JP3352997B2 - Method for producing aromatic polyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an aromatic polyester. More specifically, dicarboxylic acids,
The present invention relates to a method for producing an aromatic polyester excellent in color tone from a diol and a diaryl carbonate.

[0002]

2. Description of the Related Art In recent years, performance requirements for engineering plastics having high heat resistance and excellent mechanical strength have been increasing. Amorphous engineering plastics include polyarylate and aromatic polyester carbonate, which are aromatic polyesters derived from aromatic diols and aromatic dicarboxylic acids. For example, as an aromatic diol, 2,2
-Bis (4-hydroxyphenyl) propane (hereinafter abbreviated as bisphenol A), polyarylate composed of terephthalic acid and isophthalic acid as aromatic dicarboxylic acids,
It has relatively balanced properties and is used for various purposes.

[0003] Various studies have been made on the method for producing these amorphous aromatic polyesters. Among them, an interfacial polycondensation method between an acid halide of an aromatic dicarboxylic acid and an aromatic diol has been industrialized. . However, methylene chloride, which is usually used as a reaction solvent in this interfacial polycondensation method, is a chemical substance having environmental and sanitary problems, and its handling requires careful attention. Due to the extremely low temperature of 0 ° C., it is difficult and expensive to obtain a closed system in which methylene chloride used in the production of the aromatic polyester can be completely recycled.

Similarly, when an aromatic polyester carbonate is produced from an acid halide of an aromatic dicarboxylic acid, an aromatic diol, and phosgene by an interfacial polymerization method, a similar problem occurs. Therefore, a melt polymerization method of these polymers is being studied.

[0005] However, it is not practical to obtain these polymers by direct melt polymerization using dicarboxylic acids and diols, because the coloring is severe and the polymerization rate is low. Therefore, in practice, the method (1) in which a diaryl ester of a dicarboxylic acid component is reacted with a diol in advance, the method (2) in which a dicarboxylic acid is reacted with a lower aliphatic carboxylic acid ester of a diol, and the method (2) are different methods. The method (3) of adding a lower aliphatic carboxylic acid anhydride when reacting a dicarboxylic acid and a diol is used. However, in the methods (1) and (2), the raw materials have to be esterified in advance, which causes an increase in cost. In the methods (2) and (3), the lower aliphatic carboxylic acid is generated during the reaction, so that the apparatus is easily corroded, and the obtained polymer has a problem that the terminal COOH concentration is large.

As a method for solving such a problem,
There is a method of reacting an aromatic dicarboxylic acid with an aromatic diol or diaryl carbonate. However, even with this method, it was difficult to obtain a polymer having an excellent hue. As a method of improving hue, for example, Japanese Patent Publication No. 3-12892
JP-A No. 6 reports on a method for producing an aromatic polyester by reacting an aromatic dicarboxylic acid with an aromatic diol or a diaryl carbonate using a borane-tertiary amine complex salt compound and / or a quaternary ammonium borohydride compound as a catalyst. Have been. Also, Japanese Patent Application Laid-Open No. Hei 4-23
Japanese Patent No. 6224 reports a method for producing an aromatic polyester using a specific tin compound as a catalyst.

However, aromatic dicarboxylic acids generally have low solubility, and dissolution of the dicarboxylic acid component is rate-determining.
The reaction must be carried out at a high temperature, and may require a long time, so that there is a limit in improving the hue. In addition, in the conventional melt polymerization method, a sublimate is generated during the polymerization reaction,
Due to their removal, the production process becomes complicated, the equipment becomes large, and as a result, the cost increases.

[0008]

Therefore, the present invention provides an aromatic polyester having excellent heat resistance and mechanical properties by a melt polymerization method directly from a dicarboxylic acid and a diol without esterifying the dicarboxylic acid or the diol in advance. It is an object of the present invention to provide a method which is excellent in hue and industrially manufactured at low cost.

[0009]

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

[0010]

Embedded image ^{HOOC-A 1 -COOH ... (I} ) (A 1 of the formula (I) is which may be substituted aromatic group.) A dicarboxylic acid component represented by (a) and the following formula ( II)

[0011]

Embedded image HO—A ² —X—A ³ —OH (II) (A ² and A ³ in the formula (II) are each a phenylene group which may be substituted. X is

[0012]

Embedded image

[0013]

R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 or 6 carbon atoms, It is selected from an aryl group and an aralkyl group having 6 to 12 carbon atoms. q shows the integer of 4-10. A) a diaryl carbonate (c) with the diol component (b)
In producing an aromatic polyester by a heat-melting reaction in the presence of

[0015]

Embedded image

(R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, and
2 aralkyl groups. Further, there may be a bond between R ⁵ and R ⁶ . R ⁷ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, 5 or 6 carbon atoms.
, An aryl group having 6 to 12 carbon atoms and an aralkyl group having 6 to 12 carbon atoms. n is 1
Shows an integer of ~ 4. ) In the presence (but without the presence of an antimony compound), the following formulas ( 2) , (3) and (4)

[0017]

0.8 ≦ (A + B) /C≦1.2 (2) 0.95 ≦ A / B ≦ 1.05 (3) 1.8 ≦ C / A ≦ 2. 2 (4) (where A is the dicarboxylic acid component (a), B is the diol component (b), and C is the number of moles of the diaryl carbonate (c)) at the same time. Characteristic viscosity ( measured in a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40) at 35 ° C.) characterized by performing the reaction using It is a method for producing an aromatic polyester having the same.

Hereinafter, the present invention will be described in detail.

The dicarboxylic acid component (a) used in the present invention is represented by the following formula (I).

[0020]

Embedded image ^{HOOC-A 1 -COOH ··· (I} ) (A 1 of the formula (I) may be substituted is an aromatic group.) Aromatic groups in the above formula (I) A group having a phenylene group, a naphthylene group, or a phenyl group or a naphthyl group.

The dicarboxylic acid component (a) used in the present invention represented by the above formula (I) includes, for example, terephthalic acid, isophthalic acid, methyl terephthalic acid, methyl isophthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene -2,7-dicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylsulfonedicarboxylic acid, phenylindanedicarboxylic acid, and the like. These aromatic dicarboxylic acids may be used alone or in combination. In particular, it is preferable to use terephthalic acid and isophthalic acid simultaneously.

The diol component (b) used in the present invention is represented by the following formula (II).

[0023]

Embedded image HO—A ² —X—A ³ —OH (II) In the above formula (II), A ² and A ³ are each a phenylene group which may be substituted. X is

[0024]

Embedded image

Wherein R ¹ and R ² are each independently a hydrogen atom, a halogen atom such as chlorine or bromine, an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group or a propyl group, a cyclopentyl group or a cyclohexyl group. And the like, such as a cycloalkyl group having 5 or 6 carbon atoms, or a phenyl group, etc.
It is selected from 12 aryl groups or aralkyl groups.
Or

[0026]

Embedded image Wherein R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, 5 or 6 carbon atoms,
, An aryl group having 6 to 12 carbon atoms and an araalkyl group having 6 to 12 carbon atoms. q
Represents an integer of 4 to 10. ) Such diol component (b) includes 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3,5-dimethyl- 4-Hydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (3,5-dichloro-4-hydroxyphenyl) propane and the like are exemplified, and among these, 2,2-bis (4-hydroxyphenyl) propane,
1,1-bis (4-hydroxyphenyl) cyclohexane is preferred. These diol components may be used in combination of two or more.

The diaryl carbonate (c) includes
For example, diphenyl carbonate, di-p-tolyl carbonate, dinaphthyl carbonate, di-p-chlorophenyl carbonate, phenyl-p-tolyl carbonate and the like can be mentioned. Of these, diphenyl carbonate is particularly preferred. The diaryl carbonate may be substituted, used alone or in combination of two or more.

According to the present invention, the compound (a)
(B) and (c) are expressed by the following formulas (3) and (2).

[0029]

0.95 ≦ A / B ≦ 1.05 (3) 0.8 ≦ (A + B) /C≦1.2 (2) (where A is a dicarboxylic acid component (a), and B is a diol) The components (b) and C are the number of moles of the diaryl carbonate (c)), respectively. Here, the above formula (3) is a dicarboxylic acid component (a)
And the molar ratio of the diol component (b). This ratio A
When / B is close to 1, specifically, 0.95 ≦ A / B ≦
When it is 1.05, the obtained polymer is substantially the following formula (IV)

[0030]

Embedded image (Formula (in IV), A ¹ is the same .A ² to A ¹ in the formula (I),
A ³ and X are the same as A ² , A ³ and X in the formula (II). ) Is obtained.

On the other hand, the above formula (2) represents the molar ratio of the sum of the dicarboxylic acid component (a) and the diol component (b) to the diaryl carbonate (c). This ratio (A +
If B) / C is less than 0.8, polymerization of the resulting polymer will be slow. On the other hand, if it is larger than 1.2, coloring of the obtained polymer becomes intense. In the formula (2), preferably 0.9 ≦ (A + B) /C≦1.15.

In the production method of the present invention, the above compounds (a), (b) and (c) are represented by the following two relational formulas.

[0033]

0.95 ≦ A / B ≦ 1.05 (3) 1.8 ≦ C / A ≦ 2.2 (4) (where A is a dicarboxylic acid component (a) , B is a diol component (b) and C is the number of moles of the diaryl carbonate (c)) at the same time to produce an aromatic polyester. The above formula (3) is necessary because the ratio of the dicarboxylic acid component to the diol component in the finally obtained polymer becomes substantially 1. If the molar ratio (C / A) of the dicarboxylic acid component (a) to the diaryl carbonate (c) is less than 1.8, the polymerization will be slow. On the other hand, if it is larger than 2.2, coloring of the obtained polymer becomes intense . Good Mashiku is 1.85 ≦ A / B ≦
2.15.

In the method of the present invention, the compound (a)
(B) and (c) are heated and melted in the presence of a compound represented by the following formula (III).

[0035]

Embedded image

In the formula (III), R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group, or a carbon atom having 5 to 10 carbon atoms such as a cyclopentyl group or a cyclohexyl group. And an aralkyl group having 6 to 12 carbon atoms such as a benzyl group and the like, and an aryl group having 6 to 12 carbon atoms such as a cycloalkyl group, a phenyl group and a naphthyl group. Also, R ⁵
And R ⁶ may have a bond. R ⁷ is of the formula (I
Is the same as R ¹ I). n shows the integer of 1-4. Of these, R ⁵ and R ⁶ are an alkyl group and / or R ⁵ and R ⁶
And R ⁷ is preferably a hydrogen atom.

As the compound represented by the above formula (III), for example, 4-aminopyridine, 4-dimethylaminopyridine, 4-diethylaminopyridine, 4-pyrrolidinopyridine, 4-piperidinopyridine, 4-pyrrolino Pyridine, 2-methyl-4-dimethylaminopyridine and the like. Among them, 4-dimethylaminopyridine,
4-Pyrrolidinopyridine is particularly preferred.

According to the present invention, the heat melting reaction is carried out in the presence of the catalyst represented by the above formula (III),
A method for producing an aromatic polyester having an excellent color tone and a small amount of sublimate generated during the reaction is provided.

In this reaction, first, a diaryl carbonate mainly reacts with a dicarboxylic acid component and a diol component to produce phenols. Generally, aromatic dicarboxylic acids have low solubility, so that high temperatures are required to initiate the initial reaction and long times are required to complete the initial reaction. However, when the compound represented by the above formula (III) is used, the initial generation of phenols is started at a very low temperature and in a short time. for that reason,
It is assumed that the time required for the reaction is shortened and the hue of the obtained polymer is significantly improved. Such a compound (II
The use amount of I) is not particularly limited, but is preferably 0.01 mol% to 1 mol% with respect to the component (a). If the amount is less than 0.01 mol%, the effect of the compound as a catalyst becomes insufficient. On the other hand, if it is more than 1 mol%, the physical properties of the obtained polymer may be undesirably reduced. More preferably, it is 0.05 mol% to 0.8 mol%. Further, such a compound (III) may be used in the form of an organic acid salt or an inorganic acid salt.

Further, conventionally known transesterification catalysts other than the above compound (III) may be used in combination. Examples of these transesterification catalysts include simple substances such as tin, strontium, zinc, cobalt, nickel, titanium, germanium, alkali metals, alkaline earth metals, oxides, hydroxides, halides, inorganic and organic acid salts, Complex salts and the like.

The polymerization temperature during the heat polycondensation is from 280 to 4
It is necessary to be 00 ° C. Here, the polymerization temperature means a temperature at the end of the polymerization or at the end thereof. If the polymerization temperature is lower than 280 ° C., the melt viscosity of the polymer becomes high, so that a polymer having a high degree of polymerization cannot be obtained.

In the production method of the present invention, it is preferable that the initial temperature of the polymerization reaction is relatively low, and that the temperature is gradually raised to finally reach the above-mentioned polymerization temperature. The reaction temperature of the initial polymerization reaction at this time is preferably 180 to 320 ° C. This polymerization reaction is carried out under normal pressure or under reduced pressure. At the time of normal pressure, it is preferable to be in an atmosphere of an inert gas such as nitrogen or argon. The polycondensation reaction time is not particularly limited, but is generally about 1 to 10 hours.

The aromatic polyester of the present invention obtained by the above-mentioned production method is mixed with a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40),
It is necessary that the intrinsic viscosity measured at 5 ° C. is 0.3 or more. If the intrinsic viscosity is lower than 0.3, the obtained polymer has insufficient heat resistance and toughness, which is not preferable. In practice, the upper limit of the viscosity is preferably about 2.

The aromatic polyester of the present invention is an amorphous polymer, and a transparent molded article can be obtained by a melt molding method such as injection molding. Further, the fact that the polymer of the present invention is amorphous can be confirmed by, for example, the fact that its melting point cannot be obtained by DSC.

In the production of the aromatic polyester or polyester carbonate of the present invention, various additives such as a stabilizer, a colorant, a pigment and a lubricant may be added as needed.

[0046]

According to the production method of the present invention, an aromatic polyester having a good color tone can be directly produced without pre-esterifying a dicarboxylic acid component or a diol component while maintaining good heat resistance and mechanical properties. It can be obtained from dicarboxylic acid and diol by an inexpensive melt polymerization process with almost no sublimation.

The aromatic polyester of the present invention has heat resistance,
It has transparency and the like and can be suitably used for molded articles such as automotive light covers and electronic members.

[0048]

The present invention will be described in detail with reference to the following Examples, in which "parts" means "parts by weight". The intrinsic viscosity was measured at a temperature of 35 ° C. in a phenol / 1,1,1,2,2-tetrachloroethane mixed solvent (weight ratio 60/40).
The thermal characteristics of the polymer were measured at a heating rate of 10 ° C./min using DSC. About color tone, Nippon Denshoku Industries Co., Ltd.
The L value (brightness) and the b value (yellowness) were measured using Z-300A manufactured by Toshiba Corporation.

Example 1 83.1 parts of terephthalic acid, 83.1 parts of isophthalic acid,
2,2-bis (4-hydroxyphenyl) propane 22
8.3 parts, 428.4 parts of diphenyl carbonate, 4-
0.244 parts of dimethylaminopyridine is placed in a reaction vessel having a vacuum distillation system equipped with a stirrer and a nitrogen inlet,
The reaction was started at 200 ° C. After 30 minutes, the temperature was raised to 220 ° C., and after 1 hour at the same temperature, distillation of phenol was confirmed, and then the pressure in the system was gradually reduced. Four hours after the start of the reaction, it was confirmed that the raw materials were uniformly dissolved. Thereafter, the temperature was further increased and the pressure was reduced.
0 ° C. and about 0.5 mmHg. Polymerization was performed for 1 hour under the same conditions to obtain a polymer. At this time, almost no sublimate was generated. The obtained polymer was pale yellow and transparent. The intrinsic viscosity was 0.32 and the glass transition temperature was 149 ° C.

Using an injection molding machine (M-50B manufactured by Meiki Seisakusho Co., Ltd.), the obtained polymer was polymerized at a polymer temperature of 30.
Injection molding is performed at 0 ° C and mold temperature 100 ° C, and the thickness is 2
mm was obtained. The L value was 93 and the b value was 7.1.

Example 2 The procedure of Example 1 was repeated, except that 0.296 parts of 4-pyrrolidinopyridine was used instead of 4-dimethylaminopyridine. Four hours after the start of the reaction, it was confirmed that the raw materials were uniformly dissolved. The obtained polymer was pale yellow and transparent. Intrinsic viscosity 0.36, glass transition temperature 17
6 ° C. At this time, almost no sublimate was generated. The L value was 92 and the b value was 7.2.

Example 4 In the same manner as in Example 1 except that 268.4 parts of 1,1-bis (4-hydroxyphenyl) cyclohexane was used instead of 2,2-bis (4-hydroxyphenyl) propane. went. Two hours after the start of the reaction, the inside of the system is
At the point of g, it was confirmed that the raw materials were uniformly dissolved. Thereafter, the temperature was further increased and the pressure was reduced.
0.5 mmHg was set. Polymerization was carried out under the same conditions for 60 minutes to obtain a polymer. At this time, almost no sublimate was generated. The obtained polymer was pale yellow and transparent. The intrinsic viscosity was 0.55 and the glass transition temperature was 182 ° C.

Comparative Example 1 83.1 parts of terephthalic acid, 83.1 parts of isophthalic acid,
2,2-bis (4-hydroxyphenyl) propane 22
8.3 parts, 428.4 parts of diphenyl carbonate, 2-
0.244 parts of dimethylaminopyridine is placed in a reaction vessel having a vacuum distillation system equipped with a stirrer and a nitrogen inlet,
The reaction was started at 200 ° C. After 30 minutes, the temperature was raised to 220 ° C. The mixture was kept at the same temperature for 2 hours, but no phenol was distilled off. Thereafter, the temperature was raised to 260 ° C. and maintained at the same temperature for 1 hour, so that phenol distillation started. Thereafter, the pressure was gradually reduced, but the raw materials did not dissolve uniformly even after 6 hours from the start of the reaction.

Comparative Example 2 83.1 parts of terephthalic acid, 83.1 parts of isophthalic acid,
2,2-bis (4-hydroxyphenyl) propane 22
8.3 parts, 428.4 parts of diphenyl carbonate, 4-
0.190 parts of hydroxypyridine was placed in a reaction vessel having a vacuum distillation system equipped with a stirrer and a nitrogen inlet, and 20
The reaction was started at 0 ° C. After 30 minutes, the temperature was raised to 220 ° C. The mixture was kept at the same temperature for 1 hour, but no phenol was distilled off. Thereafter, the temperature was raised to 240 ° C. and maintained at the same temperature for 1 hour, so that phenol distillation started. Thereafter, the pressure was gradually reduced, but the raw materials did not dissolve uniformly even after 6 hours from the start of the reaction.

Comparative Example 3 83.1 parts of terephthalic acid, 83.1 parts of isophthalic acid,
2,2-bis (4-hydroxyphenyl) propane 22
8.3 parts, diphenyl carbonate 428.4 parts, di-
0.105 parts of n-butyltin-diacetate was placed in a reaction vessel having a vacuum distillation system equipped with a stirrer and a nitrogen inlet, and the reaction was started at 200 ° C. After 30 minutes, the temperature was raised to 260 ° C. When kept at the same temperature for 1 hour, distillation of phenol started. Thereafter, the pressure was gradually reduced and the temperature was raised. Five hours after the start of the reaction, the mixture was uniformly dissolved at 320 ° C. and 50 mmHg. After further reducing the pressure to about 0.5 mmHg,
Polymerization was carried out for an hour to obtain a polymer. At this time,
7.3 parts were produced. The obtained polymer was brown and transparent. Intrinsic viscosity is 0.48, glass transition temperature is 176 ℃
Met. The L value was 73 and the b value was 46.1.

Continuation of front page (56) References JP-A-3-68626 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 63/00-63/91 CA (STN) REGISTRY ( STN)

Claims (2)

(57) [Claims] 1. A formula (I) ## STR1 ## ^{HOOC-A 1 -COOH ... (I} ) (A 1 of the formula (I) may be substituted is an aromatic group.) Represented by Dicarboxylic acid component (a) and the following formula (II): HO—A ² —X—A ³ —OH (II) (A ² and A ^{3 in} formula (II) may be substituted respectively. X is a phenylene group. Represents R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 or 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, It is selected from aralkyl groups having 6 to 12 carbon atoms. q shows the integer of 4-10. The diol component (b) represented by the following formula (III) is reacted with the diol component (b) in the presence of diaryl carbonate (c) to produce an aromatic polyester. (R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 6 to 12 carbon atoms. selected from. also, R ⁵ and may be a bond between R ⁶ .R ⁷ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 or 6 carbon atoms An aryl group having 6 to 12 carbon atoms and 6 to 12 carbon atoms
Selected from 12 aralkyl groups. n shows the integer of 1-4. ), But in the absence of an antimony compound, the following formulas (2), (3) and (4): 0.8 ≦ (A + B) /C≦1.2 (2) 0.95 ≦ A / B ≦ 1.05 (3) 1.8 ≦ C / A ≦ 2.2 (4) (where A is a dicarboxylic acid component (a), and B is a diol) Wherein the components (b) and C are the moles of the diaryl carbonate (c) in a molar ratio that simultaneously satisfies the reaction. , 1,2,2-tetrachloroethane mixed solvent ( measured at 35 ° C. in a weight ratio of 60/40). 2. A compound represented by the formula (III):
The method for producing an aromatic polyester according to claim 1, wherein the amount of the aromatic polyester is 0.05 to 0.8 mol% based on the component (a).