JP2002327531A - Plastic composite panel and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic composite panel used at a concrete construction site of construction work and civil engineering work, lightweight with excellent flexural rigidity, excellent surface smoothness of concrete after placing concrete and also excellent recyclability after use. SOLUTION: This plastic composite panel using plastic as a main material has a main layer 1, an outer layer 2 formed on the outside of the main layer 1, and a skin layer 3 formed on the outside of the outer layer 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic composite panel and a method of manufacturing the same, and more particularly to a lightweight, excellent flexural rigidity and concrete after casting concrete used in a concrete construction site for construction or civil engineering. The present invention relates to a plastic composite panel excellent in surface smoothness of concrete and excellent in recyclability after use, and a method for producing the same.

[0002]

2. Description of the Related Art Inexpensive and excellent workability, plywood made of South Sea wood has been widely used for panels for concrete formwork. However, wood plywood panels have recently become problematic as global warming has become a major issue worldwide due to concerns about a decline in carbon dioxide absorption capacity due to depletion of forest resources due to over-cutting, and carbon dioxide emissions due to incineration after use. There is a strong demand for the development and spread of alternative materials.

[0003] In response to such demands, many alternative materials have been proposed. For example, metal formwork made of steel or aluminum has excellent rigidity and impact resistance, and is partially used in special fields where these characteristics are required. Has not been reached.

[0004] The following panels are known as panels made mainly of plastic which are promising in terms of lightness.

Japanese Patent Application Laid-Open No. 9-228632 discloses a plastic composite panel for concrete formwork in which a skin layer and an intermediate foam layer are formed by applying pressure. Hereinafter, this is referred to as Conventional Technology 1.

Japanese Patent Application Laid-Open No. Hei 8-100523 discloses a highly foamed layer having a density of 1 to 10 kg / m ³ and a density of 20 to 5 kg / m ^3.
A plastic composite panel for concrete formwork comprising two layers of low or unfoamed layers of 0 kg / m ³ is disclosed. Hereinafter, this is referred to as Conventional Technique 2.

[0007] Japanese Patent Application Laid-Open No. 7-124947 discloses a molded article composed of waste thermosetting plastic and waste polystyrene. Hereinafter, this is referred to as conventional technology 3.

[0008]

However, the above-mentioned plastic-based alternative materials have the following problems, do not satisfy the required performance required for concrete formwork panels, and have not been widely used. .

In the prior art 1, the original foamed structure is inevitably left when the surface is quenched or compressed only during the production of the foam molded article, so that the surface is inferior in smoothness. Moreover,
Since the foaming rate changes discontinuously from the intermediate foam layer to the skin layer, the skin layer is easily peeled off during actual use.

In the prior art 2, when the surface layer is an unfoamed layer, the surface properties are not inferior, but since the foaming ratio of the high foamed layer is too high, the panel as a panel for a formwork having bending strength, nailing property, etc. Poor basic performance. In addition, since the foaming ratio changes discontinuously from the high foaming layer to the low foaming layer or the non-foaming layer, the surface layer of the low foaming layer or the non-foaming layer is easily peeled off during actual use.

The prior art 3 aims at recycling used plastics, which is very significant from the viewpoint of environmental and resource issues. However, thermosetting used plastics and waste polystyrene are used as industrial wastes. However, there is a problem that it is difficult to achieve weight reduction.

Although some other examples of methods using a recycled resin have been proposed, industrial wastes which are easy to recycle are mostly used because the components and properties are relatively constant and the amount of impurities is small. The main source of used plastic discharged from general households, for example, used plastic separated and collected under the Containers and Packaging Recycling Law, is that its components and properties are unstable, and metals and paper other than plastic At present, it has not yet been realized because of the inclusion of impurities.

As can be seen from the above examples, plastic formwork panels are not only insufficient in performance, but also
In terms of price, it has not been able to replace wood plywood panels as a result of competing with existing wood plywood forms. In particular, formwork panels made from used plastics that are discharged as general waste are very promising technologies from the viewpoint of global environmental protection, but no promising technologies have been proposed so far. It is.

Accordingly, an object of the present invention is to provide a truly wood plywood which satisfies the required bending rigidity and lightness, and is excellent in nailing, sawing and surface properties, and furthermore economical. A plastic composite panel and a plastic composite panel capable of obtaining a new plastic composite panel that can replace a panel as a main raw material from used plastic, particularly used plastic discharged from general households covered by the Containers and Packaging Recycling Law. It is to provide a manufacturing method.

[0015]

Means for Solving the Problems As the first invention of the present invention,
The invention according to claim 1 is a plastic composite panel mainly made of plastic, comprising a central layer, an outer layer formed outside the central layer, and a skin layer formed outside the outer layer. It has features.

A second aspect of the present invention is characterized in that the porosity of the outer layer is 10% or less.

According to a second aspect of the present invention, there is provided a plastic composite panel made of plastic as a main material, wherein a central layer, an intermediate layer formed outside the central layer, And a skin layer formed outside the surface layer, wherein the porosity of the center layer is higher than the porosity of the surface layer, and the average porosity of the intermediate layer is the center layer. And the porosity of the intermediate layer is less than or equal to the porosity of the surface layer, and the porosity of the intermediate layer decreases almost continuously from the central layer toward the surface layer.

The invention according to a fourth aspect is characterized in that the porosity of the surface layer is 5% or less.

According to a third aspect of the present invention, there is provided a plastic composite panel made of plastic as a main material, wherein a central layer, an intermediate layer formed outside the central layer, and an intermediate outer layer are provided. Surface layer, an outer layer formed outside the surface layer, and a skin layer formed outside the outer layer, the porosity of the central layer is higher than the porosity of the surface layer, The average porosity of the intermediate layer is equal to or less than the porosity of the central layer, equal to or greater than the porosity of the surface layer,
The porosity of the intermediate layer decreases substantially continuously from the central layer toward the surface layer.

[0020] The invention according to claim 6 is characterized in that the porosity of the surface layer is 5% or less.

According to a seventh aspect of the present invention, the outer layer has a porosity of 10% or less.

[0022] In addition to the first to third aspects of the present invention, an eighth aspect of the present invention is characterized in that the porosity of the central layer is in the range of 20 to 60%.

The invention according to claim 9 is characterized in that the thickness of the skin layer is in the range of 0.2 to 2 mm.

[0024] The invention according to claim 10 is characterized in that it contains wood powder.

An eleventh aspect of the present invention is characterized in that the plastic contains a plastic that has been dechlorinated or dechlorinated.

As a manufacturing method according to the second aspect of the present invention, the twelfth aspect of the present invention is to form a central layer having pores, and then pressurize the surface of the central layer to have a porosity lower than that of the central layer. While forming a surface layer, at the boundary between the center layer and the surface layer, the porosity is substantially continuously from the center layer toward the surface layer from the center layer to the porosity not higher than the porosity of the center layer. Form a reduced intermediate layer, then
The method is characterized in that a skin layer-forming substance is supplied to the outer surface of the surface layer, and the skin layer-forming substance is pressurized while being heated to form a skin layer on the outer surface of the surface layer.

According to a thirteenth aspect of the present invention, a central layer having pores is formed, and then a skin layer-forming substance is supplied onto an outer surface of the central layer. Pressurizing while heating, pressurizing while heating the central layer together with the skin layer forming material, to form a surface layer having a lower porosity than the central layer,
At the boundary between the central layer and the surface layer, an intermediate layer having a porosity less than or equal to the porosity of the central layer and greater than or equal to the porosity of the surface layer, wherein the porosity decreases substantially continuously from the central layer toward the surface layer. And forming a skin layer on the outer surface of the surface layer.

As a manufacturing method according to the third aspect of the present invention, the invention according to claim 14 is to form a center layer having pores, then supply an outer layer forming substance on the outer surface of the center layer, Pressing the central layer while heating the outer layer forming material together with the outer layer forming material to form a surface layer having a lower porosity than the central layer, and at the boundary between the central layer and the surface layer, at a porosity of the central layer or less, More than the porosity of the surface layer, to form an intermediate layer whose porosity is reduced almost continuously from the central layer toward the surface layer, and to form an outer layer on the outer surface of the surface layer, It is characterized in that a skin layer forming substance is supplied to the outer surface of the outer layer, and the skin layer forming substance is pressurized while being heated to form a skin layer on the outer surface of the outer layer.

According to a fifteenth aspect of the present invention, the central layer having pores and the outer layer on the outer surface of the central layer are simultaneously formed by heating, and then the central layer and the outer layer are pressed together to form the outer layer. Forming a surface layer having a lower porosity than the center layer, and at the boundary between the center layer and the surface layer, from the center layer to the surface layer at a porosity of the center layer or less and a porosity of the surface layer or more. To form an intermediate layer having a porosity almost continuously reduced, thereafter supplying a skin layer forming substance to the outer surface of the outer layer, and applying pressure while heating the skin layer forming substance, It is characterized in that a skin layer is formed on the outer surface of the outer layer.

[0030]

Next, an embodiment of the first invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the structure of the plastic composite panel of the present invention.

In FIG. 1, 1 is a central layer, 2 is an outer layer formed outside the central layer 1, 3 is a skin layer formed outside the outer layer 2, 4 is a bubble, and 5 is Wood flour.

The plastic composite panel of the present invention is intended to improve workability as a panel for concrete formwork.
The foam structure is a basic structure for weight reduction. However, when the entire panel is uniformly foamed, there are problems such as workability as a mold, nail pull-out due to a decrease in nail pull-out resistance, occurrence of cracks, and the required bending rigidity as a mold is insufficient. Poor panel surface properties (smoothness).

Therefore, in the present invention, the center layer 1 having little influence on the bending rigidity has a foamed structure, and in order to compensate for a decrease in the bending rigidity of the panel due to the foamed structure, the center layer 1 is formed.
An outer layer 2 was formed on the outside of the panel, and a skin layer 3 was formed on the surface of the outer layer 2 to improve the surface properties of the panel.

The present inventors have further studied to obtain a preferable porosity range of the center layer 1. As a result, the central layer 1
If the porosity exceeds 60%, the nail pulling resistance, bending rigidity and bending strength become insufficient.
It has been found that the specific gravity of the plastic composite panel increases, and the workability as a panel for a concrete formwork becomes inferior. Therefore, in the present invention, the preferable porosity of the center layer 1 is set in the range of 20 to 60%. The unit of the porosity is vol. %.

Next, the present inventors have repeatedly studied the relationship between the thickness of the outer layer 2, the bending rigidity of the panel, and the specific gravity of the panel. The result is shown in FIG.

As apparent from FIG. 2, when the thickness of the outer layer 2 is less than 0.2 mm, it is preferable in terms of weight reduction of the panel, but the bending rigidity becomes insufficient. On the other hand, when the thickness of the outer layer 2 exceeds 2 mm, although it is preferable in terms of the bending rigidity of the panel, the specific gravity of the plastic composite panel increases, the weight increases, and the improvement in workability as a concrete formwork panel is inferior. Therefore, in the present invention, the preferable thickness of the outer layer 2 is in the range of 0.2 to 2 mm, and the more preferable range is in the range of 0.8 to 1.5 mm.

The results in FIG. 2 are obtained when the total thickness of the panel is set to 13 mm. However, even when the total thickness of the panel is within the range of 10 to 30 mm, the case where the thickness is 13 mm is used. Almost the same result was obtained.

The outer layer 2 desirably has a low foaming structure in order to secure necessary bending rigidity, and its porosity is preferably 10% or less (including 0%).

The material forming the outer layer is made of a thermoplastic resin composition. Examples of the material include polyethylene, polypropylene, polyester, and polyamide. It is preferable that the material is a material that is melt-bonded to the surface layer 7 without using an adhesive or the like. . Such materials include polyethylene, polypropylene, etc.
Examples include polyolefin-based resins and composite materials containing these.

Further, an inorganic filler such as talc, mica, silica, titania, alumina, calcium carbonate and the like may be added to the outer layer 2 for securing rigidity and concealing property.

The thickness of the outer layer 2 is preferably about 2 to 20% of the total thickness of the panel. If it is less than 2%, it is difficult to secure necessary rigidity, and if it exceeds 20%, the specific gravity increases.

As long as the porosity of the outer surface of the outer layer 2 is not 0%, irregularities remain on the surface of the plastic composite panel of the present invention. In particular, in the case of used plastic, foaming occurs locally due to the influence of foreign substances contained therein, and craters are easily formed on the surface.

The present inventors have also studied this problem. As a result, it has been found that by forming the skin layer 3 on the outer surface of the outer layer 2, the surface properties of the panel can be improved (smoothed).

Furthermore, it has been found that the skin layer 3 made of a resin containing a thermoplastic resin or the like is fused to the outer surface of the outer layer 2 so that peeling of the skin layer 3 does not occur. In the case where the skin layer 3 and the outer layer 2 are fused, no problem occurs even if the outer layer 2 of the skin layer 3 is slightly mixed or compounded at the interface between the skin layer 3 and the outer layer 2.

The form of the material for forming the skin layer may be a film, cloth, nonwoven fabric, powder, etc., in addition to the sheet shape.
In addition, the material may be polyethylene, polypropylene, polyester, polyamide, paper, wood-based material, or other composite materials. However, when the skin layer 3 is fused to the outer surface of the outer layer 2, it is preferable that the material be a material that can be melt-bonded to the outer layer 2. Examples of such a material include polyolefin resins such as polyethylene and polypropylene, and composite materials containing these.

The thickness of the skin layer 3 is not particularly limited as long as the smoothness and surface properties of the outer surface of the outer layer 2 can be ensured.
It is preferably in the range of 0.2 to 2 mm. If the thickness is less than 0.2 mm, it is difficult to ensure smoothness. On the other hand, if the thickness exceeds 2 mm, the smoothness does not change. This is because the layer thickness must be reduced, which has an adverse effect on bending rigidity and specific gravity.

Further, the inventors have repeatedly studied the use (recycling) of waste as a raw material for a plastic composite panel in order to further increase the added value of the plastic composite panel.

As a result, even if the wood powder 5 such as sawdust is blended in at least the center layer 1 in the production stage, there is no problem. On the contrary, by mixing the wood powder 5, the specific gravity is slightly reduced, and the panel density is slightly reduced. It was found that the bending rigidity, the bending strength, the nailing property, the entanglement property of the resin on the saw blade at the time of sawing, and the like were improved as a whole. Moreover, it was found that when used plastics complying with the Containers and Packaging Recycling Law were used as a raw material for a plastic composite panel (described later), the off-flavor which was a problem was also greatly reduced to a level which was hardly noticeable.

The size of the wood powder 5 is preferably about 10 mm or less when mixed into the panel. If it exceeds 10 mm, a locally weak part is likely to be formed, and the strength of the panel is reduced. The compounding ratio is, for example, when compounded only in the center layer 1, with respect to the mass of the center layer 1, 50 mass% or less, preferably,
It is preferable to be within the range of 3 to 50 mass%.
If it is less than 3 mass%, the above-mentioned effects are reduced, while
If it exceeds 50 mass%, a locally weak portion is likely to be formed, and the strength of the panel is reduced.

In the present invention, in addition to wood powder, waste paper, pigments, organic and / or inorganic fibers, etc. can be contained uniformly in all layers or in each layer.

Further, as the plastic which is the main raw material of the plastic composite panel of the present invention, virgin plastic and used plastic as industrial waste or general waste can be applied. In the case of using used plastics as general waste, in consideration of the convenience of incineration and reuse after use, dechlorination vinyl treatment (wet specific gravity separation treatment, heating temperature control It is preferable to use a used plastic that has been subjected to form sorting after melt granulation) or dechlorination (eg, thermal decomposition).

Here, the used plastic as general waste is separated and discharged as general household waste.
Includes used plastic that complies with the Containers and Packaging Recycling Law, which is separated and collected by local governments. Used plastics that comply with the Containers and Packaging Recycling Law
It is mainly a mixture of general-purpose plastics such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyethylene terephthalate, and foreign substances such as metal foil, paper, and other seasonings.

The wet specific gravity separation process, which is one method of dechlorinating vinyl, is a method of separating crushed used plastic using a specific gravity liquid such as water having a specific gravity of about 1.0. Is separated into On the light specific gravity side,
Mainly polyethylene and polypropylene, some polystyrene and other contaminants that cannot be separated are collected. In the present invention, even if some foreign matter is mixed, it can be used as a main raw material of the plastic composite panel. If a light specific gravity treated with dechlorinated vinyl is used, its specific gravity is 1.0 or less, so that the weight can be reduced accordingly.

However, as described above, when the used plastic as general waste is used as the main raw material of the plastic composite panel without mixing the wood powder 6,
There was also a problem in that workers had a dislike because of the peculiar odor derived from the foreign matter.

Next, the present inventors have made intensive studies to improve the rigidity of the panel without forming the outer layer 2. As a result, as shown in FIG.
To form a surface layer 7, and a skin layer 3
It was found that it should be formed.

The porosity of the intermediate layer 6 is lower than the porosity of the center layer 1 and higher than the porosity of the surface layer 7. The porosity decreases almost continuously from the center layer 1 toward the surface layer 7. Middle layer 6
The surface layer 7 has the same composition as the center layer 1.
Thus, the outer layer 7 is provided outside the central layer 1 through the intermediate layer 6.
Is formed, the surface layer 7 contributes to the improvement in the rigidity of the panel, and the intermediate layer 6 contributes to the improvement in the peeling resistance of the surface layer 7. Therefore, the rigidity of the panel can be improved without forming the outer layer 2. it can.

That is, the second invention of the present invention has been made based on the above findings, and the boundary between the center layer 1 and the surface layer 7 of the foamed structure has a porosity equal to or less than the porosity of the center layer 1 and equal to or greater than the porosity of the surface layer 7. And an intermediate layer 6 whose porosity decreases almost continuously from the central layer 1 toward the surface layer 7.

The present inventors have studied a preferable porosity range of the surface layer 7. As a result, the porosity of the surface layer 7 was reduced to 5%.
It has been found that the following (including 0%) can substantially suppress a decrease in bending stiffness as a plastic composite panel. Therefore, in the present invention, the preferable porosity of the surface layer 7 is set to 5% or less (including 0%).

The present inventors have examined the preferable range of the thickness of the intermediate layer 6. As a result, if the thickness is less than 2% of the total thickness of the panel, the surface layer 7 is too thin and the surface layer 7 is easily peeled off from the center layer 1. On the other hand, if the thickness exceeds 20%, the center layer 1 or the surface layer 7 is accordingly reduced. When the center layer 1 is made thin, the thickness of the other layer having a small porosity becomes large, so that the specific gravity of the panel becomes large, and when the surface layer 7 is made thin, the rigidity decreases. . Therefore, in the present invention, the preferable thickness of the intermediate layer 6 is set to 2 to 20% of the total thickness of the panel.
Within the range.

Next, the present inventors conducted intensive studies to further increase the rigidity of the panel. As a result, as shown in FIG. 4, it has been found that in the panel of FIG. 3, the outer layer 2 may be further formed outside the surface layer 7.

That is, the third invention of the present invention has been made based on the above findings. In the panel shown in FIG. 3, an outer layer 2 similar to that in FIG. 1 is formed between a surface layer 7 and a skin layer 3. It consists of what you did.

Next, an example of a method of manufacturing the plastic composite panel of the first invention will be described with reference to the drawings.

As shown in FIG. 5, a raw material obtained by adding a foaming agent to a plastic material as a main raw material is supplied to a central layer extruder 8
And the outer layer forming material 2A is simultaneously charged into the outer layer extruder 9 to be softened and the two-layer three-layer T die 1
By extruding simultaneously from 0, the foam molded article 10A in which the outer layer 2 is fused to the outer surface of the central layer 1 is extrusion molded.
Next, the skin layer forming substance 3A is supplied to the surface of the foam molded article 10A, and the skin layer 3 is welded to the surface of the outer layer 2 by applying pressure by a belt-shaped press device 11. Then, both ends of the foamed structure 10B including the center layer 1, the outer layer 2, and the skin layer 3 thus obtained are cut by the cutting machine 12. Thus, the plastic composite panel 13 having the structure as shown in FIG. 1 is manufactured.

Next, an example of a method for manufacturing a plastic composite panel of the second invention will be described with reference to the drawings.

As shown in FIG. 6, a raw material obtained by adding a foaming agent to plastic as a main raw material is extruded while being melted by an extruder 8, and foamed to have a porosity equal to the porosity of the center layer 1. The molded body 10A is manufactured, and thereafter, the foamed molded body 1 is heated by the belt-shaped pressing device 11 at a temperature equal to or higher than the temperature at which the plastic on the surface of the foamed molded body 10A softens.
0A is pressed to soften the surface of the foam molded body 10A.
By compressing, the porosity of the surface portion is reduced, and the surface layer 7 is formed. At this time, the pressurizing temperature, pressurizing time,
The porosity of the central layer 1 is equal to or less than the porosity of the surface layer 7 by controlling the pressure applied to A,
Layer 6 whose porosity decreases almost continuously toward
Are also formed at the same time.

After the foam molded article 10A having the center layer 1, the intermediate layer 6, and the surface layer 7 is manufactured in this manner, the skin layer forming substance 3A is heated and pressurized while being supplied onto the surface layer of the foam molded article 10A. And the surface layer 7. Then, both ends of the foamed structure 10B including the center layer 1, the intermediate layer 6, the surface layer 7, and the skin layer 3 are cut by the cutting machine 12. Thereby, the plastic composite panel 13 as shown in FIG. 3 is manufactured.

The surface layer 7 and the intermediate layer 6 may be formed by supplying the skin layer forming substance 3A onto the outer surface of the central layer 1 after supplying the same.

Next, an example of a method of manufacturing the plastic composite panel of the third invention will be described with reference to the drawings.

As shown in FIG. 7, before the skin layer forming substance 3A is supplied onto the surface layer of the foam molded article 10A, the outer layer forming substance 2A is supplied onto the surface layer of the foam molded article 10A. The layer forming material 3A is supplied onto the surface of the outer layer 2 and integrated. The rest is the same as in the case of manufacturing the panel of the second invention.

In addition, there are the following two methods for manufacturing the plastic composite panel of the third invention.

A central layer having pores is formed, and then an outer layer forming material is supplied on the outer surface of the central layer. Then, the center layer is pressed while being heated together with the outer layer forming material to form the central layer. And forming an intermediate layer at the boundary between the central layer and the surface layer, and forming an outer layer on the outer surface of the surface layer, and then forming a skin on the outer surface of the outer layer. Supply the layer forming substance,
Then, the skin layer forming substance is pressurized while being heated to form a skin layer on the outer surface of the outer layer.

A central layer having pores and an outer layer on the outer surface of the central layer are simultaneously heated and formed, and then the central layer and the outer layer are pressed together to form a surface layer having a lower porosity than the central layer. And forming an intermediate layer at the boundary between the central layer and the surface layer, thereafter supplying a skin layer forming material to the outer surface of the outer layer, and applying pressure while heating the skin layer forming material. Thus, a skin layer is formed on the outer surface of the outer layer.

Since these manufacturing methods are all industrially easy, the plastic composite panel of the present invention can be obtained without causing a large increase in cost.

The present invention can be applied not only to the above-described concrete formwork panel and its manufacturing method, but also to other members requiring the same quality and its manufacturing method.

[0076]

Next, the first invention of the present application will be described more specifically with reference to examples.

The used plastic separated and recovered based on the Container and Packaging Recycling Method was pulverized, and components having a specific gravity of 1.0 or less were separated by a specific gravity separation method using an aqueous solvent. The separated light specific gravity pulverized product was appropriately washed, and used as a raw material 1. In addition, after removing the nails and the like from the pier collected from the formwork construction site by using a magnetic separator as needed, the wood powder is crushed by a crusher until the entire length becomes 3 mm or less, and this is used as raw material. And 2.

The raw material 1, the raw material 2, and the azodicarbondiamine-based nucleating agent as a chemical foaming agent were mixed by a mixing machine at the ratios shown in Tables 1 to 3, respectively. Single screw extruder 8 for layer
It was put in. At the same time, the polypropylene resin
The composition prepared by adding 20 mass% of the filler shown in (1) was used, and this was charged into the outer layer shaft extruder 9.

Next, while being bonded in a molten state by a two-type three-layer T-die 10, a foamed molded product 10A having a thickness of about 12 mm and a width of about 0.8 m, comprising the center layer 1 and the outer layer 2, was extruded. Next, the skin layer forming substance 3A is supplied onto the surface of the foam molded article 10A thus formed, and the foam molded article 10A is introduced into the belt-shaped press device 11, and the surface of the foam molded article 10A is softened. -By compression, the foamed structure 10B as shown in FIG. 1 was formed, comprising the central layer 1 having a high porosity, the outer layer 2 and the skin layer 3 integrated by fusion.

Then, the foamed structure 10B including the center layer 1, the outer layer 2, and the skin layer 3 is cut by the cutting machine 12, and finally has a width of 600 mm, a length of 1800 mm, and a thickness of 1 mm.
A 2 mm plastic composite panel 13, that is, inventive examples 1 to 10 and comparative examples 1 to 3 and 5 were produced. Each panel was subjected to the tests shown in Tables 1 to 3 to evaluate the performance. The results are shown in Tables 1 to 3.

As Comparative Example 4, Table 3 also shows the results of the performance evaluation of the South Sea wood plywood panel. The tests and evaluation methods in Tables 1 to 3 are as follows.

Bending stiffness (Bending Young's modulus): Calculated by conducting a bending test in accordance with the method prescribed in Japanese Agricultural Standards “Plywood for concrete formwork”.

Bending strength: A bending test was performed in accordance with JIS K-7171 and calculated.

Specific gravity: Calculated from the volume calculated from the dimensions of the plate and the mass.

Smoothness: Judgment was made based on the surface condition of the concrete surface when used as a formwork panel. A good mark was indicated by a circle, a slightly poor mark was indicated by a mark, and a poor mark was indicated by a cross mark.

The number of reusable times is the number of reusable times before the concrete formwork can be reused due to cracking or peeling of the surface layer when used as a test concrete.

Sawability: Panels having a width of 600 mm are repeatedly cut in the width direction with an electric saw, and wood for piers is cut at a rate of once every five times. Judgment is made based on the number of panel cuts until the sharpness of the wood is reduced. did.

Nail habitability: A pier of 40 × 40 mm was placed on the back of the panel, and the nail was hit with 100 nails from the surface, and evaluated by the rate (%) at which cracks occurred on the panel surface.

Odor: A mark that is hardly noticed
Somewhat anxious were marked with △, and those of interest were marked with x.

Comprehensive evaluation: Workability when used as a concrete formwork on a test basis. Those that can be used almost equally as wood plywood panels are marked with a circle, and the timber plywood panels are partially changed in the arrangement of crosspieces. Those that can be used equivalently to △ and those that cannot be used equivalently to timber plywood panels are marked X.

[0091]

[Table 1]

[0092]

[Table 2]

[0093]

[Table 3]

As is clear from Tables 1 and 2, all of Examples 1 to 10 of the present invention have performances that can substitute wood plywood panels in various performances required for concrete formwork panels. .

In Example 5, the specific gravity was large because the porosity of the central layer was small, and in Example 6, there was no odor because wood powder was not added. In Example 8, the skin layer forming substance was Although it was a PP nonwoven fabric, it was slightly inferior in smoothness, but had sufficient performance to substitute a wood plywood panel.

On the other hand, as is apparent from Table 3,
Comparative Example 1 was inferior in bending Young's modulus and bending strength because the porosity of the center layer was larger than the range of the present invention.

In Comparative Example 2, since the porosity of the center layer was smaller than the range of the present invention, the bending Young's modulus and the bending strength were sufficient, but the specific gravity was large.

Comparative Example 3 was inferior in flexural Young's modulus and flexural strength because the porosity of the outer layer exceeded the range of the present invention.

Comparative Example 5 was inferior in smoothness because there was no skin layer.

Next, the second invention will be described more specifically with reference to examples.

The raw material 1 and the raw material 2 and the azodicarbondiamine-based nucleating agent as a chemical foaming agent were mixed at a ratio shown in Tables 4 to 6 by a mixing machine.
The foamed molded product 10 having a thickness of about 12 mm and a width of about 0.8 m is put into the uniaxial extruder 8 of the continuous panel manufacturing machine shown in FIG.
A was extruded. By pressing the outer layer surface of the foam molded body 10A thus formed under various conditions by a belt-shaped press device 11 to soften and compress the surface portion of the foam molded body 10A, a center having a high porosity is obtained. Foamed structure 10B comprising a layer, a surface layer having a low porosity, and an intermediate layer in which the porosity decreases almost continuously from the center layer toward the surface layer
Was molded. The thickness of the intermediate layer was approximately 1 mm.

Next, on both sides of the foam molded article 10A,
0.5 mm thick thermoplastic resin skin layer forming substance 3A
Heating and pressurizing while supplying the skin layer forming substance 3
A was fused to the outer surface of the surface layer 7.

Then, both ends of the foamed structure 10B are cut by a cutting machine 12, and finally a plastic composite panel 13 having a width of 600 mm, a length of 1800 mm and a thickness of 12 mm, ie, Examples 1 to 10 of the present invention and Comparative Examples Examples 1 to 3 and 5 were prepared. Each panel was subjected to the tests shown in Tables 4 to 6 to evaluate the performance. The results are shown in Tables 4 to 6.

As Comparative Example 4, Table 6 also shows the results of the performance evaluation of the South Sea wood plywood panel. The tests and evaluation methods in Tables 4 to 6 are the same as those described above.

[0105]

[Table 4]

[0106]

[Table 5]

[0107]

[Table 6]

As is evident from Tables 4 and 5, Examples 1 to 10 of the present invention were found to have performances that could replace wood plywood panels in various performances required for concrete formwork panels. . Example 1
Has a large specific gravity because the porosity of the central layer is small, and in Example 6, although wood powder was not blended, there was an odor, but it had a performance capable of sufficiently replacing a wood plywood panel.

On the other hand, as is apparent from Table 6,
Comparative Example 1 was inferior in bending Young's modulus and bending strength because the porosity of the center layer was larger than the range of the present invention.

In Comparative Example 2, since the porosity of the center layer was smaller than the range of the present invention, the specific gravity was large although the bending Young's modulus and the bending strength were sufficient.

Comparative Example 3 was inferior in flexural Young's modulus and flexural strength because the porosity of the surface layer was larger than the range of the present invention.

In Comparative Example 5, since there was no skin layer, the smoothness was poor.

Next, the third invention of the present case will be described more specifically with reference to examples.

The raw material 1 and the raw material 2 and the azodicarbondiamine-based nucleating agent as a chemical foaming agent were mixed at a ratio shown in Tables 7 to 9 by a mixing machine, respectively.
The foamed molded product 10 having a thickness of about 12 mm and a width of about 0.8 m was put into the uniaxial extruder 8 of the continuous panel manufacturing machine shown in FIG.
A was extruded. By pressing the outer layer surface of the foam molded body 10A thus formed under various conditions by a belt-shaped press device 11 to soften and compress the surface portion of the foam molded body 10A, a center having a high porosity is obtained. Foamed structure 10B comprising a layer, a surface layer having a low porosity, and an intermediate layer in which the porosity decreases almost continuously from the center layer toward the surface layer
Was molded. The thickness of the intermediate layer was approximately 1 mm.

Next, on both sides of the foam molded article 10B,
Heating and pressurization were performed while supplying a thermoplastic resin outer layer forming material 2A having a thickness of 0.5 mm to fuse the outer layer forming material 2A to the outer surface of the surface layer 7. Next, heating and pressurization were performed while supplying the thermoplastic resin skin layer forming substance 3A, so that the skin layer forming substance 3A was fused to the outer surface of the outer layer 2.

Then, both ends of the foamed structure 10B are cut by a cutting machine 12, and finally a plastic composite panel 13 having a width of 600 mm, a length of 1800 mm, and a thickness of 12 mm, ie, Examples 1 to 15 of the present invention and Comparative Examples Examples 1 to 3 and 5 to 9 were prepared. Each panel was subjected to the tests shown in Tables 7 to 11 to evaluate the performance. The results are shown in Tables 7 to 11.

As Comparative Example 4, Table 10 also shows the results of the performance evaluation of the South Sea wood plywood panel. Table 7 to 1
The test and evaluation methods at 0 are the same as described above.

[0118]

[Table 7]

[0119]

[Table 8]

[0120]

[Table 9]

[0121]

[Table 10]

[0122]

[Table 11]

As is clear from Tables 7 to 9, it was found that Examples 1 to 15 of the present invention all had various performances required for concrete formwork panels and could substitute wood plywood panels. .

On the other hand, as apparent from Tables 10 and 11, Comparative Example 1 was inferior in the bending Young's modulus and the bending strength because the porosity of the center layer was larger than the range of the present invention.

In Comparative Example 2, since the porosity of the center layer was smaller than the range of the present invention, the bending Young's modulus and the bending strength were sufficient, but the specific gravity was large.

Comparative Example 3 was inferior in flexural Young's modulus and flexural strength because the porosity of the surface layer was larger than the range of the present invention.

Comparative Example 5 was inferior in smoothness, bending Young's modulus and bending strength because there was no skin layer and no surface layer.

In Comparative Example 6, since there was no surface layer, the bending Young's modulus and the bending strength were inferior.

In Comparative Example 7, since the thickness of the surface layer was large, the specific gravity was large.

In Comparative Example 8, since there was no skin layer, the smoothness was poor.

Comparative Example 9 was inferior in smoothness, bending Young's modulus and bending strength because there was no outer layer.

The above-mentioned formwork panels of the present invention are excellent in recyclability, for example, they can be blown into a blast furnace as industrial waste after use, and can be chemically recycled instead of coke. It turned out to be.

[0133]

As described above, according to the present invention, a wood plywood panel which satisfies the required flexural rigidity and lightness, has excellent nailing properties, sawing properties, and surface smoothness, is sufficiently provided. It has a performance that can be used as a substitute for wood, and has a greater number of diversion times than wood plywood panels.Furthermore, such panels are discharged from used plastics, especially from general households covered by the Containers and Packaging Recycling Law. Providing used plastic as a raw material has great industrial significance from the viewpoint of preventing global warming, and the panel of the present invention can be chemically recycled as a raw material for steel by blowing it into a blast furnace after use. Therefore, there is an effect that the total carbon dioxide reduction effect is very large.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a panel of the first invention of the present application.

FIG. 2 is a graph showing a relationship between outer layer thickness and bending rigidity.

FIG. 3 is a sectional view showing the panel of the second invention.

FIG. 4 is a sectional view showing the panel of the third invention.

FIG. 5 is a schematic sectional view showing a continuous panel manufacturing machine of the first invention of the present application.

FIG. 6 is a schematic sectional view showing a continuous panel manufacturing machine of the second invention.

FIG. 7 is a schematic sectional view showing a continuous panel manufacturing machine according to the third invention.

[Explanation of symbols]

 1: center layer 2: outer layer 2A: outer layer forming substance 3: skin layer 3A: skin layer forming substance 4: air bubbles 5: wood powder 6: intermediate layer 7: surface layer 8: extruder for central layer 9: extrusion for outer layer Machine 10A: Foamed molded body 10B: Foamed structure 11: Pressing device 12: Cutting machine 13: Panel 12: Extrusion molding machine for outer layer 13: T die

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidekazu Tsuruta 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Yasuhiro Harada 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Sun Inside Honko K.K. JL03 JL16 YY00A YY00B

Claims (15)

[Claims] 1. A plastic composite panel mainly made of plastic, comprising: a central layer; an outer layer formed outside the central layer; and a skin layer formed outside the outer layer. Plastic composite panel. 2. The plastic composite panel according to claim 1, wherein the porosity of the outer layer is 10% or less. 3. A plastic composite panel mainly made of plastic, comprising: a central layer, an intermediate layer formed outside the central layer, a surface layer formed outside the intermediate layer, and formed outside the surface layer. Having a skin layer, the porosity of the central layer is higher than the porosity of the surface layer, the average porosity of the intermediate layer,
A plastic composite panel, wherein the porosity is equal to or less than the porosity of the center layer, equal to or greater than the porosity of the surface layer, and the porosity of the intermediate layer decreases substantially continuously from the center layer toward the surface layer. . 4. The plastic composite panel according to claim 3, wherein the porosity of the surface layer is 5% or less. 5. A plastic composite panel mainly made of plastic, comprising: a central layer, an intermediate layer formed outside the central layer, a surface layer formed outside the intermediate layer, and formed outside the surface layer. And a skin layer formed outside the outer layer, wherein the porosity of the central layer is higher than the porosity of the surface layer, and the average porosity of the intermediate layer is the porosity of the central layer. A plastic composite panel, wherein the porosity is less than or equal to the porosity of the surface layer, and the porosity of the intermediate layer decreases substantially continuously from the central layer toward the surface layer. 6. The plastic composite panel according to claim 5, wherein the porosity of the surface layer is 5% or less. 7. The plastic composite panel according to claim 5, wherein a porosity of the outer layer is 10% or less. 8. The porosity of the central layer is 20 to 60%.
The plastic composite panel according to any one of claims 1 to 7, characterized in that: 9. The thickness of the skin layer is from 0.2 to 2 m.
The plastic composite panel according to any one of claims 1 to 8, wherein m is within a range of m. 10. The plastic composite panel according to claim 1, further comprising wood powder. 11. The plastic composite panel according to claim 1, wherein the plastic includes a plastic that has been dechlorinated or dechlorinated. 12. A center layer having pores is formed, and then the surface of the center layer is pressed to form a surface layer having a lower porosity than the center layer, and a boundary layer between the center layer and the surface layer is formed. Forming a middle layer having a porosity equal to or less than the porosity of the central layer and equal to or greater than the porosity of the surface layer, wherein the porosity decreases almost continuously from the center layer toward the surface layer,
Manufacturing a plastic composite panel, wherein a skin layer forming substance is supplied to the outer surface of the surface layer, and the skin layer forming substance is pressurized while heating to form a skin layer on the outer surface of the surface layer. Method. 13. Forming a central layer having pores, supplying a skin layer forming substance on the outer surface of the central layer, and then pressing the central layer together with the skin layer forming substance while heating. Pressurizing the central layer together with the skin layer forming substance while heating, to form a surface layer having a lower porosity than the central layer, and at the boundary between the central layer and the surface layer, the porosity of the central layer. Hereinafter, an intermediate layer having a porosity equal to or higher than the porosity of the surface layer, in which the porosity decreases almost continuously from the center layer toward the surface layer, and a skin layer is formed on the outer surface of the surface layer A method for producing a plastic composite panel, comprising: 14. Forming a central layer having pores, then supplying an outer layer forming substance on the outer surface of the central layer, and then pressing the central layer together with the outer layer forming substance while heating, While forming a surface layer having a lower porosity than the center layer, at the boundary between the center layer and the surface layer, the porosity of the center layer is less than or equal to or greater than the porosity of the surface layer. Forming an intermediate layer having a porosity almost continuously reduced, and forming an outer layer on the outer surface of the surface layer, thereafter supplying a skin layer forming material to the outer surface of the outer layer, and A method for producing a plastic composite panel, wherein a skin layer is formed on an outer surface of the outer layer by applying pressure while heating a skin layer forming substance. 15. A central layer having pores and an outer layer on the outer surface of the central layer are simultaneously formed by heating, and then the central layer and the outer layer are pressed together to have a porosity higher than that of the central layer. A low surface layer is formed, and at the boundary between the center layer and the surface layer, the porosity is substantially continuous from the center layer toward the surface layer at a porosity equal to or less than the porosity of the center layer and equal to or greater than the porosity of the surface layer. Forming a reduced intermediate layer, then supplying a skin layer forming material to the outer surface of the outer layer, and pressurizing the skin layer forming material while heating,
A method of manufacturing a plastic composite panel, comprising forming a skin layer on an outer surface of the outer layer.