KR102649459B1 - Manufacturing method of flame-retardant urethane foam - Google Patents

Abstract

The present invention is intended to solve the above problems and relates to a method of manufacturing flame-retardant urethane foam that exhibits excellent flame retardant performance while maintaining high elasticity and does not generate toxic gas in the event of a fire. To this end, the manufacturing method includes preparing a first mixture containing a polyol mixture, expanded graphite, a flame retardant, and a dispersant; Preparing a second mixture containing an isocyanate-based curing agent and a foaming accelerator; Adding the second mixture to the first mixture and simultaneously injecting nitrogen gas using a foamer to foam it to form urethane foam; and heat-treating the urethane foam at a temperature range of 60°C to 180°C.

Description

Flame retardant urethane foam manufacturing method {MANUFACTURING METHOD OF FLAME-RETARDANT URETHANE FOAM}

The present invention is intended to solve the above problems and relates to a method of manufacturing flame-retardant urethane foam that exhibits excellent flame retardant performance while maintaining high elasticity and does not generate toxic gas in the event of a fire.

In general, urethane foam is relatively inexpensive, easy to form, and has high elasticity, so it is widely used throughout household goods, including automobile parts, building materials, and machine parts materials.

Specifically, urethane foam is a urethane resin that is foamed and composed of bubbles and a diaphragm. More specifically, the chemical foaming agent premixed in the polyol premix reacts with isocyanate to generate gas, or the physical foaming agent reacts with isocyanate during the urethane bonding reaction. The heat generated causes a phase change to generate gas, forming bubbles with boundaries.

Mechanical properties deteriorate when bubbles are formed during the production of urethane foam, but by reducing weight due to low density, saving material, improving shock absorption and specific strength, improving anti-responsiveness and insulation, and compensating for volumetric shrinkage due to density changes during curing of the base material. It has the advantage of stabilizing the dimensions of the product, the density of the foam can be adjusted relatively freely, and the foam can be easily foamed without restrictions on location.

Such urethane foam can be classified into soft, semi-hard, hard, etc. depending on its hardness. Soft urethane foam is used as cushioning material, filler, filter, building interior material, sound-absorbing panel, etc. for automobiles, etc., and semi-hard urethane foam is used for heat absorption. It is used as an electrical insulating material, and rigid urethane foam is widely used as aircraft and mechanical parts materials, industrial and household insulation materials, and soundproofing plates.

However, this urethane foam is flammable, and once ignited, it had the fatal problem of burning out of control.

In order to solve this problem, a method of imparting flame retardancy by laminating flame retardant sheets or panels on one side of polyurethane foam was mainly used. Since this does not fundamentally impart flame retardancy to polyurethane foam, the flame retardant effect is was limited, the manufacturing process was complicated, and there were problems that increased manufacturing costs.

In addition, flame retardants composed of halogen compounds such as bromine compounds or chlorine compounds are added to provide flame retardancy to the urethane foam itself, which can cause human and environmental problems due to toxic gases when burned.

Accordingly, there is a need for research on urethane foam that maintains the high elasticity of urethane foam and improves flame retardant and non-combustible properties.

Republic of Korea Patent Publication No. 10-1638255

The present invention is intended to solve the above problems, and seeks to provide a method of manufacturing flame-retardant urethane foam that exhibits excellent flame retardant performance while maintaining high elasticity and does not generate toxic gas in the event of a fire.

The above and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

The object includes preparing a first mixture comprising a polyol mixture, expanded graphite, a flame retardant, and a dispersant; Preparing a second mixture containing an isocyanate-based curing agent and a foaming accelerator; Adding the second mixture to the first mixture and simultaneously injecting nitrogen gas using a foamer to foam it to form urethane foam; and heat-treating the urethane foam in a temperature range of 60°C to 180°C.

Specifically, the polyol mixture may be characterized as including one or more selected from the group consisting of polyester-based polyol, polyether-based polyol, polycaprolactone-based polyol, and combinations thereof.

Specifically, the flame retardant may be characterized as including a non-halogen-type flame retardant.

Preferably, the non-halogen-type flame retardant may include a phosphorus-based flame retardant or a melamine-based flame retardant.

Specifically, the isocyanate-based curing agent is ethylene diisocyanate, methylene diisocyanate, modified methylene diphenyl diisocyanate, toluene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12- It may be characterized as comprising one or more selected from the group consisting of dodecane diisocyanate, and combinations thereof.

Specifically, the foaming accelerator may include one or more selected from the group consisting of potassium octate, potassium acetate, bismuth-based gel catalyst, tin-based catalyst, and combinations thereof.

Specifically, the first mixture may further include a carbon dioxide adsorbent.

Specifically, the first mixture may further include ammonium phosphate.

According to the present invention, it is possible to manufacture urethane foam that exhibits excellent flame retardant performance even at high temperatures, does not spread flames in the event of fire, and does not generate toxic gases, causing human and environmental problems.

In addition, the urethane foam manufactured by the method according to the present invention is not only easy to construct due to its excellent foamability and moldability, but also exhibits excellent compressive strength and dimensional stability and can maintain elasticity.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Hereinafter, the present invention will be described in detail with reference to embodiments of the present invention and drawings. These examples are merely presented as examples to explain the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. .

Additionally, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains, and in case of conflict, this specification including definitions The description will take precedence.

In order to clearly explain the proposed invention in the drawings, parts unrelated to the description have been omitted, and similar reference numerals have been assigned to similar parts throughout the specification. And, when it is said that a part "includes" a certain component, this means that it does not exclude other components, but may further include other components, unless specifically stated to the contrary. Additionally, “unit” as used in the specification refers to a unit or block that performs a specific function.

Identification codes (first, second, etc.) for each step are used for convenience of explanation. The identification codes do not describe the order of each step, and each step does not clearly state a specific order in context. It may be carried out differently from the order specified above. That is, each step may be performed in the same order as specified, may be performed substantially simultaneously, or may be performed in the opposite order.

Hereinafter, implementation examples and examples of the present application will be described in detail with reference to the attached drawings. However, the present disclosure may not be limited to these implementations, examples, and drawings.

One aspect of the present disclosure includes preparing a first mixture comprising a polyol mixture, expanded graphite, a flame retardant, and a dispersant; Preparing a second mixture containing an isocyanate-based curing agent and a foaming accelerator; Adding the second mixture to the first mixture and simultaneously injecting nitrogen gas using a foamer to foam it to form urethane foam; and heat-treating the urethane foam in a temperature range of 60°C to 180°C.

According to the present invention, it is possible to manufacture urethane foam that exhibits excellent flame retardant performance even at high temperatures, does not spread flames in the event of fire, and does not generate toxic gases, causing human and environmental problems. In addition, the urethane foam manufactured by the method according to the present invention is not only easy to construct due to its excellent foamability and moldability, but also exhibits excellent compressive strength and dimensional stability and can maintain elasticity.

In order to manufacture flame-retardant urethane foam according to the present invention, first prepare a first mixture containing a polyol mixture, expanded graphite, a flame retardant, and a dispersant.

In one embodiment, the polyol mixture may have a weight average molecular weight ranging from about 100 to about 5,000 g/mol. As the weight average molecular weight polyol mixture described above is used, the produced urethane foam may have excellent physical properties and exhibit high elasticity.

In one embodiment, the polyol mixture may include one or more selected from the group consisting of polyester-based polyol, polyether-based polyol, polycaprolactone-based polyol, and combinations thereof.

At this time, the polyester-based polyol has excellent tensile strength, thermal stability, and chemical resistance due to the strong interaction of the ester bond, and can exhibit good elasticity even at low temperatures. In consideration of the above-mentioned improvement effect, the polyester-based polyol is preferably contained in the range of about 40 to about 80% by weight in the polyol mixture.

In one embodiment, the polyester-based polyol may be preferably obtained by condensation of dicarboxylic acid and diol. At this time, non-limiting examples of the dicarboxylic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azera phosphoric acid, sebacic acid, phthalic acid, terephthalic acid, isophthalic acid, maleic acid, fumaric acid, At least one selected from the group consisting of itaconic acid, tetrabromophthalic acid, trimeritic acid or their ester derivatives, acid anhydrides, and mixtures thereof can be preferably used. In addition, non-limiting examples of the diol include ethylene glycol, propylene glycol, butanediol, pentanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, trimethylolpropane, glycerin, and pentaerythritol. , quinitol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, lipopylene glycol, diglycerin, dextrose, sorbitol, and mixtures thereof. there is.

In one embodiment, the polyether-based polyol may preferably be obtained by polymerizing a polyfunctional alcohol or a polyfunctional amine and alkylene oxide. At this time, non-limiting examples of the polyfunctional alcohol include ethylene glycol, diethylene glycol, glycerin, trimethanol propane, pentaerythritol, dipentaerythritol, a-methyl glucoside, xylitol, sorbitol, sugar, and mixtures thereof. One or more types selected from the group consisting of can be preferably used. In addition, non-limiting examples of the multifunctional amine include one selected from the group consisting of ethylenediamine, diethylenetriamine, triethanolamine, ortho-toluenediamine, diphenylmethanediamine, diethanolamine, and mixtures thereof. The above can be preferably used.

The polycaprolactone-based polyol functions to improve heat resistance, water resistance, and workability. In consideration of the above-described improvement effect, the polycaprolactone-based polyol is preferably contained in the polyol mixture in the range of about 20 to about 60% by weight.

More specifically, the polycaprolactone-based polyol can preferably be one obtained by ring-opening polymerization of ε-caprolactone using a polyol initiator or a polyamine initiator. At this time, non-limiting examples of the polyol initiator include ethylene glycol, propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,6-hexanediol, neopentyl glycol, bisphenol A, and reso. Diols such as Resin; Triols such as glycerin, 1,2,6-hexanetriol, and 1,1,1-tris(hydroxymethyl)propane; tetraols such as pentaerythritol, erythritol, and methylglucoxide; Hexaol such as sorbitol and dipentaerythritol; At least one selected from the group consisting of octanol such as sucrose and mixtures thereof can be preferably used.

For example, the commercially available polycaprolactone-based polyols include ToneTM 0240, 1241, 2241, or 1231; CapaTM 2043, 2077A, 2100A, 2125, 2205, 2201, 2101A, 2123A, 2161A, 2200A, 2200D, 2200P, 2201A, 2203A, 2209, 2302A, 2303, 2304, 2 402, 2403D, 2054, 2803, 3022, 3031, 3041 , 3091, 3201, 3301, 4801, 7201A, 7203, HCl060, or HCl100; Alternatively, one or more selected from the group consisting of PlaccelTM 205, 208, 210, 220, 220 CPB, 230, 230 CP, 240 or 240 CP, and mixtures thereof may be preferably used.

In one embodiment, the flame retardant may include a non-halogen-type flame retardant.

In one embodiment, the non-halogen-type flame retardant may include a phosphorus-based flame retardant or a melamine-based flame retardant, and specifically may include a phosphorus-based flame retardant.

In one embodiment, the phosphorus-based flame retardant is diethyl-N,N-bis (2-hydroxyethyl) aminomethyl phosphonate, (tris (2-chloropropyl) phosphate, tris (2-chloroethyl) phosphate. , and combinations thereof. Specifically, the phosphorus-based flame retardant includes diethyl-N,N-bis(2-hydroxyethyl)aminomethyl phosphonate. It may be.

In one embodiment, the phosphorus-based flame retardant may be included in an amount of about 30 to about 60 parts by weight based on 100 parts by weight of the total polyol mixture. If the phosphorus-based flame retardant is included in less than about 30 parts by weight compared to the total 100 parts by weight of the polyol mixture, the flame retardant performance of the manufactured urethane foam may decrease, and if it exceeds about 60 parts by weight, workability may decrease.

In one embodiment, the flame retardant may include titanium dioxide and calcium silicate as a mineral-based flame retardant in addition to a phosphorus-based flame retardant or a melamine-based flame retardant. When manufacturing urethane foam including the mineral-based flame retardant, it can exhibit excellent dimensional stability and physical properties, and has excellent flame retardant performance without generating toxic gas in the event of fire, showing the advantage of not spreading flames.

In one embodiment, the titanium dioxide and calcium silicate may each be included in an amount of about 5 to about 15 parts by weight based on 100 parts by weight of the total polyol mixture. If the titanium dioxide and calcium silicate are included in less than about 5 parts by weight relative to the total 100 parts by weight of the polyol mixture, the mechanical properties of the manufactured urethane foam may decrease, and if they exceed about 15 parts by weight, they may be mixed with other components. Sexuality may be impaired.

In one embodiment, the expanded graphite may be included to improve excellent flame retardancy and self-extinguishing performance. The expanded graphite has a layered crystal structure, and when heated, expands to about 20 to 400 times its original size, thereby inducing the formation of porous carbides during combustion, thereby further improving excellent flame retardancy and self-extinguishing properties.

In one embodiment, the expanded graphite may be included in an amount of about 1 to about 10 parts by weight based on 100 parts by weight of the total polyol mixture. If the expanded graphite is included in less than about 1 part by weight compared to the total 100 parts by weight of the polyol mixture, the flame retardant and self-extinguishing performance achieved by including the expanded graphite may not be sufficiently demonstrated, and if it exceeds about 10 parts by weight. This may result in a decrease in strength.

In one embodiment, the dispersant may include one or more selected from the group consisting of ethanol, dimethylformamide (DMF), dimethylacetamide, tetrahydrofuran, and combinations thereof. Preferably, the dispersant may include dimethylformamide.

In one embodiment, the dispersant may be included in an amount of about 1 to about 10 parts by weight based on 100 parts by weight of the total polyol mixture. If the dispersant is included in less than about 1 part by weight compared to the total 100 parts by weight of the polyol mixture, the miscibility of the components may be impaired, and if it exceeds about 10 parts by weight, workability may be reduced.

Next, prepare a second mixture containing an isocyanate-based curing agent and a foaming accelerator.

Next, the second mixture is added to the first mixture and nitrogen gas is injected using a foamer to foam the mixture to form urethane foam. At this time, the first mixture and the second mixture may be mixed at a weight ratio of about 1:0.1 to 0.5. If the second mixture is mixed at a weight ratio of less than about 0.1, expansion may not occur sufficiently, and if the second mixture is mixed at a weight ratio of less than about 0.5, workability may decrease. Preferably, the first mixture and the second mixture may be mixed at a weight ratio of about 1:0.2 to 0.5.

Finally, the urethane foam is heat treated and hardened.

In one embodiment, the step of heat treating the urethane foam may be performed at a temperature range of about 60°C to about 180°C. If the heat treatment step is performed below about 60°C, hardening may not proceed sufficiently, and if it exceeds about 180°C, worker safety may decrease due to excessively high heat treatment.

In one embodiment, the isocyanate-based curing agent is ethylene diisocyanate, methylene diisocyanate, modified methylene diphenyl diisocyanate, toluene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1 , 12-dodecane diisocyanate, and combinations thereof. Specifically, the isocyanate-based curing agent may include methylene diisocyanate.

In one embodiment, the foaming accelerator includes at least one selected from the group consisting of potassium octate, potassium acetate, bismuth-based gel catalyst, tin-based catalyst, and combinations thereof, thereby facilitating the reaction between the polyol and isocyanate. Curing time can be shortened. Specifically, the foaming accelerator may include potassium octate.

In one embodiment, the foaming accelerator may be included in an amount of about 10 to about 25 parts by weight based on 100 parts by weight of the isocyanate-based curing agent. If the foaming accelerator is included in less than about 10 parts by weight compared to the total 100 parts by weight of the isocyanate-based curing agent, foaming may not sufficiently occur when mixing the first mixture and the second mixture, and if it exceeds about 25 parts by weight, workability may be impaired. This may fall.

In one embodiment, the first mixture further includes a carbon dioxide adsorbent, thereby protecting the user's safety by adsorbing carbon dioxide in the event of a fire.

In one embodiment, the carbon dioxide adsorbent includes a lithium compound selected from the group consisting of Li ₂ O, Li ₂ CO ₃ , LiOH, LiNO ₃ , LiCl, LiBr, and combinations thereof, and magnesium oxide (MgO). It may be. Specifically, the carbon dioxide adsorbent may include LiNO ₃ -MgO, which is a mixture of LiNO ₃ and magnesium oxide.

In one embodiment, the carbon dioxide adsorbent is prepared by mixing and calcining a lithium compound salt selected from the group consisting of Li ₂ O, Li ₂ CO ₃ , LiOH, LiNO ₃ , LiCl, LiBr, and combinations thereof, and magnesium oxide. It may be manufactured. For example, the carbon dioxide adsorbent may be manufactured by dispersing or dissolving a lithium compound salt in an organic solvent, mixing it with magnesium oxide, and calcining it in a temperature range of about 300°C to about 500°C.

In one embodiment, the carbon dioxide adsorbent may adsorb carbon dioxide in a temperature range of about 200°C to about 800°C. For example, when manufacturing urethane foam by including the carbon dioxide adsorbent, user safety can be maintained by adsorbing carbon dioxide in the temperature range of about 200°C to about 800°C in the event of a fire.

In one embodiment, the element ratio of lithium and magnesium in the carbon dioxide adsorbent may be Mg:Li = about 1: about 1 to 5, but may not be limited thereto. For example, as the elemental ratio of lithium and magnesium in the carbon dioxide adsorbent changes, the adsorption rate of carbon dioxide may change. Specifically, as the elemental ratio of lithium increases, the adsorption rate of carbon dioxide may increase.

In one embodiment, the carbon dioxide adsorbent may be included in an amount of about 5 to about 15 parts by weight based on 100 parts by weight of the total polyol mixture. If the carbon dioxide adsorbent is included in an amount of less than about 5 parts by weight relative to the total 100 parts by weight of the polyol mixture, the adsorption performance resulting from the additional inclusion of the carbon dioxide adsorbent may not be sufficiently achieved, and if it exceeds about 15 parts by weight, other Mixability with ingredients may be impaired.

In one embodiment, the first mixture may improve the flame retardant performance of the urethane foam manufactured by additionally including ammonium phosphate. The ammonium phosphate is, for example, monobasic ammonium phosphate [(NH ₄ )H ₂ PO ₄ , Mono-ammonium Phosphate, MAP], dibasic ammonium phosphate [(NH ₄ ) ₂ HPO ₄ ], triteric ammonium phosphate [ (NH ₄ ) ₃ PO ₄ ], ammonium polyphosphate (APP), and combinations thereof. The monobasic ammonium phosphate, diammonium phosphate, tritertiary ammonium phosphate, and ammonium polyphosphate are characterized by strong flame retardancy due to the combination of phosphorus and nitrogen.

In one embodiment, the first mixture may further include ammonium phosphate, and preferably may include both monobasic ammonium phosphate and ammonium polyphosphate.

In one embodiment, the monobasic ammonium phosphate and ammonium polyphosphate may each be included in an amount of about 1 to about 10 parts by weight based on 100 parts by weight of the total polyol mixture. If the ammonium monobasic phosphate and ammonium polyphosphate are each included in an amount of less than about 1 part by weight based on 100 parts by weight of the polyol mixture, the flame retardant performance achieved by additionally including the ammonium monobasic phosphate and ammonium polyphosphate is sufficiently demonstrated. If it exceeds about 10 parts by weight, miscibility with other ingredients may be impaired.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through specific examples and comparative examples. However, these examples are for illustrating the present invention in more detail, and the scope of the present invention is not limited to these examples.

[Example 1]

First, 10 parts by weight of expanded graphite and diethyl-N,N-bis as a phosphorus-based flame retardant are added to a polyol mixture (a mixture of 60% by weight of polyester polyol and 40% by weight of polycaprolactone polyol) based on 100 parts by weight of the total polyol mixture. 55 parts by weight of (2-hydroxyethyl)aminomethyl phosphonate, 10 parts by weight of dimethylformamide as a dispersant, 7.5 parts by weight of titanium dioxide powder, and 7.5 parts by weight of calcium silicate powder were sequentially mixed and stirred to form a first mixture.

Next, methylene diisocyanate (NCO: 29-32%) and 20 parts by weight of potassium octate, a foaming accelerator, based on a total of 100 parts by weight of the methylene diisocyanate were mixed to form a second mixture.

Thereafter, the second mixture was added to the first mixture at a weight ratio of 1:0.5, and nitrogen gas was injected and foamed using a spray foamer to form urethane foam. The formed urethane foam was cured by applying heat at 150°C to obtain the urethane foam of Example 1.

[Example 2]

Prepared in the same manner as in Example 1, except that when preparing the first mixture, 3.5 parts by weight of the LiNO ₃ -MgO mixture was additionally included as a carbon dioxide adsorbent based on 100 parts by weight of the polyol mixture, and the first mixture was added to the first mixture. The urethane foam of Example 2 was obtained by adding the second mixture at a weight ratio of 1:0.5, foaming it by injecting nitrogen gas using a spray foamer, and then curing it by applying heat at 150°C.

[Example 3]

Prepared in the same manner as in Example 1, except that when preparing the first mixture, 3.5 parts by weight of LiNO ₃ -MgO mixture, 7.5 parts by weight of monobasic ammonium phosphate, and 10 parts by weight of ammonium polyphosphate were added based on 100 parts by weight of the polyol mixture. A first mixture was prepared, and the second mixture was added to the first mixture at a weight ratio of 1:0.5, foamed by injecting nitrogen gas using a spray foamer, and then cured by applying heat at 150 ° C. Urethane foam was obtained.

[Comparative example]

A first mixture was prepared by mixing polycaprolactone-based polyol with a flame retardant (50 parts by weight of tris(2-chloropropyl) phosphate and 20 parts by weight of foaming agent HCFC-141b based on 100 parts by weight of the total polycaprolactone-based polyol. The first mixture was prepared. Methylene diisocyanate (NCO: 29-32%) was reacted with the mixture at a ratio of 1:0.5 to form urethane foam, which was named Comparative Example.

[Experimental Example 1: Physical property evaluation]

Physical properties including density, compressive strength, and tensile strength were evaluated based on ASTM D3574-01, ASTM D1621, and ISO 1926 for each of the urethane foams manufactured in the above examples and comparative examples, and the results are shown in Table 1 below. It was.

division Example 1 Example 2 Example 3 Comparative example Density (g/cm ³ ) 0.19 0.23 0.36 0.12 Compressive strength (MPa) 1.8 2.1 2.3 1.3 Tensile strength (MPa) 1.9 2.3 2.6 1.0

As shown in Table 1, it was confirmed that the urethane foam of the example manufactured by the manufacturing method according to the present invention exhibited superior physical properties and excellent shock absorption compared to the comparative example.

[Experimental Example 2: Evaluation of flame retardant properties - (1)]

Gas toxicity was measured for each of the urethane foams manufactured in the above examples and comparative examples in accordance with KS F 2271, and the results are shown in Table 2 below. The evaluation method quantifies the degree of excellence within the range of 1 to 10 (1: bad, ~5: average, ~10: excellent).

division Example 1 Example 2 Example 3 Comparative example Gas hazard test evaluation results 7.1 7.4 8.1 6.0

As shown in Table 2, it was confirmed that the urethane foam of the example manufactured by the manufacturing method according to the present invention exhibited excellent flame retardant performance compared to the comparative example.

[Experimental Example 2: Evaluation of flame retardant properties - (2)]

The heat release rate was measured for each of the urethane foams manufactured in the above examples and comparative examples according to KS F ISO 5660-1, and the results are shown in Table 3 below. The evaluation method quantifies the degree of excellence within the range of 1 to 10 (1: bad, ~5: average, ~10: excellent).

division Example 1 Example 2 Example 3 Comparative example Heat release rate test evaluation results 8.1 8.7 9.5 7.1

As shown in Table 3, it was confirmed that the urethane foam of the example manufactured by the manufacturing method according to the present invention exhibited superior flame retardant performance compared to the comparative example.

In this specification, only a few examples are described among the various embodiments performed by the present inventors, but the technical idea of the present invention is not limited or restricted thereto, and of course, it can be modified and implemented in various ways by those skilled in the art.

Claims (8)

A polyol mixture having a weight average molecular weight in the range of 100 to 5,000 g/mol and containing 40 to 80% by weight of polyester-based polyol and 20 to 60% by weight of polycaprolactone-based polyol, 1 expanded graphite relative to 100 parts by weight of the total polyol mixture. to 10 parts by weight, diethyl-N,N-bis(2-hydroxyethyl)aminomethyl phosphonate 30 to 60 parts by weight, dimethylformamide 1 to 10 parts by weight, titanium dioxide powder 5 to 15 parts by weight, silicic acid Preparing a first mixture comprising 5 to 15 parts by weight of calcium powder and 5 to 15 parts by weight of LiNO3-MgO mixture;
Preparing a second mixture containing an isocyanate-based curing agent and 10 to 25 parts by weight of potassium octate based on 100 parts by weight of the isocyanate-based curing agent;
Forming urethane foam by adding the second mixture to the first mixture at a weight ratio of 1:0.1 to 0.5 and simultaneously injecting nitrogen gas using a foamer to foam it; and
Heat treating the urethane foam at a temperature range of 60°C to 180°C;
Method for manufacturing flame retardant urethane foam, including.
delete delete delete The method of claim 1, wherein the isocyanate-based curing agent,
Ethylene diisocyanate, methylene diisocyanate, modified methylene diphenyl diisocyanate, toluene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecane diisocyanate, and combinations thereof A method of manufacturing flame-retardant urethane foam, characterized in that it includes at least one selected from the group consisting of.
delete delete The method of claim 1, wherein the first mixture is:
A method of manufacturing flame-retardant urethane foam, characterized in that it additionally includes ammonium phosphate.