JPH0139691B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a surface layer coating agent for field deposits for protecting the surface layer of field deposits made of granular coal or ore particles. [Prior Art] An emulsion of an acrylic ester resin or a mixture of an acrylic ester and vinyl acetate, styrene, etc. is used as a surface coating agent to protect the surface layer of the field deposits and prevent the scattering of dust and penetration of rainwater. Emulsions of copolymer resins have been used. These chemicals are used by directly spraying on piled coal, etc., or by compacting the surface layer and then spraying it (for example, in Japanese Patent Application Laid-Open No. 1983-1999).
No. 148443). Also proposed are combinations of anionic resin emulsions and cationic resin emulsions, or combinations of cationic resin emulsions and anionic water-soluble resins. The above-mentioned anionic or cationic emulsion is an aqueous emulsion made of a nonionic resin with an anionic or cationic emulsifier, and sodium polyacrylate is used as the anionic water-soluble resin. By using these emulsions in combination with those with opposite charges, the emulsion is broken and a solidified layer is formed on the surface (for example,
No. 38524). [Problems to be Solved by the Invention] However, among such conventional surface coating agents, those that use a resin emulsion alone have problems because the agent is an aqueous emulsion.
It takes a considerable amount of time to dry or form a film, and not only does it have no effect on preventing rainwater from penetrating into rain immediately after spraying, but the rainwater also causes the chemical to flow out and form a solidified layer even after drying. Without,
There were problems such as the sprayed chemicals being wasted. In addition, products that are used in combination with emulsions, etc., form a consolidated layer on the surface layer with nonionic resin, so the consolidated layer is fragile and does not have sufficient water repellency, and is not sufficient to prevent dust scattering and rainwater penetration. There were problems such as not being able to do it. This invention is intended to solve the above-mentioned problems.The formation of a compacted layer is fast, and even if it rains immediately after spraying, the compacted layer can be formed, and the compacted layer that is formed is strong and excellent. The object of the present invention is to provide a surface coating agent for field deposits that has water repellency. [Means for Solving the Problems] The present invention provides an emulsion of a resin having an ionic structural unit, and a resin having an ionic or nonionic structural unit having the same ionicity as the ionicity. This is a surface coating agent for field deposits made of granular coal or ore, which is characterized by containing a resin emulsion emulsified with a synthetic emulsifier. A resin having an ionic structural unit is a resin having a cationic or anionic structural unit in the resin structure, and is a polymer of a monomer having a cationic group, and a cationically or anionically modified polymer of a nonionic resin. There are things. Emulsions of resins having ionic structural units are obtained by emulsifying these resins in water as an aqueous emulsion. The cationic structural units of these resins include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, quaternary compounds of dimethylaminoethyl acrylate, quaternary compounds of dimethylaminoethyl methacrylate, methacrylamide propyltrimethylammonium chloride, dimethylaminopropyl Anionic structural units such as methacrylamide, 2-hydroxy-3-methacryloxypropylmethylammonium chloride, and vinylpyridine include acrylic acid, methacrylic acid, crotonic acid, itaconic acid,
Examples include maleic acid and fumaric acid, and one or more of these may be included. In addition to cationic or anionic structural units, the above resins include vinyl acetate, vinyl propionate, vinyl versatate, vinyl stearate, acrylate, methacrylate, maleate, fumarate, and ethylene. , butadiene, chloroprene, isopropylene, acrylonitrile, styrene, α-methylstyrene, vinyl chloride, vinylidene chloride, acrylamide, methylol acrylamide, glycidyl methacrylate, and the like. In order to improve film-forming properties and water repellency of the film, it is preferable to include an acrylic ester having an alkyl having 3 or more carbon atoms. As the emulsifier for emulsifying these resins into an aqueous emulsion, nonionic ones are preferable, but cationic ones are preferable for resins with cationic structural units, and cationic ones are used for resins with anionic structural units. may be anionic. Examples of emulsifiers include surfactants and protective colloids. Nonionic emulsifiers include polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid ester, etc., and cationic emulsifiers include aliphatic hydrocarbon groups. Primary amine salts, secondary amine salts, tertiary amine salts, quaternary ammonium salts, etc. Anionic emulsifiers include sodium dialkyl sulfosuccinate, sodium alkylnaphthalene sulfonate,
Sodium dodecylbenzenesulfonate, ammonium lauryl sulfate, triethanolamine lauryl sulfate, sodium higher alcohol sulfate, sodium lauryl sulfate, sodium salt of naphthalene sulfonic acid formalin condensate, sodium polyoxyethylene alkyl phenol ether sulfate,
Examples include sodium polyoxyethylene alkyl ether sulfate and triethanolamine polyoxyethylene alkyl ether sulfate, and one or more of these can be used. Further, examples of the protective colloid include polyvinyl alcohol. The amount of cationic or anionic structural units contained in the resin is preferably 0.1 to 20% by weight, and the solid amount of these resins in the emulsion is 5% by weight.
-60% by weight, and the amount of emulsifier is preferably 0.1-5% by weight. A resin emulsion emulsified with an emulsifier of opposite ionicity is a resin having an ionic or nonionic structural unit that is the same as the ionicity of the resin, and an emulsifier having an ionicity opposite to that of the resin, such as a cationic structural unit. In the case of , the resin is emulsified as an aqueous emulsion using an anionic emulsifier, and in the case of an anionic structural unit, a cationic emulsifier. As the anionic emulsifier and the cationic emulsifier, one or more of the ones listed above can be used, and these can be used in combination with the nonionic emulsifier listed above. The resins to be emulsified with these emulsifiers preferably have nonionic structural units, but may partially contain the same ionic structural units as the resins having ionic structural units. Examples of these nonionic, cationic, and anionic structural units include those listed above, and one or more types of each can be included. The amount of emulsifier in the emulsion is preferably 0.1 to 5% by weight, and the amount of resin solids is preferably 5 to 60% by weight. Emulsions of resins having ionic structural units and resin emulsions emulsified with opposite ionic emulsifiers may be produced by emulsifying each resin in water with the emulsifier, but it is also possible to produce emulsions of resins having ionic structural units and emulsions of resins emulsified with opposite ionic emulsifiers. It is preferable to produce the product in this manner.
For example, in the case of a resin emulsion having an ionic structural unit, the emulsion polymerization method involves emulsifying a cationic or anionic monomer and a nonionic monomer together with the emulsifier and an opposite ionic emulsifier. In the case of,
A nonionic monomer and, if necessary, an ionic monomer are each stirred and dispersed in water together with an opposite ionic emulsifier, and heated while blowing _N2 gas to form benzoyl peroxide, persulfate, and hydrogen peroxide. An aqueous emulsion can be obtained by carrying out emulsion polymerization by adding a catalyst such as the above, or a redox catalyst obtained by combining these oxidizing agents with a reducing agent such as sodium thiosulfate or sodium bisulfite. The emulsion of a resin having an ionic structural unit used in the present invention and the resin emulsion emulsified with an opposite ionic emulsifier each have film-forming properties at room temperature. Here, room temperature film forming property means that when the emulsion is applied onto a clean slide glass plate, the dried product forms a uniform continuous film even at room temperature. In order to enhance film-forming properties and form a continuous film at room temperature, components such as plasticizers, film-forming aids, and other film-forming resins may be added. [Function] Emulsions of resins having ionic structural units and resin emulsions emulsified with opposite ionic emulsifiers can be used as they are or diluted appropriately with water to coat granular coal or ore. 1 to 2.5 per cent on the surface layer of open deposits
m ² and resin solid content at a rate of 10 to 200 g/m ² and mixed in the surface layer. In this case, either one may be sprayed first, but it is preferable to spray the emulsion of the resin having an ionic structural unit first. In either case, after the first spray has penetrated well, the other spray is applied. Further, it is preferable that the surface layer of the field deposit be pressure-molded using a pressure roller or the like, and then the chemical agent is sprayed thereon. When both emulsions are mixed on the surface of the field deposit, the emulsions are destroyed by neutralization of the load, and they are attracted to each other by electrostatic force, forming ionic structural units and the opposite ionic emulsifier. The respective resins form a composite through the process, quickly becoming coarse particles, and then forming a film.
Therefore, the yield of the drug in the surface layer of the field deposit is extremely high, and the amount of the drug flowing out is reduced even when it rains immediately after spraying the drug. The film after drying is water-insoluble, and the solidified layer formed thereby has high strength and good water repellency. [Effects of the Invention] According to the present invention, since a resin composite is formed on the surface layer of field deposits by utilizing the structural units of the resin and the ionicity of the emulsifier, the formation of a consolidated layer is quick, and rainwater is removed immediately after spraying. It is possible to form a consolidated layer even if there is
The formed consolidated layer is strong and has excellent water repellency. This effectively protects the surface layer of open deposits, preventing dust from scattering, crumbling, and rainwater from penetrating. [Examples] Examples of the present invention will be described below. In the examples, % indicates weight %. (1) Methyl methacrylate (MMA) 30%, butyl acrylate (BA) 55%, dimethylaminoethyl acrylate (DDA) 10%, and polyoxyethylene alkyl ether (HLB15-18)
(PEE) 5% was emulsion polymerized by a conventional method, and the solid content was
A 40% emulsion was obtained. (2) Methyl methacrylate 30%, butyl acrylate
55%, acrylic acid (AA) 10%, and sodium alkylnaphthalene sulfonate (SNS)
5% was subjected to emulsion polymerization by a conventional method to obtain an emulsion with a solid content of 40%. (3) Emulsion polymerization of 45% vinyl acetate (VAc), 50% butyl acrylate, and 5% sodium polyoxyethylene alkyl ether sulfate (PES) was performed in a conventional manner to obtain an emulsion with a solid content of 35%. (4) Emulsion polymerization of 45% vinyl acetate, 50% butyl acrylate, and 5% lauryltrimethylammonium chloride (LAC) using a conventional method, and the solid content
A 35% emulsion was obtained. (5) Fill a cylindrical container with a diameter of 10 cm, a height of 10 cm, and a 200 mesh mesh on the bottom, fill it with Goonyella charcoal (2 mm passing through), and add the emulsion diluted to 10% as described in (1) and (3) above. The combinations of (Example 1), (2), and (4) (Example 2) were each sprayed at 2/m ² . After 3 hours of emulsion application, the area was exposed to strong artificial rainfall of 15 mm/hr for 2 hours, and the condition of the consolidated layer was observed.
The results are shown in Table 1. (6) As Comparative Example 1, a 10% diluted solution of the emulsion produced in (1) above was sprayed at 4/ ^m2 , and as Comparative Example 2, a 10% dilution of the emulsion produced in (2) was sprayed.
When a 10% diluted solution of the emulsion produced in (3) was sprayed at 4/m ² as Comparative Example 3, when a 10% diluted solution of the emulsion produced in (3) was sprayed at 4/m ² , as Comparative Example 4, (4)
A 10% diluted solution of the emulsion prepared in 4/
When the emulsion produced in ⁽¹⁾ was sprayed at 2/m ² as Comparative Example 5, the combination of (3) and (4) was sprayed at 2/m ² as Comparative Example 6. When a 0.5% solution of sodium polyacrylate (PAANa) with a molecular weight of 140,000 was sprayed at 2/ ^m2 , as Comparative Example 7, after ^spraying the emulsion prepared in (4) at 2/m2, the polyacrylate of Comparative Example 6 was sprayed at 2/m2. Table 1 also shows the results when the sodium acrylate solution was sprayed at 2/m ² .

【table】

[Table] (7) Next, 1 ton of Goonyella coal was piled up in a conical shape.
A combination of emulsions (1) and (3) above diluted to 10% was applied at 1.5/m ² each (Example 3). 5 hours after spraying, exposed to artificial rain of 10mm/hr for 2 hours,
After that, leave it for a week to dry, then reapply for 20 minutes.
The coal was exposed to artificial rainfall at a rate of mm/hr for 1 hour, and changes in the mountain shape were observed, and the moisture content was measured by sampling coal 15 cm below the surface layer. The results are shown in Table 2. (8) Comparative Example 8 without drug treatment, Comparative Example 9
In the case of the same treatment as Comparative Example 1, Comparative Example
As No. 10, the results of the same treatment as in Comparative Example 2 are also listed in Table 2.

【table】

[Table] From the above results, it can be seen that the samples of Examples form a strong consolidated layer faster than those of Comparative Examples, have good water repellency, and do not crack or collapse due to rain.

Claims (1)

[Scope of Claims] 1. A resin obtained by emulsifying an emulsion of a resin having an ionic structural unit and a resin having the same ionic or nonionic structural unit as the ionicity with an emulsifier having an ionicity opposite to the ionicity. A surface layer coating agent for field deposits made of granular coal or ore, characterized by containing an emulsion. 2. The emulsion of a resin having an ionic structural unit is an emulsion according to claim 1, in which a resin having a cationic or anionic structural unit and a nonionic structural unit is emulsified in water using an emulsifier. Surface coating agent for sediments.