JPH01188522A - Production of polyester - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent heat-resistance, etc., and useful as a film, fiber, etc., in high efficiency, by acyliating an aromatic diol and polycondensing the obtained diacylated compound with a dicarboxylic acid under reduced pressure without separating or purifying the diacylated compound. CONSTITUTION:(A) An aromatic diol of formula HO-R<4>-OH [R<4> is group of formula I (Y<5>-Y<8> are H, halogen, etc.) or formula II (Y<9>-Y<12> are H, alkyl, etc.), etc.] is acylated with (B) an acylation agent (preferably acetic anhydride) preferably at 80-200 deg.C to obtain a diacylated compound. The objective composition is produced by polycondensing the diacylated compound with (C) a dicarboxylic acid of formula HOOC-R<1>-COOH (R<1> is group of formula I, a bivalent aliphatic residue, etc.) (preferably terephthalic acid, etc.) under reduced pressure (preferably reducing the pressure at 220-330 deg.C spending 40min), without separating and purifying the diacylated compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in a method for producing polyester. More specifically, the present invention provides a simple method for producing aromatic polyesters with excellent mechanical properties, heat resistance, moldability, etc., which are suitable for use in various molded products, films, fibers, etc., from aromatic diols and dicarboxylic acids. The present invention relates to an economically advantageous and efficient manufacturing method.

[Prior Art] Aromatic polyesters have been widely used as materials for various molded products, films, fibers, etc., and as structural materials because of their excellent mechanical properties and heat resistance.

Methods for producing this aromatic polyester include, for example, interfacial polycondensation or solution polycondensation between an aromatic diol and dicarboxylic acid cybaride, melt polycondensation between an aromatic diol and dicarboxylic acid diphenyl ester, and aromatic diol diacetate-1. Methods such as melt polycondensation with dicarboxylic acids have been used. However, all of these methods have drawbacks such as requiring dicarboxylic acid civalide or diphenyl ester, which are more expensive than dicarboxylic acids, or using aromatic diol diacetates, which are more expensive than aromatic diols. However, this method cannot necessarily be said to be fully satisfactory in terms of manufacturing cost.

[Problems to be Solved by the Invention] The present invention overcomes the drawbacks of the conventional method for producing aromatic polyester, and produces a highly economically advantageous production process from aromatic diol and dicarboxylic acid using a simple process. The purpose of this study was to provide a method for efficiently producing polyester.

[Means for Solving the Problems] As a result of extensive research in order to achieve the above object, the present inventors first acylated an aromatic diol using an acylating agent, and then developed a diacylated product obtained by acylating an aromatic diol using an acylating agent. It was discovered that the object could be achieved by polycondensing it with a dicarboxylic acid under reduced pressure without isolating or purifying it, and based on this knowledge, the present invention was completed.

That is, in producing a polyester from an aromatic diol and a dicarboxylic acid, the present invention first acylates the aromatic diol using an acylating agent, and then isolates and purifies the obtained diacylated product. The present invention provides a method for producing polyester, which is characterized by polycondensation with dicarboxylic acid under reduced pressure.

The present invention will be explained in detail below.

In the method of the present invention, the dicarboxylic acid used as one of the raw materials has the following formula:
- group, ru) can be mentioned.

Examples of the divalent aromatic residue in the general formula (I) include (wherein Y5, Y6, Y7 and Y8 are each a hydrogen atom, a halogen atom, an alkoxy group or an alkyl group), and , R2 and R3 in the R2Al-R3- group are each a divalent aromatic residue, and A1 is an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, an alkylene group, an alkylidene group, or a direct bond.

and Y' are each a hydrogen atom, a halogen atom, an alkoxy group or an alkyl group.

Specific examples of such dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene 5-dicarboxylic acid, diphenyl-4,
4″-dicarboxylic acid, methyl terephthalic acid, methyl isophthalic acid, diphenyl ether-4,i′-dicarboxylic acid, diphenylthioether-4,4′-dicarboxylic acid, diphenylsulfone-1,4′-dicarboxylic acid, synenyl ketone-(, Aromatic dicarboxylic acids such as 4'-dicarboxylic acid, 2,2-diphenylpropane-4,4'-dicarboxylic acid, diphenyl-4,4''-dicarboxylic acid, 1,4-xylylene dicarboxylic acid, 1.3 - aralkylene dicarboxylic acids such as quinrylene dicarboxylic acid,
Chain aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, 1,4-cyclohexyldicarboxylic acid, 1
．． Examples include, but are not necessarily limited to, cycloaliphatic dicarboxylic acids such as 3-cyclohexyldicarboxylic acid, l,2-cyclohexyldicarboxylic acid, 1,3-cyclopentyldicarboxylic acid, and 1,2-cyclopentyldicarboxylic acid. It is not something that will be done. These dicarboxylic acids may be used alone or in combination of two or more. Moreover, among these, it is particularly preferable to use terephthalic acid and/or isophthalic acid from the viewpoint of cost.

Another raw material aromatic diol is - general formula % formula % () (in the formula, R4 is a divalent aromatic residue, R5 and R6 are each a divalent aromatic residue, A2 is oxygen Atom, sulfur atom, sulfonyl group, carbonyl group, alkylene group, alkylidene group or direct bond, Y9, y
lQ, Y'' and Y'2 are each a hydrogen atom, a halogen atom, an alkoxy group or an alkyl group.

Specific examples of such aromatic diols include hydroquinone, resorcin, noti-rehydroquinone, chlorohydroquinone, acedelhydroquinone, acetoxyhydroquinone, dil-rohydroquinone, dimethylaminohydroquinone, 1,4-dihydroquinnaphthol. naphthol, 1,6-cyhydroquine naphthol, 2,6
-dihydroquinaphthol, 2,7-cyhydroxynaphthol, 2,2-his(4-hydroxyphenyl)propane, 2,2-his(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-his (4-hydroxy-3,5-dichlorophenyl)-propane, 2,2-bis(4-hydroxy-3-methylphenyl)-propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, His( 4-hydroxyphenyl)-methane, his(4-hydroxyphenyl)-3,5-dimedylphenyl
-methane, his(4-hydroxy-3,5-dichlorophenyl)-methane, his(4-hydroxy-3,5-dibromophenyl)-methane,! , 1-His(4-hydroquinphenyl)cyclohexane, 4.1'-dihydroxydiphenyl, Bis(4-hydroxyphenyl)-ketone, His(4-hydroquine-3.5-dimethylphenyl)-ketone, Bis(4 -Hydroxy:/-3,5-dichlorophenyl)-ketone, his(4-hydroxyphenyl) sulfide, his(4-hydroquine-3-chlorophenyl) sulfide, his(4-hydroxyphenyl) sulfone, his(4-hy1 - Roquin-3,5-dichlorophenyl) ether and the like, but are not necessarily limited to these. These aromatic diols may be used alone or in combination of two or more, and among them, two or more are preferred in terms of cost.
, 2-his(4-hydroxyphenyl)propane and his(4-hydroxyphenyl)sulfone are particularly preferred.

In the method of the present invention, the aromatic diol is
Acylation is performed using a silating agent to produce a diacylated product. There are no particular limitations on the alkylating agent, and commonly used ones such as acetic anhydride, propionic anhydride, butyric anhydride, benzoic anhydride, etc. can be used.
Among these, acetic anhydride is preferred in terms of reactivity and cost.

These acylating agents are used in an amount of usually 0.5 to 2.0 times, preferably 0.7 to 1.5 times, relative to the aromatic diol, and there are no particular restrictions on the dropwise addition time. However, it is desirable that the dropwise addition takes 10 minutes or more, preferably 20 minutes or more.

This acylation reaction is carried out at a temperature of usually 50 to 350°C, preferably 80 to 200°C, more preferably 80 to 80°C.
It is carried out at a temperature in the range of 0°C. Further, there is no particular restriction on the reaction pressure, and the reaction may be carried out under normal pressure or under increased pressure. Furthermore, the acylation reaction may be carried out by lowering the temperature to below the boiling point of the acylating agent.

The reaction time depends on the type of acylating agent and the reaction temperature, and cannot be determined in general terms, but it is usually selected within 5 hours, preferably in the range of 10 minutes to 3 hours.

It is extremely rational and advantageous to carry out this acylation reaction in the presence of the dicarboxylic acid as a raw material.

In the method of the present invention, the diacylated product thus produced does not need to be isolated or purified, and is directly polycondensed with a dicarboxylic acid. This polycondensation reaction is usually 200~
It is preferable to carry out the reaction at a temperature of 350 DEG C., preferably in the range of 220 DEG to 330 DEG C., in which case the pressure is preferably gradually reduced initially. Regarding this decompression speed, 7 6
From 0 mmII9 to 1 mmHg for more than 30 minutes,
Preferably, it is desirable to reduce the pressure over a period of 40 minutes or more, and in particular, it is important to gradually reduce the pressure from 10 mmFly to 1 mmHg.

The acylation and polymerization reactions in the method of the present invention may be carried out without a catalyst or in the presence of a catalyst if necessary. When the reaction is carried out in the presence of a catalyst, an acylation catalyst is used for the acylation reaction, and a polymerization catalyst is used for the polymerization reaction, but these catalysts may be used in combination. The amount used is usually 5 to 50,000 p of each polymer.
p m, preferably selected in the range of 50 to 500 p m.

As the polymerization catalyst, zinc compounds, particularly zinc carboxylates such as zinc stearate, zinc acetate, and zinc benzoate, are preferred.In order to increase the polymerization rate, the polymerization catalyst is dissolved in a solvent and introduced into the system. It is preferable to add. Furthermore, in order to significantly increase the degree of polymerization, it is desirable to carry out solid phase polymerization under reduced pressure or in a nitrogen atmosphere.

[Effects of the Invention] According to the method of the present invention, an aromatic polyester having excellent mechanical properties, heat resistance, moldability, etc. can be efficiently produced from an aromatic diol and a dicarboxylic acid in a simple process and with extremely economic advantage. The aromatic polyester can be suitably used as a material or structural material for various molded products, films, fibers, etc. Thus, the method of the present invention can be said to be of extremely high industrial value.

[Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, the physical properties of the polymer were measured according to the following method.

(i) Poly-logarithmic viscosity [η,. ,] Polymer concentration 0.5 g/dQ in phenol/tetrachloroethane solvent (weight ratio 50150)
Measurements were made at a temperature of 30°C.

(2) Polymer glass transition temperature [Tg] Measured using a DSC9900 differential scanning calorimeter manufactured by DuPont under conditions of a temperature increase rate of 16'O/min in a nitrogen stream.

1 l- (3) Polymer melt viscosity 280°0. Measurement was performed under the conditions of 1 mm $ x 10 mm orifice.

Example 1 A glass polymerization tube equipped with a stirring blade, a nitrogen inlet, and a pressure reduction port was
Terephthalic acid 14.95g (0.09 mol), Isophthalic acid 34.899 (0.21 mol), Hisphenol A
68.489 (0.30 mol) was charged, vacuum and nitrogen substitution was repeated three times, and finally nitrogen was filled and the polymerization tube was sealed.

The polymerization tube was heated to 170'O in an electric furnace to melt the contents, and stirring was started. Next, while lowering the internal temperature to 140°C, 73.45 g (0.72 mol) of acetic anhydride was added dropwise over 30 minutes, and after the dropwise addition was completed, the mixture was maintained at 140°C for 2 hours to perform acylation. Next, after raising the internal temperature to 300 ° C, 0.0659 of zinc acetate dihydrate was dissolved in N-methyl-2-pyrrolidone and added as a 1 g solution.
Gradually reduce the pressure (finally 0.3 mmIIg)
(in a high vacuum state), polymerization was carried out for 1 hour. Thereafter, stirring was stopped, and the pressure inside the polymerization tube was restored with nitrogen to stop the polymerization.

The product could be extracted as a rod from the bottom of the polymerization tube under a nitrogen pressure of 50 mm H9.

The obtained polymer was pale brown and transparent, and had a logarithmic viscosity η1
1 h was 0.50 da/g. Also, T9 is 172℃
The melt viscosity at 7=10 sec-' (280°C) was 46,000 poise.

Examples 2 to 6 Polymerization was carried out in the same manner as in Example 1, except that the charging ratios of terephthalic acid and isophthalic acid were changed as shown in Table 1. The results are shown in Table 1.

(Margin below)

Claims (3)

[Claims] (1) In producing a polyester from an aromatic diol and a dicarboxylic acid, first acylate the aromatic diol using an acylating agent, and then isolate and purify the resulting diacylated product, without A method for producing polyester, which is characterized by polycondensation with dicarboxylic acid under reduced pressure. (2) The production method according to claim 1, wherein the acylation reaction of aromatic diol is carried out in the presence of dicarboxylic acid. (3) The manufacturing method according to claim 1 or 2, which uses a zinc compound as a polymerization catalyst.