Polyurethane foam

Abstract

To reduce VOCs in polyurethane foam.SOLUTION: A polyurethane foam is obtained from a composition that is a mixture of a polyol, a catalyst, a flame retardant, and an isocyanate. The composition includes at least one compound selected from the group consisting of alkali metal salts, alkali metal hydroxides, alkaline-earth metal salts, and alkaline-earth metal hydroxides.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to polyurethane foam. [Background technology]

[0002] Technologies for suppressing volatile organic compounds (VOCs) in polyurethane foams are being investigated. Technologies for suppressing VOCs include using antioxidants and ozone degradation inhibitors of polymer compounds having a certain number-average molecular weight or higher, and technologies that use tin ricinoleate or high molecular weight tin carboxylate catalysts instead of the commonly used tin 2-ethylhexanoate. For example, Patent Document 1 discloses a technique that uses a polymer compound having a certain number-average molecular weight or higher as an antioxidant. Furthermore, Patent Document 2 discloses a technology that uses polymer compounds having a molecular weight above a certain level as antioxidants and ozone degradation inhibitors. Furthermore, Patent Document 3 discloses a technique using tin salts of carboxylic acids having 12-16 carbon atoms. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2004-211032 [Patent Document 2] Japanese Patent Publication No. 2004-231949 [Patent Document 3] Japanese Patent Publication No. 2010-275551 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the techniques described in these documents had a problem in that, in the VOC measurement method specified in "German Association of the Automotive Industry VDA278," Patent Document 1 and Patent Document 2 detected a large amount of VOCs such as 2-ethylhexanoic acid. Furthermore, in Patent Document 3, which uses tin ricinoleate, it was necessary to add more than twice the amount compared to tin 2-ethylhexanoate to obtain equivalent physical properties, which resulted in higher costs. This disclosure is made in view of the above circumstances and aims to reduce VOCs in polyurethane foam. This disclosure can be implemented in the following forms. [Means for solving the problem]

[0005] Polyols and, Catalyst and Flame retardant and Isocyanates and, A polyurethane foam obtained from a mixed composition, The composition comprises one or more compounds selected from the group consisting of alkali metal salts, alkali metal hydroxides, alkaline earth metal salts, and alkaline earth metal hydroxides, in a polyurethane foam. [Effects of the Invention]

[0006] According to this disclosure, the VOCs of polyurethane foam can be reduced. [Modes for carrying out the invention]

[0007] Herein lies a preferred example of this disclosure. • Polyols and, Catalyst and Isocyanates and, A polyurethane foam obtained from a mixed composition, The composition comprises one or more compounds selected from the group consisting of alkali metal salts of hydroxycarboxylic acids and alkaline earth metal salts of hydroxycarboxylic acids, in a polyurethane foam. A polyurethane foam comprising the above composition, wherein the compound is present in an amount of 0.003 parts by mass or more and 3 parts by mass or less per 100 parts by mass of the polyol. The catalyst is a polyurethane foam containing a metal catalyst. • Polyurethane foam in which the total VOC value is less than 200 ppm, according to the VOC measurement method specified in the German Association of the Automotive Industry (VDA) 278, which is an indicator of the suppression of volatile organic compound emissions. Furthermore, the total VOC value is preferably less than 150 ppm, more preferably less than 100 ppm, and even more preferably less than 40 ppm. • A polyurethane foam with flame retardancy that meets the US automotive safety standard (FMVSS-302). Flame-retardant polyurethane foam in which one or more elements selected from the group consisting of alkali metals and alkaline earth metals are detected by qualitative analysis.

[0008] The disclosure is described in detail below. In this specification, when a numerical range is indicated using "-", it includes both the lower and upper limits 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".

[0009] 1. Polyurethane foam (Part 1) Polyurethane foam is obtained from a composition (hereinafter also referred to as "polyurethane resin composition") which is a mixture of polyol, a catalyst, a flame retardant, and an isocyanate. The polyurethane resin composition contains one or more compounds selected from the group consisting of alkali metal salts, alkali metal hydroxides, alkaline earth metal salts, and alkaline earth metal hydroxides.

[0010] (1) Polyol The polyol is not particularly limited. Various polyols may be used individually or in combination of two or more. Examples of polyols include polyether polyols, polyether ester polyols, polyester polyols, polycarbonate diols, and polyols with a carbon-carbon bond in the main chain. Polyether polyols include, for example, polyoxypropylene·polyoxyethylene polyols, polymer polyols, and polyoxytetramethylene glycols. Polyester polyols include, for example, aliphatic or aromatic polycondensation polyester polyols and polycaprolactone polyols. Polyols with a carbon-carbon bond main chain include, for example, polyolefin polyols such as polybutadiene polyol and isoprene polyol, and acrylic polyols.

[0011] (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 initiator (compounds), or polytetramethylene ether glycol.

[0012] (1.1.1) Initiator (1.1.1.1) Polyhydric alcohols and alkylene oxide adducts of polyhydric alcohols Examples of polyhydric alcohols: [Difunctional alcohol] Ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, trimethylene glycol [Trifunctional alcohol] Glycerol, 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) Polyhydric hydroxy compounds Examples of polyhydric hydroxy compounds: phosphate, benzenephosphate, polyphosphate (e.g., tripolyphosphate and tetrapolyphosphate), etc. (1.1.1.4) Phenol-aniline-formaldehyde ternary condensation product (1.1.1.5) Aniline-formaldehyde condensation product (1.1.1.6) Polyamines Examples of polyamines: ethylenediamine, diethylenetriamine, triethylenetetramine, methylenebisorthochloraniline, 4,4- and 2,4'-diphenylmethanediamine, 2,4-tolylenediamine, 2,6-tolylenediamine, etc. (1.1.1.7) Alkanolamines Examples of alkanolamines: triethanolamine, diethanolamine, etc.

[0013] (1.1.2) Polymer polyols Polymer polyols are polyols obtained by graft polymerization of ethylenically unsaturated compounds such as acrylonitrile, styrene, and alkyl methacrylate onto the polyether polyols described above.

[0014] (1.2) Polyether ester polyol Examples of polyether ester polyols include compounds obtained by reacting polyoxyalkylene polyols with polycarboxylic acid anhydrides and compounds having cyclic ether groups. Polyurethane foams using polyether ester polyols are useful, for example, as polyurethane foams for frame lamination. Examples of polyoxyalkylene polyols: polyethylene glycol, polypropylene glycol, propylene oxide adducts of glycerin, etc. Examples of polycarboxylic acid anhydrides: succinic acid, adipic acid, phthalic acid, trimellitic acid, etc. Examples of compounds containing cyclic ether groups: ethylene oxide, propylene oxide, etc. (1.3) Polyester polyol Polyester polyols are 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 are ring-opening polymers of cyclic esters such as caprolactone and methylvalerolactone.

[0015] (1.3.1) Examples of compounds having at least two hydroxyl groups Ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,3- and 1,4-butanediol, tetramethylene glycol, neopentyl glycol, methylpentanediol, butylethylpropanediol, hexamethylene glycol, decamethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol

[0016] (1.3.2) Examples of compounds having at least two carboxyl groups Malonic acid, maleic acid, succinic acid, adipic acid, tartaric acid, pimelic acid, azelaic acid, sebacic acid, oxalic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, hemeltic acid

[0017] (1.4) Polycarbonate diol Examples of polycarbonate polyols include those obtained by transesterification reactions between low molecular weight polyols such as butanediol and hexanediol and low molecular weight carbonates such as propylene carbonate and diethyl carbonate.

[0018] (1.5) Polyolefin-based polyols Examples of polyolefin-based polyols include polybutadiene polyols, polyisoprene polyols, hydrogenated polybutadiene polyols, and hydrogenated polyisoprene polyols.

[0019] (1.6) Plant-derived polyols In addition to the polyols mentioned above, plant-derived polyols may also be included as polyols. Examples of plant-derived polyols include castor oil polyols, soybean oil polyols, palm oil polyols, palm kernel oil polyols, coconut oil polyols, cashew oil polyols, olive oil polyols, cottonseed oil polyols, safflower oil polyols, sesame oil polyols, sunflower oil polyols, and linseed oil polyols. Plant-derived polyols typically have 2-3 hydroxyl functional groups per molecule. Examples of castor oil-based polyols include castor oil, reaction products of castor oil and polyols, and esterification reaction products of castor oil fatty acids and polyols. Examples of polyols to be reacted with castor oil or castor oil fatty acids include divalent polyols such as ethylene glycol, diethylene glycol, and propylene glycol, or trivalent or higher polyols such as glycerin, trimethylolpropane, hexanetriol, and sorbitol. Examples of soybean oil-based polyols include polyols derived from soybean oil, such as reaction products of soybean oil and polyols, and esterification reaction products of soybean oil fatty acids and polyols. The polyols used to react with soybean oil or soybean oil fatty acids can be the same as those used for castor oil. The same applies to palm oil-based polyols, cashew oil-based polyols, etc., as to soybean oil-based polyols. The various polyols exemplified as plant-derived polyols may be used individually or in combination of two or more.

[0020] (2) Catalyst Conventional known catalysts can be used without any particular limitations. Various catalysts may be used individually or in combination of two or more. Amine catalysts and quaternary ammonium salt catalysts can be used as catalysts. Specific examples of these catalysts are shown below. Tertiary amine catalysts such as triethylenediamine, triethylamine, tripropylamine, triisopropanolamine, tributylamine, trioctylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, monoethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N,N-dimethylethanolamine, N,N-dimethylaminohexanol, N,N-dimethylaminoethoxyethoxyethanol, and N,N-dimethylaminoethoxyethanol can be used, as well as formate and other salts of triethylenediamine, oxyalkylene adducts of amino groups of primary and secondary amines, aza ring compounds such as NN-dialkylpiperazines, various N,N',N'-trialkylaminoalkylhexahydrotriazines, and amine catalysts having an amino group as a functional group such as N,N,N",N"-tetramethyldiethylenetriamine can be employed. Furthermore, quaternary ammonium salt catalysts such as tetraalkylammonium halides including tetramethylammonium chloride, tetraalkylammonium hydroxides including tetramethylammonium hydroxide, and tetraalkylammonium organic acid salts such as tetramethylammonium 2-ethylhexanoate, 2-hydroxypropyltrimethylammonium forate, 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 resin composition is not particularly limited. From the viewpoint of sufficiently promoting the polyurethane formation 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 various physical properties of the polyurethane foam and from the viewpoint of manufacturing costs, it 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.

[0021] A metal catalyst (organometallic catalyst) can be used as the catalyst. Any conventionally known metal catalyst can be used without any particular limitations. As metal catalysts, for example, metal salts of Sn (tin), Pb (lead), Bi (bismuth), Ni (nickel), Co (cobalt), Fe (iron), Zr (zirconium), Cu (copper), Zn (zinc), etc., as well as metal salts of organic acids, can be used. More specifically, the following metal catalysts can be used. Sn catalysts: Tin(II) octyolate (2-ethylhexanoate tin, stanas dioctoate), tin(II) acetate, stanas diacetate, tin(II) octanoate, tin stanas dioleate, tin(II) neodecanoate stanas dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dioctyltin dilaurate, dibutyltin dimaleate, dioctyltin diacetate, etc. Pb catalysts: Lead octanoate, lead naphthenate, etc. Bi catalysts: Bismuth octylate, bismuth naphthenate, bismuth neodecanoate, bismuth rosinate, etc. Fe catalyst: Iron acetylacetonate, etc. Zr catalyst: Zirconium acetylacetonate, etc. Ni catalysts: Nickel acetylacetonate, nickel octylate, nickel naphthenate, etc. Co catalysts: Cobalt acetylacetonate, cobalt octylate, cobalt naphthenate, etc.

[0022] The amount of metal catalyst blended in a polyurethane resin composition is not particularly limited. From the viewpoint of sufficiently promoting the polyurethane formation reaction, the amount of metal catalyst blended 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 (such as 2-ethylhexanoic acid) derived from the metal catalyst, the amount is preferably 1.0 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.30 parts by mass or less. From these viewpoints, the amount of metal catalyst blended is preferably 0.01 parts by mass or more and 1.0 part by mass or less, more preferably 0.05 parts by mass or more and 0.5 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.3 parts by mass or less, per 100 parts by mass of polyol.

[0023] (3) Flame retardants The flame retardant is not particularly limited. Examples of flame retardants include halogenated flame retardants, phosphorus-based flame retardants, and inorganic flame retardants. Each type of flame retardant may be used individually or in combination of two or more types.

[0024] As a halogen-based flame retardant, a flame retardant containing a halogen compound and antimony oxide is preferred. Of the flame retardants containing a halogen compound and antimony oxide, a flame retardant consisting of polyvinyl chloride, antimony oxide, and zinc oxide is more preferred due to its high flame retardancy. As a halogen compound, in addition to polyvinyl chloride, those with a high chlorine content of 40-70%, such as chlorinated paraffin, are preferred due to their excellent flame retardancy. As an antimony oxide, there are antimony trioxide and antimony pentoxide, but antimony trioxide is preferred because it is inexpensive and highly versatile. In that case, the amount of polyvinyl chloride in the halogen-based flame retardant is 5-70 parts by mass, antimony oxide is 1-30 parts by mass, and zinc oxide is 1-15 parts by mass. Furthermore, the mass ratio of the halogen compound to antimony oxide is preferably 1:1-4:1.

[0025] Aliphatic condensed phosphate esters are preferred as phosphorus-based flame retardants. Aliphatic condensed phosphate esters include alkyl phosphates exhibiting oligomeric form, specifically oligomeric ethylethylene phosphate, modified oligomeric ethylethylene phosphate, and formulations mainly composed of oligomeric ethylethylene phosphate. Such aliphatic condensed phosphate esters are also commercially available, and for example, "Fyrol PNX-LE" (manufactured by ICL JAPAN Co., Ltd.), "Fyrol PNX" (manufactured by ICL JAPAN Co., Ltd.), "Fyrol HF-5" (manufactured by ICL JAPAN Co., Ltd.), and "DAIGUARD-880" (manufactured by Daihachi Chemical Industry Co., Ltd.) can be used.

[0026] The amount of flame retardant added to the polyurethane resin composition is not particularly limited. From the viewpoint of imparting flame retardancy, the amount of flame retardant added is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 1 part by mass or more, per 100 parts by mass of polyol. On the other hand, from the viewpoint of foaming stability, low fogging, low staining, and flame lamination properties when performing flame lamination, it is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less. From these viewpoints, the amount of flame retardant added is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 0.5 parts by mass or more and 25 parts by mass or less, and even more preferably 1 part by mass or more and 20 parts by mass or less, per 100 parts by mass of polyol.

[0027] From the viewpoint of suppressing discoloration caused by the inclusion of flame retardants, it is preferable that at least one organic compound selected from benzothiazole compounds, dithiocarbamate compounds, and sulfenamide compounds be blended together with the flame retardant. Examples of benzothiazole compounds include 2-mercaptobenzothiazole (abbreviated as MBT in the Japan Rubber Association Standards) and di-2-benzothiazolyl disulfide (also MBTS). Examples of dithiocarbamate compounds include zinc diethyldithiocarbamate (also ZnEDC), zinc dimethyldithiocarbamate (also ZnMDC), zinc dibutyldithiocarbamate (also ZnBDC), copper dimethyldithiocarbamate (also CuMDC), and ferric dimethyldithiocarbamate (also FeMDC). Examples of sulfenamide compounds include N-cyclohexyl-2-benzothiazolyl sulfenamide (also CBS) and N-oxydiethylene-2-benzothiazolyl sulfenamide (also OBS). The amount of the above organic compound is preferably 0.5 parts by mass or more and 3.0 parts by mass or less per 100 parts by mass of polyol.

[0028] (4) Foam stabilizer (optional ingredient) The foam stabilizer is an optional component and is not particularly limited. Specifically, foam stabilizers include silicone compounds such as organopolysiloxanes, organopolysiloxane-polyoxyalkylene copolymers, polyalkenylsiloxanes having polyoxyalkylene side chains, and silicone-grease copolymers; anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate; polyethersiloxanes; and phenolic compounds. These foam stabilizers may be used individually or in combination of two or more. The amount of foam stabilizer added is not particularly limited. Preferably, the amount of foam stabilizer added is 0.03 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of polyol.

[0029] (5) Foaming agent (optional ingredient) The blowing agent is an optional component and is not particularly limited. Suitable blowing agents include water, pentane, cyclopentane, hexane, cyclohexane, dichloromethane, and carbon dioxide. When water is used as the blowing agent, the amount added is determined to obtain the desired density and good foaming state in the polyurethane foam, and is usually preferably 1 to 10 parts by mass per 100 parts by mass of polyol.

[0030] (6) Isocyanates (polyisocyanates) The isocyanate is not particularly limited. Preferably, at least one isocyanate selected from the group consisting of aromatic isocyanates, alicyclic isocyanates, and aliphatic isocyanates. One or more aliphatic isocyanates and one or more aromatic isocyanates may be used in combination. Furthermore, the isocyanate may be a bifunctional isocyanate having two isocyanate groups in one molecule, or a trifunctional or more isocyanate having three or more isocyanate groups in one molecule, and may be used alone or in combination of several. For example, difunctional isocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylenediisocyanate, p-phenylenediisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylenediisocyanate, and 3,3'-dimethoxy-4,4'-biphenyl Examples include aromatic isocyanates such as nitrile 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, isopropyl diisocyanate, methylene diisocyanate, and lysine isocyanate. Furthermore, examples of isocyanates with three or more functions include 1-methylbenzol-2,4,6-triisocyanate, 1,3,5-trimethylbenzol-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, polymeric MDI, and the like. In addition, other urethane prepolymers, carbodiimide-modified isocyanates, isocyanurate-modified isocyanates, and burette-modified isocyanates can also be used.

[0031] The mixing ratio of isocyanate and polyol is not particularly limited. The isocyanate index is preferably between 80 and 120. 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 polyurethane resin composition by 100, and is calculated as [(equivalent amount of isocyanate in the composition / equivalent amount of active hydrogen in the composition) × 100].

[0032] (7) One or more compounds selected from the group consisting of alkali metal salts, alkali metal hydroxides, alkaline earth metal salts, and alkaline earth metal hydroxides. (7.1) Alkali metal salts and alkali metal hydroxides Examples of alkali metals that make up alkali metal salts and alkali metal hydroxides include potassium (K), sodium (Na), and lithium (Li). The alkali metal salt may be a potassium salt, a sodium salt, or a lithium salt. The alkali metal hydroxide may be potassium hydroxide, sodium hydroxide, or lithium hydroxide.

[0033] Alkali metal salts are preferred for hydroxycarboxylic acids because they are less prone to scorching discoloration, have little effect on the hardness of physical properties (hardness reduction), and have fewer odor problems compared to potassium acetate, etc. Hydroxycarboxylic acids are compounds that have both a hydroxyl group and a carboxyl group in their molecule. In this disclosure, lactones, which are cyclic compounds formed by intramolecular dehydration condensation of the hydroxyl and carboxyl groups of a hydroxycarboxylic acid, and lactides, which are cyclic compounds formed by dehydration condensation of the hydroxyl and carboxyl groups of two molecules of hydroxycarboxylic acids, are also included as hydroxycarboxylic acids. Examples of hydroxycarboxylic acids include lactic acid, glycolic acid, propionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, 2-hydroxyethoxyacetic acid, 1,3-propanediol, 1-carbonate and their derivatives, lactones formed by intramolecular dehydration condensation of one or more of these, and lactides formed by intermolecular dehydration condensation of one or more of these. One or more of these hydroxycarboxylic acids can be used.

[0034] Potassium salts are not particularly limited. Examples of potassium salts include inorganic and organic salts such as potassium carbonate, potassium acetate, potassium benzoate, potassium chloride, potassium oxalate, potassium bicarbonate, potassium thiocyanate, tripotassium phosphate, dipotassium hydrogen phosphate, potassium laurate, potassium succinide, dipotassium adipate, and dipotassium malonate, from the viewpoint of having a high scavenging effect on volatile organic compounds such as 2-ethylhexanoic acid. Among these, one or more compounds selected from the group consisting of potassium carbonate and potassium acetate are preferred. The sodium salt is not particularly limited. Examples of sodium salts that have a high scavenging effect on volatile organic compounds such as 2-ethylhexanoic acid include sodium lactate, sodium carbonate, sodium benzoate, sodium chloride, sodium acetate, sodium oxalate, sodium bicarbonate, trisodium phosphate, sodium bicarbonate, sodium succinate, and disodium malonate. Among these, one or more compounds selected from the group consisting of sodium lactate and sodium carbonate are preferred. Lithium salts are not particularly limited. Examples of lithium salts that have a high scavenging effect on volatile organic compounds such as 2-ethylhexanoic acid include lithium benzoate, lithium chloride, lithium acetate, lithium oxalate, lithium carbonate, lithium bicarbonate, lithium thiocyanate, lithium phosphate, and lithium hydrogen phosphate.

[0035] (7.2) Alkaline earth metal salts and alkaline earth metal hydroxides Examples of alkaline earth metals that make up alkaline earth metal salts and alkaline earth metal hydroxides include calcium (Ca) and magnesium (Mg). The alkaline earth metal salt may be either a calcium salt or a magnesium salt. The hydroxide of the alkaline earth metal salt may be either calcium hydroxide or magnesium hydroxide.

[0036] Alkaline earth metal salts are preferred as alkaline earth metal salts of hydroxycarboxylic acids, from the viewpoint of having fewer odor problems compared to calcium acetate, etc. Hydroxycarboxylic acids are compounds that have both a hydroxyl group and a carboxyl group in their molecule. In this disclosure, lactones, which are cyclic compounds obtained by intramolecular dehydration condensation of the hydroxyl group and carboxyl group of a hydroxycarboxylic acid, and lactides, which are cyclic compounds obtained by dehydration condensation of the hydroxyl group and carboxyl group of two molecules of hydroxycarboxylic acid, are also included as hydroxycarboxylic acids. Examples of hydroxycarboxylic acids include lactic acid, glycolic acid, propionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, 2-hydroxyethoxyacetic acid, 1,3-propanediol, 1-carbonate and their derivatives, lactones obtained by intramolecular dehydration condensation of one or more of these, and lactides obtained by intermolecular dehydration condensation of one or more of these, and one or more of these hydroxycarboxylic acids can be used.

[0037] The calcium salt is not particularly limited. Examples of calcium salts include calcium lactate, calcium acetate, calcium benzoate, calcium chloride, calcium bicarbonate, and calcium dihydrogen phosphate, from the viewpoint of their high scavenging effect on volatile organic compounds such as 2-ethylhexanoic acid. Among these, one or more compounds selected from the group consisting of calcium lactate and calcium acetate are preferred. The magnesium salt is not particularly limited. From the viewpoint of having a high scavenging effect on volatile organic compounds such as 2-ethylhexanoic acid, one or more compounds selected from the group consisting of magnesium chloride and magnesium acetate are preferred as the magnesium salt.

[0038] (7.3) Solubility in water of one or more compounds selected from the group consisting of alkali metal salts, alkali metal hydroxides, alkaline earth metal salts, and alkaline earth metal hydroxides (hereinafter also referred to as "the compound") The solubility of the compound in water is not particularly limited. From the viewpoint of improving the dispersibility of the ions in the raw material solution and polyurethane foam and enhancing the scavenging effect of volatile organic compounds such as 2-ethylhexanoic acid, the solubility of the compound in 100g of water at 20°C is preferably 1g or more, more preferably 5g or more, and even more preferably 10g or more. There is no particular upper limit to the solubility of the compound in 100g of water at 20°C, but it is usually 300g. The solubility of the compound in 100g of water at 20°C is preferably 1g or more and 300g or less, more preferably 5g or more and 300g or less, and even more preferably 10g or more and 300g or less.

[0039] (7.4) Amount of one or more compounds selected from the group consisting of alkali metal salts, alkali metal hydroxides, alkaline earth metal salts, and alkaline earth metal hydroxides ("the compound") in the polyurethane resin composition. The amount of the compound blended in the polyurethane resin composition is not particularly limited and is acceptable as long as it is blended. From the viewpoint of sufficiently capturing volatile organic compounds such as 2-ethylhexanoic acid, the amount of the compound blended is preferably 0.003 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.025 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 manufacturing costs, it is preferably 3.0 parts by mass or less, more preferably 2.0 parts by mass or less, and even more preferably 1.0 part by mass or less. From these viewpoints, the amount of the compound blended is preferably 0.003 parts by mass or more and 3.0 parts by mass or less, more preferably 0.01 parts by mass or more and 2.0 parts by mass or less, and even more preferably 0.025 parts by mass or more and 0.1 parts by mass or less, per 100 parts by mass of polyol. Furthermore, the capture mechanism described later is influenced by the ratio of the compound to the metal catalyst, tin octoate (tin compound). In other words, the degree to which VOC generation is suppressed is influenced by this ratio. Therefore, from this viewpoint, the amount of the compound is preferably 0.1 mole or more, more preferably 0.2 mole or more, and even more preferably 0.5 mole or more per 1.0 mole of tin octoate (tin compound). On the other hand, from the viewpoint of maintaining the various physical properties of the polyurethane foam and from the viewpoint of manufacturing costs, it is preferably 10.0 mole or less, more preferably 5.0 mole or less, and even more preferably 3.0 mole or less. From these viewpoints, the amount of alkali metal salt blended is preferably 0.1 mole or more and 10.0 mole or less, more preferably 0.2 mole or more and 5.0 mole or less, and even more preferably 0.5 mole or more and 3.0 mole or less per 1 mole of tin octoate (tin compound).

[0040] (7.5) Amount of one or more compounds selected from the group consisting of alkali metal salts and alkali metal hydroxides (hereinafter also referred to as "alkali metal salts, etc.") in the polyurethane resin composition. The amount of alkali metal salts, etc., blended in the polyurethane resin composition is not particularly limited and is acceptable as long as they are blended. From the viewpoint of sufficiently capturing volatile organic compounds such as 2-ethylhexanoic acid, the amount of alkali metal salts, etc., is preferably 0.003 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.025 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 manufacturing costs, it is preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, and even more preferably 0.2 parts by mass or less. From these viewpoints, the amount of alkali metal salts, etc., blended is preferably 0.003 parts by mass or more and 0.4 parts by mass or less, more preferably 0.01 parts by mass or more and 0.3 parts by mass or less, and even more preferably 0.025 parts by mass or more and 0.2 parts by mass or less, per 100 parts by mass of polyol. Furthermore, the capture mechanism described later is influenced by the ratio of alkali metal salts, etc., to tin octoate (tin compound), which is a metal catalyst. In other words, the degree to which VOC generation is suppressed is influenced by this ratio. Therefore, from this viewpoint, the amount of alkali metal salts, etc., is preferably 0.1 moles or more, more preferably 0.2 moles or more, and even more preferably 0.5 moles or more per 1.0 mole of tin octoate (tin compound). On the other hand, from the viewpoint of maintaining the various physical properties of polyurethane foam and from the viewpoint of manufacturing costs, it is preferably 10.0 moles or less, more preferably 5.0 moles or less, and even more preferably 3.0 moles or less. From these viewpoints, the amount of alkali metal salts, etc., blended is preferably 0.1 moles or more and 10.0 moles or less, more preferably 0.2 moles or more and 5.0 moles or less, and even more preferably 0.5 moles or more and 3.0 moles or less per 1 mole of tin octoate (tin compound).

[0041] When the alkali metal salt is an alkali metal salt of a hydroxycarboxylic acid, the amount of alkali metal salt, etc., blended in the polyurethane resin composition is not particularly limited and should be included. From the viewpoint of sufficiently capturing volatile organic compounds such as 2-ethylhexanoic acid, the amount of alkali metal salt, etc., is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, and even more preferably 0.03 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 manufacturing costs, it is preferably 0.4 parts by mass or less, more preferably 0.3 parts by mass or less, and even more preferably 0.2 parts by mass or less. From these viewpoints, the amount of alkali metal salt, etc., blended is preferably 0.01 parts by mass or more and 0.4 parts by mass or less, more preferably 0.02 parts by mass or more and 0.3 parts by mass or less, per 100 parts by mass of polyol.

[0042] (7.6) Amount of one or more compounds selected from the group consisting of alkaline earth metal salts and alkaline earth metal hydroxides (hereinafter also referred to as "alkaline earth metal salts, etc.") in the polyurethane resin composition. The amount of alkaline earth metal salts, etc., blended in the polyurethane resin composition is not particularly limited and is acceptable as long as they are blended. From the viewpoint of sufficiently capturing volatile organic compounds such as 2-ethylhexanoic acid, the amount of alkaline earth metal salts, etc., is preferably 0.003 parts by mass or more, more preferably 0.015 parts by mass or more, and even more preferably 0.05 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 manufacturing costs, it is preferably 1.0 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.25 parts by mass or less. From these viewpoints, the amount of alkaline earth metal salts, etc., blended is preferably 0.003 parts by mass or more and 1.0 part by mass or less, more preferably 0.015 parts by mass or more and 0.5 parts by mass or less, and even more preferably 0.05 parts by mass or more and 0.25 parts by mass or less, per 100 parts by mass of polyol. Furthermore, the capture mechanism described later is influenced by the ratio of alkaline earth metal salts, etc., to the metal catalyst tin octoate (tin compound). In other words, the degree to which VOC generation is suppressed is influenced by this ratio. Therefore, from this viewpoint, the amount of alkaline earth metal salts, etc., is preferably 0.1 moles or more, more preferably 0.2 moles or more, and even more preferably 0.5 moles or more per mole of tin octoate (tin compound). On the other hand, from the viewpoint of maintaining the various physical properties of polyurethane foam and from the viewpoint of manufacturing costs, it is preferably 10.0 moles or less, more preferably 5.0 moles or less, and even more preferably 3.0 moles or less. From these viewpoints, the amount of alkaline earth metal salts, etc., blended is preferably 0.1 moles or more and 10.0 moles or less, more preferably 0.2 moles or more and 5.0 moles or less, and even more preferably 0.5 moles or more and 3.0 moles or less per mole of tin octoate (tin compound).

[0043] When the alkaline earth metal salt is an alkaline earth metal salt of a hydroxycarboxylic acid, the amount of the alkaline earth metal salt, etc., blended in the polyurethane resin composition is not particularly limited and should be blended as long as it is present. From the viewpoint of sufficiently capturing volatile organic compounds such as 2-ethylhexanoic acid, the amount of the alkaline earth metal salt, etc., blended 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 maintaining the various physical properties of the polyurethane foam and from the viewpoint of manufacturing costs, it is preferably 1.0 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.25 parts by mass or less. From these viewpoints, the amount of the alkaline earth metal salt, etc., blended is preferably 0.01 parts by mass or more and 1.0 part by mass or less, more preferably 0.05 parts by mass or more and 0.5 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.25 parts by mass or less, per 100 parts by mass of polyol.

[0044] (7.7) Other additives Polyurethane resin compositions may contain other additives as appropriate, such as crosslinking agents, plasticizers, flame retardants, fillers, antioxidants, UV absorbers, defoaming agents, compatibilizers, colorants, stabilizers, antibacterial agents, antifungal agents, deodorizers, fragrances, and scents. 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 colorants include pigments, dyes, and colorants.

[0045] (8) Capturing mechanism of volatile organic compounds in polyurethane foam The mechanism for capturing volatile organic compounds will be explained. An example will be given where liquid tin octoate is present. In this case, 2-ethylhexanoic acid is generated from tin octoate. In conventional formulations, 2-ethylhexanoic acid volatilizes from the polyurethane foam to become a VOC. In the case of the polyurethane foam of this embodiment, one or more compounds selected from the group consisting of alkali metal salts and alkali metal hydroxides are involved in the capture of "alkali metal ions (K)". +(Potassium ion), Na + (Sodium ion), Li + (Lithium ion))」「Alkaline earth metal (Ca 2+ (Calcium ion), Mg 2+ (Magnesium ion)」 combines (ionic bond) with 2-ethylhexanoic acid to form potassium octylate, sodium octylate, lithium octylate, calcium octylate, magnesium octylate (hereinafter also referred to as "potassium octylate, etc."). It is presumed that this potassium octylate, etc. is solid at room temperature and does not volatilize, and the generation of VOC is suppressed.

[0046] (9) Physical properties of polyurethane foam The physical properties of the polyurethane foam can be appropriately set according to the intended use, etc. The polyurethane foam is preferably a flexible polyurethane foam. The polyurethane foam preferably has the following physical properties. (9.1) Apparent density The apparent density (JIS K7222) is preferably 8 kg / m 3 -150 kg / m 3 is more preferably 10 kg / m 3 -100 kg / m 3 is even more preferable. (9.2) Hardness The hardness (JIS K6400-2 D method) is preferably 10 N - 600 N, and more preferably 20 N - 400 N. If it is 600 N or less, it is rich in flexibility and preferable as a flexible polyurethane foam. (9.3) Rebound resilience The rebound resilience (JIS K6400-3) is preferably 1% - 80%, and more preferably 5% - 70%. (9.4) Tensile strength, elongation The tensile strength (JIS K6400-5) is preferably 30 kPa or more, and more preferably 50 kPa or more. The elongation (JIS K6400-5) is preferably 50% - 500%. If it is 50% or more, it is rich in flexibility and preferable as a flexible polyurethane foam. (9.5) Flammability (FMVSS 302) The polyurethane foam preferably has flame retardancy that meets the U.S. automotive safety standards (FMVSS-302).

[0047] 2. Polyurethane foam (Part 2) The polyurethane foam is obtained from a composition of a polyol, a catalyst, and an isocyanate, wherein the composition contains one or more compounds selected from the group consisting of alkali metal salts of hydroxycarboxylic acids and alkaline earth metal salts of hydroxycarboxylic acids. Polyurethane foam (part 2) differs from polyurethane foam (part 1) in that the flame retardant is an optional component and contains one or more compounds selected from the group consisting of alkali metal salts of hydroxycarboxylic acids and alkaline earth metal salts of hydroxycarboxylic acids. In polyurethane foam (part 2), the explanations for "polyol," "catalyst," "isocyanate," "alkali metal salts of hydroxycarboxylic acids," and "alkaline earth metal salts of hydroxycarboxylic acids" are the same as those in the section for "polyurethane foam (part 1)," and are omitted here.

[0048] 3. Polyurethane foam (Part 3) Polyurethane foam is a flame-retardant polyurethane foam in which one or more elements selected from the group consisting of alkali metals and alkaline earth metals are detected by qualitative analysis. Polyurethane foam is usually obtained from a composition ("polyurethane resin composition") which is a mixture of polyol, catalyst, foam stabilizer, blowing agent, and isocyanate. Alkali metals can be detected by ICP emission spectroscopy. Potassium can also be detected by XRF qualitative analysis. Alkaline earth metals can be detected by ICP emission spectroscopy. If qualitative analysis of polyurethane foam detects one or more substances selected from the group consisting of alkali metals and alkaline earth metals, it means that one or more substances selected from the group consisting of alkali metals and alkaline earth metals remain in the polyurethane foam. In this case, it is possible that one or more substances selected from the group consisting of alkali metal salts, alkali metal hydroxides, alkaline earth metal salts, and alkaline earth metal hydroxides remain, resulting in a good VOC value. Furthermore, while the detection of alkali metals by qualitative analysis is a requirement for polyurethane foam (part 3), if the alkali metal content is 15 ppm or more, the VOC value is likely to be less than 200 ppm; if the alkali metal content is 40 ppm or more, the VOC value is likely to be less than 100 ppm; and if the alkali metal content is 85 ppm or more, the VOC value is likely to be 40 ppm or less. Generally, if the upper limit for alkali metal content is 500 ppm or less, the VOC value will be low and there will be no problem. Furthermore, for polyurethane foam (part 3), it is required that alkaline earth metals be detected by qualitative analysis. If the alkaline earth metal content is 20 ppm or more, the VOC value is likely to be less than 200 ppm. If the alkali metal content is 40 ppm or more, the VOC value is likely to be less than 100 ppm. If the alkali metal content is 70 ppm or more, the VOC value is likely to be 40 ppm or less. Generally, if the upper limit for alkali metal content is 500 ppm or less, the VOC value will be low and there will be no problem. In Polyurethane Foam (Part 3), the explanations for "polyol," "catalyst," and "isocyanate" in the "Polyurethane Foam (Part 1)" section will be applied as is, and their descriptions will be omitted. In other words, the explanations for "polyol," "catalyst," and "isocyanate" in the "Polyurethane Foam (Part 1)" section will be applied as is.

[0049] 4. Manufacturing of polyurethane foam Polyurethane foam can be produced by known foaming methods, which involve stirring and mixing a polyurethane resin composition to react a polyol with an isocyanate. Foaming methods include slab foaming and mold foaming, and either method may be used. Slab foaming involves extruding the mixed polyurethane resin composition onto a belt conveyor and foaming it at atmospheric pressure and room temperature. Mold foaming, on the other hand, involves filling a mold with the mixed polyurethane resin composition and foaming it within the mold. [Examples]

[0050] 1. Manufacturing of polyurethane foam Polyurethane resin compositions were prepared using the proportions shown in Tables 1 and 2, and polyurethane foams for the examples and comparative examples were produced by slab foaming. Details of each ingredient are as follows: • Polyol 1: Polyether polyol, 3 functional groups, molecular weight 3000, hydroxyl value 56 mgKOH / g, product name: GP-3050, manufactured by Sanyo Chemical Industries, Ltd. • Polyol 2: Polyether ester polyol, 3 functional groups, molecular weight 3000, hydroxyl value 58 mgKOH / g, product name: L-50, manufactured by Sanyo Chemical Industries, Ltd. • Flame retardant 1: Aliphatic condensed phosphate ester, product name: Fyrol PNX-LE, manufactured by ICL Industrial Products. • Flame retardant 2: A mixture of flame retardant filler, 62% by mass of polyvinyl chloride, 26% by mass of antimony trioxide, and 12% by mass of zinc oxide. • Organic compound (MBT): 2-mercaptobenzothiazole • Amine catalyst: N,N-dimethylaminohexanol • Foaming agent: Water • Foam stabilizer: Silicone-based foam stabilizer, product name: TEGOSTAB B8239, manufactured by EVONIK. • Metal catalyst: Tin(II) octoate • Isocyanate: Toluene diisocyanate (TDI), Product name: Coronate T-80, Manufactured by Tosoh Corporation

[0051] The polyurethane foam was manufactured using the following procedure: The raw materials other than the isocyanate were measured into a cup container, stirred, and mixed to form a mixed solution. The metal salts, such as potassium carbonate, and the metal base were dissolved in water as a foaming agent and then mixed with the polyol. Isocyanate was added to the mixed solution and stirred to obtain a polyurethane resin composition.

[0052] [Table 1]

[0053] [Table 2]

[0054] 2. Evaluation Method (1) Apparent density (density) The apparent density was measured according to JIS K7222. (2) Hardness Hardness was measured using the JIS K6400-2 Method D. (3) Rebound elasticity The rebound elasticity was measured according to JIS K6400-3. (4) Tensile strength, elongation Tensile strength and elongation were measured according to JIS K6400-5. (5) Flammability (FMVSS 302) Flame retardancy was measured in accordance with the U.S. Automotive Safety Standard (FMVSS-302). (6) VOC values VOC values ​​were measured by preparing 7 mg test specimens from each sample, placing them in glass tubes, and using a thermal desorption apparatus to perform the VOC measurement method specified in "German Association of the Automotive Industry VDA278". Specifically, each test specimen was heated at 90°C for 30 minutes, and the gas generated during heating was analyzed using a gas chromatograph-mass spectrometer to calculate the VOC value. (7) Alkali metal or alkaline earth metal content Approximately 0.2 g of urethane foam was taken out, 10 mL of nitric acid (1+1) was added, and it was completely decomposed by microwave heating decomposition to a final volume of 25 mL. The alkali metal or alkaline earth metal content of the above-mentioned decomposition solution was quantified by qualitative and quantitative analysis at the following measurement wavelengths using a SPECTRO ARCOS multi-type ICP emission spectrometer manufactured by SPECTRO. Na: 589.592nm K: 766.491nm Ca: 396.847nm

[0055] 3.Results The results are shown in Tables 1 and 2. The overall evaluation was as follows: (Evaluation Criteria) A: The physical properties of the polyurethane foam are equivalent to those of conventional products, and the VOC content is less than 40 ppm. B: The physical properties of the polyurethane foam are equivalent to those of conventional products, and the VOC content is between 40 ppm and 100 ppm. C: The physical properties of the polyurethane foam are equivalent to those of conventional products, and the VOC content is between 100 ppm and less than 200 ppm. D: The physical properties of the polyurethane foam are equivalent to those of conventional products, and the VOC content is 200 ppm or higher. For Examples 1 and 2, Comparative Example 1 was considered equivalent to the conventional product. For Examples 3-6, Comparative Example 2 was considered equivalent to the conventional product. For Examples 7-13, Comparative Example 3 was considered equivalent to the conventional product. Here, among the physical properties, hardness, rebound elasticity, and tensile strength were judged to be equivalent if they were within ±25% of each conventional product.

[0056] The polyurethane foams of Examples 1-13 received favorable overall evaluation results. A significant reduction in VOCs was confirmed by adding one or more compounds selected from the group consisting of alkali metal salts, alkali metal hydroxides, alkaline earth metal salts, and alkaline earth metal hydroxides. In addition, alkali metals or alkaline earth metals were detected in qualitative analysis in all of Examples 1-13.

[0057] <Effects of the Example> According to the above examples, it is possible to provide a polyurethane foam that has good physical properties and reduced VOC content.

[0058] This disclosure is not limited to the embodiments detailed above, and various modifications or changes are possible within the scope of this disclosure.

Claims

1. Polyols and, Catalyst and Flame retardant and Isocyanates and, A polyurethane foam obtained from a mixed composition, The composition contains one or more compounds selected from the group consisting of alkali metal salts of carbonate, alkali metal salts of acetate, alkali metal salts of hydroxycarboxylic acids, alkali metal hydroxides, alkaline earth metal salts of carbonate, alkaline earth metal salts of acetate, alkaline earth metal salts of hydroxycarboxylic acids, and alkaline earth metal hydroxides. A polyurethane foam that satisfies (1) and / or (2) below. (1) The apparent density (JIS K7222) is 8 kg / m³ to 150 kg / m³, and the hardness (JIS K6400-2 D method) is 10 N to 600 N. (2) The apparent density (JIS K7222) is 8 kg / m³ to 150 kg / m³, and the elongation (JIS K6400-5) is 50% to 500%.

2. The polyurethane foam according to claim 1, wherein the composition contains 0.003 parts by mass or more and 3 parts by mass or less of the compound with respect to 100 parts by mass of the polyol.

3. The polyurethane foam according to claim 1 or claim 2, wherein the catalyst comprises a metal catalyst.

4. The polyurethane foam according to claim 1 or claim 2, wherein the total VOC value of the polyurethane foam, as measured by the VOC measurement method specified in German Association of the Automotive Industry VDA 278, which is an indicator of the suppression of volatile organic compound emissions, is less than 200 ppm.

5. The polyurethane foam according to claim 1 or claim 2, having flame retardancy that meets the U.S. automotive safety standards (FMVSS-302).

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