JPS5946913B2 - Manufacturing method of colored cement tiles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a thickly coated colored cement tile having excellent weather resistance and other properties.

In recent years, with the shift to prefabricated housing and lower costs, the use of cement tiles has rapidly increased in place of traditional Japanese and Western tiles due to their advantages in construction and manufacturing costs, and demand is expected to continue to grow in the future. It is expected that Cement roof tiles are manufactured by mixing cement, hard fine aggregate, water, etc., forming the mixture under pressure, and curing it for a long period of time to harden it. Although such cement tiles are sometimes used as they are, in recent years they have been mostly colored to give them a more luxurious appearance. A common coloring method is to apply a colored paint made of a polymeric material to the surface of a hardened cement tile. However, such polymeric materials have the drawbacks of high baking temperatures, high raw material costs, and often cause discoloration and peeling phenomena, so they are not satisfactory. On the other hand, a colored cement with water or a white cement with colored pigments and water is applied, a colored layer is formed and cured, and then, if necessary, a transparent paint made of a polymeric material is applied on top of it. A method of painting the material to give it a luxurious feel is also being considered. However, these cases also have drawbacks such as discoloration such as efflorescence, insufficient adhesion between the cement tile and the colored layer, and problems such as cracking and peeling. Furthermore, in order to prevent efflorescence and discoloration of colored cement tiles as described above and to impart durability, a top coat such as a solvent-based paint or a water-based paint may be applied. It is difficult to prevent efflorescence unless the time after application of the topcoat is selected appropriately, and if a long period of time has passed after the topcoat is applied, distortion may occur between the colored layer and the topcoat layer, and the adhesion between the layers may deteriorate. This often results in problems such as blistering, cracking, and peeling. As mentioned above, the conventional methods of coloring cement tiles and the coating materials used have various deficiencies in terms of performance and application.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide an excellent method for applying a thick colored coating to cement roof tiles.

In particular, the present invention can be applied to uncured cement tiles such as cement tiles immediately after pressing such as plain tiles, cement tiles immediately after extrusion molding, and primary curing tiles (tiles immediately after demolding) such as utility tiles. The object of the present invention is to provide a method for forming a coating having excellent coating properties that allows the formation of a relatively thick film and allows the application of a good topcoat.

For this purpose, (A) (1
) Cement ・・・25-45 weight? ,(
Ii) Fine aggregate...50-74 important%
, (111) Colored pigment ...0.1-1
If 100 parts by weight of a mixture (a) consisting of 5 parts by weight of gourd and small amounts of various additives as necessary is applied, a colored cement coating material consisting of 5 to 30 parts by weight of water is applied, and then (1) acrylic acid or methacrylic acid is applied. Ester copolymer emulsion resin (ester has an alkyl group having 1 to 8 carbon atoms) or copolymer emulsion resin of the acrylic acid or methacrylic ester and styrene (styrene content is 30% by weight or less) Solid content... ...5 to 40 weight range (11) Bisphenol type epoxy emulsion resin and the hardening agent solid content...0 to 10 weight? , (11
1) Filler...10-85 weight? ,
0v) Cement...5-50% by weight
, (V) Coloring pigment...0.1 to 15 weight? , and further contains small amounts of various additives as necessary, and the weight ratio of [(1)+(11)]/(1v) is 0.3 to 1.
100 parts by weight of mixture (b) in the range of
A colored resin cement coating material with a viscosity of 5 to 30 poise consisting of 0 to 300 parts by weight is applied, and then the cement tile and both coatings are cured and cured at the same time. An emulsion resin (the ester has an alkyl group having 1 to 8 carbon atoms) or a copolymer emulsion resin of the acrylic acid or methacrylic ester and styrene (the styrene content is 30% by weight or less) (the minimum structure of the emulsion resin) Membrane temperature is 30~
60℃) Solid content...55-9
5 Weight gourd (Ii) filler...O~
15 weight gourd 0 [1) Coloring pigment ・・・・・・0
Production of colored cement roof tiles characterized by applying an acrylic resin emulsion paint consisting of 100 parts by weight of a mixture (c) consisting of ~15 parts by weight and a small amount of various additives as necessary and 60 to 200 parts by weight of water and drying. This is accomplished by a method.

Examples of the cement used in the colored cement coating material (4) include Portland cement, blast furnace cement, silica cement, fly ash cement, and alumina cement, but the type thereof is not particularly limited.

The appropriate fine aggregate is one with a particle size that allows 90% or more to pass through a 5wrm sieve, and includes sand, ceramic powder, silica sand,
Silica sand with fired glaze, glass beads, etc. are used.

These fine aggregates may be colored. Also,
As the coloring pigment, ordinary inorganic pigments for paints can be used, but depending on the color, organic pigments having alkali resistance and weather resistance may also be used.

For example, to color black, use carbon black, iron oxide, etc., for red, use Bengara, etc., for green, use chromium oxide, etc., for blue, use cyanine blue, etc., for white, use titanium dioxide, etc. can be exemplified. Colored cement coating material (A) is made by adding additives such as a dispersant, antifoaming agent, water reducing agent, cement setting accelerator, cement setting retarder, etc. as necessary in addition to the above ingredients, and dispersing these in water. It is something that

The above colored cement coating material (4) is (1) Cement 25-4
5 weight? , particularly preferably 30 to 35 weight 70, (11
Potato aggregate 50-74 weight? , 011 color pigment 0.1-15
Weight e, and a mixture consisting of a small amount of additives if necessary (
a) 100 parts by weight and 5 to 30 parts by weight of water;
Within this range, a coating film with good coating workability and excellent physical properties such as adhesion and hardness can be obtained.

Next, acrylic acid, which is a component constituting the acrylic acid or methacrylic acid ester copolymer emulsion resin used in the colored resin cement coating material (B), has 1 to 8 carbon atoms.
Alkyl ester monomer, methacrylic acid carbon number 1
Typical alkyl esters of the alkyl ester monomers 8 to 8 include methyl, ethyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, benzyl, propyl, isopropyl, Sec-butyl, and the like.

Esters having 9 or more carbon atoms may generate a gel during emulsion polymerization, or the emulsion particles may become highly hydrophobic, making them unsuitable for use as emulsion resins for mixing with cement. Copolymer emulsion resins of these acrylic acid (or methacrylic acid) esters and styrene are also used, but styrene is used at 30% by weight? If it is used in excess of this amount, the weather resistance of the resulting emulsion coating film will be significantly reduced, making it undesirable for use as an outdoor emulsion resin that requires durability. If necessary, add several weights of functional monomers such as acrylic acid, methacrylic acid, and 2-hydroxylethyl methacrylate. Copolymerization is also possible. Since the acrylic acid (or methacrylic acid) ester copolymer emulsion resin or the copolymerization emulsion resin of acrylic acid (or methacrylic acid) ester and styrene used in the present invention is mixed with cement,
It is preferable to have alkali resistance and excellent cement mixing stability. For this purpose, ethers such as polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl ether, sorbitan fatty acid ester, polyester etc. are used as emulsifiers during emulsion polymerization. Esters such as oxyethylene sorbitan fatty acid ester and polyoxyethylene acyl ester; Nonionic surfactants such as oxyethylene-oxypropylene block polymers and fatty acid monoglycerides are used alone or in combination with anionic surfactants. In this case, it is necessary to use a large amount of nonionic surfactant and a small amount of anionic surfactant. Advantageously, the molecular weight of these acrylic emulsion resins is from 50,000 to 300,000, preferably from 100,000 to 200,000. These resins have a solid content of 5 to 40% by weight in the above mixture (b). It is blended in the proportion of If the weight of the resin is less than 5% by weight, the concentration of the colored resin in the cement coating material composition will be too low, and the surface of the coating formed by the resin floating to the surface due to the difference in specific gravity between the filler, cement, and colored pigment will be porous. Because of the lack of density, efflorescence is likely to occur, and furthermore, because the resin component is small, the coating lacks flexibility and tends to cause cracks and peeling phenomena in the coating film after a long period of time.
Furthermore, when applying a topcoat over it, if the time until the topcoat is long, free alkaline components in the cement can react with carbon dioxide in the air, and the resulting oxides will adhere to the topcoat. This will lead to a decline in sexuality. On the other hand, resin weighs 40? If it exceeds this, curing of the cement and curing of the resin will be delayed, and sufficient strength of the coating film will not be obtained, resulting in a decrease in water resistance of the coating film. Is the preferred blending ratio of resin 10-30% by weight? It is. The bisphenol type epoxy emulsion resin used in the colored resin cement coating material (B) of the present invention is an aromatic diglycidyl ether obtained from bisphenol A and epichlorohydrin and has an average molecular weight of 350.
~1000 resin is made into a water-dispersed type using an emulsifier.

Furthermore, as curing agents for bisphenol type epoxy emulsion resins, those commonly used as curing agents for epoxy resins can be used, but in particular diamines or diamine derivatives, dibasic acids or dibasic acid derivatives, etc. Polyamide resins obtained by polycondensation are preferred.

It is not necessarily necessary to add bisphenol type epoxy emulsion resin and its curing agent to the colored resin cement coating material (B), but in order to improve coating performance such as adhesion, 1 to 10% by weight of the above mixture (b) is added. It is preferable to use a certain amount.

In addition, 10 weight? Exceeding this is not appropriate because the weather resistance of the formed coating film will be markedly reduced. Further, it is appropriate to use the curing agent in an amount of 0.8 to 1.2 equivalents based on the epoxy group of the epoxy resin. The fillers used in the colored resin cement coating material (B) of the present invention include calcium carbonate, barium sulfate, magnesium carbonate, talc, clay,
An example is silica sand.

This filler is added to improve the brittleness of the coating film, increase its weight, and to float the above resin components to the coating surface due to the difference in specific gravity while the composition still maintains fluidity after coating. Particles having a large specific gravity and a particle size of 50 to 1000 μm, preferably 50 to 100 μm are used. The amount of filler in the above mixture (b) is 10 to 85% by weight. It is blended in the proportion of This is because within this range, the effect of floating the resin component and the effect of improving the denseness, brittleness, durability, etc. of the coating film are large, and more preferably 4.
0-80 weight? It is blended. Examples of the cement used in the colored resin cement coating material (Company) of the present invention include those similar to the cement used in the colored cement coating material (4) above, but the type thereof is not particularly limited.
The amount of cement in the above mixture (b) is 5 to 50% by weight?
It is blended in the proportion of 5 weight of cement? If it is less than that, the coating film hardness will not be sufficiently improved. On the other hand, cement is 50
If it exceeds % by weight, the water necessary for hardening the cement will not be sufficiently supplied and the hydration reaction will not proceed sufficiently, making it impossible to obtain a dense and hard coating film, which tends to cause efflorescence and become brittle. The colored pigment used in the colored resin cement coating material (B) of the present invention includes the colored resin cement coating material (B) described above.
Examples include the same colored pigments as used in 4).

The amount of color pigment in the above mixture (b) is 0.1 to 15% by weight? By blending within this range, sufficient coloring can be achieved. In addition, colored resin cement coating material (B
), various additives can be added as necessary. Examples include dispersants, antifoaming agents, thickeners, preservatives, antifungal agents, and film-forming aids to improve pigment dispersibility, coating workability, storage stability, film-forming properties, etc. I can do it. Furthermore, the above mixture (b) used for colored resin cement coating material
The sum of the solid content of (1) acrylic acid (or methacrylic acid) ester copolymerized emulsion resin or copolymerized emulsion resin of acrylic acid (or methacrylic acid) ester and styrene and (Ii) the solid content of epoxy emulsion resin. and 0v [weight ratio with ment is [(1) + (11)]
/0V)=0.3-1.

If this ratio is less than 0.3, the weather resistance of the coating film
Adhesion deteriorates and efflorescence occurs, making it impossible to form a thick film with good coating performance.On the other hand, if this ratio is greater than 1, the coating film has poor density and hardness. is insufficient, making it impossible to form a thick film. The colored resin cement coating material is made by blending 30 to 300 parts by weight of water to 100 parts by weight of the above mixture (b) to give a coating viscosity of 5 to 30 poise.

This is because within this range, cement hardening and painting workability are good. Next, the emulsion resin used in the nacrylic resin emulsion paint used as the top coat in the present invention (O) is the acrylic acid or methacrylic acid ester copolymer emulsion resin used in the colored resin cement coating material (8) (ester is carbon number 1 to 8 alkyl groups) or a copolymer emulsion resin of acrylic acid or methacrylic acid ester and styrene (styrene content is 30% by weight or less).

However, since the emulsion resin is used for top coating, it is particularly preferable that the emulsion resin has a minimum film forming temperature (MFT) of 30 to 60°C. If the MFT is lower than 30°C, contamination such as adhesion of dust during the summer season will be significant, while if it is higher than 60°C, the film forming properties will be insufficient and cracks will easily occur, which is not suitable. The present inventors have developed emulsion resins that are typically used in the coating industry, such as vinyl acetate resins, vinyl acetate-acrylic resins, ethylene monovinyl acetate resins, and styrene-butadiene emulsion resins. We also investigated emulsion resins, but found that the former had poor weather resistance and alkali resistance and also lacked long-term durability, while the latter had poor weather resistance and was not suitable for the present invention.

The emulsion resin is blended in the above mixture (c) at a solid content of 55 to 95 weight e.

As the filler used in the acrylic resin emulsion coating V+<O, extender pigments such as calcium carbonate, barium sulfate, magnesium carbonate, talc, and clay can be used. Is the filler present in the above mixture (c) in an amount of 0 to 15% by weight? It is blended in the proportion of Further, as the colored pigment, inorganic pigments and organic pigments similar to those used in the above-mentioned colored resin cement coating material (B) can be used.

The coloring pigment is blended in the above mixture (c) in a proportion of 0 to 15% by weight. If the amount of filler or coloring pigment exceeds the above range, the gloss of the finished coating will decrease and the efflorescence of the coating will be prevented. This is not preferable because it reduces effectiveness.

The acrylic resin emulsion paint (C) further contains a dispersant, preservative, anti-mold agent, ultraviolet absorber, antifoaming agent,
Additives such as film-forming aids are used. Acrylic resin emulsion paint used in the present invention (O is the above mixture (c)
) 60 to 200 parts by weight of water is blended to 100 parts by weight. Hereinafter, the method for manufacturing colored cement tiles of the present invention will be explained. First, the colored cement coating material (4) is applied to the surface of an uncured cement tile by a conventional coating method such as spray coating, roller coating, flow coating, etc.

The dry film thickness is 50 μ or more, preferably 200 to 20
Let it be 00μ. The cement tiles to be coated include tiles immediately after press molding, tiles immediately after extrusion molding, and uncured tiles that have been primarily cured for demolding, and a good coating can be applied to these tiles. After applying the colored cement coating material (4), preferably after it is dry to the touch, the colored resin cement coating material (3) is applied again in the same manner. The dry film thickness is 10 to 1000μ, preferably 80 to 150μ.
Next, the cement tile, the colored cement coating material (4) coating, and the colored resin cement coating material (B) coating are simultaneously cured and cured.

Examples of curing methods include the following methods, and any one or a combination of these methods may be used. (1) Natural curing (natural curing and hardening in an atmospheric atmosphere), (2) Underwater curing (immersion in water at a temperature of 5 to 30°C for 2 hours or more and further natural curing as necessary), (3) Steam Curing (steam curing for 2 hours or more, preferably 10 hours or more in an atmosphere with a temperature of 30 to 60° C. and a humidity of 70 to 100%, and further curing by natural curing or autoclave curing as necessary). Pretreatments for these curing methods in the method of the present invention include the following, which are not necessarily necessary in the case of natural curing.
(1) Colored cement coating material (4) and colored resin cement coating material (available) are applied to uncured cement tiles, and after drying to the touch 60~
A method of heating and drying in a 100° C. atmosphere for 5 to 60 minutes, followed by natural curing, water curing, or steam curing as described above.

In this method, it is necessary to heat-dry the coating after it is dry to the touch, and if it is not dry to the touch, cracks may occur on the surface of the coating film, which is not preferable.

If the ambient temperature is 100℃ or higher and the heating drying time exceeds 60 minutes, the moisture required for cement hardening will decrease significantly.
The adhesion of the paint film is significantly reduced. Also, the ambient temperature is 60
If the heat drying time is less than 5 minutes at a temperature below .degree. C., the acrylic emulsion resin film will not be formed sufficiently, so if it is cured in water, the coating will flow. Furthermore, since the applied uncured cement tiles are cured naturally or in water, it is not desirable to stack the tiles vertically as it may cause blocking. (2) Colored cement coating material (.A) and colored resin cement coating material (B) are applied to uncured cement tiles, and after being left in an atmosphere of 30 to 50°C for 1 to 3 hours, the above-mentioned natural curing, water curing, and steam How to take care of yourself.

This method has the characteristic that the coated film can be heated and dried without drying to the touch, and if the ambient temperature exceeds 50° C., cracks are likely to occur on the surface of the coated film.

Furthermore, if the time exceeds 3 hours at an ambient temperature of 50° C., the amount of moisture necessary for curing the cement will be significantly reduced, and the adhesion of the coating will be significantly reduced. Furthermore, if the ambient temperature is less than 30° C. and the drying time is less than one hour, the acrylic emulsion resin coating will not be formed sufficiently, so if the coating is cured in water, the coating will flow. Alternatively, it is not preferable to stack the tiles vertically in order to naturally or underwater cure the uncured cement tiles that have been applied, as this will cause blocking. (3) Colored cement coating material (4) and colored resin cement coating material (l) are applied to uncured cement tiles, and after being left in the atmosphere for 3 hours or more, it is possible to leave it in the atmosphere for water curing and steam curing. If the time is less than 3 hours, the coating of the acrylic emulsion resin and cement will not be sufficiently formed, and the coating will flow out when cured in water.

In this way, after curing the cement tiles, colored cement coating material (4) coating film, and colored resin cement coating material (day coating film),
Apply acrylic resin emulsion paint (O) using the same method to a dry film thickness of 15 to 100 μm, and dry naturally or forcefully at a temperature of 60° C. or lower.

In addition, heating the surface temperature of the tile to 30 to 80℃ before applying acrylic resin emulsion paint (0) can accelerate the drying of the acrylic resin emulsion paint (0) and prevent wrinkles. Desirable because it is possible.

As described above, according to the method of the present invention, a thick colored coating film with excellent adhesion, dense and hard can be obtained, and efflorescence can be prevented, and long-term durability against water, heat and ultraviolet rays can be obtained. It is possible to obtain a good coating film that does not flow or peel even under sunlight conditions in summer.

Furthermore, since the coating film can be cured at the same time as the cement tile body, there is also the advantage that the manufacturing process for cured cement tiles can be shortened. The present invention will be explained below with reference to Examples.

In addition, "parts" in the examples are "parts by weight." Example 1
~4 34 parts of white cement, 6 parts of fine aggregate (silica sand with a grain size of 1Tm or less)
0 parts iron oxide yellow, 5 parts iron oxide yellow, 1 part Bengara and 10 parts water to a dry film thickness of about 1.5 wm.
Spray paint the uncured colored cement tile surface, then dry to the touch and apply the colored resin cement coating material shown in Table 1 to a dry film thickness of approximately 1.
It was spray coated to a thickness of 00μ.

The cement tiles and both coatings were then cured using the curing method shown in Table 2.

In addition, in the table, natural curing is left in the air for 10 days, underwater curing is left in the air for 1 day, immersed in 20℃ water for 1 day, then left in the air for 1 week, and steam curing is left in the air for 3 hours. temperature 3
The test was carried out under conditions of standing at 5° C. and 90% humidity for 15 hours. After curing, the surface temperature of the colored cement tile was heated to about 55°C, and the coating paint shown in Table 1 was spray-painted to a dry film thickness of about 30μ, heated at 80°C for 15 minutes, and then allowed to cool. Colored cement roof tiles were manufactured.

The results of the adhesion, accelerated efflorescence test, freeze-thaw cycle test, and accelerated weather resistance test of the obtained colored cement tiles are shown in the lower part of Table 2. The test method and evaluation were performed as follows. (1) Adhesion test method: 2Tvn cellophane tape peeling test of coating film Evaluation: ◎
...50/501○...49/50~26/50,
×...25/50 or less (2) Efflorescence acceleration test Test method: In saturated slaked lime atmosphere [5°C x 16 hours → 2
0°C x 8 hours] 20 cycle evaluation: ◎... No abnormality at all, ○... Only a few abnormalities, ×... Fully abnormal, (3) Freeze-thaw cycle test Test method: [-20 ℃ x 16 hours freezing → room temperature x 8 hours] 35 cycle evaluation: ◎... No abnormality at all, O... Only some abnormalities present, ×... Fully abnormalities (cracks present) (4) Accelerated weathering Test method: Sunshine Carbon 2000 hours irradiation evaluation: ◎... No abnormality at all, O... Only some abnormalities present, ×... Fully abnormal (with yoking) Evidently from Table 2 The colored cement roof tiles manufactured by the method of the present invention in the Examples had excellent film-forming performance.

On the other hand, in Comparative Example 1, which used a colored resin cement coating material containing a resin with a high styrene content as an acrylic emulsion resin and a top coating, poor weather resistance was obtained.

Furthermore, in Comparative Example 2, in which a colored resin cement coating material with a high cement content was used, poor efflorescence properties were obtained.

Furthermore, in Comparative Example 3, which used a colored resin cement coating material and a top coat containing a vinyl acetate emulsion resin instead of an acrylic emulsion resin, poor weather resistance and efflorescence properties were obtained.

Claims (1)

[Claims] 1. On the surface of the uncured cement tile (A) (i) cement...25 to 45% by weight,
(ii) Fine aggregate...50 to 74% by weight, (ii
i) Colored pigment: A colored cement coating material consisting of 100 parts by weight of a mixture of 0.1 to 15% by weight and further small amounts of various additives as necessary and 5 to 30 parts by weight of water is applied, and then (B) (i) Acrylic acid or methacrylic acid ester copolymer emulsion resin (ester has an alkyl group having 1 to 8 carbon atoms) or copolymerization emulsion resin of the above acrylic acid or methacrylic acid ester and styrene (styrene content is 30% by weight or less) Solid content: 5 to 40% by weight, (ii) Solid content of bisphenol-type epoxy emulsion resin and curing agent: 0 to 10% by weight, (iii)
) Filler: 10-85% by weight, (iv) Cement: 5-50% by weight, (v) Coloring pigment...
...0.1 to 15% by weight, and further contains small amounts of various additives depending on the weight, and [(i) + (ii)] / (iv
) and 30 to 300 parts by weight of water.
After applying a 0 poise colored resin cement coating material and curing and curing the cement tile and both coatings at the same time, (C) (
i) Acrylic acid or methacrylic acid ester copolymer emulsion resin (ester has an alkyl group having 1 to 8 carbon atoms) or copolymerization emulsion resin of the acrylic acid or methacrylic acid ester and styrene (styrene content is 30% by weight or less) ) (The minimum film forming temperature of the emulsion resin is 30 to 60°C) Solid content...
55-95% by weight, (ii) filler...0-1
Apply an acrylic resin emulsion paint consisting of 100 parts by weight of a mixture of 5% by weight, (iii) colored pigment...0 to 15% by weight, and further small amounts of various additives as necessary, and 60 to 200 parts by weight of water. A method for producing a colored cement tile, which comprises drying the colored cement tile. 2. Claims characterized in that the curing agent that is a component of the colored resin cement coating material (B) is a polyamide resin, and the amount used is 0.8 to 1.2 equivalents of the epoxy emulsion resin. 1. The method for producing a colored cement tile according to item 1. 3. The method for producing colored cement tiles according to claim 1, characterized in that the acrylic resin emulsion paint (C) is applied after the cement tiles are heated to a surface temperature of 30 to 80°C.