JP2001253944A - Method of producing mixture of aromatic cyclic carbonates and linear polycarbonate from the mixture of aromatic cyclic carbonates - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a mixture of aromatic cyclic carbonates good in reactivity (2) in good yield (1) from an aromatic polycarbonate resin, and to obtain an aromatic polycarbonate resin good in reactivity (3) and good in color tone and thermal deterioration and hydrolytic resistances (4) from the mixture of the aromatic cyclic carbonates produced by the method. SOLUTION: This method of producing the aromatic polycarbonate mixture comprises a first step of reacting the aromatic polycarbonate in a solvent, and producing a reactional solution containing the mixture of the aromatic cyclic carbonates, and a second step of separating the mixture of the aromatic cyclic carbonates from the reactional solution and the aromatic polycarbonate in the first step satisfies the following (1) to (4). (1) 10,000-60,000 viscosity- average molecular weight and 2.0-3.0 Mw/Mn, (2) <=30 ppm content of phosphorus compounds expressed in terms of phosphorus element, (3) <=0.01 wt.% moisture content and (4) terminal groups of the polycarbonate consisting substantially of an aryloxy group and a phenolic OH group in which the content of the phenolic OH group is 5-50 mol% based on the whole terminal groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an aromatic cyclic carbonate mixture comprising: 1) a good yield; 2) a good reactivity of an aromatic cyclic carbonate from an aromatic polycarbonate resin;
A mixture of aromatic cyclic carbonates of good quality and good reactivity produced by the method, III) better than the mixture of aromatic cyclic carbonates, 3) better reactivity, 4) color tone, heat deterioration resistance, hydrolysis resistance The present invention relates to IV) and a good quality aromatic polycarbonate resin obtained by the polymerization method.

[0002]

BACKGROUND OF THE INVENTION A conventionally known method for producing aromatic cyclic carbonates is disclosed in U.S. Pat. No. 4,644,053.
Publication, Macromolecules 1991, V
ol. 24 p3035-3044 or Tokuhei 7
As described in -3751, a method of hydrolyzing and condensing mono- or oligocarbonate bischloroformate, or a method of cyclizing a monochloroformate of oligocarbonate has been proposed. Each of these production methods is easy to operate,
It has characteristics such as good and low yield of the target product.

[0003] However, in any case, it is common to use chloroformates as raw materials. That is, when producing the chloroformates, toxic phosgene must be used in any case, and there is no effective method for producing such chloroformates without using phosgene. It is. Thus, with the current increasing environmental safety, these methods, which presuppose the use of such toxic phosgene, remain processes with environmental safety concerns.

[0004] Further, the following literature describes that aromatic cyclic carbonates are thermally decomposed from polycarbonate by an ionic reaction mechanism. 1) Foti et al. : J. Polym. Sci.
Polymer Chemistry Ed, 21 1
567 (1983) 2) G.I. Montaudo, C .; Puglisi,
F. Samperi: Poly. Deg. And S
tab. 26 285 (1989) 3) G.I. Montaudo, C .; Puglisi, R .;
Rapisardi, F.R. Samperi: Poly.
Deg. And Stab, 31 163 (199
1)

According to these descriptions, in principle, aromatic cyclic carbonates can be obtained directly from polycarbonate without using phosgene. However, the methods described in the above-mentioned documents are reaction-mechanical, and unfortunately, they have not been practically used for the synthesis and production of aromatic cyclic carbonates.

[0006] The production of aromatic cyclic carbonates from polycarbonate is described as Poly Polycarbonate.
m. Material Sci. Eng. Vo
l. 67 457-458 (1992). According to the above literature, polycarbonate (PC) is dissolved in tetrahydrofuran (THF) at a concentration of 0.25 wt%, and in the presence of a cesium hydroxide (CsOH) catalyst, PC, catalyst molar ratio: PC / CsOH = 333, reaction temperature It is described that the reaction was carried out at 50 ° C. to obtain an aromatic cyclic carbonate with a maximum yield of 72%. However, in order to improve the yield of aromatic cyclic carbonates, P
When the C concentration is increased to 0.5%, 1.0%, and 3%,
The aromatic cyclic carbonate yields were 67% and 56%, respectively.
%, 39%.

By the way, under the conditions giving the highest yield, 10
Even if 50 kg of the solvent is used in the 0 L reaction vessel, the amount of polycarbonate that can be used for the reaction is only 125 g, and the yield of the obtained aromatic cyclic carbonate is only 99 g at most, which is a practical amount. This cannot be said to be a method for producing group-cyclic carbonates. Furthermore, the polymerization reactivity of the aromatic cyclic carbonate obtained by this reaction also varies depending on the raw materials used, and is not always good.

[0008] Aromatic polycarbonates are widely used for various purposes due to their excellent transparency, heat resistance, etc. At present, an interfacial polymerization method using phosgene and a methylene chloride solvent is widely used as a production method. Have been.

However, the load of the phosgene or methylene chloride on the environment has become a problem, and a melt polymerization method using a carbonic acid diester, particularly diphenyl carbonate, as a carbonate-binding precursor, or a solid-phase polymerization method has attracted attention. However, in order to produce polycarbonate with a high degree of polymerization by melt polymerization or solid state polymerization, it is necessary to maintain high vacuum conditions under high temperature conditions for a long time, and in order to satisfy such conditions, large equipment must be used. I need.

On the other hand, the polymerization of the polycarbonate from the aromatic cyclic carbonate is carried out under extremely simple conditions, that is, in the presence or absence of a catalyst, simply by subjecting the aromatic cyclic carbonate to 200 ° C. or higher. ,
It can be carried out only by heating for several tens of minutes, and has an advantage that a polycarbonate having a high degree of polymerization can be obtained extremely easily. The synthesis of a high polymerization degree polycarbonate from an aromatic cyclic carbonate is described in Macromolecule described above.
s 1991, 24, 3035-3044 and the like.

Therefore, there is a demand for a method for producing aromatic cyclic carbonates having a high reactivity and a high reactivity with the aromatic cyclic carbonates safely and in good yield.

[0012]

SUMMARY OF THE INVENTION As described below, the present inventors have prepared a polycarbonate having a specific content of impurities or less, a specific terminal group structure and a specific molecular weight distribution as a raw material. It has been found that the use thereof can improve the yield of aromatic cyclic carbonates in the reaction for producing a mixture of aromatic cyclic carbonates. Furthermore, by using such a polycarbonate as a raw material, the quality of the obtained aromatic cyclic carbonate is good, and when polymerization and polymerization are performed, the polymerization activity is good, and the physical properties of the obtained polymer, especially It was found that the color tone, heat deterioration resistance and hydrolysis resistance were good.

That is, a first object of the present invention is to provide a method for producing a mixture of aromatic cyclic carbonates at a high yield from an aromatic polycarbonate as a raw material.
Still another object of the present invention is to provide an aromatic cyclic carbonate mixture which has good activity during polymerization and gives a polymer having good color tone, heat resistance and hydrolysis resistance.

[0014]

According to the present invention, the main repeating unit is represented by the following formula (1):

[0015]

Embedded image

(Wherein R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms or a carbon atom 6
W is an alkylidene group having 2 to 10 carbon atoms, an alkylene group having 1 to 10 carbon atoms, a cycloalkylidene group having 6 to 10 carbon atoms, a cycloalkylene group having 6 to 10 carbon atoms, It is an arylene group having 6 to 10 carbon atoms, an alkylene group which may have a substituent having 1 to 10 carbon atoms, an oxygen atom, a sulfur atom, a sulfoxide group or a sulfone group, or a direct bond. In the method for producing an aromatic cyclic carbonate mixture from the aromatic polycarbonate represented by the above), the aromatic polycarbonate is reacted in a solvent in the presence of an alkali metal compound catalyst to form a reaction solution containing the cyclic carbonate mixture. It comprises a first step of producing and a second step of separating a mixture of aromatic cyclic carbonates from the reaction solution.

As used herein, the term "a mixture of aromatic cyclic carbonates" means a mixture consisting of a substantially cyclic substance such as a cyclic dimer, cyclic trimer and higher cyclic substance of carbonate.

Regarding the molecular weight and the molecular weight distribution of the aromatic polycarbonate in the first step, 1) the viscosity average molecular weight is 10,000 to 60,000, and Mn is the number average molecular weight in terms of polystyrene, and Mw is the weight average in terms of polystyrene. Those having a molecular weight ratio of Mw / Mn of 2.0 to 3.0 are used.

From the viewpoint of the reaction yield, the higher the viscosity average molecular weight is, the lower the yield of the linear oligomer is.
From the viewpoint of the reaction rate and the solubility of the polycarbonate in the solvent, the lower the molecular weight, the better. Therefore, polycarbonate having a viscosity-average molecular weight of 10,000 to 60,000 is preferably adopted from the balance of both viewpoints.

The value of the ratio Mw / Mn is important in the quality of the mixture of the aromatic cyclic carbonates. That is, when a raw material having a large value is used, the content of impurity components whose structure is unknown is increased in the obtained aromatic cyclic carbonates for unknown reasons, and as a result, the polymerization reaction does not proceed well, or An object of the present invention is to obtain a defective polymer in which the color tone, hydrolysis resistance or fluidity of a polycarbonate obtained by polymerizing the aromatic cyclic carbonate is reduced. Since the Mw / Mn value is a parameter related to the molecular weight distribution of the polycarbonate and does not indicate the presence or absence of any impurities, the above result is unexpected. It is strongly imagined that a large Mw / Mn value means that a large number of low molecular weight or high molecular weight components are contained. Therefore, such a low molecular weight or high molecular weight component is involved in some side reaction. Is estimated.

That is, it is preferable that the Mw / Mn value is small, but if it is smaller than 3.0, there is no practical problem. The lower limit of this value is exemplified by 1 as a theoretical value, but the theoretical value is practically unobtainable, and no difference is recognized even at about 1.5. In practice, it is easy to obtain those having a Mw / Mn value of 2.0 or more from the characteristics of the reaction mechanism for forming polycarbonate. However, even in practice, a value of about 2.2 can be used without any problem.

The object of the present invention can be achieved by using a raw material polycarbonate having 2) a phosphorus compound content of 30 ppm or less as a phosphorus element and 3) a water content of 0.01 wt% or less. I can do it.

In a still more preferred embodiment, the content of the metal compound other than the alkali metal element, the alkaline earth metal element, and the alkali (earth) metal is 2 ppm or less as an element, respectively, and the content of each of the nonmetal elements other than phosphorus and halogen is not more than 2 ppm. The content of the metal element-containing compound is 3 p each as an element.
pm or less, by using a polycarbonate having a halogen content of 30 ppm or less as a total amount of a halogen element, an aromatic cyclic carbonate generation reaction from an aromatic polycarbonate by an alkali metal catalyst proceeds at a sufficiently high reaction rate. , Reaction selectivity and reaction yield are also good.

In the present specification, these metal elements and nonmetal elements are classified according to the periodic table as described in, for example, Organometallic Chemistry-Basics and Applications-Akio Yamamoto, but they are particularly problematic in the present invention. N as a nonmetallic element,
S, Se, B, and As, and S and N as main objects.

Regarding the phosphorus content, 3
Since the use of a polycarbonate having a content of 0 ppm or less causes the reaction for forming an aromatic cyclic carbonate from an aromatic polycarbonate to proceed at a sufficiently high reaction rate, the reaction selectivity, and the reaction yield also become favorable. Preferred.

Phosphorus compounds, especially phosphites, are used as an antioxidant in commercial polycarbonates.
00 ppm (1 to 100 ppm as a phosphorus element) Further, since it is further added as a flame retardant, from the raw material polycarbonate having a high phosphorus content, the phosphorus content is removed in advance, and 30 pp as the phosphorus element is removed.
m or less, preferably 20 ppm or less, more preferably 10 ppm or less, particularly preferably 5 ppm or less. It is particularly preferable to keep the concentration at 1 ppm or less.

Regarding the water content in the aromatic polycarbonate, when the water content exceeds 0.01 wt%, the ring-opening reaction of the aromatic cyclic carbonate formed becomes dominant,
Undesired linear low polymer comes to be mixed in the obtained aromatic cyclic carbonate, as a result, the polymerization activity of the aromatic cyclic carbonate becomes poor, and as a polycarbonate produced from the aromatic cyclic carbonate mixture, Can be obtained only with a low degree of polymerization (i.e., intrinsic viscosity or a viscosity average degree of polymerization calculated from the viscosity), and further, with a poor level of color tone, heat deterioration resistance and hydrolysis resistance. It will be.

The water content in the polycarbonate is set to 0.01 w
It can be easily achieved by, for example, performing a drying treatment at a temperature of 110 to 150 ° C. for 1 to 10 hours under a vacuum condition of 13 × 10 ² Pa or less.

With respect to the halogen content, when the polycarbonate is produced using phosgene or a methylene chloride solvent, usually 1 to 30 pp is contained in the polycarbonate as a chloroformate or methylene chloride component.
m remaining and have an effect of inactivating the alkali catalyst. Therefore, the total amount of halogen elements is preferably 30 ppm or less, more preferably 20 ppm or less,
It is particularly preferable to set the value to 5 ppm or less. It is particularly preferable if the content is 1 ppm or less.

Phosphorus, an alkali metal element, an alkaline earth metal element, and a metal element other than an alkali (earth) metal,
In order to reduce the amount of impurity elements such as non-metallic elements and halogens to a specified value or less, specifically, polycarbonate is dissolved in a non-halogen solvent such as THF, and diluted with diluted alkaline water at room temperature or heated. After washing under conditions and, if desired, contacting with a chelating resin or an ion-exchange resin, a precipitation solvent such as methanol is added to precipitate and recover the polycarbonate once or several times. In addition, the amount of an impurity element such as an alkali metal element, an alkaline earth metal element, a metal element other than an alkali (earth) metal, a nonmetal element, and a halogen amount can be set within the above range.

When the value of these impurities exceeds the specified value, the reaction rate of producing an aromatic cyclic carbonate from an aromatic polycarbonate with an alkali catalyst becomes slow, and
Not only does the reaction selectivity and reaction yield decrease, resulting in unsatisfactory results, but also the stability of the resulting aromatic cyclic carbonate becomes poor, and the decomposition reaction easily occurs during storage. Further, the color tone of these aromatic cyclic carbonates is also poor, and the reactivity (polymerization rate) is also poor.

As the metal compound and the nonmetallic element-containing compound, those having the ability to coordinate with a compound having an unshared electron pair and those having the activity as a transesterification catalyst in the production of polyethylene terephthalate or polycarbonate are particularly preferable. Absent.

As a method of reducing these metal and nonmetal elements, for example, as described above, it is effective to combine the washing of a polycarbonate solution with a dilute alkaline aqueous solution and the treatment of a cation exchange resin. By this treatment, the element content of the alkali metal element, the alkaline earth metal element, and the metal compound other than the alkali (earth) metal in the polycarbonate is easily reduced to 2 ppm or less, and the content of the nonmetal element-containing compound other than phosphorus is easily reduced to 3 ppm or less. Can be value. By repeating several times, the concentration can be reduced to preferably 1 ppm or less, respectively, or more preferably 0.5 ppm or less, particularly preferably 0.1 ppm or less.

With regard to the molecular terminal group structure, use is made of a polycarbonate wherein the polycarbonate terminal groups substantially consist of aryloxy groups and phenolic OH groups, and the content of phenolic OH groups is 5 to 50 mol%. It is essential to use such a polycarbonate, whereby the reaction of generating an aromatic cyclic carbonate from an aromatic polycarbonate by an alkali catalyst proceeds smoothly. That is, in order for the reaction to proceed smoothly, it is necessary that the phenolic OH terminal group content is contained in an appropriate amount.

If the OH terminal group content is less than 5 mol%, the rate of the aromatic cyclic carbonate formation reaction is low,
It takes a long time for the reaction to proceed, during which time the aromatic cyclic carbonate causes a side reaction, which lowers the reaction selectivity and the reaction yield. When the terminal OH group content exceeds 50%, the reaction rate of the polycarbonate increases, but undesirable linear low polymers are mixed in the obtained aromatic cyclic carbonate, and the polymerization activity becomes poor, and Further, the quality of the polycarbonate produced from the mixture of the aromatic cyclic carbonates, especially the color tone, heat deterioration resistance, and hydrolysis resistance, is poor.

If the OH concentration is too high beyond the above range, the inventors have previously proposed US Pat.
The method of treating with a specific salicylate as described in JP-A-96,222 is effective. According to the method, the target OH group concentration can be easily adjusted.

When the OH group concentration is lower than 5 mol%, aromatic dihydroxy compounds such as 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 9-
Bisphenols such as bis (4-hydroxyphenyl) fluorene, and dihydroxy compounds such as hydroquinone and 4,4'-dihydroxydiphenyl can be preferably melt-reacted in the presence or absence of a transesterification catalyst.

In a further preferred embodiment of the present invention,
The solvent used in the first step is preferably a polycarbonate-soluble solvent composed of at least one selected from the following solvent group. That is, the solvent group does not contain active hydrogen of ether compounds, thioether compounds, ketone compounds, sulfo compounds, sulfoxide compounds, and amide compounds, a normal pressure boiling point of 300 ° C. or less, and a water content of 2
Those having 0 ppm or less and the dissolved oxygen content of 10 ppm or less are preferably selected.

Specific examples of such a solvent include ether compounds such as thiophene, dioxane, tetrahydrofuran, anisole, and diphenyl ether;
Examples thereof include thioether compounds, ketone compounds such as acetophenone, cyclohexanone, and acetone, and amide compounds such as N, N-dimethylformamide and N, N-dimethylacetamide. Among these, dioxane and tetrahydrofuran are exemplified as preferred.

In order to use these solvents as reaction solvents, it is preferable to reduce the amount of water and dissolved oxygen in the solvent. The lower the water content, the better
0 ppm or less, more preferably 10 ppm or less.

In order to reduce the amount of water in the solvent to the above-mentioned amount, there is a method using a so-called dehydrating agent, for example, a metal hydride such as calcium hydride or lithium borohydride. However, a method using a water adsorbent, in particular, a molecular sieve. The method is preferable because the yield of the mixture of aromatic cyclic carbonates can be suitably increased.

Further, reducing the amount of dissolved oxygen in the solvent increases the polymerization activity of the resulting aromatic cyclic carbonate mixture, and further enhances the color tone of the polycarbonate obtained by polymerizing the aromatic cyclic carbonate mixture. It is preferable for improving the hydrolysis resistance. In order to reduce the dissolved oxygen concentration to 10 ppm, a normal degassing process may be followed. More preferably, the dissolved oxygen concentration is 5 ppm or less.

More preferably, the amount of the alkali metal catalyst used in the first step is 1 × 10 ^-6 to 1 × 10 ^-1 equivalent per 1 mol of the repeating unit represented by the above formula (1). Is preferred. Preferably 1 × 10 ^{−6 to} 5 ×
10 ^-2 equivalents, more preferably 5 × 10 ^-6 to 1 × 10 ^-2
It is characterized as equivalent. If the amount of catalyst is too small,
In some cases, the effect of the addition is ineffective, and when too much, the cyclic carbonate may be decomposed.

Examples of the metal element of the alkali metal catalyst used in the present invention include lithium, sodium, potassium, cesium, and rubidium. Among them, sodium, sodium and potassium are preferable in terms of reaction rate and yield.
Potassium and cesium are selected.

The hydrides, hydrocarbon compounds, borohydride compounds, aluminum hydride compounds, art complexes, oxides, hydroxides, alcoholates, phenolates, bisphenol salts, and 1,3-diketo complexes of these elements are preferably used. You. It is preferable that these alkali metal compounds have no water content.

Specifically, for example, hydrides such as sodium hydride, potassium hydride, rubidium hydride and cesium hydride, hydrocarbon compounds such as sodium naphthalene, potassium naphthalene, butyl lithium, benzyl potassium, benzyl cesium and indenyl cesium, sodium borohydride Borohydride compounds such as hydride, potassium borohydride, cesium borohydride, sodium aluminum hydride, potassium aluminum hydride, and cesium aluminum hydride; aluminum hydride compounds; art complexes such as sodium tetraphenylborate, potassium tetraphenylborate, and cesium tetraphenylborate; Sodium oxide, potassium oxide, cesium oxide, rubidium oxide, sodium hydroxide, potassium hydroxide, Cesium oxide, oxides such as rubidium hydroxide, hydroxides, sodium methylate, potassium t- butoxide, cesium propoxide, cesium t- butoxide, rubidium ethylate, sodium phenolate, potassium phenolate, cesium 2,4
Bisphenol salts such as di-t-butylphenolate, bisphenol A monosodium salt, bisphenol A disodium salt, bisphenol A dipotassium salt, bisphenol A monocesium salt, bisphenol A disesium salt, and sodium acetylacetonate, potassium acetylacetonate; Examples thereof include 1,3-diketo complexes such as rubidium acetylacetonate and cesium acetylacetonate.

The reaction conditions in the presence of a catalyst include a reaction temperature of room temperature to 120 ° C., preferably 30 to 110 ° C., and more preferably 30 to 100 ° C. The reaction proceeds even when the reaction temperature is lower than this. The lower the reaction temperature is, the higher the reaction selectivity is, and preferably, the higher the reaction temperature is, the more preferable. However, when the reaction temperature is increased, the reaction selectivity may decrease. The above reaction temperature is preferably selected from the viewpoint of the reaction selectivity and the reaction rate.

The reaction time is selected from the range of 10 minutes to 5 hours. The reaction time is appropriately selected from the above range in consideration of the reaction conversion of the polycarbonate.

At the stage where the first step is completed, or at the stage where the poor solvent solution of the polycarbonate containing the aromatic cyclic carbonate mixture is obtained in the second stage, the alkali metal catalyst is deactivated by the catalyst. It is preferably treated with an agent. As the catalyst deactivator, carboxylic acid, phosphoric acid, acidic or neutral phosphate, phosphorous acid,
Examples thereof include acidic or neutral phosphites, sulfonic acids, sulfonic esters, ammonium sulfonates, and phosphonium sulfonates.

The amount of the catalyst deactivator added is 0.8 to 20 per equivalent of the alkali metal element of the alkali metal catalyst.
The equivalent is preferably in the range of 0.9 to 10 equivalents, more preferably 0.9 to 5 equivalents, particularly preferably 0.95 to 2 equivalents.

In terms of stoichiometry, one equivalent of the catalyst deactivator should be sufficient for one equivalent of the alkali catalyst, but the degree of deactivation is high and low, and the amount is adjusted accordingly.

When the acid itself is added, basically, one equivalent is added. If the amount is too large, the cyclic carbonate is decomposed, which is not preferable. On the other hand, in the case of esters, ammonium sulfonates and phosphonium sulfonates, since such adverse effects are small, they may be added in large amounts.

Examples of these catalyst deactivators include: a) lower carboxylic acids such as formic acid, acetic acid, butyric acid, oxalic acid, succinic acid, adipic acid, benzoic acid, and terephthalic acid; i) phosphoric acid, trimethyl phosphate, dibutyl phosphate, monooctyl phosphate; , Triphenyl phosphate, bis (2,4-di-t-phosphate)
-Butylphenyl), phosphoric acid such as tris (2,6-t-butyl-4-methylphenyl) and dioctylpentaerythrityldiphosphate, and lower acidic and neutral ester derivatives thereof c) phosphorous acid, tributyl phosphite , Dinonyl phosphite, monodecyl phosphite, triphenyl phosphite, bisphosphite (2,
4-di-t-butylphenyl), tris phosphite (2,6-
t-butyl-4-methylphenyl), bis (2,6-t
-Butyl-4-methylphenyl) pentaphosphorous acid such as pentaerythrityl diphosphite and lower acidic and neutral ester derivatives thereof e) Benzenesulfonic acid, p-toluenesulfonic acid, nonylsulfonic acid, methanesulfonic acid, benzenesulfonic acid Sulfonic acids such as methyl acrylate, butyl p-toluenesulfonate, octyl nonylsulfonate, and dodecyl methanesulfonate; lower esters of sulfonic acids; o) benzenesulfonic acid tetramethylammonium salt;
Examples thereof include p-toluenesulfonic acid tetramethylphosphonium salt, nonylsulfonic acid tetraethylammonium salt, dodecylsulfonic acid tetrabutylphosphonium salt, dodecylbenzenetetrabutylphosphonium salt, and dodecylbenzenesulfonic acid tetramethylammonium salt. You.

In the second step described above, a non-solvent of water-insoluble polycarbonate is added to the reaction solution containing the mixture of aromatic cyclic carbonates produced in the first step. The aromatic cyclic carbonate mixture can be produced by removing the solvent of the reaction solution containing the cyclic carbonate mixture obtained by separating the insoluble matter in a specific temperature range, that is, 150 ° C. or lower.

In Japanese Patent Publication No. 41-14595, the aromatic cyclic carbonate itself is a sufficiently stable compound in a pure form, but it can be very easily heated to 200 ° C. in the presence of a minute amount of a hydroxyl compound. Describes a ring-opening polymerization reaction.

In the step of removing the solvent and the solvent of the present invention, it is naturally impossible to raise the temperature to 200 ° C., but it is preferable that the temperature should not exceed 150 ° C. When the temperature exceeds 150 ° C., the polymerization initiator such as a small amount of a hydroxy compound contained in the reaction solution causes a ring-opening reaction of aromatic cyclic carbonates or other side reactions, and the yield of aromatic cyclic carbonates Decrease. Therefore, the temperature of the solvent removal is preferably 140 ° C. or less, more preferably 130 ° C.
It must be kept below.

Further, the mixture of aromatic cyclic carbonates of the present invention is: a) Less than 2.5 × 10 ^-2 equivalents of phenolic OH end groups per mole of carbonate structural unit, as impurities; a) Hydrolysis C) The content of the alkali (earth) metal compound is 2 ppm or less as an element, respectively. D) The phosphorus compound content is 3 ppm or less as a phosphorus element. E) Other than the alkali (earth) metal. The mixture is characterized in that the metal compound has an element content of 1 ppm or less, respectively, and the nonmetal compound other than phosphorus and halogen has an element content of 2 ppm or less.

According to such a molecular structure, the phenolic OH terminal group concentration per mole of the carbonate structural unit is 2.5%.
When the molecular weight is less than × 10 ^-2 , the activity in the polymerization reaction is increased, and the molecular weight of the polycarbonate resin obtained from the aromatic cyclic carbonate mixture becomes high.

Further, when the content of the phenolic OH terminal group is within the above range, the stability of the aromatic cyclic carbonate mixture during storage can be improved. That is, coloring of the agent during storage for a long period of time can be prevented. From the colored agent, it is difficult to obtain the original transparent resin of polycarbonate, and the economic value of the agent and the resin is reduced.

The smaller the amount of phenolic OH terminal groups per mole of carbonate structural unit, the more preferable in the above sense. However, if the amount of phenolic OH terminal groups per mole of carbonate structural unit is less than 2.5 × 10 ^-2 equivalent, it is within the permissible range. However, preferably 1.0 × 10
^It is less than ⁻² equivalents, more preferably less than 5 × 10 ⁻³ equivalents, particularly preferably less than 1.0 × 10 ⁻³ equivalents.

In addition to the phenolic OH termini, impurities also have a significant effect on the reactivity of the aromatic cyclic carbonate mixture, ie the rate of polymerization, and the degree of polymerization of the polymerized polycarbonate. In addition, the impurity levels have a significant adverse effect on the hue, transparency and stability of the resulting polycarbonate, ie its resistance to heat degradation and hydrolysis.

That is, hydrolyzable halogens, especially chlorine, and heavy metal elements, in particular, Fe, Cr, Ni, n, and Ti, have a stronger yellow tint and a commercial value than the hue of polycarbonate, which is inherently colorless and transparent. Lower it,
When kept at a high temperature for a long period of time, it deteriorates a colorless and transparent hue, causing an increase in yellowish color and a decrease in molecular weight. A decrease in the molecular weight naturally results in a decrease in mechanical properties such as impact resistance, breaking strength, and breaking elongation of the molded article kept at a high temperature for a long time.

The above impurities and elemental phosphorus lower the polymerization activity of the obtained aromatic cyclic carbonate. That is, there are cases where the time required to increase the molecular weight to the predetermined molecular weight becomes longer or the molecular weight does not increase to the predetermined molecular weight.

The above impurity level is considered in consideration of the quality and stability of the aromatic cyclic carbonate, the level which does not impair the colorless and transparent properties of the polycarbonate resin obtained from the aromatic cyclic carbonate, and the acceptable level of mechanical property stability. Is exemplified.

In order to make full use of the colorless transparency and mechanical properties which are the original characteristics of the polycarbonate resin,
The mixture of aromatic cyclic carbonates is preferably a) having a total content of hydrolyzable halogen elements of 0.5 pp
m) a) The content of alkali (earth) metal compound is 1.0 ppm or less as an element. c) The phosphorus compound content is 2 ppm or less as a phosphorus element. d) The content of metal compound other than alkali (earth) metal is element. The content of non-metallic element-containing compounds other than phosphorus and halogen is at a level of 1 ppm or less, respectively. More preferably, a) the total content of hydrolyzable halogen elements is 0.5 pp
m) a) Alkaline (earth) metal compound content is 0.8 ppm or less as an element, respectively c) Phosphorus compound content is 1 ppm or less as a phosphorus element d) Content of nonmetallic element-containing compounds other than phosphorus and halogen is an element And the content of metal compounds other than the alkali (earth) metal is 0.1 or less, respectively.

As a method for obtaining an aromatic cyclic carbonate mixture satisfying such molecular structural characteristics and impurity levels, there are methods for satisfying molecular structural parameters and impurity parameters of an aromatic polycarbonate as a starting material, and a solvent, a catalyst, It is necessary to satisfy the reaction conditions.

As a method for obtaining a mixture of aromatic cyclic carbonates satisfying even more preferable molecular structural characteristics and impurity levels, an aromatic cyclic carbonate solution is prepared by:
Activated carbon treatment, OH type strong basic ion exchange resin treatment and H
It can be achieved by combining and using a strong acid ion exchange resin treatment of the type. This treatment can reduce the preferred molecular structural features and impurity levels to a satisfactory level in a single treatment, but can be performed two or more times to achieve even lower impurity levels.

By such a treatment, the content of the hydrolyzable halogen, the content of the alkali (earth) metal element, the metal compound, and the nonmetal compound element can be easily reduced to 0.5 ppm or 0.1 ppm.
It can be 1 ppm or less. Even if the number of processes is increased to three or more, the effect of the repetition is not significant.

At this time, it is not necessary to prepare the aromatic cyclic carbonate solution by specially dissolving the aromatic cyclic carbonate, and the solution containing the cyclic carbonate mixture prepared in the first step or the second step is used. The solution of the cyclic carbonate mixture prepared in the above was directly treated with activated carbon and
It can be easily and effectively obtained by treating with an H-type strongly basic ion exchange resin and an H-type strongly acidic ion exchange resin. The activated carbon used in the present invention does not have to be special. In order to exhibit the treatment effect, it is preferable that the activated carbon has a large specific surface area of 300 m ² / g or more. More preferably, it is 500 m ² / g or more.

As the ion exchange resin, a commercially available ion exchange resin can be treated sufficiently efficiently. The order of such processing is as follows:
The ion exchange resin treatment is performed first, and then the activated carbon treatment is performed. Either of the OH-type strongly basic ion exchange resin treatment and the H-type strongly acidic ion exchange resin treatment may be performed first.

The type of the reaction may be any type such as a batch type, a semi-batch type, a flow type, a complete mixing tank, or a tubular reactor.

The cyclic polycarbonate mixture of the present invention can be heated and melt-polymerized without substantially adding a catalyst.
However, to make the polymerization process more efficient, it is used in the production of melt-polymerized polycarbonate,
By heating to 200 ° C. or higher in the presence of a conventionally known transesterification catalyst, ring-opening polymerization is easily carried out to produce a linear polycarbonate having good hue and stability.

Among them, preferred examples of the catalyst include 1) a basic nitrogen compound or a basic phosphorus compound and / or 2) an alkali metal compound or an alkaline earth metal compound.

Among these, specific examples of the nitrogen-containing basic compound include, for example, tetramethylammonium hydroxide (Me ₄ NOH), tetraethylammonium hydroxide (Et ₄ NOH), benzyltrimethylammonium hydroxide (φ-CH ₂ (Me) ₃ NOH) and other ammonium hydroxides having an alkyl, aryl, alkylaryl group or the like in the molecule; tetramethylammonium acetate, tetraethylammonium phenoxide, tetrabutylammonium carbonate, benzyltrimethylammonium benzoate, hexa Basic ammonium salts having an alkyl, aryl, alkylaryl group or the like such as decyltrimethylammonium ethoxide; tertiary amines such as triethylamine or dimethylbenzylamine; Or, tetramethylammonium borohydride (Me ₄ NBH _4), and tetramethylammonium tetraphenylborate (Me ₄ NBP
It can be mentioned basic salts h ₄₎ and the like.

As specific examples of the phosphorus-containing basic compound,
Is, for example, tetramethylphosphonium hydroxide
(Me_FourPOH), hexadecyltrimethylphosphonium
Alkyl, aryl, alkyl ant such as
Phosphonium hydroxides having a hydroxyl group or the like; or
Is tetramethylphosphonium borohydride (Me_Four
PBH_Four), Tetrabutylphosphonium tetraphenyl
Borate (Bu_FourPBPh _Four), And tetramethylphos
Phonium tetraphenylborate (Me_FourPBPh _Four)etc
And the basic salts of

The above-mentioned nitrogen-containing basic compound and / or phosphorus-containing basic compound can be obtained by bonding a basic nitrogen atom or a basic phosphorus atom to a carbonate bond of a starting aromatic cyclic carbonate.
It is preferably used in a ratio of 1 × 10 ^{−5 to} 5 × 10 ⁻⁴ chemical equivalents, more preferably a ratio of 2 × 10 ^{−5 to} 5 × 10 ⁻⁴ chemical equivalents with respect to the same standard. It is particularly preferably used at a ratio of 5 × 10 ^{−5 to} 5 × 10 ⁻⁴ chemical equivalents with respect to the same standard.

On the other hand, an alkali (earth) metal compound used as a polymerization catalyst is an alkali (earth) metal per 1 mol of carbonate bonds of a raw material aromatic cyclic carbonate.
The metal element is used in the range of 5 × 10 ⁻⁸ to 1 × 10 ⁻⁶ chemical equivalent. By using such an amount of catalyst,
Undesirable phenomena such as branching reactions, main chain cleavage reactions, and the generation of foreign substances and burning in the equipment during molding that can be carried out without impairing the polycondensation reaction rate and are easily generated during the polycondensation reaction. This is preferable because it can be effectively suppressed and a good quality linear polycarbonate can be produced.

Examples of the alkali (earth) metal compound used as a polymerization catalyst include alkali (earth) metal hydroxides, hydrocarbon compounds, carbonates, acetates, nitrates, and nitrites. , Sulfites, cyanates, thiocyanates, stearates, borohydrides, benzoate phosphides, bisphenols, phenol salts, and the like. Specific examples include sodium hydroxide, hydroxide Lithium, barium hydride, lithium bicarbonate, potassium carbonate, sodium acetate, lithium acetate, calcium acetate, rubidium nitrate, sodium nitrite, potassium sulfite, sodium cyanate, potassium cyanate, sodium thiocyanate, potassium thiocyanate, stearic acid Sodium, cesium stearate, calcium stearate, hydrogenated Sodium c arsenide, lithium borohydride, sodium phenyl borohydride, lithium benzoate, sodium hydrogen phosphate di- hydrogen phosphate dipotassium,
Disodium salt, dipotassium salt, dilithium salt, monosodium salt, monopotassium salt, sodium potassium salt and bisphenol A sodium salt of bisphenol A;
And potassium salts.

The polymer having excellent durability and stability of the present invention can be obtained by the above-mentioned method. In the case of molding various molded articles using the polymer, conventionally known processing stabilizers and
Heat stabilizers, antioxidants, ultraviolet absorbers, antistatic agents,
You may add a flame retardant, a release agent, etc.

Further, a heat stabilizer can be blended in order to prevent a decrease in the molecular weight and a deterioration in hue of the aromatic polycarbonate of the present invention. Examples of such a heat stabilizer include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid and esters thereof, and trisnonylphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite , 4,4′-biphenylenediphosphosphinic acid tetrakis (2,4-di-tert-butylphenyl), trimethyl phosphate, and dimethyl benzenephosphonate are preferably used. These heat stabilizers may be used alone or in combination of two or more. The amount of the heat stabilizer is preferably 0.0001 to 1 part by weight, more preferably 0.0005 to 0.5 part by weight, more preferably 0.001 to 0.5 part by weight, per 100 parts by weight of the aromatic polycarbonate of the present invention. One part by weight is more preferred.

Further, in order to further improve the releasability from the mold at the time of melt molding, a releasing agent can be added to the aromatic polycarbonate of the present invention as long as the object of the present invention is not impaired. is there. Examples of the release agent include an olefin wax, an olefin wax containing a carboxyl group and / or a carboxylic anhydride group, silicone oil, an organopolysiloxane, a higher fatty acid ester of a monohydric or polyhydric alcohol, paraffin wax, and Beeswax and the like. The amount of the release agent is 0.00.0 parts by weight based on 100 parts by weight of the aromatic polycarbonate of the present invention.
1 to 5 parts by weight is preferred.

The higher fatty acid esters include monohydric or polyhydric alcohols having 1 to 20 carbon atoms and 10 to 20 carbon atoms.
It is preferably a partial ester or a total ester with 30 saturated fatty acids. As such a partial ester or a whole ester of a monohydric or polyhydric alcohol and a saturated fatty acid, stearic acid monoglyceride, stearic acid triglyceride, and pentaerythritol tetrastearate are preferably used. The amount of the release agent is 0.01 to 5 parts by weight based on 100 parts by weight of the aromatic polycarbonate of the present invention.
Parts by weight are preferred.

Further, inorganic and organic fillers can be blended with the aromatic polycarbonate of the present invention in order to improve rigidity and the like as long as the object of the present invention is not impaired. Examples of such inorganic fillers include talc, mica, glass flakes, glass beads, calcium carbonate, titanium oxide and other plate-like or granular inorganic fillers and glass fibers, glass milled fibers, wollastonite, carbon fibers,
Examples include fibrous fillers such as aramid fibers and metal-based conductive fibers, and organic particles such as crosslinked acrylic particles and crosslinked silicone particles. The compounding amount of these inorganic and organic fillers is preferably from 1 to 150 parts by weight, more preferably from 3 to 100 parts by weight, based on 100 parts by weight of the aromatic polycarbonate of the present invention.

The inorganic filler usable in the present invention may be surface-treated with a silane coupling agent or the like. By this surface treatment, good results such as suppression of decomposition of the aromatic polycarbonate can be obtained.

Other resins can be added to the aromatic polycarbonate of the present invention as long as the object of the present invention is not impaired.

As such other resins, for example, polyamide resins, polyimide resins, polyetherimide resins,
Polyurethane resin, polyphenylene ether resin, polyphenylene sulfide resin, polysulfone resin, polyolefin resin such as polyethylene and polypropylene, polyester resin such as polyethylene terephthalate and polybutylene terephthalate, amorphous polyarylate resin, polystyrene resin, acrylonitrile / styrene copolymer ( AS resin), acrylonitrile / butadiene / styrene copolymer (ABS resin), polymethacrylate resin,
Resins such as phenolic resins and epoxy resins are exemplified.

A molded article having good durability and stability can be obtained from the polycarbonate produced by the present invention by an injection molding method or the like.

The aromatic polycarbonate of the present invention has an effect of maintaining the durability of the polymer, particularly for a long time under severe temperature and humidity conditions, by suppressing the above-mentioned specific impurities to a specific value or less. Compact disk (CD), CD-ROM, CD-ROM obtained using the polymer
Digital versatile discs (DVD-R, CD-RW, etc.), magnet optical discs (MO), etc.
ROM, DVD-Video, DVD-Audio, D
A substrate for a high-density optical disk typified by VD-R, DVD-RAM, etc. can provide high reliability over a long period of time.
In particular, it is useful for a high-density optical disk such as a digital versatile disk.

The sheet made of the aromatic polycarbonate resin produced by the present invention is an aromatic polycarbonate sheet having excellent adhesiveness and printability, and is widely used for electric parts, building material parts, automobile parts, etc. by utilizing its properties. More specifically, glazing products for window materials such as various types of window materials, such as general houses, gymnasiums, baseball domes, vehicles (construction machines, automobiles, buses, bullet trains, train cars, etc.), and various side walls (sky dome, top) Lights, arcades, apartment lumbar boards,
Roadside walls), window materials for vehicles, etc., displays and touch panels for OA equipment, membrane switches, photo covers, polycarbonate resin laminates for water tanks, front panels for projection televisions and plasma displays, Fresnel lenses, optical cards, optical disks, etc. It is useful for optical applications such as a liquid crystal cell and a phase difference correction plate in combination with a polarizing plate. The thickness of the aromatic polycarbonate sheet is not particularly limited, but is usually 0.1 to 10 mm, preferably 0.2 to 8 mm, and particularly preferably 0.2 to 3 mm. In addition, various processings (various lamination processing for improving weather resistance, abrasion resistance improvement processing for improving surface hardness, surface graining, semi- and opaque processing) for adding new functions to the aromatic polycarbonate sheet. Processing).

Any method may be employed for blending additives with the aromatic polycarbonate resin of the present invention. For example, a method of mixing with a tumbler, a V-type blender, a super mixer, a Nauta mixer, a Banbury mixer, a kneading roll, an extruder or the like is appropriately used. The aromatic polycarbonate resin composition thus obtained is pelletized as it is or by a melt extruder, and then formed into a sheet by a melt extrusion method.

The polycarbonate of the present invention can be produced by mixing the above-mentioned components by any method, for example, using a tumbler, a blender, a Nauter mixer, a Banbury mixer, a kneading roll, or an extruder.

A molded article having good durability and stability can be obtained from the polycarbonate produced by the present invention by an injection molding method or the like.

The polycarbonate produced in the present invention may be used for any purpose, and is particularly preferably used as an optical disk substrate material.

[0094]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to the examples.

[Production of Raw Polycarbonate] The following 12 types of raw polycarbonate were used. Tables 1 and 2 show the respective physical properties.

PC-1: Commercially available general-purpose polycarbonate manufactured by Teijin Chemicals Limited L1250 was dried at 120 ° C. × 12 hr × 13 Pa in a vacuum dryer.

PC-3: PC-1 was dissolved in a 20-fold amount of reagent-grade tetrahydrofuran, treated with a Na-type strong ion-exchange resin, and then high-purity methanol for electronics was added to precipitate polycarbonate. The precipitated polycarbonate was washed with methanol and air-dried.

PC-2: PC-3 was placed in a vacuum dryer at 12
It was dried at 0 ° C. × 12 hr × 13 Pa.

PC-4: The same treatment of washing and drying was again applied to PC-2.

PC-5: Bisphenol A mono (t-butylphenyl carbonate) was melt-added to PC-2 in a ruder to adjust the phenolic OH concentration.

PC-6, PC-7: In a reactor equipped with a stirrer, a rectification column and a decompression device, 137 parts by weight of purified bisphenol A, 135 parts by weight of purified diphenyl carbonate, and 135 parts by weight of a polymerization catalyst were used. 0.81 × 10 ⁻⁴ parts by weight of bisphenol A disodium salt and 15 × 10 ⁻³ parts by weight of tetramethylammonium hydroxide were added and dissolved at 150 ° C. under a nitrogen atmosphere. The temperature was raised to 180 ° C. while stirring, and the inside of the reaction vessel was 133 × 10 ² P
The pressure was reduced to a, and the reaction was carried out for 20 minutes while distilling off the generated phenol. Next, after the temperature was raised to 200 ° C., the pressure was gradually reduced, and the pressure was reduced to 40 × 10 ² Pa while distilling off phenol.
The reaction was performed for 0 minutes. Then gradually raise the temperature to 220 ° C for 20
Reaction at 240 ° C for 20 minutes, then 270 ° C
And gradually reduce the pressure to 27 × 10 ² Pa for 10 minutes, 13 × 1
The reaction was continued at 0 ² Pa for 5 minutes.
The reaction was continued at 0.6 × 10 ² Pa until a predetermined molecular weight was reached. The obtained polycarbonate was dried (P
C-6) and those not dried (water content 0.25)
wt%, PC-7) was obtained.

PC-8, 9: Polycarbonate produced by PC-6, O-methoxycarbonylphenylphenyl carbonate per 100 parts by weight of 2.75, respectively.
And 0.97 parts by weight at 280 ° C., 10 minutes, 13 Pa
A mixed reaction was performed under the conditions.

PC-10, 11; 0.03 each per 100 parts by weight of the polycarbonate obtained by PC-8
2, and 0.10 parts by weight of tris (2,4-di-tert-butylphenyl) phosphite were melt added.

PC-12: In PC-6, diphenyl carbonate was changed to 141 parts by weight and bisphenol A disodium salt was changed to 8.1 × 10 ^-4 parts by weight, and finally the reaction temperature was 290 ° C. , The degree of vacuum is 2.7 × 1
The reaction was continued at 0 ² Pa until the predetermined molecular weight was obtained.

[Production of Aromatic Cyclic Carbonate Mixtures Examples 1 to 7, Comparative Examples 1 to 8] PC1 to PC12
Are dissolved in 100 parts by weight of a predetermined amount of THF dried with a molecular sieve and deoxygenated with nitrogen gas, and a predetermined amount of cesium butoxide is added as shown in Tables 3 and 4. 5 hours at 40 ° C under air current
r reaction was performed. After the reaction, the mixture was neutralized with an equivalent amount of acetic acid, 300 parts by weight of hexane was added, the precipitate was centrifuged, and the supernatant was separated. The hexane solution was washed with 100 parts by weight of pure water, and the lower water tank was removed by a centrifugal separator. After repeating this operation 5 times, the solvent was removed at a temperature of 40 ° C. or lower, and then 1
Under a high vacuum of × 10 ² Pa or less, the solvent and water were completely removed. Tables 3 and 4 show the yield and yield of the obtained aromatic cyclic carbonate mixture.

[Purification of a mixture of aromatic cyclic carbonates]
One part by weight of the obtained mixture of aromatic cyclic carbonates was dissolved in 100 parts by weight of chloroform and washed three times with pure water. Thereafter, 1 part by weight of activated carbon was added, and the mixture was stirred at room temperature for 10 hr. After the activated carbon was separated by filtration, the solvent was removed with an evaporator. The obtained purified cyclic carbonate mixture was dried under a high vacuum of 10 Pa or less at room temperature. Tables 5 and 6 show those that have undergone the purification treatment and those that have not.
Each physical property was shown.

[Polycarbonate polymerization from a mixture of aromatic cyclic carbonates: Examples 8 to 14, Comparative Examples 9 to 2]
3] A mixture of aromatic cyclic carbonates which has been purified or not purified as shown in Tables 5 and 6, and a mixture of various aromatic cyclic carbonates containing various metals as shown in Table 7; 254 parts by weight Was mixed with 1.2 × 10 ⁻⁴ parts by weight of sodium phenoxide in a container made of SUS316 at 290 ° C. for 20 minutes. After the reaction, 8.2 × 10 ^-4 parts by weight of tetrabutylphosphonium benzenesulfonate was added. Table 5 shows the physical properties of the obtained polycarbonate.
It is described in 6 and 7.

[Analysis] The physical properties of the raw material polycarbonate, the obtained mixture of cyclic carbonates, and the polycarbonate were measured as follows.

1) Method for measuring number-average molecular weight and weight-average molecular weight 3 mg of a sample was dissolved in 3 ml of chloroform, and the pore size was measured at 0.
Filtered through a 45 μm hydrophilic PTFE Millipore filter,
It was measured by gel permeation chromatography. For molecular weight calibration, use monodisperse polystyrene (EasiC
al; manufactured by Polymer Laboratory Co., Ltd.). GPC measurement conditions Column; PLgel 5μ MIXD-D (300 × 7.
Mobile phase manufactured by Polymer Laboratory; chloroform Flow rate: 1.0 ml / nim detection; detected at 254 nm wavelength by 481 UV-visible detector (manufactured by Nippon Waters KK).

2) Measurement of dissolved oxygen concentration in solvent: DO meter for organic solvent, manufactured by Central Chemical Co., Ltd .;
Measured by C-12-SOL.

3) Determination of Metal Element and Nonmetal Element About 2 g of a sample was precisely weighed and placed in a quartz crucible, and incinerated in a burner and then in an electric furnace. Treating the ash with concentrated nitric acid,
After overheating and dissolving with dilute nitric acid, the mixture was dissolved by heating with dilute nitric acid and quantified. The quantification of the alkali metal element was carried out by flame atomic absorption spectrometry (manufactured by Hitachi, Ltd .; polarized Zeeman-type atomic absorption spectrometer Z).
5700). Nonmetal elements including metals and phosphorus were quantified by ICP mass spectrometry (SPQ6500, manufactured by Seiko Instruments Inc.).

4) Halogen amount: The sample was burned in an argon / oxygen stream, and the generated halogen or hydrogen was titrated with a Dorman microtitrator, MCTS-120, manufactured by Dorman Co., Ltd., and the halogen amount was determined from the amount of electricity required for titration. .

5) Determination of the amount of active halogen; about 5 g of sample
Was dissolved in 50 ml of toluene, and the eluent (2.8 mM Na
HCO3 / 2.25 mM Na2CO3 = 1: 1) 10 m
After adding l, 40 ml of pure water was added, and the mixture was stirred and extracted. The amount of chlorine in the extracted solution was quantified by ion chromatography 2000i manufactured by Dionex.

6) Melt viscosity stability; manufactured by Rheometrics Co .; using a RAA type flow analyzer, the absolute value of the change in melt viscosity measured at a shear rate of 1 rad / sec at 300 ° C. under a nitrogen gas flow for 30 minutes was measured. The rate of change per minute was determined. This value should not exceed 1% for good long-term stability of the polycarbonate resin. Preferably it is 0.5%, particularly preferably 0%.

7) Quantification of OH group concentration: 0.02 g of a sample was dissolved in 0.4 ml of deuterated chloroform and measured at 20 ° C. using 1 H-NMR (EX-270 manufactured by JEOL Ltd.).

8) Heat resistance (5% weight loss temperature): ° C Measured by TG-DSC under a nitrogen stream. This value of polycarbonate from bisphenol by an interfacial polymerization method or a transesterification method was 485 ° C. Those showing a value lower than 480 ° C are those in which the inherent stability of polycarbonate is not realized due to impurities or other reasons, and NG
Is determined.

9) Degree of polymerization of polycarbonate Intrinsic viscosity [η] was measured with an Ubbelohde viscosity tube in methylene chloride.
Was measured, and the viscosity average molecular weight; Mv was determined by the following equation. [Η] = 1.23 × 10 ⁻⁴ Mv ^0.83

10) Hazen Aromatic cyclic carbonate was used to measure the diameter of 23 mm and the thickness of 1.5 based on the color number test method specified in JIS K4101.
mm, flat bottom Pyrex glass colorimetric tube, liquid depth 1
The sample was held in a molten state at 40 mm and 170 ° C. for 1 hour under a nitrogen stream, and measured in comparison with a Hazen standard colorimetric liquid.

[0119]

[Table 1]

[0120]

[Table 2]

[0121]

[Table 3]

[0122]

[Table 4]

[0123]

[Table 5]

[0124]

[Table 6]

[0125]

[Table 7]

[0126]

According to the present invention, it is possible to produce 2) a mixture of aromatic cyclic carbonates having good reactivity 1) with good yield from aromatic polycarbonate resin. Further, an aromatic polycarbonate resin having 3) good reactivity and 4) good color tone, heat deterioration resistance and hydrolysis resistance can be obtained from the aromatic cyclic carbonate mixture produced by the method.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuichi Kageyama 2-1 Hinode-cho, Iwakuni-shi, Yamaguchi Prefecture Teijin Co., Ltd. Inside the Iwakuni Research Center (72) Inventor Katsuji Sasaki 2-1 Hinode-cho, Iwakuni-shi, Yamaguchi Prefecture Teijin Shares A term in the Iwakuni Research Center of the company (reference)

Claims (9)

[Claims] 1. A mixture of aromatic cyclic carbonates having a main repeating unit represented by the following formula (1): (Wherein, R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or 6 to 10 carbon atoms. W is an alkylidene group having 2 to 10 carbon atoms, an alkylene group having 1 to 10 carbon atoms, a cycloalkylidene group having 6 to 10 carbon atoms, a cycloalkylene group having 6 to 10 carbon atoms, 10 to 10 arylene groups, 1 to 1 carbon atoms
An alkylene group, an oxygen atom, a sulfur atom, a sulfoxide group or a sulfone group, which may have 0 substituents, or a direct bond. In the production from the aromatic polycarbonate represented by the formula (1), the production method comprises reacting the aromatic polycarbonate in a solvent in the presence of an alkali metal compound catalyst to produce a reaction solution containing a mixture of aromatic cyclic carbonates. And a second step of separating an aromatic cyclic carbonate mixture from the reaction solution,
A method for producing a mixture of aromatic cyclic carbonates, wherein the aromatic polycarbonate in the first step satisfies the following 1) to 4). 1) The viscosity average molecular weight is 10,000 to 60,000, and Mn; the number average molecular weight in terms of polystyrene, and Mw; the ratio of the weight average molecular weight in terms of polystyrene, Mw / Mn, is 2.0 to 3.0, 2). A phosphorus compound content of not more than 30 ppm as a phosphorus element; 3) a water content of not more than 0.01 wt%; 4) the polycarbonate terminal group substantially comprises an aryloxy group and a phenolic OH group; The content is 5 to 50 mol% of all terminal groups. 2. A non-metallic compound other than phosphorus and halogen, wherein the content of a metal compound other than an alkali metal element, an alkaline earth metal element and an alkali (earth) metal in the aromatic polycarbonate is 2 ppm or less, respectively. 2. The method for producing an aromatic cyclic carbonate mixture according to claim 1, wherein the content of each element is 3 ppm or less as an element, and the content of a halogen compound is 30 ppm or less as a total amount of the halogen elements. 3. In a second step, a poor solvent of water-insoluble polycarbonate is added to the reaction solution prepared in the first step, and then the insoluble precipitate is separated.
The method for producing an aromatic cyclic carbonate mixture according to any one of claims 1 and 2, comprising a step of removing a solvent from the reaction solution at a temperature of not more than ° C. 4. A mixture of aromatic cyclic carbonates comprising: a) phenolic O per mole of carbonate structural unit
H terminal group is 2.5 × 10 ^-2Less than the equivalent, a) the total content of hydrolyzable halogen elements is 2 ppm or less
Bottom, c) Content of alkali (earth) metal compound as element
D) The content of the phosphorus compound is 3 ppm or less as a phosphorus element.
Below, e) The content of metal compounds other than alkali (earth) metals
Each element is 1 ppm or less, and phosphorus and
Content of compounds containing nonmetallic elements other than
Each of which is not more than 2 ppm
Aromatic cyclic carbonate mixtures. 5. The aromatic cyclic carbonate mixture according to claim 4, wherein the aromatic cyclic carbonate mixture is produced by the method according to claim 1. 6. A linear polycarbonate obtained by subjecting the aromatic cyclic carbonate mixture according to claim 4 to melt heat polymerization. 7. A linear polycarbonate, wherein the melt heat polymerization according to claim 6 is carried out in the presence of a transesterification catalyst. 8. The transesterification catalyst is a catalyst comprising one or more compounds selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, a basic nitrogen compound, and a basic phosphorus compound. The linear polycarbonate according to claim 7, 9. The compound according to claim 4, wherein the mixture of the aromatic cyclic carbonates is at least one compound selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, a basic nitrogen compound, and a basic phosphorus compound. A method for producing a linear polycarbonate, comprising melt-polymerizing in the presence of a catalyst comprising: