JPH0517623A - Surface-modified ceramic particle and its production - Google Patents

Abstract

PURPOSE:To provide surface-modified ceramic particles effective in heightening the strengths of a molding and a process for producing the same. CONSTITUTION:Surface-modified ceramic particles prepared from wall material particles having an average particle diameter which is at most 1/8 of that of core material particles and is 5mum or below are fixed on the surfaces of the core material particles comprising ceramic particles treated with a coupling agent; and a process for producing the particles comprising mixing the wall material particles with the core material particles in such a ratio that the weight of the wall material particles is at most 1/5 of that of the core material particles and fixing the wall material particles on the surfaces of the core material particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ceramic particles used as a filler for a molding material composed of, for example, a resin and a filler, and more particularly to surface-modified ceramic particles and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, surface modification of ceramic particles used as a filler has been studied in order to realize high performance such as low stress and high strength of molded products. As the surface modification method, many methods such as topochemical modification, modification by coating, modification by encapsulation under wet condition, modification by mechanical mixing method, modification by high energy, etc. are considered. ing. However, at present, the level of achievement of high performance such as low stress and high strength of the molded product is insufficient by any of the methods.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide surface-modified ceramic particles which are effective for high performance such as stress reduction and strength enhancement of a molded product, and a method for producing the same.

[0004]

The invention relating to surface-modified ceramic particles is such that the average particle size of the core particles is the average particle size on the surface of the core particles made of ceramic particles treated with a coupling agent. ⅛ or less and 5 μm
The following is characterized in that the wall material particles are fixed, the invention relating to the method for producing the surface-modified ceramic particles, the core material particles consisting of the ceramic particles subjected to the coupling agent treatment, the average. A wall material particle having a particle diameter of ⅛ or less of the average particle diameter of the core material particles and 5 μm or less, and the weight of the wall material particles is 1/1 of the weight of the core material particles. It is characterized in that the wall material particles are immobilized on the surface of the core material particles after blending so as to be 5 or less.

The present invention will be described in detail below. The material of the ceramic particles in the present invention is not particularly limited, and examples thereof include silica particles, alumina particles, aluminum nitride particles, silicon nitride particles, silicon carbide particles, and the like.
The particle size is also not particularly limited, but a particle size of 1 to 500 μm, which has been conventionally used, is suitable.

The purpose of the present invention to use the core material particles obtained by treating the ceramic particles with the coupling agent is to improve the adhesive strength when the wall material particles adhere to the surface of the core material particles by the coupling agent treatment. This is because. There is no particular limitation on the coupling agent used in the present invention, but when a coupling agent having a charge property opposite to the surface charge of the wall material particles is used, the wall material particles have a surface of the core material particles by the action of electrostatic attraction. It is preferable because it easily adheres to. Examples of the coupling agent used in the present invention include γ-glycidoxypropyltrimethoxysilane, silane coupling agents such as γ-aminopropyltriethoxysilane and titanate coupling agents, and the like. The addition amount of the coupling agent is not particularly limited, but the core particles 1
An addition amount of 0.1 to 1.5 parts by weight with respect to 00 parts by weight is preferable. The method of treating the coupling agent is not particularly limited, and examples thereof include a dry spray method, a wet method, and an autoclave method.

The material of the wall material particles used in the present invention is not particularly limited, and examples thereof include ceramic particles such as silica particles and alumina particles, resin particles, and metal particles, which can be appropriately selected according to the purpose. Good. In the present invention, the wall material particles are immobilized on the surface of the core material particles, but for that purpose the particle diameter of the wall material particles needs to be significantly smaller than the particle diameter of the core material particles. The particle size is limited to ⅛ or less of the average particle size of the core particles. That is, when it is larger than 1/8, it becomes difficult to fix the wall material particles on the surface of the core material particles. In addition, the smaller the particle size of the wall material is, the more reliably it is immobilized on the surface of the core material particle, so that the average particle size is limited to 5 μm or less.

In the production of the surface-modified ceramic particles of the present invention, if too much wall material particles are blended, excessive wall material particles that are not fixed are formed on the surface of the core material particles, and the excess wall material particles are generated. Has an adverse effect on the performance improvement of the particle-filled composite material, which is the object of the present invention, so it is desirable that the amount of the wall material particles blended with the core material particles should be ⅕ or less of the weight of the core material particles. . On the contrary, when the amount of the wall material particles to the core material particles is extremely small, it becomes difficult to cover the surface of the core material particles with the wall material particles. Therefore, the amount of the wall material particles mixed is at least that of the core material particles. It is preferable to use an amount that is more than the amount that can cover the surface with a single particle layer of wall material particles.

In the present invention, the method for immobilizing the wall material particles on the surface of the core material particles is not particularly limited, and a method by coating, a method by encapsulation under wet conditions, a mechanical mixing method, etc. However, it is preferable to use a mechanical mixing method because the process is simple. This mechanical mixing method includes a dry simple mixing method using an automatic mortar, a dry coating method using a mechanomill, a high-speed air current impact method that uses a strong impact force, and a mechanochemical surface that uses a strong shearing force and thermal energy. Among them, there are a fusion method and the like. Among them, the two methods of the high-speed air current impact method and the mechanochemical surface fusion method are preferable because the wall material particles can be firmly immobilized on the surface of the core material particles.

[0010]

The treatment of the core material particles with the coupling agent according to the present invention serves to improve the adhesive strength when the wall material particles adhere to the surface of the core material particles. The particles are more reliably fixed to the surface of the core material particles, and thus the surface modification of the ceramic particles is more sufficiently performed.

[0011]

【Example】

(Examples 1 to 7 and Comparative Examples 1 to 7) As the ceramic particles for the core material particles, AL-15H manufactured by Showa Denko KK, which is an alumina particle having an average particle diameter of 55 μm, and fused silica having an average particle diameter of 30 μm. SE30 manufactured by Tokuyama Soda Co., Ltd. was used. As the coupling agent, γ-aminopropyltriethoxysilane KBE903 manufactured by Shin-Etsu Chemical Co., Ltd. and γ-glycidoxypropyltrimethoxysilane SH manufactured by Toray Silicone Co., Ltd.
I used 6040 and. These chemical formulas are shown below as Chemical Formula 1 and Chemical Formula 2, respectively.

[0012]

[Chemical 1]

[0013]

[Chemical 2]

Then, the ceramic particles for the core material particles and the coupling agent are weighed according to the combinations and compounding amounts shown in Tables 1 and 2, and the coupling agent treatment is performed by a spray treatment method to obtain the core material. The particles were obtained. However, Comparative Examples 1 to 3
With respect to Nos. 7 and 7, the ceramic particles were used as core particles without the coupling agent treatment.

Next, as wall material particles, MP4951 and MP1400 manufactured by Soken Chemical Industry Co., Ltd., which are fine particles of acrylic resin, TTO-55C manufactured by Ishihara Sangyo Co., Ltd., which is a titanium oxide fine particle, and UA manufactured by Showa Denko KK, which is an alumina fine particle. -5105, G-17H manufactured by Dowa Mining Co., Ltd., which is a silver particle, and EP-AD manufactured by Toray Co., Ltd., which is a powder of a cured epoxy resin, were used.

The above-mentioned core material particles and wall material particles are blended according to the combinations and blending amounts shown in Tables 1 and 2, and Mechanofusion System (registered trademark) manufactured by Hosokawa Micron Co., Ltd.
Machine was used to perform mechanical mixing by the mechanochemical surface fusion method at 1000 rpm for 5 minutes to obtain surface-modified ceramic particles having wall material particles fixed on the surface of core material particles.
(Note that the compounding amounts shown in Tables 1 and 2 are all parts by weight.) The obtained surface-modified ceramic particles are observed with a scanning electron microscope (SEM) to fix the wall material particles on the surface of the core material particles. By observing the situation, the degree of modification of the obtained surface-modified ceramic particles is defined as 100% when the surface is completely covered and 0% when the surface is not covered at all. The evaluation was performed and the results are shown in Tables 1 and 2.

Next, the surface-modified ceramic particles obtained above were compounded in accordance with the compounding amounts shown in Tables 1 and 2 to obtain molding materials. At that time, the epoxy resin is ESCN-195 manufactured by Sumitomo Chemical Co., Ltd., the curing agent is Tamanol 752 manufactured by Arakawa Chemical Co., which is a phenol novolac resin, and the curing accelerator is triphenylphosphine manufactured by Kitako Chemical Co., Ltd. These blends were kneaded with a mixing roll for 10 minutes and then pulverized to obtain a molding material. Transfer molding was performed using the molding material obtained at a molding temperature of 170 ° C.
After-curing was performed at ℃ for 4 hours to obtain a molded product. The linear expansion coefficient and bending strength of the obtained molded product were measured, and the results are shown in Tables 1 and 2. The coefficient of linear expansion is TMA
The flexural strength was measured according to JIS standard K-6911 by the compression method using an expansion amount in the range of 50 to 100 ° C.

[0018]

[Table 1]

[0019]

[Table 2]

In Tables 1 and 2, comparison between Example 1 and Comparative Example 1, comparison between Example 5 and Comparative Example 2 and Example 7
From the comparison between Comparative Example 7 and Comparative Example 7, Examples 1, 5 and 7 using the core material particles treated with the coupling agent, Comparative Example 1 using the core material particles not treated with the coupling agent, 2,
7 indicates that the reforming rate and the performance of the molded product are excellent. The effectiveness of this coupling agent treatment can be said from the comparison of the modification ratios of Example 6 using silver fine particles and Comparative example 3.

Further, comparing Example 1 and Example 2, Example 2 using wall material particles having an average particle size of 1 μm
Shows that the modification ratio and the performance of the particle-filled composite material are slightly lower than those of Example 1 in which the wall material particles having an average particle diameter of 0.15 μm are used. It shows that the performance of (1) tends to decrease. The material of the wall material particles of Comparative Example 4 is different from those of Examples 1 and 2, and
Although it cannot be directly compared with, it can be seen that in Comparative Example 4 in which the wall material particles having an average particle size of 7 μm are used, the modification rate is 0%, and it is not desirable that the particle size of the wall material particles exceeds 5 μm. .

Further, Example 3 is an example in which the content of the wall material particles is set to 5 parts by weight, which is larger than the 2 parts by weight of Example 1, and is affected by the increase in the content of the wall material particles as compared with Example 1. The modification rate and the performance of the molded product are slightly degraded. On the other hand, in Comparative Examples 5 and 6 in which the blending amount of the wall material particles is 1/5 or more (by weight) of the core material particles, compared with Examples 4 and 5 in which only the blending amount of the wall material particles is different. The reforming rate and the performance of the molded product are reduced, and particularly the reforming rate is significantly reduced.

[0023]

When the surface-modified ceramic particles of the present invention are used as a molding material, the linear expansion coefficient of the resulting molded article is lowered,
That is, it is possible to reduce stress or improve bending strength, that is, increase strength. According to the method for producing surface-modified ceramic particles of the present invention, surface-modified ceramic particles useful when used as a molding material can be produced.

Claims (2)

[Claims] 1. The surface of core particles made of ceramic particles treated with a coupling agent has an average particle diameter of 1/8 or less of the average particle diameter of the core particles and 5 μm or less. Surface-modified ceramic particles, wherein certain wall material particles are fixed. 2. Core particles made of ceramic particles treated with a coupling agent, and a wall having an average particle diameter of ⅛ or less of the average particle diameter of the core particles and 5 μm or less. Material particles are mixed so that the weight of the wall material particles is ⅕ or less of the weight of the core material particles, and then the wall material particles are fixed on the surface of the core material particles. A method for producing surface-modified ceramic particles, comprising: