JP2011094008A - Aroma component-barrier film, aroma component-barrier multilayer film using the same, aroma component-barrier container and method for enhancing aroma component-barrier properties - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aroma component-barrier film that has sufficiently high barrier properties to an aroma component and is excellent in aroma retaining property even under high humidity conditions in particular. <P>SOLUTION: The aroma component-barrier film includes a polyglycolic acid resin. The aroma component permeability of the aroma component-barrier film to each of ethyl acetate, cyclohexane and 2-propanol as aroma components at a temperature of 30&deg;C and a relative humidity of 0% is less than 1.0 (&mu;g&times;10 &mu;m)/(m<SP>2</SP>&times;day&times;kPa). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an aroma component barrier film, an aroma component barrier multilayer film using the same, an aroma component barrier container, and a method for improving an aroma component barrier property.

  Conventionally, resin materials such as polyvinylidene chloride, polyvinyl alcohol, polycarbonate, polyacrylonitrile, polyethylene terephthalate (PET), and MX nylon have been used for packaging foods, beverages, skin lotions, and the like having aromatic components. It was.

  However, although these resin materials are excellent in terms of transparency, strength, moldability, heat resistance, etc., they are not necessarily sufficient in terms of aroma retention, and polyvinyl alcohol, MX nylon and the like are particularly high. There was a problem that the barrier property against the aroma component was lowered under humidity conditions.

  On the other hand, Japanese Patent Application Laid-Open No. 2004-299203 (Patent Document 1) discloses that a fragrance retention property is improved by using a polyethylene terephthalate film on which a metal oxide such as an aluminum foil is deposited.

  However, the aluminum vapor-deposited film described in Patent Document 1 has a problem that it is difficult to dispose of waste because of its high cost and lack of recyclability.

  Therefore, it has been desired to develop a film having a sufficiently high barrier property against an aroma component and excellent in aroma retaining property even under high humidity conditions and a container using the film.

JP 2004-299203 A

  The present invention has been made in view of the above-described problems of the prior art, and has a sufficiently high barrier property against an aroma component, and particularly an aroma component barrier film excellent in aroma retention even under high humidity conditions, and the same It is an object to provide an aroma component barrier multilayer film, an aroma component barrier container, and a method for improving an aroma component barrier property.

  As a result of intensive studies to achieve the above object, the present inventors have surprisingly found that a film containing a polyglycolic acid resin has a sufficiently high barrier property against aroma components, particularly under high humidity conditions. Was found to be excellent in perfume retention, and the present invention was completed.

  That is, the fragrance component barrier film of the present invention is characterized by containing a polyglycolic acid resin.

Moreover, as a fragrance component barrier film of this invention, the fragrance component permeability | transmittance in the temperature of 30 degreeC and relative humidity 0% with respect to ethyl acetate, cyclohexane, and 2-propanol as a fragrance component is 1.0 (microgram * 10 micrometer) / It is preferably less than (m ² · day · kPa).

Further, as the fragrance component barrier film of the present invention, the fragrance component permeability at 30 ° C. and 100% relative humidity with respect to ethyl acetate, cyclohexane and 2-propanol as the fragrance component is 1.0 (μg · 10 μm) / It is preferably less than (m ² · day · kPa).

  The fragrance component barrier multilayer film of the present invention comprises the fragrance component barrier film of the present invention.

  The fragrance component barrier container of the present invention is characterized by being formed by molding the fragrance component barrier multilayer film of the present invention.

  Furthermore, the method for improving the aroma component barrier property of the present invention is characterized by using the aroma component barrier film of the present invention.

  ADVANTAGE OF THE INVENTION According to the present invention, an aroma component barrier film having a sufficiently high barrier property against an aroma component, and particularly excellent in aroma retention even under high humidity conditions, and an aroma component barrier multilayer film and aroma component using the same It is possible to provide a barrier container and a method for improving the aroma component barrier property.

It is the schematic which shows the structure of the test device used in order to measure a fragrance component permeation | transmission amount. It is a graph which shows the daily change of the transmittance | permeability with respect to d-limonene of a PGA film and a PET film.

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

  The aroma component barrier film of the present invention contains a polyglycolic acid resin.

  First, the polyglycolic acid-based resin (hereinafter referred to as “PGA-based resin”) used in the aroma component barrier film of the present invention will be described.

As the PGA-based resin used in the present invention, the following formula (1):
_{- [O-CH 2 -C (} = O)] - (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”). Such PGA-type resin may be used individually by 1 type, or may use 2 or more types together.

  In the production of the PGA copolymer, copolymers used together with the glycolic acid monomer include ethylene oxalate (that is, 1,4-dioxane-2,3-dione), lactides, lactones (for example, β -Propiolactone, β-butyrolactone, β-pivalolactone, γ-butyrolactone, δ-valerolactone, β-methyl-δ-valerolactone, ε-caprolactone), carbonates (eg trimethylene carbonate), ethers (eg , 1,3-dioxane), ether esters (eg, dioxanone), amides (eg, ε-caprolactam) and the like; lactic acid, 3-hydroxypropanoic acid, 3-hydroxybutanoic acid, 4-hydroxybutanoic acid , Hydroxycarboxylic acids such as 6-hydroxycaproic acid, The alkyl ester; a substantially equimolar mixture of an aliphatic diol such as ethylene glycol or 1,4-butanediol and an aliphatic dicarboxylic acid such as succinic acid or adipic acid or an alkyl ester thereof. it can. These copolymers may be used alone or in combination of two or more. Of such copolymers, hydroxycarboxylic acid is preferred from the viewpoint of heat resistance.

  The catalyst used when the PGA resin is produced by ring-opening polymerization of glycolide includes tin compounds such as tin halide and tin organic carboxylate; titanium compounds such as alkoxy titanate; aluminum such as alkoxyaluminum. Known ring-opening polymerization catalysts such as zirconium compounds, zirconium compounds such as zirconium acetylacetone, and antimony compounds such as halogenated antimony and antimony oxide.

  The PGA-based resin can be produced by a conventionally known polymerization method, and the polymerization temperature is preferably 120 to 300 ° C, more preferably 130 to 250 ° C. When the polymerization temperature is less than the lower limit, the polymerization tends not to proceed sufficiently. On the other hand, when the polymerization temperature exceeds the upper limit, the produced resin tends to be thermally decomposed.

  The polymerization time for the PGA resin is preferably 2 minutes to 50 hours, and more preferably 3 minutes to 30 hours. When the polymerization time is less than the lower limit, the polymerization does not proceed sufficiently, whereas when the upper limit is exceeded, the generated resin tends to be colored.

  In the PGA resin used for the aroma component barrier film of the present invention, the content of the glycolic acid repeating unit represented by the formula (1) is preferably 70% by mass or more, and more preferably 80% by mass or more. When the content of the glycolic acid repeating unit is less than the lower limit, heat resistance and aroma component barrier property tend to be lowered.

  The PGA-based resin has a weight average molecular weight of preferably 30,000 to 800,000, and more preferably 50,000 to 500,000. If the weight average molecular weight of the PGA-based resin is less than the lower limit, the mechanical strength of a film described later tends to be lowered. On the other hand, if the upper limit is exceeded, melt extrusion or molding described later tends to be difficult. The weight average molecular weight is a polymethylmethacrylate conversion value measured by gel permeation chromatography (GPC).

In addition, the melt viscosity (temperature: 240 ° C., shear rate: 100 sec ⁻¹ ) of the PGA-based resin is preferably 100 to 10000 Pa · s, and more preferably 300 to 8000 Pa · s. When the melt viscosity is less than the lower limit, the mechanical strength of a film described later tends to be lowered. On the other hand, when the upper limit is exceeded, melt extrusion or molding described later tends to be difficult.

  In the present invention, the PGA-based resin may be used as it is, and if necessary, various additives such as a heat stabilizer, a terminal blocking agent, a plasticizer, a heat ray absorbent, and other thermoplastic resins are added. May be used.

  The heat stabilizer that can be used in the present invention is not limited as long as it can be added so that the dissolution stability of the PGA-based resin is improved and the fluctuation of the melt viscosity and the thermal decomposition hardly occur. Pentanetetraylbis (2,6-di-tert-butyl-4-methylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetra Phosphate ester having pentaerythritol skeleton structure such as irbis (octadecyl) phosphite; Phosphate alkyl ester having alkyl group (preferably having 8 to 24 carbon atoms) such as mono- or di-stearyl acid phosphate or a mixture thereof Or phosphorous acid alkyl ester; calcium carbonate, carbonic acid carbonate Metal carbonates such as rontium; bis [2- (2-hydroxybenzoyl) hydrazine] dodecanoic acid, N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine Hydrazine compounds having a —CONHNH—CO— unit such as; triazole compounds such as 3- (N-salicyloyl) amino-1,2,4-triazole; and triazine compounds. These heat stabilizers may be used alone or in combination of two or more.

  In the present invention, the addition amount of such a heat stabilizer is preferably 0.016 parts by mass or more with respect to 100 parts by mass of the PGA resin. When the addition amount of the heat stabilizer is less than the lower limit, the water resistance of a multilayer film and the like which will be described later is lowered due to the heat history during molding, and delamination tends to occur during long storage. On the other hand, although there is no restriction | limiting in particular as an upper limit of the addition amount of a heat stabilizer, 10 mass parts or less are preferable with respect to 100 mass parts of PGA-type resin. Even if the heat stabilizer is added in excess of the above upper limit, it is difficult to obtain the effect of increasing the addition amount due to saturation of the thermal stability, and the slippage controllability in the molding process tends to be reduced, as described later. There is a tendency that the transparency such as the above decreases.

  The end-capping agent that can be used in the present invention is not limited as long as it can add and seal the carboxy terminus of polyglycolic acid. N, N-2,6-diisopropylphenylcarbodiimide Carbodiimide compounds including monocarbodiimide and polycarbodiimide compounds such as 2,2′-m-phenylenebis (2-oxazoline), 2,2′-p-phenylenebis (2-oxazoline), 2-phenyl-2-oxazoline Oxazoline compounds such as styrene / isopropenyl-2-oxazoline; Oxazine compounds such as 2-methoxy-5,6-dihydro-4H-1,3-oxazine; N-glycidylphthalimide, cyclohexene oxide, triglycidyl isocyanurate And epoxy compounds. These end-capping agents may be used alone or in combination of two or more.

  In the present invention, the addition amount of such a terminal blocking agent is preferably 0.01 to 10 parts by mass with respect to 100 parts by mass of the PGA resin from the viewpoint of sufficiently sealing the carboxy terminal of polyglycolic acid. .

  Moreover, the mixing method in particular of the said PGA-type resin is not restrict | limited, For example, the melt-kneading method using a stirrer, a continuous kneader, an extruder, etc. is mentioned.

  In addition, it is preferable to further heat-treat after cooling after dissolution and kneading, from the viewpoint that the content of glycolide in the PGA-based resin can be reduced and a decrease in water resistance can be suppressed.

  Next, the aroma component barrier film of the present invention will be described. The fragrance component barrier film of the present invention is characterized by containing the PGA-based resin, and a stretched film or a heat-shrinkable film is preferable as an aspect thereof.

  The stretched film composed of the fragrance component barrier film of the present invention is prepared by press-molding or melt-extrusion pellets composed of the PGA-based resin, and stretching the resulting sheet while cooling, or After cooling, it is reheated and stretched as necessary, and then heat treated as necessary. Examples of the stretching method include a roll method, a tenter method, or a method of combining these methods to uniaxially stretch, sequentially biaxially stretch, or simultaneously biaxially stretch the sheet. At this time, the obtained film may be heat-set as necessary. Also, a biaxial stretching method can be employed by a inflation method using a circular die.

  The heat-shrinkable film comprising the fragrance component barrier film of the present invention can be produced by not heat-setting the stretched film or adjusting the heat-setting conditions.

  The fragrance component barrier film of the present invention is preferably a stretched film from the viewpoint of film strength, optical properties, fragrance component barrier properties, etc., as compared to an unstretched film, and a stretched film having an area magnification of 4 to 20 times. Is more preferable. If the area magnification is less than the lower limit, the whitening phenomenon of the film tends to occur and the transparency tends to decrease. On the other hand, when the area magnification exceeds the above upper limit, film strength, aroma component barrier property and the like tend to be lowered. In addition, an area magnification means the numerical value represented by the product of a uniaxial stretching magnification and a biaxial stretching magnification.

In the fragrance component barrier film of the present invention, the fragrance component permeability at 30 ° C. and 0% relative humidity with respect to ethyl acetate, cyclohexane and 2-propanol as the fragrance component is 1.0 (μg · 10 μm), respectively. / (M ² · day · kPa) is preferable.

Furthermore, in the fragrance component barrier film of the present invention, the fragrance component permeability at 30 ° C. and 100% relative humidity with respect to ethyl acetate, cyclohexane and 2-propanol as the fragrance component is 1.0 (μg · 10 μm), respectively. / (M ² · day · kPa) is preferable.

  In the fragrance component barrier film exceeding the upper limit of the transmittance at each relative humidity, when the contents are packaged, there is a possibility that the fragrance retention property with respect to the fragrance components of the contents may be insufficient.

  The aroma component permeability of the aroma component barrier film of the present invention is determined based on the following formula.

Aroma component permeability = (fragrance component permeation amount (μg) · film thickness (10 μm)) / (permeation area (m ² ) · partial pressure difference (kPa) · time (day)).

“Aroma component permeation amount (μg)” in the formula is a steady value described later measured by a tester shown in FIG. 1 (hereinafter referred to as “aroma component permeation amount measurement device”). The “film thickness” is the thickness of the film 4 described later, and the “permeation area (m ² )” is the area of the film 4 through which the fragrance component 2 described later is transmitted. The “partial pressure difference (kPa)” is the difference between the vapor pressure of the fragrance component in the measurement cell lower layer 1b described later and the vapor pressure of the fragrance component in the measurement cell upper layer 1a. "" Means unit time (one day).

  The outline of the fragrance component permeation measuring device and the method for measuring the fragrance component permeation amount will be described below.

As the measurement cell 1 shown in FIG. 1, a cell in which the volume of the lower layer 1b is 100 cm ³ and the volume of the upper layer 1a is 10 cm ³ is used. In the lower layer 1b of the cell, ethyl acetate, cyclohexane, 10 ml of any one of 2-propanol is put, dry air 3 is allowed to flow at 10 ml / min in the upper layer, and the aroma component barrier film of the present invention is sandwiched between the upper layer and the lower layer as the film 4. Then, the measurement cell 1 is placed in a thermostatic chamber 5 set at 30 ° C., and the dry air and aroma components flowing out from the upper layer every day are extracted with a gas tight syringe 6, and the amount of the aroma component in the dry air is determined. For example, it is measured using a gas chromatography mass spectrometer (hereinafter referred to as “GC / MS”), and the difference from the previous day's value falls within 1% of the measured value of the day (becomes a steady state). The measurement is continued under the conditions of a temperature of 30 ° C. and a relative humidity of 0%. The measured value (steady value) thus obtained is the “aroma component permeation amount” in the above formula, and by substituting it into the formula, the temperature of the aroma component barrier film of the present invention is 30 ° C., relative The aroma component permeability at a humidity of 100% is calculated.

  In addition, after the said measurement, the gas-tight syringe 6 which pulled out the plunger is 250 degreeC from the point that the aromatic component which remains in the gas-tight syringe 6 is removed and it does not always affect a measured value, for example. It is preferable to carry out heating washing after every measurement, such as piercing a needle heater heated to 10 minutes and flowing nitrogen gas at 0.1 MPa for 20 minutes.

  Further, the fragrance component permeability of the fragrance component barrier film of the present invention at a temperature of 30 ° C. and a relative humidity of 100% is, for example, a sponge wetted with water on both the upper and lower layers of the film 4 in the measurement cell 1. Further, it is calculated based on the permeation amount of the fragrance component measured under the added condition.

  Next, the aromatic component barrier multilayer film of the present invention will be described. The fragrance component barrier multilayer film of the present invention has two or more layers, and is not particularly limited as long as it comprises the fragrance component barrier film and another layer adjacent thereto. Examples of other layers adjacent to the aroma component barrier film include a layer made of a thermoplastic resin, a layer made of paper, and a layer made of an adhesive.

  Examples of the thermoplastic resin include polyester resins such as polyethylene terephthalate (PET) and polylactic acid, polyolefin resins such as polyethylene, polypropylene and ethylene / propylene copolymers, polystyrene resins such as polystyrene and styrene / butadiene copolymers, and polychlorinated resins. Examples include vinyl resins, polyvinylidene chloride resins, polyurethane resins, ethylene / vinyl alcohol resins, (meth) acrylic acid resins, nylon resins, sulfide resins, polycarbonate resins, and the like. These thermoplastic resins may be used alone or in combination of two or more. Among these, polyester resins are preferred from the viewpoint of obtaining a multilayer film satisfying both desired transparency and aroma component barrier property according to the use, and at least one of a diol component and a dicarboxylic acid component is an aromatic compound. An aromatic polyester-based resin is more preferable, and an aromatic polyester-based resin obtained from an aromatic dicarboxylic acid, for example, polyethylene terephthalate (PET) is particularly preferable.

  In such an aromatic component barrier multilayer film, the content of the PGA resin is preferably 1 to 10% on a mass basis. When the content of the PGA resin is less than the lower limit, the aroma component barrier property of the multilayer film tends to be lowered. On the other hand, when the upper limit is exceeded, the transparency of the multilayer film tends to decrease.

  Examples of the method for producing the multilayer film include a coextrusion method, a dry lamination method, an extrusion lamination method, and an inflation method.

  Next, the aroma component barrier container of the present invention will be described. The aroma component barrier container of the present invention is not particularly limited as long as it is formed by molding the aroma component barrier multilayer film.

  From the viewpoint of maintaining the strength of the container, molding processability, etc., the aromatic component barrier container of the present invention has at least one layer of the aromatic component barrier film (PGA-based resin layer) disposed as an intermediate layer, and the thermoplastic resin. It is preferable that the layer (thermoplastic resin layer) made of the above has a layer structure arranged as an inner and outer layer, and at least one layer of the aroma component barrier film in the resin layer containing the thermoplastic aromatic polyester More preferably, it is a multilayer blow molded container (blow molded bottle) containing The multilayer blow-molded container preferably has a specific “PET / PGA / PET” layer structure, but is not limited thereto.

  Moreover, the fragrance | flavor component barrier property container of this invention can interpose an adhesive bond layer between each layer if desired. In the case of a multilayer blow-molded container, from the viewpoint of heat resistance and molding processability, a container in which no adhesive layer is interposed between the thermoplastic resin layer and the aroma component barrier film is preferable.

  The aroma component barrier container of the present invention can be produced by a stretch blow molding method of a co-injected multilayer preform, a direct blow molding method of a co-extruded multilayer preform (multilayer parison), or the like.

  When producing a container by the co-injection stretch blow molding method, for example, a PGA resin and a thermoplastic resin are co-injected to form a bottomed multilayer preform, and then this multilayer preform is stretch blow molded And manufacturing a multilayer blow-molded container.

  In the manufacturing process of the multilayer preform, each mold melted through one gate is carried out by a single clamping operation in a cavity of a single preform mold using a molding machine having a plurality of injection cylinders. Co-inject resin. By the co-injection molding method, for example, the inner and outer layers are thermoplastic resin layers, the intermediate layer made of PGA-based resin layer is embedded in the thermoplastic resin layer, and the opening end consists only of the thermoplastic resin layer. A bottomed multilayer preform having a three-layered body portion can be obtained.

  The injection temperature (hot runner temperature) setting in the co-injection molding tends to deteriorate the melt fluidity of the resin to be injected if the injection temperature is too low, while if the injection temperature is too high, There is a tendency that thermal decomposition of the staying resin tends to occur. Therefore, in the line and barrel for injecting PGA-based resin, it is usually 200 to 310 ° C., preferably 230 to 300 ° C., and in the line and barrel for injecting other thermoplastic resin, it is usually 265 to 300 ° C. It is preferable that it is 270-295 degreeC.

  In the stretch blow molding step, the multilayer preform is adjusted to a temperature at which stretching can be performed, and then inserted into a cavity of a blow molding die, and a blown fluid such as air is blown to perform stretch blow molding. Stretch blow molding can be performed by either a hot parison method or a cold parison method, and the cold parison method is preferred from the viewpoint of temperature control. Here, the parison means a preform.

  For example, in order to stretch-blow mold a multilayer preform having a thermoplastic resin layer as an outer layer and an inner layer and a PGA-based resin layer as an intermediate layer by a cold parison method, first, the multilayer preform is sufficiently softened with an infrared heater or the like. Until heated. In this heating process, the thermoplastic resin layer is softened while maintaining an amorphous state, but the PGA resin layer is crystallized and whitened. At this time, if the crystallization of the PGA-based resin layer is not uniform, the thickness variation of the PGA-based resin layer after stretch blow molding becomes large or defects are likely to occur. It is necessary to crystallize.

  In order to uniformly crystallize the PGA-based resin layer, it is preferable to heat the multilayer preform so that the temperature of the multilayer preform is 90 ° C. or higher. More specifically, the heater power and heating time are adjusted so that the surface temperature of the thermoplastic resin layer (outer layer) at the center in the longitudinal direction of the multilayer preform is 90 to 110 ° C. However, the temperature in the vicinity of the mouth portion (where the support ring is located) of the multilayer preform may be set to be 10 to 30 ° C. lower than the surface temperature of the central portion in order to avoid deformation during stretch blow molding. preferable. If the temperature in the vicinity of the mouth (support ring) is lowered, the stretchability of the PGA-based resin layer at that portion is lowered, and voids and cracks are likely to occur. However, the transverse stretch ratio at a position 2 cm below the support ring ( If the size of the multilayer preform and bottle is set so that the outer diameter at 2 cm below the support ring after bottle molding / outer diameter at 2 cm below the support ring of the multilayer preform) is less than double, the void around the mouth And cracking can be suppressed. Here, the support ring means a ring that holds the mouth of the multilayer preform and the multilayer blow molded container at the time of co-injection molding and stretch blow molding.

  After the preliminary heating, a pressurized fluid such as compressed air is blown into the bottomed multilayer preform heated to the stretching temperature to be expanded and stretched.

  When the thermoplastic aromatic polyester resin is polyethylene terephthalate (PET) or the like, compressed air is blown into the multilayer preform at a temperature range of the glass transition temperature to the crystallization temperature, preferably 80 to 170 ° C. At this time, a stretching rod is inserted to biaxially stretch the multilayer preform in the axial (longitudinal) direction and the circumferential (transverse) direction. The glass transition temperature of the polyglycolic acid in the core layer is about 38 ° C., and it is easily stretched following the stretching of the thermoplastic polyester resin in the inner and outer layers.

  In particular, when polyethylene terephthalate (PET) or the like is used as the thermoplastic aromatic polyester resin, it is desirable to perform heat setting in order to improve heat resistance.

  The aromatic component gas barrier container of the present invention can be produced not only by the co-injection stretch blow molding method but also by a known bottle molding method such as a direct blow molding method. Further, the number of PGA-based resin layers can be not only one but also two or more.

  Next, the method for improving the aroma component barrier property of the present invention will be described. The method for improving the aroma component barrier property of the present invention is a method using the aroma component barrier property film.

  Examples of the method for improving the aroma component barrier property include a method for wrapping a known packaging film, a known sheet, or a known container with the aroma component barrier film or the aroma component barrier multilayer film, and the like. A method for adding the fragrance component barrier film to a packaging film, a known sheet, or a known container, or a known packaging film, a known sheet, or a known container in the fragrance component barrier container The method of putting is mentioned.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on a synthesis example, an Example, and a comparative example, this invention is not limited to a following example.

(Synthesis Example 1)
<Synthesis of PGA resin composition>
According to the method described in International Publication No. 2007/086563, high purity glycolide (manufactured by Kureha Co., Ltd.) as a raw material monomer and 1-dodecanol as an initiator to 0.2 mol% with respect to glycolide as a catalyst As follows, tin dichloride was charged into a reactor so as to be 30 ppm with respect to glycolide, and continuously polymerized at an average residence time of 20 minutes while being controlled at 200 to 210 ° C. The obtained polymer was taken out in the form of particles, and this was further subjected to solid phase polymerization at 170 ° C. for 3 hours while stirring in a nitrogen atmosphere. As a result, the final polymerization reaction rate is 99% or higher, the melting point is 222 ° C., the weight average molecular weight is 200,000, and the polydispersity (= weight average molecular weight / number average molecular weight) is 2.0. A resin was obtained. Next, the obtained PGA resin was continuously supplied to a twin-screw kneading extruder (“TEM41SS” manufactured by Toshiba Machine Co., Ltd.). The maximum temperature of the cylinder of the extruder was controlled to be 275 ° C., and at this time, the heat stabilizer (“ADK STAB AX-71” manufactured by Asahi Denka Kogyo Co., Ltd.) was added to 100 parts by mass of the PGA resin. At a ratio of 020 parts by mass, 0.3, part by mass of N, N-2,6-diisopropylphenylcarbodiimide (“DIPC” manufactured by Kawaguchi Chemical Industry Co., Ltd.) as an end-capping agent with respect to 100 parts by mass of PGA resin. The mixture was continuously supplied in a molten state at a ratio of 1, and melt kneaded. The strand discharged from the die of the extruder was cooled and cut using a pelletizer to obtain a pellet-like PGA resin composition. Furthermore, the obtained pellet was heat-treated at 170 ° C. for 17 hours, so that the glycolide content was 0.1% by mass or less and the crystallization temperature was 134 ° C.

Example 1
The pellet-like PGA-based resin composition obtained in Synthesis Example 1 was put into a compression molding machine (“ASYR5” manufactured by Shindo Metal Industry Co., Ltd.), and after 3 minutes of preheating, a temperature of 270 ° C. and a pressure of 100 kg · f / Cm ² for 3 minutes to obtain an unstretched sheet having a thickness of 200 μm. The obtained unstretched sheet was preheated at 60 ° C. for 30 seconds by a tenter method using a biaxial stretching apparatus (manufactured by Toyo Seiki Co., Ltd.) and stretched at a speed of 7 m / min. Then, heat treatment was performed at 120 ° C. for 2 minutes to obtain a PGA film having a thickness of 15 μm (hereinafter referred to as “PGA film (simultaneous biaxial stretching)”).

(Comparative Example 1)
Polyethylene terephthalate (PET) resin (product name: CB602S, manufactured by Totobo Co., Ltd.) is melted at a temperature of 280 ° C., and an extruder (manufactured by Pla Giken Co., Ltd.) and a T-die (manufactured by Pla Giken Co., Ltd.) are used. Extruded as an unstretched sheet and cooled on a cooling drum at 40 ° C., an unstretched sheet having a thickness of 120 μm was obtained at a film forming speed of 4 m / min. The obtained unstretched sheet is simultaneously biaxially stretched 3 × 3 times by a tenter method using a biaxial stretching apparatus (manufactured by Toyo Seiki Seisakusho Co., Ltd.) under the conditions of a temperature of 100 ° C. and a stretching speed of 7 m / min. Then, heat treatment was performed at 150 ° C. for 2 minutes to obtain a polyethylene terephthalate film having a thickness of 15 μm (hereinafter referred to as “PET film (simultaneous biaxial stretching)”).

<Aroma retention evaluation by sensory evaluation using d-limonene>
First, 10 ml of d-limonene (manufactured by Wako Pure Chemical Industries, Ltd., first grade) was placed in the lower part of the separable flask (volume: 300 cm ³ ), and the PGA film (simultaneous biaxial stretching) obtained in Example 1 or a comparative example. It was covered with the PET film obtained in 1 (simultaneous biaxial stretching), and an upper layer part (volume: 170 cm ³ ) of a separable flask was further attached thereon, and stored at a temperature of 30 ° C. 3 days after storage, 1 week later, 2 weeks later, the stopper of the upper part of the separable flask is opened, the three panelists sniff the air coming out, and the smell of d-limonene is not felt by the nose In the case of 1 point, 2 points were given for slight feeling, and 3 points were given for 3 cases in case of feeling firmly. This evaluation was repeated three times, the average value of the three results by three panelists was calculated, and the value was defined as the permeability (score) to the aroma component d-limonene of the PGA film. The obtained results are shown in FIG.

  As is apparent from the results shown in FIG. 2, in the sensory evaluation using the PGA film of the present invention (Example 1), no panelists felt the smell of d-limonene within 7 days from the start of the evaluation. In the 14 days after the evaluation was started, some panelists felt that smell, and the PGA film of the present invention was excellent in barrier properties against d-limonene. On the other hand, in the case of using a PET film (simultaneous biaxial stretching) (Comparative Example 1), most panelists felt the smell of d-limonene within 7 days from the start of evaluation, and started evaluation. 14 days later, the smell was strongly felt, and the barrier property of the PET film against d-limonene was inferior.

(Example 2)
The pellet-like PGA resin composition obtained in Synthesis Example 1 was melted at a temperature of 250 ° C. and unstretched using an extruder (Pura Giken Co., Ltd.) and a T die (Pura Giken Co., Ltd.). Extruded as a sheet and cooled on a cooling drum at 10 ° C., an unstretched sheet having a thickness of 200 μm was obtained at a film forming speed of 20 m / min. The obtained unstretched sheet was passed through a preheated roll at 40 ° C., and then longitudinally stretched 5.1 times between rolls with different peripheral speeds adjusted to 50 ° C. Next, the longitudinally stretched sheet is guided to a tenter-type lateral stretching machine, stretched 3.5 times at a preheating temperature of 50 ° C. and a stretching temperature of 55 ° C., and subjected to a heat treatment at 200 ° C. for 2 minutes to a thickness of about 10 μm. A PGA film (hereinafter referred to as “PGA film (sequential biaxial stretching)”) was obtained.

(Comparative Example 2)
A polyethylene terephthalate film (trade name: Lumirror P60, manufactured by Toray Industries, Inc., hereinafter referred to as “PET film (single-sided corona discharge treatment biaxial stretching)” having a thickness of about 10 μm subjected to single-sided corona discharge treatment biaxial stretching is prepared. did.

(Comparative Example 3)
3 times x 3 by simultaneous biaxial stretching in the same manner as in Comparative Example 1 except that nylon MXD6 resin (trade name: MX nylon 6007 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used instead of polyethylene terephthalate (PET) resin. A nylon MXD6 film (hereinafter referred to as “NyMXD6 film”) having a double size and a thickness of about 10 μm was obtained.

(Comparative Example 4)
Ethylene-vinyl alcohol copolymer resin film having a thickness of about 10 μm (manufactured by Kuraray Co., Ltd., trade name: EVAL, ethylene copolymerization ratio: 32 mol%, unstretched film, film cross-sectional area: 50 cm ² , hereinafter “EVOH-F film” I prepared.)

<Aroma component permeability evaluation under conditions of temperature 30 ° C. and relative humidity 0%>
PGA film obtained in Example 2 (sequential biaxial stretching), PET film prepared in Comparative Example 2 (single-sided corona discharge treatment biaxial stretching), NyMXD6 film prepared in Comparative Example 3 or EVOH prepared in Comparative Example 4 -F film is put into the above-mentioned fragrance component permeation measuring device, and as fragrance components, cyclohexane (manufactured by Wako Pure Chemical Industries, Ltd., for precision analysis), 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd., for precision analysis) ) And ethyl acetate (made by Wako Pure Chemical Industries, Ltd., special grade), using various compounds, the permeation amount of various fragrance components that permeate each film under the conditions of a temperature of 30 ° C. and a relative humidity of 0% according to the method described above. It was measured.

The measurement was performed as follows. That is, the collected dry air was injected into a column (HP-5MS; 30 m × 0.25 mm × 0.25 μm), and various aroma components were vaporized under the following conditions, with a column flow rate of 1 ml / min and a split ratio of 20. GC / MS (manufactured by Agilent Technologies, trade name: GC7890A / MSD5975C) was used to measure permeation amounts of various aromatic components.
1) Ethyl acetate oven start temperature: 50 ° C., start temperature hold time: 2.5 minutes 2) cyclohexane oven start temperature: 50 ° C., start temperature hold time: 2.5 minutes 3) 2-propanol oven start temperature: 40 ° C. Start temperature holding time: 2 minutes.

  Based on the measured values thus obtained, the transmittance for each aroma component of each film at a temperature of 30 ° C. and a relative humidity of 0% was calculated using the above formula. The obtained results are shown in Table 1.

  As is clear from the results shown in Table 1, in the permeability evaluation for various fragrance components at a temperature of 30 ° C. and a relative humidity of 0% using the PGA film of the present invention (Example 2), for all fragrance components. The film of the present invention showed good barrier properties. On the other hand, in the case of using a PET film (single-sided corona discharge treatment biaxial stretching) (Comparative Example 2), particularly large penetration of ethyl acetate was confirmed, and in the case of using an EVOH-F film (Comparative Example 4). The large permeation of ethyl acetate and 2-propanol was confirmed, and the barrier property against the aroma component was both greatly inferior to the film of the present invention.

<Aroma component permeability evaluation under conditions of temperature 30 ° C. and relative humidity 100%>
Similar to <Aroma component permeability evaluation under temperature 30 ° C. and relative humidity 0%>, except that a sponge wetted with water is placed on both upper and lower layers of each film and the relative humidity is 100%. By the method, the permeation | transmission quantity of the fragrance component which permeate | transmitted each film of Example 2, the comparative example 2, the comparative example 3, or the comparative example 4 was measured, and the transmittance | permeability of each film with respect to various fragrance components was computed. The obtained results are shown in Table 2.

  As is apparent from the results shown in Table 2, in the permeability evaluation for various fragrance components at a temperature of 30 ° C. and a relative humidity of 100% using the PGA film of the present invention (Example 2), for all fragrance components. The film of the present invention showed good barrier properties. On the other hand, in the case of using a PET film (single-sided corona discharge treatment biaxial stretching) (Comparative Example 2), large transmission of ethyl acetate was confirmed, and in the case of using an EVOH-F film (Comparative Example 4), Large permeation was confirmed in all fragrance components. In addition, regarding the NyMXD6 film (Comparative Example 3) that showed a good barrier property under the condition of 0% relative humidity, particularly large penetration of ethyl acetate and 2-propanol was confirmed under this condition. From this result, it was confirmed that the PGA film of the present invention has a sufficiently high barrier property against an aroma component, and is an aroma component barrier film excellent in aroma retention property even under a high humidity condition.

(Example 3)
The PGA resin composition obtained in Synthesis Example 1 was used as an intermediate layer resin, and polyethylene terephthalate (PET, “CB602S” manufactured by Totobo Co., Ltd., weight average molecular weight: 20,000, melt viscosity (temperature) 290 ° C., shear rate 122 sec ⁻¹ ): 550 Pa · s, glass transition temperature: 75 ° C., melting point: 249 ° C.), and a co-injection molding machine (manufactured by Cortec Co., Ltd.) capable of controlling the temperature for each barrel and runner for each layer. ) Was used to prepare a three-layer preform for bottles consisting of three layers of PET / PGA / PET (PGA filling amount: 3 mass%). At this time, the temperatures of the intermediate layer barrel and the runner were set to 235 ° C., and the temperatures of the inner and outer layer barrels and the runner were set to 290 ° C. The obtained three-layer preform for bottles was blow-molded at 110 ° C. using a stretch blow molding machine (manufactured by Frontier Co., Ltd.), and from three layers of PET / PGA / PET (PGA filling amount: 3 mass%). A 300 ml volume bottle (hereinafter referred to as “PET / PGA / PET bottle”) was obtained.

(Comparative Example 5)
Nylon MXD6 (Mitsubishi Engineering Plastics, trade name: Len 6007) is used as an intermediate layer resin, and polyethylene terephthalate (PET, Eastman Chemical Co., trade name: EASTAPAK 9921W) is used as an inner and outer layer resin. For bottles consisting of 3 layers of PET / NyMXD6 / PET (filling amount of NyMXD6: 3 mass%) using a co-injection molding machine (manufactured by Kretec, IN90) capable of temperature control for each barrel and runner for each layer A three-layer preform was prepared. At this time, the temperature of the barrel for the intermediate layer and the runner was set to 270 ° C., and the temperature of the barrel for the inner and outer layers and the runner was set to 280 ° C. The obtained three-layer preform for bottles was blow-molded at 92 ° C. using a stretch blow molding machine (trade name: SBO-2, manufactured by Sidel), and three layers of PET / NyMXD6 / PET (filling amount of NyMXD6: A bottle (hereinafter referred to as “PET / NyMXD6 / PET bottle”) having a volume of 300 ml consisting of 3% by mass) was obtained.

(Comparative Example 6)
Using an injection molding machine (manufactured by Coltech), polyethylene terephthalate (PET, “CB602S” manufactured by Totobo Co., Ltd., weight average molecular weight: 20,000, melt viscosity (temperature: 290 ° C., shear rate: 122 sec ⁻¹ ): 550 Pa · s , Glass transition temperature: 75 ° C., melting point: 249 ° C.), a polyethylene terephthalate single layer bottle preform was prepared. At this time, the injection temperature was set to 290 ° C. The obtained polyethylene terephthalate single-layer bottle preform was blow-molded at 100 ° C. using a stretch blow molding machine (manufactured by Frontier Co., Ltd.), and a bottle having a volume of 300 ml consisting only of polyethylene terephthalate (hereinafter “PET single-layer”). Bottle ").

<Evaluation of Perfume Component Permeability of Bottle under Temperature 30 ° C. and Relative Humidity 100% in Bottle>
To the PET / PGA / PET bottle obtained in Example 3, the PET / NyMXD6 / PET bottle obtained in Comparative Example 5 or the PET single-layer bottle obtained in Comparative Example 6, ethyl acetate (Wako Pure Chemical Industries, Ltd.) 10 ml of manufactured and special grade) and a test tube containing water were put, and an aluminum plate was attached to the mouth of each bottle with an adhesive and sealed. Each sealed bottle was placed in a 1270 ml glass bottle, covered, and stored at 30 ° C. Thereafter, the amount of ethyl acetate in the glass bottle is measured by GC / MS every day, and the value obtained by subtracting the measurement value on the measurement day from the measurement value on the next day is subtracted from the measurement value on the measurement day. The measurement date is regarded as the day when the steady state is entered, and the value obtained by subtracting the measurement value of the previous day from the measurement value on the measurement day is the amount of perfume component permeation in the steady state in the following equation. The value of The measurement method and the gas tight syringe cleaning after the measurement were performed in the same manner as in the above <Evaluation of aroma component permeability under temperature of 30 ° C.>. Based on the amount of ethyl acetate in the steady state, the transmittance of each bottle at 30 ° C. relative to ethyl acetate and 100% relative humidity inside the bottle was calculated based on the following formula.

Aroma component permeability = aroma component permeation amount (μg) / (bottle · time (day) · partial pressure difference (kPa)).

  In the formula, “fragrance component permeation amount (μg)” is the amount of ethyl acetate in the steady state, “time” is a unit time (1 day), and “partial pressure difference (kPa) ")" Is the difference between the vapor pressure of the aroma component inside the bottle and the vapor pressure of the aroma component outside. The obtained results are shown in Table 3.

  As is apparent from the results shown in Table 3, the container of the present invention showed good barrier properties in the permeability evaluation for ethyl acetate in the PET / PGA / PET bottle (Example 3) of the present invention. On the other hand, in the PET single-layer bottle (Comparative Example 6), a transmission as large as 100 times was confirmed as compared with the result in the container of the present invention. Also, the PET / NyMXD6 / PET bottle (Comparative Example 5) was inferior in terms of barrier properties against ethyl acetate under high humidity conditions as compared with the result of the container of the present invention. As a result, it was confirmed that the aroma component barrier container of the present invention was excellent in aroma retention even under high humidity conditions.

  As described above, according to the present invention, by using the polyglycolic acid resin, the barrier property against the fragrance component is sufficiently high, and the fragrance component barrier film excellent in the fragrance retention property even under a high humidity condition. In addition, it is possible to provide an aroma component barrier multilayer film, an aroma component barrier container, and a method for improving an aroma component barrier property using the same.

  In addition, it has been clear from the past that polyglycolic acid-based resins have high transparency, high strength, excellent moldability, and high biodegradability, and are also excellent packaging materials from the viewpoint of waste treatment. It is.

  Therefore, the fragrance component barrier film of the present invention is useful as a container for storing or transporting foods, beverages, cosmetics, bathing agents and the like. In particular, the aroma component barrier film of the present invention is excellent in barrier properties against aroma components and ethyl acetate contained in a large amount of fruit juice and the like, and does not lower the barrier property even under high humidity conditions. It is also useful in the provision of a storage container or a method for improving the aroma component barrier property of a paper or polyethylene terephthalate (PET) container used for the beverage or the like.

  DESCRIPTION OF SYMBOLS 1 ... Measurement cell, 1a ... Measurement cell (upper layer), 1b ... Measurement cell (lower layer), 2 ... Aroma component, 3 ... Dry air, 4 ... Film, 5 ... Constant temperature bath, 6 ... Gas tight syringe.

Claims (6)

  An aromatic component barrier film comprising a polyglycolic acid resin. Permeability component permeability at 30 ° C. and 0% relative humidity with respect to ethyl acetate, cyclohexane and 2-propanol as aroma components is less than 1.0 (μg · 10 μm) / (m ² · day · kPa), respectively. The fragrance component barrier film according to claim 1. Permeability component permeability at 30 ° C. and 100% relative humidity with respect to ethyl acetate, cyclohexane and 2-propanol as aroma components is less than 1.0 (μg · 10 μm) / (m ² · day · kPa), respectively. The fragrance component barrier film according to claim 1 or 2.   An aroma component barrier multilayer film comprising the aroma component barrier film according to any one of claims 1 to 3.   An aroma component barrier container characterized by being formed by molding the aroma component barrier multilayer film according to claim 4.   The fragrance component barrier property improving method using the fragrance component barrier property film according to any one of claims 1 to 3.