JP7561726B2 - Resin Molding - Google Patents

Description

The present invention relates to a resin molded body.

JP 2019-515987 A (Patent Document 1) discloses a water-soluble film. This water-soluble film contains a blend of at least two different polyvinyl alcohol polymers (see Patent Document 1).

Special table 2019-515987 publication

Films or sheets that begin to release active ingredients after a certain period of time has passed since the start of use (films or sheets with sustained release properties) may be effective. Patent Document 1 does not disclose such films or sheets.

The present invention has been made to solve these problems, and its purpose is to provide a resin molded body (film or sheet) that is capable of releasing an active ingredient to the outside of the resin molded body after a certain period of time has passed since the start of use.

The resin molded body according to the present invention is mainly composed of a degradable resin that is decomposed by a specific factor. The resin molded body is a film or sheet. The resin molded body contains at least one type of carrier. The carrier adsorbs at least one type of active ingredient. When the carrier is exposed to the outside of the resin molded body due to the decomposition of the degradable resin, the active ingredient is released to the outside of the resin molded body.

In this resin molded body, the active ingredient remains within the resin molded body until the carrier is exposed to the outside of the resin molded body, and the active ingredient is released to the outside of the resin molded body as the carrier is exposed to the outside of the resin molded body. Therefore, with this resin molded body, the active ingredient can be kept within the resin molded body until a certain period of time has passed since the use of the resin molded body began, and the active ingredient can be released to the outside of the resin molded body after a certain period of time has passed.

In the above resin molded body, the degradable resin may be at least one type of resin selected from microbially produced polyesters, polyamino acids, polysaccharides, aliphatic polyesters, polyvinyl alcohol, polyacrylamide, carboxymethyl cellulose, resol-type phenolic resins, methylolated urea resins, methylolated melamine resins, and polyethylene oxide.

The resin molded body includes at least a first layer and a second layer laminated to the first layer, and in each of the first layer and the second layer, the degradable resin is a biodegradable resin, and the degree of biodegradability of the degradable resin in the first layer may be different from the degree of biodegradability of the degradable resin in the second layer.

According to this resin molded body, by making the biodegradability of the degradable resin in the first layer different from that in the second layer, it is possible to control the rate of change in the amount of exposed support after the start of use of the resin molded body. As a result, in this resin molded body, the transition of the release rate of the active ingredient after the start of use of the resin molded body becomes desired. Note that the biodegradability in this invention refers to the rate at which chemical substances, including the resin molded body described in this invention, are decomposed within a certain period of time. Methods for measuring biodegradability include OECD 301A, OECD 301C, OECD 301D, OECD 301F, OECD 302C, ISO 14855, JIS K 6905, JIS K 6951, JIS K 3363, etc., and the biodegradability can be evaluated by appropriately selecting an appropriate measurement method.

The resin molded body includes at least a first layer and a second layer laminated to the first layer, and in the first layer, the degradable resin may be a biodegradable resin, and in the second layer, the degradable resin may be a water-soluble resin.

With this resin molded body, by differentiating the type of degradable resin in the first layer from the type of degradable resin in the second layer, it is possible to control the rate of change in the amount of exposed carrier after the resin molded body starts to be used. As a result, in this resin molded body, the change in the release rate of the active ingredient after the resin molded body starts to be used can be as desired.

The resin molded body includes at least a first layer and a second layer laminated on the first layer, and the type of carrier contained in the first layer may be different from the type of carrier contained in the second layer.

In this resin molded product, the type of carrier contained in the first layer is different from the type of carrier contained in the second layer, so that the release rate of the active ingredient changes as desired after the resin molded product begins to be used.

In the above resin molded body, the active ingredient adsorbed to the carrier in the first layer may be different from the active ingredient adsorbed to the carrier in the second layer.

With this resin molded body, the active ingredient contained in the first layer is different from the active ingredient contained in the second layer, so multiple types of active ingredients can be released to the outside of the resin molded body.

The resin molded body includes at least a first layer and a second layer laminated on the first layer, and in the first layer, the decomposable resin is a water-soluble resin, and the first layer does not necessarily contain an active ingredient.

In this resin molded product, the first layer is formed from a water-soluble resin that does not contain any active ingredient, so the timing at which the active ingredient begins to be released after the resin molded product begins to be used is as desired.

In the above resin molded body, the decomposable resin of the second layer is a water-soluble resin, and the dissolution rate of the decomposable resin of the first layer may be different from the dissolution rate of the decomposable resin of the second layer.

In this resin molded product, the water-soluble resin in the first layer has a different dissolution rate from the water-soluble resin in the second layer, so that the timing at which the active ingredient starts to be released and the progress of the release rate after the resin molded product begins to be used are as desired. Note that the method and environment for measuring the dissolution rate in this invention can be selected as appropriate.

The resin molded body may have a protective film attached to at least one surface.

This resin molded body has a protective film attached to at least one surface, and the decomposition of the decomposable resin due to moisture and other factors is less likely to progress during storage of the resin molded body, so deterioration of the resin molded body can be suppressed. In addition, this resin molded body has a protective film attached to at least one surface, so the occurrence of blocking can be suppressed when the resin molded body is rolled up and stored.

The resin molded body may be housed in an aluminum moisture-proof bag.

This resin molding is housed in an aluminum moisture-proof bag, and the decomposition of the decomposable resin due to moisture and other factors during storage of the resin molding is less likely to progress, so deterioration of the resin molding can be suppressed.

The present invention provides a resin molded body (film or sheet) that can release an active ingredient to the outside of the resin molded body after a certain period of time has passed since the start of use.

FIG. 1 is a schematic cross-sectional view of a film according to a first embodiment. FIG. 2 is a diagram showing a schematic diagram of a state of a film after a certain period of time has elapsed since the start of use of the film. FIG. 11 is a schematic cross-sectional view of a film according to a second embodiment. FIG. 11 is a schematic cross-sectional view of a film according to a third embodiment. FIG. 13 is a schematic cross-sectional view of a film according to a fourth embodiment. FIG. 13 is a schematic cross-sectional view of a film according to a fifth embodiment. FIG. 23 is a schematic cross-sectional view of a film according to a sixth embodiment. FIG. 23 is a schematic cross-sectional view of a film according to a seventh embodiment. FIG. 2 is a diagram illustrating an example of a cross section of a film having a protective film attached to one surface thereof. FIG. 2 is a schematic diagram showing a film contained in a pouch. FIG. 2 is a schematic diagram showing a cross section of a film having a general-purpose resin layer formed around its outer periphery. FIG. 2 is a diagram showing a cross section of a film having a first pattern in which the areas of the resin layers in a plan view are different. 13 is a diagram showing a cross section of a film having a second pattern in which the areas of the resin layers in a plan view are different from each other. FIG. FIG. 2 is a schematic diagram showing a cross section of a film having a plurality of pores formed on the surface thereof. FIG. 1 is a graph showing changes in urea dissolution rate. FIG. 1 is a graph showing changes in the elution rate of potassium ions.

Below, an embodiment of one aspect of the present invention (hereinafter also referred to as "the present embodiment") will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are given the same reference numerals and their description will not be repeated. Also, each drawing is drawn in a schematic manner with objects appropriately omitted or exaggerated for ease of understanding.

[1. First embodiment]
<1-1. Film structure>
Fig. 1 is a schematic diagram showing a cross section of a film 10 according to the first embodiment. The film 10 is used, for example, by being buried in the ground. The film 10 is configured to release an active ingredient to the outside of the film 10 after a certain period of time has passed since the start of use of the film 10. In other words, the film 10 has a sustained release performance. For example, the thickness of the film 10 is less than 250 µm.

As shown in FIG. 1, the film 10 includes a resin layer 100. The resin layer 100 is mainly composed of a degradable resin that is decomposed by a specific factor. Examples of the degradable resin include biodegradable resins and water-soluble resins. A biodegradable resin is a resin that is decomposed into a low molecular weight compound that does not adversely affect the environment by the involvement of microorganisms in nature. Examples of the biodegradable resin include microbially produced polyesters, polyamino acids, polysaccharides, aliphatic polyesters, and polyvinyl alcohol. A water-soluble resin is a resin that is soluble in water. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylamide, and carboxymethyl cellulose. The degradable resin may be, for example, a resin that decomposes by thermal oxidation, a resin that decomposes by ultraviolet light, a resin that decomposes by radiation, or a resin that decomposes by oxidation. Other examples of the degradable resin include resol-type phenolic resins, methylolated urea resins, methylolated melamine resins, and polyethylene oxide.

In the film 10, the resin layer 100 contains at least one type of carrier 110. For example, an adsorbent porous body is used as the carrier 110. Examples of the adsorbent porous body include activated carbon, alumina, tubular hydrated aluminum silicate (for example, halloysite, montmorillonite, or kaolinite), silica gel, zeolite, layered double hydroxide (LDH), amorphous aluminum silicate, and cyclodextrin. The carrier 110 adsorbs at least one type of active ingredient. As the active ingredient, various ingredients can be used according to the application of the film 10. Examples of the active ingredient include fragrance ingredients, chemical fertilizer ingredients, antibacterial and antiviral ingredients, moisturizing ingredients, browning prevention ingredients, repellent ingredients, insecticidal and insect repellent ingredients, plant growth promoting ingredients, soil improving ingredients, enzymes, microorganisms, antioxidants, flame retardants, plasticizers, surfactants, etc.

Figure 2 is a schematic diagram showing the state of the film 10 after a certain period of time has elapsed since the film 10 was first used. With reference to Figure 2, for example, the decomposition of the resin layer 100 progresses as time elapses from the start of the use of the film 10. If the resin layer 100 is made of a biodegradable resin, for example, the resin layer 100 decomposes as time elapses after the film 10 is buried in the ground. The concept of "decomposition" of the resin layer 100 includes, for example, the "disintegration" and "dissolution" of the resin layer 100.

As the decomposition of the resin layer 100 progresses, the carrier 110 embedded within the resin layer 100 becomes exposed to the outside of the resin layer 100 (the outside of the film 10). For example, the carrier 110 may become exposed to the outside of the resin layer 100 through the collapsed portion C1 of the resin layer 100. As the carrier 110 becomes exposed to the outside of the resin layer 100, the active ingredient adsorbed by the carrier 110 is released to the outside of the film 10.

<1-2. Features>
As described above, in film 10 according to the first embodiment, the active ingredient remains within film 10 until carrier 110 is exposed to the outside of film 10, and the active ingredient is released to the outside of film 10 as carrier 110 is exposed to the outside of film 10. Thus, according to film 10, the active ingredient can be retained within film 10 until a certain period of time has passed since use of film 10 begins, and the active ingredient can be released to the outside of film 10 after the certain period of time has passed. In other words, film 10 has sustained release properties.

The film 10 is manufactured, for example, by extrusion molding (T-die method). Specifically, first, a support 110 that adsorbs the active ingredient is made, and then an extrusion molding machine is used to form a film using the support 110 and a degradable resin. For example, the film 10 is manufactured in this manner.

In the present embodiment 1, film 10 was a single-layer film. In contrast, the films in each of the embodiments 2-7 described below include multiple layers. Below, the differences from the present embodiment 1 will be mainly described, and the parts that are common to the present embodiment 1 will not be described repeatedly.

[2. Second embodiment]
<2-1. Film structure>
Fig. 3 is a schematic diagram showing a cross section of a film 10A according to the second embodiment. As shown in Fig. 3, the film 10A includes resin layers 100A1 and 100A2. The resin layer 100A1 is mainly composed of a biodegradable resin. The resin layer 100A2 is mainly composed of a different type of biodegradable resin from that of the resin layer 100A1. That is, the biodegradability of the biodegradable resin in the resin layer 100A1 is different from the biodegradability of the biodegradable resin in the resin layer 100A2.

The degree of biodegradation refers to the rate at which chemical substances, including the film 10A according to the second embodiment, are decomposed within a certain period of time. Methods for measuring the degree of biodegradation include OECD 301A, OECD 301C, OECD 301D, OECD 301F, OECD 302C, ISO 14855, JIS K 6905, JIS K 6951, JIS K 3363, etc., and the degree of biodegradation can be evaluated by appropriately selecting an appropriate measurement method.

Each of the resin layers 100A1 and 100A2 contains a carrier 110. The carriers 110 contained in the resin layers 100A1 and 100A2 may be of the same type or different types. An active ingredient is adsorbed on the carrier 110.

For example, after the biodegradable resin is placed in contact with microorganisms, a biodegradable resin with a high degree of biodegradability is degraded faster than a biodegradable resin with a low degree of biodegradability. In other words, the support 110 embedded in a biodegradable resin with a high degree of biodegradability is exposed to the outside of the biodegradable resin earlier than the support 110 embedded in a biodegradable resin with a low degree of biodegradability. Therefore, by appropriately selecting the type of biodegradable resin in which the support 110 is embedded, the timing at which the support 110 is exposed to the outside of the biodegradable resin can be adjusted.

Although film 10A is composed of two layers, it may be composed of three or more layers. For example, in film 10A, another resin layer 100A2 may be laminated on the surface of resin layer 100A1 on which resin layer 100A2 is not laminated. In addition, in film 10A, another resin layer 100A1 may be laminated on the surface of resin layer 100A2 on which resin layer 100A1 is not laminated.

<2-2. Features>
As described above, according to the film 10A of the second embodiment, by making the degree of biodegradability of the biodegradable resin in the resin layer 100A1 different from the degree of biodegradability of the biodegradable resin in the resin layer 100A2, it is possible to control the rate of change in the amount of exposed support 110 after the start of use of the film 10A. As a result, in the film 10A, the change in the release rate of the active ingredient after the start of use of the film 10A becomes as desired.

The film 10A can be manufactured, for example, by coextrusion, lamination, coating, printing, or a 3D printer.

3. Third embodiment
<3-1. Film structure>
Fig. 4 is a schematic diagram showing a cross section of a film 10B according to the third embodiment. As shown in Fig. 4, the film 10B includes resin layers 100B1 and 100B2. The resin layer 100B1 is mainly composed of a biodegradable resin. The resin layer 100B2 is mainly composed of a water-soluble resin. That is, the conditions under which the decomposable resin (biodegradable resin) decomposes in the resin layer 100B1 are different from the conditions under which the decomposable resin (water-soluble resin) decomposes in the resin layer 100B2.

Each of the resin layers 100B1 and 100B2 contains a support 110. The support 110 contained in the resin layers 100B1 and 100B2 may be of the same type or different types. An active ingredient is adsorbed on the support 110.

The decomposition rate of the resin layer 100B1 changes depending on the state of the microorganisms involved in the resin layer 100B1. On the other hand, the decomposition rate of the resin layer 100B2 changes depending on the amount of water supplied to the resin layer 100B2. Generally, water-soluble resins decompose faster than biodegradable resins. Therefore, by appropriately selecting the type of decomposable resin in which the support 110 is embedded to suit the environment in which the film 10B is used, the timing at which the support 110 is exposed to the outside of the film 10B can be adjusted.

Although film 10B is composed of two layers, it may be composed of three or more layers. For example, in film 10B, another resin layer 100B2 may be laminated on the surface of resin layer 100B1 on which resin layer 100B2 is not laminated. In addition, in film 10B, another resin layer 100B1 may be laminated on the surface of resin layer 100B2 on which resin layer 100B1 is not laminated.

<3-2. Features>
As described above, in the film 10B according to the third embodiment, by differentiating the type of degradable resin in the resin layer 100B1 (biodegradable resin) from the type of degradable resin in the resin layer 100B2 (water-soluble resin), it is possible to control the rate of change in the amount of exposed support 110 after the start of use of the film 10B. As a result, in the film 10B, the change in the release rate of the active ingredient after the start of use of the film 10B becomes as desired.

The film 10B can be manufactured, for example, by coextrusion, lamination, coating, printing, or a 3D printer.

[4. Fourth embodiment]
<4-1. Film structure>
FIG. 5 is a diagram showing a cross section of a film 10C according to the fourth embodiment. As shown in FIG. 5, the film 10C includes resin layers 100C1 and 100C2. The resin layers 100C1 and 100C2 may be made of, for example, the same type of biodegradable resin as a main component. The resin layers 100C1 and 100C2 may be made of, for example, different types of biodegradable resin as a main component. The resin layers 100C1 and 100C2 may be made of, for example, the same type of water-soluble resin as a main component, or may be made of, for example, different types of water-soluble resin as a main component. One of the resin layers 100C1 and 100C2 may be made of a biodegradable resin as a main component, and the other of the resin layers 100C1 and 100C2 may be made of a water-soluble resin as a main component.

Resin layer 100C1 contains carrier 110C1, and resin layer 100C2 contains carrier 110C2. Carriers 110C1 and 110C2 are different types of carriers. Each of carriers 110C1 and 110C2 has an active ingredient adsorbed thereon.

For example, the time from when the carrier is exposed to the outside of film 10C until the active ingredient is released to the outside of film 10C varies depending on the type of carrier. For example, the active ingredient adsorbed to carrier 110C1 may be more likely to be released to the outside of film 10C than the active ingredient adsorbed to carrier 110C2. In other words, by differentiating the type of carrier (carrier 110C1) contained in resin layer 100C1 from the type of carrier (carrier 110C2) contained in resin layer 100C1, the release rate of the active ingredient after starting to use film 10C can be controlled.

Although film 10C is composed of two layers, it may be composed of three or more layers. For example, in film 10C, another resin layer 100C2 may be laminated on the surface of resin layer 100C1 on which resin layer 100C2 is not laminated. Also, in film 10C, another resin layer 100C1 may be laminated on the surface of resin layer 100C2 on which resin layer 100C1 is not laminated.

<4-2. Features>
As described above, in film 10C according to this embodiment 4, the type of support (support 110C1) contained in resin layer 100C1 is different from the type of support (support 110C2) contained in resin layer 100C1, so that the change in the release rate of the active ingredient after use of film 10C begins is as desired.

The film 10C can be manufactured, for example, by coextrusion, lamination, coating, printing, or a 3D printer.

[5. Fifth embodiment]
<5-1. Film structure>
FIG. 6 is a diagram showing a cross section of a film 10D according to the fifth embodiment. As shown in FIG. 6, the film 10D includes resin layers 100D1 and 100D2. The resin layers 100D1 and 100D2 may be made of, for example, the same type of biodegradable resin as a main component. The resin layers 100D1 and 100D2 may be made of, for example, different types of biodegradable resin as a main component. The resin layers 100D1 and 100D2 may be made of, for example, the same type of water-soluble resin as a main component, or may be made of, for example, different types of water-soluble resin as a main component. One of the resin layers 100D1 and 100D2 may be made of a biodegradable resin as a main component, and the other of the resin layers 100D1 and 100D2 may be made of a water-soluble resin as a main component.

Resin layer 100D1 contains carrier 110D1, and resin layer 100D2 contains carrier 110D2. Carriers 110D1 and 110D2 are the same type of carrier. Note that carriers 110D1 and 110D2 may be different types of carriers.

The active ingredient adsorbed to the support 110D1 is different from the active ingredient adsorbed to the support 110D2. Therefore, in the film 10D, the type of active ingredient released to the outside of the film 10D as the resin layer 100D2 decomposes is different from the type of active ingredient released to the outside of the film 10D as the resin layer 100D1 decomposes.

Although film 10D is composed of two layers, it may be composed of three or more layers. For example, in film 10D, another resin layer 100D2 may be laminated on the surface of resin layer 100D1 on which resin layer 100D2 is not laminated. In addition, in film 10D, another resin layer 100D1 may be laminated on the surface of resin layer 100D2 on which resin layer 100D1 is not laminated.

<5-2. Features>
As described above, according to film 10D, the active ingredient contained in resin layer 100D1 is different from the active ingredient contained in resin layer 100D2, so that multiple types of active ingredients can be released to the outside of film 10D.

The film 10D can be manufactured, for example, by coextrusion, lamination, coating, printing, or a 3D printer.

[6. Sixth embodiment]
<6-1. Film structure>
Fig. 7 is a schematic diagram showing a cross section of a film 10E according to the sixth embodiment. As shown in Fig. 7, the film 10E includes resin layers 100E1 and 100E2. The resin layer 100E1 is mainly composed of a water-soluble resin. The resin layer 100E2 is mainly composed of, for example, a biodegradable resin. Note that the resin layer 100E2 may be mainly composed of, for example, a water-soluble resin.

Resin layer 100E2 contains a carrier 110. The active ingredient is adsorbed to carrier 110. On the other hand, resin layer 100E1 does not contain carrier 110.

If film 10E is used in a state in which resin layer 100E1 comes into contact with a factor (e.g., moisture) that decomposes before resin layer 100E2 does, the active ingredient is not released to the outside of film 10E until resin layer 100E2 decomposes after resin layer 100E1 decomposes. In other words, with film 10E, the timing at which the release of the active ingredient begins after use of film 10E begins can be controlled by adjusting the thickness of resin layer 100E1 that does not contain carrier 110.

Although film 10E is composed of two layers, it may be composed of three or more layers. For example, in film 10E, another resin layer 100E1 may be laminated on the surface of resin layer 100E2 on which resin layer 100E1 is not laminated.

<6-2. Features>
As described above, in the film 10E, the resin layer 100E1 is formed of a water-soluble resin that does not contain an active ingredient, so that the release of the active ingredient begins at a desired timing after the start of use of the film 10E.

The film 10E can be manufactured, for example, by coextrusion, lamination, coating, printing, or a 3D printer.

[7. Seventh embodiment]
<7-1. Film structure>
FIG. 8 is a schematic diagram showing a cross section of a film 10F according to the seventh embodiment. As shown in FIG. 8, the film 10F includes resin layers 100F1 and 100F2. The resin layers 100F1 and 100F2 are mainly composed of water-soluble resins having different dissolution rates in water. The water solubility of the resin layer 100F1 is lower than that of the resin layer 100F2. That is, the resin layer 100F1 is less soluble in water than the resin layer 100F2. It should be noted that the method and environment for measuring the dissolution rate can be appropriately selected.

Resin layer 100F2 contains a carrier 110. The active ingredient is adsorbed to carrier 110. On the other hand, resin layer 100F1 does not contain carrier 110.

Because the water solubility of resin layer 100F1 is lower than that of resin layer 100F2, the time required for decomposition of resin layer 100F1 is longer than the time required for decomposition of resin layer 100F2. In other words, according to film 10F, the release start timing and release rate of the active ingredient can be adjusted by adjusting the water solubility of each of resin layers 100F1 and 100F2.

Although film 10F is composed of two layers, it may be composed of three or more layers. For example, in film 10F, another resin layer 100F1 may be laminated on the surface of resin layer 100F2 on which resin layer 100F1 is not laminated.

<7-2. Features>
As described above, in film 10F, a water-soluble resin that is less soluble in water than the water-soluble resin in resin layer 100F2 is used as the water-soluble resin in resin layer 100F1, so that the timing at which the active ingredient starts to be released and the progress of the release rate after use of film 10F begins are as desired.

The film 10F can be manufactured, for example, by coextrusion, lamination, coating, printing, or a 3D printer.

8. Modifications
The concept of the above embodiment is not limited to the embodiment described above. An example of a modified example to which the concept of the above embodiment can be applied will be described below.

<8-1>
In each of the above embodiments 1-7, a so-called film is disclosed. However, the techniques disclosed in each of the above embodiments 1-7 may be applied to a so-called sheet. A "sheet" refers to a thin plastic plate having a thickness of, for example, 250 μm or more. In other words, the films 10, 10A, 10B, 10C, 10D, 10E, and 10F disclosed in the above embodiments 1-7 may be "sheets."

<8-2>
In each of the above-mentioned embodiments 1 to 7, only one type of carrier is contained in the resin layer containing the carrier. However, the type of carrier contained in each resin layer containing the carrier does not necessarily have to be one type. For example, the type of carrier contained in each resin layer containing the carrier may be multiple types.

<8-3>
In each of the above embodiments 1 to 7, a protective film may be attached to at least one surface of the film.

Figure 9 is a schematic diagram showing an example of a cross section of film 10G with protective film 115 attached to one side. In film 10G, protective film 115 is attached to one side of resin layer 100G (degradable resin) containing carrier 110. According to film 10G, since protective film 115 is attached to at least one side, decomposition of resin layer 100G (degradable resin) due to moisture or the like during storage of film 10G is unlikely to progress, and deterioration of film 10G can be suppressed. Furthermore, according to film 10G, since protective film 115 is attached to at least one side, the occurrence of blocking can be suppressed when film 10G is rolled up and stored.

<8-4>
In each of the above embodiments 1 to 7, the film may be housed in a pouch having aluminum particles vapor-deposited on its surface (aluminum vapor-deposited pouch).

Figure 10 is a schematic diagram of film 10 housed in pouch 200. As shown in Figure 10, film 10 is housed in pouch 200. Fine aluminum particles are vapor-deposited on the surface of pouch 200. In other words, pouch 200 is an aluminum moisture-proof bag. As a result, film 10 is housed in pouch 200 with fine aluminum particles vapor-deposited on its surface, and since decomposition of the decomposable resin due to moisture, etc. during storage of film 10 is less likely to proceed, deterioration of film 10 can be suppressed.

<8-5>
In each of the above embodiments 1-7, a layer of a general-purpose resin may be formed on the outer periphery of the film, such as polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC).

Figure 11 is a schematic diagram showing a cross section of a film 10H in which a general-purpose resin layer 120 is formed on the outer periphery. As shown in Figure 11, the film 10H includes resin layers 100H1 and 100H2. Each of the resin layers 100H1 and 100H2 is mainly composed of a decomposable resin. Each of the resin layers 100H1 and 100H2 contains a carrier 110 that adsorbs an active ingredient. A general-purpose resin layer 120 is formed at a position that covers each of the outer periphery of the resin layers 100H1 and 100H2. Note that the general-purpose resin layer 120 may not be formed in a part of the outer periphery. Each of the resin layers 100H1 and 100H2 and the general-purpose resin layer 120 are in close contact with each other. This makes it possible to suppress the natural decomposition of each of the resin layers 100H1 and 100H2 at the outer periphery (edge portion) of the film 10H.

<8-6>
In each of the above-mentioned embodiments 2 to 7, the areas of the resin layers in a plan view do not necessarily have to be the same. For example, the area of one resin layer may be smaller than the area of the other resin layer.

Figure 12 is a schematic diagram showing a cross section of film 10I, which is a first pattern in which the areas of the resin layers in a plan view are different from each other. As shown in Figure 12, film 10I includes resin layers 100I1 and 100I2. Each of resin layers 100I1 and 100I2 is mainly composed of a degradable resin. Each of resin layers 100I1 and 100I2 contains carrier 110 that adsorbs an active ingredient. The area of resin layer 100I2 in a plan view is smaller than the area of resin layer 100I1 in a plan view. As a result, a step portion 130 is formed at the boundary between resin layer 100I1 and resin layer 100I2.

For example, assume that the decomposition factors of the resin layers 100I1 and 100I2 are in contact with the film 10I from the resin layer 100I2 side. In this case, if the areas of the resin layers 100I1 and 100I2 in a plan view are the same, the decomposition of the resin layer 100I1 does not start until the decomposition of the resin layer 100I2 is completed. In other words, the active ingredient embedded in the resin layer 100I1 is not released until the decomposition of the resin layer 100I2 is completed. However, in the film 10I, a step 130 is formed at the boundary between the resin layers 100I1 and 100I2. Therefore, even if the decomposition of the resin layer 100I2 is not completed, the decomposition of the resin layer 100I1 progresses at the step 130. As a result, the active ingredient embedded in the resin layer 100I1 can be released at a relatively early timing.

Figure 13 is a schematic diagram showing a cross section of film 10J, which is a second pattern in which the areas of the resin layers in a plan view are different from each other. As shown in Figure 13, film 10J includes resin layers 100J1 and 100J2. Each of resin layers 100J1 and 100J2 is mainly composed of a degradable resin. Each of resin layers 100J1 and 100J2 contains carrier 110 that adsorbs an active ingredient. Hole H1 is formed in resin layer 100J2. Therefore, the area of resin layer 100J2 in a plan view is smaller than the area of resin layer 100J1 in a plan view. Even with this configuration, the decomposition of resin layer 100J1 progresses in hole H1 before the decomposition of resin layer 100J2 is completed, so that the active ingredient embedded in resin layer 100J1 can be released at a relatively early timing.

<8-7>
In each of the above-mentioned embodiments 1 to 7, pores may be formed on the surface of the film. By forming pores on the surface of the film, the exposed area of the decomposable resin is increased, and decomposition of the decomposable resin can be promoted.

Figure 14 is a schematic diagram showing a cross section of a film 10K having multiple pores S1 formed on its surface. As shown in Figure 14, the film 10K includes a resin layer 100K. The resin layer 100K is mainly composed of a degradable resin. The resin layer 100K contains a carrier 110 that adsorbs an active ingredient. Multiple pores S1 are formed on the surface of the film 10K. Because multiple pores S1 are formed, the exposed area of the resin layer 100K is increased, accelerating the decomposition of the resin layer 100K.

<8-8>
The film in each of the above-mentioned embodiments 1-7 may be formed on a base film. The base film does not contain a decomposable resin as a main component. Therefore, after the film in each of the embodiments 1-7 is decomposed, only the base film remains. Since the film is formed on the base film, it is possible to suppress a decrease in the strength of the entire film during decomposition. In addition, since the base film remains when the decomposition of the decomposable resin is completed, it is possible to confirm that the decomposition of the decomposable resin is completed by collecting the remaining base film.

The above is an illustrative description of an embodiment of the present invention. In other words, the detailed description and the accompanying drawings are disclosed for the purpose of illustrative description. Therefore, the components described in the detailed description and the accompanying drawings may include components that are not essential for solving the problem. Therefore, just because these non-essential components are described in the detailed description and the accompanying drawings, it should not be immediately determined that these non-essential components are essential.

The above-described embodiment is merely an example of the present invention in every respect. Various improvements and modifications of the above-described embodiment are possible within the scope of the present invention. In other words, when implementing the present invention, specific configurations can be appropriately adopted according to the embodiment.

[9. Examples, etc.]
<9-1. Example 1>
The urea adsorption and sustained release film in Example 1 was obtained using the following materials and manufacturing procedures.

(9-1-1. Materials)
As the water-soluble resin, 100 parts of a 15 wt % aqueous solution of PVOH (Gohsenol GL-05) manufactured by Mitsubishi Chemical Corporation was prepared. As the carrier, 10 parts of activated carbon (Taiko S) manufactured by Futamura Chemical Co., Ltd. was prepared. As an active ingredient, 25 parts of water-soluble urea was prepared. As a release film, the "J6" type of silicone grade J series manufactured by Nippa Corporation was prepared.

(9-1-2. Manufacturing procedure)
First, (1) 25 g of urea was added to a 10 wt% aqueous solution of activated carbon and stirred uniformly to prepare a dispersion. (2) The prepared dispersion was placed in a vacuum oven set at 25°C, evacuated for 30 minutes, and left to stand for 24 hours in that state to allow the activated carbon to adsorb and support urea. (3) A predetermined amount of PVOH was added to the mixture prepared in (2), and the mixture was heated to 80°C while stirring to prepare a PVOH solution. (4) The PVOH solution was coated on a release film to a desired thickness, and dried in a 100°C environment for 10 minutes to obtain a urea adsorption and sustained release film.

(9-1-3. Measurement method)
The measurement device used was a liquid chromatograph (LC10) manufactured by Shimadzu Corporation. First, (1) the urea adsorption and sustained release film in Example 1 was immersed in water and allowed to stand, and the aqueous solution was sampled at predetermined times. (2) The strength of the sampled aqueous solution was measured by liquid chromatography, and the urea concentration in the aqueous solution was calculated using a calibration curve prepared for the urea standard solution. (3) The urea elution rate at the saturated concentration was set to 100%. The urea elution rate corresponding to the concentration calculated in (2) was calculated.

Figure 15 is a diagram showing the change in urea elution rate. Referring to Figure 15, the solid line shows the change in urea elution rate for Example 1. The dotted line shows the change in urea elution rate when urea is directly added to water. Through this experiment, it was found that the urea adsorption and sustained-release film in Example 1 required 15 hours for the urea elution rate to reach approximately 100%. In other words, it was confirmed that the urea adsorption and sustained-release film in Example 1 has sustained-release performance.

<9-2. Example 2>
The film in Example 2 was obtained by the following materials and manufacturing procedures.

(9-2-1. Materials)
As the biodegradable resin, "Materby" manufactured by Novamont SpA was prepared. As the carrier, activated carbon (Taiko S) manufactured by Futamura Chemical Co., Ltd. was prepared. As the active ingredient, potassium chloride was prepared. .

(9-2-2. Manufacturing procedure)
First, (1) activated carbon was immersed in a saturated aqueous potassium chloride solution and left for one day. The activated carbon was then filtered and dried to obtain potassium chloride-adsorbed activated carbon. (2) Then, Materby and potassium chloride-adsorbed activated carbon (5 wt% relative to Materby) were kneaded and formed into a film at 160°C using an extrusion molding machine. As a result, a film with a thickness of 250 μm was obtained.

(9-2-3. Measurement method)
The film in Example 2 was cut into 3 cm squares and immersed in an alkaline aqueous solution to carry out an accelerated decomposition test. The concentration of potassium ions in the immersion solution was measured every certain period of time using an aqueous solution of sodium tetraphenylborate. The elution rates of the components were measured by a precipitation method, and the maximum component content obtained from the calculated value was taken as 100%. The elution rates of the components were as shown in FIG.

Figure 16 shows the change in the dissolution rate of potassium ions. Referring to Figure 16, each plot shows the dissolution rate of potassium ions at each time point after a certain number of days have passed. The solid line is an approximation curve showing the change in the dissolution rate of potassium ions. Through this experiment, it was found that the film in Example 2 required about 3 days for the dissolution rate of potassium ions to reach, for example, 45%. In other words, it was confirmed that the film in Example 2 has sustained release properties.

10, 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10I, 10J, 10K film, 100, 100A1, 100A2, 100B1, 100B2, 100C1, 100C2, 100D1, 100D2, 100E1, 100E2, 100F1, 100F2, 100G1, 100G2, 100H1, 100H2, 100I1, 100I2, 100J1, 100J2, 100K resin layer, 110, 110C1, 110C2, 110D1, 110D2 support, 115 protective film, 120 general-purpose resin layer, 130 step portion, 200 pouch, C1 Collapsed section, H1 pore, S1 pore.

Claims (8)

A resin molded body mainly composed of a water-soluble resin,
The resin molded body is a film or a sheet,
The resin molded body contains at least one type of carrier,
The at least one support comprises activated carbon;
The activated carbon adsorbs at least one active ingredient,
The at least one active ingredient includes a chemical fertilizer ingredient,
The activated carbon is exposed to the outside of the resin molded body due to decomposition of the water-soluble resin, and in response, the chemical fertilizer component is released to the outside of the resin molded body. 2. The resin molded article according to claim 1, wherein the water-soluble resin is at least one type of resin selected from the group consisting of polysaccharides, polyvinyl alcohol, polyacrylamide, and carboxymethyl cellulose . The laminated ...
3. The resin molded article according to claim 1, wherein a type of the support contained in the first layer is different from a type of the support contained in the second layer. The resin molded article according to claim 3 , wherein the active ingredient adsorbed to the support in the first layer is different from the active ingredient adsorbed to the support in the second layer. The laminated ...
The resin molded article according to claim 1 or 2, wherein the first layer does not contain the active ingredient. The resin molded article according to claim 5 , wherein a dissolution rate of the water-soluble resin in the first layer is different from a dissolution rate of the water- soluble resin in the second layer. The resin molded article according to claim 1 , which has a protective film attached to at least one surface thereof. The resin molded product according to claim 1 , which is housed in an aluminum moisture-proof bag.