KR20250113717A - Succinic acid cross-linked biodegradable colored hardener and Manufacturing method thereof - Google Patents

Abstract

The present invention relates to a colored curing agent for suppressing dust, which forms a colored film when sprayed on a subject to be treated, such as soil, and a method for producing the same. The present invention provides a colored curing agent for suppressing dust, which comprises a cross-linked polymer in which a hydrophilic polymer is cross-linked by a cross-linking agent; a coloring agent; a surfactant; and water; and a method for producing the same. According to an embodiment of the present invention, the cross-linked polymer comprises a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product in which polyvinyl alcohol (PVA) and a natural polysaccharide are cross-linked by succinic acid (a cross-linking agent). According to the present invention, after spraying on a subject to be treated, such as soil, a colored, water-resistant, strong film is formed, so that excessive spraying or repeated spraying can be prevented due to the visibility of the color, and the strong water-resistant film has an excellent dust-suppressing effect even in rain or strong winds.

Description

Succinic acid cross-linked biodegradable colored hardener and manufacturing method thereof

The present invention relates to a colored curing agent for suppressing dust, which forms a colored film when sprayed on a subject to be treated, such as soil, and a method for producing the same. According to one embodiment, the present invention relates to a succinic acid cross-linked biodegradable colored curing agent which is harmless to the human body and environmentally friendly, has visibility as a color, and has improved dust suppression ability and water resistance to rain, and a method for producing the same, including a biodegradable cross-linked polymer cross-linked by succinic acid (a cross-linking agent) as an effective ingredient for forming a film.

Dust is generated almost everywhere in human living areas, including on general roads and in various industrial sites, and dust that floats in the air or falls down is usually called flying dust. Dust is generated in large quantities in factories (storage yards), playgrounds, mines, road construction sites, and construction sites for soil, wood flour, lime, ash, coke, coal, cement, and aggregates, for example.

Dust floating in the air (flying dust) contains micro dust the size of micrometers, and this is classified by particle size (diameter). In general, dust with a particle size of 50㎛ or less is classified as TSP (Total Suspended Particles), fine dust with a particle size of 10㎛ or less is classified as PM10 (Particulate Matter 10), and ultrafine dust with a particle size of 2.5㎛ or less is classified as PM2.5 (Particulate Matter 2.5). In particular, fine dust with a particle size of 10㎛ or less is so small that it is invisible to the eye, so it can easily enter the body through the respiratory system. Fine dust that enters the body settles in the bronchi or alveoli, reducing lung function and lowering the body's immune function.

A typical method for suppressing dust is to spray water (sprinkle), which is the cheapest method. However, spraying water (sprinkling) has a low dust suppression effect compared to the amount of water used, and in winter, freezing after spraying increases the risk of workers falling, etc., and in summer, there is the inconvenience of having to continuously spray a large amount of water due to rapid evaporation. In addition, in open-air storage sites for soil or coal, a method of covering dust with a dust-proof screen such as tarpaulin, net, or non-woven fabric is used to suppress dust. However, the method of using a dust-proof screen has the disadvantages of requiring a large number of workers, the risk of installation work, and the cost of disposal after use of the dust-proof screen, and it also has the problem of being easily peeled off by strong winds.

Accordingly, various methods have been proposed to suppress dust, and a representative method is a method of spraying (spraying) a dust suppressant. In general, dust suppressants include hydrophilic polymers (or water-soluble polymers) or inorganic salts and are colorless. For example, Korean Patent No. 10-0494538, Korean Patent No. 10-1057107, Korean Patent No. 10-1293257, and Korean Patent No. 10-1881402 present technologies related to the above.

However, dust suppression agents (or, dust suppression agents) according to prior art have the following problems, for example:

First, the dust suppressant according to the prior art is colorless and not visible. Accordingly, since it is not possible to visually confirm whether the dust suppressant has been sprayed, there are cases where it is sprayed excessively or repeatedly. For example, in a storage site for soil or coal, a large amount of soil or coal is piled up like a mountain, and even though the dust suppressant has already been sprayed, there is a problem that the worker sprays excessively or sprays repeatedly because the area is large and it is colorless and not visible (it is difficult to visually confirm whether it has been sprayed). This increases the consumption of the dust suppressant.

In addition, when using inorganic salts such as calcium carbonate as effective ingredients for dust suppression, there are environmental problems such as the risk of ignition and soil acidification. Above all, dust suppressants according to conventional technology have poor dust suppression effect sustainability and poor water resistance. Accordingly, there are problems such as difficulty in use or reduced dust suppression ability when there is rain (rainy season) or strong winds.

Korean Patent Registration No. 10-0494538 (Registration Announcement on June 10, 2005) Korean Patent Registration No. 10-1057107 (Registration Announcement on August 16, 2011) Korean Patent Registration No. 10-1293257 (Registration Announcement on August 9, 2013) Korean Patent Registration No. 10-1881402 (Registration Announcement on July 24, 2018)

Accordingly, the present invention aims to provide a colored curing agent that can be usefully used as a dust suppressant and a method for producing the same.

Specifically, the present invention aims to provide a colored hardener for suppressing dust, which forms a colored and strong waterproof film after being sprayed on a subject to be treated, such as soil, wood flour, lime, ash, coke and/or coal, thereby preventing excessive spraying or repeated spraying due to the visibility of the color, and which has excellent dust suppression ability even in rain or strong wind due to the strong waterproof film, and a method for producing the same.

In order to achieve the above purpose, the present invention,

It is a colored hardener for suppressing dust that is sprayed on the object to be treated and forms a colored film.

A cross-linked polymer in which a hydrophilic polymer is cross-linked by a cross-linking agent;

Colorant;

surfactants; and

A colored hardener for suppressing dust containing water is provided.

According to an embodiment of the present invention, the hydrophilic polymer comprises polyvinyl alcohol (PVA) and a natural polysaccharide, the crosslinking agent comprises succinic acid, and the crosslinked polymer comprises a succinic acid crosslinked polyvinyl alcohol-polysaccharide crosslinked product in which polyvinyl alcohol (PVA) and the natural polysaccharide are crosslinked by succinic acid. In addition, the natural polysaccharide comprises at least one selected from locust bean gum, gellan gum, carrageenan, and agar.

According to an embodiment of the present invention, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product is produced by cross-linking reactants including polyvinyl alcohol (PVA), a natural polysaccharide, and succinic acid in the presence of a reaction catalyst. At this time, the reaction catalyst includes sodium hypochlorite (NaOCl) and caustic potash (KOH).

In addition, the present invention,

A synthetic step of cross-linking reacting a reactant including polyvinyl alcohol, a natural polysaccharide, and succinic acid in the presence of a reaction catalyst to produce a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product in which the polyvinyl alcohol and the natural polysaccharide are cross-linked by succinic acid; and

A method for producing a colored curing agent for suppressing dust is provided, which comprises a mixing step of mixing a coloring agent, a surfactant, and water into the above-mentioned succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product. At this time, in the synthesis step, sodium hypochlorite (NaOCl) and caustic potash (KOH) are used as the reaction catalyst.

According to an embodiment of the present invention, in the synthesis step, sodium hypochlorite (NaOCl) and caustic potash (KOH) are mixed and used as the reaction catalyst in a weight ratio of 1:0.1 to 0.5, and the reactants are cross-linked under alkaline conditions of pH 9 to 11 and at a temperature of 80°C to 90°C for 3 to 5 hours to produce a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product.

In addition, according to an embodiment of the present invention, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product produced through the above-described synthesis step has a yield of 70% or more, preferably 75% or more, according to the following [mathematical formula].

[Mathematical formula]

Yield (%) = C/(A+B) x 100

(In the mathematical formula above,

A: The total weight of polyvinyl alcohol (PVA) and natural polysaccharide used in the reaction,

B: Weight of the cross-linking agent used in the reaction,

C: Weight of the crosslinked product produced by the reaction.)

According to the present invention, a colored curing agent which can be usefully used as a dust suppressant and has improved properties other than dust suppression ability and a method for producing the same are provided.

Specifically, according to the present invention, dust (flying dust) such as soil, wood powder, lime, ash, coke and/or coal is effectively suppressed, and as a result of its color and visibility, excessive spraying and repeated spraying can be prevented, thereby reducing the amount of use, and a strong waterproof film is formed, so that it can be effectively used even in rain or strong winds. In addition, it has the characteristics of being harmless to the human body and being environmentally friendly.

Figure 1 is a photograph showing a colored hardener being sprayed onto soil according to an embodiment of the present invention.
Figure 2 shows SEM images (a) of PM10 particles before and after spraying of a colored curing agent according to an embodiment of the present invention, and a 3D-Optical Analyzer image (b).

The term "and/or" as used in the present invention is used to mean including at least one or more of the components listed before and after. The term "one or more" as used in the present invention means one or a plurality of two or more.

According to a first aspect of the present invention, a colored curing agent (or dust suppressant) for suppressing dust has visibility and effectively suppresses dust (flying dust, etc.) by forming a colored film after being sprayed on a subject to be treated. According to a second aspect of the present invention, a method for producing the colored curing agent for suppressing dust is provided.

In the present invention, "dust" includes not only flying dust floating in the air, but also fine dust, pollen, etc. Dust includes, for example, dirt, coal dust, stone dust, gypsum powder, cement powder, concrete powder, pollen, and/or smoke. In addition, in the present invention, the treatment target object, that is, the treatment target object to which the colored curing agent (dust suppressant) according to the present invention is applied, includes the treatment target object that generates dust, and/or the treatment target object that is about to generate dust. The treatment target object may include, for example, soil, wood powder, lime, ash, coke, coal, steel mills, concrete, and cement plant stockpiles; various stockpiles such as mines, construction sites, and road construction sites; roads; playgrounds; and/or other bare ground where flying dust is generated by the wind. Hereinafter, in explaining the present invention, the treatment target object will be explained by taking soil, coal, etc. as examples, as the case may be.

The colored curing agent according to the present invention is a dust-suppressing composition for suppressing various types of dust such as flying dust, and includes a cross-linked polymer for forming a film on the surface of a subject to be treated; a coloring agent for imparting a visible color to the film; a surfactant for dispersing and emulsifying each component; and water. According to another embodiment of the present invention, the colored curing agent according to the present invention may further include a non-cross-linked polymer. The colored curing agent according to the present invention may contain the above components in an appropriate amount and have a viscosity of, for example, 50 to 2,000 cps (@ 20°C), and may also have a colored liquid or paste formulation such as white, blue, or green (green mint).

In addition, the method for producing a colored curing agent according to the present invention includes a synthesis step (crosslinking reaction step) of reacting a hydrophilic polymer with a crosslinking agent to produce (synthesize) a crosslinked polymer (crosslinked product) in which the hydrophilic polymer is crosslinked by the crosslinking agent; and a mixing step of mixing a coloring agent, a surfactant, and water into the crosslinked polymer (crosslinked product). According to another embodiment, a non-crosslinked polymer may be further mixed in the mixing step.

The colored curing agent according to the present invention is sprayed on a subject to be treated, such as soil or coal, to form a colored film on the surface of the soil or coal, thereby suppressing the generation or scattering of dust, and also has visibility that can be observed with the naked eye. Specifically, the colored curing agent according to the present invention forms a thin colored curing film after being sprayed on the subject to be treated, and the film has a color such as white, blue, or green (green mint). Since the colored curing agent according to the present invention has visibility as a color when sprayed on the subject to be treated, whether it has been sprayed or not can be confirmed with the naked eye, and accordingly, excessive spraying or duplicate spraying is prevented, thereby preventing overconsumption (reducing amount of use). In addition, the colored curing agent according to the present invention forms a strong waterproof film that does not collapse even in the event of rain (rainy season) or strong winds, and has excellent dust suppression ability and sustainability of dust suppression. In addition, since the colored curing agent according to the present invention is water-soluble or water-dispersible, can be easily diluted in water and used by spraying (spraying), it can be easily used with existing water spraying equipment, and thus has excellent workability. Hereinafter, exemplary embodiments of the present invention will be described.

[1] Crosslinked polymer

The cross-linked polymer is a water-soluble or water-dispersible cross-linked product generated by cross-linking a hydrophilic polymer with a cross-linking agent, and acts as an effective ingredient that forms a film after being sprayed on a subject to be treated. The hydrophilic polymer may include at least one selected from polyvinyl alcohol (PVA) and a natural polysaccharide. The cross-linked polymer includes a polyvinyl alcohol-polysaccharide cross-linked product in which polyvinyl alcohol (PVA) and a natural polysaccharide are cross-linked with a cross-linking agent according to an embodiment of the present invention. At this time, the natural polysaccharide includes at least one selected from locust bean gum (LBG), gellan gum, carrageenan, agar, and the like. In addition, the cross-linking agent includes succinic acid (SA) according to an embodiment of the present invention.

According to a preferred embodiment of the present invention, the crosslinked polymer includes a succinic acid crosslinked polyvinyl alcohol-polysaccharide crosslinked product in which polyvinyl alcohol (PVA) and a natural polysaccharide are crosslinked by succinic acid (SA) (crosslinking agent). According to the present invention, the succinic acid (SA) (C ₄ H ₆ O ₄ ) is a dicarboxylic acid [HOOC-(CH ₂ ) ₂ -COOH] having a carboxyl group (-COOH) functional group at both terminals, which is advantageous in the crosslinking reaction (yield, etc.) between polyvinyl alcohol (PVA) and the natural polysaccharide compared to other carboxylic acids. In addition, according to the present invention, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product produced by cross-linking with the above succinic acid (SA) (cross-linking agent) effectively suppresses dust (flying dust, etc.) while maintaining a film for a long time, so that the dust suppression is highly sustainable, and it also has excellent water resistance so that it does not collapse or run off due to rain or strong wind. In addition, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product is not only harmless to water, but also has environmentally friendly characteristics as it is biodegradable.

In addition, according to the present invention, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product has excellent water resistance compared to other cross-linked products due to its physical/chemical properties, and also has high coloring properties and is homogeneously dispersed and mixed with a coloring agent (color pigment) to improve at least the visibility. Specifically, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product includes ultrafine pores in the cross-linked product itself, so that the coloring agent penetrates into the ultrafine pores and is homogeneously dispersed and mixed with the coloring agent. Accordingly, after being sprayed on soil or the like, it has a characteristic of high visibility by having uniform coloring and soil hiding power over the entire film area.

According to an embodiment of the present invention, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product is produced by cross-linking reactants including polyvinyl alcohol (PVA), a natural polysaccharide, and succinic acid (SA) in the presence of a reaction catalyst (or a reaction initiator). At this time, the reaction catalyst includes sodium hypochlorite (NaOCl) and potassium hypochlorite (KOH).

According to an embodiment of the present invention, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product may include a compound represented by the following [chemical formula 1]. The compound of the following [chemical formula 1] is a cross-linked product produced when locust bean gum (LBG) is used as the natural polysaccharide, in which polyvinyl alcohol (PVA) and locust bean gum (LBG) are cross-linked by succinic acid (SA), that is, a PVA-SA-LBG cross-linked product. The PVA-SA-LBG cross-linked product of the following [chemical formula 1] has at least high adsorption properties for dust and high water resistance for rain, and is advantageous in improving visibility (colorability), and is thus preferably used in the present invention. In the following [chemical formula 1], n is not particularly limited. In the following [chemical formula 1], n can be, for example, an integer greater than or equal to 20, and for specific examples, an integer from 20 to 5,000, or an integer from 50 to 3,000.

[Chemical Formula 1]

The above cross-linked polymer (cross-linked product) is preferably produced (synthesized) by cross-linking reactants including polyvinyl alcohol (PVA), natural polysaccharide and succinic acid (SA) (cross-linking agent) in the presence of a reaction catalyst, at an alkaline condition of pH 9 to 11 and a temperature of 80 to 90° C., for 3 to 5 hours. At this time, the reaction catalyst includes two components, sodium hypochlorite (NaOCl) and caustic potash (KOH), as described above. More specifically, the reaction catalyst uses a mixture of sodium hypochlorite (NaOCl) and caustic potash (KOH), and it is preferable to mix and use the sodium hypochlorite (NaOCl) and caustic potash (KOH) in a weight ratio of 1:0.1 to 0.5. That is, it is recommended to add NaOCl:KOH = 1:0.1 to 0.5 as a reaction catalyst to the above reactants.

In synthesizing the above cross-linked polymer (cross-linked product), if the synthesis is carried out by reaction under conditions such as appropriate pH and temperature in the presence of the above reaction catalyst, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product can be produced in a high yield, and further, a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product which is advantageous in terms of dust suppression ability, water resistance, and visibility (coloring/hiding power) can be produced in a high yield. If the reaction is carried out under the above conditions, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product can be produced in a yield of, for example, 70% or more. Preferably, it can have a yield of 75% or more, and for a specific example, it can have a yield of about 75% to 90%.

The above alkaline conditions (pH 9 to 11), reaction temperature (80° C. to 90° C.), and reaction time (3 to 5 hours) at least improve the reactivity and thereby enhance the yield (production rate) of the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product. When synthesizing the above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product, for example, if the reaction is performed under acidic or neutral conditions, the cross-linking reaction is difficult or the yield of the cross-linked product is significantly reduced. At this time, the alkaline conditions can be adjusted to pH 9 to 11 by using caustic potash (KOH) as a reaction catalyst or separately by adding an alkaline agent such as sodium hydroxide (NaOH). In addition, if the reaction temperature is less than 80° C., the cross-linking reaction is difficult or the reaction speed and yield are reduced. If the reaction time is less than 3 hours, the yield is reduced and the unreacted residual amount increases. In addition, if the reaction temperature exceeds 90℃ or the reaction time exceeds 5 hours, for example, the viscosity may increase, making it difficult to mix homogeneously with other components (colorant and water, etc.) or making it difficult to uniformly discharge/spread when spraying on the object to be treated.

Therefore, when producing (synthesizing) the above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product, it is preferable to react under the above conditions, considering the yield (production rate), reaction speed, and physical/chemical properties. In addition, sodium hypochlorite (NaOCl) and caustic potash (KOH) as the reaction catalysts are involved in the cross-linking reaction, and if these are not added, the cross-linking reaction may be difficult or the yield and reaction speed of the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product may be significantly reduced. That is, the above two reaction catalysts improve at least the yield (production rate) and reaction speed of the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product, and this also promotes the reaction by forming appropriate alkaline conditions.

The above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product can be synthesized, for example, through the reaction of the following [Chemical Formula 2]. The following [Chemical Formula 2] is a case where locust bean gum (LBG) is used as a natural polysaccharide, and specifically, it shows the production reaction of the above [Chemical Formula 1], that is, a cross-linked product of PVA-SA-LBG in which polyvinyl alcohol (PVA) and locust bean gum (LBG) are cross-linked with succinic acid (SA) in the presence of a reaction catalyst (NaOCl/KOH). In the following [Chemical Formula 2], n may be an integer of 20 or more, and for specific examples, may be an integer of 20 to 5,000, or an integer of 50 to 3,000.

[Chemical formula 2]

The reactant for producing (synthesizing) the above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product is an aqueous solution, which may contain, based on the total weight of the reactants, about 5 to 35 wt% of polyvinyl alcohol (PVA), about 2 to 40 wt% of natural polysaccharide, about 0.2 to 12 wt% of succinic acid (SA), and about 0.1 to 10 wt% of a reaction catalyst (a mixture of NaOCl and KOH), and the remaining amount may be water or the like. The polyvinyl alcohol (PVA) may have, for example, a weight average molecular weight of 5,000 to 200,000, 10,000 to 100,000, or 15,000 to 50,000.

The cross-linked polymer (preferably, a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product) described above is not particularly limited, but may be included in an amount of, for example, 5 to 80 wt% based on the total weight of the colored curing agent according to the present invention. At this time, if the content of the cross-linked polymer is less than 5 wt%, the dust suppression ability and water resistance, etc. may be improved due to its use. In addition, if the content of the cross-linked polymer exceeds 80 wt%, for example, the viscosity may increase and the workability may deteriorate during the mixing process. Considering these points, it is preferable that the cross-linked polymer be included in an amount of 8 to 75 wt%, or 10 to 60 wt%, based on the total weight of the colored curing agent according to the present invention.

[2] Colorant

The above coloring agent is for forming a colored film, and can be selected from water-soluble or water-dispersible colored forming materials. The colored curing agent according to the present invention can form a colored film, such as white, blue or green (green mint), by the coloring agent. The colored curing agent according to the present invention has visibility that can be visually identified by the coloring agent after being sprayed on the object to be treated. Accordingly, since the presence or absence of spraying can be confirmed by the naked eye, excessive spraying or repeated spraying can be prevented.

The above coloring agent may be selected from a colored pigment and/or plant extract having a color. The coloring agent is preferably an environmentally friendly material, and for example, one or more selected from calcium carbonate, titanium dioxide (TiO ₂ ), talc, gardenia powder (yellow, blue), and copper phthalocyanine glycols may be used, but is not limited thereto. According to one embodiment, the coloring agent may use a mixture of gardenia powder and copper phthalocyanine glycols. At this time, a green color (green mint) is implemented by mixing gardenia powder (yellow, blue) and copper phthalocyanine glycols, and since these are natural pigment substances (gardenia powder) and FDA-approved substances (copper phthalocyanine), they are harmless to the human body and environmentally friendly.

The coloring agent may be included, for example, in an amount of 0.5 to 30 wt% based on the total weight of the colored curing agent according to the present invention. In this case, if the content of the coloring agent is less than 0.5 wt%, the degree of color expression due to its addition may be minimal. In addition, if the content of the coloring agent exceeds 30 wt%, the content of the crosslinked polymer, etc. may be relatively low, making it difficult to form a good film, or the viscosity may be too high, reducing workability (e.g., spraying, etc.).

[3] Surfactant

The above surfactant is for dispersion and/or emulsification of each component constituting the colored curing agent, and is not particularly limited as long as it enables dispersibility between each component (crosslinked polymer, coloring agent, etc.). A water-soluble natural surfactant can be used as the surfactant, and preferably, a water-soluble nonionic surfactant can be usefully used. When a nonionic surfactant is used as the surfactant, this is preferable because it can improve the dispersibility of the crosslinked polymer (succinic acid crosslinked polyvinyl alcohol-polysaccharide crosslinked product). The surfactant can be selected from, for example, polyoxyethylenes, sorbitans, and/or glucosides, and preferably, at least one selected from sorbitan monooleate, sorbitan monolaurate, lauryl glycoside, and decyl glycoside can be usefully used.

The above surfactant may be included, for example, in an amount of 2 to 10 wt% based on the total weight of the colored curing agent according to the present invention. At this time, if the content of the surfactant is less than 2 wt%, the effect of improving dispersibility, etc. due to its addition may be reduced. In addition, if the content of the surfactant exceeds 10 wt%, foam, etc. may be generated, which may hinder workability for spraying. Considering these points, it is preferable that the surfactant be included in an amount of 3 to 7 wt%.

[4] Water

The water is used as a dispersion and/or dilution solvent, and can be, for example, tap water, distilled water, groundwater, and/or purified water. Water can be included in an amount of, for example, 5 to 50 wt%, 10 to 40 wt%, or 10 to 35 wt% based on the total weight of the colored curing agent according to the present invention, but is not limited thereto.

[5] Non-crosslinked polymer

The non-crosslinked polymer may be added to provide flexibility to the film. In addition, the non-crosslinked polymer may also function as an effective component forming the film. The non-crosslinked polymer is a non-crosslinked polymer and may be selected from water-soluble (hydrophilic) or water-dispersible polymers. The non-crosslinked polymer may include, for example, one or more selected from vinyl acetate (VAc), polyvinyl alcohol (PVA), natural polymers, and copolymers or modified products thereof. The natural polymer may use, for example, one or more natural polysaccharides selected from locust bean gum (LBG), gellan gum, carrageenan, and agar. The non-crosslinked polymer (for example, the non-crosslinked natural polysaccharide) may be included in an amount of, for example, 0.5 to 30 wt%, or 2 to 20 wt%, based on the total weight of the colored curing agent according to the present invention.

[6] Additional ingredients

In addition, the colored curing agent according to the present invention may further contain additional components such as functional ingredients or additives, as needed. The colored curing agent according to the present invention may further contain, for example, a moisturizing agent, a dispersing agent, an antistatic agent, an antifreeze agent, an antifoaming agent, a storage stabilizer, and/or a viscosity modifier. These additional components may be selected from those commonly used, and may be added in an appropriate amount within a range that does not reduce the dust suppression ability. The additional components may be included in an amount of 0.001 to 10 wt%, based on the total weight of the colored curing agent according to the present invention.

The colored curing agent according to the present invention described above has at least the following effects.

First, the colored curing agent according to the present invention forms a film on the surface of a treatment material such as soil or coal to suppress (prevent) the scattering of dust that has flown or is about to fly, and maintains moisture for a long time to ensure the sustainability of the dust suppression effect. In addition, it forms a colored film to provide visibility. Accordingly, it effectively replaces existing dustproof films, and can prevent excessive spraying or repeated spraying due to visibility. In addition, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product in which polyvinyl alcohol (PVA) and natural polysaccharides are cross-linked with succinic acid (SA) (cross-linking agent) forms a film with strong water resistance compared to a simple polymer (non-cross-linked polymer) or existing cross-linked polymers, thereby preventing collapse or running off due to rain (rainy season) or strong winds. Additionally, the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product is biodegradable and environmentally friendly, and it also has excellent water resistance due to its physical/chemical properties, and has high coloring properties and can be homogeneously dispersed and mixed with a coloring agent (color pigment) to improve visibility.

The colored curing agent according to the present invention can be applied to the object to be treated, for example, by a method such as spraying. At this time, when applied by the spraying method, it can be used by being diluted in separate water. According to one embodiment, the colored curing agent can be diluted with water at a weight ratio (or volume ratio) of about 5 to 1,000 times, and can be used by spraying (spraying) the object to be treated. Specifically, the colored curing agent of the present invention: water = 1:5 to 1,000 is diluted to obtain a treatment solution (diluted solution), and then the treatment solution (diluted solution) is sprayed (sprayed) onto the object to be treated, such as soil or coal, using a spraying device (e.g., a sprinkler truck, etc.) to form a film.

[Example]

Hereinafter, manufacturing examples and examples of the present invention are exemplified. The following manufacturing examples and examples are provided only as examples to help understand the present invention, and the technical scope of the present invention is not limited thereby.

[Manufacturing Example] Synthesis of Crosslinked Polymer

< Manufacturing Example 1 >

Polyvinyl alcohol (PVA), locust bean gum (LBG), and water (distilled water) were placed in a reactor equipped with a stirrer and stirred at approximately 70°C to prepare a PVA/LBG solution in which polyvinyl alcohol (PVA) and locust bean gum (LBG) were homogeneously dissolved. In addition, a succinic acid (SA) solution was prepared by dissolving a cross-linking agent, succinic acid (SA) (purchased from Sigma-Aldrich), in water (distilled water). Separately, a NaOCl/KOH solution was prepared by adding and mixing sodium hypochlorite (NaOCl) and potassium hydroxide (KOH) as a reaction catalyst in a weight ratio of 1:0.2 to water (distilled water). Thereafter, a succinic acid (SA) solution was added to the PVA/LBG solution of the reactor, and then the NaOCl/KOH solution was added thereto to prepare a cross-linking reactive solution having a pH of about 10.2. At this time, the cross-linking reactive solution contained about 18 wt% of polyvinyl alcohol (PVA), about 12 wt% of locust bean gum (LBG), about 2.5 wt% of succinic acid (SA), and about 0.6 wt% of a reaction catalyst (NaOCl/KOH) based on the total weight of the solution.

Next, the temperature of the reactor was maintained at a constant temperature of about 85±2℃ under a nitrogen flow under alkaline conditions (pH about 10.2), and the crosslinking reaction was carried out while stirring with a magnetic bar for about 3.5 hours. During the crosslinking reaction, the viscosity increased, so stirring was not performed properly, and the reaction was carried out while increasing the rpm speed of the magnetic bar compared to the initial stage. After the completion of the reaction, it was confirmed that a crosslinked product in a gel state (PVA-SA-LBG crosslinked product) was generated, and the crosslinked product gel was obtained by filtering with filter paper.

< Manufacturing Examples 2 to 5 >

Compared to Manufacturing Example 1, each Manufacturing Example (2 to 4) was performed in the same manner as Manufacturing Example 1 except that the hydrophilic polymer, reaction catalyst, reaction temperature, and time were different. Compared to Manufacturing Example 1, in Manufacturing Example 2, the crosslinking reaction was performed at a lower reaction temperature, and in Manufacturing Example 3, starch was used instead of locust bean gum (LBG) as the hydrophilic polymer. In addition, in Manufacturing Example 4, sodium hypophosphite (NaPO ₂ H ₂ ) was used instead of sodium hypochlorite (NaOCl) as the reaction catalyst, and the reaction time was prolonged, and in Manufacturing Example 5, citric acid (CA) was used instead of succinic acid (SA) as the crosslinking agent. The reaction conditions for the crosslinked products according to each Manufacturing Example are shown in [Table 1] below.

[Experimental Example 1] Yield (%) Evaluation

The yield (production rate) (%) of the crosslinked product according to each of the above manufacturing examples (1 to 5) was evaluated. The yield (%) was calculated according to the mathematical formula below, and the results are shown in [Table 1] below.

[Mathematical formula]

Yield (%) = C/(A+B) x 100

In the mathematical formula above,

A: The total weight of polyvinyl alcohol (PVA) and natural polysaccharide used in the reaction (the total weight of polyvinyl alcohol (PVA) and locust bean gum (LBG) introduced into the reactor),

B: The weight of the cross-linking agent used in the reaction (the weight of succinic acid (SA) introduced into the reactor),

C: The weight of the cross-linked product produced by the reaction (the amount of cross-linked product gel produced, which is the weight of the cross-linked product in a gel state obtained by filtering the solution after the reaction is completed through filter paper).

< Reaction conditions and yield evaluation results for cross-linked products according to each manufacturing example > note hydrophilic polymer Crosslinking agent reaction catalyst Reaction temperature Reaction time transference number Manufacturing example 1 PVA + LBG Succinic acid (SA) NaOCl + KOH 85℃ 3.5 hours 78.4% Manufacturing example 2 PVA + LBG Succinic acid (SA) NaOCl + KOH 70℃ 3.5 hours 73.5% Manufacturing example 3 PVA + starch Succinic acid (SA) NaOCl + KOH 85℃ 3.5 hours 61.2% Manufacturing example 4 PVA + LBG Succinic acid (SA) NaPO ₂ H ₂ + KOH 85℃ 5.5 hours 27.8% Manufacturing example 5 PVA + LBG Citric acid (CA) NaOCl + KOH 85℃ 3.5 hours 43.4%

As shown in the above [Table 1], it was found that the yield (%) of the cross-linked product varied depending on the type of hydrophilic polymer, the type of reaction catalyst, the reaction temperature, and the reaction time. In the case of Manufacturing Examples 1 to 3, it was found that the cross-linked product had a yield of about 61% or more, and in particular, it was found that Manufacturing Example 1 had a high yield of about 78% or more. In contrast, when sodium hypophosphite (NaPO ₂ H ₂ ) was used as a reaction catalyst like Manufacturing Example 4 or citric acid (CA) was used as a cross-linking agent like Manufacturing Example 5, it was found that the yield (%) was reduced.

Therefore, through the above experimental examples (manufacturing examples), it was found that among carboxylic acids, the cross-linking agent for cross-linking between polyvinyl alcohol (PVA) and natural polysaccharides (such as LBG) is advantageous in improving the yield (%) when using succinic acid (SA) rather than citric acid (CA), and further, when using succinic acid (SA) as a cross-linking agent, it is advantageous in improving the yield (%) of the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product when using at least sodium hypochlorite (NaOCl) as a reaction catalyst.

[Example 1]

A stirrer was placed in a container, and water (distilled water) was added thereto, and the crosslinked product (PVA-SA-LBG crosslinked product) according to Manufacturing Example 1 was added thereto. Thereafter, an appropriate amount of a hydrophilic non-crosslinked polymer, a surfactant, and a dispersant was added and stirred. Then, a coloring agent was further added and stirred sufficiently to prepare a colored curing agent in a paste formulation. The hydrophilic non-crosslinked polymer used polyvinyl alcohol (non-crosslinked PVA). The coloring agent used a green mint color prepared by mixing gardenia powder (a mixture of yellow and blue) and copper phthalocyanine glycol. The specific components and contents of the colored curing agent according to this example are shown in [Table 2] below.

[Example 2]

A colored curing agent according to this example was manufactured in the same manner as in Example 1, except that the crosslinked product (PVA-SA-starch crosslinked product) according to Manufacturing Example 3 was used as the crosslinking polymer. The specific components and contents of the colored curing agent according to this example are shown in [Table 2] below.

For each of the colored curing agents manufactured as described above, the water resistance, curing time, and dust suppression ability were evaluated as follows. The results are shown in [Table 2] below.

< Test Example 2 >: Evaluation of water resistance and curing time

A colored curing agent according to each example and comparative example was coated on a glass plate, and then cured (at room temperature, dried) to form a coating film. For each coating specimen, the water resistance was evaluated through a salt spray test. In addition, the curing time was evaluated. The salt spray test was performed under the conditions of a 10 wt% NaCl aqueous solution, a test temperature of 35 ± 0.5°C, a spray pressure of 0.098 ± 0.002 MPa, and a spray amount of 1.4 ml/h at 80 cm2. Salt water was sprayed on each coating specimen for 30 minutes, and then the presence or absence of discoloration and running of the coating film was visually confirmed to evaluate the evaluation. In Table 2 below, if there was no discoloration, it was indicated as “no discoloration,” and if discoloration occurred, it was indicated as “discoloration.” If there was no running, it was indicated as “water resistance,” and if it melted and ran, it was indicated as “dissolved.”

< Test Example 3 >: Evaluation of dust suppression ability

First, a diluted solution was prepared by adding 50 times (by volume) of water to the colored hardener according to each example. Thereafter, each diluted solution specimen was sprayed on a soil pile to harden it, and then the dust suppression ability (flying suppression ability) was evaluated by irradiating a strong wind on the soil pile. Specifically, soil piles were stacked in a closed space, each diluted solution specimen was sprayed on the soil pile to harden it (room temperature, dry), and then a strong wind was irradiated on each soil pile using a blower. If the soil powder hardly flew after the strong wind was irradiated, it was marked as "good", and if the soil powder flew, it was marked as "blown" and is shown in [Table 2] below.

< Evaluation results of composition and characteristics of colored hardener according to each example > note Example 1 Example 2 Crosslinked polymer Manufacturing Example 1 ⁽¹⁾ 48.0 - Manufacturing Example 3 ⁽²⁾ - 48.0 Non-crosslinked polymer PVA 10.0 10.0 Colorant Green Mint ⁽³⁾ 6.8 6.8 Surfactant Decyl glucoside 5.0 5.0 Dispersant Span80 1.2 1.2 Water (distilled water) Remaining amount Remaining amount Water resistance (glass plate coating specimen) Colorless/Waterproof Colorless/Dissolvable Curing time (glass plate coating specimen) About 1.5 hours About 2 hours Dust suppression ability (soil heap spraying specimen) Good Fly
(1) Manufacturing Example 1: Polyvinyl alcohol (PVA) and locust bean gum (LBG)
Crosslinked product crosslinked with succinic acid (SA)
(2) Manufacturing Example 3: Polyvinyl alcohol (PVA) and starch with succinic acid (SA)
Cross-linked cross-linked material
(3) Green Mint: A mixture of gardenia powder (yellow/blue) and copper phthalocyanine glycol

As shown in the above [Table 2], in the evaluation results of water resistance and curing time, in the case of the succinic acid cross-linked product (Example 2) using starch as a natural polysaccharide, it was found that it melted and flowed down as "dissolution" and the curing time was delayed, but the succinic acid cross-linked product (Example 1) using locust bean gum (LBG) as a natural polysaccharide was found to form a strong water-resistant film as "non-discoloring/water-resistant". In addition, it was found that the succinic acid cross-linked product (Example 1) using locust bean gum (LBG) as a natural polysaccharide can be effectively used even in strong winds because it is not blown away by strong winds. Meanwhile, the attached Figure 1 is a photograph showing the colored curing agent according to Example 1 being diluted in water and then sprayed on soil using a spraying device. And attached Fig. 2 shows a 500x magnification SEM photograph of PM10 particles before and after spraying (a) and a 3D-Optical Analyzer image (b).

Claims (7)

It is a colored hardener for suppressing dust that is sprayed on the object to be treated and forms a colored film.
A cross-linked polymer in which a hydrophilic polymer is cross-linked by a cross-linking agent;
Colorant;
surfactants; and
A colored hardener for suppressing dust, characterized in that it contains water.
In the first paragraph,
The above hydrophilic polymer includes polyvinyl alcohol (PVA) and natural polysaccharides,
The above cross-linking agent comprises succinic acid,
A colored curing agent for suppressing dust, characterized in that the cross-linked polymer comprises a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product in which polyvinyl alcohol (PVA) and a natural polysaccharide are cross-linked by succinic acid.
In the first paragraph,
The above hydrophilic polymer includes polyvinyl alcohol (PVA) and natural polysaccharides,
The above cross-linking agent comprises succinic acid,
The above cross-linked polymer includes a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product in which polyvinyl alcohol (PVA) and a natural polysaccharide are cross-linked by succinic acid,
The above natural polysaccharides include at least one selected from locust bean gum, gellan gum, carrageenan and agar,
The above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product is produced by cross-linking reaction of reactants including polyvinyl alcohol (PVA), natural polysaccharide and succinic acid in the presence of a reaction catalyst.
A colored curing agent for suppressing dust, characterized in that the reaction catalyst comprises sodium hypochlorite (NaOCl) and caustic potash (KOH).
In the first paragraph,
The above hydrophilic polymer includes polyvinyl alcohol (PVA) and natural polysaccharides,
The above cross-linking agent comprises succinic acid,
The above cross-linked polymer includes a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product in which polyvinyl alcohol (PVA) and a natural polysaccharide are cross-linked by succinic acid,
The above natural polysaccharides include at least one selected from locust bean gum, gellan gum, carrageenan and agar,
The above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product is produced by cross-linking reaction of reactants including polyvinyl alcohol (PVA), natural polysaccharide and succinic acid in the presence of a reaction catalyst.
The above reaction catalyst includes sodium hypochlorite (NaOCl) and caustic potash (KOH).
A colored curing agent for suppressing dust, characterized in that the above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product has a yield of 70% or more according to the following [mathematical formula].
[Mathematical formula]
Yield (%) = C/(A+B) x 100
(In the mathematical formula above,
A: The total weight of polyvinyl alcohol (PVA) and natural polysaccharide used in the reaction,
B: Weight of the cross-linking agent used in the reaction,
C: Weight of the crosslinked product produced by the reaction.)
In any one of the claims 2 to 4,
The above natural polysaccharide is locust bean gum,
A colored curing agent for suppressing dust, characterized in that the above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product comprises a compound represented by the following [chemical formula 1].
[Chemical Formula 1]

(In the chemical formula 1 above, n is an integer greater than or equal to 20.)
A method for manufacturing a colored hardener for suppressing dust that is sprayed on a treatment object to form a colored film,
A synthetic step of cross-linking reacting a reactant including polyvinyl alcohol, a natural polysaccharide, and succinic acid in the presence of a reaction catalyst to produce a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product in which the polyvinyl alcohol and the natural polysaccharide are cross-linked by succinic acid; and
Comprising a mixing step of mixing a coloring agent, a surfactant and water into the above succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product,
A method for producing a colored curing agent for suppressing dust, characterized in that in the above-mentioned synthesis step, sodium hypochlorite (NaOCl) and caustic potash (KOH) are used as the above-mentioned reaction catalysts.
In Article 6,
In the above synthesis step, sodium hypochlorite (NaOCl) and caustic potash (KOH) are mixed and used as the reaction catalyst at a weight ratio of 1:0.1 to 0.5, and the reactants are cross-linked under alkaline conditions of pH 9 to 11 and at a temperature of 80°C to 90°C for 3 to 5 hours to produce a succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product.
A method for producing a colored curing agent for suppressing dust, characterized in that the succinic acid cross-linked polyvinyl alcohol-polysaccharide cross-linked product produced through the above-mentioned synthetic step has a yield of 75% or more according to the following [mathematical formula].
[Mathematical formula]
Yield (%) = C/(A+B) x 100
(In the mathematical formula above,
A: The total weight of polyvinyl alcohol (PVA) and natural polysaccharide used in the reaction,
B: Weight of the cross-linking agent used in the reaction,
C: Weight of the crosslinked product produced by the reaction.)