JPS6310673A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition which gives a film having excellent adhesive strength, impact strength, etc., by mixing a thermosetting resin, a metal powder, and a chelating agent which can be dissolved in the above- mentioned resin homogeneously at ordinary temperature and has a stability constant with the metal powder higher than a specified value. CONSTITUTION:An objective coating composition is obtained by mixing a thermosetting resin (A) such as a bisphenol A epoxy resin or a polyester resin, a metal powder (B) (e.g., a magnesium powder or a titanium powder), and a chelating agent (C) which can be dissolved in component A homogeneously at ordinary temperatures and has a stability constant with component B of 5 or greater. Examples of the chelating agent include ethylenediaminetetraacetic acid and salicylic acid. The suitable proportions of the components are 100pts.wt. component A, 5-400pts.wt. component B, and 0.1-20pts.wt. component C. The term stability constant refers to a stability constant value determined at ordinary temperature on an aqueous solution of an ionic strength of 0.1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a coating composition, and more particularly to a coating composition having excellent impact resistance.

[Conventional technology]

BACKGROUND OF THE INVENTION Various coating compositions have been used in a wide range of fields, and one of them is a coating composition using a thermosetting resin as a binder component.

Coating compositions using this type of thermosetting resin effectively utilize various properties inherent in the thermosetting resin, and have many advantages. However, due to recent rapid advances in technology, coating compositions using this type of thermosetting resin are now required to have even more advanced performance in various properties, particularly in terms of adhesion strength and impact resistance of the coating film. There is a strong demand for improved strength.

[Problem that the invention seeks to solve]

The problem to be solved by the present invention is to meet the above-mentioned demands for this type of thermosetting resin coating composition, and more specifically, to improve the adhesion strength and impact resistance of the coating composition. It is a matter of further improvement.

[Means for solving problems]

This problem can be solved by using, as a coating composition, a composition in which a thermosetting resin is blended with a metal powder and a chelating agent having a stability constant of 5 or more with respect to the metal powder.

[Structure and operation of the invention]

The coating composition of the present invention basically comprises (a) a thermosetting resin, (b) a metal powder, preferably 5 to 400 parts by weight of metal powder per 100 parts by weight of the resin, and (c) The chelating agent has a stability constant of 5 or more with the metal powder, preferably 0.1 to 20 parts by weight per 100 parts of the resin.

In this specification, "stability constant" refers to the stability constant value log, K M^ (for example, [metal chelate]) measured at room temperature (25°C) for an aqueous solution with an ionic strength of 0.1.
Published by Nankodo (see Sakaro Takeshi-1 Ueno Keiheiba)).

As the thermosetting resin as the base resin used in the present invention, the thermosetting resins conventionally used for paints can be widely used as they are. Examples of such resins include epoxy resins, polyester resins, and acrylic resins. More specifically, epoxy resins include substituted or unsubstituted glycidyl groups (e.g., glycidyl ether, glycidyl ester, glycidyl amine, glycidyl imine) represented by the following formula (where Z represents a hydrogen atom, a methyl group, or an ethyl group). etc.) in the molecule at least 1
For example, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, epoxy resin of phenol novolak, diglycidyl ether of alkylene oxide adducts of bisphenols, etc. can be used. There is no particular restriction on the equivalent, but preferably the epoxy equivalent is 2
A value of about 00 to 1000 is good.

As these curing agents, those that are normally n-soluble in water and have the ability to replace water molecules can be used, such as aliphatic amines, aromatic amines, alicyclic amines, polyamide amines, and polymer captans. , ketimine, etc. These curing agents may be used alone or in combination of two or more, and together with this underwater curing agent, a room temperature curing agent that is normally used in the atmosphere can also be used. Examples include polyamines, polyamidoamines, amine-containing adducts, and separated adducts. The amount of these curing agents used is also sufficient as the amount used as a normal curing agent, and the active hydrogen equivalent of the amino group is usually about 0.5 to 2.5 equivalents per equivalent of the epoxy group.

As the polyester resin, unsaturated dibasic acids or those obtained by substituting a part of them with saturated dibasic acids, and those obtained by dehydration condensation from dihydric alcohols can be used.
It can be used by dissolving it in a vinyl monomer if necessary.

Examples of unsaturated dibasic acids and saturated dibasic acids include maleic anhydride, fumaric acid, itaconic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, 3
．． 6-Nindomethylenetetrahydrophthalic anhydride, adipic acid, sebacic acid, tetrachlorophthalic anhydride, 3,
6-Nindo dichloromethylenetetrachlorophthalic acid, etc. can be used.

Examples of dihydric alcohols include ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, hydrogenated hisphenol A, and 2.2
-bis(4-oxyethoxyphenyl)propane, 2.
2-bis(4-oxypropoxyphenyl)propane and the like can be used.

As the vinyl monomer, styrene, vinyltoluene, diallyl phthalate, methyl methacrylate, triallylphosphoric acid, triallylphosphoric acid, etc. can be used.

Unsaturated polyester 10 as curing catalyst and accelerator
0.1 to 3 parts by weight of peroxides such as methyl ethyl ketone peroxide, hensyl bar oxide, and couschalybutyl barbenzoate, alone or in combination, and cobalt naphthenate, cobalt octenoate as accelerators, per part 0ffi. , copper naphthenate, dimethylaniline, etc. can be used.

Acrylic resins typically have a structure represented by the following formula: ■C)+2=C-O- (Z represents a hydrogen atom or a methyl group) in the molecule (typically one structure). Examples include ethyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, indecyl methacrylate, lauryl methacrylate, stearyl methacrylate, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl Methacrylate, 2-hydroxyethyl acrylate, dimethylaminomethyl methacrylate, noethylaminoethyl methacrylate, ethylene glycol methacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, n-butoxyethyl methacrylate, tetrahydrofurfuryl acrylate, Tetrahydrofurfuryl acrylate, glycidyl methacrylate,
Tetraethylene glycol dimethacrylate, 1.3-
Butanediol dimethacrylate, mono (2-methacryloyloxyethyl) acid phosphate, mono (
2-acryloyloxyethyl) acid phosphate,
Ethyl carpitol acrylate, methyl triglycol acrylate, tetrahydrofurfuryl acrylate, 2
-Hydroxy-3-phenyloxypropyl acrylate, trimethylolpropane triacrylate, 1.6
-Hexanediol diacrylate, 2-hydroxyethyl acryloyl phosphate, butoxyethyl acrylate, lauryl acrylate, stearyl acrylate, triethylene glycol diacrylate, neopentyl glycol diacrylate, phenol derivative acrylate, etc. can be used.

Curing catalysts and accelerators used alone or in combination as required include peroxides such as methyl ethyl ketone peroxide, benzoyl peroxide, tert-butyl perbenzoate alone or in combination, and cobalt naphthenate, octenoic acid as accelerators. cobalt,
Copper naphthenate, dimethylaniline, etc. can be used.

The coating composition of the present invention contains 0% per 100 parts by weight of the resin.
．． 1 to 20 parts by weight, preferably 0.5 to 20 parts by weight,
It is necessary to blend into the resin one or more chelating agents that uniformly melt at room temperature and have a stability constant with the metal powder of 5 or more, preferably 10 or more. In this case, uniformly dissolving in the resin includes uniformly dissolving in the resin alone, and uniformly dissolving in a resin composition in which the resin is blended with other additives. Suitable chelating agents for use in the present invention include malonic acid, ethylmalonic acid, diethylmalonic acid, dimethylmalonic acid, di-n-propylmalonic acid, isopropylmalonic acid, methylmalonic acid, propylmalonic acid. Malonic acid-based chelating agents such as ethylenediamine, N,■-dimethylethylenediamine, N,N'-dimethylethylenediamine, N,
N'-diethylethylenediamine, diethylenetriamine, triethylenetetramine, trimethylenediamine,
β, β.

β-triaminotriethylamine, propylene diamine, 1,2,3-triaminopropane, α.

Amine chelating agents such as α'-dipyridyl, phenanthroline, 5-chloro-1,10-phenanthroline,
5-nitro-1,10-phenanthroline, 5-methyl-1,10-phenanthroline, 5-phenyl-1,1
Phenanthroline chelating agents such as 0-phenanthroline, alanine, β-alanine, glycylalanine, asparagine, aspartic acid, glycine, glycylglycine, glycylglycylglycine, histidine, leucine, methionine, phenylalanine, proline, serine, tryptophan , amino acid chelating agents such as valine, β-alanine-N, N-diacetic acid, aminobarbital acid-N, N-diacetic acid, 2-aminobenzoic acid-N, N-
Diacetic acid, 2-phosphoethylimino-N, N-diacetic acid, aminomethylphosphonic acid-N.

N-diacetic acid, iminodiacetic acid, iminodipropionic acid, ammoniatriacetic acid, 1,2-diaminocyclohexane-
N1M-tetraacetic acid, 1,3-diaminocyclohexane-N,N'-tetraacetic acid, ethylenediamine-N,N
'-Diacetic acid, ethylenediaminetetraacetic acid, N-benzylethylenediaminetriacetic acid, N-butylethylenedi7
Mint triacetic acid, N-cyclohexylethylenediaminetriacetic acid, ethylenediaminedipropionic acid, ethylenediaminetetrapropionic acid, glycine-N-propionic acid, trimethylenediaminetetraacetic acid, tetramethylenediaminetetraacetic acid, citric acid, salicylic acid, 5-sulfosalicylic acid, pyrroline acid, acid-based chelating agents such as tetrametaphosphoric acid, trimetaphosphoric acid, triphosphoric acid, oxalic acid, succinic acid, salicylaldehyde, 3-chlorsalicylaldehyde, 5-chlorsalicylaldehyde, 4,6-
Dimethylsalicylaldehyde, 3-ethoxysalicylaldehyde, 3-fluorosalicylaldehyde, 4-methoxysalicylaldehyde, 5-methylsalicylaldehyde, 3-nitrosalicylaldehyde, 4-nitrosalicylaldehyde, 5-nitrosalicylaldehyde, 3- n
-Propylsalicylaldehyde, 5-sulfosalicylaldehyde, 2-oxy-1-naphthaldehyde, 2-oxy-3-naphthaldehyde, β-diketone, acetylacetone, benzoylacetone, benzoyltrifluoroacetone, dibenzoylmethane, 1.3 -Disilylpropanedione-1.3, bis(thenoyl)methane, furoylacetone, 2-furoylbenzoylmethane, 2-furoyltrifluoroacetone, hexafluoroacetylacetone, C-methylacetylacetone, β-naphthoyltrifluoroacetone Ruacetone, 1-silylbutadione-1,
Aldehydes such as 3,2-thenoylacetone, 2-thenoylbenzoylmethane, 2-thenoyl-2-furoylmethane, thenoyltrifluoroacetone, trifluoroacetylacetone, acetone, methane-based chelating agents, and others such as 1.8- Phenol derivatives such as dioxynaphthalene-3,6-disulfonic acid, catechol-3゜5-disulfonic acid, 8-oxyquinoline, Eriofrom Blank T, Eriofrom Black A, Eriofrom Blue Black B, Eriofrom Blue Black 0 of R etc.
There are 0-dioxyazo dyes, as well as 0-aminobenzenethiol, O-aminophenol, and the like.

The metal powder blended into the composition of the present invention can be used as long as its ionization tendency is between magnesium and palladium. Such metal powders include magnesium powder, titanium powder, aluminum powder, zinc powder, chromium powder, zirconium powder, iron powder, nickel powder, tin powder, lead powder, copper powder, silver powder,
There are palladium powders or alloy powders of these, and one of them is
One species or two or more species may be used. Among these, particularly preferred are zinc powder, aluminum powder and iron powder.

The particle size of the powder may be as long as the average particle size is 300 μm or less,
If it exceeds 300 .mu.m-t-, the appearance of the coating film will deteriorate and is therefore unsuitable. The effect on impact resistance is the same regardless of the shape of the powder, such as flat, spherical, or acicular. Preferably 5 to 400 parts by weight, particularly preferably 10 to 300 parts by weight per 100 parts by weight of the curable resin
Add within the range of parts by weight. If it is less than 5 parts by weight, sufficient effect in improving impact resistance may not be exhibited;
If the amount added exceeds 0 parts by weight, the cohesive force of the composition and the adhesion to the grassland tend to decrease.

The metal powder may be mixed in advance with the thermosetting resin compounding system, or may be added when the thermosetting resin compounding system is mixed and cured.

In the coating composition of the present invention, the thermosetting resin and the chelating agent blended into the composition act on the gold powder in the composition to form a coating film with extremely excellent impact resistance.

In addition, in the present invention, fillers can be used together,
By using this filler, effects such as viscosity adjustment, thickness adjustment and uniformity of the coating film, improvement in leveling, improvement in mechanical strength after curing, stress relaxation, etc. can be expected. A wide variety of fillers are used at this time, such as talc, calcium carbonate, clay, bentonite, carbon black, and white carbon. It is used in an amount of 0 to 300 parts by weight per 100 parts by weight of the synthetic resin.

Various other additives can be used in conjunction with the present invention as necessary, and specific examples of the additives in this case include diluents, solvents, coloring pigments, antirust pigments, etc. .

〔Example〕

EXAMPLES The present invention will be specifically described below with reference to Examples. However, in the following examples, parts indicate parts by weight.

Example 1 Bisphenol A type epoxy resin (epoxy 1190
) 100 parts, phenyl glycidyl ether 10 parts, ethylenediaminetetraacetic acid (chelating agent, stability constant log with iron, K i = 14, stability constant lo with zinc
g, l^-16) 2 parts, zinc powder (average particle size 3 μm)
150 parts of polyamide amine (amine value: 345), and 2 parts of colloidal silica were mixed in a stirring pot at 30°C to obtain an epoxy resin composition. This composition was applied to a steel plate to a dry film thickness of 300 μm, and the impact strength after curing was measured. The results are shown in Table 1 below.

Example 2 31.4 parts of propylene glycol was placed in a reaction vessel and the temperature was 80~
Preheat to 100°C, add 18.4 parts of maleic anhydride,
Add 27.8 parts of phthalic anhydride and gradually raise the temperature to 16
The reaction was carried out at 0°C for about 4 hours and then at 200°C for about 4 hours. During this time, carbon dioxide gas is passed through the mixture while stirring. The progress of the reaction is tracked using the acid value, and when the acid value of the resin drops to 30-50, the reaction is terminated, a polymerization inhibitor is added and the resin is transferred to a dissolution tank, and the resin is cooled to 60-70°C. Add 30.0 parts of styrene and mix.

For 100 parts of the base resin produced in this way, ethylenediaminetetra-acetic acid @ (chelating agent, mentioned above)
5 parts of iron powder (average particle size: 40 μm), 2 parts of colloidal silica, 0.8 parts of MEK peroxide, and 0.8 parts of cobalt naphthenate were mixed to obtain a thermosetting resin composition. A test similar to that in Example 1 was conducted using this composition.

Example 3 In Example 1, salicylic acid (chelating agent, stability constant log with iron) was used instead of ethylenediaminetetraacetic acid.
, K rI^=17, stability constant log with zinc, K
The test was conducted in the same manner except that M^=10) was used.

Comparative Example 1 The same tests as in Example 1 were conducted on the same thermosetting resin composition as in Example 1 except that it did not contain ethylenediaminetetraacetic acid.

Comparative Example 2 The same test as in Example 1 was conducted on the same thermosetting resin composition as in Example 2 except that it did not contain ethylenediaminetetraacetic acid.

Table 1 However, the methods for measuring the physical properties in Table 1 are as follows.

0#H plate: 9X100X100ms Dull steel plate 0 Impact strength after hardening: A painted sample left at room temperature for 6 months was tested using a B method impact tester specified in JIS-5400, with a direct diameter of 172 inches. The test is conducted using a striking core and a load of 500 g. The impact resistance is evaluated at the lowest height at which cracking or peeling occurs, reaching the substrate under the coating.

(that's all)

Claims (3)

[Claims] (1) A coating composition comprising a thermosetting resin, a metal powder, and a chelating agent that dissolves uniformly in the resin at room temperature and has a stability constant of 5 or more with the metal powder. (2) The coating composition according to claim 1, wherein the chelating agent is blended in an amount of 0.1 to 20 parts by weight based on 100 parts by weight of the resin. (3) The coating composition according to claim 1, wherein the metal powder is blended in a proportion of 5 to 400 parts by weight based on 100 parts by weight of the resin.