JPS6253228B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a painted decorative board, and more particularly to a method for manufacturing a painted decorative board by finishing a material with an uneven pattern or a surface to be coated by painting. Painted decorative boards are widely used as materials for the interior and exterior of buildings, such as plywood, hard boards, slate boards, calcium silicate boards, magnesium carbonate boards, gypsum boards, wood chip cement boards, iron boards, aluminum boards, etc. It is also used in vehicles, furniture, musical instruments, home appliances, kitchen equipment, ship interior materials, etc. Particularly recently, painted decorative boards with various improvements in appearance have been developed, and in particular, many materials with embossed patterns on the surface have been developed. Materials with such uneven embossed patterns include those made of the same material for the base material and the pattern part, as well as those made of cement, gypsum, etc.
Paints with raised patterns using a coating material made of another material such as synthetic resin, or multi-layer pattern paints (JIS6910-
(see 1975) is painted and dried. These materials with embossed concave and convex patterns do not themselves have the function of building materials, and are usually finished with a paint finish to protect the material and improve its appearance. Conventionally, when painting such uneven embossed pattern boards (for example, see the decorative board samples on the left side of reference photo (1) and the bottom left side of reference photo (3)), enamel finishes and colored clear finishes were used for aesthetic reasons. It is being done. Enamel finishing gives a three-dimensional appearance due to the uneven embossed pattern of the material, but for example, in the case of materials with a depth of about 5 mm or less of unevenness found in recent construction materials, when used on the exterior walls of houses etc. When viewed from a short distance, the uneven embossed pattern becomes unclear and cannot be said to be a finishing method that effectively takes advantage of the uneven embossed pattern of the material (for example, reference photo (1) right side and reference photo (3) lower right side makeup) (See plate sample). A low-viscosity colored clear coating method is known as a finishing method that more effectively expresses the uneven embossed pattern of the material. In this method, a semi-transparent colored clear paint is applied at a low viscosity to a board with an uneven embossed pattern that has been completely coated with enamel paint and dried, and the clear paint flows into the recesses, causing the enamel color to emboss around the raised patterns. The aim is to achieve some degree of effectiveness. However, the finished surface of the uneven embossed pattern board obtained by this low-viscosity colored clear coating method, that is, the method of applying and drying the low-viscosity colored clear paint on the uneven embossed pattern board that has been coated and dried with enamel paint, is The embossed base color appears on the periphery of the pattern, as if it were a border.
When viewed from a distance, the uneven embossed pattern becomes unclear and does not effectively express the convex parts of the material (for example, the makeup painted using the conventional method in reference photos (2) on the left and (3) on the upper left) (See plate sample). In order to solve these problems with the conventional technology, there are methods such as painting only the convex parts separately using a natural roller coater, etc., or removing the paint only on the convex parts using a reverse roll coater etc. to reveal the base color. However, when partially painting different hues of paint, there is a step in the hue at the boundary, making it impossible to express a natural hue change from the concave part to the convex part. Chisel roll coater work is an advanced coating technology that requires careful control of the thickness accuracy of the board, the depth accuracy of the uneven embossed pattern, and warpage of the board, and is not a preferred method for general mass production painting. Therefore, the purpose of the present invention is to solve the above-mentioned problems of the conventional coated decorative board with an uneven embossed pattern board,
There is a hue difference between the convex and concave parts of the decorative board to the extent that the convex pattern is clearly visible even when viewed from a distance, and there is no difference in color density from dark to light in the convex and concave areas of the pattern. Therefore, it is an object of the present invention to provide a method for manufacturing a painted decorative board having a smooth appearance. The method for producing a painted decorative board according to the present invention includes applying an undercoat to a material having an uneven pattern or a surface to be coated, if necessary, and then holding the material or surface to be coated substantially horizontally. The method is characterized in that an enamel paint is first applied, and then a colored clear paint is applied to the enamel paint film in an undried state, and then dried. Here, "a state in which the coating film is not dry" means a state in which the coating film is wet or a state in which there is residual liquid in the coating film, and does not include a state in which the coating film is "dry to the touch." Painted decorative boards according to the invention can be manufactured from textured embossed boards of any material that is subjected to a factory painted finish, such as, for example, slate boards, hardboards, steel boards, aluminum boards. , calcium silicate board, magnesium carbonate board, pulp cement board, gypsum board, asbestos cement board, etc., embossed pattern board materials, plywood,
Wood chip boards, slate boards, hard boards, calcium silicate boards, magnesium carbonate boards, pulp cement boards, iron plates, aluminum boards, gypsum boards, cement boards, etc., and cement-based or gypsum-based coating materials or multi-layers. Examples include painted and dried coating materials such as patterned paints. As necessary, on the materials and painted surfaces with these uneven patterns, we can strengthen the adhesion of the intermediate coat or top coat, suppress the fuzz of the material, prevent the suction of the intermediate coat or top coat, prevent rust, make the material waterproof, etc. An undercoat can be applied to strengthen the surface. Such an undercoat can be applied using any undercoat paint used for ordinary material coating, and no matter what undercoat paint is used, it will not affect the finish of the uneven embossed pattern board of the present invention. In addition, any intermediate coating used for ordinary coating of materials can be applied if necessary to hide the color and material of the material, stop the suction of the top coat, reinforce performance, improve appearance, etc. The painted finish of the uneven embossed pattern board is not affected in any way. In the painted decorative board according to the present invention, the top coat film is composed of an enamel paint and a colored clear paint on which the enamel paint film is applied in an undried state. Enamel paints are colored opaque liquid paints containing pigments, such as solvent-based paints,
It refers to water-soluble paints, emulsion paints, etc. Colored clear paints are clear paints (i.e., paints that do not contain pigments) mixed with pigments and dyes to color them, but the amount of pigments and dyes is the same as that of the above enamel paints. It refers to a coating film that is transparent or semi-transparent. As the film-forming elements (referred to as feedstock components) of the enamel paint used in the present invention, most of natural resins and synthetic resins can be used alone or in any combination. Typical examples include alkyd resins, phenolic resins, amino resins, polyurethane resins, acrylic resins, polyester resins, vinyl resins, epoxy resins, rubber resins, cellulose resins, aminoalkyd resins, acrylic urethane resins, etc. It is. Particularly preferred resins are:
Acrylic resin or acrylic urethane resin. As the pigment for the enamel paint used in the present invention, any inorganic and organic pigments commonly used in the formulation of paints can be used alone or in any combination. Examples of such inorganic pigments include white pigments such as titanium dioxide, black pigments such as carbon black, yellow pigments such as yellow lead, cadmium yellow, and ocher, red pigments such as vermilion, cadmium red, and red pigment, navy blue, and ultramarine. , blue pigments such as cobalt blue, and green pigments such as chromium oxide green.On the other hand, organic pigments include azo pigments such as Hansa Yellow, Toluidine Red, and Lysol Red, and phthalocyanine blue and phthalocyanine green. Examples include phthalocyanine pigments, quinacridone pigments such as shinkasharetsu, other vat dye pigments, dioxazine pigments, and isoindolinone pigments. In addition to the above coloring pigments, chalk, precipitated calcium carbonate, chalk,
Extender pigments such as barite powder, precipitated barium sulfate, clay, barite powder, talc, silica powder, diatomaceous earth, alumina, and gypsum can be used in combination. Furthermore, other pigments commonly used in paints, such as aluminum powder (silver powder), bronze powder (gold powder), and pearl pigments, can also be used alone or in combination. Preferably, the pigment content in the enamel paint is between 5 and 50% by weight. In addition to the film-forming elements and pigments mentioned above, the enamel paint used in the present invention includes a solvent, a dispersion medium, an anti-settling agent, a surfactant, an emulsifier, a leveling agent, an anti-color separation agent, a drying accelerator, a curing agent, Various additives such as a curing accelerator can be blended. It may also be in the form of a two-component type paint that uses a curing agent in combination. The constituent components of the colored cleaner paint used in the present invention are exactly the same as those of the above-mentioned enamel paint, but in order to provide a colored transparent or translucent paint film, the pigment content in the paint should be as low as 0.0001 to 10% by weight. preferable. If the amount of pigment added exceeds 10% by weight, the opacity of the coating film increases and the hue of the convex enamel layer becomes uneven, resulting in an enamel finish, which is not preferable. It is desirable that the color difference between the enamel paint and the colored clear paint is large, and the hue difference Δ between the enamel paint and the layered layer of enamel and colored clear paint is
E (=√ ² + ² + ² ) is preferably 2 or more. If this ΔE is less than 2, the difference in hue between the concave and convex portions of the painted decorative board will not be noticeable, and the intended unevenness will not be felt sufficiently. Although it is generally preferable that the film-forming elements of the enamel paint and the colored clear paint are each made of the same resin, it is not essential to use the same resin, and different resins can be used in an appropriate combination. In finishing the painted decorative board according to the present invention, as described above, the material or the surface to be coated is held in a substantially horizontal state, and the enamel paint and the colored clear paint are successively applied in this order in the middle. It is essential to paint without a drying process (paint while the enamel paint film is still wet). When producing a painted decorative board in accordance with the present invention, after application of the enamel paint, the enamel paint film is applied while the film is wet (i.e. with residual liquid) and over this film. It is important that the colored enamel paint is applied with substantially no mixing of the colored clear paint. Mixing of the enamel coating and the colored clear paint can be easily avoided by appropriately adjusting the coating interval and the viscosity of both paints. Techniques for wet-on-wet coating of enamel and colored clear paint while holding the textured material or the surface to be coated in a horizontal state include painting with a so-called curtain flow coater, painting with a spray, and painting with a roll coater. Although various coating techniques can be used, coating with a curtain flow coater is most suitable, as it provides a uniformly finished coat at high operating speeds on horizontally uneven surfaces. Coating with a curtain flow coater is performed under general curtain flow coater coating conditions, such as paint viscosity of approximately 30 to 120 seconds (#4 Ford Cup,
20°C) and a coating amount of about 50 to 300 g/m ² . However, conditions such as (i) no unpainted areas in the concave parts of the material, (ii) no breakage of the curtain or generation of bubbles in the tank or curtain, and (iii) conditions such as coating viscosity, coating amount, and conveyor speed during continuous coating work. Needless to say, it is necessary to pay attention to constant management. Preferred paint viscosity is #4 food cup (20 DEG C.), 30 to 120 seconds for enamel paints and 8 to 30 seconds (more preferably 10 to 20 seconds) for colored clear paints. When a colored clear paint is applied wet-on-wet on an enamel coating according to the present invention, the colored clear paint flows down from the convex portions to the concave portions on the material after painting, which improves the embossment of the enamel color on the convex portions and improves the embossment. (For example, see reference photos (2) on the right side and (3) on the upper right side of the decorative board samples painted using the method of the present invention). This tendency becomes extremely noticeable when the viscosity of the colored clear paint (#4 food cup, 20 DEG C.) is within the above range of 8 to 30 seconds. If the consistency is less than 8 seconds, curtain breakage is likely to occur. As mentioned above, enamel painting and colored clear painting must be performed continuously with the enamel paint film undried, but the time between applications depends on the type of paint used, the resin type, solvent-based,
Although it varies considerably depending on coating conditions, environmental conditions, etc., it is generally about 0.1 seconds to 1 minute. In any case, as mentioned above, it is important that the enamel coating be applied in an undried state and that the enamel coating and the colored clear coating do not mix together when the colored clear coating is applied. After the colored clear coating, the coating film can be dried by any conventional method such as natural drying or forced hot air drying. Examples of the present invention will be described below. Example Applying a synthetic resin emulsion-based multi-layer pattern spraying agent specified in JIS A-6910-1975 to a 6 mm thick flexible board specified in JIS A-5403-1974 in the coating process shown in Tables 1 and 2 below. The uneven embossed pattern boards () and () were created by painting.

【table】

【table】

[Table] On the other hand, top coat enamel paints A and B and top coat colored clear paints A and B are applied wet-on-wet on these uneven embossed pattern boards.
were prepared according to the formulations shown in Tables 3 and 4 below.

【table】

【table】

[Table] The top coat thus prepared was applied wet-on-wet to the above-mentioned uneven embossed pattern plates () and () under the conditions shown in Table-5.
The results are also shown in Table-5.

【table】

【table】

Claims (1)

[Scope of Claims] 1. After applying an undercoat if necessary to the material or the surface to be coated which has an uneven pattern, first apply enamel paint while holding the material or the surface to be coated substantially horizontally. A method for producing a painted decorative board, which comprises: applying a colored clear paint to the enamel paint film in an undried state, and then drying the coated film. 2. The enamel paint has a colored pigment content of 5-50% by weight and a consistency of 30-120 seconds (#4 food cup,
20°C), and the colored clear paint has a colored pigment content of 0.0001 to 10% by weight and a consistency of 8 to 30 seconds (#4
20°C). 3 Claims using a combination of paints with a coating amount of 50 to 300 g/m ² and a hue difference ΔE of 2 or more between the enamel paint film and the overcoated enamel and colored clear paint film The manufacturing method according to item 1 or 2.