JP2014097597A - Stacked body for reinforcement material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement material which suppresses dimensional change of a foamed body, and can have both of bending strength and machinability compared with a conventional plywood board which is used as a reinforcement material that is used so as to come in contact with a foamed body.SOLUTION: A stacked body 5 comprises: a core layer 3; barrier layers 1a and 1b arranged on both surfaces of the core layer 3; and intermediate layers 2a and 2b arranged between the core layer 3 and the barrier layers 1a and 1b respectively. The core layer 3 has a density of 0.30 g/cmor more and 0.80 g/cmor less, and a thickness of 0.50 mm or more and 2.00 mm or less. The barrier layers 1a and 1b have a moisture vapor transmission rate of 5.0 g/m24 h or less. The intermediate layers 2a and 2b have a density of 0.80 g/cmor more, a Young's modulus in at least one direction out of a MD vertical direction and a parallel direction of 2,800 MPa or more, an average Young's modulus of the MD vertical direction and the MD parallel direction of 4,000 MPa or more, and a moisture vapor transmission rate of 10.0 g/m24 h or less. The whole of the stacked body 5 has a moisture vapor transmission rate of 2.0 g/m24 h or less and a thickness of 1.15 mm or more.

Description

  The present invention relates to a laminate for a reinforcing material, and mainly relates to a reinforcing material using the same and protecting a resin foam used for a building material or the like.

  Resin foams are excellent in heat insulation, light weight, cushioning properties, and easy to process, so olefin-based and styrene-based resin foams such as polypropylene are used for house wall materials, flooring materials, and ceiling materials. It is used as a building material. However, while the resin foam has the above-mentioned advantages, it has a defect that its surface is easily deformed due to impact because of its low density, and the heat insulating property is lowered or a gap is generated at the deformed portion. For this reason, it is often used in combination with a reinforcing material for protecting the surface of the resin foam. As this reinforcing material, inexpensive plywood (plywood), wood fiber board, plastic board, cardboard, etc. are used.

  For example, in Patent Documents 1 to 3, wall materials, floor materials, and ceiling materials that use plywood as a reinforcing material for resin foam are used. In Patent Document 4, load distribution and deformation are prevented by placing a plywood on top of the foam. Patent Documents 5 to 7 exemplify veneer boards, synthetic resin sheet materials, paper, plastic corrugated board, and the like as the reinforcing material for the resin foam in Patent Documents 5 to 7.

JP 05-098769 A Japanese Patent Laid-Open No. 08-284276 JP 2000-179129 A Japanese Utility Model Laid-Open No. 06-061164 JP 09-256607 A Japanese Patent Application Laid-Open No. 07-20785 JP 07-009599 A

  However, when a plastic plate is used as the reinforcing material, even if sufficient strength is obtained, the coefficient of thermal expansion is large and the density is high, so the dimensional change due to temperature difference is large, and it is difficult to maintain the dimensional accuracy. There was a case. In the case of cardboard, the dimensional change due to the humidity difference is large and practical use is difficult, and there is a problem that the thickness is increased and the weight is increased to obtain sufficient strength. When plywood is used, it is sufficient if the dimensional accuracy is relatively high and the strength is constant. However, if a certain level of thickness is secured, the problem is that the workability and punchability are poor due to the rigidity. was there.

  In addition, resin foams such as polyolefin foam and polystyrene foam are often used as building materials such as heat insulating materials and core materials for flooring, but the reinforcing materials used in combination are in an environment that is susceptible to seasonal changes in humidity and temperature. Expansion and contraction are likely to occur due to this environmental change, and if it is left as it is, a dimensional change will occur depending on the difference in humidity and temperature between summer and winter. If such expansion and contraction is left as it is, a gap is generated on the wall surface or floor surface of the building. This expansion and contraction width can be reduced by bonding or sewing the resin foam and the reinforcing material, but the resin foam also expands and contracts with changes in temperature and humidity, so the dimensional change per building material 910 mm x 1820 mm It was difficult to suppress it to less than 4.0 mm.

  Accordingly, an object of the present invention is to provide a reinforcing material having a high bending strength and a small dimensional change for reinforcing a resin foam or the like.

This invention
A core layer, a barrier layer on both surfaces, and a laminate having an intermediate layer between the core layer and the barrier layer,
The core layer is made of a material having a density of 0.30 g / cm ^{3 to} 0.80 g / cm ³ and a thickness of 0.50 mm to 2.00 mm.
The barrier layer has a moisture permeability of 5.0 g / m ² · 24 h or less,
The intermediate layer has a density of 0.80 g / cm ³ or more and a moisture permeability of 10.0 g / m ² · 24 h or less. When the intermediate layer has directionality at the time of manufacture, its MD (Machine Direction) ) Either of the Young's modulus when bent perpendicularly or parallel to the direction is 2800 MPa or more, and the average Young's modulus in the MD vertical direction and MD parallel direction is 4000 MPa or more. Sometimes when there is no directionality, the Young's modulus in the weakest direction is 2800 MPa or more, and the average Young's modulus in the weakest direction and the direction perpendicular thereto is 4000 MPa or more,
If the moisture permeability of the entire laminate is 2.0 g / m ² · 24 h or less, the thickness is 1.15 mm or more, and if the intermediate layer has directionality, it is bent perpendicularly or parallel to the MD direction. The weakest direction when the Young's modulus of either one is 2500 MPa or more and the average of the Young's modulus in the MD vertical direction and MD parallel direction is 3800 MPa or more, and the intermediate layer does not have directionality during its production. The above problems were solved by a laminate having a Young's modulus of 2500 MPa and an average of Young's modulus in the weakest direction and a direction perpendicular thereto being 3800 MPa or more.

  That is, the laminate according to the present invention has at least five layers of a barrier layer, an intermediate layer, a core layer, an intermediate layer, and a barrier layer. By making a composite structure in which each of these layers optimally bears the required role, the required properties can be exhibited. However, each layer does not need to be a uniform layer, and each of the above layers may be composed of a plurality of layers.

  The division of roles is as follows. The core layer made of a low-density material can ensure bulkiness and sufficiently increase rigidity. As will be described later, since the rigidity is proportional to the cube of the thickness, it is very important to be bulky in terms of strength. In addition, a low-density material has a smaller dimensional change than a high-density material, and a low stress accompanying the dimensional change contributes to a reduction in the dimensional change of the laminate. At the same time, the core layer can be reduced in weight because of its low density, and the machinability can be improved because the core layer is used as the main layer. However, the core layer alone has a low Young's modulus and insufficient bending strength as a reinforcing material. On the other hand, the intermediate layer disposed above and below the core layer has a higher density than the core layer and has a necessary strength, prevents direct deformation of the core layer, and exhibits a bending strength necessary as a reinforcing material. Only the configuration of the high-density intermediate layer is heavy, and there is a problem in cutting workability. However, by having a low-density core layer in between, weight reduction and cutting workability can be ensured as a whole. For this purpose, each intermediate layer is desirably thinner than the core layer, and the optimum value depends on the thickness of the core layer, but the thickness of the intermediate layer is preferably 0.20 mm or more and 0.90 mm or less. Further, the barrier layer and the intermediate layer on the surface doubly suppress the intrusion of humidity, and the influence on the dimensional change due to the humidity of the intermediate layer made of a high-density material can be minimized.

  The barrier layer is basically easily realized by using a plastic film having a water vapor barrier property. In order to ensure low moisture permeability, it is more preferable to provide a moisture barrier layer on the plastic film by coating or vapor deposition. Here, as a material of the plastic film, it is preferable to use a resin having a softening point higher than that of polyethylene, such as polyester such as polyethylene terephthalate and polypropylene, which is easy to use for joining the layers.

  For the core layer, a low-density material is preferable, but for example, by using a paper-based material mainly containing cellulose, by achieving the above-mentioned bulky thickness, the strength can be reduced without reducing the machinability. It is possible to have a thickness necessary for ensuring the above.

  The said intermediate | middle layer is easy to implement | achieve said physical property as it is a component containing resin. Specifically, the use of laminated paper that is a composite sheet of resin and paper makes it easy to achieve the above strength and density. That is, the intermediate layer is denser and stronger than the core layer, but the thickness of the intermediate layer is reduced accordingly. If it is thicker than the core layer, a problem is likely to occur in the machinability, so that the layers can be laminated within a thickness range below that. However, the number of laminated papers is not limited to one, and a plurality of laminated papers may be stacked to form one intermediate layer.

  The intermediate layer may or may not have directionality at the time of manufacture, but if both are in the above range with respect to the value of the weakest direction and the average of the direction perpendicular thereto, it is fundamental. Strength can be secured. In addition, when it has directionality, the Young's modulus of MD parallel direction becomes a lower value in many cases. And the whole laminated body concerning this invention can mainly implement | achieve the presence or absence of directionality of this intermediate | middle layer, and the high Young's modulus along the direction.

  These layers are preferably laminated and bonded by heat fusion using a thermoplastic resin. When a laminated paper is used for the intermediate layer, it can be bonded by melting the polyolefin used for the lamination, so there is no need to dare to sandwich another adhesive layer.

  The laminated body according to the present invention has either Young's modulus when bent in the direction perpendicular or parallel to the MD direction at the time of manufacturing the intermediate layer, or the weakest Young's modulus when the intermediate layer has no directionality. Is an average of Young's moduli in the MD vertical direction and MD parallel direction, or when the intermediate layer has no directionality, an average of Young's moduli in the weakest direction and the direction perpendicular thereto is 3800 MPa or more. In any case, as a reinforcing material that is sufficiently strong against bending pressure and has better dimensional stability than plastic board, cardboard, and veneer board, it is used for building materials such as wall materials and floor materials used in combination with resin foam. be able to.

Sectional drawing which shows the example of embodiment of the laminated body concerning this invention Sectional drawing which shows the example of embodiment which an intermediate | middle layer consists of a some sheet | seat

  The present invention will be described in detail below. The present invention is a laminate having bending strength, cutting workability and dimensional stability, which can be used mainly as a reinforcing material provided to protect a resin foam layer of a building material.

  The laminate according to the present invention is a laminate having a core layer, upper and lower surface barrier layers, and an intermediate layer between the core layer and the barrier layer. That is, as shown in the cross-sectional view of FIG. 1, the laminate 5 has at least five layers of a barrier layer 1a, an intermediate layer 2a, a core layer 3, an intermediate layer 2b, and a barrier layer 1b.

Barrier layer 1a, 1b is a layer less moisture permeability of 5.0g ^/ m 2 · 24h, preferably is not more than 3.0g ^/ m 2 · 24h, preferably lower. That is, it is a layer that exhibits the water vapor barrier property and most suppresses the intrusion of moisture into the inside. Basically, it may be arranged on the upper and lower surfaces of the laminate 5. Specific examples of the structure include a plastic film, or a film coated or deposited thereon. As the plastic, it is preferable to use, for example, a polymer having a softening point higher than that of polyethylene or the like and difficult to soften, such as polyethylene terephthalate or polypropylene. The thickness of the film is preferably 100 μm or less, and more preferably 60 μm or less. This is because if the thickness is too large, the force at the time of dimensional change due to temperature change increases, and there is a possibility that the balance of each layer may not be achieved. On the other hand, if it is too thin, it will be easily broken, so it is necessary to have some strength. The plastic film substrate is preferably thicker in order to improve moisture resistance and protect the coating or vapor deposition layer, preferably 8 μm or more, and more preferably 10 μm or more. An aluminum foil base material can also be used from the viewpoint of moisture resistance, but it is difficult to handle when it is thinned from the limit of rolling, and a plastic film base material is preferable from the viewpoint of weight reduction, resource saving, energy saving, and cost.

Examples of the content of the coating include those obtained by vapor-depositing aluminum, silica, and alumina, those obtained by coating polyvinylidene chloride (PVDC) and nanocomposite, and the like, and may improve the water vapor barrier property.
As processing for improving the water vapor barrier property of the plastic film substrate, metal deposition such as PVDC coating and aluminum is preferable, and aluminum deposition is more preferable in consideration of the problem of dioxins during incineration. On the other hand, silica, alumina vapor deposition and the like are glassy, so they are vulnerable to bending, and defects may occur due to impacts during processing, physical distribution, actual use, etc., and the barrier property may be lowered.
In addition, when using the film by which these coating and vapor deposition were used, in order to protect the processed moisture-proof layer, the film base material faces the surface side of the laminated body 5, and the surface coated or vapor-deposited on the intermediate layer 2a, 2b side It is good to arrange it to face.

The core layer 3 is made of a material having a density of 0.30 gcm ³ or more and 0.80 g / cm ³ or less, preferably 0.35 g / cm ³ or more and 0.70 g / cm ³ or less. As such a material, for example, 50% by mass or more is a paper-based material obtained by processing paper-derived raw materials derived from cellulose such as pulp, waste paper, and cotton, or a resin fiber such as polyester. A fiber laminate such as a non-woven fabric can be suitably used because it is relatively lightweight. However, wood itself does not enter. Although depending on the type of wood, if the core layer 3 is wood, there is a high risk of problems in the machinability of the resulting laminate. Moreover, said paper-type material and fiber laminated body may contain additives, such as a paper strength enhancer, a wet paper strength agent, a binder component, and a size agent, as needed. A density as described above of 0.30 g / cm ³ or more and 0.80 g / cm ³ or less is a material having a relatively low density and is excellent in dimensional stability and machinability. In the case of a material having a density lower than 0.30 g / cm ^3, the Young's modulus of the laminate 5 is lowered, which may cause a problem in terms of strength. It is more preferable that it is 0.35 g / cm ³ or more from the viewpoint of securing the strength. On the other hand, if the core layer that secures a predetermined thickness is higher than 0.80 g / cm ³ , the dimensional change of the core layer alone is large, and the stress accompanying the dimensional change is also large, resulting in the laminate being Dimensional change increases. 0.80 g / cm ³ or less is more preferable from the viewpoint of dimensional change and processing, and 0.70 g / cm ³ or less is more preferable.

  Further, if the thickness of the core layer 3 is less than 0.50 mm, the strength of the entire laminated body 5 is insufficient, and it is easy to bend and becomes insufficient as a reinforcing material, so it is necessary to be 0.50 mm or more. , 0.60 mm or more is preferable. This is because the strength of the material alone is not sufficient to ensure the rigidity of the entire laminate necessary as a reinforcing material, and a certain bulkiness is required. Specifically, the rigidity is indicated by the product of the cube of the thickness and the Young's modulus. The thicker the rigidity, the higher the rigidity. Therefore, the thicker the core layer 3, the better. The thicker the thickness, the easier it is to secure the rigidity. On the other hand, if the core layer 3 with a low density exceeds 2.00 mm, the Young's modulus of the entire laminate 5 is reduced. In order to maintain a high Young's modulus, it is more preferable that it is 1.50 mm or less.

The intermediate layers 2a and 2b have a density of 0.80 g / cm ³ or more. That is, the material is denser than the core layer 3. This is because the strength is insufficient at low density, and the strength contribution effect combined with the core layer 3 is not sufficiently exhibited. Although it depends on the material, it is more preferably 1.00 g / cm ³ or more.

Further, the moisture permeability of the intermediate layers 2a and 2b needs to be 10.0 g / m ² · 24 h or less, preferably 8.0 g / m ² · 24 h or less, and the lower the better. It is difficult to completely prevent water vapor from entering the barrier layers 1a and 1b alone, and the intermediate layers 2a and 2b also have some water vapor barrier properties in order to increase the moisture permeability resistance of the entire laminate 5 and to minimize dimensional changes. It is because it is required to exhibit.

  Furthermore, the intermediate layers 2a and 2b need to exhibit sufficient bending strength. In order to realize the physical properties of the intermediate layers 2a and 2b, when the intermediate layer has directionality at the time of manufacture, it is perpendicular to the MD (Machine Direction) direction (that is, TD: Transverse Direction) or parallel (that is, One of the Young's moduli when bent to MD itself) needs to be 2800 MPa or more, and preferably 3000 MPa or more. Moreover, the average of the Young's modulus of MD perpendicular direction and MD parallel direction needs to be 4000 Mpa or more, and it is preferable in it being 4500 Mpa or more. On the other hand, when this intermediate layer does not have directionality during its production, the Young's modulus in the weakest direction needs to be 2800 MPa or more, and preferably 3000 MPa or more. The average Young's modulus between the weakest direction and the direction perpendicular to the weakest direction needs to be 4000 MPa or more, and is preferably 4500 MPa or more. That is, the Young's modulus is at least 2800 MPa regardless of the direction, and the average bending strength of 4000 MPa or more can exhibit the required bending strength for the laminate.

  As the sheet used for the intermediate layers 2a and 2b, specifically, a processed paper laminated with a polyolefin such as polyethylene or a resin-impregnated paper can be used. In particular, when polyethylene-laminated paper is used, adhesion to the barrier layers 1a and 1b and the core layer 3 can be performed simply by thermally melting the intermediate layers 2a and 2b.

  The intermediate layers 2a and 2b may have a laminated structure in which a plurality of such sheets are stacked. Further, the intermediate layer 2a and the intermediate layer 2b may have different thicknesses. That is, using the same sheet, the number of sheets may be different between the intermediate layer 2a and the intermediate layer 2b, or the thickness of the sheet itself may be different. However, when the number of sheets is adjusted using the same sheet, it is easy to adjust the required physical properties and to manufacture easily. For example, FIG. 2 shows a cross-sectional view of an embodiment in which the intermediate layers 2a and 2b are obtained by laminating the laminate sheets 4 (assumed to be a laminated body 5a). In the figure, each intermediate layer 2a, 2b is composed of two laminate sheets 4, but the number of sheets is not limited to this, and the number of sheets may be different from each other.

  However, if each of the intermediate layers 2 a and 2 b is thicker than the core layer 3, the machinability tends to be deteriorated as a tendency. Specifically, when the intermediate layer is 0.90 mm or less, there is almost no problem in cutting workability, and it is preferable that the intermediate layer is 0.70 mm or less. On the other hand, if the thickness is too thin, the bending strength tends to be insufficient, and even if the above Young's modulus is achieved, the laminate 5 as a whole may have insufficient strength. More preferably, it is 0.30 mm or more. However, even if out of the range of these thicknesses, there is a case where there is no problem in the balance of the structure as long as it is thinner than the core layer 3.

  In addition to the above layers, the laminate 5 may have other layers as long as the achievement of necessary physical properties to be described later is not hindered. For example, when a thermoplastic resin is not used for the intermediate layer 2, an adhesive layer made of a thermoplastic resin or the like for bonding the layers may be provided.

  The method for integrating the group of layers as one laminate 5 is not particularly limited as long as it can be integrated with sufficient strength, and examples thereof include a method of bonding with a thermoplastic resin. Specifically, after a film used for the barrier layer 1, a laminated paper used for the intermediate layer 2, a low density paper used for the core layer 3, and the like, the thermoplastic resin such as polyethylene contained therein is melted. The whole is heated to the temperature and integrated. As a heating method, a method of hot pressing a group of sheets once prepared, a method of heating a continuous sheet to bring a thermoplastic resin layer into a molten state and applying pressure with a roller, a thermoplastic resin such as polyethylene Examples thereof include a method of integrating by extrusion lamination, a method of using an adhesive, and the like.

  The laminate 5 according to the present invention needs to have a Young's modulus of at least 2500 MPa as a minimum bending strength. When said intermediate | middle layer, a core layer, etc. have directionality at the time of manufacture, either one when bent perpendicularly or parallel with respect to MD direction at the time of intermediate | middle layer and core layer manufacture is 2500 Mpa or more. This value is a value that should be achieved at least in the direction in which the Young's modulus decreases due to the fiber orientation and shrinkage of the base material such as the intermediate layer and the core layer, and is more preferably 3000 MPa or more. Moreover, the average of the Young's modulus of MD perpendicular direction and MD parallel direction needs to be 3800 MPa or more, and it is preferable in it being 4500 MPa or more. On the other hand, even if it is produced by a method with no directionality or little difference depending on the direction, the Young's modulus in the weakest direction among them needs to be 2500 MPa or more, and preferably 3000 MPa or more. And when there is no such directionality, the average Young's modulus of the weakest direction and the direction perpendicular | vertical to it needs to be 3800 MPa or more, and it is preferable in it being 4500 MPa or more.

  However, when the Young's modulus of the laminated body 5 is too high, the strength is too high, which may impair the machinability. If there is a direction in which the Young's modulus exceeds 9000 MPa in any one direction, easy cutting by hand tends to be difficult. In addition, the measuring method of Young's modulus prescribed | regulated here was performed based on JISA5905.

Moreover, the laminated body 5 concerning this invention needs to have a moisture permeability of 2.0 g / m ² · 24 h or less as a whole, more preferably 1.7 g / m ² · 24 h or less, and the lower the better. . If too much moisture is passed as a whole, the amount of moisture that penetrates into the laminate 5 increases, and the dimensional stability deteriorates. There is also a concern about an increase in the amount of moisture that has permeated through the laminate to the resin foam.

  Furthermore, the laminated body 5 concerning this invention needs to be excellent in dimensional stability as a reinforcing material. That is, it is necessary to be able to suppress the dimensional change that occurs according to the temperature and humidity change of the resin foam used for the building material to such an extent that no practical problem occurs when used as the building material. The laminate 5 according to the present invention and the resin foam are integrated by bonding with an adhesive or sewing with a thread. Specifically, the allowable dimensional change of the laminate 5 is that when a sample of 900 mm square is placed in an environment of 23 ° C. and 50% RH in an environment of 25 ° C. and 90% RH for 7 days, the sample is parallel to MD. Measure the dimensions in the direction and MD perpendicular direction (if there is no directionality, measure the dimensions in any direction), then measure the dimensions in both directions after being placed in an environment of 25 ° C and 30% RH for 7 days. And the difference in size is 2.0 mm or less, preferably 1.7 mm or less, and more preferably 1.5 mm or less. The dimensional stability is relatively good, and the general dimensional change of the veneer plate that has been used as a reinforcing material in the past is about 1.7 mm under the same conditions. The laminate 5 according to the present invention has a composite structure of the above layers. Therefore, dimensional stability superior to the plywood can be realized.

  A material that can be reinforced by the laminate 5 according to the present invention is preferably brought into contact with a resin foam used as a building material and integrated by adhesion or sewing, because defects of the resin foam lacking in strength and rigidity can be reinforced. Examples of such resin foams include polystyrene foam, polyolefin foams such as polyethylene and polypropylene, and thermosetting resin foams such as hard polyurethane, soft polyurethane, phenol resin, urea resin, epoxy resin, and acrylic resin. , Ebonite foam, polyvinyl chloride foam and the like.

An embodiment in which the present invention is implemented will be specifically described.
First, materials used for each layer will be described.

<Barrier layer>
Aluminum deposited polyethylene terephthalate film: thickness of 12 [mu] m, moisture permeability ^{2.9g / m 2 · 24h (.} TORAY ADVANCED MATERIALS KOREA INC EXCELL VM-PET1310).
Polyvinylidene chloride-coated biaxially stretched polypropylene film: thickness 30 μm, moisture permeability 5.0 g / m ² · 24 h (Dencel Value Coating Co., Ltd., Senec 1000). Expressed as “PVDC-OPP”.
Polyethylene film: thickness 40 μm, moisture permeability 13.0 g / m ² · 24 h. Hereinafter referred to as “PE40μ”.
<Intermediate layer>
Resin-laminated paper: A processed paper having a thickness of 0.23 mm obtained by laminating a 30 μm-thick polyethylene layer on both sides of a high-quality water-resistant paper having a basis weight of 170 g / m ² . Basis weight 236 g / m ² . Density 1.05 g / cm ³ . Moisture permeability 7.7g / m ² · 24h. Young's modulus MD vertical direction 7352 MPa, MD parallel direction 3228 MPa. Hereinafter referred to as “SP”.
Laminated coated ball: A processed paper obtained by laminating a 20 μm thick polyethylene layer on both sides of a coated ball (CRN, Rengo Co., Ltd., basis weight 400 g / m ² , thickness 0.51 mm). Density 0.80 g / cm ³ . The water vapor transmission rate is 9.7 g / m ² · 24 h. Young's modulus MD vertical direction 5408 MPa, MD parallel direction 2802 MPa. Hereinafter referred to as “laminated CRC”.
(Polyethylene film: thickness 20 μm, moisture permeability 22 g / m ² · 24 h)
<Core layer or comparative intermediate layer>
Low density paper: “MFS15” manufactured by Marusan Paper Co., Ltd., density 0.35 g / cm ³ , thickness 1.50 mm.
Low density paper: “MF15” manufactured by Marusan Paper Co., Ltd., density 0.40 g / cm ³ , thickness 1.50 mm.
Low density paper: “MF10” manufactured by Marusan Paper Co., Ltd., density 0.41 g / cm ³ , thickness 1.00 mm.
Low density paper: “MF07” manufactured by Marusan Paper Co., Ltd., density 0.45 g / cm ³ , thickness 0.70 mm.
-Paper tube base paper: Rengo Co., Ltd. 5K, density 0.71g / cm < ³ >, thickness 1.00mm. Hereinafter, it is expressed as “paper tube base paper 1 mm”.
Low density paper: “Fwatlite N720150” manufactured by Toyo Fiber Co., Ltd., density 0.20 g / cm ³ , thickness 0.75 mm.
Low density paper: “MFS20” manufactured by Marusan Paper Co., Ltd., density 0.34 g / cm ³ , thickness 2.00 mm.
<Veneer board>
・ Veneer board: Standard plywood, 1 type, thickness 2.35mm

For the laminates according to each of the examples and comparative examples, SP or the like having a polyethylene layer at the interlayer contact portion was hot-pressed from the top and bottom with a hot plate at 102 ° C. for 2 minutes at a pressure of 7 kg / cm ^2. Then, the laminate is manufactured by cold pressing at room temperature for 2 minutes. For those having no interlayer adhesive portion, a polyvinyl acetate adhesive (manufactured by Konishi Co., Ltd .: New CH18) is applied at 30 g / m ² and bonded. In all samples, the length and width dimensions in the production stage are 1000 mm.

Next, a measurement method will be described.
<Moisture permeability measurement method>
The moisture permeability of the material of the barrier layer and the intermediate layer and the entire laminated reinforcing material was measured according to JIS Z 0208 “Method of testing moisture permeability of moisture-proof packaging material (cup method)”.

<Dimensional change measurement method>
When a 900 mm square sample was placed in an environment of 23 ° C. and 50% RH for 7 days in an environment of 25 ° C. and 90% RH, the dimensions of the sample in the MD parallel direction and MD vertical direction were measured. After being placed in a 30% RH environment for 7 days, the dimensions in both directions were measured to determine the maximum change from the standard state. Evaluated when the amount of change is 0.5 mm or less. Evaluated when 0.5 mm is greater than 1.5 mm. Evaluated when 1.5 mm is greater than 2.0 mm. It was set as evaluation x.

<Young's modulus measurement method>
From the core layer and intermediate layer materials and the manufactured laminate, a rectangular sample having an MD parallel direction of 200 mm and an MD vertical direction of 50 mm and a rectangular sample having an MD vertical direction of 200 mm and an MD parallel direction of 50 mm were prepared. Similar to the method for measuring the bending strength of JIS A 5905 “Fiberboard”, the Young's modulus in the proportional range of load and deflection was measured with the span direction and the long side direction of the test piece parallel.

<Thickness measurement>
It was measured according to JIS P 8118 “Paper and paperboard—Method for measuring thickness and density”.

<Cutability evaluation>
Measurement of the dimensional change of the laminate When the sample was cut out to a specified size, the laminate was evaluated by the degree of force required when the laminate was cut with a cutter knife (manufactured by NT Corporation, L-500). Evaluated when the force required at the time of cutting was slight ○, evaluated when the force required was slightly less than at the time of cutting the plywood board △, and evaluated as × when the force required to cut the plywood board was required .

  Next, each example and comparative example will be described. Table 1 shows the physical properties of the layers constituting each laminate and the measured data.

(Examples 1-8)
In Examples 1 to 8, VM-PET was used as the barrier layers on the upper and lower surfaces of the laminate, and the core layer was changed to MFS15, which is low density paper, and MF07, 10, 15 and paper tube base paper 1 mm as shown in the table. And the laminated body which changed the number of SP as a table | surface as an intermediate | middle layer was manufactured, respectively. Density of the core layer is improved in Young's modulus of the laminate as the density is increased in a range of ^{0.30g / cm 3 ~0.80g / cm 3} . In addition, as the number of SPs used in the intermediate layer increased, that is, as the layer thickness increased, the Young's modulus improved, the moisture permeability of the intermediate layer decreased, and the dimensional change became smaller.

(Examples 9 to 10)
In Example 9 in which VM-PET as a barrier layer in Example 4 was changed to PVDC-OPP, the laminate had a high Young's modulus and a small dimensional change. In Example 2, in which the intermediate layer of SP · 3 was changed to “laminate CRC”, the moisture permeability was slightly high, but the Young's modulus was high, the dimensional change was kept low, and the laminate was good. Met.

(Comparative Examples 1-2)
In Example 1, the core layer MFS15 was changed to Watlite N720150, and the density of the core layer was reduced to 0.20 g / cm ^3. Comparative Example 1 and the core layer MFS15 of Example 1 were changed to MFS20. In Comparative Example 2 where the thickness of the core layer is 0.34 g / cm ³ , which is about the same as that of Example 1, but the thickness is 2.00 mm, the dimensional change is small, but the Young's modulus is low. Therefore, there was a problem that the strength was insufficient.

<When the intermediate layer has a low density>
(Comparative Examples 3 and 4)
In Example 4, a comparative example 3 was examined in which the arrangement of SP · 3 for the intermediate layer and MF07 for the core layer were interchanged, and the intermediate layer was MF07 and the core layer was SP · 3. Further, in Example 5, Comparative Example 4 was examined in which the three SPs of the intermediate layer were changed to MFS 15 having a density of 0.35 g / cm ³ . In either case, the Young's modulus of the intermediate layer is low, so the effect of reinforcing the core layer is not sufficient, and the Young's modulus of the entire laminate is extremely low. Moreover, since the moisture permeability of MF07 and MFS15 is high, there has been a problem that the dimensional change becomes large.

<When there is no barrier layer on both sides>
(Comparative Examples 5 to 8)
In Examples 2 to 5, when Comparative Examples 5 to 8 in which VM-PET that is a double-sided barrier layer was not provided were examined, humidity transmission could not be sufficiently suppressed because there was no barrier layer, and dimensional change was observed. The amount increased greatly and became worse than the plywood.

<When there is no single-sided barrier layer>
(Comparative Examples 9 and 10)
In Examples 8 and 9, when Comparative Examples 9 and 10 in which VM-PET as a barrier layer was not provided on one side were examined, the amount of dimensional change was worse than that of the veneer board. This is because moisture permeation cannot be sufficiently suppressed on the surface without the barrier layer, and the dimensional change amount is increased. It is considered that the expansion and contraction of the reinforcing material could not be suppressed even when the barrier layer was provided only on one side.

<When the moisture permeability of the barrier layer is high>
(Comparative Example 11)
In Example 4, when Comparative Example 11 in which the VM-PET of the barrier layer was changed to PE 40 μ with a slightly high moisture permeability was examined, although the Young's modulus of the laminate was high, the dimensional change amount was slightly larger than the veneer plate. It was. The moisture permeability of the barrier layer was slightly high, and moisture permeation could not be sufficiently suppressed.

<When no intermediate layer is provided>
(Comparative Example 12)
In Example 5, when Comparative Example 12 in which no SP of three intermediate layers was provided was examined, the Young's modulus of the laminate was slightly insufficient, and since there was no intermediate layer, moisture transmission was suppressed by the intermediate layer. There was no dimensional change.

<In case of intermediate layer only>
(Comparative Example 13)
In Example 6, when Comparative Example 13 in which only four SPs were stacked and joined without providing the core layer MF07 and without providing the barrier layer VM-PET, the Young's modulus of the laminate was secured. However, the amount of dimensional stability has increased. Further, the warpage of the laminate was larger than that of Example 6.

<When the intermediate layer has low density and moisture permeability>
(Comparative Example 14)
In Example 1, a comparative example 14 in which the SP of the intermediate layer was changed to 1 mm of the paper tube base paper was examined, and the Young's modulus was lower because the density of the paper tube base paper 1 mm was lower than that of the SP. The effect of reinforcing the core layer as a layer was low. For this reason, the Young's modulus of the laminate was also lowered. In addition, the paper tube base paper 1 mm has a higher moisture permeability than SP, which causes a problem in dimensional stability.

<When the intermediate layer is strong and causes a problem in cutting workability>
(Comparative Examples 15 and 16)
In Example 4, Comparative Examples 15 and 16 in which the number of SP · 3 intermediate layers was increased to SP · 4 and SP · 5 were examined. When the number of SPs is continuously 4 or more, the Young's modulus of the laminate becomes very high, the dimensional change becomes smaller, the physical properties of the laminate are high, but the machinability is remarkably inferior. Yes, practicality was low.

(Reference Example 1)
A supplementary study was conducted on plywood that has been used as a reinforcing material. The veneer plate has a large Young's modulus anisotropy and a low Young's modulus in the MD parallel direction, so that it has a problem that it is vulnerable to impact from a certain direction. On the other hand, since the Young's modulus in the MD vertical direction is too high, there is a problem that the machinability is remarkably inferior.

(Heat shrinkage with plastic material)
When a 900 mm square sample was changed in temperature from 25 ° C. and 30% RH (7 days) to 5 ° C. and 30% RH (7 days), the plywood (Reference Example 1) and the present example (Example 4 In Example 6), there was no dimensional change, whereas in Pradan A and B made of polypropylene, there was expansion and contraction due to temperature change, and it was confirmed that it was inappropriate as a reinforcing material for building materials and the like. The results are shown in Table 2.

1, 1a, 1b Barrier layer 2, 2a, 2b Intermediate layer 3 Core layer 4 Laminate sheet 5, 5a Laminate

Claims (5)

A core layer, a barrier layer on both surfaces, and a laminate having an intermediate layer between the core layer and the barrier layer,
The core layer is made of a material having a density of 0.30 g / cm ^{3 to} 0.80 g / cm ³ and a thickness of 0.50 mm to 2.00 mm.
The barrier layer has a moisture permeability of 5.0 g / m ² · 24 h or less,
The intermediate layer has a density of 0.80 g / cm ³ or more and a moisture permeability of 10.0 g / m ² · 24 h or less. When the intermediate layer has directionality at the time of manufacture, its MD (Machine Direction) ) Either of the Young's modulus when bent perpendicularly or parallel to the direction is 2800 MPa or more, and the average Young's modulus in the MD vertical direction and MD parallel direction is 4000 MPa or more. When there is no directionality, the Young's modulus in the weakest direction is 2800 MPa or more, and the average Young's modulus in the weakest direction and the direction perpendicular thereto is 4000 MPa or more,
If the moisture permeability of the entire laminate is 2.0 g / m ² · 24 h or less, the thickness is 1.15 mm or more, and the intermediate layer has directionality, it is bent perpendicularly or parallel to the MD direction. The weakest direction when the Young's modulus of either one is 2500 MPa or more and the average of the Young's modulus in the MD vertical direction and MD parallel direction is 3800 MPa or more, and the intermediate layer does not have directionality during its production. A laminate in which the Young's modulus is 2500 MPa and the average Young's modulus in the weakest direction and the direction perpendicular thereto is 3800 MPa or more.   The laminate according to claim 1, wherein the core layer is a paper-based material.   The laminate according to claim 1 or 2, wherein the intermediate layer is formed by laminating and bonding one or more laminated papers.   The laminate according to claim 3, wherein the intermediate layer is formed by laminating and bonding two or more laminated papers.   The said barrier layer consists of a plastic film which gave the polyvinylidene chloride coating or aluminum vapor deposition process on the single side | surface, and has distribute | arranged the surface which has not been coated or vapor-deposited toward the outer side. The laminated body as described in.

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