JPH10120802A - Polyester sheet and packaging container produced by fabricating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester sheet which has a greatly improved cuttability and can be fabricated at remarkably improved productivity without detriment to the clarity, printability, and adhesiveness and to provide a packaging container produced by fabricating the same. SOLUTION: This polyester sheet is formed from a dicarboxylic acid component mainly comprising terephthalic acid and a diol component mainly comprising ethylene glycol and has such characteristics that the intrinsic viscosity is 0.60dl/g or higher, that the difference in temp.-rise crystallization temp. ΔTc1 determined by the formula: ΔTc1 =|Tc1 '-Tc1 | (wherein Tc1 is the crystallization peak temp. in temp. rise; and Tc1 ' is the temp.-rise crystallization peak temp. measured after heating at 285 deg.C for 3min, quenching, and raising the temp. again) is 10 deg.C or lower, and the haze measured in the thickness direction is 5% or lower. The sheet is subjected to punching, bending, and assembly to give a package container.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to transparency, printability,
The present invention relates to a polyester sheet having improved cutability without impairing adhesiveness and the like, and a sheet and a packaging container obtained by processing the same.

[0002]

2. Description of the Related Art Saturated polyesters, especially polyethylene terephthalate (hereinafter sometimes abbreviated as "PET").
Is widely used for fibers, films and bottles. In recent years, an amorphous unstretched sheet called an A-PET sheet has been used for its excellent color, food safety, low pollution, and recyclability. It is attracting attention as a packaging material that can replace vinyl and polystyrene. A-PET sheet is
Usually, it is used as a blister package for food, miscellaneous goods, etc. by molding. Examples of the molding method include a method of drawing by heating and a method of forming a ruled line and bending.

[0003] In particular, when the sheet is subjected to bending, it is efficient to stack a predetermined number of sheets and cut the sheets into a desired shape at a stretch. Such a prescription is applied to a sheet of vinyl chloride or the like. However, in the case of A-PET, the adhesiveness between the sheets is high and blocking occurs,
There has been a problem that cracks occur in the sheets when they are cut and stacked due to the embrittlement of the sheets and the like. For this reason, it is difficult to use the A-PET sheet as a single sheet as used in vinyl chloride, and improvement is desired.

[0004] There have been many proposals for improving the slipperiness of the sheet to prevent blocking. For example,
JP-A-50-45885, JP-A-4-13606
As described in JP-A No. 3 and JP-A-4-180957, there is a method in which inert particles are added during polymerization or sheet formation. However, a substantially non-stretched sheet has insufficient slipperiness, and it is necessary to increase the particle diameter of the particles or increase the blending amount of the particles in order to impart sufficient slipperiness. For this reason, the transparency and mechanical properties of the sheet are reduced, which is a problem.

Further, as described in JP-B-44-8759 and JP-A-60-61259, fine powder is sprayed on the surface of a sheet, or a coating film having lubricity is applied or printed. However, these methods are difficult to apply evenly, and thus are likely to cause poor appearance. Further, a method of applying silicon on the surface of the sheet is also widely used, but causes a decrease in heat sealability, printability, adhesiveness, applicability, etc., and may also cause poor appearance, and is used in some applications. Limited.

As means for improving these, Japanese Patent Application Laid-Open No.
No. 60924 and JP-A-8-142293 propose a method of co-adding an inert particle and a fatty acid ester to a surface layer. According to this method, the slipperiness of the sheet is remarkably improved, but when a predetermined number of sheets are stacked and cut, cracks still occur, and a drastic improvement is desired.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a polyester sheet which has a particularly improved cutting property while maintaining the conventional transparency, printability and adhesiveness, and can significantly improve the productivity during processing. It is another object of the present invention to provide a packaging container obtained by processing the same.

[0008]

Means for Solving the Problems As a result of intensive studies in view of the above-mentioned circumstances, the present inventors have surprisingly found that the use of a polyester having a specific physical property value, particularly a specific crystallinity, makes it possible to surprisingly improve the sheet cutting property. It has been found that the improvement is remarkable, and the present invention has been reached. That is, the gist of the present invention is a polyester sheet comprising a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol, having an intrinsic viscosity of 0.60 dl / g or more and the following formula (1). Temperature crystallization temperature difference Δ
A polyester sheet having a T _c1 of 10 ° C. or less and a haze measured in a thickness direction of 5% or less, and a packaging container obtained by processing the polyester sheet.

[0009]

[Number 2] _{ΔTc1 = | T c1 '-T c1} | ......... (1) ( however, T _c1 in the formula is the crystallization peak temperature of during heating, T _c1' was held for 3 minutes at 285 ° C. Shows the crystallization peak temperature when the temperature is raised rapidly after rapid cooling.)

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
First, the polyester constituting the sheet of the present invention will be described. The composition of the polyester constituting the sheet of the present invention is mainly composed of a terephthalic acid component and an ethylene glycol component when viewed as the entire sheet (that is, the entire multilayer sheet in the case of a multilayer structure described later), and is based on the total dicarboxylic acid component. The ratio of terephthalic acid component is usually 8
0 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, and the ratio of the ethylene glycol component to all diol components is usually 80 mol% or more,
It is preferably at least 85 mol%, more preferably at least 90 mol%.

When the composition of the polyester constituting the sheet of the present invention is in the above-mentioned range, the raw material is inexpensive, the sheet can be easily formed and molded, and the bending strength and the resistance when formed into a sheet shape can be improved. It is preferable because physical properties such as chemical property and weather resistance are excellent. Examples of the copolymerization components (components other than terephthalic acid and ethylene glycol) of the polyester constituting the sheet of the present invention include, for example, diphthalic acid components such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, p -Oxyethoxybenzoic acid and the like. As the diol component, diethylene glycol, 1,4 and 1,3-cyclohexanedimethanol, propylene glycol, 1,4-
Butanediol, 1,2-neopentyl glycol, bisphenol A and the like. In addition, as long as the effect of the present invention is not impaired, components having three or more functionalities may be copolymerized.

A particularly preferable polyester composition for achieving the object of the present invention is that ethylene terephthalate units contain diethylene glycol and / or cyclohexane dimethanol (hereinafter sometimes abbreviated as "DEG" and "CHDM", respectively). Copolymers may be mentioned. The copolymerization amount of these copolymer components is not particularly limited as long as they have crystallinity as a bulk and satisfy the constitutional requirements of the present invention, but the copolymerization amount of DEG is 5 mol% or less based on all diol components. And 1 to 4 mol%, and the copolymerization amount of CHDM is 2 to 20 mol% based on all diol components.
More preferably, it is 3 to 15 mol%.

Next, the layer structure of the polyester sheet of the present invention will be described. The polyester sheet of the present invention,
It may have a single-layer structure or a multilayer structure represented by one type, three layers, two types, three layers, and the like. Of these, a multilayer structure is preferable, and a multilayer structure of two or three layers is more preferable. When a multilayer structure of two and three layers is used, for example, in the core layer (A), diol components other than ethylene glycol in all diol components are 5 mol% or less, further 4 mol% or less,
In particular, the skin layer (B) is preferably composed of 3 mol% or less of PET, and the skin layer (B) contains 3 to 50 mol%, more preferably 10 to 45 mol%, particularly 15 to 40 mol% of diol components other than ethylene glycol in all diol components. It is preferably made of copolymerized PET which is mol%.

When the copolymerization amount of the core layer (A) is within the above range, the sheet of the present invention is more excellent in cutability, impact resistance, moldability, and the like, and is more preferable. Also, the skin layer (B)
When the copolymerization amount is within the above range, the sheet of the present invention is more excellent in cutability, solvent resistance, adhesiveness, bending workability, and the like, and therefore is more preferable. When the polyester used for the polyester sheet of the present invention contains one or more copolymer components of DEG and CHDM, the polyester sheet of the present invention easily exhibits excellent physical properties such as impact resistance and moldability. It is more preferable. The use of CHDM copolymerized PET for the skin layer (B) is more preferable because the sheet of the present invention can easily exhibit excellent properties such as excellent adhesiveness and moldability.

Incidentally, polycarbonate, polyolefin, polyamide and the like may be blended as long as the physical properties of the sheet of the present invention are not impaired. The amount is preferably at most 30% by weight, more preferably at most 10% by weight. The total thickness of the skin layer (B) is 1 to 30%, more preferably 5 to 20%, especially 8 to 10% of the thickness of the entire sheet.
It is desirable to be 15%. When the thickness of the skin layer (B) is in this range, the sheet of the present invention is excellent in cutability, moldability, and the like, and is therefore more preferable.

The intrinsic viscosity of the polyester constituting the sheet of the present invention is 30 when dissolved in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (weight ratio = 1/1).
The intrinsic viscosity is 0.60 dl / g or more when measured at ℃,
It is preferably 0.65 dl / g or more, more preferably 0.68 dl / g or more, and usually 1.30 dl / g.
It is as follows. When the intrinsic viscosity is less than 0.60 dl / g,
It is not preferable because the mechanical properties of the obtained sheet, particularly the impact resistance, are poor. Further, a sheet having an intrinsic viscosity of more than 1.30 dl / g tends to be inferior in sheet formability since the melt fluidity at the time of sheeting is inferior.

When the sheet of the present invention has a multilayer structure, it is preferable that the intrinsic viscosity of the polyester constituting each layer is 0.60 dl / g or more. The raw material polyester of the sheet of the present invention is produced by melt polymerization and, if necessary, solid phase polymerization in order to obtain a polyester having desired physical properties, according to a known method. The catalyst used for the polymerization is not particularly limited, such as germanium, antimony, titanium, and cobalt compounds. Preferably, a germanium compound is used as the polymerization catalyst.

As the raw material polyester, as long as the effects of the present invention are not impaired, a recycled polyester produced in the process or the like may be blended, which not only reduces costs but also reduces waste. This is also preferable. The amount is preferably 5 to 50% by weight, more preferably 10 to 40% by weight, based on the polyester sheet of the present invention. As a method of blending the recycled polyester without impairing the physical properties such as the appearance of the sheet, a method in which the sheet is multilayered and a layer in which the recycled product is blended is set in the inner layer portion is preferably adopted.

The oligomer content of the raw material polyester is 5% as the content of the cyclic trimer as its main component.
It is desirable that the content is not more than 3% by weight, more preferably not more than 3% by weight. When the content of the cyclic trimer exceeds 5% by weight, for example, it adheres to a dice or a roll during sheeting and becomes contaminated, and the surface properties of the obtained sheet may be impaired or the appearance may be poor. Further, as a preferred method, the sheet of the present invention has a multilayer structure, and a skin layer is made of a raw material having a particularly low oligomer content, for example, copolymerized PET having a copolymerization component of 15 mol% or more, or solid phase polymerization. PE
There is a method using T.

The values of the above-mentioned copolymer components, their amounts, intrinsic viscosity and oligomer content are generally in the same range between the raw material polyester and after the sheet is formed into a sheet. The sheet of the present invention may contain various additives, for example, a lubricant, an antistatic agent, in order to obtain aesthetics, weather resistance, lubricity, antistatic properties, etc. of the sheet itself or a molded product obtained by further molding the sheet. Agent, anti-blocking agent, fluorescent agent,
An ultraviolet absorber, a flame retardant, a colorant, and the like may be blended or applied. Such a method is not particularly limited. For example, a master batch in which additives are dispersed at a high concentration may be used, or a solution may be dissolved or dispersed in a solvent and applied. Further, various surface treatments may be performed for the purpose of preventing the surface from being damaged or preventing static charge.

When these additives are blended, they may be blended uniformly in the whole sheet, but a method of blending more in the vicinity of the surface is preferably adopted. Examples of a method of blending a large amount in the vicinity of the surface include, for example, a method of blending the sheet of the present invention with two or three layers, and blending an additive into the skin layer (B). In particular, the skin layer (B) is composed of inorganic particles having an average primary particle diameter of 0.1 to 10 μm, preferably 0.5 to 5 μm, and more preferably 0.6 to 3 μm, based on the total weight of the skin layer (B). 0.0005 to 0.5% by weight, preferably 0.01 to 0.3% by weight,
The sheet of the present invention is more preferable because it has sufficient slipperiness without impairing transparency and adhesiveness. In addition,
Examples of preferably used inorganic particles include silica, titanium oxide, calcium carbonate, iron oxide, aluminum oxide, calcium oxide and the like, and mixtures thereof.
Titanium oxide and calcium carbonate are particularly preferably used.

In particular, the skin layer (B) contains glycerin fatty acid ester in an amount of 0.0% based on the total weight of the skin layer (B).
When the content is 1 to 5% by weight, preferably 0.05 to 2% by weight, the sheet of the present invention does not impair printability and adhesiveness.
It is more preferable because it has sufficient slipperiness.
Examples of the glycerin fatty acid ester preferably used include glycerin monobehate, modified glycerin monostearate and the like, and mixtures thereof, and glycerin monostearate is particularly preferably used.

Important characteristics of the sheet of the present invention include thermal characteristics measured by a differential scanning calorimeter (hereinafter referred to as "DSC"), particularly crystallinity. The sheet of the present invention was heated at a heating rate of 20 ° C./min. By DSC, and the crystallization peak temperature was kept at T _c1 , 285 ° C. for 3 minutes, quenched with liquid nitrogen, and then raised again. _Assuming that T _c1 ′ is the temperature rise crystallization peak temperature when the temperature is raised at a rate of 20 ° C./min, the absolute value ΔT _c1 of the difference between T _c1 ′ and T _c1 defined by the following equation (1) is 10 ° C. Or less, preferably 7 ° C. or less, more preferably 5 ° C. or less, and particularly preferably 3 ° C. or less. When the sheet of the present invention has a multilayer structure of two and three layers, ΔT _c1 of the core layer (A) is more preferably in this range.

[0024]

ΔT _c1 = | T _c1 '−T _c1 | (1) The present inventors have conducted intensive studies on the problem of cracking when stacking a predetermined number of sheets and cutting the sheets. It was found that the difference in crystallinity between before and after was very well correlated with the sheet cutability. That is, the cutability of the sheet is improved as the crystallinity of the sheet cooled by a casting roll or the like at the time of forming the sheet is substantially closer to the crystallinity after quenching from the molten state. This is because the cuttability of the sheet is correlated with the microstructure of the polyester in the sheet, and if many microstructures such as crystal nuclei and precursors are generated, the cuttability is reduced due to embrittlement of the sheet, It is estimated that a large number of sheets that occasionally break are generated. The degree of generation of such a fine structure is not only the casting conditions at the time of forming the sheet, but also the extrusion conditions at the time of forming the sheet, the composition of the raw material polyester, the polymerization catalyst, the polymerization aid, the melt viscosity, and the sheet haze described below, Alternatively, it may also depend on the additive to the sheet and the amount thereof. In particular, in the case of a multilayer structure of two types and three layers, the cutability of the sheet largely depends on the above-described crystallinity of the core layer.

According to the study of the present inventors, the degree of generation of the fine structure can be easily determined from the above-mentioned ΔT _c1 , and the smaller the ΔT _c1 , the lower the degree of generation of the fine structure, and the cutability is improved. Normally, a microstructure is formed in the obtained sheet, but after the sheet is melt-quenched, the crystallization is slower after the melt quenching because there is substantially no fine structure (T _{c1). Tc1} becomes smaller than '). The greater the difference (ΔT _c1 ), the lower the cutability, and the ΔT _c1 becomes 1
When the temperature exceeds 0 ° C., the cutting property is remarkably reduced, and it is not possible to stack a predetermined number of sheets and cut the sheet into a desired shape at once, which is not preferable.

When the raw material polyester is substantially amorphous, the obtained sheet is also amorphous,
_{Since c1} and _Tc1 'cannot be observed, they are excluded from the scope of the present invention. However, the lower the degree of generation of the fine structure, the better the cutability. The polyester sheet of the present invention,
Haze measured in the thickness direction is 5% or less, preferably 4%
Or less, more preferably 3% or less, particularly preferably 2%
It is as follows. When the haze is in this range, the sheet of the present invention is more preferable because not only is the sheet excellent in transparency and aesthetic appearance, but also the cutting property of the sheet is improved. The haze is measured with a haze meter.

The polyester sheet of the present invention has a Ge atom content of usually 10 to 100 p.
pm, preferably 20 to 60 ppm, the content of Sb atoms is usually 0 to 100 ppm, preferably 0 to 50 ppm,
The content of Ti atoms is usually 0 to 15 ppm, preferably 0 to 15 ppm.
-10 ppm. When the content of these metal atoms derived from the residue of the polymerization catalyst of the raw material polyester is within this range, the polymerizability of the raw material polyester is excellent, and
The ΔTc1 of the sheet of the present invention tends to be sufficiently small and tends to be excellent in cutability, so that it is more preferable. Further, the Ge atom content, Sb atom content, and Ti atom content of the core layer (A)
More preferably, the atomic content is in the above range. In addition,
The content of Ge, Sb, and Ti atoms is measured by a fluorescent X-ray method.

Next, a method for producing the polyester sheet of the present invention will be described. The polyester sheet of the present invention is a substantially amorphous sheet-like molded body that has been quenched and solidified after melt extrusion. If the obtained sheet is crystallized, it is not preferable because it is inferior in cuttability, impact resistance, transparency and moldability. The method of forming the sheet is not particularly limited.For example, after drying the polyester raw material by a conventional method, the polyester material is supplied to an extruder, extruded at a resin temperature in the range of 250 to 320 ° C., cooled and solidified on a casting drum, and the sheet is cooled. A method of forming is exemplified. By providing the extruder with a vent port, the drying step can be omitted or the drying time can be shortened.

In forming the sheet, the following conditions are desirable as a method for making the sheet of the present invention substantially amorphous and improving cutability, surface properties, thickness uniformity, moldability, impact resistance and the like. That is, the temperature of the casting roll at the time of cooling and solidification is usually 0 to 80C, preferably 10 to 50C. It is also one of the preferable methods to equip one or more touch rolls near the casting roll and use the touch roll as a holding roll at the time of forming a sheet.

The thickness of the polyester sheet of the present invention obtained by the above method is usually 0.1 to 5 mm, preferably 0.15 to 3 mm, more preferably 0.18 to 1 mm.
mm. When the thickness is in this range, the rigidity, impact resistance, and moldability of the sheet of the present invention are good.
The polyester sheet of the present invention may have a single-layer structure or a laminated structure, but preferably has a laminated structure, and more preferably has a laminated structure.
The seed three-layer structure is as described above. In the case of a sheet having a multilayer structure, a known manufacturing method such as melt lamination, dry lamination, or co-extrusion may be employed.
The coextrusion method is preferred from the viewpoint of sheet quality. In particular, in order to form a laminated structure of two types and three layers, a co-extrusion method is used by using a sheeting equipment having a die in which two extruders are connected in parallel, for example, a die with a feed block or a multi-manifold die. It is preferably manufactured.

Next, a method of forming and processing the sheet of the present invention will be described. The sheet of the present invention can be used as a container or a blister by thermoforming similarly to a conventional PET sheet. Examples of the thermoforming method to be used include vacuum molding, compressed air molding, hot plate molding, plug assist molding, reverse draw molding, air slip molding and the like, or a molding method combining these molding methods. In particular, a method suitable for forming and processing the sheet of the present invention is a method of cutting and stacking a large number of sheets to make a single-sheet sheet utilizing its excellent cutting suitability. The sheet obtained by cutting is folded, assembled, and glued, after providing ruled lines and the like, similarly to a sheet made of vinyl chloride and rolled polypropylene sheet, which is generally used as a material for a clear case. It can be processed to obtain a packaging container.

[0032]

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. In addition, the measurement and evaluation methods of various physical properties in Examples,
Each is as follows. [Measurement / Evaluation Methods] The methods for measuring the intrinsic viscosity, Tc1, Tc1 ′, sheet haze, and metal atom content are as described in the text.

(1) Evaluation of cutability 200 sheets to be cut are stacked, and the angle of the blade edge is 2
The evaluation was performed by cutting with an 8 degree cutting machine. The evaluation criteria are as follows. ：: Cracks occurred in the lower 0 of the stack
20: △: The cracks occurred in the lower 21 of the stack
×: cracks occurred randomly during stacking [Raw materials] The raw materials used in this example are shown in Tables 1 and 2 below.

[0034]

[Table 1] (The abbreviations in the table are as follows: TPA: terephthalic acid, IPA: isophthalic acid, DEG: diethylene glycol, CHDM: 1,4-cyclohexanedimethanol)

[0035]

[Table 2]

Examples 1 to 8 and Comparative Examples 1 to 6 The raw materials shown in Tables 1 and 2 were blended at the blending ratio shown in Table 3 below to produce sheets having a thickness of 0.3 mm. Table 4 below shows the measurement results of the intrinsic viscosity, T _c1 , T _c1 ′, ΔT _c1 , haze, and metal atom content of the sheet, and the results of evaluation of the cutting properties. The sheet was prepared by blending each raw material as necessary, then using a 65 mmφ twin screw extruder with a vent port (for a skin layer) and a 120 mm with a vent port.
Feed to φ twin screw extruder (for core layer), resin temperature 290 ℃
Extruded from T-die with feed block at 40 ° C
This was performed by quenching on a casting roll. By controlling the discharge amount of each extruder, the type 3 of which the skin layer thickness is 0.02 mm and the core layer thickness is 0.26 mm (the total thickness of the skin layer is about 13% of the thickness of the entire sheet) Or a multilayer structure of two or three layers. Examples 1 to 8 were all polyester sheets having excellent cutting properties. On the other hand, Comparative Examples 1 to 6 were all polyester sheets inferior in cuttability.

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

According to the present invention, the cutting property is particularly improved while maintaining the conventional transparency, printability and adhesiveness.
A polyester sheet capable of significantly improving the productivity during processing can be provided, and its industrial value is high.

Claims (8)

[Claims] 1. A polyester sheet comprising a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol, having an intrinsic viscosity of 0.1.
A polyester sheet characterized by a temperature rising crystallization peak temperature difference ΔT _{c1 of} 60 dl / g or more, determined by the following formula (1), of 10 ° C. or less, and a haze measured in a thickness direction of 5% or less. ΔT _c1 = | T _c1 '−T _c1 | (1) (where T _c1 is the crystallization peak temperature at the time of temperature rise, and T _c1 ′ is maintained at 285 ° C. for 3 minutes.) Shows the temperature rise crystallization peak temperature when quenched and then heated again.) 2. The method according to claim 1, wherein the content of germanium (Ge) atoms is 1
0 to 100 ppm, antimony (Sb) atom content is 0 to 100 ppm, titanium (Ti) atom content is 0 to 100 ppm
The polyester sheet according to claim 1, wherein the content is 15 ppm. 3. A skin layer (B) on both surfaces of the core layer (A).
Is a polyester sheet having a laminated structure, wherein the core layer (A) and the skin layer (B) are each made of the following polyester, and the total thickness of the skin layer (B) is 1 to 30 of the total thickness of the sheet. % Of the polyester sheet. Core layer (A): a polyester comprising a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol, wherein a diol component other than ethylene glycol in all diol components is 5 mol% or less, Polyester having an intrinsic viscosity of 0.60 dl / g or more Skin layer (B): a polyester comprising a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol, wherein ethylene glycol is contained in all diol components. 3-50 mol% of other diol components
Polyester having an intrinsic viscosity of 0.60 dl / g or more 4. The polyester sheet according to claim 3, wherein cyclohexanedimethanol is used as a diol component other than ethylene glycol constituting the polyester of the skin layer (B). 5. The skin layer (B) comprises inorganic particles having an average primary particle diameter of 0.1 to 10 μm in a range of 0.0005 to 0.5.
The polyester sheet according to claim 3, wherein the content is 5% by weight. 6. The polyester sheet according to claim 3, wherein the skin layer (B) contains 0.01 to 5% by weight of a glycerin fatty acid ester. 7. The core layer (A) contains 10 to 10 Ge atoms.
0 ppm, Sb atom is 0 to 100 ppm, Ti atom is 0 ppm
The polyester sheet according to claim 3, wherein the content of the polyester sheet is from 15 to 15 ppm. 8. A polyester packaging container obtained by punching, folding and assembling the sheet according to claim 1.