JP2664211B2 - Curable paint - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a curable paint containing a modified epoxy resin of a nitrogen-containing alkyd resin having a nitrogen atom in a main skeleton as a vehicle component.

(Prior Art) An alkyd resin-based coating composition containing a alkyd resin obtained by reacting a polybasic acid and a polyhydric alcohol (and sometimes using a fatty acid in combination) as a vehicle component is low-cost. It has excellent coating workability, adhesion, and solid feeling (especially in solid color finish), and is used in a wide range of fields.

However, in the modern age of technological innovation, the level of performance required for paints has inevitably increased. Among them, regarding alkyd resin paints, pigment dispersibility of paints, pigment dispersion stability (gloss of paint film, Poor finish appearance such as sharpness), and poor performance such as adhesion of coating film, corrosion resistance, chemical resistance and mechanical properties.

On the other hand, the present applicant has proposed a nitrogen-containing alkyd resin in which a nitrogen atom has been introduced into the main skeleton of the alkyd resin (Japanese Unexamined Patent Publication No.
No. 61-28562). However, the nitrogen-containing alkyd resin paint has not been satisfactory in the field where high coating performance such as high corrosion resistance and mechanical properties is required.

(Problems to be Solved by the Invention) An object of the present invention is to provide a composition having improved corrosion resistance and mechanical properties of a nitrogen-containing alkyd resin coating film without deteriorating the pigment dispersibility of the coating material. It was done.

(Means for Solving the Problems) The present invention relates to an alkanolamine compound having one hydroxyl group and a primary amino group or a secondary amino group in one molecule and / or an alkanolamine compound having two or more hydroxyl groups in one molecule. An epoxy resin modified nitrogen-containing alkyd resin obtained by modifying a nitrogen-containing alkyd resin obtained by condensation reaction of a polyhydric alkanolamine compound and a polybasic acid further having a polyhydric alcohol and a fatty acid with an epoxy resin, if necessary, as a vehicle component And a curable paint characterized in that:

The epoxy resin-modified nitrogen-containing alkyd resin, which is a vehicle component of the paint of the present invention, is obtained by subjecting a component comprising a polybasic acid and an amine compound as essential components, and further, a polyhydric alcohol and a fatty acid as necessary to a condensation reaction. The nitrogen-containing alkyd resin is modified with an epoxy resin.

The polybasic acid is composed of a polycarboxylic acid compound having two or more carboxyl groups in one molecule, such as succinic acid, adipic acid, azelaic acid,
Aliphatic saturated dibasic acids such as sebacic acid, dodecynyl succinic acid and their anhydrides, aliphatic unsaturated dibasic acids such as maleic acid, fumaric acid, itaconic acid and their anhydrides, phthalic acid, isophthalic acid, terephthalic acid , Aromatic polybasic acids such as trimellitic acid, pyromellitic acid and their anhydrides, tetrahydrophthalic acid, methylcyclohexentricarboxylic acid, hexahydrophthalic acid, hymic acid, heptic acid, tetrachlorophthalic acid, cyclohexanedicarboxylic acid, Alicyclic polybasic acids such as methylhexahydrophthalic acid, hexahydrotrimellitic acid and anhydrides thereof;
Species or two or more species can be used.

The amine compound to be reacted with the polybasic acid is one in one molecule.
Alkanolamine compound having _two hydroxyl groups and NH ₂ (a primary amino group bonded with C—NH ₂ ) or NH (secondary amino group bonded with C—NH—C), and two or more hydroxyl groups in one molecule And a polyvalent alkanolamine compound having the formula:

Examples of the amine compound include those represented by the general formula (I) In the formula, R ¹ and R ² are the same or different and each represent a hydrogen atom, an alkyl group, an aryl group, or a cycloalkyl group, n represents an integer of 1 to 4, and m represents an integer of 0 to 4. However, when m is 0, ^one of R ¹ and R ² is a hydrogen atom.

An alkanolamine compound having one hydroxyl group and a primary amino group or a secondary amino group in one molecule represented by the formula (II): In the formula, R ³ represents a hydrogen atom, an alkyl group, an aryl group, a cycloalkyl group, a —C _n H _2n —OH group, and n has the same meaning as described above.

And polyhydric alkanolamine compounds having two or more hydroxyl groups in one molecule.

In the general formulas (I) and (II), examples of the “alkyl group” include methyl, ethyl, n-propyl,
iso- propyl, n- butyl, iso- butyl, sec- butyl, tert- butyl, n- hexyl, 2-ethylhexyl and lauryl and the like, with preference given to a lower alkyl group of C ₁ ~ _4. The "cycloalkyl group" is preferably a cyclohexyl group. Further, the "aryl group" includes a phenyl group, a toluyl group, a xylyl group and the like.

Specific examples of the general formula (I), for example _{OH-CH 2 -NH 2, OH} -C 2 H 4 -NH 2, OH-CH 2 -NH-CH 3, OH-C 2 H 4 -NH-CH _{3, OH-C 2 H 4} -NH-C 2 H 5, OH-C 2 H 4 -NH-C 3 H 7, OH-C 2 H 4 -NH-C 2 H 4 CH 3, OH-C 2 _{H 4 -NH-C 4 H 9} , _{OH-C 3 H 6 -NH 2} , OH-C 3 H 6 -NH-CH 3, OH-C 3 H 6 -NH-C 2 H 7, OH-C 3 H 6 -NH-C 3 H 7, _{OH-C 3 H 6 -NH-} C 2 H 4 CH 3, OH-C 3 H 6 -NH-C 4 H 9, _{OHC 2 H 4 -N-C 2} H 4 -NH 2, OHC 2 H 4 -NH 2 -C 2 H 4 -NH 2, And the like.

Further, specific examples of the general formula (II) include, for example, (OH—C ₂ H _{4 2} NH, _{(OH-C 2 H 4)} 3 -N, And the like.

The ratio of the two components in the condensation reaction between the above polybasic acid and the amine compound is suitably in the range of 0.5 to 1.2, particularly 0.7 to 0.7, based on the polybasic acid / amine compound (molar ratio). 1.0 is particularly preferred. The proportion of the amine compound used is based on the total amount of the polybasic acid component and the amine compound (the total amount including the polyhydric alcohol and the fatty acid in the case of the following system). 0.5 to 55% by weight, preferably 0.5 to 40% by weight from the viewpoint of exhibiting excellent properties such as heat resistance, weather resistance and adhesion to a material.
%, Particularly preferably 1 to 20% by weight.

Examples of the polyhydric alcohol that can be used as necessary include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol, neopentyl glycol, 1,2-, 1,3-, and 2,3-. , 1,4-butylene glycol, pentadiol, 2,3-dimethylpropanediol, 1,6-, 2,5-hexanediol, hydrogenated bisphenol A, cyclohexanedimethanol, trimethylene glycol, tetramethylene glycol, hexamethylene There are glycol, trimethylolethane, trimethylolpropane, glycerin, diglycerin, dipentaerythritol, sorbitol and the like, and one or more selected from these can be used.

In addition, the fatty acids include drying oils (including semi-drying oils).
Fatty acids (iodine value of about 100 or more), non-drying oil fatty acids (iodine value of less than about 100), and oils and fats thereof can be used.
As the drying oil fatty acid, for example, safflower oil fatty acid,
Linseed oil fatty acid, soybean oil fatty acid, sesame oil fatty acid, poppy oil fatty acid, eno oil oil fatty acid, hemp oil fatty acid, grape kernel fatty acid, corn oil fatty acid, tall oil fatty acid, sunflower oil fatty acid, cottonseed oil fatty acid, walnut oil fatty acid, tung oil fatty acid, dehydrated Castor oil fatty acids, rice bran oil fatty acids, and dimer acids thereof, and the like, and examples of the non-drying oil fatty acids include coconut oil fatty acids. The amount of these fatty acids used is 0 to 60% by weight, preferably 5 to 60% by weight, more preferably 10 to 60% by weight, based on the total amount of the polybasic acid component, the polyhydric alcohol component and the fatty acid. A range of 45% by weight is suitable.

The nitrogen-containing alkyd resin is a polybasic acid and an amine compound, if necessary, including a polyhydric alcohol and a fatty acid, under the same conditions as ordinary alkyd resins, for example, 150
It can be produced by reacting at ~ 250 ° C for 1 to 15 hours.

The nitrogen-containing alkyd resin thus obtained has an average of 0.08 or more, preferably 0.1 to 3.0, average of carboxyl group and / or amino group functional groups in 1 kg of the resin.
If the number of the functional groups is less than 0.08 on average, the amount of epoxy resin that does not chemically bond to the nitrogen-containing alkyd resin increases, so that the storage stability of the paint is deteriorated, and gloss, adhesion to materials, corrosion resistance, and mechanical properties are reduced. This is not preferable because a coating film having poor chemical resistance and the like is formed. Also, the nitrogen-containing alkyd resin can have a number average molecular weight in the range of about 200-5000, preferably about 300-3000.

Next, the epoxy resin which is a modified resin of the nitrogen-containing alkyd resin is a polyepoxide having an average of two or more epoxy groups per molecule and an average of one or more per molecule obtained by modifying the polyepoxide with a monobasic acid. It is an epoxide having an epoxy group. Examples of the polyepoxide include an epoxy resin obtained from bisphenol and epihalohydrin, an epoxy resin obtained from hydrogenated bisphenol and epihalohydrin, or an epoxy resin obtained from bisphenol and β-epihalohydrin. Particularly preferred among these are epoxy resins obtained from bisphenol and epihalohydrin.Specifically, for example, as a trade name, manufactured by Shell Chemical Company, Epicoat 828, Epicoat 812, Epicoat 152, Epicoat 154, Epicoat 1001, Epicoat 1002 , Epicoat 1003, Epicoat 1055, Epicoat 1004, Epicoat 1007, Epicoat 1009, Epicoat
1010, Ciba Geigy's Araldite 6071, Araldite 6084, Araldite 6097, Araldite 6099, Araldite 7004, Dainippon Ink's Epicron N-730,
Epicron N-740 and the like.

Other than the above, a) polyglycidyl ether of novolak resin, b) polyglycidyl ether of polyhydric alcohol such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, c) adipic acid, phthalic acid, dimer acid, etc. D) alicyclic olefins, polyepoxides obtained by epoxidizing 1,2-polybutadiene, and the like. These polyepoxides are used together with the epoxy resin in a range that does not impair the corrosion resistance (generally, the epoxy resin 10
50 parts by weight or less with respect to 0 parts by weight).

As the monobasic acid for modifying the polyepoxide, for example, the fatty acid used in the nitrogen-containing alkyd resin can be used.

The mixing ratio of epoxy resin is 100% for nitrogen-containing alkyd resin.
The amount is about 1 to 50 parts by weight, preferably about 3 to 30 parts by weight based on parts by weight. If the compounding ratio is less than about 1 part by weight,
Coating properties such as adhesion to the material, corrosion resistance, chemical resistance, and flexibility are not sufficient.On the other hand, if the blending ratio is more than about 50 parts by weight, the pigment dispersibility is poor. This can cause defects such as color separation, gloss blurring, and the like. Separation of the pigment component from the resin component during the storage of the paint may occur, and the pigment component may settle to the bottom of the storage container and hard-caking, making re-dispersion difficult. Not preferred.

The epoxy resin-modified nitrogen-containing alkyd resin used in the present invention is usually prepared by reacting the nitrogen-containing alkyd resin and the epoxy resin at about 130 to 200 ° C. based on conventionally known reaction conditions (epoxy group and carboxyl group or amino group). It can be produced by continuing the addition reaction for 1 to 6 hours.

The curable coating material of the present invention comprises a solvent (or a dispersion medium, a diluent)
Can be applied to any of organic solvent systems mainly using an organic solvent and water systems mainly using water (may contain a small amount of organic solvent). According to these forms, the above epoxy resin-modified nitrogen-containing alkyd Preferably, a resin is prepared. That is, in the organic solvent system, the hydroxyl value is 30 to 200, particularly 3
It is preferable to adjust the acid value to 0 to 150, and the acid value to 30 or less.In an aqueous system, the hydroxyl value is 30 to 200, particularly 30 to 150, and the acid value is 10 to 200.
It is preferable to adjust to.

In addition, the epoxy resin-modified nitrogen-containing alkyd resin modified with a fatty acid (particularly a dry or semi-dry oil fatty acid) can form a cured coating film alone without blending the following crosslinkable resin.

The curable coating composition of the present invention can be crosslinked and cured in a three-dimensional network by heating and mixing a crosslinkable resin with the nitrogen-containing alkyd resin. The crosslinkable resin is a compound having a functional group (for example, a hydroxyl group, an alkyl ether group, an isocyanate group, etc.) that undergoes a cross-linking reaction with a hydroxyl group or the like in the nitrogen-containing alkyd resin. Specifically, there are a melamine resin, a urea resin, and a benzoguanamine resin, which are methylolated or modified with one or more selected from monohydric alcohols (having 1 to 5 carbon atoms). Examples of the isocyanate compound include tolylene diisocyanate, an adduct of tolylene diisocyanate and trimethylolpropane, diphenylmethane diisocyanate, methylene diisocyanate, hexamethylene diisocyanate, an adduct of hexamethylene diisocyanate and trimethylol propane, xylylene diisocyanate, and lysine diisocyanate. and so on. Further, the isocyanate group may be blocked with a blocking agent. Examples of the blocking agent include phenol, thiourea, methanol, propanol, n-butanol, t-butanol, ethyl acetoacetate, dimethyl malonate, and ε-caprolactam.

In the curable paint of the present invention, the mixing ratio of the epoxy resin-modified nitrogen-containing alkyd resin and the crosslinkable resin is based on the total amount of the epoxy resin-modified nitrogen-containing alkyd resin and the crosslinkable resin, and the epoxy resin-modified nitrogen-containing alkyd is used. Preferred is 95 to 60% by weight of resin, especially 85 to 70% by weight, 5 to 40% by weight of crosslinkable resin, especially 15 to 30% by weight.

The curable coating composition of the present invention is a liquid coating composition using an organic solvent and / or water as a solvent or a dispersion medium. In the case of an organic solvent system, the above resin is used as an ordinary organic solvent for coating, for example, toluene, xylene, naphtha, mineral spirit, Hydrocarbons such as octane and cyclohexane, alcohols such as methanol, ethanol, butanol, cyclohexanol and heptanol, ethers such as dioxane, methyl cellosolve, butyl cellosolve, methyl carbitol and butyl carbitol, ethyl acetate, butyl acetate and acetic acid It is obtained by dissolving or dispersing in ester solvents such as methyl cellosolve, cellosolve acetate and carbitol acetate, and ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone. In addition, the water-based paint may be obtained by converting the nitrogen-containing alkyd resin into a basic substance such as ammonia, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, diethylethanolamine, amine compounds such as morpholine, sodium hydroxide, and sodium hydroxide. And obtained by dissolving or dispersing them in water (which may contain an organic solvent).

The curable coating material of the present invention may contain, in addition to the above components, well-known coloring pigments, extender pigments, metallic pigments, anti-sagging agents, and curing accelerators.

Further, the curable coating of the present invention, brush coating, flow coating,
It can be applied by spray (air, airless) coating, electrostatic coating, dip coating, curtain flow coater, electrodeposition coating, etc. The non-volatile content of the coating at the time of coating is 10 to 70
Even a wide range of weight percent is acceptable. The coating film thickness is preferably 15 to 40 μm based on the dried coating film, and the coating film is cured normally or heated (usually at 10 to 40 ° C. at 100 to 200 ° C.).
Minutes). Examples of the object to be coated include an untreated metal, a metal surface-treated with a phosphate, a chromate, or the like, an object already coated with a primer, an intermediate coat, a top coat, a plastic (particularly, a polyamide resin), and a wood. , Glass and the like.

(Function and Effect of the Invention) In the present invention, the epoxy resin component in the epoxy resin-modified nitrogen-containing alkyd resin is chemically bonded to the nitrogen-containing alkyd resin, and the pigment dispersibility and the pigment dispersion stability of the nitrogen-containing alkyd resin component. Without deteriorating the properties, it exhibits the effect of reinforcing the corrosion resistance and mechanical properties of the nitrogen-containing alkyd resin component, and the effect is remarkable.

(Examples) Production examples, examples, and comparative examples of the epoxy resin-modified nitrogen-containing alkyd resin used in the present invention will be described below.

Production Example 1 7.3 parts by weight of ethylene glycol, 5.2 parts by weight of methylpropanolamine, 16.4 parts by weight of pentol, adipic acid 1
7.1 parts by weight, 24.3 parts by weight of isophthalic acid, tall oil fatty acid 1
A mixture consisting of 6.4 parts by weight and 3 parts by weight of xylene,
After reacting for about 12 hours at 160-230 ° C with stirring in a nitrogen gas atmosphere, mix 4.8 parts by weight of Epicoat 1001 and react for 4 hours at 160 ° C, then add 8.7 parts by weight of phthalic anhydride by half esterification At least, an epoxy-modified nitrogen-containing alkyd resin (A-1) used in the present invention was obtained. The resin (A-1) has a hydroxyl value of 70 and an acid value of 4
3, polybasic acid / polyhydric alcohol (molar ratio) is 0.9, alkanolamine content is 4.9% by weight, fatty acid content is 18.1
% By weight, and the epoxy content was 4.8% by weight.

Production Example 2 A mixture comprising 20.4 parts by weight of trimethylolpropane, 8.5 parts by weight of ethyldipropanolamine, 30.0 parts by weight of phthalic anhydride, 29.9 parts by weight of linseed oil, 16.7 parts by weight of Epikote 1004 and 3 parts by weight of xylene was prepared as described above. Example 1
To produce an epoxy-modified nitrogen-containing alkyd resin (A-2) used in the present invention. The resin (A
Regarding -2), the hydroxyl value is 45, the acid value is 8, the polybasic acid component / polyhydric alcohol component (molar ratio) is 0.95, the fatty acid content (oil length) is 30% by weight, and the alkanolamine content is 5.4.
% By weight and an epoxy content of 16.7% by weight.

Production Example 3 24.2 parts by weight of neopentyl glycol, 8.7 parts by weight of triethanolamine, 30.4 parts by weight of phthalic anhydride, 23.7 parts by weight of soybean oil fatty acid, 3 parts by weight of xylene, and Epicoat 1007
Was reacted in the same manner as in Production Example 1 to prepare an epoxy-modified nitrogen-containing alkyd resin (A-3) used in the present invention. The resin (A-3) has a hydroxyl value of 110, an acid value of 3, a polybasic acid component / polyhydric alcohol component (molar ratio) of 0.71, and a fatty acid content (oil length).
Is 30% by weight, alkanolamine content is 8.7% by weight,
The epoxy content was 13% by weight.

Production Example 4 A mixture consisting of 27.8 parts by weight of neopentyl glycol, 9 parts by weight of trimethylolpropane, 35 parts by weight of phthalic anhydride, 27.2 parts by weight of soybean oil fatty acid and 3 parts by weight of xylene was reacted in the same manner as in Production Example 1 and compared. Example alkyd resins were made.

Production Example 5 A mixture comprising 90 parts by weight of the alkyd resin, 100 parts by weight of triethanolamine and 3 parts by weight of xylene of Production Example 4 was reacted under the same conditions as in Production Example 1 and gelled during the reaction. The reaction was stopped.

Production Example 6 Production Example 1 was the same as Production Example 1 except that 3.5 parts by weight of ethylenediamine (the same mole number as methylpropanolamine) was used instead of 5.5 parts by weight of methylpropanolamine.
In the same manner as in the above, an epoxy-modified alkyd resin (A-4) for a comparative example of Production Example 6 was produced.

Examples and Comparative Examples Example 1 The resin (A-1) obtained in Production Example 1 was neutralized with diethylaminoethanol in an equivalent amount to obtain a water-soluble product, and then the resin (A-
1) 100 parts by weight (solid content) of a water-soluble methanol-modified melamine resin (Sumimar M-, manufactured by Sumitomo Chemical Co., Ltd.)
30W) 25 parts by weight (solid content), 124 parts by weight of titanium white pigment (manufactured by Teikoku Chemicals Co., Ltd., trade name JR-600E), butyl cellosolve and water are mixed, mixed and dispersed by a ball mill, and the non-volatile content is 50% by weight. % Of Paint 1 was prepared.

Example 2 Resin (A-2) 10 was added to resin (A-2) obtained in Production Example 2.
30 parts by weight of butoxymelamine resin (manufactured by Mitsui Toatsu Co., Ltd., trade name: Uban 20SE) per 20 parts by weight (solids), 20 parts by weight of sedimentable barium sulfate, Mapico Yellow XLO
20 parts by weight and a solvent (butanol, xylene) were blended and mixed by a sand mill to produce a colored coating material 2 having a dispersed nonvolatile content of 45% by weight.

Example 3, Comparative Example 1 Uban 20SE 25 parts by weight (solid content), carbon black 600E (Nagase Sangyo, trade name) 6.25 and solvent (iso Butanol, xylene), mixed and dispersed by a ball mill, and a colored paint 3 having a nonvolatile content of 55% by weight (comprising the nitrogen-containing alkyd resin of Production Example 3) and a colored paint 4 corresponding to Comparative Example 1 (Production Example) No. 4 alkyd resin).

Comparative Example 2 In Example 1, resin (A) was used instead of resin (A-1).
A colored paint 5 corresponding to Comparative Example 2 was produced in the same manner as in Example 1 except that the same amount of -4) was used.

Performance Test Results The colored paints 1 to 5 obtained in the above Examples and Comparative Examples were applied to an iron plate surface-treated with iron phosphate, and various coating film performance tests were performed on a coated plate which was cured by heating. It was as shown in the table.

(* 1) Painted surface condition: visually determined. Smoothness, cissing,
The presence or absence of dents was examined.

(* 2) Corrosion resistance: Cross-cut the coating film to reach the substrate, test with salt spray for 360 hours, apply adhesive cellophane tape to the cut part, remove it, and apply from the cut part The peel widths on both sides of the film were examined.

(* 3) Acid resistance: An N / 10 sulfuric acid aqueous solution was dropped on a horizontally supported coating surface, and the coating surface condition after standing for 48 hours was examined. ○ indicates that no abnormality was observed.

(* 4) Alkali resistance: Performed in the same manner as above (* 3) except that an aqueous solution of N / 5 sodium hydroxide was used. ○ indicates that no abnormality was observed at all, and △ indicates that occurrence of whitening and gloss was observed.

(* 5) Bending resistance: Curvature radius 4mm, with the coating on the outside
The state of the coated surface when bent in was examined. ○ indicates that no abnormality was observed, and △ indicates that cracks and peeling were observed.

(* 6) Solvent resistance: The coated surface was examined after immersing the coated plate in toluene (20 ° C.) for 5 hours. ○ indicates that no abnormality was observed.

(* 7) Adhesion: The coated plate was immersed in water at 40 ° C. for 48 hours, pulled up and allowed to stand for 1 hour, and then cut with a gouge as in (* 8) to examine the adhesion.

(* 8) Recoatability: Apply each colored paint to the iron plate so that the cured film thickness is 30μ, bake it at 180 ° C for 30 minutes, and apply the same paint again so that the cured film thickness is 20μ. ,
Rebaking was performed at 120 ° C. for 30 minutes.

Next, the coating film was reached with a razor to reach the substrate,
One hundred (1 × 1 mm) squares were made, an adhesive cellophane tape was adhered to the surface thereof, and the number of remaining squares after peeling was measured.

(* 9) Storage property: The colored paint stored at 40 ° C for 20 days was tested. The paint state was determined by examining the presence or absence of pigment sedimentation. ○ indicates that no abnormality was observed, and Δ indicates that pigment sedimentation was clearly observed.

Claims (1)

(57) [Claims] An alkanolamine compound having one hydroxyl group and a primary amino group or a secondary amino group in one molecule and / or a polyhydric alkanolamine compound having two or more hydroxyl groups in one molecule. Curing characterized by using an epoxy resin-modified nitrogen-containing alkyd resin obtained by modifying a nitrogen-containing alkyd resin obtained by subjecting a polyhydric alcohol and a fatty acid to a condensation reaction with an epoxy resin, if necessary, as a vehicle component. Paint