JPH04185695A - Soil hardening agent - Google Patents

Abstract

PURPOSE:To obtain the title agent of polyurethane-base which is excellent in self-adhesiveness and effective in sticking or concreting rocks, sand and mud and has a low viscosity by mixing specific liquids A and B. CONSTITUTION:The title agent consists of a liquid A comprising a polyol which is composed primarily of a polyether polyol having two or more active OH groups and has an average OH value of 200-600 and a viscosity of 500cP/25 deg.C or less (e.g. a mixture of an adduct of polypropylene glycol with propylene oxide and an adduct of ethylenediamine with propylene oxide) and a liquid B, comprising an isocyanate which has two or more active NCO groups and has a viscosity of 250cP/25 deg.C or less (e.g. polymeric MDI).

Description

[Detailed Description of the Invention] [Technical Field] The present invention provides a method for excavating tunnels and embanking soil layers.
This invention relates to a soil layer hardening agent that is injected into collapsible ground such as sand and gravel or soft, cracked ground to stabilize the soil layer and shorten the work period.

[Prior art]

Currently, water glass (sodium silicate) is generally used as a method for stably solidifying soil layers, but water glass has the following problems.

■Low strength.

■Poor adhesion to rocks.

■Water glass itself has no elasticity (stretchability) and is brittle.

■It takes a long time from injection to hardening (assimilation).

■Changes in temperature and slight differences in curing agent concentration greatly affect curing time.

■Easy to be affected by groundwater.

■It is alkaline and has safety issues.

■It takes time to adjust the pH.

On the other hand, urethane stock solution overcomes the above problems well, but since it contains components that do not react directly with urethane, such as organic solvents and plasticizers, it can leach out of the soil layer over the long term and contaminate water. There is a risk that the burial mound may be destroyed or the burial mound issue may arise.

〔the purpose〕

An object of the present invention is to provide a soil layer hardening agent that has a low viscosity raw material system, has a high degree of freedom in the polyurethane matrix formed in the soil layer, and has high conformability to soil layers, earth and sand, and stones. .

Another object of the present invention is to develop a new type of polyurethane soil that can achieve the purpose of soil reinforcement without using components that may cause pollution, such as plasticizers, solvents, and heavy metal-containing catalysts. The present invention provides a layer hardening agent.

〔composition〕

The first aspect of the present invention is a polyether polyol having two active hydroxyl groups as a main component, and an average hydroxyl value of 200 to 600.
, a polyurethane-based soil layer curing characterized by comprising a liquid A consisting of a polyol with a viscosity of 500 cps/25°C or less, and a liquid B consisting of an isocyanate having at least two active isocyanate groups and a viscosity of 250 cps/25°C or less. Regarding drugs.

The second aspect of the present invention is that the main component is a polyether polyol having two active hydroxyl groups, and the average hydroxyl value is 200-600.
, comprising a liquid A consisting of a polyol with a viscosity of 500 cps/25°C or less, a liquid B consisting of an isocyanate having at least two active isocyanate groups and a viscosity of 250 cps/25°C or less, and a non-metallic catalyst. This invention relates to a polyurethane soil hardening agent.

The reason why the hydroxyl value of Part A is set to 200 to 600 is that the purpose is to consolidate and harden the soil layer, but polyols with a hydroxyl value of less than 200 are soft and do not have a feeling of consolidation, and may cause problems such as shrinkage. I'll wake up.

If a polyol with a hydroxyl value of 600 or more is used, it becomes brittle and also reduces adhesiveness, which is not preferable.

The low clay polyether polyol, which is the main component of liquid A, is difunctional and has a molecular weight of 100 to 10.
00, preferably 200 to 500, such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol or polypropylene glycol (PPG).
) to which ethylene oxide (PE) and/or propylene oxide (PO) are added, and these can be represented by the following formula.

CH, C)! .

HO-CI(CH, O+CH, CH2O+-nHPPG
εOCHL A subpolyol may be blended with the polyether polyol, which is the main component of the liquid A.

The purpose of blending this sub-polyol is to increase the strength, and for example, from among the following polyols, a compound that can improve the strength is selected depending on the type of the polyether polyol as the main component. Examples of subpolyols include ethylene glycol, propylene glycol, polypropylene glycol, trimethylolpropane, diethylene glycol, triethylene glycol, hexamethylene glycol, glycerin, 1,3-
Butylene glycol, 1,4-butanediol, hexanetriol, pentaerythritol, sorbitol,
There are polyether polyols such as polyhydric alcohols such as neopentyl glycol, and compounds obtained by addition polymerization of the polyhydric alcohols and alkylene oxides such as ethylene oxide and propylene oxide.

The amount of subpolyol used is 50iit% or less in liquid A,
It is usually 20 to 3 (ht%), and the average hydroxyl value of liquid A as a whole is adjusted to 200 to 600 and the viscosity to 500 cps/25°C or less.

In the present invention, liquid A preferably has a combination of polypropylene glycol-based bifunctional polyether and the above-mentioned subpolyol as the main polyol.
Functional alcohols such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,6-hexanediol (hexamethylene glycol), 1,3-butanediol (1°3
-butylene glycol), 1,4-butanediol, and polyether polyols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to other difunctional alcohols can also be used in combination.

Isocyanates used for liquid B include bifunctional pure isocyanates and bifunctional or higher functional polymeric isocyanates. Examples of pure isocyanates include diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), and polymeric MDI. 1. Since the present invention is used for soil layers, it is preferable to use a material with low toxicity and high safety.

Polymeric MDI is a polyfunctional mixture of diphenylmethane diisocyanate (MDI), and the model formula is approximately as follows.

Generally, the average functional group (number of NC○ groups in one molecule) is 2.2
~3.0 (n = Q, 3 to 1.0), but the average number of functional groups is preferably close to 2.2, particularly preferably n = 0.6 on average and a molecular weight of about 320.

The catalyst used is one that does not contain any heavy metals.

Specifically, known amine catalysts used in polyurethane reactions and catalysts of other metals other than heavy metal 2 can be used, but amine catalysts are preferred.

Examples of amine catalysts include tertiary amines such as triethylamine, benzyldimethylamine, triethylenediamine, tetramethylbutanediamine, and 2-methyl-triethylenediamine;
O) Undecene-7 (hereinafter abbreviated as rDBUJ)
and DBU salts such as phenol salts, stearates, oleates, and formates.

Examples of metal catalysts include stannous acetate and stannous octanoate.
Tin, stannous carboxylic acids such as stannous laurate, stannous olein, dibutyltin acetate, dibutyltin dilaurate, dibutyltin maleate, dibutyltin di-2-ethyl hexasoate, dilauryltin diacetate, dioctyl Dialkyl tin salts of carboxylic acids such as tin diacetate, trialkyl tin hydroxides such as trimethyl tin hydroxide, tributyl tin hydroxide, trioctyl tin hydroxide, dialkyl tin oxides such as dibutyl tin oxide, dioctyl tin oxide, dilauryl tin oxide, Examples include dialkyltin chlorides such as dibutyltin dichloride and dioctyltin dichloride.

[How to use the curing agent of the present invention]

Holes are drilled at predetermined intervals in soft ground or rock, an injection pipe is inserted into the hole, and the gap between the pipe and the hole is sealed with a packing or caulking agent. In this state, the injection is performed by discharging a liquid urethane foam stock solution, which is a mixture of liquid A and liquid B, from the tip of the injection pipe.

Mixing can be accomplished by sending predetermined amounts of liquids A and B into a mixing chamber using respective pumps, and quickly mixing them using a static mixer or similar mixing device.

〔Example〕

Composition of liquid A, Manufacturer name: Asahi Glass) Triethylenediamine 285 parts by weight water
Composition of 1.5 parts by weight of liquid B [Effect] The present invention aims to reduce the viscosity of the raw material by using a polyether polyol (diol) having 2 functional groups as the main polyol, and also to reduce the viscosity of the raw material by reducing the amount of water and isocyanate. Since carbon dioxide produced by the reaction is used as the only blowing agent, it has a large ability to spread into the soil layer without using solvents or plasticizers, and the polyurethane matrix formed in the soil layer has a high degree of freedom. , has high followability to soil layers, earth and sand, and stones.

Additionally, no metal catalysts containing heavy metals or blowing agents such as Freon are used.

Therefore, according to the present invention, 5 solvents, plasticizers.

There is no need to worry about freon and possibly heavy metals leaching into groundwater and causing pollution. Further, since the composition of the present invention has a low viscosity, the stirring performance during mixing and stirring is good, and the liquid fluidity after mixing and stirring is also good.

Since the soil hardening agent of the present invention forms a polyurethane resin, it has high self-adhesive properties and is effective in adhering and consolidating rocks, sand, and mud. In addition to its low viscosity, the foaming pressure during foaming allows it to spread over a wide range of spaces through rocks, sand, etc. In addition, the urethane resin itself has excellent mechanical strength and elasticity, making it highly flexible, and has excellent ability to hold rocks, sand, and mud after solidification.

By selecting a catalyst, the curing time can be adjusted depending on the application, and by using a formulation with low temperature dependence, curing can be completed in a constant time even when the temperature changes.

Claims (1)

[Claims] 1. The main component is a polyether polyol having two active hydroxyl groups, the average hydroxyl value is 200 to 600, and the viscosity is 500.
cps/A liquid consisting of a polyol of 25°C or less and a viscosity of 250c having at least two active isocyanate groups.
A polyurethane-based soil hardening agent characterized by comprising a B liquid consisting of isocyanate having a temperature of ps/25° C. or less. 2. Main component is polyether polyol having two active hydroxyl groups, average hydroxyl value 200-600, viscosity 500
cps/A liquid consisting of a polyol of 25°C or less and a viscosity of 250c having at least two active isocyanate groups.
A polyurethane soil hardening agent characterized by comprising a B liquid consisting of isocyanate having a temperature of ps/25° C. or less and a nonmetallic catalyst.