JP5442194B2 - Surface-modified mesoporous silica, and slurry composition for resin addition, resin filler, resin composition, high-frequency electronic component and high-frequency circuit substrate using the same - Google Patents

Description

  The present invention relates to a surface-modified mesoporous silica, a slurry composition for resin addition using the same, a filler for a resin, and a resin composition, and is suitable for use as an insulating substrate for an IC.

  In recent years, in the technical field of information communication equipment, as the amount of information processed increases, the frequency of electric signals used is further increased. For this reason, a low dielectric constant substrate material with low dielectric loss at high frequencies is required. In order to achieve such a low dielectric constant of the insulator, various methods have been proposed in which air (relative dielectric constant = 1) is made porous by containing an insulating material.

  For example, in Patent Document 1, a fine powder of calcium carbonate is used as a template, silica is deposited around it, and then calcium carbonate is dissolved with an acid, whereby the pore distribution measured by mercury porosimetry is 2 nm or more. Porous silica is obtained in which no pores are detected. And the resin substrate of a low dielectric constant is obtained by adding this to an epoxy resin.

  In Patent Document 2, silica is precipitated around a micelle made of a surfactant as a template, and then the surfactant is removed to obtain porous mesoporous silica, whereby silica having a low dielectric constant is obtained. A film is obtained. Further, an idea has been proposed in which a silanol group existing inside the pores of mesoporous silica having an average pore diameter of 2 to 50 nm is chemically modified with a compound having a trialkylsilyl group to further reduce the dielectric constant (patent) (Refer to literature 2, paragraph number 0003)

JP 2007-56158 A JP 2002-53773 A

  However, according to the test results of the inventors, it has been found that even if the silanol group present on the surface of mesoporous silica is chemically modified with a silylating agent, the dielectric constant may not be lowered as expected. .

  The present invention has been made in view of the above-described conventional situation, and has been sufficiently modified with silanol groups present on the surface of mesoporous silica and has a low dielectric constant, surface-modified mesoporous silica, and the use thereof It is an object to provide a slurry composition for resin addition, a filler for resin, and a resin composition.

  In order to solve the above-mentioned problems, the present inventors have conducted further detailed studies on chemical modification of silanol groups present on the surface of mesoporous silica. As a result, it has been found that if mesoporous silica having a pore size of a certain size or more is chemically modified with a hydrophobic functional group, the modification rate becomes extremely high and the dielectric constant can be greatly reduced. It came.

  That is, the surface-modified mesoporous silica of the present invention is characterized in that silanol groups present on the surface of mesoporous silica having an average pore size of 1.5 nm or more are chemically modified with a hydrophobic functional group.

また、化学修飾される疎水性の官能基は、細孔径よりもはるかに小さいため、修飾前後で細孔径にほとんど変化はなく、細孔内部に存在する空気によって誘電率が小さくなる効果は維持される。
したがって、本発明の表面修飾メソポーラスシリカは、メソポーラスシリカの表面に存在するシラノール基の化学修飾が充分なされており、誘電率も低くなる。 In the surface-modified mesoporous silica of the present invention, the silanol group is chemically modified with a hydrophobic functional group, so that the polarity on the surface is reduced and the amount of water adsorbed which increases the dielectric constant is reduced. The rate is smaller than before chemical modification. Moreover, since the average pore diameter of mesoporous silica is as large as 1.5 nm or more (preferably 2.7 nm or more), the chemical modification reagent is easy to enter the pores and is modified with a hydrophobic functional group. This increases the rate and contributes to the effect of lowering the dielectric constant even inside the pores. This is supported because the pressure ΔP required when the liquid passes through the communicating pores is inversely proportional to the pore radius as shown in the following equation (1).

In addition, since the hydrophobic functional group that is chemically modified is much smaller than the pore diameter, there is almost no change in the pore diameter before and after modification, and the effect of reducing the dielectric constant by the air existing inside the pore is maintained. The
Therefore, the surface-modified mesoporous silica of the present invention is sufficiently chemically modified with silanol groups present on the surface of the mesoporous silica, and has a low dielectric constant.

As a reagent for modifying the silanol group, any reagent that has a hydrophobic functional group and chemically bonds to the silanol group can be used. Examples of such a modifying reagent include a silane coupling agent, a titanium coupling agent, a zirconia coupling agent, and alcohol. The present inventors have confirmed that the dielectric constant is surely reduced when treated with a silane coupling agent. Of the silane coupling agents, organosilazane is particularly preferable. Most preferred is hexamethyldisilazane. Hexamethyldisilazane (CH ₃ ) ₃ SiNHSi (CH ₃ ) ₃ is a disilazane H ₃ SiNHSiH ₃ in which H bonded to Si is replaced by a methyl group, and is easy to handle without explosive or corrosive properties. In addition, it is inexpensive because it is used as a surfactant for photoresist coating in the electronics industry.

  The pores of mesoporous silica may have an elongated tube shape arranged in a certain direction. In this case, air having an effect of lowering the dielectric constant is also arranged in a certain direction, so that a new dielectric material having anisotropy in the dielectric constant is obtained.

The average pore diameter of mesoporous silica is preferably 50 nm or less. When the average pore diameter of mesoporous silica exceeds 50 nm, preparation is difficult and the structure is not stable. Particularly preferred is 20 nm or less.
The specific surface area of the surface-modified mesoporous silica of the present invention is preferably from 300m ² / g~2000m ² / g in order to sufficiently exhibit the effect of lowering the dielectric ^constant, 500m ² / g~2000m 2 / g, more preferably, 600m ² / g~2000m ² / g being most preferred.
Further, the pore volume of the surface-modified mesoporous silica of the present invention is preferably 0.1cm ³ /g~1.0cm ³ / g in order to sufficiently exhibit the effect of lowering the dielectric constant, 0.3 cm ³ / g to more preferably 1.0 cm ³ / g, and most preferably 0.6cm ³ /g~1.0cm ³ / g.

  In the surface-modified mesoporous silica of the present invention, the silanol group chemical modification rate can be 50% or more. Moreover, the dielectric constant measured by the perturbation resonator method can be 2.3 or less at a measurement frequency of 1 GHz.

  A slurry composition for resin addition can be produced using the surface-modified mesoporous silica of the present invention. That is, the slurry composition for resin addition of the present invention is characterized in that the surface-modified mesoporous silica of the present invention is dispersed in an organic solvent. In this slurry composition for resin addition, the surface-modified mesoporous silica of the present invention is dispersed in an organic solvent, so that the surface-modified mesoporous silica is mixed uniformly with the matrix resin as compared with the case where the surface-modified mesoporous silica is directly added to the matrix resin. And the surface-modified mesoporous silica is difficult to become an aggregate. For this reason, a uniform filler can be dispersed in the matrix resin. Further, even if the dispersion concentration of the surface-modified mesoporous silica is high, the viscosity can be kept low, so that the workability in the mixing operation with the matrix resin is improved. As the matrix resin, thermosetting and thermoplastic resins can be widely applied. Specific examples of the matrix resin that can be used include epoxy resin, phenol resin, polyurethane, polyimide, unsaturated polyester, vinyl triazine, crosslinkable polyphenylene oxide, and curable polyphenylene ether.

  The slurry composition for resin addition preferably contains an anti-settling agent for preventing settling of the surface-modified mesoporous silica. This is because it is possible to save or reduce the trouble of stirring the surface-modified mesoporous silica that has settled during use to make it uniform. Examples of such an anti-settling agent include epoxy resins, phenol resins, bismaleimide triazine resins, cyanoester resins, polyamide resins, and copolymers having maleic anhydride as a copolymerization component and derivatives thereof.

  The slurry composition for resin addition preferably contains the surface-modified mesoporous silica in the range of 1 wt% to 50 wt%. When the content of the surface-modified mesoporous silica is less than 1% by weight, the amount of the solvent with respect to the surface-modified mesoporous silica is too large, which is not practical. Moreover, when the content rate of surface modification mesoporous silica exceeds 50 weight%, the dispersibility to resin will fall remarkably.

  The surface-modified mesoporous silica of the present invention can be mixed with a powder usually added to a resin such as silica, talc, mica, calcium carbonate, or the like to form a filler for a resin.

  By incorporating the mesoporous silica of the present invention into an organic resin such as a thermosetting resin or a thermoplastic resin, the resin composition of the present invention can be obtained. The resin composition thus obtained has a low dielectric constant. The thermosetting resin can be one or more selected from epoxy resins, phenol resins, polyurethanes, polyimides, unsaturated polyesters, vinyl triazines, crosslinkable polyphenylene oxides, and curable polyphenylene ethers. Moreover, a hardening | curing agent or a catalyst can also be mix | blended with these thermosetting resin compositions.

  Since the resin composition of the present invention thus obtained has a low dielectric constant, it can be suitably used for high-frequency electronic components and high-frequency circuit substrates.

<Preparation of surface-modified mesoporous silica>
Mesoporous silica, which is a raw material for surface-modified mesoporous silica, is a substance having uniform and regular pores (mesopores) made of silicon dioxide (silica). In the IUPAC, in the catalyst field, pores having a diameter of 2 nm or less are defined as micropores, pores having a diameter of 2 to 50 nm are defined as mesopores, and pores having a diameter of 50 nm or more are defined as macropores. Porous silica having pores and macropores is also defined as mesoporous silica.

  The pore walls of mesoporous silica are amorphous, and as a general production method, a sol-gel method using a surfactant as a template is used. However, mesoporous silica as a raw material is limited to mesoporous silica produced by the production method. Is not to be done. In the sol-gel method, when a surfactant is dissolved in an aqueous solution at a concentration equal to or higher than the critical micelle concentration, micelle particles having a certain size and structure are formed according to the type of the surfactant. When left standing for a while, the micelle particles take a packed structure and become a colloidal crystal. Here, when tetraethoxysilane or the like serving as a silica source is added to the solution and a trace amount of acid or base is added as a catalyst, the sol-gel reaction proceeds in the gaps between the colloidal particles to form a silica gel skeleton. Finally, when fired at a high temperature, the surfactant used as a mold is decomposed and removed to obtain pure mesoporous silica. By changing the type of the surfactant, the size and shape of the pores and the filling structure can be controlled. As typical ones, the MCM series using a small molecular cationic surfactant and the SBA series using a block copolymer are known.

  A specific method for producing mesoporous silica as a raw material is not particularly limited. However, as shown in JP-A-2006-248832, an inorganic material is mixed with an organic raw material and reacted, thereby causing an organic substance to react. A method of removing an organic substance from the obtained complex after forming a complex of an organic substance and an inorganic substance having an inorganic skeleton formed thereon as a template can be employed.

The inorganic raw material is not particularly limited as long as it is a substance containing silicon. Examples of the substance containing silicon include kanemite (NaHSi ₂ O ₅ · 3H ₂ O), sodium disilicate crystal (Na ₂ Si ₂ O ₅ ), macatite (NaHSi ₄ O ₉ · 5H ₂ O), and Iraite (NaHSi). ₈ O ₁₇ · XH ₂ O), magadiite (Na ₂ HSi1 ₄ O ₂₉ · XH ₂ O), Kenyaite (Na ₂ HSi ₂₀ O ₄₁ · XH ₂ O), water glass (silicate soda), glass, amorphous silicic acid Examples thereof include silicon alkoxides such as sodium, tetraethoxysilane (TEOS), tetramethylammonium (TMA) silicate, and tetraethylorthosilicate. Examples of the substance containing silicon other than silicate include silica, silica oxide, and silica-metal composite oxide. You may use these individually or in mixture of 2 or more types.

  Examples of the organic raw material include cationic, anionic, amphoteric and nonionic surfactants. You may use these individually or in mixture of 2 or more types.

  Furthermore, examples of the cationic surfactant used as a template include primary amine salts, secondary amine salts, tertiary amine salts, and quaternary ammonium salts. Among these, quaternary ammonium salts are included. Salts are preferred. Amine salts have poor dispersibility in the alkaline region, so that the synthesis conditions are used only in the acidic range, but the quaternary ammonium salts can be used in both cases where the synthesis conditions are acidic and alkaline. .

  The quaternary ammonium salt used as a template includes octyltrimethylammonium chloride, octyltrimethylammonium bromide, octyltrimethylammonium hydroxide, decyltrimethylammonium chloride, decyltrimethylammonium bromide, decyltrimethylammonium hydroxide, dodecyltrimethylammonium chloride, Dodecyltrimethylammonium bromide, dodecyltrimethylammonium hydroxide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium hydroxide, octadecyltrimethylammonium chloride, octadecyltrimethylammonium bromide, octadecyltrimethylammonium Mhydroxide, behenyltrimethylammonium chloride, behenyltrimethylammonium bromide, behenyltrimethylammonium hydroxide, tetradecyltrimethylammonium chloride, tetradecyltrimethylammonium bromide, tetradecyltrimethylammonium hydroxide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium Examples thereof include alkyl (carbon number 8 to 22) trimethylammonium salt such as hydroxide. You may use these individually or in mixture of 2 or more types.

  Examples of the anionic surfactant used as a template include carboxylate, sulfate ester salt, sulfonate salt and phosphate ester salt. Among them, soap, higher alcohol sulfate ester salt, higher alkyl ether sulfate Examples include ester salts, sulfated oils, sulfated fatty acid esters, sulfated olefins, alkylbenzene sulfonates, alkylnaphthalene sulfonates, paraffin sulfonates, and higher alcohol phosphate esters. You may use these individually or in mixture of 2 or more types.

  Furthermore, examples of the amphoteric surfactant used as a template include sodium laurylaminopropionate, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine. You may use these individually or in mixture of 2 or more types.

  Non-ionic surfactants used as templates include polyoxyethylene alkyl ether, polyoxyethylene secondary alcohol ether, polyoxyethylene alkylphenyl ether, polyoxyethylene sterol ether, polyoxyethylene lanolin acid derivative, polyoxyethylene Examples include ether type compounds such as polyoxypropylene alkyl ether, polypropylene glycol, and polyethylene glycol, and nitrogen-containing types such as polyoxyethylene alkylamine. You may use these individually or in mixture of 2 or more types.

  When a surfactant is used as the organic raw material and pores are formed using the surfactant as a template, micelles can be used as the template. Also, by controlling the alkyl chain length of the surfactant, the diameter of the template can be changed and the diameter of the pores to be formed can be controlled. Furthermore, by adding a relatively hydrophobic molecule such as trimethylbenzene or tripropylbenzene together with a surfactant, the micelles expand and larger pores can be formed. By utilizing these methods, it is possible to form pores having a size optimal for the menthol to be supported.

  When mixing an inorganic raw material and an organic raw material, an appropriate solvent may be used. Although it does not specifically limit as a solvent, Water, alcohol, etc. are mentioned.

The mixing method of the inorganic raw material and the organic raw material is not particularly limited, but after adding ion-exchanged water having a weight ratio of 2 times or more to the inorganic raw material and stirring at 40 to 80 ° C. for 1 hour or longer, the organic raw material is added. Are preferably mixed.
The mixing ratio of the inorganic raw material and the organic raw material is not particularly limited, but the ratio (weight ratio) of the inorganic raw material to the organic raw material is preferably 0.1: 1 to 5: 1, more preferably 0.1: 1 to 1. 3: 1.

  The reaction between the inorganic raw material and the organic raw material is not particularly limited. However, the reaction is preferably performed at a pH of 11 or more for 1 hour or more, and after adjusting the pH to 8.0 to 9.0, the reaction may be performed for 1 hour or more. preferable.

  Examples of the method for removing the organic substance from the complex of organic substance and inorganic substance include a method in which the complex is collected by filtration, washed with water and dried, then baked at 400 to 600 ° C., and extracted with an organic solvent. .

As reagents for chemically modifying silanol groups present on the surface of mesoporous silica with hydrophobic functional groups, silane coupling agents, titanium coupling agents, and zirconia coupling agents, which are well known as chemical modifiers, are used. A coupling agent, an aluminum coupling agent, a chromium coupling agent, a zircoaluminum coupling agent, alcohol, or the like can be used. Specific examples of silane coupling agents having a hydrophobic functional group include trialkoxymonoalkoxysilanes and derivatives in which hydrogen of the alkyl group is substituted with fluorine, trialkoxymonoalkenylsilanes, dialkyldisilazanes, diphenyls. Disilazane and the like can be mentioned.
In order to chemically modify the silanol group present on the mesoporous silica surface with the above-described chemical modifier with a hydrophobic functional group, a method generally performed for each chemical modifier may be performed. For example, in the case of a silane coupling agent, water is added to the coupling agent to hydrolyze it, then a catalyst such as alcohol and acetic acid is added and dissolved in a solvent to prepare a solution, and the filler is immersed in this solution. The surface treatment may be performed.

<Preparation of slurry composition for resin addition>
In order to disperse the surface-modified mesoporous silica in an organic solvent, a device such as a triple roll, ball mill, bead mill, high-pressure homogenizer, spike mill, jet mill, ultrasonic disperser, various mixers, kneader may be used. In addition, in order to prevent modification | denaturation of a slurry composition, it is desirable to prepare in non-oxidizing atmosphere, such as nitrogen atmosphere.

  The viscosity of the prepared slurry composition is also an important guide for preparation. If the viscosity is low, the content ratio of the surface-modified mesoporous silica in the slurry composition is small, which contributes to a deterioration in the efficiency of transportation and the like of the prepared slurry composition. On the other hand, when the viscosity is too high, workability at the time of dispersing into the matrix resin is deteriorated.

  The proper viscosity is desirably in the range of 10 to 2000 cps in the measurement performed at 25 ° C. using an E-type viscometer. In addition, as a method for simply measuring the viscosity, a method of measuring the time during which the slurry composition freely falls and flows out from a 25 mL measuring pipette may be employed. It is desirable that the slurry composition is prepared in such a range that it completely flows out.

  In order to suppress sedimentation of surface-modified mesoporous silica and formation of cake (precipitate aggregate) during storage, it is desirable to add an anti-settling agent. When an anti-settling agent is added, the viscosity becomes slightly higher, and within the above range, the viscosity is 100 cps or more by the E-type viscometer. By doing so, almost no cake is formed.

  As the anti-settling agent, a part of the resin constituting the matrix resin can be used. Specifically, at least one selected from an epoxy resin, a phenol resin, a bismaleimide triazine (BT) resin, a cyanoester resin, a polyamic acid, a maleic anhydride copolymer, and a derivative thereof is desirable. What is necessary is just to employ | adopt a suitable thing suitably in balance with matrix resin. The anti-settling agent may be added at the time of preparing the slurry composition and dissolved in an organic solvent. In addition, what is necessary is just to determine the addition amount of an anti-settling agent on the basis of the viscosity of a slurry composition, as mentioned above.

  When considering the workability and storage stability as described above, the content ratio of the surface-modified mesoporous silica in the slurry composition is specifically 1 wt% or more and 50 wt% or less when the entire slurry is 100 wt%. Is desirable.

<Preparation of resin composition containing surface-modified mesoporous silica>
The resin composition of this invention is obtained by adding the slurry composition for resin addition mentioned above to the solution which melt | dissolved matrix resin in the organic solvent, mixing uniformly, and volatilizing the organic solvent. The matrix resin is not limited in its kind, and can be widely applied to thermosetting or thermoplastic resins. Specific examples of usable matrix resins include epoxy resins, polyimides, cyanoester resins, BT resins, and polyolefins. In order to evaporate the organic solvent, for example, it is coated by a method such as spray, roll coater, spin coater, casting, dipping and the like, and after the solvent is evaporated, it is cured to obtain a film-shaped resin molded product. These film-shaped resin molded products can be used for various applications such as electronic parts, adhesives, heat-resistant films, protective films, and the like.

The average pore diameter, specific surface area, and pore volume can be calculated from a nitrogen adsorption isotherm by a known BET method. More specifically, the average pore diameter can be calculated by a known BJH method, BET method, t method, DFT method, etc., and the specific surface area can be calculated by a known BET method, t method, α method, or the like. The pore volume can be calculated by a known BJH method, BET method, t method, or the like. As for the chemical modification ratio of silanol groups, before and after chemical modification, and the absorption intensity based on SiO-H stretching vibration in the vicinity of 3700 cm ^-1 in the infrared absorption spectrum, based on the SiO stretching vibration in the vicinity of 1,000 to ^-1 It can be obtained from the ratio with the absorption intensity.

  The regularity of the pores can be confirmed by X-ray diffraction or the like. From the perturbation formula, it can be measured by a technique such as a perturbation resonance method for measuring the complex dielectric constant and complex permeability of the sample. X-ray diffraction can be measured with an X-ray diffractometer (RINT ULTIMA II, manufactured by Rigaku Corporation).

  The average pore diameter, specific surface area, and pore volume of the surface-modified mesoporous silica in the present invention can be calculated from a nitrogen adsorption isotherm by a known BET method. More specifically, the average pore diameter can be calculated by a known BJH method, BET method, t method, DFT method, etc., and the specific surface area can be calculated by a known BET method, t method, α method, or the like. The pore volume can be calculated by a known BJH method, BET method, t method, or the like.

Hereinafter, examples that further embody the present invention will be described in detail.
Example 1
Preparation of mesoporous silica 50 g of No. 1 sodium silicate (SiO ₂ / Na ₂ O = 2.00) manufactured by Nippon Chemical Industry Co., Ltd., behenyltrimethylammonium chloride [C ₂₂ H ₄₅ N (CH ₃ ) ₃ Cl] 0 . It was dispersed in 1000 ml of 1M aqueous solution and heated at 70 ° C. with stirring for 3 hours. Thereafter, 2N hydrochloric acid was added while heating and stirring at 70 ° C., the pH of the dispersion was lowered to 8.5, and the mixture was further heated and stirred at 70 ° C. for 3 hours. The solid product was once filtered, dispersed again in 1000 ml of ion exchange water, and stirred. This filtration / dispersion stirring was repeated 5 times, followed by drying at 40 ° C. for 24 hours. The dried solid product was calcined in air at 550 ° C. for 6 hours to obtain mesoporous silica A. The average pore diameter of the obtained mesoporous silica A was calculated from the nitrogen adsorption isotherm by the known BET method (BJH method) and was 4.2 nm.
When the specific surface area (BET method) and pore volume (BJH method) of mesoporous silica A were calculated by a known nitrogen adsorption method, the specific surface area was 1159.9 m ² / g and the pore volume was 1.02 cm ³ / g. It was.

Chemical modification 1 g of this mesoporous silica A is measured and added to 9 g of toluene, followed by stirring. Then, 2 g of HMDS is added, and stirring with ultrasonic waves is performed for 30 minutes. The reaction mixture thus obtained was dried in an air atmosphere at 160 ° C. for 1 hour to obtain the surface-modified mesoporous silica of Example 1. It was 3.4 nm when the average pore diameter of the obtained surface modification mesoporous silica was computed from the nitrogen adsorption isotherm by the well-known BET method (BJH method).

When the specific surface area (BET method) and pore volume (BJH method) of the surface-modified mesoporous silica of Example 1 were calculated by a known nitrogen adsorption method, the specific surface area was 743.8 m ² / g and the pore volume was 0.00. It was 68 cm ³ / g.

  Further, when the X-ray diffraction pattern of the obtained surface-modified mesoporous silica was measured, it had one or more peaks at a diffraction angle corresponding to a d value larger than 2.0 nm, and a d value smaller than 1.0 nm. There was no peak at the corresponding diffraction angle.

(Comparative Example 1)
Comparative Example 1 was used as a raw material in the preparation of the surface-modified mesoporous silica of Example 1, and the silanol group was not chemically modified.

(Comparative Example 2)
Comparative Example 2 is silica (Admafine C5 manufactured by Admatechs Co., Ltd.) having no pores and having an average diameter close to a true sphere of 1.5 μm.

(Comparative Example 3)
In Comparative Example 3, the silica of Comparative Example 2 was surface-treated with HMDS by the same method as in Example 1.

<Evaluation>
-Measurement of dielectric constant-
The dielectric constant of the surface-treated mesoporous silica of Example 1 and the silica of Comparative Examples 1 to 3 was measured by the perturbation resonator method (measurement frequency was 1 GHz). As a result, as shown in FIG. 1, Comparative Example 1 which is mesoporous silica having a large pore diameter of 4 nm has a dielectric constant of about 1/2 compared to Comparative Example 2 which is silica without pores. When this was surface-treated with HMDS, the dielectric constant further decreased significantly. From this, it was found that the surface-treated mesoporous silica of Example 1 is useful as a filler for lowering the dielectric constant. Moreover, it turned out that a dielectric constant does not fall in the comparative example 3 which surface-treated the comparative example 2 which is a silica without a pore by HMDS. The reason for this is that in Example 1, the surface area is increased by the pores of mesoporous silica, and the effect of the surface treatment appears remarkably, whereas the silica of Comparative Example 2 has no pores, so the number of surface silanol groups This is considered to be because even if those silanol groups are surface-treated with HMDS, they do not reach the degree of contribution to the dielectric constant.

-Measurement of infrared absorption spectrum (IR)-
IR of Example 1 and Comparative Example 1 was measured. As a result, as shown in FIG. 2, in Comparative Example 1 before surface chemical modification with HMDS, the absorption peak based on SiOH stretching that existed in the vicinity of 3700 cm ⁻¹ disappeared in Example 1 and was newly increased to 3000 cm ^−. It can be seen that an absorption peak based on CH stretching vibration near ¹ appears. From these results, it was found that in Example 1, the silanol group was chemically modified by HMDS. Furthermore, the chemical modification ratio of silanol groups, and the absorption intensity based on SiO-H stretching vibration in the vicinity of 3700 cm ^-1, a hydroxyl group obtained from the ratio of the absorption intensity based on SiO stretching vibration in the vicinity of 1,000 to ^-1 The modification rate was estimated to be 80% or more.

(Example 2)
Preparation of mesoporous silica Powdered sodium silicate (SiO ₂ / Na ₂ O = 2.0) was calcined in air at 700 ° C. for 6 hours to form sodium disilicate crystals, and 50 g of these crystals were dispersed in 500 ml of water. After stirring for 3 hours, the solid content was collected by filtration to obtain kanemite crystals. An amount equivalent to 50 g in terms of dry weight of this kanemite crystal was added and dispersed in 1000 ml of a 0.1 M hexadecyltrimethylammonium bromide aqueous solution without drying, followed by stirring at 70 ° C. for 3 hours. Thereafter, the pH was adjusted to 8.5 and the mixture was stirred at 70 ° C. for 3 hours.
This filtration / dispersion stirring was repeated 5 times, followed by drying at 40 ° C. for 24 hours. Mesoporous silica B was obtained by baking the dried solid product at 550 degreeC in the air for 6 hours. The average pore diameter of the obtained mesoporous silica B was calculated from the nitrogen adsorption isotherm by the known BET method (BJH method) and was 2.7 nm.
When the specific surface area (BET method) and pore volume (BJH method) of mesoporous silica C were calculated by a known nitrogen adsorption method, the specific surface area was 1027.6 m ² / g and the pore volume was 0.63 cm ³ / g. It was.

The chemical modification thus obtained mesoporous silica B as a raw material, using HMDS, were chemical modification in the same manner as in Example 1.

  It was 2.2 nm when the average pore diameter of the obtained surface modification mesoporous silica was calculated from the nitrogen adsorption isotherm by the well-known BET method (BJH method).

When the specific surface area (BET method) and pore volume (BJH method) of the surface-modified mesoporous silica were calculated by a known nitrogen adsorption method, the specific surface area was 610.8 m ² / g and the pore volume was 0.38 cm ³ / g. there were.

  When the X-ray diffraction pattern of the obtained surface-modified mesoporous silica was measured, it had one or more peaks at a diffraction angle corresponding to a d value larger than 2.0 nm, and corresponded to a d value smaller than 1.0 nm. There was no peak at the diffraction angle.

( Reference Example 1 )
Preparation of mesoporous silica 50 g of water glass No. 1 (SiO ₂ / Na ₂ O = 2.00) manufactured by Nippon Chemical Industry Co., Ltd. was used as a surfactant, n-decyltrimethylammonium chloride [C ₁₀ H ₂₁ N (CH ₃ ) was dispersed in 0.1M aqueous 1000ml of ₃ Cl], it was heated with stirring for 3 hours at 70 ° C.. Thereafter, 2N hydrochloric acid was added while heating and stirring at 70 ° C., the pH of the dispersion was lowered to 8.5, and the mixture was further heated and stirred at 70 ° C. for 3 hours. The solid product was once filtered, dispersed again in 1000 ml of ion exchange water, and stirred. This filtration / dispersion stirring was repeated 5 times, followed by drying at 40 ° C. for 24 hours. The dried solid product was calcined in air at 550 ° C. for 6 hours to obtain mesoporous silica C. When the average pore diameter of the obtained mesoporous silica C was calculated from the nitrogen adsorption isotherm by the known BET method (BJH method), it was 1.8 nm.
When the specific surface area (BET method) and pore volume (BJH method) of mesoporous silica A were calculated by a known nitrogen adsorption method, the specific surface area was 1019.0 m ² / g, and the pore volume was 0.373 cm ³ / g. It was.

Chemical modification thus obtained mesoporous silica C as a raw material, using HMDS, were chemical modification in the same manner as in Example 1.

( Reference Example 2 )
In Reference Example 2, the average pore diameter as mesoporous scan silica as a raw material is 4.2 nm, the average particle diameter was used 11 [mu] m (manufactured by Taiyo Kagaku Co., Ltd. NPM4). Further, trimethylsilane (CH ₃ ) ₃ SiH (hereinafter referred to as “TMS”) was used for chemical modification. Others are the same as the method of the first embodiment, and the description is omitted.

<Evaluation>
-Measurement of infrared absorption spectrum (IR)-
4 to the surface-modified mesoporous scan silica of Example 2 and Reference Example 2 as shown in Figure 6, disappeared absorption peak based on the SiOH stretching that existed in the vicinity of 3700 cm ^-1, newly 3000 cm ^-1 vicinity of It can be seen that an absorption peak based on CH stretching vibration appears. From these results, it was found that in Example 2 and Reference Example 2 , the silanol group was chemically modified by HMDS or TMS. However, Reference Example 1 (i.e., the 1.8 nm of the mesoporous scan silica those that have been treated with HMDS) in, depending on the process of HMDS absorption peak based on the CH stretching vibration in the vicinity of newly 3000 cm ^-1 is expressed However, the peak was small, and an absorption peak based on SiOH stretching that existed in the vicinity of 3700 cm ⁻¹ remained. This is the pore size 1.8 nm of mesoporous scan silica, by treatment with HMDS, it shows that the modification ratio of the silanol groups is small. This is considered to be because HMDS does not penetrate into the back of the pore because the pore diameter is small.

-Measurement of X-ray diffraction (XRD)-
The surface-modified mesoporous scan silica of Example 1 was measured XRD. As a result, as shown in FIG. 7, peaks appeared at 2θ of 1.1 ° and 1.75 °. These peaks are 4 nm and 2.5 nm in terms of d value.

  When the surface-modified mesoporous silica of the present invention is used as a filler for an IC insulating substrate or the like, dielectric loss at high frequencies can be reduced. This provides a material that is extremely useful in the electronics industry.

It is a graph which shows the dielectric constant measurement result of Example 1 and Comparative Examples 1-3. 2 is an infrared absorption spectrum of Example 1 and Comparative Example 1. It is an infrared absorption spectrum of Comparative Example 2 and Comparative Example 3. It is an infrared absorption spectrum before and after the HMDS process in Example 2. It is an infrared absorption spectrum before and after the HMDS process in Reference Example 1 . It is an infrared absorption spectrum after the TMS process in Reference Example 2 . 2 is an X-ray diffraction spectrum of Example 1. FIG.

Claims (16)

Silanol groups present on the surface of mesoporous silica having an average pore diameter of 2.7 nm to 20 nm are chemically modified with hexamethyldisilazane (HMDS), and the dielectric constant measured by the perturbation resonator method is 1 GHz. The surface-modified mesoporous silica is 1.64 or less . The specific surface area of the mesoporous silica is 300m ² / g~2000m ² / g, according to claim 1, wherein the pore volume of the mesoporous silica is 0.1cm ³ /g~1.0cm ³ / g The surface-modified mesoporous silica described.   The surface-modified mesoporous silica according to claim 1 or 2, wherein the pores of the mesoporous silica have an elongated tube shape arranged in a certain direction.   The surface-modified mesoporous silica according to any one of claims 1 to 3, wherein the silanol group has a chemical modification rate of 50% or more. The X-ray diffraction pattern of the surface-modified mesoporous silica has one or more peaks at a diffraction angle corresponding to a d value larger than 2.0 nm, and a peak at a diffraction angle corresponding to a d value smaller than 1.0 nm. The surface-modified mesoporous silica according to any one of claims 1 to 4 , which is not present. A slurry composition for resin addition, wherein the surface-modified mesoporous silica according to any one of claims 1 to 5 is dispersed in an organic solvent. The slurry composition for resin addition according to claim 6 , wherein an anti-settling agent for preventing settling of the surface-modified mesoporous silica is contained. The anti-settling agent is at least one selected from an epoxy resin, a phenol resin, a bismaleimide triazine resin, a cyanoester resin, a polyamide resin, a copolymer having maleic anhydride as a copolymerization component, and a derivative thereof. The slurry composition for resin addition according to claim 7, characterized in that: The slurry composition for resin addition according to any one of claims 6 to 8, wherein the surface-modified mesoporous silica is contained in a range of 1 wt% to 50 wt%. The filler for resin containing the surface modification mesoporous silica of any one of Claims 1 thru | or 5 . The resin composition which made the organic resin contain the surface modification mesoporous silica of any one of Claims 1 thru | or 5 . The resin composition according to claim 11 , wherein the organic resin is at least one selected from a thermosetting resin and a thermoplastic resin. The thermosetting resin, according to claim 12, wherein the epoxy resin, phenol resin, polyurethane, polyimide, unsaturated polyester, vinyl triazine, crosslinkable polyphenylene oxide, that is one or more selected from the curable polyphenylene ether The resin composition described in 1. Furthermore, the hardening | curing agent and / or the catalyst were mix | blended, The resin composition of Claim 12 or 13 characterized by the above-mentioned. A high-frequency electronic component using the resin composition according to any one of claims 11 to 14 . A substrate for a high-frequency circuit using the resin composition according to any one of claims 11 to 14 .

Images