JP2012131714A - Slow-releasable barrier material, method for producing the same, and packaging container using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a barrier material in which the penetration of penetration components such as drug components can be started after the passage of a prescribed time, and a packaging container using the same.SOLUTION: In the slow-releasable barrier material, permeation components start to penetrate after the passage of a prescribed time. The slow-releasable barrier material comprises a polyglycolic acid-based resin with the weight-average molecular weight of ≥70,000. The slow-releasable packaging container includes the slow-releasable barrier material at least in a part thereof.

Description

  The present invention relates to a slow-release barrier material in which a permeation component begins to permeate after a predetermined time, a method for producing the same, and a packaging container using the same.

  A technique for gradually releasing a drug component is known as a technique for exerting the effect (medicine effect) of a drug component such as a fragrance, insect repellent, agricultural chemical, and fertilizer stably for a long time. As a sustained-release preparation using such a technique, for example, a sustained-release preparation (JP-A-2005-75762 (Patent Document 1)) in which a component that suppresses the release of the drug component is blended with the drug component, Sustained release agent in which a porous substance coexists in a drug component (Japanese Patent Laid-Open No. 2005-307120 (Patent Document 2)), sustained release drug in a container capable of permeating or penetrating the drug component Material (Japanese Patent Laid-Open No. 2005-289941 (Patent Document 3)), a gas sustained-release preparation containing a volatile drug in a packaging container partially arranged with a sustained-release sheet having communication holes (Japanese Patent Laid-Open No. 2008-133228) Publication (Patent Document 4)) and the like are known.

  However, since these sustained-release preparations have a function of gradually releasing drug components from the beginning of use, it has been difficult to apply to drugs requiring delayed action such as delayed-acting fertilizers. .

JP 2005-75762 A JP-A-2005-307120 JP 2005-289941 A JP 2008-133228 A

  The present invention has been made in view of the above-described problems of the prior art, and a barrier material capable of starting permeation of a permeable component such as a drug component after a lapse of a predetermined time, a manufacturing method thereof, and the same The purpose is to provide a packaging container.

  As a result of intensive studies to achieve the above object, the inventors of the present invention include a film containing a polyglycolic acid resin, which has excellent barrier properties against oxygen, carbon dioxide, and aroma (organic vapor). It has been found that when the weight average molecular weight of the polyglycolic acid resin becomes smaller than a specific value (for example, 70,000), the barrier property of this film rapidly decreases. Therefore, the present inventors reduced the weight average molecular weight of the polyglycolic acid resin over time using the hydrolyzability of the polyglycolic acid resin, thereby allowing the polyglycolic acid resin to be removed after a predetermined time. It is found that the barrier properties of the contained barrier material are drastically decreased and the permeation of the chemical components such as fragrances, insect repellents, agricultural chemicals and fertilizers is started. As a result, it was found that the permeation start time of the drug component can be adjusted by controlling the above, and the present invention has been completed.

  That is, the delayed release barrier material of the present invention is a delayed release barrier material in which a permeation component starts to permeate after a predetermined time, and contains a polyglycolic acid resin having a weight average molecular weight of 70000 or more. To do. In such a slow-release barrier material, the content of the hydrolysis inhibitor with respect to 100 parts by mass of the polyglycolic acid resin is preferably 10 parts by mass or less.

  The method for producing a delayed release barrier material of the present invention is a method for producing a delayed release barrier material in which a permeation component starts to permeate after a predetermined time has elapsed, and the permeation start time until the permeation component begins to permeate is determined. The method is characterized in that the weight average molecular weight of the polyglycolic acid resin constituting at least a part of the slow-release barrier material is controlled in accordance with the permeation start time.

  Furthermore, in such a production method, when the delayed release barrier material further contains a hydrolysis inhibitor and / or a hydrolysis accelerator, the hydrolysis inhibitor and / or the hydrolysis accelerator. By controlling the content of, a delayed release barrier material having a desired permeation start time can be obtained.

  The delayed-release packaging container of the present invention is characterized in that the delayed-release barrier material of the present invention is provided at least in part. Further, the delayed-release preparation of the present invention comprises the delayed-release packaging container of the present invention and a drug component contained in the packaging container. Examples of the drug component include fragrances, insect repellents, and agricultural chemicals. And fertilizers.

  In the present invention, “slow release” means that the transmission amount of the transmission component changes with time as shown by the solid line in FIG. 1, that is, transmission of the transmission component is started until a predetermined time elapses. (Transmission amount = 0), meaning that the transmission component begins to transmit after a predetermined time. In addition, the permeation amount of the permeation component after the lapse of the predetermined time may increase rapidly as shown in FIG. 1, or may gradually increase like a sustained-release preparation.

  In the present invention, the time when the transmission component starts to transmit is referred to as “transmission start time”. This transmission start time can be obtained as follows. That is, in the graph showing the change over time in the transmission amount of the transmission component (horizontal axis: elapsed time, vertical axis: transmission amount), the two points where the change in the transmission amount of the transmission component with respect to the elapsed time is the largest are connected by a straight line. The point where the horizontal axis is extrapolated is defined as the transmission start time.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to obtain the delayed release barrier material which can start permeation | transmission of permeation | transmission components, such as a chemical | medical agent component, after a predetermined time progress, its manufacturing method, and a packaging container using the same.

It is a graph which shows an example of the concept of "slow release" concerning the present invention. 4 is a graph showing changes with time in the amount of limonene permeated in the PGA resin film obtained in Example 1. FIG. It is a graph which shows the relationship between the weight average molecular weight of the PGA resin of the PGA resin film obtained in Examples 2-9, and limonene permeation | transmission start time.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

<Slow release barrier material>
First, the delayed release barrier material of the present invention will be described. The slow-release barrier material of the present invention has a slow-release property in which a permeation component begins to permeate after a predetermined time, and has a weight-average molecular weight of 70000 or more (hereinafter referred to as “PGA-based resin”). (Also called). In addition, the weight average molecular weight of PGA-type resin is a value measured by gel permeation chromatography (GPC) and converted with standard polymethyl methacrylate.

  The slow-release barrier material of the present invention is a barrier material when the weight average molecular weight of the PGA resin is decreased with time by hydrolysis, so that the weight average molecular weight becomes smaller than a specific value (for example, 70000). By utilizing the rapid decrease in the barrier property, the delayed release property is manifested. In the hydrolysis of the PGA-based resin, as described later, the moisture in the packaged material contained in the slow-release packaging container using the slow-release barrier material of the present invention, or the slow-release packaging such as soil Moisture contained in the surrounding environment of the container is used. Further, a moisture-containing film may be attached to the delayed-release barrier material to supply moisture to the delayed-release barrier material. Since the PGA-based resin is not easily hydrolyzed by moisture in ordinary air, the barrier property of the delayed release barrier material of the present invention is that in ordinary air (that is, the amount of moisture supply source necessary for hydrolysis is If not) is retained.

(Polyglycolic acid resin)
There is no restriction | limiting in particular as PGA-type resin used for this invention, For example, following formula (1):

A glycolic acid homopolymer consisting only of glycolic acid repeating units represented by the formula (hereinafter referred to as “PGA homopolymer”, including a ring-opened polymer of glycolide which is a bimolecular cyclic ester of glycolic acid). And a polyglycolic acid copolymer containing glycolic acid repeating units (hereinafter referred to as “PGA copolymer”).

  The content of the glycolic acid repeating unit in the PGA copolymer is preferably 60% by mass or more. When the content of the glycolic acid repeating unit is less than the lower limit, the crystallinity of the PGA copolymer is lowered, and the barrier property and heat resistance of the slow-release barrier material tend to be lowered.

  Examples of the repeating unit other than the glycolic acid repeating unit in such a PGA copolymer include the following formulas (2) to (6):

The repeating unit represented is mentioned.

In said formula (2), p represents the integer of 1-10, q represents the integer of 0-10. Moreover, in said Formula (3), j represents the integer of 1-10. Further, in the above formula (4), ^{R 1} and ^{R 2} each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, k is an integer of 2 to 10.

  By introducing 1% by mass or more of the repeating units represented by the above formulas (2) to (6), the melting point of the PGA resin can be lowered. As a result, the processing temperature can be lowered, and the melting Thermal decomposition during processing can be reduced. Furthermore, it is possible to improve the processability by controlling the crystallization rate of the PGA resin. However, from the viewpoint of crystallinity and hydrolyzability of the PGA resin, the upper limit of the content of the repeating unit represented by the formulas (2) to (6) is preferably 40% by mass or less.

  The PGA homopolymer used in the present invention can be synthesized by dehydration polycondensation of glycolic acid, dealcoholization polycondensation of glycolic acid alkyl ester, ring-opening polymerization of glycolide, and the like. Preferably, it is synthesized by ring-opening polymerization carried out by heating to a temperature of about 120 to 250 ° C. in the presence of a polymerization catalyst such as a tin compound, titanium compound, aluminum compound, zirconium compound or antimony compound. Is preferred. Such ring-opening polymerization can be carried out by either bulk polymerization or solution polymerization.

  Moreover, the PGA copolymer can be synthesized by using a comonomer in combination in the polycondensation reaction or the ring-opening polymerization reaction. Such comonomers include ethylene oxalate (ie, 1,4-dioxane-2,3-dione), lactides, lactones (eg, β-propiolactone, β-butyrolactone, β-pivalolactone, γ- Butyrolactone, δ-valerolactone, β-methyl-δ-valerolactone, ε-caprolactone, etc.), carbonates (eg, trimethylene carbonate, etc.), ethers (eg, 1,3-dioxane, etc.), ether esters ( For example, cyclic monomers such as dioxanone), amides (such as ε-caprolactam); hydroxycarboxylic acids such as lactic acid, 3-hydroxypropanoic acid, 3-hydroxybutanoic acid, 4-hydroxybutanoic acid, 6-hydroxycaproic acid or Its alkyl ester; ethylene glycol, 1 Aliphatic diols such as 1,4-butanediol; succinic acid, and aliphatic dicarboxylic acids or their alkyl esters such as adipic acid. These comonomers may be used individually by 1 type, or may use 2 or more types together. Of these comonomers, a cyclic monomer and a hydroxycarboxylic acid are preferred from the viewpoint that a PGA copolymer that is easy to copolymerize and has excellent physical properties can be obtained.

  Such PGA-type resin may be used individually by 1 type, or may use 2 or more types together. The weight average molecular weight of the PGA resin used in the present invention is 70000 or more. When the weight average molecular weight of the PGA-based resin is less than 70000, the barrier property against the permeation component is low even at the beginning of use (immediately after packaging), and it is difficult to use it as a raw material for the delayed-release barrier material.

The melt viscosity (temperature 270 ° C., shear rate 120 sec ⁻¹ ) of the PGA resin used in the present invention is preferably 300 to 10,000 Pa · s, more preferably 400 to 8,000 Pa · s, and more preferably 500 to 5 1,000 Pa · s is particularly preferable. Furthermore, the melting point of the PGA resin is preferably 200 ° C. or higher, and more preferably 210 ° C. or higher.

  In the present invention, such a PGA-based resin may be used alone, but within a range not impairing the object of the present invention, an inorganic filler, other thermoplastic resin, plasticizer, etc. are added to the PGA-based resin. You may use as a mix | blended PGA-type resin composition. In addition, PGA-based resins and PGA-based resin compositions include heat stabilizers, light stabilizers, moisture-proofing agents, waterproofing agents, water repellents, lubricants, mold release agents, coupling agents, oxygen absorbers as necessary. Various additives such as pigments and dyes can be contained.

(Hydrolysis inhibitor)
The delayed release barrier material of the present invention preferably contains no hydrolysis inhibitor, but may contain a hydrolysis inhibitor in order to delay the permeation start time of the permeation component. However, the content is preferably 10 parts by mass or less and more preferably 3 parts by mass or less with respect to 100 parts by mass of the PGA resin. When the content of the hydrolysis inhibitor exceeds the above upper limit, the hydrolysis rate of the PGA resin becomes too slow, the decrease in the weight average molecular weight of the PGA resin does not proceed, and the delayed release property of the barrier material is difficult to express. Tend to be.

  As such a hydrolysis inhibitor, a carboxyl group blocking agent known as a water resistance improver for aliphatic polyesters can be used. As such a carboxyl group blocking agent, for example, N, N Carbodiimide compounds including monocarbodiimide and polycarbodiimide compounds such as -2,6-diisopropylphenylcarbodiimide, 2,2'-m-phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline) Oxazoline compounds such as 2-phenyl-2-oxazoline and styrene / isopropenyl-2-oxazoline; oxazine compounds such as 2-methoxy-5,6-dihydro-4H-1,3-oxazine; N-glycidylphthalimide, cyclo Hexene oxide, triglycidyl isocyanurate Like epoxy compounds such as. Such a hydrolysis inhibitor may be used individually by 1 type, or may use 2 or more types together.

(Hydrolysis accelerator)
The delayed release barrier material of the present invention may contain a hydrolysis accelerator. The content is preferably 10 parts by mass or less and more preferably 3 parts by mass or less with respect to 100 parts by mass of the PGA resin. If the content of the hydrolysis accelerator exceeds the above upper limit, the hydrolysis rate of the PGA-based resin becomes too fast, and the permeation component begins to permeate immediately after the start of use, so it plays a role as a slow release barrier material. There is no tendency.

  Such a hydrolysis accelerator is not particularly limited as long as it can accelerate the hydrolysis reaction of the PGA resin, and examples thereof include amines such as ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide and the like. Examples include basic compounds such as hydroxides. Such hydrolysis accelerators may be used alone or in combination of two or more.

(Slow release barrier material and production method thereof)
The slow-release barrier material of the present invention contains a PGA-based resin having a weight average molecular weight of 70000 or more, and usually comprises a slow-release barrier layer containing such a PGA-based resin. Further, when the slow release barrier material of the present invention contains a hydrolysis inhibitor and / or a hydrolysis accelerator, the slow release barrier layer comprises a PGA resin, a hydrolysis inhibitor and / or a hydrolysis agent. It may be composed of one layer containing a decomposition accelerator, or may be composed of two layers of a layer containing a PGA resin and a layer containing a hydrolysis inhibitor and / or a hydrolysis accelerator, Two layers of a layer containing a PGA resin and a hydrolysis inhibitor and a layer containing a hydrolysis accelerator, a layer containing a PGA resin and a hydrolysis accelerator and a layer containing a hydrolysis inhibitor It may be a multilayer structure such as a two-layer structure.

  Since the thickness of such a slow-release barrier layer hardly affects the degree of the slow-release property, there is no particular limitation as long as the barrier property until the permeation start time is sufficiently developed, but 1-1000 μm. It is preferable that it is 1-500 micrometers. When the thickness of the delayed release barrier layer is less than the lower limit, the barrier property tends to be not sufficiently ensured until the permeation start time.On the other hand, when the upper limit is exceeded, the rigidity of the delayed release barrier material increases excessively. There is a tendency to suffer from the economic disadvantage of increasing the amount of packaging materials discarded.

  Such a slow-release barrier material of the present invention is preferably produced by the following method for producing a slow-release barrier material of the present invention. That is, in the method for producing a slow-release barrier material according to the present invention, first, a permeation start time until the permeation component begins to permeate the slow-release barrier material is set, and the initial required according to this permeation start time. The weight average molecular weight of the PGA resin is determined. For example, the relationship between the permeation start time and the initial weight average molecular weight of the PGA-based resin for each use environment condition (particularly, permeation component, temperature, humidity) of the slow-release barrier material was determined in advance and set according to this relationship The weight average molecular weight of the PGA-based resin required at the initial stage corresponding to the permeation start time and the use environment conditions is determined.

  Next, the PGA-based resin having the determined weight average molecular weight is formed into a predetermined shape such as a film shape or a sheet shape, whereby the delayed release barrier material of the present invention having a desired permeation start time can be obtained. . In addition, after molding a PGA resin having a weight average molecular weight larger than the determined weight average molecular weight into a predetermined shape, an electron beam or the like is applied to the PGA resin molded product (such as a PGA resin film or a PGA resin sheet). The delayed-release barrier material of the present invention having a desired permeation start time can also be produced by irradiating and reducing the weight average molecular weight of the PGA resin in the molded product to the determined weight average molecular weight. . There are no particular limitations on the molding conditions and molding method of the PGA-based resin, and known conditions and methods can be adopted as long as the weight average molecular weight of the PGA-based resin is maintained.

  In addition, when the slow-release barrier material of the present invention contains a hydrolysis inhibitor and / or a hydrolysis accelerator, first, the permeation start time and the PGA for each use environment condition of the slow-release barrier material in advance. The initial weight average molecular weight of the resin and the content of the hydrolysis inhibitor and / or hydrolysis accelerator are determined, and according to these relationships, the initial required PGA corresponding to the set permeation start time and use environment conditions The weight average molecular weight of the system resin and the content of the hydrolysis inhibitor and / or hydrolysis accelerator are determined. Next, a PGA resin composition having a predetermined weight average molecular weight and a predetermined amount of hydrolysis inhibitor and / or hydrolysis accelerator is molded into a predetermined shape, or a predetermined weight average molecular weight is obtained. A layer containing a PGA-based resin having a desired amount of onset time, such as by forming a layer containing a predetermined amount of hydrolysis inhibitor and / or hydrolysis accelerator thereon. A conductive barrier material can be produced.

  In this way, by controlling the weight average molecular weight of the PGA resin constituting the slow release barrier material, the content of the hydrolysis inhibitor and / or the hydrolysis accelerator, the slow release property having a desired permeation start time is obtained. A barrier material can be obtained.

  In addition, the slow release barrier material of the present invention is preferably used as an unstretched slow release barrier material without being subjected to a stretching treatment. In the stretched slow-release barrier material, the hydrolysis rate of the PGA-based resin becomes too slow, the decrease in the weight average molecular weight of the PGA-based resin does not proceed, and the slow-release property of the barrier material tends to be difficult to express. .

  The slow release barrier material of the present invention comprises only the slow release barrier layer containing the PGA resin according to the present invention and, if necessary, a hydrolysis inhibitor and / or a hydrolysis accelerator. However, it may be a multilayer structure in which another resin layer is provided on one side or both sides of the slow-release barrier layer. By providing the resin layer, it is possible to increase the strength of the slow-release barrier material or to prevent contact between the article to be packaged such as a permeable component and the slow-release barrier layer. Such a resin layer may be a single layer or a multilayer of two or more layers.

  Examples of the resin forming the resin layer include polyolefin resins such as polyethylene resins and polypropylene resins, ionomer resins, ethylene-vinyl acetate copolymer resins, ethylene-vinyl alcohol copolymer resins, polyvinyl alcohol resins, polystyrene resins, and polyamide resins. And polyester resins such as polyethylene terephthalate resin, polylactic acid resins, polycarbonate resins, polyurethane resins and the like. Such a resin layer needs to allow the permeation component to permeate quickly, and the resin layer on the water supply side needs to allow water to permeate quickly. Therefore, the resin constituting the resin layer is preferably a resin that allows a permeable component to permeate even when the resin layer is non-penetrating. It can be used by forming holes.

  Such a resin layer may be formed by coextrusion molding or co-injection molding together with the slow-release barrier layer, or may be formed by laminating a resin film on the slow-release barrier layer. The thickness of the resin layer is preferably 1 to 100 μm and more preferably 1 to 50 μm from the viewpoint of the strength and economics of the slow-release barrier material.

<Slow release packaging container>
Next, the delayed release packaging container of the present invention will be described. The delayed release packaging container of the present invention comprises at least a part of the delayed release barrier material of the present invention. That is, in the delayed-release packaging container of the present invention, as long as the delayed-release barrier material is disposed so as to be exposed to the inside and the outside, the entire packaging container is formed of the delayed-release barrier material. A part may be formed with the said slow-release barrier material, and the remaining part may be formed with the material which shows barrier property with respect to a permeation | transmission component.

  In the former delayed-release packaging container, the permeated component is released from the entire outer surface of the delayed-release packaging container after a predetermined time has elapsed. Although it is suitable as an adhesive packaging container, its use is not particularly limited.

  On the other hand, in the latter delayed-release packaging container, since a permeation component is released only from a portion formed by the delayed-release barrier material after a predetermined time has elapsed, for example, a delayed-release fragrance preparation or a delayed-release insect-repellent preparation described later, etc. Although it is suitable as a slow-release packaging container used in the above, its use is not particularly limited. In addition, there is no particular limitation on the material exhibiting barrier properties with respect to the permeable component. A material that exhibits a barrier property to the transmissive component is selected as appropriate.

  When a package containing a permeation component and moisture is encapsulated in a delayed-release packaging container having such a delayed-release barrier material, the moisture in the package is released from the delayed-release barrier material. The PGA resin is hydrolyzed and supplied to the conductive barrier layer, and the weight average molecular weight of the PGA resin decreases with time. When the weight average molecular weight of the PGA resin becomes smaller than a specific value after the elapse of the permeation start time, the barrier property of the slow release barrier material to the permeation component rapidly decreases, and the permeation component becomes the slow release barrier material. Begins to permeate and is released to the outside.

  In addition, when the object to be packaged does not contain moisture, for example, moisture on the outside of the packaging container such as soil or moisture on a film containing moisture stuck on the delayed-release barrier material is delayed. In the same manner as described above, the weight average molecular weight of the PGA resin decreases with time, and when the permeation start time is reached, the permeation component permeates the slow release barrier material. First, it is released to the outside.

<Slow release formulation>
The delayed-acting preparation of the present invention comprises such a delayed-release packaging container of the present invention and a drug component contained in the packaging container, and the drug component is a permeating component according to the present invention. Examples of such drug components include known drug components such as fragrances, insect repellents, agricultural chemicals, and fertilizers. Even if these drug components do not show delayed action, they are contained in the delayed-release packaging container of the present invention, so that the delayed-acting fragrance preparation, delayed-acting insect repellent preparation, delayed-acting agricultural chemical preparation, and delayed-acting fertilizer, respectively. It can be used as a preparation.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example. The weight average molecular weight and limonene concentration of the PGA resin were measured by the following methods.

(Weight average molecular weight of PGA resin)
The weight average molecular weight of the PGA resin was measured by gel permeation chromatography (GPC). Showa Denko Co., Ltd. “Shodex GPC-104” (registered trademark) as the GPC measuring device, and Showa Denko Co., Ltd. “HFIP-606M” and two pre-columns (Showa Denko Co., Ltd. “HFIP-”) G ”was connected in series, a 5 mM sodium trifluoroacetate / hexafluoroisopropanol solution was used as the eluent, and a differential refractive index (RI) detector was used as the detector. The column temperature was 40 ° C., the eluent flow rate. The molecular weight was calibrated using standard polymethyl methacrylate (manufactured by Showa Denko KK).

(Limonene concentration)
Limonene concentration was measured by a gas chromatography mass spectrometer (GC / MS). As a GC / MS measuring device, “7890A / 5975C” manufactured by Agilent Technologies, “HP-5MS” manufactured by Agilent Technologies, Ltd. was used as a column, and helium was used as a carrier gas. The carrier gas flow rate was set at 1 ml / min. The column temperature was held at 150 ° C. for 2.2 minutes.

Example 1
PGA homopolymer (manufactured by Kureha Co., Ltd., weight average molecular weight (Mw): 201000, melt viscosity (temperature 270 ° C., shear rate 120 sec ⁻¹ ): 596 Pa · s, melting point: 220 ° C.) A PGA resin composition was prepared by adding 0.5 part by mass of -2,6-diisopropylphenylcarbodiimide (CDI), and melt-extruded to prepare a PGA resin film having a thickness of 15 μm.

  Next, 10 ml of limonene was added as a fragrance to a cylindrical flat bottom separable flask (capacity 200 ml), and a beaker (capacity 10 ml) containing 3 ml of water was further added. The PGA resin film was put on the opening of the separable flask, and then a separable cover (capacity 170 ml) was attached and fixed with a clamp. Thereafter, a rubber plug was attached to the mouth of the separable cover and sealed.

  Thus, the separable flask which enclosed limonene and water was left still in 50 degreeC oven. The relative humidity in the separable flask at this time is 100% RH. Limonene that penetrated the PGA resin film was measured by measuring the limonene concentration according to the above method by inserting a gas tight syringe into the rubber plug of the separable cover mouth every predetermined time, collecting the headspace gas from the PGA resin film. The amount was determined. The change with time in the amount of limonene permeation is shown in FIG.

  As is clear from the results shown in FIG. 2, when about 150 hours passed after the separable flask was left in an oven at 50 ° C., the amount of limonene permeated rapidly increased. Therefore, it was confirmed that the PGA resin film can be used as a slow-release barrier material in which a permeation component (limonene) begins to permeate after a predetermined time. When the separable cover was removed when the elapsed time reached about 300 hours, it was confirmed visually that the PGA resin film had a hole.

  Moreover, the limonene permeation | transmission start time of the said PGA resin film was calculated | required as follows. In other words, in the change over time of the amount of limonene permeation shown in FIG. 2, the two points having the largest slope of the change in the amount of permeation with respect to the elapsed time are connected by a straight line, and the point where the line intersects the horizontal axis is extrapolated It was time. As a result, the limonene permeation start time at a temperature of 50 ° C. and a relative humidity of 100% RH of the PGA resin film was 144 hours.

(Example 2)
The limonene permeation amount was measured in the same manner as in Example 1 except that the amount of water in the beaker was changed to 5 ml, and the stationary temperature of the separable flask was changed to 23 ° C., and a PGA resin film (PGA resin Mw = 201000, Limonene permeation start time was determined at a temperature of 23 ° C. and a relative humidity of 100% RH at a CDI content of 0.5 parts by mass. The result is shown in FIG.

(Examples 3 to 6)
A PGA resin film was produced in the same manner as in Example 1 except that PGA homopolymers of Mw = 175000, 149000, 123000, and 97000 were used instead of the PGA homopolymer of Mw = 201000. The amount of limonene permeation of these PGA resin films was measured in the same manner as in Example 2, and the temperature of the PGA resin film (Pw resin Mw = 175000, 149000, 123000, or 97000, CDI content = 0.5 parts by mass). Limonene permeation start time at 23 ° C. and relative humidity 100% RH was determined. The result is shown in FIG.

(Examples 7 to 9)
A PGA resin film was produced in the same manner as in Example 1 except that only PGA homopolymers having Mw = 175000, 140000, and 105000 were used instead of the PGA resin composition. The amount of permeation of limonene of these PGA resin films was measured in the same manner as in Example 2, and the temperature of the PGA resin film (PGA resin Mw = 175000, 140000, or 105000, no CDI added) was 23 ° C. and the relative humidity was 100% RH. Limonene permeation start time was determined. The result is shown in FIG.

  As is apparent from the results shown in FIG. 3, when a PGA resin having a weight average molecular weight of 70000 or more is used, the PGA resin film has a limonene permeation start time exceeding 0 hour and is used as a delayed release barrier material. It was confirmed that it was possible. Moreover, it turned out that the weight average molecular weight of PGA resin and a limonene permeation | transmission start time have a linear relationship. From this, it was confirmed that a slow release barrier material having a desired limonene permeation start time can be produced by controlling the weight average molecular weight of the PGA resin. Furthermore, it was confirmed that by adding CDI which is a hydrolysis inhibitor, the limonene permeation start time becomes longer and the limonene permeation start time can be adjusted.

  As described above, according to the delayed-release barrier material of the present invention, it is possible to start permeation of the transmissive component after a predetermined time has elapsed.

  Therefore, the delayed-release packaging container using the delayed-release barrier material of the present invention does not allow the permeation component as the contents to permeate until the permeation start time and allows permeation thereafter. It is useful as a packaging container used for delayed action preparations such as preparations, delayed action insect repellent preparations, delayed action agrochemical preparations and delayed action fertilizer preparations.

Claims (7)

  A slow-release barrier material which contains a polyglycolic acid resin having a weight average molecular weight of 70000 or more, which is a slow-release barrier material in which a permeation component begins to permeate after a predetermined time has elapsed.   The delayed-release barrier material according to claim 1, wherein the content of the hydrolysis inhibitor is 10 parts by mass or less with respect to 100 parts by mass of the polyglycolic acid resin. A method for producing a slow-release barrier material in which a permeation component begins to permeate after a predetermined time,
Setting a permeation start time until the permeation component begins to permeate, and controlling a weight average molecular weight of the polyglycolic acid resin constituting at least a part of the delayed release barrier material according to the permeation start time A method for producing a slow-release barrier material.   The delayed release barrier material further contains a hydrolysis inhibitor and / or a hydrolysis accelerator, and the content of the hydrolysis inhibitor and / or hydrolysis accelerator is controlled according to the permeation start time. The method for producing a delayed release barrier material according to claim 3.   A slow-release packaging container comprising at least a part of the slow-release barrier material according to claim 1.   A delayed-release preparation comprising the delayed-release packaging container according to claim 5 and a drug component contained in the packaging container.   The delayed-acting preparation according to claim 6, wherein the drug component is any one of a fragrance, an insect repellent, an agrochemical and a fertilizer.

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