JPH08209029A - Spherical delustering agent for coating material and coating material composition - Google Patents

Abstract

PURPOSE: To obtain the subject agent having high delustering effect and excellent coating property, coating-working property, physical properties of coated film and abrasion resistance, etc., by using specific spherical silica or silicate granules. CONSTITUTION: This delustering agent is composed of amorphous or fine laminar crystalline silica or silicate and has a composition of SiO2 :MO=100:0 to 50:50, preferably 100:0 to 70:30 in a weight ratio in terms of oxides (M is the group II metal in the periodic table), each granule is an independently spherical granule and the content percentage of the spherical granules having a ratio (DS/DL) of minor axis (DS) to major axis (DL) fallen within a range of 0.8-1.0 is >=80% and sharpness of grading distribution D25 /D75 is 1.2-2.0 (D25 is a granular diameter of 25% value in a cumulative grading distribution curve by a Coulter counter method; D75 is a granular diameter of 75% value in the curve) and a BET specific surface area of 30-800m<2> /g. The objective coating material composition containing the delustering agent preferably has a volume concentration of a delustering pigment (ml/g resin) of 0.1-0.3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spherical matting agent for paints and a matte coating composition using the same. More specifically, it has excellent dispersibility in paint resins and paint viscosity. The present invention relates to a delustering agent which has a small tendency to increase, has excellent coating workability, and has a coating film which is excellent in delustering effect, coating film properties and scratch resistance.

[0002]

2. Description of the Related Art Conventionally, silica fine powder has been used as a matting agent in paints for the purpose of reducing the gloss of the coating film surface. Are formed, thereby lowering the gloss value.

As such a matting agent silica, conventionally, a wet method silica, that is, a wet method silica obtained by neutralizing sodium silicate with an acid is used. For example, JP-B-55-6669 is used. Contains finely divided silica having a refractive index of greater than about 1.448 and a loss on ignition value of not more than 2%, which is obtained by performing a high temperature heat treatment at a high temperature of about 800 ° C. or higher after a wet process by a conventional method. A characteristic matte composition is described.

Further, in JP-A-1-298014, silica obtained by a wet method has an average particle size of 1 to 20.
A method for producing a matting agent for paints is described, which comprises pulverizing to a size of μm and then heat-treating at a temperature of 400 to 1000 ° C. for 30 to 120 minutes.

JP-A-2-289670 discloses an average particle size in the range of at least 1.0 ml / g of pore volume 1-10 microns and a specific particle size distribution when dispersed in a coating excipient. Matting agents consisting of an inorganic hydrogel having are described.

Further, JP-A-5-117548 discloses a matte coating composition characterized by containing fine silica powder and resin particles having a positive zeta potential and an average particle diameter of 0.01 to 5 μm. Has been described.

[0007]

The silica fine powder conventionally used for matting agents has a fine primary particle size, but is composed of amorphous secondary particles formed by agglomeration of these primary particles. There is a problem that the particle shape is indefinite, the particle size distribution is wide and asymmetric, and it is difficult to control the dispersed particle size in a state of being dispersed in the paint.

That is, there is a certain limit to the particle size of silica particles that effectively acts to reduce the gloss by forming irregularities on the surface of the coating film, and particles below this effective particle size are glossy on the surface of the coating film. There is a drawback in that it does not effectively serve to reduce the particle size, and that particles exceeding this effective particle diameter form lumps on the surface of the coating film, impairing the appearance characteristics and surface characteristics of the coating film. Moreover, the known silica-based matting agent can reduce the content of particles larger than the effective by pulverization or classification, but this increases the content of particles smaller than the effective particle diameter. This causes the following inconvenience.

First, since the content of particles having an effective particle size useful for reducing the surface gloss is small, it is necessary to increase the amount of silica-based delusterant compounded per paint, which requires a cost, and a compounding operation. Becomes troublesome. Also, when the paint contains particles having a particle size smaller than the effective particle size,
This causes a problem that the viscosity of the paint increases and the workability of the paint decreases, and due to the presence of small particle size particles present in the paint, the hue of the paint film becomes dull and the toughness of the paint film increases. There is also a drawback that mechanical properties such as sex are deteriorated. In addition, a coating film containing agglomerated particles having a small particle size has a large tendency to be scratched on the surface due to friction or the like.

Further, the known amorphous silica matting agent has a tendency to disintegrate due to shearing force when dispersed in a paint even if it has a particle size composition which is satisfied to some extent before blending (discoloration). Integration), which inevitably leads to the drawbacks mentioned above.

Therefore, the object of the present invention is to achieve a high matting effect with a relatively small amount of compound, and to have excellent dispersibility in the paint resin, and to reduce the tendency to increase the viscosity of the paint. Another object of the present invention is to provide a matting agent and a matting coating composition which have excellent coating workability and in which the coating film formed is excellent in the matting effect, various coating film properties and scratch resistance.

Another object of the present invention is silica or silica in which the volume of matting agent required to achieve the same level of matting is reduced to a significantly smaller volume than conventional silica based matting agents. The purpose is to provide an acid-based matting agent.

[0013]

According to the present invention, a composition of SiO ₂ : MO = 100: 0 to 50:50 expressed as a weight ratio based on an oxide (wherein M is a Group II metal of the periodic table). Of the silica or silicate, which is amorphous or finely layered crystallographically in X-ray diffraction and has a distinct spherical shape in which each particle is independent and has a long diameter (D _L ) and a short diameter. (D _S)
The sphericity represented by the ratio (D _S / D _L ) is 0.8 to 1.0
Is 80% or more, and in the formula (1) D ₂₅ / D ₇₅ (1), D ₂₅ represents the particle size of 25% of the volume-based cumulative particle size distribution curve by the Coulter counter method, and D ₇₅ is Spherical silica characterized in that the sharpness of the particle size distribution defined by expressing the particle size of 75% value is 1.2 to 2.0 and the BET specific surface area is in the range of 30 to 800 m ² / g. There is provided a matting agent for coatings which comprises silicate particles. According to the present invention, the loose apparent density is also 0.1.
Matting agent for coatings consisting of spherical silica or silicate particles, characterized by having a range of 5 to 0.3 g / ml and a refractive index measured by a liquid immersion method of 1.40 to 1.55 An agent is provided.

According to the present invention, a matting coating composition characterized by containing the above-mentioned matting agent, in particular, the following formula (2) GPV = P / 100Pa (2) where P is 60 ° It is the number of g of the matting pigment added per 100 g of the coating resin required to satisfy the reflectance of 50% in gloss, and Pa is the loose apparent density (g / m) of the matting pigment.
l), the matte pigment volume concentration (ml /
(g resin) is provided in the range of 0.1 to 0.3.

[0015]

The matting agent used in the present invention is represented by a weight ratio based on oxides: SiO ₂ : MO = 100: 0 to 50:50, particularly 100: 0 to 70:30, where M is a periodic table X-ray diffractiometrically amorphous or finely layered crystalline silica or silicate with a composition that represents a Group II metal. (1) Individual particles must be independent and distinct spherical particles. , (2) the particles of the long diameter (D _L) and the minor axis% by number (D _S) of the ratio (D _S / D _L) in sphericity of 0.8 to 1.0 of particles represented 80 % Or more, (3) the sharpness (D _S ) of the particle size distribution defined by the formula (1) is in the range of 1.2 to 2.0,
And (4) BET specific surface area of 30 to 800 m ² / g
It has a remarkable characteristic of being in the range of, and more preferably (5) the loose apparent density is 0.1.
It is also a remarkable feature that it is in the range of 5 to 0.3 g / ml, and additionally (6) the refractive index measured by the liquid immersion method is in the range of 1.4 to 1.55. The matte coating composition of the present invention is characterized by containing the above-mentioned matting agent.
The matte pigment volume concentration defined by the formula (2) is 0.1.
To 0.3 (ml / g resin) is also a remarkable feature.

The attached drawings FIGS. 1, 2, 3 and 4 show a matting agent of the present invention having a median diameter of 2.9 μm, a matting agent of the present invention having a median diameter of 6.4 μm, and a conventional matting agent, respectively. Scanning electron microscope showing the particle structure of (Mizukasil P-526 manufactured by Mizusawa Chemical Industry Co., Ltd., median diameter 3.2 μm) and other conventional matting agents (Syroid # 244 manufactured by Company F, median diameter 2.1 μm). It is a photograph.

1 to 4 are compared with each other, the conventional matting agent is amorphous agglomerated particles in which silica fine particles (primary particles) are randomly agglomerated, and the aggregation distribution of the agglomerated particles is remarkably broad. (Figs. 3 and 4)
It can be seen that in the matting agent used in the present invention (FIGS. 1 and 2), each particle is a clear and independent spherical particle, and the particle size distribution is a uniform particle size distribution close to monodisperse.

The attached drawings, FIG. 5, FIG. 6, FIG. 7 and FIG. 8 show the surface of the coating film formed from the paint containing the matting agent shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, respectively. FIG. 9 is a scanning electron micrograph showing the distribution structure of the matting agent particles in Example 1. However, when a conventional matting agent is used, the shape of the protrusions on the surface of the coating film is also unsatisfactory as shown in FIGS. 7 and 8. In the case of using the matting agent of the present invention, the shapes of the projections on the surface of the coating film are partial spheres, and the shapes thereof are partially spherical, while the shapes are not uniform and the sizes are remarkably irregular. It can be seen that its size is also generally uniform.

Furthermore, the attached drawings, FIGS. 9, 10, 11 and 12 show the cross-sections of the coating film formed from the coating material containing the matting agent shown in FIGS. 1, 2, 3 and 4, respectively. Is an electron micrograph showing the dispersed structure of the matting agent particles,
When a conventional matting agent is used, as shown in FIGS. 11 and 12, in addition to particles useful for forming unevenness on the surface of the coating film, fine particles not useful for forming unevenness, particularly fine particles that are believed to be due to particle collapse. Is dispersed and contained in the coating resin, whereas when the matting agent of the present invention is used, as shown in FIGS. It can be seen that the particles are dispersed and contained in various particle sizes.

FIG. 13 shows the various matting agents described above.
The relationship between the amount of the coating film blended in the paint and the matting effect (60 ° gloss) is plotted, but the matting agent of the present invention is significantly less than conventional matting agents. It is clear that the compounding amount shows a great matting effect.

In the present invention, the true sphericity and the independence of the particles in the above constitutions (1) and (2) means that the matting agent has excellent dispersibility in the coating resin and the matting agent particles are It has the function of allowing the particles to exist stably in the coating film without destroying the particle structure and particle size, and also to maintain the shape of the convex portions on the surface of the coating film in a uniform and smooth spherical shape.

The smooth spherical projection shape of the coating film surface is
As shown in the examples described later, it not only imparts abrasion resistance to the surface of the coating film, but also imparts stable and sustained mattness to the surface of the coating film.

Further, the uniformity (D _s ) of the particle size of the above-mentioned constitution (3) increases the proportion of particles actually contributing to the matting among the matting agent particles compounded in the paint, so that the compounding amount is small. It produces a great matting effect.

Further, the specific surface area (S _A ) of the constitution (4)
Defines the internal structure and structure or stability of the matting agent particles. If the specific surface area is larger than the above range, the particle strength is insufficient and the particles tend to be crushed during the preparation of the paint, or moisture absorption. May adversely affect the coating film, and if it is smaller than the above range, the dispersion stability in the coating composition tends to be lowered.

Further, the loose apparent density of the constitution (5) is in the range of 0.15 to 0.3 g / ml, and the density is 2 to 4 times that of the conventional amorphous matting agent. The appearance of the pigment powder is larger than that of the conventional one, and the workability and the storability thereof are not comparable to those of the conventional bulky amorphous delusterant. Furthermore, the refractive index of the above-mentioned constitution (6) substantially corresponds to the refractive index of the coating resin, and is useful for improving the hue and appearance characteristics of the coating film.

The volume concentration of the matte pigment (G) of the above constitution (7)
PV) represents the volume of the delusterant effectively acting on the delusterant per the number of resin g in the coating film to be formed. Four
To 0.5 ml / g resin, in the present invention, it is in the range of 0.1 to 0.3 ml / g resin, preferably 0.2 ml / g resin or less, and the same matte It is clear that the volume of matting agent required to achieve the level has been reduced to a significantly smaller volume compared to conventional silica-based matting agents. This is the attached drawing showing the cut surface of the coating film described later, FIG. 9, FIG. 10, FIG.
2. From FIG. 11 and FIG. 12 of the conventional coating film cut surface as compared with FIG. 9 and FIG. 10 of the present invention, the pigment is contained in the coating film surface below the surface of the coating film in a state where it cannot contribute to the matting effect. It is in good agreement with the fact that it is observed as a large amount.

According to the present invention, as described above, a high matting effect can be achieved with a relatively small amount of the compound, the dispersibility in the paint resin is excellent, and the tendency to increase the viscosity of the paint is small. It has the advantages that it has excellent coating workability, and that the coating film formed is excellent in matte effect, various coating film physical properties, and scratch resistance.

[0028]

Preferred Embodiment of the Invention

[Delusterant] The delusterant used in the present invention is represented by a weight ratio based on oxides and is SiO ₂ : MO = 100: 0 to 5.
It is composed of silica or silicate having a composition of 0:50, preferably 99: 1 to 50:50 (wherein M represents a Group II metal of the periodic table), and is amorphous to X-ray diffraction. a fine layered crystal, sphericity represented by the particles with distinct spherical individual particles independent long diameter (D _L) and the minor axis (D _S) ratio (D _S / D _L) is 0 80 to 80% by number of particles having a particle size of 8 to 1.0, and in the formula D ₂₅ / D ₇₅ formula, D ₂₅ represents the particle size of 25% of the volume-based cumulative particle size distribution curve by the Coulter counter method, and D ₇₅ Represents the particle size of the 75% value. Has a sharpness of particle size distribution of 1.2 to 2.0, especially 1.2 to 1.6, and a BET specific surface area of 30 to 800 m ² / g, especially 1
It is in the range of 00 to 500 m ² / g.

The spherical particles of silica or silicate used as the matting agent in the present invention are porous because they are aggregates of silica primary particles, and therefore have a relatively large BET specific surface area as described above, and It has a pore volume distribution peak at a pore radius of 10 to 100 Å and a pore volume of 0.2 to 2.0 cc / g as measured by a nitrogen adsorption method.

The spherical particles have an oil absorption of 50 to 300.
It is a porous particle in the range of ml / 100 g, and its refractive index (25 ° C., liquid immersion method) is generally 1.40 to 1.55.
Is in the range.

The spherical particles have a primary particle size of 1 to 10 μm as determined by scanning electron microscopy, and have an apparent density (JI
SK-6220 method) is 0.1 to 0.5 g / ml.

The porous particles are, in one preferred embodiment, spherical amorphous silica particles, in another embodiment,
It is an amorphous or layered microcrystalline silicate, and examples of the Group 2 metal in the silicate include zinc, magnesium, calcium, barium, and strontium.

It is preferable that the spherical silicate particles are any one of magnesium phyllosilicate, zinc phyllosilicate and zinc aluminum phyllosilicate.

[Production Method of Matting Agent] The porous spherical silica or silicate particles used in the present invention are obtained by growing a partially neutralized product of alkali silicate into a spherical shape by using a water-soluble polymer as an aggregative growth agent. Or by further reacting the particulate matter with a hydroxide or salt of a Group II metal of the periodic table in an aqueous solvent.

1. Alkali silicate As the alkali silicate, m is a number of 1 to 4, particularly 2.5 to 3.5 in the formula Na ₂ O · mSiO ₂ formula. An aqueous solution of an alkali silicate having the composition of, especially sodium silicate, is used.

The composition of the alkali silicate is related to the stability of the mixed solution and the yield and particle size of the formed particles. When the molar ratio (m) of SiO ₂ is smaller than the above range, precipitation of partially neutralized particles becomes difficult to occur, yield tends to decrease, particle shape and particle morphology are likely to be uneven, and a large amount is required for partial neutralization. This is not preferable because it requires the above acid. On the other hand, S
If the molar ratio of iO ₂ is larger than the above range, the stability of the mixed solution is lowered and the particle morphology deviates from the true spherical shape, and the particle size distribution is not sharp.

The concentration of alkali silicate is S in the mixed solution.
The concentration of iO ₂ is preferably in the range of 3 to 9% by weight, particularly 5 to 8% by weight.

2. Coagulation Growth Agent As the water-soluble organic polymer that is the coagulation growth agent, anionic or nonionic water-soluble organic polymer is used.
Examples of the anionic polymer include sodium polyacrylate, or a copolymer of sodium polyacrylate and polyacrylamide, sodium polymethacrylate,
Sodium alginate, ammonium alginate, carboxymethyl starch, carboxymethyl cellulose, acrylamide-acrylic acid copolymer, maleic anhydride-vinyl ether copolymer, chitosan, sodium styrenesulfonate copolymer and the like are used. Nonionic polymers include polyacrylamide, polyvinyl alcohol (PVA), starch, cyanated starch, methyl cellulose,
Examples include ethyl cellulose, hydroxyethyl cellulose, bee gum, gelatin, polyethylene glycol and the like.

These water-soluble polymers can be used alone or in combination of two or more.

A particularly preferred cohesive growth agent is carboxymethyl cellulose (CMC) with a degree of etherification of 0.5 to 2.5, especially 0.8 to 2.0. The viscosity of CMC depends on the degree of polymerization of the cellulose molecule that is the skeleton of CMC, and if the viscosity is high, it tends to be difficult to form and precipitate the particulate matter, and to separate by filtration. It is preferably in the range of 3000, particularly 200 to 1000. Since CMC is easily dissolved in water, it may be added as a powder when used, but it is easier to handle if it is used as an aqueous solution in advance.

Another preferable example of the coagulation growth agent is an acrylamide polymer. This acrylamide-based polymer may be a homopolymer of acrylamide, and is copolymerizable with acrylamide within a range in which the acrylamide repeating unit constitutes 70 mol% or more, particularly 90 mol% or more of the whole. It may contain repeating units of various monomers, for example, ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and fumaric acid, vinyl ethers, (meth) acrylic acid esters and the like. Further, the acrylamide polymer may contain an anionic unit modified to a carboxyl group by hydrolysis or a cationic unit esterified with an aminoalkyl group or a quaternary ammonium alkyl group. It is preferable that the acrylamide polymer is not so high in molecular weight, and its weight average molecular weight (M _W ) is generally in the range of 10,000 to 3,000,000, and particularly 100,000 to 2,000,000.

A coagulant growth agent such as carboxymethyl cellulose (CMC) is used as a total silica (S) in an alkali silicate solution.
It is preferably used in an amount of 1 to 100% by weight, particularly 5 to 50% by weight, based on iO ₂ weight).

Although it is particularly effective in the case of CMC, it is also possible to use a combination of coagulation and growth aids composed of a water-soluble inorganic electrolyte or other water-soluble polymer. As the water-soluble inorganic electrolyte, any one can be used as long as it is a water-soluble inorganic electrolyte that has an aggregating action on a sol or the like. 3rd, 4th
Mineral or organic acid salts of group metals or other transition metals are used, suitable examples of which are:

Alkali metal salts such as NaCl, Na ₂
Alkali metal salts such as SO ₄ ; Alkaline earth metal salts such as calcium chloride, magnesium chloride, magnesium sulfate, calcium nitrate; zinc chloride, zinc sulfate, aluminum sulfate, aluminum chloride, titanyl sulfate, etc. Other water-soluble metal salts of

Of these, alkali metal salts are one of the preferred coagulation growth aids. This is because the alkali metal salt is a component that is a by-product during partial neutralization and complete neutralization, and is contained in the filtrate from which the final granular silica has been separated, and it must be reused and added to the mixed solution. This makes it possible to effectively reuse the collected CMC together with the collected CMC.

On the other hand, the polyvalent metal salt has a larger aggregating action on the sol than the monovalent metal salt, and the aggregating and growing action of the partially neutralized silica is large when added in a small amount as compared with the monovalent metal salt. Therefore, when the polyvalent metal species is allowed to be mixed, it is also acceptable to use the polyvalent metal salt.

Other water-soluble polymers exemplified above can also be used as the coagulation / growth aid.

3. Partial Neutralization and Aggregate Growth As the acid used to neutralize the alkali silicate, various inorganic acids and organic acids are used, but from an economic point of view, sulfuric acid,
Mineral acids such as hydrochloric acid, nitric acid and phosphoric acid are preferably used, and among these, sulfuric acid is the most excellent in terms of yield of granules, particle size and uniformity of morphology.

To carry out a homogeneous reaction, the acid is preferably used in the form of a dilute aqueous solution, generally in a concentration of 1 to 15% by weight. Further, a neutral salt may be added to these acids. The amount of acid used during mixing is such that a homogeneous mixed solution (clear) is produced by partial neutralization, and the pH of the mixed solution is 10.2 to 11.
It is preferable to use it in an amount of 2, especially 10.5 to 11.0.

In the synthesis of porous spherical silica or silicate particles, there is no limitation on the order of addition of the above-mentioned respective components. For example, after the acid is added to the aqueous alkali silicate solution, the water-soluble polymer or the aggregation promotion described further below is promoted. The nucleating agent may be added, or conversely, the water-soluble polymer or the nucleating agent may be added to the aqueous alkali silicate solution, and then the acid may be added. Of course, these may be added at the same time.

A water-soluble polymer other than CMC is particularly effective, but an amorphous silica nucleating agent for promoting aggregation can be used, and any nucleating agent can be used as long as the particle size is fine. Silica sol, silica gel or anhydrous silica powder is used. Submicron particles with a particle size of 1 μm or less, 1 to 20 based on SiO _{2 based on the} total weight of silica.
% Is preferably added in advance.

As the silica sol, Snowtex (manufactured by Nissan Kagaku Co., Ltd.) Lyudox or the like is preferably used, but an acidic silica sol obtained by treating an alkali silicate with a mineral acid can also be used.

Aerosil (manufactured by Nippon Aerosil Co., Ltd.), fumed silica (manufactured by WR Grace) and the like are preferably used as the anhydrous silica powder having a fine particle diameter. These dry process silicas have a fine primary particle size, but they are aggregated into fairly large secondary particles, so they are preferably wet pulverized and used as a slurry having a dispersed particle size of 1 μm or less. In addition, silica obtained by hydrolyzing an organic silane has a small primary particle size and few agglomerated particles,
It is suitable for the purpose of the present invention.

Furthermore, a sol and a slurry comprising submicron particles of hydroxides and oxides of titanium, zirconium, tin, etc. other than silica are added to the mixed solution, and these submicron particles are uniformly dispersed in the aggregate particles. It is also possible to obtain spherical silica particles dispersed and contained in.

In the coagulation growth of the neutralized product, the above components are thoroughly mixed and homogenized, and then the mixed solution is allowed to stand to precipitate the partially neutralized granular product.

The deposition conditions are generally 1 to 10
It is suitable to leave it at a temperature of 0 ° C. for about 1 to 50 hours.
Generally, the lower the temperature, the larger the particle size of the deposited particles, and the higher the temperature, the smaller the particle size of the deposited particles. Thus, by controlling the temperature, the particle size of the produced granules can be controlled.

The precipitated particles are separated from the mother liquor, and the dispersed particles are neutralized by adding an acid, and then washed with water, dried, classified and the like to obtain a product. Since the separated mother liquor and the separated liquid after neutralization contain unprecipitated silica and water-soluble polymer, these can be effectively used for the next mixed precipitation.

4. Synthesis of silicate When synthesizing a spherical silicate, spherical particles consisting of partially or completely neutralized products of alkali silicate obtained by the above method and one of hydroxides or salts of Group II metal of the periodic table Or 2
The seed or species are reacted in the presence of an aqueous medium.

The hydroxides and salts of Group II metals of the periodic table include hydroxides of magnesium, calcium, barium, strontium and zinc, inorganic acid salts such as nitrates, chlorides and sulfates, and acetates. , An organic acid salt such as a sulfonate can be used.

When the spherical particles used as the precursor are completely neutralized products of alkali silicate, that is, amorphous silica, it is preferable to use hydroxide. Because this combination does not contain other contaminant ions,
It is excellent in terms of the purity of the silicate and the convenience of the manufacturing operation.

On the other hand, when the spherical particles used as the precursor are partially neutralized products of alkali silicate, it is preferable to use a metal salt or a combination of a metal salt and a metal hydroxide as a raw material. This is because the metathesis reaction occurs between the alkali silicate content remaining in the spherical particles and the metal salt, and the production of the metal silicate proceeds smoothly and efficiently.
Of course, it is desirable that the alkali content in the spherical particles and the acid radical of the metal salt have an equivalent relationship.

The reaction between the granular material composed of a partially or completely neutralized product of alkali silicate and the metal hydroxide should be carried out in the above-mentioned quantitative ratio. This reaction is preferably carried out in an aqueous medium, and when an excess amount of alkali or acid radicals is present in the reactant, an acid or alkali corresponding to this can be added to the aqueous medium.

The reaction conditions are not particularly limited as long as the granular structure of the precursor is maintained and the silicate is formed, and the reaction temperature is generally 50 to 300 ° C., particularly 90 to 200 ° C. The reaction time is preferably 0.5 to 100 hours, particularly 2 to 8 hours. During the reaction, the concentration of SiO ₂ in the aqueous medium is preferably in the range of 2 to 30% by weight, particularly 5 to 25% by weight, and the order of the reaction is such that the metal hydroxide is added to the aqueous dispersion of the silica precursor. Alternatively, a one-sided pouring method of pouring salt, a simultaneous pouring method of pouring both raw materials into an aqueous medium, a simultaneous charging method of heating an aqueous medium in which both raw materials are dispersed to a predetermined concentration, or the like can be adopted.

The spherical silicate particles thus obtained are separated from the reaction mother liquor by a solid-liquid separation method such as filtration, washed with water if necessary, and dried at a temperature of up to 150 ° C., or at a temperature of 150 to 1000 ° C. Calcination produces spherical silicate particles. In the case of calcination, the specific surface area, pore volume or moisture absorption of the spherical silicate particles can be reduced with increasing temperature.

[Modification Treatment] The amorphous silica or silicate particles used in the present invention have the surface thereof made of an inorganic oxide in order to prevent sedimentation or improve compatibility with a resin or a solvent. For example, titanium oxide, silicon oxide, zirconium oxide, zinc oxide, barium oxide, magnesium oxide, calcium oxide; silane-based, titanium-based or zirconium-based coupling agents may be coated or surface-treated.

The granular amorphous silica is desired to be metal soap, resin acid soap, various resins or waxes, silane or titanium coupling agents, various metal oxides or hydroxides, silica coating, and the like. Can be applied by.

In the present invention, the above-mentioned porous silica or silicate spherical particles may be used alone as a delustering agent, or may be used in combination with other fillers and pigments in the formulation of paint. As the inorganic component used in combination, alumina,
Attapal guide, kaolin, carbon black, graphite, finely divided silicic acid, calcium silicate, diatomaceous earth,
Magnesium oxide, magnesium hydroxide, aluminum hydroxide, slate powder, sericite, flint, calcium carbonate, talc, feldspar powder, molybdenum disulfide, barite, vermiculite, whiting, mica, wax stone clay,
Gypsum, silicon carbide, zircon, glass beads, shirasu balloon, asbestos, glass fiber, carbon fiber, rock wool, slag wool, boron squid, stainless steel fiber, titanium white, zinc flower, red iron oxide, iron black,
Examples include yellow iron oxide, zeolite, hydrotalcite, lithium, aluminum, carbonate, titanium yellow, chrome oxide green, ultramarine blue and navy blue.

[Coating Composition] According to the present invention, the spherical silicic acid or silicate particles are blended into a coating composition known per se to give a matte coating composition.

As paints, oil-based paints, nitrocellulose paints, alkyd resin paints,
Amino alkyd paints, vinyl resin paints, acrylic resin paints, epoxy resin paints, polyester resin paints, chlorinated rubber paints, and other commonly known paints, as well as rosin, ester gum, pentaresin, coumarone indene resin, phenol Resin, modified phenolic resin, maleic resin, alkyd resin, amino resin, vinyl resin, petroleum resin, epoxy resin, polyester resin, styrene resin, acrylic resin, silicone resin, rubber base resin Examples include paints containing one or more of resins, chlorinated resins, urethane resins, polyamide resins, polyimide resins, fluorine resins, natural or synthetic lacquer and the like.

The paint used may be any of solvent-based paints, water-based paints, UV-curable paints, powder paints and the like, depending on the way of use, but the present invention is applicable to solvent-based paints and water-based paints. Particularly suitable.

As the organic solvent of this solution type coating material, aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as n-heptane, n-hexane and isoper; alicyclic carbonization such as cyclohexane. Hydrogen-based solvent; ketone-based solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohol-based solvent such as ethanol, propanol, butanol, diacetone alcohol; ether-based solvent such as tetrahydrofuran and dioxane; cellosolve such as ethyl cellosolve and butyl cellosolve One or more solvents such as system solvents; ester solvents such as ethyl acetate and butyl acetate; aprotic polar solvents such as dimethylformamide, dimethylacetamide and dimethylsulfoxide can be used. The concentration of the resin component in the raw material solution is generally 5 to 70% by weight, especially 1
Suitably it is in the range of 0 to 60% by weight.

As the water-based paint, a self-emulsifying type or a surfactant emulsifying type paint is used in addition to an aqueous solution type paint. Examples of the resin of the water-based paint include alkyd resin, polyester resin, acrylic resin, epoxy resin, or a combination of two or more of these which are water-solubilized or self-emulsified in an aqueous medium. In the self-emulsifying resin, the self-emulsifying property is imparted by neutralizing the carboxyl group with ammonia or amines or by quaternizing the contained amine. Also, various latex resins are used. Resin concentration is generally 1
It is suitable to be in the range of 0 to 70% by weight, especially 20 to 60% by weight.

As the ultraviolet (UV) curable coating material, high solid resin, for example, UV curable acrylic resin, epoxy resin, vinyl urethane resin, acrylic urethane resin, polyester resin or the like is used alone or in combination of two or more kinds. It

As the powder coating material, in addition to thermoplastic resins such as polyamide, polyester, acrylic resin, olefin resin, cellulose derivative, polyether and vinyl chloride resin, epoxy resin, epoxy / novolac resin, isocyanate or epoxy curing type polyester resin can be used. Etc.

According to the present invention, the above matting agent is added to the above coating material in a volume concentration of matting pigment (ml / g resin) defined by the formula (2) of 0.1 to 0.3. Formulate to be within the range. As a result, a high degree of matting effect can be imparted to the coating film surface with a small amount of compounding.

[0076]

The invention is explained in greater detail in the examples below. The physical properties of the matting agent and the like used in the present invention and the evaluation method are as follows.

(1) Apparent Density It was measured according to JIS K-6220.6.8.

(2) Oil absorption amount Measured according to JIS K-5101.19.

(3) Specific Surface Area, Pore Volume Sorptomatic Seri by Carlo Erba
It was measured by BET method using es1800.

(4) Grain size Aperture tube 50 μm by a Coulter counter (TA-II type manufactured by Coulter Electronics Co.)
It was measured using m.

(5) Particle size by SEM Representative particles are selected from the photographic images obtained with a scanning electron microscope (S-570 manufactured by Hitachi), and the major axis and minor axis of the particle image are measured using a scale. Was shown as the primary particle size.

(6) Sphericity Representative particles are selected from the photographic images obtained with a scanning electron microscope (S-570 manufactured by Hitachi), and the major axis and minor axis of the particle image are measured using a scale. It was calculated from the following formula. Sphericity = short diameter (D _S) / long diameter (D _L)

(7) Matting effect test method This coating material 1 was prepared by using a baked melamine coating material (Amilac # 1400 manufactured by Kansai Paint Co., Ltd.) as a coating film forming agent.
5 parts of a matting agent sample was added to 00 parts by weight and dispersed for 5 minutes at 2500 rpm using a disper disperser, and then coated on mirror-coated paper using a bar coater # 14 and allowed to stand at room temperature for 20 minutes, then A coated plate was prepared by baking at 140 ° C. for 20 minutes. Then, 60 ° gloss (gloss ratio (%)) was measured using a digital gloss meter GM-3D manufactured by Murakami Color Research Laboratory.

(8) Friction test (scratch resistance) Test piece 1 (3 × 3 cm cut paper) and test piece 2 (20 × 4 cm cut paper) were prepared from the coated paper obtained in (7),
Test piece 1 was fixed on a glass plate with the coating film of test piece 2 facing up.
Place the coating so that it will fit the test piece 2. At this time, a 900 g weight was placed on the test piece 1 and a load of 100 g per 1 cm ² was applied. Next, the test piece 1 was moved from end to end of the test piece 2 and the surface state of the rubbed coated plate was observed. The scratch resistance of the coating film was evaluated by the following visual observation with respect to the number of times of friction (reciprocation / cycle) 5, 15, and 25.

[0085]

[Table 1]

(9) Matte Volume Pigment Concentration (GPV) In the present invention, the matte volume pigment concentration (GPV) obtained by the following formula was defined, and the matteness (level) of the pigment was evaluated. (1) Using the test piece obtained in accordance with the evaluation method described in (1), the number of pigment additions per 100 g of coating resin required to satisfy a gloss level of 50% at 60 ° gloss In the present invention, it is defined as a volume value of the pigment occupying in the coating film per g of the coating film forming resin unit, which is a value removed by the apparent density. GPV = P / 100 Pa (ml / g resin) P: Number of g of pigment added per 100 g of resin Pa: Loose apparent density of pigment (g / ml) It should be noted that the smaller this value, the higher the matting level. .

(10) Loose apparent density It is measured by a powder tester as follows. 10
The sample is poured into a 0 ml cup with a funnel, and when the cup overflows, the pouring is finished. After that, the cup is cut with a cutting edge and the weight is measured to loosen the apparent density (g
/ Ml) is calculated. Loose apparent density = sample weight (g) / 100 (ml)

(11) Matting Stability of Paint Baking melamine paint (Amilac # manufactured by Kansai Paint Co., Ltd.)
1400) and the sample is added so that the 60 ° gloss becomes 20%, and the disperser rotation speed is 1,000, 300.
The mixture was stirred and dispersed by changing each to 0,5000 rpm, and was applied to the mirror-coated paper with a bar coater # 14, and was applied at room temperature for 20
Set for minutes, then bake at 140 ℃ for 20 minutes,
The stability of the matte paint is evaluated by measuring 60 ° gloss and defining it as shown in Table 2 below from the dispersibility of the pigment and the matting ability by the stirring shearing force when preparing the paint by dispersing the pigment in the vehicle. did.

[0089]

[Table 2]

(12) Viscosity of paint Resin made by Kansai Paint Co., Ltd. (Amilak No. 140)
0) 100 parts by weight, 60 ° gloss value is 20
%, 50%, add the sample and disperse 2
After dispersion under the condition of 000 rpm for 5 minutes, using a B-type viscometer manufactured by Tokyo Keiki Co., Ltd., a temperature of 25 ° C.
The measurement was performed under the conditions of rpm and 60 rpm. The number of added parts of each sample having a gloss value of 20% and 50% was as follows.

[0091]

[Table 3]

Example 1 183 kg of No. 3 sodium silicate was weighed in a stainless steel reaction tank equipped with a stirrer and having an internal volume of 0.75 m ³ , and water of 42 kg was used.
After the addition, 107 kg (CMC / SiO ₂ = 0. 0) of a 3% aqueous solution of carboxymethyl cellulose (hereinafter referred to as CMC, degree of etherification 1.25, degree of polymerization about 550, 1% aqueous solution viscosity 75 cp / 25 ° C.) was added with stirring. 08) In addition,
After sufficiently dispersing, the temperature was adjusted to 20 ° C.

Then, while stirring, the temperature was adjusted to 20 ° C. in advance.
% Sulfuric acid 168 kg (H ₂ SO ₄ / Na ₂ O = 0.41)
Was slowly added (pH after addition of sulfuric acid was 10.8), stirring was stopped after the addition was completed, and the mixture was allowed to stand at that temperature for 12 hours. (After standing for 12 hours, the mixture was stirred and dispersed to separate the precipitate and mother liquor by filtration, and the obtained cake was redispersed in water to sufficiently disperse it, and then p
5% sulfuric acid (about 100 kg) was added until H reached 3.0, and when the pH was almost stable at 3.0, the mixture was stirred for 2 hours as it was, filtered and washed with water, and the cake was repulped to obtain a concentration of 15%. Spherical silica particle slurry of
o. 1-1).

Next, this cake was dried overnight in a constant temperature dryer at 110 ° C. and then pulverized with a sample mill to give a particle size of 4 to 4.
A 6 μm porous spherical silica matting agent was prepared and its properties are shown in Table 4.

Example 2 Commercially available sodium silicate No. 3 (SiO ₂ 21.9%, Na ₂ was added to a reaction layer made of stainless steel equipped with a stirrer with an internal volume of 0.75 m ^3.
O 7.1%, SiO ₂ / Na ₂ O = 3.19) 16
Weigh 0 kg (7% as SiO ₂ concentration in the total liquid volume),
After adding 160 kg of water, the temperature was adjusted to 20 ° C. and 105 kg of an aqueous solution of acrylamide polymer (10% aqueous solution, average molecular weight 500,000) was added while slowly stirring (SiO ₂
Disperse well (30% as polyacrylamide anhydride) per minute.

Then, 1% of 5% sulfuric acid adjusted to 20 ° C. in advance
25 kg was added in about 3 minutes (pH after completion of addition was 10.
It was 8), stirring was stopped after the addition was completed, and the mixture was allowed to stand for 12 hours. (After standing for 12 hours, the mixture was stirred and dispersed to separate the precipitate and the mother liquor by filtration, and the obtained cake was redispersed in water and sufficiently dispersed, and then 5% sulfuric acid (about 100 k
g) was added, and when the pH was substantially stable at 2.0, the mixture was stirred for 2 hours, filtered and washed with water, and the cake was repulped to obtain a spherical silica particle slurry having a concentration of 15%.

Next, this cake was dried overnight in a constant temperature dryer at 110 ° C. and then pulverized with a sample mill to give a particle size of 2 to 2.
A 3 μm porous spherical silica matting agent was prepared and its properties are shown in Table 4.

Example 3 128 kg of sodium silicate No. 3 used in Example 1 was placed in a stainless steel reactor having an internal volume of 0.75 m ³ equipped with a stirrer.
Weigh out, add 116 kg of water, then 5 wt with stirring
% 115% sulfuric acid was added (H ₂ SO ₄ / Na ₂ O = 0.
4), pH was adjusted to 10.5 and kept at 20 ° C.

With further stirring, 60 kg of silica sol (Snowtex C manufactured by Nissan Chemical Co., Ltd.) was added slowly so as not to cause cloudiness, and 100 kg of a 4 wt% solution of sodium alginate, which is a weak anionic polymer, was added and sufficiently dispersed. After that, the stirring was stopped and the mixture was allowed to stand at that temperature for 12 hours.

Thereafter, a sample of the porous spherical silica matting agent having a particle size of about 6 to 10 μm was prepared in the same manner as in Example 1,
This property is shown in Table 4.

Example 4 Sample No. 1 of Example 1 was placed in a 20 L stainless steel container. 1
-1 Weighing 15 kg of slurry, for the solid content, M
Magnesium hydroxide powder (# 200 manufactured by Kamishima Chemical Co., Ltd.) corresponding to 20% in terms of gO was added, sufficiently dispersed, heated to 98 ° C. in a warm bath, and treated at that temperature for 8 hours,
After filtering, washing with water, drying at 110 ° C., pulverizing with a sample mill, and then firing at 400 ° C. for 1 hour, a spherical porous magnesium silicate delusterant sample was prepared, and its properties are shown in Table 4.

Example 5 Sample No. 1 of Example 1 was placed in a stainless steel beaker having an internal volume of 1 L. 800 g of 1-1 was weighed, and zinc hydroxide was used as ZnO in place of magnesium hydroxide of Example 4 to obtain 20%.
And added to the autoclave with an internal volume of 1 L and heated to 180 ° C. under stirring (pressure 9 kg / cm ² ),
It was treated for 5 hours. After that, filtration, washing with water, drying, crushing and firing were carried out to obtain a spherical zinc silicate-based matting agent. The properties of this matting agent are shown in Table 4.

Example 6 Pure water was added to 50 g of the powder obtained in Example 5 to prepare a slurry of spherical zinc silicate particles having a solid content concentration of 10%.

Next, the slurry was heated and stirred at 50 ° C., and the aluminum chloride solution having an Al ₂ O ₃ concentration of 5% and 4% were added.
The sodium hydroxide solution was used to simultaneously pour the solution within a pH range of 7 to 9 over 1 hour, and the coating reaction was carried out so that it would be 8% in terms of Al ₂ O ₃ . The aluminum compound-coated spherical zinc silicate matting agent was prepared in the same manner, and the properties thereof are shown in Table 4.

Comparative Example In order to clarify the characteristics of the matting agent according to the present invention, Mizusuka Chemical's Mizukasil P-5, which is a commercially available amorphous silica matting agent, is used.
26 and Syroid # 244 of Company F were similarly compared and evaluated, and the results are shown in Table 4.

[0106]

[Table 4]

[0107]

INDUSTRIAL APPLICABILITY According to the present invention, by using specific spherical silica or silicate particles as a delustering agent for paint, a high delustering effect can be achieved with a relatively small amount of the compound, and at the same time in the paint resin. It has excellent dispersibility in paint, has little tendency to increase the viscosity of paint, and has excellent coating workability,
Moreover, the coating film formed has the advantage that it has excellent matte effect, various physical properties of the coating film, and scratch resistance.

According to the invention, the volume of the matting agent in the coating required to achieve the same level of matting is also reduced to a significantly smaller volume than conventional silica-based matting agents. A silica or silicate based matting agent could be provided.

[Brief description of drawings]

FIG. 1 is a scanning electron microscope (SEM) photograph showing the particle structure of the matting agent according to Example 1 of the present invention.

FIG. 2 is an SEM photograph showing the particle structure of the matting agent of Example 3 as well.

FIG. 3 is respective SEM photographs showing the particle structure of Mizukacil P-526.

FIG. 4 SEM showing the grain structure of Syloid # 244.
It is a photograph.

FIG. 5 is an SEM photograph showing the surface of a matte coating film made of a paint compounded with a matte corresponding to FIG.

FIG. 6 is an SEM photograph showing the surface of a matte coating film made of a coating material containing a matting agent corresponding to FIG.

FIG. 7 is an SEM photograph showing the surface of a matte coating film made of a coating material containing the corresponding matting agent.

FIG. 8 is an SEM photograph showing the surface of a matte coating film made of a coating material containing a matting agent corresponding to FIG.

9 is an SEM photograph showing a cross section of a coating film corresponding to FIG.

10 is an SEM photograph showing a cross section of a coating film corresponding to FIG.

11 is an SEM photograph showing a cross section of a coating film corresponding to FIG.

12 is an SEM photograph showing a cross section of a coating film corresponding to FIG.

FIG. 13 is a plot of the number of parts added with various matting agents and the 60 ° gloss value.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuru Demura 4-1-21, Nihombashi Muromachi, Chuo-ku, Tokyo Mizusawa Chemical Industry Co., Ltd.

Claims (8)

[Claims] 1. SiO ₂ expressed as a weight ratio based on oxides:
MO = 100: 0 to 50:50 (wherein M represents a Group II metal of the periodic table) of silica or silicate, and is X-ray diffraction amorphous or fine layered crystalline. Yes,
Of the particles in clear spherical individual particles independent long diameter (D _L) and the minor axis (D _S) of the ratio (D _S / D _L) sphericity which is expressed by 0.8 to 1.0 When the particles are 80% or more, the formula (1) D ₂₅ / D ₇₅ (1) In the formula, D ₂₅ represents the particle size of 25% value of the volume-based cumulative particle size distribution curve by the Coulter counter method, and D ₇₅ is Spherical silica or silicic acid having a sharpness of a particle size distribution defined by representing a particle size of 75% value of 1.2 to 2.0 and a BET specific surface area of 30 to 800 m ² / g. Matting agent for paints consisting of salt particles. 2. The spherical particles are measured by a nitrogen adsorption method,
The matting agent according to claim 1, which is a porous particle having a pore volume distribution peak at a pore radius of 10 to 100 angstroms and a pore volume of 0.5 to 2.0 cc / g. 3. The spherical particles have an oil absorption of 50 to 30.
The matting agent according to claim 1, which is a porous particle in the range of 0 ml / 100 g. 4. The spherical particles have a primary particle size of 1 to 10 μm as determined by scanning electron microscopy and have an apparent density (JIS
The matting agent according to claim 1, which is a porous particle having a K-6220 method of 0.1 to 0.5 g / ml. 5. The matting agent according to claim 1, wherein the spherical silicate particles are made of any one of magnesium phyllosilicate, zinc phyllosilicate, and aluminum zinc phyllosilicate. 6. The spherical silica particles have fine particles of 1 μm or less, other than silica, inside the spherical particles,
The matting agent according to claim 1, wherein the matting agent is contained in an amount of 1 to 30% by weight. 7. A matting coating composition comprising the matting agent according to any one of claims 1 to 6. 8. The following formula (2) GPV = P / 100Pa (2) In the formula, P is the number of g of the matting pigment added per 100 g of the coating resin necessary to satisfy the reflectance of 50% at 60 ° gloss. Where Pa is the loose apparent density of the matte pigment (g / m
l), the matte pigment volume concentration (ml /
8. The matte coating composition according to claim 7, wherein the g resin) is in the range of 0.1 to 0.3.