JPH0739479B2 - Method for producing polyester carbonate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyester carbonate. Specifically, it is a method of producing a polyester carbonate by subjecting a diaryl carbonate, an alkyl ester of an aromatic dicarboxylic acid and a dihydroxy aromatic compound to a transesterification reaction in a molten state in the presence of a catalyst.

(Prior art and its problems) As a method for producing a polyester carbonate (a)
A method of polymerizing a dihydroxy aromatic compound, a diaryl carbonate and an aromatic dicarboxylic acid in a molten state.
(B) A method of melt-polymerizing a dihydroxy aromatic compound, a diaryl carbonate, and a diaryl ester of an aromatic dicarboxylic acid is known. However, the method (a) is not economically advantageous because it is accompanied by a large amount of carbon dioxide gas, which has a low added value industrially, as shown in the formula (1), and is severe due to the slow reaction rate. Therefore, the resulting polymer is highly colored, and the method (b) is disadvantageous as an industrial method because it uses an expensive raw material such as a diaryl ester of an aromatic dicarboxylic acid. Is.

(Means for Solving the Problems) As a result of intensive studies to improve such drawbacks, the present invention shows that a high molecular weight polyester carbonate having excellent transparency can be obtained under relatively mild conditions by using a specific raw material monomer. The present invention has been completed by finding that it can be rapidly obtained below.

That is, in the present invention, a transesterification reaction of a diaryl carbonate and an aromatic dicarboxylic acid alkyl ester in the presence of a catalyst in a molten state is performed to obtain an aromatic dicarboxylic acid aryl ester, which is further purified to the reaction system without purification. This is a method for producing a polyester carbonate, which comprises adding a group compound and causing a transesterification reaction in a molten state.

That is, the present invention is a polyester carbonate characterized in that 1. transesterification reaction of diallyl carbonate and an aromatic dicarboxylic acid alkyl ester in a molten state in the presence of a catalyst, and then a dihydroxy aromatic compound is further added to cause a transesterification reaction. Manufacturing method.

2. The method for producing a polyester carbonate as described above, wherein the molar ratio of the carbonate component to the ester component of the polyester carbonate is 99: 1 to 1:99.

According to the present invention, as shown in the formula (2), a large amount of a carbonic acid dialkyl ester produced as a by-product as compared with the conventional method has a large industrial added value, and as shown in the formula (2), The reaction proceeds in a stepwise reaction via an aromatic dicarboxylic acid diaryl ester, which is a very advantageous method in productivity and economy as compared with the conventional method using an expensive aromatic dicarboxylic acid diaryl ester as a raw material monomer. .

Where R ₁ is R ₂ is ^{_{CnH 2 n + 1 - n =}} 1~6 R 3 an alkyl group of R ₄ is (Structure of the Invention) The dihydroxy aromatic compound used in the present invention is
2,2-bis (4'-hydroxyphenyl) propane [bisphenol A], 1,1-bis (4'-hydroxyphenyl) cyclohexane [bisphenol F], 1,1-bis (4'-hydroxy) Phenyl) ethane, bis (4-hydroxyphenyl) methane, 1,2-bis (4'-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl)
Cyclohexylmethane, 3,3'-bis (4'-hydroxyphenyl) pentane, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ether and the like can be mentioned. Of these, bisphenol A is mainly preferred.

Examples of the diaryl carbonate include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, dinaphthyl carbonate, bis (diphenyl) cabonate and the like. Primarily diphenyl carbonate is preferred.

As the aromatic dicarboxylic acid alkyl ester, terephthalic acid dialkyl ester, (as the alkyl group,
_{CH 3, -C 2 H 5,} -C 3 H 7, -C 4 H 9) as isophthalic acid dialkyl ester (the alkyl _{group, -CH 3, -C 2 H 5} , -C 3 H 7,
-C ₄ H ₉ ) and the like. Of these, terephthalic acid dimethyl ester and / or isophthalic acid dimethyl ester are mainly preferred.

In the present invention, a dihydroxy aromatic compound (X mol):
The theoretical molar ratio of diaryl carbonate (Y mole): aromatic dicarboxylic acid alkyl ester (Z mole) is X:
Y + Z: Z (where Y + Z = X) should give a high molecular weight polymer. However, as a result of various investigations in order to prevent the molar balance from being lost due to volatilization of the diaryl carbonate and to advance the reaction by obtaining an intermediate that is relatively stable against thermal decomposition, a slight excess of the diaryl carbonate over the theoretical amount was obtained. I need.

The order of addition of each component is preferably a method in which a diaryl carbonate and an alkyl ester of an aromatic dicarboxylic acid are subjected to a transesterification reaction in a molten state in the presence of a catalyst in advance, and then a dihydroxy aromatic compound is added and reacted.

As the catalyst used in the present invention, a catalyst generally used in transesterification reaction can be used. Examples of suitable catalysts are listed below.

(1) Alkali metals such as lithium, sodium, potassium, rubidium, cesium and francium, and carbonates, hydroxides, borohydrides, phenolates, bisphenolates, carboxylates and oxides of these alkali metals.

(2) Group II and Group III elements of the periodic table, for example, metals such as calcium, magnesium and aluminum, and carbonates, hydroxides, hydrides, borohydrides, phenolates and bisphenolates of these metals, Carboxylate,
Oxide.

(3) Metal oxides, metal acetates, titanium and tin compounds, for example, metal oxides such as antimony trioxide, germanium oxide, arsenic trioxide, lead oxide, magnesium oxide, zinc oxide, cobalt acetate, zinc acetate, cadmium acetate, Metal acetates such as manganese acetate, titanium compounds such as tetrabutyl titanate, tetraisopropyl titanate and tetraphenyl titanate, tin compounds such as dibutyltin oxide, dibutyltin methoxide, dibutyltin laurate and monoalkyl monohydroxytin oxide.

These catalysts are from about 0.00001 to 0.1 mol% based on an effective amount of the usual transesterification reaction of bisphenol, preferably 0.1.
001 mol% to 0.1 mol% is used.

In the method of the present invention, an appropriate amount of catalyst is added to the two components of diaryl carbonate and aromatic alkyl dicarboxylate, the system is completely replaced with nitrogen, and then the transesterification reaction is carried out. Thereafter, a dihydroxy aromatic compound is added, and the transesterification reaction is further advanced.

That is, the transesterification reaction is started from 150 ° C. to 180 ° C., and carbonic acid dialkyl ester and aromatic dicarboxylic acid aryl ester are produced. Gradually raise the temperature 20
The reaction is carried out at 0 ° C to 240 ° C for several hours (specifically, 1 to 5 hours). Then add the dihydroxy aromatic compound,
After cooling, the transesterification reaction is performed at 180 ° C to 220 ° C. Since aromatic monooxy compounds are generated, the temperature is gradually raised to 240 ° C to 260 ° C and the pressure of the reaction system is also increased.
The aromatic monooxy compound and the like produced by reducing the pressure to 60 mm Hg to 10 mm Hg are distilled off from the reaction system to complete the transesterification reaction and at the same time obtain an initial condensate.

Subsequently, the temperature is further raised and at the same time the reaction system is kept under high vacuum to proceed with the polycondensation reaction and finally to bring the reaction system to 270 ° C to 290 ° C.
A polymer having a high molecular weight is obtained by keeping it at several mm Hg or less, preferably 1 mm Hg or less.

The molar ratio of the carbonate component and the ester component of the polyester carbonate is 99: 1 to 1:99, preferably 9
5: 5 to 5:95 and more preferably 70:30 to 30:70.

In the method of the present invention, various additives such as a stabilizer (for example, an antioxidant, a heat stabilizer, an ultraviolet ray, an absorber, an anti-coloring agent) pigment may be added and mixed. According to the method of the present invention, in the production of a polycondensate, the polymerization reaction is promoted, and the transparency is excellent, and the release agent flame retardant that can be used for stabilizing the hue, stabilizing it against thermal hydrolysis and ultraviolet rays is used. Various additives such as agents can also be used.

Specific examples of this method will be described below.

(Example) Example 1 Dimethyl isophthalate was placed in a reactor equipped with a stirrer, which was replaced with nitrogen.
2.33 g (0.012 mol) and diphenyl carbonate 28.51 g
(0.133 mol) catalyst dibutyltin oxide (5 × 10 ^-2 mol% with respect to bisphenol A) was added and reacted at 240 ° C. for 3 hours. Then cool and bisphenol A27.3 at 200 ℃
Add 9g (0.12mol) and gradually raise the temperature over 3 hours
The temperature is raised to 260 ° C and the pressure in the reaction system is also lowered to 10 mm Hg to distill off the produced phenol. Continued 270 ° 1 hour 280 ° C 1
A polymer is obtained by reacting for 0.2 to 0.1 mm Hg for a time. The obtained polymer is a polymer with good transparency and little coloring.
5g / dl Methylene chloride Reduced specific viscosity ηs measured at 20 ℃
The p / C was 0.55. It was also confirmed by NMR that the molar ratio of the carbonate component to the ester component of the polyester carbonate was 90:10, which was the target.

Example 2 Dimethyl isophthalate was added to a reactor equipped with a stirrer that was replaced with nitrogen.
4.66 g (0.024 mol) and diphenyl carbonate 28.79 g
(0.134 mol) catalyst dibutyltin oxide (5 × 10 ^-2 mol% with respect to bisphenol A) was added and reacted at 260 ° C. for 3 hours. Then cool and bisphenol A27.3 at 200 ℃
9 g (0.12 mol) was added and the reaction was carried out as in Example 1. The obtained polymer had a reduced specific viscosity ηsp / C of 0.53. The molar ratio of the carbonate component to the ester component of the obtained polyester carbonate was 81:19.

Example 3 2.33 g (0.012 mol) of dimethyl terephthalate and 28.51 g of diphenyl carbonate were placed in a nitrogen-substituted reactor equipped with a stirrer.
((0.133 mol) catalyst monobutylmonohydroxytin oxide (2.5 × 10 ^-2 mol% relative to bisphenol A)
Was charged and reacted at 260 ° C. for 3 hours. Then, after cooling, 200.degree. C., 27.39 g (0.12 mol) of bisphenol A was added and Example 1
The reaction was performed in the same manner as in. Reduced specific viscosity η of the obtained polymer
The sp / C was 0.57. The molar ratio of the carbonate component to the ester component of the polyester carbonate was 90:10.

Example 4 Dimethyl terephthalate was added to a reactor equipped with a stirrer that was replaced with nitrogen.
2.33 g (0.012 mol), dimethyl isophthalate 2.33 g
(0.012 mol), diphenyl carbonate 28.79 g (0.134 mol)
Mol), catalyst dibutyltin oxide (bisphenol A
(2.5 × 10 ⁻² mol%) was added and the mixture was reacted at 260 ° C. for 3 hours. After cooling, at 200 ° C 27.39 g of bisphenol A (0.
12 mol) was added and the reaction was carried out in the same manner as in Example 1. The polymer obtained had a reduced specific viscosity ηsp / C of 0.55. The molar ratio of the carbonate component to the ester component of the obtained polyester carbonate was 81:19.

Comparative Example 1 Dimethyl isophthalate was added to a reactor equipped with a stirrer and replaced with nitrogen.
4.66 g (0.024 mol), diphenyl carbonate 28.79 g
(0.134 mol), bisphenol A (27.39 g, 0.12 mol) and catalyst dibutyltin oxide (5 × 10 ^-2 mol% based on bisphenol A) were added and polymerization was carried out under the same reaction conditions as in Example 2 to obtain The reduced specific viscosity ηsp / C of the polyester carbonate was 0.32. The molar ratio of the carbonate component to the ester component of the obtained polyester carbonate was 88:12, which was not the target 80:20.

Comparative Example 2 A reaction was conducted under the same conditions as in Example 2 except that 3.22 g (0.024 mol) of isophthalic acid was used instead of 4.66 g (0.024 mol) of dimethyl isophthalate, and the reduction ratio of the obtained polyester carbonate was obtained. The viscosity ηsp / C was 0.29. The molar ratio of the carbonate component to the ester component of the obtained polyester carbonate was 64:36 without the desired 80:20.

As is clear from other examples, the polyester carbonate obtained from this method has almost no deviation in the set molar ratio of the carbonate component and the ester component and a high molecular weight polyester carbonate is obtained, whereas in Comparative Examples, There is a large deviation in the molar ratio of and a high molecular weight polyester carbonate cannot be obtained.

(Effects of the Invention) Compared to the batchwise polymerization method of raw materials, (1) the purification of the intermediate product (aromatic digallic acid aryl ester) is not particularly required and the process is simplified. (2) Physical properties, such as molecular weight and composition ratio, are extremely stable and highly uniform.

The polyester carbonate obtained from the present method is used as a general engineering plastic material, for example, but it is particularly used for outdoor lighting equipment, window glass, outdoor applications such as fences, microwave oven dishes, tanks, transportation pipes, etc. or heat-sensitive materials. It is also applicable to flexible elements, various hoses, and tubes.

Claims (2)

[Claims] 1. A method for producing a polyester carbonate, characterized by transesterifying a diaryl carbonate and an aromatic dicarboxylic acid alkyl ester in a molten state in the presence of a catalyst, then adding a dihydroxy aromatic compound, and further carrying out a transesterification reaction. . 2. The method for producing a polyester carbonate according to claim 1, wherein the molar ratio of the carbonate component to the ester component of the polyester carbonate is 99: 1 to 1:99.