JP6724680B2 - Multilayer sheet for PTP and PTP using the same - Google Patents

Description

The present invention relates to a multi-layer sheet for PTP. Specifically, it is a multi-layer sheet for PTP that can be manufactured at low cost, is excellent in productivity and workability, is excellent in transparency, slipperiness, impact resistance, and easy to take out contents, and has high moisture resistance, And PTP using the same.

In the field of packaging pharmaceuticals, foods, etc., PTPs (press-through packages) are widely used for packaging solid agents such as capsules and tablets, and granular foods.

PTP is, for example, after heating a transparent sheet to form a pocket portion for storing a solid substance such as a capsule or a tablet by performing pressure forming, vacuum forming or the like, and after storing the capsule or the like in the pocket portion, For example, it is a package in which foil or film made of a material such as an aluminum foil that can be easily torn or opened by hand is bonded and integrated as a lid material. PTP allows you to directly check the solid agent, food, etc. stored in the transparent sheet pocket before opening, and when opening, press the solid agent etc. in the pocket with your finger to break the lid material. , The contents can be easily taken out.

Polyvinyl chloride resin (hereinafter sometimes referred to as “PVC”), polypropylene resin (hereinafter sometimes referred to as “PP”) and the like are generally used as the raw material of the PTP sheet, but have high moisture resistance. For the applications requiring the, a technique for laminating a polyvinylidene chloride resin (hereinafter sometimes referred to as “PVDC”) layer on a PVC or PP sheet is known.

PVDC is widely used as various moisture-proofing agents (layers) due to its low moisture permeability, but it is brittle as a material due to its high crystallinity, and is a material that is weak against deformation such as impact or bending. Is. As a technique for improving the brittleness, for example, a technique in which a flexible layer is formed by mixing a low molecular weight PVDC with an impact resistance agent such as an acrylic resin or a high molecular weight PVDC having a low crystallinity is known. However, PVDC having such flexibility has a problem that the moisture-proof property is deteriorated. The PVDC layer is mainly formed by applying an emulsion dispersed in a water-based solvent on a substrate and drying the emulsion. Due to the difficulty, there is a problem that the film thickness per single layer is limited. As a technique for improving these, there is known a technique in which a relatively thin layer having impact resistance and a relatively thin layer having high moisture resistance are alternately formed in a sandwich structure (Patent Document 1). Although this method provides a good balance between moisture resistance and impact resistance, it requires repeated coating and drying to form a layer, so the manufacturing cost is very high, and the productivity and yield are high. The problem is that it is also bad.

Other techniques for improving the brittleness of PVDC include a technique of providing a polyethylene resin layer having a low glass transition point between a PVDC layer and a PVC layer (Patent Documents 2 and 3) and a technique of providing a polyester resin (Patent Document 4). ) Is also known. However, when a layer of polyethylene or polyester is provided, the total thickness becomes thicker by that amount, and thus the ease of taking out (extrudability) when taking out contents such as tablets when used as PTP from the pocket becomes poor. .. In addition, problems such as difficulty in slitting occur in the PTP manufacturing process, hand-cutability of the PTP sheet itself becomes poor, and usability as a PTP sheet becomes poor.

By the way, as described above, as a method of forming a PVDC layer, there is a technique of providing a PVDC layer on a PVC substrate by a coating method. In this method, fine particles of PVDC resin are used to form a micelle structure with a surfactant. Generally, a method in which the latex dispersed in (1) is applied, dried and formed. However, this method tends to cause agglomeration of fine particles in the drying step, and a large vortex or turbulence is easily generated inside the liquid during the process of vaporizing the solvent in the coating liquid, and due to the influence of the surfactant, the coating liquid However, when the coating film becomes thick, the surface after drying tends to become rough. If the roughness of the sheet surface is too large, when the sheet is molded into PTP, the transportability of the sheet on the molding line deteriorates, which causes troubles such as catching. On the other hand, if the roughness is too small, meandering or slipping is likely to occur during sheet conveyance or molding, so controlling the roughness of the sheet surface is also an important point for practical performance.

By the way, recently, a type of tablets called OD (Oral Disintegration) tablets (orally disintegrating tablets) that can be taken without water is increasing. OD tablets have the feature that they can be taken anywhere, and that they are easy to take for people with dysphagia, those who are not good at swallowing tablets, children, etc. , Fragile. For this reason, the packaging for OD tablets is required to have a higher level of moisture resistance than conventional ones.
A sheet that can meet all of the above recent required qualities, that is, can be produced at low cost, has excellent productivity and processability, and is easy to take out tablets (extrudability) and transparency, The present situation is that a PTP sheet that has excellent impact resistance and can be used for packaging contents such as OD tablets that require high moisture resistance has not yet been obtained.

JP, 2014-43089, A JP 61-268444 Japanese Patent Publication No. 024587/49 JP, 11-138725, A

The present invention has been studied in view of such problems of the conventional technology, and the object of the present invention is to be able to manufacture at low cost, excellent in productivity and workability, transparency and slippage. It is intended to provide a multi-layer sheet for PTP which has excellent moisture resistance, impact resistance, and extrudability and has high moisture resistance.

As a result of diligent studies, the present inventors have succeeded in obtaining a sheet that can solve the above-mentioned problems of the prior art, and have completed the present invention. That is, an object of the present invention is a multi-layer sheet for PTP, which comprises a polyvinyl chloride resin (A) layer as a base material and a polyvinylidene chloride resin (B) layer laminated on at least one surface of the base material. The polyvinylidene chloride resin (B) layer is formed by laminating at least one set of one layer each of the (B)-1 layer and the (B)-2 layer on a substrate. , The thickness ratio of the set to be laminated next to the set closest to the base material is in the range of 0.3 to 0.75, and the set (B)-1 layer and (B)-2 of the set closest to the base material. This is achieved by a multi-layer sheet for PTP characterized in that each layer has a thickness in the range of 7 to 20 μm.

ADVANTAGE OF THE INVENTION According to this invention, the multilayer sheet for PTPs which can be manufactured at low cost, is excellent in productivity and workability, is excellent in transparency, slipperiness, impact resistance, and extrudability, and has high moisture resistance. Since it can be provided, it can be suitably used for applications that require a higher level of moisture proof than ever before.

FIG. 3 is a diagram for explaining the layer structure of the sheet of Example 1. FIG. 5 is a diagram for explaining the layer structure of the sheet of Example 2; FIG. 5 is a diagram for explaining the layer structure of the sheet of Example 3; FIG. 5 is a diagram for explaining a layer structure of a sheet of Comparative Example 1. FIG. 5 is a diagram for explaining a layer structure of a sheet of Comparative Example 2. FIG. 8 is a diagram for explaining a layer structure of a sheet of Comparative Example 3. FIG. 9 is a diagram for explaining a layer structure of a sheet of Comparative Example 4. FIG. 8 is a diagram for explaining a layer structure of a sheet of Comparative Example 5.

Hereinafter, a multi-layer sheet for PTP (hereinafter, also referred to as “present sheet”) as an example of an embodiment of the present invention will be described. However, the scope of the present invention is not limited to the embodiments described below.

In addition, in this specification, "having as a main component" means that other components are allowed within a range that does not impair the action and effect of the resin contained as a main component. Furthermore, this term does not limit the specific content, but it is 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more and 100% by mass or less of the whole constituent components. Is a component occupying the range of.

<Polyvinyl chloride resin (A)>
As the polyvinyl chloride resin (A) used in the present invention, a vinyl chloride resin having an arbitrary average degree of polymerization can be used, and preferably 600 to 1,300. If the average degree of polymerization is 600 or more, sufficient mechanical strength can be obtained. On the other hand, when the average degree of polymerization is 1,300 or less, heat generation due to increase in melt viscosity does not occur and coloring due to decomposition is less likely to occur.
From this point of view, the average degree of polymerization of the polyvinyl chloride resin (A) is more preferably 600 or more or 1,100 or less, and more preferably 650 or more or 900 or less, in the above range. Is more preferable.

Examples of the polyvinyl chloride resin (A) include not only vinyl chloride homopolymers (referred to as “vinyl chloride homopolymers”) but also copolymers of vinyl chloride and a copolymerizable monomer (hereinafter referred to as “vinyl chloride homopolymer”). , "Vinyl chloride-based copolymers"), graft copolymers obtained by graft-copolymerizing vinyl chloride to polymers other than this vinyl chloride-based copolymer (hereinafter, vinyl chloride-based graft copolymers), etc. Can be mentioned.

The vinyl chloride-based copolymer has poor mechanical properties when the content of constituent units other than vinyl chloride in the copolymer increases, so that the proportion of vinyl chloride in the vinyl chloride-based copolymer is 60 to 60%. It is preferably 99% by mass.
The vinyl chloride homopolymer and the vinyl chloride copolymer can be polymerized by any method such as emulsion polymerization method, suspension polymerization method, solution polymerization method, bulk polymerization method and the like.

Here, the monomer copolymerizable with the vinyl chloride may be any one having a reactive double bond in the molecule. For example, α-olefins such as ethylene, propylene and butylene, vinyl acetates such as vinyl acetate and vinyl propionate, vinyl ethers such as butyl vinyl ether and cetyl vinyl ether, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, and methyl acrylate. , Acrylic acid or methacrylic acid esters such as ethyl methacrylate and phenyl methacrylate, aromatic vinyls such as styrene and α-methylstyrene, vinyl halides such as vinylidene chloride and vinyl fluoride, N-phenylmaleimide, Examples thereof include N-substituted maleimides such as N-cyclohexylmaleimide, and these can be used alone or in combination of two or more.

The polymer other than the vinyl chloride-based copolymer may be any polymer that can graft-copolymerize vinyl chloride. For example, ethylene/vinyl acetate copolymer, ethylene/vinyl acetate/carbon monoxide copolymer, ethylene/ethyl acrylate copolymer, ethylene/ethyl acrylate/carbon monoxide copolymer, ethylene/methyl methacrylate copolymer, ethylene -Propylene copolymer, acrylonitrile-butadiene copolymer, polyurethane, chlorinated polyethylene, chlorinated polypropylene and the like can be mentioned, and these can be used alone or in combination of two or more kinds.

Further, various additives may be added to the polyvinyl chloride resin (A) within a range not impairing the effects of the present invention.
For example, a Ca-Zn stabilizer may be added to improve the thermal stability of the polyvinyl chloride resin (A). The Ca-Zn stabilizer is a mixture of fatty acid salt of calcium and fatty acid salt of zinc. Specific examples of the fatty acid include behenic acid, stearic acid, lauric acid, oleic acid, palmitic acid, ricinoleic acid, benzoic acid and the like, and two or more kinds may be used in combination depending on the purpose. Further, other stabilizers such as alkyl tin male, alkyl tin laurate, alkyl tin mercapto, and tin mercapto acid ester can also be used.

Also, impact modifiers such as MBS resin, ABS resin, acrylic rubber containing butyl acrylate as a main component, lubricants such as aliphatic alcohol, fatty acid ester, and fatty acid metal salt, or ultraviolet absorption of salicylate ester, benzophenone, benzotriazole, etc. Agents, plasticizers, antistatic agents, pigments, and resins other than PVC can be added.

<Polyvinyl chloride resin (A) layer>
The method for forming the polyvinyl chloride resin (A) layer is not particularly limited, but it can be formed by a method such as extrusion molding, calender molding or press molding. The thickness of the polyvinyl chloride resin (A) layer can be appropriately selected generally in the range of about 50 to 250 μm.

<Polyvinylidene chloride resin (B)>
As the polyvinylidene chloride resin (B) used in the present invention, a vinylidene chloride monomer or a copolymer with various monomers can be used. Specific examples of the copolymerization monomer include vinyl chloride, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid and maleic acid, aromatic vinyl compounds such as α-methylstyrene and vinyltoluene, and (meth)acryl. (Meth)acrylic acid esters such as methyl acrylate, ethyl (meth)acrylate, hydroxylethyl (meth)acrylate, glycidyl methacrylic acid acrylate, (meth)acrylamide, N-methylol (meth)acrylamide, etc. Examples thereof include (meth)acrylamide, and these can be used alone or in combination of two or more kinds. The method for producing the polyvinylidene chloride resin (B) is not particularly limited, but a known method such as emulsion polymerization method can be adopted. Specific examples of commercial products of the polyvinylidene chloride resin (B) include Asahi Kasei Chemicals Corporation's trade name “Saran Latex” series and Solvay's trade name “Diofan” series.

<Structure of polyvinylidene chloride resin (B) layer>
In the present invention, the polyvinylidene chloride resin (B) layer comprises one set of each of the (B)-1 layer and the (B)-2 layer, and at least one set is laminated on the substrate. The thickness ratio of the set to be laminated next to the set closest to the substrate is in the range of 0.3 to 0.75, and the set (B)-1 layer and the layer (B) closest to the substrate are -It is important that the thickness of each of the -2 layers is in the range of 7 to 20 m.

The thickness ratio of the next set to the set closest to the base material is 0.3 to 0.75, preferably 0.3 to 0.7, and more preferably 0.3 to 0.6. The thickness of each of the (B)-1 layer and the (B)-2 layer closest to the substrate is 7 to 20 μm, preferably 7 to 15 μm, and more preferably 7 to 10 μm. If the upper limit of the thickness ratio of the next set is within the above range, problems such as the surface of the polyvinylidene chloride-based resin (B) layer becoming too rough and easily cracking do not occur, and the lower limit is within the above range. Within the range, the polyvinylidene chloride resin (B) layer does not become too smooth, and the moisture resistance is sufficient. When the upper limit of the thickness of the set close to the base material is within the above range, the surface roughness of the polyvinylidene chloride resin (B) layer does not become too large, and the transparency and extrudability of the sheet are good. This is preferable because the obtained product is obtained, and the moisture resistance and impact resistance are not deteriorated due to the generation of cracks in the coating film. The thickness of the (B)-1 layer and the (B)-2 layer of the next set is preferably 2 to 14 μm. Further, the number of sets may be three or more as required.

(B) As the polyvinylidene chloride-based resin (B) used in the 1 ^layer, the 1046Cm -1 / absorbance ratio of 1070 cm ^-1 is 1.05 to 1.40 polyvinylidene chloride-based resin (B) -1 It is preferable to use. Also, (B) As the polyvinylidene chloride-based resin (B) used in the 2 ^{layer, 1046cm} -1 / absorbance ratio of 1070 cm ^-1 is 0.80 to 1.05 polyvinylidene chloride-based resin (B) - It is preferable to use 2.

The more preferable range of the absorbance ratio of the polyvinylidene chloride resin (B)-1 at 1046 cm ^-1 /1070 cm ^-1 is 1.06 to 1.38, and the more preferable range is 1.07 to 1.35. (B) If the absorbance ratio of -1 ^{1046cm -1} / ^1070cm -1 is below this range, it is impossible to impart sufficient moisture ^resistance, while the range of the absorbance ratio 1046cm ^-1 / 1070cm -1 is applied If it exceeds, the crystallinity becomes too high and the transparency may decrease. Furthermore, more preferable range of the absorbance ratio of polyvinylidene chloride resin (B) -2 of ^{1046cm -1} / ^1070cm -1 is 0.82 to 1.04, still more preferably in the range of at 0.85 to 1.03 is there. (B) If the ratio of the absorbance at ^{1046cm -1} / ^1070cm -1 -2 is below this range, there are cases where significant loss of moisture ^resistance, while if exceeding the range absorbance ratio of 1046cm ^-1 / 1070cm -1 is applied , In some cases, sufficient impact resistance cannot be obtained.

The method for calculating the absorbance ratio at 1046 cm ^-1 /1070 cm ^-1 is as follows. The latex of polyvinylidene chloride resin (B) is applied to a biaxially oriented polypropylene film (hereinafter referred to as OPP film) so that the applied amount after drying will be about 8 g/m ² . Then, after drying at 80° C. for 15 seconds, heat treatment is performed at 40° C. for 16 hours. Then, using a Fourier transform infrared spectrophotometer, the spectrum of 1200 to 800 cm ⁻¹ of the OPP film coated with the polyvinylidene chloride resin (B) is measured. In the obtained spectrum, connected by lines to 1100 cm ^-1 and 850 cm ^-1, this line as the base peak intensity of 1046Cm ^-1 and 1070 cm ^-1 were measured, the absorbance ratio (the 1046Cm ^-1 absorbance / 1070 cm ^-1 Absorbance) was calculated. The larger the absorbance ratio, the higher the crystallinity.

<Method for forming polyvinylidene chloride resin (B) layer>
The method for forming the polyvinylidene chloride resin (B) layer is not particularly limited, but, for example, a bar coat, a gravure coat, a spray coat, a curtain coat, an air knife is formed on the polyvinyl chloride resin (A) layer. It can be formed by applying by a method such as coat, die coat, roll coat, slide coat, and the like, and passing through a drying step. In addition, for the purpose of improving the adhesive force with the polyvinyl chloride resin (A) layer, for example, an isocyanate resin or a urethane resin is provided between the polyvinyl chloride resin (A) layer and the polyvinylidene chloride resin (B) layer. The anchor coat layer may be provided by using an anchor coating agent such as a system-based or polyol-based anchor coating agent.

<Sheet property: moisture resistance>
The moisture resistance of the PTP sheet is appropriately selected depending on the application, but one of the features of the present invention is that it can provide a sheet applicable to applications where higher moisture resistance is required. Moisture resistance can be evaluated by the water vapor transmission rate, and this sheet has a water vapor transmission rate of 0.3 g/m ² ·day or less measured in 40° C. and 90% RH atmosphere in accordance with JIS K7129B. Is preferable, and it is more preferable for practical use that it is 0.25 g/m ² ·day or less. When the water vapor transmission rate is within the above range, it can be used for applications requiring high moisture resistance such as for OD tablets.

<Sheet properties: drop impact resistance>
The drop impact resistance of a sheet is closely related to moisture resistance. This is because when the sheet is impacted by being dropped or the like, and the polyvinylidene chloride resin (B) layer is cracked, chipped or cracked, the moisture resistance of the sheet is deteriorated. From this point of view, it is practically required that the present sheet is subjected to an impact drop test and has no defects.
The impact drop test in the present invention is performed as follows. The polyvinylidene chloride resin (B) layer was formed on the sheet by using FBP-300E manufactured by CKD Co., Ltd. as a molding device for PTP under the conditions of sheet heating temperature 125° C., pocket size Φ10 mm, and depth 4.5 mm. After thermoforming so that it is on the outside of the convex portion, a tablet is put therein and sealed with an aluminum foil having a thickness of 20 μm to prepare a tablet-containing PTP sample. After storing this PTP sample containing tablets for 24 hours at a temperature of 5° C., 100 test pieces were dropped onto a concrete surface from a height of 2 m to visually observe the state of the polyvinylidene chloride resin (B) layer. Check and measure the number of defective samples with cracks and chips.

<Sheet properties: extrudability>
In this sheet, the ease of taking out the contents such as tablets (extrudability) when PTP is used is preferably 2 points or more, more preferably 3 points or more in the sensory evaluation test. Extrudability is an index that leads to consumer feeling of use. Whether or not the product is preferred by consumers is an important factor that affects the commercial value of the package contents, and is one of the important factors among the functions required for the package. For example, recently, in the field of generic drugs with severe competition, it is required as one of the quality of PTP sheets that the index of extrudability satisfies the above range.
The extrudability evaluation method in the present invention is based on a sensory test. Specifically, the method described in Examples described later is used. The higher the evaluation point, the better the extrudability.

<Sheet property: surface roughness (Rz)>
In this sheet, the surface roughness (10-point average roughness: Rz) of the surface of the polyvinylidene chloride-based resin (B) layer measured according to JIS B0601 is 2.0 μm or more and 4.0 μm or less. preferable. If the surface roughness is within the above range, the sheet does not slip too much to cause meandering or slipping, and conversely, the sheet does not slip and is not caught, and troubles such as catching do not occur. It will be good.

<Sheet property: transparency>
The haze of this sheet measured according to JIS K7361 is preferably 20% or less, and more preferably 15% or less. In many cases, the product name or the like is printed on the lid material of PTP, and when the haze exceeds 15%, the target printed matter becomes slightly invisible, and when it exceeds 20%, it becomes difficult to visually recognize it at a glance.

<Use of this sheet>
This sheet can be formed into molded articles of various shapes by vacuum forming, pressure forming, pressure air vacuum forming, press forming, and other thermoforming, and it is preferable to produce and use a formed article for packaging of PTP packaging. You can

As a method for producing a molded sheet for PTP packaging, the multilayer sheet of the present invention is heated and softened with a heating plate before molding, the sheet is sandwiched with a molding die, and compressed air is injected to conform to the concave shape of the molding die. A large number of pockets may be formed in the seat surface. Further, if necessary, it is possible to raise and lower the plug at an appropriate timing during pressurized air injection to assist the moldability.

Along with the above thermoforming, an aluminum foil, an aluminum vapor deposition film, a plastic film (for example, a biaxially oriented polypropylene film, a nylon film, an ethylene-vinyl alcohol copolymer film) or the like is laminated on the front surface or the back surface or both surfaces of the sheet. It is also possible. It is also possible to form a composite sheet by laminating aluminum foil or the various films described above on the front surface, the back surface, or both surfaces of the sheet, and then thermoform this.

The sheet may be embossed or frosted on the surface of the sheet for the purpose of improving the design and secondary processability of the product. In this case, even if you create a mirror-like sheet and then process it with an embossing roll or matte roll, change the cast roll to an embossing roll or matte roll during extrusion molding. May be. As long as the gist of the present invention is not impaired, the surface of the sheet may be coated with an antistatic agent, silicone, wax or the like, or a film may be formed using a surface protection sheet for the purpose of preventing scratches, and a printing layer may be provided It is also possible. Any known means can be adopted as the means for forming the print layer. If necessary, other layers, for example, various functional layers such as vapor deposition layers may be appropriately selected and laminated. In addition, the present sheet has a structure such as (A)/(B)/(B)/(A), (B)/(A)/(A)/(B), etc. It can also be a sheet.

This sheet can be manufactured in a simple process at low cost, has excellent transparency, slipperiness, impact resistance, content retrievability, and high moisture resistance, so it is a solid formulation such as capsules and tablets in the field of pharmaceutical packaging. It can be preferably used as a PTP packaging for packaging granular foods, etc., especially for applications requiring moisture resistance.

The present invention will be described below with reference to examples, but the present invention is not limited thereto. The measured values and evaluations shown in the examples were carried out as follows. Further, in the examples, the flow direction in the production of the sheet is described as "longitudinal direction", and the direction orthogonal thereto is described as "lateral direction".

<Evaluation method>
(1) Water vapor transmission rate With respect to the sheets obtained in the examples, based on JIS K7129B, using a water vapor transmission rate measuring apparatus PERMATRAN-W 1/50 manufactured by MOCON, under an atmosphere of 40° C. and 90% RH, The water vapor transmission rate was measured and evaluated according to the following criteria.
◎: 0.22 or less ○: 0.22 or more and 0.25 or less △: 0.25 or more and 0.3 or less ×: 0.3 or more

(2) Drop impact resistance The sheets obtained in the examples were subjected to a sheet heating temperature of 125° C., a pocket size of Φ10 mm, and a depth of 4.5 mm by using CBP's FBP-300E as a PTP molding device. After heat-molding so that the polyvinylidene chloride resin (B) layer is on the outside of the convex portion, a tablet is put therein and sealed with an aluminum foil having a thickness of 20 μm to prepare a tablet-containing PTP sample.
After storing this PTP sample containing tablets for 24 hours in an environment of a temperature of 5° C., 100 test pieces were dropped onto a concrete surface from a height of 2 m to visually observe the state of the polyvinylidene chloride resin (B) layer. The number of defective samples with cracks and chips was measured and evaluated according to the following criteria.
○: No defective sample ×: There is a defective sample

(3) Extrudability PTP containing tablets is prepared in the same manner as above. With respect to this PTP containing tablets, a monitoring test was carried out in which five test subjects, male and female, aged 10 to 60, a total of 60, extruded tablets from the PTP and took them out. Each subject evaluated the average value of the evaluation points as extrudability. The criteria for evaluation points are as follows.
0 points: Not taken out 1 point: It is extremely difficult to take out 2 points: It is slightly difficult to take out 3 points: It is neither easy to take out nor difficult to take out 4 points: It is easy to take out 5 points: Very easy to take out

(4) Surface roughness (Rz)
According to JIS B0601, the surface roughness (10-point average roughness: Rz) of the PVDC layer surface was measured using Surftest SV2100M4 manufactured by Mitutoyo Corporation, and evaluated according to the following criteria.
◯: 2.0 to 4.0
X: less than 2.0 or more than 4.0

(4) Transparency According to JIS K7136, the haze value was measured using a haze meter NDH-7000 manufactured by Nippon Denshoku Co., Ltd.

<Materials used>
Polyvinyl chloride resin (A) layer:
(A)-1: Rigid PVC sheet (vinyl foil C-0459, thickness=0.09 mm)
Polyvinylidene chloride resin (B) layer:
(B)-1: "Saran latex L574A" manufactured by Asahi Kasei Chemicals Corporation (absorbance ratio=1.10)
(B)-2: "Saran Latex L580C" manufactured by Asahi Kasei Chemicals Corporation (absorbance ratio=0.96)

<Example 1>
First set of polyvinylidene chloride resin (B) layer formation: (A)-1 as a base material, and using a bar coater, apply (B)-1 at a coating amount of 15 g/m ^{2 and} at 80° C. It was dried for 60 seconds. After drying with a micrometer, the film thickness was measured and found to be 10 μm. On this (B)-1 layer, (B)-2 was applied at a coating amount of 15 g/m ² using a bar coater and dried at 80° C. for 60 seconds. (B)-The film thickness of the -2 layer after drying was 10 m.
Second set of polyvinylidene chloride-based resin (B) layer formation: (B)-on the (B)-2 layer formed in the first set, using a bar coater, at a coating amount of 7.5 g/m ² (B)- 1 was applied and dried at 80° C. for 60 seconds. The film thickness of this (B)-1 layer after drying was 5 μm. Further, (B)-2 was applied onto the (B)-1 layer at a coating amount of 7.5 g/m ² using a bar coater and dried at 80° C. for 60 seconds. The film thickness of the (B)-2 layer after drying was 5 μm.
The sheet thus obtained was evaluated. The results are shown in Table 1.

<Example 2>
Polyvinylidene chloride-based resin (B) layer forming second set (B)-1 layer and (B)-2 layer, respectively, except that the coating amount was 10.5 g/m ² and the film thickness after drying was 7 μm. A sheet was prepared in the same manner as in Example 1. The sheet was evaluated. The results are shown in Table 1.

<Example 3>
Polyvinylidene chloride-based resin (B) layer formation First set (B)-1 layer and (B)-2 layer, respectively, except that the coating amount was 10.5 g/m ² and the film thickness after drying was 7 μm. A sheet was prepared in the same manner as in Example 1. The sheet was evaluated. The results are shown in Table 1.

<Comparative Example 1>
The coating amount of the polyvinylidene chloride resin (B) layer forming first set (B)-1 layer and (B)-2 layer was 7.5 g/m ² and the film thickness after drying was 5 μm. This set was performed three more times, for a total of four sets. The sheet was evaluated. The results are shown in Table 2.

<Comparative example 2>
The polyvinylidene chloride-based resin (B) layer forming second set (B)-1 layer and (B)-2 layer each had a coating amount of 3.8 g/m ² and a film thickness after drying of 2.5 μm. A sheet was prepared in the same manner as in Example 1 except for the above. The sheet was evaluated. The results are shown in Table 2.

<Comparative example 3>
Polyvinylidene chloride-based resin (B) layer forming First set of (B)-1 layer and (B)-2 layer were respectively coated at a coating amount of 7.5 g/m ² and a film thickness after drying of 5 μm. Example 2 except that the coating amount of the vinylidene resin (B) layer forming second set (B)-1 layer and (B)-2 layer was 15 g/m ² and the film thickness after drying was 10 μm, respectively. A sheet was created similarly. The sheet was evaluated. The results are shown in Table 2.

<Comparative example 4>
A sheet was prepared in the same manner as in Example 1 except that the second set of PVDC layer formation (B)-1 layer and (B)-2 layer each had a coating amount of 12 g/m ² and a film thickness after drying of 8 μm. did. The sheet was evaluated. The results are shown in Table 2.

<Comparative Example 5>
The polyvinylidene chloride-based resin (B) layer forming first set (B)-1 layer and (B)-2 layer each had a coating amount of 37.5 g/m ² and a film thickness after drying of 25 μm. Implementation except that the coating amount of the second set of (B)-1 layer and (B)-2 layer of the system resin (B) layer formation was 11.3 g/m ² and the film thickness after drying was 7.5 μm, respectively. A sheet was prepared in the same manner as in Example 1. The sheet was evaluated. The results are shown in Table 2.

The sheets of the present invention obtained in Examples 1 to 3 were all excellent in moisture resistance, impact resistance, extrudability, transparency and surface roughness. On the other hand, Comparative Examples 1 to 5 were inferior in quality to any of the sheets of Examples 1 to 3.

The multilayer sheet for PTP of the present invention can be manufactured at low cost, is excellent in productivity and processability, is excellent in transparency, slipperiness, impact resistance, content retrievability, and has high moisture resistance. Therefore, for example, it can be suitably used for packaging applications such as solid agents such as capsules and tablets and granular foods.

Claims (3)

A multilayer sheet for PTP, comprising a polyvinyl chloride resin (A) layer as a base material, and a polyvinylidene chloride resin (B) layer laminated on at least one surface of the base material,
The polyvinylidene chloride-based resin (B) layer is formed by using the polyvinylidene chloride-based resin (B)-1 having an absorbance ratio of 1046 cm ⁻¹ /1070 cm ⁻¹ of 1.05 to 1.40 (B)- One set of one layer and one layer of (B)-2 layer made of polyvinylidene chloride resin (B)-2 having an absorbance ratio of 0.86 to 1.05 of 1046 cmcm ⁻¹ /1070 cmcm ^−1. As a result, at least one set is laminated on the base material, and the thickness ratio of the set to be laminated next to the set closest to the base material is in the range of 0.3 to 0.75, and A multilayer sheet for PTP, wherein the thickness of the (B)-1 layer and the (B)-2 layer of the closest set are each in the range of 7 to 20 μm. The multi-layer sheet for PTP according to claim 1, which has a water vapor transmission rate of 0.25 g/m 2 ·day or less when measured in an atmosphere of 40° C. and 90% RH in accordance with JIS K7129B. .. A PTP comprising the multilayer sheet for PTP according to claim 1 or 2 .

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