JP5321582B2 - Method for producing polycarbonate - Google Patents

Description

  The present invention relates to a method for producing polycarbonate.

  Polycarbonate is widely used in many fields as engineering plastics excellent in heat resistance, impact resistance, transparency and the like.

As a method for producing an aromatic polycarbonate, for example, the following methods are known.
(I) A method in which bisphenol A and phosgene are subjected to interfacial polycondensation in the presence of an alkali catalyst (phosgene method).
(Ii) A method of melt polycondensation of bisphenol A and diphenyl carbonate (transesterification method).

  In the method (i), since the reaction proceeds at a low temperature, a colorless and transparent polycarbonate can be obtained. However, toxic phosgene is used; inorganic salts such as sodium chloride produced as a by-product in the reaction must be washed away; since a solvent such as methylene chloride is used, a complicated process such as polymer purification after the reaction, recovery of the solvent, etc. There is a problem that is necessary.

  In the method (ii), since it is not necessary to use a solvent, it is easy to separate the polycarbonate from the reaction system. However, the transesterification reaction between bisphenol A and diphenyl carbonate has a slow reaction rate and requires polycondensation for a long time at a high temperature; the boiling point of phenol separated by the transesterification reaction is high, and a high temperature is required for removal. There is a problem that a side reaction or the like occurs during polycondensation at a high temperature, and the polycarbonate is colored.

The following methods are known as methods for improving the problem of the method (ii).
(Iii) A method in which a prepolymer synthesized by reacting bisphenol-A with diphenyl carbonate or another dialkyl carbonate is reacted with diphenyl carbonate (see Patent Documents 1 and 2).
However, since the reaction form and polycondensation reactivity in the method (iii) are not different from those in the usual method (ii), it is difficult to obtain the same characteristics as the polycarbonate produced by the method (i).

  Aliphatic polycarbonates having a relatively low molecular weight are widely used as main raw materials constituting polyurethane. Therefore, an aliphatic polycarbonate diol having a molecular weight of about 1000 to about 10000 is industrially useful.

The following methods are known as methods for producing aliphatic polycarbonate diols.
(Iv) A method of transesterifying a dialkyl carbonate and an aliphatic diol (see Patent Document 3).
However, also in the method (iv), the reaction rate is slow as in the method (ii), and therefore, a reaction at a high temperature for a long time is required.

Moreover, the following method is known as a manufacturing method of a polycarbonate.
(V) A method of reacting bis (β-fluoroalkyl) carbonate with a dihydric phenol in the presence of a base (see Patent Document 4).
However, basic catalysts such as alkali metals, alkaline earth metals and their hydroxides are used as the catalyst. In general, in the case of polymerization of polycarbonate, there is no step of removing the catalyst after polymerization, so it can be obtained as a product. There was concern about the deterioration of the quality of polycarbonate.

Japanese Patent Laid-Open No. 02-155921 Japanese Patent Application Laid-Open No. 64-1725 JP 2001-270938 A JP-A-55-102626

  The present invention provides a method by which a high-purity polycarbonate having no color can be produced by a simple process without using a toxic compound such as phosgene.

  The polycarbonate production method of the present invention is represented by the compound represented by the following formula (1), the compound represented by the following formula (2), and the following formula (3) in the presence of a halogen salt as a catalyst. This is a method for obtaining a polycarbonate by transesterification of at least one fluorine-containing carbonate selected from the group consisting of the following compounds and a diol.

In the formula, R ¹ is a group represented by CX ¹ Y ¹ R ⁴ , two R ^{1 s} may be the same or different, and R ² is a hydrogen atom or CX ² Y ² R ⁵ Two R ^{2 s} may be the same or different, R ³ is a hydrogen atom or a group represented by CX ³ Y ³ R ⁶ , and two R ³ are the same X ^{1 to} X ³ are each a hydrogen atom, a fluorine atom or R ^f , Y ^{1 to} Y ³ are each a fluorine atom or R ^f , and R ^{4 to} R ⁶ are Each is a fluorine atom, R ^f , OR ^f or an alkyl group having 1 to 6 carbon atoms, and R ^f is a fluoroalkyl group having 1 to 4 carbon atoms (however, it may contain etheric oxygen).

In the formula, R ¹ is a group represented by CX ¹ Y ¹ R ⁴ , R ² is a hydrogen atom or a group represented by CX ² Y ² R ⁵ , and R ³ is a hydrogen atom or CX ³ Y ³ R ⁶ , R ⁷ is a perfluoroalkylene group having 1 to 5 carbon atoms (however, etheric oxygen may be included), and X ^{1 to} X ³ are each represented by It is a hydrogen atom, a fluorine atom or R ^f , Y ^{1 to} Y ³ are each a fluorine atom or R ^f , and R ^{4 to} R ⁶ are each a fluorine atom, R ^f , OR ^f or a carbon number of 1 to 6 It is an alkyl group and ^Rf is a C1-C4 fluoroalkyl group (however, etheric oxygen may be included).

In the formula, R ⁷ is a C 1-5 perfluoroalkylene group (however, etheric oxygen may be included), and two R ⁷ may be the same or different.

  The fluorine-containing carbonate is obtained by a reaction using as a starting material at least one fluorine-containing alcohol selected from the group consisting of a compound represented by the following formula (4) and a compound represented by the following formula (5): Is preferred.

In the formula, R ¹ is a group represented by CX ¹ Y ¹ R ⁴ , R ² is a hydrogen atom or a group represented by CX ² Y ² R ⁵ , and R ³ is a hydrogen atom or CX ³ Y ³ R ⁶ , R ⁷ is a perfluoroalkylene group having 1 to 5 carbon atoms (however, etheric oxygen may be included), and X ^{1 to} X ³ are each represented by It is a hydrogen atom, a fluorine atom or R ^f , Y ^{1 to} Y ³ are each a fluorine atom or R ^f , and R ^{4 to} R ⁶ are each a fluorine atom, R ^f , OR ^f or a carbon number of 1 to 6 It is an alkyl group and ^Rf is a C1-C4 fluoroalkyl group (however, etheric oxygen may be included).

The halogen salt is at least one selected from the group consisting of alkali metal halogen salts, alkaline earth metal halogen salts, ammonium halogen salts, quaternary ammonium halogen salts, and ion exchange resins having a halogen salt structure. It is preferable that
The halogen salt is preferably an alkali metal fluoride.
The halogen salt is preferably quaternary ammonium bromide.
It is preferable that the transesterification reaction is performed in the presence of the catalyst and a cocatalyst, and a solid acid catalyst is used as the cocatalyst.
The solid acid catalyst is preferably at least one selected from the group consisting of a metal oxide having a strong acid point, a heteropolyacid, and a cation exchange resin.
The metal oxide having a strong acid point is cerium oxide (CeO ₂ / Ce ₂ O ₃ ), silica alumina (SiO ₂ · Al ₂ O ₃ ), γ-alumina (Al ₂ O ₃ ), silica magnesia (SiO ₂ · MgO), zirconia _(ZrO 2), silica zirconia _{(SiO 2} · ZrO _2), is preferably at least one selected from the group consisting of ZnO · ZrO _2, and _{Al 2 O 3 · B 2 O} 3.
The fluorine-containing alcohol preferably has 2 to 10 carbon atoms.
R ² in the formula (4) is preferably a group represented by CX ² Y ² R ⁵ .
The fluorine-containing alcohol preferably has a pKa of less than 15.
The pKa of the fluorinated alcohol is preferably less than 10.
Examples of the fluorine-containing alcohol include 1,1,1,3,3,3-hexafluoroisopropanol, perfluoro (t-butyl) alcohol, and 2,2,3,3,4,4,5,5,6, It is preferably at least one selected from the group consisting of 6-decafluorocyclohexanol.

The diol is preferably an aliphatic diol or an aromatic diol.
The aromatic diol is preferably bisphenol A.
The aliphatic diol preferably has 2 to 10 carbon atoms.
The aliphatic diol is at least one selected from the group consisting of 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,3-propanediol and 1,4-butanediol. preferable.

  According to the method for producing a polycarbonate of the present invention, a high-purity polycarbonate having no color can be produced by a simple process without using a toxic compound such as phosgene. Moreover, it becomes possible to obtain a high molecular weight body at a lower temperature by using a specific catalyst, and further, it is possible to suppress the influence of the remaining catalyst on the polycarbonate quality by using a neutral catalyst. From this, it is possible to produce high-quality polycarbonate.

  In the present specification, a compound represented by the formula (1) is referred to as a compound (1). The same applies to compounds represented by other formulas.

<Production method of polycarbonate>
The polycarbonate production method of the present invention is a method for obtaining a polycarbonate by a transesterification reaction between a specific fluorine-containing carbonate and a diol.

(Fluorine carbonate)
The fluorine-containing carbonate is at least one selected from the group consisting of the compound (1), the compound (2) and the compound (3).

In the formula, R ¹ is a group represented by CX ¹ Y ¹ R ⁴ , two R ^{1 s} may be the same or different, and R ² is a hydrogen atom or CX ² Y ² R ⁵ Two R ^{2 s} may be the same or different, R ³ is a hydrogen atom or a group represented by CX ³ Y ³ R ⁶ , and two R ³ are the same X ^{1 to} X ³ are each a hydrogen atom, a fluorine atom or R ^f , Y ^{1 to} Y ³ are each a fluorine atom or R ^f , and R ^{4 to} R ⁶ are Each is a fluorine atom, R ^f , OR ^f or an alkyl group having 1 to 6 carbon atoms, and R ^f is a fluoroalkyl group having 1 to 4 carbon atoms (however, it may contain etheric oxygen).

In the formula, R ¹ is a group represented by CX ¹ Y ¹ R ⁴ , R ² is a hydrogen atom or a group represented by CX ² Y ² R ⁵ , and R ³ is a hydrogen atom or CX ³ Y ³ R ⁶ , R ⁷ is a perfluoroalkylene group having 1 to 5 carbon atoms (however, etheric oxygen may be included), and X ^{1 to} X ³ are each represented by It is a hydrogen atom, a fluorine atom or R ^f , Y ^{1 to} Y ³ are each a fluorine atom or R ^f , and R ^{4 to} R ⁶ are each a fluorine atom, R ^f , OR ^f or a carbon number of 1 to 6 It is an alkyl group and ^Rf is a C1-C4 fluoroalkyl group (however, etheric oxygen may be included).

In the formula, R ⁷ is a C 1-5 perfluoroalkylene group (however, etheric oxygen may be included), and two R ⁷ may be the same or different.

  Many fluorine-containing carbonates are low-viscosity liquids at room temperature, which is advantageous when a polycondensation reaction is performed. In addition, since many have boiling points in the range of 80 to 250 ° C. and high thermal stability, it is easy to obtain high-purity fluorine-containing carbonate by distillation purification, which is advantageous for producing high-quality polycarbonate. is there.

(Method for producing fluorine-containing carbonate)
The fluorine-containing carbonate can be obtained by a reaction using at least one fluorine-containing alcohol selected from the group consisting of the compound (4) and the compound (5) as a starting material.

In the formula, R ¹ is a group represented by CX ¹ Y ¹ R ⁴ , R ² is a hydrogen atom or a group represented by CX ² Y ² R ⁵ , and R ³ is a hydrogen atom or CX ³ Y ³ R ⁶ , R ⁷ is a perfluoroalkylene group having 1 to 5 carbon atoms (however, etheric oxygen may be included), and X ^{1 to} X ³ are each represented by It is a hydrogen atom, a fluorine atom or R ^f , Y ^{1 to} Y ³ are each a fluorine atom or R ^f , and R ^{4 to} R ⁶ are each a fluorine atom, R ^f , OR ^f or a carbon number of 1 to 6 It is an alkyl group and ^Rf is a C1-C4 fluoroalkyl group (however, etheric oxygen may be included).

  As the fluorinated alcohol, those having an acid dissociation degree higher than the acid dissociation degree of the diol are preferable in terms of improving the transesterification reaction rate. Therefore, a compound in which a fluoroalkyl group is directly bonded to the α-position carbon atom of the hydroxyl group (hereinafter also referred to as α-carbon) is preferable. However, an alcohol in which a fluorine atom is directly bonded to the α carbon is not preferable because a decomposition reaction due to a deHF reaction is likely to occur.

As a measure of the degree of acid dissociation, pKa of a fluorinated alcohol is used.
When the diol is an aromatic diol, the pKa of the fluorinated alcohol is preferably less than 10 because the pKa of the phenol is approximately 10.
When the diol is an aliphatic diol, the pKa of the fluorinated alcohol is preferably less than 15 because the pKa of the aliphatic alcohol is about 15 to 16.

As the compound (4), since the acid dissociation degree of the fluorinated alcohol increases as the number of fluoroalkyl groups bonded to the α-carbon increases, R ² is a group represented by CX ² Y ² R ⁵ (that is, Preferably a secondary or tertiary fluorine-containing alcohol), and R ² and R ³ are a group represented by CX ² Y ² R ⁵ and a group represented by CX ³ Y ³ R ⁶ , respectively (ie, More preferably, it is a tertiary fluorine-containing alcohol.

  As for carbon number of fluorine-containing alcohol, 2-10 are preferable. If the fluorine-containing alcohol has 2 or more carbon atoms, it is possible to select a stable fluorine-containing alcohol in which a fluorine atom is not directly bonded to the α-position of the hydroxyl group. If the fluorine-containing alcohol has 10 or less carbon atoms, the boiling point of the fluorine-containing alcohol that is dissociated during the synthesis of the polycarbonate by polymerization becomes a boiling point that can be easily removed under mild conditions. There is no need to synthesize high-quality polycarbonate.

  Specific examples of the fluorinated alcohol include 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoropropanol, 2,2,3,3-tetrafluoropropanol, 1,1,1 , 3,3,3-hexafluoroisopropanol, 2-fluoropropanol, 2,2,3,4,4,4-hexafluorobutanol, 2,2,3,3,4,4,5,5-octafluoro Pentanol, perfluoro (t-butyl) alcohol, 2,2,3,3,4,4,5,5-octafluorocyclopentanol, 2,2,3,3,4,4,5,5, 6,6-decafluorocyclohexanol and the like. From the viewpoint of acid dissociation, 1,1,1,3,3,3-hexafluoroisopropanol, perfluoro (t-butyl) alcohol, 2,2,3 3,4,4,5,5,6,6- decafluorooctanoate cyclohexanol are particularly preferred.

Specific methods for obtaining a fluorinated carbonate by a reaction using a fluorinated alcohol as a starting material include the following methods (a) to (c), and the yield is obtained without using a toxic compound such as phosgene. From the viewpoint of high, the method (c) is preferable.
(A) A method of reacting phosgene with a fluorine-containing alcohol to obtain a fluorine-containing carbonate.
(B) A method of obtaining a fluorinated carbonate by a transesterification reaction between a dialkyl carbonate and a fluorinated alcohol.
(C) A method of obtaining a fluorinated carbonate by reacting the compound (6) with a fluorinated alcohol in the presence of a catalyst.

In the formula, X ^{11 to} X ¹³ are each a hydrogen atom or a halogen atom, at least one of X ^{11 to} X ¹³ is a halogen atom, and X ^{14 to} X ¹⁶ are each a hydrogen atom or a halogen atom. And at least one of X ^{14 to} X ¹⁶ is a halogen atom.
X ^{11 to} X ¹⁶ are preferably all halogen atoms, more preferably fluorine atoms or chlorine atoms, and most preferably all chlorine atoms from the viewpoint that chloroform is obtained as a by-product.

  As the compound (6), hexachloroacetone, pentachloroacetone, tetrachloroacetone, 1,1,2-trichloroacetone, hexafluoroacetone, pentafluoroacetone, 1,1,3,3-tetrafluoroacetone, 1,1 , 2-trifluoroacetone, 1,1,3,3-tetrachloro-1,3-difluoroacetone, 1,1,1-trichloro-3,3,3-trifluoroacetone, 1,3-dichloro-1 1,3,3-tetrafluoroacetone, tetrabromoacetone, pentabromoacetone, hexabromoacetone and the like. Hexachloroacetone is preferred because industrially useful chloroform can be produced in high yield.

  Among the compounds (6), chloroacetones can be easily produced by the method of chlorinating acetone described in JP-B-60-52741 and JP-B-61-16255. Moreover, a partially fluorinated compound can be easily produced by the method of fluorinating chloroacetones with hydrogen fluoride described in US Pat. No. 6,235,950.

  The ratio between the number of moles of the first charge of the fluorinated alcohol and the number of moles of the first charge of the compound (6) (fluorinated alcohol / compound (6)) is from the point of improving the yield of the fluorinated carbonate, More than 1, preferably 1.5 or more, more preferably 2 or more.

Examples of the catalyst used in the method (c) include catalysts used in the polycondensation reaction described later.
The amount of the catalyst is variously selected depending on the catalyst, but is preferably 0.01 to 30% by mass with respect to the substrate, and more preferably 0.1 to 10% by mass in consideration of the reaction activity and the catalyst removal step after the reaction. .

In the method (c), a solvent may be used for the purpose of promoting the reaction. However, considering the volumetric efficiency of the reactor and the loss of the target product during the solvent separation step, it is preferable to carry out the reaction without solvent if possible.
The reaction temperature in the method (c) is preferably 40 to 200 ° C.
The reaction pressure in the method (c) is usually atmospheric pressure.

(Diol)
Examples of the diol include aliphatic diols and aromatic diols.

  Aliphatic diols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 3-chloro-1,2-propanediol, 2-chloro-1,3-propanediol, cyclohexanediol, 1,2-propylene glycol , Dipropylene glycol, tripropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,4-butenediol, 2-methyl-2, 4-pentanediol (hexylene glycol), 3-methyl-1,5-pentanediol, 1,5-pentanediol, 1,6-hexanediol, fluorine-containing diol (3,3,3-trifluoro-1, 2-propanediol, etc.).

  As the aliphatic diol, an aliphatic diol having 2 to 10 carbon atoms is more preferable from the viewpoint of the usefulness of an aliphatic polycarbonate diol used as a raw material for polyurethane and the like, and 3-methyl-1,5-pentanediol, 1, 6-hexanediol, 1,3-propanediol and 1,4-butanediol are particularly preferred.

  Aromatic diols include resorcinol, catechol, hydroquinone, 2,2- (bis (4-hydroxyphenyl) propane [alias: bisphenol A], 2,2-bis (4-hydroxyphenyl) hexafluoropropane [alias: bisphenol. AF], bis (4-hydroxyphenyl) methane, 4,4′-dihydroxybiphenyl, bis (4-hydroxybiphenyl) ether, dihydroxynaphthalene, phloroglicinol, and phenol condensates. Bisphenol A is preferred from the standpoint of ease and usefulness of polycarbonate.

(Transesterification reaction)
As a specific method for obtaining a polycarbonate by transesterifying a fluorinated carbonate and a diol, the following method (A) or (B) can be mentioned, and since it can be produced by a simple process, (A) This method is preferred.
(A) A method of melt polycondensation of a fluorine-containing carbonate and a diol.
(B) A method of subjecting a fluorine-containing carbonate and a diol to solution polycondensation.

  The reaction temperature in the method (A) is preferably not less than the melting point of the diol in the early stage of the reaction, and preferably not less than the melting point of the polycarbonate in the later stage of the reaction. In addition, the reaction temperature in the method (A) is preferably 300 ° C. or lower from the viewpoint of suppressing the coloring of the polycarbonate.

The ratio between the number of moles of the initial charge of the fluorinated carbonate and the number of moles of the first charge of the diol (fluorinated carbonate / diol) may be appropriately selected according to the target molecular weight of the polycarbonate.
The fluorine-containing carbonate / diol ratio (molar ratio) in the case of obtaining the aliphatic polycarbonate diol is preferably 0.80 to 0.97 from the viewpoint of obtaining an aliphatic polycarbonate diol having a molecular weight of about 1000 to about 10,000.

(catalyst)
The polycondensation reaction is carried out in the presence of a halogen salt as a catalyst.
In the present specification, the halogen salt refers to a salt of a metal cation or an organic cation and a halogen ion.
The halogen salt is at least one selected from the group consisting of alkali metal halogen salts, alkaline earth metal halogen salts, ammonium halogen salts, quaternary ammonium halogen salts, and ion exchange resins having a halogen salt structure. Is preferred.

Examples of the alkali metal halogen salt include LiF, LiCl, LiBr, NaF, NaCl, NaBr, KF, KCl, KBr, RbF, RbCl, RbBr, CsF, CsCl, CsBr, and the like.
Examples of the alkaline earth metal halide salt include BeF ₂ , BeCl ₂ , BeBr ₂ , CaF ₂ , CaCl ₂ , CaBr ₂ , SrF ₂ , SrCl ₂ , and SrBr ₂ .
Examples of the halogen salt of ammonium include NH ₄ F, NH ₄ Cl, NH ₄ Br, and the like.

  Examples of the quaternary ammonium halogen salt include the following compound (7).

However, R < ¹¹ > -R < ¹⁴ > represents a hydrocarbon group, respectively, and Y < ^- > represents a halogen ion.

Examples of R ^{11 to} R ¹⁴ include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, an alkylaryl group, an aralkyl group, and the like, and an alkyl group, an aryl group, or an aralkyl group is preferable.
The total number of carbon atoms of R ^{11 to} R ¹⁴ is preferably 4 to 100 per molecule of R ¹¹ R ¹² R ¹³ R ¹⁴ N ⁺ .
R ^{11 to} R ¹⁴ may be the same group or different groups.
R ^{11 to} R ¹⁴ may be substituted with a functional group that is inert under the reaction conditions. Examples of the inert functional group include a halogen atom, an ester group, a nitrile group, an acyl group, a carboxyl group, and an alkoxyl group, depending on the reaction conditions.
R ^{11 to} R ¹⁴ may be connected to each other to form a heterocyclic ring (such as a nitrogen-containing heterocyclic ring).
R ^{11 to} R ¹⁴ may be a part of the polymer compound.

R ¹¹ R ¹² R ¹³ R ¹⁴ N ⁺ includes tetramethylammonium ion, tetraethylammonium ion, tetra-n-propylammonium ion, tetra-n-butylammonium ion, tri-n-octylmethylammonium ion, cetyltrimethylammonium ion Ion, benzyltrimethylammonium ion, benzyltriethylammonium ion, cetylbenzyldimethylammonium ion, cetylpyridinium ion, n-dodecylpyridinium ion, phenyltrimethylammonium ion, phenyltriethylammonium ion, N-benzylpicolinium ion, pentamethonium ion, hexa Examples include metonium ions.

Examples of Y ⁻ include chlorine ion, fluorine ion, bromine ion and iodine ion, and chlorine ion, fluorine ion and bromine ion are preferable.

The compound (7) is preferably a combination of the following R ¹¹ R ¹² R ¹³ R ¹⁴ N ⁺ and the following Y ⁻ from the viewpoint of versatility and reactivity of the compound (7).
R ¹¹ R ¹² R ¹³ R ¹⁴ N ⁺ : Tetramethylammonium ion, tetraethylammonium ion, tetra-n-propylammonium ion, tetra-n-butylammonium ion or tri-n-octylmethylammonium ion.
Y ⁻ : Fluorine ion, chlorine ion or bromine ion.

  Examples of the ion exchange resin having a halogen salt structure include an anion type ion exchange resin having a halogen ion as an anion. Commercially available products include Diaion (registered trademark) series (Mitsubishi Chemical Corporation), Amberlite (registered trademark) series (Rohm and Haas), Amberlist (registered trademark) series (Rohm and Haas) Manufactured) and the like.

The halogen salt is preferably an alkali metal fluoride (NaF, KF, etc.) or a quaternary ammonium bromide in terms of reactivity and utilization on an industrial scale.
The halogen salt may be supported on a metal oxide or a composite oxide. Examples of the compound include soda lime.

(Cocatalyst)
In the method for producing a polycarbonate compound of the present invention, the transesterification reaction is preferably performed in the presence of a catalyst and a cocatalyst. By using a cocatalyst, the catalytic activity can be improved.
A solid acid catalyst is used as the promoter.
The solid acid catalyst is preferably at least one selected from the group consisting of a metal oxide having a strong acid point, a heteropolyacid, and a cation exchange resin.
Examples of the metal oxide having a strong acid point include SiO ₂ · Al ₂ O ₃ , SiO ₂ · MgO, SiO ₂ · ZrO ₂ , Al ₂ O ₃ · B ₂ O ₃ , Al ₂ O ₃ , ZrO ₂ , ZnO · ZrO. ₂ , CeO ₂ , Ce ₂ O ₃ , various zeolites and the like. From the viewpoint of acid strength and reaction selectivity, cerium oxide (CeO ₂ / Ce ₂ O ₃ ), silica alumina (SiO ₂ · Al ₂ O ₃ ) , Γ-alumina (Al ₂ O ₃ ), silica magnesia (SiO ₂ · MgO), zirconia (ZrO ₂ ), silica zirconia (SiO ₂ · ZrO ₂ ), ZnO · ZrO ₂ , and Al ₂ O ₃ · B ₂ O _At least one selected from the group consisting of ₃ is preferred.

  In the method for producing a polycarbonate of the present invention described above, since a specific fluorinated carbonate derived from a fluorinated alcohol having a relatively high acid dissociation degree and a diol are transesterified, toxicity such as phosgene Without using this compound, a high-purity polycarbonate without coloration can be produced by a simple process.

  That is, the fluorine-containing carbonate compound in the present invention has a high degree of dissociation of the ester moiety due to the effect of electron withdrawing by fluorine atoms, and is easily transesterified with an aromatic diol or an aliphatic diol. This is an excellent production method capable of solving problems such as coloring caused by reacting at a high temperature for a long time, which was a problem of a polycarbonate production method by an exchange method.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these Examples.

(Gas chromatography (GC) analysis)
GC analysis was performed using an Agilent 6890 series.

(Infrared absorption spectrum (IR) analysis)
Using an Avatar / Nicolet FT-IR360 manufactured by Thermo Fisher Scientific, the appearance of carbonate bonds and the disappearance of absorption derived from hydroxyl groups were confirmed by a total reflection method.

(Gel permeation chromatography (GPC) analysis)
Using HLC-8220GPC manufactured by Tosoh Corporation, analysis was performed under the following conditions, and the molecular weight was determined in terms of standard polystyrene.
Column: TSK GUARDCOLUMN SUPERHZ series column (HZ-L guard column, 4000, 3000, 2500 and 2000),
Mobile phase: tetrahydrofuran,
Flow rate: 0.35 mL / min,
Detection method: RI detection,
Column temperature: 40 ° C.

(NMR analysis)
The sample was dissolved in deuterated chloroform (CDCl ₃ ) solvent, and proton nuclei were measured using JMTC-300 / 54 / SS manufactured by JEOL Ltd. and tetramethylsilane as a standard sample at a room temperature of 126 times. It was.

[Production example]
Production of bis (2,2,3,3-tetrafluoropropyl) carbonate (compound (11)):
A 500 mL glass reactor equipped with a stirrer, a reflux condenser at 20 ° C. and a distillation line was charged with 201 g (0.76 mol) of hexachloroacetone and 358 g (2 of 2,2,3,3-tetrafluoropropanol). .71 mol) and 10 g of KF were charged, the temperature was gradually raised while stirring, and the reaction was carried out at an internal temperature of 100 ° C. for 20 hours. After completion of the reaction, 560 g of the reaction crude liquid present in the reactor was recovered. As a result of GC analysis of the recovered liquid, it was confirmed that the compound (11) was produced.

[Example 1]
In a 200 mL glass reactor equipped with a stirrer, a mantle heater, a rectifying column, and a decompression device, 68.5 g (0.30 mol) of compound (11) and 93.1 g of bisphenol A (compound (12)) were added. (0.32 mol) and 174 mg (3.0 mmol) of KF were charged, and after replacing with nitrogen, the mixture was melted by heating.

  After stirring for 30 minutes, the pressure was gradually reduced while raising the temperature to 180 ° C., and the reaction was carried out at 400 mmHg for 1 hour while distilling off the 2,2,3,3-tetrafluoropropanol formed. Subsequently, after heating up to 200 degreeC, it pressure-reduced gradually and was made to react with 100 mmHg for 30 minutes. Further, the reaction was continued by repeatedly raising the temperature and reducing the pressure to 250 ° C./1 mmHg or less in the same manner as described above, and finally, the reaction was performed at 250 ° C./1 mmHg or less for 2 hours.

The results obtained polymer IR analysis, absorption by carbonyl group at the position of 1746cm ^-1, absorption due to an ether bond was observed at 1228cm ^-1, to have a carbonate bond was confirmed. Moreover, the absorption derived from a hydroxyl group was hardly recognized by the position of 3650-3200cm < ^-1 >.
Therefore, the polymer was recognized as a polycarbonate represented by the following formula (13).

  The weight average molecular weight (Mw) by GPC analysis of the polycarbonate is 905, the number average molecular weight (Mn) is 530, the dispersity (Mw / Mn) is 1.79, and n = 3 is the center. = 2-10 mixture of molecules. The polycarbonate was not colored and was found to be of high purity.

[Example 2]
A polymer was obtained in the same manner as in Example 1 except that 455 mg (3.0 mmol) of CsF was used instead of KF as a catalyst. The polymer was recognized as a polycarbonate represented by the formula (13) by IR analysis.

  The weight average molecular weight (Mw) of the polycarbonate by GPC analysis is 1047, the number average molecular weight (Mn) is 667, the dispersity (Mw / Mn) is 1.58, and n = 4 is the center. = 2-10 mixture of molecules. The polycarbonate was not colored and was found to be of high purity.

[Example 3]
A polymer was obtained in the same manner as in Example 1 except that 4.6 mg (0.03 mmol) of CsF was used instead of KF as a catalyst. The polymer was recognized as a polycarbonate represented by the formula (13) by IR analysis.

  The weight average molecular weight (Mw) by GPC analysis of the polycarbonate is 820, the number average molecular weight (Mn) is 500, the dispersity (Mw / Mn) is 1.64, and n is centered on n = 3. = 2-7 mixture of molecules. The polycarbonate was not colored and was found to be of high purity.

[Example 4]
50.4 g (0.15 mol) of 2,2-bis (4-hydroxyphenyl) hexafluoropropane (compound (14)) instead of bisphenol A as a diol component, and 227 mg (1 of CsF instead of KF as a catalyst) 0.5 mmol) was carried out in the same manner as in Example 1.

The results obtained polymer IR analysis, absorption by carbonyl group at the position of 1740 cm ^-1, absorption due to an ether bond was observed at 1210cm ^-1, to have a carbonate bond was confirmed. Moreover, the absorption derived from a hydroxyl group was hardly recognized by the position of 3650-3200cm < ^-1 >.
Therefore, the polymer was recognized as a polycarbonate represented by the following formula (15).

  The mass average molecular weight (Mw) of the polycarbonate by GPC analysis is 541, the number average molecular weight (Mn) is 422, the dispersity (Mw / Mn) is 1.28, and n is centered on n = 3. = 2-4 mixture of molecules. The polycarbonate was not colored and was found to be of high purity.

[Example 5]
To a 30 mL glass reactor equipped with a stirrer, an oil bath, a cooling trap and a decompressor, 4.55 g (38.5 mmol) of 1,6-hexanediol (HO— (CH ₂ ) ₆ —OH) was added. The oil bath was charged and kept at 100 ° C., and dehydration was performed at a reduced pressure of 5 mmHg for 2 hours.

  After substituting with nitrogen, it was cooled, and 10.5 g (35 mmol) of compound (11) and 150 mg (0.9 mmol) of CsF were added to the reactor in a nitrogen glove box, and then the temperature was raised to 120 ° C. The pressure was gradually reduced while the reaction was carried out at 400 mmHg for 1 hour while distilling off the 2,2,3,3-tetrafluoropropanol formed. Subsequently, after raising the temperature to 150 ° C., the pressure was gradually reduced and the reaction was carried out at 11 mmHg for 5 hours.

When the obtained polymer was subjected to NMR analysis, 4.0 to 4.1 ppm of adjacent methylene peaks derived from polycarbonate were confirmed.
Therefore, the polymer was recognized as a polycarbonate represented by the following formula (16).

  The polycarbonate had a mass average molecular weight (Mw) of 5773, a number average molecular weight (Mn) of 1933, and a dispersity (Mw / Mn) of 2.99. The polycarbonate was not colored and was found to be of high purity.

[Example 6]
A polymer was obtained in the same manner as in Example 5 except that 4.55 g (38.5 mmol) of 3-methyl-1,5-pentanediol was used instead of 1,6-hexanediol. When the obtained polymer was subjected to NMR analysis, 4.0 to 4.1 ppm of adjacent methylene peaks derived from polycarbonate were confirmed.
Therefore, the polymer was recognized as a polycarbonate represented by the following formula (17).

  The polycarbonate had a mass average molecular weight (Mw) of 3048, a number average molecular weight (Mn) of 1521, and a dispersity (Mw / Mn) of 2.01. The polycarbonate was not colored and was found to be of high purity.

[Example 7]
A polymer was obtained in the same manner as in Example 5 except that 2.93 g (38.5 mmol) of 1,3-propanediol was used instead of 1,6-hexanediol. When the obtained polymer was subjected to NMR analysis, 4.0 to 4.1 ppm of adjacent methylene peaks derived from polycarbonate were confirmed.
Therefore, the polymer was recognized as a polycarbonate represented by the following formula (18).

  The polycarbonate had a mass average molecular weight (Mw) of 1268, a number average molecular weight (Mn) of 735, and a dispersity (Mw / Mn) of 1.73. The polycarbonate was not colored and was found to be of high purity.

[Example 8]
A polymer was obtained in the same manner as in Example 5 except that 3.47 g (38.5 mmol) of 1,4-butanediol was used instead of 1,6-hexanediol. When the obtained polymer was subjected to NMR analysis, 4.0 to 4.1 ppm of adjacent methylene peaks derived from polycarbonate were confirmed.
Therefore, this polymer was recognized as a polycarbonate represented by the following formula (19).

  The polycarbonate had a mass average molecular weight (Mw) of 2060, a number average molecular weight (Mn) of 1250, and a dispersity (Mw / Mn) of 1.65. The polycarbonate was not colored and was found to be of high purity.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2008-090433 filed on Mar. 31, 2008, the contents of which are incorporated herein by reference.

  The aromatic polycarbonate obtained by the production method of the present invention is useful as engineering plastics. The aliphatic polycarbonate obtained by the production method of the present invention is useful as a raw material for polyurethane, polyol, polyester and the like.

Claims (17)

In the presence of a halogen salt as a catalyst, at least selected from the group consisting of a compound represented by the following formula (1), a compound represented by the following formula (2), and a compound represented by the following formula (3) A method for producing a polycarbonate, characterized in that a polycarbonate is obtained by a transesterification reaction between one kind of fluorine-containing carbonate and a diol.

In the formula, R ¹ is a group represented by CX ¹ Y ¹ R ⁴ , and two R ¹ may be the same or different,
R ² is a hydrogen atom or a group represented by CX ² Y ² R ⁵ , and two R ² may be the same or different,
R ³ is a hydrogen atom or a group represented by CX ³ Y ³ R ⁶ , and two R ³ may be the same or different,
X ^{1 to} X ³ are each a hydrogen atom, a fluorine atom or R ^f ,
Y ^{1 to} Y ³ are each a fluorine atom or R ^f ,
R ^{4 to} R ⁶ are each a fluorine atom, R ^f , OR ^f or an alkyl group having 1 to 6 carbon atoms,
R ^f is a fluoroalkyl group having 1 to 4 carbon atoms (however, it may contain etheric oxygen);

In the formula, R ¹ is a group represented by CX ¹ Y ¹ R ⁴ ;
R ² is a hydrogen atom or a group represented by CX ² Y ² R ⁵ ,
R ³ is a hydrogen atom or a group represented by CX ³ Y ³ R ⁶ ,
R ⁷ is a C 1-5 perfluoroalkylene group (however, it may contain etheric oxygen);
X ^{1 to} X ³ are each a hydrogen atom, a fluorine atom or R ^f ,
Y ^{1 to} Y ³ are each a fluorine atom or R ^f ,
R ^{4 to} R ⁶ are each a fluorine atom, R ^f , OR ^f or an alkyl group having 1 to 6 carbon atoms,
R ^f is a fluoroalkyl group having 1 to 4 carbon atoms (however, it may contain etheric oxygen);

In the formula, R ⁷ is a C 1-5 perfluoroalkylene group (however, etheric oxygen may be included), and two R ⁷ may be the same or different.   The halogen salt is at least one selected from the group consisting of alkali metal halogen salts, alkaline earth metal halogen salts, ammonium halogen salts, quaternary ammonium halogen salts, and ion exchange resins having a halogen salt structure. The method for producing a polycarbonate according to claim 1, wherein   The method for producing a polycarbonate according to claim 1, wherein the halogen salt is an alkali metal fluoride.   The method for producing a polycarbonate according to claim 1 or 2, wherein the halogen salt is a quaternary ammonium bromide.   The method for producing a polycarbonate according to any one of claims 1 to 4, wherein the transesterification reaction is performed in the presence of the catalyst and a cocatalyst, and the cocatalyst is a solid acid catalyst.   The method for producing a polycarbonate according to claim 5, wherein the solid acid catalyst is at least one selected from the group consisting of a metal oxide having a strong acid point, a heteropolyacid, and a cation exchange resin. The metal oxide having a strong acid point is cerium oxide (CeO ₂ / Ce ₂ O ₃ ), silica alumina (SiO ₂ · Al ₂ O ₃ ), γ-alumina (Al ₂ O ₃ ), silica magnesia (SiO ₂ · MgO), zirconia _(ZrO 2), silica zirconia _{(SiO 2} · ZrO _2), is at least one selected from the group consisting of ZnO · ZrO _2, and _{Al 2 O 3 · B 2 O} 3, in claim 6 The manufacturing method of the polycarbonate of description. The fluorine-containing carbonate is obtained by a reaction using as a starting material at least one fluorine-containing alcohol selected from the group consisting of a compound represented by the following formula (4) and a compound represented by the following formula (5): The manufacturing method of the polycarbonate in any one of Claims 1-7.

^{However, R 1} is a group represented by CX ¹ Y ^{1 R 4,}
R ² is a hydrogen atom or a group represented by CX ² Y ² R ⁵ ,
R ³ is a hydrogen atom or a group represented by CX ³ Y ³ R ⁶ ,
R ⁷ is a C 1-5 perfluoroalkylene group (however, it may contain etheric oxygen);
X ^{1 to} X ³ are each a hydrogen atom, a fluorine atom or R ^f ,
Y ^{1 to} Y ³ are each a fluorine atom or R ^f ,
R ^{4 to} R ⁶ are each a fluorine atom, R ^f , OR ^f or an alkyl group having 1 to 6 carbon atoms,
^Rf is a C1-C4 fluoroalkyl group (however, it may contain etheric oxygen).   The method for producing a polycarbonate according to claim 8, wherein the fluorine-containing alcohol has 2 to 10 carbon atoms. The method for producing a polycarbonate according to claim 8 or 9, wherein R ² in the formula (4) is a group represented by CX ² Y ² R ⁵ .   The manufacturing method of the polycarbonate in any one of Claims 8-10 whose pKa of the said fluorine-containing alcohol is less than 15.   The method for producing a polycarbonate according to any one of claims 8 to 11, wherein the fluorine-containing alcohol has a pKa of less than 10.   The fluorine-containing alcohol is 1,1,1,3,3,3-hexafluoroisopropanol, perfluoro (t-butyl) alcohol, and 2,2,3,3,4,4,5,5,6, The method for producing a polycarbonate according to any one of claims 8 to 12, which is at least one selected from the group consisting of 6-decafluorocyclohexanol.   The method for producing a polycarbonate according to claim 1, wherein the diol is an aliphatic diol or an aromatic diol.   The method for producing a polycarbonate according to claim 1, wherein the diol is bisphenol A.   The manufacturing method of the polycarbonate in any one of Claims 1-14 whose said diol is a C2-C10 aliphatic diol.   The diol is at least one selected from the group consisting of 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,3-propanediol, and 1,4-butanediol. The manufacturing method of the polycarbonate in any one of -14 and 16.