JP2698667B2 - Manufacturing method of aromatic polyester - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an aromatic polyester by adding 4-dimethylaminolysine as a polymerization catalyst.

The aromatic polyester of the present invention is obtained by melt-polymerizing a mixture of a derivative of an aromatic dicarboxylic acid and a diol compound in the presence of a specific electron-donating amine catalyst.

BACKGROUND OF THE INVENTION Such aromatic polyesters are well known as materials suitable for molding, extrusion, casting and film forming applications.

When such an aromatic polyester is produced, preferred catalysts include alkali metals such as basic catalysts such as lithium, sodium, potassium, rubidium, cesium and francium as described in JP-B-62-218417. Carbonate, hydroxide, hydride and the like.

Such aromatic polyesters have good tensile properties,
It is known to have a variety of useful properties such as impact and bending strength, high thermal deformation and decomposition temperatures, resistance to ultraviolet radiation and good electrical properties.

(Problems to be Solved by the Invention) The above-mentioned aromatic polyesters generally show excellent physical and chemical properties, but as an unavoidable problem, the basic metal catalyst to be used is contained in the polyester produced even after polymerization. Because of the residual, the quality of the product may be deteriorated.

(Means for Solving the Problems) The present inventors have found that the above problems can be solved by producing an aromatic polyester using 4-dimethylaminopyridine (DMAP) as a catalyst. According to the present invention, in the presence of 4-dimethylaminopyridine, by melt-polymerizing a mixture of a derivative of an aromatic dicarboxylic acid and a diol compound, a high-molecular-weight polymer having a low coloration and good physical properties is provided. An aromatic polyester resin is obtained. 4-Dimethylaminopyridine is easily distilled off under a high vacuum in the final stage of polymerization, does not remain as a heterogeneous residue unlike conventionally used metal catalysts, and does not lower the quality of the polymer.

BEST MODE FOR CARRYING OUT THE INVENTION Bisphenol compounds, aliphatic diols and alicyclic diols that can be used for producing the polyester of the present invention are well-known compounds.

The production of a preferred bisphenol compound and its functional derivative is represented by the following general formula (I).

(Wherein X is -O -, - S -, - SO 2 -, - SO -, - CO
—, Selected from the group consisting of alkylene groups having 1 to 4 carbon atoms and alkylidene groups having 1 to 4 carbon atoms, wherein R ₁ , R ₂ , R ₃ , R ₄ ,
R ₁ ′, R ₂ ′, R ₃ ′ and R ₄ ′ may be the same or different and each represents an atom or a group selected from the group consisting of a hydrogen atom, a halogen atom and an alkyl group having 1 to 4 carbon atoms. I do. Examples of suitable bisphenol compounds represented by the above general formula (I) include 4,4'-dihydroxy-diphenyl ether, bis (4-hydroxy-2-methylphenyl) ether, and bis (4-hydroxy-3-chlorophenyl) Ether, bis (4-hydroxyphenyl) sulfide,
Bis (4-hydroxyphenyl) sulfone, bis (4-
(Hydroxyphenyl) ketone, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) methane, bis (4-hydroxy-3,5-dichlorophenyl) methane, bis (4-hydroxy-3,5) -Dibromophenyl) methane, 1,1-bis (4'-hydroxyphenyl) ethane, 2,2-bis (4'-hydroxy-
3'-methylphenyl) propane, 2,2-bis (4'-
(Hydroxy-3'-chlorophenyl) propane, 2,2-
Bis (4'-hydroxy-3 ', 5'-dichlorophenyl) propane; 2,2-bis (4'-hydroxy-3',
5'-dibromophenyl) propane, and 1,1-bis (4'-hydroxyphenyl) -n-butane. 2,
2-Bis (4'-hydroxyphenyl) propane (common name: bisphenol A) is the most common and readily available compound and is therefore the most commonly used.

Examples of preferred aromatic diols include hydroquinone,
Resorcinol is mentioned.

Examples of preferred aliphatic diols include ethylene glycol, propylene glycol, 1,4-butanediol,
Examples include diethylene glycol and polytetramethylene glycol.

Examples of preferred alicyclic diols include cyclohexanediol and cyclohexanedimethanol.

Suitable dicarboxylic acids include aromatic dicarboxylic acids such as isophthalic acid and terephthalic acid.

When the dicarboxylic acid used in the preparation of the polyester of the present invention is a mixture of isophthalic acid and terephthalic acid according to a particularly preferred embodiment of the present invention, the weight ratio of isophthalic acid residues to terephthalic acid residues in the polyester is about 90%. : 1
Particularly good results are obtained if it is in the range from 0 to 10:90, preferably from about 75:25 to 90:10.

When the polyester of the present invention is produced using the above-described melt transesterification polymerization method of the present invention, the dicarboxylic acid reaction component is generally a diaryl ester of dicarboxylic acid.

The diaryl ester of dicarboxylic acid used as a reaction component in the melt transesterification polymerization method of the present invention,
It is a diester of dicarboxylic acid with benzene having 6 to 20 carbon atoms or a naphthalene series monohydroxy aromatic compound. Examples of such monohydroxyaromatic compounds are phenol, o-, m- or p-cresol,
Halophenols such as xylenol, p-chlorophenol, 3,5-dibromophenol, nitrophenols such as om- or p-nitrophenol,
1-naphthol, 2-naphthol, 1-hydroxy-4
-Methylnaphthalene, thiophenols and the like. Preferably, the ester reactant is an ester derived from a monohydroxy aromatic hydrocarbon, more preferably a monohydroxy aromatic hydrocarbon of the benzene series, especially phenol itself. Dicarboxylic acid ester reaction component 2
The ester groups can be derived from different monohydroxyaromatic compounds, but preferably both ester groups of the dicarboxylic acid ester reaction component are derived from the same monohydroxyaromatic compound.

In the production of the polyester of the present invention, the proportion of each of the dicarboxylic acid and bisphenol reactive components used is such that at least a part of the polyester product is a carboxylate group terminal (that is, the dicarboxylic acid reactive component is added to the terminal group of the produced polyester). (The proportion that forms a polyester containing monomer residues). As we all know,
In the linear aromatic polyester composed of bisphenol and dicarboxylic acid monomer residues, the terminal portion of the carboxylate group is determined based on the ratio of the dicarboxylic acid reactive component to the stoichiometric excess relative to the molar amount of the bisphenol compound. By using the dicarboxylic acid reactants in molar proportions up to a stoichiometrically somewhat deficient proportion (corresponding to a proportion in which the molar quantity of the bisphenol compound is about 5 mol% in stoichiometric excess). can get. Preferably, the polyester of the present invention is produced using the dicarboxylic acid reaction component in a molar amount that is substantially stoichiometrically equivalent to the molar amount of the bisphenol compound.

The use ratio of the above reaction components can be applied to the case of an aromatic diol other than the bisphenol compound.

When a polyester is produced using an aliphatic diol and an alicyclic diol, polymerization is carried out using about 2 equivalents of a diol component with respect to a dicarboxylic acid reaction component.
More preferably, the polymerization is carried out using 2.0 to 2.2 equivalents of the diol component.

Dimethylaminopyridine (DMAP) used as a catalyst in the present invention can be used in a catalytically effective amount, for example, from about 0.005 to 2 mol% or more, preferably about 0.02 mol% of the bisphenol compound according to known polyester production methods.
1 to 1 mol% of catalyst are used.

The method of the present invention can be carried out by employing reaction conditions generally used in a melt polymerization method.

The production of conventional linear aromatic polyesters comprising a residue of a bisphenol compound and a dicarboxylic acid by transesterification polymerization involves preparing a mixture of a bisphenol compound and a diaryl dicarboxylate, preferably in a substantially anhydrous, unpleasant atmosphere (eg, In a dry nitrogen atmosphere), the reaction components are liquefied. That is, it is performed by heating to a high temperature (generally about 100 ° C. or higher) sufficient to form a molten reaction system. Optionally, a polymerization reaction at a temperature lower than the melting points of the reaction components and products, i.e., a solid state polymerization reaction,
Further, a transesterification polymerization reaction can be performed.

According to conventional methods, the solid reactant is heated above about 100 ° C., preferably above about 160 ° C., to melt the reactant. The onset of the reaction in the presence of the catalyst is generally about 10
The reaction takes place at a temperature of from 0 to 275 ° C., for example at temperatures above about 160 ° C. in the case of the reaction of bisphenol A, diphenyl terephthalate and diphenyl isophthalate. The reaction temperature used is generally about 100-400 ° C or higher, preferably about 175-350 ° C, more preferably about 175-330 ° C,
The reaction temperature is gradually increased during the polymerization.

In the polymerization reaction, the aryl group of terephthalic acid and / or isophthalic acid diaryl ester is substituted and liberated as a relatively volatile corresponding monohydroxy aromatic compound (eg, phenol), which is removed from the reaction mixture during the polymerization. Prepare to remove (eg, evaporate). The reaction pressure is generally during the reaction, e.g., about 0.5, to facilitate the above-described removal of the monohydroxyaromatic compound.
Reduce to 1 Torr or less.

The following examples are provided to further illustrate various aspects of the present invention and are not intended to limit the present invention. Various modifications can be employed within the scope of the present invention.

Example 1 Example 1 of diphenyl isophthalate / diphenyl terephthalate
31.8 g (0.100 mol) of a 50 mol% / 50 mol% mixture, 22.8 g (0.100 mol) of bisphenol A and 244 mg (2.00 × 10 ⁻³ mol) of 4-dimethylaminopyridine (DMAP) were dried in a vacuum dryer, respectively. Next, a stirrer, a gas introduction pipe,
The reaction flask was charged with a phenol receiver and an oil jacket. The system was flushed with dry nitrogen and the oil temperature was raised to 200 ° C. While the system was in a molten and homogeneous state, the system was evacuated with continued stirring to gradually increase the degree of vacuum to remove phenol. At the end of this heating cycle
1.5 hours was at about 280 ° C. and 0.5 Torr. After completion of the heating cycle, the pressure was released with dry nitrogen, and the polymer was taken out. The obtained polymer was very pale yellow, and the viscosity average molecular weight of this polymer was calculated by the following relational expression. That is, 25% of a wholly aromatic polyester obtained from a bisphenol compound and terephthalic acid or isophthalic acid.
The intrinsic viscosity [η] was measured using a tetrahydrofuran (THF) solution at ° C. and the molecular weight v was obtained as a relational expression.

[Η] THF (25 ° C.) = 6.17 × 10 ⁻⁴ v ^0.625 (II) U polymer (manufactured by Unitika) calculated from intrinsic viscosity using (M.E. Karahora, Polymer Engineering Science, vol. 24, page 608, 1984) It is a converted molecular weight.

The viscosity average molecular weight of the polymer obtained from the above relational expression is
32,500. When the glass transition point (Tg) was measured, the polymer was found to have a Tg of 190 ° C.

Example 2 This example is the same as Example 1 except that bisphenol A was replaced by 25.6 g (0.100 mol) of 2,2-bis (4-hydroxy-3-methylphenyl) propane (bisphenol C). It is. The resulting polymer was simple yellow, transparent and tough. The viscosity average molecular weight of this polymer was 29,800 (the molecular weight in terms of U polymer calculated from the formula (II)). Tg was 150 ° C.

Example 3 In this example, bisphenol A was replaced with bisphenol A (11.4 g, 5.00 × 10 ^-2 mol) and bisphenol C, 12.8 g.
(5.00 × 10 ⁻² mol), except that a mixture was used. The obtained polymer was transparent, tough and pale yellow. The viscosity average molecular weight of this polymer is 3
It was 1,800 (the molecular weight in terms of U polymer calculated from the formula (II)).

Example 4 of diphenyl isophthalate / diphenyl terephthalate
31.8 g (0.100 mol) of a 50 mol% / 50 mol% mixture 19.8 g (0.220 mol) of 1,4-butanediol and 244 mg of DMAP (2.00 mol
× 10 ^-3 mol) was dried, and then a reaction flask equipped with a stirrer, a gas inlet tube, a phenol receiver, and an oil jacket was charged. The subsequent reaction operation is the same as in Example 1. The resulting polymer was pale yellow, transparent and tough. The viscosity average molecular weight of this polymer was calculated by the following relational expression. That is, using a solution of a wholly aromatic polyester obtained from 1,4-butanediol and isophthalic acid or terephthalic acid at 25 ° C. in an o-chlorophenol solution, the intrinsic viscosity [η] and the molecular weight v can be obtained as a relational expression. [Η] _{O-chlorophenol (25 ° C.)} = 6.31 × 10 ⁻⁴ v
It is the viscosity average molecular weight calculated from the intrinsic viscosity using ^0.72 (II).
The viscosity average molecular weight of the obtained polymer was 28,000.
The melting point (Tm) was 222 to 223 ° C.

Comparative Example 1 When the same reaction as in Example 1 was performed using triethylamine as a catalyst, only a polymer having a molecular weight of about 3,000 was obtained.

(Effect of the Invention) Since 4-dimethylaminepyridine is used as a catalyst, the reaction can be performed in a homogeneous system unlike the case where a metal catalyst is used, and a transparent and tough high molecular weight polyester with little coloring can be obtained. Further, the obtained polymer does not remain as a heterogeneous residue as in the case of a metal catalyst or the like, and does not lower the quality.

Claims (1)

(57) [Claims] 1. A process for producing an aromatic polyester, comprising melt-polymerizing a mixture of a derivative of an aromatic dicarboxylic acid and a diol compound in the presence of 4-dimethylaminopyridine.