JP2012140530A - Dispersion stabilizer and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dispersion stabilizer excellent in dispersion stability (especially for the dispersion stability of pigments).SOLUTION: This dispersion stabilizer includes (a) amphiphilic particles and (b) an oily component, wherein (a) the amphiphilic particles have hydrophilic surfaces and hydrophobic surfaces and obtained by surface-modifying dry type hydrophilic silica fine particles having 50 to 300 m/g BET specific surface area by a hydrophobizing agent and having 1 to 20 M value. The method for producing such dispersion stabilizer includes a dispersing process of dispersing the dry type hydrophilic silica fine particles in the oil component (b) to obtain the dispersion of the hydrophilic silica fine particles in the oily component; a surface-modifying process of surface-modifying the dry type silica fine particles dispersed in the dispersion of the hydrophilic silica fine particles in the oily component to obtain the dispersion of hydrophobized silica fine particles in the oily component; and a crushing process of crushing the hydrophobized silica fine particles contained in the dispersion of the hydrophobized silica fine particles in the oily component to obtain (a) the amphiphilic particles.

Description

  The present invention relates to a dispersion stabilizer and a method for producing the same.

  Conventionally, an inorganic dispersion stabilizer in which a hydrophobic inorganic oxide is dispersed in an aqueous medium in the presence of a hydrophilic organic compound is known (Patent Document 1).

JP-A-10-237216

  However, the conventional inorganic dispersion stabilizer has a problem that the dispersion stability is low, and the dispersibility of the pigment is particularly low. That is, an object of the present invention is to provide a dispersion stabilizer having excellent dispersion stability (particularly pigment dispersion stability).

A feature of the dispersion stabilizer of the present invention is a dispersion stabilizer comprising amphiphilic particles (a) and an oily component (b),
The amphiphilic particles (a) are obtained by surface-modifying dry hydrophilic silica fine particles having a hydrophilic surface and a hydrophobic surface and having a BET specific surface area of 50 to 300 m ² / g with a hydrophobizing agent, The gist is that it is an amphiphilic particle having an M value of 1-20.

A feature of the production method of the present invention is a method for producing the above dispersion stabilizer,
A dispersion step in which dry hydrophilic silica fine particles are dispersed in the oil component (b) to obtain a hydrophilic silica fine particle oil component dispersion;
A surface modification step for obtaining a hydrophobized silica fine particle oil component dispersion by surface-modifying dry hydrophilic silica fine particles dispersed in the hydrophilic silica fine particle oil component dispersion; and included in the hydrophobized silica fine particle oil component dispersion The present invention includes a crushing step of crushing the hydrophobized silica fine particles to obtain the amphiphilic particles (a).

The dispersion stabilizer of the present invention is excellent in dispersion stability (particularly pigment dispersion stability). Therefore, the dispersion stabilizer of the present invention is a dispersion stabilizer for suspension / emulsion polymerization, a dispersion stabilizer for textile industry, a dispersion stabilizer for ink, a dispersion stabilizer for paint, a dispersion stabilizer for plastics, a dispersion stabilizer for agricultural chemical industry. Suitable as an agent or the like.
The dispersion stability includes emulsion stability, and the dispersion stabilizer includes an emulsion stabilizer (the same applies hereinafter).

  The production method of the present invention is suitable for producing the above dispersion stabilizer, and can easily produce the above dispersion stabilizer.

<Amphiphilic particles (a)>
The amphiphilic particles (a) are silica fine particles having a hydrophilic surface and a hydrophobic surface, and the surface of the silica fine particles is divided into a hydrophilic surface and a hydrophobic surface. Such silica fine particles include fine particles obtained by crushing dry hydrophilic silica fine particles with a hydrophobizing agent after surface modification (hydrophobization treatment). When dry hydrophilic silica fine particles are surface-modified (hydrophobized) and then crushed, the original surface of the dry hydrophilic silica fine particles (the surface that appears after crushing) is a hydrophilic surface, and the surface is modified. Becomes a hydrophobic surface.

  The term “split” means that the hydrophilic surface and the hydrophobic surface are localized on the surface of one silica particle as if the positive electrode and the negative electrode were localized in one magnet (one This is different from the case where a hydrophilic surface and a hydrophobic surface are scattered on the surface of silica particles).

It can be confirmed by the following method that the surface of the amphiphilic particles (a) is divided into a hydrophilic surface and a hydrophobic surface.
<Confirmation method that the surface is divided>
5 mL of ion-exchanged water and 5 mL of n-hexane are placed in a test tube, and 0.02 g of a dispersion in which a measurement sample (amphiphilic particles (a) and the like) is dispersed in isopropanol at a concentration of 1% by weight is added thereto. Let stand for a minute (the purity of each measuring reagent is 99% by weight or more).
When the surface of the measurement sample is divided into a hydrophilic surface and a hydrophobic surface, a uniform aggregate layer of the measurement sample (amphiphilic particles (a)) is formed at the interface between water and n-hexane. The upper layer and the lower layer form clean layers that do not contain the measurement sample (amphiphilic particles (a) and the like).
On the other hand, when the surface is not divided into a hydrophilic surface and a hydrophobic surface (in the case of particles in which the hydrophilic surface and the hydrophobic surface are uniformly dispersed (scattered) on the particle surface), the measurement sample (particle) is It is dispersed in the aqueous phase or n-hexane layer, or agglomerates are formed at the interface between water and n-hexane, and a uniform aggregate layer is not formed at the interface.

  The amphiphilic particles (a) can be isolated from the dispersion stabilizer of the present invention as follows. That is, a white precipitate formed by mixing 50 g of a dispersion stabilizer with 450 g of n-hexane was taken out by centrifugation and dried for 12 hours in a 100 ° C. forward air dryer to obtain amphiphilic particles (a). Can be isolated.

  The M value of the amphiphilic particles (a) is 1 to 20, preferably 5 to 15, more preferably 7 from the viewpoint of the dispersion stability of the dispersion stabilizer (hereinafter simply referred to as dispersion stability). ~ 13. The M value is a concept representing the degree of hydrophobicity of the fine particles, and the higher the M value, the lower the hydrophilicity. When the measurement sample is uniformly dispersed in the water / methanol mixed solution, the volume of the minimum amount of methanol required It is expressed as a percentage and can be determined by the following method.

<M value calculation method>
0.2 g of a measurement sample (such as amphiphilic particles (a)) is added to 50 mL of water in a beaker having a capacity of 250 mL, and then methanol is dropped from the burette until the entire amount of the measurement sample is suspended. At this time, the solution in the beaker is constantly stirred with a magnetic stirrer, and the time when the whole amount of the measurement sample is uniformly suspended in the solution is set as the end point, and the volume percentage of methanol in the liquid mixture of the beaker at the end point becomes the M value.

  The amphiphilic particles (a) can be isolated by the same method as described in the above <Method for confirming that the surface is divided>.

  Dry hydrophilic silica fine particles are silica obtained by burning a gas such as a silicon salt compound (silicon tetrachloride, etc.) in an oxygen-hydrogen flame {generated by neutralizing sodium silicate with an acid in an alkaline environment. Silica obtained by filtering and drying the precipitate (precipitation silica), and silica obtained by neutralizing sodium silicate with an acid in an acidic environment, and filtering and drying the resulting precipitate (gel method) (Silica). }.

  The dry hydrophilic silica fine particles can be easily obtained from the market, and examples thereof include the following products.

  Aerosil series {Nippon Aerosil Co., Ltd. and Evonik Degussa, "Aerosil" is a registered trademark of Evonik Degussa GmbH. }, Reolosil series {Tokuyama Corporation, “Reorosil” is a registered trademark of Tokuyama Corporation. }, Cab-O-Sil series {Cabot Corporation, "Cab-O-Sil" is a registered trademark of Cabot Corporation. }, HDK series {Asahi Kasei Wacker Silicone Co., Ltd., HDK is a registered trademark of WACKER CHEMIE AG. }etc.

The specific surface area (m ² / g) of the dry hydrophilic silica fine particles by the BET method is 50 to 300, but 100 to 200 is preferable from the viewpoint of dispersion stability.

  In addition, the specific surface area by BET method is a value measured based on JIS R1626-1996 (one point method) {measurement sample: 50 mg (sample heat-processed for 15 minutes at 200 degreeC), the measuring method of adsorption amount: Isolytic method, adsorbate: mixed gas (N270 volume%, He 30 volume%), measurement equilibrium relative pressure: 0.3, apparatus: for example, Okura Riken Co., Ltd., fully automatic powder surface measuring apparatus AMS-8000}.

  As the hydrophobizing agent, halosilane, alkoxysilane, silazane, C3-C36 aliphatic alcohol, silicone compound, and the like can be used.

  Examples of the halosilane include alkylhalosilane having an alkyl group having 1 to 12 carbon atoms and arylhalosilane having an aryl group having 6 to 12 carbon atoms, such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, and trimethylbromosilane. , Ethyltrichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, t-butyldimethylchlorosilane, and the like.

  Examples of the alkoxysilane include an alkoxysilane having an alkyl group having 1 to 12 carbon atoms (including methacryloxyalkyl), an alkenyl group or an aryl group, and an alkoxy group having 1 to 2 carbon atoms, such as methyltrimethoxysilane, dimethyl Dimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxy Silane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, i-butyl Triethoxysilane, decyl triethoxysilane, vinyltriethoxysilane, and γ- methacryloxypropyl trimethoxy silane, and the like.

  Examples of silazane include hexamethyldisilazane.

  Examples of the aliphatic alcohol having 3 to 36 carbon atoms include isopropanol, normal butanol, normal pentanol, normal octanol, dodecanol, stearyl alcohol, and behenyl alcohol.

  Examples of the silicone compound include dimethylpolysiloxane, hydroxyl group-modified polysiloxane, and methylhydrogen polysiloxane.

As dimethylpolysiloxane, one having a kinematic viscosity at 25 ° C. of 1 to 10,000 mm ² / s can be used.

As the hydroxyl group-modified polysiloxane and methyl hydrogen dimethyl polysiloxane, those having a kinematic viscosity at 25 ° C. of 1 to 10,000 mm ² / s and a functional group equivalent of 300 to 8000 g / mol can be used.

  As a hydrophobizing agent used for surface modification of dry hydrophilic silica fine particles, in addition to the above, known coupling agents (silane coupling agents other than the above, titanate coupling agents, zircoaluminate coupling agents, etc.) ) Etc. can also be used.

  Of these hydrophobizing agents, halosilane, silazane, and alkoxysilane are preferable from the viewpoint of dispersion stability and the like.

  A known method can be applied to the surface modification with the hydrophobizing agent, for example, by the methods described in <Surface modification method 1> to <Surface modification method 3> below.

<Surface modification method 1>
A surface modification method (dry method) in which a mixture of dry hydrophilic silica fine particles and a hydrophobizing agent is surface-modified while stirring with a stirrer to obtain hydrophobic silica fine particles.

<Surface modification method 2>
A surface modification method (gas phase method) in which a gas containing a hydrophobizing agent, which has been heated and vaporized, is introduced into a reaction vessel equipped with a stirrer containing dry hydrophilic silica fine particles to modify the surface to obtain hydrophobic silica fine particles.

<Surface modification method 3>
After the dry hydrophilic silica fine particles are dispersed in the oil component (b) to obtain a dry hydrophilic silica fine particle oil component dispersion, a hydrophobizing agent is added while stirring the dry hydrophilic silica fine particle oil component dispersion. Surface modification method (in-liquid method) to obtain a hydrophobized silica fine particle oil component dispersion.

  Of these surface modification methods, <surface modification method 3> is preferred. When these preferable methods are applied, the dispersion stability is further improved. This is presumably because the hydrophilic surface and the hydrophobic surface on the surface of the amphiphilic particles (a) are likely to be localized, and the surface activity of the amphiphilic particles (a) is improved.

  When performing surface modification by <surface modification method 3>, a solvent (s) may be used in combination. Examples of the solvent (s) include alcohols, ketones, esters, ethers, aromatic hydrocarbons, alicyclic hydrocarbons, and aliphatic hydrocarbons.

  As alcohol, C1-C10 alcohol etc. can be used, methanol, ethanol, normal propanol, isopropanol, normal butanol, isobutanol, secondary butanol, 3-methoxy-3-methyl-1-butanol, ethylene glycol, diethylene glycol , Ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether , Ethylene glycol monobutyl ether Diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, and propylene glycol monobutyl ether.

  As the ketone, a ketone having 3 to 6 carbon atoms can be used, and examples thereof include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

  As the ester, an ester having 4 to 10 carbon atoms can be used, and examples thereof include ethyl acetate, butyl acetate, ethyl cellosolve acetate, butyl cellosolve acetate, butyl carbitol acetate, and propylene glycol monomethyl ether acetate.

  As ethers, ethers having 4 to 10 carbon atoms can be used. Ethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, propylene Examples include glycol diethyl ether, dipropylene glycol diethyl ether, and 1,4-dioxane.

  As the aromatic hydrocarbon, an aromatic hydrocarbon having 6 to 9 carbon atoms can be used, and examples thereof include benzene, toluene, xylene, ethylbenzene, and trimethylbenzene.

  As the alicyclic hydrocarbon, an alicyclic hydrocarbon having 5 to 10 carbon atoms can be used, and examples thereof include cyclopentane, cyclohexane, cyclopeptane, cyclooctane, cyclononane, and cyclodecane.

  As the aliphatic hydrocarbon, an aliphatic hydrocarbon having 5 to 10 carbon atoms can be used, and examples thereof include pentane, hexane, peptane, octane, nonane, and decane.

  In addition to the above, chlorinated solvents (dichloromethane, trichloromethane, methyl chloride, dichloroethane, tetrachloroethane, ethyl chloride, etc.), petroleum ether, petroleum naphtha, and the like can also be used. Of these solvents (s), aromatic hydrocarbons, alicyclic hydrocarbons, and aliphatic hydrocarbons are preferred.

  When the solvent (s) is used in combination, the addition amount (% by weight) of the solvent (s) is preferably 10 to 50 based on the total weight of the oil component (b).

  In <Surface Modification Method 3>, the following <Dispersion Method 1> to <Dispersion Method 3> and the like can be applied as a method for obtaining a dry hydrophilic silica fine particle oil component dispersion.

<Dispersion method 1>
A method in which dry hydrophilic silica fine particles and an oil component (b) are simultaneously placed in a dispersion container and uniformly dispersed.

<Dispersion method 2>
A method in which an oily component (b) is added to a dispersion container containing dry hydrophilic silica fine particles in advance and uniformly dispersed.

<Dispersion method 3>
A method in which dry hydrophilic silica fine particles are added to a dispersion container containing the oil component (b) in advance and uniformly dispersed.

  Among these dispersion methods, <dispersion method 1> and <dispersion method 3> are preferable, and <dispersion method 3> is more preferable because the dispersion stability tends to be further improved.

  For dispersion, a known disperser {saddle type wing stirrer, high speed shear disperser (high speed rotating homomixer, high pressure homogenizer, high speed rotating centrifugal radiation stirrer, etc.), kneader, three roll mill, ultrasonic Disperser, planetary mixer, triaxial planetary mixer, wet medium type disperser {bead mill, sand grinder, colloid mill, attritor (manufactured by Nihon Coke Industries Co., Ltd., "Attritor" is a registered trademark of Nippon Coke Industries, Ltd. Etc.), vertical single-shaft type powder stirrer {Henschel mixer (Mitsui Mining Co., Ltd., “Henschel mixer” is a registered trademark of Mitsui Mining Co., Ltd.)}, horizontal single-shaft stirrer (ribbon mixer) Etc.), and vertical single- and double-shaft stirrers (universal mixers, rakai machines, etc.).

  The planetary mixer is a disperser in which the container and / or the stirring blade rotates in a planetary manner, and is a planetary mixer having two blade-type stirring blades that perform planetary motion, a planetary stirring and defoaming device (for example, a special mixer The three-axis planetary mixer includes two blade-type stirring blades that perform planetary motion and a small high-speed rotation that performs at least one planetary motion. And a planetary mixer having blades (for example, registered utility model No. 3026043).

  Among these dispersers, a high-speed shearing disperser and a three-axis planetary mixer are preferable because the dispersion stability is further improved.

  The dispersion temperature is not particularly limited and may be appropriately selected depending on the type of the oil component (b), but is preferably 30 to 150 ° C (more preferably 50 to 120 ° C). The time required for dispersion is preferably 5 minutes to 10 hours, more preferably 10 minutes to 5 hours, and particularly preferably 15 minutes to 3 hours.

  In <Surface Modification Method 3>, the content (% by weight) of the dry hydrophilic silica fine particles is 0.1 to 10 (more preferably 0.5 to 8, based on the total weight of the oil component (b). Particularly preferred is 1 to 5). Within this range, the dispersion stability is further improved.

In <Surface Modification Method 1> to <Surface Modification Method 3>, the above-described known disperser can be used for stirring.
Among the above-mentioned dispersers, in <Surface Modification Method 1> and <Surface Modification Method 2>, a planetary mixing disperser, a vertical single-shaft powder stirrer, a horizontal single-shaft stirrer, and a vertical single Axial stirrer is preferable, more preferably a single-shaft powder stirrer, a horizontal single-shaft stirrer, and a vertical single-double-shaft stirrer. A mold mixer and a three-axis planetary mixer are preferred.

  The use amount (% by weight) of the hydrophobizing agent is preferably 0.5 to 20, more preferably 1 to 5, based on the weight of the dry hydrophilic silica fine particles. Within this range, the dispersion stability is further improved.

  The hydrophobized silica fine particle oil component dispersion obtained in <Surface Modification Method 3> may be used as it is. The oily component (b) is removed from the hydrophobized silica fine particle oil component dispersion, dried, and made hydrophobic. Silica fine particles may be taken out and used.

The oily component (b) is removed by (1) a method of distilling and removing the oily component (b) using a reaction vessel equipped with a heating device and a stirrer or a rotary evaporator, and (2) diluting with a solvent. The hydrophobized silica fine particle oil component dispersion is filtered and solid-liquid separated. (3) The hydrophobized silica fine particle oil component dispersion diluted with a solvent is centrifuged, and the supernatant is removed. It can be carried out.
As the solvent for diluting the hydrophobized silica fine particle oil component dispersion, the same solvent as the solvent (s) can be used.

  Drying can be performed by a known method such as heat drying (for example, heat drying for 10 to 120 minutes in a drying furnace heated to 30 to 150 ° C.) or reduced pressure drying, a far-infrared dryer, a vacuum dryer, A hot air dryer, a fluidized bed dryer, or the like can be used.

The amphiphilic particles (a) can be obtained by crushing hydrophobized silica fine particles.
Crushing means that one hydrophobized silica fine particle is divided into at least two fine particles. By crushing, the surface of the hydrophobized silica fine particle becomes hydrophilic (new surface generated by crushing) and hydrophobic. The surface is divided into a hydrophobic surface (hydrophobized surface).

  The crushing can be performed by a method of wet crushing the hydrophobized silica fine particle dispersion.

As the hydrophobic silica fine particle dispersion in the wet crushing, the following hydrophobic silica fine particle dispersion can be used.
(Dispersion 1) Hydrophobized silica fine particle dispersion in which hydrophobic silica fine particles are dispersed in an oil component (b).
(Dispersion 2) Hydrophobized silica fine particle oil component dispersion obtained by <Surface modification method 3>.

  In (Dispersion 1), for dispersing the hydrophobized silica fine particles and the oil component (b), a known disperser used in the above dispersion can be used, and a preferable disperser is also the same. The dispersion method of (dispersion 1) can be performed by the same method as the above <dispersion method 1> to <dispersion method 3>, and the preferred method is also the same.

  The proportion (% by weight) of the hydrophobized silica fine particles in the hydrophobized silica fine particle dispersion is 0.1 to 10 (more preferably 0.5 to 8, particularly preferably, based on the total weight of the oil component (b). 1-5) are preferred. Within this range, the dispersion stability is further improved. This is presumably because the viscosity of the dispersion is lowered and the crushing proceeds well.

  The crushing can be carried out using a known crushing and dispersing machine. As the crushing and dispersing machine, a wet medium type crushing and dispersing machine {bead mill, sand grinder, colloid mill, attritor (manufactured by Nippon Coke Kogyo Co., Ltd., "Attritor"). Are registered trademarks of Nippon Coke Industries, Ltd.), DISPERMAT (VMA-GETAMANN GMBH), etc.}, high-pressure jet crushing and dispersing machine {Nanomizer (Yoshida Kikai Co., Ltd. Is a registered trademark of the company.), Starburst (manufactured by Sugino Machine Co., Ltd., “Starburst” is a registered trademark of Sugino Machine Co., Ltd.), Gorin homogenizer (manufactured by APV), etc.}, and high-speed shearing dispersion Machine (high speed rotating homomixer, high pressure homogenizer, dissolver, and 3 A planetary mixer, etc.), and the like can be used. Among these, a high-speed shearing type disperser is preferable in that re-aggregation of the hydrophobized silica fine particles hardly occurs and the dispersion stability is further improved.

The crushing temperature is not particularly limited and can be appropriately selected according to the type of the oil component (b) of the hydrophobized silica fine particle oil component dispersion. For example, the crushing temperature is 30 to 150 ° C. (preferably 50 to 120 ° C.). Can do.
The crushing time is preferably 5 minutes to 10 hours, more preferably 10 minutes to 5 hours, and particularly preferably 15 minutes to 3 hours.

The amphiphilic particles (a) may be used after removing the oily component (b) from the hydrophobized silica fine particle oily component dispersion after the crushing step and drying.
The oily component (b) can be removed in the same manner as in the above-mentioned known method, and the drying after the removal can also be carried out in the same manner as in the above-mentioned known method.

  The volume average particle diameter (μm) of the amphiphilic particles (a) is preferably 0.05 to 1, and more preferably 0.1 to 0.5. Within this range, the dispersion stability is further improved.

The volume average particle diameter of the amphiphilic particles (a) is based on JIS Z8825-1: 2001 using a dispersion liquid in which the amphiphilic particles (a) are dispersed in isopropanol so as to have a concentration of 1% by weight. Measured at a measurement temperature of 25 ± 5 ° C. using a laser diffraction particle size analyzer {for example, Microtrac series manufactured by Lees & Northrup, Partica LA series manufactured by HORIBA, Ltd.], and then measured 1.377 as the refractive index of isopropanol Using 1.457 as the refractive index of the sample, the 50% cumulative volume average particle diameter is obtained.
In addition, the amphiphilic particles (a) used for the measurement of the volume average particle diameter are obtained by centrifuging a white precipitate produced by mixing 50 g of a dispersion containing amphiphilic particles (a) with 450 g of n-hexane. It can be isolated by taking out and drying for 12 hours in a 100 ° C. normal air dryer.

<Oil component (b)>
As the oil component (b), hydrocarbon oil, fatty acid, fatty acid amide, fatty acid ester, higher alcohol, silicone, polyoxyalkylene compound, and the like can be used.

As the hydrocarbon oil, a hydrocarbon oil having a kinematic viscosity at 40 ° C. of 0.1 to 3500 mm ² / s can be used, paraffin, polyolefin, hydrogenated hydrocarbon obtained by hydrogenating polyolefin, alkylbenzene, alkylnaphthalene, and these A mixture of

  Examples of paraffin include normal paraffin and isoparaffin.

  Examples of the polyolefin include polybutene, 1-decene oligomer, and a co-oligomer of 1-decene and ethylene.

  Examples of hydrogenated hydrocarbons obtained by hydrogenating polyolefins include hydrogenated hydrocarbons obtained by hydrogenating polyolefins, and examples thereof include hydrogenated polybutene and hydrogenated polyisobutene.

  Examples of the alkyl benzene include alkyl benzene having 1 to 8 carbon atoms in the alkyl group, and examples thereof include monoalkyl benzene and dialkyl benzene.

  Alkyl naphthalene includes alkyl naphthalene having 1 to 18 carbon atoms in the alkyl group, and examples thereof include monoalkyl naphthalene, dialkyl naphthalene, and polyalkyl naphthalene.

  These hydrocarbon oils can be obtained by petroleum refining or solvent refining, olefin monomer polymerization reaction, organic synthesis reaction (Fischer-Tropsch method, etc.) and the like.

  Fatty acids include fatty acids having 8 to 28 carbon atoms, octanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, 2-ethylhexanoic acid, oleic acid, capric acid, behenic acid. , 12-hydroxystearic acid, 2-heptylundecanoic acid, undecylenic acid, and montanic acid.

  Examples of fatty acid amides include acid amides of the fatty acids (such as lauric acid amide, stearic acid amide, and erucic acid amide), and N-substituted acid amides (N, N′-ethylenebislauric acid amide, N, N′-methylene). Bistearic acid amide, N, N′-ethylene bisstearic acid amide, N, N′-ethylene bisoleic acid amide, N, N′-ethylene bisbehenic acid amide, N, N′-butylene bisstearic acid amide, N , N'-hexamethylenebisstearic acid amide, N, N'-hexamethylenebisoleic acid amide, N, N'-xylylene bisstearic acid amide, monostearic acid stearic acid amide, stearic acid diethanolamide, N-oleyl stearin Acid amide, N-oleyl oleic acid amide, N-stearyl stearic acid De, N- stearyl oleic acid amide, N- oleyl palmitic acid amide, and N- stearyl erucic acid amide, etc.) and the like.

  Examples of fatty acid esters include esters of the above fatty acids (isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, 2,2-dimethyloctanoic acid 2-hexyldecyl, isocetyl stearate, isocetyl isostearate, cholesteryl 12-hydroxystearylate, ethylene glycol 2-ethylhexanoic acid diester, neopentylglycol capric acid diester, glycerin 2-heptylundecanoic acid diester, trimethylolpropane 2-ethyl Hexanoic acid triester, trimethylolpropane isostearic acid triester, pentane erythritol 2-ethylhexanoic acid tetras Glycerin 2-ethylhexanoic acid triester, trimethylolpropane isostearic acid triester, 2-ethylhexyl palmitate, glycerin myristic acid triester, glycerin 2-heptylundecanoic acid triester, castor oil fatty acid methyl ester, oleic oleate, 2-heptylundecyl palmitate, ethyl laurate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, etc., and esters of higher alcohols described later (cetyl lactate, myristyl lactate, lanolyl acetate, diisostearyl malate) , Di-2-heptylundecyl adipate, cetyl 2-ethylhexanoate, etc.), polyhydric alcohol acetate (glycerin triacetate, and trimethylolpropane triacetate) ), And lower (1-4 carbon atoms) polyhydric fatty alcohols (6-10 carbon atoms) esters (diisobutyl adipate, sebacic acid diisopropyl, and malic acid dipropyl like).

  Examples of the higher alcohol include aliphatic alcohols having 12 to 36 carbon atoms (such as cetyl alcohol, stearyl alcohol, isostearyl alcohol, 2-heptylundecyl alcohol, lanolin alcohol, behenyl alcohol, and myristyl alcohol).

  Examples of silicone include the aforementioned silicone compounds and cyclic silicones (such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane).

  As the polyoxyalkylene compound, polyoxypropylene glycol having a number average molecular weight of 950 to 4000 can be used.

  In addition to these, oily components (b) include substances extracted from animals or plants and hydrogenated products thereof (avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, Egg yolk oil, sesame oil, persic oil, wheat germ oil, sasanqua oil, castor oil, flaxseed oil, safflower oil, cottonseed oil, eno oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnagiri oil, Japan Kiri oil, jojoba oil, germ oil, cocoa butter, coconut oil, horse fat, hydrogenated coconut oil, palm oil, beef tallow, sheep fat, hydrogenated beef tallow, palm kernel oil, pork tallow, beef bone fat, owl kernel oil, hydrogenated oil Beef tallow, squalene, squalane, and other terpenes).

From the viewpoint of dispersion stability, the oil component (b) is preferably a hydrocarbon oil and silicone, more preferably a hydrocarbon oil having a kinematic viscosity of 1 to ²⁰ mm ² / s at 40 ° C., and a kinematic viscosity at 25 ° C. silicone but 1 to 50 mm ² / s, particularly preferably a kinematic viscosity at 40 ° C. is a hydrocarbon oil 1 to 20 mm ² / s.

  These hydrocarbon oils and silicones can be easily obtained from the market, and trade names are exemplified below.

<Hydrocarbon oil> The number in parentheses following the trade name is the kinematic viscosity mm ² / s at 40 ° C.
IP solvent 1016 (0.5), IP solvent 2028 (2), and IP solvent 2835 (12) (Idemitsu Kosan Co., Ltd.);
Cosmo SC22 (21), Cosmo SP10 (10), Cosmo RC Spindle Oil (10), Cosmo RB Spindle Oil (15), Cosmo Neutral 150 (32), Cosmo Pure Spin G (21), Cosmo Pure Spin E (5) Cosmo White P60 (60), Cosmo White P120 (120), Cosmo White P200 (200), and Cosmo White P350P (250) (Cosmo Oil Lubricants Co., Ltd., “Cosmo” is a registered trademark of Cosmo Oil Co., Ltd. .);
Nisseki Super Oil C (93), Nisseki Super Oil D (141), Nisseki Super Oil B (54), Nisseki Polybutene LV-7 (12), Nisseki Polybutene LV-50 (110), Nisseki Polybutene LV-100 (200) and Nisseki Polybutene LV-150 (3500) (JX Nippon Mining & Energy Corporation);
Stanol 43N (27), stanol 52 (56), stanol 69 (145), stanol 35 (9), and stanol LP35 (11) (Esso Petroleum Corporation);
Fukkor NT100 (21), Fukkor NT150 (28), Fukkor NT200 (39), Fukkor NT60 (10), and Fukkor ST Machine (9) (Fujikosan Co., Ltd., “Fukkor” is a registered trademark of Nippon Oil Corporation. is there.);
Pearl Ream 4 (3), Pearl Ream EX (10), and Pearl Ream 6 (20) (manufactured by NOF Corporation, “Pearl Ream” is a registered trademark of NOF Corporation);
Exol series and Isopar series (Exxon Mobil Chemical Company);
Shellsol series (Shell Chemical Co., Ltd.); Nissan Polybutene and NA Solvent Series (manufactured by NOF Corporation, “Nissan” is a registered trademark of NOF Corporation), etc.

<Dimethylpolysiloxane>
KF-96-10cs, KF-96-20cs, KF-96-30cs, KF-96-50cs, KF-96-100cs, KF-96-200cs, KF-96-300cs, KF-96-350cs, KF- 96-500cs, KF-96-1,000cs, KF-96-3,000cs, KF-96-5,000cs, KF-96H-6,000cs, KF-96H-10,000cs, KF-96H-12 500 cs, KF-96H-30,000 cs, KF-96H-50,000 cs, KF-96H-60,000 cs, and KF-96H-100,000 cs {Shin-Etsu Chemical Co., Ltd .; end of trade name (just before cs) The number described in represents dynamic viscosity, for example, “10” is 10 mm ² / s. };
SH200 C Fluid 10 cs, SH200 C Fluid 20 cs, SH200 C Fluid 50 cs, SH200 C Fluid 100 cs, SH200 C Fluid 200 cs, SH200 C Fluid 350 cs, SH200 C Fluid 500 cs, SH200 C Fluid 500 cs, SH200 C Fluid 500 cs C Fluid 5,000cs, SH200H C Fluid 10,000cs, SH200H C Fluid 1250,000cs, SH200H C Fluid 30,000cs, SH200H C Fluid 60,000cs, SH200H C Fluid 100,000cs {Toray Dow Corning Silicone Stock Made by company; number at the end of product name (immediately before cs) represents kinematic viscosity. , "10" is a 10mm ² / s. }; And TSF451-10, TSF451-20, TSF451-30, TSF451-50, TSF451-100, TSF451-200, TSF451-300, TSF451-350, TSF451-500, TSF451-1000, TSF451-1500, TSF451-2000 , TSF451-3000, TSF451-5000, TSF451-6000, TSF451H-1M, TSF451H-12500, TSF451H-2M, TSF451H-3M, TSF451H-5M, TSF451H-6M, and TSF451H-10M {Momentive Performance Materials Japan Made by a limited liability company; the number described at the end of the trade name represents the kinematic viscosity, for example, “10” is 10 mm ² / s. Note that M represents 10,000, for example, 1M is 10,000 mm ² / s. }etc

  The dispersion stabilizer of the present invention can be obtained by methods such as the following <Production Method 1> to <Production Method 3>.

<Manufacturing method 1>
A method of dispersing the amphiphilic particles (a) in the oily component (b).

<Manufacturing method 2>
After crushing the hydrophobized silica fine particle oil component dispersion to obtain a dispersion containing the amphiphilic particles (a) and the oil component (b), the oil component (b) is added to the dispersion, or A method of adjusting the concentration by concentrating this dispersion.

<Manufacturing method 3>
A method of crushing a hydrophobized silica fine particle oil component dispersion to obtain a dispersion containing amphiphilic particles (a) and an oil component (b), and then using this dispersion as it is.

  Concentration can be performed by a known method such as a method using a depressurizable reaction vessel equipped with a heating device and a stirring device, a rotary evaporator, or the like.

  Among these production methods, <Production Method 3> is preferred, and more preferably, a dispersion step of dispersing dry hydrophilic silica fine particles in the oily component (b) to obtain a hydrophilic silica fine particle oily component dispersion, Included in the surface modification step of surface-modifying dry hydrophilic silica fine particles dispersed in hydrophilic silica fine particle oil component dispersion to obtain hydrophobized silica fine particle oil component dispersion, and hydrophobized silica fine particle oil component dispersion It is a manufacturing method including the crushing process which crushes the hydrophobized silica fine particles and obtains the amphiphilic particles (a).

  In the dispersion stabilizer of the present invention, the content (% by weight) of the amphiphilic particles (a) is preferably 0.1 to 10, more preferably 0.5 to, based on the weight of the oil component (b). 8, particularly preferably 1-5. Within this range, the dispersion stability is further improved.

  The dispersion stabilizer of the present invention is excellent in dispersion stability, particularly excellent in pigment dispersion stability. Therefore, it can be used as a dispersion stabilizer for suspension / emulsion polymerization, a dispersion stabilizer for textile industry, a dispersion stabilizer for ink, a dispersion stabilizer for paint, a dispersion stabilizer for plastics, a dispersion stabilizer for agrochemical industry, and the like.

  In the dispersion stabilizer of the present invention, other components (for example, a diluent, an antibacterial agent, a light stabilizer, a viscosity modifier, etc.) can be blended within a range that does not impair the effect.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to this. Unless otherwise specified, parts means parts by weight.

  M values of the amphiphilic particles (a) obtained in Examples 1 to 8 and the hydrophobized silica fine particles of Comparative Examples 1 to 3 were measured by the following method.

<Measurement of M value>
0.2 g of measurement sample (amphiphilic particles (a) obtained in Examples 1 to 8 or hydrophobized silica fine particles of Comparative Examples 1 to 2) was added to 50 mL of ion-exchanged water in a beaker having a capacity of 250 mL, While constantly stirring the liquid in the beaker with a magnetic stirrer, methanol (Kanto Chemical Co., Ltd., reagent special grade, the same applies hereinafter) is gradually dropped into the beaker along the wall of the beaker. The dropwise addition of methanol was continued until suspended in ion exchange water. The drop amount (g) of methanol at the time when the whole amount of the measurement sample was suspended was recorded, and the M value was calculated from the following formula.

(M value) = 100 × (Methanol dropping amount: g) / {(Methanol dropping amount: g) +50}

<Example 1>
Oily component (b1) {100 parts of isoparaffin having a kinematic viscosity of 1 mm ² / s at 40 ° C. (trade name: IP Solvent 1620) manufactured by Idemitsu Kosan Co., Ltd.} and dry hydrophilic silica fine particles (p1) {trade name Aerosil 130 (BET The specific surface area by the method is 130 m ² / g)} 5 parts is put into a triaxial planetary mixer (planetary dispa manufactured by Asada Tekko Co., Ltd.) equipped with a pressure reducing device and a heating device, and stirred and dispersed (low speed) under reduced pressure (approximately 5 kPa) for 60 minutes. Stirring blade: 50 rpm, high speed stirring blade: 3000 rpm) to obtain a hydrophilic silica fine particle oil component dispersion (hd1).

  Subsequently, the hydrophobizing agent (m1) {hexamethyldisilazane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name) while continuing stirring (low-speed stirring blade; 50 rpm, high-speed stirring blade; 3000 rpm) at normal pressure (approximately 101 kPa) HMDS-3)} 0.15 part (3% by weight with respect to the weight of the dry hydrophilic silica fine particles), and hydrophobization treatment is carried out by continuing stirring for 60 minutes to obtain a hydrophobized silica fine particle oil component dispersion (Pd1) was obtained.

  Thereafter, the mixture was heated to 100 ° C. with continuous stirring (low-speed stirring blade: 50 rpm, high-speed stirring blade: 4000 rpm) at normal pressure (approximately 101 kPa), stirred at that temperature for 60 minutes, and then continued stirring at room temperature. The dispersion stabilizer (q1) of the present invention containing amphiphilic particles (a1) was obtained by crushing by cooling to (25 ± 3 ° C., hereinafter the same).

A dispersion stabilizer (q1) 5 g and n-hexane (Kanto Chemical Co., Ltd., reagent grade 1) 100 g were put into a glass container with a lid with a capacity of 100 mL and stirred by shaking up and down for 30 seconds, and then 6 hours. The mixture was allowed to stand at room temperature, and the transparent supernatant layer was removed with a dropper. Subsequently, the remaining lower layer was placed in a 40-mL sample tube, and solid-liquid separation was performed by centrifugation (rotation speed: 4000 rpm, time; 10 minutes) to remove the precipitate, and warm air adjusted to 130 ± 5 ° C. The mixture was heated and dried for 3 hours in an oven to obtain amphiphilic particles (a1).
The amphiphilic particles (a1) had an M value of 13, and a volume average particle size of 0.2 μm.

<Example 2>
“Oil component (b1)” was changed to “Oil component (b2) {hydrogenated polybutene having a kinematic viscosity of 10 mm ² / s at 40 ° C. (trade name: Pearl Ream EX)}”, “Hydrophilic silica fine particles (p1) 5 parts” was changed to “Dry hydrophilic silica fine particles (p2) {trade name Aerosil 50 (specific surface area 50 m ² / g by BET method)} 8 parts”, “hydrophobizing agent (M1) 0.15 part "is" hydrophobizing agent (m2) {methyltrimethoxysilane (trade name KBM-13, manufactured by Shin-Etsu Chemical Co., Ltd.)} 0.4 part (based on the weight of the dry hydrophilic silica fine particles) The dispersion stabilizer (q2) and amphiphilic particles (a2) of the present invention were obtained in the same manner as in Example 1 except that the content was changed to “5 wt%)”.
The amphiphilic particles (a2) had an M value of 15 and a volume average particle size of 0.1 μm.

<Example 3>
“Oil component (b1)” was changed to “Oil component (b3) {liquid paraffin having a kinematic viscosity of 20 mm ² / s at 40 ° C. (trade name Cosmo White P120 manufactured by Cosmo Oil Lubricants Co., Ltd.)}” “Hydrophilic silica fine particles (p1) 5 parts” was changed to “Dry hydrophilic silica fine particles (p3) {trade name Aerosil 300 (specific surface area 300 m ² / g by BET method)} 1 part”, “hydrophobizing agent In the same manner as in Example 1, except that (m1) 0.15 part ”was changed to“ hydrophobizing agent (m1) 0.01 part (1% by weight based on the weight of the dry hydrophilic silica fine particles) ”. An inventive dispersion stabilizer (q3) and amphiphilic particles (a3) were obtained. The amphiphilic particles (a3) had an M value of 5 and a volume average particle size of 0.3 μm.

<Example 4>
“Oil component (b1)” was changed to “Oil component (b5) {liquid paraffin having a kinematic viscosity of 9 mm ² / s at 40 ° C. (trade name Cosmo White P60) manufactured by Cosmo Oil Lubricants Co., Ltd.}}” “Dry hydrophilic silica fine particles (p1) 5 parts” was changed to “dry hydrophilic silica fine particles (p5) {trade name HDK T125 (specific surface area 125 m ² / g by BET method) 5 parts”, “hydrophobizing agent ( The present invention was carried out in the same manner as in Example 1, except that “m1) 0.15 part” was changed to “hydrophobizing agent (m1) 0.1 part (2% by weight based on the weight of the dry hydrophilic silica fine particles)”. Dispersion stabilizer (q4) and amphiphilic particles (a4) were obtained. The M value of the amphiphilic particles (a4) was 7, and the volume average particle diameter was 0.2 μm.

<Example 5>
“Oil component (b1)” was changed to “Oil component (b5) {dimethylpolysiloxane having a kinematic viscosity of 50 mm ² / s at 25 ° C. (trade name: KF-96-50cs) manufactured by Shin-Etsu Chemical Co., Ltd.}}” “5 parts of dry hydrophilic silica fine particles (p1)” was changed to “10 parts of dry hydrophilic silica fine particles (p2)”, and “hydrophobizing agent (m1) 0.15 parts” was changed to “hydrophobizing agent ( m3) 0.07 parts (0.7% by weight based on the weight of the dry hydrophilic silica fine particles) ”, except that the dispersion stabilizer (q5) and amphiphilic property of the present invention were the same as in Example 1. Particles (a5) were obtained. The amphiphilic particles (a5) had an M value of 1 and a volume average particle size of 0.5 μm.

<Example 6>
Oily component (b6) {100 parts liquid paraffin having a kinematic viscosity of 50 mm ² / s at 40 ° C. (trade name Cosmo White P260, manufactured by Cosmo Oil Lubricants Co., Ltd.)} and dry hydrophilic silica fine particles (p5) {trade name Aerosil 200 (Specific surface area by BET method 200 m ^{2 /} g)} 0.5 part is put into a stainless steel mixing vessel equipped with a heating device, and a high-speed rotating centrifugal radiation stirrer equipped with a sawtooth disk impeller having a diameter of about 4 cm (Primics Co., Ltd.) The dispersion process was carried out by stirring and dispersing at 4000 rpm for 60 minutes at normal pressure (approximately 101 kPa) using a TK homomixer. Subsequently, while continuing stirring, 0.05 part of hydrophobizing agent (m1) (10% by weight with respect to the weight of the dry hydrophilic silica fine particles) was added, and stirring was continued for 60 minutes. The dispersion stabilizer (q6) of the present invention was obtained by heating to 100 ° C., carrying out the hydrophobizing step while maintaining stirring at that temperature for 60 minutes, and cooling to room temperature while continuing stirring.
The amphiphilic particles (a6) obtained in the same manner as in Example 1 except that “dispersion stabilizer (q1) 5 g” was changed to “dispersion stabilizer (q6) 5 g” had a volume average particle of 20, The diameter was 0.1 μm.

<Example 7>
“Oil component (b6)” was changed to “Oil component (b7) {dimethylpolysiloxane having a kinematic viscosity of 2 mm ² / s at 25 ° C. (trade name: KF-96L-2cs) manufactured by Shin-Etsu Chemical Co., Ltd.}” In addition, the dispersion stabilizer of the present invention (in the same manner as in Example 6) except that “dry hydrophilic silica fine particles (p5) 0.5 part” was changed to “dry hydrophilic silica fine particles (p2) 10 parts”. q7) and amphiphilic particles (p7) were obtained. The amphiphilic particles (p7) had an M value of 1 and a volume average particle size of 1 μm.

<Example 8>
“Oil component (b6)” was changed to “Oil component (b4)”, “Dry hydrophilic silica fine particles (p5) 0.5 part” was changed to “Dry hydrophilic silica fine particles (p5) 7 parts” In other words, the “hydrophobizing agent (m1) 0.05 part” was changed to “hydrophobizing agent (m1) 0.1 part (1.4% by weight with respect to the weight of the dry hydrophilic silica fine particles)”, In the same manner as in Example 6, a dispersion stabilizer (q8) and amphiphilic particles (p8) of the present invention were obtained. The amphiphilic particles (p8) had an M value of 20, and a volume average particle size of 0.05 μm.

<Comparative Example 1>
Precipitating method hydrophilic silica particles (p6) {Precipitating method silica Nipsil AY-200 (specific surface area by BET method 300 m ² / g)} 100 parts were put into a Henschel mixer with a heater, hydrophobizing agent while stirring at low speed (750 rpm) (M4) 8 parts were sprayed. Next, the Henschel mixer was rotated at a high speed (2000 rpm) for 15 minutes at a room temperature of 20 to 25 ° C., and mixed uniformly. Next, the Henschel mixer was heated with a heater, and heat treatment was performed at 230 ° C. for 3 hours to obtain hydrophobized silica fine particles (hp1). Subsequently, 15 parts of the hydrophobized silica fine particles (hp1) and 100 parts of the oil component (b2) were added at 25 ± 3 ° C. with a saddle type feather stirrer (manufactured by Yamato Scientific Co., Ltd., Three-One Motor BL1200, the same applies hereinafter). By stirring for 15 minutes, a comparative dispersion stabilizer (hq1) was obtained.
The hydrophobized silica fine particles (hp1) had an M value of 50 and a volume average particle size of 11 μm.

<Comparative example 2>
Hydrophobized silica fine particles (hp2) {Dry-hydrophobic silica fine particles obtained by hydrophobizing dry hydrophilic silica fine particles by a vapor phase method (product name Aerosil R976, manufactured by Nippon Aerosil Co., Ltd.)} and 90 parts of ethanol in a cocoon-shaped wing type stirring The resulting mixture was stirred at 25 ± 3 ° C. for 15 minutes to obtain a comparative dispersion stabilizer (hq2).
The hydrophobized silica fine particles (hp2) had an M value of 40 and a volume average particle size of 0.3 μm.

<Comparative Example 3>
A comparative dispersion stabilizer (hq3) was obtained in the same manner as in Comparative Example 2, except that “90 parts of ethanol” was changed to “90 parts of oily component (b5)”.

  1 obtained by dispersing 1 part of the amphiphilic particles (a1 to a8) obtained in Examples 1 to 8 in 99 parts of isopropanol using an ultrasonic disperser (UP400 manufactured by Heilscher) at an output of 70% for 1 minute. When 0.02 g of a weight% dispersion was added to a test tube containing 5 mL of ion-exchanged water and 5 mL of n-hexane and allowed to stand for 60 minutes, the amphoteric medium particles were dispersed at the interface between the ion-exchanged water and n-hexane. A uniform aggregate layer was formed, and the upper and lower layers were clean layers containing no amphiphilic particles. From this, it is considered that the particle surface is divided into a hydrophilic surface and a hydrophobic surface.

  1 part by weight of dispersion 1 obtained by dispersing 1 part of hydrophobized silica fine particles (hp1 and hp2) used in Comparative Examples 1 to 99 parts of isopropanol for 1 minute at an output of 70% using an ultrasonic disperser 0 0.02 g was added to a test tube containing 5 mL of ion-exchanged water and 5 mL of n-hexane and allowed to stand for 60 minutes. The particles were dispersed in the n-hexane layer, and the entire n-hexane layer became cloudy for 2 hours. Later, agglomerates of hydrophobic inorganic fine particles were formed at the interface between ion-exchanged water and n-hexane. From this, it is considered that the particle surface is not divided into a hydrophilic surface and a hydrophobic surface.

<< Evaluation of dispersion stability >>
A pigment dispersion composition was prepared using the dispersion stabilizers (q1 to q8) of the present invention obtained in Examples 1 to 8 and the comparative dispersion stabilizers (hq1 to hq3) obtained in Comparative Examples 1 to 3, The dispersion stability of the pigment was evaluated.

<< Creation of pigment dispersion composition >>
Homogenizer (Hi-Flex Disperser HG-92G made by Taitec Co., Ltd., etc.) equipped with a sawtooth disc impeller in a glass container having an inner diameter of 40 mm and a capacity of 170 mL at a time. The pigment dispersion composition (cd1 to cd8) using the dispersion stabilizer of the present invention and the pigment dispersion composition using the comparative dispersion stabilizer are stirred at 4000 rpm for 15 minutes at 4000 rpm. (Hcd1 to hcd3) were prepared.

  In addition, the numerical value corresponding to each component in Table 1 and Table 2 represents parts by weight, and “pigment fine particles (c1)” are hydrophilic inorganic pigment fine particles made of titanium oxide (manufactured by Sakai Chemical Industry Co., Ltd., trade name R— 680), “pigment fine particles (c2)” are hydrophobic inorganic pigment fine particles (manufactured by Mitsubishi Chemical Corporation, MA-100) made of carbon black, and “pigment fine particles (c3)” are organic made of anthraquinone pigments. Pigment fine particles (Mitsubishi Chemical Co., Ltd., trade name: Diaresin Blue K) are used. “Pigment fine particles (c4)” are polymer fine particles made of crystalline cellulose (Alfa Aesar, trade name: Cellulose, Microcrystalline line). Agent (d1) ”is liquid isoparaffin (ExxonMobil Chemical Co., trade name Isopar G),“ Diluent (d2) ”. "Represents a propylene glycol monomethyl ether (manufactured by Daicel Chemical Industries, Ltd., trade name MMPG).

<Observation of pigment dispersion>
About each pigment dispersion composition obtained above, the pigment dispersion state (degree of aggregation of pigment fine particles) after standing for 1 hour and standing for 12 hours was visually observed using an optical microscope (400 times). The pigment dispersion state after 1 hour of standing was regarded as initial dispersibility, and the pigment dispersion state after standing for 12 hours was regarded as dispersion stability, and each was evaluated according to the following criteria. The results are shown in Tables 1 and 2 .

Scoring criteria No aggregation; ◎
There is slight aggregation; ○
There is very much aggregation; ×

  The pigment dispersion composition (cd1 to cd8) using the dispersion stabilizer of the present invention has an initial dispersibility and dispersion stability as compared with the pigment dispersion composition (hcd1 to hcd3) using a comparative dispersion stabilizer. It was confirmed that it was remarkably superior.

  The dispersion stabilizer of the present invention has high dispersion stability, a dispersion stabilizer for suspension / emulsion polymerization, a dispersion stabilizer for textile industry, a dispersion stabilizer for ink, a dispersion stabilizer for paints, a dispersion stabilizer for plastics, an agrochemical It can be used as an industrial dispersion stabilizer.

Claims (3)

A dispersion stabilizer comprising amphiphilic particles (a) and an oil component (b),
The amphiphilic particles (a) are obtained by surface-modifying dry hydrophilic silica fine particles having a hydrophilic surface and a hydrophobic surface and having a BET specific surface area of 50 to 300 m ² / g with a hydrophobizing agent, A dispersion stabilizer characterized by being amphiphilic particles having an M value of 1 to 20. The dispersion stabilizer according to claim 1, wherein the amphiphilic particles (a) have a volume average particle diameter of 0.05 to 1 µm. A method for producing the dispersion stabilizer according to claim 1, comprising:
A dispersion step in which dry hydrophilic silica fine particles are dispersed in the oil component (b) to obtain a hydrophilic silica fine particle oil component dispersion;
A surface modification step for obtaining a hydrophobized silica fine particle oil component dispersion by surface-modifying dry hydrophilic silica fine particles dispersed in the hydrophilic silica fine particle oil component dispersion; and included in the hydrophobized silica fine particle oil component dispersion The manufacturing method characterized by including the crushing process which crushes the hydrophobized silica microparticles | fine-particles obtained and obtains an amphiphilic particle (a).