JPH05178365A - Polypropylene soft blister pack - Google Patents

Abstract

PURPOSE:To obtain a blister pack which is easily compressible after use and which causes no problem of emitting exhaust gases therefrom at the time of the incineration for disposal by forming the blister pack consisting of an article holding recess made of a thin polypropylene sheet and a lid made of a specific multi-layer polypropylene film. CONSTITUTION:A soft blister pack is formed consisting of an article holding recess and a lid, both being made of the polypropylene materials having a thickness of 100-350mum. The lid is provided with a homopolypropylene layer formed on one side and a crystalline propylene random copolymer layer formed on the other side with a composition consisting of a crystalline propylene random copolymer and a copolymer rubber of polypropylene and olefin interposed therebetween as an intermediate layer and the multi-layer film thus formed serves the purpose of a sealant. The use of the packing materials provides the blister pack with the features of being well formable and compressible after unpacking as well as a combination of an easy peeling with the hand and heat sealing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blister pack, and more particularly to an easy-peelable polypropylene soft blister pack having an easy peel property.

[0002]

2. Description of the Related Art Conventionally, blister packs have been used for packaging in various fields such as foods, medical supplies, sundries, and industrial parts. As the material, hard polyvinyl chloride is mainly used in consideration of the balance of workability, thermoformability and physical properties of the sheet, but polypropylene and high-impact polystyrene are also used. The thickness of the container of these blister packs is usually 200 to 900 μm and is used as a relatively thick rigid container for maintaining the shape of the blister. However, in such a conventional blister pack, the waste gas at the time of incineration of polyvinyl chloride becomes a social problem when it is discarded after use, and a countermeasure for it is required. Further, since a rigid container cannot be easily crushed by hand, it has a problem that it is bulky when it is stored or transported as waste plastic. Further, in the conventional case, there are many cases in which the container and the lid of the recess for storing the package are generally adhesively sealed with an adhesive or the like, and the easy opening property is not sufficient.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a polypropylene type soft blister pack which retains easy-opening property and blister shape, can be easily compressed after use, and has no problem with waste gas of incineration waste and easy to process waste plastic. For the purpose of providing.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a highly transparent polypropylene sheet having a high rigidity even if it is relatively thin is used as a package storage recess, and a lid for a specific polypropylene-based multilayer film is provided. The inventors have found that the above objects can be achieved by combining materials. That is, the present invention includes (a) a package storage recess made of polypropylene sheets having a thickness of 100 to 350 μm, and (b)
A composition comprising (1) a crystalline propylene random copolymer, (2) polyethylene and (3) an olefin-based copolymer rubber is used as an intermediate layer A, a homopolypropylene layer B is provided on one side, and a crystalline propylene random is provided on the other side. A gist of a polypropylene-based soft blister pack is characterized by comprising a cover material having a polypropylene-based multilayer film obtained by laminating a copolymer layer C as a sealant.

The present invention will be described in more detail below. The polypropylene sheets constituting the (a) package accommodating recess in the present invention are made of homopolypropylene, crystalline propylene random or block copolymer. In order to obtain the transparency of these sheets, it is preferable to use a crystalline propylene random copolymer, for example, a propylene-ethylene random copolymer, as the raw material resin. To improve the transparency of these sheets (including films, hereinafter simply referred to as sheets), a nucleating agent may be added to polypropylene as a raw material resin. Examples of the nucleating agent include sorbitol derivatives, sodium adipate, aluminum adipate and the like. Specific examples of the sorbitol derivative include dibenzylidene sorbitol, 1,3,2,4-di (alkylbenzylidene) sorbitol, 1,3,2,4-di (alkoxybenzylidene) sorbitol and the like. Other known additives as described later may be contained as necessary. The thickness of the sheet is 100 to 350 μm
And preferably 150 to 250 μm. Thickness is 10
When the thickness is less than 0 μm, the shape of the package storage recess (blister) is insufficiently maintained. On the other hand, when the thickness exceeds 350 μm, it is easily compressed by hand when discarding the container after opening (generally, a load of 0. 3 to 0.4 kg) and waste plastic becomes bulky, which is not preferable.
Further, the 1% tensile elastic modulus of the sheet is preferably in the range of 7,000 to 10,000 kg / cm ² in terms of shape retention of the package storage recess (blister) and compressibility by hand after opening and using.

Further, (b) a lid material using a polypropylene-based multi-layer film as a sealant includes a surface of the multi-layer film which is not a heat-sealing layer and a base material, for example, a paper material such as a printing mount,
It is a laminate of a metal foil such as an aluminum foil, a synthetic resin film such as a polyester film and a stretched polyamide film, or a sheet. In the polypropylene-based multilayer film, the intermediate layer A has (1) a crystalline propylene random copolymer, preferably propylene-ethylene random copolymer, (2) polyethylene, preferably low-density polyethylene and (3) olefin-based copolymer. Coalescence, preferably consisting of an ethylene-propylene rubber composition. The blending ratio of the composition constituting the intermediate layer A is preferably 10 to 65% by weight of the crystalline propylene random copolymer, more preferably 43 to 63% by weight, and preferably 34 to 89% by weight of polyethylene. Preferably 35-5
5% by weight and olefin copolymer rubber are preferably 1
10 to 10% by weight, more preferably 2 to 5% by weight. A multi-layer film using such a composition as an intermediate layer is excellent in ease of sealing such that delamination is easy and a peeled surface is smooth when the lid material of the blister pack is opened. The homopolypropylene layer B laminated on one surface of the intermediate layer A is an isotactic propylene homopolymer and has a melt flow rate (JIS K7210, load 2.16 kg, 23).
It is preferably 0 ° C., hereinafter referred to as MFR) of 0.3 to 60 g / 10 minutes. The homopolyprene layer B has high rigidity, enables thin-wall molding of the A layer and the C layer of the multilayer film, and allows the multilayer film to have an appropriate elasticity. Further, as the crystalline propylene random copolymer layer C laminated on the other side of the intermediate layer A, the crystalline propylene random copolymer (1) in the composition of the intermediate layer A can be used. This crystalline propylene random copolymer is copolymerized with propylene, ethylene or other α
-The olefin content is preferably 10% by weight or less.
The MFR is preferably 0.3 to 60 g / 10 minutes. This crystalline propylene random copolymer layer C can form a strong heat-sealing layer together with polypropylene on the package storage recess side as a sealing layer of a multilayer film. The above-mentioned multilayer film consisting of the A layer, the B layer and the C layer has a three-layer structure of the composition constituting the A layer, the homopolypropylene constituting the B layer and the crystalline propylene random copolymer constituting the C layer. Coextrude using a die,
Alternatively, the B layer and the C layer as the outer layers can be extrusion-laminated on the A layer formed in advance, but the coextrusion molding is preferable from the viewpoint of delamination property and thinning of the multilayer film. The coextrusion molding may be carried out by any of the known T-die method and inflation method. The thickness of the multilayer film is not particularly limited, but the intermediate layer A made of the composition is
It is usually 1 to 10 μm, preferably 3 to 5 μm. or,
The homopolypropylene layer B has a thickness of usually 10 to 50 μm, preferably 15 to 40 μm. Further, the crystalline propylene random copolymer layer C has a thickness of usually 1 to 10 μm, preferably 3 to 5 μm. By adjusting the thickness ratio of each layer, peel strength, transparency, waist strength, etc. can be adjusted. In any layer or all layers constituting the above-mentioned multilayer film, known additives such as antioxidant, antistatic agent, antifogging agent, antiblocking agent, if necessary,
Lubricants, nucleating agents, pigments and the like can be added. In addition, the polypropylene-based multi-layer film is also disclosed in Japanese Patent Publication No. 3-33106.
The one disclosed in the publication can be applied.

The lamination of the multi-layer film and the lid material is not particularly limited, and methods such as extrusion lamination, dry lamination, and wet lamination, which are generally used for lamination of polyolefin films, can be applied. next,
The method for producing a polypropylene-based soft blister pack of the present invention includes thermoforming such as the plug assist method and pressure forming or vacuum forming according to the shape of the (a) polypropylene sheet or film containing the package (product). A storage recess is formed by a combination, a package (commercial product) is put in the storage recess, and the lid material of the polypropylene-based multilayer film (b) is placed at the end of the storage recess with the crystalline propylene random copolymer layer C side. Heat seal together with the parts. This heat seal has a temperature of 180 to 240 ° C. and a seal pressure of 0.
It is preferable to perform it at 5 to 5 kg / cm ² and a sealing time of 1 to 10 seconds.

The blister pack described above is formed by forming a thin sheet of polypropylene, which is excellent in rigidity, as a storage recess in order to easily compress the blister pack and reduce its volume. In order not to deform this shape, the inside of the package is in a minute pressure state,
For example, it is more preferable to set +1 to 100 mmHg. To make the inside of this blister pack in a minutely pressurized state, the entire packaging equipment or a part thereof is kept in a minutely pressurized state (for example, +1 to 100 mmHg pressure), or
Alternatively, a method in which pressurized air or an inert gas (for example, at a pressure of 0.1 to 1.0 kg / cm ² ) is directly enclosed in the container during packaging may be used.

[0009]

The polypropylene soft blister pack of the present invention is composed of a concave portion for accommodating a thinner polypropylene sheet and a lid material for a specific polypropylene multi-layer film, so that it can be easily opened by hand. It has both peeling property and heat sealing. Further, although the accommodating recess is a relatively thin sheet, it is made of polypropylene which is excellent in rigidity and heat resistance, and has shape retention and transparency. Further, the polypropylene sheet is thinner than conventional ones, is easy to mold, and the storage recess can be easily compressed by hand to reduce the volume thereof.

[0010]

EXAMPLES The present invention will be specifically described below with reference to examples. (1) Production of polypropylene sheet Raw material resin I [propylene-ethylene random copolymer (MFR 9 g / 10 min, ethylene content 3.6% by weight,
Nucleating agent (1,3,2.4-di (alkylbenzylidene))
0.5 wt% sorbitol)], and II [propylene-ethylene random copolymer (MFR 1.3 g
/ 10 minutes, ethylene content 3.0% by weight, nucleating agent 0.5
% By weight)] was extruded by a T-die method at a resin temperature of 230 ° C. to form sheets I and II having a thickness of 200 μm. The physical properties of this core sheet are shown in Table 1.

[0011]

[Table 1] Test method Haze: Compliant with ASTM D1003 Gloss: Compliant with ASTM D523 1% Tensile modulus: ASTM D882 Degradation strength: Compliant with JIS K7113 Break strength: Compliant with JIS K7113: Elongation at break: Compliant with JIS K7113

(2) Production of polypropylene-based multilayer film and lid material Propylene-ethylene random copolymer (ethylene content 3.6% by weight, MFR 9.0 g / 10 min) 48% by weight, low density polyethylene (density 0. 923 g / cm ³ ,
MI (JISK7210, load 2.16kg, 230 ℃)
6.0 g / 10 min) 50% by weight and ethylene-propylene rubber (Mooni viscosity ML _{1 + 8} 127 ° C. 25, ethylene content 40% by weight) 2% by weight were used as an intermediate layer, and one side was homogenous. Polypropylene (MFR 9.0 g /
10 minutes, Homo PP) outer layer and the other side of the propylene-ethylene random copolymer (MFR 9.0g / 10 minutes,
It was supplied to a co-extrusion device of T-die method so as to form an outer layer having an ethylene content of 3.6% by weight and a PP random), and coextruded at a resin temperature of 240 ° C. to form a 25 μm-thick three-layer film (homo PP / composition). Material / Random PP = 15 μm / 5 μm
/ 5 μm) was obtained. The homopolypropylene layer of the obtained three-layer film and the base material of the polyester film having a thickness of 15 μm were laminated by dry lamination of urethane adhesive to obtain a lid material.

EXAMPLES AND COMPARATIVE EXAMPLES The polypropylene sheets I and II were preheated and then subjected to plug-assisted pressure forming to form a storage recess for the ampoule containing the drug, and the ampoule containing the drug was housed therein. A lid material having a polypropylene-based three-layer film as a sealant was overlaid on the PP random side on the upper end of the ampoule storage recess and heat-sealed at a sealing temperature of 200 ° C. to obtain each blister pack. Each blister pack had sufficient sealing properties and maintained its shape. Further, the opening was such that the peeling surface was clean with a sealing strength that could be easily peeled by hand. Furthermore, the container from which the ampoule having the contents was taken out could be easily crushed by hand, and the volume could be reduced to 1/3 or less. In addition,
For comparison, a hard polyvinyl chloride sheet having a thickness of 300 μm used in a conventional blister pack was formed with a storage recess in the same manner as in the above-mentioned example, and a thickness of 25 μ was formed in the storage recess.
A polyvinyl chloride film lid material of m was attached with an adhesive to obtain a blister pack. Although a blister pack made of polyvinyl chloride has a sufficient sealing property, it cannot be easily opened by hand. Also, the container after taking out the contents is
I couldn't easily crush it by hand.

[0014]

As described above in detail, the blister pack of the present invention has an easy opening property in addition to the sealing property and the shape maintaining property. In addition, since the polypropylene sheet is thinner than the conventional one, the amount of resin used is small, and the container from which the contents are taken out can be easily compressed by hand. Therefore, since the amount of waste plastic is small and not bulky, storage and transportation are easy and economical. Further, when incinerated as waste plastic, it is not necessary to take measures against waste gas such as polyvinyl chloride.

Claims (1)

[Claims] 1. A package storage recess comprising (a) a polypropylene sheet having a thickness of 100 to 350 μm, and (b).
A composition comprising (1) a crystalline propylene random copolymer, (2) polyethylene and (3) an olefin-based copolymer rubber is used as an intermediate layer A, a homopolypropylene layer B is provided on one side, and a crystalline propylene is provided on the other side. A polypropylene-based soft blister pack comprising a polypropylene-based multilayer film obtained by laminating a random copolymer layer C as a sealant.