JPH06200028A - Copolyester - Google Patents

Abstract

PURPOSE:To obtain a copolyester which is excellent in moldability, can be molded into, e.g. a film excellent in mechanical properties, heat resistance and flame retardancy, and can be used for magnetic recording medium, electrical insulation material, packaging materials, etc. CONSTITUTION:A polyester comprising repeating units of formula I and repeating units of formula II wherein Ar1, Ar3 and Ar4 are each a bivalent aromatic residue; Ar2 is a tetravalent aromatic residue; R1 and R2 are each a 1-12C linear branched or cyclic bivalent aliphatic group; and X and Y are the molar fractions of the repeating units of formulas I and II, respectively, and satisfy the formulas: 0.01<=X/(X+Y)<=0.50.

Description

Detailed Description of the Invention

[0001]

The present invention relates to mechanical properties such as rigidity,
The present invention relates to a polyester having excellent heat resistance, flame retardancy, and moldability, and provides a polyester that can be processed into films, fibers, molded products and the like.

[0002]

2. Description of the Related Art In recent years, miniaturization in the field of electric and electronic equipment,
With the progress of weight reduction, not only downsizing of materials to be used but also simplification, shortening of process and speeding up have been demanded for heat resistance and high strength. Aromatic polyesters typified by polyethylene terephthalate have been conventionally used in these fields, but there is a limit in mechanical properties and heat resistance, and it has become difficult to satisfy the above required properties. Therefore, for high heat resistance and high rigidity, copolymerization of liquid crystal polyester and liquid crystal components (for example, “High-performance aromatic polymer materials” edited by Polymer Society of Japan (Maruzen)) is being studied.

[0003]

However, although the liquid crystal polymer has relatively high heat resistance and high rigidity among the molten polymers, it has a problem that it is strongly oriented in the flow direction and the strength in the direction perpendicular thereto is lowered. However, the moldability into a film that needs to be biaxially stretched in the machine direction and the width direction was poor. On the other hand, even if an attempt is made to copolymerize a rigid component that contributes to the expression of liquid crystallinity with an aromatic polyester in a small amount that does not exhibit liquid crystallinity, the degree of polymerization does not increase and a polymer having sufficient strength cannot be obtained. There was a problem. An object of the present invention is to solve such problems and provide a copolyester having excellent mechanical properties such as rigidity, heat resistance, and moldability.

[0004]

The present invention provides units I and II represented by the following formula.

[Chemical 2] {Wherein Ar ₁ , Ar ₃ and Ar _{4 each} independently represent a divalent aromatic residue, and Ar ₂ represents a tetravalent aromatic residue,
R ₁ and R ₂ independently represent a linear, branched, or cyclic divalent aliphatic having 1 to 12 carbon atoms. X and Y represent the mole fractions of units I and II, respectively, and satisfy the following formula (1). 0.01 ≦ X / (X + Y) ≦ 0.50 (1)}.

Ar ₁ , Ar ₃ and Ar ₄ of the above units I and II constituting the copolyester of the present invention each independently represent a divalent aromatic residue, preferably having 6 to 24 carbon atoms. It is an aromatic ring. Each of these aromatic rings is 1
Not only one, but also two or more may be formed, and hydrogen on the aromatic ring may be substituted with halogen, an alkyl group having 1 to 3 carbon atoms, a phenyl group, a cyano group, a nitro group, or the like. When there is one aromatic ring, para and meta structures are preferable, and when there are two or more aromatic rings, divalent aromatic residues corresponding to these are preferable, and for example, the following structures are more preferable.

[Chemical 3] (In the formula, those in which hydrogen on the aromatic ring is substituted with halogen, an alkyl group having 1 to 3 carbon atoms, a phenyl group, a cyano group, a nitro group, etc.)

More preferably, it is of para-type,

[Chemical 4] And so on.

Ar ₂ represents a tetravalent aromatic residue, and preferably has the following structure.

[Chemical 5] On the other hand, R ₁ and R ₂ are independently a straight chain having 1 to 12 carbon atoms,
It is a branched or cyclic divalent aliphatic residue, and preferably a linear or branched alkylene group having 2 to 8 carbon atoms, a cycloalkylene group having 4 to 10 carbon atoms, or 6 carbon atoms.
To 12 cycloalkylenedialkylene groups, more preferably

[Chemical 6] Etc., in particular,

[Chemical 7] Is preferred.

Further, the mole fraction of the unit I constituting the copolyester of the present invention is X, and the unit II is the unit II.
X is 0.01 ≦ X / (X +
It is necessary that Y) ≦ 0.50. X /
When (X + Y) <0.01, the mechanical properties and heat resistance, which are the effects of the present invention, are not sufficiently improved, and X / (X + Y)>
When it is 0.50, the melting point may exceed 350 ° C. and molding may not be possible, or liquid crystal properties may start to be expressed and strongly oriented in one direction, resulting in poor moldability for a film or the like. Preferably 0.0
1 ≦ X / (X + Y) ≦ 0.40, more preferably 0.0
1 ≦ X / (X + Y) ≦ 0.35.

Next, a method for producing the copolyester of the present invention will be described. First, a dicarboxylic acid (II
I)

[Chemical 8] (Wherein Ar ₁ , Ar ₂ and Ar ₃ are the same as defined above) or an ester derivative thereof is

[Chemical 9] (Wherein Ar ₁ and Ar ₃ are the same as defined above), for example, methyl of aminocarboxylic acid such as P-aminobenzoic acid, m-aminobenzoic acid and 2-amino-6-naphthoic acid. One or more of ester or ethyl ester derivatives,

[Chemical 10] (Wherein Ar ₂ is the same as the above definition), a tetracarboxylic dianhydride, for example, pyromellitic dianhydride,
2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylenetetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic acid dianhydride, or hydrogen on these aromatic rings is a halogen or alkyl group. It can be obtained by dehydration imidation of the diamic acid obtained by reacting one or more of those substituted with, for example, in a solvent. The imidization is carried out by a chemical ring-closing method using a tertiary amine and a dehydrating agent such as acetic anhydride or a thermal ring-closing method by heating, and a chemical ring-closing method capable of reacting at a relatively low temperature is preferable.

Also, dicarboxylic acid monomer (IV) constituting the polyester of unit II

[Chemical 11] (Wherein Ar ₄ is as defined above), terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid,
1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 4,4′-biphenylenedicarboxylic acid,
Preference is given to 3,4'-biphenylenedicarboxylic acid, 3,3'-biphenylenedicarboxylic acid, those obtained by substituting hydrogen on these aromatic rings with halogens, alkyl groups or the like, or their alkyl ester derivatives.

These dicarboxylic acid monomers (III),
(IV) and a diol, for example ethylene glycol,
Propylene glycol, 1,4-butanediol, 1,
Polymerizing 5-pentanediol, 1,6-hexanediol, and one or more alkylene glycols such as cyclohexanedimethanol by a known method, for example, a solution polycondensation method, a melt polycondensation method, or a solid phase polymerization method. Thus, a copolyester having units I and II of the present invention can be obtained. The total diol and the total dicarboxylic acid monomer (III + IV) are preferably equimolar, but in practice, the number of moles of the diol may be 90 to 110 mol% with respect to the total number of dicarboxylic acid monomers. It is preferably 95 to 105 mol%. Further, the dicarboxylic acid monomer III is preferably contained in an amount of 1 to 50 mol% based on the total dicarboxylic acid monomers, from the viewpoint of satisfying the formula (1).

As a particularly preferable method, a predetermined ratio of dicarboxylic acid and / or alkyl ester of dicarboxylic acid and alkylene glycol for constituting the above units I and II are mixed with a suitable catalyst, preferably in an inert atmosphere, For example, in the presence of lithium acetate, calcium acetate, magnesium acetate, manganese acetate, cobalt acetate, tetraalkyl titanate, etc., at 150 to 270 ° C.,
An esterification reaction or a transesterification reaction is carried out while removing water or alcohol produced to obtain an oligomer, and then a suitable polymerization catalyst such as an antimony compound, a germanium compound, a titanium compound or a silicon compound, more specifically, a tripolymer is used. A method of polymerizing at 200 to 320 ° C. under reduced pressure in the presence of antimony oxide, germanium dioxide, tetraalkyl titanate and the like can be mentioned. Further, dicarboxylic acid and / or alkyl ester of dicarboxylic acid for constituting the units I and II are separately esterified or transesterified to synthesize an oligomer, which is mixed at a predetermined ratio before the polymerization. You may take the method of doing.

The copolyester thus obtained preferably has an intrinsic viscosity (O-chlorophenol, measured at 25 ° C.) of 0.4 dl / g or more. 0.
If it is less than 4 dl / g, the mechanical strength may be insufficient and it may be difficult to form a film or the like. Solid phase polymerization or the like may be performed to adjust the intrinsic viscosity to this range. A more preferable intrinsic viscosity is 0.5 to 5.0 dl / g.

Further, the copolymerized polyester of the present invention may be blended with another type of polymer within a range that does not impair the effects of the present invention, and an antioxidant, a heat stabilizer, a lubricant, an ultraviolet absorber, an antistatic agent may be blended. Additives such as agents may be added.

The copolymerized polyester of the present invention can be processed into a film, a fiber, a molded product, etc., and in this case, a conventionally known manufacturing method can be applied. For example, in the case of producing a film, after drying the above-mentioned copolyester in the form of pellets, if necessary, it is supplied to a known melt extruder, and a sheet from a slit-shaped die at a melting point of the polymer or higher and a decomposition point or lower. The film is extruded and cooled on a casting roll to prepare an unstretched film. Next, this unstretched film is biaxially stretched and biaxially oriented. As a stretching method, a sequential biaxial stretching method or a simultaneous biaxial stretching method can be used. The stretching area ratio (the ratio of the stretching ratio in the longitudinal direction and the stretching ratio in the transverse direction) is preferably 5.0 to 30.0 times, and the stretching temperature varies depending on the type of polymer and cannot be generally stated, but it is 50 to 200. C is preferred. Further, this stretched film may be heat treated, and the heat treatment temperature is 15
The heat treatment time is preferably 0 to 250 ° C. and the heat treatment time is preferably 0.5 to 120 seconds. Further, when a film is obtained from the copolyester of the present invention, it can be used as a single film, but it can also be used as a composite film laminated with another thermoplastic polymer. The other thermoplastic polymer to be laminated is not particularly limited, but a crystalline polymer is preferable, and examples thereof include polyester, polyamide, polyphenylene sulfide, and polyolefin. In particular, polyesters of the same type as in the present invention are more preferable because of good adhesiveness at the interface. The laminated structure may be any number of layers, but normally, two layers or three layers are preferably used. In the case of three layers, the film of the present invention can be used as an inner layer or an outer layer.

[0016]

EXAMPLES Next, the embodiments of the present invention will be explained based on examples, but the present invention is not limited to these. In addition, the measuring method of the characteristic in an Example is as follows. (1) Strength and Young's modulus Measured with a TRS type tensile tester under the conditions of width 10 mm, length 50 mm, and pulling speed 300 mm / min.

(2) Intrinsic viscosity O-chlorophenol was measured as a solvent at 25 ° C.

(3) Thermal Shrinkage Rate The sample was placed in an oven at 150 ° C. for 10 minutes without load, returned to room temperature, measured for size, and calculated by the following formula. Thermal shrinkage = [(test length before measurement-test length after measurement) / test length before measurement] x 100 (%)

Reference Example 1 Production of N, N'-bis (P-methoxycarbonylphenyl) benzenetetracarboxylic acid diimide (BMB) Ethyl P-aminobenzoate (P-ABA) per 1 mol of pyromellitic acid (PyA). ) 2.1 mol and 1 liter of dehydrated acetone were charged into a reaction tank equipped with a nitrogen inlet tube, a thermometer, and a stirrer, and while stirring, the temperature of the solution was 15-
While maintaining at 25 ° C, PyA was gradually added as a powder, and after the addition was completed, stirring was continued for 1 hour. In order to imidize the obtained amic acid, 4 mol of acetic anhydride and 0.
3 mol was added and refluxed for 1 hour. The product thus obtained was washed twice with acetone and dried under reduced pressure. When the infrared absorption spectra of the amic acid and the product sampled during the measurement were measured, 3,000 to 3, observed in the amic acid, was detected.
It was confirmed that the broad absorption at 500 cm ^-1 disappeared in the product and the absorption at 722 cm ^-1 based on the imide group was observed, and the target BMB was obtained.

[0020]

[Table 1]

Reference Examples 2 to 5 In Reference Example 1, PyA and P-ABA were replaced with the raw materials shown in Table 1 and the same conditions as in Reference Example 1 were used to obtain a product.

Example 1 First, 95 mol% of dimethyl terephthalate (DMT) as a compound represented by the formula (IV) as a raw material of the unit (II), and the formula (III) as a raw material of the unit (I) produced in Reference Example 1 5% by mol of BMB, which is a compound represented by the formula (1), and a double amount (that is, 200
0.06% by weight of magnesium acetate (based on the obtained polymer) was added as a catalyst to (mol%) ethylene glycol (EG), and the mixture was heated (up to 250 ° C.) and stirred under a nitrogen stream to carry out a transesterification reaction. After the reaction, 0.03% by weight of antimony trioxide (based on the obtained polymer),
Trimethyl phosphate 0.03% by weight (based on the polymer obtained) was added, the temperature was raised to 290 ° C. in 2 hours, and the pressure was reduced to 0.5 mmHg in 1.5 hours. After polymerizing at 0.5 mmHg for 1 hour, the polymer was taken out. The intrinsic viscosity of the obtained polymer was 0.74 dl / g, 725 cm ⁻¹ based on the imide group was observed in the infrared absorption spectrum, and further, from the elemental analysis, C = 62.88% (theoretical value 62.76% ), H =
The results were 4.10% (theoretical value 4.05%) and N = 0.71% (theoretical value 0.68%), indicating that the desired polymer was obtained.

Next, at 290 ° C., an extruder was used to extrude from a T die onto a casting drum having a surface temperature of 30 ° C.,
An unstretched film was produced. This unstretched film is
It was stretched 3.5 times in the machine direction at 0 ° C. This stretching was carried out in three stages with the difference in peripheral speed between each pair of rolls. This uniaxially stretched film was stretched 4.0 times in the transverse direction at 95 ° C. using a stenter and then wound into a roll. The Young's modulus in the machine direction of the obtained film was 450 kg / mm ² , 150 ° C., and 3
The heat shrinkage rate of 0 minutes is 0.9%, which is excellent in mechanical properties and heat resistance.
It was also found that the film has flame retardant properties such that it extinguishes immediately when the film is ignited and then released from the fire source.

Examples 2 to 5 Example 1 except that the type of copolymerized polyester raw material, the amount of copolymerization and the like were changed as shown in Table 2 in Example 1.
Copolyesters were obtained in the same manner as in Example 1, and the properties of the films obtained from these polymers in the same manner as in Example 1 were excellent.

[0025]

[Table 2]

Comparative Examples 1 to 2 Properties of a film obtained from a polymer obtained in the same manner as in Example 1 except that the type of copolymerized polyester raw material, the amount of copolymerization, etc. in Example 1 were changed as shown in Table 2. Was insufficient, such as poor mechanical properties or heat resistance.

[0027]

The copolyester of the present invention is excellent in moldability and thus can be easily processed into a fiber, a film, a molded product, etc., and is excellent in mechanical properties, heat resistance and flame retardancy. To be Therefore, even if it is thin or thin, it is excellent in handleability during handling. In particular, it can be used for base films such as magnetic recording media and printer ribbons, and electrical insulating materials such as capacitors and FPCs (flexible printed wiring boards). Suitable for packaging materials.

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[Procedure amendment]

[Submission date] February 18, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Chemical 1] {Wherein Ar ₁ , Ar ₃ and Ar _{4 each} independently represent a divalent aromatic residue, and Ar ₂ represents a tetravalent aromatic residue,
R ₁ and R ₂ independently represent a linear, branched, or cyclic divalent aliphatic having 1 to 12 carbon atoms. X and Y represent the mole fractions of units I and II, respectively, and satisfy the following formula (1). 0.01 ≦ X / (X + Y) ≦ 0.50 (1)}

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Detailed explanation of the invention

[Correction method] Change

[Correction content]

Detailed Description of the Invention

[0001]

The present invention relates to mechanical properties such as rigidity,
The present invention relates to a polyester having excellent heat resistance, flame retardancy, and moldability, and provides a polyester that can be processed into films, fibers, molded products and the like.

[0002]

2. Description of the Related Art In recent years, miniaturization in the field of electric and electronic equipment,
With the progress of weight reduction, not only downsizing of materials to be used but also simplification, shortening of process and speeding up have been demanded for heat resistance and high strength. Aromatic polyesters typified by polyethylene terephthalate have been conventionally used in these fields, but there is a limit in mechanical properties and heat resistance, and it has become difficult to satisfy the above required properties. Therefore, for high heat resistance and high rigidity, copolymerization of liquid crystal polyester and liquid crystal components (for example, “High-performance aromatic polymer materials” edited by Polymer Society of Japan (Maruzen)) is being studied.

[0003]

However, although the liquid crystal polymer has relatively high heat resistance and high rigidity among the molten polymers, it has a problem that it is strongly oriented in the flow direction and the strength in the direction perpendicular thereto is lowered. However, the moldability into a film that needs to be biaxially stretched in the machine direction and the width direction was poor. On the other hand, even if an attempt is made to copolymerize a rigid component that contributes to the expression of liquid crystallinity with an aromatic polyester in a small amount that does not exhibit liquid crystallinity, the degree of polymerization does not increase and a polymer having sufficient strength cannot be obtained. There was a problem. An object of the present invention is to solve such problems and provide a copolyester having excellent mechanical properties such as rigidity, heat resistance, and moldability.

[0004]

The present invention provides units I and II represented by the following formula.

[Chemical 2] {Wherein Ar ₁ , Ar ₃ and Ar _{4 each} independently represent a divalent aromatic residue, and Ar ₂ represents a tetravalent aromatic residue,
R ₁ and R ₂ independently represent a linear, branched, or cyclic divalent aliphatic having 1 to 12 carbon atoms. X and Y represent the mole fractions of units I and II, respectively, and satisfy the following formula (1). 0.01 ≦ X / (X + Y) ≦ 0.50 (1)}.

Ar ₁ , Ar ₃ and Ar ₄ of the above units I and II constituting the copolyester of the present invention each independently represent a divalent aromatic residue, preferably having 6 to 24 carbon atoms. It is an aromatic ring. Each of these aromatic rings is 1
Not only one, but also two or more may be formed, and hydrogen on the aromatic ring may be substituted with halogen, an alkyl group having 1 to 3 carbon atoms, a phenyl group, a cyano group, a nitro group, or the like. When there is one aromatic ring, para and meta structures are preferable, and when there are two or more aromatic rings, divalent aromatic residues corresponding to these are preferable, and for example, the following structures are more preferable.

[Chemical 3] (In the formula, those in which hydrogen on the aromatic ring is substituted with halogen, an alkyl group having 1 to 3 carbon atoms, a phenyl group, a cyano group, a nitro group, etc.)

More preferably, it is of para-type,

[Chemical 4] And so on.

Ar ₂ represents a tetravalent aromatic residue, and preferably has the following structure.

[Chemical 5] On the other hand, R ₁ and R ₂ are independently a straight chain having 1 to 12 carbon atoms,
It is a branched or cyclic divalent aliphatic residue, and preferably a linear or branched alkylene group having 2 to 8 carbon atoms, a cycloalkylene group having 4 to 10 carbon atoms, or 6 carbon atoms.
To 12 cycloalkylenedialkylene groups, more preferably

[Chemical 6] Etc., in particular,

[Chemical 7] Is preferred.

Further, the mole fraction of the unit I constituting the copolyester of the present invention is X, and the unit II is the unit II.
X is 0.01 ≦ X / (X +
It is necessary that Y) ≦ 0.50. X /
When (X + Y) <0.01, the mechanical properties and heat resistance, which are the effects of the present invention, are not sufficiently improved, and X / (X + Y)>
When it is 0.50, the melting point may exceed 350 ° C. and molding may not be possible, or liquid crystal properties may start to be expressed and strongly oriented in one direction, resulting in poor moldability for a film or the like. Preferably 0.0
1 ≦ X / (X + Y) ≦ 0.40, more preferably 0.0
1 ≦ X / (X + Y) ≦ 0.35.

Next, a method for producing the copolyester of the present invention will be described. First, a dicarboxylic acid (II
I)

[Chemical 8] (Wherein Ar ₁ , Ar ₂ and Ar ₃ are the same as defined above) or an ester derivative thereof is

[Chemical 9] (Wherein Ar ₁ and Ar ₃ are the same as defined above), for example, methyl of aminocarboxylic acid such as P-aminobenzoic acid, m-aminobenzoic acid and 2-amino-6-naphthoic acid. One or more of ester or ethyl ester derivatives,

[Chemical 10] (Wherein Ar ₂ is the same as the above definition), a tetracarboxylic dianhydride, for example, pyromellitic dianhydride,
2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenylenetetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic acid dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic acid dianhydride, or hydrogen on these aromatic rings is a halogen or alkyl group. It can be obtained by dehydration imidation of the diamic acid obtained by reacting one or more of those substituted with, for example, in a solvent. The imidization is carried out by a chemical ring-closing method using a tertiary amine and a dehydrating agent such as acetic anhydride or a thermal ring-closing method by heating, and a chemical ring-closing method capable of reacting at a relatively low temperature is preferable.

Also, dicarboxylic acid monomer (IV) constituting the polyester of unit II

[Chemical 11] (Wherein Ar ₄ is as defined above), terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid,
1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 4,4′-biphenylenedicarboxylic acid,
Preference is given to 3,4'-biphenylenedicarboxylic acid, 3,3'-biphenylenedicarboxylic acid, those obtained by substituting hydrogen on these aromatic rings with halogens, alkyl groups or the like, or their alkyl ester derivatives.

These dicarboxylic acid monomers (III),
(IV) and a diol, for example ethylene glycol,
Propylene glycol, 1,4-butanediol, 1,
Polymerizing 5-pentanediol, 1,6-hexanediol, and one or more alkylene glycols such as cyclohexanedimethanol by a known method, for example, a solution polycondensation method, a melt polycondensation method, or a solid phase polymerization method. Thus, a copolyester having units I and II of the present invention can be obtained. The total diol and the total dicarboxylic acid monomer (III + IV) are preferably equimolar, but in practice, the number of moles of the diol may be 90 to 110 mol% with respect to the total number of dicarboxylic acid monomers. It is preferably 95 to 105 mol%. Further, the dicarboxylic acid monomer III is preferably contained in an amount of 1 to 50 mol% based on the total dicarboxylic acid monomers, from the viewpoint of satisfying the formula (1).

As a particularly preferable method, a predetermined ratio of dicarboxylic acid and / or alkyl ester of dicarboxylic acid and alkylene glycol for constituting the above units I and II are mixed with a suitable catalyst, preferably in an inert atmosphere, For example, in the presence of lithium acetate, calcium acetate, magnesium acetate, manganese acetate, cobalt acetate, tetraalkyl titanate, etc., at 150 to 270 ° C.,
An esterification reaction or a transesterification reaction is carried out while removing water or alcohol produced to obtain an oligomer, and then a suitable polymerization catalyst such as an antimony compound, a germanium compound, a titanium compound or a silicon compound, more specifically, a tripolymer is used. A method of polymerizing at 200 to 320 ° C. under reduced pressure in the presence of antimony oxide, germanium dioxide, tetraalkyl titanate and the like can be mentioned. Further, dicarboxylic acid and / or alkyl ester of dicarboxylic acid for constituting the units I and II are separately esterified or transesterified to synthesize an oligomer, which is mixed at a predetermined ratio before the polymerization. You may take the method of doing.

The copolyester thus obtained preferably has an intrinsic viscosity (O-chlorophenol, measured at 25 ° C.) of 0.4 dl / g or more. 0.
If it is less than 4 dl / g, the mechanical strength may be insufficient and it may be difficult to form a film or the like. Solid phase polymerization or the like may be performed to adjust the intrinsic viscosity to this range. A more preferable intrinsic viscosity is 0.5 to 5.0 dl / g.

Further, the copolymerized polyester of the present invention may be blended with another type of polymer within a range that does not impair the effects of the present invention, and an antioxidant, a heat stabilizer, a lubricant, an ultraviolet absorber, an antistatic agent may be blended. Additives such as agents may be added.

The copolymerized polyester of the present invention can be processed into a film, a fiber, a molded product, etc., and in this case, a conventionally known manufacturing method can be applied. For example, in the case of producing a film, after drying the above-mentioned copolyester in the form of pellets, if necessary, it is supplied to a known melt extruder, and a sheet from a slit-shaped die at a melting point of the polymer or higher and a decomposition point or lower. The film is extruded and cooled on a casting roll to prepare an unstretched film. Next, this unstretched film is biaxially stretched and biaxially oriented. As a stretching method, a sequential biaxial stretching method or a simultaneous biaxial stretching method can be used. The stretching area ratio (the ratio of the stretching ratio in the machine direction and the stretching ratio in the transverse direction) is preferably 5.0 to 30.0 times, and the stretching temperature varies depending on the type of polymer and cannot be generally stated, but it is 50 to 200. C is preferred. Further, this stretched film may be heat treated, and the heat treatment temperature is 15
The heat treatment time is preferably 0 to 250 ° C. and the heat treatment time is preferably 0.5 to 120 seconds. Further, when a film is obtained from the copolyester of the present invention, it can be used as a single film, but it can also be used as a composite film laminated with another thermoplastic polymer. The other thermoplastic polymer to be laminated is not particularly limited, but a crystalline polymer is preferable, and examples thereof include polyester, polyamide, polyphenylene sulfide, and polyolefin. In particular, polyesters of the same type as in the present invention are more preferable because of good adhesiveness at the interface. The laminated structure may be any number of layers, but normally, two layers or three layers are preferably used. In the case of three layers, the film of the present invention can be used as an inner layer or an outer layer.

[0016]

EXAMPLES Next, the embodiments of the present invention will be explained based on examples, but the present invention is not limited to these. In addition, the measuring method of the characteristic in an Example is as follows. (1) Strength and Young's modulus Measured with a TRS type tensile tester under the conditions of width 10 mm, length 50 mm, and pulling speed 300 mm / min.

(2) Intrinsic viscosity O-chlorophenol was measured as a solvent at 25 ° C.

(3) Thermal Shrinkage Rate The sample was placed in an oven at 150 ° C. for 10 minutes without load, returned to room temperature, measured for size, and calculated by the following formula. Thermal shrinkage = [(test length before measurement-test length after measurement) / test length before measurement] x 100 (%)

Reference Example 1 Production of N, N'-bis (P-methoxycarbonylphenyl) benzenetetracarboxylic acid diimide (BMB) Ethyl P-aminobenzoate (P-ABA) per 1 mol of pyromellitic acid (PyA). ) 2.1 mol and 1 liter of dehydrated acetone were charged into a reaction tank equipped with a nitrogen inlet tube, a thermometer, and a stirrer, and while stirring, the temperature of the solution was 15-
While maintaining at 25 ° C, PyA was gradually added as a powder, and after the addition was completed, stirring was continued for 1 hour. In order to imidize the obtained amic acid, 4 mol of acetic anhydride and 0.
3 mol was added and refluxed for 1 hour. The product thus obtained was washed twice with acetone and dried under reduced pressure. When the infrared absorption spectra of the amic acid and the product sampled during the measurement were measured, 3,000 to 3, observed in the amic acid, was detected.
It was confirmed that the broad absorption at 500 cm ^-1 disappeared in the product and the absorption at 722 cm ^-1 based on the imide group was observed, and the target BMB was obtained.

[0020]

[Table 1]

Reference Examples 2 to 5 In Reference Example 1, PyA and P-ABA were replaced with the raw materials shown in Table 1 and the same conditions as in Reference Example 1 were used to obtain a product.

Example 1 First, 95 mol% of dimethyl terephthalate (DMT) as a compound represented by the formula (IV) as a raw material of the unit (II), and the formula (III) as a raw material of the unit (I) produced in Reference Example 1 5% by mol of BMB, which is a compound represented by the formula (1), and a double amount (that is, 200
0.06% by weight of magnesium acetate (based on the obtained polymer) was added as a catalyst to (mol%) ethylene glycol (EG), and the mixture was heated (up to 250 ° C.) and stirred under a nitrogen stream to carry out a transesterification reaction. After the reaction, 0.03% by weight of antimony trioxide (based on the obtained polymer),
Trimethyl phosphate 0.03% by weight (based on the polymer obtained) was added, the temperature was raised to 290 ° C. in 2 hours, and the pressure was reduced to 0.5 mmHg in 1.5 hours. After polymerizing at 0.5 mmHg for 1 hour, the polymer was taken out. The intrinsic viscosity of the obtained polymer was 0.74 dl / g, 725 cm ⁻¹ based on the imide group was observed in the infrared absorption spectrum, and further elemental analysis showed that C = 62.88% (theoretical value 62.76%). ), H =
The results were 4.10% (theoretical value 4.05%) and N = 0.71% (theoretical value 0.68%), indicating that the desired polymer was obtained.

Next, at 290 ° C., an extruder was used to extrude from a T die onto a casting drum having a surface temperature of 30 ° C.,
An unstretched film was produced. This unstretched film is
It was stretched 3.5 times in the machine direction at 0 ° C. This stretching was carried out in three stages with the difference in peripheral speed between each pair of rolls. This uniaxially stretched film was stretched 4.0 times in the transverse direction at 95 ° C. using a stenter and then wound into a roll. The Young's modulus in the machine direction of the obtained film was 450 kg / mm ² , 150 ° C., and 3
The heat shrinkage rate of 0 minutes is 0.9%, which is excellent in mechanical properties and heat resistance.
It was also found that the film has flame retardant properties such that it extinguishes immediately when the film is ignited and then released from the fire source.

Examples 2 to 5 Example 1 except that the type of copolymerized polyester raw material, the amount of copolymerization and the like were changed as shown in Table 2 in Example 1.
Copolyesters were obtained in the same manner as in Example 1, and the properties of the films obtained from these polymers in the same manner as in Example 1 were excellent.

[0025]

[Table 2]

Comparative Examples 1 to 2 Properties of a film obtained from a polymer obtained in the same manner as in Example 1 except that the type of copolymerized polyester raw material, the amount of copolymerization, etc. in Example 1 were changed as shown in Table 2. Was insufficient, such as poor mechanical properties or heat resistance.

[0027]

The copolyester of the present invention is excellent in moldability and thus can be easily processed into a fiber, a film, a molded product, etc., and is excellent in mechanical properties, heat resistance and flame retardancy. To be Therefore, even if it is thin or thin, it is excellent in handleability during handling. In particular, it can be used for base films such as magnetic recording media and printer ribbons, and electrical insulating materials such as capacitors and FPCs (flexible printed wiring boards). Suitable for packaging materials.

Claims (1)

[Claims] 1. Units I and II represented by the following formula: {Wherein Ar ₁ , Ar ₃ and Ar _{4 each} independently represent a divalent aromatic residue, and Ar ₂ represents a tetravalent aromatic residue,
R ₁ and R ₂ independently represent a linear, branched, or cyclic divalent aliphatic having 1 to 12 carbon atoms. X and Y represent the mole fractions of units I and II, respectively, and satisfy the following formula (1). 0.01 ≦ X / (X + Y) ≦ 0.50 (1)}