JP2001114886A - Polyethylene terephthalate and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyethylene terephthalate having high fluidity when melted, and excellent in moldability, and further to provide a preform for a blow molded product and the blow molded product, obtained from the polyethylene terephthalate. SOLUTION: This polyethylene terephthalate satisfies the formula: Y>=647-500X [Y is the ratio (L/T) of a flow length (L) to a flow thickness (T) when molding the polyethylene terephthalate at 290 deg.C; X (dl/g) is an intrinsic viscosity of the molded product obtained by the injection molding].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polyethylene terephthalate and uses thereof, and more particularly, to polyethylene terephthalate having high flowability upon melting and excellent moldability, and a preform for a hollow molded article obtained from the polyethylene terephthalate. And a hollow molded article.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Polyethylene terephthalate is
It is excellent in mechanical strength, heat resistance, transparency and gas barrier properties, and is suitably used as a material for beverage filling containers such as juices, soft drinks and carbonated drinks, as well as films, sheets and fibers.

[0003] Such polyethylene terephthalate forms a lower condensate (ester low polymer) by, for example, an esterification reaction of terephthalic acid and ethylene glycol, and then forms the lower condensate in the presence of a polycondensation catalyst. A high molecular weight is obtained by a glycol removal reaction (liquid phase polycondensation). In some cases, solid-phase polycondensation is performed to further increase the molecular weight. In such a method for producing polyethylene terephthalate, an antimony compound, a germanium compound, or the like is generally used as a polycondensation catalyst.

[0004] However, when an antimony compound or a germanium compound is used as a polycondensation catalyst, the resulting polyethylene terephthalate has low melt fluidity and may not have sufficient moldability.

The present inventors have conducted intensive studies in view of the prior art as described above, and have found that polyethylene terephthalate obtained using a specific polycondensation catalyst has high melt fluidity and excellent moldability. Thus, the present invention has been completed.

[0006]

That is, an object of the present invention is to provide a polyethylene terephthalate having high flowability at the time of melting and excellent moldability, and a preform for a hollow molded article and a hollow molded article obtained from the polyethylene terephthalate. It is intended to provide a molded article.

[0007]

SUMMARY OF THE INVENTION Polyethylene terephthalate according to the present invention is obtained by injection molding at 290 ° C. where the ratio (L / T) of the flow length (L) to the flow thickness (T) is Y, When the intrinsic viscosity of the molded product is X (dl / g), the X and Y have a relationship of Y ≧ 647-500X.

The polyethylene terephthalate is, for example, a hydrolyzate (Ia) obtained by hydrolyzing a titanium halide, a compound of at least one element selected from titanium halide and another element other than titanium, or a precursor of this compound. In the presence of a polycondensation catalyst (I) consisting of a hydrolyzate (Ib) obtained by hydrolyzing a mixture with
Or the polycondensation catalyst (I) and (II) beryllium, magnesium, calcium, strontium, barium,
Terephthalic acid or an ester-forming derivative thereof in the presence of a co-catalyst compound consisting of a compound of at least one element selected from the group consisting of boron, aluminum, gallium, manganese, cobalt, zinc, germanium, antimony and phosphorus. , Ethylene glycol or its ester-forming derivative by polycondensation.

The compound of at least one element selected from the above-mentioned elements other than titanium or a precursor of this compound is, for example, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, zirconium, hafnium, vanadium. Selected from the group consisting of, niobium, tantalum, chromium, molybdenum, tungsten, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, copper, zinc, boron, aluminum, gallium, silicon, germanium, tin, antimony and phosphorus At least one
It is a compound of a species element or a precursor of this compound.

[0010] The promoter compound (II) is preferably a magnesium compound. A preform for a hollow molded article and a hollow molded article according to the present invention are characterized by being obtained from the above polyethylene terephthalate.

[0011]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the polyethylene terephthalate according to the present invention and its use will be described.

The polyethylene terephthalate according to the present invention is composed of a repeating unit derived from terephthalic acid or an ester-forming derivative thereof, and a repeating unit derived from ethylene glycol or an ester-forming derivative thereof. Further, the polyethylene terephthalate may contain a repeating unit derived from another dicarboxylic acid and / or another diol of 20 mol% or less.

Specific examples of dicarboxylic acids other than terephthalic acid include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid; adipic acid, sebacic acid, azelaic acid; Aliphatic dicarboxylic acids such as decane dicarboxylic acid; alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid; and ester-forming derivatives thereof.

Specific examples of diols other than ethylene glycol include aliphatic glycols such as diethylene glycol, trimethylene glycol, propylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol; and cyclohexane dimethanol. Alicyclic glycol; bisphenols, hydroquinone, 2,2-bis (4-β-hydroxyethoxyphenyl) propane, 1,3-
Bis (2-hydroxyethoxy) benzene, 1,4-bis (2-
Aromatic diols such as (hydroxyethoxy) benzene and the like and ester-forming derivatives thereof are mentioned.

The polyethylene terephthalate according to the present invention may contain a repeating unit derived from a polyfunctional compound such as trimesic acid, trimethylolethane, trimethylolpropane, trimethylolmethane, and pentaerythritol. It is preferable to use the repeating unit derived from such a polyfunctional compound in a proportion of 0 to 2 mol% based on the repeating unit derived from the diol. Polyethylene terephthalate in which the repeating unit derived from the polyfunctional compound is contained in the amount described above tends to have high fluidity at the time of melting.

The intrinsic viscosity of the polyethylene terephthalate according to the present invention is usually 0.50 dl / g or more, preferably 0.50 to 1.50 dl / g, more preferably 0.72 dl / g.
It is desirably about 1.0 dl / g. The intrinsic viscosity of polyethylene terephthalate is calculated from the solution viscosity measured at 25 ° C. after heating and dissolving 1.2 g of polyethylene terephthalate in 15 cc of o-chlorophenol.

The density is usually at least 1.37 g / cm ³ , preferably 1.37 to 1.44 g / cm ³ , more preferably 1.38 to 1.43 g / cm ³ , and still more preferably 1.39 to 1.33 g / cm ³ . Desirably, it is 1.42 g / cm ³ . The density of polyethylene terephthalate is determined by a density gradient tube using a mixed solvent of carbon tetrachloride and heptane.
It is measured at a temperature of 23 ° C.

In the polyethylene terephthalate according to the present invention, the ratio (L / T) of the flow length (L) to the flow thickness (T) when injection-molded at 290 ° C. is Y, and the molding obtained by the above-mentioned injection molding. When the intrinsic viscosity of the body is X (dl / g), X and Y satisfy the following relationship.

Y ≧ 647-500X, preferably Y ≧ 647.5-500X, more preferably Y ≧ 648-500X As described above, the flow length (L) and the flow thickness (T) at the time of injection molding at 290 ° C. And the intrinsic viscosity of the molded article obtained by injection molding is X (dl / g).
When X and Y satisfy the above relationship, polyethylene terephthalate has high melt fluidity and excellent moldability even when the intrinsic viscosity is high.

In the present invention, the ratio (L / T) of the flow length (L) to the flow thickness (T) when polyethylene terephthalate is injection-molded at 290 ° C. is measured as follows. That is, 2 kg of granular polyethylene terephthalate (pellet-like polyethylene terephthalate) was heated at a temperature of 14 kg.
Drying is performed using a tray-type drier for 16 hours or more at 0 ° C. and a pressure of 10 Torr to reduce the water content of the granular polyethylene terephthalate to 50 ppm or less.

Next, the dried sample was subjected to M7 manufactured by Meiki Seisakusho Co., Ltd.
Using a 0B type injection molding machine, molding is performed at a cylinder temperature of 290 ° C. and an L / T mold manufactured by Mitsui Chemicals, Inc. at a mold temperature of 15 ° C. under the following conditions.

Injection pressure: 120 kg / cm ² (gauge pressure) Injection speed: 90% Measuring position: constant at 40 mm Injection time: constant at 10 seconds Cooling time: constant at 20 seconds The L / T mold has a cavity of 125 cm ( It has a shape of (length) × 10 mm (width) × 2 mm (thickness), and a gate is provided at an end in the length direction.

The injected resin flows spirally in the cavity around the gate portion, and the molten resin moves in the cavity while maintaining the shape of 10 mm in width and 2 mm in thickness (T).

As the L / T measurement sample, a sample obtained by sampling from the 11th shot to the 20th shot from the start of molding is used, and the flow length (L) is measured, the average value is obtained, and the L / T is calculated. .

The molded product obtained by the above injection molding has an intrinsic viscosity of 0.5 g / dl using a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (50/50 weight ratio).
Was prepared, and the intrinsic viscosity was calculated from the solution viscosity measured at 25 ° C. The intrinsic viscosity measurement sample is collected from the L / T measurement sample.

In the polyethylene terephthalate according to the present invention, the ratio (Y) of the flow length to the flow thickness when injection molded at 290 ° C. and the intrinsic viscosity (X) of the molded product obtained by the injection molding are as described above. And such polyethylene terephthalate has high fluidity at the time of melting,
Excellent moldability.

Further, the polyethylene terephthalate according to the present invention preferably has a titanium atom content in the range of 1 to 100 ppm, particularly 1 to 80 ppm, and a magnesium atom content of 1 to 200 ppm, particularly 1 to 100 ppm.
pm. The weight ratio (Mg / Ti) between titanium atoms and magnesium atoms contained in the polyethylene terephthalate may be 0.01 or more, preferably 0.06 to 10, and particularly preferably 0.06 to 5. desirable. Polyethylene terephthalate having a weight ratio of titanium atoms to magnesium atoms (Mg / Ti) within the above range tends to have excellent transparency. Further, the polyethylene terephthalate preferably has a chlorine content of 0 to 1000 ppm, particularly preferably 0 to 100 ppm.

The polyethylene terephthalate of the present invention having the above-mentioned properties can be produced, for example, by the following method. In the present invention, polyethylene terephthalate is produced using terephthalic acid or an ester-forming derivative thereof, ethylene glycol or an ester-forming derivative thereof, and, if necessary, the above-mentioned dicarboxylic acids, diols, and polyfunctional compounds as raw materials.

The raw material containing terephthalic acid or its ester-forming derivative as described above and ethylene glycol or its ester-forming derivative is esterified. Specifically, first, a slurry containing terephthalic acid or an ester-forming derivative thereof and ethylene glycol or an ester-forming derivative thereof is prepared.

The slurry contains 1.02 to 1.1 mol per mol of terephthalic acid or its ester-forming derivative.
It contains 4 moles, preferably 1.03 to 1.3 moles of ethylene glycol or an ester-forming derivative thereof.
This slurry is continuously supplied to the esterification reaction step.

In the esterification reaction, preferably, water produced by the reaction is removed outside the system by a rectification column under the condition that ethylene glycol is refluxed using a device in which two or more esterification reactors are connected in series. It is implemented while. The reaction conditions for performing the esterification reaction are such that the temperature of the first-stage esterification reaction is usually 240 to 270 ° C., preferably 24 to 270 ° C.
5 to 265 ° C. and the pressure is usually 0.2 to 3 kg / c
m ² G, preferably 0.5 to ² kg / cm ² G, and the temperature of the final esterification reaction is usually 250 to 28 kg / cm ² G.
0 ° C., preferably 255-275 ° C., and the pressure is usually 0-1.5 kg / cm ² G, preferably 0-1.3 kg.
/ Cm ² G.

When the esterification reaction is carried out in two stages, the first and second stage esterification reaction conditions are within the above ranges, respectively. The reaction conditions of the esterification reaction from the first stage to the stage immediately before the last stage are those between the above-mentioned first-stage reaction conditions and the last-stage reaction conditions.

For example, when the esterification reaction is carried out in three stages, the reaction temperature of the second stage esterification reaction is usually 245-275 ° C., preferably 250-270 ° C.
° C, and the pressure is usually 0 to ² kg / cm ² G, preferably 0.2 to 1.5 kg / cm ² G. The conversion of these esterification reactions, at each stage,
Although there is no particular limitation, it is preferable that the degree of increase in the esterification reaction rate in each stage is smoothly distributed, and the final stage of the esterification reaction product is usually 90%.
%, Preferably at least 93%.

An esterified product (low-order condensate) is obtained by these esterification steps, and the number-average molecular weight of the esterified product is usually from 500 to 5,000. Such an esterification reaction can be carried out without adding any additives other than terephthalic acid and ethylene glycol, and can be carried out in the presence of a polycondensation catalyst described later. Tertiary amines such as triethylamine, tri-n-butylamine and benzyldimethylamine; quaternary ammonium hydroxides such as tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide and trimethylbenzylammonium hydroxide; lithium carbonate and sodium carbonate When a small amount of basic compounds such as potassium carbonate and sodium acetate are added to esterify terephthalic acid and ethylene glycol, the ratio of dioxyethylene terephthalate component units in the main chain of polyethylene terephthalate is kept at a relatively low level. It is preferable because it is possible.

Next, the obtained esterified product is supplied to a liquid phase polycondensation step. In this liquid phase polycondensation step, the resulting polyethylene terephthalate is heated to a temperature equal to or higher than the melting point of the obtained polyethylene terephthalate under reduced pressure in the presence of a polycondensation catalyst. I do.

Such a polycondensation reaction in the liquid phase may be performed in one stage or may be performed in a plurality of stages. When the polycondensation reaction is performed in a plurality of stages, the reaction temperature of the first stage polycondensation is usually from 250 to 290C, preferably from 26 to 290C.
0 to 280 ° C., and the pressure is usually 500 to 20 Torr.
r, preferably 200 to 30 Torr, the temperature of the final polycondensation reaction is usually 265 to 300 ° C, preferably 270 to 295 ° C, and the pressure is usually 10 to 0.1 Torr.
rr, preferably 5 to 0.5 Torr.

When the polycondensation reaction is carried out in two stages,
The conditions of the polycondensation reaction of the first and second stages are respectively in the above ranges.
The reaction conditions for the polycondensation reaction from the first stage to the last stage before the last stage are those between the above-mentioned first stage reaction conditions and the last stage reaction conditions.

For example, when the polycondensation reaction is carried out in three stages, the reaction temperature of the second stage polycondensation reaction is usually 26.
0-295 ° C., preferably 270-285 ° C., and the pressure is usually in the range of 50-2 Torr, preferably 40-5 Torr. The intrinsic viscosity (IV) reached in each of these polycondensation reaction steps is not particularly limited, but it is preferable that the degree of increase in the intrinsic viscosity in each stage be distributed smoothly.

The intrinsic viscosity of polyethylene terephthalate obtained from the last stage polycondensation reactor is usually 0.1.
35 to 0.80 dl / g, preferably 0.45 to 0.7
5 dl / g, more preferably 0.55 to 0.75 dl
/ G is desirable. The intrinsic viscosity is 1.2 g of polyethylene terephthalate and o-chlorophenol 1
After heating and dissolving in 5 cc, it is cooled and then calculated from the solution viscosity measured at 25 ° C.

The density of this polyethylene terephthalate
Is usually 1.33 to 1.35 g / cm ^ThreeHope to be
Good. The polycondensation reaction as described above depends on the presence of a polycondensation catalyst.
And preferably in the presence of a stabilizer.
New

As the polycondensation catalyst, titanium butoxide,
A titanium compound catalyst such as a titanium alkoxide such as titanium tetraisopropoxide; an organic titanium compound such as an acetylacetonate salt of titanium; and a hydrolyzate obtained by hydrolyzing a titanium alkoxide or hydrolyzing a titanium halide is used. When hydrolyzing titanium alkoxide or titanium halide,
A compound of at least one element selected from elements other than titanium or a precursor of this compound (hereinafter, sometimes referred to as a “compound of another element”) may coexist.

In the present invention, as the polycondensation catalyst, (Ia) a hydrolyzate obtained by hydrolyzing a titanium halide or (Ib) a compound of at least one element selected from titanium halide and another element other than titanium Alternatively, it is preferable to use a polycondensation catalyst (I) composed of a hydrolyzate obtained by hydrolyzing a mixture of the compound and a precursor thereof.

The titanium halide used for preparing the above hydrolyzate is a compound in which at least one bond between a titanium atom and a halogen atom is present in the molecule, specifically, titanium tetrachloride, titanium tetrabromide and the like. Titanium tetrahalides such as titanium and titanium tetraiodide; titanium trihalides such as titanium trichloride; dihalides such as titanium dichloride and titanium monohalide.

The method for hydrolyzing the titanium halide is not particularly limited, and includes, for example, a method of adding a titanium halide to water, a method of adding water to a titanium halide, and a method of adding a titanium halide vapor to water. A gas containing water vapor in a titanium halide, a method of contacting a gas containing titanium halide with a gas containing water vapor, and the like.

As described above, the hydrolysis method is not particularly limited, but in any case, it is necessary to allow a large excess of water to act on the titanium halide to completely advance the hydrolysis. If the hydrolysis does not proceed completely and the resulting hydrolyzate is a partial hydrolyzate as described in JP-B-51-19477, the polycondensation rate may not be sufficient.

The temperature at which the hydrolysis is carried out is usually 100 ° C. or lower, preferably in the range of 0 to 70 ° C. Compounds of other elements that may be present during the hydrolysis of titanium halide 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, aluminum, gallium, silicon, germanium, tin,
Examples include a compound of at least one element selected from the group consisting of antimony and phosphorus (hereinafter, these elements are referred to as “other elements”) or a precursor of this compound. Examples of the compound of the other element include a hydroxide and the like.

The compounds of these other elements can be used alone or in combination of two or more. In order to hydrolyze a titanium halide in the presence of a compound of another element, for example, a mixture of a titanium halide and a compound of another element is hydrolyzed.

The method of hydrolyzing a mixture of a titanium halide and a compound of another element is not particularly limited. For example, a method of adding a titanium halide to water in which a compound of another element is dissolved or suspended, A method of adding a mixture of a titanium halide and a compound of another element in water, a method of adding water to a mixture of a compound of a titanium halide and a compound of another element, and a method of adding a compound of the other element in the titanium halide. A method of adding dissolved or suspended water, a method of passing a gas containing titanium halide vapor in water in which a compound of another element is dissolved or suspended,
A method comprising passing a gas containing water vapor of a titanium halide and a compound of another element in water, a method of passing a gas containing water vapor in a mixture of a compound of a titanium halide and a compound of another element, Through a gas containing water vapor and a vapor of a compound of another element,
A method of contacting a gas containing a titanium halide with a gas containing a vapor of a compound of another element and a gas containing water vapor may be used.

During the hydrolysis, the molar ratio (E / Ti) of titanium (Ti) in the titanium halide to the other element (E) in the compound of the other element is 1/50 to 50. / 1
Is desirably within the range. The temperature at which the hydrolysis is carried out is usually 100 ° C. or lower, preferably in the range of 0 to 70 ° C.

When a titanium halide or a mixture of a titanium halide and a compound of another element is hydrolyzed, the liquid property becomes acidic due to hydrogen halide generated by hydrolysis of the titanium halide. Since hydrolysis may not be completed due to this acidity, a base may be added for neutralization. Examples of the base used herein include aqueous ammonia, sodium hydroxide, potassium hydroxide, and hydroxides of Group 1 and 2 elements of the elements such as magnesium hydroxide, or sodium carbonate, sodium hydrogen carbonate, potassium carbonate, Examples of the element such as potassium hydrogen carbonate include carbonic acid (hydrogen) compounds of Group 1 and 2 of the periodic table, urea, and basic organic compounds. The pH of the neutralization end point is preferably 4 or more, and the neutralization is preferably performed at 70 ° C. or less.

The hydrolyzate obtained by the above-mentioned hydrolysis is, at this stage, a gel of a hydrous hydroxide also called orthotitanic acid or a hydrous composite hydroxide gel containing other elements. This hydrous hydroxide gel or hydrous composite hydroxide gel can be used as it is as the polycondensation catalyst (I), but can be dehydrated and dried to obtain a solid hydrolyzate (solid titanium-containing compound). preferable. In addition, some of the hydroxyl groups may be removed by this drying.

Drying of the hydrolyzate can be carried out under normal pressure or reduced pressure, in a solid phase or in a state of being suspended in a liquid phase having a boiling point higher than that of water. The drying temperature is not particularly limited.
The temperature is preferably not less than 350 ° C. The water-soluble hydroxide gel or the water-containing composite hydroxide gel may be washed with water before drying, or the solid titanium-containing compound may be washed with water after drying to remove water-soluble components. It is preferable that drying be performed promptly.

The solid titanium-containing compound thus obtained has a different composition depending on the presence or absence and amount of other coexisting elements, the presence or absence of water washing, the drying method, and the degree of drying. (Ti) molar ratio (OH / T
i) is usually more than 0.09 and less than 4, preferably 0.1
To 3, more preferably 0.1 to 2 in terms of polycondensation activity. The molar ratio between the hydroxyl group and titanium can be determined by measuring the attached moisture and the heat desorbed moisture.

The molar ratio between the hydroxyl group and titanium is specifically determined as follows. In order to determine the hydroxyl group content in the solid titanium-containing compound, first, the amount of attached moisture is measured by a Karl Fischer moisture meter. Next, by heating to 600 ° C. by thermogravimetric analysis, the amount of water desorbed by heating is measured. By heating to 600 ° C., the attached water is desorbed, and the hydroxyl group is considered to be desorbed as water.
The hydroxyl group content is determined from the value obtained by subtracting the amount of attached moisture from the amount of moisture desorbed by heating. The titanium content in the solid titanium-containing compound is determined by a high-frequency plasma emission analyzer. The OH / Ti ratio is determined from the titanium content and the hydroxyl group content.

In this solid titanium-containing compound, a hydroxyl group remains even at a temperature at which a polycondensation reaction is performed, for example, at about 280 ° C. When the solid titanium-containing compound contains another element, the molar ratio (E / Ti) between titanium (Ti) and the other element (E) in the compound is 1/50 to 50 /.
1, preferably 1/40 to 40/1, more preferably 1/30 to 30/1.

The hydrous hydroxide gel or hydrous composite hydroxide gel solid titanium-containing compound usually has a chlorine content of from 0 to 10%.
000 ppm, preferably 0-100 ppm. Such a hydrous hydroxide gel, a hydrous composite hydroxide gel, and a solid titanium-containing compound (polycondensation catalyst (I)) are used in combination with a cocatalyst compound (II) as necessary.

The cocatalyst compound (II) includes beryllium, magnesium, calcium, strontium, barium, boron, aluminum, gallium, manganese, cobalt,
It is a compound of at least one element selected from the group consisting of zinc, germanium, antimony and phosphorus, and specifically, fatty acid salts such as acetates of these elements, carbonates of these elements, and carbonates of these elements. Sulfates, halides such as nitrates and chlorides of these elements, acetylacetonate salts of these elements, oxides of these elements, etc. are preferred, and acetates or carbonates are preferred.

Examples of the phosphorus compound include phosphates of at least one metal selected from transition metals of the first and second groups of the periodic table, the fourth period of the periodic table, zirconium, hafnium and aluminum. Phosphites.

More specifically, examples of the cocatalyst compound (II) include aluminum compounds such as aluminum salts of fatty acids such as aluminum acetate, aluminum carbonate, aluminum chloride, and acetylacetonate salts of aluminum. Aluminum carbonate is preferred.

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

Examples of the cobalt compound include cobalt salts of fatty acids such as cobalt acetate, cobalt carbonate, cobalt chloride, and the like.
Acetyl acetonate salt of cobalt and the like are mentioned, and particularly, cobalt acetate or cobalt carbonate is preferable.

Examples of the magnesium compound include a fatty acid magnesium salt such as magnesium acetate, magnesium carbonate, magnesium chloride, and acetylacetonate salt of magnesium. Particularly preferred is magnesium acetate or magnesium carbonate.

The manganese compounds include manganese salts of fatty acids such as manganese acetate, manganese carbonate, manganese chloride,
Manganese acetylacetonate salt and the like can be mentioned, and manganese acetate or manganese carbonate is particularly preferable.

Examples of the strontium compound include strontium salts of fatty acids such as strontium acetate, strontium carbonate, strontium chloride, and acetylacetonate salt of strontium. Strontium acetate and strontium carbonate are particularly preferable.

Examples of the zinc compound include zinc salts of fatty acids such as zinc acetate, zinc carbonate, zinc chloride, and acetylacetonate salt of zinc. Zinc acetate and zinc carbonate are particularly preferred.

Examples of the germanium compound include germanium dioxide, germanium acetate and the like. Examples of the antimony compound include antimony dioxide and antimony acetate.

Among the phosphorus compounds, phosphates include lithium phosphate, lithium dihydrogen phosphate, dilithium hydrogen phosphate, sodium phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, potassium phosphate, and phosphorus phosphate. Examples include potassium dihydrogen acid, dipotassium hydrogen phosphate, strontium phosphate, strontium dihydrogen phosphate, distrontium 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, dipotassium hydrogen phosphate are preferably used.

The phosphite of the phosphorus compound includes at least one metal selected from the group consisting of alkali metals, alkaline earth metals, transition metals of the fourth period of the periodic table, zirconium, hafnium and aluminum. An acid salt is used, specifically, lithium phosphite, sodium phosphite, potassium phosphite, strontium phosphite, zirconium phosphite, barium phosphite, aluminum phosphite, zinc phosphite And the like. Of these, sodium phosphite and potassium phosphite are particularly
It is preferably used.

Among these, preferred are co-catalyst compounds such as magnesium compounds such as magnesium carbonate and magnesium acetate; calcium compounds such as calcium carbonate and calcium acetate; and zinc compounds such as zinc chloride and zinc acetate. When a magnesium compound is used as a cocatalyst compound, polyethylene terephthalate having excellent transparency can be obtained.

These cocatalyst compounds can be used alone or in combination of two or more. Such a co-catalyst compound comprises titanium (or titanium and other elements when the titanium-containing hydrolyzate contains other elements) (I) in the polycondensation catalyst and a metal atom (II) in the co-catalyst compound. ) With a molar ratio [(II) / (I)] of 1/50 to 50/1,
Preferably 1/40 to 40/1, more preferably 1/3
Desirably, it is used in an amount ranging from 0 to 30/1.
When a phosphorus compound such as a phosphate or a phosphite is used, the conversion is based on the metal atom contained in the phosphorus compound.

The stabilizers used as necessary in the polycondensation reaction include phosphate esters such as trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate and tricresyl phosphate; Phosphites such as phenyl phosphite, trisdodecyl phosphite and trisnonyl phenyl phosphite; acidic phosphorus such as methyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, dibutyl phosphate, monobutyl phosphate, dioctyl phosphate and the like Acid esters and phosphorus compounds such as phosphoric acid, phosphorous acid, hypophosphorous acid and polyphosphoric acid are used.

In the case of a polycondensation catalyst, the ratio of the polycondensation catalyst or the stabilizer to be used is usually 0.1 to 100 parts by weight of the weight of the metal in the polycondensation catalyst. 0005 to 0.2% by weight, preferably 0.001 to 0.05% by weight, and the stabilizer is usually 0.001 to 0.1% by weight as a weight of phosphorus atom in the stabilizer; Preferably 0.002-
It is in the range of 0.02% by weight. These polycondensation catalysts and stabilizers can be supplied at the stage of the esterification reaction step or can be supplied to the first stage reactor of the polycondensation reaction step.

The polyethylene terephthalate obtained from the final polycondensation reactor in this way is usually formed into particles (chips) by a melt extrusion molding method. Such granular polyethylene terephthalate is usually 2.0 to
It is desirable to have an average particle size of 5.0 mm, preferably 2.2-4.0 mm. The granular polyethylene terephthalate that has gone through the liquid phase polycondensation step in this way is usually supplied to the solid phase polycondensation step.

The granular polyethylene terephthalate may be supplied to the solid phase polycondensation step after heating to a temperature lower than the temperature at which the solid phase polycondensation is performed to perform pre-crystallization. Such a pre-crystallization step may be performed by heating the granular polyethylene terephthalate in a dry state, for example, at a temperature of 120 to 200 ° C., preferably 130 to 180 ° C. for 1 minute to 4 hours. Terephthalate is placed in a steam atmosphere, in a steam-containing inert gas atmosphere or in a steam-containing air atmosphere, for example, 1
It may be performed by heating to a temperature of 20 to 200 ° C. for 1 minute or more.

The solid-phase polycondensation step to which such granular polyethylene terephthalate is supplied comprises at least one stage, the polycondensation temperature is usually 190 to 230 ° C., preferably 195 to 225 ° C., and the pressure is usually 1 kg. / Cm ²
The solid-state polycondensation reaction is carried out under an atmosphere of an inert gas such as nitrogen gas, argon gas, or carbon dioxide gas under the conditions of G to 10 Torr, preferably normal pressure to 100 Torr. Among these inert gases, nitrogen gas is preferred.

The intrinsic viscosity of the polyethylene terephthalate thus obtained is usually 0.50 dl / g or more, preferably 0.50 to 1.50 dl / g, more preferably 0.72 to 1.0 dl / g. Desirably. The density of this polyethylene terephthalate is usually 1.37 g.
/ Cm ³ or more, preferably 1.37 to 1.44 g / cm
³ , more preferably 1.38 to 1.43 g / cm ³ , still more preferably 1.39 to 1.42 g / cm ³ .

The polyethylene terephthalate obtained as described above has a ratio (L / T) of the flow length (L) to the flow thickness (T) when injection-molded at 290 ° C. of Y, and The intrinsic viscosity of the obtained molded product is represented by X (dl /
g), X and Y satisfy Y ≧ 647-50.
0X. Further, the titanium atom content is 1 to 1
00 ppm, particularly preferably in the range of 1 to 80 ppm, the magnesium atom content is 1 to 200 ppm,
Particularly, it is preferably in the range of 1 to 100 ppm. The weight ratio (Mg / Ti) between titanium atoms and magnesium atoms contained in the polyethylene terephthalate may be 0.01 or more, preferably 0.06 to 10, and particularly preferably 0.06 to 5. desirable. Further, when the above polycondensation catalyst (I) and, if necessary, a cocatalyst compound (II) are used as the polycondensation catalyst, the obtained polyethylene terephthalate has excellent hue and transparency,
Low acetaldehyde content and low oligomer content such as cyclic trimer in polyethylene terephthalate.

The polyethylene terephthalate thus produced may be added with conventionally known additives such as a stabilizer, a release agent, an antistatic agent, a dispersant, and a coloring agent such as a dye or pigment. These additives may be added at any stage during the production of polyethylene terephthalate, or may be added by a master batch before molding.

The polyethylene terephthalate according to the present invention can be used as a material for various molded articles. For example, it is melt molded and used for hollow molded articles such as bottles, sheets, films, fibers and the like. Is preferred.

As a method for forming bottles, sheets, films, fibers and the like from the polyethylene terephthalate obtained by the present invention, conventionally known methods can be employed.

For example, when molding a bottle, the above-mentioned polyethylene terephthalate is extruded from a die in a molten state to form a tubular parison. Then, the parison is held in a mold having a desired shape, and then air is blown into the mold. A method for producing a hollow molded article by mounting on a mold, producing a preform for a hollow molded article by injection molding from the polyethylene terephthalate, heating the preform to an appropriate stretching temperature, and then molding the preform into a mold having a desired shape There is a method of manufacturing a hollow molded body by blowing air after holding the inside of the mold and mounting the mold on a mold.

As a method for forming a film or a sheet, there is a method in which a conventionally known extruder and forming conditions are adopted and molten polyethylene terephthalate is extruded from a T-die or the like. These films or sheets may be stretched by a known stretching method.

[0083]

The polyethylene terephthalate according to the present invention has a high fluidity at the time of melting, and has a hollow molded article, a film,
Excellent moldability when molding into sheets and the like.

The preform for a hollow molded article and the hollow molded article according to the present invention are obtained from the above polyethylene terephthalate and have excellent transparency.

[0085]

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

In the examples, each characteristic was measured as follows. Intrinsic viscosity (IV) The intrinsic viscosity of the molded product was determined by preparing a 0.5 g / dl sample solution using a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (50/50 weight ratio), The intrinsic viscosity was calculated from the solution viscosity measured at 25 ° C. The intrinsic viscosity of the particulate polyethylene terephthalate is calculated from the solution viscosity measured at 25 ° C. after dissolving 1.2 g of polyethylene terephthalate in 15 cc of o-chlorophenol by heating and cooling.

As a haze raw material, 2 kg of granular polyethylene terephthalate is dried at 140 ° C. and a pressure of 10 Torr by using a tray-type dryer for 16 hours or more to reduce the water content of the granular polyethylene terephthalate to 50 ppm or less.

Next, the dried granular polyethylene terephthalate was injection-molded using an M-70A injection molding machine manufactured by Meiki Seisakusho under the conditions of a cylinder temperature of 275 ° C. and a mold cooling water temperature of 15 ° C. A plate-like molded body is manufactured.

The stepped square plate-shaped molded product was weighed for 12 seconds,
The dried granular polyethylene terephthalate is supplied from a hopper to an injection molding machine whose molding conditions are adjusted so that the injection time is 60 seconds, and molding is performed. The residence time of the molten resin in the molding machine is about 72 seconds. The resin weight used per one stepped square plate-shaped molded product was 75 g. As the haze measurement amount sample, any one of the 11th to 15th samples after the start of injection molding is used.

The stepped square plate-like molded product has a shape as shown in FIG. 1, and the thickness of the portion A is about 6.5 mm.
The thickness of the part B is about 5 mm, and the thickness of the part C is about 4 mm. In the present invention, the haze meter (Suga tester) HGM-2DP is used to measure the C
The haze of the part is measured.

[0091] Haze value at a substantially central portion of the side surface of the hollow molded body appearance blow molded containers (light diffuse reflectance of white light) was measured. This haze value (%)
, The appearance of the hollow molded article was evaluated as follows.

：: 0 ≦ haze value <5 ×: 5 ≦ haze value Flowability (L / T) Measurement Method Measured by the method described above.

[0093]

Example 1 Preparation of solid titanium compound 500 ml of deionized water in a 1000 ml glass beaker
Was weighed, and after cooling in an ice bath, 5 g of titanium tetrachloride was added dropwise with stirring. When the generation of hydrogen chloride stopped, the solution was taken out of the ice bath, and 25% aqueous ammonia was added dropwise with stirring to adjust the pH of the solution to 8. The resulting precipitate of titanium hydroxide was separated from the supernatant by centrifugation at 2500 rpm for 15 minutes. Thereafter, the obtained precipitate of titanium hydroxide was washed five times with deionized water. The solid-liquid separation after washing is 2500 rotations,
Performed by centrifugation for 15 minutes. Water was removed from the washed titanium hydroxide by vacuum drying at 70 ° C., 10 Torr and 18 hours to obtain a solid titanium compound. The obtained solid titanium compound was pulverized into particles of about 10 μm before use as a polycondensation catalyst.

The amount of water adhering to the solid titanium compound thus obtained was measured by a Karl Fischer moisture meter, and it was found that the solid titanium compound contained 6.7% by weight of water. The weight loss on heating was measured by thermogravimetry.
From 0 ° C. to 600 ° C., a further 2.17% weight loss was found, which was due to desorption of moisture and nitrogen compounds. Since nitrogen contained in the catalyst was 1.3% by weight and chlorine was contained only at 14 ppm, it is considered that nitrogen is not derived from ammonium chloride but derived from ammonia. From these, it was found that the obtained solid titanium compound had a molar ratio of titanium to hydroxyl group of 1: 0.15. Nitrogen is trace amount total nitrogen analyzer (chemiluminescence method)
The chlorine was analyzed by chromatography and calculated as ammonia and hydrogen chloride, respectively.

Next, 76.81 moles of high-purity terephthalic acid and 86.03 moles of ethylene glycol were supplied to the esterification reactor at 100 ° C. and normal pressure, and 0.1% of the solid titanium-containing compound prepared by the above method was used as a catalyst. 0045 mol were added. Next, the temperature of the reaction vessel was raised to 260 ° C., and the pressure was set to 340 in a nitrogen atmosphere under a pressure of 1.7 kg / cm ² G.
The reaction was allowed for minutes. Water generated by this reaction was constantly distilled out of the system.

Next, the whole amount in the esterification reaction tank was transferred to a polycondensation reaction tank in which the total amount was previously set to 260 ° C., and tributyl phosphate containing ethylene glycol dissolved in 6.44 mol in a concentration of 6.73 mol was further added to the reaction tank at normal pressure. Add the mole,
The temperature was raised from 260 ° C. to 280 ° C. over 60 minutes, and the pressure was reduced from normal pressure to 2 Torr.

Further, after the reaction in the polycondensation reaction tank was carried out for 108 minutes, the reaction product was taken out of the polycondensation reaction tank in a strand form, immersed in water, cooled, cut into granules with a strand cutter, and polyethylene terephthalate was obtained. Obtained. The intrinsic viscosity of this polyethylene terephthalate is 0.65 dl
/ G, and the titanium content measured by atomic absorption analysis was 28 ppm.

Further, the polyethylene terephthalate obtained by the liquid phase polymerization was transferred to a solid phase polymerization tower and crystallized at 170 ° C. for 2 hours under a nitrogen atmosphere.
Solid phase polymerization was performed for a period of time to obtain granular polyethylene terephthalate. The intrinsic viscosity of the polyethylene terephthalate was 0.825 dl / g. The haze in the C portion of the stepped square plate molded using the polyethylene terephthalate in the same manner as above was 17.8%.

Next, a hollow molded article was formed from the polyethylene terephthalate as follows. Injection molding machine M-
A preform having a diameter of 28 mm was molded at 100 C (manufactured by Meiki Seisakusho) at a cylinder set temperature of 260 ° C and a mold temperature of 10 ° C. The injection molding temperature at this time is 276
C. and a molding cycle of 54 seconds.

Next, this preform was stretch-blow-molded using a blow molding machine (model number: LB01; manufactured by CORPOPLAST) under the conditions of a stretching temperature of 110 ° C. and a blow mold temperature of 30 ° C. A hollow molded body was formed.

The appearance of the hollow molded article was evaluated as described above. Next, the fluidity (L / T) of this polyethylene terephthalate was evaluated as described above using an M-70B injection molding machine manufactured by Meiki Seisakusho. The intrinsic viscosity of the obtained L / T molded piece was measured. Table 1 shows the results.

[0102]

Examples 2 to 5 Polyethylene terephthalate was produced in the same manner as in Example 1 except that the polycondensation catalyst and the polymerization conditions were changed as shown in Table 1.

Using this, a hollow molded article was molded in the same manner as in Example 1, and the appearance was evaluated. Further, the fluidity (L / T) and the intrinsic viscosity of the L / T molded piece were measured in the same manner as in Example 1. Table 1 shows the results.

[0104]

Comparative Example 1 The same procedure as in Example 1 was carried out using polyethylene terephthalate (intrinsic viscosity was 0.825 dl / g, the catalyst species measured by atomic absorption analysis was an antimony compound, and the antimony content was 235 ppm). A hollow molded body was molded and the appearance was evaluated. Further, the fluidity (L / T) and the intrinsic viscosity of the L / T molded piece were measured in the same manner as in Example 1. Table 1 shows the results.

[0105]

Comparative Example 2 Polyethylene terephthalate (intrinsic viscosity was 0.843 dl / g, the catalytic species measured by atomic absorption analysis was an antimony compound, and the antimony content was 232 ppm) A hollow molded body was molded and the appearance was evaluated. Further, the fluidity (L / T) and the intrinsic viscosity of the L / T molded piece were measured in the same manner as in Example 1. Table 1 shows the results.

[0106]

Comparative Example 3 The same procedure as in Example 1 was carried out using polyethylene terephthalate (intrinsic viscosity was 0.778 dl / g, the catalyst species measured by atomic absorption analysis was a germanium compound, and the germanium content was 56 ppm). A hollow molded body was molded and the appearance was evaluated. Further, the fluidity (L / T) and the intrinsic viscosity of the L / T molded piece were measured in the same manner as in Example 1. Table 1 shows the results.

[0107]

Comparative Example 4 The same procedure as in Example 1 was carried out using polyethylene terephthalate (intrinsic viscosity was 0.823 dl / g, the catalyst species measured by atomic absorption analysis was a germanium compound, and the germanium content was 42 ppm). A hollow molded body was molded and the appearance was evaluated. Further, the fluidity (L / T) and the intrinsic viscosity of the L / T molded piece were measured in the same manner as in Example 1. Table 1 shows the results.

[0108]

Example 6 Preparation of solid titanium-containing compound 500 ml of deionized water in a 1000 ml glass beaker
Was weighed and dispersed by adding 0.15 g of anhydrous magnesium hydroxide. After cooling in an ice bath, 5 g of titanium tetrachloride was added dropwise with stirring. The liquid became acidic and the magnesium hydroxide dissolved. When the generation of hydrogen chloride stopped, the solution was taken out of the ice bath, and 25% aqueous ammonia was added dropwise with stirring to adjust the pH of the solution to 8. The resulting precipitate of the titanium-containing composite hydroxide was separated from the supernatant by centrifugation at 2500 rpm for 15 minutes. Thereafter, the obtained precipitate of the titanium-containing composite hydroxide was washed five times with deionized water. The solid-liquid separation after the washing was performed by centrifugal sedimentation at 2500 rpm for 15 minutes. The washed titanium-containing composite hydroxide was dried under reduced pressure at 70 ° C., 10 Torr and 18 hours to remove water, thereby obtaining a solid titanium-containing compound.

The atomic ratio of titanium to magnesium in the solid titanium-containing compound was 9 mol of magnesium atoms to 91 mol of titanium atoms. The obtained titanium-containing compound was pulverized into particles of about 10 μm before using as a polycondensation catalyst.

A polycondensation reaction, granulation and solid phase polymerization were carried out in the same manner as in Example 1 except that the solid titanium-containing compound prepared by the above method was used as the polycondensation catalyst. Using the obtained polyethylene terephthalate, a hollow molded body was molded in the same manner as in Example 1, and the appearance was evaluated. Further, the fluidity (L / T) and the intrinsic viscosity of the L / T molded piece were measured in the same manner as in Example 1. Table 1 shows the results.

As shown in Table 1, the polyethylene terephthalate according to the present invention has a higher fluidity than conventional polyethylene terephthalate, and therefore has excellent moldability, and is obtained from the polyethylene terephthalate according to the present invention. The hollow molded article has an excellent appearance similarly to a hollow molded article obtained from conventional polyethylene terephthalate.

[0112]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a perspective view showing a stepped rectangular plate-shaped molded product used for measuring haze.

Continued on the front page (72) Inventor Takeshi Omatsuzawa 6-1-2, Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Inside Mitsui Chemicals, Inc. (72) Inventor Fujitsu Ehara Waki-roku, Waki-cho, Yamaguchi Prefecture 1-2 1-2 Mitsui Chemicals, Inc. (72) Inventor Hidefumi Hori 1-2-1, Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Inside Mitsui Chemicals, Inc. (72) Inventor Kazuo Toyoda Kuga-gun, Yamaguchi Prefecture (1-2) Inventor Kensaburo Fukuya Kenzaburo 6-1-2 Waki-machi, Kuga-gun, Yamaguchi Prefecture Mitsui Chemicals, Inc. (72) Inventor Junichi Imuta 6-1-2, Waki, Waki-machi, Kuga-gun, Yamaguchi Prefecture F-term (reference) 4J029 AA03 AB01 AC01 AD01 BA02 BA03 BA04 BA05 BA08 BA10 BB04A BB05A BB12A BD07A CA02 CA06 CB04A CB05A CB06A CB10A CC06A JA03 JB131 JB171 JB181 JC573 JF071 JF121 JF131 JF141 JF151 JF161 JF181 JF221 JF231 JF261 JF281 JF321 JF331 JF341 JF361 JF371 JF373 JF421 JF431 JF441 JF471 JF511 JF541 JF561 JF571 JF581

Claims (9)

[Claims] 1. Flow length (L) when injection molded at 290 ° C.
When the ratio (L / T) between the flow rate and the fluid thickness (T) is Y, and the intrinsic viscosity of the molded article obtained by the injection molding is X (dl / g), the relation between X and Y is Y ≧ A polyethylene terephthalate having a relationship of 647-500X. 2. A method according to claim 1, wherein terephthalic acid or its ester-forming derivative and ethylene glycol or its ester-forming derivative are reacted in the presence of a polycondensation catalyst comprising a hydrolyzate (Ia) obtained by hydrolyzing a titanium halide. The polyethylene terephthalate according to claim 1, which is obtained by polycondensation. 3. A polycondensation comprising a hydrolyzate (Ib) obtained by hydrolyzing a mixture of a titanium halide and a compound of at least one element selected from elements other than titanium or a precursor of this compound. 2. The polyethylene terephthalate according to claim 1, which is obtained by polycondensing terephthalic acid or an ester-forming derivative thereof with ethylene glycol or an ester-forming derivative thereof in the presence of a catalyst. 4. A compound of at least one element selected from the above-mentioned elements other than titanium or a precursor of this compound, wherein 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, aluminum, gallium, silicon, germanium, tin, antimony and phosphorus The polyethylene terephthalate according to claim 3, which is a compound of at least one element or a precursor of the compound. 5. The polycondensation catalyst according to any one of claims 2 to 4, and (II) beryllium, magnesium, calcium, strontium, barium, boron, aluminum, gallium, manganese, cobalt, zinc, germanium. Polycondensation of terephthalic acid or its ester-forming derivative and ethylene glycol or its ester-forming derivative in the presence of a co-catalyst compound of at least one element selected from the group consisting of antimony and phosphorus 2. The polyethylene terephthalate according to claim 1, which is obtained by using the above method. 6. The polyethylene terephthalate according to claim 5, wherein said promoter compound (II) is a magnesium compound. 7. The titanium atom content is in the range of 1 to 100 ppm, and the magnesium atom content is 1 to 200 ppm.
The polyethylene terephthalate according to claim 6, wherein the weight ratio (Mg / Ti) of the titanium atom to the magnesium atom is 0.01 or more. 8. A preform for a hollow molded article obtained from the polyethylene terephthalate according to claim 1. 9. A hollow molded article obtained from the polyethylene terephthalate according to claim 1.