Abstract: The present invention relates to boron-containing compositions. The invention relates to comminuted, heterogeneous boron-containing compositions which are obtainable by a process which comprises heating to a temperature sufficiently high that calcination occurs but insufficient for the formation of a homogeneous melt a mixture comprising components capable, under the conditions of heating, of forming the oxides B2O3 and SiO2 and optionally Al2O3, Na2O and/or CaO in proportions such that the relative percentages by weight of the said oxides, based on the total weight of said oxides, are as follows: 5 to 35% B2O3; 10 to 65% SiO2; 0 to 35% Al2O3; and up to 20% Na2O and/or up to 50% CaO; with the proviso that the said B2O3 content is not 10 to 18%, when the other contents are as follows: 40 to 65% SiO2, 17 to 32% Al2O3 4 to 9% Na2O, and 0 to 10% CaO, and then comminuting the resulting composition.

Abstract: This invention relates to boron-containing compositions for use in glaze compositions. There is provided a boron-containing composition for use in glaze production, which composition is obtainable by a process which comprises heating to a temperature sufficiently high that calcination occurs but insufficient for the formation of a homogeneous melt a mixture comprising components capable, under the conditions of heating, of forming the oxides B2O3, SiO2, Al2O3, Na2O and optionally CaO in proportions such that the relative percentages by weight of the said oxides, based on the total weight of the said oxides, are as follows: 10 to 18% B2O3, 40 to 65% SiO2, 17 to 32% Al2O3, 4 to 9% Na2O, and 0 to 10% CaO. The boron-containing compositions according to the present invention may be used in glaze compositions, suitably frit-free or boron-free frit-containing glaze compositions.

Abstract: The present invention relates to boron-containing compositions. The invention relates to comminuted, heteroge-neousboron-containing compositions which are obtainable by a process which comprises heating to a temperature sufficiently high that calcination occurs but insufficient for the formation of a homogeneous melt a mixture comprising components capable, under the conditions of heating, of forming the oxides B2O3 and SiO2 and optionally Al2O3, Na2O and/or CaO in proportions such that the relative percentages by weight of the said oxides, based on the total weight of said oxides, are as follows: 5 to 35% B2O3; 10 to 65% SiO2; 0 to 35% Al2O3; and up to 20% Na2O and/or up to 50% CaO; with the proviso that the said B2O3 content is not 10 to 18%, when the other contents are as follows: 40 to 65% SiO2, 17 to 32% Al2O3 4 to 9% Na2O, and 0 to 10% CaO, and then comminuting the resulting composition.

Abstract: This invention relates to boron-containing compositions for use in glaze compositions. There is provided a boron-containing composition for use in glaze production, which composition is obtainable by a process which comprises heating to a temperature sufficiently high that calcination occurs but insufficient for the formation of a homogeneous melt a mixture comprising components capable, under the conditions of heating, of forming the oxides B2O3, SiO2, Al2O3, Na2O and optionally CaO in proportions such that the relative percentages by weight of the said oxides, based on the total weight of the said oxides, are as follows: 10 to 18% B2O3, 40 to 65% SiO2, 17 to 32% Al2O3, 4 to 9% Na2O, and 0 to 10% CaO. The boron-containing compositions according to the present invention may be used in glaze compositions, suitably frit-free or boron-free frit-containing glaze compositions.