JPH0374709B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a process for producing a self-crosslinking cationic paint binder based on the reaction product of a modified phenol and a monoepoxy resin, which is water-dilutable upon protonation. From DE 23 20 301 A1 a paint binder is known which is obtained by the reaction of a Mannif base (obtained by the condensation of a phenol, a secondary amine alcohol and formaldehyde) with an epoxy resin. Similar resins are also available in German Patent Publication No.
It is also disclosed in No. 2419179. German Patent Publication No. 2711385 proposes the use of Mannitz condensates of phenols and/or alkylphenols, primary amines and formaldehyde, since the above paints have the disadvantage that the amines dissociate during baking. . German Patent Publication No.
No. 2711425 proposes mixing a water-insoluble urethane group-containing resin, in particular a modified polyamide amine resin, in order to improve the products of German Patent Publication No. 2320301 and others. German patent publication no.
No. 2541801 describes epoxy resins based on polyhydric alcohols in which the Mannitz base and the hydroxyl groups are reacted with semi-blocked diisocyanates and optionally with epoxy resins without urethane groups, in order to avoid dissociation of the amines. A similar method is also disclosed in German Patent Publication No. 2554080.
In all of the above, the reaction with isocyanate is useful in suppressing the dissociation of the amine during baking. However, the known products produced by the above methods do not meet the requirements of the automotive industry in terms of corrosion resistance at cross-linking temperatures of 150°C to 170°C and the adhesion of the baked coating, especially with respect to adhesion to subsequent coatings. Not satisfied. Here, we believe that the above requirements can be met if modified urea groups and urethane groups can be introduced as intended using appropriately selected starting materials and a specific manufacturing process. I found it. Patent applications that do not belong to this technology include substituted urea-
In a method for producing a self-crosslinking cationic paint binder that is based on a reaction product of a phenol-formaldehyde condensate and an epoxy resin and is water-dilutable upon protonation, (A) one or, in some cases, two binders; phenols and/or substituted phenols having a phenolic hydroxyl group, preferably monoalkylphenols,
Amino acids having on average at least one NH group per molecule obtained with monoarylphenols, monoaralkylphenols, primary amines and/or primary alkanolamines and/or alkylene diamines, and formaldehyde or formaldehyde donor substances. The alkylated product is reacted with a semi-blocked diisocyanate, or (A-1) the semi-blocked diisocyanate is reacted with a primary alkylamine and/or a primary alkanolamine and/or an alkylene diamine, and the obtained the substituted urea is reacted with formaldehyde or a formaldehyde donor and a phenol and/or a substituted phenol having one or optionally two phenolic hydroxyl groups, preferably a monoalkylphenol or a monoarylphenol or a monoaralkylphenol, and then In the reaction step (B) 50% to 100% of the phenolic hydroxyl groups,
Epoxy compound, preferably with an epoxy equivalent of 50
2,000 to 2,000 diepoxy resins. In the above reaction step (B), a monoepoxy compound is used to react the aliphatic hydroxyl groups generated in this reaction or the aliphatic hydroxyl groups already present with the diisocyanate and/or polyisocyanate. According to
It has been found that a self-crosslinking binder with excellent paint performance can be obtained. That is, the present invention provides a method for producing a self-crosslinking cationic paint binder that is water-dilutable upon protonation and is based on a reaction product of a substituted urea-phenol-formaldehyde condensate and a monoepoxy resin. A) Phenols and/or substituted phenols having one or optionally two phenolic hydroxyl groups, preferably monoalkylphenols, monoarylphenols or monoaralkylphenols, and primary alkylamines and/or primary alkanolamines and/or or (A-1) reacting an aminoalkylation product of an alkylene diamine with formaldehyde or a formaldehyde donor having at least one NH group per molecule on average, and a semi-blocked diisocyanate; A blocked diisocyanate is reacted with a primary alkylamine and/or a primary alkanolamine and/or an alkylene diamine, and the resulting substituted urea is reacted with formaldehyde or a formaldehyde donor and 1
phenols and/or substituted phenols having one or optionally two phenolic hydroxyl groups, preferably with monoalkylphenols or monoaryrifenols or monoaralkylphenols, and further in the next reaction step (B) of the phenolic hydroxyl groups. (C) 50% to 100% of the aliphatic hydroxyl groups liberated by the reaction with the monoepoxide are reacted with an equivalent amount of diisocyanate and/or polyisocyanate. This manufacturing method is characterized by: The paint binder obtained by the above production method can be used as a water-soluble paint, especially as a cathode electrodeposition paint. Aminoalkyl products of phenols suitable for the present invention are described in the known literature [HOUBEN-WEYL: Methods of Organic Chemistry, Volume XI/
Volume 1 (1957)]. The condensation of phenols and formaldehyde with urea is described, for example, in Hauben-Weyl, Volume XIV/2 (1963). In the two alternative methods of the invention, preferably polynuclear phenols, such as bis-(4-hydroxyphenyl)-methane or 2,2-bis-
Various diphenylol alkanes are used, such as (4-hydroxyphenyl)-propane or low molecular weight phenolic novolaks. Mononuclear phenols can also be used. A preferred phenol is 2,2-bis-(4-hydroxyphenyl)-propane (bisphenol A). Suitable primary amines include mono-primary amines such as butylamine or its isomers and homologs, primary alkanolamines such as monoethanolamine or its homologues, dialkylaminoalkylamines such as dimethylaminoethylamine or diethylamino Included are primary-tertiary alkyl diamines, such as propalamine, or di-primary amines, such as ethylene diamine and its congeners. In addition to alkylene diamines, diamines whose carbon chains are blocked by ether groups or amino groups can also be used. Suitable examples of this diamine include 4,7-dioxadecane-1,10-diamine, 7-methyl-4,10-dioxatrodecane-
1,13-diamine or (Here, R represents hydrogen or _CH3 , and n=1
~30. ) It is a polyoxyalkylene diamine represented by the formula. In some cases, diethylenetriamine or dipropylenetriamine, as well as polyoxypropylenetriamine or N,N′-bis-
Polyfunctional amines such as (3-aminopropyl)-ethylenediamine can also be used. It is clear that when such polyfunctional amines are used, it is necessary to appropriately select the reaction components and reaction conditions in order to prevent gelation. Especially when using polyfunctional amines, the amount of semi-blocked diisocyanate should be
It is necessary to use it according to the number of NH- functional groups. In this case, it is preferable to use mononuclear phenols. Surprisingly, even when difunctional amines are used, urea formation and aminoalkylation yield substantially homogeneous reaction products, which can be used for subsequent reactions without any restrictions. I can do it. A preferred form of formaldehyde is commercially available paraformaldehyde having a formaldehyde content of 80% or more. In a preferred embodiment of process (A), the aminoalkylation is carried out by treating the reactants in the presence of an azeotropic solvent, such as toluene or a corresponding aliphatic hydrocarbon solvent, taking into consideration the ensuing exothermic reaction. , by heating to a temperature necessary to azeotropically remove the reaction water. After removing the calculated amount of water, the solvent is removed in vacuo and the reactants are dissolved in the aprotic solvent. In some cases, the reaction can be further carried out in the presence of an azeotropic solvent. The reaction product having on average at least one secondary amine group in the molecule is then treated with an amount of semi-blocked diisocyanate corresponding to 1 mole of isocyanate compound for each NH group thereof.
React at 30℃ to 50℃. The desired urea group is formed by reaction of the NH group with the semi-blocked diisocyanate. If the reaction between the NH group and the NCO group is carried out appropriately, the hydroxyl group that may remain may react to a negligible extent. Semi-blocked diisocyanates are produced by known methods. Preferred diisocyanates are those with differently reactive NCO groups, such as tolylene diisocyanate or isophorone diisocyanate. Preferred blocking agents are aliphatic monoalcohols, which are separated off in the stoving process in the presence of (possibly by means of conventional catalysts). Examples of the various blocking agents include phenols, oximes, amines, unsaturated alcohols, and caprolactam. In an alternative method (A-1) of the first step, substituted urea is prepared from semi-blocked diisocyanate and primary amine. For this purpose, semi-blocked diisocyanate is added to a solution of the amine or a mixture of various amines in an isocyanate inert solvent such as toluene or glycol diether at 30 to 60° C. with cooling until the isocyanate value is approximately zero. Carry out the reaction until Formaldehyde, preferably as paraformaldehyde, is then added at 70°C and maintained at this temperature for 1 hour. After adding the phenol, add the reaction water to 80% or more while increasing the temperature.
Entrainment is carried out by azeotropic distillation at 140° C., preferably with the aid of an entraining agent such as toluene. Optionally, the entraining agent is then removed under vacuum and the product is dissolved in a hydrophilic solvent. In the reaction step (B), method (A) or (A-1)
The reaction product produced by is reacted with a monoepoxy compound to produce a phenol ether. Epoxy compounds include glycidyl ethers such as butyl glycidyl ether, phenyl glycidyl ether or allyl glycidyl ether, or olefin oxides,

[Formula] Oxide Oxide hmm

[Formula] Hydrocarbon oxides such as styrene oxide or cyclohexane vinyl monoxide, glycidyl esters of carboxylic acids such as glycidyl methacrylate, and ethylene oxide or propylene oxide. Particularly preferred in the production method of the present invention are KOCH acid (carboxylic acid obtained by KOCH synthesis), especially commercially available glycidyl esters of tertiary _C9 - _C11 monocarboxylic acids. Reaction at 100℃
The treatment is carried out at temperatures ranging from 130°C to 130°C until the epoxy value becomes substantially zero. Diisocyanates or polyisocyanates suitable for crosslinking the product obtained in reaction step (B) include all compounds falling within this group. Particularly suitable are tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, trimethylenehexamethylene diisocyanate, or the reaction products of diols and diisocyanates (molar ratio 1:2). Suitable polyisocyanates include the reaction products of polyols such as trimethylene propane and corresponding amounts of tolylene diisocyanate and the like.
The reaction with the diisocyanate or polyisocyanate is carried out at 50°C to 100°C with slow addition of the isocyanate compound until all NCO groups are completely reacted. Preferably, the reaction is carried out in the presence of an aprotic solvent. The intermediate products obtained at this stage as well as the final products produced therefrom show little difference, whether the intermediate products used are produced by process (A) or (A-1). It turned out that there was no. Therefore, in both cases the product will be the same basic composition in the sense of the formula below. The amount of isocyanate compound used in step (C) is 50 mol% to 50 mol% of the aliphatic hydroxyl group generated by ring opening of the glycidyl group of the monoepoxy compound.
Use an amount equivalent to 100 mol% reaction.
In preparing the reaction product, care must be taken to obtain a final reaction product with the necessary basicity to obtain a stable aqueous solution of the paint binder. In order to obtain an amine number of at least 30 mg KOH/g as a basicity, in particular by using primary-tertiary diamines in the aminoalkylation or by using suitable amines in the semi-blocking of diisocyanates. Preferably, a tertiary amino group is introduced. Water dilutability is achieved by neutralizing some or all of the basic groups of the reaction product with an acid, preferably formic acid, acetic acid or lactic acid. A degree of neutralization of 20 to 60%, corresponding to about 20 to 60 mmol of acid per 100 g of solid resin, is sufficient to obtain a practically adequate degree of water dilutability. The binder can be diluted to the desired concentration using deionized water. Optionally, it is possible to produce a toned paint before neutralization or by adding a diluent or partially diluting a crosslinking catalyst, a pigment, an extender, and other additives. The formulation of such paints and their use for electrodeposition are known to those skilled in the art and are described in the literature. When using an electrodeposition paint as an undercoat, cure it at 150°C to 170°C for 10 to 30 minutes. If the binder is not sufficiently crosslinked, additional crosslinking agents such as blocked isocyanates or amines or phenolic resins are added. In a special embodiment, polyhydroxy compounds may be added to the binder. This polyhydroxy compound may be water-soluble or substantially water-insoluble, and has a maximum hydroxyl equivalent weight.
1000, preferably 100 to 400 [Hydroxy group equivalent is the amount of resin solid content (number of grams) containing 1 mole of hydroxyl group. ]. This method improves the hydroxyl group balance, which is important for crosslinking of products, and has the potential to bring about significant improvements in electrodepositivity and coating performance. The amount of this additive added is 5% to 80% by weight, preferably 10% to 50% by weight (based on the resin solid content). Suitable water-soluble polyhydroxy compounds include:
Preferred are protonated epoxy resin amine adducts and modified substances thereof. Substances of this type are known in the literature. When selecting these substances, it is important to consider the hydroxyl equivalent. In particular, when formulating binders for electrodeposition paints, it is important to use polymeric substances that are compatible with the base resin, whether or not they are dilutable with water during protonation. is preferred. Examples of the above include polyol monomers with limited water solubility, such as trimethylolethane, trimethylolpropane, or pentaerythritol, as well as defunctionalized phenols with the necessary hydroxyl equivalents, such as ethylene oxide or Reaction products of propylene oxide and bisphenol A, deactivated phenol novolaks, epoxy resin esters, epoxy resin amine adducts that are substantially water-insoluble even after protonation, hydroxyl group-containing polyurethanes, polyamides, and copolymers thereof. Examples include commercially available copolymers of unsaturated alcohols and styrene. The components in the method of the present invention are mixed, if necessary, at a slightly elevated temperature. In particular, water-insoluble components are preferably mixed before protonation or dilution of the base resin. The products of the invention can also be applied by other application methods, such as dipping, roller or spraying, using suitable ingredients. If necessary, the byander can be processed with an organic solvent. Examples of the present invention will be shown below, but the present invention is not limited thereto. In the examples, % and % represent parts by weight and % by weight unless otherwise specified. Example 1 Into a suitable reaction vessel, 228 parts (1 mole) of bisphenol A and 260 parts of diethylaminopropapylamine
parts (2 moles) and 91% paraformaldehyde 66
(2 mol) at 90°C to 130°C in the presence of toluene as an entraining agent until the reaction water is separated.
React with. After adding 152 parts of diethylene glycol dimethyl ether, the mixture was cooled to 30°C and 608 parts (2.0 mol) of tolylene diisocyanate semi-blocked with 2-ethylhexanol were added within 45 minutes. When the entire amount of isocyanate is consumed,
Immediately 1400 parts of the resulting solution were mixed with 500 parts (2 mol) of the glycidyl ester of a saturated tertiary _C9 - _C11 monocarboxylic acid dissolved in 300 parts of diethylene glycol dimethyl ether and stirred until the epoxy number was zero. The reaction was carried out at a temperature between 100°C and 100°C. After cooling to 80° C., 210 parts (1 mol) of trimethylheximethylene diisocyanate dissolved in 53 parts of diethylene glycol dimethyl ether are added within 30 minutes. After confirming the completion of the reaction, add dibutyltin dilaurate (or other tin catalyst) to 100g of resin solids.
and 35 mmol of formic acid per 100 g of resin solids to make the resin water-soluble. Electrodeposited coatings baked at 160°C have a resistance to more than 150 back-and-forth frictions (Doppelhu¨ben) against methyl ethyl ketone.
It has resistance. Example 2 70 parts (resin solids) of the reaction product produced in Example 1 was treated with a water-insoluble polyhydroxy compound [commercially available styrene/allyl] before adding a catalyst (dibutyltin dilaurate) and a neutralizing agent. A 70% solution of alcohol copolymer (molecular weight approximately 1150) in diethylene glycol dimethyl ether has a hydroxyl equivalent of approximately 220.
Mix thoroughly with 30 parts. Then 0.6 parts of dibutyltin dilaurate (calculated as metal content) and 40 mmol of formic acid are added. Electrodeposited coatings obtained from 10% aqueous varnish by baking at 160°C have a friction resistance of more than 150 times against methyl ethyl ketone. Example 3 In the same manner as in Example 1, 440 parts (2.0 mol) of nonylphenol was added to diethylaminopropylamine.
260 parts (2.0 mol), 116 parts (1.0 mol) of 1,6-hexamethylene diamine, and 132 parts (4.0 mol) of 91% paraformaldehyde are condensed in the presence of 237 parts of toluene until 84 parts of reaction water are separated. . While cooling the reaction mixture, it was diluted with 663 parts of toluene at 40°C, and then 1248 parts of monoisocyanate (consisting of isophorone diisocyanate and ethylene glycol monoethyl ether) was added and reacted at 60°C for 1 hour. Toluene was almost completely removed in vacuo, and solids were removed with diethylene glycol dimethyl ether.
Replace so that it becomes 70%. Add 372 parts (2.0 moles) of 2-ethylhexyl glycidyl ether and continue the reaction at 95°C to 100°C until all epoxy groups have reacted. Then trimethylhexamethyl diisocyanate 105
(0.5 mol) at 75°C to 80°C with cooling.
Add within 30 to 45 minutes. The NCO value of the final product obtained is practically zero. 75 parts of the product obtained above (resin solid content),
A reaction product of 475 parts (monohydric) of bisphenol A epoxy resin and 134 parts (1 mole) of dimethylolpropionic acid (in 70% methoxypropanol solution) is mixed. Next, 0.8 parts of dibutyltin dilaurate and 45 mmol of formic acid are added to 100 g of resin solid content. Dilute with water to make the solids content 12%,
The resulting varnish is cathodically electrodeposited onto a steel plate. 160℃
(20 microns) had a reciprocating friction resistance of more than 150 times against methyl ethyl ketone. Example 4 In a similar manner, p-tert-butylphenol 150
1 part (1.0 mol) is mixed with 204 parts (2.0 mol) of dimethylaminopropylamine, 66 parts (2.0 mol) of 91% paraformaldehyde, and 100 parts of toluene at 90 to 130°C at which 42 parts of the reaction water is separated. Condense. Diethylene glycol dimethyl ether 330
After adding 496 parts of tolylene diisocyanate semi-blocked with n-butanol, slowly add at 40°C while cooling. 1315 parts of the obtained solution was reacted with 368 parts (2.0 mol) of dodecene oxide at 95°C to 100°C until the epoxy value became 0, and then reacted at 80°C with further cooling.
222 parts (1.0 mol) of isophorone diisocyanate
react with. The binder is made water soluble by adding 50 mmol of acetic acid per 100 g of resin solids. Add 0.6 parts of tin (as dibutyltin dilaurate) per 100 g of resin solids and dilute with deionized water to obtain a clear varnish with a solids content of 15%. 170℃ on steel plate,
Bake for 15 minutes to obtain an electrodeposited coating with a dry coating thickness of approximately 20 μm. This is for methyl ethyl ketone
It had a friction resistance of 200 times. Example 5 95 parts (1.0 mol) of phenol were mixed with 260 parts (2.0 mol) of diethylaminopropylamine and 66 parts (2 mol) of 91% paraformaldehyde in toluene.
80°C until 42 parts of reaction water is separated in the presence of 120 parts
React at between 130°C and 130°C. After adding 300 parts of toluene, 608 parts (2 mol) of tolylene diisocyanate was semi-blocked with 2-ethylhexanol.
React at 40℃ to 60℃ with cooling. 150 parts (1.0 mol) of phenyl glycidyl ether and
The reaction with the monoglycidyl compound is carried out at 120°C.
Then 75% of commercial triisocyanate with trimethylolpropane and tolylene diisocyanate
212 parts of solution (1 NCO equivalent) are added within 1 hour at 80°C to 100°C. At the end of the addition, a product is obtained which is free of free isocyanate groups. A clear varnish with a resin content of 15% is prepared by adding 0.8 parts of tin (as dibutyltin dilaurate), 55 mmol of formic acid, and deionized water per 100 g of resin solid content. A cathodic electrodeposition coating film baked at 170°C for 20 minutes has a friction resistance of about 150 times against methyl ethyl ketone. In Examples 6 and 7 below, method (A-
The intermediate product prepared according to 1) is used. Example 6 260 parts (2 moles) of diethylaminopropylamine
608 parts (2 mol) of diisocyanate semi-blocked with 2-ethylhexanol in 280 parts of toluene at 30 to 60°C with cooling.
and react until all NCO groups have reacted. 91%
After adding 66 parts (2 moles) of paramolardehyde,
This mixture is held at 70°C for 1 hour. Subsequently, 228 parts (1 mol) of bisphenol A are added and distilled by azeotropic distillation with the aid of toluene as an entraining agent.
40 parts of reaction water are separated at 80-140°C.
1400 parts of this solution were dissolved in saturated tertiary C ₉ -C ₁₁ - dissolved in 300 parts of diethylene glycol dimethyl ether.
500 parts of glycidyl ester of monocarboxylic acid (2
95 to 95 to zero epoxy value
React at 100℃. 210 parts of trimethylhexamethylene diisocyanate dissolved in 53 parts of diethylene glycol dimethyl ether after cooling to 80°C
(1 mol) within 30 minutes. After confirming the completion of the reaction, add 0.6 parts of dibutyltin dilaurate (or other tin catalyst) per 100 g of resin solid content (calculated as metal content), and then add dibutyltin dilaurate (or other tin catalyst) per 100 g of resin solid content.
The resin is made water soluble by adding 35 mmol of formic acid. The electrodeposition coating film baked at 160℃ has a reciprocating friction resistance of more than 150 times against methyl ethyl ketone. Example 7 260 parts (2 moles) of diethylaminopropylamine
and 116 parts (1 mole) of 1,6-hexamethylene diamine are dissolved in 875 parts of toluene, and 1248 parts of isophorone diisocyanate semi-blocked with ethylene glycol monomethyl ether are added little by little at 30 to 50°C while cooling. The temperature is maintained at 50°C until the NCO number is zero. Raise the temperature to 70℃ and at this temperature 91%
Add 132 parts (4 moles) of paraformaldehyde.
Hold at this temperature for 1 hour, then nonylphenol
Add 440 parts (2 moles). Then 80 to 140
Azeotropic distillation is carried out at a temperature of 0.degree. C. until 84 parts of reaction water have separated. After vacuum distilling the toluene, diethylene glycol dimethyl ether is used to bring the solids to 70%. 372 parts (2 moles) of 2-ethylhexyl glycidyl ether are added and the mixture is maintained at 95-100 DEG C. until all the epoxy groups have reacted. Next, at 75 to 80°C, 105 parts of trimethylhexamethylene diisocyanate (0.5
mol) within 30 to 45 minutes. At the end of this addition, the NCO value is almost zero. 70 parts of the reaction product (resin solid content) was mixed with 475 parts of bisphenol A (monohydric) and 134 parts (1 mol) of dimethylolpropionic acid (70% in methoxypropanol).
25 parts (resin solids) of the reaction product (as a solution)
and add 0.8 parts of dibutyltin and 45 mmol of formic acid per 100 g of resin solids. Dilute with water to 12% solids and cathodically electrodeposit the varnish on a steel plate.
The coating film baked at 160℃ to a thickness of about 20 microns has a resistance against methyl ethyl ketone of more than 150 times. Regarding the production method of paints using the binder obtained by the method of the present invention and their evaluation, the paints listed in Table 1 are produced and electrodeposited on a clean zinc phosphate-treated cathode steel plate by the usual method. . Electrodeposition conditions are baking (170℃ for 15 minutes)
The thickness of the post-dried coating was chosen to be 20 μm. The corrosion resistance of the coating film was determined by ASTM-B117-73 salt spray test. As other tests, a cross-cut test (DIN53151) and a mandrel test (DIN513152) were conducted. The second test result
Shown in the table. Regarding pigment paste I, a resin manufactured by the following method was used.

[Table] (3) Total solids %
Epoxidized polybutadiene oil (molecular weight approximately 1400, epoxy equivalent approximately
440) 440 parts in the presence of 0.5 part of 2,6-ditert-butyl-4-methylphenol (reaction inhibitor),
92 parts of dimethylaminopropylamine and 160℃−200
The reaction is allowed to proceed at 0.degree. C. until all the epoxy groups are consumed. After cooling to 80℃, 91% paraformaldehyde 30
part (0.9 mol) is added and 18 parts of the reaction water are azeotropically separated at 80°C using a special petroleum benzine (boiling range 80°C-120°C). After vacuum removal of the entraining agent,
Contents: ethylene glycol monobutyl ether
Dissolve in 59 parts. The produced resin has the following properties. Viscosity: 2600mPa・s/25℃ Oxazoline equivalent (calculated value): 604 Amine value: 185mgKOH/g Aliphatic content: 80% Molecular weight (calculated value): 1632 Solubility (1):
Formic acid 25 mmol (1) per 100 g of resin solids Amount of acid required to produce a stable aqueous solution This pigment dispersion vehicle (resin solids) 100
A 15% solution was prepared from 24 parts of carbon black, a 25% solution of ethylene glycol (SURFINOL 104), an acetylene alcohol-based wetting agent, 24 parts of lactic acid (5N), and deionized water. It was kneaded with 1104 parts of titanium oxide and 72 parts of basic lead silicate. (pigment/binder ratio
12:1). For the pigment paste, a resin made water-soluble by protonation and produced by the following method is used as a binder. 500 parts of a bisphenol A-based epoxy resin (epoxy equivalent: approximately 500) was dissolved in 214 parts of propylene glycol monomethyl ether, and this was mixed with 83 parts of a half ester of phthalic anhydride and -ethylhexanol with an acid value of 3 mgKOH/g. The reaction is carried out in the presence of 0.5 g of triethylamine until the following. Then, NH-functional oxazolidine 120 of aminoethylethanolamine, 2-ethylhexyacrylate and formaldehyde was prepared.
1 part and 26 parts of diethylaminopropylamine were added, and the reaction was carried out at 80°C until the epoxy value became practically zero. Dilute the reaction contents with 200 parts of propylene glycol monoethyl ether. 100 parts of this ingredient (resin solid content) is added to 1 part of carbon black.
part, 147 parts of titanium oxide and 12 parts of basic lead silicate. (Pigment/binder ratio 16:1) Even if the baking temperature is lowered to 160 DEG C. to 150 DEG C. (15 minutes, preferably 20 minutes), the results are not substantially inferior.

【table】

Claims (1)

[Claims] 1. A method for producing a self-crosslinking cationic paint binder that is water-dilutable upon protonation and is based on a reaction product of a substituted urea-phenol-formaldehyde condensate and a monoepoxy compound, A) phenol and/or substituted phenol having 1 or 2 phenolic hydroxyl groups, primary alkylamine and/or primary alkanolamine and/or alkylene diamine, and formaldehyde or formaldehyde donor, on average 1 (A-1) reacting an aminoalkylation product having at least one NH group per molecule with a semi-blocked diisocyanate; or (A-1) reacting a semi-blocked diisocyanate with a primary alkylamine and/or a primary alkanolamine and/or reacting with an alkylene diamine and reacting the substituted urea obtained with formaldehyde or a formaldehyde donor and a phenol having one or two phenolic hydroxyl groups and/or a substituted phenol, and further in the next reaction step (B ) 50% to 100% of the phenolic hydroxyl groups are reacted with a monoepoxy compound, and then (C) 50% to 100% of the aliphatic hydroxyl groups liberated by the reaction with the monoepoxide are reacted with an equivalent amount of diisocyanate and/or Or a manufacturing method characterized by reacting with polyisocyanate. 2 The substituted phenol used in the production of intermediate product (A) or (A-1) is monoalkyl, monoaryl,
or a monoaralkyl phenol. 3. The method according to claim 1 or 2, characterized in that the condensation with phenols is carried out with the aid of an entrainer at a temperature at which the water of reaction is azeotropically removed. 4. The method according to claims 1 to 3, wherein the phenol used in reaction steps (A) and (A-1) is bisphenol A. 5. The method according to any one of claims 1 to 4, characterized in that a di-primary alkylamine is used as the amine. 6 Using a primary alkylamine as the amine,
The method according to any one of claims 1 to 4, characterized in that it is used in combination with a primary to tertiary alkylamine. 7. Claims 1 to 6 characterized in that a glycidyl ester of KOCH acid is used as the monoepoxy compound in the reaction step (B).
The method described in any of the paragraphs. 8. Claims 1 to 8 are characterized in that the diisocyanate or polyisocyanate is a reaction product of a diol or polyol and a diisocyanate in a molar ratio of 1:n (where n represents the number of hydroxyl groups). The method described in any of Section 7. 9 Aminoalkylation reaction or step (A) and (A
-1) The amine value of the reaction product produced from the tertiary amine obtained from the amine used for the production of urea and/or the amine used for semi-blocking the diisocyanate is at least 30 mgKOH/g
The method according to any one of claims 1 to 8, characterized in that: