JP2006348617A - Manufacturing method for building backing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce variation in the strength of a building backing material, and to prevent a surface waterproof layer and an uneven layer from being cracked by drying or separated. <P>SOLUTION: The building backing material is manufactured as follows: the waterproof layer 3 is provided on the surface of a base plate 2 which is composed of a fiberboard; a water-based liquid is applied as a pretreatment agent onto the waterproof layer 3, so that a pretreated layer can be formed; after that, the waterproof layer is formed; and the uneven layer 4 is formed on the waterproof layer. Preferably, the pretreated layer is formed by applying the pretreatment agent onto the surface of the base plate and making the pretreatment agent permeate the surface of the base plate, while pressing the pretreatment agent against the surface of the base plate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a building base material, and more particularly to a method for manufacturing a building base material suitable for directly applying a decorative coating material such as cement mortar or plaster thereon.

On top of that, as a foundation material for construction that is suitable for directly applying decorative coating materials such as cement mortar and plaster, a waterproof layer is provided on the surface of a substrate made of plywood or fiberboard, and inorganic aggregate is further formed thereon. The thing provided with the uneven | corrugated layer which consists of latex cement containing is known by the following patent documents 1, 2, for example.
Japanese Utility Model Publication No. 56-18667 Japanese Patent Publication No.59-12825

  However, with regard to building base materials that use plywood as a substrate, it is becoming difficult to obtain high-quality plywood veneers due to the depletion of wood resources. Good quality veneer has less variation in specific gravity between the veneers and less specific gravity depending on the location of the same veneer. However, since such high quality veneer is becoming difficult to obtain, the variation in specific gravity is large. A plywood manufactured from a single plate must be used.

  Further, the rate of change in the water absorption length of the plywood is greatly different from the expansion rate in the direction perpendicular to the expansion rate in the direction parallel to the fiber direction of the surface veneer with about twice. Since building base materials are often placed in various adverse environments such as high dryness and high temperature and humidity, when such plywood is used as a substrate, the waterproof layer or uneven layer is dried due to the expansion and contraction of the plywood having large anisotropy. There was a risk of cracking and peeling.

  The above-mentioned patent document also describes the use of fiberboard as a substrate for building foundation materials, but the waterproof layer and the uneven layer are prone to cracking and peeling due to bending during handling such as transportation and construction. In addition, for reasons such as economic reasons (increased costs), this type of building base material using a fiberboard as a substrate has not yet been commercialized.

  Therefore, the problem to be solved by the present invention is to provide a drastic solution to the depletion of wood resources, to reduce the variation in strength in the building base material, and to dry and peel off the waterproof layer and the uneven layer. Is to prevent.

  In order to achieve the above object, the present invention provides a waterproofing method in a manufacturing method of a building base material in which a waterproof layer is provided on a surface of a substrate formed from a fiberboard, and an uneven layer is further provided on the waterproof layer. Before forming the layer, a pretreatment layer is formed by applying an aqueous liquid as a pretreatment agent to the substrate surface.

  By using a fiberboard as the substrate of the building base material, the above-mentioned problem of resource depletion is alleviated, and the difference in direction of the substrate and the difference in expansion and contraction are eliminated, making the surface waterproof layer dry and Peeling can be prevented.

  Furthermore, it is preferable that the fiber board used as a substrate of a building foundation material has a thickness of 4 to 15 mm. When the thickness of the fiber board is less than 4 mm, the fiber sheet is too thin and the absolute strength as a structural material is insufficient. When the thickness of the fiberboard exceeds 15 mm, the strength as a structural material becomes large, but on the other hand, the lightness is impaired and handling and construction become difficult. In addition, a building base material using such a thick fiberboard as a substrate has to use long and thick nails and screws for fixing, resulting in poor nailing or screwing.

  The fiber board includes a medium density fiber board (MDF) manufactured by a dry process and having a specific gravity of 0.35 or more as defined in JIS A5905, and a hard fiber board manufactured by a wet process and having a specific gravity of 0.80 or more ( From among HB) and the like, those satisfying the requirements of the above thickness range are preferably selected and used as the substrate for the building foundation material of the present invention.

  The fiberboard used in the present invention preferably has an average specific gravity of 0.5 to 1.05. When the average specific gravity is less than 0.5, the hardness of the fiberboard itself is insufficient, and the strength and rigidity as a structural material are insufficient. If the average specific gravity exceeds 1.05, the fiberboard itself becomes too hard and the nailing or screwing required as a building base material deteriorates, and the hot pressure during the production of the fiberboard Conditions become strict and cost increases.

  Further, in the thickness direction of the fiberboard, a center layer and front and back hard layers having higher specific gravity and water impermeability than the center layer are provided, and the front and back hard layers having high specific gravity are fibers. It is exposed on the front and back of the board. The specific gravity of the hard layer is not less than 0.7 in order to give water impermeability and increase the surface hardness to improve the scratch resistance, and when the specific gravity is excessively high, the nailing property and screwing property are also deteriorated. To 1.2 or less.

  Further, it is preferable that the fiberboard as the substrate is previously subjected to treatments such as insect proofing, ant proofing, mold prevention, and antiseptic which are generally performed. A chamfered portion that is chamfered at an angle of 30 to 60 degrees with respect to the surface may be formed in the mouth of the substrate.

  When the architectural base material produced according to the present invention is used as an architectural base material for a wall that forms an outer wall, it is preferable to use MDF as a substrate among fiberboards. The reason is as follows.

  Substrates for building base materials used for outer walls due to condensation water generated in the walls due to temperature differences between the outdoor side and indoor side of the building wall, rain water entering from the outside, sunlight irradiation to the outer wall surface, etc. The water content of fluctuates greatly, and this variation is repeated over a long period of time. In MDF, an adhesive is added to wood fibers that are being sent in the manufacturing process, and the contact between the wood fibers is three-dimensionally fixed with an adhesive, whereas hardboard is an adhesive. The wood fiber is molded in a state where the wood fibers are simply entangled with each other. For this reason, when the moisture content changes over a long period of time, the MDF has a small amount of contraction and expansion and is excellent in maintaining the initial state. Problems such as dry cracking and peeling of the waterproof layer and the uneven layer or swelling of the hard board substrate itself are likely to occur. For these reasons, it is preferable to use MDF among the fiberboards as the substrate of the building foundation material for the outer wall.

  When molding MDF, synthetic resin adhesives such as phenols, urethanes, melamines, urea / melamines and acrylics, and natural adhesives such as tannins are used alone or in any combination. Then, if necessary, a water-resistant sizing agent such as paraffin, wax, rosin, coumarone is added to obtain MDF that satisfies the above-mentioned requirements.

  In the present invention, before the waterproof layer is formed on the surface of the substrate, the pretreatment layer is formed by applying a pretreatment agent comprising an aqueous liquid to the substrate surface. Examples of the aqueous liquid constituting the pretreatment agent include water, acrylic resin, vinyl chloride resin, urethane resin, epoxy resin, ethylene vinyl acetate resin, urea resin, resorcinol resin, unsaturated polyester resin, and vinyl acetate resin. Synthetic rubber emulsions such as synthetic resin emulsions, acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), methyl methacrylate butadiene rubber (MBR), chloroprene rubber (CR) and the like can be used alone or in any mixture. By using the same material as the waterproofing agent that forms the waterproof layer as the pretreatment agent, the familiarity between the pretreatment layer and the waterproof layer is improved, and the adhesion strength thereof can be increased.

  In applying the pretreatment agent, it is preferable to apply the pretreatment agent while pressing it against the substrate surface. In this way, the pretreatment agent can easily penetrate into the substrate, the water repellency expression on the substrate surface is suppressed, the waterproofing agent can be uniformly applied to the entire surface of the substrate, and the waterproof layer can be uniformly formed. it can. In order to apply the pretreatment agent to the substrate surface while allowing it to penetrate into the substrate, it is preferable to apply the pretreatment agent using, for example, a roll coater or a spreader. For example, when a roll coater is used, the roll with the paint attached to the surface rotates while pressing the substrate surface, so that the pretreatment agent penetrates into the substrate by pressing the roll while feeding the substrate in the traveling direction. Can be made.

The waterproof layer is formed by applying a waterproofing agent made of a synthetic resin, a synthetic rubber latex, or an emulsion thereof alone or arbitrarily mixed on a pretreatment layer on the substrate surface with a coating device such as a roll coater or a flow coater. It is formed by applying uniformly and drying. The application amount is, for example, 120 to 250 g / m ² , and the drying condition is, for example, 80 degrees for 5 to 10 minutes. Synthetic resins such as acrylic resins and vinyl chloride resins or any mixture thereof, and synthetic rubber latexes such as styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), methyl methacrylate butadiene rubber (MBR), chloroprene rubber (CR), etc. One kind or any mixture of these can be used. In the waterproof layer, bituminous substances such as tar and asphalt, and additives such as extenders and dispersants such as clay, talc, calcium carbonate, perlite, and metal powder may be added and mixed. The waterproof layer may be formed on the back surface of the substrate by applying a material having the same or different composition as the waterproof layer on the front surface side or by attaching a waterproof film. Further, a waterproof layer can be formed in the same manner on the front end of the substrate.

  It is preferable to form the waterproof layer by applying the waterproofing agent before the pretreatment agent is dried. By applying the waterproofing agent before the pretreatment agent is dried, the familiarity between the pretreatment agent and the waterproofing agent is improved, and the adhesion strength is increased. If the waterproofing agent is applied after the pretreatment agent has been dried, the pretreatment layer repels the waterproofing agent, making it difficult to form the waterproofing layer.

  The uneven layer is formed on the surface of the waterproof layer on the surface side, cement such as Portland cement and white cement, synthetic resin, latex or bituminous material, aggregate such as calcium carbonate and silica sand, methylcellulose, surfactant, It is formed by applying a molding aid such as a foaming agent and a mixture of water in layers with a coating apparatus such as a roll coater and drying. The composition of the mixture forming the uneven layer is, for example, 150 parts of cement (parts by weight, the same applies hereinafter), 150 parts of aggregate, 40 parts of latex, 40 parts of emulsion, 0.3 part of methylcellulose, and 1 part of surfactant. The synthetic resin, latex or bituminous substance in the concavo-convex layer is preferably the same type as that used for the surface waterproof layer, so that the intermolecular attractive force between the substance in the waterproof layer and the substance in the concavo-convex layer. Works to increase their adhesion strength. The formation of the unevenness is, for example, a mixture in an uncured state immediately after application of a meshing roll corresponding to the unevenness of the uneven layer to be formed or a net winding roll wound with a net corresponding to the unevenness on the surface of the waterproof layer. It can be formed by rolling on the coated surface. The height of the concavo-convex layer is about 2.5 mm at the maximum.

  The architectural base material of the present invention manufactured as described above is mass-produced in advance in a factory, and fixed to a structural material such as a pillar or a stud by nailing or the like when constructing an outer wall, and the base materials for construction are brought together. After filling the part (joint part) with the caulking agent without any gap and fixing the net-like material so as to completely surround the caulking agent, mortar is applied to the entire surface to form a mortar layer.

  As the caulking agent, an acrylic resin, urethane resin, silicon, modified silicon, polysulfite, or the like can be used as a main component.

  The net-like material is fixed so as to cover the caulking agent in the joint portion, reinforces the mortar to be applied later, and prevents cracking. The net-like material is arbitrarily selected from organic fibers or inorganic fibers such as polyamide fibers, acrylic fibers, polyethylene fibers, polypropylene fibers, polyvinyl alcohol fibers, cotton fibers, alkali-resistant glass fibers, and carbon fibers. A net obtained by weaving one or more kinds of fibers can be used. Particularly, an acrylic fiber net, an alkali glass fiber net, a cotton fiber net, a polyvinyl alcohol fiber net, and the like are preferably used.

  The mortar is, for example, a cement mortar obtained by kneading cement, sand, latex, and water. The thickness of the cement mortar is applied so as to be in the range of about 7 mm to 20 mm according to the fireproof performance required for the wall structure of the outer wall.

  Furthermore, according to the present invention, before the waterproof layer is formed on the surface of the fiberboard substrate, the pretreatment layer is formed by applying a pretreatment agent made of an aqueous liquid to the substrate surface. The water repellency expression on the surface, which is a feature, is suppressed, and when a waterproofing agent is applied to form a waterproofing layer thereon, the waterproofing agent is not repelled, and the waterproofing layer is uniformly formed without unevenness be able to.

  A building base material 1 according to an embodiment of the present invention shown in FIG. 1 uses MDF as a substrate 2 and forms a pretreatment layer 3 by applying a pretreatment agent comprising an aqueous liquid on the surface thereof, and is waterproof on the surface. A waterproofing layer 3 is formed by applying an agent, on which 150 parts of cement (parts by weight, the same applies hereinafter), 150 parts of aggregate, 40 parts of latex, 40 parts of emulsion, 0.3 part of methylcellulose, surfactant 1 The concavo-convex layer 5 is formed by applying a mixture of parts. The MDF used for the substrate 2 has a thickness of 9 mm and an average specific gravity of 0.8. A chamfered portion 6 is formed by chamfering the front side of the quadruple end of the MDF substrate 2. The height h of the concavo-convex layer 5 is about 2 mm and has an irregular concavo-convex pattern.

  A mortar outer wall structure using this building base material 1 is shown in FIG. That is, the building base material 1 is put in a state of being abutted on the column 7 with a gap and fixed with a nail 8, and then the acrylic caulking agent 9 is filled in the spaced joints without any gaps. After the net-like object 10 is fixed so as to completely surround the agent 9, mortar is applied to the entire surface to form the mortar layer 11, and the outer wall is configured.

  The architectural base material 1 ′ according to another embodiment of the present invention shown in FIG. 3 is substantially the same as the architectural base material 1 according to the embodiment of FIG. 1, but the waterproof layer 12 is also provided on the back side of the MDF substrate 2. Is different in that it is formed. According to this embodiment, water absorption from the front surface side and the back surface side of the MDF substrate 2 is suppressed, so that the MDF substrate 2 itself does not warp even when used for many years.

It is sectional drawing which shows the foundation | substrate material for construction by one Embodiment of this invention. It is a construction state figure at the time of carrying out mortar outer wall construction using this building ground material. It is sectional drawing which shows the foundation | substrate material for construction by other embodiment of this invention.

Explanation of symbols

1 Building material for construction 2 Fiberboard (MDF) as a substrate
3 Pretreatment layer 4 Waterproof layer 5 Concavity and convexity layer 6 Chamfered portion 7 Pillar 8 Nail 9 Caulking agent 10 Net-like material 11 Mortar layer 12 Waterproof layer on the back side

Claims (2)

In the method of manufacturing a building base material in which a waterproof layer is provided on the surface of a substrate formed of fiberboard, and an uneven layer is provided on the waterproof layer, the substrate surface is pretreated before the waterproof layer is formed. A method for producing a building base material, comprising applying a water-based liquid as an agent to form a pretreatment layer. A method for producing a building base material, wherein a pretreatment layer is formed by applying and penetrating a pretreatment agent against a substrate surface.

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