Urethane prepolymer, polyurethane resin composition, polyurethane foam, and molded article

Abstract

A urethane prepolymer according to the present invention contains a reaction product of a polyisocyanate component and a polyol component. The polyisocyanate component contains an aromatic polyisocyanate. The polyol component contains a plant-based polyol. The plant-based polyol has a structural unit derived from a plant compound. The number average molecular weight of the plant-based polyol is 1000–6000. The structural unit derived from the plant compound is 5–30 mass% of the total amount of the urethane prepolymer.

Description

Urethane prepolymer, polyurethane resin composition, polyurethane foam, and molded article

[0001] This invention relates to urethane prepolymers, polyurethane resin compositions, polyurethane foams, and molded articles.

[0002] Polyurethane foam is obtained by reacting polyisocyanate components and polyol components in the presence of a urethane catalyst and a blowing agent, and is used in a wide range of fields.

[0003] As polyurethane foams, for example, the following low-flammability flexible polyurethane foams have been proposed. More specifically, low-flammability flexible polyurethane foams are obtained by reacting and foaming foaming raw materials. The foaming raw materials contain polyols, polyisocyanates, a blowing agent, and a catalyst. Polyisocyanate prepolymers are used as polyisocyanates. Polyisocyanate prepolymers are reaction products of castor oil polyol and 4,4'-diphenylmethane diisocyanate (see, for example, Patent Document 1 (Example 23)).

[0004] Japanese Patent Publication No. 2009-167255

[0005] On the other hand, when the reaction product of castor oil polyol and 4,4'-diphenylmethane diisocyanate is used as a polyisocyanate, the moldability of the low-flammability flexible polyurethane foam may be poor. More specifically, uniform cells may not be obtained, or defects may occur.

[0006] Furthermore, excellent handling properties are required for polyisocyanates. More specifically, a reduction in the viscosity of polyisocyanates immediately after manufacturing is required.

[0007] The present invention relates to a urethane prepolymer, a polyurethane resin composition, a polyurethane foam, and a molded article having relatively excellent moldability and handling properties.

[0008] The present invention [1] is a urethane prepolymer containing a reaction product of a polyisocyanate component (A) and a polyol component (B), wherein the polyisocyanate component (A) contains an aromatic polyisocyanate, the polyol component (B) contains a plant-derived polyol (b-1), the plant-derived polyol (b-1) has structural units derived from a plant compound, the number average molecular weight of the plant-derived polyol (b-1) is 1000 or more and 6000 or less, and the content ratio of the structural units derived from the plant compound is 5% by mass or more and 30% by mass or less with respect to the total amount of the urethane prepolymer.

[0009] The present invention [2] comprises the urethane prepolymer described in [1] above, wherein the polyisocyanate component (A) contains diphenylmethane diisocyanate.

[0010] The present invention [3] includes the urethane prepolymer described in [1] or [2] above, wherein the structural units derived from the plant compound contain structural units derived from castor oil and / or castor oil fatty acids.

[0011] The present invention [4] includes a urethane prepolymer according to any one of the above [1] to [3], wherein the average number of functional groups of the plant-derived polyol (b-1) is 1.5 or more and 5.0 or less.

[0012] The present invention [5] includes a urethane prepolymer according to any one of the above [1] to [4], wherein the hydroxyl value of the plant-derived polyol (b-1) is 40 mg KOH / g or more and 150 mg KOH / g or less.

[0013] The present invention [6] comprises a urethane prepolymer according to any one of the above [1] to [5], wherein the plant-derived polyol (b-1) contains a plant-derived polyester polyol.

[0014] The present invention [7] comprises a urethane prepolymer according to any one of the above [1] to [6], wherein the polyol component (B) further contains a petroleum-derived polyol (b-2), and the petroleum-derived polyol (b-2) contains a petroleum-derived polyether polyol.

[0015] The present invention [8] comprises the urethane prepolymer described in [7] above, wherein the petroleum-derived polyether polyol has oxyethylene units.

[0016] The present invention [9] includes a polyurethane resin composition comprising a prepolymer component containing a urethane prepolymer as described in any one of the above items [1] to [8] and a resin premix component.

[0017] The present invention

[10] includes the polyurethane resin composition described in [9] above, wherein the resin premix component contains a polyol component (C), and the polyol component (C) contains a plant-derived polyol (c-1).

[0018] The present invention

[11] comprises the polyurethane resin composition described in

[10] above, wherein the polyol component (C) further contains a petroleum-derived polyol (c-2).

[0019] The present invention

[12] includes a polyurethane foam containing a reaction product of a polyurethane resin composition described in any one of the above items [9] to

[11] .

[0020] The present invention

[13] includes the polyurethane foam described in

[12] above, wherein the content ratio of structural units derived from the plant compound is 5% by mass or more and 50% by mass or less with respect to the total amount of the resin portion of the polyurethane foam.

[0021] The present invention

[14] includes a molded article comprising the polyurethane foam described in

[12] or

[13] above.

[0022] The present invention

[15] includes the molded article described in

[14] above, which is a cushioning material for vehicles.

[0023] The present invention

[16] is a urethane prepolymer containing a reaction product of a polyisocyanate component (A) and a polyol component (B), wherein the polyisocyanate component (A) contains an aromatic polyisocyanate, the polyol component (B) contains a plant-derived polyol (b-1), the plant-derived polyol (b-1) has structural units derived from plant compounds, the number average molecular weight of the plant-derived polyol (b-1) is 1000 or more and 6000 or less, and the content ratio of bio-derived carbon to the total carbon contained in the urethane prepolymer is 5% or more and 30% or less.

[0024] In the urethane prepolymer and polyurethane resin composition of the present invention, the polyisocyanate component (A) contains an aromatic polyisocyanate. The polyol component (B) contains a plant-derived polyol (b-1). The plant-derived polyol (b-1) has structural units derived from plant compounds, and the number-average molecular weight of the plant-derived polyol (b-1) is within a predetermined range. Furthermore, the content ratio of structural units derived from plant compounds is within a predetermined range relative to the total amount of the urethane prepolymer, and / or the content ratio of bio-derived carbon is within a predetermined range relative to the total carbon contained in the urethane prepolymer.

[0025] Therefore, the urethane prepolymer and polyurethane resin composition of the present invention possess both relatively excellent moldability and relatively excellent handling properties.

[0026] Furthermore, the polyurethane foam and molded articles of the present invention are obtained using the above-mentioned urethane prepolymer and polyurethane resin composition. Therefore, the above-mentioned polyurethane foam and molded articles have excellent productivity.

[0027] Embodiments of the present disclosure are described below. These descriptions and examples are illustrative of embodiments and do not limit the scope of embodiments. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, numerical ranges expressed using "~" mean a range that includes the numbers before and after "~" as the lower and upper limits. In numerical ranges described in stages in the present disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. In numerical ranges described in the present disclosure, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. In the present disclosure, each component may contain multiple types of the corresponding substance. When the amount of each component in the composition is referred to in the present disclosure, if there are multiple types of the substance corresponding to each component in the composition, unless otherwise specified, it means the total amount of the multiple types of substances present in the composition. In the present disclosure, "mass%" and "weight%" are synonymous, and "parts by mass" and "parts by weight" are synonymous. In the present disclosure, "%" indicating the amount of a component is on a mass basis unless otherwise specified.

[0028] 1. Urethane Prepolymer The urethane prepolymer of this disclosure has free isocyanate groups at its molecular ends. That is, the urethane prepolymer is an isocyanate group-terminated prepolymer.

[0029] The urethane prepolymer contains a reaction product of a polyisocyanate component (A) and a polyol component (B). Preferably, the urethane prepolymer is a reaction product of a polyisocyanate component (A) and a polyol component (B).

[0030] (1) Polyisocyanate component (A) (1-1) Aromatic polyisocyanate Polyisocyanate component (A) contains an aromatic polyisocyanate as an essential component. Examples of aromatic polyisocyanates include aromatic polyisocyanate monomers and aromatic polyisocyanate derivatives.

[0031] Examples of aromatic polyisocyanate monomers include diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), toluidine diisocyanate (TODI), paraphenylenedi diisocyanate, and naphthalene diisocyanate (NDI). These can be used individually or in combination of two or more. Diphenylmethane diisocyanate (MDI) is preferred. In other words, the polyisocyanate component (A) preferably contains diphenylmethane diisocyanate (MDI). Note that diphenylmethane diisocyanate (MDI) is a dinuclear compound. A dinuclear compound means a compound that contains two benzene rings in one molecule.

[0032] Examples of aromatic polyisocyanate derivatives include modified compounds obtained by modifying the above-mentioned aromatic polyisocyanate monomers using known methods. Examples of modified compounds include isocyanurate modified compounds, allophanate modified compounds, polyol modified compounds, biuret modified compounds, urea modified compounds, oxadiazinetrione modified compounds, and carbodiimide modified compounds. Another example of an aromatic polyisocyanate derivative is polymethylene polyphenyl polyisocyanate (p-MDI). These can be used individually or in combination of two or more. Preferably, examples include carbodiimide modified diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate (p-MDI) with three or more nuclei. In other words, the polyisocyanate component (A) preferably contains carbodiimide modified diphenylmethane diisocyanate and / or polymethylene polyphenyl polyisocyanate (p-MDI) with three or more nuclei. Note that "three or more nuclei" refers to compounds containing three or more benzene rings in a single molecule.

[0033] Preferably, the aromatic polyisocyanate is a combination of an aromatic polyisocyanate monomer and an aromatic polyisocyanate derivative, and more preferably, a combination of diphenylmethane diisocyanate (MDI), a carbodiimide modified form of diphenylmethane diisocyanate, and polymethylene polyphenyl polyisocyanate (p-MDI).

[0034] In other words, the polyisocyanate component (A) preferably contains an aromatic polyisocyanate monomer and an aromatic polyisocyanate derivative, and particularly preferably contains diphenylmethane diisocyanate (MDI), a carbodiimide-modified product of diphenylmethane diisocyanate, and polymethylene polyphenyl polyisocyanate (p-MDI). The content ratios of these components are appropriately set according to the purpose and application.

[0035] The method for obtaining the aromatic polyisocyanate is not particularly limited, and any known method can be employed. Examples of methods for obtaining aromatic polyisocyanates include the phosgene method and the urea method, with the phosgene method being preferred.

[0036] (1-2) Other polyisocyanates The polyisocyanate component (A) may contain other polyisocyanates as optional components within a range that does not impair the excellent effects of the present disclosure. Other polyisocyanates are polyisocyanates excluding the above-mentioned aromatic polyisocyanates (the same applies hereinafter).

[0037] More specifically, examples of other polyisocyanates include other polyisocyanate monomers and other polyisocyanate derivatives.

[0038] Examples of other polyisocyanate monomers include aliphatic polyisocyanate monomers and araliphatic polyisocyanate monomers. Examples of aliphatic polyisocyanate monomers include linear aliphatic polyisocyanate monomers and alicyclic polyisocyanate monomers. Examples of linear aliphatic polyisocyanate monomers include ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate (PDI), and hexamethylene diisocyanate (HDI). Examples of alicyclic polyisocyanate monomers include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), methylenebis(cyclohexyl isocyanate) (H １２MDI), and bis(isocyanatomethyl)cyclohexane (H ６ XDI). Examples of araliphatic polyisocyanate monomers include xylylene diisocyanate (XDI) and tetramethyl xylylene diisocyanate (TMXDI). These may be used alone or in combination of two or more types.

[0039] Examples of other polyisocyanate derivatives include the above-modified products obtained by modifying other polyisocyanate monomers by known methods. These may be used alone or in combination of two or more types.

[0040] The content of other polyisocyanates is adjusted within a range that does not impair the excellent effects of the present disclosure. More specifically, the content of other polyisocyanates is, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, particularly preferably 0% by mass, relative to the total amount of the polyisocyanate component (A). That is, it is particularly preferable that the polyisocyanate component (A) does not contain other polyisocyanates.

[0041] In other words, the content of the aromatic polyisocyanate is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, particularly preferably 100% by mass, relative to the total amount of the polyisocyanate component (A). That is, it is particularly preferable that the polyisocyanate component (A) consists of an aromatic polyisocyanate.

[0042] (2) Polyol component (B) (2-1) Plant-derived polyol (b-1) The polyol component (B) contains a plant-derived polyol (b-1) as an essential component. The plant-derived polyol (b-1) is a polyol having a structural unit derived from a vegetable compound in the molecule.

[0043] The vegetable compound is a compound derived from plants. That is, the vegetable compound is a biomass raw material.

[0044] Examples of plant-derived compounds include vegetable oils and vegetable oil fatty acids. Examples of vegetable oils include castor oil, soybean oil, palm oil, sesame oil, rapeseed oil, coconut oil, and hydrogenated versions thereof. Examples of vegetable oil fatty acids include fatty acids obtained by saponification of the above vegetable oils, more specifically castor oil fatty acids, soybean oil fatty acids, palm oil fatty acids, sesame oil fatty acids, rapeseed oil fatty acids, and coconut oil fatty acids, with castor oil fatty acids being preferred. Examples of castor oil fatty acids include palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid, and dihydroxystearic acid, with ricinoleic acid being preferred. These can be used alone or in combination of two or more. Examples of plant-derived compounds include castor oil and castor oil fatty acids, with castor oil fatty acids being more preferred. In other words, the plant-derived compound preferably contains castor oil and / or castor oil fatty acids, and more preferably contains castor oil fatty acids.

[0045] In other words, structural units derived from plant compounds include, for example, structural units derived from vegetable oil and / or vegetable oil fatty acids, preferably structural units derived from castor oil and / or castor oil fatty acids, and more preferably structural units derived from castor oil fatty acids. That is, the structural units derived from plant compounds contain, for example, structural units derived from vegetable oil and / or vegetable oil fatty acids, preferably structural units derived from castor oil and / or castor oil fatty acids, and more preferably structural units derived from castor oil fatty acids. Furthermore, the structural units derived from plant compounds are more preferably composed of structural units derived from castor oil and / or castor oil fatty acids, and particularly preferably composed of structural units derived from castor oil fatty acids.

[0046] More specifically, plant-derived polyols (b-1) include, for example, plant-derived polyester polyols. In other words, plant-derived polyols (b-1) preferably contain plant-derived polyester polyols, and more preferably consist of plant-derived polyester polyols.

[0047] (2-1-1) Plant-derived polyester polyols Examples of plant-derived polyester polyols include polyester polyols having structural units derived from vegetable oil fatty acids. More specifically, examples of plant-derived polyester polyols include ester condensates of polyhydric alcohols and vegetable oil fatty acids.

[0048] Examples of polyhydric alcohols include dihydric alcohols, trihydric alcohols, tetrahydric alcohols, pentahydric alcohols, hexahydric alcohols, heptahydric alcohols, and octahydric alcohols. Examples of dihydric alcohols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethylpentanediol, 3,3-dimethylolheptane, alkane (C7-20) diols, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, hydrogenated bisphenol A, 1,4-dihydroxy-2-butene, 2,6-dimethyl-1-octen-3,8-diol, bisphenol A, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of trihydric alcohols include glycerin, trimethylolpropane, and triisopropanolamine. Examples of tetrahydric alcohols include tetramethylolmethane (pentaerythritol) and diglycerin. Examples of pentahydric alcohols include xylitol. Examples of hexahydric alcohols include sorbitol, mannitol, allitol, isitol, dalucitol, althritol, inositol, and dipentaerythritol. Examples of heptahydric alcohols include perseitol. Examples of octahydric alcohols include sucrose. Examples of polyhydric alcohols include dihydric to hexahydric polyoxyalkylene (carbon 2 to 3) polyols, more specifically, polyoxyethylene polyols, polyoxypropylene polyols, and oxyethylene-oxypropylene copolymers (random or block copolymers). The number-average molecular weight (GPC measurement) of polyoxyalkylene (C2-3) polyols is, for example, 200 to 2000, preferably 400 to 1000, and more preferably 500 to 1000. These are used individually or in combination of two or more types.

[0049] Preferably, dihydric to hexahydric alcohols are used as polyhydric alcohols. Also preferably, dihydric to hexahydric polyoxyalkylene (C2-3) polyols are used as polyhydric alcohols. From the viewpoint of tensile strength, elongation, and tear strength of the polyurethane foam (described later), dihydric alcohols and dihydric polyoxyalkylene (C2-3) polyols are used as polyhydric alcohols. Also, from the viewpoint of hardness and rebound elasticity of the polyurethane foam (described later), trihydric to tetrahydric alcohols and trihydric to tetrahydric polyoxyalkylene (C2-3) polyols are used as polyhydric alcohols.

[0050] Examples of vegetable oil fatty acids include fatty acids that do not contain hydroxyl groups in one molecule (hereinafter referred to as hydroxyl-free vegetable oil fatty acids) and fatty acids that contain one or more hydroxyl groups in one molecule (hereinafter referred to as hydroxyl-containing vegetable oil fatty acids).

[0051] Examples of hydroxyl-free vegetable oil fatty acids include palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. These can be used individually or in combination of two or more types.

[0052] Examples of hydroxyl group-containing vegetable oil fatty acids include vegetable oil fatty acids containing one hydroxyl group per molecule (hereinafter referred to as monohydroxy vegetable oil fatty acids) and vegetable oil fatty acids containing multiple hydroxyl groups per molecule (hereinafter referred to as polyhydroxy vegetable oil fatty acids). Examples of monohydroxy vegetable oil fatty acids include hydroxyoleic acid (ricinoleic acid), hydroxylinoleic acid, and hydroxylinolenic acid. An example of polyhydroxy vegetable oil fatty acid is dihydroxystearic acid. These can be used individually or in combination of two or more types.

[0053] Preferably, the vegetable oil fatty acid is monohydroxy vegetable oil fatty acid, and more preferably, ricinoleic acid. That is, the vegetable oil fatty acid preferably contains monohydroxy vegetable oil fatty acid, and more preferably contains ricinoleic acid.

[0054] In other words, plant-derived polyester polyols preferably have structural units derived from monohydroxy vegetable oil fatty acids, and more preferably have structural units derived from ricinoleic acid.

[0055] The content of structural units derived from monohydroxy vegetable oil fatty acids is, for example, 80 to 99% by mass, preferably 90 to 95% by mass, relative to the total amount of plant-derived polyester polyol. The content of structural units derived from monohydroxy vegetable oil fatty acids can be determined by saponifying the plant-derived polyester polyol and analyzing the resulting decomposition composition using a known method.

[0056] (2-1-2) Method for producing plant-derived polyester polyols The method for producing plant-derived polyester polyols is not particularly limited. For example, plant-derived polyester polyols can be produced by esterifying the above-mentioned polyhydric alcohol and the above-mentioned vegetable oil fatty acid using a known method.

[0057] Furthermore, for example, an ester condensate of a polyhydric alcohol and a vegetable oil fatty acid (e.g., vegetable oil) can be further subjected to ester condensation of the vegetable oil fatty acid by a known method.

[0058] The mixing ratio of polyhydric alcohol and vegetable oil fatty acid, as well as the reaction conditions, are adjusted as appropriate depending on the purpose and application. For example, the ratio of vegetable oil fatty acid to 1 mole of polyhydric alcohol is, for example, 1 to 10 moles, preferably 1.5 to 8 moles, and more preferably 1.5 to 6 moles.

[0059] (2-1-3) Physical properties of plant-derived polyol (b-1) [Hydroxyl value] Plant-derived polyol (b-1) preferably has a predetermined hydroxyl value.

[0060] The hydroxyl value of the plant-derived polyol (b-1) is, for example, 20 mg KOH / g or more, preferably 40 mg KOH / g or more, more preferably 45 mg KOH / g or more, and even more preferably 50 mg KOH / g or more. Alternatively, the hydroxyl value of the plant-derived polyol (b-1) is, for example, 200 mg KOH / g or less, preferably 150 mg KOH / g or less, more preferably 100 mg KOH / g or less, and even more preferably 70 mg KOH / g or less.

[0061] In other words, the hydroxyl value of the plant-derived polyol (b-1) is, for example, 20 mg KOH / g or more and 200 mg KOH / g or less, preferably 40 mg KOH / g or more and 150 mg KOH / g or less, more preferably 45 mg KOH / g or more and 100 mg KOH / g or less, and even more preferably 50 mg KOH / g or more and 70 mg KOH / g or less.

[0062] The hydroxyl value can be measured in accordance with Method B (phthalation method) of JIS K 1557-1 (2007).

[0063] When two or more polyols are used in combination, the overall hydroxyl value is calculated based on the amount of each polyol used. More specifically, the overall hydroxyl value is the weighted average of the hydroxyl values ​​of each polyol based on their combined mass (the same applies hereafter).

[0064] [Average number of functional groups (average number of hydroxyl groups)] The plant-derived polyol (b-1) preferably has a predetermined average number of functional groups.

[0065] The average number of functional groups (average number of hydroxyl groups) of the plant-derived polyol (b-1) is, for example, 1.5 or more, preferably 1.6 or more, and more preferably 1.7 or more. Alternatively, the average number of functional groups (average number of hydroxyl groups) of the plant-derived polyol (b-1) is, for example, 5.0 or less, preferably 4.8 or less, more preferably 4.6 or less, and even more preferably 4.4 or less.

[0066] In other words, the average number of functional groups (average number of hydroxyl groups) of the plant-derived polyol (b-1) is, for example, 1.5 or more and 5.0 or less, preferably 1.6 or more and 4.8 or less, more preferably 1.7 or more and 4.6 or less, and even more preferably 1.7 or more and 4.4 or less.

[0067] The average number of functional groups (average number of hydroxyl groups) can be calculated based on the type of raw material and the preparation method.

[0068] When two or more polyols are used in combination, the overall average number of functional groups (average number of hydroxyl groups) is calculated based on the amount of each polyol used. More specifically, the overall average number of functional groups (average number of hydroxyl groups) is obtained by weighting the average number of functional groups (average number of hydroxyl groups) of each polyol based on the amount of each polyol used (the same applies hereafter).

[0069] [Number-average molecular weight] The plant-derived polyol (b-1) has a predetermined number-average molecular weight from the viewpoint of moldability.

[0070] More specifically, from the viewpoint of moldability, the number average molecular weight (molecular weight in terms of polyethylene glycol) of the plant-derived polyol (b-1) is 1000 or more, and from the viewpoint of the mechanical properties of the polyurethane foam (described later), it is preferably 1200 or more, more preferably 1500 or more. Also, from the viewpoint of moldability, the number average molecular weight (molecular weight in terms of polyethylene glycol) of the plant-derived polyol (b-1) is 6000 or less, and from the viewpoint of the mechanical properties of the polyurethane foam (described later), it is preferably 5500 or less, more preferably 5000 or less.

[0071] In other words, from the viewpoint of moldability, the number average molecular weight (molecular weight in terms of polyethylene glycol) of the plant-derived polyol (b-1) is 1000 or more and 6000 or less, and from the viewpoint of the mechanical properties of the polyurethane foam (described later), it is preferably 1200 or more and 5500 or less, more preferably 1500 or more and 5000 or less.

[0072] The number-average molecular weight of a polyol can be calculated based on the average number of functional groups (average number of hydroxyl groups) and the hydroxyl value of the polyol, using the following formula.

[0073] Number-average molecular weight = 56100 × average number of functional groups (average number of hydroxyl groups) / hydroxyl value

[0074] Furthermore, the number-average molecular weight can also be determined as the molecular weight equivalent to polyethylene glycol by a known gel permeation chromatography method (the same applies hereafter).

[0075] When two or more polyols are used in combination, the overall number-average molecular weight is calculated based on the amount of each polyol used. More specifically, the overall number-average molecular weight is the weighted average of the number-average molecular weights of each polyol, based on the number of moles used (the same applies hereafter).

[0076] [Biomass content] Plant-derived polyol (b-1) preferably has a predetermined biomass content from the viewpoint of handling. The biomass content is the percentage of structural units derived from plant compounds (based on dry mass (hereinafter the same)).

[0077] In other words, plant-derived polyol (b-1) has structural units derived from plant compounds in its molecule. Hereafter, the percentage of structural units derived from plant compounds (based on dry mass (the same applies hereinafter)) may be referred to as the biomass content. Furthermore, plant-derived polyol (b-1) is adjusted to a predetermined range from the viewpoint of handling.

[0078] More specifically, from the viewpoint of handling, the content of structural units derived from plant compounds (i.e., biomass content) is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, relative to the total amount of plant-derived polyol (b-1). Also, from the viewpoint of handling, the content of structural units derived from plant compounds (i.e., biomass content) is, for example, 100% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 87% by mass or less, relative to the total amount of plant-derived polyol (b-1).

[0079] In other words, from the viewpoint of handling, the content of structural units derived from plant compounds (i.e., biomass content) is, for example, 50% by mass or more and 100% by mass or less, preferably 60% by mass or more and 95% by mass or less, more preferably 70% by mass or more and 90% by mass or less, and even more preferably 80% by mass or more and 87% by mass or less, relative to the total amount of plant-derived polyol (b-1).

[0080] In addition, in plant-derived polyol (b-1), the proportion of structural units derived from plant compounds is calculated based on the molecular structure of plant-derived polyol (b-1) and the preparation formula, in accordance with the examples described later.

[0081] (2-2) Petroleum-derived polyol (b-2) Polyol component (B) may further contain petroleum-derived polyol (b-2) in addition to plant-derived polyol (b-1). From the viewpoint of hardness and rebound elasticity of the polyurethane foam (described later), it is preferable that polyol component (B) further contains petroleum-derived polyol (b-2).

[0082] Petroleum-derived polyols (b-2) are polyols that do not have structural units derived from plant compounds. In other words, petroleum-derived polyols (b-2) are non-plant-derived polyols.

[0083] More specifically, petroleum-derived polyols (b-2) include, for example, petroleum-derived macropolyols. Examples of petroleum-derived macropolyols include petroleum-derived polyether polyols, petroleum-derived polyester polyols, petroleum-derived polycarbonate polyols, petroleum-derived polyurethane polyols, epoxy polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These can be used individually or in combination of two or more. From the viewpoint of hardness and rebound elasticity of polyurethane foam (described later), petroleum-derived polyols (b-2) preferably contain petroleum-derived polyether polyols.

[0084] (2-2-1) Petroleum-derived polyether polyols Examples of petroleum-derived polyether polyols include polyoxyalkylene (C2-C3) polyols and polytetramethylene ether polyols, with polyoxyalkylene (C2-C3) polyols being preferred. That is, petroleum-derived polyether polyols preferably have oxyalkylene (C2-C3) units.

[0085] Examples of polyoxyalkylene (C2-C3) polyols include addition polymerization products of C2-C3 alkylene oxides to known initiators (low molecular weight polyols and / or low molecular weight polyamines).

[0086] Examples of alkylene oxides having 2 to 3 carbon atoms include ethylene oxide, trimethylene oxide, and propylene oxide. From the viewpoint of the mechanical properties of polyurethane foam (described later), preferably the alkylene oxide contains ethylene oxide, and more preferably contains both ethylene oxide and propylene oxide. That is, from the viewpoint of the hardness and rebound elasticity of polyurethane foam (described later), the petroleum-derived polyether polyol preferably has oxyethylene units, and more preferably has both oxyethylene units and oxypropylene units.

[0087] More specifically, polyoxyalkylene (C2-3) polyols include polyethylene glycol, polypropylene glycol, and propylene oxide-ethylene oxide copolymers. Examples of propylene oxide-ethylene oxide copolymers include random copolymers and block copolymers. These can be used individually or in combination of two or more.

[0088] From the viewpoint of hardness and rebound elasticity of polyurethane foam (described later), petroleum-derived polyol (b-2) is preferably a propylene oxide-ethylene oxide copolymer, and more preferably a propylene oxide-ethylene oxide random copolymer.

[0089] In petroleum-derived polyether polyols, the content ratio of oxyethylene units and oxypropylene units is not particularly limited and is set as appropriate depending on the purpose and application.

[0090] For example, from the viewpoint of hardness and rebound elasticity of polyurethane foam (described later), the content of oxyethylene units is, for example, 10% by mass or more and 99% by mass or less, preferably 30% by mass or more and 90% by mass or less, more preferably 50% by mass or more and 85% by mass or less, and even more preferably 70% by mass or more and 80% by mass or less, relative to the total amount of oxyalkylene units.

[0091] Furthermore, from the viewpoint of the hardness and rebound elasticity of the polyurethane foam (described later), the content of oxypropylene units is, for example, 1% by mass or more and 90% by mass or less, preferably 10% by mass or more and 70% by mass or less, more preferably 15% by mass or more and 50% by mass or less, and more preferably 20% by mass or more and 30% by mass or less, relative to the total amount of oxyalkylene units.

[0092] (2-2-2) Method for producing petroleum-derived polyether polyols The method for producing petroleum-derived polyether polyols is not particularly limited. For example, a polyoxyalkylene (C2-3) polyol as a petroleum-derived polyether polyol can be obtained by addition polymerization of a C2-C3 alkylene oxide to a known initiator (low molecular weight polyol and / or low molecular weight polyamine) using a known method.

[0093] (2-2-3) Physical properties of petroleum-derived polyol (b-2) [Hydroxyl value] Petroleum-derived polyol (b-2) preferably has a predetermined hydroxyl value.

[0094] The hydroxyl value of petroleum-derived polyol (b-2) is, for example, 20 mg KOH / g or more, preferably 40 mg KOH / g or more, more preferably 45 mg KOH / g or more, and even more preferably 50 mg KOH / g or more. Alternatively, the hydroxyl value of petroleum-derived polyol (b-2) is, for example, 200 mg KOH / g or less, preferably 150 mg KOH / g or less, more preferably 100 mg KOH / g or less, and even more preferably 70 mg KOH / g or less.

[0095] In other words, the hydroxyl value of the petroleum-derived polyol (b-2) is, for example, 20 mg KOH / g or more and 200 mg KOH / g or less, preferably 40 mg KOH / g or more and 150 mg KOH / g or less, more preferably 45 mg KOH / g or more and 100 mg KOH / g or less, and even more preferably 50 mg KOH / g or more and 70 mg KOH / g or less.

[0096] [Average number of functional groups (average number of hydroxyl groups)] The petroleum-derived polyol (b-2) preferably has a predetermined average number of functional groups.

[0097] The average number of functional groups (average number of hydroxyl groups) of petroleum-derived polyol (b-2) is, for example, 1.5 or more, preferably 1.8 or more, more preferably 2.0 or more, and even more preferably 2.5 or more. Alternatively, the average number of functional groups (average number of hydroxyl groups) of petroleum-derived polyol (b-2) is, for example, 5.0 or less, preferably 4.0 or less, and more preferably 3.5 or less.

[0098] In other words, the average number of functional groups (average number of hydroxyl groups) of the petroleum-derived polyol (b-2) is, for example, 1.5 or more and 5.0 or less, preferably 1.8 or more and 4.0 or less, more preferably 2.0 or more and 3.5 or less, and even more preferably 2.5 or more and 3.5 or less.

[0099] [Number-average molecular weight] The petroleum-derived polyol (b-2) preferably has a predetermined number-average molecular weight.

[0100] The number-average molecular weight (molecular weight in terms of polyethylene glycol) of the petroleum-derived polyol (b-2) is, for example, 1,000 or more, preferably 1,500 or more, and more preferably 2,000 or more. Alternatively, the number-average molecular weight (in terms of polyethylene glycol) of the petroleum-derived polyol (b-2) is, for example, 6,000 or less, preferably 5,000 or less, and more preferably 4,000 or less.

[0101] In other words, the number-average molecular weight (molecular weight in terms of polyethylene glycol) of the petroleum-derived polyol (b-2) is, for example, 1000 to 6000, preferably 1500 to 5000, and more preferably 2000 to 4000.

[0102] (2-3) Content ratio of plant-derived polyol and petroleum-derived polyol In polyol component (B), the content ratio of plant-derived polyol (b-1) and petroleum-derived polyol (b-2) is not particularly limited, but is adjusted within a range that yields a urethane prepolymer having the biomass content described later.

[0103] More specifically, the content of plant-derived polyol (b-1) is, for example, 10% by mass or more and 100% by mass or less, preferably 30% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 100% by mass or less, relative to the total amount of plant-derived polyol (b-1) and petroleum-derived polyol (b-2).

[0104] In other words, the content of petroleum-derived polyol (b-2) is, for example, 0% by mass or more and 90% by mass or less, preferably 0% by mass or more and 70% by mass or less, and more preferably 0% by mass or more and 50% by mass or less, relative to the total amount of plant-derived polyol (b-1) and petroleum-derived polyol (b-2).

[0105] From the viewpoint of tensile strength, elongation, and tear strength of the polyurethane foam (described later), the content of plant-derived polyol (b-1) is more preferably 70% to 100% by mass, even more preferably 90% to 100% by mass, and particularly preferably 100% by mass, relative to the total amount of plant-derived polyol (b-1) and petroleum-derived polyol (b-2).

[0106] In other words, from the viewpoint of tensile strength, elongation, and tear strength of the polyurethane foam (described later), the content of petroleum-derived polyol (b-2) is more preferably 0% to 30% by mass, more preferably 0% to 10% by mass, and most preferably 0% by mass, relative to the total amount of plant-derived polyol (b-1) and petroleum-derived polyol (b-2).

[0107] In other words, from the viewpoint of tensile strength, elongation, and tear strength of the polyurethane foam (described later), the polyol component (B) is particularly preferably a plant-derived polyol (b-1).

[0108] Furthermore, from the viewpoint of hardness and rebound elasticity of the polyurethane foam (described later), the content of plant-derived polyol (b-1) is more preferably 50% by mass or more and 90% by mass or less, more preferably 50% by mass or more and 80% by mass or less, and particularly preferably 50% by mass or more and 70% by mass or less, relative to the total amount of plant-derived polyol (b-1) and petroleum-derived polyol (b-2).

[0109] In other words, from the viewpoint of the hardness and rebound elasticity of the polyurethane foam (described later), the content of petroleum-derived polyol (b-2) is more preferably 10% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 50% by mass or less, and particularly preferably 30% by mass or more and 50% by mass or less, relative to the total amount of plant-derived polyol (b-1) and petroleum-derived polyol (b-2).

[0110] In other words, from the viewpoint of the hardness and rebound elasticity of the polyurethane foam (described later), the polyol component (B) is particularly preferably composed of a plant-derived polyol (b-1) and a petroleum-derived polyol (b-2).

[0111] (3) Method for producing urethane prepolymer The urethane prepolymer contains a reaction product of a polyisocyanate component (A) and a polyol component (B). Preferably, the urethane prepolymer is a reaction product of a polyisocyanate component (A) and a polyol component (B).

[0112] The method for reacting the polyisocyanate component (A) and the polyol component (B) is not particularly limited. For example, the polyisocyanate component (A) and the polyol component (B) are mixed in a predetermined ratio and then reacted.

[0113] Furthermore, the blending ratio of the polyisocyanate component (A) and the polyol component (B) is adjusted so that the content of structural units derived from plant compounds in the urethane prepolymer (i.e., biomass content) falls within a predetermined range. Details regarding the content of structural units derived from plant compounds (i.e., biomass content) will be described later.

[0114] Furthermore, the mixing ratio of the polyisocyanate component (A) and the polyol component (B) is adjusted, for example, based on the equivalent ratio (NCO / OH) of the isocyanate groups (NCO) of the polyisocyanate component (A) to the hydroxyl groups (OH) of the polyol component (B).

[0115] More specifically, the equivalent ratio (NCO / OH) of the isocyanate group (NCO) of the polyisocyanate component (A) to the hydroxyl group (OH) of the polyol component (B) is, for example, 25.0 to 50.0, preferably 30.0 to 47.5, and more preferably 35.0 to 45.0.

[0116] Furthermore, the mixing ratio of polyisocyanate component (A) and polyol component (B) can be adjusted, for example, by mass.

[0117] For example, from the viewpoint of moldability and handling properties, the mass ratio of the polyol component (B) to the total amount of the polyisocyanate component (A) is, for example, 2.0% by mass or more, preferably 3.0% by mass or more, more preferably 5.0% by mass or more, and even more preferably 10.0% by mass or more. Also, from the viewpoint of moldability and handling properties, the mass ratio of the polyol component (B) to the total amount of the polyisocyanate component (A) is, for example, 40.0% by mass or less, preferably 35.0% by mass or less, more preferably 30.0% by mass or less, and even more preferably 25.0% by mass or less.

[0118] In other words, from the viewpoint of moldability and handling properties, the mass ratio of the polyol component (B) to the total amount of the polyisocyanate component (A) is, for example, 2.0% by mass or more and 40.0% by mass or less, preferably 3.0% by mass or more and 35.0% by mass or less, more preferably 5.0% by mass or more and 30.0% by mass or less, and even more preferably 10.0% by mass or more and 25.0% by mass or less.

[0119] Then, a urethane prepolymer is obtained by urethane-forming the polyisocyanate component (A) and the polyol component (B). The reaction conditions in the urethane-forming reaction are not particularly limited. For example, the reaction temperature is, for example, 70 to 90°C, and the reaction time is, for example, 1 to 5 hours.

[0120] Furthermore, known urethane catalysts may be added to the urethane reaction as needed. The amount and timing of the urethane catalyst addition are set appropriately according to the purpose and application. After the urethane reaction, unreacted components (e.g., unreacted polyisocyanate component (A)) can be removed by known removal methods as needed. Examples of removal methods include extraction and distillation.

[0121] (4) Physical properties of urethane prepolymers [Biomass content] Urethane prepolymers have structural units derived from plant compounds. The content ratio of structural units derived from plant compounds (i.e., biomass content) is adjusted from the viewpoint of moldability and handling properties.

[0122] More specifically, from the viewpoint of moldability and handling properties, the content of structural units derived from plant compounds (i.e., biomass content) is 5% by mass or more, preferably 8% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more, relative to the total amount of the urethane prepolymer. Furthermore, from the viewpoint of moldability and handling properties, the content of structural units derived from plant compounds (i.e., biomass content) is 30% by mass or less, preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 17% by mass or less, relative to the total amount of the urethane prepolymer.

[0123] In other words, from the viewpoint of moldability and handling properties, the content of structural units derived from plant compounds (i.e., biomass content) is 5% by mass or more and 30% by mass or less, preferably 8% by mass or more and 25% by mass or less, more preferably 10% by mass or more and 20% by mass or less, and even more preferably 12% by mass or more and 17% by mass or less, relative to the total amount of urethane prepolymer.

[0124] [Content of bio-derived carbon] Urethane prepolymers contain bio-derived carbon (carbon atoms (hereinafter the same)). Bio-derived carbon is carbon derived from living organisms (animals and plants) and is distinct from petroleum-derived carbon. More specifically, bio-derived carbon contains carbon-14 (C14; radioactive carbon), which is a radioactive isotope of carbon, while petroleum-derived carbon contains almost no carbon-14 (C14). Therefore, the content of bio-derived carbon can be determined by measuring the concentration of carbon-14 (C14) in the urethane prepolymer.

[0125] The proportion of bio-derived carbon relative to the total carbon contained in the urethane prepolymer is, for example, 5% to 30%, preferably 8% to 25%, and more preferably 10% to 20%.

[0126] The proportion of bio-derived carbon relative to the total carbon content in the urethane prepolymer is measured, for example, in accordance with Method B of ASTM D6866-24.

[0127] The proportion of structural units derived from plant compounds (i.e., biomass content) is calculated based on the biomass content of polyol component (B) and the formulation of polyisocyanate component (A) and polyol component (B), in accordance with the examples described later.

[0128] [Isocyanate group concentration] The urethane prepolymer preferably has a predetermined isocyanate group concentration (NCO concentration).

[0129] From the viewpoint of moldability and handling properties, the NCO concentration of the urethane prepolymer is, for example, 15% by mass or more, preferably 18% by mass or more, and more preferably 20% by mass or more. Also, from the viewpoint of moldability and handling properties, the NCO concentration of the urethane prepolymer is, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less.

[0130] In other words, from the viewpoint of moldability and handling properties, the NCO concentration of the urethane prepolymer is, for example, 15% by mass or more and 50% by mass or less, preferably 18% by mass or more and 40% by mass or less, and more preferably 20% by mass or more and 30% by mass or less.

[0131] [Viscosity] Urethane prepolymers have excellent handling properties, and their viscosity is relatively low immediately after production (for example, within one minute after the reaction is complete). Therefore, urethane prepolymers have excellent handling properties.

[0132] More specifically, the viscosity of the urethane prepolymer at 25°C immediately after manufacturing is, from the viewpoint of handling properties, for example, 1000 mPa·s or less, preferably 900 mPa·s or less, more preferably 800 mPa·s or less, even more preferably 500 mPa·s or less, and particularly preferably 200 mPa·s or more. Also, the viscosity of the urethane prepolymer at 25°C immediately after manufacturing is, from the viewpoint of moldability, for example, 10 mPa·s or more, preferably 30 mPa·s or more, more preferably 50 mPa·s or more, even more preferably 80 mPa·s or more, and particularly preferably 100 mPa·s or more.

[0133] In other words, from the viewpoint of moldability and handling properties, the viscosity of the urethane prepolymer at 25°C immediately after manufacturing is, for example, 10 mPa·s or more and 1000 mPa·s or less, preferably 30 mPa·s or more and 900 mPa·s or less, more preferably 50 mPa·s or more and 800 mPa·s or less, even more preferably 80 mPa·s or more and 500 mPa·s or less, and particularly preferably 100 mPa·s or more and 200 mPa·s or more.

[0134] The viscosity of the urethane prepolymer at 25°C is measured using an E-type viscometer, in accordance with the examples described later.

[0135] (5) Effects In the above urethane prepolymer, the polyisocyanate component (A) contains an aromatic polyisocyanate. The polyol component (B) contains a plant-derived polyol (b-1). The plant-derived polyol (b-1) has structural units derived from plant compounds, and the number-average molecular weight of the plant-derived polyol (b-1) is within a predetermined range. Furthermore, the content ratio of structural units derived from plant compounds is within a predetermined range relative to the total amount of the urethane prepolymer, and / or the content ratio of bio-derived carbon is within a predetermined range relative to the total carbon contained in the urethane prepolymer.

[0136] Therefore, the urethane prepolymer of the present invention possesses both relatively excellent moldability and relatively excellent handling properties.

[0137] As a result, the above-mentioned urethane prepolymer is suitably used as a raw material for manufacturing polyurethane foam (described later). More specifically, the above-mentioned urethane prepolymer is contained in a polyurethane resin composition which is a raw material for manufacturing polyurethane foam (described later).

[0138] 2. Polyurethane resin composition (1) Overall composition The polyurethane resin composition is a raw material for polyurethane resin (preferably polyurethane foam described later), and is an unreacted and uncured composition.

[0139] More specifically, the polyurethane resin composition contains a prepolymer component and a resin premix component. Preferably, the polyurethane resin composition consists of a prepolymer component and a resin premix component.

[0140] (2) Prepolymer component The prepolymer component contains the above-mentioned urethane prepolymer. Preferably, the prepolymer component consists of the above-mentioned urethane prepolymer.

[0141] (3) Resin premix components (3-1) Polyol component (C) The resin premix components contain polyol component (C) as an essential component.

[0142] The polyol component (C) is not particularly limited and can be any known polyol. Examples of known polyols include the plant-derived polyols and petroleum-derived polyols mentioned above.

[0143] From an environmental standpoint, the polyol component (C) is preferably a plant-derived polyol (c-1). That is, the polyol component (C) preferably contains a plant-derived polyol (c-1).

[0144] Examples of plant-derived polyols (c-1) include polyols similar to those described above as plant-derived polyol (b-1) as polyol component (B).

[0145] More specifically, examples of plant-derived polyols (c-1) include the plant-derived polyester polyols mentioned above. These can be used alone or in combination of two or more types. From the viewpoint of tensile strength, elongation, and tear strength of the polyurethane foam, plant-derived polyester polyols are preferably used as plant-derived polyols (c-1). That is, from the viewpoint of environmental friendliness, the polyol component (C) preferably contains plant-derived polyols (c-1), and more preferably contains plant-derived polyester polyols from the viewpoint of tensile strength, elongation, and tear strength.

[0146] Furthermore, the various physical properties of the plant-derived polyol (c-1) are the same as those of the plant-derived polyol (b-1) described above as polyol component (B).

[0147] Furthermore, from the viewpoint of hardness and rebound elasticity of the polyurethane foam, a petroleum-derived polyol (c-2) is preferably used as the polyol component (C). That is, from the viewpoint of hardness and rebound elasticity of the polyurethane foam, the polyol component (C) preferably further contains a petroleum-derived polyol (c-2).

[0148] Examples of petroleum-derived polyols (c-2) include polyols similar to the petroleum-derived polyol (b-2) described above as polyol component (B).

[0149] More specifically, petroleum-derived polyols (c-2) include, for example, the petroleum-derived macropolyols mentioned above, and more specifically, petroleum-derived polyether polyols, petroleum-derived polyester polyols, petroleum-derived polycarbonate polyols, petroleum-derived polyurethane polyols, epoxy polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These can be used individually or in combination of two or more types.

[0150] From the viewpoint of hardness and rebound elasticity of polyurethane foam, petroleum-derived polyols (c-2) are preferably petroleum-derived polyether polyols and vinyl monomer-modified polyols, and more preferably a combination of petroleum-derived polyether polyols and vinyl monomer-modified polyols. When petroleum-derived polyether polyols and vinyl monomer-modified polyols are used in combination, the ratio of these combinations is appropriately set according to the purpose and application.

[0151] Furthermore, the various physical properties of petroleum-derived polyol (c-2) are the same as those of petroleum-derived polyol (b-2) described above as polyol component (B).

[0152] (3-2) Content ratio of plant-derived polyols and petroleum-derived polyols In polyol component (C), the content ratio of plant-derived polyol (c-1) and petroleum-derived polyol (c-2) is not particularly limited and is set as appropriate according to the purpose and use.

[0153] More specifically, from the viewpoint of balancing the mechanical properties of polyurethane foam (described later), the content of plant-derived polyol (c-1) is, for example, 0% by mass or more and 100% by mass or less, preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 70% by mass or less, and even more preferably 30% by mass or more and 50% by mass or less, relative to the total amount of plant-derived polyol (c-1) and petroleum-derived polyol (c-2).

[0154] In other words, from the viewpoint of balancing the mechanical properties of polyurethane foam (described later), the content of petroleum-derived polyol (c-2) is, for example, 0% by mass or more and 100% by mass or less, preferably 10% by mass or more and 90% by mass or less, more preferably 30% by mass or more and 80% by mass or less, and even more preferably 50% by mass or more and 70% by mass or less, relative to the total amount of plant-derived polyol (c-1) and petroleum-derived polyol (c-2).

[0155] (3-3) Other components The resin premix components may contain other components as optional components, if necessary. These other components are components other than the polyol component (C) mentioned above. Preferably, the resin premix components contain these other components.

[0156] In other words, the resin premix component preferably contains the polyol component (C) and other components, and more preferably the resin premix component consists of the polyol component (C) and other components.

[0157] Other components include, for example, foaming agents, communicators, catalysts, and additives.

[0158] [Foaming Agents] Examples of foaming agents include water. Other examples of foaming agents include physical foaming agents. Examples of physical foaming agents include hydrocarbons, halogenated hydrocarbons, carbon dioxide, and liquefied carbon dioxide. These can be used individually or in combination of two or more.

[0159] [Communicating Agents] Examples of communicating agents include well-known communicating agents. Communicating agents are also available commercially. Communicating agents can be used alone or in combination of two or more types.

[0160] [Catalysts] Examples of catalysts include urethane catalysts. Examples of urethane catalysts include amine catalysts and metal catalysts. Examples of amine catalysts include tertiary amine catalysts, quaternary ammonium salts, and imidazoles. Examples of tertiary amine catalysts include triethylamine, triethylenediamine, bis-(2-dimethylaminoethyl) ether, and N-methylmorpholine. An example of a quaternary ammonium salt is tetraethylhydroxylammonium. Examples of imidazoles include imidazole and 2-ethyl-4-methylimidazole. Examples of metal catalysts include organotin compounds, organolead compounds, organonickel compounds, organocalt compounds, organocalt compounds, and organobismuth compounds. Examples of organotin compounds include tin acetate, tin octoate (stannous octoate), tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dimercaptide, dibutyltin maleate, dibutyltin dineodecanoate, dioctyltin dimercaptide, dioctyltin dilaurylate, and dibutyltin dichloride. Examples of organolead compounds include lead octanoate and lead naphthenate. Examples of organonicric compounds include nickel naphthenate. Examples of organocobalto compounds include cobalt naphthenate. Examples of organocupend compounds include copper octate. Examples of organobismuth compounds include bismuth octanoate (bismuth octoate) and bismuth neodecanoate. These are used individually or in combination of two or more.

[0161] Preferably, an amine-based catalyst is used as the catalyst. Amine-based catalysts have excellent handling properties because they can be mixed with a foaming agent (water). Therefore, amine-based catalysts are suitably used in the preparation of resin premix components. Furthermore, two or more types of amine-based catalysts may be used in combination.

[0162] [Additives] Examples of additives include crosslinking agents, foam stabilizers, plasticizers, fillers, antioxidants, compatibilizers, colorants, stabilizers, and UV absorbers. These may be used individually or in combination of two or more. Preferably, the additives include crosslinking agents and foam stabilizers. Examples of crosslinking agents include known low molecular weight polyols (e.g., low molecular weight polyoxyalkylene polyols) and low molecular weight polyamines (e.g., diethanolamine). Examples of foam stabilizers include silicone-based foam stabilizers, and more specifically, siloxane-polyether block copolymers.

[0163] Details regarding the proportions of other ingredients in the premix will be described later.

[0164] (3-4) Method for producing resin premix components The method for producing resin premix components is not particularly limited. For example, resin premix components can be obtained by mixing a polyol component (C) with other components in a known manner. In resin premix components, the content ratio of each component is set appropriately according to the purpose and application.

[0165] [Polyol component (C) content] From the viewpoint of the mechanical properties of polyurethane foam (described later), the polyol component (C) content is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more, relative to the total amount of resin premix components. There is no particular upper limit, but the polyol component (C) content may be, for example, 98% by mass or less, or 95% by mass or less, relative to the total amount of resin premix components.

[0166] From the viewpoint of the mechanical properties of polyurethane foam (described later), the content of polyol component (C) is, for example, 50% by mass or more and 98% by mass or less, more preferably 70% by mass or more and 98% by mass or less, and more preferably 90% by mass or more and 95% by mass or less, relative to the total amount of resin premix components.

[0167] [Foaming agent content] The blending ratio of the foaming agent is set appropriately according to the purpose and application. For example, if the foaming agent is water, the content ratio of the foaming agent (water) is, for example, 0.1 parts by mass or more and 5 parts by mass or less, preferably 0.5 parts by mass or more and 4 parts by mass or less, and more preferably 0.7 parts by mass or more and 3 parts by mass or less, per 100 parts by mass of the polyol component (C).

[0168] [Content ratio of the connecting agent] The blending ratio of the connecting agent is, for example, 0.1 parts by mass or more and 10 parts by mass or less, preferably 0.5 parts by mass or more and 5 parts by mass or less, per 100 parts by mass of the polyol component (C).

[0169] [Catalyst content ratio] The catalyst blending ratio is, for example, 0.1 parts by mass or more and 5 parts by mass or less, preferably 0.2 parts by mass or more and 3 parts by mass or less, and more preferably 0.2 parts by mass or more and 1 part by mass or less, per 100 parts by mass of polyol component (C).

[0170] [Additive Content Ratio] The blending ratio of additives is set appropriately according to the purpose and application. For example, the blending ratio of the crosslinking agent is, for example, 0.01 parts by mass or more and 2.0 parts by mass or less per 100 parts by mass of polyol component (C). Also, for example, the blending ratio of the foam stabilizer is, for example, 0.01 parts by mass or more and 2.0 parts by mass or less per 100 parts by mass of polyol component (C).

[0171] (4) Method for producing a polyurethane resin composition The method for producing a polyurethane resin composition is not particularly limited. That is, the prepolymer components are prepared by the method described above. Alternatively, for example, the premix components are prepared by the method described above. By combining these, a polyurethane resin composition can be obtained.

[0172] (5) Effects The polyurethane resin composition described above contains the urethane prepolymer described above. Therefore, the polyurethane resin composition described above possesses relatively excellent moldability and relatively excellent handling properties.

[0173] As a result, the above polyurethane resin composition is suitably used as a raw material for manufacturing polyurethane foam.

[0174] 3. Polyurethane Foam (1) Overall Composition The polyurethane foam contains the reaction product of the polyurethane resin composition described above. More specifically, it is a flexible foam obtained by reacting the polyurethane resin composition described above. That is, the polyurethane foam is a foamed polyurethane resin obtained by reacting and foaming the polyurethane resin composition described above.

[0175] (2) Method for manufacturing polyurethane foam The method for manufacturing polyurethane foam is not particularly limited. For example, first, the above-mentioned prepolymer component and the above-mentioned resin premix component are prepared as a polyurethane resin composition.

[0176] Next, the above-mentioned prepolymer component and the above-mentioned resin premix component are mixed and reacted by a known method. That is, the above-mentioned urethane prepolymer and the above-mentioned polyol component (C) are reacted and foamed in the presence of the above-mentioned other components (e.g., foaming agent, communicator, catalyst, and additive). Known methods are used as the reaction method and foaming method. For example, the slab method, the mold method, and the spray method are used, preferably the slab method and the mold method, and more preferably the mold method. The reaction conditions are set appropriately according to the purpose and application.

[0177] The mixing ratio of prepolymer components and resin premix components is adjusted, for example, based on the isocyanate index. The isocyanate index represents the ratio of isocyanate groups in the polyurethane resin composition to active hydrogen groups in the polyurethane resin composition, and is calculated, for example, based on the following formula.

[0178] Isocyanate index = [Isocyanate groups in polyurethane resin composition / Active hydrogen groups in polyurethane resin composition] × 100

[0179] More specifically, in the manufacture of polyurethane foam, the isocyanate index is, for example, 50 or more, preferably 60 or more, more preferably 70 or more, and even more preferably 80 or more. In the manufacture of polyurethane foam, the isocyanate index is, for example, 200 or less, preferably 140 or less, more preferably 120 or less, and even more preferably 100 or less. That is, in the manufacture of polyurethane foam, the isocyanate index is, for example, 50 or more and 200 or less, preferably 60 or more and 140 or less, more preferably 70 or more and 120 or less, and even more preferably 80 or more and 100 or less.

[0180] When the above-mentioned prepolymer component and the above-mentioned premix component are mixed, the above-mentioned urethane prepolymer reacts with the above-mentioned polyol component (C) in the presence of a catalyst to obtain a polyurethane resin. Furthermore, the polyurethane resin becomes foamed due to the action of a foaming agent. This results in the acquisition of polyurethane foam (foamed polyurethane resin).

[0181] (3) Physical properties of polyurethane foam [Density] The density of polyurethane foam conforming to the method described in JIS K7222 (2005) is, from the viewpoint of preventing deterioration (sagging), for example, 10 kg / m³ ３ That concludes the explanation. Furthermore, the density of the polyurethane foam should be, for example, 80 kg / m³ from the standpoint of lightweight properties. ３ The following applies:

[0182] [Hardness] (25% ILD) The hardness (25% ILD) of a 100 mm thick polyurethane foam, according to the method described in JIS K-6400-2 (1997) Method A, is, for example, 200 N / 314 cm. ２ Preferably, 210 N / 314 cm ２ In summary, for optimal comfort, 220 N / 314 cm ２ More preferably, 230 N / 314 cm ２As described above. The hardness (25ILD) of a polyurethane foam with a thickness of 100 mm measured in accordance with the method described in Method A of JIS K-6400 (1997) is, for example, 500 N / 314 cm ２ or less, preferably 400 N / 314 cm ２ or less. That is, the hardness (25ILD) of a polyurethane foam with a thickness of 100 mm measured in accordance with the method described in Method A of JIS K-6400-2 (1997) is, for example, 200 N / 314 cm ２ or more and 500 N / 314 cm ２ or less, preferably 210 N / 314 cm ２ or more and 500 N / 314 cm ２ or less, more preferably 220 N / 314 cm ２ or more and 400 N / 314 cm ２ or less, still more preferably 230 N / 314 cm ２ or more and 400 N / 314 cm ２ or less.

[0183] [Hysteresis Loss] The hysteresis loss of the polyurethane foam measured in accordance with Method B described in JIS K6400-2 (2012) is, for example, 50% or less, preferably 40% or less, more preferably 35% or less. Further, the hysteresis loss of the polyurethane foam measured in accordance with Method B described in JIS K6400-2 (2012) may be, for example, 10% or more, or 15% or more. That is, the hysteresis loss of the polyurethane foam measured in accordance with Method B described in JIS K6400-2 (2012) is, for example, 10% or more and 50% or less, preferably 10% or more and 40% or less, more preferably 15% or more and 35% or less.

[0184] [Rebound Elasticity] The rebound elasticity of polyurethane foam conforming to the method described in JIS K6400-3 (2011) is, for example, 30% or more, preferably 35% or more, and more preferably 40% or more. Alternatively, the rebound elasticity of polyurethane foam conforming to the method described in JIS K6400-3 (2011) may be, for example, 90% or less, or 85% or less. That is, the rebound elasticity of polyurethane foam conforming to the method described in JIS K6400-3 (2011) is, for example, 30% or more and 90% or less, preferably 35% or more and 90% or less, and more preferably 40% or more and 85% or less.

[0185] [Elongation] The elongation of polyurethane foam according to the method described in JIS K6400-5 (2012) is, for example, 70% or more, preferably 73% or more, and more preferably 75% or more. Alternatively, the elongation of polyurethane foam according to the method described in JIS K6400-5 (2012) may be, for example, 200% or less, or 150% or less. That is, the elongation of polyurethane foam according to the method described in JIS K6400-5 (2012) is, for example, 70% or more and 200% or less, preferably 73% or more and 150% or less, and more preferably 75% or more and 150% or less.

[0186] [Biomass Content] Polyurethane foam contains structural units derived from plant compounds. The proportion of structural units derived from plant compounds (i.e., biomass content) is adjusted from the viewpoint of environmental impact and mechanical properties.

[0187] More specifically, from the viewpoint of environmental friendliness and mechanical properties, the content of structural units derived from plant compounds (i.e., biomass content) is, for example, 5% by mass or more, preferably 8% by mass or more, and more preferably 10% by mass or more, relative to the total amount of the resin portion of the polyurethane foam (i.e., polyurethane foam excluding the pore portion). Furthermore, from the viewpoint of environmental friendliness and mechanical properties, the content of structural units derived from plant compounds (i.e., biomass content) is, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less, relative to the total amount of the resin portion of the polyurethane foam (i.e., polyurethane foam excluding the pore portion).

[0188] In other words, from the viewpoint of environmental friendliness and mechanical properties, the content of structural units derived from plant compounds (i.e., biomass content) is 5% by mass or more and 50% by mass or less, preferably 8% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 30% by mass or less, relative to the total amount of the resin portion of the polyurethane foam (i.e., polyurethane foam excluding the cellular portion).

[0189] The proportion of structural units derived from plant compounds (i.e., biomass content) is calculated based on the biomass content of the urethane prepolymer and the formulation of the prepolymer and resin premix components, in accordance with the examples described later.

[0190] (4) Effects The polyurethane foam described above is obtained using the above-mentioned urethane prepolymer and polyurethane resin composition. Therefore, the polyurethane foam described above has excellent productivity.

[0191] The polyurethane foam described above is processed into a molded product depending on the application. The method of processing the polyurethane foam is not particularly limited, and known methods can be used.

[0192] 4. Molded body (1) Overall structure The molded body contains the polyurethane foam described above. Examples of molded bodies include pressure-dispersing materials, shape-retaining materials, sound-absorbing materials, shock-absorbing materials, vibration-absorbing materials, optical materials, and cushioning materials (buffering materials), with cushioning materials being preferred.

[0193] (2) Applications The applications of the cushioning material are not particularly limited. More specifically, examples of cushioning materials include cushioning materials for vehicles, cushioning materials for furniture, and cushioning materials for bedding, with the vehicle cushioning material being preferred. In other words, the above-mentioned molded article is preferably a vehicle cushioning material. Examples of vehicles include automobiles, motorcycles, bicycles, trains, and airplanes.

[0194] In particular, the molded articles are suitably used as seat cushions in automobiles. More specifically, examples of molded articles include seat pads for seat cushions and seat pads for seat backs.

[0195] The applications of polyurethane foam and molded articles are not limited to those described above. In other words, polyurethane foam and molded articles can be suitably used in various industrial fields in addition to those described above. Such industrial fields include, for example, consumer goods, electronic materials, medical, clothing, and hygiene materials. Furthermore, applications include, for example, cleaning sponges, filters, pads, sports equipment, supporters, hydroponic mats, food cushions, seat covers, headrests, cushioning materials for nursing care, leisure sheets, wig mold-retaining agents, covers, flooring materials, cosmetic puffs, rolls, electronic components, polishing pads, sanitary products, diapers, and robot exterior materials.

[0196] (3) Effects The above molded article is obtained using the above urethane prepolymer and the above polyurethane resin composition. Therefore, the above molded article has excellent productivity.

[0197] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "parts" and "%" are based on mass. Furthermore, specific numerical values ​​such as blending ratios (content), physical properties, and parameters used in the following description may be replaced with the corresponding upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to" or "greater than") of the blending ratios (content), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above.

[0198] [1] Measurement and Evaluation Methods Various physical properties were measured and evaluated by the following methods.

[0199] [1.1] Physical properties of polyol component (B) [1.1.1] Biomass degree The biomass degree (percentage of structural units derived from plant compounds) of polyol component (B) was calculated by the following method.

[0200] In other words, the biomass content of polyol component (B) is the mass ratio (%) of structural units derived from plant compounds (preferably castor oil and castor oil fatty acids) to the total mass of polyol component (B). The mass ratio (%) of structural units derived from plant compounds to the total mass of polyol component (B) is calculated based on the raw material components and formulation of polyol component (B). For example, if polyol component (B) contains 80 parts by mass of structural units derived from plant compounds for every 100 parts by mass of polyol component (B), the biomass content of polyol component (B) is 80% (= (80 parts by mass / 100 parts by mass) × 100).

[0201] [1.1.2] The hydroxyl value of hydroxyl polyol component (B) was measured in accordance with the phthalation method of Method B of JIS K 1557-1 (2007).

[0202] [1.1.3] Average number of functional groups The average number of functional groups (average number of hydroxyl groups) of polyol component (B) was calculated using the following formula: Average number of functional groups = Moles of hydroxyl groups (amount of substance) / Moles of polyol (amount of substance)

[0203] In the above formula, the number of moles (amount of substance) of hydroxyl groups and the number of moles (amount of substance) of polyol were calculated from the raw material preparation (amount blended and number of functional groups) of polyol component (B) and the hydroxyl value mentioned above, respectively.

[0204] [1.1.4] The number-average molecular weight of polyol component (B) was calculated using the following formula: Number-average molecular weight = 56100 × Average number of functional groups / Average hydroxyl value

[0205] [1.2] Physical properties of urethane prepolymers [1.2.1] Biomass content and content of bio-derived carbon The biomass content (content of structural units derived from plant compounds) of the urethane prepolymer was calculated by the following method.

[0206] In other words, the biomass content of a urethane prepolymer is the mass ratio (%) of structural units derived from plant compounds (preferably castor oil and castor oil fatty acids) to the total mass of the urethane prepolymer. The mass ratio (%) of structural units derived from plant compounds to the total mass of the urethane prepolymer is calculated based on the raw material components and formulation of the urethane prepolymer. For example, the biomass content of a urethane prepolymer obtained by reacting 10 parts by mass of a polyol component (B) with a biomass content of 80% with 90 parts by mass of polyisocyanate with a biomass content of 0% is 8% (= 80% × 10 parts by mass / 100 parts by mass).

[0207] Furthermore, the proportion of bio-derived carbon relative to the total carbon content in the urethane prepolymer was measured in accordance with Method B of ASTM D6866-24.

[0208] [1.2.2] Isocyanate Group Concentration The theoretical value of the isocyanate group concentration of the urethane prepolymer was calculated based on the formulation. In addition, the measured value of the isocyanate group concentration of the urethane prepolymer was measured in accordance with the n-dibutylamine method of JIS K1556 (2006).

[0209] [1.2.3] Handling Properties (Viscosity Immediately After Manufacturing) The viscosity of the urethane prepolymer immediately after manufacturing at 25°C was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). The rotor number used for the measurement was No. 1. In Examples 1 to 8, Comparative Example 1 and Comparative Example 3, the rotation speed was 10 rpm. In Comparative Example 2, the rotation speed was 1 rpm. The handling properties of the urethane prepolymer were then evaluated according to the following criteria.

[0210] A: The viscosity of the urethane prepolymer (at 25°C) is 1000 mPa·s or less. B: The viscosity of the urethane prepolymer (at 25°C) exceeds 1000 mPa·s.

[0211] [1.3] Evaluation of Polyurethane Foam [1.3.1] Hardness (25% ILD) The hardness of 100 mm thick polyurethane foam was measured in accordance with Method A described in JIS K-6400 (1997).

[0212] [1.3.2] Density The density of the polyurethane foam was measured according to JIS K-7222 (2005).

[0213] [1.3.3] Hysteresis Loss The rebound elasticity of the polyurethane foam was measured according to the method described in Method B of JIS K6400-2 (2012).

[0214] [1.3.4] Rebound elasticity The rebound elasticity of the polyurethane foam was measured in accordance with the method described in JIS K6400-3 (2011).

[0215] [1.3.5] Dry set and Wet set The dry set and wet set of polyurethane foam were measured in accordance with the method described in JIS K6400.

[0216] [1.3.6] Elongation, Tensile Strength, and Tear Strength The elongation, tensile strength, and tear strength of the polyurethane foam were measured in accordance with the method described in JIS K6400-5 (2012).

[0217] [1.3.7] Moldability 1 (Cell Uniformity) The uniformity of the cells in the polyurethane foam was visually confirmed. Then, moldability was evaluated according to the following criteria.

[0218] A: Most cells were very small. Also, the size of the cells was fairly uniform. B: There were relatively few large cells. Also, the size of the cells was fairly uniform. C: There were relatively many large cells. Also, the size of the cells was not uniform.

[0219] [1.3.8] Moldability 2 (Filling) Polyurethane foam was molded in a test mold measuring 300 mm (length) x 300 mm (width) x 100 mm (height), and the filling properties of the polyurethane foam (i.e., the presence or absence of gaps) were visually checked. The moldability was then evaluated according to the following criteria.

[0220] A: No missing meat was found. B: Missing meat was found.

[0221] [1.3.9] The biomass content (percentage of structural units derived from plant compounds) of the biomass polyurethane foam was calculated using the following method.

[0222] In other words, the biomass content of polyurethane foam is the mass ratio (%) of structural units derived from plant compounds (preferably castor oil and castor oil fatty acids) to the total mass of the polyurethane foam. The mass ratio (%) of structural units derived from plant compounds to the total mass of polyurethane foam is calculated based on the raw material components and formulation of the polyurethane foam. For example, the biomass content of polyurethane foam obtained by reacting 30 parts by mass of a urethane prepolymer with a biomass content of 10% with 70 parts by mass of a polyol component (resin premix component) with a biomass content of 30% is 24% (= [10% × 30 parts by mass] + (30% × 70 parts by mass) / 100 parts by mass]).

[0223] [2] Polyisocyanate component (A) [2.1] Polyisocyanate (a-1) Nitrobenzene was hydrogenated in the presence of a catalyst to synthesize aniline. Then, aniline and formaldehyde were subjected to a condensation-rearrangement reaction in the presence of a catalyst to obtain diaminodiphenylmethane and poly(diaminodiphenylmethane). Subsequently, diaminodiphenylmethane and poly(diaminodiphenylmethane) were phosgenated, and the phosgenates were purified and separated. As a result, polyisocyanate (a-1) having the composition shown in Table 1 was obtained.

[0224]

[0225] [3] Polyol component (B) [3.1] Plant-derived polyol (b-1) The following polyester polyols (b-1-1) to (b-1-4) were prepared as plant-derived polyols (b-1-1) to be used as raw materials for the prepolymer.

[0226] [3.1.1] Polyester polyol (b-1-1) Commercial castor oil (manufactured by Ito Oil Co., Ltd., brand name Dia, castor oil polyol, hydroxyl value 154.3 mg KOH / g, average number of functional groups 2.7, number average molecular weight 982, biomass content 100%) was prepared as polyester polyol (b-1-1).

[0227] [3.1.2] Polyester polyol (b-1-2) A polyester polyol was obtained by esterifying a commercially available polyoxypropylene polyol (trade name Actcol D-400, average number of functional groups 2, hydroxyl value 280.5 mg KOH / g, manufactured by Mitsui Chemicals) with high-purity castor oil fatty acid (commercial product).

[0228] More specifically, 815.05 g of high-purity castor oil fatty acid (94% ricinoleic acid) and 232.98 g of polyoxypropylene polyol (product name Actcol D-400, average number of functional groups 2, hydroxyl value 280.5 mg KOH / g, manufactured by Mitsui Chemicals) were charged into a glass flask equipped with a thermometer, a stirrer, and a dehydrator, and these were condensed at 180°C under a nitrogen atmosphere.

[0229] When the acid value of the flask contents fell below 10 mg KOH / g, 0.21 g of tetrabutyl orthotitanate (catalyst, manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the flask. The contents of the flask were then condensed at 180°C for a total of 45 hours. The resulting reaction product (polyester polyol) was designated as polyester polyol (b-1-2). Polyester polyol (b-1-2) was an ester condensate of castor oil fatty acid to a polyoxypropylene polyol with an average functional group number of 2.

[0230] The hydroxyl value of polyester polyol (b-1-2) was 56.0 mgKOH / g, the average number of functional groups was 1.7, the number-average molecular weight was 1703, and the biomass content was 81%.

[0231] [3.1.3] Polyester polyol (b-1-3) A polyester polyol was obtained by ester condensation of a commercially available polyoxypropylene polyol (trade name SOR-400, initiator sorbitol, average number of functional groups 6, hydroxyl value 400 mg KOH / g, manufactured by Mitsui Chemicals) with castor oil fatty acid (commercial product).

[0232] More specifically, 873.0 g of castor oil fatty acid (commercially available) and 179.3 g of polyoxypropylene polyol (product name SOR-400, initiator sorbitol, average number of functional groups 6, hydroxyl value 400 mg KOH / g, manufactured by Mitsui Chemicals) were charged into a glass flask equipped with a thermometer, a stirrer, and a dehydrator, and these were condensed at 210°C under a nitrogen atmosphere.

[0233] When the acid value of the flask contents fell below 10 mg KOH / g, 0.6 g of tetrabutyl orthotitanate (catalyst, manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the flask. The contents of the flask were then condensed at 210°C for a total of 56 hours. The resulting reaction product (polyester polyol) was designated as polyester polyol (b-1-3). Polyester polyol (b-1-3) was an ester condensate of castor oil fatty acid to a polyoxypropylene polyol with an average of 6 functional groups.

[0234] The hydroxyl value of polyester polyol (b-1-3) was 52.8 mgKOH / g, the average number of functional groups was 4.4, the number-average molecular weight was 4675, and the biomass content was 87%.

[0235] [3.1.4] Polyester polyol (b-1-4) A polyester polyol was obtained by esterifying a polyester polyol (b-1-1 (i.e., commercially available castor oil)) with a commercially available castor oil fatty acid.

[0236] More specifically, 245.55 g of castor oil fatty acid (commercially available) and 767.63 g of polyester polyol (b-1-1) were charged into a glass flask equipped with a thermometer, a stirrer, and a dehydrator, and these were condensed at 180°C under a nitrogen atmosphere.

[0237] When the acid value of the flask contents fell below 10 mg KOH / g, 0.1 g of tetrabutyl orthotitanate (catalyst, manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the flask. The contents of the flask were then condensed at 180°C for a total of 40 hours. The resulting reaction product was designated as polyester polyol (b-1-4). Polyester polyol (b-1-4) was an ester condensate of castor oil fatty acids with castor oil.

[0238] The hydroxyl value of polyester polyol (b-1-4) was 115.0 mgKOH / g, the average number of functional groups was 2.7, the number-average molecular weight was 1317, and the biomass content was 100%.

[0239] [3.2] Petroleum-derived polyols (b-2) The following polyether polyol (b-2-1) was prepared as a petroleum-derived polyol to be used as a raw material for prepolymers.

[0240] [3.2.1] Polyether polyol (b-2-1) Polyether polyol (b-2-1): Random copolymer of propylene oxide and ethylene oxide, oxyethylene content: 74% by mass, oxypropylene content: 26% by mass, average number of functional groups: 3, hydroxyl value: 52 mg KOH / g, biomass content: 0%

[0241] [4] Polyol component (C) [4.1] Plant-derived polyol (c-1) The following polyester polyols (c-1-1) to (c-1-2) were prepared as plant-derived polyols (c-1-1) to be used as raw materials for resin premix components.

[0242] [4.1.1] Polyester polyol (c-1-1) As the plant-derived polyol (c-1-1), the same polyester polyol as the above-mentioned polyester polyol (b-1-4) was prepared. That is, the plant-derived polyol (c-1-1) was an ester condensate of castor oil fatty acid with castor oil.

[0243] [4.1.1] Polyester polyol (c-1-2) As the plant-derived polyol (c-1-2), the same polyester polyol as the polyester polyol (b-1-3) described above was prepared. That is, the plant-derived polyol (c-1-2) was an ester condensate of castor oil fatty acid to a polyoxypropylene polyol with an average number of 6 functional groups.

[0244] [4.2] The following polyether polyols (c-2-1) and vinyl monomer-modified polyols (c-2-2) were prepared as petroleum-derived polyols (c-2-1) to be used as raw materials for petroleum-derived polyol resin premix components.

[0245] [4.2.1] Polyether polyol (c-2-1) Polyether polyol (c-2-1): Block copolymer of propylene oxide and ethylene oxide, oxyethylene content: 15% by mass (ratio of oxyethylene units to total amount of oxyalkylene units), oxypropylene content: 85% by mass (ratio of oxypropylene units to total amount of oxyalkylene units), number average molecular weight: 7,000, average number of functional groups: 3, hydroxyl value: 24 mg KOH / g, biomass content: 0%

[0246] [4.2.2] Vinyl monomer-modified polyol (c-2-2) Vinyl monomer-modified polyol (c-2-2): A polymer polyol obtained by graft polymerization of acrylonitrile and styrene onto the following propylene oxide-ethylene oxide block copolymer (d), with a hydroxyl value of 23 mg KOH / g and a biomass content of 0%.

[0247] Propylene oxide-ethylene oxide block copolymer (d): Ratio of oxyethylene units to total oxyalkylene units (oxyethylene content): 15% by mass, Ratio of oxypropylene units to total oxyalkylene units (oxypropylene content): 85% by mass, Number average molecular weight: 5,100, Average number of functional groups: 3, Hydroxyl value: 33 mgKOH / g, Biomass content: 0%

[0248] [5] Other components The following communicators, catalysts, foaming agents, and additives were prepared as other components.

[0249] [5.1] Connecting agent Connecting agent 1: Commercial product, manufactured by Mitsui Chemicals, Inc.

[0250] [5.2] Catalyst 1: Amine catalyst, 33% by mass of triethylenediamine in a diethylene glycol solution, manufactured by Evonik.

[0251] Catalyst 2: Amine catalyst, 30% by mass of bis(dimethylaminoethyl) ether in a diethylene glycol solution, manufactured by Nippon Emulsifier Co., Ltd.

[0252] Catalyst 3: Amine catalyst, mixture of 1,4-diazabicyclo[2.2.2]octane-2-methanol and glycol, manufactured by Tosoh Corporation.

[0253] Catalyst 4: Amine catalyst, 2-((2-(2-(dimethylamino)ethoxy)ethyl)methylaminoethanol, manufactured by Tosoh Corporation.

[0254] Catalyst 5: Tin catalyst, dibutyltin dilaurate, manufactured by Nitto Chemical Co., Ltd.

[0255] [5.3] Foaming agent Foaming agent 1: Water

[0256] [5.4] Additive crosslinking agent 1: Low molecular weight polyoxyalkylene polyol, average number of functional groups: 3.5, hydroxyl value: 845 mg KOH / g, trade name: Actcol KL-210, manufactured by Mitsui Chemicals, Inc.

[0257] Crosslinking agent 2: Diethanolamine, manufactured by Mitsui Chemicals, Inc.

[0258] Foam stabilizer 1: Silicone foam stabilizer, product name: L-3601J, manufactured by Toray Dow Corning Co., Ltd.

[0259] Foam stabilizer 2: Silicone foam stabilizer, product name: TEGOSTAB B8742LF2, manufactured by Evonik.

[0260] [6] Examples 1-8 and Comparative Examples 1-3 (Urethane Prepolymers) Polyisocyanate component (A) and polyol component (B) were reacted according to the formulations shown in Table 2 to obtain urethane prepolymers.

[0261] More specifically, according to the formulation shown in Table 2, the polyisocyanate component (A) and the polyol component (B) were mixed in a container under a nitrogen atmosphere, and the mixture was heated to 80°C while stirring at 190 pm. Then, the polyisocyanate component (A) and the polyol component (B) were reacted at 80°C for 120 minutes to obtain a urethane prepolymer.

[0262] Next, the urethane prepolymer was cooled to 50°C. Furthermore, the NCO concentration of the urethane prepolymer was measured using the n-dibutylamine method in accordance with ASTM D5155-14. The results are shown in Table 2.

[0263]

[0264] Note that "n.d." in the table indicates that the measurement was not taken (No. Data).

[0265] [7] Examples 9 to 18 and Comparative Examples 4 to 7 (Polyurethane resin compositions and polyurethane foams) [7.1] Preparation of resin premix components Resin premix components were obtained by mixing polyol component (C) and other components (communicating agents, catalysts, blowing agents, and additives) according to the formulations shown in Tables 3 to 5.

[0266] More specifically, water was used as a foaming agent. In Examples 9-13, Example 15, and Comparative Examples 4-5, the proportion of water (foaming agent) was 2.8 parts by mass per 100 parts by mass of polyol component (C). In Examples 14 and 16-18, the proportion of water (foaming agent) was 3.2 parts by mass per 100 parts by mass of polyol component (C).

[0267] Furthermore, the blending ratio of the connecting agent 1 was 2.0 parts by mass per 100 parts by mass of the polyol component (C).

[0268] Furthermore, in Examples 9-13, Example 15, and Comparative Examples 4-5, catalysts 1, 2, and 5 were used as catalysts. In Examples 14 and 16-18, catalysts 3, 4, and 5 were used.

[0269] More specifically, in Examples 9-13, Example 15, and Comparative Examples 4-5, the blending ratio of catalyst 1 was 0.35 parts by mass (solids) per 100 parts by mass of polyol component (C). The blending ratio of catalyst 2 was 0.10 parts by mass (solids) per 100 parts by mass of polyol component (C). The blending ratio of catalyst 5 was 0.05 parts by mass (solids) per 100 parts by mass of polyol component (C).

[0270] Furthermore, in Examples 14 and 16-18, the blending ratio of catalyst 3 was 0.70 parts by mass (solids) per 100 parts by mass of polyol component (C). The blending ratio of catalyst 4 was 0.15 parts by mass (solids) per 100 parts by mass of polyol component (C). The blending ratio of catalyst 5 was 0.04 parts by mass (solids) per 100 parts by mass of polyol component (C).

[0271] Furthermore, foam stabilizer 1 was used as a foam stabilizer in Examples 9-13, Example 15, and Comparative Examples 4-5. Foam stabilizer 2 was used in Examples 14 and 16-18.

[0272] More specifically, in Examples 9-13, Example 15, and Comparative Examples 4-5, the blending ratio of foam stabilizer 1 was 1.0 part by mass per 100 parts by mass of polyol component (C).

[0273] Furthermore, in Examples 14 and 16-18, the blending ratio of foam stabilizer 2 was 1.0 part by mass per 100 parts by mass of polyol component (C).

[0274] Furthermore, crosslinking agent 1 was used as a foam stabilizer in Examples 9-13, Example 15, and Comparative Examples 4-5. Crosslinking agent 2 was used in Examples 14 and 16-18.

[0275] More specifically, in Examples 9-13, Example 15, and Comparative Examples 4-5, the blending ratio of crosslinking agent 1 was 1.0 part by mass per 100 parts by mass of polyol component (C).

[0276] Furthermore, in Examples 14 and 16-18, the blending ratio of crosslinking agent 2 was 0.4 parts by mass per 100 parts by mass of polyol component (C).

[0277] [6.2] Preparation of Prepolymer Components The urethane prepolymers for each example and comparative example were prepared as prepolymer components according to the formulations shown in Tables 3 to 5. In Comparative Example 4, the above polyisocyanate (a-1) was prepared instead of the urethane prepolymer.

[0278] [7.3] Polyurethane resin composition The prepolymer component and the resin premix component were combined according to the formulations shown in Tables 3 to 5. A polyurethane resin composition was then produced.

[0279] [7.4] Polyurethane Foam A mixture was obtained by mixing the prepolymer component of the polyurethane resin composition and the resin premix component according to the formulations shown in Tables 3 to 5. In Tables 3 to 5, the isocyanate index was calculated using the following formula.

[0280] Isocyanate index = [Isocyanate groups in polyurethane resin composition / Active hydrogen groups in polyurethane resin composition] × 100

[0281] Next, an aluminum test mold measuring 300 mm (length) x 300 mm (width) x 100 mm (height) was prepared. A commercially available mold release agent was then applied to the test mold, and the test mold was preheated to 65°C.

[0282] Next, a mixture of the prepolymer component and the resin premix component was injected into the test mold. The amount of the mixture injected was adjusted so that the density of the polyurethane foam, as measured according to JIS K-7222 (2005), was as shown in Tables 4 and 5.

[0283] Subsequently, the lid of the test mold was closed, the test mold was sealed using clamps, and the above mixture was allowed to foam and harden. Five minutes after injection, the clamps were removed, the molded product was demolded, and crushing (communication of air bubbles) was performed. Through these steps, polyurethane foam was manufactured.

[0284] The polyurethane foam was left for 24 hours, and then its physical properties were measured using the method described above. The results are shown in Tables 4 and 5.

[0285]

[0286]

[0287]

[0288] The above invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and should not be interpreted restrictively. Modifications of the present invention that are obvious to those skilled in the art are included in the claims described below.

[0289] The urethane prepolymer, polyurethane resin composition, polyurethane foam, and molded articles of the present invention are suitably used, for example, in the fields of household goods, electronic materials, medical equipment, clothing, and sanitary materials.

Claims

1. A urethane prepolymer containing a reaction product of a polyisocyanate component (A) and a polyol component (B), wherein the polyisocyanate component (A) contains an aromatic polyisocyanate, the polyol component (B) contains a plant-derived polyol (b-1), the plant-derived polyol (b-1) has structural units derived from a plant compound, the number-average molecular weight of the plant-derived polyol (b-1) is 1000 or more and 6000 or less, and the content ratio of the structural units derived from the plant compound is 5% by mass or more and 30% by mass or less with respect to the total amount of the urethane prepolymer.

2. The urethane prepolymer according to claim 1, wherein the polyisocyanate component (A) contains diphenylmethane diisocyanate.

3. The urethane prepolymer according to claim 1, wherein the structural units derived from the plant compound contain structural units derived from castor oil and / or castor oil fatty acids.

4. The urethane prepolymer according to claim 1, wherein the average number of functional groups of the plant-derived polyol (b-1) is 1.5 or more and 5.0 or less.

5. The urethane prepolymer according to claim 1, wherein the hydroxyl value of the plant-derived polyol (b-1) is 40 mg KOH / g or more and 150 mg KOH / g or less.

6. The urethane prepolymer according to claim 1, wherein the plant-derived polyol (b-1) contains a plant-derived polyester polyol.

7. The urethane prepolymer according to claim 1, wherein the polyol component (B) further contains a petroleum-derived polyol (b-2), and the petroleum-derived polyol (b-2) contains a petroleum-derived polyether polyol.

8. The urethane prepolymer according to claim 7, wherein the petroleum-derived polyether polyol has oxyethylene units.

9. A polyurethane resin composition comprising a prepolymer component containing a urethane prepolymer according to any one of claims 1 to 8, and a resin premix component.

10. The polyurethane resin composition according to claim 9, wherein the resin premix component contains a polyol component (C), and the polyol component (C) contains a plant-derived polyol (c-1).

11. The polyurethane resin composition according to claim 10, wherein the polyol component (C) further contains a petroleum-derived polyol (c-2).

12. A polyurethane foam containing a reaction product of the polyurethane resin composition described in claim 9.

13. The polyurethane foam according to claim 12, wherein the content of structural units derived from the plant compound is 5% by mass or more and 50% by mass or less with respect to the total amount of the resin portion of the polyurethane foam.

14. A molded article comprising the polyurethane foam described in claim 12.

15. The molded article according to claim 14, which is a cushioning material for vehicles.

16. A urethane prepolymer containing a reaction product of a polyisocyanate component (A) and a polyol component (B), wherein the polyisocyanate component (A) contains an aromatic polyisocyanate, the polyol component (B) contains a plant-derived polyol (b-1), the plant-derived polyol (b-1) has structural units derived from plant compounds, the number-average molecular weight of the plant-derived polyol (b-1) is 1000 or more and 6000 or less, and the content ratio of bio-derived carbon to the total carbon contained in the urethane prepolymer is 5% or more and 30% or less.

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