Title of Invention

AN EVAPORATION BOAT USEFUL FOR METALLIZATION AND A PROCESS FOR THE PREPRATIONS OF SUCH BOATS

Abstract An improved ceramic evaporation boat produced with Boron Nitride, Aluminium Nitride, Nickel and Titanium Diboride with bend strength ranging from 90-99 Mpa and density greater than 97% of TD and metallisation life ranging from 20-28 hours useful for metallizing aluminium on plastics, paper, wood etc.. The present invention also relates to a process for producing the above said titanium boride (TiBz) based ceramic evaporation boats.
Full Text

FIELD OF INVENTION:
The present invention relates to improved evaporation boat for nnetallization and a process for the preparation of such boats The invention particularly relates to titanium boride (TiBa) based ceramic evaporation boats The titanium boride (TiB2) based ceramic evaporation boats of the present invention are useful have improved electrical, thermal and mechanical properties and have longer life Therefore they and are useful in the industries like packaging, wood, capacitor films as wrappers and for decoration purposes.
The present invention particularly relates to an improved process for producing high-density titanium boride based ceramic composite by uni-axial hot pressing. The present invention also relates to a sequence of powder mixing and use of a particular milling agent and process of uni-axial green pressing followed by hot pressing which result in an improved boat with better properties.
BACKGROUND OF THE INVENTION:
The coatings based on metals like Ai, Sn and other metals on plastics (like polypropylene) made by using the above types of boats are commercially and widely used in the industries like packaging, wood, capacitor as wrappers and for decoration purposes. The boats are resistively beatable and simultaneously act like crucibles holding the molten aluminium. However, there exists a limitation to use these boats beyond a time period and the limitation arises from the fact that these boats exhibit shorter life span due to aluminium melt attack.
Traditionally, graphite based boats have been employed to obtain coatings of AI on polypropylene and other materials. But the life of such boats was very short as compared to the boats made of boride and thereby cannot provide longer duration. Therefore fewer throughputs of metallised wrapping/foils. Moreover, coating deposition rates achieved are low using the graphite boats.

Coatings like Boron nitride or titanium carbide given on graphite boats caused increased metallisation times thereby causing an increase in out put of metallised rollls produced using such coated boats. It was observed that the life of boats after coating with BN was increased by 100 %. The coating was carried out using a gas phase reaction involving boron tri chloride and ammonia. In US Patent Nos. 4264803, the graphite bar is totally encapsulated over its entire outer surface including the boat cavity, with a continues coating of pyrolytic boron nitride (PBN) and then the PBN coating is removed from both the ends of the bar to provide electrical contact zones for connecting the bar to a power source. The pyrolytic boron nitride coating conducts heat from graphite bar to the metal in the cavity effectively but since pyrolytic boron nitride has low emissivity compared to the intermetallic composites, it radiates low energy. The high resistance of pyrolytic boron nitride to attack by aluminium and other metals have helped him prolonging the life of the boats. The extent of prolongation has not been mentioned in the patent.
However, the adherence of the Boron nitride coating cannot be increased beyond a particular level and this limits the process in terms of life of the boat and hence throughput.
Powder coatings based on boron nitride (BN) and titanium carbide (TIC) which can also be prepared and coated by specially developed manufacturing routes such as sol-gel are inefficient when Al is melted repeatedly and wears out due to Aluminium melt attack and the costs are high due to high cost of precursors.
Research work in the area of developing an improved uni-axial hot pressing (with boride based composition including Boron nitride and Aluminium Nitride ) process has gained importance globally for the past two decades to overcome the above mentioned difficulties and limitations and make boats with improved electrical, thermal and mechanical properties having higher density and excellent corrosion resistance.
There exist a good number of patents and publications which deal with the fabrication of evaporation boats by uni-axial hot pressing (with boride based composition including Boron nitride and Aluminium Nitride ) process

In U.S. Pat. No. 4373952 the process involved preparation of an intermetallic composite which comprised the following ingredients in weight percent at about 50.2%. Titanium diboride about 30.0% of boron nitride, about 11.9% aluminium nitride and about 7.9% tungsten.These ingredients were blended in a ball mill to provide a substantially homogenous mixture. The mixture was then placed in a graphite mould and hot pressed at 1950°C at a pressure of 3000 PSI. The finished composite had a density of 91.6 of the Theoretical Density and resistivity of 750 micro ohms - centimeter. The addition of tungsten has resulted in improvement of life expectancy by 80% longer than the control (as claimed in the patent) The erosion and drop of resistivity was lower and thereby it gave a longer life to the boats. Although the boats were superior in terms of percentage theoretical density achieved as compared to the prior art, the usage of expensive tungsten powders was adding to the boat's cost.
In the invention cited above, the inventors achieved a sintered density, which is 91.6% theoretical as against 95% T.D. needed for longer life and metallization. That is why the boats obtained through the invention were exhibiting lower life.
U.S. Pat No. 5604164 granted to Montgomery A refractory boat was fabricated using a binary composite composition of titanium diboride and boron nitride in combination withMo, CaO nd Y2O3. It may also be fabricated with a ternary composition and in either case MO is added in combination with an oxide of calcium of yttrium. The result being substantial improvement in the wetting of the boat cavity by aluminium and longer life of boat. Though the composite was successfully hot pressed with >90% T.D., the ideal sintered density of 95% T.D. was not achieved in all cases and the system became too complicate with too many additives like MO, CAO and Y2O3. The addition of metal plus oxide was however restricted to a maximum of 20 wt% in the hot pressed compacts
U.S. Pat No. 3915900 awarded to M/s. Reinmuth Klaus etal is about the effect of B2O3 present on powders on the sintering of these composites. In this patent 50 parts of by weight of titanium diboride, 30 parts by weight of boron nitride and 20 parts by weight of aluminium nitride and 2 to 10% B2O3 and mixed dry and sintered in

a graphite mould at a pressure of 150 kg. per centimeter and at a temperature of 2100 °C . The effect of oxy nitride layers originally present were found to be more beneficial than the freshly added B203 layers . Though high densities > 90 % T.D could be achieved by the selective oxidation as mentioned in the patent, the selective oxidation of BN is difficult to achieve as the other components namely TiBa and AIN used in the process are also prone to oxidation and there is a possibility of losing the conductive network of TiB2 grains which are essential for boat operation could be lost. Taking Boron nitride powders separately before mixing and oxidizing them preferentially will only add to the cost.
The evaporation boat needs to have a network of electrically conductive grains to act like a heater and therefore the maintenance of contiguity even after milling and hot pressing is a foremost factor for its performance.
In the U.S. Pat. No. 5,409,868 , 40 to 70% by volume of titanium boride, 20 to 59 volume percent of hexagonal boron nitride, and the mixture may also contain aluminium nitride in amounts ranging between 0-25 volume percentage, zirconia, hafnia or ceria having particle size of 0.7 microns or less, is added in about 1.5 volume percentage or less. Cobalt diboride or nickel diboride may be added as a sintering aid to the above composition in less than 2 volume percent.
The mixture was ball milled and vibro milled for 13 hours and then cast into ingots, uni-axiallly pressed and sintered in argon by gradually raising the temperature to 1860°C and holding the temperature for one hour. However, the evaluation of duration of life of boat was not carried out and only sintered density was mentioned in their claims/results
As described in the patents No.US 4373952,US patent No.5604164, 3915900 and 5409868, the process employed for fabricating boats has been discussed in detail, but not much has been taken care for maintaining the conducting network of TiB2 grains and to prevent oxidation of powders during handling green pressing and mixing which affects the boats performance.

According to the invention disclosed in U.S. Pat No. 4795723, boric anhydride and dicyandiamide were reacted at 1200°C under nitrogen atmosphere and the reaction product was washed with dilute nitric acid to obtain turbostatic boron nitride. Then 30% by weight of turbostatic boron nitride powder; 8% by weight of alunninium powder (Al (At) - 250 mesh, manufactured by Ful^uda Kin 2aKuhakufu K.K) and 62% by weight of titanium boride powder were thoroughly mixed in a vibration ball mill (using alumina balls) for 20 minutes. The mixture was filled in a cylindrical graphite mould and graphite pushing rods were inserted from top and bottom of the graphite mould for pressing. Then, hot press sintering was conducted at 2000°C under a pressure of 200 kg/cm^ under an argon atmosphere.. The inventor claims the improvements as due to turbostatic boron nitride a metastable phaseinstead of the usual hexagonal boron nitride, which reduces anisotropy. The patent conceives the formation of AIB2 phase due to reaction with Al & BN but the formation of AIB2 phase has been found detrimental as per another US Patent 4373952 as it can give rise to formation of AI2O3 and AIB2 which are anti-wetting surfaces which are not conductive for a smooth metallisation.
Considering the importance gained for the use of titanium boride (TiB2) based ceramic evaporation boats which are required in the industries like packaging, wood, capacitor as wrappers and for decoration purposes , overcoming the drawbacks of the hither to known boards ,we undertook sustained research work to develop improved boards having better electrical, thermal and mechanical properties and have longer life
R&D done by us is based on the above direction . we observed that an improved titanium boride (TiB2) based ceramic evaporation boats having better electrical, thermal and mechanical properties and having longer life can be produced by modifying the processes hitherto employed .Accordingly we found that by changing the milling agent and adding the electrically conducting powder TiB2 after the milling of BN & AIN & Ni and green pressing of the resultant composite to 60% of its Theoretical Density before hot pressing, an improved titanium boride (TiB2) based ceramic evaporation boats having better electrical, thermal and mechanical properties and having longer life can be produced

SUMMARY OF THE INVENTION:
Therefore the main objective of the present invention is to provide an improved titanium boride (TiB2) based ceramic evaporation boats having improved electrical, thermal and mechanical properties and have longer life which are useful in the industries like packaging, wood, capacitor as wrappers and for decoration purposes.
Another objective of the present invention is to provide an improved titanium boride (TiB2) based ceramic evaporation boats having improved electrical, thermal and mechanical properties and have longer life which are useful in the industries like packaging, wood, capacitor as wrappers and for decoration purposes which do not have the defects of the boards in the prior art
Yet another objective of the present invention is to provide an improved titanium boride (TiB2) based ceramic evaporation boats having dense, hard, and ceramic composite based on the ternary system
Still another objective of the present invention is to provide an improved titanium boride (TiB2) based ceramic evaporation boats having better bend strength as compared to the prior art.
Yet another objective of the present invention is to provide an improved titanium boride (TiB2) based ceramic evaporation boats having improved density
Another objective of the present invention is to provide an improved titanium boride (TiB2) based ceramic evaporation boats having longer metallization life.
Yet another objective of the present invention is to provide an improved titanium boride (TiB2) based ceramic evaporation boats having better throughput where cracking is not observed till 28 hours of metallisation.
Still another objective of the present invention is to provide a process for the preparation of improved titanium boride (TiB2) based ceramic evaporation boats

having improved electrical, thermal and mechanical properties and have longer life which are useful in the industries like packaging, wood, capacitor as wrappers and for decoration purposes which do not have the defects of the boards in the prior art
Still another objective of the present invention is to provide a process for the preparation of improved titanium boride (TiB2) based ceramic evaporation boats which is simple and economical
Accordingly ,the present invention provides a process for the preparation of improved titanium boride based ceramic evaporation boats having improved electrical, thermal and mechanical properties and having longer life which are useful in the industries like packaging as wrappers, wood, capacitor films and for other decoration purposes which comprises
(i)mixing boron nitride in weight range of 25-50% and aluminium nitride in weight range of 5 to 25% and nickel in weight range of 1to 5% in a mill with a milling aid for a period ranging 1-10 hours
(ii) adding the resultant mixture to titanium diboride powder 30%-60% during the period ranging from 15 to 45 minutes , taking care not to allow the vigorous milling of these powders and at the same time allowing the conducting powders to effectively smear on the non conducting powders.
(iii) drying the resulting powders in an oven / furnace at a temperature in the range of 100 °C-140 °C to evaporate off the remaining solvent
(iv) screening the dried powders through a mesh in the range of a 100 -200 No. preferably 100 No. mesh to remove the agglomerates ,if any ,and to allow homogeneity.
(v) filling the dried powders in a graphite die of dia ranging from 75-200 mm lined with graphite foil and pressing them at room temperature by Green pressing to 60% of its theoretical density

vi heating the die inductively in a hot press which is ramped initially at a rate of 600 -1000 K/hour and after reaching the hot pressing temperature in the range of 1850-2100 C, applying a pressure of the order of 30-70 MPa , holding the resulting compacts for a period in the range of 15-45 minutes at this temperature to allow the sintering to complete
(vii) cooling the resultant compact /billet in the furnace to room temperature , ejecting them using an ordinary hydraulic press and
(vii) cutting compact / billet to the desired size to obtain the boats .
In a preferred embodiment of the present invention a powder mixture containing boron nitride in weight preferably 35% aluminium nitride in weight range preferably 15% nickel preferably 3% and titanium boride in the weight preferably 50 % is employed . The particle size of the TiB2 used may be in the range of is 8-20 microns preferably 11 microns , that of BN used rages from 1 to 20 microns , preferably 4 microns , that of AIN may be in the range of 5 to 20 microns , preferably 9 microns and that of Ni may be in the range of 1 to 10 microns , preferably 3 microns .
In a preferred embodiment of the invention the mill used may be planetary or centrifugal or tumbling ball The polar solvent employed as milling aid may be selected from acetone Jsopropnol or toluene etc , preferably toluene , and the milling may be effected preferably for 3 hours
The screening of the dried powders through a mesh preferably of 100 No. mesh to remove the agglomerates ,if any ,and to allow homogeneity
The compact / billet obtained may be cut into the sizes of 125x30x10 mm or 110 x18x8 mm as per the requirement
The details of the invention are provided in the Examples given below which are given by way of illustration only and therefore should not be construed to limit the scope of the invention

Example-1:
A composition consisting of powder mixture all by weight containing 34% boron nitride of particle size 4 microns 20% aluminium nitride of particle size 9 microns and 46% titanium diboride of particle size 11 microns were milled in acetone in a planetary ball mill . The composite was taken into an oven/ furnace for drying at 120°C to evaporate off the unused acetone. The dried powders were screened through a 100 No. mesh to remove agglomerates and to attain homogeneity. The dried powders were then filled in a graphite die of dia 100 mm and then covered with a graphite foil on all the four sides. The inductively heated hot press containing the graphite die was ramped at a rate of 800 K/hour and after reaching the hot pressing temperature of 2050°C, a pressure of the order of 50 MPa was applied and the compacts were held for 30 minutes at this temperature to allow the sintering to be completed. Then compact/billet was allowed to cool in the furnace and then ejected using an ordinary hydraulic press . Samples of size of 3x4x40mm were cut from the billet and characterized for density and 3 point bend strength tests as per ASTM procedures.
Example 2
A composition consisting of powder mixture containing all by weight 34% boron nitride of particle size 4 microns 20% aluminium nitride of particle size 9 microns and 46% titanium diboride of particle size 11 microns were milled in toluene in a planetary ball mill and the composite was taken into an oven/ furnace for drying at 120°C to evaporate off the unused toluene. The dried powders were screened through a 100 No. mesh to remove agglomerates and to attain homogeneity. The dried powders were then filled in a graphite die of dia 100 mm and then covered with a graphite foil on all the four sides. The inductively heated hot press containing the graphite die was ramped at a rate of 800 K/hour and after reaching the hot pressing temperature of 2050°C, a pressure of the order of 50 MPa was applied and the compacts were held for 30 minutes at this temperature to allow the sintering to be completed. Then compact/billet was allowed to cool in the furnace and then ejected using an ordinary hydraulic press . Samples of size of 3x4x40mm were cut from the

billet and characterized for density and 3 point bend strength tests as per ASTM procedures.
The results are shown in table below for both Example 1 and Example 2

It is clear from the above table that milling in toluene ie Example 2 not only prevents oxidation of powders like any other milling aid but also helps in improving density and bend strength as per the above observation. The improved bend strength has led to improvement in the life of boats by preventing any chances of cracking of boats under thermal stress.
Example- 3 :
A composition containing 50 % by weight of TiB2, with particle size of 11 microns , 30% by weight of BN with particle size of 4 microns, 20% by weight of AIN with particle size of 9 microns were taken and mixed together all simultaneously and then milled continuously for 3 hours and 15 minutes and then dried . The dried powders were then passed through a 100 mesh to prevent agglomeration and to aid in homogenisation of the mixture. The mixture was then filled in a graphite die of dia 100 mm and then covered with a graphite foil from all the four sides. The inductively heated hot press containing the graphite die was ramped at a rate of 800 K/hour and after reaching the hot pressing temperature of 2050°C, pressure of the order of 70 MPa was applied and the compacts were held for 30 minutes at this temperature to allow the sintering to get completed. Then compact/billet was allowed to cool in the

furnace and then ejected using an ordinary hydraulic press . Samples of size of 3x4x40mnri were cut from the billet and boats of the size 125 x 30 x 10mm were also cut and the metallization of Aluminium was carried out at the rate of 1.5gms/sq.in/minute on a bi-axially-oriented polypropylene film (8 microns)to measure the density and duration of metallisation till cracking was noted.
Example 4
A composition containing 50 % by weight of TiBa, with particle size of 11 microns , 30% by weight of BN with particle size of 4 microns, 20% by weight of AIN with particle size of 9 microns. BN and AIN were mixed together first and then milled in toluene medium using a planetary ball mill for a period of 3 hours. At the end of the 3 hours milling, the titanium di-boride powder was added to the milled BN & AIN powder and further milled together for a period of 15 minutes The dried powders were then passed through a 100 mesh to prevent agglomeration and to aid in homogenisation of the mixture. The mixture was then filled in a graphite die of dia 100 mm and then covered with a graphite foil from all the four sides. The inductively heated hot press containing the graphite die was ramped at a rate of 800 K/hour and after reaching the hot pressing temperature of 2050°C, pressure of the order of 70 MPa was applied and the compacts were held for 30 minutes at this temperature to allow the sintering to get completed. Then compact/billet was allowed to cool in the furnace and then ejected using an ordinary hydraulic press . Samples of size of 3x4x40mm were cut from the billet and boats of the size 125 x 30 x 10mm were also cut and the metallization of Aluminium was carried out at the rate of 1.5gms/sq.in/minute on a bi-axially-oriented polypropylene film (8 microns)to measure the density and duration of metallisation till cracking was noted
The obtained results are tabulated as under:


It is observed from the results that the addition of the electrically conducting material obtained by the process described in the Example 4 has resulted in better density and increased metallisation life.
Another improvement has been achieved by altering the way in which billets for preparation of boats were hot pressed.
Example-5
A composition containing 48.5% by weight of TiB2. with a particle size of 11 microns ,29% by weight of BN with a particle size of 4 microns ,19.5 % by weight of AIN with particle size of 9 microns and 3%Ni by weight with particle size of 3 microns were taken .. BN and AIN were mixed together first and then milled in toluene medium using a planetary ball mill for a period of 3 hours. At the end of the 3 hours milling, the titanium di-boride powder was added to the milled BN & AIN powder and further milled together for a period of 15 minutes. The dried powders were then passed through a 100 mesh to prevent agglomeration and to aid in homogenisation of the mixture. The mixture was then filled in a graphite die of dia 100 mm and then

covered with a graphite foil from all the four sides. The inductively heated hot press containing the graphite die was ramped at a rate of 800 K/hour and after reaching the hot pressing temperature of 2050°C, pressure of the order of 70 MPa was applied and the compacts were held for 30 minutes at this temperature to allow the sintering to get completed. Then compact/billet was allowed to cool in the furnace and then ejected using an ordinary hydraulic press .
Example 6
A composition containing 48.5% by weight of TiB2, with a particle size of 11 microns ,29% by weight of BN with a particle size of 4 microns ,19.5 % by weight of AIN with particle size of 9 microns and 3%Ni by weight with particle size of 3 microns were taken. BN and AIN were mixed together first and then milled in toluene medium using a planetary ball mill for a period of 3 hours. At the end of the 3 hours milling, the titanium di-boride powder was added to the milled BN & AIN powder and further milled together for a period of 15 minutes. The dried powders were then passed through a 100 mesh to prevent agglomeration and to aid in homogenisation of the mixture. The powders were green pressed at room temperature itself to a density of 60% of Theoretical Density in a hydraulic press .The mixture was then filled in a graphite die of dia 100 mm and then covered with a graphite foil from all the four sides. The inductively heated hot press containing the graphite die was ramped at a rate of 800 K/hour and after reaching the hot pressing temperature of 2050°C, pressure of the order of 70 MPa was applied and the compacts were held for 30 minutes at this temperature to allow the sintering to get completed. Then compact/billet was allowed to cool in the furnace and then ejected using an ordinary hydraulic press .


This clearly establishes that life of boats further improved by 16.6% by merely doing green pressing before hot pressing.
The Above results were compared with the properties of the products as mentioned in UK Patent No GB 2065713 published on 1 July 1981 .The results obtained were as under
% T-D- Density Resistivity Metallisation
Example 6 98 1.8 28 hours
Prior art 96 1.5 20 hours
GB Patent no 2065713
It is clear from the above six Examples that both mechanical and electrical properties can be improved by employing the suitable milling aid as well as by adding the conducting powder at the end than in the beginning and by green pressing. The metallisation duration is also improved due to improvement in density and bend strength, which causes the improvement in performance. As the powders are protected by the hydride as well as passivating layer of carbon the powders can be prevented from oxidation and can be stored for longer duration.
• ADVANTAGES OF THE INVENTION
• The boats of the present invention have better bend strength as compared to those available currently thereby giving rise to higher thermal shock resistance which prevents early cracking of the boat samples and eventually increases its life.
• The addition of the electrically conducting powder has resulted in improved density thereby causing an decrease in porosity to the boats which arrests crack propagation and increases its longevity.

The boats of the present invention have better throughput and cracking is not observed till 28 hours of continuous metallisation.
The process is simple and economical



WE CLAIM:
1. A process for the preparation of improved titanium boride based ceramic evaporation boats having improved electrical, thermal and mechanical properties and having longer life which are useful in the industries like packaging as wrappers, wood, capacitor films and for other decoration purposes which comprises
(i) mixing boron nitride in weight range of 25-50% and aluminium nitride in weight range of 5 to 25% and nickelin weight range of 1 to 5% in a mill with polar solvents as milling aid for a period ranging 1-10
(ii) adding the resultant mixture to titanium diboride powder 30%-60% during the period ranging from 15 to 45 minutes , taking care not to allow the vigorous milling of these powders and at the same time allowing the conducting powders to effectively smear on the non conducting powders.
(iii) drying the resulting powders in an oven / furnace at a temperature in the range of 100 °C-140 °C to evaporate off the remaining solvent
(iv) screening the dried powders through a 100 No. -200 No to remove agglomerates ,if any ,and to allow homogeneity.
(v) filling the dried powders in a graphite die of dia 75-200 mm lined with graphite foil and pressing them at room temperature by Green pressing to 60%of its theoretical density

vi heating the die inductively in a hot press which is ramped initially at a rate of 600 -1000 K/hour and after reaching the hot pressing temperature in the range of 1850-2100 C, applying a pressure of the order of 30-70 MPa , holding the resulting compacts for a period in the range of 15-45 minutes at this temperature to allow the sintering to complete
(vii) cooling the resultant compact /billet in the furnace to room temperature ,
ejecting them using an ordinary hydraulic press and
(vii) cutting combact / billet to the desired size to obtain the boats .
2. A process as claimed in claim 1 wherein the powder mixture used contains 48.5% by weight, titanium diboride 29.0 %by weight , boron nitride 19.5% by weight, aluminium nitride and Ni 3.0% by weight
3. A process as claimed in claims 1 & 2 wherein the powder mixture used contains boron nitride 34% by weight , aluminium nitride 20% by weight , by weight and titanium diboride 46 %

4. A process as claimed in claims 1 to 3 wherein the particle size of the TJB2 used is in the range of 8-20 microns , ,that of BN used rages from 1 to 20 microns , ,that of AIN ranges from 5 to 20 microns , and that of Ni ranges from 1 to 10 microns ,
5. A process as claimed in claim 4 wherein the particle size of the TiB2 used is 11 microns, that of BN used is 4 microns, that of AIN used is 9 microns and that of Ni used is 3 microns .
6.A process as claimed in claims 1 to 5 wherein the mill used is planetary or centrifugal or tumbling ball mill
7. A process as claimed in claimed in claims 1 to 6 wherein the polar solvent such as acetone , isopropnol, toluene and the like ,preferably toluene is used

8.A process as claimed in claims 1 to 7 wherein the milling is effected for 3 hours
9. A process as claimed in claims 1 to 8 wherein the screening of the dried powders is effected through a 100 No. -200 mesh
10 A process for the preparation of improved titanium boride based ceramic evaporation boats having improved electrical, thermal and mechanical properties and have longer life which are useful in the industries like packaging, wood, capacitor as wrappers and for decoration purposes substantially as herein deschbed with reference to the Examples
11.Improved titanium boride based ceramic evaporation boats having improved electrical, thermal and mechanical properties and have longer life which are useful in the industries like packaging, wood, capacitor as wrappers and for decoration purposes prepared by the process as claimed in claims 1 to 10


Documents:

882-che-2003-abstract.pdf

882-che-2003-claims duplicate.pdf

882-che-2003-claims original.pdf

882-che-2003-correspondence others.pdf

882-che-2003-correspondence po.pdf

882-che-2003-description complete duplicate.pdf

882-che-2003-description complete original.pdf

882-che-2003-form 1.pdf

882-che-2003-form 19.pdf


Patent Number 201511
Indian Patent Application Number 882/CHE/2003
PG Journal Number 15/2008
Publication Date 11-Apr-2008
Grant Date 01-Mar-2007
Date of Filing 31-Oct-2003
Name of Patentee INTERNATIONAL ADVANCED RESEARCH CENTRE FOR POWDER METALLURGY AND NEW MATERIALS (ARCI)
Applicant Address GOVT.OF INDIA, OPP: BALAPUR VILLAGE, RR DISTRICT, BALAPUR P.O., HYDERABAD - 500 005.
Inventors:
# Inventor's Name Inventor's Address
1 SUBBARATNAM KUMAR INTERNATIONAL ADVANCED RESEARCH CENTRE FOR POWDER METALLURGY AND NEW MATERIALS (ARCI)GOVT.OF INDIA, OPP: BALAPUR VILLAGE, RR DISTRICT, BALAPUR P.O., HYDERABAD - 500 005.
2 MUKTA MANI PUNJ M/S SUPERVAC OILS, B-21, FLATTED FACTORY COMPLEX, JHANDEWALAN, NEW DELHI-55
PCT International Classification Number C014B 35/58
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA