Foamed urethane resin composition

Abstract

To provide a foamable urethane resin composition for producing a polyurethane foam having a property of not easily shrinking and not easily spreading the fire.SOLUTION: Provided is a foamable urethane resin composition, which is a foamable urethane resin composition containing a polyol compound, a polyisocyanate compound, a flame retardant liquid at room temperature, a foam-shaping agent, a foaming agent, and a catalyst, and in which the foamable urethane resin composition contains a resin fine particle-containing polyol, and the sinking distance of a steel ball in the hot steel ball evaluation of a polyurethane foam made of said foamable urethane resin composition is 10 mm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a foamed urethane resin composition. [Background technology]

[0002] Polyurethane foam is used in practical applications for insulation and condensation prevention in ceilings, roofs, and walls of buildings such as apartment buildings, detached houses, and commercial buildings, taking advantage of its excellent heat insulation properties. Although polyurethane foam is lightweight, it is flammable because it is an organic material. To improve this, polyurethane foam with enhanced flame retardancy is used by incorporating flame retardants into the foam. For example, Patent Document 1 describes a flame-retardant polyurethane foam obtained using ammonium polyphosphate, a urea derivative, a polyol, and an isocyanate, characterized in that the flame-retardant polyurethane foam is obtained by using ammonium polyphosphate in the range of 5 to 150 parts by weight and a urea derivative in the range of 0.001 to 15 parts by weight per 100 parts by weight of polyol. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2015-151524 [Overview of the project] [Problems that the invention aims to solve]

[0004] In recent years, there have been a relatively large number of reports of fires caused by polyurethane foam used as insulation in buildings. To address this problem, there is a need for the development of polyurethane foam that not only possesses excellent flame retardancy but also has properties that prevent fire from spreading easily once it starts. On the other hand, polyurethane foam has the drawback of being prone to shrinkage depending on the usage environment. When it shrinks, it affects the foam's strength, thermal conductivity, and other properties, making long-term use difficult. Therefore, the object of the present invention is to provide a foamable urethane resin composition for producing a polyurethane foam that is resistant to shrinkage and resistant to flame spreading. [Means for solving the problem]

[0005] As a result of diligent research, the inventors have found that the above problems can be solved by a foaming urethane resin composition comprising a polyol compound and a polyisocyanate compound, wherein the polyol compound comprises a polyol containing resin fine particles, and exhibits specific values ​​in hot steel ball evaluation, thereby completing the present invention. That is, the present invention provides the following [1] to

[14] . [1] A foamable urethane resin composition comprising a polyol compound, a polyisocyanate compound, a flame retardant that is liquid at room temperature, a blowing agent, and a catalyst, wherein the polyol compound comprises a polyol containing resin fine particles, and the sinking distance of the steel ball in the following hot steel ball evaluation of the polyurethane foam made from the foamable urethane resin composition is 10 mm or less. (Evaluation of hot steel balls) (1) Cut the polyurethane foam into cubes with sides of 50 mm to make test specimens. (2) Place a wire mesh 30 mm from the burner opening of a Bunsen burner (outer flame length 70 mm), place a steel ball with a diameter of 10.0 mm and a weight of 4.15 g on the wire mesh, and heat for at least 5 minutes until the entire steel ball turns red, bringing the steel ball temperature to 630°C. (3) In a 23°C atmosphere, immediately place the steel ball heated in (2) above on the center of the upper part of the test specimen in (1) above and leave it until the steel ball has fully sunk in. Then, cut the cross section of the sufficiently cooled test specimen and measure the sinking distance and melting diameter distance of the steel ball. [2] The foamed urethane resin composition according to [1] above, wherein the sinking distance of the steel ball in the hot steel ball evaluation is 5 mm or less and the melting diameter distance is 15 mm or less. [3] The polyurethane foam made from the foaming urethane resin composition was subjected to a test in accordance with the ISO-5660 test method, with a radiant thermal intensity of 50 kW / m². 2The total heat output when heated for 5 minutes was 8 MJ / m². 2 The foamed urethane resin composition described in [1] or [2] above, which is as follows: [4] The polyurethane foam made from the foaming urethane resin composition was subjected to a test in accordance with the ISO-5660 test method, with a radiant thermal intensity of 50 kW / m². 2 The maximum heating rate when heated for 5 minutes was 200 kW / m². 2 The foamed urethane resin composition described in any of the above [1] to [3], which is as follows: [5] The foaming urethane resin composition according to any one of [1] to [4] above, wherein the resin fine particle-containing polyol is an amine-based polyether polyol containing resin fine particles. [6] The foaming urethane resin composition according to any one of [1] to [5] above, wherein the resin fine particles are polymers of at least one monomer selected from the group consisting of acrylonitrile, methacrylonitrile, fluorine-containing acrylonitrile, α-ethylacrylonitrile, styrene, vinyl acetate, and acrylic monomers. [7] The foamable urethane resin composition according to any one of [1] to [6] above, comprising a polyol composition containing a polyol compound, a flame retardant that is liquid at room temperature, a blowing agent, and a catalyst, and a polyisocyanate compound, wherein the content of the resin fine particles on a basis of the total amount of the polyol composition is 0.01% by mass or more. [8] The foamed urethane resin composition according to any one of [1] to [7] above, wherein the polyol compound contains a phthalic acid-based polyester polyol. [9] The foaming urethane resin composition according to [8] above, wherein the weight ratio of the phthalate-based polyester polyol to the resin fine particle-containing polyol (phthalate-based polyester polyol / resin fine particle-containing polyol) is 95 / 5 to 55 / 45.

[10] The foaming urethane resin composition according to any one of [1] to [9] above, wherein the foaming agent contains water, and the water content is 1.5 parts by mass or less per 100 parts by mass of the polyol compound.

[11] The foaming urethane resin composition according to any one of [1] to

[10] above, wherein the foaming agent comprises a hydrofluoroolefin.

[12] The foaming urethane resin composition according to any one of [1] to

[11] above, wherein the catalyst contains a trimerizing catalyst.

[13] A foaming urethane resin composition according to any of [1] to

[12] above, wherein the isocyanate index is 150 to 700.

[14] A foaming urethane resin composition according to any one of [1] to

[13] above, which substantially does not contain an inorganic filler. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a foamable urethane resin composition that can form a polyurethane foam that is resistant to shrinkage and has properties that make it difficult for fire to spread in the event of a fire. [Modes for carrying out the invention]

[0007] [Foamed urethane resin composition] The foamable urethane resin composition of the present invention is a foamable urethane resin composition comprising a polyol compound, a polyisocyanate compound, a flame retardant that is liquid at room temperature, a blowing agent, and a catalyst, wherein the polyol compound comprises a polyol containing resin fine particles, and the polyurethane foam made from the foamable urethane resin composition exhibits a steel ball sinking distance of 10 mm or less in the following hot steel ball evaluation. (Evaluation of hot steel balls) (1) Cut the polyurethane foam into cubes with sides of 50 mm to make test specimens. (2) Place a wire mesh at a point 30 mm from the burner mouth of a Bunsen burner (outer flame length 70 mm), place a steel ball with a diameter of 10.0 mm and a weight of 4.15 g on the wire mesh, and heat for at least 5 minutes until the entire steel ball changes to red, and set the steel ball temperature to 630 °C. The steel ball temperature was measured by moving the steel ball heated as described above from the wire mesh to another stand that does not affect the radiation temperature measurement. The steel ball temperature was measured using a radiation thermometer (manufactured by Keyence: FT-H40K), and the evaluated temperature (630 °C) was the value obtained by dividing the display value of the radiation thermometer by 0.45 with the radiation coefficient of the used steel ball being 0.45. Note that new steel balls were used. (3) Immediately place the steel ball heated in (2) above at the center of the upper part of the test piece in an atmosphere of 23 °C, and leave it until the sinking of the steel ball is completed. Then, cut the cross-section of the sufficiently cooled test piece and measure the sinking distance and melting diameter distance of the steel ball. In this hot steel ball evaluation, the time from heating the steel ball to measuring the temperature is within 1 second, and immediately after measuring the temperature, the steel ball is placed on the test piece. Therefore, the above steel ball temperature (630 °C) can be regarded as the temperature of the steel ball when it is placed on the test piece.

[0008] In the above hot steel ball evaluation, regarding the diameter and weight of the steel ball, if the diameter is 10.0 ± 0.5 mm, the weight is 4.15 ± 0.3 g, and the steel ball temperature is within the range of 600 - 650 °C measured by the radiation thermometer, by setting other conditions as described above, an equivalent hot steel ball evaluation can be obtained, so it may be carried out within such ranges of diameter, weight, and steel ball temperature. Also, the outer flame length means the length of the flame in the directly upward direction from the center of the burner mouth.

[0009] By setting the sinking distance and melting diameter distance of the steel ball in the hot steel ball evaluation of the polyurethane foam made of the foamed urethane resin composition of the present invention within the above-specified ranges, the polyurethane foam can be made difficult to spread when exposed to a fire or the like.

[0010] The polyurethane foam made of the foaming urethane resin composition of the present invention has a penetration distance of the steel ball in the hot steel ball evaluation of 10 mm or less. When the penetration distance of the steel ball exceeds 10 mm, the polyurethane foam is likely to spread when exposed to a fire or the like, and it becomes difficult to effectively prevent the spread of fire. From the viewpoint of effectively preventing the spread of fire, the penetration distance of the steel ball is preferably 5 mm or less, more preferably 3 mm or less, and even more preferably 0 mm.

[0011] The polyurethane foam made of the foaming urethane resin composition of the present invention preferably has a molten diameter distance in the hot steel ball evaluation of 15 mm or less. When the molten diameter distance is 15 mm or less, the polyurethane foam is less likely to spread when exposed to a fire or the like, and the spread of fire can be effectively prevented. From the viewpoint of effectively preventing the spread of fire, the molten diameter distance is preferably 14 mm or less, more preferably 13 mm or less, and even more preferably 12 mm or less. Note that the molten diameter distance is 0 mm or more.

[0012] The penetration distance of the steel ball and the molten diameter distance can be adjusted to desired values by adjusting the type of polyol compound, the water content, etc. contained in the foaming urethane resin composition.

[0013] In the hot steel ball evaluation, in the test piece, a cavity is formed from the upper surface of the test piece to the inside due to the penetration of the steel ball. The penetration distance of the steel ball means the maximum distance of the cavity in the direction perpendicular to the upper surface of the test piece (the part that retains its shape although it changes color due to heat is not the target). Also, the molten diameter distance is the diameter of the hole formed by the heated steel ball on the upper surface of the test piece. Note that if the shape of the hole formed on the upper surface of the test piece is circular, it means the diameter of the circle, and if the shape of the hole is elliptical, it means the major axis. Also, if the shape of the hole is other than circular and elliptical, the maximum distance between any two points of the shape is taken as the diameter of the hole. Note that when the test piece does not melt and no cavity occurs on the upper surface, the diameter of the carbonized or discolored part is measured in the same way.

[0014] In addition, for the polyurethane foam in the hot steel ball evaluation, use the one prepared under the conditions described in the examples.

[0015] (Total heat release) The polyurethane foam made of the foaming urethane resin composition of the present invention is heated at a radiant heat intensity of 50 kW / m 2 for 5 minutes in accordance with the test method of ISO-5660, and the total heat release is preferably 8 MJ / m 2 or less. By having a total heat release of 8 MJ / m 2 or less, the polyurethane foam made of the foaming urethane resin composition of the present invention has a predetermined flame retardancy. By having a predetermined flame retardancy and the steel ball sinking distance and the molten diameter distance being below a certain value as described above, it becomes a polyurethane foam having flame retardancy and the property of not spreading by burning, and can more effectively prevent the spread of fire. From the viewpoint of further improving the flame retardancy of the polyurethane foam, the above total heat release is preferably 7.8 MJ / m 2 or less, and more preferably 7.5 MJ / m 2 or less.

[0016] (Maximum heat release rate) The polyurethane foam made of the foaming urethane resin composition of the present invention is heated at a radiant heat intensity of 50 kW / m 2 for 5 minutes in accordance with the test method of ISO-5660, and the maximum heat release rate is preferably 200 kW / m 2 or less. By having a maximum heat release rate of 200 kW / m 2 or less, the polyurethane foam made of the foaming urethane resin composition of the present invention has a predetermined flame retardancy. Also, by adjusting both the maximum heat release rate and the total heat release as described above, the flame retardancy is further improved. By having a predetermined flame retardancy and the steel ball sinking distance and the molten diameter distance being below a certain value as described above, it becomes a polyurethane foam having flame retardancy and the property of not spreading by burning, and can more effectively prevent the spread of fire. From the perspective of further improving the flame retardancy of polyurethane foam, the above maximum heat generation rate is set to 150 kW / m². 2 Preferably, it is 130 kW / m 2 The following is more preferable:

[0017] The total calorific value and maximum heating rate mentioned above are obtained by cone calorimeter testing and can be measured in detail by the method described in the examples. Furthermore, during the cone calorimeter test described above, it is preferable that the polyurethane foam used in the test has sufficient dimensional stability to avoid contact with the spark igniter of the cone calorimeter.

[0018] (Polyol compounds) The polyol compound contained in the foamable urethane resin composition of the present invention includes a polyol containing resin microparticles. This makes it easier to prevent shrinkage of the polyurethane foam made from the foamable urethane resin composition during use. Furthermore, it makes it easier to suppress expansion in the cone calorie test and improves dimensional stability at high temperatures. The reason for this is not clear, but it is presumed that the proportion of open cells in the foam increases by using the polyol containing resin microparticles. When the foam is observed with a scanning electron microscope (SEM), holes that appear to have been destroyed by the microparticles can be observed. The resin fine particles are not particularly limited, but are preferably polymers of at least one monomer selected from the group consisting of acrylonitrile, methacrylonitrile, fluorine-containing acrylonitrile, α-ethylacrylonitrile, styrene, vinyl acetate, and acrylic monomers. Among these, polymers of at least one monomer selected from the group consisting of acrylonitrile, methacrylonitrile, styrene, and fluorine-containing acrylonitrile are preferred, with polymers of acrylonitrile being preferred.

[0019] Examples of acrylic monomers include (meth)acrylates, such as alkyl (meth)acrylates including methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, and n-decyl (meth)acrylate. In addition, hydroxyl group-containing (meth)acrylates such as hydroxyalkyl (meth)acrylate can also be used. Furthermore, acrylic monomers may also be fluorine-containing monomers. Examples of fluorine-containing monomers include monomers such as the above-mentioned alkyl (meth)acrylates and hydroxyl group-containing (meth)acrylates, in which one or more hydrogen atoms constituting the monomer are substituted with fluorine atoms. Furthermore, acrylates and methacrylates, or both, are collectively referred to as (meth)acrylates.

[0020] The content of the resin fine particles in the total polyol composition is preferably 0.01% by mass or more, and more preferably 0.02% by mass or more. When the content of the resin fine particles is above these lower limits, it becomes easier to suppress the shrinkage of the polyurethane foam. The content of the resin fine particles in the total polyol composition is preferably 5% by mass or less, and more preferably 1% by mass or less. The foamed urethane resin composition of the present invention preferably comprises a polyol composition containing a polyol compound, a flame retardant that is liquid at room temperature, a blowing agent, and a catalyst, and a polyisocyanate compound, and is produced by mixing the polyol composition and the polyisocyanate compound.

[0021] The content of resin fine particle-containing polyols, based on the total amount of polyol compounds, is preferably 3 to 40% by mass, more preferably 4 to 35% by mass, even more preferably 5 to 30% by mass, and even more preferably 8 to 30% by mass. If the content of resin fine particle-containing polyols is above these lower limits, it becomes easier to suppress the shrinkage of the polyurethane foam, and if it is below these upper limits, it becomes easier to improve the flame-retardant properties of the polyurethane foam.

[0022] The type of polyol containing resin microparticles is not particularly limited, and for example, the polyols described later can be used. Among these, from the viewpoint of suppressing shrinkage of the polyurethane foam while obtaining appropriate reactivity, polyether polyols containing resin microparticles are preferred, and amine-based polyether polyols containing resin microparticles are more preferred. As for the amine-based polyether polyols, for example, tolylenediamine-based polyether polyols (TDA-based polyether polyols) and Mannich-based polyether polyols described later are preferred. Furthermore, from a similar viewpoint, the hydroxyl value of the polyether polyol containing resin fine particles is preferably 250 to 550 mg KOH / g, more preferably 300 to 500 mg KOH / g. In addition, the number of functional groups (number of hydroxyl groups) of the polyether polyol containing resin fine particles is preferably 2 to 4. The hydroxyl value is measured in accordance with JIS K1557-1:2007.

[0023] Polyols containing resin microparticles can be produced by known methods. Examples include adding and mixing the resin fine powder obtained by crushing a resin produced by a bulk polymerization method or a solution polymerization method into microparticles and classifying it as needed, to a polyol; adding an emulsion containing resin microparticles obtained by an emulsion polymerization method directly; and dissolving or dispersing a monomer in a polyol, adding a radical polymerization initiator such as AIBN or BPO, heating, and polymerizing to produce a polyol containing resin microparticles. Among these, the method of forming resin microparticles by polymerization in a polyol is most preferred because the particles are less likely to settle even after being left for a long period of time, and a stable polyol composition can be obtained.

[0024] The following describes polyether polyols, which may be the same as the polyether polyols containing resin microparticles described above, or they may be polyether polyols that do not contain resin microparticles.

[0025] <Polyether polyol> Polyether polyols are polyoxyalkylene polyols obtained by ring-opening addition polymerization of alkylene oxide to an initiator having two or more active hydrogen atoms. Examples of initiators include aliphatic polyhydric alcohols (e.g., glycols such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexylene glycol, and cyclohexanedimethanol; triols such as trimethylolpropane and glycerin; tetrafunctional alcohols such as pentaerythritol; sugars such as sucrose and sorbitol); aliphatic amines (e.g., alkylenediamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, and neopentyldiamine; alkanolamines such as monoethanolamine and diethanolamine); and aromatic amines (e.g., aniline, tolylenediamine, xylylenediamine, diphenylmethanediamine, Mannich condensates, etc.). These may be used individually or in combination of two or more.

[0026] As for the polyether polyol, from the viewpoint of improving the flame retardancy of polyurethane foam, amine-based polyether polyols such as tolylenediamine-based polyether polyols and Mannich-based polyether polyols, sucrose-based polyether polyols, and sorbitol-based polyether polyols are preferred. The above-mentioned tolylenediamine-based polyether polyols refer to polyether polyols obtained using tolylenediamine as an initiator. The same applies to sucrose-based polyether polyols and sorbitol-based polyether polyols. The above-mentioned Mannich-type polyether polyols are obtained using the Mannich reaction and are Mannich condensates having two or more hydroxyl groups in the molecule, or polyether polyols obtained by adding alkylene oxide to such Mannich condensates. More specifically, they are Mannich condensates obtained by the Mannich reaction of at least one of phenol and its alkyl-substituted derivatives, formaldehyde and alkanolamines, or polyether polyols obtained by ring-opening addition polymerization of these compounds with at least one of ethylene oxide and propylene oxide.

[0027] The hydroxyl value of the polyether polyol is preferably 200 to 1,000 mgKOH / g, and more preferably 300 to 600 mgKOH / g. The hydroxyl value is measured in accordance with JIS K1557-1:2007.

[0028] <Polyester Polyol> The polyol compound contained in the foamed urethane resin composition of the present invention preferably contains a polyester polyol. Polyester polyols include aromatic polyester polyols and aliphatic polyester polyols, but when considering the flame retardancy of the resulting polyurethane foam, it is preferable to use aromatic polyester polyols. Aromatic polyester polyols are preferably condensates of aromatic dicarboxylic acids such as o-phthalic acid (phthalic acid), m-phthalic acid (isophthalic acid), p-phthalic acid (terephthalic acid), and naphthalenedicarboxylic acid with glycols. In particular, from the viewpoint of improving the flame retardancy of the polyurethane foam, reducing the values ​​of the steel ball sinking distance and melting diameter distance mentioned above, and improving the performance of preventing the spread of flame, it is preferable that the polyol compound includes phthalic acid-based polyester polyols, which are condensates of phthalic acid and glycol, and more preferably includes p-phthalic acid-based polyester polyols, which are condensates of p-phthalic acid and glycol. While the glycol is not particularly limited, it is preferable to use a low molecular weight aliphatic glycol known as a component of polyester polyols, such as ethylene glycol, propylene glycol, diethylene glycol, or triethylene glycol.

[0029] From the viewpoint of reducing the steel ball sinking distance and melting diameter distance mentioned above and improving the performance of preventing the spread of fire, the content of phthalic acid-based polyester polyol on a basis of the total amount of polyol components is preferably 60 to 97% by mass, and more preferably 65 to 95% by mass.

[0030] In the present invention, from the viewpoint of obtaining a polyurethane foam that is less prone to shrinkage and less prone to flame spreading, the polyol compound contained in the foamable urethane resin composition preferably includes a resin fine particle-containing polyol and a phthalate-based polyester polyol. Here, the weight ratio of the phthalate-based polyester polyol to the resin fine particle-containing polyol (phthalate-based polyester polyol / resin fine particle-containing polyol) is preferably 95 / 5 to 55 / 45, and more preferably 90 / 10 to 60 / 40.

[0031] The hydroxyl value of the polyester polyol is not particularly limited, but from the viewpoint of enhancing the flame-retardant properties of the polyurethane foam, it is preferably 100 to 400 mg KOH / g, and more preferably 150 to 350 mg KOH / g.

[0032] (Polyisocyanate compounds) As the polyisocyanate compound contained in the foamable urethane resin composition of the present invention, various polyisocyanate compounds such as aromatic, alicyclic, and aliphatic compounds having two or more isocyanate groups can be used. Preferably, liquid diphenylmethane diisocyanate (MDI) is used due to its ease of handling, rapid reaction, excellent physical properties of the resulting polyurethane foam, and low cost. Examples of liquid MDI include crude MDI (also called polymeric MDI). Specific commercially available liquid MDI products include "44V-10" and "44V-20" (manufactured by Sumika Covestro Urethane Co., Ltd.) and "Millionate MR-200" (Nippon Polyurethane Industry Co., Ltd.). Alternatively, uretonimine-containing MDI (for example, "Millionate MTL": manufactured by Nippon Polyurethane Industry Co., Ltd. as a commercially available product) may also be used. In addition to liquid MDI, other polyisocyanate compounds may be used in combination, and any polyisocyanate compound known in the field of polyurethanes can be used without limitation.

[0033] The isocyanate index range of the foamed urethane resin composition of the present invention is preferably 150 to 700, more preferably 200 to 650, and even more preferably 250 to 600. Having an isocyanate index within this range makes it easier to adjust the sinking distance and melting diameter distance of the steel ball in the hot steel ball evaluation described above to a desired range. The isocyanate index (INDEX) is calculated using the following method.

[0034] INDEX = Equivalents of isocyanate ÷ (Equivalents of polyol + Equivalents of water) × 100 Here, Equivalent weight of isocyanate = Number of polyisocyanates used × NCO content (%) × 100 / Molecular weight of NCO The equivalent weight of the polyol = OHV × the amount of polyol used ÷ the molecular weight of KOH, where OHV is the hydroxyl value of the polyol (mgKOH / g). Equivalent amount of water = Number of parts of water used × Number of OH groups in water / Molecular weight of water In the above formula, the unit of the number of parts used is weight (g), the molecular weight of the NCO group is 42, the NCO content is the proportion of NCO groups in the polyisocyanate compound expressed as mass%, and for the sake of unit conversion in the above formula, the molecular weight of KOH is assumed to be 56,100, the molecular weight of water is assumed to be 18, and the number of OH groups in water is assumed to be 2.

[0035] (Liquid flame retardant) The foamed urethane resin composition of the present invention contains a flame retardant that is liquid at room temperature. Here, room temperature means 23°C. By including a liquid flame retardant, the above-mentioned steel ball sinking distance and melting diameter distance can be easily adjusted to a desired range, and because it is liquid, wear of equipment used when using the foamed urethane resin composition can be suppressed. Examples of liquid flame retardants include phosphate ester-based flame retardants such as monophosphate esters and condensed phosphate esters. Examples of monophosphate esters, though not particularly limited, include trimethyl phosphate, triethyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, and tris(β-chloropropyl) phosphate. Examples of condensed phosphate esters are not particularly limited, but include resorcinol polyphenyl phosphate (trade name CR-733S), bisphenol A polycrezyl phosphate (trade name CR-741), and aromatic condensed phosphate esters (trade name CR747). The liquid flame retardant content is preferably 5 to 100 parts by mass, more preferably 10 to 80 parts by mass, and even more preferably 20 to 70 parts by mass, per 100 parts by mass of the polyol compound.

[0036] (Foam stabilizer) The foamable urethane resin composition of the present invention may optionally contain a foam stabilizer. Examples of foam stabilizers include polyoxyalkylene foam stabilizers such as polyoxyalkylene alkyl ethers, and surfactants such as silicone foam stabilizers such as organopolysiloxanes. However, any foam stabilizer with a structure having polar and nonpolar parts within its molecule can provide a surfactant effect, so the invention is not limited to the above types. Furthermore, the silicone foam stabilizer may include a graft copolymer of polydimethylsiloxane and polyethylene glycol. The foam stabilizer content is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 8 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the polyol compound. The foam stabilizer may be used alone or two or more types may be used.

[0037] (Foaming agent) The foamable urethane resin composition of the present invention contains a foaming agent. Specific examples of foaming agents include, for example, water, low-boiling hydrocarbons, chlorinated aliphatic hydrocarbon compounds, fluorine compounds, hydrochlorofluorocarbon compounds, hydrofluorocarbons, ether compounds, and hydrofluoroolefins. Furthermore, examples of foaming agents include organic physical foaming agents such as mixtures of these compounds, and inorganic physical foaming agents such as nitrogen gas, oxygen gas, argon gas, and carbon dioxide gas. Examples of the low-boiling hydrocarbons mentioned above include propane, butane, pentane, hexane, heptane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, and cycloheptane. Examples of the above-mentioned chlorinated aliphatic hydrocarbon compounds include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride. Examples of the fluorine compounds mentioned above include CHF3, CH2F2, and CH3F. Examples of the above-mentioned hydrochlorofluorocarbon compounds include trichloromonofluoromethane, trichlorotrifluoroethane, and dichloromonofluoroethane (e.g., HCFC141b (1,1-dichloro-1-fluoroethane), HCFC22 (chlorodifluoromethane), HCFC142b (1-chloro-1,1-difluoroethane)). Examples of the above-mentioned hydrofluorocarbons include HFC-245fa (1,1,1,3,3-pentafluoropropane) and HFC-365mfc (1,1,1,3,3-pentafluorobutane). Examples of the ether compounds mentioned above include diisopropyl ether. Examples of the above-mentioned hydrofluoroolefins include HFO-1233zd(E) (trans-1-chloro-3,3,3-trifluoropropene), HFO-1234yf (2,3,3,3-tetrafluoro-1-propene), and HFO-1336mzz(Z) (cis-1,1,1,4,4,4-hexafluorobuta-2-ene).

[0038] In the present invention, the foaming agent preferably contains water, and more specifically, a foaming agent comprising water in combination with at least one compound selected from the low-boiling hydrocarbons, chlorinated aliphatic hydrocarbon compounds, fluorine compounds, hydrochlorofluorocarbon compounds, hydrofluorocarbons, ether compounds, and hydrofluoroolefins mentioned above is preferred. As water, for example, ion-exchanged water, distilled water, etc., can be used as appropriate. The amount of water per 100 parts by mass of polyol compound is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and preferably 2.0 parts by mass or less, more preferably 1.5 parts by mass or less, and even more preferably 1.1 parts by mass or less. If the water content is above these lower limits, it becomes easier to foam the foamable urethane resin composition and to adjust the density to a desired range. Also, if the water content is below these upper limits, it becomes easier to adjust the sinking distance and melting diameter distance of the steel ball in the hot steel ball evaluation of the polyurethane foam to the desired range mentioned above.

[0039] In the present invention, the foaming agent preferably contains a hydrofluoroolefin, and more preferably contains both the hydrofluoroolefin and the water described above. The amount of hydrofluoroolefin per 100 parts by mass of the polyol compound is preferably 10 to 60 parts by mass, more preferably 15 to 50 parts by mass, and even more preferably 25 to 45 parts by mass.

[0040] (catalyst) The foamable urethane resin composition of the present invention contains a catalyst. The catalyst may contain, for example, one or both of a urethane catalyst and a trimerizing catalyst, and it is preferable that both be included. The catalyst contained in the foamable urethane resin composition shall not be considered an inorganic filler in the present invention.

[0041] Urethane catalysts are catalysts that promote the reaction between polyol components and polyisocyanates. Specifically, examples include amino compounds, tin compounds, bismuth compounds, and acetylacetone metal salts. Examples of the aforementioned amino compounds include pentamethyldiethylenetriamine, triethylamine, N-methylmorpholine bis(2-dimethylaminoethyl) ether, bis(2-dimethylaminoethyl) ether, N,N,N',N”,N”-pentamethyldiethylenetriamine, N,N,N'-trimethylaminoethyl-ethanolamine, bis(2-dimethylaminoethyl) ether, N-methyl-N',N'-dimethylaminoethylpiperazine, imidazole compounds in which the secondary amine functional group in the imidazole ring is substituted with a cyanoethyl group, N,N-dimethylcyclohexylamine, diazabicycloundecene, triethylenediamine, tetramethylethylenediamine, tetramethylhexamethylenediamine, 1-methylimidazole, trimethylaminoethylpiperazine, and tripropylamine. Examples of tin compounds include stannous octoate, dibutyltin diacetate, and dibutyltin dilaurate. Examples of bismuth compounds include bismuth neodecanoate and bismuth octoate. Examples of acetylacetone metal salts include aluminum acetylacetone, iron acetylacetone, copper acetylacetone, zinc acetylacetone, beryllium acetylacetone, chromium acetylacetone, indium acetylacetone, manganese acetylacetone, molybdenum acetylacetone, titanium acetylacetone, cobalt acetylacetone, vanadium acetylacetone, and zirconium acetylacetone. The urethane catalyst may be used alone or in combination of two or more types.

[0042] There are no particular limitations on the amount of urethane catalyst blended in the foamed urethane resin composition, but it is preferably in the range of 0.3 to 10 parts by mass, more preferably in the range of 0.5 to 8 parts by mass, and even more preferably in the range of 1 to 5 parts by mass per 100 parts by mass of urethane resin. By keeping it within the above range, the reaction between the polyol compound and the polyisocyanate compound can be promoted at an appropriate reaction rate. Note that 100 parts by mass of urethane resin means a total of 100 parts by mass of the polyol compound and the polyisocyanate compound.

[0043] Trimerization catalysts are catalysts that promote trimerization, which involves the formation of isocyanurate bonds. In polyurethane resins, the flame retardancy of polyurethane foam is improved by the promotion of trimerization. As trimerization catalysts, aromatic compounds such as tris(dimethylaminomethyl)phenol, 2,4-bis(dimethylaminomethyl)phenol, and 2,4,6-tris(dialkylaminoalkyl)hexahydro-S-triazine, alkali metal salts such as potassium acetate, sodium acetate, potassium 2-ethylhexanoate, sodium 2-ethylhexanoate, potassium octoate, and sodium octoate, aziridines such as 2-ethylaziridine, lead compounds such as lead naphthenate and lead octoate, alkoxide compounds such as sodium methoxide, phenolate compounds such as potassium phenoxide, tertiary ammonium salts such as trimethylammonium salt, triethylammonium salt, and triphenylammonium salt, and quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium, and tetraphenylammonium salt can be used. The trimerizing catalyst may be used alone or in combination of two or more types.

[0044] The amount of trimerizing catalyst is not particularly limited, but it is preferably in the range of 0.3 to 10 parts by mass, more preferably in the range of 0.5 to 8 parts by mass, and even more preferably in the range of 0.8 to 5 parts by mass, per 100 parts by mass of urethane resin. By setting the amount of trimerizing catalyst within the above range, isocyanurate bonds are appropriately formed, improving flame retardancy. Furthermore, from the viewpoint of improving the curing speed and flame retardancy of the urethane, the total amount of catalyst is preferably 0.5 to 20 parts by mass, more preferably 1 to 16 parts by mass, and even more preferably 2 to 10 parts by mass, per 100 parts by mass of urethane resin.

[0045] Furthermore, these trimerizing catalysts and urethane catalysts do not fall under the category of inorganic fillers described later in the present invention.

[0046] The foamed urethane resin composition may contain additives such as phenolic, amine, or sulfur-based antioxidants, heat and light stabilizers, metal damage inhibitors, antistatic agents, crosslinking agents, lubricants, softeners, pigments, and tackifying resins, to the extent that they do not impede the effects of the present invention.

[0047] (Inorganic filler) The foamed urethane resin composition of the present invention preferably contains substantially no inorganic fillers. By substantially omitting inorganic fillers, it is possible to provide a foamed urethane resin composition that is less prone to precipitation during storage, has excellent handling properties, and can suppress wear on equipment used during use. Here, "substantially free of inorganic fillers" means that, based on the total amount of the foamed urethane resin composition, the inorganic filler content is 5% by mass or less, preferably 1% by mass or less.

[0048] Inorganic fillers are inorganic compounds in particulate or fibrous form, such as metals, metal oxides, metal hydroxides, and ceramics. Examples include solid flame retardants and inorganic fillers other than solid flame retardants. The above-mentioned solid flame retardants are flame retardants that are solid at 23°C, and examples include antimony-containing flame retardants such as antimony oxide, antimonate salts, and pyroantimonate salts; metal hydroxide-based flame retardants such as magnesium hydroxide, calcium hydroxide, and aluminum hydroxide; boron-containing flame retardants such as lithium borate and sodium borate; phosphinic acid-based flame retardants; phosphate-containing flame retardants; bromine-containing flame retardants; and red phosphorus. In addition to solid flame retardants, other inorganic fillers include, for example, silica, diatomaceous earth, alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, ferrites, basic magnesium carbonate, calcium carbonate, magnesium carbonate, barium carbonate, dawsonite, hydrotalcite, calcium sulfate, barium sulfate, gypsum fiber, potassium salts such as calcium silicate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica pulp, aluminum nitride, boron nitride, silicon nitride, carbon black, graphite, carbon fiber, carbon pulp, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum porate, molybdenum sulfide, silicon carbide, stainless steel fiber, various magnetic powders, slag fiber, fly ash, silica alumina fiber, alumina fiber, silica fiber, zirconia fiber, etc.

[0049] The foamed urethane resin composition of the present invention hardens through a reaction between a polyol compound and a polyisocyanate compound, and therefore its viscosity changes over time. For this reason, before using the foamed urethane resin composition, it is preferable to divide it into two or more parts to prevent it from reacting and hardening. Then, when using the foamed urethane resin composition, it is preferable to combine the two or more parts into one.

[0050] When dividing a foamed urethane resin composition into two or more parts, the curing reaction should be initiated only after the components of the divided foamed urethane resin composition are mixed, rather than each component curing starting on its own. Typically, a foamed urethane resin composition is divided into a polyol composition containing a polyol compound and a polyisocyanate composition containing a polyisocyanate compound.

[0051] The above-mentioned liquid flame retardant, blowing agent, catalyst, and optionally added foam stabilizer, which are at room temperature, may be contained in the polyol composition, in the polyisocyanate composition, or provided separately from the polyol composition and the polyisocyanate composition, but it is preferable that they be contained in the polyol composition.

[0052] The method for producing a foamed urethane resin composition is not particularly limited, but examples include preparing a polyol composition and a polyisocyanate composition by kneading them in advance and then mixing the two, or kneading each component that makes up the foamed urethane resin composition. However, it is usually produced by mixing a polyol composition and a polyisocyanate composition. The mixing of each component can be carried out by known methods, for example, by using known equipment such as a high-pressure foamer, a low-pressure foamer, a spray foamer, and a hand mixer.

[0053] (Viscosity of polyol compositions) The viscosity of the polyol composition at 20°C is not particularly limited, but is preferably 2,000 mPa·s or less, and more preferably 1,000 mPa·s or less. By keeping the viscosity of the polyol liquid below the above upper limit, the fluidity of the foaming urethane resin composition is improved, and mixing defects can be suppressed. The viscosity of the polyol composition can be appropriately adjusted, for example, by the molecular weight of the polyol compound used. The viscosity of the polyol composition was measured using a B-type viscometer at a temperature of 20°C.

[0054] (Application) The uses of the foamed urethane resin composition of the present invention are not particularly limited, but it can be used to fill cavities in structures such as buildings, furniture, automobiles, trains, and ships, or to spray onto such structures. In particular, it is preferable to use it for spraying onto structures, that is, as a foamed urethane resin composition for spraying. Spraying can be carried out using a spraying device (e.g., GRACO A-25) and a spray gun (e.g., Gasmar D-gun). Typical spraying devices and spray guns react the isocyanate and polyol in the foaming concentrate in an equal volume ratio before spraying. Therefore, the foaming concentrate can be reacted with a volume ratio of 1.0 isocyanate to 0.8-1.2 polyol. Spraying can be carried out by temperature-controlled polyol composition and polyisocyanate composition in separate containers within the spraying device, causing them to collide and mix at the tip of the spray gun, and then atomizing the mixture using air pressure. Spraying devices and spray guns are well-known and commercially available.

[0055] [Polyurethane foam] The polyurethane foam of the present invention is formed from the above-described foamable urethane resin composition, and more specifically, is obtained by foaming and curing the foamable urethane resin composition. Polyurethane foam exhibits a steel ball sinking distance of 10 mm or less in the hot steel ball evaluation. If the steel ball sinking distance exceeds 10 mm, the polyurethane foam is more likely to spread fire when exposed to a fire, making it difficult to effectively prevent the spread of fire. From the viewpoint of effectively preventing the spread of fire, the steel ball sinking distance is preferably 5 mm or less, more preferably 3 mm or less, even more preferably 2 mm or less, and even more preferably 0 mm. The steel ball sinking distance is 0 mm or more. The evaluation method for the steel ball sinking distance is as described above.

[0056] The polyurethane foam preferably has a melting diameter distance of 15 mm or less in the hot steel ball evaluation. If the melting diameter distance exceeds 15 mm, the polyurethane foam is more likely to burn and spread when exposed to fire, making it difficult to effectively prevent the spread of fire. From the viewpoint of effectively preventing the spread of fire, the melting diameter distance is preferably 14 mm or less, more preferably 13 mm or less, and even more preferably 12 mm or less. The melting diameter distance is 0 mm or more.

[0057] Incidentally, fires caused by polyurethane foam are largely due to sparks and fireballs (high-temperature heated iron masses) during welding and cutting. According to the inventors' findings, it has been found that when a fireball comes into contact with polyurethane foam, it penetrates the interior while melting the resin, resulting in a risk of ignition and fire spreading from within the polyurethane foam. The above hot steel ball evaluation reproduces and evaluates fires caused by polyurethane foam during welding and cutting, and can evaluate whether polyurethane foam is resistant to fire spreading.

[0058] The density of polyurethane foam is not particularly limited, but is typically between 20 and 200 kg / m³. 3 It is preferable that the density be within this range. 3 By doing the following, the polyurethane foam becomes lighter, improving its ease of application to structures. Also, 20 kg / m 3 By doing so, the desired flame retardancy is more easily achieved. From these perspectives, the density of the polyurethane foam should be 25-100 kg / m³. 3 It is more preferable that the range be 25-80 kg / m 3 It is even more preferable that the density be within this range. The density of the polyurethane foam can be measured in accordance with JIS K7222. [Examples]

[0059] The present invention will be described in more detail by reference to examples, but the present invention is not limited in any way by these examples.

[0060] The details of each component used in each example and comparative example are as follows. (1) Polyol compounds (i) Polyether polyol containing resin microparticles • Resin microparticles containing PPG1 (hydroxyl value = 315 mg KOH / g). The resin microparticles are a polymer of acrylonitrile, the type of polyether polyol is Mannich-type polyether polyol, and the microparticle content is 0.5-1.2 wt%. • Resin microparticles containing PPG2 (hydroxyl value = 385 mg KOH / g). The resin microparticles are a polymer of acrylonitrile, the type of polyether polyol is TDA-based polyether polyol, and the microparticle content is 0.5-1.2 wt%. The resin microparticle content in PPG1 and PPG2, which contain resin microparticles, was 0.5 to 1.2 wt%, as described above, but it is shown as 1.0 wt% in Table 1. (ii) Polyether polyols that do not contain resin fine particles • Sucrose-based polyether polyol (manufactured by Mitsui Chemicals, product name: GR84, hydroxyl value = 450 mg KOH / g) • Sorbitol-based polyether polyol (manufactured by Mitsui Chemicals, product name: Actcol SOR400, hydroxyl value = 400 mg KOH / g) • Ethylenediamine-based polyether polyol (manufactured by AGC Inc., product name: Exenol 750ED, hydroxyl value = 760 mg KOH / g) (iii) Polyester polyol • p-phthalate-based polyester polyol (manufactured by Kawasaki Chemical Co., Ltd., product name: RFK-505, hydroxyl value = 250 mg KOH / g) (2) Liquid flame retardant • Phosphate ester-based flame retardant <Tris(β-chloropropyl) phosphate> (manufactured by Daihachi Chemical Co., Ltd., product name: TMCPP) (3) Foam stabilizer • Silicone-based foam stabilizer (manufactured by Toray Dow Corning, product name: SH-193) (4) Catalyst (i) Trimerization catalyst • Quaternary ammonium salt (manufactured by Evonik Japan, product name: TMR-7) (ii) Urethane catalyst • Imidazole compound (manufactured by Kao Corporation, product name: KL No. 390) • Bismuth compound (manufactured by Nitto Chemical Co., Ltd., product name: Neostan U-600) (5) Foaming agent ·water • HFO-1233zd <Hydrofluoroolefin> (Honeywell, product name: Solstice LBA) (6) Polyisocyanate compounds • MDI (manufactured by Sumika Covestro Urethane Co., Ltd., product name: 44V-20)

[0061] The measurement methods for each physical property and characteristic are as follows.

[0062] [Evaluation of hot steel balls] For the polyurethane foams prepared in each example and comparative example, the sinking distance and melting diameter distance of the steel ball were measured according to the following procedures (1) to (3). (1) Polyurethane foam was cut into cubes with sides of 50 mm to serve as test specimens. (2) A wire mesh was placed 30 mm from the burner opening of a Bunsen burner (outer flame length 70 mm), and a steel ball (SUS304) with a diameter of 10.0 mm and a weight of 4.15 g was placed on the wire mesh. The steel ball was heated for 7 minutes until the entire steel ball turned red, and the steel ball temperature was set to 630°C. The steel ball temperature was measured by moving the steel ball, heated as described above, from the wire mesh to another stand that would not affect the radiation temperature measurement. The steel ball temperature was measured using a radiation thermometer (Keyence FT-H40K), with the radiation coefficient of the steel ball used set to 0.45, and the value displayed by the radiation thermometer was divided by 0.45 to obtain the evaluation temperature (630°C). A new steel ball was used. (3) Under a 23°C atmosphere, the steel ball heated in (2) above was immediately placed on the center of the upper part of the test specimen in (1) above, and left until the steel ball had fully sunk in. Then, the cross section of the test specimen, which had been sufficiently cooled by leaving it at 23°C for 30 minutes, was cut, and the sinking distance and melting diameter distance of the steel ball were measured. Based on the sinking distance and melting diameter distance of the obtained steel balls, the degree of their flame-spreading properties was determined as follows.

[0063] ≪Evaluation Criteria for Hot Steel Balls≫ ○ The sinking distance of the steel ball is 5 mm or less, and the melting diameter distance is 15 mm or less. △··The sinking distance of the steel ball is 5 mm or less, and the melting diameter distance is greater than 15 mm. ×...In cases other than the above "〇" and "△"

[0064] [Maximum heating rate, total heat output] The maximum heat generation rate and total heat generation of the polyurethane foams prepared in each example and comparative example were evaluated by the following method. A mixture of polyol compound, liquid flame retardant, foam stabilizer, catalyst, and blowing agent, obtained by mixing according to the formulations shown in Table 1, and a polyisocyanate compound (total amount 200 g, liquid temperature 10°C) were added to a polypropylene beaker and stirred with a laboside spar for 3 seconds. Immediately thereafter, the mixture was spread onto a 12.5 mm thick gypsum board to obtain polyurethane foam. The polyurethane foam, bonded to the gypsum board as a base, was cut into pieces 10 cm long, 10 cm wide, and 3.25 cm thick (with 12.5 mm of gypsum board inside) to prepare samples for cone calorimeter testing, and the cone calorimeter test was performed as follows. The test samples were subjected to a radiant heat intensity of 50 kW / m² in accordance with the ISO-5660 test method. 2 The maximum heat generation rate and total heat generation were measured when heated for 5 minutes. Similar values ​​were obtained when the polyurethane foam was produced by spraying the foamed urethane resin composition onto the structure using a spraying device and spray gun, in addition to the method described above.

[0065] [Evaluation of contraction] The polyurethane foam obtained in each example and comparative example was processed into a shape measuring 10 cm in length, 10 cm in width, and 7 cm in thickness, and stored for 3 days at 40°C and 95% RH. The shape retention rate was calculated using the following formula, determining the retention rate for each length (length and width) and averaging these rates to obtain the overall shape retention rate. A shape retention rate of 100% means that there was no shrinkage at all. Retention rate = 100 × (length of one side after 3 days of storage) / (length of one side before storage). ○··Shape retention rate is between 95% and 100% × Less than 95%

[0066] [Example 1] According to the formulations in Table 1, a polyol compound, liquid flame retardant, foam stabilizer, catalyst, and blowing agent were measured into a 1000 mL polypropylene beaker and stirred with a hand mixer at 20°C for 10 seconds to prepare a polyol composition. Then, to the polyol composition cooled to 10°C, a polyisocyanate composition (polyisocyanate compound), also heated to 10°C, was added to prepare a foamable urethane resin composition. This composition was stirred with a labodies spar for 3 seconds to prepare a polyurethane foam. The above-described hot steel ball evaluation was performed using this polyurethane foam. The maximum heat generation rate, total heat generation, and shape retention rate were also evaluated using the above-described procedure. The results of each evaluation are shown in Table 1.

[0067] [Examples 2-5, Comparative Examples 1-5] A polyurethane foam was obtained in the same manner as in Example 1, except that the composition was changed as shown in Table 1. The above-described thermal steel ball evaluation was performed using this polyurethane foam. The maximum heat generation rate, total heat generation amount, and shape retention rate were also evaluated using the procedure described above. The results of each evaluation are shown in Table 1.

[0068] [Table 1]

[0069] As shown in each example, the polyurethane foam formed from the foamable urethane resin composition of the present invention was found to have a property of being difficult to spread flames, due to the short steel ball sinking distance and melting diameter distance. Furthermore, the polyurethane foam formed from the foamable urethane resin composition of the present invention was found to be difficult to shrink. In other words, a polyurethane foam was obtained that possesses both the property of being difficult to spread flames and the property of being difficult to shrink. In contrast, the polyurethane foam formed from the comparative example's foamable urethane resin composition was found to be prone to shrinkage because it did not contain resin fine particle-containing polyether polyol.

Claims

1. A foamed urethane resin composition comprising a polyol compound, a polyisocyanate compound, a flame retardant that is liquid at room temperature, a blowing agent, and a catalyst, The polyol compound comprises a polyol containing resin microparticles, wherein the content of the polyol containing resin microparticles is 5 to 20% by mass based on the total amount of polyol components. The polyol compound is a condensate of an aromatic dicarboxylic acid and a glycol, and contains a phthalic acid-based polyester polyol in which the aromatic dicarboxylic acid consists solely of phthalic acid, and the content of the phthalic acid-based polyester polyol is 80 to 95% by mass based on the total amount of the polyol component. The catalyst comprises a urethane catalyst and a trimerizing catalyst, the urethane catalyst comprises an imidazole compound and a bismuth compound, and the trimerizing catalyst comprises a quaternary ammonium salt. The blowing agent comprises a hydrofluoroolefin, The isocyanate index is between 200 and 700. The amount of the liquid flame retardant at room temperature is 20 to 100 parts by mass per 100 parts by mass of the polyol compound. A foamed urethane resin composition comprising the aforementioned foamed urethane resin composition, wherein the sinking distance of the steel ball in the following hot steel ball evaluation of the polyurethane foam is 10 mm or less. (Evaluation of heated steel balls) (1) Cut the polyurethane foam into cubes with sides of 50 mm to make test specimens. (2) Place a wire mesh 30 mm from the burner opening of a Bunsen burner (outer flame length 70 mm), place a steel ball with a diameter of 10.0 mm and a weight of 4.15 g on the wire mesh, and heat for at least 5 minutes until the entire steel ball turns red, bringing the steel ball temperature to 630°C. (3) In a 23°C atmosphere, immediately place the steel ball heated in (2) above on the center of the upper part of the test specimen in (1) above and leave it until the steel ball has fully sunk in. Then, cut the cross section of the sufficiently cooled test specimen and measure the sinking distance and melting diameter distance of the steel ball.

2. The foamed urethane resin composition according to claim 1, wherein the sinking distance of the steel ball in the hot steel ball evaluation is 5 mm or less and the melting diameter distance is 15 mm or less.

3. The polyurethane foam comprising the aforementioned foamable urethane resin composition was subjected to a test according to ISO 5660, with a radiant thermal intensity of 50 kW / m². ２ The total heat output when heated for 5 minutes was 8 MJ / m². ２ The foamed urethane resin composition according to claim 1 or 2, which is as follows:

4. The polyurethane foam comprising the aforementioned foamable urethane resin composition was subjected to a test according to ISO 5660, with a radiant thermal intensity of 50 kW / m². ２ The maximum heating rate after 5 minutes of heating was 200 kW / m². ２ The foamed urethane resin composition according to any one of claims 1 to 3, which is as follows:

5. The foaming urethane resin composition according to any one of claims 1 to 4, wherein the resin fine particle-containing polyol is an amine-based polyether polyol containing resin fine particles.

6. The foaming urethane resin composition according to any one of claims 1 to 5, wherein the resin fine particles are a polymer of at least one monomer selected from the group consisting of acrylonitrile, methacrylonitrile, fluorine-containing acrylonitrile, α-ethylacrylonitrile, styrene, vinyl acetate, and acrylic monomers.

7. The foamed urethane resin composition comprises a polyol composition containing a polyol compound, a flame retardant that is liquid at room temperature, a blowing agent, and a catalyst, and a polyisocyanate compound. The foamable urethane resin composition according to any one of claims 1 to 6, wherein the content of the resin fine particles on a basis of the total amount of the polyol composition is 0.01% by mass or more.

8. The foaming urethane resin composition according to any one of claims 1 to 7, wherein the weight ratio of the phthalate-based polyester polyol to the resin fine particle-containing polyol (phthalate-based polyester polyol / resin fine particle-containing polyol) is 95 / 5 to 55 / 45.

9. The foaming urethane resin composition according to any one of claims 1 to 8, wherein the foaming agent contains water, and the water content is 1.5 parts by mass or less per 100 parts by mass of the polyol compound.

10. A foaming urethane resin composition according to any one of claims 1 to 9, wherein the inorganic filler content is 5% by mass or less.

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