JPH0975843A - Building board and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To present deterioration of external appearance by preventing sand from dropping out of a substrate and to improve the durability of the substrate. SOLUTION: An undercoating film 2 is formed on the surface of a substrate 1. Sand 3 are stuck to the surface of the undercoating film 2 to form a sand layer. An intermediate coating film 4 to coat the surface of the sand 3 is formed on the whole surface of the undercoating film 2. An overcoating film 5 is partially formed on the surface of the intermediate coating film 4. Even in the part where the overcoating film 5 is not formed, the sand 3 is sandwiched between the undercoating film 2 and the intermediate coating film 4 and the sand 3 is held by high adhesion strength of both the undercoating film 2 and the intermediate coating film 4. Moreover, the whole body of the substrate 1 can be coated with a thick film composed of both the undercoating film 2 and the intermediate coating film 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building board used as an exterior material such as an outer wall material or a slate flat roof tile, and a method for manufacturing the building board.

[0002]

2. Description of the Related Art Conventionally, there has been provided a building board which is made by adhering sand to the surface of a substrate, and FIG. 4 shows an example of this kind of building board. In this building board, projections 10 and depressions 11 are repeatedly provided continuously on the surface of an inorganic board such as a cement board to form a corrugated substrate 1, and the surface of the substrate 1 is sprayed with an undercoat paint. Then, sand 3 is sprinkled and adhered to the surface of the undercoat paint, and then the substrate 1 is heated to cure the undercoat paint to form the undercoat paint film 2. Next, the undercoat paint film 2 is formed in the convex portion 10. The top coating material is applied to the surface of the roll by a roll, and the sand 3
And then the substrate 1 is heated to cure the top coating material to form the top coating film 5.

[0003] Such a building board has a natural feeling even if the substrate 1 is made of an artificial material such as a cement board by providing the surface with the sand 3 attached thereto, and the matte by the sand 3 is used. The effect is such that a high-class feeling can be produced. Further, by forming the upper coating film 5 only on the convex portion 10, the lower coating film 2 can be formed.
The upper coating film 5 is provided with a step so that a deep engraving feeling can be produced.

[0004]

However, in the above-mentioned conventional example,
Since the sand 3 is held on the substrate 1 by being attached to the undercoat coating film 2, most of the surface of the sand 3 is exposed, and the sand 3 cannot be held on the substrate 1 with a high fixing force. The problem that the sand 3 is peeled off from the substrate 1 to impair the appearance by rubbing the sand 3 with the roll for applying the overcoat paint and by exposing the sand 3 not covered with the overcoat paint film 5 to wind and rain. was there. Further, in the above-mentioned conventional example, since the concave portion 11 of the substrate 1 is covered only by the undercoat coating film 2, the substrate 1 cannot be sufficiently protected from wind and rain,
There was a problem of low durability. Furthermore, in the above-mentioned conventional example, since the top coat paint is applied using a roll, the roll and the sand 3 are rubbed, and the roll is damaged or worn, so that the roll must be frequently replaced. However, there is a problem that the burden of maintenance becomes large.

The present invention has been made in view of the above points, and it is possible to prevent the sand from peeling off from the substrate so as not to impair the appearance and to improve the durability. It is an object of the present invention to provide a board, and an object of the present invention is to provide a method of manufacturing a building board that can reduce the burden of maintenance.

[0006]

A building board according to claim 1 of the present invention is provided with an undercoat coating film 2 formed on a surface of a substrate 1 and sand 3 attached to the surface of the undercoat coating film 2. An intermediate coating film 4 covering the surface of the sand 3 is formed over the entire surface of the undercoat paint 2, and an upper coating film 5 is partially formed on the surface of the intermediate coating film 4. It is a thing.

In the method for manufacturing a building board according to claim 2 of the present invention, the temperature of the substrate 1 is set to 70 to 95 ° C., and an undercoat paint having a viscosity of 30 ± 8 seconds with an Iwata cup NK-2 is used. It is applied to the surface of the substrate 1, then the sand 3 is sprinkled and adhered to the surface of the undercoat paint, and then the intermediate paint is applied over the entire surface of the undercoat paint to the surface of the sand 3 with the intermediate paint. And then partially coating the top coating film with a roll on the surface of the intermediate coating composition.

[0008]

Embodiments of the present invention will be described below. As the substrate 1, any inorganic plate conventionally used as a building material such as a cement board or a gypsum board can be used. The surface of the substrate 1 is formed in a wavy shape such that the convex portions 10 and the concave portions 11 are continuously repeated, and a sealer layer 12 is formed on the entire surface of the substrate 1 in order to improve adhesion with the undercoat coating film 2. It is formed over. As the sand 3, for example, JIS No. 6/7 silica sand such as color sand 6.7 white (trade name) can be used. In addition, it is preferable to use white sand 3, and if sand 3 of a color other than white is used, the color of the sand 3 itself may stand out, and the design may become vulgar and the design may be impaired.

The undercoat paint and the intermediate paint can be formed by the same paint, and for example, a colorless or colored paint of acrylic resin emulsion can be used. Further, as the undercoat paint and the intermediate paint, those having a viscosity of 30 ± 8 seconds can be used in the viscosity measurement using the Iwata cup NK-2 which is a viscosity cup. Iwata cup NK-2 has a viscosity of 22
If it is less than a second, the undercoat paint or the midcoat paint may drip when applied to the substrate 1 and the undercoat coating film 2 or the intermediate coating film 4 may not be formed, or the undercoat coating film 2 may be formed.
Also, the thickness of the intermediate coating film 4 cannot be made sufficiently large, and coating film defects such as cracks may occur. If the viscosity of the Iwata Cup NK-2 exceeds 38 seconds, the viscosity of the undercoating material or the intermediate coating material becomes too high, which may cause the nozzle of the spray to be clogged, and at the same time, the undercoating material applied to the substrate 1 becomes too hard. Therefore, the sand 3 cannot be adhered to the undercoating material with a high fixing force. Therefore, in the subsequent step of spraying the undercoating material onto the surface of the undercoating material, the sand 3 is removed from the undercoating material by the momentum of the intermediate coating material. It may peel off and be blown away.

The Iwata Cup NK-2 is JIS K
5400 is a simplified version of the Ford Cup specified in 2.1.1. Iwata cup NK- shown in FIG.
The second cup body 30 is formed in substantially the same manner as the cup body of the Ford cup, and has an inner volume of 46.7 cc and an orifice 33 diameter (diameter) of 3.65 mm. A handle 31 is attached to the upper end of the cup body 30 with a screw 32. Then, the Iwata cup NK-2 scoops the paint with the cup body 30 while holding the handle 31, and the olephis 3
The viscosity can be measured by the time required for all the paint scooped up from 3 to the cup body 30 to flow out.

As the top coat, an acrylic resin emulsion colored in a color such as urban gray (gray) or urban beige (skin color) can be used. The viscosity of the top coat can be changed by the color. For the urban gray top coat, the viscosity measurement with the Iwata cup NK-2 is 45 ± 5 seconds. For the urban beige top coat, the viscosity is with the Iwata cup NK-2. 23 ± 5 seconds, and the topcoat paints of other colors can be set to 38 ± 5 seconds by viscosity measurement using Iwata Cup NK-2. If the viscosity of the top coat is lower than the above set values,
Since the top coating material is less likely to be transferred to the roll, the absolute coating amount (required coating amount) on the substrate 1 cannot be secured,
If the viscosity of the topcoat paint is higher than each of the above set values, the transfer amount of the topcoat paint to the roll becomes too large, and there is a possibility that multicolor coating such as partial two-color coating cannot be performed on the substrate 1. .

Next, a method for manufacturing a building board according to the present invention will be described. As shown in FIG. 2, first, the substrate 1 is dried by a dryer 13
Dry with. At this time, the heating temperature of the dryer 13 is set so that the substrate 1 is carried out of the dryer 13 at the exit plate temperature of 70 to 95 ° C. If the temperature of the outlet plate of the substrate 1 is lower than 70 ° C., when the undercoating paint is applied to the substrate 1, the curing speed of the undercoating paint may be slow, and paint dripping may occur to cause uneven coating. If unevenness occurs, the sand 3 cannot be attached to the portion where the amount of the undercoat paint applied is small, and the sprayed state of the sand 3 may become uneven. Further, if the temperature of the exit plate of the substrate 1 exceeds 95 ° C., the undercoat paint will cure before the undercoat paint adheres to the substrate 1,
Anchoring of undercoat paint to substrate 1 (anchor effect)
Adhesion of the undercoating film 2 to the substrate 1 may be insufficient due to lack thereof, and sand 3 may be sprinkled on the undercoating film 2 after drying and curing (dry-on state). There is a risk that the adhesion strength of the sand 3 due to 2 will be insufficient and the sand 3 cannot be sufficiently adhered to the undercoat coating film 2.

Next, an undercoat paint is applied to the surface of the sealer layer 12 of the substrate 1 by a spray 20. The coating amount of the primer coating can be set to 8.3 ± 1.0 g / scale ^2. If the coating amount is less than 7.3 g / scale ² , the thickness of the undercoating film 2 cannot be increased, and the quality and appearance of the coating film may be deteriorated, and the solidification of the sand 3 by the undercoating film 2 may occur. There is a risk that the adhesion will be reduced and the sand 3 will not be able to adhere sufficiently to the undercoat coating film 2. Moreover, the coating amount is 9.3 g /
Beyond rod ^2, there is a possibility that the coating film of the undercoating film 2 is too thick defects such as cracks in the undercoating film 2 occurs.

Next, the sand 3 is sprayed on the surface of the undercoat paint by the sand spreader 21 to adhere the sand 3 to the surface of the undercoat paint. The amount of sand 3 sprayed can be set to 6.0 ± 0.6 g / scale ² . If the amount of spraying is less than 5.4 g / square ² , the amount of the sand 3 attached to the undercoat paint may be small, and it may not be possible to exhibit characteristics such as formation of a unique design due to the attachment of the sand 3. If the amount of spraying exceeds 6.6 g / square ² , the amount of the sand 3 attached to the undercoat paint may be too large and the appearance may be deteriorated, and the amount of the undercoat paint per unit volume of the sand 3 is small. As a result, the adhesion of the sand 3 to the undercoat coating film 2 may be reduced.

Next, an intermediate paint is applied to the surface of the undercoat paint by a spray 23 so as to cover the surface of the sand 3. The coating amount of the intermediate coating is 8.3 ± 1.0 as in the case of the above-mentioned undercoating.
It can be set to g / scale ² . Coating amount is 7.3g /
If the length is less than ² , the thickness of the intermediate coating film 4 may be too thin and the quality and appearance of the intermediate coating film 4 may be deteriorated, and the sand 3 cannot be sufficiently covered with the intermediate coating material. The holding power of the sand 3 in the intermediate coating film 4 may decrease. On the other hand, if the coating amount exceeds 9.3 g / square ² , the thickness of the intermediate coating film 4 becomes too large, and defects such as cracks may occur in the intermediate coating film 4.

Next, the substrate 1 is placed in a drier 14 and the undercoat paint and the intermediate paint are dried and cured to form an undercoat film 2.
And the intermediate coating film 4 are respectively formed. At this time, the substrate 1 is 6
The heating temperature of the dryer 14 is set so that it is carried out from the dryer 14 at an outlet plate temperature of 0 to 85 ° C. If the outlet plate temperature of the substrate 1 is less than 60 ° C., the undercoating paint and the intermediate coating paint are insufficiently cured (insufficient film formation), and the performance of the undercoating film 2 and the intermediate coating film 4 such as holding the sand 3 is deteriorated. If the temperature of the exit plate of the substrate 1 exceeds 85 ° C., the temperature of the undercoat coating film 2 and the intermediate coating film 4 becomes too high, and the surface of the intermediate coating film 4 is coated. There is a possibility that an external appearance defect such as a mud crack may occur in the top coat film 5 formed of the top coat paint.

Next, in the convex portion 10 of the substrate 1, the top coat paints of a plurality of colors are applied to the surface of the intermediate coat film 4 by a roll 6 made of sponge. At this time, the roll 6 changes the pressing margin (the amount of depression of the roll 6 when the roll is brought into contact with the substrate 1) on the surface of the intermediate coating film 4 for each color of the top coating material. For example, the topcoat paint for Urban Gray has a control allowance of 3 to 5 mm, the topcoat paint for Urban Beige has a control allowance of 9 to 10 mm, and the topcoat paints of other colors have a control allowance of 4 to 5 mm. Apply. If the suppression amount for each color is smaller than the set value, one type of topcoat paint will be applied to the entire surface of the intermediate coating film 4, and multicolor coating such as two-color coating cannot be performed. If the suppression amount for each color is larger than the set value, the roll 6 cannot be sufficiently brought into contact with the surface of the intermediate coating film 4, and there is a possibility that the top coating material cannot be applied.

Next, the substrate 1 is placed in a drier 15 to dry and harden the top coating material to form a top coating film 5.
At this time, the substrate 1 is dried at the exit plate temperature of 65 to 85 ° C.
The heating temperature of the dryer 15 is set so that the dryer 15 can be carried out from. If the outlet plate temperature of the substrate 1 is lower than 65 ° C., the curing of the overcoat paint may be insufficient (insufficient film formation), which may cause deterioration of the film performance of the overcoat film 5 such as protection of the substrate 1. If the outlet plate temperature of the substrate 1 exceeds 85 ° C., the resin components of the undercoat coating film 2, the intermediate coating film 4, and the top coating film 5 may be destroyed.

In this way, the building board as shown in FIG. 1 can be formed. This building board has a natural feeling even if the substrate 1 is made of an artificial material such as a cement board by providing the sand 3 on the surface, and the matte effect of the sand 3 gives a high-class feeling. By providing the substrate 1 with the convex portion 10 and the concave portion 11 to give a deep engraving feeling, the top coat film 5 is applied only to the convex portion 10 to form an intermediate coating. It is possible to create a deep engraving feeling by providing a step between the coating film 4 and the top coating film 5.

Further, in the above-mentioned building board, since the sand 2 is adhered to the undercoat coating film 2 and the surface of the sand 3 is covered with the intermediate coating film 4, the sand 3 is coated with the undercoat coating film 2 and the intermediate coating film 4. It can be sandwiched between (sandwiched), sand 3 can be held with a high fixing force of both the undercoating coating film 2 and the intermediate coating film 4, and the influence of the friction of the roll or the weather when applying the topcoating paint. Thus, the sand 3 can be prevented from peeling off from the substrate 1. Also, the undercoating film 2 and the topcoating film 5
Since the intermediate coating film 4 is provided over the entire surface of the substrate 1 between the substrates, the substrate 1 can be covered with a thick film formed by both the undercoat coating film 2 and the intermediate coating film 4, 1 is less susceptible to the effects of wind and rain, and the durability of the substrate 1 can be improved. In particular, in the concave portion 11 of the substrate 1, the undercoat coating film 2
The intermediate coating film 4 can be covered with a thick film, and the durability of the substrate 1 in the recess 11 can be improved more than in the conventional example. Furthermore, the surface of the undercoat coating film 2 is coated with the intermediate coating film 4
It is possible to prevent the undercoat coating film 2 from being deteriorated by covering with, and it is possible to improve the performance of the undercoat coating film 2 such as protection of the substrate 1.

Further, since the surface of the sand 3 is covered with the intermediate coating film 4, when the top coating material is applied by the roll 6, the sand 3 does not come into direct contact with the sand 3, and the hardness is higher than that of the sand 3. Since the roll 6 is brought into contact with the intermediate coating film 4 having a low level, the abrasion degree of the roll 6 can be made smaller than the case where the roll 6 is brought into direct contact with the sand 3 as in the conventional example, and the roll 6 can be replaced. The frequency can be reduced.
Further, since the frequency of exchanging the rolls 6 is reduced in this way, productivity can be improved and the burden on maintenance can be reduced.

[0022]

As described above, according to the invention described in claim 1 of the present invention, an undercoat coating film is formed on a surface of a substrate, and sand is attached to the surface of the undercoat coating film to cover the surface of the sand. The intermediate coating film was formed over the entire surface of the undercoating paint, and the topcoating film was partially formed on the surface of the intermediate coating film. Sandwiched between the film and the intermediate coating film to hold the sand with high adhesion of both the undercoating film and the intermediate coating film, preventing the sand from peeling off from the substrate and not impairing the appearance. Is something that can be done. In addition, the entire substrate can be covered with a thick film formed by both the undercoating film and the intermediate coating film, which can reduce the influence of wind and rain on the substrate and improve the durability. By covering the surface of the film with the intermediate coating film, it is possible to prevent rain or the like from directly acting on the undercoating film and prevent deterioration of the undercoating film, thereby improving the durability of the undercoating film. It is possible.

According to a second aspect of the present invention, the temperature of the substrate is set to 70 to 95 ° C. and an undercoat paint having a viscosity of 30 ± 8 seconds is applied to the surface of the substrate with the Iwata cup NK-2. Then, sprinkle sand on the surface of the undercoat paint to adhere it, then apply the intermediate paint over the entire surface of the undercoat paint to cover the surface of the sand with the intermediate paint, then the intermediate paint Since the top coating film was partially applied on the surface of the roll with a roll, the temperature of the substrate was set to 70 to 95 ° C., and the viscosity of the base coating material was adjusted to 30 ± 8 seconds with the Iwata cup NK-2. It is possible to prevent the undercoat paint from hardening before spraying the sand, and it is possible to firmly attach and hold the sand to the undercoat paint, and when the intermediate coat paint is applied to the surface of the undercoat paint, the sand undercoats Do not peel off from the paint Is what you can do. Furthermore, since the intermediate coating material was applied over the entire surface of the undercoating material to cover the surface of the sand with the intermediate coating film, when applying the overcoating material, the sand should be applied without touching the roll directly. Even when the roll is in contact with the low-hardness intermediate coating, the top coating can be applied, the wear of the roll can be reduced, the frequency of roll replacement can be reduced, and the burden of roll maintenance can be reduced. Can be made smaller.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a building board of the present invention.

FIG. 2 is a schematic view showing an embodiment of a method for manufacturing a building board of the present invention.

FIG. 3 is a partially cutaway front view showing the Iwata cup NK-2.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Substrate 2 Undercoat coating 3 Sand 4 Intermediate coating 5 Top coating 6 Roll

Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B05D 5/06 B05D 5/06 Z D E04D 1/28 E04D 1/28 A E04F 13/14 102 8913-2E E04F 13/14 102A (72) Minor Kaiho, 1048 Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Works Co., Ltd. (72) Keiji Hattori, 1048, Kadoma, Kadoma City, Osaka, Matsushita Electric Co., Ltd.

Claims (2)

[Claims] 1. An undercoat coating film is formed on a surface of a substrate, sand is provided on the surface of the undercoat coating film, and an intermediate coating film covering the surface of the sand is formed over the entire surface of the undercoat paint. A building board characterized by being formed by partially forming a top coating film on the surface of an intermediate coating film. 2. The substrate temperature is set to 70 to 95 ° C., an undercoat paint having a viscosity of 30 ± 8 seconds is applied to the surface of the substrate with an Iwata cup NK-2, and then sand is applied to the surface of the undercoat paint. After spraying and adhering, then apply the intermediate coating over the entire surface of the undercoat and cover the surface of the sand with the intermediate coating, and then roll the top coating on the surface of the intermediate coating with a roll. A method for manufacturing a building board, which is characterized by applying a coating.