Stock material or miscellaneous articles – Hollow or container type article – Polymer or resin containing
Patent
1994-10-04
1996-05-28
Page, Thurman K.
Stock material or miscellaneous articles
Hollow or container type article
Polymer or resin containing
428218, 428515, 424443, 424444, 424449, B29D 2200, B29D 2300, B32B 108, B65D 3002
Patent
active
055209750
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to medical multilayer films which are excellent in heat resistance, transparency, flexibility, impact resistance, easily peelable sealing properties, etc. and to medical containers formed of said films and having a plurality of chambers.
Such medical containers have a plurality of chambers for individually accommodating unstable medical preparations (liquid, powdery or solid preparations) which are likely to change with time when mixed together, and a weak seal portion (easily peelable seal portion) separating the chambers and easily openable when desired by peeling to mix the medical contents of the chambers.
The term "easily peelable sealing properties" as used herein refers to such properties of a film that the film is capable of selectively forming a strong seal portion which is substantially not openable by peeling or a weak seal portion (hereinafter referred to as the "easily peelable seal portion") which is easily openable by peeling, one of the seal portions being formable by altering the fusing temperature for heat sealing.
BACKGROUND ART
Films for medical containers are generally formed by polyethylene or polypropylene which has high chemical stability to acids, alkalis, salts, etc. Also known as films for use in forming such medical containers having a plurality-of-chambers-are single-layer or two-layer films having a resin layer which is prepared from a molten mixture of alpha-polyolefin resins, such as polyethylene and polypropylene, which are different in compatibility.
For example, Unexamined Japanese Patent Publication No. 4671/1990 discloses a single-layer film of resin mixture of two components, i.e., a linear low-density polyethylene and polypropylene, or a single-layer film of resin mixture of three components, i.e., a linear low-density polyethylene, polypropylene and ethylene-propylene copolymer. A two-layer film is also disclosed which comprises an outer layer of linear low-density polyethylene, and an inner layer of resin mixture of linear low-density polyethylene and polypropylene. In the resin mixtures mentioned, polypropylene has the highest melting point and is used mainly to ensure easily peelable sealing properties.
However, the single-layer film of two-component resin mixture contains in the single-layer forming resin a large amount of polypropylene which is lower than polyethylene in transparency, flexibility and impact resistance, so that the container prepared from this film is low in usefulness in respect of transparency, flexibility and impact resistance.
Further, the problem of nonuniformity of the components is encountered with the single-layer film of three-component resin mixture when the mixture is made into the film. Stated more specifically, the ethylene-propylene copolymer which is amorphous or low in crystallinity and lowest in melting point is greater than the other two components and especially much greater than polypropylene in fluidity, with the result that the resin components of the film are likely to be present unevenly, It is therefore difficult for the film to effectively exhibit transparency, flexibility and impact resistance which are the outstanding characteristics of the ethylene-propylene copolymer resin. Moreover, it is difficult to uniformly disperse polypropylene in polyethylene and to form a film which has excellent easily peelable sealing properties, that is, which contains polypropylene as uniformly dispersed therein. The single-layer film wherein the component resins differ greatly in melting point encounter another problem when heat sealed. When the component resin of the highest melting point (polypropylene) starts to melt, the component resin of the lowest melting point (ethylene-propylene copolymer) has been excessively melted to flow in the form of a liquid, greatly reducing the thickness of the film to be heat sealed. Accordingly, the film is not heat sealable properly to give the desired strength to containers.
On the other hand, the two-layer film disclosed in the above-mentioned publ
REFERENCES:
patent: 4407874 (1983-10-01), Gehrke
patent: 4528220 (1985-07-01), Hwo
patent: 4578316 (1986-03-01), Clauson et al.
patent: 4643928 (1987-02-01), Kimura et al.
patent: 4775562 (1988-10-01), Shishido et al.
patent: 4891253 (1990-01-01), Mueller
patent: 4929479 (1990-05-01), Shishido et al.
patent: 4994324 (1991-02-01), Bose et al.
patent: 5267646 (1993-12-01), Inoue et al.
Inoue Fujio
Izumi Masamitsu
Kashiyama Shigetoshi
Benston, Jr. William E.
Otsuka Pharmaceutical Factory Inc.
Page Thurman K.
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