KR101796067B1

KR101796067B1 - Manufacturing method for packing box using expanded polystyrene beads and packing box manufactured by the same

Info

Publication number: KR101796067B1
Application number: KR1020150160782A
Authority: KR
Inventors: 박정환
Original assignee: 주식회사 세광이피에스
Priority date: 2015-11-17
Filing date: 2015-11-17
Publication date: 2017-11-14
Also published as: KR20170057537A

Abstract

The present invention relates to a method for producing a packing styrofoam using expanded polystyrene particles and a packing styrofoam produced by the method.
The method for producing packing foamed polystyrene particles using the expanded polystyrene particles according to the present invention comprises the steps of preparing foamed polystyrene particles (S100), preparing a foamed polystyrene particle mixture (S200), mixing a solvent and a binder (S300), stirring (S400) Step S500.
According to the present invention, the granulated expanded polystyrene particles and various additives are mixed and molded to reduce the manufacturing cost, cure in a short time without cracking and shrinkage, excellent heat insulation performance, It is possible to secure mechanical and physicochemical strength, to prevent fire propagation due to toxic gas, to minimize cracking and shrinkage, and to reduce environmental pollution.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a foamed polystyrene foam,

The present invention relates to a method for producing packing foamed polystyrene particles and a packaging foamed styrofoam produced by the method, and more particularly, to a method for producing packing foamed polystyrene particles by mixing and granulating the expanded polystyrene particles with various additives, The present invention relates to a method for producing a styrofoam for packaging using expanded polystyrene particles which can be cured within a short time without shrinkage and which can secure mechanical and physical strength required for the styrofoam.

Expanded polystyrene is a foamed product prepared by adding a foaming agent such as pentane (C ₅ H ₁₂ ) or butane (C ₄ H ₁₀ ) to a polystyrene resin prepared by polymerizing a styrene monomer or a copolymer resin thereof It is made of expanded resin by generating bubbles by heating polystyrene resin (expandable polystyrene), and is widely used for packaging materials and building materials because it is white and light, and is excellent in water resistance, heat insulating property, sound absorbing property and buffering property.

As for the molding process of such expanded polystyrene products, a polystyrene or styrene copolymer resin containing a small bead having a diameter of 0.2 to 0.3 mm or a blowing agent supplied in the form of a pellet having a length of about 2.5 mm is foamed The beads are aged and dried, and the aged expanded particles are placed in a mold and heated in a high-temperature, high-pressure steam to be formed into a desired shape.

The foamed polystyrene thus produced has 98% of the total volume of air, only about 2% of the resin, occupies about 2% of the total volume, and has a unique foam structure in which the air is sealed in the foam of plastic. Therefore, excellent foamability, heat insulation, sound absorption, And it has various usability.

In general, foamed molded articles of expanded polystyrene have high strength, light weight, cushioning property, waterproof property, heat insulation property and heat insulation property, and thus they are used as packaging boxes for household appliances, packing boxes for agricultural and marine products, and insulation materials for housing construction. Among them, foamed polystyrene is used as insulation material for housing construction because more than 70% of domestic demand is due to light weight, warmth, and insulation. Demand is also increasing in packaging boxes for home appliances and packing boxes for agricultural and marine products.

For example, expanded polystyrene used as a packing box for agricultural and marine products can be used to freshly distribute various items such as fish and shellfish, meat, and agricultural products, which are liable to be deteriorated due to heat insulation, light weight, The foamed polystyrene used as a packaging box for household appliances can be safely packaged and transported without being damaged by an external impact due to high strength, light weight and buffering property.

However, such expanded polystyrene is very vulnerable to heat and melts at an early stage in the event of a fire, and not only serves as a medium to propagate the fire, but also has a problem of serious injury due to the toxic gas generated in the combustion. In order to be safely used as a packing box of a foamed polystyrene, flame retardation of the expanded polystyrene is necessarily required and deterioration of mechanical properties should be minimized.

Conventionally, various methods have been proposed for improving the flame retardancy of styrofoam, thereby delaying the ignition time and slowing the propagation of the flame. Mainly used methods of smearing polymers include the production of heat-resistant polymers (CPE, PVC, etc.) by changing the molecular structure, the method of chemically bonding the flame retardant components in the plastic structure (reactive flame retardants), the addition of the flame- A method (addition type flame retardant), a method of coating or painting a flame retardant, or a method of improving the heat resistance by changing the design of a product, and a general flame retardant is added to general flame retardant.

For example, Korean Patent Registration No. 305,711 discloses a flame retardant styrofoam heat insulation material produced by coating a surface of expanded polystyrene particles with a flame retardant such as a halide, phosphorus oxide and the like, followed by foam molding. Korean Utility Model Registration No. 20-241745 Discloses a flame retardant styrofoam heat insulation material on both sides of a styrofoam plate with an adhesive made of a non-burnable material having a three-layer structure of aluminum sheet, fabric, and vinyl chloride. Korean Patent Publication No. 2001-0072979 discloses a flame retardant comprising a brominated organic compound Is disclosed.

However, these conventional flame retardant styrofoams are not only economical, but also contain halogen, so that they can not cope with environmental regulations properly, and the manufacturing method is complicated and the flame retardant effect is not sufficient. In addition, the conventional flame retardant polymer foam composition has a certain degree of flame retardancy, but since the content of the composition is high or the composition itself deteriorates the mechanical properties of the foam, it is difficult to obtain a structural product such as a packaging box for home appliances or a packaging box for agricultural products Which is difficult to use.

Domestic Registration Practice No. 20-0304380 (registered on February 03, 2003) Korean Patent Publication No. 10-2006-0125300 (published on December 06, 2006)

The present invention relates to a method for manufacturing a foamed polystyrene foam which is capable of reducing the manufacturing cost by mixing the pulverized expanded polystyrene particles with various additives and curing in a short time without cracking and shrinkage, And to provide a packaging styrofoam produced by the method.

The present invention also relates to a method for manufacturing a foamed polystyrene foam which can secure mechanical and physicochemical strength even when contacted with a flame, can prevent fire propagation due to toxic gas, minimizes cracking and shrinkage phenomena, A method for producing the styrofoam for packaging, and a styrofoam for packaging manufactured 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 producing a foamed polystyrene foam using expanded polystyrene particles according to the present invention comprises: a step (S100) of preparing foamed polystyrene particles by pulverizing styrofoam produced using expanded polystyrene to make expanded polystyrene particles having a uniform particle size; (S200) of preparing a foamed polystyrene particle mixture by mixing the expanded polystyrene particles with a silicate, an aluminum silicate and a heat insulating powder to be mixed to prepare a foamed polystyrene particle mixture; A solvent and a binder mixing step (S300) for mixing and dissolving a solvent and a binder in the mixture; (S400) in which the solvent and the binder are mixed using a stirrer to uniformly disperse and mix the mixture of the expanded polystyrene particles, the silicate, the aluminum silicate, and the heat insulating powder; And a forming step (S500) of putting the agitated mixture into a mold having a predetermined shape to produce a packing styrofoam.

As the styrofoam produced by using the expanded polystyrene in the expanded polystyrene particle producing step (S100), expanded styrofoam spherical particles, processed molded panels or foamed polystyrene styrofoam discarded during molding are used, milled using a cutting mill equipped with a knife bar, and pulverized in a particle size of 300 to 800 mu m in an irregular shape whose size and shape are not constant.

In the silicate, the aluminum silicate and the heat insulating powder used in the foamed polystyrene particle mixture preparation step (S200), any one of sodium silicate, potassium silicate or lithium silicate is used as the silicate, and the silicate is the expanded polystyrene particle 100 And the aluminum silicate is contained in an amount of 3 to 8 parts by weight based on 100 parts by weight of the expanded polystyrene particles and the heat insulating powder is selected from the group consisting of diatomaceous earth, expanded vermiculite, zeolite, bentonite, perlite, And 0.5 to 5 parts by weight based on 100 parts by weight of the expanded polystyrene particles.

The modified limonene solvent is selected from the group consisting of hydroxyapatite, activated alumina, zeolite, clay and diatomaceous earth with respect to 100 parts by weight of the limonene solvent in the solvent and binder mixing step (S300) And 5 to 15 parts by weight of at least one compound is used. The binder is a magnesium phosphate-based inorganic binder, and the magnesium phosphate-based inorganic binder includes a magnesium-based metal oxide, a phosphate and a silica compound, Wherein the magnesium phosphate-based inorganic binder contains the expanded polystyrene particles, the silicate, the aluminum silicate, and the heat insulating powder in an amount of 80 to 100 parts by weight based on 100 parts by weight of the mixture of the expanded polystyrene particles, the silicate, the aluminum silicate, mix Mixture for a total of 100 parts by weight may be included between 10 and 15 parts by weight.

The solvent and binder mixing step (S300) further comprises a flame retardant adjuvant, wherein the flame retardant aid is contained in an amount of 2 to 5 parts by weight based on 100 parts by weight of the mixture of the expanded polystyrene particles, the silicate, the aluminum silicate and the heat insulating powder (Sb ₂ O ₃ , Sb ₂ O ₅ ), magnesium hydroxide, zinc borate, zinc sulfate, ammonium polyphosphate, and the like, the average particle size of the flame-retardant aid particles is 150 to 250 mesh. , Phosphorus flame retardant, phosphates, and yellow loess can be used.

The stirring step (S400) may be carried out at a stirring speed of 500 to 1000 rpm at a temperature of 50 to 65 DEG C for 1 to 2 hours.

In addition, the present invention includes a packaging styrofoam using expanded polystyrene particles produced by the above-described production method.

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

The manufacturing method of the packing foamed polystyrene particles using the expanded polystyrene particles according to the present invention can reduce the manufacturing cost by mixing the pulverized expanded polystyrene particles with various additives and can cure in a short time without cracking and shrinkage, It is safe for flames.

Styrofoam for packaging manufactured by using the expanded polystyrene particles according to the present invention can secure mechanical and physicochemical strength even when contacted with a flame, can prevent fire propagation due to toxic gas, minimizes cracking and shrinkage And can reduce environmental pollution.

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

FIG. 1 is a flow chart for explaining a method for producing a packaging styrofoam using expanded polystyrene particles according to the present invention.

Advantages and features of the present invention, and methods of accomplishing the same, will be apparent from and elucidated with reference to the embodiments described hereinafter in detail. 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.

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.

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 foamed styrofoam using expanded polystyrene particles according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, the method for producing packing foamed polystyrene particles using foamed polystyrene particles according to the present invention includes steps of preparing expanded polystyrene particles (S100), preparing expanded polystyrene particle mixture (S200), mixing solvent and binder (S300) Step S400 and forming step S500.

1. Expanded polystyrene particle production step (S100)

The foamed polystyrene particles are prepared by pulverizing the foamed polystyrene foamed with the foamed polystyrene to produce foamed polystyrene particles having a uniform particle size.

As the styrofoam produced by using the expanded polystyrene in the present invention, expanded styrofoam spherical particles, processed molded panels or foamed polystyrene styrofoam discarded during molding may be used.

Also, in the expanded polystyrene particle production step (S100), the milling of the styrofoam is carried out by using a cutting mill with a knife bar, By weight.

2. Manufacturing step of foamed polystyrene particle mixture (S200)

The foamed polystyrene particle mixture preparation step (S200) is a step of mixing the foamed polystyrene particles with a functional additive capable of improving physical properties to prepare a mixture.

As the additive in the present invention, silicate, aluminum silicate and heat insulating powder may be used.

The silicate may be any one selected from the group consisting of sodium silicate, potassium silicate, and lithium silicate. Alkali metals such as sodium and potassium in the silicate promote curing even at a relatively low temperature and directly participate in the reaction and improve the strength.

In addition, when heat of 100 ° C or more is received, the water contained therein evaporates and evaporates as it evaporates, which can constitute an inorganic foam, thereby increasing the adiabatic effect.

In the present invention, the silicate may be included in an amount of 5 to 15 parts by weight based on 100 parts by weight of the expanded polystyrene particles. If the silicate is contained in an amount of less than 5 parts by weight, the above effect can not be expected. So that they can not be effectively used.

The aluminum silicate is a fine hollow powder and has excellent heat radiation and thermal resistance. It has a melting point of about 1,800 ° C and a compressive strength of about 3,000 N / cm ^2, so it has excellent durability and can exhibit semi-permanent insulation . In the present invention, the aluminum silicate may be included in an amount of 3 to 8 parts by weight based on 100 parts by weight of the expanded polystyrene particles.

The heat insulating powder may be a powder made of a porous material capable of providing a heat insulating effect by blocking heat conduction or heat transfer. For example, the heat insulating powder may be at least one selected from diatomaceous earth, expanded vermiculite, zeolite, bentonite, perlite, and airgel, and the heat insulating powder may be included in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the expanded polystyrene particles.

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If the heat insulating powder is contained in an amount of less than 0.5 parts by weight, the heat insulating effect can not be obtained. If the heat insulating powder is contained in an amount exceeding 5 parts by weight, the problem of dust and strength may be deteriorated.

3. Solvent and binder mixing step (S300)

The solvent and binder mixing step (S300) is a step of mixing and dissolving a solvent and a binder in a mixture of the expanded polystyrene particles, silicate, aluminum silicate and heat insulating powder.

In the present invention, a modified limonene solvent is used in consideration of the solubility, dissolution efficiency and environmental aspects of the expanded polystyrene particles. The modified limonene solvent is selected from the group consisting of hydroxyapatite, activated alumina, zeolite, 5 to 15 parts by weight of at least one compound selected from the group consisting of clay and diatomaceous earth are preferably added.

Compounds used as a modifier of the limonene solvent serve to reduce the peculiar smell of limonene, and it is more preferable to use hydroxyapatite as the modifier. The hydroxyapatite (HAP) is a calcium phosphate type compound which is used as an antibacterial agent, an odor adsorbent, a polymer suspending agent, etc., and not only plays a role of stabilizing the expanded polystyrene in a sol state but also reduces the interfacial tension of the solvent, Can be dispersed stably in small amounts, and adsorbed on the monomer surface to prevent agglomeration.

The binder may be a magnesium phosphate-based inorganic binder that acts as a binder of the expanded polystyrene particles. The magnesium phosphate-based inorganic binder constitutes a stable magnesium phosphate-based fire retardant at a high temperature, and suppresses expansion due to thermal changes during use So that cracks can be prevented from occurring.

The magnesium phosphate-based inorganic binder may include a magnesium-based metal oxide, a phosphate, and a silica compound. The magnesium phosphate-based, magnesium-based metal oxide is a magnesium phosphate octahydrate, magnesium (MgO), minor magnesia (Dead Burned Magnesia), gyeongso magnesia (Light Burned Magnesia), jeonyung magnesia, aluminum carbonate, magnesium oxide in the inorganic binder (MgCO ₃ ), Or a mixture thereof. In the magnesium phosphate-based inorganic binder, the phosphate is selected from the group consisting of potassium phosphate monobasic, potassium phosphate dibasic, potassium phosphate dibasic, sodium phosphate dibasic, sodium phosphate dibasic, sodium phosphate dibasic, calcium phosphate monobasic, Magnesium phosphate monobasic, magnesium phosphate monobasic, magnesium aluminum phosphate, aluminum phosphate, or a mixture thereof. In the magnesium phosphate-based inorganic binder, the silica compound may be any one of wollastonite, folklite cement, alumina cement, fly ash cement and blast furnace cement, or a mixture thereof.

In the present invention, the modified limonene solvent contains 80 to 100 parts by weight of the modified phosphate-based inorganic binder based on 100 parts by weight of the mixture of the expanded polystyrene particles, the silicate, the aluminum silicate and the heat insulating powder, 10 to 15 parts by weight of the modified limonene solvent and magnesium phosphate based inorganic binder may be included in 100 parts by weight of the mixture of the silicate, the aluminum silicate and the heat insulating powder. When the modified limonene solvent and the magnesium phosphate based inorganic binder are included in the above range, It is difficult to expect a desired adiabatic effect.

In the present invention, the flame-retarding auxiliary may be added to 100 parts by weight of the mixture of the foamed polystyrene particles, the silicate, the aluminum silicate and the heat insulating powder in the step of mixing the solvent and the binder (S300) 2 to 5 parts by weight may be included.

The flame-retardant adjuvant may further include inorganic, nitrogen-based, and phosphorus-based flame retardants, completely eliminating the halogen system in view of human hazards. For example, the flame retardant aid is antimony oxide _{(Sb 2 O 3, Sb 2} O 5), the group consisting of magnesium hydroxide, boric acid, zinc sulfate, zinc ammonium polyphosphate (ammonium polyphosphate), phosphorus-based flame retardant, phosphate acids and loess May be used.

The average particle size of the flame-retardant aid particles is preferably 150 to 250 mesh. If the particle size is out of the above range, the blending and dispersing property with the expanded polystyrene particles is not good and the flame retardancy efficiency may not be satisfied.

Further, the use of the flame-retardant adjuvant as described above can minimize the toxic gas and smoke density considering the deterioration of the physical properties and the human body hazard, thereby securing the stability and environment-friendliness and exhibiting the effect of improving the flame retardancy .

4. Stirring step (S400)

In the stirring step (S400), the solvent and the binder are mixed using a stirrer to uniformly disperse and mix the mixture of the expanded polystyrene particles, the silicate, the aluminum silicate, and the heat insulating powder.

The stirring step (S400) may be carried out at a stirring speed of 500 to 1000 rpm at a temperature of 50 to 65 ° C for 1 to 2 hours. When the stirring step is stirred outside the temperature range described above, complete mixing is performed Gel phenomenon may occur before it is undesirable.

In addition, when the stirring step (S400) is stirred at a stirring speed exceeding 1000 rpm, there is a tendency of entanglement and dispersion of the dispersion is not performed well, and when the stirring is performed at a stirring speed of less than 500 rpm, .

5. Molding step (S500)

The forming step S500 is a step of preparing the packing styrofoam by using the agitated mixture. The packing styrofoam is prepared by putting the agitated mixture into a mold having a predetermined shape, molding it into a desired size, thickness and shape, .

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, with reference to the accompanying drawings, a method for producing a foamed styrofoam using expanded polystyrene particles according to the present invention will be described in more detail.

First, foamed polystyrene foam foamed to be discarded during molding was prepared and then pulverized into particles having a particle size of 300 to 800 탆 using a cutting mill to prepare expandable polystyrene particles.

Next, 10 parts by weight of sodium silicate, 5 parts by weight of aluminum silicate, and 2 parts by weight of bentonite were added to 100 parts by weight of the expanded polystyrene particles by mixing sodium silicate, aluminum silicate and bentonite with the expanded polystyrene particles. .

Subsequently, 90 parts by weight of the modified limonene solvent and 12 parts by weight of the magnesium phosphate type inorganic binder were mixed with 100 parts by weight of the mixture, and then 3 parts by weight of antimony oxide (Sb ₂ O ₃ , Sb ₂ O ₅ ) And the mixture was stirred at a temperature of 55 DEG C at a stirring speed of 800 rpm for 1 hour and 30 minutes.

Then, after the above stirring, the mixture was put into a mold of an electrical appliance package box, molded, and then cured to produce a styrofoam for packaging electrical appliances.

Styrofoam for packaging of household electrical appliances was prepared by using foamed polystyrene styrofoam to be discarded during molding and used as packaging styrofoam according to a comparative example. Styrofoam for packaging of household appliances according to the comparative example was not mixed with various additives.

The bending strength, water resistance, formability and weldability of the packaging styrofoam prepared according to the above Examples and Comparative Examples were evaluated, and the results are shown in Table 1.

Among these items, the bending strength was tested with the bending strength measuring device specified in KS M 3808. The test standard is based on 15 / cm ³ or more as specified in Insulating Board No. 4, Respectively.

The water resistance was determined by measuring the strength with a bending strength meter after placing a part of the sample collected from each foamed molding in a constant temperature water bath set at 50 DEG C for 1 hour and judging based on the same criteria as the bending strength. Were judged by numerical change and visual observation.

After the foamed molded article was cut, the meltability was evaluated in a comprehensive manner by combining the visibility of the surface smoothness with the measured values of bending strength. In this test, the gap between the foamed particles and the smoothness of the foamed particles were checked by the naked eye, and the result was 80% Were evaluated as defective.

division Form of mold Bending strength Water resistance Formability Weldability Example Good shape stability Great Great Great Great Comparative Example Surface shrinkage occurred Bad Bad Bad Bad

Referring to Table 1, the foamed polystyrene foamed styrofoam used for molding was mixed with various additives to produce the foamed styrofoam, and the surface shrinkage phenomenon did not occur, so that the foam was good in terms of shape stability and had excellent bending strength, And excellent in weldability.

Table 2 shows the results of density, initial thermal conductivity, flexural fracture load, compressive strength, water absorption, and flammability of the foamed styrofoam prepared according to the above examples, using the KSM 3808- Respectively.

Referring to the following Table 2, it can be seen that the packing styrofoam prepared according to the Examples is excellent in physical properties such as density, initial thermal conductivity, flexural fracture load, compressive strength, water absorption and combustibility.

Conformance standard Example KSM 3808-Bead Method 2 Species Test Items Density (kg / m ³ ) 25 or more 26.7 Initial thermal conductivity (w / m · k) 0.032 or less 0.26 Flexural failure load (N) 30 or more 35 Compressive strength (N / cm ² ) 12 or more 16 Absorption rate (g / 100 cm ² ) 1.0 or less 0.5 Flammability (burning time) Within 120 seconds 0 Flammability (combustion length) 60 mm or less 0

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

A step (S100) of preparing foamed polystyrene particles by pulverizing styrofoam produced using expanded polystyrene to make expanded polystyrene particles having a predetermined particle size;
(S200) of preparing a foamed polystyrene particle mixture by mixing the expanded polystyrene particles with a silicate, an aluminum silicate and a heat insulating powder to be mixed to prepare a foamed polystyrene particle mixture;
A solvent and a binder mixing step (S300) for mixing and dissolving a solvent and a binder in the mixture;
(S400) in which the solvent and the binder are mixed using a stirrer to uniformly disperse and mix the mixture of the expanded polystyrene particles, the silicate, the aluminum silicate, and the heat insulating powder; And
And a forming step (S500) of adding the stirred mixture to a mold having a predetermined shape to produce a packing styrofoam,
As the styrofoam produced by using the expanded polystyrene in the expanded polystyrene particle producing step (S100), expanded styrofoam spherical particles, processed molded panels or foamed polystyrene styrofoam discarded during molding are used, milled using a cutting mill equipped with a knife bar and pulverized to a particle size of 300 to 800 mu m in irregular shape having an uneven size and shape,
In the silicate, the aluminum silicate and the heat insulating powder used in the foamed polystyrene particle mixture preparation step (S200), any one of sodium silicate, potassium silicate or lithium silicate is used as the silicate, and the silicate is the expanded polystyrene particle 100 And the aluminum silicate is contained in an amount of 3 to 8 parts by weight based on 100 parts by weight of the expanded polystyrene particles and the heat insulating powder is selected from the group consisting of diatomaceous earth, expanded vermiculite, zeolite, bentonite, perlite, And the heat insulating powder is contained in an amount of 0.5 to 5 parts by weight based on 100 parts by weight of the expanded polystyrene particles,
The modified limonene solvent is selected from the group consisting of hydroxyapatite, activated alumina, zeolite, clay and diatomaceous earth with respect to 100 parts by weight of the limonene solvent in the solvent and binder mixing step (S300) And 5 to 15 parts by weight of at least one compound is used. The binder is a magnesium phosphate-based inorganic binder, and the magnesium phosphate-based inorganic binder includes a magnesium-based metal oxide, a phosphate and a silica compound, Wherein the magnesium phosphate-based inorganic binder contains the expanded polystyrene particles, the silicate, the aluminum silicate, and the heat insulating powder in an amount of 80 to 100 parts by weight based on 100 parts by weight of the mixture of the expanded polystyrene particles, the silicate, the aluminum silicate, mix Mixture and 10 to 15 parts by weight, including the entire 100 parts by weight,
The solvent and binder mixing step (S300) further comprises a flame retardant adjuvant, wherein the flame retardant aid is contained in an amount of 2 to 5 parts by weight based on 100 parts by weight of the mixture of the expanded polystyrene particles, the silicate, the aluminum silicate and the heat insulating powder (Sb ₂ O ₃ , Sb ₂ O ₅ ), magnesium hydroxide, zinc borate, zinc sulfate, ammonium polyphosphate, and the like, the average particle size of the flame-retardant aid particles is 150 to 250 mesh. , A phosphorus flame retardant, a phosphate, and a yellow soil,
Wherein the stirring step (S400) is carried out at a stirring speed of 500 to 1000 rpm at a temperature of 50 to 65 DEG C for 1 to 2 hours.

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