Chemical solution composition for ground injection

Abstract

To provide a chemical composition for ground injection capable of showing stable foaming property even under high temperature.SOLUTION: In a chemical composition for ground injection comprising liquid A containing silicate aqueous solution and a catalyst as essential components, and liquid B containing polyisocyanate as an essential component, aromatic polyisocyanate is used as polyisocyanate which is the essential component in the liquid B, and in the liquid A, tertiary amine is contained as the catalyst, and further a primary and / or secondary amino group-containing compound is contained.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a chemical solution composition for ground injection, and particularly to a two-component chemical solution composition for ground injection comprising a liquid A containing a silicate aqueous solution and a catalyst as essential components and a liquid B containing a polyisocyanate as an essential component, and relates to a technique for improving its high-temperature foaming characteristics.

Background Art

[0002] Conventionally, as one of the measures adopted in ground improvement applications for stabilizing unstable rock masses or strengthening the ground and in cavity filling applications for filling cracks and voids in artificial structures, an inorganic or organic grout is injected to consolidate the ground and the like. For example, a method has been adopted in which a foaming polyurethane material formed by combining a polyol and a polyisocyanate is used and injected to foam and cure.

[0003] By the way, in the consolidation method by injecting such a foaming polyurethane material, since a foamed cured body mainly composed of an organic substance (resin) is generated by the urethanization reaction between the polyol and the polyisocyanate, problems such as the occurrence of a fire caused by fire are inherent, and also, since the material itself is expensive, problems such as soaring construction costs are also inherent.

[0004] Therefore, in Japanese Patent Laid-Open No. 5-78667, Japanese Patent Laid-Open No. 2004-075754, etc., an injection chemical solution composed of a liquid A mainly composed of an alkaline silicate aqueous solution, which is cheaper in material cost than conventional polyol-based organic substances, and a liquid B mainly composed of a polyisocyanate is proposed. By injecting these two liquids to foam and cure, a composite foamed cured body of an inorganic substance and an organic substance is formed, and it has been clarified that a higher flame retardancy than that of conventional foaming polyurethane materials can be exhibited.

[0005] However, in the case of the injection chemical solution composed of the liquid A and the liquid B, during construction in summer, the chemical solution may reach a high temperature of 30 to 40 °C due to the outside air temperature, which may have a great impact on the consolidation work of the ground. That is, when the alkali silicate aqueous solution (water glass) and the polyisocyanate react at high temperature, the reaction between water and the polyisocyanate is promoted, so that the reaction between the liquid A and the liquid B starts to foam before the strength of the reaction product (foam) formed by foaming and curing is fully manifested. And before the curing of the reaction product is induced, cell defoaming and breakage will be induced. Therefore, at the end of the foaming stage, the obtained foam-cured body has insufficient strength, so it will collapse due to its own weight, or the strength reduction of the foam-cured body will be caused by coarsening and non-uniformity of the foam cells, etc. Problems will come to be caused.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] Here, the present invention is made against the background of the above-described circumstances. The problem to be solved is to provide a chemical solution composition for ground injection that can exhibit stable foaming characteristics even at high temperatures. Another problem is to provide a two-component chemical solution composition for ground injection composed of a liquid A containing an aqueous silicate solution and a catalyst as essential components and a liquid B containing a polyisocyanate as an essential component, while advantageously ensuring the strength of the foam formed by the reaction, enhancing the stability of the foaming, and further providing a technique capable of obtaining a foam having excellent compressive strength.

Means for Solving the Problems

[0008] And the present invention can be preferably implemented in various aspects listed below in order to solve the above-described problems. Further, each of the aspects described below can be adopted in any combination. It should be considered that the aspects or technical features of the present invention are not limited to those described below, and are understood based on the inventive concept grasped from the description of the entire specification.

[0009] First, in order to solve the above-described problems, the present invention provides a chemical solution composition for ground injection comprising a liquid A containing an aqueous silicate solution and a catalyst as essential components, and a liquid B containing a polyisocyanate as an essential component. As the polyisocyanate, which is an essential component in the liquid B, an aromatic polyisocyanate is used. The liquid A contains a tertiary amine as the catalyst, and further contains a primary and / or secondary amino group-containing compound. This is the first aspect of the chemical solution composition for ground injection.

[0010] Further, in the second aspect of the present invention, a polyamine compound having two or more primary and / or secondary amino groups in one molecule is used as the primary and / or secondary amino group-containing compound.

[0011] Furthermore, according to the third aspect of the present invention, the primary and / or secondary amino group-containing compound has primary and / or secondary amino groups at a ratio of 0.5 to 50 mmol / g.

[0012] In addition, the fourth aspect of the present invention is characterized in that the primary and / or secondary amino group-containing compound is an aromatic amine compound.

[0013] And in a fifth aspect according to the present invention, the primary and / or secondary amino group-containing compound is contained in a proportion of 0.01 to 20 parts by mass with respect to 100 parts by mass of the polyisocyanate.

[0014] Further, a sixth aspect of the present invention is characterized in that the tertiary amine as the catalyst has an alcoholic hydroxyl group.

[0015] Furthermore, a seventh aspect of the present invention is characterized in that the liquid A further contains a polyol.

[0016] In addition, an eighth aspect according to the present invention is characterized in that the liquid A and the liquid B each have a viscosity of 400 mPa·s or less at a temperature of 25°C.

Advantages of the Invention

[0017] Thus, in the chemical solution composition for ground injection according to the present invention, an aromatic polyisocyanate is used as the polyisocyanate which is an essential component in the liquid B, and a tertiary amine is contained as the catalyst which is an essential component in the liquid A. Further, the liquid A contains a primary and / or secondary amino group-containing compound. Therefore, the reaction between the liquid A and the liquid B can proceed effectively, and even during construction under high temperatures (30 to 40°C) in summer, foaming can proceed stably at the initial stage of the reaction. Thus, crosslinking of the reaction product (foam) can be promoted advantageously, and the stability of the properties such as the strength of the reaction product can be enhanced. At the same time, the foam cells can be made uniform, and the shrinkage of the reaction product can be effectively prevented.

[0018] In particular, according to the composition of the ground injection chemical solution according to the present invention, during the reaction between the liquid A and the liquid B, it is possible to foam while advantageously ensuring the strength of the resulting reaction product. Thus, including the strength during foaming, the stability of the properties such as the strength of the reaction product is effectively enhanced, the foam cells are made uniform, and in particular, the shrinkage of the foam at high temperatures (30 to 40 °C) can be effectively suppressed. In addition, by promoting crosslinking in the foam, the compressive strength of the reaction product, which is the foam formed by the reaction, can be advantageously increased.

Embodiments for Carrying Out the Invention

[0019] In short, the present invention is a two-component urethane-based chemical solution composition comprising a liquid A and a liquid B. In such a liquid A, in addition to an aqueous silicate solution which is an essential component, a tertiary amine is used as a catalyst. Further, in a form used in combination with such a tertiary amine catalyst, a compound containing a primary and / or secondary amino group is contained as a crosslinking agent, and as an aromatic polyisocyanate is used as an essential component of the liquid B, an aromatic polyisocyanate. By doing so, the reaction between the liquid A and the liquid B is effectively advanced, and the reaction product (foam) can be formed more stably. Thus, the present invention has a great feature in that the intended purpose can be advantageously achieved.

[0020] And in Solution A, which is one of the two solutions constituting the chemical solution composition according to the present invention, the aqueous silicate solution contained as one of its essential components is an aqueous solution of a soluble silicate compound, which is also called so-called water glass. Here, examples of such silicate compounds include sodium silicate, potassium silicate, sodium metasilicate, potassium metasilicate, lithium silicate, ammonium silicate, etc. Among them, in the present invention, sodium silicate (sodium silicate), which is easily available and inexpensive, is preferably used. And when using sodium silicate, the molar ratio of SiO2 / Na2O is desirably in the range of 2.0 to 4.0. When this molar ratio is less than 2.0, the compatibility with additives such as primary and / or secondary amino group-containing compounds and reaction catalysts deteriorates, and gel formation and the like are likely to be caused, making long-term storage difficult. Also, when the molar ratio is greater than 4.0, the dispersion stability of the solution decreases, and further the freezing point becomes high, which may cause problems such as being unusable in winter.

[0021] By the way, various types of water glass, which is an aqueous sodium silicate solution as described above, are commercially available, and in the present invention, such commercial products can be appropriately selected and used. Regarding the aqueous solution of sodium silicate, it is defined by JIS standards (JIS K 1408) and is known as No. 1, No. 2, No. 3, etc. Also, as long as it is formulated in accordance with this JIS standard, those with formulations such as No. 4, No. 5, etc., or 1.5, 2.5, etc. can also be used. Furthermore, the proportion of the solid component in the water glass in the form of such an aqueous solution varies depending on each type of JIS standard, the type of water glass, etc. From the viewpoints of the stability and solidification characteristics of Solution A, generally, it is about 20 to 60% by mass, and preferably, water glass containing a solid component at a ratio of 30 to 50% by mass is advantageously used.

[0022] In addition, such Liquid A contains a catalyst for promoting the reaction with Liquid B as an essential component. In the present invention, a tertiary amine catalyst is particularly advantageously used.

[0023] Here, as the tertiary amine catalyst, in the case where foaming is intended by contact with water, there are a foaming catalyst having an action of promoting the reaction between polyisocyanate and water, a resinification catalyst having an action of promoting the reaction between polyisocyanate and polyol, and further an isocyanuration catalyst having an action of promoting the trimerization of polyisocyanate, etc. All of them will be appropriately selected from known ones.

[0024] Specifically, examples of the foaming catalyst include N,N,N’,N”,N”-pentamethyldiethylenetriamine (molecular weight: 173.3, boiling point: 198 °C), N,N,N’-trimethylaminoethylethanolamine (molecular weight: 146.2, boiling point: 207 °C), bis(dimethylaminoethyl) ether (molecular weight: 160.3, boiling point: 189 °C), N,N,N’-trimethylaminoethylpiperazine (molecular weight: 171.3, boiling point: 96 °C / 12 mmHg), N,N-dimethylaminoethoxyethanol (molecular weight: 133.2, boiling point: 95 °C / 15 mmHg), triethylamine (molecular weight: 101.2, boiling point: 89.3 °C), and the like. Examples of the resinification catalyst include N,N,N’,N’-tetramethylethylenediamine (molecular weight: 116.2, boiling point: 120 °C), N,N,N’,N’-tetramethylpropanediamine (molecular weight: 130.2, boiling point: 145 °C), N,N,N’,N’-tetramethylhexamethylenediamine (molecular weight: 172.3, boiling point: 210 °C), triethylenediamine (molecular weight: 112.2, boiling point: 174 °C), 33% triethylenediamine·67% dipropylene glycol (molecular weight: 112.2, boiling point: 199 °C), N,N-dimethylaminohexanol (molecular weight: 145.3, boiling point: 117 °C / 12 mmHg), N,N-dimethylaminoethanol (molecular weight: 89.1, boiling point: 133 °C), N-methyl-N’-hydroxyethylpiperazine (molecular weight: 144.2, boiling point: 55 °C / 1.5 mmHg), N-methylmorpholine (molecular weight: 101.2, boiling point: 116 °C), 1-methylimidazole (molecular weight: 82.1, boiling point: 198 °C), 1,2-dimethylimidazole (molecular weight: 96.1, boiling point: 205 °C), and the like. Further, examples of the isocyanuration catalyst include 2,4,6-tris(dimethylaminomethyl)phenol (molecular weight: 265.4, boiling point: 135 °C / 1 mmHg), N,N’,N”-tris(dimethylaminopropyl)-hexahydro-s-triazine (molecular weight: 342.6, boiling point: 141 °C), and the like.

[0025] These catalysts can be used alone or in combination of two or more of them without any problem. Further, among these, a foaming catalyst or a resinification catalyst is preferably used. In particular, among these tertiary amines, those having an alcoholic hydroxyl group are advantageously used in better achieving the object of the present invention. Further, when the molecular weight of such a tertiary amine is low, it is easily volatilized, and problems such as generating odor are caused by the heat of reaction during foaming and the temperature in the construction environment. Therefore, a tertiary amine having a molecular weight of 104 or more, preferably 110 or more, is preferably used. Further, in order to suppress the generation of odor due to the heat of reaction during foaming, a tertiary amine having a boiling point of 100 ° C or more at normal pressure is advantageously used.

[0026] Incidentally, the amount of the tertiary amine as a catalyst contained in such a liquid A is generally appropriately determined at a ratio of 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass, with respect to 100 parts by mass of the polyisocyanate. When the content of the tertiary amine as this catalyst is less than 0.05 part by mass, there is a problem that the contribution to the reaction decreases and the strength of the reaction product cannot be sufficiently ensured. On the other hand, when it exceeds 5 parts by mass, the reaction proceeds too much, an abnormal reaction is caused, the chemical liquid solidifies during the injection operation, and problems such as difficulty in sufficient foaming are caused.

[0027] In addition, such Solution A may, if necessary, contain, as a catalyst, in addition to the above-mentioned tertiary amine, known metal catalysts, quaternary ammonium salt catalysts, etc., as appropriate. In this case, as the metal catalyst, known ones can be used without particular limitation. For example, organic acid metal salts and organometallic complexes of sodium, potassium, calcium, tin, lead, bismuth, zinc, iron, nickel, zirconium, cobalt, etc. can be used. Among them, as the organic acid metal salt, salts of acetic acid, octylic acid, neodecanoic acid, naphthenic acid, rosin acid, etc. with the above metals can be mentioned, and as the organometallic complex, complexes of acetylacetone, etc. with the above metals can be mentioned. Specifically, sodium acetate, potassium acetate, potassium octylate, bismuth octylate, lead octylate, iron octylate, tin octylate, calcium octylate, zinc octylate, zirconium octylate, bismuth neodecanoate, zinc neodecanoate, lead neodecanoate, cobalt neodecanoate, dibutyltin dioctate, dibutyltin dilaurate; iron acetylacetonate, zinc acetylacetonate, zirconium acetylacetonate, nickel acetylacetonate, tin acetylacetonate, etc. can be mentioned. These metal salts and metal complexes may be used after being dissolved in diluents such as mineral spirits, organic acids, glycols, esters, etc. for improving their handleability. Further, these metal catalysts may be used alone or in combination of two or more kinds. Among these, preferably, acetates, octylates, neodecanoates, laurates of potassium, tin, lead, bismuth or zinc, and acetylacetone complexes can be mentioned, and more preferably, catalysts using potassium, tin, bismuth as metals are suitably used.

[0028] In addition, examples of the quaternary ammonium salts include aliphatic ammonium compounds such as tetramethylammonium, methyltriethylammonium, ethyltrimethylammonium, propyltrimethylammonium, butyltrimethylammonium, pentyltrimethylammonium, hexyltrimethylammonium, heptyltrimethylammonium, octyltrimethylammonium, nonyltrimethylammonium, decyltrimethylammonium, undecyltrimethylammonium, dodecyltrimethylammonium, tridecyltrimethylammonium, tetradecyltrimethylammonium, heptadecyltrimethylammonium, hexadecyltrimethylammonium, heptadecyltrimethylammonium, octadecyltrimethylammonium; hydroxyammonium compounds such as (2-hydroxypropyl)trimethylammonium, hydroxyethyltrimethylammonium, and trimethylaminoethoxyethanol; and alicyclic ammonium compounds such as 1-methyl-1-azanium-4-azabicyclo[2,2,2]octanium, 1,1-dimethyl-4-methylpiperidinium, 1-methylmorpholinium, and 1-methylpiperidinium. Among these, tetramethylammonium, methyltriethylammonium, ethyltrimethylammonium, butyltrimethylammonium, hexyltrimethylammonium, octyltrimethylammonium, decyltrimethylammonium, dodecyltrimethylammonium, tetradecyltrimethylammonium, hexadecyltrimethylammonium, octadecyltrimethylammonium, (2-hydroxypropyl)trimethylammonium, hydroxyethyltrimethylammonium, 1-methyl-1-azanium-4-azabicyclo[2,2,2]octanium, and 1,1-dimethyl-4-methylpiperidinium are preferably used because of their excellent catalytic activity and industrial availability.

[0029] In addition, examples of the organic acid group or inorganic acid group constituting such a quaternary ammonium salt include organic acid groups such as formate group, acetate group, octylate group, oxalate group, malonate group, succinate group, glutarate group, adipate group, benzoate group, toluylate group, ethylbenzoate group, methyl carbonate group, phenol group, alkylbenzene sulfonate group, toluene sulfonate group, benzene sulfonate group, phosphate ester group, etc., and inorganic acid groups such as halogen group, hydroxyl group, hydrogen carbonate group, carbonate group, etc. Among these, the formate group, acetate group, octylate group, methyl carbonate group, halogen group, hydroxyl group, hydrogen carbonate group, carbonate group are preferred because they are excellent in catalytic activity and industrially available.

[0030] In addition, various catalysts composed of such quaternary ammonium salts are commercially available. For example, U-CAT18X, U-CAT2313 (manufactured by San Apro), Kaolizer No. 410, Kaolizer No. 420 (manufactured by Kao Corporation), etc. can be mentioned.

[0031] In addition, as yet another additional essential component in the liquid A according to the present invention, a primary and / or secondary amino group-containing compound, which is an amine compound having a primary and / or secondary amino group, will be contained as a crosslinking agent. Here, the primary and / or secondary amino group-containing compound is not particularly limited as long as it is a compound that binds and contains a primary and / or secondary amino group. For example, aliphatic amine compounds, aliphatic polyamine compounds, aromatic amine compounds, aromatic polyamine compounds, amino acids, alkanolamines, etc. can be mentioned.

[0032] Specifically, examples of the aliphatic amine compound include linear amino group-containing compounds such as butylamine, octylamine, and dodecylamine, alicyclic amino group-containing compounds such as cyclohexylamine, and cyclic amino group-containing compounds such as piperidine. Examples of the aliphatic polyamine include linear amino group-containing compounds such as butanediamine, hexanediamine, octanediamine, polyetheramine, triethylenetetramine, tetraethylenepentamine, hydrazine, 1,2-diaminopropane, 1,3-diaminopropane, tetramethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, and diethylenetriamine, alicyclic amino group-containing compounds such as cyclohexanediamine, norbornenediamine, 4,4'-diaminocyclohexylmethane, isophoronediamine, and bisaminomethylcyclohexane, cyclic amino group-containing compounds such as piperazine, and aliphatic amino group-containing compounds having an aromatic ring such as xylylenediamine. Further, examples of the aromatic amine compound include amino group-containing compounds such as aniline, toluidine, anisidine, and methylaniline. Examples of the aromatic polyamine compound include amino group-containing compounds such as toluenediamine, methylenedianiline, phenylenediamine, diaminodiphenylmethane, diaminodiphenyl ether, trimethylphenylenediamine, diethyltoluenediamine, dimethylthiotoluenediamine, 4,4'-methylenebis(N-sec-butylaniline), aminobenzylamine, and methylenebis(ethylmethylaniline). Further, examples of the amino acid include compounds containing a carboxyl group and an amino group in the molecule such as lysine, valine, and asparagine. In addition, examples of the alkanolamine compound include compounds having an amino group and a hydroxyl group in the molecule such as ethanolamine, hexanolamine, and diethanolamine.In addition, polyoxyalkylene diamines obtained by converting the hydroxyl groups of polyoxyalkylene glycols obtained by addition polymerization of propylene oxide and / or ethylene oxide to water, ethylene glycol, propylene glycol, etc. into amino groups, and polyoxyalkylene triamines obtained by converting the hydroxyl groups of polyoxyalkylene triols obtained by addition polymerization of propylene oxide and / or ethylene oxide to glycerin, trimethylolpropane, etc. into amino groups can be mentioned. And these amine compounds having primary and / or secondary amino groups can be used alone or in combination of two or more kinds.

[0033] Further, in the present invention, in order for the primary and / or secondary amino group-containing compound as described above to effectively exhibit its function as a crosslinking agent, it is desirable that it is a polyamine compound having two or more primary and / or secondary amino groups in one molecule. In particular, in order to improve characteristics such as its reactivity and flame retardancy, it is preferably an amine compound having an aromatic ring (aromatic amine compound), more preferably an aromatic polyamine compound. Among them, an aromatic polyamine compound having a structure in which at least one of the positions adjacent to the amino group bonded to the aromatic ring is substituted with an alkyl group is particularly preferably used. Also, among such primary and / or secondary amino group-containing compounds, a compound containing a primary amino group is more preferably used.

[0034] In addition, in the present invention, among the primary and / or secondary amino group-containing compounds as described above, compounds having a primary and / or secondary amino group content of 0.5 to 50 mmol / g, preferably 1 to 20 mmol / g, more preferably 3 to 15 mmol / g are advantageously used. This is because if the primary and / or secondary amino group content is less than 0.5 mmol / g, it may be difficult to sufficiently achieve the object of the present invention, and if it exceeds 50 mmol / g, the crosslinking reaction may proceed too much, causing abnormal reactions, such as the chemical solution solidifying during the injection operation and an effective foam not being obtained.

[0035] Furthermore, a compound containing a primary and / or secondary amino group such as this is generally desirably contained in Liquid A so as to be in a proportion of 0.01 to 20 parts by mass, preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the polyisocyanate in Liquid B. Incidentally, when the content is less than 0.01 part by mass, the reaction between the amino group in the compound containing a primary and / or secondary amino group and the isocyanate group in the polyisocyanate in Liquid B becomes insufficient, the strength of the resulting solidified body becomes insufficient, or such a reaction does not proceed sufficiently, whereby the formation of the reaction product (foam) may become insufficient. Also, when the content exceeds 20 parts by mass, crosslinking in the reaction product proceeds excessively, an abnormal reaction is caused, solidification occurs during the injection operation, and there is a risk that the desired foam cannot be formed.

[0036] In addition, the Liquid A according to the present invention can further contain various known active hydrogen group-containing compounds as necessary, in addition to the amine compound as described above. Among them, various known polyols that can react with the polyisocyanate component are preferably used.

[0037] And such polyols are not particularly limited, and those conventionally used as the polyol component in the chemical solution for ground consolidation can be similarly used. For example, known polyether polyols, polyester polyols, etc. can be mentioned. These polyols can be used alone or can be used in combination as appropriate. Also, as the addition and blending amount of the polyol, an appropriate ratio is selected so as not to deviate from the gist of the present invention, but generally, it is 40 parts by mass or less, preferably 30 parts by mass or less, more preferably 20 parts by mass or less, relative to 100 parts by mass of the aqueous silicate solution.

[0038] The polyether polyol described above is not particularly limited. For example, polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, and pentaerythritol, which have at least two or more active hydrogen groups; amines such as ethylenediamine; and compounds such as alkanolamines such as ethanolamine and diethanolamine can be used as starting materials, and those produced by an addition reaction of these with alkylene oxides such as ethylene oxide and propylene oxide can be used. Also, in the case of polyester polyol, it is not particularly limited. For example, polycarboxylic acid-based polyester polyols obtained by reacting polyhydric alcohols with polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, maleic acid, phthalic acid, terephthalic acid, trimellitic acid, and dimer acid, lactone-based polyester polyols obtained by ring-opening polymerization of lactones, and castor oil-based polyester polyols can be mentioned.

[0039] On the one hand, as the polyisocyanate which is an essential constituent of the liquid B, one of the two liquids constituting the chemical liquid composition for ground injection targeted by the present invention, in the present invention, from the viewpoints of the strength and reaction rate of the reaction product (foam) obtained by the reaction with the above-mentioned liquid A, an aromatic polyisocyanate will be used. Here, the aromatic polyisocyanate is an organic isocyanate compound having two or more isocyanate groups (NCO groups) in the molecule, and various known ones are appropriately selected and used. For example, diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (crude MDI), tolylene diisocyanate, polytolylene polyisocyanate, xylylene diisocyanate, naphthalene diisocyanate, etc. can be mentioned. Further, prepolymers, isocyanurate-modified products, carbodiimide-modified products, etc. of these aromatic polyisocyanates can be mentioned. These polyisocyanate components may be used alone or in combination of two or more. Generally, from the viewpoints of reactivity, economy, handleability, etc., MDI or crude MDI is preferably used. In addition, as the polyisocyanate in the liquid B, only such aromatic polyisocyanate is used, and other known polyisocyanate components can also be used in combination as long as the gist of the present invention is not deviated from.

[0040] And such an aromatic polyisocyanate as the polyisocyanate is generally contained in the liquid B at a ratio of 50 to 100% by mass, preferably 70 to 100% by mass, more preferably 80 to 100% by mass. When the content of this aromatic polyisocyanate is less than 50% by mass, there is a problem that the strength of the reaction product decreases. Therefore, the ratio of the aromatic polyisocyanate in the liquid B is preferably higher, and furthermore, it is also possible to constitute the liquid B only with such an aromatic polyisocyanate.

[0041] Incidentally, additives similar to those in the prior art can be added to the above-described Liquid A and Liquid B that constitute the base consolidation chemical solution according to the present invention, depending on the purpose of use. For example, additives for Liquid A can include foaming agents, foam stabilizers, flame retardants, viscosity reducers, and the like. Such additives for Liquid A are used in a proportion of 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, based on 100 parts by mass of the polyisocyanate. Also, additives for Liquid B can include foam stabilizers, flame retardants, viscosity reducers, and the like. Among them, the foam stabilizer is used in a proportion of 0.05 to 5 parts by mass, preferably 0.1 to 3 parts by mass, based on 100 parts by mass of the polyisocyanate, and the viscosity reducer is used in a proportion of 0.5 to 60 parts by mass, preferably 1 to 40 parts by mass, based on 100 parts by mass of the polyisocyanate. Further, the flame retardant is used in a proportion of 1 to 50 parts by mass, preferably 5 to 40 parts by mass, based on 100 parts by mass of the polyisocyanate.

[0042] Among these additives, as the foaming agent, known ones such as water, hydrocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluoroolefins, etc. can be used. This foaming agent is not particularly limited, but water is preferably used. This water is also supplied from the aqueous silicate solution that constitutes Liquid A and functions as a foaming agent because it reacts with the polyisocyanate in Liquid B to generate carbon dioxide gas.

[0043] In addition, the foam stabilizer is used to uniformly arrange the cell structure of the foam formed by the reaction of liquid A and liquid B. Examples of such foam stabilizers include silicone, nonionic surfactants, polyoxyalkylene-modified dimethylpolysiloxane, polysiloxane oxyalkylene copolymers, polyoxyethylene sorbitan fatty acid esters, castor oil ethylene oxide adducts, lauryl fatty acid ethylene oxide adducts, etc. Among these, silicone and nonionic surfactants are preferably used. These may be used alone or in combination of two or more. Among the foam stabilizers, silicone-based foam stabilizers are more preferable, and polyoxyalkylene-modified dimethylpolysiloxane, polysiloxane oxyalkylene copolymers, etc. are preferable.

[0044] Furthermore, examples of the flame retardant include brominated flame retardants, chlorinated flame retardants, phosphorus-based flame retardants, halogenated phosphate esters, inorganic flame retardants, etc. These may be used alone or in combination of two or more. Among these, phosphate esters and halogenated phosphate esters are preferably used in terms of having less environmental impact and also functioning as a viscosity reducer for the foaming composition. Examples of the phosphate ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trixylenyl phosphate, etc. Examples of the halogenated phosphate ester include tris(chloroethyl) phosphate, tris(2-chloropropyl) phosphate, tris(dichloropropyl) phosphate, tetrakis(2-chloroethyl) dichloroisopentyl diphosphate, polyoxyalkylene bis(dichloroalkyl) phosphate, etc.

[0045] In addition, the viscosity reducer is used as a solvent and is dissolved in Liquid A or Liquid B to reduce the viscosity of these liquids. As long as it has such a function, it is not particularly limited. For example, alcohols such as methanol and ethanol, ethers such as ethyl cellosolve and butyl cellosolve, cyclic esters such as propylene carbonate, esters such as dimethyl dicarboxylate and ethylene glycol monomethyl ether acetate, petroleum-based hydrocarbons, etc. may be mentioned. These may be used alone or in combination of two or more.

[0046] By the way, Liquid A and Liquid B prepared according to the present invention are each adjusted so that the viscosity at a temperature of 25 °C is 400 mPa·s or less, preferably 5 to 300 mPa·s, more preferably 10 to 200 mPa·s. When this viscosity becomes higher than 400 mPa·s, problems such as an increase in pressure loss when injecting into the natural ground and difficulty in the injection operation will be caused. In addition, if such a viscosity becomes too low, it will be easily diluted by water, and problems such as white turbidity of the drainage will be easily caused.

[0047] Also, when using the ground injection chemical composition according to the present invention composed of such Liquid A and Liquid B, both liquids are mixed at the time of use and injected into the target ground, rock mass, etc. according to a known method, and by being reaction-cured, a high-strength solidified body will be formed. The mixing ratio (A:B) of such Liquid A and Liquid B will be appropriately changed according to the content of active oxygen groups in Liquid A and the content of NCO groups in Liquid B. Generally, on a mass basis, A:B = 2:1 to 1:3, preferably in the range of 1:1 to 1:2, it will be adopted. Also, regarding the method of using these Liquid A and Liquid B, as long as it is a method by which the two liquids can be surely mixed immediately before their use, there is no particular limitation, and various known injection methods will be appropriately adopted.

[0048] When the liquid A and the liquid B are mixed, in the chemical liquid composition according to the present invention, a cured reaction product (foam) having a foaming magnification of generally 20 times or less, preferably 3 to 15 times, is formed at 20°C. It should be noted that if the foaming magnification becomes too high, there is a risk of causing problems such as a decrease in the properties such as the compressive strength of the generated foam.

[0049] Furthermore, when the liquid A and the liquid B are mixed and foamed, the reaction time, in other words, the rise time, is preferably within 300 seconds, and its lower limit is about 20 seconds. If this rise time is longer than 300 seconds, after injection into the ground, until it solidifies, problems such as the chemical liquid flowing out into the spring water and causing white turbidity and foaming of the water will occur. It should be noted that if the rise time is too short, for example, shorter than 20 seconds, problems such as the reaction proceeding too far and blocking the injection pipe of the chemical liquid, or it becoming difficult to sufficiently penetrate the ground will be caused, so attention is required.

Examples

[0050] Several examples and comparative examples of the present invention are shown below to further clarify the present invention more specifically. Needless to say, the present invention is not restricted by the description of such examples. Also, it should be understood that in addition to the following examples, and further beyond the above specific descriptions, various changes, modifications, improvements, etc. can be made based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[0051] In addition, together with the characteristics (viscosity) of the liquid A and the liquid B obtained in the following examples and comparative examples, the foaming magnification, rise time, foaming magnification ratio, compressive strength, and oxygen index of the reaction product when the liquid A and the liquid B are mixed and reactively cured were measured or evaluated according to the following methods respectively. Also, both "%" and "parts" shown below are indicated on a mass basis.

[0052] (1) Viscosity The viscosities of Liquid A and Liquid B obtained in the examples and comparative examples were measured using a B-type viscometer in accordance with JIS-K-7117-1, respectively.

[0053] (2) Foaming ratio and rise time (reaction time) After adjusting the temperatures of various Liquid A and Liquid B shown in the following table to 20 °C or 35 °C respectively, 100 ml in total was weighed into a 1 L cup at the mixing ratios shown below, and stirred at 400 rpm for 10 seconds using hand mixing. Then, the time from the start of the stirring until the foaming height became the highest was defined as the rise time (reaction time). Also, the foaming height of the reaction product after the completion of such a curing reaction was measured visually to determine the foaming ratio. Furthermore, the ratio of the foaming ratio at 20 °C to the foaming ratio at 35 °C thus obtained was calculated. Note that a foam stable against temperature change can be obtained when the 20 °C / 35 °C foaming ratio is within the range of 0.7 to 1.3.

[0054] (3) Foaming stability during foaming at high temperature (35 °C) After adjusting the temperatures of Liquid A and Liquid B with the compositions shown in the following table to 35 °C respectively, 100 ml in total was put into a 1 L cup at the mixing ratios shown in each table, and the process of foaming and curing was observed while stirring. After the completion of the reaction, the foaming ratio after the reaction was compared with the maximum foaming ratio during foaming, and those with a shrinkage of 10% or less from the maximum foaming ratio were rated as "◎", those with 20% or less as "○", and those exceeding 20% as "×" to evaluate the foaming stability.

[0055] (4) Compressive strength Liquid A and Liquid B adjusted to a temperature of 20 °C were weighed in the mixing ratios shown in the following table so that the total amount was 100 ml and mixed. Then, immediately after such mixing, a predetermined amount of the mixture of Liquid A and Liquid B was put into a bottomed cylindrical mold with an inner diameter of 50 mm and a height of 100 mm so that the foaming ratio was 3 times the volume, covered, and cured for 2 hours or more. Thereafter, the demolded reaction product was cured at 20 °C for 24 hours or more, and the compressive strength was measured in accordance with JIS-K-7220:2006.

[0056] (5) Oxygen index Using the foam prepared for the measurement of the above compressive strength, a test piece with a size of 10 mm × 10 mm × 150 mm was cut out, and the oxygen index (%) was measured in accordance with JIS-K-7201-2. This oxygen index evaluates the flame retardancy of the foam. If the value is 27% or more, it is judged that the foam has good flame retardancy.

[0057] First, the following various raw materials were prepared as the components of Liquid A or Liquid B used in the following Examples and Comparative Examples. Aqueous silicate solution : Sodium silicate No. 1 I (product of Fuji Chemical Co., Ltd., molar ratio: 2.1, solid content: adjusted to about 40% by adding water to 48%) : Sodium silicate No. 1 II (product of Fuji Chemical Co., Ltd., molar ratio: 2.1, solid content: adjusted to about 45% by adding water to 48%) : Sodium silicate No. 2 (product of Fuji Chemical Co., Ltd., molar ratio: 2.5, solid content: 40%) Tertiary amine catalyst : Karizer No. 26 (product of Kao Corporation, N,N-dimethylaminoethoxyethanol, MW: 133.2) : Karizer No. 1 (product of Kao Corporation, N,N,N’,N’-tetramethylhexamethylenediamine, MW: 172.3) Primary / secondary amino group-containing compound : Polyetheramine T403 (polyetheramine, product of BASF, molecular weight: 400, functional group: NH2×3) : Ethacure 100 (diethyltoluenediamine, product of Albemarle, molecular weight: 178, functional group: NH2×2) : Ethacure 300 (diethylthiotoluenediamine, product of Albemarle, molecular weight: 214, functional group: NH2×2) : Ethacure 420 [4,4’-methylenebis(N-sec-butylaniline), product of Albemarle, molecular weight: 310, functional group: NH×2] : n-Octylamine [Product of Tokyo Chemical Industry Co., Ltd., molecular weight 129.3, functional group: NH2×1] Polyol : PG (propylene glycol, product of Tokyo Chemical Industry Co., Ltd.) : PP400 (product of Sanyo Chemical Industries, Ltd., Sunnex PP400, polyether polyol, molecular weight: 400, number of functional groups: 2) : PP1000 (product of Sanyo Chemical Industries, Ltd., Sunnex PP1000, polyether polyol, molecular weight: 1000, number of functional groups: 2) : EDP1100 (product of ADEKA Corporation, ADEKA Polyol EDP1100, polyether polyol, molecular weight: 1100, number of functional groups: 4) Aromatic polyisocyanate : Lupranate M11S (product of BASF INOAC Polyurethane Co., Ltd., polymeric MDI) : Lupranate M20S (product of BASF INOAC Polyurethane Co., Ltd., polymeric MDI) : Prepolymer (obtained by adding 5 parts of the above PP1000 to 100 parts of Lupranate M11S and reacting at 70°C for 3 hours) Aliphatic polyisocyanate : Takenate D-170N (product of Mitsui Chemicals, Inc., isocyanurate form of hexamethylene diisocyanate) Foam stabilizer : L-6970 (product of Momentive Performance Materials Japan LLC, silicone-based foam stabilizer) Viscosity reducer : PC (product of Tokyo Chemical Industry Co., Ltd., propylene carbonate) Flame retardant : TMCPP [Product of Daihachi Chemical Industry Co., Ltd., tris(2-chloropropyl) phosphate]

[0058] (Examples 1 to 19) -Preparation of Liquid A- The various raw materials prepared above, namely, the aqueous silicate solution, the tertiary amine catalyst, the primary / secondary amino group-containing compound, and the polyol, were uniformly mixed in the various combinations and blending ratios shown in Tables 1 to 4 below, respectively, to prepare the various A-liquid blended compositions according to Examples 1 to 19. Then, the viscosity of the obtained A-liquid blended composition at 25°C was measured, and the results are shown in Tables 1 to 4 below.

[0059] -Preparation of B-liquid- The various raw materials prepared above, namely, the aromatic polyisocyanate, the foam stabilizer, the viscosity reducer, and the flame retardant, were uniformly mixed in the various combinations and blending ratios shown in Tables 1 to 4 below, respectively, to prepare the various B-liquid blended compositions according to Examples 1 to 19. Then, the viscosity of the obtained B-liquid blended composition at 25°C was measured, and the results are shown in Tables 1 to 4 below.

[0060] -Reaction of A-liquid and B-liquid- The A-liquid and B-liquid obtained above were uniformly mixed and reacted at room temperature (20°C) or high temperature (35°C) in the mixing ratios shown in Tables 1 to 4. Then, various evaluation tests were conducted according to the above-described evaluation methods, and the results are shown in Tables 1 to 4 below.

[0061] (Comparative Example 1) In Example 1, tests were conducted in the same manner as in Example 1 except that the primary / secondary amino group-containing compound was not added. Then, the obtained results are shown in Table 5 below.

[0062] (Comparative Example 2) In Example 13, tests were conducted in the same manner as in Example 13 except that the primary / secondary amino group-containing compound was not added. Then, the obtained results are shown in Table 5 below.

[0063] (Comparative Example 3) In Example 1, tests were conducted in the same manner as in Example 1, except that a tertiary amine catalyst was not added. The results obtained were shown in Table 5 below.

[0064] (Comparative Example 4) In Example 1, tests were conducted in the same manner as in Example 1, except that Takenate D-170N, an aliphatic polyisocyanate, was used instead of the aromatic polyisocyanate. The results obtained were shown in Table 5 below.

[0065] [Table 1]

[0066] [Table 2]

[0067] [Table 3]

[0068] [Table 4]

[0069] [Table 5]

[0070] As is clear from the results of Tables 1 to 4 above, in the chemical liquid compositions comprising Liquid A and Liquid B according to the present invention in Examples 1 to 19, all of them have a reaction time of 300 seconds or less, are excellent in reaction activity, and can form a cured product (foam) having a high compression strength and an excellent oxygen index (flame retardancy) at a foaming magnification of about 3 times or more. Moreover, they are excellent in the reaction time and foaming magnification during high-temperature foaming at 35°C, and as a result, the 20°C / 35°C foaming magnification ratio is within the range of 0.7 to 1.3, indicating that a foam stable against temperature changes can be formed.

[0071] On the other hand, as shown in Table 5, in the chemical liquid compositions comprising Liquid A and Liquid B prepared in Comparative Examples 1 to 4, sufficient cured products (foams) with respect to compression strength and oxygen index (flame retardancy) could not be obtained. Moreover, in addition to the significant shrinkage of the foam during high-temperature foaming at 35°C, it became clear that it was difficult to expect the formation of a foam stable against temperature changes as the 20°C / 35°C foaming magnification ratio deviated from the range of 0.7 to 1.3. In the chemical liquid composition according to Comparative Example 3, since no tertiary amine catalyst was added, the obtained cured product (foam) was easily collapsible and brittle, and it was impossible to measure the compression strength and oxygen index. Further, in Comparative Example 4 using an aliphatic polyisocyanate, the rise time during normal-temperature foaming exceeded 300 seconds. In addition to the problem of a long reaction time, there were problems such as a low foaming magnification and insufficient compression strength.

Claims

1. In a chemical solution composition for ground injection comprising a liquid A containing a silicate aqueous solution and a catalyst as essential components and a liquid B containing a polyisocyanate as an essential component, an aromatic polyisocyanate is used as the polyisocyanate which is an essential component in the liquid B, the liquid A contains a tertiary amine as the catalyst, and further contains a primary and / or secondary amino group-containing compound, which is a chemical solution composition for ground injection.

2. The chemical solution composition for ground injection according to claim 1, wherein the primary and / or secondary amino group-containing compound is a polyamine compound having two or more primary and / or secondary amino groups in one molecule.

3. The chemical solution composition for ground injection according to claim 1 or claim 2, wherein the primary and / or secondary amino group-containing compound has a primary and / or secondary amino group in a proportion of 0.5 to 50 mmol / g.

4. The chemical solution composition for ground injection according to any one of claims 1 to 3, wherein the primary and / or secondary amino group-containing compound is an aromatic amine compound.

5. The chemical solution composition for ground injection according to any one of claims 1 to 4, wherein the primary and / or secondary amino group-containing compound is contained in a proportion of 0.01 to 20 parts by mass with respect to 100 parts by mass of the polyisocyanate.

6. The chemical solution composition for ground injection according to any one of claims 1 to 5, wherein the tertiary amine as the catalyst has an alcoholic hydroxyl group.

7. The chemical solution composition for ground injection according to any one of claims 1 to 6, wherein the liquid A further contains a polyol.

8. The chemical solution composition for ground injection according to any one of claims 1 to 7, wherein the liquid A and the liquid B each have a viscosity of 400 mPa·s or less at a temperature of 25°C.

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