JP2000006228A - Biodegradable resin container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain moisture of contents to fill from transmitting through the wall of a container and volatilizing by a method wherein a biodegradable resin container is made by molding a biodegradable resin, to which powders or fibers made of a substance having a specified coefficient of water absorption according to ASTM-D570 are added. SOLUTION: This biodegradable resin container 1 is produced by molding a biodegradable resin, to which a powder 2 made of a substance having the coefficient of water absorption according to ASTM-D570 or a standard testing method of the water absorbing characteristics of a resin by immersing the resin having a predetermined shape in the water under predetermined conditions for estimating the coefficient of water absorption of 3 or more is added. In this case, as that biodegradable resin, a polybutylene succinate-based resin, a copolymer of a butylene succinate and a butylene adipate, a copolymer of hydrobutylate and a hydroxybarillate, a polycaprolactam resin, a cellulose acetate-based resin, an aliphatic polyester such as a polyoxyacid including a polylactic acid or the like can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a biodegradable resin container, and more particularly to a biodegradable resin container having a high moisture barrier property.

[0002]

2. Description of the Related Art In addition to glass materials, containers for cosmetics and foods are easily processed.
Resins made of resin are often used because of their high chemical and physical stability and low cost. However, in recent years, the high stability of conventional resins has become a problem, and due to its indegradability, environmental pollution due to landfilling and incineration has become a problem.

[0003] From the viewpoint of preserving the natural environment, there is a strong demand for the development of a container using a resin that quickly decomposes and disappears after reaching its purpose and does not need to be collected or incinerated. Resins that enable such containers include biodegradable resins that can be incorporated into natural resource recycling processes and that can be degraded by microorganisms in soil or sea.

[0004] These resins are finally decomposed by biodegradation, such as acetic acid and succinic acid, which are one of the basic components of the energy conversion reaction of living organisms. It changes to the constituent substances of the circuit), simple organic acids, carbon dioxide and water, and renders them harmless. Therefore, if a container is manufactured from such a biodegradable resin,
After the purpose is achieved using the container, it can be naturally decomposed and eliminated without any means and without any adverse effect on the environment, such as by burying it in the soil as it is.

[0005]

However, when such a biodegradable resin is used for a container, a certain problem may occur. It relates to the permeability of liquid components such as water which these biodegradable resins have.

[0006] As the biodegradable resin, a polyester material produced by synthesis or microbial fermentation is usually selected and used based on the presence or absence of biodegradability. However, a polyester resin material is generally known as a resin for such a container, which has high permeation characteristics of contents such as water and has a defect in permeation characteristics of contents.

[0007] Among such polyester resin materials, those which have biodegradability and can be selected as biodegradable resins are already known to have particularly high permeability to water and alcohol. Although resin materials other than polyester resin materials have similar biodegradability, it is generally known that they have high permeability to moisture and alcohol, and have a common problem. Will be.

[0008] The problem caused by the extremely high moisture permeability of currently available biodegradable resins, that is, the problem caused by the low moisture barrier property, will be described. For example, in a container manufactured using the same, During long-term storage of the contents, the moisture of the contents permeates through the walls of the container and volatilizes and decreases. as a result,
The container itself may also deform. Further, the viscosity of the content increases, the pH value changes, and the like, which causes the quality of the content to change or deteriorate.

Such a phenomenon becomes a serious problem when the contents are, for example, cosmetics or foods. That is, for example, cosmetics need to exert an accurate and safe action on extremely sensitive objects such as human skin, and even if the change or deterioration in quality such as a change in pH value is slight, Very unfavorable. As a means for solving such a problem of the barrier property against moisture, it is conceivable to increase the wall thickness of the container using the biodegradable resin to reduce the permeability of moisture and the like.

However, in order to ensure the same permeability as other conventional containers having no biodegradability, it is presumed that it is necessary to increase the thickness of the container wall to more than 10 times the thickness of the conventional container. However, the basic advantages of using a resin as a material for the container, such as lightness, ease of handling, and low cost, are impaired, and cannot be a fundamental problem. Therefore, at present, there is a demand for expanding the range of use as a container in consideration of the environment, but its use and range of use are limited.

As described above, an object of the present invention is to provide a novel biodegradable resin container which solves the above problems. That is, an object of the present invention is to reduce moisture permeability of contents in a biodegradable resin container using a biodegradable resin, that is, to improve moisture barrier properties.

[0012] Another object of the present invention is to prevent a water content of a filling content from permeating through a container wall and volatilizing in a biodegradable resin container using a biodegradable resin. is there.

[0013]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above objects can be achieved by the following means. The invention according to claim 1 is characterized in that the biodegradable resin container is formed by molding a biodegradable resin to which a powder or fiber made of a substance having a water absorption of 3 or more according to ASTM D570 is added.

According to a second aspect of the present invention, there is provided the biodegradable resin container according to the first aspect, wherein the powder or fiber added to the biodegradable resin is porous. container. According to a third aspect of the present invention, in the biodegradable resin container according to the first or second aspect, the amount of powder or fiber added to the biodegradable resin is 0.1.
5 to 35% by weight.

According to a fourth aspect of the present invention, there is provided the biodegradable resin container according to any one of the first to third aspects, wherein the powder or the fiber added to the biodegradable resin is highly hydrophilic. It is a molecular substance. According to a fifth aspect of the present invention, in the biodegradable resin container according to any one of the first to third aspects, the powder or the fiber added to the biodegradable resin is a composition containing sugar. There is a feature.

According to a sixth aspect of the present invention, in the biodegradable resin container according to any one of the first to third aspects, the powder or fiber added to the biodegradable resin is an amino acid composition. It is characterized by being. The invention according to claim 7 is a biodegradable resin container having a multilayer structure,
It is characterized by using a biodegradable resin to which a powder or a fiber made of a substance having a water absorption of 3 or more according to ASTM D570 is added for an intermediate layer or an outer layer.

According to the first aspect of the present invention, the powder or fiber made of a substance having a water absorption of 3 or more according to ASTM D570 added to the biodegradable resin is added to the molded biodegradable resin container in a container wall portion. The inside of the container absorbs moisture, and the inside of the vessel wall portion of the container is brought into a state where the relative humidity shows a very large value close to 100% (moisture absorbing state).

Therefore, the inside of the container wall portion of the container has the same relative humidity as the inside of the container filled with the content containing the water component, and the relative humidity difference between the inside of the container wall and the inside of the container becomes zero. Get closer. That is, it is possible to place the water component inside the container in a state where it is difficult to volatilize. Therefore, it is possible to suppress the moisture of the content to be filled from passing through the vessel wall of the container and volatilize, and to provide a biodegradable resin container having a high moisture barrier property.

According to the second aspect of the present invention, the ASTM
Since the powder or fiber made of a substance having a water absorption of 3 or more according to D570 is porous, the ability to retain moisture is further enhanced, and the absorption of moisture is maintained, that is, it is difficult to volatilize. Therefore, the state of moisture absorption of the vessel wall is kept high and stable. Accordingly, it is possible to prevent the moisture of the content to be filled from passing through the vessel wall of the container and volatilize, and to provide a biodegradable resin container having a very high moisture barrier property stably.

According to the third aspect of the present invention, the amount of particles or fibers used in the biodegradable resin container is 0.5% by weight based on the weight of the biodegradable resin composition to which the particles or fibers are added. %, The moisture absorption effect of the particles or fibers becomes sufficient, the formation of a wet state inside the vessel wall of the container becomes sufficient, and the effect of enhancing the moisture barrier property of the biodegradable resin container becomes sufficient. It becomes possible.

Further, it is possible to reduce the blending amount of the particles or fibers to 35% by weight or less, which impairs the moldability at the time of manufacturing the container due to the added particles or fibers, and prevents the particles or fibers from absorbing moisture. It is possible to prevent the fibers from expanding and deforming the container. Therefore, it is possible to provide a biodegradable resin container which suppresses the moisture of the content to be filled from passing through the container wall and volatilizes, stably has an extremely high moisture barrier property, and has excellent moldability. Becomes

According to the present invention, it is possible to select a powder or a fiber to be added to the biodegradable resin from a substance having a high water absorption and being easily prepared.
Therefore, it is possible to suppress the moisture of the content to be filled from passing through the vessel wall of the container and volatilizing, stably have an extremely high moisture barrier property, and provide a low-cost biodegradable resin container having excellent moldability. Can be provided.

According to the present invention, the biodegradable resin constituting the inner layer and the like can be appropriately selected in combination with the outer layer or the intermediate layer having excellent moisture barrier properties. It is possible to expand the range of selection of the biodegradable resin constituting the container. That is, in combination with an outer layer or the like having excellent moisture barrier properties, by appropriately selecting the biodegradable resin constituting the inner layer or the like, the obtained biodegradable resin container has desired excellent properties as a container. It becomes possible to configure appropriately.

Therefore, a biodegradable resin container excellent in moldability, which suppresses the moisture of the content to be filled from permeating through the vessel wall and volatilizes, and has a very high moisture barrier property stably. It can be provided at low cost.

[0025]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view schematically showing a configuration of a biodegradable resin container according to a first embodiment of the present invention. Biodegradable resin container 1 according to the present invention
Is formed by molding a biodegradable resin to which powder 2 composed of a substance having a water absorption of 3 or more according to ASTM D570 is added. Therefore, as shown in FIG. 1, the powder 2 is dispersed in the vessel wall 3 of the container 1 made of biodegradable resin.

FIG. 2 is a longitudinal sectional view schematically showing a configuration of a biodegradable resin container according to a second embodiment of the present invention. The biodegradable resin container 11 according to the present invention comprises:
It is formed by molding a biodegradable resin to which fibers 12 made of a substance having a water absorption of 3 or more according to ASTM D570 are added. Therefore, as shown in FIG. 2, the container 12 made of biodegradable resin has a configuration in which the fibers 12 are dispersed in the vessel wall 13.

Here, the particles 2 and the fibers 12 usable in the biodegradable resin containers 1 and 11 according to the first and second embodiments of the present invention are made of a material having a water absorption of 3 or more according to ASTM D570. Become. ASTM D570 stands for A
STM (American Society for Testing and Material
s) This is a standard test method for the water absorption characteristics of a resin determined by s), in which a resin of a predetermined form is immersed in water under predetermined conditions, and the water absorption is evaluated. Therefore, the higher the obtained evaluation value, the higher the resin has a higher water absorption performance. The water absorption value according to ASTM D570 is often used by those skilled in the art as an indicator of the moisture permeability of a resin.

The biodegradable resin containers 1 and 11 according to the present invention having the above-described structure can prevent the moisture of the contents to be filled from passing through the container walls 3 and 13 and volatilize, and can provide a high moisture barrier. Has the property. The mechanism by which the biodegradable resin containers 1 and 11 according to the present invention exhibit high moisture barrier properties will be described.

The phenomenon that the water component in the contents filled in the container volatilizes outside the container basically depends on the relative humidity difference and the temperature between the inside of the container and the external environment outside the container. That is,
The higher the temperature and the greater the relative humidity difference, the more the water component volatilizes out of the container. At this time, if the humidity difference is zero even if the temperature is high, the water component does not volatilize outside the container, and the most fundamental factor is the relative humidity difference inside and outside the container.

Therefore, the container filled with the content containing the water component is filled so that the relative humidity difference between the inside and the outside of the container is close to zero with respect to the water component in order to prevent evaporation of water. It is desirable to create a situation. Such a situation
This is achieved by dispersing a water-containing powder or fiber in a resin constituting the container, that is, a biodegradable resin. This is because, by dispersing the water-containing powder or fiber, the inside of the vessel wall portion of the container has a state where the relative humidity shows a very large value close to 100% (moisture absorbing state). Thus, the inside of the container wall portion of the container has the same relative humidity as the inside of the container filled with the content containing the water component, and the relative humidity difference between the inside of the container wall and the inside of the container is close to zero.

At this time, the container wall constituting the container is located outside the container where the relative humidity is a very large value for the contents containing the water component inside the container. A filling situation is achieved in which the humidity difference is close to zero. Therefore, the water component inside the container is placed in a state where it is difficult to volatilize. In this case, the water absorbed by the hydrated powder or fiber is strongly retained by the hydrated powder or fiber, and is not easily volatilized. Naturally, it is far less likely to be volatilized than when simply filled in a conventional biodegradable resin container that easily permeates moisture and has low moisture barrier properties.

Therefore, the moisture is stably held inside the vessel wall portion of the container, and the above-mentioned moisture absorption state is maintained for a long time. Therefore, the filling condition in which the relative humidity difference between the inside and the outside of the container is close to zero is maintained, and the content in the biodegradable resin container is volatilized by the water, and in particular, the water permeates through the vessel wall of the container. Can be protected for a long time from the phenomenon of volatilization. At this time, when the water-containing powder or fiber is porous, the water holding capacity of the powder or fiber is further increased, and the powder or fiber absorbs more water, and the maintenance of the absorbed water, that is, the difficulty of volatilization is increased. It will be strong. Therefore, the above-mentioned moisture absorption state of the vessel wall is more highly and stably placed. Therefore, it is preferable to use a porous powder or fiber such as a spherical porous cellulose powder.

Next, components that can be used for the biodegradable resin containers 1 and 11 according to the first and second embodiments of the present invention, which exhibit high moisture barrier properties according to the above mechanism, will be sequentially described. . The biodegradable resin that can be used for the biodegradable resin containers 1 and 11 according to the first and second embodiments of the present invention has the biodegradability as described above, and the container is manufactured by molding. Anything is possible if possible.

Thus, aliphatic polyesters can be used. And specifically, as the aliphatic polyester,
Synthesis of polybutylene succinate resin, copolymer of butylene succinate and butylene adipate, copolymer of hydroxybutyrate and hydroxyvalerate, polycaprolactone resin, cellulose acetate resin and polyoxyacid including polylactic acid Polymers can be used due to their ease of processing and chemical stability. In addition, a β-hydroxybutyric acid polymer produced by microbial fermentation, and a copolymer of β-hydroxybutyric acid and β-hydroxyvaleric acid are used in view of their extremely high biodegradability, processability, and chemical stability. It is possible.

Further, a random copolymer of an aliphatic polyester and another general-purpose polymer such as nylon can be used. In addition, a polymer obtained by grafting a synthetic polymer such as polyethylene or polyvinyl alcohol to starch, which is a natural polymer, can be processed with biodegradability and can be used. At this time, the starch content is desirably 1 to 25% by weight based on the whole resin so that a container in which the obtained resin can maintain appropriate physical and chemical stability can be manufactured.

Next, substances having a water absorption of 3 or more according to ASTM D570 constituting the particles 2 and the fibers 12 usable in the biodegradable resin containers 1 and 11 according to the first and second embodiments of the present invention. Contains a hydrophilic polymer substance. More specifically, the water absorption by ASTM D570 is 8
Polyvinyl alcohol as 0, polyacrylate resin as 50, carboxymethyl cellulose as 20, and the like are included. In addition, a composition containing a sugar can be used. Specifically, a water absorption rate according to ASTM D570 is 3
0 is included.

At this time, porous powder of cellulose is generally commercially available and easily available, and can be easily used in the production of the biodegradable resin container according to the present invention. Therefore, it is most preferable as particles that can be used in the biodegradable resin containers 1 and 11 according to the first and second embodiments of the present invention. Further, an amino acid composition can be used, and specifically, a water absorption rate according to ASTM D570 is 5%.
A protein polysaccharide such as chitin chitosan having a water absorption of 5
A protein such as collagen which is 0 can be used.

Next, the sizes of the particles 2 and the fibers 12 that can be used in the biodegradable resin containers 1 and 11 according to the present invention are determined so that the moldability of the biodegradable resin containers 1 and 11 is not impaired. It is sufficient that the irregularities due to the particles 2 or the fibers 12 are not generated on the container or the container wall. More specifically, any material having an outer diameter smaller than the thickness of the container walls 3 and 13 of the biodegradable resin containers 1 and 11 to be molded may be used.

The amount of the particles 2 or fibers 12 that can be used in the biodegradable resin containers 1 and 11 according to the present invention is 0 based on the weight of the biodegradable resin composition to which they are added. It is desirably from 0.5 to 35% by weight. If the blending amount is less than 0.5% by weight, the moisture absorption effect of the particles 2 or the fibers 12 is not sufficient, the formation of a wet state inside the vessel wall of the container becomes insufficient, and the moisture barrier property of the biodegradable resin container is reduced. The effect of enhancing becomes insufficient. When the amount is 35% by weight or more, the moldability during the production of the container may be impaired due to the particles 2 or the fibers 12, and the particles 2 or the fibers 12 may expand due to moisture absorption. May occur, and the biodegradable resin container may be deformed.

Further, another embodiment of the biodegradable resin container according to the present invention will be described. The biodegradable resin container according to the present invention can be configured to have a two-layer structure or a multilayer structure of more than two layers. FIG. 3 is a longitudinal sectional view schematically showing a configuration of a biodegradable resin container having a two-layer structure according to a third embodiment of the present invention.

That is, the biodegradable resin container 21 according to the third embodiment of the present invention is a biodegradable resin container having a two-layer structure and is made of a substance having a water absorption of 3 or more according to ASTM D570. The biodegradable resin to which the powder or the fiber is added is used for the outer layer 22, and the biodegradable resin to which the powder or the fiber is not added is configured as the inner layer 23. Next, FIG. 4 is a longitudinal sectional view schematically showing a configuration of a biodegradable resin container having a three-layer structure according to a fourth embodiment of the present invention.

That is, the biodegradable resin container 31 according to the fourth embodiment of the present invention is a biodegradable resin container having a three-layer structure, and is made of a substance having a water absorption of 3 or more according to ASTM D570. The biodegradable resin to which powder or fiber is added is used for the intermediate layer 32, and the biodegradable resin to which no powder or fiber is added is configured as the inner layer 33 and the outer layer 34.

At this time, each of the biodegradable resin containers 21 and 31 according to the third and fourth embodiments of the present invention is used as the biodegradable resin and powder or fiber in the first and second embodiments. The same ones as used in the biodegradable resin containers 1 and 11 can be used. Therefore,
Both the biodegradable resin containers 21 and 31 according to the third and fourth embodiments of the present invention are made of a biodegradable resin to which a powder or a fiber made of a substance having a water absorption of 3 or more according to ASTM D570 is added. The vessel wall of the container is constituted by the layers 22 and 32, and the vessel wall portion is wetted similarly to the biodegradable resin containers 1 and 11 according to the first and second embodiments of the present invention. May indicate a state.

Therefore, the biodegradable resin containers 21 and 31 of the third and fourth embodiments according to the present invention are both the biodegradable resin containers 1 and 11 of the first and second embodiments.
With the same mechanism as described above, it has high moisture barrier properties. In the biodegradable resin container 21 according to the third embodiment of the present invention, the powder or fiber-free biodegradable resin constituting the inner layer 23 is added with the powder or fiber. Can be the same as the biodegradable resin,
It is also possible that they are different.

When the biodegradable resins are different from each other, the biodegradable resin constituting the inner layer 22 may be, for example, one having extremely excellent moldability or contacting the contents without considering the moisture barrier property. Even those that are chemically highly stable and have no concern of contaminating the contents, etc.,
Furthermore, the biodegradable resin constituting the outer layer 23 may be selected in consideration of only exhibiting the highest moisture barrier property when the powder or the fiber is added. Therefore, the range of choice of the resin constituting the biodegradable resin container can be expanded.

That is, by appropriately selecting the biodegradable resin constituting the inner layer in combination with the outer layer 23 having excellent moisture barrier properties, the obtained biodegradable resin container has desired excellent characteristics as a container. It can be configured as follows. Similarly, in the biodegradable resin container 31 according to the fourth embodiment of the present invention, the powder or fiber-free biodegradable resin constituting the inner layer 33 and the outer layer 34 forms the intermediate layer 32. It can be the same as the biodegradable resin to which the above-mentioned powder or fiber is added, or it can be different. Furthermore, the biodegradable resin forming the inner layer 33 can be the same as the biodegradable resin forming the outer layer 34, or can be different.

That is, by appropriately selecting the biodegradable resin constituting the inner layer 33 and the outer layer 34 in combination with the intermediate layer 32 having an excellent moisture barrier property, the resulting biodegradable resin container can be molded and molded. The container can be configured to have desired excellent characteristics as a container, such as a characteristic of stably storing contents. Next, the biodegradable resin containers 1, 11, 21, 3 according to the first to fourth embodiments are described.
Extrusion molding method, injection molding method,
A molding method for ordinary resin container production such as a blow molding method can be used.

Since the biodegradable resin containers 21 and 31 of the third and fourth embodiments according to the present invention have a multilayer structure, they are suitable for high-precision molding of a resin container having a multilayer structure. The use of injection blow molding and extrusion blow molding is preferred. In particular, extrusion blow molding enables continuous and efficient molding of a resin container having a multilayer structure, and its use is preferred.

Further, for molding of a biodegradable resin to which a powder or a fiber made of a substance having a water absorption of 3 or more according to ASTM D570 is added, the water absorption according to ASTM D570 is 3 along with the biodegradable resin to be used. Powder or fiber composed of the above substances, put into the molding machine used,
The biodegradable resin is melted and mixed with the powder or fiber, and the powder or fiber is sufficiently dispersed in the molten biodegradable resin, and then formed into a desired shape.

When the injection blow molding method or the extrusion blow molding method is used, the amount of AS satisfying a predetermined blending ratio together with the biodegradable resin to be used is placed in the hopper of each molding machine.
A powder or a fiber made of a substance having a water absorption of 3 or more according to TMD570 is charged. After the introduction, molding is carried out in the same manner as ordinary container molding. As described above, the biodegradable resin container according to the present invention is molded and manufactured.

Next, the biodegradable resin container according to the present invention will be described in more detail using examples.

[0052]

EXAMPLES According to the extrusion blow molding method, a biodegradable resin container as an example according to the present invention was manufactured. As a biodegradable resin, a copolymer of butylene succinate and butylene adipate was used, and a resin obtained by adding 5% by weight of a cellulose powder having a water absorption of 30 according to ASTM D570 was put into a hopper of an extrusion blow molding machine. A 50 ml bottle container was manufactured. A bottle container with excellent moldability was obtained.

Next, the obtained bottle container was filled with water through a port provided, the port was sealed, and the container was left under a temperature condition of 50 ° C. for 4 weeks. As a result, the loss of water filled in the container after 4 weeks was 8%. Next, as a comparative example of the biodegradable resin container according to the present invention, the same extrusion blow molding was performed using the same copolymer of butylene succinate and butylene adipate as in the example of the present invention without the addition of the cellulose powder. According to the method, a similar 50 ml bottle container was produced. Then, the obtained bottle container was filled with water through a port provided, the port was sealed, and the container was left under a temperature condition of 50 ° C. for 4 weeks.

As a result, the loss of water filled in the container as the comparative example after 4 weeks was 20%. From the above, it was found that the biodegradable resin container of the example according to the present invention has a high moisture barrier property.

[0055]

According to the present invention as described above, the following various effects can be realized. According to the first aspect of the present invention, it is possible to place the water component inside the container in a state where it is difficult to volatilize. Therefore, it is possible to suppress the moisture of the content to be filled from passing through the vessel wall of the container and volatilize, and to provide a biodegradable resin container having a high moisture barrier property.

According to the second aspect of the present invention, the state of moisture absorption of the vessel wall is kept high and stable. Accordingly, it is possible to prevent the moisture of the content to be filled from passing through the vessel wall of the container and volatilize, and to provide a biodegradable resin container having a very high moisture barrier property stably.

According to the third aspect of the invention, the effect of enhancing the moisture barrier property of the biodegradable resin container can be made sufficient. In addition, it is possible to prevent the moldability during the production of the container from being impaired. Therefore, it is possible to provide a biodegradable resin container which suppresses the moisture of the content to be filled from passing through the container wall and volatilizes, stably has an extremely high moisture barrier property, and has excellent moldability. Becomes

According to the invention as set forth in claims 4 to 6, it is possible to prevent the moisture of the contents to be filled from passing through the vessel wall of the container and volatilizing, and to have a very high moisture barrier property stably. It is possible to provide a biodegradable resin container excellent in moldability at low cost. According to the invention of claim 7, the biodegradable resin container obtained by appropriately selecting the biodegradable resin constituting the inner layer and the like in combination with the outer layer and the like having excellent moisture barrier properties is desirable. It is possible to appropriately configure so as to have excellent characteristics.

Therefore, a biodegradable resin container excellent in moldability, which suppresses the moisture of the content to be filled from passing through the vessel wall and volatilizes, and has a very high moisture barrier property stably. It can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view schematically showing a configuration of a biodegradable resin container according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view schematically showing a configuration of a biodegradable resin container according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view schematically showing a configuration of a biodegradable resin container having a two-layer structure according to a third embodiment of the present invention.

FIG. 4 is a longitudinal sectional view schematically showing a configuration of a biodegradable resin container having a three-layer structure according to a fourth embodiment of the present invention.

[Explanation of symbols]

 1,11,21,31 Biodegradable resin container 2 Powder 3,13 Container wall 12 Fiber 22,34 Outer layer 23,33 Inner layer 32 Middle layer

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Claims (7)

[Claims] 1. A biodegradable resin container formed by molding a biodegradable resin to which a powder or a fiber made of a substance having a water absorption of 3 or more according to ASTM D570 is added. 2. The biodegradable resin container according to claim 1, wherein the powder or fiber added to the biodegradable resin is porous. 3. The biodegradable resin container according to claim 1, wherein the amount of powder or fiber added to the biodegradable resin is 0.5 to 35% by weight. A biodegradable resin container characterized by the following. 4. The biodegradable resin container according to claim 1, wherein the powder or the fiber added to the biodegradable resin is a hydrophilic polymer substance. Characteristic biodegradable resin container. 5. The biodegradable resin container according to claim 1, wherein the powder or the fiber added to the biodegradable resin is a composition containing sugar. Characteristic biodegradable resin container. 6. The biodegradable resin container according to any one of claims 1 to 3, wherein the powder or fiber added to the biodegradable resin is an amino acid composition. Biodegradable resin container. 7. A biodegradable resin container having a multilayer structure, wherein a biodegradable resin to which a powder or a fiber made of a substance having a water absorption of 3 or more according to ASTM D570 is added is used for an intermediate layer or an outer layer. A biodegradable resin container characterized by being made.