JPS61236867A - Coating agent for open-air storage deposit - Google Patents

Abstract

PURPOSE:A coating agent, consisting of an aqueous solution of an imide group- containing high polymer or polyethyleneimine and a water-soluble dialdehyde, gelable rapidly after application without running off of the chemical even on subsequent rainfall, and useful for consolidating an open-air storage deposit, e.g. open-air storage coal or ore. CONSTITUTION:A coating agent consisting of (A) an aqueous solution of a high polymer having imide bonds, preferably vinyl acetate-maleic anhydride- maleinimide copolymer, isobutylene-maleic anhydride-maleinimide copolymer or vinyl methyl ether-maleinimide copolymer or polyethyleneimine and (B) a water-soluble dialdehyde, preferably glyoxal, malondialdehyde, succinidialdehyde, glutaric dialdehyde, etc., and preferably further (C) an aqueous resin dispersion having film-forming properties at ordinary temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a coating agent for forming a consolidated layer on open deposits such as open coal and ore.

[Conventional technology]

Drained coal, ore, etc. are generally conveyed by a conveyor and stored in piles in an outdoor storage yard using a stacker or the like. When these open deposits are dry, they are blown away by the wind and generate dust, and rainwater permeates through them due to rainfall, increasing their moisture content.

Conventionally, in order to prevent the scattering and increase in moisture content of open deposits, emulsions such as vinyl acetate resin, acrylic resin, latex, etc. were sprayed on the deposits as a coating agent, and dried to form a solidified layer (coating agent). A method has been proposed in which a layer of solidified sediment particles is formed (Japanese Patent Laid-Open No. 31589/1989).

[Problem that the invention seeks to solve]

However, since conventional coating agents use emulsions, a consolidated layer cannot be formed unless the moisture dries after spraying. This drying usually takes 1 to 3 days, depending on the season, weather, etc. , If it rains before drying, the chemical will run off and a solidification layer cannot be formed, making it ineffective. Especially when suppressing rainwater infiltration and preventing an increase in moisture content, solidification is necessary during the rainy season. Although it is necessary to form a layer, there was a problem in that the chemical could not be sprayed due to rain.

This invention is intended to solve the above problems, and by using a hardening type agent, it quickly gels after being sprayed.
The object of the present invention is to provide a coating agent for field deposits that can effectively form a consolidated layer without causing the chemicals to flow out even if it rains afterwards.

[Means for solving problems]

The present invention is a coating agent for open deposits, characterized by comprising an aqueous solution of a polymer compound having an imide bond or polyethyleneimine, and a water-soluble dialdehyde.

Polymer compounds with 100 imide bonds (co>NH structure) include multicomponent copolymers with maleimide bonds, such as vinyl acetate-maleic anhydride-maleimide copolymers, styrene-maleic anhydride copolymers, etc. Acid-maleimide copolymer, isobutylene-maleic anhydride-maleimide copolymer, vinyl methyl ether-maleimide copolymer.

Examples include vinylpyrrolidone-maleimide copolymer, styrene-maleic anhydride copolymer, and isobutylene-maleimide copolymer.
By reacting ammonia with maleic anhydride copolymer,
It may be one in which a part of the maleic anhydride in the molecule is converted into maleimide, and one type or two or more types can be used. These copolymers can be used as an aqueous solution of 3 to 30% by weight, preferably 5 to 15% by weight.

Polyethyleneimine has a molecular weight of 30,000 to 500,000
, preferably 50,000 to 300,000, and can be used as an aqueous solution of 3 to 30% by weight, preferably 3 to 15% by weight. The compound having an imide bond and polyethyleneimine may be used separately.

They may be used in combination.

Water-soluble dialdehydes serve as curing agents, and examples include glyoxal, malondialdehyde, sufu, syndialdehyde, glutardialdehyde, pimeline dialdehyde, and spering dialdehyde, and one or more of these may be used. An aqueous solution of can be used, with glyoxal being particularly preferred.

These dialdehydes can be used as a 0.5 to 10% by weight aqueous solution.

The present invention has the above-mentioned imide bond-containing polymer compound or polyethyleneimine aqueous solution and water-soluble dialdehyde as essential components, but it is preferable to use a resin aqueous dispersion having film-forming properties at room temperature as other components.

As such a resin aqueous dispersion having film-forming properties at room temperature,
Vinyl acetate, vinyl propionate, vinyl versatate, vinyl stearate, acrylic acid ester.

Aqueous homopolymers or copolymers of methacrylic esters, maleic esters, fumaric esters, ethylene, butadiene, chloroprene, isobutylene, acrylonitrile, styrene, vinyl chloride, vinylidene chloride, unsaturated carboxylic acids, acrylamide, methylolacrylamide, etc. emulsion or latex, alkyd resin, epoxy resin, acrylic resin, melamine resin,
Examples include aqueous dispersions (including hydrosil types) such as urea resin, turpentine polymer resin, rosin resin, polyisoprene rubber resin, and urethane resin.
A species or two or more species can be used.

The amount of the resin aqueous dispersion having film-forming properties at room temperature used is 0 to 5000% by weight, preferably 50 to 20% by weight, based on the resin content of the polymer compound having an imide bond and the polyethyleneimine.
00% by weight is appropriate.

It is preferable to use these aqueous resin dispersions having film-forming properties at room temperature together with a crosslinking agent that forms a crosslinking bond with a functional group (for example, a carboxyl group) in the resin. It is preferable to use a polymer compound that can be mixed with polyethyleneimine or aldehyde without reacting, and that can be cross-linked in parallel with their gelation. For example, hydrophilic polyepoxy compounds and polyepoxides of polyols are used. can. The appropriate amount of these crosslinking agents to be used is the amount necessary for gelation or curing by crosslinking.

In addition to the above-mentioned components, the coating agent of the present invention can also contain a curing accelerator, filler, pigment, and other additives.

The coating agent of the present invention is prepared by preparing an aqueous solution of a polymer compound having an imide bond or (and) polyethyleneimine and a water-soluble dialdehyde as separate solutions. When using other components such as a resin aqueous dispersion that can form a film at room temperature, these resin aqueous dispersions can be an aqueous solution of a polymer compound having an imide bond or polyethyleneimine, and one or more of a water-soluble dialdehyde. Although it may be prepared as a mixed solution with both or as a separate solution, it is preferable to use a mixed solution with a polymer compound having an imide bond or polyethyleneimine.

Further, when a crosslinking agent is used, it is preferable to use a mixed solution with a curing agent.

[For production]

The method of using the coating agent for field deposits of the present invention is to form a consolidated layer by spraying each component separately or in a mixed state onto field deposits. The preferred method of use is to separately spray a solution containing a mixture of resin components and a solution containing a curing agent and a crosslinking agent.When spraying separately, the order and number of sprays are not limited.The concentration of the solution to be sprayed is The solid content is preferably about 2 to 10% by weight.

The following methods are available for spraying, and spraying is possible even when the deposited layer is wet.

(2) Sprinkle 25 to 600 g, preferably 50 to 400 g of resin per pile surface on the open pile. - In this case, the entire surface of the heap can be uniformly distributed using a spreader. The chemical may be sprayed only once for each component, but it may be sprayed multiple times.

■ Pressure-form the surface of the pile using a pressure roller or pressure plate, etc., and calculate the average density of the surface layer at a depth of about 40 cm from the surface (the density sampled from each layer that divides the surface into multiple equal parts). After increasing the average value of ) by 5 to 30%, the surface area is sprayed in the same manner as in (2).

Among the above methods, method (1) is particularly preferred.

When an aqueous solution of a polymer compound having an imide bond or (and) polyethyleneimine and a water-soluble dialdehyde are mixed before or by spraying, they react and gel within 3 hours, and then harden and solidify. Conjunctions are formed. After gelation, the drug does not flow out even if it rains, and a solidified layer is formed.

The gelation mechanism of a polymer compound having an imide bond, polyethyleneimine, and water-soluble dialdehyde is as follows (1)
It is presumed that this is based on the formula or [II] formula.

-H Ward -C-C-N- If the coating agent contains components other than a polymer compound having an imide bond, polyethyleneimine, and water-soluble dialdehyde, gelation and curing will occur in a state containing the other components. , other components become dispersed inside the gel-like network structure. Therefore, even if a resin aqueous dispersion that can form a film at room temperature is included, the resin aqueous dispersion dries and forms a film while being covered with a gel-like network structure. After gelation, it will not flow out.
When a crosslinking agent is used together with an aqueous resin dispersion capable of forming a film at room temperature, gelation occurs together with crosslinking, so that the aqueous resin dispersion does not flow out and a stronger consolidated layer is formed.

The consolidated layer prevents scattering due to wind, and also prevents rainwater from penetrating in the event of rainfall, thereby preventing an increase in moisture content. In particular, when an aqueous resin dispersion capable of forming a film at room temperature is added, the solidified layer has excellent weather resistance, and a uniform solidified layer can be maintained for a long period of time.

Since the coating agent for field deposits of the present invention can be used in the form of an aqueous solution, there is no danger of toxicity or fire caused by solvents, and it is easy to dilute with water. can.

〔Effect of the invention〕

According to the present invention, the solidified layer is formed by a polymer compound having an imide bond or polyethyleneimine and a water-soluble dialdehyde.

It gels quickly after being sprayed, and even if it rains afterwards, the chemical will not flow out, and it can effectively form a solidified layer on open deposits, thereby preventing the scattering of sediment and increases in water content. It also has the effect of making the spraying work easier and safer.

〔Example〕

Examples of the present invention will be described below.

Five tons of Goonyella coal was piled up in a conical shape to form a coal pile 0 and then Table 1! Spread the solution evenly so that it becomes 21/n-r, and after 30 minutes, apply the solution ■ in Table 1 to 2nd base/n-r.
(However, in the comparative example, only the ■ solution was sprayed.) 3 hours after spraying the ■ solution, the rainfall intensity was 30.
After exposing the pile pile to artificial rainfall of mm/hr for 30 minutes,
In addition to observing the condition of the surface layer of the pile, we also examined the presence or absence of a consolidated layer by drying it naturally for three days after artificial rainfall. In addition, these piles were left to stand naturally and the state of the consolidated layer was investigated after two months.

The results are also listed in Table 1.

Table 1! Liquid and Solution (2) are solutions of the following drugs diluted with water to the solid content shown in the table, or solutions as they are.

A: Polyethyleneimine aqueous solution B: 15% by weight aqueous solution of glyoxal C: Butyl diacrylate-methyl methacrylate copolymer resin emulsion D: Styrene-butadiene copolymer rubber latex E: Vinyl acetate resin emulsion F: Acid imide copolymer aqueous solution (isobutylene) - A maleic anhydride copolymer is heated to 180°C under an ammonia atmosphere to obtain an isobutylene maleic imide-maleic anhydride copolymer (molar ratio 3:2':1), and the isobutylene-maleic anhydride copolymer is -Maleic anhydride copolymer 40
Parts by weight, 7 parts by weight of industrial 25% ammonia water, and 80 parts by weight of water were placed in a container, heated to a liquid temperature of 85°C, and stirred for 2 hours to uniformly dissolve the acid imide copolymer aqueous solution (solid content: 33 parts by weight). %). ) G: Water-soluble epoxy resin (diethylene glycol diglycidyl ether) From the results in Table 1, it can be seen that in the example, even if it rained 3 hours after the chemical spraying, the chemical did not flow out and a consolidated layer was formed. Recognize. Furthermore, it can be seen that those to which a resin aqueous dispersion having room-temperature film-forming properties was added had an excellent consolidated layer when left for two months, and had weather resistance.

Claims (3)

[Claims] (1) A coating agent for field deposits, comprising an aqueous solution of a polymer compound having an imide bond or polyethyleneimine, and a water-soluble dialdehyde. (2) Polymer compound with imide bond is vinyl acetate-
Maleic anhydride-maleimide copolymer, styrene-
Maleic anhydride-maleimide copolymer, isobutylene-maleic anhydride-maleimide copolymer, vinyl methyl ether-maleimide copolymer, or vinylpyrrolidone-maleimide copolymer, or styrene-maleic anhydride copolymer 2. The coating agent according to claim 1, wherein a part of the maleic anhydride in the molecule is converted into maleimide by combining or reacting the isobutylene-maleic anhydride copolymer with ammonia. (3) The coating agent according to claim 1 or 2, wherein the water-soluble dialdehyde is glyoxal, malondialdehyde, succindialdehyde, glutardialdehyde, pimelinedialdehyde, or sperinedialdehyde.