Polyurethane and method for producing polyurethane

Abstract

To provide a novel polyurethane.SOLUTION: A polyurethane has at least one selected from the group consisting of a structure represented by formula (A) and a structure represented by formula (B) (wherein, in the formula, R1 represents a hydrocarbon group having 1 or more and 12 or less carbon atoms, which may have a substituent, or a single bond; and a plurality of R1 may be identical to or different from each other).SELECTED DRAWING: None

Description

[Technical Field]

[0001] TECHNICAL FIELD The present disclosure relates to polyurethanes and methods for making polyurethanes. [Background technology]

[0002] Polyurethane is widely used in a variety of plastic products, paints, adhesives, etc., due to its excellent heat resistance and mechanical strength. BACKGROUND ART Conventionally, a technique for imparting desired physical properties such as hardness and elastic modulus to polyurethane by adjusting the content of hard segments is widely known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-191275 Summary of the Invention [Problem to be solved by the invention]

[0004] However, simply adjusting the content of existing hard segments limits the properties that can be imparted to polyurethanes, and thus, polyurethanes with new structures are needed to increase the freedom of material selection. An object of the present disclosure is to provide a novel polyurethane. [Means for solving the problem]

[0005] As a result of extensive research, the inventors of the present disclosure have solved the above problems by introducing a bifuran skeleton into polyurethane, thereby completing the present invention.

[0006] [1] A polyurethane having at least one structure selected from the group consisting of a structure represented by formula (A) and a structure represented by formula (B). [ka] (In the formula, R 1 represents a hydrocarbon group having from 1 to 12 carbon atoms which may have a substituent, or a single bond; Multiple R 1 may be the same or different from each other.) [2] The polyurethane according to [1], having a structural unit represented by formula (A1): [ka] (In the formula, R 1 is R in formula (A). 1 is synonymous with; R 2 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent. [3] The polyurethane according to [2], further having a constitutional unit represented by formula (A2): [ka] (In the formula, R 2 is R in formula (A1). 2 is synonymous with; R 3 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R a1 (OR a1 ) n1 -*, *-R a2 (Si(R a3 )2O) n2 Si(R a3 )2R a2 -*, *-((CH2) x OCOR a4 COO) n3 (CH2) x A group represented by -*, or *-((C(R a6 )2) z COO)n4 R a5 (OCO(C(R a6 )2) z ) n4 - represents a group represented by *; R a1 represents an alkylene group having 1 to 6 carbon atoms; R a2 represents an alkylene group having 1 to 10 carbon atoms in which -CH2- may be replaced by -O- or a single bond; R a3 represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R a4 is a phenylene group or -(CH2) y - represents a group represented by *; R a5 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent; R a6 represents a hydrogen atom or a methyl group; Multiple R a1 may be the same or different from each other; Multiple R a2 may be the same or different from each other; Multiple R a3 may be the same or different from each other; Multiple R a4 may be the same or different from each other; Multiple R a6 may be the same or different from each other; n1 represents an integer between 1 and 100; n2 represents an integer between 1 and 100; n3 represents an integer equal to or greater than 2; n4 represents an integer between 1 and 1,000; Multiple n4's may be the same or different from each other; x represents an integer equal to or greater than 1; y represents an integer equal to or greater than 0; z represents an integer of 1 or greater; Multiple x's may be the same or different from each other; Multiple y's may be the same or different from each other; Multiple z's may be the same or different. [4] The polyurethane according to any one of [1] to [3], which has a structural unit represented by formula (B1). [ka] (In the formula, R 4 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R b1 (OR b1 ) m1 -*, *-R b2 (Si(R b3 )2O) m2 Si(R b3 )2R b2 -*, *-((CH2) p OCOR b4 COO) m3 (CH2) p A group represented by -*, or *-((C(R b6 )2) r COO) m4 R b5 (OCO(C(R b6 )2) r ) m4 - represents a group represented by *; R b1 represents an alkylene group having 1 to 6 carbon atoms; R b2 represents an alkylene group having 1 to 10 carbon atoms in which -CH2- may be replaced by -O- or a single bond; R b3 represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R b4 is a phenylene group or -(CH2) q - represents a group represented by *; R b5 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent; R b6 represents a hydrogen atom or a methyl group; Multiple R b1 may be the same or different from each other; Multiple R b2 may be the same or different from each other; Multiple R b3 may be the same or different from each other; Multiple R b4 may be the same or different from each other; Multiple R b6 may be the same or different from each other; m1 represents an integer of 1 or more and 100 or less; m2 represents an integer between 1 and 100; m3 represents an integer equal to or greater than 2; m4 represents an integer between 1 and 1,000; Multiple m4 may be the same or different from each other; p represents an integer of 1 or greater; q represents an integer equal to or greater than 0; r represents an integer equal to or greater than 1; Multiple p's may be the same or different from each other; Multiple q's may be the same or different from each other; Multiple r's may be the same or different. [5] The polyurethane according to [4], further having a constitutional unit represented by formula (B2): [ka] (In the formula, R 4 is R in formula (B1) 4 is synonymous with; R 5 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent. [6] A plastic molded product comprising the polyurethane according to any one of [1] to [5]. [7] The plastic molded product according to [6], which is a fiber, a film, or a foam. [8] A polyurethane composition comprising the polyurethane according to any one of [1] to [5]. [9] The polyurethane composition according to [8], which is used for a paint, an adhesive, a pressure-sensitive adhesive, or an ink.

[10] A method for producing polyurethane, comprising a reaction step of reacting a diol with a diisocyanate, wherein one or both of the following X1 and X2 are satisfied: X1: The diol includes a diol represented by formula (a1). X2: The diisocyanate includes a diisocyanate represented by formula (b2). [ka] (In the formula, R 1 represents a hydrocarbon group having from 1 to 12 carbon atoms which may have a substituent, or a single bond; Multiple R 1 may be the same or different from each other.)

[11] Meet X1, The method for producing a polyurethane according to

[10] , wherein the diisocyanate includes a diisocyanate represented by formula (a2). [ka] (In the formula, R 2 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent.

[12] The method for producing a polyurethane according to

[11] , wherein the diol further includes a diol represented by formula (a3): [ka] (In the formula, R 3 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R a1 (ORa1 ) n1 -*, *-R a2 (Si(R a3 )2O) n2 Si(R a3 )2R a2 -*, *-((CH2) x OCOR a4 COO) n3 (CH2) x A group represented by -*, or *-((C(R a6 )2) z COO) n4 R a5 (OCO(C(R a6 )2) z ) n4 - represents a group represented by *; R a1 represents an alkylene group having 1 to 6 carbon atoms; R a2 represents an alkylene group having 1 to 10 carbon atoms in which -CH2- may be replaced by -O- or a single bond; R a3 represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R a4 is a phenylene group or -(CH2) y - represents a group represented by *; R a5 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent; R a6 represents a hydrogen atom or a methyl group; Multiple R a1 may be the same or different from each other; Multiple R a2 may be the same or different from each other; Multiple R a3 may be the same or different from each other; Multiple R a4 may be the same or different from each other; Multiple R a6 may be the same or different from each other; n1 represents an integer between 1 and 100; n2 represents an integer between 1 and 100; n3 represents an integer equal to or greater than 2; n4 represents an integer between 1 and 1,000; Multiple n4's may be the same or different from each other; x represents an integer equal to or greater than 1; y represents an integer equal to or greater than 0; z represents an integer of 1 or greater; Multiple x's may be the same or different from each other; Multiple y's may be the same or different from each other; Multiple z's may be the same or different.

[13] Meet X2, The method for producing a polyurethane according to any one of

[10] to

[12] , wherein the diol includes a diol represented by formula (b1). [ka] (In the formula, R 4 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R b1 (OR b1 ) m1 -*, *-R b2 (Si(R b3 )2O) m2 Si(R b3 )2R b2 -*, *-((CH2) p OCOR b4 COO) m3 (CH2) p A group represented by -*, or *-((C(R b6 )2) r COO) m4 R b5 (OCO(C(R b6 )2) r ) m4 - represents a group represented by *; R b1 represents an alkylene group having 1 to 6 carbon atoms; R b2represents an alkylene group having 1 to 10 carbon atoms in which -CH2- may be replaced by -O- or a single bond; R b3 represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R b4 is a phenylene group or -(CH2) q - represents a group represented by *; R b5 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent; R b6 represents a hydrogen atom or a methyl group; Multiple R b1 may be the same or different from each other; Multiple R b2 may be the same or different from each other; Multiple R b3 may be the same or different from each other; Multiple R b4 may be the same or different from each other; Multiple R b6 may be the same or different from each other; m1 represents an integer of 1 or more and 100 or less; m2 represents an integer between 1 and 100; m3 represents an integer equal to or greater than 2; m4 represents an integer between 1 and 1,000; Multiple m4 may be the same or different from each other; p represents an integer of 1 or greater; q represents an integer equal to or greater than 0; r represents an integer equal to or greater than 1; Multiple p's may be the same or different from each other; Multiple q's may be the same or different from each other; Multiple r's may be the same or different.

[14] The method for producing a polyurethane according to

[13] , wherein the diisocyanate further includes a diisocyanate represented by formula (b3): [ka] (In the formula, R 5 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent.

[15] an azidation step of azidating a dicarboxylic acid represented by formula (b2-1) to obtain a diacyl azide represented by formula (b2-2); a Curtius rearrangement step of performing a Curtius rearrangement of the acyl azide represented by formula (b2-2) to obtain a diisocyanate represented by formula (b2); A method for producing a diisocyanate having a bifuran skeleton, comprising: [ka] [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a novel polyurethane, more specifically, a novel polyurethane having a bifuran skeleton. [Brief explanation of the drawings]

[0008] [Figure 1] 1 shows the results of measuring storage modulus obtained in Examples and Comparative Examples. [Figure 2] 1 shows the measurement results of the loss tangent of the storage modulus obtained in Examples and Comparative Examples. [Figure 3] 1 is a 1H NMR spectrum of the polyurethane obtained in the example. [Figure 4] 1H NMR spectrum of the polyurethane obtained in the comparative example. [Figure 5] 1 is a 1H NMR spectrum of the polyurethane obtained in the example. [Figure 6] 1 shows the results of measuring the storage modulus and loss tangent of polyurethanes obtained in Examples and Comparative Examples. [Figure 7] FIG. 1 is a diagram showing the state change of polyurethanes obtained in Examples and Comparative Examples due to temperature increase (photographs used as drawing substitutes). [Figure 8] 1 shows the results of measuring the storage modulus of the polyurethane obtained in the examples. [Figure 9] 1 shows the measurement results of loss tangent of polyurethane obtained in the examples. [Figure 10] 1 is a differential scanning calorimetry (DSC) curve of the polyurethane obtained in the example. [Figure 11] 1 shows thermogravimetric analysis (TGA) curves of polyurethanes obtained in Examples and Comparative Examples. [Figure 12] 1 shows differential scanning calorimetry (DSC) curves of polyurethanes obtained in Examples and Comparative Examples. [Figure 13] 1 shows the results of measuring the storage modulus of polyurethanes obtained in Examples and Comparative Examples. [Figure 14] 1 shows the measurement results of loss tangents of polyurethanes obtained in Examples and Comparative Examples. [Figure 15] FIG. 1 is a diagram showing the state change of polyurethanes obtained in Examples and Comparative Examples due to temperature increase (photographs used as drawing substitutes). DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents, and can be implemented in various modifications within the scope of its gist.

[0010] In the present disclosure, the range "X to Y" means "X or more and Y or less." Furthermore, when a numerical range expressed as "X to Y" or "X or more and Y or less" is stated in stages (for example, in order of preference), the upper and lower limits of each numerical range can be combined in any way.

[0011] In the present disclosure, a description such as "X such as x1, x2, and x3" lists x1, x2, and x3 as examples of X, and does not mean that X is limited to x1, x2, x3, and the like.

[0012] 1. Polyurethane The polyurethane according to an embodiment of the present disclosure is a polyurethane having a bifuran skeleton, and has one or more structures selected from the group consisting of a structure represented by formula (A) and a structure represented by formula (B). The polyurethane according to the present embodiment preferably contains only one of the structure represented by formula (A) and the structure represented by formula (B).

[0013] [ka]

[0014] R 1 represents a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a single bond. 1 may be the same or different from each other, but are preferably the same.

[0015] In the present disclosure, the hydrocarbon may be either an aliphatic hydrocarbon or an aromatic hydrocarbon. The aliphatic hydrocarbon is not limited to a linear hydrocarbon, but may have a branched structure, a carbon-carbon unsaturated bond, or a cyclic structure. The aromatic hydrocarbon may be a monocyclic, polycyclic, or fused ring system, or may be a heterocyclic aromatic hydrocarbon. In the present disclosure, the number of carbon atoms in the hydrocarbon group does not include the number of carbon atoms in the substituent.

[0016] In addition, in the present disclosure, when it is said that a group contained in a polyurethane or a monomer that is a raw material for the polyurethane "may have a substituent," the substituent is a group that may have a substituent. The substituent can be appropriately selected depending on the type of benzene. The position and number of the substituent to be bonded are not particularly limited. Specific examples of the substituent include deuterium atoms; alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, and tert-butyl; cycloalkyl groups having 3 to 6 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; aromatic hydrocarbon groups having 6 to 10 carbon atoms, such as phenyl, 1-naphthyl, and 2-naphthyl; alkoxy groups having 1 to 4 carbon atoms, such as methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butoxy, sec-butoxy, isobutoxy, and tert-butoxy; inert silyl groups, such as trimethylsilyl, triethylsilyl, and triphenylsilyl; and halogeno groups, such as fluoro, chloro, and bromo.

[0017] R 1 The hydrocarbon group represented by the formula (I) preferably has 1 or more and 8 or less carbon atoms, more preferably 1 or more and 6 or less carbon atoms, even more preferably 1 or more and 4 or less carbon atoms, and even more preferably 1 or 2 carbon atoms.

[0018] R 1 Specific examples of the hydrocarbon group having 1 to 12 carbon atoms represented by the formula (I) include alkylene groups such as methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, and decamethylene; cycloalkylene groups such as cyclohexanediyl and adamantanediyl; arylene groups such as phenylene, biphenyldiyl, and naphthalenediyl; and alkylenearylenealkylene groups such as xylylene.

[0019] In formula (A), R 1is preferably an alkylene group having 1 to 12 carbon atoms which may have a substituent or a single bond, more preferably an alkylene group having 1 to 6 carbon atoms which may have a substituent or a single bond, and even more preferably an alkylene group having 1 to 4 carbon atoms which may have a substituent or a single bond. is.

[0020] The bifuran skeleton in formula (A) and formula (B) is a skeleton in which two furan rings are directly linked by a carbon-carbon bond, and its most stable structure has a dihedral angle of 180°, high planarity, and high rigidity. Furthermore, since the bifuran skeleton not only has a highly planar most stable structure but also has extended π-conjugation, it is thought to self-assemble in polyurethane and exhibit a function similar to that of a hard segment. Due to the introduction of the bifuran skeleton, the polyurethane according to this embodiment can exhibit thermal properties and / or mechanical properties different from those of conventional polyurethanes.

[0021] A suitable embodiment of the polyurethane having the structure represented by formula (A) is a polyurethane having a structural unit represented by formula (A1). The structural unit represented by formula (A1) is, for example, a structural unit formed by the reaction of a diol represented by formula (a1) with a diisocyanate represented by formula (a2). The structural unit represented by formula (A1) is preferably a repeating unit contained in the main chain of the polyurethane, and therefore, the structure represented by (A) is also preferably contained in the main chain of the polyurethane.

[0022] [ka]

[0023] R 1 is R in formula (A). 1 The same applies to the preferred embodiments thereof.

[0024] R 2 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent.

[0025] R 2 The number of carbon atoms in the hydrocarbon group represented by the formula is preferably 1 or more and 24 or less, more preferably 2 or more and 20 or less, even more preferably 3 or more and 18 or less, still more preferably 4 or more and 16 or less, and particularly preferably 5 or more and 14 or less.

[0026] R 2 is a residue obtained by removing two isocyanate groups (-NCO) from a diisocyanate represented by formula (a2). The diisocyanate represented by formula (a2) is not particularly limited as long as it is a diisocyanate that can be used in the production of polyurethane by reaction with a polyol, but is preferably a diisocyanate that is commonly used in the production of polyurethane. Specifically, preferred examples of the diisocyanate represented by formula (a2) include pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), tolylene diisocyanate (TDI), naphthalene diisocyanate (NDI), xylylene diisocyanate (XDI), and bis(isocyanatomethyl)cyclohexane (hydrogenated XDI), with HDI, MDI, hydrogenated MDI, or TDI being more preferred. Therefore, R 2 The hydrocarbon group having 1 to 32 carbon atoms represented by the formula (I) is preferably a residue obtained by removing two isocyanate groups from PDI, HDI, IPDI, MDI, hydrogenated MDI, TDI, NDI, XDI, or hydrogenated XDI, and more preferably a residue obtained by removing two isocyanate groups from HDI, MDI, hydrogenated MDI, or TDI.

[0027] Specific preferred examples of the diol represented by formula (a1) include the following compounds:

[0028] [ka]

[0029] Specific examples of the structural unit represented by formula (A1) preferably include the following structural units.

[0030] [ka]

[0031] [ka]

[0032] [ka]

[0033] The polyurethane having the structural unit represented by formula (A1) preferably further has a structural unit represented by formula (A2). The structural unit represented by formula (A2) is, for example, a structural unit formed by the reaction of a diol represented by formula (a3) ​​with a diisocyanate represented by formula (a2).

[0034] [ka]

[0035] R 2 is R in formula (A1). 2 The preferred embodiments of R in formula (A1) are also the same. 2 and R in formula (A2) 2 may be the same or different from each other, but It is preferable that

[0036] R 3 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R a1 (OR a1 ) n1 -*, *-R a2 (Si(R a3 )2O) n2 Si(R a3 )2Ra2 -*, *-((CH2) x OCOR a4 COO) n3 (CH2) x A group represented by -*, or *-((C(R a6 )2) z COO) n4 R a5 (OCO(C(R a6 )2) z ) n4 - represents a group represented by *, and preferably *-R a1 (OR a1 ) n 1-*. In the present disclosure, "*" in the formula indicates the bonding position.

[0037] R 3 The number of carbon atoms in the hydrocarbon group represented by the formula is preferably 1 or more and 24 or less, more preferably 2 or more and 20 or less, even more preferably 3 or more and 18 or less, still more preferably 4 or more and 16 or less, and particularly preferably 5 or more and 14 or less.

[0038] R 3 Specific examples of the hydrocarbon group having 1 to 32 carbon atoms represented by the formula (I) include alkylene groups such as methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, decamethylene, dodecamethylene, tetradecamethylene, hexadecamethylene, and octadecamethylene; cycloalkylene groups such as cyclohexanediyl and adamantanediyl; arylene groups such as phenylene, biphenyldiyl, naphthalenediyl, anthracenediyl, phenanthrenediyl, triphenylenediyl, and pyrenediyl; arylene alkylene arylene groups such as phenylene dimethylmethylene phenylene; and alkylene arylene alkylene groups such as xylylene.

[0039] R a1 represents an alkylene group having 1 to 6 carbon atoms. a1may be the same or different from each other, but are preferably the same.

[0040] R a1 The alkylene group represented by the formula (I) preferably has 1 or more and 4 or less, more preferably 2 or more and 4 or less, and even more preferably 2 or 4 carbon atoms.

[0041] R a1 Specific examples of the alkylene group having 1 to 6 carbon atoms represented by the formula (I) include a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group, and are preferably a methylene group, an ethylene group, a propylene group, a trimethylene group, or a tetramethylene group, and more preferably an ethylene group, a propylene group, or a tetramethylene group.

[0042] n1 represents an integer of 1 or more and 100 or less, preferably an integer of 10 or more and 80 or less, more preferably an integer of 20 or more and 70 or less, even more preferably an integer of 30 or more and 60 or less, and even more preferably an integer of 40 or more and 50 or less.

[0043] *-R a1 (OR a1 ) n1 Specific examples of the group represented by -* include the group represented by formula (a3): Specific examples of the diol include residues obtained by removing hydrogen atoms from the terminal hydroxy groups of polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutylene glycol, which will be described later.

[0044] R a2 represents an alkylene group having 1 to 10 carbon atoms in which -CH2- may be replaced by -O-, or a single bond. a2 may be the same or different from each other, but are preferably the same.

[0045] R a2The alkylene group represented by the formula (I) preferably has 1 or more and 8 or less, more preferably 2 or more and 6 or less, even more preferably 3 or more and 6 or less, and even more preferably 4 or 5 carbon atoms.

[0046] R a2 Specific examples of the alkylene group having 1 to 10 carbon atoms in which -CH2- represented by the formula (I) may be replaced by -O- include a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a group represented by *-CH2CH2OCH2CH2-*, and a group represented by *-CH2CH2CH2OCH2CH2-*, and the like, and preferably a group represented by *-CH2CH2CH2OCH2CH2-*.

[0047] R a3 represents a hydrocarbon group having 1 to 10 carbon atoms. a3 may be the same or different from each other, but are preferably the same.

[0048] R a3 The number of carbon atoms in the hydrocarbon group represented by the formula (I) is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, even more preferably 1 or more and 3 or less, and even more preferably 1.

[0049] R a3 Specific examples of the hydrocarbon group represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, an n-decyl group, and the like. Of these, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, or a tert-butyl group is preferred, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group is more preferred, a methyl group or an ethyl group is even more preferred, and a methyl group is even more preferred.

[0050] n2 represents an integer of 1 or more and 100 or less, preferably an integer of 5 or more and 90 or less, more preferably an integer of 10 or more and 80 or less, and even more preferably an integer of 50 or more and 75 or less.

[0051] *-R a2 (Si(R a3 )2O) n2 Si(R a3 )2R a2 Specific examples of the group represented by -* include residues obtained by removing hydrogen atoms from the terminal hydroxy groups of polysiloxane diols described below as specific examples of diols represented by formula (a3).

[0052] R a4 is a phenylene group or -(CH2) y - represents a group represented by *. a4 may be the same or different from each other, but are preferably the same.

[0053] R a4 The phenylene group represented by the formula (I) may be any of a 1,4-phenylene group, a 1,3-phenylene group, and a 1,2-phenylene group. That is, *-((CH2) x OCOR a4 COO) n3 (CH2) x The group represented by -* is a polyester diol obtained by copolymerizing a benzenedicarboxylic acid component selected from terephthalic acid, isophthalic acid, and phthalic acid with an alkylene glycol component, and having hydroxy groups derived from the alkylene glycol component at both ends of the polyester.

[0054] x represents an integer of 1 or more, preferably an integer of 1 or more and 100 or less, more preferably an integer of 2 or more and 100 or less, even more preferably an integer of 2 or more and 45 or less, still more preferably an integer of 2 or more and 14 or less, and particularly preferably an integer of 2 or more and 4 or less. Multiple x's may be the same or different from each other.

[0055] y represents an integer of 0 or more, preferably an integer of 0 or more and 100 or less, more preferably an integer of 2 or more and 100 or less, even more preferably an integer of 2 or more and 45 or less, still more preferably an integer of 2 or more and 14 or less, and particularly preferably an integer of 4 or more and 14 or less. Multiple y's may be the same or different.

[0056] n3 represents an integer of 2 or more, preferably an integer of 2 or more and 100 or less, more preferably an integer of 3 or more and 20 or less, even more preferably an integer of 4 or more and 10 or less, and even more preferably an integer of 4 or more and 7 or less.

[0057] *-((CH2) x OCOR a4 COO) n3 (CH2) x Specific examples of the group represented by -* include residues obtained by removing hydrogen atoms from terminal hydroxy groups of polyester diols described below as specific examples of diols represented by formula (a3).

[0058] R a5 R represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent. a5 The hydrocarbon group having 1 to 32 carbon atoms and optionally having a substituent represented by R 3 The meaning is the same as that of the hydrocarbon group having 1 to 32 carbon atoms which may have a substituent and which is represented by the following formula: and the preferred embodiments thereof are also the same.

[0059] R a6 represents a hydrogen atom or a methyl group. a6 may be the same or different from each other. Two R a6 are preferably both hydrogen atoms, or one is a hydrogen atom and the other is a methyl group.

[0060] z represents an integer of 1 or more, preferably an integer of 1 or more and 100 or less, more preferably an integer of 2 or more and 45 or less, and even more preferably an integer of 4 or more and 14 or less. Multiple z's may be the same or different from each other.

[0061] n4 represents an integer of 1 or more and 1,000 or less, preferably an integer of 1 or more and 500 or less, more preferably an integer of 2 or more and 400 or less, even more preferably an integer of 3 or more and 100 or less, and even more preferably an integer of 4 or more and 50 or less. Multiple n4s may be the same or different from each other.

[0062] *-((C(R a6 )2) z COO) n4 R a5 (OCO(C(R a6 )2) z ) n4 Specific examples of the group represented by -* include residues obtained by removing hydrogen atoms from terminal hydroxy groups of polyester diols described below as specific examples of diols represented by formula (a3).

[0063] Specific preferred examples of the diol represented by formula (a3) ​​include ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, polyethylene glycol, polypropylene glycol, polybutylene glycol, bisphenol A, the following polysiloxane diols, and the following polyester diols, etc. In the following formula, n2, n3, and n4 are as defined above.

[0064] [ka]

[0065] Specific examples of the structural unit represented by formula (A2) include the following structural units: In the following formula, n1 is as defined above.

[0066] [ka]

[0067] When the polyurethane contains a structural unit represented by formula (A1), the content of the structural unit represented by formula (A1) in the polyurethane is preferably 10 mol % or more and 100 mol % or less, more preferably 30 mol % or more and 100 mol % or less, even more preferably 50 mol % or more and 100 mol % or less, and still more preferably 70 mol % or more and 100 mol % or less, from the viewpoint of exhibiting the heat resistance and mechanical strength derived from the bifuran skeleton. As shown in the Examples below, it is believed that the bifuran skeleton self-assembles through π-π interactions and functions like a hard segment. Therefore, for example, by setting the content of the structural unit represented by formula (A1) containing the bifuran skeleton to a higher range than above, it is possible to produce a polyurethane that is suppressed from flowing under high-temperature conditions and can maintain its shape.

[0068] Furthermore, when a polyurethane contains a structural unit represented by formula (A1) and a structural unit represented by formula (A2), the content of the structural unit represented by formula (A2) in the polyurethane is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 20 mol% to 70 mol%, from the viewpoint of exhibiting properties derived from the structural unit represented by formula (A2), such as flexibility. Furthermore, the content of the structural unit represented by formula (A1) in the polyurethane is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 30 mol% to 80 mol%, from the same viewpoints as above.

[0069] A suitable embodiment of the polyurethane having the structure represented by formula (B) is a polyurethane having a structural unit represented by formula (B1). The structural unit represented by formula (B1) is a structural unit formed, for example, by the reaction of a diol represented by formula (b1) with a diisocyanate represented by formula (b2).

[0070] [ka]

[0071] R 1 is R in formula (B) 1 The same applies to the preferred embodiments thereof.

[0072] R 4 represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R b1 (OR b1 ) m1 -*, *-R b2 (Si(R b3 )2O) m2 Si(R b3 )2R b2 -*, *-((CH2) p OCOR b4 COO) m3 (CH2) p A group represented by -*, or *-((C(R b6 )2) r COO) m4 R b5 (OCO(C(R b6 )2) r ) m4 - represents a group represented by *, preferably a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R b1 (OR b1 ) m1 -* or *-R b2 (Si(R b3 )2O) m2 Si(R b3 )2R b2 - is a group represented by *.

[0073] R 4 The number of carbon atoms in the hydrocarbon group represented by the formula is preferably 2 or more and 24 or less, more preferably 3 or more and 16 or less, and even more preferably 4 or more and 12 or less.

[0074] R 4Specific examples of the hydrocarbon group having 1 to 32 carbon atoms represented by the formula (I) include alkylene groups such as methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, decamethylene, dodecamethylene, tetradecamethylene, hexadecamethylene, and octadecamethylene; cycloalkylene groups such as cyclohexanediyl and adamantanediyl; arylene groups such as phenylene, biphenyldiyl, naphthalenediyl, anthracenediyl, phenanthrenediyl, triphenylenediyl, and pyrenediyl; arylene alkylene arylene groups such as phenylene dimethylmethylene phenylene; and alkylene arylene alkylene groups such as xylylene.

[0075] R b1 represents an alkylene group having 1 to 6 carbon atoms. b1 may be the same or different from each other, but are preferably the same.

[0076] R b1 The alkylene group represented by the formula (I) preferably has 1 or more and 4 or less, more preferably 2 or more and 4 or less, and even more preferably 2 or 4 carbon atoms.

[0077] R b1 Specific examples of the alkylene group having 1 to 6 carbon atoms represented by the formula (I) include a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group, and are preferably a methylene group, an ethylene group, a propylene group, a trimethylene group, or a tetramethylene group, and more preferably an ethylene group, a propylene group, or a tetramethylene group.

[0078] m1 represents an integer of 1 or more and 100 or less, preferably 2 or more and 80 or less, more preferably 5 or more and 70 or less, even more preferably 10 or more and 60 or less, and even more preferably 20 or more and 50 or less.

[0079] *-R b1 (ORb1 ) m1 Specific preferred examples of the group represented by -* include residues obtained by removing the hydrogen atom of a terminal hydroxy group from polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polybutylene glycol, which will be described later as specific examples of the diol represented by formula (b1).

[0080] R b2 represents an alkylene group having 1 to 10 carbon atoms in which -CH2- may be replaced by -O-. b2 may be the same or different from each other, but are preferably the same.

[0081] R b2 The alkylene group represented by the formula (I) preferably has 1 or more and 8 or less, more preferably 2 or more and 6 or less, even more preferably 3 or more and 6 or less, and even more preferably 4 or 5 carbon atoms.

[0082] R b2 Specific examples of the alkylene group having 1 to 10 carbon atoms in which -CH2- represented by the formula (I) may be replaced by -O- include a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a group represented by *-CH2CH2OCH2CH2-*, and a group represented by *-CH2CH2CH2OCH2CH2-*, and the like, and preferably a group represented by *-CH2CH2CH2OCH2CH2-*.

[0083] R b3 represents a hydrocarbon group having 1 to 10 carbon atoms. b3 may be the same or different from each other, but are preferably the same.

[0084] R b3 The number of carbon atoms in the hydrocarbon group represented by the formula (I) is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, even more preferably 1 or more and 3 or less, and even more preferably 1.

[0085] Rb3 Specific examples of the hydrocarbon group represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, an n-decyl group, and the like. Of these, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, or a tert-butyl group is preferred, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group is more preferred, a methyl group or an ethyl group is even more preferred, and a methyl group is even more preferred.

[0086] m2 represents an integer of 1 or more and 100 or less, preferably 5 or more and 90 or less, more preferably 10 or more and 80 or less, and further preferably 50 or more and 75 or less.

[0087] *-R b2 (Si(R b3 )2O) m2 Si(R b3 )2R b2 Specific examples of the group represented by -* include residues obtained by removing hydrogen atoms from terminal hydroxy groups of polysiloxane diols, which will be described later as specific examples of diols represented by formula (b1).

[0088] R b4 is a phenylene group or -(CH2) q - represents a group represented by *. b4 may be the same or different from each other, but are preferably the same.

[0089] R b4 The phenylene group represented by the formula (I) may be any of a 1,4-phenylene group, a 1,3-phenylene group, and a 1,2-phenylene group. That is, *-((CH2) p OCOR b4 COO) m3 (CH2) pThe group represented by -* is a polyester obtained by copolymerizing a benzenedicarboxylic acid component selected from terephthalic acid, isophthalic acid, and phthalic acid with an alkylene glycol component, and having hydroxy groups derived from the alkylene glycol component at both ends of the polyester. It is a polyester diol.

[0090] p represents an integer of 1 or more, preferably an integer of 1 or more and 100 or less, more preferably an integer of 2 or more and 100 or less, even more preferably an integer of 2 or more and 45 or less, still more preferably an integer of 2 or more and 14 or less, and particularly preferably an integer of 2 or more and 4 or less. Multiple p's may be the same or different from each other.

[0091] q represents an integer of 0 or more, preferably an integer of 0 or more and 100 or less, more preferably an integer of 2 or more and 100 or less, even more preferably an integer of 2 or more and 45 or less, still more preferably an integer of 2 or more and 14 or less, and particularly preferably an integer of 4 or more and 14 or less. Multiple q's may be the same or different from each other.

[0092] m3 represents an integer of 2 or more, preferably an integer of 2 or more and 100 or less, more preferably an integer of 3 or more and 20 or less, even more preferably an integer of 4 or more and 10 or less, and even more preferably an integer of 4 or more and 7 or less.

[0093] *-((CH2) p OCOR b4 COO) m3 (CH2) p Specific examples of the group represented by -* include residues obtained by removing hydrogen atoms from terminal hydroxy groups of polyester diols described below as specific examples of diols represented by formula (b1).

[0094] R b5 R represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent. b5 The hydrocarbon group having 1 to 32 carbon atoms and optionally having a substituent represented by R 4The meaning is the same as that of the hydrocarbon group having 1 to 32 carbon atoms which may have a substituent and which is represented by the following formula: and the preferred embodiments thereof are also the same.

[0095] R b6 represents a hydrogen atom or a methyl group. b6 may be the same or different from each other. Two R b6 are preferably both hydrogen atoms, or one is a hydrogen atom and the other is a methyl group.

[0096] r represents an integer of 1 or more, preferably an integer of 1 or more and 100 or less, more preferably an integer of 2 or more and 45 or less, and even more preferably an integer of 4 or more and 14 or less. Multiple r's may be the same or different from each other.

[0097] m4 represents an integer of 1 or more and 1,000 or less, preferably an integer of 1 or more and 500 or less, more preferably an integer of 2 or more and 400 or less, even more preferably an integer of 3 or more and 100 or less, and even more preferably an integer of 4 or more and 50 or less. Multiple m4's may be the same or different from each other.

[0098] *-((C(R b6 )2) r COO) m4 R b5 (OCO(C(R b6 )2) r ) m4 Specific examples of the group represented by -* include residues obtained by removing hydrogen atoms from terminal hydroxy groups of polyester diols described below as specific examples of diols represented by formula (a3).

[0099] Specific preferred examples of the diol represented by formula (b1) include ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, polyethylene glycol, polypropylene glycol, polybutylene glycol, bisphenol A, the following polysiloxane diols, and the following polyester diols. Note that m2, m3, and m4 in the following formula are as defined above.

[0100] [ka]

[0101] Specific examples of the structural unit represented by formula (B1) include the following structural units: In the following formula, m1 and m2 are as defined above.

[0102] [ka]

[0103] When the polyurethane according to this embodiment has a structural unit represented by formula (B1), it preferably further has a structural unit represented by formula (B2). The structural unit represented by formula (B2) is a structural unit formed, for example, by the reaction of the diol represented by formula (b1) and the diisocyanate represented by formula (b3).

[0104] [ka]

[0105] R 4 is R in formula (B1) 4 The preferred embodiments of R in formula (B1) are also the same as those of the formula (B1). 4 and R in formula (B2) 4 and may be the same or different from each other, but are preferably the same.

[0106] R 5R represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent. 5 is R in formula (A1). 2 Therefore, the diisocyanate represented by formula (b3) has the same meaning as the diisocyanate represented by formula (a2). The preferred embodiments are also the same.

[0107] Specific examples of the structural unit represented by formula (B2) include the following structural units: In the following formula, m1 and m2 are as defined above.

[0108] [ka]

[0109] When the polyurethane contains a structural unit represented by formula (B1), the content of the structural unit represented by formula (B1) in the polyurethane is preferably 10 mol % or more and 100 mol % or less, more preferably 30 mol % or more and 100 mol % or less, even more preferably 50 mol % or more and 100 mol % or less, and still more preferably 70 mol % or more and 100 mol % or less, from the viewpoint of exhibiting the heat resistance and mechanical strength derived from the bifuran skeleton.

[0110] Furthermore, when the polyurethane contains a structural unit represented by formula (B1) and a structural unit represented by formula (B2), the content of the structural unit represented by formula (B2) in the polyurethane is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 20 mol% to 70 mol%, from the viewpoint of exhibiting properties derived from the structural unit represented by formula (B2), such as flexibility. Furthermore, the content of the structural unit represented by formula (B1) in the polyurethane is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 30 mol% to 80 mol%, from the same viewpoints as above.

[0111] The weight average molecular weight (M w ) is not particularly limited, and Specifically, the number average molecular weight (M n ) is preferably 1.0 × 10 3 Over 1,000 x 10 3 is less than or equal to 2.0 x 10 3 Over 500 x 10 3 Below, 10 x 10 3 Over 200 x 10 3 Below, 20 x 10 3 Over 150 x 10 3 Below, 5.0 x 10 3 Over 100 x 10 3 Below, 10 x 10 3 Over 80 x 10 3 or less, or 15 x 10 3 Over 50 x 10 3 The weight average molecular weight (M w ) can be adjusted by the reaction solvent, reaction temperature, reaction time, monomer concentration, etc.

[0112] The number average molecular weight (M n ) is not particularly limited and may be appropriately set depending on the application of the polyurethane. Specifically, the number average molecular weight (M n ) is preferably 0.5 × 10 3 Over 1,000 x 10 3 is less than or equal to 1.0 x 10 3 Over 500 x 10 3 Below, 3.0 x 10 3 Over 100 x 10 3 Below, 4.0 x 10 3 Over 50 x 10 3 Below, 5.0 x 10 3 Over 30 x 10 3 Below, 10 x 10 3 Over 25 x 10 3 or less, or 15 x 10 3 Over 20 x 10 3 The number average molecular weight (M n) can be adjusted by the reaction solvent, reaction temperature, reaction time, monomer concentration, etc.

[0113] The polydispersity (M w / M n ) is not particularly limited and may be appropriately set depending on the application of the polyurethane. Specifically, the polydispersity (M w / M n ) is preferably 1.0 or more and 10 or less, and may be 1.2 or more and 9.0 or less, 1.6 or more and 8.0 or less, 1.8 or more and 7.0 or less, 2.0 or more and 6.0 or less, or 2.0 or more and 5.0 or less. w / M n ) can be adjusted by the reaction solvent, reaction temperature, reaction time, etc.

[0114] The number average molecular weight (M n ) and weight average molecular weight (M w As shown in the Examples below, the chromatographic analysis is performed by size exclusion chromatography (SEC) using a calibration curve obtained with standard polystyrene or pullulan. SEC is performed using a high-speed GPC apparatus such as the "HLC-8220GPC" manufactured by Tosoh Corporation, using DMSO or chloroform as the solvent.

[0115] 2. Polyurethane manufacturing method The method for producing polyurethane according to this embodiment is not particularly limited, and may be a production method including any polymerization reaction using monomers from which the structural units described above are derived. As a production method including any polymerization reaction, a production method including a reaction step of reacting a diol with a diisocyanate is preferred. Hereinafter, a method for producing polyurethane including a reaction step of reacting a diol with a diisocyanate will be described.

[0116] 2-1.Monomer In the reaction step, one or more monomers selected from the group consisting of diols represented by formula (a1) and diisocyanates represented by formula (b2) are used as monomers for producing polyurethane. The diols represented by formula (a1) are monomers capable of introducing the structure represented by formula (A) into polyurethane. The diisocyanates represented by formula (b2) are monomers capable of introducing the structure represented by formula (B) into polyurethane.

[0117] When the diol contains a diol represented by formula (a1), the diisocyanate preferably contains a diisocyanate represented by formula (a2), which makes it possible to produce a polyurethane having a structural unit represented by formula (A1). Furthermore, when the diol contains a diol represented by formula (a1), the diol preferably further contains a diol represented by formula (a3). This makes it possible to produce a polyurethane having a structural unit represented by formula (A1) and a structural unit represented by formula (A2). .

[0118] When the diol contains a diol represented by formula (a1), the content of the diol represented by formula (a1) in the total amount of diols is not particularly limited, but from the viewpoint of improving the heat resistance and mechanical strength of the polyurethane, it is preferably from 10 mol% to 100 mol%, more preferably from 30 mol% to 100 mol%, even more preferably from 50 mol% to 100 mol%, and still more preferably from 70 mol% to 100 mol%.

[0119] When the diol contains a diol represented by formula (a1) and a diol represented by formula (a3), the content of the diol represented by formula (a3) ​​in the total amount of diols is not particularly limited, but from the viewpoint of ensuring the flexibility of the polyurethane, it is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 20 mol% to 70 mol%. Also, from the same viewpoint as above, the content of the diol represented by formula (a1) in the total amount of diols is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 30 mol% to 80 mol%.

[0120] When the diisocyanate contains the diisocyanate represented by formula (b2), the diol preferably contains the diol represented by formula (b1), which makes it possible to produce a polyurethane having a structural unit represented by formula (B1). Furthermore, when the diisocyanate contains a diisocyanate represented by formula (b2), the diisocyanate preferably further contains a diisocyanate represented by formula (b3). This makes it possible to produce a polyurethane having a structural unit represented by formula (B1) and a structural unit represented by formula (B2).

[0121] When the diisocyanate contains a diisocyanate represented by formula (b2), the content of the diisocyanate represented by formula (b2) in the total amount of diisocyanates is not particularly limited, but from the viewpoint of improving the heat resistance and mechanical strength of the polyurethane, it is preferably 10 mol% or more and 100 mol% or less, more preferably 30 mol% or more and 100 mol% or less, even more preferably 50 mol% or more and 100 mol% or less, and still more preferably 70 mol% or more and 100 mol% or less.

[0122] When the diisocyanate contains a diisocyanate represented by formula (b2) and a diisocyanate represented by formula (b3), the content of the diisocyanate represented by formula (b3) in the total amount of diisocyanates is not particularly limited, but from the viewpoint of ensuring the flexibility of the polyurethane, it is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 20 mol% to 70 mol%. Furthermore, from the same viewpoint as above, the content of the diisocyanate represented by formula (b2) in the total amount of diisocyanates is preferably 5 mol% to 95 mol%, more preferably 10 mol% to 90 mol%, and even more preferably 30 mol% to 80 mol%.

[0123] The amounts (charge amounts) of the diol and diisocyanate used in the reaction step are not particularly limited, but the amount (charge amount) of the diisocyanate used relative to the substance amount of the diol is preferably 0.8 equivalents or more and 1.2 equivalents or less, more preferably 0.9 equivalents or more and 1.1 equivalents or less, even more preferably 0.9 equivalents or more and 1.0 equivalents or less, and still more preferably 1.0 equivalent.

[0124] 2-2. Synthesis of diisocyanates For example, as shown in Scheme 1, the diisocyanate represented by formula (b2) can be prepared by a process comprising the steps of: azidating a dicarboxylic acid represented by formula (b2-1) to obtain a diacyl azide represented by formula (b2-2); and then subjecting the acyl azide represented by formula (b2-2) to a Curtius rearrangement. and a Curtius rearrangement step of carrying out the following:

[0125] [ka]

[0126] 2-2-1. Azidization process The azidation of the dicarboxylic acid represented by formula (b2-1) can be carried out by any method, such as a method of reacting the dicarboxylic acid represented by formula (b2-1) with an azidating agent such as diphenylphosphoryl azide (DPPA), or a method of converting the dicarboxylic acid represented by formula (b2-1) into an acid halide and reacting it with an azidating agent such as sodium azide, trimethylsilyl azide, tetrabutylammonium azide, or tributyltin azide. As the azidation method, a method of reacting the dicarboxylic acid represented by formula (b2-1) with an azidating agent is preferred.

[0127] The reaction solvent is not particularly limited as long as it does not inhibit the reaction, and examples thereof include aprotic polar solvents, hydrocarbon solvents, and ether solvents, with aprotic polar solvents being preferred. The aprotic polar solvents, hydrocarbon solvents, and ether solvents that can be used in the reaction step in polyurethane production can be the same as the aprotic polar solvents, hydrocarbon solvents, and ether solvents listed above. The solvents may be used alone, or two or more may be used in any combination and ratio.

[0128] The reaction temperature in the azidation step is preferably 0° C. or higher and 40° C. or lower, more preferably room temperature. In the present disclosure, "room temperature" refers to a temperature condition where no intentional heating or cooling is performed, specifically a temperature range of 20° C. or higher and 30° C. or lower. The reaction time for azidation is preferably 1 hour or more and 30 hours or less, more preferably 5 hours or more and 20 hours or less.

[0129] 2-2-2. Curtius rearrangement process In the Curtius rearrangement step, a diisocyanate represented by formula (b2) is produced by Curtius rearrangement of a diacyl azide represented by formula (b2-2).

[0130] The Curtius rearrangement of the diacyl azide represented by formula (b2-2) can be easily induced by heating. The Curtius rearrangement of the diacyl azide represented by formula (b2-2) does not particularly require a reactant such as a catalyst, but is preferably carried out in the presence of a base such as triethylamine and sodium bicarbonate.

[0131] The reaction solvent for the Curtius rearrangement can also be used in the reaction step, so after the Curtius rearrangement step, the reaction solution can be directly used in the reaction step without separating and purifying the product. When the reaction solution is used as it is in the reaction step, and the amount of the diisocyanate used is adjusted as described above, it is treated as if the diisocyanate represented by formula (b2) is quantitatively produced from the diacyl azide represented by formula (b2-2), and the amount (charge amount) of the diacyl azide represented by formula (b2-2) used in the Curtius rearrangement step is regarded as the amount (charge amount) of the diisocyanate represented by formula (b2) used in the reaction step.

[0132] 2-3. Urethane catalyst The reaction between the diol and the diisocyanate is preferably carried out in the presence of a urethanization catalyst. The urethanization catalyst is not particularly limited as long as it can promote the production of polyurethane by the reaction between the diol and the diisocyanate, and any urethanization catalyst can be used. Examples of the urethanization catalyst include metal catalysts and amine catalysts, and metal catalysts are preferred.

[0133] Examples of metal catalysts include tin compounds such as tin acetate, tin 2-ethylhexanoate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin maleate, and dibutyltin dichloride; lead compounds such as lead octoate, lead naphthenate, lead oleate, and lead 2-ethylhexanoate; nickel compounds such as nickel naphthenate; cobalt compounds such as cobalt octoate and cobalt naphthenate; bismuth compounds such as bismuth octoate, bismuth 2-ethylhexanoate, bismuth oleate, bismuth neodecanoate, and bismuth naphthenate; and titanium compounds such as titanium tetrachloride, dibutyltitanium dichloride, tetraethoxytitanium, and tetrabutoxytitanium. Among these, tin compounds are preferred as metal catalysts, and dibutyltin dilaurate is more preferred.

[0134] Amine catalysts include triethylamine, N,N-dimethylcyclohexylamine, triethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylpropylenediamine, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N,N',N'-tetramethylhexamethylenediamine, 1-(2-dimethylaminoethyl)-4-methylpiperazine, N-methylmorpholine, and N-ethyl Examples include morpholine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, 1-dimethylaminopropylimidazole, and 1-(2-hydroxyethyl)imidazole.

[0135] The urethanization catalyst may be used alone or as a mixture of two or more kinds in any combination and ratio.

[0136] When a diol and a diisocyanate are reacted in the presence of a urethanization catalyst, the amount of the urethanization catalyst used (charged amount) is not particularly limited, but is preferably 0.1 mol% or more and 20 mol% or less, more preferably 0.5 mol% or more and 15 mol% or less, even more preferably 1.0 mol% or more and 10 mol% or less, and still more preferably 2.0 mol% or more and 5.0 mol% or less, based on the diol.

[0137] 2-4.Reaction solvent The reaction between the diol and the diisocyanate is usually carried out in a solvent. The type of reaction solvent can be appropriately selected depending on the solubility of the diol, diisocyanate, and the polyurethane to be produced, the desired molecular weight of the polyurethane, etc. The reaction solvent is preferably an anhydrous solvent in order to prevent a decrease in activity or deactivation of the urethanization catalyst.

[0138] Suitable reaction solvents include aprotic polar solvents, hydrocarbon solvents, halogenated hydrocarbon solvents, and ether solvents.

[0139] Examples of aprotic polar solvents include dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), dimethylacetamide (DMA), N-methylpyrrolidone (NMP), acetonitrile, and 1,3-dimethyl-2-imidazolidinone, and preferably dimethyl sulfoxide (DMSO).

[0140] Examples of hydrocarbon solvents include aromatic hydrocarbon solvents such as benzene, toluene, xylene, and mesitylene; and aliphatic hydrocarbon solvents such as hexane, heptane, cyclohexane, methylcyclohexane, octane, pentane, and cyclopentane.

[0141] Examples of halogenated hydrocarbon solvents include dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethylene, tetrachloroethylene, monochlorobenzene, dichlorobenzene, and chlorotoluene.

[0142] Examples of ether solvents include dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, tert-butyl methyl ether, cyclopentyl methyl ether, cyclohexyl methyl ether, anisole, 1,2-dioxane, 1,3-dioxane, 1,4-dioxane, and tetrahydrofuran (THF).

[0143] The reaction solvent may be used alone or in any combination of two or more in any ratio.

[0144] The amount of reaction solvent used is not particularly limited and may be appropriately selected depending on the type of monomer, the presence or absence of a urethanization catalyst, the properties of the polyurethane to be produced, etc. The amount of reaction solvent used is preferably set so that the monomer concentration in the reaction solution falls within a predetermined range. More specifically, the diol concentration in the reaction solution is preferably 0.05 M or more and 2.00 M or less, more preferably 0.10 M or more and 1.00 M or less, and even more preferably 0.20 M or more and 0.8 M or less, and it is preferable to adjust the amount of reaction solvent used so that the diol concentration falls within the above range.

[0145] 2-5. Reaction conditions, etc. The reaction conditions such as the reaction temperature and reaction time may be appropriately selected from reaction conditions that are usually employed in the field of polymer synthesis depending on various conditions such as the reactivity of the diol, the reactivity of the diisocyanate, the stability of the polyurethane, the presence or absence of a urethanization catalyst, and the reaction scale. Suitable reaction conditions for the reaction step include the following.

[0146] (Atmospheric gas) The reaction step may be carried out in an inert atmosphere or in the air. However, when the reaction is carried out in the presence of a urethanization catalyst, it is preferable to carry out the reaction in an inert atmosphere from the viewpoint of suppressing a decrease in the activity of the urethanization catalyst. Examples of the inert atmosphere include nitrogen and argon. These inert gases may be used alone or in any combination and ratio of two or more. The reaction step may be carried out under normal pressure or under increased pressure, but is preferably carried out under normal pressure.

[0147] (Reaction temperature) The reaction temperature is preferably 0° C. or higher and 150° C. or lower. More specifically, from the viewpoint of sufficiently proceeding the reaction, inhibiting the progress of depolymerization or decomposition of the polyurethane, and inhibiting an increase in the polydispersity of the polyurethane, the reaction temperature when an aromatic ring other than a bifuran skeleton is introduced into the polyurethane is preferably 0° C. or higher and 150° C. or lower, more preferably 20° C. or higher and 130° C. or lower, even more preferably 50° C. or higher and 120° C. or lower, and even more preferably 80° C. or higher. From the same viewpoint, when no aromatic ring other than the bifuran skeleton is introduced into the polyurethane, the reaction temperature is preferably 0°C or higher and 150°C or lower, more preferably 20°C or higher and 100°C or lower, even more preferably 30°C or higher and 80°C or lower, and even more preferably 40°C or higher and 60°C or lower.

[0148] (Reaction time) The reaction time is preferably 5 minutes to 48 hours, more preferably 10 minutes to 24 hours, even more preferably 20 minutes to 12 hours, and even more preferably 30 minutes to 2 hours. By setting the reaction time within the above range, the reaction between the diol and the diisocyanate can be sufficiently progressed, and the progress of depolymerization or decomposition of the produced polyurethane can be suppressed.

[0149] 2-6. Post-processing After the reaction step, the polyurethane in the reaction solution is preferably separated and purified by any method used in the field of polymer synthesis, such as filtration, adsorption, reprecipitation, etc.

[0150] 3. Uses of polyurethane The polyurethane according to this embodiment can exhibit thermal and mechanical properties derived from the bifuran skeleton. Furthermore, by incorporating structural units derived from polyalkylene glycol or structural units derived from polysiloxane into the polyurethane, it is possible to improve flexibility and elasticity. Therefore, the polyurethane according to this embodiment is expected to be applied to a variety of applications. For example, the polyurethane according to this embodiment can be used in applications such as fibers (especially elastic fibers), films, and plastic molded products such as foams. Furthermore, compositions containing this polyurethane and, if necessary, solvents and the like can be used in applications such as adhesives, pressure-sensitive adhesives, paints, and inks. It goes without saying that the plastic molded products and the compositions may contain optional additives (e.g., foaming agents, stabilizers, crosslinking agents, antioxidants, etc.). [Example]

[0151] The present disclosure will be described in more detail below with reference to examples, but modifications can be made as appropriate without departing from the spirit of the present disclosure. Therefore, the scope of the present disclosure should not be construed as being limited by the specific examples shown below.

[0152] <Example 1: Production of polyurethane having a structure represented by formula (A)> The methods for measuring the physical properties of polyurethane in the examples and comparative examples are as follows.

[0153] [Molecular weight measurement] The weight-average molecular weight and number-average molecular weight of the polyurethane were measured by size exclusion chromatography (SEC) using chloroform or DMSO as the measurement solvent.

[0154] Measurement using chloroform solvent The sample was dissolved in chloroform and filtered through a membrane filter with a pore size of 0.45 μm to prepare a measurement solution. Measurements were carried out using chloroform as the eluent at a temperature of 40°C and a flow rate of 1.0 mL / min. The measurement equipment used was a TSKgel MultiporeHXL-M (manufactured by Tosoh Corporation), a TSKgel GRCHR (manufactured by Tosoh Corporation), a guard column TSKgel guardcolumn MP(XL) (manufactured by Tosoh Corporation), and an HLC-8220GPC (manufactured by Tosoh Corporation) equipped with a UV detector. A calibration curve was prepared using TSK standard polystyrene. (Tosoh Corporation; number average molecular weight = 1.0 × 10 6 , 3.5×10 5 , 9.5×10 4 , 3.9 × 10 4 , 8.9×10 3 , 2.6×10 3 , 8.7×10 2 ) was used.

[0155] Measurement using DMSO solvent The sample was dissolved in 0.01M LiBr in DMSO and filtered through a 0.45μm membrane filter to prepare the measurement solution. Measurements were performed at 40℃ and a flow rate of 0.5mL / min using 0.01M LiBr in DMSO as the eluent. The measurement equipment used was a TSKgel SuperAWM-H (manufactured by Tosoh Corporation), a guard column TSKgel SuperAW-H (manufactured by Tosoh Corporation), and an HLC-8220GPC (manufactured by Tosoh Corporation) equipped with a refractive index detector. A calibration curve was prepared using Shodex standard pullulan (manufactured by Showa Denko K.K.; number average molecular weight = 20.1 × 10). 4 , 10.6×10 4 , 9.5×10 4 , 4.94×10 4 , 2.20×10 4 , 0.98×10 4 , 0.63×10 4 ) was used.

[0156] [Measurement of Nuclear Magnetic Resonance (NMR) Spectroscopy] Polyurethane 1 H NMR spectrum and 13C NMR spectra were measured using a JNM-ECS400 NMR spectrometer (manufactured by JEOL Ltd.) or a JNM-ECA600 NMR spectrometer (manufactured by JEOL Ltd.) The NMR measurement solvent was deuterated chloroform, deuterated acetone, or deuterated DMSO containing tetramethylsilane as an internal standard.

[0157] [Measurement of infrared absorption (IR) spectrum] An FT / IR-4700 Fourier transform infrared spectrophotometer (manufactured by JASCO Corporation) was equipped with an ATR PRO ONE (manufactured by JASCO Corporation), and the IR spectrum of the polyurethane was measured using the single-reflection attenuated total reflection (ATR) method.

[0158] [Differential Scanning Calorimetry (DSC)] The differential scanning calorimeter was a Pyris-Diamond DSC (Perkin An aluminum pan was used, and the temperature was raised from -60°C to the specified temperature at a rate of 10.0°C / min under a nitrogen atmosphere (20 mL / min), held for 3 minutes, then lowered to -60°C at a rate of 10.0°C / min, held for 3 minutes, and then raised to the specified temperature at a rate of 10.0°C / min for measurement.

[0159] [Dynamic Mechanical Analysis (DMA)] Dynamic mechanical analysis (DMA) was performed using a DMA-8000 (Perkin Elmer Co., Ltd.) with a stainless steel material pocket containing the powder sample. The measurement was performed in single cantilever mode, with a vibration frequency of 0.1 Hz or 1.0 Hz, a strain of 0.05 mm, and heating from -60°C to the specified temperature at a rate of 2°C / min.

[0160] <Example 1-1>

[0161] In a 50 mL Schlenk tube, bifurfuryl alcohol (0.25 mol) was added under nitrogen atmosphere. DMSO (1.0 mL), HDI (0.25 mol), and dibutyltin dilaurate (7.5 μmol) were added in this order and stirred at 110°C for 1 hour. Since a precipitate had formed in the reaction solution, DMSO (1.5 mL) was added to the reaction solution and heated to 120°C to dissolve the precipitate. The resulting solution was cooled and added dropwise to methanol (80 mL) to cause reprecipitation. The precipitate was collected and dried in vacuum at room temperature to obtain PU-1 as a white solid. The physical properties of the resulting polyurethane are shown in Table 1.

[0162] <Example 1-2> In a 50 mL Schlenk tube, bifurfuryl alcohol (0.75 mol) was added under nitrogen atmosphere. DMSO (1.0 mL), hydrogenated MDI (0.75 mol), and dibutyltin dilaurate (22.5 μmol) was added in this order, and the mixture was stirred at 110°C for 1 hour. Therefore, DMSO (1.5 mL) was added to the reaction solution and heated to 110°C to dissolve the precipitate. The resulting solution was cooled and added dropwise to methanol (80 mL) to cause reprecipitation. The precipitate was collected and dried in vacuum at room temperature to obtain PU-2 as a white solid. The physical properties of the resulting polyurethane are shown in Table 1.

[0163] <Examples 1-3 and 1-4> In a 50 mL Schlenk tube, bifurfuryl alcohol (0.51 mol) was added under nitrogen atmosphere. DMSO (1.0 mL), the diisocyanate (0.51 mol) shown in Table 1, and Djibouti Then, 15.3 μmol of dimethyltin dilaurate was added and the mixture was stirred at 50° C. for 1 hour. Since a precipitate was formed in the reaction mixture, the reaction mixture was cooled and added dropwise to methanol (30 mL) for reprecipitation. The precipitate was collected and dried in vacuo at room temperature to obtain PU-3 to PU-4, each as a white solid. The physical properties of the resulting polyurethane are shown in Table 1.

[0164] <Comparative Example 1-1> 2,5-bis(hydroxymethyl)furan (0.8 mmol), DMSO (1.0 mL), 4,4'-MDI (0.8 mmol), and dibutyltin dilaurate (0.024 mmol) were added in this order to a 50 mL Schlenk tube under a nitrogen atmosphere and stirred at 50 °C for 1 hour. After cooling, the reaction solution was added dropwise to methanol (30 mL) for reprecipitation. The precipitate was collected and dried in vacuo at room temperature to obtain PU-3(mono) as a white solid. The physical properties of the resulting polyurethane are shown in Table 1.

[0165] <Comparative Example 1-2> 2,5-bis(hydroxymethyl)furan (0.8 mmol), DMSO (1.0 mL), 2,4-TDI (0.8 mmol), and dibutyltin dilaurate (0.024 mmol) were added in this order to a 50 mL Schlenk tube under a nitrogen atmosphere and stirred at 50 °C for 1 hour. After cooling, the reaction solution was added dropwise to distilled water (10 mL) to cause reprecipitation. The precipitate was collected and dried in vacuum at room temperature to obtain PU-4(mono) as a white solid. The physical properties of the resulting polyurethane are shown in Table 1.

[0166] [Table 1]

[0167] PU-1 1 H NMR measurement results 1 H NMR (400 MHz, DMSO-d6): δ 7.27 (m, 2H), 6.58-6.64 (m, 4H), 6.38-6.39 (d, J = 3.2 Hz, terminal-furan ring), 5.70 (m, terminal-NH2), 5.29-5.32 (t, J = 6.0 Hz, terminal-OH), 5.00 (s, 4H), 4.40-4.41 (d, J = 5.6 Hz, terminal-furyl position), 2.93-2.95 (d, J = 6.0 Hz, 4H), 1.34 (m, 4H), 1.20 (m, 4H) ppm.

[0168] PU-1 IR measurement results IR: 3316 cm -1 (-NH-), 2857-2931 cm -1 (-CH-), 1685 cm -1 (-OC(=O)-NH-), 1538 cm -1 (-NH-), 1254cm -1 (-OC-), 777 cm -1 (-CH-).

[0169] PU-2の 1 H NMR results 1 H NMR (400 MHz, DMSO-d6) δ 7.21-7.24 (m, 2H), 6.58-6.65 (m, 4H), 6.38-6.39 (d, J = 2.8 Hz, terminal-furan ring), 5.30-5.33 (t, J = 5.6 Hz, terminal-OH), 4.95-4.96 (d, J = 4.0 Hz, 4H), 4.40-4.41 (d, J = 6.0 Hz, terminal-furyl position), 3.49-3.51 (m, 2H), 3.17-3.19 (m, 2H), 0.83-1.76 (m, 20H) ppm.

[0170] PU-2 IR measurement results IR: 3320 cm -1 (-NH-), 2851-2920 cm -1 (-CH-), 1695 cm -1 (-OC(=O)-NH-), 1520 cm -1 (-NH-), 1226 cm -1 (-OC-), 781 cm -1 (-CH-).

[0171] PU-3の1 H NMR results 1 H NMR (400 MHz, DMSO-d6): δ 9.73 (m, 2H), 8.52 (m, terminal-NH2), 7.07-7.34 (m, 8H), 6.63-6.70 (m, 4H), 6.37-6.39 (m, terminal-furan ring), 5.30 (m, terminal-OH), 5.12 (s, 4H), 4.41 (s, terminal-furyl position), 3.77 (s, 2H) ppm.

[0172] PU-3 IR measurement results IR: 3318 cm -1 (-NH-), 1704 cm -1 (-OC(=O)-NH-), 1521 cm -1 (-NH-), 1220 cm -1 (-OC-), 766 cm -1 (-CH-).

[0173] PU-4の 1 H NMR results 1 H NMR (400 MHz, DMSO-d6): δ 9.64-9.72 (m, 1H), 8.95-9.09 (m, 1H), 7.50 (m, 3H), 6.64-6.68 (m, 4H), 6.36-6.37 (d, J = 4.0 Hz, terminal-furan ring), 5.27-5.30 (t, J = 5.6 Hz, terminal-OH), 5.08-5.09 (d, J = 4.4 Hz, 4H), 4.38-4.39 (d, J = 5.6 Hz, terminal-furyl position), 2.06 (s, 3H) ppm.

[0174] PU-4 IR measurement results IR: 3285 cm -1 (-NH-), 1695 cm -1(-OC(=O)-NH-), 1527 cm -1 (-NH-), 1223 cm -1 (-OC-), 787 cm -1 (-CH-).

[0175] PU-3(mono)の 1 H NMR results 1 H NMR (400 MHz, DMSO-d6): δ 9.70 (m, 2H), 8.48 (m, terminal-NH2), 7.06-7.33 (m, 8H), 6.53 (s, 2H), 5.06 (s, 4H), 4.30 (m, terminal-furyl position), 3.75 (s, 2H) ppm.

[0176] IR measurement results of PU-3(mono) IR: 3307 cm -1 (-NH-), 1702 cm -1 (-OC(=O)-NH-), 1522 cm -1 (-NH-), 1218 cm -1 (-OC-), 765 cm -1 (-CH-).

[0177] PU-4(mono)の 1 H NMR results 1 H NMR (400 MHz, DMSO-d6): δ 9.73 (m, 1H), 8.98-9.11 (m, 1H), 7.51 (s, 1H), 7.12-7.14 (m, 1H), 7.04-7.06 (m, 1H), 6.46-6.55 (m, 2H), 6.26 (s, terminal-furan ri ng), 5.26-5.28 (m, terminal-OH), 5.04-5.08 (m, 4H), 4.37 (m, terminal-furyl position), 2.00-2.09 (m, 3H) ppm.

[0178] IR measurement results for PU-4 (mono) IR: 3289 cm -1 (-NH-), 1698 cm -1 (-OC(=O)-NH-), 1526 cm -1 (-NH-), 1220 cm -1 (-OC-), 765 cm -1 (-CH-).

[0179] [Evaluation of mechanical properties I] The polyurethane was melt-molded under the conditions shown in Table 2 to produce a polyurethane film. The toughness of this polyurethane film was evaluated by bending and stretching it. The results are shown in Table 2.

[0180] [Table 2]

[0181] Flexible films were obtained from PU-3 and PU-4. From this result, it is thought that aromatic polyurethanes such as PU-3 and PU-4 can produce tough films because the molecular chains are more closely entangled.

[0182] [Evaluation of mechanical properties II] A polyurethane solution was prepared by dissolving polyurethane in DMF, and the polyurethane solution was cast onto a substrate. The solution was then left at room temperature for 20 hours to evaporate the DMF, followed by drying under reduced pressure to produce a cast film.

[0183] A polyurethane film was sandwiched between Kapton (product number 120HR616, manufactured by Toray DuPont Co., Ltd.), a polytetrafluoroethylene-coated polyimide film, and this was then sandwiched between 1 mm thick stainless steel plates. Using a No. 10 hot press (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the mixture was compressed into a film measuring 30 x 10 x 0.10 mm under each molding condition. After compression, the melt-pressed film was slowly cooled to room temperature. The obtained film was cut into strip-shaped test pieces.

[0184] Tensile tests were performed on rectangular specimens at 23°C using a universal testing machine, EZ-Test (Shimadzu Corporation), to measure Young's modulus, tensile strength, and tensile breaking strain. The grip distance was 10 mm, and the tensile strength test speed was 10 mm / min. The tensile strength was determined as the maximum strength required to break the material on the stress-strain curve. The tensile breaking strain was determined as the maximum strain on the stress-strain curve. The results are shown in Table 3.

[0185] [Table 3]

[0186] It can be seen that the polyurethane film formed with PU-1 is a brittle film that breaks easily when stretched. Comparing PU-3 and PU-4, the Young's modulus of PU-4 was higher, but there was no significant difference in the tensile strength and tensile breaking strain. Furthermore, when comparing PU-3 with PU-3(mono), PU-3 had higher tensile strength and tensile breaking strain. PU-3 has a higher tensile strength than PU-3(mono), likely due to the strong π-π interactions between the molecular chains in the bifuran skeleton. These results suggest that the bifuran skeleton is a superior building block for high-strength materials than the monofuran ring.

[0187] [Evaluation of Mechanical Properties III] Dynamic mechanical analysis (DMA) was performed using a DMA-8000 (Perkin Elmer). Measurements were performed in single cantilever mode, with a vibration frequency of 0.1 Hz or 1.0 Hz, a strain of 0.05 mm, and heating at a rate of 2°C / min from -60°C to 170°C. The rectangular test specimens prepared in Evaluation of Mechanical Properties II were used for the measurements. Figure 1 shows the results of measuring the storage modulus of polyurethane by DMA, and Figure 2 shows the results of measuring the loss tangent of polyurethane by DMA.

[0188] As shown in Figure 1, the storage moduli of PU-3, PU-4, and PU-3(mono) at 25°C were confirmed to be 2.5 GPa, 2.5 GPa, and 2.1 GPa, respectively. PU-3 had higher strength than PU-3(mono), suggesting that the bifuryl skeleton has stronger rigidity and π-π interactions between molecular chains than the monofuran ring. The storage modulus of PU-3 drops sharply around 100°C. In contrast, the storage modulus of PU-3(mono) drops sharply around 50°C. These results show that a bifuryl skeleton provides higher heat resistance as a material than a monofuran ring.

[0189] In addition, a tan δ peak due to relaxation was observed at 83°C in PU-3 (mono). In PU-4, a tan δ peak was observed at 137°C and a decrease in storage modulus was observed. This decrease is thought to be due to thermal decomposition.

[0190] <Examples 1-5 to 1-9 and Comparative Example 1-3> Polyurethanes were obtained in the same manner as in Example 1-1, except that the diol was changed to one shown in Table 4. In Table 4, "PEG" stands for polyethylene glycol 2000 (manufactured by Tokyo Chemical Industry Co., Ltd.), which has a molecular length approximately 12 times that of the bifuryl skeleton. The physical properties of the obtained polyurethane are shown in Table 4. 1 The 1 H NMR spectrum is shown in Figure 3.

[0191] <Comparative Example 1-4> 2,5-bis(hydroxymethyl)furan (100 mg, 0.8 mmol), DMSO (0.2 mL), PEG2000 (670 mg, 0.34 mmol), HDI (0.18 mL, 0.78 mmol), and dibutyltin dilaurate (20 μL, 30 μmol) were added to a 50 mL Schlenk tube under a nitrogen atmosphere and reacted at 110 °C for 1 hour. After cooling, acetone (0.5 mL) was added to the reaction solution, and diethyl ether was added dropwise to the resulting solution to obtain a solid. This solid was collected and dried under vacuum at room temperature to obtain PF73PEG-H as a yellow solid. The physical properties of the obtained polyurethane are shown in Table 4. 1 The 1 H NMR spectrum is shown in Figure 4.

[0192] [Table 4]

[0193] <Examples 1-10 to 1-14 and Comparative Example 1-5> Polyurethanes were obtained in the same manner as in Example 1-2, except that the diols were changed to those shown in Table 5. In Table 5, "PEG" stands for polyethylene glycol 2000 (manufactured by Tokyo Chemical Industry Co., Ltd.), which has a molecular length approximately 12 times that of the bifuryl skeleton. The physical properties of the obtained polyurethane are shown in Table 5. 1 The 1 H NMR spectrum is shown in Figure 5.

[0194] [Table 5]

[0195] [Evaluation of mechanical properties IV] The polyurethane was melt-molded under the conditions shown in Table 6 to produce a polyurethane film. The toughness of this polyurethane film was evaluated by bending and stretching. The results are shown in Table 6.

[0196] [Table 6]

[0197] Table 6 shows that a polyurethane film having units derived from a diol having a bifuran skeleton and units derived from polyethylene glycol exhibits higher flexibility than a polyurethane film having units derived from a diol having a bifuran skeleton but not having units derived from polyethylene glycol.

[0198] [Evaluation of mechanical properties V] The results are shown in Table 7.

[0199] [Table 7]

[0200] PBF100PEG-H is a rigid film due to its high Young's modulus and tensile strength, while PBF69PEG-H is a ductile film due to its low Young's modulus and high tensile breaking strain.

[0201] [Evaluation of Mechanical Properties VI] Dynamic mechanical analysis (DMA) was performed using a DMA-8000 (Perkin Elmer Co., Ltd.). Measurements were performed in single cantilever mode, with a vibration frequency of 0.1 Hz or 1.0 Hz, a strain of 0.05 mm, and heating at a rate of 2°C / min from -60°C to 200°C. Polyurethane powder was used for the measurements. The results of measuring the storage modulus and loss tangent of the polyurethane using DMA are shown in Figure 6.

[0202] From Figure 6, it can be seen that as the temperature increases, the storage modulus of PF73PEG-H decreases more rapidly than that of PBF69PEG-H. Separately from the DMA measurements, PBF69PEG-H and PF73PEG-H were placed on a plate and observed for changes in their state as the temperature increased. No changes were observed in either sample when the temperature was increased to 40°C, but PF73PEG-H began to dissolve when the temperature was increased to 90°C, and was completely dissolved at 110-120°C. On the other hand, PBF69PEG-H did not change its state even when the temperature was increased to 120°C (see Figure 7).

[0203] The results of DMA measurements and the results of the state changes with temperature indicate that PBF69PEG-H becomes flexible while maintaining its shape above its melting point, whereas PF73PEG-H becomes so fluid that it cannot maintain its shape above its melting point. This is thought to be because the bifuran skeleton self-assembles through π-π interactions and behaves like a hard segment within the polymer.

[0204] <Example 2: Production of polyurethane having a structure represented by formula (B)> The methods for measuring the physical properties of polyurethane in the examples and comparative examples are as follows.

[0205] [Molecular weight measurement] The weight-average molecular weight and number-average molecular weight of the polyurethane were measured by size exclusion chromatography (SEC) using chloroform or DMSO as the measurement solvent.

[0206] Measurement using chloroform solvent The sample was dissolved in chloroform and filtered through a membrane filter with a pore size of 0.45 μm to prepare a measurement solution. Measurements were carried out using chloroform as the eluent at a temperature of 40°C and a flow rate of 1.0 mL / min. The measurement device used was an LC-4000 system (manufactured by JASCO Corporation) equipped with TSKgel MultiporeHXL-M (manufactured by Tosoh Corporation), TSKgel GRCHR (manufactured by Tosoh Corporation), and a guard column, TSKgel guardcolumn MP(XL) (manufactured by Tosoh Corporation). A calibration curve was prepared using TSK standard polystyrene (manufactured by Tosoh Corporation; number average molecular weight = 1.0 × 10 6 , 3.5×10 5 , 9.5×10 4 , 3.9 × 10 4 , 8.9×10 3 , 2.6×10 3 , 8.7×10 2 ) was used.

[0207] Measurement using DMSO solvent The sample was dissolved in DMSO containing 10 mM LiBr and filtered through a membrane filter with a pore size of 0.45 μm to prepare a measurement solution. Measurements were performed using DMSO containing 10 mM LiBr as the eluent at a temperature of 40°C and a flow rate of 0.5 mL / min. The measurement equipment used was TSKgel SperAWM-H (manufactured by Tosoh Corporation), Guardca A TSKgel guard column SuperAW-H (manufactured by Tosoh Corporation) and a HLC-8220 GPC (manufactured by Tosoh Corporation) equipped with a refractive index detector were used. A calibration curve was prepared using Shodex standard pullulan (manufactured by Showa Denko K.K.; number average molecular weight = 20.1 × 10 4 , 10.6×10 4 , 9.5×10 4 , 4.94×10 4 , 2.20×10 4 , 0.98×10 4 , 0.63×10 4 ) was used.

[0208] [Measurement of Nuclear Magnetic Resonance (NMR) Spectroscopy] Polyurethane 1 H NMR spectrum and 13C NMR spectra were measured using a JNM-ECS400 NMR spectrometer (manufactured by JEOL Ltd.) or a JNM-ECA600 NMR spectrometer (manufactured by JEOL Ltd.) The NMR measurement solvent was deuterated chloroform or deuterated DMSO containing tetramethylsilane as an internal standard.

[0209] [Measurement of infrared absorption (IR) spectrum] An FT / IR-4700 Fourier transform infrared spectrophotometer (manufactured by JASCO Corporation) was equipped with an ATR PRO ONE (manufactured by JASCO Corporation) and a diamond prism, and the IR spectrum of the polyurethane was measured using the single-reflection attenuated total reflection (ATR) method.

[0210] <Synthesis Example 2-1: Synthesis of bifuran acyl azide> [ka]

[0211] Bifuranicarboxylic acid (0.31 g, 1.4 mmol), triethylamine (0.43 mL, 3.0 mmol), and dehydrated NMP (2.8 mL) were added to a 50 mL recovery flask to obtain a bifuranicarboxylic acid solution. 0.70 mL of an NMP solution of diphenylphosphoryl azide (0.84 g, 3.0 mmol) was added to the bifuranicarboxylic acid solution and stirred at room temperature for 18 hours. Water (40 mL) was added to the reaction solution and stirred, and the resulting precipitate was collected by suction filtration. The precipitate was washed with water and diethyl ether and then dried to obtain bifuraniacyl azide as a brown solid (0.31 g, 81% yield).

[0212] <Examples 2-1 to 2-7> Bifurandia cyl azide (0.14 g, 0.50 mmol), a diol (0.48 mmol) shown in Table 8, and NMP (2.0 mL) were added to a 25 mL two-necked recovery flask and stirred at 100° C. for 1 hour. The reaction solution was then added dropwise to 50 mL of methanol, and the precipitate was collected by filtration to obtain polyurethane as a yellowish-brown solid. The physical properties of the resulting polyurethane are shown in Table 8.

[0213] <Comparative Example 2-1> Furan acyl azide (0.10 g, 0.50 mmol), PEG2000 (0.95 g, 0.48 mmol), and NMP (2.0 mL) were added to a 25 mL two-necked recovery flask and stirred at 100°C for 1 hour. The reaction solution was then added dropwise to 100 mL of diethyl ether, and the precipitate was collected by filtration to obtain a crude product. This crude product was dissolved in chloroform and added dropwise to cold ethanol, and the precipitate was collected by filtration to obtain polyurethane as a yellow-brown solid. The physical properties of the resulting polyurethane are shown in Table 8.

[0214] [Table 8]

[0215] PU1 1 H NMR measurement results 1 H NMR (400 MHz, DMSO-d6, 293 K): δ 10.35 (br, 2H), 6.45 (d, J = 3.2 Hz, 2H), 6.07 (d, J = 2.8 Hz, 2H), 4.11 (m, 4H), 1.68 (br, 4H) ppm.

[0216] IR measurement results for PU1 IR (Diamond-ATR): 3284 (NH), 1700 (C=O), 1547 (NH) cm -1 .

[0217] PU2 1 H NMR measurement results 1H NMR (400 MHz, DMSO-d6, 293 K): δ 10.30 (br, 2H), 6.47 (d, J = 3.6 Hz, 2H), 6.06 (d, J = 2.8 Hz, 2H), 4.06 (t, J = 6.4 Hz, 4H), 1.60 (s, 4H), 1.35 (s, 4H) ppm.

[0218] PU2 IR measurement results IR (Diamond-ATR): 3264 (NH), 1701 (C=O), 1540 (NH) cm -1 .

[0219] PU3の 1 H NMR results 1 H NMR (400 MHz, DMSO-d6, 293 K) δ10.29 (br, 2H), 6.46 (d, J = 2.8 Hz, 2H), 6.05 (d, J = 2.4 Hz, 2H), 4.05 (t, J = 6.4 Hz, 4H), 1.58 (m, 4H), 1.25 (br, 12H) ppm.

[0220] IR measurement results of PU3 IR (Diamond-ATR): 3268 (NH), 1702 (C=O), 1539 (NH) cm -1 .

[0221] PU4の 1 H NMR results 1 H NMR (400 MHz, DMSO-d6, 293 K) δ 11.01 (br, 2H), 7.27 (d, J = 8.0 Hz, 2H), 7.13 (d, J = 8.4 Hz, 2H), 6.56 (d, J = 2.8 Hz, 2H), 6.15 (s, 2H), 1.67 (s, 6H) ppm.

[0222] PU4 IR measurement results IR (Diamond-ATR): 1723 (C=O) cm -1 .

[0223] PU5の 1 H NMR results 1 H NMR (400 MHz, CDCl3, 293 K) δ 7.70 (br, 2H), 6.37 (d, J = 3.2 Hz, 2H), 6.13 (m, 2H), 4.33 (m, 4H), 3.65 (m, PEG2000) ppm.

[0224] IR measurement results of PU5 IR (Diamond-ATR): 3236 (NH), 2876 (CH), 1732 (C=O), 1552 (NH), 1092 (CO) cm -1 .

[0225] IR measurement results of PU6 IR: (Diamond-ATR) 3224 (NH), 2937, 2850, 2793 (CH), 1736 (C=O), 1550 (NH), 1101 (CO) cm -1 .

[0226] PU7の 1 H NMR results 1 H NMR (400 MHz, CDCl3, 293 K): δ 6.89 (br, 2H), 6.38 (d, J = 3.2 Hz, 2H), 6.15 (br, 2H), 4.33 (m, 4H), 3.67 (m, 4H), 3.44 (t, J = 7.0 Hz, 4H), 1.62 (m, 4H), 0.53 (m, 4H), 0.07 (s, PDMS) ppm.

[0227] PU7 IR measurement results IR (Diamond-ATR): 3258 (NH), 2960 (CH), 1739, 1715 (C=O), 1549 (NH),1256 (Si-C), 1007 (Si-O-Si) cm -1 .

[0228] PU5F 1 H NMR measurement results 1 H NMR (400 MHz, CDCl3, 293 K): δ 6.73 (br, 2H), 6.05 (br, 2H), 4.30 (m, 4H), 3.65 (m, PEG2000) ppm.

[0229] [Evaluation of Thermophysical Properties I] The thermal properties of the polyurethane and diol were evaluated by DSC and DMA measurements. The results are shown in Table 9. The storage modulus of the polyurethane measured by DMA is shown in Figure 8, the loss tangent of the polyurethane measured by DMA is shown in Figure 9, and the DSC curve of the polyurethane is shown in Figure 10.

[0230] [Table 9]

[0231] From the results of DSC measurement, no glass transition or melting point was observed for PU1 to PU4. On the other hand, in PU5, the T derived from the PEG unit c is 5℃, T m was observed at 40°C.

[0232] PEG2000, the diol used in the production of PU5, is crystalline and has a melting point of 53°C. It was found that the melting point of PEG2000 decreased when it polymerized with bifuran diisocyanate to form polyurethane. This is thought to be because the bifuran skeleton inhibits the crystal formation of polyethylene glycol units.

[0233] Similarly, in PU6, the T derived from polytetramethylene oxide unitsc -14℃, T m was observed at 20°C. PTMO2000, the diol used in the production of PU6, is crystalline and has a melting point of 24°C, but it was found that the melting point decreases when it polymerizes with bifuran diisocyanate to form polyurethane.

[0234] T of PDMS5600, the diol used in the production of PU7 m is -47°C, but the T of PU7 m This suggests that the bifuran skeleton inhibits the crystallization of the polydimethylsiloxane units.

[0235] As can be seen from Figures 8 and 9, α relaxation was observed in PU1 to PU6. In PU1, a gradual decrease in storage modulus was observed at 30°C, and a broad tan δ peak was observed at 29°C. In PU2, a decrease in storage modulus and a tan δ peak were observed at 100°C. In PU3, a decrease in storage modulus and a tan δ peak were observed at 150°C. These results indicate that the softening temperature of the polyurethane increases as the alkylene chain of the alkylene glycol diol increases.

[0236] For PU3, an increase in storage modulus and a peak in tan δ were observed at 50° C. This suggests that crystallization or crosslinking reaction of PU3 is progressing at 50° C.

[0237] In PU4, a decrease in storage modulus and a peak in tan δ were observed at 155°C.

[0238] In PU5, T m A peak in tan δ was observed at 40°C, and a tan δ peak was also observed in DMA at 43°C. On the other hand, it can be seen that the storage modulus of PU5 decreases as the temperature increases, but it does not become completely liquid and maintains a constant storage modulus. This indicates that even after the polyethylene glycol units have melted, the bifuran urethane moieties act as a physical cross-linking structure, suppressing fluidity.

[0239] In PU6, T m was observed at 20°C, but no significant peak was observed around 20°C in DMA. In PU6, a peak thought to be due to α relaxation was observed at 147°C.

[0240] For PU7, no significant changes were observed in storage modulus and tan δ.

[0241] [Evaluation of Thermal Properties II] To evaluate the influence of the bifuran skeleton, the thermal properties of PU5 and PU5F were compared by TGA, DSC, and DMA measurements. The results are shown in Table 10. The TGA curves of PU5, PU5F, and PEG2000 are shown in Figure 11, and the DSC curves of PU5, PU5F, and PEG2000 are shown in Figure 12. Furthermore, the results of measuring the storage modulus of PU5 and PU5F by DMA are shown in Figure 13, and the results of measuring the loss tangent of PU5 and PU5F by DMA are shown in Figure 14.

[0242] [Table 10]

[0243] PU5 and PU5F T d5 was higher than that of the monomer PEG 2000. This is thought to be because the thermal decomposition of PEG 2000 proceeded from the terminals, and the proportion of terminals per weight decreased due to polymerization, resulting in an increase in the decomposition temperature.

[0244] PU5 T m At 40°C, the T m was observed at 48°C, but the T m Since the T of PU5 and PU5F is 53 °C, m is considered to be the melting point due to the polyethylene glycol unit.

[0245] In the DMA of PU5 and PU5F, decreases in storage modulus E' were observed at 43°C and 49°C, respectively. The degree of decrease in storage modulus E' was smaller for PU5 than for PU5F. Furthermore, in the DMA of PU5 and PU5F, peaks in tan δ resulting from α relaxation due to softening of the main chain were observed at -30°C and -40°C, respectively.

[0246] [Evaluation of Thermal Properties III] In the evaluation of thermal properties II, the degree of decrease in storage modulus E' was thought to be due to the bifuran skeleton. Therefore, to evaluate the relationship between the difference in the degree of decrease in storage modulus E' between PU5 and PU5F and the material properties, the melting behavior was observed on a hot stage. The results are shown in Figure 15.

[0247] PU5F exhibited fluidity at 60°C, which was higher than its melting point. On the other hand, PU5 did not exhibit fluidity and maintained its shape even when heated up to 120°C. These results are consistent with the expectation that the decrease in storage modulus E' is due to the bifuran skeleton. Furthermore, these results suggest that the bifuran skeleton exhibits hard segment-like functionality through self-assembly.

Claims

1. A polyurethane having at least one structure selected from the group consisting of a structure represented by formula (A) and a structure represented by formula (B). 【Chemistry 1】 (In the formula, R １ represents a hydrocarbon group having from 1 to 12 carbon atoms which may have a substituent, or a single bond; Multiple R １ may be the same or different from each other.)

2. The polyurethane according to claim 1, having a structural unit represented by formula (A1): 【Chemistry 2】 (In the formula, R １ is R in formula (A). １ is synonymous with; R ２ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent.

3. The polyurethane according to claim 2, further comprising a structural unit represented by formula (A2): 【Transformation 3】 (In the formula, R ２ is R in formula (A1). ２ is synonymous with; R ３ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R ａ１ (OR ａ１ ) n１ a group represented by -*, *-R ａ２ (Si(R ａ３ ) ２ O) ｎ２ Si(R ａ３ ) ２ R ａ２ -*, *-((CH ２ ) ｘ OCOR ａ４ COO) ｎ３ (CH ２ ) ｘ -*, or *-((C(R ａ６ ) ２ ) ｚ COO) ｎ４ R ａ５ (OCO(C(R ａ６ ) ２ ) ｚ ) ｎ４ - represents a group represented by *; R ａ１ represents an alkylene group having 1 to 6 carbon atoms; R ａ２ is -CH ２ - represents an alkylene group having 1 to 10 carbon atoms which may be substituted with -O- or a single bond; R ａ３ represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R ａ４ is a phenylene group or *-(CH ２ ) ｙ - represents a group represented by *; R ａ５ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent; R ａ６ represents a hydrogen atom or a methyl group; Multiple R ａ１ may be the same or different from each other; Multiple R ａ２ may be the same or different from each other; Multiple R ａ３ may be the same or different from each other; Multiple R ａ４ may be the same or different from each other; Multiple R ａ６ may be the same or different from each other; n1 represents an integer of 1 or more and 100 or less; n2 represents an integer of 1 or more and 100 or less; n3 represents an integer of 2 or more; n4 represents an integer of 1 or more and 1,000 or less; Multiple n4s may be the same or different from each other; x represents an integer of 1 or more; y represents an integer of 0 or greater; z represents an integer of 1 or more; Multiple x's may be the same or different from each other; Multiple y's may be the same or different from each other; Multiple z's may be the same or different.

4. The polyurethane according to claim 1, having a structural unit represented by formula (B1): 【Chemistry 4】 (In the formula, R ４ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R ｂ１ (OR ｂ１ ) ｍ１ a group represented by -*, *-R ｂ２ (Si(R ｂ３ ) ２ O) ｍ２ Si(R ｂ３ ) ２ R ｂ２ -*, *-((CH ２ ) ｐ OCOR ｂ４ COO) ｍ３ (CH ２ ) ｐ -*, or *-((C(R ｂ６ ) ２ ) ｒ COO) ｍ４ R ｂ５ (OCO(C(R ｂ６ ) ２ ) ｒ ) ｍ４ - represents a group represented by *; R ｂ１ represents an alkylene group having 1 to 6 carbon atoms; R ｂ２ is -CH ２ - represents an alkylene group having 1 to 10 carbon atoms which may be substituted with -O- or a single bond; R ｂ３ represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R ｂ４ is a phenylene group or *-(CH ２ ) ｑ - represents a group represented by *; R ｂ５ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent; R ｂ６ represents a hydrogen atom or a methyl group; Multiple R ｂ１ may be the same or different from each other; Multiple R ｂ２ may be the same or different from each other; Multiple R ｂ３ may be the same or different from each other; Multiple R ｂ４ may be the same or different from each other; Multiple R ｂ６ may be the same or different from each other; m1 represents an integer of 1 or more and 100 or less; m2 represents an integer of 1 or more and 100 or less; m3 represents an integer of 2 or more; m4 represents an integer of 1 or more and 1,000 or less; Multiple m4 may be the same or different from each other; p represents an integer of 1 or more; q represents an integer of 0 or more; r represents an integer of 1 or more; Multiple p's may be the same or different from each other; Multiple q's may be the same or different; Multiple r's may be the same or different.

5. The polyurethane according to claim 4, further comprising a structural unit represented by formula (B2): 【Transformation 5】 (In the formula, R ４ is R in formula (B1). ４ is synonymous with; R ５ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent.

6. A plastic molded article comprising the polyurethane according to any one of claims 1 to 5.

7. The plastic molded article according to claim 6, which is a fiber, a film, or a foam.

8. A polyurethane composition comprising the polyurethane according to any one of claims 1 to 5.

9. The polyurethane composition according to claim 8, which is used in a paint, an adhesive, a pressure-sensitive adhesive, or an ink.

10. A method for producing a polyurethane, comprising a reaction step of reacting a diol with a diisocyanate, wherein one or both of the following X1 and X2 are satisfied: X1: The diol includes a diol represented by formula (a1). X2: The diisocyanate includes a diisocyanate represented by formula (b2). 【Transformation 6】 (In the formula, R １ represents a hydrocarbon group having from 1 to 12 carbon atoms which may have a substituent, or a single bond; Multiple R １ may be the same or different from each other.)

11. Fills X1, The method for producing a polyurethane according to claim 10, wherein the diisocyanate includes a diisocyanate represented by formula (a2): 【Transformation 7】 (In the formula, R ２ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent.

12. The method for producing a polyurethane according to claim 11, wherein the diol further comprises a diol represented by formula (a3): 【Transformation 8】 (In the formula, R ３ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R ａ１ (OR ａ１ ) n１ a group represented by -*, *-R ａ２ (Si(R ａ３ ) ２ O) ｎ２ Si(R ａ３ ) ２ R ａ２ -*, *-((CH ２ ) ｘ OCOR ａ４ COO) ｎ３ (CH ２ ) ｘ -*, or *-((C(R ａ６ ) ２ ) ｚ COO) ｎ４ R ａ５ (OCO(C(R ａ６ ) ２ ) ｚ ) ｎ４ - represents a group represented by *; R ａ１ represents an alkylene group having 1 to 6 carbon atoms; R ａ２ is -CH ２ - represents an alkylene group having 1 to 10 carbon atoms which may be substituted with -O- or a single bond; R ａ３ represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R ａ４ is a phenylene group or *-(CH ２ ) ｙ - represents a group represented by *; R ａ５ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent; R ａ６ represents a hydrogen atom or a methyl group; Multiple R ａ１ may be the same or different from each other; Multiple R ａ２ may be the same or different from each other; Multiple R ａ３ may be the same or different from each other; Multiple R ａ４ may be the same or different from each other; Multiple R ａ６ may be the same or different from each other; n1 represents an integer of 1 or more and 100 or less; n2 represents an integer of 1 or more and 100 or less; n3 represents an integer of 2 or more; n4 represents an integer of 1 or more and 1,000 or less; Multiple n4s may be the same or different from each other; x represents an integer of 1 or more; y represents an integer of 0 or greater; z represents an integer of 1 or more; Multiple x's may be the same or different from each other; Multiple y's may be the same or different from each other; Multiple z's may be the same or different.

13. Fill X2, The method for producing a polyurethane according to claim 10 , wherein the diol comprises a diol represented by formula (b1): 【Chemistry 9】 (In the formula, R ４ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent, *-R ｂ１ (OR ｂ１ ) ｍ１ a group represented by -*, *-R ｂ２ (Si(R ｂ３ ) ２ O) ｍ２ Si(R ｂ３ ) ２ R ｂ２ -*, *-((CH ２ ) ｐ OCOR ｂ４ COO) ｍ３ (CH ２ ) ｐ -*, or *-((C(R ｂ６ ) ２ ) ｒ COO) ｍ４ R ｂ５ (OCO(C (R ｂ６ ) ２ ) ｒ ) ｍ４ - represents a group represented by *; R ｂ１ represents an alkylene group having 1 to 6 carbon atoms; R ｂ２ is -CH ２ - represents an alkylene group having 1 to 10 carbon atoms which may be substituted with -O- or a single bond; R ｂ３ represents a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent; R ｂ４ is a phenylene group or *-(CH ２ ) ｑ - represents a group represented by *; R ｂ５ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent; R ｂ６ represents a hydrogen atom or a methyl group; Multiple R ｂ１ may be the same or different from each other; Multiple R ｂ２ may be the same or different from each other; Multiple R ｂ３ may be the same or different from each other; Multiple R ｂ４ may be the same or different from each other; Multiple R ｂ６ may be the same or different from each other; m1 represents an integer of 1 or more and 100 or less; m2 represents an integer of 1 or more and 100 or less; m3 represents an integer of 2 or more; m4 represents an integer of 1 or more and 1,000 or less; Multiple m4 may be the same or different from each other; p represents an integer of 1 or more; q represents an integer of 0 or more; r represents an integer of 1 or more; Multiple p's may be the same or different from each other; Multiple q's may be the same or different; Multiple r's may be the same or different.

14. The method for producing a polyurethane according to claim 13, wherein the diisocyanate further comprises a diisocyanate represented by formula (b3): 【Chemistry 10】 (In the formula, R ５ represents a hydrocarbon group having 1 to 32 carbon atoms which may have a substituent.

15. an azidation step of azidizing a dicarboxylic acid represented by formula (b2-1) to obtain a diacyl azide represented by formula (b2-2); a Curtius rearrangement step of performing a Curtius rearrangement of the acyl azide represented by formula (b2-2) to obtain a diisocyanate represented by formula (b2); A method for producing a diisocyanate having a bifuran skeleton, comprising: 【Chemistry 11】

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