JP2001158881A - Urethane composition for filling cavity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a urethane composition which is used for filling cavities, is lightweight, can be prepared at a low cost, and can be applied with a compact application installation in a short time. SOLUTION: This urethane composition for filling cavities comprises a liquid A containing as a main component a polyol component having the below- described characteristics (a) to (c) and a liquid B containing an isocyanate component as a main component, and having an NCO index of 120 to 200. (a) The polyol component contains a multi-functional polyol having the functional group number of 3 or more as a main component. (b) The average functional group number is set to a range of 2 to 3.5. (c) The average hydroxyl group value is set to a range of >=200 and <350.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane composition for filling a cavity or the like existing on the back of lining concrete of an aging existing tunnel to remodel the tunnel.

[0002]

2. Description of the Related Art In general, an aging existing tunnel often has a cavity in the back of lining concrete, and the stress of the ground is concentrated in the cavity, and there is a risk of collapse. Therefore, for the purpose of reforming such a tunnel, a method of filling a cavity with a cavity filler is generally performed. As the cavity filler, conventionally, an inorganic mortar filler, an organic urethane filler, and the like have been used.

[0003]

However, the above-mentioned mortar-based filler is inexpensive, but has a large material specific gravity, a heavy weight load on aged lining concrete, and requires a large amount of construction equipment. There is a drawback that it takes a long time to construct and is inferior in workability. On the other hand, the urethane-based filler has a small foaming density, is light in weight, has a compact construction facility, and can be constructed for a short period of time, but has a drawback of high material cost.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a urethane composition for filling a cavity, which is lightweight, low-cost, compact in construction equipment, and capable of short-term construction.

[0005]

In order to achieve the above object, the urethane composition for filling voids according to the present invention comprises a polyol component having the following characteristics (a) to (c) as a main component. A liquid and a B liquid containing an isocyanate component as a main component, and having an NCO index of 120 to 20.
The configuration is such that it is set in the range of 0. (A) A polyfunctional polyol having three or more functional groups is a main component. (B) The average number of functional groups is set in the range of 2 to 3.5. (C) The average hydroxyl value is set in a range of 200 or more and less than 350.

The present inventors have developed a urethane-based filler having an expansion ratio of about 40 times, and filed a patent application (Japanese Patent Application No. 11-87195), but compared with a mortar-based filler. The cost is insufficient. Therefore, the present inventors have intensively studied to realize a low cost equivalent to a mortar-based filler while utilizing the light weight and simple workability of the urethane-based filler. As a result, a polyfunctional polyol having a number of functional groups of 3 or more is a main component, the average number of functional groups is 2 to 3.5, and the average hydroxyl value is 200 or more and 35 or more.
When a specific polyol component less than 0 is used and N
When the CO index is set in the range of 120 to 200, the expansion ratio becomes about 50 times, and it has been found that the cost can be reduced as low as the mortar filler.

In the present invention, the phrase "contains a polyol component as a main component" is intended to include the case where the solution A comprises only a polyol component. This is intended to include the case of only consisting of In addition, the expression that a polyfunctional polyol having three or more functional groups as a main component includes a case where the polyol component is composed of only a polyfunctional polyol.

[0008]

Next, embodiments of the present invention will be described in detail.

The urethane composition for filling voids according to the present invention comprises a liquid A containing a specific polyol component as a main component and a liquid B containing a isocyanate component as a main component.
The index is set in the range of 120 to 200.

The above-mentioned polyol component is mainly composed of a polyfunctional polyol having three or more functional groups. The polyfunctional polyol is not particularly limited, and examples thereof include alkylene glycols such as polyethylene glycol, polypropylene glycol, trimethylolethane, trimethylolpropane, hexylene glycol, castor oil, glycerin, sorbitol, sucrose, ethylenediamine, diethanolamine, and the like. Polyether polyols obtained by ring-opening polymerization of alkylene oxides such as ethylene oxide and propylene oxide with a compound using these compounds alone or in combination of two or more based on polyfunctional active hydrogen compounds such as triethanolamine. Is raised. These may be used alone or in combination of two or more.

The number average molecular weight (M
n) is preferably in the range of 400 to 1500, particularly preferably 500 to 1000. That is, Mn is 40
If it is less than 0, the internal heat generation temperature at the time of foaming becomes too high or the foaming property becomes high, so that the foam shrinks. This is because the strength of the material after curing tends to decrease.

In addition, the polyol component may be used in combination with a polyol having a functional group of less than 3 (low-functional polyol) together with the polyfunctional polyol. As described above, when the polyfunctional polyol and the low-functional polyol are used in combination, the blending ratio of the polyfunctional polyol is preferably set to 25% by weight or more of the entire polyol component, and particularly preferably 50% by weight or more. That is,
If the proportion of the polyfunctional polyol is less than 25% by weight, problems such as collapse of cells at the time of foaming and increase in internal heat generation temperature are likely to occur.

The low-functional polyol is not particularly limited, and may be, for example, polyethylene glycol (ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, etc.), polypropylene glycol (propylene glycol, dipropylene glycol, etc.), polyoxyethylene. Polyoxypropylene alkyl monol, 1,2-butanediol, 1,3
-Butanediol, 1,4-butanediol, propanediol and the like. These may be used alone or in combination of two or more.

The average number of functional groups of the polyol component containing the above-mentioned polyfunctional polyol as a main component must be set in the range of 2 to 3.5, and is preferably 2.5 to 3.3. That is, when the average number of functional groups is less than 2, the resin strength is reduced, so that the compressive strength of the foam is low, and the cells are apt to collapse at the time of foaming. This is because foam shrinkage after molding becomes large.

The average hydroxyl value of the polyol component must be set in the range of 200 or more and less than 350,
Preferably it is 200-300. That is, when the average hydroxyl value is less than 200, the resin strength is reduced, so that the compressive strength of the foam is low, and also the cell collapse at the time of foaming is easy to occur. This is because foam shrinkage after molding becomes large.

It is preferred that the above-mentioned liquid A be used in combination with a nullating catalyst, an amine catalyst, water and the like in addition to the above-mentioned specific polyol component.

The above-mentioned nullation catalyst is a so-called isocyanate trimerization catalyst, and is used for trimerizing isocyanate to form a hard segment. Examples of such a nullation catalyst include potassium octylate, potassium acetate, tris- (dimethylaminopropyl) hexahydro-s-triazine and the like. These may be used alone or in combination of two or more. Above all, potassium octylate is preferably used in terms of the rate of nullation and cost.

The mixing ratio of the above-mentioned nullating catalyst is
It is preferably set in the range of 0.5 to 4% by weight in the total amount of the liquid and the liquid B, particularly preferably 1 to 2% by weight.
That is, when the proportion of the nullating catalyst is less than 0.5% by weight, the proportion of the isocyanate trimer constituting the hard segment is reduced, and the compressive strength may be reduced. This is because brittleness is increased due to an increase in the rate of nullation, and the reaction rate is significantly increased, which may deteriorate the filling property and the workability.

Examples of the amine catalyst include triethylenediamine, bis- (dimethylaminoethyl) ether, tetramethylhexamethylenediamine, tetramethylpropane-1,3-diamine, pentamethyldiethylenetriamine, bis (dimethylaminoethyl) ether , Trimethylaminoethylpiperazine, 1-methylimidazole, 1-isobutyl-2-methylimidazole and the like. These may be used alone or in combination of two or more. When such an amine catalyst is used, the reaction between the polyol and the isocyanate is promoted, the exothermic reaction can be suppressed by suppressing the islation of the isocyanate, and the exothermic temperature of the foam is reduced. Even when it is used to fill a cavity or the like existing in a cavity, it is possible to suppress the accumulation of heat in the cavity and the ignition.

The compounding ratio of the amine catalyst is preferably set in the range of 0.1 to 1% by weight, particularly preferably 0.2 to 0.5% by weight, based on the total amount of the solution A and the solution B. is there. That is, when the proportion of the amine catalyst is less than 0.1% by weight, the reaction between the polyol and the isocyanate is slow, and a desired expansion ratio may not be obtained.
If the content is more than 10% by weight, the reactivity increases, and the gelation of the resin tends to be too fast, and the workability tends to deteriorate.

The above water is used as a foaming agent. The mixing ratio of the water is 1.5 to 5 in the total amount of the solution A and the solution B.
It is preferably set in the range of weight%, particularly preferably 1.8 to 2.5 weight%. That is, if the ratio of the water is less than 1.5% by weight, a desired expansion ratio cannot be obtained, and a foaming pressure may be increased.
This is because, if it exceeds, the foam becomes brittle and the compressive strength may be reduced.

The liquid A may contain a foam stabilizer, a flame retardant or the like. Examples of the foam stabilizer include polyoxyalkylene / dimethylpolysiloxane copolymer, organopolysiloxane, oxyethylated higher alcohol, and the like.
Used in combination of more than one species. Examples of the flame retardant include trischloropropyl phosphate and tris-β-
Chloropropyl phosphate and the like can be mentioned, and these can be used alone or in combination of two or more.

The liquid B used together with the liquid A is a liquid containing an isocyanate component as a main component.

The isocyanate component is not particularly restricted but includes, for example, diphenylmethane-4,4'-diisocyanate (MDI), crude MDI (polymeric MDI), tolylene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone Diisocyanate (IPDI), xylylene diisocyanate (XDI) and the like. These may be used alone or in combination of two or more. Above all, crude MDI having a viscosity of 90 cps / 25 ° C. or less is preferably used in that the reaction cured product has good compression characteristics and low volatility during the reaction.

The liquid B may contain a reactive diluent in addition to the isocyanate component.
As described above, when the isocyanate component and another component are used in combination, the mixing ratio of the isocyanate component is preferably set to 50% by weight or more of the whole liquid B, and particularly preferably 80% by weight or more.

Examples of the reactive diluent include alkylene carbonate and dibasic acid ester.
These may be used alone or in combination of two or more. Specific examples of the alkylene carbonate include ethylene carbonate and propylene carbonate. When the reactive diluent is used in this manner, the foam is stabilized because it is decomposed to generate carbon dioxide gas, and the viscosity can be adjusted to a level suitable for use.

B containing the above isocyanate component as a main component
The viscosity of the liquid is preferably set to 90 cps / 25 ° C. or less, and particularly preferably in the range of 90 to 40 cps / 25 ° C. That is, if the viscosity exceeds 90 cps / 25 ° C., the gelation of the resin is slow and the stability of the cells during foaming is deteriorated, so that the desired foaming ratio cannot be obtained.

The urethane composition for filling a cavity according to the present invention comprises N
It is necessary to set the CO index to be in the range of 120 to 200, preferably 140 to 180.
That is, if the NCO index is less than 120,
This is because foam shrinkage after molding is large and strength is weak. Conversely, if it exceeds 200, a high expansion ratio cannot be expected.
The NCO index refers to a mixing ratio (molar ratio) between an NCO group and an active hydrogen-containing group (OH group).

In the urethane composition for filling a cavity according to the present invention, the mixing ratio of the liquid A and the liquid B is expressed by weight ratio, liquid A: liquid B =
It is preferable to set the ratio in the range of 1: 1 to 1: 3, and it is particularly preferable that the ratio of solution A: solution B = 1: 1.5 to 1: 2.5. That is, if the mixing ratio of the B liquid is less than 1, the compressive strength of the foam decreases, and if it exceeds 3, the foam becomes brittle and the compressive strength decreases.

The urethane composition for filling voids of the present invention preferably has an expansion ratio of at least 45 times, particularly preferably at least 50 times.

In the urethane composition for filling voids of the present invention, the foam preferably has a compressive strength of 0.05 Mpa or more, particularly preferably 0.08 Mpa or more.

Further, the urethane composition for filling voids of the present invention preferably has a core density (apparent density) of 25 kg / m ³ or less, particularly preferably 20 kg / m ³ or less.

Next, a method for filling a cavity using the urethane composition for filling a cavity of the present invention will be specifically described with reference to the drawings. As shown in FIG. 1, when the cavity 2 is formed in the ground 1, the tip side of the pipe 3 is inserted into the cavity 2 from the lining concrete 5 of the tunnel 4. Next, the cavity filling urethane composition of the present invention is filled into the cavity 2 through the pipe 3 by a filler injection device (not shown). Then, the urethane composition for filling a cavity is foamed and cured to form a foam, and the cavity 2 is filled with the foam.
According to this method, since the cavity 2 is filled with the foam, the stress of the ground 1 is relaxed to prevent collapse or the like,
It is possible to prevent the occurrence of cracks or the like by suppressing the pushing force.

The use of the urethane composition for filling a cavity according to the present invention is not limited to the renovation of an aging existing tunnel. For example, the urethane composition may be used for filling a cavity existing in a floating pier. It is.

Next, examples will be described together with comparative examples.

First, prior to Examples and Comparative Examples, the following materials were prepared.

[Polyfunctional polyol a] Trimethylolpropane-based polyol (Actocol G-250, manufactured by Takeda Pharmaceutical Company Limited) [hydroxyl value (OH
V) = 250, Mn = 670, number of functional groups (f) = 3]

[Polyfunctional polyol b] Tolylenediamine-based polyol to which propylene oxide has been added (Actocol DT- manufactured by Takeda Pharmaceutical Co., Ltd.)
250) [OHV = 255, Mn = 880, f = 4]

[Polyfunctional polyol c] Ethylenediamine-based polyol to which ethylene oxide and propylene oxide are added (Actocol GR-11, manufactured by Takeda Pharmaceutical Co., Ltd.) [OHV = 450, M
n = 670, f = 4]

[Polyfunctional polyol d] Trimethylolpropane-based polyol (Actocol 32-160, manufactured by Takeda Pharmaceutical Co., Ltd.) [OHV = 16
0, Mn = 1052, f = 3]

[Low-functional polyol e] Polypropylene glycol (Actocol P-400, manufactured by Takeda Pharmaceutical Co., Ltd.) [OHV = 280, Mn = 400,
f = 2]

[Low Functional Polyol f] Polyoxyethylene polyoxypropylene monobutyl ether (Leosolve 703B manufactured by Lion Corporation) [OHV
= 245, Mn = 229, f = 1]

[Amine catalyst a] Tetramethylhexamethylenediamine (Kaolyzer No. 1 manufactured by Kao Corporation)

[Amine catalyst b] N, N, N ', N ", N" -pentamethyldiethylenetriamine (Kaolyzer No. 3 manufactured by Kao Corporation)

[Nulating catalyst] Potassium octylate (Hexoate potassium K-13, manufactured by Toei Chemical Co., potassium content: 13% by weight)

[Foam stabilizer] Polyoxyalkylene / dimethylpolysiloxane copolymer (SZ-1627, manufactured by Nippon Unicar Co., Ltd.)

[Flame retardant] Tris β-chloropropyl phosphate (TMCPP, manufactured by Daihachi Chemical Industry Co., Ltd.)

[Isocyanate Component] Crude MDI (Lupranate MB-5S, manufactured by BASF Inoac) [Viscosity: 50 cps / 25 ° C.]

[0049]

Examples 1 to 10 and Comparative Examples 1 to 6 The components of Solution A and Solution B shown in Tables 1 to 3 below were blended in the proportions shown in the same table.
Liquid and liquid B were separately prepared.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

The liquids A and B of the examples and comparative examples thus obtained were mixed at a predetermined ratio in a 1000 ml disc cup, and were stirred at a liquid temperature of 20 ° C. and 5000 rpm × using a stirrer (homodisper). The mixture was stirred for 6 seconds to react, and the foaming characteristics were evaluated. Further, the confirmation of the maximum heat generation temperature and the substantial expansion ratio of 50 times was performed by injecting a predetermined amount of urethane into a 9-liter container. These results are also shown in Tables 4 to 6 below.

[Cream Time (CT)] After the mixing was completed, the mixture started to foam, turned into a cloudy creamy liquid, and the time until the liquid started to expand was measured.

[Rise Time (RT)] The time required for the creamy liquid to expand and grow into a foamy substance and to complete the expansion was measured.

[Highest exothermic temperature] A temperature sensor was placed in a 9-liter container, and the maximum exothermic temperature was measured using a recorder.

[Substantially 50-fold foaming] A case where the container of 9 liters was completely filled with the foam was evaluated as ○, and a case where the container was not completely filled was evaluated as ×.

[Hinage] After leaving the foam for one day, the presence or absence of sink marks was observed. Note that shrinkage refers to a state in which the CO ₂ gas in the foam gradually escapes after foaming, and the foam shrinks by losing the atmospheric pressure. Then, the case where no sink mark was confirmed was evaluated as ○, and the case where sink was confirmed was evaluated as ×.

[Core Density] The core density (apparent density) of the foam was measured according to the description of ASTM D1622.

[Maximum compressive strength] 50 × 50 m foam
The sample was cut to a size of m (thickness: 50 mm), and the maximum strength was measured when the sample was compressed by 20% in the thickness direction at a compression speed of 5 mm / min.

[0061]

[Table 4]

[0062]

[Table 5]

[0063]

[Table 6]

From the results in Tables 4 to 6, the product of the example was
In each case, the core density is low and the weight is low, and the foaming ratio is high (expansion ratio of 50 or more), so that the material cost is low. Also, since no sink occurs, the compression strength is also excellent. Further, since the maximum heat generation temperature is about 180 ° C., scorch (burn) can be prevented.

On the other hand, the product of Comparative Example 1 does not have a desired expansion ratio because the NCO index is too large, and the material cost is high. In Comparative Example 2, the NCO index is too small, so that sink occurs and the strength is low. In Comparative Example 3, since the average hydroxyl value of the polyol component was too large, sink marks occurred and the strength was low. In Comparative Example 4, the average number of functional groups in the polyol component was too large.
Sinking occurred. The cell of Comparative Example 5 collapsed during foaming because the average hydroxyl value of the polyol component was too small.
Comparative Example 6 had sink marks because the average number of functional groups in the polyol component was too small.

[0066]

As described above, the urethane composition for filling voids according to the present invention has a polyfunctional polyol having a functional group number of 3 or more as a main component, has an average functional group number of 2 to 3.5, and has an average hydroxyl group. A specific polyol component having a value of 200 to less than 350 is used, and the NCO index is 120 to 2
00 is set in the range. Therefore, the expansion ratio becomes about 50 times while utilizing the light weight and simple workability of the urethane-based filler, and the cost can be reduced as low as the mortar-based filler.

The urethane composition for filling voids of the present invention has a lower maximum exothermic temperature than conventional ones, so that even when injected in large quantities, it is possible to suppress scorch fire due to heat storage.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a cavity filling method using a urethane composition for filling a cavity of the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinya Uda 3-1-1 Higashi Higashi, Komaki City, Aichi Prefecture F-term (reference) 4H026 CA06 CB08 CC03

Claims (3)

[Claims] 1. A liquid comprising a polyol component having the following characteristics (a) to (c) as a main component and a liquid B having an isocyanate component as a main component, and having an NCO index of 120 to A urethane composition for filling voids, which is set in the range of 200. (A) A polyfunctional polyol having three or more functional groups is a main component. (B) The average number of functional groups is set in the range of 2 to 3.5. (C) The average hydroxyl value is set in a range of 200 or more and less than 350. 2. The urethane composition for filling voids according to claim 1, wherein the liquid A contains a nullation catalyst, an amine catalyst and water in addition to the polyol component. 3. The urethane composition for filling voids according to claim 1, wherein the viscosity of the liquid B is set to 90 cps / 25 ° C. or less.