JPH1053696A - Thermoplastic polyester resin hollow molded container and method for producing the same - Google Patents

Abstract

(57) [Problem] To provide a thermoplastic polyester resin hollow molded container excellent in ultraviolet shielding property and a method for producing the same. SOLUTION: At least one kind of naphthalenedicarboxylic acid, its ester, or its imide is used in an amount of 0.001 part by weight or more per 100 parts by weight of a thermoplastic polyester resin.
A thermoplastic polyester resin hollow molded container comprising a resin composition added in an amount of 10 parts by weight or less. as well as,
A method for producing a thermoplastic polyester resin hollow molded container, comprising injection molding the thermoplastic polyester resin composition to form a preform, and then blowing the preform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow container made of thermoplastic polyester resin and a method for producing the same. More particularly, the present invention relates to a thermoplastic polyester resin hollow molded container having excellent ultraviolet blocking properties and a method for producing the same.

[0002]

2. Description of the Related Art Thermoplastic polyester resins represented by polyethylene terephthalate have been widely used for fibers and films due to their excellent mechanical properties and chemical properties. Due to their properties, safety and health, etc., their suitability as carbonated drinks, fruit juice drinks, liquid seasonings, edible oils, and containers for alcohol and wine has attracted attention.

[0003]

However, these polyester resin containers are excellent in blocking ultraviolet rays on the short wavelength side up to about 300 nm, however, ultraviolet rays and visible light on the longer wavelength side are more excellent. Almost pass. In such a polyester resin container, for example, edible oil, mirin, filling with a liquid seasoning such as dressing,
After a storage period of several months, although there are special characteristics depending on the filled food and storage conditions, deterioration of the contents, for example, delicate changes in color, taste, aroma often occur gradually . The deterioration of the contents is caused by external factors such as oxygen, heat, light, especially ultraviolet rays, and microorganisms. In the case of a polyester resin container, the oxygen barrier properties are relatively excellent. Deterioration of the contents can be largely prevented even below.

At present, ultraviolet absorbers and the like are generally used in the industry for the purpose. However, these ultraviolet absorbers are generally expensive, and the application step is complicated, and these compounds are
In general, sublimability is large and thermal stability is often inferior, so that a problem often arises during the application step or molding process. Also, when used in food containers, the added UV absorber may migrate to the contents,
Not necessarily preferred.

[0005]

Means for Solving the Problems The present inventors have made intensive studies on a polyester resin container meeting the above-mentioned object, and as a result, it has been found that even if a UV absorber generally used in the relevant industry at present is not added, it is excellent. The present inventors have found a polyester resin container exhibiting an ultraviolet blocking effect, and have reached the present invention. That is, the present invention relates to the following chemical structural formula per 100 parts by weight of a thermoplastic polyester resin.

[0006]

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(Wherein R ¹ and R ² may be the same or different and represent a hydrogen atom or an optionally substituted alkyl, alkenyl, aryl, aralkyl or alkylaralkyl group) and , The following chemical structural formula

[0008]

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Wherein X is NR ³ , and R ³ is a carboxyl group or an alkyl or aryl group substituted with a hydroxyl group. Also, —C (＝ O) —X—
The C (ＯO)-imide group is a 1,2-position of a naphthalene ring;
A ring is formed at any of the 1,8 and 2,3 positions. A) a thermoplastic polyester resin hollow molded container comprising a resin composition in which at least one of naphthalenedicarboxylic acid and its derivative represented by the formula (1) is added in an amount of 0.001 to 10 parts by weight, A method for producing a thermoplastic polyester resin hollow molded container, comprising injection molding the thermoplastic polyester resin composition to form a preform, and then blowing the preform.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, naphthalenedicarboxylic acid, its ester or imide is used as a raw material. As naphthalenedicarboxylic acid and its ester, the following chemical structural formula

[0011]

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(Wherein R ¹ and R ² may be the same or different and represent a hydrogen atom or an optionally substituted alkyl, alkenyl, aryl, aralkyl or alkylaralkyl group). For example, 2,6-, 2,7-, 2,3-, 1,8-, 1,7-,
Structural isomers such as 1,6-, 1,5-, 1,4-, 1,3-, and 1,2-naphthalenedicarboxylic acid are exemplified, and preferable examples of naphthalenedicarboxylic acid esters include methyl, ethyl, Propyl and butyl esters. Further, as the imide compound, the following chemical structural formula

[0013]

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(Wherein X is NR ³ , and R ³ is a carboxyl group or an alkyl or aryl group substituted with a hydroxyl group. Also, —C (＝ O) —X—
The C (ＯO)-imide group is a 1,2-position of a naphthalene ring;
A ring is formed at any of the 1,8 and 2,3 positions. ) Can be used as long as it is an imide of naphthalenedicarboxylic acid represented by the formula (1), specifically, 1,8-naphthalenedicarboxylic acid-N- (α-carboxymethyl) imide,
(Β-carboxyethyl) imide,-(o- (m- or p-) carboxyphenyl) imide,-(α-hydroxymethyl) imide and the like. These naphthalenedicarboxylic acid imides include, for example, naphthalenedicarboxylic acid or a derivative thereof, glycine, alanine, valine, leucine, aliphatic aminocarboxylic acids such as ε-aminocaproic acid, amino alcohols such as ethanolamine, o-, It can be produced by reaction with aromatic aminocarboxylic acids such as m- or p-aminobenzoic acid.

The amount of the naphthalenedicarboxylic acid, ester or imide added is 0.001 part by weight or more per 100 parts by weight of the thermoplastic polyester resin.
0 parts by weight or less, preferably 5 parts by weight or less, more preferably 2 parts by weight or less. When the amount is less than 0.001 part by weight, a sufficient ultraviolet ray blocking effect cannot be obtained,
It is not preferable to add more than 0 parts by weight because the original properties of the homopolyester resin are lost.

These compounds having a naphthalenedicarboxylic acid skeleton may be added at any stage during the production of the polyester resin, and those added at any stage before the molding process also exhibit the ultraviolet ray blocking effect. That is, it may be added at any stage until the completion of the molding of the polyester resin, for example, before the start of the polycondensation reaction, during the polycondensation reaction, after the end of the polycondensation reaction, in the state of powder and granules, at the molding stage, and the like.

The thermoplastic polyester resin in the present invention includes aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, diphenyl ether dicarboxylic acid and diphenyl sulfone dicarboxylic acid, and ester-formed products thereof, hexahydroterephthalic acid and the like. An alicyclic dicarboxylic acid and an ester-form thereof, which are nuclei hydrogenated compounds of the aromatic dicarboxylic acid, succinic acid, adipic acid, sebacic acid,
Aliphatic dicarboxylic acids such as azelaic acid and its ester-forming products, fumaric acid, one or more dicarboxylic acid components of unsaturated dicarboxylic acids such as 4-carboxycinnamic acid and its ester-forming products, and ethylene glycol as a main component. Is a polyester resin obtained from the glycol, especially polyethylene terephthalate as the main target,
These polyester resins may contain 20 mol% or less of the above dicarboxylic acids as the third component. Also,
As the glycol component, other than ethylene glycol, other than ethylene glycol, aliphatic glycols such as diethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol, alicyclic glycols such as cyclohexanedimethanol, and 2,2-bis-
(4′-β-hydroxyethoxyphenyl) propane,
Bisphenol derivatives such as bis- (4′-β-hydroxyethoxyphenyl) sulfone, and the general formula-[-
(—CH ₂ —) _n —O—] _m — (where n is 1 ≦ n ≦ 6
And m is an integer of m ≧ 4), which may be obtained by copolymerizing polyethylene glycol, polytetramethylene glycol, or the like represented by 20 mol% or less of the total glycol component, and an oxyacid component such as hydroxybenzoic acid. May be used as a polyester resin. Also, as long as the polyester resin maintains substantially linear, pentaerythritol, trimethylolpropane, trimellitic acid,
A trifunctional or higher polyfunctional compound such as trimesic acid or pyromellitic acid or a monofunctional compound such as o-benzoylbenzoic acid may be copolymerized. In addition, other thermoplastic resins such as polybutylene terephthalate, polyethylene naphthalate, polyester elastomer, and polycarbonate may be blended in addition to the polyester resin described above.

The polyester resin used in the present invention preferably has an intrinsic viscosity of 0.5 or more, more preferably 0.6 or more. The viscosity of the polyester resin is important in manufacturing a hollow molded container, particularly in relation to a molding method. In particular, when a substantially non-oriented hollow molded container is obtained by extrusion blow molding, it is necessary to maintain the fluidity of the molten polyester resin at a certain level or more, depending on the capacity of the hollow molded container, in order to prevent drawdown. In general, a polyester resin having an intrinsic viscosity of 0.7 or more, preferably 0.8 or more is used. In the stretch blow molding, it is also possible to use a polymer having a relatively low viscosity as compared with the case of the extrusion blow molding method. Generally, a polymer having an intrinsic viscosity of 0.5 or more, preferably 0.6 or more is used. However, depending on the required physical properties of the molded article, a polyester resin having a higher viscosity is also used.

Further, in the present invention, conventionally known additives such as a stabilizer, a release agent,
A colorant such as an antistatic agent, a dispersant, and a dye or pigment may be added at any stage during the production of the polyester resin, or may be added by a so-called masterbatch formulation before molding.

Preferred dyes and pigments in the present invention are mainly titanium oxide, carbon black, phthalocyanine blue, phthalocyanine green, ultramarine, cobalt blue, titanium yellow, red iron oxide, baked amber, yellow iron oxide, and polycyclic. Heat-resistant oil-soluble dyes, specifically, oil-soluble dyes having a skeleton such as perinone-based, quinophthalone-based, anthrapyridone-based, and anthraquinone-based dyes. Those having a structure that binds to are particularly preferred. Furthermore, the dye / pigment must have good compatibility with the polyester resin, and exhibit sufficient heat stability and color tone stability even at the production and processing temperatures of the polyester resin. When used as a packaging container, a material that does not cause any problem in safety and health is selected and added.

In the present invention, the polyester resin composition comprises:
It may be molded as it is, and if necessary, furthermore, perform solid-state polymerization under high vacuum or under the flow of an inert gas to increase the degree of polymerization, lower aldehyde, lower oligomer, or form. It may be used after post-treatment such as solvent extraction with xylene or chloroform.

Further, after forming a so-called masterbatch, which is colored to a desired color having a high density several times to 100 times the predetermined density, practically up to about 50 times, and then coloring it into a non-colored or other color tone, The polyester resin may be diluted with the polyester resin thus obtained, or a new color tone may be newly developed to finally obtain a desired color tone before being subjected to molding.

In the present invention, the polyester resin composition comprises:
The container is formed by melting and blow molding, and in this case, all blow molding methods generally used in polyester resin molding can be applied. Specifically, for example, in order to obtain a hollow molded container, a normal extrusion blow method, an injection blow method, or a blow molding method such as a cold parison method in which a preform is molded, reheated, and then biaxially stretched is applied. However, the hollow molded container obtained by these molding methods is excellent in ultraviolet blocking property, gas blocking property, toughness and chemical resistance, and has high-grade glass-like transparency, soy sauce, It is particularly suitable as a seasoning such as sauce, mirin and dressing, edible oil, carbonated drink, fruit drink, liquor, wine and other food containers, and cosmetics and medicine containers.

[0024]

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. In the examples, "parts" means "parts by weight", and various measurement methods used in the examples are shown below.・ Intrinsic viscosity phenol-tetrachloroethane (50/50 weight ratio)
It was measured at 30 ° C. and a concentration of 1.0 g / dl. -Ultraviolet transmittance The transmittance was measured by a conventional method using a Hitachi Spectrum Photometer Model 340. -Acetaldehyde amount After extraction with water at 160 ° C for 2 hours, the amount was determined by high-sensitivity gas chromatography. -Inert gas flow rate The amount of gas circulated per unit time (hr) and per unit resin weight (kg) was shown as a volume (liter) converted to 1 atm and 25 ° C.

Example 1 Bis- (β-hydroxyethyl) terephthalate 20,
000 parts, 2 parts of germanium dioxide, 2 parts of orthophosphoric acid,
And 100 parts of 2,6-naphthalenedicarboxylic acid,
The temperature in the polymerization vessel was gradually raised from 260 ° C., and the pressure inside the polymerization vessel was gradually reduced from normal pressure. A transparent polyester resin having an intrinsic viscosity of 0.60 was obtained at 280 ° C., 1 torr and a total polymerization time of 2.5 hours. This chip of polyester resin is crystallized at a resin temperature of 150 ° C. in a solid air (trade name, manufactured by Bepex, Inc.) stirring crystallization machine, and then transferred to a stationary solid-state polymerization tower, where nitrogen of 30 l / kg · hr is added. Solid phase polymerization was performed at a resin temperature of 210 ° C. for 10 hours under a gas flow. The intrinsic viscosity of the solid-phase polymerized product is 0.76, and 3.0p is contained in the chip material.
pm of acetaldehyde. From this polyester resin, an injection molding machine IS-60 manufactured by Toshiba Corp. was set at 275 ° C. of each cylinder and a nozzle, at a screw rotation speed of 100 rpm, an injection time of 10 seconds, and a mold cooling water temperature of 10.
B was used to form a preform. The preform was blow-molded with a BMB-3 type machine manufactured by Corpoplast Co., Ltd., which was set at a preheating furnace of 90 ° C., a blow pressure of 20 kg / cm ² , and a molding cycle of 10 seconds, to obtain a bottle having an internal volume of 1 liter. The light transmittance at 360 nm of the 350 μm thick portion of the bottle body was 0.1%.

Example 2 Instead of 2,6-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid-N- (α-carboxymethyl)
Polymerization was carried out in the same manner as in Example 1 except that 60 parts of imide was added to obtain a transparent polyester resin having an intrinsic viscosity of 0.67. This polyester resin chip was subjected to solid phase polymerization treatment and bottle molding in the same manner as in Example 1 to obtain a bottle having an internal volume of 1 liter. 370n of 350μ thick part of this bottle body
The light transmittance at m was 1.7%.

Example 3 Polymerization was carried out in the same manner as in Example 1 except that 1.4 parts of copper phthalocyanine and 2 parts of a quinophthalone-based reactive dye (manufactured by Mitsubishi Kasei Kogyo KK) were added. 60 transparent polyester resins colored green were obtained. This polyester resin chip was subjected to solid phase polymerization treatment and bottle molding in the same manner as in Example 1 to obtain a bottle having an internal volume of 1 liter. The light transmittance at 360 nm of the 350 μm thick portion of the bottle body was 0.1%.

Comparative Example 1 Bis- (β-hydroxyethyl) terephthalate 20,
Only 2 parts of germanium dioxide and 2 parts of orthophosphoric acid were added to 000 parts, and polymerization was carried out under the same conditions as in Example 1 to obtain a polyester resin having an intrinsic viscosity of 0.68. This polyester resin chip was subjected to solid phase polymerization treatment and bottle molding in the same manner as in Example 1 to obtain a bottle having an internal volume of 1 liter. The light transmittance of the 350 μm thick portion of the bottle body was 65.5% at 360 nm and 67% at 370 nm.

[0029]

According to the present invention, it is possible to easily provide a thermoplastic polyester resin hollow molded container having excellent long-wavelength-side ultraviolet shielding properties without adding an ultraviolet absorber.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location C08K 5/3417 B65D 1/00 A

Claims (2)

[Claims] 1. The following chemical structural formula per 100 parts by weight of a thermoplastic polyester resin. (In the formula, R ¹ and R ² may be the same or different, and represent a hydrogen atom or an optionally substituted alkyl group, alkenyl group, aryl group, aralkyl group or alkylaralkyl group.) Structural formula (Wherein X is NR ³ , and R ³ represents an alkyl group or an aryl group substituted with a carboxyl group or a hydroxyl group. In addition, —C (＝ O) —X—C (＝ O) —
Are 1,2-, 1,8-positions of a naphthalene ring,
A ring is formed at any of the 2- and 3-positions. (1) A thermoplastic polyester resin hollow molded container comprising a resin composition to which at least one of naphthalenedicarboxylic acid and its derivative shown in (1) is added in an amount of 0.001 to 10 parts by weight. 2. A method for producing a thermoplastic polyester resin hollow molded container, comprising injection molding the thermoplastic polyester resin composition according to claim 1 to form a preform, and then blowing the preform.