JP3348569B2 - Polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyester resin composition. For more details, molded materials such as bottles, sheets, films, etc. are excellent in moldability and productivity, and are excellent in various physical properties such as transparency, heat resistance, impact resistance, ultraviolet shielding property, gas barrier property, creep resistance, etc. As a suitable polyester resin composition.

[0002]

2. Description of the Related Art Polyester, especially polyethylene terephthalate (hereinafter referred to as "PET") is excellent in mechanical strength, chemical stability, transparency, hygiene and the like, and is light and inexpensive. Widely used for molded materials as sheets and containers, especially carbonated drinks, fruit juice drinks,
The growth of containers for liquid seasonings, edible oils, sake and wine is remarkable.

In recent years, attention has been focused on the safety and hygiene properties of PET, the ease of incineration, and the possibility of recycling, and molded articles conventionally made of acrylic resin, polyvinyl chloride, polystyrene, etc., such as, for example, , Extruded sheet,
Applications for squeeze containers and bottles by direct blow molding are increasing.

However, there are cases where conventional general-purpose PET cannot sufficiently cope with the above-mentioned various uses.
Many types of copolymerized polyesters or polyester resin compositions having properties close to T and having characteristic characteristics have been proposed. Among these, in recent years, polyesters containing ethylene naphthalene dicarboxylate units,
It is particularly noted as a material for a molded article having excellent physical properties such as ultraviolet shielding property, gas barrier property, stretchability and heat resistance (JP-A-63-168451, JP-A-4-23962).
4, JP-A-3-122116, JP-A-4-33125
5, JP-A-5-255492).

The polyester containing the ethylene naphthalenedicarboxylate unit may be a copolymerized polyester obtained by adding naphthalenedicarboxylic acid or a derivative thereof to a PET monomer raw material, or a polyester having a main repeating unit consisting of PET and ethylene naphthalenedicarboxylate.
It is conceivable that a composition is obtained by blending a resin as a rate unit. Among them, the latter resin composition has an advantage that a polyester having various physical properties can be easily obtained by mixing an appropriate amount of a resin containing an ethylene naphthalenedicarboxylate unit with general-purpose PET.

[0006]

However, studies on polyester resin compositions containing ethylene naphthalene dicarboxylate units are not yet sufficient at present, and in order to promote widespread practical use as molded material, There are still many issues to be solved. As a use of the polyester resin composition, molding materials such as food containers and beverage bottles are generally considered. In this case, higher productivity is required for mass production.

[0007] Further, the molding conditions of each resin component in the resin composition are apt to change due to the compatibility of each resin component, and the transparency of the molded article is easily impaired. Also, as compared with general-purpose PET, oligomers tend to be produced as by-products during molding. The oligomers adhere to and contaminate equipment such as a mold at the time of molding, and cause surface roughening and whitening of a molded article derived from the resin composition.

[0008]

In view of the above problems, the present inventors have studied the relationship between the physical properties of a polyester resin composition containing an ethylene naphthalenedicarboxylate unit and the properties of the constituent polyester component of the composition. As a result of careful examination, the present inventors have found a specific polyester resin composition in which the conventional problems are greatly improved, and have reached the present invention.

That is, the gist of the present invention is to provide a resin (a) whose main repeating unit is an ethylene terephthalate unit.
(b) a polyester resin composition comprising x weight% and y weight% of a resin (b) whose main repeating unit is an ethylene naphthalene dicarboxylate unit;
Is 5 to 95; y is 95 to 5; (2) ethylene naphthalenedicarboxylate units in the composition is 7 to 50 mol%; (3) A represented by the following formulas (I) and (II) And B
Is 25 to 130

[0010]

A = (x / 100) {[Ge] _a + (1/3) [Sb] _a +3 [Ti] _a } --- (I)

[0011]

B = (y / 100) {[Ge] _b + (1/3) [Sb] _b + 3 [Ti] _b } --- (II) In the formulas (I) and (II), [Ge ] _a, [Sb] _a,
[Ti] _a is the germanium atom content of the resin (a),
The antimony atom content and the titanium atom content are shown (unit: ppm). [Ge] _b , [Sb] _b , [T
i] _b represents the germanium atom content, the antimony atom content, and the titanium atom content in the resin (b) (unit:
ppm). (4) the sum of M and N represented by the following formulas (III) and (IV) is 0.80 or less;

[0012]

[Mathematical formula-see original document] M = (x / 100) [CT] _a --- (III)

[0013]

N = (y / 100) [OL] _b --- (IV) (Formula (I
In (II) and (IV), [CT] _a is the content of the cyclic trimer in the resin (a) (unit: wt%), and [OL] _b is the content of the oligomer in the resin (b) (unit: weight) %). )).

Hereinafter, the present invention will be described in detail. The resin (a) whose main repeating unit is an ethylene terephthalate unit (hereinafter referred to as “PET resin (a)”), which is a constituent component of the polyester resin composition of the present invention, includes general-purpose PET. And usually contains at least 80 mol%, preferably at least 90 mol%, of ethylene terephthalate units. The PET resin (a) may contain a small amount of a copolymer component, such as isophthalic acid,
Dicarboxylic acid components such as orthophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, phenylenedioxydiacetic acid, diethylene glycol, 1,4-butanediol, 2-butyl-2-ethyl-1,3-propanediol, neopentyl glycol; A diol component such as cyclohexanedimethanol can be used.

A small amount of a trifunctional or higher polyfunctional component may be copolymerized within a range not departing from the constitutional requirements of the present invention. As the trifunctional or higher polyfunctional component, known compounds generally used for PET may be used. For example, polyvalent carboxyl components such as trimellitic acid, trimesic acid, and pyromellitic acid, and trimethylolethane And polyhydric hydroxy components such as trimethylolpropane, glycerin and pentaerythritol, and glycidyl ether components of aromatic dihydroxy compounds such as bisphenol A diglycidyl ether and bisphenol S diglycidyl ether. When these trifunctional or higher polyfunctional components are used, they are usually in a range where gelation does not substantially proceed, that is, usually not more than 1.0 mol%, preferably not more than 1.0 mol%, based on all monomer unit components constituting the resin composition. It is desirable to be in the range of 0.6 mol% or less. When the polyfunctional component is copolymerized in a small amount, the degree of the drawdown of the parison at the time of extrusion blow and the degree of the drawdown of the sheet at the time of drawing the sheet tend to be smaller.

Further, a small amount of a monofunctional component may be copolymerized within a range not departing from the constitutional requirements of the present invention. Examples of the monofunctional component include benzoic acid, t-butylbenzoic acid, benzoylbenzoic acid, stearic acid, benzyl alcohol, stearyl alcohol and the like. When these monofunctional components are used, they are usually in the range of 0.005 to 1.0 mol%, preferably 0.01 to 0.75 mol%, based on all components constituting the resin composition. Is desirable. When the monofunctional component is copolymerized, it is possible to suppress an increase in oligomers and acetaldehyde when melt-molding the polyester resin composition of the present invention.

Next, a resin (b) which is an ethylene naphthalenedicarboxylate unit (hereinafter referred to as a “PEN resin (b)”) which is a constituent component of the polyester resin composition of the present invention.
") Means that the content of ethylene naphthalenedicarboxylate units is usually 50 mol% or more, preferably 80 mol% or more. The structural units other than the ethylene naphthalene dicarboxylate unit are usually composed of ethylene terephthalate units.
Similar to the resin (a), other copolymer components may be contained in a small amount.

The polyester resin composition of the present invention comprises the above-mentioned PET-based resin (a) x% by weight and a PEN-based resin (b)
y, where x is 5-95,
y is 95-5, preferably x is 10-90, y
Is 90 to 10. And, in the polyester resin composition of the present invention, the ethylene naphthalene when the mixing ratio of the PET-based resin (a) and the PEN-based resin (b) is within the range of x and y, and when the composition is melt-mixed. The dicarboxylate unit is adjusted to a range of 7 to 50 mol%, preferably 8 to 40 mol%, particularly preferably 10 to 35 mol%. When the ethylene naphthalenedicarboxylate unit is less than 7 mol%, superiority in various physical properties such as heat resistance, gas barrier property, and ultraviolet blocking property is hard to be recognized as compared with ordinary PET. On the other hand, if the amount of the ethylene naphthalenedicarboxylate unit exceeds about 50 mol%, there are problems such as difficulty in setting molding conditions and an increase in cost, which is not very suitable.

In the polyester resin composition of the present invention, the above PET resin (a) and PEN resin (b) may be mixed (blended) immediately before melt molding. Usually, molding is performed as a dry-blended resin in the form of chips or pellets, but a resin obtained by melt-kneading each resin in advance may be formed into chips or pellets.

PET resin (a) and PEN resin (b)
Is produced according to a usual method for producing a polyester resin. For the PET resin (a), terephthalic acid,
Raw materials used in known PET, such as ethylene glycol and their ester-forming derivatives, may be used.
The raw materials of the naphthalenedicarboxylic acid unit of the PEN-based resin (b) include 2,6-, 2,7-, 1,4-,
Examples thereof include naphthalenedicarboxylic acids such as 1,5- or 2,3- and esters thereof such as dimethyl and diethyl. Of these, 2,6-naphthalenedicarboxylic acid and its dimethyl ester are preferable.

As a method for polymerizing a polyester resin, for example, a direct esterification reaction is performed under pressure using terephthalic acid and / or naphthalenedicarboxylic acid, and ethylene glycol, and then the temperature is further increased and the pressure is gradually reduced, and the polycondensation is performed. There is a method to make it react. Alternatively, it can be produced by performing a transesterification reaction using terephthalic acid and / or naphthalenedicarboxylic acid, for example, a dimethyl ester derivative, and ethylene glycol, and then subjecting the obtained reaction product to polycondensation (melt polymerization). At the time of this melt polymerization, one or more metal compound catalysts of germanium, antimony and titanium are used, and the amount used is important in obtaining the physical properties of the polyester resin composition of the present invention. Will be described later.

The polyester resin obtained by the above method is formed into pellets or chips by a conventional method.
This can be used as it is as a raw material for molded products,
Both the PET resin (a) and the PEN resin (b) used in the present invention are usually further subjected to a solid phase polymerization treatment,
It is necessary to reduce the oligomer content in the resin or to adjust various physical properties such as intrinsic viscosity.

The prepolymer obtained after the polycondensation reaction is
Usually, it is obtained with a granular chip having an intrinsic viscosity of 0.4 to 0.8 dl / g. The solid-phase polymerization step in which the chips are supplied includes at least one stage, and the polymerization temperature is usually 180 to 23.
0 ° C., and in the case of an inert gas flow method, 15,000 to 1
Under any pressure conditions over a wide range of Pa, nitrogen,
It is carried out under a flow of an inert gas such as argon or carbon dioxide. The solid-state polymerization time reaches desired physical properties in a shorter time as the temperature is higher, but is usually 1 to 50 hours, preferably 5 to 50 hours.
30 hours.

The intrinsic viscosity of the polyester resin component obtained above is phenol / tetrachloroethane (weight ratio: 1).
/ L) measured at 30 ° C in a mixed solvent of
1.2 dl / g. If it is less than 0.4 dl / g, when the polyester resin is formed into a molded product, it cannot have practically sufficient strength. On the other hand, if it exceeds 1.2 dl / g, the melt viscosity becomes so high that molding becomes difficult, and the heat generated by shearing in the molding machine becomes large. Is not preferred. Such an intrinsic viscosity range is common to the PET-based resin (a) and the PEN-based resin (b), but when these are mixed to form a composition, the intrinsic viscosity of the PET-based resin (a) is particularly preferable. Is 0.6 to 1.4 dl / g,
The intrinsic viscosity of the PEN resin (b) is preferably 0.5 to
1.3 dl / g. In this case, the value obtained by subtracting the intrinsic viscosity value of the PEN resin (b) from the intrinsic viscosity value of the PET resin (a) is usually -0.1 to 0.4 dl / g, preferably 0 to 0.4 dl / g. 0.3 dl / g.

Next, the polyester resin composition of the present invention is characterized in that the metal content of the residual polymerization catalyst in the composition is in a specific range. For that purpose, in the PET resin (a) and the PEN resin (b) constituting the composition, at the time of their melt polymerization, a metal compound catalyst of at least one of germanium, antimony and titanium is contained in a specific amount. Need to be used in range.

The type and amount of the catalyst used in the PET resin (a) are within a range known in the case of ordinary PET, and include at least one metal compound of germanium, antimony, and titanium; Preferably, germanium or antimony compounds are used. The compounds of germanium, antimony, and titanium are not particularly limited, such as oxides, inorganic acid salts, organic acid salts, halides, and sulfides.Generally, germanium dioxide, antimony trioxide,
An oxide such as titanium oxide is used. The amount of the catalyst is usually from 5 to 2,000 in terms of the weight of metal atoms in all the polymerization raw materials.
ppm, preferably in the range of 10 to 500 ppm. In particular, when a germanium compound is used, the amount used is such that the content of germanium atoms in the PET resin to be produced is usually 10 to 100 ppm, preferably 25 ppm.
It is desirable to use an amount in the range of ６０60 ppm. When an antimony compound is used, the amount of the antimony compound used is such that the content of antimony atoms in the produced PET resin is usually 150 to 300 ppm, preferably 170 ppm.
It is desirable to use an amount that will be in the range of ~ 280 ppm. Further, when a titanium compound is used, the amount of the titanium compound used is usually 1 to 100 ppm, preferably 5 to 50 ppm in the PET resin to be produced.
It is desirable to use an amount that will be in the ppm range.

When the contents of germanium atoms, antimony atoms and titanium atoms are within the above ranges, the rate of oligomer reduction or solid-state polymerization at the time of solid-phase polymerization of the prepolymer, and the amount of oligomer by-products at the time of molding are reduced. This is particularly favorable because the reduction of the amount is further increased. If the amount of the catalyst is too large, the oligomer reduction rate is increased and the solid phase polymerization rate is increased, thereby improving the productivity. However, the amount of oligomers and acetaldehyde by-produced during molding tends to increase, which is not preferable. Conversely, if the amount of the catalyst is too small, the amount of oligomers and acetaldehyde by-produced during molding tends to be small, but this is not preferable because the polymerization productivity is lowered and the transparency of the molded product is lowered.

In the PET resin (a), a polymerization stabilizer may be used.
Phosphites, phosphoric acid, phosphorous acid, hypophosphorous acid,
Phosphorus compounds such as polyphosphoric acid are preferably used. The stabilizer is used in an amount of usually 10 to 1000 ppm, preferably 20 to 20 ppm, based on the weight of phosphorus atoms in the stabilizer, in the total amount of the polymerization raw materials.
Used in the range of 0 ppm. In particular, when a germanium compound is used as the polycondensation catalyst, the phosphorus atom contained in the PET-based resin is usually 0.3 to 1.5 times by weight the germanium atom contained together. It is desirable to use them in a range of 0.4 to 1.0 times. When the content of the phosphorus atom is in this range, the thermal stability of the PET-based resin is good, and the rate of reducing the oligomer tends to increase, so that it is preferable.

On the other hand, also in the PEN resin (b), a metal compound catalyst of at least one of germanium, antimony and titanium is used. Further, similarly, a polymerization stabilizer can be used. The amount of the catalyst used and the polymerization rate are almost the same as those of the PET resin (a). Further, the polymerization rate can be increased by increasing the polymerization temperature by about 10 ° C. from that of the PET-based resin (a), but care must be taken since thermal decomposition may occur partially. The polyester resin composition of the present invention is a composition obtained by mixing a PET-based resin (a) and a PEN-based resin (b), which are the metal contents of the above-mentioned residual polymerization catalyst, and the residual polymerization catalyst in the composition. Is characterized by being in the range of 25 to 130 as the sum (A + B) of A and B represented by the following formulas (I) and (II).

[0030]

A = (x / 100) {[Ge] _a + (1/3) [Sb] _a +3 [Ti] _a } --- (I)

[0031]

B = (y / 100) {[Ge] _b + (1/3) [Sb] _b +3 [Ti] _b } --- (II) In the formulas (I) and (II), [Ge ] _a, [Sb] _a,
[Ti] _a is the germanium atom content of the resin (a),
The antimony atom content and the titanium atom content are shown (unit: ppm). [Ge] _b , [Sb] _b , [T
i] _b represents the germanium atom content, the antimony atom content, and the titanium atom content in the resin (b) (unit:
ppm). )

In the polyester resin composition of the present invention, the PET resin (a) and PEN
Since the remaining polymerization catalysts affect each other due to melting and mixing of the resin (b), both the PET resin (a) and the PEN resin (b) pay attention to the amount of catalyst used, and the above (A + B)
Is 25 or more and 130 or less, preferably 30 or more and 120
The following is assumed. If (A + B) exceeds 130, the amount of oligomers and acetaldehyde by-produced during molding tends to increase, which is not preferable. Conversely, if (A + B) is less than 25, the amount of oligomers and acetaldehyde by-produced during molding tends to decrease, but the polymerization productivity decreases and the transparency of the molded body decreases. Not preferred.

Further, in the polyester resin composition of the present invention, the oligomer in the composition has the following formula (III) or (IV)
It is also characterized in that the sum (M + N) of M and N represented by is 0.80 or less, preferably 0.60 or less.

[0034]

M = (x / 100) [CT] _{a −−} (III)

[0035]

N = (y / 100) [OL] _b- (IV) (In the formulas (III) and (IV), [CT] _a is a resin (a)
The content of the cyclic trimer (unit: wt%) in [OL] _b indicates the oligomer content (unit: wt%) in the resin (b). )

The oligomer content in the PET resin (a) is 0.55% by weight or less, preferably 0.40% by weight, as the content of the cyclic trimer which is the main component of the oligomer.
% By weight or less. Generally, the lower the content of the cyclic trimer, the less the contamination of the mold and the like.

The PEN resin (b) of the present invention
The oligomer in the above refers to a chain or cyclic low molecular compound in which ethylene naphthalenedicarboxylate units, which are the main components of the oligomer, are dimerized to pentamer, and the total amount is defined as the oligomer content. The oligomer content in the PEN-based resin (b) is 1.0% by weight or less, preferably 0.7% by weight or less, as the content of the cyclic trimer, which is the main component of the oligomer. In general, the lower the oligomer content, the less contamination of the mold and the like.

In the polyester resin composition of the present invention, when the above (M + N) is more than 0.80, not only contamination of a mold and the like becomes remarkable, but also transparency of a molded article is lowered, Alternatively, the heat resistance of the molded article tends to decrease, and the degree of improvement in heat resistance due to the heat setting effect when the stretched molded article is heat-set is also not preferable.

Further, the polyester resin composition of the present invention defines the range of the amount of the residual catalyst metal and the amount of the oligomer as described above. Since the content of acetaldehyde in the molded body at the time of
It is very preferable to use a molded article made of the present polyester resin composition as a packaging material that comes into direct contact with food, because the content does not change in taste or odor. The acetaldehyde in the polyester resin composition of the present invention has a sum of S and T represented by the following formulas (V) and (VI) (S + T) of usually 6.5 or less, preferably 6.0 or less, particularly preferably. 5.0 or less.

[0040]

S = (x / 100) [ALD] _a --- (V)

[0041]

T = (y / 100) [ALD] _b --- (VI) (In the formulas (V) and (VI), [ALD] _a is the acetaldehyde content (unit: ppm) in the resin (a). ),
[ALD] _b indicates the acetaldehyde content (unit: ppm) in the resin (b). )

The content of acetaldehyde in the present invention is the amount of acetaldehyde obtained by extracting a polyester resin sample with water at 160 ° C. for 2 hours. The acetaldehyde content in the molded article composed of the polyester resin composition,
Usually, it can be suppressed to the range of 0 to 50 ppm, particularly 0 to 40 ppm.

The above-mentioned polyester resin composition of the present invention may contain an antioxidant such as a hindered phenol type, a phosphorus type or a thioether type, and a coloring agent such as titanium dioxide, without departing from the constitutional requirements of the present invention. , Nucleating agents such as talc, lubricants such as calcium carbonate and silica, as well as release agents, flame retardants, heat stabilizers, hydrolysis stabilizers, antistatic agents, hard coat agents, ultraviolet absorbers, light stabilizers, and fluorescent light An additive such as a whitening agent may be appropriately contained. These additives are intact during the production of the resin composition of the present invention,
Alternatively, it may be added in the form of a master batch, or may be added at the time of molding. Further, these additives may be used for surface treatment of the molded article by a method such as coating or lamination.

The polyester resin composition of the present invention thus obtained can be formed into containers, sheets, films and the like by using a melt molding method generally used for PET. In addition, the PET resin (a) and the PEN resin (b) may be brought into contact with heated water or steam before the above polyester resin composition or before the composition is formed. According to the contact treatment, by deactivating at least a part of the residual metal catalyst in the resin,
It is possible to suppress by-products of oligomers and acetaldehyde during molding. As a method of the contact treatment, the resin may be usually immersed in water at about 40 to 120 ° C., or similar heated steam may be brought into contact with the resin. In addition, since the contact treatment itself increases the number of manufacturing steps,
A method in which only the N-based resin (b) is subjected to contact treatment with water or steam is particularly suitable.

Next, when a container is produced using the polyester resin composition of the present invention, the method employed for a general PET container is applied as it is. For example, a preform (hereinafter, referred to as "preform") is once formed by injection molding or extrusion molding. A biaxial stretch blow molding method such as a cold parison method is applied as it is or after processing the plug portion and the bottom portion and reheating it. In this case, the molding temperature, specifically, the temperature of each part of the cylinder and the nozzle of the molding machine is usually in the range of 250 to 300 ° C. The stretching temperature is usually 85 to 140 ° C, preferably 90 to 12 ° C.
At 0 ° C., the stretching ratio is usually 1.
It is performed at about 2 to 10 times.

The obtained hollow container can be used as it is, but in the case of a content liquid that requires hot filling such as a fruit juice beverage, oolong tea, etc., it is generally heat-fixed in a blow mold. Used with heat resistance. Heat fixation is usually performed under tension by compressed air, usually 120 to 2
It is performed at 00 ° C. for several seconds to several minutes. In the case of producing a container using the polyester composition of the present invention, in the hot parison method, a preform molded by an extrusion molding machine or an injection molding machine is blow-molded before it is still soft and has not lost plasticity. It is also possible to employ a direct blow molding method for completing the process or an extrusion molding method for obtaining a pipe-shaped product. In this case, the molding temperature is such that the temperature of each part of the cylinder and the nozzle is usually 240 to 300C.

On the other hand, a stretched film made of the polyester resin composition of the present invention can be obtained by subjecting a sheet obtained by injection molding or extrusion molding to uniaxial stretching, sequential biaxial stretching, simultaneous biaxial stretching which is usually used for PET stretching. It is formed using any stretching method among axial stretching. Further, it can be formed into a cup shape or a tray shape by pressure forming or vacuum forming. When producing a stretched sheet or film, the stretching temperature is usually 70 to 170 ° C, preferably 80 to 140 ° C. The stretching may be uniaxial or biaxial, but is preferably biaxial in view of practical physical properties of the film. The stretching ratio is usually in the range of 1.1 to 10 times in the case of uniaxial stretching, and is usually in the range of 1.1 to 8 times in both the longitudinal and transverse directions in the case of biaxial stretching. Just do it. Further, the vertical / horizontal magnification is usually 0.5 to 2. Also,
The obtained stretched film is further heat-set, heat-resistant,
It can also improve mechanical strength. Heat setting is usually
It is performed under tension at 120-200 ° C. for several seconds to several minutes.

When a transparent sheet is produced using the resin composition of the present invention, the transparent sheet can be produced by a melt molding method conventionally used for forming a sheet of PET or polystyrene. Extrusion molding, injection molding, press molding and the like are used as these melt molding methods.

For example, when a transparent sheet is produced by extrusion cast molding, usually, a raw resin composition is supplied to a hopper of a single-screw or twin-screw extruder to which a T-die is connected via a gear pump, and the extrusion is performed. It can be manufactured by melting in a cylinder of a machine, extruding it from a T-die into a sheet, and cooling it by a casting roll. In this case, the molding temperature, specifically, the temperature of each part of the extruder cylinder, the gear pump, and the T-die is usually 250 to 320 ° C, preferably 260 to 300 ° C. The surface temperature of the casting roll is usually 15 to 70 ° C, preferably 20 to 60 ° C.
Should be controlled.

The extruder used for extrusion casting may or may not have a vent port in the cylinder. Except when the raw resin composition is immediately after the crystallization treatment or immediately after the solid-phase polymerization treatment, since it generally contains hundreds to thousands of ppm of water, when using an extruder without a vent port In order to prevent the hydrolysis of the resin composition in the cylinder, the raw resin composition is dried to a water content of usually 100 ppm or less, preferably 50 ppm or less, and then supplied to the hopper. When an extruder having a vent port is used, the inside of the cylinder is depressurized from there, and the resin composition can be substantially dried in the cylinder. Therefore, the raw material resin composition can be supplied without drying, and the raw material can be supplied. It is also possible to further reduce volatile impurities such as acetaldehyde contained in the resin composition in the cylinder. Normal vent port is 0-7000
Pa, preferably 0 to 3000 Pa, particularly preferably 0 Pa
It is used by connecting to a reduced pressure system of up to 700 Pa. When a twin-screw extruder is used, the screw may be any of a meshing type, a non-meshing type, and an incomplete meshing type.

For the T-die, the direction of discharge of the melt from the lip may be horizontal or vertical. Further, an auxiliary device such as a filter or a sampling valve may be connected between the T-die and the extruder. As for the casting roll, it is desirable to have a contact device such as an electrostatic contact device or a touch roll. The transparent sheet is finally obtained by cutting both ends of the sheet with a trimming cutter after passing through a casting roll, and then winding it into a roll or cutting it into a panel.

The thickness of the transparent sheet thus obtained is usually 0.1 to 2 mm. More specifically, the optimal thickness of the transparent sheet is determined by the design of the molded product, that is, the size, thickness, shape, weight, mechanical properties, and the degree of deformation in processing (for example, the drawing ratio in drawing) of the molded product to be manufactured. It depends on the situation. In general, a raw sheet for a drawn molded article or a blow molded article used as a packaging material has a thickness of usually 0.1 to 2 mm, preferably 0.15 to 2 mm.
It is 1.5 mm, particularly preferably 0.2-1.2 mm. Regarding the transparency of the transparent sheet, the haze value measured in the thickness direction of the sheet is 0 to 6%, preferably 0 to 4%.
%, Particularly preferably 0 to 2%. When the haze value exceeds 6%, whitening of the molded article is clearly observed.

In drawing the transparent sheet, any method conventionally known as a drawing method for a polyester sheet may be used. Examples of the drawing method include vacuum forming, pressure forming, snapback forming, levers draw forming, air slip forming, plug assist forming, and a processing method combining these, and the like. Is also good. The processing temperature is usually 80 to 150 ° C, preferably 90 to 1 ° C, as the sheet temperature.
The temperature is 40 ° C. and the drawing ratio is usually 0.01 to 10 times, preferably 0.05 to 5 times. Regarding the sheet temperature, the temperature may be different between the surface of the sheet and the inside of the sheet, but it is preferable that the processing is performed so that all the portions to be processed are within the above temperature range. Further, it is generally desirable that the sheet temperature be such that temperature unevenness in the thickness direction is reduced as much as possible.

At the time of blowing, the sheet temperature is usually set to 80 to 150 ° C., preferably 90 to 140 ° C.
It is blown into a predetermined mold to have a shape along the mold. In this case, for example, the blowability can be improved by mechanically extending the sheet in a direction perpendicular to the sheet surface by a rod at the start of blowing. In addition, by forming the mold as a split movable mold as exemplified by a stretch blow mold for a PET bottle, it is possible to obtain a molded body having an opening smaller than the cross section of the main body. Regarding the sheet temperature, the temperature may be different between the surface of the sheet and the inside of the sheet, but it is preferable that the processing is performed so that all the portions to be processed are within the above temperature range. Further, the sheet temperature is generally preferably set so that temperature unevenness in the thickness direction is reduced as much as possible. A drawn molded article using the polyester resin composition of the present invention is suitable as a transparent material such as a packaging material exposed to a high-temperature, high-humidity environment. These packaging materials include, for example, food packaging trays and cups for side dishes, fruits, dumplings, tea bags, etc., and their lids, industrial trays used for packaging electronic components, etc., toothbrushes, headphones, etc. Blister package, packaging cases for gifts and character goods, and the like. Usually, these packaging materials are formed from a molded product obtained by three-dimensional processing such as drawing or blowing, and the thickness thereof is usually 0.05 to 1.5.
mm.

[0055]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. Various measurement methods used in this example are shown below. The measuring method of the intrinsic viscosity is as described above. (1) Cyclic trimer content (hereinafter referred to as “CT amount”) 200 mg of PET resin (a)
It was dissolved in 2 ml of a mixed solution of hexafluoroisopropanol (volume ratio: 3/2), and further diluted with 20 ml of chloroform. To this, 10 ml of methanol was added to reprecipitate the sample, followed by filtration to obtain a filtrate. After the filtrate was dried, the residue dissolved in 25 ml of dimethylformamide was analyzed and quantified by liquid chromatography.

(2) Oligomer content (hereinafter referred to as “OL amount”)
200 mg of a PEN-based resin (b) sample was added to chloroform /
It was dissolved in 2 ml of a mixed solution of hexafluoroisopropanol (volume ratio: 3/2), and further diluted with 20 ml of chloroform. To this, 10 ml of methanol was added to reprecipitate the sample, followed by filtration to obtain a filtrate. After the filtrate was dried, the residue dissolved in 25 ml of dimethylformamide was analyzed and quantified by liquid chromatography. (3) Content of germanium atom, antimony atom, and titanium atom (hereinafter referred to as “Ge amount”, “Sb amount”, “Ti amount”) 2.0 g of a polyester resin sample was incinerated by a conventional method in the presence of sulfuric acid, and completely incinerated. After decomposition, the volume was adjusted to 100 ml with distilled water and quantified by emission spectroscopy.

(4) Acetaldehyde content (hereinafter referred to as “A
After extracting with water at 160 ° C. for 2 hours, the amount was determined by gas chromatography. (5) Haze The haze of the polyester molded article was measured according to JIS K-7105.

[Production of PET Resin (a)] A predetermined amount of a slurry of terephthalic acid and ethylene glycol is prepared,
The solution was sequentially supplied to the esterification tank maintained at 250 ° C. over 4 hours. After the completion of the supply, the esterification reaction was further allowed to proceed at 250 ° C., and then half was transferred to a polycondensation tank, and a predetermined amount of a catalyst (any of germanium dioxide, antimony trioxide, and titanium dioxide) was charged. The temperature was gradually raised to ° C., and the pressure was gradually reduced from normal pressure, and the pressure was maintained at 70 Pa. After performing the polycondensation reaction, the resulting prepolymer was drawn out in a strand shape from a discharge port provided at the bottom of the polycondensation tank, cooled with water, and cut into chips. The prepolymer chips were mixed with a stirring crystallization machine (Bepex) for 14 minutes.
After pre-crystallization at 0 ° C, it was transferred to a stationary solid-state polymerization tower,
After drying at about 140 ° C. for 3 hours under a nitrogen flow of 20 liters / kg / hr, the solid phase polymerization is performed at 210 ° C. to obtain PE.
A chip of the T-based resin (a) was obtained. By adjusting the amount of the catalyst used for the polycondensation reaction, the polycondensation reaction time, the solid phase polymerization time, etc., PET resins (a) 1 to 9 shown in Table 1 were obtained.

[0059]

[Table 1]

[Production of PEN Resin (b)] A predetermined amount of a slurry of 2,6-naphthalenedicarboxylic acid and ethylene glycol was prepared and supplied to the esterification tank maintained at 250 ° C. over 4 hours. After supply is completed, another 25
After the esterification reaction was allowed to proceed at 0 ° C., half of the mixture was transferred to a polycondensation tank, and a predetermined amount of a catalyst (any of germanium dioxide, antimony trioxide, and titanium dioxide) was charged.
The temperature was gradually raised from 280 ° C. to 280 ° C., and the pressure was gradually reduced from normal pressure to 70 Pa. After performing the polycondensation reaction, the resulting prepolymer was drawn out in a strand shape from a discharge port provided at the bottom of the polycondensation tank, cooled with water, and cut into chips. The prepolymer chips are stirred and crystallized (B
After pre-crystallization at 140 ° C. using epex formula),
It was transferred to a stationary solid-state polymerization tower, dried at about 140 ° C. for 3 hours under a nitrogen flow of 20 L / kg / hr, and then subjected to solid-state polymerization at 210 ° C. to obtain a PEN-based resin (b) chip. By adjusting the amount of the catalyst used for the polycondensation reaction, the polycondensation reaction time, the solid-phase polymerization time, etc., the P shown in Table 1 can be adjusted.
EN resins (b) 11 to 16 were obtained.

[0061]

[Table 2]

Examples 1 to 5 and Comparative Examples 1 to 4 The resin chips obtained as described above were dry-blended at a predetermined ratio, and then dried at 140 ° C. under vacuum conditions using a vacuum dryer.
Dried for 2 hours. Using the dried chip mixture as a resin composition for molding, a cylinder type injection molding machine (ASB-50TH type, manufactured by Nissei ASB Machine Co., Ltd.) was used. The cylinder temperature was 285 ° C., the mold temperature was 20 ° C., and the screw rotation speed was 10
0 rpm, injection time 14 seconds, cooling time 8 seconds, injection pressure 4
Under a condition of 0 to 120 kg / cm ^2, a preform having an outer diameter of 30 mm, a length of 145 mm, and a wall pressure of 4 mm is formed, and this is approximately twice in the axial direction, approximately three times in the circumferential direction, and approximately six times in area magnification.
The bottle was stretched twice to continuously form a bottle having a total height of 300 mm, a body outer diameter of 80 mm, a body thickness of 0.35 mm, and an internal volume of about 1500 ml. Product evaluation was performed on the 470th to 500th bottles. Table 3 shows the evaluation results (average values).

[0063]

[Table 3] Note 1) EN unit: ethylene naphthalene dicarboxylate unit (mol%)

Examples 6 to 9 and Comparative Examples 5 to 6 After the resin chips obtained as described above were dry-blended at a predetermined ratio, the resin chips were dried at 140 ° C. under a vacuum condition at 140 ° C. using a vacuum dryer.
Dried for 2 hours. Using the dried chip mixture as a resin composition for molding, a cylinder type injection molding machine (ASB-50TH type, manufactured by Nissei ASB Machine Co., Ltd.) was used. The cylinder temperature was 285 ° C., the mold temperature was 20 ° C., and the screw rotation speed was 10
0 rpm, injection time 14 seconds, cooling time 8 seconds, injection pressure 4
Under a condition of 0 to 120 kg / cm ^2, a preform having an outer diameter of 30 mm, a length of 145 mm, and a wall pressure of 4 mm is formed, and this is approximately twice in the axial direction, approximately three times in the circumferential direction, and approximately six times in area magnification.
The bottle was stretched twice to continuously form a bottle having a total height of 300 mm, a body outer diameter of 80 mm, a body thickness of 0.35 mm, and an internal volume of about 1500 ml. Product evaluation was performed on the 470th to 500th bottles. Table 4 shows the evaluation results (average values).

[0065]

[Table 4] Note 2) EN unit: ethylene naphthalene dicarboxylate unit (mol%)

Examples 10 to 13 and Comparative Examples 7 to 8 As shown in Table 5, after the resin chips were dry-blended at a predetermined ratio, Nippon Steel Works to which a gear pump, a filter, a T-die and the like were connected as a sheeting device. Using a TEX65 model twin-screw extruder (with vent port), extruded under the conditions of a set temperature of 295 ° C and a vent port internal pressure of 1 mmHg or less, via a casting roll (with a touch roll) with a surface temperature of 40 ° C. Winding, thickness 60
A 0 μm transparent sheet was formed. Table 4 shows the physical property values of the transparent sheet.

Next, the transparent sheet was vertically oriented using a plug-assist type vacuum pressure molding machine manufactured by Asano Laboratories under the conditions of a sheet heating time of 5 seconds, a sheet surface temperature of 115 ° C., and a mold temperature of 40 ° C. It is a rectangle of 11 cm and a width of 14 cm, the upper end opening is a rectangle of 12.5 cm in length and 15.5 cm in width, and a truncated quadrangular pyramid shape having a height of 3 cm (aperture ratio = 0.24). Width 5 adjacent to the outside of the part
The sheet was drawn into a tray having a flat flange part of mm. This tray molding was performed continuously. 470-500
The haze value was measured for the bottom surface of the tray. Table 5 shows the evaluation results (average values).

[0068]

[Table 5] Note 2) EN unit: ethylene naphthalene dicarboxylate unit (mol%)

[0069]

EFFECT OF THE INVENTION The polyester resin composition of the present invention has excellent moldability, productivity, transparency, heat resistance, impact resistance,
It is suitable as a molding material for bottles, sheets, films, etc., having excellent physical properties such as ultraviolet blocking properties, gas barrier properties, and creep resistance. The molded article using the polyester resin composition of the present invention has a feature that it is less likely to be deformed even when exposed to a high-temperature and high-humidity environment for a long time, for example, as compared with a conventional general-purpose PET molded article. Therefore, the polyester resin composition of the present invention has a great possibility of being used as a material that does not reach the target physical properties with general-purpose PET, for example, a heat-resistant bottle, a heat-resistant pressure-resistant bottle, a material for use in a repeatedly usable returnable bottle, and the like. It is. Further, by using the polyester resin composition of the present invention as a raw material of a raw sheet to be subjected to drawing or blow processing, etc., when roll dirt or sheet is drawn or blow-processed at the time of sheet forming by oligomers, Mold contamination can be reduced, and excellent transparency can be obtained, and when used as a packaging material, a molded product having no unpleasant taste or smell transfer in the content can be manufactured with high productivity. Furthermore, when a drawn container is obtained by molding the polyester resin composition of the present invention, the wet heat deformation resistance and the transparency are improved as compared with a three-dimensional molded body using a conventional general-purpose PET sheet, and It is excellent in impact resistance, chemical resistance, thermal stability, gas barrier properties, ultraviolet shielding properties, heat sealing properties, recyclability, etc., and can provide a thick three-dimensional molded article having high transparency and thickness.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 67/02 C08J 5/00 C08J 5/18

Claims (11)

(57) [Claims] 1. A polyester resin composition comprising a resin (a) whose main repeating unit is an ethylene terephthalate unit x weight% and a resin whose main repeating unit is an ethylene naphthalene dicarboxylate unit (b) y weight%. (1) The above x is 5-95 and y is 95-
5, (2) the ethylene naphthalenedicarboxylate unit accounts for 7 to 50 mol% of the composition, (3) the sum of A and B represented by the following formulas (I) and (II) is 25 to 130, A = (x / 100) {[Ge] _a + (1/3) [Sb] _a +3 [Ti] _a } --- (I) B = (y / 100)} [Ge] _b + (1/3) [Sb] _b +3 [Ti] _b } (II) In the formulas (I) and (II), [Ge] _a , [Sb] _a ,
[Ti] _a is the germanium atom content of the resin (a),
The antimony atom content and the titanium atom content are shown (unit: ppm). [Ge] _b , [Sb] _b , [T
i] _b represents the germanium atom content, the antimony atom content, and the titanium atom content in the resin (b) (unit:
ppm). (4) The sum of M and N represented by the following formulas (III) and (IV) is 0.80 or less, and M = (x / 100) [CT] _a --- (III) N = (y / 100) [OL] _b- (IV) (In the formulas (III) and (IV), [CT] _a is a resin (a)
The content of the cyclic trimer (unit: wt%) in [OL] _b indicates the oligomer content (unit: wt%) in the resin (b). A) a polyester resin composition; 2. The polyester resin composition according to claim 1, wherein the ethylene terephthalate unit of the resin (a) is at least 80 mol%. 3. The polyester resin composition according to claim 1, wherein the resin (b) has 50 mol% or more of ethylene naphthalenedicarboxylate units. 4. The resin (a) having an intrinsic viscosity of 0.6 to 1.4.
dl / g, and the intrinsic viscosity of the resin (b) is 0.5 to 1.
4. The polyester resin composition according to claim 1, wherein the amount is 3 dl / g. 5. The polyester resin composition according to claim 1, wherein the sum of S and T represented by the following formulas (V) and (VI) is 6.5 or less. S = (x / 100) [ALD] _{a −−} (V) T = (y / 100) [ALD] _{b −−} (VI) (Formula (V), (VI) )), [ALD] _a is the acetaldehyde content (unit: ppm) in resin (a), [ALD]
D] _b indicates the acetaldehyde content (unit: ppm) in the resin (b). ) 6. A polyester resin container obtained by forming a preform from the polyester resin composition according to claim 1 by injection molding or extrusion molding and then biaxially stretch blow molding. 7. A polyester sheet obtained by subjecting the polyester resin composition according to claim 1 to injection molding or extrusion molding. 8. The sheet according to claim 7, having a thickness of 0.1 to 2 mm. 9. A drawn drawn product made of polyester obtained by drawing the sheet-like material according to claim 7 or 8. 10. A blow molded article made of polyester obtained by subjecting the sheet material according to claim 7 to blow processing. 11. A stretched polyester film obtained by stretching the sheet material according to claim 7 or 8 in at least one direction.