JP2002327439A - Execution method of filling and method of manufacturing civil engineering polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an execution method capable of quickly and easily constructing a lightweight filling having excellent strength and durability and having light load influenced on the environment in a filling construction site and to provide a method of manufacturing a civil engineering polyurethane foam capable of quickly and easily forming a polyurethane foam having excellent strength and durability in an optional size and shape and having lightweight load influenced on the environment in a place to be used. SOLUTION: Liquid for material use containing a polyisocyanate, an active hydrogen compound and a foaming agent is used, and the execution method of the filling formed in the filling construction site containing a foam layer consisting of the polyurethane foam uses a carbon dioxide in a supercritical, subcritical or liquid state as the foaming agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for embankment embankment and a method for producing a polyurethane foam for civil engineering.

[0002]

2. Description of the Related Art Conventionally, road construction, site preparation or embankment, etc.
When embankment is formed for the purpose of
Method has been adopted. However, with this method,
Load of sand, earth and sand that constitute soil (mass per unit volume)
Is about 1.4 to 2.1 tf / m ^ThreeDegree) is large
Therefore, settlement may occur in the lower ground of the embankment,
Part of the embankment itself close to
There was a problem of spreading. In particular, embankment construction sites
If the place is on difficult ground composed of cohesive soil,
In case of landslide such as steep terrain,
In places where construction conditions are severe, it is formed on the above ground
Embankment stability problems had arisen.

As a method for taking measures against the above problem, there is an EPS method using an ultralight foam such as styrene foam as a material for embankment or wall. In the EPS method, the embankment is composed of a foam block having a density of about 1/100 of earth and sand or concrete. Therefore, the lightweight construction does not require reinforcement of the foundation ground, and in this respect, the workability is excellent. Also excellent in later self-sustainability, water resistance and heat insulation.

[0004] Such an EPS method is disclosed, for example, in JP-A-55-129594, JP-A-62-45801 and JP-A-7-34471. Japanese Patent Application Laid-Open No. 5-148839 discloses an EPS method in which a foamed polyurethane resin is injected into a gap between the ground and a layer composed of an EPS block.

Further, Japanese Patent Application Laid-Open No. 43620/1994 discloses a method of constructing a lightweight embankment by injecting a foam into a mold. JP-A-64-66316 discloses a lightweight embankment construction method using water as a foaming agent when producing a polyurethane foam block. Also,
Japanese Patent Application Laid-Open No. Hei 8-60665 discloses a lightweight polyurethane foam block made of an open-celled water-foamed urethane resin having improved water permeability.

[0006]

However, in the construction methods described in JP-A-55-129594, JP-A-62-45801 and JP-A-7-34471, an EPS having a single standard shape is used. Block (typically 1m
In order to adapt to various shapes that differ depending on the site, in order to produce, transport, and construct a rectangular parallelepiped foam block with a size of about 2 m × 0.5 m) at the factory, processing the block at the site, There is a problem that it takes time and effort to cut it.

In addition, according to the EPS method, the stacked blocks are not integrated and fixed, but a gap is formed between the blocks. Therefore, when a load is applied or when an earthquake occurs, the blocks are blocked. There is a problem that cracks and the like occur in the upper roadbed due to the occurrence of deviation. In addition, the current EPS method has a problem in that the number of transportations required to transport a required amount of blocks to the embankment construction site increases, and the transportation cost increases. In addition, the blocks must be temporarily placed before construction, and it is sometimes difficult to secure the space due to the topography.

Further, the EPS method described in Japanese Patent Application Laid-Open No. 5-148839 has a problem that the foam cannot be sufficiently injected. Furthermore, the EPS method described in Japanese Patent Application Laid-Open No. 1-343620 requires time and labor for laying and removing a mold to inject a foam into a certain mold, and when the mold has a complicated shape. Has a problem that the foam cannot be sufficiently injected.

Further, the methods described in JP-A-64-66316 and JP-A-8-60665 are a method of constructing a lightweight embankment by laminating polyurethane foam blocks. Insufficiently, when the top load was large, there was a problem in the stability of the structure.

Furthermore, in the case of the methods described in JP-A-64-66316 and JP-A-8-60665, a large amount of water as a foaming agent must be used to obtain a polyurethane foam block. When it is necessary to form blocks by stacking several layers continuously, the reaction heat generated by the reaction between water and isocyanate increases, causing cracks (cracks) inside the blocks and heat accumulation of blocks such as burns. There has been a problem that a defect that causes quality deterioration occurs. In addition, since the viscosity of the raw material liquid for forming the block is high, a mixing defect occurs, the polyurethane foam constituting the block has an uneven cell shape, and the mechanical strength of the block is reduced. . Further, when a large amount of water is used for weight reduction, an excessive urea bond is formed in the polyurethane foam constituting the block, and the foam becomes brittle.

The present invention has been made in view of the above-mentioned problems of the prior art, and enables a quick and easy construction of a lightweight embankment having excellent strength and durability at an embankment construction site. A method for embankment embedding that has a small impact on the environment, and a polyurethane foam having excellent strength and durability can be quickly and easily formed in an arbitrary size and shape at a place of use, and the impact on the environment can be increased. It is an object of the present invention to provide a method for producing a polyurethane foam for civil engineering having a small particle size.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above-mentioned object, and as a result, the present invention has found that when a polyurethane foam is produced at a construction site of an embankment, it is used as a foaming agent. By using carbon dioxide in a critical state, subcritical state or liquid state, a lightweight polyurethane foam with excellent strength and durability can be obtained in any shape and size, while reducing the load on the environment compared to the past. They have found that they can be manufactured quickly and easily and arrived at the present invention.

That is, the present invention relates to a method for constructing an embankment using a raw material liquid containing a polyisocyanate, an active hydrogen compound and a foaming agent to form an embankment including a foam layer made of polyurethane foam at an embankment construction site. The present invention also provides a method for embankment using carbon dioxide in a supercritical state, a subcritical state, or a liquid state as a foaming agent.

According to the embankment construction method of the present invention, carbon dioxide in a supercritical state, subcritical state, or liquid state is used as a foaming agent, so that the load on the environment during embankment construction can be reduced as compared with the conventional method. . In addition, since the embankment construction method of the present invention is a method of producing a polyurethane foam at an embankment construction site, a factory facility and a transport facility for producing a polyurethane foam foam block are unnecessary, and the conventional EPS method is not used. Excellent workability compared to the case.

In the method for embankment embankment of the present invention, since the polyurethane foam constituting the embankment can be formed continuously and in an integrated state, a highly rigid lightweight embankment can be formed very easily and simply. Can be built. In addition, the embankment construction method of the present invention can significantly shorten the construction period. Further, the embankment construction method of the present invention is also excellent in terms of safety, large-scale construction such as structural protection, small-scale construction (for example, backfill applications) can be supported .

The present invention also provides a raw material liquid preparation step for preparing a raw material liquid containing a polyisocyanate, an active hydrogen compound and a foaming agent, and a method for reacting a polyisocyanate with an active hydrogen compound using the raw material liquid. A foam forming step of forming a polyurethane foam by advancing the foaming and curing of the obtained polyurethane, and using carbon dioxide in a supercritical state, a subcritical state, or a liquid state as a blowing agent, The present invention provides a method for producing a polyurethane foam for civil engineering.

In the method for producing a polyurethane foam for civil engineering of the present invention, carbon dioxide in a supercritical state, a subcritical state or a liquid state is used as a blowing agent, so that the load on the environment during the production of the polyurethane foam is reduced as compared with the conventional method. can do.

In the method for producing a polyurethane foam for civil engineering according to the present invention, since carbon dioxide in at least one of a supercritical state, a subcritical state, and a liquid state is used as a blowing agent, the cell size in the polyurethane foam is reduced. It is easy to make the cell uniform, and when the cell size is approximated to a sphere, the average diameter can be made very small, for example, 5 to 300 μm. Therefore, the cell density in the polyurethane foam can be easily increased, and a high-quality polyurethane foam having excellent strength and durability can be easily manufactured.

On the other hand, a polyurethane foam produced by a conventional polyurethane foam production method using hydrochlorofluorocarbon, water, or a mixture of water and hydrofluorocarbon as a foaming agent is a cell size in the polyurethane foam. Is non-uniform, and when the cell size is approximated to a sphere as described above, the average diameter is usually as large as 10 to 1000 μm.

In the present invention, the term "subcritical carbon dioxide" refers to liquid carbon dioxide whose pressure is equal to or higher than the critical pressure of carbon dioxide and whose temperature is lower than the critical temperature, or that the pressure is carbon dioxide. Carbon dioxide in a liquid state that is less than the critical pressure and the temperature is equal to or higher than the critical temperature, or
When the temperature and the pressure are both lower than the critical point but close to the critical point, specifically, the temperature is 20 ° C. or more and the pressure is 5 ° C.
Indicates carbon dioxide of MPa or more. Further, “liquid state carbon dioxide” refers to liquid state carbon dioxide other than the above-mentioned subcritical state.

In the present invention, a fine cell refers to a cell having a small cell size and a uniform size.

Further, in the present invention, "active hydrogen compound"
Is a compound having active hydrogen active on polyisocyanate, for example, polyether polyol,
Shows polyester polyols and the like.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the method for embankment embankment and the method for producing a polyurethane foam for civil engineering according to the present invention will be described in further detail.

The method for producing a polyurethane foam of the present invention mainly comprises a raw material liquid preparation step for preparing a raw material liquid containing the above-mentioned polyisocyanate, an active hydrogen compound and a blowing agent, and a raw material liquid prepared in the raw material liquid preparation step. A foam forming step of forming a polyurethane foam by causing a polyisocyanate and an active hydrogen compound to react with each other using a liquid, and promoting the foaming and curing of the obtained polyurethane.

FIG. 1 is a system diagram showing an example of a basic configuration of an apparatus for producing a polyurethane foam based on the method for producing a polyurethane foam for civil engineering of the present invention. The polyurethane foam manufacturing apparatus 1 shown in FIG. 1 mainly includes a liquefied carbon dioxide cylinder 10, a heat exchanger 20, a compression metering pump 30, an active hydrogen compound storage container 50,
Chiller 60, compression metering pump 70, static mixer 80, heater 90, heating hose 100, polyisocyanate storage container 110, compression metering pump 1
20, a heater 130, a heating hose 140, and a gun 150 having a spray nozzle.

The structure of the polyurethane foam manufacturing apparatus 1 shown in FIG. 1 will be described in more detail. The liquefied carbon dioxide cylinder 10 and the heat exchanger 20 are connected via a fluid line L10. It is connected to a heat transfer tube L20 provided inside the exchanger 20.

A chiller 60 is connected to the heat exchanger 20 via a fluid line L60 and a fluid line L61.
The brine in the chiller 60 can be circulated between the heat exchanger 20 and the chiller 60. That is, the brine in the chiller 60 is supplied to the heat exchanger 20 via the fluid line L60, and the heat transfer tube L2
The liquefied carbon dioxide passing through the inside of the heat transfer tube L0 and the brine passing outside the heat transfer tube L20 exchange heat. Then, the brine after the heat exchange is returned to the chiller 60 via the fluid line L61 and adjusted to a predetermined temperature.

Further, the heat exchanger 20 and the compression metering pump 30
Are connected via a fluid line L21, so that liquefied carbon dioxide that has undergone heat exchange in the heat exchanger 20 is supplied into the compression metering pump 30. The compression metering pump 30 has a piston 31, and the discharge amount and pressure of liquefied carbon dioxide can be arbitrarily adjusted by adjusting the stroke length of the piston 31.

Further, a chiller 60 is connected to a fluid line L60 on the outer peripheral portion (not shown) of the cylinder of the compression metering pump 30.
A fluid line L62 branched from the fluid line L61
And a fluid line L63 connected to the chiller 60 so that the brine in the chiller 60 can be circulated between the compression metering pump 30 and the chiller 60.

That is, the brine in the chiller 60 is supplied to the outer circumference of the cylinder of the compression metering pump 30 via the fluid line L62, and the liquefied carbon dioxide in the compression metering pump 30 and the brine passing through the outer circumference of the cylinder exchange heat. Configuration. Then, the brine after the heat exchange is returned to the chiller 60 via the fluid line L63 and the fluid line L61, and is adjusted to a predetermined temperature. Thereby, in the compression metering pump 30, it is possible to prevent the liquefied carbon dioxide from evaporating during the suction stroke of the piston 31.

On the other hand, an active hydrogen compound storage container 50 containing an active hydrogen compound such as a polyol which is a raw material of the polyurethane foam is connected to a compression metering pump 70 via a fluid line L50. This compression metering pump 70
Similarly to the compression metering pump 30, the discharge amount and pressure of the active hydrogen compound can be arbitrarily adjusted by adjusting the stroke length of a piston (not shown). The compression metering pump 70 is connected to the static mixer 80 via the fluid line L70. As a result, the active hydrogen compound can be supplied to the static mixer 80 while being adjusted to a predetermined amount and pressure.

The compression metering pump 30 is connected to the fluid line L
30 is connected to the fluid line L70. The liquefied carbon dioxide discharged from the compression metering pump 30 after being adjusted to a predetermined amount merges with the active hydrogen compound in the fluid line L70 and is supplied to the static mixer 80. Then, in the static mixer 80, the liquefied carbon dioxide and the active hydrogen compound are sufficiently mixed.

The static mixer 80 has a fluid line L
It is connected to a heater 90 via 80. The heater 90 is for heating a mixture of the active hydrogen compound and the liquefied carbon dioxide mixed by the static mixer 80 to a predetermined temperature. By heating with the heater 90, the state of carbon dioxide in the mixture of the active hydrogen compound and carbon dioxide can be controlled to any of a supercritical state, a subcritical state, and a liquid state.

The heater 90 is connected to the heating hose 100 via a fluid line L90.
00 is further connected to a gun 150. As a result, the mixture of carbon dioxide and the active hydrogen compound in the supercritical state, subcritical state, or liquid state in the heater 90 is supplied to the gun 150. Here, the heating hose 100 is prepared in the gun 150 by heating the mixture of carbon dioxide and active hydrogen compound in a supercritical, subcritical, or liquid state before being introduced into the gun 150. It is provided to maintain the temperature and pressure of the raw material liquid.

A polyisocyanate storage container 110 containing polyisocyanate, which is another raw material of the polyurethane foam, is connected to a compression metering pump 120 via a fluid line L110. Like the compression metering pump 30, the compression metering pump 120 is also configured such that the discharge amount and pressure of the polyisocyanate can be arbitrarily adjusted by adjusting the stroke length of a piston (not shown). The compression metering pump 120 is connected to the heater 130 via the fluid line L120.
Further, the heater 130 is connected to a heating hose 140 via a fluid line 140, and the heating hose 140 is further connected to a gun 150.

Accordingly, the polyisocyanate can be supplied to the gun 150 while being adjusted to a predetermined amount, temperature and pressure. Here, the heating hose 140 is connected to the heating hose 10.
The heating is performed before the polyisocyanate is introduced into the gun 150 in the same manner as in the case of 0 to maintain the temperature and pressure of the raw material liquid prepared in the gun 150.

Here, the heating hose 14 is provided in the gun 150.
And the heating hose 10
A space (not shown) such as a mixing chamber for mixing a mixture of carbon dioxide and an active hydrogen compound in a supercritical state, a subcritical state, or a liquid state flowing from zero.
Is provided.

The components of the polyurethane foam production apparatus 1 described above are operated as follows based on the raw material liquid preparation step and the foam formation step of the polyurethane foam production method of the present embodiment.

In the raw material liquid preparation step, first, the open / close valves 62 and 64 of the fluid line L60 of the chiller 60 are opened, and the brine is circulated through the heat exchanger 20 and the compression metering pump 30. Further, the operation of the compression metering pump 30, the compression metering pump 70, the compression metering pump 120, the static mixer 80, the heater 90, and the heater 130 is started. Next, after the heat exchanger 20, the compression metering pump 30, the heater 90, and the heater 130 are stabilized at a predetermined temperature,
Open / close valve (not shown) of the active hydrogen compound storage container 50 and open / close valve (not shown) of the polyisocyanate storage container 110
And the open / close valve 1 of the liquefied carbon dioxide cylinder 10 kept at room temperature
Open 2.

Here, the liquefied carbon dioxide in the liquefied carbon dioxide cylinder 10 is supplied to the heat exchanger 20 via the fluid line L10 due to the internal pressure of the liquefied carbon dioxide cylinder 10. Here, in the heat exchanger 20, the temperature of the liquefied carbon dioxide is reduced to -10 to 10 by the brine from the chiller 60.
C., preferably adjusted to cool to 0.degree.

Then, the liquefied carbon dioxide that has flowed out of the heat exchanger 20 is sent to the compression metering pump 30, adjusted to a predetermined amount and pressure, and discharged into the fluid line L30. In addition,
Here, too, the temperature of the liquefied carbon dioxide is maintained at -10 to 10C, preferably 0C, by the brine from the chiller 60.

On the other hand, by being suctioned by the compression metering pump 70, the active hydrogen compound in the active hydrogen compound storage container 50 is supplied to the compression metering pump 70 via the fluid line L50 and adjusted to a predetermined amount and pressure. Fluid line L7
Discharged within 0. The liquefied carbon dioxide discharged into the fluid line L30 is supplied into the fluid line L70, and is supplied to the static mixer 80 together with the active hydrogen compound.
And mixed well.

Further, the mixture of the active hydrogen compound and the liquefied carbon dioxide sent from the static mixer 80 into the fluid line L80 is introduced into the heater 90, and the liquefied carbon dioxide in the mixture is converted into a supercritical state and a subcritical state. The state is either a state or a liquid state. And the supercritical state,
The mixture of the carbon dioxide and the active hydrogen compound in either the subcritical state or the liquid state is supplied into the gun 150 via the fluid line L90 and the heating hose 100.

On the other hand, by being sucked by the compression metering pump 120, the polyisocyanate in the polyisocyanate storage container 110 is supplied to the compression metering pump 120 via the fluid line L110, and is adjusted to a predetermined amount and pressure to adjust the fluid. The liquid is discharged into the line L120. The polyisocyanate discharged into the fluid line L120 is set to a predetermined temperature and pressure in the heater 140, and is supplied to the gun 150 via the fluid line L130 and the heating hose 140. Then, in the mixing chamber of the gun 150, the polyisocyanate flowing from the heating hose 140 and the supercritical state flowing from the heating hose 100,
A raw material liquid is prepared by mixing a mixture of carbon dioxide and an active hydrogen compound in a subcritical state or a liquid state.

Here, the pressure of the raw material liquid used in the present invention is not particularly limited, and is determined by the composition of the raw material liquid, the properties of the blowing agent such as carbon dioxide in a supercritical state, and the viscosity of the raw material liquid. However, the pressure is preferably equal to or higher than the critical pressure of carbon dioxide in a supercritical state. For example, when using carbon dioxide in a supercritical state as a blowing agent, the pressure is preferably 5.0 MPa to 20 MPa,
More preferably, it is 7.2 MPa to 15 MPa.

The raw material liquid temperature used in the present invention is:
The temperature may be lower than the temperature at which the components in the raw material liquid thermally decompose, and are determined by the type and concentration of the components in the raw material liquid such as the foaming agent. The lower limit of the temperature of the raw material liquid is 10 ° C., and the upper limit of the temperature of the raw material liquid is selected depending on the thermal stability of the components in the raw material liquid. In this case, the preferable temperature of the raw material liquid is 20 to
90 ° C., more preferably the temperature of the raw material liquid is 31 ° C. to 5
0 ° C.

In the present invention, the blowing agent is carbon dioxide in a supercritical state, a subcritical state, or a liquid state, but another blowing agent may be used in addition to carbon dioxide in these states. In the present invention, a blowing agent that can be used in combination with carbon dioxide in these states exhibits an effect as a diluent for polyols and the like in addition to the effect as a blowing agent, and is excellent in workability and workability. If it is, there is no particular limitation. Examples include alkyl alkanoates, dialkyl ethers, hydrofluorocarbons, fluorocarbons, and water that reacts with isocyanate groups to generate carbon dioxide. Further, a fluid in a supercritical state, subcritical state or liquid state other than carbon dioxide may be used in combination with carbon dioxide in a supercritical state, subcritical state or liquid state as another blowing agent.

In particular, in the present invention, it is preferable to use carbon dioxide and water in a supercritical state, a subcritical state or a liquid state as a foaming agent from the viewpoints of appearance, density and compressive strength of the polyurethane foam. Here, when the amount of water used together with carbon dioxide is small, it is necessary to increase the amount of carbon dioxide in a supercritical state, a subcritical state, or a liquid state in order to compensate for the small amount of water. It tends to be difficult to obtain a smooth flat polyurethane foam. Also, when the amount of water used together with carbon dioxide increases, the density of the polyurethane foam tends to decrease, and the compressive strength tends to decrease.

[0049] Note that the compression strength of the polyurethane foam as a road embankment is preferably 4N / cm ^2, is preferably 6N / cm ^2. In this case, the amount of water is preferably 3 to 5% by mass based on the total mass of the raw material liquid. If the amount of water is less than 3% by mass with respect to the total mass of the raw material liquid, the density of the polyurethane foam increases and the material cost increases. On the other hand, when the blending amount of water exceeds 5% by mass with respect to the total mass of the raw material liquid, the density of the polyurethane foam becomes low and the compressive strength may be insufficient.

In the polyurethane foam manufacturing apparatus shown in FIG. 1, water is stored in the active hydrogen compound storage container 50.
It is preferable to mix them in advance.

The supercritical fluid behaves like a liquid, has a high density close to a liquid, and has a lower viscosity than a liquid. Therefore, a supercritical fluid has a higher diffusion coefficient than a liquid, and has a high dissolving capacity as a solvent and is a high-performance reaction medium. Therefore, carbon dioxide in a supercritical state used in the present invention can rapidly dissolve a high molecular weight substance.

In view of the above, in the present invention, the blowing agent is carbon dioxide in a supercritical state, a subcritical state or a liquid state, but it is more preferable to use carbon dioxide in a supercritical state. In this case, since the carbon dioxide in the supercritical state lowers the viscosity of the raw material liquid, good workability is provided, and a polyurethane foam having uniform fine cells inside can be obtained. Carbon dioxide in a supercritical state is characterized in that it has a low critical temperature, is non-toxic, is nonflammable, and has a low cost as compared with a fluid that can be a blowing agent such as xenon and krypton. Further, the solubility of carbon dioxide in a supercritical state is almost the same as that of aliphatic hydrocarbons (for example, butane, pentane, hexane) which have been conventionally used as a foaming agent. There has been a concern that aliphatic hydrocarbons may be released into the air during foaming and increase flammability and explosiveness. However, since carbon dioxide is a non-flammable, non-toxic, and environmentally friendly blowing agent, the use of carbon dioxide in a supercritical state is useful from a safety viewpoint.

When carbon dioxide in a supercritical state is used as a blowing agent, the amount of the carbon dioxide is selected depending on the final target value of the density of the polyurethane foam and the viscosity of the raw material liquid. It is preferably from 0.5 to 30% by mass, more preferably from 1 to 10% by mass. By doing so, the viscosity of the raw material liquid at the foaming temperature can be easily adjusted to a viscosity suitable for forming a polyurethane foam. If the amount of supercritical carbon dioxide used in this way is used, the supercritical carbon dioxide in the raw material liquid discharged from the gun 150 causes adiabatic expansion instantaneously, and at the same time, rapidly cools the foam. Promotes stabilization of cell nuclei and contributes to stable foam cell shape and foam quality stability

Here, when the amount of supercritical carbon dioxide used exceeds 30% by mass based on the total mass of the raw material liquid, the raw material liquid contains a polyol (active hydrogen compound) and supercritical carbon dioxide. May separate into phases. On the other hand, if the amount of carbon dioxide in the supercritical state is less than 0.5% by mass based on the total mass of the raw material liquid, it is necessary to increase the amount of another blowing agent, and the effect of the present invention may not be exhibited. There is.

From the viewpoint of preventing the raw material liquid from separating into two phases as described above, the solubility of the raw material liquid components such as polyisocyanate and active hydrogen compound in supercritical carbon dioxide before use is measured. And a suitable raw material liquid component may be selected in advance and used, or a modifier may be used to increase the compatibility and solubility of the raw material liquid component with respect to carbon dioxide in a supercritical state. Such a modifier may be used in the case where carbon dioxide in a liquid state or subcritical state is used as a blowing agent in addition to carbon dioxide in a supercritical state. The dissolving power of carbon dioxide in a subcritical state or a supercritical state can be adjusted by using a modifier capable of changing compatibility, for example, an optional surfactant or a compatibilizer.

When the above surfactants and compatibilizers are added to the raw material liquid together with carbon dioxide in a supercritical state, subcritical state or liquid state and used, the amount of the surfactants and compatibilizers used is limited to the amount of the raw material liquid. Is preferably 0.1 to 30% by mass based on the total mass of the polymer. Foam stabilizers can also be effective modifiers. Therefore, it has a suitable viscosity (for example, 50 to 3000 mPa · s at 25 ° C.) to obtain a uniform raw material liquid that can be easily discharged through the mixing chamber of the gun 150.
adjusted to s). If an excessive amount of carbon dioxide deviates from the desired viscosity of the raw material liquid, a large amount of carbon dioxide is volatilized or released from the raw material liquid, and a polyurethane foam having sufficient strength and durability may not be obtained. By adjusting the viscosity of the raw material liquid to an appropriate value, a reaction in the unreacted raw material liquid remaining at the time of application to the building body provides a uniform polyurethane foam having a uniform distribution of internal cells and smoothness.

In the present invention, the raw material liquid for forming the polyurethane foam only needs to contain at least a polyisocyanate, an active hydrogen compound and a foaming agent. For example,
A foam stabilizer, a flame retardant, a viscosity reducing agent, and the like may be contained. In the polyurethane foam manufacturing apparatus shown in FIG. 1, the catalyst is preferably mixed in the active hydrogen compound storage container 50 in advance.

Examples of the above polyisocyanates include, for example, aromatic polyisocyanates such as 2,4′-diphenyl ether diisocyanate, 4,4′-diphenyl ether diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate,
4,6-dimethyl-1,3-phenylene diisocyanate, 4,4′-dibenzyl diisocyanate, 9,10
Anthracene diisocyanate, 3,3′-dimethyl-4,4′-diphenyl diisocyanate, xylylene diisocyanate, 2,6′-dimethyl 4,4′-diphenyl diisocyanate, xylylene diisocyanate, 2,4′-diphenylmethane diisocyanate,
4,4'-diphenylmethane diisocyanate and the like.

As the aliphatic diisocyanate,
Examples include tetramethylene diisocyanate and hexamethylene diisocyanate. Further, as the alicyclic diisocyanate, isophorone diisocyanate, hydrogenated TDI (toluene diisocyanate), hydrogenated M
DI (diphenylmethane diisocyanate) and the like. Further, the aromatic polyisocyanate, aliphatic diisocyanate or alicyclic diisocyanate in which a part of the isocyanate group is modified to urethane and / or urea may be used, and a part of the isocyanate group may be buret, allophanate, Those modified with carbodiimide, oxaziridone, acid, imide and the like may be used.

Further, among the above, the polyisocyanate is preferably an MDI-based polyisocyanate, and more preferably a polymethylene polyphenyl polyisocyanate represented by the following formula (1). In the following formula (1), n represents an integer of 0 to 8. Further, even when the polymethylene polyphenyl polyisocyanate represented by the following formula (1) is used, at least one of the above polyisocyanates may be used in combination.

Embedded image

Examples of active hydrogen compounds active against polyisocyanates include ethylene glycol, propanediol, butanediol, diethylene glycol, dipropylene glycol, tetramethylene glycol, hexamethylene glycol, cyclohexanedimethanol, bisphenol A, Methyl-1,5-pentanediol, glycerin, trimethylolpropane,
Pentaerythritol, puffed rose, glucose,
At least one compound having an active hydrogen such as fructose sorbitol and methyl glycooxide is exemplified. Further, for example, as the other compound having active hydrogen, at least one of amines such as ethylenediamine, propylenediamine, diethylenetriamine, toluenediamine, metaphenylenediamine, diphenylmethanediamine, xylylenediamine and the like can be mentioned. .

Further, a polyether polyol may be used as the active hydrogen compound. As the polyether polyol, for example, a monomer such as an alkylene oxide is known using at least one of the active hydrogen compounds exemplified above as an initiator. And those obtained by addition polymerization according to the above method. The monomers used for the addition polymerization reaction include ethylene oxide, propylene oxide, glycidyl ether, methyl glycidyl ether, t-butyl glycidyl ether, phenyl glycidyl ether and the like.

As the active hydrogen compound, a polyester polyol may be used. Examples of the polyester polyol include ethylene glycol, propanediol, butanediol, diethylene glycol, dipropylene glycol, trimethylene glycol, tetramethylene glycol, and hexamethylene glycol. Glycol, decamethylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, at least one of compounds having at least two hydroxyl groups such as bisphenol A One and, for example, adipic acid, malonic acid, succinic acid, tartaric acid, pimelic acid, sebacic acid, oxalic acid, phthalic acid, terephthalic acid, azelaine , Trimellitic acid, glutaconic acid, alpha-hydromuconic acid, beta-diethyl succinimide acid,
Examples include those produced by a known method using at least one compound having at least two or more carboxyl groups such as hemimelitic acid, 1,4-cyclohexanedicarboxylic acid, and the like.

Further, in addition to the above-mentioned polyester polyols, polyester polyols produced by transesterification of a polyalkylene terephthalate polymer with a low molecular weight diol can also be used. In addition, as a low molecular diol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, butanediol, glycerol, trimethylolpropane, cyclohexane dimethanol and the like can be mentioned.

In the present invention, the isocyanate index in the raw material liquid is preferably 0.95 to 2.0. Here, the isocyanate index indicates a blending equivalent ratio of the polyisocyanate and the active hydrogen group-containing compound (isocyanate group / active hydrogen group equivalent ratio). If the isocyanate index is less than 0.95, the resulting polyurethane foam may have low compressive strength. On the other hand, when the isocyanate index exceeds 2.0, unreacted polyisocyanate tends to remain in a usual urethane-forming catalyst. Further, from the same viewpoint as above, the isocyanate index in the raw material liquid is more preferably from 1.0 to 1.5.

The catalyst for promoting the urethanization reaction between the polyisocyanate and the active hydrogen group-containing compound is not particularly limited, and for example, a known catalyst can be used.
For example, tin compounds such as dibutyltin acetate, dibutyltin dilaurate, metal halides such as chloride, zinc chloride, zinc bromide, tin chloride, triethylenediamine, triethylamine, tripropylamine, tetramethylhexamethylenediamine, pentamethyldiethylenetriamine And amine compounds such as trimethylaminoethylpiperazine, N-methylmorpholine, N-ethylmorpholine and dimethylcyclohexylamine. In addition, known quaternary ammonium salt compounds, trimerization catalysts and the like can be mentioned, and these alone or in combination can be used.

The foam stabilizer to be contained in the raw material liquid is not particularly limited. For example, any foam stabilizer which is effective in producing a rigid polyurethane foam can be used. For example, a polyoxyalkylene-based foam stabilizer such as polyoxyalkylene alkyl ether or a silicone-based foam stabilizer such as organosiloxane may be used.

Next, the foam forming step will be described.
In the foam forming step, a polyol component (active hydrogen compound) containing a foaming agent is mixed in the mixing chamber of the gun 150.
And the polyisocyanate component are mixed and discharged onto the body, so that the reaction between the polyisocyanate and the active hydrogen compound proceeds to form polyurethane, and at the same time, a foaming agent forms a cell (cell) structure, and As the curing proceeds, a polyurethane foam is formed on the skeleton. Here, the skeleton is a concrete retaining wall, a ground, a nonwoven fabric or a resin layer laid (constructed) on the ground.

Here, the raw material liquid 160 released from the gun 150 is cooled by the cooling effect of carbon dioxide in a supercritical state, a subcritical state or a liquid state used as a foaming agent, before the temperature reaches the temperature of the external atmosphere before reaching the body. , Or rapidly below. Therefore, in the conventional method for producing a foam of the type in which the raw material liquid is heated, a large amount of the foaming agent is lost due to the volatility of the foaming agent used. By the above-mentioned cooling effect, cell nuclei in the polyurethane foam are formed stably, and at the same time, most of the volatile foaming agent remains in the foam cells, and the foam cell foamed into the frame is reduced in size, and the foam is foamed. Helps smoothness and bubble stability. In addition, due to the fine cell size, a tougher and lighter polyurethane foam can be obtained. In addition,
The distance from the gun 150 to the body is not particularly limited, but is generally preferably 100 mm to 2000 mm from the viewpoint of workability such as mist diffusion.

The method for producing a polyurethane foam of the present invention can be applied to backfilling, self-supporting walls, and the like, in addition to embankment described later.

Next, the embankment construction method of the present invention will be described. The embankment construction method of the present invention uses a raw material liquid containing a polyisocyanate, an active hydrogen compound, and a blowing agent,
An embankment construction method for forming an embankment including a foam layer made of polyurethane foam at an embankment construction site,
As long as it is a method using carbon dioxide in a supercritical state, a subcritical state or a liquid state as a blowing agent, other construction procedures and conditions such as construction place are not particularly limited, but in the embankment construction method of the present invention, It is preferable to use a polyurethane foam produced according to the above-described method for producing a polyurethane foam of the present invention for a foam layer.

Since the apparatus for producing a polyurethane foam based on the method for producing a polyurethane foam of the present invention as shown in FIG. 1 can be constructed compactly, it is lightweight at the embankment construction site and has excellent strength and durability. Embankments can be built quickly and easily. In addition, the load on the environment during construction can be reduced as compared with the related art. Further, the construction period can be significantly reduced.

FIG. 2 is a schematic sectional view showing an example of the structure of an embankment formed based on the embankment construction method of the present invention.
Hereinafter, a method of constructing the embankment 2 shown in FIG. 2 will be described.

First, the slope F300 of the steep ground 300
Next, a retaining wall 220 made of a metal plate, a concrete plate or the like is constructed. Next, for example, a polyurethane foam raw material liquid is injected into a gap formed between the inclined surface F300 and the retaining wall 220 using the polyurethane foam manufacturing apparatus 1 shown in FIG. Is formed. As a method for forming the foam layer 200, a method in which layers having a thickness of about 30 to 100 mm are sequentially laminated from the lower side close to the ground in order to prevent cracks from occurring is preferable. Next, on the upper surface of the foam layer 200, the inclined surface F3
The concrete pavement (not shown) is laid over 00, and asphalt is laid thereon to complete the paved road 230. At this time, anchor 25
0 is connected, and the retaining wall 220 is reinforced by embedding the anchor 250 in the ground 300.

A polyurethane coating layer may be formed between the foam layer 200 made of polyurethane foam and the inclined surface F300 if necessary. Further, since the foam layer 200 made of polyurethane foam has no water permeability, a drain passage (not shown) may be provided to drain rainwater flowing along the inclined surface F300. (Not shown) may be provided between the foam layer 200 and the inclined surface F300. Further, an anchor (not shown) is also connected to the retaining wall 220, and the anchor is connected to the ground 3
The retaining wall 220 may be reinforced by embedding it in the inside.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments.

For example, in the above embodiment, the case where supercritical, subcritical or liquid carbon dioxide serving as a foaming agent is mixed into the active hydrogen compound prior to the polyisocyanate in the raw material liquid preparation step will be described. However, the present invention is not limited to this, the supercritical state, subcritical state or liquid state carbon dioxide may be mixed into the polyisocyanate before the active hydrogen compound, the polyisocyanate and the active hydrogen It may be mixed with both of the compounds. For example, the liquefied carbon dioxide may be mixed with the polyisocyanate by changing the installation positions of the active hydrogen compound storage container 50 and the polyisocyanate storage container 110 in FIG. Further, in FIG. 1, the fluid line L30 is branched to, for example, a fluid line L1.
20 and the liquefied carbon dioxide in the fluid line L30 may be mixed with both the polyisocyanate and the polyol.

Further, in the polyurethane foam manufacturing apparatus 1 described above, from the viewpoint of keeping the temperature of the sprayed liquid constant, a heat retaining means (not shown) such as a heater for keeping the temperature of the gun itself 150 is provided. You may. Furthermore,
From the viewpoint of maintaining the temperature of the fluid flowing through each fluid line constituting the apparatus, a heat retaining means (not shown) such as a heater for retaining the temperature of each fluid may be provided.

Further, in the polyurethane foam manufacturing apparatus 1 described above, the gun 150 having a spray nozzle is provided.
Although the description has been given of the case where the raw material liquid is discharged to the outside by using the above, the means for discharging the raw material liquid to the outside is not particularly limited to this. For example, a mixing head may be used.

[0080]

Hereinafter, the method of embankment embankment and the method of manufacturing a polyurethane foam for civil engineering according to the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Not something.

(Examples 1 to 14) Polyol A (sucrose amine-based polyether polyol, hydroxyl value; 300 KOH mg / g, viscosity (25 ° C.); 1500 mPa · s), polyol B at the compounding ratio shown in Table 1 (Ethylenediamine-based polyether polyol, hydroxyl value;
760 KOH mg / g, viscosity (25 ° C.); 50,000 m
Pa · s), a foam stabilizer (silicone-based foam stabilizer), a catalyst (pentamethyldiethylenetriamine), a viscosity modifier (trischloropropyl phosphate), and a polyol containing water were prepared. On the other hand, polyisocyanates (polymethylene polyphenyl polyisocyanate, N
CO group content; 31% by mass, viscosity (25 ° C.); 350 m
Pa · s) was prepared.

Thereafter, H-2 manufactured by Gasmer Admiral Co., Ltd.
000 foaming machine and model GX- made by Gasmer Admiral
Using a 7 gun, a polyol and a polyisocyanate are mixed, carbon dioxide as a foaming agent is further mixed into a raw material liquid, and this is used as a raw material liquid. A wooden box having an opening (the inner space is 1800 × 1800 × 1000 mm) (A rectangular parallelepiped of size) to form a polyurethane foam inside the wooden box. Tables 2 and 3 show the injection conditions of the raw material liquid at this time.

The content of carbon dioxide shown in Table 2 is as follows:
It is a value represented by 100 × (mass of introduced carbon dioxide) / (total mass of raw material liquid containing carbon dioxide). Further, the polyurethane foam layer formed inside the wooden box is formed so as to have a height of 50 mm by a single discharge, and thereafter repeatedly laminated at intervals of 10 minutes to finally have a height of 1000 mm. Formed as follows. Further, Examples 1 to
In the preparation of the raw material liquid of Example 14, in Examples 1 to 12 and Example 14, carbon dioxide was mixed in the polyol in advance, and in Example 13, carbon dioxide was mixed in the polyisocyanate in advance.

The values of "NCO / OH" in Tables 2 to 5 indicate the above-mentioned isocyanate index.

(Examples 15 to 18) Except that the compounding ratio of carbon dioxide and water was set to the value shown in Table 4, the same procedure as in Examples 1 to 14 was performed at the compounding ratio shown in Table 1. Urethane foam was manufactured.

(Comparative Example 1 and Comparative Example 2) Except that carbon dioxide was not used, Example 1 was used in the compounding ratio shown in Table 1.
-A urethane foam was produced in the same procedure as in Example 14.

[Evaluation Test] Regarding the polyurethane foam layers of the examples and comparative examples obtained as described above,
The degree of cracking of the polyurethane foam, the state of the cells formed inside the polyurethane foam, the internal temperature of the polyurethane foam, the density of the polyurethane foam,
The compressive strength of the polyurethane foam was evaluated by the following method, and the results are shown in Tables 2 to 5.

(1) Evaluation of the degree of occurrence of cracks in polyurethane foam 24 hours after the formation of the polyurethane foam layer, the polyurethane foam layer was divided into two equal parts and visually observed. I checked whether or not.

(2) State of cells formed inside polyurethane foam, good mixing of polyol and polyisocyanate, fine and uniform distribution of cells, no unevenness The sample having no mixing was designated as 2, and the sample having poor and coarse and uneven mixing was designated as 1.

(3) Internal Temperature of Polyurethane Foam The maximum temperature at the center of the formed polyurethane foam layer was measured with a thermocouple to determine the internal temperature of the polyurethane foam. This temperature is preferably 100 ° C. to 170 ° C. from the viewpoint of preventing thermal deterioration of the polyurethane foam itself. If it exceeds 170 ° C. to 200 ° C., thermal deterioration of the polyurethane foam itself proceeds.

(4) Density of Polyurethane Foam 100
A test piece of × 100 × 30 mm was collected and subjected to JIS A95
The density of the polyurethane foam was measured according to the 11-specified density measurement method.

(5) Compressive Strength of Polyurethane Foam 100
A test piece of × 100 × 30 mm was collected and subjected to JIS K72.
The compressive strength at 1% strain of the polyurethane foam was measured according to a method for measuring the compressive strength of 20 standards.

[0093]

[Table 1]

[0094]

[Table 2]

[0095]

[Table 3]

[0096]

[Table 4]

[0097]

[Table 5]

(Example 19) On the steep ground 300 similar to the ground shown in FIG. 2, based on the embankment embedding method of the present invention and the method of manufacturing a polyurethane foam for civil engineering, the same as that shown in FIG. The embankment 2 having the configuration described above was experimentally produced. A gap formed between the inclined surface F300 and the retaining wall 220 made of a concrete plate {maximum depth (height): 3000 mm, maximum width: 3000 mm, length;
The conditions for forming the polyurethane foam at 000 mm｝ were the same as those in Example 7 described above.

When the foam layer 200 made of polyurethane foam is formed, the amount of the raw material liquid discharged at one time toward the ground 300 is such that the height of the foam layer 200 is 50 m
m and the lamination height per day was 1500 mm, and the formation of the foam layer 200 was completed over two days. In the foam layer 200 made of a polyurethane foam actually formed, no internal cracking was observed due to a small internal heat generation during the formation. Also, the foam layer 200
The structure was formed as a tough, highly durable structure integrated with the shape of the inclined surface F300 of the ground 300 at the construction site.

[0100]

As described above, according to the embankment construction method of the present invention, a lightweight embankment having excellent strength and durability can be quickly and easily constructed at the embankment construction site, and the embankment during construction can be constructed. The load on the environment can be sufficiently reduced. In addition, according to the method for producing a polyurethane foam for civil engineering of the present invention, a polyurethane foam having excellent strength and durability can be quickly and easily formed in an arbitrary size and shape at a place of use, and the production can be performed. The load on the inside environment can be sufficiently reduced.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an example of a basic configuration of an apparatus for producing a polyurethane foam based on a method for embankment embankment of the present invention and a method for producing a polyurethane foam for civil engineering of the present invention.

FIG. 2 is a schematic sectional view showing a configuration of an example of an embankment formed based on the embankment construction method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Urethane foam manufacturing apparatus, 2 ... Embankment, 10 ... Liquefied carbon dioxide cylinder, 12, 62, 64 ... On-off valve, 20 ...
Heat exchanger, 30: compression metering pump, 31: piston, 5
0 ... active hydrogen compound storage container, 60 ... chiller, 70 ... compression metering pump, 80 ... static mixer, 90 ... heater, 100 ... heating hose, 110 ... polyisocyanate storage container, 120 ... compression metering pump, 130 ... heater 140: heated hose, 150: gun with spray nozzle, 160: raw material liquid for forming polyurethane foam, 200: foam layer made of polyurethane foam,
220: retaining wall, 230: paved road, 250: anchor,
300: ground, F300: slope of ground, L10: fluid line, L20: heat transfer tube, L21, L30, L50, L
60, L61, L63, L70, L80, L90, L1
10, L120, L130 ... fluid line.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B29L 31:00 B29L 31:00 (72) Inventor Takayoshi Jono 562-10 Shinanomachi, Totsuka-ku, Yokohama-shi, Kanagawa-ken ( 72) Inventor Ryuichi Komori 1021-33, Ohashi-cho, Sano-shi, Tochigi (72) Inventor Shigeo Shimada 167-1, Ishizuka-cho, Sano-shi, Tochigi F-term (reference) 2D044 CA08 4F204 AA42 AB02 AB16 AD03 AD18 AG20 AH43 EA01 EA05 EB01 EB11 EB11 EF02 4J034 BA08 CA01 CA03 CA04 CA05 CA12 CA15 CB02 CB03 CB04 DA01 DB03 DF01 DG01 DG03 DG04 DH00 HA01 HA02 HA07 HB06 HB07 HB08 HB09 HC03 HC12 HC16 HC17 HC22 JA37 KA01 NA01 NA03 QB19 QC01 RA10

Claims (6)

[Claims] An embankment construction method for forming an embankment including a foam layer made of polyurethane foam at an embankment construction site by using a raw material liquid containing a polyisocyanate, an active hydrogen compound, and a foaming agent, A method for constructing an embankment, comprising using carbon dioxide in a supercritical state, a subcritical state or a liquid state as an agent. 2. The embankment construction method according to claim 1, wherein carbon dioxide and water in a supercritical state, a subcritical state, or a liquid state are used as the blowing agent. 3. The method according to claim 1, wherein an isocyanate index of the raw material liquid is 0.95 to 2.0. 4. A raw material liquid preparation step of preparing a raw material liquid containing a polyisocyanate, an active hydrogen compound, and a blowing agent; and reacting the polyisocyanate with the active hydrogen compound using the raw material liquid. A foam forming step of forming a polyurethane foam by advancing the foaming and curing of the obtained polyurethane, and using carbon dioxide in a supercritical state, a subcritical state, or a liquid state as the blowing agent. Of producing polyurethane foam for civil engineering. 5. The method for producing a polyurethane foam for civil engineering according to claim 4, wherein carbon dioxide and water in a supercritical state, a subcritical state, or a liquid state are used as the blowing agent. 6. The method for producing a polyurethane foam for civil engineering according to claim 4, wherein an isocyanate index in the raw material liquid is 0.95 to 2.0.