Title of Invention	"AN IMPROVED PROCESS FOR THE PREPARATION OF PHOTO-CURABLE COMPOSITION FOR DRY RESIST APPLICATION"
Abstract	An improved process for the preparation of photo-curable composition for dry resist application comprising, mixing in an yellow light atmosphere, characterized by photo-curable polymer solution as herein described with 0.1 to 5.0% of an organic dye as herein described, 0.1 to 0.5% of sensitizer like benzophenone, michlers ketone as photo-initiator, cross linking monomer and a solvent as herein described for a period ranging form 20 to 60 minutes, at a temperature in the range of 25 to 35°C, till uniform consistency is achieved and collecting the product in the form of a solution.

Title of Invention

"AN IMPROVED PROCESS FOR THE PREPARATION OF PHOTO-CURABLE COMPOSITION FOR DRY RESIST APPLICATION"

Abstract

An improved process for the preparation of photo-curable composition for dry resist application comprising, mixing in an yellow light atmosphere, characterized by photo-curable polymer solution as herein described with 0.1 to 5.0% of an organic dye as herein described, 0.1 to 0.5% of sensitizer like benzophenone, michlers ketone as photo-initiator, cross linking monomer and a solvent as herein described for a period ranging form 20 to 60 minutes, at a temperature in the range of 25 to 35°C, till uniform consistency is achieved and collecting the product in the form of a solution.

Full Text	This invention relates to an improved process for the preparation of photo- curable compositions for dry resist applications. More particularly, it relates to a process for the preparation of photo-curable compositions that are aqueous developable formulations and useful for image transfer applications. The photo- curable compositions prepared by the process of this invention is prepared by using a polymer solution containing multi-functional groups. In our copending application number we have described and claimed a process for the preparation of copolymers with multifunctional groups. The photo-curable compositions prepared by the process of this invention are useful for transfer of image onto a printed circuit board or lithographic plate as dry resists. Dry resists are important imaging system which are extensively used in the manufacture of wire boards and printed circuit boards. The dry resist essentially consists of a photocurable composition sandwiched between a polyester base sheet and a polyethylene cover foil. In applications, the cover foil is removed and the base sheet is laminated onto a copper clad insulating support. The copper clad insulating support is then selectively exposed to UV source through a photomask. The photomask comprises of parts that are opaque and others transparent to UV source. The differential parts of the photomask thus transfer an image to the copper clad insulating support. The photo-curable compositions prepared as per the process of this invention, fall into the category of negative photoresists. In this category of photoresists, the areas exposed to UV source, become insoluble in a developing solution as a result of the photochemical reaction occurring during exposure to UV source. The unexposed areas are soluble in the developing solution and can be removed whereby an image is transferred to the copper clad insulating support. In the formulation of photo-curable composition, the essential • ingredients are the polymer solution which normally consists of a tri, tetra polymer with composition of choice, a dye, a sensitizer, crosslinking monomer, photo-initiator, solvent. However, if the composition has to be as a formulation in applications such as PCB industries, the parameters that go into the preparation of the compositions becomes critical. If the right ingredients are not maintained the coating thickness would vary and the non-uniformity would pose problems in processing. The known compositions available suffers from the disadvantage that the formulations cannot be changed to suit the convenience of the user so that minor changes in terms of exposure time, and processing parameters. The formulation should give uniform film forming characteristics. The primary requirements for applications in electronics industries are - 1. The polymer should contain carboxylic acid groups such that the polymer after exposure to UV source should be aqueous soluble. 2. The polymer should have sufficient mechanical strength so that during the processing stage, the film remains in tact. 3. The polymer should contain aromatic groups so that quantum efficiency during the photochemical reaction step is possible. 4. The glass temperature of the polymer should be close to ambient temperature. These characteristics should not be disturbed while making a suitable formulation. The main object of the present invention is therefore to provide a process for the preparation of photo-curable compositions with improved film characteristics and aqueous developable. Another object of the present invention is to provide a process for the preparation of photo-curable compositions such that the glasss transition temperature and mechanical strength are not altered. Yet another object of the present: invention is to provide a process for the preparation of photo-curable compositions that does no disturb the photochemical reaction to give image of choice after developing. Accordingly, the present invention provides an improved process for the preparation of photo-curable composition for dry resist application comprises, mixing in an yellow light atmosphere, photo-curable polymer solution as herein described with 0.1 to 5.0% of an organic dye as herein described, 0.1 to 0.5% of sensitizer like benzophenone, michlers ketone as photo-initiator, cross linking monomer and a solvent as herein described for a period ranging form 20 to 60 minutes, at a temperature in the range of 25 to 35°C, till uniform consistency us achieved and collecting the product in the form of a solution. Accordingly, the present invention provides a process for the preparation of photo-curable compositions with improved viscosity which comprises, reacting in an inert atmosphere, a photo-curable formulation prepared as described and claimed in our copending application number with an aliphatic amine for a period ranging from 10 to 30 minutes, at a temperature in the range of 25 to 35°C and collecting the resultant product in the form of a solution. In one of the embodiments of the invention, the inert gas used may be nitrogen, argon. In another embodiment the aliphatic amine used may be hexylamine, octyl amine, dodecyl amine and the concentration used may be 0.1 to 0.05%. In still another embodiment of the present invention, the photo-curable formulation used may be prepared by mixing in an yellow light atmosphere, a photo-curable polymer solution with an organic dye, a sensitizer, photo-initiator, crosslinking monomer, solvent, for a period ranging from 20 to 60 minutes, at a temperature in the range of 25 to 35°C, till uniform consistency is achieved and collecting the product in the form of a solution. The process of the present invention is described with reference to following examples, which are illustrative only and should not be construed to limit the scope of this invention in any manner. EXAMPLE - 1 In an inert atmosphere of nitrogen, to 100 ml of polymer solution was added 0.15 gms of octyl amine and solution was maintained isothermally at 25°C for 15 minutes. The stirring rate was maintained at 300 rpm. The product remaining at the end of 15 minutes of reaction, was collected in the form of a solution. The yield obtained was 100 ml. EXAMPLE-1 To 20 ml of polymer solution was mixed with 0.4 gms of benzophenone, 0.02 gms of michler's ketone, 0.04 gms of malachite green, 2.0 ml of ethylene glycol dimethacrylate, 0.5ml of methyl iso butyl ketone and 1.5 ml of isopropanol and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 26 ml. EXAMPLE-2 To 20 ml of polymer solution was mixed with 2.0 gms of benzophenone, 0.04 gms of michler's ketone, 0.08 gms of malachite green, 2.0 ml of ethylene glycol dimethacrylate, 0.5ml of methyl isc outyi keL^ne and 1.5 ml of isopropanol and the solution was maintained isothermally at 30°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 26 ml. Example 3 To 20 ml of polymer solution was mixed with 1.0 gms of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 2.0 ml of ethylene glycol dimethacrylate, 4.0ml of methyl iso butyl ketone and the solution was maintained isothermally at 35°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 27 ml. EXAMPLE - 4 To 100 ml of polymer solution was mixed with 2.5gms of benzophenone, 0.2 gms of michler's ketone, 0.2 gms of malachite green, 5.0 ml of ethylene glycol dimethacrylate, 10ml of methyl ethyl ketone and the solution was maintained .isothermally at 35°C for 60 minutes. The product remaining at the end of 60 minutes of reaction, was collected in the form of a solution. The yield obtained was 1 IS ml. Example 5 To 100 ml of polymer solution was mixed with 2.5 gms of benzophenone, 0.2 gms of michler's ketone, 0.2 gms of malachite green, 10.0 ml of ethylene glycol dimethacrylate, 10ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 60 minutes. The product remaining at the end of 60 minutes of reaction, was collected in the form of a solution. The yield obtained was 120 ml. EXAMPLE - 6 To 20 ml of polymer solution was mixed with l.Ogm of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 2.0 ml of pentaerythritol triacrylatel 4.0 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 26 ml. EXAMPLE - 7 To 100 ml of polymer solution was mixed with 5.0 gms of benzophenone, 0.4 gms of michler's ketone, 0.4 gms of malachite green, 15.0 ml of penta erythritol triacrylate, 20 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 50 minutes. The product remaining at the end of 50 minutes of reaction, was collected in the form of a solution. The yield obtained was 135 ml. EXAMPLE-8 To 20 ml of polymer solution was mixed with 1.0 gm of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 4.0 ml of penta erythritol triacrylate, 4.0ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product ;cmaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 28 mi. EXAMPLE-9 To 20 ml of polymer solution was mixed with 1.0 gms of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 4.0 ml of penta erythritol triacrylate, 7.0 ml of methyl iso butyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 31 ml. EXAMPLE -10 To 100 ml of polymer solution was mixed with 5.0 gms of benzophenone, 0.4 gms of michler's ketone, 0.4 gms of malachite green, 6.0 ml of penta erythritol triacrylate, 6.0 ml of methyl iso butyl ketone and the solution was maintained isothermally at 25°C for 60 minutes. The product remaining at the end of 60 minutes of reaction, was collected in the form of a solution. The yield obtained was 112 mi. EXAMPLE-11 To 20 ml of polymer solution was mixed with 1.0 gm of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 4.0 ml of penta erythritoi triacrylate, 16 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 40 ml. EXAMPLE-12 To 20 ml of polymer solution was mixed with 0.5 gms of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of crystal violet, 4.0 ml of penta erythritol triacrylate, 4.0 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 40 minutes. The product remaining at the end of 40 minutes of reaction, was collected in the form of a solution. The yield obtained was 28 ml. EXAMPLE -13 To 100 ml of polymer solution was mixed with 2.0 gms of benzophenone, 0.1 gms of michler's ketone, 0.1 gm of crystal violet, 10.0 ml of ethylene glycol dimethacrylate, 7.5 ml of methyl iso butyl ketone and 2.5 ml of isopropanol and the solution was maintained isothermaiiy at 15°C for 60 minutes. The product remaining at tlie uid ot 60 minutes of reaction, was collected in the form of a solution. The yield obtained was 120 ml. EXAMPLE -14 20 ml of polymer solution was mixed with 1.0 gm of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 4.0 ml of penta erythritol triacrylate, 8.0 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 32 ml. WE CLAIM; 1. An improved process for the preparation of photo-curable composition for dry resist application comprising, mixing in an yellow light atmosphere, characterized by photo-curable polymer solution as herein described with 0.1 to 5.0% of an organic dye as herein described, 0.1 to 0.5% of sensitizer like benzophenone, michlers ketone as photo-initiator, cross linking monomer and a solvent as herein described for a period ranging form 20 to 60 minutes, at a temperature in the range of 25 to 35°C, till uniform consistency is achieved and collecting the product in the form of a solution. 2. A process as claimed in claim 1, wherein the organic dye used may be selected from malachite green, crystal violet. 3. A process as claimed in claim 1, wherein the said photo-curable polymer contains particularly carboxylic acid groups. 4. A process as claimed in claims 1 and 4, wherein, the cross-linking monomer used may be selected from ethylene glycol dimethacrylate, penta erythritol triacrylate. 5. A process as claimed in claims 1 and 5, wherein the solvent used for the formulation used may be methyl ethyl ketone, methyl isobutyl ketone, isopropanol, and their mixtures. 6. A process for the preparation of photo-curable compositions for dry film resists as substantially described with reference to the examples.

Full Text

This invention relates to an improved process for the preparation of photo-
curable compositions for dry resist applications. More particularly, it relates to a
process for the preparation of photo-curable compositions that are aqueous
developable formulations and useful for image transfer applications. The photo-
curable compositions prepared by the process of this invention is prepared by using a
polymer solution containing multi-functional groups. In our copending application
number we have described and claimed a process for the preparation of
copolymers with multifunctional groups.
The photo-curable compositions prepared by the process of this invention are useful for transfer of image onto a printed circuit board or lithographic plate as dry resists.
Dry resists are important imaging system which are extensively used in the manufacture of wire boards and printed circuit boards. The dry resist essentially consists of a photocurable composition sandwiched between a polyester base sheet and a polyethylene cover foil. In applications, the cover foil is removed and the base sheet is laminated onto a copper clad insulating support. The copper clad insulating support is then selectively exposed to UV source through a photomask. The photomask comprises of parts that are opaque and others transparent to UV source. The differential parts of the photomask thus transfer an image to the copper clad insulating support.
The photo-curable compositions prepared as per the process of this invention, fall into the category of negative photoresists. In this category of photoresists, the areas exposed to UV source, become insoluble in a developing solution as a result of the photochemical reaction occurring during

exposure to UV source. The unexposed areas are soluble in the developing solution and can be removed whereby an image is transferred to the copper clad insulating support.
In the formulation of photo-curable composition, the essential
•
ingredients are the polymer solution which normally consists of a tri, tetra polymer with composition of choice, a dye, a sensitizer, crosslinking monomer, photo-initiator, solvent. However, if the composition has to be as a formulation in applications such as PCB industries, the parameters that go into the preparation of the compositions becomes critical. If the right ingredients are not maintained the coating thickness would vary and the non-uniformity would pose problems in processing.
The known compositions available suffers from the disadvantage that the formulations cannot be changed to suit the convenience of the user so that minor changes in terms of exposure time, and processing parameters. The formulation should give uniform film forming characteristics. The primary requirements for applications in electronics industries are -
1. The polymer should contain carboxylic acid groups such that the
polymer after exposure to UV source should be aqueous soluble.
2. The polymer should have sufficient mechanical strength so that
during the processing stage, the film remains in tact.
3. The polymer should contain aromatic groups so that quantum
efficiency during the photochemical reaction step is possible.

4. The glass temperature of the polymer should be close to ambient temperature.
These characteristics should not be disturbed while making a suitable formulation.
The main object of the present invention is therefore to provide a process for the preparation of photo-curable compositions with improved film characteristics and aqueous developable.
Another object of the present invention is to provide a process for the preparation of photo-curable compositions such that the glasss transition temperature and mechanical strength are not altered.
Yet another object of the present: invention is to provide a process for the preparation of photo-curable compositions that does no disturb the photochemical reaction to give image of choice after developing.
Accordingly, the present invention provides an improved process for the preparation of photo-curable composition for dry resist application comprises, mixing in an yellow light atmosphere, photo-curable polymer solution as herein described with 0.1 to 5.0% of an organic dye as herein described, 0.1 to 0.5% of sensitizer like benzophenone, michlers ketone as photo-initiator, cross linking monomer and a solvent as herein described for a period ranging form 20 to 60 minutes, at a temperature in the range of 25 to 35°C, till uniform consistency us achieved and collecting the product in the form of a solution.

Accordingly, the present invention provides a process for the preparation of photo-curable compositions with improved viscosity which comprises, reacting in an inert atmosphere, a photo-curable formulation prepared as described and claimed in our copending application number with an aliphatic amine for a period ranging from 10 to 30 minutes, at a temperature in the range of 25 to 35°C and collecting the resultant product in the form of a solution.
In one of the embodiments of the invention, the inert gas used may be nitrogen, argon.
In another embodiment the aliphatic amine used may be hexylamine, octyl amine, dodecyl amine and the concentration used may be 0.1 to 0.05%.
In still another embodiment of the present invention, the photo-curable formulation used may be prepared by mixing in an yellow light atmosphere, a photo-curable polymer solution with an organic dye, a sensitizer, photo-initiator, crosslinking monomer, solvent, for a period ranging from 20 to 60 minutes, at a temperature in the range of 25 to 35°C, till uniform consistency is achieved and collecting the product in the form of a solution. The process of the present invention is described with reference to following examples, which are illustrative only and should not be construed to limit the scope of this invention in any manner.
EXAMPLE - 1
In an inert atmosphere of nitrogen, to 100 ml of polymer solution was added 0.15 gms of octyl amine and solution was maintained isothermally at 25°C for 15 minutes. The stirring rate was maintained at 300 rpm. The product remaining at the end of 15 minutes of reaction, was collected in the form of a solution. The yield obtained was 100 ml.

EXAMPLE-1
To 20 ml of polymer solution was mixed with 0.4 gms of benzophenone, 0.02 gms of michler's ketone, 0.04 gms of malachite green, 2.0 ml of ethylene glycol dimethacrylate, 0.5ml of methyl iso butyl ketone and 1.5 ml of isopropanol and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 26 ml.
EXAMPLE-2
To 20 ml of polymer solution was mixed with 2.0 gms of benzophenone, 0.04 gms of
michler's ketone, 0.08 gms of malachite green, 2.0 ml of ethylene glycol dimethacrylate, 0.5ml of methyl isc outyi keL^ne and 1.5 ml of isopropanol and the solution was maintained isothermally at 30°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 26 ml.
Example 3
To 20 ml of polymer solution was mixed with 1.0 gms of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 2.0 ml of ethylene glycol dimethacrylate, 4.0ml of methyl iso butyl ketone and the solution was maintained isothermally at 35°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 27 ml.
EXAMPLE - 4
To 100 ml of polymer solution was mixed with 2.5gms of benzophenone, 0.2 gms of
michler's ketone, 0.2 gms of malachite green, 5.0 ml of ethylene glycol dimethacrylate, 10ml of methyl ethyl ketone and the solution was maintained

.isothermally at 35°C for 60 minutes. The product remaining at the end of 60 minutes of reaction, was collected in the form of a solution. The yield obtained was 1 IS ml.
Example 5
To 100 ml of polymer solution was mixed with 2.5 gms of benzophenone, 0.2 gms of michler's ketone, 0.2 gms of malachite green, 10.0 ml of ethylene glycol dimethacrylate, 10ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 60 minutes. The product remaining at the end of 60 minutes of reaction, was collected in the form of a solution. The yield obtained was 120 ml.
EXAMPLE - 6
To 20 ml of polymer solution was mixed with l.Ogm of benzophenone, 0.08 gms of
michler's ketone, 0.08 gms of malachite green, 2.0 ml of pentaerythritol triacrylatel 4.0 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 26 ml.
EXAMPLE - 7
To 100 ml of polymer solution was mixed with 5.0 gms of benzophenone, 0.4 gms of michler's ketone, 0.4 gms of malachite green, 15.0 ml of penta erythritol triacrylate, 20 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 50 minutes. The product remaining at the end of 50 minutes of reaction, was collected in the form of a solution. The yield obtained was 135 ml.

EXAMPLE-8
To 20 ml of polymer solution was mixed with 1.0 gm of benzophenone, 0.08 gms of
michler's ketone, 0.08 gms of malachite green, 4.0 ml of penta erythritol triacrylate, 4.0ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product ;cmaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 28 mi.
EXAMPLE-9
To 20 ml of polymer solution was mixed with 1.0 gms of benzophenone, 0.08 gms of
michler's ketone, 0.08 gms of malachite green, 4.0 ml of penta erythritol triacrylate, 7.0 ml of methyl iso butyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 31 ml.
EXAMPLE -10
To 100 ml of polymer solution was mixed with 5.0 gms of benzophenone, 0.4 gms of
michler's ketone, 0.4 gms of malachite green, 6.0 ml of penta erythritol triacrylate, 6.0 ml of methyl iso butyl ketone and the solution was maintained isothermally at 25°C for 60 minutes. The product remaining at the end of 60 minutes of reaction, was collected in the form of a solution. The yield obtained was 112 mi.
EXAMPLE-11
To 20 ml of polymer solution was mixed with 1.0 gm of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 4.0 ml of penta erythritoi triacrylate, 16 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 40 ml.

EXAMPLE-12
To 20 ml of polymer solution was mixed with 0.5 gms of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of crystal violet, 4.0 ml of penta erythritol triacrylate, 4.0 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 40 minutes. The product remaining at the end of 40 minutes of reaction, was collected in the form of a solution. The yield obtained was 28 ml.
EXAMPLE -13
To 100 ml of polymer solution was mixed with 2.0 gms of benzophenone, 0.1 gms of
michler's ketone, 0.1 gm of crystal violet, 10.0 ml of ethylene glycol dimethacrylate, 7.5 ml of methyl iso butyl ketone and 2.5 ml of isopropanol and the solution was maintained isothermaiiy at 15°C for 60 minutes. The product remaining at tlie uid ot 60 minutes of reaction, was collected in the form of a solution. The yield obtained was 120 ml.
EXAMPLE -14
20 ml of polymer solution was mixed with 1.0 gm of benzophenone, 0.08 gms of michler's ketone, 0.08 gms of malachite green, 4.0 ml of penta erythritol triacrylate, 8.0 ml of methyl ethyl ketone and the solution was maintained isothermally at 25°C for 30 minutes. The product remaining at the end of 30 minutes of reaction, was collected in the form of a solution. The yield obtained was 32 ml.

WE CLAIM;
1. An improved process for the preparation of photo-curable composition for dry resist application comprising, mixing in an yellow light atmosphere, characterized by photo-curable polymer solution as herein described with 0.1 to 5.0% of an organic dye as herein described, 0.1 to 0.5% of sensitizer like benzophenone, michlers ketone as photo-initiator, cross linking monomer and a solvent as herein described for a period ranging form 20 to 60 minutes, at a temperature in the range of 25 to 35°C, till uniform consistency is achieved and collecting the product in the form of a solution.
2. A process as claimed in claim 1, wherein the organic dye used may be selected from malachite green, crystal violet.
3. A process as claimed in claim 1, wherein the said photo-curable
polymer contains particularly carboxylic acid groups.
4. A process as claimed in claims 1 and 4, wherein, the cross-linking
monomer used may be selected from ethylene glycol
dimethacrylate, penta erythritol triacrylate.
5. A process as claimed in claims 1 and 5, wherein the solvent used
for the formulation used may be methyl ethyl ketone, methyl
isobutyl ketone, isopropanol, and their mixtures.
6. A process for the preparation of photo-curable compositions for dry
film resists as substantially described with reference to the
examples.

Documents:

813-del-2000-abstract.pdf

813-del-2000-claims.pdf

813-del-2000-correspondence-others.pdf

813-del-2000-correspondence-po.pdf

813-del-2000-description (complete).pdf

813-del-2000-form-1.pdf

813-del-2000-form-19.pdf

813-del-2000-form-2.pdf

813-del-2000-form-3.pdf

813-del-2000-pa.pdf

813-del-2000-petition-138.pdf

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Patent Number

230922

Indian Patent Application Number

813/DEL/2000

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

28-Feb-2009

Date of Filing

07-Sep-2000

Name of Patentee

THE SECRETARY, MINISTRY OF INFORMATION TECHNOLOGY, GOVT. OF INDIA,

Applicant Address

ELECTRONICS NIKETAN, 6 CGO COMPLEX LODHI ROAD, NEW DELHI-110003, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	CHELANATTU KHIZHAKKE	SCIENTIS IPM DIVISION, COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH, RAFI MARG, NEW DELHI-110001
2	MADATH RAMAN RAJAN	SCIENTIS IPM DIVISION, COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH, RAFI MARG, NEW DELHI-110001
3	SURENDRA PONRATHNAM	SCIENTIS IPM DIVISION, COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH, RAFI MARG, NEW DELHI-110001
4	VARSHA BHIKOBA GHADGE	SCIENTIS IPM DIVISION, COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH, RAFI MARG, NEW DELHI-110001

PCT International Classification Number

G03C 5/30

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA