JP2003226814A - Method for producing curable composition containing scaly silica particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a curable composition which comprises scaly silica particles and a polymer and does not precipitate the scaly particles, even when stored for a long period. <P>SOLUTION: This method for producing the curable composition comprises mixing a slurry containing 0.1 to 10 wt.% of scaly silica particles each having a shape obtained by laminating the primary particles of flaky silica with an aqueous emulsion containing the polymer in an amount of ≥20 wt.%. The curable composition is suitable for floor polishing uses. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a curable composition containing scaly silica particles.

[0002]

2. Description of the Related Art In Japanese Patent Laid-Open No. 2001-163613, primary particles of flaky silica are substantially composed of scaly silica particles formed by stacking a plurality of sheets in which planes are oriented parallel to each other and are independent of each other. Disclosed is an aqueous curable composition containing existing scaly silica particles having a laminated particle morphology and a film-forming organic polymer substance. This curable composition is a particle binder (binder), a coating / coating agent for exterior or interior of buildings and structures, a coating / coating agent having a thermal function (heat resistance, heat insulation, fire prevention / flame retardancy, etc.), Paints / coating agents that have optical functions (UV shielding, light selective absorption, light emission / fluorescence, etc.), paints that have electrical / magnetic functions (electrical insulation, conductivity, antistatic, electromagnetic wave absorption, electromagnetic wave shielding, etc.) Coating agent,
Coating materials with adsorption functions (water adsorption / desorption, gas adsorption / desorption, thin-layer chromatography, etc.), coating agents and particle binders (binders) for adsorbent particles, coatings with catalytic functions (photocatalyst, etc.) Coating agents and particle binders for catalyst particles, paints with biological functions (antibacterial, antifungal, ship bottom antifouling, aquatic nutrition, cell culture, etc.), coating agents, aroma and deodorant paints. It is useful for various applications such as coating agents. However, the storage stability of the curable composition disclosed in JP 2001-163613 was not at a satisfactory level.

[0003]

The above curable composition is used as a coating composition for the outer wall of structures such as buildings and bridges, and a floor polish composition for floors of commercial facilities such as supermarkets, department stores and hotels. When used as a product, the curable composition is usually 100 to 2 for commercial use.
It is filled in a container of about 00L in a drum and stored in a warehouse or transported by sea. In the meantime, when the scaly silica aggregate particles in the composition settled on the bottom of the container, there was a problem that the container had to be shaken again to redisperse the particles. It is an object of the present invention to provide a method for producing an aqueous cured composition containing scaly silica particles and a polymeric substance and having high storage stability.

[0004]

The present invention provides a scaly silica particle having a form in which primary particles of flaky silica are laminated in an amount of 0.1.
It is a method for producing a curable composition, which comprises mixing a slurry containing 10 to 10 mass% with an aqueous emulsion containing 20 mass% or more of a polymer substance.

In the present invention, in order to obtain a curable composition having high dispersibility and high storage stability, a slurry containing scaly silica particles in the form of laminated primary particles of flaky silica (hereinafter referred to as "slurry") , Simply referred to as slurry) and an aqueous emulsion containing a polymer substance (hereinafter simply referred to as emulsion), the concentration of the scaly silica particles in the slurry needs to be 0.1 to 10% by mass. is there. If the concentration of scaly silica in the slurry is lower than 0.1% by mass, the concentration of the curable composition obtained will be low, and it will be unsuitable as a coating agent, adhesive, etc. If it is more than 10% by mass, the scaly silica particles may remain aggregated, so that when the slurry and the emulsion are mixed, they are not uniformly dispersed, and the curable composition exhibits high storage stability. Not preferable. The slurry concentration is preferably 1 to 7% by mass, and particularly preferably 2 to 4.5% by mass. The dispersion medium of the slurry is preferably water.

In the present invention, when the slurry and the emulsion are mixed, the concentration of the polymer substance in the emulsion is 20.
It must be at least mass%. If it is lower than 20% by mass, the concentration of the polymer substance in the curable composition obtained by mixing with the slurry becomes too low, and the drying time becomes long when actually applied to the floor surface as a floor polish liquid. Not preferable. Further, the workability is deteriorated such that the coating layer becomes thin and the number of times of repeated coating increases, which is not preferable. It is preferably 25% by mass or more, more preferably 30% by mass or more.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION (Production of Aggregate Particles of Scale-like Silica) The scale-like silica particles used in the present invention are produced by crushing and dispersing the scale-like silica aggregate particles produced as follows. Preferably. The scaly silica aggregate particles are
It is a particle in which scaly silica particles having a gap formed by individual scaly silica particles agglomerating and irregularly overlapping each other are agglomerated.

Specifically, the starting material silica is hydrothermally treated in the presence of an alkali metal salt, and the primary particles of the flaky silica are oriented parallel to each other so that the flaky silica particles are agglomerated. It is preferable to form scaly silica agglomerated particles having voids formed by irregularly overlapping each other. In the present invention, examples of the form of silica as a starting material include silica sol, silica hydrogel, and hydrous silicic acid. Below, each example when using the said silica is shown.

(A) When the silica sol is used as a starting material, it is preferable to use a silica sol containing a specific amount of silica and an alkali metal. As silica sol, silica / alkali metal molar ratio (SiO ₂ / Me ₂ O, where M
e represents an alkali metal such as Li, Na or K. same as below. ) Is 1.0 to 3.4, and an alkali metal silicate aqueous solution is dealkalized by an ion exchange resin method, an electrodialysis method or the like, and silica sol is preferably used. As the alkali metal silicate aqueous solution, for example, water glass appropriately diluted with water is preferable.

Silica / alkali metal molar ratio of silica sol
The range of (SiO ₂ / Me ₂ O) is preferably 3.5 to 20, and particularly preferably 4.5 to 18. Further, the SiO ₂ concentration in the silica sol is preferably 2 to 20% by mass,
3 to 15 mass% is particularly preferable.

The average particle size of silica in the silica sol is 1 to
100 nm is preferred. If the average particle size is more than 100 nm, the stability of the silica sol will decrease, which is not preferable. Among the silica sols, those having an average particle size of 1 to 20 nm or less, which is called activated silicic acid, are particularly preferable.

As described above, silica sol is used as a starting material, and this is heated in a heating and pressure vessel such as an autoclave for hydrothermal treatment to produce the scaly silica aggregate particles in the present invention. The form of the autoclave is not particularly limited, but any autoclave provided with at least a heating means, a stirring means, and preferably a temperature measuring means may be used. Since the silica sol is hydrothermally treated,
The silica concentration can also be adjusted to a desired range by adding purified water such as distilled water or ion-exchanged water prior to charging the autoclave.

The hydrothermal treatment is preferably carried out at a temperature of 150 to 250 ° C. and a temperature of 170 to 220 ° C. in order to increase the reaction rate and reduce the progress of crystallization.
It is particularly preferable to carry out in the range of The hydrothermal treatment time may vary depending on the hydrothermal treatment temperature, the presence or absence of seed crystal addition, etc., but is usually 3 to 50 hours, preferably 3 to 4 hours.
Particularly preferred is 0 hours, most preferred is 5 to 25 hours.

In order to efficiently proceed the hydrothermal treatment and shorten the treatment time, its addition is not essential, but about 0.001 to 1% by mass of seed crystal is added to the charged amount of the raw material silica sol. It is more preferable. As the seed crystal, silica-X, silica-Y, or the like can be used as it is or after being appropriately crushed.

After completion of the hydrothermal treatment, the product is taken out from the autoclave, filtered and washed with water. Particles after washing with water,
The pH of the water slurry of 10% by mass is preferably 5 to 9, and more preferably 6 to 8.

(B) When silica hydrogel is used as a starting material, crystals of quartz or the like are produced by reacting scaly silica aggregate particles such as silica-X and silica-Y at a lower temperature for a shorter time. It is possible to manufacture with high yield without performing the above. The silica hydrogel is preferably a particulate silica hydrogel, and its particle shape may be spherical or amorphous, and its granulation method can be appropriately selected.

For example, in the case of a spherical silica hydrogel, the silica hydrosol can be produced by solidifying it into a spherical shape in a medium such as petroleum, but by mixing an aqueous solution of alkali metal silicate and an aqueous solution of mineral acid. It is preferable that the silica sol is produced in a short time and at the same time, the silica sol is released into a gas medium and gelled in a gas.

That is, the alkali metal silicate aqueous solution and the mineral acid aqueous solution are introduced into a container having a discharge port through separate inlets, and are instantaneously and uniformly mixed to obtain 1 in terms of SiO ₂ concentration.
A silica sol having a pH of 7 to 9 at 30 g / L or more is produced, and this is released from the above-mentioned outlet into a gaseous medium such as air and gelated in the air. It is dropped in a aging tank filled with water and aged for several minutes to several tens of minutes, and an acid is added and washed with water to obtain a spherical silica hydrogel.

The silica hydrogel is a transparent and elastic spherical particle having an average particle size of about ₂ to 10 mm, which has a uniform particle size, and contains about 4 times as much water as SiO ₂ by weight. In some cases, S in silica hydrogel
The iO ₂ concentration is preferably 15 to 75 mass%.

Using such a silica hydrogel as a starting material, hydrothermal treatment is carried out by heating in a heating pressure vessel such as an autoclave in the same manner as in the case of using the above silica sol to obtain the scaly silica aggregate particles in the present invention. To generate. The spherical silica hydrogel may be used as it is, but may be pulverized or coarsely pulverized to have a particle size of about 0.1 to 6 mm.

In order to hydrothermally treat the silica hydrogel,
When charged in an autoclave, the concentration of silica hydrogel can be adjusted to a desired range by adding purified water such as distilled water or ion-exchanged water. The total silica concentration in the treatment liquid in the autoclave is selected in consideration of stirring efficiency, crystal growth rate, yield, etc., but normally, SiO ₂ is preferably 1 to 30% by mass based on the total amount of the raw material charged. ~ 20
Mass% is particularly preferred. Here, the total silica concentration in the treatment liquid means the total silica concentration in the system, and not only silica in the silica hydrogel but also sodium silicate or the like when sodium silicate or the like is used as an alkali metal salt. This is the value including silica introduced into the system.

In the hydrothermal treatment, an alkali metal salt is allowed to coexist in the silica hydrogel, the pH of the treatment liquid is adjusted to the alkali side, and the solubility of silica is appropriately increased.
It is possible to increase the crystallization rate based on the aging of the wald and accelerate the conversion of the silica hydrogel into silica-X or the like.

Here, the alkali metal salt means an alkali metal hydroxide, an alkali silicate, an alkali metal carbonate or the like. Li, Na or K is preferable as the alkali metal. The pH of the system is preferably pH 7 or higher,
A pH of 8 to 13 is particularly preferable, and a pH of 9 to 12.5 is the most preferable.

When the amount of the preferred alkali metal relative to the total amount of the alkali metal and silica is expressed by the silica / alkali metal molar ratio (SiO ₂ / Me ₂ O), it is in the range of 4 to 15, and 7 to 13. Ranges are particularly preferred.

The hydrothermal treatment is preferably carried out in the temperature range of 150 to 220 ° C., particularly preferably 160 to 200 ° C., most preferably 170 to 195 ° C. The necessary hydrothermal treatment time may vary depending on the hydrothermal treatment temperature, the presence or absence of seed crystals, and the like, but is usually 3 to 50 hours, particularly preferably 5 to 40 hours, and preferably 5 to 25 hours. More preferably, about 5 to 12 hours is most preferable.

In order to efficiently proceed the hydrothermal treatment and shorten the treatment time, its addition is not essential, but 0.001 to 1 is added with respect to the amount of the raw material silica hydrogel charged.
It is more preferable to add seed crystals of about mass%. As the seed crystal, it is preferable to use silica-X, silica-Y, or the like as they are or after crushing appropriately as in the method using silica sol.

After completion of the hydrothermal treatment, the hydrothermally treated product is taken out from the autoclave, filtered and washed with water to adjust the pH, as in the method using silica sol.

(C) When hydrous silicic acid is used as a starting material, the scaly silica aggregate particles of the present invention can be synthesized in the same manner as in the silica sol.

(Scene of Flake-Shaped Silica Aggregate Particles) As described above, the cake of the hydrothermal treatment product obtained by hydrothermally treating silica sol, silica hydrogel or hydrous silicic acid is filtered and washed with water to obtain particles. , A particle obtained by observing using a scanning electron microscope (hereinafter abbreviated as “SEM”), where the scaly silica particles have a gap formed by agglomerating and irregularly overlapping individual scaly silica particles. Can be identified.

However, as will be described later, the SEM cannot identify the primary particles that are ultrathin flakes, and the primary particles that are ultrathin flakes are scaly with a plurality of superposed sheets with parallel orientation of the planes. Only silica particles can be identified.

On the other hand, a transmission electron microscope (hereinafter referred to as "TEM")
Is abbreviated. ) Is used, it is possible to identify primary particles which are ultra-thin particles which partially penetrate the electron beam.
It can be identified that the flaky silica secondary particles are the flaky silica particles of the present invention, and the flaky silica primary particles are formed by a plurality of parallel flanks of the flaky silica particles.

It is extremely difficult to separate and separate the primary particles of the flaky silica, which is the constituent unit, from the flaky silica particles one by one. That is, in the layered overlap of the primary particles of flaky silica, the bonding between the layers is extremely strong and completely fused and integrated, and therefore, the flake silica particles of the present invention are no longer more than those of flaky silica. It is difficult to disintegrate into primary particles. In the fine powder of flaky silica particles, the thickness of the primary particles of flaky silica is extremely thin, about 1 to 10 nm. In addition, in the flake-shaped silica particles, there are many portions where the primary particles of the flake-shaped silica are laminated in parallel and regularly, but the gap width is about 1 to 100 nm due to the irregular lamination partially. The existence of the gap is recognized.

(Crushing / Dispersion of Scale-like Silica Aggregate Particles) In the present invention, it is preferable that the scale-like silica agglomerate particles obtained by further aggregating the scale-like silica particles are wet-crushed / dispersed. Thereby, scale-like silica particles can be obtained.

As a device for wet crushing, a wet crushing device (crushing device) such as a wet bead mill of a system of mechanically stirring at high speed using a crushing medium, a wet ball mill, a thin film swivel type high speed mixer, or the like is used. Can be mentioned. In particular, when medium beads such as alumina or zirconia having a diameter of 0.2 to 1 mm are used in the wet bead mill, it is possible to disintegrate and disperse the basic laminated structure of the scaly silica particles so as not to crush and destroy it as much as possible. It is preferable because it is possible.

Further, the cake of the scaly silica aggregate to be wet-milled is diluted with purified water such as distilled water or ion-exchanged water to obtain an appropriate slurry concentration, and then supplied to the wet-milling apparatus.
The slurry concentration is preferably 0.1 to 50% by mass. Considering crushing efficiency and work efficiency due to increase in viscosity, 0.1 to 30 mass% is particularly preferable.

(Scale-like silica particles) Scale-like silica particles are scale-like silica particles in which primary particles of flaky silica are oriented in parallel with each other and face to face, and are present independently of each other. It is preferable that the particles have a laminated structure.

The average particle size of the scaly silica particles is not particularly limited, but is usually preferably 10 to 5000 nm, particularly preferably 100 to 2000 nm.

In the present invention, so-called layered polysilicic acid is most preferable as the primary particles of the flaky silica.
Here, the layered polysilicic acid has a basic structural unit of SiO ₄
It refers to a polysilicic acid having a silicate layer structure consisting only of tetrahedra. Layered polysilicic acid or a salt thereof is, for example, silica-
X, silica-Y, kenyaite, magadiite, macatite, islayite, kanemite, octosilicate, etc., for example, alkali metal in the silicate was ion-exchanged with hydrogen ions by acid treatment of the layered polysilicate. The H type is also included.

As the X-ray diffraction spectrum of the scale-like silica particles, ASTM (American Society for Tes
ting and Materials) registered cards (below,
It is simply called an ASTM card. ) 2θ = 4.9 °, 26.0 °, and 28.3 ° corresponding to the number 16-0380
Corresponding to silica-X or ASTM card number 31-1233 characterized by the main peak of 2θ = 5.6 °, 25.
Silica-Y characterized by major peaks at 8 ° and 28.3 °
Is silica.

In the present invention, both the alkali metal salt type layered polysilicate and the H type layered polysilicate can be used, but when the two are compared, the alkali metal salt type layered polysilicate is , PH is highly alkaline, H
The H-type layered polysilicic acid is particularly preferable because the pH of the layered polysilicic acid is close to neutral.

As the H-type layered polysilicic acid, acidity (SiO ₂ ) measured by a titration method using sulfuric acid, hydrochloric acid, sodium hydroxide, sodium chloride aqueous solution, etc.
The amount of titratable H ⁺ ions is 0.01 to 70 mmol H ⁺ / mol SiO ² per mol.
It is preferably about ₂ , and 0.01 to 50 mmol H ⁺
/ Mol SiO ₂ is particularly preferable, and those having about 0.01 to 20 mmol H ⁺ / mol SiO ₂ are most preferable.

On the other hand, the amount of sodium remaining in the layered polysilicate is preferably about 1 to 27,000 ppm with respect to the mass of the layered polysilicate calculated as SiO _2.
000 ppm is particularly preferable, 1 to 8000 ppm
The degree is the most preferable.

In the present invention, an aqueous emulsion-state polymer substance is added to a slurry containing scaly silica,
A curable composition having high storage stability is produced.

The polymer substance in an aqueous emulsion state used in the present invention is not particularly limited as long as it is an aqueous emulsion of a film forming polymer substance. Among the polymeric substances, organic polymeric substances are preferred. Organic polymer materials include acrylic resin-based, epoxy resin-based, urethane resin-based, styrene resin-based, silicone resin-based, fluororesin-based, vinyl acetate resin-based, vinyl chloride resin-based and At least one homopolymer or copolymer selected from the group consisting of polyester resin systems, or a mixture or complex of two or more thereof is preferable.

As the polymer substance in the water-soluble emulsion state, any particle size can be used, but the average particle size is preferably 1 to 1000 nm, and the average particle size is 10 to 300 n.
m is particularly preferred.

By mixing a slurry containing scaly silica with a polymer substance in an aqueous emulsion state, primary particles of flaky silica which substantially do not contain scaly silica aggregate particles in which scaly silica is aggregated Is a curable composition having a high storage stability in which the scaly silica particles in which the surfaces are oriented parallel to each other and a plurality of which are stacked are highly dispersed.

As a mixing method, any of a turbine type agitator, a high speed shear type agitator and the like can be used. The liquid temperature during mixing is preferably 10 to 80 ° C. If the liquid temperature is too high, the concentration will change due to water evaporation, which is not preferable, and if it is too low, the viscosity or the like will change, which is not preferable.

The ratio of the scale-like silica and the polymer substance in the curable composition in terms of solid content is preferably 1-80% by weight of the scale-like silica based on the total amount, and 5-3.
0% by weight is particularly preferred. If the solid content of the scaly silica is less than 1%, the effect expected for the coating film formed,
That is, it is difficult to exhibit water resistance, acid resistance, alkali resistance, weather resistance, high hardness, or strong adhesion to a substrate, which is not preferable. On the other hand, if the solid content of the scaly silica is larger than the above amount, the viscosity of the mixed solution increases and the work load at the time of forming the coating film increases, which is not practical and is not preferable.

[0049]

EXAMPLES The present invention will be described in detail below with reference to examples. Further, a synthesis example shows a method for producing scaly silica aggregate particles using silica hydrogel as a starting material.

[Synthesis Example 1] (Production of silica tertiary aggregate particles using hydrogel as a starting material) The silica hydrogel as a starting material was prepared as follows using sodium silicate as an alkali source. SiO
₂ / Na ₂ O = 3.0 (molar ratio), SiO ₂ concentration 21.0
2000 ml / m of aqueous sodium silicate solution which is mass%
In, it is introduced into a container equipped with a discharge port, an aqueous solution of sulfuric acid having a sulfuric acid concentration of 20.0 mass% is supplied from another introduction port of this container, and the mixture is instantaneously and uniformly mixed, and then discharged into the air from the discharge port. The flow ratio of the two liquids was adjusted so that the pH of the discharged liquid was 7.5 to 8, and the uniformly mixed silica sol liquid was continuously discharged into the air from the discharge port. The discharged liquid became spherical droplets in the air and gelled in the air while drawing a parabola and staying for about 1 second. A ripening tank filled with water was placed at the dropping point, and the aging tank was dropped here for aging.

After the aging, the pH was adjusted to 6 and further thoroughly washed with water to obtain a silica hydrogel. The obtained silica hydrogel particles have a spherical particle shape and an average particle diameter of 6
It was mm. SiO ₂ in the silica hydrogel particles
The mass ratio of water to mass was 4.55 times, and the residual sodium in the silica hydrogel particles was 110 ppm.
Met.

The silica hydrogel particles were coarsely crushed to an average particle size of 2.5 mm using a double roll crusher and used in a hydrothermal treatment step to form scaly silica aggregate particles.

The silica hydrogel thus obtained was placed in an autoclave (electric heating type, equipped with an anchor type stirring blade) having a volume of 5 L and the total SiO ₂ / Na ₂ O molar ratio in the system was 12.7.
2374 g of silica hydrogel (SiO ₂ 20.00% by mass) having a particle diameter of 2.5 mm and JIS 3
No. Sodium silicate (SiO ₂ 28.75% by mass) 555 g
Was charged, and 1072 g of tap water was added to this, and 210 r
Hydrothermal treatment was performed at 185 ° C. for 9 hours while stirring at pm. The total silica concentration in the system was 15.9 mass% as SiO ₂ . The average particle size of the scaly silica aggregate particles in the slurry was 4.0 μm.

The hydrothermally treated slurry was filtered and washed with a filter cloth type vertical centrifuge (manufactured by Toko Kikai Co., Ltd., trade name TU-18 type) to obtain a water content of 70.0% by mass (solid content). 2000 g of wet cake of silica having a concentration of 30.0 mass% was obtained. The average particle size in this example was measured with a laser diffraction / scattering particle size analyzer (manufactured by Nikkiso Co., Ltd., trade name Microtrac 9320HRA (X100)).

When the morphology of the produced particles was observed by TEM, it was observed that the primary particles of the flaky silica were oriented parallel to each other and the plurality of sheets were overlapped to form scaly silica particles. .

[Example 1 (Example)] To 2000 g of the wet cake obtained in Synthesis Example 1, tap water was added and repulped, and an aqueous sodium hydroxide solution was added to adjust the pH to contain scaly silica agglomerated particles. Slurry (solid content 15% by mass,
4000 g of pH 8.5) was obtained. Next, the obtained slurry was rotated using a medium stirring bead mill (manufactured by Shinmaru Enterprises Co., Ltd., product name Dyno Mill KDL-PILOT A type (vessel capacity 1.4 L, diameter 0.5 mm zirconia beads 70% filled)). Number 3400 rp
The silica agglomerate particles were disintegrated and dispersed by passing once at m and a flow rate of 10 L / h. This operation was repeated 5 times in total to obtain a slurry containing scaly silica particles. The average particle size of the scaly silica particles in the slurry after crushing and dispersing was 1.1 μm.

A part of the obtained slurry was diluted and mixed with tap water to a solid content concentration of 2.84% by mass to obtain 500 g of a slurry containing scaly silica particles. Mixing was performed for 1 minute with a homomixer (8000 rpm).

Slurry 5 containing the scale-like silica particles
Acrylic resin-based aqueous emulsion for floor polish (made by JSP, trade name ACHI)
EVE, resin solid content concentration 27.0 mass%, pH 8.5)
1000 g was added and stirred in a stirring tank equipped with stirring blades to obtain a curable composition.

The resin concentration in the obtained curable composition was 1
8.0% by mass, the concentration of scaly silica particles is 0.9% by mass
And the solid content conversion ratio is resin: scale-like silica particles =
It was 95.0: 5.0. The storage stability of this curable composition in the container was observed in accordance with the method for evaluating the storage stability in the warming defined by JIS K5400. As a result of observing the state of the liquid by keeping still at 35 ° C. for 90 days, no sedimentation and deposition of silica was observed at the bottom of the container.

Next, a glass plate (soda lime glass, 7
(0 mm × 150 mm × 2 mm thickness) is prepared, and the slurry is applied to a glass plate using a # 120 bar coater (manufactured by Eto Kikai Co., Ltd.) by a bar coater coating method (JIS K5400) and dried at room temperature for 24 hours. The test piece was used. The coating amount was 20 g / m ² in terms of solid content. The obtained coating film was evaluated for pencil hardness, cross-cut peeling test and transparency according to JIS K5400, and the results are shown in Table 1.
It was shown to. The transparency of the coating film was shown by using the haze value measured by a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., trade name NPH-2000 type). In addition, the appearance of the coating film was smooth and no cracks were observed.

[0061]

[Table 1]

From Table 1, the pencil scratch value (hardness) and cross-cut peelability evaluation score (adhesion) of the coating film are not deteriorated after storage, and there is no change in the film forming property of the coating film before and after storage. I understand. In addition, since the haze value was not reduced, it was found that the particle morphology of the laminated structure of scaly silica was not destroyed and the particles were oriented in the coating film.

Since the curable composition of this example was used for floor polishing, a heating and storage stability test was further conducted. The curable composition slurry was prepared according to JIS K3920.
The storage stability test (45 ° C., standing for 30 days) under the storage stability accelerating condition of the floor polish test method specified in 1. was tested. In the slurry, no sedimentation and deposition of silica was observed at the bottom of the container.

[Example 2 (Example)] The crushing obtained in Example 1
A part of the slurry containing the scaly silica particles subjected to the dispersion treatment is diluted and mixed with tap water so that the solid content concentration becomes 2.50 mass%, and the slurry 61 containing the scaly silica particles is mixed.
3 g was obtained.

To 613 g of the obtained slurry, 1000 g of an acrylic resin-based aqueous emulsion for floor polishing (manufactured by JSP, trade name PRIMODUAL, resin solid content concentration 29.1% by mass, pH 8.5) was added. Then, the mixture was stirred in a stirring tank equipped with stirring blades to obtain a curable composition.

The resin concentration of the obtained curable composition was 18.
0 mass%, the scale-like silica particle concentration is 0.9 mass%, and the solid content conversion ratio is resin: scale-like silica particles = 9
It was 5.0: 5.0. Similar to Example 1, JIS K3
According to the method specified in 920, the storage stability of the curable composition on heating was observed. No sedimentation of silica was observed at the bottom of the container.

[Example 3 (Example)] The crushing obtained in Example 1
A part of the slurry containing the scaly silica particles subjected to the dispersion treatment is diluted and mixed with tap water so that the solid content concentration becomes 4.25 mass%, and the slurry 8 containing the scaly silica particles is mixed.
89 g were obtained.

To 889 g of the obtained slurry, 1000 g of an acrylic resin-based aqueous emulsion for floor polishing (manufactured by JSP, trade name COMFORT, resin solid content concentration 34.0% by mass, pH 8.5) was added. ,
The curable composition was obtained by stirring in a stirring tank equipped with stirring blades.

The resin concentration in the obtained curable composition was 1
The mass ratio was 8.0 mass%, the flake silica particle concentration was 2.0 mass%, and the solid content conversion ratio was resin: flake silica particles = 9.
It was 0.0: 10.0. Similar to Example 1, JIS K
The warm storage stability of the curable composition was measured by the method specified in 3920. No sedimentation of silica was observed at the bottom of the container.

[Example 4 (Comparative Example)] 63 g of the slurry (solid concentration 15.0% by mass) containing the scaly silica particles obtained in Example 1 was added to an acrylic resin-based aqueous emulsion for floor polish (JS).・ Product name AC manufactured by P.
HIEVE, solid content concentration 18.0 mass%, pH 8.5)
1000 g was added and stirred in a stirring tank equipped with stirring blades to obtain a curable composition.

The resulting cured composition resin concentration was 16.9% by mass, the concentration of scaly silica particles was 0.9%, and the solid content concentration ratio was resin: scale silica particles = 95.
It was 0: 5.0. As in Example 1, the storage stability of the curable composition under heating was observed by the method specified in JIS K 3920. The storage stability of the curable composition was observed. Was recognized by.

[0072]

According to the present invention, an aqueous curable composition containing scaly silica particles having high storage stability (sedimentation-separation resistance) and a polymer substance can be obtained.

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Claims (5)

[Claims] 1. A slurry containing 0.1 to 10% by mass of scaly silica particles in a form in which primary particles of flaky silica are laminated, and an aqueous emulsion containing 20% by mass or more of a polymer substance are mixed. A method for producing a curable composition. 2. The curable composition according to claim 1, wherein the scaly silica particles are scaly silica particles in which primary particles of flaky silica are oriented parallel to each other in a face-to-face direction and a plurality of sheets are stacked. Method. 3. The method for producing a curable composition according to claim 1, wherein the flaky silica primary particles are layered polysilicic acid. 4. The primary particle of the flaky silica is a silica whose main peak in X-ray diffraction analysis corresponds to silica-X or silica-Y. A method for producing a curable composition. 5. The method for producing a curable composition according to claim 1, wherein the curable composition is used for floor polishing.