Packaging containers

Abstract

To provide a packaging container containing a polyethylene terephthalate resin derived from a biomass resource which is not inferior to physical property aspect of mechanical properties of polyethylene terephthalate derived from a conventional fossil fuel resource.SOLUTION: A packaging container is formed from a resin composition containing a polyethylene terephthalate resin derived from a biomass resource, wherein a half value by integrated intensity calculation of a halo peak in a diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα rays at 25°C is 0.94 to 1.06 of a half value of a halo peak derived from a polyethylene terephthalate resin derived from a fossil fuel measured using CuKα rays at 25°C.SELECTED DRAWING: Figure 2-1

Description

Technical Field

[0001] The present invention relates to a packaging container.

Background Art

[0002] Packaging containers made of resins such as polyethylene terephthalate (PET) are generally known. Resin-made packaging containers are lightweight and excellent in chemical resistance to contents, etc., and thus are used for containing various contents such as beverages, liquid seasonings, detergents, etc.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, in consideration of environmental impact, in recent years, a part of resin products has been replaced with resins derived from biomass resources. However, according to the intensive study by the present inventor, when forming a packaging container using polyethylene terephthalate resin derived from biomass resources, the buckling strength was often low.

[0006] This invention has been made in consideration of the above technical background, and aims to provide a packaging container containing polyethylene terephthalate resin derived from biomass resources that is comparable to conventional polyethylene terephthalate derived from fossil fuel resources in terms of physical properties such as mechanical properties. [Means for solving the problem]

[0007] The packaging container of the present invention is formed from a resin composition containing polyethylene terephthalate resin derived from biomass resources, and the half-value calculated by integral intensity of the halo peak in the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C is 0.94 to 1.06 compared to the half-width of the halo peak derived from fossil fuel-derived polyethylene terephthalate resin measured using CuKα radiation at 25°C.

[0008] The packaging container of the present invention is formed from a resin composition containing polyethylene terephthalate resin derived from biomass resources. The difference between the peak top and the midpoint of the halo peak, calculated by integral intensity calculation of the halo peak in the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C, is 0.24 to 5.08 compared to the difference between the peak top and the midpoint of the halo peak derived from fossil fuel-derived polyethylene terephthalate resin, measured using CuKα radiation at 25°C.

[0009] The packaging container of the present invention is formed from a resin composition containing polyethylene terephthalate resin derived from biomass resources. The half-value of the halo peak in the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C is 11.00 to 12.00°, and the difference between the peak top and the center value of the half-width is 1.00° or less. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a packaging container containing a polyethylene terephthalate resin derived from biomass resources that is comparable to conventional polyethylene terephthalate derived from fossil fuel resources in terms of physical properties such as mechanical properties. [Brief explanation of the drawing]

[0011] [Figure 1-1] Figure 1-1 shows the results of the integrated intensity calculation using the peak-top method for the halo peak of bottle sample 2 (n3 sample) of Comparative Example 1. [Figure 1-2] Figure 1-2 shows the results of the integrated intensity calculation using the half-width method for the halo peak of bottle sample 2 (n3 sample) of Comparative Example 1. [Figure 2-1] Figure 2-1 shows the results of the integrated intensity calculation using the peak-top method for the halo peak of bottle sample 2 (n3 sample) in Example 1. [Figure 2-2] Figure 2-2 shows the results of the integrated intensity calculation using the half-width method for the halo peak of bottle sample 2 (n3 sample) in Example 1. [Figure 3-1] Figure 3-1 shows the results of the integrated intensity calculation using the peak-top method for the halo peak of bottle sample 2 (n3 sample) in Example 2. [Figure 3-2] Figure 3-2 shows the results of the integrated intensity calculation using the half-width method for the halo peak of bottle sample 2 (n3 sample) in Example 2. [Figure 4] Figure 4 is a schematic front view showing a partially cross-sectional end face of one embodiment of a lidded container according to one embodiment of the present invention. [Modes for carrying out the invention]

[0012] The packaging container of this embodiment is a packaging container formed from a resin composition containing polyethylene terephthalate resin derived from biomass resources, and the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C satisfies at least one of the following (1) to (3). (1) The half-value obtained by calculating the integrated intensity of the halo peak is 0.94 to 1.06 with respect to the half-width of the halo peak derived from a fossil fuel-derived polyethylene terephthalate resin measured using CuKα radiation at 25°C. (2) The difference between the peak top and the center value of the half-width obtained by calculating the integrated intensity of the halo peak is 0.24 to 5.08 with respect to the difference between the peak top and the center value of the half-width of the halo peak derived from a fossil fuel-derived polyethylene terephthalate resin measured using CuKα radiation at 25°C. (3) The half-value obtained by calculating the integrated intensity of the halo peak is from 11.00 to 12.00°, and the difference between the peak top and the center value of the half-width is 1.00° or less. Such a packaging container has excellent buckling strength.

[0013] The half-value obtained by calculating the integrated intensity of the halo peak may be 0.96 to 1.04 with respect to the half-width of the halo peak derived from a fossil fuel-derived polyethylene terephthalate resin.

[0014] The difference between the peak top and the center value of the half-width obtained by calculating the integrated intensity of the halo peak may be 0.33 to 4.31 with respect to the difference between the peak top and the center value of the half-width of the halo peak derived from a fossil fuel-derived polyethylene terephthalate resin measured using CuKα radiation at 25°C.

[0015] The half-value by the integral intensity calculation of the halo peak may be 11.00° or more, may be 11.20° or more, may be 11.30° or more, may be 11.36° or more, may be 11.40° or more, may be 11.45° or more, may be 11.50° or more. The half-value by the integral intensity calculation of the halo peak may be 12.00° or less, may be 11.90° or less, may be 11.80° or less, may be 11.70° or less, may be 11.51° or less. The half-value by the integral intensity calculation of the halo peak may be 11.20 to 12.00°, may be 11.30 to 11.90°, may be 11.40 to 11.80°, may be 11.45 to 11.70°, may be 11.50 to 11.60°. The half-value by the integral intensity calculation of the halo peak may be 11.36 to 11.51°.

[0016] The difference between the peak top and the center value of the half-width by the integral intensity calculation of the halo peak may be 1.00° or less, may be 0.90° or less, may be 0.80° or less, may be 0.76° or less, may be 0.75° or less, may be 0.65° or less, may be 0.60° or less, may be 0.50° or less, may be 0.45° or less, may be 0.40° or less. The difference between the peak top and the center value of the half-width by the integral intensity calculation of the halo peak may be 0.05° or more, may be 0.10° or more, may be 0.20° or more. The difference between the peak top and the center value of the half-width by the integral intensity calculation of the halo peak may be 1.00 to 0.05°, may be 0.90 to 0.05°, may be 0.80 to 0.05°, may be 0.75 to 0.10°, may be 0.65 to 0.10°, may be 0.60 to 0.10°, may be 0.50 to 0.20°, may be 0.45 to 0.20°.

[0017] The bio-content (biomass content) of polyethylene terephthalate may be 20% or more, or 25% or more, and almost all polyethylene glycol units contained in polyethylene terephthalate may be derived from biomass resources. The bio-content is the mass ratio of structural units derived from biomass resources to the total amount of polyethylene terephthalate resin (polymer). The structural units derived from biomass resources may be ethylene glycol units (-O-CH2CH2-O-).

[0018] Commercially available polyethylene terephthalate resin derived from biomass resources may be used. Examples of commercially available products include LOTTE CHAMICAL PET BIO (manufactured by LOTTE CHEMICAL) and RAMAPET N1B (manufactured by Indorama).

[0019] It is known that in PET (polyethylene terephthalate) bottles, the orientation in the direction of internal stretching decreases and amorphousness increases in the order of the mouth area, shoulder area, and body area during the cooling process after molding (Non-Patent Literature 1).

[0020] Furthermore, X-ray diffraction (XRD) allows for the investigation of the state and properties of a substance by measuring and analyzing the diffraction that occurs when X-rays are scattered by electrons around atoms after being irradiated onto a sample.

[0021] When measuring the orientation of the inside of a bottle that depends on the direction of stretching using XRD, the in-plane method is useful. However, when measuring the crystallinity and degree of crystallinity of a bottle, the out-of-plane method, which does not depend on the orientation of the inside of the bottle in the direction of stretching, is considered useful.

[0022] In other words, while the in-plane method, which measures lattice planes perpendicular to the sample surface, is useful for evaluating orientation dependent on the stretching direction due to molding, XRD measurement using the out-of-plane method allows for measurement in the depth direction (thickness direction) on lattice planes parallel to the sample surface. Therefore, it is possible to measure crystallinity in the depth direction that takes into account crystallinity due to orientation, regardless of the stretching direction.

[0023] XRD testing may be performed on the resin composition constituting the packaging container after the packaging container has been formed. The mouth and shoulder areas of the packaging container are relatively affected by orientation, and the amorphous state due to the cooling process after molding may not be sufficient, so it may be difficult to obtain the amorphous peak (halo peak) that the inventors focused on.

[0024] Therefore, in XRD testing, it is desirable to use the body of the packaging container, where amorphous peaks (halo peaks) are easily obtained, as the measurement site.

[0025] In XRD analysis, it is generally desirable for the sample surface to be flat. Although the body of the packaging container is curved, by flattening it to some extent by hand, even if there are some irregularities, the XRD analysis optical system can be set to the parallel beam method (the parallel beam method is an optical system that compresses, parallelizes, and monochromatizes the divergent beam generated from the X-ray source using a parabolic multilayer mirror). By extracting parallel X-ray components, the halo peak can be detected without being affected by the irregularities of the sample surface. In recent XRD analyzers, this parabolic multilayer mirror (a parabolic multilayer mirror is an X-ray optical element set so that when X-rays incident at different angles of incidence are reflected by a multilayer film, all reflected X-rays are emitted in parallel) is usually included, so even if the peak intensity and angular resolution are lower due to the extraction of parallel X-rays, improvements have been made.

[0026] While the wall thickness of the packaging container is approximately 0.5 mm, the detection depth (vertical: θ=90°, 99% diffraction utilization rate) of X-rays (CuKα: generated energy = 8 keV) from PET (polyethylene terephthalate) is approximately 2.47 mm (Non-patent documents 2 and 3). At 2θ=35°, which is almost the end of the halo peak derived from PET, the depth is 0.74 mm (99% diffraction utilization rate). However, since the clay substrate used to fix the sample to the measurement sample stage is made of a material that does not produce diffraction peaks and is exclusive to the equipment manufacturer, the substrate does not affect the results, and crystal structure information in the thickness direction of the test piece can be obtained.

[0027] Furthermore, by using the 2θ-θ method for XRD analysis scanning, there is no change in the size of the measurement area in the depth direction of the sample with respect to the diffraction angle 2θ (where 2θ is the angle between the incident X-ray direction and the diffracted X-ray direction), and diffraction lines are obtained according to Bragg's diffraction conditions (2d × sinθ = λ: d is the lattice plane spacing, which is the spacing between the lattice planes of the sample diffracted by X-rays). Therefore, even in amorphous materials, in the case of solids such as PET, halo peaks (halo peaks are areas where the atomic structure arrangement is randomly arranged) are obtained. In the case of Rufus (amorphous), the X-ray diffraction pattern detected by XRD measurement is a very halo (continuous). The profile is broad and symmetrical around the peak top (the peak top is the vertex of the X-ray diffraction pattern) based on its atomic arrangement, and the full width at half maximum (full width at half maximum is the width of the profile at half the peak intensity of the X-ray diffraction profile (diffraction intensity curve)) of the halo peak is influenced by the original crystal structure of the sample (such as the periodicity of the lattice).

[0028] However, if there is disorder (non-uniformity) in the chemical structure (arrangement and configuration of atoms), the lattice constant changes relative to the parent structure, causing the peak top to shift towards the higher angle and resulting in a distorted shape.

[0029] While it is generally believed that high chemical structural uniformity leads to stable mechanical properties, slight disturbances in the arrangement and configuration of atoms occur during the chemical synthesis process and heating / cooling during molding.

[0030] In other words, it is desirable that the arrangement and configuration of atoms in the packaging container of this embodiment have a level of uniformity in mechanical properties that is comparable to that of packaging containers formed from polyethylene terephthalate resin derived from fossil fuels, which substantially do not contain polyethylene terephthalate resin derived from biomass resources.

[0031] Therefore, as a result of the inventors' investigation, it was found that there is a correlation with buckling strength by defining the width and shape distortion of the halo peak by examining the half-width of the halo peak detected by XRD analysis and the difference between the peak top position and the center value of the half-width for the body portion of the packaging container.

[0032] Figure 4 is a schematic front view showing a partial cross-sectional end face of one embodiment of the capped container of the present invention. In Figure 4, only the inner cap and outer cap are shown as cross-sectional end faces.

[0033] As shown in Figure 4, the lidded container 100 of this disclosure comprises a bottle (packaging container) 10 for containing contents (not shown), an inner cap 20 attached to the mouth 11 of the bottle 10 and having an opening 20a, and an outer cap 30 detachably attached to the inner cap 20 and closing the opening 20a of the inner cap 20. Examples of contents to be contained in the container include liquid seasonings such as dressings and beverages. The bottle 10 comprises, for example, a cylindrical body 12, a cylindrical mouth 11 provided at one end of the body 12, and a bottom 13 provided at the other end of the body 12. One end of the body 12 and the opening 11 are connected by a shoulder portion 14. The opening 11 forms a flow path for receiving the contents into the body 12 and for dispensing the contents from the body 12. A receiving flange 15 for receiving the inner cap 20 may also be provided on the outer surface of the opening 11. The inner cap 20 is attached to the mouth 11 of the bottle 10. The inner cap 20 may be attached to the mouth 11 of the bottle 10 by a press-fitting method, for example. The inner cap 20 comprises, for example, a cylindrical base 21 fixed to the mouth 11 of the bottle 10, a cylindrical dispensing portion 22 having an opening 20a for dispensing the contents, and an intermediate portion 23 provided between the base 21 and the dispensing portion 22 for fixing the outer cap 30. The outer circumferential surface of the intermediate portion 23 may have a threaded structure (not shown) that engages with, for example, the outer cap 30. The threaded structure may be formed by creating a spiral projection along the extension direction of the cylindrical intermediate portion. The outer cap 30 may be formed from a resin composition containing a resin including polypropylene resin and polyethylene resin. The resin composition may contain a resin derived from biomass resources, and may also contain polyethylene resin derived from biomass resources. The inner cap may be formed from an inner cap forming resin composition. The inner cap forming resin composition preferably contains, for example, a polyolefin resin, and more preferably, a polyethylene resin. The polyethylene resin may be a polyethylene resin derived from biomass resources. The outer cap 30 is detachably attached to the inner cap 20 and closes the opening 20a of the inner cap 20. The outer cap 30 has a cylindrical side wall portion 31, a dome-shaped ceiling portion 32 provided at one end of the side wall portion 31, a cylindrical projection 33 extending from the inner wall surface of the ceiling portion 32, and a cylindrical sealing portion 34 extending from the inner wall surface of the ceiling portion 32 inside the projection 33. Here, the sealing portion 34 is fitted into the opening 20a of the dispensing portion 22 of the inner cap 20. As a result, the sealing portion 34 extending from the inner wall surface of the ceiling portion 32 is housed in the opening 20a of the dispensing portion 22, thereby preventing the contents from leaking out of the dispensing portion 22.

[0034] X-ray diffraction testing may be performed on specimens cut from the packaging container. There are no particular restrictions on the size of the specimens as long as they are measurable, but for example, they can be 20 mm x 20 mm. The half-value, peak top position, and center value of the half-width in (1) to (3) above may be the average value obtained from X-ray diffraction testing performed on multiple specimens cut from the same packaging container, and the number of n may be, for example, 3.

[0035] In this embodiment, the mechanical strength of the packaging container can be estimated by analyzing the X-ray diffraction chart without directly measuring its mechanical strength. Therefore, by introducing a step of X-ray diffraction analysis into the manufacturing process of the packaging container, defective products can be easily removed. [Examples]

[0036] Next, the present invention will be described with reference to specific examples, but the present invention is not limited to these.

[0037] <Preparation of resin compositions for bottles> To prepare the bottle resin composition, 5 parts by mass of the following green coloring masterbatch (MB) were added to 100 parts by mass of the following PET, and the mixture was extruded using an extruder. This mixture was then dried at 160°C for 4 hours using a dehumidifying dryer (Kawata, model "AKPD-80N") to prepare the bottle resin composition. The temperature inside the extruder was 260°C. Table 1 shows the materials and stretch blow molding machines used in Examples 1 and 2 (both manufactured by Nissei ASB Machinery Co., Ltd.), and Table 2 shows the materials used in Comparative Example 1. In Tables 1 and 2, the unit of the mixing ratio is parts by mass. [Table 1] [Table 2]

[0038] The resin composition for the bottle obtained as described above was placed into a stretch blow molding machine (manufactured by Nissei ASB Machinery Co., Ltd., model name "PF8-4B"), and injection molding was performed using a bottle mold at 270°C for 30 seconds to obtain the bottle shown in Figure 4. The bottle was molded to have a cylindrical body (inner diameter 63 mm, outer diameter 64 mm, length 134 mm), a cylindrical mouth (inner diameter 28 mm, outer diameter 30 mm, length 18 mm) provided at one end of the body, a bottom provided at the other end of the body, and a shoulder portion connecting one end of the body to the mouth. This is how the bottle was made.

[0039] The following describes the buckling strength test method according to the example, the X-ray diffraction apparatus and its measurement conditions, and the integrated intensity calculation conditions (using the software attached to the apparatus) for determining the full width at half maximum (FWHM), peak top position, and center position of the halo peak obtained from the measurement.

[0040] The buckling strength test method for the example is shown below. <Measurement of buckling strength> A commercially available compression testing machine (manufactured by Shimadzu Corporation, product name: Autograph AGS-X 5kN) was used to measure the buckling strength. The bottle was placed upright with the opening facing upwards, and pressed down from above with a fixing plate at a descent speed of 10 mm / min and a compressive strain of 3 mm. The maximum value of the measured force (N) was defined as the buckling strength.

[0041] Furthermore, the ultrasonic cutter used to cut out the body portion of each PET bottle according to the example is shown for each PET bottle after the buckling strength test. Ultrasonic cutter: SUW-30CT (manufactured by Suzuki Motor Corporation) • Maximum output: 35W (continuously variable) • Oscillation method: Self-excited oscillation, automatic frequency tracking Using the included handpiece, the body sections of each PET bottle were cut out according to the specifications described above.

[0042] Next, for each sample cut out as described above, the X-ray diffraction apparatus, its measurement conditions, and the integrated intensity calculation conditions (using the software attached to the apparatus) are shown. X-ray diffraction analyzer (XRD system): RINT ULTIMA III (manufactured by Rigaku Corporation) <Measurement conditions> Out-of-plane XRD measurement ·X-ray source: CuKα, Voltage and current values: 40kV, 40mA • Optical system: Parallel beam method ·Scanning axis: 2θ-θ method Scanning speed: 1° / min, Sampling speed: 0.010° / min • Measurement range: 5° < 2θ < 45° • Sample stage control mode: Rotation <Integrated strength calculation conditions> • Peak cutting range: 6°~38° To prioritize the halo peak profile, error correction such as LPA correction was not performed. Instead, smoothing and background processing were applied to calculate the full width at half maximum (FWHM), peak top position, and FWHM center position.

[0043] In addition to the calculation conditions described above, the full width at half maximum (FMAX) and the peak top position and the center position of the FMAX were determined using the following two peak calculation methods. However, the FMAX value was the same regardless of which peak calculation method was used. The peak top position of the halo peak was determined using the peak top method. The center position of the half-width of the halo peak was determined using the half-width method for peak calculation.

[0044] Next, comparative examples and examples of fossil fuel-derived PET (general PET) bottles that substantially do not contain polyethylene terephthalate resin derived from biomass resources and PET (bio-PET) bottles that contain biomass-derived PET are described.

[0045] <Comparative Example 1> After the buckling strength test, the body of a bottle made of PET that substantially does not contain polyethylene terephthalate resin derived from biomass resources was cut out using the ultrasonic cutter described above. Three 20mm x 20mm pieces of measurement sample were then cut from the cut body using scissors. In this way, three strip-shaped test pieces (each designated as n1 to n3 samples) were cut from three PET bottles (each designated as bottle sample 1 to 3), resulting in a total of nine measurement samples. X-ray diffraction measurements were performed on these measurement samples, and the full width at half maximum (FWHM) and the position of the peak top and the center position of the FWHM were determined by integral intensity calculation analysis of the obtained halo peaks. The difference between the peak top position and the center position of the FWHM was then calculated.

[0046] Figure 1-1 shows the integrated intensity calculation results for the halo peak of bottle sample 2 (n3 sample) of Comparative Example 1 using the peak-top method. Figure 1-2 shows the integrated intensity calculation results for the halo peak of bottle sample 2 (n3 sample) of Comparative Example 1 using the half-width method. In Figures 1-1 and 1-2, the vertical lines in the graphs indicate the peak positions.

[0047] From Figures 1-1 and 1-2, the analysis results for bottle sample 2 (n3 sample) of Comparative Example 1 are as follows. • Width at half maximum: 11.37° • Peak top position: 22.57° (Peak calculation method: Peak top method) • Center position of the half-width: 21.77° (Peak calculation method: half-width method) • Difference between the peak top position and the center position of the full width at half maximum: 22.57 - 21.77 = 0.80°

[0048] <Example 1> After the buckling strength test, the full width at half maximum (FWHM) and the position of the peak top and the center position of the FWHM were determined for a liquid bottle formed from biomass-derived PET (30% bio-grade) (manufactured by Lotte Chemical Co., Ltd.) using the same procedure as in Comparative Example 1, and the difference between the peak top position and the center position of the FWHM was calculated.

[0049] Figure 2-1 shows the integrated intensity calculation results for the halo peak of bottle sample 2 (n3 sample) of Example 1 using the peak-top method. Figure 2-2 shows the integrated intensity calculation results for the halo peak of bottle sample 2 (n3 sample) of Example 1 using the half-width method. In Figures 2-1 and 2-2, the vertical lines in the graphs indicate the peak positions.

[0050] From Figures 2-1 and 2-2, the analysis results for bottle sample 2 (n3 sample) of Example 1 are as follows. • Width at half maximum: 11.44° • Peak top position: 22.83° (Peak calculation method: Peak top method) • Center position of the half-width: 21.99° (Peak calculation method: half-width method) • Difference between the peak top position and the center position of the full width at half maximum: 22.83 - 21.99 = 0.84°

[0051] <Example 2> After the buckling strength test, the full width at half maximum (FWHM) and the position of the peak top and the center position of the FWHM were determined for a liquid bottle made from biomass-derived PET (30% bio-grade) (manufactured by Indorama Co., Ltd.) using the same procedure as in Comparative Example 1, and the difference between the peak top position and the center position of the FWHM was calculated.

[0052] Figure 3-1 shows the integrated intensity calculation results for the halo peak of bottle sample 2 (n3 sample) of Example 2 using the peak-top method. Figure 3-2 shows the integrated intensity calculation results for the halo peak of bottle sample 2 (n3 sample) of Example 2 using the half-width method. In Figures 3-1 and 3-2, the vertical lines in the graphs indicate the peak positions.

[0053] From Figures 3-1 and 3-2, the analysis results for bottle sample 2 (n3 sample) of Example 2 were as follows. • Width at half maximum: 11.12° • Peak top position: 22.71° (Peak calculation method: Peak top method) • Center position of the half-width: 21.91° (Peak calculation method: half-width method) • Difference between the peak top position and the center position of the full width at half maximum: 22.71 - 21.91 = 0.80°

[0054] Next, Table 3 shows the XRD analysis results for each bottle sample (Comparative Example 1 and Examples 1 and 2), including the full width at half maximum (FWHM), the peak top position and the center position of the FWHM, and the difference between the peak top position and the center position of the FWHM (=peak difference) (listed in ascending order of peak difference), as well as the buckling strength test results.

[0055] [Table 3]

[0056] From the results in Table 3 above, regarding the peak difference, bottle sample 1 of Comparative Example 1 showed a difference of 0.24(°) to 0.26(°), but there was no such small peak difference in Examples 1 and 2. This suggests that because Examples 1 and 2 are derived from biomass resources, there may be some slight, partial disorder (non-uniformity) in their chemical structure (arrangement and configuration of atoms) compared to samples derived from fossil fuels (i.e., samples that substantially do not contain polyethylene terephthalate resin derived from biomass resources).

[0057] However, regarding buckling strength, Comparative Example 1 was 277 N·m to 299 N·m (average: 287 N·m), Example 1 was 277 N·m to 296 N·m (average: 286 N·m), and Example 2 was 283 N·m to 296 N·m (average: 289 N·m). The buckling strengths of Examples 1 and 2 were comparable to those of Comparative Example 1. Furthermore, in both Comparative Example 1 and Examples 1 and 2, a tendency was observed for buckling strength to decrease as the peak difference increased. Moreover, when examining the relationship between peak difference and full width at half maximum, a tendency was generally observed for full width at half maximum to decrease as the peak difference increased.

[0058] Therefore, we calculated the ratio of the minimum value (10.91) of Examples 1 and 2 to the maximum value (11.60) of Comparative Example 1 regarding the full width at half maximum. 10.91 / 11.60 = 0.94.

[0059] Furthermore, when we calculated the ratio of the maximum value (11.59) of Examples 1 and 2 to the minimum value (10.89) of Comparative Example 1 regarding the full width at half maximum, 11.59 / 10.89 = 1.06.

[0060] Furthermore, when we calculated the ratio of the minimum values ​​(11.04) of Examples 1 and 2 to the maximum value (11.56) of Comparative Example 1 for the average half-width of each sample, 11.04 / 11.56 = 0.96.

[0061] Furthermore, when we calculated the ratio of the maximum value (11.51) of Examples 1 and 2 to the minimum value (11.10) of Comparative Example 1 for the average half-width of each sample, 11.51 / 11.10 = 1.04.

[0062] Therefore, the half-value calculated by the integrated intensity of the halo peak in X-ray diffraction (XRD) was 0.94 to 1.06, more preferably 0.96 to 1.04, for packaging containers containing polyethylene terephthalate resin derived from biomass resources compared to packaging containers substantially free of such resin.

[0063] Next, from the results in Table 3, we calculated the ratio of the minimum value (0.36) of Examples 1 and 2 to the maximum value (1.36) of Comparative Example 1 regarding the difference between the peak top position and the center position of the full width at half maximum. 0.36 / 1.36 = 0.24.

[0064] Furthermore, regarding the difference between the peak top position and the center position of the full width at half maximum, we calculated the ratio of the maximum value (1.22) of Examples 1 and 2 to the minimum value (0.24) of Comparative Example 1. 1.22 / 0.24 = 5.08.

[0065] Furthermore, regarding the average value of the difference between the peak top position and the center position of the full width at half maximum for each sample, the ratio of the minimum value (0.40) for Examples 1 and 2 to the maximum value (1.20) for Comparative Example 1 was calculated, 0.40 / 1.20 = 0.33.

[0066] Furthermore, regarding the average value of the difference between the peak top position and the center position of the full width at half maximum for each sample, the ratio of the maximum value (1.12) for Examples 1 and 2 to the minimum value (0.26) for Comparative Example 1 was calculated, 1.12 / 0.26 = 4.31.

[0067] Therefore, the difference between the peak top and the center value of the full width at half maximum, calculated by the integrated intensity calculation of the halo peak in the X-ray diffraction (XRD) method according to the present invention, was 0.24 to 5.08, and more preferably 0.33 to 4.31, for packaging containers containing polyethylene terephthalate resin derived from biomass resources, compared to packaging containers substantially free of polyethylene terephthalate resin derived from biomass resources.

[0068] Furthermore, comparing the results of Examples 1 and 2 using a standard that exceeds the average buckling strength of 287 N·m of Comparative Example 1, the average full width at half maximum (FWHM) of bottle sample 1 with an average buckling strength of 296 N·m in Example 1 was 11.46°, and the average peak difference was 0.40°. The average full width at half maximum (FWHM) of bottle sample 1 with an average buckling strength of 296 N·m in Example 2 was 11.50°, and the average peak difference was 0.61°. Thus, the present invention provides a packaging container containing polyethylene terephthalate resin derived from biomass resources, where the FWHM calculated by the integral intensity calculation of the halo peak in X-ray diffraction (XRD) is 11.50° or higher, and the difference between the peak top and the center value of the FWHM is 0.40° or lower. [Explanation of Symbols]

[0069] 10...Bottle, 11...Mouth, 20...Inner cap, 20a...Opening, 30...Outer cap, 100...Container with lid.

Claims

1. A packaging container formed from a resin composition containing polyethylene terephthalate resin derived from biomass resources, A packaging container wherein the half-value of the halo peak in the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C is 0.94 to 1.06 relative to the half-value width of the halo peak derived from fossil fuel-derived polyethylene terephthalate resin, measured using CuKα radiation at 25°C.

2. The packaging container according to claim 1, wherein the half-value of the halo peak calculated by integral intensity calculation in the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C is 0.96 to 1.04 with respect to the half-width of the halo peak derived from fossil fuel-derived polyethylene terephthalate resin measured using CuKα radiation at 25°C.

3. A packaging container formed from a resin composition containing polyethylene terephthalate resin derived from biomass resources, A packaging container wherein the difference between the peak top and the midpoint of the halo peak, calculated by integral intensity calculation of the halo peak in the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C, is 0.24 to 5.08 compared to the difference between the peak top and the midpoint of the halo peak of a fossil fuel-derived polyethylene terephthalate resin measured using CuKα radiation at 25°C.

4. The packaging container according to claim 3, wherein the difference between the peak top and the center value of the full width at half maximum, calculated by integral intensity calculation of the halo peak in the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C, is 0.33 to 4.31 compared to the difference between the peak top and the center value of the full width at half maximum of a halo peak derived from fossil fuel-derived polyethylene terephthalate resin, measured using CuKα radiation at 25°C.

5. The packaging container according to any one of claims 1 to 4, wherein the measured half-value of the resin composition is 11.50° or higher, and the difference between the peak top and the midpoint of the half-value is 0.40° or lower.

6. A packaging container formed from a resin composition containing polyethylene terephthalate resin derived from biomass resources, A packaging container wherein the half-value of the halo peak in the diffraction chart obtained by performing an X-ray diffraction test on the resin composition using CuKα radiation at 25°C is 11.00 to 12.00°, and the difference between the peak top and the center value of the half-value is 1.00° or less.

7. The packaging container according to claim 6, wherein the half-value is 11.36 to 11.51°, and the difference between the peak top and the midpoint of the half-value is 0.76° or less.

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