JPH01219078A - Repairing process of asbestos slate - Google Patents

Abstract

PURPOSE:To improve strength, weather resistance, etc., of an asbestos slate by only coating, impregnating, or setting a compsn. without requiring removal of deteriorated part of the asbestos slate, nor requiring adjustment of mol.wt. of the compsn. nor solvent by applying a compsn. contg. a specified compd. as essential component to the surface of the asbestos slate. CONSTITUTION:A compsn. contg. a compd. expressed by formula I (wherein R is methyl) as essential component is coated on the surface of an asbestos slate. Another conventional (meth)acrylic ester may be used in combination in addition to the compd. expressed by formula I for the above described compsn. so far as no adverse influence is caused on the effect. Further, a setting agent, or if necessary, an accelerating agent or an additive, may be added.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for repairing 9-asbestos slate.

(Prior art) When the asbestos slate conventionally used for roof tiles etc. becomes obsolete, it is either replaced with a new asbestos slate, or the dirt, moss, etc. that have accumulated on the surface are removed by blowing high-pressure water. After application, aging areas are completely removed by brushing with a wire brush, etc.

A repair method is repainting. but.

The former replacement method requires a lot of labor and expense, and the latter repair method requires complete removal of contaminants, resulting in poor paint adhesion and premature peeling. i
Ta. Removal with high-pressure water or a wire brush causes a decrease in the strength of the asbestos slate. Furthermore, brushing the surface of aged asbestos slates causes asbestos powder, which is harmful to the human body, to float, creating safety and environmental problems.

As a solution to some of these problems, as shown in Japanese Patent Application Laid-Open No. 173462/1984, a polyisocyanate compound is applied to the surface of asbestos slate, impregnated and cured, and then a paint is applied. There is a repair method that is characterized by this.

(Problem to be Solved by the Invention) However, although the method shown in Japanese Patent Application Laid-Open No. 173462/1983 can restore the strength of asbestos slate and regenerate it into asbestos slate with excellent durability, it is difficult to obtain the above effects by using polyimide. The molecular weight range of cyanate compounds is limited,
There are also problems related to workability, such as the need to dissolve the polyisocyanate compound in a solvent to provide impregnating properties.

Sixth, there were problems such as the need to apply paint on the top layer to make it weather resistant.

The present invention solves all of the conventional problems listed above.2) Removal of aged parts of asbestos slate.

A composition containing the compound represented by general formula (1) is applied and impregnated without the need for molecular weight adjustment or solvents.

The present invention provides a method for repairing asbestos slate that can improve the strength, weather resistance, etc. of asbestos slate simply by curing it.

(Means for Solving the Problem) The present invention provides a composition containing as an essential component a compound represented by the general formula (I); (wherein R represents hydrogen or a methyl group) as an asbestos slate. This invention relates to a method for repairing asbestos slate, which is characterized by coating the surface of asbestos slate.

The compound represented by the general formula (1) is tetrahydrofurfuryl acrylate or tetrahydrofurfuryl methacrylate, and these may be used alone or in combination of two or more. Furthermore, it is also possible to use other known acrylic esters and methacrylic esters in combination to the extent that the effects of the present invention are not impaired.

In addition to the above, the composition used in the present invention contains a curing agent, and if necessary, additives and accelerators.

As the curing agent, a polymerization initiator such as an organic peroxide is used. Preferred organic peroxides include peroxides, hydroperoxides, etc. derived from hydrocarbons having 9, for example, about 3 to 18 carbon atoms, which are easily soluble in the above compounds. Specifically, t-butyl hydroperoxide, cumene hydroperoxide, methyl ethyl ketone hydroperoxide, diisopropylbenzene hydroperoxide.

il [hensoyl, t-butyl perbenzoate.

2+2-bis-(t-butylperoxy)-butane.

bis-(1-hydroxy-cyclohexyl)-phthane,
Bis-(1-hydroxy-cyclohexyl)-peroxide, t-butylperoxyisopropyl carbonate, and the like. These curing agents include compounds represented by general formula (I) or other acrylic esters thereof,
1% by volume of 2 to 6 volumes based on the total amount of methacrylic acid ester
It is preferable to use it for 3 to 5 volumes.

The accelerator used as necessary is one that accelerates the action of the curing agent. As a promoter.

Aromatic amines are used, specifically aniline,
N,N-dimethylaniline, N,N-diethylaniline, toluidine, N,N-dimethyl-p-toluidine, N,N-di(hydroxyethyl)toluidine, p-
Examples include dimethylaminobenzaldehyde. When using these accelerators.

For the compound represented by general formula (1) or it and other acrylic esters and methacrylic esters,
It is preferable to use 0 to 4 volumes, especially 1 to 3 volumes.

Benzoyl peroxide as curing agent, N, N- as accelerator
Particular preference is given to using dimethyl-p-toluidine.

Additives used as necessary further accelerate the action of the curing agent or the accelerator and promote oxidative curing.

Examples of additives include desiccant salts such as metal salts of naphthenic acid, fatty acids having up to 30 carbon atoms, and the like. Examples of metal components include calcium, M (If), zinc (I
f), manganese (If), manganese (■), lead (■)
, cobalt (■), iron (■), vanadium (■), zirconium (IV), etc., and examples of the acid component include.

Resin acids (i.e. rosin acids), tall oil fatty acids.

Linseed oil fatty acid, 2-ethylhexanoic acid.

Examples include lauric acid, parmitic acid, myristic acid, oleic acid, linoleic acid, lylinic acid, behenic acid, cerotic acid, heptanoic acid, apichenic acid, etc.These desiccant salts may also be used as a mixture. The additive may be added in an amount of 0 based on the total amount of the compound represented by formula (1) or this and other acrylic esters and methacrylic esters.
．． 1-2 volumes.

It is preferable to use KO13 to 1.0 volume.

The above-mentioned components are preferably mixed into a composition by a known method immediately before use, and then sprayed,...
It is applied to asbestos slate by coating, impregnated, and hardened. The amount to be applied is 0.4~0, s kg/m”
# Particularly preferably 0.5 to 0.6 kg/m''.

In the present invention, there is no need to spray high-pressure water or brush the aged asbestos slate before application, and it is sufficient to simply brush off the accumulated earth and sand with a broom or the like.

Mana9 The asbestos slate repaired according to the present invention has sufficient weather resistance and strength on its own, but in order to further improve its weather resistance and make it more beautiful, it is coated with acrylic room temperature drying paint.

Known paints such as acrylic urethane paint and natural asphalt aluminum paint can also be applied.

(Function) The compound represented by general 2m has a low viscosity, does not need to be dissolved in an ant solvent, has high impregnating properties, has high adhesion to asbestos slate, and has a high flash point. It has advantageous properties for use in slate repair methods.

(Example) Example 1 Contaminants such as earth and sand on a large corrugated asbestos slate roof that has been over 20 years old were removed using a paddle, and tetrahydrofurfuryl methacrylate was mixed with 4 volumes of cumene hydroperoxide, with an activity of 6%. Two volumes of cobalt naphthinate were mixed and stirred, and the resulting composition was spray applied in an amount of 0.6 kg/m''.

Three days later, adhesion and impact resistance tests were conducted.

Example 2 After applying Example 1, an acrylic air-drying paint (manufactured by Hitachi Kasei Kozai ■) was spray coated thereon in an amount of 0.6 kg/m2, and an adhesion test was conducted 3 days later.

Example 3 Contaminants such as earth and sand on a 20-year-old large corrugated asbestos slate roof were removed using a broom, and aged areas on the surface were removed using a wire brush. It was spray coated at an amount of 6ks/m'' and an adhesion test was conducted 3 days later.

Example 4 After applying Example 3, apply 0.5k of acrylic air-drying paint (manufactured by Hitachi Kasei Kozai ■, Istar Ascoat ■) on top of it.
It was applied by spraying in an amount of 100 g/m'' and an adhesion test was conducted 3 days later.

Comparative Example 1 In the same manner as in Example 1, a polyincyanate compound (GSR-
PR (containing 60% organic solvent) was spray applied in an amount of 0.5 kg/m'', and after 3 days, an adhesion test was conducted.

Comparative Example 2 As in Example 3, a polyisocyanate compound was bonded to asbestos slate from which the aged portion of the surface had been removed.

Comparative Example 3 On top of Comparative Example 1, an acrylic air-drying paint (Histar Ascor If manufactured by Hitachi Chemical Kozai ■) was spray applied in an amount of 0, s kg/m'', and after 3 days an adhesion test was conducted.

Comparative Example 4 On Comparative Example 2, an acrylic air-drying paint (Histar Ascoat If manufactured by Hitachi Chemical Kozai ■) was spray applied in an amount of 0.5 kg/m'', and an adhesion test was conducted 3 days later.

Comparative Example 5 As in Example 1, an asbestos slate whose surface had been cleaned with a broom was directly sprayed with an acrylic air-drying paint (Histar Ascoat II manufactured by Hitachi Chemical Kozai ■) at an amount of 0.5 kg/m''. An adhesion test was conducted after 1 day.

Comparative Example 6 As in Example 3, acrylic air-drying paint (Hyster Ascoat II manufactured by Hitachi Chemical Co., Ltd.) was sprayed directly onto asbestos slate from which the aged parts of the surface had been removed in an amount of 5 kg/~2. An adhesion test was conducted 3 days after application.

The evaluation test was conducted using the method shown below, and the results are shown in Table 1.

Adhesion test: According to JIS K 5400, 100 cuts were made at 211110 corners using a cutter.

After pasting and peeling off the tape The evaluation was based on the number of squares remaining in the area.

Impact resistance test: Conducted according to JIS A 5403. This was carried out for Example 1 and Comparative Example J.

Weather resistance test: The condition was visually observed after being left for one year.

(Effects of the Invention) According to the repair method of the present invention, there is no need to remove aged materials on asbestos slate by spraying high-pressure water, brushing with a wire brush, etc., so the work process can be simplified, and It also serves as an environmental protection measure by suppressing the floating of asbestos dust from the asbestos slate surface. Further, since there is no need to dissolve the composition used in a solvent, workability and safety can be further improved.

The asbestos slate repaired according to the present invention has excellent adhesion between the asbestos slate and the repair material, and between the repair material and the paint, has high strength, and has improved weather resistance, and can maintain its repair effect for a long period of time. .

Claims (1)

[Claims] 1. General formula (I); ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) Contains a compound represented by (in the formula, R represents hydrogen or a methyl group) as an essential component 1. A method for repairing asbestos slate, which comprises applying a composition to the surface of the asbestos slate.