JPH085957B2 - Method for producing polycarbonate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a polycarbonate, and more specifically, in producing a polycarbonate by a transesterification reaction between a dihydric phenol and a monocarbonate, a reactor of a specific material is used. To efficiently produce a polycarbonate having an improved hue.

[Problems to be Solved by Prior Art and Invention]

Generally, phosgene method (interfacial polycondensation method) and melt transesterification method are known as methods for producing polycarbonate. However, the melt transesterification method is simple in process and advantageous in terms of cost, but has a drawback that the processing time at high temperature is long and the color of the product is deteriorated. As is well known, since polycarbonate is particularly characterized by its transparency, the phosgene method, which is relatively easy to obtain a colorless and transparent product, is predominant in the current industrial manufacturing process.

However, this phosgene method has problems such as using toxic phosgene and corrosion of equipment due to chlorine compounds generated by the reaction. In terms of process,
After washing the polycarbonate solution produced by polymerization,
It is necessary to sequentially perform the concentration step, the drying step, and the granulation step by each device. Especially, the burden of the concentration and drying steps is large, and large equipment such as a kneader or a dryer is required.
Since a large amount of equipment is required, there are problems in terms of equipment and operating costs.

Under such circumstances, it has been desired to develop a process capable of producing a polycarbonate having an excellent color tone on an industrial scale by the melt transesterification method, and various studies have been conventionally made.

For example, proposals have been made on a method of using a material produced in the highest possible purity as a raw material and a method of using a specific catalyst. However, although these methods provide almost colorless and transparent products in the laboratory, they are not a fundamental solution for industrially producing colorless and transparent polycarbonates.

[Means for solving the problem]

Therefore, the present inventors have solved the above-mentioned drawbacks of the prior art,
The inventors have conducted intensive studies to develop a production method capable of producing a polycarbonate having an excellent color tone on an industrial scale by the melt transesterification method.

As a result, they have found that the intended purpose can be achieved by using a reactor using a material containing copper or nickel as a main component. The present invention has been completed based on such findings.

That is, the present invention, when producing a polycarbonate by transesterification reaction of dihydric phenols and monocarbonate, the transesterification reaction, the material of the portion in contact with the reaction mixture, the content of copper and / or nickel is 85 It is intended to provide a method for producing a polycarbonate, which is carried out in a reactor made of a material made of a metal or an alloy whose content is at least wt%.

In the method of the present invention, as the dihydric phenol used as one of the raw materials, it is usually preferable to use bisphenol A, but as other dihydric phenols, for example, hydroquinone; 4,4'-dihydroxydiphenyl; bis (4-hydroxyphenyl) alkane; bis (4-hydroxyphenyl) cycloalkane; bis (4
-Hydroxyphenyl) sulfide; bis (4-hydroxyphenyl) sulfoxide; bis (4-hydroxyphenyl) sulfone; bis (4-hydroxyphenyl) ketone or 2,2-bis (3 ', 5'-dibromo-4'-
Mention may be made of halogenated bisphenols such as hydroxyphenyl) propane. Furthermore, trihydric or higher polyhydric phenols such as phloroglucin; phloroglucid and the like can be mixed and used. Any of these may be used alone or in combination of two or more.

As the monocarbonate, a dialkyl carbonate or a diaryl carbonate, and further an alkylaryl carbonate represented by the following general formula can be used.

(In the formula, R ¹ and R ² each represent an alkyl group having 1 to 10 carbon atoms. R ¹ and R ² may be the same or different.), (In the formula, Ar ¹ and Ar ² each represent an aryl group having 6 to 20 carbon atoms. Ar ¹ and Ar ² may be the same or different.), (In the formula, Ar represents an aryl group having 6 to 20 carbon atoms and R represents an alkyl group having 1 to 10 carbon atoms.) These alkylaryl diaryl carbonates represented by the general formulas (I) to (III) In the monocarbonate represented by, specific compounds preferably used include dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, diphenyl carbonate and the like.

In general, it is preferable that the dihydric phenol and the monocarbonate undergo a transesterification reaction in the presence of a polymerization catalyst in order to accelerate the polymerization rate.

The catalyst to be used is not particularly limited as long as it is a polycondensation catalyst which has been conventionally used in this kind of reaction, and various kinds can be used alone or in combination of two or more kinds.

Specifically, zinc fluoride, zinc chloride, zinc bromide, zinc iodide, cadmium fluoride, cadmium chloride, cadmium bromide, cadmium iodide, aluminum chloride, aluminum bromide, gallium fluoride, gallium chloride, fluorine Indium chloride, indium chloride, first germanium fluoride,
Germanium fluoride, germanium chloride, germanium chloride, stannous chloride, stannic chloride, stannic bromide, lead chloride, lead chloride, lead bromide, fluorinated 1st titanium, 1st titanium chloride, 2nd titanium chloride, 1st titanium bromide, zirconium fluoride, zirconium chloride,
Metal halides such as zirconium bromide; zinc carbonate, zinc nitrate, zinc sulfate, zinc phosphate, cadmium carbonate, cadmium nitrate, cadmium sulfate, cadmium phosphate, aluminum carbonate, aluminum nitrate, aluminum sulfate, gallium sulfate, indium carbonate, Inorganic nitrate, stannous sulfate, lead carbonate, lead nitrate, lead sulfate, lead sulfate, first titanium nitrate, first titanium sulfate, zirconium nitrate, zirconium sulfate and other metal inorganic acid salts; zinc oxide , Aluminum oxide, gallium oxide, indium oxide, germanium oxide, stannous oxide, stannic oxide
Metal oxides such as tin, lead (I) oxide, lead (II) oxide, lead (III) tetraoxide, titanium (III) oxide, titanium (II) oxide, and zirconium oxide; zinc hydroxide, cadmium hydroxide, aluminum hydroxide, gallium hydroxide , Germanium hydroxide, germanium hydroxide, stannous hydroxide, stannic hydroxide,
Metal hydroxides such as lead hydroxide; Zinc sulfide and other metal sulfides; AlNa (SO ₄ ) ₂ , Al (NH ₄ ) (SO ₄ ) _{2 and} other myoban anhydrides; Zn (OAc) ₂ , Zn (OBz) ₂ , Cd (OAc) ₂ , Cd (OBz) ₂ , Al (OAc) ₃ , Al
(OBz) ₃ ,, Ga (OAc) ₃ ,, Ga (OBz), GaO (OAc), Ga (OH) (OAc)
₂ , In (OAc) ₃ , Ge (OAc) ₄ , Ge (OBz) ₄ , Sn (OAc) ₂ , Sn (OAc) ₄ , Sn
(OBz) ₂ ,, Sn (OBz) ₄ ,, Pb (OAc) ₂ ,, Pb (OAc) ₄ ,, Pb (OBz), Zr (OA
c) Carboxylates of metals such as ₄ , Zr (OBz) ₄ , etc .; (NH ₄ ) ₂ [ZnCl ₄ ], [(CH ₃ ) ₄ N] ₂ , [ZnCl ₄ ], [Zn (en)
₃ ] X ₂ , [Zn (en)] X, K [CdCl ₃ ], [Cd (en) ₃ ] X ₂ , K ₂
[Cd (CN) ₄ ], Na ₃ [AlF ₆ ], (NH ₄ ) ₃ [AlF ₆ ], KGa (S
_{O 4) 2, (NH 4} ) [GaF 6], K [GeF 3], (NH 4) 2 [GeCl 6], N
_{a [SnF 3], [C} 2 H 5) 4 N] [SnCl 3], Ca [Sn (OAc) 2], K
₂ [PbCl ₆ ], Na [Pb (OH) ₆ , K ₂ [TiF ₆ ], (NH ₄ ) ₂ [TiC
l ₆ ], K ₂ [ZrF ₆ ], [(C ₂ H ₅ ) ₂ NH ₂ ] ₂ [ZrCl ₆ ], [ZrCl
₄ (CH ₃ CN) ₂ ] and other metal complex compounds; Zn (OC ₂ H ₅ ) ₂ , Zn (OPh) ₂ , Cd (OC ₂ H ₅ ) ₂ , Cd (OPh) ₂ ,, Al (OCH ₃ ).
₃ , Al (O ・ iC ₃ H ₇ ) ₃ , Al (OPh), Ga (OCH ₃ ) ₃ , Ga (Oph) ₃ , Ge (OC
H ₃ ) ₄ , Ge (OPh) ₄ , Sn (OCH ₃ ) ₂ , Sn (OH) ₃ , Sn (OC ₄ H ₉ ) ₄ , Sn (OP
h) ₂ , Sn (OPh) ₄ , (C ₄ H ₉ ) ₂ Sn (OCH ₃ ) ₂ , Pb (OCH ₃ ) ₄ , Pb (OPh) ₄ , (C ₄ H ₉ ) ₂ Pb (OPh) ₂ , Ti (OCH ₃ ) ₄ ; Ti (O
_{C 4 H 9) 4, Ti} (OPh) 4, Zr (OC 4 H 9) 4, Zr (OPh) of metal such as alkoxide or _{aryloxide; Zn (acac) 2, Zn} (oxin) 2, Cd (acac) ₂ , Cd (oxin) ₂ , Al (acac)
₃ , Al (oxin) ₃ , Ga (acac) ₃ , In (acac) ₃ , Ge (acac) ₂ Cl ₂ , SnCl ₂
Chelate compounds of metals such as (acac) ₂ , TiO (acac) ₂ , Zr (acac) ₄ ; (C ₂ H ₅ ) ₂ Zn, Ph ₂ Zn, C ₂ H ₅ as other organometallic compounds
ZnOC ₂ H ₅ ,, PhZnCl, PhZnOAc, C ₄ H ₉ ZnOAc, (C ₄ H ₉ ) ₂ CdPh ₂ Cd, Ph
CdCl, C ₄ H ₉ CdOAc, Ph ₃ Al, (CH ₃ ) ₃ Ga, Ph ₃ Ga (C ₂ H ₅ ) ₃ In, Ph ₃ I
n, Ph ₂ InCl, (C ₂ H ₅ ) ₄ Ge, Ph ₄ Ge, (C ₄ H ₉ ) ₂ GeX ₂ , Ph ₃ GeX, Ph ₂ Ge
X ₂ , [(C ₄ H ₉ ) ₂ GeO] _n・ [Ph ₂ GeO] _n , C ₂ H ₅ ) ₄ Sn, Ph ₄ Sn, (C
₄ H ₉ ) ₄ Pb, Ph ₄ Pb, (C ₂ H ₅ ) ₃ PbCl, Ph ₃ PbCl, (C ₂ H ₅ ) ₂ PbCl ₂ ,
₂ H ₅ ) ₃ Pb (OAc), (PhCH ₂ ) ₃ TiCl, (PhCH ₂ ) ₂ Ti (OC ₂ H ₅ ) ₂ , Ti
(Π‐C ₅ H ₅ ) ₂ , TiCl ₂ (π‐C ₅ H ₅ ) ₂ , Ti (CH ₃ ) ₂・ (π‐C _{5
H 5) 2, ZrCl (CH} 2 Ph) 3, Zr (C 4 H 9) 4, ZrCl 2 (CH 3) 2, [ZrCl
(Π-C ₅ H ₅ ) ₂ ] ₂ O, ZrCl ₂ (π-C ₅ H ₅ ), Zr (OAc) ₃ (π-C _{5
H 5) 2, (C 4} H 9) 2 SnCl 2, (C 4 H 9) 3 SnCl, (C 4 H 9) 2 SnO, [(C 4 H 9)
₂ SnO] _n・ [(C ₄ H ₉ ) ₂ SnO] _n , [(C ₈ H ₁₇ ) ₂ SnO] _n , [(C ₄ H ₉ ) P _h S _n
O], (C ₄ H ₉ ) ₂ Sn (OAc) ₂ , butyltin laurate and the like. In the above description, Ac is an acetyl group, Bz is a benzoyl group, en is ethylenediamine, Ph
Is a phenyl group, acac is acetylacetone, oxin is 8
-Quinolinol, π-C ₅ H ₅ represents a π-coordinated cyclopentadienyl group, and X represents a halogen atom, an alkoxy group or an aryloxy group.

Next, with reference to the drawings, a process for producing a polycarbonate by the melt transesterification method using the above-mentioned raw material and catalyst will be described.

FIG. 1 shows an example of a polycarbonate production process by the melt transesterification method, and is an example using two reactors, a first transesterification reactor 1 and a second transesterification reactor 2. Both reactors have heating jackets
3, stirrer 4 and extraction pump 5 are installed, and vacuum pipe 7 in which condenser 6 is arranged is connected.

First, the dihydric phenols and monocarbonates that are the raw materials are introduced into the first transesterification reactor 1 at the most efficient ratio at the temperature and pressure during the reaction described below. The mixing ratio of the two is preferably such that the monocarbonate is in a slight excess, and usually the monocarbonate is in a ratio of 1.05 to 20 mol per 1 mol of the dihydric phenol. The supply of the raw materials differs depending on whether the manufacturing process is a batch type or a continuous type, but either one or both may be added simultaneously in accordance with the progress of the reaction in the reactor. The amount of the catalyst is preferably in the range of 5 to 50,000 ppm by weight based on the dihydric phenol used. Further, the monomer desorbed from the reactor can be separated, purified and reused.

The reaction in both reactors can be performed by either a batch system or a continuous system. In the reaction, a substantially inert solvent can be used together with the above raw materials. The use of this solvent is mainly performed for the purpose of reducing the viscosity of the reaction product. When the solvent is used, the addition amount of the solvent is usually 1 to 95% by weight. If it is less than 1% by weight, it is difficult to lower the viscosity sufficiently, and if it exceeds 95% by weight, the cost of recovering the solvent after the reaction becomes large.

The temperature during the reaction is usually in the range of 100 to 350 ° C., but it is preferable to adopt a method of gradually increasing the temperature according to the progress of the reaction. If the reaction temperature is less than 100 ° C, the reaction proceeds slowly, and if it exceeds 350 ° C, the reaction product may be thermally deteriorated, which is not preferable. The pressure during the reaction is
It is set in consideration of the reaction temperature according to the vapor pressure of the raw material monomer used. Usually, a pressure of 1 to 50 atm is used in the initial stage of the reaction, and a reduced pressure state in the latter stage of the reaction, especially in the final stage.
It is preferably 0.01 to 100 Torr. Therefore, when the reaction is carried out continuously, it is preferable to use at least two or more reactors and set the reaction conditions for each. For example, as shown in FIG. 1, when using two reactors, the reaction conditions in the first transesterification reactor 1 should be a temperature of 50 to 280 ° C. and a pressure of 0.2 to 50 kg / cm ² abs. Is preferred. The reaction conditions in the second transesterification reactor 2 are as follows: temperature: 180-350 ° C, pressure: 0.01 Torr
It is preferably about ²⁰ kg / cm ² abs.

Further, in the present invention, the material of at least the portion in which the reaction mixture is substantially in contact in the reaction device for carrying out the transesterification reaction as described above, the content of copper and / or nickel is
It is necessary to use a metal or alloy of 85% by weight or more, preferably 90% by weight or more. That is, at least the portion that comes into contact with the reaction mixture is reacted using a reaction apparatus formed using pure copper, pure nickel, or an alloy containing 85% by weight or more of these. As other components of alloys containing copper and nickel other than pure metals, metals that are usually contained in order to have strength and workability,
For example, iron, chromium, zinc or the like can be used. Specific examples of the alloy include nickel 200 (98% by weight or more of nickel, 0.13% by weight of copper), Monel 400 (66% by weight of nickel, 31.5% by weight of copper, 1.35% by weight of iron), cupro nickel (30% by weight of nickel, Copper 69% by weight, iron 0.6% by weight),
Examples include red copper (86 wt% copper, 0.05 wt% iron, 14 wt% zinc). The portion formed of a metal or alloy having a composition of copper and / or nickel having a content of 85% by weight or more may be integrally formed of these metals or alloys, but plating, thermal spraying, sticking For example, even if a layer of these metals or alloys is formed on the surface thereof, the same effect can be obtained.

Here, when the material of the portion in contact with the reaction mixture of the reaction device (reactor) has a copper and / or nickel content of less than 85% by weight, the hue improvement which is the object of the present invention is sufficiently achieved. I can't.

The reaction apparatus used in the present invention can have the same configuration as various devices conventionally used for this type of reaction, and only the material of the portion in contact with the reaction mixture is changed. You can

Further, since the viscosity of the reaction mixture increases in the latter stage of the reaction, it is preferable to use a high-viscosity reactor having a stirring function as the second transesterification reactor 2. further,
An extruder type reactor can be used instead of a tank type reactor.

The vacuum pipe 7 in which the condenser 6 is arranged is for removing alcohols and phenols corresponding to the monocarbonate used as a raw material that is desorbed as the reaction progresses from the reactor. Alcohols, phenols and desorbed monomers are condensed and recovered. The reaction product, which has undergone the predetermined reaction in the first transesterification reactor 1, is extracted by the extraction pump 5 and then sent to the second transesterification reactor 2 to be reacted in the second transesterification reactor 2. The polymer produced after finishing can be granulated as it is, and can be subjected to various treatments with an extruder or the like.

〔Example〕

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 In a Monel 400 (Ni 66%, Cu 31.5%) autoclave (with a stirrer) having an internal volume of 3, 228 g of bisphenol A was added.
(1 mol), 592 g (5 mol) of diethyl carbonate and 1 g of tetrabutoxy titanium as a catalyst were charged and heated to 150 ° C. At the same time, stirring was started, and while maintaining the pressure of about 2 kg / cm ² , the produced ethanol and diethyl carbonate were extracted little by little. At the same time, diethyl carbonate was added at a rate of 450 g / hr, and the reaction was carried out for 8 hours while keeping the level in the autoclave constant.

Then stop adding diethyl carbonate,
The temperature was raised from 150 ° C. to 280 ° C. over 2 hours, and at the same time, the degree of vacuum was raised to remove residual diethyl carbonate and at the same time, the transesterification reaction was further advanced. Finally, the pressure was set to 8 torr and the reaction was continued for 15 minutes while stirring to obtain a viscous and transparent product in the autoclave.

The obtained substance was dissolved in methylene chloride and the viscosity average molecular weight was measured. Also,
This polymer was dissolved in methylene chloride to prepare a 5% solution, and the light transmittance was measured. At the same time, as a sample plate, a polycarbonate whose yellowness (YI) was already known was similarly used as a 5% solution, and the plate-corresponding YI was calculated from the light transmittance by interpolation, and it was 3.2, which is a highly transparent polycarbonate. It was found that

Example 2 The same operation as in Example 1 was carried out except that the catalyst was zinc acetate. As a result, a polymer having a molecular weight of 19,000 and a plate-equivalent YI3.5 was obtained.

Example 3 The same autoclave as in Example 1 was charged with bisphenol.
A228g (1 mol), diphenyl carbonate 235g (1.1 mol), and sodium hydroxide 1g as a catalyst were charged at 180 ℃.
Heated up. At the same time, stirring was started, nitrogen gas was filled, and the pressure was maintained at atmospheric pressure. The reaction was carried out for 1 hour as it was, and then the pressure was gradually reduced to extract the distilling phenol and diphenyl carbonate. Finally pressure
When the reaction was carried out at 0.5 Torr for 3 hours, a viscous and transparent substance was obtained in the autoclave.

The obtained substance was dissolved in methylene chloride and the viscosity average molecular weight was measured to be 26500. Also,
This polymer was dissolved in methylene chloride to prepare a 5% solution, and the light transmittance was measured. At the same time, as a sample plate, a polycarbonate whose yellowness (YI) was already known was similarly used as a 5% solution, and the plate-corresponding YI was calculated by interpolation from its light transmittance to find that it was 2.3, which is a highly transparent polycarbonate. It was found that

Examples 4 to 6 and Comparative Examples 1 to 4 were changed to those shown in Table 1 of the material of the autoclave,
The procedure of Example 1 or 2 was repeated, except that the catalyst was changed. The results are shown in Table 1.

[Effects of the Invention] As described above, according to the present invention, it is possible to reduce the deterioration of hue in the process of producing a polycarbonate by the melt transesterification method, and it is possible to sufficiently exhibit the transparency which is a characteristic of the polycarbonate. it can. Furthermore, since the melt transesterification method, which is simple in process, is adopted, polycarbonate can be produced at low cost.

Further, since the device used in the present invention uses a material that is relatively easy to obtain, it is easy to manufacture and can be manufactured at low cost. Furthermore, it has a good thermal conductivity and is suitable for heat treatment.

The present invention is not limited to the above-mentioned polycarbonate, but can be applied to the case of producing a polymer such as polyester, polysulfonate, polyamide, polyphenylene oxide.

Therefore, the present invention can be effectively and widely used in the production of high-quality polycarbonate and also in the production of other polymers.

[Brief description of drawings]

FIG. 1 is a system diagram showing an example of a polycarbonate production process by the melt transesterification method. 1: First transesterification reactor 2: Second transesterification reactor 3: Heating jacket, 4: Stirrer 5: Extraction pump, 6: Condenser 7: Vacuum piping

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Kurosawa, Ichihara-shi, Chiba Prefecture, 1 Anesaki Kaigan 1 Idemitsu Petrochemical Co., Ltd. (56) References Japanese Patent Laid-Open No. 55-142025

Claims (2)

[Claims] 1. When producing a polycarbonate by a transesterification reaction between a dihydric phenol and a monocarbonate, the material of the portion in contact with the reaction mixture in the transesterification reaction has a copper and / or nickel content of 85. A method for producing a polycarbonate, which is carried out in a reactor made of a material made of a metal or an alloy whose content is at least wt%. 2. The method for producing a polycarbonate according to claim 1, wherein the monocarbonate is a dialkyl carbonate or a diaryl carbonate.