JP6195718B2 - Method for producing magnesium composite fine particles - Google Patents

Description

  The present invention relates to magnesium-based composite fine particles and a method for producing the same.

  In recent years, inorganic fillers are often used as additives in order to improve the physical properties of plastics. The purpose of the addition includes, for example, various aspects such as improvement of thermal conductivity, reduction of linear expansion coefficient, provision of flame retardancy, improvement of gas barrier properties and the like.

  When these inorganic fillers are used as an additive for plastics, turbidity may occur in the resulting resin molding. This is due to the difference in refractive index between the plastic and the inorganic filler, as well as the fact that light scattering occurs due to the particle size of the inorganic filler being larger than the wavelength of light (Non-patent Document 1). Therefore, in applications that require colorless transparency such as lenses, it is necessary to control the particle size of the filler to a nano-order level.

  As represented by gold or silver, some inorganic filler materials develop color when finely divided. This is due to the plasmon absorption of the material, the inherent band gap, etc. (Patent Document 1). For this reason, silicon oxide, titanium oxide, zinc oxide, aluminum oxide, calcium oxide, magnesium oxide, magnesium hydroxide, and the like are preferred as inorganic fillers that impart colorless transparency.

  Among these inorganic fillers, in particular, magnesium hydroxide has a high effect of imparting flame retardancy, and is known to be useful as an additive to plastics (Patent Document 2). For example, in applications such as electronic material substrates, there is a risk of ignition due to accumulation of heat generated during use, so it is necessary to impart flame retardancy, so magnesium hydroxide is used for the purpose of flame retardancy. Added to plastic.

  Magnesium oxide is known to have a very high thermal conductivity and is effective as a heat dissipation material used for an electronic material substrate. Moreover, since magnesium is excellent in lightness among metal elements, when it is used as an additive to plastics, weight reduction of a molded product can be expected. If the plastic molded product can be reduced in weight, it can contribute not only to transportation but also to energy saving during use.

JP2008-88296 Japanese Patent Publication 07-04461

Supervision of “Transparent Resins in the Light Age”: Fumio Ide, issued on June 30, 2004, Publisher: Kenji Tsuji, Publisher: CMC Corporation, p. 14-15

  As described above, although fine particles of magnesium hydroxide or magnesium oxide are used as plastic additives, there is room for improvement in dispersibility. That is, the smaller the particle diameter, the stronger the cohesion force between the particles, and the aggregation becomes remarkable especially in the nano-order. For this reason, if it is possible to give the magnesium hydroxide particles and the like superior dispersibility than before, a predetermined effect can be obtained with a smaller addition amount, and as a result, the resin characteristics can be improved more effectively. Become.

  Therefore, the main object of the present invention is to provide magnesium-based fine particles that are particularly excellent in dispersibility despite being nano-order fine particles.

  As a result of intensive studies in view of the problems of the prior art, the present inventor has found that magnesium-based fine particles having a specific configuration can achieve the above object, and have completed the present invention.

That is, the present invention relates to the following method for producing magnesium-based composite fine particles.
1. Fine particles having an average particle size of 500 nm or less,
(1) a) containing at least one magnesium component of magnesium oxide and magnesium hydroxide, and b) an organic component,
(2) The organic component includes a compound having two or more hydroxyl groups,
(3) The content of the organic component is 0.2 to 20% by weight.
A method for producing a magnesium-based composite fine particle , characterized in that
1) magnesium salt, 2) a base and 3) a compound having two or more hydroxyl groups, viewed including the step of obtaining a reaction product by reacting in the liquid phase,
The compound having two or more hydroxyl groups is 1) glycerol or 2) an ester compound of glycerol.
A method for producing a magnesium-based composite fine particle.
2. Item 2. The production method according to Item 1, wherein the ester compound is an ester compound of glycerin and an aliphatic monocarboxylic acid having 4 to 18 carbon atoms.
3. Item 2. The method according to Item 1, wherein the average particle size of the fine particles is 200 nm or less.
4). Item 2. The production method according to Item 1 , wherein the magnesium salt is an organic acid salt of magnesium.
5. Item 2. The production method according to Item 1 , wherein the base is a metal alkoxide.
6). Item 2. The production method according to Item 1, further comprising a step of heat-treating the reaction product.
7). Item 7. The method according to Item 6, wherein the heat treatment temperature is 270 to 330 ° C.
8). Item 2. The production method according to Item 1, wherein the solvent in the liquid phase is a polar organic solvent.
9. Raw material obtained by dissolving or dispersing 1) a raw material solution obtained by dissolving or dispersing a magnesium salt in a polar organic solvent, 2) a base, and 3) glycerin or an ester compound of glycerin in a polar organic solvent. The manufacturing method of said claim | item 1 performed by mixing a liquid.

  According to the magnesium-based composite fine particles of the present invention, since the magnesium component and the organic component are contained in the particles at a predetermined ratio, high dispersibility can be exhibited even though the particles are 500 nm or less. That is, high dispersibility can be exhibited as a powder composed of magnesium-based composite fine particles. For this reason, as a result of being able to disperse effectively by adding to a resin or the like, the original physical properties of the resin or the like can be derived, and a reduction in the addition amount can also be expected.

  Moreover, according to the manufacturing method of this invention, since it makes it react in a liquid phase using a specific starting material, the magnesium type composite fine particle of this invention can be manufactured with a comparatively high yield. For this reason, it is suitable for manufacture on an industrial scale.

2 is a transmission electron micrograph (× 50,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Example 1. FIG. 3 is a transmission electron micrograph (× 50,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Example 2. FIG. 4 is a transmission electron micrograph (× 50,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Example 3. FIG. 4 is a transmission electron micrograph (× 100,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Example 4. FIG. 6 is a transmission electron micrograph (× 200,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Example 5. FIG. 6 is a transmission electron micrograph (× 200,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Example 6. FIG. 6 is a transmission electron micrograph (× 200,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Example 7. FIG. 4 is a transmission electron micrograph (× 50,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Comparative Example 2. FIG. 6 is a transmission electron micrograph (× 50,000) showing the particle morphology of magnesium hydroxide fine particles obtained in Comparative Example 5. 6 is a transmission electron micrograph (× 100,000) showing the particle morphology of magnesium oxide fine particles obtained in Example 8. FIG. 2 is a result of X-ray diffraction analysis of magnesium hydroxide fine particles obtained in Example 1. FIG. 3 is a result of X-ray diffraction analysis of magnesium hydroxide fine particles obtained in Example 2. FIG. 4 is an X-ray diffraction analysis result of magnesium hydroxide fine particles obtained in Example 3. FIG. 4 is a result of X-ray diffraction analysis of magnesium hydroxide fine particles obtained in Example 4. 6 is a result of X-ray diffraction analysis of magnesium hydroxide fine particles obtained in Example 5. FIG. It is a result of X-ray diffraction analysis of the magnesium hydroxide fine particles obtained in Example 6. 4 is an X-ray diffraction analysis result of magnesium hydroxide fine particles obtained in Example 7. FIG. 3 is an X-ray diffraction analysis result of magnesium hydroxide fine particles obtained in Comparative Example 2. FIG. 7 is an X-ray diffraction analysis result of magnesium hydroxide fine particles obtained in Comparative Example 5. FIG. 9 is a result of X-ray diffraction analysis of magnesium oxide fine particles obtained in Example 8. FIG. 2 is a result of measurement of heat loss (TG) of magnesium hydroxide fine particles obtained in Example 1. It is a heat weight loss (TG) measurement result of the magnesium oxide fine particles obtained in Example 8.

1. Magnesium-based composite fine particles The magnesium-based composite fine particles of the present invention (present fine particles) are fine particles having an average particle diameter of 500 nm or less,
(1) a) containing at least one magnesium component of magnesium oxide and magnesium hydroxide, and b) an organic component,
(2) The organic component includes a compound having two or more hydroxyl groups,
(3) The content of the organic component is 0.2 to 20% by weight.
It is characterized by that.

  The average particle diameter of the fine particles of the present invention is usually 500 nm or less, preferably 200 nm or less, and more preferably 100 nm or less. Thus, in the present invention, a powder composed of nano-order fine particles can be provided.

  The fine particles (powder) of the present invention contain a) at least one magnesium component of magnesium oxide and magnesium hydroxide, and b) an organic component.

  Regarding the above a), the fine particles of the present invention contain at least one of magnesium oxide and magnesium hydroxide as a magnesium component. That is, the fine particles of the present invention include 1) containing magnesium oxide alone as the magnesium component, 2) containing magnesium hydroxide alone, and 3) containing both magnesium oxide and magnesium hydroxide.

  In the case of 3) above, the ratio of magnesium oxide and magnesium hydroxide contained in the fine particles of the present invention is not limited, and can be appropriately set according to the use, use conditions, etc. of the fine particles of the present invention. The ratio between the two can be arbitrarily controlled by changing from magnesium hydroxide to magnesium oxide by, for example, heat treatment.

  The proportion of the total amount of magnesium oxide and magnesium hydroxide contained in the fine particles of the present invention is not particularly limited, but is preferably 80 to 99% by weight, and particularly preferably 90 to 99% by weight.

  Regarding the above b), the fine particles of the present invention contain an organic component in addition to the magnesium component. Such organic components include compounds having two or more hydroxyl groups.

  The compound having two or more hydroxyl groups is not particularly limited as long as it imparts desired dispersibility to the fine particles (powder) of the present invention. For example, polyhydric alcohols such as dihydric alcohols and trihydric alcohols are preferably used. be able to. These polyhydric alcohols may be any type of primary alcohol, secondary alcohol, and tertiary alcohol.

  In the present invention, examples of the compound having two or more hydroxyl groups include dihydric alcohols such as methylene glycol, ethylene glycol, propylene glycol, and diethylene glycol; and trihydric alcohols such as glycerin. In the present invention, glycerin can be particularly preferably used.

  Moreover, as a compound which has 2 or more hydroxyl groups, the ester compound of the polyhydric alcohol which has 3 or more hydroxyl groups can be used, for example. For example, in a polyhydric alcohol having three or more hydroxyl groups, an ester compound in which one hydroxyl group is esterified can be used. The ester compound can be produced by an esterification reaction between a polyhydric alcohol and a carboxylic acid. Examples of the carboxylic acid include acetic acid, propionic acid, caprylic acid, capric acid, lauric acid, myristic acid, stearic acid, oxalic acid, succinic acid, acrylic acid, maleic acid, and fumaric acid. Among these, an ester compound of an aliphatic monocarboxylic acid having 4 to 18 carbon atoms and a polyhydric alcohol compound can be suitably used as the carboxylic acid. Examples of such ester compounds include glycerol monocaprate, glycerol monolaurate, glycerol monostearate, glycerol monooleate and the like.

  Furthermore, as a compound having two or more hydroxyl groups, for example, an ether compound of a polyhydric alcohol having three or more hydroxyl groups can be used. For example, in a polyhydric alcohol having 3 or more hydroxyl groups, an ether compound in which one hydroxyl group is etherified can be used. The ether compound can be produced by a dehydration reaction between a polyhydric alcohol and a monoalcohol. Examples of the monoalcohol include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol and the like. Among these, an ether compound with a monoalcohol compound having 4 to 18 carbon atoms can be suitably used as the monoalcohol. Examples of such ether compounds include 3-butoxy-1,2-propanediol, 3-hexyloxy-1,2-propanediol, 3-octyloxy-1,2-propanediol, and 3-octadecyloxy-1. , 2-propanediol and the like.

  In this invention, the organic component should just be contained in this invention microparticles | fine-particles, The position is not limited. For example, it may be contained either inside the fine particles of the present invention or on the surface of the fine particles of the present invention. In particular, in the present invention, it is preferable to be at least part or all of the surface of the fine particles of the present invention. That is, it is preferable that at least part or all of the surface of the fine particles of the present invention is coated with an organic component.

  The proportion of the compound having two or more hydroxyl groups in the organic component is not limited. For example, it is usually 50 to 100% by weight, preferably 80 to 100% by weight, and more preferably 90 to 100% by weight.

  The content of the organic component in the fine particles of the present invention is usually 0.2 to 20% by weight, particularly preferably 0.2 to 10% by weight. When the content of the organic component is less than 0.2% by weight, the fine particles of the present invention cannot exhibit the desired dispersibility. Moreover, when content of an organic component exceeds 20 weight%, there exists a possibility that the original characteristic of a magnesium component may be impaired.

  The fine particles of the present invention contain the magnesium component and the organic component as described above, but may contain other components within a range not impeding the effects of the present invention. Therefore, generally, the total amount of the magnesium component and the organic component preferably occupies 95 to 100% by weight in the fine particles of the present invention, more preferably 99 to 100% by weight, and most preferably 100% by weight. . Examples of the other components include unreacted starting materials used when the fine particles of the present invention are synthesized (excluding organic components).

  The fine particles of the present invention can be used in the form (powder) as they are, or can be used by being dispersed in a solvent. That is, the present invention also includes a dispersion obtained by dispersing magnesium-based composite fine particles in a solvent. By using the dispersion liquid, a coating film containing the fine particles of the present invention can be suitably formed by a method such as coating. The solvent is not limited, and for example, an organic solvent such as a protic solvent, an aprotic solvent, a phenol solvent, an ether solvent, or a carbonate solvent can be suitably used. Among these, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, γ-butyrolactone, 1,3-dimethylimidazolidinone, acetone, cyclohexanone, methanol, ethanol, o-cresol , M-cresol, p-cresol, 1,4-dioxane, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and the like are preferably used. The amount of the magnesium-based composite fine particles dispersed in the dispersion is not limited, but can be appropriately set within a range of about 1 to 30% by weight. The dispersion liquid may contain known additives such as a dispersant and an organic binder as necessary.

2. Method for Producing Magnesium-Based Composite Fine Particles The production method of the present invention is a method for producing magnesium-based composite fine particles (fine particles of the present invention) having 1) a magnesium salt, 2) a base, and 3) two or more hydroxyl groups. It includes a step of obtaining a reaction product by reacting a compound in a liquid phase.

  In the production method of the present invention, 1) a magnesium salt, 2) a base, and 3) a compound having two or more hydroxyl groups are used as starting materials.

  The magnesium salt is not particularly limited. For example, a salt of inorganic acid (mineral acid) such as chloride, carbonate, sulfate, nitrate, phosphate, etc .; organic acid formate, acetate, oxalate In addition, organic metal salts are also included. In the present invention, among these, an organic acid salt of magnesium (particularly a carboxylate) is preferable in terms of solubility in an organic solvent. Therefore, for example, magnesium acetate and magnesium stearate can be preferably used.

  It does not specifically limit as a base, For example, a metal alkoxide, an amine compound, sodium hydroxide, potassium hydroxide etc. can be used. In particular, in the present invention, a metal alkoxide can be preferably used. Examples of the metal alkoxide include sodium methoxide, sodium ethoxide, potassium butoxide and the like. The addition amount of the base is usually about 1 to 10 mol, preferably 2 to 5 mol, per 1 mol of the magnesium salt.

  Examples of the compound having two or more hydroxyl groups include the above-mentioned 1. Can be used. Examples include dihydric alcohols such as methylene glycol, ethylene glycol, propylene glycol, diethylene glycol, and glycerin monoester; trihydric alcohols such as glycerin and ester compounds of polyhydric alcohol compounds having three or more hydroxyl groups. . In the present invention, glycerol, glycerol monoester and the like can be particularly preferably used. Examples of the glycerin monoester include glycerin monocaprate, glycerin monolaurate, glycerin monostearate, and glycerin monooleate.

  In the production method of the present invention, the addition amount of the compound having two or more hydroxyl groups is usually about 1 to 20 mol, preferably 1 to 10 mol, per 1 mol of the magnesium salt.

  In addition to these components, the starting material may contain other components within a range not impeding the effects of the present invention, but it is more preferably composed of the above three components 1) to 3).

  Reactants are produced by reacting these starting materials in the liquid phase. Therefore, an organic solvent can usually be used as the liquid phase. In this case, for example, when the compound having two or more hydroxyl groups is liquid at normal temperature and pressure, it can serve as a starting material and as an organic solvent. Therefore, it may not be necessary to use an organic solvent separately. When an organic solvent is used, the organic solvent that can be used is not particularly limited, but a polar organic solvent such as methanol, ethanol, propanol, or the like can be suitably used. The amount of the organic solvent used is not limited, but it can be adjusted as appropriate so that the concentration of the magnesium salt is usually 0.1 to 1.0 mol / L, particularly 0.2 to 0.8 mol / L. good.

  Moreover, as said reaction conditions, reaction temperature shall be about 5-40 degreeC and reaction pressure should just be under atmospheric pressure normally. The reaction time varies depending on the reaction temperature, starting materials and the like, but is generally about 1 to 24 hours.

The reaction procedure is not particularly limited, for example;
(A) A method in which starting materials are simultaneously added to the liquid phase and reacted.
(B) 1) Magnesium salt, 2) Base, and 3) React by mixing each raw material solution obtained by dissolving or dispersing at least one compound having two or more hydroxyl groups in an organic solvent. Method,
(C) 1) A raw material solution obtained by dissolving or dispersing a magnesium salt in an organic solvent, 2) a base, and 3) a raw material obtained by dissolving or dispersing a compound having two or more hydroxyl groups in an organic solvent. Any of the method of making it react by mixing a liquid may be sufficient.

  In the present invention, the method (C) is particularly preferred from the standpoint that the hydroxyl group of a compound having two or more hydroxyl groups is easily ionized by a base and is easily adsorbed to magnesium hydroxide fine particles or magnesium oxide fine particles. Can be adopted.

  In the production method of the present invention, the reaction product can be further heat-treated. Thereby, part or all of the magnesium hydroxide as the reaction product can be changed to magnesium oxide.

  The heat treatment temperature is not limited, but it is particularly preferable that the heat treatment temperature is a temperature at which part or all of the magnesium hydroxide changes to magnesium oxide and the organic component is not decomposed or vaporized. In other words, when heat treatment is performed, it is preferable to employ an organic component that does not change even at a temperature at which part or all of the magnesium hydroxide changes to magnesium oxide. For example, if glycerin is used as the organic component, heat treatment can be performed at around 300 ° C. (for example, about 270 to 330 ° C.), so that magnesium oxide fine particles can be suitably prepared. The heat treatment atmosphere is usually in the air or an oxidizing atmosphere.

  The features of the present invention will be described more specifically with reference to the following examples and comparative examples. However, the scope of the present invention is not limited to the examples. In addition, the measuring method of each characteristic in an Example and a comparative example and the abbreviation of a compound are as follows.

<Abbreviation of compound>
[Compound having two or more hydroxyl groups]
GLY: Glycerin GLY-Cap: Glycerin monocaprate “Poem M-200” manufactured by Riken Vitamin Co., Ltd.
GLY-Lau: Glycerin monolaurate “Poem M-300” manufactured by Riken Vitamin Co., Ltd.
GLY-Ste: Glycerin monostearate “Riquemar S-100A” manufactured by Riken Vitamin Co., Ltd.
GLY-Ole: Glycerol monooleate “Riquemar XO-100” manufactured by Riken Vitamin Co., Ltd.
[Reaction solvent]
NMP: N-methyl-2-pyrrolidone

<Measurement of organic component content of fine particles (excluding Example 8) (TG measurement)>
The organic component content C of the fine particles was calculated according to the formula (1).
Formula (1) C = A- [B (100-A) / (100-B)]
A: Weight% reduction of fine particles at 100 to 600 ° C. (measured under the following conditions)
B: 30.9% (weight% reduction of dehydration generated when magnesium hydroxide is thermally converted to magnesium oxide)
C: Organic component content (%)
[Measurement condition]
Apparatus: TG / DTA6200 manufactured by SII Nano Technology Co., Ltd.
Measurement temperature: 50-600 ° C
Temperature increase rate: 10 ° C / min
Measurement atmosphere: Nitrogen 200 mL / min

<Measurement of organic component content of fine particles of Example 8 (TG measurement)>
TG measurement was performed under the following conditions, and the weight percent decrease at 100 to 600 ° C. was defined as the organic component content of the fine particles.
[Measurement condition]
Apparatus: TG / DTA6200 manufactured by SII Nano Technology Co., Ltd.
Measurement temperature: 50-600 ° C
Temperature increase rate: 10 ° C / min
Measurement atmosphere: Nitrogen 200 mL / min

<Identification of component (inorganic component) of fine particles>
The components of the prepared fine particles were identified by X-ray diffraction analysis using RINT-2500 manufactured by Rigaku Corporation.
[Measurement condition]
Apparatus: RINT-2500 manufactured by Rigaku Corporation
Scanning mode: Continuous Scanning axis: 2θ / θ
Integration count: 1 scan speed: 4.000 ° / min
Scanning range: 10.000-80.000 °
Sampling width: 0.020 °
θ offset: 0.000 °

<Measurement of average particle diameter>
Twenty or more particles were measured by measurement with a transmission electron microscope (TEM), and the average value was obtained.

<Evaluation of dispersibility>
In addition to NMP so that the content of the obtained fine particles was 10% by weight, a dispersion was prepared by dispersing for 15 minutes using an ultrasonic device. Then, it left still for 1 hour and evaluated by "(circle)" or "x" with the presence or absence of the production | generation of the aggregate visually.
○: Even after standing for 1 hour, the formation of aggregates was not observed, and the dispersion kept colorless and transparent.
X: Formation and sedimentation of aggregates were clearly observed within 1 hour.

Example 1
In a 5 L four-necked flask equipped with a stirrer and a nitrogen inlet tube, 617 g (3.2 mol) of a 28% methanol solution of sodium methoxide as a base, and 147 g (1.6 mol) of GLY as a compound having two or more hydroxyl groups In addition, the solution A was prepared by stirring at room temperature for 1 hour. Separately from this, a solution B in which 343 g (1.6 mol) of magnesium acetate tetrahydrate was dissolved in 1700 g of methanol was prepared. Next, the solution B was added to the solution A with stirring and reacted at room temperature for 20 hours. The precipitated white precipitate was obtained with a centrifuge, and then added to 2 L of methanol with stirring and redispersed. After collecting the white precipitate with a centrifuge, it was added with stirring with 2 L of acetone and redispersed. The white precipitate was collected by centrifugation and then dried at 80 ° C. for 30 minutes in the air to obtain 89 g of fine particles. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of X-ray diffraction analysis is shown in FIG. Moreover, the result of having measured the heating weight loss (TG) of microparticles | fine-particles is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Example 2
91 g of fine particles were obtained in the same manner as in Example 1 except that GLY735 g (8.0 mol) was used as the compound having two or more hydroxyl groups. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of the X-ray diffraction analysis is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Example 3
91 g of fine particles were obtained in the same manner as in Example 1 except that GLY 1473 g (16 mol) was used as the compound having two or more hydroxyl groups. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of the X-ray diffraction analysis is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Example 4
88 g of fine particles were obtained in the same manner as in Example 1, except that GLY-Cap 394 g (1.6 mol) was used as the compound having two or more hydroxyl groups. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of the X-ray diffraction analysis is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Example 5
88 g of fine particles were obtained in the same manner as in Example 1 except that 439 g (1.6 mol) of GLY-Lau was used as the compound having two or more hydroxyl groups. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of X-ray diffraction analysis is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Example 6
89 g of fine particles were obtained in the same manner as in Example 1 except that GLY-St 574 g (1.6 mol) was used as the compound having two or more hydroxyl groups. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of the X-ray diffraction analysis is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Example 7
82 g of fine particles were obtained in the same manner as in Example 1 except that 570 g (1.6 mol) of GLY-Ole was used as the compound having two or more hydroxyl groups. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of the X-ray diffraction analysis is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Comparative Example 1
An attempt was made to produce fine particles by the same method as in Example 1 except that 144 g (1.6 mol) of lactic acid was used instead of GLY, but no precipitate was obtained.

Comparative Example 2
89 g of fine particles were prepared in the same manner as in Example 1 except that 1542 g (8.0 mol) of a 28% methanol solution of sodium methoxide was used as a base and 144 g (1.6 mol) of lactic acid was used instead of GLY. Obtained. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of the X-ray diffraction analysis is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Comparative Example 3
Although it tried to manufacture microparticles | fine-particles by the method similar to Example 1 except having used 307 g (1.6 mol) of citric acid instead of GLY, it was not able to manufacture because citric acid did not melt | dissolve in methanol.

Comparative Example 4
Except that 307 g (1.6 mol) of citric acid was used instead of GLY, 1280 g (3.2 mol) of 10% aqueous solution of sodium hydroxide was used as the base, and the methanol prepared in solution B was changed to 1700 g of water. An attempt was made to produce fine particles by the same method as in Example 1, but no precipitate was obtained.

Comparative Example 5
Implementation was performed except that 307 g (1.6 mol) of citric acid was used instead of GLY, 3840 g (9.6 mol) of 10% aqueous solution of sodium hydroxide was used as the base, and methanol prepared in Solution B was changed to 1700 g of water. In the same manner as in Example 1, 80 g of fine particles were obtained. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium hydroxide as a main component. The result of the X-ray diffraction analysis is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

Example 8
20 g of magnesium hydroxide fine particles obtained by the same method as in Example 1 was placed in a 100 mL beaker and baked at 300 ° C. for 1 hour in the air to obtain 13.4 g of fine particles. The observation result of the obtained fine particles with a transmission electron microscope is shown in FIG. It was confirmed by X-ray diffraction analysis that the obtained fine particles contained magnesium oxide as a main component. The average particle diameter of the fine particles was 6 nm. The result of the X-ray diffraction analysis is shown in FIG. Moreover, the result of having measured the heating weight loss (TG) of microparticles | fine-particles is shown in FIG. Table 1 shows the average particle diameter of fine particles, the organic component content, and the results of dispersion measurement in NMP.

  As is clear from the results in Table 1, the fine particles of Comparative Examples 2 and 5 were as small as an average particle size of 100 nm or less, but the aggregation occurred because the organic component content was as small as 0.1% or less. It turns out that the nature is low. On the other hand, the magnesium-based composite fine particles of the present invention have an organic component content of 0.2 to 10% and a dispersibility in a polar solvent such as NMP even though the average particle size is as small as 100 nm or less. Is also clearly superior.

  That is, the magnesium-based composite fine particles of the present invention contain 0.2% or more and 10% or less of a compound having two or more hydroxyl groups, and are magnesium hydroxide fine particles that simultaneously satisfy a small average particle size and high dispersibility. is there. Further, as shown in Example 8, it can be seen that it is possible to produce fine particles mainly composed of magnesium oxide by heat-treating the magnesium hydroxide fine particles at a predetermined temperature.

  The magnesium-based composite fine particles of the present invention have an average particle diameter of 500 nm or less (particularly 200 nm or less), and can exhibit high dispersibility since they contain a predetermined amount of organic components. Therefore, the molded body obtained by dispersing the magnesium-based composite fine particles of the present invention in a plastic material or the like can be blended with a material such as a lens that requires colorless transparency. In addition, the magnesium-based composite fine particles of the present invention can be used for various applications such as a flame retardant, a heat dissipation material, and a gas barrier property improving material.

Claims (9)

Fine particles having an average particle size of 500 nm or less,
(1) a) containing at least one magnesium component of magnesium oxide and magnesium hydroxide, and b) an organic component,
(2) The organic component includes a compound having two or more hydroxyl groups,
(3) The content of the organic component is 0.2 to 20% by weight.
A method for producing a magnesium-based composite fine particle , characterized in that
1) magnesium salt, 2) a base and 3) a compound having two or more hydroxyl groups, viewed including the step of obtaining a reaction product by reacting in the liquid phase,
The compound having two or more hydroxyl groups is 1) glycerol or 2) an ester compound of glycerol.
A method for producing a magnesium-based composite fine particle. The production method according to claim 1, wherein the ester compound is an ester compound of glycerin and an aliphatic monocarboxylic acid having 4 to 18 carbon atoms. The manufacturing method of Claim 1 whose average particle diameter of microparticles | fine-particles is 200 nm or less. The manufacturing method of Claim 1 whose magnesium salt is an organic acid salt of magnesium. The production method according to claim 1 , wherein the base is a metal alkoxide. The manufacturing method of Claim 1 including the process of heat-processing the reaction product further. The manufacturing method of Claim 6 whose temperature of heat processing is 270-330 degreeC. The production method according to claim 1, wherein the solvent in the liquid phase is a polar organic solvent. Raw material obtained by dissolving or dispersing 1) a raw material solution obtained by dissolving or dispersing a magnesium salt in a polar organic solvent, 2) a base, and 3) glycerin or an ester compound of glycerin in a polar organic solvent. The manufacturing method of Claim 1 performed by mixing a liquid.