Bottles and jars – Closures – Stopper type
Reexamination Certificate
1996-06-19
2001-09-11
Vidovich, Gregory M. (Department: 3727)
Bottles and jars
Closures
Stopper type
C215S247000, C220S801000
Reexamination Certificate
active
06286699
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a novel structure of laminated rubber stopper and more particularly, it is concerned with a laminated rubber stopper used for sealing containers, instruments, etc. for medicaments and medical treatments.
2. Description of the Prior Art
As a stopper material of a container, instrument, etc. for medicaments and medical treatments, it is desired to have various properties such as heat resistance, compression resistance test, softness, chemical inertness and low permeability of gases or water. In particular, rubbers are excellent in sealing property and natural rubbers have been used for a long time while synthetic rubbers have often been used more recently for example, isobutylene-isoprene co-polymer rubbers (IIR) having been recommended from a sanitary point of view. However, these materials have such problems as contamination in that curing agents, compounding agents, etc. contained in rubbers are dissolved in medicaments held in containers, the contents in a container are adsorbed on the rubber surface, fine grains occur from the rubber material during the production process or storage, etc.
In order to solve these problems, a laminated rubber stopper has been proposed in which a part of the rubber stopper, to be contacted with a contents in a container, or the whole surface of a leg part is laminated with a chemically inert resin such as fluoro resins. The contamination due to contact of a liquid medicament, etc., with a rubber surface can be prevented by the laminated rubber stopper, but in fact, such a proposal cannot be applied to preparation of drugs since there arise new problems that the leg part of the stopper laminated with a fluoro resin, etc. is inferior in sealing property of the mouth part of a vial to that having a rubber surface exposed and preparation of a thin laminated layer capable of maintaining rubber elasticity is difficult.
As shown in
FIG. 5
, on the other hand, the inventor has proposed a laminated rubber stopper capable of preventing the contamination by forming a laminated layer of a fluoro resin film on a leg part, while maintaining the tightness or sealing property with a container by retaining an exposed rubber surface on an area from the lower surface of a flange part in the top part of a rubber stopper body to the base of the leg part (Japanese Patent Publication No. 64062/1993), and a production process for realizing this structure (Japanese Patent Publication No. 50386/1993).
The above described laminated rubber stopper the inventor has proposed is an excellent rubber stopper capable of realizing the desired effects, but this cannot be said to be suitable for application to a container for a very unstable and expensive medicament, for example, biotechnological preparations, anticancer drugs, etc., which have lately been developed, since a rubber surface is contacted with a lip part of a container although it is not contacted with a liquid medicament. For the production thereof, a complicated process is required the stopper, using upper and lower metallic molds, thus increasing the production cost.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a laminated rubber stopper with a new structure or shape, whereby the disadvantages of the prior art can be overcome.
It is another object of the present invention to provide a laminated rubber stopper having a new structure, capable of being produced in a simple process with a reduced production cost and being so excellent in tightness, sealing property and sanitary property that the rubber stopper can be used in a storage container for unstable and expensive medicaments sensitive to the outside environment, with maintaining its good quality for a long time.
These objects can be attained by a laminated rubber stopper comprising a top part having a flange part and a leg part provided under the top part of the rubber stopper and to be inserted into the mouth part of a vial, at least a surface thereof to be contacted with the contents in the vial being laminated with a fluoro resin film, in which the lower surface of the flange part has an annular concavity with a cross-section of an arc from the periphery of the flange to the neck part (connection part with the leg part).
REFERENCES:
patent: 1721210 (1929-07-01), Dalley
patent: 2573637 (1951-10-01), Bender
patent: 3842790 (1974-10-01), Clark
patent: 4441621 (1984-04-01), Matukura et al.
patent: 4554125 (1985-11-01), Knapp
patent: 5288560 (1994-02-01), Sudo et al.
patent: 1012842 (1957-07-01), None
patent: 1039390 (1958-09-01), None
patent: 0294127 (1988-12-01), None
patent: 0324554 (1989-07-01), None
patent: 738546 (1955-10-01), None
patent: 58-29939 (1983-02-01), None
Daikyo Seiko Ltd.
Eloshway Niki M.
Vidovich Gregory M.
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Laminated rubber stopper does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Laminated rubber stopper, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laminated rubber stopper will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2518546