JPH01161014A - Manufacture of copolymerized polyester - Google Patents

Abstract

PURPOSE:To produce a copolymerized polyester excellent in heat resistance at low cost, by reacting a specific aromatic hydroxycarboxylic acid, a polyester, a diol, a dicarboxylic acid, and acetic anhydride under specified conditions. CONSTITUTION:An aromatic hydroxycarboxylic acid of formula I (e.g., p- hydroxybenzoic acid), a polyester of formula II of a condensate obtained from an aromatic dicarboxylic acid and an alkylene glycol (e.g., polyethylene terephthalate), an aromatic diol of formula III (e.g., 4,4'-dihydroxybiphenyl), an aromatic dicarboxylic acid of formula IV (wherein Ar1-Ar4 are each a divalent aromatic group; and R1 is divalent alkylene) (e.g., terephathalic acid), and acetic anhydride are prepared. When these components are reacted to produce a polyester copolymer, part or the whole of the polyester of formula II is post-added to the reaction system wherein the temperature is 150 deg.C or above, thereby producing the aimed copolymerized polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a copolyester having good heat resistance, which can be synthesized only by melt polymerization and using low-cost raw materials.

<Prior art> Polyester unit formed from an aromatic human oxycarboxylic acid, a t-position polyester unit formed from an aromatic diol and an aromatic dicarboxylic acid, and a polyester unit formed from an alkylene glycol and an aromatic dicarboxylic acid. Polymerized polyester is disclosed in Japanese Patent Application Laid-Open No. 51-8395.
This method is disclosed in Japanese Patent Application Laid-Open No. 58-84821, etc.

JP-A-51-8395 and JP-A-58-848
The copolymerized polyester disclosed in Publication No. 21 is composed of a, an acetylated product of an aromatic hydroxycarboxylic acid, b, an acetylated product of a polyester obtained by condensing an aromatic dicarboxylic acid and an alkylene glycol, and a C1 aromatic diol, and d,
It is described that it is produced by a method consisting of a first step of charging and condensing an aromatic dicarboxylic acid, and a second step of reducing the pressure of the reaction system to give it a high molecular weight.

Additionally, JP-A-62-41220 discloses (i) aromatic hydroxycarphonic acid, (ii) polyester formed by condensing aromatic dicarboxylic acid and alkylene glycol;
Lit) After reacting (it) and (i) using a very small amount of aromatic diol and (iv) acetic anhydride, <iv
) has been disclosed. A method for producing a copolymerized polyester is disclosed, which requires acetylation.

<Problems to be Solved by the Invention> However, in the production methods described in JP-A-51-8395 and JP-A-58-84821, (1) aromatic droxycarboxylic acid and (2) aromatic diol are separated in advance. It is necessary to induce an acetylated product in the process, and the polymer cannot be obtained at low cost. Also, JP-A-62-
In the production method described in Japanese Patent No. 41220, (1) the aromatic dicarboxylic acid is not copolymerized, so that only a polymer with low heat resistance and insufficient molecular weight is obtained. Furthermore, (iv)
Since acetic anhydride is added later, it is necessary to cool the reaction system midway through, which makes the reaction time long and the reaction complicated.

An object of the present invention is to stably produce a copolyester in large quantities that uses non-acetylated monomers and has good heat resistance and high mechanical properties.

Means for Solving the Problems> That is, the present invention provides: (1) an aromatic hydroxycarboxylic acid having the following structure ji''L position CI), (2) the following structural unit (II
) and a polyester formed by condensing an aromatic dicarboxylic acid and an alkylene glycol having the following structural unit (I
II) aromatic diol having the ■ following'! When producing a copolyester by reacting an aromatic dicarboxylic acid having an FI structural unit (IV) and (1) acetic anhydride, (1) condensing an aromatic dicarboxylic acid having the following structural unit (If) with an alkylene glycol. This is a method for producing a copolymerized polyester, which is characterized in that part or all of the polyester is post-added to a reaction system at a temperature of 150° C. or higher.

HOA r I COOH (I ) + ORO
CA r 4 CO) n(I[)HOA r 2
0 H(III) HOOCA r 3 COOH(IV) (However, A
r to Ar4 are divalent aromatic groups, R1 is a divalent alkylene group, and Ar and 1 to Ar4 may be the same or different from each other. ) The copolymerized polyester produced in the present invention has the above structural units (I), (II), and (I[[). Ar ~A r 4 is 2
They are valent aromatic groups, and may be the same or different from each other, and a mixture of them is also possible. Preferably used A
C11° may be used as r1, and 4,4′-biphenylene group, p-phenylene group, and mixtures thereof are particularly preferred.

Furthermore, preferably used A r 3 and A r 4
X represents a hydrogen atom or a chlorine atom.

Moreover, R1 is a divalent alkylene group, especially +CH2
+2 is preferred.

The copolymerized polyester produced in the present invention is a polyester raw material consisting of an aromatic hydroxycarboxylic acid, an aromatic diol, and an aromatic dicarboxylic acid having the following structural unit (IV), or the above-mentioned A polyester raw material consisting of part of a polyester formed by condensing dicarboxylic acid and alkylene glycol is reacted with ■ acetic anhydride, and part or all of the polyester formed by condensing aromatic dicarboxylic acid and alkylene glycol is heated at 150°C. It is manufactured by requiring post-addition to the reaction system under the above temperature conditions.

■Aromatic hydroxycarboxylic acid and ■Aromatic diol■
The corresponding acetyl compound is formed through acylation with acetic anhydride, and the polyester formed by condensing aromatic dicarboxylic acid and alkylene glycol forms the corresponding polyester fragment through acid decomposition, and these and dicarboxylic acid are deacetated. The reaction occurs sequentially and finally becomes a macromolecular polymer.

In the production method of the present invention, the raw materials (■) to (■) are usually ■,
■ is in the range of 5 to 95 mol%, ■ is in the range of 5 to 95 mol%, ■ is in the range of 5 to 95 mol%, and ■ is in the range of 0.7 to 1.3 with respect to the total of 100 mol% of ■ and ■. It is preferably prepared in a molar range.

From the point of view of the heat resistance of the polyester to be manufactured, in particular,
[■+■] is 77 for the total of 100 mol% of and
~95 mol%, ■ is in the range of 5 to 23 mol%, ■/■ molar ratio is in the range of 75/25 to 9515, ■ is 0 relative to ■
．． It is preferably charged in a range of 9 to 1.1 moles.

However, ■ is characterized by the average of repeating units. Especially when ■ is polyethylene terephthalate, the molecular weight is 192.1
Convert the preparation site as 7.

In addition, acetic anhydride has 1
．． It is used in an amount of 0 to 1.5 times by mole, preferably 1.05 to 1.2 times by mole.

In the production method of the present invention, (1) is preferably added in an amount of 5% by weight or more, preferably 50% by weight or more, and 10% by weight or more.
It is most preferable to add 0x1, ie, all of them later.

The feature of the present invention is that, by adding part or all of (2) of the above-mentioned (1) to (2) to the reaction system later, it is possible to synthesize a large amount of copolyester, compared to the case where all of the above-mentioned (1) to (4) are charged at once. The objective is to show an extremely high improvement effect on production stability.

The reason for this is that when ■ is introduced into a reaction system with a temperature of 150°C or higher, ■ is agglomerated and fused during the reaction, especially when the particle size of ■ is large, such as when it is a deep layer. This solves the inconvenience in the production process where stirring becomes impossible.

The present invention also provides a practical and stable production process, particularly for large scale polymer synthesis. The temperature at which (1) is added is 150℃, preferably 200-2
If the mixture of the 0 reaction system at 50°C is below 150°C, the decomposition reaction (2) will not be rapid, and polymer aggregation and fusion will occur. The decomposition reaction of ■ occurs more quickly at higher temperatures, so 2
Addition at 00-250°C is preferred.

In the production method of the present invention, there is no particular restriction other than that the above operations are essential, and raw materials other than ■ may be charged all at once. (2) A method of post-adding to the reaction system can also be mentioned. In this case, there is an advantage that a copolyester can be obtained in which the decrease in molecular weight of the polymer upon heating is particularly reduced.

There is no particular restriction on the order of addition of ■ and ■.
Even if you add ■ to the reaction system of (■〒■±■) and then add ■, even if you add ■ to the reaction system of (■〒■±■) and then add ■, you can add ■ and ■ at the same time. It doesn't matter.

Although the reaction in the fusing method of the present invention is not certain,
This is considered as follows.

First, ■ and ■ undergo acylation with ■ acetic anhydride at a temperature below 150°C, and these decompose ■ at a higher temperature.
Fractionate. Further, polycondensation including (■) results in a high molecular weight.

In addition, as a preferred production method, (1) aromatic hydroxycarboxylic acid, (2) aromatic diol, and (2) acetic anhydride are charged into a reaction vessel and heated at 80°C to 30'C1 under a nitrogen stream.
Preferably, the acetylation reaction is carried out at 100°C to 250°C. The acetylation reaction progresses and a certain amount of acetic acid is distilled off! Then, the reaction system is heated to 150°C or higher, preferably 200 to 250°C, and (2) a polyester obtained by condensing an aromatic dicarboxylic acid and an alkylene glycol is introduced into the reaction system.

After further progressing the reaction, further at 260-330°C.
1. Preferably, there is a method of obtaining a polymer by polymerizing under vacuum at 290 to 320°C.

In addition, the reaction in the production method of the present invention proceeds even without a catalyst, but tinnous acetate, ll11:acid zinc, antimony acetate, antimony dioxide, te1butyl titanate,
In some cases, it may be preferable to add a metal compound such as sodium acetate, potassium chloride, or magnesium metal.

Further, the melt viscosity of the copolymerized polyester of the present invention is 10
~15,000 boiz is preferred, especially 20-5,00
0 voice is more preferable.

Note that this melt viscosity is a value measured using a Koka type flow tester at (liquid crystal starting temperature +40°C) and a shear rate of i, 000 (1/sec) under a strip 1'F. - way, this same 1
[The logarithmic viscosity of the synthetic polyester is (0°1g/dJ4 degrees,
measurable in pentafluorophenol at 60'C), preferably 0.5-5 dJl/g, 1.0-3
．． Od! J/g is particularly disappointing.

In addition, when polycondensing the copolymerized polyester produced in the present invention, adipic acid, azelaic acid,
Aliphatic dicarboxylic acids such as sebacic acid and dodecanedioic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexane dimeta It is possible to further copolymerize υj group fats such as tools, alicyclic diols, etc. within a small proportion that does not impair the object of the present invention.

The production method of the present invention is one in which a polymer with a high degree of polymerization can be obtained using only the melt polymerization method, and the polymer produced thereby exhibits good optical anisotropy, mechanical properties, and heat resistance,
Extrusion molding - Can be used in conjunction with ordinary melt molding such as injection molding and blow molding, and can be used to produce fibers, films, three-dimensional molded products,
It can be processed into containers, hoses, etc.

In addition, the strength of the molded article obtained in this manner can be increased by heat treatment, and the elastic modulus may also be increased. This heat treatment can be carried out by heat treating the molded article in an inert atmosphere (eg nitrogen, argon, helium or water vapor) or in an oxygen-containing atmosphere (eg air) at a temperature below the melting point of the polymer. This heat treatment may or may not be under tension, and can be carried out for several tens of minutes to several days.

For the copolymerized polyester produced in the present invention, reinforcing materials such as glass fiber, carbon fiber, and asbestos, fillers, nucleating agents, pigments, antioxidants, stabilizers, plasticizers, lubricants, elegance agents, and flame retardants, etc. Additives and other thermoplastics can be added to impart desired properties.

<Example> The present invention will be further explained below with reference to one example.

Example 1 In a 51 reactor equipped with a stirrer and a motor, p-hydroxyammonium fragrant acid 1036r (7.5 mol), = 1
．． 186 g (1 mol) of 4-dihydroxybiphenyl,
Terephthalic acid 166g (1 mol), acetic anhydride 1067g
g (10.44 mol) and reacted at 145°C for 1.5 hours. During this period, acetic acid distillation of approximately 50°C was observed. After this, the temperature was increased at a rate of 50°C per hour to 240°C.
Keeping the temperature constant at °C, the intrinsic viscosity is approximately 0.6 in 30 minutes.
Polyethylene terephthalate h288g (0,07
5 mol) was added. As the mixture was added, the reaction was stirred vigorously.

The temperature was further increased to 300° C. over 1 hour, the pressure was reduced to 0.5 mmHg over the next 1 hour, and polymerization was continued for another 1 hour to complete the reaction.

0゜Ig in pentafluorophenol of the obtained polymer
/dj The logarithmic viscosity at 60°C is 1.80dj /
It was g. In addition, the theoretical structural formula of this polymer %Formula%
036 g (7,5 mol), 4,4-dihydroxybiphenyl 180 g (1 mol), anhydrous i! il: acid 10
67ir (to, 44 mol) and heated to 1.15°C.
The reaction was carried out for 1.5 hours. During this time, about 5 Qcc of acetic acid distillation was observed. After this, 166 g of prephthalic acid (1
mol) was added and the temperature was raised at a rate of 50°C per hour.
The temperature was kept constant at 35°C, and the same polyethylene terephthalate 288+r (0,0
75 mol) was added.

As the mixture was added, the reaction was stirred vigorously. 30 more
1 hour to 0'C? Let it warm up, and in the next hour it will reach 0.
The pressure was reduced to 5 mmHg and the polymerization was further carried out for 1 hour to complete the reaction. The logarithmic viscosity of this polymer was 1.84 dfJ/g.
Met.

Comparative Example 1 P-droxybenzoic acid, 4,
4''-dihydroxybiphenyl, terephthalic acid, acetic anhydride, and polyethylene terephthalate were charged in the same amounts as in Example 1, and after stirring at 145 °C for 1 hour, the stirring load increased and stirring became impossible. When the reactor was shut down and cooled, the reactor was disassembled and a pellet of polyethylene terephthalate was fused to the bottom of the reactor and wrapped around the stirring spring.

From the above results, it is difficult to stably obtain a copolymerized polyester in large quantities using the method of Comparative Example 1 in which the polymer raw materials were added all at once. It is clear that the results can be obtained stably.

<Effects of the Invention> By the method of the present invention, it has become possible to stably produce a copolyester with good heat resistance in large quantities using low-cost raw materials.

Claims (1)

[Scope of Claims] [1] An aromatic hydroxycarboxylic acid having the following structural unit (I), [2] A polyester obtained by condensing an aromatic dicarboxylic acid and an alkylene glycol having the following structural unit (II), and [3 ] When producing a copolymerized polyester by reacting an aromatic diol having the following structural unit (III), [4] an aromatic dicarboxylic acid having the following structural unit (IV), and [5] acetic anhydride, [2] A method for producing a copolymerized polyester, which comprises adding part or all of a polyester obtained by condensing an aromatic dicarboxylic acid having the following structural unit (II) and an alkylene glycol to a reaction system at a temperature of 150°C or higher. . HO-Ar_1-COOH(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) HO-Ar_2-OH(III) HOOC-Ar_3-COOH(IV) (However, Ar_1 to Ar_4 are divalent aromatic groups, R_1
is a divalent alkylene group, and Ar_1 to Ar_4 may be the same or different from each other. )