Polyurethane foam

Abstract

The purpose of the present invention is to provide a low-density polyurethane foam that can be easily produced. The polyurethane foam is obtained from a composition containing a polyol compound and a polyisocyanate compound. The polyol contains a polyol derived from a plant. The hydroxyl value of the plant-derived polyol is 130 mgKOH / g or less. The density of the polyurethane foam according to JIS K7222 is 25 kg / m3 or less.

Description

Technical Field

[0001] The present disclosure relates to a polyurethane foam. Background Art

[0002] Patent Document 1 discloses a polyurethane foam obtained from a composition containing a plant-derived polyol. In addition, there is a demand for polyurethane foams for low-density applications.

[0003] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2011-202026 Summary of the invention Problem that the invention aims to solve In the polyurethane foam of Patent Document 1, a polyol derived from castor oil having a hydroxyl value of about 160 mgKOH / g is used as a raw material. By using a polyol having a high hydroxyl value, the internal exothermic temperature during foaming tends to increase, making it difficult to manufacture. Therefore, a low-density polyurethane foam that is easy to manufacture is required.

[0004] The present disclosure has been made in view of the above-mentioned actual situation, and an object of the present disclosure is to provide a low-density polyurethane foam that can be easily produced.

[0005] The present disclosure can be implemented in the following ways.

[0006] Means used to solve problems [1] A polyurethane foam obtained from a composition containing polyols and polyisocyanates, wherein: The polyols contain polyols of plant origin, The hydroxyl value of the plant-derived polyol is less than 130 mgKOH / g, The density of the polyurethane foam according to JIS K7222 is 25 kg / m 3 the following.

[0007] Effects of the Invention The present disclosure provides a low-density polyurethane foam that can be easily manufactured. DETAILED DESCRIPTION

[0008] Here, preferred examples of the present disclosure are shown.

[0009] [2] The polyurethane foam according to [1], wherein the isocyanate index is 91 or more.

[0010] [3] The polyurethane foam according to [1] or [2], wherein the polyol contains a petroleum-derived polyol, and when the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass, the plant-derived polyol is 75 parts by mass or less.

[0011] [4] The polyurethane foam according to any one of [1] to [3], wherein the compressive residual strain according to JIS K6400-4 4.5.2 is less than 8.5%.

[0012] [5] The polyurethane foam according to any one of [1] to [4], wherein the rebound elasticity according to JIS K6400-3 is 25% to 45%.

[0013] [6] The polyurethane foam according to any one of [1] to [5], which is used for bedding.

[0014] The present disclosure is described in detail below. In addition, in this specification, regarding the numerical range, in the description using "-", unless otherwise specified, the lower limit and the upper limit are included. For example, in the description such as "10-20", both "10" as the lower limit and "20" as the upper limit are included. That is, "10-20" has the same meaning as "10 or more and 20 or less".

[0015] 1. Polyurethane foam The polyurethane foam is obtained from a polyurethane resin composition (hereinafter also referred to as a composition) containing polyols and polyisocyanates. The polyols contain plant-derived polyols. Preferably, the polyols contain petroleum-derived polyols.

[0016] [Plant-derived polyols] Plant-derived polyols include castor oil, for example. The "castor oil" in the present disclosure does not include the modified castor oil and dehydrated castor oil described later. The "castor oil" in the present disclosure refers to unmodified castor oil. Unmodified castor oil is extracted and refined from castor seeds of the Euphorbiaceae family, and is not subjected to the crosslinking (modification) treatment or dehydration treatment based on dibasic acids, etc., which is described later. Dehydrated castor oil is castor oil (non-drying oil) that is dehydrated and made into a drying oil. Castor oil is an ester of fatty acids and glycerol. Castor oil has ricinoleic acid as a main component, and as other components, it contains unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid, and saturated fatty acids such as palmitic acid and stearic acid.

[0017] The plant-derived polyol may contain modified plant-derived fats and oils as a component using plant-derived fats and oils. Examples of the modified plant-derived fats and oils include modified castor oil.

[0018] Modified plant-derived oils such as modified castor oil are obtained by mixing dibasic acid and plant-derived oils in a manner that becomes a target property and performing a dehydration condensation reaction. The synthesis of the modified plant-derived oils can use a known method. For example, after dissolving the plant-derived oil in an arbitrary solvent, a dibasic acid is added. The reaction solution is refluxed through a Dean-Stark apparatus, and while performing a dehydration condensation reaction, the water generated by the reaction is removed outside the reaction system. After the reaction is completed, the solvent is removed by decompression to obtain the target compound.

[0019] Examples of the dibasic acid include aliphatic dibasic acids, alicyclic dibasic acids, aromatic dibasic acids, and mixtures thereof. Examples of the aliphatic dibasic acid include sebacic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid, docosanedioic acid, tetracosanedioic acid, hexacosanedioic acid, octacosanedioic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, mesaconic acid, muconic acid, and mixtures thereof.

[0020] Examples of the alicyclic dibasic acid include cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, decahydronaphthalene dicarboxylic acid, tetrahydrophthalic acid, nadic acid (himic acid), and mixtures thereof.

[0021] Examples of the aromatic dibasic acid include terephthalic acid, isophthalic acid, phthalic acid, bibenzoic acid, toluene dicarboxylic acid, xylene dicarboxylic acid, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ketone dicarboxylic acid, phenylindane dicarboxylic acid, and mixtures thereof.

[0022] As the dibasic acid, a hydroxy dibasic acid containing a hydroxyl group in the molecule can be used. Examples of the hydroxy dibasic acid include tartronic acid, isomalic acid, hydroxymethylmalonic acid, dihydroxymalonic acid, malic acid, hydroxymethylsuccinic acid (itamaric acid), citramalic acid, methylmalic acid, ethylmalic acid, dimethylmalic acid, trimethylmalic acid, tartaric acid, 2,2-dihydroxysuccinic acid, methyltartaric acid, dimethyltartaric acid, hydroxyglutaric acid, dihydroxyglutaric acid, trihydroxyglutaric acid, hydroxyadipic acid, dihydroxyadipic acid, hydroxypimelic acid, dihydroxypimelic acid, hydroxyoctanedioic acid, hydroxyazelaic acid, dihydroxyazelaic acid, hydroxysebacic acid, dihydroxysebacic acid, hydroxydodecanedioic acid, dihydroxydodecanedioic acid, hydroxytridecanedioic acid, hydroxytetradecanedioic acid, dihydroxyhexadecanedioic acid, hydroxyoctadecanediic acid, dihydroxyoctadecanediic acid, 9,10-dihydroxyoctadecanediic acid, hydroxyeicosanedioic acid, dihydroxyeicosanedioic acid, and dihydroxyfumaric acid (dihydroxy dihydroxyphthalic acid, hydroxynaphthalic acid, dihydroxynaphthalic acid, hydroxydiphenylsulfone dicarboxylic acid, meconic acid, or a mixture thereof.

[0023] The dibasic acid preferably contains sebacic acid. Sebacic acid is a dibasic acid of plant origin.

[0024] When the sum of the polyol of petroleum origin and the polyol of plant origin is set to 100 mass parts, from the viewpoint of coping with the environment, the polyol of plant origin is preferably greater than 0 mass parts, more preferably more than 30 mass parts, and more preferably more than 40 mass parts. When the sum of the polyol of petroleum origin and the polyol of plant origin is set to 100 mass parts, from the viewpoint of ensuring strength, the polyol of plant origin is preferably less than 75 mass parts, more preferably less than 65 mass parts, and more preferably less than 55 mass parts. From these viewpoints, when the sum of the polyol of petroleum origin and the polyol of plant origin is set to 100 mass parts, the polyol of plant origin is preferably greater than 0 mass parts and less than 75 mass parts, more preferably more than 30 mass parts and less than 65 mass parts, and more preferably more than 40 mass parts and less than 55 mass parts.

[0025] From the viewpoint of promoting the reaction, the hydroxyl value of the polyol of plant origin is preferably 40 mgKOH / g or more, more preferably 60 mgKOH / g or more, and further preferably 80 mgKOH / g or more. From the viewpoint of suppressing the heat release during foaming, the hydroxyl value of the polyol of plant origin is 130 mgKOH / g or less, preferably 115 mgKOH / g or less, and more preferably 100 mgKOH / g or less. From these viewpoints, the hydroxyl value of the polyol of plant origin is 40 mgKOH / g or more and 130 mgKOH / g or less, preferably 60 mgKOH / g or more and 115 mgKOH / g or less, and more preferably 80 mgKOH / g or more and 100 mgKOH / g or less. In addition, the hydroxyl value in a mixture of two or more polyols of plant origin is the value of the mixture as a whole.

[0026] [Petroleum-derived polyols] The polyol of petroleum origin is not particularly limited. When the sum of the polyol of petroleum origin and the polyol of plant origin is set to 100 mass parts, from the viewpoint of ensuring strength, the polyol of petroleum origin is preferably greater than 0 mass parts, more preferably more than 20 mass parts, and more preferably more than 40 mass parts. When the sum of the polyol of petroleum origin and the polyol of plant origin is set to 100 mass parts, from the viewpoint of coping with the environment, the polyol of petroleum origin is preferably less than 80 mass parts, more preferably less than 70 mass parts, and more preferably less than 60 mass parts. From these viewpoints, when the sum of the polyol of petroleum origin and the polyol of plant origin is set to 100 mass parts, the polyol of petroleum origin is preferably greater than 0 mass parts and less than 80 mass parts, more preferably more than 20 mass parts and less than 70 mass parts, and more preferably more than 40 mass parts and less than 60 mass parts.

[0027] Examples of petroleum-derived polyols include polyether polyols, polymer polyols, and polyester polyols.

[0028] Examples of the polyether polyol include polyether polyols obtained by adding alkylene oxides such as ethylene oxide (EO) and propylene oxide (PO) to polyvalent alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, and sucrose.

[0029] The polyether polyol preferably has a weight average molecular weight of 500-8000 (preferably 800-5000, more preferably 1000-3000) and a functional group number of 2-6 (preferably 2 or 3).

[0030] As the polymer polyol, for example, a polymer polyol formed by graft copolymerizing a vinyl monomer such as acrylonitrile and styrene on a polyether polyol having a functional group number of 2 or 3 as a base polyol can be suitably used. As the above-mentioned base polyol, for example, a polyether polyol containing PO units (propylene oxide units) and EO units (ethylene oxide units) as AO units (alkylene oxide units) can be cited. In addition, the weight average molecular weight of the polymer polyol refers to the weight average molecular weight of the base polyol.

[0031] As the polyester polyol, for example, polycaprolactone polyester polyol, adipic acid polyester polyol, etc. can be used. As the polycaprolactone polyester polyol, for example, polyester polyols obtained by ring-opening addition polymerization of lactones such as ε-caprolactone can be cited. As the adipic acid polyester polyol, for example, polyester polyols obtained by polycondensation of polyfunctional carboxylic acids and polyfunctional hydroxy compounds can be cited. Polyester polyols also have the effect of miniaturizing and homogenizing the cells of polyurethane foam.

[0032] [Other polyols] In addition, as the polyols, other polyols other than the above-mentioned polyols may be contained. As the other polyols, there are no particular limitations as long as they are polyols generally used in polyurethane foams, and any of them can be used.

[0033] In the present disclosure, when low molecular weight polyvalent alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, glycerol, trimethylolpropane, pentaerythritol, and sorbitol are used, these polyvalent alcohols are also included in the polyols.

[0034] [Polyisocyanates] Polyisocyanates are compounds having multiple isocyanate groups, and for example, aromatic isocyanates such as toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate, and xylylene diisocyanate (XDI), alicyclic isocyanates such as isophorone diisocyanate (IPDI) and dicyclohexylmethane diisocyanate, aliphatic isocyanates such as hexamethylene diisocyanate (HDI), or free isocyanate prepolymers obtained by reacting these compounds with polyols, and modified isocyanates such as carbodiimide-modified isocyanates can be used. In addition, these polyisocyanates may contain only one type, or may contain two or more types in combination.

[0035] The polyisocyanate may be any of aromatic, alicyclic, and aliphatic isocyanates. In addition, it 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. These may be used alone or in combination. For example, bifunctional isocyanates include 2,4-toluene diisocyanate (TDI), 2,6-toluene diisocyanate (TDI), m-p-phenylene diisocyanate, p-p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4'-diphenylmethane diisocyanate (MDI), 2,2'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate, 3,3'-dimethyl-4,4'- Aromatic isocyanates such as biphenyl diisocyanate and 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, alicyclic isocyanates such as cyclohexyl-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexane diisocyanate, and aliphatic isocyanates such as 1,4-butyl diisocyanate, hexamethylene diisocyanate, isopropyl diisocyanate, methylene diisocyanate, and lysine isocyanate. In addition, examples of isocyanates having two or more functions include polymethylene polyphenyl polyisocyanate (polymeric MDI). As trifunctional or higher isocyanates, 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, etc. can be cited. In addition, the isocyanate is not limited to one kind each, and can also be two or more kinds. For example, one kind of aliphatic isocyanate and two kinds of aromatic isocyanates can be used together.

[0036] The isocyanate index is the equivalent ratio of the isocyanate group of the polyisocyanate relative to the reactive groups such as hydroxyl groups that can react with isocyanate in the polyols. Therefore, when the value is less than 100, it means that the reactive groups such as hydroxyl groups are in excess of the isocyanate groups, and when it exceeds 100, it means that the isocyanate groups are in excess of the reactive groups such as hydroxyl groups. From the viewpoint of reaction stability, the isocyanate index (INDEX) of the polyisocyanate is preferably 91 or more, more preferably 93 or more, and further preferably 95 or more. From the viewpoint of suppressing heat generation during foaming, the isocyanate index (INDEX) of the polyisocyanate is preferably 125 or less, more preferably 115 or less, and further preferably 110 or less. From these viewpoints, the isocyanate index (INDEX) of the polyisocyanate is preferably 91 or more and 125 or less, more preferably 93 or more and 115 or less, and further preferably 95 or more and 110 or less.

[0037] [catalyst] The composition preferably contains a catalyst. The catalyst is mainly used to promote the polyurethane reaction of polyols and polyisocyanates. As the catalyst, a known catalyst commonly used for polyurethane foam can be used, for example, tertiary amines such as triethylenediamine, N,N-dimethylethanolamine, 6-dimethylamino-1-hexanol, N,N',N'-trimethylaminoethylpiperazine, organic metal compounds such as stannous octoate and tin octoate, acetate, and alkali metal alkoxide.

[0038] When the total amount of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass, the content of the catalyst in the composition is preferably 0.1 parts by mass or more and 5.0 parts by mass or less. If the content is 0.1 parts by mass or more, the polyurethane reaction can be sufficiently promoted. If it is 5.0 parts by mass or less, the uneven formation of the cell structure caused by excessive promotion of the polyurethane reaction can be suppressed.

[0039] [Foam stabilizer] The composition preferably contains a foam stabilizer. The foam stabilizer is not particularly limited. The foam stabilizer is preferably silicone compounds such as organopolysiloxane, organopolysiloxane-polyoxyalkylene copolymer, polyalkenyl siloxane with polyoxyalkylene side chain, silicone-lubricating oil copolymer, anionic surfactants such as sodium dodecylbenzene sulfonate and sodium lauryl sulfate, polyether siloxane, phenolic compounds, etc. These foam stabilizers can be used alone or in combination of two or more. The amount of the foam stabilizer is not particularly limited. When the sum of the petroleum-derived polyol and the plant-derived polyol is set to 100 parts by mass, the amount of the foam stabilizer is preferably 0.03 parts by mass or more and 5.0 parts by mass or less.

[0040] [Foaming agent] The composition preferably contains a foaming agent. The foaming agent is not particularly limited. As the foaming agent, for example, water, carbon dioxide, hydrohaloolefins, etc. are suitable for use. When the foaming agent is water, the amount added depends on the target density in the polyurethane foam or the range in which a good foaming state can be obtained. Usually, when the sum of the petroleum-derived polyol and the plant-derived polyol is set to 100 parts by mass, it is preferably 1 part by mass or more and 10 parts by mass or less.

[0041] Examples of the hydrohaloolefin include hydrofluoroolefins (HFO), hydrochlorofluoroolefins (HCFO), etc. The content of the hydrohaloolefin is preferably greater than 0 parts by mass and less than 25 parts by mass, based on 100 parts by mass of the total of the petroleum-derived polyol and the plant-derived polyol.

[0042] [Other ingredients] The composition may contain other ingredients other than the above as required. As other ingredients, for example, antioxidants, ultraviolet absorbers, thickeners, plasticizers, antibacterial agents and colorants may be mentioned. In addition, as antioxidants, for example, butylated hydroxytoluene and hindered phenol antioxidants may be mentioned, but from the viewpoint of reducing the content of volatile organic compounds, hindered phenol antioxidants with a molecular weight of more than 300 are particularly preferred. As thickeners, for example, calcium carbonate, aluminum hydroxide and magnesium hydroxide may be mentioned.

[0043] 2. Density requirements In the polyurethane foam, the density according to JIS K7222 is preferably 30 kg / m 3 Below, more preferably 27kg / m 3 Below, more preferably 25kg / m 3 Below, particularly preferably 24kg / m 3 The following is the density of polyurethane foam according to JIS K7222, which is usually 5kg / m 3 above.

[0044] 3. Requirements for compressive residual strain In the polyurethane foam, the compressive residual strain according to JIS K6400-44.5.2A method is preferably less than 10%, more preferably less than 8.5%, and further preferably less than 5%. In the polyurethane foam, the compressive residual strain according to JIS K6400-44.5.2A method is usually 0.5% or more.

[0045] 4. Requirements for the rebound modulus In polyurethane foam, the rebound elastic modulus based on the rebound test according to JIS K6400-3 is preferably 10% or more, more preferably 25% or more, and further preferably 30% or more. In polyurethane foam, the rebound elastic modulus based on the rebound test according to JIS K6400-3 is preferably 80% or less, more preferably 60% or less, and further preferably 45% or less. From these viewpoints, in polyurethane foam, the rebound elastic modulus based on the rebound test according to JIS K6400-3 is preferably 10% or more and 80% or less, more preferably 25% or more and 60% or less, and further preferably 30% or more and 45% or less.

[0046] 5. Requirements for elongation In the polyurethane foam, the elongation according to JIS K6400-55 is preferably 80% or more, more preferably 90% or more, and further preferably 100% or more. In the polyurethane foam, the elongation according to JIS K6400-55 is usually 500% or less.

[0047] 6. Requirements for hardness In the polyurethane foam, the hardness according to the JIS K6400-26.7D method is preferably 20N or more, more preferably 40N or more, and further preferably 60N or more. In the polyurethane foam, the hardness according to the JIS K6400-26.7D method is preferably 300N or less, more preferably 200N or less, and further preferably 150N or less. From these viewpoints, in the polyurethane foam, the hardness according to the JIS K6400-26.7D method is preferably 20N or more and 300N or less, more preferably 40N or more and 200N or less, and further preferably 60N or more and 150N or less.

[0048] 7. Requirements for ventilation volume In the polyurethane foam, the air flow rate according to JIS K6400-7 is preferably 30 L / min or more, more preferably 40 L / min or more, and further preferably 50 L / min or more. In the polyurethane foam, the air flow rate according to JIS K6400-7 is usually 300 L / min or less.

[0049] 8. Requirements for biomass content based on the blending ratio of raw materials The biomass content (hereinafter also referred to as the biomass content of the raw materials) based on the blending ratio of the raw materials in the polyurethane foam is calculated using the following formula (1). In formula (1), "the number of added portions of plant-derived polyols" refers to the total number of added portions of all plant-derived polyols when multiple plant-derived polyols are used. The "number of added portions of plant-derived polyols" also includes the number of added portions of any one of unmodified castor oil, modified castor oil, and dehydrated castor oil. In addition, in the "number of added portions of plant-derived polyols", when the plant-derived polyol has a plant-derived degree of less than 100%, the number of added portions of the plant-derived polyol is multiplied by the plant-derived degree. Here, the plant-derived degree refers to the proportion of plant-derived materials in the raw materials. In formula (1), "the total number of added portions of the polyurethane resin composition" refers to the total number of added portions of all raw materials contained in the polyurethane resin composition. All raw materials refer to plant-derived polyols, petroleum-derived polyols, catalysts, foam stabilizers, blowing agents, polyisocyanates, and other raw materials (cross-linking agents, antimicrobial agents, pigments, flame retardants, etc.). When water is used as a blowing agent, the gas loss in formula (1) is calculated using the following formula (2). In formula (2), "18" is the molecular weight of water and "44" is the molecular weight of carbon dioxide. In addition, when the polyurethane resin composition contains HFO as a blowing agent, it is assumed that all HFO volatilizes during the reaction, and the biomass content in the polyurethane foam is calculated using the following formula (3). The units of "the number of added portions of plant-derived polyols", "the total number of added portions of the polyurethane resin composition", and "the number of added portions of HFO" are parts by mass.

[0050] [Formula 1]

[0051] [Formula 2]

[0052] [Formula 3]

[0053] In the polyurethane foam, the biomass content of the raw material is preferably 20% or more, more preferably 25% or more, and further preferably 30% or more.

[0054] 9. Requirements for biomass content based on the AMS method The biomass content of polyurethane foam is obtained by measuring the value by accelerator mass spectrometry (AMS method) based on ASTM D6866-21. The carbon 14 concentration of polyurethane foam and the standard substance of the carbon 14 concentration in the atmosphere in 1950 are measured and compared to the biomass content. However, since the carbon 14 concentration in the atmosphere is increasing every year, the carbon 14 concentration value is multiplied by a coefficient for correction. The biomass content is calculated according to ASTM D6866-21, and the atmospheric correction factor REF (pMC) = 100.0 is used to calculate the biomass content.

[0055] The biomass content of the polyurethane foam measured by the AMS method based on ASTM D6866-21 (hereinafter also referred to as the biomass content based on the AMS method) is preferably 20% or more, more preferably 25% or more, and further preferably 30% or more.

[0056] In addition, various numerical ranges described in the specification can each arbitrarily combine their upper limit values ​​and lower limit values, and all of these combinations are described in the present specification as preferred numerical ranges.

[0057] 10. Method for producing polyurethane foam Polyurethane foam can be produced by a known foaming method in which a polyol and a polyisocyanate are reacted by stirring and mixing a polyurethane resin composition. The foaming method includes slab foaming and mold foaming, and any molding method can be used. Slab foaming is a method in which a mixed polyurethane resin composition is sprayed onto a conveyor belt and foamed at atmospheric pressure and room temperature. On the other hand, mold foaming is a method in which a mixed polyurethane resin composition is filled into a mold (molding mold) and foamed in the mold.

[0058] 11. Application of polyurethane foam Polyurethane foam is suitable for bedding. For example, polyurethane foam can be used for mattresses, quilts, mattresses, pillows, etc. In addition, for example, polyurethane foam can be used for cushioning materials, sound absorbing materials, kitchen sponges, hydroponic cultivation medium for plants, etc.

[0059] 12. Functions and Effects of This Implementation In this embodiment, a low-density polyurethane foam having good foamability can be provided.

[0060] According to the polyurethane foam of this embodiment, the internal heat generation temperature during foaming can be lowered, and the production is easy.

[0061] According to the polyurethane foam of this embodiment, the biomass content can be increased.

[0062] According to the polyurethane foam of the present embodiment, the compressive residual strain can be reduced.

[0063] According to the polyurethane foam of this embodiment, the elongation can be increased.

[0064] Example Next, the above-mentioned embodiment will be described in more detail with reference to Examples and Comparative Examples.

[0065] 1. Production of polyurethane foam Polyurethane resin compositions blended in the ratios shown in Tables 1 and 2 were prepared, and polyurethane foams of Examples and Comparative Examples were produced by block foaming.

[0066] [Table 1]

[0067] [Table 2]

[0068] In Tables 1 and 2, the numerical values ​​of the components without indicating units other than indices represent parts by mass.

[0069] Various information on petroleum-derived polyols 1 to 3 and plant-derived polyols 1 and 2 are shown in Table 3 below.

[0070] Plant-derived polyol 2 is a castor oil-derived polyol composed of plant-derived polyol 1: sebacic acid = 2 mol: 1 mol and having a plant-derived degree of 100%. Sebacic acid is a derivative of castor oil and has a plant-derived degree of 100%. Plant-derived polyol 2 is a synthetic product produced by adding 100 parts by weight of plant-derived polyol 1 and 10.9 parts by weight of sebacic acid to a glass reactor equipped with a stirrer, a temperature regulator, etc., and reacting them under stirring for a predetermined time and a predetermined temperature.

[0071] The "OHV" column in Table 3 represents the hydroxyl value. In Example 2, the OHV of the plant-derived polyol containing 20 parts by mass of plant-derived polyol 1 and 25 parts by mass of plant-derived polyol 2 is 121.1 mgKOH / g. "Mw" represents the weight average molecular weight. "Mn" represents the number average molecular weight.

[0072] [Table 3]

[0073] In Tables 1 and 2, specific contents of the catalyst, foam stabilizer, blowing agent and polyisocyanate are as follows.

[0074] Catalyst 1: Aliphatic tertiary amine (manufactured by Evonik Japan, DABCO33LSI) Catalyst 2: Stannous octoate (manufactured by Chengbei Chemical Industry Co., Ltd., MRH-110) Foam stabilizer: Organic silicone (manufactured by Dow Corning Toray, SZ-1136) Blowing agent: Hydrofluoroolefin (manufactured by Chemours-Mitsui Fluoroproducts, Opteon TM 1100Foam Expansion Agent) Polyisocyanate: Toluene diisocyanate (TDI) 2,4 / 2,6 isomers mixed in a ratio of 80 / 20 (manufactured by Tosoh Corporation, CORONATE T-80) 2. Evaluation Next, the following evaluations were performed on the obtained polyurethane foams of each Example and each Comparative Example.

[0075] [Biomass content based on the blending ratio of raw materials] The biomass content based on the blending ratio of the raw materials was calculated using the above-mentioned formulas (1) to (3). The calculation results are shown in the column of "Biomass content of raw materials" in Tables 1 and 2.

[0076] [Biomass content based on the AMS method] The biomass content based on the AMS method is obtained by accelerator mass spectrometry (AMS method) based on ASTM D6866-21. The biomass content was calculated using the atmospheric correction factor REF (pMC) = 100.0 for 2021. The calculation results are shown in the "Biomass content based on the AMS method" column in Tables 1 and 2.

[0077] [Foaming properties] The foamability of the polyurethane foam was evaluated according to the following criteria.

[0078] "B": Foaming is good.

[0079] "C": Poor foaming.

[0080] [Internal temperature] The internal temperature of the polyurethane foam during foaming was evaluated according to the following criteria.

[0081] "B": less than 160℃ "C": 160℃ or above [density] The density of the polyurethane foam was determined by a measurement method in accordance with JIS K7222. The measurement results are shown in the "Density" column of Tables 1 and 2.

[0082] The density of the polyurethane foam was evaluated according to the following criteria.

[0083] "B": 25kg / m 3 the following "C": greater than 25kg / m 3 [Elongation] The elongation of the polyurethane foam was determined by a measurement method in accordance with JIS K6400-55. The measurement results are shown in the "elongation" column of Tables 1 and 2.

[0084] The elongation of the polyurethane foam was evaluated according to the following criteria.

[0085] "A": 100% or more "B": 80% or more and less than 100% "C": less than 80% [Rebound elastic modulus] The rebound elastic modulus of the polyurethane foam was determined by a measurement method in accordance with JIS K6400-3. The measurement results are shown in the column of "Rebound elastic modulus" in Tables 1 and 2.

[0086] The rebound elastic modulus of the polyurethane foam was evaluated according to the following criteria.

[0087] "A": 30% or more "B": 25% or more and less than 30% "C": less than 25% [hardness] The hardness of the polyurethane foam was determined by a measurement method in accordance with JIS K6400-26.7D method. The measurement results are shown in the "Hardness" column of Tables 1 and 2.

[0088] The hardness of the polyurethane foam was evaluated according to the following criteria.

[0089] "B": 20N or more and 300N or less "C": less than 20N or greater than 300N [Ventilation] The air flow rate of the polyurethane foam was determined by a measurement method in accordance with JIS K6400-7. The measurement results are shown in the "Air flow rate" column of Tables 1 and 2.

[0090] The air flow rate of the polyurethane foam was evaluated according to the following criteria.

[0091] "A": 50L / min or more "B": 30L / min or more and less than 50L / min "C": less than 30L / min [Compressive residual strain] The compressive residual strain of the polyurethane foam was determined by a measurement method in accordance with JIS K6400-44.5.2 Method A. The measurement results are shown in the column "Compressive residual strain" in Tables 1 and 2.

[0092] The compressive residual strain of the polyurethane foam was evaluated according to the following criteria.

[0093] "A": less than 5% "B": 5% or more and less than 10% "C": more than 10% [Overall evaluation] "A": None of "Evaluation of foaming property", "Evaluation of internal temperature", "Evaluation of density", "Evaluation of elongation", "Evaluation of rebound elastic modulus", "Evaluation of hardness", "Evaluation of air flow", and "Evaluation of compression residual strain" is "C" “B”: “C” for any one of “Evaluation of foaming property”, “Evaluation of internal temperature”, “Evaluation of density”, “Evaluation of elongation”, “Evaluation of rebound elastic modulus”, “Evaluation of hardness”, “Evaluation of air flow”, and “Evaluation of compression residual strain” 3. Results The "Density Evaluation" of Examples 1-12 and Comparative Examples 1-3 is "B". In Examples 1-12 and Comparative Examples 1-3, the polyurethane resin composition includes a plant-derived polyol containing castor oil or modified castor oil, and the density is 25 kg / m 3 The following low value.

[0094] Examples 1-12 satisfy both the following requirements (a) and (b). Comparative Examples 1 and 2 do not satisfy the following requirement (b). Comparative Example 3 does not satisfy the following requirement (a).

[0095] ・Requirement (a): The hydroxyl value of the plant-derived polyol is 130 mgKOH / g or less.

[0096] Requirement (b): The amount of the plant-derived polyol is 75 parts by mass or less, based on 100 parts by mass of the total of the petroleum-derived polyol and the plant-derived polyol.

[0097] The “comprehensive evaluation” of Examples 1 to 12 was “A”. In Examples 1 to 12, by satisfying the above requirements (a) and (b), the internal temperature of the polyurethane foam during foaming was reduced while the physical properties (rebound elastic modulus, air flow, and compression residual strain) were improved.

[0098] 4. Effects of the Embodiments According to the above embodiments, a low-density polyurethane foam having good foamability can be produced.

[0099] The internal exothermic temperature during foaming can be lowered, and the production is easy.

[0100] It can increase the biomass content of polyurethane foam.

[0101] It can increase the rebound elastic modulus of polyurethane foam.

[0102] It can increase the ventilation capacity of polyurethane foam.

[0103] Can reduce the compressive residual strain of polyurethane foam.

[0104] The present disclosure is not limited to the embodiments described in detail above, and various modifications or changes can be made within the scope of the claims of the present disclosure.

Claims

1. A polyurethane foam obtained from a composition containing polyols and polyisocyanates, wherein: The polyols contain polyols of plant origin, The hydroxyl value of the plant-derived polyol is less than 130 mgKOH / g, The density of the polyurethane foam according to JIS K 7222 is 25 kg / m 3 the following.

2. The polyurethane foam according to claim 1, wherein The isocyanate index is 91 or more.

3. The polyurethane foam according to claim 1 or 2, wherein The polyols contain polyols derived from petroleum, When the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass, the plant-derived polyol is 75 parts by mass or less.

4. The polyurethane foam according to claim 1 or 2, wherein The compressive residual strain according to JIS K6400-4 4.5.2 is less than 8.5%.

5. The polyurethane foam according to claim 1 or 2, wherein The rebound elasticity according to JIS K6400-3 is 25% or more and 45% or less.

6. The polyurethane foam according to claim 1 or 2, wherein For bedding.

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