JP4559287B2 - Architectural base material - Google Patents

Description

  TECHNICAL FIELD The present invention relates to an architectural base material used by being fixed to a structural material such as a pillar or a stud in order to constitute an inner wall and an outer wall of a building, in particular, an outer wall of a wooden building.

As a conventional architectural base material, for example, as shown in the following patent document, a waterproof layer is provided on the surface of plywood or fiberboard, and an uneven layer made of latex cement containing inorganic aggregate is provided thereon. It has been known.
Japanese Utility Model Publication No. 56-18667 Japanese Patent Publication No.59-12825 Japanese Utility Model Publication No. 58-18510

  However, when these conventional building base materials are used for the outer wall of a building, the magnitude of shrinkage / expansion due to the moisture content change of the plywood or fiberboard of these building base materials is the mortar layer provided on the uneven layer Because it is larger than the size of shrinkage / expansion due to the change in moisture content, if it is exposed to a poor environment such as high dryness or high temperature and humidity for a long time, the warpage of the building base material itself due to the dimensional change of plywood or fiberboard, mortar layer There was a risk of dry cracking / peeling or dry cracking at the joint between the building base materials.

  Therefore, the problem to be solved by the present invention can prevent the occurrence of warpage, dry cracking and peeling of the mortar layer even when exposed to a poor environment such as high dryness or high temperature and humidity for a long time. An object of the present invention is to provide a construction base material having a new structure.

In order to achieve the above object, the present invention according to claim 1 provides a surface-side waterproof layer on the surface of a substrate made of fiberboard, and further provides an uneven layer on the surface-side waterproof layer, and the back surface of the substrate. In the building base material provided with the back side waterproof layer , the substrate is provided with a chamfered portion, the surface side waterproof layer is provided so as to cover the chamfered portion and the mouth, and the uneven layer is the surface side waterproof layer. To a part of the chamfered portion with a maximum height of 2.5 mm .

  When the outer wall is formed using the building base material of the present invention, since the waterproof layer is provided on both the front and back sides of the substrate made of fiberboard, the moisture content change of the fiberboard accompanying the surrounding humidity change is suppressed. In addition, the rate of change is slow. On the other hand, the mortar layer provided on the concavo-convex layer has a relatively small water content change after being dried in a natural environment. Therefore, since the dimensional change rate of the fiberboard and the mortar layer in the natural environment is small and does not show a significant difference, the warping of the building base material due to this, the cracking / peeling of the mortar layer, or the building base materials It is possible to prevent dry cracks and the like at the joints.

  FIG. 1 shows an architectural base material 1 according to an embodiment of the present invention, in which a surface-side waterproof layer 3 is provided on the surface of a substrate 2, and a concavo-convex layer 4 is provided thereon. A side waterproof layer 5 is provided.

  The substrate 2 is made of a fiber board, and a medium density fiber board (MDF) manufactured by a dry process, a hard board (HB) manufactured by a dry process or a wet process, or the like can be used.

  The fiberboard is provided with a center layer and a hard layer on the front side and the back side that are higher in specific gravity than the center layer and highly impermeable compared to the center layer in the thickness direction, The high specific gravity hard layer is exposed on the front and back surfaces. Since the fiberboard obtained after heating and pressing in the fiberboard manufacturing process has a specific gravity distribution from the outermost layer portion with a small specific gravity to the hard layer portion with a high specific gravity, the region of the predetermined thickness range on the front and back surfaces thereof It is preferable to expose the hard layer having a high specific gravity on the front and back surfaces of the fiberboard by removing the outermost layer portion having a low specific gravity by sanding or the like.

  The specific gravity of the center layer has a specific gravity of 0.4 or more, more preferably 0.6 or more in order to give sufficient strength to the fiberboard, and its upper limit is about 0.75, more preferably 0 in order to give light weight. About 7 That is, the specific gravity of the center layer is in the range of 0.4 to 0.75, more preferably about 0.6 to 0.7. The specific gravity of the hard layer is 0.8 or more, more preferably 1.0 or more in order to improve the scratch resistance by imparting water impermeability and increasing the surface hardness, and if the specific gravity is excessively high, the impact resistance Even if the performance deteriorates, it becomes a brittle plate material, so it is 1.4 or less, more preferably 1.2 or less. That is, the specific gravity range of the hard layer exposed on the front and back is about 0.8 to 1.4, more preferably about 1.0 to 1.2. In addition, if the specific gravity difference between the central layer and the hard layer exposed on the front and back is small, sufficient bending strength cannot be obtained unless the thickness of the hard layer on the front and back is made as thick as the central layer. On the other hand, if the specific gravity difference is too large, a significant difference in mechanical properties occurs between the center layer and the front and back hard layers. For example, when the surface is subjected to a bending load, the front and back hard layers have a high specific gravity. For this reason, the wood fibers are in a dense state and shrinkage in the surface direction is unlikely to occur, whereas the center layer has a small specific gravity so that the wood fibers are in a sparse state and easily shrinks. Delamination tends to occur between the layer and the front and back hard layers. Therefore, the specific gravity difference between the center layer and the front and back hard layers is at least 0.1, more preferably 0.3 and 0.8.

  Since the front and back hard layers have a higher specific gravity than the center layer and the wood fibers are in a dense state, the water impermeable property is high and the water absorption into the plate material is remarkably reduced. Further, the hard layer has a specific gravity of about 0.8 to 1.4, more preferably about 1.0 to 1.2 as described above. By adding or containing about 2 to 8% by weight of a sizing agent such as rosin size, wax size, coumarone rosin size, asphalt size, etc., which imparts water resistance to each wood fiber that forms the fiber, its combined action This further improves the non-water permeability of the hard layer. Therefore, the moisture content change of the fiberboard placed in the natural environment is small, and the shrinkage of the fiberboard accompanying this is small, so that the waterproof layer is unlikely to dry or peel off.

The surface-side waterproof layer 3 is composed of, for example, latex such as butadiene acrylonitrile rubber (NBR), methacrylbutyl rubber (MBR), styrene butadiene rubber (SBR), and synthetic vinyl acetate resin, vinyl chloride resin, acrylic resin, chloropyrene resin, and the like. The mixture with the resin emulsion can be formed by coating the surface of the substrate 2 with a coating amount of, for example, 150 to 250 gr / m ² and drying and curing. In addition, an appropriate amount of flattened platelets such as flat talc and mica pieces, inorganic pigments, clay, barite (barite), metal powder and other bulking agents are added to this mixture as necessary. can do. The composition of this mixture is based on mixing equal amounts of latex and synthetic resin emulsion, and is appropriately adjusted according to the amount of other components added and the intended use of the building base material.

The uneven layer 4 includes, for example, aggregates such as calcium carbonate and silica sand, cements such as Portland cement and white cement, latexes such as SBR, MBR and NBR, vinyl acetate resin, vinyl chloride resin, acrylic resin and chloropyrene resin. After applying a mixture with a synthetic resin emulsion such as a concavo-convex shape on the surface of the surface-side waterproof layer 3 after curing at a coating amount of, for example, 700 to 1300 gr / m ² , Alternatively, it can be formed by rolling a net roll or the like wound with a net corresponding to the unevenness to an undried application surface immediately after application to form unevenness and then drying and curing. An appropriate amount of a surfactant, an antifoaming agent, or the like can be added to this mixture as necessary. An example of the composition of this mixture is 150 parts of aggregate (parts by weight, the same shall apply hereinafter), 150 parts of cement, 40 parts of latex, 40 parts of synthetic resin emulsion, 0.3 parts of methyl cellulose, and 1 part of surfactant. including. The height (h) of the uneven layer 4 is 2.5 mm at the maximum .

  The back side waterproof layer 5 can be formed in the same manner as the above-mentioned front side waterproof layer 3. These waterproof layers 3 and 5 may have the same composition or different compositions.

Such a building base material 1 is mass-produced in a factory in advance, and is fixed to a structural material such as a pillar or a stud by nailing or the like, and then mortar is applied on the uneven surface of the uneven layer 4 to construct a mortar. Form a layer. The mortar is, for example, a cement mortar obtained by kneading cement, sand, latex, and water. By applying this, a mortar layer having a thickness of about 10 mm is formed. The mortar layer shrinks by drying over time (days), but its dimensional change rate (dry shrinkage strain) is about (0.4 to 0.8) × 10 ⁻³ . Therefore, the dimensional change amount of the mortar layer in the case where the length of the building foundation material 1 is 1820 mm is 0.7 to 1.5 mm, which is so small as to be almost negligible.

  On the other hand, since the dimensional change rate of the MDF itself constituting the substrate 2 is 0.03 to 0.06% in the length direction and the width direction per moisture content of 1%, the back side waterproof layer 5 is provided. If not, if the moisture content of the MDF changes by 5%, the dimensional change rate is 0.15 to 0.3%, and the dimensional change amount in the building base material 1 having a length of 1820 mm is 2.7. -5.5 mm. This dimensional change amount is much larger than the above-mentioned mortar dimensional change amount (0.7 to 1.5 mm), which is a cause of warping of the building base material 1 itself, dry cracking / peeling of the mortar layer, and the like. It becomes. However, since the backside waterproof layer 5 is provided together with the front side waterproof layer 3 in the building base material 1 of the present invention, the change in the moisture content of the MDF substrate 2 due to the humidity change in the surrounding environment is small enough to be ignored. Since the dimensional change rate (amount) is almost the same as that of the mortar layer, warpage of the building base material 1 itself, dry cracking / peeling of the mortar layer, or drying at the joint between the building base materials. Cracks and the like can be prevented.

  As shown in FIG. 2, the chamfered portion 6 is formed by chamfering the surface side of the wood mouth 7 of the substrate 2 at an angle of 30 to 60 degrees with respect to the surface, and the surface-side waterproof layer 3 is formed on the surface of the substrate 2. In addition, it is preferable that the chamfered portion 6 is extended from the chamfer 7 so as to cover them. Moreover, the uneven | corrugated layer 4 is formed so that it may cover in part from the surface of the surface side waterproofing layer 3 formed in this way on the chamfering part 6. With such a configuration, not only the surface of the substrate 2 but also the entire surface of the chamfered portion 6 and the lip 7 of the four circumferences are covered with the surface side waterproof layer 3, and the entire back surface thereof is covered with the back surface side waterproof layer 5. Therefore, the substrate 2 is hardly affected by the surrounding humidity change or the adhesion of water such as rainwater, and the moisture content change of the substrate 2 is extremely small.

  In FIG. 2, the V-shaped joint space is filled with a caulking joint material, and a net-like material such as glass fiber or synthetic resin fiber is provided so as to cover the surface of the coking joint material and its periphery. The mortar is applied to the surface of the building base material 1 after reinforcing the joints.

It is sectional drawing which shows the foundation | substrate material for construction by one Embodiment of this invention. It is sectional drawing which shows the joint part when this foundation material for construction is adjacently constructed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material for construction 2 Board | substrate which consists of MDF (fiber board) 3 Surface side waterproof layer 4 Concavity and convexity layer 5 Back side waterproof layer 6 Chamfer 7 Kiguchi

Claims (1)

In a base material for construction in which a surface side waterproof layer is provided on the surface of a substrate made of fiberboard, and an uneven layer is provided on the surface side waterproof layer, and a back side waterproof layer is provided on the back surface of the substrate, the substrate is chamfered. The surface-side waterproof layer is provided so as to cover the chamfered portion and the lip, and the uneven layer is formed with a maximum height of 2.5 mm from the surface-side waterproof layer to a part of the chamfered portion. building base material, characterized in that that.

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