JP4340146B2 - Method for producing stain-resistant coated substrate - Google Patents

Description

  The present invention relates to a method for producing a stain-resistant coated substrate that can be suitably used when forming the outer wall, roof, or other structure of a building.

In recent years, a structural material for forming an outer wall of a building, a roof, other structures, and the like has been subjected to a treatment for imparting contamination resistance from the viewpoint of emphasizing urban appearance. As such a process, for example, a process using titanium oxide (TiO ₂ ) can be cited. In this treatment, a coating film containing titanium oxide is applied to the surface of the structural material to form a coating film 1, and the coating film 1 is intended to ensure contamination resistance. And the coating film 1 formed in this way can be divided into the following two types.

  FIG. 8A shows an example of a coating film 1 of a type called a one-layer type. This coating film 1 is formed as follows. That is, a paint containing titanium oxide is directly applied to the surface of a pre-coated metal plate (PCM) as the base material 3 to form a titanium oxide layer having a thickness of about 10 μm or more. Thus, the coating film 1 consisting of one layer of the titanium oxide layer can be formed on the pre-coated metal plate, and contamination resistance can be obtained by the titanium oxide layer, and nitrogen oxide (NOx) or the like can be obtained. It is also possible to decompose the harmful gas (see, for example, Patent Document 1).

On the other hand, FIG.8 (b) shows an example of the coating film 1 of the type called a two-layer type. This coating film 1 is formed as follows. First, a coating made of an organically modified silica resin or the like is applied to the surface of the precoated metal plate that is the base material 3 to form the protective layer 10 having a thickness of about 1 μm. Next, a coating containing titanium oxide is applied to the surface of the protective layer 10 to form a titanium oxide layer having a thickness of about 1 μm. In this way, the coating film 1 composed of two layers of the titanium oxide layer and the protective layer 10 can be formed on the precoated metal plate, and contamination resistance can be obtained by the outer titanium oxide layer (for example, , See Patent Document 2).
JP 2001-81412 A (Claims) Japanese Patent No. 3038599 (Claims, Fig. 1)

  Titanium oxide decomposes dirt such as organic matter by being activated by receiving ultraviolet rays (UV) of sunlight, but as shown in FIG. If the titanium oxide layer is formed directly on the surface, the surface of the pre-coated metal plate may be decomposed and the titanium oxide layer may be peeled off. Therefore, in the above-described one-layer type coating film 1, by forming the titanium oxide layer as thick as about 10 μm, ultraviolet rays do not reach the titanium oxide existing in the vicinity of the precoated metal plate, and this oxidation is performed. Titanium activation is suppressed. However, if the titanium oxide layer is formed thickly, the amount of titanium oxide used increases accordingly, so that it is not possible to secure sufficient adhesion of the titanium oxide layer to the precoated metal plate.

  On the other hand, as shown in FIG. 8 (b), in the above-mentioned two-layer coating film 1, the protective layer 10 is not decomposed by titanium oxide and has adhesion to the precoated metal plate as the base material 3. Since a high layer is used and this is interposed between the titanium oxide layer and the precoat metal plate, the precoat metal plate can be protected by the protective layer 10 so that the precoat metal plate is not decomposed by titanium oxide, The adhesion of the titanium oxide layer to the precoated metal plate can be ensured through the protective layer 10. However, when the two-layer type coating film 1 is formed as compared with the single-layer type coating film 1, the number of steps increases and the manufacturing cost increases accordingly.

  In addition, any type of coating film 1 does not provide sufficient contamination resistance for a large amount of titanium oxide used, and on the contrary, the amount of titanium oxide used is large, so that the coating film 1 is likely to crack. It has become.

  The present invention has been made in view of the above points, and the stain resistance of the coating film is good over a long period of time, and the adhesion of the coating film to the substrate can be obtained over a long period of time. It aims at providing the manufacturing method of a pollution paint base.

The method for producing a stain-resistant coated base material according to claim 1 of the present invention includes at least titanium oxide and silica among inorganic compounds 2 selected from titanium oxide, zinc oxide, tin oxide, silica, and glass fiber. An inorganic clear paint or inorganic enamel paint 5 is applied to the surface of the substrate 3 and cured to form a coating film 1, and then the exposed area of the inorganic compound 2 on the surface of the coating film 1 is increased. The heat treatment is performed on the surface of the coating film 1 .

The method of producing stain resistant coated substrate in accordance with claim 2 of the present invention, in claim 1, wherein the content of the inorganic compound 2 is 10 wt% or more of the coating film 1 total amount Is.

  The method for producing a contamination-resistant coated substrate according to claim 3 of the present invention is the method according to claim 1 or 2, wherein the heat treatment is at least one or two selected from flame treatment, plasma treatment, and corona discharge treatment. The above processing is performed.

The method for producing a stain-resistant coated substrate according to claim 4 of the present invention is characterized in that in any one of claims 1 to 3, a flame treatment of 5 to 250 kJ / m ² / min is performed as the heat treatment. To do.

  According to claim 5 of the present invention, in any one of claims 1 to 4, the method for producing a stain-resistant painted base material uses any one of a metal material, a plastic material, wood, mortar, and stone as the base material 3. It is characterized by this.

  According to the method for producing a stain-resistant coated substrate according to claim 1 of the present invention, the stain resistance of the coating film is good over a long period, and the adhesion of the coating film to the substrate is also long-term. It can be obtained high. And the function which each inorganic compound has can be provided to a coating film by combining and using a multiple types of inorganic compound.

  According to the method for producing a stain-resistant coated substrate according to claim 2 of the present invention, the function of the inorganic compound can be sufficiently imparted to the coating film and cracks can be prevented from occurring in the coating film. It is something that can be done.

  According to the method for producing a contamination-resistant coated substrate according to claim 3 of the present invention, hydrophilicity can be easily imparted to the surface of the coating film. In addition, when an inorganic compound such as titanium oxide is contained in the coating film, such an inorganic compound can be easily exposed on the surface of the coating film.

  According to the method for producing a contamination-resistant coated substrate according to claim 4 of the present invention, hydrophilicity can be imparted to the surface of the coating film more easily. Moreover, when an inorganic compound such as titanium oxide is contained in the coating film, such an inorganic compound can be more easily and largely exposed on the surface of the coating film.

  According to the method for producing a stain resistant coated substrate according to claim 5 of the present invention, since there are a wide variety of substrates, a suitable stain resistant coated substrate can be obtained according to the application. is there.

  Embodiments of the present invention will be described below.

In the present invention, the inorganic clear paint refers to a paint prepared by blending the inorganic compound 2 described later and does not contain a pigment. Examples thereof include colloidal silica paint and colloidal titania paint, and precursors thereof. Etc. This precursor refers to organic silicon, organic titanium, or the like, and substantially forms a colloidal silica paint or a colloidal titania paint when the coating film 1 is formed. For example, the precursors of colloidal silica paints include tetraalkoxysilanes (more specifically, tetraethoxysilanes, tetramethoxysilanes, tetraisopropoxysilanes, tetraptoxysilanes, etc.), silanols, siloxanes Examples of precursors for colloidal titania coatings include titanium alkoxide compounds, titanium chelate compounds, titanium acetate compounds, titanium chloride (TiCl ₄ ), and titanium sulfate (Ti (SO ₄ ) _2. And the like. Here, since it is difficult to form the coating film 1 with only colloidal silica or colloidal titania, the resin component 4 such as acrylic resin, amino resin, alkyd resin, and epoxy resin is used as a binder in the inorganic clear coating. Is blended in a small amount.

Further, in the present invention, the inorganic enamel paint refers to a paint prepared by blending the inorganic compound 2 described later and containing a pigment, such as chromium oxide (Cr ₂ O ₃ ) or iron oxide (Fe _2). Examples thereof include pigments such as O ₃ ) blended in the above-described colloidal silica paint, colloidal titania paint, etc., and their precursors. A small amount of resin component 4 such as an acrylic resin, an amino resin, an alkyd resin, or an epoxy resin is blended in the inorganic enamel paint as a binder.

If necessary, an aggregate such as alumina (Al ₂ O ₃ ) or calcium carbonate (CaCO ₃ ) may be added to the inorganic clear coating or inorganic enamel coating 5 in the present invention. In addition, as an inorganic clear coating material or the inorganic enamel coating material 5, what is marketed can also be used. For example, “Poserin # 200” manufactured by Toupe Co., Ltd. can be mentioned. Moreover, in order to make it easy to apply | coat, you may dilute the inorganic clear coating material or the inorganic enamel coating material 5 with solvents, such as water, methanol, and ethanol, as needed.

In the present invention, the inorganic compound 2 is at least one selected from titanium oxide, zinc oxide (ZnO), tin oxide (SnO ₂ ), silica, and glass fiber. Of these inorganic compounds 2, titanium oxide, zinc oxide, and tin oxide are also called photocatalysts. And when the inorganic clear coating material or the inorganic enamel coating material 5 is prepared using such an inorganic compound 2, the function which the inorganic compound 2 has can be provided to the coating film 1. FIG. In particular, when a plurality of types of inorganic compounds 2 are used in combination, the function of the plurality of types of inorganic compounds 2 can be imparted to the coating film 1. Here, when the function which the inorganic compound 2 has is demonstrated concretely, when said photocatalyst is used as the inorganic compound 2, for example, in addition to further improving the stain resistance of the coating film 1, it is antibacterial. And deodorant properties can be improved. Moreover, when using silica, the abrasion resistance of the coating film 1 can be improved. Moreover, when using glass fiber, the intensity | strength of the coating film 1 can be improved. Furthermore, when these inorganic compounds 2 are used in combination, a synergistic effect can be obtained. Moreover, unless it deviates from the objective of this invention, the antibacterial property of the coating film 1 is improved using antibacterial agents, such as a silver compound, or the deodorizing property of the coating film 1 is improved using deodorizing agents, such as diatomaceous earth. Can be. Titanium oxide can be roughly divided into inactive titanium oxide whose surface is coated with alumina and active titanium oxide whose surface is not coated. In the present invention, active titanium oxide is used. Is preferred.

  Here, with respect to the total amount of the coating film 1 (solid content of the inorganic clear coating or the inorganic enamel coating 5), the inclusion of at least one or two or more inorganic compounds 2 selected from titanium oxide, zinc oxide and tin oxide The amount is preferably 10 to 95% by weight. When this content is less than 10% by weight, the function of the inorganic compound 2 may not be sufficiently imparted to the coating film 1. On the other hand, when the content is more than 95% by weight, the content of the resin component 4 such as an acrylic resin serving as a binder is relatively decreased, and thus the adhesion of the coating film 1 to the base material 3 is reduced. There exists a possibility that it may fall or a crack may generate | occur | produce in the coating film 1 and it may become easy to break. In particular, when titanium oxide is used as the inorganic compound 2, the content of titanium oxide is 10 to 60% by weight with respect to the total amount of the coating film 1 (solid content of the inorganic clear coating or the inorganic enamel coating 5). preferable. If the content of titanium oxide is less than 10% by weight, the degree of heat treatment described later (for example, the strength of flame treatment) must be increased in order to sufficiently impart stain resistance to titanium oxide to the coating film 1. The energy cost may increase. On the other hand, when the content of titanium oxide is more than 60% by weight, the adhesion of the coating film 1 to the substrate 3 may be reduced, or cracks may be generated in the coating film 1 and may be easily broken.

  As described above, in the present invention, the inorganic clear paint 5 made of silica, which is the inorganic compound 2, and the acrylic resin, which is the resin component 4, can be used. In such an inorganic clear coating material 5, it is preferable that the blending ratio of silica is large. This is because sufficient anti-staining properties can be imparted to the coating film 1 and a high protective effect of the coating film 1 can be obtained. However, as already described, since it is difficult to form the coating film 1 only with silica, an organic substance such as an acrylic resin is blended as a binder. If the blending ratio of the acrylic resin is increased at this time, the coating film 1 may be easily decomposed when titanium oxide is further blended as described later. Therefore, when using the coating material which consists of a silica and an acrylic resin as the inorganic clear coating material 5, it is preferable that these compounding ratios are 95: 5-10: 90 by weight ratio.

  In the present invention, various materials can be used as the substrate 3. For example, examples of the base material 3 include metal materials, plastic materials, wood, mortar, and stone materials. More specifically, examples of the metal material include an aluminum plate, an iron plate, a galvanized steel plate, a pre-coated metal plate (for example, a fluororesin-coated steel plate, a polyester-coated steel plate, etc.). Moreover, an acrylic board etc. can be illustrated as a plastic material. Moreover, a veneer board etc. can be illustrated as a timber. Thus, since the types of base materials 3 are abundant, a suitable stain-resistant coated base material can be obtained according to the application. In addition, as the base material 3, not only a plate-shaped thing but the thing processed into various shapes can be used.

  And a pollution-resistant coating base material can be manufactured as follows. First, as shown in FIG. 1 (a), an inorganic clear coating 5 (for example, a coating composed of silica and acrylic resin as described above) is applied to the surface of the substrate 3 and cured to form a coating film 1. . Thereafter, by subjecting the surface of the coating film 1 to heat treatment, a stain-resistant coated base material as shown in FIG. 1B can be produced. 1 (a) and 1 (b), the exposed area of the silica, which is the inorganic compound 2, on the surface of the coating film 1 is larger after the heat treatment than before the heat treatment. It can be seen that the exposed area of the acrylic resin as the resin component 4 is small. As described above, the exposed area of the acrylic resin, which is an organic substance, is reduced, so that dirt such as an organic substance is difficult to adhere. Moreover, since many OH groups are introduced to the surface of the coating film 1 after the heat treatment to impart hydrophilicity, even if dirt adheres, the dirt does not adhere firmly and is easily washed away. Thus, the stain resistance of the coating film 1 can be maintained well over a long period of time. Further, in the present invention, good contamination resistance can be obtained even if the inorganic compound 2 such as titanium oxide is not contained in the coating film 1, so that the conventional one-layer type shown in FIG. Compared with the coating film 1, the adhesiveness with respect to the base material 3 of the coating film 1 can be maintained favorable over a long period of time. However, the present invention does not exclude the use of the inorganic compound 2 such as titanium oxide. If inorganic compound 2 such as titanium oxide is used, it is possible to easily improve characteristics such as contamination resistance, but the present invention greatly reduces the amount of inorganic compound 2 such as titanium oxide used than before. This is technically significant in that the processability of the coating film 1 can be improved, and is advantageous over conventional techniques.

  Here, also in the present invention, when titanium oxide is used as the inorganic compound 2, two types of coating film 1 can be formed as in the conventional case, but the coating film 1 is formed thinner than the conventional one. can do. That is, in the case of a type called a one-layer type shown in FIG. 8A, when a precoated metal plate is used as the base material 3, the thickness of the coating film 1 can be reduced to 6 μm. This is because the amount of titanium oxide used can be reduced. Moreover, when using the metal plate which is not precoated as the base material 3, the thickness of the coating film 1 can be made thin to 1 micrometer. This is because the metal itself is not decomposed by the photocatalytic action of titanium oxide. On the other hand, in the case of a type called a two-layer type shown in FIG. 8B, the thickness of the coating film 1 formed on the surface of the protective layer 10 can be made thinner than 1 μm. This is because the protective layer 10 is not decomposed by the photocatalytic action of titanium oxide. In any type, if the coating film 1 is formed thick, the adhesiveness and workability may be reduced. However, in the present invention, the upper limit of the thickness of the coating film 1 is not particularly limited.

  The stain-resistant coated base material as described above can be produced either continuously or batchwise. FIG. 3 shows an example of equipment for producing a stain-resistant coated base material by a continuous method. When this production facility is used, for example, when a plate-like substrate 3 is used, a stain-resistant coated substrate can be produced as follows. A long pre-coated metal plate (plate thickness: 0.16 to 1.60 mm, plate width: 610 to 1030 mm) was used as the base material 3 while conveying this pre-coated metal plate in the longitudinal direction (conveying speed: 30 to 200 m). / Min) First, the inorganic clear coating 5 is applied to the surface of the pre-coated metal plate by a coater which is a coating machine 6. At this time, the inorganic clear coating 5 is prepared by blending titanium oxide 2b with a coating made of silica 2a and an acrylic resin. Next, the inorganic clear paint 5 is cured by passing a pre-coated metal plate coated with the inorganic clear paint or the enamel paint 5 as described above through an oven which is a dryer 7, thereby forming the coating film 1. The maximum temperature reached by the oven-precoated metal plate is set at 224 ° C., for example. The cross section of the coating film 1 at this time is schematically shown in FIG. Then, the heating means 8 heat-treats the surface of the coating film 1 while conveying the precoat metal plate in which the coating film 1 is formed in this way in the longitudinal direction. FIG. 2B schematically shows a cross section of the coating film 1 after the heat treatment. In this way, a contamination-resistant coated substrate can be produced in a continuous manner. In FIG. 3, 9 is a transport roll.

  Here, as shown in FIG. 2B, it is preferable that the inorganic compound 2 blended in the inorganic clear coating 5 is exposed on the surface of the coating film 1 by heat treatment. Since the exposed area of the acrylic resin, which is an organic material, decreases after the heat treatment (FIG. 2B) compared to before the heat treatment (FIG. 2A), dirt such as organic matter is less likely to adhere. is there. Moreover, since many OH groups are introduced to the surface of the coating film 1 after the heat treatment to impart hydrophilicity, even if dirt adheres, the dirt does not adhere firmly and is easily washed away. Thus, the stain resistance of the coating film 1 can be maintained well over a long period of time. Further, when the inorganic compound 2 is largely exposed on the surface of the coating film 1 as shown in FIG. 2B, the function of the inorganic compound 2 can be sufficiently imparted to the coating film 1. Specifically, when the silica 2a and the titanium oxide 2b are largely exposed, the exposed area of the acrylic resin as the resin component 4 can be reduced, and dirt such as organic matter is difficult to adhere, As the titanium oxide 2b is largely exposed, the area in contact with the dirt such as organic matter increases, and the photocatalytic action of the titanium oxide 2b can further improve the stain resistance of the coating film 1 and thus improve it. The stain resistance can be maintained for a considerably long time.

  In the present invention, as the heat treatment, at least one treatment selected from flame treatment (F treatment), plasma treatment, and corona discharge treatment can be performed. In any case, the surface of the coating film 1 can be heated, and thereby the hydrophilicity can be easily imparted to the surface of the coating film 1. Moreover, when the inorganic compound 2 such as titanium oxide is contained in the coating film 1, such an inorganic compound 2 can be easily exposed on the surface of the coating film 1. The frame treatment can be performed using a burner such as a curtain burner or a slit burner as the heating means 8. That is, as shown in FIG. 3, a burner is disposed on the downstream side of the oven, the opening of the burner as the heating means 8 is directed toward the coating film 1 of the base material 3, and the frame (flame) is being conveyed Is applied to the surface of the coating film 1 to perform the frame treatment. The plasma treatment can be performed using a plasma jet gun as the heating means 8. That is, as shown in FIG. 3, a plasma jet gun is disposed on the downstream side of the oven, the nozzle is directed toward the coating film 1 of the base material 3, and plasma is applied to the surface of the coating film 1 while transporting the base material 3. Plasma treatment can be performed by spraying.

Here, assuming that the amount of heat given to the coating film 1 by the heating means 8 per unit time is constant, in a continuous method, if the conveyance speed of the substrate 3 is increased, the amount of heat given to the coating film 1 of the substrate 3 is reduced. Conversely, if the conveyance speed of the base material 3 is decreased, the amount of heat applied to the coating film 1 of the base material 3 can be increased. This will be described with a specific example. When a burner (effective width: 100 mm / torch) of 110.1 kJ / min (26.3 kcal / min) (constant) is used as the heating means 8, the conveyance speed of the base material 3 on which the coating film 1 is formed is 60 m / When changed to minutes, 30 m / min, and 15 m / min, the amount of heat applied to the coating film 1 is 18.4 kJ / m ² / min (4.4 kcal / m ² / min) and 36.8 kJ / m ² / min, respectively. (8.8 kcal / m ² / min) and 73.7 kJ / m ² / min (17.6 kcal / m ² / min). That is, when the conveyance speed of the base material 3 is high, the amount of heat given to the 1 m ² coating film 1 becomes small per minute, and conversely, when the conveyance speed of the base material 3 is slow, 1 m ² per minute. The amount of heat given to the coating film 1 increases.

In particular, as the heat treatment, it is preferable to perform a flame treatment of 5 to 250 kJ / m ² / min. When the strength of the frame treatment is set as described above, hydrophilicity can be imparted to the surface of the coating film 1 more easily. In addition, when the coating film 1 contains an inorganic compound 2 such as titanium oxide, the inorganic compound 2 can be more easily and largely exposed on the surface of the coating film 1. However, if the intensity of the frame processing is smaller than 5 kJ / m ² / min, there is a possibility that the above effects cannot be obtained sufficiently. On the other hand, if the strength of the frame treatment is larger than 250 kJ / m ² / min, the coating film 1 may be carbonized or the production cost of the stain-resistant coated substrate may increase due to an increase in energy cost.

  On the other hand, according to the batch method, for example, a stain-resistant coated substrate can be produced as follows. A pre-coated metal plate (plate thickness: 0.16 to 1.60 mm, plate width: 610 to 1030 mm) previously cut into a predetermined shape is used as the base material 3, and first, with a bar coater or spray as the coating machine 6. The inorganic clear coating 5 is applied by spraying on the surface of the precoated metal plate. At this time, as the inorganic clear coating 5, a coating made of silica and an acrylic resin and titanium oxide can be used. Next, the inorganic clear coating 5 applied to the precoated metal plate is cured in an oven which is a dryer 7 to form the coating film 1. At this time, the maximum reached temperature of the precoated metal plate by the oven is set to 224 ° C., for example. A cross section of the coating film 1 thus obtained is schematically shown in FIG. 1 (a) (or FIG. 2 (a)). Thereafter, the surface of the coating film 1 thus formed on the precoated metal plate is subjected to a heat treatment by a heating means 8 such as a hand burner. The cross section of the coating film 1 at this time is schematically shown in FIG. 1 (b) (or FIG. 2 (b)). In this way, a stain-resistant coated substrate can be produced in a batch system. Even in the batch system, it is preferable to expose the inorganic compound 2 blended in the inorganic clear coating 5 on the surface of the coating film 1 by heat treatment.

  And the contamination-resistant coating base material manufactured as mentioned above has favorable contamination resistance of the coating film 1 over a long period of time, and also the adhesion of the coating film 1 to the substrate 3 over a long period of time. Since it can obtain high, it can be used suitably when forming the outer wall of a building, a roof, other structures, etc.

  Hereinafter, the present invention will be specifically described by way of examples.

[Contamination resistance of coating film]
After the product of the present invention was exposed to the outdoors for a predetermined period, the stain resistance of the coating film 1 was investigated. The exposure period is 0.5 months, 4 months, and 1 month, which will be described in this order.

(0.5 months of dirt)
As the inorganic clear paint 5, a paint made of silica and acrylic resin was used. The mixing ratio of silica and acrylic resin is 95: 5 by weight.

  In addition to the inorganic clear coating material 5 described above, an inorganic clear coating material 5 containing (active) titanium oxide was also used. The content of titanium oxide is 31% by weight with respect to the total solid content (coating film 1) of the inorganic clear coating material 5.

  That is, as the inorganic clear coating material 5, two types were used, one having a titanium oxide content of 0% by weight and one having 31% by weight.

  Further, as the base material 3 (original plate), “Sunflon” (TUV28) (plate thickness: 0.5 mm, plate width: 1000 mm) manufactured by Taiyo Steel Co., Ltd., which is a fluororesin-coated steel plate, was used.

  And the contamination-resistant coating base material was manufactured using the manufacturing equipment by a continuous system as shown in FIG. That is, the inorganic clear coating 5 was first applied to the surface of the substrate 3 with a coater while the substrate 3 was conveyed in the longitudinal direction. Next, the substrate 3 coated with the inorganic clear coating 5 was passed through an oven to cure the inorganic clear coating 5 to form the coating film 1. Then, the heat treatment was performed on the surface of the coating film 1 by the heating means 8 while conveying the base material 3 on which the coating film 1 was formed in the longitudinal direction.

  Here, as the heating means 8, ten burners (effective width: 100 mm / torch) of 110.1 kJ / min (26.3 kcal / min) (constant) were used in parallel. Then, frame processing at levels 4 to 8 was performed by changing the conveyance speed. The contents of levels 4-8 are shown below. In the following, level 0 means that no frame processing was performed. “Mpm” has the same meaning as “m / min”.

Level 0 (30 mpm, 0 kJ / m ² / min (0 kcal / m ² / min))
Level 4 (30 mpm, 36.8 kJ / m ² / min (8.8 kcal / m ² / min))
Level 5 (15 mpm, 73.7 kJ / m ² / min (17.6 kcal / m ² / min))
Level 6 (7.5 mpm, 147.3 kJ / m ² / min (35.2 kcal / m ² / min))
Level 7 (5 mpm, 221.0 kJ / m ² / min (52.8 kcal / m ² / min))
Level 8 (5 mpm, 442.0 kJ / m ² / min (105.6 kcal / m ² / min))
Level 8 frame processing is obtained by repeating level 7 frame processing twice.

  And after exposing the contamination | pollution resistant coating base material obtained by the above to the outdoors for 0.5 months, the dirt condition was investigated. Specifically, first, an exposed specimen (width 145 mm × length 200 mm) and an exposed substrate (width 145 mm × length 100 mm) were cut out from each stain-resistant coated base material. Next, an exposure test piece was attached to an inclined surface of an exposure table inclined 45 ° facing south in the outdoors and exposed for 0.5 months, while the exposed substrate was stored in an indoor storage for the same period. After 0.5 months from the start of exposure, the exposure test specimen was removed from the exposure table, and the exposed substrate was taken out of the storage. Then, without wiping the surface of the exposed test piece, the color difference between the exposed substrate and the exposed test piece (SM-5) manufactured by Suga Test Instruments Co., Ltd. based on Japanese Industrial Standard (JIS): Z-8729 ( The degree of soiling was investigated by measuring ΔL). In addition, arbitrary 5 places on the surface of the exposed test piece were selected as measurement sites, and the median value was used as a representative value. The results are shown in FIG. In FIG. 4, the horizontal axis original plate is one in which the coating film 1 is not formed. Here, when ΔL is negative (when −ΔL is positive), it indicates that the exposed test piece is darker than the exposed substrate and is dirty, and conversely, when ΔL is positive (−ΔL). Indicates that the exposed specimen is whitish and dirtyer than the exposed substrate. Therefore, the closer the ΔL is to 0, the more unexposed the test specimen is.

  As shown in FIG. 4, it is confirmed that the contamination resistance is improved by performing the frame processing. Moreover, it is confirmed that the contamination resistance is further improved by adding titanium oxide.

(4 months dirt)
As an embodiment of the present invention, the contamination resistance of the coating film 1 obtained by each heat treatment was investigated by exposing the flame treatment, corona discharge treatment, and plasma treatment to the outdoors for 4 months. . The flame treatment, corona discharge treatment, and plasma treatment will be described in this order.

(4 months dirt (1))
As the inorganic clear paint 5, a paint made of silica and acrylic resin was used. The mixing ratio of silica and acrylic resin is 95: 5 by weight.

  In addition to the inorganic clear coating material 5 described above, six types of the above inorganic clear coating material 5 containing (active) titanium oxide were used. The content of titanium oxide is 20% by weight, 37% by weight, 50% by weight, 61% by weight, 75% by weight and 88% by weight, respectively, based on the total amount of the solid content of the inorganic clear coating 5 (coating film 1).

  That is, as the inorganic clear coating material 5, a total of seven types of materials including a titanium oxide content of 0% by weight and the above six types were used.

  Further, as the base material 3 (original plate) 2, “Sunflon” (TUV28) (plate thickness: 0.5 mm, plate width: 1000 mm) manufactured by Taiyo Steel Co., Ltd., which is a fluororesin-coated steel plate, was used.

  And the contamination-resistant coating base material was manufactured using the manufacturing equipment by a continuous system as shown in FIG. That is, the inorganic clear coating 5 was first applied to the surface of the substrate 3 with a coater while the substrate 3 was conveyed in the longitudinal direction. Next, the substrate 3 coated with the inorganic clear coating 5 was passed through an oven to cure the inorganic clear coating 5 to form the coating film 1. Then, the heat treatment was performed on the surface of the coating film 1 by the heating means 8 while conveying the base material 3 on which the coating film 1 was formed in the longitudinal direction.

  Here, as the heating means 8, ten burners (effective width: 100 mm / torch) of 110.1 kJ / min (26.3 kcal / min) (constant) were used in parallel. Level 7 frame processing was then performed. The contents of level 7 are shown below.

Level 7 (5 mpm, 221.0 kJ / m ² / min (52.8 kcal / m ² / min))
And after exposing the pollution-resistant coating base material obtained with the above (with F processing) and the thing which did not carry out frame processing (without F processing) for four months, the condition of dirt was checked. investigated. The color difference (ΔL) was measured using an SM color computer “SM-5” manufactured by Suga Test Instruments Co., Ltd. as described above. The results are shown in FIG. In FIG. 5, the original plate on the horizontal axis is one in which the coating film 1 is not formed.

  As seen in FIG. 5, it is confirmed that the contamination resistance is improved when the frame processing is performed. Further, it is confirmed that the amount of titanium oxide used can be greatly reduced by performing the frame treatment.

(4 months of dirt (2))
As the inorganic clear coating material 5, a coating material composed of silica and acrylic resin and (active) titanium oxide was used. The mixing ratio of silica and acrylic resin is 95: 5 by weight. The content of titanium oxide is 31% by weight with respect to the total solid content (coating film 1) of the inorganic clear coating material 5.

  Moreover, as the base material 3, a polyester resin coated steel plate (200 mm × 300 mm × plate thickness 0.35 mm) was used.

And the contamination-resistant coating base material was manufactured with the batch system. That is, first, the inorganic clear coating 5 was applied to the surface of the substrate 3 with a bar coater. At this time, the inorganic clear coating material 5 was applied so as to have a dry weight of 15 g / m ² . Next, the inorganic clear coating 5 applied to the substrate 3 was heated to 224 ° C. to cure the inorganic clear coating 5 to form the coating film 1. Then, the base material 3 in which the coating film 1 was thus formed was cut to obtain two base materials 3 each having a size of 100 mm × 100 mm × plate thickness 0.35 mm. Of the two substrates 3 thus obtained, the coating film 1 of one substrate 3 is subjected to heat treatment by corona discharge treatment under the following conditions, and the coating film 1 of the other substrate 3 is subjected to corona discharge treatment. The heat treatment by was not performed. In the corona discharge treatment, the distance between the electrode and the substrate 3 is set to 50 mm in air reduced in pressure by a vacuum pump to 13.3 hPa (10 mmHg), and a voltage of 40,000 V is applied between them for 20 seconds. Was done.

  And after exposing the pollution-resistant coating base material (with corona discharge treatment) obtained as mentioned above and the thing which did not heat-process (without corona discharge treatment) for four months, it becomes dirty. The condition was investigated. The color difference (ΔL) was measured using an SM color computer “SM-5” manufactured by Suga Test Instruments Co., Ltd. as described above. As a result, “with corona discharge treatment” was 0.52, whereas “without corona discharge treatment” was 7.71.

  As described above, it is confirmed that when the corona discharge treatment is performed, the contamination resistance is improved.

(4 months dirt (part 3))
As the inorganic clear coating material 5, a coating material composed of silica and acrylic resin and (active) titanium oxide was used. The mixing ratio of silica and acrylic resin is 95: 5 by weight. The content of titanium oxide is 31% by weight with respect to the total solid content (coating film 1) of the inorganic clear coating material 5.

  Moreover, as the base material 3, a polyester resin coated steel plate (200 mm × 300 mm × plate thickness 0.35 mm) was used.

And the contamination-resistant coating base material was manufactured with the batch system. That is, first, the inorganic clear coating 5 was applied to the surface of the substrate 3 with a bar coater. At this time, the inorganic clear coating material 5 was applied so as to have a dry weight of 15 g / m ² . Next, the inorganic clear coating 5 applied to the substrate 3 was heated to 224 ° C. to cure the inorganic clear coating 5 to form the coating film 1. Then, the base material 3 in which the coating film 1 was formed in this way was cut in half to obtain two base materials 3 each having a size of 150 mm × 200 mm × plate thickness 0.35 mm. Of the two substrates 3 thus obtained, the coating film 1 of one substrate 3 is subjected to heat treatment by plasma treatment under the following conditions, and the coating film 1 of the other substrate 3 is subjected to heat treatment. There wasn't. The plasma treatment is performed by separating the nozzle tip of the nozzle of the plasma jet gun set to nozzle diameter: 4 mm, inter-electrode distance: 5 mm, argon flow rate: 40 L / min, current: 100 A from the above substrate 2 by 20-30 mm. This was performed by spraying plasma on the coating film 1 of the substrate 2 from the nozzle of the plasma jet gun.

  And after exposing the pollution-resistant coating base material obtained with the above (with plasma treatment) and the material without heat treatment (without plasma treatment) for 4 months, investigated. The color difference (ΔL) was measured using an SM color computer “SM-5” manufactured by Suga Test Instruments Co., Ltd. as described above. As a result, “with plasma treatment” was 0.66, whereas “without plasma treatment” was 7.53.

  As described above, it is confirmed that the contamination resistance is improved when the plasma treatment is performed.

(1 month dirt)
As the inorganic clear paint 5, a paint made of silica and acrylic resin was used. The mixing ratio of silica and acrylic resin is 95: 5 by weight.

  In addition to the inorganic clear coating material 5 described above, six types of the above inorganic clear coating material 5 containing (active) titanium oxide were used. The content of titanium oxide is 10% by weight, 20% by weight, 40% by weight, 60% by weight, 80% by weight and 90% by weight, respectively, based on the total amount of the solid content of the inorganic clear coating 5 (coating film 1).

  That is, as the inorganic clear coating material 5, a total of seven types of materials including a titanium oxide content of 0% by weight and the above six types were used.

  Further, as the base material 3 (original plate) 2, “Sunflon” (TUV28) (plate thickness: 0.5 mm, plate width: 1000 mm) manufactured by Taiyo Steel Co., Ltd., which is a fluororesin-coated steel plate, was used.

And the contamination-resistant coating base material was manufactured using the manufacturing equipment by a continuous system as shown in FIG. That is, the inorganic clear coating 5 was first applied to the surface of the substrate 3 with a coater while the substrate 3 was conveyed in the longitudinal direction. Next, the substrate 3 coated with the inorganic clear coating 5 was passed through an oven to cure the inorganic clear coating 5 to form the coating film 1. The dry weight of this coating film 1 was 15 g / m ² . Then, the heat treatment was performed on the surface of the coating film 1 by the heating means 8 while conveying the base material 3 on which the coating film 1 was formed in the longitudinal direction.

  Here, as the heating means 8, ten burners (effective width: 100 mm / torch) of 110.1 kJ / min (26.3 kcal / min) (constant) were used in parallel. And the frame process of the levels 1-5 was performed by changing a conveyance speed. The contents of levels 1 to 5 are shown below.

Level 1 (200 mpm, 5.5 kJ / m ² / min (1.3 kcal / m ² / min))
Level 2 (90 mpm, 12.1 kJ / m ² / min (2.9 kcal / m ² / min))
Level 3 (60 mpm, 18.4 kJ / m ² / min (4.4 kcal / m ² / min))
Level 4 (30 mpm, 36.8 kJ / m ² / min (8.8 kcal / m ² / min))
Level 5 (15 mpm, 73.7 kJ / m ² / min (17.6 kcal / m ² / min))
And after exposing the contamination-resistant coating base material obtained by the above and the thing which did not carry out a frame process (F process is not carried out) for one month, the condition of dirt was investigated. The color difference (ΔL) was measured using an SM color computer “SM-5” manufactured by Suga Test Instruments Co., Ltd. as described above. The results are shown in FIG.

  As shown in FIG. 6, it is confirmed that the contamination resistance is improved by performing the frame processing. Moreover, it is confirmed that the contamination resistance is further improved by adding titanium oxide.

[Coating adhesion]
The adhesiveness of the coating film 1 was investigated before exposing the product of the present invention outdoors for 4 months. Specifically, the coating film of the stain-resistant coated base material (with F treatment) obtained in the above-mentioned (4 months of dirt (Part 1)) and those without frame treatment (no F treatment). The adhesion of 1 was measured. This measurement was performed as follows. That is, first, the surface on which the coating film 1 was formed on the stain-resistant coated substrate was turned outside, and the stain-resistant coated substrate was bent and bent with a radius of curvature twice the plate thickness. Next, “cello tape (registered trademark)” manufactured by Nichiban Co., Ltd., which is a cellophane adhesive tape, was attached to the bending surface generated by this tight bending. Thereafter, the above tape is peeled off, and one piece of the coating film adhering to this tape and the portion where the above tape is adhered are visually observed using a 10-fold magnifier, and the peeling state of the coating film 1 is observed. Examined. Evaluation of this peeling condition was performed by attaching a score of 0 to 5 points in comparison with a peeling standard photograph prepared in advance. The results are shown in FIG. Here, “5 points” indicates a state where no peeling or cracking of the coating film 1 is observed, “4 points” indicates a state where no peeling of the coating film 1 is observed but cracks are observed, and “3 points” indicates a crack. In addition to the above, the state where the peeling of the coating film 1 is slightly observed, “2 points” is the state where peeling of the coating film 1 is more common than 3 points, and “1 point” is the peeling of the coating film 1 better than 2 points Each state is shown.

  As shown in FIG. 7, it is confirmed that the same degree of adhesion can be obtained both when the frame processing is performed and when the frame processing is not performed. However, if the result shown in FIG. It is confirmed that the case where the frame processing is performed is superior to the case where the processing is not performed in that the stain resistance is obtained in addition to the adhesion.

An example of embodiment of this invention is shown, (a) is a schematic sectional drawing of the coating film before heat processing, (b) is a schematic sectional drawing of the coating film after heat processing. The other example of embodiment of this invention is shown, (a) is a schematic sectional drawing of the coating film before heat processing, (b) is a schematic sectional drawing of the coating film after heat processing. It is the schematic which shows an example of the manufacturing equipment of the pollution resistant coating base material by a continuous system. It is a graph which shows the stain | pollution | contamination condition of the coating film at the time of exposing a stain | pollution resistant coating base material to the outdoors for 0.5 months. It is a graph which shows the stain | pollution | contamination condition of a coating film at the time of exposing a stain | pollution resistant coating base material outdoors for four months. It is a graph which shows the stain | pollution | contamination condition of a coating film at the time of exposing a stain | pollution resistant coating base material outdoors for one month. It is a graph which shows the adhesiveness of the coating film at the time of exposing a stain | pollution resistant coating base material outdoors for 4 months. BRIEF DESCRIPTION OF THE DRAWINGS It shows a prior art, (a) is a schematic sectional drawing of a 1 layer type coating film, (b) is a schematic sectional drawing of a 2 layer type coating film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating film 2 Inorganic compound 3 Base material 4 Resin component 5 Inorganic clear coating or inorganic enamel coating

Claims (5)

An inorganic clear paint or inorganic enamel paint containing at least titanium oxide and silica among inorganic compounds selected from titanium oxide, zinc oxide, tin oxide, silica, and glass fiber is applied to the surface of the substrate. After the coating film is formed by curing, the surface of the coating film is subjected to a heat treatment for increasing the exposed area of the inorganic compound on the surface of the coating film. . The method for producing a stain-resistant coated substrate according to claim 1, wherein the content of the inorganic compound is 10% by weight or more based on the total amount of the coating film.   The process for producing a contamination-resistant coated substrate according to claim 1 or 2, wherein at least one kind selected from flame treatment, plasma treatment, and corona discharge treatment is performed as the heat treatment. Method. As the heat treatment, 5~250kJ ^/ m 2 / min of the manufacturing method of stain resistant coated substrate according to any one of claims 1 to 3, characterized in that the frame processing.   5. The method for producing a contamination-resistant coated substrate according to claim 1, wherein any one of a metal material, a plastic material, wood, mortar, and stone material is used as the substrate.

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