JP3520583B2 - Coated inorganic powder and method for producing the same, and coating agent for inorganic powder and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated inorganic powder, a method for producing the same, a coating agent for inorganic powder and a method for producing the same.

[0002]

PRIOR ART Calcium carbonate, aluminum hydroxide,
Inorganic powder such as silica powder is usually used as a reinforced resin or artificial marble by coating with a silane coupler (generally RSiX ₃ : X is a hydrolyzable group, R is a functional group) and mixed with the resin. . However, the binding force between the inorganic powder and the resin and the binding force between the inorganic powders are not sufficient, and the strength, water resistance and durability are insufficient, which may cause a problem.

[0003]

Therefore, the present inventor has earnestly studied in order to improve the adhesion between the inorganic powder and the resin, or between the inorganic powders, and arrived at the present invention.

[0004]

That is, the gist of the present invention is to provide an alkoxysilane, an organic compound having two or more functional groups capable of reacting with two or more hydroxyl groups obtained by hydrolyzing an alkoxysilane, and water. the formulation is obtained by blending, it was adhered to the raw inorganic powder coated obtained by drying the inorganic powder, and the amount of alkoxysilane and which theoretically 100% hydrolysis amounts than water After aging the contained liquid at pH 3 or lower, water is further added to adjust the pH to 4 or lower, and an organic compound having 2 or more functional groups capable of reacting with 2 or more hydroxyl groups of this partial hydrolyzate is added. And a method for producing a coating agent for inorganic powder.

The present invention will be described in detail below. First, examples of the raw material inorganic powder in the present invention include inorganic powders such as calcium carbonate, graphite, carbon black, boron, titanium oxide, iron oxide, calcium hydroxide, calcium silicate, and natural silica, which are mixed in various matrices. However, any inorganic powder that is preferably surface-modified for the purpose of blending with a matrix of resin or the like can be used and is not particularly limited. next,
As the alkoxysilane in the present invention, a tetraalkoxysilane monomer and / or oligomer such as tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane is usually used.

In order to further improve the adhesion between the inorganic powder and the coating film, it is particularly preferable to use tetramethoxysilane among these. In this case, tetramethoxysilane is obtained by a method such as a reaction between silicon tetrachloride and methanol, a reaction between metallic silicon and methanol,
And / or a partial hydrolyzate thereof can be used, but impurities can be easily removed by refining the raw material, and hydrochloric acid does not form as a by-product, which does not cause a problem of equipment corrosion. For applications that need to be removed, it is desirable to use tetramethoxysilane obtained by reacting silicon and methanol, and / or a partial hydrolyzate thereof. In addition, when obtaining an alkoxysilane other than tetramethoxysilane, a production method by a reaction using various alcohols can be adopted according to the above method.

It has been suggested that the tetramethoxysilane monomer itself is highly toxic such that it invades the cornea of the eye and causes vapor damage. Also, because of its high activity,
When working, it may generate heat and bump. Further, the coating agent containing a large amount of monomer tends to gradually change its performance due to the reaction of the monomer during storage. In this respect, by using an oligomer which is a partially hydrolyzed polycondensate (hereinafter referred to as tetramethoxysilane oligomer) obtained by partially hydrolyzing and polycondensing a monomer of tetramethoxysilane, these can be dealt with. It is possible to provide a coating agent that exhibits excellent coating film properties over a long period of time, has reduced toxicity, and has excellent workability.

The hydrolysis reaction itself to obtain an alkoxysilane oligomer can be carried out by a known method,
For example, a predetermined amount of water is added to the above-mentioned tetramethoxysilane monomer, and the reaction is usually carried out at about room temperature to 100 ° C. in the presence of an acid catalyst while distilling off the alcohol by-produced. Methoxysilane is hydrolyzed by this reaction, and liquid tetramethoxysilane oligomer having two or more hydroxyl groups (conventional average degree of polymerization is 2 by condensation reaction).
~ 8, mostly 3-7) is obtained as a partial hydrolyzate. The degree of hydrolysis can be appropriately adjusted depending on the amount of water used, but in the present invention, it is usually 20 to
It is selected from about 80%, preferably about 30 to 60%.
When it is 20% or less, the residual monomer ratio is high and the productivity is low. If it is 80% or more, the obtained coating agent tends to gel. The hydrolysis rate of 100% means that the theoretical amount of water necessary for hydrolytically condensing all the hydrolyzable groups of the alkoxysilane, that is, the case where water in an amount of 1/2 of the number of moles of the alkoxy group is added. .

The water used at this time is not particularly limited and may be ordinary tap water, but dechlorinating water, ultrapure water or the like may be preferably used depending on the use and purpose, and therefore may be appropriately selected. For example, by using dechlorinated water, the corrosion resistance of the inorganic powder after coating becomes more excellent.
The oligomer thus obtained usually contains 2 to 1 of monomers.
About 0% is contained. When this monomer is contained, the storage stability of the coating liquid is poor, the viscosity may increase during storage, and it may be difficult to form a coating film. Therefore, the content of the monomer is 1% by weight or less, preferably 0.3%. It is advisable to remove the monomer so that the content of the monomer becomes less than or equal to weight%. This monomer removal can be carried out by flash distillation, vacuum distillation, inert gas blowing, or the like. Even when an alkoxysilane other than tetramethoxysilane is used to form a partial hydrolyzate, the hydrolysis reaction and the like can be carried out by an operation according to the above method.

The amount of water added is 200 to 100,000 parts by weight, preferably 350,000 parts by weight, based on 100 parts by weight of alkoxysilane. The addition method is preferably such that at least an amount of water capable of theoretically hydrolyzing 100% of the alkoxysilane (hereinafter referred to as “hydrolysis 100% equivalent of water”) is added, and in some cases, a catalyst component such as an acid is appropriately added. After adding an additive, the hydrolysis reaction is sufficiently advanced at a pH of 3 or less, preferably 2 or less, and after aging described below, further water is further added to adjust the pH to 3 to 4, and the organic compound described below is further added. If added, a coating liquid with excellent storage stability can be obtained, and the adhesion between the resulting coating film and the inorganic powder, the adhesion between the inorganic powders, and the adhesion between the inorganic powder and the resin component The properties such as are remarkably excellent.

Here, 100% equivalent of water by hydrolysis means
It is the same as the above definition that the amount of water is more than the amount necessary to hydrolyze all the hydrolyzable groups of the alkoxysilane monomer and / or the oligomer thereof, that is, the alkoxy groups. The same applies to the case of using an alkoxysilane oligomer, which means water in an amount equal to or more than the amount necessary to hydrolyze the remaining alkoxy groups.

As described above, any amount may be used as long as the hydrolysis is 100% equivalent or more.
The amount is preferably 1 to 4 times, more preferably 1 to 2 times, particularly preferably 1 to 1.5 times, and further preferably 1 to 1.2 times the% equivalent.

In the present invention, a curing catalyst can be added if necessary. Examples of the catalyst include inorganic acids such as hydrochloric acid, acetic acid, nitric acid, formic acid, sulfuric acid and phosphoric acid, organic acids such as paratoluenesulfonic acid, benzoic acid and phthalic acid, alkali catalysts such as potassium hydroxide and sodium hydroxide, Organic metal compounds, metal alkoxides, for example, organic tin compounds such as dibutyltin dilaurylate, dibutyltin dioctiate, dibutyltin diacetate, aluminum tris (acetylacetonate), titanium tetrakis (acetylacetonate), titanium bis (butoxy) bis (acetyl). Acetonate), titanium bis (isopropoxy) bis (acetylacetonate), zirconium tetrakis (acetylacetonate), zirconium bis (butoxy) bis (acetylacetonate) and zirconium bis (isopropoxy) bis. Acetylacetonate) and other metal chelate compounds, boron butoxide, etc., but acetic acid, maleic acid, etc. are excellent in terms of storage stability of the coating solution and hardness and flexibility of the obtained coating film. , Oxalic acid, fumaric acid, and metal alkoxides, particularly preferably one or more of strong acids having a pKa of 2 or less are preferably used.

The desired catalyst type can be appropriately selected depending on the type of the inorganic powder to be coated and the application. For example, when a strong acid such as hydrochloric acid or nitric acid is used as a catalyst, the solution has good storage stability, the time required for aging described below can be shortened, and the hardness of the obtained coating film is excellent, but particularly corrosion It may be better to avoid it for easy use. On the other hand, for example, maleic acid is desirable because it has little fear of corrosion and the like, requires a relatively short aging time, and has excellent properties such as hardness of the obtained coating film and storage stability in liquid.

The amount of these catalyst components added is not particularly limited as long as it can exhibit the function as a catalyst, but usually, it is usually 100 parts by weight of alkoxysilane.
It is selected from the range of about 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight. The method of blending these components is not particularly limited, and a more uniform blend may be prepared by, for example, using a catalyst component dissolved in water in advance, or blending with stirring. When a catalyst that is easily decomposed by water or other solvent is used, it is preferable to mix this with the organic silicon compound and / or its partially hydrolyzed polycondensate, and mix with water or other solvent before use. Further, the catalyst component may be added to other components when used.

By passing through the aging step, the partial cross-linking reaction due to hydrolysis and condensation of the alkoxysilane sufficiently proceeds, and the properties of the obtained coating film, and thus the properties of the coated inorganic powder, become excellent. It is preferable to add the reactive organic compound described below after the aging described below. The liquid containing the alkoxysilane and 100% equivalent of hydrolyzed water may be aged by allowing the liquid to stand, but may be stirred. The time for leaving is sufficient for the above-mentioned partial crosslinking reaction to proceed to a sufficient extent to obtain the desired film characteristics, and depends on the presence or absence of a catalyst and its type.

At the time of ripening, pH is 3 or less, preferably pH 1
It is desirable to carry out hydrolysis with stirring for 1 to 180 minutes, usually for about 10 to 20 minutes. If hydrolysis is carried out at pH 3 or higher, gelation may occur depending on the amount of water depending on the case. After obtaining a clear liquid in this way, further 1-2
Leave for hours. The time required for aging is also affected by the ambient temperature, and in extreme cold regions it may be better to take measures such as heating to around 20 ° C. Generally, aging proceeds rapidly at high temperatures, but gelation occurs when heated to 100 ° C. or higher, so heating to 50 to 60 ° C. is suitable at most.

After the aging, water and various other solvents or dispersion media can be further added. When ripening at pH 3 or less, these are added for convenience of use and pH 3 to 5,
It is desirable to use a weak acid having a pH of about 3 to 4.
This is because a strong acid having a pH of 3 or less is inconvenient to use, and when it is neutral to alkaline, it easily gels and may cause a problem in storage stability of the liquid. If more water is added after aging, the water content is 100
Generally, 20 to 100,000 parts by weight, preferably 2 with respect to 100 parts by weight of alkoxysilane, is added together with% equivalent of water.
00-50000, more preferably 350-35,000
0 parts by weight. If it is 20 parts by weight or less, there is a risk that the storage stability of the obtained coating liquid may be lowered, or sudden boiling may occur due to rapid heat generation due to the hydrolysis reaction. Also, 100,
When it is 000 weight or more, the obtained coating becomes extremely thin, and the effect of surface modification becomes low.

In the present invention, the above-mentioned hydrolyzate of alkoxysilane is blended with a reactive organic compound having two or more functional groups capable of undergoing a condensation reaction with two or more hydroxyl groups of the alkoxysilane. That is, the hydrolyzate of the alkoxysilane of the present invention has a large number of reactive groups capable of being hydrolyzed and polycondensed, such as hydroxyl groups. In the present invention, a reactive organic compound having two or more groups capable of undergoing hydrolytic polycondensation with these reactive groups is blended. The reactive organic compound is added by adding the reactive organic compound to a hydrolyzate of the above-mentioned alkoxysilane and / or a control solution prepared by further diluting the same with water to adjust the pH to 3 to 4 at room temperature for several minutes. A transparent liquid coating agent for inorganic powder can be obtained by a method such as mixing for several tens of minutes.

Examples of such a reactive organic compound include a carboxyl group, a hydroxyl group, an amino group,
Examples thereof include those having two or more alkoxy groups and the like (excluding the above-mentioned hydrolyzate), and specifically, for example,

(I) Silane coupling agent (generally R
SiX ₃ : X is a hydrolyzable group, R is a functional group) (ii) Alkylalkoxy silicones (iii) Polymers such as acrylic resin, epoxy resin, polyester resin, urethane resin (iv) 1,4-butanediol, Examples thereof include polyhydric alcohols such as glycerin, catechol, and resorcin. More specifically, for example, as the silane coupling agent (i),

Specific examples of the reactive organic compound include, but are preferably selected from the groups (i), (iii) and (iv).

More specifically, for example, as the silane coupling agent (i),

[0024]

[Chemical 1] Such as methyl acrylate,

[0025]

[Chemical 2] Epoxy type,

[0026]

[Chemical 3] Amino system, such as

[0027]

[Chemical 4] Such as vinyl,

[0028]

Embedded image HS—C ₃ H ₆ Si (OCH ₃ ) ₃ , HS-C
_{3 H 6 Si (OC 2 H} 5) 3, HS-C 3 H 6 Si (OC
₂ H ₄ OCH ₃ ) ₃ and the like, and the like.

Any of these can be preferably used, but it is also possible to appropriately select them depending on the type of inorganic powder to be coated and the type of matrix to be mixed.
For example, if the matrix is an acrylic resin, a methyl acrylate-based resin, if it is another general resin, a vinyl-based resin, and if it is mixed with a metal powder, an epoxy-based silane coupler is selected, a coating with particularly excellent adhesion is obtained. be able to. If the matrix is an inorganic substrate such as glass, excellent adhesion can be obtained by using any silane coupler. Further, as the alkyl alkoxy silicones of (ii),

[0030]

[Chemical 6] Etc.

Further, examples of the polymers (iii) include the followings. Acrylic resin (a) VP

[0032]

[Chemical 7]

(B) VP-γMTS; γ in the above VP structure
MTS (γ-methacryloxypropyltrimethoxysilane) added

[0034]

[Chemical 8] Epoxy resin

[0035]

[Chemical 9] Polyester resin

[0036]

[Chemical 10] Polyurethane resin

[0037]

[Chemical 11]

Two or more of the above organic compounds may be used in combination depending on the purpose. The organic compound is 1 to 900 parts by weight, preferably 30 to 100 parts by weight, based on 100 parts by weight of the alkoxysilane. If it is less than 1 part by weight, the compatibility between the coated inorganic powder and the matrix may be lost. If it exceeds 900 parts by weight, there is a risk that the adhesion between the coating film and the inorganic powder may be lost.
When the organic compound is incompatible with water and alkoxysilane, a silane coupler may be added.

These are examples of the reactive organic compounds that can be used in the present invention, and the reactive organic compounds that can be used in the present invention are not limited to these, and as described in the spirit of the present invention. Which has two or more functional groups capable of undergoing a condensation reaction with the above-mentioned hydrolyzate,
Either can be used. Further, the above reactive organic compounds may be used in combination of two or more depending on the purpose. For example, an epoxy resin and an epoxy-based silane coupler, an acrylic resin and an acrylic-based silane coupler, a polyester resin and an epoxy-based silane coupler, and the like, by using a resin component and a silane coupler together, the adhesion to the base material is improved, and The compatibility between the matrix component and the alkoxysilane can be further improved, and the characteristics of the coating film obtained can be further improved. At the time of combined use, two or more kinds may be blended in advance or each may be added to the hydrolyzate.

When a silane coupler is used as the reactive organic compound, water is added to hydrolyze it. At this time, even if added together with the silane coupler,
Alternatively, when hydrolyzing 100% equivalent or more of water to hydrolyze tetramethoxysilane in advance, it may be added together. When blending the hydrolyzate and the reactive organic compound, a solvent, a dispersion medium, a curing catalyst and the like can be added, if necessary. As the solvent, those having compatibility with both the aged product and the reaction-produced organic compound are suitable, and examples thereof include alcohols, glycol derivatives, hydrocarbons, esters, ketones, and ethers, one kind or two kinds. The above can be mixed and used.

Specific examples of alcohols include methanol, ethanol, isopropyl alcohol, n-butanol, isobutanol, and octanol, and examples of glycol derivatives include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene. Examples thereof include glycol mono n-propyl ether and ethylene glycol mono n-butyl ether.

The hydrocarbons include benzene, kerosene,
Toluene, xylene, etc. can be used, and as esters,
Methyl acetate, ethyl acetate, butyl acetate, methyl acetoacetate, ethyl acetoacetate and the like can be used. Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and acetylacetone, and ethers such as ethyl ether, butyl ether, 2 methyl cellosolve, ethyl cellosolve, dioxane, furan and tetrahydrofuran can be used.

In some cases, a dispersion medium can also be used. As the dispersion medium to be used, for example, a water-surfactant system is suitable, and as the surfactant, anionic, cationic or nonionic ones are generally used. As the anionic surfactant, carboxylate, sulfonate,
As a cationic one such as a sulfuric acid ester salt or a phosphoric acid ester, a salt of an organic or inorganic acid of a primary to tertiary amine,
Quaternary ammonium salts, polyoxyethylene alkylamine salts and the like, and further nonionic ones include sorbitan dialkyl esters, ethylene glycol condensates of sorbitan alkyl esters, aliphatic alcohol polyethylene glycol condensates, alkylphenol polyethylene glycol condensates, polypropylene. Glycol polyethylene glycol condensate and the like.

These surfactants are generally used in an amount of 0.1 to 5% with respect to the aged product. When dispersing (emulsifying), an appropriate amount of water is used and a homomixer is used. A known method such as colloid mill or ultrasonic wave can be used. The content of the hydrolyzate is preferably 50 to 300 parts by weight, more preferably 100 to 250 parts by weight, based on 100 parts by weight of the organic compound copolymer resin. Fifty
If it is less than 1 part by weight, the bending rigidity decreases, which is not preferable.
If the amount is 300 parts by weight or more, the adhesion to the substrate decreases, which is not preferable.

Of these solvents and dispersion media, it is usually preferable to use a solvent because the physical properties of the coating film obtained and the stability of the coating liquid are excellent. Regarding the type of solvent, it is sufficient to select a suitable one for the desired characteristics of the coating film, coating conditions, etc.
For example, when using hydrocarbons such as benzene, toluene, xylene, and ketones such as methylethylketone, the solvent removal rate at the time of curing the coating film is appropriate, so that the surface gloss of the obtained coating film is particularly excellent. Moreover, a desired film thickness can be easily obtained. Other,
Generally, it may be appropriately selected depending on the type of reactive organic compound used and desired film characteristics. Incidentally, depending on the type of the reactive organic compound, there are many functional groups, and it may be desirable to further add a catalyst in order to improve the curing rate after film formation, but in general, it was added during the formation of an aged product. A catalyst is sufficient.

The order of addition when these solvents and catalysts are used is not particularly limited, and they may be added to the alkoxysilane hydrolyzate at the same time as the reactive organic compound, or the following compatible state is achieved. You may add it after that. The addition method is a conventional method, and it is preferable to stir it. For the coating treatment, for example, the following method is adopted. An aqueous liquid reactive compound is impregnated with the raw material inorganic powder and stirred. Then, it is dried at 100 to 150 ° C. to obtain a coated inorganic powder. Although the drying time depends on the amount of water, 1 minute to 60 minutes is usually sufficient.

[0047]

EXAMPLES The present invention will be described in more detail below with reference to examples. Parts and% are parts by weight and% by weight, unless otherwise specified. Example 1 [Synthesis of tetramethoxysilane oligomer] To a 500 ml four-necked round bottom flask equipped with a stirrer, a condenser for reflux and a thermometer, 234 g of tetramethoxysilane and 74 g of methanol were added and mixed, and then a mixture of 0. 22.2 g of 05% hydrochloric acid was added, and a hydrolysis reaction was performed at an internal temperature of 65 ° C. for 2 hours.

Then, the condenser is replaced with a distilling pipe,
The temperature was raised until the internal temperature reached 130 ° C., and methanol was distilled off. Thus, a partially hydrolyzed condensate was obtained (partial hydrolysis rate 40%). An oligomer having a degree of polymerization of 2 to 8 was confirmed, and the weight average molecular weight was 550. The amount of monomer in the tetramethoxysilane oligomer was 5%. Subsequently, the tetramethoxysilane oligomer was placed in a flask heated to 130 ° C., the vaporized monomer was discharged out of the system together with an inert gas, and the temperature was raised to 150 ° C. and maintained for 3 hours. The amount of monomers in the tetramethoxysilane oligomer thus obtained was 0.2%.

Tetramethoxysilane thus obtained
66 parts by weight of dechlorinated water was added to 100 parts by weight of the oligomer. Next, maleic acid was added to adjust the pH to 1.5. After stirring at room temperature for 5 minutes, a transparent concentrate was obtained. Then, 20,000 parts by weight of dechlorinated water was added. Subsequently, 30 parts by weight of an epoxy silane coupler (manufactured by Nippon Unicar Co., Ltd., product number A-187) was added, and the mixture was stirred at room temperature for 1 hour. The pH of the obtained liquid product was 3.7. To 2500 parts by weight of this liquid material, 1000 g of aluminum hydroxide powder (product number OC-20 manufactured by Alcoa Kasei Co., Ltd.)
00 average particle size 47 μm) and stirred with a Henschel mixer at 1500 rpm for 20 minutes. Then, pass steam at 110 ° C through the jacket of the Henschel mixer, and
The inside of the Henschel mixer was heated to 0 ° C. or higher and heated for 30 minutes while stirring to obtain coated aluminum hydroxide powder.

Example 2 To 100 parts by weight of the tetramethoxysilane oligomer obtained in Example 1, dechlorinated water and maleic acid were added and p
It was adjusted to H1.0. Stir for 2 minutes at room temperature to obtain a clear concentrate. Subsequently, 1100 parts by weight of dechlorinated water was added. Methyl acrylate-based silane coupler (manufactured by Nippon Unicar, product number A-174) was used as an organic compound.
0 part by weight was added, and the mixture was stirred at room temperature for 5 hours to obtain a liquid substance.
This liquid had a pH of 2.0. To 2500 parts by weight of this liquid material, 1000 g of aluminum hydroxide powder (Alcoa Kasei Co., Ltd., product number C-385 average particle size 8 μm) was added and stirred for 20 minutes at 1500 rpm with a Henschel mixer. Then, at the Henschel mixer jacket, 110 ℃
Was passed through to heat the inside of the Henschel mixer to 100 ° C. or higher, and the mixture was heated for 30 minutes while stirring to obtain coated aluminum hydroxide powder.

Example 3 Tetramethoxysilane oligomer 10 obtained in [Synthesis of tetramethoxysilane oligomer] of Example 1
1 part by weight of maleic acid water (pH 1.
5) 60 parts by weight was added and stirred at room temperature for 5 minutes to obtain a transparent hydrolyzed solution. Then 20000 parts by weight of demineralized water were added. Subsequently, 30 parts by weight of an epoxy type silane coupler (manufactured by Nippon Conika Co., Ltd., product number A-187) was added, and the mixture was stirred at room temperature for 1 hour. P of the obtained coating liquid
H was 3.7.

To 2500 parts by weight of this coating solution, 1000 g of aluminum hydroxide powder (manufactured by Alcoa Kasei Co., Ltd.)
No. OC-2000 having an average particle size of 47 μm) was added and stirred with a Henschel mixer at 1500 rpm for 20 minutes. Then, steam of 110 ° C. was passed through the jacket of the Henschel mixer, the inside of the Henschel mixer was heated to 100 ° C. or higher, and heated for 30 minutes with stirring to obtain coated aluminum hydroxide powder.

Example 4 Tetramethoxysilane oligomer 10 obtained in [Synthesis of tetramethoxysilane oligomer] of Example 1
1 part by weight of maleic acid water (pH 1.
5) 60 parts by weight was added and stirred at room temperature for 5 minutes to obtain a transparent hydrolyzed solution. Next, 43 parts by weight of a vinyl-based silane coupler (KBM-1003 manufactured by Shin-Etsu Chemical) was added, and the mixture was stirred at room temperature for 1 hour. Then 14000 parts by weight of demineralized water were added. The pH of the obtained coating liquid was 3.3.

To 2500 parts by weight of this coating solution, 1000 g of aluminum hydroxide powder (manufactured by Alcoa Kasei Co., Ltd.)
No. C-385 having an average particle size of 8 μm) was added and stirred with a Henschel mixer at 1500 rpm for 20 minutes. After that, steam of 110 ° C is passed through the jacket of the Henschel mixer to heat the inside of the Henschel mixer to 100 ° C or higher,
The coated aluminum hydroxide powder was obtained by heating for 30 minutes with stirring.

Example 5 (Preparation of coating liquid)

To 100 parts by weight of the tetramethoxysilane oligomer obtained in Example 1, 25 parts by weight of 0.3% maleic acid water (pH 1.92) was added, and the mixture was stirred at room temperature for 30 minutes to give a transparent liquid. A new hydrolyzate of tetramethoxysilane oligomer was obtained. Then, the hydrolyzed water-solubilized product was diluted with 1500 parts by weight of dechlorinated water to obtain a transparent dilution adjustment liquid having a pH of 3.4. Next, in a Henschel mixer, calcium carbonate powder (manufactured by Ishizu Pharmaceutical Co., Ltd. special grade reagent: precipitated product average particle size: 9.9 μm specific surface area: 0.28 m ² / g) 50
After charging 0 parts by weight, steam of 110 ° C. was passed through the jacket of the Henschel mixer, the inside of the Henschel mixer was heated to 100 ° C. or higher, and heating was continued for 15 minutes while stirring to obtain a coated calcium carbonate powder. The obtained coated calcium carbonate powder had an agglomeration without aggregation and had an angle of repose of 44 degrees when measured using an "ABD type powder property measuring device". The sparse packing density is 0.65
It was g / cc, and when it was poured into water and mixed by shaking to confirm the wettability with water, the whole amount of calcium carbonate powder was wet and precipitated. Before coating, the raw calcium carbonate powder had a repose angle of 59 degrees and a loose packing density of 0.39 g.
/ Cc, wettability to water was such that the entire amount immediately wetted and settled.

Comparative Example 1 (Preparation of Hydrolysis Solution of Silane Coupler) 100 parts by weight of a vinyl silane coupler (manufactured by Nippon Unicar: A-171) was added to 1900 parts by weight of maleic acid water having a pH of 3.5, and the mixture was stirred at room temperature. After stirring for about 10 minutes, a transparent hydrolysis solution was obtained. (Coating treatment of calcium carbonate powder) Next, in a Henschel mixer, calcium carbonate powder (manufactured by Ishizu Pharmaceutical Co., Ltd. special grade reagent: precipitated product average particle size: 9.9 μm specific surface area: 0.2
8 m ² / g) 500 parts by weight was charged, and then 50 parts by weight of the silane coupler hydrolysis solution obtained in the above (Preparation of silane coupler hydrolysis solution) was added at room temperature to give 15
Stir at 00 rpm for 15 minutes at room temperature. Then, pass steam at 110 ° C through the jacket of the Henschel mixer,
The inside of the Henschel mixer was heated to 100 ° C. or higher, and the heating was continued for 15 minutes while stirring, and then cooled to take out calcium carbonate powder. The obtained calcium carbonate powder,
The angle of repose was 50 degrees when measured using an "ABD type powder property measuring device". The sparse packing density is 0.58g
It was / cc, and when it was poured into water and mixed by shaking to confirm its wettability with water, a part of the calcium carbonate powder floated and most of it precipitated.

Example 6 (Preparation of coating agent) 100 parts by weight of the hydrolyzate of tetramethoxysilane obtained in Example 1 was added to 1 part of dechlorinated water.
65 parts by weight of a vinyl-based silane coupler (manufactured by Nippon Unicar: A-171) was added to the adjustment liquid diluted with 130 parts by weight, and the mixture was stirred at room temperature for about 10 minutes to obtain a transparent coating agent. (Coating treatment of calcium carbonate powder) Next, in a Henschel mixer, calcium carbonate powder (manufactured by Ishizu Pharmaceutical Co., Ltd. special grade reagent: precipitated product average particle size: 9.9 μm specific surface area: 0.2
8 m ² / g) 500 parts by weight was added, then 50 parts by weight of the coating agent obtained in the above (Preparation of coating agent) was added at room temperature, heating was continued for 15 minutes while stirring, and coated calcium carbonate powder Got The obtained calcium carbonate powder was found to have an angle of repose of 44 degrees when measured using an "ABD type powder characteristic measuring device" without aggregation.
The loose packing density was 0.49 g / cc, and when the mixture was poured into water and mixed by shaking to confirm its wettability with water, the whole amount was immediately wet and settled.

[0059]

According to the present invention, it is possible to obtain an inorganic powder having excellent adhesion. Moreover, since various powder surfaces can be coated with a glassy film and various silane couplers can be used in combination, a remarkable effect can be exhibited in improving the adhesion between various fillers such as FRP and artificial marble and the filler. .

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hozumi Endo Hozumi Endo 1-1, Kurosaki Shiroishi, Hachimansai-ku, Kitakyushu Sanritsu Chemical Co., Ltd. Kurosaki Plant (72) Inventor Nobuyuki Matsuzoe 2-5-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Chemical Corporation (56) Reference JP-A-8-157771 (JP, A) JP-A-1-126375 (JP, A) JP-A-3-115379 (JP, A) JP-A-57-94057 ( JP, A) JP-A-8-143819 (JP, A) JP-A-6-298600 (JP, A) JP-A-8-157742 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 1/00-10/00 C09D 101/00-201/10 C09D 15/00-17/00 C09C 1/00-3/12 C01B 33/00-33/193

Claims (7)

(57) [Claims] 1. An alkoxysilane is hydrolyzed in water.
Hydrolysates, organic compounds having two or more functional groups capable of reacting with the hydroxyl groups of the hydrolyzate, and the main water
The coating liquid composed as, adhered to the raw material inorganic powder
A coated inorganic powder, which is obtained by drying after drying. 2. The hydrolyzate is hydrolyzed in the presence of water in an amount equal to or greater than the theoretical amount of 100% hydrolysis of the alkoxysilane.
The coated inorganic powder according to claim 1, characterized in that it has been solved . 3. The coated inorganic powder according to claim 1, wherein the organic compound is a silane coupling agent . 4. The alkoxysilane is tetramethoxysilane according to claim 1, wherein the alkoxysilane is tetramethoxysilane .
Coated inorganic powder according to. 5. The monomer content of the hydrolyzate is 1% by weight.
The coated inorganic powder according to any one of claims 1 to 4, wherein: 6. The hydrolyzate is based on the theory of an alkoxysilane.
In the presence of 1 to 4 times more water than the 100% hydrolyzable amount
No claim 1 characterized in that it is hydrolyzed.
6. The coated inorganic powder as described in any one of 5 above. 7. An organic compound for alkoxysilane
The weight ratio is 0.3 to 1.0.
The coated inorganic material according to any one of 1 to 6
powder.