JPH03199179A - Method of protecting alkaline inorganic hardened body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel and useful method for protecting alkaline inorganic cured products. More specifically, the fluoroolefin copolymer emulsion should be used as a top coat because it has excellent ability to prevent leaching of alkaline substances, and also has excellent weather resistance, water resistance, and stain resistance. The present invention relates to a method of forming a film to protect an alkaline inorganic cured product.

[Conventional technology]

In the field of civil engineering and construction, the surface of alkaline inorganic hardened materials such as concrete frames, wall materials, or roofing materials is coated, but this mainly involves applying chemical resistance, water resistance, weather resistance, etc. to such base materials. Of course, protection and beauty were also taken into consideration.

Among these coating materials, those based on aqueous organic polymers are easy to process and therefore are frequently used.

As this type of polymer base, acrylic and acrylic-styrene copolymer bases have reached a certain level and are widely used.

However, especially when used as a building exterior material,
Although the service life is at least 10 years or more, and even semi-permanent products are now required, especially when acrylic or acrylic-styrene copolymer-based water-based polymers are used for the top coat, It is difficult to say that the weather resistance is sufficient, so repainting is necessary within a short period of time.

On the other hand, fluoroolefin copolymers are known as binders that provide high weather resistance and high chemical resistance, and organic solvent solutions are already commercially available.

However, since it contains a large amount of organic solvents, it poses a risk of fire, toxicity, and air pollution.
It has also become a social problem.

In contrast, the use of aqueous dispersions of polymers (fluoroolefin polymers) such as tetrafluoroethylene, vinylidene butylidene, or hexafluoropropylene has been proposed, but these all require high temperature baking. For example, JP-A-57
Publication No. 38845 discloses a copolymer of vinylidene butthoride and hexafluoropropylene, and the copolymer is a low molecular weight material with an intrinsic viscosity [η] of 0.1 to 0.5. Despite this, it is still 180~
It requires baking at a high temperature of 230°C.

Therefore, even for architectural paints that need to form a film at room temperature or factory paints that rely on forced drying, high-temperature baking as described above is practically impossible. It can be said that it is not suitable for

Furthermore, since fluoroolefin monomers are inherently expensive, it can be said that it is economically disadvantageous to compose a copolymer with these fluoroolefin monomers. .

By the way, JP-A No. 61-261367 discloses a coating resin based on an emulsion copolymer composed of fluoroolefins, alkyl vinyl ethers, and carboxylic acid vinyl esters as a method for solving the various problems mentioned above. A certain product has been disclosed, and it can be said that it can be applied to the protection of alkaline inorganic cured materials, but it has very poor adhesion to substrates, pigment dispersibility, and It is insufficient in terms of stain resistance, etc.

[11 that the invention attempts to solve! [Problem] As described above, as long as the conventional technology is followed, when coating the surface of alkaline inorganic base materials such as cement mortar, cement concrete, cement asbestos, or calcium silicate board, when these base materials come into contact with water,
It cannot block the leaching of alkaline substances during hydration and hardening, and it also has ultra-weather resistance that is sufficient for long-term outdoor exposure, as well as water resistance, chemical resistance, and stain resistance. The current situation is that there is no extremely useful protective means or protective material that has excellent film performance, and this is the current earnest desire of this industry.

To this end, the present inventors, based on the recognition of the current situation, the fundamental solution of various unresolved issues in the prior art, and the earnest needs of the industry, have devised a solution for alkaline substances in alkaline inorganic hardened bodies. leaching sealing ability and super weather resistance.
We have begun intensive research in search of an extremely useful method for protecting alkaline inorganic cured materials that can form a film with excellent water resistance, chemical resistance, and stain resistance.

Therefore, the problem to be solved by the present invention is to - reduce the appearance change of the alkaline inorganic cured body over time, and prevent deterioration of the base cured body;
Moreover, it is an object of the present invention to provide an extremely useful method for protecting an alkaline inorganic cured material that is easy to implement and economically advantageous.

[Means to solve the problem]

Therefore, the present inventor focused on the problems to be solved by the invention as described above, and as a result of intensive studies, a coating material using a specific emulsion copolymer called fluoroolefin copolymer emulsion as a binder was developed. When applied as a top coat of an alkaline inorganic cured material, there is little change in appearance or deterioration over time, and the protective film has excellent performance as described above, and is also easy to install. It has been confirmed that this is a simple and economically advantageous and extremely useful method for protecting alkaline inorganic cured products, and the present invention has been completed.

That is, the present invention seeks to provide a method for protecting an alkaline inorganic cured product, which comprises applying a coating composition containing a fluoroolefin copolymer emulsion as an essential binder component as a top coat. be.

In the present invention, the above-mentioned alkaline inorganic cured body is
For example, cement mortar, cement concrete,
It refers to a so-called hardened product prepared by hydrating and crystallizing an alkaline substance, such as asbestos concrete or calcium silicate board.
For example, it is used as a concrete frame, wall material, or roof material.

Here, the above-mentioned fluoroolefins are limited to particularly representative ones, such as vinyl butonide, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, 1,1,3゜3.3-pentafluoro Including fluoroolefins in the pure sense, such as propylene, 2.3.3.3-tetrafluoropropylene, 1.1.2-)lifluoropropylene or 3,3.3-1-lifluoropropylene, Furthermore, so-called fluorohalogen compounds such as chlorotrifluoroethylene, promotrifluoroolefins, 1-chloro-1,2-difluoroethylene or 1,1-dichloro-2,2-difluoroethylene, other than fluorine, may be used. Examples include fluoroolefins in a broad sense, including those having halogen atoms.

The proportion of such fluoroolefins in the fluoroolefin copolymer, that is, the proportion of the fluoroolefins in the copolymer,
Since the fluorine content itself has a large effect on the weather resistance of the resulting coating film, the fluorine content is preferably 5% by weight or more.

From this point of view, the type of fluoroolefin and the amount used should be selected, and the amount of fluoroolefin used is within the range of 10 to 70% by weight, preferably 30 to A range of 60% by weight is suitable.

On the other hand, other monomers that can be copolymerized with such fluoroolefins may be used to improve the copolymerizability with the fluoroolefins and the weather resistance, chemical resistance, water resistance, alkali resistance, etc. of the resulting fluoroolefin copolymers, among others. should be selected as appropriate, taking into consideration the film performance of various types of film, such as vinyl ethers, vinyl esters, and α-
Particularly representative examples include olefins.

Among these copolymerizable monomers, only the most representative ones as vinyl ethers are exemplified: methyl-, ethyl-1N-propyl-, isopropyl-1N-butyl-, isobutyl- Various alkyl vinyl ethers such as t-butyl-, isoamyl-1n-hexyl-1n-octyl or 2-ethylhexyl-vinyl ether; various cycloalkyl vinyl ethers such as cyclopentyl vinyl ether, cyclohexyl vinyl ether or methylcyclohexyl vinyl ether; benzyl; aralkyl vinyl ethers such as vinyl ether or phenethyl vinyl ether;
2,2,3.3-tetrafluoropropyl vinyl ether, 2.2,3.3.4.4.5.5-octafluoropentyl vinyl ether, 2.2°3, 3.4.4.5
．． 5,6.6.7.7.8.8.9.9-hexadecafluorononyl vinyl ether, perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoropropyl vinyl ether, perfluorooctyl vinyl ether or perfluorocyclohexyl vinyl ether or various hydroxyalkyl vinyl ethers such as 2-hydroxyethyl vinyl ether or 4-hydroxybutyl vinyl ether, which have a substituted or unsubstituted alkyl group.

Next, the vinyl esters mentioned above include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl persatate,
Various carboxylic acid vinyl esters such as vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pt-butylbenzoate, vinyl salicylate, vinyl monochloroacetate or vinyl cyclohexanecarboxylate.

Furthermore, the above-mentioned α-olefins include ethylene, propylene, butene-1, etc., to mention only typical ones.

Among the various copolymerizable monomers listed above, the amount of vinyl ethers and/or vinyl esters used is preferably within the range of 30 to 90% by weight based on the total monomers. is suitably within a range of 30 to 60% by weight, and furthermore, vinyl ethers and/or vinyl esters and α-olefins are each in a range of 25 to 85% by weight based on the total monomers. , 5-30%
preferably 30 to 60% by weight, and 10 to 60% by weight.
It is particularly preferable to use it in combination within the range of 20% by weight.

Increasing the molecular weight of the obtained fluoroolefin copolymer is also one of the particularly necessary means for improving the long-term durability of the film, and for that purpose, all crosslinkable monomers are It is preferable to copolymerize the monomers in an amount of 0.05 to 2% by weight, preferably 0.2 to 1.5% by weight.

Typical examples of such crosslinkable monomers include divinyl compounds and vinylsilanes, and specifically, polyalkylene glycol di(meth)acrylate and the like. Various di(meth)acrylate compounds; trialkylolalkane/tri
Various tri(meth)acrylate compounds such as (meth)acrylate; Various diallyl compounds such as diallyl phthalate; Various triallyl compounds such as triallyl isocyanurate; 1,7-octadiene or 1.9
-Various terminal dienes such as decadiene; or vinylalkoxysilanes having an alkoxysilyl group in the molecule, and these may of course be used alone or in combination of two or more.

The amount of such cross-linking monomers used is 0.
If it is less than 0.5% by weight, the crosslinking effect will inevitably be insufficient; on the other hand, if it is used in excess of 2% by weight, the crosslinking effect will only become saturated.
Furthermore, as a result of having an excessively high molecular weight, film-forming properties and flexibility may be impaired, so either case is not preferable.

Furthermore, in order to improve the pigment dispersibility and adhesion to substrates of the above-mentioned fluoroolefin copolymer emulsion, it is desirable to use α,β-ethylenically unsaturated carboxylic acids as a comonomer. To exemplify only particularly representative carboxylic acids,
Unsaturated - such as (meth)acrylic acid or crotonic acid
Basic acids or their salts; or unsaturated dibasic acids such as itaconic acid, maleic acid or fumaric acid, or their half esters or salts, among others, crotonic acid is preferably used.

These may be used alone or in combination of two or more types, and it is appropriate to use them within a range of 0.5 to 4% by weight, preferably within a range of 1 to 3% by weight based on the total monomers. It is.

In particular, if such α,β-ethylenically unsaturated carboxylic acids are used in an excessively large amount exceeding 4% by weight, the water resistance and alkali resistance of the resulting film will inevitably be impaired, which is not preferable.

In addition to the various monomers listed above, various (meth)acrylic Including acid esters, various vinyl halides such as vinyl chloride or vinylidene chloride; various glycidyl group-containing compounds such as glycidyl (meth)acrylate or allyl glycidyl ether; (meth)acrylamide or N-methylol (meth) The use of amide bond-containing compounds such as acrylamide; or so-called reactive emulsifiers such as sodium vinyl sulfonate,
- There is no problem in the direction.

In order to prepare the fluoroolefin copolymer emulsion, well-known and commonly used emulsion polymerization methods may be used, and the emulsifiers and radical polymerization initiators shown below are used.

That is, first, to exemplify only particularly typical emulsifiers, alkylbenzene sulfonates,
Various anionic emulsifiers such as alkylnaphthalene sulfonates, higher fatty acid salts, alkyl sulfate ester salts, alkyl ether sulfate ester salts, or phosphate ester salts; alkylphenol ethylene oxide adducts, or ethylene oxide/propylene oxide block copolymers or cationic emulsifiers having a quaternary amino group as a hydrophilic group, such as tetraalkylammonium chloride or trialkylbenzylammonium chloride.

Also, polyvinyl alcohol, polyvinylpyrrolidone,
It is also possible to use so-called water-soluble polymeric compounds as protective colloids, such as hydroxyethylcellulose, methylcellulose, hydroxypropylcellulose, poly(meth)acrylates, or hydrolysates of α-olefin-maleic anhydride copolymers. .

It goes without saying that each of the emulsifiers and water-soluble polymer compounds listed above may be used alone or in combination of two or more types, but of these, only the use of cationic emulsifiers is effective in ionically gelling. Needless to say, special care must be taken, as there may be cases where the

By the way, the use of an emulsifier having a fluorinated alkyl group as a hydrophobic group provides good compatibility between the copolymer and the emulsifier when the resulting fluoroolefin copolymer emulsion is dried to form a film. It is particularly desirable because it is easy to form a film and the resulting film also has excellent stain resistance.

Of course, any emulsifier can be used as long as it has a fluorinated alkyl group as a hydrophobic group. Examples include fluorine thread cationic surfactants and fluorine-containing sulfobetaine type surfactants as disclosed in JP-A-58-179300.

The appropriate amount of this type of emulsifier to be used is 0.2 to 10% by weight based on the total amount of monomers.

On the other hand, the above-mentioned radical polymerization initiators are only exemplified by water-soluble catalysts such as persulfates or hydrogen peroxide; or benzoyl peroxide or t-butyl peroxybenzoate. Furthermore, it may be used in the form of a so-called redox catalyst by combining such various polymerization initiators with a water-soluble reducing agent such as sulfite, Rongalite salt, or ascorbate. Of course it's a good thing.

In addition, pHl 1 inhibitors, chain transfer agents, and the like can also be appropriately added to such emulsion polymerization systems.

The nonvolatile content of the fluoroolefin copolymer emulsion used in the present invention is suitably within the range of 20 to 60% by weight, and the average particle diameter of the copolymer emulsion is 0.03 to 60% by weight. A range of 0.30 μm is appropriate.

If it is less than 0.03 pm, the resulting film will inevitably have excellent film-forming properties and water resistance, but will tend to have poor pigment dispersibility and mechanical stability;
．． If it exceeds 30 μm, the film-forming properties and water resistance of the film tend to deteriorate, so either case is not preferable.

Next, the above-mentioned pigments are used as appropriate depending on the purpose, such as to improve the hardness of the film, hiding property, appearance by coloring, adhesion to the base material, or weather resistance. However, the appropriate amount of the pigment used is 200% or less based on the solid weight of the fluoroolefin copolymer emulsion described above.

If it is used in an excessively large amount exceeding 200% by weight, the film obtained will inevitably become porous, resulting in poor long-term durability such as water resistance, which is not preferable.

Typical examples of such pigments include titanium oxide, mica, talc, clay, precipitated barium sulfate, inorganic white pigments such as silica powder or calcium carbonate; carbon black, aluminum powder or valves; Inorganic coloring pigments such as patterns; or organic coloring pigments such as azo or phthalocyanine, and furthermore, the use of so-called dispersed pigments obtained by dispersing each of these pigments in water with an emulsifier or dispersant. is possible,
It should be selected as appropriate depending on the purpose.

In addition, when making a so-called paint using the above-mentioned fluoroolefin copolymer emulsion,
Known and commonly used dispersants, wetting agents, film forming aids, thickeners, thixotroping agents, ultraviolet absorbers, antioxidants, light stabilizers, antifreeze agents, water repellents, antifoaming agents Alternatively, there is no problem in adding various additives such as preservatives and antifungal agents, but they should be selected and used as appropriate, taking into consideration the durability of the resulting film.

Therefore, there are no particular restrictions when applying a fluoroolefin copolymer emulsion or an aqueous coating composition containing this polymer emulsion and a pigment as essential components to the various alkaline inorganic cured materials listed above. but,
It is preferable to use typical coating methods such as brush coating, roller coating, spray coating, roll coater coating, or shower coating.

At that time, for construction site construction, the minimum film forming temperature is 0.
It is desirable to use a paint that is below °C, and the coating method is as follows:
It is best to use methods such as brush, roller or spray, and for so-called factory line painting of roofing materials such as tiles, wall materials, etc. It is desirable to select and use a paint whose minimum film-forming temperature is approximately 60°C or less, preferably 50°C or less, depending on the application.As for the coating method, roll coater, roller, spray mataha shirt ring, etc. It is better to use this method.

In such factory line painting, the alkaline inorganic cured material that serves as the coating base material is often molded and painted as an alkaline seal while left uncured, but atmospheric pressure steam in the subsequent accelerated curing process is It is of course possible and particularly effective to dry the coating film using heat from curing, autoclave steam curing under pressure, heat of hydration, etc.

Regardless of whether it is for on-site construction, factory line painting, or heated forced drying line painting, drying at room temperature is
Of course - although it is a law, by some means 6
Heat drying, which is carried out in an atmosphere at a temperature of 0°C or higher, essentially 200°C or lower, improves the film-forming property or film-forming properties, making the coating film stronger and forming a layer. This is desirable in order to ensure long-term durability, to reduce blocking as much as possible, and to ensure stain resistance.

Alternatively, a fluoroolefin copolymer emulsion or an aqueous coating composition containing the copolymer emulsion and a pigment as essential components may be applied directly onto the alkaline inorganic cured product.
It may be applied in one coat or in multiple coats, or may be acrylic, acrylic-styrene copolymer,
A coating material containing a binder with good alkali resistance, such as an acrylic-urethane combination system, a silicone-acrylic combination system, an epoxy system, a urethane system, or a silicone system, is used as an undercoat, and then a top coat of these materials is applied. applying a polymer emulsion or water-based coating composition;
It may be possible to improve the weather resistance of the entire coating system.

In any of these coating systems, the dry film thickness of an aqueous coating composition containing a fluoroolefin copolymer emulsion as an essential component, or containing this copolymer emulsion and a pigment as essential components, is as follows: ,
A value of 5μ or more is suitable.

This is because if the thickness is less than 5 μm, the long-term durability of the film tends to be insufficient.

Thus, by following the method of the present invention, ultra-weather resistance as well as
A protective film of an alkaline inorganic cured product is formed that has excellent film performance such as water resistance, chemical resistance, and stain resistance.

〔Effect of the invention〕

As described above, according to the protection method of the present invention, when the alkaline inorganic cured material serving as the base material comes into contact with water or when the cured material is hydrated and cured, the alkaline substance is prevented from leaching or seeping out. In addition, it is extremely useful as it has excellent film performance such as so-called super weather resistance, which is sufficient for long-term outdoor exposure, as well as water resistance, chemical resistance, and stain resistance. A protective film can be formed.

〔Example〕

Next, the present invention will be explained by reference examples, examples, and comparative examples.
The layer will be explained in detail. In the following, all parts and percentages are based on weight unless otherwise specified.

Reference Example 1 (Example of Preparation of Fluoroolefin Copolymer Emulsion) In a stainless steel autoclave, 15 parts of Neogen RJ (an anionic emulsifier made by Daiichi Kogyo Seiyaku Co., Ltd., sodium dodecylbenzenesulfonate; active ingredient) = 60%], "Noigen EA-120J (manufactured by the same company, nonionic emulsifier consisting of polyoxyethylene nonylphenol ether, HLB = 12, active ingredient = 1
00%), 6 parts of Neugen EA-170J (same as above; however, HLB = 17), 3 parts of ammonium hydrogen carbonate, 9 parts of methacrylic acid, and 650 parts of ion-exchanged water and stirred. The mixture was homogeneously dissolved and degassed with nitrogen.

Separately, 180 parts of ethyl vinyl ether, 48 parts of Beoba 9 (persatic acid vinyl ester from Shell, Netherlands), 3 parts of 1,7-octadiene, 280 parts of liquefied hexafluoropropylene, and While 60 parts of vinyl acetate was placed in a pressure-resistant dropping tank, ethylene was pressurized into the autoclave to a pressure of 30 atm.

Raise the temperature of the autoclave to 65°C and, while stirring,
10 parts of ammonium persulfate dissolved in 90 parts of ion-exchanged water and the mixed monomers in a pressure-resistant dropping tank prepared in advance were added dropwise over a period of 6 hours, and then heated to the same temperature. The reaction was continued by holding for 2 hours.

Then, it was cooled to room temperature, and the pi of the reaction mixture was adjusted to 7.5 with 14% aqueous ammonia.

Other properties of the objective copolymer emulsion thus obtained are summarized in Table 1.

Reference Examples 2 to 5 (same as above) Target copolymer emulsions were obtained in the same manner as in Reference Example 1, except for the changes shown in Table 1. Their property values are summarized in Table 1.

Reference Examples 6 to 8 (Preparation Example of Control Copolymer Emulsion) In a four-eye flask equipped with a stirrer, thermometer, dropping funnel, and nitrogen gas inlet, 15 parts of "Neogen R" and 6 parts of "Neogen EA-1204, Part 6 “Neugen E
A-170J, 3 parts of ammonium carbonate, and 650 parts of ion-exchanged water were charged and uniformly dissolved under stirring.

Next, the temperature was raised to 70°C, and while stirring, 3 parts of a mixture of 5 parts of ammonium persulfate dissolved in 90 parts of ion-exchanged water and the monomers shown in Table 1 was added. The mixture was added dropwise over a period of time, and even after the addition was completed, the same temperature was maintained for 2 hours to continue the reaction.

Next, cool to room temperature, add 4% ammonia water and p
n was adjusted to 7.5.

Other properties of the control copolymer emulsion thus obtained are summarized in the same table.

Reference Examples 9 to 23 (Example of Preparation of Water-Based Paint Composition) Reference Examples 1 to 23
Various aqueous coating compositions were prepared by using the respective copolymer emulsions obtained in Examples 5 and 6 to 8 and blending them according to coating formulations A, B, or C as shown below.

That is, first, paint formulation A (air-drying white glossy paint formulation) is as follows, but the copolymer emulsion applied to this formulation A has a minimum film forming temperature of 40''C or less (7) I
, IV, V, Vl' and VI[I' 17)
There are only 5 types.

Water 7.
84 parts 25χ ammonia water 0.
15 “Noigen EA-120J
O,33 ethylene glycol (antifreeze agent) 7.46 "Taihe-ri R-930J [Ishihara Sangyo 41.0
0 Rutile type titanium oxide manufactured by San Nopco Co., Ltd.] "Nopco 8034J [San Nopco Co., Ltd."] 0.
Antifoaming agent made by No. 30] The above components were dispersed using a high-speed stirrer.

Copolymer emulsion (non-volatile content = 45X) 100.
Each component of 00 or more was uniformly dispersed using a stirrer. Each of the air-dry white glossy paints thus obtained had a non-volatile content of 51%, a pigment weight concentration (PWC) of 47χ, and a minimum film-forming temperature of O''C.
C and below are unified under the following standards.

Next, paint formulation B (white glossy paint formulation for forced drying by heating) is as follows, but the copolymer emulsion applied to this formulation B has a minimum film forming temperature of 30°C or higher.
, ■, Vl' and v■'.

``The process was carried out in the same manner as paint formulation A, except that the amount of Nissocizer C5-12J used was changed to 3.73 parts, which was exactly half the amount used.

Each of the thus obtained white glossy paints for forced drying has a non-volatile content of 51%, a P-C content of 47%, and a minimum film forming temperature of 20 parts at 5°C. are unified under.

Furthermore, paint formulation C (black glossy paint formulation for forced drying by heating) is as follows, but the copolymer emulsion applied to this formulation C has a minimum film forming temperature of 30°C, as in paint formulation B. 'C or higher I, ■, ■, Vl' and v■'
There are only five types.

Water 11.
5 parts copolymer emulsion (non-volatile 100.0
min = 45%) "Nopco 8034L J (previously mentioned")
0.01 "Best Side F
Each component of 0.2 or more was uniformly dispersed using a stirrer.

Each of the black glossy paints for forced drying by heating that was obtained here had a paint non-volatile content of 40% and a minimum film forming temperature of 30±5°C, which was within the unified standard.

Examples 1-3 and Comparative Examples 1 and 2 Reference Examples 9-23
Of the aqueous paint compositions obtained in , each of the air-dry white glossy paints obtained according to paint formulation A was applied onto a flexible board (substrate a) at a weight of 120 g/c-. After leaving it at room temperature for a day and night to dry, I applied a topcoat of each paint to a thickness of 80 g/cm and left it to dry at room temperature for 7 days. A piece was made.

Next, remove the other side of each test piece except for the painted side.
After sealing with a urethane-acrylic sealant, various tests were conducted as described below.

Water resistance: After being immersed in tap water for two months, the state of change in the painted surface was visually determined.

Alkali resistance: After being immersed in a 2% aqueous solution of sodium hydroxide saturated with calcium hydroxide for two months, the state of change in the coated surface was visually determined.

Freeze-thaw resistance: first soaked in tap water at 20°C
One cycle consists of holding the temperature at 40"C for 4 hours and then holding it at 40"C for 4 hours.
After 0 cycles, the state of change in the coated surface was visually determined.

Accelerated weather resistance: An accelerated test was conducted using a Sunshine Weatherometer, and the gloss retention rate (%) after each predetermined test time was measured.

Actual exposure test: After one year of outdoor exposure in Takaishi City, Osaka Prefecture, changes in the painted surface were visually judged.

The results are shown in Table 2.

Examples 4-6 and Comparative Examples 3 and 4 Reference Examples 9-23
Of the water-based paint compositions obtained in the following, each of the air-drying white glossy paints obtained according to paint formulation A was coated on the following substrate at a coating weight of 120 g/(111"). The samples were then allowed to stand at room temperature for 7 days to dry, and 5 types of test pieces were prepared.

That is, such a base material is first coated with "Acrydic A-172J" as a solvent-based sealer on a flexible board.
(Vinyl acetate-acrylic copolymer manufactured by Dainippon Ink & Chemicals Co., Ltd.) was applied at a concentration of 100 g/c and dried, and then "Lactone Jumbo" [Suzuka Paint Co., Ltd.'s spray paint for tiles],
It was obtained by applying it smoothly to a weight of 2.000 g/c and leaving it at room temperature for one week to dry.

Next, the other surfaces of each test piece except for the painted surface were sealed with a urethane-acrylic sealant, and then the same tests as in Examples 1 to 3 and Comparative Examples 1 and 2 were conducted. The results are summarized in Table 3.

Examples 7-9 and Comparative Examples 5 and 6 Reference Examples 9-23
Of the aqueous paint compositions obtained in , each of the white glossy paints for forced drying by heating, obtained according to paint formulation B,
A base material C as shown below was preheated to a surface temperature of 60"C, then coated at 120g/c- and forced to heat for 10 minutes in an atmosphere of 100°C. After drying, it was left to dry at room temperature for 7 days to prepare five types of test pieces.

By the way, base material C is a calcium silicate plate with a specific gravity of 1.45, and 100 g of "Excel Primer" [vinyl acetate-vinyl chloride copolymer manufactured by Higashinihon Toyo Co., Ltd.] as a solvent-based sealer /cm2.

Next, the other surfaces of each test piece were sealed with a urethane-acrylic sealant, leaving only the painted surface.
Various tests were conducted in the same manner.

The results are summarized in Table 4.

Examples 1O-12 and Comparative Examples 7 and 8 Reference Examples 9-
Among the aqueous coating compositions obtained in step 23, each of the black glossy coatings for forced drying by heating, obtained according to coating formulation C, was preheated to a surface temperature of 60''C on the substrate a. Where it was placed, paint it to 120g/c-,
Forced heating and drying was performed for 10 minutes in an atmosphere of 100°C.

Therefore, after leaving it at room temperature for 5 minutes, we painted each paint on top of it so that it would be Bog/cmz, and after performing forced drying under heating for 10 minutes in an atmosphere of 100°C, we left it at room temperature. The sample was left to dry for 7 days, and 5 types of test pieces were prepared.

Next, with only the painted surface of each test piece remaining, the other surfaces were sealed with a urethane-acrylic sealant, and then various treatments were performed in the same manner as in Examples 1 to 3 and Comparative Examples 1 and 2. A test was conducted.

Those results are collect, It is shown in Table 5.

1 ΣL Table 5 As is clear from the results above, according to the method of the present invention, a coating film can be formed extremely easily by drying at room temperature or by heating drying at a relatively low temperature. You can and
It is known that the resulting coating film can exhibit long-term weather resistance, water resistance, and stain resistance. Therefore, the present invention is an extremely useful method for protecting alkaline inorganic cured products. It turns out that there is a method.

Claims (1)

[Scope of Claims] 1. A method for protecting an alkaline inorganic cured product, which comprises applying a fluoroolefin copolymer emulsion as a top coat to the alkaline inorganic cured product. 2. A method for protecting an alkaline inorganic cured product, which comprises applying an aqueous coating composition containing a fluoroolefin copolymer emulsion and a pigment as a top coat to the alkaline inorganic cured product. 3. The fluoroolefin copolymer emulsion described above is obtained by emulsion copolymerization of a fluoroolefin and other monomers copolymerizable with the fluoroolefin, according to claim 1 or 2. protection methods. 4. The fluoroolefin copolymer emulsion described above contains 10 to 70% by weight of fluoroolefin and 90 to 70% by weight of fluoroolefin.
It is obtained by emulsifying and co-weighting 30% by weight of fluoroolefins and other copolymerizable monomers.
The protection method according to claim 1 or 2. 5. The fluoroolefin copolymer emulsion described above contains 10 to 70% by weight of fluoroolefin and 90 to 70% by weight of fluoroolefin.
The protection method according to claim 1 or 2, which is obtained by emulsion copolymerization with 30% by weight of vinyl ether and/or vinyl ester. 6. The above-described fluoroolefin coweight emulsion contains 10 to 70% by weight of fluoroolefin and 30 to 70% by weight of fluoroolefin.
90% by weight vinyl ethers and/or vinyl esters, 5-30% by weight α-olefins, 0.05
Emulsified co-weight of other monomers copolymerizable with fluoroolefins selected from the group consisting of ~2% by weight of crosslinkable monomers and 0.5-4% by weight of unsaturated carboxylic acids. The protection method according to claim 1 or 2, wherein the protection method is obtained by 7. The protection method according to claim 1 or 2, wherein the fluoroolefin copolymer emulsion described above is obtained by emulsion copolymerization in the presence of an emulsifier having a fluorinated alkyl group as a hydrophobic group.