JP2620720B2 - Wood fiber base plate for construction and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is a mortar wall or siding having excellent heat insulation and moisture absorption / desorption properties, and exhibiting a wall magnification of 2 or more in a 2 × 4 (two-by-four) construction building. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood fiber base plate used as a base material and a method for manufacturing the same.

[Conventional technology and its problems]

Conventionally, as an architectural base plate such as a wall base made of a wood fiber board, a sheathing and insulation board (hereinafter, referred to as a sheathing board), which is rich in heat insulation and moisture absorption and desorption, for the purpose of heat insulation and dew condensation prevention. Have been.

This sheathing board is formed by a wet papermaking method that has a low density and good entanglement of fibers, and is widely used as a wall base plate having a high heat insulating effect when used as a base of a mortar wall or a siding material.

In such a sheathing board, a JIS A5905 stipulated 12 mm thick sheathing board is a notification from the Ministry of Construction No. 1100.
No., etc., in buildings of the 2 × 4 construction method or the conventional frame construction method, the shear strength of the wall magnification of 1 has been certified as a heat-insulating material under the outer wall and as a load-bearing wall. This is equivalent to twice the strength of the load-bearing wall of a wall with a tension of 0.5), but the strength is lower than that of structural plywood, and the strength of the building is not satisfactory in terms of design. Was.

On the other hand, structural plywood is excellent in strength, so that 2 × 4
The construction method has been certified to have a strength of 2.5mm for Class 2 structural plywood with a thickness of 7.5mm, and a wall magnification of 3.5 for Class 1 structural plywood with a thickness of 9mm. Those with a thickness of 5 mm or more are certified to have a wall magnification of 2.5, but are inferior to the above-mentioned sizing board in terms of heat insulation and moisture absorption and desorption, and therefore are disadvantageous for heat insulation performance and prevention of dew condensation. In view of this, heat insulation was not sufficient.

The wall strength of a building such as the 2 × 4 construction method is calculated by a multiplier of the length of the load-bearing wall and the wall magnification. When a large opening such as a window is used, a wall plate having a high wall magnification is required. .

Therefore, increasing the wall magnification by increasing the strength without lowering the heat insulating property and the moisture absorption / desorption property of the sizing board, the durability of the building can be satisfied, the livability can be satisfied, and the opening can be increased. This has the advantage that the degree of freedom of the design plan is expanded.

In order to double the wall magnification of the sheathing board, it can be achieved by making the thickness 24 mm and making it twice as thick as the conventional one, but the thickness of the base material is made thick like this This leads to a decrease in workability and an increase in price, and is not a satisfactory base material.

Therefore, it is necessary to improve the strength without significantly increasing the thickness, but when forming a wood fiber board excellent in strength by a wet papermaking method, simply increase the amount of the binder mixed into the wood fiber. Even if papermaking is performed, the strength cannot be improved if the binder flows out into the water, and if the wood fiber is mixed in such a way that the surface of the wood fiber is covered with the binder, the absorption of the wood fiber can be prevented. There is a problem that the moisture release property is reduced.

On the other hand, powdered phenolic resin is known as a binder that has excellent bonding strength and water resistance and has a low outflow during papermaking. By adding a large amount of this powdered phenolic resin, it is conceivable to make a wood fiber board having high strength. .

However, since the powdered phenolic resin having a small particle diameter moves in the mat along with the movement of water when the wet mat is dehydrated, it is difficult to uniformly fix the phenolic resin at the intersection of the entanglement of the wood fibers. When the amount is increased, the dispersion becomes uneven and the warpage and the strength unevenness are easily caused. Also, the phenolic resin increases its fluidity by heating and melting during drying, so that it flows from the entanglement intersection and flows easily to the fiber surface, and the bonding effect equivalent to the mixing amount cannot be exhibited, so make sure that the mixing amount is extremely large. Had to be economically disadvantageous.

Therefore, utilizing the resin floc formation of polyacrylamide (anion) and a sulfate band (cation), which are polymer fixing agents, the resin floc is wrapped with the powdered phenolic resin and fixed at the intersection of wood fibers. In order to improve the fixing yield and prevent flow during melting, the amount of polyacrylamide increases, the diameter of the floc increases, the viscosity of the slurry increases, and the fiber mat adheres to the papermaking net. In addition, there is a possibility that the flocks may hinder the entanglement of the wood fibers, causing a variation in strength.

In addition, the resin floc due to the polymer fixing agent, because the dispersion in the slurry is likely to be non-uniform as described above,
Even if a large amount of powdered phenol resin is added, there is a problem that the resin is not uniformly adhered to the wood fiber as a whole, and a partial resin mass is formed.

The present invention has solved such a problem, and by efficiently melting and fixing the powdered phenolic resin to the entanglement intersections of the wood fibers without significantly increasing the thickness dimension of the sizing board, the heat insulating property and the absorption and release of heat are achieved. It is an object of the present invention to provide a wood fiber architectural base plate excellent in wettability and capable of exhibiting a strength with a wall magnification of 2 or more, and a method for producing the same.

[Means for solving the problem]

In order to achieve the above object, the wood fiber architectural base plate of the present invention has a melting point of 70 to 90 with respect to 100 parts by weight of the wood fiber.
Powdered phenolic resin with particle size 200 mesh passing at 10 ~ 4
0 parts by weight and a powdery petroleum resin 5-20 having a melting point of 100-120 ° C. and a particle size of 48 mesh and not passing through 200 mesh.
Part by weight and is a base plate for building made of wood fiber obtained by wet paper milling is mixed, the entangled portion of the wood fiber is adhered by melting and fixing of the phenolic resin and petroleum resin, the specific gravity is 0.35 to 0.4, It has a structure with a thickness of 10 to 15 mm and a strength of a wall magnification of 2 or more.

Further, as a method of manufacturing such a wood fiber architectural base plate, wood fiber 100 parts by weight, powder phenol resin having a melting point of 70 to 90 ° C. and a particle size of 200 mesh 10 to 40 parts by weight, melting point Is 100-120 ° C and the particle size passes through 48 mesh and 20
0 5% by weight of solid petroleum resin that does not pass through the mesh is wet-processed with a slurry obtained by mixing and stirring in water, and the wet mat after paper-making is gradually heated until the internal temperature of the mat reaches a temperature of 100 to 120 ° C. After being raised, the powder is heated and dried at a temperature not lower than the curing point of the phenol resin.

As the wood fibers constituting the base plate, softwood having a long fiber length is preferably used. In particular, pinewood fibers having a small water absorption expansion and a high strength are preferably used. By using such a wood fiber, since the fiber length is long, the number of entanglement intersections, that is, the number of entanglement points increases, the bending strength of the fiberboard is improved, and the phenol resin is efficiently fixed to the entanglement point, and the fiber is fixed. The shear force of the board is increased, resulting in a fiberboard with a high nail side resistance, which greatly affects the determination of the wall magnification.

The melting point of the powdered phenolic resin is as described above.
Those having a particle size of 70 to 90 ° C and a particle size of 200 mesh passing (200 mesh under) are used, and those having a curing point of 140 ° C or more, preferably 140 to 160 ° C are used. The reason for limiting the melting point and the curing point to within the above ranges is that it is difficult to efficiently melt and cure the wood fiber mat at the drying temperature of the wood fiber mat at the time of production with a resin having a melting point temperature equal to or higher than the above melting point.

The phenolic resin used may be either a novolak type or a resol type, but the novolak type is preferable because it has no free formalin and thus has no pollution, and has high strength after curing.

Further, if the mixing ratio of the powdered phenolic resin to the wood fiber is less than 10 parts by weight, the strength of the fiberboard obtained cannot be increased to a wall magnification of 2 or more, and if it exceeds 40 parts by weight, heat insulation as a wall base material is required. The content and the moisture absorption / desorption are reduced, so that it is added in the range of 10 to 40 parts by weight as described above.

On the other hand, the petroleum resin of the powder, the particle size and melting point is smaller than that of the phenolic resin, the flow-prevention effect on the phenolic resin is not exhibited, it is a requirement to use a particle size that does not pass through 200 mesh, If a particle having a large particle size that does not pass through the 48 mesh is used, the entanglement of the wood fibers in the slurry is impaired and the strength is reduced. Therefore, a particle having a particle size within the above range is used.

In addition, the molecular weight of this petroleum resin is less than 800, the adhesiveness is large, the dispersibility in water is poor, while if it is more than 2,000, the melting temperature is high and it becomes difficult to melt in the range of the drying temperature of the wood fiber, Since the bonding strength between fibers and the imparting of water resistance to the fiberboard become insufficient, those having a range of 800 to 2000 are used.

Furthermore, when the petroleum resin is melted before the phenolic resin powder during heating and drying of the wood fiber mat, the molten petroleum resin inhibits the close contact between the powdered phenolic resin and the wood fiber, and the petroleum having a weak bonding force at the entanglement point of the fiber. If the resin adheres first and melts before the powdered phenolic resin, the flow of the molten phenolic resin cannot be prevented, and the phenolic resin tends to flow from the entangled portion toward the fiber surface. Using a petroleum resin in the range of 100 to 120 ° C. higher than the powdered phenolic resin, the requirement is that the powdered phenolic resin is first melted at the intertwining point of the fibers, and then attached, and then the powdered petroleum resin is melted. Things.

If the mixing ratio of the petroleum resin is 5 parts by weight or less with respect to 100 parts by weight of the wood fiber, the prevention of the flow of the molten phenolic resin becomes insufficient, so that even if only a large amount of the powdered phenolic resin is added, it is bonded. Not enough strength, wall magnification 2
While it is not possible to obtain the strength of
When the amount is more than the weight part, a large amount of petroleum resin is fixed at the entanglement point of the wood fiber, and the fixing amount of the powdered phenol resin is reduced. As a result, it is impossible to obtain a fiberboard having a strength satisfying the wall magnification of 2, Must be added within the range of 5 to 20 parts by weight.

Recycled paper pulp and asphalt can be used as other additives, and when 0 to 30 parts by weight of recycled paper pulp is added to 100 parts by weight of wood fiber, the stiffness of the papermaking fiber mat is strengthened and handling during production is performed. When the asphalt is added in an amount of 0 to 10 parts by weight, water resistance and elasticity can be imparted to the fiberboard obtained with the petroleum resin.

[Function] In producing a wood fiber board, wood fiber, powdered phenol resin and solid petroleum resin are put into water, and the slurry is formed into a sheet. A large number of small-diameter powdered phenolic resins adhere efficiently to the entangled points of the wood fibers with the phenolic resins attached. When the wet mat thus obtained is heated and dried, the powdered phenolic resin having a lower melting point than the petroleum resin melts first due to the drying temperature of the mat, and adheres preferentially to the entanglement point of the wood fiber, and the powdered petroleum resin melts. Until that time, the flow is kept small, so that the phenolic resin is sufficiently adhered to the intersection of the entanglement of the wood fibers, and the phenol resin exerts the binding effect between the wood fibers without regret, and the petroleum resin melts thereafter. This strengthens the joints between the wood fibers to impart water resistance.

In this way, the binding strength between the wood fibers is increased without impairing the heat insulation and moisture absorption / release properties of the wood fiber board obtained by effectively adhering the phenol resin powder together with the petroleum resin to the intertwining points of the wood fibers, and increasing the specific gravity. However, it is possible to obtain a high-strength wood fiber architectural base plate that satisfies a wall magnification of 2 or more while maintaining the same ease of handling as a conventional sizing board with a light weight of 0.35 to 0.4 and a thickness of 10 to 15 mm. .

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[Example 1] 100 parts by weight of a wood fiber made of pine wood in water and a melting point of 70
Solid petroleum with a melting point of 100 ° C, a molecular weight of 960 and an average particle size of 100 (48 mesh under and not passing through 200 mesh) with 10 parts by weight of a powdered phenolic resin having a particle size of 200 ° C and a curing point of 150 ° C. A slurry is prepared by adding 5 parts by weight of a resin and mixing and stirring, and the slurry is formed by wet-paper-making method to obtain a wet mat of wood fiber, and the mat is heated to an internal temperature of 80 to 100 ° C. A first drying zone whose temperature has been adjusted so as to have a second drying zone where the internal temperature of the mat has been adjusted to 100 to 130 ° C, and a third drying zone which has been adjusted so that the internal temperature of the mat has become 150 ° C or higher. To 12% moisture content
It was dried to the following, then cooled to room temperature and cut to obtain a wood fiber base plate for construction having a size of 909 × 1818 mm and a thickness of 12.2 mm.

[Example 2] 12 parts by weight of the powdery phenol resin, 9 parts by weight of solid petroleum resin, and 3 parts of asphalt powder (particle size: 48 to 200 mesh) with respect to 100 parts by weight of the wood fiber.
After adding a part by weight and stirring and mixing in water to prepare a slurry, a base plate made of wood fiber for construction having the same shape under the same conditions as in Example 1 was obtained.

[Example 3] In Example 2, 20 parts by weight of the powdered phenol resin was used.
15 parts by weight of solid petroleum resin and 4 parts by weight of asphalt powder were used, and the other conditions were the same to obtain a wood fiber base plate for building having the same shape.

[Example 4] In Example 2, 25 parts by weight of the powder phenol resin was used.
20 parts by weight of solid petroleum resin and 5 parts by weight of asphalt powder were used, and the other conditions were the same to obtain a wood fiber base plate for building having the same shape.

[Comparative Example 1] 10 parts by weight of asphalt powder was added to 100 parts by weight of wood fiber, and a slurry was prepared by mixing and stirring in water to obtain a wet mat. Then, under the same conditions as in Example 1, By processing, a sheathing insulation board of the same shape was obtained.

[Comparative Example 2] 6 parts by weight of asphalt powder and 6 parts by weight of the same solid petroleum resin particles as in the above example were added to 100 parts by weight of wood fiber, and a slurry was prepared by mixing and stirring in water. After obtaining a wet mat, it was processed under the same conditions as in Example 1 and a sheathing insulation board (JI
SA 5905 standard product).

[Comparative Example 3] Polyacrylamide 0.03 to 100 parts by weight of wood fiber
15 parts by weight of the same phenol resin powder as in the above example, and mixing and stirring in water to form a slurry to obtain a wet mat, which was then treated under the same conditions as in Example 1 and the same. A wood fiberboard of the shape was obtained.

The physical properties of the wood fiber boards obtained in Examples 1 to 4 and Comparative Examples 1 to 3 are shown below.

In the above table, the racking test was calculated based on the test standard of ASTM E72, and the calculation of the wall magnification was performed based on the following equation approved by the Japan Residential Wood Technology Center.

Wall magnification = (shear strength at 1/300 radian deformation) x (1/13
0) × (1 / 1.82) × (reduction coefficient = 0.75) As shown in the above table, the wood fiber board in the example of the present invention has a specific gravity of 0.4 or less and the same thickness as a conventional base board of about 12 mm. It was confirmed that it had a performance with a wall magnification of 2 or more under the conditions of

〔The invention's effect〕

As described above, according to the wood fiber architectural base plate of the present invention, it has a wall magnification of 2 or more, which cannot be obtained with a conventional sizing board without impairing heat insulation and moisture absorption / desorption properties. In addition, a large opening such as a window of a building can be obtained, and the degree of freedom of a building design plan can be increased.

In the method of producing the base plate, during wet papermaking, first, wood fiber and a powdered phenol resin having a particle size of 200 mesh and a solid petroleum resin that does not pass through 200 mesh with 48 mesh are mixed and stirred. Therefore, when the slurry is formed to obtain a wet mat, a large number of powdered phenolic resins having a smaller diameter than the solid petroleum resin on the surface of the fixed petroleum resin having a large particle size,
The phenolic resin can be efficiently fixed to the intertwining points of the wood fibers in the attached state, and when the wet mat is heated and dried, the powdered phenolic resin having a melting point lower than that of the powdered petroleum resin depends on the drying temperature of the mat. And the phenolic resin adheres preferentially to the intertwining points of the wood fibers, so that the binding effect of the wood fibers by the phenolic resin can be fully exhibited, and the petroleum resin subsequently melts and establishes the connection of the wood fibers. Can be done.

In this way, the bonding strength between the wood fibers is increased without impairing the heat insulation and moisture absorption / release properties of the wood fiber board obtained by effectively attaching the phenol resin powder to the intertwining points of the wood fibers via the petroleum resin. , Specific gravity 0.35 ~ 0.4, thickness 10 ~ 15mm
It is possible to obtain a wood fiber architectural base plate having a high specific gravity and a thickness dimension and a wall magnification of 2 or more.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Minoru Wada 2-3-6 Nakanoshima, Kita-ku, Osaka-shi, Osaka Daiken Kogyo Co., Ltd. (56) References JP-A-56-96996 (JP, A) JP-A JP-A-57-71498 (JP, A) JP-A-58-144198 (JP, A) JP-A-1-225684 (JP, A)

Claims (2)

(57) [Claims] A melting point of 70 to 90 with respect to 100 parts by weight of a wood fiber.
Powdered phenolic resin with particle size 200 mesh passing at 10 ~ 4
0 parts by weight and a powdery petroleum resin 5-20 having a melting point of 100-120 ° C. and a particle size of 48 mesh and not passing through 200 mesh.
Part by weight and is a base plate for building made of wood fiber obtained by wet paper milling is mixed, the entangled portion of the wood fiber is adhered by melting and fixing of the phenolic resin and petroleum resin, the specific gravity is 0.35 to 0.4, A wood fiber architectural base plate having a thickness of 10 to 15 mm and a strength of a wall magnification of 2 or more. 2. 100 parts by weight of wood fiber, 10 to 40 parts by weight of a powdered phenol resin having a melting point of 70 to 90 ° C. and a particle size of 200 mesh, and a phenol resin having a melting point of 100 to 120 ° C. and a particle size of 48 mesh. And a slurry formed by mixing and stirring 5 to 20 parts by weight of solid petroleum resin that does not pass through 200 mesh in water is wet-processed, and the wet mat after forming is gradually heated until its internal temperature reaches a temperature of 100 to 120 ° C. A method for producing a wood fiber architectural base plate, comprising heating and drying at a temperature not lower than the curing point of the powdered phenol resin after raising the temperature.