JP2002363539A - Pore sealing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve room temperature curing with one liquid which has a high solid content, and easily penetrates into small pores generated in a sprayed material, and cures after penetration to exhibit a sealing effect. It is intended to provide a possible sealing agent. SOLUTION: The composition contains at least (a) a predetermined alkoxysilane compound or a partially hydrolyzed condensate thereof, and (b) a curing catalyst, and the viscosity of the component (a) at 25 ° C is 20 to 1000 mPa · s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-part cold curing type sealing agent which is used as a sealing agent for blocking micropores existing in a film when a film is formed on the surface of the material.

[0002]

2. Description of the Related Art Conventionally, a sealing agent has penetrated into micropores formed when a film is formed on the surface of a material by, for example, thermal spraying and solidified inside, thereby closing the micropores. Sealing agents are used to protect the liquid from intrusion of various gases and liquids.

[0003] As this sealing agent, fats and oils, waxes,
Epoxy resin, polyurethane resin, polyester resin,
Synthetic resin sealing agents such as phenolic resins, ceramic sealing agents such as water glass, and inorganic sealing agents such as phosphates and dichromates are known. I have been.

[0004]

However, the above-mentioned sealing agent may not be able to penetrate into the small pores generated in the sprayed material to the inside thereof, and may only cover the surface. In this case, peeling was apt to occur, and the sealing effect was not sufficient.

In view of the above, the present invention provides a one-part liquid which has a high solid content, easily penetrates into small pores formed in a sprayed material, and cures after penetration to exhibit a sealing effect. It is intended to provide a possible sealing agent.

[0006]

SUMMARY OF THE INVENTION The present invention, (a) the following chemical alkoxysilane compound represented by the formula (1) or a partial hydrolytic condensate thereof _{^{R 1 n Si (OR 2)}} 4-n (1) ( Formula Wherein R ¹ is a substituted or unsubstituted C 1-8
A valent hydrocarbon group, R ² is an alkyl group having 1 to 4 carbon atoms,
n shows the integer of 0-3. Further, R ¹ may be the same or different. The above problem was solved by using a sealing agent containing at least (b) a curing catalyst and having a viscosity at 25 ° C. of the component (a) of 20 to 1000 mPa · s.

Since the component (a) having the viscosity in the above-mentioned predetermined range is used, the component (a) is not completely hydrolyzed. For this reason, even if the solid content of the obtained sealing agent is increased, it can be smoothly penetrated into pores having a small pore diameter. In addition, since it contains the component (b), it can be cured after permeation and can be sealed.

[0008]

Embodiments of the present invention will be described below. One-part cold curing type sealing agent according to the present invention,
The composition contains at least an alkoxysilane compound or a partially hydrolyzed condensate thereof as a component (a) and a curing catalyst as a component (b).

[0009] The alkoxysilane compound constituting the component (a) refers to a silicon compound represented by the following chemical formula _{^{(1) R 1 n Si (}} OR 2) 4-n (1). In the chemical formula (1), R ¹ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and R ² represents an alkyl group having 1 to 4 carbon atoms. Further, R ¹ may be the same or different. Further, n is preferably an integer of 0 to 3, 1 or 2
Is preferred. This is because if n is 4, it will not be an alkoxysilane compound, and if n is 1 or 2, a flexible condensate is easily obtained.

Examples of such alkoxysilane compounds include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltributoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, dimethyldimethoxysilane, dimethyl Examples include diethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, and the like, and mixtures thereof.

The partially hydrolyzed condensate of the alkoxysilane compound constituting the above-mentioned component (a) is obtained by adding water to the above-mentioned alkoxysilane compound and heating the mixture with stirring in the presence of a catalyst. Is obtained by causing hydrolysis and condensation.

The degree of hydrolysis and condensation of the component (a) can be determined by viscosity. The viscosity of the component (a) at 25 ° C. is preferably 20 to 1000 mPa · s, and more preferably 25 to 500 mPa · s. 20
If it is smaller than mPa · s, the sealing agent may be diffused at the time of application and a sufficient sealing effect may not be obtained. On the other hand, 1000
If it is larger than mPa · s, the sealing agent may not easily penetrate into the pores, and the sealing effect may not be obtained.

In the present invention, the viscosity is measured at 25 ° C. as described above using a Brookfield type rotational viscometer (BM type,
No. 2 rotors, 60
It refers to the value measured in rpm.

The above hydrolysis and condensation can be carried out by diluting the component (a) with a diluent. When this diluent is used, the hydrolysis reaction and the condensation reaction can be performed more easily. The diluent is not particularly limited as long as it can dissolve the component (a).
For example, alcohols such as methanol, ethanol, propanol and butanol, aromatic compounds such as benzene and toluene, and cellosolves such as methyl cellosolve, butyl cellosolve, cellosolve acetate and the like can be mentioned.

The curing catalyst constituting the component (b) refers to a catalyst for sufficiently condensing and curing the component (a), for example, an organotin compound, an organotitanium compound,
One type selected from organoaluminum compounds and the like, or a mixture of two or more types thereof can be mentioned.

Among the above-mentioned curing catalysts, when a catalyst that cures the component (a) at room temperature is used, there is no influence of corrosion on the coated substrate and the curing time can be adjusted according to the use conditions. It is more preferable in some respects. Examples of such catalysts include organic tin compounds such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, organic titanium compounds such as tetraisopropyl titanate, tetrabutyl titanate and oligomers thereof, aluminum triisopropoxide, and aluminum tris
and organic aluminum compounds such as ec-butoxide.

The amount of the curing catalyst used is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the component (a).
0.2 to 3 parts by weight is preferred. If the amount is less than 0.1 part by weight, the curing speed after application is low, and in some cases, it may take an extremely long time. On the other hand, if it is more than 10 parts by weight, the compounded sealing agent may be non-uniform, or the curing may be too fast, resulting in poor workability.

The one-part cold curing type sealing agent according to the present invention can be subjected to a sealing treatment at room temperature by applying it to a target material having a film such as a primary rust preventive film. .

Next, a method of performing a sealing treatment using the one-part cold curing type sealing agent according to the present invention will be described.
First, the sealing agent is applied to the primary film of the target material by a method such as spraying, dipping, brushing, or the like, and the pores and cracks of the primary film are impregnated with the sealing agent. Further, after degassing the primary coating under reduced pressure, the primary coating may be impregnated with a sealing agent. Next, the above-mentioned material is left at normal temperature for 5 to 20 hours. As a result, the condensation of the component (a) further progresses, and the polysiloxane is cured in the pores and cracks, thereby effecting the sealing. When heating is performed, curing by condensation of the component (a) is promoted.

[0020]

The present invention will be described below in more detail with reference to examples. (Synthesis Example 1) Stirrer, heating jacket, condenser,
259 parts by weight of methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM13) and diphenyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM202) in a 1-liter four-necked flask equipped with a dropping funnel and a thermometer.
124 parts by weight, 50 parts by weight of methanol, and tetra-n
-Butoxytitanium (Nippon Soda Co., Ltd .: B-1) 0.3
A part by weight of the mixture was charged.

Next, while maintaining the liquid temperature at 20 ° C., 37 parts by weight of ion-exchanged water was added dropwise over 30 minutes. Thereafter, the temperature of the solution was gradually raised to 90 ° C., and methanol was removed from the hydrolysis-condensation and methanol in the diluent. A liquid was obtained. The obtained condensation liquid was a transparent liquid having a viscosity of 110 mPa · s (25 ° C.). The viscosity was measured using a Brookfield-type rotational viscometer (BM) according to the method described in JIS K 6833.
No. 1), manufactured by Tokimec Co., Ltd.). The measurement was performed at 60 rpm with two rotors.

Example 1 Condensate 1 prepared in Synthesis Example 1
2 parts by weight of tetra-n-butoxytitanium (Nippon Soda Co., Ltd .: B-1) was added to 00 parts by weight to prepare a mixture.

The obtained mixed liquid was sprayed with zinc and sprayed 5 cm ×
It was applied to a sprayed coating of a 10 cm steel plate (manufactured by Niigata Metallicon Co., Ltd.) under the following conditions, and the sealing effect was evaluated by the following evaluation test. Table 1 shows the results.

[Coating conditions] Material surface treatment: A blast treatment (grit 100 #) was performed as a pretreatment.・ Spraying method: Flame spraying using oxygen-acetylene gas ・ Spraying material: Zinc ・ Thick sprayed film: 70 μm ・ Coating method: Air spraying (caliber 0.3 mm, ejection pressure 0.13 MPa, manufactured by Meiji Kikai Seisakusho) The coating was applied from a distance of 20 cm.・ Coating amount: 35 g / m ²・ Curing condition: 25 ° C. for 10 hours

[Evaluation Test] (1) Salt Water Resistance Test According to the corrosion resistance test of the thermal sprayed coating of JIS H 8300,
The test piece was immersed in a 3% saline solution at 40 ° C. for 72 hours, and the coated surface was visually inspected for swelling, peeling, presence or absence and degree of red rust.

(2) Coloring test of potassium ferrocyanide To evaluate the acid permeability, potassium ferrocyanide was dissolved in distilled water to prepare a 3% solution, and sulfuric acid was added to adjust the pH to 4.5 to 5.0. To this, octadecyl monomethyl ammonium sulfate was added as a surfactant in 0.1 ml.
The test piece was immersed every 12 hours for 60 minutes at room temperature for 60 minutes, and this operation was repeated six times. During that time, the coloration of Prussian blue due to the reaction between potassium ferrocyanide and iron rust was observed.

Comparative Example 1 A comparative compounding liquid was prepared by mixing 100 parts by weight of a silica-based sealing agent (ethyl silicate 40, manufactured by Tama Chemical Industry Co., Ltd.) and 2 parts by weight of the above-mentioned tetra-n-butoxytitanium. . Ethyl silicate 40 has a viscosity of 3 mP
a · s (25 ° C.). The viscosity was measured by the same method as described above. The sealing effect was evaluated in the same manner as in Example 1 except that the above-mentioned comparative compounding liquid was used. Table 1 shows the results.

[0028]

[Table 1]

(Example 2) Thermal spray coating of a 5 cm x 10 cm steel sheet (made by Japan Metallizing Rust Prevention Association) prepared by applying the mixed solution obtained in Example 1 by arc spraying of a pseudo alloy of aluminum and zinc. Under the following conditions,
The sealing effect was evaluated by the following evaluation test. Table 2 shows the results.

[Coating conditions] Thermal spraying: Simultaneous arc spraying of blasted aluminum and zinc (Al / Zn = 55/45 (volume ratio))
Was done. -Sprayed thick film: 100 µm, 200 µm-Coating method: Coated from a position 20 cm away from the sprayed surface by air spray (0.3 mm in diameter, ejection pressure 0.13 MPa, manufactured by Meiji Kikai Seisakusho).・ Coating amount: 150 g / m ²・ Drying time: 24 hours

[Evaluation Test] (1) Saltwater resistance test Same as above (2) Potassium ferrocyanide color test As above (3) 1N hydrochloric acid 1 hour immersion test The test piece was immersed in 1N hydrochloric acid at 23 ° C. for 1 hour. The presence and degree of foaming were visually observed.

Comparative Example 2 The sealing effect was evaluated in the same manner as in Example 2 except that the comparative compound solution prepared in Comparative Example 1 was used. Table 2 shows the results.

[0033]

[Table 2]

[0034]

According to the present invention, since the component (a) having a viscosity within a predetermined range is used, the component (a) is not completely hydrolyzed. For this reason, the obtained one-part cold curing sealing agent can smoothly penetrate into pores having a small pore diameter even when the solid content is high.

Further, since it contains the component (b), it can be cured after permeation and can be sealed.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nei Sugiyama 1-13, Shodaida, Hirakata-shi, Osaka Central Rika Kogyo Co., Ltd. (72) Inventor Juichi Komori, 1-13, Shodaida, Hirakata-shi, Osaka Chuo Rika Kogyo Co., Ltd. (72) Inventor Takashi Yanagihara 1-13, Sumida, Hirakata-shi, Osaka Central Rika Kogyo Co., Ltd. (72) Inventor Takeo Wada 4-69, Seiwadai Nishi 4-69, Kawanishi-shi, Hyogo (72) Inventor Yasuo Hirai 4-8, Shichijo-dori, Sakai City, Osaka (72) Inventor Nobuaki Umino 1-35-301, Konan-cho, Higashinada-ku, Kobe-shi, Hyogo Prefecture (72) Inventor Hideyuki Morita 3-1-1, Takahanadaira, Yokkaichi-shi, Mie Prefecture 20 F term (reference) 4H017 AA04 AA31 AB15 AC01 AD06 AE05 4J038 DL031 JC38 KA04 KA06 NA12 PB12 4K031 BA01 CB39 DA01 FA09

Claims (5)

[Claims] 1. A (a) the following chemical alkoxysilane compound represented by the formula (1) or a partial hydrolytic condensate thereof _{^{R 1 n Si (OR 2)}} 4-n (1) ( wherein, R ¹ is a substituted or unsubstituted Substituted 1-8 carbon atoms
A valent hydrocarbon group, R ² is an alkyl group having 1 to 4 carbon atoms,
n shows the integer of 0-3. Further, R ¹ may be the same or different. ) And (b) a one-part cold-setting sealing agent containing at least a curing catalyst and having a viscosity at 25 ° C of the component (a) of 20 to 1000 mPa · s. 2. The one-part cold-setting sealing agent according to claim 1, wherein n is 1 or 2. 3. The one-part cold curing type sealing agent according to claim 1, wherein the curing catalyst is one or a mixture of two or more kinds selected from an organotin compound, an organotitanium compound and an organoaluminum compound. 4. The one-part cold curing type sealing according to claim 1, wherein the amount of the curing catalyst used is 0.1 to 10 parts by weight based on 100 parts by weight of the component (a). Pores. 5. A material having a primary rust-preventive coating,
A coating material having a coating film obtained by applying the sealing agent according to any one of claims 1 to 4.