Title of Invention	METALLIZED PAPER BASED LIDDING MATERIAL FOR BLISTER PACKAGING
Abstract	The present invention provides a high temperature and pressure resistant multilayered lidding material for blister packaging.

Full Text

FORM-2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 PROVISIONAL Specification (See section 10 and rule 13) METALLIZED PAPER BASED LIDDING MATERIAL FOR BLISTER PACKAGING BILCARE LIMTIED, an Indian Company of 1028, Shiroli, Rajgurunagar (Taluka Khed), Pune 411 505, Maharashtra, India THE FOLLOWING SPEC IFICATION DESCRIBES THE INVENTION. The present invention generally relates packaging materials. Particularly, the present invention relates to novel, cheaper lidding materials suitable for use in packaging of articles. Blister packing is a common form of packaging used for a wide variety of products such as food articles, pharmaceutical preparations, toys etc. blister packing is safe and easy to use and can allow the consumer to see the packaged contents without opening the pack when at least one surface of said blister pack is made of a transparent material such as PVC plastics. Commonly available blister pack has two surfaces. One surface has cavities at predetermined places to hold the desired article and the other surface acts as a lid. During the process of packaging, the article to be packed is put into the cavity and the lidding material in the form of, for example a foil, is attached or fixed over the open surface of the cavity. To take the article out of the cavity, the lidding material may be burst opened or torn in a suitable fashion to release the article off. Depending on the specific requirements, a variety of modification such a conventional blister packing can be made, especially with respect to the materials and the releasing mechanism used to arrive at a suitable blister pack. The most commonly used materials for forming blister are polymer based, such as PVC (polyvinyl chloride) plastics. Depending on the material used and its thickness, such blisters may be transparent, semi-transparent or opaque. Often, paper or aluminium foils are used as lidding materials. One side of the lidding material is also used for printing product information and usage instructions. The lidding material is fixed to the surface having cavities through heat sealing mechanism or just by application of adhesive. Completely paper-based lidding materials are suitable for articles that are insensitive to moisture or surrounding environment, such as plastic toys. However, purely paper based lidding materials do not have enough strength and barrier properties required for packaging of articles that are sensitive to environment such as food items and pharmaceutical preparations. However, these materials has serious disadvantage that these material does not provide optimum barrier towards moisture or gas which is the one of the most essential requirement of the lidding materials used in packaging of pharmaceutical products. Such articles are often packed in blisters that use aluminium foil as lidding materials due to its higher barrier properties of the aluminium foil. Economic and environmental reasons require alternative lidding materials that have strength and optimum barrier properties comparable to aluminium foils, but are cheaper than currently used aluminium foils and can be easily recyclable also. The inventors of the present invention have comprehensively and successfully investigated the possibility of developing such a highly desired cheaper lidding material and have unexpectedly developed a paper based lidding materials for blister pack having excellent strength, barrier properties and look like aluminium foil which provide a opaque surface for printing and are cheaper than aluminium foils. Accordingly, this invention provides a paper based metlallized lidding material for blister packaging comprising a paper layer having two surfaces of which one surface is facing opposite to the blister cavity and other one facing to the blister cavity which get sealed to the blister cavity. The metallized layer is coated on either side of the paper by a method of transfer metallization process or direct vacuum metallization process. An optional barrier coat and sealing coat is applied on the surface facing the blister cavity. Further, the metallized paper optionally coated with lacquer layer for obtaining printable surface. Thus, lidding material according to this invention comprises a paper layer sandwiched between, one side by a barrier coat and sealing coat, and on other side a metal layer and optional lacquer coat suitable for printing or metallized layer is present on the surface facing blister cavity and the resulting lidding paper layer is sandwiched between a printing lacquer layer and a metallized layer coating and optional barrier layer, sealing layer. Brief Description of accompanying drawing: The invention will be described in detail with reference to a preferred embodiment. Reference to this embodiment does not limit to the scope of this invention. In the accompanying drawing: Figure 1 illustrates a partial sectional view of one of the several embodiments of a paper-based lidding material according to this invention. The paper selected on the basis of desired packaging requirements. A normal paper can also be used, if desired. However, such fibrous paper may have higher absorption properties and take more amounts of coating material to achieve uniform coating. To overcome these absorption related problem, method is to pre-treat the paper (for example, say waxing) to saturate and thereby lower the absorption. A preferable example of paper that can be used to prepare paper-based lidding material according to this invention is Glassine paper. A Glassine paper is pure cellulose paper manufactured from 100% (fresh) cellulose and transparency and grease resistance of such paper is achieved by a special mechanical treatment and not by chemical additives. The Glassine paper thus does not contain chemicals or other materials and has very good strength and low absorption ability. A range of Glassine paper is available commercially, depending on the processing method and other properties such as colours. The glassine paper available may be used as it is or may be treated if desired. Although the absorption ability of Glassine paper is low but not enough sufficient to provide desired barrier property to the packaged pharmaceutical product. Therefore, it has to be further treated such as applying barrier coating to improve the barrier property. However, still further the barrier property of the paper can be improved by applying metal coating on the either surfaces of the paper . The metallization of the Glassine paper can be achieved by the process called as transfer metallization process or by direct vacuum metallization process. Further, metallized paper based lidding material provides a clear opaque surface for printing which is visible from only one side. It is desired that Glassine paper used to have purity of at least 90%. The thickness of the Glassine paper may vary depending on the specific requirement. However, Glassine paper having thickness of about 150 gsm or below are preferred. One surface of the paper will face the cavity (herein after referred to as inner surface) where as the other surface will act as an outer surface (facing away from the cavity) and will available for printing purpose. According to present invention, one of the surfaces of the glassine paper was metallized by transfer metallization process or direct vacuum metallization process which imparts required barrier property and enhances the aesthetics of the lidding material and will provide enhanced opacity which will help for printing of the desired information. For metallization purpose one can used metals like aluminium, gold, silver, copper, platinum, preferably aluminium. The thickness of the metallization can be vary according to achieve the desired barrier property as the outer surface of the lidding paper is exposed to environment which acts as barrier surface for the gases and water vapour. Thus applying a protective metal coat will certainly act as better barrier surface against the above said gases and water vapours than the paper alone or paper with barrier coat. Further, an optional printing coat can be applied on outer surface of the metallized paper lidding material for providing a printing surface if desired. The metallized side of the glassine paper or side opposite to the metallized layer of glassine paper i.e. surface facing to the cavity, a sealing coat is applied. The sealing coat contains materials capable of attaching or fixing itself with the sheet baring cavities. Simplest examples of sealing coats include adhesive coats or heat sealing coats.. A variety of sealing coats are available commercially that can be applied to the lidding paper for sealing purpose. Optionally, an additional barrier coat can be applied prior to applying sealing coat to the inner surface of the Glassine paper. The optional barrier coat further imparts to the barrier property of the lidding material. A wide variety of the barrier coats available commercially and can advantageously be used such as Poly Vinyl dichloride (PVdC). The thickness of the barrier coat can very according to the coating used and the barrier property desired. Further, additional layer of barrier coats can be applied which will acts as heat sealing coat itself and provide additional barrier property to the lidding material. The thickness of the paper, metallization layer, barrier coat and sealing coat can vary depending upon the specific properties desired. Any of the above coating operations can be accomplished using known techniques and without applying any pre-treatments such as application of primer. However, one can include such pretreatment or post treatment operations if desired. Similarly, one may advantageously use post treatments such as heating, annealing or curing if desired, depending on the specific needs. The lidding material according to this invention has excellent strength and barrier properties and adequate opacity and can be used for packaging several materials. However, the lidding materials according to present invention are particularly useful in the packaging of environment sensitive materials such as food items, pharmaceutical products, clinical materials and light sensitive materials. Representative Example: A Glassine paper (50 gsm) was first coated with aluminium by transfer metallization procedure to achieve coating thickness of around 0.03 microns. A barrier coat of polyvinyl dichloride of thickness between 30-40 gsm and a sealing coat of thickness between 4 to 6 gsm of locally available heat sealing coat was applied to the side opposite to the metallized surface with the help of gravure coating process and a printing lacquer coat of pearlized silver based lacquer was applied on the metallized surface of thickness between 1.5+ 0.5 gsm. The resulting material after drying has following properties: 1. Average WVTR: 3.0 g/m2/day 2. Push Through Force: 2.5 kg 3. Toxicity (USP): Non Toxic While considerable emphasis has been placed herein on the specific structure of the preferred embodiment, it will be appreciated that many alterations can be made and many modifications can be made in the preferred embodiment without departing from the principle of the invention. These and other modifications in the preferred embodiment as well as other embodiments of the present invention will be apparent to those skilled in the art from the discloser herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

Documents:

595-MUM-2008-ABSTRACT(13-9-2013).pdf

595-MUM-2008-ABSTRACT(24-3-2009).pdf

595-MUM-2008-CLAIMS(24-3-2009).pdf

595-MUM-2008-CLAIMS(AMENDED)-(13-9-2013).pdf

595-MUM-2008-CLAIMS(MARKED COPY)-(13-9-2013).pdf

595-MUM-2008-CORRESPONDENCE(14-9-2010).pdf

595-MUM-2008-CORRESPONDENCE(24-3-2009).pdf

595-MUM-2008-CORRESPONDENCE(8-4-2008).pdf

595-mum-2008-correspondence-received.pdf

595-mum-2008-description (provisional).pdf

595-MUM-2008-DESCRIPTION(COMPLETE)-(24-3-2009).pdf

595-MUM-2008-DRAWING(24-3-2008).pdf

595-MUM-2008-DRAWING(24-3-2009).pdf

595-mum-2008-drawings.pdf

595-MUM-2008-FORM 1(8-4-2008).pdf

595-MUM-2008-FORM 18(14-9-2010).pdf

595-mum-2008-form 2(24-3-2009).pdf

595-MUM-2008-FORM 2(TITLE PAGE)-(24-3-2009).pdf

595-MUM-2008-FORM 2(TITLE PAGE)-(PROVISIONAL)-(24-3-2008).pdf

595-MUM-2008-FORM 26(13-9-2013).pdf

595-MUM-2008-FORM 5(24-3-2009).pdf

595-mum-2008-form-1.pdf

595-mum-2008-form-2.doc

595-mum-2008-form-2.pdf

595-mum-2008-form-3.pdf

595-MUM-2008-REPLY TO EXAMINATION REPORT(13-9-2013).pdf

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