JP2000218741A - Composite material and synthetic sleeper comprising the material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance strength and rigidity, improve processability, and at the same time eliminate generation of incineration ash by forming a main body part comprising a stretched polyolefin resin sheet and a thermoplastic resin sheet alternately laminated on each other and a core layer consisting of a nonwoven fabric sheet laminated along the thermoplastic resin sheet. SOLUTION: The composite material 1a comprises a foamed polyurethane resin layer 2 which is foamed heat-curable resin layer and a core layer 3a laminated on the upper and lower face of the resin layer 2. The core layer 3a is formed of a core layer main body part 31 and a nonwoven fabric sheet 32. The core layer main body part 31 is manufactured by alternately superimposing a stretched polyolefin resin sheet 31a and a thermoplastic resin sheet 31b having a lower melting temperature than the melting point of the resin sheet 31a, and it is pressure-bonded at temperature higher than melting temperature to form a laminate. In this case, the thermoplastic resin sheet 31b is exposed on one face and the polyolefin resin sheet 31a is exposed on the other face. In addition, the nonwoven fabric sheet 32 is previously melt-bonded to the exposed thermoplastic resin sheet 31b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material and a composite sleeper made of the composite material.

[0002]

2. Description of the Related Art Conventionally, wood or concrete has been used as a material for sleepers or civil engineering construction.
Corrosion and damage are severe, and there is a problem in durability such as deterioration of physical properties due to water absorption. In the case of concrete, there is a problem that strength and durability are excellent but weight is very heavy.

In order to address the problems of wood and concrete, synthetic wood has been developed in which a resin foam is filled with long glass fibers aligned in one direction and the resin foam is reinforced. However, although such synthetic wood is excellent in physical properties such as strength, it contains a large amount of glass fiber, and when incinerated, a large amount of glass adheres to the walls of the incinerator and damages the furnace. It is currently being landfilled. In addition, when cutting, a large amount of glass powder is scattered and there is a problem in the work environment.Moreover, some glass fibers are exposed on the surface during use for a long time, so it is used for touching the human body If so, it may cause discomfort.

Accordingly, a phenolic resin foam obtained by injecting and foaming a phenolic resin into a cylindrical molded product obtained by press-molding a polypropylene prepreg as disclosed in JP-A-7-957. Artificial wood has been proposed which does not use glass fibers whose body is covered by a layer of polypropylene around its circumference.

[0005]

However, the above-mentioned artificial wood certainly exhibits the same performance as natural wood in terms of processability, but is inferior to the synthetic wood in physical properties such as strength and nail holding power. It is. Therefore, it cannot be used for applications requiring high strength such as railroad sleepers and civil engineering building materials.

Accordingly, the present invention has been made in view of the above-mentioned circumstances, and has high strength and high rigidity, and has the same workability as wood for cutting and nailing, and has a glass residue at the time of incineration. It is an object of the present invention to provide a composite material that does not generate incineration ash such as the above and has no problem in working environment and a synthetic sleeper using the composite material.

[0007]

In order to achieve the above object, a composite material according to claim 1 of the present invention (hereinafter, referred to as a "composite material of claim 1") is provided with a stretched polyolefin resin sheet (hereinafter referred to as "composite material"). A) and a thermoplastic resin sheet (B) having a melting temperature lower than the melting point of the stretched polyolefin resin sheet (A) and having an adhesive property with the stretched polyolefin resin sheet (A). And a nonwoven fabric laminated along the thermoplastic resin sheet (B) on the surface of the core layer main body portion, in which the thermoplastic resin sheet (B) is alternately laminated on the surface of the core layer. A structure having at least one core layer made of a sheet (C), and a thermosetting resin layer made of a thermosetting resin (D) laminated on the surface of the nonwoven fabric sheet (C) of the core layer; did.

[0008] The composite material according to claim 2 of the present invention (hereinafter referred to as "the composite material of claim 2") comprises a stretched polyolefin resin sheet (A) and a melting point of the stretched polyolefin resin sheet (A). A thermoplastic resin sheet (B) having a lower melting temperature and adhesiveness to the stretched polyolefin-based resin sheet (A) so that the thermoplastic resin sheet (B) is positioned on both surfaces of the thermoplastic resin sheet (B). A core material layer composed of a core material layer body portion alternately laminated and a nonwoven fabric sheet (C) laminated along the thermoplastic resin sheet (B) on the surface of the core material layer body portion has a substantially spiral cross section. A thermosetting resin layer is provided in a gap between a portion wound inside and a portion wound outside of the core layer, and a core layer is provided. Part wound inside and part wound outside Portion and has a configuration that is secured through the thermosetting resin layer.

The composite material according to claim 3 of the present invention (hereinafter referred to as “composite material according to claim 3”) is a composite material according to claim 1 or 2, wherein the filler is contained in the thermosetting resin. Are mixed.

The composite material according to claim 4 of the present invention (hereinafter referred to as “composite material of claim 4”) is a composite material according to any one of claims 1 to 3, wherein the thermosetting resin is It was configured to be a foamable polyurethane resin. A composite sleeper according to a fifth aspect of the present invention is formed from the composite material according to any one of the first to fourth aspects.

In the present invention, the melting point means the temperature Tm at which the crystalline structure of the crystalline thermoplastic resin completely disappears and becomes a fluidized state. Further, the melting temperature means the minimum temperature at which the thermoplastic resin is plasticized and flows, and plastic processing is possible.Specifically, the stretched thermoplastic resin has a tension for stretching and holding. It refers to the lowest temperature at which melting and processing in the applied state are possible. The stretched polyolefin-based resin sheet (A) refers to a sheet composed of a material mainly composed of a polyolefin-based resin stretched at least in the longitudinal direction.

The polyolefin resin to be used as the above-mentioned stretched polyolefin resin sheet (A) is not particularly limited.
Linear low-density polyethylene, high-density polyethylene, homopolypropylene, propylene random copolymer, propylene block copolymer, poly (4-methyl-pentene-
1) and the like. Among these polyolefin-based resins, polyethylene having a high elastic modulus after stretching, particularly high-density polyethylene having high crystallinity, is preferably used. The polyolefin-based resin may further contain a nucleating agent, a cross-linking agent, a cross-linking aid, a filler, a pigment, a different kind of polyolefin, a low-molecular-weight polyolefin wax, or the like, if necessary.

The nucleating agent is added for the purpose of improving the crystallinity, and examples thereof include calcium carbonate and titanium oxide. The cross-linking agent and the cross-linking assistant are added for the purpose of partially cross-linking the molecular chain of the polyolefin-based resin and improving the heat resistance and creep performance of the stretched polyolefin-based resin sheet (A). As a crosslinking agent, for example, benzophenone, thioxanthone,
Examples include a photopolymerization initiator such as acetophenone, and examples of a crosslinking assistant include polyfunctional monomers such as triallyl cyanurate, trimethylolpropane triacrylate, and diallyl phthalate.

In order to partially cross-link the molecular chain of the polyolefin resin, a cross-linking means using electron beam irradiation or ultraviolet irradiation may be employed instead of using a cross-linking agent. In the crosslinking means by electron beam irradiation or ultraviolet irradiation, the above-mentioned crosslinking agent or crosslinking assistant is added to the polyolefin resin, preferably 1 Mrad or more and 20 Mrad or less, more preferably 3 Mrad or less.
rad or 10Mrad following electron beam, or, preferably 50 mW / cm ² or more 800 mW / cm ² or less, more preferably a method can be mentioned that irradiates 100 mW / cm ² or more 500 mW / cm ² or less of ultraviolet light.

[0015] Such a crosslinking step may be performed simultaneously with or subsequent to the stretching step described below. The stretched polyolefin-based resin sheet (A) is obtained by stretching a sheet-shaped polyolefin-based resin sheet. The means for producing the polyolefin-based resin sheet is not particularly limited, and examples thereof include extrusion molding by a T-die method and roll molding by a calender method.

The means for continuously stretching the polyolefin-based resin sheet is not particularly limited.
For example, a method of stretching a heated polyolefin-based resin sheet between rolls having different speeds, sandwiching the heated polyolefin-based resin sheet between rolls rotating in different directions, and elongating in the longitudinal direction while reducing the thickness. So-called rolling method.

The stretching may be performed by performing any one of the above-described methods a single time, or may be repeatedly performed two or more times in a stepwise manner. When the stretching step is performed twice or more, a plurality of stretching methods may be combined. In particular,
When stretching a relatively thick polyolefin-based resin sheet, it is preferable to perform the above-mentioned rolling method once, perform rolling to a predetermined thickness, and then perform further stretching.

The thickness of the polyolefin-based resin sheet (stretched raw material) before stretching is determined by the use of the obtained composite material, the stretching ratio, and the like, and is not particularly limited. It is 0.5 mm or more and 4 mm or less. If the thickness is less than 0.5 mm, the thickness of the stretched polyolefin-based resin sheet (A) becomes too thin, so that the handling property in the laminating work in the next step is reduced and the work becomes difficult. Since it becomes too large, not only the stretching device becomes unnecessarily large, but also the stretching operation may become difficult.

The thickness of the stretched polyolefin resin sheet (A) obtained from such a stretched raw fabric is about 50 μm or more and 300 μm or less. The width of the stretched polyolefin-based resin sheet (A) is appropriately selected depending on the shape and dimensions of the obtained composite material, and is not particularly limited. For example, when a stretched polyolefin resin sheet (A) having a relatively small width is used, a wide sheet may be slit.

The stretching ratio of the stretched polyolefin-based resin sheet (A) is determined by the properties of the polyolefin-based resin used, and is not particularly limited, but is preferably in the longitudinal direction. The stretching ratio is preferably at least 10 times or more, more preferably 20 times or more. If the stretching ratio in the longitudinal direction of the stretched polyolefin-based resin sheet (A) is less than 10 times, it may be difficult to obtain necessary strength and elastic modulus.
Further, when stretching in the width direction is performed, stretching in the longitudinal direction is suppressed, and stretching in the longitudinal direction by 10 times or more may be difficult.

The stretched polyolefin resin sheet (A) may be subjected to a surface treatment by a physical or chemical means, if necessary, for the purpose of improving the adhesiveness. As the surface treatment, for example, a physical surface treatment method of forming fine irregularities on the surface of the obtained stretched polyolefin-based resin sheet (A) by embossing means such as sandblasting or local heating means for the surface portion is used. It is preferably used for reasons such as ease of operation.

The degree of fine irregularities formed on the surface of the stretched polyolefin resin sheet (A) is, for example, as follows:
It can be expressed by the center line average roughness (Ra) according to JIS B 0601, and preferably Ra ≧ 0.5 μm. R
If a is less than 0.5 μm, the surface treatment effect may not be sufficiently obtained.

In the present invention, the thermoplastic resin sheet (B)
Has a melting temperature lower than the melting point of the above-mentioned stretched polyolefin-based resin sheet (A) and has adhesiveness with the stretched polyolefin-based resin sheet (A). At a temperature lower than the melting point of the base resin sheet (A) and at a temperature equal to or higher than the melting temperature of the thermoplastic resin sheet, it refers to an adhesive performance of such a degree that the laminated sheet obtained by pressing is generally adhered without peeling between layers. If there is no practical problem as a laminate even if there is a slight unbonded portion due to the entrapment of air bubbles, etc., these thermoplastic resin sheets are also used as thermoplastic resins having adhesiveness with the above-mentioned stretched polyolefin resin sheet (A). It can be included in the sheet (B). Of course, it is preferable that the adhesiveness be as high as possible.

The thermoplastic resin constituting the thermoplastic resin sheet (B) is not particularly limited as long as it has adhesiveness to the stretched polyolefin resin sheet (A). A polyolefin-based resin used for a stretched raw sheet of the resin sheet (A), a copolymer comprising a main chain olefin mainly composed of olefins and another comonomer, an acid-modified polyolefin,
Olefin-based elastomers and the like can be mentioned.

The thickness of the thermoplastic resin sheet (B) is determined by the use of the composite material to be obtained, and is not particularly limited.
μm or less, more preferably 50 μm or less. 100
When the thickness exceeds μm, the proportion of the thermoplastic resin sheet (B) relatively increases, and the mechanical strength such as the tensile strength and rigidity of the composite material may be reduced. The means for producing the thermoplastic resin sheet (B) is not particularly limited, but examples include extrusion molding by a T-die method or an inflation method.

Further, the thermoplastic resin sheet (B) has a T
It may be slightly stretched by the tension of the take-up roll in the die method or the blow-up ratio in the inflation method. The core material layer main body is composed of a stretched polyolefin resin sheet (A) and a thermoplastic resin sheet (B).
Are alternately laminated, and the thickness is determined by the thickness of each sheet, and can be arbitrarily selected within the above-mentioned thickness range of each sheet.

Although the core material layer main body is not particularly limited in advance, a laminated sheet in which a stretched polyolefin resin sheet (A) and a thermoplastic resin sheet (B) are alternately laminated can be used. The method for producing the laminated sheet serving as the core material layer main body is not particularly limited. For example, a stretched polyolefin resin sheet (A) and a thermoplastic resin sheet are alternately laminated and arranged. Into a heating furnace controlled at a temperature lower than the melting point of the stretched polyolefin resin sheet (A) and equal to or higher than the melting temperature of the thermoplastic sheet, and passed between pressing rolls installed in the heating furnace, thereby drawing the stretched polyolefin resin sheet. A method of fusing and laminating the resin sheet (A) and the thermoplastic resin sheet (B) and the like are exemplified.

In the present invention, the nonwoven fabric sheet (C) is
Laminated on the thermoplastic resin sheet (B) on the surface of the core material layer main body at a temperature higher than the melting temperature of the thermoplastic resin sheet (B), thereby increasing the physical bonding effect between the core material layer main body and the thermosetting resin layer. It is not particularly limited as long as it exerts this effect. The material of the nonwoven fabric sheet (C) is not particularly limited, and examples thereof include organic fibers, inorganic fibers, and synthetic resins, and also include paper.

The thickness of the nonwoven fabric sheet (C) is determined by the use of the obtained composite material and the like, and is not particularly limited, but is preferably 1 mm or less.
More preferably, it is 0.5 mm or less. When the thickness exceeds 1 mm, the proportion of the nonwoven fabric sheet (C) relatively increases, and the mechanical strength such as the tensile strength and rigidity of the composite material may decrease. As a method of laminating the nonwoven fabric sheet (C) on the core material layer main body, a laminated sheet to be the core material layer main body is obtained, and then the thermoplastic resin sheet (B) on the surface of the laminated sheet is melted and laminated. And a method of producing a laminated sheet to be a core material layer main body portion and simultaneously laminating a nonwoven fabric sheet (C) to form a reinforced laminated sheet to be a core material layer. .

[0030] In the present invention, the thermosetting resin (D) is not particularly limited.
Phenol resins, unsaturated polyester resins, epoxy resins, and the like. In addition, if these resins are foamed by a known method, it is possible to reduce the weight of the composite material and to provide workability equivalent to that of wood.

In the composite material according to the second aspect, the core material layer is formed in a spiral shape or an annual ring shape, but the distribution and the like thereof are not particularly limited, and depend on the use of the obtained composite material. It is appropriately selected. For example, when a bending load mainly acts on the composite material, the load burden is small near the center of the composite material. It is also possible to arrange the material layers intensively. The surface layer of the composite material may be a reinforced laminated sheet serving as a core material layer or a thermosetting resin.

In the method for producing the composite material according to the second aspect, the reinforced laminated sheet serving as the core material layer is previously wound around a rod-shaped core, and the wound state is held by a jig or the like.
It is put into the mold, then the jig is removed, the bar is removed, and the thermosetting resin is placed in the gap between the part wound inside and the part wound outside of the wound reinforced laminated sheet. And the mold may be closed and molded. Alternatively, the reinforced laminated sheet to which the thermosetting resin is previously adhered may be wound into the mold in the same manner as described above, and molded.

In the composite material according to the third aspect, the filler used is not particularly limited, and examples thereof include inorganic powder, sludge dry powder, and fiber-reinforced resin pulverized material. These fillers may be used alone or as a mixture of two or more. As the inorganic powder, rock powder, glass powder, calcium silicate, cement concrete crushed material, amorphous particles such as silica sand, sericite, inorganic short fiber powder such as wollastonite, vermiculite, Examples include inorganic powder having bubbles such as pearlite, expanded shale and hollow powder of fly ash, and inorganic powder having a relatively small particle size such as calcium carbonate and fly ash.

As the sludge dry powder, there is a constant temperature dry solid generated from a sludge treatment plant. As the above-mentioned pulverized fiber-reinforced resin, fiber-reinforced plastic (FR
P) Pulverized materials, fiber-reinforced hard foamed urethane pulverized materials, and the like.

In the composite material according to the third aspect, the mixing ratio of the filler to the thermosetting resin depends on the use of the obtained composite material,
It is appropriately selected depending on the type of the filler used, the type of the thermosetting resin, and the like, and is not particularly limited. However, when the mixing ratio of the filler is more than 50% by volume, 9
A range of 5% by volume or less is preferable. Filling ratio is 5
When the content is 0% by volume or less, since the thermosetting resin layer exists between the fillers and the fillers are less likely to come into direct contact with each other, the compressive strength and the holding power of the driven nail are reduced. If the content is insufficient, and if the content exceeds 95% by volume, the material becomes brittle, and the bending strength and the nailing property decrease.

The method of mixing the filler with the thermosetting resin is not particularly limited. For example, a well-known mixing device such as a batch mixer, a high-speed continuous mixer, and a kneader may be used. Can be used for mixing.

[0037]

Embodiments of the present invention will be described below in detail. FIG. 1 shows a first embodiment of the composite material according to the present invention.

As shown in FIG. 1, this composite material 1a
Foamed polyurethane resin layer 2 as foamed thermosetting resin layer
The core material layer 3a is laminated on the upper and lower surfaces of the substrate. That is, as shown in FIG. 2, the core material layer 3 a
And a nonwoven fabric sheet (C) 32.

The core material layer main body 31 is not shown,
A stretched polyolefin-based resin sheet (A) 31a and a thermoplastic resin having a melting temperature lower than the melting point of the stretched polyolefin-based resin sheet (A) 31a and having adhesiveness to the stretched polyolefin-based resin sheet (A) 31a While the sheet (B) 31b is alternately stacked,
Laminated by thermocompression bonding at a temperature lower than the melting point of the stretched polyolefin resin sheet (A) 31a and higher than the melting temperature of the thermoplastic resin sheet (B) 31b,
The thermoplastic resin sheet (B) 31b is exposed on one side,
On the other side, stretched polyolefin resin sheet (A) 31
a is exposed.

The nonwoven fabric sheet (C) 32 is a thermoplastic resin sheet (B) 3 exposed on one surface of the core material layer main body 31.
1b is fused in advance.

The two core layers 3 a are arranged so that the nonwoven fabric sheet (C) 32 faces each other, and are bonded and integrated via the foamed polyurethane resin layer 2. In the foamed polyurethane resin layer 2, a filler is mixed in the foamed polyurethane resin.

The method of manufacturing the composite material 1a is as follows. First, a laminated sheet which becomes the core material layer main body 31 by laminating the stretched polyolefin resin sheet (A) 31a and the thermoplastic resin sheet (B) 31b is prepared. Then, a nonwoven fabric sheet (C) 32 is laminated along the exposed surface of the thermoplastic resin sheet (B) 31b of the laminated sheet to form a reinforced laminated sheet that becomes the core material layer 3a. The nonwoven fabric sheet (C) is placed in the lower mold 42 of the mold 4 as shown in FIG.
After laying with the 32 side up, the foamed polyurethane resin liquid is evenly placed on the nonwoven fabric sheet (C) 32.

Next, the other reinforced laminated sheet is stretched in the stretching direction of the stretched polyolefin sheet (A) 31a, and the lower reinforced laminated sheet is stretched in the stretched polyolefin sheet (A) 3a.
1a, and the nonwoven fabric sheet (C) 32 is placed on the foamed polyurethane resin liquid with the nonwoven fabric sheet (C) 32 side facing the foamed polyurethane resin liquid.
Is closed until the spacer 43 hits the upper edge of the lower mold 42. Then, the foamed polyurethane resin liquid is heated and foamed and hardened in the mold 4.

As described above, in the composite material 1a, the laminated sheet to be the core material layer main body 31 is thermocompression-bonded at a temperature lower than the melting point of the stretched polyolefin resin sheet (A) 31a at the time of lamination. Since the orientation of the stretched polyolefin resin sheet (A) 31a is firmly laminated with the thermoplastic resin sheet (B) 31b without relaxing the orientation, the sheet has high rigidity and high strength. Since the nonwoven fabric sheet (C) 32 is interposed between the core material layer main body 31 and the foamed polyurethane resin layer 2, the core material layer main body 31 and the foamed polyurethane resin layer 2 are strongly bonded to each other. It has high strength, high strength and high rigidity. Further, since glass fibers are not usually used, they are lightweight and there is no fear that glass residues remain during incineration.

Further, since the filler is mixed in the foamed polyurethane resin layer 2, the compression strength is excellent. Moreover, since a foamed polyurethane resin is used as the thermosetting resin, workability such as cutting and nailing is the same as that of wood, and the holding power of the driven nail is extremely excellent. Also, it has excellent adhesiveness with the filler.

FIG. 4 shows a composite material according to a second embodiment of the present invention. As shown in FIG. 4, the composite material 1b has several layers in which a thermoplastic resin sheet (B) is disposed on both surfaces of a core material layer main body (not shown) and a nonwoven fabric sheet (C) is laminated on both surfaces. Except that the core material layer 3b and the thermosetting resin layer 2 are alternately laminated.
Is similar to

FIG. 5 shows a composite material according to a third embodiment of the present invention. As shown in FIG. 5, the composite material 1c includes a cylindrical core material layer 3c and a thermosetting resin layer 2 filled in the cylindrical core material layer 3c.

The core material layer 3c is made of the composite material 1a.
Is formed in a state where the reinforced laminated sheet used in the above is bent into a cylindrical shape such that the nonwoven fabric sheet (C) side is inside.

FIG. 6 shows a fourth embodiment of the composite material according to the present invention. As shown in FIG. 6, in the composite material 1d, the core material layer 3d has a substantially E-shaped cross section, and the thermosetting resin layer 2 is provided so as to surround the core material layer 3d.

That is, although not shown, the core material layer 3d is formed of a thermoplastic resin sheet (B)
The nonwoven fabric sheet (C) is laminated along the surface of the core layer main body in which the stretched polyolefin-based resin sheet (A) and the thermoplastic resin sheet (B) are alternately laminated so that is arranged.

FIG. 7 shows a composite material according to a fifth embodiment of the present invention. As shown in FIG. 7, the composite material 1e is the same as the composite material 1d except that the core material layer 3e has a ladder shape instead of an E-shaped cross section.

FIG. 8 shows a composite material according to a sixth embodiment of the present invention. As shown in FIG. 8, the composite material 1f includes a plurality of core layers 3f, and the core layer 3f has a rectangular cross section instead of an E-shaped cross section, and the inside of the square is hollow. Other than the above, it is the same as the composite material 1d.

FIG. 9 shows a composite material according to a first embodiment of the present invention. As shown in FIG. 9, in the composite material 1j, the core material layer 3j is spirally wound, and a gap is formed between a portion wound inside the core material layer 3j and a portion wound outside. A thermosetting resin layer 2 is provided, and a portion wound inside and a portion wound outside the core material layer 3j are fixed via the thermosetting resin layer 2.

That is, the composite material 1j is obtained by applying a foamed thermosetting resin liquid to both sides of the reinforced laminated sheet to be the core material layer 3j used in the second embodiment and the reinforced laminated sheet. The sheet is wound several times so that the stretching direction of the stretched polyolefin resin-based sheet (A) coincides with the stretching direction, and then the inside square material is pulled out to obtain a wound laminated sheet. Next, the rolled laminated sheet is placed in a mold, and the foamed thermosetting resin liquid is foamed and cured, thereby producing a sheet.

The composite material 1j has high rigidity and high strength because it is strongly rigidly laminated with the thermoplastic resin sheet (B) without relaxing the orientation of the stretched polyolefin resin sheet (A) during lamination. It is. Further, since the non-woven fabric sheet (C) is present in the outermost layer of the core material layer, physical adhesion between the core material layer main body having high rigidity and high strength and the thermosetting resin layer becomes strong. , High strength and high rigidity. In particular, the core material layer 3j is a composite material 1j
Since they are spirally arranged inside, they have excellent bending strength and elastic modulus in all directions.

Further, since no glass fiber is used, the glass is lightweight and there is no fear that glass residue remains during incineration.

[0057]

Examples of the present invention will be described below.

(Example 1) [Preparation of stretched polyethylene resin sheet] Temperature 200 ° C.
High-density polyethylene (melting point: 135 ° C., melt index (hereinafter referred to as MI, expressed by anonymous number: 1 g / 10 min)) and a high-density polyethylene supplied separately from the high-density polyethylene. 3 parts by weight of triallyl cyanurate (crosslinking aid) and benzophenone (photoinitiator) were uniformly mixed with 100 parts by weight of the density polyethylene, and a 3 mm-thick high-density polyethylene sheet was prepared by a T-die.

The above-mentioned high-density polyethylene sheet was fed before and after a heating furnace using a stretching device provided with a feeding machine and a take-off machine. The feeding speed was 1 m / min, the take-off speed was 30 m / min (drawing ratio was 30 times), and the heating temperature was 30%. The film was stretched at 100 ° C. to produce a stretched polyethylene sheet as a stretched polyolefin resin-based sheet (A) having a thickness of 0.15 mm and a width of 125 mm.

The obtained stretched polyethylene sheet was irradiated with ultraviolet light for 10 seconds using a high-pressure mercury lamp to perform a cross-linking treatment. Then, in order to roughen the stretched polyethylene sheet, the roll temperature was 200 ° C. and the other roll was 200 ° C. Roll temperature is 50 ° C
The stretched polyethylene sheet surface alternately contacts the roll surface at 200 ° C. and the roll surface at 50 ° C. between the first pinch roll temperature-controlled and the second pinch roll in which only the roll temperature is reversed. And the sheet was passed at a line speed of 20 m / min to roughen the surface of the stretched polyethylene sheet.

The center line surface roughness (Ra) of the stretched polyethylene sheet was 2 μm as a result of the measurement using a surface profiler (Dektak 303, manufactured by Nippon Vacuum Engineering Co., Ltd.).

[Preparation of Polyethylene Sheet] A thermoplastic resin having an adhesive property with the above-mentioned stretched polyethylene sheet having a thickness of 0.03 mm by inflation molding of linear low-density polyethylene (melting point 123 ° C., MI = 0.8). A polyethylene sheet was produced as the sheet (B).

[Nonwoven Fabric Sheet (C)] As the nonwoven fabric sheet (C), inexpensive toilet paper having a basis weight of 29 g / m ² (JIS P 8124) and a breaking strength of 90 kPa (10 sheets, JIS P 8112) was used. .

[Preparation of Laminated Sheet] Next, the polyethylene sheet and the stretched polyethylene sheet cut into dimensions of 450 mm in length and 50 mm in width each contain a polyethylene sheet as an outermost layer and five stretched polyethylene sheets. , Alternately, press forming machine (10
The upper and lower molds having parallel and flat mold surfaces on both sides of which are mounted on the upper and lower molds and heated at 125 ° C. (length 450 mm, width 50 m) as shown in FIG.
In m), the stretched polyethylene sheet was charged so that the stretching direction coincided with the longitudinal direction of the mold, press-molded, and pressure-bonded. Next, the mold was cooled to 20 ° C. to prepare a laminated sheet (450 mm in length, 50 m in width, and 0.9 mm in thickness) to be the core material layer main body. Press molding was performed so that the molding pressure was 10 kgf / cm ² during heating and 1 kgf / cm ² during cooling. Further, in a state where toilet paper is laminated on both sides of the obtained laminated sheet, this is placed in a heating furnace whose temperature is controlled to a temperature lower than the melting point of the stretched polyolefin resin sheet and equal to or higher than the melting temperature of the thermoplastic sheet, and the heating furnace By passing between the press rolls installed in the inside, a reinforced laminated sheet which becomes a core material layer having toilet paper adhered to both sides of the laminated sheet was obtained.

[Thermosetting resin] As the thermosetting resin,
Propylene oxide-added polyether (hydroxyl group 48
0, functional groups 4) 140 parts by weight of diphenylmethane diisocyanate (hereinafter simply referred to as "parts"), 100 parts by weight of silicone oil agent for foam control, 0.8 parts of water, 100 parts by weight of dibutyltin laurate as reaction catalyst A thermosetting foamed polyurethane mixture of .15 parts was used.

[Preparation of Composite Material] The above-mentioned thermosetting foamed polyurethane mixture liquid which had been uniformly mixed in advance with a stirrer was uniformly applied to both surfaces of the reinforced sheet using a spray gun. Next, in a state where eight sheets of the reinforcing sheet are stacked,
A spacer in which the thickness of the space in the mold is 25 mm in advance is put into the mold so that the longitudinal direction of the laminated sheet coincides with the longitudinal direction of the mold, pressed again, foamed and hardened, and the length is 450 mm. , Width 50mm, thickness 25mm
A composite material as shown in FIG. The mold temperature at this time was 50 ° C. Vf = about 30% (where Vf
Indicates the volume content of the stretched polyethylene sheet in the composite material. )

(Example 2) The reinforced laminated sheet having the thermosetting foamed polyurethane mixed liquid adhered to both sides thereof was stretched into a square material having a length of 450 mm, a width of 10 mm, and a length of 5 mm, in the longitudinal direction of the square material and in the reinforced sheet. Wind 10 times so that the stretching direction of the polyethylene sheet matches, then,
Except that the rolled laminated sheet obtained by extracting the square material inside was used as a molding material, a composite having a length of 450 mm, a width of 50 mm, and a thickness of 25 mm as shown in FIG. A material was produced (Vf = about 30%).

(Example 3) Except that the number of reinforcing sheets was set to two, the same method as in Example 1 was used to make the length 450
Two composite materials having a thickness of 50 mm, a width of 50 mm, and a thickness of 5 mm were produced (Vf = 30%). Next, expanded shale (trade name: Mesalite Coarse Aggregate, manufactured by Nippon Mesalite Industry Co., Ltd.) as a filler, and propylene oxide-added polyether (hydroxyl group 410, functional group 4) 1 as a thermosetting resin
With respect to 00 parts by weight, 120 parts by weight of diphenylmethane diisocyanate (hereinafter simply referred to as “parts”), 1 part of a silicone oil agent for foam control, 0.7 part of water, and 0.15 part of dibutyltin laurate as a reaction catalyst The resulting thermosetting foamed polyurethane mixture was mixed at a weight ratio of 13: 2 using an Erich mixer to obtain a uniform thermosetting foamed polyurethane composition containing a filler. These are charged into the mold so that the filler-containing thermosetting foamed polyurethane composition is sandwiched by the composite material. Otherwise, the same method as in Example 1 is used to obtain a length of 450 mm, a width of 50 mm, and a thickness of A 25 mm composite material as shown in FIG. 1 was prepared.

(Example 4) The dimensions of the laminated sheet and the reinforced laminated sheet were set to 2200 mm in length and 200 mm in width, and the mold was adjusted to the dimensions of the laminated sheet to have a length of 2200 mm and a width of 2 mm.
The length was 2200 m in the same manner as in Example 1 except that the pressing machine was changed to 00 mm and the pressing machine was changed to a 600-ton pressing machine.
m, a width of 200 mm, and a height of 140 mm were prepared. In addition, when the strength and elastic modulus, workability, and nail pulling strength of the manufactured synthetic sleeper were evaluated, it was completely inferior to synthetic wood and proved to be practical as a railroad sleeper.

(Example 5) The size of the molded product was 220
A synthetic sleeper was produced in the same manner as in Example 2.3, except that the value became 0 × 200 × 140, so that Vf = about 30%. As a result, it was proved that it could be practically used as a railroad sleeper as in Example 1.

(Comparative Example 1) [Expandable resin composition] 140 parts by weight of diphenylmethane diisocyanate (hereinafter simply referred to as "parts") per 100 parts by weight of propylene oxide-added polyether (hydroxyl group 480, functional group 4) A thermosetting foamed polyurethane mixture comprising 1 part of a silicone oil agent for foam control, 0.8 parts of water, and 0.15 part of dibutyltin laurate as a reaction catalyst was used.

[Continuous continuous fiber] Glass fiber bundle using 200 E glass monofilaments (fiber diameter 9 μm) as one strand

The foamable resin composition is sprinkled on the continuous filament at a weight ratio of 1: 1. Then, the continuous filament sprinkled with the foamable resin composition is hand-kneaded and loosened by hand. The foamable resin composition was impregnated into the continuous filament. This is put into a mold (450m long)
m, width 50 mm, thickness 25 mm), the mold was closed, and the mold was fixed with about three clamps so that the mold was not opened by the foaming pressure. Next, the mold was put into an oven heated to about 80 ° C. for 15 minutes, and then naturally cooled to produce a synthetic wood.

In order to evaluate the performance of the composite materials and the laminates obtained in Examples 1 to 3 and Comparative Example 1, JIS Z 21
The flexural strength (vertical), flexural strength (horizontal), flexural modulus (vertical), and compressive strength (partial compression proportional limit strength) were measured by a method according to 01, and the results are shown in Table 1. Also,
Workability, nail pull strength, presence or absence of incinerated ash, and recyclability were also evaluated.

The evaluation methods are as follows: Workability: Cutting workability with a saw (○: comparable to wood, Δ: slightly inferior to wood, ×: unacceptable) Claw removal strength: drilling a pilot hole of 18 mm in diameter and 110 mm in depth Then, the screw was screwed down to 25 mm below the neck, and a pull-out test was performed using a universal testing machine.・ Incineration ash: The presence or absence of glass residue after incineration in an incinerator was checked.・ Recyclability: ○; suitable for thermal recycling,
◎: Material recycling (self-restoration) was possible, ×: Not possible.

[0076]

[Table 1]

[0077]

According to the first aspect of the present invention, the composite material has high strength and high rigidity, and
No incineration ash such as glass residue is generated during incineration, and there is no problem in working environment. Since the composite material according to claim 2 is configured as described above, it is obvious that not only the effect of the composite material according to claim 1 is exerted, but also that, in particular, vertical and horizontal directions in bending strength are generated. Absent.

The composite material according to the third aspect has high strength and high rigidity and is particularly excellent in compressive strength because it is configured as described above. Also, as a filler contained in the thermosetting resin, if a pulverized product of the above-mentioned composite material that has passed the service life is used, it becomes a self-recycling composite material, which reduces global warming gas generated by incineration and the like, It will also be possible to respond to the problem of securing landfill land as industrial waste.

The composite material according to the fourth aspect is characterized in that the thermosetting resin in the composite material is a foamable polyurethane resin, so that the effects of the composite materials according to the first to third aspects are of course exerted. In addition, the workability of cutting and nailing is the same as that of wood, and the pull-out strength of the driven nail is very excellent. Since the synthetic sleeper according to the fifth aspect is made of the composite material of the present invention, the composite sleeper of the present invention has high strength and high rigidity, as well as light weight and excellent workability, and high nail pulling strength. No incineration ash is generated, and there is no problem in working environment. Therefore, it is the most suitable as a railroad synthetic sleeper.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the composite material of the first embodiment.

FIG. 2 is a cross-sectional view of a core layer portion of the composite material of FIG.

FIG. 3 is a sectional view of a mold used for manufacturing the composite material of FIG.

FIG. 4 is a sectional view showing a second embodiment of the composite material of the first embodiment.

FIG. 5 is a sectional view showing a third embodiment of the composite material according to the first embodiment.

FIG. 6 is a sectional view showing a fourth embodiment of the composite material according to the first embodiment.

FIG. 7 is a sectional view showing a composite material according to a fifth embodiment of the present invention.

FIG. 8 is a sectional view showing a sixth embodiment of the composite material of the first embodiment.

FIG. 9 is a cross-sectional view showing an embodiment of the composite material according to claim 2;

[Explanation of symbols]

 1a, 1b, 1c, 1d, 1e, 1f, 1j Composite material 2 Foamed polyurethane resin layer (thermosetting resin layer) 3a, 3b, 3c, 3d, 3e, 3f, 3j Core material layer 31 Core material layer main body 31a Stretched polyolefin resin sheet (A) 31b Thermoplastic resin sheet 32 Non-woven fabric sheet

Continued on the front page F-term (reference) 4F100 AH02H AH03H AK01B AK01D AK03A AK05 AK06 AK51D AK54 AK62A AK66A BA04 BA07 BA08 BA10B BA10D CA02 CA23D CA30 DG10 DG15C DJ04D EC01 EH51 EJ02 EJ05B01 EJ02 EJ05B01 EJ02 EJ05B

Claims (5)

[Claims] 1. A stretched polyolefin-based resin sheet (A) and a thermoplastic resin having a melting temperature lower than the melting point of the stretched polyolefin-based resin sheet (A) and having an adhesive property with the stretched polyolefin-based resin sheet (A). A resin sheet (B) and a core material layer main body portion alternately laminated so that the thermoplastic resin sheet (B) is positioned on at least one surface thereof; and a thermoplastic resin on the surface of the core material layer main body portion. It has at least one core layer composed of a nonwoven sheet (C) laminated along the sheet (B), and the surface of the nonwoven sheet (C) of the core layer is formed of a thermosetting resin (D). A composite material in which a curable resin layer is laminated. 2. A thermoplastic resin having a melting temperature lower than the melting point of the stretched polyolefin resin sheet (A) and the stretched polyolefin resin sheet (A), and having an adhesive property with the stretched polyolefin resin sheet (A). A core material layer main body in which resin sheets (B) are alternately laminated such that the thermoplastic resin sheets (B) are located on both surfaces thereof;
And a state in which a core layer made of a nonwoven fabric sheet (C) laminated along the thermoplastic resin sheet (B) on the surface of the core layer main body is wound in a substantially spiral cross section, or
A thermosetting resin layer is provided in the gap between the portion wound inside the core material layer and the portion wound outside the core material layer, and the portion wound inside the core material layer and the outside A composite material in which a portion wound around is bonded through the thermosetting resin layer. 3. The composite material according to claim 1, wherein a filler is mixed in the thermosetting resin. 4. The composite material according to claim 1, wherein the thermosetting resin is a foamable polyurethane resin. 5. A composite sleeper comprising the composite material according to claim 1.