Polyurethane foam

Abstract

To provide a technique capable of securing flame retardancy by reducing the use amount of a halogen-based flame retardant and an antimony-based flame retardant, or without using the halogen-based flame retardant and the antimony-based flame retardant.SOLUTION: A polyurethane foam obtained from a composition comprising a polyol, a polyisocyanate, and a flame retardant, wherein the flame retardant comprises a phosphinate ester and a phosphate ester.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to polyurethane foams. [Background technology]

[0002] Patent Document 1 discloses a flame-retardant polyurethane composition containing chlorinated polyvinyl chloride and antimony oxide. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 03-007716 Summary of the Invention [Problem to be solved by the invention]

[0004] The use of halogenated and antimony-based flame retardants places a heavy burden on the environment and human health. Therefore, as halogenated and antimony-based flame retardants are either restricted substances or are likely to be restricted in the future, alternative substances are being sought.

[0005] The present disclosure aims to provide a technology that can ensure the flame retardancy of polyurethane foam by reducing the amount of halogen-based flame retardants and antimony-based flame retardants used, or by eliminating the use of halogen-based flame retardants and antimony-based flame retardants. [Means for solving the problem]

[0006] A polyurethane foam obtained from a composition comprising a polyol, a polyisocyanate, and a flame retardant, The flame retardant comprises a phosphinate ester and a phosphate ester. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a technology that can reduce the amount of halogen-based flame retardants and antimony-based flame retardants used, or ensure flame retardancy without using halogen-based flame retardants and antimony-based flame retardants. DETAILED DESCRIPTION OF THE INVENTION

[0008] Here, a preferred example of the present disclosure will be described. [1] A polyurethane foam obtained from a composition containing a polyol, a polyisocyanate, and a flame retardant, The flame retardant comprises a phosphinate ester and a phosphate ester. [2] The polyurethane foam according to [1], wherein the phosphinic acid ester comprises a compound represented by the following chemical formula (1): [ka] (In the formula, R 1 and R 2 are each independently a hydrocarbon group which may have a substituent other than halogen, and each n is independently an integer of 0 to 4, R 3 is a hydrocarbon group which may have a substituent other than a halogen and does not have a hydroxyl group. [3] The polyurethane foam according to [1] or [2], wherein the phosphate ester is an aromatic phosphate ester.

[0009] The present disclosure will be described in detail below. In this specification, when a numerical range is indicated using "-", it is intended to include both the lower limit and the upper limit unless otherwise specified. For example, the expression "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less". In addition, in this specification, the upper limit and lower limit of each numerical range can be combined in any way.

[0010] 1. Polyurethane foam The polyurethane foam is obtained from a composition containing a polyol, a polyisocyanate, and a flame retardant, and the flame retardant includes a phosphinate ester and a phosphate ester.

[0011] (1) Polyol The polyol is not particularly limited, and various polyols may be used alone or in combination of two or more kinds. Examples of polyols include polyether polyols, polyester polyols, polyether ester polyols, polycarbonate diols, and polyols having a carbon-carbon bond main chain. Examples of polyether polyols include polyoxypropylene-polyoxyethylene polyols, polymer polyols, and polyoxytetramethylene glycols. Examples of polyester polyols include aliphatic or aromatic polycondensation polyester polyols and polycaprolactone polyols. Examples of polyols having a carbon-carbon bond-based main chain include polyolefin polyols such as polybutadiene polyol and isoprene polyol, and acrylic polyols.

[0012] (1.1) Polyether polyol Examples of polyether polyols include polyether polyols obtained by adding one or more of ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, epichlorohydrin, styrene oxide, etc. to one or more of the following initiators (compounds), or polytetramethylene ether glycol.

[0013] (1.1.1) Initiator (1.1.1.1) Polyhydric alcohols and alkylene oxide adducts of polyhydric alcohols Examples of polyhydric alcohols: [Difunctional alcohols] Ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, trimethylene glycol [Trifunctional alcohol] Glycerin, trimethylolpropane [Tetrafunctional alcohol] Pentaerythritol [Hexafunctional alcohol] Sorbitol [Octafunctional alcohol] Sucrose (1.1.1.2) Alkylene oxide adducts of polyhydric phenols Examples of alkylene oxide adducts of polyhydric phenols: alkylene oxide adducts of bisphenol A (1.1.1.3) Polyhydroxy compounds Examples of polyhydroxy compounds: phosphoric acid, benzene phosphoric acid, polyphosphoric acid (e.g., tripolyphosphoric acid and tetrapolyphosphoric acid), etc. (1.1.1.4) Phenol-aniline-formaldehyde ternary condensation products (1.1.1.5) Aniline-formaldehyde condensation products (1.1.1.6) Polyamines Examples of polyamines: ethylenediamine, diethylenetriamine, triethylenetetramine, methylenebisorthochloroaniline, 4,4- and 2,4'-diphenylmethanediamine, 2,4-tolylenediamine, 2,6-tolylenediamine, etc. (1.1.1.7) Alkanolamines Examples of alkanolamines: triethanolamine, diethanolamine, etc.

[0014] (1.1.2) Polymer polyol The polymer polyol is a polyol obtained by graft polymerizing the above-mentioned polyether polyol with an ethylenically unsaturated compound such as acrylonitrile, styrene, or alkyl methacrylate.

[0015] (1.1.3) Ethylene oxide unit content The content of ethylene oxide units in the polyether polyol is not particularly limited, and is preferably more than 0 mol% and not more than 50 mol%, more preferably more than 3 mol% and not more than 20 mol%, and even more preferably more than 5 mol% and not more than 10 mol%, when the total amount of alkylene oxide units is taken as 100 mass%.

[0016] (1.2) Polyester polyol The polyester polyol is a polyester polyol obtained by condensation of one or more compounds having at least two hydroxyl groups with one or more compounds having at least two carboxyl groups, or a ring-opening polymer of a cyclic ester such as caprolactone or methylvalerolactone.

[0017] (1.2.1) Examples of compounds having at least two hydroxy groups Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, tetramethylene glycol, neopentyl glycol, methylpentanediol, butylethylpropanediol, hexamethylene glycol, decamethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol

[0018] (1.2.2) Examples of compounds with at least two carboxyl groups Oxalic acid, malonic acid, maleic acid, succinic acid, tartaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, hemimellitic acid

[0019] (1.3) Polycarbonate polyol Examples of polycarbonate polyols include those obtained by transesterification of a low molecular weight polyol such as butanediol or hexanediol with a low molecular weight carbonate such as propylene carbonate or diethyl carbonate.

[0020] (1.4) Polyolefin polyol Examples of polyolefin polyols include polybutadiene polyols, polyisoprene polyols, hydrogenated polybutadiene polyols, and hydrogenated polyisoprene polyols.

[0021] (1.5) Plant-derived polyols In addition to the above polyols, the polyol may also contain a plant-derived polyol. Examples of plant-derived polyols include castor oil-based polyols, soybean oil-based polyols, palm oil-based polyols, palm kernel oil-based polyols, coconut oil-based polyols, cashew oil-based polyols, olive oil-based polyols, cottonseed oil-based polyols, safflower oil-based polyols, sesame oil-based polyols, sunflower oil-based polyols, and linseed oil-based polyols. Plant-derived polyols usually have 2-3 functional hydroxyl groups per molecule. Examples of castor oil-based polyols include castor oil, reaction products of castor oil with polyols, esterification reaction products of castor oil fatty acids with polyols, etc. Examples of polyols to be reacted with castor oil or castor oil fatty acids include dihydric polyols such as ethylene glycol, diethylene glycol, and propylene glycol, and trihydric or higher polyols such as glycerin, trimethylolpropane, hexanetriol, and sorbitol. Examples of soybean oil-based polyols include polyols derived from soybean oil, such as a reaction product of soybean oil with a polyol and an esterification reaction product of soybean oil fatty acid with a polyol. The polyols to be reacted with soybean oil or soybean oil fatty acid can be the same as those used for castor oil. The same applies to palm oil-based polyols, cashew oil-based polyols, and the like. The various polyols exemplified as plant-derived polyols may be used alone or in combination of two or more.

[0022] (1.6) Weight average molecular weight, hydroxyl value, number of functional groups The weight average molecular weight, hydroxyl value, and number of functional groups of the polyol are not particularly limited. The weight average molecular weight of the polyol is preferably from 500 to 10,000, more preferably from 1,000 to 6,000, and even more preferably from 1,500 to 4,000. The weight average molecular weight of the polyol can be measured by gel permeation chromatography (GPC). The hydroxyl value of the polyol is preferably 40 mgKOH / g or more and 300 mgKOH / g or less, more preferably 45 mgKOH / g or more and 150 mgKOH / g or less, and even more preferably 50 mgKOH / g or more and 80 mgKOH / g or less. The functionality of the polyol is preferably 2.0 or more, more preferably 2.1 or more, and even more preferably 2.2 or more. The functionality of the polyol is, for example, 4.0 or less.

[0023] (2) Flame retardants The flame retardant includes a phosphinic acid ester and a phosphate ester. The flame retardant may include only a phosphinic acid ester and a phosphate ester, or may further include other compounds in addition to the phosphinic acid ester and the phosphate ester. However, from the viewpoint of reducing the burden on the environment and the human body, the flame retardant preferably does not include a halogen-based flame retardant, preferably does not include an antimony-based flame retardant, and more preferably does not include a halogen-based flame retardant or an antimony-based flame retardant.

[0024] The total amount of the flame retardants is not particularly limited. From the viewpoint of ensuring sufficient flame retardancy, the total amount of the flame retardants is preferably 2 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 8 parts by mass or more, and particularly preferably 10 parts by mass or more, per 100 parts by mass of polyol. On the other hand, from the viewpoint of maintaining the various physical properties of the polyurethane foam and from the viewpoint of production costs, the total amount of the flame retardants is preferably 35 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 26 parts by mass or less, and particularly preferably 23 parts by mass or less. From these viewpoints, the total amount of the flame retardants is preferably 2 parts by mass or more and 35 parts by mass or less, more preferably 5 parts by mass or more and 30 parts by mass or less, even more preferably 8 parts by mass or more and 26 parts by mass or less, and particularly preferably 10 parts by mass or more and 23 parts by mass or less.

[0025] (2.1) Phosphinic acid esters The phosphinate ester is preferably a cyclic phosphinate ester, and more preferably a compound of the following chemical formula (1). [ka] In the formula, R 1 and R 2 R is a hydrocarbon group which may have a substituent other than a halogen. 1 The number of carbon atoms in R is, for example, 1 to 3. 2 The number of carbon atoms is, for example, 1 to 3. Each n is independently an integer of 0 to 4, preferably 0 to 2, more preferably 0 to 1, and even more preferably 0. R 3 R is a hydrocarbon group which may have a substituent other than a halogen and does not have a hydroxyl group. 3 The number of carbon atoms in R is, for example, 1 to 8. 3 is preferably a phenyl group, a tolyl group, or a xylyl group, and more preferably a phenyl group.

[0026] The phosphinic acid ester is, for example, a compound represented by the following chemical formula (2): The compound represented by the following chemical formula (2) is also called 9,10-dihydro-10-benzyl-9-oxa-10-phosphaphenanthrene-10-oxide (CAS No. 113504-81-7). An example of a commercially available product is BCA manufactured by Sanko Co., Ltd. [ka]

[0027] The properties of the phosphinic acid ester are not particularly limited. The phosphinic acid ester is preferably in the form of a powder. The melting point of the phosphinic acid ester is preferably higher than 100°C. The decomposition temperature of the phosphinic acid ester is preferably 250°C or higher, more preferably 300°C or higher. The decomposition temperature of the phosphinic acid ester is, for example, 500°C or lower. From the viewpoint of improving flame retardancy, the phosphorus content of the phosphinic acid ester may be, for example, 9% by mass or more and 11% by mass. The phosphorus content (mass%) can be calculated as (mass of phosphorus atoms / mass of one molecule of the phosphinic acid ester) × 100, where (mass of phosphorus atoms / mass of one molecule of the phosphinic acid ester) × 100.

[0028] The amount of the phosphinic acid ester is not particularly limited. From the viewpoint of ensuring sufficient flame retardancy, the amount of the phosphinic acid ester is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and particularly preferably 8 parts by mass or more, per 100 parts by mass of polyol. On the other hand, from the viewpoint of maintaining the various physical properties of the polyurethane foam and from the viewpoint of production costs, the amount of the phosphinic acid ester is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and particularly preferably 15 parts by mass or less. From these viewpoints, the amount of the phosphinic acid ester is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 25 parts by mass or less, even more preferably 5 parts by mass or more and 20 parts by mass or less, and particularly preferably 8 parts by mass or more and 15 parts by mass or less.

[0029] (2.2) Phosphate esters The phosphate ester is preferably an aromatic phosphate ester, and more preferably a compound represented by the following chemical formula (3). [ka] where k is an integer from 0 to 5, and X 1 represents a divalent arylene group, p, q, r, and s each represent 0 or 1, and R 1 , R 2 , R 3 and R 4 represents an aryl group having 6 to 20 carbon atoms which may be substituted with an alkyl group.

[0030] The compound may be a mixture of compounds having different k values, in which case k is the average value of the mixture. k is usually an integer of 0 to 5, and in the case of a mixture, k is preferably 0.5 to 2, more preferably 0.6 to 1.5, and even more preferably 0.8 to 1.2.

[0031] R 1 , R 2 , R 3 and R 4 is an aryl group having 6 to 20 carbon atoms which may be substituted with an alkyl group. Examples of such an aryl group include a phenyl group, a cresyl group, a xylyl group, an isopropylphenyl group, a butylphenyl group, a tert-butylphenyl group, a di-tert-butylphenyl group, and a p-cumylphenyl group. Of these, a phenyl group, a cresyl group, and a xylyl group are more preferred.

[0032] X 1is a divalent arylene group, for example, a divalent group derived from a dihydroxy compound such as resorcinol, hydroquinone, bisphenol A, 2,2'-dihydroxybiphenyl, 2,3'-dihydroxybiphenyl, 2,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, or 2,7-dihydroxynaphthalene. Among these, divalent groups derived from resorcinol, bisphenol A, or 3,3'-dihydroxybiphenyl are preferred.

[0033] The phosphate ester may be a condensed phosphate ester or a non-condensed phosphate ester. The condensed phosphate ester is preferably at least one selected from the group consisting of resorcinol bis-diphenyl phosphate (RDP), resorcinol bis-dixylenyl phosphate (RDX), bisphenol A bis-diphenyl phosphate (BDP), and biphenyl bis-diphenyl phosphate. Among these, resorcinol bis-diphenyl phosphate (RDP) and / or resorcinol bis-dixylenyl phosphate (RDX) are more preferred. The non-condensed phosphate ester is preferably at least one selected from the group consisting of cresyl diphenyl phosphate (CDP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), tert-butylphenyl diphenyl phosphate, bis-(tert-butylphenyl)phenyl phosphate, tris-(tert-butylphenyl)phosphate, isopropylphenyl diphenyl phosphate, bis-(isopropylphenyl)diphenyl phosphate, and tris-(isopropylphenyl)phosphate. Among these, cresyl diphenyl phosphate (CDP) is more preferred.

[0034] The properties of the phosphate ester are not particularly limited. The phosphate ester is preferably liquid. The decomposition temperature of the phosphate ester is preferably 420°C or lower, more preferably 410°C or lower. The decomposition temperature of the phosphate ester is, for example, 250°C or higher. From the viewpoint of improving flame retardancy, the phosphorus content of the phosphate ester is preferably 9% by mass or higher. The phosphorus content of the phosphate ester is usually 12% by mass or lower. The phosphorus content (mass%) can be calculated as (mass of phosphorus atoms / mass of one molecule of the phosphate ester) × 100, where (mass of phosphorus atoms / mass of one molecule of the phosphate ester) is the mass of phosphorus atoms contained in the phosphate ester.

[0035] The amount of the phosphate ester is not particularly limited. From the viewpoint of ensuring sufficient flame retardancy, the amount of the phosphate ester is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 3 parts by mass or more, and particularly preferably 4 parts by mass or more, per 100 parts by mass of polyol. On the other hand, from the viewpoint of maintaining the various physical properties of the polyurethane foam and from the viewpoint of production costs, the amount of the phosphate ester is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and particularly preferably 15 parts by mass or less. From these viewpoints, the amount of the phosphate ester is preferably 0.5 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 25 parts by mass or less, even more preferably 3 parts by mass or more and 20 parts by mass or less, and particularly preferably 4 parts by mass or more and 15 parts by mass or less.

[0036] (4) Catalyst The polyurethane foam composition may contain a catalyst. The catalyst is not particularly limited. Various catalysts may be used alone or in combination of two or more. As the catalyst, an amine catalyst or a quaternary ammonium salt catalyst can be used. Specific examples of these catalysts are shown below. Tertiary amine catalysts such as N,N-dimethylaminohexanol, N,N,N'-trimethyl-N'-aminopropyl-bis(aminoethyl)ether, triethylenediamine, triethylamine, tripropylamine, triisopropanolamine, tributylamine, trioctylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N,N-dimethylethanolamine, N,N-dimethylaminoethoxyethoxyethanol, and N,N-dimethylaminoethoxyethanol; formate and other salts of triethylenediamine; oxyalkylene adducts of amino groups of primary and secondary amines; azacyclic compounds such as N,N'-dialkylpiperazines; and amine catalysts having an amino group as a functional group such as N,N,N",N"-tetramethyldiethylenetriamine. Further, quaternary ammonium salt catalysts such as tetraalkylammonium halides such as tetramethylammonium chloride, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide salts, and tetraalkylammonium organic acid salts such as tetramethylammonium 2-ethylhexanoate, 2-hydroxypropyltrimethylammonium formate, and 2-hydroxypropyltrimethylammonium 2-ethylhexanoate can also be used. The amount of one or more catalysts selected from the group consisting of amine catalysts and quaternary ammonium salt catalysts in the polyurethane foam composition is not particularly limited. From the viewpoint of sufficiently promoting the polyurethane-forming reaction, the amount of these catalysts is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.07 parts by mass or more, per 100 parts by mass of polyol. On the other hand, from the viewpoint of maintaining the physical properties of the polyurethane foam and from the viewpoint of production costs, the amount is preferably 1 part by mass or less, more preferably 0.8 parts by mass or less, and even more preferably 0.5 parts by mass or less. From these viewpoints, the amount of one or more catalysts selected from the group consisting of amine catalysts and quaternary ammonium salt catalysts is preferably 0.01 parts by mass or more and 1 part by mass or less, more preferably 0.05 parts by mass or more and 0.8 parts by mass or less, and even more preferably 0.07 parts by mass or more and 0.5 parts by mass or less, per 100 parts by mass of polyol.

[0037] As the catalyst, a metal catalyst (organometallic catalyst) can be used. As the metal catalyst, any conventionally known metal catalyst can be used without any particular limitation. Examples of usable metal catalysts include metal salts of Sn (tin), Pb (lead), Bi (bismuth), Ni (nickel), Co (cobalt), Fe (iron), Zr (zirconium), Cu (copper), Zn (zinc), etc., and organic acid metal salts. More specifically, the following metal catalysts can be used: Sn catalysts: tin(II) octoate (tin 2-ethylhexanoate, stannous dioctoate), tin(II) acetate, tin(II) octanoate, stannous dioleate, tin(II) neodecanoate, stannous dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dioctyltin dilaurate, dibutyltin dimaleate, dioctyltin diacetate, etc. Pb catalyst: lead octoate, lead naphthenate, etc. Bi catalyst: bismuth octoate, bismuth naphthenate, bismuth neodecanoate, bismuth rosinate, etc. Fe catalyst: iron acetylacetonate, etc. Zr catalyst: zirconium acetylacetonate, etc. Ni catalyst: nickel acetylacetonate, nickel octylate, nickel naphthenate, etc. Co catalyst: cobalt acetylacetonate, cobalt octylate, cobalt naphthenate, etc.

[0038] The amount of metal catalyst in the polyurethane foam composition is not particularly limited. From the viewpoint of sufficiently promoting the polyurethane-forming reaction, the amount of metal catalyst is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of polyol. On the other hand, from the viewpoint of suppressing volatile organic compounds (e.g., 2-ethylhexanoic acid) derived from the metal catalyst, the amount is preferably 1.0 part by mass or less, more preferably 0.6 parts by mass or less, and even more preferably 0.4 parts by mass or less. From these viewpoints, the amount of metal catalyst is preferably 0.01 parts by mass or more and 1.0 parts by mass or less, more preferably 0.05 parts by mass or more and 0.6 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.4 parts by mass or less, per 100 parts by mass of polyol.

[0039] (5) Foam stabilizer The polyurethane foam composition may contain a foam stabilizer. The foam stabilizer is not particularly limited. Specific examples of the foam stabilizer include silicone compounds such as organopolysiloxane, organopolysiloxane-polyoxyalkylene copolymer, polyalkenylsiloxane having a polyoxyalkylene side chain, silicone-grease copolymer, etc., anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, polyether siloxane, phenolic compounds, etc. These foam stabilizers may be used alone or in combination of two or more. The amount of the foam stabilizer to be added is not particularly limited, but is preferably 0.03 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of the polyol.

[0040] (6) Foaming agent The polyurethane foam composition may contain a blowing agent. The blowing agent is not particularly limited. Suitable blowing agents include water, pentane, cyclopentane, hexane, cyclohexane, dichloromethane, and carbon dioxide gas. When the blowing agent is water, the amount added is determined within a range that allows the polyurethane foam to have a desired density and a good foaming state, and is usually preferably 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of polyol.

[0041] (7) Isocyanate The isocyanate is not particularly limited. At least one selected from the group consisting of aromatic isocyanates, alicyclic isocyanates, and aliphatic isocyanates is preferably used. One or more aliphatic isocyanates and one or more aromatic isocyanates may be used in combination. The isocyanate may be a bifunctional isocyanate having two isocyanate groups in one molecule, or a trifunctional or higher isocyanate having three or more isocyanate groups in one molecule, and may be used alone or in combination. For example, bifunctional isocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, and 3,3'-dimethoxy-4,4'-biphenylene diisocyanate. Examples of the isocyanate include aromatic isocyanates such as ylene diisocyanate, alicyclic isocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexane diisocyanate, and aliphatic isocyanates such as butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, and lysine isocyanate. Examples of tri- or higher functional isocyanates include 1-methylbenzene-2,4,6-triisocyanate, 1,3,5-trimethylbenzene-2,4,6-triisocyanate, biphenyl-2,4,4'-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2',5,5'tetraisocyanate, triphenylmethane-4,4',4"-triisocyanate, and polymeric MDI. Additionally, urethane prepolymers, carbodiimide-modified isocyanates, isocyanurate-modified isocyanates, and biuret-modified isocyanates can also be used.

[0042] The mixing ratio of isocyanate and polyol is not particularly limited. The isocyanate index is preferably 80 or more and 120 or less. The isocyanate index (INDEX) is the value obtained by multiplying the number of moles of isocyanate groups per mole of active hydrogen groups contained in the composition by 100, and is calculated by [(isocyanate equivalent in the composition / active hydrogen equivalent in the composition) × 100].

[0043] (8) Other additives The polyurethane foam composition may contain other additives, such as crosslinking agents, plasticizers, fillers, antioxidants, ultraviolet absorbers, defoamers, compatibilizers, colorants, stabilizers, antibacterial agents, antifungal agents, deodorizers, deodorizers, fragrances, and flavorings, as appropriate. Examples of crosslinking agents include short-chain diol crosslinking agents such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, glycerin, and trimethylolpropane. Examples of coloring agents include pigments, dyes, and coloring agents.

[0044] (9) Physical properties of polyurethane foam The physical properties of the polyurethane foam can be appropriately set depending on the application, etc. The polyurethane foam is preferably a flexible polyurethane foam. The polyurethane foam preferably has the following physical properties: (9.1) Apparent density Apparent density (JISK7222:2005) is 8 kg / m 3 -120kg / m 3 is preferred, and 10 kg / m 3 -80kg / m 3 More preferably, 15 kg / m 3 -45kg / m 3 is more preferred. (9.2) Hardness The hardness (JIS K6400-2:2012 D method) is preferably 10N to 600N, more preferably 40N to 300N, and even more preferably 70N to 150N. If the hardness is within this range, the foam is highly flexible and is preferable as a flexible polyurethane foam. The present inventors have newly discovered a problem that when flame retardancy is ensured by blending only a phosphinic acid ester as a flame retardant, the hardness decreases compared to a polyurethane foam (blank) that does not contain a flame retardant. The technology disclosed herein can ensure flame retardancy while suppressing the decrease in hardness by using a combination of a phosphinic acid ester and a phosphate ester as a flame retardant. (9.3) Rebound Resilience The impact resilience (JIS K6400-3:2011) is preferably 1% to 80%, more preferably 5% to 70%, and even more preferably 15% to 60%. (9.4) Tensile strength, elongation, tear strength The tensile strength (JIS K6400-5:2012, test piece No. 5.2) is preferably 30 kPa or more, more preferably 50 kPa or more, and even more preferably 70 kPa or more. The upper limit of the tensile strength is not particularly limited, and is, for example, 500 kPa or less. The elongation (JIS K6400-5:2012, test piece No. 5.2) is preferably 80% to 500%. If it is 80% or more, the flexibility is high and it is preferable as a flexible polyurethane foam. The tear strength (JIS K6400-5:2012, Method B) is preferably 2.0 N / cm or more, more preferably 3.0 N / cm or more, and even more preferably 4.0 N / cm or more. The upper limit of the tear strength is not particularly limited, and is, for example, 50 N / cm or less. (9.5) Compressive residual strain The compressive set (JIS K6400-4:2004 4.5.2A method) is preferably 20% or less, more preferably 10% or less, and even more preferably 6% or less. The lower limit of the compressive set is not particularly limited, and is, for example, 0% or more. (9.6) Airflow The ventilation rate (JIS K6400-7 Method A: 2012) is preferably 25 L / min or more, more preferably 40 L / min or more, and even more preferably 60 L / min or more. The ventilation rate is usually 300 L / min or less.

[0045] 2. Polyurethane foam manufacturing Polyurethane foams can be produced by a known foaming method in which a polyurethane foam composition is stirred and mixed to react a polyol with an isocyanate. Foaming methods include slab foaming and mold foaming, and either method may be used. Slab foaming is a method in which a mixed polyurethane foam composition is discharged onto a belt conveyor and foamed at atmospheric pressure and room temperature. On the other hand, mold foaming is a method in which a mixed polyurethane foam composition is filled into a mold (forming die) and foamed within the mold.

[0046] 3. Uses of polyurethane foam The polyurethane foam of this embodiment is used, for example, as a flame-retardant polyurethane foam. The applications of the polyurethane foam are not particularly limited. By using a phosphinic acid ester and a phosphate ester, the polyurethane foam of this embodiment can reduce the amount of halogen-based flame retardants and antimony-based flame retardants used, or can ensure flame retardancy without using halogen-based flame retardants and antimony-based flame retardants. The polyurethane foam of this embodiment is useful for various applications as a flame-retardant polyurethane foam with low environmental and human impact. Furthermore, the polyurethane foam of the present embodiment can ensure various physical properties such as compression set by using a phosphinic acid ester and a phosphoric acid ester, making it suitable for a variety of uses.

[0047] The polyurethane foam of the present embodiment is flame-retardant and therefore suitable for use as a vehicle interior component. The vehicle interior component is not particularly limited. Examples of vehicle interior components include components used for vehicle seats and components used for vehicle interior materials. [Example]

[0048] 1. Polyurethane foam manufacturing Compositions having the blending ratios shown in Tables 1 to 4 were prepared, and polyurethane foams of Reference Example, Working Example, and Comparative Example were produced by slab foaming. The Reference Example is a comparative example that does not contain a phosphinic acid ester. The details of each raw material are as follows: Polyol: Polyether polyol, functionality 3, weight average molecular weight 3000, hydroxyl value 56.1 mg KOH / g, ethylene oxide content 8% by mass Foaming agent: Water Amine catalyst 1: N,N-dimethylaminohexanol Amine catalyst 2: Aliphatic amine catalyst, manufactured by EVONIC, product name NE-300 Foam stabilizer: Silicone foam stabilizer, product name: SZ-1136, manufactured by Dow Corning Toray Isocyanate: Tolylene diisocyanate (mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate) Tin catalyst: tin(II) octoate Phosphinic acid ester: 9,10-dihydro-10-benzyl-9-oxa-10-phosphaphenanthrene-10-oxide (CAS No. 113504-81-7), Sanko Co., Ltd., product name BCA, corresponding to the compound of formula (2) above. Phosphate ester 1: Resorcinol bis-dixylenyl phosphate (RDX) (CAS No. 139189-30-3), Daihachi Chemical Industry Co., Ltd., product name PX-200 Phosphate ester 2: Resorcinol bis-diphenyl phosphate (RDP) (CAS No. 125997-21-9), Daihachi Chemical Industry Co., Ltd., product name CR-733S Phosphate ester 3: Cresyl diphenyl phosphate (CDP) (CAS No. 26444-49-5), Lanxess, product name Disflamoll DPK Phosphate ester 4: Bisphenol A bis(diphenyl phosphate) (BDP) (CAS No. 181028-79-5), Daihachi Chemical Industry Co., Ltd., product name CR-741 Phosphate ester 5: Halogen-containing condensed phosphate ester, Daihachi Chemical Industry Co., Ltd., product name CR-504L

[0049] Specifically, the polyurethane foam was produced by the following procedure. The raw materials other than the isocyanate were weighed and stirred in a cup container to prepare a mixed solution. An isocyanate was added to the mixed solution, and the mixture was stirred to prepare a composition.

[0050] [Table 1]

[0051] [Table 2]

[0052] [Table 3]

[0053] [Table 4]

[0054] The properties of phosphinate ester and phosphate ester 1-phosphate ester 5 are summarized in Table 5. Table 5 also lists the results of the following experimental examples for phosphinate ester and phosphate ester 1-phosphate ester 5 regarding "reactivity," "physical properties," and "flame retardancy," which will be described later. Phosphinic acid ester (BCA): Comparative Example 4 Phosphate ester 1 (RDX): Comparative Example 7 Phosphate ester 2 (RDP): Comparative Example 9 Phosphate ester 3 (CDP): Comparative Example 11 Phosphate ester 4 (BDP): Comparative Example 13 Phosphate ester 5 (halogen-containing condensed phosphate ester): Reference example [Table 5]

[0055] 2. Evaluation Method (1) Apparent density (density) The apparent density was measured according to JIS K7222:2005. (2) Hardness (25% ILD hardness) The hardness was measured according to JIS K6400-2:2012 D method. In addition, for Comparative Examples 10, 11, and 13 to 15, the 25% CLD hardness was measured according to ASTM D 3574-11. The 25% CLD hardness is shown with "( )" next to the numerical value. (3) Rebound elasticity The impact resilience was measured according to JIS K6400-3:2011. (4) Tensile strength, elongation, tear strength The tensile strength was measured using a test piece No. 5.2 according to JIS K6400-5:2012. Elongation was measured using JIS K6400-5:2012, test piece No. 5.2. The tear strength was measured according to JIS K6400-5:2012, Method B. (5) Compressive residual strain The compressive set was measured in accordance with JIS K6400-4 4.5.2A method:2004, under 50% compression, at 70°C, for 22 hours. (6) Ventilation The air permeability was measured according to JIS K6400-7 Method A.

[0056] (7) Combustion test Combustion test specimens (N=5) were cut from the polyurethane foams of the Reference Examples, Comparative Examples, and Examples. Each combustion test specimen was subjected to a combustion test in accordance with the flame retardancy standard UL94HF-1 of the Underwriters Laboratory in the United States. In the UL94HF-1 test, the combustion test specimen was placed on a wire mesh and exposed to a gas burner so that the flame reached the entire edge (2 inches wide) of the specimen.

[0057] The items in Table 1-4 are as follows: Total amount of flame retardant added: The total amount of flame retardant added (parts by mass) per 100 parts by mass of polyol Burning distance: The burning distance (mm) from the end of the test specimen was measured, and the average value of five burning test specimens was calculated. Afterflame time: The burning time (seconds) from 60 seconds after flame application until the flame was extinguished was measured, and the average value of five burning test pieces was calculated. Ignition: The number of ignited test specimens was counted. In Table 1-4, the number of ignited test specimens / total number of test specimens is shown. HF-1 evaluation: If the product passed the flame retardant standard UL94HF-1, it was rated as "OK", and if it failed, it was rated as "NG".

[0058] (8) Reactivity The reactivity of the polyurethane foam was evaluated. If the reactivity was good, it was marked as "good," and if it was poor, it was marked as "poor" and the possible reasons for the poor reactivity were noted. (9) Physical properties The compressive residual strain, which is an index of physical properties, was evaluated according to the following criteria. A: 6% or less B: More than 6% and less than 10% C: More than 10% and less than 20% D: Greater than 20% (10) Flame retardant The HF-1 rating was evaluated according to the following criteria. Pass: HF-1 judgment Pass Fail: HF-1 judgment Fail (11)Environment The environmental impact was evaluated according to the following criteria. Suitable: No halogen-based flame retardants are used Unsuitable: Uses halogen-based flame retardants

[0059] 3.Results The evaluation results are shown in Table 1-4. The flame retardants of Examples 1 to 5 contain phosphinic acid ester and phosphoric acid ester. The polyurethane foams of Examples 1 to 5 were evaluated as "A" for physical properties. The polyurethane foams of Examples 1 to 5 were evaluated as "pass" for flame retardancy. It was found that Examples 1 to 5 have both physical properties and flame retardancy and are suitable for practical use.

[0060] In contrast, the flame retardant of Comparative Example 1 does not contain either a phosphinic acid ester or a phosphoric acid ester. The polyurethane foam of Comparative Example 1 was evaluated as "fail" in terms of flame retardancy. The flame retardants of Comparative Examples 2 to 5 contained only phosphinic acid esters and did not contain phosphoric acid esters. The polyurethane foams of Comparative Examples 2 to 4 were evaluated as "fail" in terms of flame retardancy. The polyurethane foam of Comparative Example 5 was evaluated as "B" in terms of physical properties. The flame retardants of Comparative Examples 6 to 14 did not contain a phosphinic acid ester, but contained only a phosphoric acid ester. The polyurethane foams of Comparative Examples 6 to 14 were evaluated as "fail" in terms of flame retardancy. It was found that Comparative Examples 1 to 14 were not suitable for practical use.

[0061] This will be examined in detail below. The Reference Example is an example in which 20 parts by mass of a halogen-based flame retardant was added. The burning distance of the Reference Example was 45 mm. The Reference Example was rated "A" for physical properties and "passed" for flame retardancy. However, the use of a halogen-based flame retardant in the Reference Example raises concerns about the burden on the environment and human body.

[0062] Comparative Example 1 is an example (blank) that does not contain a flame retardant. The burning distance of Comparative Example 1 was 125 mm, and the flame retardancy evaluation was "fail."

[0063] Comparative Examples 2 to 5 are examples in which phosphinic acid ester (BCA) was added in amounts of 5 parts by mass, 10 parts by mass, 20 parts by mass, and 25 parts by mass. The burning distances of Comparative Examples 2 to 5 were 125 mm, 125 mm, 75 mm, 55 mm, and 45 mm. Only Comparative Example 5 was evaluated as "pass" in flame retardancy. Comparative Example 5 was evaluated as "B" in physical properties.

[0064] Comparative Examples 6 to 14 are examples in which only a phosphate ester was used as the flame retardant. In all cases, the burning distance was 61 mm or more, and the flame retardancy rating was "fail."

[0065] In Examples 1 and 2, 5 parts by mass and 10 parts by mass of phosphoric acid ester 1 (RDX) were added in addition to 10 parts by mass of phosphinic acid ester. The burning distances were 39 mm and 34 mm, respectively, and the flame retardancy rating was "pass." Example 3 is an example in which 10 parts by mass of phosphoric acid ester 2 (RDP) was added in addition to 10 parts by mass of phosphinic acid ester. The burning distance was 37 mm, and the flame retardancy was evaluated as "pass." In Examples 4 and 5, 5 parts by mass and 10 parts by mass of phosphoric acid ester 3 (CDP) were added in addition to 10 parts by mass of phosphinic acid ester. The burning distances were 32 mm and 36 mm, respectively, and the flame retardancy rating was "pass."

[0066] According to the above examples, flame retardancy was ensured without using halogen-based flame retardants or antimony-based flame retardants. It was also confirmed that flame retardants containing phosphinate esters and phosphate esters can be used as substitutes for halogen-based flame retardants. It was also suggested that the use of flame retardants containing phosphinate esters and phosphate esters can enable the production of polyurethane foams with better physical properties.

[0067] The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the present disclosure.

Claims

1. A polyurethane foam obtained from a composition comprising a polyol, a polyisocyanate, and a flame retardant, The flame retardant comprises a phosphinate ester and a phosphate ester.

2. The polyurethane foam according to claim 1 , wherein the flame retardant comprises a compound represented by the following chemical formula (1) as the phosphinic acid ester: 【Chemistry 1】 (In the formula, R １ and R ２ each independently represents a hydrocarbon group which may have a substituent other than halogen; each n independently represents an integer of 0 to 4; R ３ is a hydrocarbon group which may have a substituent other than a halogen and does not have a hydroxyl group.

3. 3. The polyurethane foam according to claim 1, wherein the phosphate ester is an aromatic phosphate ester.

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