Title of Invention	A LOW COEFFICIENT BETA-SPODUMENE BASED CERAMIC PRODUCT
Abstract	A spodumene and clay based ceramic product and a glaze composition for manufacture of ceramic kitchen-ware The present invention relates to a ceramic product and a glazing composition - both based on spodumene - that eliminate the shortcomings of convention ceramic products in manufacture of kitchen-ware. The ceramic product and the glazing composition of the present invention offer low thermal expansion coefficient to withstand repeated thermal shocks, good elasticity, low cost of manufacture from a blend of pottery clays, freedom from toxic substances leaching into food being cooked and advantages of life-sustaining substances.

Title of Invention

A LOW COEFFICIENT BETA-SPODUMENE BASED CERAMIC PRODUCT

Abstract

A spodumene and clay based ceramic product and a glaze composition for manufacture of ceramic kitchen-ware The present invention relates to a ceramic product and a glazing composition - both based on spodumene - that eliminate the shortcomings of convention ceramic products in manufacture of kitchen-ware. The ceramic product and the glazing composition of the present invention offer low thermal expansion coefficient to withstand repeated thermal shocks, good elasticity, low cost of manufacture from a blend of pottery clays, freedom from toxic substances leaching into food being cooked and advantages of life-sustaining substances.

Full Text	FORM 2 THE PATENT ACT 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See section 10 and rule 13) 1. TITLE OF THE INVENTION : 'A spodumene and clay based ceramic product and a glaze composition for manufacture of ceramic kitchenware' 2. APPLICANT (a) NAME : Bharat Gidwani (b) NATIONALITY : Indian (c) ADDRESS : 51, Lullanagar, Krishna Kunj, Pune - 411040, M.S. India 3. PREAMBLE TO THE DESCRIPTION COMPLETE SPECIFICATION The following specification particularly describes the invention and the manner in which it is to be performed Title of the Invention: A spodumene and clay based ceramic product and a glaze composition for manufacture of ceramic kitchenware Field of the Invention: This invention relates to the field of manufacturing ceramic products having flame ware applications and more particularly to the field of manufacturing a ceramic product based on beta-spodumene that has a low thermal expansion coefficient to withstand successive thermal shocks, a good plasticity for shaping different kitchenware and a non-toxic glaze and is thermal energy-efficient. Background of the Invention: Following prior works of art are cited for comparison with the present invention to draw out their dissimilarities and drawbacks in comparison with the present invention: EP 1840093 (Al) - This prior work relates to production of glass-ceramic material by ceramming precursor glass and using therewith fining agents. It does not employ a blend of clays and is therefore different from the present invention. US Patent 6515263 B2 - This prior work relates to multi-layered glass ceramic body that is claimed to have keatite mixed crystals as the predominant crystal phase. It is different both from the corresponding beta-spodumene solid solution of the ceramic product of the present invention and in terms of no use of blend of clays. US Patent 3582371 - It relates to glass ceramic articles, based upon compositions made of oxides of lithium, magnesium, aluminum and silica and using titanium dioxide as a nucleating agent. This work of art is different from the present invention in terms of use of metal oxides and non-use of blend of clays in the manufacture of ceramic product. US Patent 4140645 - This prior work relates to production of glass ceramic compositions containing ferri-magnetic crystal phase, which is different from the corresponding Beta-spodumene solid solution of the present invention. US Patent 4287260 - This prior work relates to a glaze composition containing cordierite crystals, which are different from the Beta-spodumene solid solution, predominantly contained in the ceramic product of the present invention. US Patent 2919995 - It describes a ceramic product, produced from finely divided petalite and one or more compounds of alkaline earth metals. The cited prior work is different in terms of raw material mix. The prior work uses petalite and alkaline earth metal compound, while the present invention relies upon a raw material mix of spodumene and a blend of clays. The present invention is different from the cited prior work in terms of the raw material mix. US Patent 4360567 - The prior work relates to surface crystallization to impart ease in cleaning surface layer that is essentially made of magnesium oxide-based and/or calcium oxide-based and/or strontium-based and/or barium oxide-based crystals. The present invention is different from the cited prior work in terms of the raw material mix used for production of ceramic product. US Patent 6261985 B1 - This prior work describes production of a ceramic material from a raw material mix comprising talc, kaolinite, refractory clay, cordierite, mullite, petalite and 5-10% by weight of oxides of zirconium, cobalt, titanium, silicon dioxide, ferric oxide. The prior work is different from the present invention in terms of the raw material mix, the latter using beta-spodumene, petalite and a blend of clays. No prior work of art is found having the features of the present invention. Only a few products- having a good elasticity and low thermal co-efficient of expansion - are available because of low cost of inputs or of manufacturing process involved. Some products are made by focusing a composition into glass, pouring the glass into a mould and shaping a crystalline product by crystal nucleation and growth under highly controlled conditions. The disadvantage of these products is that the manufacturing processes require extensive manufacturing facilities that are hugely capital-intensive. Cooking utensils available on a large scale in market are non-stick, polymer-coated aluminum vessels. They are hazardous due to leaching of polymer into food and to contamination and toxification of food due to exposure to, highly reactive aluminum. Stainless steel vessels tend to burn food and leach nickel into food. They are unsafe due to these characteristics. Objects of the Invention: A primary object of the present invention is to provide for kitchen ware manufacture a ceramic product of low thermal expansion coefficient and which is capable of withstanding repeated thermal shocks due to gas stoves and gas-ovens heating followed by freezer cooling. Another object of the present invention is to provide a ceramic product, capable of fabricating kitchen ware of all shapes and size due to its good elasticity. Another object of the present invention is to manufacture a ceramic product from relatively inexpensive blend of pottery making clays. Another object of the present invention is to utilize affordable pottery processes to produce a ceramic product having kitchen ware application. Another object of the present invention is to prepare a ceramic product of kitchen ware application that has no toxic substances leaching into food items being cooked in kitchen ware. Another object of the present invention is to prepare a non-toxic glaze, free of any substances leaching into food items being cooked. Another object of the present invention is to prepare a glaze that has life-sustaining and beneficial ingredients. Lastly, another object of the present invention is to provide a friendly cooking utensil - non-toxic and life sustaining, which is energy-efficient, by utilizing less fuel for cooking and by conserving heat of hot food for longer durations, after cooking is over. Summary of the Invention: A beta-spodumene based ceramic product (100), having a low coefficient of thermal' expansion of 10 x 10'7 to 25 x 10"7 per degree celcius is comprised of 90% and more by volume of beta-spodumene solid solution and 10% or less by volume of mullite and prepared by sintering within a range of cone 5 to cone 10 an un-sintered mixture (30) of spodumene (10) and blend of clays (20). Detailed Description of the Invention: A ceramic product (100) is prepared by sintering a mixture (30) comprising following constituents, namely: (i) spodumene (10), in 40%-60% by weight of un-sintered mixture (30); (ii) clay blend (20), in 40%-60% by weight of un-sintered mixture (30). The constituents of the mix are sintered at 2235 degree C- 2300 degree C temperature (cone 9 to cone 10) such that the sintered mix has a composition of 90% by weight beta- spodumene solid solution and mullite 10% or less by weight and the sintered mix has ♦ 1 1 thermal expansion coefficient of from 10x10" to 25 x 10 per degree celcius. The blend of clay (20) has following composition (i) china clay 15-20% by weight of un-sintered mixture (30); (ii) ball clay 15-20% by weight of un-sintered mixture (30); (iii) fire clay 15-20% by weight of un-sintered mixture (30). Kitchenware are exteriorly first coated with an uniform coat of ceramic product (100) and are interiorly coated with an uniform coat of glaze (150), which has following composition: (1) spodumene 50-90% by weight of glaze (150); (2) mix of china clay, 10-30% by weight of glaze (150); fire clay and ball clay (3) mix of ferrous oxide, 10-30% by weight of glaze (150) zinc oxide, titanium dioxide and stannous dioxide Kitchenware - of any shape and size - are heated to cone 5 for sintering blaze coating, are then cooled to ambient temperature and packed for dispatch. Following conditions ensure ideal working of the invention: (a) spodumene should be chemical grade, 200 mesh particle size (b) temperature for preparing ceramic product (100) should be for cone 9 cone 10 range. Claims: I claim 1. A beta-spodumene based ceramic product (100), having a low coefficient of thermal expansion of 10 x 10" to 25 x 10"7 per degree celcius, comprised of 90% and more by volume of beta-spodumene solid solution and 10% or less by volume of mullite and prepared by sintering in a furnace (90) within a range of cone 5 to cone 10 an un-sintered and blended mixture (30) of spodumene (10) and blend of clays (20). 2. A beta-spodumene based ceramic product (100) as claimed in claim 1, wherein said un-sintered mixture (30) is comprised of spodumene (10) in 40% - 60% by weight quantity and blend of clays (20) in 40% - 60% by weight quantity. 3. A beta-spodumene based ceramic product (100) as claimed in claim 1, wherein said blend of clays (20) is a mixture of china clay (22) in a quantity measuring 15%-20% by weight of said un-sintered mixture (30), ball clay (24) in a quantity measuring 15%-20% by weight of said un-sintered mixture (30) and fire clay (26) in a quantity measuring 15%-20% by weight of said un-sintered mixture (30). 5. A beta-spodumene based ceramic product (100) as cfaimed in claim 1, wherein said spodumene (10) is of chemical grade and 200 mesh particle size. 6. A beta-spodumene based ceramic product (100) as claimed in claim 1, which is applied in a base coat as a ceramic body (105) to kitchenware (110). 7. A spodumene based glaze composition (150) for application as top coat (155) to said ceramic body (105), said glaze composition (150) comprising spodumene (10) in 50% to 90% by weight quantity, a mix (120) of clay (22), ball clay (24) and fire clay (26) in 10%-30% by weight quantity and a mix of ferrous oxide (132), zinc oxide (134), titanium dioxide (136) and stannous oxide (138) in 10%-30% by weight quantity. 4. A beta-spodumene based ceramic product (100) as claimed in claim 1, wherein said un-sintered mixture (30) is preferably sintered in said furnace (90) within cone 9 to cone 10 range.

Full Text

FORM 2
THE PATENT ACT 1970
(39 of 1970) &
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION : 'A spodumene and clay based ceramic product and a glaze composition for manufacture of ceramic kitchenware'
2. APPLICANT
(a) NAME : Bharat Gidwani
(b) NATIONALITY : Indian
(c) ADDRESS : 51, Lullanagar, Krishna Kunj, Pune - 411040,
M.S. India

3. PREAMBLE TO THE DESCRIPTION
COMPLETE SPECIFICATION The following specification
particularly describes the invention and the manner in which it is to be performed
Title of the Invention:
A spodumene and clay based ceramic product and a glaze composition for manufacture of ceramic kitchenware
Field of the Invention:
This invention relates to the field of manufacturing ceramic products having flame ware applications and more particularly to the field of manufacturing a ceramic product based on beta-spodumene that has a low thermal expansion coefficient to withstand successive thermal shocks, a good plasticity for shaping different kitchenware and a non-toxic glaze and is thermal energy-efficient.
Background of the Invention:
Following prior works of art are cited for comparison with the present invention to draw out their dissimilarities and drawbacks in comparison with the present invention:
EP 1840093 (Al) - This prior work relates to production of glass-ceramic material by ceramming precursor glass and using therewith fining agents. It does not employ a blend of clays and is therefore different from the present invention.
US Patent 6515263 B2 - This prior work relates to multi-layered glass ceramic body that is claimed to have keatite mixed crystals as the predominant crystal phase. It is different both from the corresponding beta-spodumene solid solution of the ceramic product of the present invention and in terms of no use of blend of clays.
US Patent 3582371 - It relates to glass ceramic articles, based upon compositions made of oxides of lithium, magnesium, aluminum and silica and using titanium dioxide as a
nucleating agent. This work of art is different from the present invention in terms of use of metal oxides and non-use of blend of clays in the manufacture of ceramic product.
US Patent 4140645 - This prior work relates to production of glass ceramic compositions containing ferri-magnetic crystal phase, which is different from the corresponding Beta-spodumene solid solution of the present invention.
US Patent 4287260 - This prior work relates to a glaze composition containing cordierite crystals, which are different from the Beta-spodumene solid solution, predominantly contained in the ceramic product of the present invention.
US Patent 2919995 - It describes a ceramic product, produced from finely divided petalite and one or more compounds of alkaline earth metals. The cited prior work is different in terms of raw material mix. The prior work uses petalite and alkaline earth metal compound, while the present invention relies upon a raw material mix of spodumene and a blend of clays. The present invention is different from the cited prior work in terms of the raw material mix.
US Patent 4360567 - The prior work relates to surface crystallization to impart ease in cleaning surface layer that is essentially made of magnesium oxide-based and/or calcium oxide-based and/or strontium-based and/or barium oxide-based crystals. The present invention is different from the cited prior work in terms of the raw material mix used for production of ceramic product.
US Patent 6261985 B1 - This prior work describes production of a ceramic material from a raw material mix comprising talc, kaolinite, refractory clay, cordierite, mullite, petalite and 5-10% by weight of oxides of zirconium, cobalt, titanium, silicon dioxide, ferric oxide. The prior work is different from the present invention in terms of the raw material mix, the latter using beta-spodumene, petalite and a blend of clays.
No prior work of art is found having the features of the present invention.
Only a few products- having a good elasticity and low thermal co-efficient of expansion - are available because of low cost of inputs or of manufacturing process involved. Some products are made by focusing a composition into glass, pouring the glass into a mould and shaping a crystalline product by crystal nucleation and growth under highly controlled conditions.
The disadvantage of these products is that the manufacturing processes require extensive manufacturing facilities that are hugely capital-intensive.
Cooking utensils available on a large scale in market are non-stick, polymer-coated aluminum vessels. They are hazardous due to leaching of polymer into food and to contamination and toxification of food due to exposure to, highly reactive aluminum.
Stainless steel vessels tend to burn food and leach nickel into food. They are unsafe due to these characteristics.
Objects of the Invention:
A primary object of the present invention is to provide for kitchen ware manufacture a ceramic product of low thermal expansion coefficient and which is capable of withstanding repeated thermal shocks due to gas stoves and gas-ovens heating followed by freezer cooling.
Another object of the present invention is to provide a ceramic product, capable of fabricating kitchen ware of all shapes and size due to its good elasticity.
Another object of the present invention is to manufacture a ceramic product from relatively inexpensive blend of pottery making clays.
Another object of the present invention is to utilize affordable pottery processes to produce a ceramic product having kitchen ware application.
Another object of the present invention is to prepare a ceramic product of kitchen ware application that has no toxic substances leaching into food items being cooked in kitchen ware.
Another object of the present invention is to prepare a non-toxic glaze, free of any substances leaching into food items being cooked.
Another object of the present invention is to prepare a glaze that has life-sustaining and beneficial ingredients.
Lastly, another object of the present invention is to provide a friendly cooking utensil - non-toxic and life sustaining, which is energy-efficient, by utilizing less fuel for cooking and by conserving heat of hot food for longer durations, after cooking is over.
Summary of the Invention:
A beta-spodumene based ceramic product (100), having a low coefficient of thermal' expansion of 10 x 10'7 to 25 x 10"7 per degree celcius is comprised of 90% and more by
volume of beta-spodumene solid solution and 10% or less by volume of mullite and prepared by sintering within a range of cone 5 to cone 10 an un-sintered mixture (30) of spodumene (10) and blend of clays (20).
Detailed Description of the Invention:
A ceramic product (100) is prepared by sintering a mixture (30) comprising following constituents, namely:
(i) spodumene (10), in 40%-60% by weight of un-sintered mixture (30);
(ii) clay blend (20), in 40%-60% by weight of un-sintered mixture (30).
The constituents of the mix are sintered at 2235 degree C- 2300 degree C temperature (cone 9 to cone 10) such that the sintered mix has a composition of 90% by weight beta-
spodumene solid solution and mullite 10% or less by weight and the sintered mix has
♦ 1 1 thermal expansion coefficient of from 10x10" to 25 x 10 per degree celcius.
The blend of clay (20) has following composition
(i) china clay 15-20% by weight of un-sintered mixture (30);
(ii) ball clay 15-20% by weight of un-sintered mixture (30);
(iii) fire clay 15-20% by weight of un-sintered mixture (30).
Kitchenware are exteriorly first coated with an uniform coat of ceramic product (100) and are interiorly coated with an uniform coat of glaze (150), which has following composition:
(1) spodumene 50-90% by weight of glaze (150);
(2) mix of china clay, 10-30% by weight of glaze (150); fire clay and ball clay
(3) mix of ferrous oxide, 10-30% by weight of glaze (150) zinc oxide, titanium
dioxide and stannous dioxide Kitchenware - of any shape and size - are heated to cone 5 for sintering blaze coating, are then cooled to ambient temperature and packed for dispatch.
Following conditions ensure ideal working of the invention:
(a) spodumene should be chemical grade, 200 mesh particle size
(b) temperature for preparing ceramic product (100) should be for cone 9 cone 10 range.
Claims:
I claim
1. A beta-spodumene based ceramic product (100), having a low coefficient of thermal expansion of 10 x 10" to 25 x 10"7 per degree celcius, comprised of 90% and more by volume of beta-spodumene solid solution and 10% or less by volume of mullite and prepared by sintering in a furnace (90) within a range of cone 5 to cone 10 an un-sintered and blended mixture (30) of spodumene (10) and blend of clays (20).
2. A beta-spodumene based ceramic product (100) as claimed in claim 1, wherein said un-sintered mixture (30) is comprised of spodumene (10) in 40% - 60% by weight quantity and blend of clays (20) in 40% - 60% by weight quantity.
3. A beta-spodumene based ceramic product (100) as claimed in claim 1, wherein said blend of clays (20) is a mixture of china clay (22) in a quantity measuring 15%-20% by weight of said un-sintered mixture (30), ball clay (24) in a quantity measuring 15%-20% by weight of said un-sintered mixture (30) and fire clay (26) in a quantity measuring 15%-20% by weight of said un-sintered mixture (30).
5. A beta-spodumene based ceramic product (100) as cfaimed in claim 1, wherein said spodumene (10) is of chemical grade and 200 mesh particle size.
6. A beta-spodumene based ceramic product (100) as claimed in claim 1, which is applied in a base coat as a ceramic body (105) to kitchenware (110).
7. A spodumene based glaze composition (150) for application as top coat (155) to said ceramic body (105), said glaze composition (150) comprising spodumene (10) in 50% to 90% by weight quantity, a mix (120) of clay (22), ball clay (24) and fire clay (26) in 10%-30% by weight quantity and a mix of ferrous oxide (132), zinc oxide (134), titanium dioxide (136) and stannous oxide (138) in 10%-30% by weight quantity.
4. A beta-spodumene based ceramic product (100) as claimed in claim 1, wherein said
un-sintered mixture (30) is preferably sintered in said furnace (90) within cone 9 to
cone 10 range.

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Patent Number

271765

Indian Patent Application Number

3003/MUM/2009

PG Journal Number

10/2016

Publication Date

04-Mar-2016

Grant Date

03-Mar-2016

Date of Filing

29-Dec-2009

Name of Patentee

BHARAT GIDWANI

Applicant Address

51,LULLANAGAR, KRISHNA KUNJ, PUNE-411 040, M.S.INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	BHARAT GIDWANI	51,LULLANAGAR, KRISHNA KUNJ, PUNE-411 040, M.S.INDIA.

PCT International Classification Number

A47J36/04,A47J27/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA