with epichlorohydrin in the Presence of alkali. As a phenolic compound, for example, can be used: bis ^ -hydroxyphenyl ^, 2-propane, 4,4'-dihyclroxybenzophenone, bis (4-hydroxyphenyl) 1,1-ethane, Bis (4-hydroxyphenyl) 1,1-isobutane, bis (4-hydroxy-tertiary-butylphenyl) 2,2-propane, bis (2-hydroxynaphthyl) methane, 1,5-dihydroxynaphthalene and the like. In some cases it is advantageous to use polyepoxides with a slightly higher molecular weight and to use with aromatic groups. Such compounds are obtained by using the above Diglycidyl ether reacts with a polyphenol such as bisphenol A and this product then further with epichlorohydrin to the formation of a polyglycidyl ether. The polyglycidyl ether preferably contains the polyphenol • Free hydroxyl groups in addition to the epoxy groups.

It can be the polyglycidyl ethers of the polyphenols as use such, but it is often desirable to use some of the reactive groups (hydroxyl groups or in some cases epoxy groups) with a modifying material to improve the properties of the to vary the film obtained from the resins. The esterification of epoxy resins with carboxylic acids, in particular The fatty acids that come under consideration here are so well known that it is not necessary to discuss them in detail. Are particularly suitable for this implementation saturated fatty acids, especially pelargonic acid. That

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Epoxy resin can also be modified with isocyanate group-containing organic materials or with other reactive organic materials.

Another group of suitable polyepoxides is obtained from novolak resins or similar polyphenol compounds.

Similar polyglycidyl ethers are also suitable polyhydric alcohols, which differ from polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-propylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, glycerine, bis (4-hydroxycyclohexyl) 2,2-propane and the like. Polyglycidyl ethers of polycarboxylic acids can also be used are obtained by mixing epichlorohydrin or a similar epoxy compound with an aliphatic or aromatic polycarboxylic acid, such as oxalic acid, succinic acid, glutaric acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, dimerized linolenic acid and the like. Specific examples are glycidyl adipate and glycidyl phthalate. Also suitable are polyepoxides, which can be obtained by epoxidizing an olefin unsaturated one alicyclic compound. Diepoxides also come under consideration, some of which are or contain several monoepoxides. These polyepoxides are non-phenolic compounds that can be dealt with by Epoxir dation of alicyclic olefins, for example with oxygen and using selected catalysts with perbenzoic acid, acetaldehyde monoperacetate

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or peracetic acid. To this group of polyepoxides include the epoxidized alicyclic ethers and esters that are well known in the art.

Other suitable epoxy compounds are nitrogenous ones Diepoxides as disclosed in U.S. Patent 3,365,471, 1,1-methylenebis (5-substituted epoxy resins) Hydantoil); Bis-imides containing diepoxides; U.S. Patent 3,450,711, epoxy lated ammomethyldiphenyloxide; US Pat. No. 3,312,664, N, N'-diglycidyl heterocyclic compounds; US Pat. No. 3,503,979, amino-epoxyphosphonates; UK Patent 1,172,916, 1,3,5-Triglycidylisoeyanurate and other well known compounds of this type; '· ·.

The partially or half-capped or blocked isocyanate, which is used to prepare the compounds according to of the invention can be any polyisocyanate having a portion of the isocyanato groups have been reacted with a compound, so that the blocked part obtained is exposed to hydroxyl or amino groups at room temperature. is constant, but at elevated temperatures, usually between about 93 to about 316 ° C, to react is empowered with these groups. The half-blocked polyisocyanate should on average be about a free reactive one Have isocyanate group.

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Any suitable organic polyisocyanate can be used to prepare the partially blocked organic polyisocyanate. Typical examples are: aliphatic compounds such as trimethylene, tetramethylene, pentamethylene, hexamethylene, 1,2-propylene, 1,2-butylene, 2,3-butylene, 1,3-butylene, ethylidene - and butylene diisocyanate; cycloaliphatic compounds such as 1,3-cyclopentane, 1,4-cyclohexane and 1,2-cyclohexane diisocyanate; aromatic compounds such as m-phenylene, p-phenylene, 4,4'-diphenyl, 1,5-naphthalene and 1,4-naphthalene diisocyanate; aliphatic-aromatic compounds such as 4,4'-diphenylenemethane, 2,4- or 2,6-tolylene or mixtures thereof, 4,4'-toluidine and 1,4-xylylene diisocyanate; Nuclear-substituted aromatic compounds such as dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate and chlorodiphenylene "diisocyanate, 1,3,5-triisocyanate benzene and 2,4,6-triisocyanate toluene and tetraisocyanates such as 4,4'-diphenyldimethylmethane-2 , 2 ¹ , 5,5'-tetraisocyanate; polymerized polyisocyanates such as dimers and trimers of tolylene diisocyanate and the like.

The polyisocyanate used should preferably have groups of different reactivity to to facilitate partial blocking.

The organic polyisocyanate can also be a prepolymer, which is a polyol

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2252538

finally derives from the polyether polyols, such compounds being reacted with an excess of polyisocyanate, so that prepolymers with terminal isocyanate groups are formed. Simple polyols, such as glycols, for example ethylene glycol and propylene glycol, or also other polyols, such as glycerol, trimethylolpropane, hexanetriol, pentaerythritol and the like, can be used for such prepolymers. However, monoethers such as diethylene glycol, tripropylene glycol and similar compounds are also suitable. In addition, polyethers, that is to say alkylene oxide condensates, are also suitable. The alkylene oxides can be condensed with the polyols mentioned to form polyethers, compounds such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like being considered as alkylene oxide. These compounds, which can be linear or branched, are commonly referred to as hydroxyl-terminated polyethers. Examples of such polyethers are: polyoxyethylene glycol with a molecular weight of 1540, polyoxypropylene glycol with a molecular weight of 1025, polyoxytetramethylene glycol, polyoxyhexamethylene glycol, polyoxynonomethylene glycol, polyoxydecamethylene glycol, polyoxydodecamethylene glycol and mixtures thereof. Other types of polyoxyalkylene glycol ethers can also be used. Particularly useful are polyether polyols, which are obtained from the reaction of

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Polyols obtained with alkylene oxides, the polyols being ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butylene glycol, 1,6-hexanediol and their mixtures; Glycerine, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, Dipentaerythritol, tripentaerythritol, polypentaerythritol, sorbitol, methylglucosides, sucrose and the like and as alkylene oxides such as ethylene oxide, propylene oxide, their mixtures and the like can be used.

Any suitable aliphatic blocking agent can be used as the blocking agent cycloaliphatic or alkyl aromatic monoalcohol can be used, such as low aliphatic alcohols such as methyl, ethyl, chloroethyl, propyl, butyl, amyl, hexyl, heptyl, Octyl, nonyl, 3,3,5-trimethylhexanol, decyl and Lauryl alcohol and the like; cycloaliphatic alcohols such as cyclopentanol, cyclohexanol and the like; alkyl aromatic alcohols such as phenylcarbinol, methylphenylcarbinol and monoethers of Glycols such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether and the like. It can smaller amounts of higher molecular weight, relatively non-volatile monoalcohols are also used, these compounds act as plasticizers in the coatings obtained in the invention.

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Additional blocking agents include tertiary hydroxylamines, such as diethylethanolamine and oximes, such as methyl ethyl ketone oxime, acetone oxime and cyclohexanone oxime. .

The half-masked organic polyisocyanate is obtained, . "by reacting a sufficient amount of a blocking agent with the organic polyisocyanate to achieve a product that contains a free isocyanate group. This reaction is usually exothermic. The polyisocyanate and the blocking agent are preferably mixed at low temperatures, to promote the selectivity of the conversion of the isocyanate group. There will usually be temperatures used, which are not higher than about 80 ° C. Temperatures below 30.degree. C. and particularly are preferred preferably below 10 ° C.

_s As was already mentioned, the epoxy group-containing compounds are reacted with an amine to form an adduct. The amine used can be any primary or secondary amine, but preferably a secondary amine. The amine is preferably a water-soluble amino compound. Examples of such amines are mono- and dialkylamines, such as methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, methylamine, butylamine and the like.

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As a rule, low molecular weight amines are used, however, it is also possible to use amines of higher molecular weight. This can be of particular interest be when the molecule of the resin is to be plasticized by the amine. It can also be a mixture of low molecular weight and high molecular weight amines can be used for the modification of the resin.

The amines can also contain other groups, provided that these groups do not interfere with the reaction of the amine under the given conditions, so that the reaction mixture is not gelled.

The epoxy-containing material, the half-blocked isocyanate and the amine can be reacted in an alternate order. If the epoxy group-containing material also contains hydroxyl groups, such as the higher polyglycidyl ethers of polyphenols, the epoxy group can be reacted with the half-capped polyisocyanate first. The degree of implementation is not overly critical. Sufficient amounts of the half-blocked isocyanate are preferably used in order to create a sufficient number of crosslinking points so that, in the end, a cured film is produced. As a rule, around half of the available hydroxyl groups are converted. The maximum amount converted can be the equivalent of the total hydroxyl functionality together with half of the

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Correspond to epoxy functionality.

The reaction is preferably carried out at low or moderately elevated temperatures, generally temperatures carried out below 120 ° C. Using such reaction temperatures ensures that the blocked isocyanate groups do not react with gelation and that latent crosslinking sites are retained in the molecule. Typically, the reaction is carried out in the presence of a catalyst for urethane formation carried out at a temperature between about 60 and about 120 ° C. Temperatures are frequent of about 100 ° C used.

After the completion of this reaction, the obtained Product reacted with the amine. The amine is reacted with the material containing epoxy groups by mixing of the amine and the material containing epoxy groups. The reaction is often exothermic. Given- ' if the reaction mixture can be heated to moderately elevated temperatures, for example to about 50 to about 130 ° C. Care is taken to ensure that the blocked isocyanate groups are retained. Frequently it is desirable to increase the temperature at least slightly for a sufficient period of time so that full implementation occurs.

The reacted with the epoxy-containing material

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The amount of amine should be at least sufficient to give the resin a cationic character, that is, the resin migrates to the cathode when it is made soluble by acid. In in some cases essentially all of the epoxy groups on the resin are reacted with an amine. It however, residual epoxy groups can be retained in the resin when they come into contact with water hydrolyze to form hydroxyl groups.

Alternatively, the epoxy-containing material can first react with the amine to form an amine-epoxy adduct implemented. The reaction of the amine with the epoxy-containing material occurs upon mixing of the amine with the epoxy-containing material. The reaction can be exothermic. Optionally and if necessary, the reaction mixture is heated to moderately elevated temperatures, that is, to 50 to 15Qo c, although also lower or higher temperatures can be used. It is often desired, especially with the Termination of the reaction, increasing the temperature at least slightly for a sufficient period of time, to ensure the implementation is complete.

The amount of the amine reacted with the epoxy group-containing compound is chosen so that at least

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a lot of amine is used so that the resin acquires a cationic character, i.e. it migrates to the cathode, when it is solubilized by acid. It is preferred to include all of the epoxy groups in the resin implemented the amine. The amount of amine used is evident from the above.

The 'ratio of the blocked isocyanate groups to the Hydroxyl groups in the finished aqueous dispersion are about 0/5 to about 2.0 isocyanate groups for each hydroxyl group.

The incorporation of the primary amine groups into the above Resin system as well as a two-component crosslinking system is disclosed in US application 183,590 of October 28, 19.71 disclosed. The electrodeposable system of this application contains a capped or blocked organic Polyisocyanate, an amine adduct of an epoxy group-containing resin and a catalyst for the Urethane formation.

The capped or blocked isocyanates that can be used in these formulations can be any isocyanates in which the isocyanate groups have been reacted with such a compound are that the blocked isocyanates obtained are resistant to hydroxyl or amine groups Are room temperature, but with these groups at

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higher temperatures, usually 93 to 316 ° C.

Any suitable organic can be used to prepare the blocked organic polyisocyanates Polyisocyanate can be used, such as those already mentioned.

Tertiary hydroxylamines, such as diethylethanolamine, and oximes, such as methylethylketonoxira, acetone oxime and cyclohexanone oxime, are mentioned as further blocking agents.

The adduct of the organic polyisocyanate and the blocking agent forms through Reaction of a sufficient amount of the blocking agent with the organic polyisocyanate, wherein care is taken that no free isocyanate groups remain. The reaction between the organic polyisocyanate and the blocking agent is often exothermic. The polyisocyanate and the blocking agent are preferably mixed at temperatures not higher than 80 ° C, preferably below 50 ° C to keep the exothermic effect as low as possible.

As stated earlier, this is the resin used a coating composition, which is an aqueous dispersion of a blocked organic polyisocyanate and a

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Contains resin which is an addition product of a primary and / or secondary amine to an epoxy group-containing one Resin is; this coating composition is stable at room temperature.

The epoxy-containing material used to make the adduct can be any monomeric or monomers polymeric compound or mixture of compounds having on average one or more epoxy groups per molecule be. As already stated, the epoxy groups Materials reacted with an amine to form the adduct. Any amine can be used primary or secondary amine, preferably a secondary amine, can be used. The amine is preferably a water-soluble one Amino compound. Examples of such amines include mono- and dialkylamines, such as methylamine, Ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylarain, dibutylamine, methylbutylamine and like that.

In most cases it can be done with good results Use low molecular weight amines, but it is also possible to use higher molecular weight monoamines, in particular when there is a desire to make the molecule flexible by reacting with the amine. Mixtures of low molecular weight and high molecular weight can also be used to modify the resin properties Amines are used.

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The amines can also contain other groups as long as these do not cause the reaction between the amine and the Affect epoxy-containing material and under the reaction conditions do not cause the reaction mixture to gel to lead.

The reaction of the amine with the epoxy-containing material occurs when the amine is mixed with the epoxy-containing material. This reaction can be exothermic. The reaction mixture can optionally be heated to a moderately elevated temperature be, that is to about 50 to about 150 ° C, although higher or lower temperatures in Can be used depending on the starting materials and the desired reaction. It is often desired, especially when the reaction is completed, the temperature at least slightly for increase sufficient time for full implementation to occur.

For the reaction of the amine with the material containing epoxy groups, the amount of the amine is selected so that it is at least sufficient to give the resin a cationic character, the means that it migrates to the cathode when it is solubilized by an acid. In some cases it will be essentially all of the epoxy groups on the resin reacted with the amine. However, excess epoxy

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groups remain in the resin, which hydrolyze on contact with water to form hydroxyl groups.

Polyamine amine derivatives used in forming the products of the invention are derived in turn from almost any polyamines that are capable of reacting with an epoxy group and contain a secondary amino group and primary amino groups. Preferred polyamines are the alkylene polyamines and the substituted alkylene polyamines. Particularly preferred polyamines are derived from the formal

H ₂ NRNHRNH ₂

from, where R is a bifunctional aliphatic group containing two to about 48 carbon atoms. In the polyamine compounds, R can be the same or mean different remainders. Inert or non-interfering groups can be present on the radical R.

Particularly preferred polyamines are those of the formula above in which R is aliphatic Is hydrocarbon residue. Within this group of compounds, those are particularly preferred in which R is an alkylene radical having 2 to 6 carbon atoms.

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Typical polyamines that can be used are diethylenetriamine etc. and the corresponding propylene, butylene derivatives of amines. Other amines that can be used include primary-secondary amines, such as N-aminoethylpiperazine or amines accordingly the formula

RNH-R-NH ₂

The primary amine groups are converted into ketimines by reaction converted with ketones. Such ketones can have the following structural formula:

where R 1 and R "are organic radicals which are essentially inert with regard to ketimine formation. _{R 1} and R "are preferably short alkyl radicals (1 to 4 carbon atoms). It is often advantageous to use a ketone that boils below or near the boiling point of water, or that easily distills with water. The reaction of the ketone with the primary amino groups can be illustrated by the following formula:

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-N - C

H ₂ O j

Preferred examples of ketones include the following compounds: acetone, methyl ethyl ketone, diethyl ketone, Methyl propyl ketone, methyl isopropyl ketone> Methyl n-butyl ketone, methyl isobutyl ketone, ethyl isopropyl ketone, cyclohexanone, cyclopentanone, acetophenone and the same. Particularly preferred ketones are acetone, methyl ethyl ketone and methyl isobutyl ketone.

As already stated, the secondary amine group-containing ketimine with the electrically Deposable carrier resin can be implemented at any point in time at which this is still free epoxy groups in the molecule contains.

The reaction of the amine with the epoxy-containing Material takes place when the amine and the epoxy-containing material are mixed. The reaction is often exothermic. If necessary, the reaction mixture can, if necessary, on moderately elevated temperatures are heated, for example to about 50 to about 130 ° C. This is important to make sure that the ketimine groups and the blocked ones Isocyanate groups are retained. It is common desirable to warm the temperature at least slightly for a time sufficient to full Ensure implementation.

After the reaction, the resin obtained should not

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Conditions in which the ketimine group are exposed is decomposed with the formation of free primary amino groups until the possibility of gelation or Networking with the primary amine groups does not exist, The ketimines decompose in an aqueous dispersion.

In general, the ratio of the blocked isocyanate groups is to the hydroxyl groups present in the finished aqueous dispersion between about 0.5 up to about 2.0 isocyanate groups for each hydroxyl group.

In order to ensure rapid and complete curing of the polymers according to the invention, it is in the Usually necessary to have a catalyst for urethane formation in the coating mass. As catalysts tin compounds are preferred, such as dibutyl tin dilaurate and tin acetate, but other known catalysts for urethane formation can also be used to be used. The catalyst is used in such an amount that it prevents the conversion of the deposited Film effectively promotes, for example in amounts of from about 0.5 to about 4% based on the weight of that used Polymers. Typically about 2 GewX are used.

The polymers of the invention and the catalyst mixture become electrical on a suitable substrate deposited and at elevated temperatures, for

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Example hardened from about 120 to about 316 © G. The hardening of the film takes place at least in part through the formation of urethane crosslinks. The one in networking The alcohol released by the reaction can either evaporate, depending on its boiling point or remain in the resin mixture as a plasticizer.

The aqueous systems according to the invention, which the Contain the components listed above, are very good coating compositions, especially for electrical Deposition, although they can be used in other coating processes. To a To obtain a suitable aqueous preparation, it is necessary to add a neutralizing agent. In general it is advantageous to these coating compositions from a solution with a pH between about 3 and about 9 to be electrically deposited.

The neutralization of these products is achieved by reacting all or part of the amino groups by a water-soluble acid such as formic acid, acetic acid, phosphoric acid and the like. The extent of the neutralization depends in the individual case on the properties of the particular used resin and it is generally only necessary to add enough acid that the resin is solubilized or dispersed.

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Those labeled "solubilized" and "dissolved", respectively Electrically depositable preparations or compositions are in reality complex solutions, Dispersions or suspensions or combinations of two or more of these forms of distribution in water, where the water acts as an electrolyte under the influence of the electric current. In some In some cases there is no doubt that the resin is in solution; in other cases and probably in most, the resin is in the form of a dispersion that is molecular Dispersion with a molecular size between a colloidal suspension and a real solution is.

The concentration of the product in water depends on the process parameters to be used and is generally not essential to the invention. As a rule, water is the main component of the aqueous preparation, which can contain, for example, 1 to 25% by weight of resin. If desired, various additives such as pigments, antioxidants, surface-active agents, coupling agents and the like can also be added to the preparation. The pigment formulation can contain one or more of the usual pigments, such as iron oxides, lead oxides, strontium chromate, carbon black, titanium dioxide, talc, barium sulfate, cadmium yellow, cadmium red, chrome yellow and the like.

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In the case of electrical deposition, the aqueous coating mass becomes brought into contact with an electrically conductive anode and an electrically conductive cathode, wherein the surface of the cathode is coated with the coating composition. When the electrical With the current between the anode and the cathode, the bath containing the coating compound becomes an adhesive film the coating mass deposited on the cathode. This deposition of the "coating mass" on the cathode stands in Contrasted with the process in which polycarboxylic acid resins be deposited on the anode. With the cathodic deposition of the resins according to the invention is connected a number of advantages already described. . ■

The conditions under which the electrodeposition is carried out are generally similar to those under how they are used for the electrodeposition of other coating compounds. The applied Voltage can be varied within wide limits and, for example, can be as low as like 1 volt or as high as some. thousand volts, although usually voltages between 50 and 500 volts can be used. The current density is usually between about 0.107 to 1.6 amps / 100 cm ^ (1.0-15 amps per square foot). While the electrical deposition decreases the current density.

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The method according to the invention can be used for the coating of any electrically conductive sub * Use strates, especially for plating metals such as steel, aluminum, copper and the like.

After the deposition, the coating is cured at elevated temperatures by any method, for example by baking in ovens or by heating with infrared lamps. To become a shepherd preferably temperatures from about 177 to about 218 ° C are used, although curing temperatures are also used from about 120 to about 260, even 316 ° C can be used.

The invention is explained in more detail in the following examples. All parts and percentages indicated are parts by weight, unless expressly stated otherwise.

Example A.

A cationic pigment dispersant is produced in-the 746.2 parts of stearyl glycidyl ether (Procter and Gamble's Epoxide 45) and 224 parts of ethylene glycol monobutyl ether heated to about 50 ° C and 150.2 parts of n-methylethanolamine in the course a period of 30 minutes under external conditions

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Cooling, so that the bath temperature is kept below 100 ° C., can be added. If the whole Amine is added, the bath is held for a further hour at 100 ° C before it is cooled and is then stored.

To prepare a dispersed carrier from this cationic pigment dispersant, 200 Parts of it with 38.5 parts of a. 88% lactic acid and 515 parts of deionized water.

To produce a pigment paste, 90 parts of this dispersed carrier were mixed with 4 parts of an acetylene alcohol defoamer (Surfynol 104-A), 60 parts of phthalocyanine blue, 140 parts of iron oxide brown and 306 Parts of deionized water mixed and the obtained Slurry ground in a suitable mill to a fineness of 7 Hegman.

example 1

It'wurde a partially blocked 2,4 toluene diiso. cyanate prepared by adding 260.5 parts of 2-ethylhexanol was slowly added to 348.0 parts of 2,4 toluene diisocyanate over about 1 3/4 hours. An atmosphere became dry during mixing Maintain nitrogen and through external The reaction mixture was cooled at a temperature

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temperature kept below 18 ° C. The batch was then mixed for a further four hours.

A self-crosslinking cationic polyurethane resin was prepared by first adding 100 parts of the polyglycidyl ether of bisphenol A (Epon 10 04) with an equivalent weight of 910 per epoxy group in 367.2 parts of N-methylpyrrolidone and 244.8 parts 4-Methoxy-4-methylpentanone-2 (Pent-Oxone) dissolved with stirring and heating. After dissolving and Cooling to about 60 ° C in an atmosphere of dry nitrogen was 517 parts of that described above partially blocked diisocyanate and 5 drops of dibutyltin dilaurate added as a catalyst. The batch was then heated to about 100 ° C. and held at that temperature until none free isocyanate groups were detectable, for example by infrared scanning. This took about 30 minutes at 100 ° C. The approach then became cooled to 60 ° C. and 79.2 parts of diethylamine were slowly added. After re-heating up The self-corrosive cationic urethane resin obtained was cooled to 100 ° C. for two more hours.

28 parts of this resin were at a solids content of 73.5% with 0.4 parts of dibutyltin dilaurate blended and then mixed with 1.5 parts of glacial acetic acid. In the end, about 370 parts were deionized

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tes water added. The resin dispersion obtained with a content of about 5% of non-volatile Ingredients and a pH of 4.5 was placed on a zinc-phosphated steel cathode for 90 seconds Electrically deposited at 300 volts. The film was baked at 177 ° C for 10 minutes and then had a thickness of 12.7 microns (0.5 mil) and a pencil hardness by 4H.

Example 2

It became a partially blocked 2,4-toluene diisocyanate prepared by adding 180.2 parts of ethylene glycol monoethyl ether to 348 parts of 2,4-toluene diisocyanate added over a period of about 90 minutes \ were given. The mixing was carried out under an atmosphere of dry nitrogen and under external conditions Cool so that the temperature was kept below 20 ° C.

It became a self-crosslinking cationic polyurethane resin prepared by adding 100 parts of the polyglycidyl ether of bisphenol Ä (Epon 1001) with a

• Epoxy equivalent weight of 500, in 400 parts methyl isobutyl ketone dissolved with stirring and heating

- became. The batch was then cooled to 75 ° C and there were 411.3 parts of the blocked ethylene glycol monoethyl ether adduct described above. 2,4-toluene diisocyanate slowly over the course of one

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Added hour, the bath was slowly heated to 95 to 100 ° C. The approach was then for about kept at this temperature for one hour. By infrared scanning It could be determined that all isocyanate groups had reacted. After cooling on. 80 ° C, 146.2 parts of diethylamine (essentially the stoichiometrically equivalent amount to the existing Epoxy groups) were added and the batch was heated to 100 ° C. and one hour before cooling held at this temperature.

292 parts of the above resin were blended with 23.6 parts of an 88% strength lactic acid, and it 4.4 parts of dibutyltin dilaurate were then added and the mixture slowly diluted with 3,043 parts of deionized water. The obtained bath for an electrical deposit showed a pH of 5.9 and a conductivity of 1300 tnmhos / cm. A cold-rolled steel sheet was cathodically coated at 150 volts for two minutes and then at for 45 minutes Hardened at 177 ° C. A smooth and hard film 12.7 microns thick was obtained.

Example 3

It became a partially blocked 2,4-toluene diisocyanate prepared by adding 696 parts of 2,4-toluene diisocyanate slowly to 296.5 parts of butanol in the

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ran about an hour there. Mixing took place under a dry nitrogen atmosphere and the reaction temperature was kept below 16 ° C by external cooling held. The batch was then mixed for an additional hour.

A self-crosslinking cationic polyurethane resin was prepared by first adding 100 parts of the Polyglycidyl ethers of bisphenol A (Epon 1001) with an equivalent weight of 500 g per epoxy group dissolved in 424 parts of cyclohexanone with stirring and heating. After dissolving and cooling to 55 ° C were 146.2 parts of diethylamine (essentially the stoichiometrically equivalent amount to the epoxide groups present) added and the batch was heated to 100 ° C. and at this temperature for about 1 1/2 hours held. Then there were 645.1 parts of the partially blocked diisocyanate characterized above added and the batch was heated to 125 ° C and held at this temperature for 2 1/2 hours, until no free isocyanate groups could be detected by infrared scanning. The bathroom was then heated to 100 ° C, neutralized with 270.4 g of an 88% lactic acid and with about 500 parts Water to a non-volatile content thinned by 76%.

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A black preparation of a self-crosslinking cationic polyurethane was then produced, by 40.5 parts of phthalocyanine and 94.5 parts Iron oxide brown in 9.63 parts of a cationic surfactant (American Cyanamid Aerosol C 61) and 395.37 parts of deionized water were ground and dispersed and then this paste (540 parts) with 711 parts of the neutralized resin characterized above, 67.5 parts of polycaprolactone diol plasticizer (average molecular weight 1250 - Union Carbide PCP - 2030), 9 parts Dibutyltin dilaurate and 35.47.5 parts of deionized water was blended.

The resulting electrodeposition bath contained about 12% non-volatile matter a pH of 4.6, a breakdown voltage of 240 volts, and a 14.6 cm throw at 200 volts.

A zinc-phosphated steel cathode was coated in this bath for 2 minutes at 200 volts. The coating was baked for 45 minutes at 177 ° C., producing a smooth black film with a pencil hardness of 7H and a thickness of 7 _f 6 microns.

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Example 4

A 2-ethylhexanol monourethane of 2,4-toluene isocyanate was prepared by adding 585.9 parts of 2-ethylhexanol with stirring to a mixture of 783 parts of 2,4-toluene diisocyanate and 60 parts of methyl butyl ketone were added over the course of about 5 hours, the system being cooled from the outside so that a reaction temperature below 30 ° C was maintained. After the encore was over, an additional 30 parts of methyl butyl ketone were added and the reaction was run under dry nitrogen for one stored for later use.

A self-crosslinking cationic polyurethane resin was then made by first adding 632.4 parts of the polyglycidyl ether of bisphenol A (Epon 1001) with an equivalent weight of 526 per epoxy group dissolved in 177.4 parts of methyl butyl ketone and for about 15 minutes to remove any water present heated to boiling under reflux, with a trap in the reflux device for separating Water was built in. After cooling to 70 ° C., 87.7 parts of diethylamine were added and the batch was heated to about 140 ° C with removal of about 100 parts • solvent. The approach was then on Cooled 100 ° C, the solvent was replaced and there were 522.4 parts of that described above 2-ethylhexanol monourethane of 2,4-toluene diisocyanate

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admitted. After getting the approach for a period of time Had heated to 120 ° C by one hour, all NCO groups had reacted as one could by palpation could determine with infrared light. The batch was then mixed with 196 parts of propylene glycol monomethyl ether diluted to 78% solids.

It then became a reactive plasticizer for use with this self-crosslinking cationic Urethane resin made by adding 248 parts of 2-ethylhexanol monourethane to 2,4-toluene diisocyanate to 1250 parts of polytetramethylene glycol (Quaker Oats POLYMEG 3000) of an average molecular weight of 2940 were added. The mixture was heated to 100 to 110 ° C and for held at this temperature for about 5 hours until all the NCO groups had reacted, as by scanning detected with infrared light.

487 parts of the cationic urethane resin characterized above was mixed with 43 parts of the above characterized reactive plasticizer and blended with 38 parts of ethylene glycol monohexyl ether. This mixture was neutralized with 39 parts of an 88% lactic acid, then with 8 parts Dibutyltin dilaurate and 215 parts of the pigment paste from Example 1 cut and then finally with Diluted 3465 parts of deionized water. These pigment-containing, self-crosslinking cationic elec-

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Trically depositable polyurethane preparation 'had one Solids content of about 12%, a pH of 4.5, a conductivity of 875 mrahos / cm and a two-minute period Ford throw power of 18.73 cm at 350 volts.

In the case of cathodic deposition on a non-pretreated, cold-rolled Steel sheet was at 350 volts after two minutes and after curing for 45 minutes a smooth film 7.6 microns thick and 3H pencil hardness was obtained at 177 ° C. If a scratched film was kept in a chamber with salt spray at 38 ° C, it was possible after 14 days it can be determined that there was little or no rust formation at the scoring points.

Example 5

An amine-epoxy addition product was prepared as follows:

There were 1830 parts of the polyglycidyl ether of bisphenol A (Epon 1004) with an epoxide equivalent weight of 915 dissolved in 353.2 parts of methyl butyl ketone. For this purpose, the mixture was cooled with stirring and under reflux heated to 130 ° C, with the reflux of the solvent any water present in a corresponding Trap has been separated. At 80 ° were

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then in an atmosphere of dry nitrogen 52 parts of the diketimine from one mole of diethylenetriarain and 2 moles of methyl isobutyl ketone (see US Pat 3,523,925) and 138.8 parts of diethylamine were added. The batch was heated to 120 ° C and was then held at this temperature for about 2 hours and then with 326 parts of propylene glycol monomethyl ether diluted. The polytertiary aminic cationic resin obtained, the potential primary Amine groups (which are separated from the Forming ketimine groups) was stored for later use. This product was sold as a Designated adduct C.

In order to produce a reactive cationic plasticizer, 2-ethylhexanol monourethane of 2,4-toluene diisocyanate was first prepared by adding 1953 parts of 2-ethylhexanol to 2,610 parts of 2,4-toluene diisocyanate and 200 parts of methyl butyl ketone over the course of 5 hours with stirring and external cooling were added, the reaction temperature of the batch being kept below 20 ° C. The batch was then diluted with 100 parts of methyl butyl ketone and stored under dry nitrogen.

In 'another reaction vessel 456 parts of the 2-Ethylhexanolmonourethans characterized above

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of 2,4-toluene diisocyanate (1.5 equivalents of free isocyanate) was added to 769.5 parts (1.5 equivalents) of polyoxypropylenediamine (Jefferson Jeffamine D-100O) having an amine equivalent weight of 512 over the course of 20 minutes at 40 ° C . It was then diluted with 189 parts of methyl butyl ketone so that a reactive cationic plasticizer with a nonvolatile content of 85.2% was obtained.

In another reaction vessel, the 2-EthylhexanoIdiurethan of 80 / 20-2,4 / 2,6-toluene diisocyanate was prepared by slowly adding 87.1 parts of 80 / 20-2.4 / 2,6-TolueneXdiisocyanat to 143 parts of 2- ethylhexanol, containing a drop of dibutyltin dilaurate, admitted under äusserera cooling, the temperature being maintained below 100 ° C.

To prepare an electrodepositable, heat-curable, cationic urethane resin composition, 741 parts of the above polytertiary aminic cationic resin (adduct C), 57 parts of ethylene glycol monohexyl ether, 134 parts of the above reactive cationic plasticizer, 231 parts of the above 2-ethylhexanol dilatyl diurethane, and 18 parts of the above 2-ethylhexanol dauratyl ether -Catalyst mixed and then solubilized with 46 parts of an 88% lactic acid and 1773 parts of deionized water. . .

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For pigmenting this preparation 1216 parts of the preparation were blended with 247 parts of the pigment paste of B _e ispiel A and the reaction was diluted with 2337 parts of deionized water to a content of about 12% of non-volatiles.

This deposit bath exhibited a 25.4 cm throw at 280 volts at pH 6.0 and 2 minutes. Films that on zinc-phosphated steel in the course of 2 minutes deposited at 280 volts and baked at 177 ° C for 45 minutes were smooth, hard, and flexible and 12.7 microns thick.

Example 6

It became a 2-ethylhexanol monourethane of 2,4-toluene diisocyanate prepared by adding 651 parts of 2-ethylhexanol with stirring to a mixture of 870 parts of 2,4-toluene diisocyanate and 100 parts of methyl butyl ketone were added over about 3 hours. The reaction mixture was externally cooled to a reaction temperature below 18 ° C. After the addition was complete, the batch became two more Stirred for hours and then stored under dry nitrogen for later use.

It then became a self-crosslinking cationic polyurethane with free amino groups prepared by

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first 700 parts of the polyglycidyl ether of bisphenol A. (Epon 1001) with an epoxide equivalent weight of 492, dissolved in 153.7 parts of methyl butyl ketone and refluxed warmed for about 20 minutes to remove any water. After cooling to 80 ° C 598.3 parts of the 2-ethylhexanol monourethane characterized above were obtained from 2,4-toluene diisocyanate added and the batch was heated to 90 to 95 ° C, Maintained at this temperature for about an hour, then heated to 120 to 125 ° G for about 1 1/2 hours, wherein Finally, scanning with infrared light showed that all NCO groups had been converted.

The batch was then cooled to 100 ° C and there were 73.8 parts of the diketimine from one mole of diethylenetriamine and 2 moles of methyl isobutyl ketone (Shell Chemical Co. curing agent H-I) and then 93.6 parts of diethylamine admitted. The batch was then heated to 120 ° C and kept at this temperature for one hour, then 193 parts of the monohexyl ether of ethylene glycol admitted.

In a separate container, with stirring, 1445 parts of water and 76 parts of an 88% strength aqueous Lactic acid mixed and then 1432 parts of the hot resin characterized above were slowed down

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registered. After cooling to about 110 ° C., 29 parts of dibutyltin dilaurate were added and di, e was obtained aqueous dispersion with a solids content of 44.4% was stored for later use.

It was a cationic resin for a pigmented one Dispersion prepared by first adding 500 parts of the polyglycidyl ether of bisphenol A (Epon 1001) with an epoxy equivalent weight of 500 in a blend of 96 parts of butanol and 96 parts of des Monobutyl ether of ethylene glycol by heating 55 ° C and with stirring, after which 73.1 parts of diethylamine were added. The approach was based on Heated 100 to 110 ° C and held at this temperature for 2 3/4 hours and then for later solubilization kept. For pigment grinding, 200 parts of this resin become soluble made by mixing them with 36 parts of 88% lactic acid and 273 parts of deionized water. To 73.2 parts of this solubilized pigment grind resin was added 4.8 parts of an acetyl enalkohol defoamer (Surfynol 104-A), 72 parts of phthalocyanine blue, 162 parts of iron oxide brown and 383 Parts of deionized water added. The obtained slurry was made in a ball mill with steel balls crushed.

It became a pigmented preparation of a primary Amino group-containing, self-crosslinking ca

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ionic electrodepositable resin, by 221 parts of the above pigment paste with parts of the also characterized above cationic urethane resin having a solids content of 44.4% and 2740 parts of deionized water were mixed. This preparation had a solid content of about 12%, a pH of 5.7 and a conductivity of 1165 mmhos / cm.

In the case of cathodic deposition on zinc phosphatized Steel, a Ford throw of 24.45 cm in two minutes at 320 volts is observed. Steel sheets that similarly coated and 20 minutes at 204 ° C baked showed a film thickness of 11.4 microns, a pencil hardness of 6H and none Damage to the marks. after storage for 14 days in a chamber with salt spray mists.

Example 7

It became a 2-ethylhexanol monourethane of 2,4-toluene diisocyanate prepared by adding 1953 parts of 2-ethylhexanol to a stirred mixture of 2610 Parts of 2,4-toluene diisocyanate and 200 parts of methyl butyl ketone in the course of about 3 hours and with external cooling, so that the reaction temperature stayed below 18 ° C. After the addition was complete, the product was placed under dry nitrogen for his stored for later use.

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A self-crosslinking cationic polyurethane resin with free primary amine groups was prepared by first dissolving 700 parts of the polyglycidyl ether of bisphenol A (Epon 1001) with an epoxide equivalent weight of 492 in 150 parts of methyl butyl ketone and refluxing this solution at 130 ° C for about 30 minutes to remove any water that may be present. After cooling to 100 ° C., 598.3 parts of the above-characterized 2-ethylhexanol monourethane of 2,4-toluene diisocyanate and 10 drops of dibutyltin dilaurate were added.

The batch was then heated to 120 ° C. and kept at this temperature for 35 minutes, then 143.2 parts of ethylene glycol monohexyl ether were added, followed by the addition of 96.1 parts of n-methylethanolamine and 73.8 parts of the diketimine from one mole of diethylenetriamine and 2 moles of methyl isobutyl ketone (Shell Chemical Co. curing agent HI). The batch was held at 100 ° C. for about 2 hours, then 1,400 parts thereof were placed in a stirred vessel which contained 831 parts of deionized water and 72 parts of an 88% strength lactic acid. After cooling to 43 ° C., 23 parts of dibutyltin dilaurate were added and the mixture was diluted with 582 parts of deionized water to a solids content of 40%.

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It then became a cationic pigment dispersant prepared by adding 746.2 parts of stearyl glycidyl ether (Procter and Gamble Epoxide 45) and 224 parts of ethylene glycol monobutyl ether heated to about 50 ° C and 150.2 parts of n-methylethanolamine for 30 minutes under external Cooling held so that the sowing temperature was below 100 ° C remained. After all of the amine had been added, the batch was continued for a further hour at 100.degree held before it was cooled down and stored. To make a 'grind from this cationic pigment dispersant to obtain 200 parts thereof with 38.5 parts of an 88% lactic acid and 515 parts Water mixed. To produce a pigment paste, 90 parts of this abrasive were mixed with 4 parts an acetylene alcohol defoamer (Surfynol 104-A), ': 60 Teilar Phtha Io cyan in blue, 140 Teilm iron oxide brown and 306 parts of deionized water in a ball mill mixed with steel balls and crushed.

It then became a pigment-containing preparation of a self-crosslinking cationic primary amino group containing electrodepositable resin prepared by 228 parts of the above character-

- Sized paste with 930 parts of the also above ■ characterized 40% dispersion of the cationic

- Resin diluted with 2742 parts of deionized water became. This coating bath had a pH of 6.4, a conductivity of 1510 mmhos / cm and a -2_minutes wrap around according to Ford of 21.6 cm at 250 volts.

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Films that are cathodic from this bath over the course of. 2 minutes at 250 volts on zinc-phosphated steel sheets showed a film thickness of 10.2 after baking for 20 minutes at 204 ° C Microns and were against salt spray after scribing and exposure at 38 ° C for two weeks not sensitive.

For the person skilled in the art, numerous modifications of the starting materials and the reaction conditions are straightforward Explanation possible. Other epoxy compounds, half-blocked polyisocyanates, can be used with similar results , use blocked isocyanates, ketimines, catalysts and additives.

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Claims (25)

Patent claims: 1. Process for the electrical coating of an electrically conductive surface, which acts as a cathode is used in an electrical circuit, this circuit having a cathode, an anode and contains an electrically depositable preparation, characterized in that the electrically depositable Preparation contains the following ingredients: ■. (A) an acid-solubilized, self-curing organic synthetic resin containing amino groups, hydroxyl groups and blocked isocyanate groups which are stable at room temperature in the presence of hydroxyl or amino groups and are reactive with hydroxyl groups at elevated temperatures .; · ·
and (B) a catalytic amount of a catalyst for urethane formation. 2. The method according to claim 1, characterized in that the isocyanate groups with an aliphatic Alkyl, alkoxyalkyl, cycloaliphatic alkyl, aromatic alkyl monoalcohol, a tertiary Capped hydroxylamine or a ketone, 309831/1091 2252538 3. The method according to claim 2, characterized in that the isocyanate groups with an aliphatic Alkyl or alkoxyalkyl monoalcohol are capped. 4. "The method according to claim 1, characterized in that that the isocyanate groups and the hydroxyl groups are latent in a ratio of about 0.5 to about 0.2 Urethane groups are present per hydroxyl group. 5. The method according to any one of claims 1 to 4, characterized characterized in that (A) is derived from a reaction product of a polyglycidyl ether of a polyphenol, a primary or secondary amine and a half-capped organic polyisocyanate with an average of one free isocyanate group. 6. The method according to claim 5, characterized in that the isocyanate groups with an aliphatic alkyl or alkoxyalkyl monoalcohol are capped. 7. The method according to claim 6, characterized in that that the isocyanate groups with an aliphatic Alkyl or alkoxyalkyl monoalcohol are capped. 8. The method according to claim 5, characterized in that the isocyanate groups and the hydroxyl groups present in a ratio of about 0.5 to about 0.2 latent urethane groups per hydroxyl group are. 309831/1091 9. Electrically depositable organic synthetic resin _9, characterized in that it contains amino groups, hydroxyl groups and blocked isocyanate groups which are stable at room temperature in the presence of ■ hydroxyl groups and amino groups., at elevated temperatures but with hydroxyl. groups are reactive * 10. Bath for the electrical deposition of a synthetic resin on an electrically conductive substrate, characterized in that it contains the following components: (A) an acid-solubilized, self-curing organic synthetic resin containing amino groups, Hydroxyl groups and blocked isocyanate groups that are present at room temperature of hydroxyl or amino groups are stable and with hydroxyl groups at elevated levels * · Temperatures are reactive, contains; and (B) a catalytic amount of a catalyst for urethane formation. 11. Process for the production of an electrical deposition, resin, characterized in that one (A) an organic synthetic resin having epoxy groups with (B) a primary secondary amine reacts, and the product obtained with 309831/1091 (C) a half-blocked organic polyisocyanate reacts, this polyisocyanate im Average has one free isocyanate group and the blocked isocyanate groups are resistant to this product at room temperature, but with hydroxyl groups react to elevated temperatures. 12. A method for producing an electrically depositable resin, characterized in that one (A) an epoxy resin containing hydroxyl groups (B) a half-blocked organic polyisocyanate reacts, this polyisocyanate on average contains a free isocyanate group and the blocked isocyanate groups at room temperature are stable in the presence of this product, but at elevated temperatures with Hydroxyl groups react, and the product containing epoxy groups with (C) a primary or secondary amine. 13. Preparation, characterized by a self-curing organic synthetic resin, the amino groups, hydroxyl groups and contains blocked isocyanate groups, the latter groups in the presence of hydroxyl or amino groups are stable at room temperature, but with hydroxyl groups react at elevated temperatures. 309831/1091 2252538 14. Aqueous electrically depositable preparation, characterized by a dispersion of: (A) an acid-solubilized, self-curing synthetic resin that Contains amino groups, hydroxyl groups and blocked isocyanate groups, the latter being mentioned Groups stable in the presence of hydroxyl or amino groups at room temperature but react with hydroxyl groups at elevated temperatures, and (B) a catalytic amount of a catalyst for urethane formation. 15. Process for the electrical coating of an electrically conductive surface, which is used as a cathode in an electrical circuit is used, this circuit having a cathode, an anode and contains an electrically depositable preparation, characterized in that it contains electrically depositable preparation made soluble by neutralization of amino groups. , tes contains organic synthetic resin, this synthetic resin having hydroxyl groups which are curable by crosslinking via urethane groups and at least some of the amino groups mentioned are primary amino groups. · «· 309831/1091 16. The method according to claim 15, characterized in that that the electrically depositable preparation is made by neutralization with acid contains organic synthetic resin solubilized by amino groups, which has hydroxyl groups, which can be hardened by crosslinking urethane groups are, whereby this resin is made of a resin with epoxy groups and at least some of these epoxy groups are reacted with a polyamine with latent primary amino groups, which are blocked by ketimine groups, and with a secondary amino group. 17. The method according to claim 15, characterized in that the synthetic resin contains: (A) an acid-solubilized addition product which is the reaction product of a primary or secondary amine, a polyamine derivative with at least one latent primary amino group that is capped by a ketimine group and with a free secondary amino group and an epoxy group-containing resin; (B) a capped polyisocyanate, which at Räuötn temperature in the presence of the polyamine resin is stable, but with this polyamine resin at increased Temperatures reacts and (C) a catalytic amount of a catalyst for urethane formation. 309831/1091 18. The method according to claim 17, characterized in that that the polyamine derivative is a diketimine, which is derived from one mole of diethylenetriamine and 2 moles of methyl isobutyl ketone. 19. The method according to claim 17, characterized in that (A) and (B) in a ratio of There are about 0.5 to 2.0 latent isocyanate groups per hydroxyl group. 20. The method according to claim 15, characterized in that the electrically depositable preparation is as follows Components contains: (A) an acid-solubilized self-hardening organic synthetic resin having amino groups which are at least in part primary amino groups, hydroxyl groups and blocked isocyanate groups, which are stable at room temperature in the presence of hydroxyl or amino groups, but with hydroxyl groups react at elevated temperatures; and (B) a catalytic amount of a catalyst for urethane formation. 21. Electrically depositable resin characterized by an organic synthetic resin with amino groups that can be neutralized by acid and with polyurethane crosslinking curable hydroxyl groups, at least some of the amino groups being primary amino groups. 309831/1091. 22. Electrically depositable resin according to claim 21, characterized by a soluble-feasible organic Synthetic resin, the amino groups which can be neutralized by acid and hydroxyl groups which can be hardened by urethane crosslinking possesses, this synthetic resin was made of a resin with epoxy groups, which at least have been partially reacted with a polyamine with latent primary amino groups, which by Ketimine groups are capped, and with a secondary Amino group. 23. Aqueous bath for electrical deposition of Synthetic resins characterized by one made soluble by neutralizing amino groups with acid organic synthetic resin containing hydroxyl groups that are curable by urethane group crosslinking, wherein at least some of the amino groups are primary amino groups. 24. Aqueous bath for the electrical deposition of synthetic resins, characterized by a neutralization organic synthetic resin solubilized by amino groups with acid and containing hydroxyl groups, which are curable by urethane group crosslinking, this synthetic resin made of a resin with epoxy groups and at least some of the epoxy groups have been reacted with a polyamine and this polyamine capped by ketimine groups primary amino groups and secondary amino groups. 309831/109 ¹ 25. A process for the preparation of an acid-soluble, amino group-containing one Resin with hydroxyl groups curable by urethane formation, this resin being different from a resin with epoxy groups, characterized in that at least some of the epoxy groups have been reacted with a polyamine derivative that has latent primary amino groups replaced by ketimine groups are capped, and contains a secondary amino group. 309831