JP2010018781A - Polyester resin composition and method for producing the same - Google Patents

Abstract

A polyester composition excellent in color tone and productivity and a method for producing the same are provided.
A polyester composition comprising a terephthalic acid unit or naphthalenedicarboxylic acid unit as an acid component, and an ethylene glycol unit as a glycol component, wherein the antimony compound has an antimony atom of 50 ppm to 300 ppm and the phosphorus compound has a phosphorus atom of 30 ppm or more. 600 ppm or less, magnesium atom as a magnesium compound, 20 ppm or more and 100 ppm or less, antioxidant is 0.01 wt% or more and 3.0 wt% or less, b value is 3 or less, L value is 60 or more, and the following formula is satisfied. A polyester composition is used. 0.5 ≦ P / Sb ≦ 2.0 (I) 0.5 ≦ A / Pc ≦ 3.0 (II) (where P and Sb are the contents of phosphorus atom and antimony atom, respectively, and Pc is the phosphorus compound content) Content, A represents the content of antioxidant, and the unit is ppm.)
[Selection figure] None

Description

  The present invention relates to a polyester resin composition and a method for producing the same. In particular, the present invention relates to a polyester resin composition capable of easily forming a molded product having excellent color tone, and a method for producing the same.

  Polyester has excellent physical and chemical properties and is widely used in films, fibers, sheets and the like. In particular, the polyester film has excellent properties in heat resistance, solvent resistance, mechanical properties, optical properties, magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials, optical materials, general industrial materials, etc. It is used for many purposes.

  In particular, high-purity raw materials are mainly used for optical polyester resins because color tone, light transmittance, foreign matter, etc. are regarded as important, but they are still not sufficient and are improved by various additives. ing.

  For example, Patent Document 1 describes a polyester composition whose color tone and heat resistance are improved with a phosphite compound, but the effect of improving the color tone is insufficient only with the phosphite compound, and the L value is lowered due to reduced antimony. There is a tendency.

  Patent Document 2 presents a comparative example in which the same applicant as Patent Document 1 is inadequate because the L value is lowered only by the phosphite compound, and as an improvement, the b value and L value by the boron compound are presented. However, boron compounds are harder to handle than phosphorus compounds generally used in polyester, and borate esters, which are by-products, are PRTR Method Class I designated chemical substances. However, its boiling point is low and it is easy to be released out of the system.

JP 2006-274147 A JP 2007-145940 A

  The objective of this invention is providing the polyester resin composition excellent in color tone and productivity, and its manufacturing method.

  In order to achieve the above object, the present invention provides a polyester resin composition comprising a terephthalic acid unit and / or a naphthalenedicarboxylic acid unit as an acid component and an ethylene glycol unit as a glycol component, wherein the antimony atom is 50 ppm to 300 ppm, phosphorus 30 ppm to 600 ppm atoms, 20 ppm to 100 ppm magnesium atoms, 0.01 wt% to 3.0 wt% antioxidant, b value indicating color tone of 3 or less, L value of 60 or more, It is a polyester resin composition satisfying the formula.

0.5 ≦ P / Sb ≦ 2.0 (I)
0.5 ≦ A / Pc ≦ 3.0 (II)
(However, P and Sb are the contents of phosphorus atom and antimony atom, Pc is the content of phosphorus compound, A is the content of antioxidant, and the unit is ppm (weight basis).)

  According to the present invention, it is possible to provide a polyester resin composition excellent in color tone, suitable for optical applications, and particularly advantageous in cost, and a method for producing the same.

  The polyester resin composition of the present invention is a polyester resin composition containing a terephthalic acid unit and / or a naphthalenedicarboxylic acid unit as an acid component and an ethylene glycol unit as a glycol component, wherein the antimony atom is 50 ppm to 300 ppm and the phosphorus atom is 30 ppm to 600 ppm, magnesium atoms from 20 ppm to 100 ppm, antioxidant from 0.01 wt% to 3.0 wt%, b value indicating color tone is 3 or less, L value is 60 or more, A satisfactory polyester resin composition.

0.5 ≦ P / Sb ≦ 2.0 (I)
0.5 ≦ A / Pc ≦ 3.0 (II)
(However, P and Sb are the contents of phosphorus atom and antimony atom, Pc is the content of phosphorus compound, A is the content of antioxidant, and the unit is ppm (weight basis).)
The acid component contained in the polyester resin composition of the present invention needs to be a terephthalic acid unit and / or a naphthalenedicarboxylic acid unit from the viewpoint of heat resistance and mechanical strength. Furthermore, as terephthalic acid, what contains 9 ppm or more of 9-fluorenone-2,6-dicarboxylic acid, that is, an inexpensive medium-purity terephthalic acid produced by omitting the purification step, is cost effective. It is advantageous, and more preferably 1 to 10 ppm from the viewpoint of color tone.

  9-Fluorenone-2,6-dicarboxylic acid is generally said to be a color-causing substance for polyester, and since the b value of the polyester resin is high even at several ppm, it is removed as much as possible in optical applications, and has a high purity. It is usual to use terephthalic acid.

  On the other hand, according to the present invention, even a polyester resin composition using medium-purity terephthalic acid containing 9-fluorenone-2,6-dicarboxylic acid can improve the color tone to a level that can be used as an optical application. .

  The glycol component of the present invention needs to be an ethylene glycol unit from the viewpoint of heat resistance and mechanical strength.

  The polyester resin composition of the present invention may contain a copolymer component in a range of less than 5 mol% with respect to the total acid component. If it is contained in an amount of 5 mol% or more, mechanical properties and thermal properties may be deteriorated, and the color tone may be deteriorated.

  In the present invention, the amount of the phosphorus compound contained in the polyester resin composition needs to be 30 ppm or more and 600 ppm or less as a phosphorus atom, preferably 50 to 300 ppm, particularly polymerization reactivity, from the viewpoint of color tone. From this point, it is preferably 50 to 150 ppm. If it is less than 30 ppm, a sufficient color tone improving effect cannot be obtained. If it exceeds 600 ppm, the polymerization reaction is delayed, or antimony trioxide as a polymerization catalyst is reduced, and the L value is greatly reduced.

  In the present invention, the phosphorous compound is preferably a phosphonite compound and / or a phosphite compound from the viewpoint of color tone. When no phosphonite compound and / or phosphite compound is contained, the b value improving effect tends to be insufficient when medium purity terephthalic acid is used. In addition, the amount of phosphorus atoms contained in the phosphonite compound and the phosphite compound is preferably less than 10 wt% in terms of heat resistance and color tone, and further, the reactivity with the antimony compound is low, and the L value is lowered. In terms of difficulty, it is preferable to have two or more phosphorus atoms in one molecule. A compound in which the amount of phosphorus atoms contained in the phosphonite compound and the phosphite compound exceeds 10 wt% also has an effect of lowering the b value, but has a high ability to reduce antimony trioxide to antimony, and the L value tends to decrease. In addition, low molecular weight compounds such as phosphorous acid are liable to react with alkaline earth metals to generate foreign matters, so that attention must be paid to the catalyst composition.

  Further, a phosphite compound that is less likely to reduce antimony trioxide than a phosphonite compound is preferable.

  As the phosphonite compound in the present invention, 2,2′-methylenebis (4,6-di-tert-butylphenyl) (2,4-di-tert-butylphenyl) phosphite, 2,2′-methylenebis (4,4) 6-di-tert-butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite, 2,2′-methylenebis (4-methyl-6-tert-butylphenyl) (2-tert-butyl-4) -Methylphenyl) phosphite, 2,2'-ethylidenebis (4-methyl-6-tert-butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite, tetrakis (2,4-tert-butyl) Phenyl) (1,1-biphenyl) -4,4′-diylbisphosphonite, tetrakis (2,4-tert-butyl) Phenyl-5-methyl) (1,1-biphenyl) -4,4′-diylbisphosphonite and the like, among others, tetrakis (2,4-tert-butylphenyl) (1,1-biphenyl) -4 , 4′-diylbisphosphonite and tetrakis (2,4-tert-butylphenyl-5-methyl) (1,1-biphenyl) -4,4′-diylbisphosphonite are preferred because they have a large b-value reducing effect.

  On the other hand, the phosphite compound in the present invention includes phosphorous acid, triethyl phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (4-methyl-2,6-di). -Tert-butylphenyl) pentaerythritol diphosphite, bis (2,4-dimethyl-6-tert-butylphenyl) pentaerythritol diphosphite, bis (3,5-di-tert-butylphenyl) pentaerythritol diphosphite Phyto, bis (2,4,6-tri-tert-butylphenyl) pentaerythritol diphosphite, bis (2-methyl-4,6-di-tert-butylphenyl) pentaerythritol diphosphite, bis (nonylphenyl) ) Pentaerythritol diphosphite, bis (tri Syl) pentaerythritol diphosphite, tris (2,4-tert-butylphenyl) phosphite, tris (2,4,6-tri-butylphenyl) phosphite, tris (4-methyl-2,6-di-) tert-butylphenyl) phosphite, tris (4-methyl-2,6-di-tert-butylphenyl) phosphite, and the like. Among these, bis (4-methyl-2,6-di-tert-butylphenyl) pentaerythritol diphosphite, tris (2,4-tert-butylphenyl) phosphite, bis (2,4-di-tert) -Butylphenyl) pentaerythritol diphosphite and bis (nonylphenyl) pentaerythritol diphosphite are preferable, and bis (4-methyl-2,6-di-tert) is excellent in heat resistance or hydrolysis resistance of the compound. -Butylphenyl) pentaerythritol diphosphite or tris (2,4-tert-butylphenyl) phosphite is preferred.

  The polyester resin composition of the present invention may contain other phosphorus compounds. For example, phosphoric acid, trimethyl phosphate, ethyl diethylphosphonoacetic acid and the like can be mentioned, and the content is preferably less than 30 ppm in terms of phosphorus atom.

  In the antimony compound of the present invention, the content of antimony atoms in the polyester resin composition needs to be 50 ppm or more and 300 ppm or less, and more preferably 50 ppm or more and 150 ppm or less from the viewpoint of color tone. If it is less than 50 ppm, sufficient polymerization reactivity cannot be obtained, and if it exceeds 300 ppm, the antimony metal produced by reduction of the antimony compound is precipitated, and the L value is lowered.

  In the present invention, examples of the antimony compound include antimony trioxide, antimony pentoxide, and the like, and antimony trioxide is preferable from the viewpoint of reactivity and heat resistance.

  The magnesium compound in the present invention needs to be 20 ppm or more and 100 ppm or less as the content of magnesium atoms in the polyester resin composition. When improving only the color tone, the smaller the amount of magnesium compound, the better. However, from the viewpoint of heat resistance, electrostatic application characteristics, and color tone, it is preferably 30 ppm or more and 70 ppm or less. If it is less than 20 ppm, the electrostatic application characteristics in film formation may be reduced, and stable film formation may be difficult. If it exceeds 100 ppm, the heat resistance is lowered and the b value tends to increase.

  As the magnesium compound in the present invention, magnesium acetate is preferred.

  The antioxidant in the present invention is obtained by removing the phosphonite compound and the phosphite compound. For example, hindered phenol compounds, lactone compounds, hydroxylamine compounds, sulfur compounds, hindered amine compounds can be mentioned. Preferably there is. Specifically, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) Propionate, N, N′-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionamide] and the like can be mentioned, among which pentaerythritol tetrakis [ 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] is preferable from the viewpoint of heat resistance.

The ratio of phosphorus atoms and antimony atoms contained in the polyester resin composition of the present invention must satisfy the following formula (I). Furthermore, in terms of polymerization reactivity and color tone, P / Sb is 0.8 or more. It is preferable that it is 1.5 or less.
0.5 ≦ P / Sb ≦ 2.0 (I)
(Here, P represents the content of phosphorus atoms, Sb represents the content of antimony atoms, and the unit is ppm (weight basis).)
When P / Sb is less than 0.5, a sufficient color tone improving effect may not be obtained, and when it exceeds 2.0, the polymerization reaction may be delayed.

The ratio of the antioxidant and the phosphorus compound contained in the polyester resin composition of the present invention needs to satisfy the following formula (II), and further A / Pc is 0.8 or more and 1.5 or less. It is preferable in terms of heat resistance and color tone.
0.5 ≦ A / Pc ≦ 3.0 (II)
(Here, A represents the content of the antioxidant, Pc represents the content of the phosphorus compound, and the unit is ppm (weight basis))
When A / Pc is less than 0.5, antimony trioxide is reduced and the L value is significantly reduced. If it exceeds 3.0, gel may be formed by thermal decomposition of the antioxidant.

  Specifically, the polyester resin composition of the present invention can be produced by the following method.

  That is, in the method for producing a polyester resin composition from terephthalic acid and / or naphthalenedicarboxylic acid and ethylene glycol, the antimony compound is converted to an antimony atom after the esterification reaction is completed until the intrinsic viscosity reaches 0.3. 50 ppm to 300 ppm, phosphonite compound and / or phosphite compound as phosphorus atom, 30 ppm to 600 ppm, magnesium compound as magnesium atom, 20 ppm to 100 ppm, antioxidant 0.01 wt% to 3.0 wt% When adding so that the formula (I) is satisfied, the phosphonite compound and / or the phosphite compound and the antioxidant are mixed and added so as to satisfy the following formula (II) Polyester production It is the law.

0.5 ≦ P / Sb ≦ 2.0 (I)
0.5 ≦ A / Pc ≦ 3.0 (II)
(However, P and Sb are the contents of phosphorus atom and antimony atom, Pc is the contents of phosphonite compound and phosphite compound, A is the content of antioxidant, and the unit is ppm (weight basis). )
Specifically, bishydroxyethylene terephthalate was melted at 250 ° C. in a nitrogen atmosphere, and terephthalic acid (containing 5 ppm of 9-fluorenone-2,6-dicarboxylic acid) and ethylene glycol slurry (weight ratio) : Ethylene glycol / terephthalic acid = 1.13) is fed over 3 hours to proceed with the esterification reaction. When the esterification rate reaches 90% or more, antimony trioxide, magnesium acetate, phosphoric acid, phosphine A phyto compound (and / or a phosphonite compound) and a hindered phenol antioxidant are sequentially added.

  At this time, terephthalic acid is preferably 1 to 10 ppm from the viewpoint of color tone because it can be produced at a lower cost when relatively inexpensive terephthalic acid containing 9 ppm of 9-fluorenone-2,6-dicarboxylic acid is used. More preferably.

  In addition, in order to improve the color tone of the polyester resin composition, the ratio of the total phosphorus compound to the antimony compound and the ratio of the total phosphonite compound and phosphite compound to the antioxidant are represented by the following formula (I) ( It is necessary to satisfy II).

0.5 ≦ P / Sb ≦ 2.0 (I)
0.5 ≦ A / Pc ≦ 3.0 (II)
(However, P and Sb are the contents of phosphorus atom and antimony atom, Pc is the contents of phosphonite compound and phosphite compound, A is the content of antioxidant, and the unit is ppm (weight basis). In addition, as a method for adding a phosphonite compound, a phosphite compound, and an antioxidant, it is preferable to add them in advance in terms of color tone. By mixing in advance, the reduction reaction of antimony trioxide by a phosphonite compound or a phosphite compound can be efficiently suppressed. Furthermore, it is preferable in terms of productivity to add these mixtures as an ethylene glycol slurry or an ethylene glycol solution, and the concentration is preferably 20% by weight or less. By using a slurry or solution of ethylene glycol, it is possible to prevent adhesion and deposition on the addition path.

  After adding various additives in this way, the polyester resin of the present invention is gradually heated and depressurized, and finally reacted at 290 ° C. and 1 Torr or less until a predetermined degree of polymerization is reached. A composition can be produced.

  The polyester resin composition of the present invention needs to have a b value indicating a color tone of 3 or less and an L value of 60 or more, and more preferably a b value of 2 or less in terms of color tone and light transmittance. . When the b value exceeds 3, yellowishness is produced, which is not preferable for optical applications. On the other hand, when the L value is less than 60, the light transmittance is lowered and the color becomes dark, which is not suitable for optical use.

  Since the polyester resin composition of the present invention is excellent in color tone, it can be suitably used as a raw material for optical films.

  Hereinafter, the present invention will be described in more detail with reference to examples. The characteristics in the examples were measured as follows.

(A. Intrinsic viscosity)
It measured at 25 degreeC using the o-chlorophenol solvent.

(B. Measurement of b value and L value of polyester chip)
Using a SM-color computer (SM-T) manufactured by Suga Test Instruments Co., Ltd., the reflection method was used.

(C. Amount of metal atoms in polyester resin composition)
Antimony atoms, phosphorus atoms, and magnesium atoms were quantified by fluorescent X-ray analysis (manufactured by Horiba, Ltd., MESA-500W type).

(D. Amount of terminal carboxyl group of polyester resin composition)
Measured by the method of Malice. (Reference M. J. Malice, F. Huizinga. Anal. Chim. Acta, 22 363 (1960))
(E. Measurement of 9-fluorenone-2,6-dicarboxylic acid content)
0.1 g of terephthalic acid was dissolved in 7 ml of 0.5N aqueous ammonia and 3 ml of an internal standard solution (0.1 ml g of nitrobenzene / 1 ml of acetonitrile), and 5 μl was injected and analyzed by HPLC.

  The analysis conditions are as follows.

Column: CAPCELL PAC C18 4.6φ × 25cm
TYPE UG 120 Angstrom 5μm
Mobile phase: A liquid 1% acetic acid aqueous solution
Liquid B Acetonitrile Detector: UV 254 nm (RANGE = 0.002 AUFS)
Column temperature: 50 ° C
Mobile phase flow rate: 1.2 ml / min (0 minutes) → 1.44 ml / min (80 minutes)
Grade conditions: acetonitrile concentration 10% (0 minutes) → 22.8% (80 minutes)
Analysis time: 80 minutes The content in the polyester composition was also analyzed in the same manner after the polyester composition was hydrolyzed with alkali to form a monomer.

(F. Polymerization reactivity evaluation)
The time until reaching the intrinsic viscosity of 0.60 was evaluated as follows in comparison with the blank (Reference Example 1).

◎ ・ ・ ・ Delay is less than 15 minutes ○ ・ ・ ・ Delay is from 15 minutes to less than 30 minutes △… Delay is from 30 minutes to less than 45 ×× Delay is 45 minutes or more (Reference Example 1)
132.3 parts by weight of bishydroxyethyl terephthalate is melted and stirred at 250 ° C. in a nitrogen atmosphere. Thereafter, the reaction system is all under a nitrogen atmosphere. Thereafter, a slurry of 86.5 parts by weight of terephthalic acid (containing 2 ppm of 9-fluorenone-2,6-dicarboxylic acid) and 36.5 parts by weight of ethylene glycol is obtained with a snake pump. Feeding over 5 hours, the esterification reaction was carried out in the range of 245 ° C. to 250 ° C., and 132.3 parts by weight of the reaction product was transferred to the polymerization can at a reaction rate of about 90%. 0.035 parts by weight of magnesium acetate tetrahydrate, 0.012 parts by weight of antimony trioxide, and 0.005 parts by weight of phosphoric acid were added at intervals of 5 minutes to initiate the polymerization reaction. The final temperature reached was 290 ° C., the degree of vacuum was less than 0.1 torr, and the polymerization reaction time was 2 hours 30 minutes.
(Reference Example 2)
A polyester composition was obtained in the same manner as in Reference Example 1 except that terephthalic acid was changed to high-purity terephthalic acid (less than 1 ppm of 9-fluorenone-2,6-dicarboxylic acid).

Example 1
Instead of phosphoric acid, 0.1 part by weight of pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals: IRGANOX 1010) and bis (4-methyl- 2,6-di-tert-butylphenyl) pentaerythritol diphosphite (manufactured by Asahi Denka: PEP24G) is the same as Reference Example 1 except that 0.1 part by weight is dispersed in 4 parts by weight of ethylene glycol and added in the form of a slurry. Thus, a polyester composition was obtained.

Example 2
Instead of phosphoric acid, 0.1 part by weight of pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals: IRGANOX 1010) and bis (4-methyl- 2,6-di-tert-butylphenyl) pentaerythritol diphosphite (manufactured by Asahi Denka: PEP24G) is the same as Reference Example 2 except that 0.1 part by weight is dispersed in 4 parts by weight of ethylene glycol and added in the form of a slurry. Thus, a polyester composition was obtained.

Comparative Example 1
A polyester composition was obtained in the same manner as in Example 1 except that pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (manufactured by Ciba Specialty Chemicals: IRGANOX 1010) was not added. .

Examples 3-5
A polyester composition was obtained in the same manner as in Example 1 except that the content and type of the polymerization catalyst, phosphorus compound, antioxidant, magnesium acetate, and 9-fluorenone-2,6-dicarboxylic acid were changed.

Claims (7)

A polyester resin composition containing a terephthalic acid unit and / or a naphthalenedicarboxylic acid unit as an acid component, and an ethylene glycol unit as a glycol component, and having an antimony atom of 50 ppm to 300 ppm, a phosphorus atom of 30 ppm to 600 ppm, and a magnesium atom A polyester resin composition containing 20 ppm or more and 100 ppm or less, an antioxidant of 0.01 wt% or more and 3.0 wt% or less, a color tone b value of 3 or less, an L value of 60 or more, and satisfying the following formula: .
0.5 ≦ P / Sb ≦ 2.0 (I)
0.5 ≦ A / Pc ≦ 3.0 (II)
(However, P and Sb are the contents of phosphorus atom and antimony atom, Pc is the content of phosphorus compound, A is the content of antioxidant, and the unit is ppm (weight basis).)   The polyester resin composition according to claim 1, wherein the antioxidant is a hindered phenol compound.   The polyester resin composition according to any one of claims 1 and 2, which contains 1 ppm or more of 9-fluorenone-2,6-dicarboxylic acid. In the method for producing a polyester resin composition from terephthalic acid and / or naphthalenedicarboxylic acid and ethylene glycol, 50 ppm of antimony compounds as antimony atoms after the end of the esterification reaction until the intrinsic viscosity reaches 0.3. 300 ppm or less, phosphonite compound and / or phosphite compound as phosphorus atoms, 30 ppm or more and 600 ppm or less, magnesium compound as magnesium atoms, 20 ppm or more and 100 ppm or less, antioxidant 0.01 wt% or more and 3.0 wt% or less When adding to the above, it is added so as to satisfy the formula (I), and the phosphonite compound and / or phosphite compound and the antioxidant are mixed and added so as to satisfy the following formula (II). Polyester characterized by Method for producing a fat composition.
0.5 ≦ P / Sb ≦ 2.0 (I)
0.5 ≦ A / Pc ≦ 3.0 (II)
(However, P and Sb are the contents of phosphorus atom and antimony atom, Pc is the contents of phosphonite compound and phosphite compound, A is the content of antioxidant, and the unit is ppm (weight basis). )   The method for producing a polyester resin composition according to claim 4, wherein terephthalic acid containing 1 ppm or more of 9-fluorenone-2,6-dicarboxylic acid is used as the acid component.   The method for producing a polyester resin composition according to claim 4, wherein a phosphonite compound and / or a phosphite compound, an antioxidant and ethylene glycol are mixed and added.   The method for producing a polyester resin composition according to any one of claims 4 to 6, wherein the phosphonite compound and / or the phosphite compound contains two or more phosphorus atoms in one molecule.