Low thermal expansion filler, method for preparing the same and glass composition
AssigneeToagosei Co., Ltd.
InventorKoji Sugiura
Life of this patent
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Abstract
An object of the present invention is to provide a low thermal expansion filler for low thermal expansion glasses which has a low coefficient of thermal expansion and exhibits superior flowability in a molten state, and a glass composition containing the same. It has been found that a low thermal expansion filler composed of a hexagonal zirconium phosphate powder where a specific particle size of 0.8 μm to 50 μm is 95% or more on a volume basis has excellent low thermal expansion property and excellent flowability, and a glass composition containing the filler has been accomplished.
Claims7
A method for preparing a low thermal expansion filler, comprising:
- dispersing a zirconium carbonate powder containing hafnium in an aqueous solution containing at least one ion selected from an alkali metal ion, an alkaline earth metal ion and an ammonium ion, and a phosphate ion;
- and
- aging the dispersion while wet-heating;
- and
- subsequently dry-heating the dispersion to give a low thermal expansion filler,
- wherein the low thermal expansion filler comprising a hexagonal zirconium phosphate powder represented by Formula (1) below, wherein a particle size of 0.8 μm to 50 μm is 95% or more on a volume basis with respect to the total particles,
- MaZrbHfc(PO4)3.nH2O (1)
- wherein M represents at least one ion selected from the group consisting of an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion;
- a, b and c are values satisfying 1.75<b+c<2.25, and a+4(b+c)=9, in a case where M is monovalent, 2a+4(b+c)=9 in a case where M is divalent;
- a and b are each a positive number, c is a positive number, and n is zero or a positive number of 2 or less.
A method for preparing a glass composition comprising:
- dispersing a zirconium carbonate powder containing hafnium in an aqueous solution containing at least one ion selected from an alkali metal ion, an alkaline earth metal ion and an ammonium ion, and a phosphate ion;
- aging the dispersion while wet-heating to give a low thermal expansion filler;
- and
- mixing a glass powder and the low thermal expansion filler;
- wherein the low thermal expansion filler comprises a hexagonal zirconium phosphate powder represented by Formula (1) below, wherein a particle size of 0.8 μm to 50 μm is 95% or more on a volume basis with respect to the total particles,
- MaZrbHfc(PO4)3.nH2O (1)
- wherein M represents at least one ion selected from the group consisting of an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion;
- a, b and c are values satisfying 1.75<b+c<2.25, and a+4(b+c)=9, in a case where M is monovalent, 2a+4(b+c)=9 in a case where M is divalent;
- a and b are each a positive number, c is a positive number, and n is zero or a positive number of 2 or less.
A method for preparing a low thermal expansion filler, comprising:
- dispersing a zirconium carbonate powder containing hafnium in an aqueous solution containing at least one ion selected from an alkali metal ion, an alkaline earth metal ion and an ammonium ion, and a phosphate ion;
- and
- aging the dispersion while wet-heating to give a low thermal expansion filler,
- wherein the low thermal expansion filler comprising a hexagonal zirconium phosphate powder represented by Formula (1) below, wherein a particle size of 0.8 μm to 50 μm is 95% or more on a volume basis with respect to the total particles,
- MaZrbHfc(PO4)3.nH2O (1)
- wherein M represents at least one ion selected from the group consisting of an alkali metal ion, an alkaline earth metal ion, an ammonium ion and a hydrogen ion;
- a, b and c are values satisfying 1.75<b+c<2.25, and a+4(b+c)=9, in a case where M is monovalent, 2a+4(b+c)=9 in a case where M is divalent;
- a and b are each a positive number, c is a positive number, and n is zero or a positive number of 2 or less.
Dependencies are inferred from the claim text.