JP2702334B2 - Aromatic polyester and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel aromatic polyester. More specifically, the present invention relates to a novel aromatic polyester and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, polyethylene terephthalate (P
Fibers and films of aromatic polyesters such as ET) and polyethylene naphthalate (PEN) are produced by melt-spinning or melt-forming each aromatic polyester and then heat-drawing to produce fibers and films having a high elastic modulus. be able to. However, in recent years, with the advancement of industrial technology, there has been an increasing demand for materials having higher physical and chemical properties.

On the other hand, many aromatic polyesters (liquid crystal polyesters) exhibiting anisotropy when melted by introducing a rigid unit into a molecular chain have been developed. Since these are likely to be uniaxially oriented in the flow direction during molding, the anisotropy of the molded article tends to be extremely strong, and it is almost impossible to produce a biaxially oriented film by an ordinary method. Further, although the uniaxially oriented fiber has a high modulus of elasticity, it generally has a drawback of low elongation at break.

[0004]

Accordingly, an object of the present invention is to provide a novel fragrance which can be melt-molded, exhibits optical isotropy under melting, and has excellent moldability, mechanical properties, heat resistance and the like. To provide an aromatic polyester. Another object of the present invention is to provide a method for efficiently producing the novel aromatic polyester.

[0005]

That is, the present invention provides a compound represented by the following formula (I):

[0006]

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[Here, n is an integer of 2 to 10. ]
Having at least 50 mol% of a repeating unit represented by the formula and having an intrinsic viscosity of 0.4 or more as measured at 35 ° C. using a mixed solvent of P-chlorophenol / tetrachloroethane (40/60 weight ratio). Polyester and the following formula (II)

[0008]

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[Where R is a hydrogen atom, a lower alkyl group,
It is a cycloalkyl group or a phenyl group which may have a substituent. Wherein the mixture of an aromatic dicarboxylic acid or an ester derivative thereof and an aliphatic glycol having 2 to 10 carbon atoms is reacted by heating and melt-polycondensed. is there.

Hereinafter, the present invention will be described in detail. In the present invention, the aromatic polyester constituting the main requirement is a substantially linear polyester having at least 50 mol% of the repeating unit represented by the above formula (I).
Here, the repeating unit represented by the above formula (I) is preferably at least 70 mol%, particularly preferably 80 mol%.
It is.

The intrinsic viscosity of the aromatic polyester according to the present invention is 0.4 or more, preferably 0.5 or more.
If the intrinsic viscosity is less than 0.4, the mechanical properties of a molded article obtained from the polyester are not sufficient.

In the present invention, the aromatic polyester mainly composed of the repeating unit represented by the above formula (I) is the same as the aromatic dicarboxylic acid represented by the above formula (II) or an ester derivative thereof, which has 2 to 2 carbon atoms. It is produced by heat-reacting a mixture with 10 aliphatic glycols and subjecting it to melt polymerization.

The method for synthesizing such an aromatic dicarboxylic acid or an ester derivative thereof includes, for example, (i) 6-oxy-2-naphthoic acid and / or an alkali metal salt of the ester and an excess 1,2-dihalogenated ethane. 6- (β-haloethoxy) obtained by reacting
A method of reacting 2-naphthoic acid and / or an ester thereof with an alkali metal salt of P-hydroxybenzoic acid and / or an ester thereof; (ii) an excess amount of an alkali metal salt of P-hydroxybenzoic acid and / or an ester thereof The resulting P- (β-haloethoxy) benzoic acid and / or an ester thereof are reacted with a 1,2-dihalogenated ethane and an alkali metal salt of 6-oxy-2-naphthoic acid and / or an ester thereof. The method can be exemplified.

In the method of the present invention, the acid or ester of the above formula (II) is used as the dicarboxylic acid component, and other dicarboxylic acids, oxycarboxylic acids or ester-forming derivatives thereof may be used in combination therewith. .

As another dicarboxylic acid, for example, the following formula (III): HOOC-R ¹ -COOH (III) wherein R ¹ is an alkylene group having 2 to 10 carbon atoms, a cycloalkylene group or an arylene group. ] Is used. Examples include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, adipic acid, azelaic acid, sebacic acid, cyclohexane-1,4-dicarboxylic acid, and the like.

Similarly, other oxycarboxylic acids include, for example, the following formula (IV): HOOC—R ² —OH (IV) wherein R 2 is an alkylene group having 2 to 10 carbon atoms, a cycloalkylene group, an arylene group, Or a phenylene-oxyalkylene group. ] Is used.
Examples thereof include oxybenzoic acid, β-hydroxyethoxybenzoic acid, hydroxynaphthoic acid, β-hydroxyethoxynaphthoic acid, hydroxycaproic acid, and 4-hydroxycyclohexanecarboxylic acid.

In the present invention, the ester-forming derivative used for the carboxylic acid component is a compound capable of reacting with an aliphatic glycol and producing an ester as a result of the reaction, for example, a lower alkyl ester having 1 to 6 carbon atoms. Or an ester such as a phenyl ester.

As the dicarboxylic acid, a dicarboxylic acid represented by the above formula (II) or an ester thereof and another dicarboxylic acid;
When oxycarboxylic acids or their ester-forming derivatives are used in combination, other dicarboxylic acids and the like are preferably less than 50 mol% of the total acid components, more preferably less than 30 mol% of the total acid components, Of all the acid components 2
Less than 0 mol% is used.

In the method of the present invention, as the glycol component, an aliphatic glycol having a glycol main chain having 2 to 10 carbon atoms is used, and other diols may be used together with the glycol component.

The glycol main chain refers to the shortest chain portion connecting two hydroxyl groups of glycol. The glycol mainly used in the present invention has the following formula (V)

[0021]

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[Where n is an integer of 2 to 10]. Specific examples include ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol and the like. Of these, ethylene glycol is particularly preferred.

The diols which may be used in combination include neopentylene glycol, propylene glycol, cyclohexane dimethylol, hydroquinone, resorcinol, 2,6-dihydroxy-naphthalene, 4,4'-
Dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl)
Ethyl and the like.

When a diol as the other glycol component is used in combination, the other diol is preferably less than 50 mol% of the total glycol component, more preferably less than 30 mol% of the total glycol component.
In particular, less than 20 mol% of the total glycol component is used.

According to the above invention, the dicarboxylic acid component mainly composed of the dicarboxylic acid or the ester thereof represented by the above formula (II) and the glycol component mainly composed of the aliphatic glycol having 2 to 10 carbon atoms are reacted by heating. Thus, the aromatic polyester of the present invention can be produced. The reaction is usually carried out in the presence of a catalyst, using the glycol component in an amount of 1.1 to 3 times the molar amount of the acid component.

As the catalyst, for example, sodium, potassium, lithium, calcium, magnesium, barium,
Carriers such as tin, strontium, zinc, iron, aluminum, cobalt, lead, nickel, titanium, manganese, antimony, oxides, hydrides, hydroxides, halides, inorganic and organic acid salts, complex salts, double salts, and alcoholates ,
Phenolates and the like can be mentioned, and these may be used in combination of two or more. In particular, antimony compounds, germanium compounds, titanium compounds and the like are preferably used as the condensation catalyst. Such a catalyst has a
About 0.5 mol% is preferably used. Preferred condensation temperatures are between the melting point of the resulting polymer and 350 ° C, more preferably between the temperature of the melting point + 5 ° C and 330 ° C.

Compounds having one ester-forming functional group such as benzoic acid and benzoyl benzoic acid in a range where the obtained aromatic polyester is substantially linear when the condensation reaction is carried out; glycerin , A compound having three or more ester-forming functional groups such as pentaerythritol, trimellitic acid, and pyromellitic acid; or an ester-forming derivative thereof in the presence of a copolymer. The compound having three or more ester-forming functional groups can be used, for example, in an amount of 0.2 mol% or less based on all acid components.

Thus, according to the present invention, a substantially linear dicarboxylic acid and / or ester represented by the above formula (II) is used as a main acid component and an aliphatic glycol having 2 to 10 carbon atoms is used as a main glycol component. An aromatic polyester of the present invention is provided.

The aromatic polyester of the present invention has the following formula (I)

[0030]

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[Here, n is an integer of 2 to 10. ]
Or a homopolyester or copolyester mainly comprising a repeating unit represented by

The aromatic polyester of the present invention can be easily processed and molded into fibers, films, molded articles, etc., and can be used in various shapes, and its industrial significance is extremely large.

For example, a fiber is prepared from the aromatic polyester of the present invention as follows: Aromatic polyester is dried and dried at a temperature above the polymer crystalline melting point (Tm: ° C.) but below 350 ° C., preferably 330 ° C. Melted at a temperature lower than 3 ° C., more preferably lower than 320 ° C.
It is formed into the following undrawn fibrous material. Next, the unstretched fibrous material is stretched and heat-treated. When the glass transition point of the polyester is Tg (° C.), the stretching is (Tg−10) ° C.
(Tg + 30) It is preferably carried out first at a temperature in the range of (C) (one-stage stretching), and further from the one-stage stretching temperature to (Tm-10).
It is preferable to perform stretching or heat treatment at a temperature in the range of ° C. The stretching ratio is generally about 3 to 10 times as a whole.

Similarly, films are prepared from the aromatic polyesters of the present invention as follows: the aromatic polyester is dried and dried at a temperature above the polymer melting point (Tm), but below 350 ° C., more preferably Is melted at a temperature below 330 ° C., extruded from a film forming die, and subsequently quenched by contact on a rotating drum maintained at a temperature below the polymer glass transition temperature (Tg). The unstretched film thus obtained has excellent properties in heat resistance, hydrolysis resistance and the like as it is, but the unstretched film is uniaxially or biaxially oriented for the purpose of further improving the performance. It can also be stretched. Stretching is performed at a temperature in the range of (Tg−10) ° C. to (Tg + 50) ° C. at an area magnification of 2 times or more, further 5 times or more, particularly 8
It is preferable to carry out the process so that the number is twice or more. The stretching method is
In the case of biaxial stretching, it may be sequential or simultaneous. The stretched film is preferably stretched or heat-treated at a temperature ranging from a stretching temperature to (Tm-10) ° C.

The aromatic polyester of the present invention includes
Stabilizers such as other thermoplastic polymers, ultraviolet absorbers, etc. as appropriate, antioxidants, plasticizers, lubricants, flame retardants, mold release agents, pigments, nucleating agents, fillers or glass fibers, carbon fibers, asbestos, etc. If necessary, a reinforcing material such as the following may be blended.

[0036]

The aromatic polyester of the present invention is a crystalline polymer excellent in moldability and a high-performance polyester having high mechanical properties, heat resistance, chemical resistance and the like. Further, according to the method of the present invention, the aromatic polyester,
It is industrially advantageous because it can be produced efficiently and by a melt polymerization method.

[0037]

The present invention will be described below in detail with reference to examples. The melting point of the polymer was measured by a differential thermal analysis (DSC) at a heating rate of 10 ° C./min. The intrinsic viscosity was measured at 35 ° C. using P-chlorophenol / tetrachloroethane (mixed solvent (weight ratio: 4/6)). The present invention is not limited by these examples.

[0038]

[Reference example]

Synthesis of 2-[(P-carboxyphenoxy) ethoxy] -naphthalene-6-carboxylic acid ethyl ester 152 g of methyl P-hydroxybenzoate and 413 g of dibromoethane were added together to 1000 ml of ethanol in which 25.3 g of sodium metal was previously dissolved. The mixture was placed in a 3 liter three-necked flask and reacted under heating for 18 hours while stirring under reflux conditions under a nitrogen stream. After cooling, the deposited precipitate was separated by filtration, and the lower layer of the liquid layer separated into two layers was taken.
200 ml of an IN-NaOH aqueous solution was added thereto for washing. Then, it was concentrated to remove unreacted dibromoethane, then 1000 ml of hexane was added, the insoluble portion was removed by filtration, the hexane solution was concentrated, and the solution was distilled under reduced pressure.
-(2-Bromoethoxy) -benzoic acid ethyl ester 9
2 g were obtained. This compound has a boiling point of 163 ° C. (0.1 mmH
g), melting point 43 ° C.

Next, 27.3 g of the obtained methyl 4- (2-bromoethoxy) -benzoate and 32.5 g of methyl oxynaphthoate were added together with 500 ml of ethanol in which 6.43 g of sodium hydroxide was previously dissolved in 1 liter. Was heated and reacted for 7.5 hours under reflux conditions while stirring under a nitrogen stream. The precipitate formed during the reaction was filtered and collected after cooling.
This was washed with water and then with methanol and further recrystallized from chloroform to obtain 23.5 g of a product. This compound had a melting point of 140-145 ° C. This compound was confirmed to be the target compound by IR spectrum, NMR spectrum, elemental analysis and MS spectrum.

[0040]

Example 1 (Polymerization of Polyester) 2-[(P-
Carboxyphenoxy) ethoxy] -naphthalene-6-
5. 20.4 g of ethyl carboxylate, ethylene glycol
8 g and 4.5 mg of titanium tetrabutoxide were charged into a flask equipped with a stirring blade and a rectification column, and heated and reacted at 195 ° C. while distilling off ethanol produced outside the system. After 3 hours, almost the theoretical amount of ethanol had distilled off.

Subsequently, the reaction product was transferred to a flask equipped with a stirrer and a distilling system, and the temperature of the reaction system was gradually raised from 260 ° C., and was raised to 280 ° C. after 30 minutes. The reaction was further heated at 280 ° C. for 30 minutes. During this time, distillation of ethylene glycol was observed.

Next, the pressure in the reaction system was gradually reduced, and finally the system was shifted to a high vacuum of 0.5 mmHg. In this state, the mixture was reacted for 90 minutes to obtain a polymer. The obtained polymer was a crystalline polyester having an intrinsic viscosity of 0.78 and a melting point of 237 ° C.

[0043]

Example 2 The polymer obtained in Example 1 was dried and dried.
It was melted at 60 ° C., extruded from a cap having a nozzle diameter of 0.3 mm, and wound at a linear speed of 400 m / min.
Then, the undrawn yarn was stretched 4.7 times at 130 ° C., and subsequently, stretched 1.4 times (two-stage drawing) at 160 ° C. to obtain a 3.7 denier drawn yarn. When a tensile test was conducted under the conditions of a gauge length of 25 mm and a tensile speed of 20 mm / min, the fiber properties were a tensile strength of 5.7 g / de, a breaking elongation of 9.9%, and a Young's modulus of 267 g / de.

Claims (3)

(57) [Claims] (1) The following formula (I): [Here, n is an integer of 2 to 10. Having at least 50 mol% of a repeating unit represented by the formula [I] and having an intrinsic viscosity of at least 0.4 measured at 35 ° C using a mixed solvent of P-chlorophenol / tetrachloroethane (40/60 weight ratio). Polyester. 2. The aromatic polyester according to claim 1, wherein n is 2 in the formula (I). 3. A compound represented by the following formula (II): [Where R is a hydrogen atom, a lower alkyl group, a cycloalkyl group, or a phenyl group which may have a substituent. ]
2. The process for producing an aromatic polyester according to claim 1, wherein a mixture of an aromatic dicarboxylic acid or an ester derivative thereof represented by the formula (1) and an aliphatic glycol having 2 to 10 carbon atoms is reacted by heating and melt-polycondensed. .