JPH0242097B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing an aromatic polyester composition. More specifically, a specific low molecular weight compound with a molecular weight of 1000 or less that is substantially non-reactive with the polyester raw material, the aromatic polyester raw material to be produced, and the aromatic polyester to be produced, and which is difficult to distill off under polycondensation reaction conditions. In the presence of
The present invention relates to a method for producing an aromatic polyester composition with excellent moldability and a high degree of polymerization by adding 90 to 200 equivalent % of diaryl carbonate and performing a melt polycondensation reaction. (Prior art) Aromatic polyesters derived from aromatic dicarboxylic acids and bisphenols, so-called polyarylates, have been known as polymers with excellent heat resistance and mechanical properties. Various uses are being considered. As a preferred method for producing polyarylates, a method has been known in which a diaryl ester of an aromatic dicarboxylic acid and a bisphenol are polymerized by transesterification. However, polyarylates are generally polymers with high melt viscosity, and when produced by melt polymerization, it is necessary to polymerize at extremely high temperatures, and there are also problems such as coloring and a decrease in the degree of polymerization due to thermal decomposition. .
As a method to improve these problems, a method using solid phase polymerization in combination has been proposed, but this method requires a long reaction time and has the problem of low productivity. (Problems to be Solved by the Invention) The present invention aims to eliminate the above-mentioned drawbacks and provide a method for producing polyarylate with a high degree of polymerization by melt polymerization at a relatively low temperature that can suppress thermal decomposition. It is. (Means for Solving the Problem) As a result of intensive research, the present inventors have discovered that the above object can be achieved by performing melt polymerization by adding a specific proportion of diaryl carbonate in the presence of a specific low molecular weight compound. This is what led to the discovery of the present invention. That is, the present invention provides a polyester raw material comprising (A) an aromatic dicarboxylic acid and/or an ester-forming derivative thereof and (B) an aromatic dihydroxy compound, or a polyester raw material comprising (A) and (B) above.
(C) A polyester raw material consisting of an aromatic monooxymonocarboxylic acid and/or an ester-forming derivative of its carboxyl group, in which at least a portion of the above (A) and/or the above (C) is a free carboxyl group. contains a carboxyl group and/or
Or, the polyester raw material consisting of the ester-forming derivative group and the hydroxyl group in substantially equal amounts, (D) the following formula (1) [Here, A ¹ is a divalent aromatic hydrocarbon residue; R ¹ is an n-valent aromatic hydrocarbon residue or a chain or cyclic aliphatic residue, and n is 1 or 2; be. However, the imide ring in the above formula is 5 or 6 members. ] In the presence of an imide compound with a molecular weight of 1000 or less that is substantially non-reactive with the above raw materials and the produced polymer, (E) 90-90 to the free carboxyl group is
By adding 200 equivalent% diaryl carbonate,
This is a method for producing an aromatic polyester composition characterized by carrying out polycondensation in a molten state. Examples of aromatic dicarboxylic acids used as component (A) in the present invention include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid,
Examples include diphenoxyethane dicarboxylic acid, diphenyl ether dicarboxylic acid, methyl terephthalic acid, and methyl isophthalic acid, with terephthalic acid and isophthalic acid being particularly preferred. Further, examples of the aromatic dihydroxy compound used as component (B) include hydroquinone, resorcinol, chlorohydroquinone, bromohydroquinone, methylhydroquinone, ethylhydroquinone, t-butylhydroquinone, t-amylhydroquinone, (α-phenylethyl)hydroquinone, ( 2-phenylprop-2-yl)hydroquinone, phenylhydroquinone, benzylhydroquinone, methoxyhydroquinone, 4,
4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, bis(4-hydroxyphenoxy)ethane, 2,2'-dimethyl-4,
4'-dihydroxydiphenyl, 3,3'-dimethoxy-4,4'-dihydroxydiphenyl ether,
Bis(2-chloro-4-hydroxyphenoxy)
Examples include ethane, 2,2-bis(4'-hydroxyphenyl)propane, and 1,1-bis(4'-hydroxyphenyl)cyclohexane. Among these, the above-mentioned substituted hydroquinones such as 2,2-bis(4'-hydroxyphenyl)propane, hydroquinone and methylhydroquinone are particularly preferred. In addition, examples of the aromatic monooxymonocarboxylic acid used as component (C) include p-oxybenzoic acid, 4-oxydiphenyl-4'-carboxylic acid,
-chloro-4-oxybenzoic acid, 3-methoxy-4-oxybenzoic acid, 3-ethoxy-4-oxybenzoic acid, 2-methyl-4-oxybenzoic acid,
3-Methyl-4-oxybenzoic acid, 2-phenyl-4-oxybenzoic acid, 3-phenyl-4-oxybenzoic acid, 2-chloro-4-oxydiphenyl-4'-carboxylic acid, 2-hydroxynaphthalene-
Examples include 6-carboxylic acid. Among these, p-oxybenzoic acid is preferred. The ester-forming derivatives of the aromatic dicarboxylic acids and aromatic oxycarboxylic acids include those obtained by converting the carboxylate groups of the aromatic dicarboxylic acids and aromatic oxycarboxylic acids into lower alkyl esters or aryl esters, such as dimethyl esters, Examples include diethyl ester, diphenyl ester, ditolyl ester, and dinaphthyl ester. Of these,
Among the aryl esters, diphenyl esters are particularly preferred. Examples include diphenyl terephthalate, diphenyl isophthalate, and phenyl p-oxybenzoate. In the present invention, at least a portion of the component (A) and/or the component (C) must contain a free carboxyl group. Furthermore, in the present invention, it consists of component (A) and component (B), or component (A),
The polyester raw material consisting of component (B) and component (C) is
As is well known in the art, the amount used is such that the total amount of carboxyl groups and/or their ester-forming derivative groups and the total amount of hydroxyl groups in all raw materials are substantially equivalent. The polyester raw material used in the present invention is a combination of the above (A) component and (B) component or each of the above (A), (B), and (C) components, but in some cases, the above (A),
Ester-forming compounds other than the components (B) and (C) may be used together in a proportion of 30 mol% or less. Examples of such other compounds include aliphatic or alicyclic dicarboxylic acids such as adipic acid, sebacic acid, and cyclohexanedicarboxylic acid, which can be used to partially replace the aromatic dicarboxylic acid (A); Examples include ester-forming derivatives of. Further, examples of aromatic dihydroxy compounds other than (B) that can be used by partially substituting the aromatic hydroxy compound (B) include ethylene glycol, neopendylene glycol, hexamethylene glycol, tetramethylene glycol, and cyclohexane dimethylol. Mention may be made of aliphatic or alicyclic diols such as. In addition, some aromatic oxycarboxylic acids (C) (up to
Examples of other oxycarboxylic acids that can be used as substitutes (up to 30 mol%) include oxycarboxylic acids having aliphatic hydroxyl groups such as p-hydroxyethoxybenzoic acid and oxycaproic acid, or ester-forming derivatives thereof, such as allyl. Examples include esters, alkyl esters, and lower fatty acid esters. Ester-forming compounds other than the above-mentioned components (A), (B), and (C) can be used alone or in combination, but when used together, the total amount is the main component. A whole aromatic compound (i.e. (A),
(B), (C) total components) preferably does not exceed 30 mol%, more preferably does not exceed 20 mol%. On the other hand, the low molecular weight compound used as component (D) in the method of the present invention is substantially non-reactive with the polyester raw material and the wholly aromatic polyester produced, and is at least difficult to distill off under the polycondensation reaction conditions. , is an imide compound represented by the following formula (1) and having a molecular weight of 1000 or less. [Here, A ¹ is a divalent aromatic hydrocarbon residue; R ¹ is an n-valent aromatic hydrocarbon residue or a chain or cyclic aliphatic residue, and n is 1 or 2; be. However, the imide ring in the above formula is 5 or 6 members. ] In the above formula (1), the divalent aromatic residue representing A ¹ is, for example, a 1,2-phenylene group,
Examples include 1,2-, 2,3- or 1,8-naphthylene groups. The n-valent aromatic hydrocarbon residue (n=1 or 2) representing R ¹ is, for example, a monovalent aromatic hydrocarbon residue such as a phenyl group or a naphthyl group (n=1
), or 1,2-phenylene group, 1,2-,
2, such as a 2,3- or 1,8-naphthylene group;
Examples of n-valent (n=1 or 2) aliphatic residues include methyl, ethyl, butyl, hexyl, heptyl, octyl. , nonyl, decyl,
A chain alkyl group having 1 to 18 carbon atoms such as dodecyl, myricityl, and stearyl, or a 5- or 6-membered cyclic alkyl group such as cyclohexyl or cyclopentyl (where n=1), or ethylene,
A chain alkylene group having 2 to 12 carbon atoms such as trimethylene, tetramethylene, hexamethylene, octamethylene, decamethylene, dodecamethylene,
Examples include cyclic alkylene groups such as 1,3- or 1,4-cyclohexylene groups. The low molecular weight imide compound represented by the above formula (1) with a molecular weight of 1000 or less can be produced from a corresponding acid anhydride and an organic amine by a method known per se. Among the imide compounds represented by the above formula (1), they are used as a dyeability improving agent for modified polyester (see Japanese Patent Publication No. 44-9677) or as a crystallization accelerator for polyethylene terephthalate injection molding materials (Japanese Patent Publication No. 56/1989). (Refer to Publication No. 84747) Some are known. On the other hand, examples of the diaryl carbonate used as component (E) in the present invention include diphenyl carbonate, ditolyl carbonate, and dibutyl carbonate, with diphenyl carbonate being the most preferred. Such diaryl carbonate is a polyester raw material with respect to the free carboxyl group of the carboxylic acid component used as part or all of the above component (A) and/or component (C).
It is used in an amount of 90 to 200 equivalent %. Preferably 95-150
Equivalent %, more preferably 100 to 120 equivalent %. The method of the present invention can be carried out by polycondensing the polyester raw material as described above in the molten state by adding a predetermined amount of diaryl carbonate in the presence of the specific low molecular weight compound as described above. , a composition containing the desired highly polymerized aromatic polyester and a low molecular weight compound (D) is obtained. (Effects of the Invention) According to the method of the present invention, by carrying out the polycondensation reaction in the presence of a specific low molecular weight compound (D), the degree of polymerization is the same as that in the case where only the raw materials for polyester are polycondensed. When compared with the case of producing a wholly aromatic polyester, it becomes possible to carry out the polycondensation at a significantly lower polycondensation temperature. Furthermore, the resulting polyester composition can be molded into fibers, films, resins, etc. at relatively low temperatures;
In particular, when the molded product is a fiber or film-like product, the low molecular weight compound (D) is an organic solvent that does not react with the polyester, such as toluene, xylene, chlorobenzene, acetone, ethyl acetate, dioxane,
Since it is soluble in ethanol, chloroform, methylene chloride, etc., it can be easily extracted and removed from the molded product after molding, and it is also possible to express the performance of the aromatic polyester alone. Therefore, according to the method of the present invention, aromatic polyester (arylate), which is normally difficult to melt polymerize due to its high melting point and high viscosity, can be efficiently produced by melt polymerization. In particular, it is industrially advantageous because the reaction can be carried out at a relatively low temperature or with a small load compared to conventional methods. Furthermore, the produced aromatic polyester has the advantage of improved color tone and excellent moldability. (Example) Hereinafter, the present invention will be explained in detail by giving examples. In addition, "parts" in all examples mean "parts by weight." Examples 1 to 3 and Comparative Example 1 166 parts of isophthalic acid, 92.4 parts of hydroquinone,
47.9 parts of bisphenol A, 224.7 parts of diphenyl carbonate, 0.15 parts of antimony trioxide, and predetermined amounts of the low molecular weight compounds shown in Table 1 were charged into a reactor equipped with a stirrer, and the phenol produced by the reaction in a nitrogen gas stream was charged. While distilling out of the system, at 280℃ for 60 minutes,
Next, the temperature was raised to 300°C for 30 minutes, then further raised to 330°C, and the pressure inside the reaction system was gradually reduced until the absolute pressure reached approximately 30 minutes later.
The reaction temperature was kept at 0.5 mmHg or less, and the reaction was continued for an additional 60 minutes. Table 1 shows the melt viscosity of the polymer determined from the torque during stirring and the obtained polymer into chips.
The intrinsic viscosity of the polymer after the chip was immersed in refluxing xylene for 1 hour to extract the contained imide compound, and the melting point of the polymer before and after extraction are shown. For comparison, when polymerization was carried out under the same conditions as above without using any aromatic imide compound, the reactant solidified during the reduced pressure reaction. When the solidified reaction product was pulverized into 10 to 20 meshes and reacted at 270° C. under a reduced pressure of about 0.5 mmHg, it took 24 hours for the reduced specific viscosity of the polymer to reach 1.01. Table 1 also shows the properties of the polymer that was finally obtained after a long period of time.

[Table] Examples 4 to 7 and Comparative Example 2 p-oxybenzoic acid in a three-neck reactor equipped with a stirrer
82.8 parts, diphenyl isophthalate 127.2 parts, hydroquinone 46.2 parts, diphenyl carbonate
134.8 parts of stannous acetate, 0.10 parts of stannous acetate, and the specified amount of the low molecular weight compound shown in Table 2 were added, and the mixture was heated at 250 to 330 ml under normal pressure.
℃ for 90 minutes, then the pressure inside the system was gradually reduced to about 0.1 mmHg absolute pressure after 30 minutes, and the reaction was carried out for the time shown in Table 2. Table 2 shows the melt viscosity (380° C. shear rate 100 sec ⁻¹ ) and softening temperature of the obtained polymer composition and the polymer obtained by extracting the composition with refluxing dioxane. For comparison, a polycondensation reaction was carried out under the same conditions as above without adding any low molecular weight compound, but the reaction product solidified during the reduced pressure reaction.

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Claims (1)

[Scope of Claims] 1. A polyester raw material comprising (A) an aromatic dicarboxylic acid and/or its ester-forming derivative and (B) an aromatic dihydroxy compound, or (A) and (B) above.
and (C) an aromatic monooxymonocarboxylic acid and/or an ester-forming derivative of its carboxyl group, which comprises (A) and/or an ester-forming derivative thereof.
Or, at least a part of the above (C) contains a free carboxyl group, and a polyester raw material in which the carboxyl group and/or its ester-forming derivative group and the hydroxyl group are substantially equivalent, ( D) The following formula (1) [Here, A ¹ is a divalent aromatic hydrocarbon residue; R ¹ is an n-valent aromatic hydrocarbon residue or a chain or cyclic aliphatic residue, and n is 1 or 2; be. However, the imide ring in the above formula is 5 or 6 members. ] In the presence of an imide compound with a molecular weight of 1000 or less that is substantially non-reactive with the polyester raw material represented by and the produced polyester and is difficult to distill off under polycondensation conditions, (E) 90 to 200 1. A method for producing an aromatic polyester composition, which comprises adding an equivalent amount of diaryl carbonate and polycondensing it in a molten state.