Water-based covering material

Abstract

To provide an aqueous coating material that can form a matte coating layer and has improved performances including the efficiency of coating work and its finish.SOLUTION: An aqueous coating material contains synthetic resin emulsion and pigments. The aqueous coating material has a volumetric pigment density of 30-70%. The pigments include a coloring pigment (b), an extender pigment (c) with an oil absorption of less than 50 ml / 100 g, and an extender pigment (d) with an oil absorption of 50 ml / 100 g or more. The weight ratio of the coloring pigment (b) to the extender pigment (c) is 100: (20-500), and the weight ratio of the coloring pigment (b) to the extender pigment (d) is 100: (5-100).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a novel water-based coating material. [Background technology]

[0002] Conventionally, various coating materials have been applied to buildings and civil engineering structures for the purpose of beautifying and protecting the surface. Coating materials with various gloss grades are available for these paint finishes. Among these, coating materials capable of forming a matte coating film can provide a calm and unique texture, and water-based coating materials specified in JIS K5663 "Synthetic resin emulsion paint" are common as such coating materials.

[0003] Regarding such an aqueous coating material, Patent Document 1 describes an aqueous coating material that contains an aqueous resin, a color pigment, a specific extender pigment, etc. Among these, the color pigment is a component for imparting color and hiding power to the coating film. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-40349 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the above-mentioned water-based coating material is applied to a surface to be coated with a roller or the like, the roller may slip or fine irregularities may occur on the coated surface, resulting in insufficient hiding power of the coating and adversely affecting the finished quality.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to improve the performance, such as coating workability and finish, of an aqueous coating material capable of forming a matte coating film. [Means for solving the problem]

[0007] As a result of extensive research into achieving the above object, the inventors of the present invention came up with the idea of ​​an aqueous coating material having a specific pigment composition, and completed the present invention.

[0008] That is, the present invention has the following features. 1. An aqueous coating material comprising a synthetic resin emulsion and a pigment, The aqueous coating material has a pigment volume concentration of 30 to 70%, The pigments include a color pigment (b), an extender pigment (c) having an oil absorption of less than 50 ml / 100 g, and an extender pigment (d) having an oil absorption of 50 ml / 100 g or more, The weight ratio of the color pigment (b) to the extender pigment (c) is 100:(20 to 500); The weight ratio of the color pigment (b) to the extender pigment (d) is 100:(5 to 45 ) The aqueous coating material is characterized by: 2. The aqueous coating material according to 1., wherein the proportion of the body pigment (d) is 4 to 40% by weight in the total amount of the color pigment (b), the body pigment (c) and the body pigment (d). 3. An aqueous coating material according to 1. or 2., characterized in that the viscosity measured with a dynamic viscoelasticity measuring device is 0.5 Pa·s or less at a shear rate of 1000 s-1, and is 5 to 60 Pa·s at a shear rate of 0.1 s-1. 4. A method for applying an aqueous coating material, comprising applying the aqueous coating material according to any one of 1. to 3. with a roller and / or a brush. 5. The amount of water-based coating material applied is 0.1 to 0.8 kg / m 2 4. The method for applying the aqueous coating material according to claim 4, Effect of the Invention

[0009] The aqueous coating material of the present invention can exhibit excellent performance in terms of coating workability, finishing properties, etc. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described.

[0011] The aqueous coating material of the present invention contains a synthetic resin emulsion and a pigment.

[0012] Among these, synthetic resin emulsion (a) (hereinafter also referred to as "component (a)") is a component that plays a role of fixing pigments and the like. Examples of the type of resin in component (a) include ethylene resin, vinyl acetate resin, polyester resin, alkyd resin, epoxy resin, acrylic resin, urethane resin, acrylic silicone resin, fluororesin, and the like, as well as composites thereof. These can be used alone or in combination of two or more. Furthermore, these binders may be either those that have crosslinking reactivity or those that do not have crosslinking reactivity.

[0013] When a crosslinkable component (a) is used, the water resistance, durability, weather resistance, etc. of the coating can be improved. Such crosslinkability can be imparted by combining reactive functional groups such as a carboxyl group and a carbodiimide group, a carboxyl group and an epoxy group, a carboxyl group and an aziridine group, a carboxyl group and an oxazoline group, a hydroxyl group and an isocyanate group, a carbonyl group and a hydrazino group, an epoxy group and a hydrazino group, an epoxy group and an amino group, or an alkoxysilyl group and another alkoxysilyl group. These combinations can be used alone or in combination of two or more.

[0014] The glass transition temperature (hereinafter also referred to as "Tg") of component (a) is preferably -50 to 80°C, more preferably -40 to 40°C. When the Tg of component (a) is equal to or higher than the above lower limit, it is advantageous in terms of stain resistance, blister resistance, etc. When the Tg of component (a) is equal to or lower than the above upper limit, it is advantageous in terms of film-forming property, crack resistance, etc. Note that Tg referred to here is a value calculated by Fox's formula from the types of monomers constituting component (a) and their constituent ratios. In the present invention, "a to b" is synonymous with "a or more and b or less".

[0015] The average particle size of component (a) is not particularly limited, but is preferably 300 nm or less (more preferably 20 to 280 nm, and even more preferably 30 to 260 nm). If the average particle size is within such a range, it is suitable in terms of improving performance such as durability, water impermeability resistance, and efflorescence resistance. The average particle size referred to here is a value measured by dynamic light scattering.

[0016] The aqueous coating material of the present invention contains the above component (a) and a pigment as essential components, and has a pigment volume concentration of 30 to 70% (preferably 35 to 65%, more preferably 40 to 60%). Having a pigment volume concentration equal to or higher than the above lower limit is advantageous in terms of gloss reduction, coating strength, etc. Having a pigment volume concentration equal to or lower than the above upper limit is advantageous in terms of durability, water permeability resistance, cracking resistance, etc., and can also prevent the pigment from detaching (color transfer) from the coating. The pigment volume concentration in the present invention is the volume percentage of the pigment contained in the dry coating, and is a value calculated from the weight parts and specific gravity of the resin component and pigment constituting the aqueous coating material. The specific gravity of the resin component is 1.

[0017] In the present invention, the pigments include a color pigment (b), an extender pigment (c) having an oil absorption of less than 50 ml / 100 g, and an extender pigment (d) having an oil absorption of 50 ml / 100 g or more.

[0018] Among these, the color pigment (b) (hereinafter also referred to as "component (b)") is a component that imparts color, hiding properties, etc. to the coating. Examples of component (b) include titanium oxide, zinc oxide, alumina, carbon black, 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 (red oxide), 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, Prussian blue, cobalt blue, phthalocyanine blue, quinacridone violet, dioxazine violet, aluminum pigments, and pearl pigments. These can be used alone or in combination of two or more. By using one or more of these components (b) as appropriate, the color tone of the coating can be adjusted.

[0019] The oil absorption of component (b) is not particularly limited, but is preferably 150 ml / 100 g or less, more preferably 5 to 120 ml / 100 g, and even more preferably 10 to 95 ml / 100 g. The average particle size of component (b) is preferably 10 μm or less, more preferably 1 μm or less, and even more preferably 0.01 to 0.9 μm. The average particle size of the pigment is the median diameter measured by a laser diffraction particle size distribution measuring device.

[0020] In the present invention, the pigment further includes an extender pigment (c) (hereinafter also referred to as "component (c)") having an oil absorption of less than 50 ml / 100 g, and an extender pigment (d) (hereinafter also referred to as "component (d)") having an oil absorption of 50 ml / 100 g or more. The weight ratio of component (b) to component (c) {component (b):component (c)} is 100:(20-500), and the weight ratio of component (b) to component (d) {component (b):component (d)} is 100:(5-100).

[0021] In the present invention, by using the color pigment (b) and the two types of extender pigments (c) and (d) in a specific ratio, excellent performance can be achieved in terms of coating workability and finish, and a flat matte coating with sufficiently reduced gloss can be obtained. In particular, the present invention can prevent the roller or the like from slipping when coating with a roller or the like, or prevent fine irregularities from occurring on the coating surface. This enhances the hiding power of the coating, and provides an excellent finish.

[0022] The oil absorption (ml / 100g) is a value determined by the method specified in JIS K5101-13-2:2004, and is expressed in ml of boiled linseed oil per 100g of powder or grain.

[0023] As the component (c), the material is not particularly limited as long as it satisfies the above physical properties, and various extender pigments can be used. Examples of the component (c) include calcium carbonate, kaolin, clay, china clay, talc, baryte powder, barium sulfate, barium carbonate, magnesium carbonate, silica powder, and aluminum hydroxide. These can be used alone or in combination of two or more. The oil absorption of the component (c) is less than 50 ml / 100 g, preferably 3 to 45 ml / 100 g, more preferably 5 to 40 ml / 100 g, and even more preferably 8 to 35 ml / 100 g.

[0024] As for the component (d), as long as it satisfies the above physical properties, the material is not particularly limited and various extender pigments can be used. Examples of the component (d) include silica gel, zeolite, sodium sulfate, aluminum silicate, allophane, calcined clay, calcined kaolin, diatomaceous earth, siliceous shale, vermiculite, perlite, Oya stone powder, activated clay, charcoal, activated carbon, wood powder, and shirasu balloons. These can be used alone or in combination. The oil absorption of the component (d) is preferably 55 to 400 ml / 100 g, more preferably 60 to 300 ml / 100 g. In the present invention, it is preferable that the component (d) contains at least one extender pigment with an oil absorption of 80 to 400 ml / 100 g, and more preferably contains at least one extender pigment with an oil absorption of 100 to 300 ml / 100 g. According to such an embodiment, the effect of reducing gloss and the effect of suppressing uneven gloss can be further enhanced, and a consistent matte finish can be obtained even when the condition of the coated surface is different.

[0025] The average particle size of components (c) and (d) is preferably 0.5 to 50 μm, more preferably 0.8 to 40 μm, and further preferably 1 to 30 μm. Components (c) and (d) having such average particle size are suitable in terms of reducing gloss and flattening the coating film.

[0026] In the present invention, the weight ratio of the (b) component to the (c) component is 100: (20-500), preferably 100: (40-400), more preferably 100: (50-300), and even more preferably 100: (60-250). The weight ratio of the (b) component to the (d) component is 100: (5-100), preferably 100: (8-80), more preferably 100: (10-60), and even more preferably 100: (15-45). This provides excellent coating workability, excellent color development, hiding power, gloss reduction, and gloss unevenness suppression, and sufficient finish. Furthermore, excellent performance is obtained in crack resistance, water permeability resistance, and the like. If the weight ratio of the (c) component is below the above lower limit, it is disadvantageous in terms of gloss reduction, etc. If the weight ratio of component (c) exceeds the upper limit, it will be disadvantageous in terms of crack resistance, water permeability, etc., and the proportion of component (b) will become relatively small, which will be disadvantageous in terms of color development, hiding power, etc. If the weight ratio of component (d) is below the lower limit, it will be disadvantageous in terms of reduced gloss, paintability, finish, etc., and uneven gloss, etc. will be easily generated. If the weight ratio of component (d) exceeds the upper limit, it will be disadvantageous in terms of paintability, finish, crack resistance, water permeability, etc.

[0027] In the present invention, it is preferable that the ratio of the body pigment (d) in the total amount of the color pigment (b), the body pigment (c) and the body pigment (d) is set to 4 to 40% by weight (more preferably 5 to 30% by weight, and further preferably 6 to 25% by weight). Such an embodiment is more preferable in terms of the manifestation of the above-mentioned effects.

[0028] In the present invention, in addition to the above-mentioned components, various additives can be mixed. Examples of such additives include pigment dispersants, emulsifiers, viscosity regulators, film-forming assistants, leveling agents, coupling agents, wetting agents, plasticizers, antifreeze agents, pH adjusters, preservatives, antifungal agents, anti-algae agents, antibacterial agents, defoamers, adsorbents, deodorizers, ultraviolet absorbers, light stabilizers, antioxidants, catalysts, crosslinking agents, solvents, and water. It is preferable not to mix powders with large particle sizes (for example, fillers with an average particle size of 80 μm or more) because they are disadvantageous in flattening the coating.

[0029] Among the above additives, examples of the viscosity modifier include associative viscosity modifiers, alkali swelling type viscosity modifiers, water-soluble polymer type viscosity modifiers, inorganic viscosity modifiers, etc. These can be used alone or in combination of two or more.

[0030] Specifically, examples of associative viscosity modifiers include hydrophobically modified ethoxylated urethane (HEUR), hydrophobically modified alkali-swellable / soluble emulsion (HASE), hydrophobically modified hydroxyethyl cellulose (HMHEC), hydrophobized polyacrylamide, etc. Examples of alkali-swellable viscosity modifiers (ASE) include alkali-swellable acrylic emulsion, etc. Examples of water-soluble polymer-type viscosity regulators include cellulose, cellulose derivatives (carboxymethyl cellulose, carboxyethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, oxidized cellulose, etc.), polyvinyl alcohol, alginic acid, sodium alginate, polyvinylpyrrolidone, biogum, starch, starch derivatives (carboxyalkyl starch, alkyl starch, hydroxyalkyl starch, oxidized starch, etc.), xanthan gum, guar gum, locust bean gum, carrageenan, gum arabic, tragacanth gum, gelatin, agar, casein, psyllium sheet gum, tamarind sheet gum, etc. Examples of inorganic viscosity regulators include bentonite, smectite, silica, montmorillonite, etc. These can be used alone or in combination of two or more. In the present invention, it is preferable that the viscosity regulator contains at least an associative viscosity regulator, and it is more preferable that the viscosity regulator contains at least a hydrophobically modified ethoxylated urethane (HEUR).

[0031] In the present invention, two or more types of viscosity modifiers can be included. Such an embodiment is more suitable in terms of viscosity adjustment of the aqueous coating material. Examples of such combinations of viscosity modifiers include associative viscosity modifiers and alkali swelling type viscosity modifiers, associative viscosity modifiers and water-soluble polymer type viscosity modifiers, associative viscosity modifiers and inorganic viscosity modifiers, etc. In addition, two or more types of associative viscosity modifiers can be combined, and examples of such combinations include hydrophobically modified ethoxylated urethane (HEUR) and hydrophobically modified alkali swelling / soluble emulsion (HASE), hydrophobically modified ethoxylated urethane (HEUR) and hydrophobically modified hydroxyethyl cellulose (HMHEC), hydrophobically modified ethoxylated urethane (HEUR) and hydrophobically modified polyacrylamide, hydrophobically modified ethoxylated urethane (HEUR) and each other, etc.

[0032] The ratio of the viscosity modifier is preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight, calculated as solid content, relative to 100 parts by weight of the solid content of the component (A). If the ratio of the viscosity modifier is within this range, it is more suitable in terms of adjusting the viscosity of the aqueous coating material.

[0033] The aqueous coating material of the present invention can be produced by uniformly mixing the above-mentioned components (a), (b), (c), and (d), and various additives as required, in a conventional manner.

[0034] The aqueous coating material of the present invention is an aqueous material containing water as a medium. The medium may contain a water-soluble solvent in addition to water, if necessary. Examples of the water-soluble solvent include alcohols, glycols, and glycol ethers.

[0035] The aqueous coating material of the present invention has a shear rate of 1000 s measured by a dynamic viscoelasticity measuring device. -1 The viscosity at a shear rate of 0.1 s is 0.5 Pa s or less (preferably 0.05 to 0.4 Pa s). -1It is preferable that the viscosity at the time of application is 5 to 60 Pa·s (more preferably 8 to 55 Pa·s, and even more preferably 10 to 50 Pa·s). When the aqueous coating material of the present invention satisfies such a viscosity condition, it is possible to obtain even more excellent effects in terms of paint workability, color development, hiding power, finish, and the like. An aqueous coating material that satisfies such a viscosity condition can be obtained by making the pigment composition in the above-mentioned form and fine-tuning by mixing one or more selected from a viscosity adjuster, a solvent, water, and the like as necessary. In the present invention, it is preferable that the aqueous coating material at the time of application (the diluted aqueous coating material in the case of dilution) satisfies the above viscosity condition. In addition, as a dynamic viscoelasticity measuring device, MCR302ST (manufactured by Anton Paar Japan Co., Ltd.) and the like can be used, and the measurement temperature is 23°C.

[0036] The aqueous coating material of the present invention has a heating residue of preferably 40 to 90% by weight, more preferably 50 to 80% by weight. The heating residue within the above range can improve the coating workability, color development, hiding power, finish, etc., and is also suitable in terms of viscosity adjustment.

[0037] The aqueous coating material of the present invention can be applied to, for example, surface finishing of the coated surface of buildings, civil engineering structures, etc. Examples of substrates constituting the coated surface include concrete, mortar, porcelain tile, fiber-mixed cement board, cement calcium silicate board, slag cement perlite board, cement board, ALC board, siding board, gypsum board, plywood, extrusion molding board, steel board, plastic board, etc. The surfaces of these substrates may be subjected to some surface treatment (for example, treatment with putty, sealer, surfacer, filler, etc.), may already have a coating film formed thereon, or may have wallpaper, etc., attached thereto.

[0038] When applying the aqueous coating material of the present invention, various application tools such as sprays, rollers, brushes, etc. can be used. In particular, advantageous effects can be achieved when using rollers and / or brushes. Among these, for example, short-haired, medium-haired, or long-haired fibrous rollers (wool rollers, etc.) can be used as rollers.

[0039] When applying, it is possible to dilute the coating material with water. The amount of water to be mixed may be appropriately determined taking into consideration the type of coating equipment, the condition of the surface to be coated, the temperature during application, etc., but is preferably about 0 to 20% by weight based on the total weight of the aqueous coating material.

[0040] The amount of the aqueous coating material applied is preferably 0.1 to 0.8 kg / m 2 , more preferably 0.12 to 0.6 kg / m 2 , and more preferably 0.15 to 0.4 kg / m 2 By applying the water-based coating material in such an amount, it is possible to form a matte, flat, thin coating film with excellent color development, hiding power, etc.

[0041] After application of the aqueous coating material, drying is preferably performed at room temperature (5 to 40°C), but heating is also possible if necessary. The drying time is preferably about 0.5 to 4 hours at room temperature. The number of coats may be one or two or more (preferably one or two). When the number of coats is two or more, it is desirable that the total amount of coats is within the above range.

[0042] In the present invention, a coating with reduced gloss, that is, a matte coating, can be formed. The term "matte" as used herein includes not only what is generally called matte, but also what is called 30% gloss, 50% gloss, etc. Specifically, the degree of matte can be defined by the specular gloss. The specular gloss of the aqueous coating material of the present invention is preferably 40 or less, more preferably 20 or less, and even more preferably 0.1 to 10. The specular gloss is a value obtained by applying the coating material to one side of a glass plate using a film applicator with a gap of 150 μm, placing the coated surface horizontally, and drying for 48 hours under standard conditions (air temperature 23° C., relative humidity 50%), and measuring the specular gloss (measurement angle 60 degrees). EXAMPLES

[0043] The following examples will clarify the features of the present invention.

[0044] ○Production of water-based coating materials Each aqueous coating material was manufactured by mixing the raw materials in the amounts shown in Table 1 by a conventional method. The raw materials used were as follows. The properties of each aqueous coating material are shown in Table 1. Synthetic resin emulsion 1: Acrylic resin emulsion (glass transition temperature -18°C, solid content 50% by weight, average particle size 150 nm) Color pigment 1: Titanium oxide (average particle size 0.3 μm, specific gravity 4.2, oil absorption 22 ml / 100 g) Extender pigment 1: Heavy calcium carbonate (average particle size 8 μm, specific gravity 2.7, oil absorption 24 ml / 100 g) · Extender pigment 2: Aluminum silicate (average particle size 4μm, specific gravity 2.6, oil absorption 70ml / 100g) · Extender pigment 3: Diatomaceous earth (average particle size 10 μm, specific gravity 2.3, oil absorption 180 ml / 100 g) Surfactant 1: Anionic surfactant Surfactant 2: Nonionic surfactant Viscosity modifier 1: Associative viscosity modifier (hydrophobically modified polyoxyethylene urethane resin, solid content 30% by weight) Viscosity modifier 2: Water-soluble polymer-type viscosity modifier (hydroxyethyl cellulose aqueous solution, solid content 3% by weight) Defoamer: Silicone-based defoamer

[0045] Test 1 Each water-based coating material was applied to one side of a glass plate using a film applicator with a gap of 150 μm, and the coated surface was placed horizontally and dried for 48 hours under standard conditions (air temperature 23°C, relative humidity 50%), after which the specular gloss (measurement angle 60 degrees) was measured. The evaluation criteria were: specular gloss of 5 or less was given an "A", specular gloss of more than 5 to 10 was given a "B", and specular gloss of more than 10 was given a "C".

[0046] Test 2 A gypsum board with a black undercoat coating applied only to the right half of the board was coated with a 0.12 kg / m2 coating using a fiber roller. 2Each water-based coating material was applied and the painting workability was evaluated. In Test 2, the slipperiness during roller painting was evaluated on a three-level scale (A>B>C: excellent) with "A" being the one where no slipperiness was observed and "C" being the one where slipperiness was observed. The painting was performed under standard conditions.

[0047] Test 3 After drying the test panels in test 2 for 48 hours under standard conditions, the appearance of the test panels was observed to evaluate the finish of the coating. In test 3, the coating was evaluated on a three-level scale (A>B>C: poor), with "A" being a high concealing property with little visible unevenness and "C" being a low concealing property with visible unevenness.

[0048] Test 4 The test panels in Test 3 were evaluated for the difference in gloss between the left and right sides of the test panel. In Test 4, the panels were rated on a three-level scale (A>B>C: poor), with "A" indicating that the difference in gloss was not noticeable and "C" indicating that the difference in gloss was noticeable.

[0049] Test results The test results are shown in Table 1. All of Examples 1 to 7 gave good results.

[0050] [Table 1]

Claims

1. A water-based coating material comprising a synthetic resin emulsion and a pigment, The aqueous coating material has a pigment volume concentration of 30 to 70%; The pigments include a color pigment (b), an extender pigment (c) having an oil absorption of less than 50 ml / 100 g, and an extender pigment (d) having an oil absorption of 50 ml / 100 g or more, The weight ratio of the color pigment (b) to the extender pigment (c) is 100:(20 to 500); The weight ratio of the color pigment (b) to the extender pigment (d) is 100:(5 to 45). The aqueous coating material is characterized by:

2. 2. The aqueous coating material according to claim 1, wherein the proportion of said body pigment (d) is 4 to 40% by weight in the total amount of said color pigment (b), said body pigment (c) and said body pigment (d).

3. 3. The aqueous coating material according to claim 1, characterized in that the viscosity measured by a dynamic viscoelasticity measuring device is 0.5 Pa·s or less at a shear rate of 1000 s-1, and the viscosity measured by a dynamic viscoelasticity measuring device is 5 to 60 Pa·s at a shear rate of 0.1 s-1.

4. A method for applying an aqueous coating material, comprising applying the aqueous coating material described in any one of claims 1 to 3 using a roller and / or a brush.

5. The method for applying an aqueous coating material according to claim 4, characterized in that the amount of the aqueous coating material applied is 0.1 to 0.8 kg / m 2 .

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