JP2005171734A - Exterior wall panel and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a building outer wall panel with reduced gloss and a method for manufacturing the same.
SOLUTION: The building exterior wall panel 5 is overcoated with a water-based paint, and the resin solid content (coating solid content) when applied to the panel surface is from 37% by weight to 80% by weight. And the 60 ° specular gloss at the flat part of the painted panel surface 51 is in the range of 1 to 6 by coating at a coating application amount of 15 g / m ² or less. It is in.
[Selection] Figure 1

Description

  The present invention relates to a building exterior wall panel with reduced gloss and a method for manufacturing the same.

  The exterior wall panel for construction is painted on the surface for the purpose of protecting the substrate of the exterior wall panel. At that time, the coating film usually gives a gloss and a decorative effect. However, in recent years, the values on the outer walls of houses have been diversified, and the ones that are less glossy, calm, and profound are becoming popular.

In order to produce a coating film with no gloss (loss) or low gloss, generally, a method is used in which the pigment volume concentration (PVC) is increased to form extremely minute irregularities on the coating film. In particular, fine powder of calcium carbonate and china clay called titanium oxide and extender pigments are effectively used as a delustering agent. These paints usually contain 20% by weight or more of the extender pigment.
Here, the pigment volume concentration (PVC) is a ratio of the pigment content in the mixed solid content of the resin and the pigment, and is obtained from the following formula.

In addition, as shown in the following published patent publications, there are some which have a natural stone-like coating to improve the design. For example, an outer wall panel for painting that expresses the appearance of a stone surface such as natural stone (Patent Document 1), or an outer wall panel for painting that has improved wear resistance with a design with a natural stone feeling (Patent Document 2), or An outer wall panel for painting having a glittering granite-like pattern with a glittering feeling (Patent Document 3) is known. Or although it is a matt paint, the water-based matt paint (patent document 4) which does not produce crack or peeling even if it uses outdoors is known.
JP 7-89006 A JP-A-7-166110 JP-A-8-151541 Japanese Patent Laid-Open No. 11-21514

  However, the paints described in Patent Documents 1 to 3 are not intended for matting. In addition, although the paint for the purpose of matting described in Patent Document 4 has a degree of difference, an extender pigment having a small particle diameter of 20% by weight or more is blended. There was a problem that the resin component was decomposed and a pigment was precipitated from the surface of the coating film (choking), which deteriorated the design.

  An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an outer wall panel for a building that can maintain a matte coating surface for a long period of time without causing choking, and a method for manufacturing the same.

  The present invention has been made in view of the above situation, and 60 ° specular gloss at the flat part of the panel surface painted on the surface of the building outer wall panel even when using a normal water-based paint having a high PVC in the paint. The present inventors have found a coating outer wall panel having a value in the range of 1 to 6 and a method of uniformly coating, and have reached the present invention.

In other words, the present invention according to claim 1 is an exterior wall panel for building that is overcoated with a water-based paint, and has a resin solid content (coating solid content) of 37 when applied to the panel surface. When coated at a coating weight of 15 g / m ² or less, the 60 ° specular glossiness at the flat part of the coated panel surface is less than 80% by weight and less than 80% by weight. It is the outer wall panel for construction characterized by being in the range of 1-6.

  The invention according to claim 2 is the building exterior wall panel according to claim 1, wherein the substrate of the building exterior wall panel is made of a hard wood chip cement board.

The present invention according to claim 3 is an exterior wall panel for construction that is overcoated with a water-based paint, and the resin solid content of the paint when applied to the panel surface is not less than 37% by weight and less than 80% by weight. Yes, and by applying at a coating application amount of 15 g / m ² or less, the 60 ° specular gloss at the flat part of the coated panel surface is in the range of 1-6. It is the manufacturing method of the outer wall panel for construction characterized by adjusting to.

  In the present invention, the above specular gloss is defined as JIS-Z-8741 that allows a light beam having a specified opening angle to be incident on the measurement sample surface and reflected in the specular reflection direction. Is a value measured using a so-called gloss meter. There are various types of glossmeters, such as those that simply measure specular reflection, those that measure the ratio of specular reflection and scattered reflection, or those that measure the sharpness of an image, but here the specular reflection glossiness manufactured by Minolta The value corresponding to the value measured using a meter is shown.

  In the present invention, the measurement part of the target panel when measuring the gloss needs to be a flat part, and the degree of unevenness is a part where the difference between the highest part and the lowest part of the panel substrate is 0.5 mm or less. did. However, this description does not mean that the present invention is limited to the flat outer wall panel.

In the present invention, the weight solid content of the coating resin when applied to the exterior panel surface (hereinafter sometimes referred to as “coating solid content”) is the resin in the coating immediately after the coating is applied to the object. It represents the ratio of solid components such as pigments and can be calculated by the following formula.

Hereinafter, the building exterior wall panel and the manufacturing method thereof according to the present invention will be described in detail.
The board | substrate of the outer wall panel which is a to-be-coated article of this invention is a building material, and has an uneven | corrugated | grooved part. Specifically, plate-like objects used for outer parts such as outer walls, inner walls, and roofs of general buildings, buildings, offices and the like can be mentioned. The size is preferably about 1,000 mm × about 3,000 mm. In addition, these surfaces have round, acute, and acute irregularities and large concave portions having narrow or wide grooves. These uneven shapes can be formed by a known method. Examples of materials for these building materials include ALC materials, slate, wood chip cement boards, and the like. In addition, when these building materials are pre-heated and coated in a state where the temperature is kept at 40 to 80 ° C., there is an effect that the coating sagging at the convex portions is reduced and the moisture content in the coating film becomes constant. It is preferable.

The water-based paint applied to these building materials is a liquid paint using water as a solvent or a dispersion medium, and a water-based or water-dispersible paint containing a vehicle resin such as an acrylic resin, a polyester resin, a urethane resin, or a fluororesin is suitable. These may be opaque paints colored in a desired color tone, or may be transparent paints to which no pigment is added. In coating, these water-based paints are preferably adjusted to have a viscosity of 20 to 80 seconds / Iwata Cup (HIS) / 20 ° C.

  An airless coating machine or an air coating machine is preferably used as a coating machine for applying these paints. The airless coating machine pressurizes a paint with a pump, connects it to an airless gun with a water-resistant hose, sprays the paint with liquid pressure, and paints it on a surface to be coated. In the air coating machine, the paint pushed out by the pump from the tip of the coating gun is sprayed and atomized by the atomizing air and pattern air around the tip of the coating gun to coat the surface to be coated. There are air-driven, hydraulic-driven, and electric pumps. The former two are driven by compressed air or hydraulic pressure with a plunger-type pump, and the hydraulic pressure is increased several to several tens of times with respect to the driving pressure. A pump is used. In the electric type, one that directly moves a pump via hydraulic pressure by a motor can be used.

  The spray pressure of the paint at the time of painting with an airless coater is preferably 0.5 to 2 MPa, particularly preferably 0.8 to 1.2 MPa, and the spraying pressure of the paint at the time of painting with the air coater is 0.15 to 0.3 MPa, particularly The distance from the gun tip to the coating surface is preferably 50 to 300 mm, particularly preferably 100 to 250 mm, and the spray pattern width is preferably 200 to 600 mm, particularly preferably 250 to 400 mm.

In the present invention, such a coating machine is used, and a water-based paint is repeatedly applied to an object to be coated. At that time, the application amount of the overcoat per one application must be 15 g / m ² or less. That is, the total coating amount is, for example, 60 g / m ² or less in the case of four coatings and 120 g / m ² or less in the eight coatings. A coating outer wall panel with low gloss can be obtained by adjusting the coating solid content to a range of 37 wt% or more and less than 80 wt% while maintaining this coating amount. And, as a painting method for recoating, a reciprocating coating method in which a spray gun is reciprocated across the traveling direction of the object to be coated to apply the paint on the object to be painted may be used. Alternatively, it may be a hand-wiping method in which the object to be coated is fixed and the airless coating machine is reciprocated in a certain direction with respect to the object to be coated.

The coating amount of these sprayer, the coating solution ^20g / ^{m 2 ~120g} / m 2 based on, is preferable in particular from ^{30g / m 2 ~100g / m 2} . The amount of coating and the number of times of coating per coating are 5 to 15 g / m ² and ² to 8 times, particularly 8 to 15 g / m ² and it is preferable to perform four times of coating.
In order to adjust the coating solid content within the range of 37% by weight or more and less than 80% by weight necessary for forming a coating film with low gloss, the paint may be set within this range before coating. A method may be used in which the plate temperature is raised to release the moisture in the paint, or the atomization air of the air coating is raised to increase the atomization of the paint to thereby release the moisture in the paint.

It is necessary to adjust the specular gloss at the flat portion of the panel surface having a low gloss coating film formed by the present invention in the range of 1-6. This is because if it is less than 1, the lightness is lacking and a heavy impression is given, and if it exceeds 6, it is too bright and the sense of quality is impaired.
With the above method, it is possible to form a coating film with low gloss even with a normal paint that does not raise PVC.

The building exterior wall panel according to claim 1 is a building exterior wall panel coated with a water-based paint, and has a resin solid content (coating solid content) of 37 when applied to the panel surface. less than wt% to 80 wt%, and, fill per the overlapped coating amount of 15 g / ^{m 2}
By painting below, the 60 ° specular gloss at the flat part of the painted panel surface is in the range of 1-6, so that it becomes a predetermined matte surface, Does not cause choking and maintains its state.

  In the building exterior wall panel according to claim 2, since the board of the building exterior wall panel is made of a hard wood cement board, the board surface has moderate unevenness and moderate moisture absorption and desorption over a long period of time and is durable. The matte surface of the panel becomes heavy and has a natural texture, and the state is maintained for a long time.

The method of manufacturing an exterior wall panel for building according to claim 3 is an exterior wall panel for building that is overcoated with a water-based paint, and the weight solid content of the resin of the paint when applied to the panel surface is 37% by weight. When it is less than 80% by weight and the coating amount per coating is 15 g / m ² or less, the 60 ° specular gloss at the flat part of the coated panel surface is 1 to Since the surface is adjusted to be in the range of 6, the surface becomes a predetermined matte surface, and does not cause choking even after a long period of time, and the state is maintained.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view for explaining a method for manufacturing an architectural outer wall panel according to an embodiment of the present invention.

1. Preparation of sample 1) Object to be coated A wood cement board (size: 890 mm × 1500 mm × 5 mm) having a groove (large recess) having a width of 10 mm and a depth of 3 mm, and kept warm (preheated) at 40 to 60 ° C.
2) Aqueous paint Acrylic resin reddish brown or transparent emulsion paint. The weight solid content of the resin in the paint is 30 to 37% by weight and PVC is 35% or less. The paint viscosity was adjusted with a thickener or the like so that the viscosity of the coating was 30 to 60 seconds / Iwata Cup (HIS) / 20 ° C.
3) Coating method FIG. 1 is a schematic diagram showing a configuration example of equipment used for creating each example and comparative example. As shown in FIG. 1, in the reciprocating coating machine 1, a connecting member 3 in which two coating guns 2 are fixed in a vertical direction with respect to an object (outer wall panel for building) 5 reciprocates. Since each coating gun 2 is fixed to the connecting member 3, the two coating guns 2 are also applied by reciprocating in the vertical direction with respect to the article 5 that has traveled on the conveyor 10. When the coating machine 1 uses an airless coating machine, the spraying pressure of the paint at the time of painting is 0.8 to 1.2 MPa, and the spraying air pressure at the time of painting in the case of air painting is 0.2 to 0.25 MPa. did. The operating conditions of the reciprocating coating machine 1 are: the distance from the gun tip 21 to the coated surface 51 is 300 mm, the spray pattern width in the longitudinal direction (traveling direction) is 250 mm, the reciprocating speed is 48 m / min, and the conveyor speed is 6 m / min. The coating was carried out with a minimum effective reciprocating length of 2000 mm.

Examples of the present invention will be described below.
(Example 1)
A coating of 12 g / m ² (4 g / m ^{2) is} applied to a colored acrylic emulsion paint having a resin solid content of 37% by weight and a paint viscosity of 30% PVC in the paint and adjusted to a viscosity of 60 seconds (NK2 / 20 ° C.). The coating outer wall panel having a pre-painting plate temperature of 40 ° C. was coated airless so that the coating temperature was 48 g / m ² ), and dried at 80 ° C. for 20 minutes to prepare a coating sample A. The coating solid content at this time was 38%.

(Example 2)
A transparent acrylic emulsion-based paint whose coating viscosity was adjusted to 60 seconds (NK2 / 20 ° C.) with a solid content of 37% by weight of resin in the paint and 0% PVC in the paint was applied at a coating amount of 12 g / m ² (4 The coating outer wall panel having a pre-painting plate temperature of 40 ° C. was coated with airless so that the coating temperature was 48 g / m ² ), and dried at a temperature of 80 ° C. for 20 minutes to prepare a coating sample B. The coating solid content at this time was 38%.

(Example 3)
A coating of 12 g / m ² (4 g / m ^{2) is} applied to a colored acrylic emulsion paint having a resin solid content of 37% by weight and a paint viscosity of 30% (NK2 / 20 ° C.) adjusted to 30% (NK2 / 20 ° C.). A coating sample C was prepared by applying airless coating to a building outer wall panel having a pre-painting plate temperature of 40 ° C. so as to be 48 g / m ² ) by recoating and drying at a temperature of 80 ° C. for 20 minutes. The coating solid content at this time was 40%.

Example 4
A coating of 12 g / m ² (4 g / m ^{2) is} applied to a colored acrylic emulsion paint having a resin solid content of 37% by weight and a PVC viscosity of 30% in the paint adjusted to a viscosity of 30 seconds (NK2 / 20 ° C.). The coating outer wall panel having a pre-painting plate temperature of 60 ° C. was airless-coated so that the coating temperature was 48 g / m ² ), and dried at 80 ° C. for 20 minutes to prepare a coating sample D. The coating solid content at this time was 44%.

(Comparative Example 1)
A coating of 12 g / m ² (4 g / m ^{2) is} applied to a colored acrylic emulsion paint whose viscosity is adjusted to 60 seconds (NK2 / 20 ° C.) with a solid content of resin in the paint of 30% by weight and PVC in the paint of 30%. The coating outer wall panel having a pre-painting plate temperature of 60 ° C. was airless-coated so that the coating temperature was 48 g / m ² ), and dried at a temperature of 80 ° C. for 20 minutes to prepare a coating sample E. The coating solid content at this time was 32%.

(Comparative Example 2)
A colored acrylic emulsion paint whose coating viscosity is adjusted to 60 seconds (NK2 / 20 ° C.) with a solid content of 37% by weight of resin in the paint and 30% PVC in the paint is applied at a coating amount of 24 g / m ² (2 The coating outer wall panel having a pre-painting plate temperature of 40 ° C. was coated with airless so that the coating temperature was 48 g / m ² ), and dried at 80 ° C. for 20 minutes to prepare a coating sample F. The coating solid content at this time was 38%.

(Comparative Example 3)
A colored acrylic emulsion paint whose coating viscosity is adjusted to 60 seconds (NK2 / 20 ° C.) with a solid content of 37% by weight of resin in the paint and PVC of 60% in the paint is applied at a coating amount of 24 g / m ² (2 A coating sample G was prepared by applying airless coating to a building exterior wall panel having a pre-painting plate temperature of 40 ° C. so that the coating temperature was 48 g / m ² ), and drying at a temperature of 80 ° C. for 20 minutes. The coating solid content at this time was 38%.

  Table 1 shows the results of measuring the glossiness of the coating samples A, B, C, D, E, F, and G.

  From Table 1, it was necessary to increase the pigment concentration (PVC) in the paint to create a matte outer wall panel as shown in the comparative example in the past. It was found that even ordinary paints with good weather resistance that do not raise PVC have a low glossiness that gives a feeling of weight. Moreover, even if the building exterior wall panel of the embodiment of the present invention is exposed to outdoor solar radiation or wind and rain for a long time, the matte state is maintained without causing choking, and the gloss that gives a profound feeling can be maintained. .

  As mentioned above, although the Example of this invention was described, this invention is not limited to the said Example, Even if there is a design change etc. of the range which does not deviate from the summary of this invention, it is included in this invention. For example, an architectural outer wall panel may be changed to an ALC panel.

It is a schematic diagram explaining the manufacturing method of the outer wall panel for buildings which is an Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reciprocating type coating machine 2 Painting gun 3 Connecting member 4 Drive part 5 Building outer wall panel 10 Conveyor 20 Target distance

Claims (3)

A building exterior wall panel that is overcoated with a water-based paint, the solid content of the resin of the paint when applied to the panel surface (coating solid content) is 37% by weight or more and less than 80% by weight, and The 60 ° specular gloss at the flat part of the coated panel surface is in the range of 1 to 6 by coating at a coating application amount of 15 g / m ² or less per time. Building exterior wall panels. 2. The building outer wall panel according to claim 1, wherein the board of the building outer wall panel is made of a hard wood cement board. A building exterior wall panel that is overcoated with a water-based paint, the solid content of the resin of the paint when applied to the panel surface (coating solid content) is 37% by weight or more and less than 80% by weight, and By coating with a coating application amount of 15 g / m ² or less per time, the 60 ° specular gloss at the flat part of the coated panel surface is adjusted to be in the range of 1-6. The manufacturing method of the outer wall panel for buildings characterized by the above-mentioned.

Images