JP4917679B1 - Method for forming multilayer coating film for ceramics building materials - Google Patents

Abstract

An object of the present invention is to provide a ceramic coating material capable of forming a coating film having a good coating appearance even when the clear coating composition is applied without applying a drying process after the base clear coating composition is applied. To provide a method for forming a multilayer coating film.
In a ceramic building materials production line, a process of forming an aqueous base coating film by applying an aqueous base coating composition to an object to be coated;
A step of applying a water-based clear coating composition on the obtained aqueous base coating film by wet-on-wet to form a clear coating film, and a step of simultaneously drying the obtained aqueous base coating film and the clear coating film;
A multilayer coating film forming method for ceramic building materials,
This aqueous base coating composition is a method for forming a multilayer coating film for ceramics building materials, wherein the complex viscosity increase rate after 10 minutes from the start of viscosity measurement is 300 to 3,000%.
[Selection figure] None

Description

  The present invention relates to a method for forming a multilayer coating film for ceramic building materials.

  Building materials used for the outer wall of a building such as a house are required to have various colors and design properties according to the tastes of home buyers and users. With the development of unit construction methods in recent years, so-called prefabrication methods are progressing, in which painting is performed in advance during production on a building material production line, and the painted building materials are transferred to a construction site and assembled.

  When finishing by such a prefabricated construction method, ceramic building materials (ceramic siding) are widely used for the outer wall of a house. This ceramic building material has various advantages such as a shorter construction period and less earthquake damage compared to conventional mortar walls, etc., excellent fire resistance, and the provision of various housing exterior wall designs. This ceramic building material (ceramic siding) is generally manufactured by molding into a plate shape using cement, siliceous raw material, fibrous raw material, admixture, etc., and drying (curing / curing). JIS A It is a building material specified in 5422. Such a ceramic building material is provided with a sealer layer for the purpose of improving water resistance, water permeation resistance, etc. on the surface at the time of manufacture, and then imparts a desired design and coloring, etc. In many cases, an intermediate coating and / or a top coating for the purpose of improving weather resistance, moisture resistance, and the like are applied.

  In the intermediate coating and / or top coating of ceramic building materials, the base coating composition and the clear coating composition are often applied sequentially. In this case, after the base coating composition is applied, the obtained base coating is dried by heating, and then the clear coating composition is applied thereon, and the resulting clear coating is dried by heating to form a multilayer coating. It is common to form a film.

In recent years, the conventional coating film forming method has been demanded to improve energy saving and productivity. In particular, if the heat drying process can be reduced or shortened, it is preferable from the viewpoint of reducing the environmental load and reducing CO ₂ emissions. However, in the case of a conventional base coating composition, when a clear coating is provided without drying the base coating obtained by applying the base coating composition, the undried base coating and the clear coating are used. The problem of the mixed layer which the coating composition which comprises each layer mixes arises. This mixed layer may cause defects such as coating film appearance defects and coating film performance degradation.

  For example, in Japanese Patent No. 4034579 (Patent Document 1), (a) an aqueous coating composition mainly composed of an acrylic polymer aqueous dispersion having a glass transition temperature of -20 to 70 ° C. One coating layer, and (b) a silicone-containing acrylic polymer aqueous dispersion as a main component, and 5 to 60 parts by mass per 100 parts by mass (in terms of solids) of the solid content in the solid content of the dispersion It is described about the multilayer coating film which consists of the aqueous coating composition containing an organic silicone unit, and has the 2nd coating film layer formed on said 1st coating film layer (Claim 1). And this multilayer coating film is described as being a highly durable multilayer coating film applicable to inorganic building materials such as outer walls, inner walls or roofs of buildings such as houses and buildings, and ceramic building materials ( [0001] paragraph). In the formation of this multilayer coating film, the first aqueous coating composition for coating film layer is spray-coated, then dried at 100 ° C. for 5 minutes to form the first coating layer, and then the second coating film layer is formed. A multilayer coating film is formed by spray-coating the aqueous coating composition for coating layer and drying at 100 ° C. for 5 minutes ([0113] paragraph, etc.).

Japanese Patent No. 4034579

  An object of the present invention is to form a good coating film appearance even when a clear coating composition is applied without passing through a drying step after the base clear coating composition is applied in the formation of a multilayer coating film for ceramic building materials. It is providing the multilayer coating-film formation method which can form the coating film which has this.

The present invention
In the ceramic building materials production line, a process of forming an aqueous base coating film by applying an aqueous base coating composition to an object to be coated;
A step of applying a water-based clear coating composition on the obtained aqueous base coating film by wet-on-wet to form a clear coating film, and a step of simultaneously drying the obtained aqueous base coating film and the clear coating film;
A multilayer coating film forming method for ceramic building materials,
The aqueous base coating composition comprises an anionic aqueous resin dispersion (A), a water-soluble or water-dispersible polyfunctional amine polymer (B) and a volatile base compound (C).
This water-based base coating composition is measured from the start of measurement when the complex viscosity is measured using a viscoelasticity measuring jig which is a circular body having a cutout portion of 40 to 80% of the projected area in the rotation axis direction. The complex viscosity increase rate after 10 minutes is 300 to 3,000%.
The present invention provides a method for forming a multilayer coating film for ceramics building materials, whereby the above-mentioned problems are solved.

  It is preferable that the aqueous base coating composition further contains a viscosity modifier (D).

［式（１）中、Ｒ^１はＨまたはＣＨ_３であり、Ｒ^２およびＲ^３は、それぞれ独立して、Ｈまたは炭素数１〜２のアルキル基であり、Ｒ^４は炭素数１〜６０のアルキル基、炭素数７〜２０のアルキルフェニル基、炭素数１３〜２０のフェニルアルキルフェニル基、炭素数９〜１４の縮合環式構造を有する芳香族化合物の残基、または、ジ−もしくはトリ−スチレン化フェニル基であり、ｎは３〜１００である。］
で示される単量体を１種または２種以上 １〜６０質量部と、
炭素数１〜２０のアルキル基を有する（メタ）アクリル酸アルキルエステル０〜６０質量部
と、
これらと共重合可能なその他のエチレン性不飽和単量体０〜３０質量部と、
を共重合して得られる、重量平均分子量１００，０００〜５００，０００であるアルカリ可溶型粘性調整剤（ｄ−１）であるか、または、
アクリル酸（塩）および／またはメタクリル酸（塩）２５〜９０質量部と、
炭素数１〜２０のアルキル基を有する（メタ）アクリル酸アルキルエステル０〜６０質量部
と、
これらと共重合可能なその他のエチレン性不飽和単量体０〜３０質量部と、
を共重合して得られる、重量平均分子量５００，０００〜２，０００，０００であるアルカリ可溶型粘性調整剤（ｄ−２）であり、
上記多官能アミン重合体（Ｂ）のアミン価に対する、上記揮発性塩基化合物（Ｃ）の当量比が１〜５であるのが好ましい。 The polyfunctional amine polymer (B) is a water-soluble or water-dispersible polyfunctional amine polymer having a weight average molecular weight of 500 to 300,000 and an amine value of 100 to 1,300 mgKOH / g.
The volatile base compound (C) is an alkylamine or ammonia;
The viscosity modifier (D) is
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
Following formula (1)

In Expression (1), ^{R 1} is H or CH _3, ^{R 2} and ^{R 3} are each independently H or an alkyl group having a carbon number of 1 to 2, ^{R 4} is 1 to 60 carbon atoms An alkyl group having 7 to 20 carbon atoms, a phenylalkylphenyl group having 13 to 20 carbon atoms, a residue of an aromatic compound having a condensed cyclic structure having 9 to 14 carbon atoms, or di- or tri -Styrenated phenyl group, n is 3-100. ]
1 to 2 or more types of monomers represented by 1 to 60 parts by mass,
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
Or an alkali-soluble viscosity modifier (d-1) having a weight average molecular weight of 100,000 to 500,000, obtained by copolymerization of
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
An alkali-soluble viscosity modifier (d-2) having a weight average molecular weight of 500,000 to 2,000,000, obtained by copolymerization of
The equivalent ratio of the volatile base compound (C) to the amine value of the polyfunctional amine polymer (B) is preferably 1 to 5.

  The anionic aqueous resin dispersion (A) is at least one selected from the group consisting of an acrylic resin emulsion, a silicone-containing acrylic resin emulsion, a urethane resin emulsion, a vinyl acetate resin emulsion, a fluororesin emulsion, and a vinyl chloride resin emulsion. The seed is preferably an anionic aqueous resin dispersion having an acid value of 5 to 30 mg KOH / g.

Moreover, content of the polyfunctional amine polymer (B) contained in the said aqueous base coating composition is 0.5-8 mass with respect to 100 mass parts of solid content mass of an anionic aqueous resin dispersion (A). Department,
The content of the viscosity modifier (D) contained in the aqueous base coating composition is 0.1 to 10 parts by mass with respect to 100 parts by mass of the solid content of the anionic aqueous resin dispersion (A). Is preferred.

［式（１）中、Ｒ^１はＨまたはＣＨ_３であり、Ｒ^２およびＲ^３は、それぞれ独立して、Ｈまたは炭素数１〜２のアルキル基であり、Ｒ^４は炭素数１〜６０のアルキル基、炭素数７〜２０のアルキルフェニル基、炭素数１３〜２０のフェニルアルキルフェニル基、炭素数９〜１４の縮合環式構造を有する芳香族化合物の残基、または、ジ−もしくはトリ−スチレン化フェニル基であり、ｎは３〜１００である。］
で示される単量体を１種または２種以上 １〜６０質量部と、
炭素数１〜２０のアルキル基を有する（メタ）アクリル酸アルキルエステル０〜６０質量部
と、
これらと共重合可能なその他のエチレン性不飽和単量体０〜３０質量部と、
を共重合して得られる、重量平均分子量１００，０００〜５００，０００であるアルカリ可溶型粘性調整剤（ｄ−１）であるか、または、
アクリル酸（塩）および／またはメタクリル酸（塩）２５〜９０質量部と、
炭素数１〜２０のアルキル基を有する（メタ）アクリル酸アルキルエステル０〜６０質量部
と、
これらと共重合可能なその他のエチレン性不飽和単量体０〜３０質量部と、
を共重合して得られる、重量平均分子量５００，０００〜２，０００，０００であるアルカリ可溶型粘性調整剤（ｄ−２）であり、
この多官能アミン重合体（Ｂ）の含有量は、このアニオン性水性樹脂分散体（Ａ）の固形分質量１００質量部に対して０．５〜８質量部であり、
この粘性調整剤（Ｄ）の含有量は、このアニオン性水性樹脂分散体（Ａ）の固形分質量１００質量部に対して０．１〜１０質量部であり、および
この多官能アミン重合体（Ｂ）のアミン価に対する、揮発性塩基化合物（Ｃ）の当量比が１〜５である、
ウェットオンウェット窯業建材塗装用水性ベース塗料組成物、も提供する。 The present invention further includes
An anion having an acid value of 5 to 30 mg KOH / g, which is at least one selected from the group consisting of acrylic resin emulsion, silicone-containing acrylic resin emulsion, urethane resin emulsion, vinyl acetate resin emulsion, fluororesin emulsion and vinyl chloride resin emulsion Water-based resin dispersion (A),
A water-soluble polyfunctional amine polymer (B) having a weight average molecular weight of 500 to 300,000 and an amine value of 100 to 1300 mgKOH / g,
A volatile base compound (C) which is an alkylamine or ammonia, and
Viscosity modifier (D),
A water-based base coating composition for wet-on-wet ceramics building material coating,
This viscosity modifier (D)
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
Following formula (1)

In Expression (1), ^{R 1} is H or CH _3, ^{R 2} and ^{R 3} are each independently H or an alkyl group having a carbon number of 1 to 2, ^{R 4} is 1 to 60 carbon atoms An alkyl group having 7 to 20 carbon atoms, a phenylalkylphenyl group having 13 to 20 carbon atoms, a residue of an aromatic compound having a condensed cyclic structure having 9 to 14 carbon atoms, or di- or tri -Styrenated phenyl group, n is 3-100. ]
1 to 2 or more types of monomers represented by 1 to 60 parts by mass,
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
Or an alkali-soluble viscosity modifier (d-1) having a weight average molecular weight of 100,000 to 500,000, obtained by copolymerization of
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
An alkali-soluble viscosity modifier (d-2) having a weight average molecular weight of 500,000 to 2,000,000, obtained by copolymerization of
The content of the polyfunctional amine polymer (B) is 0.5 to 8 parts by mass with respect to 100 parts by mass of the solid content of the anionic aqueous resin dispersion (A).
The content of the viscosity modifier (D) is 0.1 to 10 parts by mass with respect to 100 parts by mass of the solid content of the anionic aqueous resin dispersion (A), and the polyfunctional amine polymer ( The equivalent ratio of the volatile base compound (C) to the amine value of B) is 1 to 5,
We also provide an aqueous base paint composition for wet-on-wet ceramics building materials.

The method for forming a multilayer coating film for ceramic building materials according to the present invention comprises applying an aqueous base coating composition to an object to be coated, then applying the aqueous clear coating composition wet-on-wet, and the resulting undried aqueous coating composition. The method includes a step of simultaneously drying the base coating and the clear coating. As described above, the multilayer coating film forming method for ceramic building materials according to the present invention is a wet-on-wet water-based clear coating composition without drying the aqueous base coating film obtained after coating the aqueous base coating composition. It can be painted. Thereby, it is possible to omit the drying step, which is necessary in the case of using the conventional coating composition, after applying the aqueous base coating composition and before applying the aqueous clear coating composition. As a result, it is possible to achieve reductions in equipment maintenance costs and energy costs, environmental burdens (energy saving, CO ₂ emission reduction), and further shortening of the painting process.

It is a figure which shows the aspect of the jig | tool for a viscoelasticity measurement used for the measurement of complex viscosity in this invention, (a) is a top view, (b) is sectional drawing in AA.

The method of forming a multilayer coating film for ceramic building materials according to the present invention is a step of forming an aqueous base coating film by coating an aqueous base coating composition on an object to be coated in a ceramic building material production line.
A step of applying a water-based clear coating composition on the obtained aqueous base coating film by wet-on-wet to form a clear coating film, and a step of simultaneously drying the obtained aqueous base coating film and the clear coating film;
Is included. And as this aqueous base coating composition, what contains the anionic aqueous resin dispersion (A) detailed below, water-soluble or water-dispersible polyfunctional amine polymer (B), and volatile base compound (C) Use. This aqueous base coating composition preferably further contains a viscosity modifier (D).

  This water-based base coating composition is measured from the start of measurement when the complex viscosity is measured using a viscoelasticity measuring jig which is a circular body having a cutout portion of 40 to 80% of the projected area in the rotation axis direction. The complex viscosity increase rate after 10 minutes is 300 to 3,000%. As a result, after applying the aqueous base coating composition, even if the aqueous clear coating composition is applied wet-on-wet without being dried, problems such as a mixed layer in the aqueous base coating film and the aqueous clear coating film occur. There is no advantage. When the increase rate of the complex viscosity is less than 300%, there is a possibility that a mixed layer in the aqueous base coating film and the aqueous clear coating film may be formed when coating is performed wet-on-wet. On the other hand, when the increase rate exceeds 3,000%, the storage stability of the aqueous base coating composition may be impaired. The complex viscosity increase rate is more preferably 500 to 2,500%.

In this specification, the “complex viscosity increase rate” means the complex viscosity (η ₀ ) at the start of measurement and the measurement when the complex viscosity measurement of the aqueous base coating composition is performed using a specific viscoelasticity measuring jig. The complex viscosity (η ₁ ) after 10 minutes from the start was measured, and the following formula:
Complex viscosity increase rate = η ₁ / η ₀ × 100
Means the rate required by.

  The complex viscosity measurement of an aqueous base coating composition has a rotating rheometer, and this rotating rheometer sets a sample on a table and puts it at a constant angular frequency on a parallel disk that is in contact with the sample. Measure the viscoelasticity of the sample by applying a sine wave torque and measuring the generated sine wave angular displacement, or applying a sine wave displacement of a constant angular frequency to the sample and measuring the generated sine wave torque. It can be measured using a commonly used dynamic viscoelastic device.

More specifically, the complex viscosity can be measured with the following equipment and measurement conditions.
Measuring instrument: Stress-controlled viscoelasticity measuring device Physica MCR 301 (manufactured by Anton Paar)
Temperature condition (plate temperature): 40 ° C (constant temperature)
Angular frequency: 6.3 rad / s
The coating composition is put into a measurement cell of the viscoelasticity measuring apparatus so as to have a thickness of 0.6 mm, and a specific viscoelasticity measuring jig is put to a depth of 0.1 mm from above the coating composition. The torque is measured by applying an angular frequency of 6.3 rad / s to the measurement cell, and the phase difference between the sinusoidal angular displacement and the torque-angular displacement is measured to thereby determine the complex viscosity of the coating composition. Can be sought.

  The viscoelasticity measuring jig used for the measurement of the complex viscosity in the present invention uses a viscoelasticity measuring jig that is a circular body having a cutout portion of 40 to 80% of the projected area in the rotation axis direction. By having such a notch part, the volatile component in the coating composition volatilizes without being disturbed by the jig. Thereby, it becomes possible to measure the viscoelasticity of a coating composition in the state according to the viscoelastic behavior in an actual coating process.

  A more specific shape of the viscoelasticity measuring jig will be described with reference to FIG. FIG. 1 is a diagram showing a specific mode of a viscoelasticity measuring jig, FIG. 1A is a plan view thereof, and FIG. 1B is a sectional view taken along a cutting line AA. As shown in FIG. 1, the viscoelasticity measuring jig 1 is composed of a rotating shaft 2 and a circular body 3 concentrically attached to the tip of the rotating shaft 2, and the circular body 3 is an annular body. 4 and a support body 5 that supports the annular body 4 on the rotating shaft 2, and four support bodies 5 are formed radially from the rotating shaft 2 toward the annular body 4. And the notch part 6 is formed in four places by the rotating shaft 2, the annular body 4, and the four support bodies 5. FIG.

Further, the joint portion between the annular body 4 and the support body 5 and the joint portion between the rotating shaft 2 and the support body 5 are formed in a minute curved surface in order to ensure strength. And the ratio of the area of the notch part 6 is set to 40 to 80% by selecting suitably the diameter of the rotating shaft 2, the diameter, the width | variety and thickness of the annular body 4, and the width | variety, thickness, and number of the support body 5. can do. The ratio of the area of this notch is more preferably 50 to 75%.

The diameter (outer diameter) of the annular body 4 is 10 to 80 mm, preferably 20 to 70 mm, more preferably 20 to 60 mm. For example, a conventionally used viscoelasticity measuring jig (disk) is used. If the outer shape is the same, a conventional viscoelasticity measuring apparatus can be used as it is. The width of the annular body 4 is 0.5 to 20 mm, preferably 1 to 10 mm, more preferably 1 to 5 mm, and the thickness of the annular body 4 is 0.5 to 5 mm, preferably 1 to 3 mm. More preferably, it is 1.2-2 mm. The width of the support 5 is 0.5 to 20 mm, preferably 1 to 10 mm, more preferably 1 to 5 mm, and the thickness of the support 5 is 0.5 to 5 mm, preferably 1 to 3 mm, more preferably. Is 1.2 to 2 mm, and the number of the supports 5 is 2 to 15, preferably 3 to 10, and more preferably 3 to 6.

The ratio of the area of the notch portion 6 can be obtained according to the following. For example, taking the viscoelasticity measuring jig 1 shown in FIG. 1a as an example, the diameter of the portion of the rotating shaft 2 joined to the support 5 is 11.0 mm, the diameter of the annular body 4 is 50.0 mm, and the width Is 5.0 mm and the width of the support 5 is 5.0 mm, the projected area of the circular body 3 in the rotation axis direction is about 1963 mm ² , and the projected areas of the rotation shaft 2, the annular body 4 and the support 5 are Is about 1091 mm ² , and the total area of the four notch portions 6 is 872 mm ² . Therefore, the ratio of the total area of the cutout portions 6 is about 44% of the projected area of the circular body 3 in the rotation axis direction, and the ratio of the non-contact area is about 56 of the projected area of the circular body 3 in the rotation axis direction. %.

  The material of the rotating shaft 2 and the circular body 3 (the annular body 4 and the support body 5) constituting the viscoelasticity measuring jig 1 is not particularly limited, and is used for the viscoelasticity measuring jig 1. The material can be selected as appropriate. The material may be, for example, a metal such as aluminum, titanium, iron, nickel, copper, and stainless steel, an alloy, ceramics, glass, or the like, and may be composed of the same material or a combination of several types of materials. For example, even if the rotating shaft 2, the annular body 4 and the support body 5 are formed of the same material, the annular body 4 and the support body 5 may be configured of the same material, and the rotating shaft 2 may be configured of different materials. it can.

  Furthermore, when it is desired to reduce the loss of heat from the viscoelasticity measuring jig 1 constituted by the circular body 3 and the rotating shaft 2, a metal having good thermal conductivity is used as the material of the circular body 3 and the rotating shaft 2. Avoid using ceramic or glass with poor thermal conductivity. On the other hand, aluminum and stainless steel are preferable from the viewpoint of ease of molding and the rigidity of the material.

  The aqueous base coating composition used in the method of the present invention has a complex viscosity using the above-mentioned viscoelasticity measuring jig which is a circular body having a cutout portion of 40 to 80% of the projected area in the rotation axis direction. When measured, the complex viscosity increase rate after 10 minutes from the start of measurement is 300 to 3,000%. In the present invention, by using the aqueous base coating composition having such a complex viscosity increase rate, the aqueous clear coating composition is applied without drying the obtained aqueous base coating film after the aqueous base coating composition is applied. Even when an object is applied wet-on-wet, a good multilayer coating film can be obtained. In the present specification, “coating the aqueous clear coating composition on the aqueous base coating film by wet-on-wet” means that the aqueous base coating composition obtained after the aqueous base coating composition is applied This means that the aqueous clear coating composition is applied in an undried state without passing through the drying means.

Aqueous base coating composition The aqueous base coating composition used in the method of the present invention comprises an anionic aqueous resin dispersion (A), a water-soluble or water-dispersible polyfunctional amine polymer (B), and a volatile base compound (C )including. This aqueous base coating composition preferably further contains a viscosity modifier (D). Hereinafter, each component will be described in detail.

Anionic aqueous resin dispersion (A)
The anionic aqueous resin dispersion (A) contained in the aqueous base coating composition is a film-forming resin component. As the anionic aqueous resin dispersion (A), for example, an acrylic resin emulsion, a silicone-containing acrylic resin emulsion, a urethane resin emulsion, a vinyl acetate resin emulsion, a fluororesin emulsion, a vinyl chloride resin emulsion, and the like can be used. These resins may be used alone or in combination of two or more. As the anionic aqueous resin dispersion (A), it is preferable to use an acrylic resin emulsion or a silicone-containing acrylic resin emulsion.

  The anionic aqueous resin dispersion (A) preferably has an acid value of 5 to 30 mgKOH / g, and more preferably 5 to 20 mgKOH / g. When the acid value of the anionic aqueous resin dispersion (A) is less than 5 mgKOH / g, the drying property after applying the aqueous base coating composition is lowered, and then the mixed layer with the clear coating film to be provided is May be more likely to occur. On the other hand, when the acid value of the anionic aqueous resin dispersion (A) exceeds 30 mgKOH / g, the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) are contained in the aqueous clear coating composition. There is a risk that paint storage stability may be inferior, for example, a partial reaction occurs to increase the viscosity. In addition, in this specification, an acid value represents a solid content acid value and can be measured by the well-known method described in JISK0070.

  Examples of the acrylic resin emulsion used as the anionic aqueous resin dispersion (A) include acrylic resin emulsions obtained by polymerization of various polymerizable monomers. The said polymerizable monomer means what has at least 1 unsaturated bond, such as a vinyl group, in a molecule | numerator, and the derivative | guide_body of acrylic acid or methacrylic acid is included. The polymerizable monomer is not particularly limited, and examples thereof include ethylenically unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid; methyl (meth) acrylate, (meth) acrylic Ethyl unsaturated carboxylic acid alkyl ester monomers such as ethyl acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; cyclopentyl such as cyclopentyl (meth) acrylate and cyclohexyl (meth) acrylate Alkyl group-containing polymerizable monomers; monoester monomers of ethylenically unsaturated dicarboxylic acid such as ethyl maleate, butyl maleate, ethyl itaconate, butyl itaconate; 2-hydroxyethyl (meth) acrylate, ( 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) Hydroxyl group-containing ethylenically unsaturated carboxylic acid alkyl ester monomer such as a reaction product of 2-hydroxyethyl acrylate and ε-caprolactone; aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, (meth) Ethylenically unsaturated carboxylic acid aminoalkyl ester monomers such as butylaminoethyl acrylate; ethylenically unsaturated carboxylic acids such as aminoethyl (meth) acrylamide, dimethylaminomethyl (meth) acrylamide, and methylaminopropyl (meth) acrylamide Aminoalkylamide monomers; other amide group-containing ethylenically unsaturated carboxylic acid monomers such as acrylamide, methacrylamide, N-methylolacrylamide, methoxybutylacrylamide, diacetoneacrylamide; Unsaturated fatty acid glycidyl ester monomers such as sidyl and glycidyl methacrylate; vinyl cyanide monomers such as (meth) acrylonitrile and α-chloroacrylonitrile; saturated aliphatic carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate Monomers; Styrene monomers such as styrene, α-methylstyrene, vinyltoluene and the like can be mentioned. These can be used alone or in combination of two or more. In the present specification, (meth) acrylic acid refers to acrylic acid or methacrylic acid. By using such an acrylic resin emulsion, it is possible to obtain good adhesion to building materials that are objects to be coated and good weather resistance, which is preferable.

  The acrylic resin emulsion may form an aqueous polymer dispersion in which multi-layer structured particles composed of a core part and a shell part are dispersed. The multilayer structure particle is an acrylic polymer in which the resin forming the core part has a glass transition temperature of −70 to 35 ° C., and the resin forming the shell part is an acrylic polymer having a glass transition temperature of 25 to 80 ° C. It is preferable. An aqueous polymer dispersion in which such multilayer structure particles are dispersed can be prepared by a known production method described in JP-A No. 2002-12816.

  The glass transition temperature of the acrylic polymer can be calculated based on the known glass transition temperature and composition ratio of the constituent monomer or homopolymer.

  The acrylic resin emulsion preferably has a particle size of 20 to 500 nm, and more preferably 50 to 200 nm. If the particle size is less than 20 nm, the viscosity of the paint increases, and more diluent is required to ensure coating workability, and there is a risk that the paint solids concentration will decrease significantly. In addition, the stability of the acrylic resin emulsion may be reduced. In the present specification, the particle diameter is an average particle diameter determined by a dynamic light scattering method. Specifically, an electrophoretic light scattering photometer ELS-800 (manufactured by Otsuka Electronics Co., Ltd.) or the like is used. Can be measured using.

  Examples of the silicone-containing acrylic resin emulsion include a polymer obtained by polymerization of a monomer composition further containing an alkoxysilyl group-containing polymerizable monomer in addition to the polymerizable monomer. .

  The alkoxysilyl group-containing polymerizable monomer is not particularly limited as long as it is a polymerizable monomer containing an alkoxysilyl group having 1 to 14 carbon atoms. For example, trimethoxysilylpropyl (meth) acrylate, ( (Meth) acrylic acid triethoxysilylpropyl, (meth) acrylic acid tributoxysilylpropyl, (meth) acrylic acid dimethoxymethylsilylpropyl, (meth) acrylic acid methoxydimethylsilylpropyl, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl Examples include dimethoxymethylsilane, vinylmethoxydimethylsilane, and vinyltris (β-methoxyethoxy) silane. These can be used alone or in combination of two or more. Among these, in particular, trimethoxysilylpropyl (meth) acrylate, triethoxysilylpropyl (meth) acrylate, vinyltrimethoxysilane, vinyltriethoxysilane and the like can be mentioned.

  Furthermore, an organic silicone unit may be introduced into the silicone-containing acrylic resin emulsion. As a method for introducing an organosilicone unit, a mixture of an organosilicone compound and an acrylic polymerizable monomer is emulsion-polymerized and subjected to hydrolysis, condensation reaction and radical polymerization, and a monomer having a silicone functional group is copolymerized. Examples thereof include a method, a method of bonding an organosilicone compound to the surface of acrylic polymer particles by reacting an organosilicone compound with an acrylic polymer. Two or more methods described above may be combined.

The organosilicon compound used in the above method is not particularly limited, and examples thereof include organosilane, hydrolyzate of organosilane, and condensate of organosilane.

The organosilane is generally represented by the following general formula (2)
(R ⁵ ) _n Si (OR ⁶ ) _4-n (2)

[In the formula, when two R ⁵ are present, they are the same or different and each represents a monovalent organic group having 1 to 8 carbon atoms. R ⁶ is the same or different and represents an alkyl group having 1 to 5 carbon atoms or an acyl group having 1 to 6 carbon atoms. Is an integer of 0-2. ]
It is represented by

The hydrolyzate of the organosilane is a compound in which the OR ⁶ group of the organosilane represented by the general formula (2) is hydrolyzed. It is not necessary that 2 to 4 OR ⁶ groups contained in the organosilane are all hydrolyzed, for example, only one is hydrolyzed, two or more are hydrolyzed, or these It may be a mixture of

  The organosilane condensate is obtained by condensing silanol groups of an organosilane hydrolyzate to form a Si-O-Si bond. The organosilicone compound may be a mixture of all of the silanol groups, a mixture of a small part of the silanol groups, or a mixture of those having different degrees of condensation.

In the general formula (2), examples of the monovalent organic group having 1 to 8 carbon atoms of R ⁵ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and an i-butyl. Group, sec-butyl group, t-butyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group and other alkyl groups; acetyl group, propionyl group, butyryl group, valeryl group, benzoyl group Acyl groups such as trioyl group and caproyl group; vinyl group, allyl group, cyclohexyl group, phenyl group, epoxy group, glycidyl group, (meth) acryloxy group, ureido group, amide group, fluoroacetamide group, isocyanate group, etc. In addition to these, substituted derivatives of these groups can be mentioned.

Examples of the substituent in the substituted derivative of R ⁵ include a halogen atom, a substituted or unsubstituted amino group, a hydroxyl group, a mercapto group, an isocyanate group, a glycidoxy group, a 3,4-epoxycyclohexyl group, and a (meth) acryloxy group. Ureido groups, ammonium bases and the like. However, the number of carbon atoms of R ⁵ consisting of substituted derivatives thereof is 8 or less including the carbon atoms in the substituent. In the general formula (2), when two R ⁵ are present, they may be the same as or different from each other.

The alkyl group having 1 to 5 carbon atoms for ^{R 6,} for example, a methyl group, an ethyl group, n- propyl group, i- propyl, n- butyl group, sec- butyl group, t- butyl radical, n -A pentyl group etc. can be mentioned, As a C1-C6 acyl group, an acetyl group, a propionyl group, a butyryl group, a valeryl group, a caproyl group etc. can be mentioned, for example. A plurality of R ⁶ present in the general formula (2) may be the same as or different from each other.

  The organosilane is not particularly limited, and examples thereof include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane; Methoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, n-butyltri Methoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyltrimethoxysilane, vinyltol Ethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxy Silane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxy Propyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropi Trimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) attaacryloxy Trialkoxysilanes such as propyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, di Ethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-i-propyldimethoxysilane, di-i-propyldiethoxysilane, di-n-butyldimethoxysilane, di-n -Butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldiethoxysilane, di-n-heptyldimethoxysilane, di- n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxysilane, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, etc. In addition to dialkoxysilanes, Triacetyl silane, and dimethyl di acetyloxy silane.

  Of these, trialkoxysilanes and dialkoxysilanes are preferably used. As the trialkoxysilanes, methyltrimethoxysilane and methyltriethoxysilane are preferable, and dialkoxysilanes are more preferable. Is preferably dimethyldimethoxysilane or dimethyldiethoxysilane.

  Examples of the anionic aqueous resin dispersion (A) include urethane resin emulsions, vinyl acetate resin emulsions, fluororesin emulsions, and vinyl chloride resin emulsions commonly used by those skilled in the art.

Multifunctional amine polymer (B)
The polyfunctional amine polymer (B) used in the present invention is a water-soluble or water-dispersible amine polymer. The polyfunctional amine polymer preferably has a weight average molecular weight of 500 to 300,000, more preferably 3,000 to 200,000. The amine value of the polyfunctional amine polymer is preferably from 100 to 1,300 mgKOH / g, more preferably from 300 to 1,000 mgKOH / g. Water-soluble means that the polymer is completely soluble in water, and water-dispersible means that part of the polymer is soluble in water and is in the form of molecular micelles or aggregates. It means a dissolved state.

  When the weight average molecular weight of the polyfunctional amine polymer (B) is less than 500, the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) in the undried aqueous base coating film Aggregation due to interaction becomes insufficient, and there is a possibility that a mixed layer is formed with an undried clear coating film. Moreover, when the weight average molecular weight of the polyfunctional amine polymer (B) exceeds 300,000, excessive aggregation occurs due to the interaction between the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B). , There is a possibility that the adhesion to the object to be coated is lowered or the coating film becomes brittle.

  In addition, in this specification, a weight average molecular weight can be measured by GPC (gel permeation chromatography), and can be calculated by the conversion value by a polystyrene standard.

  When the amine value of the polyfunctional amine polymer (B) is less than 100 mgKOH / g, aggregation due to the interaction of the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) becomes insufficient, There is a possibility of causing a mixed layer between the undried clear coating film. Further, when the amine value of the polyfunctional amine polymer (B) exceeds 1,300 mgKOH / g, the storage stability of the aqueous base coating composition is impaired, and there is a risk of thickening and gelation. The water resistance, durability, and weather resistance of the film may be inferior.

  The amine value of the polyfunctional amine polymer (B) can be measured by a known method described in JIS K 7237.

  The polyfunctional amine polymer (B) is not particularly limited as long as it is a resin having a cationic functional group. For example, polyalkyleneimines, polyvinylamines, polyamides having an amino group as a cationic functional group Examples thereof include basic nitrogen-containing resins such as amines, aminosulfopolyesters, polyallylamines, and modified polymers thereof. These may use only 1 type and may use 2 or more types together.

  Polyalkyleneimines generally include ethyleneimine, 1,2-propyleneimine, 1,2-dodecyleneimine, 1,1-dimethylethyleneimine, phenylethyleneimine, benzylethyleneimine, hydroxyethylethyleneimine, aminoethylethyleneimine, 2-methylpropyleneimine, 3-chloropropylethyleneimine, methoxyethylethyleneimine, dodecylaziridinylformate, N-ethylethyleneimine, N- (2-aminoethyl) ethyleneimine, N-phenethylethyleneimine, N- (2-hydroxyethyl) ethyleneimine, N- (cyanoethyl) ethyleneimine, N- (p-chlorophenyl) ethyleneimine and other alkylene imine methods, or alkyloxazoline polymerized And then, can be produced by a method such as to partially hydrolyzed or fully hydrolyzed the polymer is not particularly limited.

  One of the means for adjusting the polyvinylamines is a method of polymerizing one or more amine functional group-containing monomers. As another means for preparing polyvinylamines, one or more amine functional group-containing monomers are copolymerized with another monomer that is copolymerizable with the amine functional group-containing monomer. A method is mentioned. Examples of the amine functional group-containing monomer include amino acids such as β-aminoethyl vinyl ether, N-monomethyl-β-aminoethyl vinyl ether, N-monoethyl-β-aminoethyl vinyl ether, and N-monobutyl-β-aminoethyl vinyl ether. Alkyl vinyl ethers; aminoalkyl vinyl sulfides such as β-aminoethyl vinyl sulfide, N-monomethyl-β-aminoethyl vinyl sulfide, N-monoethyl-β-aminoethyl vinyl sulfide, N-monobutyl-β-aminoethyl vinyl sulfide; dimethyl Acrylic acid esters such as aminoethyl acrylate and β-aminoethyl acrylate; Methacrylic acid esters such as dimethylaminoethyl methacrylate and β-aminoethyl methacrylate; N-β-aminoethyl acetate Acrylamide such as chloramide, N- (monomethylaminoethyl) -acrylamide; Methacrylamide such as N-β-aminoethylmethacrylamide, N- (monomethylaminoethyl) -methacrylamide; Oxazolidinylethyl acrylate, Oxazolidinyl Oxazolidine compounds such as ethyl methacrylate; monoallylamine, diallylamine, methyldiallylamine, ethyldiallylamine, propyldiallylamine, butyldiallylamine, benzyldiallylamine, cyclohexyldiallylamine, etc .; allylamine; N-vinyldimethylamine, N-vinyldiethylamine, N-vinyldiphenylamine, etc. Vinylamine and the like.

  Examples of other monomers copolymerizable with the amine functional group-containing monomer include unsaturated carboxylic acid monomers having an acid group such as acrylic acid and methacrylic acid, and C 1-8 having a hydroxyl group. (Meth) acrylic acid ester monomers, C1-C20 (meth) acrylic acid ester monomers, amide group-containing monomers such as acrylamide and methacrylamide, styrene, vinyltoluene, vinyl acetate, vinyl chloride , Vinylidene chloride, butadiene, substituted butadiene, ethylene and the like. As a method for polymerizing these, known methods such as a solution polymerization method and an emulsion polymerization method can be used.

  The polyallylamine is generally obtained by polymerizing a hydrochloride of an allylamine monomer and then removing hydrochloric acid, but is not particularly limited. For example, polyallylamine, polyallylamine hydrochloride, polyallylethylamine hydrochloride, polyallyldimethylethylammonium hydrochloride, diallylamine hydrochloride polymer, diallylmethylamine hydrochloride polymer, diallyldimethylammonium hydrochloride polymer, these sulfur dioxides Examples include copolymers, acrylamide copolymers, diallylamine hydrochloride derivative copolymers, dimethylaminoethyl (meth) acrylate copolymers, and the like.

  The polyamidoamines are generally hexamethylenediamine, 1,4-phenylenediamine, 1,3-phenylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, dipropylenepentamine, dipropylenetriamine, tripropylenetetra. Polyalkylene polyamines such as amine and dihexamethylenetriamine, and dicarboxylic acids such as adipic acid, isophthalic acid, terephthalic acid, succinic acid, maleic acid, glutaric acid, corkic acid, sebacic acid, and derivatives thereof such as acid chlorides thereof The polycondensate obtained by polycondensation, interfacial polycondensation, low-temperature solution polycondensation, polyphosphoric acid solution polycondensation, solid phase polycondensation, etc .; polycondensation of diisocyanate and dicarboxylic acid; Adduct; ring-opening polymer of lactam; Including without being limited thereto.

  Examples of the aminosulfopolyester include polyalkanolamines such as diethanolamine, N-methyldiethanolamine, and triethanolamine; diols such as diethylene glycol, triethylene glycol, and 1,4-cyclohexanedimethanol; adipic acid, and isophthalic acid. Dicarboxylic acid such as acid, terephthalic acid, succinic acid, maleic acid, glutaric acid, corkic acid, sebacic acid and 5-sodiosulfoisophthalic acid are heated, and the water produced is removed under reduced pressure, followed by dehydration condensation. However, it is not limited to these.

  By using such a polyfunctional amine polymer (B), when a water-based base coating composition and a water-based clear coating composition are wet-on-wet coated, a coating film having a better appearance can be formed. There is an advantage.

  The content of the polyfunctional amine polymer (B) contained in the aqueous base coating composition in the present invention is 0.5 to 8 mass with respect to 100 mass parts of the solid content mass of the anionic aqueous resin dispersion (A). Part. When the content of the polyfunctional amine polymer (B) is less than 0.5 parts by mass, the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) after the application of the aqueous base coating composition is performed. ) Due to the interaction may be insufficient, and a mixed layer with the clear layer may be generated. On the other hand, when the content of the polyfunctional amine polymer (B) exceeds 8 parts by mass, the storage stability of the aqueous base coating composition is inferior, and there is a possibility that thickening or gelation may occur. Moreover, there exists a possibility that the water resistance of a coating film obtained, durability, and a weather resistance may be inferior. The content of the polyfunctional amine polymer (B) is more preferably 1 to 6.5 parts by mass with respect to 100 parts by mass of the solid content of the anionic aqueous resin dispersion (A).

Volatile base compounds (C)
The aqueous base coating composition in the present invention contains a volatile base compound (C). In the aqueous base coating composition of the present invention, when a base other than the volatile base compound (C), for example, a non-volatile base such as sodium hydroxide or potassium hydroxide is used, the aqueous base coating composition is applied. When the aqueous clear coating composition is applied wet-on-wet, a mixed layer of the formed aqueous base coating film and clear coating film is formed.

  As volatile base compounds (C), ammonia, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, monobutylamine, dibutylamine, tributylamine and other alkylamines, Alkanol amines such as diethanolamine, diisopropanolamine, triethanolamine, dimethylethanolamine and diethylethanolamine, alkylene polyamines such as ethylenediamine, propylenediamine, diethylenetriamine and triethylenetetramine, ammonia, ethyleneimine, pyrrolidine, piperidine, piperazine, morpholine, etc. Is mentioned. Among these, as the volatile base compound (C), alkylamine or ammonia is preferably used, and ammonia is particularly preferably used from the viewpoint of easiness of volatilization during coating, which will be described later.

  The content of the volatile base compound (C) is preferably used in such an amount that the equivalent ratio of the volatile base compound (C) to the amine value of the polyfunctional amine polymer (B) is 1 to 5. 0.5 to 3 is more preferable. When the equivalent ratio is less than 1, the storage stability of the aqueous base coating composition is impaired, and there is a risk of thickening or gelation. Further, when the equivalent ratio exceeds 5, the aggregation due to the interaction of the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) becomes insufficient, and a mixed layer with the undried clear coating film May occur.

Viscosity modifier (D)
The aqueous base coating composition in the present invention preferably contains a specific viscosity modifier (D) in addition to the components (A) to (C). In the present invention, by using the specific viscosity modifier (D), the complex viscosity increase rate of the aqueous base coating composition is increased to 300 to 3,000% due to the interaction with the polyfunctional amine polymer (B). There is an advantage that it is possible to adjust well.

As an example of a preferred viscosity modifier,
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
Following formula (1)

In Expression (1), ^{R 1} is H or CH _3, ^{R 2} and ^{R 3} are each independently H or an alkyl group having a carbon number of 1 to 2, ^{R 4} is 1 to 60 carbon atoms An alkyl group having 7 to 20 carbon atoms, a phenylalkylphenyl group having 13 to 20 carbon atoms, a residue of an aromatic compound having a condensed cyclic structure having 9 to 14 carbon atoms, or di- or tri -Styrenated phenyl group, n is 3-100. ]
1 to 2 or more types of monomers represented by 1 to 60 parts by mass,
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
And an alkali-soluble viscosity modifier (d-1) having a weight average molecular weight of 100,000 to 500,000 obtained by copolymerization of

  Acrylic acid (salt) and / or methacrylic acid (salt) used for the preparation of the alkali-soluble viscosity modifier (d-1) may be used alone or in combination of two or more. Good. Bases in acrylic acid (salt) and / or methacrylic acid (salt) include alkali metal salts (sodium, potassium, lithium salts, etc.), alkaline earth metals (magnesium, calcium salts, etc.), ammonium salts and amine salts (mono Ethanolamine, diethanolamine, triethanolamine, alkyl (C1-C4) amine salts, etc.). Particularly preferred are sodium salts and potassium salts.

In the monomer represented by the above formula (1) used for the preparation of the alkali-soluble viscosity modifier (d-1), either one of R ² and R ³ is H, and the other is H Or it is preferable that it is a C1-C2 alkyl group. N is preferably 3-50.

As an example of a preferable group when R ⁴ is an alkyl group having 1 to 60 carbon atoms, an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group, a nonyl group, Examples include decyl group, lauryl group, tetradecyl group, cetyl group, stearyl group and the like. Here, it is more preferably an alkyl group having 1 to 4 carbon atoms, or an alkyl group having 5 to 20 carbon atoms, and further preferably an alkyl group having 1 to 4 carbon atoms.
Further, as another example of a preferable group when R ⁴ is an alkyl group having 1 to 60 carbon atoms, a linear or branched alkyl group having 25 to 60 carbon atoms such as pentacosyl, hexacosyl, heptacosyl, octacosyl , Nonacosyl, triacontyl, tetracontyl, pentacontyl, hexacontyl and the like.
Preferred groups when R ⁴ is an alkylphenyl group having 7 to 20 carbon atoms include, for example, methylphenyl group, ethylphenyl group, propylphenyl group, butylphenyl group, pentylphenyl group, hexylphenyl group, heptylphenyl group, Examples include 2-ethylhexylphenyl group, octylphenyl group, nonylphenyl group, decylphenyl group, dodecylphenyl group, tetradecylphenyl group, cetylphenyl group, octadecylphenyl group, laurylphenyl group and the like.
Preferred groups when R ⁴ is a phenylalkylphenyl group having 13 to 20 carbon atoms include, for example, phenylmethylphenyl group, phenylethylphenyl group, phenylpropylphenyl group, phenylbutylphenyl group, phenylpentylphenyl group, phenylhexyl. Examples thereof include a phenyl group, a phenylheptylphenyl group, a phenyloctylphenyl group, and a cumylphenyl group.
Preferable groups when R ⁴ is a residue of an aromatic compound having a condensed cyclic structure having 9 to 14 carbon atoms include, for example, an indenyl group, a naphthalinyl group, a tetralinyl group, an anthracenyl group, a phenanthrenyl group, and the like.

In the preparation of the alkali-soluble viscosity modifier (d-1), the monomer represented by the formula (1) may be used alone or in combination of two or more.
In the preparation of the alkali-soluble viscosity modifier (d-1), for example, when two or more monomers are used in combination as the monomer represented by the above formula (1), the following combinations are preferable:
(1) One of the monomers represented by the above formula (1) is such that R ⁴ is an alkyl group having 1 to ⁴ carbon atoms, and the other one of the monomers represented by the above formula (1) or A combination of two or more of which R ⁴ is an alkyl group having 5 to 20 carbon atoms, an alkylphenyl group having 7 to 20 carbon atoms, and / or a phenylalkylphenyl group having 13 to 20 carbon atoms,
(2) One type of the monomer represented by the above formula (1), R ⁴ is an alkyl group having 1 to ⁴ carbon atoms, and the other type of the monomer represented by the above formula (1) is , R ⁴ is a combination of aromatic compounds having a condensed cyclic structure having 9 to 14 carbon atoms,
(3) A combination in which two or more monomers represented by the above formula (1) are both monomers having different groups, although R ⁴ is an alkyl group having 1 to ⁴ carbon atoms,
(4) Two or more monomers represented by the above formula (1) both have different groups, although R ⁴ is a linear or branched alkyl group having 25 to 60 carbon atoms. A combination that is monomeric,
(5) One of the monomers represented by the above formula (1) is such that R ⁴ is a phenylalkylphenyl group having 13 to 20 carbon atoms, and other one of the monomers represented by the above formula (1). A species wherein R ⁴ is a di- or tri-styrenated phenyl group;
(6) One type of the monomer represented by the above formula (1), R ⁴ is an alkyl group having 5 to 20 carbon atoms, and the other type of the monomer represented by the above formula (1) is the combination ^{R 4} is an alkyl phenyl group having 7 to 20 carbon atoms.

  As specific examples of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms used for the preparation of the alkali-soluble viscosity modifier (d-1), methyl (meth) acrylate and (meth) Ethyl acrylate, butyl (meth) acrylate, pentyl (meth) acrylate and hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic acid n- Octyl, decyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, hexadecyl (meth) acrylate, stearyl (meth) acrylate Etc. These may be used alone or in combination of two or more.

  Specific examples of other copolymerizable ethylenically unsaturated monomers that can be used as needed in the preparation of the alkali-soluble viscosity modifier (d-1) include acrylamide, styrene, crotonic acid ( And unsaturated monocarboxylic acid (salt) such as maleic acid (salt) and fumaric acid (salt). These may be used alone or in combination of two or more.

In the preparation of the alkali-soluble viscosity modifier (d-1), acrylic acid (salt) and / or methacrylic acid (salt), a monomer represented by the above formula (1), an alkyl group having 1 to 20 carbon atoms (Meth) acrylic acid alkyl ester having a ratio of other ethylenically unsaturated monomers copolymerizable with these monomers in a total of 100 parts by mass of monomers,
Acrylic acid (salt) and / or methacrylic acid (salt) 25-90 parts by weight, preferably 27-85 parts by weight, more preferably 30-80 parts by weight,
1 to 60 parts by mass of the monomer represented by the above formula (1), preferably 5 to 55 parts by mass, more preferably 5 to 50 parts by mass,
(Meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms, 0 to 60 parts by mass, preferably 0 to 20 parts by mass, more preferably 0 to 15 parts by mass,
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these monomers, preferably 1-25 parts by mass, more preferably 1-15 parts by mass,
It is.
When the acrylic acid (salt) and / or methacrylic acid (salt) exceeds 90 parts by mass, the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) are mixed with each other in the aqueous base paint. The action becomes excessive, and the storage stability of the paint may be reduced.
When the monomer represented by the above (1) is less than 1 mass, an anionic aqueous resin dispersion (A) and a polyfunctional amine polymer (B) in an undried aqueous base coating film This interaction may not be sufficiently developed, and a mixed layer with a clear coating film to be subsequently provided may be likely to occur. On the other hand, when the amount exceeds 60 parts by mass, the interaction between the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) becomes excessive in the aqueous base paint, and the storage stability of the paint is improved. May decrease.
When the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms exceeds 60 parts by mass, the anionic aqueous resin dispersion (A) and polyfunctionality in the undried aqueous base coating film There is a possibility that the interaction with the amine polymer (B) does not sufficiently develop, and a mixed layer with a clear coating film to be subsequently provided tends to occur.
When the other ethylenically unsaturated monomer exceeds 30 parts by mass, the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) in the undried aqueous base coating film There is a possibility that the interaction does not sufficiently develop and a mixed layer with a clear coating film to be subsequently provided tends to occur.

  The alkali-soluble viscosity modifier (d-1) can be prepared by copolymerizing the above monomers. In the copolymerization, usual known methods such as solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization can be used. Preferably, solution polymerization and emulsion polymerization methods are used, and more preferably, emulsion polymerization methods are used.

  For example, in solution polymerization, the above monomer is used in water or / and an alcohol solvent (such as methanol, ethanol and isopropyl alcohol) at 40 to 130 ° C. in the presence of a commonly used polymerization initiator. After polymerizing for 15 hours, it can be easily obtained by neutralizing with a base if necessary. In addition, acid groups such as unsaturated monocarboxylic acids and unsaturated dicarboxylic acids possessed by methacrylic acid and other ethylenically unsaturated monomers are neutralized with a base before, during and after polymerization, if necessary. A method is also possible. As a polymerization method, the whole monomer mixture may be charged in a polymerization tank for polymerization, or may be charged while dropping. Further, a part of the monomer may be charged into the polymerization tank, and the polymerization may be performed while dropping another part of the monomer. The entire amount of the polymerization initiator may be charged in a polymerization tank for polymerization, or may be charged while dropping and polymerized.

  As polymerization initiators, 2,2′-azobisisobutyronitrile, 4,4′-azobis-4-cyanovaleric acid, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile, 2 , 2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-albonitrile), 2,2′-azobis (2,4,4-trimethylpentane), dimethyl 2,2 Azo series such as' -azobis (2-methylpropionate), 2,2'-azobis [2- (hydroxymethyl) propionitrile] and 1,1'-azobis (1-acetoxy-1-phenylethane) Catalysts, persulfates such as ammonium persulfate, potassium persulfate, sodium persulfate, inorganic peroxides such as perborate, hydrogen peroxide, ascorbic acid-hydrogen peroxide Docks catalyst, and an organic peroxide such as benzoyl peroxide. May be one kind or in combination of two or more thereof selected from these groups.

For example, in emulsion polymerization, the monomer mixture is mixed with an anionic surfactant, a nonionic surfactant, a known chain transfer agent for adjusting the degree of polymerization as required, acetaldehyde, isopropyl alcohol, dodecyl mercaptan or An additive such as hexadecyl mercaptan is added to water to disperse and emulsify, and the mixture is polymerized at 40 to 130 ° C. for 1 to 15 hours in the presence of a normal polymerization initiator, and then neutralized with a base as necessary. Can be prepared.
The total amount of the anionic surfactant and the nonionic surfactant used is preferably 5 to 15 parts by mass with respect to 100 parts by mass of the total monomers.

  The alkali-soluble viscosity modifier (d-1) thus prepared may be adjusted to a pH range of 6 to 13 using an arbitrary base as necessary. Examples of bases that can be used include alkali metal salts (sodium, potassium, lithium salts, etc.), alkaline earth metal salts (magnesium, calcium salts, etc.), ammonium salts, and amine salts (monoethanolamine, diethanolamine, triethanolamine). And alkylamine salts having an alkyl group having 1 to 4 carbon atoms).

By using the alkali-soluble viscosity modifier (d-1) as the viscosity modifier (D), the aqueous clear coating composition is wet-on-wet without preheating after coating the aqueous base coating composition. Even in the case of coating with, a coating film having good performance and appearance can be formed without causing problems such as mixed layers. This alkali-soluble viscosity modifier (d-1) is used in the aqueous base coating composition in which the aqueous base coating composition is applied, particularly due to the interaction with the polyfunctional amine polymer (B). The rate of increase in complex viscosity can be adjusted to 300 to 3,000%. Thereby, it is thought that wet-on-wet paintability improves. Further, when the alkali-soluble viscosity modifier (d-1) is used as the viscosity modifier (D), the alkali-soluble viscosity modifier (d-1) is a single amount represented by the above formula (1). It is thought that there is a specific effect derived from having a structure based on the body. That is, the R ⁴ group in the above formula (1) exhibits hydrophobicity in an undried aqueous base coating film obtained by application of the aqueous base coating composition, and thereby, the dried clear coating It is thought that a mixed layer preventing effect with the film is produced.

  The alkali-soluble viscosity modifier (d-1) preferably has a weight average molecular weight of 100,000 to 500,000, more preferably 150,000 to 400,000. When the weight average molecular weight is less than 100,000, aggregation due to the interaction of the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) in the aqueous base coating film in an undried state is insufficient. Then, there is a possibility that a mixed layer with a clear coating film to be subsequently provided tends to occur. On the other hand, when the weight average molecular weight exceeds 500,000, pseudo high molecular weight is excessively generated, and the storage stability of the coating composition may be lowered.

As another example of a preferable viscosity modifier that can be used in the aqueous base coating composition in the present invention, for example,
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
An alkali-soluble viscosity modifier (d-2) having a weight average molecular weight of 500,000 to 2,000,000 obtained by copolymerization of

  Preparation of the alkali-soluble viscosity modifier (d-2) is (meth) acryl having 25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt) and an alkyl group having 1 to 20 carbon atoms. Using 0-60 parts by mass of acid alkyl ester and 0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable therewith, in the same manner as the alkali-soluble viscosity modifier (d-1) Can be prepared.

In the preparation of the alkali-soluble viscosity modifier (d-2), acrylic acid (salt) and / or methacrylic acid (salt), (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms, and The proportion of other ethylenically unsaturated monomers that can be copolymerized is 100 parts by mass of the total monomer,
Acrylic acid (salt) and / or methacrylic acid (salt) 25-90 parts by weight, preferably 27-85 parts by weight, more preferably 30-80 parts by weight,
(Meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms, 0 to 60 parts by mass, preferably 0 to 20 parts by mass, more preferably 0 to 15 parts by mass,
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these monomers, preferably 5-30 parts by mass, more preferably 10-25 parts by mass,
It is.
When the acrylic acid (salt) and / or methacrylic acid (salt) exceeds 90 parts by mass, the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) are mixed with each other in the aqueous base paint. There is a possibility that the action becomes excessive and the storage stability of the paint is lowered.
When the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms exceeds 60 parts by mass, the anionic aqueous resin dispersion (A) and polyfunctionality in the undried aqueous base coating film There is a possibility that the interaction with the amine polymer (B) does not sufficiently develop, and a mixed layer with a clear coating film to be subsequently provided tends to occur.
When the other ethylenically unsaturated monomer exceeds 30 parts by mass, the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) in the undried aqueous base coating film There is a possibility that the interaction does not sufficiently develop and a mixed layer with a clear coating film to be subsequently provided tends to occur.

  By using the alkali-soluble viscosity modifier (d-2) as the viscosity modifier (D), the aqueous clear coating composition is wet-on-wet without preheating after coating the aqueous base coating composition. Even in the case of coating with, a coating film having good performance and appearance can be formed without causing problems such as mixed layers. This alkali-soluble viscosity modifier (d-2) is used in the aqueous base coating composition in which the aqueous base coating composition is applied, particularly by interaction with the polyfunctional amine polymer (B). The rate of increase in complex viscosity can be adjusted to 300 to 3,000%. Thereby, it is thought that wet-on-wet paintability improves. Further, when the alkali-soluble viscosity modifier (d-2) is used as the viscosity modifier (D), the alkali-soluble viscosity modifier (d-2) has a weight average molecular weight of 500,000 to 2,000. It is considered that there is a specific effect derived from having a large molecular weight of 1,000. That is, when the alkali-soluble viscosity modifier (d-2) has a high molecular weight, hydrophobicity is exhibited in an undried aqueous base coating film obtained by coating with an aqueous base coating composition. It is considered that the effect of preventing mixing with the clear coating film in an undried state is caused. When the weight average molecular weight is less than 500,000, the aggregation due to the interaction of the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) in the aqueous base coating film in an undried state is insufficient. Then, there is a possibility that a mixed layer with a clear coating film to be subsequently provided tends to occur. Moreover, when a weight average molecular weight exceeds 2,000,000, pseudo high molecular weight generation | occurrence | production arises excessively and there exists a possibility that the storage stability of a coating composition may fall. The weight average molecular weight is more preferably 750,000 to 1,500,000.

  The content of the viscosity modifier (D) contained in the aqueous base coating composition in the present invention is 0.1 to 10 parts by mass with respect to 100 parts by mass of the solid content of the anionic aqueous resin dispersion (A). Preferably there is. When content of a viscosity modifier (D) is less than 0.1 mass part, there exists a possibility that the preferable effect by viscosity modifier (D) addition may not be acquired. Moreover, when content of a viscosity modifier (D) exceeds 10 mass parts, there exists a possibility that excessive thickening may arise in an aqueous base coating composition, or the water resistance of the obtained coating film may fall. As for content of a viscosity modifier (D), it is more preferable that it is 0.5-5 mass parts with respect to 100 mass parts of solid content of anionic aqueous resin dispersion (A), and is 1-5 mass parts. More preferably.

  The aqueous base coating composition in the present invention may contain other components as required in addition to the components (A) to (D). Examples of other components include pigments, design materials (sand, dredged sand, colored sand, beads, colored chips, mineral chips, glass chips, wooden chips, colored beads, etc.), film-forming aids, surface conditioners, preservatives, Examples include antifungal agents, antifoaming agents, light stabilizers, ultraviolet absorbers, antioxidants, pH adjusters and the like.

  The pigment is not particularly limited, for example, an azo chelate pigment, an insoluble azo pigment, a condensed azo pigment, a monoazo pigment, a disazo pigment, a diketopyrrolopyrrole pigment, a benzimidazolone pigment, a phthalocyanine pigment, Indigo pigment, thioindigo pigment, perinone pigment, perylene pigment, dioxane pigment, quinacridone pigment, isoindolinone pigment, naphthol pigment, pyrazolone pigment, anthraquinone pigment, anthorapyrimidine pigment, metal complex Organic color pigments such as pigments: yellow lead, yellow iron oxide, chromium oxide, molybdate orange, bengara, titanium yellow, zinc white, carbon black, titanium dioxide, cobalt green, phthalocyanine green, ultramarine, cobalt blue, phthalocyanine blue, Cobalt bio Inorganic colored pigments such as iron; mica pigments (titanium dioxide-coated mica, colored mica, metal-plated mica); graphite pigments, alumina flake pigments, metal titanium flakes, stainless steel flakes, plate-like iron oxide, phthalocyanine flakes, metal-plated glass Examples include flakes, other colored and colored flat pigments; titanium oxide, calcium carbonate, barium sulfate, barium carbonate, magnesium silicate, clay, talc, silica, calcined kaolin extender pigments, and the like.

  When the aqueous base coating composition contains a pigment, the pigment mass concentration (PWC) with respect to the solid content of the aqueous base coating composition is preferably in the range of 5 to 70% by mass. When the PWC is less than 5% by mass, the base concealing property is inferior, and when the PWC exceeds 70% by mass, the weather resistance may be lowered. The pigment mass concentration (PWC) is more preferably 20 to 45% by mass.

  It does not specifically limit as a preparation method of a water-based base coating composition, It can prepare by stirring each component mentioned above with a stirrer etc. When pigments or design materials are included in the aqueous base coating composition, those having good dispersibility can be mixed with a stirrer, and as an alternative, a vehicle containing water, a surfactant or a dispersant can be sanded. What was previously disperse | distributed using a grind mill etc. can also be added.

  The aqueous base coating composition in the present invention preferably has a pH in the range of 8-11. When the pH of the aqueous base coating composition is less than 8, the storage stability of the coating composition is inferior, and there is a risk of thickening or gelling over time. On the other hand, when the pH exceeds 11, the aggregation due to the interaction of the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) becomes insufficient, and a mixed layer with the undried clear coating film is obtained. May occur. The pH of the aqueous base coating composition is more preferably in the range of 9-10.

  The aqueous base coating composition of the present invention can be used for coating various building materials in addition to ceramic building materials. For example, it can also be used for coating of wall surfaces or roofs of buildings such as houses and buildings, concrete, ALC, and other inorganic building materials.

Water-based clear coating composition Water-based clear coating composition is not particularly limited, for example, acrylic resin, alkyd resin, polyester resin, silicone-modified polyester resin, silicone-modified acrylic resin, epoxy resin, polycarbonate resin, silicate resin, fluororesin, A clear coating composition containing a resin component such as a chlorine-based resin or a polyolefin resin can be used.

  Water-based clear coating compositions can be used as needed, such as cross-linking agents, viscosity modifiers, fillers, dispersants, UV absorbers, light stabilizers, antioxidants, antifreeze agents, algae-proofing agents, antifoaming agents, A film aid, surface conditioner, antiseptic, fungicide, pH adjuster, pigment, delustering agent (gloss adjuster), colored aggregate, colored mica, and the like may also be included.

  It does not specifically limit as a preparation method of a water-based clear coating composition, It can carry out by stirring each compound mentioned above with a stirrer etc.

Ceramic building material for forming a multilayer coating film The present invention provides a method of forming a multilayer coating film ceramic building materials. And the method of the present invention comprises the following steps:
In the ceramic building materials production line, a process of forming an aqueous base coating film by applying an aqueous base coating composition to an object to be coated;
A step of applying a water-based clear coating composition on the obtained aqueous base coating film by wet-on-wet to form a clear coating film, and a step of simultaneously drying the obtained aqueous base coating film and the clear coating film;
Is included.
In the multilayer coating film forming method, the above-described aqueous base coating composition and aqueous clear coating composition are used.

  The article to be coated used in the method of the present invention is a ceramic building material (ceramic siding) used as an outer wall finishing material. Here, ceramic building materials (ceramic siding) are manufactured by molding into a plate shape using cement, siliceous raw materials, fibrous raw materials, admixtures, and the like, and drying (curing / curing). JIS A 5422 The building materials specified in the above.

  The building material is preferably preliminarily coated with an undercoat (sealer) or the like for the purpose of improving adhesion or imparting waterproofness. Moreover, the coating composition for back surfaces may be painted on the back surface of the building material. These can be appropriately selected from commonly used coating compositions according to the purpose of use.

  In the method of the present invention, an aqueous base coating composition is formed on an object to be coated in a ceramic building material production line to form an aqueous base coating film. The method for applying the aqueous base coating composition is not particularly limited. For example, commonly used coatings such as dipping, brush, roller, roll coater, air spray, airless spray, curtain flow coater, roller curtain coater, die coater, etc. The method etc. can be used. The aqueous base coating composition is preferably applied so that the dry film thickness of the aqueous base coating film is 5 to 350 μm. The dry film thickness of the aqueous base coating film is more preferably 20 to 300 μm.

The method of the present invention is characterized in that the aqueous clear coating composition is applied without drying the aqueous base coating film obtained by applying the aqueous base coating composition using special means.
The aqueous base coating composition in the present invention contains an anionic aqueous resin dispersion (A), a polyfunctional amine polymer (B), a volatile base compound (C), and a viscosity modifier (D) as necessary. And in the state in which these components are contained, an anionic aqueous resin dispersion (in particular) when the equivalent ratio of the volatile base compound (C) to the polyfunctional amine polymer (B) is 1 to 5. A stable dispersion state is maintained without interaction between A) and the polyfunctional amine polymer (B). On the other hand, when the aqueous base coating composition is applied to the ceramic building material in the ceramic building material production line, the volatile base compound (C) contained in the coating composition is volatilized. In a ceramic building material production line, this is generally a non-metallic material with a high thermal storage property formed of cement, siliceous raw material, fibrous raw material, admixture, etc., having a thickness of about 0.5 to 10 cm. Apply a sealer in advance, for example, a process of heating and drying at 30 to 80 ° C. for about 1 to 5 minutes to form a sealer coating, or a sealer coating is formed in advance on the surface of a building material as an object to be coated Also when using the made building materials, it originates in the process of preheating at 30-80 degreeC on the conditions for about 1 to 5 minutes. For this reason, at the time of applying the aqueous base coating composition, the article to be coated generally has a temperature of 40 ° C. or higher, more specifically, about 40 to 60 ° C. Therefore, the volatile base compound (C) contained in the coating composition volatilizes very easily after coating on the building material. When the volatile base compound (C) is volatilized, an interaction between the anionic aqueous resin dispersion (A) and the polyfunctional amine polymer (B) occurs, and these components form a matrix (pseudo-aggregation). Formed, resulting in a pseudo-high molecular weight. Thereby, the viscosity of a coating composition will rise rapidly. Thus, after applying the aqueous base coating composition, even when the aqueous clear coating composition is applied wet-on-wet without drying the obtained aqueous base coating film, It is possible to effectively prevent a mixed layer between the two, and to obtain a good multilayer coating film. Moreover, a viscosity modifier (D) can assist said interaction and can obtain a more favorable multilayer coating film.

  In the multilayer coating film forming method of the present invention, the following aqueous clear coating composition is applied wet-on-wet without heating and drying the base coating obtained by applying the aqueous base coating composition, Form a coating film. For example, after the aqueous base coating composition is applied at room temperature (for example, 10 to 30 ° C.), the aqueous clear coating composition is applied within 0 to 10 minutes, preferably within 1 to 5 minutes.

  The method for applying the aqueous clear coating composition is not particularly limited. For example, commonly used coating such as dipping, brush, roller, roll coater, air spray, airless spray, curtain flow coater, roller curtain coater, die coater, etc. The method etc. can be used. The aqueous clear coating composition is preferably applied so that the dry film thickness of the clear coating film is 5 to 350 μm. The dry film thickness of the clear coating film is more preferably 20 to 300 μm.

  Next, the obtained aqueous base coating film and clear coating film are simultaneously dried. This drying can be performed, for example, by heating at 60 to 150 ° C., preferably 80 to 130 ° C. for 30 seconds to 10 minutes. In this way, in a ceramic building materials production line, even after applying an aqueous base paint composition, even if an aqueous clear paint composition is applied without performing a special drying process, a good coating film appearance is not caused without problems such as mixed layers. It is possible to form a multilayer coating film having

  The following examples further illustrate the present invention, but the present invention is not limited thereto. In the examples, “parts” and “%” are based on mass unless otherwise specified.

Production Example B-1 Production of polyfunctional amine polymer (B-1) In a glass reaction vessel equipped with a dropping funnel, a reflux condenser, a stirrer, a thermometer and a nitrogen introduction tube, 550 parts of deionized water and 99 0.5 parts of 8% acetic acid was added and the temperature of the contents was 85 ° C. Among them, methyl acrylate 20 parts, acrylamide 30 parts, acrylic acid 5 parts, amine functional group-containing monomer 45 parts monoallylamine, chain transfer agent 2-ethylhexyl thioglycolate 2 parts, 99.8% acetic acid 0 .5 parts of a monomer mixture, 0.5 part of V-50 (2,2′-Azobis (2-methylpropionamidine) dihydrochloride, manufactured by Pharmacological Pure Chemicals) and 20 parts of deionized water as a polymerization initiator The resulting polymerization initiator aqueous solution was dropped at a constant rate over 3 hours to cause a reaction.
The reaction temperature was maintained at 85 ° C. After the completion of the dropwise addition, the temperature was kept at the same temperature for 3 hours, and then cooled to 30 ° C., 25% aqueous ammonia solution was added to adjust the pH to 9.0, the non-volatile content was 14.8%, the amine value was 415 mgKOH / g, and the weight average molecular weight. 9,200 polyfunctional amine polymer (aqueous solution) B-1 was obtained.

Production Example B-2 Production of polyfunctional amine polymer (B-2) In a glass reaction vessel equipped with a dropping funnel, a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet, 400 parts of deionized water and the reaction 0.5 parts by weight of Aqualon HS10 (Daiichi Kogyo Seiyaku Co., Ltd.) was added as a functional emulsifier, and the temperature of the contents was 85 ° C. Among them, 15 parts of methyl methacrylate, 10 parts of nbutyl acrylate, 30 parts of acrylamide, 5 parts of acrylic acid, 40 parts of dimethylaminoethyl methacrylate as an amine functional group-containing monomer, 1 part of 2-ethylhexyl thioglycolate, 99 A monomer mixture composed of 0.5 part of 8% acetic acid and a polymerization initiator aqueous solution composed of 0.5 part of V-50 and 20 parts of deionized water as a polymerization initiator were dropped at a constant rate over 3 hours. , Reacted.
The reaction temperature was maintained at 85 ° C. After the completion of dropping, the temperature was kept at the same temperature for 3 hours, and then cooled to 30 ° C., 25% aqueous ammonia solution was added to adjust the pH to 9.0, non-volatile content 19.1%, amine value 143 mgKOH / g, weight average molecular weight 156,000 polyfunctional amine polymer (aqueous dispersion) B-2 was obtained.

Multifunctional amine polymers (B-3) and (B-4)
The following were used as the polyfunctional amine polymers (B-3) and (B-4).

Multifunctional amine polymer (B-3)
SP-018 (polyethyleneimine manufactured by Nippon Shokubai Co., Ltd., amine value 1,280 mgKOH / g, weight average molecular weight 2,150) was used as the polyfunctional amine polymer (aqueous solution) B-3.

Multifunctional amine polymer (B-4)
PAS-92 (diallylamine manufactured by Nittobo Co., Ltd., hydrochloride of a copolymer with sulfur dioxide (concentration 20%), amine value 552 mgKOH / g, weight average molecular weight 4,800) was added to a polyfunctional amine polymer (aqueous solution). ) Used as B-4.

Comparative Production Example B-5 Production of polyfunctional amine polymer (B-5) Deionized water in a glass reaction vessel equipped with a dropping funnel, reflux condenser, stirring device, thermometer, nitrogen inlet tube and dropping funnel 550 parts and 0.5 part of 99.8% acetic acid were added and the temperature of the contents was 85 ° C. It consists of 20 parts of methyl acrylate, 20 parts of methyl methacrylate, 50 parts of acrylamide, 5 parts of acrylic acid, 5 parts of monoallylamine, 2 parts of 2-ethylhexyl thioglycolate and 0.5 part of 99.8% acetic acid. The polymer mixture and a polymerization initiator aqueous solution consisting of 0.5 part of V-50 (manufactured by Pharmacological Pure Chemicals) as a polymerization initiator and 20 parts of deionized water were dropped at a constant rate over 3 hours to be reacted. .
The reaction temperature was maintained at 85 ° C. After maintaining the same temperature for 3 hours after the completion of the dropwise addition, the mixture was cooled to 30 ° C., and 25% aqueous ammonia solution was added to adjust the pH to 9.0, the non-volatile content was 14.8%, the amine value was 43 mgKOH / g, the weight average molecular weight was 11, 300 polyfunctional amine polymer (aqueous solution) B-5 was obtained.

Comparative Production Example B-6 Production of polyfunctional amine polymer (B-6) In a glass reaction vessel equipped with a dropping funnel, a reflux condenser, a stirrer, a thermometer and a nitrogen inlet, 400 parts of deionized water and As a reactive emulsifier, 0.5 part by weight of Aqualon HS10 (Daiichi Kogyo Seiyaku Co., Ltd.) was added, and the temperature of the contents was 85 ° C. Among them, 15 parts of methyl methacrylate, 10 parts of n-butyl acrylate, 10 parts of acrylamide, 5 parts of acrylic acid, 60 parts of dimethylaminoethyl methacrylate as an amine functional group-containing monomer, 0.5 part of 99.8% acetic acid A monomer mixture solution and a polymerization initiator aqueous solution consisting of 0.5 parts of V-50 (manufactured by Pharmacological Pure Chemicals) and 20 parts of deionized water as a polymerization initiator are added dropwise at a constant rate over 3 hours to react. I let you.
The reaction temperature was maintained at 85 ° C. After maintaining the same temperature for 3 hours after the completion of the dropwise addition, the mixture was cooled to 30 ° C., 25% aqueous ammonia solution was added to adjust the pH to 9.0, the non-volatile content was 19.2%, the amine value was 237 mgKOH / g, the weight average molecular weight was 314. 600 polyfunctional amine polymer (water dispersion) B-6 was obtained.

Production Example D-1 Production of Alkali-Soluble Type Viscosity Adjusting Agent (d-1 (I)) Deionized water in a glass reaction vessel equipped with a dropping funnel, reflux condenser, stirring device, thermometer and nitrogen inlet 100 parts by weight and 1.5 parts of emulsifier A and 1.5 parts of emulsifier C as reactive emulsifiers were added, and the temperature of the contents was 85 ° C. Among them, 40 parts of methacrylic acid, 32 parts of component I- (1) shown in Table 2 below, 13 parts of I- (2), 10 parts of ethyl methacrylate, 5 parts of butyl methacrylate, thiocalcol 20 0.2 2 parts of a pre-emulsion solution consisting of 4 parts of emulsifier A, 4 parts of emulsifier C and 122 parts of deionized water, and an aqueous polymerization initiator solution consisting of 0.5 parts of ammonium persulfate and 10 parts of deionized water as a polymerization initiator The solution was added dropwise at a constant rate to cause reaction. The reaction temperature was maintained at 85 ° C.
After the completion of the dropping, the temperature was kept at the same temperature for 3 hours, and then the mixture was cooled to 30 ° C. to obtain an alkali-soluble viscosity modifier d-1 (A) having a nonvolatile content of 30% and a weight average molecular weight of 254,000.
As the emulsifiers A to D, those shown in Table 3 below were used.

Production Examples D-2 to D-12 Alkali-soluble viscosity modifiers (d-1 (b) to (f), d-2 (g) to (ri), d-3 (nu) to (wo)) In Preparation Production Examples D-2 to 12, the reactive emulsifier, the pre-emulsification liquid and the polymerization initiator aqueous solution were changed to the blends shown in Table 1 below in the same procedure as in Production Example D-1, A soluble viscosity modifier was produced.
Components I- (1) to (14) were those shown in Table 2 below, and emulsifiers A to D were those shown in Table 3 below.

Example 1
Manufacture of aqueous base coating composition BYK190 (manufactured by Big Chemie) as a pigment dispersant, 50 parts of titanium oxide (titanium CR-95, manufactured by Ishihara Sangyo Co., Ltd.) as a pigment for white paint, precipitated barium sulfate (precipitated sulfuric acid) Ritabond ES-85 (acrylic resin, manufactured by Chuo Rika Kogyo Co., Ltd.) as an anionic aqueous resin dispersion (A) to titanium white dispersion paste comprising 40 parts of barium # 100, manufactured by Sakai Chemical Co., Ltd. and 20 parts of deionized water 196 parts), 20.3 parts B-1 as a polyfunctional amine polymer (B), and 3% 25% aqueous ammonia solution as a volatile base compound (C) The parts were mixed sequentially. Furthermore, 1 part of SANOL LS292 (manufactured by Sankyo) as a hindered amine light stabilizer, 10 parts of texanol (manufactured by Eastman) as a film-forming aid, and 222.4 parts of deionized water were mixed. Finally, ASE-60 (manufactured by Rohm & Haas) was added as a thickener so as to be 30 seconds in an NK2 cup to obtain an aqueous base coating composition 1.

Manufacture of aqueous clear coating composition 196 parts of Ricabond ES-85 (acrylic resin emulsion, manufactured by Chuo Rika Kogyo Co., Ltd., acid value 8 mgKOH / g, solid content concentration 51.0%) as an anionic aqueous resin dispersion, film forming aid 10 parts of texanol (manufactured by Eastman Co.) as an agent, 2 parts of tinuvin 1130 (manufactured by Ciba Specialty Chemicals Co., Ltd.), 2 parts of sanol LS292 (manufactured by Sankyo Co., Ltd.) as a hindered amine light stabilizer and 104 deionized water Further, ASE-60 (manufactured by Rohm & Haas) was added as a thickener so as to be 30 seconds in an NK2 cup to obtain an aqueous clear coating composition.

Examples 2 to 21 and Comparative Examples 1 to 4
According to the description in Table 4, Table 5, and Table 6, water-based base coating compositions 2 to 25 were produced in the same manner as in Example 1. In addition, all the compounding quantities of Table 4, Table 5, and Table 6 represent a solid content mass part.

Comparative Example 5
According to the description in Table 6, an aqueous base coating composition 26 was produced in the same manner as in Example 1 except that NaOH was used instead of the volatile base compound (C).

Comparative Example 6
According to the description in Table 6, an aqueous base coating composition was prepared in the same manner as in Example 1 except that triethylamine (molecular weight 101, amine value 555), which is an amine compound, was used instead of the polyfunctional amine polymer (B). 27 was produced.

  The aqueous base coating composition obtained above was subjected to an evaluation test according to the following items.

Paint workability (interlayer resistance)
The aqueous base coating composition in each example and comparative example was applied to a glass plate with a doctor blade (6 mil) and set on a hot plate at 40 ° C. for 2 minutes to form a base coating film. Thereafter, the coating film was submerged in a water tank filled with tap water for 30 seconds, pulled up, and then visually evaluated for the coating film state after standing for 10 minutes in a vertical state. The coating workability was evaluated at a constant temperature and humidity of 23 ° C./60%.
5 No abnormality 4 Partially dissolved part (about 1-5%) of the film submerged part 3 Part of the submerged part of the film partly dissolved 2 Part of the submerged part of the film partly dissolved 1 Part of the submerged part of the paint film Completely dissolved

Storage Stability The aqueous base coating compositions of each Example and Comparative Example were evaluated according to the following criteria, according to the following criteria, according to the heating stability test defined in JIS K 5600-2-7. .
5 No abnormality 3 Minor thickening was observed 3 Thickening was observed, skin burr was observed 2 Significant thickening was observed, Skin burr was observed 1 Remarkable thickening was observed, gelation occurred The

Measurement of Complex Viscosity The rate of increase in complex viscosity was determined by measuring the complex viscosity (η ₀ ) at the start of measurement and the complex viscosity (η ₁ ) 10 minutes after the start of measurement of each of the aqueous base coating compositions of the Examples and Comparative Examples. And the following formula:
Complex viscosity increase rate = η ₁ / η ₀ × 100
I asked for it.
The complex viscosity was measured as follows. An aqueous base coating composition is placed in a measurement cell of a viscoelasticity measuring apparatus so as to have a thickness of 0.6 mm, on which a width of 2 mm, an annular body thickness of 4 mm, a height of 3 mm, and a support body thickness of 1 mm. A viscoelasticity measuring jig having a circular body with an inner diameter of 46 mm and an outer diameter of 50 mm was put in a sample to a depth of 0.1 mm. Then, the plate temperature is set to 40 ° C., an angular frequency of 6.3 rad / s is applied to the sample, the torque is measured, and the phase difference between the sinusoidal angular displacement and the torque-angular displacement is measured, and the complex of the sample is measured. The viscosity was determined. As a viscoelasticity measuring device, Physica MCR 301 (manufactured by Anton Paar), which is a stress-controlled viscoelasticity measuring device, was used, and the viscoelasticity measuring jig was in the form shown in FIG. A notch portion 6 having an area of 73% (made of stainless steel SUS304) was used.

In each of the aqueous base coating compositions used in Examples 1 to 21, the complex viscosity increase rate after 10 minutes from the start of viscosity measurement was in the range of 300 to 3,000%. And by applying such an aqueous base coating composition in a ceramic building material production line, the aqueous base coating composition is coated and then the aqueous clear coating composition is dried without drying the obtained aqueous base coating film. Even if the coating was applied, a multilayer coating film having a good appearance could be formed without causing problems such as mixed layers.
Comparative Example 1 is an experimental example using an aqueous base coating composition that does not contain the polyfunctional amine polymer (B) and has a complex viscosity increase rate of less than 300%. In this case, the interlaminar resistance was poor.
Comparative Example 2 is an experimental example using an aqueous base coating composition in which the polyfunctional amine polymer (B) has a low amine value and a complex viscosity increase rate of less than 300%. Also in this case, the interlaminar resistance was poor.
Comparative Example 3 is an experimental example using an aqueous base coating composition in which the polyfunctional amine polymer (B) has a high amine value and the complex viscosity increase rate exceeds 3,000%. In this case, the storage stability of the coating composition was remarkably inferior.
Comparative Example 4 is an experimental example using an aqueous base coating composition having a small content of the volatile base compound (C) and a complex viscosity increase rate exceeding 3,000%. Also in this case, the storage stability of the coating composition was remarkably inferior.
Comparative Example 5 is an experimental example using an aqueous base coating composition containing NaOH instead of the volatile base compound (C) and less than 300%. Also in this case, the interlaminar resistance was poor.
Comparative Example 6 is an experimental example using an aqueous base coating composition containing triethylamine, which is an amine compound, instead of the polyfunctional amine polymer (B). Also in this case, the interlaminar resistance was poor.

As a multi-layer coating film forming method sealer, a flat plate (ceramic building material manufactured by Ube Board Co., Ltd.) previously coated with an odeite 128 sealer (manufactured by Nippon Paint Co., Ltd.) so as to have a dry film thickness of 50 μm is used. After heating to a surface temperature of 50 ° C., the aqueous base coating composition 1 obtained in Example 1 was applied by spraying to a dry film thickness of 40 μm to form an aqueous base coating film. Next, the aqueous clear coating composition used in Examples 1 to 21 was applied onto the undried aqueous base coating obtained above by spraying to a dry film thickness of 50 μm, and the resulting aqueous base coating was obtained. The clear coating film was dried at 100 ° C. for 10 minutes to form a multilayer coating film. The obtained multilayer coating film had a good appearance without a mixed layer of an aqueous base coating film and a clear coating film.

  On the other hand, when the multilayer coating film was formed in the same manner as described above using the aqueous base coating compositions obtained in Comparative Examples 1, 2, 5, and 6, the resulting multilayer coating film was obtained as an aqueous base coating film. A mixed layer with the clear coating was observed. In Comparative Examples 3 and 4, the storage stability of the aqueous base coating composition was inferior, so such evaluation was not performed.

In the method for forming a multilayer coating film for ceramic building materials of the present invention, the aqueous clear coating composition can be applied wet-on-wet without drying the obtained aqueous base coating film after applying the aqueous base coating composition. This makes it possible to omit the drying step, which is necessary in the case of using a conventional coating composition, after applying the aqueous base coating composition and before applying the aqueous clear coating composition. The multi-layer coating film forming method of the present invention can achieve reduction of equipment maintenance cost and energy cost, reduction of environmental load (energy saving, CO ₂ emission reduction), and further shortening of the painting process. Has the industrial advantage of being able to

  1: jig for measuring viscoelasticity, 2: rotating shaft, 3: circular body, 4: annular body, 5: support, 6: notch.

Claims (6)

In the ceramic building materials production line, a process of forming an aqueous base coating film by applying an aqueous base coating composition to an object to be coated;
A step of applying a water-based clear coating composition on the obtained aqueous base coating film by wet-on-wet to form a clear coating film, and a step of simultaneously drying the obtained aqueous base coating film and the clear coating film;
A multilayer coating film forming method for ceramic building materials,
The aqueous base coating composition comprises an anionic aqueous resin dispersion (A), a water-soluble or water-dispersible polyfunctional amine polymer (B), and a volatile base compound (C).
The water-based base coating composition uses a viscoelasticity measuring jig which is a circular body having a cut-out portion of 40 to 80% of the projected area in the rotation axis direction, using a jig at a temperature of 40 ° C. and an angular frequency of 6.3 rad / When the complex viscosity is measured under the condition of s, the complex viscosity increase rate after 10 minutes from the start of measurement is 300 to 3,000%.
A method for forming a multilayer coating film for ceramic building materials.   The multilayer coating film forming method for ceramics building materials according to claim 1, wherein the aqueous base coating composition further contains a viscosity modifier (D). The polyfunctional amine polymer (B) is a water-soluble or water-dispersible polyfunctional amine polymer having a weight average molecular weight of 500 to 300,000 and an amine value of 100 to 1,300 mgKOH / g,
The volatile base compound (C) is an alkylamine or ammonia;
The viscosity modifier (D) is
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
Following formula (1)

In Expression (1), ^{R 1} is H or CH _3, ^{R 2} and ^{R 3} are each independently H or an alkyl group having a carbon number of 1 to 2, ^{R 4} is 1 to 60 carbon atoms An alkyl group having 7 to 20 carbon atoms, a phenylalkylphenyl group having 13 to 20 carbon atoms, a residue of an aromatic compound having a condensed cyclic structure having 9 to 14 carbon atoms, or di- or tri -Styrenated phenyl group, n is 3-100. ]
1 to 2 or more types of monomers represented by 1 to 60 parts by mass,
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
Or an alkali-soluble viscosity modifier (d-1) having a weight average molecular weight of 100,000 to 500,000, obtained by copolymerization of
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
An alkali-soluble viscosity modifier (d-2) having a weight average molecular weight of 500,000 to 2,000,000, obtained by copolymerization of
The equivalent ratio of the volatile base compound (C) to the amine value of the polyfunctional amine polymer (B) is 1 to 5,
The method for forming a multilayer coating film for ceramic building materials according to claim 2 . The anionic aqueous resin dispersion (A) is at least one selected from the group consisting of an acrylic resin emulsion, a silicone-containing acrylic resin emulsion, a urethane resin emulsion, a vinyl acetate resin emulsion, a fluororesin emulsion, and a vinyl chloride resin emulsion. An anionic aqueous resin dispersion having an acid value of 5 to 30 mg KOH / g,
The multilayer coating-film formation method for ceramics building materials in any one of Claims 1-3. The content of the polyfunctional amine polymer (B) contained in the aqueous base coating composition is 0.5 to 8 parts by mass with respect to 100 parts by mass of the solid content of the anionic aqueous resin dispersion (A). Yes,
The content of the viscosity modifier (D) contained in the aqueous base coating composition is 0.1 to 10 parts by mass with respect to 100 parts by mass of the solid content of the anionic aqueous resin dispersion (A).
The method for forming a multilayer coating film for ceramics building materials according to any one of claims 2 to 4. An anion having an acid value of 5 to 30 mg KOH / g, which is at least one selected from the group consisting of acrylic resin emulsion, silicone-containing acrylic resin emulsion, urethane resin emulsion, vinyl acetate resin emulsion, fluororesin emulsion and vinyl chloride resin emulsion Water-based resin dispersion (A),
A water-soluble polyfunctional amine polymer (B) having a weight average molecular weight of 500 to 300,000 and an amine value of 100 to 1300 mgKOH / g,
A volatile base compound (C) which is an alkylamine or ammonia, and
Viscosity modifier (D),
A water-based base coating composition for wet-on-wet ceramics building material coating,
The viscosity modifier (D) is
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
Following formula (1)

In Expression (1), ^{R 1} is H or CH _3, ^{R 2} and ^{R 3} are each independently H or an alkyl group having a carbon number of 1 to 2, ^{R 4} is 1 to 60 carbon atoms An alkyl group having 7 to 20 carbon atoms, a phenylalkylphenyl group having 13 to 20 carbon atoms, a residue of an aromatic compound having a condensed cyclic structure having 9 to 14 carbon atoms, or di- or tri -Styrenated phenyl group, n is 3-100. ]
1 to 2 or more types of monomers represented by 1 to 60 parts by mass,
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
Or an alkali-soluble viscosity modifier (d-1) having a weight average molecular weight of 100,000 to 500,000, obtained by copolymerization of
25 to 90 parts by mass of acrylic acid (salt) and / or methacrylic acid (salt);
(0) 60 parts by mass of (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms;
0-30 parts by mass of other ethylenically unsaturated monomers copolymerizable with these,
An alkali-soluble viscosity modifier (d-2) having a weight average molecular weight of 500,000 to 2,000,000, obtained by copolymerization of
Content of this polyfunctional amine polymer (B) is 0.5-8 mass parts with respect to 100 mass parts of solid content mass of this anionic aqueous resin dispersion (A),
Content of this viscosity modifier (D) is 0.1-10 mass parts with respect to 100 mass parts of solid content of this anionic aqueous resin dispersion (A), and this polyfunctional amine polymer ( The equivalent ratio of the volatile base compound (C) to the amine value of B) is 1 to 5,
Wet-on-wet water-based base coating composition for ceramic building materials.

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