JP2000119382A - Polyester polymerization catalyst, production of polyester and polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject catalyst that has the catalytic activity comparable to that of an antimony compound and can produce polyesters useful for producing formed products such as fibers, films, bottles without occurrence of blackening and formation of foreign substance by using iron oxide of an average primary particle size smaller than a prescribed one. SOLUTION: The objective iron oxide has an average primary particle size of <=100 nm or a specific surface area of >=10 m2/g. In preferred embodiments, this polyester polymerization catalyst is used to produce polyesters, for example, poly(ethylene terephthalate), poly(ethylene 2,6-naphthalate) or the like and the amount of the catalytic iron oxide to be added is 10-1,000 ppm based on the polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyester polymerization catalyst, a method for producing a polyester and a polyester. More specifically, the present invention relates to a method for producing a polyester having an average primary particle diameter of 100 nm or less or a specific surface area without using an antimony compound. Polyester polymerization catalyst which is iron oxide of 10 m ² / g or more, a method for producing polyester using the catalyst, and an average primary particle diameter of 100 nm or less, or a specific surface area of 10 m ² / g
The present invention relates to a polyester containing iron oxide.

[0002]

2. Description of the Related Art Polyester, especially polyethylene terephthalate (hereinafter abbreviated as PET) has excellent mechanical properties and chemical properties, and is applicable to various uses such as fibers for clothing and industrial materials, and packaging. It is applied to various films and sheets for tapes and magnetic tapes, and molded products such as bottles and engineering plastics.

[0003] In the industrial production of PET, bis (2-hydroxyethyl) terephthalate is produced by esterification or transesterification of terephthalic acid or dimethyl terephthalate with ethylene glycol. Obtained by polymerization. As a catalyst used in the polymerization, antimony trioxide is widely used. Antimony trioxide is a catalyst which is inexpensive and has excellent catalytic activity, but has a problem that darkening or foreign matter is generated in PET due to precipitation of metal antimony during polymerization. In addition, environmental issues have recently raised concerns about the safety of antimony. Under these circumstances, polyesters containing no antimony have been desired.

[0004] Attempts have been made to use antimony trioxide as a polymerization catalyst and to suppress the occurrence of blackening and foreign matter in PET. For example, in Japanese Patent No. 2666502, the use of a compound of antimony trioxide, bismuth and selenium as a polymerization catalyst suppresses the formation of black foreign matter in PET. Japanese Patent Application Laid-Open No. 9-291141 describes that when antimony trioxide containing sodium and iron oxides is used as a polymerization catalyst, the precipitation of antimony metal is suppressed. However, these polymerization catalysts cannot achieve the purpose of a polyester containing no antimony after all.

On the other hand, JP-A-8-157580 attempts to reduce toxicity by using antimony trioxide and an iron compound together as a polymerization catalyst. The use of an organic iron compound as a polymerization catalyst without using antimony trioxide is exemplified in, for example, US Pat. No. 2,740,768, but it cannot be said that the iron compound alone does not have sufficient catalytic activity. In addition, it has not been reported that an inorganic iron oxide generally used as a pigment or ferrite has sufficient activity as a polymerization catalyst.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to a novel polyester polymerization catalyst other than an antimony compound having catalytic activity comparable to that of an antimony compound, a method for producing a polyester using the polymerization catalyst, and a method for producing a polyester produced by the method. It provides polyester.

[0007]

The present inventors have conducted intensive studies with the aim of solving the above-mentioned problems. As a result, iron oxides (particle diameter of several micrometers or more) usually used as pigments and ferrites are made of polyester. Although the activity was low as a polymerization catalyst, it was found that when the iron oxide was made into ultrafine particles, it had sufficient activity as a polymerization catalyst.

That is, according to the present invention, the average primary particle size is 10
A polyester polymerization catalyst that is iron oxide of 0 nm or less,
The polyester polymerization catalyst is an iron oxide having a specific surface area of 10 m ² / g or more. Further, the present invention is a method for producing a polyester, characterized in that, when polymerizing the polyester, an average primary particle size is a polyester polymerization catalyst that is an iron oxide having a diameter of 100 nm or less, and the specific surface area is 10 m ² / g or more. A polyester production method characterized by using a polyester polymerization catalyst that is iron oxide. Further, the present invention is a polyester characterized by containing iron oxide having an average primary particle diameter of 100 nm or less, and a polyester characterized by containing iron oxide having a specific surface area of 10 m ² / g or more. .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The polymerization catalyst of the present invention is iron oxide in the form of ultrafine particles. More specifically, it is an ultrafine iron oxide having an average primary particle diameter of 100 nm or less or a specific surface area of 10 m ² / g or more. It is iron. Preferably, it is an iron oxide having an average primary particle diameter of 50 nm or less or a specific surface area of 20 m ² / g or more.

If the average primary particle diameter of iron oxide is 100 nm or more and the specific surface area is 10 m ² / g or less, it does not have sufficient activity as a polymerization catalyst. Average primary particle size of iron oxide is 100n
Even when the specific surface area is 10 m ² / g or more, it has sufficient activity as a polymerization catalyst. Further, the smaller the average primary particle diameter of iron oxide or the larger the specific surface area, the higher the catalytic activity tends to be. Average primary particle size
Iron oxide having a specific surface area of not more than 50 nm or not less than 20 m ² / g is particularly preferred, has sufficient activity as a polymerization catalyst for polyester, and has catalytic activity comparable to that of the same amount of antimony trioxide.

The amount of the ultrafine iron oxide particles in the present invention is 1 to 2000 ppm, preferably 10 to 1000 ppm, based on the obtained polyester. If the amount is less than 1 ppm, sufficient catalytic activity cannot be exhibited, and a long time is required for polymerization. When the addition amount is more than 2000 ppm, the polymerization time is considerably shortened, but the color tone of the polymerized polyester deteriorates and the heat stability also deteriorates. Therefore, this polyester has a disadvantage that it tends to be thermally decomposed during molding and the like.

The production of ultrafine particles of iron oxide used in the present invention can be carried out by the following method. The first method is a method in which iron oxide (particle diameter of several micrometers or more) usually used as a pigment or ferrite is subjected to ultrafine pulverization. Examples of the processing method of ultra-fine pulverization include mechanical milling and application of ultrasonic waves. The second method is to produce iron oxide ultrafine particles by a gas phase method using iron or an iron compound and oxygen as raw materials. Other methods include several methods such as hydrolysis of iron compounds, sol-gel method, electron beam evaporation method, and laser ablation method. Preferred production methods are an ultrafine pulverization treatment and a gas phase method from the viewpoint of low cohesion and purity.

The production of the polyester according to the present invention can be carried out by a conventionally known method. For example, any method of the method of polymerization after esterification of terephthalic acid and ethylene glycol, or the method of polymerization after performing the transesterification reaction of an alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol. It can be carried out. The polymerization apparatus may be of a batch type or a continuous type.

The catalyst of the present invention has catalytic activity not only in a polymerization reaction but also in a transesterification reaction. The transesterification reaction between an alkyl ester of terephthalic acid such as dimethyl terephthalate and ethylene glycol is usually carried out in the presence of a transesterification catalyst such as manganese or zinc, but using the catalyst of the present invention instead of these catalysts Can also.

The time for adding the polymerization catalyst of the present invention is preferably before the start of the polymerization reaction, but it can also be added to the reaction system before the start of the esterification reaction or transesterification reaction and at any stage during the reaction.

The method for adding the polymerization catalyst of the present invention may be in the form of a powder or a slurry of a solvent such as ethylene glycol, and is not particularly limited. The polymerization catalyst of the present invention may be used in the presence of another polymerization catalyst such as an antimony compound.

The polyester referred to in the present invention is one or more selected from polycarboxylic acids containing dicarboxylic acids and their ester-forming derivatives, and one or more selected from polyhydric alcohols containing glycol. Or those composed of hydroxycarboxylic acids and their ester-forming derivatives, or those composed of cyclic esters.

The dicarboxylic acids include oxalic acid, malonic acid,
Succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decane dicarboxylic acid, dodecane dicarboxylic acid, tetradecane dicarboxylic acid, hexadecane dicarboxylic acid, 1,3-cyclobutane dicarboxylic acid, 1,3-cyclo Pentanedicarboxylic acid,
Saturated aliphatic dicarboxylic acids exemplified by 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, dimer acid and the like, and their ester-forming properties Derivatives, unsaturated aliphatic dicarboxylic acids exemplified by fumaric acid, maleic acid, itaconic acid and the like and ester-forming derivatives thereof, orthophthalic acid, isophthalic acid, terephthalic acid, 5- (alkali metal) sulfoisophthalic acid, diphenic acid 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5
-Naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4′-
Biphenyldicarboxylic acid, 4,4′-biphenylsulfonedicarboxylic acid, 4,4′-biphenyletherdicarboxylic acid, 1,2-bis (phenoxy) ethane-p, p ′
-Aromatic dicarboxylic acids exemplified by dicarboxylic acid, pamoic acid, anthracene dicarboxylic acid and the like and ester-forming derivatives thereof are exemplified, and among these dicarboxylic acids, terephthalic acid and isophthalic acid are preferable.

Examples of polycarboxylic acids other than these dicarboxylic acids include ethanetricarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3,4,3 ', 4'-biphenyltetracarboxylic acid. Examples include carboxylic acids and their ester-forming derivatives.

As the glycol, ethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1, 5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,2
-Cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol,
1,4-cyclohexanediethanol, 1,10-decamethylene glycol, 1,12-dodecanediol, polyethylene glycol, polytrimethylene glycol,
Aliphatic glycols exemplified by polytetramethylene glycol, etc., hydroquinone, 4,4′-dihydroxybisphenol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-bis (β-hydroxyethoxyphenyl) sulfone, Bis (p-hydroxyphenyl)
Ether, bis (p-hydroxyphenyl) sulfone,
Bis (p-hydroxyphenyl) methane, 1,2-bis (p-hydroxyphenyl) ethane, bisphenol A
, Bisphenol C, 2,5-naphthalenediol,
Aromatic glycols, such as glycols obtained by adding ethylene oxide to these glycols, are exemplified. Of these glycols, ethylene glycol and 1,4-butylene glycol are preferable.

The polyhydric alcohols other than these glycols include trimethylolmethane, trimethylolethane,
Trimethylolpropane, pentaerythritol, glycerol, hexanetriol and the like.

Examples of hydroxycarboxylic acids include lactic acid, citric acid, malic acid, tartaric acid, hydroxyacetic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid, and 4-hydroxycyclohexanecarboxylic acid. Or ester-forming derivatives thereof.

Examples of the cyclic ester include ε-caprolactone, β-propiolactone, β-methyl-β-pyropiolactone, δ-valerolactone, glycolide, lactide and the like.

The ester-forming derivatives of polycarboxylic acids or hydroxycarboxylic acids include these alkyl esters, acid chlorides and acid anhydrides.

The polyester of the present invention is preferably a polyester whose main repeating unit is an alkylene terephthalate. The polyester in which the main repeating unit is alkylene terephthalate as used herein means that the main acid component is terephthalic acid or an ester-forming derivative thereof,
The main glycol component comprises an alkylene glycol. The alkylene glycol mentioned here may contain a substituent or an alicyclic structure in the molecular chain.

Oxalic acid, malonic acid, succinic acid,
Glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,
Saturated aliphatic dicarboxylic acids exemplified by 5-norbornanedicarboxylic acid, dimer acid or the like or ester-forming derivatives thereof, unsaturated aliphatic dicarboxylic acids exemplified by fumaric acid, maleic acid, itaconic acid or the like or ester formation thereof Derivative, orthophthalic acid, isophthalic acid, 5- (alkali metal) sulfoisophthalic acid, diphenic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6- Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, 4,4′-biphenylsulfonedicarboxylic acid, 4,
Aromatic dicarboxylic acids exemplified by 4'-biphenyl ether dicarboxylic acid, 1,2-bis (phenoxy) ethane-p, p'-dicarboxylic acid, pamoic acid, anthracene dicarboxylic acid and the like, and ester-forming derivatives thereof, ethanetricarboxylic acid Acid, propanetricarboxylic acid,
Copolymerization of polyvalent carboxylic acids exemplified by butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3,4,3 ', 4'-biphenyltetracarboxylic acid and ester-forming derivatives thereof It can be included as a component. Also, lactic acid, citric acid, malic acid,
Including a hydroxycarboxylic acid exemplified by tartaric acid, hydroxyacetic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p- (2-hydroxyethoxy) benzoic acid, 4-hydroxycyclohexanecarboxylic acid, or an ester-forming derivative thereof. Can also. Further, cyclic esters exemplified by ε-caprolactone, β-propiolactone, β-methyl-β-pyropiolactone, δ-valerolactone, glycolide, lactide and the like can also be contained.

As the main alkylene glycol component, 1,2-propylene glycol, 1,3
-Propylene glycol, triethylene glycol,
1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4-butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,2- Cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4
-Cyclohexanediethanol, 1,10-decamethylene glycol, 1,12-dodecanediol and the like. Two or more of these may be used simultaneously. Also, diethylene glycol, polyethylene glycol,
Aliphatic glycols exemplified by polytrimethylene glycol, polytetramethylene glycol, etc., hydroquinone, 4,4′-dihydroxybisphenol, 1,4-
Bis (β-hydroxyethoxy) benzene, 1,4-bis (β-hydroxyethoxyphenyl) sulfone, bis (p-hydroxyphenyl) ether, bis (p-hydroxyphenyl) sulfone, bis (p-hydroxyphenyl) methane, 1,2-bis (p-hydroxyphenyl) ethane, bisphenol A, bisphenol C,
Aromatic glycols exemplified by 2,5 naphthalene diol, glycols obtained by adding ethylene oxide to these glycols, etc., trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, hexanetriol and the like are exemplified. It may contain a polyhydric alcohol or the like.

As the polyester of the present invention, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, poly (1,4-cyclohexanedimethylene terephthalate), polyethylene naphthalate, polybutylene naphthalate, and copolymers thereof are particularly preferable. Of these, polyethylene terephthalate is more preferred.

In the polyester of the present invention, other optional polymers, stabilizers, antioxidants, antistatic agents, dyeing improvers, dyes, pigments, matting agents, optical brighteners and other additives May be contained.

Although the polymerization catalyst used in the present invention is iron oxide, it has a sufficient activity as a polymerization catalyst for polyester. Iron oxide is usually low in activity as a polymerization catalyst for polyester, but it is not clear why iron oxide has a sufficient activity as a polymerization catalyst when it is converted to ultrafine particles, but the surface area of iron oxide increases due to ultrafine particles This is presumed to be due to an increase in active sites.

(Definition of Particle Size and Specific Surface Area) The average primary particle size of the iron oxide referred to in the present invention is a value measured in water using a laser particle size distribution meter (COULTER N4 type manufactured by Nikkaki Co., Ltd.). . The specific surface area of iron oxide was determined by a BET adsorption isotherm after adsorbing nitrogen gas. The particle size and content of iron oxide in the polyester can be measured by TEM.

[0032]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In each of the examples and comparative examples, the intrinsic viscosity (IV) and the reduced viscosity of the polyester were measured as follows. Phenol / 1,1,2,2-tetrachloroethane 6 /
The measurement was performed at a temperature of 30 ° C. using four mixed solvents (weight ratio).
The reduced viscosity was measured at a concentration of 200 mg / 100 ml.

Example 1 Bis (2-hydroxyethyl)
3.8 parts by weight of ethylene glycol slurry of 0.2 wt% concentration of iron oxide ultrafine particles (average primary particle diameter: 20 nm, specific surface area: 50 m ² / g) is added to 100 parts by weight of terephthalate, and the mixture is heated at 245 ° C. for 5 minutes at normal pressure. Stirred. Then take 55 minutes to 275 ℃
The temperature of the reaction system was gradually lowered while raising the temperature to 0.1 mmHg, and a polycondensation reaction was further performed at the same temperature and pressure for 53 minutes. Table 1 shows the physical property values of the obtained polymer.

Example 2 and Comparative Example 1 A polymer was polymerized in the same manner as in Example 1 except that the average primary particle diameter, specific surface area and addition amount of iron oxide and the time of polycondensation were changed. . Table 1 shows the physical property values of the obtained polymer.

Example 3 0.2% by weight based on 100 parts by weight of dimethyl terephthalate and 70 parts by weight of 1,4-butylene glycol
Of 1,4-butylene glycol slurry of iron oxide ultrafine particles (average primary particle diameter: 20 nm, specific surface area: 50 m ² / g)
4.7 parts by weight were added, stirring was started at 150 ° C. under normal pressure, and methanol as a by-product was distilled off while increasing the temperature to 210 ° C. 70 minutes later, the amount of methanol distilled out is 90% of the theoretical value
Crossed. Next, it takes 40 minutes to raise the temperature from 220 ° C to 250 ° C
The pressure in the reaction system was gradually lowered while raising the temperature to 0.1 mmHg, and a polycondensation reaction was further performed at the same temperature and pressure for 60 minutes. Table 2 shows the physical property values of the obtained polymer.

Comparative Example 2 0.2% by weight based on 100 parts by weight of dimethyl terephthalate and 70 parts by weight of 1,4-butylene glycol
Iron oxide (average primary particle size: 2000 nm, specific surface area: <1
49.5 parts by weight of 1,4-butylene glycol slurry (m ² / g), start stirring at 150 ° C under normal pressure, and then increase the temperature to 210 ° C over 70 minutes, while producing by-products The methanol was distilled off. Next, it takes 40 minutes to reach 220 ° C
While gradually increasing the temperature of the reaction system from
The polycondensation reaction was further performed at 0.1 mmHg at the same temperature and pressure for 180 minutes. Table 2 shows the physical property values of the obtained polymer.

Example 4 Ultrafine iron oxide particles having a concentration of 0.2 wt% based on 100 parts by weight of dimethyl 2,6 naphthalenedicarboxylate and 56 parts by weight of ethylene glycol (average primary particle diameter:
19.7 parts by weight of an ethylene glycol slurry of 20 nm, specific surface area: 50 m ² / g) was added, and stirring was started at 150 ° C. under normal pressure.
While increasing the temperature to 220 ° C., methanol as a by-product was distilled off. After 100 minutes, the amount of methanol distilled off exceeded 90% of theory. Then take 40 minutes to raise the temperature from 235 ° C
While raising the temperature to 285 ° C, gradually reduce the pressure of the reaction system to 0.1
The polycondensation reaction was further carried out at the same temperature and pressure for 72 minutes at a pressure of mmHg. Table 3 shows the physical property values of the obtained polymer.

Comparative Example 3 Iron oxide having a concentration of 0.2 wt% based on 100 parts by weight of dimethyl 2,6-naphthalenedicarboxylate and 56 parts by weight of ethylene glycol (average primary particle diameter: 2000 nm, specific surface area: <1 m ² / g) 39.4) Ethylene glycol slurry
Add parts by weight and start stirring at 150 ° C under normal pressure.
By increasing the temperature to 220 ° C. over a period of 00 minutes, methanol as a by-product was distilled off. Then take 40 minutes to raise the temperature
While the temperature was raised from 235 ° C to 285 ° C, the pressure of the reaction system was gradually lowered to 0.1 mmHg, and a polycondensation reaction was further performed at the same temperature and pressure for 180 minutes. Table 3 shows the physical property values of the obtained polymer.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

According to the present invention, there is provided a novel polyester polymerization catalyst having a catalytic activity comparable to that of an antimony compound other than an antimony compound, a method for producing a polyester using the same, and a polyester produced by the method. You. The polyester of the present invention can be applied to fibers for clothing, fibers for industrial materials, various films, sheets, various molded products such as bottles and engineering plastics, and paints and adhesives.

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Claims (6)

[Claims] 1. A polyester polymerization catalyst of iron oxide,
A polyester polymerization catalyst, wherein the average primary particle diameter of iron oxide is 100 nm or less. 2. A polyester polymerization catalyst for iron oxide,
A polyester polymerization catalyst, wherein the specific surface area of iron oxide is 10 m ² / g or more. 3. A method for producing a polyester, comprising using the polyester polymerization catalyst according to claim 1 in the polymerization of the polyester. 4. A method for producing a polyester, comprising using the polyester polymerization catalyst according to claim 2 in the polymerization of the polyester. 5. A polyester comprising iron oxide having an average primary particle diameter of 100 nm or less. 6. A polyester characterized by containing iron oxide having a specific surface area of 10 m ² / g or more.