Title of Invention

A METHOD OF MANUFACTURING NON - FOAMING, FLAME RETARDANT CASTOR OIL BASED POLYURETHANE RESIN COMPOSITION AND RESIN COMPOSITION MANUFACTURED THERE OF

Abstract

The present invention relates to a method of preparation of polyurethane resin mix. More particularly it relates to a method of preparation of polyurethane castor oil based, non-foaming, flame retardant flexible polyurethane resin for encapsulating plastic film capacitors, preventing capacitors from ingress of moisture, protecting capacitors from effect of flame produced but arcing of other components in vicinity in circuit as also arcing if any inside the capacitor affecting other components in circuit.

Full Text

FORM 2 THE PATENTS ACT, 1970 (39 FO 1970) & PATENT RULES, 2003 PROVISIONAL/COMPLETE SPECIFICATION (See section 10 and rule 13) 1. TITLE OF THE INVENTION : A method of manufacturing non-foaming, flame retardant castor oil based polyurethane resin composition and resin composition manufactured thereof. 2. APPLICANT(S) a. Name : CTR Manufacturing Industries Ltd.b. Nationality : Indian Companyc. Address : E 1, Chikalthana,d. AURANGARAD-431210, MAHARASHTRA, INDIA 3. PREAMBLE TO THE DESCRIPTION : The following specification particularly describes the the manner in which it is to be performed. invention and A method of manufacturing non-foaming, flame retardant castor oil based polyurethane resin composition and resin composition manufactured thereof. Field of invention: The present invention relates to polyurethane resin composition. Also it relates to a, non-foaming, flame retardant castor oil based polyurethane resin composition for encapsulating a plastic film capacitor for protecting the capacitor coil/winding from ingress of moisture and from the effect of arcing of other adjacent components in the vicinity on a populated printed circuit board and arcing if any inside the capacitor affecting other components in the circuit. Prior art: The main purpose of encapsulation in a plastic film capacitor is to protect the capacitor from mechanical shocks and environmental conditions. More specifically the purpose of the encapsulation is to protect capacitor coil from environmental hazards, to improve its capability to withstand moisture, heat and humidity and to improve insulation resistance. Currently a plastic film capacitor is manufactured by winding a metal deposited layer on a dielectric film, spraying both end faces with small droplets of molten metal that adhere along and make contact with metallization on the film, and soldering or welding the lead wire to this end spray for making a contact that can be used as a termination. A capacitor coil is placed in a casing or container and encapsulation material in liquid form is poured into the casing or container. Since hardner is already mixed into the liquid resin forming the encapsulating material, it solidifies. Currently epoxy resin with amine base or resins with phenol base are used for encapsulation. Use of these kinds of encapsulation material leads to following problems: i Filling material absorbs moisture and starts foaming and oozing out of encapsulation. ii The resistance power of capacitor to heat is not adequate. iii Tolerability to vibration is very less. iv Some times encapsulation material gets reacted chemically with the capacitor coil. v Voltage and insulation resistance started degrading after use. Objective of invention: The primary objective of the present invention is to provide a better encapsulation material for a plastic film capacitor which obviates all the deficiencies of the encapsulation material available in the prior art. Another objective of the present invention is to provide a castor oil based polyurethane resin composition for encapsulating the plastic film capacitor. Another objective of the present invention is to provide a castor oil based polyurethane resin composition which is flame retardant. Another objective of present invention is to provide a castor oil based polyurethane resin composition which avoids foaming and aggravation Another objective of present invention is to provide a castor oil based polyurethane resin composition which prevents oozing outwards by protecting against ingress of moisture. Another objective of present invention is to provide a castor oil based polyurethane resin composition which during process of filling for the encapsulation in a plastic film capacitor is in liquid form for a longer period before solidifying. Another objective of the present invention is to provide a castor oil based polyurethane resin composition which increases the life of capacitor and at the same time maintains its performance also. Summary of the Invention: For achieving the aforesaid objects of the invention, there is provided a method of manufacturing non-foaming, flame retardant castor oil based polyurethane resin composition, said resin composition being used as an encapsulation material in a plastic film capacitor, and said method comprising steps of: a. Adding 45 to 50 % by weight of castor oil and 25 to 30% by weight of aluminium trihydrate in powdered form; b. Mixing the said castor oil and aluminium trihydrate in a container using a motorized mixer to prepare a homogenous mixer; c. Adding 17 to 20% by weight of anhydrous Zeolite-A in a micro fine powdered form with pore diameter 4°A in to homogenous mixture obtained in step(b); d. Mixing anhydrous Ziolite-A and homogenous mixture of step (b) using a motorized mixture to get the homogenous mixture. According to one embodiment of the invention a method of manufacturing non-foaming, flame retardant castor oil based polyurethane resin composition further comprises step of mixing 8-10% by weight of hardener in the homogenous mixture obtained in step(d). According to another embodiment of the invention a non-foaming, flame retardant castor oil based polyurethane resin composition prepared by the above mentioned method of the present invention is provided. This resin composition comprises: a. 45 to 50% by weight of castor oil; b. 25 to 30% by weight of aluminium trihydrate in a fine powdered form; c. 17 to 20% by weight of anhydrous Zeolite-A in a micro fine powdered form with pore diameter of 4°A. According yet another aspect of the invention a non-foaming, flame retardant castor oil based polyurethane resin composition further comprises 8 to 10% by weight of hardener. According yet another aspect of the invention a non-foaming, flame retardant castor oil based polyurethane resin composition further comprises: a 46% by weight of castor oil; b. 27% by weight of aluminium trihydrate in a fine powdered form; c. 18% by weight of anhydrous Zeolite-A in a micro fine powdered form with pore diameter of 4°A, and d. 9% by weight of hardener. Also according further embodiment of the invention there is provided plastic film capacitor encapsulated by the non-foaming, flame retardant castor oil based polyurethane resin composition of the present invention. Detailed description of the present invention: The above, and the other objects, features and advantages of invention will become apparent from following description read in conjunction with the example. The present invention provides a castor oil based polyurethane resin composition which is non-foaming and flame retardant. This resin composition is used as an encapsulation material in plastic film capacitor. The castor oil based polyurethane resin composition is prepared by adding moisture free castor oil with aluminium trihydrate. The aluminum trihydrate is taken in powdered form. The aluminium trihydrate gives good flexibility in addition to flame retardency. The castor oil is taken in 45 to 50% by weight, while aluminium trihydrate is taken in 25 to 30% by weight. After adding, these both ingredients i.e castor oil and aluminium trihydrate are mixed in container using a motorized mixer to prepare a homogenous mixture. Then 17 to 20% by weight of anhydrous Zeolite-A in a micro fine powdered form with pore diameter of 4°A is added in to a homogenous mixture of castor oil and aluminium trihydrate. The anhydrous Zeolite-A prevents oozing out by protecting against ingress of moisture. After the addition of anhydrous Zeolite-A and homogenous mixture of castor oil and aluminium trihydrate are placed in a motorized mixer to get the homogenous mixture. And finally the castor based polyurethane resin having mixture of castor oil, aluminium trihydrate and anhydrous Zeolite-A in a particular proportion is obtained. The mixture is in liquid form. Then 8 to 10% by weight of hardener is added in the homogenous mixture of castor oil, aluminium trihydrate and anhydrous Zeolite-A to make it solidified. The hardener used is PAM grade and particularly MH330. Example: The following example will explain the aspect of the invention. The example must be taken only for an explanation purpose and it does not taken as restriction to the invention. Now we will see the process of manufacturing castor oil based polyurethane resin composition of the present invention by way of example. First take lOOgm of castor oil and 60 gm of aluminium trihydrate in a fine powdered form. Then add these both ingredients and put them in a conventional mixer. The mixer may be motorized or may be tun by any other means. Then mix both castor oil and aluminum trihydrate in the mixer for particular a period so that the homogenous mixture of both will obtain. Then add 40 gm of anhydrous Zeolite-A in a micro fine powdered form with pore diameter of 4°A in a homogenous mixture of castor oil and aluminum trihydrate. Again homogenous mixture and anhydrous Zeolite-A are mixed in a conventional mixer to make a homogenous mixture. Thus finally homogenous mixture is obtained which is the castor oil based polyurethane resin of the present invention. This obtained mixture is liquid form. Hence, the hardener in quantity of 20 gm is added in it to solidify the mixture. The hardener taken is of PAM grade. Then a test was taken on two plastic film capacitor; One encapsulated by the conventional encapsulation material as given in the prior art and the other is by the castor oil based polyurethane resin composition of the present invention. Then following observations were taken: SrNr. Parameters Capacitor encapsulated by encapsulation material as given in the prior art Capacitor encapsulated by the castor oil based polyurethane resin composition of the present invention 1 Voltage rating after use Reduced Not changed 2 Insulation resistance after use Reduced Not changed 3 Flame retardation capability Not present Present 4 Foam generation and oozing Present Not found 5 Tolerance to vibration Poor Better 6 Heat resistance capability Average Better 7 Moisture absorption Present Not found The above table clearly illustrates that how the encapsulation material prepared by the present invention is superior to the encapsulation material available in the prior art. Industrial Application: Plastic film capacitor of the present invention is useful in electronic as well as electrical industries. It is useful in various electronic and electrical circuits. The present invention is not limited to the above described embodiments, and various alterations, modifications, and / or alternative applications of the invention may be possible, if desired, without departing from the scope and spirit of the invention which can be read from the claims and the entire specification. All these possible alterations, modifications, and /or alternative applications of the invention are also intended to be within technical scope of the present invention. Claim: 1. A method of manufacturing non-foaming, flame retardant castor oil based polyurethane resin composition, said resin composition being used as an encapsulation material in plastic film capacitor, said method comprising steps of: a. Adding 45 to 50% by weight of castor oil with 25 to 30% by weight of aluminium trihydrate is in powdered form; b. Mixing said castor oil and aluminium trihydrate in a container using a motorized mixer to prepare a homogenous mixture; c. Adding 17 to 20% by weight of anhydrous Zeolite-A in a micro fine powdered form with pore diameter of 4°A in to a homogenous mixture obtained in step (b); d. Mixing anhydrous Zeolite-A and homogenous mixture obtained in step (b) using a motorized mixer to get the homogenous mixture. 2. A method of manufacturing non foaming, flame retardant castor oil based polyurethane resin composition as claimed in claim 1 which further comprises step of mixing 8 to 10% by weight of hardener in the homogenous mixture obtained in step (d). 3. A non-foaming, flame retardant castor oil based polyurethane resin composition, said resin being used as an encapsulation material in a plastic film capacitor, said resin composition comprises: a. 45 to 50% by weight of castor oil; b. 25 to 30% by weight of aluminium trihydrate in a fine powdered form; c. 17 to 20% by weight of anhydrous Zeolite-A in a micro fine powdered form with pore diameter of 4°A. 4. A non-foaming, flame retardant castor oil based polyurethane resin composition as claimed in claim 3 wherein said resin composition further comprises 8 to 10% by weight of hardener. 5. A non-foaming, flame retardant castor oil based polyurethane resin composition as claimed in claim 3 and 4 wherein said resin composition further comprises: a. 46% by weight of castor oil; b. 27% by weight of aluminum trihydrate in a fine powdered form; c. 18% by weight of anhydrous Zeolite-A in a micro fine powdered form with pore diameter of 4° A, and d. 9% by weight of hardener. 6. A plastic film capacitor encapsulated by the non-foaming, flame retardant castor oil based polyurethane resin composition as claimed in claim 3 and 5. 7. A non-foaming, flame retardant castor oil based polyurethane resin composition as herein before described and illustrated with reference to the examples. 8. A non-foaming, flame retardant castor oil based polyurethane resin composition as herein before described and illustrated with reference to the examples. Dated this on 16 day of April 2007 ABSTRACT The present invention relates to a method of preparation of polyurethane resin mix. More particularly it relates to a method of preparation of polyurethane castor oil based, non-foaming, flame retardant flexible polyurethane resin for encapsulating plastic film capacitors, preventing capacitors from ingress of moisture, protecting capacitors from effect of flame produced by arcing of other components in vicinity in circuit as also arcing if any inside the capacitor affecting other components in circuit.

Documents:

736-mum-2007-abstract(07-05-2008).doc

736-mum-2007-abstract(07-05-2008).pdf

736-mum-2007-abstract.doc

736-mum-2007-abstract.pdf

736-mum-2007-claims(granted)-(07-05-2008).doc

736-mum-2007-claims(granted)-(07-05-2008).pdf

736-mum-2007-claims.doc

736-mum-2007-claims.pdf

736-mum-2007-correspondence(07-05-2008).pdf

736-mum-2007-correspondence(ipo)-(25-06-2008).pdf

736-mum-2007-description (complete).pdf

736-mum-2007-form 1(07-05-2008).pdf

736-mum-2007-form 2(granted)-(07-05-2008).doc

736-mum-2007-form 2(granted)-(07-05-2008).pdf

736-mum-2007-form 3(07-05-2008).pdf

736-mum-2007-form 9(16-04-2007).pdf

736-mum-2007-form-1.pdf

736-mum-2007-form-18.pdf

736-mum-2007-form-2.doc

736-mum-2007-form-2.pdf

736-mum-2007-form-3.pdf

736-mum-2007-form-9.pdf