JP7732263B2 - Storage container and storage body - Google Patents

Description

The present invention relates to a storage container and a storage body.

Conventionally, containers such as PET (Poly Ethylene Terephthalate) bottles have been known to have labels affixed to them that display images such as the product's name, ingredients, expiration date, barcode, QR code (registered trademark), recycle mark, or logo. There have also been attempts to enhance a product's individuality and competitiveness by displaying designs, pictures, or other images that appeal to consumers on the label.

On the other hand, marine pollution caused by plastic waste has recently come under scrutiny, and with global efforts to eliminate this pollution gaining momentum, there is growing demand for closed-loop recycling of storage containers. Here, closed-loop recycling of storage containers refers to recycling companies turning used, separated and collected storage containers into flakes, which are the raw material for new storage containers, and then manufacturing them again.

To smoothly advance this type of closed-loop recycling, it is preferable to thoroughly separate and collect materials by container or label, etc. However, the task of removing labels from containers for separate collection is time-consuming, and is one of the constraints to thorough separate collection.

To solve the above problems, for example, a printing method for resin moldings has been proposed, which involves impregnating a thermoplastic resin molding with 0.1 to 20.0 wt % carbon dioxide and/or 0.03 to 1.0 wt % nitrogen, maintaining the residual carbon dioxide and/or nitrogen concentration on the surface of the molding, as measured by infrared total reflection spectroscopy or Raman spectroscopy, at 20 wt % or more relative to the gas concentration on the surface of the molding immediately after impregnation with carbon dioxide and/or nitrogen, and reducing the surface temperature of the molding to 21.5°C or less, followed by irradiating with a laser at an output of 0.3 to 6 W (see, for example, Patent Document 1). In Patent Document 1, a foaming print is applied to the surface and/or interior of a thermoplastic resin molding impregnated with carbon dioxide and/or nitrogen by laser irradiation.

The present invention aims to provide a storage container that has a higher contrast image and can be recycled smoothly.

The storage container of the present invention as a means for solving the above problem comprises a container body and a visible area in the container body, wherein the image forming area has a lower visible light transmittance than the container body, the visible area has a higher visible light transmittance than the image forming area, an image is formed in the container body by the visible area, the visible area is formed by a collection of a first pattern , the image forming area includes a plurality of bubbles, and the area ratio of the total bubbles in the visible area when observed from the surface of the container body is smaller than the area ratio of the total bubbles in the image forming area .

This invention makes it possible to provide a storage container that has a higher contrast image and facilitates circular recycling.

FIG. 1 is a schematic view showing an example of a storage container according to the first embodiment. FIG. 2 is a schematic diagram showing an example of a conventional storage container. FIG. 3 is a schematic view showing another example of the storage container according to the first embodiment. FIG. 4 is a schematic view showing an example of a container according to the second embodiment, in which the image forming region has a structure including a crystalline phase. FIG. 5 is a graph showing the relationship between the peak intensity of X-ray diffraction and the degree of crystallinity. FIG. 6 is a diagram showing spherulites observed in the laser irradiated and non-laser irradiated areas in the image formation region. FIG. 7 is another view showing the spherulites observed in the laser irradiated and non-laser irradiated areas in the image formation region. FIG. 8 is a schematic diagram showing an example of a container according to the third embodiment, in which the image forming area has a structure containing a plurality of bubbles. FIG. 9 is a schematic view showing an example of a container according to the fourth embodiment, in which the image forming region has a structure including a fine concave-convex structure. FIG. 10 is a schematic diagram showing an example of a storage container according to the fifth embodiment in which a sheet-like member having an image forming area is attached to the periphery of a container body. FIG. 11 is a schematic view showing an example of a container according to the sixth embodiment containing an item. FIG. 12 is a schematic diagram illustrating an example of a container before an image is written according to the seventh embodiment.

(Storage container)
In a first form, the storage container of the present invention comprises a container body and a visible area on the container body, the visible area having a higher visible light transmittance than the container body, an image formed on the container body by the visible area, and the visible area being formed by an assembly of first patterns.
In the first embodiment of the storage container, if the visible area has a higher visible light transmittance than the container body, an image can be formed on the container body by the visible area without providing an image formation area.

In a second form, the storage container of the present invention comprises a container body and an image forming area and a visible area on the container body, wherein the image forming area has a lower visible light transmittance than the container body, the visible area has a higher visible light transmittance than the image forming area, an image is formed on the container body by the visible area, and the visible area is formed by a collection of first patterns.
In the second embodiment of the storage container, the image forming area may be provided on at least a part of the container body of the storage container, and the entire container body may be used as the image forming area.

Conventional technology requires laser marking within the time period during which the residual concentration of carbon dioxide and/or nitrogen has decreased (for example, within 0.5 to 20 hours), which means that long-term storage is not possible. Furthermore, conventional technology requires high-level on/off control of the laser pulse for each pixel in order to create a highly accurate image on containers such as PET bottles by laser marking them, which increases the cost of the laser equipment used.

In the present invention, a transparent image (visible area) is formed on the container body, which has a lower visible light transmittance than the image formation area (solid white area) or the visible area, so that a high-resolution image can be formed at low cost.
Furthermore, according to the present invention, a cost reduction can be realized by forming an image (visible region) on the container body or image formation region (solid white region) that has a lower visible light transmittance than the visible region using an inexpensive laser for heat processing. Furthermore, a two-step approach is used to form the image formation region (solid white region) using a cheap laser that can be handled by simply switching the repetition frequency without a pulse-on-demand function, and to form the transparent image (visible region) using a separate laser that can control the pulse on/off for each pixel, thereby enabling the formation of a high-contrast image at lower cost.

<Container body>
The container body is not particularly limited in terms of material, shape, size, structure, color, etc., and can be appropriately selected depending on the purpose.
The material of the container body is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include resin, glass, etc. Among these, transparent resin or transparent glass is more preferable, and transparent resin is particularly preferable.
Examples of resins that can be used for the container body include polyvinyl alcohol (PVA), polybutylene adipate/terephthalate (PBAT), polyethylene terephthalate succinate, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polyurethane, epoxy, biopolybutylene succinate (PBS), polylactic acid blend (PBAT), starch-blend polyester resin, polybutylene terephthalate succinate, polylactic acid (PLA), polyhydroxybutyrate/hydroxyhexanoate (PHBH), polyhydroxyalkanoic acid (PHA), bioPET30, biopolyamide (PA)610, 410, 510, bioPA1012, 10T, bioPA11T, MXD10, biopolycarbonate, biopolyurethane, bioPE, bioPET100, bioPA11, and bioPA1010. These may be used alone or in combination of two or more. Among these, biodegradable resins such as polyvinyl alcohol, polybutylene adipate/terephthalate, and polyethylene terephthalate succinate are preferred from the viewpoint of environmental load.

The shape of the container body is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a bottle shape, a cylindrical shape, a square prism shape, a box shape, a cone shape, etc. Among these, a bottle shape is preferred.
The bottle-shaped container body has a mouth, a shoulder connected to the mouth, a body connected to the shoulder, and a bottom connected to the body.
The size of the container body is not particularly limited and can be appropriately selected depending on the use of the container.
The structure of the container body is not particularly limited and can be appropriately selected depending on the purpose. For example, it may have a single-layer structure or a multi-layer structure.
The color of the container body may be, for example, colorless transparent, colored transparent, or colored opaque.

<Visible area>
In the storage container of the first embodiment, the visible light transmittance of the visible area is higher than the visible light transmittance of the container body.
In the second embodiment of the storage container, the visible light transmittance of the visible area is higher than that of the image forming area, and the visible light transmittance of the image forming area is lower than that of the container body.

In this invention, "high visible light transmittance" means high average transmittance in the visible light wavelength range, and it does not matter if the transmittance is inverted in some wavelength ranges. "Visible light" means light with a wavelength of 380 nm to 780 nm.

The visible area allows an image to be visibly formed on the container body.
Images include, for example, letters, symbols, figures, images, codes, etc., and specifically refer to information such as the name, ingredients, identification number, manufacturer name, manufacturing date and time, expiration date, barcode, QR code (registered trademark), recycling mark, or logo mark.
The wavelength of the laser for writing the image is preferably from visible light to near infrared light (wavelength: 780 nm to 2,500 nm).
The visible area is formed by an assembly of the first pattern, where assembly means a collection of multiple elements.
The first pattern assembly preferably has a structure including recesses formed by melting the container body, or recesses and protrusions continuous with the recesses.

It is preferable that the crystallinity of the visible region is smaller than the crystallinity of the region other than the visible region of the container body, since this allows for the formation of an image with higher contrast.
The degree of crystallinity can be determined by X-ray diffraction measurement, and it can be determined that the stronger the crystal peak intensity, the higher the degree of crystallinity.

<Image forming area>
The image forming area is an area having a visible light transmittance lower than that of the container body and lower than that of the visible area.
The terms "high visible light transmittance" and "visible light" have the same meaning as the above-mentioned visible region.
The image forming area is preferably formed by an assembly of the second pattern, where assembly means a collection of multiple elements.
The assembly of the second pattern preferably has a structure including recesses formed by melting the container body, or recesses and protrusions continuous with the recesses.

The aggregate of second patterns that form the image forming area is made up of a fine uneven structure, and it is preferable that the surface roughness of the visible area when observed from the surface of the container body is smaller than the surface roughness of the image forming area, as this allows for the formation of an image with higher contrast.
The surface roughness can be measured based on the arithmetic mean roughness Ra of the JIS B0601 standard, for example.
Methods for forming a fine uneven structure include, for example, chemical etching and mechanical etching. Among these, mechanical etching is preferred because it generates less environmental impact, such as waste liquid. Examples of mechanical etching include wet blasting and sand blasting. In addition, a storage container having a fine uneven structure can be obtained by forming a fine uneven structure on the surface of a molding die and transferring it using a die having the fine uneven structure.

Furthermore, it is preferable that the image forming area contains multiple bubbles and that the area ratio of the bubbles in the visible area when observed from the surface of the container body is smaller than the area ratio of the bubbles in the image forming area, as this allows for the formation of an image with higher contrast.
The area ratio of the total bubbles can be measured, for example, by measuring the total area of bubbles observable in a predetermined field of view with an optical microscope using commercially available image processing software and dividing the total area by the area of the entire field of view.
In the case of a PET bottle, for example, a structure containing a plurality of bubbles in the image forming area can be formed by using a preform impregnated with nitrogen, carbon dioxide, or the like under high pressure during biaxial stretch blow molding.
When the pressure inside the bubble is higher than atmospheric pressure, it explodes and disappears. When the pressure inside the bubble is lower than atmospheric pressure, it shrinks. In either case, the scattering intensity weakens and the visible light transmittance increases.
It is preferable to have the bubbles concentrated near the surface in the thickness direction of the container body in order to maintain the strength of the container.

The image forming region preferably has a structure containing a crystalline phase.
The crystalline phase strongly scatters visible light, resulting in a low transmittance. Some of the scattered light is emitted outside the container, but most of it is absorbed within the container after multiple scattering.
By heating and rapidly cooling the crystalline phase-containing region with a laser, the crystalline phase becomes more likely to become amorphous. This method allows for the formation of images with higher contrast than the conventional method of irradiating a transparent amorphous phase with a laser to change its shape or crystallize it.
When the container is a PET bottle, the crystalline phase can be produced by setting the mold temperature within the crystallization temperature range during biaxial stretch blow molding and slowly cooling the bottle after blow molding.

It is preferable that the crystalline phase is spherulites, and that the average diameter of the spherulites in the laser-irradiated area when observed from the surface of the container body is smaller than the average diameter of the spherulites in the non-laser-irradiated area, since this allows for the formation of an image with higher contrast.
Spherulites are crystals that have grown into a spherical shape, and when observed using a polarizing microscope with transmitted illumination and crossed Nicols, they can be observed as a circular image containing crosshairs (conoscopic image).
The average diameter of the spherulites can be determined, for example, from the scattered light intensity distribution of a circular image including a crosshair (see Saito and Toyoda, Polymer Research Papers, Vol. 68, No. 6 (2011)).

It is preferable that the crystalline phase is spherulites, and that the number of spherulites per unit area in the laser-irradiated area when observed from the surface of the container body is smaller than the number of spherulites per unit area in the non-laser-irradiated area, in order to form an image with higher contrast.
Compared to a state in which crystals are densely arranged, a state in which spherulites are surrounded by an amorphous phase makes it easier to control the size of the spherulites with lower energy.
It is also possible to make the spherulites disappear. The state in which the conoscopic image completely disappears from the field of view is also one of the states in which the number of spherulites per unit area is small.
Compared to a state in which spherulites are closely arranged, a state in which spherulites are surrounded by an amorphous phase has the advantage that their size can be easily controlled with lower energy.

A _CO2 laser (wavelength: 10,600 nm), which is widely used for laser marking plastics such as polyethylene terephthalate (PET), is not suitable for obtaining high-resolution images with a line width of 100 μm or less. The wavelengths from visible light to near-infrared light are light that is not easily absorbed by the container such as PET, but are important for forming high-resolution images, and are therefore actively used in the present invention.

It has been reported that conventional laser marking using a _CO2 laser or the like generates harmful substances such as benzene and acetaldehyde (for example, P. E. Dyer, G. A. Oldershaw & J. Sidhu, _CO2 laser ablative etching of polyethylene terephthalate, Applied Physics B volume 48, pages 489-493 (1989)). However, in the present invention, the amount of harmful substances such as benzene and acetaldehyde generated can be reduced by using lower energy during writing.

This invention provides high energy efficiency because the visible light transmittance of the image formation area is low and laser light is easily absorbed. Furthermore, because writing can be done with low energy, the generation of harmful substances such as benzene and acetaldehyde during laser marking can be suppressed.

In the present invention, it is preferable that the container has a structure in which a sheet-like member on which an image forming area is formed is prepared in advance and this sheet-like member is attached to the periphery of the container body, thereby making it possible to form an image forming area on the container body without performing mold processing or complicating the management of temperature and time during molding.
The sheet-like member can be attached to the periphery of the container body using, for example, an adhesive.
By using the same material for the sheet-like member as for the container body, recyclability can be improved.

(Containment body)
The storage body of the present invention comprises the storage container of the present invention, an item stored in the storage container, and a sealing means for sealing the item in the storage container.

<Contents>
The contents may be, for example, liquids, gases, granular solids, etc. Examples of liquids include water, tea, coffee, black tea, soft drinks, etc. When the contents are liquid beverages, they are often clear, white, black, brown, yellow, or other colors.

<Sealing means>
The sealing means is a means for sealing the contents in the container, and is sometimes called a "container cap." There are no particular restrictions on the material, shape, size, structure, color, etc. of the sealing means, and they can be selected appropriately depending on the purpose.

The material of the sealing means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include resin, glass, metal, ceramics, etc. Among these, resin is preferred from the viewpoint of moldability.
The resin for the sealing means may be the same as the resin for the body of the container.
The color of the sealing means may be, for example, opaque and transparent.
The shape and size of the sealing means are not particularly limited as long as they are capable of sealing (closing) the opening of the container body, and can be appropriately selected depending on the purpose.

The structure of the sealing means is not particularly limited and can be selected appropriately depending on the purpose, but for example, it is preferable that it has a first part that separates from the container body when opened and a second part that remains in the container body.
The side surface of the first portion is preferably uneven so as to prevent the hand from slipping when opening the package, while the side surface of the second portion is preferably flat without any unevenness.

(Storage container manufacturing device and storage container manufacturing method)
The storage container manufacturing apparatus of the present invention is an apparatus for manufacturing the storage container of the present invention, and has a heating means for forming a visible region, and further has other means as necessary.
The heating means is preferably a laser irradiation device.

A method for manufacturing a storage container of the present invention is a method for manufacturing a storage container of the present invention, comprising: a first step for forming an image forming area; and a second step for forming a visible area overlapping the image forming area,
The first and second steps are performed by laser irradiation.

Generally, the shorter the pulse width of a laser light source, the higher the cost. Since the laser irradiation in the first step of forming the image formation area is primarily intended for laser ablation, it is preferable to use a light source with a pulse width of 1 μs or less, that is, in the nanosecond, picosecond, or femtosecond range. In contrast, the laser irradiation in the second step of forming a visible area overlapping the image formation area is primarily intended for heating and melting the irradiated area, so a light source with a pulse width in the microsecond or nanosecond range can be used. It is preferable to make the pulse width of the laser light irradiated in the second step longer than the pulse width of the laser light irradiated in the first step, as this reduces the cost of the device.

Generally, the shorter the wavelength of a laser light source, the higher the cost. Since the laser irradiation in the first step of forming an image formation area is mainly for the purpose of laser ablation, it is preferable to use a light source with a wavelength in the ultraviolet to visible light range. In contrast, the laser irradiation in the second step of forming a visible area overlapping the image formation area is mainly for the purpose of heating and melting the irradiated area, so a light source with a wavelength in the visible to infrared range can be used.
It is preferable that the wavelength of the laser light irradiated in the second step is longer than the wavelength of the laser light irradiated in the first step, in order to reduce the cost of the apparatus.
The laser irradiation in the second step is preferably carried out with a carbon dioxide gas laser, since this allows for the formation of an image with higher contrast while reducing the cost of the apparatus.

(Container before image writing)
The storage container of the present invention before an image is written thereon is a storage container before the second step of forming a visible area by overlapping it with the image forming area in the above-described method for manufacturing a storage container of the present invention is performed.
According to the pre-image-written storage container of the present invention, when the image content, such as expiration date or serial number, is frequently changed, an image is written in the image formation area in the second step, and in the preceding second step, a pre-image-written storage container in which no image has been written in the image formation area can be used, thereby improving production efficiency.

Now, an embodiment of the present invention will be described in detail with reference to the drawings. Note that in each drawing, the same components are given the same reference numerals, and duplicate explanations may be omitted. Furthermore, the number, position, shape, etc. of the following components are not limited to this embodiment, and may be of any number, position, shape, etc. that is preferable for implementing the present invention.

First Embodiment
Fig. 1 is a schematic diagram showing an example of a storage container according to the first embodiment. In the storage container 1 shown in Fig. 1, an image 12 (visible area 11) is formed by laser irradiation in an image formation area 13 provided on a container body 10. In Fig. 1, 14 denotes a non-image formation area.

When the storage container 1 of the first embodiment is observed with a black background and white light illuminated from the surface side, the visible area 11 (laser-irradiated area) has a high visible light transmittance, and therefore there is little light returning from the visible area 11, and therefore the storage container 1 appears darker than the image-forming area 13 (non-laser-irradiated area).
In contrast, Fig. 2 is a schematic diagram showing an example of a conventional storage container. In the storage container 101 shown in Fig. 2, the image 112 (laser irradiated portion) has a lower visible light transmittance than the container body 110 due to scattering, absorption, etc., and appears whiter due to reflected and scattered light.

The visible area 11 allows an image 12 to be visibly formed on the container body 10 .
The image 12 includes, for example, letters, symbols, figures, images, codes, etc., and specifically means information such as the name, ingredients, identification number, manufacturer name, manufacturing date and time, expiration date, barcode, QR code (registered trademark), recycle mark, or logo mark.
The image forming area 13 may be provided in a part of the container body 10 of the storage container 1 as shown in FIG. 1, but the entire container body 10 may be used as the image forming area 13 as shown in FIG.

The visible area 11 is formed by a collection of first patterns.
The image forming area 13 is formed by a collection of second patterns.
Here, an aggregate means a collection of multiple elements.
The first pattern assembly and the second pattern assembly preferably have a structure including recesses formed by melting the container body, or recesses and protrusions continuous with the recesses.

In the storage container 1 of the first embodiment, the visible area 11 has a higher visible light transmittance than the image formation area 13, and the image formation area 13 has a lower visible light transmittance than the container body 10.

Here, "high visible light transmittance" means high average transmittance in the visible light wavelength range, and it does not matter if the transmittance is inverted in some wavelength ranges. Visible light refers to light with a wavelength of 380 nm to 780 nm.
The wavelength of the laser for writing the image is preferably from visible light to near infrared light (wavelength: 780 nm to 2,500 nm).

_CO2 lasers (wavelength: 10,600 nm), which are widely used for laser marking plastics such as polyethylene terephthalate (PET), are not suitable for obtaining high-resolution images with line widths of 100 μm or less. Wavelengths ranging from visible light to near-infrared light are light that is not easily absorbed by containers such as PET, but are important for forming high-resolution images, and are therefore actively utilized in the present invention.

It has been reported that conventional laser marking using a _CO2 laser or the like generates harmful substances such as benzene and acetaldehyde (for example, P. E. Dyer, G. A. Oldershaw & J. Sidhu, _CO2 laser ablative etching of polyethylene terephthalate, Applied Physics B volume 48, pages 489-493 (1989)). However, in the present invention, the amount of harmful substances such as benzene and acetaldehyde generated can be reduced by using lower energy when writing an image.

In the storage container 1 according to the first embodiment, the visible light transmittance of the image formation area 13 is low, making it easy for the laser to be absorbed, resulting in high laser energy efficiency. Furthermore, because laser writing is possible with low energy, the generation of harmful substances such as benzene and acetaldehyde during laser marking can be suppressed.

Second Embodiment
FIG. 4 is a schematic diagram showing an example of a container according to the second embodiment, in which the image forming region 13 has a structure including a crystalline phase 21 .
As shown in Figure 4, an image formation area 13 for forming an image with a laser is provided on the surface of a container body 10 of a storage container 1 (e.g., a PET bottle) according to the second embodiment, and the visible light transmittance is increased by changing the crystalline phase 21 of the image formation area 13 through irradiation with a laser beam 20, thereby forming an image.
When the container is a PET bottle, the crystalline phase 21 can be produced by setting the mold temperature within the crystallization temperature range during biaxial stretch blow molding and slowly cooling the PET bottle after blow molding.
Visible light is strongly scattered in the crystalline phase 21, resulting in a decrease in visible light transmittance. A portion of the scattered light is emitted to the outside of the container, but most of the light is absorbed within the container while being multiple-scattered.
The crystalline phase 21 is adjusted by utilizing the principle that crystals are easily converted to amorphous by heating and rapidly cooling a region containing the crystalline phase 21 with a laser. This allows for the formation of images with higher contrast than conventional methods in which a transparent amorphous phase is irradiated with a laser to change its shape or crystallize it.

It is preferable that the crystallinity of the visible region 11 be smaller than the crystallinity of the region other than the visible region of the container body 10, since this allows for the formation of an image with higher contrast.
Here, the degree of crystallinity can be measured by X-ray diffraction measurement, and it can be determined that the stronger the crystalline peak intensity, the higher the degree of crystallinity. Figure 5 is a graph showing the relationship between X-ray diffraction peak intensity and crystallinity.

As shown in Figure 6, spherulites 22 are crystals that have grown into a spherical shape. When observed under crossed Nicols illumination with a polarizing microscope, spherulites 22 can be observed as a circular image containing crosshairs (conoscopic image). The average diameter of the spherulites 22 can be measured from the scattered light intensity distribution of the circular image containing crosshairs (Saito, Toyoda, Polymer Research Papers, Vol. 68 No. 6 (2011)).
Compared to a state in which crystals are densely arranged, the size of spherulites surrounded by an amorphous phase is easier to control with lower energy.
It can be seen from FIG. 6 that the average diameter of the spherulites 22 in the laser irradiated portion of the image forming region 13 is smaller than the average diameter of the spherulites 22 in the non-laser irradiated portion.

It is also possible to make the spherulites disappear. The state in which the conoscopic image completely disappears from the field of view can also be considered a state in which the number of spherulites per unit area is low.
Fig. 7 is a diagram showing the spherulites 22 observed in the laser irradiated and non-laser irradiated areas of the image formation area 13. Fig. 7 shows that the number of spherulites 22 in the laser irradiated areas of the image formation area 13 is smaller than the number of spherulites 22 in the non-laser irradiated areas.

Third Embodiment
FIG. 8 is a schematic diagram showing an example of a storage container 1 according to a third embodiment, in which the image forming area 13 has a structure containing a plurality of bubbles 23 .
It is preferable that the image forming area contains multiple bubbles and that the area ratio of the bubbles in the visible area when observed from the surface of the container body is smaller than the area ratio of the bubbles in the image forming area, as this allows for the formation of an image with higher contrast.
The area ratio of all bubbles can be measured by measuring the total area of bubbles observable in a predetermined field of view with an optical microscope using commercially available image processing software and dividing it by the area of the entire field of view.

When the container is a PET bottle, a structure containing a plurality of bubbles can be produced by using a preform impregnated with nitrogen, carbon dioxide, or the like under high pressure during biaxial stretch blow molding.
When the pressure inside the bubble is higher than atmospheric pressure, the bubble bursts and disappears. When the pressure inside the bubble is lower than atmospheric pressure, the bubble shrinks. In either case, the scattering intensity weakens and the visible light transmittance increases.
It is preferable to have the bubbles concentrated near the surface in the thickness direction of the container body in order to maintain the strength of the container.
The storage container 1 according to the third embodiment has an image formation area 13 having a structure containing a plurality of bubbles 23, and therefore can form a high-contrast image with lower laser energy than the conventional method of irradiating a transparent amorphous phase with a laser to change its shape or crystallize it.

<Fourth embodiment>
FIG. 9 is a schematic diagram showing an example of a storage container 1 according to a fourth embodiment, in which the image forming area 13 has a structure including fine irregularities 24. As shown in FIG.
Methods for forming the fine uneven structure include, for example, chemical etching and mechanical etching. Among these, mechanical etching is preferred because it generates less environmental impact, such as waste liquid. Examples of mechanical etching include wet blasting and sand blasting. Furthermore, a storage container having a fine uneven structure can be obtained by forming a fine uneven structure on the surface of a molding die and transferring it using a die having the fine uneven structure.
It is preferable that the surface roughness of the visible area when observed from the surface of the container body is smaller than the surface roughness of the image forming area, since this allows for the formation of an image with higher contrast.
The surface roughness can be measured based on the arithmetic mean roughness Ra according to JIS B0601.
The storage container 1 according to the fourth embodiment has an image forming area 13 having a structure including fine irregularities 24, and therefore can form a high-contrast image with lower laser energy than the conventional method of irradiating a transparent amorphous phase with a laser to change its shape or crystallize it.

Fifth Embodiment
Figure 10 is a schematic diagram showing an example of a storage container 1 according to the fifth embodiment, in which a sheet-like member 25 having an image forming area 13 formed thereon is prepared in advance and then attached to the periphery of the container body 10.
The sheet-like member 25 has the image forming area according to the first to fourth embodiments formed thereon in advance.
The sheet-like member 25 can be attached to the periphery of the container body 10 using, for example, an adhesive.
By using the same material as that of the container body 10 as the material of the sheet-like member 25, the recyclability of the storage container can be improved.
According to the storage container 1 of the fifth embodiment, by attaching a sheet-like member 25 having an image forming area 13 to the periphery of the container body 10, a storage container 1 having an image forming area 13 can be obtained without performing mold processing or complicating the management of temperature and time during molding.

Sixth Embodiment
Fig. 11 is a schematic diagram showing an example of a container 2 according to the sixth embodiment, which contains an item 16. In Fig. 11, 15 denotes a sealing means for sealing the item in the container.
According to the container 2 of the sixth embodiment, particularly when the contents 16 are non-transparent, the non-laser-irradiated parts can be seen by the illumination color (scattered light), and the laser-irradiated parts can be seen by the color of the contents, thereby further improving visibility.

Seventh Embodiment
12 is a schematic diagram showing an example of the container 31 before an image is written thereon according to the seventh embodiment, in which 13 denotes an image forming area and 14 denotes a non-image forming area.
In the seventh embodiment, when the image contents, such as expiration date or serial number, are frequently changed, the image is written in the image forming area 13 in the final process, and in the preceding process, an image-free storage container 31 with no image written in the image forming area 13 is used, thereby improving production efficiency.

The present invention includes, for example, the following aspects.
<1> A container body and a visible area on the container body,
the visible area has a higher visible light transmittance than the container body,
an image is formed on the container body by the visible area;
The container is characterized in that the visible area is formed by a collection of first patterns.
<2> A container body, an image forming area on the container body, and a visible area,
the image forming area has a visible light transmittance lower than that of the container body;
the visible area has a higher visible light transmittance than the image forming area;
an image is formed on the container body by the visible area;
The container is characterized in that the visible area is formed by a collection of first patterns.
<3> The container according to <2>, wherein the image forming area is formed by a collection of second patterns.
<4> The storage container according to <3>, wherein at least one of the first pattern and the second pattern has a structure including a recess formed by melting the container body, or a recess and a protrusion continuous with the recess.
<5> The image forming area includes a plurality of bubbles,
A storage container described in any one of <2> to <4>, wherein the area ratio of the total bubbles in the visible area when observed from the surface of the container body is smaller than the area ratio of the total bubbles in the image forming area.
<6> The aggregate of the second patterns forming the image forming area is made of a fine uneven structure,
The storage container according to any one of <3> to <5>, wherein the surface roughness of the visible area when observed from the surface of the container body is smaller than the surface roughness of the image forming area.
<7> The storage container according to any one of <2> to <6>, wherein the image forming region contains a crystalline phase, the crystalline phase being spherulites, and the average diameter of the spherulites in the laser-irradiated portion when observed from the surface of the container body is smaller than the average diameter of the spherulites in the non-laser-irradiated portion.
<8> The storage container according to any one of <2> to <7>, wherein the image forming region contains a crystalline phase, the crystalline phase being spherulites, and the number of spherulites per unit area in the laser-irradiated portion when observed from the surface of the container body is smaller than the number of spherulites per unit area in the non-laser-irradiated portion.
<9> The storage container according to any one of <1> to <8>, wherein the crystallinity of the visible region is lower than the crystallinity of a region of the container body other than the visible region.
<10> The storage container according to any one of <2> to <8>, wherein a sheet-like member on which the image forming area is formed is prepared in advance and the sheet-like member is attached to the periphery of the container body.
<11> The storage container according to any one of <1> to <10>,
An object contained in the container;
a sealing means for sealing the contents in the container;
The container is characterized by having:
<12> An apparatus for manufacturing the storage container according to any one of <1> to <10>,
The manufacturing device for a storage container is characterized by having a heating means for forming a visible area.
<13> The storage container manufacturing device according to <12>, wherein the heating means is a laser irradiation device.
<14> A method for producing the storage container according to any one of <1> to <10>,
a first step for forming an imaging area;
a second step of forming a viewable area overlying the image forming area;
The method for manufacturing a storage container is characterized in that the first step and the second step are performed by laser irradiation.
<15> The method for manufacturing a storage container according to <14>, wherein a pulse width of the laser light irradiated in the second step is longer than a pulse width of the laser light irradiated in the first step.
<16> The method for manufacturing a storage container according to any one of <14> and <15>, wherein the wavelength of the laser light irradiated in the second step is longer than the wavelength of the laser light irradiated in the first step.
<17> The method for producing a storage container according to any one of <14> to <16>, wherein the laser irradiation in the second step is performed with a carbon dioxide laser.
<18> The method for producing a storage container according to any one of <14> to <17>, wherein the laser irradiation in the first step is performed with a pulsed laser having a pulse width of 1 μs or less.
<19> A storage container before an image is written thereon, which is a state before the second step in the method for manufacturing a storage container according to any one of <14> to <18> is performed.

The storage container described in any one of <1> to <10>, the storage body described in <11>, the storage container manufacturing device described in any one of <12> to <13>, the storage container manufacturing method described in any one of <14> to <18>, and the storage container before image writing described in <19> can solve various problems in the past and achieve the object of the present invention.

REFERENCE SIGNS LIST 1 Storage container 2 Storage body 10 Container body 11 Visible area 12 Image 13 Image-forming area 14 Non-image-forming area 15 Sealing means 16 Container 20 Laser beam 21 Crystalline phase 22 Spherulite 23 Bubbles 24 Fine irregularities 25 Sheet-like member 31 Storage container before image writing

Patent No. 4327240

Claims (6)

a container body, an image forming area on the container body, and a visible area;
the image forming area has a visible light transmittance lower than that of the container body;
the visible area has a higher visible light transmittance than the image forming area;
an image is formed on the container body by the visible area;
the visible area is formed by a collection of first patterns,
the imaging area includes a plurality of bubbles;
A container in which the area ratio of all bubbles in the visible region when observed from the surface of the container body is smaller than the area ratio of all bubbles in the image forming region. The container according to claim 1, wherein the image forming area is formed by a collection of second patterns. The storage container described in claim 2, wherein at least one of the first pattern and the second pattern has a structure including recesses formed by melting the container body, or recesses and protrusions continuous with the recesses. a container body, an image forming area on the container body, and a visible area;
the image forming area has a visible light transmittance lower than that of the container body;
the visible area has a higher visible light transmittance than the image forming area;
an image is formed on the container body by the visible area;
the visible area is formed by a collection of first patterns,
A storage container in which the image forming area and the visible area contain a crystalline phase, the crystalline phase being spherulites, and the average diameter of the spherulites in the visible area when observed from the surface of the container body is smaller than the average diameter of the spherulites in the image forming area . a container body, an image forming area on the container body, and a visible area;
the image forming area has a visible light transmittance lower than that of the container body;
the visible area has a higher visible light transmittance than the image forming area;
an image is formed on the container body by the visible area;
the visible area is formed by a collection of first patterns,
A storage container in which the image forming area and the visible area contain a crystalline phase, the crystalline phase being spherulites, and when observed from the surface of the container body, the number of spherulites per unit area in the visible area is smaller than the number of spherulites per unit area in the image forming area . A storage container according to any one of claims 1 to 5;
An object contained in the container;
a sealing means for sealing the contents in the container;
A container characterized by having: