JPH0214857A - Surface-treated inorganic material - Google Patents

Abstract

PURPOSE:To improve water repellency, oil repellency and non-adhesiveness of surface of an inorganic material by adding and bonding a flourine-containing silane compound expressed by a specific structural formula to the surface of the powdery or stable like inorganic material. CONSTITUTION:A powdery or stable like inorganic material is added to the solution containing a fluorine-containing silane compound expressed by the structural formula of general formula I and stirred or the fluorine-containing silane compound is directly added to the inorganic material vigorously stirred at ambient temperature or while heating. In this time, trihalogenosilyl group and trialkoxysilyl group of the fluorine-containing silane compound are reacted with hydroxyl group on the surface of inorganic material and bonded. Further, perfluoroalkyl group is oriented to the surface of inorganic material to provide water repellency, oil repellency and non-adhessiveness to the surface of inorganic material. Thereby water repellency, oil repellency and non-adhessiviness on the surface of inorganic material are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inorganic material having water repellency. More particularly, it relates to the inorganic material in the form of powder and short fibers suitable for use as a filler for resins. However, the new inorganic material of the present invention is not only used as a filler for resins.

[Prior art and problems] Conventional inorganic materials tend to adsorb water, and the adsorbed water on the surface (moves on the surface of the inorganic material) can reduce electrical and magnetic properties or cause oxidation of one surface layer. Or, again,
When this powder is used as a filler for resin, it may cause agglomeration of the powder.

There is a problem in that the temperature and humidity range for electronic devices to operate normally is extremely narrow.

In addition, inorganic materials have been treated with ordinary titanate and silicate coupling agents to improve their properties, but conventional titanate and silicate coupling agents are hydrocarbon-based and do not always have sufficient water resistance. I can't say that.

In order to solve these problems, surface treatment with a fluorine-based silane coupling agent has been proposed (Japanese Patent Laid-Open No. 60-87029). Examples of the fluorine silane coupling agent include compounds represented by the following formula.

Namely.

CF3- (CF2L -o-(co□)3-0-5i
(OCH3LCF, -(cFz)t-(C)1
．． )3-NH-(C112)3-5i (OCH3)
3CF, -(CF2)t -N)1- (c)1.
)3-Nll-3L (OCR,)3CF, -(CF2
)? -(CI□)3-0- (CH2)! -5l
(OCtli)iCF3- (CF, )6-CO
NH-(CH□), -3i (OCR,).

CF, -(CF2)? -(CI□)s-8i(O
Cll-)3CF, -(CF, ), -COO-(
CH□)3-5i(OCll3)3CF, -(CF
2L -(CI+2), -NH-(CH2)3-5i
C is also CF3- (CF2)v -0-(Cll□),
−08iCρ.

CF, -(CF2)7-NH-(C11□), -NH
-5i(OCll,)2CQ CF, -(CF2), -(C11□)3-0- (
CI□), -5i-(OCN, )yoCQ CF3- (CF, ), -(CI□), -5Boc
lzU et al.

However, all of these compounds are linear compounds that do not mix well with resins and have insufficient dispersibility.They generally have ether bonds and amino bonds, so they have poor thermal stability. Compounds having carboxylic acid ester or carboxylic acid amide bonds have somewhat improved thermal stability, but are still not sufficient, and on the contrary, chemical stability decreases.

[Knowledge related to solving the problem] As a result of intensive research to solve the above-mentioned problems, the present inventors found that an inorganic material whose surface was treated with a specific fluorine-containing silane coupling agent was more suitable. Ta.

[Structure of the invention] The present invention is based on the general formula % () (wherein R1 is H or a C1-S alkyl group, and X is CQ
, Br, 0C113, 0C2 (15) A fluorine-containing silane coupling agent represented by 0C113,0C2 (15) is adhesively bonded to the surface of the inorganic material.

The above-mentioned fluorine-containing silane coupling agent exhibits water repellency, oil repellency, and non-adhesiveness due to the perfluoroalkyl group, while the trihalogenosilyl group and trialkoxysilyl group react with water to become a trihydroxysilyl group, and further This has the property of forming dehydration, condensation, hydrogen bonding, etc., and bonding with hydroxyl groups present on the surface of the inorganic material.

In addition, the sulfonamide bond provides thermal and chemical stability compared to carboxylic acid ester and carboxylic acid amide type compounds, and a high yield of the hydrosilylation reaction during its synthesis. It has the effect of increasing water repellency, oil repellency, and non-stick properties. Additionally, the alkyl group bonded to the nitrogen atom increases compatibility with solvents. In the above general formula, the alkyl group of R1 may be either straight chain or branched chain. Moreover, an ether bond may exist in the middle.

The above-mentioned fluorine-containing silane coupling agent is produced as follows.

C,F1□SO,NR”CH,CH,=CH2(II)
N-allyl-N-alkyl perfluorooctyl sulfonamide represented by the general formula (wherein R1 is the same as above) and trihalogenosilane represented by the general formula H81X, (II) (wherein X is chlorine or bromine) in the presence of an additional catalyst, and if necessary the product is further reacted with methanol or ethanol.

As described above, in the fluorine-containing silane coupling agent of the present invention, its trihalosilyl group and trialkoxysilyl group react with water to form a trihydroxysilyl group, which dehydrates with the hydroxyl group present on the surface of the inorganic material. It strongly adsorbs even inorganic materials that form condensation or hydrogen bonds or do not have hydroxyl groups on the surface, and at the same time, the perfluoroalkyl groups arranged on the surface exhibit properties such as water repellency, oil repellency, and non-adhesion. Furthermore, the alkyl group and sulfonyl group bonded to the nitrogen atom in the compound represented by formula (1) increase the compatibility with resins or solvents, and also improve the adhesion with inorganic materials.

Inorganic materials to which the present invention is applied are not particularly limited, but specific examples include silicon oxide, tin oxide, titanium oxide, aluminum oxide, silicon nitride, graphite, zinc oxide, iron oxide, and graphite.

These include mica, glass fiber, carbon fiber, and asbestos.

The amount of the fluorine-containing silane coupling agent attached varies depending on the specific surface area of the inorganic material, but it is 0.1 to 20% of the inorganic material.
Can vary between weight percentages.

If it is less than 0.1 weight percent, there is no effect on water repellency, and if it is more than 20 weight percent.

There is no significant change in characteristics compared to the case below.

Furthermore, the present inventors found that the sulfonamide bond increases thermal and chemical stability, and the alkyl group bonded to the nitrogen atom increases the compatibility with solvents, which can be used for surface treatment of inorganic materials. Provides versatility in solvent selection.

As the surface treatment method for this inorganic material, there are wet methods and dry methods, and either method can be used in the present invention.

The wet method is carried out by adding the above inorganic material to a solution containing a fluorine-containing silane coupling agent represented by formula (1) and stirring. The solvent is preferably an organic solvent such as a halogenated hydrocarbon, alcohol, or ether, and is anhydrous or, if necessary, added with a small amount of an aqueous solution of an amine or acid.

The amine used here may be any of -class amines, secondary amines, and tertiary amines, but -class amines are particularly effective.

In addition, as the acid used, inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and organic acids such as formic acid, acetic acid, oxalic acid, and toluenesulfonic acid can be used.

In the aqueous solution of these amines or acids, water hydrolyzes the trihalogenosilyl group or trialkoxysilyl group of the fluorine-containing silane coupling agent to form a trihydroxysilyl group, which interacts with the hydroxyl group on the surface of the inorganic material. It also has a strong adsorption effect on inorganic materials that undergo dehydration condensation or do not have hydroxyl groups on their surfaces.

Furthermore, the acid and amine serve as catalysts that promote this hydrolysis and dehydration condensation.

The concentration of these amines or acids is suitably 15% by weight or less, preferably about 0.1 to 3% by weight, based on the total amount of the treatment solution.

When treating inorganic materials with these fluorine-containing silane coupling agent solutions, the treatment temperature varies depending on each solvent, but
It is carried out at a temperature range from room temperature to the boiling point of the solvent, and the solvent is usually evaporated after processing.

or separating inorganic materials by filtration.

In addition, if an anhydrous solvent is used or the treatment is performed at room temperature, an aqueous solution of amine or acid may be added as necessary.
Heat treatment is carried out at 0 to 95°C, preferably 60 to 80°C, or heat drying is carried out at 50 to 150°C, preferably 80 to 130°C without using an aqueous solution. These treatments are necessary to more firmly bond the fluorine-containing silane coupling agent to the inorganic material.

In the dry method, the inorganic material is vigorously stirred at room temperature or while heating, and the fluorine-containing silane coupling agent shown by the formula (() is added thereto as it is, or a solution of the stiffness dissolved in a solvent is added dropwise little by little. Again, the solvents mentioned for the wet method.

Catalysts (amines, acids), etc. can be used as well.

The treated material is heated again to evaporate the solvent and at the same time strengthen the bond between the fluorine-containing silane coupling agent and the inorganic powder.

The inorganic material treated with a fluorine-containing silane coupling agent in this manner can be used not only for its own purpose but also as a filler to be dispersed in a resin.

[Specific disclosure of the invention] The present invention will be specifically described below with reference to Examples.

Example 1 50 g of silica powder (particle size approximately 1 μm) and 500 g (containing 1% by weight of 10% dilute hydrochloric acid aqueous solution)
mQ (fluorine-containing silane coupling agent concentration: 0.1.1 and 5.10% by weight, respectively, based on the silica powder) was placed in an electric shaker, and vigorously mixed and stirred at room temperature for 10 minutes.

After the stirring was completed, the solvent was evaporated by heating to 100° C. to obtain silica powder treated with a fluorine-containing silane coupling agent. Substantially all of the added fluorine-containing silane coupling agent adhered to the silica powder.

When the infrared absorption spectrum of this silica powder was analyzed using a powder reflectance method, it was found that absorption based on C11 bond is at 2850 to 2950 cm-'', absorption based on sulfonamide bond is at 1390 cm-'', and absorption is based on sulfonamide bond at 1100 to 1300 cm-'.
Absorption based on CF bonds was observed on the surface, confirming the presence of a fluorine-containing silane coupling agent on the surface.

As a test for water repellency, this silica powder was placed in the electric loss machine described above, and was vigorously mixed and stirred with 500+ nQ water at room temperature for 15 minutes, and the water repellency was evaluated visually.

Comparative Example 1 C11□-Ca+2-CH20CII□CIl□C11 as a silane coupling agent
, SL (OCR,), The results of performing the same processing as in Example 1 are shown in Table 1 together with the results of Example 1.

table 50 g of alumina powder (particle size approximately 1 μl) was placed in an IQ Mitsuro flask equipped with a
-) 50 mQ was added dropwise over 1 hour. After the dripping is finished,
The solvent was removed by heating to 100° C. to obtain a fluorine-containing silane coupling agent powder.

As in Example 1, the presence of a fluorine-containing silane coupling agent on the surface was confirmed by an infrared absorption spectrum using a powder reflection method.

The water repellency test was conducted in the same manner as in Example 1.

Comparative Example 2 CF 3 C, H2CH2CH25l (OCHa) as a silane coupling agent
The same treatment as in Example 2 was performed using a. The results are shown in Table 2 together with the results of Example 2. The meanings of symbols in the table are the same as in Table 1.

Table 2 Example 3 50 g of silica powder (particle size approximately 10 μm) and fluorine-containing silane coupling agents such as C3+1□ C, F, 5O2N (C11□), 5i (OCI+
, ) 3 (containing 1% by weight of 10% IIcρ aqueous solution) and 500 mN were placed in an electric shaker and mixed and stirred at room temperature for 20 minutes.

and 0.1 respectively. There were four types: 1.5.10% by weight. After a predetermined period of time had elapsed, the infrared absorption spectrum of the treated powder obtained by heating to 100'C to evaporate the ethyl alcohol was measured by powder reflection method. As a result, C-H (2850-2950cm-1), SO2N
(1390cm'-") and C-F (1100-1
Absorption of 300 cm-') was observed, confirming the presence of the fluorine-containing silane coupling agent on the silica surface.

This powder was added to 50% by weight of epoxy resin (melamine-curing epoxy type manufactured by Tokyo Paint) and dispersed, applied to a bonded steel plate (made by Nippon Test Panel) to a thickness of 100 μm, and hardened at 140° C. for 20 minutes. This steel plate was placed in an autoclave and subjected to a water resistance test with water vapor under 5 atm for 2 hours to determine the water content. Table 3 shows the results.

Comparative Example 3 C11j-3i (OCI
The same treatment as in Example 3 was performed using I3), and the results are shown in Table 3 and compared with Example 3.

Example 4 50 g of silica powder (particle size: approximately IO μm) was placed in an IQ Mitsuro flask equipped with a thermometer, a stirrer, and a reflux device, and while stirring, the same fluorine-containing silane coupling agent solution as in Example 3 (5, to, 20.25 weight percent)
50 mQ was added dropwise over 1 hour. After finishing dropping, 10
The treated powder was heated to 0° C. to remove the solvent, and the infrared absorption spectrum of the obtained treated powder was measured in the same manner as in Example 3 to confirm the presence of the fluorine-containing silane coupling agent on the powder surface.

Furthermore, the results of a water resistance test similar to Example 3 are shown in Table 4.
It was shown to.

Comparative Example 4 The same CI and S as Comparative Example 3 were used as silane coupling agents.
The results of the same treatment and measurement as in Example 4 using j, (OCH,)3 are shown in Table 4 and compared with Example 4.

Example 5 The same treatment as in Example 3 was performed using 50 g of alumina powder (particle size of 5 μm or less). The results are shown in Table 5.

Comparative Example 5 Table 5 shows the results of performing the same treatment as in Example 5 using NH, (CI+2)3 St (OC113)3 as a silane coupling agent, and compared with Example 5.

Example 6 50 g of alumina powder (particle size: 5 μm or less) was treated and measured in the same manner as in Example 4. Table 6 shows the results.

Comparative Example 6 Table 6 shows the results of the same treatment and measurement as in Example 4 using Nll□(C1(□):, SL (OCH3)3) as a silane coupling agent, and the results are compared with Example 5. did.

Table Example 7 Glass fiber (diameter approx. 3 μm, average length approx. 50 μn+) 50
g and C112C as a fluorine-containing silane coupling agent)
+3 C&F engineering, 5O2N (CI+□)3Si (OCl
l, ) 3 acetone solution (10% IICQ aqueous solution 1
500+n1ll (including weight%) were placed in an electric loss vessel, and mixed and stirred at room temperature for 20 minutes.

CII□C113 C, F1□502N (CH,), Si (OCH3
) The amount of 3 is 0.1.1.5 respectively for glass fiber.
．． There were four levels of 10% by weight. After 30 minutes, 100℃
The infrared absorption spectrum of the glass fiber obtained by heating to evaporate the acetone was measured by the diffuse reflection method. As a result, C-1f (2850~2950cm-1
), SO,N (1390 cm-”) and C-F (1
100 to 1300 cm-'') was observed, and the presence of the above-mentioned fluorine-containing silane coupling agent was confirmed on the surface of the glass fiber.The glass fiber was added to an acrylic resin (manufactured by Tokyo Paint, self-curing type) at 50% by weight. The resulting acrylic resin was then stirred and dispersed, poured into a 10 cm x 10 cm x 10 cm mold, and cured at 150°C for 30 minutes.The resulting acrylic resin was placed in an autoclave and subjected to a water resistance test with steam for 2 hours at 5 atm. Table 7 shows the results of examining the water content.
Shown below.

Comparative Example 7 CH3Sl (OCH3
) 3 was used to carry out the same treatment as in Example 7, and the results are shown in Table 7 and compared with Example 7.

, -J″'-A5 se, ?rf7 positive 7F July 24, Hei I Bo 1

Claims (1)

[Claims] 1. General formula C_■F_1_7SO_2NR^1CH_2CH_2C
H_2SiX_3(I) (where R^2 is H or C_
1_ to_5 alkyl group, X is Cl, Br, OCH_3
, OC_2H_5) is adhesively bonded to the surface of an inorganic material in the form of powder or short fibers. 2. The inorganic material according to claim 1, wherein 0.1 to 20% by weight of the fluorine-containing silane coupling agent is adhesively bonded to the inorganic material.