JPH03242268A - Method for repairing surface of inorganic hardened body - Google Patents

Abstract

PURPOSE:To eliminate the need for baking in coating and adhesion by applying a primer composition having a specified composition on the part to be repaired on the surface of an inorg. hardened body having a silicon alkoxide-based coating layer and then applying a cold-setting coating. CONSTITUTION:One hundred pts.wt. of an epoxy compd. having >=2 epoxy groups in the molecule, 10-500 pts.wt. of an organosilicon compd. having >=1 mercapto group and >=2 alkoxy groups in the molecule, 5-200 pts.wt. of a titanic ester shown by Ti(OR)4 (R is a 1-6C monovalent hydrocarbonic group) and an org. solvent are mixed to prepare a primer composition. The composition is applied on the par to be repaired of an inorg. hardened body having a silicon alkoxide-based coating layer on this surface, and then a cold-setting coating is applied to repair the surface of the body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for repairing the surface of an inorganic cured product having a silicon alkoxide coating layer.

[Conventional technology]

The inorganic cured product is a material with excellent weather resistance, heat resistance, and durability, but if its surface is left uncoated, moisture will enter and exit, causing problems such as neutralization and efflorescence. On the other hand, it also has the disadvantage of poor stain resistance and acid resistance.

In order to solve these problems, silicon alkoxide coatings have recently been used. These coating layers have excellent weather resistance, heat resistance, and durability, so inorganic cured products coated with a silicon alkoxide coating that can protect the inorganic cured product for a long period of time have excellent weather resistance and durability. Because of its excellent properties, it is mainly used for purposes such as exterior wall materials for buildings. Therefore, cutting and nailing may be performed at the construction site, and damage may occur during transportation. Therefore, it is necessary to repair these areas.

[Problem to be solved by the invention]

This repair can be done using a similar silicon alkoxide coating, but this type of coating
Since baking requires treatment, it cannot be used as a repair method at construction sites.

The inventors first considered using a room temperature curing type paint such as a fluorine-based paint or a modified silicone-based paint as a repair coating agent. However, this type of paint has the problem that it does not adhere to the silicon alkoxide coating surface, or that it is difficult to adhere to it in a short time even when treated with existing primers.

In view of the above circumstances, it is an object of the present invention to provide a repair method capable of adhering a cold-curable paint to a portion of the surface of an inorganic cured body that requires repair.

[Means to solve the problem]

In order to solve the above problems, the method for repairing the surface of an inorganic cured product according to the present invention includes applying the following ingredients (a), (b), and (c) to the areas that require repair on the surface of the inorganic cured product in advance.
) and (d) are applied, and then a cold-curable paint is applied.

(100 parts by weight of an epoxy compound having two or more epoxy groups in the al molecule (hereinafter, "parts by weight" is simply referred to as "parts").

(b) Organosilicon compound having one or more mercapto groups and two or more alkoxy groups in the molecule 10-500
Department.

(c1 general formula Ti(OR)4 (wherein, R has 1 to 6 carbon atoms)
titanate ester represented by monovalent hydrocarbon group)
200 copies.

(dl organic solvent.

There are no particular restrictions on the areas that require repair, but for example, areas where the silicon alkoxide coating layer has been scratched or chipped during transportation or installation of the inorganic cured product, and This also includes places where you are trying to change something. In addition, areas that require repair are not limited to areas where the inorganic cured product is exposed, but also include areas where silicon alkoxide coating layers, repair materials applied to damaged parts of the inorganic cured product, joints, etc. are exposed. .

Repair materials include, for example, putty, silicone caulking agent,
Color nails, etc. Colored nails are nails coated with acrylic paint for coloring.

The epoxy compound (or epoxy resin) of component (a) used in this invention needs to have two or more epoxy groups in the molecule. If the number of epoxy groups is less than two, it is not preferable because the effect of adhering a paint such as a fluorine paint to a silicon alkoxide coating surface is not exhibited. The epoxy compounds include bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, hydrogenated bisphenol A
In addition to diglycidyl ether, sorbitol diglycidyl ether, polyglycerol diglycidyl ether, resorcin diglycidyl ether, etc., unsaturated groups of hydrocarbons having multiple unsaturated bonds in the molecule are epoxidized by the action of peracetic acid, etc. Examples are given below. Among these, the last example is preferable because it provides particularly good adhesion, and among them, the number of carbon atoms constituting it is 4.
~30 are particularly recommended for similar reasons. The main function of this (al component) is to make the film formed by drying and curing of the primer composition tough, and to provide adhesion to the primer film of room-temperature curing paints such as fluorine-based paints.

The organosilicon compound containing one or more mercapto groups and two or more alkoxy groups in the molecule of the above-mentioned To) component used in this invention is essential in order to obtain adhesion to silicon alkoxide coating surfaces, etc. It is a component of The component (bl) has excellent adhesive properties because it has a mercapto group, and if it does not have a mercapto group, the adhesive effect will be lost.

The mercapto group is, for example, a mercaptoalkyl group (here, the alkyl group has, for example, 1 to 6 carbon atoms). In addition, the component (bl has an alkoxy group of 2
A film is formed when the organosilicon compound has more than one alkoxy group, but if it has only one alkoxy group or no alkoxy group, a film cannot be formed. OCH! )3, HS (c
Hz S i (OC2H5)-1H3(cH=
S' (OCH-)s, H3 (cHz
S i (OC2Hs)! , H3(cH-S i
Examples include silanes such as (cH-)(OCH-)z and their hydrolyzed condensates -0 These may be used alone or in combination of two or more types. Component (b)
The blending amount of the organosilicon compound is 10 to 500 parts per 100 parts of the component (al).
If the adhesive strength is less than 500
It is undesirable to exceed 100 mm because the strength of the primer coating decreases and adhesive strength is lost.

Component (a) and component ('b) may be mixed alone, or they may be reacted in advance, i.e., (a).
A mercapto group of the (bl component) may be added to the epoxy group of the component ().If components (a) and fb) are reacted in advance in this way, the adhesive effect will be enhanced.

The titanate ester represented by the general formula of the c1 component (Ti (OR)4) acts as a hydrolysis catalyst for the alkoxy group of the bl component, and is used to quickly form a tough primer film after painting. For the purpose of obtaining the catalytic effect, the organic group R of these titanate esters is preferably the same or different monovalent hydrocarbon group having 1 to 6 carbon atoms; More preferably, it is an alkyl group of 6.If the hydrocarbon group has 7 or more carbon atoms, the activity as a catalyst may decrease.The amount of component (c) used is 100 parts of component (a). If the amount of component (c) is less than 5 parts, the curing speed of the primer film will be slow and you will have to wait for a long time until room temperature curing paints such as fluorine paints can be applied. On the other hand, if it exceeds 200 parts, the primer coating becomes brittle and the adhesive strength decreases, which is not preferable.

(The organic solvent of dl is used for the purpose of facilitating the coating work of the primer composition.These organic solvents include:
Examples include aromatic hydrocarbons such as toluene and xylene, carboxylic acid esters such as ethyl acetate and butyl acetate, ketones such as acetone and methyl ethyl ketone, and ethers such as diethyl ether and tetrahydrofuran.

These solvents may be used alone or in combination. The usage ratio of (d) is not particularly limited and may be set appropriately since performance is guaranteed even in a fairly wide range.

Furthermore, the primer composition used in the repair method according to the present invention includes alkoxysilanes such as methyl silicate, ethyl silicate, methyltrimethoxysilane, methyltriethoxydisilane, dimethyldimethoxysilane, and dimethyljethoxysilane, and titanium oxide. , carbon blank, pigments such as iron oxide, and other additives can be added.

The top coat paint for the above primer composition is a room temperature curing type such as a commercially available fluorine-based room temperature curing paint, a modified silicone room temperature curing paint, an inorganic paint, or an acrylic urethane type commercially available room temperature curing paint. Paints may be used, but are not limited to these. Preferably, the material has excellent weather resistance.

In this invention, a repair material is applied as necessary to the surface of an inorganic cured body having a silicon alkoxide coating layer, and a primer composition containing the above (a) to (dl as essential components) is first applied. Then, it is completed by applying a room temperature curing paint such as a fluorine-based room temperature drying paint.The method for applying the primer composition and the room temperature curing paint is not particularly limited, and any suitable method may be used. The coating thickness (or coating thickness) may also be set appropriately.

The silicon alkoxide coating layer of an inorganic cured product having a silicon alkoxide coating layer that is commonly used in this invention is, for example, the following general formula; " is an alkyl group having 1 to 4 carbon atoms, and n is a number of 0.1 or 2." It is formed from a coating material whose main component is a silicon compound and/or a partial hydrolyzate thereof.

This coating material may contain silica sol as other components, and may also contain colorants, fillers, surfactants, thickeners, anti-aging agents, etc. Catalysts such as inorganic acids, organic acids, quaternary ammonium salts, amine salts, or organic tin compounds are added to these coating materials, and the coating materials are coated on the inorganic cured body and cured by heating.

The inorganic hardened body is used, for example, as an exterior wall material for buildings, and is manufactured by an appropriate method from raw materials such as cement, silica powder, pulp, asbestos, and synthetic fibers. The above-mentioned primer composition is applied to the places where the silicon alkoxide coating layer on the surface of the inorganic cured product is scratched, chipped, etc., and then a room temperature curable paint is applied. This will allow the repair to be carried out.

[For production]

Since the primer composition containing the above-mentioned specific components (a), (b), (c1 and (dl) was applied before the room temperature curing paint was applied, the silicon alkoxide coating surface of the same paint Good adhesion.

The paint cures at room temperature, so no baking process is required to form a film.

The main function of component (a) is to make the film formed by drying and curing the primer composition tough, and to provide adhesion to the primer film of paints such as fluorine-based paints. Component (b) is an essential component in order to obtain adhesion to the silicon alkoxide coating surface. Component (c) acts as a hydrolysis catalyst for the alkoxy group of component (bl), and is used to form a tough primer film immediately after application.Component (dl) This is to make it easier.

〔Example〕

Specific examples and comparative examples of the present invention are shown below, but the present invention is not limited to the following examples. In addition,"%
” represents “% by weight”.

Ilkoxy Coating's (top coating liquid C-1) 100 parts of methyltrimethoxysilane, 20 parts of tetraethoxysilane, IPA silica sol (manufactured by Catalysts & Chemicals Industry Co., Ltd. 03)
CAL1432, SiO□ content 30%), 105 parts of dimethyldimethoxysilane, and 100 parts of IPA were mixed. To this mixed solution, add 1 part of IN hydrochloric acid in a catalytic amount and 4 parts of water.
5 parts were added to prepare solution A. In addition, the formulation is at 25℃, 5
The mixture was stirred at 00 rpm for 30 minutes.

The prepared solution A was stored in a sealed state at 25°C for more than a week, and when used, 42 parts of water and 42 parts of water were added to 100 parts of solution A.
of IPA was added and stirred at 25° C. and 500 rpm for 10 minutes to obtain coating liquid CI.

(Top coat coating liquid C-2) 100 parts of methyltrimethoxysilane, 10 parts of tetraethoxysilane, TPA silica sol (same as above 03CAL143)
2) 110 parts of dimethyldimethoxysilane and 100 parts of IPA were mixed. A catalytic amount of 0.85 parts of IN hydrochloric acid and 5 parts of water were added to this mixed solution in the same manner as in C-1 to prepare liquid A'.

The prepared A' solution is stored in the same manner as the above A' solution, and when used, 43 parts of water and 43 parts of IP are added to 100 parts of A' solution.
Add A and proceed as in C-1 below to prepare coating liquid C.
-2 was obtained.

(Undercoating liquid C-3) To 100 parts of liquid A' of coating liquid C-2, 7.5 parts of commercially available titanium oxide, 0.3 parts of fine powder silica (Aerosil R972 manufactured by Nippon Aerosil @) and toluene-IPA were added. 10% ethyl cellulose diluted with mixed solution 2.5
part was added. This is done using a dispersion machine.
Glass peas were added to the container and dispersed at 2000 rprrl for 15 minutes, and the resulting solution A'' was stored at 25° C. for 3 days with a tightly stopper.

When using, add 27 parts of water and 2 parts of IPA to 00 parts of A″″ liquid.
7 parts and a catalytic amount of IN hydrochloric acid of 0.2 parts, and in the same manner as above, coating liquid C-3 was obtained. Epoxy compound 10 obtained by epoxidizing a hydrocarbon mixture having multiple bonds with peracetic acid
0 parts, 2 γ-mercaptopropyltrimethoxysilane
00 parts were added thereto, and the mixture was heated and stirred at 80° C. for 8 hours under a nitrogen atmosphere. After cooling to room temperature, 100 parts of tetrabutyl titanate and 500 parts of toluene were added and stirred to obtain primer (P-1).

(Primer P-2) 300 parts of γ-mercaptopropyltriethoxysilane, 100 parts of tetrabutyl titanate, 100 parts of xylene, and 100 parts of tetramethoxysilane were added to 100 parts of bisphenol A diglycidyl ether having a molecular weight of about 400, and the mixture was stirred. , primer (P-2) was obtained.

(Primer P-3) 100 parts of T-mercaptopropyltriethoxysilane was added to 100 parts of the same epoxy compound used in preparing Primer P-1, and the mixture was heated and stirred at 80°C for 8 hours in a nitrogen atmosphere. . Then, after cooling to room temperature, 75 parts of tetraethyl titanate, 700 parts of normal hexane, and 100 parts of methyltrimethoxysilane were added and stirred to obtain Primer P-3.

(Primer P-4) 100 parts of hydrogenated bisphenol A diglycidyl ether having a molecular weight of about 600, 400 parts of γ-mercaptopropyltrimethoxysilane, 100 parts of tetrabutyl titanate,
100 parts of dimethyldimethoxysilane and 80 parts of xylene
1 part and stirred to obtain Primer P-4.

(Inorganic hardened body - 1) Raw materials consisting of cement, silica powder, pulp, asbestos and polypropylene fibers are mixed with water and a thickener, extruded and then cured in an autoclave to form an inorganic hardened body - I got 1.

(Inorganic hardened body-2) Raw materials mainly consisting of blast furnace cement, silica sand, pulp, asbestos, and vinylon fibers were formed into a slurry, press-molded, and steam-cured to obtain inorganic hardened body-2.

Examples 1 to 24 and Comparative Examples 1 to 6 Brimer (XC99-8024) manufactured by Toshiba Silicone ■ was applied to inorganic cured body-1 and inorganic cured body-2 to a film thickness of 10 μl, and the mixture was heated at 60°C for 1 hour. After drying, apply coating liquid C-3 to a film thickness of 20. n, and baked at 150°C for about 1 hour, then coated coating liquids (,-1 and (, -2) to a film thickness of 10 m as topcoats, baked in the same way, and baked at 150°C for about 1 hour. An inorganic cured body having an alkoxide coating layer was obtained.

Primer P having the composition shown in Table 1 was applied to the surface of the silicon alkoxide coating layer of the inorganic cured product thus obtained.
-1 to P-4 were applied using a paint brush and dried for 30 minutes at room temperature. Next, the fluorine-based cold-curing paint shown in Table 1 was applied using a paint brush, and dried and cured at room temperature for 7 days to obtain test specimens T-1 to T-30.

Adhesion and frost damage resistance tests were conducted using these specimens. Adhesion was determined by immersing the sample in warm water at 60° C. for 10 days, then performing a peel test using an adhesive tape according to the base grain test method, and observing the number of peeled locations. Freeze resistance is A
The properties of the coating film after 200 cycles were observed according to the STM A method. These results are also shown in Table 1. Note that Comparative Examples 1 to 6 are comparative examples that do not use the primer used in the present invention.

Examples 25 to 48 and Comparative Examples 7 to 12 - The above Examples 1 to 24 and Comparative Examples 1 to 6 were applied to the inorganic cured bodies shown in Table 2.
A silicon alkoxide coating layer was formed by processing in exactly the same manner as above.

After reinforcing these inorganic cured bodies having a silicon alkoxide coating layer with putty, silicone caulking agent and colored nails, the putty, silicone caulking agent, colored nails, the alkoxide surface and the exposed surface of the inorganic cured bodies are covered, Films were formed in exactly the same manner as in Examples 1 to 24 and Comparative Examples 1 to 6 using the primer compositions and fluorine-based room temperature curing paints shown in Table 2, and test specimens T-31 to T-60 were formed. Obtained.

Using these specimens, adhesion and frost damage resistance tests were conducted in the same manner as above, and the results are shown in Table 2.

As shown in Tables 1 and 2, in the Examples, both adhesion and frost damage resistance were good, but in the Comparative Examples, these properties were poor.

〔Effect of the invention〕

As described above, in the method for repairing the surface of an inorganic cured product according to the present invention, the above-mentioned specific components (a), (b), (c1
Since the primer composition consisting of (d) and (d) is applied beforehand and the room temperature curable paint is applied, the room temperature curable paint can be adhered to the portions of the surface of the inorganic cured product that require repair. Further, when bonding in this manner, no baking treatment is required.

According to this invention, adhesion to repair materials such as putty, silicone caulking agent, and colored nails used for repair is also good.

Claims (1)

[Scope of Claims] 1. A primer composition consisting of the following components (a), (b), (c) and (d) is applied in advance to areas in need of repair on the surface of an inorganic cured body having a silicon alkoxide coating layer on the surface. A method of repairing the surface of an inorganic cured material by coating it with a material and then applying a room temperature curing paint. (a) 100 parts by weight of an epoxy compound having two or more epoxy groups in the molecule. (b) Organosilicon compound having one or more mercapto groups and two or more alkoxy groups in the molecule 10-500
Weight part. (c) General formula Ti(OR)_4 (in the formula, R has 1 to 1 carbon atoms
Titanate ester 5 represented by monovalent hydrocarbon group 6)
~200 parts by weight. (d) Organic solvent. 2. The method for repairing the surface of an inorganic cured body according to claim 1, wherein the repair material is applied to the area in need of repair on the surface of the inorganic cured body, and then the primer composition is applied.