Method for producing polyhydroxyurethane having ABAC type monomer sequence

Abstract

To provide a process for producing a novel polyhydroxyurethane that can be produced by a simple procedure and whose monomer sequence is controlled.SOLUTION: The process for producing polyhydroxyurethane is a process for producing a polyhydroxyurethane that has an ABAC type monomer sequence, and comprises a step in which a bifunctional cyclic carbonate (A) having a spiro structure and a diamine (B) are reacted, followed by reacting the obtained reaction product and a diamine (C) to yield a polyhydroxyurethane, and in which the bifunctional cyclic carbonate (A) is 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione, and the diamine (B) and the diamine (C) comprises different structure.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing polyhydroxyurethane having an ABAC type monomer sequence. [Background technology]

[0002] Biopolymers such as proteins and DNA exhibit advanced functions by forming unique higher-order structures due to their primary structure (monomer sequence). On the other hand, except for alternating copolymers consisting of two types of monomers, synthetic polymers obtained by copolymerization of three or more types of monomers are difficult to control the monomer sequence during polymerization, so examples of synthesizing polymers with regular monomer sequences are limited to methods that combine asymmetric monomers or different reactions (addition reaction + condensation reaction, etc.) (see, for example, Non-Patent Documents 1 to 3, etc.). In addition, such polymers with controlled monomer sequences are expected to exhibit properties different from polymers with randomly arranged functional groups, since two or more types of functional groups can be introduced along the polymer main chain at specific intervals and sequences.

[0003] Meanwhile, the inventors have recently developed a method for synthesizing a bifunctional cyclic carbonate having a spiro structure (2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione; a compound represented by the following formula (I); hereinafter, sometimes referred to as "compound (I)") from inexpensive polyols pentaerythritol (PE) and diphenyl carbonate (DPC) using a catalyst-free and simple purification procedure.

[0004] [ka] [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Ueda M., “Sequence control in one-step condensation polymerization.”, Prog. Polym. Sci., Vol. 24, pp. 699-730, 1999. [Non-Patent Document 2] Lutz JF et al., “Sequence-Controlled Polymers.”, Science, Vol. 341, Issue 6146, 1238149, 2013, DOI: 10.1126 / science.1238149. [Non-Patent Document 3] Qu C et al., “Recent developments in the synthesis of sequence controlled polymers.”, Vol. 58, No. 11, pp. 1651-1662, 2015. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a novel method for producing polyhydroxyurethane, which can be produced by a simple procedure and has a controlled monomer sequence. [Means for solving the problem]

[0007] That is, the present invention includes the following aspects. (1) comprising a step of reacting a bifunctional cyclic carbonate (A) having a spiro structure with a diamine (B) and then reacting the resulting reaction product with a diamine (C) to obtain a polyhydroxyurethane, The bifunctional cyclic carbonate (A) is 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione, The diamine (B) and the diamine (C) have different structures. and the amount of the diamine (B) added is 0.4 molar equivalents or more and 0.6 molar equivalents or less relative to 1 molar equivalent of the bifunctional cyclic carbonate (A). A method for producing polyhydroxyurethane having an ABAC monomer sequence 。 (2 The amount of the diamine (B) added is 0.5 molar equivalents relative to 1 molar equivalent of the difunctional cyclic carbonate (A). ) The manufacturing method described above. ( 3 In the above step, the reaction is carried out at 5° C. or lower. (1) Or (2) The manufacturing method described in Effect of the Invention

[0008] According to the production method of the above aspect, it is possible to provide a novel method for producing polyhydroxyurethane, which can be produced by a simple procedure and has a controlled monomer sequence. [Brief description of the drawings]

[0009] [Figure 1] (a) 1H NMR spectrum of the reaction solution of 1-hexylamine and compound (I) in Example 1. (b) 1H NMR spectrum of the reaction solution of 1-hexylamine and intermediate 2a in Example 1. [Diagram 2] 1 is a graph showing the rates of each second-order reaction estimated by 1H NMR measurement in Example 1. [Diagram 3] 1H NMR spectrum of dihydroxyurethane 3d in Example 2. [Figure 4] (a) 1H NMR spectrum of a solution obtained by reacting p-xylylenediamine and compound (I) at 0° C. for 7 hours in Example 3. (b) 1H NMR spectrum of a solution obtained by reacting 1,6-diaminohexane and intermediate 6a at 0° C. for 40 hours in Example 3. [Diagram 5] 1H NMR spectra of poly-(Xyl / C6) in Example 3 and, for comparison, polyhydroxyurethane (poly-Xyl and poly-C6) obtained by polyaddition of compound (I) and p-xylylenediamine or 1,6-diaminohexane. [Figure 6]1H NMR spectra of poly-(Xyl / C6) in Example 3, and poly-Xyl, poly-C6, and poly-(Xyl-ran-C6) synthesized for comparison. [Figure 7] FIG. 1 is a schematic diagram showing non-covalent interactions between adjacent polymers in polyhydroxyurethane. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment for carrying out the present invention (hereinafter, abbreviated as "present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and can be carried out in various modifications within the scope of the gist of the present invention.

[0011] <Method of producing polyhydroxyurethane> The method for producing polyhydroxyurethane of this embodiment (hereinafter sometimes simply referred to as the "production method of this embodiment") includes a step of reacting a bifunctional cyclic carbonate (A) having a spiro structure with a diamine (B), and then reacting the resulting reaction product with a diamine (C) to obtain polyhydroxyurethane (hereinafter sometimes referred to as the "reaction step"). The bifunctional cyclic carbonate (A) is 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione. The diamine (B) and the diamine (C) are diamine compounds having different structures.

[0012] The polyhydroxyurethane obtained by the production method of this embodiment is a polyhydroxyurethane having an ABAC type monomer sequence, i.e., a polyhydroxyurethane having a repeating sequence in which a constitutional unit derived from a bifunctional cyclic carbonate (A), a constitutional unit derived from a diamine (B), a constitutional unit derived from a bifunctional cyclic carbonate (A), and a constitutional unit derived from a diamine (C) are arranged in this order.

[0013] The inventors have revealed that a difunctional cyclic carbonate, 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione (compound (I)), undergoes a ring-opening reaction with 2 molar equivalents of an amine per molar equivalent of compound (I) to produce a dihydroxyurethane via a cyclic carbonate intermediate having one hydroxy group and one urethane group (see the reaction scheme below. In the reaction scheme, R 1 and R 2 are each independently a monovalent hydrocarbon group, R 1 and R 2 are different).

[0014] [ka]

[0015] In the above reaction formula, as shown in the examples described later, the ring strain of the cyclic carbonate moiety of the intermediate is greatly relaxed compared to compound (I) in which two cyclic structures are linked. That is, the ring strain of compound (I) having a spiro structure is greater than that of the intermediate, and the reactivity of compound (I) with amine is higher than that of the intermediate. Since this difference in reactivity is sufficiently large, an intermediate is selectively generated by reacting 1 molar equivalent of compound (I) with 1 molar equivalent of amine, and after all of compound (I) is consumed, a dihydroxyurethane having different amine residues can be efficiently synthesized by adding 1 molar equivalent of a different amine to 1 molar equivalent of compound (I) and reacting it with the intermediate. Furthermore, by making the most of this feature, as shown in the examples described later, it has been found that it is possible to synthesize a sequence-controlled polymer from a monomer having a symmetric structure, which has been difficult to synthesize by polyaddition reaction until now, that is, a polyhydroxyurethane having an ABAC type monomer sequence that has never been reported before, in which two different types of diamine residues are alternately arranged via dihydroxyurethane units, and the present invention has been completed.

[0016] Next, the steps constituting the manufacturing method of this embodiment will be described in detail below.

[0017] [Reaction process] In the reaction step, as shown in the reaction formula below, diamine (B) is reacted with compound (I) (first-stage reaction), and after it is confirmed that diamine (B) and compound (I) are consumed, diamine (C) is added, and the reaction product (reaction intermediate) of diamine (B) and compound (I) is reacted with diamine (C) (second-stage reaction) to obtain polyhydroxyurethane. In the production method of this embodiment, as shown in the examples described later, the reaction of diamine (B) with compound (I) proceeds with high efficiency and the generation of by-products is extremely low, so that after the consumption of diamine (B) and compound (I) is confirmed, the reaction with diamine (C) is proceeded, and the reaction between diamine (B) and compound (I) (first-stage reaction) and the reaction product (reaction intermediate) of diamine (B) and compound (I) and diamine (C) (second-stage reaction) can be carried out in the same reaction vessel. In addition, in the first-stage reaction, the fact that the diamine (B) and the compound (I) have been consumed can be confirmed by using a known method such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), or infrared spectroscopy (IR). The reaction shown in the following reaction scheme for obtaining polyhydroxyurethane is a known ring-opening polyaddition reaction.

[0018] [ka]

[0019] In the above reaction formula, R 1 and R 2 each independently represents an alkylene group, an aralkylene group, or -R 11 -Ar 11 -R 12 - is a group represented by Ar 11 is a divalent aromatic hydrocarbon group, and R 11 and R 12 R is independently an alkylene group having 1 to 20 carbon atoms. 1 and R 2 are different. n is an integer of 1 or greater.

[0020] (Difunctional cyclic carbonate (A)) The bifunctional cyclic carbonate (A) is 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione (compound (I)). The CAS number of compound (I) is 84056-48-4. Compound (I) may be a commercially available product or may be synthesized by a known method, but it is preferable that compound (I) is obtained by the production method shown below, since compound (I) can be obtained easily and in good yield.

[0021] Examples of the method for producing compound (I) include a method including a step of reacting pentaerythritol (PE) with a diaryl carbonate to obtain compound (I) (hereinafter, sometimes referred to as a "synthetic step of compound (I)") as shown in the following reaction formula. This reaction for obtaining compound (I) is a known intramolecular cyclization reaction.

[0022] [ka]

[0023] (1) Pentaerythritol (PE) Pentaerythritol (PE) is a compound having the structure shown in the above reaction formula. PE can be synthesized, for example, by condensing acetaldehyde and formaldehyde in a basic environment. Commercially available PE may also be used. The CAS number of PE is 115-77-5.

[0024] (2) Diaryl carbonate Examples of diaryl carbonates include a compound represented by the following general formula (III) (hereinafter, sometimes referred to as "compound (III)").

[0025] [ka]

[0026] In general formula (III), Ar 31 and Ar 32 are each independently a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0027] Ar 31 and Ar 32 is an aromatic hydrocarbon group having 6 to 20 carbon atoms, preferably an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms. The aromatic hydrocarbon group may have a substituent. Examples of the substituent in the aromatic hydrocarbon group include an alkyl group, an alkoxy group, a dialkylamino group, a halogen group, a nitro group, a trifluoromethyl group, and a cyano group. Such an Ar 31 and Ar 32 Specifically, examples of the phenyl group, methylphenyl group (each isomer), ethylphenyl group (each isomer), propylphenyl group (each isomer), butylphenyl group (each isomer), pentylphenyl group (each isomer), hexylphenyl group (each isomer), dimethylphenyl group (each isomer), methylethylphenyl group (each isomer), methylpropylphenyl group (each isomer), methylbutylphenyl group (each isomer), methylpentylphenyl group (each isomer), diethylphenyl group (each isomer), ethylpropylphenyl group (each isomer), ethyl Examples of such groups include a butylphenyl group (each isomer), a dipropylphenyl group (each isomer), a trimethylphenyl group (each isomer), a triethylphenyl group (each isomer), a naphthyl group (each isomer), a methoxyphenyl group, a dimethoxyphenyl group, a trimethoxyphenyl group, a dimethylaminophenyl group, a chlorophenyl group, a dichlorophenyl group, a trichlorophenyl group, a fluorophenyl group, a difluorophenyl group, a trifluorophenyl group, a perfluorophenyl group, a nitrophenyl group, a dinitrophenyl group, and a trinitrophenyl group. Among these, Ar 31 and Ar 32 As the alkyl group, a phenyl group is preferable. Ar 31 and Ar 32 may be the same or different, but from the viewpoint of ease of production, it is preferable that they are the same.

[0028] Preferred diaryl carbonates include Ar 31 and Ar 32 is an aromatic hydrocarbon group having 6 to 10 carbon atoms. Specific examples of such diaryl carbonates include diphenyl carbonate, di(methylphenyl) carbonate (each isomer), di(diethylphenyl) carbonate (each isomer), and di(methylethylphenyl) carbonate (each isomer). Note that these compounds are merely examples of preferred diaryl carbonates, and preferred diaryl carbonates are not limited to these. Furthermore, these diaryl carbonates may be used alone or in combination of two or more. Among these, diphenyl carbonate is particularly preferred as the diaryl carbonate.

[0029] Known methods can be used as a method for producing diaryl carbonate. Among them, a method described in WO 2009 / 139061 (Reference 1) is preferred, which involves reacting an organotin compound having a tin-oxygen-carbon bond with carbon dioxide to produce an aliphatic carbonate, and then producing an aromatic carbonate (i.e., diaryl carbonate) from the aliphatic carbonate and an aromatic hydroxy compound. The diaryl carbonate can be produced, for example, by using the production apparatus described in WO 2009 / 139061 (Reference 1). Commercially available diaryl carbonate may also be used.

[0030] The synthesis step of compound (I) can be carried out in the presence or absence of a solvent. The solvent may be any solvent that can dissolve PE, and is preferably a highly polar solvent that does not have a hydroxyl group. Specific examples of such a solvent include the following:

[0031] (1) Ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone; (2) Nitriles such as acetonitrile, butyronitrile, and caprylnitrile; (3) Esters such as methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, diamyl phthalate, dibutyl fumarate, dimethyl maleate, diethyl maleate, and dibutyl maleate; (4) Ethers such as furan, tetrahydrofuran, propyl oxide, dioxane, dibenzyl ether, and diphenyl ether; (5) Glycol ether esters such as ethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, cyclohexanol acetate, propylene glycol diacetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, and 1,6-hexanediol diacetate; (6) Phosphite esters such as triphenyl phosphite; (7) Sulfur compounds such as dimethyl sulfide, thiophene, and carbon disulfide; (8) Halogenated hydrocarbons, such as methyl chloride, ethyl chloride, dichloropropane, dichloroethylene, trichloroethylene, tetrachloroethylene, pentachloroethane, chloroform, methyl bromide, ethyl bromide, methyl iodide, and ethyl iodide; (9) N,N-dimethylformamide (DMF), N,N-dimethylacetamide, N,N-dimethylpropionamide, 1-methyl-2-pyrrolidone, 1-ethyl-2-pyrrolidone, 1,5-dimethyl-2-pyrrolidone; (10) Pyrrolidines such as 1-acetylpyrrolidine; (11) Ureas such as 1,3-dimethyl-2-imidazolidinone; (12) Sulfoxide compounds such as dimethyl sulfoxide (DMSO), diethyl sulfoxide, dipropyl sulfoxide, dibutyl sulfoxide, diphenyl sulfoxide, methyl ethyl sulfoxide, methyl propyl sulfoxide, methyl butyl sulfoxide, and methyl phenyl sulfoxide.

[0032] These solvents may be used alone or in combination of two or more. When two or more types are used in combination, the combination and ratio thereof can be selected arbitrarily.

[0033] In the synthesis step of compound (I), for example, the reaction is preferably carried out under an inert gas atmosphere. Examples of the inert gas include argon gas, helium gas, and nitrogen gas.

[0034] In the synthesis process of compound (I), the amount of PE used, i.e., the concentration of PE in the reaction solution, is preferably from 10 mmol / L to 100 mmol / L, more preferably from 10 mmol / L to 80 mmol / L, even more preferably from 10 mmol / L to 60 mmol / L, particularly preferably from 10 mmol / L to 40 mmol / L, and most preferably from 10 mmol / L to 30 mmol / L, relative to the total volume of the reaction solution. When the concentration of PE is equal to or higher than the lower limit, the PE can be reacted more thoroughly with the diaryl carbonate. On the other hand, when the concentration of PE is equal to or lower than the upper limit, the carbonation of PE can be preferentially caused intramolecularly rather than intermolecularly, and the yield (selectivity) of compound (I) can be further improved.

[0035] In the synthesis process of compound (I), the amount of diaryl carbonate used can be expressed as a molar ratio of diaryl carbonate to PE. The molar ratio of diaryl carbonate to PE is preferably 2 / 1 or more and 10 / 1 or less, more preferably 4 / 1 or more and 10 / 1 or less. When the molar ratio of diaryl carbonate to PE is equal to or greater than the lower limit, carbonation of PE can occur preferentially intramolecularly rather than intermolecularly, and the yield (selectivity) of compound (I) can be improved. When the molar ratio of diaryl carbonate to PE is equal to or less than the upper limit, the abundance ratio of diaryl carbonate can be prevented from becoming excessive, and compound (I) can be produced more efficiently while suppressing production costs.

[0036] In the synthesis process of compound (I), the reaction temperature can be from 20°C to 100°C, preferably from 40°C to 100°C, more preferably from 50°C to 100°C, and even more preferably from 75°C to 100°C. By keeping the reaction temperature at or above the lower limit, the carbonation of PE can be preferentially caused intramolecularly rather than intermolecularly, and the yield (selectivity) of compound (I) can be improved. On the other hand, by keeping the reaction temperature at or below the upper limit, the application of excess heat can be suppressed, and compound (I) can be produced more efficiently while suppressing production costs.

[0037] The reaction time can be, for example, from 1 hour to 24 hours, and can be from 6 hours to 18 hours.

[0038] The method for producing compound (I) may further include a step of purifying compound (I) after the step of synthesizing compound (I), i.e., after completion of the reaction.

[0039] In the purification step, post-treatment is carried out as necessary by a known method to extract compound (I). Specifically, post-treatment operations such as filtration, washing, extraction, pH adjustment, dehydration, and concentration are carried out individually or in combination as necessary, and compound (I) is roughly purified by concentration, crystallization, reprecipitation, column chromatography, etc.

[0040] In order to increase the purity of the above-mentioned roughly purified compound (I), it is preferable to carry out, as necessary, one or more of the following operations, such as crystallization, reprecipitation, column chromatography, extraction, and stirring and washing of the crystals with a solvent, either alone or in combination.

[0041] In the method for producing compound (I), after the synthesis step of compound (I), the compound may be used in the production method of polyhydroxyurethane described below without carrying out a purification step. However, from the viewpoint of improving the yield of polyhydroxyurethane, it is preferable to carry out a purification step of compound (I).

[0042] The structure of Compound (I) can be confirmed by known techniques such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and infrared spectroscopy (IR).

[0043] (Diamine) The diamine (B) and the diamine (C) are compounds represented by the following general formula (B) and (C), respectively.

[0044] [ka]

[0045] In the formula, R 1 and R 2 each independently represents an alkylene group, an aralkylene group, or -R 11 -Ar 11 -R 12 - is a group represented by Ar 11 is a divalent aromatic hydrocarbon group, and R 11 and R 12 R is independently an alkylene group having 1 to 20 carbon atoms. 1 and R 2 is different.

[0046] R 1 and R 2 The alkylene group in is preferably a linear alkylene group having 2 to 20 carbon atoms, and specific examples thereof include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tetradecylene group, a hexadecylene group, an octadecylene group, a nonadecylene group, and an icosylene group. 1 and R 2 The alkylene group in is preferably a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, or a decylene group, and more preferably a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, or an octylene group.

[0047] R1 and R 2 The aralkylene group in is preferably an aralkylene group having 3 to 20 carbon atoms, and specific examples thereof include a benzylene group, a phenethylene group, a phenylbutylene group, a naphthylmethylene group, and a naphthylethylene group. 1 and R 2 The aralkylene group in is preferably a benzylene group or a phenethylene group.

[0048] R 1 and R 2 -R in 11 -Ar 11 -R 12 In the group represented by -, R 11 and R 12 may be the same or different, but is preferably the same. R 11 and R 12 Examples of the alkylene group having 1 to 20 carbon atoms in R include a methylene group and the same as those exemplified in the alkylene group in X. 1 and R 2 As the alkylene group having 1 to 20 carbon atoms in the formula (I), a methylene group or an ethylene group is preferable.

[0049] R 1 and R 2 -R in 11 -Ar 11 -R 12 Specific examples of the group represented by - include a group represented by -CH2-Ph-CH2- (Ph is a phenylene group, the same applies below), and a group represented by -CH2CH2-Ph-CH2CH2-. Among these, R 1 and R 2 -R in 11 -Ar 11 -R 12 As the group represented by -, a group represented by -CH2-Ph-CH2- is preferable.

[0050] Examples of preferred diamines include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, p-xylylenediamine, etc. Among them, 1,3-diaminopropane, 1,6-diaminohexane, or p-xylylenediamine is preferred as the diamine.

[0051] Also, an aralkylene group or -R 11 -Ar 11 -R 12 Diamines having aromatic rings such as a group represented by - tend to be less reactive with compound (I) than diamines having alkylene groups. Therefore, when a diamine having an aromatic ring and a diamine having an alkylene group are used in combination as diamine (B) and diamine (C), it is preferable to use a diamine having an aromatic ring as diamine (B) and then use a diamine having an alkylene group as diamine (C). As shown in the examples described later, compound (I) is extremely more reactive than the reaction product (reaction intermediate) of compound (I) and diamine, so that a polyhydroxyurethane having an ABAC type monomer sequence can be obtained more efficiently by reacting a diamine having an aromatic ring with compound (I) and then reacting the reaction intermediate with a diamine having an alkylene group.

[0052] The reaction step can be carried out in the presence or absence of a solvent. Examples of the solvent include the same solvents as those exemplified in the above-mentioned method for producing compound (I). The solvent may be used alone or in combination of two or more. When two or more types are used in combination, the combination and ratio thereof can be selected arbitrarily. Among these, the solvent is preferably DMF, DMSO, or a mixed solvent thereof.

[0053] The reaction step can be carried out without the use of a catalyst.

[0054] The reaction step is preferably carried out, for example, under an inert gas atmosphere. Examples of the inert gas include argon gas, helium gas, and nitrogen gas.

[0055] In the reaction step, the amount of diamine (B) used is preferably 0.3 molar equivalents or more and 0.7 molar equivalents or less, more preferably 0.4 molar equivalents or more and 0.6 molar equivalents or less, and even more preferably 0.5 molar equivalents, relative to 1 molar equivalent of compound (I), from the viewpoint of efficiently synthesizing a reaction intermediate consisting of an ABA type monomer sequence.

[0056] In the reaction step, the amount of diamine (C) used is preferably 0.3 molar equivalents or more and 0.7 molar equivalents or less, more preferably 0.4 molar equivalents or more and 0.6 molar equivalents or less, and even more preferably 0.5 molar equivalents, relative to 1 molar equivalent of compound (I), from the viewpoint of efficiently synthesizing polyhydroxyurethane having an ABAC type monomer sequence.

[0057] In the reaction step, in the latter stage of the reaction, the molar concentration of the amino group at the polymer chain end of the polyhydroxyurethane produced is significantly lower than the molar concentration of the hydroxy group end produced. Therefore, there is a risk that the compound (I) reacts with the hydroxy group instead of the amino group, crosslinking the polymer chain, and gelation of the polyhydroxyurethane occurs. Therefore, in order to suppress the gelation of the polyhydroxyurethane, it is preferable to add diamine (C) in an amount of 0.05 molar equivalent or more and 0.3 molar equivalent or less, preferably 0.07 molar equivalent or more and 0.2 molar equivalent or less, more preferably 0.09 molar equivalent or more and 0.15 molar equivalent or less, and even more preferably 0.1 molar equivalent, in the middle of the reaction, for example, 24 hours, 36 hours, and 40 hours after the start of the reaction, so that the amount of diamine (C) is 0.05 molar equivalent or more and 0.3 molar equivalent or less, preferably 0.07 molar equivalent or more and 0.2 molar equivalent or less, more preferably 0.09 molar equivalent or more and 0.15 molar equivalent or less, and even more preferably 0.1 molar equivalent, relative to 1 molar equivalent of the compound (I). This can prevent the formation of a crosslinked structure in the polyhydroxyurethane, and can effectively suppress the gelation of the produced polyhydroxyurethane. When diamine (C) is added during the reaction, the above-mentioned amount of diamine (C) can be added in addition to the amount of diamine (C) used at the start of the reaction (for example, about 0.3 molar equivalents or more and 0.7 molar equivalents or less per molar equivalent of compound (I)). When diamine (C) is added during the reaction, the reaction can be carried out at a temperature of, for example, 50° C. or higher and 100° C. or lower, preferably 60° C. or higher and 90° C. or lower, more preferably 70° C. or higher and 85° C. or lower, and even more preferably 80° C., in order to completely consume unreacted reaction intermediates and linear carbonates produced by side reactions.

[0058] In the reaction step, the reaction temperature is preferably 5°C or lower, more preferably 0°C. By keeping the reaction temperature at or below the upper limit, the production of polyhydroxyurethane having a branched structure can be more effectively suppressed, and the yield of polyhydroxyurethane having a linear structure can be further improved. On the other hand, the lower limit of the reaction temperature is not particularly limited, and can be, for example, 0°C.

[0059] In the reaction step, the reaction time between the diamine (B) and the compound (I) can be, for example, 1 hour or more and 24 hours or less, 2 hours or more and 12 hours or less, or 3 hours or more and 10 hours or less. On the other hand, the reaction time between the reaction intermediate and diamine (C) is slower than that between the diamine (B) and compound (I) as shown in the examples described later, and therefore can be, for example, 24 hours or more and 100 hours or less, 36 hours or more and 80 hours or less, or 40 hours or more and 75 hours or less.

[0060] [Other processes] The production method of this embodiment may further include a step of purifying the polyhydroxyurethane after the reaction step, i.e., after completion of the reaction.

[0061] In the purification step, polyhydroxyurethane is extracted by performing post-treatment according to a known method as necessary. Specifically, post-treatment operations such as filtration, washing, extraction, pH adjustment, dehydration, and concentration are performed alone or in combination as necessary, and polyhydroxyurethane is roughly purified by concentration, crystallization, reprecipitation, column chromatography, etc.

[0062] In order to increase the purity of the above-mentioned roughly refined polyhydroxyurethane, it is preferable to carry out, as necessary, one or more of the following operations, such as crystallization, reprecipitation, column chromatography, extraction, and stirring and washing of the crystals with a solvent, either alone or in combination.

[0063] In the production method of this embodiment, a purification step does not have to be carried out after the reaction step. However, from the viewpoint of the storage stability of polyhydroxyurethane and the use of polyhydroxyurethane in a variety of applications, it is preferable to carry out a purification step of polyhydroxyurethane.

[0064] The structure of the polyhydroxyurethane can be confirmed by known techniques such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), and infrared spectroscopy (IR).

[0065] <Uses of polyhydroxyurethane> The polyhydroxyurethane obtained by the production method of this embodiment is suitable for use as an industrial material, such as a molding material or a binder for paint. EXAMPLES

[0066] The present embodiment will be described in more detail below with reference to specific examples and comparative examples, but the present embodiment is not limited to the following examples and comparative examples as long as the gist of the present embodiment is not exceeded. Various analyses performed in the examples and comparative examples described below were measured by the following methods.

[0067] [Example 1] (Examination of the reactivity of compound (I) and the reaction intermediate with amines) First, whether an intermediate (compound 2a in the following reaction scheme, hereinafter sometimes referred to as "intermediate 2a") is selectively produced by the reaction of 1 molar equivalent of compound (I) with 1 molar equivalent of 1-hexylamine, 1 The reaction was confirmed by H NMR measurement, and the second-order reaction rate constant (k I-2a The reaction between compound (I) and 1-hexylamine is shown below.

[0068] [ka]

[0069] Specifically, 1-hexylamine (2.69 g, 26.6 mmol) was first added to a 10 mL measuring flask, and DMF (ultra-dehydrated) was then added to prepare 10 mL of DMF solution (hereinafter, sometimes referred to as "Solution I-1"). Compound (I) (250 mg, 1.33 mmol) was completely dissolved in DMF (9.5 mL), and then CH2Cl2 (86 μL, 1.31 mmol) was added as an internal standard and cooled to 0°C. 500 μL of Solution I-1 (containing 1.33 mmol of 1-hexylamine) was then added to the flask, and the consumption rate of Compound (I) was measured. 1The reaction was followed by H NMR measurement (see Figure 1(a)), and the second-order reaction rate constant (k I-2a The second-order reaction rate constant (k I-2a ) is shown in Figure 2.

[0070] As shown in Figure 1(a), intermediate 2a was obtained as the main product, and small amounts of by-products were also confirmed, including dihydroxyurethane 3c and a chain carbonate produced by the reaction of the OH group of intermediate 2a with unreacted compound (I). The molar ratio of these products (intermediate 2a:dihydroxyurethane 3c:other by-products) was approximately 88.2:1.9:9.9. This indicates that the reactivity of compound (I) with amines is clearly higher than that of intermediate 2a.

[0071] Next, 1 molar equivalent of 1-hexylamine was added to 1 molar equivalent of intermediate 2a generated in situ, and the second-order reaction rate constant (k 2a-3c ) was sought. Specifically, first, compound (I) (250 mg, 1.33 mmol) was completely dissolved in DMF (9.5 mL), and then CH2Cl2 (86 μL, 1.31 mmol) was added as an internal standard and cooled to 0°C. 500 μL of solution I-1 (containing 1.33 mmol of 1-hexylamine) was added thereto and stirred at 0°C for 20 hours (generated intermediate 2a: 1.17 mmol). 440 μL of solution I-2 (containing 1.17 mmol of 1-hexylamine) was further added thereto, and the consumption rate of intermediate 2a was measured. 1 The reaction was followed by H NMR measurement (see Figure 1(a)), and the second-order reaction rate constant (k 2a-3c The second-order reaction rate constant (k 2a-3c ) is shown in Figure 2.

[0072] For comparison, the second-order reaction rate constant (k 4-5 The second-order reaction rate constant (k4-5 ) is shown in Figure 2.

[0073] [ka]

[0074] As shown in Figure 2, the reactivity of compound (I) toward amines is estimated to be about 110 times and about 2500 times that of intermediate 2a and model compound 4, respectively. I-2a :k 2a-3c :k 4-5 was approximately 2640:22:1. In other words, it was revealed that compound (I) having a spiro structure is extremely reactive toward intermediate 2a and model compound 4. This high reactivity is thought to be due to the ring strain at the spiro structure site.

[0075] [Example 2] (Synthesis of dihydroxyurethanes with different amine moieties) Next, 1 molar equivalent of compound (I) was reacted with 1 molar equivalent of benzylamine to generate an intermediate, and then 1 molar equivalent of N-Boc-1,6-diaminohexane (Boc = tert-butoxycarbonyl group) was reacted with 1 molar equivalent of compound (I) to selectively synthesize a dihydroxyurethane having a different amine residue (hereinafter, sometimes referred to as "dihydroxyurethane 3d") in high yield. The reason for using benzylamine as the amine used in the first reaction step is that the reaction between benzylamine and the intermediate in preliminary experiments was slower than that of unbranched aliphatic amines due to the steric hindrance of benzylamine. The reason for using N-Boc-1,6-diaminohexane is to make it easier to separate and purify the synthesized dihydroxyurethane 3d using a molecular weight resolution column (SEC).

[0076] Specifically, benzylamine (142 mg, 5.32 mmol) was first added to a 2 mL volumetric flask, and DMF (super dehydrated) was added to prepare 2 mL of DMF solution (hereinafter, sometimes referred to as "solution II-1"). Compound (I) (250 mg, 1.33 mmol) was completely dissolved in DMSO / DMF (3.0 mL / 1.5 mL), and then CH2Cl2 (86 μL, 1.31 mmol) was added as an internal standard and cooled to 0 ° C. 500 μL of solution II-1 (containing 1.33 mmol of benzylamine) was added thereto and stirred at 0 ° C for 5 hours under nitrogen. N-Boc-1,6-diaminohexane (288 mg, 1.33 mmol) was added thereto and reacted by stirring at 0 ° C for 40 hours under nitrogen. Further, N-Boc-1,6-diaminohexane (58 mg, 0.266 mmol) was added, and the mixture was stirred under nitrogen at 80° C. for 3 hours to react. The progress of the reaction was monitored by diluting a portion of the reaction solution with DMSO-d6. 1 This was confirmed by 1 H NMR measurement. 1 The results of H NMR measurement are shown in Figure 3.

[0077] As shown in Figure 3, in the first step of the reaction, 1 H NMR measurements showed that intermediate 2b was produced with a selectivity of about 81%. In the second step, dihydroxyurethane 3d was produced with a selectivity of about 82% and an isolated yield of 75%.

[0078] [Example 3] (Synthesis of polyhydroxyurethane with ABAC type monomer sequence) In the first step, 1 molar equivalent of compound (I) (A) is reacted with 0.5 molar equivalent of diamine (B), and after compound (I) is almost consumed, the intermediates (compounds 6a and 6b in the reaction formula below; hereinafter, sometimes referred to as "intermediate 6a" and "intermediate 6b") are reacted with 0.5 molar equivalent of a different diamine (C) to synthesize polyhydroxyurethane having an ABAC type monomer sequence. The polyhydroxyurethanes synthesized are sometimes referred to as "poly-(Xyl / C6)", "poly-(Xyl / C3)", and "poly-(C3 / C6)".

[0079] [ka]

[0080] In each reaction, a mixed solvent of DMSO / DMF (2 / 1, vol / vol) was used to shorten the reaction time by increasing the concentration of compound (I) and to enable the reaction at 0°C. Each reaction was tracked by diluting a part of the reaction solution with DMSO-d6. 1 The measurement was performed by H NMR (see Figures 4 to 6). In addition, in the reaction of the first stage diamine (B) with compound (I), 0.5 molar equivalent of a different diamine (C) was added per molar equivalent of compound (I) when 96% by mass or more of compound (I) was consumed. Furthermore, after the second stage reaction, 0.1 molar equivalent of diamine (C) was added per molar equivalent of compound (I), and unreacted cyclic carbonate and chain carbonate generated by side reaction were completely consumed at 80°C to prevent gelation.

[0081] 1. Synthesis of poly-(Xyl / C6) p-Xylylenediamine (1.81 g, 13.3 mmol) was added to a 10 mL volumetric flask, and DMF (ultra-dehydrated) was added to prepare 10 mL of DMF solution (hereinafter, sometimes referred to as "Solution III-1-1"). Similarly, 1,6-diaminohexane (1.54 g, 13.3 mmol) was added to a 10 mL volumetric flask, and DMF (ultra-dehydrated) was added to prepare 10 mL of DMF solution (hereinafter, sometimes referred to as "Solution III-1-2"). Compound (I) (250 mg, 1.33 mmol) was added to a 25 mL flask, the flask was covered with a silicon septum, and the flask was replaced with N2. DMSO (ultra-dehydrated) / DMF (ultra-dehydrated) (3.0 mL / 1.5 mL) was added to this and completely dissolved, and then cooled to 0 °C. 500μL of solution III-1-1 (containing 6.65mmol of p-xylylenediamine) was added thereto, and the mixture was stirred at 0℃ under nitrogen for 7.25 hours. 500μL of solution III-1-2 (containing 6.65mmol of 1,6-diaminohexane) was added thereto, and the mixture was stirred at 0℃ under nitrogen for 40 hours, after which 1,6-diaminohexane (15.4mg, 0.133mmol) was added and the mixture was stirred at 80℃ for 3 hours. After cooling to room temperature, the solution was added dropwise to CHCl3 (about 100mL) and the precipitated solid was collected. The obtained solid was dissolved in DMF (about 4mL) and added dropwise to CHCl3 (about 100mL) to collect the precipitated solid, which was then dried under reduced pressure to obtain a white solid polyhydroxyurethane poly-(Xyl / C6) (387mg, yield 93% by mass).

[0082] 2. Synthesis of poly-(Xyl / C3) p-Xylylenediamine (1.81 g, 13 mmol) was added to a 10 mL volumetric flask, and DMF (ultra-dehydrated) was added to prepare 10 mL of DMF solution (hereinafter, sometimes referred to as "Solution III-2-1"). Similarly, 1,3-diaminopropane (197 mg, 2.66 mmol) was added to a 2 mL volumetric flask, and DMF (ultra-dehydrated) was added to prepare 2 mL of DMF solution (hereinafter, sometimes referred to as "Solution III-2-2"). Compound (I) (250 mg, 1.33 mmol) was added to a 25 mL flask, the flask was covered with a silicon septum, and the flask was replaced with N2. DMSO (ultra-dehydrated) / DMF (ultra-dehydrated) (3.0 mL / 1.5 mL) was added to this and completely dissolved, and then cooled to 0 ° C. 500 μL of solution III-2-1 (containing 6.65 mmol of p-xylylenediamine) was added thereto, and the mixture was stirred at 0° C. under nitrogen for 7.5 hours. 500 μL of solution III-2-2 (containing 6.65 mmol of 1,3-diaminopropane) was added thereto, and the mixture was stirred at 0° C. for 40 hours and at room temperature for 24 hours, after which 100 μL of solution III-2-2 (containing 0.133 mmol of 1,3-diaminopropane) was added thereto, and the mixture was stirred at 80° C. for 3 hours. After cooling to room temperature, the solution was added dropwise to CHCl3 (about 100 mL), and the precipitated solid was collected. The obtained solid was dissolved in DMF (about 4 mL), and the precipitated solid was collected by dropping into CHCl3 (about 100 mL), and dried under reduced pressure to obtain a white solid polyhydroxyurethane poly-(Xyl / C3) (342 mg, yield 88% by mass).

[0083] 3. Synthesis of poly-(C3 / C6) 1,3-Diaminopropane (197 mg, 2.66 mmol) was added to a 2 mL volumetric flask, and DMF (ultra-dehydrated) was added to prepare 2 mL of DMF solution (hereinafter, sometimes referred to as "Solution III-3-1"). Similarly, 1,6-diaminohexane (1.54 g, 13.3 mmol) was added to a 10 mL volumetric flask, and DMF (ultra-dehydrated) was added to prepare 10 mL of DMF solution (hereinafter, sometimes referred to as "Solution III-3-2"). Compound (I) (250 mg, 1.33 mmol) was added to a 25 mL flask, the flask was covered with a silicon septum, and the flask was replaced with N2. DMSO (ultra-dehydrated) / DMF (ultra-dehydrated) (3.0 mL / 1.5 mL) was added to this and completely dissolved, and then cooled to 0 °C. 500 μL of solution III-3-1 (containing 6.65 mmol of 1,3-diaminopropane) was added thereto, and the mixture was stirred at 0° C. under nitrogen for 3 hours. 500 μL of solution III-3-2 (containing 6.65 mmol of 1,6-diaminohexane) was added thereto, and the mixture was stirred at 0° C. for 40 hours, after which 100 μL of solution III-3-2 (containing 0.133 mmol of 1,6-diaminohexane) was added thereto, and the mixture was stirred at 80° C. for 3 hours. After cooling to room temperature, the solution was dropped into CHCl3 (about 100 mL) and the precipitated solid was collected. The obtained solid was dissolved in DMF (about 4 mL), and the precipitated solid was collected by dropping into CHCl3 (about 100 mL), and dried under reduced pressure to obtain a white solid polyhydroxyurethane poly-(C3 / C6) (335 mg, yield 89% by mass).

[0084] 4.Synthesis of poly-(Xyl-ran-C6) For comparison, a polyhydroxyurethane (poly-(Xyl-ran-C6)) with a random arrangement of diamine residues was also synthesized by reacting compound (I) with a diamine mixture of 0.5 molar equivalents of p-xylylenediamine and 1,6-diaminohexane per 1 molar equivalent of compound (I).

[0085] Specifically, p-xylylenediamine (1.81 g, 13. mmol) was first added to a 10 mL volumetric flask, and DMF (ultra-dehydrated) was added to prepare 10 mL of DMF solution (hereinafter, sometimes referred to as "solution III-4-1"). Similarly, 1,6-diaminohexane (1.54 g, 13.3 mmol) was added to a 10 mL volumetric flask, and DMF (ultra-dehydrated) was added to prepare 10 mL of DMF solution (hereinafter, sometimes referred to as "solution III-4-2"). 500 μL of solution III-4-1 (containing 6.65 mmol of p-xylylenediamine), 500 μL of solution III-4-2 (containing 6.65 mmol of 1,6-diaminohexane), and DMF (1.0 mL) were added to a 25 mL flask and cooled to 0 ° C. Compound (I) (250 mg, 1.33 mmol) was added thereto, and the mixture was stirred at 0 ° C for 18 hours. 50 μL of solution III-4-1 (containing 0.665 mmol of p-xylylenediamine) and 50 μL of solution III-4-2 (containing 0.665 mmol of 1,6-diaminohexane) were added thereto, and the mixture was stirred at 80° C. for 3 hours. After cooling to room temperature, the solution was added dropwise to CHCl3 (about 100 mL), and the precipitated solid was collected. The obtained solid was dissolved in DMF (about 4 mL), and the solution was added dropwise to CHCl3 (about 100 mL), and the precipitated solid was collected and dried under reduced pressure to obtain a white solid polyhydroxyurethane poly-(Xyl-ran-C6) (406 mg, yield 97% by mass).

[0086] Table 1 shows the number average molecular weight (Mn), molecular weight distribution (Mw / Mn), yield, reaction conditions, etc. for each of the polyhydroxyurethanes obtained in "1." to "4." above.

[0087] [Table 1]

[0088] As shown in FIG. 4(a), when 1 molar equivalent of compound (I) and 0.5 molar equivalent of p-xylylenediamine were reacted at 0° C. for 7 hours, the conversion rate of compound (I) was 98% by mass, of which the intermediate cyclic biscarbonate (intermediate 6a) was produced with a selectivity of about 91%, and by-products including dihydroxyurethane derivatives and linear carbonates were about 9%. Also, as shown in FIG. 4(b), when 0.5 molar equivalent of 1,6-diaminohexane was added to the reaction solution of compound (I) and p-xylylenediamine and reacted at 0° C. for 40 hours, the conversion rate of intermediate 6a was about 97%. Furthermore, 0.1 molar equivalent of 1,6-diaminohexane was added to 1 molar equivalent of compound (I) to react the unreacted cyclic carbonate and linear carbonate produced by the side reaction.

[0089] FIG. 5 shows the results of the reprecipitation-purified poly-(Xyl / C6) and, for comparison, the polyhydroxyurethanes (poly-Xyl and poly-C6) obtained by polyaddition of compound (I) with p-xylylenediamine or 1,6-diaminohexane. 1 As shown in FIG. 5, the spectrum of poly-(Xyl / C6) showed a pattern similar to that of poly-Xyl and poly-C6. However, the two methylene protons (H B , H C The chemical shifts of the methylene protons (H a ) were observed in different locations.

[0090] Figure 6 shows the three types of polyhydroxyurethane shown in Figure 5 and poly-(Xyl-ran-C6) with a random arrangement of diamine residues. 11 H NMR spectrum. As shown in FIG. 6, the methylene proton of poly-(Xyl-ran-C6) was split into four, and the peak tops of these peaks coincided with the peak tops of the methylene protons of poly-(Xyl / C6), poly-Xyl, and poly-C6. That is, the four split signals are due to the BAB sequence having p-xylylenediamine residue B on both sides of the dihydroxyurethane residue A, the CAC sequence having 1,6-diaminohexane residue C, and the BAC sequence having a different diamine residue. In addition, the production of intermediate 6a was about 90%, suggesting that the synthesized poly-(Xyl / C6) has an ABAC type monomer sequence of about 90% or more relative to the entire monomer sequence. In addition, poly-(Xyl / C3) 1 A similar tendency was observed in the H NMR spectrum (not shown). On the other hand, in poly-(C3 / C6) having two types of aliphatic diamine residues differing only in the number of carbon atoms, no splitting of the corresponding methylene protons was observed (not shown). This is probably because there was no difference in the chemical shift of the corresponding methylene protons between the aliphatic diamine residues.

[0091] In addition, the obtained polyhydroxyurethane with ABAC type monomer sequence and polyhydroxyurethane with random sequence were subjected to thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and compared with poly-C3, poly-C6 and poly-Xyl synthesized using only one kind of diamine. The results are shown in Table 1.

[0092] As shown in Table 1, no clear difference was observed in the thermal properties (glass transition temperature (Tg) and 5% weight loss temperature (Td5)) between poly-(Xyl / C6) and poly-(Xyl-ran-C6), and the effect of the monomer sequence was not obtained with the combination of diamine residues used in this example. In the future, it is expected that the effect of the monomer sequence will be more pronounced by performing molecular design that actively incorporates interactions between side chains.

[0093] On the other hand, the Tg of polyhydroxyurethanes containing two diamine residues was significantly lower than that of polyhydroxyurethanes containing one diamine residue. In particular, the high Tg of 83.5°C shown by poly-Xyl was completely lost in poly-(Xyl / C6), poly-(Xyl-ran-C6) and poly-(Xyl / C3) containing p-xylylenediamine residues, and furthermore, poly-(Xyl / C6) and poly-(Xyl-ran-C6) showed lower values ​​than that of poly-C6. The following reasons are considered for this decrease in Tg. In polyhydroxyurethanes containing only one diamine residue such as poly-Xyl and poly-C6, the phenyl groups, urethane groups and hydroxyl groups are always located at equal intervals along the polymer chain, so that intermolecular interactions (π-π interactions and hydrogen bonds) can be efficiently formed (see Figure 7(a)). On the other hand, in polyhydroxyurethane with ABAC type monomer sequence or random sequence having two kinds of diamine residues, the distance between these functional groups is different due to the different chain lengths of the diamine residues, and in order to have efficient interaction between polymer chains, the corresponding sequences must interact with each other (ABA sequences interact with ABA sequences in other polymer chains, and ACA sequences interact with ACA sequences in other polymer chains). In other words, even in polyhydroxyurethane with a completely controlled ABAC type monomer sequence, the ABA sequences and ACA sequences must be close to each other between polymer chains, and if the same sequences are not close to each other, urethane groups and hydroxyl groups that cannot form intermolecular hydrogen bonds are generated, and phenyl groups that cannot participate in π-π interactions are also generated (see Figure 7(b)). [Industrial Applicability]

[0094] According to the production method of this embodiment, it is possible to provide a novel method for producing polyhydroxyurethane, which can be produced by a simple procedure and has a controlled monomer sequence.

Claims

1. The method includes a step of reacting a bifunctional cyclic carbonate (A) having a spiro structure with a diamine (B), and then reacting the resulting reaction product with a diamine (C) to obtain a polyhydroxyurethane, The bifunctional cyclic carbonate (A) is 2,4,8,10-tetraoxaspiro[5,5]-undecane-3,9-dione, The diamine (B) and the diamine (C) have different structures, A method for producing polyhydroxyurethane having an ABAC type monomer sequence, wherein the amount of the diamine (B) added is 0.4 molar equivalents or more and 0.6 molar equivalents or less per molar equivalent of the difunctional cyclic carbonate (A).

2. The method according to claim 1, wherein the amount of the diamine (B) added is 0.5 molar equivalents per molar equivalent of the difunctional cyclic carbonate (A).

3. The method according to claim 1 or 2, wherein the reaction in the step is carried out at 5° C. or lower.

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