JP2003292592A - Copolyester and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester which has a high degree of polymerization, high transparency and good solvent adhesiveness and is especially suitable for films. <P>SOLUTION: This copolyester is characterized by containing terephthalic acid as a main dicarboxylic acid component, containing 50 to 85 mol.% of ethylene glycol, 10 to 45 mol.% of 1,4-cyclohexanedimethanol and 1.5 to 7 mol.% of diethylene glycol in the total glycol component, and having an intrinsic viscosity of 0.7 to 0.85 dl/g. Preferably, at least one compound selected from antimony compounds, germanium compounds and titanium compounds is used as a polymerization catalyst. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a copolyester and a method for producing the same, and more particularly to a copolyester in which ethylene terephthalate is a main ester unit and 1,4-cyclohexanedimethanol is copolymerized and a method for producing the same.

[0002]

2. Description of the Related Art Polyester, especially polyethylene terephthalate (PET) produced from ethylene glycol and terephthalic acid as raw materials, has excellent chemical and physical properties, and is therefore used in containers, films, sheets, fibers and the like. Widely used in. Recently, attention has been paid to the fact that a polyester obtained by copolymerizing 1,4-cyclohexanedimethanol (hereinafter also abbreviated as CHDM) with such polyethylene terephthalate (PET) is excellent in transparency, impact resistance, moldability, heat resistance and the like. Therefore, it has come to be widely used for various purposes, particularly for films (sheets) and engineering plastics.

However, when a film produced by using polyester obtained by copolymerizing PET with 1,4-cyclohexanedimethanol as a part or all of the film raw material is used, for example, in a heat shrink film application. It has been found that the film may have a problem such as peeling from the adherend and the solvent adhesiveness is not sufficient.

On the other hand, the uniformity of the thickness of the polyester film greatly contributes to various properties such as transparency, mechanical strength and heat resistance of the polyester film, and it is an important subject to improve the uniformity of the thickness of the polyester film. Is one. Further, in terms of the productivity of the polyester film, since the productivity directly depends on the casting speed, how to increase the casting speed is an important issue.

Usually, a polyester film is obtained by melt-extruding polyester and then biaxially stretching (that is, a sheet material melt-extruded by an extruder is brought into close contact with the surface of a rotating cooling drum and then taken out, It is obtained by guiding the sheet-like material to a stretching roll arranged in the subsequent stage of the cooling drum, longitudinally stretching it, and then laterally stretching it with a tenter, followed by heat setting (heat setting). Therefore, in order to increase the film thickness uniformity and increase the casting speed, the sheet material melt-extruded from the extrusion die must be adhered to the cooling rotary drum with a sufficiently high adhesive force. In addition, the electrostatic contact casting method is used. The electrostatic contact casting method is a method in which a wire-shaped electrode is provided between the extrusion die and the cooling rotary drum to apply a high voltage to cause static electricity to deposit on the surface of the unsolidified sheet-like material, Is electrostatically attached to the surface of the cooling rotary drum. In such an electrostatic contact casting method, in order to improve the electrostatic adherence of the sheet material to the cooling rotary drum, it is necessary to increase the charge amount on the surface of the sheet material. The melt specific resistance of polyester is reduced by adjusting the type and amount.

However, in the polyester obtained by copolymerizing PET with 1,4-cyclohexanedimethanol,
The conditions for use (type, amount, etc.) of the polymerization catalyst that can sufficiently obtain the activation effect (catalytic activity) of the polymerization reaction and that can sufficiently reduce the melt specific resistance do not apply to PET as they are. In the conditions, with a high degree of polymerization,
In addition, it is difficult to obtain a product having good electrostatic adhesion, and the thermal stability of the polyester produced is impaired, and in particular, thermal decomposition occurs during molding such as film formation.

[0007]

In view of the above circumstances, the present invention provides a polyester having a high degree of polymerization, high transparency, and good solvent adhesiveness, which is particularly suitable for films and a method for producing the same. The purpose is to do. Further, the present invention provides a polyester having the above-mentioned preferable properties (high polymerization degree, high transparency, and good solvent adhesiveness) and capable of forming a film rapidly and stably (without thermal decomposition), and a method for producing the same. The purpose is to do.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a specific amount of PET of 1,
By copolymerizing a specific amount of diethylene glycol with 4-cyclohexanedimethanol, the transparency and solvent adhesiveness of the polyester are greatly improved,
Further, in the production of such a copolyester, while using a specific amount of at least one selected from an antimony compound, a germanium compound and a titanium compound as a polymerization catalyst, an alkali metal compound, an alkaline earth metal compound and a phosphorus compound as a polymerization catalyst, Set the ratio of the amount of alkali metal compound and alkaline earth metal compound used to a specific range, and set the ratio of the total amount of alkali metal compound and alkaline earth metal compound used and the amount of phosphorus compound used to a specific range. It was found that a copolymerized polyester having a high degree of polymerization and a sufficiently low melt specific resistance can be obtained by using it, and has completed the present invention.

That is, the present invention is as follows. (1) The main dicarboxylic acid component is terephthalic acid, and ethylene glycol is 50 to 50% of all glycol components.
85 mol% of 1,4-cyclohexanedimethanol to 1
A copolyester comprising 0 to 45 mol% and diethylene glycol of 1.5 to 7 mol% and an intrinsic viscosity of 0.7 to 0.85 dl / g. (2) A polyester obtained by using at least one selected from an antimony compound, a germanium compound and a titanium compound as a polymerization catalyst, wherein the content of the antimony compound in the polyester is 100 to 500 ppm as Sb atomic weight, and the germanium compound is Content in polyester of 15 to 250 pp as Ge atomic weight
The copolymerized polyester according to (1) above, wherein the content of m and the titanium compound in the polyester is 5 to 50 ppm in terms of Ti atomic weight. (3) A polyester obtained by using, as a polymerization catalyst, at least one selected from an antimony compound, a germanium compound and a titanium compound, an alkali metal compound, an alkaline earth metal compound, and a phosphorus compound, The content of the compound in the polyester is S
b atomic weight is 100 to 500 ppm, and the content of germanium compound in polyester is 15 as Ge atomic weight.
˜250 ppm, content of titanium compound in polyester is 5 to 50 ppm as Ti atomic weight, content of alkali metal compound in polyester is 5 to 30 ppm as alkali metal atomic weight (M1) and content in polyester of alkaline earth metal compound The amount is 50 to 250 ppm as the alkaline earth metal atomic weight (M2), and the alkaline metal atomic weight (M1) and the alkaline earth metal atomic weight (M2) have the relationship of the following formula (I), and the alkali The relationship between the metal atomic weight (M1), the alkaline earth metal atomic weight (M2), and the P atomic weight (p) as the content of the phosphorus compound in the polyester satisfies the following formula (II): 1) The copolyester as described. Formula (I): 2 ≦ M2 / M1 (weight ratio) ≦ 40 Formula (II): 0.5 ≦ (M1 + M2) / p (weight ratio) ≦ 10 (4) Melt specific resistance at 275 ° C. is 0.1 × 10 ^{8 to} 0.
The copolyester according to (1) above, which has a density of 75 × 10 ⁸ Ω · cm. (5) A method for producing the copolyester according to the above (1), which comprises polymerizing a raw material monomer containing 0.5 to 6.5 mol% of diethylene glycol with respect to all glycols by a continuous polymerization method. Method for producing polyester. (6) A method for producing the copolyester according to the above (1), wherein a raw material monomer containing 0.5 to 6.5 mol% of diethylene glycol based on all glycols is polymerized by a batch polymerization method to produce A method for producing polyester, wherein the polymer is withdrawn from the polymerization reaction can while maintaining the pressure inside the polymerization reaction can at 0.1 to 300 hPa. (7) At least one selected from an antimony compound, a germanium compound and a titanium compound is used as a polymerization catalyst, and the content of the antimony compound in the polyester is 100 to 500 p as Sb atomic weight.
pm, the content of the germanium compound in the polyester is 15 to 250 ppm as the Ge atomic weight, and the content of the titanium compound in the polyester is 5 to 50 ppm as the Ti atomic weight, (5) or ( 6) The method for producing a polyester as described above. (8) The polyester according to (7) above, which further comprises an alkali metal compound, an alkaline earth metal compound and a phosphorus compound as a polymerization catalyst, and which satisfies the following formulas (I) and (II): Manufacturing method. Formula (I): 2 ≦ M2 / M1 (weight ratio) ≦ 40 Formula (II): 0.5 ≦ (M1 + M2) / p ≦ 10 (weight ratio) In the formula, M1 is the polyester produced by the alkali metal compound. Alkali metal atomic amount as content, M2 is alkaline earth metal atomic amount as content in polyester produced by alkaline earth metal compound, and p is P atomic amount as content in polyester produced by phosphorus compound.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The copolyester of the present invention (hereinafter, also simply referred to as polyester) is composed mainly of terephthalic acid as a dicarboxylic acid component, and contains 50 to 85 mol% of ethylene glycol in all glycol components and 10 to 4,4-cyclohexanedimethanol. 45 mol%, diethylene glycol 1.5
-7 mol% and intrinsic viscosity 0.7-0.85 dl / g
Is characterized in that.

That is, in the copolyester of the present invention, the main ester unit is ethylene terephthalate, and a specific amount of 1,4-cyclohexanedimethanol is copolymerized with a specific amount of diethylene glycol to obtain good transparency and solvent adhesion. The greatest feature is that the amount of diethylene glycol in the glycol component is larger than that of the conventional copolyester of this type.

It is known that diethylene glycol is produced as a glycol component during the polymerization of PET. However, when polymerizing a copolyester in which 1,4-cyclohexanedimethanol is copolymerized with PET in an amount of 10 mol% or more based on all glycol components, reaction conditions (catalyst,
The amount of diethylene glycol in the glycol component does not exceed 1.5 mol% only by adjusting the temperature, pressure, etc.). Therefore, in the present invention, the charged raw material (monomer)
A specific amount of diethylene glycol, that is, 0.5 to 6.5 of diethylene glycol based on the total glycol.
The amount of diethylene glycol based on all glycol components is 1.5 to 7.0 mol% (preferably 2. 5 mol%) by means of blending mol% (preferably 1.0 to 5.5 mol%).
5 to 5.0 mol%) are copolymerized.

When the amount of diethylene glycol is less than 1.5 mol% based on the total glycol component, such polyesters do not have good solvent adhesion, and when the amount of diethylene glycol exceeds 7.0 mol%, it is Such a polyester undergoes severe thermal decomposition at the time of molding, resulting in coloration of the molded product, decrease in molecular weight, formation of by-products and deterioration in physical properties.

The polyester of the present invention is 0.70 to 0.8
It has an intrinsic viscosity of 5 dl / g, and in order to achieve such an intrinsic viscosity, an antimony compound as a polymerization catalyst,
At least one selected from germanium compounds and titanium compounds is used. The content of antimony compound in the polyester produced is 100 as Sb atomic weight.
˜500 ppm, preferably 200 to 400 ppm, and the germanium compound has a Ge content of 15 to 250 ppm as Ge atomic weight.
The titanium compound is preferably used in an amount of 25 to 100 ppm, and the titanium compound is used in an amount of 5 to 50 ppm, preferably 5 to 30 ppm in terms of Ti atom content in the produced polyester.

When the amount of each of the antimony compound, the germanium compound and the titanium compound used is less than the above-specified range, the polyester does not have a sufficiently high degree of polymerization (that is, an intrinsic viscosity of 0.70 dl / g or more). (Not achieved), and the productivity is also significantly reduced. On the other hand, if the amount used is more than the above-specified range, thermal decomposition of the polyester becomes severe during molding of the polyester (particularly during film formation), stable molding cannot be performed, and the quality of the molded product deteriorates.

As the antimony compound, germanium compound and titanium compound, any one kind or two or more kinds thereof can be used, but it is preferable to use at least the antimony compound, and only the antimony compound or the antimony compound. Is particularly preferably used in combination with a germanium compound or a titanium compound.

In the polyester of the present invention, the preferred intrinsic viscosity is 0.65 to 0.80 dl / g.

Further, the polyester of the present invention is particularly intended for a film, and in order to exhibit a good electrostatic adhesion property in the electrostatic adhesion casting method, the melt specific resistance at 275 ° C.
(Hereinafter sometimes abbreviated as ρi) is 0.1 × 10 ^{8 to} 0.
75 × 10 ⁸ Ω · cm (preferably 0.15 × 10 ⁸ 〜
0.30 × 10 ⁸ Ω · cm) is desirable. That is, when the melting specific resistance is less than 0.1 × 10 ⁸ Ω · cm, such polyester is likely to be charged or has poor thermal stability. The melting specific resistance is 0.75 × 1
If greater than 0 ⁸ Omega · cm, such polyester is not good electrostatic adhesion to a cooling rotating drum during film is obtained, it is difficult to produce a uniform thickness film at high speed.

The resulting polyester has the above-mentioned sufficiently high intrinsic viscosity, does not cause thermal decomposition during film formation, and
In order to make it possible to form a film having a uniform thickness at a high speed, as a polymerization catalyst, at least one selected from the above-mentioned antimony compound, germanium compound and titanium compound is used in addition to the specific amount, in addition to this. The specific amounts of the alkali metal compound and the alkaline earth metal compound are used, respectively, and the ratios of these amounts are set to a certain relationship (the relationship of the following formula (I)). Further, the phosphorus compound is added to the alkali metal compound and the alkaline earth metal compound. Certain relationship to the total amount of compound used (relationship of the following formula (II))
It is preferable to use so that Formula (I): 2 ≦ M2 / M1 (weight ratio) ≦ 40 Formula (II): 0.5 ≦ (M1 + M2) / p (weight ratio) ≦ 10 M1 in formula (I) and formula (II) is an alkali Alkali metal atomic weight as content in polyester produced by metal compound, M2 is alkaline earth metal atomic weight as content in polyester produced by alkaline earth metal compound, p in formula (II) is phosphorus compound It is the P atomic weight as the content in the produced polyester.

When M2 / M1 does not satisfy the formula (I), the ρi value does not fall within the above-specified range, and good electrostatic adhesion to the cooling rotary drum cannot be obtained during film formation. It becomes difficult to produce a film having a uniform thickness at a high speed. The M2 / M1 is preferably in the range of 5 or more and 20 or less.

When (M1 + M2) / p does not satisfy the formula (II), the ρi value does not fall within the range specified above, and good electrostatic adhesion to the cooling rotary drum is obtained during film formation. Therefore, it may be difficult to produce a film having a uniform thickness at a high speed, or the thermal stability may decrease. The (M1
+ M2) / p is preferably in the range of 1.5 or more and 4.0 or less.

The alkali metal atomic weight (M1) in the above alkali metal compound is preferably 5 to 30 ppm, particularly preferably 10 to 20 ppm, and the alkaline earth metal atomic weight (M2) in the alkaline earth metal compound is 5
0 to 250 ppm is preferable, and particularly preferably 70 to 1
It is 30 ppm. Alkali metal atomic weight (M1) is 5p
If it is less than pm, the ρi value becomes large, and good electrostatic adhesion to the cooling rotary drum cannot be obtained during film formation, making it difficult to produce a film having a uniform thickness at a high speed.
If it exceeds, the thermal stability will decrease. Also, when the alkaline earth metal atomic weight (M2) is less than 50 ppm, the ρi value becomes large, and good electrostatic adhesion to the cooling rotary drum cannot be obtained during film formation, and a film of uniform thickness can be produced at high speed. Becomes difficult, and when it exceeds 250 ppm, the thermal stability decreases.

The main dicarboxylic acid component of the copolymerized polyester of the present invention is terephthalic acid, and the amount of terephthalic acid component based on the total dicarboxylic acid component is preferably 70.
It is at least mol%, particularly preferably at least 85 mol%, particularly preferably at least 95 mol%, most preferably 100 mol%. Other dicarboxylic acid components that can be used together with terephthalic acid include aromatic dicarboxylic acids such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, and adipic acid. , Aliphatic dicarboxylic acids such as sebacic acid, succinic acid and glutaric acid, and alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid. Further, the copolymerized polyester of the present invention, the acid component other than the dicarboxylic acid component may be further copolymerized,
Examples of such an acid component include oxyacids such as p-oxybenzoic acid and oxycaproic acid. In the present invention, the dicarboxylic acid component and the acid component other than the dicarboxylic acid component include, for example, an ester-forming derivative such as an alkyl ester having 1 to 4 carbon atoms at the raw material stage before polymerization.

On the other hand, the glycol component is, as described above, 50 to 50% of ethylene glycol in the total glycol component.
85 mol% of 1,4-cyclohexanedimethanol to 1
0-45 mol%, diethylene glycol 1.5-7.
It is essential to contain 0 mol%.

If the amount of ethylene glycol is less than 50 mol%, the thermal stability will be poor, the transparency will be poor, the molecular weight will be low, and the polymerizability will be low. Therefore, the amount of ethylene glycol must be at least 50 mol%. Is. Also 1,4
-If the amount of cyclohexanedimethanol is less than 10 mol%, the transparency, impact resistance, moldability, etc. of the polyester are lowered, and if it exceeds 45 mol%, the thermal stability is lowered, the transparency is poor, and the molecular weight is lowered. However, problems such as a decrease in polymerizability will occur. The amount of diethylene glycol is 1.5 mol%
If it is less than 7.0, the solvent adhesiveness of the polyester is lowered to 7.0.
When it exceeds the mol%, the thermal stability is lowered and the color tone is deteriorated. The amount of 1,4-cyclohexanedimethanol in all glycol components is preferably 20 to 40 mol%,
25-35 mol% is particularly preferable, the amount of diethylene glycol is preferably 1.5-4.0 mol%, 2.5-
3.5 mol% is particularly preferred.

In the polyester of the present invention, it is preferable that all the glycol components are composed of ethylene glycol, 1,4-cyclohexanedimethanol and diethylene glycol, but the transparency, solvent adhesiveness, etc. of the polyester which is the object of the present invention. In order to impart or improve desired functions (characteristics) to the polyester within a range that does not inhibit
Other glycol components other than ethylene glycol, 1,4-cyclohexanedimethanol and diethylene glycol may be used in a range of less than 2.0 mol% of all glycol components. As the other glycol component,
Trimethylene glycol, tetramethylene glycol,
Neopentyl glycol, pentamethylene glycol,
Aliphatic glycols such as hexamethylene glycol;
Alicyclic glycols such as 1,3-cyclohexanedimethanol; aromatic glycols such as p-xylylene glycol and m-xylylene glycol. Among these, neopentyl glycol can be preferably used. Further, these glycol components may be used alone or in combination of two or more kinds at any ratio.

The copolyester of the present invention uses the above-mentioned polymerization catalyst, uses a raw material monomer containing a dicarboxylic acid and a glycol, and reacts the dicarboxylic acid and the glycol directly to produce water in the same manner as the conventional polyester. After distilling off to esterify, a direct esterification method of performing melt polycondensation under reduced pressure, or using a raw material monomer containing dialkyl dicarboxylate and glycol, reacting dialkyl dicarboxylate with glycol to distill alcohol Although it can be produced by a transesterification method in which it is removed and transesterified, and then melt polycondensation is performed under reduced pressure, in the present invention, as described above, the amount of diethylene glycol in the raw material monomer is 0.5 to It is necessary to use it within the range of 6.5 mol%. If the amount of diethylene glycol in the raw material monomer is less than 0.5 mol% with respect to the total glycol, it is not possible to produce a polyester in which the amount of diethylene glycol in the total glycol component is 1.5 mol% or more, and the amount of diethylene glycol in the raw material monomer. Is more than 6.5 mol% with respect to the total glycol, the amount of diethylene glycol in the total glycol component of the produced polyester exceeds 7.0 mol%.

The above-mentioned polymerization reaction may be carried out in a batch reaction apparatus (batch polymerization method) or a continuous reaction apparatus (continuous polymerization method), but it may be carried out in a continuous reaction apparatus (continuous polymerization method). By manufacturing it legally, for example, 20t in continuous operation
When the on is produced, the fluctuation range (minimum value to maximum value) of the intrinsic viscosity (degree of polymerization) can be suppressed to 0.05 dl / g or less, preferably 0.025 dl / g or less, and the amount of diethylene glycol component (co The fluctuation range (minimum value to maximum value) of the polymerization amount) can be suppressed to 0.5 mol% or less, preferably 0.3 mol% or less.

In the continuous reaction apparatus (continuous polymerization method), the esterification reaction (transesterification reaction) and the melt polycondensation reaction may each be carried out in one stage, but it is preferably carried out in a plurality of stages. preferable. When the esterification reaction (transesterification reaction) is performed in a plurality of stages, the number of reaction cans is preferably 2 to 3 cans. When the melt polycondensation is performed in a plurality of stages, the number of reaction cans is preferably 3 to 7.

The temperature of the esterification reaction (transesterification reaction) in the continuous polymerization method is usually 240 to 270 ° C, preferably 250 to 265 ° C. The pressure in the reaction vessel is usually 0.2 MPa or less, preferably 0.01 MPa.
~ 0.05 MPa. The temperature of the polycondensation reaction is usually 265 to 285 ° C, preferably 270 to 280.
C., and the pressure inside the reaction vessel is usually 1.5 hPa or less, preferably 0.5 hPa or less. The reaction time of the esterification reaction (transesterification reaction) is preferably 5 hours or less,
Particularly preferably, it is 2 to 3.5 hours. The reaction time of the polycondensation reaction is preferably 3 hours or less, particularly preferably 1 to 2 hours.

On the other hand, in the case of production by a batch reaction apparatus (batch polymerization method), when the produced polymer is extracted from the polymerization reaction can, the pressure inside the polymerization reaction can is 0.1 to 300 hPa,
The polymer is preferably withdrawn from the polymerization reaction can while maintaining the pressure at 5 to 50 hPa. This makes it possible to suppress fluctuations in the intrinsic viscosity (polymerization degree) of the polymer (copolymerized polyester) during the extraction process, and for example, the fluctuation range (minimum value to the minimum value of the intrinsic viscosity (IV) when 700 kg of polyester was produced. (Maximum value) can be suppressed to 0.05 dl / g or less, preferably 0.025 dl / g or less. In the production of polyester by a conventional batch reaction apparatus (batch polymerization method), the polymer is extracted from the polymerization reaction container by using nitrogen gas or the like to extract the polymer from the polymerization reaction container under pressure. However, in such a conventional method, the fluctuation range of the intrinsic viscosity (IV) of the polymer (copolymerized polyester) is 0.1 dl.
/ G or more.

When the method of extracting the polymer from the polymerization reaction can in which the pressure inside the can of the present invention is maintained at a reduced pressure is carried out, a means such as a gear pump is attached to the extraction port of the polymerization reaction container. preferable. If the gear pump means is not attached, it becomes difficult to efficiently extract the polymer from the depressurized reactor.

In the present invention, the temperature of the esterification reaction (transesterification reaction) in the batchwise polymerization method is usually 220 to 2
The temperature is 50 ° C, preferably 230 to 245 ° C. The pressure inside the reaction vessel is usually 0.2 to 0.4 MPa, preferably 0.25 to 0.30 MPa. Moreover, the polycondensation reaction may be carried out in one step or in a plurality of steps. If it is done in one step, gradually reduce the pressure and raise the temperature,
Final temperature is 260-280 ° C, preferably 265-
275 ℃, the final pressure is usually 3 hPa
The following is preferably 0.5 hPa or less. The reaction time of the esterification reaction or transesterification reaction is preferably 4 hours or less, particularly preferably 2 to 3 hours. The reaction time of the polycondensation reaction is preferably 5 hours or less, particularly preferably 2 to 4 hours.

In the present invention, the copolymerized polyester produced by polymerization is usually withdrawn in a strand form from an outlet provided at the bottom of the reaction can, cooled with water, and then cut into chips.

Examples of the antimony compound used as a polymerization catalyst in the present invention include antimony trioxide, antimony pentoxide, antimony acetate, antimony glycoside, and the like. Among these, antimony trioxide,
Antimony acetate and antimony glycoside can be preferably used, and antimony trioxide can be particularly preferably used.

Examples of the germanium compound include crystalline germanium dioxide, amorphous germanium dioxide, germanium tetraethoxide, germanium tetra n-butoxide and the like. Among these, crystalline germanium dioxide and amorphous germanium dioxide are preferred. , And amorphous germanium dioxide is particularly preferably used.

Examples of the titanium compound include alkoxides such as titanium tetraisopropoxide and titanium tetrabutoxide; titanyl ammonium oxalate, lithium titanyl oxalate, sodium titanyl oxalate, potassium titanyl oxalate, and titanyl barium oxalate. Examples of titanyl oxalate compounds include organic carboxylic acid titanium salts such as potassium acetyltitanate. Among these, titanium tetraisopropoxide, titanium tetrabutoxide, and potassium titanyl oxalate can be preferably used, and titanium tetrabutoxide can be particularly preferably used.

Examples of alkali metal compounds and alkaline earth metal compounds include hydroxides and hydrates of alkali metals and alkaline earth metals; lower fatty acids such as acetates, propionates and butyrates. Group carboxylic acid salts and hydrates thereof; aromatic carboxylic acid salts such as benzoate, 4-methylphenylcarboxylic acid salt and naphthylcarboxylic acid salts and hydrates thereof; alkoxides such as methoxide, ethoxide and the like. Among them, hydroxide and its hydrate, acetate and its hydrate are preferable. Here, examples of the alkali metal include Li, Na, and K, and examples of the alkaline earth metal include Mg, Ca, Sr, and Ba.
Etc. Specific examples of suitable alkali metal compounds include sodium acetate, sodium acetate trihydrate, potassium acetate, lithium acetate, lithium acetate dihydrate, lithium hydroxide, lithium hydroxide monohydrate, and among them, , Sodium acetate, lithium acetate dihydrate and lithium hydroxide monohydrate are particularly preferably used. Further, as preferable specific examples of the alkaline earth metal compound, calcium acetate, calcium acetate monohydrate, magnesium acetate,
Magnesium acetate tetrahydrate, barium acetate,
Among them, calcium acetate monohydrate, magnesium acetate 4
Hydrates are particularly preferably used.

Examples of the phosphorus compound include phosphoric acid, phosphorous acid, phosphonic acid and derivatives thereof, and preferable specific examples thereof include phosphoric acid, trimethyl phosphate, tributyl phosphate, triphenyl phosphate. , Monomethyl phosphate, dimethyl phosphate, monobutyl phosphate, dibutyl phosphate, phosphorous acid, trimethyl phosphite, tributyl phosphite, methylphosphonic acid, dimethyl methylphosphonate, dimethyl ethylphosphonate, dimethyl phenylphosphonate, phenylphosphone Examples thereof include diethyl acid and phenyl phosphonate diphenyl, and of these, trimethyl phosphate and phosphoric acid are particularly preferably used.

The copolymerized polyester of the present invention can be used as a material (raw material) for various molded products such as films, sheets, hollow molding containers, engineering plastics, fibers, etc., but films are particularly preferable. In particular, since it has high transparency (haze measured by the method described below is 15% or less, preferably 10% or less) and good solvent adhesion, labels for coating the outer peripheral surface of various articles, packaging of various articles, It is particularly preferable for a heat-shrinkable film used as a material for binding and the like. Further, in the present invention, by the electrostatic contact casting method, such a high transparency and a good solvent adhesiveness, a uniform thickness (the thickness distribution of the film measured by the method described below is less than 10%, preferably 6% or less ) Film can be produced at high speed.

The measuring methods of the main characteristic values in the present specification are described below. Intrinsic viscosity (IV) of polyester 1,1,2,2-tetrachloroethane / phenol (2:
(3 weight ratio) It was determined from the solution viscosity at 30 ° C. in a mixed solvent.

About 5 mg of a polyester composition sample (sample) was dissolved in 0.7 ml of a mixed solution of deuterated chloroform and trifluoroacetic acid (9/1 volume ratio), and ¹ H-NMR (device name: unity5 manufactured by Varian) was used.
00) was used.

About 5 to 10 g of metal atomic weight sample (sample) in polyester was put into a platinum crucible and ashed at about 550 ° C., then dissolved in 6N hydrochloric acid and evaporated to dryness, and the residue was dissolved in 1N hydrochloric acid. This solution was measured by atomic absorption spectrometry.

Melt resistivity of polyester (ρi (Ω ・
cm)) Two electrodes (stainless steel wire) were placed in a sample melted at 275 ° C., a current (i _o ) when a voltage of 120 V was applied was measured, and this was applied to the following formula to calculate. ρi (Ω · cm) = ( A / L) × (V / i o) [A: electrode area between ^(cm 2), L = distance between electrodes (c
m), V = voltage (V)]

Electrostatic adhesion of polyester An electrode made of tungsten wire is provided between the die of the extruder and the cooling drum, and 1 is provided between the electrode and the casting drum.
Apply a voltage of 0 to 15 KV and melt extrude at 275 ° C.,
Casting was performed, the surface of the obtained casting raw fabric was observed with the naked eye, and the casting speed was evaluated by the casting speed at which the occurrence of pinner bubbles began to occur. The higher the casting speed, the better the electrostatic adhesion.

Haze Measured according to JIS K7105. Film (thickness 4
(5 μm), a sample was cut and measured with a haze meter manufactured by Nippon Denshoku Industries Co., Ltd.

Uniformity of thickness of film 20 pieces of samples for thickness measurement prepared by cutting a film into a length of 50 cm and a width of 5 cm were prepared, and the length was measured using a contact type thickness meter KG60 / A manufactured by Anritsu Corporation. The thickness was measured in the direction, the thickness distribution was obtained based on the following formula, and the average value was used as the film thickness distribution. Thickness distribution = (maximum thickness−minimum thickness) / average thickness × 100 Solvent adhesiveness At room temperature, THF (tetrahydrofuran) 3.0 ± 0.
3 g / mm ² is applied in the longitudinal direction with a width of 2 ± 1 mm, and the film is immediately rolled and the ends are overlapped and adhered to form a tube. At this time, the state of the films (presence or absence of peeling between the films) was visually observed.

[0048]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Example 1 A continuous type polymerization equipment was used. High purity terephthalic acid (TPA), ethylene glycol (EG) and 1,4-cyclohexanedimethanol (C
The amount ratio of HDM) and diethylene glycol (DEG) is 1
A slurry of 00/80/19/1 (molar ratio) was continuously supplied, and the reaction was carried out under stirring at about 250 ° C. and 0.05 MPa for an average residence time of about 3 hours. The reaction product was transferred to a second esterification reactor and stirred at about 260 ° C. for 0.0
The reaction was carried out at 5 MPa for an average residence time of about 1 hour. The reaction product was transferred to the third esterification reactor and stirred for about 26
The reaction was carried out at 0 ° C. and 0.05 MPa to a predetermined reactivity. The end of the oligomer obtained at this time has an acid value of 300e.
In q / ton, the hydroxyl value was 1000 eq / ton. 12g of antimony trioxide was added to this oligomer.
/ L ethylene glycol solution as Sb atomic weight 250
ppm (content in the finally obtained polyester), magnesium oxide tetrahydrate as an ethylene glycol solution of 50 g / l, Mg atomic weight 90 ppm (content in the finally obtained polyester), sodium acetate 10 g /
l ethylene glycol solution as a Na atom weight of 10 pp
m (content in the finally obtained polyester), trimethyl phosphoric acid as an ethylene glycol solution of 65 g / l, P atomic weight of 42 ppm (content in the finally obtained polyester) are continuously fed to the third esterification reactor separately. Supplied. This esterification reaction product is continuously fed to the first polycondensation reactor, stirred at about 265 ° C. and 35 hPa for about 1 hour, and then stirred at the second polycondensation reactor for about 270.
Polycondensation was conducted at about 280 ° C. and 0.5 to 1.5 hPa for about 1 hour under stirring at the final polycondensation reactor for about 1 hour at 5 ° C. and 5 hPa.

The composition of the obtained polyester is TPA / E.
G / CHDM / DEG = 100 / 66.3 / 30.5 /
3.2 (molar ratio), intrinsic viscosity (IV) 0.75 dl /
g, Sb atomic weight (content) 250 ppm, Mg atomic weight (content) 85 ppm, Na atomic weight (content) 10 pp
The m and P atomic weights (contents) were 32 ppm.

Further, by continuously operating for 3 days under the above reaction conditions, 20 ton of polyester is produced per day,
When the intrinsic viscosity (IV) of the polyester produced every 2 hours and the amount (copolymerization amount) of the diethylene glycol component were measured, the IV fluctuation range per day (20 tons) was 0.
The fluctuation range of 023 dl / g and the amount of diethylene glycol component (copolymerization amount) was 0.15 mol%.

275 of the polyester produced above
When the melting specific resistance at ℃ was measured and the electrostatic adhesion was further investigated, the melting specific resistance was 0.20 × 10 ⁸ Ω · cm, and the casting speed, which is an index of the electrostatic adhesion, was 60 m / min. there were.

Then, according to a standard method, melt extrusion was carried out at 280 ° C., casting was carried out at a casting speed of 60 m / min, and the film was stretched 4 times in the transverse direction at 80 ° C. and then heat treated at 80 ° C. to obtain a film having a thickness of 45 μm When the haze of the film was measured, it was 4.5% and was excellent in transparency. The solvent adhesion of the film was examined and found to be good. The thickness distribution of the film is 4%,
It was excellent in thickness uniformity.

Example 2 A batch-type polymerization apparatus was equipped with 100 parts of high-purity terephthalic acid, 51 parts of ethylene glycol,
After charging 27.8 parts of 1,4-cyclohexanedimethanol, 1.0 part of diethylene glycol and sodium acetate in an amount such that the amount of Na is 10 ppm with respect to the produced polyester, and after substituting with nitrogen, under a nitrogen atmosphere and under a pressure of 0.25 MPa. The temperature was raised to 240 ° C over 30 minutes, and
After carrying out the esterification reaction by holding at 0 ° C. for 3 hours, antimony trioxide was added to the produced polyester with an Sb content of 25
An amount of 0 ppm, an amount of magnesium acetate tetrahydrate that produces 90 ppm of Mg with respect to the polyester, and an amount of trimethyl phosphate that produces P of 42 p with respect to the produced polyester.
An amount of pm was added. Then the system is 1.5hPa in 75 minutes
Depressurize to below, start heating at the same time, and finally 280
The polymerization reaction was carried out at 0 ° C. Polymerization was completed 60 minutes after the start of depressurization. 5 to 15 hP in the system when extracting polymer
It was taken out as a strand for 40 minutes while keeping it at a, cooled in a clean bath filled with water, pelletized and recovered using a cutter.

The composition of the obtained polyester was TPA / E.
G / CHDM / DEG = 100 / 65.5 / 30.8 /
It was 3.7 (molar ratio). Also, the intrinsic viscosity (IV) was 0.755 dl / g at the start of extraction, and 4 after extraction.
The intrinsic viscosity (IV) after 0 minutes was 0.750 dl / g, and the fluctuation range was small. Also, the Sb atomic weight (content) is 225
ppm, Mg atomic weight (content) was 82 ppm, Na atomic weight (content) was 9 ppm, and P atomic weight (content) was 29 ppm. 700k polyester as above
When the g was produced, the fluctuation range of the intrinsic viscosity (IV) was 0.01.
It was 5 dl / g.

275 of the polyester produced above
When the melting specific resistance at ℃ was measured and the electrostatic adhesion was further investigated, the melting specific resistance was 0.228 × 10 ⁸ Ω · cm,
The casting speed, which is an index of electrostatic adhesion, is 58m /
It was a minute.

Next, a casting film having a thickness of 45 μm was prepared in the same manner as in Example 1 except that the casting speed was 58 m / min, and the haze of the film was measured.
The transparency was excellent at 5%. In addition, the solvent adhesion of the film was examined and found to be good. The thickness distribution of the film was 5%, which was excellent in thickness uniformity.

Comparative Example 1 In Example 1, the first esterification reactor was composed of high-purity terephthalic acid (TPA), ethylene glycol (EG), and 1,4-cyclohexanedimethanol (CHDM). The amount ratio of 10
A polyester was produced in the same manner as in Example 1 except that a slurry of 0 / 68.0 / 32.0 (molar ratio) was used.

The composition of the obtained polyester was TPA / E.
G / CHDM / DEG = 100 / 68.7 / 30.5 /
0.8 (molar ratio), intrinsic viscosity (IV) 0.75 dl /
It was g.

A film having a thickness of 45 μm was produced from this polyester in the same manner as in Example 1, and the haze of the film was measured. As a result, it was 4.5, and transparency was excellent. When the solvent adhesion of the film was examined, the adhesion of the film was insufficient.

Comparative Example 2 A polyester was produced in the same manner as in Example 2 except that diethylene glycol was omitted from the raw material monomer. The composition of the obtained polyester is TP
A / EG / CHDM / DEG = 100 / 68.0 / 3
0.5 / 1.3 (molar ratio), and the intrinsic viscosity (IV) at the start of extraction was 0.745 dl / g.

A film having a thickness of 45 μm was produced from this polyester in the same manner as in Example 2, and the haze of the film was measured. As a result, the film was 4.6 and was excellent in transparency. When the solvent adhesion of the film was examined, the adhesion of the film was insufficient.

Example 3 A polyester was produced in the same manner as in Example 2 except that the pressure inside the reaction vessel at the time of extracting the polymer was set to 0.2 MPa. The composition of the obtained polyester was the same as in Example 2, and the intrinsic viscosity (IV) at the start of extraction was 0.750 dl / g, which was 4 after extraction.
The intrinsic viscosity (IV) after 0 minutes was 0.68 dl / g, and the fluctuation of IV was large.

The intrinsic viscosity (IV) is 0.750 dl /
A film having a thickness of 45 μm was produced in the same manner as in Example 2 using g of polyester, and the haze of the film was measured. As a result, the film was 4.0 and was excellent in transparency. The solvent adhesion of the film was examined and found to be good.

(Example 4) Magnesium oxide tetrahydrate,
A polyester was produced in the same manner as in Example 1 except that sodium acetate and trimethyl phosphoric acid were not supplied.
The composition of the obtained polyester was substantially the same as that of Example 1, but the electrostatic adhesion was examined and the melt specific resistance was 2.5.
The casting speed, which was 3 × 10 ⁸ Ω · cm and was an index of electrostatic adhesion, was 15 m / min. Next, a film having a thickness of 45 μm was produced in the same manner as in Example 1 except that the casting speed was changed to 10 m / s, and the haze of the film was measured. The solvent adhesion of the film was examined and found to be good. The thickness distribution of the film was 4%, which was excellent in thickness uniformity.

[0066]

As is apparent from the above description, according to the present invention, it has a high degree of polymerization, high transparency, and good solvent adhesiveness, and is particularly useful as a raw material for films such as heat shrink films. And a method for producing a polyester capable of stably producing the polyester. Furthermore, it is possible to provide a polyester which has the above-mentioned preferable properties (high polymerization degree, high transparency, and good solvent adhesiveness) and can be rapidly formed into a film having a high thickness uniformity. It is possible to provide a method for producing polyester, which enables stable production of polyester.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J029 AA03 AB01 AB05 AC02 BA03                       BD07A BF09 CB06A HA01                       HB01 JA091 JB131 JB171                       JF011 JF021 JF031 JF041                       JF131 JF141 JF151 JF161                       JF321 JF361 JF471 KB02                       KB05 KD05

Claims (8)

[Claims] 1. The main dicarboxylic acid component consists of terephthalic acid, and 50 to 85 mol% of ethylene glycol, 10 to 45 mol% of 1,4-cyclohexanedimethanol and 1.5 to 1.5 mol of diethylene glycol in all glycol components.
-7 mol% and intrinsic viscosity 0.7-0.85 dl / g
A copolymerized polyester characterized in that 2. A polyester obtained by using at least one selected from an antimony compound, a germanium compound and a titanium compound as a polymerization catalyst, wherein the content of the antimony compound in the polyester is 100 to 500 ppm as Sb atomic weight, The content of the germanium compound in the polyester is 15 to 25 as Ge atomic weight.
0 ppm, the content of titanium compound in the polyester is T
The copolyester according to claim 1, which has an i atomic weight of 5 to 50 ppm. 3. A polyester obtained by using, as a polymerization catalyst, at least one selected from an antimony compound, a germanium compound and a titanium compound, an alkali metal compound, an alkaline earth metal compound and a phosphorus compound. The content of the antimony compound in the polyester is 100 to 500 ppm as the Sb atomic weight, and the content of the germanium compound in the polyester is 15 to 25 as the Ge atomic weight.
0 ppm, the content of titanium compound in the polyester is T
i atomic weight is 5 to 50 ppm, and the content of the alkali metal compound in the polyester is the alkali metal atomic weight (M1)
5 to 30 ppm and the content of the alkaline earth metal compound in the polyester is the alkaline earth metal atomic weight (M
2) is 50 to 250 ppm, the alkali metal atomic weight (M1) and the alkaline earth metal atomic weight (M2) have the relationship of the following formula (I), and the alkali metal atomic weight (M1) and the alkali The relation between the atomic weight of the earth metal (M2) and the atomic weight of P (p) as the content of the phosphorus compound in the polyester is represented by the following formula (II).
The copolymerized polyester according to claim 1, which satisfies: Formula (I): 2 ≦ M2 / M1 (weight ratio) ≦ 40 Formula (II): 0.5 ≦ (M1 + M2) / p (weight ratio) ≦ 10 4. The melting specific resistance at 275 ° C. is 0.1 × 10.
^The copolyester according to claim 1, which has a viscosity of ^{8 to} 0.75 × 10 ⁸ Ω · cm. 5. A method for producing the copolyester according to claim 1, wherein the amount of diethylene glycol is 0.5 to 0.5 based on the total amount of glycol.
A method for producing a polyester, which comprises polymerizing a raw material monomer containing 6.5 mol% by a continuous polymerization method. 6. A method for producing the copolyester according to claim 1, wherein diethylene glycol is 0.5 to
The raw material monomer containing 6.5 mol% was polymerized by a batch-type polymerization method, and the produced polymer was heated to a pressure in the can of a polymerization reaction vessel of 0.1 to 0.1%.
A method for producing polyester, wherein the polyester is extracted from a polymerization reaction can while maintaining the pressure at 300 hPa. 7. A polymerization catalyst comprising at least one selected from an antimony compound, a germanium compound and a titanium compound, and the content of the antimony compound in the polyester produced is 100 to 100 as Sb atomic weight.
500 ppm, the content of the germanium compound in the polyester is 15 to 250 pp as Ge atomic weight
The method for producing a polyester according to claim 5 or 6, wherein the content of m and the titanium compound in the polyester produced is 5 to 50 ppm in terms of Ti atomic weight. 8. An alkali metal compound as a polymerization catalyst,
The method for producing a polyester according to claim 7, wherein an alkaline earth metal compound and a phosphorus compound are further used and the following formulas (I) and (II) are satisfied. Formula (I): 2 ≦ M2 / M1 (weight ratio) ≦ 40 Formula (II): 0.5 ≦ (M1 + M2) / p ≦ 10 (weight ratio) In the formula, M1 is the polyester produced by the alkali metal compound. Alkali metal atomic amount as content, M2 is alkaline earth metal atomic amount as content in polyester produced by alkaline earth metal compound, and p is P atomic amount as content in polyester produced by phosphorus compound.