Polycarbonate and method for producing the same

Abstract

This polycarbonate is either: a polycarbonate synthesized from the reaction of at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide (ISB)), ISB, and a compound represented by formula 1 (excluding a polycarbonate which is a reaction product of 1,3:4,6-Di-O-benzylidene-D-mannitol (DBM), ISB, and diphenyl carbonate, in which the ratio of the structure based on DBM to the sum of the structure based on DBM and the structure based on ISB is less than 10 mol%); or a polycarbonate which is a reaction product of at least one polyhydric alcohol derived from sugar alcohol (excluding ISB) and a compound represented by formula 1. R1 and R2 are each independently an organic group.

Description

Polycarbonate and its manufacturing method

[0001] The present invention relates to a polycarbonate and a method for producing the same. This application claims priority to Japanese Patent Application No. 2023-206806, filed on December 7, 2023, the contents of which are incorporated herein by reference.

[0002] Polycarbonate is an engineering plastic that is widely used in many fields due to its excellent heat resistance, impact resistance, transparency, etc. Known methods for producing polycarbonate include the phosgene method and the transesterification method. In the transesterification method, polycarbonate is produced by reacting a carbonate ester such as diphenyl carbonate with a polyvalent hydroxy compound. The transesterification method does not require the use of toxic phosgene, and is therefore preferable in terms of the environment, production facilities, etc.

[0003] Polycarbonates are generally produced using raw materials derived from petroleum resources. However, in recent years, from the perspective of carbon neutrality, there has been a demand for using raw materials derived from biomass resources such as plants. As a polycarbonate made from a raw material derived from a biomass resource, polycarbonate made from plant-derived isosorbide is known. Furthermore, Non-Patent Document 1 describes the production of polycarbonate by melt polymerization of diphenyl carbonate, isosorbide, and 1,3:4,6-di-O-benzylidene-D-mannitol derived from a sugar alcohol.

[0004] Polymer Chemistry, 2023, 14, 2469

[0005] Non-Patent Document 1 discloses that it was impossible to introduce 10 mol % or more of a structure based on 1,3:4,6-di-O-benzylidene-D-mannitol into polycarbonate. This is thought to be due to the bulkiness and low reactivity of 1,3:4,6-di-O-benzylidene-D-mannitol. Polyhydric alcohols derived from sugar alcohols other than 1,3:4,6-di-O-benzylidene-D-mannitol (excluding isosorbide) also tend to have lower reactivity than isosorbide, similar to 1,3:4,6-di-O-benzylidene-D-mannitol. For this reason, it has been difficult to obtain polycarbonates containing a high content of a structure based on a polyhydric alcohol derived from a sugar alcohol (excluding isosorbide). Furthermore, when diphenyl carbonate is used, high temperatures are required to promote the reaction; even in Non-Patent Document 1, polymerization is carried out at 220°C. High polymerization temperatures raise concerns about quality degradation, such as coloration.

[0006] The present invention provides a novel polycarbonate using a polyhydric alcohol derived from a biomass resource and a method for producing the same.

[0007] The present invention has the following aspects: [1] A polycarbonate which is a reaction product of at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide), isosorbide, and a compound represented by the following formula 1 (excluding polycarbonates synthesized by reacting 1,3:4,6-di-O-benzylidene-D-mannitol, isosorbide, and diphenyl carbonate, in which the proportion of the 1,3:4,6-di-O-benzylidene-D-mannitol-based structure to the total of the 1,3:4,6-di-O-benzylidene-D-mannitol-based structure and the isosorbide-based structure is less than 10 mol %). However, R １ and R ２ [2] A polycarbonate which is a reaction product of at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide) and a compound represented by the following formula 1: However, R １ and R ２are each independently an organic group. [3] The polycarbonate according to [1] or [2], wherein the polyhydric alcohol (excluding isosorbide) is a dihydric alcohol. [4] The polycarbonate according to any one of [1] to [3], wherein the polyhydric alcohol (excluding isosorbide) is a dihydric alcohol in which (the valence of the sugar alcohol minus 2) hydroxyl groups out of the hydroxyl groups of a trihydric or higher sugar alcohol are protected with protecting groups. [5] The polycarbonate according to [4], wherein the protecting group is at least one selected from the group consisting of a divalent organic group and a monovalent organic group, the divalent organic group being at least one selected from the group consisting of a substituted or unsubstituted alkylene group and a substituted or unsubstituted arylene group, and the monovalent organic group being at least one selected from the group consisting of a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group. [6] The polycarbonate according to [4] or [5], wherein the trihydric or higher hydric sugar alcohol is a hexahydric sugar alcohol or a pentahydric sugar alcohol. [7] The polycarbonate according to any one of [4] to [6], wherein the trihydric or higher hydric sugar alcohol is mannitol or sorbitol. [8] The polycarbonate according to any one of [1] to [7], wherein the polyhydric alcohol (excluding isosorbide) is selected from the group consisting of compounds represented by the following formula 2, the following formula 3, and the following formula 3a: However, R ３ , R ４ , R ５ and R ６ are each independently a hydrogen atom or a substituent, and in formula 3a, R ３ , R ４ , R ５ and R ６[9] The polycarbonate according to [8], wherein the substituent is at least one selected from the group consisting of an alkoxy group, an aryl group, an amino group, a silyl group, a hydroxy group, an allyl group, a carboxy group, an alkyl group, a cycloalkyl group, and a cyano group.

[10] The polycarbonate according to any one of [1] to [9], wherein the polyhydric alcohol (excluding isosorbide) contains 1,3:4,6-di-O-benzylidene-D-mannitol.

[11] The polycarbonate according to any one of [1] to

[10] , wherein the weight-average molecular weight is 20,000 or more.

[12] The polycarbonate according to any one of [1] to

[10] , wherein the R in formula 1 １ and R ２ are each independently an organic group containing a fluorine atom. [12-1] The polycarbonate according to any one of [1] to

[12] , wherein the weight average molecular weight is preferably 10,000 or more and 100,000 or less, more preferably 15,000 or more and 70,000 or less, and even more preferably 20,000 or more and 60,000 or less. [12-2] The polycarbonate according to any one of [1] to [12-1], wherein the molecular weight dispersity, expressed as weight average molecular weight / number average molecular weight, is preferably 5.0 or less, more preferably 3.0 or less.

[0008]

[13] A method for producing a polycarbonate, comprising reacting at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide), isosorbide, and a compound represented by the following formula 4: However, R ｆ１ and R ｆ２

[14] A method for producing a polycarbonate, comprising reacting at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide) with a compound represented by the following formula 4: However, R ｆ１ and R ｆ２and each independently represent an organic group containing a fluorine atom.

[15] The production method according to

[13] , comprising reacting the polyhydric alcohol (excluding isosorbide), the isosorbide, and the compound represented by formula 4 in the presence of a condensation catalyst, heating the resulting prepolymer at a temperature below its melting temperature, and solid-state polymerizing the prepolymer while discharging the by-product fluorine-containing alcohol out of the system.

[16] The production method according to

[14] , comprising reacting the polyhydric alcohol (excluding isosorbide) and the compound represented by formula 4 in the presence of a condensation catalyst, heating the resulting prepolymer at a temperature below its melting temperature, and solid-state polymerizing the prepolymer while discharging the by-product fluorine-containing alcohol out of the system.

[17] The production method according to

[15] or

[16] , wherein the temperature during solid-state polymerization of the prepolymer is 200°C or lower.

[0009]

[18] The polycarbonate or production method according to any one of

[12] to

[17] , wherein the fluorine atom-containing organic group is at least one selected from the group consisting of Group 5, Group 6, and Group 7 below:

[0010]

[0011] (However, R ５ is CA １ B １ R １４ R is a group represented by ６ is CA ２ B ２ R １５ R is a group represented by ７ is a hydrogen atom or CA ３ B ３ R １６ A is a group represented by the formula: １ , A ２ and A ３ are each independently a hydrogen atom, a fluorine atom or R ｆ And B １ , B ２ and B ３ are each independently a hydrogen atom, a fluorine atom or R ｆ and R １４ , R １５ and R １６are each independently a fluorine atom, R ｆ or OR ｆ and R ｆ R is a fluoroalkyl group having 1 to 12 carbon atoms or a fluoroaryl group having 6 to 10 carbon atoms, and the fluoroalkyl group having 1 to 12 carbon atoms may have some of its carbon atoms substituted with oxygen atoms. ８ is a perfluoroalkylene group having 1 to 5 carbon atoms, and some of the carbon atoms in the perfluoroalkylene group having 1 to 5 carbon atoms may be substituted with oxygen atoms. ９ , R １０ , R １１ , R １２ and R １３ are each independently a hydrogen atom, a fluorine atom, or a fluoroalkyl group having 1 to 6 carbon atoms, and the fluoroalkyl group having 1 to 6 carbon atoms may have some of its carbon atoms substituted with oxygen atoms; R ９ , R １０ , R １１ , R １２ and R １３ At least one of the formulas is a fluorine atom or a fluoroalkyl group having 1 to 6 carbon atoms.)

[19] The compound represented by formula 1 or formula 4 is bis(1,1,1,3,3,3-hexafluoroisopropyl)carbonate, ((CF ３ CF ２ ) (CF ３ ) CHO) ２ CO, ((CF ３ CF ２ ) ２ CHO) ２The polycarbonate or production method according to any one of [1] to

[18] , wherein the carbonyl group is at least one selected from the group consisting of CO, bis(perfluoro(t-butyl))carbonate, bis(2,2,3,3,4,4,5,5-octafluorocyclopentyl)carbonate, bis(2,2,3,3,4,4,5,5,6,6-decafluorocyclohexyl)carbonate, bis(perfluorophenyl)carbonate, bis(m-trifluoromethylphenyl)carbonate, bis(o-trifluoromethylphenyl)carbonate, and bis(p-trifluoromethylphenyl)carbonate, and is preferably bis(1,1,1,3,3,3-hexafluoroisopropyl)carbonate, bis(perfluoro(t-butyl))carbonate, or bis(2,2,3,3,4,4,5,5,6,6-decafluorocyclohexyl)carbonate.

[0012] According to the present invention, it is possible to provide a novel polycarbonate using a polyhydric alcohol derived from a biomass resource and a method for producing the same.

[0013] In this specification, a compound represented by Formula 1 will be referred to as Compound 1. Compounds represented by other formulas will also be referred to in the same manner. In this specification, isosorbide (1,4:3,6-dianhydro-D-sorbitol) will also be referred to as ISB. In this specification, 1,3:4,6-di-O-benzylidene-D-mannitol will also be referred to as DBM. The meanings and definitions of terms used in the present invention are as follows. An "etheric oxygen atom" refers to an oxygen atom that forms an ether bond. A "solid-state polymerization method" refers to a polymerization method in which a prepolymer is polymerized while maintaining the prepolymer in a solid state to obtain a high-molecular-weight polycarbonate. A "prepolymer" refers to a solid intermediate product obtained by stopping the reaction of polycarbonate raw materials (polyhydric hydroxy compound, carbonate ester) at an appropriate point, and refers to a polycarbonate with a lower weight-average molecular weight than the high-molecular-weight polycarbonate obtained by solid-state polymerization. A "melting temperature of a prepolymer" refers to the temperature at which a prepolymer melts, becomes liquid, or softens. The melting temperature is determined by heating the prepolymer to a predetermined temperature and visually observing the temperature at which it becomes liquid or softens. "Weight average molecular weight" and "number average molecular weight" are values ​​measured by gel permeation chromatography (GPC) in terms of standard polystyrene. "Glass transition temperature" is the midpoint glass transition temperature measured by differential scanning calorimetry (DSC) in accordance with JIS K 7121:1987. "Crystallization" refers to performing an operation to increase the crystallinity of a polymer. "Perfluoroalkylene group" refers to a group in which all hydrogen atoms of an alkylene group are substituted with fluorine atoms. "Fluoroalkyl group" refers to a group in which some or all hydrogen atoms of an alkyl group are substituted with fluorine atoms. The "to" symbol indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0014] [Polycarbonate (1)] The polycarbonate according to the first embodiment of the present invention (hereinafter also referred to as polycarbonate (1)) is a reaction product of ISB, at least one polyhydric alcohol derived from a sugar alcohol (excluding ISB) (hereinafter also referred to as polyhydric alcohol A), and compound 1 (excluding polycarbonates synthesized by the reaction of ISB, DBM, and diphenyl carbonate, in which the proportion of DBM-based structures to the total of ISB-based structures and DBM-based structures is less than 10 mol %). Polyhydric alcohol A and compound 1 will be described in detail later.

[0015] However, R １ and R ２ are each independently an organic group.

[0016] The polycarbonate (1) typically has a main chain composed of units u1 and u2. The units u1 in the main chain may be of one type or two or more types.

[0017] Here, R is a residue obtained by removing two hydroxyl groups from polyhydric alcohol A.

[0018] The oxygen atom (—O—) of the unit u1 or unit u2 located at the end of the main chain of the polycarbonate (2) is typically bonded to a hydrogen atom, but may be substituted with other groups or atoms. The carbon atom of the carbonyl group of the unit u1 or unit u2 located at the end of the main chain of the polycarbonate (2) is typically bonded to a group represented by R １ or R ２ is bonded to, but may be substituted with other groups or atoms.

[0019] The proportion (mol %) of units u1 to the total of units u1 and units u2 corresponds to the proportion (mol %) of structures based on polyhydric alcohol A to the total of structures based on polyhydric alcohol A and structures based on ISB in polycarbonate (1). When 1,4:3,6-dianhydro-D-mannitol (i.e., isomannide (hereinafter also referred to as IMN)), which is an optical isomer of ISB described below, is contained, this is to be read as the proportion (mol %) of structures based on polyhydric alcohol A excluding ISB and IMN to the total of structures based on polyhydric alcohol A excluding ISB and IMN and structures based on ISB and IMN.

[0020] The proportion of the polyhydric alcohol A-based structure relative to the total of the polyhydric alcohol A-based structure and the ISB-based structure in the polycarbonate (1) is, for example, 1 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more. The upper limit is not particularly limited, but may be, for example, 99 mol% or less, further 95 mol% or less, further 90 mol% or less, further 50 mol% or less, further 40 mol% or less, or even 30 mol% or less. The lower limit and the upper limit can be appropriately combined. For example, the proportion of the polyhydric alcohol A-based structure is preferably 1 mol% or more and 99 mol% or less, more preferably 5 mol% or more and 95 mol% or less, more preferably 5 mol% or more and 90 mol% or less, more preferably 7 mol% or more and 50 mol% or less, even more preferably 10 mol% or more and 40 mol% or less, and even more preferably 10 mol% or more and 30 mol% or less. However, in polycarbonate (1), when polyhydric alcohol A is DBM and compound 1 is diphenyl carbonate, the proportion of structures based on the polyhydric alcohol A is 10 mol % or more. The higher the proportion of structures based on the polyhydric alcohol A other than ISB and IMN, the more diverse functionalities can be imparted. For example, when a polyhydric alcohol A in which some of the hydroxyl groups of a trihydric or higher sugar alcohol are protected with protecting groups is used as the polyhydric alcohol A, a polycarbonate with a high content of hydroxyl groups or functional groups can be obtained by deprotecting the polyhydric alcohol after polymerization or by introducing functional groups into the hydroxyl groups generated by deprotection.

[0021] The weight-average molecular weight of polycarbonate (1) is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 20,000 or more, and is preferably 100,000 or less, more preferably 70,000 or less, and even more preferably 60,000 or less. The lower limit and the upper limit can be combined as appropriate. If the weight-average molecular weight is equal to or greater than the lower limit, the heat resistance, rigidity, and toughness are superior, and if it is equal to or less than the upper limit, the molding processability is superior. The molecular weight dispersity, expressed as the weight-average molecular weight / number-average molecular weight of polycarbonate (1), is preferably 5.0 or less, more preferably 3.0 or less, from the viewpoint of ease of production of the polycarbonate.

[0022] The polycarbonate (1) can be produced, for example, by the production method (1) described below.

[0023] (Polyhydric alcohol A) Polyhydric alcohol A is a compound derived from a sugar alcohol and has two or more hydroxyl groups in one molecule. Examples of polyhydric alcohol A include sugar alcohols and sugar alcohol derivatives. Examples of sugar alcohol derivatives include compounds in which some of the hydroxyl groups of a sugar alcohol are protected with protecting groups.

[0024] From the viewpoint of ease of production of polycarbonate, the polyhydric alcohol A is preferably a dihydric alcohol having two hydroxyl groups per molecule. Sugar alcohols are typically trivalent or higher. Therefore, the polyhydric alcohol A is preferably a dihydric alcohol in which (the hydroxyl number of the sugar alcohol - 2) of the hydroxyl groups of a trivalent or higher sugar alcohol are protected with protecting groups.

[0025] Examples of dihydric polyhydric alcohols include isomannide (IMN) and isoidide. Examples of trihydric or higher hydric sugar alcohols include trihydric sugar alcohols such as glycerin; tetrahydric sugar alcohols such as tetritol; pentahydric sugar alcohols such as pentitol; hexahydric sugar alcohols such as hexitol; heptahydric sugar alcohols such as heptitol; octahydric sugar alcohols such as octitol; and nonahydric or higher hydric sugar alcohols such as isomalt, lactitol, and maltitol. Examples of tetritols include erythritol. Examples of pentitols include xylitol. Examples of hexitols include mannitol and sorbitol. Examples of heptitols include volemitol. Examples of octitols include D-erythro-D-galactooctitol. Among these, from the viewpoint of ease of production of polycarbonate, hexahydric sugar alcohols or pentahydric sugar alcohols are preferred, hexitol is more preferred, and mannitol or sorbitol is even more preferred.

[0026] The protecting group may be a known protecting group for a hydroxyl group. Examples of the protecting group include organic groups such as a monovalent organic group and a divalent organic group. A divalent organic group bridges two hydroxyl groups to form a crosslinked structure. These organic groups can be appropriately combined depending on the number of hydroxyl groups to be protected in the sugar alcohol.

[0027] Examples of monovalent organic groups include substituted or unsubstituted alkyl groups and substituted or unsubstituted aryl groups. The unsubstituted alkyl groups may be linear, branched, or cyclic, or a combination thereof. The unsubstituted alkyl groups may have, for example, 1 to 20 carbon atoms. Specific examples of unsubstituted alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and ter-butyl groups. Examples of substituents in substituted alkyl groups include alkoxy groups, aryl groups, amino groups, silyl groups, hydroxy groups, allyl groups, carboxy groups, alkyl groups, cycloalkyl groups, and cyano groups. The unsubstituted aryl groups may have, for example, 6 to 20 carbon atoms. Specific examples of unsubstituted aryl groups include phenyl groups, naphthyl groups, biphenyl groups, ter-phenyl groups, and anthryl groups. Examples of substituents in substituted aryl groups include alkyl groups, alkoxy groups, aryl groups, amino groups, silyl groups, hydroxy groups, allyl groups, carboxy groups, and cyano groups. Examples of the alkyl group as a substituent and the alkyl group in the alkoxy group include the same as the substituted or unsubstituted alkyl group described above. Examples of the aryl group as a substituent include the same as the substituted or unsubstituted aryl group described above.

[0028] Examples of divalent organic groups include substituted or unsubstituted alkylene groups and substituted or unsubstituted arylene groups. The unsubstituted alkylene group may be linear, branched, or cyclic, or a combination thereof. The unsubstituted alkylene group may have, for example, 1 to 20 carbon atoms. Specific examples of unsubstituted alkyl groups include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, sec-butylene, and ter-butylene groups. Examples of substituents in the substituted alkylene group include the same as the substituents in the substituted alkyl group described above. The unsubstituted arylene group may have, for example, 6 to 20 carbon atoms. Specific examples of unsubstituted arylene groups include phenylene, naphthylene, biphenylene, ter-phenylene, and anthrylene groups. Examples of substituents in the substituted arylene group include the same as the substituents in the substituted aryl group described above. Specific examples of the divalent organic group include an ethylidene group, an isopropylidene group, a cyclohexylidene group, and a benzylidene group.

[0029] From the viewpoint of ease of production, the polyhydric alcohol A is preferably at least one compound A-1 selected from the group consisting of compound 2, compound 3, and compound 3a. Compound 2, compound 3, and compound 3a are each obtained by protecting two of the four hydroxyl groups of a hexitol (e.g., mannitol, sorbitol, etc.) with a substituted or unsubstituted methylene group. By increasing the ratio of compound A-1 to the total amount of compound A-1, ISB, and IMN, the amount of functional groups imparted can be increased, and it is expected that a material with excellent functionality can be obtained.

[0030] However, R ３ ~R ６ are each independently a hydrogen atom or a substituent. ３ ~R ６ At least three of these are substituents.

[0031] R ３ ~R ６The substituents in the above-mentioned alkylene group may be the same as those in the above-mentioned substituted alkylene group. Specific examples of Compound A-1 (Compound 2, Compound 3, or Compound 3a) include DBM (R ３ and R ４ is a phenyl group), 1,3:4,6-di-O-isopropylidene-D-mannitol (hereinafter also referred to as ADM), 1,3:4,6-di-O-(1-methylethylidene-D-mannitol, 1,3:4,6-di-O-cyclohexylidene-D-mannitol (hereinafter also referred to as CDM), 1,2:5,6-di-O-ethylidene-D-mannitol, 1,2:5,6-di-O-isopropylidene-D-mannitol, and 1,2:5,6-di-O-cyclohexylidene-D-mannitol. Among these, DBM is preferred from the viewpoint of thermal stability. The polyhydric alcohol A may be used alone or in combination of two or more types.

[0032] (Compound 1) In formula 1, R １ and R ２ The organic group in may be the same as the organic group contained in known carbonate esters. The organic group may be an organic group that does not contain a fluorine atom, but is preferably an organic group that contains a fluorine atom. When the organic group contains a fluorine atom, the reactivity of Compound 1 is improved compared to when the organic group does not contain a fluorine atom. Therefore, even if the ratio of polyhydric alcohol A to the total of polyhydric alcohol A and ISB is high, the reaction proceeds well.

[0033] Examples of the organic group not containing a fluorine atom include aryl groups such as a phenyl group, and alkyl groups such as a methyl group. Examples of the organic group containing a fluorine atom include Group 5, Group 6, and Group 7.

[0034]

[0035] However, R ５ is CA １ B １ R １４ R ６ is CA ２ B ２ R １５R is a group represented by ７ is a hydrogen atom or CA ３ B ３ R １６ A is a group represented by the formula: １ , A ２ and A ３ are each independently a hydrogen atom, a fluorine atom or R ｆ And B １ , B ２ and B ３ are each independently a hydrogen atom, a fluorine atom or R ｆ and R １４ , R １５ and R １６ are each independently a fluorine atom, R ｆ or OR ｆ and R ｆ R is a fluoroalkyl group having 1 to 12 carbon atoms or a fluoroaryl group having 6 to 10 carbon atoms, and the fluoroalkyl group having 1 to 12 carbon atoms may have some of its carbon atoms substituted with oxygen atoms. ８ is a perfluoroalkylene group having 1 to 5 carbon atoms, and some of the carbon atoms in the perfluoroalkylene group having 1 to 5 carbon atoms may be substituted with oxygen atoms. ９ , R １０ , R １１ , R １２ and R １３ are each independently a hydrogen atom, a fluorine atom, or a fluoroalkyl group having 1 to 6 carbon atoms, and the fluoroalkyl group having 1 to 6 carbon atoms may have some of its carbon atoms substituted with oxygen atoms; R ９ , R １０ , R １１ , R １２ and R １３ At least one of the groups is a fluorine atom or the above-mentioned fluoroalkyl group having 1 to 6 carbon atoms.

[0036] Compound 1 includes R １ and R ２ are each independently Group 5, １ and R ２ a compound in which one of R is group 5 and the other is group 6; １ and R２ are each independently Group 6, or R １ and R ２ are each independently a group 7. １ and R ２ are each independently a group 5, more preferably.

[0037] Specific examples of Compound 1 include bis(1,1,1,3,3,3-hexafluoroisopropyl)carbonate, ((CF ３ CF ２ ) (CF ３ ) CHO) ２ CO, ((CF ３ CF ２ ) ２ CHO) ２ Examples of the carbonate include CO, bis(perfluoro(t-butyl))carbonate, bis(2,2,3,3,4,4,5,5-octafluorocyclopentyl)carbonate, bis(2,2,3,3,4,4,5,5,6,6-decafluorocyclohexyl)carbonate, bis(perfluorophenyl)carbonate, bis(m-trifluoromethylphenyl)carbonate, bis(o-trifluoromethylphenyl)carbonate, and bis(p-trifluoromethylphenyl)carbonate.

[0038] As the compound 1, bis(1,1,1,3,3,3-hexafluoroisopropyl)carbonate, bis(perfluoro(t-butyl))carbonate, or bis(2,2,3,3,4,4,5,5,6,6-decafluorocyclohexyl)carbonate is preferred in terms of the transesterification reaction rate.

[0039] As the compound 1, bis(1,1,1,3,3,3-hexafluoroisopropyl)carbonate is particularly preferred from the viewpoints of availability of raw materials, ease of production of a fluorinated carbonate, and ability to produce a high molecular weight polycarbonate.

[0040] [Polycarbonate (2)] The polycarbonate according to the second embodiment of the present invention (hereinafter also referred to as polycarbonate (2)) is a reaction product of polyhydric alcohol A and compound 1. Polyhydric alcohol A and compound 1 are as described above.

[0041] Polycarbonate (2) typically has a main chain consisting of units u1.

[0042] Here, R is a residue obtained by removing two hydroxyl groups from polyhydric alcohol A.

[0043] The unit u1 in the polycarbonate (2) may be of one type or two or more types. The oxygen atom (—O—) of the unit u1 located at the end of the main chain of the polycarbonate (2) is typically bonded to a hydrogen atom, but may be substituted with another group or atom. The carbon atom of the carbonyl group of the unit u1 located at the end of the main chain of the polycarbonate (2) is typically bonded to a group such as R １ or R ２ is bonded to, but may be substituted with other groups or atoms.

[0044] The weight-average molecular weight of the polycarbonate (2) is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 20,000 or more, and is preferably 100,000 or less, more preferably 70,000 or less, and even more preferably 60,000 or less. The lower limit and the upper limit can be combined as appropriate. If the weight-average molecular weight is equal to or greater than the lower limit, the heat resistance, rigidity, and toughness are superior, and if it is equal to or less than the upper limit, the molding processability is superior. The molecular weight dispersity, expressed as the weight-average molecular weight / number-average molecular weight of the polycarbonate (2), is preferably 5.0 or less, more preferably 3.0 or less, from the viewpoint of ease of production.

[0045] The polycarbonate (2) can be produced, for example, by the production method (2) described below.

[0046] [Polycarbonate Production Method (1)] In the polycarbonate production method according to the third embodiment of the present invention (hereinafter also referred to as production method (1)), polyhydric alcohol A, ISB, and compound 4 are reacted.

[0047] However, R ｆ１ and R ｆ２ are each independently an organic group containing a fluorine atom.

[0048] In formula 4, R ｆ１ and R ｆ２ The organic group containing a fluorine atom in R １ and R ２ The organic group containing a fluorine atom in the above formula (I) is exemplified.

[0049] When polyhydric alcohol A, ISB, and compound 4 are reacted, a polycondensation reaction proceeds due to transesterification between polyhydric alcohol A or ISB and compound 4, and polycarbonate is synthesized. ｆ１ OH or R ｆ２ OH) is discharged outside the system.

[0050] Methods for reacting polyhydric alcohol A, ISB, and compound 4 include known methods such as melt polymerization and solid-state polymerization. Among these, solid-state polymerization is preferred. In solid-state polymerization, the polymerization temperature is relatively low, and therefore the quality of the resulting polycarbonate is excellent.

[0051] In the solid-state polymerization method, for example, polyhydric alcohol A, ISB, and compound 4 are reacted in the presence of a condensation catalyst (step a), and the resulting prepolymer is heated at a temperature below its melting point to solid-state polymerize the prepolymer while discharging the by-produced fluorine-containing alcohol out of the system (step b).

[0052] (Condensation catalyst) Examples of the condensation catalyst include basic transesterification catalysts. Examples of the basic transesterification catalyst include nitrogen-containing compounds, alkali metal compounds, and alkaline earth metal compounds. Examples of the nitrogen-containing compounds include amines, quaternary ammonium hydroxides, and salts of amines. Examples of the alkali metal compounds or alkaline earth metal compounds include organic acid salts, inorganic salts, oxides, hydroxides, hydrides, and alkoxides of alkali metals or alkaline earth metals. One type of condensation catalyst may be used alone, or two or more types may be used in combination. As the condensation catalyst, amines are preferred because they have high polymerization activity and are highly applicable to solution polymerization for producing prepolymers.

[0053] Specific examples of the nitrogen-containing compound include tertiary amines (triethylamine, tripropylamine, tributylamine, triisoamylamine, trihexylamine, triheptylamine, trioctylamine, tridodecylamine, etc.), secondary amines (diethylamine, dibutylamine, etc.), primary amines (propylamine, butylamine, etc.), imidazoles (2-methylimidazole, 2-phenylimidazole, benzimidazole, etc.), and quaternary ammonium hydroxides having an alkyl group and / or an aryl group, etc. (tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, etc.).

[0054] Specific examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenylborohydride, sodium phenylborohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, disodium phenylphosphate, sodium gluconate, disodium salt, dipotassium salt, dicesium salt and dilithium salt of bisphenol A, and sodium salt, potassium salt, cesium salt and lithium salt of phenol.

[0055] Specific examples of alkaline earth metal compounds include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, and magnesium phenylphosphate.

[0056] (Step a) A prepolymer is obtained by reacting a polyhydric alcohol A, ISB, and compound 4 in the presence of a condensation catalyst. Specifically, for example, after reacting a polyhydric alcohol A, ISB, and compound 4 in the presence of a condensation catalyst, the by-produced fluorine-containing alcohol (R ｆ１ OH or R ｆ２ The polyhydric alcohol A, ISB, and compound 4 are reacted in a solvent. In this case, the solvent is distilled off together with the by-produced fluorine-containing alcohol after the reaction.

[0057] Examples of the solvent include acetonitrile, N,N-dimethylformamide (DMF), 1,4-dioxane, dichloromethane, chloroform, chlorobenzene, etc. In terms of the solubility of the raw materials, acetonitrile, DMF, and chlorobenzene are preferred as the solvent.

[0058] The ratio of polyhydric alcohol A to the total of polyhydric alcohol A and ISB in step a is appropriately determined depending on the ratio of the structure based on polyhydric alcohol A to the total of the structure based on polyhydric alcohol A and the structure based on ISB in polycarbonate (1).

[0059] In step a, the ratio of compound 4 per mole of the total of polyhydric alcohol A and ISB is preferably 1 to 2 moles, more preferably 1 to 1.3 moles, and particularly preferably 1.02 to 1.2 moles. When the ratio of compound 4 is within the above range, the structure (R ｆ１ or R ｆ２ ) at the end of the main chain. As will be described later, the prepolymer having the structure derived from Compound 4 at the end is likely to undergo solid-state polymerization without crystallization of the prepolymer. Furthermore, solid-state polymerization proceeds even at a temperature below the glass transition temperature of the prepolymer.

[0060] The weight-average molecular weight of the prepolymer is preferably 500 to 15,000, more preferably 500 to 10,000, and particularly preferably 1,000 to 10,000. When the weight-average molecular weight of the prepolymer is within this range, the prepolymer is in a powder state, and the solid-state polymerization in step b is likely to proceed.

[0061] The glass transition temperature of the prepolymer is preferably 60° C. or higher, more preferably 70° C. or higher, and particularly preferably 80° C. or higher. The glass transition temperature of the prepolymer is preferably 160° C. or lower. When the glass transition temperature of the prepolymer is equal to or higher than the above-mentioned lower limit and equal to or lower than the above-mentioned upper limit, the prepolymer does not melt, and the solid-state polymerization in step b is likely to proceed at a low temperature.

[0062] In the prepolymer obtained in step a, the terminal group (R ｆ１ or R ｆ２The molar ratio of the hydroxyl end groups derived from compound 4 to the hydroxyl end groups derived from polyhydric alcohol A or ISB (end groups derived from compound 4 / end groups derived from hydroxyl end groups) is preferably 0.8 / 1 to 1.4 / 1, more preferably 0.9 / 1 to 1.3 / 1, and particularly preferably 0.95 / 1 to 1.25 / 1. When the content of the end groups derived from compound 4 is equal to or greater than the above lower limit, it is possible to prevent the hydroxyl end concentration of the polycarbonate obtained by solid-state polymerization in step b from increasing. When the content of the end groups derived from compound 4 is equal to or less than the above upper limit, it is easy to obtain a polycarbonate with a sufficiently high molecular weight. In this specification, the above molar ratio of the end groups of the polymer (including prepolymers and high-molecular-weight polycarbonates) is the molar ratio of the end groups of the polymer. １ It is preferable to analyze by H-NMR analysis. １ The H-NMR analysis method is as described in the examples of WO 2014 / 171367.

[0063] When the reaction in step a is carried out in a solvent, the prepolymer is obtained in the form of a solution. In this case, it is preferable to isolate a solid prepolymer by distilling off the solvent and the by-produced fluorine-containing alcohol. It is also preferable to vacuum-dry the isolated solid prepolymer at a low temperature to remove the remaining solvent, etc. The prepolymer may be, for example, in a powdery or candy-like state. In terms of facilitating the solid-phase polymerization in step b, the powdery state is preferred. The powdery prepolymer can be obtained, for example, by powdering the solid prepolymer obtained as described above. Various known methods can be used for powdering, for example, mechanical pulverization, mechanical pulverization under freezing, etc.

[0064] The average particle size of the powdered prepolymer is preferably 0.1 μm to 1 mm, more preferably 1 μm to 500 μm, and particularly preferably 3 μm to 200 μm. When the average particle size is within this range, the powdered prepolymer can be obtained by a simple operation. In addition, the solid-state polymerization in step (b) can proceed easily.

[0065] (Step b) Without going through a step of crystallizing the prepolymer, the prepolymer is heated at a temperature below its melting point, and the prepolymer is solid-phase polymerized while the by-product fluorine-containing alcohol is discharged out of the system to obtain a polycarbonate.

[0066] The heating temperature is lower than the melting temperature of the prepolymer, and is preferably 200°C or lower, more preferably 195°C or lower. If the heating temperature is lower than the melting temperature, the reaction proceeds in a solid phase. In particular, if the heating temperature is 200°C or lower, thermal discoloration of the carbonate can be suppressed. The heating temperature is preferably 40°C or higher, more preferably 90°C or higher. If the heating temperature is equal to or higher than the lower limit, the reaction proceeds easily, and polycarbonate productivity is high.

[0067] In step b, it is preferable to start heating at a temperature of about 40 to 110° C., gradually increase the temperature, and finally reach a temperature of 160 to 200° C. By heating the prepolymer in this manner, solid-state polymerization easily proceeds, and a high-molecular-weight polycarbonate with reduced coloration can be obtained. In addition, the productivity of polycarbonate is high.

[0068] The heating time is preferably 1 to 48 hours, more preferably 2 to 36 hours, and particularly preferably 3 to 24 hours. If the heating time is within the above range, the productivity of polycarbonate is high and it is suitable for industrial production.

[0069] Methods for discharging the fluorine-containing alcohol by-produced during solid-state polymerization out of the system include a method of solid-state polymerization under reduced pressure, a method of solid-state polymerization while blowing in an inert gas, a method using these in combination, etc. The method of introducing an inert gas requires the reuse of the inert gas discharged out of the system and is a complicated process, so the method of solid-state polymerization under reduced pressure is more preferred.

[0070] The pressure when solid-state polymerizing the prepolymer under reduced pressure is preferably a high vacuum region of 13 kPa (absolute pressure) (100 torr (absolute pressure)) or less, more preferably 1.3 kPa (absolute pressure) (10 torr (absolute pressure)) or less, and particularly preferably 0.67 kPa to 0.013 kPa (absolute pressure) (5 to 0.1 torr (absolute pressure)). If the pressure is within the above range, the solid-state polymerization proceeds rapidly. The inert gas means a gas inert to solid-state polymerization, and examples thereof include nitrogen, argon, helium, carbon dioxide, lower hydrocarbons, and acetone.

[0071] Examples of solid-state polymerization apparatus include known apparatuses. The type of apparatus may be any type, such as a batch type, a continuous type, or a combination of these. Specific examples include tumbler types, kiln types, paddle dryer types, screw conveyor types, vibration types, fluidized bed types, fixed bed types, and moving bed types. Experimental apparatuses may also include vacuum dryers, such as those used for drying polymers. After polymerization, the resulting polycarbonate may be dissolved in a good solvent and reprecipitated in a poor solvent for polycarbonate.

[0072] In production method (1), even when the ratio (molar ratio) of polyhydric alcohol A to the total of polyhydric alcohol A and ISB exceeds 10 mol % or when the reaction temperature is low (e.g., 200°C or lower), as in solid-state polymerization, the reaction proceeds well and a high-molecular-weight polycarbonate is obtained. Because the structural unit derived from compound 4 at the end of the prepolymer has high affinity with other prepolymers and is susceptible to transesterification, it is believed that the transesterification proceeds even at a relatively low temperature below the melting temperature of the prepolymer (e.g., 200°C or lower).

[0073] [Polycarbonate Production Method (2)] The polycarbonate production method according to the fourth embodiment of the present invention (hereinafter also referred to as production method (2)) involves reacting polyhydric alcohol A with compound 4. Production method (2) is similar to production method (1) except that ISB is not used.

[0074] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the description of the following examples. Examples 1 to 4 and 7 to 15 are working examples, and Examples 5 and 6 are comparative examples.

[0075] [Evaluation Method] (Molecular Weight of Prepolymer and Polycarbonate) The weight average molecular weight (Mw) and number average molecular weight (Mn) of the prepolymer and polycarbonate were measured by GPC using a liquid chromatography system HLC-8320GPC manufactured by TOSO, two Shodex GPC GF-7MHQ columns manufactured by Showa Denko connected in series, and a solvent prepared by dissolving 30 mM lithium bromide and 60 mM phosphoric acid in DMF as the developing solvent (flow rate: 0.3 mL) at 40° C. Calibration curves of elution time and molecular weight were prepared using standard polystyrenes of known molecular weights, and the weight average and number average molecular weights were calculated in polystyrene equivalent from the sample elution curves based on the calibration curves.

[0076] (Actual composition of polycarbonate) The actual composition of the synthesized polycarbonate is １ Using H-nuclear magnetic resonance spectroscopy, the composition ratio was calculated from the integral ratio of protons derived from the corresponding comonomer.

[0077] ( １ H-nuclear magnetic resonance spectrum) １ H-nuclear magnetic resonance spectra were measured in deuterated DMSO solution using a Bruker AVANCE III 400 (400 MHz for 1H). The chemical shifts of various hydrogen nuclei were calculated using tetramethylsilane as the internal standard (0 ppm).

[0078] [Explanation of Abbreviations] ISB: Isosorbide. IMN: Isomannide. DBM: 1,3:4,6-di-O-benzylidene-D-mannitol. ADM: 1,3:4,6-di-O-isopropylidene-D-mannitol. CDM: 1,3:4,6-di-O-cyclohexylidene-D-mannitol. BHFC: Bis(1,1,1,3,3,3-hexafluoroisopropyl)carbonate. DPC: Diphenyl carbonate.

[0079] Example 1 The polycarbonate of Example 1 was produced according to the following procedure. 221.6 mg (1.516 mmol) of ISB and 60.9 mg (0.170 mmol) of DBM were weighed into a heat-resistant glass test tube (15 / 35 common groove) with an outer diameter of 21 mm and a total length of 130 mm. A polytetrafluoroethylene stirrer tip was then placed in the tube. A glass three-way stopcock was attached, and the tube was dried under vacuum for half a day through a diphosphorus pentoxide trap. The atmosphere in the test tube was then purged with nitrogen, and 0.8 mL of dry acetonitrile, 643.8 mg (1.778 mmol) of BHFC, and 16 mg (0.086 mmol) of tri(n-butyl)amine were added under a nitrogen stream to prepare a homogeneous solution. The homogeneous solution was heated at 90°C for 70 hours while stirring with a magnetic stirrer. The product became a white solid and adhered to the bottom of the test tube. Acetonitrile was distilled off under reduced pressure, and 3 mL of dry methylene chloride was added to obtain a homogeneous solution. A portion of the homogeneous solution was taken and １ Analysis by H-nuclear magnetic resonance spectroscopy and GPC revealed that a prepolymer with a weight-average molecular weight of 12,010 and a number-average molecular weight of 5,601 had been produced. The homogeneous solution remaining in the test tube was dried under vacuum, resulting in a white cotton candy-like substance. Next, the atmosphere in the test tube was replaced with nitrogen, and then the test tube was heated in an oil bath using an evaporator while slowly rotating it under vacuum (0.18 kPa) while gradually increasing the temperature (90°C, 110°C for 1 hour each, 130°C, 150°C, 165°C, 180°C for 3 hours each). The reactant in the test tube remained in a solid state throughout. The weight-average molecular weight and number-average molecular weight of the final product are shown in Table 1. The final product was １ In the H-nuclear magnetic resonance spectrum, signals supporting the structure derived from the corresponding polycarbonate were given (7.32-7.52 ppm (DBM6H), 5.74-5.65 ppm (DBM1H), 5.17-4.79 ppm (DBM1H, ISB3H), 4.57-4.40 ppm (ISB1H), 4.40-4.30 ppm (DBM1H), 4.26-4.10 ppm (DBM2H), 4.1-3.93 ppm (ISB1H), 3.93-3.65 ppm (ISB3H)) (all multiplets).

[0080] Examples 2 to 4 Polycarbonates of Examples 2 to 4 were produced in the same manner as in Example 1, except that the amounts (g) of ISB, DBM and tri(n-butyl)amine charged were as shown in Table 1.

[0081] Example 5 The polycarbonate of Example 5 was produced by melt polymerizing ISB, DBM, DPC and tri(n-butyl)amine according to the procedure described in Non-Patent Document 1 (Polymer Chemistry, 2023, 14, 2469).

[0082] Example 6 The polycarbonate of Example 6 was produced in the same manner as in Example 5, except that the amounts (g) of ISB, DBM and tri(n-butyl)amine charged were as shown in Table 1.

[0083] Table 1 shows the charged compositions (mol %) of ISB and DBM, the actual compositions, number average molecular weights (Mn) and weight average molecular weights (Mw) of the resulting polycarbonates in Examples 1 to 6. The charged compositions are the ratios of the charged amounts of ISB and DBM to the total charged amounts of ISB and DBM.

[0084]

[0085] As shown by the above results, polycarbonates with a DBM ratio of 10 mol % or more could be produced in Examples 1 to 4. In addition, the polymerization temperature was low, at 180° C. or less.

[0086] Example 7 The polycarbonate of Example 7 was produced in the same manner as in Example 1, except that the amount (g) of tri(n-butyl)amine charged was as shown in Table 2, half the amount of IMN shown in Table 2 and 2.5 equivalents of BHFC were reacted at 70°C for 90 hours, and then the unreacted BHFC and acetonitrile were distilled off, and the remaining half of the amount of IMN was added.

[0087] Examples 8 to 15 Polycarbonates of Examples 8 to 15 were produced in the same manner as in Example 7, except that the amounts (g) of ISB, IMN, ADM, CDM and tri(n-butyl)amine charged were as shown in Table 2.

[0088] Table 2 shows the charge compositions (mol %) of ISB, IMN, ADM, and CDM, the actual compositions, number average molecular weights (Mn), and weight average molecular weights (Mw) of the resulting polycarbonates in Examples 7 to 15. The charge compositions are the ratios of the respective charge amounts of ISB, IMN, ADM, and CDM to the total charge amount of ISB, IMN, ADM, and CDM.

[0089]

[0090] As shown by the above results, polycarbonates containing a high proportion of polyhydric alcohol A were produced in Examples 7 to 15. In addition, the polymerization temperature was low, at 180° C. or less.

[0091] The polycarbonate of the present invention is useful as optical materials (lenses, optical fibers, films, backlight diffusion plates for LCDs, photoreceptors, etc.), DVDs, CDs, housings for electronic components (cell phones, etc.), windows for transportation equipment, transparent roofing materials, windshields, screens, bulletproof windows, tableware, suitcases, helmets, etc.

Claims

1. A polycarbonate which is a reaction product of at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide), isosorbide, and a compound represented by the following formula 1 (excluding polycarbonates synthesized by the reaction of 1,3:4,6-di-O-benzylidene-D-mannitol, isosorbide, and diphenyl carbonate, in which the proportion of the structure based on 1,3:4,6-di-O-benzylidene-D-mannitol to the total of the structure based on 1,3:4,6-di-O-benzylidene-D-mannitol and the structure based on isosorbide is less than 10 mol %). However, R １ and R ２ each independently represents an organic group.

2. A polycarbonate which is a reaction product of at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide) and a compound represented by the following formula 1: However, R １ and R ２ each independently represents an organic group.

3. The polycarbonate according to claim 1 or 2, wherein the polyhydric alcohol (excluding isosorbide) is a dihydric alcohol.

4. The polycarbonate according to claim 1 or 2, wherein the polyhydric alcohol (excluding isosorbide) is a dihydric alcohol in which (the valence of the sugar alcohol -2) of the hydroxyl groups of a trihydric or higher sugar alcohol are protected with protecting groups.

5. The polycarbonate according to claim 4, wherein the protecting group is at least one selected from the group consisting of a divalent organic group and a monovalent organic group, the divalent organic group is at least one selected from the group consisting of a substituted or unsubstituted alkylene group and a substituted or unsubstituted arylene group, and the monovalent organic group is at least one selected from the group consisting of a substituted or unsubstituted alkyl group and a substituted or unsubstituted aryl group.

6. The polycarbonate according to claim 4, wherein the trihydric or higher sugar alcohol is a hexahydric sugar alcohol or a pentahydric sugar alcohol.

7. The polycarbonate according to claim 4, wherein the trihydric or higher sugar alcohol is mannitol or sorbitol.

8. The polycarbonate according to claim 1 or 2, wherein the polyhydric alcohol (excluding isosorbide) is selected from the group consisting of compounds represented by the following formula 2, the following formula 3 and the following formula 3a. However, R ３ , R ４ , R ５ and R ６ are each independently a hydrogen atom or a substituent, and in formula 3a, R ３ , R ４ , R ５ and R ６ At least three of the groups are substituents.

9. The polycarbonate according to claim 8, wherein the substituent is at least one selected from the group consisting of an alkoxy group, an aryl group, an amino group, a silyl group, a hydroxy group, an allyl group, a carboxy group, an alkyl group, a cycloalkyl group, and a cyano group.

10. The polycarbonate of claim 1 or 2, wherein the polyhydric alcohol (excluding isosorbide) comprises 1,3:4,6-di-O-benzylidene-D-mannitol.

11. The polycarbonate according to claim 1 or 2, having a weight average molecular weight of 20,000 or more.

12. R in the above formula 1 １ and R ２ The polycarbonate according to claim 1 or 2, wherein each of the is independently an organic group containing a fluorine atom.

13. A method for producing a polycarbonate, comprising reacting at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide), isosorbide, and a compound represented by the following formula 4: However, R ｆ１ and R ｆ２ each independently represents an organic group containing a fluorine atom.

14. A method for producing a polycarbonate, comprising reacting at least one polyhydric alcohol derived from a sugar alcohol (excluding isosorbide) with a compound represented by the following formula 4: However, R ｆ１ and R ｆ２ each independently represents an organic group containing a fluorine atom.

15. The method according to claim 13, comprising reacting the polyhydric alcohol (excluding isosorbide), the isosorbide and the compound represented by formula 4 in the presence of a condensation catalyst, heating the resulting prepolymer at a temperature below its melting point, and solid-state polymerizing the prepolymer while discharging the by-produced fluorine-containing alcohol out of the system.

16. The method according to claim 14, comprising reacting the polyhydric alcohol (excluding isosorbide) with the compound represented by formula 4 in the presence of a condensation catalyst, heating the resulting prepolymer at a temperature below its melting point, and discharging the by-produced fluorine-containing alcohol out of the system while solid-state polymerizing the prepolymer.

17. The method according to claim 15 or 16, wherein the temperature during solid-state polymerization of the prepolymer is 200° C. or lower.

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