JP2016216348A - Silica particle material and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface treatment method for obtaining a silica particle material introduced with phenylamine and also excellent in treatability.SOLUTION: Provided is a surface treatment method where silica particles are subjected to surface treatment with a silane coupling agent in which an N-phenyl-aminoalkyl group (the alkyl group has the carbon number of 2 to 5) to a silicon atom and organosilazane, in which the molar ratio between the silane coupling agent and the organosilazane being the silane coupling agent: the organosilazane=1:2 to 1:10, and, after the surface treatment step, a solidification step where the silica particle material is precipitated by salt precipitation, and the precipitates are cleaned and dried with water to obtain the solid matter of the silica particle material. By performing the salt precipitation after the surface treatment, the flocculation of the silica particle material subjected to the surface treatment can be effectively suppressed.SELECTED DRAWING: None

Description

  The present invention relates to a silica particle material and a surface treatment method for obtaining a silica particle material by surface-treating silica particles.

  Colloidal silica which is a kind of silica particles is produced by a method of producing water glass as a raw material, a method of producing metal silicon powder as a raw material, a gas phase synthesis method or the like. The method for producing water glass as a raw material produces fine particles by neutralizing the water glass or by precipitating the water glass by ion exchange.

  For example, colloidal silica has a very small particle size of several nanometers to several hundred nanometers. Silica particles having a small particle size are used for various applications. On the other hand, the specific surface area of silica particles having a small particle size is very large. For this reason, silica particles with a small particle diameter have the characteristic of being easily aggregated. Once agglomerated silica particles are difficult to redisperse. For this reason, the silica particle with a small particle size has a problem inferior in handleability.

  Therefore, the applicant has developed a technique capable of suppressing aggregation even with small silica particles (see, for example, Patent Document 1).

JP 2011-213514 A

By the way, phenylamine (-NHPh, -R-NHPh: R is an alkylene such as propylene) has attracted attention as a functional group to be introduced onto the surface of the silica particles. When phenylamine is introduced into the silica particle material by the method of Patent Document 1, it may not be a preferable silica particle material depending on the ratio and amount of introduction.
Furthermore, when the present inventors conducted the above studies, silica particles into which an N-phenyl-aminoalkyl group (Ph—NH—C _n H _2n ) —: n is 2 to 5 and Ph is a phenyl group) are introduced. It has been discovered that a resin composition containing as a filler is superior in adhesion to a copper material as compared with silica particles having other functional groups.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a silica particle material having phenylamine introduced therein and excellent in handleability, and a surface treatment method for obtaining such a silica particle material. To do.

(A) The surface treatment method employed to obtain the silica particle material of the present invention that solves the above-mentioned problems is an N-phenyl-aminoalkyl group (the alkyl group has 2 to 5 carbon atoms) in a liquid medium containing water. ) Has a surface treatment step of surface-treating silica particles with a silane coupling agent bonded to a silicon atom and organosilazane,
The molar ratio of the silane coupling agent to the organosilazane is the silane coupling agent: the organosilazane = 1: 2 to 1:10,
After the surface treatment step, the method includes a solidification step of precipitating the silica particles by salting out by adding a salt compound, washing the precipitate with water and drying to obtain a solid of silica particle material.

  Aggregation of the surface-treated silica particle material can be effectively suppressed by performing salting out after the surface treatment.

  As the salt compound, it is sufficient if the silica particle material is precipitated, but an inorganic salt compound is particularly preferable. The salt compounds are ammonium chloride, ammonium carbonate, ammonium hydrogen carbonate, ammonium sulfate, sodium chloride, sodium nitrate, sodium sulfate, sodium carbonate, sodium phosphate, potassium chloride, potassium nitrate, potassium carbonate, sodium acetate, potassium acetate, ammonium acetate. One or more substances selected from the group consisting of sodium propionate, sodium benzoate, sodium maleate, sodium adipate, sodium citrate, pyridine hydrochloride, triethylamine hydrochloride, tetramethylammonium chloride, and sodium dodecyl sulfate It is preferable that In particular, it is more preferable to select from ammonium salts, carbonates, and ammonium carbonates.

  Any one or more configurations of (B) to (D) described below can be added to the method (A) described above.

(B) The surface treatment step includes
A first treatment step of treating the silica particles with the silane coupling agent;
A second treatment step of treating the silica particles with the organosilazane,
The second processing step is performed after the first processing step.
(C) In the second treatment step, a part of the organosilazane is replaced with a second silane coupling agent having three alkoxy groups and an alkyl group having 1 to 3 carbon atoms,
After the second treatment step, the method further comprises a third treatment step of treating the silica particles with the organosilazane.
(D) The organosilazane is at least one selected from tetramethyldisilazane, hexamethyldisilazane, and pentamethyldisilazane.

(E) The silica particle material that can be produced by the surface treatment method described above includes a functional group represented by the formula (1): —OSiX ¹ X ² X ³ and a formula (2): —OSiY ¹ Y ² Y ^3. Are bonded to the surface of the silica particles and are separated into primary particles even after being dried. (In the above formulas (1) and (2); X ¹ is an N-phenyl-aminoalkyl group (the alkyl group has 2 to 5 carbon atoms); X ² and X ³ are —OSiR ₃ and —OSiY ⁴ Y) from ⁵ Y ⁶ are each independently selected; ^{Y 1} is an ^{R; Y} 2, Y ³ is .Y ⁴ is selected independently from R and -OSiY ⁴ Y ⁵ Y ⁶ is an R; Y ⁵ and Y ⁶ are each independently selected from R and —OSiR ₃ ; R is independently selected from an alkyl group having 1 to 3 carbon atoms, wherein X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ may be bonded to any one of the adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ via —O—.

  The above-mentioned silica particle material (E) can be added with any one or more of the structures (F) to (I) described below.

(F) The abundance ratio of the functional group represented by the formula (1) and the functional group represented by the formula (2) is 1:12 to 1:60. (G) X ¹ is 0.5 to 2.5 per unit surface area (nm ² ) of the silica particle material. (H) R is 1 to 10 per unit surface area (nm ² ) of the silica particle material. (I) The average particle diameter (volume basis, the same applies hereinafter) is 3 to 200 nm.
(J) The silica particle material of the present invention that solves the above problems is used as a filler by being dispersed in a resin material, a particle material having a particle diameter of 3 to 200 nm and mainly composed of silica, and a surface thereof. This is a silica particle material having an introduced N-phenyl-aminoalkyl group (an alkyl group having 2 to 5 carbon atoms) and a functional group. And it has the characteristic that it is excellent in the adhesiveness after hardening | curing in the state which disperse | distributed in the resin material and contacted the member which consists of copper materials as a resin composition.
Here, excellent adhesion means that the peel strength is higher than that of the silica particle material prepared under the same conditions except that the surface has a phenylamino group.
In particular, as the degree of adhesion, A is the peel strength between the cured product of the resin composition and the member adhered to the surface thereof, and the cured product of only the resin material and the member adhered to the surface thereof. When the peel strength between is B, it is preferable that A ÷ B is 0.6 or more.

  According to the silica particle surface treatment method of the present invention, the functional group having N-phenyl-amino and the organosilazane-derived functional group represented by the above formula (2) are bonded to the surface of the silica particle. Can do. Thereafter, aggregation of the surface-treated silica particle material obtained by precipitation by salting out is suppressed. It can be inferred that aggregation can be suppressed because the charge generated in phenylamine can be appropriately controlled by salting out.

  And if the molar ratio of a silane coupling agent and organosilazane is in the range of 1: 2 to 1:10, the functional group represented by the above formula (1) and the functional group represented by the above formula (2). The groups can be present in a balanced manner on the surface of the silica particle material.

The silica particle material of the present invention has X ¹ (N-phenyl-aminoalkyl group) and R (C1-C3 alkyl group) on the surface. Since R, that is, an alkyl group having 1 to 3 carbon atoms has high hydrophobicity, they repel each other. Therefore, the silica particle material of the present invention hardly aggregates due to the repulsive force between alkyl groups having 1 to 3 carbon atoms.

  That is, the silica particle material of the present invention can achieve both the effect derived from the N-phenyl-amino group and the aggregation suppressing effect by allowing the N-phenyl-aminoalkyl group and the alkyl group to coexist.

In addition, the more the R exists on the surface of the silica particle material, the better the aggregation suppressing effect, but the affinity for the resin decreases. The more X ¹ is present on the surface of the silica particle material, the more the effect derived from the N-phenyl-amino group is improved. On the other hand, the number of R is reduced and the aggregation suppressing effect is reduced. Therefore, the existence ratio of the R and X ^1, there is a preferred range. If the abundance ratio of the functional group represented by the formula (1) and the functional group represented by the formula (2) is within the range of 1:12 to 1:60, the resin has excellent affinity and excellent It is possible to achieve both an aggregation suppressing effect. Moreover, X ¹ is as long as 0.5 to 2.5 per unit surface area of the silica particles material (nm ^2), it is possible to achieve both excellent aggregation inhibition effect and excellent affinity to resins.

3 is a graph showing the particle size distribution of the silica particle material of Example 1. 6 is a graph showing a particle size distribution of a silica particle material of Example 6. 6 is a graph showing the particle size distribution of a silica particle material of Example 7. 2 is a graph showing the infrared absorption spectrum of the surface of the silica particle material of Example 1. FIG. It is a graph showing the infrared absorption spectrum of the surface of the silica particle material of Example 6. FIG. It is a graph showing the infrared absorption spectrum of the surface of the silica particle material of Example 7. FIG.

The use of the silica particle material of the present invention is not particularly limited. It can be dispersed in a resin (or resin composition) to form a resin composition, or can be contained in other materials and inserted into gaps formed by the materials. The resin composition can be used for semiconductor encapsulants, underfills, structural materials, and the like. Further, other fillers (micrometer order fibers and particles) can also be dispersed.
In particular, it is preferably used so as to contact a member made of a copper material. For example, it is preferably employed as a filler for a resin composition constituting a substrate material on which wiring (member made of a copper material) is disposed on the surface or inside. In particular, it is desirable to use a filler of a resin composition used for a portion that contacts the wiring. For example, when the wiring is formed on the surface, the resin composition can be used on the surface of the substrate, and when the wiring is formed inside, the resin composition can be used around the wiring disposed inside. It can employ | adopt as the coating | coated material which coat | covers a board | substrate, or can employ | adopt as the contact bonding layer which adhere | attaches a several board | substrate.
When the silica particle material of the present invention is contained in the resin composition, it can be used not only as a filler but also as a part of the filler.
The silica particle material of the present embodiment is a material disclosed in the following (A) or (B).

(A) The silica particle material of the present invention includes a functional group represented by the formula (1): -OSiX ¹ X ² X ³ and a functional group represented by the formula (2): -OSiY ¹ Y ² Y ³ Is a silica particle material bonded to the surface. Hereinafter, the functional group represented by the formula (1) is referred to as a first functional group, and the functional group represented by the formula (2) is referred to as a second functional group.

X ¹ in the first functional group is an N-phenyl-aminoalkyl group (the alkyl group has 2 to 5 carbon atoms, particularly an n-propyl group, in which a nitrogen atom is bonded to the 3-position). Group is preferred). X ² and X ³ are —OSiR ₃ or —OSiY ⁴ Y ⁵ Y ⁶ , respectively. Y ⁴ is R. Y ⁵ and Y ⁶ are each R or —OSiR ₃ .

Y ¹ in the second functional group is R. Y ² and Y ³ are each —OSiR ₃ or —OSiY ⁴ Y ⁵ Y ⁶ .

The more —OSiR ₃ contained in the first functional group and the second functional group, the more R on the surface of the silica particle material. The more R (the alkyl group having 1 to 3 carbon atoms) contained in the first functional group and the second functional group, the less the silica particle material of the present invention aggregates.

Regarding the first functional group, when X ² and X ³ are each —OSiR ₃ , the number of R is minimized. Further, ^{X 2} and ^{X 3} is -OSiY ⁴ Y ⁵ Y ^6, respectively, ^and, if Y 5, ^{Y 6} is -OSiR ₃ respectively, the number of R is maximized.

Regarding the second functional group, when Y ² and Y ³ are each —OSiR ₃ , the number of R is minimized. Further, ^{Y 2} and ^{Y 3} are -OSiY ⁴ Y ⁵ Y ^6, respectively, ^and, if Y 5, ^{Y 6} is -OSiR ₃ respectively, the number of R is maximized.

The number of X ¹ contained in the first functional group, the number of R contained in the first functional group, and the number of R contained in the second functional group are the abundance ratio of R and X ¹ , silica What is necessary is just to set suitably according to the particle size and use of a particulate material.

^{Incidentally, X 2, X 3, Y} 2, Y 3, Y 5, and any of ^{Y 6, X} 2 of the adjacent ^{functionality, X 3, Y 2, Y} 3, Y 5, and any ^{Y 6} You may combine with heel -O-. For example, any one of the first functional group X ² , X ³ , Y ⁵ , and Y ⁶ is the first functional group adjacent to the first functional group X ² , X ³ , Y ⁵ , and It may be bonded to any of Y ⁶ by —O—. Similarly, any of Y ² , Y ³ , Y ⁵ , and Y ⁶ of the second functional group is replaced with Y ² , Y ³ , Y ⁵ , Y ² of the second functional group adjacent to the second functional group. And Y ⁶ may be bonded to each other by —O—. Furthermore, any one of the first functional groups X ² , X ³ , Y ⁵ , and Y ⁶ is the second functional group adjacent to the first functional group, Y ² , Y ³ , Y ⁵ , And Y ⁶ may be bonded to each other by —O—.

In the silica particle material of the present invention, if the abundance ratio of the first functional group to the second functional group is 1:12 to 1:60, X ¹ and R are well balanced on the surface of the silica particle material. Exists. For this reason, the silica particle material in which the abundance ratio of the first functional group to the second functional group is 1:12 to 1:60 is particularly excellent in the affinity for the resin and the aggregation suppressing effect. Further, if X ¹ is 0.5 to 2.5 per unit surface area (nm ² ) of the silica particle material, a sufficient number of first functional groups are bonded to the surface of the silica particle material, and the first There are also a sufficient number of Rs derived from the functional group and the second functional group. Therefore, also in this case, the affinity for the resin and the effect of suppressing the aggregation of the silica particle material are sufficiently exhibited.

In any case, R per unit surface area (nm ² ) of the silica particle material is preferably 0.5 to 10, more preferably 1 to 10. In this case, the balance between the number of X ¹ present on the surface of the silica particle material and the number of R is improved, and both the affinity for the resin and the aggregation suppressing effect of the silica particle material are exhibited in a well-balanced manner.

In the silica particle material of the present invention, it is preferable that almost all of the hydroxyl groups present on the surface of the silica particles are substituted with the first functional group or the second functional group. If the sum of the first functional group and the second functional group is 2.0 or more per unit surface area (nm ² ) of the silica particle material, it is present on the surface of the silica particle in the silica particle material of the present invention. It can be said that almost all of the hydroxyl groups were substituted with the first functional group or the second functional group.

The silica particle material of the present invention has R on the surface. This may be confirmed by an infrared absorption spectrum. Specifically, when the infrared absorption spectrum of the silica particle material of the present invention is measured by a solid diffuse reflection method, there is a maximum absorption of C—H stretching vibration at 2962 ± 2 cm ⁻¹ . For this reason, it can be confirmed by the infrared absorption spectrum whether it is the silica particle material of this invention. However, since the infrared absorption derived from phenylamine is a broad peak, it is often difficult to distinguish, so other methods such as measuring the presence of carbon atoms, carbon atoms, hydrogen atoms, nitrogen atoms, etc. It can be estimated by calculating the composition ratio of the atoms.

  Further, as described above, the silica particle material of the present invention hardly aggregates. Therefore, the silica particle material of the present invention can be applied to a silica particle material having a small particle size. For example, the silica particle material of the present invention can have a particle size of about 3 nm to 5000 nm. It is preferable to apply to a silica particle material having an average particle diameter of 3 to 200 nm.

  In addition, the silica particle material of this invention has isolate | separated even to the primary particle even if it passed through the dry state. Whether or not “the primary particles are separated even after passing through the dry state” can be judged by being dispersible again by ultrasonic treatment. In other words, if it can be easily separated into primary particles even after passing through a dry state, it is “separated into primary particles even after passing through a dry state”. Specifically, the silica particle material of the present invention is substantially dispersed to primary particles by irradiating the silica particle material of the present invention dispersed in methyl ethyl ketone with ultrasonic waves having an oscillation frequency of 39 kHz and an output of 500 W. it can. The ultrasonic irradiation time at this time may be 10 minutes or less. Whether or not the silica particle material of the present invention has been dispersed into primary particles can be confirmed by measuring the particle size distribution. Specifically, if the methyl ethyl ketone dispersion material of the silica particle material is measured with a particle size distribution measuring device such as a microtrack device, the particle size distribution corresponding to the primary particles of the silica particle material is observed, and the particle size distribution of the aggregate is not observed. (For example, the ratio of the aggregate is 5% or less (further 1% or less) on a volume basis), and it can be said that the silica particle material of the present invention is dispersed to primary particles.

  Since the silica particle material of the present invention hardly aggregates, it can be provided as a silica particle material that is not dispersed in a liquid medium such as water or alcohol. In this case, since no liquid medium is brought in, it is preferably used as a filler for a resin material.

  Moreover, since the silica particle material of the present invention hardly aggregates, it can be easily washed with water. For this reason, the silica particle material of this invention is applicable to the silica particle material for electronic components.

The silica particle surface treatment method of the present invention includes a step (surface treatment step) of treating silica particles with a silane coupling agent and organosilazane in a liquid medium containing water. Silane coupling agent, N- phenyl - amino alkyl group (the alkyl group has a carbon number of 2 to 5: i.e. having a functional group that binds X ¹ above to Si) is a silane coupling agent bonded to the silicon atom is there. In particular, N-phenyl-3-aminopropyltrimethoxysilane can be exemplified.

By performing the surface treatment with the silane coupling agent, the hydroxyl group present on the surface of the silica particles is substituted with a functional group derived from the silane coupling agent. The functional group derived from the silane coupling agent is represented by the formula (3); —OSiX ¹ X ⁴ X ⁵ . The functional group represented by the formula (3) is referred to as a third functional group. X ¹ in the third functional group is the same as X ¹ in the functional group represented by the formula (1). X ⁴ and X ⁵ are each an alkoxy group. By surface-treating with organosilazane, the third functional group X ⁴ and X ⁵ are derived from organosilazane —OSiY ¹ Y ² Y ³ (the functional group represented by the formula (2), the second functional group ). When all of the hydroxyl groups present on the surface of the silica particles are not substituted with the third functional group, the hydroxyl groups remaining on the surface of the silica particles are substituted with the second functional group. Therefore, the surface of the surface-treated silica particle material has a functional group represented by the formula (1): —OSiX ¹ X ² X ³ (that is, the first functional group) and a formula (2): —OSiY. ^The functional group represented by ¹ Y ² Y ³ is bonded to the functional group (that is, the second functional group). In addition, since the molar ratio of the silane coupling agent and the organosilazane is silane coupling agent: organosilazane = 1: 2 to 1:10, the first functional group and the second functional group in the obtained silica particle material are used. The abundance ratio with the functional group is theoretically from 1:12 to 1:60.

In the surface treatment step, the silica particles may be simultaneously surface treated with a silane coupling agent and an organosilazane. Alternatively, the silica particles may first be surface treated with a silane coupling agent and then surface treated with organosilazane. Alternatively, the silica particles may be first surface treated with organosilazane, then surface treated with a silane coupling agent, and then surface treated with organosilazane. In any case, the amount of organosilazane may be adjusted so that all the hydroxyl groups present on the surface of the silica particles are not substituted with the second functional group. The hydroxyl groups present on the surface of the silica particles may all be substituted with the third functional group, or only a part may be substituted with the third functional group, and the other part may be substituted with the second functional group. It may be replaced. All of X ⁴ and X ⁵ contained in the third functional group may be substituted with the second functional group.

A part of organosilazane may be replaced with the second silane coupling agent. As the second silane coupling agent, one having three alkoxy groups and one alkyl group can be used. In this case, X ⁴ and X ⁵ contained in the third functional group are substituted with the fourth functional group derived from the second silane coupling agent. The fourth functional group has the formula (4); - represented by OSiY ¹ X ⁶ X ^7. Y ¹ is the same R as ^{Y 1} in the second functional ^{group, X 6,} X ⁷ is an alkoxy group or a hydroxyl group, respectively. X ⁶ and X ⁷ contained in the fourth functional group are substituted with the second functional group derived from organosilazane, or are substituted with another fourth functional group. In this case, the amount of R present on the surface of the silica particle material can be further increased. When a part of the organosilazane is replaced with the second silane coupling agent, it is necessary to surface-treat with the organosilazane again after the surface treatment with the second silane coupling agent. This is because X ⁶ and X ⁷ contained in the fourth functional group are finally substituted with the second functional group derived from organosilazane.

When a part of the organosilazane is replaced with the second silane coupling agent, X ⁴ and X ⁵ contained in the first functional group described above are substituted with the second functional group derived from the organosilazane, Substitution with a fourth functional group derived from the second silane coupling agent. When X ⁴ and X ⁵ are substituted with the fourth functional group, X ⁶ and X ⁷ contained in the fourth functional group are substituted with the second functional group or another fourth functional group. Is replaced by If X ^6, X ⁷ contained in the fourth functional group has been replaced by another fourth functional group, X ^6, X ⁷ contained in the fourth functional groups is substituted with the second functional group The For this reason, the second silane coupling agent is an organosilazane set when the surface treatment is performed only with the first coupling agent and the organosilazane (when the organosilazane is not replaced with the second silane coupling agent). A maximum of 5a / 3 mol can be substituted for the amount (a) mol. The amount of organosilazane required in this case is 8a / 3 mol.

  The alkoxy groups of the silane coupling agent and the second silane coupling agent are not particularly limited, but those having a relatively small carbon number are preferred, and those having 1 to 12 carbon atoms are preferred. Considering the hydrolyzability of the alkoxy group, the alkoxy group is more preferably any one of a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

  Any organosilazane may be used as long as it can replace the hydroxyl group present on the surface of the silica particles and the alkoxy group derived from the silane coupling agent with the second functional group described above. preferable. Specific examples include tetramethyldisilazane, hexamethyldisilazane, pentamethyldisilazane, and the like.

  Examples of the second silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, and hexyltriethoxysilane.

  In the surface treatment step, a polymerization inhibitor may be added in order to suppress polymerization of the silane coupling agent or polymerization of the second silane coupling agent. As the polymerization inhibitor, common ones such as 3,5-dibutyl-4-hydroxytoluene (BHT) and p-methoxyphenol (methoquinone) can be used.

  The silica particle surface treatment method of the present invention may include a solidification step after the surface treatment step. The solidification step is a step of precipitating the silica particle material by adding a salt compound after the surface treatment step. Salting out progresses by adding a salt compound. In this specification, whether or not salting-out is progressing can be determined by whether or not precipitation actually occurs, and salting-out is proceeding only by adding a salt compound to the reaction system. It can be judged as a thing. Further, even when the salt compound is added to a concentration of 2 mmol / L or more (preferably 10 mmol / L or more, more preferably 15 mmol / L or more), the salting out can be handled.

  The obtained precipitate can be washed with water, dried, etc. to obtain a solid of silica particle material. As described above, since a general silica particle material is very likely to aggregate, it is very difficult to disperse the once solidified silica particle material. However, since the silica particle material of the present invention hardly aggregates, it is difficult to aggregate even when solidified, and it is easy to redisperse even if aggregated. In addition, as mentioned above, the silica particle material used for uses, such as an electronic component, can be easily manufactured by wash | cleaning a silica particle material with water. In the washing step, washing is preferably repeated until the electrical conductivity of the silica particle material extraction water (specifically, the water in which the silica particle material is immersed at 121 ° C. for 24 hours) is 50 μS / cm or less.

  Although it does not specifically limit as a salt compound, The method of adding an inorganic salt compound is simple and preferable. Examples of the salt compound include ammonium chloride, ammonium carbonate, ammonium bicarbonate, ammonium sulfate, sodium chloride, sodium nitrate, sodium sulfate, sodium carbonate, sodium phosphate, potassium chloride, potassium nitrate, potassium carbonate, ammonia (water), sodium acetate, Examples include potassium acetate, ammonium acetate, sodium propionate, sodium benzoate, sodium maleate, sodium adipate, sodium citrate, pyridine hydrochloride, triethylamine hydrochloride, tetramethylammonium chloride, and sodium dodecyl sulfate. In particular, it is desirable to employ a substance that volatilizes by heating at about 50 to 300 ° C. Although the salt compound may be used as it is, it is preferably used as a solution (salt compound solution) such as an aqueous solution. The concentration of the salt compound in the salt compound solution is preferably 0.1% by mass or more, and more preferably 0.5% by mass or more. The amount of the salt compound solution can be about 6 to 12 times based on the mass of the silica particle material to be cleaned.

  The treatment with the salt compound solution (contacting, salting out proceeds) can be performed a plurality of times. It is desirable to stir after immersing the silica particle material in the salt compound solution. Further, it can be left in the immersed state for 1 to 24 hours, and further for about 72 hours. When it is allowed to stand, stirring can be continued or not stirred. When processing in a salt compound solution, it can also be heated to room temperature or higher.

  Thereafter, the silica particle material suspended by the treatment is collected by filtration and then washed with water. It is desirable that the water used does not contain ions such as alkali metals (for example, 1 ppm or less on a mass basis). For example, ion exchange water, distilled water, pure water and the like. The silica particle material washed with water can be dispersed and suspended and then filtered, or water can be continuously passed through the filtered silica particle material. The end time of washing with water may be determined by the electric conductivity of the extracted water described above, or may be the time when the alkali metal concentration in the waste water after washing the silica particle material becomes 1 ppm or less, It is good also as the time of the alkali metal concentration of extraction water becoming 5 ppm or less. When washing with water, it can be heated to a room temperature or higher.

  The silica particle material can be dried by a conventional method. For example, heating or leaving under reduced pressure (vacuum).

  As a method of dehydrating the silica particle material other than drying, after adding a water-based organic solvent having a boiling point higher than that of water to the water-containing silica particle material, a mixed material that is soluble in the water-based organic solvent is mixed, A method of removing water can be used. Examples of aqueous organic solvents include propylene glycol monomethyl ether (propylene glycol-1-methyl ether, boiling point of about 119 ° C .; propylene glycol-2-methyl ether, boiling point of about 130 ° C.), butanol (boiling point of 117.7 ° C.), N-methyl- Examples include 2-pyrrolidone (boiling point of about 204 ° C.) and γ-butyrolactone (boiling point of about 204 ° C.).

  The mixed material is an organic compound having a boiling point higher than that of the aqueous organic solvent. Since the boiling point is higher than that of the water-based organic solvent and water, it finally remains together with the silica particle material. The mixed material can be made into a polymer as it is or by reacting. The mixed material can also form a matrix in which the silica particle material is dispersed. The mixed material is a compound that can be dispersed or dissolved in a state where a water-based organic solvent is added to the water-containing silica particle material. The mixed material may be a polymer or a low molecule. The mixed material desirably has an epoxy group, an oxetane group, a hydroxyl group, a blocked isocyanate group, an amino group, a half ester group, an amic group, a carboxy group, and a carbon-carbon double bond group in the chemical structure. These functional groups are functional groups (polymerizable functional groups) that can be bonded to each other by setting suitable reaction conditions, and the molecular weight of the mixed material can be improved. Suitable reaction conditions include simple heating and light irradiation, generation of reactive species such as radicals and ions (anions and cations) by heat and light irradiation, and a reaction initiator that binds between these functional groups. (Polymerization initiator) is added and heating or light irradiation is performed. A compound necessary for the polymerization reaction can be added as a curing agent, or a catalyst for the reaction can be added.

  Preferred examples of the mixed material include a monomer that forms a polymer material by polymerization and a polymer material modified with a polymerizable functional group as described above. For example, a prepolymer such as an epoxy resin, an acrylic resin, or a urethane resin before curing is suitable.

By removing water (and also an aqueous organic solvent), the silica particle material can be mixed or dispersed in the mixed material.
(B) The silica particle material of the present embodiment is used as a filler to be dispersed in a resin material to obtain a resin composition. Although it does not specifically limit as a resin material, An epoxy resin, a phenol resin, a urea resin, a polyimide resin, a urethane resin, and an acrylic resin can be illustrated. The resin material may be either before or after curing.
The silica particle material of this embodiment is composed of a particle material and a functional group introduced on the surface thereof. The particle material has a particle diameter of 3 to 200 nm and is mainly composed of silica. The functional group is a functional group composed of an N-phenyl-aminoalkyl group (the alkyl group has 2 to 5 carbon atoms). A method for introducing a functional group onto the surface of the particle material is not particularly limited, and examples thereof include a method in which the silane coupling agent having the functional group described above is brought into contact with the surface of the particle material.
The resin composition containing the silica particle material of the present embodiment as a filler is excellent in adhesion to a member made of a metal material. The metal material may contain an ordinary metal, for example, pure copper, pure gold, or pure silver, or a metal element such as copper, gold, or silver in an amount of 50% by mass or more based on the total mass. When wiring is provided on a substrate, it is often used in the form of a thin film. Adhesion is measured by measuring peel strength. The peel strength is measured by a method based on JIS K 6854-1 (adhesive-peeling peel strength test method-Part 1: 90 degree peel) described below. The measuring device is a universal material testing machine Model 5582, the test temperature is 23 ° C., the test speed is 50 mm / min, and the peeling width is 10 mm.

  Hereinafter, the silica particle material of the present invention and the surface treatment method of the silica particle of the present invention will be specifically described.

(Test 1: Examination of manufacturing conditions)
Example 1
(1) Preparatory process Colloidal silica (Si-80P: JGC Catalysts & Chemicals Co., Ltd., average particle diameter 80 nm, solid content concentration 40%) as silica particles was diluted with ion-exchanged water so that the solid content concentration was 20%. A slurry was prepared.

(2) First Step 40 parts by mass of isopropanol and 0.3 part by mass of 12N hydrochloric acid were added to 100 parts by mass of slurry in which silica particles were dispersed in water at a concentration of 20% by mass to obtain a dispersion. To this dispersion, 0.3 part by mass of N-phenyl-aminopropyltrimethoxysilane was added and mixed at 40 ° C. for 72 hours (mixed solution). By this step, the hydroxyl group present on the surface of the silica particles was surface treated with a silane coupling agent. At this time, N-phenyl-aminopropyltrimethoxysilane was calculated and added so that a necessary amount of hydroxyl groups (partially) remained without being surface-treated.

(3) Second Step Next, 0.5 part by mass of hexamethyldisilazane was added to the mixed solution. As a salt compound solution, 6 parts by mass of a 5% by mass aqueous ammonium carbonate solution was added and left at 40 ° C. for 72 hours. As the surface treatment progressed, the silica particles that became hydrophobic became unable to exist stably in water and isopropanol, and agglomerated and precipitated. The molar ratio of N-phenyl-aminopropyltrimethoxysilane to hexamethyldisilazane was 2: 5.

(4) Solidification step The total amount of the mixture obtained in the surface treatment step (first and second steps) was filtered off with a filter paper (5A manufactured by Advantech). The filtration residue (solid content) was washed with pure water and then dried at 105 ° C. to obtain a silica particle solid content. The obtained silica particle solid content (corresponding to the silica particle material, the same applies hereinafter) was used as a test sample of this example.

Example 2
A test sample of this example was obtained in the same manner as in Example 1 except that the salt compound solution was changed to a 5% by mass ammonium chloride aqueous solution in the second step.

Example 3
A test sample of this example was obtained in the same manner as in Example 1 except that the salt compound solution was changed to a 5 mass% sodium hydrogen carbonate aqueous solution in the second step.

Example 4
A test sample of this example was obtained in the same manner as in Example 1 except that the salt compound solution was changed to a 5 mass% potassium carbonate aqueous solution in the second step.

Example 5
In the second step, instead of the salt compound solution, 0.2 parts by mass of 12N hydrochloric acid aqueous solution and 0.1 parts by mass of 28% ammonia aqueous solution were added to make ammonium chloride salt in the reaction system. A test sample of this example was obtained by the method.

Example 6
(1) Preparation Step Colloidal silica (Snowtex OL: manufactured by Nissan Chemical Industries, average particle size 50 nm, solid content concentration 20%) was prepared as silica particles.

(2) First Step 40 parts by mass of isopropanol and 2 parts by mass of 28% by mass of ammonia water were added to and mixed with 100 parts by mass of slurry in which silica particles were dispersed in water at a concentration of 20% by mass. 0.5 parts by mass of N-phenyl-aminopropyltrimethoxysilane was added to this dispersion and mixed at 40 ° C. for 72 hours.

(3) Second Step Subsequently, 180 parts by mass of ion-exchanged water and 0.8 parts by mass of hexamethyldisilazane were added. 6 parts by mass of a 5% by mass ammonium carbonate aqueous solution was added as a salt compound aqueous solution, and the mixture was allowed to stand at 40 ° C. for 72 hours. As the surface treatment progressed, the silica particles that became hydrophobic became unable to exist stably in water and isopropanol, and agglomerated and precipitated. The molar ratio of N-phenyl-aminopropyltrimethoxysilane to hexamethyldisilazane was 2: 5.

(4) Solidification step The total amount of the mixture obtained in the surface treatment step was filtered off with a filter paper (5A manufactured by Advantech). The filtration residue (solid content) was washed with pure water and then dried at 105 ° C., and the obtained silica particle solid content was used as a test sample of this example.

-Example 7
(1) Preparation Step Colloidal silica (Snowtex OS: manufactured by Nissan Chemical Industries, average particle size 10 nm, solid content concentration 20%) was prepared as silica particles.

(2) First Step 40 parts by mass of isopropanol and 2 parts by mass of 28% by mass of ammonia water were added to and mixed with 100 parts by mass of slurry in which silica particles were dispersed in water at a concentration of 20% by mass. 3 parts by mass of N-phenyl-aminopropyltrimethoxysilane was added to this dispersion and mixed at 40 ° C. for 72 hours.

(3) Second Step Subsequently, 180 parts by mass of ion-exchanged water and 4 parts by mass of hexamethyldisilazane were added. As a salt compound solution, 6 parts by mass of a 5% by mass aqueous ammonium carbonate solution was added and the mixture was allowed to stand at 40 ° C. for 72 hours. As the surface treatment progressed, the silica particles that became hydrophobic became unable to exist stably in water and isopropanol, and agglomerated and precipitated. The molar ratio of N-phenyl-aminopropyltrimethoxysilane to hexamethyldisilazane was 2: 5.

(4) Solidification step The total amount of the mixture obtained in the surface treatment step was filtered off with a filter paper (5A manufactured by Advantech). The filtration residue (solid content) was washed with pure water and then dried at 105 ° C., and the obtained silica particle solid content was used as a test sample of this example.

Example 8
A test sample of this example was obtained in the same manner as in Example 1 except that the salt compound solution was changed to 5 parts by mass of a 5% by mass triethylamine hydrochloric acid aqueous solution in the second step.

Example 9
A test sample of this example was obtained in the same manner as in Example 1 except that the salt compound solution was changed to 5 parts by mass of a 5% by mass pyridine hydrochloric acid aqueous solution in the second step.

Example 10
A test sample of this example was obtained in the same manner as in Example 1 except that the salt compound solution was changed to 5 parts by mass of a 5% by mass ammonium acetate hydrochloric acid aqueous solution in the second step.

Comparative example 1
The treatment was performed in the same manner as in Example 1 except that the salt compound solution was not added in the second step and 5 parts by mass of 35% hydrochloric acid aqueous solution that was not a salt compound was added instead. Since no aggregation precipitation occurred in the second step, it could not be filtered out in the solidification step, and no solid matter was obtained.

Comparative example 2
The treatment was performed in the same manner as in Example 1 except that hexamethyldisilazane was not added in the second step. Since no aggregation precipitation occurred in the second step, it could not be filtered out in the solidification step, and no solid matter was obtained.

Comparative example 3
After mixing each reagent in the first step, it was processed in the same way except that the second step was performed immediately without mixing at 40 ° C. for 72 hours (the reaction of the silane coupling agent was not completed). It was. Since no aggregation precipitation occurred in the second step, it could not be filtered out in the solidification step, and no solid matter was obtained.

Comparative example 4
Instead of adding a salt compound solution in the second step, instead of adding 5 parts by mass of a 0.1% aqueous solution of nonionic polymer flocculant SS-200 (manufactured by Hymo Co., Ltd.), the same method as in Example 1 was used. Was processed. The obtained silica particle solid content was used as a test sample of this comparative example.

(Cohesiveness evaluation test)
The test samples of Example 1-10 and Comparative Example 4 were evaluated for aggregability in a liquid medium.

  A mixture of 10 g of the silica particle material of Example 1-10 and 15 g of methyl ethyl ketone was stirred to obtain each silica material dispersion. In Comparative Example 4, the same operation was performed, but the particles did not disperse and remained coagulated. The particle size distribution of the silica particle material contained in each of the obtained dispersion samples was measured using a particle size distribution measuring device (Microtrack manufactured by Nikkiso Co., Ltd.). The results of the cohesiveness evaluation test are shown in Table 1, and the particle size distribution is shown in FIG. 1 (Example 1), FIG. 2 (Example 6), and FIG. 3 (Example 7).

  As shown in Table 1 and FIGS. 1-3, it was found that the test samples of the examples were dispersed in the state of primary particles without aggregation. As is clear from FIGS. 1 to 3, it was found that a sharp particle size distribution was shown in the vicinity of the particle size corresponding to the particle size of the colloidal silica used, and the particles were dispersed to primary particles.

  Therefore, by adding the salt compound, the silica particle material could be separated in a state where it could be separated into primary particles.

(Evaluation of functional groups on the surface)
The functional groups present on the surface of the test samples of Examples 1, 6 and 7 were evaluated by FT-IR. Specifically, test samples (silica particle materials) of Examples 1, 6, and 7 were prepared, and the infrared diffusion spectrum of this sample was powder diffusion using FT-IR (manufactured by Thermo Nicolet, FT-IR Avatar). Measured by reflection method. The measurement conditions were a resolution of 4 and a scan count of 64. Graphs representing the results of the maximum absorption measurement test are shown in FIG. 4 (Example 1), FIG. 5 (Example 6), and FIG. 6 (Example 7). Both ^3058cm -1, C-H stretching vibration of aromatic ring 3027cm ^-1, a peak corresponding respectively to the N-H stretching vibration of an amino group to 3413cm ^-1 were observed. For this reason, it turned out that the phenylamino group was introduce | transduced into the test sample of Example 1, 6, and 7 on the surface.

(Test 2: Evaluation of peel strength)
Example A-1
(Create varnish)
A test sample having a volume average particle size of 50 nm (hereinafter referred to as “test sample A-1”, having an N-phenyl-aminopropyl group introduced on the surface) was obtained in the same manner as in Example 1. 150 parts by mass of this test sample was wet mixed with 150 parts by mass of ethyl methyl ketone (MEK) to obtain 300 parts by mass of a dispersion. In 300 parts by mass of this dispersion, 150 parts by mass of MEK, 100 parts by mass of cresol novolac type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd .: YDCN-704), 50 parts of phenol novolac type resin (manufactured by Gunei Chemical Industry Co., Ltd .: PSM-4261) 50 0.1 part by mass of an imidazole-based curing accelerator (manufactured by Shikoku Kasei Kogyo Co., Ltd .: Curesol 2E4MZ) was added and mixed to obtain 600 parts by mass of a varnish as a test sample of this example.

(Prototype sample for peel strength measurement)
The obtained varnish was impregnated into a glass cloth, air dried, and then heated in a hot air circulating oven at 130 ° C. for 10 minutes and further at 150 ° C. for 3 minutes to obtain a semi-cured prepreg. Eight of these prepregs were superposed and further sandwiched between two copper foils, and a vacuum press was performed under the following conditions.

  Using a press apparatus (vacuum press IMC-1AEA type), the molding pressure was about 2 MPa, the molding temperature was raised from 50 ° C. to 170 ° C. at a rate of temperature rise of 5 ° C./min. .

  Further, this was post-cured in a hot air circulating oven at 170 ° C. for 5 hours. The obtained copper-clad laminate was etched (using a ferric chloride solution) leaving a 10 mm wide copper foil.

(Peel strength measurement)
The peel strength of this resin-attached copper foil was peeled by 90 ° under the following conditions, and the peel strength was measured according to JIS K 6854-1. As a result, it was 1.3 kN / m.
A universal material testing machine 5582 type was used as a measuring device, and the measurement was performed at a test temperature of 23 ° C., a test speed of 50 mm / min, and a peeling width of 10 mm. The results are shown in Table 2.

Comparative Example A-1
A test sample (varnish) of this comparative example was prepared in the same manner as in Example A-1 except that the test sample of test sample A-1 was not added, and the peel strength was measured.
Comparative Example A-2
A test sample (varnish) of this comparative example was prepared in the same manner as in Example A-1, except that silica having a phenyl group introduced on the surface (Admatex: YA050C-SP3) was used instead of test sample A-1. The peel strength was measured.

Comparative Example A-3
A test sample (varnish) of this comparative example was prepared in the same manner as in Example A-1, except that silica having a vinyl group introduced on the surface (Admatex: YA050C-SV1) was used instead of test sample A-1. The peel strength was measured.
Comparative Example A-4
A test sample (varnish) of this comparative example was prepared in the same manner as in Example A-1, except that silica having a methacryl group introduced on the surface (Admatex: YA050C-SM1) was used instead of test sample A-1. The peel strength was measured.

As is clear from the table, it was found that the peel strength of the test sample of the example using silica with N-phenyl-aminopropyl group introduced on the surface was higher than that of Comparative Examples A-2 to A-4. .
The test sample of Comparative Example A-1 without silica was the highest in peel strength, but it was found that the test sample of the example showed a high value of 0.81 based on the peel strength value. It is considered that the compatibility of silica with the resin is improved by the reaction of the phenylamino group on the silica surface with the glycidyl group of the epoxy resin.

Claims (13)

The functional group represented by the formula (1): -OSiX ¹ X ² X ³ and the functional group represented by the formula (2): -OSiY ¹ Y ² Y ³ are bonded to the surface of the silica particles, Silica particle material that is separated into primary particles even after being dried. (In the above formulas (1) and (2); X ¹ is an N-phenyl-aminoalkyl group (the alkyl group has 2 to 5 carbon atoms); X ² and X ³ are —OSiR ₃ and —OSiY ⁴ Y) from ⁵ Y ⁶ are each independently selected; ^{Y 1} is an ^{R; Y} 2, Y ³ is .Y ⁴ is selected independently from R and -OSiY ⁴ Y ⁵ Y ⁶ is an R; Y ⁵ and Y ⁶ are each independently selected from R and —OSiR ₃ ; R is independently selected from an alkyl group having 1 to 3 carbon atoms, wherein X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ may be bonded to any one of the adjacent functional groups X ² , X ³ , Y ² , Y ³ , Y ⁵ , and Y ⁶ via —O—.   2. The silica particle material according to claim 1, wherein the abundance ratio between the functional group represented by the formula (1) and the functional group represented by the formula (2) is 1:12 to 1:60. 2. The silica particle material according to claim 1, wherein X ¹ is 0.5 to 2.5 per unit surface area (nm ² ) of the silica particle material. Wherein R is silica particulate material according to any one of claims 1 to 3 wherein the unit surface area of the silica particles material (nm ²⁾ from 0.5 to 10 per.   The silica particle material according to any one of claims 1 to 4, wherein the average particle diameter is 3 to 200 nm. It has a surface treatment process for surface-treating silica particles with a silane coupling agent in which an N-phenyl-aminoalkyl group (alkyl group has 2 to 5 carbon atoms) is bonded to a silicon atom and organosilazane in a liquid medium containing water. ,
The molar ratio of the silane coupling agent to the organosilazane is the silane coupling agent: the organosilazane = 1: 2 to 1:10,
After the surface treatment step, the silica particles are precipitated by salting out by adding a salt compound, and a solidification step of obtaining a solid of silica particle material by washing and drying the precipitate with water. Surface treatment method.   The surface treatment method for silica particles according to claim 6, wherein the salt compound is an inorganic salt compound.   The salt compounds are ammonium chloride, ammonium carbonate, ammonium bicarbonate, ammonium sulfate, sodium chloride, sodium nitrate, sodium sulfate, sodium carbonate, sodium phosphate, potassium chloride, potassium nitrate, potassium carbonate, sodium acetate, potassium acetate, ammonium acetate, propion. One or more substances selected from the group consisting of sodium acid, sodium benzoate, sodium maleate, sodium adipate, sodium citrate, pyridine hydrochloride, triethylamine hydrochloride, tetramethylammonium chloride, and sodium dodecyl sulfate The method for surface treatment of silica particles according to claim 6. The surface treatment step includes
A first treatment step of treating the silica particles with the silane coupling agent;
A second treatment step of treating the silica particles with the organosilazane,
The method for treating a surface of silica particles according to any one of claims 6 to 8, wherein the second treatment step is performed after the first treatment step. In the second treatment step, a part of the organosilazane is replaced with a second silane coupling agent having three alkoxy groups and an alkyl group having 1 to 3 carbon atoms,
The method for treating a surface of silica particles according to claim 9, further comprising a third treatment step of treating the silica particles with the organosilazane after the second treatment step.   The surface treatment method for silica particles according to any one of claims 6 to 10, wherein the organosilazane is at least one selected from tetramethyldisilazane, hexamethyldisilazane, and pentamethyldisilazane. Silica particles having a particle diameter of 3 to 200 nm and having a particle material mainly composed of silica and a functional group composed of an N-phenyl-aminoalkyl group (the alkyl group has 2 to 5 carbon atoms) introduced on the surface thereof Material,
Excellent adhesion after cured in a state where it is dispersed in a resin material and in contact with a member made of a metal material as a resin composition,
A silica particle material used as a filler dispersed in the resin material. The peel strength between the cured product of the resin composition and the member adhered to the surface thereof is A, and the peel strength between the cured material of the resin material only and the member adhered to the surface is B. The silica particle material according to claim 12, wherein A ÷ B is 0.6 or more.

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