JP2003082207A - Polyester resin composition and blow molded product composed of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester resin composition scarcely emitting aldehydes and responsive to high required quality in fields such as containers or sheets. 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 the acetaldehyde content is <=15 ppm.

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 Polyethylene terephthalate resin is used as a material for containers such as carbonated drinks, juices and mineral waters due to its excellent transparency, mechanical strength, heat resistance and gas barrier property. Has been done. However, in recent years, there has been a demand for a material having more excellent properties than a container made of polyethylene terephthalate resin in terms of heat resistance, gas barrier property and the like. In order to meet such requirements, heat resistance than polyethylene terephthalate resin,
Polyethylene naphthalate with excellent gas barrier properties
The use of resin for containers is under consideration.

Japanese Unexamined Patent Publication (Kokai) No. 52-45466 discloses a polyethylene naphthalate excellent in heat resistance and gas barrier property.
Hollow containers from G.T. In addition, JP-A-2-
Japanese Patent No. 217222 describes a polyethylene naphthalate bottle highly stretched to have a stretching index of 130 cm or more, and a method for producing the same. However, in the case of polyethylene naphthalate resin, it is difficult to mold, and a hollow molded body having excellent transparency and a uniform wall thickness distribution has not been obtained. Further, JP-A-64-85732 discloses 2,6-naphthalene-
Dicarboxylic acid component 65 to 98.5 mol% and other dicarboxylic acid component (terephthalic acid, isophthalic acid, etc.) 35 to
A heat-resistant bottle made of a polyethylene naphthalate copolymer having 1.5 mol% and ethylene glycol as a main glycol component is described. However, when the content of the third component is 10 mol% or more, the melt-polymerized resin does not exhibit a melting point, and the crystallization rate becomes extremely slow, making it impossible to crystallize under practical conditions. Solid-phase polymerization treatment for the purpose of increasing the molecular weight and decreasing the content of acetaldehyde (AA is hereinafter abbreviated as AA) is impossible.

Further, in JP-A-2-274757 and JP-A-4-331255, a preliminary kneaded product of polyethylene terephthalate resin and polyethylene naphthalate resin is used as a mixture, or both are used. It has been shown that the use of a melt-kneaded product of a resin gives a composition, a container and the like having excellent heat resistance, transparency and gas barrier property. However, when such a mixture composition is used, the resulting container has poor heat resistance and transparency and a high AA content, so that only a hollow molded article having a low commercial value can be obtained. When both melt-kneaded compositions are used, the transparency is good, but AA
Only a hollow molded product having a very high content and very poor heat resistance can be obtained. Therefore, excellent moldings such as transparency, heat resistance, moldability, gas barrier property, and extremely low AA content such as hollow moldings, sheets, and stretched films are prepared by using polyethylene terephthalate resin and polyethylene naphthalate. The present invention has been accomplished as a result of extensive studies on the production of a resin mixture.

[0005]

The object of the present invention is to provide a thermoplastic polyester molded product and a hollow molded product which are excellent in heat resistance, gas barrier properties, transparency and mechanical properties, and also have a very low AA content. The present invention provides a film, a preform relating to these, and a polyester resin composition capable of forming these shaped bodies.

[0006]

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 300 m ²
/ G or more of silica, AA content of 15ppm
It is a polyester resin composition characterized by the following.

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. AA is 15 ppm or less by introducing an 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,
Furthermore, by using the catalyst deactivation by the conventional water treatment in combination, a polyester resin composition in which the AA of the molded product is reduced as compared with the conventional water treatment active resin can be obtained.

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

In this case, the density of the aromatic polyester having a repeating unit composed mainly of a terephthalic acid component and an ethylene glycol component is 1.3.
It can be 7 g / cm ³ or more and AA can be 15 ppm or less.

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 formed into a chip shape 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 chips after polymerization may be treated with treated water satisfying the following condition (c) in a treatment tank.

When the above polyester resin composition was melted at 290 ° C. for 60 minutes, the acetaldehyde content was W1 pp.
When the acetaldehyde content without melting treatment is set to W0ppm for 60 minutes at 290 ℃, ΔW = W1-W0 and ΔW is 100ppm
A polyester resin composition that can be:

[0014]

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 in which the aromatic dicarboxylic acid component contains 85 mol% or more of the acid component, More preferably, it is a crystalline polyester in which the aromatic dicarboxylic acid component contains 95 mol% or more of the acid component. Examples of typical aromatic polyesters include polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, and copolymers obtained by copolymerizing a part thereof with other dicarboxylic acid component or glycol component. it can.

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.

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

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

Examples of the dicarboxylic acid used by copolymerization in 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.

Carboxylic acid may be added within the range not impairing the content of the invention. As a method for 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 surface area used in the present invention is 300 m ² / g
The silica described above is referred to as silica sol or silica gel, including not only silica as a single component but also composite compositions containing silica as a base and other mixtures. 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 meters ² / g or more, more preferably 400 meters ²
/ G or more, most preferably 500 m ² / g or more, and if the surface area of silica is less than 300 m ² / g, the contents of AA and ΔW tend to increase. The upper limit of the surface area of silica is not particularly limited, but 5000 m ² /
It is preferably g or less, and more preferably 4000 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, and most preferably 0.5 wt%. 10w
If it exceeds t%, the haze tends to decrease, and 0.00
If the content is 01 wt% or less, the effect of reducing AA and ΔW tends to decrease.

The polyester resin composition of the present invention is dry blended into chips at any time during the polymerization of aromatic polyester (a method of adding at the time of esterification and / or at the end of esterification and / or at the time of polycondensation) or chips. However, it is preferably added during polymerization.

For example, terephthalic acid, ethylene glycol, silica having a surface area of 300 m ² / g or more and, if necessary, the above-mentioned copolymerization component are directly reacted to distill off water to esterify it, and then polycondensate under reduced pressure. Esterification method,
Alternatively, it is produced by a transesterification method in which dimethyl terephthalate, ethylene glycol and, if necessary, the above-mentioned copolymerization component 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 or a solution obtained by adding ethylene glycol to the solution and heating it 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.

Examples of the Ti compound include tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate and tetra-n-butyl titanate, and their partial hydrolysis. 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.

Also, 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 AA 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.

The polyester resin composition of the present invention is 29
ΔW when melted at 0 ° C for 60 minutes is 100pp
m or less, preferably 80 ppm or less, more preferably 60 ppm or less. When hollow molding is performed using a polyester resin composition having a ΔW of more than 101 ppm, it is not suitable for use in beverage bottles.

The polyester resin composition of the present invention contains a cyclic trimer, and its content is 0.45% by weight or less, preferably 0.33% by weight or less, more preferably 0.30% 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.

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 the melt polycondensation or after the 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 chips (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 treating water is exemplified 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 water treatment of aromatic polyester chips is carried out by a batch method, a silo type treatment tank may 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 the aromatic polyester chips are brought into contact with steam or a steam-containing gas for treatment, 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 for 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 aromatic polyester chips are subjected to the contact treatment with steam in a batch system, a silo type treatment apparatus may 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 chips of the aromatic polyester 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 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 with a draining device such as a vibrating screener or Simon Carter, if necessary, and transferred to the next drying step.

For drying the aromatic polyester chips which have been subjected to the contact treatment with water or steam, a commonly used aromatic polyester drying treatment 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 vacuum or while passing a small amount of drying gas under vacuum. 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 preferred 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 hollow molded article having excellent heat resistance by a known method such as a hot parison method or a 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.

[0057]

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 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) Acetaldehyde content (AA content) Sample / distilled water = 1 g / 2 cc was placed in a glass ampoule purged with nitrogen, the upper part was sealed and subjected to extraction treatment at 160 ° C. for 2 hours, and after cooling, in the extract Of acetaldehyde was measured by high sensitivity gas chromatography and the concentration was expressed in ppm. ΔW (AA increase amount) during melting of aromatic polyester Put 3 g of dried aromatic polyester chips into a glass test tube, and place in an oil bath at 290 ° C. under a nitrogen atmosphere.
Dip for 0 minutes to melt. ΔW during melting (AA increase)
Is calculated by the following equation. ΔW (increase of AA during melting (ppm)) = [A after melting
A (ppm) -AA amount before melting (ppm)]

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

(4) Content of Cyclic Trimer of Aromatic Polyester A sample is dissolved in a hexafluoroisopropanol / chloroform mixture solution, and chloroform is further 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.

(5) 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. Increasing amount of cyclic trimer during 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 four locations from the center of the body of the bottle after molding 5000 times (where the wall thickness was about 0.4 mm), and the haze was measured with a haze meter manufactured by Toyo Seisakusho. The average of four points was calculated.

(8) Haze unevenness of bottle After 10 times of molding, a sample was cut out from four places in the center of the body of the bottle (where the wall thickness was about 0.4 mm), and the haze was measured with a haze meter manufactured by Toyo Seisakusho. Maze = Maximum haze / Minimum haze

(9) Unevenness of bottle thickness Samples (3 cm x 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) A polyester resin composition was melt-extruded to obtain an unstretched sheet having a thickness of 0.3 mm, and a mold temperature of 165 ° C. was applied to the mold. Time 1.0 sec, Cycle time 1.2 sec [(Mold pressing 1.0 sec + Mold release 0.
2 seconds) / time], continuous molding was performed, and the number of times of molding until the dirt adhered to the mold was evaluated as the mold dirt. (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 The dried polyester resin composition was used as M-1 manufactured by Meiki Seisakusho.
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.

Hereinafter, the present invention will be specifically described 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.
Deciliter / gram, content of cyclic trimer is 0.30
%, AA content is 8 ppm, density is 1.400 g /
cm ³Met.

For water treatment of PET resin chips, the apparatus shown in FIG. 1 is used, and the raw material chip supply port (1) at the upper part of the processing 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 into the water treatment tank whose temperature was controlled at 95 ° C. at a rate of 50 kg / hour from the supply port (1) at the upper part of the treatment tank, and the treated water having a fine powder content of about 130 ppm was used for water treatment time. 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 ΔW (AA increase amount) at the time of melting was 36 ppm.

This composition was evaluated using an unstretched sheet and a biaxially stretched 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 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 containing 5 wt% of Q-3 manufactured by Fuji Silysia Chemical Ltd. were added to a first esterification reactor containing a reactant in advance. 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.

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 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 1. As is clear from Table 1,
ΔW (AA increase amount) at the time of melting in the obtained aromatic polyester resin composition was 148 ppm. Also, 7
Mold stains were confirmed by sheet molding and bottle molding about 000 times.

Similarly, the compositions of Examples 2 to 10 and Comparative Examples 1 to 4 in Table 2 were evaluated using unstretched sheets and biaxially stretched molded bottles according to the compositions shown in the table. The results are shown in Tables 1 and 2.

[0084]

[Table 1]

[0085]

[Table 2] 1) CX-200 Nippon Silica Co., Ltd. 2) Q-3 Fuji Silysia Co., Ltd. 3) Q-10 Fuji Silysia Co., Ltd. 4) MSH1 Mitsubishi Chemical Co., Ltd. 5) ST-EG Nissan Chemical ( Co., Ltd.

[0086]

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 an acetaldehyde content of 15 pp.
The present invention provides a polyester resin composition characterized in that the amount of acetaldehyde increased at the time of melting at 290 ° C. is 100 ppm 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) 3E033 AA01 BA17 CA03 CA08 CA16                       CA18 FA03 GA02                 4J002 CF04 CF06 CF07 CF08 DJ01                       GG01                 4J029 AA03 AB04 AB05 AD10 AE01                       AE03 BA03 BA04 BA05 BA10                       BD05 BD06 CB06 CB10 CB12                       CC06 HA01 HB01 JA29 KC02                       KD02 KE05 KH05 KJ03 KJ06

Claims (3)

[Claims] 1. An 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, and an acetaldehyde content of 15 ppm or less. And a polyester resin composition. 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 3. A polyester resin composition at 6 ° C. at 290 ° C.
Acetaldehyde content when melted for 0 minutes is W1pp
When the acetaldehyde content without melting treatment at 290 ° C. for 60 minutes is W0 ppm, ΔW = W1−W0 and ΔW is 10
It is 0 ppm or less, The polyester resin composition of Claim 1 or 2 characterized by the above-mentioned.