JPH0813345B2 - Method for repairing surface of inorganic cured body - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for repairing the surface of a cured inorganic material having a silicon alkoxide coating layer.

[Conventional technology]

The inorganic cured material is a material having excellent weather resistance, heat resistance and durability, but if the surface thereof is not coated, water will flow in and out, causing problems such as neutralization and efflorescence generation. On the other hand, on the other hand, it has the drawback of being poor in stain resistance and acid resistance.

In order to solve these problems, those coated with silicon alkoxide have been used in recent years.
Since these coating layers have excellent weather resistance, heat resistance, and durability, they can protect the inorganic cured product for a long period of time.

BACKGROUND ART An inorganic cured product having a silicon alkoxide coating has excellent weather resistance and durability, and is therefore mainly used for outer wall materials of buildings and the like. Therefore, cutting and nailing may be performed at the construction site, and damage may occur during transportation. Therefore,
It is necessary to repair those parts.

[Problems to be Solved by the Invention]

This repair may be performed using the same silicon alkoxide coating agent, but this type of coating agent requires baking treatment, and therefore cannot be used in the repair direction at the construction site.

The inventors first examined the use of a room temperature curable coating material such as a fluorine-based or modified silicone-based coating as a repair coating agent. However, this kind of coating material has a problem that it does not adhere to the silicon alkoxide coating surface, or it is difficult to adhere to it in a short time even if it is treated with an existing primer.

In view of the above circumstances, it is an object of the present invention to provide a repair method capable of adhering a room temperature curable coating material to a repair required portion on the surface of an inorganic cured body.

[Means for solving the problem]

In order to solve the above-mentioned problems, the method for repairing the surface of an inorganic hardened body according to the present invention includes the following components (a), (b) and
The primer composition comprising (c) and (d) is applied and then the room temperature curable coating material is applied.

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

(B) Organosilicon compounds 10 to 500 having at least one mercapto group and at least two alkoxy groups in the molecule
Department.

(C) 5 to 20 titanic acid esters represented by the general formula Ti (OR) ₄ (wherein R is a monovalent hydrocarbon group having 1 to 6 carbon atoms).
0 copies.

(D) Organic solvent.

The above-mentioned repair-required place is not particularly limited, but for example, when carrying or constructing an inorganic hardened body, a place where a scratch or a chip of a coating film occurs in a silicon alkoxide coating layer, or a color. It also includes places where you are trying to change things such as. Further, the repair-required portion is not limited to a portion where the inorganic cured body is exposed, and includes a portion where a silicon alkoxide-based coating layer, a damaged portion of the inorganic cured body, a repair agent applied to a seam, or the like appears. . The repair material is, for example, putty, silicone caulking agent, color nail or the like. Color nails are nails coated with acrylic paint or the like for coloring.

The epoxy compound (or epoxy resin) of the component (a) used in this invention needs to have two or more epoxy groups in the molecule. When the number of epoxy groups is less than 2, the effect of adhering a paint such as a fluorine paint to a silicon alkoxide coating surface is not exhibited, which is not preferable. Examples of the epoxy compound include bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, sorbitol diglycidyl ether, polyglycerol diglycidyl ether, and resorcin diglycidyl ether. Examples thereof include those obtained by epoxidizing an unsaturated group of a hydrocarbon having an unsaturated bond with peracetic acid or the like. Of these, the last-exemplified ones are preferable because they give particularly good adhesiveness, and among them, those having 4 to 30 carbon atoms are particularly recommended for the same reason.
The main function of the component (a) is to make the coating film formed by drying and curing the primer composition tough, and to impart adhesiveness to the primer coating of a room temperature curing type coating material such as a fluorine-based coating material. .

In the molecule of the above-mentioned component (b) used in the present invention, 1
The organosilicon compound containing one or more mercapto groups and two or more alkoxy groups is an essential component for obtaining adhesiveness to a silicon alkoxide coating surface and the like. Since the component (b) has a mercapto group, it has excellent adhesiveness, and if it does not have a mercapto group, the adhesive effect is lost. The mercapto group is, for example, a mercaptoalkyl group (wherein the alkyl group has, for example, 1 carbon atom).
~ 6 things) and so on. A film is formed when the component (b) has two or more alkoxy groups, but if only one or no alkoxy group is present, the film is not formed. Examples of such an organosilicon compound include HS (CH ₂ ) ₃ Si (OCH ₃ ) ₃ , HS (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ , HS (CH ₂ ) ₂ Si (OCH ₃ ) ₃ , silanes such as HS (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ and HS (CH ₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂ and their hydrolyzed condensates. These may be used alone or in combination of two or more. The blending amount of the organosilicon compound as the component (b) is 10 to 500 parts with respect to 100 parts of the component (a). (B)
If the compounding amount is less than 10 parts, the adhesiveness will not be sufficiently exhibited, and conversely, if it exceeds 500 parts, the strength of the primer coating will decrease and the adhesive strength will be lost, such being undesirable.

The component (a) and the component (b) may be mixed individually, or they may be reacted in advance, that is, by adding the mercapto group of the component (b) to the epoxy group of the component (a) before use. Good. When the components (a) and (b) are reacted in advance in this way, the adhesive effect is further enhanced.

The titanic acid ester represented by the general formula: Ti (OR) ₄ of the component (c) acts as a hydrolysis catalyst of the alkoxy group of the component (b), and forms a tough primer film promptly after coating. It is for. The organic group R of these titanic acid esters is preferably a monovalent hydrocarbon group having 1 to 6 carbon atoms which is the same or different and is an alkyl group having 1 to 6 carbon atoms for the purpose of obtaining the above-mentioned catalytic effect. It is more preferable that there is. This is because if the hydrocarbon group has 7 or more carbon atoms, the activity as a catalyst may decrease. The amount of component (c) used is 5 to 200 parts per 100 parts of component (a). If the amount of component (c) is less than 5 parts, the curing speed of the primer coating will be slow and it will have to wait a long time until a room temperature curable paint such as a fluorine-based paint can be applied. Crossing,
It is not preferable because the primer coating becomes brittle and the adhesive strength is reduced.

The organic solvent (d) is used for the purpose of facilitating the coating operation of the primer composition. Examples of these organic solvents 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, ethers such as diethyl ether and tetrahydrofuran. It is illustrated. These solvents may be used alone or in combination of two or more. The use ratio of (d) is not particularly limited and may be appropriately set because the performance is guaranteed even in a considerably wide range.

Furthermore, the primer composition used in the repairing method according to the present invention includes methyl silicate, ethyl silicate,
Alkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane and dimethyldiethoxysilane, pigments such as titanium oxide, carbon black and iron oxide, and other additives can be added.

The overcoating material for the primer composition is a room temperature curing type such as a commercially available fluorine type room temperature curing type coating, a modified silicone type room temperature curing type coating, an inorganic coating, and an acrylic urethane type general commercially available room temperature curing type coating. Paints are used, but are not limited to these. Desirably, one having excellent weather resistance is preferable.

This invention applies a repair material to the surface of an inorganic cured product having a silicon alkoxide coating layer, where necessary for repair, and first, a primer composition containing the above-mentioned (a) to (d) as an essential component. It is completed by applying and then applying a room temperature curing type paint such as a fluorine type room temperature dry type paint. The method of applying the primer composition and the room temperature curable coating material is not particularly limited and may be any suitable method. The coating thickness (or coating thickness) may be set appropriately.

The silicon alkoxide coating layer of the inorganic cured body having the silicon alkoxide coating layer applied to the present invention is, for example, the following general formula: R ′ _n Si (OR ″) _4-n [wherein R ′ is A methyl group or an ethyl group, R ″ is an alkyl group having 1 to 4 carbon atoms, n is a number of 0, 1 or 2] and a coating material containing a silicon compound and / or a partial hydrolyzate thereof as a main component It is formed.
This coating material may contain silica gel as another component, and may be added with a coloring material, a filler, a surfactant, a thickener, an antiaging agent and the like. A catalyst such as an inorganic acid, an organic acid, a quaternary ammonium salt, an amine salt, or an organic tin compound is added to these coating materials, and the coating material is applied to an inorganic cured body and cured by heating.

The inorganic hardened material is used, for example, as an outer wall material of a building and the like, and is manufactured from a raw material such as cement, silica stone powder, pulp, asbestos and synthetic fiber by an appropriate method. The above primer composition is applied to the surface of the inorganic cured material on the surface of the silicon alkoxide-based coating layer where scratches or cracks have occurred, and then a room temperature curable coating material is applied. With this, repair is performed.

[Action]

The above specific components (a), (b), (c) and (d)
Since the primer composition containing is applied before the room temperature curable coating composition, the adhesive property of the coating composition to the silicon alkoxide coating surface is improved. Since the coating material is a room temperature curing type, it does not require a baking treatment for forming a coating film.

The main function of the component (a) is to make the coating film formed by drying and curing the primer composition tough, and to give the coating material such as a fluorine-based coating material adhesion to the primer coating film. The component (b) is an essential component for obtaining the adhesion to the silicon alkoxide coating surface. The component (c) acts as a hydrolysis catalyst for the alkoxy group of the component (b), and is for forming a tough primer film immediately after coating. The component (d) is for facilitating the coating operation of the primer composition.

〔Example〕

Specific examples and comparative examples of the present invention will be shown below, but the present invention is not limited to the following examples. In addition,
"%" Represents "% by weight".

Preparation of Silicon Alkoxide Coating Solution (Coating Solution C-1 for Topcoat) 100 parts of methyltrimethoxysilane, 20 parts of tetraethoxysilane, IPA silica sol (OSCAL manufactured by Catalysts & Chemicals Co., Ltd.)
1432, SiO ₂ content 30%) 105 parts, was mixed with 5 parts of IPA100 parts dimethyldimethoxysilane. To this mixed solution, 1 part of a catalytic amount of 1N hydrochloric acid and 4.5 parts of water were added to prepare a solution A. The blending was performed at 25 ° C. with stirring at 500 rpm for 30 minutes.

The prepared solution A is stored in a tightly closed state at 25 ° C for 1 week or more. When used, 42 parts of water and 42 parts of I are added to 100 parts of solution A.
PA was added and the mixture was stirred at 25 ° C. and 500 rpm for 10 minutes to obtain coating liquid C-1.

(Coating Liquid C-2 for Topcoat) 100 parts of methyltrimethoxysilane, 10 parts of tetraethoxysilane, 110 parts of IPA silica sol (same as above OSCAL1432), 20 parts of dimethyldimethoxysilane and 100 parts of IPA were mixed. To this mixed solution, a catalytic amount of 0.85 part of 1N hydrochloric acid and 5 parts of water were added in the same manner as in C-1, to prepare solution 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 IPA are added to 100 parts of the A'solution, and then the coating solution is prepared in the same manner as in C-1. C-2 was obtained.

(Coating liquid C-3 for undercoat) To 100 parts of A'solution of coating liquid C-2, 7.5 parts of commercially available titanium oxide, 0.3 parts of finely powdered silica (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.) and toluene-IPA mixed solution 2.5 parts of 10% ethyl cellulose diluted by was added. Using a disper (disperser), glass beads were added to the container and dispersed at 2000 rpm for 15 minutes, and the obtained A ″ solution was tightly sealed and stored at 25 ° C. for 3 days.

At the time of use, 27 parts of water, 27 parts of IPA and 0.2 part of a catalytic amount of 1N hydrochloric acid were added to 100 parts of the A ″ solution, and a coating solution C-3 was obtained in the same manner.

Preparation of Primer (Primer P-1) Epoxy compound obtained by epoxidizing a hydrocarbon mixture having unsaturated bonds (plurality) having 6 to 8 carbon atoms with peracetic acid 10.
In 0 parts, γ-mercaptopropyltrimethoxysilane 200
Parts were added, and the mixture was heated with stirring at 80 ° C. for 8 hours under a nitrogen atmosphere.
Then, after cooling to room temperature, tetrabutyl titanate 100
Parts and 500 parts of toluene were added and stirred to obtain a primer (P-1).

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

(Primer P-3) 100 parts of γ-mercaptopropyltriethoxysilane was added to 100 parts of the same epoxy compound used for 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 a primer P-3.

(Primer P-4) To 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 were added. Stir to obtain primer P-4.

Manufacture of inorganic hardened body (Inorganic hardened body-1) Water and a thickener are added to a raw material composed of cement, silica stone powder, pulp, asbestos and polypropylene fiber, and the mixture is extruded and then cured in an autoclave for inorganic hardening. Body-1 was obtained.

(Inorganic cured body-2) A raw material mainly composed of blast furnace cement, silica sand, pulp, asbestos and vinylon fibers was formed into a slurry, press-molded, and then steam-cured to obtain an inorganic cured body-2.

-Examples 1 to 24 and Comparative Examples 1 to 6-Inorganic cured body-1 and inorganic cured body-2 were coated with a primer (XC99-8024) manufactured by Toshiba Silicone Co., Ltd. to a film thickness of about 10
to a thickness of about 20 μm, and then coating solution C-3 is applied to a thickness of about 20 μm.
An inorganic cured product having a silicon alkoxide coating layer, which is baked at 150 ° C. for about 1 hour, and further coated with coating liquids C-1 and C-2 as a top coating liquid to a film thickness of about 10 μm. Got

Primers P-1 to P-4 having the compositions shown in Table 1 were applied to the surface of the silicon alkoxide coating layer of the thus obtained inorganic cured body using a paint brush, and dried at room temperature for 30 minutes. Then, the fluorine-based room temperature curable coating material shown in Table 1 was applied using a paint brush and dried and cured at room temperature for 7 days to obtain test pieces T-1 to T-30.

Adhesion and frost damage resistance were tested using these test bodies. Regarding the adhesion, after immersing in warm water at 60 ° C. for 10 days, a peeling test was performed by using a pressure sensitive adhesive tape by a cross-cut test method, and the number of peeled points was observed. Frost resistance is ASTM
According to method A, the properties of the coating film after 200 cycles were observed.
These results are also shown in Table 1. In addition, Comparative Examples 1 to 6
Is a comparative example in which the primer used in the present invention is not used.

-Examples 25 to 48 and Comparative Examples 7 to 12-The cured inorganic materials shown in Table 2 were treated in exactly the same manner as in Examples 1 to 24 and Comparative Examples 1 to 6 to form a silicon alkoxide coating layer. These, inorganic cured body having a silicon alkoxide coating layer, putty, after reinforcing with silicone caulking agent and color nail, putty, silicone caulking agent, color nail, so as to cover the alkoxide surface and the inorganic cured body exposed surface, Using the primer composition and the fluorine-based room temperature curing type coating material shown in Table 2, a coating film was formed in the same manner as in Examples 1 to 24 and Comparative Examples 1 to 6 to give test samples T-31 to T-60. Obtained.

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

As seen in Table 1 and Table 2, in the examples, both the adhesion and the frost damage resistance were good, but in the comparative examples, their properties were inferior.

〔The invention's effect〕

The method for repairing the surface of the inorganic cured body according to the present invention is
As described above, the specific components (a), (b), and
Since the primer composition comprising (c) and (d) is applied and then the room temperature curable coating material is applied, the room temperature curable coating material can be adhered to the surface of the inorganic cured body where repair is required. In addition, a baking process is not necessary when bonding in this way.

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

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08G 59/40 NJK 59/68 NKM C09D 163/00 PJZ PKB (72) Inventor Chiyuki Shimizu Tokyo 6-23-1, Roppongi, Minato-ku, Toshiba Silicon Co., Ltd. (72) Inventor Hisayuki Nagaoka 6-2-1, Roppongi, Minato-ku, Tokyo (56) References, Special Table 58-500752 (JP, A)

Claims (2)

[Claims] 1. The following components (a), (b), (c) and (d) are preliminarily provided on the surface of an inorganic cured body having a silicon alkoxide coating layer on the surface where repair is required.
A method for repairing the surface of an inorganic cured body, which comprises applying a primer composition comprising the composition and then applying a room temperature curable coating material. (A) 100 parts by weight of an epoxy compound having two or more epoxy groups in the molecule. (B) 10 to 500 parts by weight of an organosilicon compound having at least one mercapto group and at least two alkoxy groups in the molecule. (C) 5 to 20 titanic acid esters represented by the general formula Ti (OR) ₄ (wherein R is a monovalent hydrocarbon group having 1 to 6 carbon atoms).
0 parts by weight. (D) Organic solvent. 2. The primer composition is applied after a repair material is applied to a necessary repair portion on the surface of the inorganic cured body.
A method for repairing the surface of the inorganic cured body described.