阅读说明：本技术 复合材料 (Composite material ) 是由 齐木智秋 横田英之 泽本大介 矢野亨 于 2019-10-24 设计创作，主要内容包括：本发明的课题在于,提供一种在配合于硅酮树脂等中时分散性良好,且物性改良效果大的剥片化层状物质。本发明是一种复合材料,其是通过被覆物质被覆剥片化层状物质的表面而得到的复合材料,其中,被覆物质为具有有机基团的聚硅氧烷化合物,被覆物质相对于剥片化层状物质100质量份的含量为0.1质量份～100质量份。剥片化层状物质的平均厚度为1200nm以下,剥片化层状物质的平均面积为0.1μm～2～500μm～2。(The present invention addresses the problem of providing a delaminated layered material that has good dispersibility when incorporated in a silicone resin or the like, and has a large effect of improving physical properties. The present invention is a composite material obtained by coating the surface of a exfoliated layered substance with a coating substance, wherein the coating substance is a polysiloxane compound having an organic group, and the content of the coating substance is 0.1 to 100 parts by mass with respect to 100 parts by mass of the exfoliated layered substance. The average thickness of the exfoliated layered material is 1200nm or less, and the average area of the exfoliated layered material is 0.1 μm 2 ～500μm 2 。)

1. A composite material obtained by coating the surface of a exfoliated layered substance with a coating substance, wherein the coating substance is a polysiloxane compound having an organic group, and the content of the coating substance is 0.1 to 100 parts by mass per 100 parts by mass of the exfoliated layered substance.

2. The composite material according to claim 1, wherein the exfoliated layered material has an average thickness of 1200nm or less and an average area of 0.1 μm²～500μm²。

3. The composite material according to claim 1 or 2, wherein the polysiloxane compound having an organic group is a polysiloxane compound having a phenyl group, and the phenyl group content is 5% by mass to 70% by mass.

4. A resin composition comprising the composite material according to any one of claims 1 to 3 and a synthetic resin.

5. The resin composition according to claim 4, wherein the synthetic resin is a silicone resin.

Technical Field

The present invention relates to a composite material obtained by coating the surface of a exfoliated layered substance with a polysiloxane compound having an organic group.

Background

Exfoliated graphite such as graphene obtained by exfoliating graphite as a laminated material is used as a conductive aid for an electrode of a secondary battery (for example, see patent document 1), a conductive ink (for example, see patent document 2), a filler for a resin or an elastomer (for example, see patent documents 3 to 4), a gas barrier material (for example, see patent documents 5 to 6), and the like. The layered material is thinned by flaking, and the less the number of layers, the more likely it is to cause aggregation, and therefore, it is difficult to disperse the layered material in the matrix, and sufficient physical properties may not be obtained. In order to improve the cohesiveness and dispersibility in solvents and the like, exfoliated graphite whose surface is coated with a polymer such as polyvinyl alcohol (for example, see patent document 7) has been studied, but the effect of improving the dispersibility when blended in a silicone resin or the like is not sufficient. Further, a method of treating the surface of a layered material with a silane coupling agent in order to improve dispersibility in a resin is also known (for example, see patent document 8), but the silane coupling agent is expensive and an inexpensive method is required.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-060887

Patent document 2: US20170179490

Patent document 3: WO2011/086391

Patent document 4: WO2013/165677

Patent document 5: US20140272350

Patent document 6: WO2016/115377

Patent document 7: US20160200580

Patent document 8: japanese patent laid-open publication No. 2015-040211

Disclosure of Invention

The present invention addresses the problem of providing a delaminated layered material that has good dispersibility when incorporated in a silicone resin or the like, and has a large effect of improving physical properties.

The present inventors have intensively studied the above-mentioned problems, and as a result, they have found that the above-mentioned problems can be solved by coating the surface of a exfoliated layered substance with a specific substance, and have completed the present invention. That is, the present invention is a composite material obtained by coating the surface of a exfoliated layered substance with a coating substance, wherein the coating substance is a polysiloxane compound having an organic group, and the content of the coating substance is 0.1 to 100 parts by mass with respect to 100 parts by mass of the exfoliated layered substance.

The present invention also provides a resin composition containing the composite material and a synthetic resin.

Detailed Description

[ flaking layered substance ]

The layered material as a raw material of the exfoliated layered material used in the present invention has the following layered structure: unit layers formed by strong bonds such as covalent bonds or ionic bonds are stacked mainly via weak van der waals forces. Examples of the layered substance include: graphite, boron nitride, transition metal dichalcogenide, group 13 chalcogenide, group 14 chalcogenide, bismuth chalcogenide, layered metal halide, layered transition metal oxide, layered perovskite oxide, clay mineral, layered silicate, or the like.

Graphites are layered compounds having a unit layer formed of carbon. The graphite product includes, in addition to graphite, expanded graphite obtained by expanding graphite interlayers and graphite oxide obtained by oxidizing graphite with an oxidizing agent.

Boron nitrides are layered substances containing nitrogen and boron as constituent elements, and are Boron Nitride (BN), Boron Carbon Nitride (BCN), and the like.

Transition metal dichalcogenides are layered substances composed of transition metals and chalcogens and have the formula MX₂Wherein M is a transition metal and X is a chalcogen element. Examples of the transition metal include titanium, zirconium, hafnium, vanadium, niobium, chromium, molybdenum, tungsten, technetium, rhenium, nickel, tin, palladium, and platinum. As chalcogens, sulfur, selenium or tellurium can be cited. Examples of the transition metal dichalcogenide include TiS₂、TiSe₂、TiTe₂、HfS₂、HfSe₂、HfTe₂、VTe₂、VSe₂、NbS₂、NbSe₂、NbTe₂、MoS₂、MoSe₂、MoTe₂、WS₂、WSe₂、WTe₂、TcS₂、ReSe₂、ReS₂、ReTe₂、TaS₂、TaSe₂、TaTe₂、PtTe₂And the like.

The group 13 chalcogenide is a layered material composed of gallium or indium as a group 13 element and a chalcogen element, and examples thereof include GaS, GaSe, GaTe, InSe, and the like.

The group 14 chalcogenide is a layered substance composed of germanium, tin or lead as a group 14 element and a chalcogen element, and GeS and SnS are exemplified₂、SnSe₂PbO, etc.

The bismuth chalcogenide is a layered substance composed of bismuth and chalcogen, and Bi is exemplified₂、Se₃、Bi₂Te₃And the like.

The layered metal halide is a layered substance composed of a metal element and a halogen, and may be exemplified by MgBr₂、CdCl₂、CdI₂、AgF₂、AsI₃、AlCl₃And the like.

The layered transition metal oxide is a layered material composed of an oxide or oxysalt of a transition metal such as titanium, manganese, molybdenum, niobium, vanadium, etc., and includes MoO₃、Mo₁₈O₅₂、V₂O₅、LiNbO₂、K₂Ti₂O₅、K₂Ti₄O₉、KTiNbO₅And the like.

The layered metal phosphate is a layered phosphate of titanium, zirconium, selenium, tin, zirconium, aluminum, etc., and includes Ti (HPO)₄)₂、Ce(HPO₄)₂、Zr(HPO₄)₂、AlH₂P₃O₁₀And the like.

As the layered perovskite oxide, KCa is exemplified₂Nb₃O₁₀、KSr₂Nb₃O₁₀、KLaNb₂O₇And the like.

Examples of the clay mineral or layered silicate include: smectites such as montmorillonite, nontronite and saponite; kaoline, pyrophyllite, talc, vermiculite, micas, brittle micas, chlorite, sepiolite, palygorskite, filiform allophane, ferrosilicon, magadiite, kenyaite, and the like.

The exfoliated layered material used in the present invention is obtained by exfoliating the layered material as described above, and means a material having a layered structure in which 1 to several thousand layers are stacked in a unit layer of the layered material. The smaller the number of layers of the exfoliated layered material and the smaller the thickness thereof, the greater the effect of improving physical properties, but the more easily the exfoliated layered material is aggregated. From the viewpoint of such a situation and economy, in the present invention, the average thickness is preferably 0.3nm to 1200nm, more preferably 1.5nm to 400nm, and most preferably 3nm to 200 nm.

The present invention is preferably applied to a exfoliated layered substance which has high cohesiveness and is difficult to disperse in a resin or the like. Examples of the exfoliated layered substance include exfoliated graphite and exfoliated boron nitride. Among them, the present invention is preferably applied to exfoliated graphite and exfoliated boron nitride.

In the present invention, the thickness of the exfoliated layered substance is a thickness in a direction perpendicular to the laminated surface of the exfoliated layered substance, and the average thickness is an average value of thicknesses of any 30 or more exfoliated layered substances. The thickness of the exfoliated layered substance can be measured using, for example, an SEM image obtained by taking an image of the exfoliated layered substance with a scanning electron microscope. The thinnest exfoliated layered material is constituted by only 1 unit layer, but the thickness thereof differs depending on the exfoliated layered material, and is considered to be about 1 nm. For example, in a exfoliated layered material of graphite, a material composed of 1 unit layer is called graphene, and theoretically has a thickness of about 0.335 nm.

If the area of the exfoliated layered material is small, a sufficient effect of improving physical properties may not be obtained, and therefore, it is preferable that the area of the exfoliated layered material is large. However, if the average area is too large, it takes much labor to exfoliate the substance, and therefore the average area of the exfoliated layered substance in the present invention is preferably 0.1 μm²～500μm²More preferably 0.5 μm²～300μm²More preferably 1.0. mu.m²～130μm². In the present invention, the area of the exfoliated layered substance is a projected area when the exfoliated layered substance is viewed in plan, and the average area is an average value of the areas of arbitrary 50 or more exfoliated layered substances. The area of the exfoliated layered substance can be measured, for example, by dropping a thin dispersion of the exfoliated layered substance on a filter paper and taking an image of the exfoliated layered substance by a microscope.

The method for exfoliating the layered material is not particularly limited, and exfoliation may be performed by applying shear force, ultrasonic vibration, cavitation, or the like to the layered material by a known apparatus. Examples of such devices include: media stirring mills such as sand mills, attritors and bead mills; container driving type grinders using balls or rods as media, such as tumbling mills, vibration mills, planetary mills, etc.; jet mills, roller mills, hammer mills, pin mills, high pressure emulsifiers, ultrasonic emulsifiers, and the like. Examples of the high-pressure emulsifying machine include a through-type high-pressure emulsifying machine and an impact-type high-pressure emulsifying machine. The penetration type of the penetration type high-pressure emulsifying machine includes a single nozzle type and a slit nozzle type. Examples of the collision form of the collision type high-pressure emulsifying machine include a form in which a liquid containing a raw material is collided with a plane such as a valve or a spherical surface such as a ball, and a form in which liquids containing raw materials are collided with each other.

When the layered material is exfoliated, any of a wet exfoliation method using a solvent and a dry exfoliation method using no solvent may be used, and the exfoliation method may be selected in combination with the exfoliation method of each apparatus.

As the solvent used in the wet flaking method, an alcohol-based solvent such as methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, or methoxyethanol is preferable because static electricity is not easily charged; ketone solvents such as acetone and methyl ethyl ketone; heterocyclic solvents such as pyridine, piperidine, morpholine, tetrahydrofuran and dioxane; ionic liquids such as 1-ethyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate, dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, and water.

When the layered material is exfoliated, a water-soluble salt may be used in combination. In the flaking step, the solid water-soluble salt acts as a medium for promoting flaking, and the water-soluble salt dissolved in the solvent acts between the layers of the layered material to promote flaking. After flaking, the water-soluble salt can be easily removed by washing with water. Preferred water-soluble salts include sodium chloride, potassium chloride, magnesium chloride, sodium sulfate, potassium sulfate, calcium sulfate, and sodium acetate.

[ polysiloxane Compound having an organic group ]

In the present invention, the polysiloxane compound having an organic group is a general term for a polymer or oligomer having a siloxane bond (Si — O — Si bond) as a main skeleton and having an organic group bonded to a silicon atom. Examples of the organic group of the polysiloxane compound having an organic group used in the composite material of the present invention include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, and an aralkyl group, and these organic groups may have a substituent such as a hydroxyl group, an ether group, an ester group, an epoxy group, a (meth) acryloyloxy group, a carbonyl group, a carboxyl group, an amino group, a thiol group, and a thioether group. The organic group is preferably a methyl group, an ethyl group, a butyl group, a vinyl group, a 2-cyclohexylethyl group, a 2-cyclohexenylethyl group, a phenyl group, a 2-phenylethyl group, a 2-phenylpropyl group, a 2-norbornenylethyl group, a 3-hydroxypropyl group, a 2- (3, 4-epoxycyclohexyl) ethyl group, a 3-glycidyloxypropyl group, a 3-acryloyloxypropyl group, a 3-methacryloyloxypropyl group, a 3- (polyoxyalkylene) propyl group or the like, and is preferably a methyl group, an ethyl group, a vinyl group, or a phenyl group, because the raw materials can be easily obtained. In addition, from the viewpoint of dispersibility in a resin, the organic group of the polysiloxane compound having an organic group is preferably an aryl group such as a phenyl group, or an aralkyl group such as a 2-phenylethyl group or a 2-phenylpropyl group. The organic group may be 1 kind only or a combination of 2 or more kinds, and in the case of a combination of 2 or more kinds, 1 kind is preferably an aryl group or an aralkyl group from the viewpoint of dispersibility in a resin. When a phenyl group is contained as the organic group, the content of the phenyl group in the compound is preferably 5 to 70% by mass, more preferably 6 to 70% by mass, and most preferably 8 to 60% by mass. The content of phenyl groups in the compound can be calculated from the content of repeating units constituting the polysiloxane compound and the content ratio of the repeating units. When the organic group has an aryl group or an aralkyl group other than a phenyl group, the content of the phenyl group is defined to include only a benzene ring portion. When polysiloxane compounds having 2 or more organic groups different in phenyl group content are used in combination, the phenyl group content is set as a mass average value in consideration of the mass ratio of the polysiloxane compounds having organic groups used. In the polysiloxane compound having an organic group, the silicon substituent may be an organic group in its entirety, or a part of the organic group may be substituted with a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, or the like, which is a small number of the organic group.

Since the silicone compound having an organic group is easily volatile if it has a low molecular weight, the silicone compound having an organic group preferably has at least 5 silicon atoms, and preferably 10 or more silicon atoms. The molecular shape of the polysiloxane compound having an organic group may be any of linear, cyclic, branched, cage, ladder (ladder), and the like, or a combination thereof, or may be a molecular shape in which polysiloxane compounds having an organic group are linked to each other by a hydrocarbon group or the like.

[ composite Material ]

The composite material of the present invention has a surface of a exfoliated layered substance coated with a polysiloxane compound having an organic group. In the present invention, the polysiloxane compound having an organic group may cover a part of the surface of the exfoliating layered substance or the entire surface, but preferably covers at least the majority of the surface. Further, the polysiloxane compound having an organic group may continuously cover the surface of the exfoliative layered substance or may intermittently cover the surface.

In the composite material of the present invention, the content of the polysiloxane compound having an organic group is 0.1 to 100 parts by mass with respect to 100 parts by mass of the exfoliated layered substance. When the content of the polysiloxane compound having an organic group is less than 0.1 part by mass, the coating with the polysiloxane compound having an organic group may be insufficient, and when it is more than 100 parts by mass, not only the effect of increasing the amount of the polysiloxane compound according to the amount used may not be obtained, but also the physical properties of the resin or the like may be adversely affected when the composite material of the present invention is added to the resin or the like. The content of the polysiloxane compound having an organic group is preferably 0.2 to 70 parts by mass, more preferably 0.5 to 60 parts by mass, and most preferably 1 to 50 parts by mass, relative to 100 parts by mass of the exfoliating layered substance.

[ method for producing composite Material ]

Examples of the method for coating a exfoliated layered substance with a polysiloxane compound having an organic group include: a method of coating by dispersing and mixing a silicone compound having an organic group and a exfoliating layer material in a solvent (hereinafter referred to as a mixed coating method); a method in which a hydrolyzable silane compound is added to an aqueous dispersion of a delaminated layered substance to cause a hydrolysis-condensation reaction (so-called sol-gel reaction) of the hydrolyzable silane compound, and the resultant polysiloxane compound having an organic group is coated (hereinafter referred to as a sol-gel coating method).

< Mixed coating method >

Since the exfoliated layered material is likely to aggregate to form secondary particles, the coating is insufficient if only the exfoliated layered material is immersed in a solution or dispersion of a polysiloxane compound having an organic group. Therefore, it is preferable to coat the secondary particles of the exfoliated layered material by crushing the secondary particles in a solution or dispersion of the polysiloxane compound having an organic group, or to add the polysiloxane compound having an organic group to a dispersion obtained by crushing the secondary particles of the exfoliated layered material. In order to crush the secondary particles of the exfoliated layered substance, it is necessary to apply a shearing force, ultrasonic vibration, cavitation, or the like to the liquid containing the exfoliated layered substance using a dispersing device. Examples of dispersing apparatuses used for this purpose include: a high-speed rotary shearing type stirrer such as a homogenizing stirrer; media stirring mills such as sand mills, attritors and bead mills; container driving type grinders using balls or rods as media, such as tumbling mills, vibration mills, planetary mills, etc.; colloid mills, high pressure emulsifying machines, ultrasonic emulsifying machines, and the like. Examples of the high-pressure emulsifying machine include a through-type high-pressure emulsifying machine and an impact-type high-pressure emulsifying machine. The penetration type of the penetration type high-pressure emulsifier includes a single nozzle type. Examples of the collision form of the collision type high-pressure emulsifying machine include a form in which a liquid containing a raw material is collided with a plane such as a valve or a spherical surface such as a ball, and a form in which liquids containing raw materials are collided with each other. When a strong shearing force is applied to the exfoliated layered substance, the number of layers, thickness, particle size, and the like of the exfoliated layered substance may decrease compared to before coating.

In the mixed coating method, when the polysiloxane compound having an organic group is added to the dispersion liquid obtained by crushing the secondary particles of the exfoliated layered substance, the polysiloxane compound having an organic group is easily dissolved and dispersed, and therefore, the dispersing apparatus used in the crushing can be used as it is after crushing the exfoliated layered substance.

The solvent used in the mixed coating method may be selected in consideration of ease of removal, safety (toxicity, flammability, chargeability, and the like), and the like, as long as the solvent can dissolve the polysiloxane compound having an organic group by dispersing the polysiloxane compound having an organic group using a dispersing device. Examples of the solvent used in the mixed coating method include: alcohol solvents such as methanol, ethanol, isopropanol, and methoxyethanol; ketone solvents such as acetone and methyl ethyl ketone; water, and the like. The ratio of the exfoliated layered material to the solvent or the solution of the polysiloxane compound having an organic group varies depending on the pulverizing apparatus, but the solvent or the solution of the polysiloxane compound having an organic group is preferably about 200 to 5000 parts by mass with respect to 100 parts by mass of the exfoliated layered material.

After mixing the exfoliating layered substance with the polysiloxane compound having an organic group, the solvent is removed to obtain the composite material of the present invention. The method for removing the solvent is not particularly limited, and a method such as heat drying, drying under reduced pressure, spray drying, freeze drying, or the like, or a combination of these methods may be used. Before the solvent is removed, the excess organic group-containing polysiloxane compound and a part of the solvent may be removed by filtration, centrifugation or the like, if necessary, and then the remaining solvent may be removed. The composite material of the present invention may be pulverized and granulated as necessary.

< Sol-gel coating method >

In the case of the sol-gel coating method, secondary particles of the exfoliated layered substance are also crushed using water as a solvent, and then the hydrolyzable silane compound is subjected to a sol-gel reaction. Examples of the dispersing device used for the crushing include dispersing devices exemplified in the mixed coating method. In the case of the sol-gel coating method, as in the case of the hybrid coating method, when a strong shearing force is applied to the exfoliated layered material by cleavage, the number of layers, thickness, particle diameter, and the like of the exfoliated layered material may be reduced as compared with those before coating.

The hydrolyzable silane compound is a silane compound having a group which generates a silanol (Si — OH) group by hydrolysis, and the silanol group is dehydrated and condensed to generate a siloxane group. The hydrolyzable silane compound may be selected in consideration of the structure of the polysiloxane compound having a hydrolyzable group and an organic group, in addition to the organic group introduced into the polysiloxane compound having an organic group.

Examples of the hydrolyzable group of the hydrolyzable silane compound include: alkoxysilyl groups such as methoxysilyl, ethoxysilyl, propoxysilyl and methoxyethoxysilyl; halosilyl groups such as chlorosilyl and bromosilyl; acyloxysilyl groups such as acetoxysilyl; and aminosilyl groups such as dimethylaminosilyl group and cyclohexylaminosilyl group. Among them, alkoxysilyl groups are preferable, and methoxysilyl groups and ethoxysilyl groups are more preferable, because corrosion to the apparatus is small, hydrolysis reaction is fast, and industrial availability is easy.

In the present invention, the hydrolyzable silane compound is referred to as an M-type silane compound having 3 organic groups and 1 hydrolyzable group, a D-type silane compound having 2 organic groups and 2 hydrolyzable groups, a T-type silane compound having 1 organic group and 3 hydrolyzable groups, and a Q-type silane compound having 4 hydrolyzable groups, depending on the number of the organic groups and the hydrolyzable groups. The structure of the polysiloxane compound having an organic group obtained by the sol-gel reaction is greatly influenced by the number of hydrolyzable groups of the hydrolyzable silane compound used. For example, when only the D-type silane compound is used, a polysiloxane compound having a high molecular weight and a linear organic group can be obtained, and when only the T-type silane compound is used, a cage-like polysiloxane compound having an organic group can be obtained. As the hydrolyzable silane compound used in the sol-gel coating method, a D-type silane compound is preferable in that a coating film of a polysiloxane compound having a high molecular weight and an organic group can be formed on a delaminated layered substance, and when different types of hydrolyzable silane compounds are used in combination, at least 1 is preferably a D-type silane compound. Preferred examples of the D-type silane compound include dimethyldimethoxysilane, dimethyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane.

In the sol-gel coating method, a hydrolyzable silane compound is added to water in which secondary particles of a exfoliated layered substance are broken and dispersed in the state of primary particles, a sol-gel reaction is caused, and a coating of a polysiloxane compound having an organic group is formed on the surface of the exfoliated layered substance. The water used may be water alone or water containing a water-soluble solvent such as methanol, ethanol, or isopropyl alcohol. In addition, in order to promote the reaction, the water used may also contain the following components as catalysts: inorganic acids such as hydrochloric acid, phosphoric acid, and sulfuric acid; organic acids such as formic acid, acetic acid, oxalic acid, citric acid, methanesulfonic acid, benzenesulfonic acid and the like; and inorganic bases such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and ammonia. The temperature of the sol-gel reaction varies depending on the type of the hydrolyzable silane compound, the type and amount of the catalyst, and the like, but is preferably 5 to 50 ℃, and more preferably 8 to 30 ℃.

After the completion of the sol-gel reaction, the reaction mixture is filtered, washed, and dried as necessary, and the drying method is not particularly limited, and a method such as heat drying, reduced pressure drying, spray drying, or freeze drying, or a combination thereof may be used. The composite material of the present invention may be pulverized and granulated as necessary.

The composite material of the present invention has a surface of a exfoliated layered substance coated with a polysiloxane compound having an organic group, and thus does not cause aggregation of the exfoliated layered substance, thereby significantly improving dispersibility in a substrate. This can improve the effect of improving the physical properties of the exfoliated layered material, such as electrical conductivity, heat dissipation, and mechanical properties (impact resistance, bending strength, compression strength, and the like). The composite material of the present invention can be suitably applied to additives for resins such as synthetic resins, elastomers, paints, and the like; and a conductive additive for a battery electrode.

[ resin composition ]

The resin composition of the present invention contains the composite material of the present invention and a synthetic resin. As synthetic resins that can be preferably used in the resin composition of the present invention, there can be mentioned: phenol resin, epoxy resin, melamine resin, urea resin, alkyd resin, PET resin, PBT resin, polycarbonate resin, polyacetal resin, modified polyphenylene ether resin, polyurethane, polyimide amide, polyetherimide, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, fluorine-based resin, ABS resin, AS resin, acrylic resin, silicone, and the like.

When the resin of the resin composition of the present invention is a thermoplastic resin, the composite material of the present invention may be blended in the step of kneading the resin and the additive, as in the case of other additives, or in the case of a thermosetting resin, the composite material of the present invention may be blended in an uncured resin and then the resin may be cured. For example, in the case of a resin composition containing the composite material of the present invention and a silicone resin, the composite material of the present invention may be blended with other additives in an uncured silicone resin composition and then cured by a method such as heating. Examples of the uncured silicone resin composition include: comprising polysiloxane compound having hydrosilyl (SiH) group, having vinyl (CH)₂CH-group) polysiloxane compound and a hydrosilylation catalyst; containing a compound having a methylsilyl group (Si-CH)₃A silicone compound and a peroxide catalyst; a condensation-curable composition comprising a polysiloxane compound having a methylsilyl group, a polysiloxane compound having a vinylsilyl group, and a peroxide catalyst; moisture-curable compositions containing a hydrolysis-condensation type silicone compound, photocurable compositions containing a (meth) acryl-containing silicone compound, and the like.

The amount of the composite material of the present invention to be added varies depending on the kind of resin and the desired physical properties, but is preferably 1 to 150 parts by mass, more preferably 2 to 100 parts by mass, per 100 parts by mass of the synthetic resin.

In the resin composition of the present invention, a silicone resin is preferably used as the resin composition. Such a resin composition is excellent in heat resistance, and thus can be suitably used as, for example, a sealing material for a semiconductor, a heat sink, or the like.

Examples

The present invention will be described in further detail below with reference to examples and comparative examples. However, the present invention is not limited to the following examples and the like.

In the following examples and the like, the average thickness of the exfoliated layered substance is an average value of thicknesses of arbitrary 30 exfoliated layered substances measured using SEM images taken by a scanning electron microscope. The average area of the exfoliated layered substance is an average value of the areas of arbitrary 50 exfoliated layered substances measured using an image obtained by dropping a thin dispersion of the exfoliated layered substance on a filter paper and taking an image of the exfoliated layered substance with a microscope.

Production example 1

According to example 1 described in international publication No. 2013/172350, a exfoliated layered material a1 was prepared from natural graphite. That is, 74 parts by mass of 1-butyl-3-methylimidazolium hexafluorophosphate and 26 parts by mass of polyethylene glycol (product name: polyethylene glycol 20000, manufactured by Fuji film and Wako Junyaku K.K.) were mixed and dissolved by heating, and 10 parts by mass of natural graphite (manufactured by Fuji film and Wako Junyaku K.K.) was dispersed therein. Collecting 0.6g of the dispersion to 0.5cm³The vial (4) was covered, and then the dispersion was irradiated with microwaves of 2450MHz for 30 minutes at 170 ℃ using a microwave synthesizer (Initiator + manufactured by Biotage Japan). Thereafter, the dispersion was filtered, washed with acetone, and dried by heating in an oven, thereby obtaining a exfoliated layered substance a1 derived from natural graphite. The average thickness of the exfoliating layered material A1 was 123nm and the average area was 11.6. mu.m²。

Production example 2

Expanded graphite (commercially available from Ito graphite, Ltd.) was usedName: EC1500) was performed in the same manner as in production example 1 except that natural graphite was replaced with the other, to obtain exfoliated layered material a2 derived from expanded graphite. The average thickness of the exfoliating layered material A2 was 30nm and the average area was 1.4. mu.m²。

Production example 3

A exfoliated layered substance a3 derived from boron nitride was obtained in the same manner as in production example 1, except that boron nitride (manufactured by Aldrich corporation) was used instead of natural graphite. The average thickness of the exfoliating layered material A3 was 183nm and the average area was 10.3. mu.m²。

Examples 1 to 9 and comparative example 1

The exfoliated layered material, the following coating material and a solvent were put into a bead mill (product name: UAM-015, manufactured by shoku industries Ltd.) at the mass ratios shown in Table 1 to crush the secondary particles of the exfoliated layered material, and the solvent was removed by heating and drying under reduced pressure, thereby producing composite materials of examples 1 to 9 and comparative example 1.

In table 1, numerals in parentheses indicate mass ratios, and MEK of the solvent indicates methyl ethyl ketone. Comparative example 1 is an experimental example using polyvinyl alcohol as a coating material, but since it is powdery and insoluble in methyl ethyl ketone, only water is used as a solvent.

< coating Material >

B1: diphenylsiloxane-dimethylsiloxane copolymer

(phenyl content: 31% by mass, product name: PDM-1922, manufactured by Gelest corporation)

B2: phenyl methyl siloxane-dimethyl siloxane copolymer

(phenyl content: 10% by mass, product name: PMM-1015 manufactured by Gelest)

B3: phenyl methyl siloxane polymer

(phenyl content: 56 mass%, product name: PMM-0021, manufactured by Gelest)

B4: silanol terminated diphenylsiloxane-dimethylsiloxane copolymer

(phenyl content: 26% by mass, product name: PDS-1615, manufactured by Gelest Co.)

B5: vinyl terminated diphenylsiloxane-dimethylsiloxane copolymers

(phenyl content: 22% by mass, product name: Andisil SF2430CV, manufactured by AB Specialty Silicones)

C1: polyvinyl alcohol (trade name: PVA217, manufactured by KURARARAY Co., Ltd.)

TABLE 1

[ example 10]

The secondary particles of the exfoliated layered material were crushed using 70 parts by mass of exfoliated layered material A1 and 1400 parts by mass of water, and using a bead mill (trade name: UAM-015, manufactured by shou industries, Ltd.). 147 parts by mass of the dispersion of the exfoliated layered material, 4 parts by mass of dimethyldiethoxysilane, 1.2 parts by mass of diphenyldimethoxysilane, and 0.05 part by mass of 85% phosphoric acid were put in a glass container, and stirred at 10 ℃ for 3 hours, and then at 30 ℃ for hours, to produce a composite material of example 10. Further, the phenyl group content of the polysiloxane compound having an organic group of example 10 was 25 mass%.

[ preparation of resin composition ]

A composite material or a exfoliated layered material shown in Table 2 was mixed with 100 parts by mass of an addition-curable silicone resin (trade name: KE-109E-A/B, manufactured by shin-Etsu chemical industries) using a planetary stirring defoaming device in an amount of 10 parts by mass or 30 parts by mass. The mixture was heated at 100 ℃ and 5MPa for 1 hour to be cured by hot pressing, thereby producing a sheet-like resin composition having a thickness of 2mm, i.e., the resin sheets of examples 11 to 21 and comparative examples 2 to 5.

[ evaluation of dispersibility ]

The produced resin sheet was cut with a cryomicrotome, the center of the cross section was photographed with a microscope, and the number of aggregates per 300 μm × 300 μm and the ratio of aggregates were measured with image analysis software. Further, the amount of the aggregate was adjusted to 40 μm in area²The number of the above particles to be the aggregates is the ratio (%) of the total area of the aggregates to the total area of all the particles. The larger the amount of the aggregates, the larger the ratio of the aggregates, indicating a larger ratio of the aggregates. The results are shown in Table 2.

TABLE 2

The resin sheets of comparative examples 4 and 5 were examples using the composite material derived from the exfoliated layered substance a1, the resin sheets of examples 11 to 19 and comparative examples 2 to 3 were examples using the composite material derived from the exfoliated layered substance a1, the resin sheet of example 20 was an example using the composite material derived from the exfoliated layered substance a2, and the resin sheet of example 21 was an example using the composite material derived from the exfoliated layered substance A3. The resin sheets of examples 11 to 19 in which the exfoliated layered material a1 was coated with the polysiloxane compound having an organic group had improved dispersibility as compared with those of comparative examples 4 to 5 in which the resin sheet was not coated. The resin sheets of comparative examples 2 to 3 coated with polyvinyl alcohol had a lower dispersibility than the resin sheets of comparative examples 4 to 5 not coated, and it was found that the dispersibility was greatly different depending on the coating material.

[ evaluation of mechanical Properties ]

The resin sheet thus produced was processed into a dumbbell shape (No. 2), and the tensile strain was measured in accordance with JIS K6251 (method for determining tensile properties of vulcanized rubber and thermoplastic rubber). The results are shown in Table 3.

[ evaluation of Electrical characteristics ]

The surface resistance value was measured by a 4-probe method in accordance with JIS K7194 (resistivity test method of conductive plastics by the 4-probe method). The results are shown in Table 3.

TABLE 3

The resin sheets of examples 13 to 18, in which the surface of the graphite-based exfoliated layered material was coated with the polysiloxane compound having an organic group, had a larger strain change and had a lower surface resistivity than the resin sheets of comparative example 3 and comparative example 5, in which the resin sheets were coated with polyvinyl alcohol. This is presumably caused by the influence of dispersibility in the resin.

The resin sheet of example 21 in which the surface of the boron nitride based exfoliated layered substance was coated with the polysiloxane compound having an organic group was subjected to a larger change in tension than the resin sheet of comparative example 6 in which the surface was not coated. This is presumably caused by the influence of dispersibility in the resin. The surface resistivity was not different, and it is estimated that the conductivity of boron nitride was originally low.

Industrial applicability

According to the present invention, the dispersibility of the exfoliated layered material in a resin or the like is improved, and the physical properties of the obtained resin composition, such as toughness, elasticity, and impact resistance, are greatly improved.