KR101538719B1 - Method for Manufaturing Incombustible Sandwitch Panel Using Heat-expandable Adhesive - Google Patents

Abstract

The present invention relates to a thermal expandable adhesive forming an insulating layer by automatically foaming when the thermal expandable adhesive for an incombustible sandwich panel in order to attach heartwood, which is an insulator, to a steel plate, and having excellent fire resistance in order to maintain a foaming shape without being scattered after foaming, the incombustible sandwich panel using the same, and a manufacturing method thereof. According to the present invention, the thermal expandable adhesive for an incombustible sandwich panel comprises: solution A containing isocyanate; and solution B containing polyol, expandable graphite, and sugar phosphoric acid caramel or sugar silica caramel. The incombustible sandwich panel has a structure that the heartwood is connected by the thermal expandable adhesive between two steel plates or enables to cut off heat and to prevent penetration of harmful gas by an expansion of the thermal expandable adhesive in the event of fire as the sandwich panels are connected while the thermal expandable adhesive is coated in a connecting part between the sandwich panels.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a refractory sandwich panel using a thermally expandable adhesive,

The present invention relates to a refractory sandwich panel to which a thermally expandable adhesive is applied, and more particularly, to a refractory sandwich panel to which a core material is attached to a steel sheet, or a two-pack type thermally expandable adhesive for connecting a sandwich panel and a sandwich panel to each other, A thermally expandable adhesive capable of forming a foamed thermal insulation layer by heat-generating an adhesive by reacting with a certain ratio of polyol, liquid B mixed with sugar carnaic acid caramel (or sugar silica caramel) and expanded graphite, To a sandwich panel and a manufacturing method thereof.

A sandwich panel is a building material used for a building or a wall of a structure. The sandwich panel is manufactured by interposing a heat insulating material such as styrofoam between a pair of steel plates, and adhering the steel plate and the heat insulating material with an adhesive.

However, the styrofoam sandwiched between the steel plates of the sandwich panel has no fire resistance, and when the sandwich panel is exposed to the flame, such as when a fire occurs in the building, the styrofoam is burnt easily. In order to solve this problem, a method of applying a flame retardant to the surface of a styrofoam insulator, a method of foaming a styrofoam with a flame retardant applied to the surface of each foaming granule, a method of injecting a flame retardant into the inside of the styrofoam, .

Meanwhile, in the conventional sandwich panel, an adhesive is used to adhere the steel sheet and the heat insulating material. When the steel sheet is exposed to fire, the adhesive is directly burned due to the heat, There is a problem that it is easily transmitted to the insulation.

It has been reported that the flame retardancy of the adhesive is negligible. However, according to the experimental results, it has been reported that the flame retardancy of the sandwich panel is considerably different depending on the flame retardancy of the adhesive. That is, it is known that the polyurethane bond, which is a conventional general adhesive, is weak to a firearm and can not easily evolve once it is ignited, and adversely affects the human body with toxic gas and black smoke.

In advanced countries, it is urgent to develop heat-expandable adhesives for sandwich panels with fire resistance and adsorptivity to toxic gases, considering that the amount of adhesives used in the manufacture of sandwich panels is regulated in terms of flame retardancy and environment friendliness In fact.

In order to solve such a problem, a two-pack type adhesive manufactured by mixing A liquid and B liquid in Patent Publication No. 2009-0114898, wherein the liquid A contains isocyanate, the liquid B contains polyol, An adhesive comprising 5 to 35 parts by weight of an expandable filler with respect to 100 parts by weight of the adhesive, and a sandwich panel to which the adhesive is applied.

In addition, Japanese Patent Laid-Open No. 2008-0001702 discloses a heat foaming flame retardant coating agent which is foamed by heat to form a nonflammable carbonized layer. The thermal foaming flame retardant coating agent of the above-mentioned patent publication includes a mixture of a water dispersible rubber (Latex) with a saccharide including at least one of an expanded graphite powder, a melamine flame retardant, an ammonium phosphate flame retardant, a monosaccharide, a disaccharide, It is a material that does not contain a halogen-based flame retardant and is easily biodegradable. It has elasticity of rubber to maintain bending flexibility. When it is contacted with a flame, it fires more than 50 times the thickness of coating, So that no gas is generated.

Conventional heat-expandable adhesives including liquid-type adhesives or heat-foamable flame retardant coating agents as described above generally use polyurethane foam or expanded graphite as a mixture. However, simple mixing causes expansion of graphite when a fire occurs, However, since the low specific gravity of the expanded graphite and the binding force member cause it to be easily blown, the foaming layer is scattered and the continuous heat insulating layer can not be formed.

Further, in the case of diluting expanded graphite with an adhesive, expandable graphite can be foamed, but the flammability of the adhesive itself can not be suppressed.

Open Patent Publication No. 2009-0114898 (Published Date November 04, 2009) "Thermally expandable adhesive composition and sandwich panel manufactured using the same" Published Japanese Patent Application No. 2008-0001702 (Published Jan. 03, 2008) "Heat Foaming Flame Retardant Composition" Registered Utility Model No. 20-0391775 (registered Jul. 27, 2005) "Refractory panel using foam adhesive"

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the related art, and an object of the present invention is to provide a method for manufacturing a sandwich panel by using isocyanate and polyol used as an adhesive for a sandwich panel and adding expanded graphite and sugar silica caramel, A heat insulating layer formed by foaming, a foaming shape which is not scattered after foaming, and which has excellent fire resistance, and a fireproof sandwich panel using the same.

In order to achieve the above object, the present invention provides a thermally expandable adhesive for adhering a core material, which is a heat insulating material, to a steel sheet, or two sandwich panels each having an individual body, to each other, comprising: an A liquid containing an isocyanate; A heat-expandable adhesive for refractory sandwich panels characterized by comprising polyol, expandable graphite, and liquid B containing sugar caramel or sugar silica caramel.

One embodiment of a method for producing a sandwich panel using a heat-expandable adhesive for a fireproof sandwich panel according to the present invention is a method for producing a sandwich panel by mixing sucrose and phosphoric acid to form sugar caramel phosphate step; Mixing the polyol with the caramelized sugar caramel, expanded graphite and a dispersing agent to prepare a liquid B; And a step of applying and mixing the liquid B and the liquid A comprising isocyanate to the steel sheet to form a thermally expandable adhesive; And adhering a core material on the thermally expansible adhesive.

Another embodiment of a method for producing a sandwich panel using a thermally expandable adhesive for a fireproof sandwich panel according to the present invention comprises the steps of: preparing sugar silica caramel by adding and dissolving sugar to colloidal silica; Adding the above-mentioned sugar silica caramel and expanded graphite to a polyol and stirring to prepare liquid B; Applying the prepared solution A and the solution A comprising isocyanate to a steel sheet and mixing them to form a thermally expandable adhesive; And adhering a core material on the thermally expansible adhesive.

The present invention also provides a refractory sandwich panel comprising two steel plates spaced apart from each other by a certain distance, and a core member interposed between the steel plates and joined to the steel plate by the thermally expandable adhesive of the present invention.

According to one aspect of the refractory sandwich panel of the present invention, the sandwich panel is characterized in that a plurality of the sandwich panels are connected while being joined to each other by the thermally expandable adhesive.

The thermally expandable adhesive using the expanded graphite and the sugar valence phosphoric acid decomposition reaction according to the present invention has an effect that the foaming form is maintained without scattering due to plume pressure or wind pressure of fire.

In addition, it is possible to provide a thermally expandable adhesive which has a high expansion ratio and a hard carbon film, can block toxic gases, and is excellent in fire resistance.

In addition, when manufacturing a sandwich panel using a thermally expandable adhesive, it is possible to manufacture a sandwich panel using the existing equipment and production method as it is, thereby preventing an increase in manufacturing cost.

1 is a perspective view and an enlarged cross-sectional view of a fireproof sandwich panel according to the present invention.
2 is a perspective view showing a state in which a plurality of sandwich panels are joined and connected using a thermally expandable adhesive according to the present invention.
3 is a cross-sectional view showing a bonded state of the sandwich panel.
4 shows the molecular formula of sugar.
5 is a flowchart illustrating a method of manufacturing a refractory sandwich panel according to an embodiment of the present invention.
6A and 6B are enlarged views showing the state before expansion and the state after expansion of expanded graphite according to an embodiment of the present invention, respectively.
7 is a flowchart illustrating a method of manufacturing a refractory sandwich panel according to another embodiment of the present invention.
8 is a diagram showing a result of a first test of a fire-resistant sandwich panel to which a thermally expandable adhesive according to the present invention is applied.
9 to 11 are the official test results showing the results of the second test of the fire-resistant sandwich panel to which the thermally expandable adhesive according to the present invention is applied.
12 is a diagram showing a result of a third test of a fire-resistant sandwich panel to which a thermally expandable adhesive according to the present invention is applied.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A heat-expandable adhesive for a fire-resistant sandwich panel and a method for manufacturing a sandwich panel using the same according to the present invention will be described in detail with reference to the accompanying drawings.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

1, the refractory sandwich panel 10 has a structure in which a core material 12 as a heat insulator is interposed between two steel plates 11, and the core material 12 has a thermal expansion applied to the surface of the steel plate 11 And is firmly bonded to the steel plate 11 by the adhesive agent 13. The core 12 may have a honeycomb structure.

The thermally expandable adhesive (13) is characterized in that it is made of isocyanate and polyol, and is further reinforced by adding expanded graphite and carnauba-silica caramel. More specifically, the thermally expandable adhesive (13) is a liquid-type adhesive prepared by reacting liquid A and liquid B at a constant ratio, wherein liquid A is an isocyanate-based liquid, and liquid B is a mixture of expanded graphite and sugar phosphate It is made by adding caramel or sugar silica caramel.

The thermally expandable adhesive 13 made by mixing and stirring the liquid A and the liquid B has adhesiveness and thermal expansion property and has a separate mastic char (char type) so as not to scatter the expanded graphite foamed by heat, To keep the adiabatic and heat-shielding effect constant while suppressing the flammability of the medium (adhesive or substrate) and making the medium a part of Char.

The thermally expandable adhesive (13) has the characteristic that expandable graphite is added and expandable graphite is foamed upon contact with heat. The foam layer formed by the expanded graphite can maintain the best effect by keeping the foam form without scattering by the plume pressure or the wind pressure of the fire. To prevent such collapse, it is necessary to prevent the collapse of the mold. For this purpose, in the present invention, by using the mucilage of caramelized sugar caramel or caramelized sugar, it is possible to prevent the scattering of the foamed graphite and to suppress the combustion. Respectively.

The heat-expandable adhesive 13 of the present invention can be used not only for bonding the core 12 to the steel sheet 11 of the sandwich panel 10 as described above, The present invention can also be used for connecting a plurality of sandwich panels 10 by bonding them together. As the heat-expandable adhesive 13 expands when the fire is generated, the sandwich panel 10 and the sandwich panel 10, which are separated from each other, The heat and the harmful gas can not escape through the space 10, so that the fire resistance can be further improved.

A method of producing the thermally expandable adhesive of the present invention will be described below.

First, a method for preparing a thermo-expansive adhesive by adding caramel sugar phosphate in order to utilize the sugar-phosphoric acid decomposition reaction will be described.

In the sugar phosphatization reaction used in the present invention, sugar generally corresponds to? -D-glucopyranosyl-? -D-fructofranoside, and is a sweet, non-reducing disaccharide. Originally, it is contained in a large amount in sugar cane. What is obtained from sugar beet is called 柑 菜 sugar, and it is found in all plants that have photosynthesis ability. In the present invention, sugar which is generally produced is used.

Figure 4 is a molecular diagram of sugar.

Sugar is usually a disaccharide whose molecular formula is C ₁₂ H ₂₂ O ₁₁ , and the decomposition of sugar by heat is as follows:

The fact that a large amount of water is released by the above formula (1) is a special characteristic of the decomposition of sugar. Such sugar is environmentally harmless, easily biodegrades even when buried, and has no merit that no harmful gas is produced at the time of combustion.

On the other hand, when the sugar is hydrolyzed with dilute acid or? -D-fructosidase (sucrose, also referred to as invertase), an equivalent mixture of D-glucose and D-fructose (nonlinearity [α] D = -20 ° ), And the optical intensity is reversed to the left in the first place. This reaction is called telephone, and the mixed party is called telephone party. Sugar is also hydrolyzed to glucose and fructose by maltase III or IV in the mucosa cells. Some species of bacteria (Pseudomonas saccharophila, Leuconostoc mesen-teroides, etc.) have sugar sugar phosphoric acid decomposition in the presence of phosphoric acid to decompose sugar into α-D-glucose-1-phosphate and D-fructose. On the other hand, glycosylation of UDP-glucose to D-fructose or D-fructose-6-phosphate is known as an enzyme reaction for producing sugar. Although the former is catalyzed by sugar synthase (EC 2.4.1.13), it is physiologically more likely to act for the decomposition direction, ie, UDP-glucose supply, while the latter is responsible for sugar synthesis (SPS, EC 2.4.1.14). ≪ / RTI > The product, sugar phosphate, is converted to sugar by the irreversible dephosphorylation of phosphatase.

Cyanophilic acid means a reaction in which phosphoric acid is added to a molecule to decompose it. The enzyme that catalyzes this R1-R2 + H3PO4 R1-OPO3H2 + R2H reaction is collectively referred to as choline acidolytic enzyme, and glycogen phosphatase is representative. In the present invention, choline acidolytic enzymes are widely known in the industry by using choline acid decomposition of sugar, so they are not separately described in the present invention.

A method of producing the thermally expandable adhesive according to the present invention using the chiral acid decomposition reaction will be described with reference to FIG.

First, 100 parts by weight of disaccharide sugar is mixed with 20 to 70 parts by weight of phosphoric acid and reacted (step S1). This makes use of the above-mentioned sugar phosphoric acid decomposition reaction, and dark brown sugar caramel phosphate is formed as a final product thereof. Sucrose phosphate is a form of sugar 6-phosphate, and Sucrose-Phosphate Synthase is used as an enzyme to catalyze this reaction. The sugar 6-phosphoric acid, which is the product of the above, is amorphous and takes the form of caramel of unknown structure. When the sugar and phosphoric acid are mixed and reacted, aging may be required depending on the catalytic enzyme to be used.

On the other hand, in order to maintain the foaming form due to the expanded graphite to be described later, it is necessary to prevent the mold collapse. That is, caramelized sugar caramel is excellent in mucilage, so it exhibits a dual effect of preventing scattering of foamed graphite and suppressing combustion.

In this reaction, stabilizers or reaction accelerators may be added as other additives.

The foam stabilizer improves the emulsification action (facilitates the mixing of the raw materials) and the cell growth promotion (grows the bubbles, lowers the pressure difference between the bubbles, prevents gas diffusion, ), Stabilization of the cell membrane (prevention of problems such as cell destruction, coalescence and thinning of the cell membrane due to bubble destabilization at elevated viscosity) and added for product density uniformity.

Secondly, expanded graphite and a dispersant are added to the caramelized sugar phosphate, diluted and stirred to complete the liquid B (Step S2). At this time, 200 to 800 parts by weight of a urethane polyol is diluted with 100 parts by weight of caramelized sugar caramel and stirred. As the dispersing agent, a nonionic surfactant such as an ethylene oxide addition type surfactant can be used.

Here, the polyol for urethane generally includes initiators such as multifuntional alcohols or aromatic amines having two or more hydroxyl groups (-OH) or amine groups (Amine Group, -NH 2) in the molecule, and initiators such as propylene Oxide, PO) or ethylene oxide (EO) under appropriate conditions. Generally, polyols are classified into polyether polyols and polyester polyols. In the present invention, the polyols can be appropriately selected depending on the application.

Here, expandable graphite means that natural graphite is subjected to chemical treatment to form an intercalation compound of graphite. When such a compound is heated, it expands together with the chemical component to form a kind of film. When the styrofoam or urethane containing expanded graphite receives heat, that is, when a fire occurs, the expanded film acts as a protective film, . The foam layer formed by the expanded graphite does not scatter due to the plume pressure or the wind pressure of the fire but the foam form is maintained.

6A and 6B are enlarged views showing the state before expansion and the state after expansion, respectively, of expanded graphite. Expanded graphite, also known as soft graphite, is widely used in industry, so a detailed description is not given here.

On the other hand, a solution prepared by mixing solid sodium octaborate tetrahydrate with colloidal meta silicate is added to the second step (step S2) to reinforce the flame retardancy. This sodium octaborate solution plays a role in suppressing the combustion of the combustible base material and helping the formation of Char when the adhesive component or the combustion component is mixed.

When sodium octaborate solution is formed, 10 to 40 parts by weight of a colloidal meta-silicate is mixed with 100 parts by weight of sodium octaborate tetrahydrate. When the sodium octaborate solution thus produced is mixed with caramelized sugar, 10 to 50 parts by weight of sodium octaborate solution is added to 100 parts by weight of caramelized sugar caramel.

At this time, petroleum or vaseline may be added to maintain the viscosity of the liquid B.

Third, the B liquid made of the caramelized sugar caramel and the polyol for urethane and the A liquid containing the isocyanate as the main component are sprayed on the steel sheet and mixed and reacted using a mixing plate to produce a thermally expandable adhesive (step S3). In this embodiment, methylene diphenyl diisocyanate (MDI) was used as an isocyanate.

Here, methylene diphenyl diisocyanate (MDI) is an aromatic diisocyanate chemical substance. The methylene diphenyl diisocyanate is largely divided into MDI monomer and polymeric MDI. The MDI monomer is composed of three isomers of 2,2'-MDI, 2,4'-MDI and 4,4'-MDI, , One of the three isomers or a mixture thereof is selected to be suitable for the purpose.

After the heat-expandable adhesive 13 is applied on the steel sheet 11 through the above process, the core material 12 is placed on the heat-expandable adhesive 13 and pressed to attach the sandwich panel.

As described above, according to the present invention, the liquid A and liquid B constituting the heat-expandable adhesive 13 are applied between the steel sheet 11 and the core material 12 of the sandwich panel and adhered to each other (step S4) Semi-fire-resistant material. In this case, the process for manufacturing the sandwich panel is the same as that of the conventional coating and bonding method, and thus the workability is excellent and the coating amount can be adjusted according to the flame retardant performance. As a result of an experiment conducted by the present applicant, it was confirmed that about 200 to 1000 g / m ² was good.

On the other hand, in the above-described embodiment, when the liquid B of the liquid type heat-expandable adhesive is produced, the caramel phosphate is added together with the polyol and the expanded graphite, but the liquid B of the thermally expandable adhesive can also be prepared by adding the sugar silica caramel have.

Referring to FIG. 7, sugar silica caramel is prepared by adding and dissolving 50 to 80 parts by weight of sugar relative to 100 parts by weight of colloidal silica (step S11).

Then, 15 to 30 parts by weight of caramelized sugar silica and 20 to 50 parts by weight of expanded graphite are added to 100 parts by weight of a polyol having a molecular weight of 1000 g / mol to 3000 g / mol and stirred (Step S12).

Next, a surfactant, a solvent, a flame retardant, a catalyst and an auxiliary agent are added to the product produced in the step S12 and stirred to complete the liquid B (step S13). At this time, when mixing the sugar silica caramel and the expanded graphite, sodium octaborate tetrahydrate in a solid form may be added to the colloidal meta-silicate to form a sodium octaborate solution. In forming the sodium octaborate solution, 10 to 40 parts by weight of a colloidal-type meta-silicate is preferably mixed with 100 parts by weight of sodium octaborate tetrahydrate.

Further, in the step of preparing the liquid B, at least one of petroleum or petrolatum may be further added to maintain the viscosity of the liquid B.

The urea reaction is started by spraying the B liquid prepared as described above and the A liquid of the isocyanate system on the steel plate in the actual process line and stirring through the mixing plate (step S14), and the sandwich panel The production method is the same as that of the conventional coating and adhering method, but in order to manufacture a flame retardant or semi-flammable panel, a coating amount of 200 to 1000 g / m 2 is required depending on the flame retardant performance.

A primary test was conducted manually by using a thermally expandable adhesive (13) obtained by mixing the liquid B and the liquid A produced by the manufacturing method according to the present invention. Solution B was prepared by charging 20 parts by weight of caramel of sugar silica and 20 parts by weight of expanded graphite to 100 parts by weight of polyol.

A sandwich panel specimen was prepared using a two-pack type heat-expandable adhesive composed of the liquid B and an isocyanate-based liquid A, using a density of EPS (Expanded Polystyrene) insulating material of 8.9 kg / m 3 and a zinc sheet of 0.4 mm Test.

8 shows the state of the sandwich panel specimen, the photographs after the cone calorie test, and the test results.

In the second phase of the silane test, the EPS sandwich panel specimen was fabricated by adjusting the blending ratio in consideration of the storage stability in September, 2012, and subjected to an authorized test.

In the third test, the adhesive viscosity was 1200 cps, and the sandwich panel test specimens were manufactured in such a manner that the contents were 400 g / m 2 and 600 g / m 2 as compared with the steel sheet area. As a result, as shown in FIG. 10, When general adhesives were used, the total calorific value was 9.5 MJ / m 2, which is higher than the allowable reference value of 8 MJ / m 2. However, when the thermally expandable adhesive of the present invention is used in general EPS, the total calorific value is much lower than the allowable reference value of 8 MJ / 5.1 MJ / m < 2 > and 5.2 MJ / m < 2 >

As described above, the sandwich panel of the present invention is characterized in that the core 12 is attached to the steel plate 11, or the heat-expandable adhesive 13 for bonding the plurality of sandwich panels 10, (13) is added to the liquid B of the thermo-expansive adhesive (13), or due to the excellent toughness of the sugar caramel caramel, It is possible to obtain a double effect in which scattering of graphite is prevented and combustion is suppressed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is clear that the present invention can be suitably modified and applied in the same manner. Therefore, the above description does not limit the scope of the present invention, which is defined by the limitations of the following claims.

10: Sandwich panel 11: Steel plate
12: core material 13: thermally expandable adhesive

Claims (21)

delete An A liquid containing an isocyanate; CLAIMS What is claimed is: 1. A method of making a sandwich panel using a thermally expandable adhesive comprising polyol, expandable graphite, and liquid B containing sugar caramel caramel or sugar silica caramel,
A step of mixing saccharose and phosphoric acid to form saccharin phosphate caramel by decomposition of sugar with phosphoric acid;
Mixing the polyol with the caramelized sugar caramel, expanded graphite and a dispersing agent to prepare a liquid B; And
Applying the prepared solution A and the solution A comprising isocyanate to the steel sheet 11 and mixing them to form a thermally expandable adhesive;
And adhering a core material (12) on the thermally expandable adhesive. The method of manufacturing a fireproof sandwich panel using the thermally expandable adhesive. [3] The method of claim 2, wherein a foam stabilizer is added during the caramel sugar phosphate formation. The method of claim 2, wherein the sugar phosphate-caramel is formed by adding sucrose-phosphate synthase to the refractory sandwich panel. [3] The method of claim 2, wherein 20 to 70 parts by weight of phosphoric acid is mixed with 100 parts by weight of the sugar when forming the caramelized sugar. [3] The method of claim 2, wherein 200 to 800 parts by weight of polyol is mixed with 100 parts by weight of caramel sugar phosphate. [7] The method of claim 6, wherein the polyol is at least one of a polyether polyol and a polyester polyol. [3] The method of claim 2, wherein the isocyanate is methylene diphenyl diisocyanate (MDI). The method of claim 8, wherein the methylenediphenyl isocyanate is any one of MDI monomer and polymeric MDI having at least one of 2,2'-MDI, 2,4'-MDI, and 4,4'-MDI. Wherein the heat-expandable adhesive is applied to the panel. [Claim 3] The method according to claim 2, wherein, in the step of preparing the liquid B, sodium octaborate tetrahydrate in solid form is mixed with meta-silicate on the colloid during the mixing of the expanded graphite with the sugar caramel Wherein the heat-expandable adhesive is a heat-resistant adhesive. The method of claim 10, wherein 10 to 40 parts by weight of the colloidal-type meta-silicate is mixed with 100 parts by weight of sodium octaborate tetrahydrate when forming the sodium octaborate solution. 12. The refractory sandwich panel according to claim 11, wherein when the sodium octaborate solution is mixed with caramel sugar phosphate, 10 to 50 parts by weight of sodium octaborate solution is mixed with 100 parts by weight of caramel sugar phosphate. Gt; The method of manufacturing a fireproof sandwich panel according to claim 2, wherein at least one of petroleum or petroleum jelly is further added to maintain the viscosity of the liquid B in the step of preparing the liquid B. An A liquid containing an isocyanate; CLAIMS What is claimed is: 1. A method of making a sandwich panel using a thermally expandable adhesive comprising polyol, expandable graphite, and liquid B containing sugar caramel caramel or sugar silica caramel,
Preparing a sugar silica caramel by adding and dissolving sugar to colloidal silica;
Adding the above-mentioned sugar silica caramel and expanded graphite to a polyol and stirring to prepare liquid B;
Applying the prepared solution A and the solution A comprising isocyanate to the steel sheet 11 and mixing them to form a thermally expandable adhesive;
And adhering a core material (12) on the thermally expandable adhesive. The method of manufacturing a fireproof sandwich panel using the thermally expandable adhesive. 15. The method of claim 14, wherein the sugar silica caramel is prepared by dissolving 50 to 80 parts by weight of sugar relative to 100 parts by weight of colloidal silica. 15. The method according to claim 14, wherein in the step of preparing the liquid B, 15 to 30 parts by weight of carmellum of sugar silica and 20 to 50 parts by weight of expanded graphite are added to 100 parts by weight of polyol having a molecular weight of 1000 to 3000 g / A method for manufacturing a refractory sandwich panel using a thermally expandable adhesive. 15. The method according to claim 14, characterized in adding sodium octaborate solution produced by mixing solid sodium octaborate tetrahydrate with colloidal meta-silicate during the mixing of the sugar silica caramel and expanded graphite in the step of producing the liquid B Wherein the heat-expandable adhesive is a heat-resistant adhesive. 18. The method of claim 17, wherein the sodium octaborate solution is mixed with 10 to 40 parts by weight of a colloidal meta-silicate relative to 100 parts by weight of sodium octaborate tetrahydrate. 15. The method for manufacturing a fireproof sandwich panel using the thermally expandable adhesive according to claim 14, wherein at least one of petroleum or vaseline is further added to maintain the viscosity of the liquid B in the step of preparing the liquid B . delete delete

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