JP2662133B2 - Copolyester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymerized polyester, and more particularly to a novel copolymerized polyester containing 2,3-bis (4-carboxyphenyl) quinoxaline as an acid component.

[0002]

2. Description of the Related Art Polyethylene terephthalate (PET)
Utilizing excellent moldability, mechanical properties, and chemical stability, is widely used as fibers, films, engineering plastics, packaging materials, and the like. This PET
Has a melting point of 255 ° C., for example, plastics containing reinforcing fibers can exhibit heat resistance of 200 ° C. or more, but in the case of a non-reinforced molded article, up to a temperature around its glass transition temperature (Tg). However, the heat resistance in this case is extremely insufficient because the Tg of PET is 69 ° C., and an improvement in Tg is desired.

As a measure for increasing the Tg, it is general to copolymerize other components. For example, it is known to use naphthalenedicarboxylic acid or the like instead of the terephthalic acid component of PET, or to use cyclohexane dimethanol or the like instead of the ethylene glycol component. However, these methods are insufficient in the effect of improving Tg. is there.

As a polyester having a high Tg, a wholly aromatic polyester, so-called polyarylate, is known, and a method of copolymerizing an aromatic dihydroxy compound such as bisphenol A can be considered. It is extremely difficult in the production process to copolymerize

[0005]

Accordingly, an object of the present invention is to provide a novel copolymerized polyester having a higher Tg by copolymerizing a small amount of other components with a polyester comprising an aromatic dicarboxylic acid such as PET and an aliphatic diol. Is to do.

[0006]

That is, the present invention provides the following formula (I)

[0007]

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[In the formula (I), Ar represents phenylene, naphthylene or biphenylylene. R represents alkylene and cycloalkylene having 2 to 12 carbon atoms. And a repeating unit represented by the following formula (II):

[0009]

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In the formula (II), X is alkyl having 1 to 6 carbons, cycloalkyl having 5 to 10 carbons, 6 to 12 carbons
And aryl and halogen. n shows the integer of 0-2. R is the same as defined in formula (I). And a reduced viscosity of 0.1 to 50 mol%.
It is a copolyester having 4 or more.

In the above formula (I), Ar is p-phenylene, m-phenylene, 2,6-naphthylene, 2,7-naphthylene, 1,5-naphthylene, 1,4-naphthylene,
4,4′-biphenylylene and 3,3′-biphenylylene can be specifically exemplified. Of these, p-phenylene is preferable as Ar.

R represents an alkylene or cycloalkylene having 2 to 12 carbon atoms, specifically, ethylene, trimethylene, tetramethylene, propylene, neopentylene,

[0013]

Embedded image Etc. can be exemplified. Of these, ethylene is preferred as R.

In the formula (II), X represents alkyl having 1 to 6 carbons, cycloalkyl having 5 to 10 carbons, aryl having 6 to 12 carbons and halogen. More specifically, methyl, ethyl, propyl and the like as alkyl, cyclopentyl and cyclohexyl as cycloalkyl, phenyl, tolyl, naphthyl and the like as aryl, and chlorine as a halogen can be exemplified.

N is an integer of 0 to 2. R is the same as defined in the above formula (I).

The copolymerized polyester of the present invention comprises 99 to 50 mol% of the repeating unit represented by the above formula (I) and 1 to 50 mol% of the repeating unit represented by the above formula (II). If the repeating unit represented by the formula (II) is less than 1 mol%, no improvement in Tg can be expected.

As a method for producing the copolymerized polyester of the present invention, a conventionally known method in the art can be used. That is, the following formula (III)

[0018]

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[In the formula (III), Ar is the same as defined in the formula (I). ] And the following formula (IV) (2,3-bis (4-
Carboxyphenyl) quinoxaline)

[0020]

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[In the formula (IV), X and n are the same as defined in the formula (II). And a ratio corresponding to the copolymerization ratio, and the dicarboxylic acid and / or an ester-forming derivative thereof is polycondensed with a glycol represented by the following formula (V).

[0022]

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[In the formula (V), R is the same as defined in the formula (I). ] Method.

Here, the ester-forming derivative of the dicarboxylic acid represented by the formula (IV) includes alkyl esters,
Aryl esters, acid chlorides and the like can be mentioned.

The specific production method is not particularly limited. For example, a direct polymerization method in which a dicarboxylic acid and a glycol are directly esterified and then polymerized, or a method in which a dialkyl dicarboxylic acid and a glycol are subjected to a transesterification reaction with a glycol. And a transesterification method for polymerization.

The copolyester of the present invention is a phenol / tetrachloroethane mixed solvent (60/40 by weight).
Medium, the reduced viscosity measured at a concentration of 1.2 g / dl and a temperature of 35 ° C. must be 0.4 or more. The reduced viscosity is 0.
If it is less than 4, the mechanical properties of the obtained molded product will be insufficient.
The reduced viscosity is preferably 0.5 or more, more preferably 0.6 or more.

[0027]

The copolymerized polyester of the present invention has a bulky diphenylquinoxaline structure as a copolymerization component. By copolymerizing in a small amount, the Tg of the polymer before copolymerization can be greatly increased. . Further, a polymer having a desired Tg can be easily obtained depending on the copolymerization ratio. Further, as a production method, the same melt polycondensation as that of ordinary polyester such as PET is possible.

[0028]

EXAMPLES The present invention will be described below with reference to examples, where "parts" means parts by weight. Tg was measured by DSC at a rate of temperature rise of 10 ° C./min.

[0029]

EXAMPLES 1-4 AND COMPARATIVE EXAMPLE 1 Dimethyl terephthalate and a predetermined amount of 2,3-bis (4-carbomethoxyphenyl) quinoxaline shown in Table 1, ethylene glycol 15
5 parts and 0.15 part of tetrabutyl titanate were placed in a reaction vessel equipped with a distilling system via a stirrer and a rectification column, and
The mixture was heated to 20 ° C., and methanol produced by the transesterification was distilled off. After about 60 parts of methanol was distilled off, the reaction mixture was placed in a reaction vessel equipped with a stirrer and a vacuum distilling system, and the mixture was heated at 280 ° C. in a nitrogen stream at normal pressure for 30 minutes.
Minutes, then under reduced pressure of about 20 mmHg for 15 minutes,
The reaction was performed under reduced pressure of mmHg for about 60 minutes. Table 1 shows the reduced viscosity (ηsp / c) and Tg of the obtained polymer. FIG. 1 shows the IR spectrum of the polymer obtained in Example 1.

As a comparison, a polyethylene terephthalate homopolymer is also described. It can be seen that the copolymerized polyester of the present invention has a high Tg.

[0031]

[Table 1]

[Brief description of the drawings]

FIG. 1 is an IR spectrum of a polymer obtained in Example 1.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-256827 (JP, A) JP-A-55-75424 (JP, A)

Claims (1)

(57) [Claims] 1. A compound represented by the following formula (I): [In the formula (I), Ar represents phenylene, naphthylene, or biphenylylene. R represents alkylene and cycloalkylene having 2 to 12 carbon atoms. A repeating unit 9 represented by
9 to 50 mol% and the following formula (II): [In the formula (II), X is alkyl having 1 to 6 carbons, 5 carbons.
And 10 to 10 cycloalkyl, aryl having 6 to 12 carbon atoms and halogen. n shows the integer of 0-2. R is the same as defined in formula (I). ] Is a repeating unit 1
A copolymerized polyester consisting of モ ル 50 mol% and having a reduced viscosity of 0.4 or more.