FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
(See Section 10)
THERMALLY CONDUCTING, WATER REPELLANT, FIRE RETARDANT, ANTI TRACKING AND HIGH TEMPERATURE WITHSTANDING SILICONE ELASTOMER IMPREGNATED FIBRE-GLASS CLOTH TAPE FOR ELECTRICAL INSULATION AND THE PROCESS OF MANUFACTURING THE SAME.
PRS Solutions Private Limited, a 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 and ascertain the nature of this invention and the manner in which it is to be performed
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FIELD OF THE INVENTION:
The invention relates to " Thermally Conducting, Water Repellant, Fire Retardant, Anti Tracking And High Temperature Withstanding Silicone Elastomer Impregnated Fibre-Glass Cloth Tape For Electrical Insulation And the process of manufacturing the same.
DESCRIPTION OF THE PRIOR-ART:
Various types of electrical insulation tapes are available in the market. But the said tapes do not have all the properties such as thermal conductivity, water repellancy, anti-tracking properties.
Glass is generally used for insulation applications where application of high temperature is a key feature. This type of insulation comes in a wide variety of forms including solid glass, fiberglass tapes, fiberglass sheets and mats, woven tubing and cloth, and various composites.
Silicone rubbers are commonly used for insulating and cushioning electrical and electronic assemblies. Silicone rubbers exhibit some inherent characteristics including superb chemical resistance, high temperature performance, good thermal and electrical resistance, long term resiliency and easy fabrication. Liquid silicone rubbers are also available in electrical grades for conformal coating, potting and gluing..
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Glass cloth impregnated with a silicone elastomer available in the market has good resistance to Corona discharges, weathering, oxidation and fungus attack allied with good moisture resistance but does not have good thermal conductivity. To overcome the above problems, new tape having the above referred properties clubbed together are included in the present invention.
SUMMARY OF THE INVENTION:
In the present invention an attempt has been made to prepare a thermally conducting, silicone- elastomer impregnated glass cloth tape for high-temperature electrical insulation purpose.
The manufacturing of the "Thermally Conducting, Water Repellant, Fire Retardant, Anti Tracking And High Temperature Withstanding Silicone Elastomer Impregnated Fibre-Glass Cloth Tape For Electrical Insulation comprises of coating a formulated silicone elastomer to the extent of 50-150 gm per square meter on one side of a woven glass fabric of the required construction, commensurate with the desired properties of thickness and strength. The coating is carried out by use of conventional methods followed by drying operation which is also carried out by known conventional methods. The other side of the woven glass fabric is then coated with a pressure sensitive silicone adhesive with a dry adhesive deposition of 10 to 100 g/m2 . This coating is carried out by use of conventional coating methods which is followed by drying operation by passing through conventional coating and drying oven at high
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temperature ranging between 100°C to 300°C temperature. . The adhesive side of the coated product so produced is protected by lamination of embossed HDPE or PVC film as release liners.
The formulated silicone elastomer is prepared by compounding two or more silicone elastomers having different hardness on a two-roll milling machine/Banbury machine, with fillers and two or more additives as applicable to impart the properties of thermal conductivity .Fillers and additives such as Titanium di oxide, Alluminium trihydroxide and /or Boron trinitride are added to the formulated silicone elastomer to achieve desired properties of fire retardency and thermal conductivity. The said compounded silicone elastomer is then optionally dispensed in solvent of aliphatic/aromatic nature to obtain consistency and flow properties required and commensurate with the coating method and equipment to be used.
The pressure sensitive silicone adhesive consists of silicone gum & silicone resin. The resin is used as a tackifier & for adjusting the physical properties of the pressure sensitive adhesive. The polymers are dissolved in a solvent & chemically reacted in such a fashion that condensation takes place. The condensation reaction of SiOH groups proceeds readily as water is removed. The silicone pressure sensitive adhesive used for coating on the other side of the silicone elastomer coated fabric is formulated and cured/dried at high temperature to increase the cohesive strength of the adhesive and also to get the desired level of adhesion and tack. The formulated silicone pressure sensitive adhesive can be further
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diluted to coatable consistency and texture commensurate to the coating equipment using aromatic solvents. For curing of the formulated silicone adhesive an organic peroxide catalyst like Benzoyl peroxide or 2 4, dichloro Benzoyl peroxide is added in desired proportion.
The tape so obtained is cut to desired sizes and shapes and has the following features:-
(a) Thermal conductivity (b)High electrical insulation,
(c) Anti-tracking,
(d) High-temperature withstanding capability, and
(e) Water repellency.
CONSTRUCTION:

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Formulated Silicone Elastomer Fibre Glass Cloth Formulated Silicone Adhesive Embossed HDPE/PVC film liner

WE CLAIM:
1. Thermally Conducting, Water Repellant, Fire Retardant, Anti
Tracking And High Temperature Withstanding Silicone Elastomer
Impregnated Fibre-Glass Cloth Tape For Electrical Insulation comprises
of the following steps:-
(a) (i) coating one side of a woven glass fabric with a formulated silicone elastomer to achieve the required silicone elastomer weight by use of conventional coating methods followed by drying with conventional methods; (a) (ii) coating other side of the silicone elastomer coated woven glass fabric with a pressure sensitive silicone adhesive and with required quantity of catalyst by use of conventional coating methods followed by drying with conventional methods; (b)the coated fabric so obtained is cut to desired sizes and shapes.
2. Thermally Conducting, Water Repellant, Fire Retardant, Anti
Tracking And High Temperature Withstanding Silicone Elastomer
Impregnated Fibre-Glass Cloth Tape For Electrical Insulation as claimed
in Claim 1 wherein the said formulated silicone elastomer is made by
compounding at least one or more silicone elastomers with fillers and at
least one or more additives to impart thermal conductivity properties on a
two-roll milling machine.
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3. Thermally Conducting, Water Repellant, Fire Retardant, Anti
Tracking And High Temperature Withstanding Silicone Elastomer
Impregnated Fibre-Glass Cloth Tape For Electrical Insulation as claimed
in claims 1 and 2 wherein the said silicone elastomer is dissolved in
solvent of aliphatic/aromatic nature to obtain consistency and flow
properties required; and commensurate with the coating method and
equipment to be used ;
4. Thermally Conducting, Water Repellant, Fire Retardant, Anti Tracking And High Temperature Withstanding Silicone Elastomer Impregnated Fibre-Glass Cloth Tape For Electrical Insulation as claimed in Claims 1 and 2 wherein the said filler is Titanium-di-oxide.
5. Thermally Conducting, Water Repellant, Fire Retardant, Anti Tracking And High Temperature Withstanding Silicone Elastomer Impregnated Fibre-Glass Cloth Tape For Electrical Insulation as claimed in Claims 1 and 2 wherein the said additives are Alluminium tri hydroxide and /or Boron trinitride.
6. Thermally Conducting, Water Repellant, Fire Retardant, Anti
Tracking And High Temperature Withstanding Silicone Elastomer
Impregnated Fibre-Glass Cloth Tape For Electrical Insulation as claimed
in Claim 1 wherein the pressure sensitive silicone adhesive consists of
silicone gum & silicone resin.
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7. Thermally Conducting, Water Repellant, Fire Retardant, Anti Tracking And High Temperature Withstanding Silicone Elastomer Impregnated Fibre-Glass Cloth Tape For Electrical Insulation as claimed in claim 1 wherein the said catalyst is an organic peroxide catalyst like Benzoyl peroxide or 2, 4, dichloro Benzoyl peroxide.
8. Thermally Conducting, Water Repellant, Fire Retardant, Anti Tracking And High Temperature Withstanding Silicone Elastomer Impregnated Fibre-Glass Cloth Tape For Electrical Insulation and the process of manufacturing the same as claimed in Claim 1 to 7 by which thermally conducting, water repellant, fire retardant, anti tracking and high temperature withstanding silicone elastomer impregnated fibre-glass cloth tape for electrical insulation is obtained.
Dated this 12th day of March, 2007

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ABSTRACT
Thermally Conducting, Water Repellant, Fire Retardant, Anti Tracking And High Temperature Withstanding Silicone Elastomer Impregnated Fibre-Glass Cloth Tape For Electrical Insulation comprises of (a) coating one side of a woven glass fabric with a formulated silicone elastomer to achieve the required silicone elastomer weight followed by drying with conventional methods; (b) coating other side of the silicone elastomer coated woven glass fabric with a pressure sensitive silicone adhesive and with required quantity of catalyst and thereafter, followed by drying with conventional methods; and (c) the coated fabric so obtained is cut to desired sizes and shapes.
Dated this 12th day of March, 2007