JPH08302005A - Method for producing polycarbonate - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a polycarbonate with improved fluidity and moldability without lowering the heat resistance due to hydrolysis when producing a polycarbonate by the transesterification method. [Structure] (A) An aromatic dihydroxy compound, (B) an aliphatic polyhydric alcohol and (C) a carbonic acid diester are subjected to a transesterification reaction to produce a polycarbonate, which comprises (A), (B) and (C) The relationship of (C) / [(A) + (B)]> 1 should be satisfied between the molar ratios of the charged amounts of the respective components.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a highly fluid polycarbonate. More specifically, it relates to a method for producing a polycarbonate having a high fluidity and an unreacted hydroxy group of 50 mol% or less by utilizing a transesterification reaction.

[0002]

2. Description of the Related Art Polycarbonate has excellent transparency and heat resistance as well as impact resistance, and is widely used as a so-called engineering plastic in the fields of electricity, electronics, automobiles, optical parts, and other industrial materials. . At present, there are roughly two types of known methods for producing polycarbonate, one of which is a method of directly reacting an aromatic dihydroxy compound with phosgene (usually called an interfacial polycondensation method). The other is a method of transesterifying an aromatic dihydroxy compound and diphenyl carbonate in a molten state (usually called a melt polymerization method or a transesterification method). It is also known that there are differences in various physical properties, and the above-mentioned production methods are properly used according to various conditions and the purpose of use of the polymer.

In the above-mentioned interfacial polycondensation method, toxic phosgene must be used, equipment corrosion measures by chlorine-containing compounds (hydrogen chloride, sodium chloride, etc.) produced as a by-product must be taken, and the physical properties of the polymer are adversely affected. There are many problems such as difficulty in separating impurities (sodium hydroxide, etc.) that cause On the other hand, the transesterification method (melt polymerization method) is currently said to be an inexpensive production method as compared with the case of the above interfacial polycondensation method, but it is usually 280 ° C. because of its high melt viscosity during polymerization. The polymerization reaction is carried out at a high temperature of ~ 310 ° C. In addition to the problem that the molding temperature of the produced polycarbonate is high, the longer the melting time at high temperature is, like other polymers, the greater the influence on the molded product, such as the decrease in the transparency and color tone of the molded product.

An example of a method for producing a polycarbonate having such a reduced melt viscosity and improved moldability is disclosed in Japanese Patent Laid-Open No. 63-92642. In the method described here, 100 mol% of bisphenol and 1 to 10 mol% of aliphatic polyhydric alcohol are used in combination as a so-called polyhydric hydroxy compound which is a polycarbonate raw material, and diaryl carbonate is added thereto (the amount of addition is limited. However, it is 100 mol% in the examples). However, according to the method disclosed herein, the molar ratio of the bisphenol and the diaryl carbonate used is 1, and considering the combined use of the aliphatic polyhydric alcohol, the molar number of the polyhydric hydroxy compound is more than the molar number of the diaryl carbonate. Is also large,
Even if the transesterification reaction is carried out completely, unreacted hydroxy groups will remain. The residue of the unreacted hydroxy group lowers the hydrolysis resistance of the polycarbonate, which in turn lowers the thermal stability, which is not preferable. It should be noted that the above-mentioned known document does not disclose the technical idea of determining the amount of the diaryl carbonate used in consideration of the unreacted hydroxy group.

[0005]

Therefore, in the case of producing a polycarbonate by the transesterification method (melt polymerization method), the deterioration of heat resistance and the like due to hydrolysis does not occur, and the fluidity and moldability of the composition are improved. The advent of methods of obtaining improved polycarbonate boats has been desired. Therefore, an object of the present invention is to complete a manufacturing method that satisfies the above requirements when manufacturing a polycarbonate boat by a transesterification method (melt polymerization method).

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that when a polycarbonate is produced by a transesterification method, an aromatic dihydroxy compound and an aliphatic polyhydric alcohol are used in combination. Moreover, it was found that by using a large amount of carbonic acid diester in excess of a predetermined value, the hydroxyl group terminal at the terminal of the polycarbonate is 50% or less, and the fluidity and hydrolysis resistance are improved, and the present invention was completed. did. That is, the gist of the present invention is as follows.

(1) In a method for producing a polycarbonate by transesterifying (A) an aromatic dihydroxy compound, (B) an aliphatic polyhydric alcohol and (C) a carbonic acid diester, (A), (B) And the molar ratio of the charged amounts of the respective components of (C) have a relationship of (C) / [(A) + (B)]> 1. (Second) Production of the polycarbonate according to the first aspect, wherein the molar ratio of the charged amounts of the components (A) and (B) has a relationship of (B) / (A) = 0.1 to 30%. Method. (3) The method for producing a polycarbonate according to the above 1 or 2, wherein the aromatic dihydroxy compound (A) is a bisphenol. (4) The method for producing a polycarbonate according to the above 1 or 2, wherein the aliphatic polyhydric alcohol (B) is an aliphatic dihydric alcohol. (Fifth) The method for producing a polycarbonate according to the fourth aspect, wherein the aliphatic dihydric alcohol is 1,4-butanediol. (Sixth) The method for producing a polycarbonate according to the first above, wherein the carbonic acid diester (C) is diphenyl carbonate.

One of the aromatic dihydroxy compounds of the component (A) used in the present invention is represented by the general formula (I)

[0009]

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Examples thereof include compounds represented by:
In the above general formula (I), R¹And R ²Are each
Halogen atom of fluorine, chlorine, bromine, iodine or carbon number 1
~ 8 alkyl groups, such as methyl group, ethyl group, n-type
Ropyl group, isopropyl group, n-butyl group, isobutyl
Group, sec-butyl group, t-butyl group, pentyl group,
Xyl group, cyclohexyl group, heptyl group, octyl group
Etc. R¹And R ²Different from each other
It may be. Also R¹If there are multiple R
¹R may be the same or different and R²If there are multiple
Is multiple R²May be the same or different. m and n
Are integers of 0 to 4, respectively. Z is a single bond, carbon number
1-8 alkylene group, 2-8 carbon alkylidene
Group, C5-C15 cycloalkylene group, C5-C5
15 cycloalkylidene groups, or -S-, -SO-,
-SO₂-, -O-, -CO- bond, formula (II) or
(III)

[0011]

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The bond represented by As the alkylene group having 1 to 8 carbon atoms and the alkylidene group having 2 to 8 carbon atoms,
Examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an ethylidene group, and an isopropylidene group. Examples of the cycloalkylene group having 5 to 15 carbon atoms and the cycloalkylidene group having 5 to 15 carbon atoms Examples include a cyclopentylene group, a cyclohexylene group, a cyclopentylidene group, and a cyclohexylidene group.

Examples of the aromatic dihydroxy compound represented by the above general formula (I) include bis (4-hydroxyphenyl) methane; bis (3-methyl-4-hydroxyphenyl) methane; bis (3-chloro-4). -Hydroxyphenyl) methane; bis (3,5-dibromo-4-hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl) ethane; 1,1-bis (2-t-butyl-4-)
Hydroxy-3-methylphenyl) ethane; 1-phenyl-1,1-bis (3-fluoro-4-hydroxy-3)
-Methylphenyl) ethane; 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A);
2,2-bis (3-methyl-4-hydroxyphenyl)
Propane; 2,2-bis (2-methyl-4-hydroxyphenyl) propane; 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane; 1,1-bis (2-t-butyl-) 4-Hydroxy-5-methylphenyl) propane; 2,2-bis (3-chloro-4-hydroxyphenyl) propane; 2,2-bis (3-fluoro-4-hydroxyphenyl) propane; 2,2-bis (3-bromo-4-hydroxyphenyl) propane;
2,2-bis (3,5-difluoro-4-hydroxyphenyl) propane; 2,2-bis (3,5-dichloro-)
4-hydroxyphenyl) propane; 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane; 2,2-bis (4-hydroxyphenyl) butane;
2,2-bis (4-hydroxyphenyl) octane;
2,2-bis (4-hydroxyphenyl) phenylmethane; 2,2-bis (4-hydroxy-1-methylphenyl) propane; 1,1-bis (4-hydroxy-t-butylphenyl) propane; 2, 2-bis (4-hydroxy-3-bromophenyl) propane; 2,2-bis (4
-Hydroxy-3,5-dimethylphenyl) propane;
2,2-bis (4-hydroxy-3-chlorophenyl)
Propane; 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane; 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane; 2,2-
Bis (3-bromo-4-hydroxy-5-chlorophenyl) propane; 2,2-bis (3-phenyl-4-hydroxyphenyl) propane; 2,2-bis (4-hydroxyphenyl) butane; 2,2- Bis (3-methyl-4
-Hydroxyphenyl) butane; 1,1-bis (2-butyl-4-hydroxy-5-methylphenyl) butane;
1,1-bis (2-t-butyl-4-hydroxy-5-
Methylphenyl) butane; 1,1-bis (2-t-butyl-4-hydroxy-5-methylphenyl) isobutane; 1,1-bis (2-t-amyl-4-hydroxy-)
5-methylphenyl) butane; 2,2-bis (3,5-
Dichloro-4-hydroxyphenyl) butane; 2,2-
Bis (3,5-dibromo-4-hydroxyphenyl) butane; 4,4-bis (4-hydroxyphenyl) heptane; 1,1-bis (2-t-butyl-4-hydroxy-)
5-methylphenyl) heptane; 2,2-bis (4-hydroxyphenyl) octane; bis (hydroxyaryl) such as 1,1- (4-hydroxyphenyl) ethane
Alkanes; 1,1-bis (4-hydroxyphenyl)
Cyclopentane; 1,1-bis (4-hydroxyphenyl) cyclohexane; 1,1-bis (3-methyl-4-)
Hydroxyphenyl) cyclohexane; 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane; 1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane; 1,1-bis (4-hydroxyphenyl) Bis (hydroxyaryl) cycloalkanes such as -3,5,5-trimethylcyclohexane; bis (4-hydroxyphenyl) ether; bis (hydroxyaryl) ethers such as bis (4, -hydroxy-3-methylphenyl) ether Kind; screw (4
-Hydroxyphenyl) sulfide; bis (hydroxyaryl) sulfides such as bis (3-methyl-4-hydroxyphenyl) sulfide; bis (4-hydroxyphenyl) sulfoxide; bis (3-methyl-4-hydroxyphenyl) sulfoxide; Bis (hydroxyaryl) sulfoxides such as bis (3-phenyl-4-hydroxyphenyl) sulfoxide; bis (4hydroxyphenyl) sulfone; bis (3-methyl-4-hydroxyphenyl) sulfone; bis (3-phenyl-4)
-Bis (hydroxyaryl) sulfones such as -hydroxyphenyl) sulfone, 4,4'-dihydroxybiphenyl;4,4'-dihydroxy-2,2'-dimethylbiphenyl;4,4'-dihydroxy-3,3'-Dimethylbiphenyl;4,4'-dihydroxy-3,3'-
Dicyclohexylbiphenyl; 3,3'-difluoro-
Examples thereof include dihydroxybiphenyls such as 4,4′-dihydroxybiphenyl. Of these, bisphenol A is the most preferable because it has a good balance of the quality of the obtained polycarbonate and is inexpensive in itself.

Examples of aromatic dihydroxy compounds other than the above general formula (I) include dihydroxybenzenes, halogen- and alkyl-substituted dihydroxybenzenes. For example, resorcin, 3-methylresorcin, 3-ethylresorcin, 3-propylresorcin, 3-butylresorcin, 3-t-butylresorcin, 3-phenylresorcin, 3-cumylresorcin; 2,3,4,6- Tetrafluororesorcin; 2,3,4,6-tetrabromoresorcin; catechol, hydroquinone, 3-methylhydroquinone, 3-ethylhydroquinone, 3-propylhydroquinone, 3-butylhydroquinone, 3-
t-butylhydroquinone, 3-phenylhydroquinone, 3-cumylhydroquinone; 2,5-dichlorohydroquinone; 2,3,5,6-tetramethylhydroquinone; 2,3,4,6-tetra-t-butylhydroquinone; 2,3,5,6-tetrafluorohydroquinone; 2,3,5,6-tetrabromohydroquinone and the like.

There are various kinds of aliphatic polyhydric alcohols as the component (B). For example, butane-1,4
-Diol; 1,2-propanediol; 1,3-butanediol; 1,5-pentanediol; 1,5-hexanediol; hexane-1,6-diol; 2,2-
Dimethylpropane-1,3-diol; ethylene glycol; diethylene glycol; triethylene glycol; tetraethylene glycol; octaethylene glycol; dipropylene glycol; N, N-methyldiethanolamine; cyclohexane-1,3-diol; cyclohexane-1 , 4-diol; 1,4-dimethylolcyclohexane; p-xylylene glycol; 2,2
-Bis- (4-hydroxycyclohexyl) -propane and ethoxylated or propoxylated products of dihydric alcohols or phenols, such as bis-oxyethyl-bisphenol A; bis-oxyethyl-tetrachlorobisphenol A or bis-oxyethyl-tetrachlorohydroquinone And so on.

The use of the component (B) is effective in improving the fluidity of the polycarbonate, but as the above-mentioned aliphatic polyhydric hydroxy compound of the component (B), a dihydric alcohol is most preferable, and among them, 4-butanediol
It is particularly preferable in terms of fluidity and thermal properties of the obtained polycarbonate. The reason why dihydric alcohol is the most preferable is
Aromatic dihydroxy compounds, which are polyhydroxy compounds, and dihydric alcohols are randomly or block-copolymerized via a carbonate group, and either hydroxy group end is blocked with a phenoxy group or the like derived from carbonic acid diester. This is because that. Trivalent or higher hydroxy compound,
For example, in the case of glycerin, when the amount used is small, the effect of improving the fluidity, which is the object of the present invention, can be exhibited, but as the amount used increases, the crosslinking reaction may proceed, which is the opposite of the above. This is because the liquidity tends to decrease. The aliphatic polyhydroxy compound as the component (B) may be used alone or in combination of two or more.

On the other hand, in the present invention, various kinds of carbonic acid diesters are used as the component (C). For example, a diaryl carbonate compound, a dialkyl carbonate compound, or an alkylaryl carbonate compound can be mentioned. This diaryl carbonate compound has the general formula (IV)

[0018]

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(Wherein Ar ¹ and Ar ² each represent an aryl group, and they may be the same or different from each other), or the general formula (V)

[0020]

[Chemical 4]

(In the formula, Ar ³ and Ar ⁴ each represent an aryl group, which may be the same or different, and D ¹ represents a residue obtained by removing two hydroxyl groups from the aromatic dihydroxy compound. .) Can be mentioned. The dialkyl carbonate compound has the general formula (VI)

[0022]

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(In the formula, R ³ and R ⁴ each have 1 carbon atom.
~ 6 alkyl group or C4-7 cycloalkyl group, which may be the same or different from each other. ) Or a compound represented by the general formula (VII)

[0024]

[Chemical 6]

(In the formula, R ⁵ and R ⁶ each have 1 carbon atom.
Indicates 6 alkyl group or a cycloalkyl group having a carbon number of 4-7 and may be the same with or different from each other, a hydroxyl group D ² is from the aromatic dihydroxy compound 2
The residues except for the above are shown. ) Is a compound represented by. The alkyl aryl carbonate compound has the general formula (VIII)

[0026]

[Chemical 7]

(Wherein Ar ⁵ represents an aryl group, R ⁷ represents an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 4 to 7 carbon atoms), or a general formula (IX)

[0028]

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(In the formula, Ar ⁶ is an aryl group, R ⁸ is an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 4 to 7 carbon atoms, and D ³ is the aromatic dihydroxy compound from which two hydroxyl groups have been removed. The compound represents a residue.).

Here, as the diaryl carbonate compound,
For example, diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, bisphenol A bisphenyl carbonate and the like can be mentioned. Examples of the dialkyl carbonate compound include diethyl carbonate, dimethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, bisphenol A bismethyl carbonate, and the like. Examples of the alkyl aryl carbonate compound include methyl phenyl carbonate, ethyl phenyl carbonate, butyl phenyl carbonate, cyclohexyl phenyl carbonate, and bisphenol A methyl phenyl carbonate. In the present invention, as the carbonic acid diester of the component (C), one kind or two or more kinds of the above compounds are appropriately selected and used. Among these, diphenyl carbonate is highly reactive and inexpensive per se. And is preferably used.

The amount of the polyhydric alcohol added is not particularly limited, but the addition of the polyhydric alcohol has the effect of improving the fluidity of the polycarbonate. Is lowered, which is not preferable. On the other hand, if the amount is too small, the fluidizing effect will not be exhibited. Therefore, the ratio (B) / (A) of the amounts charged into the reaction system is preferably about 0.1 to 30% in terms of molar ratio.

In order to exert the effect of the present invention, the amount of the component (C) added is important, and (C) / [(A) + (B)]> 1 (however, the charge to the reaction system is It is a ratio of amounts and a unit is a molar ratio.). If this charging ratio is 1 or less, a large amount of hydroxy groups exceeding 50 mol% remain in the terminal groups of the produced polymer, resulting in poor hydrolysis resistance and heat resistance, which is not preferable. If it is larger than 1 as described above, stoichiometrically, transesterification should be completely carried out, and there should be no hydroxy group at the terminal group of the polymer ((B) component is an aliphatic divalent group). For alcohol). However, experimentally, it is difficult to block all of them with an alkoxy group derived from carbonic acid diester, a phenoxy group, etc., and the hydroxy group residual rate is 50 mol%.
Less than Nevertheless, there is no problem in hydrolysis resistance and heat resistance, and a highly fluid polycarbonate can be obtained.

Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is not limited to these Examples.

【Example】

Example 1 Bisphenol A (BPA) 22.8 was placed in a nickel steel autoclave equipped with a stirrer and having an internal volume of 100 ml.
g (0.10 mol) and 0.34 g of 1,4-butanediol
(0.004 mol) and diphenyl carbonate 23.5
g (0.110 mol) was added. As a catalyst, tetramethylammonium hydroxide 2.5 × 10 ⁻⁴ mol / BPA 1 mol and tetraphenylphosphonium tetraphenylborate 1 × 10 ⁻⁵ mol / BPA 1 mol were added, and nitrogen substitution was carried out 5 times. The mixed solution was heated to 180 ° C. and reacted for 30 minutes under an argon atmosphere. Then
The temperature is raised to 210 ° C., the degree of vacuum is gradually raised to 100 mmHg, the reaction is performed for 30 minutes, and the temperature is further raised to 240 ° C.,
The vacuum degree was gradually raised to 10 mmHg and the reaction was performed for 30 minutes. Next, the temperature is raised to 270 ° C., the degree of vacuum is raised to 2 mmHg, and after reacting for 30 minutes, the degree of vacuum is 0.3 mmHg.
Was reacted for 30 minutes to complete the reaction. Next, the viscosity average molecular weight of the viscous and transparent condensate in the autoclave was determined, and the melt index and steam resistance of the condensate were evaluated. The viscosity average molecular weight Mv is 20 ° C.
The intrinsic viscosity [η] of methylene chloride in methylene chloride was calculated and calculated from the following formula. [Η] = 1.23 × 10 ⁻⁵ × Mv ^{0.83 The} terminal fraction was calculated by the following formula from the H integrated value of the ¹ H-NMR peak. Hydroxyl end / Phenyl end = I _6.72PPM / I _7.43PPM Melt index (MI) is 230 ° C., load 2.01
The extrusion rate from a 1 mmφ × 10 mmL nozzle was measured in Kg (g / 10 minutes). The hydrolysis resistance was evaluated by press molding the condensate to prepare a plate having a thickness of 1 mm and a diameter of 10 mm, exposing the plate to steam at 121 ° C. for 48 hours, and observing the appearance and a decrease in the viscosity average molecular weight (ΔMv). did. The results are shown in Table 1.

Example 2 In place of 1,4-butanediol in Example 1,
The procedure of Example 1 was repeated except that 0.58 g (0.04 mol) of cyclohexanedimethanol was used. The result is first
Shown in the table.

Comparative Example 1 23.5 g of diphenyl carbonate in Example 1
Instead of (0.110 mol), 21.8 g (0.102 mol)
Was carried out in the same manner as in Example 1 except that was used. The results are shown in Table 1.

Comparative Example 2 228 g (1.0 mol) of bisphenol A, 21.8 g (1.02 mol) of diphenyl carbonate and 3.6 g (0.04 mol) of 1,4-butanediol were mixed in a vertical reaction of 1 liter. The mixture was placed in a container and, after purging with nitrogen, melted at 180 ° C. Add 0.0001 mol of lithium carbonate as a transesterification reaction catalyst, gradually raise the temperature to 280 ° C over about 5 hours, and perform transesterification reaction while gradually raising the vacuum degree from normal pressure to 1 mmHg, and continuously The raw phenol was distilled off. Then, the vacuum was broken and a polymer was obtained under a normal pressure of nitrogen purge. The results are shown in Table 1.

[0038]

[Table 1]

[0039]

As described above, according to the present invention, in the method for producing a polycarbonate by a transesterification reaction, the number of moles of the carbonic acid diester is larger than the total number of moles of the aromatic dihydroxy compound and the aliphatic polyhydric alcohol. In this case, and preferably in this case, the molar ratio of the aliphatic polyhydric alcohol to the aromatic dihydroxy compound is 0.1 to 30%, whereby the molar ratio of the hydroxyl group terminal to the phenyl terminal becomes extremely high. Since it can be lowered, the hydrolysis resistance of the polymer could be improved. Furthermore, even if the viscosity average molecular weight is the same as before,
We have succeeded in obtaining a polymer with high fluidity.

Claims (6)

[Claims] 1. A method for producing a polycarbonate by subjecting (A) an aromatic dihydroxy compound, (B) an aliphatic polyhydric alcohol and (C) a carbonic acid diester to a transesterification reaction, wherein (A), (B) and ( A method for producing a polycarbonate, characterized in that the relationship of (C) / [(A) + (B)]> 1 is satisfied between the molar ratios of the charged amounts of the respective components of C). 2. The polycarbonate according to claim 1, wherein the molar ratio of the charged amounts of the components (A) and (B) has a relationship of (B) / (A) = 0.1 to 30%. Production method. 3. The method for producing a polycarbonate according to claim 1, wherein the aromatic dihydroxy compound (A) is a bisphenol. 4. The method for producing a polycarbonate according to claim 1, wherein the aliphatic polyhydric alcohol (B) is an aliphatic dihydric alcohol. 5. The method for producing a polycarbonate according to claim 4, wherein the aliphatic dihydric alcohol is 1,4-butanediol. 6. The method for producing a polycarbonate according to claim 1, wherein the carbonic acid diester (C) is diphenyl carbonate.