JP2003082208A - Polyester resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester resin composition having good mold releasability from a heat-treating metal mold during molding of blow molded products, scarcely staining the metal mold and excellent long-time continuous moldability and affording the blow molded products having excellent transparency and heat-resistant dimensional stability. SOLUTION: This polyester resin composition comprises an aromatic polyester having repeating units mainly composed of an aromatic dicarboxylic acid component and a glycol component and a silica having >=300 m<2> /g surface area. The polyester resin composition is characterized in that an increase in cyclic trimers is <=0.45% when melted at 290 deg.C temperature for 60 min.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester resin composition which is preferably used as a raw material for molded articles such as hollow molded containers such as beverage bottles, films and sheets, and in particular, hollow molded articles. The present invention relates to a polyester resin composition which gives a hollow molded article having excellent mold releasability from a heat treatment mold during molding, excellent long-term continuous moldability, and excellent transparency and heat-resistant dimensional stability.

[0002]

2. Description of the Related Art Aromatic polyesters having repeating units mainly composed of an aromatic dicarboxylic acid component and a glycol component have excellent transparency, mechanical strength, heat resistance,
Depending on characteristics such as gas barrier properties, carbonated drinks, juices,
It is used as a material for containers such as mineral water, and its spread is remarkable. In these applications, aromatic polyester bottles are hot-filled with a beverage that has been sterilized at high temperature, or the beverage is filled and then sterilized at high temperature. Shrinkage and deformation occur during the filling process, which is a problem. As a method for improving the heat resistance of an aromatic polyester bottle, there has been proposed a method in which a bottle mouth plug is heat-treated to increase the crystallinity, or a stretched bottle is heat-fixed. In particular, when the crystallization of the spout is insufficient or the crystallization degree varies greatly, the sealing property with the cap may be deteriorated and the contents may leak.

In order to improve the heat resistance of the body of the bottle, for example, as shown in Japanese Patent Publication No. 59-6216, a method of heat treatment by increasing the temperature of the stretching blow mold is adopted. However, if a large number of bottles are molded using the same mold by such a method, the bottles obtained with long-term operation will be whitened and the transparency will be reduced, and only bottles with no commercial value can be obtained. . It has been found that this is because deposits due to the aromatic polyester are attached to the mold surface, resulting in mold stains, which are transferred to the bottle surface. Particularly, in recent years, the molding speed has been increased along with the downsizing of bottles, and mold contamination has become a more serious problem from the viewpoint of productivity.

Further, in the case of a content liquid such as a fruit juice drink which requires hot filling, a method of crystallizing the mouth part of a preformed or molded bottle by heat treatment (Japanese Patent Laid-Open No. Sho 5).
The methods described in JP-A 5-79237 and JP-A-58-110221 are generally used. This way,
That is, the method of heat-treating the plug portion and the shoulder portion to improve the heat resistance, the time and temperature of the crystallization treatment have a great influence on the productivity, and an aromatic polyester which can be treated at a low temperature in a short time, in particular, An aromatic polyester having a repeating unit composed mainly of a terephthalic acid component and an ethylene glycol component, which has a high crystallization rate, is preferable. On the other hand, the body is required to be transparent even when subjected to heat treatment during molding so that the color tone of the filling is not deteriorated, and the spout and the body need to have contradictory properties.

[0005]

Various proposals have been made to solve such problems. For example, a method of adding an inorganic nucleating agent such as kaolin and talc to polyethylene terephthalate (JP-A-56-2342, JP-A-56-21832), a method of adding an organic nucleating agent such as a montanic acid wax salt. (Japanese Patent Laid-Open No. 57-125246 and Japanese Patent Laid-Open No. 57-207639), but these methods have problems in practical use because of the generation of foreign matter and cloudiness. In addition, a method of inserting a heat-resistant resin piece into the plug portion (Japanese Patent Laid-Open No. 61-259946 and Japanese Patent Laid-Open No. 2-2).
No. 69638) has been proposed, but the bottle productivity is poor and the recyclability is also a problem.

In order to solve the problem of mold stains, a method of reducing the cyclic trimer, which is the main component of the deposit on the mold surface, by solid-phase polymerizing the aromatic polyester in advance has been conventionally known. However, this method is insufficient in its effect because the cyclic trimer is regenerated when remelting and forming the parison. Japanese Patent Publication No. 3-47830 discloses a method of treating a polyester resin with water at 90 to 110 ° C. to suppress the activity of the catalyst and controlling the formation of a cyclic trimer during parison molding. . However, this method requires a special apparatus and processing time for the processing, and has a problem that the manufacturing process becomes complicated. Moreover, although the mold contamination is reduced for the time being by the above method,
It was insufficient, and in some cases, a sufficient effect was not obtained.

An object of the present invention is to solve the problems of the conventional polyester resin composition described above and to provide a polyester resin composition which does not pollute the mold.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that an aromatic polyester having a repeating unit mainly composed of an aromatic dicarboxylic acid component and a glycol component and a surface area 300m ² /
A polyester resin composition comprising g or more silica and having an increase in cyclic trimer of 0.45% by weight or less when melted at a temperature of 290 ° C. for 60 minutes.

By melt-molding the polyester resin composition of the present invention having the above-mentioned constitution, a molded product having excellent transparency and heat-resistant dimensional stability, particularly a hollow molded product such as a container, can be easily obtained. At a temperature of 290 ° C. by introducing aromatic polyester having a repeating unit mainly composed of an aromatic dicarboxylic acid component and a glycol component and silica having a surface area of 300 m ² / g or more into the polymerization.
The amount of cyclic trimer increase when melted for 0 minutes becomes 0.45% by weight or less, and further, the catalyst deactivation by the conventional water treatment is used in combination to stain the mold more than the conventional water treatment active resin. It is possible to obtain a polyester resin composition that is rare.

In this case, the aromatic polyester may have a repeating unit mainly composed of a terephthalic acid component and an ethylene glycol component.

Further, in this case, the density of the aromatic polyester having a repeating unit mainly composed of a terephthalic acid component and an ethylene glycol component is 1.3.
7 g / cm ³ or more, content of cyclic trimer is 0.45% by weight
It can be:

In this case, the intrinsic viscosity of the aromatic polyester having a repeating unit mainly composed of a terephthalic acid component and an ethylene glycol component is
It can be 0.55-0.90 deciliters / gram.

In this case, the polyester resin composition, which is formed into chips after polymerization, is treated with treated water satisfying the following conditions (a) and (b) in a treatment tank. be able to.

(A) Temperature 40 to 120 ° C. (B) Treated water including wastewater from the treatment tank

Furthermore, in this case, the polyester resin composition formed into a chip shape after polymerization may be treated with treated water satisfying the following condition (c) in a treatment tank. (C) Content of fine powder (C) of aromatic polyester is 10
Treated water below 00ppm

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the polyester resin composition of the present invention will be specifically described below.

The aromatic polyester used in the present invention is
A crystalline polyester mainly composed of an aromatic dicarboxylic acid component and a glycol component, preferably a crystalline polyester containing 85 mol% or more of the aromatic dicarboxylic acid component, more preferably an aromatic dicarboxylic acid component. A crystalline polyester containing 95 mol% or more of the acid component. As a typical aromatic polyester,
Polyethylene terephthalate, polyethylene-2,6-
Examples thereof include naphthalate, polybutylene terephthalate, and a copolymer obtained by copolymerizing a part of them with another dicarboxylic acid component or glycol component.

The aromatic dicarboxylic acid component constituting the aromatic polyester used in the present invention includes terephthalic acid, 2,6-naphthalenedicarboxylic acid and diphenyl-
Examples thereof include aromatic dicarboxylic acids such as 4,4-dicarboxylic acid and diphenoxyethanedicarboxylic acid and functional derivatives thereof.

As the glycol component constituting the aromatic polyester used in the present invention, aliphatic glycols such as ethylene glycol, trimethylene glycol, tetramethylene glycol and neopentyl glycol, and alicyclic glycols such as cyclohexanedimethanol are used. And so on.

Aromatic polyesters having a repeating unit mainly composed of a terephthalic acid component and an ethylene glycol component, which are preferably used in the present invention, are preferably linear polyesters containing 85 mol% or more of ethylene terephthalate units, and more preferably. Is an aromatic polyester composed of polyethylene terephthalate.

Examples of the dicarboxylic acid used by copolymerizing the aromatic polyester include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid and dicarboxylic acid. Aromatic dicarboxylic acids such as phenoxyethanedicarboxylic acid and functional derivatives thereof, oxyacids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, adipic acid,
Aliphatic dicarboxylic acids such as sebacic acid, succinic acid, glutaric acid, dimer acid and their functional derivatives, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexanedicarboxylic acid and their functional derivatives, etc. Can be mentioned.

Specific examples of the glycol component copolymerized in the aromatic polyester include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol and 1,5. -Pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,5-pentanediol, 2,2-diethyl-
1,3-propanediol, 2-butyl-2-ethyl-
1,3-propanediol, 1,9-nonanediol,
1,10-decanediol etc. are mentioned. As the alicyclic glycol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 3,8-bisvidoxymethyltricyclodisican, hydrogenated bisphenol A,
Examples thereof include hydrogenated bisphenol F and TCD glycol, and these can be used alone or in combination of two or more kinds.

To the extent that the contents of the invention are not impaired, a carboxylic acid may be added. As a method of introducing a carboxyl group, trimellitic anhydride, phthalic anhydride, pyromellitic anhydride are obtained by polymerizing the above polyester resin. , Succinic anhydride, 1,8-naphthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride, etc. are post-added to give an acid value,
Examples of the modified polyester include a method of chain extension with dimethylolpropionic acid, dimethylolbutanoic acid and the like. Furthermore, as the other copolymerization component used in the present invention by copolymerization in the aromatic polyester,
As a polyfunctional compound, as an acid component, trimellitic acid,
Pyromellitic acid and the like can be mentioned, and as the glycol component, glycerin and pentaerythritol can be mentioned. The amount of the above-mentioned copolymerization component used should be such that the aromatic polyester maintains a substantially linear shape.

The silica having a surface area of 300 m ² / g or more used in the present invention includes silica sol or silica sol or a composite composition containing silica as a single component and also other mixtures based on silica. It is called silica gel. The silica sol or silica gel may be a liquid and / or an aqueous solution of a water-soluble substance. As the water-soluble substance, various metal salts forming a complex oxide with silica, specifically, an inorganic acid such as nitric acid, hydrochloric acid, sulfuric acid, or phosphoric acid, or an acid such as an organic acid such as acetic acid or oxalic acid is used. , Gold, palladium, noble metals such as rhodium, nickel, zinc, iron, compounds with metals such as transition metals such as copper, more specifically, for example, calcium chloride, magnesium chloride, aluminum sulfate, titanium sulfate, zirconium sulfate, Examples thereof include iron chloride, sodium aluminate, silver nitrate, iron nitrate and the like. These are directly bonded to silica to form a composite oxide (for example, silica alumina, silica titania, etc.). In addition to metal salts, ammonium salts and the like may be used. Alternatively, it may be an aqueous solution of various dyes for coloring silica gel.

The surface area of the silica used in the present invention is preferably 300 m ² / g, more preferably 400 m ² / g or more, most preferably 500 m ² / g, and if the surface area of the silica is less than 300 m ² / g, it is cyclic. The content of trimer tends to increase. The upper limit of the surface area of silica is not particularly specified, but from a practical viewpoint, it is 5000 m ² / g or less, and further 4
It is preferably 000 m ² / g or less.

Silica having a surface area of 300 m ² / g or more used in the present invention is preferably 10 wt% or less with respect to the polyester resin, preferably 5 wt% or less, more preferably 2 wt% or less.
Most preferably 0.5 wt% or less and 10 wt% or less
%, Haze tends to decrease, and 0.000
If it is less than 01 wt%, the effect of the cyclic trimer increase control tends to decrease. The polyester resin composition of the present invention,
The aromatic polyester can be obtained at any time during polymerization (a method of adding at the time of esterification and / or completion of esterification and / or at the time of polycondensation), a method of dry blending into chips, etc., but preferably at the time of polymerization It is a method of adding.

The above aromatic polyester can be produced by a conventionally known production method.

For example, terephthalic acid, ethylene glycol, silica having a surface area of 300 m ² / g or more and, if necessary, the above copolymerization component are directly reacted to distill off water to esterify it, and then polycondensate under reduced pressure. It is produced by an esterification method or a transesterification method in which dimethyl terephthalate and ethylene glycol and, if necessary, the above-mentioned copolymerization components are reacted to distill off methyl alcohol for transesterification, followed by polycondensation under reduced pressure.

The melt polycondensation reaction may be carried out in a batch reactor or a continuous reactor. In any of these methods, the melt polycondensation reaction may be carried out in one step or may be carried out in multiple steps.
The solid phase polymerization reaction can be carried out by a batch type apparatus or a continuous type apparatus as in the melt polycondensation reaction. The melt polycondensation and solid phase polymerization may be carried out continuously or may be carried out separately.

In the case of the direct esterification method, compounds of Ge, Sb and Ti are used as the polycondensation catalyst, and it is particularly convenient to use the Ge compound or a mixture thereof with the Ti compound.

As the Ge compound, amorphous germanium dioxide, crystalline germanium dioxide powder or a slurry of ethylene glycol, a solution of crystalline germanium dioxide dissolved in water by heating, a solution of ethylene glycol added thereto and heat treatment, or the like is used. However, in particular, in order to obtain the polyester used in the present invention, it is preferable to use a solution in which germanium dioxide is dissolved in water by heating or a solution in which ethylene glycol is added and heated. These polycondensation catalysts can be added during the esterification process. When a Ge compound is used, the amount used is preferably 10 to 150 as the residual Ge amount in the polyester resin.
ppm, more preferably 13 to 100 ppm, still more preferably 15 to 70 ppm.

As the Ti compound, tetraalkyl titanate such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate and tetra-n-butyl titanate, and their partial hydrolysis are used. Examples thereof include titanyl oxalate, titanyl ammonium oxalate, sodium titanyl oxalate, potassium titanyl oxalate, titanyl calcium oxalate, titanyl oxalate compounds such as strontium titanyl oxalate, trimellitic acid titanium, titanium sulfate, titanium chloride and the like. The Ti compound is a formed polymer.
The amount of remaining Ti in the medium is preferably added so as to fall within a range of 0.1 to 10 ppm.

As the Sb compound, antimony trioxide,
Antimony acetate, antimony tartrate, potassium antimony tartrate, antimony oxychloride, antimony glycolate
, Antimony pentoxide, triphenylantimony, and the like. The Sb compound is added so that the amount of Sb remaining in the produced polymer is preferably in the range of 50 to 250 ppm.

As the stabilizer, it is preferable to use phosphoric acid, polyphosphoric acid, phosphoric acid esters such as trimethyl phosphate, or the like. These stabilizers can be added during the esterification reaction step from a slurry preparation tank of terephthalic acid and ethylene glycol. The P compound is added so that the amount of P remaining in the produced polymer is preferably in the range of 5 to 100 ppm.

Further, in order to control the DEG content in the polyester, a basic compound such as, for example,
Tertiary amines such as triethylamine and tri-n-butylamine, quaternary ammonium salts such as tetraethylammonium hydroxide and the like can be added.

Further, solid phase polymerization may be carried out in order to increase the intrinsic viscosity of the aromatic polyester and reduce the acetaldehyde content.

In the present invention, the intrinsic viscosity of the aromatic polyester forming the chip (a) of the aromatic polyester having a repeating unit mainly composed of a terephthalic acid component and an ethylene glycol component has an intrinsic viscosity of 0.55 to 1.30.
Preferably in deciliters / gram, from 0.58
1.00 deciliter / gram, and even 0.6-0.
More preferably it is 9 deciliters / gram. When the intrinsic viscosity of the polyester chip (a) is less than 0.55 deciliter / gram, the molded product obtained by melt-molding the polyester resin composition of the present invention has transparency, heat resistance, mechanical properties, etc. It may not be fully satisfied. In addition, the acetaldehyde content of the molded product tends to increase as the intrinsic viscosity exceeds 1.30 deciliters / gram, making it unsuitable for use in beverage bottles.

In the present invention, the intrinsic viscosity of the fine polyester (b) of an aromatic polyester having a repeating unit mainly composed of a terephthalic acid component and an ethylene glycol component is usually 0.55 to 1.30, preferably 0. ．
57 to 1.00, more preferably 0.58 to 0.90
Is. If the intrinsic viscosity is less than 0.55, the resulting molded article will have poor transparency and the crystallinity of the plug portion will be too large. Further, it is preferable that it is the same as the intrinsic viscosity of the PET resin chip, or is in the range of 0.03 higher than the intrinsic viscosity of the PET resin chip to 0.03 higher than the intrinsic viscosity of the PET resin chip.

The polyester resin composition of the present invention contains a cyclic trimer, and its content is 0.45% by weight or less, preferably 0.40% by weight or less, more preferably 0.35% by weight or less. Is. When a heat-resistant hollow molded article is molded from the polyester resin composition of the present invention, heat treatment is carried out in a heating mold. When the content of the cyclic trimer is 0.45% by weight or more, the heating mold is heated. Adhesion of oligomers to the mold surface sharply increases, and the transparency of the obtained hollow molded article is extremely deteriorated.

The polyester resin composition of the present invention is 29
The amount of increase of the cyclic trimer when melted at a temperature of 0 ° C. for 60 minutes is 0.30% by weight or less, preferably 0.25% by weight or less, more preferably 0.20% by weight or less. When hollow molding is carried out using a polyester resin composition in which the amount of cyclic trimer increase exceeds 0.30% by weight, oligomers such as cyclic trimers are formed on the inner surface of the mold, the gas exhaust port of the mold, and the exhaust pipe. To obtain a transparent hollow molded container that adheres to the mold, the mold must be frequently cleaned.

The polyester resin composition of the present invention, in which the amount of increase of the cyclic trimer when melted at a temperature of 290 ° C. for 60 minutes is 0.40 wt% or less, is obtained after melt polycondensation or solid phase polymerization. It can be produced by deactivating the polycondensation catalyst of the polyester.

Examples of the method for deactivating the polycondensation catalyst of the aromatic polyester include a method of subjecting the aromatic polyester chips to contact treatment with water, water vapor or a gas containing water vapor after melt polycondensation or after solid phase polymerization. .

A method of contacting the aromatic polyester chips with water, steam or a gas containing steam to achieve the above object will be described below.

The shape of the aromatic polyester chip (A) may be any of cylinder type, square type, flat plate type, etc., and the size thereof is usually 1 in length, width and height. The range is from 8 to 4 mm, preferably from 2 to 4 mm. For example, in the case of a cylinder type, the length is 2-4
mm, the diameter is practically about 2 to 4 mm.

Examples of the hot water treatment method include a method of immersing in hot water and a method of spraying water on the chips with a shower. The treatment time is 5 minutes to 2 days, preferably 10 minutes to 1 day, more preferably 30 minutes to 10 hours, and the water temperature is 20 to 180 ° C., preferably 40 to 150.
C., more preferably 50 to 120.degree.

The method of industrially performing water treatment is illustrated below, but the method is not limited to this. The treatment method may be either a continuous method or a batch method, but the continuous method is preferable for industrial use.

When the chips of aromatic polyester are subjected to water treatment in a batch system, a silo type treatment tank can be used. That is, the aromatic polyester chips are received in silos in a batch system and treated with water. Alternatively, it is also possible to receive the aromatic polyester chips in a rotary cylinder type treatment tank and to perform water treatment while rotating to make the contact with water more efficient.

When the aromatic polyester chips are continuously treated with water, the aromatic polyester chips are continuously or intermittently received from the upper part in a tower-type treatment tank,
It can be treated with water. This conceptual diagram is shown in FIG.

When processing is carried out by bringing the chips of aromatic polyester into contact with steam or a steam-containing gas, 50
Steam or steam-containing gas or steam-containing air at a temperature of 150 to 150 ° C., preferably 50 to 110 ° C., is preferably supplied or present in an amount of 0.5 g or more as steam per 1 kg of granular polyethylene terephthalate. Contacting terephthalate and water vapor.

The contact between the aromatic polyester chips and the steam is usually 10 minutes to 2 days, preferably 2 minutes.
It is performed for 0 minutes to 10 hours.

The method of industrially carrying out the contact treatment between the granular polyethylene terephthalate and steam or a steam-containing gas will be illustrated below, but the method is not limited to this. Further, the treatment method may be either a continuous method or a batch method.

When the chips of the aromatic polyester are subjected to contact treatment with steam in a batch system, a silo type treatment apparatus can be used. That is, chips of aromatic polyester are received in a silo, and steam or a steam-containing gas is supplied in a batch method to perform contact treatment. Alternatively, the granular polyethylene terephthalate may be received in a rotating tube type contact treatment device, and the contact treatment may be performed while rotating to make the contact more efficient.

When the aromatic polyester chips are continuously contacted with steam, granular polyethylene terephthalate is continuously received from the upper part in a tower-type processing apparatus, and steam is continuously supplied in a cocurrent or countercurrent to contact with steam. Can be made.

As described above, when treated with water or steam, the granular polyethylene terephthalate is drained by a draining device such as a vibrating screener or Simon Carter, if necessary, and transferred to the next drying step.

For the drying of the aromatic polyester chips which have been contact-treated with water or steam, a commonly used drying treatment for aromatic polyesters can be used. As a method for continuously drying, a hopper-type ventilation dryer in which chips of aromatic polyester are supplied from the upper part and a dry gas is aerated from the lower part is usually used. As a method of reducing the amount of dry gas and efficiently drying, a rotating disk type continuous dryer is used, and while supplying a small amount of dry gas, heating steam and heating medium are supplied to the rotating disk and the outer jacket. The chips of aromatic polyester can be heated and dried indirectly.

A double-cone type rotary dryer is used as a dryer for batch-type drying, and it can be dried under a vacuum or under a vacuum while a small amount of dry gas is passed through. Alternatively, it may be dried under atmospheric pressure while aerating a dry gas.

Although atmospheric air may be used as the dry gas, dry nitrogen and dehumidified air are preferable from the viewpoint of preventing a decrease in molecular weight due to hydrolysis or thermal oxidative decomposition of the aromatic polyester.

By subjecting the aromatic polyester to water or steam treatment as described above, the amount of increase in oligomer after the polyethylene terephthalate is heated and melted at a temperature of 290 ° C. can be suppressed.

When the aromatic polyester is an aromatic polyester having a repeating unit mainly composed of a terephthalic acid component and an ethylene glycol component, the polyester resin composition of the present invention is molded by heating and melting at a temperature of 290 ° C. When the Tc1 of the molded product is measured, it is preferable that the Tc1 is 155 to 175 ° C. and the haze is 15% or less. When Tc1 is lower than 155 ° C., the transparency of the molded product becomes very poor. Also, Tc
When 1 is higher than 175 ° C., the transparency of the molded product is very good, but in the case of a bottle, the crystallinity of the plug part is low, and the content may leak after filling and capping. Further, when a polyester resin composition in which the haze of the molded product is 15% or more is used, the transparency becomes extremely poor in the case of a bottle.

The polyester resin composition of the present invention can be used to produce a transparent, heat-resistant hollow molded article by a known method such as the hot parison method or the cold parison method. It is also preferable to produce a molded product such as a film or a sheet, or a multilayer hollow molded product.

In the polyester resin composition of the present invention, if necessary, known ultraviolet absorbers, lubricants, release agents, nucleating agents,
You may mix | blend various additives, such as a stabilizer, an antistatic agent, and a pigment.

[0062]

EXAMPLES The present invention will be described below with reference to examples. In the examples, "parts" means "parts by weight". Moreover, each measurement item followed the following method.

(1) Silica Surface Area BET Specific Surface Area After measuring the adsorption and desorption isotherms of nitrogen using ASAP-2400 manufactured by Shimadzu Corporation, S. Brunauer, P.
It was measured by the method described in H. Emett, E. Teller method, J. Am. Chem. Soc., 60309 (1938).

(2) Intrinsic viscosity (IV) of aromatic polyester Determined from solution viscosity at 30 ° C. in a mixed solvent of 1,1,2,2-tetrachloroethane / phenol (2: 3 weight ratio).

(3) Content of cyclic trimer of aromatic polyester A sample is dissolved in a hexafluoroisopropanol / chloroform mixture, and chloroform is added to dilute it. Methanol is added to this to precipitate the polymer, which is then filtered. The filtrate was evaporated to dryness, the volume was made constant with dimethylformamide, and the cyclic trimer composed of ethylene terephthalate units was quantified by liquid chromatography.

(4) Increasing amount of cyclic trimer during melting of aromatic polyester (ΔCT) 3 g of dried aromatic polyester chips were placed in a glass test tube and placed in an oil bath at 290 ° C. under a nitrogen atmosphere. 6
Dip for 0 minutes to melt. The amount of cyclic trimer increase during melting is determined by the following formula.

Increase in cyclic trimer at melting (% by weight) =
[Content of cyclic trimer after melting (% by weight) -Content of cyclic trimer before melting (% by weight)]

(6) Density of aromatic polyester chips 25 with a density gradient tube of carbon tetrachloride / n-heptane mixed solvent
It was measured at ° C.

(7) Haze of bottle (% haze) Samples were cut at 4 locations from the center of the body of the bottle after molding 5000 times (location with a wall thickness of about 0.4 mm), and haze was measured with a haze meter manufactured by Toyo Seisakusho. The average of four points was calculated.

(8) Haze unevenness of bottle Four samples were cut from the center of the body of the bottle after molding 10 times (at a thickness of about 0.4 mm), and haze was measured with a haze meter manufactured by Toyo Seisakusho. Maze = Maximum haze / Minimum haze

(9) Uneven thickness of the bottle Samples (3 cm × 4 cm) randomly from the center of the body of the bottle
3 cm) was cut out and its thickness was measured with a digital thickness meter (the same sample was measured at 5 points each and the average was taken as the sample thickness). Thickness unevenness = maximum thickness / minimum thickness

(10) Capping Property 1500 cc of water at 90 ° C. was put in a molded bottle, and a polypropylene resin screw cap equipped with a polypropylene resin inner seal was used. This bottle filled with water is laid down sideways, and at 5 ° C for 10 hours,
Subsequently, a leaving test was carried out at 80 ° C. for 10 hours to check the contents for leakage. The test was conducted with 5 bottles, and the number of bottles in which leakage of the content was recognized was counted.

(11) Evaluation of mold stain (evaluation by unstretched sheet) The polyester resin composition was melt extruded to a thickness of 0.
An unstretched sheet of 3 mm was obtained, the mold temperature was 165 ° C., the pressing time to the mold was 1.0 second, the cycle time was 1.2 seconds [(mold pressing 1.0 second + release 0.2 second) / time. ], Continuous molding was performed, and the number of times of molding until the stain adhered to the mold was evaluated as the mold stain. (Evaluation using a biaxially stretch-molded container) The polyester resin composition was dried with a dryer using dehumidified air, and manufactured by Meiki Seisakusho M.
A preform was molded with a -100 injection molding machine at a resin temperature of 290 ° C. The plug part of this preform is heated and crystallized by a homemade plug part crystallization device, and then biaxially stretch blow molded using a LB-01 stretch blow molding machine manufactured by Corpoplast, and subsequently set at 155 ° C. 10 in the mold
After heat setting for 2 seconds, a 500 cc hollow molded container was obtained. Stretch blow molding was continuously carried out under the same conditions, and the mold stain was evaluated by the number of moldings until the transparency of the container was impaired by visual observation. As the haze measurement sample, the body of the container after continuous molding for 5,000 times was used.

(12) Tc1 (DSC measurement) Differential thermal analyzer (DS
C), sample 10 from the center of the 2 mm thick plate of the molded plate molded in (13) below with RDC-220.
mg was used, and the temperature rising rate was measured at 20 ° C./min.

(13) Haze of Molded Plate (% haze) The haze meter manufactured by Toyo Seiki Seisaku-sho, Ltd. was used using the following molded plate having a thickness of 5 mm.

(14) Molding of Molded Plate A dried polyester resin composition was manufactured by Meiki Seisakusho M-1.
Molding is carried out using a 00 flat plate mold cooled to 10 ° C. at a cylinder temperature of 290 ° C. by an injection molding machine. Stepped flat plate dies are 2, 3, 4, 5, 6, 7, 8, 9, 10,
The plate is provided with a 3 cm × 5 cm square plate having a thickness of 11 mm in a stepwise manner. The measurement is an average value of three molded plates. The 2 mm thick plate was used for Tc1 measurement by DSC, and the 5 mm thick plate was used for haze (% haze) measurement.

[Examples] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 A slur was continuously added to a first esterification reactor containing a reactant in advance so that high-purity terephthalic acid, ethyl glycol, and CX200 manufactured by Nippon Silica Co., Ltd. were 2 wt%. To about 250 with stirring.
The reaction was conducted at 0.5 ° C. and 0.5 kg / cm ² G for an average residence time of 3 hours. In addition, crystalline germanium dioxide was heated and dissolved in water, ethylene glycol was added thereto and heat treated, and an ethylene glycol solution of phosphoric acid was separately fed continuously to the first esterification reactor. The reactant is sent to the second esterification reactor and stirred for about 260
The reaction was carried out at a temperature of 0.05 kg / cm ² G to a predetermined degree of reactivity. This esterification reaction product is continuously sent to the first polymerization reactor and stirred at about 265 ° C. and 25 torr for 1 hour.
Time, then at about 265 ° C, 3 with stirring in the second polymerization reactor
Polymerization was carried out at 0.5 to 1 torr at about 275 ° C. for 1 hour under stirring at 3 torr for 1 hour. The obtained PET resin has an intrinsic viscosity (IV) of 0.53, DE
G content is 2.7 mol%, CX200 manufactured by Nippon Silica Co., Ltd.
Was 2 wt%.

This resin was continuously treated under a nitrogen atmosphere for about 15 minutes.
Crystallize at 5 ° C, preheat to about 200 ° C under nitrogen atmosphere, and send to continuous solid-state polymerization reactor for about 20 minutes under nitrogen atmosphere.
Solid state polymerization was carried out at 5 ° C. After the solid phase polymerization, fine particles were removed by continuous treatment in a sieving step and a fine particle removing step.

The PET resin thus obtained had an intrinsic viscosity of 0.74.
The volume was deciliter / gram, the content of cyclic trimer was 0.30% by weight, and the density was 1.400 g / cm3.

For the water treatment of PET resin chips, the apparatus shown in FIG. 1 was used, and the raw material chip supply port (1) at the upper part of the treatment tank,
An overflow outlet (2) located at the upper limit level of the treated water in the treatment tank, an outlet (3) for the mixture of aromatic polyester chips and treated water in the lower portion of the treatment tank, and treated water discharged from this overflow outlet, Fine powder removing device (5) in which the treated water discharged from the treatment tank and the treated water discharged from the discharge item at the bottom of the treatment tank via the draining device (4) are continuous filters with a filter material made of paper of 30 μm (6) to be sent again to the water treatment tank via the water, an inlet (7) for the treated water from which the fine powder has been removed, an adsorption tower (8) for adsorbing acetaldehyde in the treated water to which the fine powder has been removed, and new ions. Approximately 32 in volume with exchange water inlet (9)
A 0 liter tower type processing tank was used.

The treated water was continuously charged at a rate of 50 kg / hour from the supply port (1) at the upper part of the treated tank into the treated water whose temperature was controlled at 95 ° C., and the treated water having a fine powder content of about 130 ppm was used for treating the water. After 4 hours, PET chips were continuously extracted together with the treated water from the outlet (3) at the bottom of the treatment tank at a rate of 50 kg / hour. The amount of silica contained in the obtained PET resin composition was 2 wt% and the cyclic trimer increase amount (ΔCT) at the time of melting was 0.04 wt%.

The composition was evaluated using an unstretched sheet and a biaxially stretched bottle. The results are shown in Table 1. As is apparent from Table 1, after 15,000 or more sheet moldings and bottle moldings, virtually no mold stain was observed, the transparency (haze) of the bottle was good, and uneven haze and uneven thickness were also problems. There was no Further, this bottle was filled with 90 ° C. hot water, capped with a capping machine, and then the bottle was laid down and left to stand, and the deformation of the spout and the leakage of the contents were examined, but there was no problem.

(Example 2) A high-purity terephthalic acid, ethyl glycol, and a slurry of Q-3 manufactured by Fuji Silysia K.K. Using the same solid-phase polymerized PET resin as in Example 1, which was continuously supplied, water treatment was performed in the same water treatment tank by the same method as in Example 1.

This composition was evaluated using an unstretched sheet and a biaxially stretch-molded bottle. The results are shown in Table 1. As is apparent from Table 1, after 15,000 or more sheet moldings and bottle moldings, virtually no mold stain was observed, the transparency (haze) of the bottle was good, and uneven haze and uneven thickness were also problems. There was no Further, this bottle was filled with hot water at 90 ° C., capped with a capping machine, and then the bottle was laid down and left to stand, and then deformation of the spout and leakage of the contents were examined, but there was no problem.

(Comparative Example 1) A slurry of high-purity terephthalic acid and ethyl glycol was continuously fed to a first esterification reactor containing a reactant in advance, and the slurry was stirred for about 25 minutes.
The reaction was carried out at 0 ° C. and 0.5 kg / cm ² G for an average residence time of 3 hours. In addition, crystalline germanium dioxide was heated and dissolved in water, ethylene glycol was added thereto and heat treated, and an ethylene glycol solution of phosphoric acid was separately fed continuously to the first esterification reactor. The reaction mass is sent to the second esterification reactor and stirred for about 26
The reaction was carried out at 0 ° C. and 0.05 kg / cm ² G to a predetermined degree of reactivity. The esterification reaction product is continuously sent to the first polymerization reactor, and is stirred at about 265 ° C. at 25 torr for 1 hour, and then is stirred at the second polymerization reactor at about 265 ° C.
At 3 torr for 1 hour, with stirring in the third polymerization reactor,
Polymerization was carried out at about 275 ° C. and 0.5 to 1 torr for 1 hour.
The obtained PET resin has an intrinsic viscosity (IV) of 0.53, D
The EG content was 2.7 mol%. The same solid-state polymerized PET resin as in Example 1 was immersed in distilled water in a glass container, heated from the outside and treated at an internal temperature of about 95 ° C. for 4 hours. This was dried to obtain the polyester resin composition of the present invention. This composition was evaluated using an unstretched sheet and a biaxially stretched molded bottle. The results are shown in Table 2. As is clear from Table 2, the amount of cyclic trimer increase in the obtained aromatic polyester resin composition at the time of melting was 0.08% by weight. Further, mold stains were confirmed by sheet molding and bottle molding about 7,000 times. In the same manner, the compositions of Examples 2 to 5 and Comparative Examples 1 and 2 in Table 2 were evaluated using unstretched sheets and biaxially stretched molded bottles in the same manner with the compositions shown in Table 1. The results are shown in Tables 1 and 2.

[0087]

[Table 1]

[0088]

[Table 2] 1) CX-200 Nippon Silica Co., Ltd. 2) Q-3 Fuji Silysia Co., Ltd. 3) Q-10 Fuji Silysia Co., Ltd. 4) G-3 Fuji Silysia Co., Ltd. 5) EG-ST Nissan Made by Kagaku Co., Ltd.

[0089]

The present invention comprises an aromatic polyester having repeating units mainly composed of an aromatic dicarboxylic acid component and a glycol component and silica having a surface area of 300 m ² / g or more and melted at a temperature of 290 ° C. for 60 minutes. The polyester resin composition is characterized in that the amount of cyclic trimer increase is 0.45% by weight or less, and can meet high quality requirements in the fields of containers, sheets and the like.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a water treatment device used in Examples.

Continued front page    F term (reference) 4J002 CF041 CF061 DJ016 FD016                       GG00                 4J029 AA03 AB05 AC01 AD01 AE03                       BA02 BA03 BA04 BA05 BA07                       BA08 BA10 BD06A BD10                       CA02 CA04 CA05 CA06 CB04A                       CB05A CB06A CB10A CC06A                       CD03 CF15 EA02 EB05A                       GA22 HA01 HB01 HB03A                       JA061 JA091 JA201 JB131                       JB171 JB201 JF321 JF361                       JF471 KH03

Claims (2)

[Claims] 1. A ring formed by melting an aromatic polyester having repeating units mainly composed of an aromatic dicarboxylic acid component and a glycol component and silica having a surface area of 300 m ² / g or more at a temperature of 290 ° C. for 60 minutes. A polyester resin composition, wherein the amount of trimer increase is 0.45% by weight or less. 2. A polyester resin composition, which is formed into chips after polymerization and is treated with treated water satisfying the following conditions (a) and (b) in a treatment tank. The polyester resin composition according to claim 1. (A) Temperature 40 to 120 ° C. (b) Treated water including wastewater from the treatment tank