JP2014162900A - Coating composition and coating film forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition which reduces energy consumption during transport, can reduce loads of a coating operator, does not damage a base concealing property, has a small difference between the base concealing properties of a non-dried coating film immediately after coating and a dried film, and further has excellent wet abrasion resistance, and to provide a coating film forming method.SOLUTION: Provided is a coating composition comprising hydrous aluminum silicate, titanium dioxide, and a binder resin, wherein a mass ratio of hydrous aluminum silicate and titanium dioxide is 7 to 66%, a total pigment mass concentration of hydrous aluminum silicate and titanium dioxide is 25 to 40 mass%, and a median diameter calculated from a particle diameter distribution of hydrous aluminum silicate is 0.5 to 7 μm, the particle diameter distribution being measured by a laser diffraction scattering method with a sample liquid prepared by ultrasonic dispersion of hydrous aluminum silicate in a 0.2 mass% aqueous phosphate solution so that a concentration thereof becomes 1 mass%. Also provided is a coating film forming method wherein the coating composition is coated on a substrate to form a coating film.

Description

  The present invention relates to a coating composition and a coating film forming method. More specifically, the present invention relates to a coating composition containing hydrous aluminum silicate as a pigment in addition to titanium dioxide.

Titanium dioxide, which is generally used as an extender in building paints, has a large specific gravity, and the specific gravity of a rutile type that is suitably used as a paint raw material is 4.2.
Therefore, the paint containing titanium dioxide has a large paint mass in the same volume, and the energy cost during transportation is high. Moreover, since the mass of the paint is large, the paint can at the time of actual painting work is also heavy, which has been a heavy burden on the operator.
However, simply reducing the content of titanium dioxide in the paint reduces the base concealing property of the paint itself, so a substance that can be substituted and replaced is necessary.

On the other hand, general extender pigments are usually used to obtain a viscosity-imparting effect and a weight-increasing effect on the paint. However, the effect of hiding the groundwork was extremely small. For this reason, in order to obtain an alternative replacement effect of titanium dioxide, it is necessary to have a content that is twice or more the amount of titanium dioxide to be replaced. Therefore, it is known that the viscosity of the paint increases and the coating workability decreases. It was. Moreover, since the content of the binder resin is relatively reduced, it has been known that the general performance of the obtained coating film is deteriorated.
To date, the following techniques have been proposed to provide a base concealing effect by combining titanium dioxide and other components.

Patent Document 1 discloses titanium dioxide / calcium carbonate composite particles having excellent substrate hiding power and having calcium carbonate particles fixed on the surface of titanium dioxide particles.
Patent Document 2 discloses an architectural coating composition containing slaked lime and an inorganic pigment such as titanium oxide, which has a texture unique to stucco and can conceal a construction surface with a small amount of coating.
However, in any of the prior arts, the problem of reducing the burden on the painter by replacing titanium dioxide with another component while maintaining the base concealing property of titanium dioxide has not been solved. In addition, since there is a difference between the base concealing property of the undried coating immediately after application of the coating composition and the base concealing property of the dry coating, it is difficult to predict the finish of the dry coating at the time of coating. was there. Furthermore, there has been a problem that wet abrasion resistance is lowered by reducing the amount of titanium dioxide.
As a method for improving the wet abrasion resistance, it is generally known to those skilled in the art to use a pigment having a high Mohs hardness. For example, instead of titanium dioxide having a Mohs hardness of 6.0, feldspar powder having a Mohs hardness of 6.0, tertiary calcium phosphate having a Mohs hardness of 5.0, silica powder having a Mohs hardness of 7.0, or the like is added. Thus, the wet abrasion resistance can be improved. However, such a method could not solve the problem of lowering the base hiding property or causing a difference between the base hiding property of the undried coating film immediately after coating and the base hiding property of the dry coating film.

JP 2003-176131 A JP 2000-313843 A

  An object of the present invention is to provide a coating composition and a coating film forming method capable of reducing energy consumption during transportation by reducing the mass of the coating material and reducing the burden on a paint worker. is there. In addition to reducing the burden on the painter, the object of the present invention is not to impair the concealment of the base, and the base concealability of the undried coating immediately after coating and the base concealment of the dry coating It is an object of the present invention to provide a coating composition and a method for forming a coating film, which have a small difference from the above and have excellent wet abrasion resistance.

  As a result of intensive studies under such problems, the present inventors have found that such problems can be solved by using hydrous aluminum silicate as a partial substitute for titanium dioxide, and have completed the present invention. . The hydrous aluminum silicate used is not as reflective as titanium dioxide, and at first glance it is considered unsuitable as an alternative raw material, but when blended with titanium dioxide in a specific proportion, it is more than when titanium dioxide is used alone. On the contrary, the present inventors have found that excellent base concealing properties can be exhibited and have solved the present invention.

That is, the present invention
1. It contains hydrous aluminum silicate, titanium dioxide and a binder resin, the mass ratio of the hydrous aluminum silicate to the titanium dioxide (hydrous aluminum silicate / titanium dioxide) is 7 to 66%, and the hydrous aluminum silicate The total pigment mass concentration of the titanium dioxide and the titanium dioxide is 25 to 40% by mass, and the hydrous aluminum silicate has a mass concentration of the hydrous aluminum silicate with respect to a 0.2% by mass sodium hexametaphosphate aqueous solution. A coating composition having a median diameter of 0.5 to 7 μm calculated from a particle size distribution measured by a laser diffraction scattering method using a sample liquid prepared by ultrasonic dispersion so as to be 1% by mass;
2. Furthermore, 0.5 to 8% by mass of coated titanium dioxide whose surface is coated with calcium carbonate is included. A coating composition according to claim 1;
3. 1. The concealment ratio of the dried coating film measured according to JIS K5600-4-1 is 95% or more. Or 2. A coating composition according to claim 1;
4). 1. On the surface of the substrate ~ 3. 4. A coating film forming method of applying the coating composition according to any one of the above and forming a coating film; A metal substrate selected from the group consisting of iron, stainless steel, aluminum and its surface treated, a cement-based substrate selected from the group consisting of cements, limes, gypsums, and 3. One of plastic base materials selected from the group consisting of polyvinyl chlorides, polyesters, polycarbonates and acrylics. The coating film forming method as described in 1. is provided.

  According to the present invention, by substituting a specific proportion of titanium dioxide to be blended into the paint with hydrous aluminum silicate, the base concealability and drying of the undried coating film immediately after coating are not impaired without impairing the base concealability. The difference between the coating film and the underlying hiding property of the coating film is small, and the content of titanium dioxide in the coating can be reduced without impairing the wet abrasion resistance. Therefore, the mass of the paint is reduced, the consumption of fuel necessary for transportation can be reduced, and energy saving can be realized. Moreover, since the mass of the paint can be reduced, the burden on the operator during the painting work can be reduced. Furthermore, compared with the case where the same amount of titanium dioxide is contained, excellent base concealing property of an undried coating film and base concealing property of a dry coating film can be obtained.

In a first aspect, the present invention provides a coating composition comprising hydrous aluminum silicate, titanium dioxide and a binder resin.
The hydrous aluminum silicate contained in the coating composition of the present invention is an ore represented by the chemical formula Al ₂ Si ₂ O ₅ (OH) ₄ derived from a naturally occurring silicate mineral, and is generally used as a coating component. Any hydrated aluminum silicate or kaolin may be used. The median diameter of the hydrated aluminum silicate is generally 0.5 to 7 μm, preferably 0.5 to 5 μm, more preferably 0.5 to 4.5 μm. When the median diameter of the hydrated aluminum silicate used is less than 0.5 μm or more than 7 μm, the base hiding property of the undried coating film and the base hiding property of the dried coating film are unfavorable.
As a method for measuring the median diameter, a sample solution prepared by ultrasonically dispersing hydrous aluminum silicate with a mass concentration of 1% by mass with respect to a 0.2% by mass sodium hexametaphosphate aqueous solution was measured by laser diffraction. The method of calculating with a normal method from the particle diameter distribution measured with the measuring device using the scattering method can be mentioned. The ultrasonic dispersion can be performed, for example, using an ultrasonic cleaner 8510J-MTH manufactured by Yamato Scientific Co., Ltd. for 10 minutes under the conditions of an output of 320 W and a frequency of 44 kHz. Moreover, the measuring device by a laser diffraction scattering method can mention the laser diffraction scattering method particle size distribution measuring device LS13-320 by Beckman Coulter, for example.
Examples of commercially available hydrous aluminum silicate include MXK-101A (trade name, manufactured by Monsai Group), NeoGen 2000 (trade name, manufactured by IMERYS), Satinton W (trade name, manufactured by BASF), and the like. Can be mentioned. These hydrous aluminum silicates can be used alone or in combination.

  Titanium dioxide contained in the coating composition of the present invention is not particularly limited as long as it is generally used as a coating component, and specific examples include anatase-type titanium dioxide and rutile-type titanium dioxide. . Examples of such commercially available titanium dioxide include Taipei CR-95, Taipei CR-97, Taipei R-820 (trade name, manufactured by Ishihara Sangyo Co., Ltd.), and titanium R-650 (trade name, Sakai Chemical Industry). For example). These titanium dioxides can be used alone or in combination.

  The mass ratio of hydrous aluminum silicate and titanium dioxide contained in the coating composition of the present invention ((hydrous aluminum silicate / titanium dioxide) × 100) is 7 to 66%, preferably 15 to 35%. More preferably, it is 25 to 30%, and still more preferably 27 to 29%. If the mass ratio of the hydrated aluminum silicate to titanium dioxide used is less than 7%, the load during transportation of the paint cannot be reduced. On the other hand, if it exceeds 66%, the underlying concealability is lowered, which is not preferable.

  Further, the total pigment mass concentration (PWC) based on the solid content of the hydrous aluminum silicate and titanium dioxide contained in the coating composition of the present invention is generally 25 to 40% by mass, preferably 27 to 38% by mass. %, More preferably 29 to 33% by mass. When the total pigment mass concentration is less than 25% by mass, the base hiding property of the undried coating film and the base hiding property of the dry coating film are deteriorated. On the other hand, when the total pigment concentration exceeds 40% by mass, the coating performance is deteriorated.

  The binder resin contained in the coating composition of the present invention is not particularly limited as long as it is usually used as a binder resin for coatings, and for example, an acrylic resin, a polyester resin, an alkyd resin, an epoxy resin, or the like can be used. .

In the coating composition of the present invention, an acrylic resin is suitably used as the binder resin. As an acrylic resin, what is obtained by superposing | polymerizing the monomer which has a polymerizable unsaturated double bond well-known by those skilled in the art by a conventional method is preferable.
Examples of the monomer having a polymerizable unsaturated double bond include acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, ethacrylic acid, propylacrylic acid, isopropylacrylic acid, itaconic acid, maleic anhydride, and fumaric acid. Carboxylic acid group-containing monomers, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, hydroxyl-containing monomers such as ε-caprolactone-modified acrylic monomer, (meth) acrylic acid Methyl, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, (meth ) 2-ethylhexyl acrylate, ( ) (Meth) acrylate monomers such as octyl acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, styrene, α-methyl styrene, Examples thereof include styrene monomers such as α-methylstyrene dimer, vinyltoluene and divinylbenzene. For the polymerization, it is preferable to use a radical polymerization initiator or the like well known by those skilled in the art.

  In addition, when making the coating composition of this invention water-based, it is preferable to make the said acrylic resin water-based. As a method of making the acrylic resin into an aqueous type, for example, an acrylic resin having a carboxylic acid group is polymerized by solution polymerization, then neutralized with a neutralizing agent such as an amine compound, and dissolved or dispersed in water to dissolve in water. In addition to the method of obtaining a water-soluble acrylic resin or water-dispersed acrylic resin, from the viewpoint of minimizing the amount of organic solvent contained, a method of directly obtaining an emulsion resin by carrying out emulsion polymerization using an emulsifier, etc. The methods well known by the traders can be mentioned.

  Further, in the coating composition of the present invention, a solvent is used to uniformly dissolve or disperse the above-described components, and is not particularly limited as long as it is usually used as a solvent for coatings. For example, toluene, Aromatic hydrocarbons such as xylene, Solvesso 100 and Solvesso 150; esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and isophorone, and water. These can be appropriately selected according to the use in consideration of solubility, evaporation rate, safety, etc., and can be used alone or in combination of a plurality of raw materials. In the case where importance is attached to environmental measures and the like, for example, it is desirable to use water as an aqueous room temperature drying type or aqueous heat drying type coating composition.

Moreover, the coating composition of this invention can mix | blend the covering titanium dioxide which coat | covered the surface of titanium dioxide with calcium carbonate. By blending the above-mentioned coated titanium dioxide, the underlying concealment state between the undried coating immediately after coating the coating composition and the dried coating after drying can be visually equalized, and coating by the operator It is easy to adjust the amount of paint applied during work. The coated titanium dioxide is not particularly limited as long as it is a titanium dioxide / calcium carbonate body in which calcium carbonate is fixed on the surface of titanium dioxide. For example, the surface of the composite is a group consisting of resin acids, fatty acids, salts and derivatives thereof. In which a surface treatment layer containing one or more compounds selected from is formed. Moreover, the mass ratio of titanium dioxide and calcium carbonate in the coated titanium dioxide is usually 1:99 to 50:50, and the specific surface area of the coated titanium dioxide is usually 5 to 30 m ² / g. Specific examples of the resin acid that forms the surface treatment layer include, for example, abietic acid, neoabietic acid, parastrinic acid, levopimaric acid, dehydroabietic acid, pimaric acid, isopimaric acid, sandaracopimaric acid, comnic acid, and anticopal acid. Acid, lambertian acid, dihydroagatoic acid and salts and derivatives thereof, and specific examples of fatty acids include, for example, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachin Examples thereof include acids, behenic acid, lignoceric acid, serotic acid, montanic acid, melicic acid, and salts and derivatives thereof. Examples of such commercially available titanium dioxide products include a trade name Valkofil-R2 (trade name, manufactured by Shiroishi Chemical Co., Ltd.).

  The coating solid content pigment mass concentration (PWC) of the coated titanium dioxide contained in the coating composition of the present invention is generally 0.5 to 8% by mass, preferably 1 to 6% by mass. When the pigment mass concentration is less than 0.5% by mass, the load during transportation of the paint cannot be reduced. On the other hand, when the pigment mass concentration exceeds 8% by mass, the base concealability may be lowered.

Moreover, a hardening | curing agent can be mix | blended with the coating composition of this invention as needed.
The curing agent that can be used in the coating composition of the present invention is determined by the type of functional group of the binder resin described above. For example, when the binder resin has a hydroxyl group, an amino resin, a (blocked) polyisocyanate compound, or the like Further, when the binder resin has a carboxyl group, a resin having an epoxy group or a compound having a carbodiimide group can be used, and when the binder resin has a carbonyl group, a hydrazide compound or the like can be used.

  Moreover, a luster material can be mix | blended with the coating composition of this invention as needed. Examples of the bright material include mica, aluminum foil, tin foil, gold foil, silver foil, titanium gold foil, stainless steel foil, metal foil such as nickel / copper, and the like.

  In addition, other extender pigments, additives, and the like can be blended with the coating composition of the present invention as necessary. Further, feldspar powder, tricalcium phosphate, and silica powder to such an extent that the base concealability is not impaired, and to the extent that there is no difference between the base concealability of the undried coating immediately after coating and the base concealability of the dry coating. Etc. may be added.

  The coating composition of the present invention may be either an organic solvent type or an aqueous type, but is preferably an aqueous type from the viewpoint of environmental considerations.

  The coating composition of the present invention contains, for example, hydrated aluminum silicate, titanium dioxide and a binder resin in water or a solvent, and, if necessary, coated titanium, glittering material, particulate filler, additive, etc. in a disperser. It can be obtained by stirring and mixing.

The coating composition of the present invention thus obtained is suitably used as a paint for interiors of buildings, particularly buildings.
Such a coating composition of the present invention has a concealment ratio of 95% or more of the dry film thickness measured according to the concealment ratio test method B (concealment ratio test paper) of the coating film described in JIS-K5600-4-1. Preferably there is. If it is less than 95%, the base may not be completely covered. More preferably, it is 96% or more.

Moreover, this invention is a coating-film formation method which forms the coating film by apply | coating the above-mentioned coating composition on the base-material surface in the 2nd aspect, and making it dry.
The substrate to which the coating film forming method of the present invention is applied is not particularly limited, and examples thereof include metal substrates such as iron, stainless steel, aluminum, and the surface treated products thereof; cements, limes, plasters, and the like. Cement base materials: Plastic base materials such as polyvinyl chlorides, polyesters, polycarbonates, acrylics and the like. Moreover, the various to-be-coated articles of the building and building materials field | areas, such as building materials, a building, a structure, etc. which consist of these various base materials can be mentioned.

  The method for applying the coating composition is not particularly limited, and examples thereof include brush coating, roller coating, and spray coating. After coating, the coating film can be usually obtained by drying at room temperature or drying by heating. The coating amount; the order of coating such as undercoating, intermediate coating, and topcoating; the coating film thickness; the drying time, and the like can be arbitrarily set according to the type of coating composition and the substrate to be applied.

  EXAMPLES Hereinafter, although an Example is hung up and demonstrated in more detail about this invention, this invention is not limited only to these Examples. In the examples, “part” means “part by mass” unless otherwise specified.

Reference Example Water-based white paint composition 1
30.0 parts by mass of tap water, NP-136 (polycarboxylic acid dispersant, manufactured by San Nopco, solid content 40 parts by mass), 2.0 parts by mass, Type R-820N (trade name, rutile titanium dioxide, Ishihara Sangyo) 20.0 parts by mass, heavy coal N (trade name, heavy calcium carbonate, manufactured by Maruo Calcium Co., Ltd.), 4.0 parts by mass of phosphate-treated calcium carbonate, SN deformer 154 (trade name, mineral oil-based antifoam, manufactured by San Nopco) 0.2 parts by mass, Cybinol NP-550 (trade name, acrylic / styrene resin emulsion, manufactured by Seiden, solid content 50 parts by mass) 20. 0 parts by mass and Dalpad * C (trade name, tripropylene glycol film-forming aid, manufactured by Dow Chemical Co., Ltd.) To obtain a color coating composition 1.

Example 1 Aqueous white paint composition 2
The volume corresponding to 10% by mass (2.0 parts by mass) of the amount of TYPEKE® R-820N is equivalent to the volume of Calcined Kaolin MXK-101A (trade name, hydrous aluminum silicate, manufactured by Monxi Group, median diameter 0.53 μm) A water-based white coating composition 2 was obtained in the same manner as in the Reference Example except that 1.3 parts by mass was substituted.

Example 2 Aqueous white paint composition 3
Except that the volume corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N was replaced with 2.6 parts by mass of Calcined Kaolin MXK-101A corresponding to the volume, the same as in the reference example. An aqueous white coating composition 3 was obtained.

Example 3 Aqueous white paint composition 4
Except that the volume corresponding to 30% by mass (6.0 parts by mass) of the amount of TYPEKE R-820N was replaced with 3.9 parts by mass of Calcined Kaolin MXK-101A corresponding to the volume, the same as the reference example. An aqueous white coating composition 4 was obtained.

Example 4 Aqueous white paint composition 5
Except that the volume corresponding to 50% by mass (10.0 parts by mass) of the amount of TYPEQUE R-820N was replaced with 6.6 parts by mass of Calcined Kaolin MXK-101A corresponding to the volume, the same as in the reference example. An aqueous white coating composition 5 was obtained.

Example 5 Aqueous white paint composition 6
1. The volume corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N is NeoGen 2000 corresponding to the volume (trade name, hydrous aluminum silicate, IMERYS, median diameter 2.42 μm). A water-based white coating composition 6 was obtained in the same manner as in the reference example except that the substitution was performed with 6 parts by mass.

Example 6 Aqueous White Coating Composition 7
Aqueous white paint composition in the same manner as in the Reference Example, except that the volume corresponding to 30% by mass (6.0 parts by mass) of the amount of Typek R-820N was replaced with 3.9 parts by mass of NeoGen 2000 corresponding to the volume. Product 7 was obtained.

Example 7 Aqueous white paint composition 8
Aqueous white paint composition in the same manner as in the Reference Example, except that the volume corresponding to 50% by mass (10.0 parts by mass) of the amount of TYPEKE R-820N was replaced with 6.6 parts by mass of NeoGen 2000 corresponding to the volume. Product 8 was obtained.

Example 8 Aqueous white paint composition 9
Of the volume corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N, 50% by volume is replaced with 1.3 parts by mass of Calcined Kaolin MXK-101A corresponding to the volume, and the rest 50% by volume equivalent to 1.5 parts by mass of Valkofil-R2 (trade name, coated titanium dioxide whose surface is coated with calcium carbonate, manufactured by Shiroishi Chemical Industries, median diameter 0.82 μm) Except for this, an aqueous white coating composition 9 was obtained in the same manner as in the Reference Example.

Example 9 Aqueous white paint composition 10
Of the volume corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N, 75% by volume is replaced with 2.0 parts by mass of Calcined Kaolin MXK-101A corresponding to the volume, and the rest An aqueous white coating composition 10 was obtained in the same manner as in the Reference Example except that 25% by volume was replaced with 0.8 part by mass of Valkofil-R2 corresponding to the volume.

Example 10 Aqueous White Coating Composition 11
Of the volume equivalent to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N, 50% by volume is replaced with 1.3% by mass of NeoGen2000 corresponding to the volume, and the remaining 50% by volume is equivalent. Was replaced with 1.5 parts by mass of Valkofil-R2 corresponding to the volume to obtain an aqueous white coating composition 11 in the same manner as in the Reference Example.

Example 11 Aqueous white paint composition 12
Of the volume corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N, 75% by volume is replaced with 2.0 parts by mass of NeoGen 2000 corresponding to the volume, and the remaining 25% by volume is equivalent. Was replaced with 0.8 parts by mass of Valkofil-R2 corresponding to the volume, and an aqueous white coating composition 12 was obtained in the same manner as in the Reference Example.

Example 12 Aqueous white paint composition 13
Satinton W (trade name, hydrous aluminum silicate, manufactured by BASF Corp., median diameter 4.20 μm) 2 corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N blended 2 An aqueous white coating composition 13 was obtained in the same manner as in the Reference Example except that the amount was replaced with 6 parts by mass.

Comparative Example 1 Aqueous white coating composition 14
Aqueous white in the same manner as in the Reference Example, except that the volume corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N was replaced with 3.0 parts by mass of Valkofil-R2 corresponding to the volume. A coating composition 14 was obtained.

Comparative Example 2 Aqueous white paint composition 15
The volume corresponding to 10% by mass (2.0 parts by mass) of the amount of TYPEQUE R-820N is added to the volume corresponding to the volume (trade name, calcium carbonate, manufactured by Maruo Calcium Co., Ltd., median diameter 0.28 μm) 1.4. A water-based white coating composition 15 was obtained in the same manner as in the Reference Example except that the substitution was performed with parts by mass.

Comparative Example 3 Aqueous white paint composition 16
Aqueous white paint composition similar to the reference example except that the volume corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N was replaced with 2.7 parts by mass of Luminous corresponding to the volume. Product 16 was obtained.

Comparative Example 4 Aqueous white paint composition 17
Of the volume equivalent to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N, 25% by volume is replaced with 0.7 parts by mass of Calcined Kaolin MXK-101A corresponding to the volume, and the rest An aqueous white coating composition 17 was obtained in the same manner as in the Reference Example except that 75% by volume was replaced with 2.3 parts by mass of Valkofil-R2 corresponding to the volume.

Comparative Example 5 Aqueous white paint composition 18
Of the volume corresponding to 20% by mass (4.0 parts by mass) of the amount of TYPEKE R-820N, 25% by volume is replaced with 0.7% by mass of NeoGen2000 corresponding to the volume, and the remaining 75% by volume is equivalent. Was replaced with 2.3 parts by mass of Valkofil-R2 corresponding to the volume thereof to obtain an aqueous white coating composition 18 in the same manner as in the Reference Example.

Comparative Example 6 Aqueous white paint composition 19
The volume corresponding to 10% by mass (2.0 parts by mass) of the amount of TYPEKE R-820N is equal to the volume of Cerafill (trade name, hydrous aluminum silicate, manufactured by Pfematotech, median diameter 7.27 μm) 1 An aqueous white coating composition 19 was obtained in the same manner as in the Reference Example except that the amount was replaced with 3 parts by mass.

Evaluation Test (1) Paint Specific Gravity For the aqueous white paint compositions 1-19 obtained in Reference Examples, Examples 1-12 and Comparative Examples 1-6, the paint specific gravity was measured based on JIS K5600-2-4. The results are shown in Table 1.

(2) Underlaying concealment of undried coating immediately after coating JIS K5600-4-1 for each of the aqueous white coating compositions 1 to 19 obtained in Reference Examples, Examples 1 to 12 and Comparative Examples 1 to 6 The concealability test based on the method B (concealment rate) was performed, and the base concealability of the undried coating immediately after coating was compared with the reference example and evaluated visually. The results are shown in Table 1.
Evaluation criteria ◎ Brightness is higher than the reference example ○ Brightness is equivalent to the reference example △ Lightness is slightly lower than the reference example × Lightness is lower than the reference example

(3) Base concealing property of dry coating film The concealment rate was calculated | required according to JISK5600-4-1 as the base concealing property of the dry coating film after leaving the coating material evaluated in said (2) as it was for 24 hours. The results are shown in Table 1.

(4) Change in concealing property In each of Examples 1 to 12 and Reference Examples, in the evaluation of the concealing property of the undried coating immediately after coating and the concealing property of the dried coating, the undried coating immediately after coating. The change in concealability between the coating film and the dried coating film was visually evaluated. The results are shown in Table 1. In addition, about each of Comparative Examples 1-6, since the evaluation of the base concealment property of the undried coating film immediately after application | coating was inferior to the reference example, it did not evaluate.
Evaluation criteria ◎ There is no change in concealment between the undried coating immediately after application and the dry coating ○ There is a slight change in opacity between the undried coating immediately after application and the dry coating

(5) Wet Abrasion Resistance A wet abrasion resistance test based on JIS K5600-5-11 was performed on the aqueous white paint compositions 1-19 obtained in Reference Examples, Examples 1-12 and Comparative Examples 1-6. The state of the coating film surface was visually evaluated. The results are shown in Table 1.
Evaluation criteria ◎ Good ○ Slightly good

As shown in Table 1, compared with the reference example, in Examples 1 to 12, the coating composition was obtained by replacing a part of titanium dioxide in the coating composition with a hydrous aluminum silicate having the same volume as the part. It was shown that the specific gravity was reduced, resulting in a decrease in the mass of the paint.
In addition, hydrous aluminum silicate was considered unsuitable as an alternative raw material because of its low reflectance compared to titanium dioxide, but when blended with titanium dioxide at a specific ratio, it is equivalent to the case of using titanium dioxide alone or It was shown that the base concealing property of the undried coating immediately after coating and the base concealing property of the dry coating were exhibited. Furthermore, it was shown that at least the same performance was maintained in the change in hiding properties and wet wear resistance as compared with the case of using titanium dioxide alone.
In addition, only when a hydrous aluminum silicate having a specific median diameter range is used, an excellent base concealing property is shown. In hydrous aluminum silicate having a median diameter outside the range, titanium dioxide alone is used. It was shown that the base concealing property is worse than that in the case of using.
Furthermore, it was shown that when the titanium dioxide was replaced with a combination of hydrated aluminum silicate and coated titanium dioxide whose surface was coated with calcium carbonate, the change in the base hiding property was reduced.
On the other hand, as compared with the reference example, Comparative Examples 1 to 3 that do not use hydrous aluminum silicate, Comparative Examples 4 and 5 that do not use a predetermined amount of hydrous aluminum silicate, and the median diameter is outside the predetermined range. In Comparative Example 6, it was shown that the specific gravity of the coating material was reduced and, as a result, the mass of the coating material was reduced. However, the base hiding property of the undried coating film immediately after application and the base hiding property of the dry coating film were greatly reduced. It has been shown.

  The coating composition and the coating film forming method of the present invention can be suitably applied to the coating of building interiors.

Claims (5)

It contains hydrous aluminum silicate, titanium dioxide and a binder resin, the mass ratio of the hydrous aluminum silicate to the titanium dioxide (hydrous aluminum silicate / titanium dioxide) is 7 to 66%, and the hydrous aluminum silicate And the solid content total pigment mass concentration of the titanium dioxide and the titanium dioxide is 25 to 40% by mass,
In addition, the hydrated aluminum silicate is laser-diffracted with a sample solution prepared by ultrasonically dispersing the hydrated aluminum silicate so as to have a mass concentration of 1% by mass in a 0.2% by mass sodium hexametaphosphate aqueous solution. The coating composition whose median diameter computed from the particle size distribution measured by the scattering method is 0.5-7 micrometers.   Furthermore, the coating composition of Claim 1 which contains the coating titanium dioxide which coat | covered the surface of the titanium dioxide with calcium carbonate by 0.5-8 mass% in pigment mass concentration with respect to coating-material solid content.   The coating composition according to claim 1 or 2, wherein the concealment ratio of the dried coating film measured in accordance with JIS K5600-4-1 is 95% or more.   The coating-film formation method which apply | coats the coating composition in any one of Claims 1-3 to the base-material surface, and forms a coating film.   The base material is a metal base selected from the group consisting of iron, stainless steel, aluminum and its surface treated, a cement-based base selected from the group consisting of cements, limes, gypsums, and The method for forming a coating film according to claim 4, wherein the method is any one of plastic base materials selected from the group consisting of polyvinyl chlorides, polyesters, polycarbonates, and acrylics.