Stock material or miscellaneous articles – Hollow or container type article – Nonself-supporting tubular film or bag
Patent
1998-04-23
1999-10-05
McCamish, Marion
Stock material or miscellaneous articles
Hollow or container type article
Nonself-supporting tubular film or bag
428 353, 428 354, 428 355, 428 366, 428 357, 428 358, 428 367, 428 368, 428 369, 428 3691, 428 3692, 428355EN, B29D 2200
Patent
active
059620943
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a closure giving a tight mechanical seal and preferably made from metal or plastic, with an insert on its inner side as a sealing element for containers, in particular for bottles and glassware.
Container closures must be suitable for simple but nevertheless reliable application to seal the container tightly, no requirement for after-treatment usually being permitted, and the dimensions of the container aperture, as well as the condition in which it has been maintained and its roughness (for example in the case of returnable bottles) may differ greatly. It has therefore long been known that container closures, such as crown caps, can be provided on their inner side facing the container with a resilient sealing element, which, when the closure is applied, is compressed between this and the container and ensures that the seal is tight.
Whereas in earlier times the inserts for crown caps and for bottle screw-closures were produced predominantly from compressed cork, which, if desired, had also been coated with a thin film of plastic or aluminum, for a relatively long time now the sealing element has been produced entirely from synthetic polymer compound. However, suitable polymer compounds for this are only those which are sufficiently permanent and resistant and at the same time have the required resilience.
The material mainly used for this in industry is PVC: polyethylene and mixtures of these materials with vinyl acetate and/or vinyl acetate-ethylene copolymers have also been used.
The production of container closures using such polymer compounds is described, for example, in DE-B-20 33 064 and DE-A-30 21 488.
However, these known polymer compounds still have considerable disadvantages. The use of PVC or of other halogen-containing plastics is giving ever greater difficulties in disposing of the used container closures which find their way into household waste, and in rendering these non-hazardous. The usual incineration of household waste produces acidic gases from halogenated plastics, and the release of these into the environment is damaging. The additions of low-molecular-weight plasticizers (for example phthalates) which are unavoidable for adjustment to achieve the necessary sealing properties are also not free from health hazards, since these plasticizers are to some extent released again from the PVC and can find their way into the human body via the foodstuffs or other consumable items present in the container. For this reason, there is an upper limit placed by appropriate regulations on the proportion of plasticizer in such polymer materials.
The polyethylenes which have hitherto likewise been used have not proven successful as sealing material in particular because account has to be taken of variations in temperature and of damaged container openings. An additional reason for the non-usability of polyethylene was that the tightness of its seal was regarded as inadequate for CO.sub.2 -containing drinks.
It is an object of the present invention, therefore, to provide a closure giving a tight mechanical seal and preferably made from metal or plastic, with an insert on its inner side as a sealing element for containers, in particular for bottles and glassware, which insert ensures the necessary tightness of sealing, contains no damaging substances, in particular no halogen-containing constituents and no low-molecular-weight ester-group-containing plasticizers. In addition, the insert is to be able to withstand the conditions to which a usual container closure is exposed, in particular pasteurization.
This object is achieved if the insert is composed of at least one polyolefin which can be prepared using catalysts selected from the class consisting of the metallocenes.
The insert according to the invention is preferably composed of from 85 to 15% by weight of at least one polyolefin prepared using catalysts selected from the class consisting of the metallocenes, from 15 to 35% by weight of at least one polypropylene copolymer, from 0 to 25% by weight of at least one
REFERENCES:
patent: 4807772 (1989-02-01), Schloss
patent: 4984703 (1991-01-01), Burzynski
patent: 5026798 (1991-06-01), Canich
patent: 5055438 (1991-10-01), Canich
patent: 5133917 (1992-07-01), Jezic et al.
patent: 5695840 (1997-12-01), Mueller
patent: 5709915 (1998-01-01), Tomic et al.
patent: 5723507 (1998-03-01), Markovich et al.
patent: 5731053 (1998-03-01), Kuhn et al.
patent: 5749658 (1998-05-01), Kettner
patent: 5769772 (1998-06-01), Wiley
patent: 5827163 (1998-10-01), Kettner
patent: 5834079 (1998-11-01), Blinka et al.
patent: 5849418 (1998-12-01), Hoenig et al.
Nussen Peter
Osterkamp Doris
Chirgott Paul S.
McCamish Marion
PPG Industries Ohio Inc.
Singh Arti R.
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