KR101722544B1 - Manufacturing method for moisture absorbent and moisture absorbent manufactured by the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a moisture absorbent and a moisture absorbent manufactured by the method. A moisture absorbent is manufactured by using powdered active calcium oxide particles coated with fatty acid, thereby having excellent dehydration and moisture absorption effects and having excellent dispersibility as the moisture absorbent is coated with fatty acid.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a hygroscopic agent and a hygroscopic agent produced thereby,

The present invention relates to a method of producing a hygroscopic agent and a hygroscopic agent produced thereby, and more particularly, to a hygroscopic agent which is excellent in dehydration and hygroscopicity by using powdery active calcium oxide fine particles coated with a fatty acid, To a process for producing a desiccant having excellent dispersibility and a desiccant prepared thereby.

In general, a moisture absorbent is widely used to protect a product from moisture when packaging a product throughout the industrial field. Some typical moisture absorbers currently used include, for example, silica gel and chemicals (calcium chloride (CaCl ₂ ), sulfuric acid Magnesium oxide (MgSO ₄ ), magnesium chloride (MgCl ₂ ) and clay minerals (mica, diatomaceous earth, talc, quicklime, synthetic zeolite and natural zeolite) and oxides (magnesium oxide (MgO), iron oxide (Fe ₂ O ₃ ) (Al ₂ O ₃ ), silica), and a hygroscopic agent using an organic substance (triethylamine, methylcellulose, carboxymethylcellulose). These hygroscopic agents have the following disadvantages.

In other words, in the case of silica gel, sodium silicate is produced by decomposing into strong acid, so it is easy to handle, but its production cost is high, and it does not decompose naturally upon disposal after use. And the soil is acidified. Therefore, it is currently being avoided in advanced countries.

In addition, calcium chloride (CaCl ₂ ) is used in the product, which causes fatal corrosion problem after moisture absorption and damages metals and other products. Since some mineral products form powder powder, The moisture can be exuded to the outside, which is undesirable as a hygroscopic agent used in foods, medicines and precision parts.

In addition, since calcium chloride is excellent in moisture absorption ability, it is present as a hydrate such as calcium chloride monohydrate, dihydrate, tetra hydrate, hexahydrate, etc. in combination with moisture in the air, so that its use range is very limited for use as an absorbent, And when it is used in a metal product or an electronic product, there is a problem that the corrosion is progressed due to the rapid seizure.

In addition to the above-mentioned hygroscopic agents, natural diatomite and zeolite are prepared by impregnating calcium chloride (CaCl ₂ ) or magnesium chloride (MgCl ₂ ) solution, but chlorine ion (Cl ^- ) is generated from calcium chloride (CaCl ₂ ) or magnesium chloride (MgCl ₂ ) As a result, chlorine ion (Cl ^- ) reacts with metal components to generate rust, which is not suitable for packaging in foods, pharmaceuticals, and precision parts.

Korean Patent Publication No. 10-2005-0084702 (published on Aug. 29, 2005) Korean Patent Publication No. 10-2003-0024048 (published on Mar. 26, 2003)

The present invention relates to a method for producing a hygroscopic agent which is excellent in dehydration and hygroscopic effects and which is coated with a fatty acid and is excellent in dispersibility by producing a hygroscopic agent using powdery active calcium oxide fine particles coated with a fatty acid, .

In addition, when the present invention is used as an additive in a raw material mixture in the production of products such as rubber, plastic, and film, it is possible to completely remove water or air in the raw material mixture to produce a product free from bubbles, A method of producing a hygroscopic agent capable of improving the quality such as inhibition of foaming and reducing the defects, and a hygroscopic agent produced by the method.

The various problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

The method for preparing a hygroscopic agent according to the present invention comprises a raw material preparation step (S100) for preparing limestone, which is a natural mineral, as a raw material of a hygroscopic agent; A raw material firing step (S200) for preparing quick lime by removing contaminants adsorbed on fine pores of the coarse-ground limestone by heating the coarse-ground limestone using a firing furnace after the prepared limestone is crushed and activated, thereby activating the quick lime; (S300) diluting purified liquor mixed with the quicklime to dilute the lime and causing water to be absorbed and penetrated into the surface of the quicklime to form a slaked lime; A dehydration and drying step (S400) of removing water from the slaked lime which is infiltrated with the purified water; (S500) of heating the dried slaked lime using a baking furnace to remove water remaining in the dried fine slaked lime and activating the activated slaked lime to produce activated calcium oxide (S500); A pulverizing step (S600) of finely pulverizing the calcined active calcium oxide to produce activated calcium oxide fine particles; And a surface coating step (S700) of coating the surface of the active calcium oxide fine particles with a fatty acid to prepare a moisture absorbent.

The raw material firing step (S200) may be performed by charging the coarse-ground limestone into a firing furnace and then heating at a temperature of 1100 to 1300 ° C for 2 to 10 hours.

The dewatering and drying step (S400) further comprises dewatering the slaked lime which has been infiltrated with the purified water using a filter, drying the dewatered slaked lime at a temperature of 30 to 50 ° C, and the calcining step (S500) Followed by charging the limestone into the calcining furnace and then heating at a temperature of 750 to 850 캜 for 2 to 10 hours.

In the pulverizing step (S600), active calcined calcium oxide fine particles can be prepared by pulverizing the calcined active calcium oxide to a particle size of 2.5 to 3.5 mu m.

In the surface coating step (S700), the fatty acid is mixed in an amount of 0.1 to 0.2 parts by weight based on 100 parts by weight of the active calcium oxide fine particles, and the fatty acid is selected from the group consisting of myristic acid, palmitic acid, stearic acid and arachidic acid One or more saturated fatty acids may be used.

The moisture absorbent may contain 93% by weight of active calcium oxide (CaO) and 0.2% by weight of a fatty acid.

The present invention also includes a hygroscopic agent produced by the above-mentioned production method.

The details of other embodiments are included in the detailed description.

The method for producing a hygroscopic agent according to the present invention is excellent in dehydration and hygroscopic effects by producing a hygroscopic agent using powdery active calcium oxide fine particles coated with a fatty acid, and is coated with a fatty acid and is excellent in dispersibility.

In addition, when the hygroscopic agent according to the present invention is mixed with an additive of a raw material mixture in the production of products such as rubber, plastic or film, moisture and air in the raw material mixture can be completely removed to produce a product free from bubbles, It is possible to obtain the effect of improving quality such as dimensional stability and foaming suppression and reducing defects.

It will be appreciated that embodiments of the technical idea of the present invention can provide various effects not specifically mentioned.

1 is a flow chart for explaining a method for producing a moisture absorber according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be construed as ideal or overly formal in meaning unless explicitly defined in the present application Do not.

Hereinafter, a method for producing a moisture absorbent according to the present invention will be described in detail with reference to the accompanying drawings.

The method for producing a hygroscopic agent according to the present invention is characterized in that when a hygroscopic agent is prepared by using powdery active calcium oxide fine particles coated with a fatty acid and is mixed with an additive of a raw material mixture in the production of a product such as rubber or plastic, It is possible to produce a product free from air bubbles by completely removing moisture and air, and it is possible to obtain an effect of quality improvement such as dimensional stability of a product, inhibition of foaming and reduction of defects.

1 is a flow chart for explaining a method for producing a moisture absorber according to the present invention.

1, a method of manufacturing a desiccant according to the present invention includes a raw material preparation step S100, a raw material firing step S200, a purified water dilution step S300, a dewatering and drying step S400, a firing step S500, A grinding step (S600) and a surface coating step (S700).

1. Raw material preparing step (S100)

The raw material preparation step (S100) is a step of preparing a raw material for producing a hygroscopic agent. In the present invention, limestone, which is a natural mineral, can be used as a raw material of the hygroscopic agent.

The limestone is a type of aqueous rock containing calcium carbonate (CaCO ₃ ) as a main component. The limestone can be produced by chemical precipitation in seawater, fossil of living organisms with calcareous shell, etc. In the present invention, The manufacturing cost of the product can be reduced.

2. Raw material firing step (S200)

In the step S200, the prepared limestone is pulverized and then the pulverized limestone is heated using a calcining furnace to remove pollutants adsorbed on the fine pores of the pulverized limestone to activate activated lime .

The raw material firing step (S200) may be performed by charging the pulverized limestone into a firing furnace and then heating at a temperature of 1100 to 1300 ° C for 2 to 10 hours, and the reaction may proceed as follows.

Calcium carbonate (CaCO ₃ ) → calcium oxide (CaO) + carbon dioxide (CO ₂ )

In the step S200, the limestone may be pulverized before being heated using a firing furnace. The pulverization of the limestone may be carried out by using a granulator. The granulator may be a granulator a known granulator such as a granulator, a drum granulator or a compressible pelletizer may be used.

3. Purified water dilution step (S300)

In the purifying water diluting step (S300), purified water is mixed with the quicklime to dilute the liquid, and water is absorbed and infiltrated into the surface of the quicklime and the fine pores to produce slaked lime.

In the purifying water dilution step (S300), the quicklime may react with the purified water to produce a lime slurry, wherein the reaction may proceed as follows.

Calcium oxide (CaO) + purified water (H ₂ O), calcium hydroxide (Ca (OH) ₂ )

4. Dehydration and drying step (S400)

The dewatering and drying step (S400) is a step of removing moisture from the slaked lime which is absorbed and infiltrated by the purified water.

In the dewatering and drying step (S400), the dehydrated lime can be dried at a temperature of 30 to 50 ° C after the dehydrated lime is dewatered using a filter or the like.

5. Firing step (S500)

In the firing step (S500), the dried slaked lime is heated using a firing furnace to remove moisture remaining in the dried fine slaked lime and activate the activated calcium oxide.

The firing step (S500) may be performed by charging the dried limestone into a firing furnace, and then heating the firing furnace at a temperature of 750 to 850 ° C for 2 to 10 hours, and the reaction may proceed as follows.

Ca (OH) ₂

① Firing (750 to 850 ° C) → CaO + H ₂ O

② + CO ₂ → CaCO ₃ → calcination → CaO

③ + Na ₂ CO ₃ → CaCO ₃ → calcination → CaO

④ + 2NH ₄ Cl → CaCl ₂ + 2NH ₄ OH

CaCl ₂ + Na ₂ CO ₃ → CaCO ₃ → calcination → CaO

6. Grinding step (S600)

The pulverizing step (S600) is a step of finely pulverizing the calcined activated calcium oxide to produce activated calcium oxide fine particles.

In the pulverizing step (S600), active calcium oxide fine particles can be prepared by pulverizing the calcined active calcium oxide to a particle size of 2.5 to 3.5 mu m.

When the active calcium oxide is pulverized to less than 2.5 占 퐉 in the pulverizing step (S600), the size of the particles is too small, resulting in difficulty in workability and generation of dust, and pulverization in excess of 3.5 占 퐉 There is a problem that the particle size is too large and the dispersibility is poor.

Meanwhile, in the method for producing a hygroscopic agent according to the present invention, the wet process for producing activated calcium oxide (CaO) by diluting the calcium oxide produced in the raw material firing step with purified water, followed by dehydration, drying and firing steps has been described. May be pulverized with a particle diameter of 2.5 to 3.5 탆 to prepare active calcium oxide.

7. Surface coating step (S700)

The surface coating step (S700) is a step of coating a surface of the active calcium oxide fine particles with a fatty acid to prepare a moisture absorbent.

In the surface coating step (S700), active calcium oxide fine particles coated with fatty acid can be prepared by mixing active calcium oxide fine particles pulverized with a particle size of 2.5 to 3.5 탆 with a fatty acid, wherein the fatty acid comprises 100 parts by weight of active calcium oxide fine particles 0.1 to 0.2 parts by weight of the fatty acid is mixed with the fatty acid, and as the fatty acid, any one or more saturated fatty acids selected from the group consisting of myristic acid, palmitic acid, stearic acid and arachidic acid may be used.

When the fatty acid is contained in an amount of less than 0.1 part by weight in the surface coating step (S700), it may not be uniformly dispersed when it is mixed with an additive of a raw material mixture in the production of a product such as rubber or plastic, There is a possibility that the increase in the dispersion effect is insignificant and the dehydration and hygroscopic effects are inferior.

Further, the present invention can produce a desiccant having excellent dehydration and hygroscopic effects and being coated with a fatty acid and having excellent dispersibility by treating the active calcium oxide fine particles in powder form with a fatty acid as described above.

Hereinafter, the method for producing a film using the absorbent manufactured according to the present invention will be described in more detail with reference to Examples and Comparative Examples.

First, 100 parts by weight of a polyolefin resin, 15 parts by weight of magnesium stearate, 5 parts by weight of a dispersant, 6 parts by weight of a filler, 8 parts by weight of a release agent and 3 parts by weight of a moisture absorbent were added to a mixer.

Here, the polyolefin-based resin is a polymer polymerized from a monomer having an unsaturated double bond, and the polyolefin-based resin is at least one selected from the group consisting of high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, Block copolymers and random copolymers, ethylene-propylene copolymers, ethylene-butylene copolymers, ethylene-octene copolymers, ethylene-vinyl acetate (EVA) copolymers, ethylene-ethyl acrylate copolymers, ethylene -Methyl acrylate copolymer, and a mixture containing two or more of them. Examples of the alpha olefin block copolymer or random copolymer having 3 to 15 carbon atoms include copolymers of ethylene and 1-octene, copolymers of ethylene and 1-butene In the examples according to the present invention, medium density Li was used as the ethylene resin.

The magnesium stearate may be a special basic fatty acid magnesium salt in order to improve the compatibility with the master batch and the ability to form a monomolecular film, and the magnesium stearate may be 12-hydroxymagnesium stearate. The magnesium stearate improves the compatibility of the polyolefin resin with other additives in the extruder and acts as a lubricant such as a metal soap to impart lubricity between the metal surface and the polymer to improve the flowability of the resin in the extruder screw .

The dispersing agent plays a role of increasing the moldability and the dischargeability of the master batch pellets. As the dispersing agent, a known dispersing agent may be used within the range of improving the workability. For example, zinc stearate or calcium Stearate may be used.

The filler may be at least one selected from the group consisting of titanium oxide, barium sulfate, barium titanate, calcium carbonate, silica, talc, clay and mica powder. In the embodiment of the present invention, silica may be used .

The release agent may be a wax, and the wax may be a natural wax or a synthetic wax. In the examples according to the present invention, a synthetic wax such as a polyethylene wax or a polypropylene wax may be used.

The hygroscopic agent may be a hygroscopic agent prepared by the method as described above. The hygroscopic agent may be mixed with an additive of a raw material mixture such as a dispersant, a filler, a release agent, etc., It is possible to obtain a bubble-free film, and it is possible to obtain an effect of improving quality such as dimensional stability of a product, suppressing foaming, and reducing defects.

Next, the mixture charged into the mixer was stirred at 360 rpm for 10 minutes and then stirred at 200 rpm for 5 minutes. At this time, the stirring temperature was set at 35 캜.

Then, the agitated mixture was put into a plastic extruder, melt extruded at 180 ° C., cooled at room temperature, and then pelletized with an average diameter of 5 mm to prepare a master batch.

Subsequently, 2 g of the master batch and 100 g of LDPE resin (LG Chem) were blended, and then a film was produced in a blown-in-line manner using a film extruder.

<Comparative Example>

A film was prepared using the same composition as in the above Example, except that the film was prepared without mixing the moisture absorber in the Comparative Example.

1. Analysis of the components of the desiccant

The components of the hygroscopic agent produced by the above-mentioned production method were analyzed and the results of the analysis are shown in Table 1 below.

Item Content (wt%) Remarks Active calcium oxide (CaO) 93 wt% chief ingredient Magnesium oxide (MgO) 2.0 wt% or less Impurities of limestone Hydrochloric acid insoluble matter (silica (SiO ₂ )), iron powder, alumina (Al ₂ O ₃ ) 1.0 wt% or less Impurities of limestone Calcium carbonate (CaCO ₃₎ 1.0 wt% or less Unconsolidated limestone component Calcium hydroxide (Ca (OH) ₂ ) 1.0 wt% or less Reactant with water during processing fatty acid 0.2 wt% Powder coating agent

Referring to Table 1, as described above, the hygroscopic agent prepared by the method of the present invention has 93% by weight of active calcium oxide (CaO) and 0.2% by weight of fatty acid.

2. Experiment of the properties of the desiccant

The properties of the hygroscopic agent containing the above components were tested, and the results are shown in Table 2 below.

division Absorbent Test Methods Active calcium oxide (% by weight) 93 wt% EDTA × NN indicator Absorption Rate (%) 25.0 or higher 1: 5-H2O reaction
115 ℃ 3 hr constant drying Loss on ignition (%) 4.0 or less 1050 占 50 占 폚 占 2 hr Particle Size (㎛) 3.0 탆 Laser particle size analysis

The absorption rate (%) of the hygroscopic agent prepared according to the present invention is 25.0% or more when the 1: 5-H2O reaction is conducted at 115 ° C for 3 hours and the weight loss is 1050 ± 50 ° C × 2 hr.

3. Bubble and film badness

Films prepared according to the above Examples and Comparative Examples were prepared and tested for the presence or absence of defects of the films.

The presence or absence of defects was determined based on whether or not air bubbles were formed on the surface or inside of the film, and a total of 10 times was performed by the method according to the Examples and Comparative Examples to produce a film.

division Example Comparative Example Bubble generation × ○ (occurs once)

Referring to Table 3, defects such as bubbles were not generated in the films prepared according to the examples, whereas defects were produced in the films produced according to the comparative examples 10 times in total during the production of the film. Respectively.

This is because, when the film is produced according to the embodiment, the moisture absorber is mixed with the additive of the raw material mixture to completely remove water or air in the raw material mixture, thereby solving the bubble defect problem. As a result, It is possible to obtain the effect of improving the quality and reducing the defects.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that one embodiment described above is illustrative in all aspects and not restrictive.

Claims (7)

A raw material preparation step (S100) for preparing limestone, which is a natural mineral, as a raw material of the moisture absorbent;
A raw material firing step (S200) for preparing quick lime by removing contaminants adsorbed on the micropores of the coarse-ground limestone by heating the coarse-ground limestone by using a firing furnace after the prepared limestone is crushed and activated;
(S300) diluting purified liquor mixed with the quicklime to dilute the lime and causing water to be absorbed and penetrated into the surface of the quicklime to form a slaked lime;
A dehydration and drying step (S400) of removing water from the slaked lime which is infiltrated with the purified water;
(S500) of heating the dried slaked lime using a baking furnace to remove water remaining in the dried fine slaked lime and activating the activated slaked lime to produce activated calcium oxide (S500);
A pulverizing step (S600) of finely pulverizing the calcined active calcium oxide to produce activated calcium oxide fine particles; And
And a surface coating step (S700) of coating the surface of the active calcium oxide fine particles with a fatty acid to prepare a moisture absorbent.
The method according to claim 1,
Wherein the raw material firing step (S200) is performed by charging the coarse-ground limestone into a firing furnace and then heating at a temperature of 1100 to 1300 ° C for 2 to 10 hours.
3. The method of claim 2,
In the dehydration and drying step (S400), the dehydrated lime is dried at a temperature of 30 to 50 DEG C after dewatering the lime by absorption of the purified water through the filter,
Wherein the calcining step (S500) is performed by charging the dried limestone into a calcining furnace, and then heating the calcined limestone at a temperature of 750 to 850 ° C for 2 to 10 hours.
The method of claim 3,
Wherein the pulverizing step (S600) comprises pulverizing the calcined active calcium oxide to a particle size of 2.5 to 3.5 占 퐉 to produce activated calcium oxide fine particles.
5. The method of claim 4,
In the surface coating step (S700), the fatty acid is mixed in an amount of 0.1 to 0.2 parts by weight based on 100 parts by weight of the active calcium oxide fine particles, and the fatty acid is selected from the group consisting of myristic acid, palmitic acid, stearic acid and arachidic acid Characterized in that at least one saturated fatty acid is used.
6. The method of claim 5,
Wherein the moisture absorbent contains 93% by weight of active calcium oxide (CaO) and 0.2% by weight of fatty acid. delete

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