JPH05117351A - Thermosetting resin composition for coating compound - Google Patents

Abstract

PURPOSE:To obtain the title composition suitable for coating compounds of topcoating of automobiles, industrial machines, etc., because of formation of coating film having excellent long-term weather resistance, acidic rain resistance, luster, solvent resistance, etc., by blending a specific aminoformaldehyde resin with a specific copolymer. CONSTITUTION:The objective composition consisting of (A) an amino- formaldehyde resin comprising a reaction product of (i) an amino compound essentially composed of a carboguanamine of the formula (X is CH2; (n) is 0 or 1) and (ii) formaldehyde and/or a reaction product of the components (i) and (ii) and (iii) an alcohol and (B) a copolymer obtained by copolymerizing a polymerizable monomer component comprising (iv) a polymerizable monomer containing a functional group to be reacted with the component A and (V) a cycloalkyl group-containing polymerizable monomer. Methanol is preferable as the component (iii) and for example, cyclohexyl (meth)acrylate is used as the component (v).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition for coatings, which gives a coating film excellent in weather resistance and acid rain resistance. A coating film obtained by using this composition is Excellent weather resistance over a long period of time, that is, excellent gloss retention,
It has thioking resistance, yellowing resistance, crack resistance, and blister resistance, and has excellent chemical resistance and solvent resistance including durability against acid rain, as well as excellent gloss and flexibility. ..

[0002]

2. Description of the Related Art Acrylic resin and / or methacrylic resin [hereinafter, when it is desired to collectively indicate "acrylic and / or methacrylic-", "(meth)"
The expression "acrylic" will be used] as a typical application in the coating field. For example, a monomer having a hydroxyl group such as hydroxyethyl (meth) acrylate is polymerized or copolymerized with another monomer to give an acrylic polyol, and an appropriate cross-linking agent such as aminoplast resin is added to the acrylic polyol to cure at room temperature. Alternatively, it has been applied as a resin composition for curing type coating such as bake curing type. Since such a curable coating resin composition has a characteristic of high durability, it is used for applications such as automobiles, home electric appliances, steel devices, and building materials.

The aminoplast resin used here is a melamine-formaldehyde resin (hereinafter abbreviated as melamine resin) such as a reaction product of melamine, benzoguanamine and the like with formaldehyde and an alkyl etherified product of the reaction product. , Benzoguanamine-formaldehyde resin (hereinafter abbreviated as benzoguanamine resin) and the like are known.

It is also disclosed in JP-A-1-131283 that an aminoformaldehyde resin (aminoplast resin) essentially containing cyclohexanecarboguanamine or norbornanecarboguanamine is used as a coating material. That is, a coating film cured with a melamine resin may have insufficient hardness, corrosion resistance, flexibility, etc. depending on changes in baking conditions, and a coating film cured with a benzoguanamine resin has a weather resistance. There is a problem that the property is poor, but these problems can be improved to some extent by using an aminoplast resin.

Further, the use of a cycloalkyl group-containing polymerizable monomer as one component of a coating resin is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-24171, whereby the weather resistance of a coating film, It is also known that the gloss, the durability, the solvent resistance and the like can be improved.

[0006]

However, even these known modified resins for paints are used for a long time outdoors such as vehicles such as automobiles, building materials, industrial machinery, and large structures. It cannot be said that the long-term weather resistance is not always sufficient when applied to, and the acid deterioration, which has become particularly serious in recent years due to environmental pollution, is accompanied by deterioration of the coating film, which is often a problem. The present invention has been made by paying attention to the above circumstances, and its purpose is to:
In particular, the present invention is intended to provide a thermosetting resin composition for coatings, which gives a coating film excellent in weather resistance and acid rain resistance.

[0007]

The constitution of the thermosetting resin composition for coating material according to the present invention, which has been able to achieve the above object, is represented by the following general formula a

[0008]

[Chemical 3]

An amino compound (A) containing at least one carboguanamine (a) represented by
An aminoformaldehyde resin (I), which comprises a reaction compound (1a) of aldehyde with formaldehyde (B) and / or a reaction product (1b) of the amino compound (A), formaldehyde (B) and alcohol (C), and Copolymerization of a polymerizable monomer component essentially containing a polymerizable monomer (D) having a functional group capable of reacting with the aminoformaldehyde resin (I) and a cycloalkyl group-containing polymerizable monomer (E). The gist lies in the fact that it contains the copolymer (II) thus obtained.

[0010]

In the present invention, examples of the carboguanamine (a) represented by the general formula a include cyclohexane carboguanamine and norbornane carboguanamine represented by the following formulas a ₁ and a ₂ .

[0011]

[Chemical 4]

The amino compound (A) essentially contains one or two of these carboguanamines.
The amino compound (A) is the above carboguanamine (a).
However, a triazine compound such as melamine, benzoguanamine and acetoguanamine which does not correspond to the carboguanamine, urea, dicyandiamide, phenols and the like may be optionally contained.

The amount of carboguanamine (a) to be used should be appropriately determined according to the purpose of use and the required characteristics of the thermosetting resin composition for paint. The purpose of using carboguanamine (a) in the present invention is to impart excellent weather resistance and acid rain resistance to the cured film, and such a function is achieved by carboguanamine (a) in the amino compound (A).
It is recognized that the higher the content of, the higher the improvement. Therefore, the amount of carboguanamine (a) used is preferably in the range of 20 to 100% by weight, more preferably in the range of 80 to 100% by weight, in terms of the ratio in the amino compound (A).
In addition, as a compound other than the carboguanamine (a) contained in this compound (A), melamine is preferable in terms of weather resistance. In addition, melamine is preferably used as a substance that imparts hydrophilicity to the aminoformaldehyde resin (I), if desired.

The aminoformaldehyde resin (I) in the present invention is obtained from an amino compound (A) containing carboguanamine (a) as an essential component, formaldehyde (B) and optionally an alcohol (C) as raw materials. The methylol compound of the amino compound (A), the dehydrated condensate of the methylol compound and the alkyl ether compound of the methylol compound and the dehydrated condensate correspond to the aminoformaldehyde resin (I).

Such an amino formaldehyde resin
The method for producing (I) is not particularly limited, and is, for example, JP-A
It can be produced by the method disclosed in JP-A 1-131283, but preferred specific examples are as follows. (1) A method of heating the amino compound (A) and formaldehyde (B) in an aqueous solution adjusted to pH 7 to 10, preferably 7 to 9 or in a mixed solution of water and an organic solvent to carry out a methylolation reaction, ( 2) The amino compound (A) and formaldehyde (B) are heated in an aqueous solution adjusted to pH 7 to 10, preferably 7 to 9 or in a mixed solution of water and an organic solvent to perform a methylolation reaction, and then pH 3 to 7, preferably 4
To a dehydration condensation reaction at (7), (3) amino compound (A)
A method for simultaneously performing the methylolation reaction and the dehydration condensation reaction by heating the solution and formaldehyde (B) in an aqueous solution adjusted to pH 3 to 7, preferably 4 to 7 or in a mixed solution of water and an organic solvent, (4) The methylol compound of the amino compound (A) or the dehydrated condensate of the methylol compound and the alcohol (C) obtained by the above methods (1) to (3) are treated with pH.
Method of heating in an aqueous solution adjusted to 3 to 7, preferably 4 to 7, or in a mixed solution of water and an organic solvent to carry out alkyl etherification, (5) pH of amino compound (A) and formaldehyde (B) of 3 To 7 and preferably 4 to 7 in a solution of alcohol (C) and heated to simultaneously perform the methylolation reaction and the alkyl etherification reaction.

As the form of the aminoformaldehyde resin (I), the reaction products (1a) and / or (1b) obtained by the above-mentioned method may be used as they are, and the volatile matter may be distilled off if necessary. It may be diluted with water and / or a suitable solvent before use. At that time, the aminoformaldehyde resin (I) has a nonvolatile content of 30 to 10
Generally, 0% by weight, more preferably 50 to 100% by weight, of a liquid substance or a solid substance is used.

In any of the above methods, the amount of formaldehyde (B) used is preferably in the range of 1.5 to 10 mol, and particularly preferably in the range of 1.5 to 8 mol, based on 1 mol of the amino compound (A). That is, if the amount is less than 1.5 mol, the performance of the resulting aminoformaldehyde resin (I) as a cross-linking agent is poor, while if the amount is more than 10 mol, the performance corresponding to the amount used cannot be obtained. , Because it is not economical. The reaction is usually carried out at 50 to 200 ° C, preferably 50 to 150 ° C.

Alcohols used in the alkyl etherification reaction include aliphatic alcohols such as methanol, ethanol, propanol, butanol, hexanol and octanol, alicyclic alcohols such as cyclohexanol, ethylene glycol monomethyl ether and ethylene glycol. Examples thereof include ether alcohols such as monoethyl ether and ketone alcohols such as diacetone alcohol. Of course, the above alcohols may be used alone or in combination of two or more. This alcohol also functions as a solvent in the above reaction. Among these alcohols, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec
-C1-4 aliphatic alcohols such as butanol are
It is particularly preferable for enhancing the compatibility with the below-mentioned copolymer (II) and the various properties of the cured film.

The amount of the alcohol used is preferably 1.5 to 15 mol, and particularly 1. 1.
5 to 10 mol is preferred. If it is less than 1.5 mol, the alkyl etherification reaction will not proceed sufficiently, and if it is used in excess of 15 mol, the alkyl etherification reaction will not be promoted any more, which is not economically advantageous.

The polymerizable monomer (D) having a functional group capable of reacting with the aminoformaldehyde resin (I) in the present invention serves as a crosslinking point capable of reacting with the aminoformaldehyde resin (I) to form a cured crosslinked film. Amino formaldehyde resin, which is an essential ingredient for obtaining
Any compound having a functional group capable of reacting with (I) can be used without particular limitation. Examples of this functional group include a hydroxyl group, a carboxyl group, an epoxy group, an amide group, a methylolamide group, an alkoxymethylolamide group, an amino group, a silanol group, an alkoxysilyl group, and the like. A group, an epoxy group, a methylolamide group and an alkoxymethylolamide group are particularly preferable.

Examples of the polymerizable monomer (D) include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, caprolactone-modified hydroxy (meth) acrylate (for example, trade name "Placcel FM", Daicel Chemical Industries Ltd. ) Etc.), a polymerizable monomer having a hydroxyl group such as a mono (meth) acrylate of a polyester diol obtained from phthalic acid and propylene glycol, (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, maleic anhydride. Polymerizable monomer having carboxyl group such as acid, glycidyl (meth) acrylate, methylglycidyl (meth) acrylate, epoxy group-containing polymerizable monomer such as (meth) acrylate having alicyclic epoxy group, (meth ) Acrylamide, N-methylol (meth) Acrylamide, N- methoxymethyl (meth) acrylamide, N- butoxymethyl (meth)
Acrylamide, N, N-dimethylaminoethyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (Meth) acryloxypropylmethyldimethoxysilane and the like can be mentioned, and one kind or a mixture of two or more kinds selected from these groups can be used.

The cycloalkyl group-containing polymerizable monomer (E) has a coating film hardness, gloss, fleshness, solvent resistance,
It is an essential component for imparting weather resistance, and particularly when used in combination with the aminoformaldehyde resin (I), it exerts a remarkable synergistic effect in enhancing long-term weather resistance and acid rain resistance. As the polymerizable monomer (E), any of those having a cycloalkyl group and a polymerizable unsaturated group can be used, and among them, particularly preferred is the following general formula (E)
Is a compound represented by.

[0023]

[Chemical 5]

In the compound represented by the above general formula E,
Examples of the cycloalkyl group in the cycloalkyl group which may have a substituent represented by Z include monocyclic saturated hydrocarbon residues such as cyclopentyl, cyclohexyl and cyclododecyl. These cycloalkyl groups may have an alkyl group having 1 to 6 carbon atoms as a substituent, and as the alkyl in these substituents,
Examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl, heptyl, cyclohexyl and the like.

Exemplifying with specific compound names, examples of the cycloalkyl group-containing polymerizable monomer (b) include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate,
Examples thereof include tertiary butyl cyclohexyl (meth) acrylate. These 1 type (s) or 2 or more types can be used.

The proportion of each of the above-mentioned monomers (D) and (E) used in the production of the copolymer (II) from the monomer components containing the above-mentioned monomers (D) and (E) is particularly limited. Generally, 0.1-95.0% by weight of monomer (D), monomer (E)
Is preferably used in the range of 5.0 to 99.9% by weight.

Here, the amount of the monomer (E) used is 5.0% by weight.
If it is less than the above range, the resulting coating film may have poor gloss and sensation, or the synergistic effect with the aminoformaldehyde resin (I) may be weakened, and weather resistance and acid resistance may not be sufficiently exhibited. On the other hand, when the amount of the monomer (E) used exceeds 99.9% by weight, the efficiency of the cross-linking reaction with the aminoformaldehyde resin (I) becomes poor due to the insufficient amount of the monomer (D).
It causes poor weather resistance, acid rain resistance, solvent resistance, and chemical resistance of the coating film. The more preferable amount of the monomer (E) used is 5.0
-80% by weight, more preferably 10.0 to 70.0% by weight.

The copolymer (II) in the present invention basically comprises a polymerizable monomer (D) having a functional group capable of reacting with the aminoformaldehyde resin (I) and a cycloalkyl group-containing polymerizable monomer. Although it is composed of a copolymer component essentially containing the body (E), it may contain other polymerizable monomers within a range not impairing the effects of the present invention. Examples of such other polymerizable monomer include the following general formula F

[0029]

[Chemical 6]

Examples thereof include compounds represented by:
In the general formula F, the alkyl group having 1 to 2 carbon atoms represented by R ³ and R ⁴ is methyl or ethyl, and the alkyl group having 1 to 18 carbon atoms represented by Y is
Direct typified by methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, etc. A chain or branched hydrocarbon residue is exemplified.

For example, specific compound names will be illustrated. For example, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2, 2,6,6-Tetramethylpiperidine, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6- Pentamethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-
(Meth) acryloyl-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4-
(Meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,
6-Tetramethylpiperidine, 1-crotonoyl-4-
Examples thereof include crotonoyloxy-2,2,6,6-tetramethylpiperidine, which may be used alone or in combination of two or more. These are very important for improving the long-term weather resistance of the coating film. Is effective for.

Still other examples of the other polymerizable monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl ( (Meth) acrylate, tertiary butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and other (meth) acrylic acid alkyl esters; nitrogen such as vinyl pyridine and vinyl imidazole Polymerizable monomer containing; halogen-containing polymerizable monomer such as vinyl chloride and vinylidene chloride; aromatic polymerizable monomer such as styrene, α-methylstyrene, vinyltoluene; vinyl ester such as vinyl acetate; vinyl ether; (Meth) acryloni Polymerizable cyan compounds such as ril; sulfonic acid group-containing polymerizable monomers such as vinyl sulfonic acid, styrene sulfonic acid and sulfoethyl (meth) acrylate; 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) Acidic phosphoric acid ester-based polymerizable monomers such as acryloyloxypropyl acid phosphate, 2- (meth) acryloyloxy-3-chloropropyl acid phosphate, and 2-methacryloyloxyethylphenyl phosphoric acid; and further 2,4- Dihydroxybenzophenone or 2,
2-Hydroxy-4- [3-meth (meth) acryloxy-2-hydroxypropoxy] benzophenone obtained by reacting 2 ', 4-trihydroxybenzophenone and glycidyl (meth) acrylate, 2,2'-dihydroxy- 4- [3-methacryloxy-2-
Examples thereof include polymerizable ultraviolet absorbing monomers such as hydroxypropoxy] benzophenone, and one or more selected from these groups can be used.

There is no particular limitation on the method for producing the copolymer (II), and various known polymerization methods such as solution polymerization method, emulsion polymerization method, suspension polymerization method, bulk polymerization method and the like can be adopted. You can Of these, the most advantageous method is the solution polymerization method, and as the solvent used in this case, aromatic hydrocarbons such as toluene and xylene; acetic acid esters such as ethyl acetate and butyl acetate; methyl ethyl ketone;
Ketones such as methyl isobutyl ketone; Aliphatic alcohols such as isopropanol, n-butanol, isobutanol; ethylene glycol monomethyl ether,
Alkylene glycol monoalkyl ethers such as ethylene glycol monoethyl ether and diethylene glycol monoethyl ether;
These organic solvents can be used alone or as a mixed solvent.

As the polymerization initiator, azobisisobutyronitrile, benzoyl peroxide, di-tert.
An ordinary radical polymerization initiator such as -butyl peroxide can be used. These polymerization catalysts are usually used in the range of 0.1 to 10% by weight based on the total weight of the polymerizable monomers. The reaction temperature is from room temperature to 200 ° C, preferably 40 to 14 ° C.
It is in the range of 0 ° C. When carrying out the polymerization reaction, a chain transfer agent or regulator such as lauryl mercaptan, 2-mercaptoethanol, carbon tetrachloride or carbon tetrabromide may be used for the purpose of controlling the molecular weight. A copolymer (II) having a weight average molecular weight of usually 3,000 to 300,000, more preferably 8,000 to 100,000 in the present invention by such a solution polymerization method.
To get

The coating composition of the present invention comprises the solution (dispersion liquid) or powdery copolymer (II) obtained by the above procedure,
Most preferably, it is used as a liquid substance dissolved or dispersed in a solvent together with the aminoformaldehyde resin (I), and the solvent may be water and / or an organic solvent.

The thermosetting resin composition for paints of the present invention comprises the aminoformaldehyde resin (I) and the copolymer (II).
Is contained as an essential component, and the ratio of both in the composition is not particularly limited, but (I) / (II)
5 to 70/95 to 30, especially 10 to 50/90 to
It is preferably 50. In addition to the above components, the coating thermosetting resin composition of the present invention contains an appropriate amount of a melamine resin that does not correspond to the aminoformaldehyde resin (I), a benzoguanamine resin, etc. within a range that does not depart from the object of the present invention. Well known additives such as curing catalysts, pigments, dyes, fillers, surfactants, antistatic agents, antioxidants, leveling agents, dispersants, plasticizers, etc. for promoting the reaction depending on the purpose of use. Agents may be included.

In particular, when baking is carried out under a temperature condition exceeding 220 ° C., it is desirable to add an antioxidant to prevent thermal discoloration of the coating film. The antioxidant is not particularly limited as long as it is commercially available, and hindered phenols are particularly effective. Also, addition of a curing catalyst for promoting the reaction is effective in making the curing conditions mild, that is, at a low temperature for a short time. The type of curing catalyst is not particularly limited, but aromatic sulfonic acid and its amine salt are particularly preferable. In addition, the amount used is the aminoformaldehyde resin (I) and copolymer.
It is preferably 0.01 to 5% by weight, more preferably 0.1 to 3.0% by weight, based on the total amount of the non-volatile components of (II).

The thermosetting resin composition for paints of the present invention is a mixture of the aminoformaldehyde resin (I) and the copolymer (II) and, if necessary, other additives such as those mentioned above. It may be a solution or dispersion of a suitable organic solvent and / or water. The thermosetting resin composition for paints of the present invention can be suitably used as an organic solvent-based paint or a water-based paint. When used as an organic solvent-based paint, it is preferable to remove water in the aminoformaldehyde resin (I) as much as possible before use.

When used as a water-based paint, a water-soluble aminoformaldehyde resin (I) is preferable, and such aminoformaldehyde resin (I) contains melamine in an amount of 40-80.
A thermosetting resin for paints, which can be obtained by using the amino compound (A) and formaldehyde (B) and the alcohol (C), if contained by weight, as raw materials and conducting a condensation reaction according to the same procedure as described above. In order to enhance the stability of the composition, it is preferable to use alcohol (C) as an essential component. In particular, methanol is used as alcohol (C) in order not to impair the water solubility of aminoformaldehyde resin (I). More preferable. The amino compound (A) may contain an appropriate amount of an amino compound other than carboguanamine (a) and melamine, and particularly an amino compound (A) containing 20 to 60% by weight of carboguanamine (a). Can be used to further improve the coating film performance. The water-soluble aminoformaldehyde resin (I) thus obtained can be mixed with the water-soluble or water-dispersible copolymer (II) and can be suitably used as an aqueous paint.

[0040]

The thermosetting resin composition for coating material of the present invention is constituted as described above, and is obtained by copolymerizing the specific aminoformaldehyde resin (I) and the polymerizable monomer component of the specific composition. By containing the obtained copolymer (II) as an essential component, it is extremely excellent in long-term weather resistance and has excellent film forming ability such as acid rain resistance, gloss, solvent resistance, flexibility, and durability. Therefore, it can be suitably used as a paint for various vehicles such as automobiles, building materials, cans, various devices made of metal, large structures, industrial machines, home appliances, office equipment and the like.

[0041]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. In the following, "%" and "parts" mean "wt%" and "parts by weight" unless otherwise specified.

Production Example 1 19.3 g of cyclohexanecarboguanamine was placed in a 300 ml three-necked flask equipped with a stirrer, a reflux condenser and a thermometer.
(100mmol), 90% paraformaldehyde 20g (600mmo
l), water 5.7g (water in the reaction mixture is 90% paraformaldehyde in water, total 7.7g, 43% by weight of formaldehyde) and benzene 40g, and the reaction mixture is adjusted to pH 10 with an aqueous sodium hydroxide solution. Then, the mixture was heated to 60 ° C. with stirring. After further stirring at 60 ° C. for 1 hour and cooling to room temperature, the reaction solution was separated into two layers, the upper layer was the benzene layer, and the lower layer was the aqueous layer containing methylolated cyclohexanecarboguanamine. HPLC analysis of this methylolated cyclohexanecarboguanamine confirmed that no unreacted cyclohexanecarboguanamine remained. Moreover, according to ¹ H-NMR analysis, the average per 1 molecule of cyclohexanecarboguanamine
It was confirmed that 3.6 formaldehyde was added.

The obtained methylolated cyclohexanecarboguanamine aqueous solution was neutralized with concentrated nitric acid and
It was concentrated under reduced pressure at mmHg. To the obtained viscous liquid was added methyl alcohol in an amount 10 times that of methylolated cyclohexanecarboguanamine, the pH was adjusted to 3.7 with concentrated nitric acid, and the mixture was stirred at 45 ° C. for 2 hours. The reaction solution was neutralized with NaOH, concentrated under reduced pressure at 60 ° C./60 mmHg, methyl alcohol was added again, the pH was adjusted to 3.5 with concentrated nitric acid, and the mixture was further stirred at 45 ° C. for 2 hours. The obtained reaction solution was neutralized with NaOH and then concentrated under reduced pressure at 60 ° C./60 mmHg to obtain alkyl etherified cyclohexanecarboguanamine (aminoformaldehyde resin: I-1). The alkyl ether cyclohexane carboguanamine the ^(I-1) 1 H
-As a result of NMR analysis, the etherification rate was 92%.

Production Example 2 In a four-necked flask equipped with a stirrer, a thermometer, a condenser and a nitrogen gas inlet tube, 28 parts of xylene and n were added under a nitrogen gas stream.
-Butanol (12 parts) was charged and the temperature was raised to 120 ° C.
3.4 parts, 2-hydroxyethyl acrylate 6.1 parts, cyclohexyl methacrylate 26.1 parts, ethyl acrylate 16.3
Part, butyl acrylate 7.4 parts and azobisisobutyronitrile 1.2 parts were added dropwise over 2 hours, and the mixture was kept at 120 ° C. for 4 hours and the copolymer (II-
1) was obtained (nonvolatile matter 60.1%, weight average molecular weight 12000).

Production Example 3 and Comparative Production Example 1 The same as Production Example 2 except that the polymerizable monomer, solvent, polymerization initiator and temperature during the polymerization reaction used in Production Example 2 were changed as shown in Table 1. Repeat the operation of
I-2) and a comparative copolymer (IIc-1) were obtained.

[0046]

[Table 1]

Examples 1 and 2 and Comparative Examples 1 to 4 The aminoformaldehyde resin (I-1) obtained in Production Example 1,
The copolymers obtained in Production Examples 2 and 3 or Comparative Production Example 1 (II-
1), (II-2) or (IIc-1), and by mixing them in the proportions shown in Table 2, the curable coating composition (1), (2) and the comparative curable coating composition (1 ), (2), (3), and (4) were obtained. Each of the obtained coating compositions was spray-coated on a zinc phosphate-treated steel sheet, and the coating performance was tested using a test piece obtained by baking and curing under the conditions shown in Table 2. The film thickness was about 40 μm in each case. The results are shown in Table 3, and it can be seen that the coating films obtained in Examples have excellent weather resistance and acid rain resistance as compared with the coating films obtained in Comparative Examples.

[0048]

[Table 2]

[0049]

[Table 3]

In Table 3, the accelerated weather resistance test and the acid rain resistance test were carried out by the following methods. <Accelerated weathering test> Using a sunshine carbon arc weather meter (using a black panel temperature of 63 ° C,
(18 dispersed water for 2 hours), <Acid rain resistance> Spot 20% sulfuric acid aqueous solution on the test plate,
After leaving it at 40 ° C. for 1 hour and washing with water, the surface condition of the coating film is visually observed. ◎: Excellent ○: Good △: Normal ×: Poor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jiro Iro 5-8 Nishimitabicho, Suita City, Osaka Pref.

Claims (9)

[Claims] 1. The following general formula a: At least one carboguanamine (a) represented by
Of the amino compound (A) containing formaldehyde as an essential component (1a), and / or the reaction product of the amino compound (A), formaldehyde (B), and alcohol (C) (1b) A), an amino formaldehyde resin (I), a polymerizable monomer (D) having a functional group capable of reacting with the amino formaldehyde resin (I), and a cycloalkyl group-containing polymerizable monomer (E) are essential. A thermosetting resin composition for coatings, which comprises a copolymer (II) obtained by copolymerizing the polymerizable monomer component contained in 1. 2. The composition according to claim 1, wherein the carboguanamine (a) contained in the amino compound (A) is 80 to 100% by weight. 3. The composition according to claim 1, wherein the reaction product (1b) is obtained by using an aliphatic alcohol having 1 to 4 carbon atoms as the alcohol (C). 4. The polymerizable monomer (D) having a functional group capable of reacting with the aminoformaldehyde resin (I) is a hydroxyl group, a carboxyl group, an epoxy group, an amide group, a methylolamide group, an alkoxymethylolamide group, The composition according to any one of claims 1 to 3, which has at least one functional group selected from the group consisting of an amino group, a silanol group, and an alkoxysilyl group. 5. A cycloalkyl group-containing polymerizable monomer (E) has the following general formula E: The composition according to any one of claims 1 to 4, which is represented by: 6. The composition according to claim 1, wherein the weight ratio of the nonvolatile content of the aminoformaldehyde resin (I) to the copolymer (II) is 5 to 70:95 to 30. 7. The composition according to claim 1, wherein the carboguanamine (a) is cyclohexane carboguanamine. 8. The composition according to claim 1, wherein the aminoformaldehyde resin (I) is tetramethoxymethylcyclohexanecarboguanamine. 9. The copolymer (II) is obtained by using a polymerizable monomer component containing 5.0 to 99.9% by weight of a cycloalkyl group-containing polymerizable monomer (E). The composition according to any one of to 7.