JP2003165189A - Composite film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite film which has good moldability, sealability and easy peelability and can be suitably used for suppository packaging. SOLUTION: A polybutylene terephthalate resin layer, an amorphous polyester resin layer, a cohesion failure layer, and a seal layer are laminated in this order from at least an outer layer, and the thickness of the polybutylene terephthalate resin layer is 1 to 20% of the whole, A composite film, wherein the thickness of the polyester resin layer is 30 to 90% of the whole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite film having good moldability, sealing property and easy peeling property, which can be suitably used for suppository packaging.

[0002]

2. Description of the Related Art Conventionally, as a suppository packaging film, a film made of a polyvinyl chloride resin (PVC) film, which is excellent in moldability and heat resistance during sealing, has been used. Mainly, a polyethylene (PE) resin was extrusion-laminated on a PVC film, a suppository was packaged, and then peeled between the PVC film and the PE layer and opened.

[0003]

The above-mentioned PVC components that have been used conventionally have been shunned as a compound containing chlorine due to the problem of waste. However, there is no base material that can substitute for PVC in terms of moldability, stiffness, and heat resistance during sealing.
Further, when a method of producing only one time by co-extrusion is adopted for improving productivity, there is a problem such as a film remaining at the time of opening due to easy peel. Since the packaging machine for suppositories generally has an integral structure for the molding and sealing steps, and the molding and sealing steps must be performed at the same temperature, it is very difficult to select the base material. When a resin other than PVC is used as the base material, the moldability is good, but the heat resistance at the time of sealing is insufficient and the phenomenon that the film is fused to the hot plate of the seal, that is, the problem of the hot plate being removed, Although the heat resistance at the time of sealing is good, there is a problem that the moldability is deteriorated.

[0004]

DISCLOSURE OF THE INVENTION The present invention has found a composite film capable of solving the above problems, and its gist is to provide a polybutylene terephthalate resin layer and an amorphous polyester resin layer at least from the outer layer. The cohesive failure layer and the seal layer are laminated in this order, and the polybutylene terephthalate resin layer has a thickness of 1 to 20% of the total thickness, and the amorphous polyester resin layer has a thickness of 30 to 90% of the total. It is in a composite film.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The outermost polybutylene terephthalate resin (hereinafter "PB
The thickness of the layer (abbreviated as "T") needs to be 1 to 20% of the whole, but since PBT is arranged to prevent hot plate removal, it suffices if the surface layer has a slight thickness. The thickness may be within a range that does not impair the moldability, and preferably PB
The thickness of the T layer is 1 to 10% of the whole, more preferably 1 to 5
% Range. If it is less than 1%, there is a problem in the stability of the hot plate removal prevention effect, and if it exceeds 20%, there is a large possibility that the moldability is impaired.

The polyester resin used for the amorphous polyester resin layer adjacent to the PBT layer is not limited to homotype and copolymer type resins, but the moldability is required and the crystallinity must be suppressed as low as possible. Particularly in the case of a homotype resin having a high crystallinity, it is necessary to rapidly cool the film after forming it into an amorphous state. Further, "PETG" manufactured by Eastman Chemical Co., which is a copolyester resin using terephthalic acid as an acid component and ethylene glycol and 1,4-cyclohexanedimethanol as an alcohol component, is amorphous and can be preferably used. Here, the thickness of the amorphous polyester resin layer is required to be 30 to 90% of the whole, because this is to cover the moldability of the outer layer PBT having poor moldability, and if it is less than 30%, There is a very high possibility that the property will be insufficient and the waist will also be low, which is not preferable. On the contrary, if it exceeds 80%, the thickness of the seal layer, the easy peel layer and the adhesive resin layer for adhering them becomes thin, and the originally required performances such as sealing property, easy peel property and interlayer adhesive strength cannot be imparted, which is preferable. Absent.
Considering the moldability, it is more preferably in the range of 50 to 90%, and further, it is preferable to set the thickness of the amorphous polyester resin layer to 5 times or more the thickness of the polybutylene terephthalate resin layer.

The seal layer has an MI of 5 to 30 (JIS K
7210 Test temperature: 190 ° C, test load: 2.16k
A low density polyethylene of gf (21.18N) can be preferably used. This is due to the mechanism of the suppository packaging machine, a phenomenon in which the molding part is slightly fused during preheating of the molding is observed, and when the fused part is molded, the force of molding prevents the film from delaminating. This is because the peel strength of the fused portion of the low-density polyethylene polymerized by the high-pressure method having poor hot tack property is low and excellent. Further, it is preferable that MI is in the range of 5 to 30, more preferably 10 to 25 because the fluidity at the time of melting is high and the fused portion is easily peeled off. When the MI is less than 5, peeling of the fusion-bonded portion is poor and there is a risk of delamination of the film. Further, the breaking strength of the film is increased, the film is less likely to be broken at the time of opening due to the breakage of the cohesive failure layer, and the film residual phenomenon is likely to occur. On the other hand, when the MI exceeds 30, it is difficult to form a film. The thickness is desired to be 1 to 15 μm, more preferably 1 to 10 μm.
This is because when the thickness exceeds 5 μm, the breaking strength of the film becomes strong as described above, the film is less likely to break at the time of opening due to the breakage of the cohesive failure layer, and the film residual phenomenon is likely to occur.

The resin used in the cohesive failure layer is not particularly limited, and is a mixture of ethylene-vinyl acetate copolymer (EVA) and polypropylene (PP), linear low density polyethylene (LL) and polybutene-1 (PB). It is possible to use a combination of commonly known resins such as a mixture of -1) and a mixture of an ionomer and PP. Here, the thickness of the cohesive failure layer is 1
˜15 μm, more preferably 1 to 10 μm. This is because it is necessary to reduce the thickness of the cohesive failure layer as much as possible in order to suppress stringing during cohesive failure. However, if the thickness is 1 μm or less, the easy peel layer becomes too thin, which may cause a problem in stability of the easy peel strength. On the other hand, if it exceeds 15 μm, a large amount of stringing occurs, and the problem of deteriorating the peeled appearance tends to occur.

The film forming method of the film of the present invention is not particularly limited, but a coextrusion method capable of setting the thickness of each layer to an optimum thickness is most preferable. Further, in the case of a suppository packaging film, titanium oxide or the like can be added to the amorphous polyester resin layer to give a coloring such as white. The suppository film is generally formed by molding, sealing and packaging the same film, but the film of the present invention can be used in the same manner. However, by using a completely seal type film (eg PBT / amorphous polyester resin / AD / LDPE) on one side rather than the case where easy peel is applied on both sides,
Easy peeling is performed in a single layer, so peeling is stable,
It is possible to obtain a stable easy peeling property in which no film residue is generated.

In order to impart an oxygen barrier property, an oxygen barrier layer such as saponified ethylene-vinyl acetate copolymer may be arranged in the layer structure.

[0011]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. The films of Examples 1 and 2 and Comparative Examples 1 to 6 were formed by a coextrusion method and / or an extrusion laminating method and evaluated.

(Example 1) [Layer constitution] PBT / PETG / AD / LL + PP / LDPE (5 μm / 105 μm / 10 μm / 5 μm / 5 μm) PBT: Novadur 5010 (manufactured by Mitsubishi Engineering Plastics Co., Ltd.) PETG: Easter PETG6763 (manufactured by Eastman Chemical Co., Ltd.) AD: Admer SF731 (manufactured by Mitsui Chemicals, Inc.) LL + PP: LL: Novatec LL UF240 (manufactured by Nippon Polychem Co., Ltd.) PP: Novatec PP FW3E (Japan Polychem Co., Ltd.) )
LDPE: Novatec LD LC720 (manufactured by Nippon Polychem Co., Ltd.) A raw material resin having the above composition was used to form a film by a T-die coextrusion method.

(Example 2) [Layer structure] PBT / PETG / AD / EVOH / AD / EVA + P
P / LDPE (5μm / 84μm / 7μm / 15μm / 7μm / 7μ
m / 5 μm) EVOH: Soarnol AT4403 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) EVA + PP: EVA: Novatec EVA LV350 (manufactured by Nippon Polychem Co., Ltd.) PP: Novatec PP FW3E (Nippon Polychem Co., Ltd.)
Other products are the same as in Example 1. A film was formed by the T-die coextrusion method using the raw material resin having the above composition.

Comparative Example 1 [Layer Structure] PETG / AD / LL + PP / LDPE (110 μm / 10 μm / 5 μm / 5 μm) The same raw material as in Example 1 was used to form a film by the T-die coextrusion method.

Comparative Example 2 [Layer Structure] PBT / AD / LL + PB-1 / LDPE (110 μm / 10 μm / 5 μm / 5 μm) The same raw material as in Example 1 was used to form a film by the T-die coextrusion method.

Comparative Example 3 [Layer Constitution] PBT / PETG // LDPE (5 μm / 95 μm // 30 μm) A coextruded sheet of PBT / PETG was formed using the same raw material as in Example 1, and then LDPE was formed. Was extrusion laminated. The PETG and LDPE layers are separated and opened.

(Comparative Example 4) [Layer Structure] PBT / PETG / AD / LL + PP / LDPE (30 μm / 80 μm / 10 μm / 5 μm / 5 μm
) The same raw material as in Example 1 was used to form a film by the T-die coextrusion method.

(Comparative Example 5) [Layer constitution] PBT / PETG / AD / LDPE / LL + PP
/ LDPE (20 μm / 35 μm / 10 μm / 45 μm / 10
μm / 10 μm) The same raw material as in Example 1 was used to form a film by T-die coextrusion method.

Comparative Example 6 [Layer Structure] PBT / PETG / AD / LL + PP / LDPE (2 μm / 120 μm / 3 μm / 2 μm / 2 μm) The same raw material as in Example 1 was used to form a film by T-die coextrusion method. did.

<Evaluation Method> Using each of the above films, suppositories were packaged by an ordinary suppository packaging machine, and the performance was evaluated. (The film used the same film on both sides)

Moldability: Whether or not molding according to the mold was possible was evaluated, and those that could be molded according to the mold were evaluated as ◯. -Sealability: When the hot plate was peeled off during sealing, it was evaluated whether or not the phenomenon occurred. -Easy peeling property: The peeling state at the time of opening was observed, and there were no problems such as film residue and stringing, and those that could be peeled off neatly were rated as ◯. The evaluation results are shown in Table 1.

[0022]

[Table 1]

It can be seen from Table 1 that Examples 1 and 2 using the composite film of the present invention are excellent in both performances. On the other hand, it is understood that Comparative Examples 1 to 6 are inferior to any of the performances and are inconvenient for suppository packaging.

[0024]

EFFECTS OF THE INVENTION According to the present invention, a composite film having good moldability, sealing property and easy peeling property, which can be suitably used for suppository packaging, can be obtained.

Continued front page    F term (reference) 3E086 AB01 BA04 BA15 BA24 BB51                       BB90 CA28                 4F100 AK06C AK07D AK41B AK42A                       AK68D AL05D AR00D BA04                       BA07 BA10A BA10C GB15                       GB66 JA12B JA20A JA20B                       JK01D JL01 JL12C JL14                       YY00A YY00B YY00C

Claims (4)

[Claims] 1. A polybutylene terephthalate resin layer, an amorphous polyester resin layer, a cohesive failure layer, and a seal layer are laminated in this order from at least the outer layer, and the thickness of the polybutylene terephthalate resin layer is 1 to 20% of the whole, and the amorphous The composite film, wherein the thickness of the conductive polyester resin layer is 30 to 90% of the whole. 2. The seal layer has a melt index (MI).
It is a low-density polyethylene resin of 5-30, The composite film of Claim 1 characterized by the above-mentioned. 3. The composite film according to claim 1, wherein the cohesive failure layer has a thickness of 1 to 15 μm and the sealing layer has a thickness of 1 to 15 μm. 4. The composite film according to claim 1, which is used for packaging suppositories.