JPH02252612A - Silica and production thereof - Google Patents

Abstract

PURPOSE:To effectively obtain silica having high specific surface area and strength even after burning treatment by heat-treating untreated silica resulting from silicate with sol-gel method in specific conditions and burning. CONSTITUTION:Untreated silica obtained from silicate with sol-gel method is heat-treated under 2-16kg/cm<2> pressure at 100-200 deg.C for 2-100 hour in water in a pressure vessel to afford the aimed silica having 30-300m<2>/g specific surface area. In a case of <=950 deg.C said burning temperature, occasionally the aimed silica having sufficient mechanical strength is not obtained. On the other hand, for a burning temperature higher than 1080 deg.C, an effect corresponding to the temperature is not obtained and occasionally a silica having high specific surface area and strength is not obtained, also.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to silica and a method for producing the same, and more specifically, silica that has a high specific surface area and maintains high strength even after firing treatment, For example, semiconductor resin M
The present invention relates to silica that can be suitably used as an AL-agent filler, and a manufacturing method that can efficiently produce silica having such characteristics.

[Prior Art and Problems to be Solved by the Invention] For example, pulverized natural silica or fused silica is used as a resin encapsulant filler for semiconductors.

By the way, in such semiconductor resin fillers, it is desirable to have a high specific surface area and high strength.In other words, if the specific surface area and strength of the resin encapsulant filler are low, surface treatment will be difficult. Silane coupling agent used,
Alternatively, the adhesion between the matrix resin composition such as the epoxy resin composition and the resin sealant filler becomes insufficient, making it impossible to obtain a semiconductor having the performance of stage (2).

However, C in the conventionally used crushed natural silica or fused silica has a problem in that it has a low specific surface area after firing treatment and does not have sufficient strength.

On the other hand, metal catalyst carrier and 1.・A known method for surface treatment of silica gel is heat treatment in the presence of water and alcohol under pressure (Journal of the Chemical Society of Japan, 191).
15. (6), pages 1.016-1023, personal review)
.

However, when the silica obtained by this method is used as a resin encapsulant filler, it can still be used as a silane coupling agent used for surface treatment or as a matrix (helix resin composition) such as an epoxy resin composition. Therefore, the current situation is that silica that has a high specific surface area after firing treatment and still maintains high strength and a method for producing the same have not been developed.

Unissued [JJ was made based on the above circumstances.

The object of the present invention is to provide silica that has a high specific surface area and maintains high strength even after firing treatment and can be suitably used as a filler for a resin encapsulant for semiconductors, and a silica that has such special properties. The object of the present invention is to provide a manufacturing method that can efficiently obtain the following.

[Means for Solving the Problems] In order to solve the above problems, the present inventor has made extensive studies and has developed a specific silica that has a high specific surface area and maintains high strength even after firing treatment. For example, when used as a resin encapsulant filler for semiconductors, it must have sufficient adhesion with a silane coupling agent used for surface treatment or a matrix resin composition such as an epoxy resin composition, and a specific The present invention has been achieved based on the discovery that a specific silica having the above-mentioned advantages can be efficiently and easily produced by subjecting silica to pressure and heat treatment under specific conditions.

The structure of the invention of claim 1 is such that the specific surface area after firing at a temperature of 950 to 1080°C is 30 to 300 rn.
/ g, and the structure of the invention of claim 2 is,
Untreated silica obtained from a silicate ester by the sol-gel method was heated in water in a pressure vessel under a pressure of 2 to 16 kg/cm'' for 2 to 100 hours at a temperature of 1 (+(1 to ZOO'').
7. The method for producing silica according to claim 1, wherein the silica according to claim 1 is heat-treated at C and then fired at a temperature of 950 to 1080°C.
The specific surface area after firing at a temperature of 080℃ is 30-3
00 m"7 g, preferably 33-270 m27 g.

If this specific surface area is extremely low, for example, when used as a resin sealant filler for semiconductors, sufficient adhesion with silane coupling agents used for surface treatment or matrix resin compositions such as epoxy resin compositions will be achieved. There are things you can't get.

Such silica can be obtained, for example, by calcination of silica obtained from a silicate ester by a sol-gel method and then pulverization.

The firing temperature is 950 to 1080°C.

If the firing temperature is less than 950°C, silica with sufficient mechanical strength may not be obtained. On the other hand, 1
Even if it is higher than oso'C, the corresponding effect will not be achieved, and on the contrary, it may not be possible to obtain silica with a high specific surface area and high strength.

The shape of the silica according to claim 1 may be any one of a pulverized shape, a spherical shape, and a rod shape.

In the case of a pulverized type, there is no particular restriction on the particle size distribution, and it can be set as appropriate depending on the application. It is preferable that the diameter is 8 to 15μ1m, and also in the case of one sphere or rod shape, the average diameter,
There are no particular restrictions on the average length, etc., and it can be set appropriately depending on the application, but for example, when spherical silica is used as a resin cutter filler for semiconductors, the average diameter should be 11-50 pΦ. is preferable, and when using the rod-like force as a filler for resin sealing 1 of a semiconductor,
It is preferable that the average length is 1 to 50 pm and the average diameter is 1 to 5 mφ.

When the silica according to claim 1 is used, for example, as a resin encapsulant filler for semiconductors, it can be used as a silane coupling agent used for surface treatment or as a matrix resin composition such as epoxy 4#4 resin composition. It is possible to exhibit excellent adhesion and improve the decrease in mechanical strength caused by poor adhesion.

Further, the silica according to claim 1 can be used as a catalyst carrier, for example.
It can also be suitably used as various fillers.

The silica according to claim 1 having such advantages can be efficiently produced by the method according to claim 2, which will be described in detail below.

In the undeveloped Ijl method, the untreated silica used is obtained from Nisder silicate by a sol-gel method.

Specifically, pulverized silica can be obtained by hydrolyzing a silicate ester to prepare a sol solution, and then subjecting the jelly-like gel obtained by heat treatment of this sol solution to subsequent operations. However, if the sol is emulsified and dispersed in a hydrophobic medium and then subjected to subsequent operations, spherical or rod-shaped silica can be obtained.

As the silicate ester, for example, tetramethoxysilane can be suitably used.

In addition, the hydrophobic short bodies used when obtaining spherical or rod-shaped silica are, for example, l-butanol, t
Examples include ert-butyl alcohol, 1-pentanol, benzene, toluene, and xylene.

In the method of the present invention, the untreated silica is then heat-treated in water in a pressure vessel under a pressure of 2 to 1 [ikg/cm'' and at a temperature of 100 to 200° C. for 2 to 100 hours.

The pressure vessel to be used is not particularly limited as long as it can withstand the pressure treatment and heat treatment under the conditions described above, and for example, an autoclave can be suitably used.

It is desirable that the water introduced into the pressure vessel be of high purity; for example, ultrapure water can be suitably used.

The ratio of the untreated silica to the water in the pressure vessel is usually 50 parts by weight or less of the untreated silica to 50 parts by weight of the water. When the ratio of the untreated silica to 50 parts by weight of the water exceeds 50 parts by weight,
Silica with a high specific surface area may not be obtained after calcination.

In the method of the present invention, the treatment of the untreated silica typically proceeds in water within the pressure vessel under the following conditions.

That is, the pressure inside the pressure vessel is 1 normal.

2-16 kg/cs”, preferably 4-10 kg/cm
It is 2.

If this pressure is less than 2 kg/cm", silica having a high specific surface area may not be obtained after firing. On the other hand, if it exceeds 16 kg/cm", the corresponding effect may not be achieved. , the heating temperature in the method of the present invention is usually 100
-200°C, preferably 170-190°C. If the temperature is lower than 100°C, processing may take a long time,
Silica having a high specific surface M may not be obtained after calcination. on the other hand.

Even if the temperature exceeds 200℃, the corresponding effect will not be achieved.
This is disadvantageous in terms of energy efficiency.

The treatment time is usually 62 to 100 hours, preferably 12 to 100 hours.
It is 18 hours. If this processing time is less than 2 hours,
In some cases, the desired silica having a high specific surface area cannot be obtained after firing due to insufficient treatment. On the other hand, if the time is longer than 100 hours, the corresponding effect may not be achieved, and the production efficiency may even be reduced.

In the method of the present invention, after the above treatment, water and wet silica are usually separated by filtration.

The wet silica obtained by filtration is usually subjected to a calcination treatment after being dried and smoked.

The firing temperature is usually 950-1080°C, preferably 1000-1073°C. If this temperature is lower than 950°C, silica with sufficient mechanical strength may not be obtained. On the other hand, even if the temperature is higher than 1080°C, the corresponding effect may not be achieved, which is disadvantageous in terms of energy efficiency.

For example, an electric furnace can be suitably used for the firing treatment.

The silica thus obtained may be pulverized using a ball mill or the like if it has a pulverized shape, or it can be used as is if it is spherical or rod-shaped.

In any case, the silica obtained by the method of the present invention is
The specific surface area after firing at 1i950-1080℃ is 3
0-300 rn2/g, preferably 33-270
m”1g.

According to the method according to claim 2, by using untreated silica obtained from silicate ester by a sol-gel method for a rice grain, the silica according to claim 1, which has a high specific surface area and high strength even after firing, can be obtained. , it is possible to manufacture it efficiently.

[Example] Next, Examples and Comparative Examples of the present invention will be shown to further specifically explain the present invention.

(Example 1) 4810 g of ultrapure water was put into a 201 flask, and the temperature was set to 1.
In a 5°C water bath, J! ! While stirring, 5074 g of de-1-ramethoxysilane was added dropwise over 3 hours, and the mixture was aged for 1 hour to obtain a hydrolyzed solution (hereinafter referred to as sol solution).

The obtained sol liquid was transferred to a rotary evaporator with a
The mixture was then transferred to a flask, and the flask was attached to an evaporator.

After heating the oil bath to gel the sol solution, it was dried. The temperature of the oil bath at this time was 180°C.

In addition, the moisture content of the obtained dry silica is about 10%,
The specific surface area was 708 s2/g.

Next, 1.2 kg of this dry silica and 1.4 kg of ultrapure water
g and were thoroughly mixed and charged into an autoclave having a capacity of 1990 mJl.

Thereafter, the autoclave was placed in an oil bath heated to 180°C and treated for 18 hours. At this time, the pressure gauge of the autoclave showed 5°Okg/cm2.

This operation was repeated twice to process 2.4 kg of dried perilla.

After the treatment, the ultrapure water and silica were separated, and the obtained silica was fired in an electric furnace at a temperature of 1.000° C. for 4 hours to obtain 1.7 kg of fired silica.

The specific surface area of this calcined silica was 159 m''1 g.

3.7 kg of this calcined silica was placed in an alumina bot mill with a capacity of 7.31 mm, and then alumina balls (25 φ
) About 2.9 sentences were added and grinding was started.

After the grinding was completed, 1.6 kg of silica was obtained.

The specific surface area of the silica obtained was 180 va" 1 g.

Moreover, the particle size distribution of this silica was as follows.

In addition, to measure the specific surface area, a specific surface area automatic measuring machine 21 (manufactured by Micromeritics, "Flowsorb 2300 type") is used, and to measure the particle size distribution, a laser particle size distribution measuring machine 21 (manufactured by Cirrus, Inc.) is used. rclLAs
715 type) was used.

W ■ 1.0 River m 1.5 p-m 2.0 End m 3.0 Seat m 4.0 End m 6.0 Well m 0.5 % 1.5 % 6.1 % 13.1 % 18 .5% 26.5% 8.0 μ, m 33.2
%12.0 xm 4:
1.2%16.0um
54.1 %24.0 lum
72.3 %32.0 well m
85.2%48.0pm
97.7%64.0gm
98.8%96.0 μm
99.3%128.0
h m 99.8%
192.0gm
(Example 2) In Example 1, the firing temperature in the electric furnace was changed to 1.0%.
Example 1 except that the temperature was changed from 00°C to 1,073°C.
It was carried out in the same manner.

The specific surface area of the calcined silica was 33 m2/g, and the specific surface area of the silica obtained by pulverization was 42 m2/g.

Moreover, the particle size distribution of the silica obtained by the pulverization treatment was as follows.

I] 1.0 Extended m 1.5 Extended m 2, Roll m 3.022 m 4.0 4 m 6.0 River m 8, Og, rn 12.0 End m 16.0 μm 24, Lome Lm 32.0 Pot m 48.0 μm 64, Roll m 96.0 End m 128.0 pm 192, Op, m 0.8% 2.2% 7.6% 15.4% 20.9% 28.8% 35 .3 % 44.3 % 53.7 % 67.9 % 80.0 % 95.2 % 97.7 % 99.7 % 100, B % 1110.0 % Soil soaking time - ■ "5" grains n Cloth 1.0 Pot m 1.5 Well m 2.0 Le m 3.0 Tile m 4.0 Tile m 6.0 km 8.0 End m 12.0 River m 16.0 pm 24.0 km 32゜OJLm 48, Op, rn 64.07Lm 96.0 gm 121S, Oμm 192, OpLm 2.1% 3.4% 7.7% 10.0% 10.2% 13.2% 22.6% 44. 1% 65.1% 88.4% 96.4% 98.9% 99.1% 99.3% 99.7% 100.0% 121 culms on soil ILiL concave (Example 3) Silicate ester sol 40 g of wet spherical silica obtained by emulsifying and dispersing the liquid in a hydrophobic medium and 140 g of ultrapure water
g and were thoroughly mixed and charged into an autoclave with a capacity of 200 m.

Thereafter, the autoclave was placed in an oil bath heated to 180°C and treated for 2 hours. At this time, the pressure gauge of the autoclave showed 10 kg/e2.

After the treatment, the ultrapure water and silica are separated, and the obtained wet silica is dried using a rotary evaporator in an oil bath at a temperature of 180°C to obtain dry spherical silica lOg.
I got it.

The specific surface area of this dry spherical silica was 470 m''/g.

Next, this dry spherical silica was fired at a temperature of 1.000°C for 4 hours using an electric furnace to obtain 8 g of fired silica.

The specific surface area of this calcined silica was 70 m2/g.

Moreover, the particle size distribution of the obtained silica was as follows.

(Example 4) The same procedure as in Example 3 was carried out except that the heating time in the autoclave was changed from 2 hours to 15 hours.

The dry spherical silica obtained weighed 10 g, and its specific surface area was 292 2/g.

The amount of silica obtained was 8g, and its specific surface area was 2.
It was 5:11/g.

Furthermore, the particle size distribution of the obtained silica was as follows.

Grain progress blood 1, OPm 1.5 pm 2.0 Km 3.0 pm 4, RO end m 6, OjLm 8.0 #Lm 12.0 uLm 0.0% 0.0% 0.0% 0 .0% 15.1% 48.3% 65.2% 75.2% 1.6. Ou, m 81.
0%24. OJLrv+
89.2%32.0 lumen
94, 4%48.0 gm
99.2%64, OILvn
99.7%g5.0 End m
99,8%128,Q
p-m 99.9%
192, OJLrn 100.
0%1 Jiff-1 6.2- and 4 (Example 5) In Example 3, rod-shaped silica was used instead of spherical silica, and the heating time in the autoclave was changed from 2 hours to 18 hours. was carried out in the same manner as in Example 3 above.

The dry rod-shaped silica obtained weighed 15 g and had a specific surface area of 252 m''/g.

In addition, the obtained silica weighed 13 g, and as a result of SEM observation, it was found to have a length of 501 Lm and a diameter of 10 Lm.
Its specific surface area was 200 m''/g.

(Comparative Example 1) 1.7 kg of silica was obtained in the same manner as in Example 1, except that the heat treatment using an autoclave at °C was not performed.

The specific surface area of the calcined silica was 1.4 m''/g.

Further, the specific surface area of the silica obtained through the pulverization treatment was 3.1 m''/g, and the particle size distribution was as follows.

Grains and capitals 1.0 lm l, 5 end m 2.0 lm 3.0 ro m 4, Ou, m s, 0 lm 8, O#Lnx 12.0 end m 16.0 μm 24 .0 lum 1.0 % 2.6 % 8.5 % 16, l % 21.4 % 29.1 % 35.8 % 44.8 % 53.6 % 66.0 % 32, lLm 76. 9
%48.0 lum 92
．． θ %64.0 μ, m
96,0%96,Op,m
99.2%128.0JLm
99.8%192.0h m
100.0%: Lh and l
L--P21 and m (Comparative Example 2) In Example ie, C, #J, the firing temperature in the air furnace was changed from 1,000°C even though the heat treatment using O-1-crepe was not performed. l, except that the temperature was changed to 07:1℃.
1.7 kg of silica was obtained in the same manner as in Example 1 above.

The specific surface area of the calcined silica was 0.7 m''/g.

Further, the specific surface area of the silica obtained through the pulverization treatment was 2.5 mm''/g, and the particle size distribution was as follows.

alji1 blood 1.11 ILm 1.5 end m 2, roll m 3.0 lum 4, roll m 6.0 lum 8, OILm 12.0 pm 16, OILm 24.0 river m 32, OILm 48, Op, m 64, OJLm 96, OJJ, m 128.0 JLm 192.0 1Lm 1.3% 3.1% 9.5% 16.8% 21.8% 28.6% 35.0% (Comparative Example 3) The above implementation In Example 3, a spherical silica log was obtained in the same manner as in Example 3, except that the heat treatment using an autoclave was not performed.

The specific surface area of the spherical silica used was 7091/g.

In addition, the specific surface area of the obtained spherical silica is 0°6 m2/g
The particle size distribution was as follows.

Grain advance Y cloth 1.0 p-m +, 5 End m 2.0 Well m 3.0 Le m 4, μm 6.0 End m 8, End End m 12.0 End m 1 [i, O gm 24, lo gm 1.3% 2.9% 8.1% 11.7% 11.9% 16.5% 29.1% 53.6% 72.0% 92.6%: f2. OJj, m 98
．． 9%48.0pm
10090%64.0 well
100゜0%96, OjLm
100.0%128, Ou-rn
1.00. O%192.0μ
m 100.0%±A11
Diameter: 1 L Tip (Comparative Example 4) Rod-shaped silica was obtained in the same manner as in Example 5, except that the heat treatment using an autoclave was not performed.

The dry rod-shaped silica obtained weighed 15 g and had a specific surface area of 645 m''/g.

Further, the obtained silica weighed 13 g, and as a result of SEMi test, it was found to have a length of 50 m, a diameter of 10 μm, and a specific surface area of 2.8 m''/g.

(#f value) As is clear from the results of Examples 1 to 5 and Comparative Examples 1 to 4, the silica according to claim 1 obtained by the manufacturing method according to claim 2, It was confirmed that the specific surface area after baking I& was significantly improved.

can do.

[Effects of the Invention] (1) According to statement 1'JI of claim 1, the specific surface area after firing at a particular firing temperature is within a particular range;
For example, when used as a resin encapsulant filler for semiconductors, a silane coupling agent used for surface treatment, or a matrix resin composition such as an epoxy resin composition.
It has the advantages of being able to improve mechanical strength without reducing adhesion to objects, and can also be suitably used as catalyst carriers, various fillers, etc. can provide silica that is useful for

Claims (2)

[Claims] (1) Silica having a specific surface area of 30 to 300 m^2/g after firing at a temperature of 950 to 1080°C. (2) Untreated silica obtained from silicate ester by the sol-gel method was added at 2 to 16 kg/cm in water in a pressure vessel.
Under a pressure of m^2, for 2-100 hours, at a temperature of 100-20
The method for producing silica according to claim 1, wherein the silica is heat-treated at 0°C and then fired at a temperature of 950 to 1080°C.