JP2009179400A - Biodegradable blister pack - Google Patents

Abstract

[PROBLEMS] To improve the production efficiency by omitting the adhesive application process, eliminate the need for disposal, have no negative impact on the environment when incinerated or landfilled, and can escape from depleted petroleum resources. The purpose is to provide a blister pack.
A recess is formed for accommodating an article Rutotomoni, a cover member recess perimeter is formed in the periphery of the recess, the blister pack comprising a sheet substrate for closing the concave portion, the cover material and the seat base are both formed of a resin composed mainly of polylactic acid polymer, the sheet substrate is made up of a multilayer structure consisting of crystalline different at least two layers, first of the laminate The relationship between the content ratio of D-lactic acid in the polylactic acid polymer constituting one layer and the content ratio of D-lactic acid in the polylactic acid polymer constituting the second layer of the laminate satisfies a predetermined requirement, The 2nd layer which comprises a laminated body is arrange | positioned in the surface which contact | connects a cover material, and the recessed part peripheral part of the cover material and the sheet | seat base material were thermocompression-bonded, It is characterized by the above-mentioned.
[Selection figure] None

Description

The present invention relates to a blister pack having biodegradability.

  Blister packs are widely used to wrap, display and sell products such as dry batteries and toothbrushes. This blister pack is usually composed of a cover material in which a recess for storing an article is formed and a sheet base material formed of cardboard or the like for closing the recess after storing the article.

  This blister pack can substantially seal the contents, while the cover material in which the recesses are formed can be made transparent, so that the contents can be visually recognized, and is excellent as a packaging container.

  As a method of attaching the cover material and the sheet base material, 1) a method of fastening both peripheral portions with staples. 2) A method in which the ends of two opposite sides of the cover material are bent into a “U” shape, and the sheet base material is slid and attached to the groove. 3) There is a method of bonding the cover material and the sheet base material by thermocompression bonding with an adhesive in the vicinity of the recess for storing the article. Recently, a method 3) of thermocompression bonding using an adhesive is widely employed because mass production by blister automatic packaging is possible and the appearance is excellent.

  However, in the method of bonding using a conventional adhesive, the cover material formed with a large number of recesses and the large sheet base material are bonded, and then divided into individual blister packs by punching or the like. There has been a problem that the cover material and the sheet base material are not uniformly bonded due to variations in pressure and temperature during bonding, uneven thickness, and the like. Moreover, in order to adhere | attach a cover material and a sheet | seat base material side, the process of apply | coating an adhesive agent to a sheet | seat base material side is required, and there also existed a problem in terms of production efficiency.

  In addition, the sheet base material is usually formed of paper, but there is a problem with water resistance from the viewpoint of content protection, and when the product is taken out from the blister pack and discarded as garbage, the cover material and paper It was necessary to separate and discard the sheet base material.

  In order to solve these problems, recently, an example in which the same plastic material is used for the cover material and the sheet base material is known. For example, the cover material and the sheet base material are made of PET (polyethylene terephthalate) and are made into a blister pack through an adhesive.

  In this case, the cover material and the sheet base material are certainly the same material, so that it is not necessary to separate and dispose of them, and it is water resistant unlike paper. Furthermore, the problem of the conventional cover material polyvinyl chloride does not occur.

  However, in general, blister packs are disposable, and when PET is disposed of in landfills after use, the chemical stability is high, so that it hardly remains decomposed in the natural environment and remains semi-permanently in the soil. Saturate the capacity of the land for garbage disposal in a short period of time. Moreover, if it is dumped into the natural environment, it will damage the landscape and destroy the living environment such as marine life. Furthermore, the starting material for PET is oil, and we cannot expect to escape from the depleted petroleum resources that have become a problem in recent years.

  Therefore, the present invention improves the production efficiency by omitting the adhesive application process, does not require time and effort for disposal, and does not adversely affect the environment when incinerated or landfilled. The purpose is to provide a blister pack that can be used.

The present invention relates to a blister pack comprising a cover material in which a recess for storing an article is formed and a sheet base material for closing the recess, both of the cover material and the sheet base material being polylactic acid It is composed of a resin mainly composed of a polymer, and at least one of the sheet base material or the cover material is composed of a laminate composed of at least two layers having different crystallinity, and constitutes the first layer of this laminate The relationship between the D-lactic acid content ratio Da (%) of the polylactic acid polymer and the D-lactic acid content ratio Db (%) of the polylactic acid polymer constituting the second layer of the laminate, While satisfy | filling following formula (1), the said 2nd layer comprises at least one outermost layer of the said laminated body,
Da ≦ 7 and Db−Da> 3 (1)
The biodegradable blister pack characterized in that the second layer constituting the laminate is disposed on a surface in contact with the cover material or the sheet base material combined with the sheet base material or cover material comprising the laminate. The above-mentioned problem has been solved by using.

  Since both the sheet base material and the cover material use a resin mainly composed of a plant-derived biodegradable polylactic acid polymer, there is no need for disposal, and it is environmentally friendly when incinerated or landfilled. It is possible to escape from the depleted petroleum resources without adversely affecting them.

  In addition, since a predetermined material is used as at least one of the surfaces of the sheet base material and the cover material that come into contact with each other, thermocompression bonding is possible, the adhesive application step can be omitted, and the production efficiency is improved. be able to.

  Since the cover material and the sheet base material constituting the blister pack according to the present invention have a layer configuration having a specific composition, the step of applying an adhesive to the sheet base material is omitted, and the cover material and the sheet base material are also included. Can be adhered uniformly and firmly, and the adhesion of the ink is good when printed for the purpose of improving the design. Furthermore, they are difficult to peel off during the printing distribution process, and the cover material and the sheet base material are sorted. Further, it is possible to provide a blister pack that can be disposed of as waste and that does not adversely affect the environment even when incinerated or landfilled, and that can escape from exhausted petroleum resources.

The present invention will be described in detail below.
The blister pack according to the present invention is composed of a cover material in which a recess for storing an article is formed and a sheet base material for closing the recess. The cover material and the sheet base material are both made of a resin mainly composed of a polylactic acid polymer.

  The polylactic acid-based polymer refers to a polymer obtained by condensation polymerization of a monomer mainly composed of lactic acid. This lactic acid includes two types of optical isomers, L-lactic acid and D-lactic acid, and the crystallinity differs depending on the proportion of these two types of structural units. For example, a random copolymer having a ratio of L-lactic acid to D-lactic acid of about 80:20 to 20:80 is a transparent completely non-crystalline polymer that has no crystallinity and softens near a glass transition point of 60 ° C.

  On the other hand, a random copolymer having a ratio of L-lactic acid to D-lactic acid of approximately 100: 0 to 80:20 or 20:80 to 0: 100 has crystallinity. The crystallinity is determined by the ratio of L-lactic acid and D-lactic acid, and the glass transition point of this copolymer is a polymer of about 60 ° C. as described above. This polymer becomes an amorphous material with excellent transparency by being rapidly cooled after melt extrusion, and becomes a crystalline material by slowly cooling. For example, a homopolymer composed of only L-lactic acid or only D-lactic acid is a semicrystalline polymer having a melting point of 180 ° C. or higher.

  The polylactic acid polymer used in the present invention is a homopolymer having a structural unit of L-lactic acid or D-lactic acid, that is, poly (L-lactic acid) or poly (D-lactic acid), and the structural unit is L-lactic acid. And a copolymer that is both D-lactic acid, that is, poly (DL-lactic acid) and a mixture thereof, and further, a copolymer with other hydroxycarboxylic acid and diol / dicarboxylic acid as a copolymerization component It may be. It may also contain a small amount of chain extender residues.

  As a polymerization method of the polylactic acid polymer, known methods such as a condensation polymerization method and a ring-opening polymerization method can be employed. For example, in the condensation polymerization method, L-lactic acid, D-lactic acid or a mixture thereof can be directly dehydrated and condensation polymerized to obtain a polylactic acid polymer having an arbitrary composition.

  In the ring-opening polymerization method (lactide method), a lactate which is a cyclic dimer of lactic acid is used to obtain a polylactic acid polymer using a selected catalyst while using a polymerization regulator or the like as necessary. be able to.

  Examples of the other hydroxycarboxylic acid units constituting the polylactic acid polymer include optical isomers of lactic acid (D-lactic acid for L-lactic acid, L-lactic acid for D-lactic acid), glycol Acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaproic acid And lactones such as caprolactone, butyrolactone and valerolactone.

  Examples of the aliphatic diol constituting the polylactic acid polymer include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol and the like. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid.

  If necessary, a non-aliphatic diol such as a non-aliphatic dicarboxylic acid such as terephthalic acid and / or an ethylene oxide adduct of bisphenol A may be used as a small amount copolymerization component.

  The preferred range of the weight average molecular weight of the polylactic acid polymer used in the present invention is 60,000 to 700,000, more preferably 80,000 to 400,000, and particularly preferably 100,000 to 300,000. If the molecular weight is too small, practical physical properties such as mechanical properties and heat resistance are hardly expressed, and if it is too large, the melt viscosity is too high and the molding processability is poor.

  Further, for the purpose of improving flexibility and various processability in the blister pack of the present invention, a biodegradable aliphatic polyester other than the polylactic acid resin is used in the range that does not impair the practical characteristics of the polylactic acid polymer. May be added.

  Examples of the biodegradable aliphatic polyester include polyhydroxycarboxylic acid, aliphatic diol and aliphatic dicarboxylic acid, or aliphatic polyester obtained by condensation of aliphatic diol, aliphatic dicarboxylic acid and aromatic dicarboxylic acid, Or aliphatic aromatic polyester, aliphatic polyester copolymer obtained from aliphatic diol and aliphatic dicarboxylic acid, and hydroxycarboxylic acid, aliphatic polyester obtained by ring-opening polymerization of cyclic lactones, synthetic aliphatic polyester, bacterial cells Aliphatic polyesters biosynthesized by the above method.

  Examples of the polyhydroxycarboxylic acid include 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, and 2-methyl. Examples thereof include homopolymers and copolymers of hydroxycarboxylic acids such as lactic acid and 2-hydroxycaproic acid.

  Examples of the aliphatic diol include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol and the like. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid and the like.

  Examples of the aromatic dicarboxylic acid include terephthalic acid and isophthalic acid. Aliphatic polyesters obtained by condensing these aliphatic diols and aliphatic dicarboxylic acids, and aliphatic aromatic polyesters obtained by condensing aliphatic diols, aliphatic dicarboxylic acids and aromatic dicarboxylic acids, One or more compounds can be selected from each of the compounds and subjected to condensation polymerization, and further, if necessary, jumped up with an isocyanate compound or the like to obtain a desired polymer.

  Examples of the aliphatic diol and the aliphatic carboxylic acid used in the aliphatic polyester copolymer obtained from the aliphatic diol, the aliphatic dicarboxylic acid, and the hydroxycarboxylic acid are the same as those described above. For acids, L-lactic acid, D-lactic acid, D, L-lactic acid, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2- Examples thereof include hydroxy 3-methylbutyric acid, 2-methyl lactic acid, 2-hydroxycaproic acid and the like, such as polybutylene succinate lactic acid and polybutylene succinate adipate lactic acid.

  However, the composition ratio in this case is mainly an aliphatic diol and an aliphatic dicarboxylic acid, and the existence ratio is 35 to 49.99 mol% of aliphatic diol and 35 to 49.99 mol of aliphatic dicarboxylic acid. %, And hydroxycarboxylic acid is 0.02 to 30 mol%.

  The aliphatic polyester obtained by ring-opening polymerization of the cyclic lactone is obtained by polymerizing one or more of ε-caprolactone, δ-valerolactone, β-methyl-δ-valerolactone and the like as a cyclic monomer. .

  Examples of the synthetic aliphatic polyester include copolymers of cyclic acid anhydrides and oxiranes such as succinic anhydride and ethylene oxide, propylene oxide.

  Examples of the aliphatic polyester biosynthesized in the microbial cells include aliphatic polyesters biosynthesized by acetylcoenteam A (acetyl CoA) in the microbial cells including Alkaline genus eutrophus. The aliphatic polyester biosynthesized in the cells is mainly poly-β-hydroxybutyric acid (poly-3HB), but is copolymerized with hydroxyvaleric acid (HV) to improve the practical properties of plastics. It is industrially advantageous to make a copolymer of poly (3HB-CO-3HV). The HV copolymerization ratio is generally preferably 0 to 40 mol%. Furthermore, instead of hydroxyvaleric acid, a long-chain hydroxyalkanoate such as 3-hydroxyhexanoate, 3-hydroxyoctanoate, and 3-hydroxyoctadecanoate may be copolymerized.

  At least one of the cover material and the sheet base material constituting the blister pack according to the present invention is composed of a laminate composed of at least two layers having different crystallinity. The first layer in the laminate (hereinafter simply referred to as “first layer”) is composed of a resin mainly composed of a polylactic acid polymer, and is preferably crystalline. The second layer of the laminate (hereinafter simply referred to as “second layer”) is composed of a polylactic acid polymer as a main component. And this 2nd layer is distribute | arranged to the at least one outermost layer of the said laminated body.

  Moreover, the 2nd layer which comprises the said laminated body is arrange | positioned in the surface which touches the cover material or sheet base material combined with the sheet base material or cover material which consists of the said laminated body which has a 2nd layer. That is, when the laminate having the second layer forms a sheet substrate, the second layer of the laminate constituting the sheet substrate is disposed on the surface in contact with the cover material, or the second layer When the laminated body having a layer forms a cover material, the second layer of the laminated body constituting the cover material is disposed on the surface in contact with the sheet base material. This is because the sheet base material and the cover material are thermally fused as will be described later.

The D-lactic acid content (hereinafter referred to as “Da”) (%) in the crystalline polylactic acid polymer constituting the first layer and the D-lactic acid polymer D- constituting the second layer. The content ratio of lactic acid (hereinafter referred to as “Db”) (%) preferably satisfies the following formula (1).
Da ≦ 7 and Db−Da> 3 (1)

  Since the first layer has crystallinity, it becomes a support layer. The ratio (Da) of D-lactic acid in the crystalline polylactic acid polymer constituting the first layer is preferably 7% or less, and more preferably 5% or less. If it exceeds 7%, the degree of crystallinity as a support layer is low, heat resistance cannot be obtained, and it tends to shrink and deform when heated.

  Since the second layer has amorphous or semi-crystalline properties, it can be easily melted by heat and becomes a thermocompression bonding layer. The proportion (Db) of D-lactic acid in the polylactic acid polymer constituting the second layer is preferably higher than 3% than Da. When this difference is 3% or less, both the crystallinity and the melting point are close to the polylactic acid polymer constituting the first layer, and it is necessary to perform thermocompression bonding at a high temperature. That is, in the high temperature thermocompression bonding, the support layer is also heated and heat shrinkage occurs, which causes a problem of generating undulations, wrinkles and the like in the product. Therefore, in order to lower the crystallinity and the melting point as compared with the support layer, it is preferable to set in the range of the formula (1).

  In the said blister pack, in order to raise the designability, a printing layer can be provided in the single side | surface or both surfaces of a sheet | seat base material. When printing on the side of the sheet base material that comes into contact with the cover material, if there is a print layer up to the part where both are thermocompression bonded, the sheet base material and the cover material have thermocompression bonding because the print layer is interposed. do not do. Therefore, in this case, it is necessary to configure the sheet base material with a plurality of base materials. That is, the sheet base material is preferably composed of at least two types of base materials A and B.

  As the base material A and the base material B, a laminate composed of at least two layers having different crystallinities as described above can be used. That is, the base material A and the base material B have the first layer and the second layer, and the relationship between Da (%) of the first layer and Db (%) of the second layer is expressed by the formula ( It is good to satisfy 1).

  In any of the laminates constituting the base material A and the base material B, at least one outermost layer is preferably composed of the second layer. And a printing layer is provided on the 2nd layer of the said base material A, the 2nd layer side of the base material B is arrange | positioned in the surface which touches the said cover material, the printing layer side of the base material A, and the base material B Are preferably integrated by lamination. Since the second layer has an effect of strengthening the adhesion of the printing ink in addition to the thermocompression bonding property, the integration is possible.

  At this time, Da is preferably 7% or less, and more preferably 5% or less. If it exceeds 7%, the degree of crystallinity as a support layer is low, heat resistance cannot be obtained, and when heated during printing, laminating, or thermocompression bonding, it tends to shrink and deform. In addition, when a printing layer is provided on the first layer, the ink adhesion may be insufficient.

  The laminating method can be performed by a known method or apparatus such as a dry laminating method or a wet laminating method.

  As another means, the sheet base material is composed of at least two types of base materials A and B, and the base material B is composed of at least two types of resin layers having different crystallinity. And a method using a laminate comprising at least three layers.

  Examples of the at least two types of resin layers constituting the substrate B include the first layer and the second layer described above. The relationship between Da (%) of the first layer and Db (%) of the second layer satisfies the formula (1). The second layer constitutes both outermost layers of the base material B.

  One of the outermost layers constituting the base material B is disposed on a surface in contact with the cover material side. The other outermost layer is provided with a printing layer on the surface thereof. The base material A is laminated on the outermost layer provided with the print layer, and the base material A and the base material B are integrated. The second layer constituting the outermost layer has the effect of strengthening the adhesiveness of the printing ink in addition to the thermocompression bonding property, so that the integration is possible.

  The laminating method can be performed by a known method or apparatus such as a dry laminating method or a wet laminating method.

  The crystalline polylactic acid polymer constituting the first layer and the non-crystalline or semicrystalline polylactic acid polymer constituting the second layer are two or more different polylactic acid polymers. It may be. In this case, Da and Db are average values calculated from the blending ratio of D-lactic acid constituting two or more types of polylactic acid polymers.

Since the second layer has thermocompression bonding property and ink adhesion, it is preferable to constitute at least one outermost layer of the laminate.
Therefore, the laminated body may have a two-layer structure of first layer / second layer or a three-layer structure of second layer / first layer / second layer. Furthermore, a multi-layer configuration of first layer / second layer / first layer... / Second layer or second layer / first layer / second layer.

  The thickness of the 2nd layer which comprises the outermost layer of these laminated bodies is 2 micrometers or more, Preferably it is 5 micrometers or more, and when it is less than that, desired thermocompression bonding property and ink adhesiveness may not be obtained.

  Furthermore, a recycled resin layer or an intermediate layer between the first layer and the second layer may be laminated between the first layer and the second layer as long as the effects of the present invention are not impaired.

  Furthermore, a secondary additive can be added to the laminate of the present invention to perform various modifications. Examples of secondary additives include stabilizers, antioxidants, UV absorbers, pigments, electrostatic agents, conductive agents, mold release agents, plasticizers, fragrances, antibacterial agents, nucleating agents, and other similar ones. can give.

  The method for laminating the laminate of the present invention is not particularly limited as long as the object of the present invention is not impaired. For example, (1) using two or three or more extruders and a multi-manifold or feed block type die. Co-extrusion method that laminates and extrudes as a molten sheet, (2) a method of coating the other resin on one of the unrolled layers, and (3) thermocompression bonding each layer at an appropriate temperature using a roll or a press A method, or (4) a method of bonding using an adhesive, and the like.

  Moreover, as a method of imparting heat resistance to the polylactic acid polymer constituting the first layer of the laminate, (1) a method of slowly cooling the melted laminate, (2) a method of annealing the laminate, (3) A method of performing heat treatment after stretching the laminate biaxially can be mentioned, but the method (3), which can be expected to improve impact resistance by molecular orientation, provides a more practical laminate. preferable.

  As a method for producing a biaxially stretched laminate comprising a polylactic acid-based polymer as a main component, a sheet-like product or a cylindrical product extruded from a T-die, I-die, round die, etc. is cooled by a cast roll, water, compressed air, etc. Examples include a method of rapidly cooling and solidifying in a state close to an amorphous state, and then stretching biaxially by a roll method, a tenter method, a tubular method, or the like.

  Usually, in the production of a biaxially stretched laminate, a sequential biaxial stretching method in which longitudinal stretching is performed by a roll method and a lateral stretching is performed by a tenter method, and a simultaneous biaxial stretching method in which a longitudinal and lateral stretching is performed simultaneously by a tenter are generally used.

  As stretching conditions, a stretching temperature of 55 to 90 ° C., preferably 65 to 80 ° C., a longitudinal stretching ratio of 1.5 times, preferably 2 to 4 times, a transverse stretching ratio of 1.5 to 5 times, preferably 2 to 4 times. The stretching speed is 10 to 100000% / min, preferably 100 to 10000% / min. However, these suitable ranges vary depending on the composition of the polymer and the thermal history of the unstretched sheet, and therefore can be appropriately determined in consideration of the strength and elongation of the laminate.

  When it is not within the range of the draw ratio and the drawing temperature, the thickness accuracy of the obtained laminate is significantly lowered, and this tendency is particularly remarkable in a laminate to be heat-treated after stretching. Such thickness fluctuations can cause the appearance of wrinkles, undulations, etc., in products such as printing on laminates, lamination with other films, metal thin films, paper, and secondary processing such as thermocompression bonding. It becomes a factor that ends up.

  This biaxially stretched laminate can be used as it is as the sheet substrate, and can also be used as a cover material by blistering the biaxially stretched laminate.

  Since the laminate has thermocompression bonding and ink adhesion, the article is stored in the cover material obtained by the above-described method, and then the cover material and the sheet base material are closed by thermocompression bonding. A biodegradable blister pack containing the above is obtained.

  Examples of the article include batteries, electric appliances, daily necessities, toys, stationery, miscellaneous goods, cosmetics, medicines, medical instruments, accessories, and the like.

The present invention will be described more specifically with reference to the following examples and comparative examples.
Examples are shown below, but the present invention is not limited by these examples. In addition, the physical-property value in an Example and a comparative example was measured and evaluated with the following method.

[Stretch ratio]
The draw ratio in the machine direction was calculated from the following formula.
・ Longitudinal stretch ratio = flow rate of laminate after longitudinal stretching / flow rate of original sheet before longitudinal stretching The stretching ratio in the horizontal direction is the width of the portion gripped by the tenter clip from the width of the original sheet before longitudinal stretching. The value obtained by subtracting the length obtained by subtracting the width of the portion gripped by the clip from the width obtained after transverse stretching was calculated from the following equation.
・ Horizontal stretch ratio = {(Laminated body width after stretching) − (Width held by clip)} / {(Original sheet width before stretching) − (Width held by clip)}

[Seal strength]
Prepare a cover material and a sheet base material having recesses, store the cover material recesses in a mold having a concave mold, and superimpose the sheet base material on the cover material, so that the periphery of the concave portion of the cover material and the sheet base material Thermocompression bonding was performed. Thereafter, a sample having a width of 15 mm was cut out from the peripheral portion of the recessed portion subjected to thermocompression bonding and used for measuring the seal strength. The sealing conditions were 150, 160, 170 ° C. × 5 seconds, and the pressure was 1.5 kg / cm ² . The seal strength was measured by the method described in JISZ1711.
Moreover, the following criteria evaluated.
○: Seal strength 0.7 kgf / 15 mm or more ×: Seal strength less than 0.7 kgf / 15 mm Note that samples with poor finish have relatively poor seal strength and tend to vary. Therefore, it was described that measurement was impossible because the appearance was remarkably bad.

[Seal appearance]
At the time of the seal strength test, it was visually observed at each temperature (150, 160, 170 ° C.) to examine the presence or absence of wrinkles, undulations, unevenness, etc., and markedly marked “X”. On the other hand, although some of these were observed, those with a practically sufficient finished state were marked as “◯”.

[Ink adhesion]
A UV curable ink was applied to the sheet substrate, the ink was cured with a UV lamp, and then allowed to stand at room temperature for 24 hours. Thereafter, a 10 mm wide crosscut was put into the sample, the pressure-sensitive adhesive side of the cloth tape was pressed against the printing surface, the cloth tape was peeled off, and the presence or absence of ink removal was confirmed. Samples with ink taken on the adhesive side were marked with x, and samples without ink were marked with ◯.

[Comprehensive evaluation]
In the evaluation of the sealing strength, appearance, and ink adhesion (only printed samples), all the samples with “◯” are indicated as “◯”, and those with at least one “X” are indicated as “X”.

(Structure of the resin of the laminate)
As resin which comprises a laminated body, the 1st component independent shown in Table 1 or the mixture of the 1st component and the 2nd component was used. The D-lactic acid ratio in the case of the mixture was calculated as an average value from the weight fraction of both.

(Sheet base material)
Each of the sheet substrates was produced by the following method. In addition, Da, Db, etc. of the base materials A-1 to A-7 and B-1 to B-3 are collectively shown in Table 2.

[Substrate A-1]
L-lactic acid: D-lactic acid = 80: 20 structural unit, glass transition point (Tg) 52 ° C. polylactic acid 80%, L-lactic acid: D-lactic acid = 95: 5 structural unit, glass transition Point (Tg) Granular silica having an average particle size of 1.4 μm mixed with 20% polylactic acid at 56 ° C. and dried to a total of 100 parts by weight of polylactic acid (Db = 17%, resin 5 in Table 1): 1 part by weight and 9 parts by weight of anatase-type titanium oxide were mixed and extruded as a front and back layer from a multi-manifold die at 220 ° C. with a 25 mmφ co-directional twin screw extruder.

  Further, a polylactic acid polymer having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. (resin 1 in Table 1) And 9 parts by weight of anatase-type titanium oxide were mixed and extruded as an intermediate layer from the die using a 40 mmφ single screw extruder.

  The discharge amount of the molten resin was adjusted so that the thickness ratio of the surface layer, the intermediate layer, and the back layer was 1: 10: 1. This coextruded sheet was quenched with a casting roll at about 43 ° C. to obtain an unstretched sheet. Subsequently, the film was stretched 2.6 times at 76 ° C. in the longitudinal direction, and then stretched 3.2 times at a temperature of 72 ° C. with a tenter in the width direction. The temperature of the heat treatment zone in the tenter was 130 ° C., and a heat treated laminate was produced. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the thickness of the laminate was approximately 100 μm on average.

[Substrate A-2, A-3]
As shown in Table 2, a polylactic acid-based polymer (corresponding to each resin described in Table 1) having different L-lactic acid and D-lactic acid was used as [Substrate A-1], respectively. A laminate was obtained by extruding to a predetermined thickness ratio as a layer and a back layer, and biaxially stretching and heat-treating.

[Substrate A-4]
Biodegradable aliphatic polyester (Showa Polymer Bionore 3003 melting point: 95 ° C., glass transition point: −40 ° C.) is mixed in the intermediate layer so that polylactic acid / biodegradable aliphatic polyester = 80/20% by weight. A laminate was obtained in the same manner as [Substrate A-1] except that.

[Substrate A-5]
L-lactic acid: D-lactic acid = 80: 20 structural unit, glass transition point (Tg) 52 ° C. polylactic acid 80%, L-lactic acid: D-lactic acid = 95: 5 structural unit, glass transition Point (Tg) Granular silica having an average particle size of 1.4 μm mixed with 20% polylactic acid at 56 ° C. and dried to a total of 100 parts by weight of polylactic acid (Db = 17%, resin 5 in Table 1): 1 part by weight and 9 parts by weight of anatase-type titanium oxide were mixed and extruded at 210 ° C. as a surface layer from a two-layer multi-manifold die using a 25 mmφ co-directional twin screw extruder.

  Further, a polylactic acid polymer having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. (resin 1 in Table 1) ) Dried silica particles having an average particle size of 1.4 μm: 0.1 parts by weight and 9 parts by weight of anatase-type titanium oxide were mixed and extruded as an intermediate layer from the die at 210 ° C. with a 40 mmφ single-screw extruder. did. Since the obtained laminate has a two-layer structure, the intermediate layer forms the back layer as it is.

  The amount of molten resin discharged was adjusted so that the thickness ratio of the laminate was 1: 9 in the surface layer: intermediate layer. This coextruded sheet was quenched with a casting roll at about 42 ° C. to obtain an unstretched sheet. Subsequently, the film was stretched 2.6 times at 76 ° C. in the longitudinal direction, and then stretched 3.2 times at a temperature of 74 ° C. with a tenter in the width direction. The temperature of the heat treatment zone in the tenter was set to 135 ° C. to produce a heat treated laminate. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the thickness of the laminate was approximately 100 μm on average.

[Substrate A-6]
L-lactic acid: D-lactic acid = 80: 20 structural unit, glass transition point (Tg) 52 ° C. polylactic acid 80%, L-lactic acid: D-lactic acid = 95: 5 structural unit, glass transition Point (Tg) Mixing 20% polylactic acid at 56 ° C., 100 parts by weight of polylactic acid (Db = 17%, resin 5 in Table 1), biodegradable aliphatic polyester 1001 melting point: 115 ° C., glass transition point: −40 ° C.) was mixed so that polylactic acid / biodegradable aliphatic polyester = 60/40% by weight, and further dried, granular silica having an average particle size of 1.4 μm: 0.1 parts by weight of the mixture and 9 parts by weight of anatase-type titanium oxide were mixed and extruded at 210 ° C. as a surface layer from a two-layer multi-manifold die using a 25 mmφ co-directional twin screw extruder.

  Further, a polylactic acid polymer having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. (resin 1 in Table 1) ) Dried silica particles having an average particle size of 1.4 μm: 0.1 parts by weight and 9 parts by weight of anatase-type titanium oxide were mixed and extruded as an intermediate layer from the die at 210 ° C. with a 40 mmφ single-screw extruder. did. Since the obtained laminate has a two-layer structure, the intermediate layer forms the back layer as it is.

  The amount of molten resin discharged was adjusted so that the thickness ratio of the laminate was 1: 9 in the surface layer: intermediate layer. The coextruded sheet was brought into contact with a casting roll at about 100 ° C. to obtain an unstretched laminate. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the thickness of the laminate was approximately 100 μm on average.

[Base Material A-7]
A polylactic acid polymer (resin 1 in Table 1) having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. Dry silica particles with an average particle size of 1.4 μm: 0.1 parts by weight and 9 parts by weight of anatase-type titanium oxide were mixed and extruded at 210 ° C. from a single-layer die using a 40 mmφ co-directional twin-screw extruder. did. This extruded sheet was quenched with a casting roll at about 42 ° C. to obtain an unstretched sheet. Subsequently, the film was stretched 2.6 times at 76 ° C. in the longitudinal direction, and then stretched 3.2 times at a temperature of 74 ° C. with a tenter in the width direction. The temperature of the heat treatment zone in the tenter was set to 135 ° C. to produce a heat treated sheet. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the sheet thickness was approximately 100 μm on average.

[Substrate B-1]
L-lactic acid: D-lactic acid = 80: 20 structural unit, glass transition point (Tg) 52 ° C. polylactic acid 80%, L-lactic acid: D-lactic acid = 95: 5 structural unit, glass transition Point (Tg) Granular silica having an average particle size of 1.4 μm mixed with 20% polylactic acid at 56 ° C. and dried to a total of 100 parts by weight of polylactic acid (Db = 17%, resin 5 in Table 1): 1 part by weight was mixed and extruded as a front and back layer from a multi-manifold die at 220 ° C. with a 25 mmφ same-direction twin screw extruder.

  Further, a polylactic acid polymer having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. (resin 1 in Table 1) ) Was extruded as an intermediate layer from the die using a 40 mmφ single screw extruder.

  The discharge amount of the molten resin was adjusted so that the thickness ratio of the surface layer, the intermediate layer, and the back layer was 1: 3: 1. This coextruded sheet was quenched with a casting roll at about 43 ° C. to obtain an unstretched sheet. Subsequently, the film was stretched 2.6 times at 76 ° C. in the longitudinal direction, and then stretched 3.2 times at a temperature of 72 ° C. with a tenter in the width direction. The temperature of the heat treatment zone in the tenter was 130 ° C., and a heat treated laminate was produced. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the thickness of the laminate was approximately 50 μm on average.

[Substrate B-2]
As shown in Table 2, a polylactic acid-based polymer (corresponding to each resin described in Table 1) of L-lactic acid and D-lactic acid, respectively, as in [Substrate B-1], surface layer, intermediate A laminate was obtained by extruding to a predetermined thickness ratio as a layer and a back layer, and biaxially stretching and heat-treating.

[Substrate B-3]
L-lactic acid: D-lactic acid = 80: 20 structural unit, glass transition point (Tg) 52 ° C. polylactic acid 80%, L-lactic acid: D-lactic acid = 95: 5 structural unit, glass transition Point (Tg) Granular silica having an average particle size of 1.4 μm mixed with 20% polylactic acid at 56 ° C. and dried to a total of 100 parts by weight of polylactic acid (Db = 17%, resin 5 in Table 1): 1 part by weight was mixed and extruded at 210 ° C. as a surface layer from a two-layer multi-manifold die using a 25 mmφ co-directional twin screw extruder.

  Further, a polylactic acid polymer having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. (resin 1 in Table 1) ) Dried granular silica having an average particle size of 1.4 μm: 0.1 part by weight was mixed and extruded as an intermediate layer from the die at 210 ° C. with a 40 mmφ single screw extruder. Since the obtained laminate has a two-layer structure, the intermediate layer forms the back layer as it is.

  The amount of molten resin discharged was adjusted so that the thickness ratio of the laminate was 1: 4 in the surface layer: intermediate layer. This coextruded sheet was quenched with a casting roll at about 42 ° C. to obtain an unstretched sheet. Subsequently, the film was stretched 2.6 times at 76 ° C. in the longitudinal direction, and then stretched 3.2 times at a temperature of 74 ° C. with a tenter in the width direction. The temperature of the heat treatment zone in the tenter was set to 135 ° C. to produce a heat treated laminate. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the thickness of the laminate was approximately 50 μm on average.

(Cover material)
Each of the cover materials was produced by the following method. Note that Da, Db, and the like of the cover materials 1 to 3 are collectively shown in Table 3.

[Cover Material 1]
A polylactic acid polymer (resin 1 in Table 1) having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. Dry granular silica having an average particle size of 1.4 μm: 0.1 part by weight was mixed and extruded at 210 ° C. from a single-layer die using a 40 mmφ co-directional twin screw extruder. This extruded sheet was quenched with a casting roll at about 42 ° C. to obtain an unstretched sheet. Subsequently, the film was stretched 2.6 times at 76 ° C. in the longitudinal direction, and then stretched 3.2 times at a temperature of 74 ° C. with a tenter in the width direction. The temperature of the heat treatment zone in the tenter was set to 135 ° C. to produce a heat treated sheet. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the sheet thickness was approximately 250 μm on average.
Next, using the obtained sheet, concave-shaped molding was performed. That is, using a molding die (mold temperature 25 ° C.), pressure air molding was performed under the conditions of a sheet temperature 140 ° C. and a pressure: 6 kg / cm ² to obtain a cover material having a recess.

[Cover material 2]
L-lactic acid: D-lactic acid = 80: 20 structural unit, glass transition point (Tg) 52 ° C. polylactic acid 80%, L-lactic acid: D-lactic acid = 95: 5 structural unit, glass transition Point (Tg) Granular silica having an average particle size of 1.4 μm mixed with 20% polylactic acid at 56 ° C. and dried to a total of 100 parts by weight of polylactic acid (Db = 17%, resin 5 in Table 1): 1 part by weight was mixed and extruded at 210 ° C. as a surface layer from a two-layer multi-manifold die using a 25 mmφ co-directional twin screw extruder.

  Further, a polylactic acid polymer having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. (resin 1 in Table 1) ) Dried granular silica having an average particle size of 1.4 μm: 0.1 part by weight was mixed and extruded as an intermediate layer from the die at 210 ° C. with a 40 mmφ single screw extruder. Since the obtained laminate has a two-layer structure, the intermediate layer forms the back layer as it is.

  The amount of molten resin discharged was adjusted so that the thickness ratio of the laminate was 1: 2 in the surface layer: intermediate layer. This coextruded sheet was quenched with a casting roll at about 42 ° C. to obtain an unstretched sheet. Subsequently, the film was stretched 2.6 times at 76 ° C. in the longitudinal direction, and then stretched 3.2 times at a temperature of 74 ° C. with a tenter in the width direction. The temperature of the heat treatment zone in the tenter was set to 135 ° C. to produce a heat treated laminate. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the thickness of the laminate was approximately 250 μm on average.

Next, using the obtained sheet, concave-shaped molding was performed. That is, using a molding die (mold temperature: 25 ° C.), the inside of the recess, that is, the surface to be thermocompression bonded to the sheet base material is the surface layer side, and the sheet temperature is 140 ° C. and the pressure is 5 kg / cm ² Pressure forming was performed to obtain a cover material having a recess.

[Cover Material 3]
A polylactic acid polymer having a structural unit of L-lactic acid: D-lactic acid = 99.5: 0.5 (Da = 0.5%) and having a glass transition point (Tg) of 58 ° C. (resin 1 in Table 1) The dried silica particles having an average particle diameter of 1.4 μm: 0.1 parts by weight were mixed and extruded as a front and back layer from a multi-manifold die at 220 ° C. with a 25 mmφ co-directional twin screw extruder.

  Further, it has a structural unit of L-lactic acid: D-lactic acid = 80: 20, 80% polylactic acid having a glass transition point (Tg) of 52 ° C., and has a structural unit of L-lactic acid: D-lactic acid = 95: 5. 20% polylactic acid having a transition point (Tg) of 56 ° C. was mixed and dried to a total of 100 parts by weight of polylactic acid (Db = 17%, resin 5 in Table 1). 1 part by weight was mixed and extruded as an intermediate layer from the die using a 40 mmφ single screw extruder.

  The discharge amount of the molten resin was adjusted so that the thickness ratio of the surface layer, the intermediate layer, and the back layer was 1: 8: 1. This coextruded sheet was quenched with a casting roll at about 43 ° C. to obtain an unstretched sheet. Subsequently, the film was stretched 2.6 times at 76 ° C. in the longitudinal direction, and then stretched 3.2 times at a temperature of 72 ° C. with a tenter in the width direction. The temperature of the heat treatment zone in the tenter was 130 ° C., and a heat treated laminate was produced. The amount of molten resin discharged from the extruder and the line speed were adjusted so that the thickness of the laminate was approximately 250 μm on average.

Next, using the obtained sheet, concave-shaped molding was performed. That is, using a molding die (mold temperature 25 ° C.), pressure air molding was performed under the conditions of a sheet temperature 140 ° C. and a pressure: 4 kg / cm ² to obtain a cover material having a recess.

Example 1
The sheet base material A-1 and the cover material 1 are prepared, the cover material concave portion is housed in a concave mold, the sheet base material is overlaid thereon, and the concave portion peripheral portion of the cover material and the sheet base material are stacked. A blister pack was obtained by thermocompression bonding.

(Examples 2 to 5)
A blister pack having the structure shown in Table 4 was obtained in the same manner as in Example 1.

(Examples 6 and 7)
A blister pack was obtained in the same manner as in Example 1 by arranging the surface layer side of each sheet base material as shown in Table 4 on the surface in contact with the cover material.

(Example 8)
A blister pack having the structure shown in Table 4 was obtained in the same manner as in Example 1.

Example 9
A UV curable ink was applied over the entire surface of the surface layer of the sheet substrate A-1, and the ink was cured with a UV lamp. Thereafter, the printing surface of the sheet substrate A-1 and the sheet substrate B-1 are dry-laminated with a two-component curable urethane adhesive, and the sheet substrate in which the substrate A / the substrate B is integrated is obtained. Obtained.
A blister pack was obtained in the same manner as in Example 1 using the obtained sheet base material and cover material 3.

(Example 10)
A sheet base material A-1 printed by the same method as in Example 9 is prepared, and then the two liquids are formed on the printing surface of the sheet base material A-1 and the intermediate layer (back layer) side of the sheet base material B-3. Dry lamination was performed with a curable urethane adhesive to obtain a sheet base material in which base material A / base material B were integrated.
A blister pack was obtained in the same manner as in Example 1 using the obtained sheet base material and cover material 3.

Example 11
Printing is performed on the surface opposite to the surface to be thermocompression-bonded with the cover material of the sheet base material B-1, by the same method as in Example 9, and then the printing surface side of the sheet base material A-1 and the sheet base material B-1 Was subjected to dry lamination with a two-component curable urethane adhesive to obtain a sheet base material in which base material A / base material B were integrated.
A blister pack was obtained in the same manner as in Example 1 using the obtained sheet base material and cover material 3.

(Comparative Examples 1 and 2)
A blister pack having the structure shown in Table 4 was obtained in the same manner as in Example 1.

(Comparative Example 3)
A blister pack having the structure shown in Table 4 was obtained in the same manner as in Example 9.

(Comparative Example 4)
A blister pack having the structure shown in Table 4 was obtained in the same manner as in Example 1.

[result]
As shown in Table 4, in Examples 1 to 11, good blister packs having no problem in seal strength and seal appearance could be obtained. Moreover, in Examples 9-11, it became a blister pack favorable also about ink adhesiveness.
On the other hand, in Comparative Examples 1, 2, and 4, only a blister pack having a low sealing strength or a poor sealing appearance was obtained. In Comparative Example 3, not only the sealing strength was weak but also the ink adhesion was poor, and the ink layer was easily peeled off from the base material A-7.

Claims (8)

Rutotomoni concave portion is formed for accommodating an article, and a cover member recess perimeter is formed in the periphery of the recess, the blister pack comprising a sheet substrate for closing the concave portion,
The cover material and the sheet base material are both composed of a resin mainly composed of a polylactic acid-based polymer,
The sheet base material is composed of a laminate composed of at least two layers having different crystallinity,
The content ratio Da (%) of D-lactic acid in the polylactic acid polymer constituting the first layer of the laminate and the D-lactic acid content of the polylactic acid polymer constituting the second layer of the laminate. While the relationship of the content ratio Db (%) satisfies the following formula (1), the second layer constitutes at least one outermost layer of the laminate,
Da ≦ 7 and Db−Da> 3 (1)
The second layer constituting the laminate is disposed on a surface in contact with the cover material ,
A biodegradable thermocompression-bonding blister pack , wherein a peripheral portion of a concave portion of the cover material and the sheet base material are thermocompression bonded . Rutotomoni concave portion is formed for accommodating an article, and a cover member recess perimeter is formed in the periphery of the recess, the blister pack comprising a sheet substrate for closing the concave portion,
The cover material and the sheet base material are both composed of a resin mainly composed of a polylactic acid-based polymer,
The sheet substrate is composed of at least two types of substrates A and B,
The base material A and the base material B are each a laminate composed of at least two layers having different crystallinity,
The D-lactic acid content ratio Da (%) of the polylactic acid polymer constituting the first layer of these laminates and the D-lactic acid polymer D- constituting the second layer of these laminates The relation of the content ratio Db (%) of lactic acid satisfies the following formula (1), and the second layer constitutes at least one outermost layer in any of the laminates,
Da ≦ 7 and Db−Da> 3 (1)
A printed layer is provided on the second layer of the substrate A,
The second layer of the base material B is disposed on a surface in contact with the cover material ,
A biodegradable thermocompression-bonding blister pack , wherein a peripheral portion of a concave portion of the cover material and the sheet base material are thermocompression bonded . Rutotomoni concave portion is formed for accommodating an article, and a cover member recess perimeter is formed in the periphery of the recess, the blister pack comprising a sheet substrate for closing the concave portion,
The cover material and the sheet base material are both composed of a resin mainly composed of a polylactic acid-based polymer,
The sheet substrate is composed of at least two types of substrates A and B,
The base material B is a laminate composed of at least three layers, each composed of at least two types of resin layers having different crystallinity,
D-lactic acid content ratio Da (%) of the polylactic acid polymer constituting the first layer of the laminate, and D-lactic acid of the polylactic acid polymer constituting the second layer of these laminates The relationship of the content ratio Db (%) satisfies the following formula (1), and the second layer constitutes both outermost layers of the laminate,
Da ≦ 7 and Db−Da> 3 (1)
Of both outermost layers constituting the base material B, a printing layer is provided on the outermost layer different from the outermost layer in contact with the cover material, and the base material A is laminated on the outermost layer provided with the printing layer ,
The second layer of the base material B is disposed on a surface in contact with the cover material,
A biodegradable thermocompression-bonding blister pack , wherein a peripheral portion of a concave portion of the cover material and the sheet base material are thermocompression bonded .   The biodegradable thermocompression blister according to any one of claims 1 to 3, wherein at least one of the sheet base material and the cover material contains a biodegradable aliphatic polyester other than the polylactic acid resin. pack. Biodegradable thermocompression blister pack according to any one of claims 1 to 4, characterized in that the sheet substrate is biaxially oriented. Biodegradable thermocompression blister pack according to any one of claims 1 to 5, characterized in that the cover material is biaxially stretched. After storing the articles to the cover member, biodegradable thermocompression blister pack according to any one of claims 1 to 6, the sheet substrate and the cover member, characterized in that closed by thermocompression bonding. The biodegradable thermocompression blister pack according to claim 7 , wherein the article is a battery.