JP2003155450A - Pollutant diffusion-preventing coating material, method for preventing pollutant diffusion, and pollutant diffusion-preventing sheet material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain such a pollutant diffusion-preventing coating material for pollutant diffusion-preventing walls using, for example, a linked wall of steel sheet piles as is previously coated on a joint part of the steel sheet piles and swells after the foundation in a soil owing to the water in the soil to thereby fill a gap at the joint part and furthermore to prevent the pollutant from diffusing by virtue of an effect of a pollutant treatment agent, and to provide a method for preventing the pollutant diffusion as well as a pollutant diffusion- preventing sheet material. SOLUTION: The pollutant diffusion-preventing coating material comprises the essential components of (a) a liquid absorbing resin, (b) a hydrophilic binder resin, (c) a solvent and (d) a pollutant treatment agent, being used when constructing a pollutant diffusion-preventing wall in a soil using a variety of supports, for example a pile such as a steel sheet pile (especially on a joint part), a corrugated plate, an H beam, an I beam, a steel pipe pile, an iron pole, a concrete pile, a pile in such an application way that this coating material is previously coated on a joint part of a variety of supports (for example, on a joint part of steel sheet piles) to thereby display excellent effects on (1) an easy fabrication, (2) little delamination from the supports at the time of foundation, (3) a high swelling ratio (high water-stopping performance by a thin film) and (4) a pollutant fixation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a steel sheet pile joint part in advance, for example, for a contaminant diffusion preventing wall using a steel sheet pile connecting wall, and after the steel sheet pile is driven into the ground, it is grounded. By swelling by absorbing water or liquid contaminants inside,
The present invention relates to a contaminant diffusion preventive paint that prevents contaminants from diffusing by filling voids in joints and fixing contaminants with a contaminant treatment agent such as a heavy metal chelating agent. The present invention also relates to the method for preventing the diffusion of contaminants and the sheet-like contaminant diffusion preventing material.

[0002]

2. Description of the Related Art Conventionally, a method of forming a continuous wall of steel sheet piles around a contaminated soil to protect the contaminants from diffusing and flowing out to the periphery has been used.

However, since a gap of several mm to 1 or 2 cm is inevitably formed in the steel sheet pile joint portion of the steel sheet pile wall, the shielding property is incomplete, and the contaminant diffuses from this joint portion to pollute soil. Had the drawback of expanding. In addition, a method of constructing a continuous wall of soil cement by uniting drill holes into which cement slurry has been injected around contaminated soil is also practiced. However, contaminants may elute through the continuous wall body and contaminants cannot be completely prevented from spreading, and large-scale special heavy equipment such as an excavator (auger) and a large amount of raw materials such as cement are required. The construction was extremely complicated and uneconomical. Furthermore, JP-A-11
Japanese Patent Publication No.-5074 proposes a method of constructing a continuous wall of soil cement by uniting drill holes into which cement slurry containing a heavy metal fixing agent is injected. However, even with this method, the elution of heavy metals cannot be completely prevented, contaminants other than heavy metals cannot be removed, and a large excavator (auger) is used in the continuous wall construction.
There is a problem that a large amount of cement raw material is required, the construction is extremely complicated and the cost is high, and the preparation period and the construction period are extended.

Further, although the contaminants diffuse due to the difference in the concentration of the contaminants in the ground, it is considered that there is a possibility that a certain degree of effect may be exhibited for the present purpose of preventing the diffusion, because of the difference in the groundwater pressure. A water-stopping material for stopping the water flowing out is considered, and is disclosed in JP-A-59-166567 and JP-B-4-25990.
Proposes a coating agent (water blocking agent) using an NCO-terminated urethane prepolymer obtained by reacting a polyether polyol and an organic diisocyanate. However,
Since the coating film itself has water absorption, this product has a low swelling ratio (to balance adhesion and water absorption during swelling).
Thick coating is necessary to fill wide (about 5-10 mm) gaps, and therefore the coating film is liable to peel off when the steel sheet pile is placed, and its performance when used as a contaminant diffusion prevention material It had a drawback that it could not be sufficiently exhibited in many cases. Furthermore, since the main composition is a polyether polyol, the chemical stability is also insufficient, and deterioration during absorption of groundwater (particularly chemicals other than water) is likely to occur, causing problems with long-term physical properties.

Further, Japanese Patent Publication No. 6-96688 proposes a water-swellable coating composition (water-stopping material) comprising an organic solvent solution of an ionizable water-absorbing polymer, a polyvalent metal compound and an elastomer. However, since the water-absorbent polymer is further cross-linked with a polyvalent metal compound and uses an elastomer with low hydrophilicity (not) as a binder, the swelling rate is low and a wide (about 5-10 mm) gap is filled. For this reason, a complicated thick coating is required, so that the coating film easily peels off when the steel sheet pile is placed, and even if it is used as a material to prevent the diffusion of contaminants, the shielding performance is often not sufficiently exhibited. It had a drawback. Furthermore, when it is used for a temporary wall or the like, the elastomer used as a binder is difficult to peel off from the steel sheet pile, and it is extremely difficult to remove it from the steel sheet pile after the extraction and recovery. Thus, up until now, construction is easy, and the support (steel sheet pile joint) at the time of placement
It was the current situation that there was no contaminant diffusion preventive material that peeled off from the soil and had a high swelling ratio (a thin film exerts a high diffusion prevention performance) and had a high contaminant diffusion prevention performance. Further, Japanese Patent No. 3207843 proposes a water-stop coating composition comprising a water-absorbent resin, a hydrophilic binder resin having a specific acid value, and a solvent. This paint has some effect on preventing the diffusion of contaminants, but it is not yet satisfactory.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and its purpose is to facilitate the construction and to provide a support (steel sheet pile joint portion) at the time of driving.
We provide a contaminant diffusion preventive paint, a contaminant diffusion preventive work, and a sheet-like contaminant diffusion preventive material, which has a high degree of swelling rate (exhibits a high diffusion preventing performance in a thin film) and has a high swelling rate. It is to be.

[0007]

In order to solve the above-mentioned problems, the contaminant diffusion preventing coating composition of the present invention comprises a liquid-absorbent resin (a), a hydrophilic binder resin (b), a solvent (c) and a stain. It is characterized in that the substance treating agent (d) is an essential component.

According to the above construction, the application to the support is facilitated, and the work can be performed with a lightweight mechanical device and in a short period of time. It is possible to obtain a contaminant diffusion preventing coating which is less likely to peel off and which is excellent in fixing contaminants.

In order to solve the above-mentioned problems, the more preferred contaminant diffusion preventing coating of the present invention is characterized in that the contaminant treating agent is a heavy metal chelate resin.

According to the above-mentioned constitution, it is possible to fix a heavy metal contaminant such as hexavalent chromium, and to obtain a contaminant diffusion preventing coating which is particularly excellent in the contaminant diffusion preventing property.

In order to solve the above-mentioned problems, the contaminant diffusion preventing coating composition of the present invention comprises an oil absorbing resin (e), a hydrophilic binder resin (b) and a solvent (c) as essential components. It has a feature. According to the above-mentioned constitution, it is possible to obtain a contaminant diffusion preventing coating which is easy to apply, has a high swelling rate, is hardly peeled off from the support, and is particularly excellent in absorbing and fixing ability of oily contaminants.

Further, in order to solve the above-mentioned problems, a preferable method for preventing the diffusion of contaminants using the contaminant diffusion-preventing coating material of the present invention is to previously form the contaminant diffusion preventing coating material of the present invention on the surface of a support, It is characterized in that the support is placed around the contaminated soil. According to the above configuration, it is possible to provide a contaminant diffusion preventing method which is particularly easy to apply, has a high swelling rate, is less likely to be peeled from the support, and is excellent in fixing contaminants. Further, in order to solve the above problems, the method for preventing the diffusion of contaminants of the present invention is a coating material and a contaminant containing the liquid absorbent resin (a), the hydrophilic binder resin (b) and the solvent (c) as essential components. It is characterized in that it is used in combination with a treating agent.

According to the above construction, it is possible to provide a method for preventing the diffusion of contaminants, which is particularly easy to apply, has a high swelling rate, is less peeled from the support, and is excellent in fixing contaminants. Further, the sheet-like contaminant diffusion preventing material of the present invention,
In order to solve the above problems, a coating material containing a liquid-absorbent resin (a), a hydrophilic binder resin (b) and a solvent (c) as essential components is applied and formed on a sheet-shaped substrate. . According to the above configuration, an excellent sheet-like contaminant diffusion preventing material is provided which is particularly easy to apply, has a high swelling rate, is less peeled from the sheet-like base material, and prevents diffusion of contaminants. Also, when it is necessary to pull out and remove the support such as steel sheet pile due to re-construction, it is possible to more reliably prevent adhesion with hydraulic compositions such as hardened cement and concrete (complete edge cutting, reduction of friction resistance). The frictional resistance with the ground at the time of pulling can be greatly reduced. Further, after the removal by withdrawal, there is no adherence of the contaminant diffusion preventing paint or the earth and sand on the surface of the support, and a clean support similar to a new one can be collected, which makes recycling extremely easy.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The contaminant diffusion preventing coating material, the contaminant diffusion preventing method and the sheet-like contaminant diffusion preventing material of the present invention will be described below.

The liquid absorbing resin (a) used in the present invention is
It swells by absorbing water or liquid contaminants, and examples thereof include water-absorbent resins and oil-absorbent resins. The water-absorbent resin is not particularly limited as long as it has a water absorption capacity of 3 times or more (25 ° C., 1 hour) with respect to its own weight. However, the synthetic liquid-absorbent resin obtained by crosslinking a water-soluble or hydrophilic compound (monomer and / or polymer) with a crosslinking agent as exemplified below has a swelling ratio higher than that of natural water-swellable substances (gelatin, agar, etc.), These are preferable to natural water-swellable substances (gelatin, agar, etc.) because they have a good balance of water-soluble content, absorption rate, strength, and the like, and the balance can be easily adjusted.

Specific examples of the above water-absorbent resin include poly (meth) acrylic acid crosslinked products, poly (meth) acrylic acid salt crosslinked products, and poly (meth) acrylic acid having sulfonic acid groups. Ester crosslinked product, poly (meth) acrylic acid ester crosslinked product having a polyoxyalkylene group, poly (meth) acrylamide crosslinked product, copolymerized crosslinked product of (meth) acrylic acid salt and (meth) acrylamide,
Copolymerized crosslinked product of hydroxyalkyl (meth) acrylate and (meth) acrylic acid salt, polydioxolane crosslinked product,
Cross-linked polyethylene oxide, cross-linked polyvinyl pyrrolidone, sulfonated polystyrene cross-linked product, cross-linked polyvinyl pyridine, saponified starch-poly (meth) acrylonitrile graft copolymer, starch-poly (meth) acrylic acid (salt) graft cross-linked copolymer, Examples thereof include a reaction product of polyvinyl alcohol and maleic anhydride (salt), a crosslinked polyvinyl alcohol sulfonate, a polyvinyl alcohol-acrylic acid graft copolymer, and a polyisobutylene maleic acid (salt) crosslinked polymer. These water absorbent resins may be used alone or in combination of two or more. In the present invention, it is preferable to use a salt-resistant water absorbent resin as the water absorbent resin. The reason why the salt-resistant water-absorbent resin is preferable is that the salt-resistant water-absorbent resin has a relatively high water absorption capacity of hard water containing a polyvalent metal, and when used in a contaminant diffusion preventing coating, it does not affect the water quality in the soil so much. Not accept
This is because it swells sufficiently and exhibits sufficient contaminant diffusion preventing performance. The salt-resistant water-absorbent resin of the present invention is not particularly limited as long as it has a water absorption capacity (25 ° C., 24 hours) of 10 times or more in artificial seawater. , Those having a nonionic group and / or sulfonic acid (salt) group are more preferable, and those having an amide group or a hydroxyalkyl group are more preferable. Examples of the salt-resistant water-absorbent resin (e) described above include, for example, copolymerized cross-linked products of (meth) acrylate and (meth) acrylamide, hydroxyalkyl (meth) acrylate and (meth) acrylate. And the like. Further, those having a polyoxyalkylene group are particularly preferable. As such a water absorbent resin, for example, a (meth) having a methoxypolyoxyalkylene group
Examples thereof include a cross-linked copolymer of an acrylic ester and a (meth) acrylic acid salt. These salt-tolerant water-absorbent resins have the properties of water in soil (soft water, soft water,
It swells up to a certain rate regardless of hard water, etc., and can more reliably exhibit sufficient contaminant diffusion prevention performance. Further, the method for producing the water absorbent resin according to the present invention is not particularly limited, for example, a method for polymerizing a monomer component containing a water-soluble ethylenically unsaturated monomer and, if necessary, a crosslinking agent. Is mentioned. The liquid-absorbent resin (a) obtained by (co) polymerizing a water-soluble ethylenically unsaturated monomer is more excellent in water absorbency with respect to water and is generally inexpensive. The cross-linking agent is not particularly limited. Specific examples of the above ethylenically unsaturated monomer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, citraconic acid, vinyl sulfonic acid, and (meth) allyl sulfonic acid. Two
-(Meth) acrylamido-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2
-(Meth) acryloylpropanesulfonic acid, and
Alkali metal salts and ammonium salts of these monomers; N,
N-dimethylaminoethyl (meth) acrylate and its quaternary compounds; (meth) acrylamide, N, N-
Dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, diacetone (meth) acrylamide, N-isopropyl (meth) acrylamide,
(Meth) acrylamides such as (meth) acryloylmorpholine, and derivatives of these monomers; hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; polyethylene glycol Polyalkylene glycol mono (meth) acrylates such as mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate, methoxypolypropylene glycol mono (meth) acrylate; N-vinyl-2-
N-vinyl monomers such as pyrrolidone and N-vinylsuccinimide; N-vinyl amide monomers such as N-vinyl formamide, N-vinyl-N-methyl formamide, N-vinyl acetamide and N-vinyl-N-methyl acetamide Vinyl vinyl ether; and the like, but are not particularly limited. These ethylenically unsaturated monomers may be used alone or in combination of two or more.

Of the above-exemplified ethylenically unsaturated monomers, those composed of ethylenically unsaturated monomers having a nonionic group and / or a sulfonic acid (salt) group are more preferable because they have high salt resistance. Examples of the monomer include 2
-(Meth) acrylamido-2-methylpropanesulfonic acid, 2- (meth) acryloylethanesulfonic acid, 2
-(Meth) acryloylpropanesulfonic acid, (meth)
Examples thereof include acrylamide, hydroxyalkyl (meth) acrylate, methoxypolyethylene glycol mono (meth) acrylate and the like. Furthermore, an ethylenically unsaturated monomer having a polyoxyalkylene group is particularly preferable. When two or more ethylenically unsaturated monomers are used in combination as the monomer component, more preferable combinations include, for example, a combination of (meth) acrylic acid alkali metal salt such as sodium acrylate and acrylamide, (meth ) A combination of an alkali metal acrylate and methoxypolyethylene glycol mono (meth) acrylate may be mentioned, but the combination is not particularly limited.

By polymerizing the above-mentioned monomer components,
A liquid absorbing resin (a) is obtained. Also, the liquid-absorbent resin (a)
The average molecular weight and shape, the average particle size, etc. of the may be set according to the composition of the contaminant diffusion preventing paint, the type of binder, the physical properties, the working environment, etc., but are not particularly limited, but the liquid absorbing property The average particle size of the resin (a) is 30 to 800 μm.
Is preferable, 30 to 600 μm is more preferable, and 30
The most preferable range is 400 μm.

When the average particle size of the liquid absorbent resin (a) used in the present invention exceeds 800 μm, the particle size becomes too large, and the liquid absorbent resin (a) is added to the solvent (c) solution of the hydrophilic binder resin (b). The particles of the liquid-absorbent resin (a) are liable to settle when mixed with (1), which is not preferable. On the other hand, if the average particle diameter of the liquid-absorbent resin (a) is less than 30 μm, it will be very difficult to handle (it tends to scatter as fine powder), which is not preferable.

The present invention is characterized by the above-mentioned liquid-absorbent resin (a), hydrophilic binder resin (b), solvent (c) and contaminant treatment agent (d) as essential components, which are excellent contaminants. Provide a material diffusion prevention paint. This contaminant diffusion preventing coating is easy to apply, has a high swelling rate, is less likely to be peeled from the support, and exhibits an excellent effect in fixing contaminants.

The oil-absorbent resin is not particularly limited as long as it has an absorption performance of 0.5 g or more of kerosene per 1 g of the oil-absorbent resin. For example, the solubility parameter (SP value) is 9 or less It is obtained by polymerizing a monomer component containing 50 parts by mass or more of a monomer having one polymerizable group. When it is used as a main component of a monomer having a solubility parameter (SP value) of more than 9 as a main component of a monomer constituting an oil-absorbent resin, only a polymer having insufficient oil absorption performance can be obtained, which is not preferable in some cases. is there. The solubility parameter (SP value) is generally used as a measure of the polarity of a compound, and in the present invention, a value derived by substituting the Hoy cohesive energy constant into the Small calculation formula is used, and the unit is It can be represented by (cal / cm ³ ) ^1/2 .

As the polymerizable group of a monomer having a solubility parameter (SP value) of 9 or less and having one polymerizable group in the molecule, there are radical polymerization, radiation polymerization, addition polymerization, polymerization and the like polymerization. There is no particular limitation as long as it is a polymerizable group capable of polymerizing an oil absorbing polymer. Among them, a monomer having a polymerizable unsaturated group that can easily produce an oil absorbing resin by radical polymerization is particularly preferable. Further, a suitable oil absorbing resin can be produced by ring-opening polymerization or radical polymerization of a norbornene-based monomer. Examples of the monomer having a solubility parameter (SP value) of 9 or less and having one polymerizable unsaturated group in the molecule include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate and butyl. (Meth) acrylate, iso-
Butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-
Octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, phenyl (meth) acrylate, octylphenyl (meth) acrylate, nonylphenyl (meth) acrylate, dinonylphenyl (meth) acrylate, cyclohexyl (meth) Acrylate, menthyl (meth) acrylate, polyalkylene glycol mono (meth) acrylate, alkylpolyalkylene glycol mono (meth) acrylate, poly (di) alkylsiloxane mono (meth) acrylate, isobornyl (meth) acrylate, dibutyl maleate, di Unsaturated carboxylic acid esters such as dodecyl maleate, dodecyl crotonate, didodecyl itaconate; (di) butyl (meth) acrylamide, (di) dodecyl ( Data) acrylamide,
(Meth) acrylamide having a hydrocarbon group such as (di) stearyl (meth) acrylamide, (di) butylphenyl (meth) acrylamide, (di) octylphenyl (meth) acrylamide; 1-hexene, 1-octene, isooctene, Α-Olefins such as 1-nonene, 1-decene, 1-dodecene; alicyclic vinyl compounds such as vinylcyclohexane; allyl ethers having a hydrocarbon group such as dodecyl allyl ether; vinyl caproate, vinyl laurate, palmitic acid Vinyl ester having a hydrocarbon group such as vinyl and vinyl stearate;
Vinyl ether having a hydrocarbon group such as butyl vinyl ether and dodecyl vinyl ether; aromatic vinyl compounds such as styrene, t-butyl styrene, octyl styrene and the like can be mentioned, and one or more of these monomers can be used. You can Among these, as a monomer that gives better oil absorption performance and oil retention performance,
It has at least one aliphatic hydrocarbon group having 3 to 30 carbon atoms, and is alkyl (meth) acrylate, alkylaryl (meth) acrylate, alkyl (meth) acrylamide, alkylaryl (meth) acrylamide,
A monomer containing as a main component at least one unsaturated compound selected from the group consisting of fatty acid vinyl ester, alkylstyrene and α-olefin is particularly preferable. The amount of such a monomer having a solubility parameter (SP value) of 9 or less is 50% by mass or more, and more preferably 70% by mass or more, based on all the monomers. The solubility parameter (SP value) is 9 or less, the amount of the monomer used is 50
If it is less than 10% by mass, only a crosslinked polymer having poor oil absorption performance or oil retention performance may be obtained, which is not preferable. Therefore, it is preferable that 50% by mass or more of a monomer having a solubility parameter (SP value) of 9 or less is contained in all the monomers used for the oil-absorbent resin of the present invention, but 50% by mass of all the monomers is contained.
The solubility parameter (SP value) is 9 at a ratio of not more than mass%.
A monomer having one polymerizable unsaturated group may be contained in a molecule exceeding 1. Examples of such a monomer include (meth) acrylic acid, acrylonitrile, maleic anhydride, fumaric acid, hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, and methoxypolyethylene glycol (meth) acrylate. You can The oil-absorbent resin used in the present invention may absorb 0.5 g or more of kerosene per 1 g of the oil-absorbent resin regardless of whether or not cross-linked, but for the purpose of controlling the oil-absorption ratio and maintaining the gel shape after oil absorption. 96 to 99.999% by mass of a monomer (A) having one polymerizable unsaturated group in the molecule whose main component is a monomer having a solubility parameter (SP value) of 9 or less for the purpose of securing the property. On the other hand, the crosslinkable monomer (B) having at least two unsaturated groups in the molecule is 0.001 to 4% by mass (however, of the monomer (A) and the crosslinkable monomer (B)). It is more preferable that the crosslinkable monomer (B) is contained in the range of 100% by mass). When the amount of the monomer (A) is less than 96% by mass or the amount of the crosslinkable monomer (B) exceeds 4% by mass, the crosslink density of the obtained crosslinked polymer becomes too high to absorb a large amount of oil. Therefore, it is not preferable. Also, the monomer (A)
Is more than 99.999% by mass or the amount of the crosslinkable monomer (B) is less than 0.001% by mass, the solubility of the resulting crosslinked polymer in oil is increased, and the crosslinked polymer is fluidized after oil absorption so that the oil absorbent material It is not preferable because the performance as Examples of the crosslinkable monomer (B) include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth).
Acrylate, polyethylene glycol-polypropylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, N, N'-methylenebisacrylamide, N, N'-propylenebisacrylamide,
Glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, alkylene oxide adduct of polyhydric alcohol (eg glycerin, trimethylolpropane or tetramethylolmethane) and (meth) acrylic Examples thereof include polyfunctional (meth) acrylates obtained by esterification with an acid, divinylbenzene and the like, and one or more kinds of these crosslinkable monomers can be used. The oil-absorbent resin in the present invention includes, for example, polyvinyl alcohol, hydroxyethyl cellulose, a protective colloid agent such as gelatin or sodium alkylsulfonate in an aqueous medium containing the monomer component,
It can be produced by dispersing in the presence of a surfactant such as sodium alkylbenzene sulfonate, polyoxyethylene alkyl ether, and fatty acid soap, and suspension-polymerizing with an oil-soluble radical polymerization initiator. If necessary, the monomer component may be dissolved in a water-insoluble organic solvent and then suspension-polymerized. Examples of the oil-soluble radical polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide and cumene hydroperoxide; 2,2′-azobisisobutyronitrile and 2,2 ′.
Examples thereof include azo compounds such as azobisdimethylvaleronitrile, etc.
It can be used in the range of 1 to 5 mass%. The polymerization temperature is 0 to 1 depending on the type of monomer component and the type of polymerization initiator.
It can be appropriately selected within the range of 50 ° C. Further, as a method for producing the oil-absorbent resin in the present invention, there can be mentioned a method of polymerizing the oil-absorbent resin by bulk polymerization and then performing an operation such as pulverization to adjust the particle size. Bulk polymerization may be carried out, for example, by pouring a monomer component into a mold in the presence of the above-mentioned polymerization initiator and conducting the polymerization under the condition of 50 to 150 ° C. In the present invention, the oil-absorbent resin has an average particle diameter of 0.5 to 500 μm by introducing a pre-suspension step using a homomixer or the like during suspension polymerization and adjusting stirring power during polymerization.
It is preferable to make the granules within the range. If the average particle size of the oil-absorbent resin particles is less than 0.5 μm, the surface area is reduced due to the Mamako phenomenon due to the aggregation of the particles, and it becomes difficult to obtain an oil absorbent having an improved oil absorption rate. If the average particle size of the oil-absorbent resin particles exceeds 500 μm,
It is not preferable because the oil absorption rate decreases as the surface area of the oil absorbing resin decreases.

Polynorbornene rubber can be mentioned as an oil-absorbing resin exhibiting a good oil-absorbing performance. The polynorbornene rubber is a ring-opening polymerization of a monomer obtained by the Diels-Alder reaction of ethylene and cyclopentadiene. You can get it.

The present invention provides an excellent paint for preventing diffusion of contaminants, which comprises the above oil-absorbent resin (e), hydrophilic binder resin (b) and solvent (c) as essential components. The pollutant diffusion prevention coating using this oil-absorbent resin (e) is a contaminant that is easy to apply, has a high swelling rate, and has little peeling from the support, and is particularly excellent in the ability to absorb and fix oily pollutants such as crude oil and gasoline. It becomes a diffusion prevention paint.

A preferred method of using the above-mentioned paint for preventing diffusion of contaminants using the oil-absorbent resin is to apply it to a support such as a steel sheet pile in advance, and use it around the underground tank such as gasoline or gasoline. By embedding and installing the support so as to surround the ground around the site of the stand,
One method is to prevent the diffusion of oil from the underground tank. Further, it is also suitably used for oil treatment applications such as prevention of liquid dripping from the oil supply nozzle and solidification treatment of waste engine oil.

Next, the hydrophilic binder resin (b) constituting the contaminant diffusion preventing coating material of the present invention will be described.

The hydrophilic binder resin (b) used in the present invention is water-soluble or water-swellable, has a function of fixing the liquid-absorbent resin (a) as a binder to a support, and a solvent. There is no particular limitation as long as it is soluble in (c), and examples thereof include (meth) acrylic acid ester copolymers, polyurethanes, polyesters, polycarbonates, polyvinyl alcohol resins, and polyvinyl acetate partial hydrolysates. , Ethylene-polyvinyl alcohol copolymer and the like, and one kind or a mixture of two or more kinds thereof can be used. If the hydrophilicity of the hydrophilic binder resin (b) is too low, the liquid-absorbent resin (a)
The swelling of the pollutant is inhibited, the absorption of moisture in the soil is reduced, and the swelling is not sufficiently performed, so that the contaminant diffusion preventing performance of the contaminant diffusion preventing material is deteriorated, which is not preferable. On the other hand, if the hydrophilicity of the hydrophilic binder resin (b) is too high, the adhesion of the binder to the support during the absorption of water in the soil is too low, and the entire coating film is easily peeled off. Is not preferable because it causes a problem in durability. For the reasons described above, the hydrophilic binder resin (b) preferably has an appropriate hydrophilicity.

The acid value of the hydrophilic binder resin (b) is preferably 40 mgKOH / g or more, more preferably 50 mgKOH / g or more, and more preferably 70 mgKOH / g or more in order to have appropriate hydrophilicity. Things are even more preferable.

The acid value of the hydrophilic binder resin (b) is 40.
If it is less than mgKOH / g, the hydrophilicity becomes too low, which is not preferable.

Further, in order to maintain the binder function when absorbing water, it is preferably 500 mgKOH / g or less, more preferably 300 mgKOH / g or less, and further preferably 200 mgKOH / g or less.

The acid value of the hydrophilic binder resin (b) is 50.
When it exceeds 0 mgKOH / g, the hydrophilicity becomes too high, which is not preferable.

Next, although the glass transition temperature of the hydrophilic binder resin (b) is not particularly limited, the hydrophilic binder resin (b) has high adhesion to a support (steel sheet pile joint portion, etc.) and has a high adhesion to the support (steel sheet pile joint portion). It is preferable that the glass transition temperature is −20 ° C. to 120 ° C. from the viewpoint that it does not easily peel off in a large area during driving. If the glass transition temperature is -20 ° C or lower, the coating film of the contaminant diffusion preventing paint tends to be sticky,
In particular, when the supports after coating are stacked and left to stand, blocking may occur. Further, since the strength of the contaminant diffusion preventing coating is insufficient, it becomes easy to peel off when the support is buried in the soil, which is not preferable. From this, it is more preferable that the glass transition temperature is 0 ° C. or higher. Further, when the glass transition temperature of the hydrophilic binder resin (b) is 120 ° C. or higher, the binder layer becomes too hard, the adhesion to the support and the flexibility of the coating film of the contaminant diffusion preventing coating become poor, and When the support is embedded in the soil, peeling and dropping of the liquid-absorbent resin (a) easily occur, which is not preferable. From this, it is more preferable that the glass transition temperature is 100 ° C. or lower, and if the glass transition temperature is between 0 ° C. and 20 ° C. and between 20 ° C. and 100 ° C., the softening component and the shape-retaining component are It is well balanced and more preferable.

The weight average molecular weight (Mw) of the hydrophilic binder resin (b) is not particularly limited, but it is 30,000.
The range of 0 to 300,000 is preferable, and 50,000 to
The range of 200,000 is more preferable. By using the resin having the above-mentioned weight average molecular weight, it becomes easy to balance the toughness and the solubility in alkaline water of the contaminant diffusion preventing coating.

As the hydrophilic binder resin (b), since the hydrophilicity can be easily adjusted by adjusting the acid value, the alkaline water-soluble resin or the acid value is 40 mgKOH / g.
It is preferred to use ~ 500 mg KOH / g of resin.

The alkaline water-soluble resin of the present invention will be described below. Alkaline water-soluble resin, which is one of the preferable examples of the hydrophilic binder resin (b) constituting the contaminant diffusion preventing paint of the present invention, is 0.4% by mass concentration of NaO.
It is a resin that dissolves in H aqueous solution but does not dissolve in neutral or acidic water. The alkaline water-soluble resin is not particularly limited as long as it has the solubility defined above, and for example, the copolymerization weight of the α, β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith can be used. You can list coalescence.

The above-mentioned solubility in alkaline water is not particularly limited, but the preferred solubility of an alkaline water-soluble resin as a binder resin which can be preferably used in the present invention will be described later. . The term “alkali water-soluble resin” of the present invention may be expressed as an alkali-soluble resin in another expression. It is clearer to use an alkaline water-soluble resin, so
In the present invention, an alkaline water-soluble resin is used.

The solubility of the alkaline water-soluble resin which can be preferably used in the present invention in alkaline water is not particularly limited as long as it does not impair the characteristics of the present invention.

For example, the weight reduction rate of the alkaline water-soluble resin in the following solubility test can be specified. The solubility of the alkaline water-soluble resin that can be preferably used in the present invention in the alkaline water is, for example, a molded body of the alkaline water-soluble resin having a shape of 5 mm or less (for example, a pellet shape of 3 mm as in the Examples, pellets Even if it is not converted, it may be cut so as to have a size of 5 mm or less.) 10 g of 0.4% by mass concentration of NaO
It can be determined by the reduction rate of the weight of the molded article of the alkaline water-soluble resin (d) dissolved in alkaline water after the solution was poured into 500 g of an aqueous solution of H and stirred at 25 ° C. for 24 hours. That is, if there is a resin component that remains undissolved after stirring for 24 hours, it is filtered, washed with water, and the weight after drying is determined. It can be determined by the reduction rate from the weight of the original alkaline water-soluble resin before being subjected to the solubility test. That is, it can be obtained by the percentage of the ratio of <original weight-weight after solubility test> / <original weight>.

As the alkaline water-soluble resin of the present invention,
This value is preferably 50% to 100%. More preferably, it is 60 to 100%. More preferably, it is 70 to 100 mass%.

The method for producing the alkaline water-soluble resin and the hydrophilic binder resin having an acid value of 40 mgKOH / g to 500 mgKOH / g of the present invention is not particularly limited, but the following α, β-unsaturated carboxylic acid monomer is used. A copolymer that can be obtained by polymerization using an unsaturated monomer component composed of a monomer other than the α, β-unsaturated carboxylic acid monomer that can be copolymerized therewith is preferable.

For example, the alkaline water-soluble resin of the present invention and an acid value of 40 mgKOH / g to 500 mgKOH / g.
Used in the production of the hydrophilic binder resin of α, β-
Examples of the unsaturated carboxylic acid monomer include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid and fumaric acid; α, β-such as maleic anhydride and itaconic anhydride. Unsaturated carboxylic acid anhydrides: α, β-unsaturated dicarboxylic acid monoesters such as maleic acid monoester, fumaric acid monoester, itaconic acid monoester and the like can be mentioned. The α, β-unsaturated carboxylic acid monomer may be only one kind or two or more kinds. Of these, acrylic acid and / or methacrylic acid, which are acrylic α, β-unsaturated carboxylic acids, are preferably used because they are inexpensive and have good copolymerizability with other unsaturated monomers.

Next, other monomers copolymerizable with the α, β-unsaturated carboxylic acid monomer include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, stearyl acrylate, methyl methacrylate, ethyl. Esters of (meth) acrylic acid with monohydric alcohol having 1 to 18 carbon atoms such as methacrylate, propyl methacrylate, butyl methacrylate, stearyl methacrylate; acrylonitrile,
Nitrile group-containing vinyl monomers such as methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; hydroxyl group-containing vinyl monomers such as hydroxyethyl acrylate and hydroxypropyl methacrylate; glycidyl methacrylate and the like Epoxy group-containing vinyl monomers; metal salts of α, β-unsaturated carboxylic acids such as zinc acrylate and zinc methacrylate; styrene, α
-Aromatic vinyl monomers such as methylstyrene; Aliphatic vinyl monomers such as vinyl acetate; Halogen-containing vinyl monomers such as vinyl chloride, vinyl bromide, vinyl iodide, vinylidene chloride; Allyl ether Maleic acid derivatives such as dialkyl esters of maleic acid; Fumaric acid derivatives such as dialkyl esters of fumaric acid; Maleimide derivatives such as maleimide, N-methylmaleimide, stearylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide; itaconic acid Itaconic acid derivatives such as mono- and dialkyl esters, itaconic amides, itaconic imides, itaconic amide esters; alkenes such as ethylene and propylene; dienes such as butadiene and isoprene; vinyl ethers; 2- (meth) acryloylpropane Sulfone (Salt), 3-allyloxy-2
Examples thereof include unsaturated monomers having a sulfonic acid (salt) group such as hydroxypropane sulfonic acid (salt), polyalkylene glycol (meth) acrylates, and the like, and are used in one kind or in two or more kinds. be able to.

Among them, as the (meth) acrylic acid alkyl ester, esters having various properties can be easily obtained, and by appropriately combining them, Tg (hardness, softness) of the binder resin can be obtained. , Adhesion to the support can be easily adjusted, and α, β-
The copolymerizability with the unsaturated carboxylic acid monomer is also relatively good, which is preferable.

The above-mentioned (meth) acrylic acid alkyl ester is 30% by mass to 1% based on the total amount of other monomers copolymerizable with the α, β-unsaturated carboxylic acid monomer as 100% by mass.
It is preferably used in an amount of 00% by mass, more preferably 50% by mass or more and 100% by mass or more. More preferably 60 to 100% by mass, still more preferably 70 to
It is 100% by mass. That is, using an acrylic monomer as the other monomer is a preferred embodiment as a form of the alkaline water-soluble resin as the hydrophilic binder resin (b) of the present invention.

The ratio of the above-mentioned α, β-unsaturated carboxylic acid monomer and the unsaturated monomer component consisting of another monomer copolymerizable therewith is not particularly limited, but for example, α, β-
When the unsaturated monomer component composed of the unsaturated carboxylic acid monomer and another monomer copolymerizable with the unsaturated carboxylic acid monomer is 100% by mass, the amount of the α, β-unsaturated carboxylic acid in all the monomer components is The ratio is preferably 7 to 80% by mass based on all the unsaturated monomer components. More preferably, it is 7 to 50 mass%. More preferably, it is 9 to 30 mass%.

The proportion of the α, β-unsaturated carboxylic acid monomer in the total monomers in the alkali water-soluble soluble resin is 7% by mass.
When it is less than 1, the acid value tends to be low and the hydrophilicity tends to be too low. Further, when the ratio exceeds 80% by mass,
Problems tend to occur when the hydrophilicity becomes too high.

Used as a raw material for producing a hydrophilic binder resin of the present invention having an acid value of 40 mgKOH / g or more and 500 mgKOH / g or less, that is, a binder resin obtained by polymerizing the above unsaturated monomer component. Do α,
The amount of the copolymerizable monomer other than the β-unsaturated carboxylic acid monomer is the amount of the monomer composed of the above α, β-unsaturated carboxylic acid monomer and another monomer copolymerizable therewith. The saturated monomer total component is 100% by mass, preferably 93 to 20% by mass in the unsaturated monomer total component. More preferably, it is 93 to 50 mass%. More preferably, it is 91 to 70 mass%.

If the proportion of the α, β-unsaturated carboxylic acid monomer is less than 20%, the hydrophilicity tends to be low, and if it exceeds 93%, the hydrophilicity becomes too high, which is not preferable.

Alkaline water-soluble resin and acid value of 40 m
The production method of the hydrophilic binder resin (b) of gKOH / g to 500 mgKOH / g is not particularly limited, and commonly known polymerization methods such as solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization can be used. Preferably, it is produced by solution polymerization in an organic solvent.

This makes it possible to produce the contaminant diffusion preventing coating composition of the present invention by mixing the liquid absorbing resin as it is with the solution or dispersion containing the alkaline water-soluble resin obtained by solution polymerization. Because.

As the polymerization form, radical polymerization,
Anionic polymerization, cationic polymerization, coordination polymerization and the like can be mentioned, but radical polymerization is preferable as an industrial production method.
Examples of the reaction vessel used for producing the raw material polymer include a tank reactor, a kneader, a tubular reactor such as a static mixer, and the like. These reactors can be used together if necessary. A dropping tank is also used if necessary. The pressure in the reaction vessel may be any of reduced pressure, normal pressure and increased pressure.

The radical polymerization initiator used in the radical polymerization is not particularly limited, but specific examples thereof include 2,2'-azobisisobutyronitrile and
Examples thereof include azo initiators such as 2,2′-azobis (2,4-dimethylvaleronitrile); peroxide initiators such as benzoyl peroxide and di-t-butyl peroxide. These radical polymerization initiators are 2
You may use together more than one kind. The solvent used in the solution polymerization is not particularly limited as long as it does not interfere with the radical polymerization reaction, and examples thereof include alcohols such as methanol, ethanol and isopropyl alcohol; aromatic hydrocarbons such as benzene and toluene; acetone. , Ketones such as methyl ethyl ketone; aliphatic esters such as ethyl acetate and butyl acetate, ethylene glycol derivatives such as ethylene glycol and ethylene glycol monomethyl ether,
Examples thereof include propylene glycol derivative products such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate. Two or more kinds of these solvents may be used in combination.

Next, the solvent (c) used in the present invention will be described.

The solvent (c) can be used without particular limitation as long as it is a known solvent used for ordinary paints and the like. For example, the solvents exemplified in the description of the method for producing the alkali water-soluble resin described above can be used. They can be used alone or in combination of two or more. Further, as a method of selecting the solvent (c), it is preferable to select a solvent having a boiling point, safety and the like suitable for coating on the support. If a solvent with a low boiling point is selected, it has quick-drying properties, and a coating film can be formed in a short time, so that thick coating is easy. If a solvent with a high boiling point is selected, the working time can be extended. By using the organic solvent as the medium, there is no swelling due to water absorption of the liquid-absorbent resin that occurs when a medium containing water is used, and the gelation does not occur, so that the coating operation is facilitated. Also, if a solvent with high volatility such as methyl ethyl ketone or methanol is used, it will be dried in about 10 minutes, and it will be dried much faster than the case where water is used as a medium, so that it is possible to quickly shift to the next work or process. The construction period or the time required for coating the support can be significantly shortened.

As contaminants, hexavalent chromium, cadmium, cyan, lead, arsenic, mercury, alkyl mercury, PC
B, heavy metals such as selenium and organic phosphorus (hexavalent chromium, etc.); dichloromethane, carbon tetrachloride, 1,2-dichloroethane, 1,
Volatile organic compounds such as 1-dichloroethylene, cis-1,2-dichloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene, benzene, 1,3-dichloropropene; heavy oil, light oil , Oils such as gasoline; dioxins and the like.

The contaminant treatment agent (d) used in the present invention
Are those that fix, adsorb, chelate, collect, insolubilize, absorb or react contaminants. Heavy metal chelate resins, activated carbon, geolite, ion exchange resins, sulfides such as sodium sulfide, and phosphoric acid compounds such as orthophosphoric acid. , Iron salts such as ferrous sulfate, reducing agents, microorganisms and the like. Above all, a heavy metal chelate resin and activated carbon are more preferable from the viewpoint of adsorption ability of contaminants and economy. Furthermore, in the case of preventing the diffusion of heavy metals, heavy metal chelating resins are preferable, and the heavy metal chelating agents exhibit excellent performance in immobilizing heavy metal contaminants such as hexavalent chromium, and obtain particularly excellent contaminant diffusion preventing paints. be able to. A plurality of the treating agents may be used.

The pollutant diffusion preventing coating composition of the present invention contains the liquid absorbing resin (a), the hydrophilic binder resin (b), the solvent (c) and the pollutant treating agent (d) described above as essential components. It is characterized by doing. Further, other additives (h) may include other resins, pigments, various stabilizers, various fillers, etc., as long as the effect of preventing the diffusion of contaminants is not impaired.

An excellent feature of the present invention is that the above-mentioned paint for preventing the diffusion of contaminants of the present invention is applied to the surface of a support in advance, and the support is placed in the ground around the contaminated soil or in a state of blocking the diffusion of the contaminant. And a method for preventing the spread of pollutants. According to this method for preventing the diffusion of contaminants, particularly the application to the support (steel sheet pile joint part, etc.) is facilitated, and the work can be performed with a lightweight mechanical device in a short period of time. Exhibits excellent effects in fixing contaminants, etc. with less peeling from the body.

For example, the above-mentioned paint for preventing diffusion of contaminants of the present invention is applied to a steel sheet pile joint portion, and the steel sheet pile is continuously (while connected) cast around the contaminated soil to form a wall for preventing contamination diffusion. . The coating applied to the joint part swells due to moisture in the ground, fills the voids in the joint part, and a contaminant treatment agent such as a heavy metal chelating agent fixes the contaminants, thus reliably preventing the diffusion of contaminants. To do.

The pollutant treating agent may be used together outside the coating composition.

The present invention is characterized by excellent use of a stain-treating agent and a paint containing a liquid-absorbent resin (a), a hydrophilic binder resin (b) and a solvent (c) as essential components. A method for preventing material diffusion is also provided. According to this method for preventing the diffusion of contaminants, particularly, the construction is easy, the swelling rate is high, the peeling from the support is small, and the excellent effect of fixing the contaminants is exhibited.

For example, the above-mentioned paint for preventing the diffusion of contaminants of the present invention is applied to the surface of a steel sheet pile or a joint portion, and a cement hardened layer is prepared by mixing the heavy metal chelate resin formed by the SMW method or the like into the ground around the contaminated soil. A method of continuously inserting the steel sheet pile inside the continuous wall, or a liquid-absorbent resin (basic container) surface filled with a contaminant treatment agent such as a heavy metal chelating agent, activated carbon, and iron powder ( A coating material composed of a), a hydrophilic binder resin (b) and a solvent (c) is applied, and is continuously buried in the ground (ground around the contaminated soil) so that the water permeable container is in contact with the contaminant. There is a method of providing a diffusion prevention layer, in which a contaminant treatment agent having an extremely excellent ability to prevent the diffusion of contaminants is used in combination. In particular, in the latter method using a water-permeable container, the above-mentioned paint applied to the surface of the container comes into contact with groundwater to swell and absorb water to form a hydrogel layer. The container can be extremely easily attached to and detached from the ground (pulled out, placed), and the contaminant treatment agent can be easily replaced.

The ratio of the liquid-absorbent resin (a), the hydrophilic binder (b), the solvent (c) and the contaminant treatment agent (d) to the additive is not particularly limited, but in the contaminant diffusion preventing coating composition of the present invention. In order to fully exhibit the characteristics, the weight ratio ([(a) + (b) of the liquid-absorbent resin (a), the hydrophilic binder (b), the solvent (c) and other additives combined to the whole is combined. ) + (C) + (d)] / [(a) +
(B) + (c) + (d) + (h)] * 100 (%))
Is preferably 50% or more, more preferably 70% or more, most preferably 80% or more. Further, the ratio of the liquid absorbent resin (a), the hydrophilic binder (b), the solvent (c), the contaminant treatment agent (d) and the other additive (h) is not particularly limited, but the contaminant of the present invention is used. The liquid-absorbent resin (a) should be 5 to 6 in order to fully exhibit the characteristics of the anti-diffusion coating.
0% by mass, hydrophilic binder (b) 10 to 70% by mass, solvent (c) 5 to 70% by mass, contaminant treatment agent (d)
Is 5 to 70% by mass, other additives (h) are preferably 0 to 50% by mass, the liquid absorbent resin (a) is 10 to 50% by mass, the hydrophilic binder (b) is 10 to 60% by mass, The solvent (c) is 10 to 60% by mass, and the contaminant treatment agent (d) is 10
-60 mass%, other additives (h) are 0-30 mass%
Is more preferable.

The support to be applied in the present invention is not particularly limited as long as it is a known support used in the construction and civil engineering methods. For example, steel sheet pile (particularly joint portion), corrugated sheet, H-shaped steel, Examples thereof include I-shaped steel, steel pipe piles (steel pipe sheet piles), iron columns, concrete piles, poles, and other piles and plates, and containers such as reinforced baskets. Above all, the spreadability of pollutants and the coatability of paints that prevent spread of pollutants, the workability (placeability, shortening the construction period),
Steel sheet piles are particularly preferable from the viewpoint of economy.

The method for applying the contaminant diffusion preventing coating of the present invention to various supports is not particularly limited as long as it is a known coating method, but for example, a brush, a roller or the like may be used, Spray painting may be performed using a spraying tool such as a resin gun.

Further, a sheet-like contaminant diffusion preventing material formed by applying a contaminant diffusion preventing paint to a sheet-like base material may be attached or wrapped to cover the support.

The present invention is characterized in that a coating material containing the liquid-absorbent resin (a), the hydrophilic binder resin (b) and the solvent (c) as essential components is applied and formed on a sheet-like substrate. We also provide sheet-like contaminant diffusion prevention materials. This sheet-like contaminant diffusion preventive material exhibits an excellent effect of preventing the diffusion of contaminants, particularly because it is easy to apply, has a high swelling rate, and hardly peels from the sheet-like substrate.

For example, it can be used by sticking it on the surface of a support such as a steel sheet pile or by pushing a sheet-like contaminant diffusion preventing material into the gap between the support connecting portions to close it. Depending on the conditions of the construction site, it may be preferable to use such a sheet-like contaminant diffusion preventing material. In addition, when it is necessary to pull out and remove the support embedded in the ground after a lapse of time due to reasons such as re-construction, by forming a sheet-like contaminant diffusion prevention material on the surface of the support, soil and hardened cement ( Adhesion with concrete etc. can be more reliably prevented (complete edge cutting, friction resistance reduction), and the friction resistance with the ground at the time of extraction can be greatly reduced. Further, after the removal by withdrawal, there is no adherence of the contaminant diffusion preventing paint or the earth and sand on the surface of the support, and a clean support similar to a new one can be collected, which makes recycling extremely easy.

The sheet-like contaminant diffusion preventing material of the present invention is a material in which the workability of the above-mentioned contaminant diffusion preventing paint of the present invention is further improved. Although the coating operation of the coating material is simple, the sheet-like coating enables easier attachment and easier construction than the coating operation. Further, since the sheet-like contaminant diffusion preventing material does not require a solvent, the safety of the working environment is extremely high. Further, since the sheet-like contaminant diffusion preventing material has a uniform coating film formed by a coating machine, there is no fear of uneven coating on the surface of the support.

Examples of the sheet-like base material formed by applying a contaminant diffusion preventing coating include, for example, split fiber non-woven fabric (for example, wallif "trade name"), carpet, felt, asbestos cloth, asbestos felt, glass fiber non-woven cloth, Non-woven fabrics such as glass fiber reinforced plastics, stitch-bonded non-woven fabrics, needle-punched non-woven fabrics, etc .; textiles such as flat yarn fibrous fabrics, cotton fabrics, linen fabrics, strip fabrics, synthetic resin fabrics made of polypropylene, etc .; polyester fibers Blended fabrics such as woven fabrics obtained by mixing and spinning cotton and cotton fibers; closed cells and / or open cells inside a material made of polystyrene, polyethylene, polypropylene, vinyl chloride resin, urethane resin, phenol resin, rubber foam, etc. Foam formed from: urethane rubber, silicone rubber, fluorine Elastomer sheet made of rubber, ether rubber, acrylic rubber, butyl rubber, neoprene (chloroprene rubber), butadiene-acrylonitrile copolymer, natural rubber, polyethylene, polypropylene, polyethylene terephthalate, polyamide (nylon), vinyl chloride resin, acrylic resin, etc. Made of plastic sheet, leather sheet or wood sheet, waterproof paper sheet, cardboard sheet or other natural product sheet, synthetic paper,
Metal sheets made of aluminum, iron, copper, silver, etc., alloy sheets made of stainless steel, stainless steel fiber sheets, ceramic fiber sheets, aluminum and iron,
Sheets of metal foil made of copper, silver, etc., alloy metal foil made of stainless steel, etc .; polyethylene, polypropylene,
Net or mesh made of polyethylene terephthalate, polyamide (nylon), vinyl chloride resin, acrylic resin, etc., net or mesh made of aluminum, iron, copper, silver, etc., net or mesh made of alloy such as stainless steel, etc. And the like. Only one type of these materials may be used,
Further, two or more kinds may be used together (composite).

Among the above-mentioned sheet-like base materials, since they are excellent in processability and inexpensive, they are split fiber nonwoven fabric, needle punched nonwoven fabric, flat yarn fiber fabric, cotton fabric, linen fabric, strip fabric, synthetic resin fabric. , And blended fabrics are particularly preferred.

The thickness of the sheet-shaped substrate may be set according to the material, and is not particularly limited, but from the viewpoint of flexibility and storability, it is more preferably 0.01 mm to 10 mm. , 0.05 mm to 8 mm is more preferable, and 0.2 mm to 5 mm is particularly preferable. Also, regarding the basis weight of the sheet-shaped substrate, from the viewpoint of flexibility and storability, it is 10 g / m ^{2 to} 10,000 g.
More preferably in the range of ^{/ m 2, 20g / m 2} ~1,0
The range of 00 g / m ² is more preferable. The tensile strength of the sheet-shaped substrate is more preferably 9.81 N / 2.5 cm (1 kgf / 2.5 cm) or more, from the viewpoint of damage resistance during construction, and 98.1 N / 2.5 cm.
(10 kgf / 2.5 cm) or more, more preferably 294 N / 2.5 cm (30 kgf / 2.5c
It is particularly preferable that it is m) or more. Further, after applying the coating material, a water resistance imparting agent such as a water repellent agent such as an alkali water-soluble resin, a fluororesin, or a silicone resin is treated (applied) within a range that does not significantly impair the liquid absorbency of the absorbent resin. By doing so, it is possible to prevent the absorbent resin from dropping off due to the absorption of rainwater and the sheet-like contaminant diffusion preventing paint from peeling off from the surface of the support or the sheet-like base material before and during the construction. In particular, when the alkaline water-soluble resin is applied, the alkaline water-soluble resin has a pH in the neutral range or acidic range such as rain.
It does not dissolve easily even when it comes into contact with water (water resistant film formation). The amount of the paint layer (resin layer) attached to the sheet-shaped substrate may be set according to the working environment,
Although not particularly limited, from the viewpoint of satisfying both the coating productivity for the contaminant diffusion preventing property and the sheet substrate, and more preferably in the range of ^{1g / m 2 ~10,000g / m 2} , 10 g / m and more preferably within ² range of ~1,000g / m ^2, in the range of 20g / m ² ~500g / m ² is particularly preferred. In addition, the ratio of the contaminant diffusion preventing coating material to 100 parts by mass of the sheet-shaped substrate is 1 part by mass to 10,000 parts by mass from the viewpoint of satisfying both the above-mentioned contaminant diffusion preventing property and the coating productivity on the sheet substrate. The range of 10 parts by mass to 1,000 parts by mass is more preferable, and the range of 20 parts by mass to 500 parts by mass is particularly preferable. The above paint (resin layer) on the surface of the sheet substrate
The method for forming is not particularly limited, but specifically, a method of applying a brush or a roller to the surface of the sheet-like substrate; a method of spraying;
Etc. may be adopted.

[0073]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. The acid value of the hydrophilic binder resin (b) is J
It was measured based on the test method described in application clause 4.3 of IS K6901 "Test method for liquid unsaturated polyester resin". However, when the hydrophilic binder resin (b) does not dissolve in the solvent specified in the test method, a solvent that dissolves was appropriately used and measurement was performed according to the above test method.

The glass transition temperature of the hydrophilic binder resin (b) is measured by Seiko Denshi Kogyo's DSC22.
0C under a nitrogen atmosphere to “JIS K 7121
The method of measuring the transition temperature of plastics "was used.
The condition of the test body is adjusted according to the JIS standard 3. Followed (3).

[Production Example 1] A liquid absorbing resin was prepared by the following method. That is, a kneader equipped with a thermometer and a blade (stirring blade), the inner surface of which was lined with ethylene trifluoride and having a capacity of 1.5 L was used as a reactor, and a methoxy polyethylene glycol methacrylate was used in the reactor. (Molecular weight 512) 53.38 g, methacrylic acid (molecular weight 86.09) 3.56 g, sodium methacrylate (molecular weight 108) 217.69 g, polyethylene glycol diacrylate 1.4 as a crosslinking agent
g and 352.37 g of ion-exchanged water as a solvent were charged. The ratio of the cross-linking agent in the monomer component is 0.14
Mol%.

By flowing hot water of 50 ° C. into the jacket, the above aqueous solution was stirred under a nitrogen gas stream while stirring.
Heated to ° C. Next, the polymerization initiator 2,2′-azobis- (2-amidinopropane) dihydrochloride (molecular weight 2
71.27, chemical product V-50 manufactured by Wako Pure Chemical Industries, Ltd.)
10 g of a 11.0 mass% aqueous solution was added and stirred for 10 seconds, and then the stirring was stopped and the mixture was allowed to stand. The ratio of the polymerization initiator to the monomer component is 0.2 mol%.

The polymerization reaction was started immediately after the addition of the polymerization initiator, and after 90 minutes, the internal temperature reached 100 ° C. (peak temperature). Then, the contents were aged for 30 minutes while flowing warm water of 80 ° C. through the jacket. Thereby, a hydrogel was obtained. After completion of the reaction, the blade was rotated to disintegrate the hydrous gel to a fine state, and then the reactor was inverted to take out the hydrous gel.

The obtained hydrogel was dried at 140 ° C. for 3 hours using a hot air circulation dryer. After drying, the dried product was crushed using a desktop simple crusher (manufactured by Kyoritsu Riko Co., Ltd.). As a result, a liquid absorbing resin (1) having an average particle diameter of 180 μm was obtained.

Production Example 2 Hydrophilic Binder Resin (b)
Was prepared by the following method.

That is, a capacity 5 equipped with a thermometer and a dropping device.
In a 0 L tank type reactor, 0.50 kg of acrylic acid, 2.45 kg of ethyl acrylate, and 0.15 of methyl methacrylate.
kg, the polymerization initiator 2,2′-azobis- (2,4
12 g of dimethyl valeronitrile) and 3 kg of methyl alcohol as a solvent were charged. Also, add 1.15 kg of acrylic acid and 2.0 of methyl acrylate to the dropping device.
kg, methyl methacrylate 3.85 kg, 2,2'-azobis- (2,4-dimethylvaleronitrile) 25 g,
A mixed solution consisting of 7 kg of methyl alcohol was charged.

The above methyl alcohol solution was heated to 65 ° C. with stirring under a nitrogen gas atmosphere and reacted for 20 minutes. Thereby, the polymerization rate of the content was adjusted to 72%. Subsequently, while maintaining the internal temperature at 65 ° C., the above mixed solution was uniformly added dropwise over 2 hours from the dropping device. After the dropping was completed, the contents were aged at 65 ° C. for another 3 hours. After the reaction was completed, the content was mixed with 10 kg of methyl alcohol to give 33% by mass of the hydrophilic binder resin (1).
A methyl alcohol solution was obtained.

The hydrophilic binder resin (1) thus obtained had a weight average molecular weight of 150,000 and an acid value of 130 mgKOH.
/ G. As a result of differential scanning calorimetry of the hydrophilic binder resin (1), the hydrophilic binder resin (1) had two glass transition temperatures in the range of -80 ° C to 120 ° C. Further, the obtained methyl alcohol solution of the hydrophilic binder resin (1) was desolvated using a twin-screw extruder to obtain cylindrical pellets having a diameter of 3 mm and a length of 3 mm. 10 g of the pellets were put into 500 g of a 0.4 mass% sodium hydroxide aqueous solution in a beaker at room temperature and stirred with a magnetic stirrer, 4
It completely dissolved after a lapse of time.

Production Example 3 Hydrophilic Binder Resin (b)
Was prepared by the following method. That is, in a tank-type reactor having a capacity of 50 L equipped with a thermometer and a dropping device, acrylic acid of 0.
58 kg, methyl acrylate 1.725 kg, ethyl acrylate 2.45 kg, methyl methacrylate 2.85 k
g, the polymerization initiator 2,2′-azobis- (2,4-
33 g of dimethylvaleronitrile) and 15 kg of methyl alcohol as a solvent were charged. 65 ° C while stirring the above methyl alcohol solution under nitrogen gas atmosphere
The mixture was heated to room temperature and reacted for 5 hours. As a result, a 33 mass% methyl alcohol solution of the hydrophilic binder resin (2) was obtained. The weight average molecular weight of the obtained binder resin is 10
The acid value was 56 mgKOH / g [Comparative Example 1] Liquid absorbing resin (1) 50 produced in Production Example 1
By mixing and dispersing parts by weight and 150 parts by weight of a 33% by weight methyl alcohol solution of the hydrophilic binder resin (1) produced in Production Example 2, the comparative contaminant diffusion inhibitor (1) according to the present invention is obtained. Obtained.

Then, the obtained comparative contaminant diffusion preventing coating material (1) was applied to a polyethylene substrate 12 mm * 50 mm surface (two surfaces) at a coating thickness of 660 μm (dry coating thickness) and dried. A rectangular parallelepiped type gap (5 mm * 12 mm * 50 mm) in which two surfaces face each other with a gap of 5 mm was created. (Preparation of Void Container shown in FIG. 1) Next, the contaminant diffusion preventing paint applied to the void was swollen with deionized water to close the void, and then the void was filled with deionized water. A 100 ml container (lower container in FIG. 2) was installed, and a 100 ml container (upper container in FIG. 2) having a water permeable hole at the bottom was installed in the upper part of the gap. still,
No air was caught between the closed gap and the container below which was filled with deionized water. (Preparation of Container for Evaluating Contaminant Diffusivity Shown in FIG. 2) Next, 100 ml of an aqueous solution having a hexavalent chromium concentration of 0.5 ppm
Was poured into the upper container, and the hexavalent chromium concentrations in the upper and lower containers were measured after the elapse of time.

After 6 days, the hexavalent chromium concentration in the liquid inside the upper container and the lower container was measured by ICP emission spectrometry. As a result, the hexavalent chromium concentration in the upper container liquid was 0.5 ppm, and the concentration in the lower container liquid was 0.1 ppm.

Comparative Example 2 The procedure of Example 1 was repeated, except that the surface of the polyethylene base material was not coated and the gap was not closed. After 6 days, the concentration of hexavalent chromium in the liquid in the upper container was 0.
25ppm, the concentration of the liquid in the lower container is 0.25ppm
Met. Hexavalent chromium had diffused into the lower container.

[Example 1] A hexavalent chromium adsorbent "K-6" (made by Miyoshi Yushi Co., Ltd.) was used as a comparative contaminant diffusion prevention coating (1).
Was further added in an amount of 50 parts by mass, and mixed and dispersed to prepare a contaminant diffusion preventing coating material (1). After 6 days, the hexavalent chromium concentration in the upper container liquid was 0.3 ppm, and the concentration in the lower container liquid was 0.0 ppm. Hexavalent chromium did not diffuse into the lower container, and the hexavalent chromium concentration in the upper container was also lowered.

[Example 2] The contaminant diffusion preventing paint (1) of Example 1 was dried on a fluororesin sheet to give 200
A μ coating film was prepared. Part of the coating film (about 0.5g)
Cut out and deionize water and artificial seawater (Aquamarine S (manufactured by Yasu Chemical Co., Ltd.) 25L) swelling ratio ((coating weight after swelling-coating weight before swelling) / before swelling) Coating film weight, after immersion at 25 ° C for 24 hours), Water absorption rate (1
The swelling ratio after immersion for 0 minute) was measured, and the results are summarized in Table 1.

As a result, the coating film of the contaminant diffusion preventive coating material (1) of the present invention had a water absorption rate and a swelling ratio (water, artificial seawater).
Both were large and good results.

[Comparative Example 3] In Example 2, a coating film (coating film) of Pilelock NS (manufactured by Nippon Kagaku Paint Co., Ltd., urethane prepolymer type) was used instead of the coating film of the contaminant diffusion preventing coating material (1). The same operation was performed except that the thickness (200 μm) was used, and the swelling ratio ((coating weight after swelling-coating weight before swelling) / coating weight before swelling, after immersion at 25 ° C. for 24 hours), water absorption rate (Swelling magnification after 10 minutes immersion) was measured, and the results are shown in Table 1.
Summarized in. As a result, the coating film of Pile Lock NS (Urethane Prepolymer type manufactured by Nippon Kagaku Paint Co., Ltd.) was poor in both the water absorption rate and the swelling ratio (water, artificial seawater), which was a bad result.

[0091]

[Table 1]

[0092]

Effects of the Invention Contaminants in the ground using various supports, such as steel sheet pile (particularly joint portion) corrugated sheet, H-section steel, I-section steel, steel pipe piles, steel columns, concrete piles, and poles. When creating the diffusion prevention wall, the contaminant diffusion prevention using the liquid absorbent resin (a), the hydrophilic binder resin (b), the solvent (c) and the contaminant diffusion inhibitor (d) of the present invention as essential components By coating the joint part of each support (for example, steel sheet pile joint part) in advance, the coating hardly peels off when the support is placed, and the water in the ground is absorbed quickly after the placement. , Fill the gap by swelling,
Furthermore, by fixing contaminants with a contaminant diffusion inhibitor, etc., it is possible to reliably prevent the contaminant diffusion, exhibit the contaminant diffusion prevention performance at an early stage, and maintain the stable contaminant diffusion prevention performance for a long period of time. . Moreover, the construction is easy.

[Brief description of drawings]

FIG. 1 is a schematic view of a gap on which a contaminant diffusion preventing coating has been applied to measure a contaminant diffusion concentration, which is an index of the contaminant diffusion preventing property of the contaminant diffusion preventing coating of the present invention.

FIG. 2 is a schematic view of an apparatus for measuring a contaminant diffusion concentration, which is an index of the contaminant diffusion preventing property of the contaminant diffusion preventing coating material of the present invention.

[Explanation of symbols]

1 ・ ・ ・ Surface where the contaminant diffusion prevention paint is applied (applied) 2 ・ ・ ・ Contaminant diffusion prevention paint is applied (applied) 3 ・ ・ ・ The contaminant diffusion preventive paint swells and diffuses the contaminant A space that connects to the upper container of the device (Fig. 2) for measuring the diffusion concentration of contaminants.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 7/12 B09B 3/00 304K E02D 5/08 ZAB 5/12 (72) Inventor Kazuhiro Okamura Suita, Osaka Prefecture 5-8 Nishimitabicho, Niigata City, Japan (72) Inventor, Akira Hattori 4-1-1, Koraibashi, Chuo-ku, Osaka City, Osaka Prefecture F-Term (reference) 2D049 FB03 FB05 FB12 FB14 FD04 4D004 AA41 AB03 AC07 CA34 CC04 CC06 CC17 4J038 CB031 CB132 CC092 CE021 CE022 CG032 CG062 CG082 CG141 CG142 CG162 CG172 CH122 CH142 CH262 CK032 CK042 CM022 CP01 HA06 HA06 HA06 HADF26 GA0613 DF02 GA0613 DF02 GA0613 DF022 GA0213 NA07 PB05

Claims (6)

[Claims] 1. A contaminant diffusion preventive coating comprising a liquid-absorbent resin (a), a hydrophilic binder resin (b), a solvent (c) and a contaminant treatment agent (d) as essential components. 2. The contaminant diffusion preventing paint according to claim 1, wherein the contaminant treating agent is a heavy metal chelate resin. 3. A contaminant diffusion preventing paint, which comprises an oil absorbing resin (e), a hydrophilic binder resin (b) and a solvent (c) as essential components. 4. The contaminant diffusion according to claim 1, wherein the contaminant diffusion preventing coating material is applied to the surface of the support in advance, and the support is cast around the contaminated soil. Prevention method. 5. A method for preventing the diffusion of contaminants, which comprises using a paint containing an absorbent resin (a), a hydrophilic binder resin (b) and a solvent (c) as essential components and a contaminant treating agent in combination. . 6. A sheet-like contaminant, which is obtained by applying a coating material containing a liquid-absorbent resin (a), a hydrophilic binder resin (b) and a solvent (c) as essential components to a sheet-like substrate. Diffusion prevention material.