Cookson Group Plc

Tam Ceramics, Inc.

John F Clifford

Ivan Wozniak

Christopher Hood

John Bultitude

Peter John Smith

Timothy P Beales

Fiona C Morrison

A glass composition which is essentially free from lead and cadium comprises, in mole percent, SiO.sub.2 :35 to 75%, Bi.sub.2 O3:0.1 to 15%, Al.sub.2 O.sub.3 :0.1 to 10%, B.sub.2 O.sub.3 :1 to 30%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O:5 to 30%, ZrO.sub.2 :0.1 to 10%, and certain other optional ingredients, with the proviso that BaO and ZnO are not contained in an amount of more than 2 mole percent. These glass compositions can be used as fluxes for mixing with pigments to provide compositions for the decoration of ceramic materials and/or glass.

Glass compositions

Glaze composition comprises 45 to 75% of SioO.sub.2, 0.1 to below 5% of Bi.sub.2 O.sub.3, 0.1 to 20% of Al.sub.2 O.sub.3 to 20% of B.sub.2 O.sub.3, at least one of CaO, MgO, SrO, BaO or Zno in an amount of 2 to 22%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O in an amount of 1 to 10%, at least one of La.sub.2 O.sub.3, MoO.sub.3 or WO.sub.3 in an amount of 0.1 to 10% and certain other optional ingredients, all percentages being percentages by weight based on the total weight of the glaze composition, the glaze composition having a firing temperature of 950.degree. to 1250.degree. C., and having a coefficient of thermal expansion of 50 to 100.times.10.sup.-7 /.degree.C.

Glaze compositions

A method of sintering a ceramic material composed of alkaline earth metal titanate and mixtures thereof, wherein the ceramic material is mixed with a sintering aid of a mixture of a mixed metal oxide of the formula BaCuO.sub.2 and an oxide selected from the group consisting of tungsten trioxide, molybdenum trioxide and mixtures thereof, and sintering the mixture.

Sintering aid

Glaze composition for use on bone china and fine china which is essentially free from lead and cadium comprises, by weight, SiO.sub.2 : 35 to 60%, Bi.sub.2 O.sub.3 : 5 to 45%, Al.sub.2 O.sub.3 :5 to 20%, B.sub.2 O.sub.3 : 1 to 15%, at least one of CaO, MgO, SrO or BaO: 2 to 20%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O: 1 to 10%, and certain other optional ingredients, with the proviso that BaO is not contained in an amount of more than 2% by weight.

Glaze composition for use on bone china and fine china which is essentially free from lead and cadium comprises, by weight, SiO.sub.2 :35 to 60%, Bi.sub.2 O.sub.3 :5 to 45%, Al.sub.2 O.sub.3 :5 to 20%, B.sub.2 O.sub.3 :1 to 15%, at least one of CaO, MgO, SrO or BaO:2 to 20%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O:1 to 10%, and certain other optional ingredients, with the proviso that BaO is not contained in an amount of more than 2% by weight.

A pigment which comprises crystallites of iron oxide having an average particle size of less than 100 nanometers doped with from 10% to 80% by weight of aluminium as Al.sup.3+ based on the weight of iron, having the general formula (Al.sub.x Fe.sub.2-x)O.sub.3, where x=0.34 to 1.24 and having an orange color with the following color measurements:

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Sydenham, United Kingdom

John F Clifford