JPH06157738A - Production of aromatic polycarbonate - Google Patents

Abstract

PURPOSE:To efficiently obtain an aromatic polycarbonate excellent in heat resistance and transparency, useful for electronic boards, etc., by melt polycondensation of an aromatic diol compound with a carbonic diester compound in the presence of an ester interchange reaction catalyst and a specific organosilicon compound. CONSTITUTION:This polycarbonate can be obtained by melt polycondensation of an aromatic diol compound such as bis(4-hydroxydiphenyl) methane with a carbonic diester compound such as diphenyl carbonate in the presence of an ester interchange reaction catalyst such as lithium hydride and an organosilicon compound of the formula (R and R' are each H or 1-20C hydrocarbon; (n) is 2-10000) such as 1,1,3,3,-tetramethyldisiloxane.

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 an aromatic polycarbonate having improved heat resistance 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. The heat resistance of the aromatic polycarbonate produced by this phosgene method is 5% as described later.
Approximately 500 ° C when the weight loss heating temperature (Td 5%) is used as a scale
And has high advantages.

However, the phosgene method currently practiced industrially requires the use of extremely toxic phosgene, the problem of treating a large amount of by-produced sodium chloride, and methylene chloride usually used as a reaction solvent. Many problems have been pointed out, such as public health and concerns about atmospheric environment. Further, a method of obtaining an aromatic polycarbonate by transesterification of 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 the advantages that the above-mentioned various problems of the phosgene method do not occur and that the aromatic polycarbonate can be produced at a lower cost.

However, for example, in an aromatic polycarbonate produced from bisphenol A and diphenyl carbonate by the non-phosgene method, it is generally necessary to selectively produce only a polymer having a high molecular weight and having no hydroxyl group structure in its polymer terminal structure. It is said that the presence of the hydroxyl group-terminated polymer thus contained is one of the reasons for the decrease in heat resistance.

That is, the heat resistance of the aromatic polycarbonate obtained by the non-phosgene method is about 445 ° C., which is lower than the heat resistance of the aromatic polycarbonate obtained by the phosgene method (about 500 ° C.), which facilitates the sealing reaction of the hydroxyl terminal structure. It is necessary to mold the aromatic polycarbonate at a high temperature of about 320 ° C., and if the heat resistance of the polycarbonate is low, problems such as cutting of the polymer main chain, coloring, and deterioration of mechanical strength occur. Especially thin molding of hollow containers (0.3-0.6
mm) or a complex shape, a high temperature is particularly required to reduce the melt viscosity, and therefore improvement in heat resistance of the polycarbonate obtained by the non-phosgene method is a problem for practical use.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing an aromatic polycarbonate having high heat resistance even by the above-mentioned transesterification polycondensation method (non-phosgene method).

[0008]

The present invention is a method of melt polycondensing an aromatic diol compound and a carbonic acid diester compound in the presence of a transesterification catalyst and an organosilicon compound having a site represented by the following formula [I]. It is intended to provide a method of reacting to produce an aromatic polycarbonate.

[0009]

[Chemical 2]

[In the formula, R and R'each independently represent hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and n is 2 to 1
It is an integer of 10,000. ]

[Detailed Description] The aromatic diol compound used in the production of the present invention 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 selected from hydrogen, halogen, or a hydrocarbon group having 1 to 6 carbon atoms. And p and q are integers of 0 to 2. ) Some typical examples are 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-)
Bisphenols such as 3,5-dibromo) propane, 4,4-bis (4-hydroxyphenyl) heptane and 1,1-bis (4-hydroxyphenyl) cyclohexane;
4,4'-dihydroxybiphenyl, 3,3 ', 5
Biphenols such as 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 improving the thermal stability and hydrolysis resistance of the aromatic polycarbonate produced, monohydric phenols such as pt-butylphenol and p-cumylphenol are used for the purpose of sealing the hydroxyl terminal. Kinds can also be used.

Representative examples of the carbonic acid diester used in the present invention include 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 generally used in excess with respect to 1 mol of the aromatic diol compound, and are used in an amount of 1.01 to 1.30 mol, preferably 1.02 to 1.20 mol. Is desirable.

As typical examples of the transesterification reaction catalyst used in the present invention, specifically, lithium, sodium,
Alkali metals such as potassium, alkaline earth metals such as magnesium, calcium and barium, acetates, carbonates, borates and nitrates of metals such as zinc, cadmium, tin, antimony, manganese, cobalt, nickel, titanium and zirconium. Well-known transesterification metal compound catalysts such as oxides, hydroxides, hydrides and alcoholates can be mentioned, and tin compound catalysts are preferably used, and these are used in combination of two or more kinds. You can also

Specifically, lithium hydride, lithium borohydride, sodium borohydride, potassium borohydride, rubidium borohydride, cesium borohydride, beryllium borohydride, magnesium borohydride, borohydride. Calcium, strontium borohydride, barium borohydride, aluminum borohydride, titanium borohydride, tin borohydride, germanium borohydride, tetraphenoxy lithium, tetraphenoxy sodium, tetraphenoxy potassium, tetraphenoxy rubidium, tetraphenoxy Cesium, sodium thiosulfate, beryllium oxide, magnesium oxide, tin (IV) oxide, dibutyltin oxide,
Dibutyltin laurate, beryllium hydroxide, magnesium hydroxide, germanium hydroxide, beryllium acetate, magnesium acetate, calcium acetate, tin (IV) acetate, germanium acetate, lithium carbonate, sodium carbonate, potassium carbonate, beryllium carbonate, magnesium carbonate, carbonate Examples thereof include tin (IV), germanium carbonate, tin (IV) nitrate, germanium nitrate, antimony trioxide, and bismuth trimethylcarboxylate.

[0018] These catalysts, ^10-5 to ^10-1 mol of the aromatic diol to 1 mole of the compound used as a raw material, preferably used in an amount of 10 ^-5 to 10 ^-2 mol.
A feature of the present invention is that an aromatic polycarbonate is produced by using the silicon compound represented by the above formula [I] under the conditions of the melt polycondensation reaction by the transesterification method. The silicon compound having a siloxane bond may have a chain structure or a cyclic structure.

As the organosilicon compound, 1,
1,3,3-tetramethyldisiloxane, pentamethyldisiloxane, hexamethyldisiloxane, 1,3-diethyl-1,1,3,3-tetramethyldisiloxane,
1,3-divinyl-1,1,3,3-tetramethyldisiloxane, bis (1-methyl-3-silorenyl) oxide, 1,3-bis (3-hydroxypropyl) -1,
1,3,3-tetramethyldisiloxane, 1,3-bis (2-aminoethylaminomethyl) -1,1,3,3-
Tetramethyldisiloxane, pentamethylpiperidinomethyldisiloxane, hexaethyldisiloxane, 1,3
-Dibutyl-1,1,3,3-tetramethyldisiloxane, 1,3-diphenyl-1,1,3,3-tetramethyldisiloxane, 1,3-bis (dioxanylethyl)
-1,1,3,3-tetramethyldisiloxane, 1,3
-Bis (3-glycidoxypropyl) -1,1,3,3
-Tetramethyldisiloxane, hexapropyldisiloxane, 1,3-dimethyl-1,1,3,3-tetraphenyldisiloxane, hexamethylcyclotrisiloxane, 1,1,3,3,5,5-hexamethyl Trisiloxane, 1,1,1,3,5,5,5-heptamethyltrisiloxane, octamethyltrisiloxane, 1,3,5
-Trimethyl-1,3,5-trivinylcyclotrisiloxane, 1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane, octaphenylcyclotetrasiloxane, 1,3,5,7,9 -Pentamethylcyclopentasiloxane, decamethylcyclopentasiloxane, hexaphenylcyclotrisiloxane, dimethylpolysiloxane, ethylmethylpolysiloxane, methylphenylpolysiloxane, diphenylpolysiloxane,
Examples include methylhydrogenpolysiloxane. These compounds can be used in combination.

Of these, hexaphenylcyclotrisiloxane, octaphenylcyclotetrasiloxane, decamethylcyclopentasiloxane, dimethylpolysiloxane, and methylhydrogenpolysiloxane are particularly preferable. The amount of the organosilicon compound used in the method of the present invention is an amount sufficient to improve the heat resistance of the aromatic polycarbonate by the transesterification method, melt polycondensation method. Generally, it is used in the range of 0.5 to 500 mol, preferably 1 to 300 mol, based on 1 mol of the transesterification catalyst used.

When converted to 1 mol of the aromatic diol, the amount of the organosilane compound used is 5 × 10 ^{−5 to} 5 ×.
An amount of 10 ^-1 mol. The organosilicon compound may be added and used at any stage of the transesterification melt polycondensation step as long as the effect is recognized. For convenience, the aromatic diol compound, the carbonic acid diester compound, the transesterification reaction catalyst, etc., which are the raw material monomers, can be added and mixed at the same time from the initial stage of the reaction, or added at the final stage of the polycondensation reaction process. It can also be used.

The transesterification melt polycondensation method in the present invention can be carried out by a known melt polycondensation method of an aromatic polycarbonate except that an organosilicon compound is used in any of the reaction steps. (HS
chnell; “Chemistry and Ph”
ysics of Polycarbonates ”,
Interscience, 1964).

That is, melt polycondensation is carried out using the above-mentioned raw materials under heating / normal pressure or reduced pressure while removing by-products by transesterification. The reaction is generally carried out in a multi-step process of two or more steps. In the first stage reaction, the raw material and the catalyst are heated to 100 ° C. under an inert gas atmosphere under normal pressure or pressure.
It is carried out by heating to a temperature of ˜200 ° C., during which transesterification and low molecular weight oligomers (number average molecular weight 4
00-1,000) forming reaction 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, the hue may be slightly longer under the temperature condition of about 200 ° C. However, it is generally 0.5 to 5 hours, and at a temperature of 200 to 250 ° C.
When the reaction temperature is 1 to 3 hours and exceeds 250 ° C., the reaction for a long time has a remarkable adverse effect on the 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 organosilicon compound of the present invention is added and used in any of the above reaction steps. The number average molecular weight of the aromatic polycarbonate obtained by the method of the present invention (M
n) is about 2,000 to 30,000, the weight average molecular weight (Mw) has a high molecular weight of about 5,000 to 70,000, and the Mw / Mn value is 2 to 4. preferable.

Further, about 10 parts of this aromatic polycarbonate
When a precise amount of mg is used and the temperature is raised in a nitrogen stream at a temperature rising rate of 20 ° C./min using a thermogravimetric analyzer 200-TG / DTA220 (trade name) manufactured by Seiko Instruments Inc. , The weight of this aromatic polycarbonate is 5% of the original weight.
Assuming that the temperature at which the decrease in temperature reaches% is the heat resistant temperature (Td 5%), this temperature is 445 ° C or higher, preferably 460 to 5
It is 20 ° C. Further, the hydroxyl group concentration of the polycarbonate is preferably about 0.2% by weight or less.

[0027]

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) Hydroxyl group concentration in polycarbonate J. E. Methods such as McGrath (Polymer, p
reprints, 19 (1), 494 (1978))
According to the above, UV spectrum analysis was performed and the hydroxyl group concentration in the polymer sample was determined as% by weight. (Ii) Molecular weight It is the GPC polystyrene conversion molecular weight at 35 ° C. using a chloroform solvent.

Example 1 Bisphenol A 1.0 mol (228 g), diphenyl carbonate 1.08 mol (231 g) and dibutyltin oxide 0.20 mmol (5) as a catalyst.
0 mg) was placed in a SUS reactor equipped with a stirrer and a distillation device having an internal volume of 3 liters, and kept in a molten state at 150 ° C. for 1 hour under a nitrogen atmosphere. 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 phenol. Then, the reaction system is set to 25
Hexaphenylcyclotrisiloxane 1 is heated to 0 ° C.
0 mmol (6.0 g) was added, and the pressure in the system was adjusted to 0.5 Torr. And polycondensation reaction was carried out for 1 hour to obtain about 250 g of a polymer. Table 1 shows the analysis results of the obtained polymer.

Example 2 Bisphenol A 1.0 mol (228 g), diphenyl carbonate 1.08 mol (231 g), hexaphenylcyclotrisiloxane 10 mmol (6.0 g)
Then, 0.20 mmol (50 mg) of dibutyltin oxide as a catalyst was placed in a SUS reactor equipped with a stirrer and a distillation device having an internal volume of 3 liters, and kept in a molten state at 150 ° C. for 1 hour under a nitrogen atmosphere. 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 phenol. afterwards,
The temperature is raised to 250 ° C., and the pressure is further set to 0.5 Torr. And polycondensation reaction was carried out for 1 hour to obtain about 250 g of a polymer. Table 1 shows the analysis results of the obtained polymer.

Comparative Example 1 A polymer was synthesized under the same conditions as in Example 1 except that hexaphenylcyclotrisiloxane was not used. Table 1 shows the analysis results of the obtained polymer.

Examples 2 to 3 All conditions were the same as in Comparative Example 1, except that 0.2 mmol (35 mg) of calcium acetate or 0.2 mmol (1.4 mg) of lithium hydride was used as the transesterification catalyst. A polymer was synthesized by the method. The analysis results of the obtained polymer are shown in Table 1. All of them had low heat resistance.

Example 3 Bisphenol A 1.0 mol (228 g), diphenyl carbonate 1.08 g mol (231 g), octaphenylcyclotetrasiloxane 5 mmol (4.0 g)
g) and dibutyltin oxide 0.2 as catalyst
0 mmol (50 mg) was placed in a SUS reactor equipped with a stirrer and a distillation device having an internal volume of 3 liters, and kept in a molten state at 150 ° C. for 1 hour under a nitrogen atmosphere.

Then, after raising the temperature to 200 ° C., the pressure is gradually increased to 20 Torr. And the state was maintained for 1 hour to distill phenol. Then, raise the temperature to 250 ° C,
Furthermore, the pressure in the system is set to 0.5 Torr. And polycondensation reaction was carried out for 1 hour to obtain about 250 g of a polymer. Table 1 shows the analysis results of the obtained polymer.

Examples 4 to 5 Under the same conditions and methods as in Example 3, except that the amount of octaphenylcyclotetrasiloxane used in Example 3 was changed to the amounts shown in Table 1, respectively. A polymer was synthesized. Table 1 shows the analysis results of the obtained polymer.

Example 6 1.0 mol (228 g) of bisphenol A, 1.08 g mol (231 g) of diphenyl carbonate and 0.20 mmol (50 mg) of dibutyltin oxide as a catalyst were installed in a stirrer and a distillation device having an internal volume of 3 liters. Put it in a SUS reactor and put it under nitrogen atmosphere for 150
The molten state was kept at 0 ° C for 1 hour.

Then, after raising the temperature to 200 ° C., the pressure is gradually increased to 20 Torr. And the state was maintained for 1 hour to distill phenol. Then, raise the temperature to 250 ° C,
Dimethylpolysiloxane (20 cps) (190 mg, 2.5 mmol in terms of molecular weight of unit structure) was added, and the system pressure was adjusted to 0.5 Torr. And polycondensation reaction was carried out for 1 hour to obtain about 250 g of a polymer. Table 1 shows the analysis results of the obtained polymer.

[0037]

[Table 1]

Example 7 A polymer was synthesized using methylhydrogen polysiloxane under the same conditions and method as in Example 6 except that the type of silicon compound was changed. Table 2 shows the analysis results of the obtained polymer.

Example 8 A polymer was synthesized under the same conditions and method as in Example 7, except that the addition amount of methylhydrogen polysiloxane in Example 7 was changed to the amount shown in Table 2. Table 2 shows the analysis results of the obtained polymer.

Example 9 Bisphenol A 1.0 mol (228 g), diphenyl carbonate 1.08 g mol (231 g), decamethylcyclopentasiloxane 2.5 mmol (0.9
g) and dibutyltin oxide 0.2 as catalyst
0 mmol (50 mg) was placed in a SUS reactor equipped with a stirrer and a distillation device having an internal volume of 3 liters, and kept in a molten state at 150 ° C. for 1 hour under a nitrogen atmosphere.

Next, after raising the temperature to 200 ° C., the pressure is gradually increased to 20 Torr. And the state was maintained for 1 hour to distill phenol. Then, raise the temperature to 250 ° C,
Furthermore, the pressure in the system is set to 0.5 Torr. And polycondensation reaction was carried out for 1 hour to obtain about 250 g of a polymer. Table 2 shows the analysis results of the obtained polymer.

Example 10 A polymer was synthesized under the same conditions and methods as in Example 3, except that 0.2 mmol (130 mg) of dibutyltin dilaurate was used as the transesterification catalyst. Table 2 shows the analysis results of the obtained polymer.

[0043]

[Table 2]

[0044]

INDUSTRIAL APPLICABILITY In the 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 of the non-phosgene method, the melt polycondensation reaction is performed using an organosilicon compound. By carrying out the reaction in the presence of the compound (siloxane), an aromatic polycarbonate having improved heat resistance can be obtained although the concentration of hydroxyl groups at the molecular terminals of the obtained aromatic polycarbonate is not significantly reduced.

Claims (1)

[Claims] 1. An aromatic polycarbonate is produced by subjecting an aromatic diol compound and a carbonic acid diester compound to a melt polycondensation reaction in the presence of a transesterification catalyst and an organosilicon compound having a site represented by the following formula [I]. how to. [Chemical 1] [In the formula, R and R'each independently represent hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 2 to 10,000. ]