Polyurethane foam

Abstract

The purpose of the present invention is to provide a polyurethane foam which contains a plant-derived polyol in a starting material and has high resilience. The polyurethane foam is obtained from a composition containing a polyhydric alcohol and a polyisocyanate. The polyol contains a plant-derived polyol. The plant-derived polyol has a hydroxyl value of 130 mgKOH / g or less. And the isocyanate index is 91 or more. The elastic modulus of resilience according to JISK6400-3 is 25% or more.

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 a polyurethane foam having a high rebound elastic modulus.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-202026 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] When a plant-derived polyol is contained in the raw material as in the polyurethane foam of Patent Document 1, the molecular weight becomes small in composition and the rebound elastic modulus tends to decrease. Therefore, it is required to contain a plant-derived polyol in the raw material and to improve the rebound elastic modulus of the polyurethane foam.

[0008] The present disclosure has been made in view of the above circumstances, and an object of the present invention is to provide a polyurethane foam containing a plant-derived polyol as a raw material and having high resilience.

[0009] The present disclosure can be implemented in the following ways.

[0010] Means used to solve problems

[0011] [1] A polyurethane foam obtained from a composition containing polyols and polyisocyanates, wherein:

[0012] The polyols contain plant-derived polyols,

[0013] The hydroxyl value of the plant-derived polyol is less than 130 mgKOH / g,

[0014] Isocyanate index is 91 or above,

[0015] The rebound elastic modulus according to JIS K6400-3 is 25% or more.

[0016] Effects of the Invention

[0017] The present invention provides a polyurethane foam containing plant-derived polyol in raw materials and having high resilience. DETAILED DESCRIPTION

[0018] Here, preferred examples of the present disclosure are shown.

[0019] [2] The polyurethane foam according to [1], wherein the plant-derived polyol is a castor oil-derived polyol.

[0020] [3] The polyurethane foam according to [1] or [2], wherein the compressive residual strain according to JIS K6400-44.5.2A method is 10% or less.

[0021] [4] The polyurethane foam according to any one of [1] to [3], wherein the polyols contain a petroleum-derived polyol, and the amount of the plant-derived polyol is 75 parts by mass or less when the total of the petroleum-derived polyol and the plant-derived polyol is 100 parts by mass.

[0022] [5] The polyurethane foam according to any one of [1] to [4], wherein the polyurethane foam is used for bedding.

[0023] The present disclosure is described in detail below. In addition, in this specification, when a numerical range is described using "-", unless otherwise specified, the lower limit and the upper limit are included. For example, in a 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".

[0024] 1. Polyurethane foam

[0025] 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.

[0026] [Plant-derived polyols]

[0027] Plant-derived polyols are preferably castor oil-derived polyols. The "castor oil" in the present disclosure does not include the modified castor oil and dehydrated castor oil described below. 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 the cross-linking (modification) treatment or dehydration treatment based on dibasic acids or the like described below is not implemented. Dehydrated castor oil is made by dehydrating castor oil (non-drying oil) to make a drying oil. Castor oil is an ester of fatty acids and glycerol. Castor oil has ricinoleic acid as the main component, and as other components, it contains unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid, saturated fatty acids such as palmitic acid and stearic acid, and the like.

[0028] The plant-derived polyol may contain modified plant-derived fats and oils as a component using plant-derived fats and oils. Examples of modified plant-derived fats and oils include modified castor oil. The plant-derived polyol preferably contains modified castor oil.

[0029] Modified plant-derived oils such as modified castor oil are obtained by mixing dibasic acid and plant-derived oil to obtain the target property and performing a dehydration condensation reaction. The synthesis of the modified plant-derived oil can be performed using a known method. For example, after the plant-derived oil is dissolved in an arbitrary solvent, a dibasic acid is added. The reaction solution is refluxed through a Dean-Stark apparatus, and the water generated by the reaction is discharged to the outside of the system while performing a dehydration condensation reaction. After the reaction is completed, the target compound can be obtained by removing the solvent under reduced pressure.

[0030] Examples of the dibasic acid include aliphatic dibasic acids, alicyclic dibasic acids, aromatic dibasic acids, or 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, or mixtures thereof.

[0031] Examples of the alicyclic dibasic acid include cyclopentanedicarboxylic acid, cyclohexanedicarboxylic acid, decahydronaphthalene dicarboxylic acid, tetrahydrophthalic acid, nadic acid, and a mixture thereof.

[0032] Examples of the aromatic dibasic acid include terephthalic acid, isophthalic acid, phthalic acid, biphenyl dicarboxylic 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, phenyl indenedicarboxylic acid, and mixtures thereof.

[0033] In addition, 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, itaconic acid, citric 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, hydroxy octadecane dioic acid, dihydroxyoctadecane dioic acid, furancarboxylic acid, hydroxyeicosanedioic acid, dihydroxyeicosanedioic acid, dihydroxyfumaric acid, dihydroxymaleic acid, hydroxycitraconic acid, hydroxymuconic acid, hydroxycyclopentane dicarboxylic acid, hydroxycyclohexane dicarboxylic acid, hydroxytetrahydrophthalic acid, hydroxyterephthalic acid, dihydroxyterephthalic acid, hydroxyisophthalic acid, dihydroxyisophthalic acid, hydroxyphthalic acid, dihydroxyphthalic acid, cochineal acid, hydroxynaphthalene dicarboxylic acid, dihydroxynaphthalene dicarboxylic acid, hydroxydiphenylsulfonyl dicarboxylic acid, meconic acid or a mixture thereof.

[0034] The dibasic acid preferably contains sebacic acid. Sebacic acid is a dibasic acid derived from plants.

[0035] The plant-derived polyol may contain both castor oil (unmodified castor oil) and modified castor oil. When the sum of castor oil and modified castor oil is 100% by mass, the content of modified castor oil in the plant-derived polyol is preferably greater than 62.5% by mass and less than 100% by mass, more preferably from 70% by mass to 100% by mass, and further preferably from 80% by mass to 100% by mass.

[0036] When the sum of petroleum-derived polyols and plant-derived polyols is set to 100 parts by mass, from the perspective of environmental response, the plant-derived polyol is preferably greater than 0 parts by mass, more preferably 30 parts by mass or more, and further preferably 40 parts by mass or more. When the sum of petroleum-derived polyols and plant-derived polyols is set to 100 parts by mass, from the perspective of ensuring strength, the plant-derived polyol is preferably 75 parts by mass or less, more preferably 65 parts by mass or less, and further preferably 55 parts by mass or less. From these viewpoints, when the sum of petroleum-derived polyols and plant-derived polyols is set to 100 parts by mass, the plant-derived polyol is preferably greater than 0 parts by mass and less than 75 parts by mass, more preferably 30 parts by mass or more and less than 65 parts by mass, and further preferably 40 parts by mass or more and less than 55 parts by mass.

[0037] From the viewpoint of promoting the reaction, the hydroxyl value of the plant-derived polyol 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 heat release during foaming, the hydroxyl value of the plant-derived polyol 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 plant-derived polyol 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 plant-derived polyols is the value of the mixture as a whole.

[0038] [Petroleum-derived polyols]

[0039] There is no particular limitation on petroleum-derived polyols. When the sum of petroleum-derived polyols and plant-derived polyols is set to 100 parts by mass, from the viewpoint of ensuring strength, petroleum-derived polyols are preferably greater than 0 parts by mass, more preferably 20 parts by mass or more, and further preferably 40 parts by mass or more. When the sum of petroleum-derived polyols and plant-derived polyols is set to 100 parts by mass, from the viewpoint of coping with the environment, petroleum-derived polyols are preferably less than 80 parts by mass, more preferably less than 70 parts by mass, and further preferably less than 60 parts by mass. From these viewpoints, when the sum of petroleum-derived polyols and plant-derived polyols is set to 100 parts by mass, petroleum-derived polyols are preferably greater than 0 parts by mass and less than 80 parts by mass, more preferably less than 20 parts by mass or less than 70 parts by mass, and further preferably less than 40 parts by mass or less than 60 parts by mass.

[0040] Examples of the petroleum-derived polyol include polyether polyol, polymer polyol, polyester polyol, and the like.

[0041] 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.

[0042] The polyether polyol is preferably a polyether polyol having a weight average molecular weight of 500-125000 (preferably 800-6000, more preferably 1000-3000) and a functional group number of 2-6 (preferably 2 or 3).

[0043] As the polymer polyol, for example, a polymer polyol formed by graft copolymerizing vinyl monomers such as acrylonitrile and styrene into a polyether polyol having a functional group number of 2 or 3 as a base polyol can be appropriately 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 number average molecular weight measured by gel permeation chromatography (GPC) can be used as the number average molecular weight of the polymer polyol.

[0044] 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 condensation polymerization 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.

[0045] [Other polyols]

[0046] 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.

[0047] 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.

[0048] [Polyisocyanates]

[0049] Polyisocyanates are compounds having a plurality of 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 with polyols, and modified isocyanates such as carbodiimide-modified isocyanates can be used. In addition, these polyisocyanates may contain only one kind, or two or more kinds may be contained in combination.

[0050] As polyisocyanates, any of aromatic, alicyclic, and aliphatic isocyanates may be used. In addition, bifunctional isocyanates having two isocyanate groups in one molecule may be used, or trifunctional or higher isocyanates having three or more isocyanate groups in one molecule may be used. 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'-diisocyanate, 2,4'-diphenylmethane diisocyanate (MDI), 2,2'-diphenylmethane diisocyanate (MDI), 3,3'-dimethyl-4,4'-diisocyanate, 2,4'-diphenylmethane diisocyanate (MDI), 2,2'-diphenylmethane diisocyanate, 2,4'-diisocyanate, ...2'-diisocyanate, Aromatic isocyanates such as phenylene 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 butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropyl diisocyanate, methylene diisocyanate, and lysine isocyanate. In addition, examples of bifunctional or higher-functional isocyanates include polymethylene polyphenyl polyisocyanate (polymeric MDI). Examples of trifunctional 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, and triphenylmethane-4,4',4"-triisocyanate. The isocyanates are not limited to one type each, and may be two or more types. For example, one type of aliphatic isocyanate and two types of aromatic isocyanates may be used together.

[0051] Isocyanate index is the equivalent ratio of the isocyanate group of polyisocyanates to the reactive groups such as hydroxyl groups that can react with isocyanate in polyols. Therefore, when the value is less than 100, it means that the reactive groups such as hydroxyl groups are excessive than the isocyanate groups, and when it exceeds 100, it means that the isocyanate groups are excessive than the reactive groups such as hydroxyl groups. From the viewpoint of reaction stability, the isocyanate index (INDEX) of polyisocyanates is more than 91, preferably more than 93, and more preferably more than 95. From the viewpoint of heat release during foaming, the isocyanate index (INDEX) of polyisocyanates is less than 125, preferably less than 115, and more preferably less than 110. From these viewpoints, the isocyanate index (INDEX) of polyisocyanates is more than 91 and less than 125, preferably more than 93 and less than 115, and more preferably more than 95 and less than 110.

[0052] [catalyst]

[0053] The composition preferably contains a catalyst. The catalyst is mainly used to promote the urethanization reaction of polyols and polyisocyanates. As the catalyst, a known catalyst commonly used in 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, acetates, and alkali metal alkoxides.

[0054] When the total amount of petroleum-derived polyol and 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 urethanization reaction can be sufficiently promoted. If it is 5.0 parts by mass or less, the uneven cell structure formed due to excessive promotion of the urethanization reaction can be suppressed.

[0055] [Foam stabilizer]

[0056] The composition preferably contains a foam stabilizer. There is no particular restriction on the foam stabilizer. Preferred foam stabilizers include silicone compounds such as organopolysiloxane, organopolysiloxane-polyoxyalkylene copolymer, polyalkenyl siloxane with polyoxyalkylene side chain, silicone-grease 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. There is no particular restriction on the proportion of the foam stabilizer. When the sum of petroleum-derived polyol and plant-derived polyol is set to 100 parts by mass, the proportion of the foam stabilizer is preferably 0.03 parts by mass or more and 5.0 parts by mass or less.

[0057] [Foaming agent]

[0058] 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. 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 petroleum-derived polyols and plant-derived polyols is set to 100 parts by mass, it is preferably 1 part by mass or more and 10 parts by mass or less. As the hydrohaloolefin, hydrofluoroolefins (HFO) are preferably used.

[0059] [Other ingredients]

[0060] 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 preferably used. As thickeners, for example, calcium carbonate, aluminum hydroxide and magnesium hydroxide may be mentioned.

[0061] 2. Requirements for the rebound modulus

[0062] In the polyurethane foam, the rebound elastic modulus based on the rebound test according to JIS K6400-3 is preferably 25% or more, more preferably 28% or more, further preferably 30% or more, and particularly preferably 32% or more. In the polyurethane foam, the rebound elastic modulus based on the rebound test according to JIS K6400-3 is usually 90% or less.

[0063] 3. Requirements for compressive residual strain

[0064] In the polyurethane foam, the compressive residual strain according to JIS K6400-44.5.2A method is preferably 10% or less, more preferably less than 8%, 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.

[0065] 4. Requirements for elongation

[0066] In the polyurethane foam, the elongation according to JIS K6400-55 is preferably 50% or more, more preferably 75% or more, and further preferably 100% or more. In the polyurethane foam, the elongation according to JIS K6400-55 is usually 500% or less.

[0067] 5. Density requirements

[0068] In polyurethane foam, the density according to JIS K7222 is preferably 15 kg / m3 More preferably 25kg / m 3 More preferably, 30 kg / m 3 In polyurethane foam, the density according to JIS K7222 is preferably 70 kg / m 3 Below, more preferably 50kg / m 3 Below, more preferably 45kg / m 3 Therefore, in polyurethane foam, the density according to JIS K7222 is preferably 15 kg / m 3 Above 70kg / m 3 Below, more preferably 25kg / m 3 Above 50kg / m 3 Below, more preferably 30kg / m 3 Above 45kg / m 3 the following.

[0069] 6. Requirements for hardness

[0070] 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.

[0071] 7. Requirements for ventilation volume

[0072] In the polyurethane foam, the air flow rate according to JIS K6400-7 is preferably 1 L / min or more, more preferably 25 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.

[0073] 8. Requirements for biomass content (Biomass degree) based on the proportion of raw materials

[0074] The biomass content (hereinafter also referred to as the biomass content of the raw materials) based on the 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. In formula (1), the "number of added portions of plant-derived polyols" also includes the number of added portions of any material among 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 degree of the plant-derived polyol is 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, antibacterial 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. The units of "the number of added portions of plant-derived polyols" and "the total number of added portions of the polyurethane resin composition" are parts by mass.

[0075] [Formula 1]

[0076]

[0077] [Formula 2]

[0078]

[0079] In the polyurethane foam, the biomass content of the raw material is preferably 20% or more, more preferably 25% or more, further preferably 30% or more, particularly preferably 40% or more.

[0080] 9. Requirements for biomass content based on the AMS method

[0081] The biomass content of polyurethane foam is based on ASTMD6866-21 and is obtained by measuring the value by accelerator mass spectrometry (AMS method). The standard substance of carbon 14 concentration in the atmosphere in 1950 and the carbon 14 concentration of polyurethane foam are measured and compared as the biomass content. However, the current carbon 14 concentration in the atmosphere is increasing every year, so in order to correct it, the value of carbon 14 concentration is multiplied by a coefficient. The biomass content is calculated according to ASTMD6866-21, and the atmospheric correction factor for 2021, i.e., REF (pMC) = 100.0, is used to calculate the biomass content.

[0082] 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, further preferably 30% or more, particularly preferably 40% or more.

[0083] 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 specification as preferred numerical ranges.

[0084] 10. Method for producing polyurethane foam

[0085] 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 is acceptable. 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.

[0086] 11. Application of polyurethane foam

[0087] 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 cushions used in chairs, sofas, cushioning materials, sound absorbing materials, kitchen sponges, hydroponic cultivation medium for plants, etc.

[0088] 12. Functions and Effects of This Implementation

[0089] In this embodiment, a polyurethane foam having a high rebound elastic modulus can be provided.

[0090] According to the polyurethane foam of this embodiment, foaming properties are excellent.

[0091] According to the polyurethane foam of this embodiment, the biomass content can be increased.

[0092] According to the polyurethane foam of the present embodiment, the compressive residual strain can be reduced.

[0093] According to the polyurethane foam of this embodiment, the elongation can be increased.

[0094] Example

[0095] Next, the above-mentioned embodiment will be described in more detail with reference to Examples and Comparative Examples.

[0096] 1. Manufacture of polyurethane foam

[0097] Polyurethane resin compositions having the proportions shown in Tables 1 to 3 were prepared, and polyurethane foams of Examples and Comparative Examples were manufactured by plate foaming.

[0098] [Table 1]

[0099]

[0100] [Table 2]

[0101]

[0102] [Table 3]

[0103]

[0104] In Table 1-3, the numerical values ​​of the components without units other than the index represent parts by mass.

[0105] Various information about petroleum-derived polyols 1 to 7 and plant-derived polyols 1 and 2 is shown in Table 4 below.

[0106] Plant-derived polyol 2 is a castor oil-derived polyol having a plant-derived degree of 100% and composed of plant-derived polyol 1: sebacic acid = 2 mol: 1 mol. 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 controller, etc., and reacting them under stirring for a predetermined time and a predetermined temperature.

[0107] In Example 1-19, the content of the modified castor oil in the plant-derived polyol was 100 mass % when the total of the castor oil and the modified castor oil was 100 mass %.

[0108] The "OHV" column in Table 4 indicates the hydroxyl value. "Mw" indicates the weight average molecular weight. "Mn" indicates the number average molecular weight.

[0109] [Table 4]

[0110]

[0111] The specific contents of the catalyst, foam stabilizer, blowing agent, and polyisocyanate in Table 1-3 are as follows.

[0112] Catalyst 1: Aliphatic tertiary amine (manufactured by Evonik Japan, DABCO33LSI)

[0113] Catalyst 2: N,N-dimethylaminoethanol (manufactured by Nippon Emulsifier Co., Ltd., amino alcohol 2Mabs)

[0114] Catalyst 3: 6-dimethylamino-1-hexanol (manufactured by Kao Corporation, KAOLIZER No. 25)

[0115] Catalyst 4: Stannous octoate (manufactured by Chengbei Chemical Industry Co., Ltd., MRH-110)

[0116] Foam stabilizer: Organic silicone (manufactured by Dow Corning, SZ-1136)

[0117] Polyisocyanate: Toluene diisocyanate (TDI) 2,4 / 2,6 isomers mixed in a ratio of 80 / 20 (manufactured by Tosoh Corporation, CORONATE T-80)

[0118] 2. Evaluation

[0119] Then, the following evaluations were performed on the obtained polyurethane foams of each Example and each Comparative Example.

[0120] [Biomass content based on the proportion of raw materials]

[0121] The biomass content based on the blending ratio of the raw materials was calculated using the above formulas (1) and (2). The calculation results are shown in the "Biomass content of raw materials" column of Table 1-3.

[0122] [Biomass content based on AMS method]

[0123] The biomass content based on the AMS method is obtained by measurement based on accelerator mass spectrometry (AMS method) based on ASTM D6866-21. The biomass content is 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 of Table 1-3.

[0124] [Foamability]

[0125] The foamability of the polyurethane foam was evaluated based on the following criteria.

[0126] "B": Foaming is good.

[0127] "C": Poor foaming.

[0128] [density]

[0129] The density of the polyurethane foam was determined by a measurement method in accordance with JIS K 7222. The measurement results are shown in the "Density" column of Table 1-3.

[0130] The density of the polyurethane foam was evaluated based on the following criteria.

[0131] "B": 25kg / m 3 above

[0132] "C": less than 25kg / m 3

[0133] [elongation]

[0134] 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 Table 1-3.

[0135] The elongation of the polyurethane foam was evaluated based on the following criteria.

[0136] "A": 100% or more

[0137] "B": 50% or more and less than 100%

[0138] "C": less than 50%

[0139] [Rebound elastic modulus]

[0140] 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 "Rebound elastic modulus" column of Table 1-3.

[0141] The rebound elastic modulus of the polyurethane foam was evaluated according to the following criteria.

[0142] "A": 30% or more

[0143] "B": 25% or more and less than 30%

[0144] "C": less than 25%

[0145] [hardness]

[0146] The hardness of the polyurethane foam was determined by a measurement method in accordance with JIS K6400-26.7 D method. The measurement results are shown in the "Hardness" column of Table 1-3.

[0147] The hardness of the polyurethane foam was evaluated based on the following criteria.

[0148] "B": 20N or more but less than 300N

[0149] "C": less than 20N or greater than 300N

[0150] [Ventilation]

[0151] 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 Table 1-3.

[0152] The air flow rate of the polyurethane foam was evaluated based on the following criteria.

[0153] "A": 50L / min or more

[0154] "B": 1L / min or more and less than 50L / min

[0155] "C": less than 1L / min

[0156] [Compressive residual strain]

[0157] 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 "Compressive Residual Strain" column of Table 1-3.

[0158] The compressive residual strain of the polyurethane foam was evaluated according to the following criteria.

[0159] "A": less than 5%

[0160] "B": 5% or more but less than 10%

[0161] "C": greater than 10%

[0162] [Comprehensive evaluation]

[0163] "A": None of "Evaluation of foamability", "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"

[0164] "B": "C" for any one of "Evaluation of foamability", "Evaluation of density", "Evaluation of elongation", "Evaluation of rebound elastic modulus", "Evaluation of hardness", "Evaluation of air flow", and "Evaluation of compression residual strain"

[0165] 3. Results

[0166] The "Evaluation of rebound elastic modulus" of Example 1-19 was "A" or "B". The "Evaluation of rebound elastic modulus" of Comparative Example 1-3 was "C" or unmeasurable. Example 1-19 contains a plant-derived polyol in the polyurethane resin composition, and the rebound elastic modulus is a high value of 25% or more.

[0167] Examples 1-19 satisfy all of the following requirements ac. Comparative Example 1 does not satisfy the following requirements a and c. Comparative Example 2 does not satisfy the following requirements a and c. Comparative Example 3 does not satisfy the following requirements b and c.

[0168] Requirement a: The hydroxyl value of the plant-derived polyol is 130 mgKOH / g or less

[0169] Requirement b: Isocyanate index is 91 or more

[0170] Requirement c: The rebound elastic modulus according to JIS K6400-3 is 25% or more

[0171] The “comprehensive evaluation” of Examples 1 to 19 was “A.” In Examples 1 to 19, by satisfying the above requirements ac, the foamability, rebound elastic modulus, elongation, and compressive residual strain were well balanced.

[0172] 4. Effects of the Embodiments

[0173] According to the above embodiments, a polyurethane foam having good foamability and a high rebound elastic modulus can be produced.

[0174] Can increase the biomass content of polyurethane foam.

[0175] Can increase the elongation of polyurethane foam.

[0176] Can reduce the compressive residual strain of polyurethane foam.

[0177] 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 plant-derived polyols, The hydroxyl value of the plant-derived polyol is less than 130 mgKOH / g, Isocyanate index is 91 or above, The rebound elastic modulus according to JIS K6400-3 is 25% or more.

2. The polyurethane foam according to claim 1, wherein The plant-derived polyol is castor oil-derived polyol.

3. The polyurethane foam according to claim 1 or 2, wherein The compressive residual strain according to JIS K6400-44.5.2A method is 10% or less.

4. The polyurethane foam according to claim 1 or 2, wherein The polyols contain petroleum-derived polyols, 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.

5. The polyurethane foam according to claim 1 or 2, wherein The polyurethane foam is used for bedding.

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