JP3467369B2 - Rust prevention coating composition and rust prevention method for substrate - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for rust prevention of a substrate,
More specifically, by applying a coating agent to the surface of a metal material typified by aluminum or the like, or an inorganic material used in contact with a metal material such as stone or mortar,
A transparent film is formed to give excellent rust prevention and protection effects,
Moreover, the present invention relates to a rust preventive coating composition which is excellent in water resistance and can be easily applied at room temperature and high temperature, and a rust preventive method for a substrate.

[0002]

TECHNICAL BACKGROUND AND PROBLEMS OF THE INVENTION The surface of a metal material typified by aluminum is subject to acid rain, salt damage, etc., and the surface deteriorates, resulting in poor aesthetics. In addition, when an inorganic material such as mortar is placed or applied on a metal material, if rust occurs on the metal material, the rust penetrates into the inorganic material and causes stains on the surface of the base material, resulting in a visual appearance. It becomes discolored. The generation of rust gives the impression that the quality of the molded product and the exterior surface is deteriorated. In order to solve such a problem, a conventional method is to apply a generally known rust preventive agent (Japanese Patent Laid-Open No. 51-90).
No. 682), and a method using amino-modified siloxane as a rust preventive (see JP-A-6-57458). However, generally known waxes, rust preventives containing petrolatum, paraffin, carnauba wax and the like as the main components have insufficient water resistance and insufficient rust prevention during flooding or rainfall. Further, even when an amino-modified siloxane is used as a rust preventive, the rust preventive in an environment where the film of the rust preventive has insufficient strength and is susceptible to physical influences has been desired. It is generally known to use rust preventive oil made from mineral oil as a rust preventive method for metal materials. These rust preventive oils are used for temporary rust prevention during the storage, shaping process or transportation of metal materials, but the coating film easily falls off and has a long-term stable rust preventive effect. I haven't arrived. Further, a method is known in which a coating agent containing a silane compound or polysiloxane as a main component is applied to a porous inorganic material such as concrete to impart water repellency to prevent deterioration (JP-A-57-126878). Japanese Patent Laid-Open No. 62-197369, Japanese Patent Laid-Open No. 1-292089.
Japanese Patent Laid-Open Publication No. 2-150477) does not describe the rust preventive effect, and further improvement was required.

[0003]

An object of the present invention is to solve the above-mentioned problems and to provide a method for rust-proofing a base material. More specifically, it is used in contact with a metal material typified by aluminum or a metal material such as stone or mortar. By applying a coating agent to the surface of the inorganic material used, a transparent coating is formed to give excellent rust prevention and protection effects, and it has excellent water resistance and can be easily applied even at room temperature and high temperature. An object of the present invention is to provide an agent composition and a rust preventive method.

[0004]

The present inventor has conducted various studies in order to achieve the above object, and as a result, by blending silicone with a specific organothiol compound and using it as a rust preventive composition, it is represented by aluminum or the like. It provides excellent rust prevention and protection effects to inorganic materials used in contact with metallic materials such as stone materials and mortar, and has excellent water resistance and can be easily applied at room and high temperatures.
Coating measured with the pencil hardness test method (JISK5400)
The present invention has been accomplished by finding a rust preventive coating composition and a rust preventive method having a strength of HB or higher . That is, the rust preventive coating composition and the rust preventive method for a substrate of the present invention are represented by the general formula R ³ Si (OH) ₃ (wherein R ³ has 1 carbon atom ).
A monovalent group selected from an alkyl group and an aryl group
An organosilanetriol represented by
Condensate the partial hydrolyzate as the main component
As a rust preventive composition for a base material made of an inorganic material that is brought into contact with an aluminum material or a metal material by blending a specific organothiol compound into a silicone having a viscosity of 5 to 10000 cP It is characterized by being used.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The coating agent of the present invention contains, as a main component, a mixture of silicone and an organothiol compound and, if necessary, further contains a solvent and a curing catalyst. The silicone (A) used in the present invention is obtained by condensing an organosilanetriol represented by R ³ Si (OH) ₃ or a partial hydrolyzate thereof as a main component and condensing the same. here,
R ³ represents a monovalent group selected from the group consisting of an alkyl group having 1 to ³ carbon atoms and an aryl group, and examples of the alkyl group having 1 to ³ carbon atoms include a methyl group, an ethyl group and a propyl group, and an aryl group. Examples thereof include a phenyl group. Organosilanetriols are obtained by hydrolyzing the corresponding hydrolyzable silanes, for example of the formula R ³ Si (O
It can be obtained by hydrolyzing an organotrialkoxysilane represented by R ⁴ ) ₃ (wherein R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms) in the presence of a catalyst. Here, examples of R ⁴ include a methyl group, an ethyl group, a propyl group, and a butyl group. A hydrolyzable silane having a ketoxime group other than the alkoxy group, an acyloxy group, an amino group, an aminoxy group, an alkenyloxy group, an amide group, a chlorine atom or the like as a hydrolyzable group can also be used, but is easy to handle. Therefore, those having an alkoxy group as a hydrolyzable group are preferable. Examples of hydrolysis catalysts that can be used include acetic anhydride, glacial acetic acid, propionic acid, citric acid, benzoic acid, formic acid, oxalic acid, and other organic acids; aluminum chelate compounds such as aluminum alkyl acetates; tetrachlorosilane, methyltrichlorosilane. , Chlorosilanes such as dimethyldichlorosilane;
Examples thereof include inorganic alkaline compounds such as ammonia water; organic alkaline compounds such as ethylenediamine; amino group-containing organosilicon compounds such as γ-aminopropyltrimethoxysilane. Of these, chlorosilane is preferably used because it serves both as a silicone raw material and a hydrolysis catalyst. Of these, methyltrichlorosilane and dimethyldichlorosilane are preferable. In addition to these, R ⁵ ₂ SiX ₂ , R ⁶ ₃ SiX, SiX ₄ (wherein R ⁵ and R ⁶ are the above R ²
A silane represented by the same substituent as above, and X represents the same or different hydrolyzable groups or hydroxyl groups) may be used. Especially because of excellent durability of the protective coating, R ⁵ ₂ S
The use of iX ₂ is preferred. In this case, the molar ratio of organosilanetriol / R ⁵ ₂ SiX ₂ is 0.2 because of the durability of the coating.
/0.8 or more is preferable, and from the workability as a coating agent, 0.6 / 0.4 to 0.8 to 0.2 is particularly preferable.

The organothiol compound (B) used in the present invention is represented by the general formula R ¹ SH (wherein R ¹ represents a saturated or unsaturated monovalent hydrocarbon group having 8 to 24 carbon atoms), or It is a compound represented by the general formula HSR ² SH (wherein R ² represents a saturated or unsaturated divalent hydrocarbon group having 3 to 16 carbon atoms).
The organothiol compound (organomercaptan) represented by the general formula R ¹ SH has 8 to 24 carbon atoms, preferably 10 to 22 carbon atoms. If the carbon number is less than 8, the vapor pressure is low, and it is apt to volatilize at room temperature, so that it is unsuitable, and the odor is strong and the operator is uncomfortable. Also,
A coating agent composition using an organomercaptan having more than 24 carbon atoms is not suitable because it tends to have poor dispersibility. Examples of the organomercaptan satisfying these conditions are decyl mercaptan, dodecyl mercaptan, n-tetradecyl mercaptan, tert-tetradecyl mercaptan, hexadecyl mercaptan,
Octadecyl mercaptan, isooctadecyl mercaptan, cis-9-octadecenyl mercaptan, eicosyl mercaptan, docosyl mercaptan and the like can be mentioned. Further, although organomercaptans having an odd number of carbon atoms are also exemplified, they are difficult to obtain industrially. The organodithiol represented by the general formula HSR ² SH has 3 carbon atoms.
It is within the above range. When the carbon number is less than 3, it is not suitable because the vapor pressure is low and it is likely to volatilize at room temperature.
Particularly, those having 6 or more carbon atoms are preferable. Examples of these organodithiols include 1,3-trimethylenedithiol, 1,4-tetramethylenedithiol, 1,5-
Pentamethylenedithiol, 1,6-hexamethylenedithiol, 1,8-octamethylenedithiol, 1,10-decamethylenedithiol, 1,12-dodecamethylenedithiol, 1,14-tetradecamethylenedithiol and the like can be mentioned. Such component (B) (organothiol compound)
The compounding amount is 0.01 to 3 parts by weight, preferably 0.1 to 1 part by weight, relative to 100 parts by weight of the component (A) (silicone). If the amount is less than 0.01 part by weight, the effect of the composition is not recognized,
Even if it exceeds 3 parts by weight, no significant improvement in the rust preventive effect can be observed depending on the blending ratio. Also, because it has an unpleasant odor,
Inappropriate.

When a coating film is desired to be formed with the coating agent of the present invention, a curing catalyst (C) can be further used. As such a catalyst, a general curing catalyst used in condensation-curable silicone compositions can be used. Organic amines such as triethanolamine; carboxylic acid metal salts such as tin octylate and zinc octylate; dibutyltin dilaurate and dibutyltin. Organotin compounds such as octoate;
Titanium esters such as tetrabutyl titanate and tetrapropyl titanate; quaternary ammonium compounds such as quaternary ammonium carboxylate; γ-aminopropyltriethoxysilane, N- (β-aminoethyl)
Examples include amine-based silane coupling agents such as -γ-aminopropylmethyldiethoxysilane, and dibutyltin dilaurate and tetrabutyl titanate are preferable because of good storage stability. Two or more kinds of these catalysts may be used in combination, and the amine-based silane coupling agent is also effective in improving the adhesion to the substrate, and therefore it is preferably used in combination with another catalyst. The amount of the catalyst blended depends on the curing speed of the coating agent and the pot life.
0.01 to 10 parts by weight is preferred with respect to 0 parts by weight, especially 0.02
˜2 parts by weight is preferred.

A solvent (D) can be further used in the coating agent of the present invention. The solvent component is not particularly limited as long as it dissolves and disperses the above silicone, and alcohols such as methanol, ethanol and isopropanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, tetrahydrofuran, dioxane and the like. Ether alcohols and ethers; ketones such as acetone, methyl ethyl ketone, diethyl ketone; esters such as methyl acetate, ethyl acetate, n-butyl acetate; n-hexane, gasoline, rubber volatile oil, mineral spirits,
Examples thereof include aliphatic hydrocarbons such as kerosene; aromatic hydrocarbons such as benzene, toluene and xylene; silicone oils such as linear dimethyl siloxane and cyclic dimethyl siloxane.

Of these, it is preferable to use a low molecular weight cyclic dimethyl siloxane because it has good penetrability and coatability to the substrate and has a low odor. When early morning drying is required, alcohol such as methanol, ethanol and isopropanol is preferably contained, and ethanol and isopropanol are particularly preferable. These solvents may be used as a mixture of two or more kinds. When the solvent component is used, it is generally in the range of 50 to 2000 parts by weight with respect to 100 parts by weight of the above silicone.
~ 1000 parts by weight is preferred.

In the coating composition of the present invention,
The degree of polymerization of silicone, which is a hydrolyzate, is not particularly limited, but the viscosity is preferably 5 to 10000 cP, and particularly preferably 10 because the coating property on the substrate is good and a flat film can be formed. ~ 500cP.

[0011]

The occurrence of rust leads to a change in the appearance of the base material, a decrease in the strength of the base material, and a decrease in the commercial value. According to the method of the present invention, the surface of a metal material typified by aluminum or the like, and excellent rust-prevention effect, water resistance and protection effect are imparted to an inorganic material such as stone or mortar used in contact with the metal material. By doing so, it is possible to prevent a change in the appearance of the base material and a decrease in the strength of the base material and maintain the commercial value for a long period of time, so that the practical value is extremely large. Moreover, since it can be easily applied even at room temperature and high temperature, it can be applied to a base material having no heat resistance and can be applied at a work site where heat is not applied. Therefore, its industrial and industrial value is extremely high.

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following examples. In the examples, "part" is "part by weight".
"%" Means "% by weight". Also, the viscosity is 25 ℃
Indicates the value of. The following ingredients were used in the examples: Synthesis Example 1 Methyltrimethoxysilane 1360 was placed in a flask equipped with a stirrer, a heating jacket, a reflux condenser and a dropping funnel.
g (10 mol), 200 g of methanol and methyltrichlorosilane were charged so that the hydrochloric acid content was 50 ppm, and 171 g (9.5 mol) of water was gradually added dropwise with a dropping funnel while stirring. The hydrolysis and condensation reactions were carried out by holding at the reflux temperature (about 68 to 72 ° C.) for 4 hours. After distilling off volatile matter under normal pressure and 100 ° C, gradually reduce pressure to 40 mmHg and 150 ° C.
Further, the volatile matter was distilled off under reduced pressure under the conditions described above to obtain 630 g (A-1) of silicone having a viscosity of 20 cP.

Synthesis Example 2 Alkoxysilane and acetic acid in the amounts shown in Table 1 were placed in a flask equipped with a stirrer, a heating jacket, a reflux condenser, a moisture meter and a dropping funnel, and gradually heated while stirring. When the liquid temperature reached 80 ° C, the amount of water shown in Table 1 was gradually added dropwise. The alcohol produced by the reaction was kept at a reflux temperature (about 78 to 83 ° C.) for 4 hours to carry out hydrolysis and condensation reactions. Then, the mixture is heated and stirred while removing the distilled alcohol with a moisture meter, and when the distillation of the alcohol stops and the temperature of the reaction solution rises, the heating is stopped, the temperature is returned to room temperature, and the silicone having the viscosity shown in Table 1 is used. (A-2, A-3 and A-4) were obtained.

Synthesis Example 3 Methyltrimethoxysilane 952 was placed in a flask equipped with a stirrer, a heating jacket, a reflux condenser and a dropping funnel.
g (7 mol), phenyltrimethoxysilane 198 g (1 mol),
Dimethyldichlorosilane 516g (4mol) and toluene 15
Then, 234 g (13 mol) of water was gradually added dropwise with stirring. After the completion of dropping, the mixture was refluxed at a temperature of about 110 ° C. and heated and stirred for 1 hour. The reaction solution was gradually cooled to room temperature, transferred to a separating funnel and allowed to stand to separate an organic layer and an aqueous layer, and then the lower aqueous layer was removed to obtain a silicone solution. Saturated saline was added to this organic layer, and the mixture was stirred well and then allowed to stand to separate the aqueous layer. After repeating this salting out operation twice,
Water was added and the organic layer was washed twice with the same operation. This organic layer was placed in a flask equipped with a stirrer, a heating jacket, and a moisture meter, and volatile components were distilled off under reduced pressure at 30 mmHg and 80 ° C. for 3 hours to obtain 860 g of silicone having a viscosity of 100 cP (A
-5) was obtained.

Reference Example 1 Carnauba wax 50 parts, liquid paraffin 25 parts, polyoxyethylene (10) stearate 9 parts, polyoxyethylene (40) stearate 9 parts, polyoxyethylene (10) octyl phenyl ether 12 parts After gradually heating and dissolving, the mixture is heated and stirred while maintaining it at 90 ° C, then 380 parts of water heated to 90 ° C is gradually added and stirred for 1 hour, and then cooled and stirred, and cooled to 25 ° C. Then, an emulsified composition (B-1) was obtained. Reference Example 2 An aqueous dispersion (B-2) containing 33% liquid paraffin and 12% propylene glycol monostearate was prepared in the same manner as in Reference Example 1. Reference Example 3 Carnauba wax 20%, glycerin monolaurate 5% and polyethylene glycol 10 as in Reference Example 1.
% To prepare an aqueous dispersion (B-3). Reference Example 4 100 parts of drying oil is dissolved in 700 parts of mineral spirits,
A solution (B-4) was prepared.

[0016]

[Table 1]

Examples 1 to 9 and Comparative Examples 1 to 8 Coating agents were prepared with the composition shown in Tables 2 and 3,
The rust resistance, weather resistance, coating strength, and adhesion were evaluated by the following methods. The results are shown in Tables 2 and 3. Preparation of test piece 1 A 15 × 15 cm aluminum plate was subjected to flow coating and air-dried for 1 day to form a film, thereby forming a test piece. Preparation of test piece 2 A 15 × 15 cm aluminum plate was subjected to flow coating and dried at 60 ° C. for 30 minutes to form a film, thus preparing a test piece. Preparation of test piece 3 A 15 × 15 × 2 cm mortar plate was dipped in the coating agent for 1 minute, taken out, and air-dried for 1 day to form a film, thereby forming a test piece.

[Rustproofness] Regarding the test pieces 1 and 2, the test piece was put in a glass petri dish and 50 g of 5% NaCl aqueous solution was added.
After spraying, sealing, and leaving at 35 ° C. for 2 days, generation of rust was visually observed and evaluated according to the following 4 grades. ◎: No rust generation ○: White discoloration on the surface (less than 5% of the substrate surface) △: White or brown discoloration on the surface (50 on the substrate surface)
%) X: Rust occurred For test piece 3, 15 × 15 × 1 in the glass petri dish.
Put a steel plate of cm, put the test piece 3 on it, spray 50 g of 5% NaCl aqueous solution to make a tight seal, leave it for 2 days at 35 ° C, and visually observe the occurrence of rust. It was evaluated by. ◎: No rust generation ○: White discoloration on the surface (less than 5% of the substrate surface) △: White or brown discoloration on the surface (50 on the substrate surface)
X: Rust is generated [Weather resistance] Adhesiveness After exposure for 1000 hours using a sunshine weatherometer, the appearance was visually observed and evaluated according to the following four grades. ⊚: No rusting, good transparency of the coating ○: White discoloration on the surface (less than 5% of the substrate surface) Good transparency of the coating Δ: White or brown discoloration on the surface (substrate surface) Of 50
Less than%) The transparency of the coating is slightly poor. ×: Rust is generated, and the transparency of the coating is also poor. [Coating strength] For test pieces 1 and 2, pencil hardness test method (JIS
K5400) was evaluated. [Adhesion] The test pieces 1 and 2 were evaluated according to the cross-cut peeling test method. The adhesion to the base material was examined by a cross-cut cellophane adhesive tape (cellophane) peeling test, and it was shown by the number of cross-cuts remaining in the base material out of 100 cross-cuts.

[0019]

[Table 2]

[0020]

[Table 3]

As shown in Tables 2 and 3, the coating agent compositions used in the method of the present invention all showed good results with respect to various properties such as rust resistance, water resistance and weather resistance.
On the other hand, the coating agent compositions of Comparative Examples were inferior in rust resistance and water resistance, and were not sufficiently satisfactory in weather resistance.

Example 10 In place of the aluminum plate, a pentite plate and an oil plate were used, and the coating agents of Examples 1 and 4 were used and evaluated in the same manner. Good results were obtained with respect to rust resistance, weather resistance, coating strength and adhesion.

Continuation of the front page (56) Reference JP-A-56-157495 (JP, A) JP-A-61-218660 (JP, A) JP-A-60-199075 (JP, A) JP-A-62-57470 (JP , A) JP-A-6-322316 (JP, A) JP-A-8-27424 (JP, A) JP-A-4-164995 (JP, A) JP-A-2-129388 (JP, A) JP-A 59-215490 (JP, A) JP 62-197369 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 183/00-183/16 C09D 5/08 C23C 30 / 00 C23F 11/16

Claims (2)

(57) [Claims] 1. A general formula R ³ Si (OH) ₃ (wherein R ³ is a carbon number
Monovalent selected from alkyl groups of 1 to 3 and aryl groups
Of the organosilanetriol represented by
Is a partial hydrolyzate of which the main component is condensed
Obtained by adding a silicone having a viscosity of 5 to 10000 cP to the general formula R ¹ SH (wherein R ¹ is a saturated or unsaturated monovalent hydrocarbon group having 8 to 24 carbon atoms). , And the general formula
Addition of an organothiol compound selected from the group consisting of compounds represented by HSR ² SH (wherein R ² represents a saturated or unsaturated divalent hydrocarbon group having 3 to 16 carbon atoms) According to the pencil hardness test method (JIS K5400)
A coating agent composition for rust prevention on a substrate made of an inorganic material that comes into contact with an aluminum material or a metal material , the coating strength of which is HB or more as measured by . 2. A method of rust-preventing a substrate made of an inorganic material which comes into contact with an aluminum material or a metal material, which comprises coating the rust-preventive coating composition according to claim 1 on the substrate.