JPH061605A - Silica fine powder, production thereof and resin composition containing silica fine powder - Google Patents

Abstract

PURPOSE:To improve dispersibility to a resin by mixing plural SiO2 fine powder having a specific average particle diameter in a prescribed ratio by the use of a ball mill, vibration mill, a planetary pulverizer or a jet mill. CONSTITUTION:A SiO2 fine powder having 0.1-3mum average particle diameter, 2-50m<2>/g specific surface area is fed into the ball mill, vibration mill, planetary pulverizer or jet mill having a prescribed capacity and furthermore 1-30wt.% SiO2 fine powder having <=0.1mum average particle diameter and 50-400m<2>/g specific surface area is added to mix for a prescribed time. The obtained SiO2 fine powder mixture has <=0.4 flowability index, >=10 adhesivity index and >=0.6g/cm<2> final tapping density and a resin composition obtained by blending the SiO2 fine powder mixture with an epoxy resin, silicone resin or the like has low viscosity, has excellently dispersed SiO2 fine powder and exhibits improved strength and expansion coefficient.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a silica fine powder which can be mixed in a resin such as an epoxy resin with good dispersibility and can be made into a low viscosity, a method for producing the same, and a silica fine powder containing the same. Resin composition.

[0002]

2. Description of the Related Art In recent years,
Fine silica obtained by classification of silica powder and fine spherical silica obtained by the sol-gel method or the method by direct oxidation of metal silicon are used in a wide range of applications such as casting materials, semiconductor encapsulating materials, and coatings. Has become.

However, such fine silica powder, especially fine spherical silica powder obtained by the method of direct oxidation of metallic silicon, has a strong cohesive force and therefore has a dispersibility when used as a filler for a liquid resin composition. Very bad,
It tends to exist as aggregates in the resin. In addition, when this composition is applied using a dispenser, there is a problem that nozzle clogging occurs.

Therefore, in order to improve the dispersibility of this kind of fine silica powder, there has been proposed a method of mixing dry ultrafine powder silica represented by Aerosil. However, when dry ultrafine silica is mixed with a high-speed stirring device such as a Henschel mixer, the dispersibility of the fine silica can be greatly improved, but the ultrafine silica is mixed. However, the resin composition containing this silica had a markedly increased viscosity and was not suitable for practical use.

The present invention has been made in view of the above circumstances, and a fine silica powder having good dispersibility without secondary aggregation, a method for producing the same, and a low viscosity and dispersibility by using the fine silica powder. It is an object of the present invention to provide a good resin composition of

[0006]

Means and Actions for Solving the Problems As a result of earnest studies for achieving the above object, the present inventor has found that fine powder silica having an average particle size of 0.1 to 3 μm has an average particle size of less than 0.1 μm. By mixing 1 to 30% by weight of finely divided silica, and at this time using a ball mill, a vibration mill, a planetary crusher, or a jet mill, the fluidity index is 0.4 or less and the adhesion index is A silica fine powder having a final tap density of 10 or more and a final tap density of 0.6 g / cm ³ or more is obtained,
The present inventors have found that a resin composition having a low viscosity and good dispersibility can be obtained by compounding and filling a resin with this fine silica powder, and have accomplished the present invention.

Therefore, according to the present invention, (1) the average particle size is 0.1
Fine silica powder having an average particle size of less than 0.1 μm is mixed with fine powder silica having a particle size of ˜3 μm in an amount of 0.
4 or less, an adhesion index of 10 or more, and a final tap density of 0.
Fine silica powder characterized by being 6 g / cm ³ or more, (2) 1 to 30% by weight of fine powder silica having an average particle diameter of 0.1 to 3 μm and fine powder silica having an average particle diameter of less than 0.1 μm.
Addition and mixing using a ball mill, vibration mill, planetary crusher or jet mill, and (3) 5 to 5 of the above silica fine powder.
A resin composition containing 90% by weight is provided.

The present invention will be described in more detail below. As the fine powder silica having an average particle size of 0.1 to 3 μm used in the present invention, fine silica powder produced by a sol-gel method using alkoxysilane as a raw material, or Fine spherical silica powder obtained by direct oxidation of metallic silicon
0-255602), and has a specific surface area of 2 to
A material having an average particle diameter of 0.2 to ² μm and a specific surface area of ² to 15 m ² can be used, although those having a particle size of about 50 m ² / g can be used.
/ G can be effectively used, and these are the powders most easily aggregated.

On the other hand, the fine powder silica having an average particle diameter of less than 0.1 μm, which is added to the fine powder silica having an average particle diameter of 0.1 to 3 μm in order to improve dispersibility, includes dry fine powder silica and wet silica. It is preferably used, specifically, dry fine powder silica having a specific surface area of 50 to 400 m ² / g and an average particle diameter of 8 to 40 m, such as Aerosil OX50, Aerosil 130, Aerosil 200, Aerosil 300, Aerosil A972, Tokusil U, and the like. Wet silica having a specific surface area of 150 to 250 m ² / g and an average particle size of 15 to 80 mμ such as Toxyl N is exemplified. Of these, dry fine powder silica of Aerosil 200, Aerosil 300, and Aerosil A972 is particularly preferable.

The fine silica powder of the present invention has 1 to 30% by weight, preferably 5 to 1% by weight of fine silica powder having an average particle diameter of less than 0.1 μm in addition to the above fine silica powder having an average particle diameter of 0.1 to 3 μm.
5% by weight is mixed, the fluidity index is 0.4 or less, the adhesion index is 10 or more, preferably 13 or more, and the final tap density is 0.6 g / cm ³ or more to improve the dispersibility and to form a liquid resin. When dispersed, it has a low viscosity, but when the mixing ratio is less than 1% by weight, the fluidity index is 0.5 to 0.7, the adhesion index is less than 10, and the powder lacks dispersibility. Become. On the other hand, when the mixing ratio exceeds 30% by weight, the amount of finely divided silica having a particle size of less than 0.1 μm becomes excessively large, resulting in powders having completely different particle sizes.

Here, the cohesiveness, adhesion, or fluidity of the powders can be measured by using a tapping measuring device (Tap Denser KYT-3000, manufactured by Seishin Enterprise Co., Ltd.). The index and the adhesion index can be obtained from the following formulas by plotting the number of tappings (N) and the number of tappings / Casavel degree (N / C) on the X and Y axes. (N / C) = (1 / a) N + 1 / ab (fluidity index; a, adhesion index; 1 / b)

As a method for mixing the finely divided silica particles, those which are mixed while applying an impact force (ball mill,
Vibration mill, planetary crusher, jet mill) are suitable,
By using such a mixing device, the fluidity index,
It is possible to reliably obtain fine silica powder having an adhesion index and a final tap density. The mixing conditions are not particularly limited, and it is possible to employ the conditions under which both the fine powder silicas can be uniformly mixed. At the time of this mixing, a silane coupling agent or the like may be mixed to simultaneously carry out the surface treatment of the fine powder silica.

The silica fine powder thus obtained is
The silica fine powder has no secondary agglomerates and has good dispersibility. The silica fine powder is contained in a conventionally known liquid or solid resin composition such as an epoxy resin, a silicone resin or a polyimide resin in an amount of 5 to 90% by weight, preferably By blending 30 to 85% by weight, various properties such as strength and expansion coefficient can be improved.

Further, by using the above silica fine powder,
A filler and a resin composition thereof, which can be used for casting materials, semiconductor encapsulating materials, paints, photoresist ink materials, etc., which could not be used because of its high viscosity, have excellent dispersibility and can be reduced in viscosity. You can get things.

Here, the epoxy resin is not particularly limited as long as it has one or more, especially two or more epoxy groups in one molecule, and examples thereof include bisphenol type epoxy resin, alicyclic epoxy resin, and phenol. Novolac type epoxy resin, cresol novolac type epoxy resin,
Examples include triphenol methane type epoxy resin, naphthalene type epoxy resin, aralkyl type epoxy resin, etc.
You may use these individually or in combination of 2 or more types.

Typical examples of the curing agent for the epoxy resin include compounds having two or more phenolic hydroxyl groups in one molecule such as phenol resin, amine compounds and acid anhydride compounds. Further, a phosphine derivative, an imidazole derivative or the like may be added to accelerate the reaction.

On the other hand, as the silicone resin, a composition comprising a silanol group-containing silicone resin, a silicone oil having both silanol groups at both ends and a curing agent therefor, a vinyl group-containing silicone resin or a silicone oil and a hydrosilyl group-containing silicone are used. A typical example is a composition comprising a compound.

The polyimide resin is obtained by heating and reacting tetracarboxylic dianhydride and aromatic diamine. Also, as the polyimide resin, N
It is also possible to use one dissolved in a polar solvent such as -methyl-2-pyrrolidone.

In addition to the silica obtained in the present invention as a filler for the above-mentioned epoxy resin, silicone resin and polyimide resin, fused silica, crystalline silica, alumina, talc, mica, silicon nitride, boron nitride, etc. You may use together.

Further, various additives may be added to the resin composition of the present invention, if necessary. For example, waxes, colorants such as carbon black, flame retardants, surface treatment agents such as silane coupling agents, antioxidants, and other additives may be added.

Further, the resin composition of the present invention can be produced by uniformly stirring and mixing predetermined amounts of the above-mentioned components and kneading with a kneader or roll.

[0022]

The silica fine powder of the present invention has good dispersibility without secondary aggregation, and the production method of the present invention makes it possible to easily and surely obtain such silica fine powder. The resin composition containing the fine silica powder has a low viscosity and good dispersibility of the fine silica powder.

[0023]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Examples and Comparative Examples 50 alumina balls having a diameter of 30 mm were placed in a ball mill having an internal volume of 100 liters.
As a finely powdered silica of 0.1 to 3 μm containing kg
SO-25R (spherical, average particle size 0.5 μm, specific surface area 8 m ² / g) manufactured by Admatechs Co., Ltd. is used, and each of AEROSIL manufactured by Nippon Aerosil Co., Ltd. Add 10 kg each of the grades mixed at the ratio shown in Table 1, and
Mixing was performed for 0 minutes to prepare samples A, B, and C.

For comparison, the same mixture was stirred for 5 minutes in a Henschel mixer to obtain samples D and E, and sample F containing only fine powder silica having an average particle size of 0.1 to 3 μm is shown in Table 1 below. It was prepared at the ratio shown.

The specific surface area (BET
Method) and laser diffraction particle size analyzer (Granulom)
Table 1 shows the average particle size by the method of ETER CILAS.

[0027]

[Table 1]

Next, the fluidity index, the adhesion index, the bulk density, and the final tap density of each of the samples A to F were measured.
In this case, the fluidity index, the adhesion index, the tap density, and the bulk density were measured using Tap Denser KYT-3000 [manufactured by Seishin Enterprise Co., Ltd.]. The results are shown in Table 2.

From the results of Table 2, it was confirmed that the fluidity index of all those containing fine powder silica of less than 0.1 μm was 0.4 or less, and the fluidity of the granules was good. It was

[0030]

[Table 2]

Further, each of the above samples was mixed with a liquid epoxy resin, and its viscosity and dispersibility were evaluated. The results are shown in Table 3. The mixing conditions were as follows: 250 parts by weight of liquid epoxy resin (Epicoat 828 Yuka Shell Co., Ltd.), 10 parts by weight of imidazole catalyst, and 150 parts by weight of each sample. These were stirred and mixed at 80 ° C., and then at the same temperature. The viscosity after standing for 30 minutes was measured with a B-type viscometer, and at the same time, the dispersibility was visually confirmed.

[0032]

[Table 3]

From the results shown in Table 3, it was confirmed that Samples A, B and C were resins having low viscosity and good dispersibility. On the other hand, Samples D and E showed good dispersibility, but the reduction in viscosity was not achieved.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koji Futatsumori Koji Futami, Hitomi, Matsuida-cho, Usui-gun, Gunma Prefecture 10 Shin-Etsu Chemical Co., Ltd. Silicone Electronic Materials Research Laboratory (72) Tatsuro Hirano Shiba Park, Minato-ku, Tokyo 2-9-5 Tatsumoriuchi Co., Ltd.

Claims (3)

[Claims] 1. A fine powder silica having an average particle diameter of 0.1 to 3 μm is mixed with 1 to 30% by weight of fine powder silica having an average particle diameter of less than 0.1 μm, and a fluidity index of 0.4 or less and an adhesive force index. 1
A fine silica powder having a final tap density of 0 or more and a final tap density of 0.6 g / cm ³ or more. 2. A ball mill, a vibration mill, a planetary crusher or a jet mill is prepared by adding 1 to 30% by weight of fine powder silica having an average particle size of less than 0.1 μm to fine powder silica having an average particle size of 0.1 to 3 μm. The mixture is used and mixed.
A method for producing the fine silica powder described above. 3. The silica fine powder according to claim 1 is contained in an amount of 5 to 90.
A resin composition, characterized in that the resin composition is contained in a weight percentage.