JP2003206502A - Sleeper for railroad and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sleeper for railroad capable of enduring huge load of rolling stock, suppressing resonance phenomenon to reduce vibration and noise, being simply constructed in the same way as a wooden sleeper, and being used even in a branch part where vibration is large and position correction of track is frequently performed. <P>SOLUTION: This sleeper for railroad comprises a thermosetting urethane foam, vinyl polymer particles which are scattered like particles away from each other in a cell wall of the thermosetting urethane, foam and whose glass transition point is in the range of 0 to 50°C, and a long fiber reinforcing material scattered in the thermosetting urethane foam so that the longitudinal direction becomes parallel for the longitudinal direction of the thermosetting urethane foam. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a railway sleeper, and more particularly to a railway sleeper made of a thermosetting urethane foam or a cured product reinforced with a fiber reinforcement and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, one of the causes of vibration and noise on a railroad track when passing a vehicle is resonance of the track. Therefore, in order to reduce vibration and noise, a method of providing a so-called track pad between the rail and the sleeper, and between the sleeper and the ballast floor or the concrete floor has been proposed (Japanese Patent Laid-Open No. 2000-281745). .
In addition, a method (Japanese Unexamined Patent Publication No. 2001-172901) for accommodating sleepers in a box having an anti-vibration action, in which an elastic body is arranged on the inner surface, has also been proposed.

However, prior to the construction of sleepers,
The work of adhering the track pad or inserting the pad during construction was complicated. In addition to the sleepers, the work of bringing in and installing a box having an anti-vibration action at the construction site becomes complicated. That is, in any of the methods described in the above-mentioned prior art, it is
It is a track pad or a box with anti-vibration action, and the sleeper itself is not configured to reduce vibration or noise.

On the other hand, Japanese Patent Laid-Open No. 2000-1801 discloses a concrete sleeper having a function of reducing vibration and noise. However, since the sleepers are made of concrete, it is heavy and difficult to construct by hand.

There is also a problem that screw nails and dog nails for fixing the rails to the sleepers cannot be freely driven to positions. Furthermore, since the sleepers are formed by batch molding in which concrete is poured into the formwork, it is difficult to change the length of the sleepers freely, and the length of each sleeper is different and vibration is large, so the position of the track is corrected. Couldn't be used at a branch that is often needed.

[0006] As the sleepers used at the branch portion of the track, wooden sleepers and sleepers made of a synthetic resin composite material have hitherto been used. A sleeper made of a synthetic resin composite material has excellent durability and can be easily constructed like a wooden sleeper. Sleepers made of this kind of synthetic resin composite material
It is mainly composed of glass fiber reinforced thermosetting urethane foam.

By the way, various attempts have been hitherto made to give a thermosetting urethane foam a vibration absorbing property (for example, Japanese Patent Laid-Open No. 11-286566). However, the conventional thermosetting urethane foam provided with vibration absorption is made relatively soft to absorb vibration. Therefore, when used as a railroad sleeper to which a large amount of weight is applied, even if it is reinforced with glass fibers, it is impossible to withstand a huge load.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned state of the art, the present invention is capable of withstanding the enormous load of railway vehicles, suppressing resonance phenomena, and reducing vibration and noise. An object of the present invention is to provide a railroad sleeper that can be easily constructed like a wooden sleeper and can be used at a branch portion where vibration is large and the track position is frequently corrected.

[0009]

A railroad sleeper of the invention (invention 1) according to claim 1 of the present application comprises a thermosetting urethane foam and a cell wall of the thermosetting urethane foam which are mutually The vinyl polymer particles, which are separated from each other and have a glass transition point in the range of 0 to 50 ° C., and the longitudinal direction is parallel to the longitudinal direction of the thermosetting urethane foam. A long fiber reinforcing material dispersed in the thermosetting urethane foam is included.

The invention of claim 2 of the present application (invention 2) is a method of manufacturing a railway sleeper of the invention 1, wherein at least a part of the vinyl polymer is graft-polymerized. It is characterized in that a thermosetting urethane undiluted solution comprising the above-mentioned polyol and polyisocyanate is used as a raw material for forming a thermosetting urethane foam.

The method of manufacturing a railway sleeper of the invention (invention 3) according to claim 3 of the present application is the method of manufacturing a railway sleeper of invention 1, wherein at least a part of the vinyl polymer is graft-polymerized. Characterized in that a thermosetting urethane undiluted solution consisting of a polymer polyol which has been polymerized, a polyol in which the vinyl polymer has not been graft-polymerized, and a polyisocyanate is used as a raw material for forming a thermosetting urethane foam. .

In the method for manufacturing railway sleepers of the present invention 2 or 3, the thermosetting urethane stock solution has a glass transition point of 0.
It is preferable that the mixture contains the vinyl polymer in the range of -50 ° C in a proportion of 5 to 45% by weight based on the total amount of the resin (Invention 4).

In the railroad sleeper manufacturing methods of the present inventions 2 to 4, it is preferable to impregnate the long fibers with the raw material for forming the thermosetting urethane foam, and then cure and foam (the present invention 5). ).

The invention according to claim 6 of the present application (invention 6)
Is a railroad sleeper obtained by impregnating a thermosetting urethane stock solution in a long-fiber reinforcing material whose longitudinal directions are parallel to each other and thermosetting the same, wherein the thermosetting urethane stock solution has a glass transition point of 0. A vinyl polymer having a melting point of 0 to 50 ° C. or a crystalline polymer having a melting point of 0 to 50 ° C., based on the total amount of resin.
It is a mixture containing 60 to 60% by weight, and after curing, the vinyl polymer or the crystalline polymer having a melting point of 0 to 50 ° C. is dispersed in a resin, and the resin has a dynamic viscoelasticity. The value of tan δ when the test is performed is 0.1 or more at 0 to 50 ° C.

In the railroad sleeper of the present invention 6, the thermosetting urethane undiluted solution is a two-part curable type comprising a polyol undiluted solution and a polyisocyanate undiluted solution, and the polyol undiluted solution contains a crystalline polymer chain in the molecule. Average molecular weight of 7
Polyol A of 00-4500 and an average molecular weight of 300-having a polymer chain having a structure similar to the polymer chain in the molecule
Polyol B of 1500 and Polyol C having a hydroxyl value of 400 mgKOH / g or more with no polymer chain in the molecule
The polyol A is 30 to 80% by weight of the whole polyol stock solution, the polyol B is 5 to 35% by weight of the whole polyol stock solution, and the polyol C is 5 to 45% by weight of the whole polyol stock solution. Is preferred (Invention 7).

In the railroad ties of the present invention 1, 6 or 7,
The long fiber reinforcing material is preferably contained in an amount of 10 to 25% by volume based on the whole (Invention 8).

The details of the present invention will be described below. In the cell wall, the vinyl polymer particles are embedded in the thermosetting urethane foam constituting the cell wall, and the vinyl polymer particles are exposed on the cell wall of the thermosetting urethane foam. It also includes the state of being. In the case where the vinyl polymer particles completely penetrate the cell wall or form a continuous layer instead of particles, the vinyl polymer portion becomes a defect point in the thermosetting urethane foam and is used for railways. The strength of the sleepers and the durability against repeated loads are reduced.

The glass transition point is a peak temperature of tan δ when the dynamic viscoelasticity is measured at a frequency of 10 Hz and a heating rate of 2 ° C./min. Glass transition point is 0
Outside the range of 50 ° C, the effect of sufficiently reducing vibration and noise at the practical temperature of the sleeper cannot be obtained.

The thermosetting urethane used in the present invention 1 is obtained by mixing and reacting polyisocyanate and polyol. The vinyl polymer is used before mixing the polyisocyanate and the polyol. And / or may be dispersed in the polyol, and may be dispersed at the time of mixing the polyisocyanate and the polyol or after the mixing.

However, it is preferable that at least a part of the vinyl polymer is graft-polymerized with the polyol. By the graft polymerization, the vinyl polymer is stably dispersed as fine particles in the polyol, and the vinyl polymer is used in the cell wall of the thermosetting urethane foam by using the graft polymerized polyol as a raw material. It becomes easier to disperse the particles apart from each other.

When a part of the vinyl polymer is graft-polymerized with a polyol, the proportion of the vinyl polymer grafted with the polyol is preferably 5% by weight or more. If it is less than 5% by weight, the vinyl polymer particles may aggregate to form a continuous layer or jump out from the wall surface of the cell wall, and the strength of the composite material and the durability against repeated load may decrease. .

The graft polymerization can be carried out by simultaneously radically polymerizing monomers constituting a vinyl polymer in a polyol. The monomer component constituting the vinyl polymer is polymerized from the radical transferred to the polyol as a starting point, or the radical transferred to the polyol and the polymerization growth end of the vinyl polymer undergo a termination reaction, whereby the polyol and the vinyl polymer become Be combined.

The vinyl polymer is not particularly limited, but (A) styrene or at least one monomer selected from (meth) acrylic acid ester, and (B)
It is desirable to use a copolymer with at least one monomer selected from (meth) acrylic acid aliphatic ester and aliphatic carboxylic acid vinyl ester.

Styrene and methyl methacrylate are preferably used as the monomer (A). As the monomer (B), ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, vinyl acetate and the like are preferably used.

By using the monomer (A) and the monomer (B) in combination, the action of reducing the vibration and noise of the railway sleepers according to the present invention can be controlled with high accuracy. In addition, in the present invention, in addition to the monomers (A) and (B), a monomer such as butadiene or acrylonitrile is used as a component constituting the vinyl polymer in order to improve toughness and strength. You may use.

The monomer (A) in the vinyl polymer
The weight ratio of the monomer (B) to the monomer may be adjusted so that the glass transition point of the vinyl polymer falls within the range of 0 to 50 ° C.

As the long-fiber reinforcing material, a combination of inorganic fibers such as glass fibers and carbon fibers, or Robinck made of organic fibers such as aramid fibers in one direction is used. You may use together.

As the raw material of the thermosetting urethane foam used in the present invention 1, the above-mentioned polyisocyanate and polyol are used. As polyisocyanate, methylene diphenyl diisocyanate (MDI)
Aromatic polyisocyanates such as and tolylene diisocyanate (TDI) and their polynuclear bodies (so-called crude products); aliphatic polyisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate and their polynuclear bodies can be used.

Polyols such as polypropylene glycol, polyethylene glycol and polytetramethylene glycol; aliphatic polyester polyols; copolymers and mixtures thereof may be used as the polyol. Of these, polypropylene glycol and polytetramethylene glycol are preferably used in consideration of hydrolysis resistance, low temperature impact resistance, low water absorption and the like.

Further, an appropriate foaming agent may be added as a raw material of the thermosetting urethane foam. As a foaming agent,
Examples thereof include water, gases such as carbon dioxide, vaporized compounds, and thermally decomposable foaming agents.

In the manufacture of the railway sleepers according to the second aspect of the present invention, the raw material for forming the uncured thermosetting urethane foam is impregnated or after impregnation with the long fiber reinforcements aligned. A continuous method in which long fibers are aligned and introduced into a mold composed of a continuous belt in the aligned state, and foamed and cured; long fibers are aligned in the mold and uncured thermosetting urethane A batch method in which a foam raw material is sprinkled, a mold is closed, and foaming and curing are performed is used.

The thermosetting urethane stock solution used in the present invention 4 contains a vinyl polymer having a glass transition point in the range of 0 to 50 ° C. in an amount of 5 to 45% by weight based on the total amount of the resin.
It is a mixture containing in the ratio of.

In the present invention 1, the vinyl polymer is present in the form of particles in the foamed cell wall apart from each other. The above foam cell wall shall include a state in which the particles of the vinyl polymer are buried in the foam forming the foam cell wall and a state in which the particles of the vinyl polymer are exposed from the foam cell wall surface. . The vinyl polymer or crystalline polymer is preferably mixed in a proportion of 5 to 45% by weight based on the total amount of resin. If it is less than 5% by weight, the effect of suppressing vibration is reduced, and if it exceeds 45% by weight, it becomes difficult to separate particles into the foamed cell wall and disperse them into particles, and particles larger than the foamed cell wall are easily formed. . When such large particles completely penetrate the foamed cell wall or form a continuous layer instead of particles, the strength of the railway sleepers and the durability against repeated load are reduced.

In the present invention 1, the thermosetting urethane undiluted solution is a two-part curable type comprising a polyol undiluted solution and a polyisocyanate undiluted solution, and the polyol undiluted solution is
A mixture of a polymer polyol in which at least a part of the vinyl polymer is graft-polymerized and a polyol in which the vinyl polymer is not graft-polymerized is preferable.

In the present invention 6, the vinyl polymer is mixed in a proportion of 20 to 60% by weight based on the total amount of resin. If it is less than 20% by weight, the amount of compatibility is insufficient and the effect of suppressing vibration is lost, and if it exceeds 60% by weight, the amount of compatibility is excessive and it is difficult to obtain the strength and durability required for railway sleepers. Becomes In addition, tan when a dynamic viscoelasticity test was performed on a resin cured product containing no long fiber reinforcement
The value of δ needs to be 0.1 or more at 0 to 50 ° C. If it is less than 0.1, vibration cannot be suppressed.

In the present invention 6, the vinyl polymer and the crystalline polymer are present in the resin as compatible with each other. The crystalline polymer has a melting point of 0 to 50 ° C. and is preferably provided as a polyol stock solution in a two-part curable thermosetting urethane stock solution. As such a polyol,
A long-chain polymer chain obtained by polymerizing a compound containing an arbitrary alkylene group having 4 or more carbon atoms in series represented by the general formula -R-: represented by the general formula [-R-O-] _n. Polyether chain, general formula [CO-RO-] _n or [CO
-R-CO-O-R'-O-] _n has a polyester chain or the like represented in the molecule, and preferably has an average molecular weight of 300.
.About.4500 polyols. Average molecular weight is 3
If it is less than 00, the effect of suppressing vibration is lost. On the other hand, when it exceeds 4500, it becomes difficult to be compatible and dispersed in the resin. These polyols may be produced by a known method, but as commercially available products, polytetramethylene glycol (HO-[-RO-] _n- H, R- (containing a hydroxyl group at the terminal may be used. C
H ₂ ) ₄ ), polycaprolactone glycol (HO-
[-CO-R-O-] _{n -H, R = (CH 2} ) 5) it can be exemplified.

The vinyl polymer and the crystalline polymer are mixed in a proportion of 20 to 60% by weight based on the total amount of resin.
If it is less than 20% by weight, the amount of compatibility is insufficient and the effect of suppressing vibration is lost, and if it exceeds 60% by weight, the amount of compatibility is excessive and it is difficult to obtain the strength and durability required for railway sleepers. Becomes Further, the value of tan δ when the dynamic viscoelasticity test is performed on the resin cured product not containing the long fiber reinforcing material needs to be 0.1 or more at 0 to 50 ° C.
If it is less than 0.1, vibration cannot be suppressed.

In the present invention 6, the thermosetting urethane undiluted solution is a two-part curable type comprising a polyol undiluted solution and a polyisocyanate undiluted solution, wherein the polyol undiluted solution is
Average molecular weight of crystalline polymer chain 700-4
500 polyol A and an average molecular weight of 300 to 1500 having in the molecule a polymer chain having a structure similar to that of the polymer chain
It is preferable that the polyol B is a mixture of the polyol B and the polyol C having a hydroxyl value of 400 mgKOH / g or more having no polymer chain in the molecule (Invention 7).

[0039] In the present invention 7, polyol A is formula polyether chain represented by [-R-O-] _n, the general formula [-CO-R-O-] _n or [-CO-R-CO -O
-R'-O-] _n is a polyol having an average molecular weight of 700 to 4500, having a relatively long polymer chain in the molecule, selected from the polyester chains represented by -R'-O-] _n . Where -R-
The H-series is an alkylene group having 4 or more carbon atoms, and the polyol A is crystalline. These polyols may be produced by a known method, but as commercially available products, polytetramethylene glycol (HO-[-RO-] _n- H, R = having a hydroxyl group at the terminal may be used.
(CH ₂ ) ₄ ), polycaprolactone glycol (HO
- [- CO-R-O-] _{n -H, R = (CH 2} ) 5) it can be exemplified.

In the present invention 7, the polyol B is generally
Formula [-R-O-]_nA polyether chain represented by the general formula
[-CO-RO-]_nOr [-CO-R-CO-O
-R'-O-]_nSelected from polyester chains represented by
Average molecular weight with a relatively short polymer chain in the molecule
It is a polyol of 300-1500. Where -R-
H series is any alkylene group having 2 or more carbon atoms and is a crystal
It has a structure similar to that of Polyol A with or without properties.
To do. These polyols can be prepared by known methods.
Although it can be manufactured as a commercially available product,
Is a polyethylene glycol containing a hydroxyl group at the end
(HO-[-R-O-]_n-H, R = (CH ₂)₂),
Polypropylene glycol (HO-[-RO-])_n−
H, R = CH (CH₃) CH₂), Polytetramethylene
Glycol (HO-[-RO-]_n-H, R = (CH
₂)₂), Polycaprolactone glycol (HO-[-
CO-RO-]_n-H, R = (CH₂)_Five) Is illustrated
Be done.

In the present invention 7, the polyol C is a hydroxyl value having no polymer chain in the molecule of 400 mgKOH /
It is a polyol of g or more, preferably 500 mg KOH / g or more. If the hydroxyl value is less than 400 mgKOH / g, it will be difficult to obtain the strength and durability required for railway sleepers.

In the present invention 7, it is necessary that the polyol A is 30 to 80% by weight of the whole polyol stock solution, the polyol B is 5 to 35% by weight of the whole polyol stock solution, and the polyol C is 5 to 45% by weight of the whole polyol stock solution. There is.
When the content of the polyol A is within the above range, the glass transition point of the railway sleeper resin is lowered and the vibration is suppressed. On the other hand, when the amount is too small, the vibration suppressing effect is insufficient and the amount is large. If it is too much, it becomes difficult to compatibilize in the resin, the hydroxyl value number of the polyol is not stable, and a problem occurs in reactivity. When the polyol B is within the above range, the polyol A having a high molecular weight can be compatibilized in the resin, whereas when the amount is too small, it becomes difficult to compatibilize the polyol A in the resin, and the hydroxyl acid The valence is not stable,
Reactivity causes problems. When the content of the polyol C is within the above range, the crosslink density of the resin can be increased and the strength and durability required for a railway sleeper can be imparted, whereas when the amount is too small, it is used as a railway sleeper. It becomes difficult to obtain the required strength and durability, and if the amount is too large, the effect of suppressing vibration is reduced.

In the railway sleepers according to the present invention 1, 6 or 7, the long fiber reinforcing material is 10 to 25 relative to the entire railway sleepers.
It is desirable that the content is vol% (Invention 8). If the content of the long fiber reinforcing material is less than 10% by volume, the vinyl polymer becomes flexible at a temperature above the glass transition point of the vinyl polymer,
It may not be possible to maintain the flexural modulus required for railway sleepers.

When the content of the long fiber reinforcing material exceeds 25% by volume, it may be difficult to drill a pilot hole for driving a dog nail or a screw nail for fixing a rail to a railroad sleeper. Wears quickly and cracks may occur on the surface of the sleepers when driving in dog nails or screw nails.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be clarified by describing specific examples of the present invention. The present invention is not limited to the examples below.

(Preparation of Polyol Containing Vinyl Polymer) Polypropylene glycol ("P-1" manufactured by Asahi Denka Co., Ltd.)
000 ”, average molecular weight 1000, hydroxyl value 110 mgK
OH / g) 120 parts by weight, styrene monomer 40 parts by weight, n-butyl acrylate monomer 60 parts by weight,
It was heated to 80 ° C. under a nitrogen atmosphere and stirred uniformly. Graft polymerization was performed by adding 0.1 part by weight of benzoyl peroxide, and after the polymerization was completed, a liquid polymer was thinly cast on an aluminum vat lined with a Teflon (registered trademark) sheet, and residual monomers were removed by heating under reduced pressure. After that, a vinyl polymer-containing polyol B in a stable suspension state having a vinyl polymer content of 38% by weight was obtained.

(Example 1) 80 parts by weight of the vinyl polymer-containing polyol obtained as described above and a polyether polyol ("Sumiphen 1" manufactured by Sumika Bayer Urethane Co., Ltd.) were used.
703 "and a hydroxyl value of 380 mgKOH / g) 20 parts by weight are mixed vigorously at room temperature to obtain a stable suspension, which is used as a polyol stock solution. As a polyisocyanate stock solution, a polymeric MDI (Sumijour 44V20 manufactured by Sumika Bayer Urethane Co., Ltd.) is used. , NCO% = 31%) 44 parts by weight, 0.6 parts by weight of water as a foaming agent, and 0.15 parts by weight of dibutyltin laurate as a catalyst are vigorously mixed, and a thermosetting urethane stock solution having a vinyl polymer content of 21% by weight. Got E glass roving (17 micron monofilament polymer) prepared by aligning 50 parts by weight of this thermosetting urethane stock solution in a mold.
Sprinkle on 50 parts by weight, foam and cure at 80 ° C for 30 minutes,
A railway sleeper having a glass fiber content of 18% was obtained.

Example 2 20 parts by weight of the vinyl polymer-containing polyol obtained as described above and a polyether polyol (“Sumiphen 1” manufactured by Sumika Bayer Urethane Co., Ltd.) are used.
703 "and 30 parts by weight of hydroxide value 380 mgKOH / g) at room temperature, a stable suspension obtained is used as a polyol stock solution, and as a polyisocyanate stock solution, a polymeric MDI (Sumijour 44V20 manufactured by Sumika Bayer Urethane Co., Ltd.) is used. , NCO% = 31%), 38 parts by weight of water, 0.3 part by weight of water as a foaming agent, and 0.07 part by weight of dibutyltin laurate as a catalyst are vigorously mixed to prepare a thermosetting urethane stock solution having a vinyl polymer content of 9% by weight. Obtained. E glass roving (17 micron monofilament polymer) prepared by aligning 50 parts by weight of this thermosetting urethane stock solution in a mold.
Sprinkle on 50 parts by weight, foam and cure at 80 ° C for 30 minutes,
A railway sleeper having a glass fiber content of 18% was obtained.

Comparative Example 1 Only 50 parts by weight of polypropylene glycol (manufactured by Sumika Bayer Urethane Co., product number: Sumiphen 1703) as a polyol and MDI (manufactured by Sumika Bayer Urethane Co., product number: Sumidule 44V20) as polyisocyanate. A thermosetting urethane foam composite material was obtained in the same manner as in Example 1 except that 54 parts by weight was used. The glass fiber content in the obtained composite material was 18% by volume.

(Comparative Example 2) As a vinyl polymer, a copolymer of styrene and butyl acrylate (having a glass transition point of 80)
C.) was pulverized with a mill and 25 parts by weight of a sieve having a sieve of 0.5 mm square were prepared. Polypropylene glycol as a polyol (manufactured by Sumika Bayer Urethane Co.,
Product number: Sumiphen 1703) 50 parts by weight, MDI (manufactured by Sumika Bayer Urethane Co., product number: Sumidule 44V20) 54 parts by weight as polyisocyanate, water 0.3 parts by weight as a foaming agent, and foam stabilizer (Toray Dow) 0.3 parts by weight of product number: SRX295 manufactured by Corning Co., Ltd. were prepared and mixed vigorously to obtain an uncured thermosetting urethane foam raw material. 60 parts by weight of this raw material was placed in a mold, and glass roving (fiber diameter of 17 μm) 40
The mixture was sprinkled on parts by weight and foamed and cured in the same manner as in Example 1 to obtain a thermosetting urethane foam composite material. The glass fiber content in this composite material was 18% by volume.

(Comparative Example 3) A copolymer of styrene and butyl acrylate as a vinyl polymer (having a glass transition temperature of-
15 parts by weight), 50 parts by weight of polypropylene glycol (manufactured by Sumika Bayer Urethane Co., product number: Sumifene 1703) as a polyol, and 54 parts by weight of MDI (manufactured by Sumika Bayer Urethane Co., product number: Sumidule 44V20) as a polyisocyanate. And water as a foaming agent.
3 parts by weight and a foam stabilizer (manufactured by Toray Dow Corning, product number:
0.3 parts by weight of SRX295) were prepared and mixed to obtain an uncured thermosetting urethane foam raw material. 60 parts by weight of this raw material was sprinkled on 40 parts by weight of glass roving (element fiber diameter: 17 μm) drawn in the mold, and foamed and cured in the same manner as in Example 1 to prepare a thermosetting urethane foam composite. Got the material. The glass fiber content in this composite material was 18% by volume.

(Evaluation of Examples 1 and 2 and Comparative Examples 1 to 3)
The glass transition points of the vinyl polymers used in Examples 1 and 2 and Comparative Examples 1 to 3 were measured, and the vibration test of each thermosetting urethane foam composite material and the dispersed state of the vinyl polymer were performed as follows. evaluated. The results are shown in Table 1 below.

(1) Measurement of glass transition point of vinyl polymer Using a rheometrics viscoelasticity measuring instrument RSAII,
In the range of 20 ° C to + 80 ° C, the heating rate is 2 ° C / min and the strain is 0.
Tan δ was measured by the dual cantilever method under the conditions of 2% and 10 Hz, and the glass transition point was determined from the peak position.

(2) Vibration test Using a vibration tester manufactured by IMV, 23 ° C, frequency 200
The entire composite material was vibrated at 0 Hz and a vibration acceleration of 1 G, and the acceleration in the vibration direction on the surface of the composite material was measured by an acceleration pickup fixed to the surface of the sample material.
The smaller the acceleration, the better the resonance.

(3) Dispersion state of vinyl polymer The obtained composite material was immersed in liquid nitrogen and fractured, and then the cross section was observed with a scanning electron microscope.

[0056]

[Table 1]

In the composite material of Comparative Example 1, which is a structure used as a conventional railroad synthetic resin composite sleeper,
It can be seen that, while the vibration is amplified by the resonance phenomenon, the resonance phenomenon is suppressed in the composite materials of Examples 1 and 2. That is, since the resonance phenomenon is suppressed, it can be seen that when the composite material rail sleeper of the embodiment is used, it is possible to reduce track deviation and noise due to vibration. Also, in each of the composite materials of Comparative Examples 2 and 3, it is understood from the result of the vibration test that the resonance phenomenon cannot be suppressed and the vibration is amplified.

As is clear from the observation of the dispersed state of the vinyl polymer, in Comparative Examples 2 and 3, the vinyl polymer was not stable in shape and formed a continuous layer or separated from the cell wall. It exists, and it is speculated that the bending strength and durability against repeated load may be reduced. On the contrary,
In the composite materials of Examples 1 and 2, since the vinyl polymer particles exist as resin in the cell wall in a state of being separated from each other, it is considered that the bending strength and the durability against repeated load are improved.

(Example 3) Polytetramethylene glycol ("PTG2000" manufactured by Hodogaya Chemical Co., Ltd., average molecular weight 2)
000, hydroxyl value 56mgKOH / g, melting point 27 ° C) 6
0 parts by weight, polypropylene glycol ("P-700" manufactured by Asahi Denka Co., Ltd., average molecular weight 700, hydroxyl value 155)
10 parts by weight, polyether polyol ("SBU polyol 0517" manufactured by Sumika Bayer Urethane Co., hydroxyl group 4
75) A stable suspension obtained by vigorously mixing 30 parts by weight at room temperature was used as a polyol stock solution, and a polyisocyanate stock solution was polymetallic MDI (“Sumijour 44V20” manufactured by Sumika Bayer Urethane Co., NCO% = 31%).
55 parts by weight, 0.1 part by weight of water as a foaming agent, and 0.1 part by weight of dibutyltin laurate as a catalyst were vigorously mixed to obtain a thermosetting urethane stock solution having a crystalline polymer content of 41% by weight. 60 parts by weight of this thermosetting urethane stock solution was sprinkled on 40 parts by weight of E glass roving (17 micron monofilament aggregate) that had been placed in a mold, and the mixture was heated at 80 ° C. for 3 days.
It was foamed and hardened for 0 minutes to obtain a railway sleeper having a glass fiber content of 18%.

(Comparative Example 4) Polytetramethylene glycol ("PTG2000" manufactured by Hodogaya Chemical Co., Ltd., average molecular weight 2)
000, hydroxyl value 56mgKOH / g, melting point 27 ° C) 2
5 parts by weight, polypropylene glycol ("P-700" manufactured by Asahi Denka Co., Ltd., average molecular weight 700, hydroxyl value 155 m
gKOH / g) 35 parts by weight, polyether polyol (“SBU polyol 051” manufactured by Sumika Bayer Urethane Co., Ltd.
7 ", hydroxyl value 475 mgKOH / g) 40 parts by weight,
A stable suspension obtained by vigorous mixing at room temperature was used as a polyol stock solution, and as a polyisocyanate stock solution, a polymetallic MDI (Sumijour 4 manufactured by Sumika Bayer Urethane Co., Ltd.) was used.
4V20 ", NCO% = 31%) 78 parts by weight, water as a blowing agent 0.1 part by weight, and dibutyltin laurate 0.1 part by weight as a catalyst are vigorously mixed to give a crystalline polymer content of 15
A wt% thermosetting urethane stock solution was obtained. E-glass roving (17 micron monofilament aggregate) 4 in which 60 parts by weight of this thermosetting urethane stock solution was placed in a mold
It was sprinkled on 0 part by weight and foam-cured at 80 ° C. for 30 minutes to obtain a railway sleeper having a glass fiber content of 18%.

(Comparative Example 5) Polytetramethylene glycol ("PTG3000" manufactured by Hodogaya Chemical Co., Ltd., average molecular weight 3)
000, hydroxyl value 37mgKOH / g, melting point 30 ° C) 3
5 parts by weight, polypropylene glycol ("P-700" manufactured by Asahi Denka Co., Ltd., average molecular weight 700, hydroxyl value 115 m)
gKOH / g) 15 parts by weight, polyether polyol (“SBU polyol 051” manufactured by Sumika Bayer Urethane Co., Ltd.
7 ", hydroxyl value 475 mgKOH / g) 40 parts by weight,
A stable suspension obtained by vigorous mixing at room temperature was used as a polyol stock solution, and as a polyisocyanate stock solution, polymetallic MDI (Sumijour 4 manufactured by Sumika Bayer Urethane Co., Ltd.) was used.
4 V20 ", NCO% = 31%) 87 parts by weight, 0.1 parts by weight of water as a foaming agent, and 0.1 parts by weight of dibutyltin laurate as a catalyst were vigorously mixed to give a crystalline polymer content of 19
A wt% thermosetting urethane stock solution was obtained. E-glass roving (17 micron monofilament aggregate) 4 in which 60 parts by weight of this thermosetting urethane stock solution was placed in a mold
It was sprinkled on 0 part by weight and foam-cured at 80 ° C. for 30 minutes to obtain a railway sleeper having a glass fiber content of 18%.

(Evaluation of Example 3 and Comparative Examples 1, 4 and 5)
The railroad ties obtained in Example 3 and Comparative Examples 1, 4, and 5 were evaluated by measuring tan δ and performing the same vibration test as in Example 1. The results are shown in Table 2. Incidentally, tan
The measurement of δ was performed as follows. A part of railway sleepers is sampled and tested with a dynamic viscoelasticity tester: test temperature: -20 to
Tan δ at 0 to 50 ° C. was measured by the tensile method under the conditions of 80 ° C., temperature rising rate: 2 ° C./min, strain: 0.02%, and frequency: 10 Hz.

[0063]

[Table 2]

As is clear from Table 2, the railroad tie of Comparative Example 1 corresponding to the conventional railroad tie has the amplified resonance, whereas the railroad tie of Example 3 has such a resonance. The phenomenon is suppressed. In addition, the resonance phenomenon is not suppressed in the railroad sleepers of Comparative Examples 4 and 5. Further, in Example 3, since a sufficient amount of the crystalline polymer is compatible, the tan δ value in the room temperature region is significantly increased as compared with Comparative Example 1 containing no crystalline polymer. On the other hand, in Comparative Examples 4 and 5 in which the amount of the crystalline polymer was small, the increase was small and it is considered that the resonance phenomenon was not suppressed.

[0065]

In the railway sleeper of the present invention 1, the thermosetting urethane foam and the cell walls of the thermosetting urethane foam are dispersed in the form of particles apart from each other and have a glass transition point. Polymer particles in the range of 0 to 50 ° C. and long fibers dispersed in the thermosetting urethane foam so that the longitudinal direction is parallel to the longitudinal direction of the thermosetting urethane foam. Since the reinforcing material is included, the phenomenon of resonance is suppressed by the action of the vinyl polymer particles, whereby vibration and noise can be reduced. In addition, since the railroad sleeper according to the present invention is constructed by using the thermosetting urethane foam composite material, it can be easily installed in the same manner as the wooden sleeper, and is used for the branch portion having a large vibration. Even in such a case, the frequency of trajectory position correction can be reduced.

In the method for manufacturing a railway sleeper according to the second aspect of the present invention, a thermosetting urethane undiluted solution containing a polyol in which at least a part of the vinyl polymer is graft-polymerized and a polyisocyanate is used to form a thermosetting urethane foam. Since it is used as a raw material for this, the resonance phenomenon is suppressed, and vibration and noise can be reduced thereby, and the frequency of position correction of the track can be reduced even when used in a bifurcating part with large vibration. Rail sleepers can be manufactured.

The railroad sleeper of the present invention 6 is a railroad sleeper obtained by impregnating a thermosetting urethane stock solution into a long-fiber reinforcing material whose longitudinal directions are parallel to each other and thermally curing the same. The undiluted urethane solution contains a vinyl polymer having a glass transition point in the range of 0 to 50 ° C or a crystalline polymer having a melting point of 0 to 50 ° C in a proportion of 20 to 60% by weight based on the total amount of the resin. The mixture is a mixture, and after curing, the vinyl polymer or the crystalline polymer having a melting point of 0 to 50 ° C. is dispersed in a resin, and tan δ of a cured resin obtained by a dynamic viscoelasticity test is Since the value is 0.1 or more at 0 to 50 ° C., the phenomenon of resonance is suppressed by the action of the particles of the vinyl polymer or the crystalline polymer, whereby vibration and noise can be reduced. In addition, since the railroad sleeper according to the present invention is constructed by using the thermosetting urethane foam composite material, it can be easily installed in the same manner as the wooden sleeper, and is used for the branch portion having a large vibration. Even in such a case, the frequency of trajectory position correction can be reduced.

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Claims (8)

[Claims] 1. A thermosetting urethane foam and particles of the thermosetting urethane foam, which are dispersed in the cell wall of the thermosetting urethane foam apart from each other, and have a glass transition point of 0 to 50 ° C. A vinyl polymer particle and a long fiber reinforcing material dispersed in the thermosetting urethane foam so that the longitudinal direction is parallel to the longitudinal direction of the thermosetting urethane foam. Railroad sleepers that do. 2. The method of manufacturing a railway sleeper according to claim 1, wherein a thermosetting urethane stock solution comprising a polyol in which at least a part of the vinyl polymer is graft-polymerized and a polyisocyanate is thermoset. A method for manufacturing a railway sleeper, which is used as a raw material for forming a foamed urethane foam. 3. The method of manufacturing a railway sleeper according to claim 1, wherein at least a part of the vinyl polymer is graft-polymerized, and the vinyl polymer is not graft-polymerized. And a polyisocyanate-containing thermosetting urethane stock solution is used as a raw material for forming a thermosetting urethane foam. 4. The thermosetting urethane stock solution is a mixture containing a vinyl polymer having a glass transition point in the range of 0 to 50 ° C. in a proportion of 5 to 45% by weight based on the total amount of the resin. The method for manufacturing a railway sleeper according to claim 2 or 3, characterized in that. 5. The railway according to claim 2, wherein a long fiber is impregnated with a raw material for forming the thermosetting urethane foam, and then cured and foamed. Manufacturing method for sleepers. 6. A railroad sleeper obtained by impregnating a thermosetting urethane stock solution into a long fiber reinforcing material whose longitudinal directions are parallel to each other and thermosetting it, wherein the thermosetting urethane stock solution comprises:
It is a mixture containing a vinyl polymer having a glass transition point in the range of 0 to 50 ° C. or a crystalline polymer having a melting point of 0 to 50 ° C. in a proportion of 20 to 60% by weight with respect to the total amount of resin, and cured. Then, the vinyl polymer or the crystalline polymer having a melting point of 0 to 50 ° C. is dispersed in the resin, and the value of tan δ when the dynamic viscoelasticity test is performed on the resin cured product is 0 to 50.
Railway sleepers characterized by having a value of 0.1 or more at ℃. 7. The thermosetting urethane undiluted solution is a two-part curable type comprising a polyol undiluted solution and a polyisocyanate undiluted solution, and the polyol undiluted solution has an average molecular weight of 700 to 4500 having a crystalline polymer chain in the molecule. Polyol A and a polyol B having a polymer chain having a structure similar to the polymer chain in the molecule and having an average molecular weight of 300 to 1500
And a hydroxyl value of 400 mg with no polymer chain in the molecule
KOH / g or more of the polyol C, wherein the polyol A is 30 to 80% by weight of the total polyol stock solution, and the polyol B is 5 to 35% of the total polyol stock solution.
% By weight of the polyol C is 5 to 5% of the whole polyol stock solution.
The rail sleeper according to claim 6, which is 45% by weight. 8. The long fiber reinforcing material is 10 to 25 in total.
The railroad ties according to claim 1, 6 or 7, characterized in that the railroad ties include a capacity%.