JP2010209358A - Polycondensation catalyst for producing polyester, and method for producing polyester by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new polycondensation catalyst which has excellent catalytic activity while containing no antimony as a component, and gives a high-molecular weight polyester having an excellent color tone and transparency; and to provide a method for producing the polyester with use of the catalyst. <P>SOLUTION: The catalyst is used for producing the polyester by esterification or transesterification of a dicarboxylic acid or an ester-forming derivative thereof, with a glycol. The catalyst consists of a solid base particle comprising an inner coating layer composed of an oxide of at least one element selected from silicon, aluminum and zirconium, or a composite oxide of at least two elements selected from silicon, aluminum and zirconium in an amount of 1-20 pts.wt., and an outer coating layer composed of titanic acid in an amount of 0.1-50 pts.wt. in terms of TiO<SB>2</SB>on the surface of the particle, based on 100 pts.wt. of the solid base. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a polycondensation catalyst for producing polyester and a method for producing polyester using such a polycondensation catalyst.

  Polyesters typified by polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. have excellent mechanical and chemical properties. Depending on their properties, for example, textiles for clothing and industrial materials, and packaging It is used in a wide range of fields such as films and sheets for magnetic tapes, bottles that are hollow molded products, casings for electrical and electronic components, and other various molded products and components.

  Polyesters mainly comprising an aromatic dicarboxylic acid component and an alkylene glycol component, which are typical polyesters, for example, polyethylene terephthalate is an esterification reaction between terephthalic acid and ethylene glycol, or an ester of dimethyl terephthalate and ethylene glycol. It is produced by producing bis (2-hydroxyethyl) terephthalate (BHET) and an oligomer containing the same by exchange, and subjecting this to melt polycondensation in vacuum in the presence of a polycondensation catalyst at high temperature.

  Conventionally, antimony trioxide has been widely used as such a polycondensation catalyst for producing polyester. Antimony trioxide is an inexpensive catalyst with excellent catalytic activity. However, there are problems that metal antimony precipitates during polycondensation, resulting in darkening of the resulting polyester, and contamination of the resulting polyester. (See Patent Document 1) Originally, there is a problem of toxicity, and in recent years, development of a catalyst containing no antimony has been desired.

  Therefore, for example, a catalyst made of a germanium compound is known as a catalyst that gives polyester having excellent catalytic activity and excellent color tone and thermal stability. However, this catalyst is not only very expensive. However, since it is easy to distill out of the reaction system during the polymerization, there is a problem that the catalyst concentration in the reaction system changes with time, making it difficult to control the polymerization.

  On the other hand, it is already known that titanium compounds such as glycol titanate and titanium alkoxide can also be used as a polycondensation catalyst for polyester production by transesterification of dimethyl terephthalate and ethylene glycol (see, for example, Patent Documents 2 and 3). . For example, although a polycondensation catalyst made of tetraalkoxy titanate is known (see Patent Document 4), there is a problem that the resulting polyester is thermally deteriorated during melt molding and easily colored.

  In recent years, various methods for producing high-quality polyester with high productivity using a titanium compound as a polycondensation catalyst have been proposed. For example, titanium halide or titanium alkoxide is hydrolyzed to obtain titanium hydroxide, which is heated at a temperature of 30 to 350 ° C., dehydrated and dried, and the solid titanium compound thus obtained is polycondensation catalyst. It is proposed to use as (for example, refer to Patent Documents 5 and 6).

  However, some of the polycondensation catalysts made of titanic acid known so far, including the above titanium compounds, have a high polymerization activity per unit weight of metal, but in many cases, the polymerization activity is Although high, the obtained polyester still tends to be colored due to thermal deterioration during melt molding, and tends to be inferior in transparency.

JP 09-291141 A Japanese Patent Publication No.46-3395 JP-A 49-57092 US Pat. No. 5,596,069 JP 2001-064377 A JP 2001-114485 A

  As a result of diligent research to solve the above-described problems in conventional polycondensation catalysts for polyester production, the present inventors have found that an oxide of at least one element selected from silicon, aluminum and zirconium or silicon, aluminum and zirconium An inner coating layer made of a complex oxide of at least two elements selected from the above and an outer coating layer made of titanic acid are formed on the surface of the solid base particles in this order, and this is used as a polycondensation catalyst for polyester production Therefore, decomposition is suppressed during the production of the polyester to give a high molecular weight polyester with a high polymerization activity per unit weight of the metal, and the polyester is hardly colored due to thermal deterioration during melt molding. As a result, the present invention has been achieved.

  Accordingly, the present invention relates to a novel polycondensation catalyst for producing a polyester which does not contain antimony and has excellent catalytic activity, and has excellent color tone and transparency, and polyester using such a polycondensation catalyst. It aims at providing the manufacturing method of.

According to the present invention, there is provided a catalyst for producing a polyester by esterification or transesterification of a dicarboxylic acid or an ester-forming derivative thereof with a glycol, and selected from silicon, aluminum and zirconium with respect to 100 parts by weight of a solid base. 1 to 20 parts by weight of an inner coating layer made of at least one element oxide or a composite oxide of at least two elements selected from silicon, aluminum and zirconium and an outer coating layer made of titanic acid in terms of TiO ₂ A polycondensation catalyst comprising solid base particles having 0.1 to 50 parts by weight on the surface is provided.

Further, according to the present invention, the aqueous slurry of solid base particles is maintained at a temperature of 5 to 100 ° C., and 1 to 20 parts by weight of water soluble in terms of SiO _{2 with} respect to 100 parts by weight of the solid base. Oxidation of at least one element selected from silicon and aluminum on the surface of solid base particles by adding 1 to 20 parts by weight of water-soluble aluminate and acid in terms of silicate and / or Al ₂ O ₃ Or an inner coating layer made of a composite oxide of silicon and aluminum, and then the aqueous slurry of the solid base particles thus obtained has a pH of 5 to 12 at a temperature of 25 to 40 ° C. In this way, an aqueous titanium halide solution and an aqueous alkaline solution are added to form an outer coating layer made of titanic acid on the inner coating layer, and then the solid base particles having the inner and outer coating layers are dried. And the polycondensation catalyst obtained by pulverization is provided.

In addition, while maintaining the aqueous slurry of solid base particles at a temperature of 5 to 100 ° C., 1 to 20 parts by weight of a water-soluble zirconium salt and alkali in terms of ZrO ₂ are added to 100 parts by weight of the solid base. Then, an inner coating layer made of zirconium oxide is formed on the surface of the solid base particles, and then the aqueous slurry of the solid base particles thus obtained has a pH of 5 to 5 at a temperature of 25 to 40 ° C. A titanium halide aqueous solution and an alkaline aqueous solution are added so as to be 12 to form an outer coating layer made of titanic acid on the inner coating layer, and then the solid base particles having the inner and outer coating layers are dried. And the polycondensation catalyst obtained by pulverization is provided.

Furthermore, while maintaining the aqueous slurry of solid base particles at a temperature of 5 to 100 ° C., 1 to 20 parts by weight of a water-soluble silicate in terms of SiO ₂ and / or 100 parts by weight of the solid base. Add 1-20 parts by weight of water-soluble aluminate in terms of Al ₂ O ₃ and 1-20 parts by weight of water-soluble zirconium salt in terms of ZrO ₂ , and select from silicon and aluminum on the surface of the solid base particles. An inner coating layer composed of a composite oxide of at least one element and zirconium, and then the aqueous slurry of the solid base particles thus obtained has a pH of 5 to 5 at a temperature of 25 to 40 ° C. A titanium salt aqueous solution and an alkaline aqueous solution are added so as to form an outer coating layer made of titanic acid on the inner coating layer, and then a solid salt having the inner and outer coating layers The particles were dried, the polycondensation catalyst obtained by pulverizing is provided.

  According to the invention, the solid base is preferably magnesium hydroxide or hydrotalcite.

  Furthermore, according to the present invention, there is provided a method for producing a polyester, characterized in that a dicarboxylic acid or an ester-forming derivative thereof and glycol are subjected to esterification or transesterification in the presence of the polycondensation catalyst.

  In particular, according to the present invention, as a preferred embodiment, an oligomer containing the aromatic dicarboxylic acid bis (hydroxylalkyl) ester by an esterification reaction or transesterification reaction between an aromatic dicarboxylic acid or an ester-forming derivative thereof and an alkylene glycol. And then a method for producing a polyester, characterized in that the oligomer is melt polycondensed at high temperature under high vacuum in the presence of the polycondensation catalyst.

  In the polyester production by esterification reaction or transesterification reaction of dicarboxylic acid or its ester-forming derivative and glycol, by using the polycondensation catalyst for polyester production according to the present invention, the polyester is darkened or incorporated into the polyester during the production of the polyester. Thus, it is possible to obtain a high molecular weight polyester having excellent color tone and transparency with high polymerization activity without mixing of foreign substances and without decomposing the polyester.

The polycondensation catalyst for polyester production according to the present invention is a catalyst for polyester production by esterification reaction or transesterification reaction between a dicarboxylic acid or an ester-forming derivative thereof and a glycol, with respect to 100 parts by weight of a solid base, An outer coating comprising 1 to 20 parts by weight of an inner coating layer composed of an oxide of at least one element selected from aluminum and zirconium or a composite oxide of at least two elements selected from silicon, aluminum and zirconium, and titanic acid The layer is made of solid base particles having 0.1 to 50 parts by weight on the surface in terms of TiO ₂ .

  In the present invention, as the solid base, for example, oxides or hydroxides of alkali metals or alkaline earth metals, various composite oxides, oxides of aluminum, zinc, lanthanum, zirconium, thorium, etc. Can be mentioned. These oxides and composites may be partially substituted with salts such as carbonates. Therefore, in the present invention, as the solid base, more specifically, oxides or hydroxides of magnesium, calcium, strontium, barium, aluminum, zinc, etc., for example, magnesium hydroxide, calcium oxide, strontium oxide, barium oxide Examples thereof include zinc oxide and complex oxides such as hydrotalcite. Among these, according to the present invention, magnesium hydroxide or hydrotalcite is preferably used.

In the present invention, titanic acid is a general formula
TiO ₂ · nH ₂ O
(In the formula, n is a number satisfying 0 <n ≦ 2.)
The hydrous titanium oxide represented by the formula, and such titanic acid can be obtained, for example, by alkaline hydrolysis of a certain kind of titanium compound as described later.

  In the polycondensation catalyst according to the present invention, an oxide of at least one element selected from silicon, aluminum and zirconium or a composite oxidation of at least two elements selected from silicon, aluminum and zirconium with respect to 100 parts by weight of a solid base When the ratio of the inner coating layer made of the product is less than 1 part by weight, the polymerization activity of the resulting polycondensation catalyst is high, but no improvement in the color tone of the obtained polyester is observed, while the solid base is 100 parts by weight. On the other hand, when the ratio of the inner coating layer is more than 20 parts by weight in terms of oxide, it is not preferable because the polymerization activity of the resulting polycondensation catalyst is lowered.

On the other hand, when the proportion of the outer coating layer made of titanic acid is less than 0.1 parts by weight in terms of TiO _{2 with} respect to 100 parts by weight of the solid base, the polymerization activity of the resulting polycondensation catalyst is low, and the high molecular weight When the polyester cannot be obtained with good productivity and the ratio of the coating layer made of titanic acid is more than 50 parts by weight in terms of TiO _{2 with} respect to 100 parts by weight of the solid base, Is easily decomposed, and coloring due to thermal degradation is likely to occur during melt molding of the obtained polyester.

In the polycondensation catalyst according to the present invention, an inner coating layer made of an oxide of at least one element selected from silicon and aluminum or a composite oxide of silicon and aluminum is formed on the surface of the solid base particles, and on the inner coating layer The polycondensation catalyst having an outer coating layer made of titanic acid maintains an aqueous slurry of solid base particles at a temperature of 5 to 100 ° C., preferably 30 to 60 ° C., with respect to 100 parts by weight of the solid base. 1 to 20 parts by weight of water-soluble silicate in terms of SiO ₂ and / or 1 to 20 parts by weight of water-soluble aluminate in terms of Al ₂ O ₃ are added, and an acid is added to the slurry. Is neutralized at pH 7-12, preferably 8-9, washed with water, and oxides of at least one element selected from silicon and aluminum or silicon and aluminum on the surface of the solid base particles. Forming an inner coating layer composed of a complex oxide of um, and then maintaining the aqueous slurry of the solid base particles thus obtained at a temperature of 5 to 100 ° C., preferably 25 to 40 ° C., To this, 0.1 to 50 parts by weight of a titanium compound in terms of TiO ₂ is added to 100 parts by weight of the solid base, an alkali is added to the resulting mixture, and the slurry is pH 5 to 12, preferably 7 to 10 to form an outer coating layer made of titanic acid on the inner coating layer, and then drying and pulverizing the solid base particles having such inner coating layer and outer coating layer. Can be obtained.

Also, the polycondensation catalyst having an inner coating layer made of zirconium oxide on the surface of the solid base particles and an outer coating layer made of titanic acid on the inner coating layer, While maintaining the slurry at a temperature of 5 to 100 ° C., preferably 30 to 60 ° C., 1 to 20 parts by weight of a water-soluble zirconium salt and an alkali in terms of ZrO ₂ are added to 100 parts by weight of the solid base. The slurry is neutralized at a pH of 7 to 12, preferably 8 to 9, and washed with water to form an inner coating layer made of zirconium oxide on the surface of the solid base particles. The obtained aqueous slurry of solid base particles is treated in the same manner as described above to form an outer coating layer made of titanic acid on the inner coating layer, dried and pulverized.

Furthermore, a polycondensation catalyst having an inner coating layer made of a complex oxide of at least one element selected from silicon and aluminum and zirconium on the surface of the solid base particles, and an outer coating layer made of titanic acid on the inner coating layer In the same manner as described above, while maintaining an aqueous slurry of solid base particles at a temperature of 5 to 100 ° C., preferably 30 to 60 ° C., it is converted to SiO _{2 with} respect to 100 parts by weight of the solid base. Add 1-20 parts by weight of water-soluble silicate and / or 1-20 parts by weight of water-soluble aluminate in terms of Al ₂ O ₃ and 1-20 parts by weight of water-soluble zirconium salt in terms of ZrO ₂ The slurry is neutralized at pH 7-12, preferably 8-9, washed with water, and the surface of the solid base particles is a composite of at least one element selected from silicon and aluminum and zirconium. Then, an aqueous slurry of the solid base particles thus obtained is treated in the same manner as described above to form an outer coating layer made of titanic acid on the inner coating layer. , Dried and pulverized.

  In the preparation of the polycondensation catalyst according to the present invention described above, the temperature at which the outer coating layer made of titanic acid is formed on the inner coating layer and then dried is preferably in the range of 60 to 180 ° C., particularly preferably. Is in the range of 100-130 ° C.

The polycondensation catalyst according to the present invention can also be obtained by another method. That is, the surface of the solid base particle is composed of an oxide of at least one element selected from silicon, aluminum and zirconium or a composite oxide of at least two elements selected from silicon, aluminum and zirconium as described above. After forming the inner coating layer, the aqueous slurry of such solid base particles is maintained at 5 to 100 ° C., preferably 25 to 40 ° C., while TiO ₂ is added to 100 parts by weight of the solid base. In terms of conversion, 0.1 to 50 parts by weight of the titanium compound and the alkali are added at an approximately equivalent ratio, and if necessary, an alkali is further added to adjust the pH to 5 to 12, preferably 7 to 10. By hydrolyzing, an outer coating layer made of titanic acid is formed on the inner coating, and this is dried at a temperature of 60 to 180 ° C. and pulverized. It is possible to obtain.

  Examples of the water-soluble silicate for forming the inner coating layer include sodium silicate and potassium silicate. Examples of the water-soluble aluminate include sodium aluminate and potassium aluminate. Examples of the water-soluble zirconium salt include zirconium oxychloride and zirconium trichloride, but are not limited to these examples.

  Examples of the titanium compound for forming a titanic acid coating as the outer coating layer include titanium halides such as titanium tetrachloride, titanates such as titanyl ammonium oxalate, tetraisopropoxide, etc. However, it is not limited to these examples.

  Examples of the alkali used for the hydrolysis include ammonia and sodium hydroxide, but the alkali is not limited to the above examples.

A preferred first polycondensation catalyst according to the invention is one in which the solid base is magnesium hydroxide. That is, the preferred first polycondensation catalyst according to the present invention is an oxide of at least one element selected from silicon, aluminum and zirconium or at least selected from silicon, aluminum and zirconium with respect to 100 parts by weight of magnesium hydroxide. Magnesium hydroxide having 1 to 20 parts by weight of an inner coating layer made of a composite oxide of two elements and 0.1 to 50 parts by weight of an outer coating layer made of titanic acid on the surface in terms of TiO ₂ in this order. Consists of particles.

  The aqueous slurry of magnesium hydroxide particles used in the preparation of such a first polycondensation catalyst is, for example, an aqueous solution of a water-soluble magnesium salt such as magnesium chloride or magnesium nitrate or an alkali such as sodium hydroxide or ammonia. An aqueous slurry obtained by neutralizing with and precipitating magnesium hydroxide, or a slurry obtained by dispersing magnesium hydroxide particles in an aqueous medium. When neutralizing such an aqueous solution of a water-soluble magnesium salt with an alkali to obtain an aqueous slurry of magnesium hydroxide, the aqueous solution of the water-soluble magnesium salt and the alkali may be simultaneously neutralized. You may neutralize in addition to the other.

  In the present invention, the aqueous slurry means an aqueous solution in which the slurry dispersion medium contains water or a small amount of a water-soluble organic solvent. Similarly, the aqueous solution means that the solvent of the solution is water or a small amount of a water-soluble organic solvent. An aqueous medium refers to an aqueous solution containing water or a small amount of a water-soluble organic solvent.

  Further, the origin of the magnesium hydroxide particles is not limited, and for example, powder obtained by pulverizing natural ore, powder obtained by neutralizing magnesium salt aqueous solution with alkali, etc. There may be.

Preferred second polycondensation catalysts according to the invention are those in which the solid base is hydrotalcite. That is, the preferred second polycondensation catalyst according to the present invention is an oxide of at least one element selected from silicon, aluminum and zirconium or at least selected from silicon, aluminum and zirconium with respect to 100 parts by weight of hydrotalcite. Hydrotalcite having 1 to 20 parts by weight of an inner coating layer made of a composite oxide of two elements and 0.1 to 50 parts by weight of an outer coating layer made of titanic acid on the surface in terms of TiO ₂ in this order. Consists of particles.

In the present invention, the hydrotalcite is preferably the following general formula (I):
^{_{M 2+ 1-x M 3+ x}} (OH -) 2 A n- x / n · mH 2 O ... (I)
( ^Wherein M ²⁺ represents at least one divalent metal ion selected from Mg ²⁺ , Zn ²⁺ and Cu ²⁺ , and M ³⁺ is selected from Al ³⁺ , Fe ³⁺ and Ti ^3+. at least one a trivalent metal ion, a ^n-is SO ₄ ^2-, Cl is ^-, CO ₃ ^2-and OH ^- represents at least one anion selected from, n represents the valence of the anion X is a number satisfying 0 <x <0.5, and m is a number satisfying 0 ≦ m <2.)
It is represented by

Particularly, in the present invention, M ²⁺ is the Mg ^2+, M ³⁺ is the Al ^3+, hydrotalcite A ^n- is CO ₃ is ^2, i.e., the general formula (II)
Mg ²⁺ _1-x Al ³⁺ _x (OH ⁻ ) ₂ (CO ₃ ²⁻ ) _{x / 2} · mH ₂ O (II)
(Wherein x and m are the same as above)
What is represented by these is used preferably. Such hydrotalcite can be easily obtained as a commercial product, but if necessary, it can also be produced by a conventionally known method, for example, a hydrothermal method, using appropriate raw materials. .

  The aqueous slurry of hydrotalcite used in the preparation of such a second polycondensation catalyst refers to a slurry obtained by dispersing the aforementioned hydrotalcite in the aforementioned aqueous medium.

  The method for producing a polyester according to the present invention comprises subjecting a dicarboxylic acid or an ester-forming derivative thereof and a glycol to an esterification reaction or an ester exchange reaction in the presence of the polycondensation catalyst. In the present invention, examples of the dicarboxylic acid include aliphatic dicarboxylic acids exemplified by succinic acid, glutaric acid, adipic acid, dodecanedicarboxylic acid and the like, and ester-forming derivatives thereof such as dialkyl esters, terephthalic acid, isophthalic acid, naphthalene. Aromatic dicarboxylic acids exemplified by dicarboxylic acids and the like and ester-forming derivatives thereof, for example, dialkyl esters can be mentioned. In the present invention, examples of the glycol include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 1,4-cyclohexanedimethanol and the like.

  Among the above, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid are preferably used as the dicarboxylic acid, and alkylene glycols such as ethylene glycol, propylene glycol and butylene glycol are used as the glycol. Is preferably used.

  Accordingly, in the present invention, preferred specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polypropylene naphthalate, poly (1,4-cyclohexanedimethylene terephthalate) and the like. be able to.

  However, the dicarboxylic acid or ester-forming derivative thereof, glycol or ester-forming derivative thereof that can be used in the present invention is not limited to the above examples, and the polyester obtained is also limited to the above examples. Is not to be done.

  In general, a polyester represented by polyethylene terephthalate is produced by one of the following methods. That is, a low molecular weight oligomer containing BHET is obtained by a direct esterification reaction between a dicarboxylic acid typified by terephthalic acid and a glycol typified by ethylene glycol, and this oligomer is further increased in the presence of a polycondensation catalyst. Similarly, a method of obtaining a polyester having a required molecular weight by melt polycondensation under vacuum or high temperature, or a transesterification reaction between a dialkyl ester of terephthalic acid represented by dimethyl terephthalate and a glycol represented by ethylene glycol. In this method, a low molecular weight oligomer containing BHET is obtained, and this oligomer is melt polycondensed in the presence of a polycondensation catalyst in a high vacuum and at a high temperature to obtain a polyester having a required molecular weight.

  Also in the present invention, the low molecular weight oligomer containing BHET is obtained by the direct esterification reaction or transesterification reaction described above, as is conventionally known except that the first or second polycondensation catalyst described above is used. Then, the oligomer having the required molecular weight can be obtained by subjecting the oligomer to melt polycondensation in the presence of the polycondensation catalyst under high vacuum and high temperature.

  The production of polyethylene terephthalate will be described as an example. According to a conventional method, as is known, dimethyl terephthalate and ethylene glycol are charged into a reaction vessel together with a catalyst, for example, calcium acetate, heated under normal pressure, and reflux of ethylene glycol. A low molecular weight oligomer containing BHET can be obtained by reacting while distilling methanol out of the reaction system at a temperature. The degree of polymerization of the oligomer is usually up to about 10. If necessary, the reaction may be performed under pressure. The reaction can be followed by the amount of methanol distilled, and the esterification rate is usually about 95%.

  In the case of direct esterification reaction, terephthalic acid and ethylene glycol are charged into a reaction vessel, and if necessary, heated under pressure while distilling off generated water, similarly, low molecular weight containing BHET. Can be obtained. In the case of such direct esterification reaction, it is preferable to add the low molecular weight oligomer containing BHET produced together with the raw material to the reaction vessel in advance and perform the direct esterification reaction in the presence of the low molecular weight oligomer.

  Subsequently, the low molecular weight oligomer thus obtained is transferred to a polymerization tank, heated to a temperature higher than the melting point of polyethylene terephthalate (usually 240 to 280 ° C.) under reduced pressure, and unreacted ethylene. While the ethylene glycol produced by the reaction with glycol is distilled out of the reaction system, the oligomer is melt polycondensed while monitoring the viscosity of the molten reactant. This polycondensation reaction may be performed using a plurality of reaction vessels as necessary, while optimally changing the reaction temperature and pressure in each reaction vessel. When the viscosity of the reaction mixture reaches the required value, the decompression is stopped, for example, the inside of the polymerization tank is returned to normal pressure with nitrogen gas, and the obtained polyester is discharged from the reaction tank, for example, in the form of a strand and cooled with water. Cut into pellets. According to the present invention, a polyester having an intrinsic viscosity [η] of 0.4 to 1.0 dL / g can be usually obtained in this manner.

  The polycondensation catalyst for polyester production according to the present invention may be added to the reaction system during direct esterification reaction or transesterification reaction for the production of the oligomer containing BHET, and after obtaining a low molecular weight oligomer, May be added to the reaction system when further polycondensation. In addition, the polycondensation catalyst according to the present invention may be added to the reaction system as it is in the form of a powder, or may be dispersed in glycol used as a raw material and added to the reaction system. However, since the polycondensation catalyst according to the present invention can be easily dispersed in glycol, particularly ethylene glycol, the reaction is preferably performed during direct esterification or transesterification for the production of the oligomer containing BHET. Used in addition to the system.

The polycondensation catalyst according to the present invention is usually used in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ mol part with respect to 100 mol part of the dicarboxylic acid or ester-forming derivative thereof used. When the proportion of the polycondensation catalyst according to the present invention is less than 1 × 10 ⁻⁵ mol parts relative to 100 mol parts of the dicarboxylic acid or ester-forming derivative thereof used, the catalytic activity is not sufficient and the intended high molecular weight On the other hand, when it is more than 1 × 10 ⁻¹ mol part, the obtained polyester may be inferior in thermal stability.

  Any of the polycondensation catalysts according to the present invention has catalytic activity not only in melt polymerization but also in solid phase polymerization or solution polymerization, and in any case, it can be used for production of polyester.

  Since the polycondensation catalyst according to the present invention does not contain antimony as a component, the resulting polyester is not darkened or mixed as a foreign substance in the obtained polyester, and is equivalent to a catalyst containing antimony as a component or A polyester having a catalytic activity higher than that and having excellent color and transparency can be obtained. Moreover, the polycondensation catalyst according to the present invention is non-toxic and safe.

  In the production of polyester by esterification or transesterification of dicarboxylic acid or its ester-forming derivative and glycol, the acid catalysis of titanic acid is coordinated as a Lewis acid to the carbonyl group of dicarboxylic acid or its ester-forming derivative. Thus, it is presumed that the attack of the glycol on the carbonyl carbon is facilitated, and at the same time, the dissociation of the glycol is promoted to increase its nucleophilicity. However, when this acid catalysis is too strong, an undesirable side reaction may occur, leading to a polyester degradation reaction or coloring. Here, according to the polycondensation catalyst according to the present invention, the inner side comprising an oxide of at least one element selected from silicon, aluminum and zirconium or a composite oxide of at least two elements selected from silicon, aluminum and zirconium By forming an outer coating layer comprising a coating layer and titanic acid on the surface of the solid base particles, excessive base catalysis of the solid base can be suppressed, and the titanic acid catalyst of the outer coating layer can be suppressed. As a result of the more moderate action, it is expected to give a higher molecular weight polyester having better color and transparency.

  However, according to the present invention, conventionally known polycondensation catalysts, such as antimony, germanium, titanium, tin, aluminum, etc., are used in the production of polyesters, as long as the advantages of using the polycondensation catalyst of the present invention are not impaired. You may use together the polycondensation catalyst which consists of these compounds. Further, if necessary, an alkali metal compound and a phosphoric acid compound may be used in combination for improving thermal stability.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the following examples, in the obtained polycondensation catalyst, the parts by weight of silicon oxide, aluminum oxide and zirconium oxide with respect to 100 parts by weight of the solid base are respectively converted to SiO ₂ , Al ₂ O ₃ and ZrO _2. In the case of a complex oxide, when the elements contained therein are silicon, aluminum and zirconium, they are calculated as SiO ₂ , Al ₂ O ₃ and ZrO ₂ , respectively.

  Further, in the following examples and comparative examples, the intrinsic viscosity of the obtained polyester was measured by ISO1628-1, and the color tone was determined by a 45 ° diffusion method color difference meter (SC2-CH type manufactured by Suga Test Instruments Co., Ltd.). And measured. Further, the haze value of the obtained polyester is measured for each plate having a thickness of 5 mm according to JIS K-7136 by melting the polyester at 280 ° C. to form a stepped square plate.

Reference example 1
(Preparation of water slurry of magnesium hydroxide)
5 L of water was charged into the reactor, and 16.7 L of a 4 mol / L magnesium chloride aqueous solution and 8.4 L of a 14.3 mol / L sodium hydroxide aqueous solution were simultaneously added to the reactor while stirring. The hydrothermal reaction was performed for 5 hours. The magnesium hydroxide thus obtained was filtered and washed with water, and the resulting cake was resuspended in water to obtain an aqueous magnesium hydroxide slurry (123 g / L).

Reference example 2
(Preparation of hydrotalcite water slurry)
A mixed solution of 2.6 L of a 3.8 mol / L aqueous magnesium sulfate solution and 2.6 L of a 0.85 mol / L aqueous aluminum sulfate solution, and 2.8 L of a 9.3 mol / L aqueous sodium hydroxide solution A mixed solution of 2.64 mol / L sodium carbonate aqueous solution with a concentration of 2.54 mol / L was simultaneously added to the reactor with stirring, and then hydrothermal reaction was performed at 180 ° C. for 2 hours. After completion of the reaction, the obtained slurry was filtered, washed, dried and pulverized to obtain hydrotalcite having a composition of Mg _0.7 Al _0.3 (OH) ₂ (CO ₃ ) _0.15 · 0.48H ₂ O. . This hydrotalcite was suspended in water to obtain a hydrotalcite water slurry (100 g / L).

Example 1
(Preparation of polycondensation catalyst A)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 290.9%) 190.9 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the magnesium hydroxide slurry having the inner coating layer, 0.016 L of a titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 0.016 L in a sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped at the same time over 0.02 hours so that the pH might be 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst A according to the present invention having 5 parts by weight of a coating layer and 0.1 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester a)
In a glass reaction vessel equipped with a side tube, 13.6 g (0.070 mol) of dimethyl terephthalate, 10.0 g (0.16 mol) of ethylene glycol, 0.022 g of calcium acetate dihydrate and polycondensation catalyst A0. 0013 g (2.1 × 10 ⁻⁵ mol, 0.03 mol part with respect to 100 mol parts of dimethyl terephthalate) was charged, and a part of this reaction vessel was placed in an oil bath at a temperature of 197 ° C. Dissolved in glycol. A capillary is inserted into the reaction tube so that it reaches the bottom of the reaction vessel. Using this capillary, nitrogen is blown into the reaction vessel for 1 hour, and most of the produced methanol is distilled for 2 hours. Then, an oligomer containing BHET was obtained.

  Subsequently, when heated at 222 ° C. for 15 minutes, ethylene glycol was distilled off and polycondensation started. Thereafter, when the temperature was raised to 283 ° C. and kept at this temperature, ethylene glycol further distilled and polycondensation proceeded. After 10 minutes, pressure reduction was started, and the pressure was reduced to 27 Pa or less over 15 minutes. Thereafter, polycondensation was completed in 3 hours. After completion of the polycondensation reaction, the inside of the reaction vessel is returned to normal pressure with nitrogen gas, and the obtained polyester is discharged in a strand form from the outlet at the bottom of the reaction vessel, cooled and cut to obtain polyester pellets. It was. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 2
(Production of polyester b)
43 g (0.26 mol) of terephthalic acid and 19 g (0.31 mol) of ethylene glycol were charged into a reaction vessel and stirred in a nitrogen gas atmosphere to obtain a slurry. The esterification reaction was carried out over 4 hours while maintaining the temperature of this reaction vessel at 250 ° C. and the relative pressure to atmospheric pressure at 1.2 × 10 ⁵ Pa. 50 g of the low molecular weight oligomer thus obtained was transferred to a polycondensation reaction tank maintained at a temperature of 250 ° C. and normal pressure in a nitrogen gas atmosphere.

0.0024 g of polycondensation catalyst A (3.9 × 10 ⁻⁵ mol, 0.015 mol part with respect to 100 mol part of terephthalic acid component subjected to polycondensation) was previously dispersed in ethylene glycol to form a slurry. Added to the polycondensation reactor. Thereafter, the temperature in the reaction vessel was raised from 250 ° C. to 280 ° C. over 3 hours, and this temperature was maintained, and at the same time, the pressure was reduced from normal pressure to absolute pressure 40 Pa over 1 hour. Further, heating was continued for 2 hours to carry out a polycondensation reaction. After completion of the polycondensation reaction, the inside of the reaction vessel is returned to normal pressure with nitrogen gas, and the obtained polyester is discharged in a strand form from the outlet at the bottom of the reaction vessel, cooled and cut to obtain polyester pellets. It was. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 3
(Preparation of polycondensation catalyst B)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 291.8%) 381.8 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the magnesium hydroxide slurry having the inner coating layer, 0.016 L of a titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 0.016 L in a sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped at the same time over 0.02 hours so that the pH might be 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst B according to the present invention having 10 parts by weight of a coating layer and 0.1 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester c)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst B was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 4
(Production of polyester d)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst B was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 5
(Preparation of polycondensation catalyst C)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 290.9%) 190.9 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the magnesium hydroxide slurry having the inner coating layer, 0.16 L of a titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 0.16 L of a sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped at the same time over 0.2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst C according to the present invention having 5 parts by weight of a coating layer and 1 part by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester e)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst C was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 6
(Production of polyester f)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst C was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 7
(Preparation of polycondensation catalyst D)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 291.8%) 381.8 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the magnesium hydroxide slurry having the inner coating layer, 0.16 L of a titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 0.16 L of a sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped at the same time over 0.2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst D according to the present invention having 10 parts by weight of a coating layer and 1 part by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester g)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst D was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 8
(Manufacture of polyester h)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst D was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 9
(Preparation of polycondensation catalyst E)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 29 weight%) 38.2 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst E according to the present invention having 1 part by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester i)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst E was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 10
(Manufacture of polyester j)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst E was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 11
(Preparation of polycondensation catalyst F)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 290.9%) 190.9 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst F according to the present invention having 5 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester k)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst F was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 12
(Manufacture of polyester l)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst F was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 13
(Preparation of polycondensation catalyst G)
After charging 9.0 L of the magnesium hydroxide water slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 291.8%) 381.8 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst G according to the present invention having 10 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester m)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst G was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 14
(Manufacture of polyester n)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst G was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 15
(Preparation of polycondensation catalyst H)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 293.6% by weight) was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst H according to the present invention having 20 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester o)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst H was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 16
(Manufacture of polyester p)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst H was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 17
(Preparation of polycondensation catalyst I)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 290.9%) 190.9 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. The slurry of magnesium hydroxide having the inner coating layer was charged with 3.2 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 3.2 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH). It was dripped simultaneously over 4 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst I according to the present invention having 5 parts by weight of a coating layer and 20 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester q)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst I was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 18
(Production of polyester r)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst I was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 19
(Preparation of polycondensation catalyst J)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 290.9%) 190.9 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of silicon oxides on the surface of magnesium hydroxide particle. To the magnesium hydroxide slurry having the inner coating layer, 8.0 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 8.0 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 10 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst J according to the present invention having 5 parts by weight of a coating layer and 50 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester s)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst J was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 20
(Manufacture of polyester t)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst J was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 21
(Preparation of polycondensation catalyst K)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the sodium aluminate aqueous solution (Al ₂ O) was heated and maintained at 60 ° C. ₃ ) (19% by weight) 495.3 g. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner side coating layer which consists of aluminum oxides on the surface of magnesium hydroxide particle. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of aluminum oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst K according to the present invention having 5 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester u)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst K was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 22
(Preparation of polycondensation catalyst L)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining the zirconium oxychloride aqueous solution (as ZrO _2). 106.7%) was added. Further, sodium hydroxide was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of zirconium oxides on the surface of magnesium hydroxide particle. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of zirconium oxide with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst L according to the present invention having 5 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester v)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst L was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 23
(Preparation of polycondensation catalyst M)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 295.5%) and 95.5 g of sodium aluminate aqueous solution (19% by weight as Al ₂ O ₃ ) 247.6 g. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner coating layer which consists of a complex oxide of silicon and aluminum on the surface of magnesium hydroxide particles. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and composite oxidation of silicon and aluminum with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst M according to the present invention having 5 parts by weight of an inner coating layer made of a product and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester w)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst M was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 24
(Preparation of polycondensation catalyst N)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). (29 wt%) 95.5 g and zirconium oxychloride aqueous solution (10 wt% as ZrO ₂ ) 568.4 g were added, followed by aging at pH 8.5 for 1 hour. Thereafter, filtration and washing were carried out to form an inner coating layer made of a composite oxide of silicon and zirconium on the surface of the magnesium hydroxide particles. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and composite oxidation of silicon and zirconium with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst N according to the present invention having 5 parts by weight of an inner coating layer made of a product and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester x)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst N was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 25
(Preparation of polycondensation catalyst O)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the sodium aluminate aqueous solution (Al ₂ O) was heated and maintained at 60 ° C. ₃ ) (19% by weight) 247.6 g and zirconium oxychloride aqueous solution (10% by weight as ZrO ₂ ) 568.4 g were added, followed by aging at pH 8.5 for 1 hour. Then, it filtered and washed with water, and formed the inner side coating layer which consists of aluminum and a zirconium complex oxide on the surface of a magnesium hydroxide particle. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and composite oxidation of aluminum and zirconium with respect to 100 parts by weight of magnesium hydroxide. A polycondensation catalyst O according to the present invention having 5 parts by weight of an inner coating layer made of a product and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester y)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst O was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 26
(Preparation of polycondensation catalyst P)
After charging 9.0 L of the magnesium hydroxide aqueous slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the temperature was raised to 60 ° C. and maintained while maintaining an aqueous sodium silicate solution (as SiO _2). 29 weight percent) 63.6 g, sodium aluminate aqueous solution (19 weight percent as Al ₂ O ₃ ) 165.1 g, and zirconium oxychloride aqueous solution (10 weight percent as ZrO ₂ ) 378.9 g were added at pH 8.5 for 1 hour. Aged. Thereafter, filtration and washing were carried out to form an inner coating layer made of a composite oxide of silicon, aluminum and zirconium on the surface of the magnesium hydroxide particles. To the slurry of magnesium hydroxide having the inner coating layer, 1.6 L of titanium tetrachloride aqueous solution (69.2 g / L in terms of TiO ₂ ) and 1.6 L of sodium hydroxide aqueous solution (99.6 g / L in terms of NaOH) were added. It was dripped simultaneously over 2 hours so that the pH might be set to 10.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The aqueous slurry of magnesium hydroxide particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried and then pulverized, and 100 parts by weight of magnesium hydroxide contains silicon, aluminum and zirconium. A polycondensation catalyst P according to the present invention having 5 parts by weight of an inner coating layer made of a complex oxide and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester z)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst P was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 27
(Preparation of polycondensation catalyst Q)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was kept at 60 ° C. while maintaining and maintaining the aqueous solution of sodium silicate (29 as SiO 2). (Weight%) 86.2 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner side coating layer which consists of silicon oxides on the surface of a hydrotalcite particle. To this hydrotalcite slurry having the inner coating layer, 0.07 L of titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.07 L of aqueous sodium hydroxide solution (100 g / L in terms of NaOH) were added to its pH. Was simultaneously added dropwise over a period of 0.2 hours so that the ratio was 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of hydrotalcite particles having inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of hydrotalcite A polycondensation catalyst Q according to the present invention having 5 parts by weight of a coating layer and 1 part by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester aa)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst Q was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 28
(Manufacture of polyester ab)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst Q was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 29
(Preparation of polycondensation catalyst R)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining and maintaining the sodium silicate aqueous solution (as SiO _2). 292.4%) 172.4 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner side coating layer which consists of silicon oxides on the surface of a hydrotalcite particle. To this hydrotalcite slurry having the inner coating layer, 0.07 L of titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.07 L of aqueous sodium hydroxide solution (100 g / L in terms of NaOH) were added to its pH. Was simultaneously added dropwise over a period of 0.2 hours so that the ratio was 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of hydrotalcite particles having inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of hydrotalcite A polycondensation catalyst R according to the present invention having 10 parts by weight of a coating layer and 1 part by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester ac)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst R was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 30
(Manufacture of polyester ad)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst R was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 31
(Preparation of polycondensation catalyst S)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining and maintaining the sodium silicate aqueous solution (as SiO _2). 29 wt%) 17.2 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner side coating layer which consists of silicon oxides on the surface of a hydrotalcite particle. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of hydrotalcite particles having inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of hydrotalcite A polycondensation catalyst S according to the present invention having 1 part by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester ae)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst S was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 32
(Manufacture of polyester af)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst S was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 33
(Preparation of polycondensation catalyst T)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining and maintaining the sodium silicate aqueous solution (as SiO _2). 29 wt%) 86.2 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner side coating layer which consists of silicon oxides on the surface of a hydrotalcite particle. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the surface of the hydrotalcite having the inner coating layer.

  The water slurry of hydrotalcite particles having inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of hydrotalcite A polycondensation catalyst T according to the present invention having 5 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester ag)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst T was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 34
(Manufacture of polyester ah)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst T was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 35
(Preparation of polycondensation catalyst U)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining and maintaining the sodium silicate aqueous solution (as SiO _2). 292.4%) 172.4 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner side coating layer which consists of silicon oxides on the surface of a hydrotalcite particle. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of hydrotalcite particles having inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of hydrotalcite A polycondensation catalyst U according to the present invention having 10 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester ai)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst U was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 36
(Manufacture of polyester aj)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst U was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 37
(Preparation of polycondensation catalyst V)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining and maintaining the sodium silicate aqueous solution (as SiO _2). 29 wt%) 86.2 g was added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Then, it filtered and washed with water, and formed the inner side coating layer which consists of silicon oxides on the surface of a hydrotalcite particle. To this hydrotalcite slurry having the inner coating layer, 3.5 L of titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 3.5 L of sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over a period of 10 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of hydrotalcite particles having inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of silicon oxide with respect to 100 parts by weight of hydrotalcite A polycondensation catalyst V according to the present invention having 5 parts by weight of a coating layer and 50 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester ak)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst V was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 38
(Manufacture of polyester al)
A polyester was obtained in the same manner as in Example 2 except that the polycondensation catalyst V was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 39
(Preparation of polycondensation catalyst W)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the sodium aluminate aqueous solution (Al ₂ O) was heated and maintained at 60 ° C. ₃ ) (19% by weight) 223.7 g. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Thereafter, filtration and washing were performed to form an inner coating layer made of aluminum oxide on the surface of the hydrotalcite particles. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of the hydrotalcite particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of aluminum oxide with respect to 100 parts by weight of hydrotalcite. A polycondensation catalyst W according to the present invention having 5 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester am)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst W was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 40
(Preparation of polycondensation catalyst X)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining the temperature as 60 ° C., as an aqueous zirconium oxychloride solution (ZrO _2). 103.3%) was added. Further, sodium hydroxide was added until the pH reached 8.5, and aging was performed for 1 hour. Thereafter, filtration and washing were performed to form an inner coating layer made of zirconium oxide on the surface of the hydrotalcite particles. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of the hydrotalcite particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and the inner side made of zirconium oxide with respect to 100 parts by weight of hydrotalcite. A polycondensation catalyst X according to the present invention having 5 parts by weight of a coating layer and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester an)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst X was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 41
(Preparation of polycondensation catalyst Y)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining and maintaining the sodium silicate aqueous solution (as SiO _2). 29 wt%) 43.1 g and sodium aluminate aqueous solution (19 wt% as Al ₂ O ₃ ) 111.8 g were added. Further, sulfuric acid was added until the pH reached 8.5, and aging was performed for 1 hour. Thereafter, filtration and washing were performed to form an inner coating layer made of a composite oxide of silicon and aluminum on the surface of the hydrotalcite particles. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of hydrotalcite particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, and then pulverized, so that 100 parts by weight of hydrotalcite is a composite oxidation of silicon and aluminum. A polycondensation catalyst Y according to the present invention having 5 parts by weight of an inner coating layer made of a product and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester ao)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst Y was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 42
(Preparation of polycondensation catalyst Z)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining and maintaining the sodium silicate aqueous solution (as SiO _2). 29 wt%) 43.1 g and zirconium oxychloride aqueous solution (10 wt% as ZrO ₂ ) 256.7 g were added, and aging was carried out at pH 8.5 for 1 hour. Thereafter, filtration and washing were performed to form an inner coating layer made of a composite oxide of silicon and zirconium on the surface of the hydrotalcite particles. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of hydrotalcite particles having inner and outer coating layers obtained in this way is filtered, washed with water, dried and then pulverized, so that 100 parts by weight of hydrotalcite is a composite oxidation of silicon and zirconium. A polycondensation catalyst Z according to the present invention having 5 parts by weight of an inner coating layer made of a product and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester ap)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst Z was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 43
(Preparation of polycondensation catalyst AA)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the sodium aluminate aqueous solution (Al ₂ O) was heated and maintained at 60 ° C. ₃ as 19 wt%) 111.9G the aqueous solution of zirconium oxychloride (10 wt% as ZrO ₂₎ 256.6g was added, it was carried out for 1 hour and aged at pH 8.5. Thereafter, filtration and washing were performed to form an inner coating layer made of a composite oxide of aluminum and zirconium on the surface of the hydrotalcite particles. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of the hydrotalcite particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, and then pulverized, so that 100 parts by weight of hydrotalcite is a composite element of aluminum and zirconium. A polycondensation catalyst AA according to the present invention having 5 parts by weight of an inner coating layer made of oxide and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Production of polyester aq)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst AA was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Example 44
(Preparation of polycondensation catalyst AB)
After charging 5.0 L of the hydrotalcite water slurry (100 g / L) obtained in Reference Example 2 into a 25 L reactor, the temperature was maintained at 60 ° C. while maintaining and maintaining the sodium silicate aqueous solution (as SiO _2). 29 wt%) 28.7 g, sodium aluminate aqueous solution (19 wt% as Al ₂ O ₃ ) 74.6 g, and zirconium oxychloride aqueous solution (10 wt% as ZrO ₂ ) 171.1 g were added, and the pH was 8.5 for 1 hour. Aged. Thereafter, filtration and washing were carried out to form an inner coating layer made of a composite oxide of silicon, aluminum and zirconium on the surface of the hydrotalcite particles. To this hydrotalcite slurry having the inner coating layer, 0.7L of a titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) and 0.7 L of a sodium hydroxide aqueous solution (100 g / L in terms of NaOH) were added. Was simultaneously added dropwise over 2 hours so as to be 9.0. After the completion of dropping, the mixture was aged for 1 hour to form an outer coating layer made of titanic acid on the inner coating layer.

  The water slurry of the hydrotalcite particles having the inner and outer coating layers thus obtained is filtered, washed with water, dried, pulverized, and 100 parts by weight of hydrotalcite contains silicon, aluminum, and zirconium. A polycondensation catalyst AB according to the present invention having 5 parts by weight of an inner coating layer made of a complex oxide and 10 parts by weight of an outer coating layer made of titanic acid was obtained.

(Manufacture of polyester ar)
A polyester was obtained in the same manner as in Example 1 except that the polycondensation catalyst AB was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 1.

Comparative Example 1
(Manufacture of polyester as)
In Example 1, instead of the polycondensation catalyst A, 0.0061 g of antimony trioxide (2.1 × 10 ⁻⁵ mol, 0.03 mol part relative to 100 mol parts of dimethyl terephthalate) was used. In the same manner as in Example 1, a polyester was obtained. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 2
(Manufacture of polyester at)
In Example 2, instead of polycondensation catalyst A, 0.0114 g of antimony trioxide (3.9 × 10 ⁻⁵ mol, 0.015 mol part relative to 100 mol parts of terephthalic acid component subjected to polycondensation) was used. A polyester was obtained in the same manner as in Example 2 except that it was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 3
(Preparation of titanic acid)
7.2 L of titanium tetrachloride aqueous solution (69.4 g / L in terms of TiO ₂ ) was prepared. The titanium tetrachloride aqueous solution was charged into a 25 L reactor, and the titanium tetrachloride aqueous solution was added dropwise with stirring to a pH of 7.0. After completion of the dropping, titanic acid was filtered from the slurry, washed with water, and then refiltered to obtain a titanic acid cake (33 wt% in terms of TiO ₂ ).

(Manufacture of polyester au)
In Example 1, instead of the polycondensation catalyst A, 0.0051 g of the titanic acid cake (2.1 × 10 ⁻⁵ mol as TiO ₂ , 0.03 mol part relative to 100 mol parts of dimethyl terephthalate) A polyester was obtained in the same manner as in Example 1 except that it was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 4
(Production of polyester av)
In Example 2, instead of polycondensation catalyst A, 0.0093 g of titanic acid cake obtained in Comparative Example 3 (3.9 × 10 ⁻⁵ mol as TiO ₂ , 100 mol of terephthalic acid component used for polycondensation) A polyester was obtained in the same manner as in Example 2 except that 0.015 mol part) was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 5
(Preparation of a mixture of titanic acid and magnesium hydroxide)
After charging 9.0 L of the magnesium hydroxide slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, the titanic acid cake obtained in Comparative Example 3 (33 wt% in terms of TiO ₂₎ ) 335 g was added and stirred for 2 hours. After completion of stirring, the mixture was aged for 1 hour. The mixture was filtered from such a slurry, washed with water, dried and then pulverized to obtain a mixture of titanic acid and magnesium hydroxide. The proportion of titanic acid in this mixture was 10 parts by weight in terms of TiO _{2 with} respect to 100 parts by weight of magnesium hydroxide.

(Manufacture of polyester aw)
In Example 1, in place of the polycondensation catalyst A, 0.0013 g of the above mixture of titanic acid and magnesium hydroxide (2.1 × 10 ⁻⁵ mol, 0.03 mol part relative to 100 mol parts of dimethyl terephthalate) A polyester was obtained in the same manner as in Example 1 except that was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 6
(Manufacture of polyester ax)
In Example 2, instead of the polycondensation catalyst A, a mixture of titanic acid and magnesium hydroxide obtained in Comparative Example 5 0.0024 g (3.9 × 10 ⁻⁵ mol, terephthalic acid component 100 subjected to polycondensation 100 A polyester was obtained in the same manner as in Example 2 except that 0.015 mol part) was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 7
(Preparation of a mixture of titanic acid and hydrotalcite)
After 11.0 L of the hydrotalcite slurry (100 g / L) obtained in Reference Example 2 was charged into a 25 L reactor, the titanic acid cake obtained in Comparative Example 3 (33 wt% in terms of TiO ₂₎ 334 g was added and stirred for 2 hours. After completion of stirring, the mixture was aged for 1 hour. The mixture was filtered from such a slurry, washed with water, dried and then pulverized to obtain a mixture of titanic acid and hydrotalcite. The ratio of titanic acid in this mixture was 10 parts by weight in terms of TiO _{2 with} respect to 100 parts by weight of hydrotalcite.

(Production of polyester ay)
In Example 1, in place of the polycondensation catalyst A, 0.012 g (2.1 × 10 ⁻⁵ mol of the mixture of titanic acid and hydrotalcite, 0 with respect to 100 mol parts of the terephthalic acid component subjected to polycondensation) 0.030 mol part) was used in the same manner as in Example 1 to obtain a polyester. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 8
(Production of polyester az)
In Example 2, instead of the polycondensation catalyst A, 0.022 g (3.9 × 10 ⁻⁵ mol of a mixture of titanic acid and hydrotalcite obtained in Comparative Example 7 was used for polycondensation 100 A polyester was obtained in the same manner as in Example 2 except that 0.015 mol part) was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 9
(Preparation of a mixture of titanic acid, silicon oxide and magnesium hydroxide)
After charging 9.0 L of the magnesium hydroxide slurry (123 g / L) obtained in Reference Example 1 into a 25 L reactor, 110 g of silica (manufactured by Wako Pure Chemical Industries, Ltd.) and the titanic acid obtained in Comparative Example 3 were used. 335 g of cake (33% by weight in terms of TiO ₂ ) was added and stirred for 2 hours. After stirring, the mixture was aged for 1 hour. The mixture was filtered from such a slurry, washed with water, dried and then pulverized to obtain a mixture of titanic acid, silica and magnesium hydroxide.

(Production of polyester ba)
In Example 1, instead of the polycondensation catalyst A, 0.0013 g (2.1 × 10 ⁻⁵ mol, 0.03 mol with respect to 100 mol parts of dimethyl terephthalate) of the above titanic acid, silica and magnesium hydroxide Part) was used in the same manner as in Example 1 except that polyester was obtained. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Comparative Example 10
(Preparation of a mixture of titanic acid, silicon oxide and hydrotalcite)
After 11.0 L of the hydrotalcite slurry (100 g / L) obtained in Reference Example 2 was charged into a 25 L reactor, 110 g of silica (manufactured by Wako Pure Chemical Industries) and the titanic acid obtained in Comparative Example 3 were used. 334 g of cake (33% by weight in terms of TiO ₂ ) was added and stirred for 2 hours. After stirring, the mixture was aged for 1 hour. The mixture was filtered from such a slurry, washed with water, dried and pulverized to obtain a mixture of titanic acid, silicon oxide and hydrotalcite.

(Production of polyester bb)
In Example 1, instead of the polycondensation catalyst A, 0.012 g (2.1 × 10 ⁻⁵ mol of a mixture of titanic acid, silica and hydrotalcite, based on 100 mol parts of the terephthalic acid component subjected to polycondensation Polyester was obtained in the same manner as in Example 1, except that 0.030 mol part) was used. The intrinsic viscosity, color tone and haze value of the polyester thus obtained are shown in Table 2.

Claims (11)

A catalyst for producing a polyester by esterification reaction or transesterification reaction between a dicarboxylic acid or an ester-forming derivative thereof and glycol, and at least one element selected from silicon, aluminum and zirconium with respect to 100 parts by weight of a solid base 1 to 20 parts by weight of an inner coating layer made of a complex oxide of at least two elements selected from oxides of silicon, aluminum and zirconium, and an outer coating layer made of titanic acid in an amount of 0.1 to 50 in terms of TiO _2. A polycondensation catalyst comprising particles of the above solid base having parts by weight on the surface.   The polycondensation catalyst for producing a polyester according to claim 1, wherein the solid base is magnesium hydroxide.   The polycondensation catalyst for producing a polyester according to claim 1, wherein the solid base is hydrotalcite. While maintaining an aqueous slurry of solid base particles at a temperature of 5 to 100 ° C., 1 to 20 parts by weight of a water-soluble silicate and / or Al in terms of SiO _{2 with} respect to 100 parts by weight of the solid base. 1 to 20 parts by weight of water-soluble aluminate and acid in terms of ₂ O ₃ are added, and at least one elemental oxide selected from silicon and aluminum or silicon and aluminum on the surface of the solid base particles. An inner coating layer made of a composite oxide is formed, and then the aqueous solution of titanium halide is prepared so that the aqueous slurry of the solid base particles thus obtained has a pH of 5 to 12 at a temperature of 25 to 40 ° C. And an aqueous alkaline solution are added to form an outer coating layer composed of titanic acid on the inner coating layer, and then an aqueous slurry of solid base particles having the inner and outer coating layers is filtered. A catalyst for polyester production by esterification or transesterification of dicarboxylic acid or its ester-forming derivative and glycol obtained by washing with water, drying and pulverization, wherein the inner coating layer and the outer A polycondensation catalyst for producing polyester comprising particles of the solid base having a coating layer. While maintaining an aqueous slurry of solid base particles at a temperature of 5 to 100 ° C., 1 to 20 parts by weight of a water-soluble zirconium salt and an alkali in terms of ZrO ₂ are added to 100 parts by weight of the solid base. An inner coating layer made of zirconium oxide is formed on the surface of the solid base particles, and then the aqueous slurry of the solid base particles thus obtained has a pH of 5 to 5 at a temperature of 25 to 40 ° C. An aqueous titanium halide solution and an aqueous alkali solution are added so as to form an outer coating layer made of titanic acid on the inner coating layer, and then the aqueous solution of solid base particles having the inner and outer coating layers is formed. The slurry is filtered, washed with water, dried, and pulverized, which is obtained by esterification or transesterification of dicarboxylic acid or its ester-forming derivative and glycol. That a catalyst for polyester production, the surface on the inner coating layer and the polycondensation catalyst for polyester production consisting of particles of solid base having an outer coating layer. While maintaining the aqueous slurry of solid base particles at a temperature of 5 to 100 ° C., 1 to 20 parts by weight of water-soluble silicate and / or Al _{2 in} terms of SiO _{2 with} respect to 100 parts by weight of the solid base. 1 to 20 parts by weight of water-soluble aluminate in terms of O ₃ and 1 to 20 parts by weight of water-soluble zirconium salt in terms of ZrO ₂ are added, and the surface of the solid base particles is selected from silicon and aluminum. An inner coating layer composed of a complex oxide of at least one element and zirconium is formed, and then the aqueous slurry of the solid base particles thus obtained has a pH of 5 to 12 at a temperature of 25 to 40 ° C. A titanium base aqueous solution and an alkaline aqueous solution are added to form an outer coating layer made of titanic acid on the inner coating layer, and then a solid base having the inner and outer coating layers A catalyst for producing a polyester by esterification or transesterification of dicarboxylic acid or its ester-forming derivative and glycol, obtained by filtering, washing, drying and pulverizing an aqueous slurry of particles, A polycondensation catalyst for producing polyester comprising solid base particles having the inner coating layer and the outer coating layer.   The polycondensation catalyst for producing a polyester according to any one of claims 4 to 6, wherein the solid base is magnesium hydroxide.   The polycondensation catalyst for polyester production according to any one of claims 4 to 6, wherein the solid base is hydrotalcite.   The polycondensation catalyst for producing a polyester according to any one of claims 4 to 6, wherein the titanium halide is titanium tetrachloride.   A process for producing a polyester, characterized in that a dicarboxylic acid or an ester-forming derivative thereof and glycol are esterified or transesterified in the presence of the polycondensation catalyst according to any one of claims 1 to 9.   10. An oligomer comprising the aromatic dicarboxylic acid bis (hydroxylalkyl) ester is produced by esterification or transesterification of an aromatic dicarboxylic acid or an ester-forming derivative thereof with an alkylene glycol, and then the oligomer of claim 1 to 9 A process for producing a polyester, characterized in that the oligomer is melt polycondensed at high temperature under high vacuum in the presence of any of the polycondensation catalysts.