JPH05271606A - Coating composition and application method - Google Patents

Abstract

PURPOSE:To obtain a coating composition which gives a coating film excellent in weatherability, adhesion to concrete or tile, and wet color by incorporating a fluororesin coating composition containing a polymer having a hydrolyzable silyl group and an NOC group. CONSTITUTION:This coating composition comprises a fluororesin coating composition obtained by dissolving in a solvent a methacrylate polymer having a hydrolyzable silyl group and an NOC group (e.g. copolymer comprising a methyl methacrylate unit as the main unit and units of comonomers such as delta- methacryloxypropyltrimethoxysilane and isocyanatoethyl methacrylate), a vinylidene fluoride resin soluble in a solvent at ordinary temp. (e.g. terpolymer of vinylidene fluoride, tetrafluoroethylene, and hexafluoropyrene), and a dehydrant (e.g. trimethyl orthoacetate). By the use of this composition, the surface and inner parts of a concrete or tile object can be protected against weathering without impairing the surface design of the object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather-resistant coating composition for protecting exposed concrete or tile surfaces from weathering without impairing the design of the surfaces and a method of applying the same.

[0002]

2. Description of the Related Art The exposed surface of concrete has a heavy weight that is not found in tile and spray finish in terms of its design.
It is simple and strong and has been used as a finishing method for many architectural and civil engineering structures. However, the exposed surface is blackened by air pollutants and rainwater several years after construction, and the design is remarkably impaired.Furthermore, the rainwater that has penetrated into the concrete causes the reinforcing bars to rust and the strength of the concrete decreases. , Even social problems. In addition, the above-mentioned problem also occurs in tiles, although there is a degree of difference.

As a conventional technique for solving these problems, a permeation type waterproofing agent which dissolves a silane-based oligomer in an organic solvent and permeates it into concrete to form a waterproof layer inside the concrete is used. However, the weather resistance was low, and the waterproof performance deteriorated after several years due to weathering, and the effect was insufficient compared to the service life of the building. Also,
For imparting weather resistance to this, it is used, for example, as a normally dry fluorine coating. It is possible to apply a fluorine-based clear paint prepared by dissolving a urethane cross-linked fluoroethylene vinyl ether terpolymer in an organic solvent onto concrete after application of a permeation-type waterproofing agent, but the surface of the concrete is dark gray as if wet with rain. It has a strong "wet color", which significantly impairs the design properties of exposed concrete, and also has insufficient adhesion after freeze-thaw cycle tests, causing the coating to peel off during winter in cold regions. There was a problem that it became easier to do.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and a coating composition excellent in weather resistance, adhesion to concrete or tile, and wet colorability, and a method of applying the same. The purpose is to provide.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a coating composition for coating concrete or tile surfaces (hereinafter, simply referred to as a fluorine-containing coating composition containing a polymer having a hydrolyzable silyl group and an isocyanate group). "Coating compositions"), and methods for durable application of concrete or tile surfaces to which these coating compositions are applied. The fluorine coating material in the present invention is not particularly limited as long as it is a fluorine coating material containing a polymer having a hydrolyzable silyl group and an isocyanate group, and examples of the polymer having these functional groups include fluoroethylene vinyl ether. A copolymer obtained by copolymerizing a vinyl monomer having a hydrolyzable silyl group or an isocyanate group with a copolymer, a methacrylate copolymer having a hydrolyzable silyl group and an isocyanate group (hereinafter referred to as a methacrylate polymer (A ))) And the like. In the present invention, a methacrylate polymer having these functional groups is preferable.

The methacrylate polymer (A) in the present invention comprises a monomer having a isocyanate group and a monomer having a hydrolyzable silyl group in the main chain in a molar ratio of monomer units. It has been copolymerized. Examples of the methacrylate-based monomer include methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and the like. Examples of the monomer copolymerized with the methacrylate-based monomer include acrylic acid esters such as methyl acrylate, butyl acrylate and 2-ethylhexyl acrylate, and carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid and fumaric acid. Anhydrides such as acids and maleic anhydride, epoxy compounds such as glycidyl acrylate,
Amino compounds such as diethylaminoethyl acrylate, diethylaminoethyl methacrylate, aminoethyl vinyl ether, acrylamide, methacrylamide, itaconic acid diamide, α-butyl acrylamide,
Crotonamide, fumaric acid diamide, maleic acid diamide, amide compounds such as N-butoxymethyl acrylamide, N-butoxymethyl acrylamide, acrylonitrile, iminol methacrylate, styrene, α-methylstyrene, vinyl chloride, vinyl acetate, propion vinyl acetate, etc. Is mentioned. More preferably, the polymerization composition of methyl methacrylate is 60 to 99.0% in molar ratio.
It is a polymer containing.

The isocyanate group-containing monomer usable in the present invention includes isocyanate ethyl acrylate, isocyanate ethyl methacrylate, isocyanate propyl acrylate, isocyanate propyl methacrylate and its derivatives, m-isopropenyl-
Although there are α, α-dimethylbenzene diisocyanate and the like, isocyanate ethyl methacrylate is preferable. Further, the hydrolyzable silyl group used in the present invention is
General formula

[0008]

[Chemical 1] (X is a hydrolyzable group or element, R ₁ is hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group or an aralkyl group, and n is an integer of 1 to 3). As a group, a halogen element, an alkoxy group, an acyloxy group, a ketoximate group, an amide group, an acid amide group,
An aminooxy group, a mercapto group, and an alkenyloxy group are contained, but it is preferable to use an alkoxyl group from the viewpoint of handleability as a paint, reaction rate, odor, and generation of a corrosive substance. The number of carbon atoms of the alkoxyl group is 1 to 1.
0 is preferable, more preferably 1 to 5, for example, methoxy group, ethoxy group, propoxy group, butoxy group,
Pentoxy groups are preferred from the viewpoint of the crosslinking reaction rate of the paint.

Examples of the monomer containing a hydrolyzable silyl group which can be used in the present invention include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxylan, vinylmethyldiethoxysilane and vinyltris (β-methoxyethoxy) silane. , Allyltrimethoxysilane, trimethoxysilylethyl vinyl ether, triethoxysilylethyl vinyl ether, methyldimethoxysilylethyl vinyl ether, triethoxysilylpropyl vinyl ether, methyldimethoxysilylpropyl vinyl ether, γ- (meth) acroyloxypropyltrimethoxysilane, γ Examples thereof include-(meth) acroyloxypropyltriethoxysilane and γ- (meth) acroyloxypropylmethyldimethoxysilane.

In the present invention, the ratio of the isocyanate group-containing monomer and the hydrolyzable silyl group-containing monomer contained in the methacrylate polymer (A) is preferably 0.001 to 0.001 in terms of molar ratio. It is 30%, more preferably 0.1 to 15%. When not using a monomer containing an isocyanate group, the crosslinking reaction rate is slow,
In particular, the curing at room temperature is insufficient and the boiling water resistance is poor, and even if a curing agent for a hydrolyzable silyl group is added to this to accelerate the curing speed, the stain removability deteriorates, which is not suitable. Further, when a monomer containing a hydrolyzable silyl group is not used, the effect of crosslinking is obtained, but the adhesiveness to concrete and porcelain tile is deteriorated, which is not preferable. Further, when the monomer containing the isocyanate group or the hydrolyzable silyl group is contained in a molar ratio of 30% or more, storage stability is deteriorated, which is not preferable. In the present invention, the molecular weight of the methacrylate polymer containing an isocyanate group and a hydrolyzable silyl group is not particularly limited, but the number average molecular weight is 1,000 to 100,000, preferably 4,
It is 000 to 20,000. The method for producing a methacrylate-based polymer having an isocyanate group and a hydrolyzable silyl group in the present invention is not particularly limited,
Obtained by copolymerizing a monomer having an isocyanate group and having a polymerizable double bond with a monomer having a hydrolyzable silyl group and having a polymerizable double bond, and the above methacrylate compound. The method is exemplified as an industrially simple and effective method.

As the fluorine coating material in the present invention, a combination of the above-mentioned methacrylate polymer (A) and a fluorine polymer is preferable. The polymer component of the fluoropolymer used in the present invention is a homopolymer of vinylidene fluoride or vinylidene fluoride and vinyl fluoride, trifluoroethylene, tetrafluoroethylene, bromotrifluoroethylene, chlorotrifluoroethylene, pentafluoropropylene. , Hexafluoropropylene, and at least one fluoroolefin monomer selected from the group consisting of perfluoroalkyl, trifluoroalkyl, and trifluorovinyl ether. Particularly preferably, it is a terpolymer of vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene, and the amount of vinylidene fluoride used is preferably 10 to 99%, more preferably 60 to 90% in terms of monomer ratio. %. Mixing ratio (weight) of fluoropolymer and methacrylate polymer (A) in the present invention
Is preferably 3: 7 to 9: 1, and when the ratio of the fluoropolymer is less than 3: 7, the weather resistance is poor, and when it is more than 9: 1, the crosslinking effect cannot be obtained. More preferably 5: 5
It is 8: 2.

In the present invention, it is preferable to further use a dehydrating agent (C). The dehydrating agent (C) used in the present invention is
It is an ester-based dehydrating agent with a high hydrolysis rate, and specifically, trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, trialkyl orthoformates such as tributyl orthoformate, trimethyl orthoacetate, trimethyl orthoacetate, Trialkyl orthoacetates such as triethyl orthoacetate, tripropyl orthoacetate and tributyl orthoacetate, and tetraalkyl orthosilicates such as tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate and tetrabutyl orthosilicate are used. Further, oligomers of orthosilica tetraalkyl obtained by dehydration condensation of tetraalkyl orthosilicate after partial hydrolysis, or alkoxides of silicon elements such as methyltrimethoxysilane, ethyltrimethoxysilane, methyltriethoxysilane, and ethyltriethoxysilane, and the like. It is also possible to use a partially hydrolyzed product and a dehydrated condensate. The addition amount of the dehydrating agent in the present invention is usually 0.1 to 15% by weight based on the coating composition.

The coating composition of the present invention comprises the above-mentioned methacrylate polymer (A), fluoropolymer and dehydrating agent dissolved in a solvent (hereinafter, the mixture thereof is referred to as "varnish"). The amount of the solvent in the present invention is preferably 5 to 95% by weight, more preferably 50 to 20% by weight, particularly preferably 3 to the varnish.
It is 0 to 40% by weight. The solvent that can be used in the present invention is an aliphatic or alicyclic ketone-based, ester-based, or ether-based organic solvent. Among these, it is preferable to include an organic solvent having a boiling point of 100 ° C. or higher in order to form a smooth coating film. For example, as a ketone type, methyl n-propyl ketone, diethyl ketone, methyl isobutyl ketone,
Methyl n-butyl ketone, ethyl n-butyl ketone, methyl n-amyl ketone, diisobutyl ketone, methyl n
-Hexyl ketone, mesityl oxide, cyclohexanone, diacetone alcohol, methylphenol ketone,
Isophorone; as an ester type, n-propyl acetate, n-butyl acetate, isobutyl acetate, 2-methoxyethyl acetate, amyl acetate, dimethyl adipate, dimethyl glutarate, dimethyl succinate; as an ether type, methyl cellosolve, 2 -Methoxy-2-
Examples include propylene glycol monomethyl ether acetate such as propanol cellosolve, 1-ethoxy-2-propanolbutyl cellosolve, and 1,4-dioxane.

The coating composition of the present invention may be used as a colored clear paint using a small amount of pigments and dyes in order to enhance the design. Further, an ultraviolet absorber and a light stabilizer may be added to improve weather resistance. The coating composition of the present invention is used for coating concrete and tile surfaces. ALC board for concrete,
Also includes mortar, slate and PC board. Further, the coating composition of the present invention has good adhesion to the concrete and tiles, but it is also possible to apply a permeation-type waterproofing agent to the surface of the concrete or tiles in advance in order to obtain further excellent effects. .. In the present invention, the permeation type waterproofing agent is not particularly limited as long as the waterproofing agent permeates into the concrete and the entire permeating part is given a waterproofing action, for example, a silicone resin having a low molecular weight and soluble in an organic solvent. Or a siloxane-based monomer, a siloxane-based oligomer, water glass, or the like.

[0015]

EXAMPLES Next, the present invention will be described in more detail by showing Examples and Comparative Examples of the present invention. Example 1 42 g of "KYNAR ADS" (manufactured by ATOCHEM) and γ
-A methacrylate-based polymer obtained by copolymerizing a monomer mixture consisting of 3 mol% of methacryloxypropyltrimethoxysilane, 2 mol% of isocyanate ethyl acrylate, 85.5 mol% of methyl methacrylate and 9.5 mol% of butyl acrylate in toluene ( 40% concentration, Mn
10,000) 70 g, methyl orthoacetate 0.6 g and butyl acetate 28.4 g were added to methyl isobutyl ketone 1
Add to a mixed solvent consisting of 9.0 g and 40.6 g of propylene glycol methyl ether acetate, and add at 80 ° C.
The mixture was heated and stirred for 1 hour to dissolve it to obtain a coating composition.

Next, the penetration type waterproofing agent Toss barrier 100
37 g (manufactured by Toshiba Silicone) is applied evenly on the entire surface of a concrete specimen (100 × 80 × 125 mm W / C 55%, age 4 weeks) beforehand, and when it is dried, 12 g of the above coating composition is also applied over the entire surface. It was evenly painted and cured for 7 days. Regarding the obtained coating film, J
According to IS K6910, the appearance and the secondary adhesion after the "non-resistance to repeated hot and cold action" test, JI
It was evaluated by the grid tape method described in SK5400 (gap 1 mm). Further, the neutralization prevention performance was evaluated.
The test conditions are: CO ₂ concentration 10%, temperature 30 ° C., humidity 60
Place the concrete specimen after painting in an atmosphere of 3%
Left for a month. The test body after standing was cut into two parts, and a 1 wt% phenolphthalein alcohol solution was sprayed on the cross section, and the depth from the surface of the part that did not develop color was measured as the neutralization depth. The results are shown in Table 1. The secondary adhesion and the neutralization depth were good.

Example 2 A concrete specimen prepared in the same manner as in Example 1 (100
The coating composition was applied in the same manner as in Example 1 except that the permeation-type waterproofing agent was not applied to (× 80 × 125 mm), and the physical properties of the coating film were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 A test sample was prepared by applying 37 g of a permeation type waterproofing agent (Tosbarrier 100) to the entire surface of a concrete specimen, and cured for 7 days. The test sample thus obtained was subjected to the procedure of Example 1 except for "resistance to repeated hot and cold action".
The neutralization prevention performance was evaluated in the same manner as. Table 1 shows the evaluation results
Shown in. When the coating composition obtained according to the invention is unpainted, the neutrality-preventing performance is reduced.

Comparative Example 2 An example of the coating composition of Example 1 except that the composition of the methacrylate copolymer was not γ-methacryloxypropyltrimethoxysilane but was 5 mol% of isocyanate ethyl acrylate. A coating composition was obtained in the same manner as in Example 1, except that the same methacrylate copolymer as in Example 1 was used. This coating composition was evaluated in the same manner as in Example 1, and the results are shown in Table 1. The secondary adhesion after the "resistance to repeated hot and cold action" test was poor.

Comparative Example 3 An example of the coating composition of Example 1 except that the composition of the methacrylate-based copolymer did not use isocyanate ethyl acrylate and the content of γ-methacryloxypropyltrimethoxysilane was 5 mol%. A coating composition was obtained in the same manner as in Example 1, except that the same methacrylate copolymer as in Example 1 was used. This coating composition was aged at room temperature for 7 days in the same manner as in Example 1 and evaluated. Due to insufficient curing, cracks were generated after the "resistance to repeated hot and cold action" test.

Comparative Example 4 Of the coating composition of Example 1, the composition of the methacrylate copolymer was 90 mol% of methyl methacrylate,
Example 1 except that the butyl acrylate was 10 mol%.
The same coating composition as above was obtained. This coating composition was evaluated in the same manner as in Example 1, and the results are shown in Table 1. Since it did not cure, cracks were formed after the "resistance to repeated action of hot and cold" test, and the secondary adhesion was also poor.

[0022]

[Table 1]

[0023]

EFFECTS OF THE INVENTION According to the present invention, for concrete and tiles, the one-component type has good resistance to repeated hot and cold actions without damaging the design of the surface of the concrete and tiles, and in particular, prevents neutralization inside the concrete. A coating composition and a method of applying the same can be provided.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C09D 143/04 LKA 7921-4J 175/04 PHR 8620-4J PHV 8620-4J

Claims (3)

[Claims] 1. A coating composition for coating concrete or tile surfaces, which comprises a fluorine coating material containing a polymer having a hydrolyzable silyl group and an isocyanate group. 2. A methacrylate polymer (A) containing a hydrolyzable silyl group and an isocyanate group, a vinylidene fluoride resin (B) soluble in a solvent at room temperature, and a dehydrating agent (C) dissolved in the solvent. A coating composition for coating concrete or tile surfaces, which comprises a fluorinated coating material. 3. A durable construction method for a concrete or tile surface, which comprises applying a penetrating waterproofing agent to the concrete or tile surface, and then applying the coating composition according to claim 1 or 2 thereon.