JP3297294B2 - Flat roof material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flat roofing material,
In particular, the present invention relates to a flat roof material that is roofed in a state in which a lower layer is partially overlapped with a higher layer.

[0002]

2. Description of the Related Art Conventionally, as a flat roofing material of this type, a flat inorganic plate such as a fiber reinforced cement board mixed with a fiber substance has been frequently used. When these flat roofing materials are installed on the roof, they are installed in a row in a row parallel to the roof ridge, and then in the second row, on the ridge side of the flat roofing material in the first row The parts are partially overlapped and the roofing work is shifted by about half in the left-right direction, and thereafter, the third and subsequent rows are similarly finished by partially shifting the roofing work.

[0003] In the roofing work, the flat roofing material in each row is roofed by overlapping a considerable portion in the vertical direction (toward the eaves) in order to prevent infiltration of rainwater. There has been a problem that rainwater easily penetrates into the interior due to phenomena or due to blowing during wind and rain. In addition, rainwater infiltrates from the abutting portions of the flat roof material in the horizontal direction, spreads in the horizontal direction due to capillary action, and leaks from nail holes for fixing to the roof in some cases.

In order to prevent the rainwater from spreading in the horizontal direction due to the capillary action, a large number of vertically continuous grooves are formed on the superposed upper surface to prevent the rainwater from spreading in the horizontal direction. There has been proposed a flat roof material which prevents water leakage by preventing it (Japanese Utility Model Laid-Open No. 60-35817).

[0005]

SUMMARY OF THE INVENTION The present inventors have been conducting research and development on flat roofing materials. However, in this type of roofing materials, it is necessary to form a water-repellent coating on the surface of an exposed portion. Is effective in facilitating the flow of rainwater, but in general, a highly water-repellent paint is expensive, which causes an increase in production cost. In addition, in the case of a flat roofing material in which a large number of vertically continuous grooves are formed on the upper surface to be superimposed, it is possible to prevent the spread of rainwater by the capillary phenomenon in the horizontal direction, but Cannot always provide a sufficient effect.

[0006] An object of the present invention is to eliminate the above-mentioned disadvantages of the conventionally used flat roof material, and more specifically, to effectively prevent rainwater from entering upstream. An object of the present invention is to provide a flat roofing material which can be manufactured at a lower cost than conventional ones.

[0007]

The flat roofing material according to the present invention for solving the above-mentioned problems has a coating layer having a small contact angle with water and a coating layer having a large contact angle with water, at least in an exposed portion. Are arranged in the horizontal direction. The flat roofing material body may be a material that forms the main body of a conventional flat roofing material body of this type,
It may be a fiber-mixed cement board containing cement mixed with pulp fibers as a main component, a cement calcium silicate board, a slag cement perlite board, an asbestos cement board, or the like.

[0008] According to the flat roofing material of the present invention, at least the contact angle of the coating layer to water at the exposed portion is partially different. In other words, when rainwater infiltrates into the overlapped portion due to rainwater blowing or capillary action, the exposed portion below the location where water leakage easily occurs is a coating layer having a large contact angle with water, and other In the exposed part, a coating layer having a smaller contact angle with water is formed. Preferably, an exposed portion located below a nail hole portion for fixing the flat roof material to a field board or the like, or a lower portion in a portion where a portion where the flat roof material of the upper row is butt-connected is located The exposed portion of the flat roofing material in the row is a coating layer having a large contact angle with water.

[0009] In the coating layer portion having a large contact angle with water, rainwater droplets easily flow round due to surface tension,
Runs down easily. For this reason, infiltration of rainwater at that portion is suppressed, and it is possible to prevent rainwater from reaching a location where water leakage is likely to occur, such as a nail hole portion. In addition, joints and warpage of the ends due to dimensional shrinkage occur due to temporal changes after construction at the butted part, and rainwater gathers at that part, which tends to be a rainwater flow path, but compared to other parts, the downstream part of the butted part By forming a coating layer having a large contact angle with water on the exposed portion, rainwater easily flows down, and it is possible to prevent a decrease in durability due to water accumulation and adhesion of dust and dust.

That is, according to the flat roofing material of the present invention, although only a part of the exposed part is formed of a coating film which is expensive and has a large contact angle with water (that is, high water repellency), It is possible to achieve water resistance and waterproofness that is substantially the same as the conventional flat roof material with a water-repellent paint coating on the entire exposed part, and the amount of expensive paint used is reduced, so low manufacturing cost Thus, a flat roof material that can withstand practical use can be obtained.

In a preferred embodiment of the present invention, the coating layer having a small contact angle with water and the coating layer having a large contact angle with water have different hues. As a result, it is possible to easily obtain a high-class flat roof material exhibiting a small split feeling. In this case, it is particularly preferable that the coating layer having a smaller contact angle with water and the coating layer having a larger contact angle with water are located at equal intervals. As a result, it is possible to present subdivided portions having equal intervals after construction, and it is possible to further provide a sense of subdivision.

In the present invention, the paint for forming the coating film is
Paints of the same kind or different kinds of paints may be used, but as described above, paints forming at least one coating film have a higher contact angle to water than paints forming other coating films. Must be larger. The method of adjusting the contact angle to water is arbitrary, but can be easily achieved by changing the types and amounts of the components of the paint for forming the coating film. Examples of differentiating components include a paint for forming a coating film having a large contact angle with water, such as a silicone-based antifoaming agent, a leveling agent, or an aqueous dispersion of wax as a compounding component. A material having a water function may be contained. Examples of different blending amounts include, for example, materials that have a function of uniformly dispersing a paint such as an extender, a pigment dispersant, an emulsifier, or a thickening / sedimentation preventive, which are usually mixed as a blending component in a paint. The blending amount may be larger in other paints than in a paint for forming a coating film having a large contact angle with water, so that the contact angle with water may be reduced.

In the coating of the exposed portion, a coating layer having a larger contact angle with water may be applied separately from another portion, and one coating layer is formed at least on the entire surface of the exposed portion. After that, the other coating layer may be formed on required portions by recoating. Further, the coating of the non-exposed portion is optional, and may be a non-water-repellent coating film or a water-repellent coating film. Further, different forms of the coating layer in the exposed portion may be continuously formed in the unexposed portion as they are. According to the experiments of the present inventors, by making the non-exposed part a non-water-repellent coating film, it was possible to effectively prevent the blowing up of rainwater during strong winds. Is desirably a non-water-repellent coating film.

[0014]

The present invention will be described below with reference to examples. FIG.
A flat roofing material body 10 made of a fiber-mixed cement board mainly composed of cement mixed with wood pulp and having the shape shown in FIG.
And two nail holes 3 on the left and right sides of the central portion 2a of the portion 2 corresponding to the exposed portion and the four nail holes 3 on the surface thereof.
In the lower portions 2b and 2c, A paint shown in Table 1 below (contact angle of 68 ° for a water coating) is applied to the lower portions 2b and 2c. Were respectively coated and dried to obtain a flat roof material.

In FIG. 1, line L corresponds to FIGS.
As shown in FIG. 1, the upper line is a line where the lower line and the upper line are overlapped when the upper line is partially overlapped with the lower line. In FIG. And the area above the line L is almost a non-exposed part. In this flat roofing material body 10, the distance L1 from the line L to the nail hole 3 is at least 50 mm, and the distance L2 to the shoulder is about 180 mm.

As shown in FIG. 2, the flat roofing material 10 is provided with an asphalt roofing 5 on a base plate 4 by an ordinary construction method, and the lower part 2 is placed on the eaves side, and the lower flat The upper flat roofing material 10b is partially overlapped with the roofing material 10a, and about half (Fig. 3a) or about 1/3 (Fig.
b) The roofing work is performed in a state shifted by about 1/4. The horizontal butting portion 10c (FIG. 2) of each flat roofing material 10 constitutes a "part where the upper row flat roofing materials are butted and connected" in the present invention.

In the coating, a water-based acrylic resin-based paint is applied as an undercoat over the entire surface of the flat roofing material 10 and dried, and then a moisture-curable solvent-based paint is applied to the lower half (the exposed portion) 2. And dried. Next, a B paint is applied to the lower half so as to cover the solvent type paint and dried, and furthermore, the lower part 2b, 2c of the nail hole 3 on the lower half becomes a butt portion when the roof is butted up. A paint of a different color was applied to only the lower part of the part (the center part in the width direction in this example) 2a and dried. On the other hand, a test body prepared by applying only the B paint to the lower half and drying was prepared as a comparative product.

[0018]

[Table 1]

[Comparative experiment] The flat roofing materials of the manufactured example product and the comparative product were installed in a roofing state as shown in Fig. 3a. The inclination angle was about 17 ° and the roof slope was 3 dimensions. From above, a rainfall of 4 ml / min is equivalent to a wind speed of 30 m / min.
Water is sprayed under the conditions of seconds, the permeation state of the lower part of the nail hole, the butt joint, and the other parts (water climbing distance: the eaves from the lower end (eave tip side) of the overlap of flat roof material at each part The distance that water permeated toward the ridge side) was measured. Table 2 shows the results.

At the same time, the amount of water flowing down was measured, and the state of the flat roofing material surface (after rain) was observed 10 minutes after watering was stopped. Table 3 shows the results.
In addition, the amount of water flowing down is the same for both the example product and the comparative product.
The ratio of the other part to the butt connection part 10 was 7.

[0021]

[Table 2]

[0022]

[Table 3]

As shown in Table 2, the water climbing distance at the portion where the paint A was applied was lower than the position of the nail hole 3 and the water leakage was avoided. In addition, although the portion of the B paint also had a slightly longer water climbing distance, there was no water leakage, and it was found that this flat roof material could be used without any support. On the other hand, since the comparative product has a long water climbing distance at the butt connection portion, it can be understood that there is a risk of water leakage when a nail hole is provided in the vicinity thereof.

Further, as shown in Table 3, since the portion where the paint A is applied has a large amount of water flowing down and dries in a short time, dirt and dust are generated even in a place where a large amount of flowing water is expected such as a butt portion. Since there is no remaining, and the time of contact with water is shortened, the durability as a flat roofing material is not reduced. On the other hand, since the comparative product is in a wet or damp state forever, dust and the like are easily attached.

[0025]

According to the present invention, it is possible to obtain a flat roofing material which is low in cost and has no problem in practical use and has high waterproof and water leakage resistance.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a flat roof material according to the present invention.

FIG. 2 is a diagram illustrating a state in which a flat roofing material is laid on a roof.

FIG. 3 is a view for explaining a flat roof material being roofed.

[Explanation of symbols]

10: flat roof material, 1: upper part (overlapping part), 2
... lower part (exposed part), 3: nail hole, A: coating film with large contact angle to water, B: coating film with small contact angle to water

Continuation of the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) E04D 1/00-1/34 E04D 3/00-3/40 B05D 7/00

Claims (4)

(57) [Claims] 1. A flat roofing material that is roofed in a state in which a lower one is partially overlapped with a higher one,
A flat roofing material comprising a coating layer having a small contact angle with water and a coating layer having a large contact angle with water are arranged laterally at least in an exposed portion. 2. A nail hole for fixing a flat roof material, wherein a nail hole is formed in a non-exposed portion at a position above a portion where a coating layer having a larger contact angle with water is disposed. The flat roof material according to claim 1, 3. The exposed portion at the portion where the portion where the flat row roofing material of the upper row is butt-connected is located,
The flat roofing material according to claim 1 or 2, wherein the coating layer has a larger contact angle with water. 4. The flat roofing material according to claim 1, wherein the coating layer having a small contact angle with water and the coating layer having a large contact angle with water have different hues. .