JP6320838B2 - Metal oxide particles coated with a polymer having a (meth) acrylic group and a method for producing the same - Google Patents

Description

  The present invention relates to a novel polymer-coated metal oxide particle and a method for producing the same. Specifically, the present invention relates to a metal oxide particle in which at least a part of the surface of the metal oxide particle is coated with an epoxy polymer having a (meth) acryl group and a method for producing the metal oxide particle.

For sealing of electronic parts such as semiconductor packages and sealing parts of flat panel displays (FPD), a sealing material or sealing agent made of an epoxy resin composition (hereinafter collectively referred to as sealing material) is widely used. Has been.
In general, such a sealing material contains metal oxide particles such as silica as a filler for the purpose of controlling the thermal expansion coefficient, thermal conductivity, resin strength, moisture absorption, etc. of the sealing material. .

  Conventionally, surface treatment agents such as silane coupling agents have been used to modify the surface of metal oxide particles. By modifying the surface of the metal oxide particles, the dispersibility in the resin can be improved, and the viscosity of the resin composition can be reduced. Furthermore, the mechanical strength of the cured body can be improved.

  In general, thermosetting epoxy resins are used for electronic materials such as semiconductor packages. In order to improve the dispersibility in the epoxy resin and increase the mechanical strength of the cured body, it has been proposed to impart an epoxy group to the surface of the metal oxide particles (Patent Document 1). In this case, the epoxy group is applied to the particle surface by coating the surface of the metal oxide particle with a monomer having an epoxy group and a carbon-carbon double bond functional group, and then the carbon-carbon double layer. This is carried out by radical polymerization of the binding functional group.

  In recent years, there are an increasing number of fields in which photo-curing resins are used due to advantages such as high-speed curability at room temperature and energy and cost savings compared to thermosetting. In general, many photocurable resins are acrylic resins, and specifically, acrylic resin acrylate, epoxy acrylate, urethane acrylate, and the like are used. For this reason, there has been a need to provide metal oxide particles with an acrylic group or a methacrylic group that is more familiar with acrylic resins and can be polymerized together.

  In response to this requirement, a functional group is introduced into the surface of metal oxide particles by using a silane coupling agent having a (meth) acryl group. However, this method has a problem that the surface hydroxyl group present on the surface of the metal oxide particles acts as an acid, and the imparted (meth) acryl group is modified or deteriorated, so that the effect is not sufficiently maintained.

  In addition, it is conceivable to perform a hydrophobizing treatment in order to eliminate the effect of surface hydroxyl groups, but even in this case, it is difficult to perform the hydrophobizing treatment completely, and the temporal stability of the filler performance is reduced. (Patent Document 2).

  In the method according to Patent Document 1, the polymerization of the monomer for introducing an epoxy group onto the surface of the metal oxide particles is performed by radical polymerization of a carbon-carbon double bond functional group having the epoxy group. However, it is shown that not only an epoxy group but also an unpolymerized carbon-carbon double bond functional group remains by controlling the radical generation amount ([0030] [0036] [0041] [0041] 0042] etc.). And the (meth) acryl group is mentioned in the illustration of this carbon-carbon double bondable functional group.

JP 2009-192560 A JP-A-2005-171206

However, in the method according to Patent Document 1, since the carbon-carbon double bond functional group is introduced as a residue obtained by radical polymerization of the monomer to the end, it is inevitable that the amount introduced into the particles remains small. . Specifically, in the examples of the document, four examples of the polymer-coated metal oxide particles a-1 to a-4 are produced, but a double bond functional group (acrylic group) remains. There is only one example of a-3, and the result is that no functional group is introduced into the remaining three particles ([0102] to [0105]). And even if it is the particle | grains of such a-3, the abundance of the double bond functional group will be only 0.1 micromol / m < ² >, when converted into the molar amount per unit surface area of particle | grains.

  Thus, if the amount of the acrylic group present is small, even if blended with the acrylic resin, the familiar improvement effect is not sufficient, and further, the mechanical strength of the cured body is improved in addition to the polymerization. The effect could not be fully demonstrated.

  From the above, even when stored for a long period of time, the performance is stable without deterioration, the viscosity when blended with an acrylic resin is low, and when cured, the cured body is firmly bonded to the matrix resin. Developing a metal oxide particle to which a (meth) acryl group is imparted that can improve the mechanical strength has been a major issue.

  The present inventors have intensively studied to solve the above problems. As a result, with respect to the polymerization of the monomer having an epoxy group and a (meth) acryl group, the (meth) acryl group is obtained by polymerizing the epoxy group by cationic polymerization and coating the metal oxide particles with the polymer. Has been obtained. And if it is a metal oxide particle which provided a large amount of (meth) acryl groups in this way, it is excellent in the dispersibility to acrylic resin, and the mechanical strength of the hardened | cured material, and also in this way metal oxide In the embodiment of the polymer covering the product particles, when the (meth) acrylic group is introduced into the particles, it is found that the (meth) acrylic group is hardly modified or deteriorated and excellent in storage stability. It came to complete.

That is, in the present invention, at least a part of the surface of the metal oxide particles is coated with an epoxy polymer having a (meth) acryl group, and the amount of the (meth) acryl group is 0.5 to 0.5 per unit surface area of the particle. 30 μmol / ^{m 2} der is, volume-reduced cumulative 50% diameter measured by a laser diffraction scattering method (D50 diameter), characterized in 0.1~10μm der Rukoto, coated with a polymer having a (meth) acrylic group Metal oxide particles.

Further, the present invention is such (meth) As a method for producing metal oxide particles coated with a polymer having an acrylic group, an epoxy group in a molecule and (meth) monomers having One not a one, respectively an acrylic group And an epoxy polymerizable composition comprising an epoxy curing agent and metal oxide particles are mixed to obtain metal oxide particles whose surfaces are coated with the epoxy polymerizable composition , and then the epoxy groups are cationically polymerized. Ru is, a (meth) the method for producing metal oxide particles coated with a polymer having an acryl group,
The coating amount of the metal oxide particles by the epoxy polymerizable composition is introduced by a polymer obtained by cationic polymerization of the epoxy group with a (meth) acryl group of 0.5 to 30 μmol / m ² per unit surface area of the particle. For producing metal oxide particles having a volume-based cumulative 50% diameter (D50 diameter) of 0.1 to 10 [mu] m by a laser diffraction scattering method and coated with a polymer having a (meth) acrylic group Also provide.

  Since the metal oxide particles of the present invention have a large amount of (meth) acrylic groups introduced on the surface, when blended with a polar resin such as an acrylic resin or an epoxy resin, the metal oxide particles are highly filled. However, the increase in viscosity can be kept low, and the viscosity can be easily controlled. Moreover, in the cured product when blended with the acrylic resin, the (meth) acrylic group is firmly bonded to the cured product of the acrylic resin, so that the mechanical strength is improved.

  In addition, since the (meth) acrylic group is provided by the polymer covering the metal oxide particles, the modification by the influence of the hydroxyl group on the surface of the metal oxide particles Deterioration hardly occurs and storage stability is excellent.

FIG. 1 is a diagram for explaining a method for measuring the adhesive strength after resin curing in a resin composition obtained by adding metal oxide particles to an acrylic resin, implemented in each example of the present application.

  In the present invention, at least a part of the surface of the metal oxide particles is coated with an epoxy polymer having a (meth) acryl group (hereinafter also referred to as “(meth) acryl group-containing polymer-coated particles”). . Here, the type of metal oxide is not particularly limited, and specifically, metal oxides such as silica, alumina, titania, zirconia, and metal composite oxides such as silica titania, silica zirconia, etc., among others, Silica and silica-based particles such as silica-based composite oxide having a silica content of 50% by mass or more are preferable, and silica titania is particularly preferable as the silica-based composite oxide.

In the present invention, the (meth) acrylic group-containing polymer-coated particles have a volume-based cumulative 50% diameter (D50 diameter) (hereinafter also referred to as an average particle diameter) of 0.1 to 10 μm by a laser diffraction scattering method. range der is, more preferably 0.1 to 5 [mu] m, particularly preferably 0.1 to 1.5 [mu] m. When the average particle size is less than 0.05 μm, the viscosity tends to increase when dispersed in a resin. Moreover, when it exceeds 10 micrometers, when it uses as a semiconductor sealing agent, narrow gap sealing and uniform sealing will become difficult.

  The shape of the (meth) acrylic group-containing polymer-coated particles is not particularly limited, and examples thereof include a spherical shape, a plate shape, a layer shape, a needle shape, and an amorphous shape. The spherical shape is particularly preferred from the standpoint that the viscosity of the product is reduced, and further that when this resin composition is used for semiconductor encapsulation, it is difficult to damage the semiconductor element.

  At least a part of the surface of the metal oxide particles is coated with an epoxy polymer having a (meth) acryl group. For this reason, the particles are excellent in dispersibility in polar resins such as acrylic resins and epoxy resins, and when filled into these resins, low viscosity is achieved, especially when filled in acrylic resins. Can satisfactorily improve the mechanical strength of the cured product.

  Furthermore, the (meth) acrylic group-containing polymer-coated particles of the present invention are excellent in resistance to modification and deterioration of (meth) acrylic groups as described above. This is considered to be due to the fact that the (meth) acrylic group is introduced in the form of the polymer covering the metal oxide particles. That is, when introduced as a functional group possessed by the polymer as described above, as compared with the case of introduction using a silane coupling agent having a (meth) acryl group, It is estimated that the polymer is surrounded by the polymer, and even if a hydroxyl group (-OH group) is present on the particle surface of the part, it is not exposed and is less susceptible to acid action and moisture absorption. Is done.

The greatest feature of the present invention is that the (meth) acryl group introduced into the metal oxide particles is contained in the coating polymer in this manner, and 0.5 to 30 μmol / m ² per unit area of the particles. and it lies in a large amount. Thus, since there are many introduction amounts of (meth) acryl group, the improvement effect of the dispersibility to acrylic resin and the improvement of the hardening body of the obtained resin composition is exhibited highly. As described above, it was difficult to produce polymer-coated particles by applying a large amount of (meth) acrylic groups, and a large number of (meth) acrylic groups were introduced as described above. The polymer coated particles are provided for the first time by the present invention. A manufacturing method that enables this provision will be described in detail later.

Here, when the abundance of the (meth) acryl group present on the surface of the particle is smaller than 0.5 μmol / m ² per unit area, the effect of the acrylic group on the particle surface described above becomes small. Moreover, when it is going to manufacture the polymer covering particle | grains larger than 60 micromol / m < ² >, it becomes easy to produce | generate an aggregated particle at the time of manufacture. Taking these into consideration, the more preferable abundance of the (meth) acryl group present on the surface of the particle is ² to 30 μmol / m ² .

In the present invention, the abundance (μmol / m ² ) of (meth) acrylic groups per unit area of the (meth) acrylic group-containing polymer-coated particles refers to a value calculated as follows. First, the amount of C═C bonds in the functional group is measured by the Wiis method to determine the amount of (meth) acrylic group (mol / g) per unit mass of the (meth) acrylic group-containing polymer-coated particle, This value is calculated by dividing the value by the specific surface area of the (meth) acrylic group-containing polymer-coated particles. The specific surface area of the particles is a value measured by the BET single point method.

  In the (meth) acrylic group-containing polymer-coated particles of the present invention, the proportion of the particle surface covered with the (meth) acrylic group-containing epoxy polymer is such that the amount of (meth) acrylic groups is in the above range. As long as it is not particularly limited, an embodiment in which the surface of the particle is preferably 50% or more, more preferably 70% or more, and most preferably the entire surface is coated with a polymer.

  Originally, a hydroxyl group (—OH group) is present on the surface of the metal oxide particles and thus exhibits hydrophilicity. It is preferable that the area covered with the polymer is larger because the influence of hydroxyl groups (—OH groups) on the particle surface can be reduced, so that moisture absorption can be suppressed and stability over time is excellent.

  The state of the coating is not particularly limited as long as the epoxy polymer is fixed to the surface of the metal oxide particles so as not to be easily detached. For example, when the metal oxide particles have pores. May be in a state in which the wall surface of the pore is covered, in a state in which the pore is buried, or in a state in which they are combined.

  When the entire surface of the (meth) acrylic group-containing polymer-coated particle of the present invention is not coated with a (meth) acrylic group, a hydroxyl group (-OH group) remains and is exposed in this uncoated portion, The hydrophobicity is lowered. The hydroxyl group (—OH group) is hydrophilic and hygroscopic. Therefore, the (meth) acrylic group-containing polymer-coated particles of the present invention are preferably a hydrophobized product that has been separately hydrophobized to eliminate the remaining hydroxyl groups (—OH groups).

  In such a hydrophobized product, the hydrophobicity is preferably 5 to 60, and more preferably 30 to 55. When the hydrophobicity is smaller than the above range, the temporal stability is lowered, such as moisture absorption during storage, and the viscosity tends to increase in the resin composition when filled in the resin due to the influence of the remaining surface hydroxyl groups. When the hydrophobicity is higher than the above range, for example, the dispersibility in a polar resin such as an acrylic resin or an epoxy resin is lowered, and the viscosity characteristic tends to become unstable.

  In the present invention, the hydrophobicity is a value determined by the following procedure. That is, 1 g of (meth) acrylic group-containing polymer-coated particles was added to 50 mL of water, methanol was added dropwise with a burette while stirring with a magnetic stirrer, and the entire amount of (meth) acrylic group-containing polymer-coated particles was suspended. The time point was the end point, and the methanol volume percentage in the mixed liquid in the beaker at the end point was calculated as the hydrophobicity. A higher value of hydrophobicity indicates higher hydrophobicity.

  The (meth) acrylic group-containing polymer-coated particles having the above properties are not limited as long as they satisfy the requirements, and can be generally produced by the following method.

That is, epoxy group and in one molecule (meth) monomers having One not a one, respectively an acrylic group, and an epoxy polymerizable composition comprising an epoxy curing agent and the metal oxide particles are mixed, the resulting In this method, the epoxy group of the metal oxide particle whose surface is coated with an epoxy polymerizable composition is cationically polymerized. In this method, the coating amount of the metal oxide particles by the epoxy polymerizable composition is 0.5 to 30 μmol / m ² per unit surface area of the particles depending on the polymer obtained by cationic polymerization of the epoxy group. The (meth) acrylic group-containing polymer-coated particles of the present invention can be efficiently produced by carrying out the process so that the amount of the (meth) acrylic group is introduced.

  In this method, the polymerization of the monomer having one epoxy group and one (meth) acryl group in one molecule is carried out by cation polymerization of epoxy groups, not by conventional radical polymerization of (meth) acryl groups. Therefore, substantially all of the (meth) acrylic group remains in the obtained polymer. As a result, the metal oxide particles covering the surface of the polymer have a large amount of the (meth) acrylic group. It can have. This preferred production method will be described in detail below.

  The epoxy polymerizable composition that coats the surface of the metal oxide particles includes a monomer having one epoxy group and one (meth) acryl group in one molecule, and an epoxy curing agent. Of these, the former monomer (hereinafter also referred to as “epoxy group / (meth) acryl group-containing monomer”) is particularly limited as long as it has one epoxy group and one (meth) acryl group in one molecule. It can use suitably. For example, glycidyl acrylate, glycidyl methacrylate, β-methyl glycidyl acrylate, β-methyl glycidyl methacrylate, bisphenol A-monoglycidyl ether-methacrylate, 4-glycidyloxybutyl methacrylate, 3- (glycidyl-2-oxyethoxy)- Examples include 2-hydroxypropyl methacrylate, 3- (glycidyloxy-1-isopropyloxy) -2-hydroxypropyl acrylate, 3- (glycidyloxy-2-hydroxypropyloxy) -2-hydroxypropyl acrylate, and the like. Of these, glycidyl (meth) acrylate is preferred.

The amount of the epoxy group / (meth) acryl group-containing monomer may be appropriately determined according to the type of the monomer, the reaction rate of cationic polymerization, the amount of metal oxide particles serving as a substrate, and the specific surface area. What is necessary is just to adjust so that the abundance of a (meth) acryl group may be 0.5-30 micromol / m < ² > per unit surface area of a metal oxide particle. If the amount of the monomer is too small, the amount of functional groups on the particle surface of the (meth) acrylic group-containing polymer-coated particles obtained is reduced, and the effects of the present invention cannot be fully exhibited. If the amount of the monomer is too large, the excess monomers react with each other to produce aggregated particles.

  The epoxy curing agent is not particularly limited, and known ones can be suitably used. For example, organic acid dihydrazide compounds, imidazole and its derivatives, aromatic amines, dicyandiamide and the like can be mentioned. Of these, one type may be used alone, or two or more types may be used in combination.

  The amount of the epoxy curing agent may be determined according to the amine equivalent of the epoxy curing agent to be used. Generally, it is preferably 20 to 200 parts by mass, more preferably 40 to 100 parts by mass with respect to 100 parts by mass of the epoxy group / (meth) acryl group-containing monomer.

  In this invention, an epoxy resin, a hardening accelerator, etc. can be added to the said epoxy polymerizable composition as needed.

  The epoxy resin is an organic compound having at least one epoxy group (oxirane ring), and the number of epoxy groups (oxirane ring) per molecule of the epoxy resin is one or more, preferably two or more. Any known one can be used without particular limitation. For example, bisphenol type epoxy resins such as bisphenol A and bisphenol F, cresol novolac type epoxy resins, phenol novolac type epoxy resins and the like can be mentioned. These compounds include monomers and oligomers. In the present invention, these may be used alone or in combination of two or more.

  When adding an epoxy resin, the amount of the epoxy resin may be determined according to the epoxy equivalent of the epoxy resin to be used. Generally, it is preferable that it is 10-500 mass parts with respect to 100 mass parts of epoxy group and (meth) acryl group containing monomers, and it is more preferable that it is 50-300 mass parts. By adding an epoxy resin, the number of epoxy groups in the epoxy polymerizable composition increases, resulting in an increase in the polymerization reaction part, resulting in an increase in polymerization reactivity and reaction rate, and a stronger epoxy polymer can be produced. .

  As the above, known ones can be used without particular limitation. For example, imidazole curing accelerators such as imidazole and 2-methylimidazole, phosphine derivatives such as triphenylphosphine, tris-p-methoxyphenylphosphine, and tricyclohexylphosphine, 1,8-diazabicyclo (5.4.0). And cycloamidine derivatives such as undec-7-ene.

  When the curing accelerator is added, the amount of the curing accelerator is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the epoxy group / (meth) acrylic group-containing monomer. is there. By adding a curing accelerator, reaction time can be shortened and production efficiency can be improved.

  In the epoxy polymerizable composition thus prepared, the epoxy group / (meth) acryl group-containing monomer is preferably 15 to 80% by mass in the total composition, and is 15% to 60% by mass. More preferably, it is more preferably 20 to 50% by mass.

  Further, the epoxy polymerizable composition may be diluted with a solvent and mixed with metal oxide particles. In particular, when the viscosity of the epoxy polymerizable composition is high, it can be more uniformly processed by diluting, and aggregates can be reduced.

  The solvent used for dilution is not particularly limited as long as the epoxy polymerizable composition can be dissolved. Examples thereof include alcohols such as methyl alcohol, ethyl alcohol, and 1-propyl alcohol.

  Although the dilution rate at the time of diluting with a solvent is not specifically limited, Generally it is about 2 to 5 times.

  In the production method, the coating amount of the epoxy polymerizable composition on the metal oxide particles is the treatment amount of the metal oxide particles, the specific surface area, the amount of (meth) acrylic groups in the epoxy polymerizable composition, and the cationic polymerization. In view of the reaction rate, etc., it is not particularly limited as long as it is appropriately determined. It is. When there is too much quantity of an epoxy polymerizable composition, it will become easy to produce | generate an aggregated particle. On the other hand, if the amount is too small, it is difficult to coat uniformly.

  In the present invention, the mixing of the metal oxide particles and the epoxy polymerizable composition may be performed as long as the epoxy polymerizable composition is uniformly coated on the particle surface of the metal oxide particles by absorption or adsorption. It is not limited. For example, a method of directly mechanically mixing using a Henschel mixer or the like, a method of mixing by blowing a high-speed air current, a method of mixing by applying vibration or rocking from the outside, and the like can be mentioned. The specific apparatus used is not particularly limited as long as it can maintain a state in which the metal oxide particles are partially suspended in the processing container during mixing. Examples thereof include a Henschel mixer, a V blender, a rocking mixer, a fluidized bed, and a double cone type mixing device.

The material of the apparatus is not particularly limited, and glass, metal such as stainless steel (including glass coated or resin coated), or resin can be used. The size of the apparatus is not particularly limited, but generally, an apparatus having an internal volume of 10 L to 1 m ³ is preferably used.

  A crushing blade can be further installed in the mixing apparatus used in the present invention. The crushing blade is a blade for crushing the agglomerated particles, and is different from a rotating body having a drive unit as a mixing means, that is, a stirring / mixing blade, which has a different energy level and is clearly distinguished. The By using the crushing blade, the aggregated particles are remarkably reduced, and the particle size distribution of the metal oxide particles is equivalent before and after the surface treatment. When installing this crushing blade | wing, it is preferable that the crushing energy of this crushing blade | wing is 10-200J. If it is less than 10 J, the aggregated particles cannot be sufficiently crushed and the aggregated particles remain. On the other hand, if it exceeds 200 J, there arises a problem that the metal oxide particles easily reaggregate. Generally, the stirring energy of the stirring / mixing blade used as the mixing means is 600 J or more, which is much larger than the crushing energy.

  In the present invention, the processing amount of the metal oxide particles to be processed at one time is not particularly limited, but considering general processing efficiency, it is preferably 10 to 60%, more preferably the internal volume of the mixing device. A mode in which about 30 to 50% is charged is preferably employed. When the treatment amount is too small relative to the internal volume of the apparatus, the treatment efficiency is poor, and when it is too large, the metal oxide particles cannot obtain a suitable void during mixing, and aggregated particles are easily generated.

  What is necessary is just to determine suitably the time concerning mixing according to the processing amount of the metal oxide particle to process, and the capability of the mixing apparatus to be used. For example, when 30 kg of metal oxide particles are processed using a V blender having an internal volume of 136 L, the metal oxide particles are sufficiently mixed within 3 hours.

  In addition, the method for supplying the epoxy polymerizable composition is not particularly limited when mixing the metal oxide particles and the epoxy polymerizable composition. You may supply at once, and you may supply continuously or intermittently. At that time, the metal oxide particles may be supplied while being mixed, or may be supplied in a stationary state. When the amount of treatment is large or when the amount of the epoxy polymerizable composition is large, the surface treatment can be performed more uniformly by mixing continuously or intermittently while mixing, and the formation of aggregates can be reduced. preferable.

  When the epoxy polymerizable composition is continuously or intermittently supplied, the supply rate of the epoxy polymerizable composition is not particularly limited, but may be appropriately determined in consideration of the processing amount and the supply amount of the epoxy polymerizable composition. It ’s fine. In particular, when the supply amount of the epoxy polymerizable composition is large, the processing time becomes long if the supply speed is slow, so that the productivity is inferior. If the epoxy polymerizable composition is supplied at once or the supply speed is too high, the epoxy polymerizable composition is insufficient. The droplets of the composition become large, and aggregated particles are easily generated in the metal oxide particles.

  The means for supplying the epoxy polymerizable composition is not particularly limited. However, when the supply amount is large, when supplying continuously or intermittently, by dropping or spraying using a pump capable of adjusting the supply rate. It is preferable to supply. A known spray nozzle or the like can be suitably used for the spraying. In general, the supply rate is preferably 1 to 20 mL / min per 100 g of the metal oxide particles to be processed.

  Although the temperature at the time of supplying the said epoxy polymerizable composition and mixing with a metal oxide particle is not specifically limited, It is preferable to set lower than the temperature which the epoxy polymerization reaction mentioned later advances. Generally, it is about -10-40 degreeC. When the temperature is too high, the epoxy polymerizable composition is polymerized before being uniformly absorbed or adsorbed on the surface of the metal oxide particles, and aggregated particles are generated.

  Moreover, the atmosphere in the mixing apparatus is not particularly limited, but an inert gas such as nitrogen, helium or argon is preferably used. Further, the pressure in the mixing apparatus is not particularly limited, and may be pressurized, normal pressure, or reduced pressure.

  Next, the epoxy group in the epoxy polymerizable composition of the metal oxide particles coated with the obtained epoxy polymerizable composition is cationically polymerized. The method for cationically polymerizing the epoxy group is not particularly limited, but a method of allowing polymerization to proceed by heating is common. At this time, in order to suppress the formation of aggregated particles, it is preferable to proceed with polymerization by heating with stirring.

  The heating temperature may be appropriately set so that cationic polymerization proceeds in consideration of the type and amount of the epoxy group / (meth) acrylic group-containing monomer and the curing agent or curing accelerator used. If the treatment temperature is too low, the progress of the reaction slows down, so that the production efficiency is lowered. Generally, it is good to carry out at 40 to 200 degreeC, Preferably it is 80 to 150 degreeC.

  What is necessary is just to determine suitably the time concerning the said heat processing according to the reactivity in the said processing temperature of the epoxy polymerizable composition to be used. Usually, a sufficient reaction rate can be obtained within 24 hours.

  The cationic polymerization is preferably performed in an inert gas atmosphere such as nitrogen, helium, or argon in order to prevent polymerization inhibition by oxygen and to suppress thermal decomposition of the epoxy polymerizable composition. Further, the pressure in the reaction vessel is not particularly limited, and may be increased, normal, or reduced.

  As described above, a metal coated with a polymer having a (meth) acryl group on the particle surface of the present invention by cationic polymerization of the epoxy group of the epoxy group / (meth) acryl group-containing monomer on the surface of the metal oxide particle. It is possible to efficiently produce oxide particles.

  The (meth) acrylic group-containing polymer-coated particles of the present invention can be separately hydrophobized. As described above, the hydrophobizing treatment is preferably performed so that the hydrophobicity of the (meth) acrylic group-containing polymer-coated particles is 5 to 60.

  As the hydrophobizing method, the metal oxide particles as a base material may be hydrophobized in advance before mixing with the epoxy polymerizable composition, or the epoxy group is cationically polymerized on the surface of the metal oxide particles. Thereafter, the surface of the obtained fine particles may be treated, or after the epoxy group is cationically polymerized on the surface of the metal oxide particles that have been previously hydrophobized, the resulting (meth) acryl group-containing polymer-coated particles are obtained. May be further hydrophobized.

  The hydrophobic treatment method is not particularly limited, and a known method for introducing a hydrophobic group or a hydrophobic substance onto the surface can be used. As the hydrophobizing agent for hydrophobizing, known silane coupling agents, siloxanes, silazanes, silicone oils and the like are used without particular limitation.

  Examples of the silane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, and decyltrimethoxysilane. Disiloxane, hexamethyldisiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, etc. for siloxanes, polydimethylsiloxane etc. for polysiloxanes, and hexasiloxanes for silazanes Methyl disilazane can be used. Among them, a method of treating with hexamethyldisilazane or siloxane is more preferably employed because the treatment effect is high and the hydrophobic treatment agent is unlikely to be eluted or oozed out. Since these treatment agents have high reactivity, even when the amount of reactive groups such as hydroxyl groups (—OH groups) present on the surface of the metal oxide particles is small, a high hydrophobizing treatment can be performed.

  In the present invention, the mixing apparatus for mixing the metal oxide particles and the hydrophobizing agent is not particularly limited, but the mixing apparatus, size, and material used for mixing the metal oxide particles and the epoxy polymerizable composition are not limited. , Functions and the like can be preferably used. It is preferable that crushing blades are installed because generation of aggregated particles can be suppressed.

  First, the metal oxide particles are supplied to the mixing device. The supply amount of the metal oxide particles is not particularly limited as long as the supplied metal oxide particles can be mixed, but as described above, it is preferably 1 to 60%, more preferably, relative to the internal volume of the mixing device. Is 30-50%.

Next, the hydrophobizing agent is supplied to the mixing apparatus supplied with the metal oxide particles. The supply amount of the hydrophobizing agent is an amount necessary for coating the particle surface of the metal oxide particles to be treated, that is, from the amount of surface hydroxyl groups of the metal oxide particles to be treated and the hydrophobizing agent to be used. The theoretical addition amount may be calculated and appropriately determined according to the theoretical addition amount, but is generally 0.1 to 10 parts by mass with respect to 100 parts by mass of the metal oxide particles to be processed. Generally, the surface hydroxyl group amount of the metal oxide particles is about 0.5 to 15 / nm ^{2 in} the case of amorphous silica, for example.

  If the supply amount of the hydrophobizing agent is too small relative to the theoretical addition amount, it is not preferable because the surface of the metal oxide particles cannot be sufficiently treated. If the amount exceeds 5 times the theoretical addition amount, This is not preferable because the problem that the hydrophobizing agents react with each other to generate aggregated particles occurs. If the hydrophobizing agent is 5 times or less, preferably 3 times or less of the theoretical addition amount, it is possible to uniformly treat the metal oxide particle surface without forming aggregated particles.

  The theoretical addition amount of the hydrophobizing agent to be supplied is just the particle surface of the metal oxide particles based on the number of hydroxyl groups on the surface of the metal oxide particles to be treated and the number of reaction sites of the hydrophobizing agent. This is the amount covering all the hydroxyl groups. Here, the number of hydroxyl groups on the surface of the metal oxide particles is determined from the absorption spectrum intensity of the wavelength corresponding to the hydroxyl group using a Fourier transform infrared spectrophotometer.

  The hydrophobizing agent can be mixed with metal oxide particles after being diluted with a solvent. The solvent to be used is not particularly limited as long as it can dissolve the hydrophobizing agent. For example, alcohols such as methyl alcohol, ethyl alcohol, and 1-propyl alcohol are preferably used, but organic solvents other than alcohols can also be used. Although the dilution rate at the time of diluting with a solvent is not specifically limited, Generally it is used by diluting about 2 to 5 times.

  The method for supplying the hydrophobizing agent may be supplied all at once, or may be supplied continuously or intermittently while mixing. However, when the treatment amount is large or the amount of the hydrophobizing agent is In many cases, it is preferable to supply continuously or intermittently while mixing. It is preferable to supply the hydrophobizing agent by dropping or spraying using a pump or the like. A known spray nozzle or the like can be suitably used for the spraying. Moreover, the atmosphere in the mixing apparatus is not particularly limited, but an inert gas such as nitrogen, helium or argon is preferably used. By doing so, decomposition | disassembly of the hydrophobization processing agent by a heat | fever can be suppressed.

  When the hydrophobizing agent is supplied continuously or intermittently, the supply rate of the hydrophobizing agent is not particularly limited, but may be determined in consideration of the supply amount of the hydrophobizing agent, etc. Is preferably supplied at 1 to 20 mL / min per 100 g of metal oxide particles. In particular, when the supply amount of the hydrophobizing agent is large, the processing time becomes long if the supply speed is slow, so that the productivity is inferior. When the hydrophobizing agent is supplied all at once or the supply rate is too high, the hydrophobizing agent The droplets become large, and aggregated particles are easily generated in the metal oxide particles.

  Although the temperature condition at the time of supplying the said hydrophobic treatment agent and mixing with a metal oxide particle is not specifically limited, Since a hydrophobic treatment agent will superpose | polymerize when temperature is too high, generally -10-40 degreeC. Degree.

  In the above mixing, it is sufficient that the hydrophobizing agent is uniformly mixed with the metal oxide particles, and the time required for mixing is appropriately determined according to the processing amount of the metal oxide particles to be processed and the ability of the mixing apparatus to be used. do it. For example, when treating 80 kg of metal oxide particles using a double cone type mixer having an internal volume of 340 L, the metal oxide particles are sufficiently mixed within 3 hours.

  Next, the surface of the metal oxide particles is coated with the hydrophobizing agent by heat-treating the mixture of the metal oxide particles with reduced aggregated particles and the hydrophobizing agent. In the case of using a mixing device having a heating means, the heat treatment can be performed by adding heat while mixing, but the metal oxide particles sufficiently mixed with the hydrophobizing agent are taken out and heated separately. It is also possible to heat with an apparatus and heat treatment without mixing means.

  In the latter, the atmosphere gas in another heating device is not particularly limited, but it is preferable to use an inert gas atmosphere such as nitrogen, helium, argon, etc., as in the above mixing device.

  If the temperature at which the heat treatment is performed is too low, the progress of the reaction is slowed, so that the production efficiency is lowered. If the temperature is too high, decomposition of the hydrophobizing agent is promoted. Therefore, although it depends on the hydrophobizing agent used, it is generally 40 to 200 ° C., preferably 80 to 150 ° C.

  What is necessary is just to determine the said heat processing time suitably according to the reactivity of the hydrophobization processing agent to be used. Usually, a sufficient reaction rate can be obtained within 24 hours.

  The (meth) acrylic group-containing polymer-coated particles have greatly improved dispersibility in the resin, can be highly filled with metal oxide particles, and can be expected to improve the strength of the cured resin. It is also suitably used for a semiconductor sealing material.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

  Hereinafter, evaluation methods of physical properties used for evaluation in Examples and Comparative Examples are as follows.

(Average particle size)
The average particle diameter (μm) of the metal oxide particles before and after the surface treatment was measured with a laser diffraction scattering particle size distribution analyzer (LS-230, manufactured by Beckman Coulter, Inc.). The average particle diameter (μm) here means a volume-based cumulative 50% diameter (μm).

(Specific surface area)
The specific surface area (m ² / g) of the metal oxide particles before and after the surface treatment was measured by a BET single point method (SA-1000, manufactured by Shibata Kagaku Kogyo Co., Ltd.).
(Hydrophobicity)
50 mL of water was put into a 300 mL capacity beaker, and 1 g of metal oxide particles was added. While stirring with a magnetic stirrer, methanol was added dropwise with a burette, and the end point was when the entire amount of metal oxide particles was suspended. The percentage by volume of methanol in the liquid mixture of the beaker at the end point was taken as the hydrophobicity.

((Meth) acrylic group content)
First, the amount of (meth) acrylic groups is determined by measuring the amount of C═C bonds in the functional groups by the Wiis method, and the amount of (meth) acrylic groups per unit mass of the (meth) acrylic group-containing polymer-coated particles (mol) / G), and then this value was calculated by dividing by the specific surface area of the (meth) acrylic group-containing polymer-coated particles. Specifically, the following procedure is followed.
Weigh 1 g of (meth) acrylic group-containing polymer-coated particles into a 25 mL sample tube, add 3 mL of chloroform and 200 μL to 700 μL of Wies' reagent (0.1 mol / L ICl acetic acid solution), and shield from light for 3 hours with a mix rotor. Stir. Next, 50 μL of 100 g / L potassium iodide aqueous solution and 4 mL of water were added, and the mixture was well shaken by hand. Finally, this was titrated with 0.01 mol / L sodium thiosulfate aqueous solution, and the amount of (meth) acrylic groups in 1 g of (meth) acrylic group-containing polymer-coated particles was determined.
Also, originally, in order to obtain iodine contained in the Wies reagent, a blank test was similarly performed without adding metal oxide particles.
The amount of (meth) acrylic groups per unit mass of the (meth) acrylic group-containing polymer-coated particles was determined using the following formula.
A = (B−C) × D × 10 ⁻³ / 2
A: The amount of (meth) acrylic groups per 1 g of (meth) acrylic group-containing polymer-coated particles (mol / g)
B: Amount of sodium thiosulfate solution used in the blank test (mL)
C: Amount of sodium thiosulfate solution used for titration (mL)
D: Concentration of sodium thiosulfate (0.01 mol / L)
Next, the amount of (meth) acrylic groups per unit area of the (meth) acrylic group-containing polymer-coated particles was determined using the following formula.

N = A / S × 10 ⁶
N: (Meth) acrylic group content (μmol / m ² ) per 1 m ^{2 of} (meth) acrylic group-containing polymer-coated particles
S: Specific surface area of the (meth) acrylic group-containing polymer-coated particles (m ² / g)
(Storage stability)
10 g of the (meth) acrylic group-containing polymer-coated particles were put in a screw tube bottle having a capacity of 50 mL, and stored in a constant temperature and humidity machine (temperature 35 ° C., humidity 80% condition) for 24 hours. A sample is taken out after 24 hours, and the amount of (meth) acrylic groups is obtained by the above (meth) acrylic group content measurement method. The difference between the surface treatment and the storage at a constant temperature and humidity is calculated by the following formula, and the storage stability is calculated. evaluated.

Storage stability (%) = 100-((meth) acrylic group amount after surface treatment- (meth) acrylic group amount after storage at constant temperature and humidity) / (meth) acrylic group amount after surface treatment × 100
And it was judged that storage stability was favorable if the numerical value of storage stability was 90% or more.

(viscosity)
Viscosity evaluation when the metal oxide particles were filled in a polar resin was evaluated by filling the epoxy resin. 25 g of metal oxide particles were added to 25 g of bisphenol A + F type mixed epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., ZX-1059) and kneaded by hand. In addition, 0.25 g of methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone, KBM-503, hereinafter referred to as MPTMS) is further added to the untreated metal oxide particles not subjected to any surface treatment including only hydrophobization treatment. , Hand kneaded. Each of the resin compositions kneaded by hand was pre-kneaded with a rotating and rotating mixer (manufactured by THINKY, Awatori Kentaro AR-500) (kneading: 1000 rpm, 8 minutes, defoaming: 2000 rpm, 2 minutes). The pre-kneaded resin composition was kneaded using three rolls (manufactured by IMEX, BR-150HCV roll diameter φ63.5). The kneading conditions were such that the kneading temperature was room temperature, the distance between rolls was 20 μm, and the number of kneading was 5 times.

The viscosity of the kneaded resin composition at a shear rate of 1 s ⁻¹ was measured with a rheometer (manufactured by HAAKE, Reo Stress).

(Adhesive strength)
1 g of O-cresol novolak epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-1020-75) and 1 g of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., Viscoat # 300) are placed in an alumina mortar and heated at 120 ° C. A uniform epoxy acrylate solution was obtained. To the above solution, 0.5 g of metal oxide particles were added and thoroughly rubbed in a mortar to be uniformly dispersed. Moreover, about the metal oxide particle of the unprocessed goods which did not perform any surface treatment including only the hydrophobization process, 0.005g of MPTMS was further added, and it rubbed well in the mortar and was disperse | distributed uniformly. After uniform dispersion, 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (Ajinomoto Finetechno, Amicure VDH), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl), respectively -Butanone-1 (manufactured by Ciba Japan, Irgacure 369) and N, N'-tetraethyldiaminobenzophenone were added all at once and mixed well. Finally, 2-phenyl-4-methylimidazole (manufactured by Shikoku Chemicals, Curazole 2P4MZ) was added and further mixed.

  The resin composition obtained by mixing was put into a UV syringe, and kneaded and defoamed with a rotating and rotating mixer (manufactured by THINKY, Awatori Netaro ARE-250) (kneading: 2000 rpm, 2 minutes, defoamed) : 2200 rpm, 5 minutes).

Next, a certain amount of the resin composition is applied on the glass using a dispenser (manufactured by Musashi Engineering Co., Ltd., ML-5000XII), and a pair of similar glasses is laminated on the cross to apply a load. Then, photocuring was performed by applying an ultraviolet irradiation device (365 nm, 5 minutes).
After curing, a wire was attached to the cross glass sample, pulled from above and below, and the adhesive strength was measured using a tensile / compression tester (manufactured by Shimadzu Corporation, EZ-test) (see FIG. 1).

Example 1
30 kg of Sunseal SS-04 (silica particles having an average particle diameter of 0.4 μm and a specific surface area of 7 m ² / g) is charged in a V blender (made by Tokuju Kosakusho, model V-60) having an internal volume of 136 L, and the atmosphere is kept under a nitrogen atmosphere. Replaced. Next, hexamethyldisilazane (manufactured by Shin-Etsu Silicone, SZ-31, hereinafter, HMDS) was added dropwise with 200 g (6 μmol / m ^{2 with} respect to silica) peristaltic pump, and heated at 110 ° C. for 3 hours. After the above treatment, 700 g of bisphenol F type epoxy resin (manufactured by Japan Epoxy Resin, JER806) (10 μmol / m ^{2 with} respect to silica) and 300 g of glycidyl methacrylate (Kyoeisha Chemical Co., Ltd., light ester G, hereinafter, GMA) 10 μmol / m ² ) and 4,4′-methylenebis (2-methylcyclohexaneamine) (manufactured by Japan Epoxy Resin, JER113) 250 g (5 μmol / m ^{2 with} respect to silica) mixed epoxy polymerizable composition Then, the mixture was heated at 110 ° C. for 3 hours.

The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 53, a methacryl group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 36 Pa · s. The adhesive strength after curing was 52N.

Example 2
In Example 1, hexamethyldisilazane was changed to 370 g (6.0 μmol / m ^{2 based on} silica) of octamethylcyclotetrasiloxane (manufactured by Toray Dow Corning, SH224 FLUID, hereinafter, D4). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.

The obtained surface-treated silica has an average particle diameter of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 52, a methacryl group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80%, and stored for 24 hours. The amount of methacrylic groups later was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 31 Pa · s. The adhesive strength after curing was 52N.

Example 3
In Example 1, GMA was changed to 270 g of glycidyl acrylate (hereinafter referred to as GA) (10 μmol / m ^{2 based on} silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.

The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 53, an acrylic group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of the later acrylic group was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 30 Pa · s. The adhesive strength after curing was 55N.

Example 4
In Example 1, JER806 was changed to 780 g of bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin, JER828) (10 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 54, a methacryl group content of 9 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 9 μmol / m ² and the storage stability was 100%.
The viscosity of the resin composition was 35 Pa · s. The adhesive strength after curing was 53N.

Reference example 1
In Example 1, JER806 was changed to 1400 g (20 μmol / m 2 with respect to silica), GMA was changed to 1650 g (55 μmol / m 2 with respect to silica), and JER113 was changed to 500 g (10 μmol / m 2 with respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 6 m 2 / g, a hydrophobicity of 46, a methacryl group content of 53 μmol / m 2, a temperature of 30 ° C., and a humidity of 80% after storage for 24 hours. The amount of methacryl group was 51 μmol / m 2 and the storage stability was 96%. The viscosity of the resin composition was 58 Pa · s. The adhesive strength after curing was 66N.

Example 6
In Example 1, the amount of GMA treatment agent was changed to 900 g (30 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 6 m ² / g, a hydrophobicity of 50, a methacrylic group content of 29 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 29 μmol / m ² and the storage stability was 100%. The viscosity of the resin composition was 55 Pa · s. The adhesive strength after curing was 60N.

Example 7
In Example 1, JER806 (5μmol ^/ m 2 with respect to the silica) is 350g, (3μmol ^/ m 2 with respect to the silica) GMA is 90 g, changed JER113 is a 120g (2.5μmol / ^{m 2} with respect to the silica) It was. Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 57, a methacryl group content of 3 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 3 μmol / m ² and the storage stability was 100%.
The viscosity of the resin composition was 41 Pa · s. The adhesive strength after curing was 38N.

Example 8
In Example 1, JER806 was changed to 140 g ( ² μmol / m ^{2 with} respect to silica), GMA was changed to 30 g (1 μmol / m ^{2 with} respect to silica), and JER113 was changed to 50 g (1 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The resulting surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 58, a methacryl group content of 0.9 μmol / m ² , a temperature of 30 ° C., and a humidity of 80%. The amount of methacrylic group after storage for 0.9 hours was 0.9 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 34 Pa · s. The adhesive strength after curing was 34N.

Example 9
In Example 1, the amount of the HMDS treatment agent was changed to 67 g ( ² μmol / m ^{2 based on} silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 36, a methacryl group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 43 Pa · s. The adhesive strength after curing was 51N.

Example 10
In Example 1, the amount of HMDS treatment agent was changed to 50 g (1.5 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 18, a methacryl group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 58 Pa · s. The adhesive strength after curing was 49N.

Example 11
In Example 1, the amount of the HMDS treatment agent was changed to 33 g (1 μmol / m ^{2 based on} silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle diameter of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 7, a methacryl group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 63 Pa · s. The adhesive strength after curing was 49N.

Example 12
In Example 1, initially the JER806 70g (1μmol ^/ m 2 based on the silica), the GMA 30g (1μmol ^/ m 2 based on the silica), the JER113 25g (0.5μmol ^{/ m} 2 with respect to the silica) The solution was dropped with a peristaltic pump and heated at 110 ° C. for 3 hours. After the above treatment, 200 g of HMDS (6 μmol / m ^{2 with} respect to silica) peristaltic pump was added dropwise, and the mixture was heated at 110 ° C. for 3 hours for heat treatment.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 56, a methacryl group content of 0.9 μmol / m ² , a temperature of 30 ° C., and a humidity of 80%. The amount of methacrylic group after storage for 0.9 hours was 0.9 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 35 Pa · s. The adhesive strength after curing was 32N.

Example 13
In Example 1, JER806 was not used, the amount of GMA treatment agent was changed to 600 g (20 μmol / m ^{2 with} respect to silica), and JER113 was changed to 500 g (10 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 51, a methacryl group content of 9 μmol / m ² , a temperature of 30 ° C., and a humidity of 80%, and stored for 24 hours. The amount of methacrylic groups later was 9 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 33 Pa · s. The adhesive strength after curing was 50N.

Example 14
In Example 13, GMA was changed to GA540g (20 μmol / m ^{2 with} respect to silica). Otherwise, the surface treatment and evaluation of silica were performed in the same manner as in Example 13.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 52, an acrylic group content of 8 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of the later acrylic group was 8 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 39 Pa · s. The adhesive strength after curing was 51N.

Example 15
In Example 13, the amount of HMDS treatment agent was changed to 33 g (1 μmol / m ^{2 with} respect to silica). Otherwise, the surface treatment and evaluation of silica were performed in the same manner as in Example 13.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 9, a methacryl group content of 8 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 8 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 61 Pa · s. The adhesive strength after curing was 47N.

Example 16
In Example 13, first, 60 g of GMA ( ² μmol / m ^{2 with} respect to silica) and 50 g of JER113 (1 μmol / m ^{2 with} respect to silica) were dropped with a peristaltic pump, and heat treatment was performed by maintaining at 110 ° C. for 3 hours. . After the above treatment, 200 g of HMDS (6 μmol / m ^{2 with} respect to silica) peristaltic pump was added dropwise, and the mixture was heated at 110 ° C. for 3 hours for heat treatment.
The obtained surface-treated silica has an average particle diameter of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 57, a methacryl group content of 0.8 μmol / m ² , a temperature of 30 ° C., and a humidity of 80%. The amount of methacrylic groups after storage for a period of time was 0.8 μmol / m ² , and the storage stability was 100%.

  The viscosity of the resin composition was 38 Pa · s. The adhesive strength after curing was 33N.

Example 17
In Example 1, Sun Seal SS-04 was changed to Sun Seal SS-10 (silica particles having an average particle diameter of 1.0 μm and a specific surface area of 3 m ² / g). Treating agent amount, HMDS is 85g (6μmol ^/ m 2 relative to silica), JER806 (10μmol ^/ m 2 with respect to the silica) is 300g, (10μmol ^/ m 2 with respect to the silica) GMA is 130g, JER113 is 105g (5 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 1.0 μm, a specific surface area of 3 m ² / g, a hydrophobicity of 47, a methacryl group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 11 Pa · s. The adhesive strength after curing was 39N.

Example 18
In Example 1, Sun Seal SS-04 was changed to Silfill NSS-3N (silica particles having an average particle diameter of 0.1 μm and a specific surface area of 30 m ² / g). Treating agent amount, HMDS is 860g (6μmol ^/ m 2 relative to silica), JER806 is 3000g (10μmol ^/ m 2 relative to silica), (10μmol ^/ m 2 with respect to the silica) GMA is 1280g, JER113 is 1070g (5 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.1 μm, a specific surface area of 27 m ² / g, a hydrophobicity of 58, a methacryl group content of 9 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 9 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 140 Pa · s. The adhesive strength after curing was 59N.

Example 19
In Example 1, Sun Seal SS-04 was changed to Excelica UF310 (silica particles having an average particle diameter of 3 μm and a specific surface area of 2 m ² / g). Treating agent amount, HMDS is 55g (6μmol ^/ m 2 relative to silica), JER806 is (10 .mu.mol ^/ m 2 based on the silica) 200 g, GMA is 85g (10μmol ^/ m 2 relative to silica), JER113 is 70g (5 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle diameter of 3 μm, a specific surface area of 2 m ² / g, a hydrophobicity of 44, a methacryl group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% after storage for 24 hours. The amount of methacryl group was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 9 Pa · s. The adhesive strength after curing was 43N.

Example 20
In Example 1, Sunseal SS-04 was changed to Sunseal TSP-0156 (silica titania particles having an average particle diameter of 0.1 μm and a specific surface area of 28 m ² / g). Treating agent amount, HMDS is 800g (6μmol ^/ m 2 relative to silica), JER806 is 2800g (10μmol ^/ m 2 relative to silica), GMA is 1200g (10μmol ^/ m 2 relative to silica), JER113 is 1000g (5 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica titania has an average particle size of 0.1 μm, a specific surface area of 25 m ² / g, a hydrophobicity of 54, a methacryl group content of 10 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacryl groups after storage was 10 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 156 Pa · s. The adhesive strength after curing was 55N.

Example 21
In Example 1, only the surface treatment with an epoxy polymerizable composition in which JER806, GMA, and JER113 were mixed as the surface treatment agent was performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 0, a methacryl group content of 9 μmol / m ² , a temperature of 30 ° C., and a humidity of 80% for 24 hours. The amount of methacrylic groups later was 9 μmol / m ² and the storage stability was 100%.

  The viscosity of the resin composition was 58 Pa · s. The adhesive strength after curing was 47N.

Comparative Example 1
Using Sun Seal SS-04 without surface treatment, the applied physical properties were evaluated.

  The viscosity of the resin composition was 66 Pa · s. The adhesive strength after curing was 15N.

Comparative Example 2
In Example 1, the surface treatment was performed using only the surface treatment agent HMDS.

The obtained surface-treated silica had an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, and a hydrophobicity of 63.

  The viscosity of the resin composition was 35 Pa · s. The adhesive strength after curing was 17N.

Comparative Example 3
In Example 1, the surface treatment was performed with MPTMS alone, and the amount of the treatment was 520 g (10 μmol / m ^{2 with} respect to silica).
The obtained surface-treated silica has an average particle size of 1.2 μm, a specific surface area of 7 m ² / g, aggregates, a hydrophobicity of 0, a methacryl group content of 9 μmol / m ² , a temperature of 30 ° C., and a humidity of 80%. The amount of methacrylic group after storage for 2 hours was 2 μmol / m ² and the storage stability was 22%.

  The viscosity of the resin composition was 33 Pa · s. The adhesive strength after curing was 25N.

Comparative Example 4
In Example 1, JER806 was changed to 7000 g (100 μmol / m ^{2 with} respect to silica), GMA was changed to 3000 g (100 μmol / m ^{2 with} respect to silica), and JER113 was changed to 2500 g (50 μmol / m ^{2 with} respect to silica). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 2.1 μm, a specific surface area of 6 m ² / g and aggregation, a hydrophobicity of 23, a methacryl group content of 94 μmol / m ² , a temperature of 30 ° C., and a humidity of 80%. The amount of methacrylic groups after storage for 90 hours was 90 μmol / m ² and the storage stability was 96%.

  The viscosity of the resin composition was 55 Pa · s. The adhesive strength after curing was 68N.

Comparative Example 5
In Example 1, 7 g of JER806 (0.1 μmol / m ^{2 with} respect to silica), 3 g of GMA (0.1 μmol / m ^{2 with} respect to silica), and 2.5 g of JER113 (0.05 μmol with respect to silica) / M ² ). Others were the same as in Example 1, and the surface treatment and evaluation of silica were performed.
The obtained surface-treated silica has an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 59, a methacryl group content of 0.1 μmol / m ² , a temperature of 30 ° C., and a humidity of 80%. The amount of methacryl groups after storage for 0.1 hours was 0.1 μmol / m ² , and the storage stability was 100%.

  The viscosity of the resin composition was 64 Pa · s. The adhesive strength after curing was 18N.

Comparative Example 6
In Example 1, 120 g of GMA (4 μmol / m ^{2 based on} silica), JER806 and JER113, 11 g of divinylbenzene (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., DVB960, hereinafter DVB) (0.4 μmol / m ^{2 based on} silica) ), T-butylperoxy-2-ethylhexanoate (manufactured by NOF Co., Ltd., perbutyl O, hereinafter referred to as perbutyl O) was changed to 18 g (0.4 μmol / m ^{2 with} respect to silica) and subjected to acrylic polymerization. The surface treatment and evaluation of silica were carried out in the same manner as in 1.
The obtained surface-treated silica had an average particle size of 0.4 μm, a specific surface area of 7 m ² / g, a hydrophobicity of 60, and a methacryl group content of 0 μmol / m ² .

  The viscosity of the resin composition was 34 Pa · s. The adhesive strength after curing was 17N.

Comparative Example 7
Using Sun Seal SS-10 without surface treatment, applied physical properties were evaluated.

  The viscosity of the resin composition was 12 Pa · s. The adhesive strength after curing was 13N.

Comparative Example 8
Sylfil NSS-3N without surface treatment was used, and applied physical properties were evaluated.

  The viscosity of the resin composition was 920 Pa · s. The adhesive strength after curing was 18N.

Comparative Example 9
The applied physical properties were evaluated using Excelica UF310 without surface treatment.

  The viscosity of the resin composition was 10 Pa · s. The adhesive strength after curing was 13N.

From the above examples and comparative examples, at least a part of the surface of the metal oxide particles is coated with an epoxy polymer having a (meth) acryl group, and the abundance of the (meth) acryl group is 0.5 to 60 μmol / m. ^In Examples 1 to 21 in the range of ² , the aggregated particles were few, the viscosity at the time of the resin composition was low, and the adhesive strength after curing was high, whereas the untreated metal oxide particles and the silane coupling method were used. Introducing (meth) acrylic groups, and in Comparative Examples 1 to 9 of the (meth) acrylic group-containing polymer-coated particles not satisfying the range of the (meth) acrylic group amount in the above range, aggregation occurs, and the viscosity of the resin composition There are problems such as high and low adhesive strength after curing.

  Tables 1 and 2 collectively show the surface treatment conditions and physical properties of the (meth) acrylic group-containing polymer-coated particles in Examples 1 to 21 and Comparative Examples 1 to 9.

Claims (8)

At least a part of the metal oxide particle surface is coated with an epoxy polymer having a (meth) acryl group, and the amount of the (meth) acryl group is 0.5 to 30 μmol / m ² per unit surface area of the particle. Ah is, volume-reduced cumulative 50% diameter measured by a laser diffraction scattering method (D50 diameter), characterized in 0.1~10μm der Rukoto, (meth) metal oxide coated with a polymer having an acrylic group particles .   The metal oxide particles coated with a polymer having a (meth) acryl group according to claim 1, wherein the hydrophobicity is 5 to 60.   The metal oxide particles coated with a polymer having a (meth) acryl group according to claim 1 or 2, wherein the metal oxide particles are silica-based particles. Epoxy groups and in the molecule (meth) monomers having One not a one, respectively an acrylic group, and mixing the epoxy polymerizable composition comprising an epoxy curing agent and the metal oxide particles, epoxy polymerizable composition to obtain a metal oxide particles whose surface is coated with an object, then the epoxy groups Ru by cationic polymerization, (meth) coated with a polymer having an acryl group, volume-reduced cumulative 50% diameter measured by a laser diffraction scattering method ( A method for producing metal oxide particles having a D50 diameter of 0.1 to 10 μm ,
The coating amount of the metal oxide particles by the epoxy polymerizable composition is introduced by a polymer obtained by cationic polymerization of the epoxy group with a (meth) acryl group of 0.5 to 30 μmol / m ² per unit surface area of the particle. is an amount that is,
The method for producing metal oxide particles coated with a polymer having a (meth) acrylic group according to claim 1. The epoxy polymerizable composition, the content of the monomer having an epoxy group and a (meth) an acrylic group One not a one each in one molecule in the total composition is intended 15 to 80 wt%, the epoxy The manufacturing method of the metal oxide particle | grains coat | covered with the polymer which has a (meth) acryl group of Claim 4 which mixes 0.01-20 mass parts of polymeric composition with respect to 100 mass parts of said metal oxides. . 1 and an epoxy group in the molecule (meth) monomers having One not a one, respectively of acrylic group is glycidyl (meth) acrylate, coated with a polymer having a claim 4 or claim 5, wherein the (meth) acrylic group Method for producing metal oxide particles .   7. The particle according to claim 4, wherein the particle having a hydrophobicity of 5 to 60 according to claim 2 is obtained by using a metal oxide particle whose surface has been previously hydrophobized. 7. A method for producing metal oxide particles coated with a polymer having a (meth) acryl group. After the epoxy group is cationic polymerization, the resulting particles by subjecting the hydrophobic treatment of the surface, the hydrophobicity of claim 2 wherein obtaining the particles of 5 to 60, claim 4-6 The manufacturing method of the metal oxide particle | grains coat | covered with the polymer which has a (meth) acryl group of one term | claim.

Images