JP2002294056A - Polyester resin composition and bottle by injection blow holding, comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a polyester resin composition which can efficiently provide a molding with heat resistance without reducing transparency by a heat treatment and is especially useful for injection blow molding of bottle and a bottle by injection blow molding. SOLUTION: This polyester resin composition is a resin composition comprising a polyester resin which is composed of an ethylene terephthalate unit as a main constitutent repeating unit, 0.08-2 mol/ton calculated as antimony atom (Sb) of an antimony compound, 0-0.2 mol/ton calculated as titanium atom (Ti) of a titanium compound, respectively and has 0.6-1.2 dl/g intrinsic viscosity and 0.0001-1,000 ppm of a polyolefin resin or a polyamide resin, having 155-165 deg.C heat-up crystallization temperature (Tc1 ) and <=180 deg.C temperature-fall crystallization temperature (Tc2 ) or not being observed after forming a molding. This bottle by injection blow molding comprises the polyester resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition and an injection blow bottle comprising the same, and more particularly, to a heat treatment which can efficiently impart heat resistance to a molded article without lowering transparency. In particular, the present invention relates to a polyester resin composition useful for molding an injection blow bottle and an injection blow bottle comprising the same.

[0002]

2. Description of the Related Art Conventionally, polyethylene terephthalate resins have been used as bottles for beverages, liquid detergents, cosmetics, etc. in addition to excellent mechanical properties and chemical properties, as well as excellent transparency, gas barrier properties, safety and hygiene properties, and the like. It has been noticed from the side and has shown remarkable growth.

[0003] These polyethylene terephthalate resin bottles are usually formed by stretch-blow-molding an injection-molded preform in a blow mold. In bottles, in order to increase the heat resistance of the bottle, the preform or the plug portion of the bottle is subjected to heat treatment with an infrared heater or the like to be crystallized. In order to increase the density of the body, the temperature of the blow mold is set to a high temperature of about 120 to 180 ° C. to promote crystallization of the body.

[0004] As the polyethylene terephthalate resin material for bottle molding, a polyethylene terephthalate resin produced by using an antimony compound, which is frequently used as a polycondensation catalyst, as a polycondensation catalyst is used because the crystallization rate is too high and the bottle molding is too slow. However, polyethylene terephthalate resin produced using a germanium compound as a polycondensation catalyst is mainly used because there is a problem that transparency is significantly reduced due to these heat treatments, but polyethylene using a germanium compound as a polycondensation catalyst is used. Terephthalate resin is not only economically problematic because the germanium compound itself is expensive, but also contaminates the blow molding mold set at a high temperature, impairs the surface smoothness of the resulting bottle and has poor transparency. There was a problem that it became easy.

On the other hand, in order to prevent a decrease in transparency during the heat treatment in a polyethylene terephthalate resin using an antimony compound as a polycondensation catalyst, for example, as a polycondensation catalyst, in addition to the antimony compound, a titanium compound or a germanium compound, and , Magnesium compounds and phosphorus compounds (for example, JP-A-2000-21)
9726, JP-A-2000-219730, JP-A-20
00-226444, JP-A-2000-226445
JP-A-2000-226446, JP-A-2000-2
26500, etc. Many proposals have been made on the surface of polycondensation catalysts. However, according to the studies by the present inventors, the crystallization rate is slow, and the heat treatment at the time of bottle molding requires time, It has been found that there is a local difference in the degree of crystallinity between the inside and the outside of the plug, and the dimensional accuracy of the plug is not stable.

[0006] The applicant of the present invention has previously proposed whether a polyethylene terephthalate resin is brought into contact with a member made of a crystalline thermoplastic resin such as polyethylene under flow conditions (Japanese Patent Laid-Open No. 9-7 / 1997).
See No. 1639. ) Alternatively, a small amount of a crystalline thermoplastic resin such as polyethylene is blended with polyethylene terephthalate resin (JP-A-9-151308 and JP-A-9-151308).
See the publications of 194697. ), A method of lowering the crystallization temperature of polyethylene terephthalate resin by adding a small amount of crystalline thermoplastic resin was proposed. However, the methods described in these publications provide some improvement in the crystallization rate of the polyethylene terephthalate resin, but in terms of stabilizing the quality of the crystallization characteristics,
It was hard to say that the market demand was fully satisfied.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned situation, and accordingly, the present invention provides a heat treatment for efficiently imparting heat resistance to a molded article without reducing transparency. An object of the present invention is to provide a polyester resin composition which can be applied, and is particularly useful for molding an injection blow bottle, and an injection blow bottle comprising the same.

[0008]

According to the present invention, an ethylene terephthalate unit is used as a main constituent repeating unit, and an antimony compound is used as an antimony atom (Sb) in an amount of from 0.08 to 0.08.
2 mol / ton, and a titanium compound with a titanium atom (T
i) a polyester resin containing 0 to 0.2 mol / ton, each having an intrinsic viscosity of 0.6 to 1.2 dl / g, and a polyolefin resin or polyamide resin contained in an amount of 0.0001 to 1000 ppm. A polyester having a temperature rising crystallization temperature (T _c1 ) of 155 to 165 ° C. and a falling temperature crystallization temperature (T _c2 ) of 180 ° C. or less or not observed after forming a molded article. The gist is a resin composition and an injection blow bottle made of the polyester resin composition.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester resin in the polyester resin composition of the present invention has an ethylene terephthalate unit as a main constituent repeating unit, and its ester such as terephthalic acid or an alkyl ester having about 1 to 4 carbon atoms. Forming derivative is 9 of all dicarboxylic acid components
It is a polycondensate of a dicarboxylic acid component occupying 8 mol% or more and a diol component in which ethylene glycol accounts for 95 mol% or more of all diol components, and the ethylene terephthalate unit occupies 93 mol% or more of the constitutional repeating unit. Is preferred. If the ethylene terephthalate unit is less than 93 mol%, the mechanical strength and heat resistance of the molded article tend to be poor.

The dicarboxylic acid components other than terephthalic acid and its ester-forming derivative include, for example, phthalic acid, isophthalic acid, phenylenedioxydicarboxylic acid,
4,4′-diphenyl dicarboxylic acid, 4,4′-diphenyl ether dicarboxylic acid, 4,4′-diphenyl ketone dicarboxylic acid, 4,4′-diphenoxyethane dicarboxylic acid, 4,4′-diphenyl sulfone dicarboxylic acid,
Aromatic dicarboxylic acids such as 2,6-naphthalenedicarboxylic acid and the like, alicyclic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid, and succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, and azelaic acid One or more of aliphatic dicarboxylic acids such as sebacic acid, undecadicarboxylic acid and dodecadicarboxylic acid, and ester-forming derivatives of these dicarboxylic acids may be used as a copolymerization component.

As diol components other than ethylene glycol, for example, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, neopentyl glycol, diethylene glycol, polyethylene glycol, polytetraethylene glycol Aliphatic diols such as methylene ether glycol, 1,
2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexane dimethylol, 1,
Alicyclic diols such as 4-cyclohexane dimethylol,
And xylylene glycol, 4,4′-dihydroxybiphenyl, 2,2-bis (4′-hydroxyphenyl) propane, 2,2-bis (4′-β-hydroxyethoxyphenyl) propane, bis (4-hydroxy One or two or more aromatic diols such as phenyl) sulfone and bis (4-β-hydroxyethoxyphenyl) sulfonic acid may be used as the copolymerization component.

Further, for example, hydroxycarboxylic acids and alkoxycarboxylic acids such as glycolic acid, p-hydroxybenzoic acid and p-β-hydroxyethoxybenzoic acid, and stearyl alcohol, benzyl alcohol, stearic acid, benzoic acid, t- Monofunctional components such as butylbenzoic acid and benzoylbenzoic acid, and trifunctional or higher functionalities such as tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, gallic acid, trimethylolethane, trimethylolpropane, glycerol and pentaerythritol. One or more functional components may be used as the copolymer component.

The polyester resin of the present invention is obtained by polycondensing the dicarboxylic acid component and the diol component together with a copolymer component used as required, in the presence of an antimony compound. The antimony compound is contained in the resin, and the amount of the antimony compound used in the polycondensation and the content in the polyester resin accompanying the polycondensation are as follows.
0.08 to 0.08 as antimony atom (Sb) per ton
It is essential that the amount be 2 mol, and the amount is preferably 0.2 to 1.7 mol. When the content of the antimony compound as an antimony atom (Sb) is less than the above range, the polycondensability is reduced, and the content of cyclic trimers and the like as by-products is increased. The amount of the elution of the antimony compound when used as such increases.

Here, examples of the antimony compound include antimony trioxide, antimony pentoxide, antimony acetate, methoxyantimony, triphenylantimony, antimony glycolate and the like.
Antimony trioxide is preferred.

The polycondensation is preferably carried out in the coexistence of a titanium compound. Accordingly, the polyester resin contains the titanium compound, the amount of the titanium compound used in the polycondensation, The content in the accompanying polyester resin is preferably 0.2 mol or less, more preferably 0.001 to 0.1 mol, as titanium atoms (Ti) per 1 ton of the polyester resin. When the content of the titanium compound is less than the above range, the degree of improvement in transparency as the polyester resin tends to decrease, while when the content exceeds the above range, the color tone tends to deteriorate.

Here, as the titanium compound,
For example, tetra-n-propyl titanate, tetra-i
-Propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate, titanium acetate, titanium oxalate, potassium titanium oxalate, titanium oxalate Sodium, potassium titanate, sodium titanate, titanic acid-aluminum hydroxide mixture,
Titanium chloride, titanium chloride-aluminum chloride mixture, titanium bromide, titanium fluoride, potassium hexafluorotitanate,
Cobalt hexafluorotitanate, manganese hexafluorotitanate, ammonium hexafluorotitanate, titanium acetylacetonate and the like, among which tetra-n-propyl titanate, tetra-i-propyl titanate, tetra-n -Butyl titanate, titanium oxalate and potassium potassium oxalate are preferred.

The polycondensation is carried out in view of its polycondensability, reduction of by-products such as cyclic trimers and acetaldehyde, and transparency and color tone of the resulting resin.
The compound is preferably made in the coexistence of a compound of an element of Group A or Group IIA, and a phosphorus compound.Accordingly, the polyester resin contains a compound of the element, and a phosphorus compound. The amount used in the polycondensation, and the content in the polyester resin accompanying the polycondensation, is preferably 0.4 to 8 mol per 1 ton of the polyester resin as the total (M) of the atoms of the compound of the element.
More preferably, it is 6 to 4 mol. Further, the amount of the phosphorus compound used in the polycondensation and the content in the resulting polyester resin are preferably 0.1 to 7 mol as phosphorus atoms (P) per 1 ton of the polyester resin,
More preferably, it is 0.3 to 4 mol.

The compounds of the Group IA or IIA elements of the periodic table include, for example, oxides, hydroxides, alkoxides, acetates, carbonates such as lithium, sodium, potassium, magnesium and calcium. Salts, oxalates, halides and the like, specifically, for example, lithium acetate, sodium acetate, potassium acetate, magnesium oxide, magnesium hydroxide, magnesium alkoxide, magnesium acetate, magnesium carbonate, calcium oxide, calcium hydroxide, acetic acid Calcium, calcium carbonate and the like. Among them, a magnesium compound is preferred.

Examples of the phosphorus compound include orthophosphoric acid, polyphosphoric acid, and trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, and the like.
Tricresyl phosphate, tris (triethylene glycol) phosphate, ethyl diethyl phosphonoacetate, methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, monobutyl phosphate, dibutyl phosphate, dioctyl phosphate, triethylene glycol acid phosphate And pentavalent phosphorus compounds such as phosphorous acid, hypophosphorous acid, and trivalent phosphorus compounds such as diethyl phosphite, trisdodecyl phosphite, trisnonyl decyl phosphite, and triphenyl phosphite. , Orthophosphoric acid, tris (triethylene glycol) phosphate, ethyl diethyl phosphonoacetate, ethyl acid phosphate, triethylene glycol acid Dohosufeto, phosphorous acid are preferred, tris (triethylene glycol) phosphate,
Ethyl diethyl phosphonoacetate, ethyl acid phosphate and triethylene glycol acid phosphate are particularly preferred.

In the present invention, at the time of polycondensation, a metal compound other than the above compounds may be present as long as the effects of the present invention are not impaired. Accordingly, the metal compound is contained in the polyester resin of the present invention. It may be contained. In that case, as the metal compound, aluminum,
Chrome, iron, cobalt, nickel, copper, zinc, germanium, zirconium, molybdenum, silver, tin, lanthanum,
Oxides of cerium, hafnium, tungsten, gold, etc.
Examples include compounds such as hydroxides, alkoxides, carbonates, phosphates, carboxylate salts, and halides.

The polyester resin in the present invention is basically produced by a conventional method for producing a polyester resin. That is, a dicarboxylic acid component mainly containing the terephthalic acid or its ester-forming derivative and a diol component mainly containing ethylene glycol,
In an esterification reaction tank, the esterification reaction is usually carried out under stirring at a temperature of about 240 to 280 ° C. under a pressure of about 0 to 4 × 10 ⁵ Pa for about 1 to 10 hours, or the presence of a transesterification catalyst. After the transesterification reaction, the resulting esterification reaction product or polyester low molecular weight product as a transesterification reaction product is transferred to a polycondensation tank, and in the presence of the compound, usually at about 250 to 290 ° C. Temperature, from normal pressure to gradually decompress
It is manufactured by melt polycondensation under stirring at a reduced pressure of about 13.3 Pa for about 1 to 20 hours, and these are performed in a continuous system or a batch system.

Usually, the resin obtained by melt polycondensation is drawn out in a strand form from a discharge port provided at the bottom of the polycondensation tank, and cut with a cutter with or after cooling with water, and is pelletized into a pellet form. It is a granular material such as a chip, and further, the granular material after the melt polycondensation is usually
Under an inert gas atmosphere such as nitrogen, carbon dioxide, and argon,
Or, in a steam atmosphere, or in a steam-containing inert gas atmosphere, usually at a temperature of about 60 to 180 ° C. to crystallize the surface of the resin granules, and then in an inert gas atmosphere, and / or Under a reduced pressure of about 13.3 Pa, usually at a temperature just below the adhesive temperature of the resin to 80 ° C. lower, while flowing the particles so as not to adhere to each other, the heat treatment is usually performed for about 50 hours or less, and the solid phase is solidified. Polycondensation is preferred, and the degree of polymerization can be further increased by this solid-phase polycondensation, and it is possible to reduce the amount of reaction trimer such as cyclic trimer and acetaldehyde.

Further, the resin obtained by the melt polycondensation or the solid phase polycondensation as described above has improved heat stability and reduced by-products such as cyclic trimers and acetaldehyde during molding. For the purpose, usually, a treatment such as a water treatment of dipping in warm water of 40 ° C. or more for 10 minutes or more, or a steam treatment of contacting with steam or a gas containing steam at 60 ° C. or more for 30 minutes or more may be performed.

The polyester resin in the polyester resin composition of the present invention has an intrinsic viscosity of 30 in a mixed solvent of phenol / tetrachloroethane (weight ratio 1/1).
It is essential that the value measured at ° C is 0.6 to 1.2 dl / g, preferably 0.7 to 1.0 dl / g. When the intrinsic viscosity is less than the above range, the mechanical strength as the polyester resin composition is insufficient, and it is difficult to perform uniform stretching in molding such as stretch blow molding. In molding such as stretch blow molding, problems such as breakage of the molded body due to blow pressure occur.

The polyester resin composition of the present invention comprises the polyester resin and a polyolefin resin or a polyamide resin, and it is essential that the latter polyolefin resin or polyamide resin be contained in an amount of 0.0001 to 1000 ppm. , 0.001-100pp
Preferably, it is contained in an amount of m. here,
When the content of the latter polyolefin resin or polyamide resin is less than the above range, the crystallization rate of the polyester resin composition is inferior, and as a result, the productivity of the bottle is inferior. Becomes

Here, as the polyolefin resin, for example, homopolymers of α-olefins having about 2 to 8 carbon atoms such as ethylene, propylene, butene-1, etc., and those α-olefins and ethylene, propylene , 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1
-Other α-olefins having about 2 to 20 carbon atoms, such as decene, and copolymers with vinyl compounds such as vinyl acetate, acrylic acid, methacrylic acid, acrylic acid esters, methacrylic acid esters, vinyl chloride, and styrene. Specific examples thereof include, for example, ethylene homopolymer, ethylene-propylene copolymer, ethylene-1-butene copolymer, and ethylene (low-, medium-, and high-density polyethylene) (branched or linear). 4-methyl-1-pentene copolymer, ethylene-
1-hexene copolymer, ethylene-1-octene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-ethyl acrylate copolymer, etc. Ethylene resin,
Propylene resins such as propylene homopolymer, propylene-ethylene copolymer, propylene-ethylene-1-butene copolymer, and 1-butene homopolymer, 1-butene-ethylene copolymer, 1-butene- Examples thereof include 1-butene resins such as propylene copolymer.

Examples of the polyamide resin include polymers of lactams such as butyrolactam, δ-valerolactam, ε-caprolactam, enantholactam, ω-lauryl lactam, 6-aminocaproic acid, 7-aminoheptanoic acid, and the like. Polymers of amino acids such as 8-aminooctanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, 1,4-butanediamine, 1,5-pentanediamine, 1,5-hexanediamine 1,6-hexanediamine, 1,9-nonanediamine, 1,11-undecadiamine, 1,12-dodecanediamine, aliphatic diamine such as α, ω-diaminopolypropylene glycol, 1,3- or 1,4 -Fats such as bis (aminomethyl) cyclohexane and bis (p-aminocyclohexylmethane) Cyclic diamines, diamines such as aromatic diamines such as m- or p-xylylenediamine, and aliphatic dicarboxylic acids such as glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, cyclohexanedicarboxylic acid, etc. Examples include polycondensates with dicarboxylic acids such as aromatic dicarboxylic acids such as alicyclic dicarboxylic acids, terephthalic acid, and isophthalic acid, and copolymers thereof, and specifically, for example, nylon 4, nylon 6 , Nylon 7, nylon 8, nylon 9, nylon 11, nylon 12, nylon 66, nylon 69, nylon 6
10, nylon 611, nylon 612, nylon 6
T, nylon 6I, nylon MXD6, nylon 6/6
6, nylon 6/610, nylon 6/12, nylon 6 / 6T, nylon 6I / 6T and the like.

In the present invention, in order to make the polyester resin contain the polyolefin resin or the polyamide resin, the polyester resin is directly added with the polyolefin resin or the polyamide resin so that the content is within the above range. In addition to a method of melt-kneading, or a method of melt-kneading by adding as a master batch, the polyolefin resin or the polyamide resin may be used in the step of producing the polyester resin, for example, during melt polycondensation (raw material, slurry, Catalyst, etc.), immediately after melt polycondensation,
Immediately after pre-crystallization, during solid phase polycondensation, immediately after solid phase polycondensation, etc., or during the period from the end of the production stage to the molding stage, is added directly as a powder or the like. Or, or by contacting the polyester resin chip with a liquid such as water dispersed as a powder, or by contacting the polyester resin chip with a gas such as air mixed as a powder, or It is also possible to employ a method in which the polyester resin chips are mixed under a flow condition of the polyester resin chip-like body by a method such as contact with a member of a polyolefin resin or a polyamide resin and then melt-kneaded.

Among these methods, as a method of adding a polyolefin resin or a polyamide resin as powders, there are the following methods.
At the time of pneumatic transportation to the pre-crystallization machine, or at the time of pneumatic transportation to the solid-phase polycondensation tank, or at the time of pneumatic transportation to the storage tank of the chip-like body after the solid-phase polycondensation, or to the molding machine In some cases, it is preferable to mix a powder of polyolefin resin or polyamide resin into the air for pneumatic transportation.

As a method of bringing a polyester resin chip into contact with a polyolefin resin or a polyamide resin member under flow conditions, a polyester resin chip is placed in a space where a member made of a polyolefin resin or a polyamide resin exists. Is preferably brought into collision contact with
Specifically, for example, immediately after the melt polycondensation of the polyester resin, immediately after pre-crystallization, during the production process such as immediately after solid-phase polycondensation,
In addition, pneumatic transport pipes, gravity transport pipes, silos, vibrating sieves, etc., when filling and discharging the transport container at the stage of transporting the polyester resin chip as a product, at the time of loading the molding machine at the polyester resin chip molding stage, etc. Punching plate, part of the magnet part of the magnet catcher, etc. are made of polyolefin resin or polyamide resin, or polyolefin resin or polyamide resin is lined, or polyolefin resin such as rod-like or net-like body in the transfer path Alternatively, there is a method of transferring a polyester resin chip by installing a member made of a polyamide resin. The contact time of the polyester resin chip with the member is usually very short, about 0.01 to 1 second, but a small amount of a polyolefin resin or a polyamide resin can be mixed into the polyester resin.

The polyester resin composition of the present invention has a crystallization temperature (T _c1 ) of 155 after forming into a molded article.
It is essential that the temperature drop crystallization temperature (T _c2 ) is not higher than 180 ° C. or not observed at 165 ° C., and the temperature rise crystallization temperature (T _c1 ) is preferably 157-164 ° C. The _formation temperature (T _c2 ) is preferably 178 ° C. or lower or is not observed. Here, when the temperature rise crystallization temperature (T _c1 ) is less than the above range, the transparency of the polyester resin composition is inferior. Is reduced, or the shape of the plug portion or the like due to the heat treatment is deteriorated. If the crystallization temperature (T _c2 ) exceeds the above range, the transparency of the polyester resin composition will be poor.

Here, the temperature rise crystallization temperature (T _c1 ) of the preform after injection molding at 280 ° C. after forming the molded product was determined by using a differential scanning calorimeter (“D” manufactured by Seiko Electronics Co., Ltd.).
SC220C ”) in a nitrogen stream at 20 ° C. to 285
The temperature was raised to 20 ° C. at a rate of 20 ° C./min, and the top temperature of the crystallization exothermic peak observed on the way was measured. The falling crystallization temperature (T _c2 ) was 20 ° C. to 285 ° C. The temperature was raised at a rate of ° C / min, the molten state was maintained at 285 ° C for 5 minutes, and then the temperature was lowered to 20 ° C at a rate of 10 ° C / min. It is.

Further, the polyester resin composition of the present invention comprises:
From the viewpoint of mold contamination resistance during molding, the cyclic trimer content (CT ₀ ) is preferably 0.45% by weight or less,
In addition, from the viewpoint of reducing the flavor and the like of the content of food and drink when used as a bottle or the like, the acetaldehyde content (AA ₀ ) is preferably 10 ppm or less. It is preferable that the color coordinate b of the Hunter's color difference formula in the Lab color system described in Reference 1 of JIS Z8730 is 4 or less. The cyclic trimer content (CT ₀ ) is more preferably 0.40% by weight or less, and the acetaldehyde content (AA ₀ ) is 5 ppm.
The color coordinate b of the Hunter's color difference formula is more preferably 3 or less.

Further, the polyester resin composition of the present invention comprises
Injection molding at 280 ° C from the viewpoint of mold contamination resistance during molding
Cyclic trimer content (CT_S;weight
%) And the cyclic trimer content before injection molding (CT₀;weight
%) (CT)_S-CT₀) Is less than 0.15% by weight
And preferably 0.10% by weight or less.
preferable. Contents when used as bottles, etc.
After injection molding at 280 ° C
Acetaldehyde content (AA _SPp
m) and the acetaldehyde content before injection molding (A
A₀; Ppm)_S-AA₀) Is 20 ppm
And preferably 15 ppm or less.
Preferred.

In the present invention, an antioxidant, an ultraviolet absorber,
Light stabilizer, antistatic agent, lubricant, antiblocking agent, antifogging agent, nucleating agent, plasticizer, coloring agent, dispersant, infrared absorber,
An additive such as a filler may be contained.

The polyester resin composition of the present invention is prepared by melt-kneading the polyester resin and the polyolefin resin or the polyamide resin together with the additives used as necessary according to a conventional method. Then, for example, after being molded into a preform by injection molding, it is useful for molding an injection blow molded body in which a bottle or the like is biaxially stretched and stretch blow molded in a blow molding mold to form a bottle or the like. It is particularly preferably used in forming a heat-resistant bottle by heating the plug portion of a preform or a bottle with an infrared heater or the like. The injection molding conditions at that time are within the range usually employed, for example, a cylinder temperature of 260 to 300 ° C., a screw rotation speed of 40 to 300 rpm, and an injection pressure of 4 × 10 ^6.
~ 14 × 10 ⁶ Pa, mold temperature around 5-40 ° C,
The stretch blow molding conditions include a stretching temperature of 70 to 12
At 0 ° C., the stretching ratio is about 1.5 to 3.5 times in the longitudinal direction and about 2 to 5 times in the circumferential direction, and heat fixing is performed at a temperature of 100 to 200 ° C. for several seconds to several minutes.

The polyester resin composition of the present invention is obtained by a blow molding method such as a cold parison method in which a preform obtained by an injection molding method is biaxially stretched after reheating in a molded article obtained by the above molding method. Suitable as injection blow bottles molded into bottles, for example, as bottles for liquid seasonings such as carbonated drinks, alcoholic drinks, soy sauce, sauces, mirin, dressings, etc., and further, fruit juice drinks, tea and mineral water, etc. It is suitably used as a heat-resistant bottle for beverages and the like.

Further, the polyester resin composition of the present invention is formed into an injection blow bottle having a specific surface area of 0.6 to 0.8 cm ^-1 , and is filled with hot water at 93 ° C. to form an antimony compound. The elution amount is 1.0 ppb or less as the concentration of antimony atom (Sb) in water, which means that the antimony compound has extremely excellent elution resistance.
Here, the specific surface area of the bottle is a value obtained by dividing the surface area inside the bottle by the volume of the bottle.

[0039]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Example 1 40 kg of terephthalic acid and ethylene glycol 1
About 50 kg of bis (2-hydroxyethyl) terephthalate was previously charged to 6.1 kg of slurry, and the temperature was 25%.
The mixture was sequentially supplied to the esterification reaction tank maintained at 0 ° C. and a pressure of 1.2 × 10 ⁵ Pa over 4 hours.
The esterification reaction was performed over time, and 50 kg of the esterification reaction product was transferred to a polycondensation tank.

Then, an ethylene glycol solution of ethyl acid phosphate, a water / ethylene glycol solution of magnesium acetate and antimony trioxide, and a tetra-n- An ethylene glycol solution of butoxytitanium was prepared by adding 0.420 mol of phosphorus atom (P), 0.700 mol of magnesium atom (Mg), and 0.9 mol of antimony atom (Sb) per ton of polyester resin.
After 86 moles and 0.021 moles of titanium atoms (Ti) were sequentially added at 5 minute intervals, 582 g of diethylene glycol and low-density polyethylene resin ("UE320" manufactured by Nippon Polychem Co., Ltd.) were further added. It was added so as to be 0.040 ppm based on the weight of the polyester resin. Thereafter, the inside of the system was heated at 250 ° C. for 2 hours and 30 minutes.
And 280 ° C., while reducing the pressure from normal pressure to 400 Pa over 1 hour and maintaining the same pressure, and performing a melt polycondensation for a period of time such that the intrinsic viscosity of the obtained resin becomes 0.62 dl / g. About 40 kg of a polyethylene terephthalate resin (copolymerization amount of diethylene glycol: 3.4 mol%) was produced by extracting a strand from an extraction port provided at the bottom of the tank, cooling with water, and chipping with a cutter.

Subsequently, the polyester resin chips obtained above were continuously fed into a stirring crystallization machine (manufactured by Bepex) maintained at about 160 ° C. so that the residence time was about 5 minutes. Crystallized and inert oven (ES
After drying at 160 ° C. for 4 hours under a nitrogen stream of 40 L / min in “IPHH-201 type” manufactured by PEC,
Solid phase polycondensation was performed by heating at 10 ° C. for a time at which the intrinsic viscosity became 0.839 dl / g.

The resulting polyester resin composition chips were subjected to the following method to determine the proportion of ethylene terephthalate units in the polyester resin, the metal atom content in each metal compound, the intrinsic viscosity, and the polyester resin composition. The acetaldehyde content and the color coordinate b as a color tone were measured, and the results are shown in Table 1.

Ethylene tereph in polyester resin
Using the ratio resin samples tallates units in deuterated trifluoroacetic acid 3 wt% solution prepared by dissolving at room temperature, measured IH-NMR in a nuclear magnetic resonance apparatus (manufactured by JEOL Ltd. "JNM-EX270 model") Then, the peaks were assigned, and a dicarboxylic acid component other than terephthalic acid and a diol component other than ethylene glycol were calculated from the integral ratio to obtain the ratio of ethylene terephthalate units.

2.5 g of a resin sample containing a metal atom was ashed by a conventional method in the presence of sulfuric acid, completely decomposed, and the volume was adjusted to 50 ml with distilled water.

[0046]Intrinsic viscosity ([η]) 0.50 g of the freeze-ground resin sample was added to phenol / tetra
In a mixed solvent of lachloroethane (weight ratio 1/1), the concentration
(C) at 1.0 g / dl, at 110 ° C. for 20 minutes
After dissolving, 30 minutes using an Ubbelohde type capillary viscous tube.
° C, relative viscosity with the stock solution (η_rel) Measure this relative
Viscosity (η_rel) -1 specific viscosity (η _sp) And concentration
(C) ratio (η_sp/ C), and the density (c)
0.5g / dl, 0.2g / dl, 0.1g / dl
The ratio (η_sp/ C)
From these values, the ratio (η) when the concentration (c) is extrapolated to 0
_sp/ C) was determined as the intrinsic viscosity [η] (dl / g).

A cyclic trimer content (CT ₀ ) resin sample ( 4.0 mg ) was precisely weighed, and a mixed solvent of chloroform / hexafluoroisopropanol (volume ratio: 3/2) was used.
After dissolving in 10 ml, further diluted with 20 ml of chloroform, and precipitated by adding 10 ml of methanol.
Subsequently, the filtrate obtained by filtration is evaporated to dryness, then dissolved in 25 ml of dimethylformamide, and the amount of cyclic trimer (cyclotriethylene terephthalate) in the solution is determined by liquid chromatography (“LC-10A” manufactured by Shimadzu Corporation). ).

An acetaldehyde content (AA ₀ ) resin sample ( 5.0 g ) was precisely weighed, sealed in a 50 ml inner volume microbomb with 10 ml of pure water under a nitrogen seal, and
Heat extraction was performed at 0 ° C. for 2 hours, and the amount of acetaldehyde in the extract was determined by gas chromatography using isobutyl alcohol as an internal standard (“GC-14 manufactured by Shimadzu Corporation”).
A)).

The color tone resin sample was filled into a cylindrical powder colorimetric cell having an inner diameter of 36 mm and a depth of 15 mm by scribing, and was measured using a colorimetric colorimeter (“ND-300A” manufactured by Nippon Denshoku Industries Co., Ltd.). , JIS Z
The color coordinates b of the color difference formula of the Hunter in the Lab color system described in Reference 1 of 8730 were obtained as a simple average value of the values measured at four points by rotating the cell by 90 degrees by the reflection method.

Further, the obtained polyester resin composition chips were placed in an inert oven ("IPHH-" manufactured by ESPEC Corporation).
201 ”) under a nitrogen flow of 40 l / min.
After drying at 0 ° C. for 4 hours, the cylinder temperature was 2 using an injection molding machine (“M-70AII-DM” manufactured by Meiki Seisakusho Co., Ltd.).
At 80 ° C., back pressure 5 × 10 ⁵ Pa, injection rate 40 cc / sec, holding pressure 35 × 10 ⁵ Pa, mold temperature 25 ° C., molding cycle about 75 seconds, the shape shown in FIG. 1
Injection molding was performed on a stepped plate having a thickness of 6 mm with a thickness of 0.5 mm and a height difference of 6 mm to 3.5 mm in a horizontal direction (G in FIG. 1 indicates a gate portion).
With respect to the obtained molded plate, the cyclic trimer content, acetaldehyde content, elevated crystallization temperature and decreased crystallization temperature, and haze as transparency were measured by the following method, and the results were shown in Table 1. Indicated.

[0051] Using samples cut out from the (A portion in FIG. 1) the tip portion of the thickness 3.5mm portion of the cyclic trimer content (CT _S) molded plate were measured in the same manner as described above.

Acetaldehyde Content (AA _S ) A sample was cut out from a rear end portion (a portion B in FIG. 1) of a 3.5 mm-thick part (part B in FIG. 1) into a chip of about 4 mm square, and the chip was measured in the same manner as described above.

Temperature rise crystallization temperature (T _C1 ) and temperature fall crystallization temperature
(T _C2 ) A sample cut out from the non-surface part after cutting out a 3.5 mm thick tip part (part A in FIG. 1 ) of a molded plate, drying it at 40 ° C. for 3 days with a vacuum dryer. Approximately 10 mg of the mixture was precisely weighed, and an aluminum open pan and pan cover (normal pressure type, “P / N SSC000E030” and “P / N SS” manufactured by Seiko Electronics Co., Ltd.) were used.
C000E032 ”), and the temperature was increased from 20 ° C. to 285 ° C. at a rate of 20 ° C./min. Under a nitrogen stream using a differential scanning calorimeter (“ DSC220C ”manufactured by Seiko), and observed during the course. The peak temperature of the exothermic crystallization to be measured was measured and defined as an elevated crystallization temperature (T _C1 ). 285
After maintaining the molten state at 5 ° C. for 5 minutes, the temperature was lowered to 20 ° C. at a rate of 10 ° C./min, and the crystallization exothermic peak temperature observed on the way was measured to obtain the temperature-reducing crystallization temperature (T _C2 ).

The thickness of the transparent molded plate is 5.0 mm (C in FIG. 1).
About the haze meter ("NDH" manufactured by Nippon Denshoku Industries Co., Ltd.)
−300 A ”).

Further, the obtained polyester resin composition chips were dried in a vacuum dryer at 130 ° C. for 10 hours, and then subjected to an injection molding machine (“FE-80S” manufactured by Nissei Plastics Industry Co., Ltd.).
, Cylinder temperature 280 ° C, back pressure 5 × 10 ⁵ Pa,
Injection rate 45 cc / sec, holding pressure 30 × 10 ⁵ Pa, mold temperature 20 ° C., molding cycle about 40 seconds, outer diameter about 29 mm,
Height about 165mm, average thickness about 3.7mm, weight about 60
g of the test specimen was injection molded. After heating the plug part of the obtained preform by a quartz heater type plug part crystallizer for 150 to 180 seconds,
The plug was crystallized by inserting a mold pin, and the shape and dimensions of the plug were visually observed and evaluated according to the following criteria. The results are shown in Table 1.

Plug shape and size 口 : Stable dimensional accuracy is obtained. X: Insufficient crystallization and buckling in shape.

Next, the preform having the plug portion crystallized is placed in a near-infrared irradiation furnace equipped with a quartz heater.
After heating for 0 second and leaving at room temperature for 25 seconds, it was charged into a blow mold set at 160 ° C., and stretched in the height direction with a stretching rod, and at a blow pressure of 7 × 10 ⁵ Pa for 1 second,
Furthermore, by blow molding at 30 × 10 ⁵ Pa for 40 seconds, heat setting and air cooling, the outer diameter is about 95 mm, the height is about 305 mm, the average body thickness is about 0.37 mm, and the weight is about 6 mm.
0 g, internal volume about 1.5 liter, specific surface area about 0.7 cm
^-1 bottles were molded. The external appearance of the obtained bottle was visually observed and evaluated according to the following criteria. Further, the amount of hot water eluted by the antimony compound was measured by the following method, and the results are shown in Table 1.

[0058] bottle appearance ◎; excellent transparency, good as a whole. ；: Good transparency, good overall. ×: Darkening or whitening occurred, and transparency was poor.

A bottle of hot water eluted with an antimony compound was filled with about 1.5 liters of distilled water at 93 ° C., allowed to cool at room temperature, and then inductively coupled plasma mass spectrometer (“HP4500” manufactured by Hewlett-Packard Company) was used. hand,
The elution amount of the antimony compound in water was measured as an antimony atom (Sb) concentration.

Examples 2 to 3 A polyester resin composition was prepared in the same manner as in Example 1 except that the amounts of ethyl acid phosphate and antimony trioxide added during the melt polycondensation were changed. , Ethylene terephthalate unit ratio, metal atom content, intrinsic viscosity, and cyclic trimer content, acetaldehyde content, and color tone as a polyester resin composition, and injection molding of a stepped molding plate Then, measure the cyclic trimer content, acetaldehyde content, temperature-rise crystallization temperature and temperature-fall crystallization temperature, and transparency, and further perform injection blow molding of the bottle, and evaluate the shape of the plug and the appearance of the bottle And the amount of antimony eluted were measured, and the results are shown in Table 1.

Example 4 Except that the amounts of ethyl acid phosphate, magnesium acetate and antimony trioxide added during the melt polycondensation were changed, and that tetra-n-butoxytitanium was not added, A polyester resin composition was produced in the same manner as in Example 1, and the proportion of ethylene terephthalate units, the content of metal atoms, the intrinsic viscosity, and the content of the cyclic trimer as the polyester resin composition, acetaldehyde as the polyester resin. Measure the content, and color tone, and also injection-mold the stepped plate, measure the cyclic trimer content, acetaldehyde content, heated crystallization temperature and cooled crystallization temperature, and transparency, furthermore , Injection blow molding the bottle, evaluating the plug shape and the bottle appearance,
The elution amount of antimony was measured, and the results are shown in Table 1.

Example 5 A polyester resin composition was obtained in the same manner as in Example 4 except that the solid-phase polycondensation polyester resin obtained in Example 4 was further immersed in distilled water at 95 ° C. for 4 hours and treated with water. The product is manufactured, as a polyester resin, the ratio of ethylene terephthalate units, metal atom content, intrinsic viscosity, and, as the polyester resin composition, cyclic trimer content, acetaldehyde content, and color tone are measured, Also, the stepped plate is injection-molded, and the cyclic trimer content, acetaldehyde content, heated crystallization temperature and cooled crystallization temperature, and transparency are measured. The stopper shape and the bottle appearance were evaluated, and the amount of antimony eluted was measured. The results are shown in Table 1.

Comparative Example 1 Normal phosphoric acid was used as a phosphorus compound during melt polycondensation.
That the amounts of orthophosphoric acid, antimony trioxide, and magnesium acetate were changed, and that tetra-n-butoxytitanium was not added, and that diethylene glycol and low-density polyethylene resin were not added,
Other than the above, a polyester resin composition was produced in the same manner as in Example 1, and the ratio of ethylene terephthalate units, the content of metal atoms, the intrinsic viscosity, and the cyclic trimethylene as a polyester resin composition were determined. Measuring the monomer content, acetaldehyde content, and color tone,
Also, the stepped plate is injection-molded, and the cyclic trimer content, acetaldehyde content, heated crystallization temperature and cooled crystallization temperature, and transparency are measured. The stopper shape and the bottle appearance were evaluated, and the amount of antimony eluted was measured. The results are shown in Table 1.

Comparative Examples 2 to 4 A polyester resin composition was prepared in the same manner as in Examples 1 to 3, except that the low-density polyethylene resin was not added during the melt polycondensation. , Metal atom content, intrinsic viscosity, and cyclic trimer content, acetaldehyde content, and color tone of the polyester resin composition were measured. Monomer content,
Measure the acetaldehyde content, the heating crystallization temperature and the cooling crystallization temperature, and the transparency.Furthermore, injection blow molding the bottle, evaluate the plug shape and the bottle appearance, measure the antimony elution amount, and Are shown in Table 1.

Comparative Example 5 A polyester resin composition was prepared in the same manner as in Example 1 except that a low-density polyethylene resin was added at 1500 ppm based on the weight of the polyester resin during the melt polycondensation. As, the proportion of ethylene terephthalate units, metal atom content, intrinsic viscosity, and, as the polyester resin composition, cyclic trimer content, acetaldehyde content, and color tone,
Also, the stepped plate is injection-molded, and the cyclic trimer content, acetaldehyde content, heated crystallization temperature and cooled crystallization temperature, and transparency are measured. The stopper shape and the bottle appearance were evaluated, and the amount of antimony eluted was measured. The results are shown in Table 1.

[0066]

[Table 1]

[0067]

According to the present invention, a polyester resin composition which can efficiently impart heat resistance to a molded article by heat treatment without reducing transparency, and is particularly useful for molding an injection blow bottle, and Injection blow bottles can be provided.

[Brief description of the drawings]

FIG. 1A is a plan view and FIG. 1B is a front view of a stepped plate for evaluating physical properties formed in Examples.

Continued on the front page (72) Inventor Masahiro Nukii 1 Tohocho, Yokkaichi-shi, Mie F-term in Yokkaichi Office of Mitsubishi Chemical Corporation (reference) 3E033 AA01 BA14 BA18 BA21 BB02 CA07 CA18 FA02 FA03 GA02 4F071 AA15 AA20 AA21 AA44 AA46 AA54 AA89 AB11 AC05 AC09 AE07 AF30 AH05 BB05 BB07 BB13 BC04 4J002 BB022 BB052 BB062 BB072 BB082 BB112 BB162 BB172 CF011 CF031 CF041 CF061 CF081 CF141 CL012 CL032 CL052 DD028 DD037 DD077 DE087 DE058 DE088 FD208 FD209 GG01

Claims (6)

[Claims] 1. An ethylene terephthalate unit as a main constitutional repeating unit, an antimony compound as 0.08 to 2 mol / ton as antimony atom (Sb), and a titanium compound as 0 to 0.2 mol as titanium atom (Ti). /
Tons, each containing 0.6-1.2 dl intrinsic viscosity
/ G polyester resin, 0.0001-1000p
pm, which is a resin composition comprising a polyolefin resin or a polyamide resin contained in an amount of pm, and has a crystallization temperature (T _c1 ) of 155 to 165 ° C. and a crystallization temperature (T _c ) _c2 ) is 180 ° C. or lower or is not observed. 2. The polyester resin further comprises, in addition to the antimony compound and the titanium compound, a compound of an element of Group IA or Group IIA of the periodic table as a sum of their atoms (M).
The polyester resin composition according to claim 1, which contains 0.4 to 8 mol / ton as a phosphorus compound and 0.1 to 7 mol / ton as a phosphorus atom (P), respectively. 3. The cyclic trimer content (CT ₀ ) is 0.45
Wt% or less, and the acetaldehyde content (AA ₀ ) is 10
3. The polyester resin composition according to claim 1, wherein the color coordinate b is 4 or less, and the color coordinate b of the color difference formula of the Hunter is 4 or less. 4. 4. The content of the cyclic trimer (CT _S ; wt%) in the molded body after injection molding at 280 ° C. and the cyclic trimer content (CT ₀ ; wt%) before injection molding. Difference (CT _S
-CT ₀ ) is 0.15% by weight or less, and the acetaldehyde content (AA _S ; ppm) and the acetaldehyde content (AA ₀ ; ppm) in the molded article after injection molding at 280 ° C. difference (AA _S -AA ₀₎ is a polyester resin composition according to any one of claims 1 to 3 is 20ppm or less. 5. An injection blow bottle having a specific surface area of 0.6 to 0.8 cm ^-1 is formed, and when the bottle is filled with hot water of 93 ° C., the elution amount of the antimony compound is determined by the amount of antimony atoms in water ( The polyester resin composition according to any one of claims 1 to 4, wherein the concentration of Sb) is 1.0 ppb or less. 6. An injection blow bottle comprising the polyester resin composition according to any one of claims 1 to 5.