JP5206919B2 - Method for producing surface-treated inorganic particle powder - Google Patents

Description

  The present invention provides a hydrophobic inorganic particle powder that has excellent hydrophobicity and can maintain excellent hydrophobicity for a long period of time because the hydrophobizing agent is not easily detached from the particle surface.

  At present, inorganic particle powders are used in various applications such as rubber / resin compositions, paints, cosmetics, magnetic recording and printing recording fields, reinforcing agents, coloring agents, filler agents, UV shielding agents, abrasives, imparting electrical conductivity. As an agent or a magnetic material, it is widely used for imparting various properties to various materials.

  It is known that inorganic particle powder is generally hydrophilic and poor in lipophilicity because of the presence of hydroxyl groups and adsorbed moisture on the particle surface. Therefore, when dispersing in an organic medium or kneading into a resin, it is necessary to hydrophobize the particle surface of the inorganic particle powder. From the viewpoint of improving dispersibility, a more hydrophobic material is required. It has been demanded.

  Further, in the recent cosmetics field, highly hydrophobic materials are required in order to prevent makeup collapse due to sweat, sebum, or oils blended in cosmetics.

  Furthermore, since various materials containing the above inorganic particle powder are used in various environments such as high temperature and high humidity or low temperature and low humidity, materials that can maintain stable hydrophobicity for a long period of time in various environments are required. Yes.

  Conventionally, it is known to improve hydrophobicity, fluidity, and the like by mixing inorganic particle powder such as silica and a surface modifier such as silane compound (Patent Documents 1 to 10).

Japanese Patent Laid-Open No. 5-97423 Japanese Patent Laid-Open No. 7-166091 JP 2000-95968 A JP 2000-327948 A JP 2002-256170 A JP 2004-123800 A JP 2004-155648 A JP 2004-168559 A JP 2006-117445 A JP 2006-273588 A

  Inorganic particle powders that have excellent hydrophobicity and are difficult to desorb hydrophobizing agents from the surface of the particles are currently in the most demanding situation. Inorganic particle powders that sufficiently satisfy these characteristics are easily produced. A method has not yet been provided.

  Then, this invention makes it a technical subject to provide the manufacturing method of the inorganic particle powder which can provide the inorganic particle powder which has the outstanding hydrophobicity, and a hydrophobizing agent is hard to detach | desorb from the particle | grain surface.

  The technical problem can be achieved by the present invention as follows.

That is, the inorganic present invention is a method for producing the inorganic particles subjected to surface treatment, the inorganic particles and the surface modifier premixed, then subjected to surface treatment processes in an apparatus having a high speed shearing action A method for producing particle powder, wherein the inorganic particle powder is at least one selected from silica, titania, alumina, hydrous iron oxide, iron oxide and tin oxide, and the surface modifier is an organosilicon compound, the high-speed shearing action device high-speed shearing mill with a blade-type kneaders, a surface treatment process for the preparation of inorganic particles, characterized in that it is a one selected from a planetary mill (present invention 1).

In addition, the present invention is a surface-treated inorganic particle powder obtained by the production method described in the present invention 1 (Invention 2 ).

  The method for producing a surface-treated inorganic particle powder according to the present invention has an excellent hydrophobicity and an inorganic particle powder that can maintain excellent hydrophobicity over a long period of time because the hydrophobizing agent is not easily detached from the particle surface. Therefore, it is suitable as a method for producing a surface-treated inorganic particle powder.

  The surface-treated inorganic particle powder obtained by the production method according to the present invention has excellent hydrophobicity and maintains excellent hydrophobicity for a long period of time because the hydrophobizing agent is not easily detached from the particle surface. Therefore, it is suitable for various uses such as paint, resin kneading, toner and cosmetics.

  The configuration of the present invention will be described in more detail as follows.

  A method for producing the surface-treated inorganic particle powder according to the present invention will be described.

  The surface-treated inorganic particle powder according to the present invention can be obtained by previously mixing the surface modifier and the inorganic particle powder and then treating with a device having a high-speed shearing action.

  The inorganic particle powder used as the core particle powder in the present invention is not particularly limited, but is widely used as a colorant or a function-imparting agent in various applications such as resin kneading, paints, and cosmetics. Some silica, titania, alumina, hydrous iron oxide (goethite, lepidoccrosite, etc.), iron oxide (hematite, maghemite, magnetite, etc.), tin oxide, etc. can be used.

  The core particle powder has various shapes, such as spherical, granular, octahedral, hexahedral, and polyhedral granular particle powders, needle-shaped, spindle-shaped, and rice-shaped granular particle powders, and plate-like particle powders. Yes, it may be selected according to the application, and is not particularly limited.

The core particle powder in the present invention has an average particle size of 0.01 to 0.3 μm, a BET specific surface area value of 1.0 to 300 m ² / g, and a degree of hydrophobicity V ₉₀ usually exceeds 0.5 mg / m ² . Has a value.

  Among the inorganic particle powders that are the core particle powders in the present invention, in iron compounds such as hydrous iron oxide or iron oxide, the surface of the particles is previously made of aluminum hydroxide, aluminum oxide, silicon hydroxide, if necessary. And at least one intermediate coating selected from silicon oxides.

By covering the core particle powder in the present invention with the intermediate coating, the desorption of the hydrophobizing agent can be further suppressed, and the hydrophobicity V ₉₀ value after the desorption rate evaluation can be further reduced.

The amount of the intermediate coating is 0.01 to each of aluminum hydroxide and aluminum oxide in terms of Al, and silicon hydroxide and silicon oxide in terms of SiO _{2 with} respect to the core particle powder. 50 weight% is preferable, More preferably, it is 0.05-30 weight%, More preferably, it is 0.1-20 weight%.

When used in conjunction with an aluminum compound and a silicon compound, relative to core particles, 0.01 to 50 wt% in total of Al equivalent amount and SiO ₂ equivalent amount is preferred.

  The coating with the intermediate coating is performed by adding an aluminum compound, a silicon compound, or both of the compounds to an aqueous suspension obtained by dispersing inorganic particle powder and mixing and stirring, or if necessary, after mixing and stirring. By adjusting the value, the particle surface of the silica particles and / or inorganic particles is an intermediate coating made of at least one selected from aluminum hydroxide, aluminum oxide, silicon hydroxide and silicon oxide. And then filter, wash, dry and grind. If necessary, a deaeration / consolidation process may be further performed.

  As the aluminum compound, aluminum salts such as aluminum acetate, aluminum sulfate, aluminum chloride, and aluminum nitrate, and alkali aluminates such as sodium aluminate can be used.

  As the silicon compound, No. 3 water glass, sodium orthosilicate, sodium metasilicate and the like can be used.

  Any surface modifier may be used as the surface modifier in the present invention as long as the particle surface of the inorganic particles can be hydrophobized, such as fluoroalkylsilane, alkoxysilane, silane coupling agent, and organopolysiloxane. A compound is preferably used.

  Examples of the surface modifier in the present invention include trifluoropropyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecylmethyldimethoxysilane, trifluoropropylethoxysilane, and tridecafluoro. Octyltriethoxysilane, fluoroalkylsilanes such as heptadecafluorodecyltriethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, tetraethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane , Tetramethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, ethyltriethoxysilane, propyltriethoxy Lan, butyltriethoxysilane, isobutyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, alkoxysilanes such as decyltrimethoxysilane and decyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyl Triethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ Silane coupling agents such as glycidoxypropylmethyldimethoxysilane and γ-chloropropyltrimethoxysilane, dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpo Organopolysiloxanes such as siloxane, dimethylsiloxane, and methylphenylsiloxane copolymers, cyclic siloxanes such as octamethylcyclotetraphenylcyclotetrasiloxane, branched siloxanes such as tristrimethylsiloxysilane, tetrakistrimethylsiloxysilane, and tristrimethylsiloxyphenylsilane Higher alkoxy-modified silicones such as stearoxy silicone, alkyl-modified silicones, amino-modified silicones, fluorine-modified silicones, and the like.

  When the molecular chain of the hydrophobizing agent becomes large, it becomes difficult to evenly cover the particle surface by entering into the gaps between the aggregates of the core particle powder. Therefore, the hydrophobizing agent has 15 carbon atoms excluding the alkoxy group. In the following, it is preferable to use fluoroalkylsilane and alkoxysilane which are preferably 13 or less, more preferably 11 or less.

  In order to obtain inorganic particle powder having higher hydrophobicity, it is preferable to use fluoroalkylsilane and alkoxysilane in combination as a hydrophobizing agent, and it is preferable to coat alkoxysilane after coating with fluoroalkylsilane first.

  In the present invention, a higher fatty acid may be used in combination with the surface modifier.

  As higher fatty acids, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), isostearic acid, 12-hydroxystearic acid Etc.

  The amount of the surface modifier added is preferably 1 to 200 parts by weight with respect to 100 parts by weight of the inorganic particle powder that is the core particle.

  In addition, the addition amount of the higher fatty acid is preferably 1 to 50 parts by weight with respect to 100 parts by weight of the inorganic particle powder which is the core particle.

  The coating of the inorganic particle powder with the surface modifier can be performed by mechanically mixing and stirring the inorganic particle powder and the surface modifier, or by mechanically mixing and stirring the inorganic particle powder while spraying the surface modifier component. Good. Almost all of the added surface modifier is coated on the surface of the inorganic particles.

  In order to uniformly coat the surface of the inorganic particles with the surface modifier, it is preferable that the agglomeration of the inorganic particle powder is previously unraveled using a pulverizer.

  As an apparatus for mixing the inorganic particle powder and the surface modifier, an apparatus capable of applying a shearing force to the powder layer is preferable, and in particular, an apparatus capable of simultaneously performing shearing, spatula and compression, for example, A wheel-type kneader, a ball-type kneader, a blade-type kneader, or a roll-type kneader can be used. In carrying out the present invention, a wheel-type kneader can be used more effectively.

  Specific examples of the wheel type kneader include edge runners (synonymous with “mix muller”, “simpson mill”, “sand mill”), multi-mal, stotz mill, wet pan mill, conner mill, ring muller, and the like. , Preferably an edge runner, multi-mal, Stots mill, wet pan mill, and ring muller, and more preferably an edge runner. Specific examples of the ball kneader include a vibration mill. Specific examples of the blade-type kneader include a Henschel mixer, a planetary mixer, and a nauta mixer. Specific examples of the roll-type kneader include an extruder.

  The mixing condition is such that the surface of the inorganic particles is coated with a surface modifier. For example, in the case of silica particles, the linear load is 19.6 to 1960 N / cm (2 to 200 Kg / cm), preferably Is 98 to 1470 N / cm (10 to 150 Kg / cm), more preferably 147 to 980 N / cm (15 to 100 Kg / cm), and the treatment time is 5 to 120 minutes, preferably 10 to 90 minutes. What is necessary is just to adjust suitably. In addition, what is necessary is just to adjust process conditions suitably in the range of stirring speed 2-2000rpm, Preferably 5-1000rpm, More preferably, it is 10-800rpm.

  In the present invention, an apparatus capable of applying a shearing force to the powder layer at high speed is preferable, and examples thereof include a high-speed shear mill, a blade-type kneader, and a planetary mill, and a high-speed shear mill is preferable. Examples of the high-speed shear mill include a hybridizer and a nobilta (manufactured by Hosokawa Micron).

  The processing conditions of the apparatus that can apply a shearing force to the powder layer at a high speed may be appropriately adjusted within the range of 100 to 100,000 rpm, preferably 1000 to 50,000 rpm, as the stirring speed during mixing. The treatment conditions may be appropriately adjusted within the range of 1 to 120 minutes, preferably 2 to 90 minutes as the treatment time.

  You may perform a heating and a drying process at the time of a mixing process or after completion | finish of a mixing process. What is necessary is just to adjust suitably in 50-200 degreeC as heating temperature.

  The average particle diameter of the surface-treated inorganic particle powder according to the present invention is 0.005 to 0.3 μm, preferably 0.01 to 0.25 μm. When the average particle diameter is less than 0.005 μm, dispersion in the vehicle or the resin composition becomes difficult due to an increase in intermolecular force due to the refinement of the particles.

The BET specific surface area value of the surface-treated inorganic particle powder according to the present invention is preferably 1.0 to ²⁰⁰ m ² / g, more preferably 2.0 to 180 m ² / g. When the BET specific surface area value is less than 1.0 m ² / g, the particles are coarse or become particles that are sintered between the particles and dispersibility in the vehicle or the resin composition. This is undesirable because it adversely affects it. When the BET specific surface area exceeds 200 m ² / g, dispersion in the vehicle or the resin composition becomes difficult due to an increase in intermolecular force due to the finer particles.

The hydrophobicity V ₉₀ value (mg / m ² ) in the present invention is a value obtained by measuring the amount of water vapor adsorption in an atmosphere at a temperature of 25 ° C. and a relative humidity of 90%.

The hydrophobicity V ₉₀ value of the surface-treated inorganic particle powder according to the present invention is 0.5 mg / m ² or less. If the degree of hydrophobicity V ₉₀ of the inorganic particle powder exceeds 0.5 mg / m ² , the hydrophobicity of the inorganic particle powder cannot be said to be sufficient, and when blended in a vehicle or resin composition, resin or organic Familiarity with the medium is poor and uniform dispersion becomes difficult. The degree of hydrophobicity V ₉₀ is preferably 0.45 mg / m ² or less, more preferably 0.40 mg / m ² or less. The lower limit value of the degree of hydrophobicity V ₉₀ is 0.01 mg / m ² .

  The desorption rate of the hydrophobizing agent of the surface-treated inorganic particle powder according to the present invention is preferably 10% or less. When the desorption rate exceeds 10%, moisture absorption proceeds from the portion where the hydrophobizing agent is detached, and it becomes difficult to maintain the hydrophobicity for a long time. More preferably, it is 9% or less, and more preferably 8% or less.

The degree of hydrophobicity V ₉₀ after the desorption rate evaluation of the surface-treated inorganic particle powder according to the present invention is 0.55 mg / m ² or less. If the degree of hydrophobicity V ₉₀ after the desorption rate evaluation exceeds 0.55 mg / m ² , the hydrophobicity of the inorganic particle powder is not sufficient, and it is difficult to maintain the hydrophobicity for a long period of time. It becomes. The hydrophobicity V ₉₀ value after the desorption rate evaluation is preferably 0.53 mg / m ² or less, more preferably 0.50 mg / m ² or less.

  The surface coverage by the organosilane compound produced from fluoroalkoxysilane or alkoxysilane is 0.1 to 40% by weight in terms of C with respect to the surface-treated inorganic particle powder, and preferably 0.2 to 20%. % By weight.

  When the surface coating amount is less than 0.1% by weight, the particle surface of the inorganic particle powder cannot be sufficiently covered, so that the obtained inorganic particle powder cannot obtain sufficient hydrophobicity and is hydrophobic over a long period of time. It becomes difficult to maintain the sex. If it exceeds 40% by weight, the effect is saturated, so there is no point in covering more than necessary.

  Next, the surface-treated inorganic particle powder according to the present invention may be contained in rubber or a thermoplastic resin to form a rubber / resin composition.

  As the base material in the rubber / resin composition, together with the surface-treated inorganic particle powder according to the present invention and a known rubber or thermoplastic resin, if necessary, lubricant, plasticizer, antioxidant, ultraviolet absorber, various kinds Additives such as stabilizers are blended.

  The blending ratio of the surface-treated inorganic particle powder in the rubber / resin composition can be used in the range of 0.5 to 200 parts by weight with respect to 100 parts by weight of the constituent base material. Handling of the rubber / resin composition Is preferably 1.0 to 150 parts by weight, more preferably 2.5 to 100 parts by weight.

  The amount of the additive may be 50% by weight or less based on the sum of the surface-treated inorganic particle powder and rubber or resin. When the content of the additive exceeds 50% by weight, the moldability is lowered.

  As a method for producing a rubber / resin composition, rubber or resin raw material and surface-treated inorganic particle powder are mixed well in advance, and then a strong shearing action is applied under heating using a kneader or an extruder. The aggregate of the surface-treated inorganic particle powder is broken and the surface-treated inorganic particle powder is uniformly dispersed in rubber or resin, and then molded into a shape according to the purpose and used.

<Action>
The important point in the present invention is that when the inorganic particle powder and the surface modifier are mixed in advance and then treated with an apparatus having a high-speed shearing action, the surface modifier is treated more uniformly and the surface modification is performed. When the material has hydrophobicity, the degree of hydrophobicity is ₉₀ mg / m ² or less in terms of water vapor adsorption amount V ₉₀ , and the degree of hydrophobicity V ₉₀ after the desorption rate evaluation is 0.55 g / m ^2. The following surface-treated inorganic particle powder can be obtained, which is the fact that the surface-treated inorganic particle powder has excellent hydrophobicity and the hydrophobizing agent is hardly detached from the particle surface.

  As the reason why the surface-treated inorganic particle powder according to the present invention has excellent hydrophobicity, the present inventor is able to apply shear force to the powder layer even when the core particle powder forms an aggregate. It is considered that the agglomerated particles can be crushed by adding sucrose and further treated with a device having a high-speed shearing action to uniformly coat the surface of the core particle powder with the hydrophobizing agent. .

  The method for producing a surface-treated inorganic particle powder according to the present invention can perform all steps in a dry process, and does not need to be treated in an organic solvent, and has high hydrophobicity even for a short time. Since inorganic particle powder is obtained, it is industrially excellent.

  Hereinafter, the present invention will be described in detail with reference to examples.

  The average particle diameter of the core particle powder and the surface-treated inorganic particle powder is a fixed direction for about 350 particles shown in a photograph obtained by enlarging the electron micrograph (× 20,000) four times in the vertical and horizontal directions. Each diameter was measured and indicated by its average value.

  The specific surface area value was indicated by a value measured by the BET method.

The coating amount of the surface modifier coated on the particle surface of the inorganic particle powder is determined by measuring the carbon amount using “Horiba Metal Carbon / Sulfur Analyzer EMIA-2200” (manufactured by Horiba, Ltd.). Asked.
The amount of Al and Si present on the particle surface of the core particle powder coated with the intermediate coating is “fluorescence X-ray analyzer 3063M type” (manufactured by Rigaku Denki Kogyo Co., Ltd.). Measurement was performed according to the "General Rules for X-ray Analysis"

The hydrophobization degree of the core particle powder and the surface-treated inorganic particle powder was measured per unit surface area of the particle powder at 25 ° C. and a relative humidity of 90% using a “water vapor adsorption device BELSORP18” (manufactured by Nippon Bell Co., Ltd.). Water vapor adsorption amount V ₉₀ value (mg / m ² ).

  The desorption rate of the hydrophobizing agent of the inorganic particle powder was indicated by the value obtained by the following method. The closer the desorption rate is to 0, the smaller the amount of desorption of the hydrophobizing agent from the particle surface.

  3 g of inorganic particle powder and 50 ml of ethanol are placed in a 50 ml Erlenmeyer flask and subjected to ultrasonic dispersion for 20 minutes using an ultrasonic disperser “SONOQUICK C10” (manufactured by Ultrasonic Industry Co., Ltd.), and then for 15 minutes at 10,000 rpm. Centrifugation was performed to separate the supernatant and the solid part.

  The obtained solid part and 50 ml of ethanol were placed in a 50 ml Erlenmeyer flask, and the same operation as described above was performed three times in total.

  After the obtained solid part was dried at 100 ° C. for 1 hour, the carbon content (C conversion) contained in the inorganic particle powder was set to “Horiba Metal Carbon / Sulfur Analyzer EMIA-2200 type” (Horiba Co., Ltd.). The value obtained according to the following formula was taken as the desorption rate of the hydrophobizing agent.

Desorption rate of hydrophobizing agent (%) = {(Wa-We) / Wa} × 100
Wa: Hydrophobizing agent coating amount of inorganic particle powder (C conversion)
We: Hydrophobizing agent coating amount of inorganic particle powder after desorption test (C conversion)

The degree of hydrophobicity after evaluation of the desorption rate was determined by using a “water vapor adsorption device BELSORP18” (manufactured by Nippon Bell Co., Ltd.) for the particle powder after the desorption rate was evaluated by the above-described measurement method. The amount of water vapor adsorbed per unit surface area of the particle powder at ₉₀ V (mg / m ² ).

Example 1 <Production of surface-treated inorganic particle powder>
10.0 kg of silica particle powder (particle shape: spherical, average particle diameter 0.01 μm, BET specific surface area value 201.2 m ² / g, hydrophobicity V ₉₀ value 6.24 mg / m ² ) The product was put into a “type” (product name, manufactured by Matsumoto Casting Iron Works Co., Ltd.) and mixed and stirred at 294 N / cm (30 Kg / cm) for 30 minutes to loosen the particles.

  Next, 2000 g of methyltriethoxysilane (trade name: TSL8123: manufactured by GE Toshiba Silicone Co., Ltd.) is added to the silica particle powder while operating the edge runner, and the line load of 588 N / cm (60 Kg / cm) is used for 30 minutes. Mixing and stirring were performed. The stirring speed at this time was 22 rpm.

Next, 100 g of the obtained silica particle powder coated with the surface modifier was placed in a high-speed shearing mill, and subjected to high-speed shearing treatment at a rotational speed of 2450 rpm for 20 minutes. The obtained hydrophobized silica particle powder has an average particle size of 0.01 μm, a BET specific surface area value of 98.2 m ² / g, a degree of hydrophobicity V ₉₀ value of 0.49 mg / m ² , and a desorption rate of 5. The V ₉₀ value after evaluation of 0% and the desorption rate was 0.51 mg / m ² .

  A surface-treated inorganic particle powder was produced according to the above example.

Core particles 1 to 3
As the core particle powder, inorganic particle powder and inorganic powder having the characteristics shown in Table 1 were prepared.

Examples 2-4, Comparative Examples 1-2
Surface treatment was carried out in the same manner as in Example 1 except that the kind of core particle powder, the kind and addition amount of the surface modifier, the treatment condition by the edge runner, and the treatment condition of the apparatus having a high-speed shearing action were variously changed. Inorganic particle powder was obtained.

  The production conditions at this time are shown in Table 2, and the properties of the obtained surface-treated inorganic particle powder are shown in Table 3.

The surface-treated inorganic particle powder according to the present invention has excellent hydrophobicity and can maintain excellent hydrophobicity for a long period of time because the hydrophobizing agent is not easily detached from the particle surface. It is suitable for various uses such as resin kneading, toner and cosmetics.

Claims (2)

A surface treatment process for the preparation of inorganic particles, an inorganic particles and surface modifier premixed, then surface-treated with the manufacturing method of the inorganic particles treated with a device having a high speed shearing action The inorganic particle powder is at least one selected from silica, titania, alumina, hydrous iron oxide, iron oxide and tin oxide, the surface modifier is an organosilicon compound, and has a high-speed shearing action There high shear mill, a blade-type kneader, a surface treatment process for the preparation of inorganic particles, characterized in that it is a one selected from the planetary mill. Surface-treated inorganic particles, characterized in that obtained by serial mounting has been manufacturing method in claim 1.