Polyester polyol, two-component curable polyurethane composition, polyurethane resin, and molded article

Abstract

To provide a polyester polyol, a two-component curable polyurethane composition, a polyurethane resin, and a molded article that can obtain a polyurethane resin having a good balance of elongation and tensile strength. [Solution] Polyester polyol is represented by the following formula (1). JPEG2026082339000009.jpg42154 (In formula (1), R1 represents a hydrocarbon group having 2 to 20 carbon atoms, R2 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, R3 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, k represents an integer of 1 or more, m represents an integer of 0 or more, n represents an integer of 0 or more, m+n represents an integer of 1 or more, and (m+n) / k is between 0.3 and 15.)

Description

Technical Field

[0001] The present invention relates to a polyester polyol, a two-component curable polyurethane composition, a polyurethane resin, and a molded article.

Background Art

[0002] Polyester polyols are widely used in various industrial fields. For example, polyester polyols are used as raw materials for polyurethane resins.

[0003] As the polyester polyol, for example, a plant-derived polyol has been proposed. More specifically, the plant-derived polyol is obtained, for example, by subjecting 1 mol of a derivative obtained by adding 6 mol of propylene oxide to 1 mol of sorbitol to ester condensation with castor oil fatty acid (see, for example, Patent Document 1 (A-3)).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the above plant-derived polyol has a hydrocarbon group derived from castor oil fatty acid at the molecular terminal. That is, the number of carbon atoms of the hydrocarbon group at the molecular terminal of the above plant-derived polyol is relatively large. Therefore, the reactivity of the hydroxyl group of the plant-derived polyol may be relatively small. As a result, the mechanical properties of the polyurethane resin obtained using the above plant-derived polyol may be relatively low.

[0006] In particular, depending on the application of the polyurethane resin, a polyurethane resin with a good balance of elongation and tensile strength is required. On the other hand, polyurethane resins obtained using the above-mentioned plant-derived polyols may not have a good balance of elongation and tensile strength.

[0007] The present invention provides a polyester polyol, a two-component curable polyurethane composition, a polyurethane resin, and a molded article that can obtain a polyurethane resin having a good balance between elongation and tensile strength. [Means for solving the problem]

[0008] The present invention [1] contains a polyester polyol represented by the following formula (1).

[0009] [ka]

[0010] (In formula (1), R1 represents a hydrocarbon group having 2 to 20 carbon atoms, R2 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, R3 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, k represents an integer of 1 or more, m represents an integer of 0 or more, n represents an integer of 0 or more, m+n represents an integer of 1 or more, and (m+n) / k is between 0.3 and 15.)

[0011] The present invention [2] includes the polyester polyol described in [1] above, wherein in formula (1), m is an integer of 1 or more and n is an integer of 1 or more.

[0012] The present invention [3] includes the polyester polyol described in [1] or [2] above, wherein in formula (1), R2 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and R3 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

[0013] The present invention [4] contains a polyester polyol according to any one of the above [1] to [3], having a number average molecular weight of 600 or more and 5000 or less.

[0014] The present invention [5] includes a polyester polyol according to any one of the above [1] to [4], which is a reaction product of a compound represented by the following formula (2) and an alkylene oxide.

[0015] [ka]

[0016] (In equation (2), R1 and k have the same meaning as R1 and k in equation (1).)

[0017] The present invention [6] contains the polyester polyol described in [5] above, wherein the total amount of the alkylene oxide is 0.1 parts by mass or more and 2.5 parts by mass or less per 1 part by mass of the compound represented by formula (2).

[0018] The present invention [7] comprises a polyester polyol according to [5] or [6] above, wherein the compound represented by formula (2) contains ricinoleic acid and / or its condensates.

[0019] The present invention [8] includes a polyester polyol according to any one of the above [5] to [7], wherein the alkylene oxide contains propylene oxide, and the proportion of the propylene oxide is 80% by mass or more with respect to the total amount of the alkylene oxide.

[0020] The present invention [9] includes a two-component curable polyurethane composition comprising a polyol component containing a polyester polyol as described in any one of the above [1] to [8] and a polyisocyanate component, wherein the equivalent ratio (NCO / OH) of isocyanate groups of the polyisocyanate component to the hydroxyl groups of the polyol component is 0.80 or more and 1.20 or less.

[0021] The present invention

[10] contains a polyurethane resin containing a reaction product of the two-component curable polyurethane composition described in [9] above.

[0022] The present invention

[11] includes a molded article containing the polyurethane resin described in

[10] above.

Effects of the Invention

[0023] The polyester polyol of the present invention has a structure represented by the above formula (1). In the above formula (1), the number of carbon atoms of the aliphatic hydrocarbon groups represented by R2 and R3 is relatively small. Also, the ratio ((m + n) / k) of the number of R1 to the numbers of R2 and R3 is within a predetermined range. Therefore, the reactivity of the hydroxyl groups at the molecular terminals of the above polyester polyol is relatively high. As a result, according to the above polyester polyol, a polyurethane resin having a good balance between elongation and tensile strength can be obtained. Further, in the above formula (1), the polyester polyol can contain a plant-derived hydrocarbon group as the hydrocarbon group represented by R1.

[0024] Also, the above two-component curable polyurethane composition contains the above polyester polyol. Therefore, according to the above two-component curable polyurethane composition, a polyurethane resin having a good balance between elongation and tensile strength can be obtained.

[0025] Also, the above polyurethane resin and the above molded article are obtained using the above polyester polyol. Therefore, the above polyurethane resin and the above molded article have a good balance between elongation and tensile strength.

Modes for Carrying Out the Invention

[0026] 8]Embodiments of the present disclosure will be described below. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the embodiments. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In this disclosure, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively. In this disclosure, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as their objectives are achieved. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced by the upper or lower limit of another numerical range described in stages. In numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced by the values ​​shown in the examples. In this disclosure, each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition in this disclosure, if there are multiple types of the substance corresponding to each component in the composition, it means the total amount of those multiple types of substances present in the composition unless otherwise specified. In this disclosure, "mass%" and "weight%" are synonymous, and "parts by mass" and "parts by weight" are synonymous. In this disclosure, the "%" indicating the amount of contained components is based on mass unless otherwise specified. In this disclosure, the term “layer” includes cases where, when observing the region in which the layer exists, it is formed not only over the entire region but also over only a portion of the region. In the notation of groups (atomic groups) in this disclosure, the notation that does not specify substitution or unsubstituted includes both those with and without substituents.

[0027] 1. Polyester polyol (1) Structure of polyester polyol Polyester polyols are represented by the following formula (1).

[0028] [ka]

[0029] (In formula (1), R1 represents a hydrocarbon group having 2 to 20 carbon atoms, R2 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, R3 represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms, k represents an integer of 1 or more, m represents an integer of 0 or more, n represents an integer of 0 or more, m+n represents an integer of 1 or more, and (m+n) / k is between 0.3 and 15.)

[0030] Formula (1) represents a divalent hydrocarbon group, more specifically, a hydrocarbon group having 2 to 20 carbon atoms.

[0031] Examples of hydrocarbon groups having 2 to 20 carbon atoms include aliphatic hydrocarbon groups having 2 to 20 carbon atoms, aromatic hydrocarbon groups having 6 to 20 carbon atoms, and aromatic aliphatic hydrocarbon groups having 7 to 20 carbon atoms.

[0032] Examples of aliphatic hydrocarbon groups having 2 to 20 carbon atoms include linear aliphatic hydrocarbon groups having 2 to 20 carbon atoms and branched aliphatic hydrocarbon groups having 3 to 20 carbon atoms.

[0033] Examples of linear aliphatic hydrocarbon groups having 2 to 20 carbon atoms include linear saturated aliphatic hydrocarbon groups having 2 to 20 carbon atoms and linear unsaturated aliphatic hydrocarbon groups having 2 to 20 carbon atoms. Examples of linear saturated aliphatic hydrocarbon groups having 2 to 20 carbon atoms include ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, 1,10-decylene, 1,12-dodecylene, 1,14-tetradecylene, 1,16-hexadecylene, 1,18-octadecylene, and 1,20-eicosanylene. Examples of linear unsaturated aliphatic hydrocarbon groups having 2 to 20 carbon atoms include vinylene, propenylene, butenyl, hexenyl, octenyl, decenyl, dodecenyl, and tetradecenyl groups.

[0034] Examples of branched aliphatic hydrocarbon groups having 3 to 20 carbon atoms include branched saturated aliphatic hydrocarbon groups and branched unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms. Examples of branched saturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms include 1,2-propylene, 1,2-butylene, 1,3-butylene, and 2-ethylhexylene. Examples of branched unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms include isopropenylene, isobutenyl, isohexenyl, isooctenyl, isodecenyl, and isododecenyl. Examples of branched unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms include ricinoleic acid residues, more specifically the -(CH2)7-C=C-CH2CH[(CH2)5CH3]- group.

[0035] Aromatic hydrocarbon groups with 6 to 20 carbon atoms include, for example, o-phenylene group, m-phenylene group, p-phenylene group, 3,5-trylene group, 2,4-trylene group, 2,6-trylene group, 1,2-naphthylene group, 1,8-naphthylene group, 2,3-naphthylene group, 4,4'-biphenylene group, and 4,4'-methylenebisphenyl group.

[0036] Examples of aromatic aliphatic hydrocarbon groups having 7 to 20 carbon atoms include o-xylylene, m-xylylene, p-xylylene, and 1,3-phenylenebis(2-propyl) groups.

[0037] In R1, the hydrocarbon group may optionally have substituents. Examples of substituents include halogen groups, cyano groups, amino groups, carboxyl groups, sulfonyl groups, and alkoxy groups. These may be used alone or in combination of two or more. The position and number of substituents are not particularly limited and are set as appropriate depending on the purpose and application. For example, in R1, the number of substituents is, for example, 3 or less, preferably 2 or less, and more preferably 1 or less. Particularly preferably, R1 has no substituents.

[0038] R1 preferably represents an aliphatic hydrocarbon group having 6 to 20 carbon atoms, more preferably an aliphatic hydrocarbon group having 10 to 20 carbon atoms, and even more preferably an aliphatic hydrocarbon group having 15 to 20 carbon atoms.

[0039] Furthermore, R1 preferably represents a branched aliphatic hydrocarbon group, and more preferably a branched unsaturated aliphatic hydrocarbon group.

[0040] In other words, R1 preferably represents a branched unsaturated aliphatic hydrocarbon group having 6 to 20 carbon atoms, more preferably a branched unsaturated aliphatic hydrocarbon group having 10 to 20 carbon atoms, even more preferably a branched unsaturated aliphatic hydrocarbon group having 15 to 20 carbon atoms, particularly preferably a ricinoleic acid residue, and more specifically a -(CH2)7-C=C-CH2CH[(CH2)5CH3]- group.

[0041] When the polyester polyol represented by formula (1) contains two or more R1s (i.e., when k, as described later, is 2 or more), each of the R1s may be the same as or different from each other. Preferably, each of the R1s is the same as each other.

[0042] In formula (1), R2 represents a divalent hydrocarbon group, more specifically, an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0043] Examples of aliphatic hydrocarbon groups having 1 to 10 carbon atoms include linear aliphatic hydrocarbon groups having 1 to 10 carbon atoms and branched aliphatic hydrocarbon groups having 3 to 10 carbon atoms.

[0044] Examples of linear aliphatic hydrocarbon groups having 1 to 10 carbon atoms include linear saturated aliphatic hydrocarbon groups having 1 to 10 carbon atoms and linear unsaturated aliphatic hydrocarbon groups having 1 to 10 carbon atoms. Examples of linear saturated aliphatic hydrocarbon groups having 1 to 10 carbon atoms include methylene, ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, 1,6-hexylene, 1,7-heptylene, 1,8-octylene, and 1,10-decylene. Examples of linear unsaturated aliphatic hydrocarbon groups having 1 to 10 carbon atoms include vinylene, propenylene, butenyl, hexenyl, octenyl, and decenyl.

[0045] Examples of branched aliphatic hydrocarbon groups having 3 to 10 carbon atoms include branched saturated aliphatic hydrocarbon groups and branched unsaturated aliphatic hydrocarbon groups having 3 to 10 carbon atoms. Examples of branched saturated aliphatic hydrocarbon groups having 3 to 10 carbon atoms include 1,2-propylene, 1,2-butylene, 1,3-butylene, and 2-ethylhexylene. Examples of branched unsaturated aliphatic hydrocarbon groups having 3 to 10 carbon atoms include isopropenyl, 1-methylallyl, and isodecenyl.

[0046] In R2, the aliphatic hydrocarbon group may optionally have the substituents described above. The position and number of substituents are not particularly limited and are set as appropriate depending on the purpose and application. For example, in R2, the number of substituents is, for example, 3 or less, preferably 2 or less, and more preferably 1 or less. Particularly preferably, R2 has no substituents.

[0047] R2 preferably represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms, more preferably an aliphatic hydrocarbon group having 2 to 4 carbon atoms, even more preferably a linear saturated aliphatic hydrocarbon group having 2 to 3 carbon atoms and / or a branched saturated aliphatic hydrocarbon group having 3 to 4 carbon atoms, even more preferably an ethylene group and / or a 1,2-propylene group, and particularly preferably a 1,2-propylene group.

[0048] When the polyester polyol represented by formula (1) contains two or more R2s (i.e., when m, as described later, is 2 or more), each of the R2s may be the same as or different from each other. Preferably, each of the R2s is the same as each other.

[0049] In formula (1), R3 represents a divalent hydrocarbon group, more specifically, an aliphatic hydrocarbon group having 1 to 10 carbon atoms.

[0050] Examples of aliphatic hydrocarbon groups having 1 to 10 carbon atoms include the linear aliphatic hydrocarbon groups having 1 to 10 carbon atoms as described above, and the branched aliphatic hydrocarbon groups having 3 to 10 carbon atoms as described above.

[0051] In R3, the aliphatic hydrocarbon group may optionally have the substituents described above. The position and number of substituents are not particularly limited and are set as appropriate depending on the purpose and application. In R3, the number of substituents is, for example, 3 or less, preferably 2 or less, and more preferably 1 or less. Particularly preferably, R3 has no substituents.

[0052] R3 preferably represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms, more preferably an aliphatic hydrocarbon group having 2 to 4 carbon atoms, even more preferably a linear saturated aliphatic hydrocarbon group having 2 to 3 carbon atoms and / or a branched saturated aliphatic hydrocarbon group having 3 to 4 carbon atoms, even more preferably an ethylene group and / or a 1,2-propylene group, and particularly preferably a 1,2-propylene group.

[0053] When the polyester polyol represented by formula (1) contains two or more R3s (i.e., when n, as described later, is 2 or more), each of the R3s may be the same as or different from each other. Preferably, each of the R3s is the same as each other.

[0054] Furthermore, in equation (1), R2 and R3 may be the same or different. Preferably, R2 and R3 are the same.

[0055] In equation (1), k represents an integer greater than or equal to 1. That is, the polyester polyol represented by equation (1) has one or more of the above R1 elements.

[0056] More specifically, k is, for example, 1 to 10, preferably 2 to 8, more preferably 2 to 5, and even more preferably 2 to 3. That is, in formula (1), the number of R1 is particularly preferably 2 to 3.

[0057] In formula (1), m represents an integer greater than or equal to 0. In other words, in formula (1), m is either 0 or an integer greater than or equal to 1. That is, the polyester polyol represented by formula (1) does not necessarily contain the above R2, or it may have one or more of the above R2. Preferably, in formula (1), m represents an integer greater than or equal to 1.

[0058] More specifically, m is, for example, 0 to 10, preferably 1 to 10, more preferably 2 to 9, even more preferably 4 to 9, and most preferably 5 to 9. That is, in formula (1), the number of R2 is particularly preferably 5 to 9.

[0059] In formula (1), n ​​represents an integer greater than or equal to 0. In other words, in formula (1), n ​​is either 0 or an integer greater than or equal to 1. That is, the polyester polyol represented by formula (1) does not necessarily contain the above R3, or it may contain one or more of the above R3. Preferably, in formula (1), n ​​represents an integer greater than or equal to 1.

[0060] More specifically, n is, for example, 0 to 10, preferably 1 to 10, more preferably 2 to 9, even more preferably 4 to 9, and most preferably 5 to 9. That is, in formula (1), the number of R3 is particularly preferably 5 to 9.

[0061] In equation (1), m+n represents an integer greater than or equal to 1. That is, in equation (1), at least one of n and m represents an integer greater than or equal to 1.

[0062] More specifically, m+n is, for example, 1 to 20, preferably 2 to 20, more preferably 4 to 20, even more preferably 8 to 20, and particularly preferably 10 to 18. That is, in equation (1), the sum of the number of R2s and R3s is particularly preferably 10 to 18.

[0063] In the polyester polyol represented by equation (1), the ratio of the number of R2s and R3s to the number of R1s (i.e., (m+n) / k) is adjusted to a predetermined range.

[0064] More specifically, in equation (1), (m+n) / k is 0.3 or more and 15 or less, preferably 1.0 or more and 13 or less, and more preferably 1.5 or more and 10 or less.

[0065] In particular, from the viewpoint of curing time, (m+n) / k is more preferably 2.0 to 10, more preferably 4.0 to 9.0, and most preferably 5.0 to 8.0. If (m+n) / k is within the above range, a polyurethane resin (described later) with relatively good mechanical properties can be obtained with a relatively short curing time. More specifically, the difference between the mechanical properties of a polyurethane resin (described later) obtained with a relatively short curing time and a polyurethane resin (described later) obtained with a relatively long curing time can be reduced.

[0066] On the other hand, from the viewpoint of obtaining a polyurethane resin (described later) having particularly excellent mechanical properties, (m+n) / k is more preferably 1.5 or more and less than 5.0, even more preferably 1.5 or more and 4.0 or less, and particularly preferably 1.5 or more and 2.0 or less. If (m+n) / k is within the above range, a polyurethane resin (described later) having particularly excellent mechanical properties can be obtained.

[0067] (2) Method for producing polyester polyol The above polyester polyols are produced, for example, by the reaction of a compound represented by the following formula (2) with an alkylene oxide. In other words, the above polyester polyols are, for example, reaction products of a compound represented by the following formula (2) with an alkylene oxide.

[0068] In other words, as will be explained in more detail later, for example, the compound shown in formula (2) below is used as an initiator, and the above polyester polyol is obtained by ring-opening addition polymerization and / or ester condensation of the compound shown in formula (2) below with an alkylene oxide.

[0069] [ka]

[0070] (In equation (2), R1 and k have the same meaning as R1 and k in equation (1).)

[0071] In formula (2), R1 has the same meaning as R1 in formula (1). That is, in formula (2), R1 represents the hydrocarbon group having 2 to 20 carbon atoms as described above.

[0072] In formula (2), R1 preferably represents an aliphatic hydrocarbon group having 6 to 20 carbon atoms, more preferably an aliphatic hydrocarbon group having 10 to 20 carbon atoms, even more preferably a branched aliphatic hydrocarbon group having 10 to 20 carbon atoms, even more preferably a branched unsaturated aliphatic hydrocarbon group having 10 to 20 carbon atoms, even more preferably a branched unsaturated aliphatic hydrocarbon group having 15 to 20 carbon atoms, particularly preferably a ricinoleic acid residue, and more specifically a -(CH2)7-C=C-CH2CH[(CH2)5CH3]- group.

[0073] In equation (2), k has the same meaning as k in equation (1). That is, in equation (2), k represents an integer of 1 or more. More specifically, k is, for example, 1 or more and 10 or less, preferably 2 or more and 8 or less, more preferably 2 or more and 5 or less, and even more preferably 2 or more and 3 or less.

[0074] More specifically, compounds represented by formula (2) include hydroxyl group-containing carboxylic acids and / or their condensates.

[0075] Hydroxyl group-containing carboxylic acids are compounds that have one hydroxyl group and one carboxyl group in one molecule. Examples of hydroxyl group-containing carboxylic acids include hydroxyl group-containing aliphatic carboxylic acids and hydroxyl group-containing aromatic carboxylic acids. Examples of hydroxyl group-containing aliphatic carboxylic acids include hydroxyacetic acid (also known as glycolic acid), α-hydroxypropionic acid (also known as lactic acid), β-hydroxypropionic acid, γ-hydroxybutyric acid, ricinoleic acid, and 12-hydroxystearic acid. Examples of hydroxyl group-containing aromatic carboxylic acids include 2-hydroxybenzoic acid (also known as salicylic acid), 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, and p-(2-hydroxyethyl)benzoic acid. These can be used individually or in combination of two or more types.

[0076] Examples of hydroxyl group-containing carboxylic acid condensates include those obtained by self-condensing the above-mentioned hydroxyl group-containing carboxylic acids using known methods. More specifically, examples of hydroxyl group-containing carboxylic acid condensates include those of the above-mentioned acid group-containing aliphatic carboxylic acids and those of the above-mentioned hydroxyl group-containing aromatic carboxylic acids. These can be used individually or in combination of two or more types.

[0077] The compounds represented by formula (2) are preferably hydroxyl group-containing aliphatic carboxylic acids and their condensates. The hydroxyl group-containing aliphatic carboxylic acids are preferably ricinoleic acid and 12-hydroxystearic acid.

[0078] Upon reduction, the compound represented by formula (2) more preferably contains at least one selected from the group consisting of ricinoleic acid, ricinoleic acid condensates, 12-hydroxystearic acid, and 12-hydroxystearic acid condensates.

[0079] In other words, ricinoleic acid is the main component of castor oil fatty acids, and 12-hydroxystearic acid is the main component of hydrogenated castor oil fatty acids. That is, ricinoleic acid and 12-hydroxystearic acid are hydroxyl-containing aliphatic carboxylic acids of plant origin. Therefore, if the compound represented by formula (2) contains at least one selected from the group consisting of ricinoleic acid, ricinoleic acid condensates, 12-hydroxystearic acid, and 12-hydroxystearic acid condensates, polyester polyols and polyurethane resins (described later) can be carbon neutral and achieve excellent environmental performance.

[0080] From the viewpoint of the mechanical properties of polyurethane resin (described later), more preferably, as the compound represented by formula (2), ricinoleic acid and its condensates are mentioned, and particularly preferably, ricinoleic acid condensates are mentioned.

[0081] The acid value of the compound represented by formula (2) is, for example, 30 mg KOH / g or more, preferably 40 mg KOH / g or more, and more preferably 50 mg KOH / g or more. Alternatively, the acid value of the compound represented by formula (2) is, for example, 150 mg KOH / g or less, preferably 100 mg KOH / g or less, and more preferably 80 mg KOH / g or less.

[0082] In other words, the acid value of the compound represented by formula (2) is, for example, 30 mg KOH / g or more and 150 mg KOH / g or less, preferably 40 mg KOH / g or more and 100 mg KOH / g or less, and more preferably 50 mg KOH / g or more and 80 mg KOH / g or less. The acid value is measured in accordance with the examples described later.

[0083] Examples of alkylene oxides include alkylene oxides having 2 to 10 carbon atoms, and preferably alkylene oxides having 2 to 4 carbon atoms. Examples of alkylene oxides having 2 to 4 carbon atoms include ethylene oxide, propylene oxide (1,2-propylene oxide), trimethylene oxide (1,3-propylene oxide), and butylene oxide. These can be used individually or in combination of two or more types.

[0084] From the viewpoint of the mechanical properties of polyurethane resin (described later), preferred alkylene oxides include ethylene oxide and propylene oxide, and more preferably propylene oxide. That is, the alkylene oxide preferably contains ethylene oxide and / or propylene oxide, and more preferably contains propylene oxide.

[0085] When alkylene oxide contains propylene oxide, the proportion of propylene oxide is not particularly limited, but is determined, for example, from the viewpoint of the mechanical properties of polyurethane resin (described later).

[0086] For example, the propylene oxide content is, for example, 1% by mass or more, preferably 20% by mass or more, more preferably 40% by mass or more, even more preferably 60% by mass or more, and particularly preferably 80% by mass or more, relative to the total amount of alkylene oxide. Also, if the alkylene oxide contains propylene oxide, the propylene oxide content is, for example, 100% by mass or less, relative to the total amount of alkylene oxide.

[0087] In other words, when the alkylene oxide contains propylene oxide, the proportion of propylene oxide is, for example, 1% by mass or more and 100% by mass or less, preferably 20% by mass or more and 100% by mass or less, more preferably 40% by mass or more and 100% by mass or less, even more preferably 60% by mass or more and 100% by mass or less, and particularly preferably 80% by mass or more and 100% by mass or less, relative to the total amount of alkylene oxide.

[0088] Furthermore, if the alkylene oxide contains propylene oxide, the alkylene oxide may also contain alkylene oxides other than propylene oxide (hereinafter referred to as "other alkylene oxides"). Preferably, the other alkylene oxide is ethylene oxide.

[0089] The content of other alkylene oxides (preferably ethylene oxide) is, for example, 0% by mass or more relative to the total amount of alkylene oxides. Furthermore, the content of other alkylene oxides (preferably ethylene oxide) is, for example, 99% by mass or less, preferably 80% by mass or less, more preferably 60% by mass or less, even more preferably 40% by mass or less, and particularly preferably 20% by mass or less, relative to the total amount of alkylene oxides.

[0090] In other words, when the alkylene oxide contains propylene oxide, the content of other alkylene oxides (preferably ethylene oxide) is, for example, 0% to 99% by mass, preferably 0% to 80% by mass, more preferably 0% to 60% by mass, even more preferably 0% to 40% by mass, and most preferably 0% to 20% by mass, relative to the total amount of alkylene oxide.

[0091] From the viewpoint of the mechanical properties of polyurethane resin (described later), the alkylene oxide is particularly preferably composed of propylene oxide. That is, the content of propylene oxide is particularly preferably 100% by mass relative to the total amount of alkylene oxide.

[0092] Furthermore, in the reaction between the compound represented by formula (2) and alkylene oxide, a composite metal cyanide catalyst (hereinafter referred to as DMC catalyst) is preferably included. That is, the compound represented by formula (2) and alkylene oxide preferably react in the presence of a DMC catalyst.

[0093] The DMC catalyst is not particularly limited, and known DMC catalysts can be used. Specific examples of DMC catalysts and methods for their production are described, for example, in the specification of International Publication No. 2013 / 157486. DMC catalysts can be used alone or in combination of two or more types.

[0094] The reaction method between the compound shown in formula (2) and the alkylene oxide is not particularly limited. For example, first, the compound shown in formula (2) and the DMC catalyst are mixed to prepare the mixture.

[0095] The proportions of the compound shown in formula (2) and the DMC catalyst are not particularly limited. For example, the proportions of the DMC catalyst are adjusted so that a polyester polyol having a desired number-average molecular weight (described later) and average number of functional groups (described later) is obtained.

[0096] More specifically, for example, the amount of DMC catalyst blended with 100 parts by mass of the total amount of the compound represented by formula (2) and the alkylene oxide is, for example, 0.001 parts by mass or more, preferably 0.005 parts by mass or more. Alternatively, the amount of DMC catalyst blended with 100 parts by mass of the total amount of the compound represented by formula (2) and the alkylene oxide is, for example, 1 part by mass or less, preferably 0.1 parts by mass or less. That is, the amount of DMC catalyst blended with 100 parts by mass of the total amount of the compound represented by formula (2) and the alkylene oxide is, for example, 0.001 parts by mass or more and 1 part by mass or less, preferably 0.005 parts by mass or more and 0.1 parts by mass or less.

[0097] Next, in this method, the above mixture is placed in a reactor, and the mixture is heated while continuously supplying alkylene oxide to it in an inert gas atmosphere (for example, a nitrogen atmosphere).

[0098] The amount of alkylene oxide supplied is adjusted within the range in which the polyester polyol represented by formula (1) above can be obtained.

[0099] More specifically, on a molar basis, for example, the total amount of alkylene oxide per mole of the compound represented by formula (2) below is, for example, 1 mole or more, preferably 5 moles or more, and more preferably 10 moles or more. Also, the total amount of alkylene oxide per mole of the compound represented by formula (2) below is, for example, 20 moles or less, preferably 18 moles or less. That is, the total amount of alkylene oxide per mole of the compound represented by formula (2) below is, for example, 1 mole or more and 20 moles or less, preferably 5 moles or more and 20 moles or less, and more preferably 10 moles or more and 18 moles or less.

[0100] Furthermore, on a mass basis, for example, the total amount of alkylene oxide per 1 part by mass of the compound represented by the following formula (2) is, for example, 0.1 parts by mass or more, preferably 0.2 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.4 parts by mass or more. Also, the total amount of alkylene oxide per 1 part by mass of the compound represented by the following formula (2) is, for example, 2.5 parts by mass or less, preferably 2.0 parts by mass or less, more preferably 1.8 parts by mass or less, and even more preferably 1.5 parts by mass or less. That is, the total amount of alkylene oxide per 1 part by mass of the compound represented by the following formula (2) is, for example, 0.1 parts by mass or more and 2.5 parts by mass or less, preferably 0.2 parts by mass or more and 2.0 parts by mass or less, more preferably 0.3 parts by mass or more and 1.8 parts by mass or less, and even more preferably 0.4 parts by mass or more and 1.5 parts by mass or less.

[0101] In the reaction method between the compound shown in formula (2) and alkylene oxide, the supply rate and supply time of the alkylene oxide are not particularly limited and can be set as appropriate.

[0102] In the reaction between the compound represented by formula (2) and an alkylene oxide, the reaction temperature is, for example, 80°C or higher, preferably 100°C or higher. Alternatively, the reaction temperature is, for example, 200°C or lower, preferably 150°C or lower. That is, the reaction temperature is, for example, 80°C or higher and 200°C or lower, preferably 100°C or higher and 150°C or lower. Also, the pressure condition (gauge pressure of the reactor) is, for example, 0.1 MPaG or higher, preferably 0.2 MPaG or higher. Also, the pressure condition (gauge pressure of the reactor) is, for example, 0.8 MPaG or lower, preferably 0.5 MPaG or lower. That is, the pressure condition (gauge pressure of the reactor) is, for example, 0.1 MPaG or higher and 0.8 MPaG or lower, preferably 0.2 MPaG or higher and 0.5 MPaG or lower.

[0103] The heating described above causes the alkylene oxide to undergo an esterification reaction with the carboxyl group of the compound represented by formula (2). Furthermore, the heating activates the DMC catalyst, allowing another alkylene oxide to undergo ring-opening polymerization at the carboxyl group side (hereinafter, one side) of the molecule.

[0104] Furthermore, the DMC catalyst is activated by the heating described above, causing the alkylene oxide to undergo ring-opening polymerization with respect to the hydroxyl group of the compound represented by formula (2). In addition, another alkylene oxide can undergo ring-opening polymerization at the molecular end on the hydroxyl group side (hereinafter referred to as the other side).

[0105] As a result, the reaction product of the compound shown in formula (2) and the alkylene oxide yields a polyester polyol shown in formula (1) (where m is an integer greater than or equal to 1 and n is an integer greater than or equal to 1).

[0106] Furthermore, in this method, the polyester polyol can be aged (matured) as needed. The aging conditions are not particularly limited and can be set as appropriate. For example, the aging temperature is, for example, 80°C or higher, preferably 100°C or higher. Alternatively, the aging temperature can be, for example, 200°C or lower, preferably 150°C or lower. That is, the aging temperature is, for example, 80°C to 200°C, preferably 100°C to 150°C. In addition, in this method, the polyester polyol can be purified by known methods as needed. For example, unreacted alkylene oxide can be removed by vacuum treatment.

[0107] The method for producing polyester polyols is not limited to the above. In other words, polyester polyols represented by formula (1) can be produced by any method appropriate to the purpose and application.

[0108] For example, in the production of polyester polyols, the compound represented by formula (2) and an alkylene oxide can be heated under the above conditions and reacted without incorporating the above-mentioned DMC catalyst.

[0109] In this method, heating causes one alkylene oxide to undergo an esterification reaction with the carboxyl group of the compound represented by formula (2). On the other hand, since no DMC catalyst is used in this method, other alkylene oxides do not undergo ring-opening polymerization at the molecular terminus on the carboxyl group side (hereinafter referred to as "one side"). Furthermore, the alkylene oxides do not undergo ring-opening polymerization with respect to the hydroxyl group of the compound represented by formula (2).

[0110] This method also yields the polyester polyol represented by equation (1) (where m is 1 and n is 0).

[0111] (3) Physical properties of polyester polyols [Hydroxyl value] The hydroxyl value of the above polyester polyol is, for example, 30 mg KOH / g or more, preferably 35 mg KOH / g or more, more preferably 40 mg KOH / g or more, and particularly preferably 50 mg KOH / g or more. Alternatively, the hydroxyl value of the above polyester polyol is, for example, 200 mg KOH / g or less, preferably 150 mg KOH / g or less, more preferably 120 mg KOH / g or less, and particularly preferably 100 mg KOH / g or less.

[0112] In other words, the hydroxyl value of the above polyester polyol is, for example, 30 mg KOH / g or less, preferably 35 mg KOH / g to 150 mg KOH / g, more preferably 40 mg KOH / g to 120 mg KOH / g, and particularly preferably 50 mg KOH / g to 100 mg KOH / g. The hydroxyl value is measured in accordance with the examples described later.

[0113] [Number average molecular weight] The number-average molecular weight of the above polyester polyol is, for example, 400 or more, preferably 600 or more, more preferably 800 or more, and particularly preferably 1000 or more. Alternatively, the number-average molecular weight of the above polyester polyol is, for example, 10000 or less, preferably 5000 or less, more preferably 3000 or less, and particularly preferably 2000 or less.

[0114] In other words, the number-average molecular weight of the above polyester polyol is, for example, 400 to 10,000, preferably 600 to 5,000, more preferably 800 to 3,000, and particularly preferably 1,000 to 2,000. The number-average molecular weight is measured as the molecular weight equivalent to standard polystyrene, according to the examples described later.

[0115] [Average number of functional groups (average number of hydroxyl groups)] The average number of functional groups (average number of hydroxyl groups) of the above polyester polyol is, for example, 1.1 or more, preferably 1.3 or more, more preferably 1.5 or more, and particularly preferably 1.7 or more. Alternatively, the average number of functional groups (average number of hydroxyl groups) of the above polyester polyol is, for example, 2.5 or less, preferably 2.3 or less, more preferably 2.0 or less, and particularly preferably 1.9 or less.

[0116] In other words, the average number of functional groups (average number of hydroxyl groups) of the above polyester polyol is, for example, 1.1 or more and 2.5 or less, preferably 1.3 or more and 2.3 or less, more preferably 1.5 or more and 2.0 or less, and particularly preferably 1.7 or more and 1.9 or less. The average number of functional groups (average number of hydroxyl groups) is measured in accordance with the examples described later.

[0117] (4) Effects The above polyester polyol has the structure shown in formula (1). In formula (1), the number of carbon atoms in the aliphatic hydrocarbon groups represented by R2 and R3 is relatively small. Also, the ratio of the number of R1s to the number of R2s and R3s ((m+n) / k) is within a predetermined range. Therefore, the reactivity of the hydroxyl groups at the molecular ends of the above polyester polyol is relatively high. As a result, the above polyester polyol yields a polyurethane resin with a good balance of elongation and tensile strength. Furthermore, the above polyester polyol can contain plant-derived hydrocarbon groups as the hydrocarbon group represented by R1 in formula (1). Therefore, the above polyester polyol can have excellent environmental properties.

[0118] The above-mentioned polyester polyol is suitably used in two-component curable polyurethane compositions, polyurethane resins, and molded articles.

[0119] 2.2 Liquid Curable Polyurethane Composition (1) Overall composition of the two-component curable polyurethane composition A two-component curable polyurethane composition is, for example, a resin composition in a two-component kit comprising a first liquid and a second liquid, which are prepared separately.

[0120] The first and second liquids are a two-component kit for forming the polyurethane resin described later. They are compounded (mixed) at the time of use and harden to produce the polyurethane resin described later.

[0121] The two-component curable polyurethane composition contains a polyol component and a polyisocyanate component. More specifically, the first component contains the polyol component and is used as the main component of the two-component curable polyurethane composition. The second component contains the polyisocyanate component and is used as the curing agent of the two-component curable polyurethane composition.

[0122] The polyol component contains the polyester polyol represented by formula (1) above as an essential component.

[0123] The polyol component may optionally contain other polyols. These other polyols are polyols other than the polyester polyols mentioned above.

[0124] Other polyols include, for example, high molecular weight polyols (excluding the polyester polyols mentioned above) and low molecular weight polyols.

[0125] High molecular weight polyols are polyols having a relatively high molecular weight. The number-average molecular weight (molecular weight equivalent to standard polystyrene as measured by GPC) of high molecular weight polyols is, for example, 400 to 20,000, preferably 500 to 10,000, and more preferably 1,000 to 5,000. Examples of high molecular weight polyols include polyether polyols, polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. These can be used individually or in combination of two or more types.

[0126] Low molecular weight polyols are polyols having a relatively low molecular weight. The number-average molecular weight of low molecular weight polyols is, for example, 40 or more and less than 400, preferably 50 or more and 300 or less. Examples of low molecular weight polyols include dihydric alcohols, trihydric alcohols, and tetrahydric or higher alcohols. Examples of dihydric alcohols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of trihydric alcohols include glycerin and trimethylolpropane. Examples of tetrahydric or higher alcohols include pentaerythritol and diglycerin. These can be used individually or in combination of two or more types.

[0127] Other polyols can be used alone or in combination of two or more. The content of other polyols is set appropriately according to the purpose and application. For example, the content of other polyols is, for example, 50% by mass or less, preferably 30% by mass or less, more preferably 10% by mass or less, and particularly preferably 0% by mass, relative to the total amount of polyol components.

[0128] In other words, the content of the polyester polyol is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass, relative to the total amount of polyol components. That is, the polyol component preferably consists of the polyester polyol described above.

[0129] The polyisocyanate component includes, for example, a polyisocyanate compound, and preferably consists of a polyisocyanate compound.

[0130] Examples of polyisocyanate compounds include those commonly used industrially. Examples of polyisocyanate compounds include linear aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and aromatic aliphatic polyisocyanates. Examples of linear aliphatic polyisocyanates include pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), and their derivatives. Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), norbornene diisocyanate (NBDI), 4,4'-methylenebis(cyclohexyl isocyanate)(hydrogenated diphenylmethane diisocyanate, H 12Examples of polyisocyanates include MDI, bis(isocyanatomethyl)cyclohexane (hydrogenated xylylene diisocyanate, H6XDI), and their derivatives. Examples of aromatic polyisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and their derivatives. Examples of aromatic aliphatic polyisocyanates include xylylene diisocyanate (XDI), tetramethyl xylylene diisocyanate (TMXDI), and their derivatives. Examples of derivatives include polymers, isocyanurate modified compounds, allophanate modified compounds, polyol modified compounds, biuret modified compounds, urea modified compounds, oxadiazinetrione modified compounds, and carbodiimide modified compounds. Furthermore, examples of aromatic polyisocyanate derivatives include polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI, and polynuclear-containing diphenylmethane diisocyanate (p-MDI)). These can be used individually or in combination of two or more types.

[0131] Preferably, the polyisocyanate compound is an aromatic polyisocyanate and its derivatives, more preferably an aromatic polyisocyanate derivative, and even more preferably polymethylene polyphenyl polyisocyanate.

[0132] In a two-component curable polyurethane composition, the first and second components are prepared separately and combined at the time of use. The ratio of the first and second components is adjusted based on the equivalent ratio (NCO / OH) of isocyanate groups (NCO) of the polyisocyanate component in the second component to the hydroxyl groups (OH) of the polyol component in the first component.

[0133] More specifically, the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate component to the hydroxyl groups of the polyol component is, for example, 0.80 or more, preferably 0.90 or more, and more preferably 1.00 or more. Alternatively, the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate component to the hydroxyl groups of the polyol component is, for example, 1.20 or less, preferably 1.15 or less, and more preferably 1.10 or less. In other words, the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate component to the hydroxyl groups of the polyol component is, for example, 0.80 or more and 1.20 or less, preferably 0.90 or more and 1.15 or less, and more preferably 1.00 or more and 1.10 or less.

[0134] The two-component curable polyurethane composition may optionally contain a known urethane catalyst. Preferably, the two-component curable polyurethane composition contains a urethane catalyst.

[0135] Examples of urethane catalysts include amine catalysts and organometallic catalysts. Examples of amine catalysts include tertiary amine catalysts, quaternary ammonium salts, and imidazoles. Examples of organometallic catalysts include organotin compounds (e.g., dibutyltin laurate, DBTDL), organolead compounds, organonickel compounds, organocalt compounds, organocalcopper compounds, and organobismuth compounds. These can be used individually or in combination of two or more.

[0136] Furthermore, the two-component curable polyurethane composition may contain known organic solvents as needed. Examples of organic solvents include ketones, nitriles, alkyl esters, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ethers, glycol ether esters, halogenated aliphatic hydrocarbons, and polar aprotons. These can be used individually or in combination of two or more.

[0137] Furthermore, the two-component curable polyurethane composition may contain known additives as needed. Examples of additives include plasticizers, anti-blocking agents, heat stabilizers, light stabilizers, antioxidants, mold release agents, pigments, dyes, lubricants, fillers, and hydrolysis inhibitors. These can be used individually or in combination of two or more types.

[0138] The timing and amount of the urethane catalyst, organic solvent, and additives are not particularly limited and can be set as appropriate according to the purpose and application. For example, the urethane catalyst, organic solvent, and additives may be contained in the first liquid, the second liquid, or both, as needed. Alternatively, the urethane catalyst, organic solvent, and additives may be prepared separately from the first and second liquids and mixed together with the first and second liquids when using the two-component curable polyurethane composition.

[0139] (2) Method for producing a two-component curable polyurethane composition The method for obtaining a two-component curable polyurethane composition is not particularly limited. For example, the first and second liquids are prepared separately. Then, a combination of the first and second liquids is prepared in the above proportions. Through this process, a two-component curable polyurethane composition is obtained.

[0140] (3) Effects The above two-component curable polyurethane composition contains the above-mentioned polyester polyol. Therefore, the above two-component curable polyurethane composition yields a polyurethane resin that has a good balance of elongation and tensile strength.

[0141] 3. Polyurethane resin The polyurethane resin contains the reaction product of the above-mentioned two-component curable polyurethane composition. Preferably, the polyurethane resin consists of the reaction product of the two-component curable polyurethane composition. The method for obtaining the polyurethane resin is not particularly limited, but for example, the two-component curable polyurethane composition is reacted by the following method.

[0142] More specifically, for example, the first liquid (polyol component) and the second liquid (polyisocyanate component) of the above-mentioned two-component curable polyurethane composition are mixed together in the above-mentioned proportions, and then reacted and cured. The reaction temperature is, for example, 10 to 250°C, preferably 20 to 200°C. The reaction time is, for example, 5 minutes to 72 hours, preferably 4 to 24 hours.

[0143] Through the above reaction, polyurethane resin (i.e., a cured resin) is obtained as a reaction product of the first liquid (polyol component) and the second liquid (polyisocyanate component).

[0144] The polyurethane resin described above is obtained using the polyester polyol described above. Therefore, the polyurethane resin has a good balance of elongation and tensile strength.

[0145] 4. Molded body The molded article contains the above-mentioned polyurethane resin. Preferably, the molded article is made of the above-mentioned polyurethane resin.

[0146] The method for obtaining the molded article is not particularly limited, and known methods can be employed. Examples of methods for obtaining the molded article include casting, thermal compression molding, injection molding, extrusion molding, and spinning. Examples of shapes for the molded article include plate-like, fibrous, strand-like, film-like, sheet-like, pipe-like, bottle-like, hollow-like, box-like, and button-like shapes.

[0147] The molded article is preferably obtained by casting. Therefore, the molded article is preferably a cast polyurethane elastomer. A cast polyurethane elastomer is an article that has a predetermined shape according to its purpose and application.

[0148] The method for obtaining the molded body by casting is not particularly limited. For example, a first liquid (polyol component) and a second liquid (polyisocyanate component) are mixed to obtain a mixture. The mixture is then degassed. The mixture is then poured into a preheated mold and cured under the above conditions. As a result, a molded body containing polyurethane resin is obtained. After demolding, the molded body is aged as necessary.

[0149] The shape of the molded body is not particularly limited and includes, for example, pellet-like, plate-like, fibrous, strand-like, film-like, sheet-like, pipe-like, hollow, and box-like shapes.

[0150] The molded article is obtained using the polyester polyol described above. Therefore, the molded article has a good balance of elongation and tensile strength. [Examples]

[0151] Next, the present invention will be described based on synthesis examples, 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.

[0152] [1] Example of preparation [1.1] Preparation Example 1 (Castor Oil Fatty Acids) Commercially available castor oil (manufactured by Ito Oil Co., Ltd., brand name Dia, polyester polyol, hydroxyl value 154.3 mg KOH / g, ricinoleic acid 89%) was hydrolyzed to obtain castor oil fatty acid (ricinoleic acid 89%).

[0153] [1.2] Preparation Example 2 (High-purity castor oil fatty acids) Molecular distillation apparatus (evaporation surface area 0.03 m²)2 Using a purifier (manufactured by Shibata Scientific Co., Ltd.), the castor oil fatty acids from Preparation Example 1 were purified. More specifically, fatty acids that do not contain hydroxyl groups (i.e., low-boiling point components) were removed from the castor oil fatty acids from Preparation Example 1. High-purity castor oil fatty acids were obtained as a result. The purification conditions were as follows.

[0154] Insertion speed: 200 g / h Evaporation surface temperature: 160°C Pressure 15 Pa Wiper rotation speed: 300 rpm

[0155] The acid value of the high-purity castor oil fatty acid was 180.7 mgKOH / g, and the hydroxyl value was 172.9 mgKOH / g. Furthermore, the ricinoleic acid content (purity) of the high-purity castor oil fatty acid was 94.0% by mass.

[0156] [1.3] Preparation Example 3 As a composite metal cyanide catalyst (DMC catalyst), we prepared PH-DMC (manufactured by Pharmicell Co., Ltd.).

[0157] [1.4] Preparation Example 4 Dibutyltin dilaurate (DBTDL) was prepared as the urethane catalyst.

[0158] [1.5] Preparation Example 5 As the polyisocyanate component, we prepared Cosmonate M-200 (manufactured by Mitsui Chemicals, a polymethylene polyphenyl isocyanate with an isocyanate group content of 31.6% by mass).

[0159] [2] Examples and Comparative Examples [2.1] Example 1 [2.1.1] Polyester polyol (A-1) 1800 g of castor oil fatty acid (89% ricinoleic acid) was charged into a glass flask equipped with a thermometer, a stirrer, and a dehydrator. The condensation reaction was carried out at 180°C under a nitrogen atmosphere to obtain ricinoleic acid condensate (P-1). The reaction was terminated when the acid value of the ricinoleic acid condensate reached 85.1 mg KOH / g. The acid value was measured in accordance with JIS K 1557-5 (2007).

[0160] Next, 500 g of ricinoleic acid condensate (P-1) and 0.50 g of PH-DMC were charged into the pressure reactor. Then, the pressure reactor was degassed and nitrogen purged by reducing the pressure, thereby removing oxygen.

[0161] Next, 792 g of propylene oxide was continuously supplied to the reactor. This caused ring-opening polymerization of propylene oxide to both the carboxyl and hydroxyl ends of the ricinoleic acid condensate (P-1). The maximum temperature during the reaction was 120°C and the maximum pressure was 0.40 MPaG.

[0162] Next, the contents of the reactor were stirred and matured while maintaining the temperature at 120°C. After that, unreacted propylene oxide was removed by reduced pressure treatment. Polyester polyol (A-1) was obtained as a result of the above procedure.

[0163] Polyester polyol (A-1) was represented by the above formula (1) and was a polyol having hydroxyl groups derived from propylene oxide at both ends. The hydroxyl value of polyester polyol (A-1) was 54.1 mgKOH / g.

[0164] [2.1.2] Two-component curable polyurethane composition (A-1) The above polyester polyol (A-1) was prepared as the polyol component (liquid 1). In addition, Cosmonate M-200 (trade name, manufactured by Mitsui Chemicals, a polymethylene polyphenyl isocyanate with an isocyanate group content of 31.6% by mass) was prepared as the polyisocyanate component (liquid 2).

[0165] Furthermore, the amounts of the polyol component and the polyisocyanate component were adjusted so that the equivalent ratio (NCO / OH) of isocyanate groups in the polyisocyanate component to the hydroxyl groups in the polyol component was as shown in Table 1.

[0166] Based on the above, a two-component curable polyurethane composition (A-1) comprising a polyol component and a polyisocyanate component was obtained.

[0167] [2.1.3] Polyurethane resin and molded articles (A-1) According to the formulations shown in Table 1, the polyol component, polyisocyanate component, and catalyst (DBTDL) were mixed for 1 minute, and the mixture was degassed under vacuum for 3 minutes. The amount of catalyst was adjusted so that the mass ratio of the catalyst to the total amount of the polyol component, polyisocyanate component, and catalyst was as shown in Table 1.

[0168] Subsequently, the above mixture was poured into a mold (2mm x 120mm x 320mm). The mixture was then cured in an oven at 80°C for 22 hours to obtain polyurethane resin and its molded product (2mm x 120mm x 320mm).

[0169] [2.2] Example 2 High-purity castor oil fatty acid (94% ricinoleic acid) was used instead of castor oil fatty acid (89% ricinoleic acid). The amount of condensation of ricinoleic acid and the amount of propylene oxide added were also changed. Except for these changes, polyester polyol (A-2) was obtained using the same method as in Example 1.

[0170] Specifically, 1800 g of high-purity castor oil fatty acid (94% ricinoleic acid) was subjected to a condensation reaction using the same method as in Example 1 to obtain a ricinoleic acid condensate (P-2). The reaction was terminated when the acid value of the contents of the flask reached 44.5 mg KOH / g.

[0171] Next, using the same method as in Example 1, 700 g of ricinoleic acid condensate (P-2) and 0.21 g of PH-DMC were charged into a pressure reactor, and 262 g of propylene oxide was continuously supplied to the reactor. This caused ring-opening polymerization of propylene oxide to both the carboxyl and hydroxyl ends of the ricinoleic acid condensate (P-2).

[0172] Next, unreacted propylene oxide was removed using the same method as in Example 1. This yielded polyester polyol (A-2).

[0173] Polyester polyol (A-2) was represented by the above formula (1) and was a polyol having hydroxyl groups derived from propylene oxide at both ends. The hydroxyl value of polyester polyol (A-2) was 56.7 mgKOH / g.

[0174] Furthermore, a two-component curable polyurethane composition, polyurethane resin, and molded article were obtained using the same method as in Example 1, except that polyester polyol (A-2) was used.

[0175] [2.3] Example 3 Propylene oxide and ethylene oxide were used in combination, and their amounts were varied. The amount of ricinoleic acid condensed was also changed. Except for these changes, polyester polyol (A-3) was obtained using the same method as in Example 1.

[0176] Specifically, 1800 g of castor oil fatty acids (89% ricinoleic acid) were subjected to a condensation reaction using the same method as in Example 1 to obtain a ricinoleic acid condensate (P-3). The reaction was terminated when the acid value of the ricinoleic acid condensate reached 71.7 mg KOH / g.

[0177] Next, using the same method as in Example 1, 600 g of ricinoleic acid condensate (P-3) and 0.60 g of PH-DMC were charged into a pressure reactor. 487 g of propylene oxide and 216 g of ethylene oxide were continuously supplied to the reactor. This resulted in ring-opening polymerization of propylene oxide and ethylene oxide at both the carboxyl and hydroxyl ends of the ricinoleic acid condensate (P-3).

[0178] Next, unreacted propylene oxide and ethylene oxide were removed using the same method as in Example 1. This yielded polyester polyol (A-3).

[0179] Polyester polyol (A-3) was represented by formula (1) above and was a polyol having hydroxyl groups derived from propylene oxide and / or ethylene oxide at both ends. The hydroxyl value of polyester polyol (A-3) was 53.5 mgKOH / g.

[0180] Furthermore, a two-component curable polyurethane composition, a polyurethane resin, and a molded article were obtained using the same method as in Example 1, except that polyester polyol (A-3) was used.

[0181] [2.4] Example 4 The amount of propylene oxide was changed. Also, PH-DMC was omitted. Furthermore, the amount of ricinoleic acid condensed and the amount of propylene oxide added were changed. Except for these changes, polyester polyol (A-4) was obtained using the same method as in Example 1.

[0182] Specifically, 4600 g of castor oil fatty acids (89% ricinoleic acid) were subjected to a condensation reaction using the same method as in Example 1 to obtain a ricinoleic acid condensate (P-4). The reaction was terminated when the acid value of the ricinoleic acid condensate reached 74.1 mg KOH / g.

[0183] Next, using the same method as in Example 1, 900 g of ricinoleic acid condensate (P-4) was charged into a pressure reactor, and 262 g of propylene oxide was continuously supplied to the reactor without charging PH-DMC. This resulted in the esterification reaction of propylene oxide to only one end of the carboxyl group side of the ricinoleic acid condensate (P-4).

[0184] Next, unreacted propylene oxide was removed using the same method as in Example 1. This yielded polyester polyol (A-4).

[0185] Polyester polyol (A-4) was represented by the above formula (1) and was a polyol having a hydroxyl group derived from propylene oxide at one end and a hydroxyl group derived from ricinoleic acid at the other end. The hydroxyl value of polyester polyol (A-4) was 104 mgKOH / g.

[0186] Furthermore, a two-component curable polyurethane composition, polyurethane resin, and molded article were obtained using the same method as in Example 1, except that polyester polyol (A-4) was used.

[0187] [2.5] Example 5 Ethylene oxide was used instead of propylene oxide, and the amount of ethylene oxide was adjusted. PH-DMC was omitted. The amount of ricinoleic acid condensed was also changed. Except for these changes, polyester polyol (A-5) was obtained using the same method as in Example 1.

[0188] Specifically, 4600 g of castor oil fatty acids (89% ricinoleic acid) were subjected to a condensation reaction using the same method as in Example 1 to obtain a ricinoleic acid condensate (P-5). The reaction was terminated when the acid value of the ricinoleic acid condensate reached 74.1 mg KOH / g.

[0189] Next, using the same method as in Example 1, 900 g of ricinoleic acid condensate (P-5) was charged into a pressure reactor, and 104.8 g of ethylene oxide was continuously supplied to the reactor without charging PH-DMC. This resulted in the esterification reaction of ethylene oxide to only one end of the carboxyl group side of the ricinoleic acid condensate (P-5).

[0190] Next, unreacted ethylene oxide was removed using the same method as in Example 1. This yielded polyester polyol (A-5).

[0191] Polyester polyol (A-5) was represented by the above formula (1) and was a polyol having a hydroxyl group derived from ethylene oxide at one end and a hydroxyl group derived from ricinoleic acid at the other end. The hydroxyl value of polyester polyol (A-5) was 108 mgKOH / g.

[0192] Furthermore, a two-component curable polyurethane composition, polyurethane resin, and molded article were obtained using the same method as in Example 1, except that polyester polyol (A-5) was used.

[0193] [2.6] Comparative Example 1 Polyester polyol (B-1) was obtained by esterifying commercially available castor oil (manufactured by Ito Oil Co., Ltd., brand name Dia, polyester polyol, hydroxyl value 154.3 mg KOH / g, 89% ricinoleic acid) with castor oil fatty acid (89% ricinoleic acid).

[0194] Specifically, 996.23 g of castor oil fatty acids (89% ricinoleic acid) and 686.02 g of castor oil (product name: Castor Oil Dia, manufactured by Ito Oil Co., Ltd.) 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.

[0195] When the acid value of the flask contents fell below 10 mg KOH / g, 0.13 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 29 hours. The resulting reaction product was designated as polyester polyol (B-1).

[0196] Polyester polyol (B-1) is a polyol having hydroxyl groups derived from ricinoleic acid at its molecular ends, and the hydroxyl value of polyester polyol (B-1) was 57.5 mgKOH / g.

[0197] Furthermore, a two-component curable polyurethane composition, a polyurethane resin, and a molded article were obtained using the same method as in Example 1, except that polyester polyol (B-1) was used.

[0198] [2.7] Comparative Example 2 A polyester polyol was obtained by esterifying commercially available diglycerin (product name Diglycerin S, manufactured by Sakamoto Pharmaceutical Co., Ltd.) with castor oil fatty acid (89% ricinoleic acid).

[0199] Specifically, 996.23 g of castor oil fatty acid (89% ricinoleic acid) and 71.25 g of diglycerin (product name Diglycerin S, manufactured by Sakamoto Pharmaceutical Co., Ltd.) were charged into a glass flask equipped with a thermometer, a stirrer, and a dehydrator, and these were condensed at 209°C under a nitrogen atmosphere.

[0200] When the acid value of the flask contents fell below 10 mg KOH / g, 0.13 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 209°C for a total of 41 hours. The resulting reaction product was designated as polyester polyol (B-2).

[0201] Polyester polyol (B-2) is a polyol having hydroxyl groups derived from ricinoleic acid at its molecular termini, and the hydroxyl value of polyester polyol (B-2) was 62.9 mgKOH / g. Furthermore, a two-component curable polyurethane composition, polyurethane resin, and molded article were obtained using the same method as in Example 1, except that polyester polyol (B-2) was used.

[0202] [2.8] Comparative Example 3 A polyester polyol was obtained by esterifying 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 (ricinoleic acid 89%).

[0203] Specifically, 872.0 g of castor oil fatty acid (89% ricinoleic acid) and 178.5 g of polyoxypropylene polyol (trade 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 211°C under a nitrogen atmosphere.

[0204] When the acid value of the contents of the flask fell below 10 mg KOH / g, 0.62 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 211°C for a total of 55 hours. The resulting reaction product was designated as polyester polyol (B-3).

[0205] Polyester polyol (B-3) is a polyol having hydroxyl groups derived from ricinoleic acid at its molecular termini, and the hydroxyl value of polyester polyol (B-3) was 52.8 mgKOH / g.

[0206] Furthermore, a two-component curable polyurethane composition, a polyurethane resin, and a molded article were obtained using the same method as in Example 1, except that polyester polyol (B-3) was used.

[0207] [2.9] Comparative Example 4 A polyester polyol was obtained by esterifying a commercially available polyoxypropylene polyol (product name SOR-400, initiator sorbitol, average number of functional groups 6, hydroxyl value 400 mg KOH / g, manufactured by Mitsui Chemicals) with another polyoxypropylene polyol (product name PE-450, initiator pentaerythritol, average number of functional groups 4, hydroxyl value 450 mg KOH / g) and high-purity castor oil fatty acid (ricinoleic acid 94%).

[0208] More specifically, 742.62 g of high-purity castor oil fatty acid (94% ricinoleic acid), 71.82 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), and 30.32 g of polyoxypropylene polyol (product name PE-450, initiator pentaerythritol, average number of functional groups 4, hydroxyl value 450 mg KOH / g) were charged into a glass flask equipped with a thermometer, a stirrer, and a dehydrator, and these were condensed at 185°C under a nitrogen atmosphere.

[0209] When the acid value of the flask contents fell below 10 mg KOH / g, 0.39 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 185°C for a total of 65 hours. The resulting reaction product was designated as polyester polyol (B-4).

[0210] Polyester polyol (B-4) is a polyol having hydroxyl groups derived from ricinoleic acid at its molecular termini, and the hydroxyl value of polyester polyol (B-4) was 47.6 mgKOH / g.

[0211] Furthermore, a two-component curable polyurethane composition, a polyurethane resin, and a molded article were obtained using the same method as in Example 1, except that polyester polyol (B-4) was used.

[0212] [2.10] Comparative Example 5 A polyester polyol was obtained by esterifying a commercially available polyoxypropylene polyol (product name Actcol D-1000, average number of functional groups 2, hydroxyl value 112.2 mg KOH / g, manufactured by Mitsui Chemicals) with castor oil fatty acid (ricinoleic acid 89%).

[0213] More specifically, 442.90 g of castor oil fatty acid (89% ricinoleic acid) and 581.22 g of polyoxypropylene polyol (product name Actcol D-1000, average number of functional groups 2, hydroxyl value 112.2 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 188°C under a nitrogen atmosphere.

[0214] When the acid value of the contents of the flask fell below 10 mg KOH / g, 0.25 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 188°C for a total of 42 hours. The resulting reaction product was designated as polyester polyol (B-5).

[0215] Polyester polyol (B-5) is a polyol having hydroxyl groups derived from ricinoleic acid at its molecular ends, and the hydroxyl value of polyester polyol (B-5) was 56.1 mgKOH / g.

[0216] Furthermore, a two-component curable polyurethane composition, polyurethane resin, and molded article were obtained using the same method as in Example 1, except that polyester polyol (B-5) was used.

[0217] [2.11] Comparative Example 6 A polyester polyol was obtained by esterifying a commercially available polyoxypropylene polyol (product 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 (ricinoleic acid 94%).

[0218] 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 182°C under a nitrogen atmosphere.

[0219] When the acid value of the flask contents fell below 10 mg KOH / g, 0.23 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 182°C for a total of 50 hours. The resulting reaction product was designated as polyester polyol (B-6).

[0220] Polyester polyol (B-6) is a polyol having hydroxyl groups derived from ricinoleic acid at its molecular termini, and the hydroxyl value of polyester polyol (B-6) was 52.0 mgKOH / g.

[0221] Furthermore, a two-component curable polyurethane composition, a polyurethane resin, and a molded article were obtained using the same method as in Example 1, except that polyester polyol (B-6) was used.

[0222] [2.12] Comparative Example 7 A commercially available polyoxypropylene polyol (product name Actcol D-2000, average number of functional groups 2, hydroxyl value 56.2 mg KOH / g, manufactured by Mitsui Chemicals) was used as the polyether polyol (B-7).

[0223] Polyether polyol (B-7) is a polyol having hydroxyl groups derived from propylene oxide at its molecular termini, and the hydroxyl value of polyether polyol (B-7) was 56.1 mgKOH / g.

[0224] Furthermore, a two-component curable polyurethane composition, polyurethane resin, and molded article were obtained using the same method as in Example 1, except that polyether polyol (B-7) was used.

[0225] [3] Structure of polyester polyol The structure of the polyester polyol in each example was confirmed by the following method. The results are shown in Table 1.

[0226] [3.1](m+n) / k For each example of polyester polyol, the value of (m+n) / k in formula (1) above was calculated by the following method.

[0227] [3.1.1] Molecular weight of ricinoleic acid condensate First, the molecular weights of the ricinoleic acid condensates (P-1) to (P-5) were calculated from the acid values ​​of the ricinoleic acid condensates (P-1) to (P-5) according to the following formula.

[0228] Molecular weight of ricinoleic acid condensate = 56100 / Acid value of ricinoleic acid condensate (mgKOH / g)

[0229] [3.1.2] Degree of condensation (k) The degree of condensation k was calculated from the molecular weight of the ricinoleic acid condensate, the molecular weight of ricinoleic acid, and the molecular weight of water released by condensation, according to the following formula. The molecular weight of ricinoleic acid was assumed to be 298, and the molecular weight of water was assumed to be 18.

[0230] Degree of condensation k = Molecular weight of ricinoleic acid condensate / (Molecular weight of ricinoleic acid - (Molecular weight of water / 2))

[0231] [3.1.3] Amount of alkylene oxide added (m+n) On the other hand, the total number of alkylene oxide molecules (m+n) that undergo ring-opening polymerization for one ricinoleic acid condensate molecule was calculated from the starting mass and molecular weight of the ricinoleic acid condensate and the starting mass and molecular weight of the alkylene oxide according to the following formula. The molecular weight of ethylene oxide was assumed to be 44.1, and the molecular weight of propylene oxide was assumed to be 58.1.

[0232] The total number of alkylene oxide molecules that undergo ring-opening polymerization for one ricinoleic acid condensate molecule (m+n) = ((Mass of alkylene oxide used / Molecular weight of alkylene oxide) / (Mass of ricinoleic acid condensate used / Molecular weight of ricinoleic acid condensate))

[0233] However, in Examples 4 and 5, since no DMC catalyst was used, the total number of alkylene oxide molecules (m+n) that undergo ring-opening polymerization for one ricinoleic acid condensate molecule was set to 1.0.

[0234] [3.1.4](m+n) / k From the above k and (m+n), (m+n) / k was calculated.

[0235] [3.2] Alkylene oxide / ricinoleic acid condensate (by mass ratio) The mass ratio of alkylene oxide to ricinoleic acid condensate (initiator) was calculated according to the following formula.

[0236] Mass of alkylene oxide added / Mass of ricinoleic acid condensate added

[0237] [3.3] Propylene oxide content (mass%) The proportion of propylene oxide in relation to the total amount of alkylene oxides (i.e., ethylene oxide and propylene oxide) was calculated according to the following formula.

[0238] Propylene oxide content (mass %) = (Mass of propylene oxide added × 100) / Total mass of alkylene oxide added

[0239] [3.4] Ethylene oxide content (mass%) The proportion of ethylene oxide to the total amount of alkylene oxides (i.e., ethylene oxide and propylene oxide) was calculated according to the following formula.

[0240] Ethylene oxide content (mass %) = (Mass of ethylene oxide charged × 100) / Total mass of alkylene oxide charged

[0241] [4] Properties of polyols The physical properties of the polyols obtained in each example and comparative example were confirmed by the following method. The results are shown in Tables 1 and 2.

[0242] [4.1] Hydroxyl value The hydroxyl value of the polyol was determined by the phthalation method in accordance with Method B of JIS K 1557-1 (2007).

[0243] [4.2] Number average molecular weight The number-average molecular weight of polyols was measured by gel permeation chromatography (GPC) under the following conditions. Under these conditions, the molecular weight equivalent to standard polystyrene with the highest frequency was used as the number-average molecular weight.

[0244] THF solvent measuring device Analytical instrument: HLC-8320GPC (Tosoh Corporation) Analysis software: EcoSEC-WS (Tosoh Corporation) Column: TSKgel guardcolumn HXL-L + TSKgel G3000HXL + TSKgel G2000HXL + TSKgel G1000HXL (Tosoh Corporation) Solvent: THF (Tetrahydrofuran, Special Grade, Junsei Chemical Co., Ltd.) Flow rate: 0.8ml / min Standard material: Polystyrene (TSKgel standard polystyrene, Tosoh Corporation) Measurement temperature: 40℃

[0245] [4.3] Average number of functional groups The average number of functional groups (average number of hydroxyl groups) of polyols was calculated using the following formula.

[0246] Average number of functional groups (average number of hydroxyl groups) = number-average molecular weight × hydroxyl value / (56.1 × 1000)

[0247] [5] Physical properties of polyurethane resin The polyurethane resins obtained in each example and comparative example were examined using the following method. The results are shown in Tables 1 and 2.

[0248] [5.1] Tensile elongation (U), tensile strength (W), and modulus of elasticity (V) Stress / strain curves were obtained for polyurethane resin using tensile tests in accordance with ISO 527. Tensile elongation (U), tensile strength (W), and modulus of elasticity (V) were then calculated from the maximum stress, maximum elongation, and modulus of elasticity observed in the tensile tests. A JIS No. 3 dumbbell test specimen was used.

[0249] [5.2] Tear strength (X) A 2mm thick sheet of polyurethane resin was used. The tear strength of the polyurethane resin was measured according to JIS K 7312 (1996). Angle-shaped test specimens were used.

[0250] [5.3] Rebound elasticity (Y) The rebound elasticity of the polyurethane resin was measured according to the method described in JIS K6255 (2013).

[0251] [5.4] Hardness (Z) The hardness of the polyurethane resin was measured according to the method described in JIS K6253-3 (2013). A Type A durometer was used.

[0252] [5.5] Balance between tensile elongation (U) and modulus of elasticity (V) Polyurethane resins require high tensile elongation (U) and high modulus of elasticity (V). Therefore, the following formula was created as an index to show the balance between these two properties.

[0253] Balance Index 1 [%·MPa] = Tensile Elongation (%) × Modulus of Elasticity (MPa)

[0254] The balance between the tensile elongation (U) and elastic modulus (V) of the polyurethane resin was then evaluated using the above formula. Specifically, a larger value for balance index 1 was considered to indicate better mechanical properties.

[0255] [5.6] Balance of tensile elongation (U), modulus of elasticity (V), tensile strength (W), tear strength (X), rebound elasticity (Y), and hardness (Z) Polyurethane resins are required to have high tensile elongation (U), high modulus of elasticity (V), high tensile strength (W), high tear strength (X), high rebound elasticity (Y), and high hardness (Z). Therefore, the following formula was created as an index to show the balance of these properties.

[0256] Balance Index 2 [%·MPa] = Tensile Elongation (%) × Elastic Modulus (MPa) × Tensile Strength (MPa) × Tear Strength (N / mm) × Rebound Elasticity (%) × Hardness (-)

[0257] Then, the balance of tensile elongation (U), elastic modulus (V), tensile strength (W), tear strength (X), rebound elasticity (Y), and hardness (Z) of the polyurethane resin was evaluated using the above formula. Specifically, a larger value for balance index 2 was considered to indicate better mechanical properties.

[0258] [5.7] Rate of change A polyurethane resin was obtained in the same manner as in each example and comparative example, except that a mixture of polyisocyanate, polyol, and catalyst was cured in an oven at 80°C for 4 hours. The obtained polyurethane resin is referred to as a short-curing polyurethane resin.

[0259] Furthermore, the polyurethane resin obtained in each example and comparative example (curing time: 22 hours) is referred to as the long-curing polyurethane resin.

[0260] Next, the mechanical properties of the short-curing polyurethane resin (specifically, the tensile elongation (U), elastic modulus (V), tensile strength (W), tear strength (X), rebound elasticity (Y), and hardness (Z)) were measured using the methods described above.

[0261] Next, the change rate of the mechanical properties of the long-time curing polyurethane resin with respect to the mechanical properties of the short-time curing polyurethane resin was calculated based on the following formula. In the following formula, the smaller the change rate, the more it indicates that a polyurethane resin having relatively excellent mechanical properties can be obtained in a relatively short curing time.

[0262] Change rate of tensile elongation (U) [-] = Tensile elongation (%) of long-time curing polyurethane resin / Tensile elongation (%) of short-time curing polyurethane resin

[0263] Change rate of elastic modulus (V) [-] = Elastic modulus (MPa) of long-time curing polyurethane resin / Elastic modulus (MPa) of short-time curing polyurethane resin

[0264] Change rate of tensile strength (W) [-] = Tensile strength (MPa) of long-time curing polyurethane resin / Tensile strength (MPa) of short-time curing polyurethane resin

[0265] Change rate of tear strength (X) [-] = Tear strength (N / mm) of long-time curing polyurethane resin / Tear strength (N / mm) of short-time curing polyurethane resin

[0266] Change rate of resilience (Y) [-] = Resilience (%) of long-time curing polyurethane resin / Resilience (%) of short-time curing polyurethane resin

[0267] Change rate of hardness (Z) [-] = Hardness (-) of long-time curing polyurethane resin / Hardness (-) of short-time curing polyurethane resin

[0268] [4.8] Standard deviation Regarding the change rates of the above six mechanical properties (specifically, the above tensile elongation (U), elastic modulus (V), tensile strength (W), tear strength (X), resilience (Y) and hardness (Z)), the standard deviation of the change rates was calculated using the STDEV.P function of Microsoft's spreadsheet software Excel (registered trademark). The smaller the standard deviation of the change rate, the more it indicates that a polyurethane resin having relatively excellent mechanical properties can be obtained in a relatively short curing time.

[0269] [Table 1]

[0270] [Table 2]

[0271] Details of the abbreviations in the table are as follows. M-200: Product name Cosmonate M-200, manufactured by Mitsui Chemicals, isocyanate group content 31.6% by mass, polymethylene polyphenyl isocyanate.

Claims

1. A polyester polyol represented by the following formula (1). 【Chemistry 1】 (In equation (1), R １ This refers to a hydrocarbon group with 2 to 20 carbon atoms. R ２ This represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms. R ３ This represents an aliphatic hydrocarbon group having 1 to 10 carbon atoms. k represents an integer greater than or equal to 1. m represents a non-negative integer, n represents a non-negative integer, m+n represents an integer greater than or equal to 1. (m+n) / k is between 0.3 and 15.

2. The polyester polyol according to claim 1, wherein in formula (1), m represents an integer of 1 or more, and n represents an integer of 1 or more.

3. In equation (1), R ２ However, it exhibits an aliphatic hydrocarbon group with 1 to 4 carbon atoms, R ３ The polyester polyol according to claim 1 or 2, wherein it exhibits an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

4. A polyester polyol according to claim 1 or 2, wherein the number average molecular weight is 600 or more and 5000 or less.

5. The compound represented by the following formula (2), Alkylene oxide and A polyester polyol according to claim 1 or 2, which is a reaction product of the above. 【Chemistry 2】 (In equation (2), R １ and k are R in equation (1) １ (And k have the same meaning.)

6. The polyester polyol according to claim 5, wherein the total amount of the alkylene oxide is 0.1 parts by mass or more and 2.5 parts by mass or less per 1 part by mass of the compound represented by formula (2).

7. The polyester polyol according to claim 5, wherein the compound represented by formula (2) contains ricinoleic acid and / or its condensate.

8. The alkylene oxide contains propylene oxide, The polyester polyol according to claim 5, wherein the content of the propylene oxide is 80% by mass or more relative to the total amount of the alkylene oxide.

9. A polyol component containing the polyester polyol described in claim 1 or 2, Polyisocyanate components and It contains, The equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate component to the hydroxyl groups of the polyol component is 0.80 or more and 1.20 or less. A two-component curable polyurethane composition.

10. A polyurethane resin containing the reaction product of the two-component curable polyurethane composition described in claim 9.

11. A molded article comprising the polyurethane resin described in claim 10.

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