JP2007270095A - Coating composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating composition suppressing degradation/deterioration of an organic constituent for a long period of time, even if the coating composition contains an inorganic powder particle as a coating constituent; and having an excellent weather resistance. <P>SOLUTION: The coating composition includes a bonding material containing an organic synthetic resin having a piperidine group, and an inorganic powder particle with a compound having an alkoxysilyl group and a piperidine group coated thereon. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a coating composition having excellent weather resistance.

The outer walls and roofs of buildings such as houses and buildings are usually coated with paint, which protects the buildings from wind and rain, direct sunlight, and maintains the aesthetics of the buildings.
Such paints are required to have performance such as weather resistance against wind and rain and direct sunlight.

  On the other hand, for example, Patent Document 1 uses a synthetic resin emulsion obtained by polymerizing a polymerizable UV-stable monomer having a piperidine group and a polymerizable unsaturated group in the molecule as a binder. Thus, it is described that a coating film having excellent weather resistance is obtained.

Japanese Patent Laid-Open No. 3-128978

  However, many of the commonly used paints are composed of a binder containing an organic synthetic resin and the like, an inorganic powder such as an inorganic pigment, etc., and in some cases, the inorganic powder may be an organic synthetic resin or the like. As a result, the organic components may be adversely affected on the performance such as weather resistance of the formed coating film.

  The present invention aims to further improve / improve the decomposition / degradation of organic components, and even if inorganic powders are contained as paint constituents, the decomposition / degradation of organic components over a long period of time. The object is to obtain a coating film having excellent weather resistance.

  As a result of intensive studies to solve the above problems, the inventors of the present application have found that a binder containing an organic synthetic resin having a piperidine group and an inorganic powder coated with a compound having an alkoxysilyl group and a piperidine group are coated. It has been found that a coating composition containing a body can suppress decomposition and deterioration of an organic synthetic resin, and a coating film having excellent weather resistance can be obtained, and the present invention has been completed.

That is, the present invention includes the following features.
1. A binder comprising an organic synthetic resin having a piperidine group;
A coating composition comprising an inorganic granular material coated with a compound having an alkoxysilyl group and a piperidine group.

  The coating composition of the present invention can form a coating film having excellent weather resistance.

  Hereinafter, the best mode for carrying out the present invention will be described in detail.

  The coating composition of the present invention comprises a binder containing an organic synthetic resin having a piperidine group, and an inorganic powder coated with a compound having an alkoxysilyl group and a piperidine group. is there.

  In the present invention, an inorganic powder is coated with a compound having an alkoxysilyl group and a piperidine group, and by using an organic synthetic resin having a piperidine group as a binder, a formed coating film having excellent weather resistance can be obtained. It is obtained.

In general, in inorganic powders such as titanium oxide, radicals are generated by ultraviolet rays, visible light, etc., and the organic components are decomposed and deteriorated by the radicals, which adversely affects the weather resistance of the coating film.
In the present invention, the inorganic powder is coated with a compound having an alkoxysilyl group and a piperidine group so that the alkoxysilyl group adheres firmly to the inorganic powder, and the radical generated by the piperidine group from the inorganic powder It is possible to suppress decomposition and degradation of organic components due to radicals. In addition, by introducing a piperidine group into the binder, it is possible to synergistically suppress the decomposition and deterioration of the organic component due to radicals.

The binder in the present invention is not particularly limited as long as it contains an organic synthetic resin having a piperidine group.
As such an organic synthetic resin, for example,
(1) A method in which a polymerizable monomer and a compound having a piperidine group (hereinafter also referred to as “component (A)”) are mixed and polymerized,
(2) It can be obtained by a method of introducing a compound having a piperidine group into an organic synthetic resin obtained by polymerizing a polymerizable monomer, or a method of using the methods (1) and (2) in combination.

Examples of the compound (component (A)) having a piperidine group in the methods (1) and (2) include:
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) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-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-crotonoyloxy-2,2,6,6-piperidine group such as tetramethylpiperidine polymerizable unsaturated compound having a bond,
4-hydroxy-1,2,2,6,6-pentamethylpiperidine (same as 1,2,2,6,6-pentamethyl-4-piperidinol), 4-hydroxy-2,2,6,6-tetra Methylpiperidine, 3-hydroxy-1,2,2,6,6-pentamethylpiperidine, 2,4-bis {N-butyl-N- (1-cyclohexyloxy-2,2,6,6-tetratetramethyl) Piperidin-4-yl) amino} 6- (2-hydroxyethylamine) 1,3,5-triazine, bis (1,2,2,6,6-pentamethyl-4-piperidyl) {(3,5-bis ( 1,1-dimethylethyl) -4-hydroxyphenyl) methyl} butyl malonate, 4-amino-2,2,6,6-tetramethylpiperidine, 3-amino-2,2,6,6-tetramethylpiperidine Piperidine groups and reactive functional groups such as Compound, and the like.

As the polymerizable monomer in the methods (1) and (2),
3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, vinyltrimethoxycissilane, vinyltriethoxysilane Alkoxysilyl group-containing monomers such as vinyltriisopropoxysilane;
Carboxyl group-containing monomers such as (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, isocrotonic acid, salicylic acid, cinnamic acid,
(Meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxymethyl, (meth) acrylic acid-2-hydroxypropyl, (meth) acrylic acid-3-hydroxypropyl, (meth) acrylic acid- 2-hydroxybutyl, 4-hydroxybutyl (meth) acrylate, ethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, glycerol mono (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meta ) Acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polyethylene glycol allyl ether, polypropylene glycol allyl ether, polyethylene glycol-polypropylene glycol Hydroxyl group-containing monomers such as ruaryl ether, N-methylol (meth) acrylamide, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylate-n-propyl, (Meth) acrylic acid-i-butyl, (meth) acrylic acid-n-butyl, (meth) acrylic acid-sec-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid-2-ethylhexyl, (meth) Acrylic acid-n-hexyl, octyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, trifluoroethyl (meth) acrylate , N-amyl (meth) acrylate, isoamyl (meth) acrylate, (meth) acryl Oxyl acid, decyl (meth) acrylate, dodecyl (meth) acrylate, dodecenyl (meth) acrylate, octadecyl (meth) acrylate, phenyl (meth) acrylate, isobornyl (meth) acrylate, (meth) acrylic acid (Meth) acrylic acid ester monomers such as benzyl, 2-phenylethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, and 4-methoxybutyl (meth) acrylate;
Cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, hydroxymethylcyclohexyl (meth) acrylate, cyclooctyl (meth) acrylate, cyclodecyl (meth) acrylate, cyclo Cycloalkyl group-containing monomers such as dodecyl (meth) acrylate and 4-tert-butylcyclohexyl (meth) acrylate;
T-butyl (meth) acrylate, t-amyl (meth) acrylate, tripropylmethyl (meth) acrylate, triisopropylmethyl (meth) acrylate, tributylmethyl (meth) acrylate, tri (meth) acrylate T-alkyl group-containing monomers such as isobutylmethyl, tri-t-butylmethyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate;
Aminomethyl (meth) acrylate, aminoethyl (meth) acrylate, aminopropyl (meth) acrylate, aminobutyl (meth) acrylate, butylvinylbenzylamine, vinylphenylamine, p-aminostyrene, (meth) acrylic Acid-N-methylaminoethyl, (meth) acrylic acid-Nt-butylaminoethyl, (meth) acrylic acid-N, N-dimethylaminoethyl, (meth) acrylic acid-N, N-dimethylaminopropyl, (Meth) acrylic acid-N, N-diethylaminoethyl, (meth) acrylic acid-N, N-dimethylaminopropyl, (meth) acrylic acid-N, N-diethylaminopropyl, N- [2- (meth) acryloyloxy Ethyl] piperidine, N- [2- (meth) acryloyloxyethyl] pyrrolidine, N- [ - (meth) acryloyloxyethyl] morpholine, 4- [N, N-dimethylamino] styrene, 4- [N, N-diethylamino] styrene, 2-vinylpyridine, amino group-containing monomers such as 4-vinylpyridine;
(Meth) acrylic acid glycidyl, diglycidyl fumarate, (meth) acrylic acid-3,4-epoxycyclohexyl, 3,4-epoxyvinylcyclohexane, allyl glycidyl ether, (meth) acrylic acid-ε-caprolactone-modified glycidyl, Glycidyl group-containing monomers such as (meth) acrylic acid-β-methylglycidyl;
(Meth) acrylamide, ethyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-cyclopropyl (meth) acrylamide, N- (meth) ) Acroylpyrrolidine, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-methyl-N-ethyl (meth) acrylamide, N-methyl-N-isopropyl (meth) acrylamide, N -Methyl-Nn-propyl (meth) acrylamide, N-methylol (meth) acrylamide, N- [3- (dimethylamino) propyl] (meth) acrylamide, vinylamide, N, N-methylenebisacrylamide, diacetone (meta ) Acrylamide, N-methyl - Le (meth) amide group-containing monomers such as acrylamide;
Diacetone (meth) acrylate, diacetone (meth) acrylamide, acrolein, vinyl methyl ketone, vinyl ethyl ketone, vinyl (iso) butyl ketone, acetonyl acrylate, acryloxyalkylpropanals, methacryloxyalkylpropanals, 2-hydroxypropyl Carbonyl group-containing monomers such as acrylate acetyl acetate, tandiol acrylate acetyl acetate, acetoacetoxyethyl (meth) acrylate, and acetoacetoxyallyl ester;
Isocyanate group-containing monomers such as methacryloyl isocyanate;
Oxazoline group-containing monomers such as vinyl oxazoline, 2-vinyl-2-oxazoline, 2-propenyl 2-oxazoline;
Hydrazino group-containing monomers such as propylene-1,3-dihydrazine and butylene-1,4-dihydrazine;
Acetoacetoxyl group-containing monomers such as acetoacetoxyethyl (meth) acrylate and acetoacetoxyallyl ester;
Nitrile group-containing monomers such as acrylonitrile and methacrylonitrile;
Methylol group-containing monomers such as N-methylol (meth) acrylamide;
Vinylidene halide monomers such as vinylidene fluoride;
Aromatic vinyl monomers such as styrene, 2-methylstyrene, chlorostyrene, vinyltoluene, t-butylstyrene, vinylanisole, vinylnaphthalene;
Sulfonic acid-containing monomers such as styrene sulfonic acid and vinyl sulfonic acid;
2-hydroxy-4- (meth) acryloxybenzophenone, 2-hydroxy-5- (meth) acryloxybenzophenone, 2-hydroxy-4-{(meth) acryloxy-ethoxy} benzophenone, 2-hydroxy-4-{( Benzophenone monomers such as (meth) acryloxy-diethoxy} benzophenone, 2-hydroxy-4-{(meth) acryloxy-triethoxy} benzophenone;
2- {2′-hydroxy-5 ′-(meth) acryloxyethylphenyl} -2H-benzotriazole, 2- {2′-hydroxy-5 ′-(meth) acryloxyethyl-3-t-butylphenyl} Benzotriazole such as -2H-benzotriazole, 3- (meth) acryloyl-2-hydroxypropyl-3- {3 '-(2 "-benzotriazole) -4-hydroxy-5-t-butyl} phenylpropionate System monomers;
Other monomers such as ethylene, propylene, isoprene, butadiene, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl versatate, vinyl ether, vinyl ketone;
Of these, one or more of these can be used and can be set as appropriate.

  Although it does not specifically limit as a polymerization method in the method of (1) and (2), What is necessary is just to superpose | polymerize by well-known polymerization methods, such as emulsion polymerization, dispersion polymerization, and solution polymerization. As polymerization additives, water, emulsifiers, initiators, solvents, dispersants, emulsion stabilizers, polymerization inhibitors, polymerization inhibitors, buffers, crosslinking agents, pH adjusters, chain transfer agents, catalysts, etc. A necessary amount can be added according to various polymerization methods and purposes.

In the method (2), an organic compound having a piperidine group is produced by reacting a reactive functional group present in the organic synthetic resin with a component (A) having a reactive functional group that reacts with the reactive functional group. A synthetic resin can be obtained.
Examples of combinations of such reactive functional groups include hydroxyl groups and isocyanate groups, amino groups and isocyanate groups, amino groups and glycidyl groups, amino groups and glycidyl groups, carboxyl groups and glycidyl groups, carboxyl groups and amino groups, and carboxyl groups. Groups and carbodiimide groups, carboxyl groups and aziridine groups, carboxyl groups and oxazoline groups, carbonyl groups and hydrazide groups, acetoacetoxyl groups and amino groups, alkoxysilyl groups and carboxyl groups, alkoxysilyl groups and hydroxyl groups, and reactive silyl groups Etc.
The reaction method is not particularly limited, and the reaction may be performed by a conventional method, and a catalyst or the like may be used as necessary.

  The binding material of the present invention includes an organic synthetic resin having a piperidine group, and the content of the piperidine group is a compound having a piperidine group (component (A)) with respect to the total amount of the binding material (solid content). 0.1 wt% to 80 wt% (preferably 0.5 wt% to 50 wt%).

  The inorganic particles used in the present invention are coated with a compound having an alkoxysilyl group and a piperidine group.

  Examples of inorganic powders include titanium oxide, zinc oxide, niobium oxide, tantalum oxide, zirconium oxide, cerium oxide, tungsten oxide, tin oxide, bismuth oxide, copper oxide, iron oxide, nickel oxide, chromium oxide, and hafnium oxide. , Ruthenium oxide, cerium oxide, aluminum oxide, antimony oxide, silicon oxide, magnesium oxide, molybdenum sulfide, tungsten sulfide, cadmium sulfide, tantalum nitride, strontium titanate, barium titanate, gallium arsenide, gallium phosphide, indium phosphide, niobic acid Potassium, bismuth vanadate, silicon carbide, carbon black, molybdenum red, cobalt blue, manganese violet, dial, bitumen, ultramarine, etc.

Although the compound which has the alkoxy silyl group and piperidine group which coat | covers such an inorganic granular material is not specifically limited, For example, it can obtain by the following methods.
(3) A method obtained by polymerizing a compound having a piperidine group and a polymerizable unsaturated bond, and a compound having an alkoxysilyl group and a polymerizable unsaturated bond,
(4) a method obtained by reacting a compound having a piperidine group and a reactive functional group with an alkoxysilyl group and a compound having a functional group capable of reacting with the reactive functional group,
Or it can obtain by the method of using the method of (3) and (4) together.

  Examples of the compound having an alkoxysilyl group and a polymerizable unsaturated bond in the method (3) include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropyltriethoxysilane. , 3-methacryloxypropylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane and the like.

  Examples of the compound having a piperidine group and a polymerizable unsaturated bond in the method of (3) include those mentioned above, such a compound having a piperidine group and a polymerizable unsaturated bond, an alkoxysilyl group, and a polymerizable unsaturated bond. A compound having a piperidine group and an alkoxysilyl group can be obtained by mixing the compound having a saturated bond, and further mixing the above-described ethylenically unsaturated monomer and polymerizing by a conventional method.

Examples of the compound having a piperidine group and a reactive functional group in the method (4) include those mentioned above.
Further, the compound having an alkoxysilyl group and a reactive functional group in the method (4) is not particularly limited, but the alkoxysilyl group preferably has 8 or less carbon atoms, preferably 5 or less carbon atoms. Examples of the compound having an alkoxysilyl group and a polymerizable unsaturated bond include 3-isocyanatepropyltrimethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, and 3-isocyanatepropylmethyldiethoxysilane. Etc.

Examples of combinations of reactive functional groups in the method (4) include, for example, hydroxyl group and isocyanate group, amino group and isocyanate group, amino group and glycidyl group, carboxyl group and glycidyl group, carboxyl group and amino group, and carboxyl group. Examples include carbodiimide group, carboxyl group and aziridine group, carboxyl group and oxazoline group, carbonyl group and hydrazide group, acetoacetoxyl group and amino group, and the combination of hydroxyl group and isocyanate group, amino group and isocyanate group is particularly preferable. .
Particularly in the method (4), a combination of a compound having a piperidine group and a hydroxyl group, a compound having an isocyanate group and an alkoxysilyl group, a compound having a piperidine group and an amino group, and a compound having an isocyanate group and an alkoxysilyl group The combination of is preferable.

A compound having a piperidine group and an alkoxysilane group can be obtained by reacting such a compound having a piperidine group and a reactive functional group with a compound having an alkoxysilyl group and a reactive functional group.
The reaction temperature in such a reaction is usually preferably about 30 to 150 ° C.
In addition, a reaction catalyst can be added to promote the reaction. Although it does not specifically limit as a reaction catalyst, What is necessary is just to select suitably by the combination of the reactive functional group mentioned above.
Furthermore, the compound which has the target piperidine group and alkoxysilane group can be obtained by adjusting the compound mentioned above, reaction ratio, etc. suitably.

  The method for coating the inorganic particle surface with a compound having an alkoxysilyl group and a piperidine group is not particularly limited, but a method of mixing and drying a compound having an inorganic particle, an alkoxysilyl group and a piperidine group In addition, the surface of the inorganic powder can be easily coated by a method of spraying and drying a compound having an alkoxysilyl group and a piperidine group with a spray or the like.

As a mixing method, mixing can be performed using a homomixer, a magnetic stirrer, a ball mill, a sand mill, a high-speed rotary mill, a jet mill, or the like.
As a drying method, for example, hot air drying, vacuum drying, direct heating drying, high-frequency heating drying, far-infrared heating drying, dehumidification drying, and the like can be employed. When using a drying container in a drying process, the thing of various shapes can be used as a drying container. The drying container may be provided with an exhaust port, a heating device, a stirring device, and the like.
About drying temperature, although it can set suitably in the range below the heat-resistant temperature of the compound which has an inorganic granular material and an alkoxy silyl group, and a piperidine group, Usually, it is 30-200 degreeC, Preferably it is 50-120 degreeC. is there.

  The coating amount of the compound having an alkoxysilyl group and a piperidine group is not particularly limited, but is 0.1 parts by weight to 30 parts by weight, and further 0.3 parts by weight with respect to 100 parts by weight of the solid content of the inorganic particles. It is preferably about 20 parts by weight, more preferably about 0.5 parts by weight to 15 parts by weight.

  When coating a compound having an alkoxysilyl group and a piperidine group on the surface of the inorganic powder, the solvent, pigment, preservative, antifungal agent, antialgae agent, antibacterial agent, and dispersion are added to such an extent that the effects of the present invention are not impaired. You may mix and use additives, such as an agent, a ultraviolet absorber, and antioxidant.

The coating composition of the present invention is an inorganic powder formed by coating 100 parts by weight of a binder (solid content) containing an organic synthetic resin having a piperidine group with a compound having an alkoxysilyl group and a piperidine group. About parts by weight to 1000 parts by weight (further, 30 parts by weight to 800 parts by weight) are mixed and used.
In addition, known color pigments, extender pigments, aggregates, fibers, plasticizers, antiseptics, antifungal agents, antifoaming agents, viscosity modifiers, leveling agents, dispersants, anti-settling agents, dripping, etc. A coating composition can be obtained by blending an inhibitor, a matting agent, an ultraviolet absorber, a light stabilizer, an antioxidant, an antibacterial agent, an adsorbent, a solvent and the like alone or in combination.

The coating composition thus obtained is, for example, mortar, concrete, gypsum board, siding board, extruded board, slate board, asbestos cement board, fiber-mixed cement board, calcium silicate board, ALC board, metal, wood Can be applied to substrates such as glass, ceramics, fired tiles, porcelain tiles, plastic plates, synthetic resins, or coatings (such as undercoats or existing coatings) formed on such substrates. it can.
In addition, the coating method is not particularly limited and can be applied by a known method, but depending on the form of the paint, for example, painting using various coating instruments such as brushes, sprays, rollers, scissors, spatulas, It can be coated by various methods such as a roll coater and a flow coater. Moreover, what is necessary is just to set the coating amount of a coating material suitably according to various uses.

  Examples and Comparative Examples are shown below to clarify the features of the present invention, but the present invention is not limited to these Examples.

<Production of a compound having a piperidine group and an alkoxysilane group>
(Production Example 1)
40 parts by weight of 4-hydroxy-2,2,6,6-tetramethylpiperidine, 60 parts by weight of 3-isocyanatopropyltriethoxysilane, and 0.5 parts by weight of dibutyltin dilaurate are mixed and reacted at 50 ° C. for 3 hours. A compound having a piperidine group and an alkoxysilane group (hereinafter referred to as “compound (1)”) was obtained.
(Production Example 2)
4-hydroxy-1,2,2,6,6-pentamethylpiperidine (40.9 parts by weight), 3-isocyanatopropyltriethoxysilane (59.0 parts by weight) and dibutyltin dilaurate (0.1 parts by weight) were mixed and mixed at 50 ° C. To obtain a compound having a piperidine group and an alkoxysilane group (also referred to as “compound (2)”).

Example 1
Anatase-type titanium oxide (average particle size 150 nm, manufactured by Sakai Chemical Industry Co., Ltd.) (hereinafter referred to as “inorganic powder (1)”) 100 parts by weight, compound (1) 1.0 part by weight at a temperature of 25 ° C. The mixture was stirred and mixed for 1 hour at a relative humidity of 50% and dried at 100 ° C. for 1 hour to obtain particles (1).
As shown in Table 1, the obtained particles (1) were synthesized with an organic synthetic resin emulsion (1) (monomer components: acrylic acid, methyl methacrylate, 2-ethylhexyl acrylate, butyl methacrylate, styrene, compound (2), Glass transition temperature: 15 ° C., solid content: 50% by weight) 60 parts by weight, particles (1) 20 parts by weight, additives (film-forming aid, antifoaming agent, viscosity modifier) 20 parts by weight in a conventional manner The water-based paint (1) was produced by uniformly mixing and stirring.
The obtained water-based paint (1) was subjected to the following discoloration resistance test.

(Discoloration resistance test)
A SK clear sealer (synthetic resin emulsion sealer, manufactured by SK Kaken Co., Ltd.) was applied to a slate plate (150 mm × 150 mm) with a roller at 150 g / m ^{2 and} cured for 24 hours in a standard state. The coating material (1) was applied by spraying 300 g / m ^{2 and} dried in a standard state for 14 days to obtain a test specimen.
The resulting specimen was exposed outdoors in Ibaraki City, Osaka, at 45 degrees south for 1 month, and then exposed to the outdoors for 1 month using a color difference meter (CM-3700d, manufactured by Konica Minolta Holdings, Inc.). The color difference (Δb) was evaluated as follows. The results are shown in Table 1.
A: Δb = less than 0.5 ○: Δb = 0.5 or more and less than 1.0 Δ: Δb = 1.0 or more and less than 1.5 ×: Δb = 1.5 or more and less than 2.0

(Example 2)
100 parts by weight of the inorganic powder (1) and 5.0 parts by weight of the compound (1) are stirred and mixed for 1 hour at a temperature of 25 ° C. and a relative humidity of 50%, and dried at 100 ° C. for 1 hour. Got.
As shown in Table 1, the obtained particles (2) are 60 parts by weight of the organic synthetic resin emulsion (1), 20 parts by weight of the particles (2), and additives (film-forming aid, antifoaming agent, viscosity modifier). ) 20 parts by weight were uniformly mixed and stirred by a conventional method to produce an aqueous paint (2).
The obtained water-based paint (2) was subjected to the same discoloration resistance test as in Example 1. The results are shown in Table 1.

(Example 3)
100 parts by weight of the inorganic powder (1) and 10.0 parts by weight of the compound (1) were stirred and mixed at a temperature of 25 ° C. and a relative humidity of 50% for 1 hour, dried at 100 ° C. for 1 hour, and particles (3) Got.
As shown in Table 1, the obtained particles (3) were, as shown in Table 1, 60 parts by weight of the organic synthetic resin emulsion (1), 20 parts by weight of the particles (3), additives (film-forming aids, antifoaming agents, viscosity modifiers). ) 20 parts by weight were uniformly mixed and stirred by a conventional method to produce an aqueous paint (3).
The obtained water-based paint (3) was subjected to the same discoloration resistance test as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
As shown in Table 1, 60 parts by weight of the organic synthetic resin emulsion (1), 20 parts by weight of the inorganic powder (1), and 20 parts by weight of additives (film-forming auxiliary, antifoaming agent, viscosity modifier) are usually used. The mixture was uniformly mixed and stirred by the method to produce an aqueous paint (4).
The obtained water-based paint (4) was subjected to the same discoloration resistance test as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
Organic synthetic resin emulsion (2) (monomer component: acrylic acid, methyl methacrylate, 2-ethylhexyl acrylate, butyl methacrylate, styrene, glass transition temperature: 15 ° C., solid content: 50% by weight), 60 parts by weight, particles (1 ) 20 parts by weight and 20 parts by weight of additives (film-forming aid, antifoaming agent, viscosity modifier) were uniformly mixed and stirred by a conventional method to produce an aqueous paint (5).
The obtained water-based paint (5) was subjected to the same discoloration resistance test as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
60 parts by weight of the organic synthetic resin emulsion (2), 20 parts by weight of the inorganic powder (1), and 20 parts by weight of additives (film-forming auxiliary, antifoaming agent, viscosity modifier) are uniformly mixed in a conventional manner. The mixture was stirred to produce an aqueous paint (6).
The obtained water-based paint (6) was subjected to the same discoloration resistance test as in Example 1. The results are shown in Table 1.

Claims (1)

A binder comprising an organic synthetic resin having a piperidine group;
A coating composition comprising an inorganic granular material coated with a compound having an alkoxysilyl group and a piperidine group.