JPH0782367A - Production of aromatic polycarbonate - Google Patents

Abstract

PURPOSE:To produce a high-mol.-wt. arom. polycarbonate having a good hue by transesterification. CONSTITUTION:An arom. polycarbonate is produced by the melt polycondensation of an arom. diol compd. with a carbonic diester compd. using a transesterification catalyst under the condition that the melt polycondensation is conducted in the presence of an organosilicon compd. having at least two glycidyl ether groups or a polyfunctional organosilicon compd. having at least one glycidyl ether group and a group of the formula: -SiR<1>n(OR<2>)3-n [wherein R<1> is a1-6C aliph. hydrocarbon group; R<2> is a 1-6C aliph. or 6-10C arom. hydrocarbon group; and n is an integer of 0-2].

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polycarbonate by a transesterification reaction. For more details,
The present invention relates to a method for producing a high-molecular weight aromatic polycarbonate having an improved hue from an aromatic diol compound and a carbonic acid diester compound by a melt polycondensation reaction.

[0002]

2. Description of the Related Art In recent years, aromatic polycarbonate has been used as a carbonated beverage bottle, an electronic substrate (CD substrate), a transfer sheet as an engineering plastic excellent in mechanical properties such as impact resistance, heat resistance and transparency. Belts, etc.
Widely used in many fields.

As a method for producing this aromatic polycarbonate, a so-called phosgene method in which an aromatic diol such as bisphenol and phosgene are reacted by an interfacial polycondensation method has been industrialized. However, the phosgene method currently used industrially requires the use of extremely toxic phosgene, and a large amount of by-produced sodium chloride is mixed into the aromatic polycarbonate produced, resulting in corrosion of the molding machine. To the cause of the above, or the need for a post-treatment step to remove this sodium chloride, the problem of treating the waste solution of sodium chloride, and the hygiene of methylene chloride, which is usually used as a reaction solvent, and the atmospheric environment problem. Many problems have been pointed out, including concerns about the.

On the other hand, a method of obtaining an aromatic polycarbonate by transesterification between an aromatic diol compound and a carbonic acid diester has long been known as a so-called melting method or non-phosgene method. The non-phosgene method is said to have an advantage that an aromatic polycarbonate can be produced at a lower cost without the various problems of the phosgene method as described above.

However, in the transesterification method, the degree of polymerization cannot be increased unless the low-molecular-weight substance produced as a by-product from the high-viscosity polymer melt is distilled off.
Usually at a high temperature of 280-310 ° C and 1 Torr (To
It is necessary to react for a long time under a high vacuum of about rr) or less, and as a result, branching or cross-linking is likely to occur due to side reaction, and further, the polycarbonate is unavoidably markedly colored,
It had drawbacks such as not being able to obtain good quality polycarbonate (Mikio Matsugane et al., Plastic Materials Course [5]
"Polycarbonate resin" Nikkan Kogyo Shimbun (196
9), pp. 62-67).

As one of the methods for solving the above problems, it is possible to increase the amount of catalyst for transesterification to increase the reaction rate and shorten the reaction time. In this method, the catalyst residue in the polymerized polymer is used. This causes deterioration of quality (for example, heat resistance and hue of polycarbonate), which is not preferable. Generally, a high molecular weight polycarbonate is superior in mechanical properties such as bending strength, tensile strength and impact strength to a low molecular weight polycarbonate.

[0007]

It is an object of the present invention to provide a method for producing a polycarbonate by a transesterification method without increasing the amount of a transesterification catalyst used.
An object of the present invention is to provide a method capable of efficiently producing an aromatic polycarbonate having a sufficiently high molecular weight and a good hue.

[0008]

The present invention provides a method for producing an aromatic polycarbonate by subjecting an aromatic diol compound and a carbonic acid diester compound to a melt polycondensation reaction using a transesterification reaction catalyst. The reaction
An organosilicon compound having two or more glycidyl ether groups, or at least one glycidyl ether group and a group represented by the following formula (I)

[0009]

Embedded image —SiR ¹ _n (OR ² ) _3-n (I)

[In the formula, R ¹ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and R ² is an aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. It is a hydrocarbon group, and n is an integer of 0-2. ] It is provided in the presence of a polyfunctional organosilicon compound having the above.

[0011]

DETAILED DESCRIPTION OF THE INVENTION Aromatic Diol Compound The aromatic diol compound used in the production of the present invention is
It is a compound represented by the general formula [II].

[0012]

[Chemical 3]

(In the formula, A is a single bond, a substituted or unsubstituted linear, branched or cyclic divalent hydrocarbon group having 1 to 15 carbon atoms, and -O-, -S-, -CO. -, -SO-, -S
It is selected from the group consisting of divalent groups represented by O ₂ —, X and Y are the same or different from each other and are selected from hydrogen or halogen or a hydrocarbon group having 1 to 6 carbon atoms. And p and q are integers of 0-2. )

Some representative examples are, for example, bis (4-hydroxydiphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl). propane,
2,2-bis (4-hydroxy-3-t-butylphenyl) propane, 2,2-bis (4-hydroxy-3,5
-Dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromo) propane, 4,4-bis (4-hydroxyphenyl) heptane, 1,1-bis (4-hydroxyphenyl) cyclohexane, etc. Bisphenol; 4,4'-dihydroxybiphenyl, 3,
Biphenols such as 3 ', 5,5'-tetramethyl-4,4'-biphenyl; bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide,
Bis (4-hydroxyphenyl) ether, bis (4-
Hydroxyphenyl) ketone and the like.

Of these, 2,2-bis (4-hydroxyphenyl) propane is preferable. Two or more kinds of these compounds may be used in combination (copolymer), or when a branched aromatic polycarbonate is to be produced, a small amount of trihydric or higher polyhydric phenol may be copolymerized. . Further, for the purpose of further improving the thermal stability and hydrolysis resistance of the aromatic polycarbonate produced, monovalent compounds such as pt-butylphenol and p-cumylphenol are used for the purpose of sealing the hydroxyl terminal. Phenols can also be used.

[0016] Representative examples of the carbonic diester used in the carbonic acid diester present invention,
There are dimethyl carbonate, diphenyl carbonate, ditolyl carbonate, bis (4-chlorophenyl) carbonate, bis (2,4,6-trichlorophenyl) carbonate and the like. These carbonic acid diester compounds are
It is generally used in excess with respect to 1 mol of the aromatic diol compound, and it is desirable to use it in an amount of 1.01 to 1.30 mol, preferably 1.02 to 1.20 mol.

Transesterification Reaction Catalyst As typical examples of the transesterification reaction catalyst used in the present invention, specifically, alkali metals such as lithium, sodium, potassium and cesium, alkaline earth metals such as magnesium, calcium and barium, Well-known transesterification reactions such as acetates, carbonates, borates, nitrates, oxides, hydroxides, hydrides or alcoholates of metals such as zinc, cadmium, tin, antimony, manganese, cobalt, nickel, titanium and zirconium. Examples thereof include metal compound catalysts, and tin compound catalysts and alkali metal catalysts are preferably used. Also, two or more of these may be used in combination.

Specifically, lithium hydroxide, potassium hydroxide, sodium hydroxide, rubidium hydroxide, cesium hydroxide, lithium borohydride, potassium borohydride, lithium carbonate, rubidium carbonate, cesium carbonate, sodium hydrogen carbonate. , Potassium hydrogen carbonate, cesium hydrogen carbonate, sodium acetate, potassium acetate, rubidium acetate,
Cesium acetate, phenoxy lithium, phenoxy sodium, phenoxy potassium, phenoxy rubidium, phenoxy cesium, tin oxide (IV), tin (IV) nitrate,
Tin (IV) acetate, dibutyltin oxide, diphenyltin oxide, dibutyltin laurate and the like can be used. These catalysts are used in an amount of 10 ⁻⁸ to 10 ⁻³ mol, preferably 10 ⁻⁷ to 10 ⁻⁴ mol with respect to 1 mol of the aromatic diol compound used as a raw material.

Polyfunctional Organosilicon Compound A feature of the present invention is that an aromatic polycarbonate is produced by using the polyfunctional organosilicon compound under the melt exchange polycondensation reaction conditions of the transesterification method. This organosilicon compound is a glycidyl ether group represented by the following formula (III)

[0020]

[Chemical 4]

An organosilicon compound having two or more groups, or at least one glycidyl ether group represented by the above formula (III) and at least one group represented by the formula (I)

[0022]

Embedded image —SiR ¹ _n (OR ² ) _3-n (I)

[In the formula, R ¹ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms, and R ² is an aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. It is a hydrocarbon group, and n is an integer of 0-2. ] It is a polyfunctional organosilicon compound having. In particular,

[0024]

[Chemical 6]

[0025]

[Chemical 7]

Etc. can be used. Among them, 3-glycidoxypropyltrimethoxysilane or bis (3-glycidoxypropyl) tetramethyldisiloxane is preferable.
The amount of the polyfunctional organosilicon compound used in the method of the present invention is 0.001 to 0.1 mol, preferably 0.001 mol, per 1 mol of the aromatic diol compound.
It is used in the range of 2 to 0.05 mol.

If the amount of the polyfunctional silicon compound used is too small, a high molecular weight polycarbonate cannot be obtained. On the other hand, if the amount is too large, unreacted polyfunctional silicon compound remains in the formed polycarbonate, which adversely affects the quality of the aromatic polycarbonate. The polyfunctional organosilicon compound may be added at any stage during the transesterification melt polycondensation step as long as the effect is recognized. For convenience, it can be used by adding it from the initial stage of the reaction at the same time as the raw material monomer such as an aromatic diol compound, a carbonic acid diester compound and a transesterification reaction catalyst.
It can also be added and used in the final stage of the polycondensation reaction process.

The transesterification melt polycondensation method in the present invention can be carried out by a known melt polycondensation method of aromatic polycarbonate except that a polyfunctional organosilicon compound is used in any of the reaction steps.
(H. Schnell, "Chemistry and
Physics of Polycarbonate
s ", published by Interscience, Inc., 1964).

That is, melt polycondensation is carried out using the above-mentioned raw materials, transesterification catalyst, polyfunctional organosilicon compound, etc. while removing by-products by transesterification under heating / normal pressure or reduced pressure. The reaction is generally carried out in a multi-step process of two or more steps. In the first-step reaction, the raw material and the catalyst are heated to 100 ° C. under an inert gas atmosphere under normal pressure or pressure.
It was carried out by heating to a temperature of 200 ° C., during which transesterification and low molecular weight oligomers (number average molecular weight 40
The formation reaction of 0 to 1,000) occurs. In the second-step reaction, the system is further heated (200 ° C. to 250 ° C.) and the alcohol or phenol generated by reducing the pressure (20 Torr. Or less) is removed from the reaction system to reduce the transesterification reaction. The formation of a molecular weight oligomer and its chain extension reaction are allowed to proceed (number average molecular weight 1,000 to 7,000). Furthermore, in order to extend the chain length of the oligomer, a high temperature (250 ° C to 330 ° C) is used.
A high-molecular-weight aromatic polycarbonate can be obtained by removing mainly alcohols or phenols and carbonic acid diesters from the reaction system under conditions of high vacuum (1 Torr. Or less).

The reaction time of each step can be appropriately determined according to the degree of progress of the reaction, but from the viewpoint of the hue of the obtained polymer, even if the reaction time is slightly longer under the temperature condition of about 200 ° C. It does not have a bad effect on
Generally, 0.5 to 5 hours, 0.1 to 3 hours at a temperature of 200 to 250 ° C., and long reaction at a reaction temperature of more than 250 ° C. have a marked adverse effect on hue. Therefore, it is preferable that the reaction time in the final step is within 1 hour, preferably 0.1 to 1 hour (although it is related to the molecular weight).

The polyfunctional organosilicon compound of the present invention is added and used in any of the above reaction steps. The reaction can be carried out batchwise or continuously, and various apparatuses can be used. Usually, different types of reactors are used for each reaction stage. The structure of the reaction apparatus used in the present invention is not particularly limited, but since the viscosity increases remarkably in the latter stage of the reaction, it is preferable to have a high-viscosity stirring function.

The number average molecular weight (Mn) of the aromatic polycarbonate obtained by the method of the present invention is about 1,000 to.
It is about 15,000, and the weight average molecular weight (Mw) is
It has a high molecular weight of about 2,500 to 40,000, and the Mw / Mn value is preferably 2 to 4. Further, the hydroxyl group concentration of the polycarbonate is preferably about 0.2% by weight or less. Further, the value of hue (UV, A ₃₄₅ ) described later is 0.0
It is preferably 5 or less.

[0033]

EXAMPLES Hereinafter, the method of the present invention will be specifically described with reference to Examples. The aromatic polycarbonate obtained by the present invention was analyzed by the following measuring method. (I) Molecular weight This is the molecular weight in terms of GPC (HLC-8020 manufactured by Tosoh Corporation) polycarbonate at 35 ° C using a chloroform solvent. (Ii) Hue 4% of the sample which was heat-melted at 300 ° C. for 15 minutes
Prepare a methylene chloride solution, UV spectrum 345n
The absorbance at the wavelength of m was measured. The larger this value is, the more colored it is.

Example 1 Bisphenol A 1.0 mol (228 g), diphenyl carbonate 1.08 mol (231 g), 3-glycidoxypropyltrimethoxysilane 4.95 × 10 ⁻³ mol (1.17 g) and as a catalyst 0.20 mmol (50 mg) of dibutyltin oxide was placed in a reaction vessel made of SUS equipped with a stirrer and a distillation device having an internal volume of 3 liters, heated to 150 ° C. under a nitrogen gas atmosphere, and kept at the same temperature for 1 hour.
The molten state was maintained for an hour.

Then, after the temperature was raised to 200 ° C., the pressure was gradually increased to 20 Torr. And the state was maintained for 1 hour to distill off the by-produced phenol. Then, the reaction temperature is raised to 250 ° C. and the pressure in the system is set to 0.5 Torr at the same temperature.
r. And polycondensation reaction was carried out for 1 hour to obtain about 250 g of aromatic polycarbonate. The analysis results of this polycarbonate are shown in Table 1.

Example 2 Addition of 3-glycidoxypropyltrimethoxysilane was carried out at 200 ° C., 20 Torr. An aromatic polycarbonate was obtained by carrying out the reaction under the same method and conditions as in Example 1 except that the reaction was carried out under the conditions of 1 hour after the reaction. Table 1 shows the analysis results of the obtained polycarbonate.

Example 3 3-glycidoxypropyltrimethoxysilane was added in the same manner as in Example 1 except that the reaction temperature was raised to 250 ° C. and the temperature was reached. An aromatic polycarbonate having the physical properties shown in was obtained.

Example 4 The same procedure as in Example 3 was repeated except that the amount of 3-glycidoxypropyltrimethoxysilane added was changed to 11.4 g (0.048 mol). Aromatic polycarbonate of was obtained.

Comparative Example 1 An aromatic polycarbonate having the physical properties shown in Table 1 was produced by carrying out the reaction in the same manner as in Example 1 except that 3-glycidoxypropyltrimethoxysilane was not used.

Comparative Example 2 The same method as in Example 1 except that 3-glycidoxypropyltrimethoxysilane was not used and that 1.6 mmol (400 mg) of dibutyltin oxide was used as the transesterification reaction catalyst. Table 1
An aromatic polycarbonate having the physical properties shown in was produced.

Comparative Example 3 No 3-glycidoxypropyltrimethoxysilane was used and the reaction conditions were 250 ° C. and 0.5 To.
rr. The reaction was performed in the same manner as in Example 1 except that the polycondensation reaction time in Example 2 was changed to 2 hours to produce an aromatic polycarbonate having the physical properties shown in Table 1.

[0042]

[Table 1]

Example 5 The same as Example 1 except that 4.94 × 10 ⁻³ mol (1.79 g) of bis (3-glycidoxypropyl) tetramethyldisiloxane was used as the polyfunctional silicon compound. Then, an aromatic polycarbonate having the physical properties shown in Table 2 was produced.

Example 6 Aromatic polycarbonates having the physical properties shown in Table 2 were produced in the same manner except that 1.79 g of bis (3-glycidoxypropyl) tetramethyldisiloxane was used according to the method and conditions of Example 2. .

Example 7 Aromatic polycarbonates having the physical properties shown in Table 2 were produced in the same manner except that 1.79 g of bis (3-glycidoxypropyl) tetramethyldisiloxane was used according to the method and conditions of Example 3. .

[0046]

[Table 2]

[0047]

According to the method of the present invention, an aromatic polycarbonate having a high molecular weight and a good hue can be produced by the transesterification method.

Claims (1)

[Claims] 1. A method for producing an aromatic polycarbonate by subjecting an aromatic diol compound and a carbonic acid diester compound to a melt polycondensation reaction using a transesterification reaction catalyst, wherein the melt polycondensation reaction is carried out by two or more glycidyl compounds. An organosilicon compound having an ether group, or at least one glycidyl ether group and a group represented by the following formula (I): —SiR ¹ _n (OR ² ) _3-n (I) [wherein R ¹ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms, R ² is an aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and n is 0-2
Is an integer. ] It is made to exist in the presence of the polyfunctional organosilicon compound which has these, The manufacturing method of the aromatic polycarbonate characterized by the above-mentioned.