JP2002069169A - Aromatic polycarbonate having melt fluidity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aromatic polycarbonate excellent in color tone. SOLUTION: This aromatic polycarbonate having melt fluidity is produced by reacting an aromatic dihydroxy compound with a dicarbonate in heat-melting, wherein a viscosity-average molecular weight is 6,000 or above and 22,000 or below, the crystal melting point Tm( deg.C) is <=320 deg.C, and fluidity appears at the heating temperature T( deg.C) satisfying 0<=Tm-T<=70 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a melt-flowable aromatic polycarbonate.

[0002]

2. Description of the Related Art Polycarbonate resins obtained from the interfacial polycondensation of bisphenol A and phosgene are widely used for various purposes due to their excellent mechanical and thermal properties. However, polycarbonate is essentially used. A homogeneous solution of an organic solvent such as methylene chloride. Furthermore, there is a problem in safety by using toxic phosgene, and there are many problems such as chlorine ions remaining in polycarbonate produced by using methylene chloride as a solvent.

In the transesterification method, in order to increase the reaction rate, melt polymerization of a homogeneous melt is carried out under high vacuum conditions and as high temperature conditions as possible. Since the polycarbonate resin obtained by such a method is subjected to a heat history at a high temperature, a resin excellent in quality such as deterioration of hue could not be obtained.

Therefore, a solid-state polymerization method has been proposed in which a transesterification method is used to produce a polycarbonate having a relatively low heat history and excellent in hue. However, in solid-phase polymerization, the polycarbonate oligomer, which is the starting material, is crystallized in advance, and the crystallized oligomer is heated, and transesterification is performed in the solid state to increase the molecular weight. In some cases, due to frictional heat generated inside the apparatus, the molded product may take on a yellow tint and have a poor hue.

[0005] Further, as shown in Japanese Patent Application Laid-Open No. 3-68627, the production cost of the obtained polycarbonate is not advantageous as an industrial process such as using a crystallization solvent because the reaction apparatus is complicated in the solid phase polymerization method. .

[0006]

An object of the present invention is to provide a melt-flowable aromatic polycarbonate having a partially crystallized state, that is, a melt-flowable aromatic polycarbonate. More specifically, an object of the present invention is to provide an aromatic polycarbonate having an excellent color tone.

[0007]

According to the present invention, there is provided the following formula (I):
Aromatic dihydroxy compound represented by

[0008]

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In the formula, X is

[0010]

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Here, R ₁ and R ₂ are the same or different and are a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ₃ is a divalent hydrocarbon group having 4 to 20 carbon atoms. R ₄ and R ₅ are the same or different and are a halogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms;
Are the same or different and represent 0 or an integer of 1 to 4.
And at least one carbonic acid diester selected from the group consisting of diaryl carbonate and dialkyl carbonate, which is produced by reacting under heating and melting, having a viscosity average molecular weight of 6000 or more and 22,000 or less, and a crystal melting point Tm (° C.) determined by a differential scanning calorimeter. ≤320 ° C and 0≤Tm-T
It is a melt-flowable aromatic polycarbonate that exhibits fluidity at a heating temperature T (° C) satisfying ≦ 70 ° C.

Further, it is produced by reacting an aromatic dihydroxy compound represented by the above formula (I) with at least one carbonic diester selected from the group consisting of diaryl carbonate and dialkyl carbonate under heat and melting, and has a viscosity average molecular weight. Is 6000 or more and 22000 or less,
It is a melt-flowable aromatic polycarbonate having a crystal melting point Tm (° C.) ≦ 320 ° C. by a differential scanning calorimeter and exhibiting fluidity at a heating temperature T (° C.) satisfying 0 ≦ Tm−T ≦ 56 ° C.

Further, it is produced by reacting an aromatic dihydroxy compound represented by the above formula (I) with at least one carbonic diester selected from the group consisting of diaryl carbonates and dialkyl carbonates while heating and melting, and has a viscosity average molecular weight. Is 6000 or more and 22000 or less,
It is a melt-flowable aromatic polycarbonate having a crystal melting point Tm (° C.) ≦ 320 ° C. by a differential scanning calorimeter and exhibiting fluidity at a heating temperature T (° C.) satisfying 0 ≦ Tm−T ≦ 25 ° C.

The present inventors have conducted intensive studies to find a polycarbonate resin having an excellent hue by a transesterification method. As a result, it has been found that it is effective to carry out the polymerization of a polycarbonate oligomer in a molten state containing crystals, and it has been found that a melt-flowable aromatic resin is effective. A group polycarbonate was obtained.

The aromatic polycarbonate of the present invention is obtained by reacting an aromatic dihydroxy compound and a carbonic acid diester under heat and melting, a. A mixture of an aromatic dihydroxy compound and a carbonic acid diester was heated at a temperature of 160 to 200 ° C. and a pressure of 100 to 30 mmH.
g (indicating mmHg abs.) to produce a low polymer having a viscosity average molecular weight of 1500 to 4000, b. Heated at a temperature of 200 to 210 ° C. and a pressure of 1 mmHg or less, the viscosity average molecular weight is 6,000 to 10,000, and
Producing a polymer having a crystalline melting point of at least 240 ° C., and c. The polymer was heated at a temperature of 210 to 220 ° C. and a pressure of 1 mmHg or less to reduce the viscosity average molecular weight of the polymer to 10,000 to 12,000.
And d. Polymerization is further carried out at 240 ° C or higher, and the crystal melting point is 32.
It can be obtained by producing an aromatic polycarbonate having a temperature of 0 ° C. or lower.

The aromatic dihydroxy compound that can be used in the present invention includes a compound represented by the following formula (I).

[0017]

Embedded image

In the formula, X is

[0019]

Embedded image It is.

Here, R ₁ and R ₂ are the same or different and are a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 12 carbon atoms. As the hydrocarbon group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms is preferable. Examples of such an aliphatic hydrocarbon group include an alkyl group and an alkenyl group, and examples include a methyl group, an ethyl group, and a propyl group. Examples of the aromatic hydrocarbon group include a substituted or unsubstituted phenyl group and a naphthyl group. Examples of the halogen atom include chlorine, bromine and iodine.

R ₃ is a divalent hydrocarbon group having 4 to 20 carbon atoms, and examples thereof include aliphatic hydrocarbon groups such as an alkylene group and an alkenylene group, such as a butylene group and a pentylene group.

In the formula, R ₄ and R ₅ are the same or different and are a halogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples of the hydrocarbon group include an aliphatic hydrocarbon group having 1 to 12 carbon atoms and an aromatic group having 6 to 12 carbon atoms. Examples of the aliphatic hydrocarbon group include an alkyl group and an alkenyl group, and more specifically, a methyl group, an ethyl group, and a propyl group. Examples of the aromatic group include a substituted or unsubstituted phenyl group and a naphthyl group. Examples of the halogen atom include chlorine, bromine, iodine and the like.

In the formula, m and n are the same or different and represent 0 or an integer of 1 to 4.

As such an aromatic dihydroxy compound,
Bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane,
4,4-bis (4-hydroxyphenyl) heptane,
2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,
5-dibromophenyl) propane, bis (4-hydroxyphenyl oxide), bis (3,5-dichloro-4)
-Hydroxyphenyl) oxide, p, p'-dihydroxydiphenyl, 3,3'-dichloro-4,4'-dihydroxyphenyl, bis (4-hydroxyphenyl)
Sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, dihydroxybenzene, resorcinol, hydroquinone, 1,4-dihydroxy-2,5
-Dichlorobenzene, 1,4-dihydroxy-3-methylbenzene, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide, etc., and especially 2,2-bis (4-hydroxyphenyl) Propane is preferred.

As the carbonic diester used as a raw material, diaryl carbonates such as diphenyl carbonate, dinaphthyl carbonate and bis (diphenyl) carbonate and dialkyl carbonates such as dimethyl carbonate, diethyl carbonate and dibutyl carbonate are used. Of these, diphenyl carbonate is particularly preferred.

The reaction is carried out by heating and stirring the aromatic dihydroxy compound and the carbonic acid diester under an inert gas atmosphere to distill off the produced alcohol or phenol.

A polymerization catalyst can be used to increase the polymerization rate. As the polymerization catalyst, alkali metals such as sodium hydroxide and potassium hydroxide, hydroxides of alkaline earth metals, alkali metal salts of hydroxides of boron and aluminum, alkaline earth metal salts, quaternary ammonium salts, Alkoxides of alkali metals or alkaline earth metals, organic acid salts of alkali metals or alkaline earth metals, zinc compounds, boron compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, onium compounds Catalysts commonly used for esterification and transesterification such as antimony compounds, manganese compounds, titanium compounds, and zirconium compounds can be used, but are not limited thereto.

When a catalyst is used, only one type may be used or two or more types may be used in combination. These catalysts are used in an amount of 0.0001 to 1% by weight, preferably 0.0005 to 1% by weight, based on the aromatic dihydroxy compound used as the raw material.
0.5 wt%, more preferably in the range of 0.001 to 0.1 wt%. The feature of the above-mentioned production method is to increase the degree of polymerization by reacting a low polymer produced initially in the transesterification reaction at a temperature higher than the temperature at which fluidity is exhibited and at a temperature lower than the temperature at which crystals disappear.

That is, the above-mentioned production method comprises the following a to d
Is carried out according to the steps of

A. Formation of Low Polymer A step of heating a mixture of an aromatic dihydroxy compound and a carbonic acid diester at a temperature of 160 to 200 ° C and a pressure of 100 to 30 mmHg to obtain a polymer having a viscosity average molecular weight of 1500 to 4000.

B. Crystallization This step is a step of continuing the reaction while precipitating partially the crystals in the molten state of the low polymer produced in the above steps. As the crystallization progresses, the low polymer becomes cloudy and maintains fluidity, so it can be confirmed that the low polymer is partially crystallized. In order to simultaneously perform polymerization and crystallization of this low polymer, crystallization does not occur at a high reaction temperature.
C., and the degree of reduced pressure is preferably 1 mmHg or less. In this step, the reaction is performed until the polymer has a viscosity average molecular weight of 6,000 to 10,000 and a crystal melting point of 240 ° C. or higher.

C. Improvement of the degree of polymerization The partially polymerized low-polymerized product can be maintained at a temperature within a range in which the fluidity and the partially crystalline state can be maintained, preferably 210 to 210.
This is a step of increasing the degree of polymerization by heating at 220 ° C. under a pressure of 1 mmHg. In this step, the reaction is carried out until the viscosity average molecular weight of the polymer becomes 10,000 to 12,000.

D. Heating and heating Further, the temperature is raised to 240 ° C. or higher and polymerization is carried out to obtain an aromatic polycarbonate having a crystal melting point of 320 ° C. or lower. Heating is performed in stages, the upper limit of the temperature is 3
It is about 00 ° C.

The polycarbonate resin thus obtained can be pelletized by an extruder.

The partially crystalline state at the time of the polymerization is a state having a crystal melting peak on a differential scanning calorimeter and maintaining a fluid state as a whole having fluidity.
In other words, it is a state that exhibits melt fluidity while exhibiting crystallinity. The polycarbonate of the present invention has a melt fluidity at a temperature lower than the crystal melting peak of the differential scanning calorimeter, and has a very excellent color tone.

[0036]

The aromatic polycarbonate of the present invention has a partially crystallized state and is excellent in color tone.

[0037]

The present invention will be described below with reference to examples and comparative examples. In the Examples and Comparative Examples,% and parts are by weight unless otherwise specified.
Or parts by weight. The viscosity average molecular weight is 0.7 g / dl
Was measured for intrinsic viscosity using a Ubbelohde viscometer, and the viscosity average molecular weight was determined by the following equation. [Η] = 1.23 × 10 ⁻⁴ M ^{0.83 The} total light transmittance was measured by Nippon Denshoku # 80 in accordance with ASTM D1003. Yellowness YI is JIS
Nippon Denshoku ND-1001 based on K7103-77
It was measured by DP. The crystal melting point was measured by a DSC method (differential scanning calorimeter).

[0038]

EXAMPLE 1 137 g of 2,2-bis (4-hydroxyphenyl) propane and 135 g of diphenyl carbonate were placed in a 500 ml stainless steel reactor equipped with a stirrer and a distillation column.
g, bisphenol A disodium salt 1.6 as a catalyst
mg was charged and replaced with nitrogen. 160 ° C
And dissolved with stirring. Then, the pressure was reduced to 30 mmHg and the mixture was heated to 200 ° C., and most of the phenol was distilled off in one hour. In this state, no crystals were present, and the viscosity average molecular weight was 1,800.

Next, when the reaction was continued for 1 hour at a reduced pressure of 1 mmHg or less, the contents became cloudy while maintaining a fluid state, and were partially crystallized. At this time, the viscosity average molecular weight was 7,700, and the crystal melting point was 256 ° C.

Subsequently, while maintaining the degree of vacuum at 1 mmHg,
The temperature was raised to 20 ° C., and the reaction was performed for 0.5 hour. At this time, the viscosity average molecular weight was 11,400.

Subsequently, when the temperature was raised to 240 ° C. and the reaction was carried out for 1 hour, the viscosity-average molecular weight was 1 while maintaining a partially crystallized state.
At 5200, a polycarbonate having a crystalline melting point of 310 ° C. was obtained.

The pellet was extruded at a temperature of 320 ° C.
Injection molding was performed on a test piece having a diameter of 0 mm and a thickness of 3 mm. This had a total light transmittance of 90% and a YI of 1.6.

[0043]

Example 2 In the same manner as in Example 1, each raw material was dissolved, and then the pressure was reduced to 30 mmHg, and the mixture was heated to 200 ° C and most of the phenol was distilled off in 1 hour. In this state, no crystals were present, and the viscosity average molecular weight was 1,800.

Next, when the reaction was continued for 1 hour at a reduced pressure of 1 mmHg or less, the contents became cloudy while maintaining the fluid state, and became partially crystalline. At this time, the viscosity average molecular weight was 7,700, and the crystal melting point was 256 ° C.

Subsequently, while maintaining the degree of vacuum at 1 mmHg,
When the temperature was raised to 20 ° C. and the reaction was performed for 0.5 hour, the viscosity average molecular weight was raised to 11400, then the temperature was raised to 240 ° C. and the reaction was performed for 1 hour, and then the temperature was raised to 290 ° C. and the reaction was performed for 1 hour. A polycarbonate resin having a viscosity average molecular weight of 22,000 and a crystal melting point of 315 ° C. was obtained while partially maintaining the crystallized state.

Heat flow rate (DSC) of this polycarbonate
The chart is shown in FIG. The pellets were extruded at a temperature of 340 ° C. and injection-molded into test pieces having a diameter of 40 mm and a thickness of 3 mm. This had a total light transmittance of 90% and a YI of 2.9.

The viscosity average molecular weight and the crystal melting point Tm of the aromatic polycarbonate obtained in Example 1 and Example 1
(° C.) and the relationship between the heating temperature T (° C.) are summarized in Table 1 below.

[0048]

[Table 1]

[0049]

Comparative Example 1 Each raw material was dissolved in the same manner as in Example 1, then heated to 200 ° C. at a reduced pressure of 30 mmHg, and most of the phenol was distilled off in 2 hours. Next, the degree of pressure reduction is 30 mm
The temperature was raised to 290 ° C. while maintaining the Hg, and then the reaction was carried out at a reduced pressure of 1 mmHg for 0.5 hour to obtain a polycarbonate resin having a viscosity average molecular weight of 22,500. The obtained polycarbonate was not cloudy. The pellets were extruded at a temperature of 320 ° C. and injection molded into test pieces having a diameter of 40 mm and a thickness of 3 mm. This had a total light transmittance of 90% and a YI of 4.5.

[Brief description of the drawings]

FIG. 1 is a DSC of the polycarbonate obtained in Example 2.
The chart is shown.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Katsuji Sasaki 2-1 Hinode-cho, Iwakuni-shi, Yamaguchi Prefecture F-term in the Iwakuni Research Center, Teijin Limited 4J029 AA09 AB04 AD01 AD06 BB04A BB04B BB05A BB06C BB10A BB12A BB13A BF14A BG08X BG09X BG24X BH02 DB07 DB11 HC04 HC05 KC01 KD01 KD05 KE02 KE05

Claims (3)

[Claims] An aromatic dihydroxy compound represented by the following formula (I): In the formula, X is Here, R ₁ and R ₂ are the same or different and are a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 12 carbon atoms.
₃ is a divalent hydrocarbon group having 4 to 20 carbon atoms, R _4,
R ₅ is the same or different and has a halogen atom or carbon number 1
To 12 are monovalent hydrocarbon groups, m and n are the same or different, and represent 0 or an integer of 1 to 4. And at least one type of carbonic acid diester selected from the group consisting of diaryl carbonate and dialkyl carbonate, which is produced by reacting under heating and melting, and having a viscosity average molecular weight of 6000.
Above 22,000, the crystal melting point T was determined by differential scanning calorimetry.
A melt-flowable aromatic polycarbonate having a m (° C.) ≦ 320 ° C. and a fluidity at a heating temperature T (° C.) satisfying 0 ≦ Tm−T ≦ 70 ° C. 2. An aromatic dihydroxy compound represented by the following formula (I): In the formula, X is Here, R ₁ and R ₂ are the same or different and are a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 12 carbon atoms.
₃ is a divalent hydrocarbon group having 4 to 20 carbon atoms, R _4,
R ₅ is the same or different and has a halogen atom or carbon number 1
To 12 are monovalent hydrocarbon groups, m and n are the same or different, and represent 0 or an integer of 1 to 4. And at least one type of carbonic acid diester selected from the group consisting of diaryl carbonate and dialkyl carbonate, which is produced by reacting under heating and melting, and having a viscosity average molecular weight of 6000.
Above 22,000, the crystal melting point T was determined by differential scanning calorimetry.
A melt-flowable aromatic polycarbonate having a m (° C.) ≦ 320 ° C. and exhibiting fluidity at a heating temperature T (° C.) satisfying 0 ≦ Tm−T ≦ 56 ° C. 3. An aromatic dihydroxy compound represented by the following formula (I): In the formula, X is Here, R ₁ and R ₂ are the same or different and are a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 12 carbon atoms.
₃ is a divalent hydrocarbon group having 4 to 20 carbon atoms, R _4,
R ₅ is the same or different and has a halogen atom or carbon number 1
To 12 are monovalent hydrocarbon groups, m and n are the same or different, and represent 0 or an integer of 1 to 4. And at least one type of carbonic acid diester selected from the group consisting of diaryl carbonate and dialkyl carbonate, which is produced by reacting under heating and melting, and having a viscosity average molecular weight of 6000.
Above 22,000, the crystal melting point T was determined by differential scanning calorimetry.
A melt-flowable aromatic polycarbonate having a m (° C.) ≦ 320 ° C. and a fluidity at a heating temperature T (° C.) satisfying 0 ≦ Tm−T ≦ 25 ° C.