JPS63205318A - Production of aromatic polycarbonate - Google Patents

Abstract

PURPOSE:To obtain a high-quality, high-MW aromatic polycarbonate industrially in good efficiency, by self-condensing a bisalkyl carbonate of an aromatic dihydroxy compound in the presence of a specified catalyst in the absence of any reaction inhibiting substance. CONSTITUTION:A bisalkyl carbonate of an aromatic dihydroxy compound of the formula (wherein R<1-2> are each a 1- 6 C alkyl or a cycloalkyl, and Ar is a bivalent aromatic group) is self-condensed at 20-350 deg.C for several min to several tens of hr in the presence of at least one catalyst selected from among the Group IIB, IIIBS, IVA and IVB metallic elements of the periodic table and their compounds (e.g., dibutyltin oxide) in the substantial absence (e.g., at most 5mol%, based on the aromatic skeleton units of the aromatic polycarbonate) of an aromatic dihydroxy compound as a reaction inhibiting substance while, if required, the formed dialkyl carbonate is being removed from the reaction system. In this way, a high-MW aromatic polycarbonate of a weight-average MW of 6,000-100,000 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to improvements in the production process of aromatic polycarbonates. More specifically, the present invention relates to a method for industrially and efficiently producing a high molecular weight aromatic polycarbonate by a self-polycondensation reaction of a bisalkyl carbonate of an aromatic dihydroxy compound.

Conventional technology In recent years, aromatic polycarbonates have been developed with high heat resistance, impact resistance,
It is widely used in many fields as an engineering plastic with excellent transparency. Various studies have been conducted on the production method of aromatic polycarbonate, and among them, aromatic dihydroxy compounds such as 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A) and phosgene have been investigated. The interfacial polycondensation method has been industrialized.

However, in this interfacial polycondensation method using phosgene, (1) toxic phosgene must be used, (2) equipment is corroded by chlorine-containing compounds such as hydrogen chloride and sodium chloride, which are produced as by-products, and (3) ) It is difficult to separate impurities that adversely affect the physical properties of the polymer, such as sodium chloride, mixed into the resin; (4) A large amount of solvent is used, and its separation and recovery are expensive. with many problems.

Therefore, in order to solve such problems, methods for producing aromatic polycarbonates that do not use phosgene have been developed, for example, a method using a transesterification reaction between an aliphatic dialkyl carbonate and an aromatic dihydroxy compound, and -233.4 Publication, 60-16944
4, 60-169445), a method by transesterification of a dialkyl carbonate and a fatty acid ester of an aromatic dihydroxy compound (JP-A-59-2
10938) etc. have been proposed. However, although these methods overcome the problems mentioned above in the phosgene method, the former method has drawbacks such as slow reaction and difficulty in obtaining high molecular weight products, while the latter method In this method, unstable and toxic substances such as ketene are produced during the production of raw materials, and the steps are complicated, so it cannot be said to be a satisfactory method as an industrial process.

Furthermore, a direct method for producing polycarbonate by reacting an aromatic dihydroxy compound with carbon oxide and oxygen in the presence of a noble metal catalyst such as palladium has also been proposed (
JP-A-53-687'44, JP-A-53-68745
No. 53-68746, No. 53-687
Publication No. 47). However, this method also has problems such as the use of expensive precious metals and the inability to increase the degree of polymerization of polycarbonate, and has not yet reached the level of an industrial process.

In addition, the so-called transesterification method, which is a conventionally known method and is a temporarily industrialized process, uses diphenyl carbonate obtained from phenol and phosgene as a raw material and reacts it with bisphenol A. Problems such as toxicity and corrosion of equipment due to the use of phosgene have not been resolved.

On the other hand, there have been some reports on a method for producing polycarbonate by self-polycondensation of bisphenyl carbonate or bisalkyl carbonate of bisphenol A obtained from the reaction of phenyl chloroformate or alkyl chloroformate with a dialkali metal salt of bisphenol A. (Japanese Patent Publication No. 37-3296, U.S. Patent No. 2,946,766
No. Specification). However, in these methods, examples of the self-polycondensation reaction of only bisalkyl carbonate of bisphenol A have not been studied. There is no mention of an example in which a small amount of bisalkyl carbonate of bisphenol A was added during the production of . That is, little is known specifically about the self-polycondensation reaction characteristics of bisalkyl carbonate esters of bisphenol A, and rather, they were thought to be the same as those of bisaryl carbonate esters of bisphenol A.

In addition, problems remain with catalysts used in the self-polycondensation reaction of biscarbonate esters containing bisphenyl carbonate of bisphenol A as a main component.

That is, it has been proposed to use a manganese salt of an organic or inorganic acid as a catalyst (Japanese Patent Publication No. 37-329).
6), the degree of polymerization of the product is low and it cannot be said to be a practical catalyst, and it has also been proposed to use a basic transesterification catalyst such as sodium salt of bisphenol A ( (U.S. Pat. No. 2,946,766) Polymers produced in the presence of such catalysts have the disadvantage of being easily colored.

Problems to be Solved by the Invention The present invention overcomes the drawbacks of the conventional polycarbonate production method and provides an excellent method for industrially and efficiently producing high-quality high-molecular-weight polycarbonate without using phosgene. This was done for the purpose of providing a method.

Means for Solving the Problems The present inventors have conducted intensive research on a method for industrially and efficiently producing high molecular weight polycarbonate without using phosgene. We have discovered that the above object can be achieved by carrying out the reaction in the presence of a catalyst and in the absence of certain compounds that inhibit the reaction, and based on this knowledge, we have completed the present invention.

That is, the present invention is based on the general formula % () (R1 and R2 in the formula are each a lower alkyl group or a cycloalkyl group having 1 to 6 carbon atoms, and they may be the same or each other. When manufacturing an aromatic polycarbonate by self-polycondensing bisalkyl carbonate of an aromatic dihydroxy compound represented by (Ar is a divalent aromatic group), Ar is a divalent aromatic group. In the presence of at least one catalyst selected from metal elements belonging to the JIB, [lB, IVA and ■B groups and their compounds, and the aromatic hydroxyl compound, that is, the compound having an aromatic hydroxyl group, is substantially The present invention provides a method for producing an aromatic polycarbonate, which is characterized in that the reaction is carried out under conditions in which the aromatic polycarbonate is not present.

The present invention will be explained in detail below.

In the method of the present invention, the self-polycondensation reaction of the bisalkyl carbonate of an aromatic dihydroxy compound is performed by polycondensing the bisalkyl carbonate of the aromatic dihydroxy compound represented by the above general formula without eliminating the dialkyl carbonate. The reaction is ideally expressed by the reaction formula shown below.

n・R10co-Ar-OCOR2->j11 --- (n) (R1, R2 and Ar in the formula have the same meanings as above,
(n is an integer) If such a self-polycondensation reaction is performed in the same manner as the conventional self-polycondensation method using bisaryl carbonate of an aromatic dihydroxy compound, it is difficult to obtain a high molecular weight polycarbonate. This was discovered through research by the present inventors. That is, when self-polycondensation is carried out using a bisalkyl carbonate of an aromatic dihydroxy compound obtained by the reaction of an aromatic dihydroxy compound and a chloroformic acid alkyl ester or a dialkyl carbonate as a raw material in a conventional manner, It was difficult to obtain a polycarbonate with a high degree of polymerization compared to the case where the obtained aromatic dihydroxy compound was subjected to self-polycondensation using a bisaryl carbonate transesterification catalyst.

This was completely different from the prediction that the bisalkyl carbonate of the aromatic dihydroxy compound would show the same reactivity as the bisaryl carbonate of the compound.

Therefore, in order to obtain a high molecular weight aromatic polycarbonate from bisalkyl carbonate esters of aromatic dihydroxy compounds, the present inventors conducted a detailed study on the self-polycondensation reaction of aromatic dihydroxy compounds. We have discovered a completely new fact that is an inhibitor of this polycondensation reaction. The fact that this aromatic hydroxyl compound acts as an inhibitor of the self-polycondensation reaction of bis-alkyl carbonates is completely unexpected based on the previous self-polycondensation reactions of bis-aryl carbonates. It was a surprising thing.

That is, bisaryl carbonate of an aromatic dihydroxy compound, such as bisphenyl carbonate of bisphenol A, is reacted with bisphenol A, an aromatic hydroxyl compound, to give a polycarbonate, as disclosed in the aforementioned U.S. Pat. No. 2,946,966. It is clear from the specification. This reaction can be expressed by the reaction formula shown below.

H3 00H30 H3 In the case of bisaryl carbonate esters of aromatic dihydroxy compounds, aromatic hydroxy compounds such as bisphenol A do not have any adverse effect on this polycondensation reaction, or conversely, they are used as monomers. It is known to work effectively.

By the way, bisaryl carbonate or bisalkyl carbonate of aromatic dihydroxy compound is usually
Produced from an aromatic dihydroxy compound as a raw material by a reaction involving dehydrochlorination with an aryl chloroformate or alkyl chloroformate, or a reaction involving dephenolization or dealcoholization with a diaryl carbonate or dialkyl carbonate. There is. Among the bisaryl carbonates or bisalkyl carbonates of aromatic dihydroxy compounds produced by such methods, there are usually a small amount of aromatic dihydroxy compounds and reaction intermediates such as almonohydroxy monocarbonate, etc. Aromatic hydroxyl compounds are mixed. In the case of a self-polycondensation reaction in which bisaryl carbonate of an aromatic dihydroxy compound is the main component, such an aromatic hydroxyl compound acts as a monomer, as described above.

However, in the case of a self-polycondensation reaction in which bisalkyl carbonate of an aromatic dihydroxy compound is the main component, such an aromatic hydroxyl compound acts as an inhibitor of the polycondensation reaction and cannot suppress the increase in molecular weight. It was revealed. The reason for this is not clear, but in order to obtain a high molecular weight aromatic polycarbonate using bisalkyl carbonate esters of aromatic dihydroxy compounds, it is necessary to avoid the presence of such aromatic hydroxyl compounds during the reaction. It is necessary.

To this end, it is necessary to use raw materials for polycondensation in which the amount of aromatic hydroxyl compounds present is as small as possible;
It is important to prevent the formation of aromatic hydroxyl compounds as much as possible during the polycondensation reaction. That is,
Compounds with active hydrogen, such as water and alcohols, may generate all aromatic hydroxyl compounds under the reaction conditions, so it is necessary to use raw materials for polycondensation in which the amount of such compounds is as small as possible. It is also important to prevent such active hydrogen-containing compounds from leaking into the reactor during the reaction.

For example, if water is present in the reaction system, it is thought that under the reaction conditions, the alkyl carbonate group of the polymerization raw material will be hydrolyzed and stripped to produce a low-molecular aromatic hydroxyl compound. It is believed that certain alkyl carbonate groups are also hydrolyzed. In this case, it is thought that an oligomer having an aromatic hydroxyl end or a relatively low molecular weight polymer is produced. Since such oligomers having aromatic hydroxyl terminals also have an adverse effect on the polycondensation reaction of the present invention, it is important to suppress their formation as much as possible.

As described above, one of the features of the present invention is that when carrying out the self-polycondensation of the bisalkyl carbonate of an aromatic dihydroxy compound by dedialkyl carbonate, the reaction is carried out under conditions where the aromatic hydroxyl compound is substantially absent. (high molecular weight aromatic polycarbonate)
It is now possible for the first time to obtain it.

Therefore, when carrying out the method of the present invention, it is necessary to carry out the process under as few conditions as possible such that aromatic hydroxyl compounds are not substantially present. An aromatic polycarbonate is obtained, and since the degree of polymerization that can be achieved within a predetermined time is limited depending on the amount of the compound present, an acceptable amount can be selected depending on the required degree of polymerization. Generally, the weight average molecular weight of industrially useful aromatic polycarbonates is about 6,000 to 100,000, preferably about 10,000 to 50,000. In this case, the permissible amount of the aromatic hydroxyl compound is usually about 100% of the hydroxyl group relative to the aromatic skeletal unit (-Ar- in the general formula (I)) of the aromatic polycarbonate to be produced. It is selected in the range of 5 molar or less, preferably about 2 molar or less, and even more preferably about 10 molar or less.

As described above, the present invention is capable of producing a high molecular weight aromatic polycarbonate by self-polycondensing a bisalkyl carbonate of an aromatic dihydroxy compound under conditions substantially free of aromatic hydroxyl compounds. In addition to this feature, one or more metal elements selected from metal elements and their compounds belonging to groups IB, mB, IVA, and Another major feature is that the reaction rate is increased by conducting the reaction in the presence of a catalyst.

By combining these two features, the method of the present invention enables the easy production of high molecular weight aromatic polycarbonates.

The polymerization catalyst used in the method of the present invention is selected from metal elements and compounds thereof belonging to groups IIB, mB, ■A, and ■B of the periodic table. Examples of metal compounds used as catalysts include Zn(OAc)2, Zr)
Zinc carboxylates such as (OBz)2 + ZnF2.
ZnCl2. , ZnBr2. /'t such as Zn work 2
Zinc rogenide Zinc nO03, Zn (No3)2. Zn
Zinc inorganic acid salts such as SO4, Zn3(I”04)2,
(NH4)2[ZnC14].

C(CH3)4N)2 CZnCt4), [Zn(
en)3]X2.

[Zn(en) ] Zinc complex compounds such as X2, Zn
○.

Zinc oxide or sulfide such as ZnS, Zn(OH)2
Zinc hydroxides such as (C2H5)2Zn, Ph
2Zn.

C2H5ZnOC2H5, PhZn07. PhZnO
Ac, organic zinc compounds such as C4H9ZnOAc, Z
n(002H5)2. Zinc alkoxides or alkoxides such as Zn(OPh)2, Zn(acac)2.
Zinc chelate compounds such as Zn(oxin)2 + Zinc compounds such as Cd(OAc)2.

C! cadmium carboxylates such as d(OBz)2,
Cadmium halides such as 0dF2.0dOt2.0dBr2, ca(ca5)2. cd(No3)2.
Inorganic acid salts of cadmium, such as cdsO4, ca3(I2O3)2, K[cdct5].

[cd(on)3]X2. Cadmium complex compounds such as 2[cd(cN)4], cadmium hydroxides such as cid(OH)2, (C4H9)2caph2ca
, phcacz.

C! Organic cadmium compounds such as 4HpOdOAe, Cd(OC2H5)2. Alkoxide or aryloxide of cadmium such as ca(oph)2, Cd(a
Cadmium chelate compounds such as cac)2゜04(oxin)2.

Cadmium compounds such as At(OAc)3.

Carboxylate salts of aluminum such as At (OB Z ) 3, Al013. Aluminum halides such as AtBr3, At2(Co3)3. Az(N
O3)3. Inorganic eU of aluminum such as Al:2(SO4)3, Na3[iF6].

(NH4) 3 [AAF6] and other aluminum complex compounds, AtNa(SO4)2 , At(NH4) (
804) Anhydrous alum such as 2, At203
Oxides of aluminum such as At(OH) 3
Aluminum hydroxides such as ph3Az, organoaluminum compounds such as Aj(OOH3)3. A
t(003H7-i)3. Alkoxides or aryoxides of aluminum such as At(OPh), At(
acac)3. Aluminum compounds such as aluminum chelate compounds such as A7(oxin)3;
Ga(OAC)3. Ga(OBz), Ga0(O
Ac).

Gallium carboxylates such as Ga(OH) (OAc)2, GaF3. Gallium halides such as Ga0t3, gallium inorganic acid salts such as Ga2(S04)3, KGa(S04)2. (NH4) [Ga
gallium complex compounds such as [F6], gallium oxides such as Ga2O3, gallium hydroxides such as Ga(OH)3, (OH3) 3Ga.

Organic gallium compounds such as Ph3Ga, Ga(OCH3
) 3° Gallium compounds such as gallium alkoxides or aryloxides such as Ga(OPh)3, gallium chelate compounds such as Ga(acac)3;
In(OAc)3 Indium carboxylate,
InF3. Indium halides such as In0t5, In2(CO3)3. In(NO3)37 Inorganic acid salts of indium, oxides of indium such as In203, (02H5)3, Ph3, Ph2
Organic indium compounds such as In(aca'
c) Compounds of indium such as chelate compounds of indium such as 3; Ge(OAc)4. Ge(O
Germanium carboxylates such as Bz)4, GeF
2. GeF4. Germanium halides such as GeC12 and Ge014, germanium oxides such as 0802, Ge(OH)2. Hydroxides of germanium, such as Ge(OH)4, (02H5)4Ge.

Ph4Ge, (04H9)2GeX2. Ph5GeX,
Ph2GeX2゜[(04H9)2GeO],, [P
Organogermanium compounds such as h2GeO]n, Ge
(OOH3)4. Ge(OPh)4 etc. (7M#
- v nium alkoxide or aryloxide, Ge(
acac)20t2, K[GaF3], (NH4)2[
Germanium complex compounds such as Ge0t6]; Germanium compounds such as Efn(OAC)2,5n(
tin carboxylates such as OAC) 4°5n(OBz)2.5n(OBz)4, 5nO42, 5nOj4. S
710 genides of tin, such as nBr4, (04H
9) Organic tin 7% ride such as 2SnC42, (04H9)3SnOA, (02H5)4Sn, Ph4Sn
Organotin compounds such as (04H9)2SnO, [:(
04H9)2snO],,'C(CaH+7)2sno
]n, organotin oxides such as [(c4H9)phsno]n, (04H9)28n(OAC)2. Organotin carboxylates such as dibutyltin laurate, S
Tin oxides such as nO, 5n02, tin hydroxides such as Sn(OH)2゜5n(oH)4, Eln(OOH
3) 2゜5n (OOH) 3.5n (004H9) 4.5
n(OF'h)2.5n(OPh)4゜(c4a9)2
tin and organotin alkoxides or aryloxides such as sn(OOH3)2, inorganic salts of tin such as 5nS04, Na[5nF3:), [(C2H5)4N
][5n043], Oa[5n(OAc)3
]2, tin complex compounds such as 5n022 (acac
)2 and tin compounds such as Pb(OAC)2.

Pb(OAc)4. Lead carboxylates such as Pb(OBz)2, PbO22, Pb0t4. PbBr2'
fl Which lead halide, PbC! 03.2P'bC
O3・pb(oH)2. pbso4゜pb(so4)
2. Inorganic acid salts of lead such as Pb(NO3)2, K2[P
bO46], lead complex compounds such as Na2[Pb(OH]6], lead oxides such as pbo, , pbo2.Pb3O4, lead hydroxides such as Pb(OH)2, (0
4H9) 4Pb, ph'4pb.

(c2u5)5pbcz, ph3pbaz, (02
H5)2PbC42゜(C2H5)5Pb(OAC)
Organic lead compounds such as Pb(OCH3)4: pb
(oph)4, (c4a9)2pb(oph)2 and other lead and organolead alkoxides or aryloxides,
Lead compounds such as Ti(QC!H3)4゜Ti(
004H9)4. Titanium alkoxides or aryloxy groups such as Ti(OPh)4, TiCl2. TiC
74°TiF4. Titanium halides such as TiBr2, Ti(NO3)4. Inorganic acid salts of titanium such as Ti2(804)3, R2[TIF6], CNH
4) Titanium complex compounds such as 2CTi, O16], Ti
e, oxides of titanium such as TiO2, (PhCH2)
3TiO4, (PhC!H2)2Ti(OC2H5)2
゜Ti(π-C5H5)2. TICt2(π-C5H5
)2. Ti(OH3)2・(π-05H5)2
Titanium compounds such as organic titanium compounds such as, titanium chelate compounds such as Tio(acac)2;
Zr(OAc)4. Zirconium carboxylates such as Zr(OBz)4, ZrF4゜Zr0L4, Zr
Br4 Nato zirconium halide, Zr(
SO4)2. Inorganic acid salts of zirconium such as Zr(NO3)20, R2II ZrF6], C(02
H5)2NH2]2[ZrC16], [ZrCl1
(CH3CN)2 ] and other complex compounds of didizirconilla,
Zirconium oxides such as ZrO2, Zr(004H
9)4. Zirconium alkoxides or oxides such as Zr(OPh)4, ZrCt(OH2Ph)
5. Zr(C!4H9)4. ZrCl2(CH3
)2°[ZrC1(yr 05H5), 2]20. Z
rC42, (yr 05H5).

Zr(OAc)5(yr-C5H5), ZrH2(i
-C5H5)2 and other organic zirconium compounds, Z
Examples include zirconium chelate compounds such as r(acac)4 (where Ac represents an acetyl group, BZ represents a benzoyl group, on represents ethylenediamine, ph represents a phenyl group, and a
cac represents acetylacetone, oXln represents 8-quinolitool, π-C5H5 represents π-coordinated cyclopentadienyl group, and X represents halogen, alkoxy group, or aryloxy group).

These catalysts may be used alone or in combination of two or more. In addition, the amount of these catalysts used is
It is usually selected in a range of 0.00001 to 10 weight percent, preferably 5 to 5 weight percent, based on the bisalkyl carbonate of the aromatic dihydroxy compound as a raw material. Furthermore, among these catalysts, Zn, At, S
n, Ti and compounds thereof are preferably used.

Bisalkyl carbonate esters of aromatic dihydroxy compounds that can be used as raw materials in the method of the present invention are:
General formula % Formula % () R1 and R2 in the formula (I) each represent a lower alkyl group or a cycloalkyl group having n 1 to 6 carbon atoms, such as methyl, ethyl, propyl (various), butyl ( (various), amyl (various), hexyl (various), lower alkyl groups, cyclopropyl, cyclopentyl, methylcyclopentyl, cyclohexyl, etc. with 3 or more carbon atoms
6, 7-chloroalkyl group, etc. Further, these lower alkyl groups or cycloalkyl groups may have substituents that do not adversely affect the reaction, such as halogen atoms, lower alkoxy groups, nitrile groups, ester groups, etc. It may have an unsaturated bond. R1 and R2 may be the same or different, but from the viewpoint of ease of preparation of raw materials, it is more preferable that they are the same.

Ar represents all divalent aromatic residues of aromatic dihydroxy compounds, and examples of such aromatic groups include phenylene (various), naphthylene (various), biphenylene (various), and pyridylene (8 each). , a divalent aromatic group represented by the general formula % (), and the like.

Here, Ar' and Ar2 are divalent aromatic groups which may be the same or different, and include, for example, phenylene (various types), naphthylene (each $4), biphenylene (
Represents groups such as (various), pyridylene (various), etc. 2 is a simple bond, -〇-, -CO-.

(Here, R3, R4, R5, and H6 may be the same or different and represent hydrogen, a lower alkyl group, a lower alkoxy group, or a cycloalkyl group, and k represents an integer from 3 to 11).

Furthermore, such a divalent aromatic group (Ar or Ar
1+ Ar2), one or more hydrogen atoms are substituted with other substituents that do not adversely affect the reaction, such as halogen atoms, lower alkyl groups, lower alkoxy groups, phenyl groups, phenoxy groups, vinyl groups, cyan groups, and esters. f17' (may be substituted with a group, an amide group, a nitro group, etc.).

Such a bisalkyl carbonate of an aromatic dihydroxy compound may be produced by any method, for example, by reacting a corresponding aromatic dihydroxy compound with a dialkyl carbonate, or by reacting an aromatic dihydroxy compound or its alkali. It can be easily obtained by reacting a metal salt with a halogenated formic acid alkyl ester. However, if more than a predetermined amount of aromatic hydroxyl compounds remain in the polymerization raw material obtained by such a method, the aromatic hydroxyl compounds can be extracted into the aqueous solution as an alkali metal salt by washing with an aqueous alkaline solution. After separation, by methods such as drying,
It is necessary to reduce the amount of aromatic hydroxyl compounds to a predetermined amount or less.

Examples of such bisalkyl carbonate esters of aromatic dihydroxy compounds include bismethyl carbonate, bis(methyl carbonate) of 4- and droxyphenol, bis(methyl carbon, i, -)) of 3-hydroxyphenol, 1,1-bis(4-hydroxyphenyl)-butane bis(methyl carbonate), bis(
4-hydroxyphenyl)-methane bis(methyl carbonate), 2-methyl-1,1-bis(4-hydroxyphenyl)-propane bis(methyl carbonate)
, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)-propane bis(methyl carbonate), bis(3,5-dimethyl-4-hydroxyphenyl)-sulfone bis(methyl carbonate), bis (3,5-
Bis(methyl carbonate) of dimethyl-4-hydroxyphenyl)-ether, bis(methyl carbonate) of 4,4'-dihydroxybenzophenone, bis(methyl carbonate) of 1-bis(4-hydroxyphenyl)-ethane, Bis(methyl carbonate) of 1-ethyl-1,1-bis(4-hydroxyphenyl)-propane
)), bis(methyl carbonate) of 1.1-bis(4-hydroxyphenyl)-cyclohexane, bis(methyl carbonate) of 1.1-bis(4-hydroxyphenyl)-cyclododecane, bis(4-hydroxyphenyl) )-phenylmethane bis(methyl carbonate),
bis(4-hydroxyphenyl)-naphthylmethane bis(methyl carbonate), bis(4-hydroxyphenyl)-(41noglobylphenyl)-methane bis(
methyl carbonate), 2,2-bis(4-hydroxyphenyl)-propane bis(methyl carbonate)),
2.2-bis(4-hydroxyphenyl)-butane bis(methyl carbonate), 2.2-bis(4-hydroxyphenyl)-hexane bis(methyl carbonate), 2,2-bis(3,5- cyclo-4-hydroxyphenyl)-propane bis(methyl carbonate),
2.2-bis(4-hydroxyphenyl)-pentane bis(methyl carbonate), 2,2-bis(4-hydroxyphenyl)-nonane bis(methyl carbonate), diphenyl-bis(4-hydroxyphenyl) -methane bis(methyl carbonate), 4-methyl-2,
2-bis(4-hydroxyphenyl)-pentane bis(methyl carbonate), 4.4-bis(4-hydroxyphenyl)-hebutane bis(methyl carbonate)
, 1-naphthyl-1,i-his(4-hydroxyphenyl)-ethane bis(methyl carbonate), ■-phenyl-1.1-bis(4-hydroxyphenyl)-ethane bis(methyl carbonate), 2- Cyclohek'
l/l/-4-(4-hydroquinphenyl) isoflovirphenol bis(methyl carbonate), 2-methoxy-4-(4-hydroxyphenyl)isopropylphenol bis(methyl carbonate), 1.2 -bis(4-hydroxyphenyl)-equun bis(methyl carbonate)), 2.2-bis(3-chloro-4-hydroxyphenyl)-propane bis(methyl carbonate), 2-isopropyl-4-( 4-hydroxyphenyl)isopropylphenol bis(methyl carbonate), 2,2-bis(3-methyl-4-hydroxyphenyl)-propane bis(methyl carbonate), 2,2
-bis(3-fluoro-4-hydroxyphenyl)-propane bis(methyl carbonate), 1,10-bis(4-hydroxyphenyl)-decane bis(methyl carbonate), bis(3,5-')' I-rho 4-hydroxyphenyl)-methane bis(methyl carbonate), 2,2-bis(3,5-sifcomo-4-hydroxyphenyl)-propane bis(methyl carbonate)),
1.1-Bis(3,5-dichloro-4-hydroxyphenyl)-cyclohexane bis(methyl carbonate)
, bis(4-hydroxyphenyl) sulfide bis(
Bis(methyl carbonate) of bis(3-methyl-4-hydroxyphenyl) sulfide, bis(methyl carbonate) of bis(4-hydroxyphenyl) sulfoxide, bis( of bis(4-hydroxyphenyl)-sulfone) methyl carbonate), bis(methyl carbonate) of bis(3-chloro-4-hydroxyphenyl)-sulfone, bis(methyl carbonate) of ethylene glycol-bis(4-hydroxyphenyl) ether, 1,4-bis(4- Hydroxyphenyl)-butane bis(methyl carbonate), 1.4-
Bis(4-hydroxyphenylisoglobyl)-benzene bis(methyl carbonate), ■, 4-bis(3-
Chloro-4-hydroxyphenyl)-benzene bis(
methyl carbonate), bis(4-hydroxyphenyl)ether bis(methyl carbonate), 1,4-bis(4-hydroxyphenoxy)-benzene bis(methyl carbonate), 1,4-bis(4-hydroxyphenylmethyl) )-benzene bis(methyl carbonate), 1,4-bis(4-hydroxyphenylsulfonyl)-benzene bis(methyl carbonate-1.), bis(
3,5-dimethyl-4-hydroxyphenyl)-methane bis(methyl carbonate), bis(3,5-dimethyl-4-hydroxyphenyl)-sulfide, bis(methyl carbonate), 3.3', 5.5 Examples include bis(methyl carbonate) of '-tetramethyl-4,4'-dihydroxybenzophenone.

In addition, bisethyl carbonate esters in which the methyl group of the above bismethyl carbonate ester is replaced with an ethyl group, bisamyl carbonate esters in which various propyl groups are replaced, bisbutyl carbonate esters in which various butyl groups are replaced, and bisamyl carbonates in which various amyl groups are replaced. Esters, those with an alkyl group having 2 to 6 carbon atoms such as bis-hexyl carbonate esters in place of various hexyl groups, biscyclopentyl carbonate esters in place of cyclopentyl group, biscyclohexyl carbonate esters in place of cyclohexyl group, etc. number 3~6
Those having a cycloalkyl foundation of

Furthermore, in dialkyl carbonate esters having different alkyl groups, such as the above-mentioned bismethyl carbonate esters,
One methyl group has 2 carbon atoms other than a methyl group such as an ethyl group, various propyl groups, various butyl groups, cyclohexyl group, etc.
Asymmetric dialkyl carbonates substituted with ~6 alkyl or cycloalkyl groups can also be used.

These bisalkyl carbonate esters may be used alone or in combination of two or more. In addition, among these bisalkyl carbonates, when two or more types of bisalkyl carbonates having different aromatic residues of the aromatic dihydroxy compound are used, a copolymer having the skeletons of these two or more types is used. An aromatic copolycarbonate is obtained.

In the method of the present invention, the reaction temperature and reaction time when carrying out the self-polycondensation reaction are determined by the type of bisalkyl carbonate of the aromatic dihydroxy compound used as the raw material,
Although it varies depending on the type and amount of the catalyst used, the desired degree of polymerization of the polycarbonate to be produced, and other reaction conditions, it is usually 20 to 350°C, preferably 120 to 350°C.
The self-polycondensation reaction is carried out by heating at a temperature in the range of 20° C., usually for several minutes to several tens of hours, or in a trench for about 10 minutes to 30 hours.

Further, the self-polycondensation reaction may be carried out without using a solvent, or a solvent that is insoluble in the reaction and has a large dissolving power for the polycarbonate to be produced, such as methylene chloride, chloroform, 1.2- Although it may be carried out using dichloroethane, tetrachloroethane, dichlorobenzene, tetrahydrofuran, dioxane, diphenylmethane, etc., it is usually carried out without a solvent.

Furthermore, in the method of the present invention, when carrying out the self-polycondensation reaction, it is preferable to remove the dialkyl carbonate produced in the reaction from the reaction system in order to increase the polymerization rate.
For this purpose, for example, a method of introducing an inert gas such as nitrogen, argon, helium, or carbon dioxide into the reaction system to entrain the diaryl carbonate If produced, a method of conducting the reaction under reduced pressure, or a combination of these methods are available. The methods described above are preferably used.

In carrying out the reaction, the reactor may be of a batch type or a flow type. In addition, when conducting a flow reaction using multiple reactors, the temperature may be varied for each reactor, and when conducting under reduced pressure, the degree of reduced pressure may be changed. .

Effects of the Invention In the phosgene method, which is an existing industrial method for producing aromatic polycarbonate, by-products containing electrolytes such as sodium chloride and chlorine are produced, and these impurities are inevitably contained in the resin. Since these impurities have a negative effect on the physical properties of the resin, the phosgene method requires complex and expensive cleaning and removal steps to completely reduce their content in the resin. It is impossible to remove it.

On the other hand, the aromatic polycarbonate obtained by the method of the present invention does not contain any such impurities.
The method of the present invention is industrially advantageous not only because it is superior in quality but also because it does not require a troublesome step of separating these.

In addition, since the method of the present invention usually carries out the self-polycondensation reaction without using a solvent, like the phosgene method,
This method can be said to be industrially advantageous from this point of view as it does not require complicated steps such as separation and recovery of a large amount of solvent.

Furthermore, in the case of so-called transesterification reactions and self-polycondensation reactions of bisaryl carbonate esters of aromatic dihydroxy7 compounds, phenols and diaryl carbonates that have reaction activity and have high boiling points are removed at high temperature and under high vacuum. However, in the method of the present invention, the by-product is a neutral and low-boiling lower dialkyl carbonate with low reaction activity, so this by-product can be easily removed from the reaction system. It is also extremely advantageous industrially.

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, the molecular weight was shown by the value of weight average molecular weight (Mw).

In addition, the polymerization reaction equipment should be carefully deoxidized and dried.
In addition, a reactor was used that was devised to minimize the contamination of oxygen, water, etc. during the reaction.

Furthermore, the amount of aromatic hydroxyl groups in the product was measured by NMR analysis, IR analysis, etc., and the molar ratio of line b1 showed a value of (-0''/-).

r- Example 1 (1) Bismethyl carbonate ester of bisphenol A 2.2-His(4-hydroxyphenyl)propane (
Bisphenol A) 228f, dimethyl carbonate) 3
9. Put dibutyltin oxide 52 into an autoclave, raise the reaction temperature to 160°C, and then add dry nitrogen gas into the solution at a rate of 500 NA/hr while stirring and keeping the reaction pressure at 7K9/C+4. While bubbling, the generated methanol and accompanying dimethyl carbonate were distilled off.

At the same time, dimethyl carbonate was added at 300f from another nozzle.
/hr to the autoclave.

After 10 hours, the reaction solution was cooled and analyzed. As a result, the reaction rate of bisphenol A was 99.5%, the yield of bismethyl carbonate of bisphenol A was 95%, and the yield of monomethyl carbonate of bisphenol A, which was an intermediate, was 4%. .5% was produced. By washing the reaction solution with a dilute aqueous alkali solution, a small amount of unreacted bisphenol A1 and monomethyl carbonate of bisphenol A were almost completely removed.

Next, dimethyl carbonate and water were distilled off to obtain bispheno-/l/A bismethyl carbonate which was substantially free of a compound having an aromatic hydroxyl group and water. By recrystallizing this with hexane, highly purified bismethyl carbonate ester of bisphenol A 3102 containing no catalyst was obtained.

The amount of aromatic hydroxyl compound present in this was less than 0.1 molar.

34.49 (0.1 mol) of bismethyl carbonate of bisphenol A produced above and 10 μm of dibutyltin oxide were placed in a reaction apparatus equipped with a stirrer, a thermometer, and a pressure gauge, and heated in a heating bath to It was heated to 240°C. During this time, the pressure in the system was gradually reduced, and finally
The temperature was maintained at 0.01 nmHg. Dimethyl carbonate distilled out as the reaction progressed was cooled and trapped in a dry acetone bath. 2 hours, 5 hours, 7 hours of this reaction
The results after hours are shown in Table 1. The molecular weight of the polycarbonate was measured by GPO analysis of a methylene chloride-tetrahydrofuran solution.

The obtained polycarbonate of bisphenol A was colorless and transparent, and of course, chlorine ions and compounds containing chlorine were not present.

A self-condensation reaction of bismethyl carbonate of bisphenol A produced in (1) of Example 1 was carried out for 5 hours in the same manner as in Example 1 except that the reaction temperature and reaction pressure were changed. The results are shown in Table 3. In all cases, the amount of hydroxyl groups present was 0.3 molar or less.

Table 3 Comparative Example 2 Example 4 was prepared using raw materials with the same composition as used in Comparative Example 1.
Although the polymerization reaction was carried out under the same conditions as above, the average molecular weight Mw of the product was only 3,800. Note that the amount of hydroxyl groups present was about 6 moles.

Example 5 228 f of bisphenol A, 4 to 9 of diethyl carbonate, and 10 f'i of dibutyltin lauray were placed in an autoclave and reacted in the same manner as in Example 1 (1). In this case, diethyl carbonate'ii
It was supplied at a rate of 350 r/hr, and the reaction pressure was 5 K9/hr.
It was maintained at cr/l. After 15 hours, the reaction was stopped and the reaction solution was analyzed. As a result, the reaction rate of bisphenol A was 99.8%, the yield of bisethyl carbonate of bisphenol A was 96%, and the intermediate monoethyl carbonate of bisphenol A was obtained. was generated at 3.8%. By purifying in the same manner as in Example 1, bisphenol A and bisethyl carbonate 3402 with a high purity of less than 1 molar ratio of bisphenol A and monoethyl carbonate of bisphenol A was obtained.

(2) Synthesis of polycarbonate of bisphenol A 37.2 f (0.1 mol) of the bisethyl carbonate of bisphenol A prepared above and 8 μm of tin acetate were placed in a reactor similar to that used in Example 1. 280℃,
As a result of the reaction under conditions of 511,111 Hg and stirring for 5 hours, bisphenol A polycarbonate having an average molecular weight of 35,000 was obtained almost quantitatively. Note that the amount of hydroxyl groups present was 0.4 molar or less.

Comparative Example 3, Example 6 37.25' (0.1 mol) of bisethyl carbonate of bisphenol A produced in (1) of Example 5, 8 cm of tin acetate, and bisphenol A as a compound having an aromatic hydroxyl group. Polymerization was carried out in the same manner as in Example 5 by adding a predetermined amount of monoethyl carbonate. The results are shown in Table 4.

Table 4 Examples 7 to 16 Substantially free of compounds having aromatic hydroxyl groups, using various aromatic dihydroxy compounds in place of bisphenol A, by the same method as in Example 1 (1) The corresponding bismethyl carbonate ester with high purity was obtained.

Using these bismethyl carbonate esters as raw materials, a self-condensation reaction was carried out in the same manner as in Example 3. The results are shown in Table 5. The obtained aromatic polycarbonate had a skeleton structure corresponding to the aromatic dihydroxy compound as the raw material.

7', / to 7' Table 5 = 48 = In all cases, the amount of aromatic hydroxyl groups present was 0.5 molti or less.

Example 17 Using the same apparatus as in Example 1, using 34.4 F (0.1 mol) of bismethyl carbonate of bisphenol A produced in (1) of Example 1 and 5 rrq of zinc acetate, the mixture was heated at 290°C. , 2011111Hg for 6 hours, a colorless and transparent polycarbonate having an average molecular weight (Mw) of 45,000 was quantitatively obtained.

Examples 18-26 Bismethyl carbonate ester of bisphenol A produced in Example 1 (1) 34.4? A polycarbonate of bisphenol A was obtained in the same manner as in Example 16 using , and various catalysts. The results are shown in Table 6.

Table 6 Note that in both cases, the amount of aromatic hydroxyl groups is 0.
．． It was less than 6 molar.

Example 27 Using 34.4 f of bismethyl carbonate of bisphenol A produced in (1) of Example 1 and 5 myf of butyltin trimethoxide, at 200 to 240°C for 3 hours, 250 to
The reaction was carried out at 280° C. for 5 hours with stirring.

In this example, instead of reducing the pressure, we deoxidize and
Dry argon f 10 Nj/hr heated to 0° C. was introduced. The average molecular weight (Mw) of the obtained bisphenol A polycarbonate was 31,000.

The amount of aromatic hydroxyl groups present after polymerization was 0.5 molar or less.

Example 28 Bismethyl carbonate ester of bisphenol A produced in Example 1 (1) 17.29, bis(315-dimethyl-4-hydroxyphenyl)sulfone used in Example 15 21.12, sibutyl susimethoxy Do 1 (lIL
ji for 5 hours at 280°C and 10 mmHg, the average molecular weight (Mw) was approximately 32.0.
00, a random copolycarbonate consisting of approximately 1:1 ratio of (A) and (B) was obtained.

In both cases, the amount of aromatic hydroxyl groups is 0.
．． It was less than 6 molar.

Claims (1)

[Claims] 1 General formula▲ Numerical formula, chemical formula, table, etc.▼…(I) (In the formula, R^1 and R^2 are each a lower alkyl group or a cycloalkyl group having 1 to 6 carbon atoms. Yes, they may be the same or different from each other, A
When producing an aromatic polycarbonate by self-polycondensing bisalkyl carbonate of an aromatic dihydroxy compound represented by (r is a divalent aromatic group), IIB, IIIB, IVA, and IVB of the periodic table are used. Production of an aromatic polycarbonate, characterized in that the reaction is carried out in the presence of at least one catalyst selected from metal elements belonging to the group A and their compounds, and under conditions in which aromatic hydroxyl compounds are substantially absent. Method. 2. The method according to claim 1, wherein the catalyst is at least one selected from Zn, Al, Sn, Ti, and compounds thereof. 3. The method according to claim 1 or 2, wherein the polycondensation reaction is carried out using a raw material substantially free of a compound containing an aromatic hydroxyl group or a compound that produces an aromatic hydroxyl group under the reaction conditions. 4. The method according to claim 1, 2 or 3, wherein R^1 and R^2 in general formula (I) are a methyl group or an ethyl group. 5. The method according to claim 1, 2, 3 or 4, wherein the aromatic dihydroxy compound is 2,2-bis(4-hydroxyphenyl)propane.