JPH06155433A - Board material for concrete form - Google Patents

Abstract

PURPOSE:To improve the bending strength and rigidity, both of which withstand the large load at the construction of concrete, and surface smoothness and releasability on the surface properties of the constructed concrete. CONSTITUTION:The board material concerned consists of porous thermoplastic resin layer 2, which is reinforced by fibers or non-woven material produced by paper-making method, and the thermoplastic resin layer 3, which is laminated onto one side or both sides of the layer 2 and has the thickness of 0.2-2mm. The reinforcing fibers and air bubbles of the fiber reinforced thermoplastic resin layer 2 are covered by the laminated surface of the thermoplastic resin layer 3 under the condition that the total apparent density is set to be 0.3-1g/cm<3> and the basis weight is set to be 4,500g/m<2> or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate material for concrete formwork (hereinafter referred to as a formwork plate material) which is a fiber-reinforced thermoplastic resin porous molded product. INDUSTRIAL APPLICABILITY The plate material for a formwork of the present invention can be widely used for construction such as construction and civil engineering where wood has been conventionally used.

[0002]

2. Description of the Related Art In recent years, due to global environmental problems, the cutting of South Sea timber has been regarded as a problem. Traditionally, Nanyo wood has been processed into plywood, and has been used in large quantities as a plate material for formwork during concrete construction such as construction and civil engineering, and it is desired to develop alternative materials. The plate material for formwork is required to have bending strength and rigidity capable of withstanding a large load during concrete construction, and surface smoothness and mold releasability related to the surface properties of the constructed concrete.

As a substitute for the plate material for wood formwork that has been conventionally used, a fiber reinforced thermoplastic resin molded product composed of a relatively long reinforcing fiber and a thermoplastic resin is relatively lightweight and high in characteristics. It is attracting attention because of its strength and rigidity. However, the density of the fiber reinforced thermoplastic resin molded product is 1 to 1.3 g / cm ^3, which is 0.5 of wood plywood.
It can not be said lighter than ~0.7g / cm ^3, the strength of wood plywood the same level, in order to express the stiffness leads to increase in the weight of the product, leading to cost-up of the product. Further, since glass fiber, which is a typical reinforcing fiber, easily adheres to concrete, its releasability from concrete becomes a problem.

As a method for improving the mechanical properties and reducing the weight of a fiber-reinforced thermoplastic resin molded product, a papermaking method (Japanese Patent Publication No.
No. 2-12283, Japanese Patent Publication No. 55-9119)
According to the method for producing a porous molded article using a sheet-shaped molding material (JP-A-60-179234, JP-A-62-1).
No. 61529) has been proposed. This porous molded product is molded by utilizing the sheet expansion that occurs when the sheet-shaped molding material is heated to the softening point or melting point of the thermoplastic resin which is the matrix before molding.

The sheet-shaped molding material is produced by applying a papermaking technique to uniformly disperse reinforcing fibers having a diameter of 3 to 30 μm and a length of 3 to 50 mm and a thermoplastic resin powder to produce a non-woven material. It is manufactured by using the material as a raw material, heating, pressurizing, and further cooling. The non-woven material produced by the papermaking method has a property that it is very bulky because the reinforcing fibers are dispersed in the state of monofilaments (single fibers). The thickness of the non-woven material varies depending on the content of reinforcing fibers, its shape, and papermaking conditions, but is about 10 times as thick as that of a sheet from which voids are generally used as a sheet-shaped forming material. The heating of the sheet-shaped molding material weakens the binding force of the thermoplastic resin to the reinforcing fibers, so that the residual stress of the reinforcing fibers is released, and the sheet-shaped molding material expands due to the springback to return to the original state. This expanded sheet-shaped molding material is inserted into a molding die, and a clearance is set within a range that is less than the expanded sheet thickness and leaves a void to be included, and pressurization and cooling molding are performed under the condition that a desired expansion ratio is obtained. By
A porous molded article is manufactured.

Although the strength and elastic modulus per area of the porous molded product are lowered due to expansion, the molded product can be made thicker with a constant weight, and the flexural strength of the molded product is determined by the material thickness. Since the bending rigidity is proportional to the cube of the plate thickness of the molded product, the mechanical properties are improved and the weight is reduced as compared with a normal fiber-reinforced thermoplastic resin molded product.

However, in the porous molded article molded by the above method, the appearance and mechanical properties cannot be said to be sufficient as a mold plate material as described below. An example of a conventional method for forming a porous molded article is shown in FIG. The sheet-shaped molding material 13 is generally heated in a far infrared heating furnace 14 to a temperature above the softening point or melting point of the thermoplastic resin. The expansion of the sheet-shaped molding material starts from the surface of the sheet that is first heated, and gradually expands as the heat reaches the center of the plate thickness. However, due to the expansion, a heat insulating air layer is formed inside the sheet, so that the thermal conductivity is reduced. This decrease in thermal conductivity causes uneven sheet expansion. The sheet-shaped molding material expands greatly in the vicinity of the surface, but since it is heated in the state where heat from far infrared rays is not sufficiently transmitted inside the sheet, thermal expansion of the thermoplastic resin occurs due to local heating on the expanded sheet surface. . The adverse effect of this thermal expansion is amplified as the initial thickness of the sheet-shaped molding material increases. As a result, a plate thickness of 3.5 mm or more (basis weight 450
When heating a sheet-shaped molding material having a surface weight of 0 g / m ² or more and a grammage: the weight of the sheet-shaped molding material per unit area), it is necessary to avoid local heating of the surface, and thus a layer expanded near the surface (1
5), a layer (16) is formed which has hardly expanded inside.

Further, since the sheet-shaped molding material expands in an unloaded state, irregularities 17 are formed on the surface. The unevenness of the surface portion occurs because the reinforcing fibers in the sheet-shaped molding material are randomly oriented, and springback occurs unevenly in the sheet. Further, on the sheet surface, the reinforcing fibers are exposed by spring back (18), and the appearance is significantly deteriorated. This expanded sheet-shaped forming material is inserted into the cooling press platen 12, and the clearance is set to be equal to or less than the expanded sheet thickness and to leave a void to be included therein.
Press and cool and mold under the conditions to obtain the desired expansion ratio,
The porous molded product 19 is manufactured.

Since the porous molded article is low-pressure, cold-molded by setting the clearance, it is not possible to improve the appearance by flowing the thermoplastic resin of the heated sheet-shaped molding material. As a result, since the appearance of the porous molded article inherits the appearance of the expanded heating sheet, wrinkles 20 due to the unevenness of the sheet surface and exposure of the reinforcing fibers 19 cause deterioration of the appearance.

The heat-expanded sheet-shaped molding material has a structure in which crossing portions of reinforcing fibers that are three-dimensionally randomly oriented are fused by a thermoplastic resin, and a porous molded product is formed by freezing this structure. As a result, air bubbles exist inside and on the surface of the porous molded product. In addition, the expanded state of the porous molded product is similar to the sheet-shaped molding material, since the vicinity of the surface is large and the inside has hardly expanded, so when the product is bent, the surface part to which tension and compression loads are mechanically The structure becomes weak and mechanical properties deteriorate.

As a result, when this porous molded product is used as a plate material for formwork, the smoothness of the concrete construction surface is deteriorated due to surface wrinkles, and concrete penetrates into the air bubbles inside the porous molded product to strengthen it. There is a problem that the mold releasability decreases due to the adhesion with the fibers, and the flexure of the form plate material under a large load during concrete construction is transferred to the concrete construction surface, resulting in a decrease in smoothness.

[0012]

DISCLOSURE OF THE INVENTION The present invention is a formwork having improved bending strength and rigidity capable of withstanding a large load during concrete construction, and surface smoothness and mold releasability relating to the surface properties of the constructed concrete. Providing board materials.

[0013]

The gist of the present invention is as follows. (1) A fiber-reinforced thermoplastic resin layer comprising a porous fiber-reinforced thermoplastic resin layer made of a non-woven material produced by a papermaking method and a thermoplastic resin layer having a thickness of 0.2 to 2 mm laminated on one side or both sides thereof. A concrete mold in which the reinforcing fibers and bubbles of the resin layer are covered by the laminated surface of the thermoplastic resin layer, the overall apparent density is 0.3 to 1 g / cm ³ , and the basis weight is 4500 g / m ² or more. Frame plate material. (2) The plate material for concrete formwork according to the above (1), wherein the reinforcing fiber content of the fiber-reinforced thermoplastic resin layer is 10% by volume or more. (3) The thermoplastic resin layer comprises an inorganic filler-containing thermoplastic resin layer and a thickness of 0.01 to 1 arranged further outside thereof.
The plate material for concrete formwork according to the above (1) or (2), which comprises a thermoplastic resin layer having a thickness of mm. (4) The plate material for concrete formwork according to any one of (1) to (3) above, wherein the surface of one side or both sides is subjected to unevenness processing (texturing) of a decorative pattern.

An example of the form plate material of the present invention is shown in FIG. The mold plate material 1 of the present invention comprises a porous fiber-reinforced thermoplastic resin layer 2 and a thermoplastic resin layer 3 having a thickness of 0.2 to 2 mm laminated on one side or both sides thereof, and the overall apparent density is It is 0.3 to 1 g / cm ³ , and the basis weight is 4500 g / m ² or more. Apparent density is the product weight divided by its volume.

Since the fiber-reinforced thermoplastic resin layer 2 is uniformly expanded and the crossing portions of the reinforcing fibers 4 are efficiently adhered by the thermoplastic resin 5, excellent mechanical properties can be obtained. Further, the thermoplastic resin layer 3 on the surface has very excellent smoothness and covers the fiber reinforced thermoplastic resin layer 2, and therefore exhibits good performance as a plywood for formwork. That is, the plate material 1 for formwork of the present invention has bending strength and rigidity capable of withstanding a large load at the time of concrete construction, and the good smooth surface improves the surface property of the concrete, and the reinforcing fiber and the fiber reinforced Since the bubbles of the thermoplastic resin layer 2 are covered with the thermoplastic resin layer 3 on the surface, the problem of mold releasability due to intrusion and adhesion of concrete is solved.

FIG. 2 shows an example of a method for molding the plate material 1 for a mold according to the present invention. A thermoplastic resin film 7 is laminated on one side or both sides of a non-woven material 6 made of a reinforcing fiber and a thermoplastic resin produced by a papermaking method, and a plate-like body 8 having a smooth surface is superposed on both sides of this laminated body. Heating press machine 9
Insert inside and heat until the thermoplastic resin melts. After the thermoplastic resin is heated until it is melted, the thermoplastic resin is impregnated between the reinforcing fibers, so that pressure is applied at a pressure that does not cause fiber breakage (10). Subsequently, the pressure is removed while the thermoplastic resin is still molten, and the nonwoven material is expanded by the springback of the reinforcing fiber (11), and the expanded nonwoven material, the thermoplastic resin film, and the plate-like material are expanded. With the bodies superposed, they are inserted into the cooling press board 12, and the clearance is set to a range not more than the thickness of these expanded laminates and to a range in which voids included in the fiber-reinforced thermoplastic resin layer remain. By pressurizing, cooling and molding under the condition that the expansion ratio is obtained, and removing the plate-shaped body, the plate material 1 for formwork of the present invention is molded.

In the molding method of FIG. 2, the heating, pressurizing step and the pressurizing and cooling steps were carried out by separate dedicated press machines, but heating, pressurizing, depressurizing and cooling molding were carried out by one press machine. You can also do it. In addition, preheating the non-woven material for the purpose of shortening the heating time of the non-woven material on the hot press machine is preferable because it shortens the molding cycle. For the preheating of the non-woven material, there is used a method of passing hot air for heating in a short time by utilizing air permeability of the non-woven material, or heating by an oven.

When a sheet-shaped molding material obtained by heating, pressurizing and cooling the non-woven material is used instead of the non-woven material,
Similarly, expansion due to springback of the reinforcing fibers occurs, and the plate material for a mold of the present invention can be obtained. However, in this case, the entire process becomes long due to the forming process of the sheet-shaped forming material, which is not efficient. Since the form plate material formed by this method has an unstable peripheral shape, the product shown in FIG. 1 is actually obtained and used by trimming the periphery of the formed product.

Since the expansion of the nonwoven material is caused by the springback of the reinforcing fibers, the type of the reinforcing fibers (rigidity),
It changes depending on its content. The degree of porosity as a plate material for the form depends on the degree of expansion of the fiber-reinforced thermoplastic resin layer, but the overall apparent density is determined from the range of 0.3 to 1 g / cm ³ depending on the application. .

The reinforcing fibers used as the raw material for the non-woven material include:
In addition to glass fibers, carbon fibers, and metal fibers, inorganic fibers, organic fibers, and a mixture thereof may be used depending on the application.
The shape of the reinforcing fiber is preferably 3 μm or more from the viewpoint of easy handling and economical, and 30 μm or less in order to express sufficient strength, and the fiber length is 3 mm or more from the viewpoint of strength development, and is uniform. It is desirable to set the thickness to 50 mm or less, which allows various dispersion. The reinforcing fiber is a water-soluble polymer for improving hydrophilicity for the purpose of good dispersion in water, a wetting agent, and a silane coupling agent for improving adhesiveness with the thermoplastic resin for expressing strength. For example, it is desirable to perform surface treatment.

The thermoplastic resin is polyethylene, polypropylene, polystyrene, styrene-butadiene-acrylonitrile copolymer, styrene-acrylonitrile copolymer, polyamide, polycarbonate, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polyphenylene oxide, polysulfone, polyphenylene sulfide. Such as a plasticizer, a heat stabilizer, a light stabilizer, a filler, and the like, which also include a mixture of two or more of these resins.
A face wash, an impact resistance agent, a filler, a nucleating agent, a processing aid and the like can be added. The shape of the thermoplastic resin is appropriately selected from pellets, powders, flakes, and fibrous shapes.

The content of the reinforcing fiber is 10% by volume or more at which stable expansion by springback occurs, and 40% by volume or less at which the reinforcing fiber and the thermoplastic resin can be bonded and mechanical properties are sufficiently exhibited. Is desirable.

The thermoplastic resin film laminated on one side or both sides of the non-woven material is generally used in non-woven materials because it is necessary to fuse with the fiber reinforced thermoplastic resin layer to form a form plate material. Use the same resin used. However, if it is necessary to improve the mold releasability with concrete, heat resistance, surface hardness, wear resistance, etc., the surface layer part will consist of a thermoplastic resin, a mixture with different resins, or a different resin film depending on the purpose. The laminated film may be used in consideration of the melting point, compatibility, etc. of the thermoplastic resin of the non-woven material. The thickness of the thermoplastic resin film is appropriately selected within the range of 0.2 to 2 mm depending on the application.

It is also possible to use a thermoplastic resin film to which an inorganic filler is added. As the inorganic filler to be added, particulate fillers such as calcium carbonate and talc, flaky fillers such as mica, fibrous fillers such as chopped glass fibers and rock wool fibers are used. The inorganic filler is preferably surface-treated with a silane coupling agent or the like in order to improve the adhesiveness with the thermoplastic resin. The inorganic filler is appropriately selected according to the application. Further, a mixture of two or more kinds of the above inorganic fillers may be added. The amount of the inorganic filler added is 3% by volume or more for the purpose of improving the molten clay of the thermoplastic resin and strengthening the surface layer portion, and 30% by volume that enables stable film formation.
Below. However, since the inorganic filler has a property of easily adhering to concrete, a thermoplastic resin film can be laminated on the outermost surface in order to maintain releasability from concrete. The thermoplastic resin film containing an inorganic filler is in the range of 0.1 to 2 mm, and the thickness of the thermoplastic resin film is in the range of 0.01 to 1 mm, and is appropriately selected depending on the application.

As the plate-like member, the same one as in the manufacturing process of the sheet-shaped forming material is used. The sheet-shaped molding material is obtained by laminating plate-shaped bodies having smooth surfaces on both sides of a non-woven material, heating the thermoplastic resin to a temperature equal to or higher than the melting point or softening point, and then pressing the thermoplastic resin between the reinforcing fibers. It is manufactured by impregnation and further cooling. The material of the plate-shaped body may be any material as long as it can withstand the heating temperature, and examples thereof include metal, inorganic material and resin. These plate-like bodies must have a property that the thermoplastic resin adheres in the molten state but does not adhere in the non-melted state, and is coated with Teflon resin or the like in consideration of the releasability of the sheet-shaped molding material. Alternatively, a release agent treatment such as silicon may be performed.

The heating of the non-woven material and the thermoplastic resin film is carried out by contact heating of a temperature-controlled heating press machine under a very small pressure which does not damage the reinforcing fibers even when the thermoplastic resin is solidified. . The thermoplastic resin of the non-woven material gradually melts from the outside, but the distance between the plate-like bodies (thickness of the non-woven material) decreases accordingly, uniform heating is performed, and the thermoplastic resin does not deteriorate. As a result, it is possible to avoid the adverse effect of heat expansion of the sheet-shaped molding material, which has been observed in the conventional molding of porous molded articles, and it is possible to increase the thickness of the fiber-reinforced thermoplastic resin layer.

Subsequently, since the thermoplastic resin is impregnated between the reinforcing fibers in the molten state of the thermoplastic resin of the non-woven material, pressurization is performed at a pressure that does not cause fiber breakage. Further, the pressure is removed while the thermoplastic resin is molten. The nonwoven material expands due to the springback of the reinforcing fibers. Nonwoven materials produced by the papermaking method have reinforcing fibers dispersed in the form of monofilaments (single fibers).
Large expansion due to springback. Also, since the nonwoven material is heated uniformly, a uniform expansion is obtained.
Insert the expanded non-woven material, thermoplastic resin film, and plate into the cooling press board in the state of overlapping, set the clearance to obtain the desired expansion ratio, pressurize, cool mold, and fiber reinforced. The expanded state of the thermoplastic resin layer is frozen to mold the form plate material of the present invention.

The form plate material of the present invention requires bending strength and rigidity, and therefore has a basis weight of 4 which is a problem in conventional porous molded articles.
It is molded at 500 g / m ² or more. However, basis weight 4500 g
Even when it is / m ² or less, it is possible to obtain a molded product having excellent mechanical properties and appearance as compared with the conventional porous molded product.

The pressure impregnation of the non-woven material improves the leakability of the reinforcing fibers and the thermoplastic resin. Therefore, when the fiber-reinforced thermoplastic resin layer is uniformly expanded, the intersecting portions of the reinforcing fibers are efficiently made of the thermoplastic resin. Adhered and the mechanical properties of the formwork plate are improved. The thermoplastic resin in the non-woven material is impregnated between the reinforcing fibers at the time of pressurization, but at the same time, it is leached at the interface with the plate-like material and is stable in combination with the molten resin of the film existing at the interface. A resin rich layer is formed and both are firmly fused. Since the surface of the non-woven material expands in a state of being constrained by the surface of the plate-shaped body, the reinforcing fibers of the fiber-reinforced thermoplastic resin layer inside the form plate material and bubbles are covered by the resin-rich layer on the surface.

In the lamination of the thermoplastic resin film, when the content of the reinforcing fiber of the non-woven material is 30% by volume or more, the amount of the thermoplastic resin that oozes out is small, so that a stable resin-rich layer is formed. Exert the effect of. Further, due to this restraint expansion, the surface of the plate-like body is transferred to the surface of the plate material for formwork, and a good smooth surface is obtained. Similarly, when the plate-shaped body on which the decorative pattern has been subjected to concavo-convex processing (texture processing) is used under constrained expansion, the decorative pattern can be easily transferred to the surface of the plate material for formwork.

As a result, flexural strength and rigidity capable of withstanding a large load at the time of concrete construction, which is required as a plate material for formwork, and surface smoothness and releasability relating to the surface properties of the constructed concrete are achieved. To be done. INDUSTRIAL APPLICABILITY The form plate material of the present invention has excellent mechanical properties and appearance, and thus is an excellent substitute for wood and can be widely applied to industrial materials in which wood has been conventionally used.

[0032]

The present invention will be described in detail with reference to the following examples. Example 1 A glass fiber having a diameter of 10 μm and a length of 13 mm as a reinforcing fiber and a spherical pellet having a diameter of 3 mm as a thermoplastic resin were mechanically crushed, and the crushed product was sieved to from 70 mesh (opening diameter 0.212 mm) to 10 mesh (opening diameter). Glass fiber content of 45% by weight (22.3% by volume) by a papermaking method using polypropylene resin powder classified to a diameter of 1.7 mm)
A non-woven material having a composition of 55% by weight (77.7% by volume) of polypropylene resin and a basis weight of 1100 g / m ² was produced.

The nonwoven material was cut into pieces of 600 × 2000 mm and laminated on six sheets, and one polypropylene resin film (thickness: 0.5 mm) was laminated on one side thereof. Further, a stainless steel end plate having a smooth surface as a plate-like body was superposed on both surfaces of this laminated body, and the plate material for a mold of the present invention was molded by the molding method shown in FIG. The laminated body was inserted into a heating press platen whose temperature was set to 210 ° C., and preheated under a pressure of 2 kgf / cm ² for about 7 minutes until the temperature of the central part of the nonwoven material increased to 190 ° C. or higher. . At this temperature, the polypropylene resin was sufficiently molten. Next, pressure 5kgf / cm
^2, 1 minute pressurized to further insert the stack to the cooling press platen, the clearance press platen set by a spacer, for about 5 minutes at a pressure 5 kgf / cm ^2, pressure, and cooling molding,
After molding, the end plate was removed to obtain a plate material for a frame having a plate thickness of 12 mm.

After heating and pressurizing, the laminate immediately expanded due to the springback of the reinforcing fibers in a short time when it was moved from the heating plate to the cooling plate. In addition, it was confirmed that the nonwoven material after heating and pressing was in close contact with the end plate very firmly, and that the surface of the non-woven material was expanded while being constrained by the surface of the end plate.

A stable resin-rich layer was formed on the surface of the form plate material on which the polypropylene resin film was laminated, the glass fiber was not exposed, and the smooth surface of the end plate was transferred to give a good appearance. On the surface on which the resin film was not laminated, a resin-rich layer was formed in the same manner, and the smooth surface of the mirror plate was transferred, showing the appearance, but a slight exposure of glass fiber was observed.

Further, by observation with an optical microscope and a scanning electron microscope, it was confirmed that the crossing portions of the glass fibers in the fiber reinforced thermoplastic resin layer were efficiently adhered by the polypropylene resin and uniform expansion was carried out. The thickness of the polypropylene resin layer on which the film is laminated is about 0.3 mm,
It was confirmed that the fiber-reinforced thermoplastic resin layer inside was well bonded. The reason why the thickness of the resin layer is smaller than the thickness of the laminated film is that the molten resin is absorbed inside the bubbles of the expanded fiber-reinforced thermoplastic resin layer.

A width of 70 mm and a length of 200
mm test pieces were sampled and a 3-point bending test with a span of 150 mm was performed. Further, using this form plate material, a concrete wall construction experiment was conducted by a conventional construction method of a wood form plate material. The contact surface with concrete is a resin-rich surface on which polypropylene resin films are laminated, and the thickness of the constructed wall is 150 mm and the height is 3.5 m. The results are shown in Table 1.

Example 2 The nonwoven material of Example 1 was cut into pieces of 600 × 2000 mm and 6
One sheet was laminated, and one composite film composed of a talc-containing polypropylene resin film and a polypropylene resin film was laminated on both sides so that the polypropylene resin film side was on the outside. The composite film was composed of a polypropylene resin film (thickness: 0.3 mm) and a polypropylene resin film (thickness: 0.1 mm) to which 40% by weight of talc, which is a fine-particle inorganic filler having a diameter of 2 μm, was added. A stainless steel end plate as a plate-like body was superposed on both sides of this laminate, and a plate material for a frame having a plate thickness of 12 mm was formed in the same manner as in Example 1.

On the surface of the form plate material, a stable resin-rich layer was formed, the glass fiber was not exposed, and the smooth surface of the end plate was transferred to give a good appearance. Further, it was confirmed by observation with an optical microscope and a scanning electron microscope that the crossing portions of the glass fibers in the fiber-reinforced thermoplastic resin layer were efficiently adhered by the polypropylene resin and uniform expansion was performed. It was confirmed that the outermost surface layer of the composite resin layer was a polypropylene resin layer with a thickness of 0.1 mm, and then the talc-containing polypropylene resin layer with a thickness of 0.3 mm was present, similar to the laminated composite film. Was done. It was also confirmed that this composite resin layer and the fiber-reinforced thermoplastic resin layer inside were well bonded. The thermoplastic resin to which the inorganic filler is added has an increased melt viscosity and is suppressed from being absorbed into the air bubbles in the expanded fiber-reinforced thermoplastic resin layer, which is useful for forming a stable resin-rich layer.

A width of 70 mm and a length of 200 from this form plate material.
mm test pieces were sampled and a 3-point bending test with a span of 150 mm was performed. Furthermore, using this plate material for formwork, Example 1
A concrete construction experiment was conducted in the same manner as in. The results are shown in Table 1.
It was shown to.

Example 3 A laminate of the nonwoven material and the composite film of Example 2 was provided with a stainless steel end plate as a plate on one side and a steel plate with a grain pattern on the other side. Overlap,
In the same manner as in Example 1, a plate material having a plate thickness of 12 mm was molded.
The grained surface of the grain pattern had a maximum unevenness depth of 3 mm.

A stable resin-rich layer is formed on the surface of the form plate material, the glass fibers are not exposed, the smooth surface is transferred on the surface of the end plate side, and the wood pattern is formed on the surface of the textured plate body. It was transferred and had a good appearance. Further, it was confirmed by observation with an optical microscope and a scanning electron microscope that the crossing portions of the glass fibers in the fiber-reinforced thermoplastic resin layer were efficiently adhered by the polypropylene resin and uniform expansion was performed. The form of the composite resin layer on the surface was the same as in Example 2, and it was confirmed that this composite resin layer and the fiber-reinforced thermoplastic resin layer inside were well bonded.

From this plate material for formwork, width 70 mm, length 200
mm test pieces were sampled and a 3-point bending test with a span of 150 mm was performed. Furthermore, using this plate material for formwork, Example 1
A concrete construction experiment was conducted in the same manner as in. The experiment was carried out by using the surface on which the grain pattern was transferred as the contact surface with the concrete. The results are shown in Table 1.

Comparative Example 1 The nonwoven material of Example 1 was cut into pieces of 600 × 2000 mm and cut into 7 pieces.
Sheets were laminated, and stainless steel end plates as plate-like bodies were superposed on both sides thereof to form a plate-like molded product with voids removed. The laminated body was inserted into a heating press platen whose temperature was set to 210 ° C., and preheated under a pressure of 2 kgf / cm ² for about 7 minutes until the temperature of the central part of the nonwoven material increased to 190 ° C. or higher. . Then, pressurize at a pressure of 5 kgf / cm ² for 1 minute, and then insert the laminated body into a cooling press machine, and press at a pressure of 5 kgf / cm ^2.
A plate-shaped molded product was molded by pressing and cooling for about 5 minutes. In this case, the clearance of the press platen was not set, and the non-woven material was cooled and molded in the state of being directly pressed, as in the heating and pressing. After cooling, the end plate is removed and the plate thickness is 6.1.
A plate-shaped molded product of mm was obtained.

The surface of the plate-shaped molded product is resin-rich and wrinkles,
The reinforcing fibers were barely exposed and had a good appearance. Further, by observation with an optical microscope and a scanning electron microscope, it was confirmed that the reinforcing fibers inside the molded product were uniformly dispersed, and the thermoplastic resin was sufficiently impregnated between them. A test piece having a width of 70 mm and a length of 200 mm was sampled from this molded product and subjected to a three-point bending test with a span of 150 mm. further,
Using this molded product, a concrete construction experiment was conducted in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 Using the plate-shaped molded product molded in Comparative Example 1 as a molding material, a porous molded product was molded by the conventional method shown in FIG.
Surface temperature of the molding material is 210 ° C in a far infrared heating furnace.
It heated for about 7 minutes until it heated up. At this time, the molding material was greatly expanded in the vicinity of the surface, and the inside was not sufficiently heated. Further, it was confirmed that unevenness was generated on the surface portion and the glass fiber was exposed by spring back. Insert the heated molding material into the cooling press machine,
Set the clearance of the press board with a spacer,
About 5 minutes at a pressure of 5 kgf / cm ^2, pressure, and cooling molding, thickness 1
A 2 mm porous molded product was obtained.

Since the appearance of this porous molded article inherits that of the heated molding material, wrinkles due to surface irregularities and deterioration of the external appearance due to the exposure of the reinforcing fibers occur. Further, by observation with an optical microscope and a scanning electron microscope, it was confirmed that the inside of the porous molded product expanded greatly near the surface and the central part did not expand much like the original molding material. This center layer is approximately 50% of the initial thickness of the molding material.
And had a thickness of 3.2 mm. A test piece with a width of 70 mm and a length of 200 mm was sampled from this porous molded product and span 1
A 50 mm 3-point bending test was performed. Further, using this porous molded article, a concrete construction experiment was conducted in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 A wood form board material which has been conventionally used was evaluated. The plate material for wood formwork has a thickness of 12 mm and a basis weight of 7700 g / m.
^{In 2} , urethane coating was applied on one side. A test piece having a width of 70 mm and a length of 200 mm was sampled from the wood form plate material and subjected to a three-point bending test with a span of 150 mm. further,
A concrete construction experiment was conducted in the same manner as in Example 1. The experiment was carried out with the urethane coated surface as the contact surface with concrete. The results are shown in Table 1.

The mold plate materials of the examples showed good mechanical properties because the fiber-reinforced thermoplastic resin layer was subjected to uniform expansion and the glass fibers were efficiently bonded with the polypropylene resin. The strength and elastic modulus per area are comparative example 1.
Although it is lower than the non-expanded molded product, the bending strength (bending load), bending rigidity (elastic gradient) of the product
Has been improved. The bending gradient is a load when the bending amount of the test piece is 2.5 mm in the three-point bending test, and is an index of the rigidity of the form plate material. The example and the comparative example 1 have almost the same basis weight (weight per unit area), but the plate thickness of the example is about twice as large as that of the comparative example 1 due to the expansion of the fiber reinforced thermoplastic resin layer. It's getting thicker. This result is because the bending strength is proportional to the square of the product plate thickness, and the bending rigidity is proportional to the cube of the plate thickness, and it was confirmed that the rigidity is remarkably improved.

It was confirmed that the mechanical properties of Comparative Example 2 were lower than those of Examples and Comparative Example 1. In the porous molded article of Comparative Example 2, the expansion in the vicinity of the surface was very large, and the central portion showed a structure in which it was hardly expanded. Therefore, when the product is bent, the surface portion to which a tensile or compressive load is applied has a mechanically weak structure and mechanical properties are deteriorated.

In a concrete construction experiment using the formwork plate material of the example, good results were obtained. Due to the improved mechanical properties, the formwork plate material does not sag under heavy load during concrete construction, and the smooth surface or makeup pattern of the formwork plate material is transferred to the construction surface, giving a good appearance. Was given. Further, the releasability of concrete was also good.

In the case of Comparative Example 1, due to insufficient rigidity, the mold was bent under a heavy load during concrete construction, and wavy unevenness was generated on the construction surface. The releasability of concrete is
Although it was almost good, the concrete adhered to the glass fiber exposed on the surface though it was very slight.

In the case of Comparative Example 2, the properties of the concrete construction surface and the releasability were poor. Since concrete penetrated into the air bubbles inside the porous molded product and glass fiber adhered, a large amount of glass fiber and polypropylene resin remained on the surface of the concrete construction. In addition, due to insufficient rigidity, the formwork was bent under heavy load during concrete construction, and waviness was generated on the construction surface.

The formwork plate materials of the examples show the same level of weight reduction and concrete construction performance as those of the conventional wood formwork plate materials of Comparative Example 3 by improving the mechanical properties and appearance. Was confirmed. The transfer performance of the makeup pattern of Example 3 leads to the use as a makeup form.

[0055]

[Table 1]

[0056]

EFFECT OF THE INVENTION The plate material for formwork of the present invention is excellent in mechanical properties and appearance, and exhibits the same level of weight reduction and concrete construction performance as the plate material for wood formwork used conventionally.
Further, since the allowable range of product thickness is widened as compared with the conventional porous molded product, it becomes an excellent wood substitute and can be widely applied to industrial materials.

[Brief description of drawings]

FIG. 1 is a schematic view showing a form plate material of the present invention.

FIG. 2 is a schematic view showing an example of a method of forming a plate material for a mold of the present invention.

FIG. 3 is a schematic view showing an example of a conventional method for molding a porous molded article.

[Explanation of symbols]

1 Plate Material for Formwork of the Present Invention 2 Fiber Reinforced Thermoplastic Resin Layer 3 Thermoplastic Resin Layer 4 Reinforcing Fiber 5 Thermoplastic Resin 6 Nonwoven Material 7 Thermoplastic Resin Film 8 Plate-like Body 9 Heating Press Board 10 Thermoplastic Resin Melts The non-woven material which is pressed in the state 11 The non-woven material which is uniformly expanded by the springback of the reinforcing fiber 12 The cooling press plate 13 The sheet-shaped forming material 14 The far infrared heating furnace 15 The expanded layer 16 The layer which is hardly expanded 17 Unevenness of sheet surface 18 Exposure of reinforcing fiber by springback 19 Porous molded product 20 Wrinkled surface of molded product

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[Procedure amendment]

[Submission date] February 22, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

In the molding method of FIG. 2, the heating, pressurizing step and the pressurizing, cooling step are carried out by separate dedicated press machines, but the heating, pressurizing, depressurizing and cooling molding are carried out by one press machine. You can also In addition, preheating the non-woven material for the purpose of shortening the heating time of the non-woven material on the hot press machine is preferable because it shortens the molding cycle. For the preheating of the non-woven material, there is used a method of passing hot air for heating in a short time by utilizing air permeability of the non-woven material, or heating by an oven.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

When a sheet-shaped molding material obtained by heating, pressurizing and cooling the non-woven material is used instead of the non-woven material,
Similarly, expansion due to springback of the reinforcing fibers occurs, and the plate material for a mold of the present invention can be obtained. However, in this case, the entire process becomes long due to the forming process of the sheet-shaped forming material, which is not efficient. Since the form plate material formed by this method has an unstable peripheral shape, the product shown in FIG. 1 is actually obtained and used by trimming the periphery of the formed product.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

It is also possible to use a thermoplastic resin film to which an inorganic filler is added. As the inorganic filler to be added, particulate fillers such as calcium carbonate and talc, flaky fillers such as mica, fibrous fillers such as chopped glass fibers and rock wool fibers are used. The inorganic filler is preferably surface-treated with a silane coupling agent or the like in order to improve the adhesiveness with the thermoplastic resin. The inorganic filler is appropriately selected according to the application. Further, a mixture of two or more kinds of the above inorganic fillers may be added. The amount of the inorganic filler added is 3% by volume or more for the purpose of improving the melt viscosity of the thermoplastic resin and strengthening the surface layer portion, and 30% by volume that enables stable film formation.
Below. However, since the inorganic filler has a property of easily adhering to concrete, a thermoplastic resin film can be laminated on the outermost surface in order to maintain releasability from concrete. The thermoplastic resin film containing an inorganic filler is in the range of 0.1 to 2 mm, and the thickness of the thermoplastic resin film is in the range of 0.01 to 1 mm, and is appropriately selected depending on the application.

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Kimura 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Petrochemical Co., Ltd. Yokkaichi Research Institute

Claims (4)

[Claims] 1. A porous fiber-reinforced thermoplastic resin layer made of a non-woven material produced by a papermaking method, and a thermoplastic resin layer having a thickness of 0.2 to 2 mm laminated on one side or both sides thereof,
The reinforcing fibers and bubbles of the fiber-reinforced thermoplastic resin layer are covered by the laminated surface of the thermoplastic resin layer, the overall apparent density is 0.3 to 1 g / cm ³ , and the basis weight is 4500 g / m 2. ²
The above plate materials for concrete formwork. 2. The plate material for concrete formwork according to claim 1, wherein the reinforcing fiber content of the fiber-reinforced thermoplastic resin layer is 10% by volume or more. 3. The thermoplastic resin layer comprises an inorganic filler-containing thermoplastic resin layer and a thickness of 0.01, which is arranged further outside.
The plate material for concrete formwork according to claim 1 or 2, comprising a thermoplastic resin layer having a thickness of 1 mm. 4. The plate material for concrete formwork according to claim 1, wherein the surface of one side or both sides of the surface is provided with a concavo-convex process (texture process) of a decorative pattern.