JP2000296574A - Composite material and synthetic sleepers using this composite material - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a composite material used for a sleeper or the like which is excellent in strength, of course, lightweight, excellent in handleability, low in water absorption and endurable for long-term outdoor use. The purpose is. A core layer, in which a plurality of split pieces obtained by splitting a natural plant raw material in the fiber direction are fixed via a binder so that the fiber directions are aligned in one direction, A fiber reinforcing layer dispersed in a foamed resin so that the fiber direction of the long fiber material is aligned in one direction, and the fiber reinforcing layer changes the fiber direction of the long fiber material to the fiber of the split piece of the core layer. The core layer was laminated on the core layer so as to cover at least two surfaces parallel to the facing fiber directions of the core layer.

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 using the composite material.

[0002]

2. Description of the Related Art Fiber-reinforced composite materials (thermosetting foamed resin molded products) which are very similar in appearance to natural woods and exhibit physical properties equal to or better than those of natural woods are used for building materials, structural members, It is used as a structure such as sleepers and water board.

A conventional composite material of this type is disclosed in
As disclosed in Japanese Patent Application Laid-Open No. 2-2421 or the like, a plate-shaped or rod-shaped molded product main body is formed by foaming and hardening a thermosetting foamed resin liquid, and a long fiber glass is formed in the molded product main body. Thermosetting foamed resin molded articles in which fibers are aligned in the longitudinal direction as reinforcing fibers and dispersed in substantially parallel, or as disclosed in Japanese Patent Application Laid-Open No. Laminated materials and the like have already been proposed in which the split pieces are arranged so that the fiber directions thereof are arranged in one direction, and are integrated via a bonding material by compression molding.

[0004] However, the above-mentioned thermosetting resin molded products and laminated materials have the following problems.
In other words, in the case of the thermosetting resin molded product, glass fiber is used to improve the bending strength of the molded product. However, if a sufficient bending strength is to be exhibited, the weight of the molded product increases. This causes problems in handling.

[0005] On the other hand, the above laminated material is light in weight, but is not suitable for long-term outdoor use because of its water absorption.

[0006]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a composite material which is excellent not only in strength but also lightweight, excellent in handleability, low in water absorption and endurable for long-term outdoor use. It is an object of the present invention to provide a material and a composite sleeper using the composite material.

[0007]

In order to achieve such an object, a composite material according to claim 1 of the present invention (hereinafter referred to as a composite material).
"Composite material of claim 1") includes a plurality of split pieces obtained by splitting a natural plant raw material in the fiber direction through a binder so that the fiber directions are aligned in one direction. And a fiber reinforcing layer dispersed in a foamed resin such that the fiber direction of the long fiber material is aligned in one direction, and the fiber reinforcing layer comprises a fiber of the long fiber material. The direction was made to match the fiber direction of the split pieces of the core layer, and the core layer was laminated on the core layer so as to cover at least two surfaces parallel to the opposite fiber directions.

The composite material according to claim 2 of the present invention (hereinafter referred to as “composite material according to claim 2”) is the composite material according to claim 1, wherein the entire surface of the surface parallel to the fiber direction of the core layer is provided. ,
The fiber reinforcement layer was laminated.

The composite material according to claim 3 of the present invention (hereinafter referred to as the “composite material of claim 3”) comprises a plurality of split pieces obtained by splitting a natural plant raw material in the fiber direction. However, a core layer fixed via a bonding material so that the fiber directions are aligned in one direction, and fibers in which a long fiber material is dispersed and arranged in a foamed resin so that the fiber directions are aligned in one direction And a reinforcing layer, the fiber reinforcing layer
The fiber direction of the long fiber material was orthogonal to the fiber direction of the split pieces of the core layer, and the fiber was laminated so as to cover both end faces in the fiber direction of the core layer.

[0010] A synthetic sleeper according to the present invention is formed from the composite material of claims 1 to 3.

In the present invention, the natural plant raw material is not particularly limited. For example, conifers such as hiba and cedar, beech and southern hardwood, and moso bamboo and the like, which have been widely used as a laminated material, are conventionally used. Bamboo materials. In addition,
The split pieces are preferably kept dry. The binder is not particularly limited as long as the split pieces (fibrous materials) can be bound. For example, unsaturated polyester, epoxy, polyurethane, phenol, vinyl acetate and the like are preferable, and may be foamed.

[0012] The shape of the long fiber material is not limited as long as it has a function as a reinforcing fiber.
Monofilaments, fibrillated (protruding beard-like fibers) fibers, woven yarns and the like can be mentioned. Examples of the material include organic fibers such as synthetic fiber resin and inorganic fibers such as glass and carbon. In particular, glass or carbon has a large reinforcing effect and is suitable.

The foamed resin is not particularly limited.
For example, a pyrolytic foaming agent or a soluble foaming agent such as Freon,
Rigid or semi-rigid polyurethane foams formed from thermosetting foamed resin liquids containing those by-produced during reaction curing, phenolic foams, low-magnification polyester foams, etc., among these, polyurethane foams are compared It has an extremely high mechanical strength and is characterized by being excellent in non-water-absorbing properties due to the formation of closed cells during foaming, and is suitably used.

The method for producing a composite material of the present invention may be a batch type or a continuous type. As a batch-type manufacturing method, for example, a method as disclosed in Japanese Patent Application Laid-Open No. 7-195313, in which a plurality of split pieces are combined by curing of a binder to obtain a split piece assembly serving as a core layer After a while
The long fiber bundle is impregnated with the foamed resin liquid, and the foamed resin is left uncured, and the resin-impregnated long fiber bundle is arranged in the mold so as to cover a predetermined surface of the split piece assembly, and foamed in the mold. A method of heating, foaming and curing the resin liquid may be used.

On the other hand, as a continuous production method, for example, a method as disclosed in Japanese Patent Application Laid-Open No. Hei 7-195313, in which a large number of split pieces are stacked so that their fiber directions are aligned in one direction. The split pieces are successively placed on a belt conveyor, the binder is sprinkled on the split pieces on the belt conveyor, and then pressed between the belt conveyor and a pressing roll to form a laminate having a predetermined thickness. .

Then, while the binder is in an uncured state,
After the group of long fibers sprinkled with the foamed resin liquid is placed along the upper and lower surfaces of the laminate, it is introduced into a cylindrical molding passage, and the foamed resin liquid is heated and foamed and hardened in the molding passage at the same time as the molding passage. A method of forming into a cross-sectional shape is exemplified.

In the composite material according to the first aspect of the present invention, it is preferable to laminate a water-absorbing prevention layer made of a non-water-absorbing material on a surface of the core layer which is not covered with the fiber reinforcing layer. Examples of the non-water-absorbing material include, but are not particularly limited to, polyester and polyurethane. Note that the water absorption prevention layer may be in a foamed state.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the composite material according to claim 1.

As shown in FIGS. 1A and 1B, the composite material 1a includes a core layer 2a and a fiber reinforcing layer 3. As shown in FIG. 1 (a), the core layer 2a has a large number of split pieces 21 obtained by splitting natural plant raw materials such as wood and bamboo in the fiber direction, and the split pieces 21 extend in the longitudinal direction of the core layer 2a. The fibers are laminated so that the fiber directions are aligned in one direction.
As shown in (b), two surfaces of the split pieces 21 facing in parallel with the fiber direction are covered with the fiber reinforcing layer 3 via the bonding material 22.

That is, the fiber reinforcing layer 3 is made of the long fiber material 3
1 are distributed in the foamed resin 32 so that the fiber directions thereof are aligned in one direction. As shown in FIG. 1A, the fiber direction is the same as the fiber direction of the split pieces 21 of the core layer 2a. Is laminated on the core layer 2a. The surface of the core layer 2a on which the fiber reinforcing layer 3 is not provided is shown in FIG.
As shown in (b), it is covered with a water absorption preventing layer 4 formed of a non-water absorbing material.

As described above, the composite material 1 has the core layer 2
Since “a” is formed by the split pieces 21 and the binder 22 of the natural plant raw material, it is lightweight and has excellent handleability. In addition, since the core layer 2a is covered with the fiber reinforcing layer 3 and the water absorption preventing layer 4, the split pieces 21 constituting the core layer 2a are not directly exposed to rainwater or the like, so that the water absorption is small, and the core 21 is used outdoors. It can also be suitably used for applications that are left for a long time.

Further, since the fiber direction of the split pieces 21 and the fiber direction of the long fibers of the fiber reinforcing layer 3 are oriented in the longitudinal direction of the composite material 1a, the bending strength in the longitudinal direction is excellent.

FIG. 2 shows an embodiment of the composite material according to claim 2. As shown in FIG. 2, the composite material 1b is the same as the composite material 1a except that the entire periphery of the core layer 2a is covered with the fiber reinforcement layer 3 instead of the water absorption prevention layer 4. .

FIG. 3 shows an embodiment of the composite material according to claim 3. As shown in FIG. 3, the composite material 1c is the same as the composite material 1b except that the fiber directions of the split pieces are aligned in the width direction of the core layer 2b.

That is, according to the composite material 1c, the bending strength in the longitudinal direction is weaker than that of the composite materials 1a and 1b, but the strength in the width direction is higher, and the composite material 1c can be used in a place where two directions of strength are required. Becomes

[0026]

Embodiments of the present invention will be described below in more detail.

(Example 1) Using a device 5 shown in FIG. 4, a fiber reinforced layer is formed around the core layer 2d so that the fiber direction of the split pieces and the fiber direction of the reinforcing fibers match as shown in FIG. 3
d, each part had the dimensions as shown in FIG. 5, and a composite material 1d was obtained in which the core layer 2d and the fiber reinforced layer 3d had the blending conditions shown in Table 1 below.

[0028]

[Table 1]

The device 5 shown in FIG.
Are stacked so that their fiber directions are aligned in one direction,
This split piece group 21a is continuously placed on the belt conveyor 51, and the bonding material 22 is split on the belt conveyor 51 by the split piece group 2.
After sprinkling on 1a, it is pressed between the pressing roll 52 and the belt conveyor 51 to form a laminate 2 'having a predetermined thickness.

Then, while the binder 22 is in the uncured state, the long fibers 34 on which the foamed resin liquid 33 is sprinkled are arranged along the upper and lower surfaces of the laminate 2 ′.
3, the binder 22 and the foamed resin liquid 33 are heat-cured or heat-foamed and hardened in the molding passage 53, and are simultaneously formed into the cross-sectional shape of the molding passage 53 at the same time. In FIG. 4, reference numeral 54 denotes a take-off machine.

(Example 2) Fig. 6 (FIG. 6) shows that the split pieces of Moso bamboo were mixed with a hard polyurethane resin liquid as a binder in a state where their fiber directions were aligned in one direction so as to have the compounding ratio shown in Table 2 below. Internal dimensions 1000 x 1000 x 3 shown in a)
After being put into a 0 mm preforming mold 61 and preformed into the shape of the preforming mold 61, the glass fiber direction of the split pieces was set so as to be orthogonal to the fiber direction of the split pieces around the preform 2e.
FIG. 6 shows a state in which a glass fiber roving impregnated with a hard polyurethane resin liquid as a foamed resin shown in FIG.
(B) As shown in FIG.
It is transferred to a molding die 62 of 1010 × 46 mm, and as shown in FIG. 6C, the uncured resin is foamed and cured in the molding die 62 to obtain the composite material 1e with each part having the dimensions shown in FIG. Was.

[0032]

[Table 2]

(Comparative Example 1) A split piece (about 3 × 3 × 800 mm) of beech wood, which is the same as the core layer of Example 1, and a hard urethane resin liquid as a binder were used in the same mixing ratio as in Example 1. The width of the split fibers in the longitudinal direction is 200 mm in width and 15 in height.
A sample compact having a cross-sectional shape of 0 mm was obtained. Comparative Example 2 The same glass fiber roving as the surface layer of Example 1 and a hard urethane resin liquid were used in the same mixing ratio as the surface layer of Example 1, and the width 2 in which the glass fibers were arranged in the longitudinal direction.
A sample compact having a cross-sectional shape of 00 mm and a height of 150 mm was obtained.

Comparative Example 3 The same glass fiber roving as the surface layer of Example 2 and a hard urethane resin liquid were used in Example 2.
Using the same blending ratio as that of the surface layer, a sample molded body having a cross-sectional shape of 1010 mm in width and 46 mm in height in which glass fibers were arranged in the longitudinal direction was obtained. (Comparative Example 4) The same glass fiber roving as that of the surface layer of Example 2 and a hard urethane resin liquid were used in the same mixing ratio as the surface layer of Example 1, and the width of the glass fibers in the width direction was 10 mm.
A 1010 mm wide, 10 mm wide, 46 mm high surface layer with a 10 mm wide, 8 mm high cross-sectional shape with glass fibers arranged in the longitudinal direction on the upper and lower surfaces of a core layer having a cross-sectional shape of 10 mm, 30 mm high.
A sample compact having a cross-sectional shape of mm was obtained.

(Comparative Example 5) Using the same splitting pieces of Moso bamboo as the core layer of Example 2 and the hard urethane resin liquid as the binder in the same mixing ratio as in Example 1, the fibers of the splitting pieces were cut in the width direction. Width 1010 in which fibers of split pieces are arranged in the longitudinal direction on the upper and lower surfaces of a core layer having a cross-sectional shape of width 1010 mm and height 30 mm.
mm, width 101 provided with a surface layer having a cross-sectional shape of 8 mm in height
A sample compact having a cross-sectional shape of 0 mm and a height of 46 mm was obtained.

The bending strength in the longitudinal direction, the bending strength in the width direction, the lateral water absorption and the density of the composite materials and the sample molded bodies obtained in Examples 1 and 2 and Comparative Examples 1 to 5 were measured. 3 is shown. In addition, the bending strength and the side surface water absorption were measured by the method of JIS Z 2101.

[0037]

[Table 3]

Table 3 shows that the composite material of the present invention (Example 1,
It can be seen that 2) is lightweight and excellent in strength and low in water absorption. Especially according to the second embodiment,
It can be seen that the bending strength not only in the longitudinal direction but also in the width direction is improved.

[0039]

As described above, the composite material according to the present invention is light in weight and excellent in handleability since the core layer is formed of a light natural plant material split piece. And since the core layer is covered with the coating layer, even if a natural plant material is used for the core layer, the water absorption is small. In particular, according to the composite material of the first and second aspects, the bending strength in the longitudinal direction is excellent.

On the other hand, according to the composite material of the third aspect, not only the bending strength in the longitudinal direction but also in the width direction is excellent. On the other hand, since the synthetic sleeper according to the present invention uses the composite material of the present invention, it is lightweight, has good handleability, and has low water absorption, so that it can sufficiently withstand long-term outdoor use. .

[Brief description of the drawings]

FIG. 1 shows an embodiment of the composite material of claim 1, wherein FIG. 1 (a) is a sectional view thereof, and FIG. 1 (b) is a sectional view taken along line XX of FIG. 1 (a).

FIG. 2 shows an embodiment of the composite material according to claim 2, wherein FIG. 2 (a) is a sectional view thereof, and FIG. 2 (b) is a sectional view taken along line YY of FIG. 2 (a).

FIG. 3 shows an embodiment of the composite material according to claim 3, wherein FIG. 3 (a) is a cross-sectional view thereof, and FIG. 3 (b) is a cross-sectional view taken along line ZZ of FIG. 3 (a).

FIG. 4 is a schematic view schematically showing an apparatus used for manufacturing the composite material of Example 1.

FIG. 5 is a dimensional diagram of the composite material obtained in Example 1.

FIG. 6 is an explanatory view for sequentially explaining a manufacturing process of a composite material of Example 2.

FIG. 7 is a dimensional diagram of the composite material obtained in Example 2.

[Explanation of symbols]

 1a, 1b, 1c, 1d, 1e Composite material 2a, 2b Core layer 21 Split piece 22 Binder 3a Surface layer 31 Long fiber material 32 Foam resin

Claims (4)

[Claims] 1. A core layer comprising a plurality of split pieces obtained by splitting a natural plant raw material in a fiber direction thereof, which are fixed via a binder so that the fiber directions are aligned in one direction. And a fiber reinforcing layer dispersed in the foamed resin so that the fiber direction of the long fiber material is aligned in one direction, and the fiber reinforcing layer adjusts the fiber direction of the long fiber material to the split of the core layer. A composite material that is laminated to a core layer so as to match the fiber direction and to cover at least two surfaces of the core layer parallel to the opposite fiber directions. 2. The composite material according to claim 1, wherein a fiber reinforcing layer is laminated on the entire surface of the core layer parallel to the fiber direction. 3. A core layer comprising a plurality of split pieces obtained by cleaving a natural plant raw material in the fiber direction, the core layer being fixed via a binder so that the fiber directions are aligned in one direction. And a fiber reinforcing layer dispersed in the foamed resin so that the fiber direction of the long fiber material is aligned in one direction, and the fiber reinforcing layer adjusts the fiber direction of the long fiber material to the split of the core layer. A composite material that is laminated so as to be orthogonal to the fiber direction and to cover both end surfaces of the core layer in the fiber direction. 4. A composite sleeper comprising the composite material according to claim 1.