JPH0959078A - Cement-based substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the formation of a protecting layer for screening ultraviolet rays without deteriorating the texture of a cement-based substrate by using a synthetic resin coating material containing an inorganic pigment having a prescribed weight- average particle diameter or below as an intermediate coating material in the cement- based substrate having a film formed of an undercoating material, the intermediate coating material and a finish coating material. SOLUTION: This cement-based substrate has a film formed of an undercoating material, an intermediate coating material and a finish coating material. The undercoating material (e.g. a silicon-based coating material or an epoxy resin-based coating material) has <=10μm film thickness and a synthetic resin coating material containing an inorganic pigment (e.g. zinc oxide) having <=0.1μm weight-average particle diameter in an amount of 50-150wt.% based on the resin solid content is used as the intermediate coating material (e.g. a fluororesin-based coating material or a polyurethane resin-based resin material) and the dry film thickness is preferably 5-60μm. For example, the fluororesin-based or polyurethane resin-based coating material is used also as the finish coating material. A concrete, an asbestos slate, a mortar, an ALC board, a calcium silicate-based material, gypsum, a slag-based material, etc., are cited as the cement-based substrate. A two-part cold curing type coating material is preferred as the intermediate and finish coating materials.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement-based base material having a coating film excellent in transparency and ultraviolet ray shielding performance.

[0002]

2. Description of the Related Art Conventionally, cement-based base materials such as concrete, asbestos slate, mortar, ALC plate, calcium silicate-based material, gypsum and slag-based material have been widely used for construction and building materials, and such materials have a beauty. To impart sex,
Solution-type acrylic resin-based, acrylic urethane resin-based, and fluororesin-based paints have been applied for the purpose of improving durability.

However, a coating film obtained by applying such a paint generally changes the appearance of the cement-based base material in most cases, and it has been difficult to realize, for example, "a feeling of exposed concrete". Also, the cement-based base material is
In general, it is difficult to apply a thin and uniform surface because it is uneven, and it has been customary that when a transparent finishing material is applied, unevenness due to unevenness such as wet skin color occurs.

[0004]

The present invention does not have the above-mentioned drawbacks of the prior art, and even if it is transparent, it does not give a wet skin color,
Another object of the present invention is to provide a cement-based base material having a coating film having excellent ultraviolet shielding performance.

[0005]

The present invention is a cement-based base material having a coating film formed of a synthetic resin paint containing an inorganic pigment having a weight average particle diameter of 0.1 μm or less.

The present invention is also a cement-based base material having a coating film formed of an undercoat material, an intermediate coating material and an overcoat material, wherein the intermediate coating material comprises an inorganic pigment having a weight average particle diameter of 0.1 μm or less. It is a cement-based base material characterized by being a synthetic resin paint containing the same.

As the synthetic resin coating material of the present invention, ordinary synthetic resin coating materials can be widely adopted. Preferred synthetic resin paints include synthetic resin paints containing vinyl resin, acrylic resin, epoxy resin, polyurethane resin, chlorinated polyolefin resin, silicone resin, polybutadiene resin, fluororesin, etc. as main components. These resins may be used alone or in combination of two or more. More preferably, it is a coating material containing a fluororesin as a main component, which is excellent in weather resistance.

A wide variety of fluororesins for paints can be used as the fluororesin. Preferred is a fluorine-based copolymer obtained by copolymerizing a fluoroolefin and another monomer copolymerizable with the fluoroolefin.

Examples of such fluoroolefins include tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride and the like, and perhaloolefins such as tetrafluoroethylene and chlorotrifluoroethylene are preferable.

An ethylenically unsaturated compound is preferably used as the other monomer copolymerizable with the fluoroolefin. Examples of the ethylenically unsaturated compound include vinyl ether, allyl ether, carboxylic acid vinyl ester, carboxylic acid allyl ester, and olefin.

Examples of the vinyl ether include cycloalkyl vinyl ether such as cyclohexyl vinyl ether, nonyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether and the like. Examples of the allyl ether include alkyl allyl ethers such as ethyl allyl ether and hexyl allyl ether.

Examples of carboxylic acid such as carboxylic acid vinyl ester and carboxylic acid allyl ester include acetic acid, butyric acid, pivalic acid, crotonic acid and benzoic acid. Also,
As the vinyl ester of a carboxylic acid having a branched alkyl group, commercially available Veova-9 and -10 (both manufactured by Shell Chemical Co., Ltd.) can be used. Examples of olefins include ethylene and isobutylene.

The other monomer which can be copolymerized with the above-mentioned fluoro-olefin is not only one kind but also two kinds such as two kinds in vinyl ether and two kinds of vinyl ether and carboxylic acid vinyl ester. The above monomers can be used in combination. The fluorine-based copolymer may be a copolymer having no curing reactive site, but is preferably a copolymer having a curing reactive site.

The curing reactive site may be one that reacts with a curing agent to form a crosslink. The curing reactive site can be appropriately selected depending on the combination with a curing agent, and typical examples thereof include a hydroxyl group, a carboxyl group, a glycidyl group, an epoxy group and an amino group. Examples of the method of introducing such a curing reactive site include a method of copolymerizing a monomer having a curing reactive site during a copolymerization reaction.

It is also possible to introduce a curing reactive site by post-reaction after polymerization. Examples of this method include the following methods (1) to (4).

(1) A method of introducing a hydroxyl group by saponifying a polymer obtained by copolymerizing a carboxylic acid vinyl ester. (2) A method of introducing a carboxyl group by reacting a polymer having a hydroxyl group with a polycarboxylic acid or an anhydride thereof. (3) A method of reacting an isocyanate alkoxysilane with a polymer having a hydroxyl group to introduce a hydrolyzable silyl group. (4) A method of introducing an isocyanate group by reacting a polymer having a hydroxyl group with a polyvalent silyl isocyanate compound.

Examples of the monomer having a curing reactive site include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether and 4-hydroxybutyl vinyl ether, hydroxycycloalkyl vinyl ethers such as monohexane ether of cyclohexanedimethanol, and 2-hydroxyethyl allyl ether. Such as hydroxyalkyl allyl ether, monomers having a carboxyl group such as 10-undecenoic acid, monomers having a hydrolyzable silyl group such as triethoxyvinylsilane, glycidyl vinyl ether, glycidyl allyl ether, β
Examples thereof include a monomer having an epoxy group such as methylglycidyl vinyl ether, and a monomer having an amino group such as aminopropyl vinyl ether and aminopropyl allyl ether.

The proportion of polymerized units based on fluoroolefin contained in all polymerized units of the fluorine-based copolymer is usually 20 to 80 mol%, preferably 40 to 60 mol%.
It is. The ratio of the polymerized units having a curing reactive site contained in all the polymerized units of the fluorine-based copolymer is usually 0.1 to 10.
It is 50 mol%, preferably 1 to 30 mol%.
The number of curing reactive sites such as hydroxyl groups and carboxyl groups in the above copolymer is preferably equivalent to 1 to 150 mg / g based on the resin solid content in terms of chemical reaction equivalent of potassium hydroxide, 10 to 130 mg / g
Is preferred.

A coating material containing a fluororesin as a main component can be prepared by combining the above-mentioned fluororesin with a curing agent. As such a curing agent, those known as a curing agent for paints can be used. Specific examples thereof include melamine-based curing agents such as aminoplast and urea resin, polyvalent isocyanate-based curing agents, and block polyvalent isocyanate-based curing agents. Further, a polyvalent isocyanate curing agent that does not require high temperature baking and can be installed on site is preferably adopted. In particular, a non-yellowing type polyvalent isocyanate curing agent is preferably used.

Weight average particle diameter of the present invention 0.1 μm
The following inorganic pigments (hereinafter referred to as "ultrafine particle pigments") give a coating film on the cement-based substrate formed by the above synthetic resin paint, even if they are transparent, do not give a wet skin color and also provide an ultraviolet shielding performance. And is selected from transparent or nearly transparent pigments.

If the particle size of the ultrafine particle pigment is too large, the ultraviolet ray shielding performance is impaired, and even if it is transparent, a wet skin color is obtained. Therefore, the weight average particle size is 0.1 μm or less, preferably 0.05 μm or less. And more preferably, the weight average particle diameter is in the range of 0.005 to 0.03 μm.

Examples of ultrafine pigments include titanium oxide, zinc oxide, tin oxide, cerium oxide, calcium oxide, antimony oxide, chromium oxide, cobalt oxide, zirconium oxide, tungsten oxide, iron oxide, copper oxide, thorium oxide, nickel oxide. , Palladium oxide, and molybdenum oxide. Preferred are titanium oxide, zinc oxide, tin oxide, and cerium oxide.

The content ratio of the ultrafine particle pigment in the coating film formed by the synthetic resin paint is usually 50 to 150% by weight (relative to the resin solid content), preferably 75 to 120% by weight. %. If the content ratio is too low, the ultraviolet shielding performance is reduced, and the appearance after coating becomes wet skin color, which is not preferable. If the content ratio is too large, the transparency is impaired and the "feeling of the concrete exposed" is impaired, which is not preferable.

The dry film thickness of the coating film formed of the synthetic resin coating material is preferably 10 to 200 μm, more preferably 20 to 100 μm.

The coating film on the cement-based substrate in the present invention may be composed of only one layer of the coating film containing the ultrafine particle pigment, and the coating film containing the ultrafine particle pigment and the coating film containing no ultrafine particle pigment. 2 layers, a coating film containing no ultrafine particle pigment, a coating film containing an ultrafine particle pigment and a coating film containing no ultrafine particle pigment. In the case of two or more layers, two or more layers of coating films having different types of ultrafine particle pigments may be used, or two or more layers of coating films having different types of synthetic resin coating materials may be used.

In order to prevent the coating film on the cement-based substrate from being transparent and not to give a wet skin color and to effectively provide the ultraviolet shielding performance, this coating film is used as an undercoating material, an intermediate coating material and an overcoating material. It is preferable to use three layers of the coating film formed by. In this case, the ultrafine particle pigment may be blended in all of the above three layers, but it is preferably blended only in the above intermediate coating material.

The undercoating material is transparent and is selected from those which function as a primer with a small coating amount and ensure the adhesion between the cement-based base material and the intermediate coating material. For example, a coating material containing a vinyl resin, an acrylic resin, an epoxy resin, a polyurethane resin, a chlorinated polyolefin resin, a silicone resin, a silicon compound or a condensate thereof, a polybutadiene resin, a fluororesin or the like as a main component is preferable. In particular, a silicon compound or a condensate thereof that easily achieves adhesion with a small amount of coating, a silicon-based paint containing a silicone resin as a main component, or an epoxy resin-based paint containing an epoxy resin as a main component is particularly preferable.

As the epoxy resin, a curing agent such as amines or polyamide resin may be used in combination, or a modified epoxy resin in which an acrylic monomer or amine is bonded to epoxy groups at both ends may be used. As the silicone resin, a modified silicone resin such as alkyd-modified, acrylic-modified or epoxy-modified can be used.

As the silicon compound or its condensate,
For example, methyltrimethoxysilane, methyltriethoxysilane, methyltriisobutoxysilane, methyltributoxysilane, tetramethoxysilane, tetraethoxysilane, tetraisobutoxysilane, tetrabutoxysilane, methyltriphenoxysilane, tetraphenoxysilane, phenyl. Silicon compounds such as trimethoxysilane, phenyltriethoxysilane, methyltri (acryloyloxyethoxy) silane, methyltri (glycidyloxy) silane, octyltriethoxysilane, lauryltriethoxysilane, stearyltrimethoxysilane, stearyltriethoxysilane or their condensation Things can be mentioned.

Commercially available water absorption inhibitors containing these silicon compounds or condensates thereof, such as Aron Water Shut (manufactured by Toagosei Chemical Industry Co., Ltd.), Excella (manufactured by Kansai Paint Co., Ltd.), Aqua Seal (Sumitomo Seiki) Chemicals), Dickguard (manufactured by Dainippon Ink and Chemicals, Inc.), etc. can also be used as the undercoat material.

Further, it is preferable that the undercoating material is applied to such an extent that the appearance of the cement-based base material is not impaired. Further, it is preferable to apply the coating to such an extent that it has a function of securing adhesion with an intermediate coating material, which is a purpose of a normal undercoating material, and protecting a substrate. Specifically, the water permeability after 24 hours in the water permeability test of JIS-A6910 is 0.15 to 0.15.
It is preferable to apply the paint so that the amount becomes 2.00 g. Further, in consideration of the appearance, it is preferable that the film thickness is about 10 μm or less.

The intermediate coating material generally has a function of correcting uneven suction, which tends to occur when a small amount of the above-mentioned undercoat material is applied to a cement-based base material having a non-uniform surface, and water, acid
It is selected from those having a function of protecting the cement-based base material against chemicals such as alkali and solvent and corrosive gas.

For example, vinyl resin, acrylic resin, epoxy resin, polyurethane resin, chlorinated polyolefin resin, silicone resin, silicon compound or its condensate,
A coating material containing a polybutadiene resin, a fluororesin or the like as a main component is preferable. Considering durability, a fluororesin-based coating material containing a fluororesin as a main component or a polyurethane resin-based coating material containing a polyurethane resin as a main component is more preferable.

When the intermediate coating material contains the ultrafine particle pigment, the content ratio of the ultrafine particle pigment in the coating film formed by the intermediate coating material is usually 50 to 150% by weight (based on the resin solid content). Is suitable, and preferably 75 to 120% by weight. If the content ratio is too low, the ultraviolet shielding performance is reduced, and the appearance after coating becomes wet skin color, which is not preferable. If the content ratio is too high, the transparency is impaired and the "feeling of the concrete being exposed" is impaired, which is not preferable. The dry film thickness of the coating film formed by the intermediate coating material is 5 to 60 μm.
m is preferable, and more preferably, 10 to 30 μm.

The top coat material, together with the intermediate coat material, is generally used for protecting the cement-based base material against ultraviolet rays, water, chemicals such as acid / alkali / solvent, corrosive gas, etc. It is selected from those having the function of an intermediate coating material and a top coating material.

For example, a paint containing a vinyl resin, an acrylic resin, a polyurethane resin, a chlorinated polyolefin resin, a silicone resin, a silicon compound or a condensate thereof, a polybutadiene resin or a fluororesin as a main component can be used.
Considering durability, a fluororesin-based coating material containing a fluororesin as a main component or a polyurethane resin-based coating material containing a polyurethane resin as a main component is preferable.

As the fluororesin preferably used as the intermediate coating material and the top coating material, a fluorine-based copolymer obtained by copolymerizing the above-mentioned fluoroolefin with another monomer copolymerizable therewith is polyurethane. As a resin,
It is possible to use those whose polyol component is an acrylic polyol or a polyester polyol. When the intermediate coating material contains the ultrafine particle pigment, the topcoat material may not contain the ultrafine particle pigment.

Since the coating film formed on the cement-based base material of the present invention is often applied on site, it is excellent as a synthetic resin coating material for the intermediate coating material and the top coating material because it does not require high temperature baking. A two-part room temperature curing type coating that gives a finished appearance is preferable. Examples of such a two-component room temperature curing type coating material include a coating material containing a polyurethane resin or a fluororesin as a main component, and a coating material containing a fluororesin as a main component, which is particularly excellent in weather resistance, is preferable.

The cement-based base material of the present invention is a base material made of a cement-based material such as concrete, asbestos slate, mortar, ALC plate, calcium silicate-based material, gypsum and slag-based material. Examples of the base material Examples thereof include building members such as buildings and building materials.

[0040]

Example 1 (Example) 30 g of methyltrimethoxysilane (hereinafter abbreviated as A in Table 1) was dissolved in 70 g of isopropanol, and sprayed as an undercoat paint on a dry-cured concrete ordinary pavement flat plate. It was applied to a dry film thickness of 5 μm. Then, an organic solvent solution containing 60% by weight of a fluororesin obtained by copolymerizing chlorotrifluoroethylene / cyclohexyl vinyl ether / ethyl vinyl ether / hydroxy vinyl ether = 50/20/20/10 mol% (hereinafter referred to as B in Table 1). (Abbreviated) 18 g of zinc oxide ultrafine particles (weight average particle diameter: 0.01 μm) is mixed and dispersed in a ball mill together with a dispersant and a defoaming agent in 30 g, and Coronate EH (manufactured by Nippon Polyurethane Company, non-yellowing) as a curing agent. (Type isocyanate curing agent) (3.4 g) was added to dilute the composition to a spray viscosity, and the intermediate coating was applied to a dry film thickness of 20 μm.

Furthermore, 57 g of Lumiflon LF-200
Defoamer is added to and mixed with curing agent Coronate EH 6.4 g
Was added to dilute to a spray viscosity, and a dry coating film having a thickness of 20 μm was applied as a top coating material. Table 1 shows the appearance of this coating test piece.
It was shown to.

[Examples 2 to 5 (Examples), Examples 6 to 7 (Comparative Examples)] Appearances of test pieces prepared in the same manner as in Example 1 by adjusting various paints as an undercoat paint, an intermediate paint and a topcoat paint. And the results are shown in Table 1. Here, “good appearance” refers to the case where the texture of the concrete ordinary flat plate for paving the base material is retained. In addition, as a weather resistance test method, the test body was dried for 7 days and then 4000
Irradiated for hours. When the gloss retention rate after the test is 80% or more,
61 to 79% was designated as Δ, and 60% or less was designated as x.

Synthetic resin C in the table is ACRYDIK BU-955 (an organic solvent solution containing 60% by weight of a polyurethane resin for coatings whose polyol component is an acrylic polyol) manufactured by Dainippon Ink and Chemicals, Inc. The particle diameters of the pigments in the table are weight average particle diameters.

[0044]

[Table 1]

[0045]

EFFECTS OF THE INVENTION The cement-based base material of the present invention can form a protective layer that shields ultraviolet rays without impairing the texture of the cement-based base material.

Claims (3)

[Claims] 1. A cement-based base material having a coating film formed of a synthetic resin paint containing an inorganic pigment having a weight average particle diameter of 0.1 μm or less. 2. A cement-based base material having a coating film formed of an undercoat material, an intermediate coating material and an overcoat material, the intermediate coating material containing an inorganic pigment having a weight average particle diameter of 0.1 μm or less. Cementitious base material characterized in that 3. The undercoat material is a silicon-based paint or an epoxy resin-based paint, the intermediate coating material is a fluororesin-based paint or a polyurethane resin-based paint, and the topcoat material.
Cementitious base material.