JP2008280399A - Method for producing block copolymer, and block copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable polycarbonate having a high thermal decomposition temperature, and to provide a method for producing the same. <P>SOLUTION: In the production method of the present invention, a copolymer having a polycarbonate copolymer block and a polyester copolymer block is produced according to a first reaction process and a second reaction process in the presence of a porphyrin-based metal complex. In the first reaction process, carbon dioxide is copolymerized with an alkylene oxide represented by general formula (1). In the second reaction process, the alkylene oxide represented by the general formula (1) is copolymerized with an acid anhydride represented by general formula (2). In the general formula (1), R<SP>1</SP>represents a hydrogen atom or a methyl group. In the general formula (2), Z represents a group which forms a five membered ring or a six membered ring. However, the alkylene oxide represented by the general formula (1) used in the second reaction process may be the same as or may be different from that of the alkylene oxide represented by the general formula (1) used in the first reaction process. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a block copolymer and a block copolymer having a polycarbonate and a polyester.

  The method of obtaining polycarbonate by copolymerization reaction of alkylene oxide and carbon dioxide is a significant technique in that carbon dioxide is used as a raw material for synthetic resins.

  In the copolymerization method of alkylene oxide and carbon dioxide, many methods using a catalyst have been proposed. As the catalyst, for example, an inorganic zinc compound (see, for example, Non-Patent Document 1), an aluminum-based catalyst, a cobalt complex, and the like are disclosed.

  Moreover, the aliphatic polycarbonate obtained by this copolymerization reaction has the characteristics of having transparency and being completely decomposed by heating. Therefore, as an application, aliphatic polycarbonate can be used for materials such as an optical fiber, an optical disk, a ceramic binder, and lost foam casting, in addition to being applied to general molded products, films, fibers, and the like.

  Furthermore, since some of the aliphatic polycarbonates also have biodegradability, the biodegradable biomedical materials such as sustained-release drug capsules, additives to biodegradable resins, or the main biodegradable resins. It can also be applied as a component. Examples of such biodegradable aliphatic polycarbonates include aliphatic polycarbonates made from ethylene oxide or propylene oxide.

As for the polycarbonate copolymerized using two types of alkylene oxide and carbon dioxide, for example, a combination of propylene oxide and cyclohexene oxide (see, for example, Non-Patent Documents 2 to 4 and Patent Document 1), ethylene oxide and propylene. Combinations of oxides (for example, see Non-Patent Document 5) and combinations of styrene oxide and cyclohexene oxide (for example, see Non-Patent Document 6) are disclosed. Moreover, the copolymer which consists of 2 types of alkylene oxides and carbon dioxide among ethylene oxide, propylene oxide, cyclohexyl ethylene oxide, and phenylethylene oxide is disclosed (refer patent document 2).
Chinese Patent Application No. 1887934 Chinese Patent Application Publication No. 1408440 ACS Symp. Ser. 921 (Feed stocks for the Future), 2006, 116-129 Lei Shi et al., Macromolecules, 2006, 39, 5679-5685 Koji Nakano et al., Angrew. Chem. Int. Ed, 2006, 45, 7274-7277 Sudhir D. Thorat, J. Appl. Polym. Sci. 2003, 89, 1663-1176 Zhilog Quan et al., Macromol. Symp. 2003, 195, 281-286 Donald j. Darensbourg and Marc S. Zimmer, Macromolecules 1999, 32 (7), 2137-2140

However, the biodegradable aliphatic polycarbonate has a low thermal decomposition temperature, which is inconvenient for practical use such as application to an injection molding machine. For example, the thermal decomposition temperature of polypropylene polycarbonate is about 240 ° C., and in the case of polyethylene carbonate, it is about 220 ° C.
Accordingly, an object of the present invention is to provide a biodegradable polycarbonate having a high thermal decomposition temperature and a method for producing the same.

  A method for increasing the thermal decomposition temperature of a biodegradable aliphatic polycarbonate was investigated. A biodegradable polyester, which is a copolymer of an acid anhydride and an alkylene oxide, was bonded to the biodegradable aliphatic polycarbonate. Was found to be beneficial. A copolymer having a wide molecular weight distribution also has a wide distribution of thermal decomposition temperatures, making it difficult to apply to applications such as injection molding. However, it has been found that according to a specific production method, a biodegradable block copolymer having a narrow molecular weight distribution can be obtained.

  On the other hand, the reactivity of carbon dioxide and acid anhydride is greatly different from that of alkylene oxide. However, regarding the thermal decomposition temperature, there is no difference between the random copolymer and the block copolymer so as to cause a problem in practical use.

Furthermore, as a result of intensive studies on the production method of such a block copolymer, it was revealed that the temperature conditions, the amount of Lewis base used, and the like affect the yield.
That is, the present invention described below has solved the problem.

<1> a first reaction step in which carbon dioxide and an alkylene oxide represented by the following general formula (1) are copolymerized in the presence of a metal complex coordinated with a porphyrin-based compound;
Second reaction in which an alkylene oxide represented by the following general formula (1) and an acid anhydride represented by the following general formula (2) are copolymerized in the presence of a metal complex coordinated with a porphyrin-based compound. Process,
It is a manufacturing method of the block copolymer characterized by having.

In general formula (1), R ¹ represents a hydrogen atom or a methyl group. In General Formula (2), Z represents a group that forms a 5-membered ring or a 6-membered ring. However, the alkylene oxide represented by the general formula (1) used in the second reaction step is the same as or different from the alkylene oxide represented by the general formula (1) used in the first reaction step. Also good.

<2> The alkylene oxide represented by the general formula (1) is propylene oxide or ethylene oxide, and the acid anhydride represented by the general formula (2) is succinic anhydride. It is a manufacturing method of the block copolymer as described in <1>.

<3> The block copolymer according to <1> or <2>, wherein the metal complex coordinated with the porphyrin compound is a metal complex represented by the following general formula (3): It is a manufacturing method.

In the general formula (3), each R ³ independently represents a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, or a tert-butyl group. Represents a group, a phenyl group, a methoxy group, an ethoxy group, a trifluoromethyl group, a fluorine atom, a chlorine atom, or a bromine atom, and n represents an integer of 0 to 5.

<4> The method for producing a block copolymer according to any one of <1> to <3>, wherein a Lewis base is used in the first reaction step and the second reaction step. It is.

<5> In the first reaction step and the second reaction step, 0.1 to 5 mol of the Lewis base is used with respect to 1 mol of the metal complex coordinated with the porphyrin compound. It is a manufacturing method of the block copolymer as described in <4>.

<6> In the first reaction step and the second reaction step, 0.5 to 0.75 mol of the Lewis base is used with respect to 1 mol of the metal complex coordinated with the porphyrin compound. The method for producing a block copolymer according to <4>.

<7> The block copolymer according to any one of <4> to <6>, wherein the Lewis base is a compound having a structure with high electron-sharing properties and having an unpaired electron. It is a manufacturing method of a polymer.

<8> The method for producing a block copolymer according to <7>, wherein the Lewis base is a pyridine compound or an imidazole compound.

<9> The method for producing a block copolymer according to <8>, wherein the pyridine-based compound is represented by the following general formula (4).

In General Formula (4), R ⁴ represents a methyl group, a formyl group, or a substituted amino group, and m represents an integer of 0 to 5.

<10> The method for producing a block copolymer according to <9>, wherein the pyridine-based compound is 4- (N, N-dimethylamino) pyridine.

<11> The method for producing a block copolymer according to <8>, wherein the imidazole compound is represented by the following general formula (5).

In general formula (5), R ⁵ represents a substituted or unsubstituted alkyl group.

<12> The method for producing a block copolymer according to <11>, wherein the imidazole compound is N-methylimidazole.

<13> The production of the block copolymer according to any one of <1> to <12>, wherein the carbon dioxide partial pressure in the first reaction step is 0.1 to 25 MPa. Is the method.

<14> In the first reaction step, the copolymerization reaction is performed in a temperature range of 0 ° C. or higher and 100 ° C. or lower, and the block co-polymerization according to any one of the above <1> to <13> It is a manufacturing method of coalescence.

<15> The block co-polymerization according to any one of <1> to <14>, wherein in the second reaction step, a copolymerization reaction is performed in a temperature range of 20 ° C. or more and 120 ° C. or less. It is a manufacturing method of coalescence.

<16> Any one of the above <1> to <15>, wherein a chain transfer agent having active hydrogen is used in at least one of the first reaction step and the second reaction step. It is a manufacturing method of the block copolymer as described in an item.

<17> The block copolymer according to <16>, wherein the chain transfer agent is used so as to contain 5 mol or more of the active hydrogen with respect to the metal complex coordinated with the porphyrin-based compound. It is a manufacturing method.

<18> The method for producing a block copolymer according to <16> or <17>, wherein the chain transfer agent having active hydrogen contains one or more active hydrogen groups in one molecule. It is.

<19> The method for producing a block copolymer according to <18>, wherein the chain transfer agent having active hydrogen has one or more OH groups or COOH groups in one molecule.

<20> The block transfer according to any one of <16> to <19>, wherein the chain transfer agent having active hydrogen contains two or more active hydrogen groups in one molecule. It is a manufacturing method of a polymer.

<21> The method for producing a block copolymer according to <20>, wherein the chain transfer agent having active hydrogen is water.

<22> A block copolymer obtained by the production method according to any one of <1> to <21>.

<23> A polycarbonate block obtained by a copolymerization reaction of carbon dioxide with an alkylene oxide represented by the following general formula (1), an alkylene oxide represented by the following general formula (1), and the following general formula (2). A block copolymer having a polyester block by a copolymerization reaction with an acid anhydride.

In general formula (1), R ¹ represents a hydrogen atom or a methyl group. In General Formula (2), Z represents a group that forms a 5-membered ring or a 6-membered ring. However, R ¹ of the alkylene oxide represented by the general formula (1) in the polycarbonate block may be the same as or different from R ^{1 of the} alkylene oxide represented by the general formula (1) in the polyester block. .

<24> The block copolymer according to <22> or <23>, wherein both ends are hydroxyl groups.

<25> The block copolymer according to any one of <22> to <24>, wherein the alternating copolymerization ratio of the polycarbonate block and the polyester block is 95% or more. is there.

<26> The ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.01 or more and 1.20 or less, according to any one of the above <22> to <25>, It is a block copolymer.

  ADVANTAGE OF THE INVENTION According to this invention, the copolymer which raised the thermal decomposition temperature while having biodegradability and its manufacturing method can be provided.

  The method for producing a copolymer of the present invention has a first reaction step and a second reaction step. In the first reaction step, carbon dioxide and an alkylene oxide represented by the general formula (1) are copolymerized in the presence of a metal complex coordinated with a porphyrin-based compound. In the second reaction step, an alkylene oxide represented by general formula (1) and an acid anhydride represented by general formula (2) are copolymerized in the presence of a metal complex coordinated with a porphyrin-based compound. Let

  Below, the material which can be used for the manufacturing method of this invention is demonstrated first, then the manufacturing method of this invention is demonstrated, and the copolymer obtained by the manufacturing method of this invention is demonstrated after that.

<Metal complex>
In the present invention, a metal complex coordinated with a porphyrin-based compound is used as a catalyst. Particularly preferred is a cobalt complex represented by the following general formula (3).

In the general formula (3), each R ³ independently represents a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, or a tert-butyl group. Represents a group, a phenyl group, a methoxy group, an ethoxy group, a trifluoromethyl group, a fluorine atom, a chlorine atom, or a bromine atom, and n represents an integer of 0 to 5.

  From the viewpoint of obtaining a copolymer having a high copolymerization reaction rate, a high alternating copolymerization ratio, and a narrow molecular weight distribution as the metal complex represented by the general formula (3), the following structural formula (1 It is preferable that it is a metal complex represented by this.

On the other hand, from the viewpoint of high activity as a catalyst and solubility in supercritical carbon dioxide, a metal complex of a polysubstituted porphyrin compound in which n in the general formula (3) is 2 or more is preferable. When n is 2 or more, the plurality of R ³ may be different substituents or the same substituent, but from the viewpoint of ease of production, they must be the same substituent. Is preferred.
When n is 2, the substitution position of R ³ is preferably the meta position, and when n is 3, the substitution positions of R ³ are preferably the ortho position and the para position, and all of n is 5 It may be a substitution. Therefore, a suitable metal complex of a polysubstituted porphyrin-based compound is a metal complex represented by the general formulas (6) to (8).

^{R 3} in the general formula (6) to (8) are each independently the same meaning as ^{R 3} in Formula (3). Furthermore, R ³ in the general formula (6) is more preferably a methoxy group, a fluorine atom, a chlorine atom, or a bromine atom, and R ^{3 in the} general formula (7) is more preferably a tert-butyl group. R ³ in the general formula (8) is more preferably a fluorine atom, a chlorine atom, or a bromine atom.

  Specific examples of metal complexes coordinated by a porphyrin-based compound having a polysubstituted phenyl group are shown below, but are not limited to these metal complexes.

本発明にかかる金属錯体は、１種類のみを用いて、あるいは２種類以上を併用してもよいが、単一種を用いることが、反応に好適な溶媒、触媒濃度、ルイス塩基、温度、圧力を調節しやすい観点から好ましい。

The metal complex according to the present invention may be used alone or in combination of two or more. However, the use of a single species may provide a suitable solvent, catalyst concentration, Lewis base, temperature, and pressure for the reaction. It is preferable from the viewpoint of easy adjustment.

<Alkylene oxide>
The alkylene oxide used in the present invention is an alkylene oxide represented by the following general formula (1).

In general formula (1), R ¹ is a hydrogen atom or a methyl group from the viewpoint of biodegradability.

  Specific examples of the compound represented by the general formula (1) are shown below.

<Acid anhydride>
The acid anhydride used in the present invention is an alkylene oxide represented by the following general formula (2).

  In General Formula (2), Z represents a group that forms a 5-membered ring or a 6-membered ring, and more preferably a group that forms a 5-membered ring. Specifically, it represents an alkylene group having 2 to 3 carbon atoms, an arylene group, or an alkenylene group having 2 to 3 carbon atoms, and is preferably an alkylene group having 2 to 3 carbon atoms from the viewpoint of biodegradability.

  Specific examples of the compound represented by the general formula (2) in which Z is an alkylene group include succinic anhydride, glutaric anhydride, adipic anhydride, pimelic anhydride, suberic anhydride, azelaic anhydride, sebacic anhydride Can be mentioned. In the compound represented by the general formula (2), specific examples of Z being an arylene group include phthalic anhydride, and specific examples of Z being an alkenylene group include maleic anhydride, citraconic anhydride, Mention may be made of itaconic anhydride.

  Among these compounds, the compound represented by the general formula (2) is preferably succinic anhydride, phthalic anhydride, and maleic anhydride, and succinic anhydride is reactive or biodegradable. From the viewpoint of sex.

<Lewis base>
In the present invention, a Lewis base can coexist with the metal complex as a catalyst. The Lewis base is presumed to coordinate with the metal portion of the metal complex to further enhance the function as a catalyst.
The Lewis base is preferably a compound having a structure having a high electron-sharing property and having an unpaired electron so that it can be easily coordinated to the metal portion of the metal complex.

As the Lewis base, when the metal complex represented by the structural formula (1) is used as the metal complex coordinated with the porphyrin compound, it is preferable to use a pyridine compound or an imidazole compound.
Although it does not restrict | limit especially as a pyridine type compound, It is a compound represented by following General formula (4).

In the general formula (4), R ⁴ represents a substituted or unsubstituted methyl group, formyl group, or substituted amino group, more preferably a dimethylamino group, a methyl group, or a formyl group, still more preferably dimethylamino. It is a group.

The substitution position of R ⁴ is preferably 4-position or 3-position, and more preferably 4-position.
m represents an integer of 0 to 5, and is preferably an integer of 0 to 1.

  Of the pyridine compounds used in the present invention, pyridine, 4-methylpyridine, 4-formylpyridine, and 4- (N, N-dimethylamino) pyridine are preferable, and pyridine and 4-methylpyridine are more preferable. 4- (N, N-dimethylamino) pyridine, particularly preferably 4- (N, N-dimethylamino) pyridine (DMAP).

  The imidazole compound as the Lewis base is not particularly limited, but is a compound represented by the following general formula (5).

In general formula (5), R ⁵ represents a substituted or unsubstituted alkyl group, for example, a methyl group, an ethyl group, or a propyl group. More preferably, it is a methyl group. That is, in the general formula (5), a particularly preferable compound is N-methylimidazole.

<Chain transfer agent>
In the production method of the present invention, a chain transfer agent having active hydrogen can be used. When a chain transfer agent is used, the chain transfer agent is used so as to contain an equimolar amount or more of the active hydrogen with respect to the metal complex.

The chain transfer agent having active hydrogen has one or more active hydrogen groups in one molecule.
Specific examples of such a chain transfer agent include water, an organic compound having a hydroxyl group, an organic compound having an SH group, an organic compound having a carboxyl group, and alkanolamines. Further, those obtained by addition polymerization of alkylene oxide to these compounds can also be applied. In addition, a plurality of types of reaction products of these chain transfer agents can be applied.

  Examples of the organic compound having a hydroxyl group include primary, secondary, tertiary monohydric alcohol, dihydric alcohol, polyhydric alcohol, phenols, polyvinyl alcohol, partially or substantially completely hydrolyzed polyvinyl acetate, And reaction products derived from these organic compounds having a hydroxyl group.

  As the monohydric alcohol, an aliphatic, aromatic, alicyclic alcohol, cellosolve compound, ether bond, or monoalcohol having an ester bond can be preferably used. Specifically, for example, 1-propanol, 2-propanol, n-butanol, 2-butanol, 2-ethylhexanol, octanol, cetyl alcohol, isopropanol, 2-methyl 2-propanol, benzyl alcohol, cyclohexyl alcohol, ethylene glycol Mention may be made of monomethyl ether.

  Specific examples of the polyhydric alcohols higher than the dihydric alcohol include 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanedio-1,6-hexanediol. 1,4-cyclohexanediol, glycerin, polyglycerin, trimethylolpropane, pinacol, catechol, triethylolpropane, pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolpropane monoallyl ether, hexane Examples include triols, glycols, and saccharides.

  Specific examples of glycols include glycol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,2-, 1,3- and 1,4-butylene glycol, And neopentyl glycol.

  Examples of the saccharide include α-methyl glucoside, hydroxymethyl glucoside, hydroxyethyl glucoside, hydroxypropyl glucoside, brucose, fructose, sucrose, raffinose, sorbitol, mannitol and the like.

  Examples of the phenols include phenol, p-monochlorophenol, p-cresol, thymol, xylenol, hydroquinone, resorcinol, resorcinol residual oil, phloroglucinol, o-, m-, p-hydroxystyrene, saligenin, bisphenol A, Bisphenol F, bisphenol S, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenylsulfone, 4,6,4-trihydroxydiphenyl Examples include dimethylmethane and long-chain bisphenol.

Polyvinyl alcohol and polyvinyl acetate may be a copolymer or a homopolymer. Examples of the vinyl alcohol copolymer (copolymer) include those obtained by hydrolyzing the following vinyl acetate copolymer.
Examples of the vinyl acetate copolymer include vinyl acetate-butadiene copolymer, vinyl acetate-styrene copolymer, vinyl acetate-acrylonitrile or methacrylonitrile copolymer, vinyl acetate-vinyl chloride copolymer, vinyl acetate. -Vinylidene chloride copolymers, copolymers of vinyl acetate and other monomers (dichlorostyrene, vinyl ethyl ether, ethylene, propylene, isobutylene, isoprene, etc.)).

Examples of the organic compound having an SH group include mercaptans, thiols, and polythiols.
Specific examples of mercaptans and thiols include 1-pentanethiol, 2-methyl-1-butanethiol, 3-methyl-1-butanethiol, thiophenol, o-, m-, p-thiocresol, 1,2- Ethanedithiol, ethanethiol, furfuryl mercaptan, 1-hexanethiol, thio-1-naphthol, 2-propanethiol, dithioresorcinol, thioglycerol, propanetrithiol, 1,4-benzenedithiol, monothiohydroquinone, thiodiglycol And thiomonoglycol.

  Examples of alkanolamines include diethanolamine and triethanolamine.

  Chain transfer agents with active hydrogen can have two or more identical or different functional group species per molecule. Specific examples of compounds containing different types of functional groups include hydroxycarboxylic acids, amino acids and carboxylic acid-containing materials. Furthermore, two or more of these chain transfer agents having active hydrogen can be used in combination.

<Brensted acid compound>
In the production method of the present invention, a Brensted acid compound can be added to convert the terminal to a hydroxyl group, thereby stopping the reaction. Examples of such a Brensted acid compound include methanol and methanol containing hydrochloric acid.

<Manufacturing method>
In the production method of the present invention, in the presence of the porphyrin-based metal complex, the copolymer having a polycarbonate copolymer block and a polyester copolymer block is obtained through the first reaction step and the second reaction step. A polymer is produced.
The metal complexes used in the first reaction step and the second reaction step may be the same or different, but it is preferable to use the same metal complex from the viewpoint of the simplicity of the operation. At this time, from the viewpoint of the yield and the rate of formation of the alternating copolymer, the cobalt complex represented by the general formula (3) is preferable, and in particular, the cobalt represented by the structural formula (1). Complexes are preferred. Hereinafter, the production method of the present invention will be described in detail.

(First reaction step)
In the first reaction step, carbon dioxide and an alkylene oxide represented by the general formula (1) are copolymerized.

  In the first reaction step, it is sufficient that the metal complex according to the present invention is present in an amount of 0.1 mol% to 1 mol% with respect to the alkylene oxide. More preferably, it is a case where it is made to exist in 0.2 mol%-0.5 mol%.

The pressure during the reaction is preferably 2 to 26 MPa, and the reaction proceeds even at 0.1 to 2 MPa.
The carbon dioxide partial pressure is preferably 0.1 to 25 MPa, more preferably 2 to 25 MPa, and the reaction proceeds even at 0.1 to 2 MPa. The carbon dioxide partial pressure may be adjusted by filling only carbon dioxide, or may be adjusted so that the carbon dioxide partial pressure is within the above range in the presence of nitrogen. Preferably, the carbon dioxide pressure is adjusted in the presence of nitrogen. When coexisting carbon dioxide and nitrogen, it is more preferable to adjust the nitrogen so that the pressure is 1 atm and the remainder is the carbon dioxide pressure.

  Note that carbon dioxide is in a supercritical state under a pressure of 7.38 MPa or more. In the present invention, the reaction can be performed even in such a supercritical state. In the case of supercritical carbon dioxide, a copolymerization reaction can be performed without using a reaction solvent described later, so that a post-treatment step of removing the reaction solvent can be omitted, and unnecessary solvent does not remain in the copolymer. .

  The temperature during the copolymerization reaction in the first reaction step is preferably controlled to be 100 ° C. or less, more preferably 0 ° C. or more and 100 ° C. or less, and further preferably 0 ° C. or more and 60 ° C. or less. Particularly preferably, it is 20 ° C. or higher and 40 ° C. or lower.

The copolymerization reaction of alkylene oxide and carbon dioxide may be performed in a solvent or without a solvent.
In the case of using a solvent, one or more of aromatic hydrocarbons such as benzene and toluene; halogenated hydrocarbons such as dichloromethane and chloroform; ethers such as tetrahydrofuran can be used.

  The solvent is preferably dichloromethane, toluene, dimethylformamide, or tetrahydrofuran, more preferably dichloromethane, dimethylformamide, or tetrahydrofuran, and still more preferably dichloromethane or tetrahydrofuran.

  In the present invention, it is preferable to use dichloromethane as a solvent or without solvent. However, when copolymerizing cyclohexene oxide and carbon dioxide using the metal complex of the structural formula (1), dichloromethane is used as a solvent. It is preferable to use it.

  When dichloromethane is used as a solvent, the volume ratio (solvent: alkylene oxide) to alkylene oxide is preferably 0: 100 to 90:10, more preferably 0: 100 to 70:30 ( When the solvent is 0, it indicates the case of no solvent.)

  As described above, a Lewis base can be used in the present invention. The Lewis acid is presumed to be coordinated to the metal part of the metal complex. The reaction scheme at that time is shown in Scheme 1 below.

In the above reaction Scheme 1, BASE represents a Lewis base, ^{R 1} represents a ^{R 1} in the general formula (1).

  The use amount of the Lewis base is preferably 0.1 to 5 mol, and more preferably 0.5 to 0.75 mol, relative to 1 mol of the metal complex coordinated with the porphyrin-based compound. If it is used in the said range, an alternating copolymer will be produced | generated without producing a cyclic carbonate (compound which alkylene oxide and carbon dioxide reacted 1 mol at a time) without reducing a yield. Moreover, since it is easy to take in a carbon dioxide from a viewpoint of reaction rate, it is difficult to produce | generate the polyether which only the alkylene oxide reacted.

Further, as described above, in the present invention, a chain transfer agent having active hydrogen can be used.
The present inventors have clarified that a chain transfer agent having active hydrogen has a great influence on the molecular weight and molecular weight distribution of a copolymer. The cause of this is presumed to be due to the exchange reaction of the active hydrogen of the chain transfer agent with the metal complex, but the present invention is not limited to such a mechanism.

In the following, regarding the above estimation mechanism, a compound having a hydroxyl group (ROH) is used as a chain transfer agent having active hydrogen, and tetraphenylporphinatocobalt chloride [(TPP) CoCl] is used as a metal complex, so that alkylene oxide and dioxide dioxide are used. A case where carbon is copolymerized will be described as an example.
In this reaction system, a copolymer of carbon dioxide and alkylene oxide can be obtained in a high yield, and since the carbonate bond content is extremely high, the carbon dioxide and alkylene oxide react alternately. It has been confirmed that it is a copolymer.

As shown in Scheme 2 above, when the copolymerization reaction proceeds, a copolymer (1) having Cl derived from a metal complex at one end and a cobalt catalyst at the other end is generated. Here, when ROH is present, the metal complex and active hydrogen of ROH are exchanged, and a metal complex [(TPP) CoOR] in which OR is bonded to cobalt, and a copolymer in which one end is Cl and the other end is OH. (2) is generated.
(TPP) CoOR proceeds with a copolymerization reaction in the same manner as (TPP) CoCl to produce a copolymer (3) having one terminal OR and the other terminal having a cobalt catalyst. If ROH is present at this time, the active hydrogen of ROH and the metal complex undergo an exchange reaction to produce (TPP) CoOR and a copolymer (4) in which one end is OR and the other end is OH.
Thus, as long as ROH is present, the metal complex is circulated and can participate in the copolymerization reaction.

In addition, when not using the chain transfer agent which has active hydrogen, since only the said copolymer (1) is obtained, the molecular number of the produced | generated copolymer is equivalent to the molecular number of a metal complex.
On the other hand, when a chain transfer agent having active hydrogen is used, the resulting copolymer becomes the above copolymer (2), copolymer (3), and copolymer (4). As a result, ROH molecules As many copolymer molecules are generated as the number of copolymers derived from the number, and the total number of molecules of the resulting copolymer is the sum of the number of molecules of the metal complex and the number of molecules of active hydrogen.
In addition, (TPP) CoOR and (TPP) CoCl show equivalent reactivity, so the molecular weights of the copolymers resulting from them are all the same, and the molecular weight distribution of the obtained copolymer is expressed by GPC. The chromatogram shows one peak. Accordingly, the degree of polymerization of the copolymer is the number of molecules of the reacted monomers (alkylene oxide and carbon dioxide) with respect to the total number of molecules of the charged metal complex and active hydrogen.

  As a result, in a reaction system using a chain transfer agent having active hydrogen, (1) a copolymer having a larger number of molecules than a metal complex can be produced, and (2) a copolymer having a narrow molecular weight distribution is obtained. (3) A copolymer having a desired molecular weight can be obtained by adjusting the mixing ratio of the raw materials. (4) When water is used as a chain transfer agent, hydroxyl groups are formed at both ends. (5) From the result of the above (1), the amount of expensive metal complex used can be reduced.

  Here, a reaction scheme when a chain transfer agent having two or more active hydrogen groups in one molecule is used will be considered. In the following scheme 3, HO—R—OH will be described as an example of a chain transfer agent having two or more active hydrogen groups in one molecule.

When HO—R—OH is present, the metal complex and the active hydrogen of HO—R—OH are exchanged, and the metal complex [(TPP) CoOROH] in which —O—R—OH is bonded to cobalt, and one end is Cl. To produce a copolymer (5) whose other end is OH.
When the copolymerization reaction proceeds with the generated (TPP) CoOROH, a copolymer (6) having one end with OROH and the other end with a cobalt catalyst is generated. Since the active hydrogen of OROH exists at this one end, the active hydrogen and the metal complex can exchange with each other. Thereby, a copolymer (7) having a metal complex at both ends is generated, and as a result, molecules grow from both ends.
Therefore, when a chain transfer agent having two active hydrogens in one molecule is used, the resulting copolymer is about twice as much as when a chain transfer agent having one active hydrogen in one molecule is used. Has a molecular weight.

  When the copolymer (7) having a metal complex at both ends undergoes an exchange reaction with HO—R—OH, a metal complex [(TPP) CoOROH] in which —O—R—OH is bonded to cobalt is generated. The complex is circulated and can participate in the copolymerization reaction.

  Incidentally, the copolymer (5) having Cl at one end and OH at the other end is produced in the same amount as the number of molecules of the metal complex, but the amount of the metal complex is significantly reduced compared to the amount of the chain transfer agent. If prepared in the above, most of the obtained copolymer becomes the copolymer (8), and the proportion of the copolymer (5) is extremely small. Therefore, the molecular weight distribution of the obtained copolymer can be approximated to the molecular weight distribution of the copolymer (8) by adjusting the compounding ratio of the metal complex and the chain transfer agent, and the molecular weight distribution can be narrowed. Can do.

  In Scheme 3, HO—R—OH has been described as an example of a chain transfer agent having two active hydrogens in one molecule (bifunctional chain transfer agent), but other bifunctional linkages such as HOOC—R—COOH. Even if it is a transfer agent, it is presumed that the reaction proceeds similarly.

  As a specific example of a chain transfer agent having two active hydrogens in one molecule, a scheme when water is applied is shown below.

  When a chain transfer agent having three active hydrogens in one molecule is used, a chain transfer agent having one active hydrogen in one molecule as shown in the copolymer (9) of the following scheme 5 It is estimated that the molecular weight is about 3 times that of when using.

As described above, when a chain transfer agent having at least one active hydrogen in one molecule is used, (1) a copolymer having a larger number of molecules than a metal complex can be generated (that is, the amount of catalyst is reduced). (2) A copolymer having a narrow molecular weight distribution can be obtained. (3) A copolymer having a desired molecular weight can be obtained by adjusting the mixing ratio of raw materials. (4 ) The end group can be modified.
If a polyfunctional chain transfer agent having two or more active hydrogens in one molecule is used, in addition to the above effects, as shown in Scheme 3 or 4, the chain transfer agent can be linked or crosslinked. A copolymer with different physical properties can be obtained.

In addition, when a chain transfer agent having at least one active hydrogen in one molecule and having a high molecular weight is used, copolymers having various physical properties are obtained depending on the properties of the polymer chain transfer agent. be able to.
On the other hand, if a chain transfer agent having at least one active hydrogen in one molecule and having a low molecular weight, such as water, ethylene glycol, glycerin, etc., is used, a polymer skeleton having a high carbonate bond content can be obtained. It becomes the copolymer which has. Since the carbonate bond has a higher bond energy than the ether bond, the resulting copolymer is excellent in weather resistance and acid resistance.

In particular, when water is applied as the chain transfer agent having active hydrogen, the water used in synthesizing the metal complex represented by the structural formula (1) may remain, and the water removal process is simplified. It has the further advantage that the complexity of the work in the manufacturing process can be eliminated. Moreover, even if water as a chain transfer agent is further added in such a state, the same effect as that obtained by using one type of chain transfer agent can be obtained.
The remaining amount of water attached to the metal complex used in the copolymerization reaction is confirmed by checking the GPC chart of the copolymer obtained by the copolymerization reaction, from the amount of charged water and the amount of metal complex. It can be estimated. Based on this result, a copolymer having a desired molecular weight can be produced.

  From the viewpoint of obtaining a desired number of molecules and molecular weight while reducing the amount of expensive metal complex used, the chain transfer agent having active hydrogen seems to have 1 mol or more of active hydrogen per 1 mol of the metal complex. Preferably, 5 mol or more of active hydrogen is present, and more preferably, 10 mol or more of active hydrogen is present.

  In addition, when applying a chain transfer agent, the cobalt complex represented with General formula (3) is especially suitable among the metal complexes in which the porphyrin-type compound coordinated. Cobalt complexes are unlikely to produce μ-oxodimer even when a chain transfer agent is used, so that the activity is rarely reduced. Therefore, it can be prepared in an air atmosphere. In addition, when the cobalt complex represented by the general formula (3) is applied, even if the amount of water added is 5 moles or more with respect to the catalyst, the reaction rate is not lowered. Can be reduced. Furthermore, the molecular weight calculated from the charged amount of the cobalt complex represented by the general formula (3) is a value close to the actually generated molecular weight.

<Second reaction step>
In the second reaction step, the alkylene oxide represented by the general formula (1) and the acid anhydride represented by the general formula (2) are copolymerized.

  In the second reaction step, it is sufficient that the metal complex according to the present invention is present at 0.1 mol% to 1 mol% with respect to the alkylene oxide. More preferably, it is a case where it is made to exist in 0.2 mol%-0.5 mol%.

  The temperature during the copolymerization reaction in the second reaction step is preferably controlled so as to be 120 ° C. or less, more preferably 20 ° C. or more and 120 ° C. or less, and further preferably 20 ° C. or more and 100 ° C. or less. Particularly preferably, it is 40 ° C. or higher and 80 ° C. or lower.

The second reaction step may be performed in a solvent or without a solvent.
When a solvent is used, the same solvent as described in the second reaction step can be used, and the preferred solvent and the preferred amount of solvent used are also the same.

  A Lewis base can also be used in the second reaction step. The reaction scheme when a Lewis acid is used is shown in the following scheme 6.

In the above reaction scheme 6, ^{R 1} has the same meaning as ^{R 1} in Formula (1), Z has the same meaning as Z in the general formula (2), BASE represents a Lewis base. In the first reaction step and the second reaction step, the compound represented by the general formula (1) may be the same or different.

  The amount of Lewis base used in the second reaction step is preferably 0.1 to 5 mol, preferably 0.5 to 0.75 mol, relative to 1 mol of the metal complex coordinated with the porphyrin compound. It is more preferable. If it is used within this range, the yield is not lowered, and it is difficult to produce cyclic carbonate (a compound in which alkylene oxide and acid anhydride are reacted by 1 mol each), and an alternating copolymer is produced. Moreover, it is difficult to produce a polyether reacted only with an alkylene oxide from the viewpoint of the reaction rate and the point that carbon dioxide is easily taken up.

Also in the second reaction step, a chain transfer agent having active hydrogen can be used.
The amount of the chain transfer agent used in the second reaction step is 1 mol or more with respect to 1 mol of the metal complex from the viewpoint of obtaining the desired number of molecules and molecular weight while reducing the amount of expensive metal complex used. The active hydrogen is preferably used so that it is present, more preferably 5 mol or more of active hydrogen is present, and still more preferably 10 mol or more of active hydrogen is present.

  In the second reaction step, the kind of chain transfer agent that can be used can be the same as that described in the first reaction step. Moreover, a metal catalyst suitable when a chain transfer agent is applied is a cobalt complex represented by the general formula (3).

<Method for producing block copolymer>
In the method for producing a block copolymer of the present invention, either the first reaction step or the second reaction step may be performed first, and the first reaction step and the second reaction step are repeated. You may go.
When switching between the first reaction step and the second reaction step, the porphyrin-based metal complex as a catalyst, a solvent, a Lewis base, and the like may be replaced, but from the viewpoint of simplifying the production process, It is preferable to use the same.

  For example, a reaction scheme when the first reaction step is first performed and then the second reaction step is performed is shown below.

In the first reaction step and the second reaction step, the compounds represented by the general formula (1) may be the same or different. That is, R ¹ in the general formula (1) may be the same or different in the first reaction step and the second reaction step.

  By combining the above reactions, the following various copolymers can be obtained. In the following polymers, the polycarbonate copolymer block obtained by the first reaction step is represented as A, and the polyester copolymer block obtained by the second reaction step is represented by B.

In addition, when a chain transfer agent having two or more active hydrogens in one molecule is used, the number of growth points of the polymer becomes two or more, so that the manufacturing process can be simplified.
That is, for example, in the case of producing the block copolymer (2), when a chain transfer agent is not used, after the copolymer block A is produced, the copolymer block B is produced, and then further copolymerization is performed. A three-stage process of producing the combined block A is required. On the other hand, if a chain transfer agent having two or more active hydrogens in one molecule is used, a copolymer block B having growth points at both ends can be prepared. If produced, an A-B-A block copolymer (2) can be obtained in a two-step process.

  A Brensted acid compound can be added to the obtained block copolymer to convert the terminal to a hydroxyl group, thereby stopping the reaction. This is shown in Scheme 8 below. In the following scheme 8, the case where no chain transfer agent is used is described. However, even in the case where a chain transfer agent is used, the point that the metal complex (catalyst) is replaced with a hydrogen atom is the same.

  The order of addition of the metal complex, alkylene oxide, Lewis base, and solvent used in the method of the present invention is not particularly limited. However, when a solvent is used, a solution in which the metal complex is dissolved in the solvent is prepared in advance. It is preferable to keep it.

  In addition, after completion of the copolymerization reaction, the metal complex taken into the copolymer is a method in which only one of the metal complex and the solution in which the copolymer is dissolved is precipitated, the solid state of the metal complex and the copolymer The metal complex can be removed by any method of extracting only one from the mixture.

  In this case, either a poor solvent for the copolymer that can dissolve the metal complex, a poor solvent for the metal complex that can dissolve the copolymer, or an acidic substance that reacts with the basic site of the metal complex to form a salt. Can be used. For example, methanol, hexane, etc. can be used as such a poor solvent.

<Copolymer>
By the production method of the present invention, a copolymer block of polycarbonate by a copolymerization reaction of carbon dioxide and the alkylene oxide represented by the general formula (1), and the alkylene oxide represented by the general formula (1) And a block copolymer of a polyester having a copolymer block obtained by a block copolymerization reaction of the acid anhydride represented by the general formula (2).

  When the production method of the present invention is not applied, the production ratio of unnecessary by-products is increased. For example, when the alkylene oxide represented by the general formula (1) is A, the acid anhydride represented by the general formula (2) is B, and the carbon dioxide is C, the obtained product is represented as follows: Byproducts such as those shown in the following structures (1) to (3) are easily generated.

  Structure (1) is a so-called cyclic carbonate or cyclic ester. The cyclic carbonate is a low molecular compound in which only one molecule of alkylene oxide and carbon dioxide is bonded, and the cyclic ester is a low molecular compound in which only one molecule of alkylene oxide and acid anhydride is bonded. . The thermal decomposition temperature of a copolymer containing a low molecular weight compound such as structure (1) is significantly reduced by the presence of the compound represented by structure (1).

  The structure (2) is a polymer obtained by ring-opening polymerization of only the alkylene oxide A of the general formula (1), and does not react with carbon dioxide or acid anhydride, and thus does not have a polycarbonate or polyester structure. From the viewpoint of effectively using carbon dioxide, the polymer of the structure (2) does not meet the purpose.

  In the structure (3), only the alkylene oxide is included in the block copolymer of the polycarbonate copolymer block having the repeating unit (AC) and the polyester copolymer block having the repeating unit (AB). There is a polyether moiety obtained by ring-opening polymerization. Since this polymer has a polyether part, it is inferior in biodegradability and the thermal decomposition temperature falls.

  On the other hand, in the manufacturing method of this invention, it is hard to produce | generate a by-product like the said structures (1)-(3).

Moreover, the block copolymer obtained by the production method of the present invention can have an alternating copolymerization ratio of 90% or more in any of the polycarbonate copolymer block and the polyester copolymer block. It can be 95% or more, and can be 99% or more.
Here, the alternating copolymerization ratio accounts for the number of carbonate bonds by the reaction of carbon dioxide and alkylene oxide and the number of ester bonds by the reaction of acid anhydride and alkylene oxide among the total number of bonds of the main chain in the copolymer. Say percentage. That is, a copolymer having a high alternating copolymerization ratio has a low content of polyether bonds in which only alkylene oxide is ring-opening polymerized.

Therefore, the alternating copolymerization ratio can be expressed as carbonate bond rate and ester bond rate. In ¹ H-NMR (CDCl ₃ ), the carbonate bond rate and the ester bond rate are the signals derived from methine hydrogen adjacent to the carbonate bond appearing near δ5.0 ppm and the methine hydrogen adjacent to the ester bond appearing near δ5.2 ppm. It can be calculated from the intensity ratio of the signal derived from methine hydrogen adjacent to the ether bond appearing near δ3.4 ppm.

  Moreover, in the manufacturing method of this invention, since the metal complex which concerns on this invention is used, the obtained copolymer has narrow molecular weight distribution. The ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn obtained by GPC measurement can be a copolymer having a ratio of 1.01 to 1.20. 1.15 can also be set, and Mw / Mn can be set to 1.01-1.10 depending on manufacturing conditions.

  In addition, since a part of the metal catalyst according to the present invention is also dissolved in supercritical carbon dioxide, the reaction is performed without using a solvent by increasing the carbon dioxide partial pressure during the reaction to supercritical carbon dioxide. be able to. As a result, the copolymer has a low content of unnecessary solvent.

  When water is applied as a chain transfer agent having active hydrogen in the above copolymer production method, both ends become a copolymer having a hydroxyl group. In addition, when not using a chain transfer agent, as shown in the said scheme 3, it has a substituent resulting from the metal salt of metal catalysts, such as a chlorine atom, in one terminal.

  Since the block copolymer whose both ends are hydroxyl groups is excellent in adhesiveness and biodegradable, it can be suitably used for a film for adhesive use.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

[Example 1]
(First reaction step)
In a stainless steel pressure vessel filled with nitrogen, 0.1 mmol of tetraphenylporfinatocobalt chloride [(TPP) CoCl] (the above structural formula (1)) as a metal complex and propylene oxide (PO) as an alkylene oxide. 50 mmol was used. These are added to 3.5 ml of dichloromethane containing 0.075 mmol of 4- (N, N-dimethylamino) pyridine (DMAP), carbon dioxide is injected under pressure so that the initial pressure of the reaction is 5 MPa. Adjusted.

  After 48 hours of heat reaction at 40 ° C., this was cooled to room temperature and then excess carbon dioxide was released.

(Second reaction step)
50 mmol of propylene oxide (PO) as an alkylene oxide and 50 mmol of succinic acid (SA) as an acid anhydride were added to the reaction solution obtained in the first reaction step.

  After heating and reacting at 80 ° C. for 7 days, this was cooled to room temperature, and 3.5 mL of methylene chloride was added to obtain the product.

[Examples 2-4, Reference Examples 1-2]
A copolymer was produced in the same manner as in Example 1 except that the addition amounts of propylene oxide (PO) and succinic acid (SA) in Example 1 were changed as shown in Table 1. The copolymer prepared in Reference Example 2 was applied to the first reaction step of Example 3.

(Average molecular weight)
The average molecular weight of the product obtained after the first reaction step and the average molecular weight of the product obtained after the second reaction step were analyzed by GPC. The results are shown in Table 1.

(Conversion rate)
The conversion rate of the product obtained after the first reaction step and the conversion rate of the product obtained after the second reaction step were determined by ¹ H-NMR. The results are shown in Table 1.

表１中の「−」は、該当していないことを意味する。

“-” In Table 1 means not applicable.

<Analysis>
(Polycarbonate and polyester content ratio (PC + PEs: CC))
The production ratio of PC (polycarbonate), PEs (polyester) and CC (cyclic carbonate) was determined from IR using a calibration curve prepared in advance. The results are shown in Table 2. In addition, it has been confirmed that almost no cyclic ester is produced when nothing is observed in the low molecular weight region except for catalyst residues when the GPC chromatogram of the product is observed.

(Carbonate bond rate and ester bond rate)
In ¹ H-NMR (CDCl ₃ ), the carbonate bond rate and the ester bond rate are the signals derived from methine hydrogen adjacent to the carbonate bond appearing near δ5.0 ppm and the methine hydrogen adjacent to the ester bond appearing near δ5.2 ppm. It can be calculated from the intensity ratio of the signal derived from methine hydrogen adjacent to the ether bond appearing near δ3.4 ppm.

From the analysis results, the polymer obtained is a block copolymer of a polycarbonate in which carbon dioxide and alkylene oxide react alternately, and a polyester in which acid anhydride and alkylene oxide react alternately to form a cyclic carbonate. The rate was less than 1%.
Furthermore, from the results obtained by detailed measurement by ¹ H-NMR, in all of Examples 1 to 4, the proportion of carbonate bonds is approximately the same as the amount estimated from the amount of charged alkylene oxide and carbon dioxide. It was.

<Purification>
In order to ensure the accuracy of measurement of the thermal decomposition temperature (Td) of the copolymers obtained in Example 1 and Example 2, the obtained product was purified by the following method, and the copolymer after purification was used. Td was measured for.
First, the product was reprecipitated with chloroform and methanol to isolate the polymer. The catalyst was removed from the isolated polymer by column chromatography. At this time, ethyl acetate was used as a developing solvent.
The polymer from which the catalyst was removed was reprecipitated again with chloroform and methanol. Thereafter, vacuum drying was performed.

(Polymer decomposition temperature after purification)
The decomposition temperature (Td) of the polymer after purification was determined by increasing the temperature from 25 ° C. to 550 ° C. at a rate of 10 ° C./min using a METTLER TOLEDO STAR ^e system (manufactured by METTLER TOLEDO). The results are shown in Table 3.

  The thermal decomposition temperatures of the copolymers of Examples 1 to 4 all exceeded 250 ° C. A copolymer having a heating temperature in a general injection molding machine of 250 ° C. and a thermal decomposition temperature higher than this is practically excellent.

[Example 5]
In Example 1, succinic acid (SA) was used as an acid anhydride, but in Example 5, a polymer was synthesized by changing to maleic anhydride (MA) and changing the compounding ratio as shown in Table 4.

  The obtained polymer was analyzed in the same manner as in Example 1. The results are shown in Table 5.

[Example 6]
In Example 6, a chain transfer agent was applied.
In a stainless steel pressure vessel filled with nitrogen, tetraphenylporphynatocobalt chloride [(TPP) CoCl] (the structural formula (1)) as a metal complex, 2-propanol as a chain transfer agent, and propylene as an alkylene oxide Using oxide (PO), such that the compounding molar ratio is 1/49/1000, and includes (TPP) CoCl and an equimolar amount of 4- (N, N-dimethylamino) pyridine (DMAP). It was added to dichloromethane, carbon dioxide was injected under pressure, and the initial pressure of the reaction was adjusted to 5 MPa.

  After heating at 40 ° C. for 96 hours, this was cooled to room temperature and then excess carbon dioxide was released.

  Then, the 2nd reaction process was performed like Example 1, and the reaction material was obtained. The appearance of the obtained reaction product was a sticky product.

[Example 7]
The polymer was synthesized in the same manner as in Example 6 except that 2-propanol in Example 6 was changed to benzyl alcohol, and the molar ratio of cobalt complex, benzyl alcohol, and propylene oxide was changed as shown in Table 6. did. The appearance of the obtained reaction product was a sticky product.

  Analytical evaluation of the reactants obtained in Examples 6 to 7 was performed in the same manner as in Example 1. The results are shown in Table 7.

In Examples 6 to 7, the molecular weight calculated from the sum of the molecules of the metal complex and the chain transfer agent was approximately the same as the actual number average molecular weight. The molecular weight distribution M _w / M _n was narrow.
In the examples, the ratio of the number of halogen terminals to the total number of terminals is not confirmed, but it can be estimated that the number of halogen terminals is reduced. In the present invention, theoretically, the ratio of the number of halogen terminals to the total number of terminals can be 0.25 or less, and the copolymers obtained in the examples also fall within this numerical range. I think.

Claims (26)

A first reaction step in which carbon dioxide and an alkylene oxide represented by the following general formula (1) are copolymerized in the presence of a metal complex coordinated with a porphyrin-based compound;
Second reaction in which an alkylene oxide represented by the following general formula (1) and an acid anhydride represented by the following general formula (2) are copolymerized in the presence of a metal complex coordinated with a porphyrin-based compound. Process,
The manufacturing method of the block copolymer characterized by having.

[In General Formula (1), R ¹ represents a hydrogen atom or a methyl group. In General Formula (2), Z represents a group that forms a 5-membered ring or a 6-membered ring. However, the alkylene oxide represented by the general formula (1) used in the second reaction step is the same as or different from the alkylene oxide represented by the general formula (1) used in the first reaction step. Also good. ]   The alkylene oxide represented by the general formula (1) is propylene oxide or ethylene oxide, and the acid anhydride represented by the general formula (2) is succinic anhydride. The manufacturing method of the block copolymer of description. The method for producing a block copolymer according to claim 1 or 2, wherein the metal complex coordinated with the porphyrin-based compound is a metal complex represented by the following general formula (3).

[In general formula (3), each R ³ independently represents a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert- A butyl group, a phenyl group, a methoxy group, an ethoxy group, a trifluoromethyl group, a fluorine atom, a chlorine atom, or a bromine atom is represented, and n represents any integer of 0 to 5. ]   The method for producing a block copolymer according to any one of claims 1 to 3, wherein a Lewis base is used in the first reaction step and the second reaction step.   In the first reaction step and the second reaction step, 0.1 to 5 mol of the Lewis base is used with respect to 1 mol of the metal complex coordinated with the porphyrin compound. The manufacturing method of the block copolymer of description.   In the first reaction step and the second reaction step, 0.5 to 0.75 mol of the Lewis base is used with respect to 1 mol of the metal complex coordinated with the porphyrin compound. 5. A method for producing a block copolymer according to 4.   The block copolymer according to any one of claims 4 to 6, wherein the Lewis base is a compound having a structure having a high electron-sharing property and having an unpaired electron. Method.   The method for producing a block copolymer according to claim 7, wherein the Lewis base is a pyridine compound or an imidazole compound. The method for producing a block copolymer according to claim 8, wherein the pyridine compound is represented by the following general formula (4).

[In General Formula (4), R ⁴ represents a methyl group, a formyl group, or a substituted amino group, and m represents an integer of 0 to 5. ]   The method for producing a block copolymer according to claim 9, wherein the pyridine-based compound is 4- (N, N-dimethylamino) pyridine. The method for producing a block copolymer according to claim 8, wherein the imidazole compound is represented by the following general formula (5).

[In General Formula (5), R ⁵ represents a substituted or unsubstituted alkyl group. ]   The method for producing a block copolymer according to claim 11, wherein the imidazole compound is N-methylimidazole.   The method for producing a block copolymer according to any one of claims 1 to 12, wherein a partial pressure of carbon dioxide in the first reaction step is 0.1 to 25 MPa.   The method for producing a block copolymer according to any one of claims 1 to 13, wherein in the first reaction step, a copolymerization reaction is performed in a temperature range of 0 ° C to 100 ° C. .   The method for producing a block copolymer according to any one of claims 1 to 14, wherein in the second reaction step, a copolymerization reaction is performed in a temperature range of 20 ° C to 120 ° C. .   16. The chain transfer agent having active hydrogen is used in at least one of the first reaction step and the second reaction step. 16. The method according to claim 1, wherein a chain transfer agent having active hydrogen is used. A method for producing a block copolymer.   The method for producing a block copolymer according to claim 16, wherein the chain transfer agent is used so as to contain 5 mol or more of the active hydrogen with respect to the metal complex coordinated with the porphyrin-based compound.   The method for producing a block copolymer according to claim 16 or 17, wherein the chain transfer agent having active hydrogen contains one or more active hydrogen groups in one molecule.   The method for producing a block copolymer according to claim 18, wherein the chain transfer agent having active hydrogen has one or more OH groups or COOH groups in one molecule.   The block transfer agent according to any one of claims 16 to 19, wherein the chain transfer agent having active hydrogen contains two or more active hydrogen groups in one molecule. Method.   The method for producing a block copolymer according to claim 20, wherein the chain transfer agent having active hydrogen is water.   The block copolymer obtained by the manufacturing method of any one of Claims 1-21. A polycarbonate block by a copolymerization reaction of carbon dioxide and an alkylene oxide represented by the following general formula (1), an alkylene oxide represented by the following general formula (1) and an acid represented by the following general formula (2) A block copolymer having a polyester block by a copolymerization reaction with an anhydride.

[In General Formula (1), R ¹ represents a hydrogen atom or a methyl group. In General Formula (2), Z represents a group that forms a 5-membered ring or a 6-membered ring. However, R ¹ of the alkylene oxide represented by the general formula (1) in the polycarbonate block may be the same as or different from R ^{1 of the} alkylene oxide represented by the general formula (1) in the polyester block. . ]   The block copolymer according to claim 22 or 23, wherein both ends are hydroxyl groups.   The block copolymer according to any one of claims 23 to 24, wherein an alternating copolymerization ratio of the polycarbonate block and the polyester block is 95% or more.   The block copolymer according to any one of claims 22 to 25, wherein the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn is 1.01 or more and 1.20 or less. .