JPH02225302A - Powder manufacturing method - Google Patents

Abstract

PURPOSE:To obtain powder of glass or ceramic composition containing a slight foreign matter without requiring expensive pulverizing device, etc., by co- hydrolyzing metallic alkoxide with polymerizable unsaturated group-containing alkoxysilane in water medium of fluidized state. CONSTITUTION:A metallic alkoxide (e.g. tetramethoxysilane) is cohydrolyzed with a silane compound (e.g. gamma-methacryloyloxlpropyl trimethoxysilane) having at least one alkoxide group and polymerizable unsaturated bonding in water medium (preferably deionized water) and resultant wet gel powder is dried at 50-200 deg.C to obtain hydrogel powder having polymerizable unsaturated bonding. Mixing ratio of the silane compound and metallic alkoxide is 5:95-85:15, preferably 10:90-60:40, in weight ratio. Weight ratio of total of the raw material to water is preferably 15:55-50:50 and reaction temperature is preferably 20-90 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing glass or ceramic composition powder by hydrolysis of metal alkoxides.

(Prior art) Glass and ceramics are usually manufactured by heating raw materials to form a molten or sintered product, and then cooling it. However, as a manufacturing method that does not involve melting, metal alkoxide A method of hydrolysis has been proposed. This method uses the general formula M'' (OR)n (M': metal element, R:
It hydrolyzes a metal alkoxide represented by an alkyl group), but since the alkoxide group OR- in the molecule is a strong Lewis base, it is easily hydrolyzed (OR-
+Ht O→OH-+ROH)・, through the condensation of this hydrolyzate, it passes through an aqueous sol (a state in which very fine colloidal particles are suspended in water), a jelly-like or agar-like gel (wet gel) This is a method to obtain glass or ceramics by sintering it. Compared to normal melting methods, this method not only saves energy because glass and ceramics can be obtained at a lower temperature than the conventional melting method. It may be possible to produce glasses and ceramics with new compositions that are difficult to produce using the fusion method due to their high oxidation.

- It is easy to highly purify raw materials by distillation, etc., and this hydrolysis method is a liquid reaction, making it possible to produce glasses and ceramics with excellent homogeneity.

Because of these advantages, research and development is becoming more active as a method for developing new materials.

Currently, glass and ceramics in shapes such as blocks, plates, fibers, and thin films are produced using this method, but powder-like products cannot be obtained by the above method alone; A method of mechanically crushing glass or ceramics (mechanical crushing method), a method of spraying a wet gel and drying it while it is in the spray state (spray drying method), and a method of crushing an aqueous sol with toluene or paraffin. It is produced by a method of dispersing it in a liquid that is substantially immiscible with water, such as oil or spindle oil, and gelling it in this state (oil drop method).

(Problems to be solved by the invention) However, among the above methods, mechanical crushing method, oil drop method, etc.
There is a problem in that there is contamination of impurities from equipment, media, etc., which tends to impair homogeneity, which is one of the characteristics of the metal alkoxide hydrolysis method.

In addition, all three methods have low production efficiency in terms of crushing, cleaning, energy consumption, etc., which increases manufacturing costs and makes them uneconomical.

Spray drying methods, oil drop methods, etc. require large-capacity equipment and require a large investment in equipment.

It has various problems such as.

(Means for Solving the Problems) In view of the above circumstances, the present inventors have conducted intensive studies on a method for producing metal oxide powder by metal alkoxide hydrolysis that does not have the above-mentioned drawbacks. We discovered that a metal oxide composition can be obtained in powder form by co-condensing a metal alkoxide with a specific silane compound under specific conditions,
We have arrived at the present invention.

That is, the gist of the present invention is to provide a metal oxide powder that co-hydrolyzes a metal alkoxide and a silane compound having one or more alkoxide groups and a polymerizable unsaturated bond in a fluidized aqueous medium. It's in the way the body is manufactured.

In the present invention, an aqueous medium in a fluid state means that the aqueous medium is in a turbulent state, that is, it flows while various parts of the fluid mix irregularly, and even in a steady flow, the velocity, pressure, etc. at one point are around the average value. This refers to a fluid state that constantly fluctuates irregularly, and this fluid state can be controlled using any of the various commonly used stirring methods, such as stirring using stirring blades or rotors, or stirring using jets. You can also do this.

As the metal alkoxide that can be used in the present invention, any metal alkoxide can be used as long as it is a metal alkoxide that is normally subjected to hydrolysis to produce glasses and ceramics. Specific examples of metals include %Li,
Mg, Ca.

Sr, Ba, AI, Ga, In, Si, Ge.

Sn, Pb, As, Sb, S, Te, Y, La.

Ti, Zr, Hf, V, Nb, Ta, W, Mn.

Examples include Fe, Go, Ni, Pd, Cu, and Zn.

The alkoxide component of metal alkoxide has a carbon number of 1
Alkoxides from monohydric or polyhydric alcohols of 0 or less can be used, and alkoxides of alcohols having 5 or less carbon atoms are preferred. Metal alkoxides refer to those in which all the metal bonds are bonded to alkoxides, and among the above metal alkoxides, preferred are lithium methoxide, magnesium dimethoxide, aluminum trit-butoxide, aluminum trimybutoxide, Aluminum trimypropoxide, calcium moropropoxide, tetraethyl titanate, tetramypropyl titanate, tetramybutyltitanate, iron trismethoxide, iron trisethoxide, copper di-i-propoxide, gallium trisethoxide, yttriumium titanate Propoxide, tetraethyl zirconate, tetra n-propyl zirconate, tetra n-
Butyl zirconate, indium tris-propoxide, tin tetra-propoxide, antimony di-n-butoxide, barium dimethoxide, lanthanum tris-propoxide, hafnium tetra-propoxide, hafnium tetra-bentoxide, tetraethoxy germanium , tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetra n-butoxysilane, and the like.

As the silane compound having a polymerizable unsaturated bond used in the present invention, any compound having one or more alkoxide group per molecule and having a polymerizable unsaturated bond can be used. However, those with 2 or 3 gI alkoxide groups in one molecule,
It is preferable because it has good cohydrolyzability with metal alkoxides.

Here, as the polymerizable unsaturated bond, an ethylenically unsaturated bond including a vinyl group can be exemplified, and the silica 24
A specific example of 8 compounds is γ-methacryloyloxybrobyltrimethoxysilane (CHa=c(CH,)Co□(C
Hi)-S i (OCR-)-), γ-methacryloyloxybrobyldimethoxymethylsilane (CH2=C(
CH-)CO-(CHa)-5iCHs(Q CH5)
z), vinyltris(β-methoxyethoxy)silane (
CH2”CHS i (OCH* CHxOCH,)
, ), vinyltriethoxysilane (CH2”CHS i
(OC2H-)-), γ-glycidoxy3.3-
Dimedyl-1-propenyltrimethoxysilane (OCR
, ), ), vinyltrimethoxysilane (CH.

=CH5i (OCH=)s), γ-methacryloyloxybrobiltris(β-methoxyethoxy)silane C
CH2C(CH-)CO2(CH-)-S i (O
Examples include C-H, OCH, ), ), and among these, γ-methacryloyloxybrobyltrimethoxysilane is preferred because it has a large granulation effect in an aqueous system.

In the present invention, the silane compound and metal alkoxide are co-hydrolyzed, and this hydrolysis can be promoted using an acid or alkali catalyst. The acid is hydrochloric acid,
Any substance that acts as an acid can be used, such as inorganic acids such as sulfuric acid and nitric acid, and organic acids such as formic acid and acetic acid. Examples of the alkali include ammonium hydroxide, aqueous ammonia, sodium hydroxide, potassium hydroxide, and the like.

In view of powder forming properties, filterability during recovery of the produced powder, etc., the preferred blending ratio of the silane compound having a polymerizable unsaturated bond used in the present invention and the metal alkoxide is 5:95 to 5:95 by weight. 85:15 and 10:90
More preferably, the ratio is from 60:40.

When the silane compound specified in the present invention and a metal alkoxide are co-hydrolyzed in a fluidized aqueous medium as in the present invention, a powder of a co-condensate of the metal oxide and a silane compound having a polymerizable unsaturated group is obtained. The average particle size of this powder is affected by the fluidity of the aqueous medium, catalyst concentration, reaction conditions such as co-condensation temperature, etc., but is also affected by the blending ratio of the silane compound and metal alkoxide. The larger the amount of the silane compound added, the larger the average particle size of the powder obtained.

As the aqueous medium used in the present invention, deionized water is preferably used, and the amount thereof is at least the amount required for the hydrolysis stoichiometry in the hydrolysis process of the metal alkoxide and the alkoxysilane, and It may be selected as appropriate within the range as long as the condition can be maintained, but it is preferable that the weight ratio of the total amount of metal alkoxide and silane compound to water is 9:95 to 70:30, More preferably, the ratio is 1.5:85 to 50:50.

When an acid is used as a catalyst to promote cohydrolysis, it is preferably blended so that the pH of the reaction system is about 2-9.

The reaction temperature varies depending on the activity of the metal alkoxide used, but is generally 10-100°C, preferably 20-90°C.
Although the reaction time at 0° C. varies depending on the activity of the metal alkoxide used, the reaction temperature, etc., it is generally carried out in the range of 30 minutes to about 48 hours.

The wet gel powder obtained by cohydrolysis is
By drying at a temperature of 300°C, preferably about 50-200°C, no agglomeration occurs.

A dry hydrogel powder having polymerizable unsaturated bonds can be obtained.

This powder can be copolymerized with an organic monomer using the polymerizable unsaturated bonds it contains to form an organic/inorganic composite material, or it can be fired at an appropriate temperature to form a glass or ceramic powder.

In the case of firing, it is preferable to perform the firing at 400-1200''C for 14 hours or more, and this firing will not cause sintering between particles of the powder.

(Example) The present invention will be further explained below using Examples.

In addition, in the examples, the recovery performance was evaluated using filter paper (
QUALITATIVE made by Toyo Roshi ■: 2) is carried out by vacuum filtration with an aspirator, and the separation of water and product is completed within 1 hour. Alternatively, those that became block-shaped and could not be obtained as powder were designated as X.

Example 1 A cooling pipe, a stirring rod, and a thermocouple for detecting internal temperature were set.
In a 0m4240 flask, 20 g of tetramethoxysilane Si (OCH*)4 was placed as a metal alkoxide, and γ-methacryloyloxybrobyltrimethoxysilane (CH1=C(CHs)COs(CH-*) was placed as a silane compound.
12 g of S i (OCH-)s).

252g of deionized water was sequentially charged, and while stirring, the temperature was raised until the internal temperature reached 80℃, and after confirming that it had reached 80℃,
Add 0.024g of 36% hydrochloric acid aqueous solution, and in that state, 8
The reaction was allowed to continue for hours. The pH of this reaction system is 5.1-6
．． It was 1.

After the reaction was completed, stirring was stopped, and the reactant precipitated. This precipitate was filtered off, washed with acetone, and then dried at 105° C. for 12 hours using a superheated steam dryer.

As a result, 27 g of powder with an average particle size of 31.7 μm was obtained.

When the infrared absorption spectrum of this powder was examined, it was found that 16
Absorption indicating a CC double bond was observed near 40 cm-'.

Comparative Example 1 The same procedure as in Example 1 was carried out except that no silane compound was used. Even when various stirring conditions were selected, in all cases only agar-like gelled material was produced and no powder was obtained.

Example 2.3 The same procedure as Example 1 was carried out except that the amounts of metal alkoxide and silane compound used were changed as shown in Table 1. The results are shown together with the results of Example 1 and Comparative Example 1, and it can be seen from the results that the average particle diameter of the produced powder changes depending on the silane compound blending ratio.

Table 1 Table 2 Examples 4 to 23 The same procedure as Example 1 was carried out except that the metal alkoxide shown in Table 2 was used. The results are shown in Table 2.

Examples 24 and 25, Comparative Example 2 The same procedure as Example 1 was carried out except that the silane compounds shown in Table 3 were used. The results are shown in Table 3.

Table 3 Table 4 Examples 26 to 35 The same procedure as Example 1 was carried out except that the mixture shown in Table 4 was used as the metal alkoxide. The results are shown in Table 4.

Examples 36 to 41 The same procedures as Examples 11, 15, and 16 were carried out except that the ratio of the metal alkoxide and the silane compound was changed as shown in Table 5. The results are shown in Table 5 together with the results of Examples 11, 15, and 16.

Example 42 When the powders obtained in Examples 1 to 3 were each heat-treated at 700°C for 12 hours, neither particle destruction nor interparticle sintering occurred, and metal oxide powders containing no organic components were obtained. I got a body.

Table 5 Procedural Amendments (Effects of the Invention) According to the method of the present invention, metal oxide condensates can be easily obtained without using expensive pulverization equipment or water-immiscible liquids, and compared to conventional techniques. It is possible to obtain a powder with less foreign matter contamination compared to the conventional method.

In addition, since the powder obtained by the method of the present invention contains polymerizable unsaturated groups, the reactivity of these unsaturated groups can be utilized to form organic compounds.
This is an excellent material that enables the production of composite materials with excellent inorganic affinity.

1. Indication of the case Patent Application No. 1-48168 2. Name of the invention Method for producing powder 3. Person making the amendment Relationship to the case Patent applicant Mitsubishi, 2-3-19 Kyobashi, Chuo-ku, Tokyo (603) Rayon Co., Ltd. President Yata Nagai 4, Agent 2-3-19 Kyobashi, Chuo-ku, Tokyo 104 "Detailed explanation of the invention" column of the specification subject to voluntary amendment 1) Page 6 of the specification Correct "yttrium mepropoxide" in lines 8 and 9 to "yttrium trismypropoxide."

2) r9 on page 9, line 19 to page 10, line 1 of the specification:
95 to... more preferred. ' r5:95-70
: Preferably 30. ” is corrected.

3) Correct r27gJ to "25g" on page 12, line 8 of the specification.

4) Row of Example 26 in Table 4 on page 16 of the specification, Example 2
7 row, Example 28 row, Example 33 row, and Example 3
Correct "r A 1 (-1-C4Hs) s" in row 5 to r A 1 (0-i, -C4H,) s J respectively.

5) rTi (C2Hs)4J in the row of Example 29, the row of Example 33, and the row of Example 34 in the same table are each rTi
(OC2Hs) Corrected to 4J.

Claims (1)

[Claims] 1) A method for producing a metal oxide powder, in which a silane compound having one or more alkoxide groups and a polymerizable unsaturated bond and a metal alkoxide are co-hydrolyzed in a fluidized aqueous medium.