JP7048646B2 - Polyurethane foam with excellent fire resistance and its manufacturing method - Google Patents

Description

This application claims the benefit of priority under Korean Patent Application No. 10-2019-0081409 dated 07.05.2019, while all the content disclosed in the literature of the relevant Korean patent application is in this specification. Included as part.

The present invention relates to a polyurethane foam having excellent fire resistance and a method for producing the same.

Polyurethane means a high molecular weight substance containing a urethane bond produced by a polyol and an isocyanate, and is produced by the reaction of the NCO of the isocyanate with the hydroxy group (OH) of the polyol. Generated.

Polyurethane foam is divided into flexible polyurethane foam (Flexible Polyurethane foam) and rigid polyurethane foam (Rigid Polyurethane foam) according to the shape of the cells inside. Flexible polyurethane foams are made with TDI or MDI and a polyether triol with 25-36 hydroxy groups. Flexible polyurethane foam is lightweight, has good elasticity, and has high air permeability due to its open cell structure. Flexible polyurethane foam is commonly applied to products such as clothing, bedding, mattresses or car seats. Rigid polyurethane foams, on the other hand, are made from MDI and polyols with 3-8 functional groups. Rigid polyurethane foam has a fine cell size and a clogged honeycomb-shaped closed-cell structure. The rigid polyurethane foam has excellent mechanical strength and excellent heat insulating properties due to the gas having low thermal conductivity inside the cell. Rigid polyurethane foam can be applied as a heat insulating material.

Conventional rigid polyurethane foams are excellent in mechanical strength and heat insulating properties, but have insufficient flame resistance properties in consideration of the occurrence of a fire, which limits the fields of application.

Korean Patent Publication No. 2013-0004795

The present invention has been devised to solve the above-mentioned problems, and an object of the present invention is to provide a polyurethane foam having excellent fire resistance and a method for producing the same.

The present invention provides a polyurethane foam and a method for producing the same. Specifically, the method for producing a polyurethane foam according to the present invention is as follows.
For 100 parts by weight of a polyol having an average hydroxyl value (OH value) of 150 to 300 mgKOH / g, 1 to 6 parts by weight of a silicone foam stabilizer, 0.1 to 1.5 parts by weight of an amine-based catalyst, and 6 to 55 parts by weight of a phosphorus-based flame retardant. At the stage of mixing the parts to produce a polyol mixture,
The stage of adding the foaming agent to the polyol mixture and
The stage of mixing isocyanate with the polyol mixture containing the foaming agent and controlling the NCO Index to be 450 to 550, and
Including the step of foaming at a foaming pressure of 100 to 140 bar (100 x 10 ⁵ to 140 x 10 ⁵ Pa) .

Here, the phosphorus-based flame retardant includes a first flame retardant containing a halogen atom and a second flame retardant not containing a halogen atom.

In one example, the first phosphorus-based flame retardant is Tris2-chloropropyl phosphate (TCPP), Tris2-chloroethyl phosphate (TCEP), and phosphinyl phosphate alkyl ester. One or more species selected from the group consisting of (Phosphinyl alkylphosphate ester, CR-530).
The second phosphorus flame retardant is selected from the group consisting of Triethyl phosphate (TEP), Tetramethylene bis orthophosphorylurea (TBPU) and Resorcinol bis diphenyl phosphate (RDP). It is more than one kind to be done.

Further, the ratio (M1 / M2) of the content of the first flame retardant (M1) to the content of the second flame retardant (M2) can be controlled in the range of 0.2 to 35.

In another embodiment, the amine-based catalyst is selected from the group consisting of pentamethylene diethylene triamine (PMDETA), dimethylcyclohexylamine (DMCHA) and tetramethylethylene-diamine (TMEDA). One or more species. Isocyanate is a method for producing a polyurethane foam containing one or more selected from the group consisting of diphenylmethane diisocyanate (MDI) and polymethylene polyphenyl polyisocyanate (polymeric MDI).

The polyurethane foam according to the present invention has an apparent density in the range of 259 to 317 kg / m ³ according to ASTM D1622. In addition, the polyurethane foam has a peak heat dissipation (Heat Release Peak) of 65kW / when measuring the heat dissipation rate (Heat Release Rate) by BSS (Boeing Specification Support) 7322Rev.B-FAR (Federal Aviation Regulation) 25.853App.F, Part IV. It is m ² or less, and the total heat release amount (Heat Release Total) is 65 kW ・ min / m ² or less.

In one example, the polyurethane foam has a moisture absorption of 1% (w / w) or less by ASTM D2842, BSS (Boeing Specification Support) 7238 Rev.C-FAR (Federal Aviation Regulation) 25.853 App.F. , Part V smoke density (Smoke Density) is 200 or less.
Further, the polyurethane foam can be applied to aircraft interior materials.

The polyurethane foam and the method for producing the same according to the present invention realize excellent fire resistance without deterioration of mechanical properties, and the polyurethane foam can be applied as an aircraft interior material.

The manufacturing process of the polyurethane foam which concerns on this invention is schematically illustrated.

Hereinafter, the present invention will be described in more detail. Prior to that, the terms and words used herein and in the scope of the claims shall not be construed in a general or lexical sense and the inventor describes his invention in the best possible way. Therefore, it should be interpreted with meanings and concepts that are consistent with the technical ideas of the present invention, based on the principle that the concepts of terms can be properly defined.

The embodiments shown in the present specification and the configurations shown in the drawings and the like are merely specific examples of the present invention, and do not represent all of the technical ideas of the present invention. It must be understood that at the time of this application, there may be various equivalents and variants that can replace them.

The present invention provides a method for producing a polyurethane foam. Specifically, the method for producing a polyurethane foam according to the present invention is as follows.
For 100 parts by weight of a polyol having an average hydroxyl value (OH value) of 150 to 300 mgKOH / g, 1 to 6 parts by weight of a silicone foam stabilizer, 0.1 to 1.5 parts by weight of an amine-based catalyst, and 6 to 55 parts by weight of a phosphorus-based flame retardant. At the stage of mixing the parts to produce a polyol mixture,
The stage of adding the foaming agent to the polyol mixture and
The stage of mixing isocyanate with the polyol mixture containing the foaming agent and controlling the NCO index (Index) to be 450 to 550, and
Including the step of foaming at a foaming pressure of 100-140 bar.

Further, in the present invention, the phosphorus-based flame retardant includes a first flame retardant containing a halogen atom and a second flame retardant not containing a halogen atom.

In the present invention, water (H ₂ O), which is a chemical foaming agent, can be used as a foaming agent, and one or more of HFC-series foaming agents and / or HFO-series foaming agents, which are physical foaming agents, can be used. Provided using a foamed, rigid polyurethane foam (Rigid Polyurethane foam). For example, in the present invention, water can be used as a foaming agent. The content of the foaming agent may vary depending on the field of application of the foam and the required physical properties. In the present invention, 0.1 to 1 part by weight of water is added to 100 parts by weight of the polyol. As a result, the polyurethane foam according to the present invention satisfies the mechanical properties required at the time of application as an aircraft interior material.

In the present invention, the NCO index at the time of manufacturing the polyurethane foam is controlled in the range of 450 to 550, and at the same time, the above two types of flame retardants are used together. It was confirmed that the polyurethane foam produced through this process did not deteriorate in mechanical properties, had excellent flame resistance, and significantly reduced the amount of smoke generated during a fire.

The method for producing a polyurethane foam according to the present invention uses both the first and second phosphorus-based flame retardants. In one example, the first phosphorus-based flame retardants are Tris2-chloropropyl phosphate (TCPP), Tris2-chloroethyl phosphate (TCEP), and phosphinyl phosphate alkyl esters. (Phosphinyl alkyl phosphate ester, CR-530), and the second phosphorus-based flame retardant is Triethyl phosphate (TEP), Tetramethylene bis orthophosphorylurea (TBPU). And one or more of Resorcinol bis diphenyl phosphate (RDP). The total content of the first and second flame retardants is 6 to 55 parts by weight with respect to 100 parts by weight of the polyol. Specifically, the content of the first flame retardant is used in the range of 5 to 35 parts by weight, 10 to 30 parts by weight or 15 to 25 parts by weight, and the remaining flame retardant component is the second flame retardant. use. For example, the first flame retardant is applied at a content ratio of 1.5 times or more that of the second flame retardant.

Further, the amine-based catalyst can be used without any special limitation as long as it has catalytic activity, for example, pentamethylenediethylene-triamine (PMDETA), dimethylcyclohexylamine (DMCHA) and tetramethyl. Contains one or more of Tetramethylethylenediamine (TMEDA).

In one example, the isocyanate comprises one or more of diphenylmethane diisocyanate (MDI) and polymethylene polyphenyl polyisocyanate (polymeric MDI). By controlling the contents of MDI and PMDI, the NCO index of the polyol mixture can be effectively controlled.

Hereinafter, the present invention will be described in more detail with reference to the drawings and examples described in the present specification. However, the configurations shown in the examples and drawings are merely specific examples of the present invention, and do not represent all of the technical ideas of the present invention. Therefore, it must be understood that at the time of this application, there may be various equivalents and variants that can replace them.

First, referring to FIG. 1, in the polyurethane foam according to the present invention, a step of synthesizing a polyol (S1) and a step of mixing the synthesized polyol with a foam stabilizer, a catalyst and a flame retardant to form a polyol mixture (S2). , The stage of adding a foaming agent to the polyol mixture (S3), the stage of adding an isocyanate component to the polyol mixture to control the NCO index (S4), and the stage of foaming the polyol mixture through an extruder (S5). Can be manufactured through.

In the present invention, the description will be divided into stages S1 to S5, but this is for the sake of simplicity. For example, the steps S2-S4 can be performed in whole or in part simultaneously or sequentially, and in some cases some of the order can be changed, which all belong to the scope of the invention. Should be interpreted as a thing.

The polyol according to the present invention is characterized by having an average hydroxyl value (OH value) of 150 to 300 mgKOH / g. The average hydroxyl group of the polyol is controlled by the NCO index (Index) by limiting the average hydroxyl group of the polyol as a component for advancing the polymerization reaction with the isocyanate group of the isocyanate compound contained in the polyurethane foam composition. obtain. As a result, it is possible to stably secure mechanical strength such as compressive strength and peel strength of polyurethane foam, and to improve flame resistance such as flame retardancy and heat release rate.

The process of synthesizing a polyol can be carried out in various ways by known methods. In the present invention, the average hydroxyl value at the time of synthesizing a polyol is controlled within a specific range. When the average hydroxyl group of the polyol is less than 150 mgKOH / g, the flame resistance property of the produced polyurethane foam can be ensured by increasing the NCO index, but there is a problem that the mechanical strength of the polyurethane foam is lowered. On the other hand, when the average hydroxyl group of the polyol exceeds 300 mgKOH / g, there is a problem that the flame resistance performance of the produced polyurethane foam is lowered due to the decrease of the NCO index.

In one example, a polyol refers to an alcohol having at least one hydroxyl group, which can be in the form of a diol, triol, tetrol or more hydroxy groups and is poly. It can be an ether polyol or a polyester polyol. According to the present invention, a large number of polyols can be mixed to form a synthetic polyol. Specifically, a polyol obtained by adding propylene oxide and ethylene oxide to amine, a polyol obtained by adding propylene oxide and ethylene oxide to toluenediamine, and a condensation reaction of diethylene glycol and dipropylene glycol with terephthalic acid and phthalic acid. Obtained polyol, polyol obtained by condensation reaction of diethylene glycol and dipropylene glycol with phthalic anhydride and adipic acid, polyol obtained by adding propylene oxide and ethylene oxide to sorbitol, and propylene oxide and ethylene oxide added to ethylenediamine. Synthetic polyols can be produced by selecting at least 5 polyols from the obtained polyols and polyols composed of polyols obtained by adding propylene oxide and ethylene oxide to glycerin. The method for obtaining each polyol can be made by a reaction known in the art, and the present invention is not limited thereto.

When the polyol to be synthesized is selected from the polyol group presented above, 3 to 15 parts by weight of the polyol obtained by adding propylene oxide and methylene oxide to the amine to form the synthetic polyol, toluene. 5 to 30 parts by weight of a polyol obtained by adding propylene oxide and methylene oxide of diamine, 10 to 60 parts by weight of a polyol obtained by a condensation reaction of diethylene glycol and dipropylene glycol with terephthalic acid and phthalic acid, phthalic anhydride and adipic acid 10 to 60 parts by weight of a polyol obtained by the condensation reaction of diethylene glycol and dipropylene glycol, 10 to 60 parts by weight of a polyol obtained by adding propylene oxide and ethylene oxide to sorbitol, and propylene oxide and ethylene oxide added to ethylenediamine. 2 to 25 parts by weight of the obtained polyol and 5 to 15 parts by weight of the polyol obtained by adding propylene oxide and ethylene oxide to glycerin can be mixed.

The synthesized polyol can be mixed with a defoaming agent, a catalyst, a flame retardant, etc. to be made as a polyol mixture. Defoaming agents (surfactants) reduce surface tension to improve mixability and adjust the cell structure of the foam so that the size of the generated bubbles is uniform to impart stability. As a silicone defoaming agent (silicone surfactant), a silicone foam stabilizer can be used. As the defoaming agent, 1 to 6 parts by weight, specifically 1.5 to 3.5 or 1.5 to 3 parts by weight, is used with respect to 100 parts by weight of the polyol.

If necessary, the catalyst of the polyol can be mixed to shorten the reaction time. As the catalyst, an amine or a metal catalyst is used. For example, in the present invention, pentamethylenediethylenetriamine (PMDETA) is used as a catalyst. The content of the catalyst is 0.1 to 1.5 parts by weight with respect to 100 parts by weight of the polyol. Specifically, the catalyst is charged with 0.5 to 1.5 or 0.8 to 1.2 parts by weight with respect to 100 parts by weight of the polyol.

Further, in the present invention, a phosphorus-based flame retardant is mixed with the polyol. As the phosphorus-based flame retardant, two different phosphorus-based flame retardants are mixed and used. For example, the phosphorus-based flame retardant uses a mixture of tris2-chloropropyl phosphate (TCPP, the first flame retardant) and triethyl phosphate (TEP, the second flame retardant). When two types of phosphorus-based flame retardants are mixed and used as described above, flame resistance characteristics such as heat dissipation rate and smoke density are significantly improved, and mechanical properties such as compressive strength are also improved to a certain level. It was confirmed experimentally.

The total content of the flame retardant can be controlled in the range of 6 to 55 parts by weight, 10 to 50 parts by weight or 30 to 45 parts by weight with respect to 100 parts by weight of the polyol. Specifically, the content of the first flame retardant shall be in the range of 5 to 35 parts by weight, 10 to 30 parts by weight or 15 to 25 parts by weight, and the content of the remaining flame retardant shall be the second flame retardant. .. In one example, the content of the first flame retardant can be controlled higher than the content of the second flame retardant. For example, the ratio (M1: M2) of the content of the first flame retardant (M1) to the content of the second flame retardant (M2) is in the range of 1.5: 1 to 5: 1, or 2: 1 to 3. : Can be controlled in the range of 1. When the ratio of the contents of the first and second flame retardants is out of the above range, the effect of improving the physical properties of the polyurethane foam is significantly reduced.

The polyol mixture undergoes extrusion foaming with a foaming agent added. As the foaming agent, water (H ₂ O), which is a chemical foaming agent, can be used, and one or more of the HFC-series foaming agents and / or the HFO-series foaming agents, which are physical foaming agents, can be used. Can be mixed and used. For example, water can be used as a foaming agent. When water is used as the foaming agent, it is added in the range of 0.1 to 1.0 part by weight or 0.2 to 0.7 part by weight with respect to 100 parts by weight of the polyol.

The polyol mixture containing the foaming agent can be charged into the foaming machine together with the isocyanate component. As the isocyanate component, one or more of diphenylmethane diisocyanate (MDI) and polymethylene polyphenyl polyisocyanate (polymeric MDI) can be used. Generally, the equivalent ratio of isocyanate and a polyol having a hydroxy group is called an NCO index (Index). The NCO index affects the degree of cross-linking of urethane foam, mechanical strength, toughness and flexibility of urethane foam. The NCO index of the polyol mixture according to the present invention is in the range of 450 to 550, specifically in the range of 450 to 520, 480 to 550, or 470 to 530.

Next, foaming is performed while controlling the pressure of the foaming machine at 100 to 140 bar to produce polyurethane foam. A fiber-reinforced polyurethane foam can be produced by a method of continuously impregnating a fiber such as a natural fiber, a synthetic fiber, or a glass fiber with a polyol mixture and an isocyanate, if necessary.

The present invention also provides a polyurethane foam produced by the method described above. The present invention relates to a rigid polyurethane foam (Rigid Polyurethane foam), and particularly provides a polyurethane foam applicable as an interior material of an aircraft. In order to be applied as an interior material for aircraft, it must meet various standards required by airline companies. For that purpose, it is necessary to satisfy a higher level of mechanical properties and to satisfy flame resistance characteristics such as flame and smoke density in preparation for a fire.

In the present invention, the NCO index is controlled in the range of 450 to 550 during the production of polyurethane foam, and at the same time, the above-mentioned two flame retardants are used together. As a result, it was confirmed that the produced polyurethane foam has excellent flame resistance and the amount of smoke generated in the event of a fire is significantly reduced.

In one embodiment, the polyurethane foam has an apparent density in the range of 259 to 317 kg / m ³ according to ASTM D1622. In addition, the polyurethane foam has a peak heat dissipation (Heat Release Peak) of 65kW when measuring the heat dissipation rate (Heat Release Rate) by BSS (Boeing Specification Support) 7322 Rev.B-FAR (Federal Aviation Regulation) 25.853 App.F, Part IV. It is / m ² or less, and the total heat release amount (Heat Release Total) is 65 kW.min / m ² or less. By satisfying the numerical ranges for the density and heat dissipation rate, it was confirmed that the polyurethane foam according to the present invention has excellent mechanical strength and excellent flame resistance.

In another embodiment, the polyurethane foam has a moisture absorption rate of 1% (w / w) or less according to ASTM D2842. And the smoke density (Smoke Density) by BSS (Boeing Specification Support) 7238 Rev.C-FAR (Federal Aviation Regulation) 25.853 App.F, Part V is 200 or less. The polyurethane foam according to the present invention has excellent moisture resistance, and it can be seen from experiments on smoke density assuming a fire that it has excellent fire resistance.

The polyurethane foam according to the present invention realizes excellent mechanical properties and fire resistance at the same time, and can be widely used as interior / exterior materials for buildings, interior / exterior materials for cars, interior materials for aircraft, and the like. In particular, the polyurethane foam is preferably applicable for aircraft interior materials.

Hereinafter, the present invention will be described in more detail through examples and the like, but the scope of the present invention is not limited thereto.

<Examples 1 to 4>
Niax Silicone L-6124 1-6 parts by weight, which is a silicone foam stabilizer, in 100 parts by weight of a synthetic polyol with an average water acid value (OH value) of 150 to 300 mgKOH / g, and Pentamethylenediethylene-triamine (PMDETA) as a catalyst. 0.1 to 1.5 parts by weight, 5 to 35 parts by weight of Tris2-chloropropyl phosphate (TCPP), which is a flame retardant, and 1 to 20 parts by weight of Triethyl phosphate (TEP) are mixed and polyol. A mixture was produced.

0.1 to 1.0 part by weight of water was added as a foaming agent to the produced polyol mixture. MDI or PMDI was added to the mixture of the polyol mixture and water in a foaming machine to control the NCO index (Index) to be 450 to 550.
Next, the foaming pressure of the foaming machine was set to 100 to 140 bar, and the polyurethane foam was manufactured while maintaining the foaming pressure.

The content and conditions of the components for each example are shown in Table 1 below.

<Comparative examples 1 to 4>
Polyurethane foam was produced in the same manner as in Example 1, but the content and conditions of each component were adjusted as shown in Table 2 below.

<Experimental example>
The physical characteristics of the items shown in Table 3 below were evaluated for each polyurethane foam test piece produced in Examples and Comparative Examples.

The evaluation results for each item are shown in Table 4 below.

With reference to the results in Table 4, it can be seen that the foam test piece according to Example 1 is excellent not only in mechanical properties but also in flame resistance. On the other hand, it can be seen that the foam test pieces of Comparative Examples 1 to 3 are not as good in physical properties as the foam test pieces of Example 1 in the evaluation of the "heat dissipation rate" item.

Specifically, the foam test pieces of Comparative Examples 1 and 2 having a low NCO index had the results of peak heat dissipation (Heat Release Peak) and total heat dissipation (Heat Release Total), which are items of heat dissipation rate, as compared with Example 1. It was found that the flame resistance performance of urethane foam was not very good because it was displayed extremely high. Moreover, it was shown that the foam test piece of Comparative Example 3 did not have a good evaluation result for the heat dissipation rate, and in particular, the numerical value of the item of "smoke density" exceeded 2.5 times as compared with that of Example 1.

In the present invention, the NCO index is controlled in the range of 450 to 550 during the production of polyurethane foam, and two types of flame retardants are used in the appropriate range at the same time. As a result, the mechanical properties are not deteriorated and the flame resistance is excellent. , It is possible to provide a polyurethane foam in which the amount of smoke generated during a fire is significantly reduced.

The polyurethane foam according to the present invention and the method for producing the same realize excellent fire resistance characteristics without deterioration of mechanical properties. The polyurethane foam can be applied to aircraft interior materials.

S1: Synthesis of polyol
S2: Production of polyol mixture
S3: Addition of foaming agent
S4: Addition of isocyanate
S5: Form formation

Claims (3)

For 100 parts by weight of a polyol having an average hydroxyl value (OH value) of 150 to 300 mgKOH / g, 1 to 6 parts by weight of a silicone foam stabilizer, 0.1 to 1.5 parts by weight of an amine-based catalyst, and 6 to 55 parts by weight of a phosphorus-based flame retardant. At the stage of mixing the parts to produce a polyol mixture,
At the stage of adding 0.1 to 1.0 parts by mass of the foaming agent to 100 parts by weight of the polyol , and
The stage of mixing isocyanate with the polyol mixture containing the foaming agent and controlling the NCO index (Index) to be 450 to 550, and
Including the stage of manufacturing polyurethane foam by foaming while controlling the foaming pressure with a foaming machine at a foaming pressure of 100 × 10 ⁵ to 140 × 10 ⁵ Pa .
The phosphorus-based flame retardant contains a first flame retardant containing a halogen atom and a second flame retardant not containing a halogen atom .
The first phosphorus-based flame retardant is Tris2-chloropropyl phosphate (TCPP), Tris2-chloroethyl phosphate (TCEP), and Phosphinyl alkyl phosphate ester. , CR-530), one or more selected from the group consisting of
The second phosphorus flame retardant consists of the group consisting of Triethyl phosphate (TEP), Tetramethylene bis orthophosphoryl urea (TBPU) and Resorcinol bis diphenyl phosphate (RDP). One or more selected
A method for producing a polyurethane foam, wherein the ratio (M1 / M2) of the content of the first flame retardant (M1) to the content of the second flame retardant (M2) is in the range of 0.2 to 35 . The amine-based catalyst is characterized in that it is at least one selected from the group consisting of pentamethylenediethylene-triamine (PMDETA), dimethylcyclohexylamine (DMCHA) and tetramethylethylenediamine (TMEDA). The method for producing a polyurethane foam according to claim 1. The method for producing a polyurethane foam according to claim 1, wherein the isocyanate comprises at least one selected from the group consisting of diphenylmethane diisocyanate (MDI) and polymethylene polyphenyl polyisocyanate (polymeric MDI).

Images