Aqueous filler composition

Abstract

To provide an aqueous filler composition that forms a ground coating film provided with cracking resistance, without causing adverse effect on finishing properties of subsequent top coat paint, excellent in coating work, and less in concealment unevenness, even when a wool roller is used.SOLUTION: An aqueous filler composition used to form a ground coating film using a wool roller prior to applying a top coat paint, comprises an aqueous resin (A) with a glass transition temperature of 30°C or lower, carbon black paste (B), pigment (C), urethane associative thickener (D), and water, where the pigment volume concentration is in the range of 30 to 65%. The content of the urethane associative thickener (D) is 0.1 to 2.5 pts.mass in an effective component amount based on 100 pts.mass of the resin solid content in the aqueous filler composition, and the brightness of the coating film formed by the aqueous filler composition is in the range of 70 to 92.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a paint composition for substrate adjustment.

Background Art

[0002] Conventionally, in the painting finish of the outer wall of a building, substrate adjustment is performed before applying a topcoat that provides weather resistance and aesthetic appearance. As a material used for substrate adjustment, there is a synthetic resin emulsion-based substrate conditioner generally called an aqueous filler in the field of architectural paints.

[0003] Since the outer wall of a building may expand and contract due to temperature changes, or may develop cracks or the like over a long period of time, a thermoplastic synthetic resin emulsion is used in the substrate conditioner to impart elasticity that can follow the substrate.

[0004] As an aqueous filler, the applicant has proposed in Patent Documents 1 and 2 an aqueous paint composition containing a copolymer dispersion liquid and a pigment, wherein the copolymer dispersion liquid contains an acrylate containing a linear or branched alkyl group and a polymerizable unsaturated monomer containing a carbonyl group as copolymerization components, the copolymerization ratio of the acrylate containing a linear or branched alkyl group is 50% by mass or more, and the pigment volume concentration in the composition is in the range of 15 to 60%.

[0005] Further, Patent Document 3 discloses an undercoat paint containing an aqueous resin and a pigment for forming an undercoat film that contacts the lower side of an aqueous topcoat film, wherein the pigment contains an extender pigment A having an average particle diameter of 1 to 30 μm and an extender pigment B having an average particle diameter of 73 to 300 μm, the volume concentration of the extender pigment A in the total volume of the aqueous resin and the pigment is 13% or more, the volume concentration of the extender pigment B is 17% or more, and the combined volume concentration of the extender pigment A and the extender pigment B is 30 to 80%.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, since the painting roller scatters less during painting compared to spray painting, it is widely used for painting buildings. There are fibrous types and dedicated types such as porous rollers for painting rollers. Among them, fibrous types include wool rollers such as high-pile rollers and woolen rollers. They are inexpensive, have a high working speed, and can apply thin coats, so they are often used. On the other hand, for applying aqueous fillers, a porous roller that can apply thick coats and can adjust fine cracks and unevenness on the base with a pattern by painting is often used. Porous rollers are also called sandpaper rollers, mastic rollers, pattern rollers, or sponge rollers, and are rollers with a mesh-like hole structure in the roller pile part. This type of roller has the characteristics that it can hold a large amount of paint at one time and can apply a pattern with unevenness such as wavy patterns. However, porous rollers are more expensive than wool rollers or brushes, and require a large amount of paint for painting. Therefore, there are problems such as storage problems at the painting site and an increased weight load on the object to be painted due to an increased amount of paint applied to the object to be painted. Also, when it is desired to utilize the design of the existing outer wall, thin base adjustment may be required in some cases.

[0008] In response to such demands, when applying an aqueous filler as described in Patent Documents 1 to 3 using a wool roller, problems occur such that the paint does not adhere uniformly to the wall surface, hiding unevenness is likely to occur, roughness occurs on the surface of the paint film, and the finish of the topcoat applied thereon is inferior.

[0009] The present invention has been made in view of the above circumstances, and even when a wool roller is used, it has good coating workability, little hiding unevenness, and does not adversely affect the finish of the topcoat paint applied thereon, and provides an aqueous filler composition that forms a base coat film having crack resistance.

Means for Solving the Problems

[0010] As a result of intensive studies to solve the above problems, the present inventor has found that an aqueous resin (A) having a glass transition temperature of 30°C or lower, a carbon black paste (B), a pigment (C), a urethane associative thickener (D), and water are included, the pigment volume concentration is in the range of 30 to 65%, the content of the urethane associative thickener (D) is in the range of 0.1 to 2.5 parts by mass based on 100 parts by mass of the resin solid content contained in the aqueous filler composition, and the lightness of the coating film formed by the aqueous filler composition is in the range of 70 to 92. The present invention has been completed by finding that the above problems can be solved by the aqueous filler composition.

[0011] That is, the present invention includes the following embodiments. Item 1. An aqueous filler composition for forming a base coat film using a wool roller prior to applying a topcoat paint, containing an aqueous resin (A) having a glass transition temperature of 30°C or lower, a carbon black paste (B), a pigment (C), a urethane associative thickener (D), and water, the pigment volume concentration being in the range of 30 to 65%, the content of the urethane associative thickener (D) being 0.1 to 2.5 parts by mass in terms of the active ingredient amount based on 100 parts by mass of the resin solid content contained in the aqueous filler composition, and the lightness of the coating film formed by the aqueous filler composition being in the range of 70 to 92. Item 2. The aqueous resin (A) having a glass transition temperature of 30°C or lower is a copolymer (A1) of polymerizable unsaturated monomers containing neither a carbonyl group-containing polymerizable unsaturated monomer nor an alkoxysilyl group-containing polymerizable unsaturated monomer, and Copolymer (A2) of polymerizable unsaturated monomers containing a carbonyl group and polymerizable unsaturated monomers containing an alkoxysilyl group The aqueous filler composition according to Item 1, comprising the same. Item 3. The aqueous resin (A) having a glass transition temperature of 30°C or lower is Copolymer (A1) of polymerizable unsaturated monomers containing neither a carbonyl group nor an alkoxysilyl group, and Copolymer (A3) of polymerizable unsaturated monomers containing a carbonyl group and not containing an alkoxysilyl group The aqueous filler composition according to Item 1, comprising the same. Item 4. The aqueous resin (A) having a glass transition temperature of 30°C or lower is Copolymer (A3-1) of polymerizable unsaturated monomers having a glass transition temperature of less than 0°C and containing a carbonyl group and not containing an alkoxysilyl group, and Copolymer (A3-2) of polymerizable unsaturated monomers having a glass transition temperature of 0°C or higher and containing a carbonyl group and not containing an alkoxysilyl group The aqueous filler composition according to Item 1, comprising the same. Item 5. The carbon black paste (B) contains carbon black and water, and the carbon black concentration is in the range of 5 to 50% by mass in the carbon black paste (B). The aqueous filler composition according to any one of Items 1 to 4. Item 6. The carbon black paste (B) contains carbon black, water and a dispersant, and the carbon black concentration is in the range of 5 to 50% by mass in the carbon black paste (B). The aqueous filler composition according to any one of Items 1 to 4. Item 7. The aqueous filler composition according to any one of items 1 to 4, wherein the content of the carbon black paste (B) is in the range of 0.005% by mass to 1% by mass based on the total amount of the aqueous filler composition. Item 8. The aqueous filler composition according to any one of items 1 to 4, wherein the pigment (C) contains titanium white and calcium carbonate. Item 9. A painting method, wherein the aqueous filler composition according to any one of items 1 to 4 is applied to a building using a wool roller, dried, and then a topcoat paint is applied onto the formed base coat film. Item 10. A painting method, wherein the aqueous filler composition according to any one of items 1 to 4 is applied to a building using a wool roller so that the coating amount is in the range of 100 to 450 g / m 2 and after drying, a topcoat paint is applied onto the formed base coat film using a wool roller.

Advantages of the Invention

[0012] The aqueous filler composition of the present invention has good workability in wool roller painting, suppresses hiding unevenness, and provides a base coat film excellent in crack resistance. In addition, since the texture is also good, the finish of the topcoat paint applied thereon is also good.

Modes for Carrying Out the Invention

[0013] The aqueous filler composition of the present embodiment is a paint containing an aqueous resin (A), a carbon black paste (B), a pigment (C), a urethane associative thickener (D), and water. Each component will be described below.

[0014] Aqueous resin (A): In this embodiment, the aqueous resin (A) can be any conventionally known water-soluble or water-dispersible resin without particular limitation as long as it has the ability to form a coating film. When the aqueous resin (A) is water-dispersible, the resin portion can have a single-layer structure (homogeneous granular) or a multilayer structure such as a core-shell structure. In the case of a core-shell structure, the core and / or the shell may be crosslinked. Examples of the aqueous resin (A) include copolymers of polymerizable unsaturated monomers.

[0015] In this specification, the polymerizable unsaturated monomer refers to a monomer having a polymerizable unsaturated group. Examples of the polymerizable unsaturated group include (meth)acryloyl group, (meth)acrylamide group, vinyl group, vinyl ether group, allyl group, propenyl group, isopropenyl group, maleimide group, and the like.

[0016] In this specification, “(meth)acrylate” means acrylate or methacrylate, “(meth)acrylic acid” means acrylic acid or methacrylic acid, “(meth)acryloyl” means acryloyl or methacryloyl, and “(meth)acrylamide” means acrylamide or methacrylamide.

[0017] Examples of the polymerizable unsaturated monomer include (i) linear or branched alkyl group-containing (meth)acryloyl monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate; (ii) alicyclic alkyl group-containing (meth)acryloyl monomers such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate; (iii) aralkyl group-containing (meth)acryloyl monomers such as benzyl (meth)acrylate; (iv) (Meth)acryloyl monomers containing an alkoxyalkyl group such as 2-methoxyethyl (meth)acrylate and 2-ethoxyethyl (meth)acrylate; (v) Fluorine-containing (meth)acryloyl monomers such as hexafluoroisopropyl (meth)acrylate, perfluorooctylmethyl (meth)acrylate, and perfluorooctylethyl (meth)acrylate; (vi) Amino group-containing (meth)acryloyl monomers such as N,N-diethylaminoethyl (meth)acrylate; (vii) (Meth)acrylamide; (viii) Hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate, ε-caprolactone-modified products of the above hydroxyalkyl (meth)acrylates, and hydroxyl group-containing (meth)acryloyl monomers such as (meth)acrylates containing a polyoxyethylene chain with a hydroxyl group at the molecular terminal; (ix) Carboxyl group-containing (meth)acryloyl monomers such as (meth)acrylic acid and β-carboxyethyl acrylate; (x) Epoxy group-containing (meth)acryloyl monomers such as glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, and 3,4-epoxycyclohexylpropyl (meth)acrylate; (xi) Isocyanato group-containing (meth)acryloyl monomers such as isocyanatoethyl (meth)acrylate; (xii) Oxidation-curable group-containing (meth)acryloyl monomers such as dicyclopentenyl oxyethyl (meth)acrylate, dicyclopentenyl oxypropyl (meth)acrylate, and dicyclopentenyl (meth)acrylate; (xiii) Compounds having at least two (meth)acryloyl groups in one molecule, such as allyl (meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerol di(meth)acrylate, 1,1,1-trishydroxymethylethane di(meth)acrylate, 1,1,1-trishydroxymethylethane tri(meth)acrylate, 1,1,1-trishydroxymethylpropane tri(meth)acrylate; (xiv) Aromatic vinyl compounds such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, vinyl ethylbenzene, vinyl xylene, vinyl naphthalene, diphenylethylene; (xv) Carbonyl group-containing polymerizable unsaturated monomers such as acetoacetoxyethyl (meth)acrylate, diacetone (meth)acrylamide, (meth)acrolein, formylstyrene, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone, etc.), acetoacetoxyallyl ester; (xvi) Alkoxysilyl group-containing polymerizable unsaturated monomers such as γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane; (xvii) (Meth)acrylonitrile; (xviii) Vinyl ester compounds such as vinyl acetate, vinyl propionate; (xix) Allyl alcohol; (xx) Maleic acid, crotonic acid; (xxi) An allyl compound containing an epoxy group such as allyl glycidyl ether; (xxii) A polymerizable unsaturated monomer containing an isocyanato group such as m-isopropenyl-α,α-dimethylbenzyl isocyanate; and the like. One or more of (i) to (xxii) polymerizable unsaturated monomers can be used.

[0018] In this embodiment, from the viewpoint of the crack resistance of the base coating film, the glass transition temperature of the resin of the aqueous resin (A) is 30 ° C or lower. The glass transition temperature is preferably in the range of -25 to 20 ° C. In this specification, the glass transition temperature (Tg) of the resin is calculated as follows.

[0019] 1 / Tg(K)=W 1 / T 1 +W 2 / T 2 +···W n / T n Tg(°C)=Tg(K)-273 In the formula, W 1 , W 2 , ···W n are the mass fractions of the respective monomers, and T 1 , T 2 ···T n are the glass transition temperatures Tg(K) of the homopolymers of the respective polymerizable unsaturated monomers. The glass transition temperature of the homopolymer of each polymerizable unsaturated monomer is the value according to pages III-139 to 179 of Polymer Handbook (Second Edition, edited by J. Brandup and E. H. Immergut). When the glass transition temperature of the homopolymer is not clear, it is the static glass transition temperature when the homopolymer of the monomer is synthesized so that the weight average molecular weight is about 50,000. The static glass transition temperature is determined, for example, by using a differential scanning calorimeter "DSC-50Q type" (trade name, manufactured by Shimadzu Corporation), using a sample from which volatile components have been removed by vacuum suction, measuring the heat change in the range of -100 ° C to +100 ° C at a heating rate of 3 ° C / min, and observing the change point of the first baseline on the low temperature side.

[0020] The polymerization method of the above monomers is not particularly limited. For example, it can be carried out by (co)polymerizing the above monomers in the presence of a polymerization initiator and an emulsifier according to a general emulsion polymerization method.

[0021] The aqueous resin (A) may be a single resin or a combination of multiple resins as long as its glass transition temperature is 30°C or lower.

[0022] As an example where there are multiple types of aqueous resin (A), for example, (I) A copolymer (A1) of polymerizable unsaturated monomers that contain neither a carbonyl group-containing polymerizable unsaturated monomer nor an alkoxysilyl group-containing polymerizable unsaturated monomer, and a copolymer (A2) of polymerizable unsaturated monomers that contain a carbonyl group-containing polymerizable unsaturated monomer and an alkoxysilyl group-containing polymerizable unsaturated monomer. (II) A copolymer (A1) of polymerizable unsaturated monomers that contain neither a carbonyl group-containing polymerizable unsaturated monomer nor an alkoxysilyl group-containing polymerizable unsaturated monomer, and a copolymer (A3) of polymerizable unsaturated monomers that contain a carbonyl group-containing polymerizable unsaturated monomer and do not contain an alkoxysilyl group-containing polymerizable unsaturated monomer. Or (III) A copolymer (A3-1) of polymerizable unsaturated monomers that have a glass transition temperature of less than 0°C and contain a carbonyl group-containing polymerizable unsaturated monomer and do not contain an alkoxysilyl group-containing polymerizable unsaturated monomer, and a copolymer (A3-2) of polymerizable unsaturated monomers that have a glass transition temperature of 0°C or higher and contain a carbonyl group-containing polymerizable unsaturated monomer and do not contain an alkoxysilyl group-containing polymerizable unsaturated monomer. And so on. The copolymer (A1) of polymerizable unsaturated monomers containing neither a carbonyl group-containing polymerizable unsaturated monomer nor an alkoxysilyl group-containing polymerizable unsaturated monomer is at least one or more polymerizable unsaturated monomers selected from the group consisting of the above polymerizable unsaturated monomers (i) to (xxii), which do not contain a carbonyl group-containing polymerizable unsaturated monomer and an alkoxysilyl group-containing polymerizable unsaturated monomer as monomers. In a preferred embodiment, as the copolymer (A1) of polymerizable unsaturated monomers containing neither a carbonyl group-containing polymerizable unsaturated monomer nor an alkoxysilyl group-containing polymerizable unsaturated monomer, specifically, a polymer of monomers containing monomers (i), (viii) and (ix) and optionally containing at least one monomer selected from monomers (ii), (xiii) and (xi) is preferred.

[0023] The aqueous resin (A) is preferably contained in an amount of 5 to 95 parts by mass, more preferably 15 to 80 parts by mass, based on 100 parts by mass of the solid content of the aqueous filler composition.

[0024] In this specification, "solid content" is the residue obtained by removing volatile components such as water and organic solvents, and means non-volatile components such as resins, curing agents, and pigments. For example, the "solid content" is the residue after weighing 1 gram of a sample into a heat-resistant container such as an aluminum foil cup, spreading the sample on the bottom surface of the container, and drying it at 110°C for 1 hour.

[0025] Carbon black paste (B): The carbon black paste (B) contains carbon black and water, and is a paste in which carbon black is dispersed in water at a high concentration. The carbon black concentration of the carbon black paste (B), that is, the amount of carbon black contained in the carbon black paste (B), is preferably 5 to 50% by mass, particularly preferably 10 to 40% by mass. By using the carbon black paste (B) having a carbon black concentration within this range, the aqueous filler composition can be stably produced, and a base coating film having low hiding unevenness and a brightness that does not affect the finish of subsequent top coating can be formed without reducing crack resistance and the like.

[0026] The carbon black paste (B) may contain additives such as a dispersant, an antifoaming agent, a preservative, and a rheology control agent as necessary. Among these, the dispersant is also called a wetting agent, a resin for pigment dispersion, or a resin dispersant, and is commercially available. Examples of the dispersant include maleic acid-based resins such as acrylic resin-based, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl naphthalene-maleic acid copolymer, and vinyl acetate-maleic acid ester copolymer; urethane-based resins, polyvinyl alcohols; and compounds obtained by introducing at least one group selected from an acid group, an amino group, and a polyoxyalkylene group into resins such as vinyl acetate-crotonic acid copolymer. Particularly, it is preferably contained an acid group. The solid content of the dispersant in the solid content of the carbon black paste (B) is preferably in the range of 1 to 50% by mass, more preferably 2 to 40% by mass, from the viewpoint of obtaining a base coating film with less hiding unevenness and not affecting the finish of subsequent top coating. The content of the carbon black paste (B) is preferably 0.005 to 1% by mass, particularly preferably 0.03 to 0.5% by mass, in the aqueous filler composition (storage state).

[0027] Pigment (C): The aqueous filler composition of this embodiment contains a pigment (C). The pigment (C) is a pigment other than carbon black, such as titanium white, zinc oxide, alumina, graphite, black iron oxide, iron-manganese composite oxide, iron-copper-manganese composite oxide, iron-chromium-cobalt composite oxide, copper-chromium composite oxide, copper-manganese-chromium composite oxide, ferric oxide (valve handle), molybdate orange, permanent red, permanent carmine, anthraquinone red, perylene red, quinacridone red, yellow iron oxide, titanium yellow, fast yellow, benzimidazolone yellow, chrome green, cobalt green, phthalocyanine green, ultramarine blue, navy blue, cobalt blue, phthalocyanine blue, quinacridone violet, dioxazine violet, aluminum pigment, pearl pigment and other coloring pigments; extender pigments such as calcium carbonate, talc, barium sulfate, mica, clay, silica, aluminum hydroxide, and combinations thereof.

[0028] The pigment volume concentration of the aqueous filler composition of this embodiment is 30 to 65%, preferably in the range of 35 to 55%. In this specification, the "pigment volume concentration" is the volume ratio of the total pigment to the total solid content of the total resin and the total pigment in the paint. When the pigment volume concentration is 30 to 65%, the coating workability with a wool roller is good, it has a texture that does not affect the finish of the topcoat paint, and it forms an undercoat film with excellent crack resistance.

[0029] When calculating the volume of the pigment, the specific gravity of the pigment used as the basis is assumed to be the catalog value. If it is not clear, it is based on the "Paint Raw Material Handbook 9th Edition" (Japan Paint Industry Association). Also, the specific gravity of the resin solid content is approximated to 1. In this specification, when the pigment volume concentration is determined by calculation, and the "resin" that is the standard for the content of the urethane associative thickener (D) described later refers to, for example, the aqueous resin (A), aqueous resins other than the aqueous resin (A) blended as required, film-forming components such as crosslinking agents, and various additives such as urethane associative thickeners, dispersants, and defoamers are not applicable.

[0030] Further, the pigment (C) preferably contains titanium white and calcium carbonate in terms of enhancing the lightness of the coating film formed by the aqueous filler composition. Based on 100 parts by mass of the resin solid content contained in the aqueous filler composition, the total mass of titanium white and calcium carbonate is preferably in the range of 100 to 500 parts by mass, more preferably in the range of 150 to 400 parts by mass. Also, based on 100 parts by mass of the total mass of titanium white and calcium carbonate, the mass of titanium white is preferably 5 or more and less than 50 parts by mass, particularly preferably in the range of 10 to 20 parts by mass.

[0031] Urethane associative thickener (D): The aqueous filler composition of the present embodiment contains a urethane associative thickener (D). The urethane associative thickener is a urethane resin having a hydrophobic part (hydrophobic group) and a hydrophilic part (hydrophilic group). Examples of the hydrophobic group include hydrocarbon groups, and examples of the hydrophilic group include ether bonds. The urethane associative thickener (D) can be commercially obtained. Commercially available products include the Adekanol series (manufactured by ADEKA, trade name), the SN Thickeners series (manufactured by San Nopco), and the like.

[0032] In the present embodiment, the urethane associative thickener (D) can be used alone or in combination of two or more. The total content thereof is, from the viewpoints of the texture of the base coating film, hiding power, workability of wool roller coating, and hiding power of the coating film applied thereon, based on 100 parts by mass of the resin solid content contained in the aqueous filler composition, in the range of 0.1 to 2.5 parts by mass in terms of the active ingredient amount, preferably in the range of 0.2 to 1.5 parts by mass. Note that the active ingredient amount refers to the amount of the urethane associative thickener (D). When the urethane associative thickener (D) is a commercially available product, it refers to the amount of the urethane associative thickener (D) excluding other parts such as diluents.

[0033] In this embodiment, as the urethane associative thickener (D), a urethane associative thickener having a viscosity of a 5% aqueous solution within the range of 3000 mPa·sec or less, particularly within the range of 100 to 1000 mPa·sec, is particularly preferred. Specifically, a urethane associative thickener is preferred in which the viscosity when the urethane associative thickener is diluted with deionized water so that the active ingredient concentration becomes 5% by mass is within the range of 3000 mPa·sec or less, preferably within the range of 100 to 1000 mPa·sec. The active ingredient concentration shall be determined based on the active ingredient concentration described in the catalog value of the urethane associative thickener. When the active ingredient concentration of the urethane associative thickener is not clear, the solid content concentration of the urethane associative thickener shall be measured and used as the active ingredient concentration of the urethane associative thickener. The solid content concentration is calculated by weighing 1 gram of the sample in a heat-resistant container such as an aluminum foil cup, spreading the sample on the bottom surface of the container, drying it at 110°C for 1 hour, weighing the mass of the residue after drying, and obtaining the ratio of the mass of the component remaining after drying to the total mass of the sample before drying. Also, the viscosity of the 5% aqueous solution shall be measured under the conditions of a B-type viscometer, a rotation speed of 60 rpm, and 1 minute with the temperature of the sample set at 25°C. By including a urethane associative thickener (D) having such properties, the aqueous filler composition of this embodiment is excellent in coating workability with a wool roller, suppresses hiding unevenness even when applied to a substrate having an uneven pattern formed on the surface, and can form an undercoat film having a texture that does not affect the finish of the topcoat paint, which is preferable.

[0034] The reason why the above effects can be obtained depending on the type of the urethane associative thickener (D) is not clear, but it is considered that a urethane associative thickener having a viscosity of 3000 mPa·sec or less when diluted with deionized water has moderately hydrophobic properties, and the presence of this thickener in a specific amount of the coating liquid is considered to be able to control the coating liquid to an appropriate viscosity. As a result, during coating, the wool roller can be easily moved, and the coating workability is good. Further, when the surface of the object to be coated is not flat but has irregularities such as a pattern, when the paint is applied, the film thickness of the convex portion tends to be thin, but when a specific urethane associative thickener (D) is used, the coating liquid also easily remains on the convex portion, and it is presumed that a base coating film with less hiding unevenness can be easily obtained.

[0035] Water: The aqueous filler composition of the present embodiment contains water as a diluting medium. The water content may be different in the storage state and the coating state. In the storage state, the water content is 5 to 40 parts by mass, preferably 10 to 35 parts by mass, based on 100 parts by mass of the aqueous filler composition. In the coating state, the painter appropriately mixes water in consideration of the state of the surface to be coated, the temperature during coating, etc. The mixing amount is preferably about 0 to 20 parts by mass based on 100 parts by mass of the aqueous filler composition.

[0036] Other components: The aqueous filler composition of the present embodiment may contain, in addition to the above-described components, other aqueous resins other than the aqueous resin (A) having a glass transition temperature of 30°C or less, crosslinking agents, thickeners other than the urethane associative thickener (D), dispersants, film-forming aids, plasticizers, antifreezing agents, organic solvents, defoaming agents, antiseptics, antifungal agents, catalysts, and other components. These other components may be used alone or in combination of two or more.

[0037] When the other aqueous resin is included, the content of the other aqueous resin is less than 50 parts by mass, particularly less than 10 parts by mass, in terms of solid content mass in 100 parts by mass of the total solid content mass of the resins contained in the aqueous filler composition. The crosslinking agent can be selected according to the crosslinking functional groups possessed by the aqueous resin component. Specifically, examples thereof include hydrazide compounds, polyamine compounds, polyisocyanate compounds, and polycarboxylic acid compounds.

[0038] Examples of the other thickeners include polyacrylic acid-based thickeners, cellulose-based thickeners, inorganic thickeners, and the like.

[0039] Aqueous filler composition: The aqueous filler composition of the present embodiment has a lightness of the coating film formed by the aqueous filler composition within the range of 70 to 92. By having the lightness of the coating film within the range of 70 to 92, excellent hiding power can be achieved even with a small coating amount, hiding unevenness can be suppressed even on an uneven surface, and a primer coating film that has little influence on the topcoat paint applied thereon can be obtained. A lightness of 80 to 90 is more preferable.

[0040] In this specification, the lightness is represented by the CIE 1976 L * a * b * color system (conforming to JIS Z8781 4 (2013)), and can be measured using a commercially available colorimeter (for example, the color difference meter CR-400 manufactured by Konica Minolta Inc.) in accordance with JIS 5600 4-4 and JIS 5600 4-5. The test piece for lightness measurement is prepared by applying an acrylic plate mold around the black and white hiding paper defined in the JIS5600-4-1 1999 hiding power (for light-colored paints) test, pouring the sample so that the dry film thickness becomes 0.5 mm, leveling the surface with a spatula, drying at 23 °C for 4 days, and then removing the mold.

[0041] Coating method: The aqueous filler composition of the present embodiment is used for coating using a wool roller. A wool roller is made by implanting fiber hairs on a cylindrical member, and a wool-like fiber hair shape is known to be used. There are various wool rollers with different pile lengths, materials, sizes, and shapes, and they can be roughly classified into three types and are classified by the length from the surface of the cylindrical member to the tip of the hair (hereinafter referred to as the hair length). There are short-haired rollers with short pile about 4 to 5 mm long, medium-haired rollers with medium-length pile about 13 mm long, and long-haired rollers with pile length of 20 mm or more.

[0042] The aqueous filler composition of this embodiment can obtain a primer coating film with less hiding unevenness even with a small coating amount that results in a thin application, and has little influence on the finish of subsequent topcoat painting. Specific examples of the coating amount are, for example, 100 to 450 g / m 2 , particularly 120 to 400 g / m 2 . Drying after painting may be at room temperature or by heat drying, but room temperature drying is appropriate.

[0043] The coating amount is adopted as the value calculated from the consumption mass of the aqueous filler composition used in the coating process and the coating area.

[0044] Examples of the object for forming a primer coating film using the aqueous filler composition of this embodiment include the inner and outer wall surfaces, roofs, columns, ceilings, doors, etc. of buildings such as houses, office buildings, public facilities, and commercial facilities, and the outer wall of a building is particularly preferred. Examples of the material of the substrate include inorganic material substrates, wooden substrates, metal substrates, and plastic substrates, and those provided with an old coating film may also be used. The shape of the old coating film is not limited and may be planar or may have various three-dimensional pattern designs formed thereon. Examples of the pattern design include lysine, yuzu skin pattern, wavy pattern, crater pattern, stucco pattern, trowel finish, brush finish, etc. Also, before applying the aqueous filler composition, a sealer coating may be applied according to the type and condition of the object.

[0045] In this embodiment, after forming a base coating film using the aqueous filler composition, a topcoat paint is applied thereon. As the topcoat paint, topcoat paints known in the field of architectural paints can be used without limitation. Specifically, examples include paints containing, as a resin binder, an aqueous or solvent-based resin composed of resin types such as acrylic resin, acrylic-silicone resin, polyolefin resin, silicone resin, polyurethane resin, fluororesin, biodegradable resin, etc. It is preferable to use an aqueous paint containing an aqueous resin.

[0046] For the coating method of the above topcoat paint, without particular limitation, conventionally known methods such as roller, air spray, airless spray, lis gun, universal gun, brush, brush painting, etc. can be adopted. As the drying method, normal temperature drying is preferable, but heat drying can also be carried out as required. The coating amount of the topcoat paint is not particularly limited, but is in the range of 100~450 g / m 2 , preferably 120~400 g / m 2 . Since the base coating film formed by the aqueous filler composition of this embodiment is excellent in hiding power and crack resistance, even if the topcoat paint is thinly applied with a wool roller, it can give an aesthetic appearance to the object to be coated and protect it sufficiently.

Examples

[0047] Hereinafter, the present invention will be described in more detail with reference to production examples, examples and comparative examples, but the present invention is not limited thereto. "Parts" in each example represent parts by mass, and "%" represents mass%.

[0048] Production of aqueous resin Production Example 1 A reaction vessel equipped with a thermometer, a thermostat, a stirrer, and a dropping device was charged with 35 parts of deionized water and 1 part of Newcol 707SF (trade name, manufactured by Nippon Emulsifier Co., Ltd., an anionic surfactant having a polyoxyethylene chain, non-volatile content 30%). The mixture was stirred and mixed in a nitrogen stream and heated to 85°C. Next, 3% of a pre-emulsion formed by emulsifying the components of the following composition and 8 parts of a 2.5% aqueous ammonium persulfate solution were added into the reaction vessel and held at 85°C for 20 minutes. 40 parts of deionized water 25 parts of styrene 70 parts of 2-ethylhexyl acrylate 1 part of 2-hydroxyethyl acrylate 4 parts of methacrylic acid 8 parts of Newcol 707SF Thereafter, the remaining pre-emulsion and 8 parts of a 2.5% aqueous ammonium persulfate solution were dropped into the reaction vessel over 4 hours, and aging was carried out for 2 hours after the dropping was completed. Thereafter, it was cooled to 30°C and adjusted to a solid content of 50% and a pH of 8.0 using aqueous ammonia and deionized water. Next, it was discharged while filtering through a 200-mesh nylon cloth to obtain an aqueous resin (A1) having a glass transition temperature of -22°C.

[0049] Production Examples 2 to 5 In the above Production Example 1, synthesis was carried out in the same manner as in Production Example 1 except that the monomer composition was changed to the formulation shown in Table 1 below to obtain aqueous resins (A2), (A3-1), and (A3-2) and aqueous resin (X).

[0050]

Table 1

[0051] Production of Carbon Black Paste Production Examples 6 to 8 Carbon black pastes (P-1) to (P-3) were produced with the formulations shown in Table 2 below.

[0052]

Table 2

[0053] (Note 1) FLOREN G700AMP: Product name, manufactured by BYK Kyoei Co., Ltd., an aqueous wetting dispersant, a water-diluted product of the 2-methyl-2-amino-1-propanol salt of a carboxyl group-containing polymer, solid content 45% (Note 2) SN Defoamer 395: Product name, manufactured by San Nopco Ltd., a defoaming agent (Note 3) NATROSOL 250HBR: Product name, manufactured by Ashland, hydroxyethyl cellulose.

[0054] Manufacture of Aqueous Filler Composition Examples 1 to 18 and Comparative Examples 1 to 8 Each component shown in Table 3 was charged into a stainless steel container while stirring, and stirring was continued with a homodisper from PRIMIX Co., Ltd. for 15 minutes until uniform to produce aqueous filler compositions (X-1) to (X-26). In Table 3, the blending amounts of the materials containing volatile components are shown as the masses including the volatile components.

[0055]

Table 3

[0056] (Note 4) DISPER BYK-190: Product name, manufactured by BYK Co., Ltd., an aqueous wetting dispersant, an aqueous solution of a polyether-modified styrene-maleic anhydride copolymer, solid content 40% (Note 5) SN Thickener 615: Product name, manufactured by San Nopco Ltd., a polyacrylic acid-based thickener, active ingredient 10% (Note 6) SN Thickener 625N: Product name, manufactured by San Nopco Ltd., a urethane associative thickener, active ingredient 15% (Note 7) Adekanol UH-420: Product name, manufactured by ADEKA Corporation, a urethane associative thickener, active ingredient 30% (Note 8) PRIMAL RM12W: Product name, manufactured by The Dow Chemical Company, a urethane associative thickener, active ingredient 19% (Note 9) Adekanol UH-530: Manufactured by ADEKA Corporation, a urethane associative thickener, active ingredient 30% (Note 10) SN Thickener 612NC: Product name, manufactured by Sanshin Chemical Industry Co., Ltd., urethane associative thickener, active ingredient 45%, (Note 11) SN Thickener 665T: Product name, manufactured by Sanshin Chemical Industry Co., Ltd., urethane associative thickener, active ingredient 10% (Note 12) Viscosity of urethane associative thickener: Each urethane associative thickener was diluted with deionized water so that the active ingredient concentration was 5% by mass, and a sample with a temperature of 25°C was measured with a B-type viscometer under the conditions of a rotation speed of 60 rpm for 1 minute.

[0057] <Evaluation Test> The aqueous filler compositions obtained in the examples and comparative examples were subjected to the following evaluations. The results are shown together in Table 3. The lightness was measured according to the method described in the specification.

[0058] On a slate board with a size of about 1 square meter, "Ares Holder GII" (product name, Kansai Paint, aqueous micro-elastic primer) was applied in a wavy pattern using a porous roller so that the coating amount was 0.8 kg / m 2 Then, "Ares Aqua Gloss" (product name, Kansai Paint, acrylic aqueous topcoat) adjusted to a blue-gray color was applied with a wool roller, and the coated board obtained by drying at 23°C for 14 days was regarded as an old coating film and used as a substrate. On this wavy coating surface, each aqueous filler composition obtained in the examples and comparative examples was thinly applied using a wool roller (wool roller manufactured by PIA Co., Ltd., pile length 25 mm) so that the coating amount was 220 g / m 2 Then, the coating workability (ease of moving the wool roller in (1) below, spattering property of the paint in (2) below) was evaluated. Then, it was dried at 23°C for 7 days to obtain a coated board for evaluation. This coated board was used for the evaluations in (3) to (5) below.

[0059] (1) Ease of moving the wool roller: The ease of moving when the aqueous filler compositions of the examples and comparative examples were applied with a wool roller was evaluated according to the following criteria. ◎: The roller is light and very easy to move 〇: The roller may feel slightly heavy depending on the location, but it is easy to move. △: The roller feels slightly heavy and is slightly difficult to move. ×: The roller feels very heavy and is very difficult to move.

[0060] (2) Paint splashing property: When each aqueous filler composition of the examples and comparative examples was applied with a wool roller, the paint splashing condition was evaluated according to the following criteria. ◎: Almost no splashing 〇: Slightly splashing but at a practical level △: Clearly splashing ×: Significantly splashing.

[0061] (3) Concealment of the aqueous filler on the pattern coating film: The coated board prepared in the evaluation of the above coating workability was visually observed from a distance of 50 cm, and the state where the blue-gray color, which is the base color, could be seen through was evaluated in the following 4 levels. ◎: The transparency of the base color is not noticeable. ○: The transparency of the base color is slightly recognized at the convex part, but it is not noticeable when observed from 1 m away. △: The transparency of the base color is recognized overall and is noticeable even when observed from 1 m away. ×: The transparency of the base color is significantly recognized overall and is quite noticeable even when observed from 1 m away.

[0062] (4) Texture of the aqueous filler on the pattern coating film The coated board prepared in the evaluation of the above coating workability was visually observed from a distance of 50 cm, and the overall texture of the coating film surface formed from the aqueous filler was evaluated in the following 4 levels. ◎: Almost no roller marks (filamentous marks formed after the roller passes), and the entire painted surface has a smooth and uniform texture. ○: Slightly roller marks (filamentous marks formed after the roller passes) are recognized, but when observed from 1 m away, the entire painted surface has a uniform texture. △: Roller marks (filamentous marks formed after the roller passes) are observable across the entire painted surface, and the texture feels slightly poor even when viewed from a distance of 1 m. ×: Roller marks (filamentous marks formed after the roller passes) are clearly observable across the entire painted surface, and the texture feels poor even when viewed from a distance of 1 m.

[0063] (5) Crack resistance The painted panel created in the evaluation of the above painting workability was cut into a size of 20 cm in width × 30 cm in length, and the back and side surfaces were sealed and painted with "Cera M Retan Clear" (manufactured by Kansai Paint Co., Ltd., a weak solvent-based two-component urethane clear paint). After drying for 48 hours, a total of 10 cycles of a thermal cycling test were carried out with water immersion (23 °C) for 18 hours → 3 hours in air at -20 °C → 3 hours in air at 50 °C as one cycle, and then the cracks on the surface of the paint film were visually confirmed. ◎: No cracks occurred 〇: Cracks occurred in an area of less than 5% △: Cracks were observed in an area of 5% or more and less than 50%, ×: Cracks were observed in an area of 50% or more.

[0064] (6) Concealment of topcoat: On a slate board with an area of approximately 1 square meter, "Ares Holder GII" (product name, Kansai Paint, water-based micro-elastic base conditioner) was applied in a wavy pattern using a porous roller at a rate of 0.8 kg / m 2 Then, a paint plate obtained by painting "Ares Aqua Gloss" (product name, Kansai Paint, acrylic-based water-based topcoat paint) adjusted to a blue-gray color with a wool roller and drying it at 23 °C for 14 days was regarded as an old paint film and used as a base material. On this wavy painted surface, each aqueous filler composition obtained in the examples and comparative examples was applied using a wool roller (wool roller made by PIA Co., Ltd., "Melon", 25 mm pile length) at an application rate of 180 g / m 2 After painting and drying at 23 °C for 7 days, "Cosmo Silicon White" (manufactured by Kansai Paint Co., Ltd., water-based acrylic silicon topcoat paint) was applied on it at an application rate of 120 g / m 2The paint was applied using a wool roller ("Peach", wool roller made by Otsuka Brush Manufacturing, bristle length 20 mm) so that the paint was applied as shown in the figure, and the paint was dried at a temperature of 23°C for 7 days to obtain a test painted board for evaluating the suitability for topcoating. The painted board was visually observed from a distance of 50 cm, and the state in which the color of the aqueous filler composition, which is the base color, was visible through the board was evaluated into the following 4 stages. ◎: The color of the water-based filler composition is not noticeable. ○: The color of the aqueous filler composition is visible in the convex parts, but is not noticeable when viewed from a distance of 1 m. △: The color of the aqueous filler composition is generally visible. ×: The color of the aqueous filler composition is significantly visible overall.

Claims

1. An aqueous filler composition for forming a base coat using a wool roller prior to painting a top coat, comprising: An aqueous filler composition comprising an aqueous resin (A) having a glass transition temperature of 30° C. or lower, a carbon black paste (B), a pigment (C), a urethane association type thickener (D), and water, the pigment volume concentration being within the range of 30 to 65%, the content of the urethane association type thickener (D) being 0.1 to 2.5 parts by mass in terms of the amount of active ingredient per 100 parts by mass of resin solids contained in the aqueous filler composition, and the brightness of a coating film formed from the aqueous filler composition being within the range of 70 to 92.

2. An aqueous resin (A) having a glass transition temperature of 30° C. or less, A copolymer (A1) of polymerizable unsaturated monomers that does not contain any of a carbonyl group-containing polymerizable unsaturated monomer and an alkoxysilyl group-containing polymerizable unsaturated monomer, and Copolymer (A2) of polymerizable unsaturated monomers including carbonyl group-containing polymerizable unsaturated monomers and alkoxysilyl group-containing polymerizable unsaturated monomers The aqueous filler composition of claim 1 , comprising:

3. An aqueous resin (A) having a glass transition temperature of 30° C. or less, A copolymer (A1) of polymerizable unsaturated monomers that does not contain any of a carbonyl group-containing polymerizable unsaturated monomer and an alkoxysilyl group-containing polymerizable unsaturated monomer, and Copolymer (A3) of polymerizable unsaturated monomers containing a carbonyl group-containing polymerizable unsaturated monomer and not containing an alkoxysilyl group-containing polymerizable unsaturated monomer The aqueous filler composition of claim 1 , comprising:

4. An aqueous resin (A) having a glass transition temperature of 30° C. or less, A copolymer (A3-1) of polymerizable unsaturated monomers having a glass transition temperature of less than 0° C., containing a carbonyl group-containing polymerizable unsaturated monomer and not containing an alkoxysilyl group-containing polymerizable unsaturated monomer; and A copolymer (A3-2) of polymerizable unsaturated monomers having a glass transition temperature of 0° C. or higher and containing a carbonyl group-containing polymerizable unsaturated monomer and not containing an alkoxysilyl group-containing polymerizable unsaturated monomer. The aqueous filler composition of claim 1 , comprising:

5. The aqueous filler composition according to any one of claims 1 to 4, wherein the carbon black paste (B) contains carbon black and water, and a carbon black concentration in the carbon black paste (B) is within a range of 5 to 50 mass%.

6. The aqueous filler composition according to any one of claims 1 to 4, wherein the carbon black paste (B) contains carbon black, water, and a dispersant, and a carbon black concentration in the carbon black paste (B) is within a range of 5 to 50 mass%.

7. The aqueous filler composition according to any one of claims 1 to 4, wherein the content of the carbon black paste (B) is within the range of 0.005% by mass to 1% by mass based on the total amount of the aqueous filler composition.

8. The aqueous filler composition according to any one of claims 1 to 4, wherein the pigment (C) comprises titanium dioxide and calcium carbonate.

9. A coating method comprising applying the aqueous filler composition according to any one of claims 1 to 4 to a building using a wool roller, drying the composition, and then applying a topcoat paint onto the resulting base coating film.

10. The aqueous filler composition according to any one of claims 1 to 4 is applied to a building using a wool roller in an amount of 100 to 450 g / m ２ This is a coating method in which the paint is applied within the range, dried, and then a topcoat is applied to the formed base coat using a wool roller.

Images