Title of Invention

A PROCESS FOR MANUFACTURING BOTH SIDE RELEASE COATED POLYIMIDE FILM FOR ELECTRICAL INSULATION

Abstract

A process for manufacturing "Both Sides Release Coated Polyimide Film for Electrical Insulation" comprises of the following steps: (i) coating one side of polyimide film with release coating material such as silicones, chrome complexes, organic carbamates, fluorocarbon or flucosilicones of required depositions preferably of 0.20 to 0.60 gms. per sq. meter, using conventional coating methods and equipment, followed by drying in conventional equipments to get one side release coated polyimide film. (ii) coating other side of the said release coated polyimide film with release coating materials such as silicones, chrome complexes, organic carbamates, fluorocarbon or flurosilicones of required depositions preferably of 0.20 to 0.60 gms per sq. meter, using conventional coating methods and equipment, followed by drying in conventional equipments to get both sides release coated polyimide film.

Full Text

FORM 2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION (See Section 10) **BOTH SIDES RELEASE COATED POLYIMIDE FILM FOR ELECTRICAL INSULATION" PRS Solutions Private Limited,^ Company incorporated under the Companies Act, 1956 and having its office at 63, Bombay Samachar Marg, Mumbai - 400 001 Maharashtra State, India,! The following specification particularly describes the nature of this invention and the manner in which it is to be performed 2-11-2004 FIELD OF THE INVENTION : This invention relates to "Both Sides Release Coated Polyimide Film for Electrical Insulation" and the process of manufacturing the same. It consists of polyimide film coated with a release coating material on both sides of polymide film which helps in the ease of application. DESCRIPTION OF THE PRIOR ART : Non adhesive polyimide film or sodium treated Teflon tape is used to cover the conductors and varnishing is done. Post varnishing this non adhesive polyimide film or sodium treated Teflon tape is unwrapped and disposed off. Problems faced in this technique (a) Non-uniform coating/varnishing of the conductors. (b) wastage of varnish. (c) Rough finish of the conductor. The other conventional methods used include covering the conductors with polyester sheets or polyethene sheets. None of the above techniques provide uniform/smooth finish of the conductor. - INVENTION : During the process of bundling of the conductors, An Insulating Tape Of Both Sides Release Coated Polyimide Film ensures that the varnish does not stick to the film as well as it does not fall out thereby avoiding wastage. It is used as a sacrificing film during the formation of copper bars. These copper bars are made by binding together individual strips of copper. This film is used to ensure that during the varnishing process the varnish is used maximum to bond the copper strips and not wasted away. The film is sacrificed after the copper bars are made post curing after vanishing. 2 SUMMARY OF THE INVENTION : "Both Sides Release Coated Polyimide Film for Electrical Insulation" comprises of coating, with formulated release material, on both sides of Polyimide film in order to ease out process of applications. Polydialkyl silicone is the main silicone release material in this invention. The solid content of this material is around 35-40 %. The second component is the catalyst which is either based on platinum or tin. The third component of this solution is the accelerator. Polydialkyl silicone release coating solution is diluted in aromatic solvent in the ratio 1:15 to 1:200 (Volume: Volume) depending on the type of release coating required. It is then mixed 0.1 to 0.5 % catalyst solution with continuous stirring. The third component is accelerator to added to the solution before coating. Coating of this solution is carried out on polymide film using gravure coating techniques on one side which is then dried amd-cured-by conventional drying method. The one side coated material is conditioned for minimum three days before coating on the other side. After conditioning, the one side coated polymide film is coated with release coating on the other side using gravure coating techniques which "is then dried by conventional drying methods. Following are the steps involved in the manufacture of An Insulating Tape Of Both Sides Release Coated Polyimide Film for Electrical Insulation. DESCRIPTION OF THE PREFERRED EMBODIMENTS : lllllllllllllllllllllllllllllllllllllllllllflllllllllllllllllll -* Release Coating lllllllllllllllllllllllllllllllllllllllllllllllllllllllllllllll -> Polyimide Film IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIHII -» Release Coating 3 Polyimide film used in this invention is of different thickness in ranging form 0.025 mm to 0.075 mm thickness. The release coating is developed based on silicones, chrome complexes, organic carbamates, fluorocarbon or fluorosilicones. It is formulated to give the control release. The deposition of the release coating in the range of 0.20-0.6 gms per sq. meter on each side. The temperature required for this coating is 170° C. 4 WE CLAIM: 1. A process for manufacturing "Both Sides Release Coated Polyimide Film for Electrical Insulation" comprises of the following steps: (i) coating one side of polyimide film with release coating material such as silicones, chrome complexes, organic carbamates, fluorocarbon or flucosilicones of required depositions preferably of 0.20 to 0.60 gms. per sq. meter, using conventional coating methods and equipment, followed by drying in conventional equipments to get one side release coated polyimide film. (ii) coating other side of the said release coated polyimide film with release coating materials such as silicones, chrome complexes, organic carbamates, fluorocarbon or flurosilicones of required depositions preferably of 0.20 to 0.60 gms per sq. meter, using conventional coating methods and equipment, followed by drying in conventional equipments to get both sides release coated polyimide film. 2. A process for manufacturing "Both Sides Release Coated Polyimide Film for Electrical Insulation" as claimed in Claim 1, wherein the solution of silicone release materials consists of Polydialkyl, silicone, catalyst and the accelerator. 3. A process for manufacturing "Both Sides Release Coated Polyimide Film for Electrical Insulation" as claimed in Claims 1 and 2, wherein the release coating compound is based on silicones, chrome complexes, organic carbamates, fluorocarbon or fluorosilicones. Dated this 11th day of January, 2003 (Bharaf S. Shah) Duly Constituted Attorney

Documents:

47-mum-2003-cancelled pages(02-11-2004).pdf

47-mum-2003-claims(granted)-(02-11-2004).doc

47-mum-2003-claims(granted)-(02-11-2004).pdf

47-mum-2003-correspondence(02-11-2004).pdf

47-mum-2003-correspondence(ipo)-(03-01-2006).pdf

47-mum-2003-form 1(14-01-2003).pdf

47-mum-2003-form 19(17-07-2003).pdf

47-mum-2003-form 2(granted)-(02-11-2004).doc

47-mum-2003-form 2(granted)-(02-11-2004).pdf

47-mum-2003-form 26(14-01-2003).pdf

47-mum-2003-form 3(14-01-2003).pdf

47-mum-2003-form 5(14-01-2003).pdf