KR20070096470A - Resin composition for natm - Google Patents

Abstract

A resin composition for NATM(New Austria Tunnel Method) is provided to improve drawing force, adhesive strength and fixing strength and to increase the curing velocity even in water and sea water. A resin composition comprises 100 parts by weight of a water dispersion comprising water dispersible polyurethane-epoxy-acrylic resin and polybutylene; 5-40 parts by weight of asphalt; and 10-200 parts by weight of a filler selected from an inorganic powder. The water dispersible polyurethane-epoxy-acrylic resin and polybutylene is prepared by mixing a polyol and the dimethylol propionic acid dissolved in a solvent with stirring; mixing it with an isocyanate compound in the presence of a reaction catalyst to prepare a prepolymer; adding triethylamine as a neutralizer to neutralize the COOH group of dimethylol propionic acid, thereby obtaining a polyurethane prepolymer; injecting the neutralized polyurethane prepolymer into water under stirring with high speed with injecting epoxy and acrylic monomer.

Description

Resin Composition for NATM

The present invention relates to a resin composition for NATM, and more particularly, by synthesizing a polyurethane in an aqueous dispersion type, adding and polymerizing epoxy and acrylic monomers and polybutylene, and mixing and forming a filler including asphalt. In addition, the present invention relates to an underwater quickening type resin composition for NATM having a fast curing speed with excellent physical properties in water.

In general, cement mortar or resin mortar is widely used as a fixing agent for crack filling of building structures, connecting structures, and fixing reinforcing bars or anchor bolts to concrete, rock, especially tunnel ceiling rocks. For example, in a construction site, it is often necessary to fix reinforcing bars (2) or anchor bolts on the concrete floor. At this time, a hole is drilled in the concrete floor, and then cemented mortar or resin mortar is fixed in the drilled hole. Secure the rebar or anchor bolt by injecting.

The cement mortar or resin mortar used as a fixing agent is required to have high adhesion and strength, and preferably a fast curing speed.

However, the cement mortar is inconvenient to make the mortar in the field, and above all, a considerable time is required due to curing curing, there is a problem that the pull-out force, adhesive strength and strength fall and cracks occur. Accordingly, in recent years, resin mortar compositions that excel in drawing force, adhesion strength, and strength after curing and are cured by properties have been frequently used.

In particular, the resin composition for NATM is a resin fixing agent widely used in the tunnel support-based method (NATM; New Austria Tunnel Method), which is a raw material of urethane, and is widely used for the front surface adhesion of rock pores and rock-bolt. . Currently produced and disseminated urethane type resin composition (NATM-Resin Composition) is controlled by foaming and drawing by chemical reaction of methylene diisocyanate (MDI; Methylene diisocyanate) and polyol (by quenching, tip) And filling), and has a significant pulling force (10 TON / EA per 500g) and adhesion (6 times that of cement mortar). In addition, the urethane-type NATM-Resin has the advantage of repairing the myriad cracks of concrete.

Urethane type resin composition for cracks (NATM-Resin Composition) has a number of advantages over cement mortar. However, the urethane type resin composition for urethane type gaps (NATM-Resin Composition) has a very weak problem in water, especially seawater.

In general, in a tunnel, underground, seaside, etc., a lot of moisture is present by surrounding moisture, by water sprayed for the purpose of dust removal during drilling, and by seawater itself. Under the above water condition, there is a problem that the physical properties are significantly lowered. That is, under water conditions, there is a problem in that the cure rate is very low along with the drawback, adhesion, weather resistance and strength of the magnetic capacity is not exhibited.

The present invention was invented to solve the conventional problems as described above, by introducing acrylic and epoxy to the polyurethane and at the same time synthesized in a water dispersion, and mixed with the polybutylene, the composition together with excellent physical properties in water It is an object to provide an underwater quickening type resin composition for NATM having a fast curing rate.

In order to achieve the above object, the present invention provides a resin composition for NATM,

After mixing and stirring a polyol and dimethylol propionic acid (DMPA) dissolved in a solvent, the isocyanate compound was mixed in the presence of a reaction catalyst to synthesize a prepolymer, and then triethylamine (TEA) was added as a neutralizing agent. Neutralizing the COOH group of dimethylol propionic acid (DMPA) to obtain a polyurethane (PU) prepolymer, the neutralized polyurethane (PU) prepolymer was added to the stirring water at high speed to perform a water dispersion process A water dispersion composed of a water-dispersed polyurethane-epoxy-acrylic resin and polybutylene synthesized by adding and stirring an epoxy and an acrylic monomer in this water dispersion process;

Asphalt containing 5 to 40 parts by weight based on 100 parts by weight of the aqueous dispersion;

It provides a resin composition for NATM consisting of; 10 to 200 parts by weight based on 100 parts by weight of the water dispersion and a filler selected from inorganic powders.

The resin composition for NATM according to the present invention is instantaneously reacted and cured even in water (including seawater) by mixing with a curing agent, and is hardened by exothermic reaction, and exhibits excellent drawing force, adhesive strength and adhesion strength. .

Hereinafter, the present invention will be described in more detail.

The resin composition according to the present invention comprises an aqueous dispersion composed of a water-dispersed polyurethane-epoxy-acrylic resin and polybutylene; Asphalt; Filler selected from an inorganic substance; is made, including, has a good physical properties and fastening properties by mixing the curing agent.

At this time, the water dispersion, asphalt and fillers are mixed and then packaged in one container, the curing agent is packed in a separate container and supplied to the construction site, useful for the tunnel support-based method (NATM; New Austria Tunnel Method) Used.

The water-dispersed polyurethane-epoxy-acrylic is an emulsion in which an epoxy and an acrylic monomer are introduced into the polyurethane. Specifically, the emulsion is a polyurethane-epoxy-acrylic resin emulsified in water, which is synthesized according to the present invention in the following manner.

First, a polyol is put in a reactor, and then heated to 80 ° C. to completely dissolve the polyol. Dimethylol propionic acid (DMPA) was dissolved in solvent N-methyl-2-pyrrolidone (NMP; N-methyl-2-pyrrolidone), put it in a reactor, and stirred at the same temperature for 30 minutes. Mix well. Next, a final NCO group intended to be obtained by adding dibutyltin dilaurate (DBTL; dibutyltin dilaurate) and an isocyanate compound as a tin catalyst (Sn) -based catalyst in a reactor and reacting at 80 ° C. for 150 minutes. Synthesis of a polyurethane (PU) prepolymer having a terminal group. As such, after the synthesis of the PU prepolymer having an NCO end group is completed, the temperature is lowered to 60 ° C. and triethylamine (TEA) is added as a neutralizing agent to form a carboxyl group (COOH group) group of the dimethylol propionic acid (DMPA). Neutralize After 20 minutes of neutralization, one or more monomers selected from epoxy and acryl are added as diluents and completely diluted for 10 minutes. At this time, the diluent lowers the viscosity of the PU prepolymer to improve the reaction temperature control and flow properties during synthesis, and enables the formation of an emulsion having excellent colloidal stability and water particle size of several tens of nanometers when dispersed.

Apart from the above, while adding water to another reactor and stirring at high speed, the neutralization diluted PU prepolymer is slowly added to carry out the water dispersion process. At this time, at the end of the water dispersion process, at the same time avoid the reaction of the NCO group and water that did not react, and performs the chain extension reaction to have excellent adhesion and fixing strength. The chain extension reaction was diluted with water at 25 ° C. in a chain extender, and stirred for about 2 hours until the chain extension reaction was completed.

In the above reaction process, the polyol is preferably used after completely removing moisture of a low molecular weight polytetramethylene ether glycol (PTMG; poly-tetramethylene ether glycol) by using a vacuum oven. Preference is given to using isophorone diisocyanate (IPDI; Isophorone diisocyanate) as the isocyanate. In addition, the chain extender is an epoxy and an acrylic monomer is used, specifically, may be used two or more selected from epoxy acrylate, methyl methacrylate, ethyl methacrylate, acrylic acid, acryl amide, acryl nitriyl and the like.

When the above reaction is completed, a water-dispersible emulsion-type polyurethane-epoxy-acrylic resin in which epoxy and an acrylic monomer are introduced into the polyurethane is synthesized. Such polyurethane-epoxy-acrylic resins have a network structure, and have excellent pulling force and fixing strength when fixed.

After preparing the water-dispersed polyurethane-epoxy-acrylic resin as described above, polybutylene is added thereto to prepare a water-soluble hybrid dispersion in which polybutylene and polyurethane-epoxy-acrylic resin are mixed.

In addition, asphalt and a filler are mixed in the hybrid water dispersion as described above.

Asphalt is in the form of a solid or semi-solid pitch, which is used to give excellent water resistance. Asphalt is contained in an amount of 10 to 40 parts by weight in 100 parts by weight of the water dispersion, and if it is contained in an amount less than this range, it is inferior in water resistance, and in the case of containing too much, in terms of coating property, adhesiveness and surface strength. Not desirable

The filler is selected from fine powder inorganic materials, for example silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), iron oxide (FeO, Fe ₂ O ₃ ), calcium oxide (CaO), magnesium carbonate (MgCO ₃ ), Calcium carbonate (CaCO ₃ ), fumed silica (fume silica), magnesium oxide (MgO), fly ash (flyed ash) and ceramics (eg, rock, jade, etc.) selected from one or more selected from the crowd Can be used. Such a filler is preferably contained in 10 to 200 parts by weight based on 100 parts by weight of the water dispersion.

The curing agent may be a peroxide compound, specifically, dibenzoyl peroxide or methylethyl peroxide.

In the present invention, the water dispersion is a mixture of polybutylene and water-dispersed polyurethane-epoxy-acrylic resin, which is spread to the construction site and mixed with a curing agent and has excellent pull-out, adhesion and adhesion strength while rapidly hardening in water. And the filler further reinforces the strength.

Specifically, the polybutylene is cured by a radical polymerization reaction with the water-dispersed polyurethane-epoxy-acrylic resin by mixing a curing agent, but hardens by exothermic reaction. And it exhibits the adhesive force several times more than the conventional cement mortar, and several times more than the conventional urethane type resin composition. In addition, according to the present invention, dimethylol propionic acid (DMPA) used in the synthesis of the water-dispersed polyurethane-epoxy-acrylic resin is developed in the network structure of the PU prepolymer to improve adhesion and at the same time compatible with water It has properties to prevent gelation of the aqueous dispersion even at high temperatures.

The water dispersion is 30 to 80 parts by weight of the water-dispersed polyurethane-epoxy-acrylic resin is mixed with respect to 100 parts by weight of polybutylene, the water-dispersed polyurethane-epoxy-acrylic resin is based on 100 parts by weight of water It is preferable that the emulsified polyurethane-epoxy-acrylic resin is 20 to 150 parts by weight.

In addition, the water dispersion and the curing agent may be used by mixing in a weight ratio of 100: 0.5 to 20.

The resin composition according to the present invention is a tunnel construction for NATM (road, railway, subway, underground line), rock reinforcement and retaining wall reinforcement work, joint reinforcement work of the tunnel, steel tower foundation work, mountain bridge construction, dam construction For crack filling of structures in construction of arches and sidewalls of underground power plants, for connecting structures, and for fixing reinforcing bars or anchor bolts in concrete, rock, especially in the top of rocks, and coating on the surface of concrete ground It is also usefully used as. In particular, it is useful in construction sites where moisture exists, such as tunnels or underground.

Hereinafter, specific test examples of the present invention will be described. The following examples are provided only to explain the present invention in more detail, whereby the technical scope of the present invention is not limited.

Example 1

All reactions were carried out after purging nitrogen (N ₂ ) and excluding other side reactions. The reactor was used.

First, a polyol, that is, PTMG (Mw = 1000, OH number = 112) was added to a four-necked reactor, and the temperature was heated to 80 ° C. to completely dissolve the polyol. At this time, before the PTMG-1000 was introduced into the reactor, the vacuum oven was used for 6 hours at 120 ° C. to completely remove water. Dimethylol propionic acid (DMPA) was used to introduce a water-soluble group, but it was dried at 60 ° C. to completely remove water from DMPA, and then dissolved in NMP (using Aldrich's reagent grade). And the dissolved DMPA was put into the reactor and stirred for 30 minutes at the same temperature and mixed well.

Next, a PU prepolymer having a terminal group of the final NCO group to be obtained by adding a reaction catalyst tin DBDB and IPDI (Isophorone diisocyanate: Bayer Co.) in a reactor for 150 minutes at 80 ° C. Was synthesized. The content of NCO groups in the synthesized PU prepolymer was measured using the di-n-butylamine back-titration (DBBT) method, and the theoretical amount of residual NCO groups was calculated based on the reaction with all OH groups. As described above, after the synthesis of the prepolymer having NCO end groups was completed, the temperature was lowered to 60 ° C. and TEA (produced by Junsei Chemical Co., Ltd.) was added as a neutralizing agent to neutralize the COOH group of DMPA. After 20 minutes of neutralization, acrylic monomer was added as a diluent and completely diluted for 10 minutes.

Water was added to another reactor and while stirring at a high speed, the synthesized PU prepolymer was slowly added to perform a water dispersion process. In this case, double-distilled deionized water (DDI water) was used as the dispersion water. At the end of the water dispersion process, the chain extension reaction was performed by adding epoxy acrylate and acrylic acid as chain extenders to avoid the reaction between the NCO group and water which did not react and to increase the molecular weight. In this case, the chain extension reaction was diluted with water at 25 ° C. in a chain extender, and further stirred for about 2 hours until the chain extension reaction was completed to obtain a water-dispersed polyurethane-epoxy-acrylic emulsion. Next, polybutylene was added and stirred. Asphalt, silicon oxide (SiO ₂ ), magnesium oxide (MgO) and silica were further mixed and mixed well, followed by dibenzoyl peroxide.

Then, the mixture was directly injected into a concrete base material having a hole of 20 mm in diameter and 50 mm in depth, and then a long rebar having a diameter of 10 mm and a length of 100 cm was erected. At this time, the hole of the base material was pre-injected with water, and the mixture was injected in a state where water was completely filled. After about 3 hours, the specimen was completely stuck.

With respect to the specimen, the pullout force, reinforcing bar adhesion force and fixing strength were measured in the same manner as in the following [Table 1], and the results are shown in [Table 1]. At this time, the pulling force was measured using a hydraulic drawing machine, the reinforcement adhesive strength and the bonding strength were measured using a universal testing machine UTM (Unversal test machine, Instron, USA).

Comparative Example 1

In the same manner as in Example, except that an epoxy monomer was used as the chain extender in the neutralized PU prepolymer. According to this Comparative Example, a polyurethane-epoxy emulsion was obtained, and the physical properties of the specimens of the Comparative Example were evaluated in the same manner as in Examples, and are shown in the following [Table 1].

Comparative Example 2

In the same manner as in Example, except that acrylic monomer was used as the chain extender in the neutralized PU prepolymer. According to this Comparative Example, a polyurethane-acrylic emulsion was obtained, and the physical properties of the specimens of the Comparative Example were evaluated in the same manner as in Examples, and are shown in the following [Table 1].

Comparative Example 3

Currently, a commercially available urethane type resin composition (domestic, manufactured by S Company) was applied to this comparative example, and was injected into the hole of the concrete base material in the same manner as in the above example to measure physical properties. At this time, the base material was injected with a product after spraying water, the results are as shown in Table 1 below.

Evaluation item Comparative Example 1 Comparative Example 2 Comparative Example 3 Example Assessment Methods Drawing force (ton) 13 15 6 21 Hydraulic drawing machine Rebar Adhesion (kg / cm3) 217 281 11 362 UTM Fixation strength (ton) 16 21 2 34 UTM Exam conditions After 5 hours at room temperature After 8 hours at room temperature After 3 days at room temperature After 3 hours at room temperature -

As shown in [Table 1], in using the chain extender, it can be seen that the embodiment using both the epoxy and the acrylic monomer is superior in terms of all physical properties than Comparative Examples 1 and 2 using the epoxy and the acrylic monomer alone. have. In addition, it can be seen that the embodiment of the present invention is superior in drawing force, adhesive strength and adhesion strength than Comparative Example 3 showing the prior art. In addition, in the case of the embodiment of the present invention, it was found that the reinforcing bar is completely fixed in about 3 hours after being injected into the hole, and the conventional product of Comparative Example 3 was found to be fixed only after 3 days.

As described above, the resin composition according to the present invention is rapidly cured by exothermic reaction in water, and has an effect of exerting excellent drawing force, adhesive force, and adhesive strength.

Claims (2)

In the resin composition for NATM, After mixing and stirring a polyol and dimethylol propionic acid (DMPA) dissolved in a solvent, the isocyanate compound was mixed in the presence of a reaction catalyst to synthesize a prepolymer, and then triethylamine (TEA) was added as a neutralizing agent. Neutralizing the COOH group of dimethylol propionic acid (DMPA) to obtain a polyurethane (PU) prepolymer, the neutralized polyurethane (PU) prepolymer was added to the stirring water at high speed to perform a water dispersion process A water dispersion composed of water-dispersed polyurethane-epoxy-acrylic resin and polybutylene synthesized by adding and stirring epoxy and acrylic monomers in this water dispersion process; Asphalt containing 5 to 40 parts by weight based on 100 parts by weight of the aqueous dispersion; The resin composition for natm (NATM) comprising a; 10 to 200 parts by weight based on 100 parts by weight of the water dispersion and a filler selected from inorganic powders. The method of claim 1, The said water dispersion is 30-80 weight part of water-dispersed polyurethane-epoxy-acrylic resins with respect to 100 weight part of polybutylenes, The resin composition for NATM characterized by the above-mentioned.