JP2000044226A - Silane-surface-treated siliceous fine particles, their production and organic resin composition containing same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce silane-surface-treated siliceous fine particles having high dispersibility and low aggregability and to obtain an org. resin compsn. giving a film having good transparency, superior blocking resistance, lubricity and scratch resistance. SOLUTION: These silane-surface-treated siliceous fine particles have 0.01-5 μm particle diameter of primary particles. When an org. compd. which is liq. at room temp. and has 1-40 F/m dielectric constant is mixed with the siliceous fine particles in a weight ratio of 5:1 and the mixture is shaken, the siliceous fine particles are uniformly dispersed in the org. compd. When the siliceous fine particles are dispersed in methanol, the methanol is distilled out of the resultant dispersion with an evaporator under heating and the siliceous fine particles are held at 100 deg.C for 2 hr, the ratio of the amt. of primary particles remaining as primary particles to the amt. of the originally present primary particles is >=20%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to silane surface-treated silica-based fine particles, particularly to silica-based fine particles having high dispersibility and low cohesion, a method for producing the same and an organic resin composition containing the silica-based fine particles. .

[0002]

2. Description of the Related Art As a method for treating a silane surface of silica,
Generally, there are methods such as adhesion to the silica surface by silicone oil treatment and chemical bonding to the silica surface by hexamethyldisilazane treatment. Organic resins, especially
Properties required of the organic resin film include transparency, blocking resistance, slipperiness, and scratch resistance. It has been proposed to add spherical silica fine particles to an organic resin film, and it is described that the transparency of the resulting film is improved (Japanese Patent Laid-Open No. 4-348147).

[0003]

The silica obtained by the above-mentioned surface treatment method has a good degree of hydrophobicity, but various reactive groups such as silanol groups or alkoxy groups remain on the silica surface. It cannot be dispersed in an organic solvent or has high cohesiveness, and silica-based fine particles having high dispersibility and low cohesiveness have been desired. JP 2-1606
No. 13 proposes silica-based fine particles having excellent dispersibility, but this method has a problem that when heated for distilling off the solvent, the primary particle retention is deteriorated. When the spherical silica fine particles disclosed in the above-mentioned JP-A-4-348147 are blended as a component of a relatively low-viscosity liquid thermosetting or ultraviolet-curable resin composition, the specific gravity of the silica fine particles is inorganic. It is large (greater than 2.0) and has a large specific gravity difference from other materials (components) of the composition. In addition, the silica fine particles are easily aggregated due to the polarity or hydrogen bond of the silanol group of the silica fine particles. Alternatively, since the composition is difficult to disperse in a solvent, there is a disadvantage that the composition sediments over time during storage of the composition. Therefore, an object of the present invention is to provide silica-based fine particles having high dispersibility and low cohesion, and a method for producing the same. Another object of the present invention is an organic resin composition having a high dispersibility of silica-based fine particles and its stability over time, and therefore has good transparency, excellent blocking resistance, excellent slip resistance, and scratch resistance. It is to provide an organic resin composition from which a film can be obtained.

[0004]

According to the present invention, there is provided silane surface-treated silica-based fine particles having a primary particle diameter of 0.01 to 5 microns, which satisfies the following conditions (i) and (ii). Is done. (I) When an organic compound which is liquid at room temperature and has a dielectric constant of 1 to 40 F / m and silica-based fine particles are mixed at a weight ratio of 5: 1 and shaken, the silica-based fine particles are mixed with the organic compound. Disperse evenly in it. (Ii) After methanol is distilled off from a dispersion in which the silica-based fine particles are dispersed in methanol by heating with an evaporator,
When kept at a temperature of 100 ° C. for 2 hours, the ratio of the amount of primary particles remaining as primary particles to the amount of primary particles initially present is 20% or more.

Further, according to the present invention, the following method is provided as a method for producing the silane surface-treated silica-based fine particles. (A) R ² SiO _3/2 units (where R ² is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms) is introduced into the surface of the hydrophilic silica fine particles composed of SiO ₂ units, obtaining a hydrophobic silica fine _{^{particles, (B) R 1 3 SiO}} 1/2 units to the surface of the resultant hydrophobic fine silica particles (wherein, R ¹ is a substituted or unsubstituted carbon atoms 1 to the same or different (6 monovalent hydrocarbon groups). A process for producing the above-mentioned silane surface-treated silica-based fine particles, comprising the steps of: According to this method, the particle size is from 0.01 to 5
The present invention provides high-dispersion, low-aggregation hydrophobic silica-based fine particles of micron size. Further, according to the present invention, there is provided an organic resin composition comprising (a) 100 parts by weight of an organic resin and (b) 0.01 to 10 parts by weight of the above-mentioned silane surface-treated silica-based fine particles.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. (A) Step In the method of the present invention, the hydrophilic silica fine particles used as a starting material in the step (A) are not particularly limited. For example, the general formula (I): Si (OR ³ ) ₄ (I) ( However, R ³ is the same or different and is a monofunctional hydrocarbon group having 1 to 6 carbon atoms), a tetrafunctional silane compound or a partial hydrolysis product thereof, or a mixture thereof, is converted into a hydrophilic organic compound containing a basic substance. Hydrolysis in a mixture of solvent and water,
Obtaining a hydrophilic silica fine particle mixed solvent dispersion by condensing, and then preparing a hydrophilic silica fine particle aqueous dispersion by converting the dispersion medium of the hydrophilic silica fine particle mixed solvent dispersion to water. Obtained by the following method. Specific examples of the tetrafunctional silane compound represented by the general formula (I) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, and tetrabutoxysilane. Specific examples of the partial hydrolysis product of the tetrafunctional silane compound represented by the general formula (I) include:
Methyl silicate, ethyl silicate and the like can be mentioned.

The hydrophilic organic solvent is not particularly limited as long as it can dissolve the compound of the formula (I) or a partial hydrolysis product thereof and water. And ketones such as acetone and methyl ethyl ketone, and ethers such as dioxane and tetrahydrofuran. Alcohols are preferable. Examples of the alcohol include an alcohol solvent represented by the general formula (V): R ⁶ OH (V) (where R ⁶ is a monovalent hydrocarbon group having 1 to 6 carbon atoms).
Examples include methanol, ethanol, isopropanol, butanol and the like. As the number of carbon atoms in the alcohol increases, the particle size of the silica fine particles formed increases. Therefore, it is desirable to select the type of alcohol according to the target particle size of the silica fine particles. Examples of the basic substance include ammonia, dimethylamine, diethylamine and the like, with ammonia being preferred. After dissolving a required amount of these basic substances in water, the resulting aqueous solution (basic water) may be mixed with a hydrophilic organic solvent.

The amount of water used at this time is determined by the general formula (I)
It is preferably 0.5 to 5 equivalents to the number of moles of the alkoxy group of the silane compound or its partial hydrolysis product, and the ratio of water to the hydrophilic organic solvent is preferably 0.5 to 10 by weight, The amount of the basic substance is preferably 0.01 to 1 equivalent to the number of moles of the alkoxy group of the silane compound of the general formula (I) or a partial hydrolysis product thereof.

For the hydrolysis and condensation of the tetrafunctional silane compound of the general formula (I), the tetrafunctional silane compound of the general formula (I) is dropped into a mixture of water and a hydrophilic organic solvent containing a basic substance. This is performed by a known method. In order to convert the dispersion medium of the silica fine particle mixed solution dispersion into water, for example, an operation of adding water to the dispersion and distilling off the hydrophilic organic solvent (if necessary, repeating this operation) can be performed. . The amount of water added at this time is 0.1% by weight based on the total amount of the hydrophilic organic solvent used and the amount of alcohol generated.
It is good to use 5 to 2 times, preferably almost 1 time.

The hydrophilic silica fine particles used as a starting material in the step (A) may be a mixed solvent dispersion containing hydrophilic silica fine particles, but water is added to the hydrophilic silica fine particle mixed solvent dispersion to prepare a hydrophilic organic solvent. Since the remaining alkoxy groups are completely hydrolyzed by distilling off and converting to an aqueous dispersion, an aqueous dispersion containing hydrophilic silica fine particles is preferable. More specifically, the step (A) is carried out by, for example, adding an aqueous dispersion or a mixed solvent dispersion containing the hydrophilic silica fine particles to the general formula (II): R ² Si (OR ⁴ ) ₃ (II) , R ² is a substituted or unsubstituted C 1-20 carbon atom
R ⁴ is the same or different and is a monovalent hydrocarbon group having 1 to 6 carbon atoms), a trifunctional silane compound represented by the formula (1), a partial hydrolysis product thereof, or a mixture thereof. The surface of the hydrophilic silica fine particles is treated thereby to obtain an aqueous dispersion of hydrophobic silica fine particles.

Specific examples of the trifunctional silane compound represented by the general formula (II) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane,
Ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, trifluoro Examples include trialkoxysilanes such as propyltrimethoxysilane and heptadecafluorodecyltrimethoxysilane, and their partial hydrolysis products may be used. The addition amount of the trifunctional silane compound represented by the general formula (II) is 1 to 0.001 equivalent, preferably 0.1 to 0. 1 equivalent per 1 mol of SiO ₂ unit of the hydrophilic silica fine particles used.
It is better to use 01 equivalent.

Step (B) The step (B) is more specifically, for example, converting the dispersion medium of the hydrophobic silica fine particle aqueous dispersion from water or a hydrophilic organic solvent, an alcohol mixture to a ketone solvent, A step of obtaining a ketone-based solvent dispersion of hydrophobic silica fine particles;
_{^{I): R 1 3 SiNHSiR 1}} 3 (III) ( where, R ¹ is silazane compound represented by the same or different substituted or unsubstituted monovalent carbon hydrogen group having 1 to 6 carbon atoms), the general formula ( ^{IV): (IV) R 1} 3 SiX ( where, R ¹ is the general formula (III) in the same .X is added an OH group or a monofunctional silane compound represented by the hydrolyzable groups) or a mixture thereof, Triorganosilylating the reactive groups remaining on the surface of the hydrophobic silica fine particles.

To convert the dispersion medium of the aqueous silica fine particle dispersion or the mixed solvent dispersion from water or a hydrophilic organic solvent / alcohol mixture to a ketone-based solvent, add a ketone-based solvent to the dispersion and add water or hydrophilic organic solvent. It can be carried out by an operation of distilling off the solvent / alcohol mixture (this operation is repeated as necessary). The amount of the ketone solvent added at this time is 0.5 to 5 times, preferably 1 to 2 times the weight ratio of the hydrophilic silica fine particles used. Specific examples of the ketone solvent used here include methyl ethyl ketone, methyl isobutyl ketone, acetylacetone and the like, and preferably methyl isobutyl ketone.

Specific examples of the silazane compound represented by the general formula (III) include hexamethyldisilazane. Specific examples of the monofunctional silane compound represented by the general formula (IV) include trimethylsilanol and triethyl. Monosilanol compounds such as silanol, trichlorochlorosilane, monochlorosilane such as triethylchlorosilane,
Monoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane; monoaminosilanes such as trimethylsilyldimethylamine and trimethylsilyldiethylamine; and monoacyloxysilanes such as trimethylacetoxysilane are exemplified. The amount of these used is 0.1 mol with respect to the number of moles of the SiO ₂ unit of the hydrophilic silica fine particles used.
It is good to use -0.5 equivalent, preferably 0.2-0.3 equivalent.

As described above, the silica fine particles composed of SiO ₂ units are _converted into R ² SiO _3/2 units (where R ² is represented by the general formula (I)
Were coated with the same) to I), the reactive groups remaining on the surface of the particles R ¹ ₃ SiO _1/2 units (wherein, R ¹ is blocked by the formula (III) in the same), the particle size is 0 .01-5
Microdispersed, preferably 0.01 to 1 micron, highly dispersible, low-agglomerated silica-based fine particles are obtained. The silica-based fine particles may be taken out as a powder by a conventional method, or may be obtained as a dispersion by adding an organic compound after the reaction with silazane.

Organic Resin Composition The organic resin used in the organic resin composition of the present invention may be a thermoplastic resin or a curable resin. Examples of the thermoplastic resin include polyolefins such as polypropylene and polyethylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyamides such as nylon 6 and nylon 66. Further, as the curable resin composition, for example, an epoxy resin composition,
Examples include a thermosetting resin composition such as an unsaturated polyester resin composition, an ultraviolet curable resin composition such as an epoxy acrylate resin composition, and a urethane acrylate resin composition.

The silane surface-treated silica-based fine particles of the component (b) are highly hydrophobized, so that they are easily dispersed in various organic solvents and organic resins, and adversely affect the slipperiness and blocking resistance of the resin surface. Since there is almost no silanol group present on the particle surface, good results can be obtained for the objects and effects of the present invention. The particle size of the fine particles is preferably 0.01 to 5 μm because the resin film surface has good slipperiness, good blocking resistance and good transparency, and sedimentation does not easily occur in the uncured resin composition over time. Preferably
0.05-1 μm is more preferable. The blending amount of the fine particles of the component (b) is usually based on 100 parts by weight of the organic resin.
It is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight. It is easy for those skilled in the art to determine a more suitable compounding amount depending on the type of the resin within such a range. In general, if the amount is too small, the effect of improving the slipperiness and blocking resistance of the film tends to decrease. If the amount is too large, the transparency and strength of the obtained resin film tend to decrease.

The organic resin composition of the present invention contains
(a), in addition to the component (b), if necessary, antioxidants, stabilizers such as ultraviolet absorbers, processing aids, coloring agents, antistatic agents,
Lubricants and the like may be added and blended within a range that does not impair the effects of the present invention. In order to mix the silane surface-treated silica-based fine particles with the organic resin, a known method may be used.
A mixer such as a Henschel mixer, a V-type blender, a ribbon blender, and a grinder may be used. Also,
When the composition has a low viscosity, a predetermined amount of each component may be uniformly mixed using a kneader mixer, a butterfly mixer, or a mixer using a usual propeller stirrer.
Thereby, the composition of the present invention is obtained. A film can be formed from this composition by a known method, such as a T-die method, a circular die method, or a biaxial stretching method. When the composition is a low-viscosity liquid, a transfer method,
What is necessary is just to form into a film by a coating method etc., and to harden.

[0019]

The present invention will be described in detail below with reference to examples and comparative examples. Example 1 (1) 623.7 g of methanol and 41.4 of water were placed in a 3-liter glass reactor equipped with a stirrer, a dropping funnel and a thermometer.
g and 49.8 g of 28% aqueous ammonia were added and mixed. The solution was adjusted to 35 ° C., and 1163.7 g of tetramethoxysilane and 418.1 g of 5.4% aqueous ammonia were simultaneously added with stirring, and the former was added dropwise over 6 hours, and the latter over 4 hours. Stirring was continued for 0.5 hour after the addition of tetramethoxysilane to carry out hydrolysis to obtain a suspension of silica fine particles. An ester adapter and a condenser were attached to the glass reactor, and the mixture was heated to 60 to 70 ° C., and after 649 g of methanol was distilled off, 1600 g of water was added.
0 g was distilled off to obtain an aqueous suspension of silica fine particles. (2) 115.8 g of methyltrimethoxysilane (based on the number of moles of tetramethoxysilane) was added to this aqueous suspension at room temperature.
0.1 equivalent) and 46.6 g of 5.4% ammonia water were added dropwise over 0.5 hours, and after the addition, the mixture was stirred for 12 hours to treat the surface of the silica fine particles. (3) After 1000 g of methyl isobutyl ketone was added to the dispersion thus obtained, the mixture was heated to 80 to 110 ° C. and 1336 g of methanol water was distilled off over 11 hours. 357.6 g of hexamethyldisilazane was added to the obtained dispersion at room temperature.
Was added, and the mixture was heated to 120 ° C. and reacted for 3 hours to trimethylsilyl the silica fine particles. Thereafter, the solvent was distilled off under reduced pressure to obtain 477 g of silane surface-treated silica.

The following tests were carried out on the obtained silane surface-treated silica. [Dispersibility test] Fine particles were added to a liquid organic compound at room temperature in a weight ratio of 5: 1, mixed by shaking using a shaker for 30 minutes, and the dispersion state of the fine particles was visually observed. I do. When the total amount of the fine particles is dispersed and the whole is uniform in the form of a slurry: ；: When the entire amount of the fine particles is wet with the organic compound, but partially not dispersed in the organic compound, and when the uniform amount is uneven, the fine particles are wet. The results are shown in Table 3 where x is not mixed. [Aggregation Acceleration Test] (1) Fine particles are added to methanol at a weight ratio of 5: 1, and shaken using a shaker for 30 minutes. The particle size distribution of the fine particles treated as described above is measured by a laser diffraction scattering type particle size distribution analyzer (LA910, Horiba, Ltd.). (2) Next, after methanol is distilled off from the fine particle dispersion obtained in (1) by heating with an evaporator, the mixture is kept at a temperature of 100 ° C. for 2 hours. After adding the fine particles thus treated to methanol and shaking for 30 minutes using a shaking machine,
The particle size distribution is measured as described above. Based on the particle size distribution obtained in (1), the ratio of the residual amount of the primary particles is determined. Was. The primary particle diameter is confirmed in advance by observation with an electron microscope. The results are shown in Table 3.

[Silicone Viscosity Test] The viscosity of a sample obtained by adding and dispersing 10 g of silica fine particles to 190 g of dimethyl silicone oil (viscosity of 1000 cSt / 25 ° C.) was measured using a BM type rotational viscometer at a rotational speed of 60 rpm. It was measured. The results are shown in Table 3. [Fluidity test] Styrene-acryl (7
0:30) pulverized copolymer (particle size 5-20 microns)
1 g of silica fine particles was added to 100 g, and the fluidity of the pulverized copolymer was examined. The results are shown in Table 3.

Examples 2 to 7 The hydrolysis temperature, the amount of water added, the amount of 5.4% ammonia water added dropwise and its amount, the methyltrimethoxysilane dropwise addition method, its amount, and the amount of methyl isobutyl ketone were as shown in Table 1. A silane surface-treated silica was obtained in the same manner as in Example 1 except for the above. In addition, in Example 5, the methanol distillation operation was not performed. The same test as in Example 1 was performed on the obtained silica fine particles. Table 3 shows the results.

Comparative Example 1 Methyltrimethoxysilane and 5.
An attempt was made to produce hydrophobic silica in the same manner as in Example 1 except that the step of treating the silica fine particles with 4% aqueous ammonia was omitted. As a result, the dispersion of the silica fine particles solidified when water was distilled off. Comparative Example 2 Silane surface-treated silica was obtained in the same manner as in Example 1 except that the step of trimethylsilylation of silica fine particles using hexamethyldisilazane in Example 1 was omitted. Comparative Example 3 Silane surface-treated silica was obtained in the same manner as in Example 1, except that a mixture consisting of 1000 parts by weight of water and 1000 parts by weight of methyl isobutyl ketone was used instead of water in Example 1. Using the silane surface-treated silica obtained in Comparative Examples 2 and 3, a dispersibility test, an aggregation promotion test, a silicone viscosity test, and a fluidity test were performed in the same manner as in Example 1, and the results are shown in Table 4. Comparative Examples 4 to 7 Tests were conducted in the same manner as in Example 1 using commercially available silane surface-treated silica, and the results are shown in Table 4.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3] Note: MIBK: methyl isobutyl ketone, THF: tetrahydrofuran, D ₅ : decamethylcyclopentasiloxane

[0027]

[Table 4] Note) Nipsil SS50F: trade name of Nippon Silica Co., Ltd., silica obtained by treating the surface of a precipitated silica with an organosilicon compound. Nipsil SS10: trade name of Nippon Silica Co., Ltd., silica obtained by treating the surface of a precipitated silica with (CH ₃ ) ₂ SiO _2/2 units. Erosil R972: trade name, manufactured by Nippon Aerosil Co., Ltd. A silica obtained by treating the surface of fumed silica with (CH ₃ ) ₂ SiO _2/2 units. Musil 130A: a product of Shin-Etsu Chemical Co., Ltd., a fumed silica surface treated with CH ₃ SiO _3/2 units.

Example 8 T-die molding polypropylene resin Noblen FL-20
0 (melt flow rate: 8 g / 10 min) (trade name, manufactured by Mitsui Toatsu Chemicals, Inc.) was mixed with 0.5 part by weight of the silane surface-treated silica-based fine particles obtained in Example 1 and uniformly mixed. The obtained mixture was extruded at 250 ° C. by a single screw extruder having a diameter of 25 mm, and pelletized by a pelletizer. The obtained pellets were further extruded with a T-die at 250 ° C. using a 20 mm diameter single screw extruder to obtain a
mm of film was obtained. The following properties were evaluated for the obtained film.

[Transparency] Ten films were stacked, and the total light transmittance was measured. [Blocking resistance] Two films are stacked horizontally, and the upper and lower sides are sandwiched between two glass plates, and one film is placed on the upper glass plate.
A load of 00 g / cm ² was applied and left at room temperature for 24 hours.
Thereafter, the upper glass plate was taken out, and the two films were cut into 5 cm × 5 cm while being overlapped to prepare a sample. At the overlapped end of the sample, the two films were pulled in opposite directions, and the force (g) required for peeling was measured and used as an index of blocking resistance. The smaller the force required for peeling, the higher the blocking resistance. [Slippery] ASTM D
It was measured according to -1894. Table 5 shows the results. Examples 9 to 12 Films were obtained in the same manner as in Example 8 except that the silica-based fine particles used and the compounding amounts thereof were changed as shown in Table 5,
Various properties were similarly evaluated. Table 5 shows the results.

[0030]

[Table 5]

Comparative Examples 8 to 14 Films were obtained in the same manner as in Example 8 except that the silica-based fine particles and the content thereof were changed as shown in Table 6, and various characteristics were evaluated. Table 6 shows the results. The silicon dioxide particles used in Comparative Example 14 were Admafine SO-C5
(Trade name, manufactured by Admatech, average particle size 2 μm, particle size distribution 0.1-5 μm).

[0032]

[Table 6]

Examples 13 to 16 Polytetramethylene ether glycol having a number average molecular weight of 2,000 (trade name: PTM, manufactured by Mitsubishi Kasei Kogyo Co., Ltd.)
G-2000) 150 g, polytetramethylene ether glycol having a number average molecular weight of 1,000 (manufactured by Mitsubishi Kasei Kogyo Co., Ltd., trade name: PTMG-1,000) 150 g,
31.6 g of neopentyl glycol and 175.4 g of 2,4-tolylene diisocyanate were charged in a reaction vessel, and the mixture was reacted at a temperature of 60 to 70 ° C. for 6 hours. The isocyanated reaction mixture thus obtained was cooled to about 40 ° C. 0.15 g of tert-butylhydroxytoluene and 0.05 g of dibutyltin laurate were added thereto.
8 g, and 2-hydroxyethyl acrylate 11
After adding 9.3 g, the resulting mixture is brought to 60-70 ° C.
And reacted for 2 hours to obtain a urethane acrylate oligomer. 55 parts by weight of this urethane oligomer, 15 parts by weight of tricyclodecane dimethanol diacrylate (trade name: SA-1002, manufactured by Mitsubishi Kasei Kogyo Co., Ltd.), bisphenol A-EO modified diacrylate (trade name, manufactured by Toa Gosei Co., Ltd.) : M-210) 10 parts by weight, 10 parts by weight of N-vinylpyrrolidone, 10 parts by weight of isophoronyl acrylate, and 3 parts by weight of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator, and a UV-curable urethane acrylate resin A composition was prepared.

100 parts by weight of the ultraviolet-curable urethane acrylate resin composition prepared above were mixed and mixed with silica-based fine particles shown in Table 7 in the amounts (parts by weight) shown in Table 7;
Further, the mixture was kneaded twice with a three-roll mill and uniformly mixed.
The obtained resin composition is applied on a glass plate to a thickness of 30 to 50 μm, and the obtained coating film is coated with 200 mJ / cm ² (wavelength 3
50 nm) to cure by irradiating with ultraviolet rays, thickness 50 μm
A cured film was obtained. The characteristics of the obtained film were evaluated by the following methods.

Evaluation of Properties [Slidability] The cured film was treated at 25 ° C. and 50% relative humidity for 24 hours.
After adjusting the time condition, the coefficient of friction between
Measured according to 1894. [Blocking resistance] Two cured films cut to 5 cm x 5 cm are placed horizontally on top of each other and sandwiched between two glass plates. A 100 g load is placed on the upper glass plate and left at room temperature for 24 hours. did. Thereafter, the film was removed from the glass plate. At the end of the superposed films, the two films were pulled in opposite directions with a force of 10 g, and the degree of peeling or adhesion of the films was evaluated according to the following criteria. :: peels off easily. ×: Adhered. [Transparency] A cured film having a thickness of 50 μm was prepared by the above method, and when the film was seen through the naked eye, it was determined whether the other side of the film could be seen through and evaluated. ○: See through. ×: Invisible. [Precipitation] Put the resin composition before curing in a glass bottle,
After standing at 30 ° C. for 30 days, the degree of settling of the silica-based fine particles was visually observed. :: No sedimentation was observed. ×: Sedimentation was observed, and separation into two layers was also observed. Table 7 shows the results.

[0036]

[Table 7]

Comparative Examples 15 to 18 Films were obtained in the same manner as in Examples 13 to 16 except that the silica-based fine particles and the compounding amounts thereof were changed as shown in Table 8, and various characteristics were similarly evaluated. Table 8 shows the results. The silicon dioxide particles used in Comparative Example 14 had been surface-treated as described below. Admafine SO-C5 (trade name, manufactured by Admatech, average particle size 2)
(μm, particle size distribution: 0.1 to 5 μm) 100 parts by weight and 1 part by weight of ion-exchanged water were mixed by a mixer and heat-treated at 60 ° C. for 24 hours. The treated mixture was cooled to room temperature, and after adding and mixing 2 parts by weight of hexamethylsilazane, the mixture was allowed to stand at room temperature for 24 hours. Thereafter, heat treatment was performed at 120 ° C. for 24 hours to obtain surface-treated silicon dioxide particles.

[0038]

[Table 8]

Examples 17 to 20 Thermosetting one-pack type epoxy resin (Adeka Opton KT-970, manufactured by Asahi Denka Kogyo KK, viscosity 7300 cP / 25)
C.) 100 parts by weight of the silica-based fine particles shown in Table 9 were blended in the amounts (parts by weight) shown in Table 9 and mixed, further kneaded twice with a three-roll mill, and uniformly mixed. The obtained resin composition was applied on an aluminum plate and a glass plate having a thickness of 0.2 mm to a thickness of 30 to 50 μm, and heated at 130 ° C. for 2 hours to form on the aluminum plate and the glass plate. A cured film was obtained. The following properties were evaluated for the obtained film. [Slidability] 25 films formed on aluminum plate
After conditioning for 24 hours at 50 ° C. and a relative humidity of 50%, the coefficient of friction between the films was measured according to ASTM D1894. [Blocking resistance] Two cured films cut to 5 cm x 5 cm are placed horizontally on top of each other and sandwiched between two glass plates. A 100 g load is placed on the upper glass plate and left at room temperature for 24 hours. did. Thereafter, the film was removed from the glass plate. At the end of the superposed films, the two films were pulled in opposite directions with a force of 10 g, and the degree of peeling or adhesion of the films was evaluated according to the following criteria. :: peels off easily. ×: Adhered. [Transparency] A film having a thickness of 200 to 200
When a cured film having a thickness of 300 μm was prepared and viewed with the naked eye, the evaluation was made based on whether or not the other side of the film could be seen through. ○: See through. ×: Invisible. [Precipitation] Put the resin composition before curing in a glass bottle,
After standing at 30 ° C. for 30 days, the degree of sedimentation was visually observed. :: No sedimentation was observed. ×: Sedimentation was observed, and separation into two layers was also observed. Table 9 shows the results.

[0040]

[Table 9]

Comparative Examples 19 to 22 Cured films were obtained in the same manner as in Examples 17 to 20, except that the silica-based fine particles and the amount thereof were changed as shown in Table 10, and various properties were evaluated in the same manner. Table 10 shows the results. The silicon dioxide particles used in Comparative Example 22 were:
The surface was treated as described below. 100 parts by weight of Admafine SO-C5 (trade name, manufactured by Admatech Co., Ltd., average particle size: 2 μm, particle size distribution: 0.1 to 5 μm) and 1 part by weight of ion-exchanged water are mixed by a mixer.
Heat treatment was performed for 4 hours. The treated mixture was cooled to room temperature, 2 parts by weight of hexamethyldisilazane was added and mixed, and then left at room temperature for 24 hours. Further, heat treatment was performed at 120 ° C. for 24 hours to obtain surface-treated silicon dioxide particles.

[0042]

[Table 10]

[0043]

As described above, the silane surface-treated silica fine particles obtained by the present invention have high dispersibility and low agglomeration, which have never been obtained before. These silica-based fine particles are used to improve the properties of various rubbers and synthetic fats (slipperiness, abrasion resistance, lubricity, blocking prevention,
(Flexibility), improved properties of paints and ink coatings, lubricity and water repellency imparted to cosmetics, abrasive particles for abrasives, powdered resin, etc., can be suitably used as a fluidizing agent for various powders. . In particular, the organic resin composition of the present invention is hardly settled over time because of the use of the above-described highly dispersible silica-based fine particles, and thus has good transparency and excellent blocking resistance, A film having slipperiness and scratch resistance is obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09C 3/12 C09C 3/12

Claims (8)

[Claims] 1. Silane-treated silica-based fine particles having a primary particle size of 0.01 to 5 microns satisfying the following conditions (i) and (ii): (i) liquid at room temperature and having a dielectric constant Is mixed at a weight ratio of 5 to 1 with an organic compound having a particle size of 1 to 40 F / m, and the silica-based fine particles are uniformly dispersed in the organic compound. (Ii) After methanol is distilled off from a dispersion in which the silica-based fine particles are dispersed in methanol by heating with an evaporator,
When kept at a temperature of 100 ° C. for 2 hours, the ratio of the amount of primary particles remaining as primary particles to the amount of primary particles initially present is 20% or more. Wherein (A) the surface of R ² SiO _3/2 units of the hydrophilic silica fine particles comprising SiO ₂ units (wherein, R ² is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms ) was introduced, and obtaining a hydrophobic silica fine particles, (B) obtained hydrophobic silica surface to R ¹ ₃ SiO _1/2 units of microparticles (wherein, R ¹ is a substituted or unsubstituted identical or different 2. A method for producing silica-based fine particles treated with a silane surface according to claim 1, comprising a step of introducing a monovalent hydrocarbon group having 1 to 6 carbon atoms). 3. The hydrophilic silica fine particles used in the step (A) are represented by the general formula (I): Si (OR ³ ) ₄ (I) (where R ³ is the same or different and has 1 to 6 carbon atoms). Hydrolyzing a tetrafunctional silane compound represented by the formula (1) or a partial hydrolysis product thereof or a mixture thereof in a mixture of a hydrophilic organic solvent containing a basic substance and water;
Obtaining a hydrophilic silica fine particle mixed solvent dispersion by condensing, and then preparing a hydrophilic silica fine particle aqueous dispersion by converting the dispersion medium of the hydrophilic silica fine particle mixed solvent dispersion to water. The production method according to claim 2, which is obtained by the following method. 4. The hydrophilic organic solvent is an alcohol solvent represented by the general formula (V): R ⁶ OH (V) (where R ⁶ is a monovalent hydrocarbon group having 1 to 6 carbon atoms). A method for producing the silica-based fine particles according to claim 3. 5. The method according to claim 3, wherein the basic substance is ammonia. 6. The method according to claim 1, wherein the step (A) comprises adding an aqueous dispersion or a mixed solvent dispersion containing the hydrophilic silica fine particles to a dispersion of the general formula (I)
I): R ² Si (OR ⁴ ) ₃ (II) (where R ² is a substituted or unsubstituted carbon atom having 1 to 20 carbon atoms)
R ⁴ is the same or different and is a monovalent hydrocarbon group having 1 to 6 carbon atoms), a trifunctional silane compound represented by the formula (1), a partial hydrolysis product thereof, or a mixture thereof. The surface of the hydrophilic silica fine particles is treated thereby, to obtain an aqueous dispersion of hydrophobic silica fine particles, and the step (B) converts the dispersion medium of the aqueous dispersion of hydrophobic silica fine particles into a ketone-based solvent, a step of obtaining a hydrophobic silica fine particles ketone solvent dispersion, hydrophobic silica microparticles ketone solvent dispersion into the general formula _{^{(III): R 1 3 SiNHSiR}} 1 3 (III) ( where, R ¹ is identical or different silazane compound represented by a substituted or unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms), the general formula _{^{(IV): R 1 3 SiX}} (IV) ( where, R ¹ is the general formula (III) same as X is an OH group or a hydrolyzable group) 3. The method for producing silica-based fine particles according to claim 2, comprising: adding a monofunctional silane compound or a mixture thereof, and triorganosilylating a reactive group remaining on the surface of the hydrophobic silica fine particles. . 7. The method according to claim 6, wherein the ketone solvent is methyl isobutyl ketone. 8. A silica-based fine particle having a silane surface treatment according to claim 1, wherein (a) 100 parts by weight of an organic resin and (b) 0.01% by weight of the silica-based fine particles.
An organic resin composition comprising from 10 to 10 parts by weight.