JP2005170483A - Polyester resin for heat-resistant bottle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin capable of producing a container having less amounts of forming a cyclic trimer and acetaldehyde and excellent in color tone. <P>SOLUTION: A polyester resin bottle comprises a polyester resin polymerized by using a titanium catalyst, and is characterized by having an amount of phosphorus atom extracted into water in a range of 0.08 ppb-0.40 ppb after the bottle is filled with hot water of 90°C and is cooled in the air, and then, it is stored at 35°C for 3 weeks, and an amount of acetaldehyde of ≤100 ppb. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polyester resin capable of forming a hollow molded body such as a bottle with high productivity.

Conventionally, as a material for containers such as seasonings, oils, beverages, cosmetics, and detergents, various resins have been adopted depending on the type of filling contents and the purpose of use.
Of these, polyethylene terephthalate is excellent in mechanical strength, heat resistance, transparency, and gas barrier properties, and is particularly suitable as a material for beverage filling containers such as juices, soft drinks, and carbonated drinks.
Such polyethylene terephthalate is obtained by esterifying terephthalic acid or an ester-forming derivative thereof with ethylene glycol or an ester-forming derivative thereof, followed by liquid phase polycondensation in the presence of a polycondensation catalyst, and then solid phase polycondensation. Can be obtained. The polyethylene terephthalate is supplied to a molding machine such as an injection molding machine to form a preform for a hollow molded body, and the preform is inserted into a mold having a predetermined shape and stretch blow molded, or further subjected to heat treatment (heat Set) and molded into a hollow molded container.
The heat-resistant bottle is required to use a polyester resin using a germanium catalyst, which is an expensive catalyst, in order to increase the molding cost due to the heat treatment process in blow molding and to develop the heat resistance of the bottle. Therefore, it was necessary to reduce the cost of the polyester resin in order to reduce the cost of the heat resistant bottle.

Since the polyester resin for heat-resistant bottles uses an expensive germanium catalyst, its cost increases, and therefore, a polyester resin using a new catalyst has been developed. Among them, development with a titanium catalyst is thriving. However, a polyester resin using a titanium catalyst has a problem that a cyclic trimer and acetaldehyde are generated much more than a conventional germanium catalyst at the time of melt molding, and the color tone tends to be yellow.
The cyclic trimer adheres to the mold surface in the heat treatment process and impairs the bottle appearance, and acetaldehyde deteriorates the image of the beverage and the deterioration of the color tone of the consumer.
JP-A-10-316765

   The present invention is intended to solve the problems associated with the prior art as described above, and provides a polyester resin capable of producing a container having a small amount of cyclic trimer and acetaldehyde and having excellent color tone. It is an object.

As a result of diligent studies to overcome the above problems, when a polyester resin is produced using a titanium catalyst, when an appropriate amount of a phosphorus compound is added, the amount of cyclic trimer and acetaldehyde produced is small, and the color tone is excellent. The present inventors have found that a bottle can be formed and have reached the present invention.
That is, the present invention
(1) A bottle made of a polyester resin polymerized using a Ti catalyst, filled with hot water at 90 ° C., air-cooled, and stored in water at 35 ° C. for 3 weeks. A polyester resin bottle having a range of .08ppb to 0.40ppb and an acetaldehyde amount of 100ppb or less;
(2) The bottle according to (1), wherein the polyester resin is polyethylene terephthalate;
(3) Preform obtained by injection molding using an injection molding machine with a cylinder set temperature of 280 ° C. and a resin residence time in the mold from the injection cylinder of 240 seconds, and a bottle obtained by blow molding using the preform The polyester resin bottle according to any one of (1) to (2), wherein the cyclic trimer amount contained in at least one of the above is 0.50 wt% or less;
(4) It is obtained by blow molding a preform obtained by injection molding using an injection molding machine with a cylinder set temperature of 280 ° C. and a resin residence time in the mold from the injection cylinder of 240 seconds (1) to ( 2) The polyester resin bottle according to 2), wherein the cyclic trimer amount contained in at least one of the raw material preform and the bottle is 0.50 wt% or less.
The polyester of the present invention can be suitably produced by mixing a base polyester not containing a phosphorus compound and master pellets containing a phosphorus compound in an appropriate ratio.

  When the polyester resin of the present invention is molded into a molded body, it can produce a hollow container having a small amount of cyclic trimer and acetaldehyde and further excellent in color tone.

The polyester production method according to the present invention will be specifically described below.
The titanium catalyst used in the polyester resin described in the present invention may be a known titanium compound such as an alkoxytitanium compound, and is preferably a titanium compound described below.

(A) It contains titanium, oxygen, carbon, hydrogen and alkali metal, has a Ti—O—C bond, and has a maximum solubility in ethylene glycol of 1 in terms of titanium atom when dissolved in ethylene glycol at 150 ° C. It is made of a solid titanium-containing compound having a concentration of 000 ppm or more, or (a) ethylene glycol containing titanium, oxygen, carbon and hydrogen, and optionally an alkali metal, having a Ti—O—C bond, and 150 ° C. A solid titanium-containing compound having a maximum solubility in ethylene glycol of 1,000 ppm or more in terms of titanium atom when dissolved in
(B) It consists of an alkali metal compound.

(A) Solid titanium-containing compound The solid titanium-containing compound (a) that forms the catalyst for producing a polyester according to the present invention contains titanium, oxygen, carbon and hydrogen, and if necessary, an alkali metal, Ti-O- Has a C bond.
Here, examples of the alkali metal include Li, Na, K, Rb, and Cs.

The solid titanium-containing compound (a) contains 5 to 50% by weight of titanium, preferably (5 to 40)% by weight, oxygen (35 to 75)% by weight, preferably (40 to 60)% by weight, and carbon. It is desirable to contain 1 to 35% by weight, preferably (5 to 25)% by weight, and hydrogen (1 to 10)% by weight, preferably (1 to 6)% by weight.
Further, the alkali metal is a molar ratio (alkali metal / titanium) with the titanium atom in the solid titanium-containing compound (a), and is 20/1 to 0.1 / 1, preferably 10/1 to 0.1 /. It is desirable to contain it in an amount in the range of 1.
The solid titanium-containing compound (a) has a weight ratio (Ti / C) of titanium atoms to carbon atoms in the compound in the range of 50 to 1, preferably 25 to 2.

The maximum solubility of the solid titanium-containing compound (a) in ethylene glycol is obtained by using only ethylene glycol as a solvent and dissolving the solid titanium-containing compound (a) in 100 g of ethylene glycol under heating at 150 ° C. The transparency is measured with a haze meter, the amount exceeding 10% is confirmed, and the maximum solubility is determined from the amount of the solid titanium-containing compound at that time.
The solid titanium-containing compound (a) has an average particle diameter of 1 to 30 μm, preferably 1.5 to 20 μm.

The solid titanium-containing compound (a) has a crystallinity derived from the structure of anatase-type titanium dioxide calculated from an X-ray diffraction pattern having 2θ (diffraction angle) in the range of 18 ° to 35 ° of 50% or less. Preferably there is.
The solid titanium-containing compound (a) may contain an element other than titanium, oxygen, carbon and hydrogen (hereinafter also simply referred to as “other element”). Examples of such an element include beryllium, Magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, copper, zinc, boron, Examples thereof include at least one element selected from the group consisting of aluminum, gallium, silicon, germanium, tin, antimony, and phosphorus. Of these, magnesium is preferred. Two or more of these other elements may be contained in the solid titanium-containing compound.

The solid titanium-containing compound (a) containing other elements has a molar ratio (M / Ti) between titanium (Ti) in the compound (a) and other elements (M) of 1/50 to 50. / 1, preferably 1/40 to 40/1, more preferably 1/30 to 30/1.
As will be described later, the solid titanium-containing compound (a) can be dissolved in an ethylene glycol-containing liquid (c) and used as a titanium-containing solution. When the solid titanium-containing compound (a) does not contain an alkali metal, it can be used in combination with the alkali metal compound (b) as a catalyst for producing a polyester. When the solid titanium-containing compound (a) contains an alkali metal, it can be used alone or in combination with the alkali metal compound (b) as a catalyst for producing a polyester. In either case, the compound (II) described later may be used in combination as a polyester production catalyst.

(B) Alkali metal compound The alkali metal compound (b) that forms the catalyst for producing a polyester according to the present invention includes an alkali metal simple substance, an alkali metal hydride, an alkali metal hydroxide, an alkali metal alkoxide compound, an alkali metal halide, And carbonic acid, nitric acid, nitrous acid, sulfuric acid, sulfurous acid, organic sulfonic acid, phosphoric acid, phosphorous acid, hypophosphorous acid, metaphosphoric acid, polyphosphoric acid, organic phosphonic acid, organic phosphinic acid, boric acid, aluminate, titanic acid And at least one alkali metal compound selected from the group consisting of alkali metal salts of acids selected from silicic acid, fatty acids, aromatic carboxylic acids, hydroxycarboxylic acids, and amino acids.

Examples of the alkali metal simple substance include Li, Na, K, Rb, and Cs.
Examples of the alkali metal hydride include LiH, NaH, KH, RbH, and CsH.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide and the like.
Examples of the alkali metal alkoxide compound include sodium methoxide, sodium ethoxide and the like.

Examples of alkali metal halides include lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, cesium fluoride, lithium chloride, sodium chloride, potassium chloride, rubidium chloride, cesium chloride, lithium bromide, sodium bromide, Examples include potassium bromide, rubidium bromide, cesium bromide, lithium iodide, sodium iodide, potassium iodide, rubidium iodide, cesium iodide and the like.
Carbonic acid, nitric acid, nitrous acid, sulfuric acid, sulfurous acid, organic sulfonic acid, phosphoric acid, phosphorous acid, hypophosphorous acid, metaphosphoric acid, polyphosphoric acid, organic phosphonic acid, organic phosphinic acid, boric acid, aluminate, titanic acid, Examples of alkali metal salts of acids selected from silicic acid, fatty acids, aromatic carboxylic acids, hydroxycarboxylic acids and amino acids include sodium acetate, sodium propionate, sodium lactate, sodium caproate, sodium caprylate, sodium caprate, laurin Fatty acid alkali metal salts such as sodium phosphate, sodium myristate, sodium palmitate, sodium stearate; alkaline gold carboxylate such as sodium glycolate, sodium lactate, sodium malate, sodium tartrate, sodium citrate, sodium gluconate Salt; sodium glutamate, such as amino acids alkali metal salts of sodium aspartate and the like.

Among these alkali metal compounds (b), sodium hydroxide, potassium hydroxide, sodium methoxide, sodium acetate, sodium stearate and the like are preferable.
These alkali metal compounds (b) can be used singly or in combination of two or more.

    The alkali metal compound (b) is a molar ratio (alkali metal / titanium) between the alkali metal in the alkali metal compound (b) and titanium in the solid titanium-containing compound (a) or in the titanium-containing solution. When the titanium-containing compound (a) contains an alkali metal, the alkali metal in the solid titanium-containing compound (a) and the alkali metal in the alkali metal compound (b) and the solid titanium-containing compound (a) or titanium-containing It is desirable that the molar ratio of the titanium to the solution (alkali metal / titanium) is 20/1 to 0.1 / 1, preferably 10/1 to 0.1 / 1. .

Compound (II)
Compound (II) is a compound of at least one element selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, boron, aluminum, gallium, manganese, cobalt, zinc, germanium, antimony, and phosphorus.
As a compound of at least one element selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, boron, aluminum, gallium, manganese, cobalt, zinc, germanium, antimony and phosphorus, acetates of these elements, etc. Fatty acid salts of these elements, carbonates of these elements, sulfates, nitrates, halides such as chlorides, acetylacetonate salts of these elements, oxides of these elements, etc., but acetates or carbonates are preferable.

  In addition, as the phosphorus compound, a phosphate or phosphite of at least one metal selected from Group 1, Group 2 of the periodic table, transition metal of Periodic Table 4 Period, zirconium, hafnium and aluminum Is mentioned.

  Preferred specific compounds of the compound (II) used as necessary in the present invention include the following.

  Examples of the aluminum compound include fatty acid aluminum salts such as aluminum acetate, aluminum carbonate, aluminum chloride, and acetylacetonate salt of aluminum. Aluminum acetate or aluminum carbonate is particularly preferable.

  Examples of the barium compound include fatty acid barium salts such as barium acetate, barium carbonate, barium chloride, and barium acetylacetonate salt. Barium acetate or barium carbonate is particularly preferable.

  Examples of the cobalt compound include fatty acid cobalt salts such as cobalt acetate, cobalt carbonate, cobalt chloride, cobalt acetylacetonate salt, and the like, and cobalt acetate or cobalt carbonate is particularly preferable.

  Examples of the magnesium compound include fatty acid magnesium salts such as magnesium acetate, magnesium carbonate, magnesium chloride, magnesium acetylacetonate, and the like, and magnesium acetate or magnesium carbonate is particularly preferable.

  Examples of the manganese compound include manganese salt of fatty acid such as manganese acetate, manganese carbonate, manganese chloride, manganese acetylacetonate salt and the like, and manganese acetate or manganese carbonate is particularly preferable.

  Examples of the strontium compound include fatty acid strontium salts such as strontium acetate, strontium carbonate, strontium chloride, and acetylacetonate salt of strontium, and strontium acetate or strontium carbonate is particularly preferable.

  Examples of the zinc compound include fatty acid zinc salts such as zinc acetate, zinc carbonate, zinc chloride, zinc acetylacetonate and the like, and zinc acetate or zinc carbonate is particularly preferable.

  Examples of germanium compounds include germanium dioxide and germanium acetate.

  Examples of the antimony compound include antimony dioxide and antimony acetate.

  Among the phosphorus compounds, the phosphates include lithium phosphate, lithium dihydrogen phosphate, dilithium hydrogen phosphate, sodium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium phosphate, dihydrogen phosphate. Examples include potassium, dipotassium hydrogen phosphate, strontium phosphate, strontium dihydrogen phosphate, distronium hydrogen phosphate, zirconium phosphate, barium phosphate, aluminum phosphate, and zinc phosphate. Of these, sodium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium phosphate, potassium dihydrogen phosphate, and dipotassium hydrogen phosphate are particularly preferably used.

  Among the phosphorus compounds, phosphites include at least one metal phosphite selected from alkali metals, alkaline earth metals, transition metals in the fourth periodic table, zirconium, hafnium, and aluminum. Specific examples include lithium phosphite, sodium phosphite, potassium phosphite, strontium phosphite, zirconium phosphite, barium phosphite, aluminum phosphite, zinc phosphite and the like. It is done. Of these, sodium phosphite and potassium phosphite are particularly preferably used.

Of these, the compound (II) is preferably a magnesium compound such as magnesium carbonate and magnesium acetate; a calcium compound such as calcium carbonate and calcium acetate; and a zinc compound such as zinc chloride and zinc acetate.
These compounds (II) can be used alone or in combination of two or more.
Such a compound (II) has a molar ratio (M / Ti) of titanium (Ti) in the solid titanium-containing compound (a) or the titanium-containing solution to the metal atom (M) in the compound (II). ) In an amount in the range of 1/50 to 50/1, preferably 1/40 to 40/1, more preferably 1/30 to 30/1. In addition, when using phosphorus compounds, such as a phosphate and a phosphite, it is conversion of the metal atom contained in a phosphorus compound.

When a magnesium compound is used as the compound (II), the weight ratio of titanium (Ti) in the solid titanium-containing compound (a) or titanium-containing solution to Mg atoms in the magnesium compound ( It is also desirable that the Mg / Ti) is used in such an amount that it is 0.01 or more, preferably 0.06 to 10, particularly preferably 0.06 to 5.
In the case where the solid titanium-containing compound (a) uses a titanium halide as a raw material, the halogen element content is usually 0 to 10,000 ppm, preferably 0 to 100 ppm.
The solid titanium-containing compound (a) can be used as a catalyst by dissolving in an ethylene glycol-containing liquid (c) containing ethylene glycol, and the solid titanium-containing compound (a) is dissolved in an ethylene glycol-containing liquid (c). When doing so, it is preferable to dissolve in the presence of a basic compound such as the alkali metal compound (b).

  When the solid titanium-containing compound (a) is dissolved in the ethylene glycol-containing liquid (c), it is preferably heated, and the heating temperature is usually 100 to 200 ° C, preferably 110 to 195 ° C.

When the alkali metal compound (b) is used, it is used in an amount such that alkali metal / titanium = 20/1 to 0.1 / 1 in terms of molar ratio to titanium in the solution.
In the present invention, when the solid titanium-containing compound (a) is dissolved in the ethylene glycol-containing liquid (c) in the presence of the alkali metal compound (b), it contains an ethylene glycol containing a dissolution aid as necessary. Liquid (c) can be used. Further, when the alkali titanium compound (b) is not used when the solid titanium-containing compound (a) is dissolved in the ethylene glycol-containing liquid (c), a dissolution aid and / or an acid component is included as necessary. An ethylene glycol-containing liquid (c) can be used.

Examples of the solubilizer include glycerin, trimethylolpropane, propylene glycol, pentaerythritol, sorbitol and the like, and glycerin or trimethylolpropane is preferable.
The dissolution aid is used in an amount of 1 to 50% by weight, preferably 1 to 25% by weight, based on the ethylene glycol-containing liquid (c).

Examples of the acid component include organic sulfonic acids such as sulfuric acid and paratoluenesulfonic acid; organic carboxylic acids such as oxalic acid, acetic acid and citric acid, and sulfuric acid or organic sulfonic acid is preferable.
The acid component is used in an amount of 0.1 to 20% by weight, preferably 0.1 to 10% by weight, based on the ethylene glycol-containing solution.

In this way, a titanium-containing solution, which is a solution in which the solid titanium-containing compound (a) is dissolved in the ethylene glycol-containing liquid (c), is prepared.
This titanium-containing solution is preferably transparent, and has a HAZE value of 30% or less, preferably 20% or less, more preferably 10% or less, measured with a haze meter by the method described later.
In this titanium-containing solution, the content of titanium derived from the solid titanium-containing compound (a) is usually 500 to 100,000 ppm, preferably 3,000 to 100,000 ppm, more preferably 5,000 to 50,000 ppm. It is in the range.
The titanium-containing solution preferably has a moisture content in the range of 0.05 to 15.0% by weight, preferably 0.05 to 10% by weight.

If the amount of phosphorus in the water is too high, the taste of the water may be adversely affected. In order to ensure an appropriate extraction amount of phosphorus atoms, it is necessary to control the amount of phosphorus atoms contained in the bottle material within an appropriate range.
The amount of phosphorus atoms extracted into water depends on the amount of phosphorus contained in the bottle material and the storage conditions of the bottle. In particular, it is important to adjust the amount of phosphorus atoms in the material to an appropriate range. In general, a phosphorus compound is added in the polymerization step in order to ensure thermal stability during processing of the polyester resin. If the amount of phosphorus is too small, the thermal stability of the polyester resin is lowered and acetaldehyde and a cyclic trimer are produced in a large amount. On the other hand, if the addition amount is too large, the addition amount is limited because there is a drawback of inhibiting the polymerization. Therefore, it is preferable to prepare a master pellet containing phosphorus atoms at a high concentration in advance and add it at the time of injection molding.

  The phosphorus concentration in the master pellet is preferably adjusted to be 300 ppm to 1000 ppm, more preferably 300 to 600 ppm. Next, when the master pellet is injection molded, the phosphorus atom concentration in the bottle material is preferably It is preferable to add to the base polymer so as to be 20 ppm to 100 ppm, more preferably 30 ppm to 80 ppm. The bottle which can add a master pellet by such a method can adjust the quantity of the phosphorus atom extracted in the filled water to an appropriate range.

  Such polyethylene terephthalate is excellent in hue, particularly excellent in transparency, has a low acetaldehyde content, and is particularly preferably used for bottles. The polyester produced in this manner is added with conventionally known additives such as heat stabilizers such as phosphorus compounds, mold release agents, antistatic agents, dispersants, colorants such as dyes and the like. These additives may be added at any stage during the production of the polyester, or may be added by a master pellet before molding.

The polyester obtained by the present invention can be used as a raw material for various molded products, for example, melt molded and used for hollow molded products such as bottles, sheets, films, fibers, etc. preferable. Among them, it is suitable for heat-resistant bottles.
For example, when molding a bottle, the polyethylene terephthalate is extruded from a die in a molten state to form a tubular parison, and then the parison is held in a mold having a desired shape, and then air is blown into the mold to be attached to the mold. A method for producing a hollow molded body, producing a preform from the above polyethylene terephthalate by injection molding, heating the preform to a temperature suitable for stretching, and then holding the preform in a mold having a desired shape and then air. There is a method of producing a hollow molded body by blowing and mounting on a mold.
As a method of forming a film or sheet, there is a method of extruding molten polyester from a T-die or the like using a conventionally known extrusion apparatus and molding conditions. These films and sheets may be stretched by a known stretching method.

(Example)

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
(Reference Example 1)

Preparation of titanium catalyst In a 1,000 ml glass beaker, 500 ml of deionized water was weighed, cooled in an ice bath, and 5 g of titanium tetrachloride was added dropwise with stirring. When the generation of hydrogen chloride ceased, it was removed from the ice bath and 25% aqueous ammonia was added dropwise with stirring at room temperature to adjust the pH of the solution to 9. A 15% aqueous acetic acid solution was added dropwise thereto while stirring at room temperature to adjust the pH of the solution to 5. The formed precipitate was separated by filtration. The washed precipitate is retained in 30 wt% ethylene glycol-containing water as a slurry having a slurry concentration of 2.0 wt% for 30 minutes, and then granulated and dried at a temperature of 90 ° C. using a two-fluid nozzle type spray dryer. A solid hydrolyzate (solid titanium-containing compound) was obtained.

The particle size distribution of the obtained solid titanium-containing compound was 0.5 to 20 μm, and the average particle size was 1.8 μm.
The content of titanium metal in the solid titanium-containing compound measured by ICP analysis was 34.8% by weight.
It was confirmed by elemental analysis, EXAFS analysis, and ¹³ C-NMR analysis that the solid titanium-containing compound contained titanium, oxygen, carbon and hydrogen and had a Ti—O—C bond. The maximum solubility of the solid hydrolyzate in ethylene glycol was 3,000 ppm, the carbon content was 11.6 wt%, and the weight ratio of titanium to carbon (Ti / C) was 3.

  In a 200 ml glass flask, 102 g of ethylene glycol and 18 g of glycerin were weighed, and 1.74 g of sodium hydroxide was added and dissolved therein. To this was added 3.38 g of the above solid titanium-containing compound, and the mixture was dissolved by heating at 120 ° C. for 30 minutes to prepare a titanium-containing solution as a catalyst for polyester production. The titanium metal content in the titanium-containing solution measured by ICP analysis was 1.0% by weight, and this solution was measured using a haze meter (ND-1001DP, manufactured by Nippon Denshoku Industries Co., Ltd.). The HAZE value was 1.0%.

Production of polyester In a reactor in which 33,500 parts by weight of the reaction liquid (during steady operation) stays in advance, it was maintained at 260 ° C. and 0.9 kg / cm ² G (0.09 MPaG) in a nitrogen atmosphere under stirring. Under the conditions, a slurry prepared by mixing 6,458 parts by weight of high-purity terephthalic acid and 2,615 parts by weight of ethylene glycol was continuously supplied to perform an esterification reaction. In this esterification reaction, a mixed solution of water and ethylene glycol was distilled off.
The esterification reaction product (low-order condensate) was continuously extracted from the system while controlling the average residence time to be 3.5 hours.

The number average molecular weight of the low-order condensate of ethylene glycol and terephthalic acid obtained above was 600 to 1,300 (3 to 5 mer).
Using the titanium catalyst solution prepared in Reference Example 1 as the polycondensation catalyst, a polycondensation reaction of the low-order condensate obtained above was performed.
At that time, the amount of each catalyst added was converted to titanium atoms, the solution of Reference Example 1 was added so as to be 18 ppm with respect to the produced polyethylene terephthalate, and phosphoric acid was converted to phosphorous atoms to produce polyethylene terephthalate. On the other hand, polycondensation was performed under the conditions of 285 ° C. and 0.1 kPa (1 Torr) in addition to 6 ppm, and the time for obtaining a liquid heavy polyethylene terephthalate having an intrinsic viscosity of 0.64 dl / g was measured.

  Next, the obtained liquid heavy polyethylene terephthalate was pre-crystallized at 170 ° C. for 2 hours, and then heated at 220 ° C. in a nitrogen gas atmosphere to have an intrinsic viscosity of 0.64 dl / g to 0.84 dl / g. The molecular weight was increased by solid phase polymerization until The solid phase polycondensation time required at this time was 7.4 (h).

Production of phosphorus-containing master pellets 42 g of 85% phosphoric acid aqueous solution was added to 1 liter of water, and the above-mentioned polyester resin pellets were immersed in this diluted phosphoric acid aqueous solution for 2 hours. The pellets were dehydrated with nitrogen gas and dried in an oven at 120 ° C. for 2 hours. The dried pellets were melted at a set temperature of 280 to 290 ° C. using a twin screw extruder (PCM45) manufactured by Ikekai Seiki Co., Ltd., the strands were extruded, and further pellets were produced using a rotary cutter. The amount of phosphorus in the pellet material was 300 ppm.
The polyester resin obtained by molding the bottle was mixed so that the weight ratio of phosphorus-containing master pellets and polyester resin / master pellets = 95/5, and dried at 170 ° C. for 4 hours using a dehumidifying air dryer. The dried polyethylene terephthalate was first molded using a NISSEI resin ES600 injection molding machine at a cylinder set temperature of 270 to 280 ° C. and a residence time in the cylinder of about 250 seconds to obtain a preform. Subsequently, the preform temperature was set to 100 ° C. to 120 ° C., stretch blow molding, and a bottle were obtained using a Sdel 01 stretch blow molding machine manufactured by Sidel. The heat setting was performed at a mold temperature around 145 ° C.
Liquid filling and storage Ultrapure water was heated to 90 ° C. and kept warm, and filled into the bottle. The bottle was sealed with a plastic cap and stored in an oven at 35 ° C. for 3 weeks.

Quantification of phosphorus atoms in water Phosphorus atoms were directly quantified using high resolution ICP-MS (Plasmax 2 manufactured by JEOL) from water collected from the bottle.
An aqueous solution of dinitrophenylhydrazone / perchloric acid was added to water collected from an analysis bottle for acetaldehyde in water, and the aldehyde contained therein was converted to a hydrazone derivative. The aldehyde derivative was analyzed by liquid chromatography, and the aldehyde was quantified by the peak area.
Equipment Hewlett Packard Company Model 1100
Column: Waters μ-bonda sphere C4 (reverse phase)
Detection wavelength: 360 nm

Measurement of amount of cyclic trimer in bottle material After dissolving a predetermined amount of polyethylene terephthalate bottle and preform in o-chlorophenol, reprecipitating with tetrahydrofuran and filtering to remove linear polyethylene terephthalate, The obtained filtrate was supplied to liquid chromatography (LC7A manufactured by Shimadzu Corporation) to determine the amount of cyclic trimer contained in polyethylene terephthalate, and this value was divided by the weight of the polyethylene terephthalate sample used for the measurement. The cyclic trimer content (% by weight) contained in the terephthalate bottle and preform material was used.
The bottle color tone (b value) measurement sample was cut into a pellet size with a pruner at the mouth of the bottle or preform. The b value was measured using a Hunter color difference meter.

A molded product was obtained in the same manner as in Example 1 except that the weight ratio of the polyester resin to the phosphorus-containing master pellet was 90/10.
(Comparative Example 1)

  A molded product was obtained in the same manner as in Example 1 except that the phosphorus-containing master pellet was not added to the polyester resin.

Claims (5)

A bottle made of a polyester resin polymerized using a Ti catalyst, filled with hot water at 90 ° C., air-cooled, and stored in water at 35 ° C. for 3 weeks, the amount of phosphorus atoms extracted from water is 0.08 ppb A polyester resin bottle having a range of 0.40 ppb and an acetaldehyde amount of 100 ppb or less. The bottle according to claim 1, wherein the polyester resin is polyethylene terephthalate. At least one of a preform obtained by injection molding using an injection molding machine at a cylinder set temperature of 280 ° C. and a resin residence time in the mold from the injection cylinder of 240 seconds and a bottle obtained by blow molding using the preform. The polyester resin bottle according to claim 1, wherein the amount of the cyclic trimer contained in is 0.50 wt% or less. 3. The product according to claim 1, which is obtained by blow molding a preform obtained by injection molding using an injection molding machine at a cylinder set temperature of 280 ° C. and a resin residence time in the mold from the injection cylinder of 240 seconds. A polyester resin bottle, wherein the amount of cyclic trimer contained in at least one of the raw material preform and the bottle is 0.50 wt% or less. The manufacturing method which obtains the polyester resin bottle of Claim 1 thru | or 4 by using as a raw material the resin composition obtained by melt-mixing (A) polyester resin and (B) the same kind of polyester resin containing a phosphorus compound.