초록 ▼

Inorganic fibers having the composition: 10≤Al2O3≤50 mol %; 2≤K2O≤40 mol %; 30≤SiO2≤70 mol %; and in which SiO2+Al2O3+K2O=80 mol % can be protected against surface crystallization of kalsilite by: including an amount of a nucleation promoting component effective to promote bulk crystallization in th

Inorganic fibers having the composition: 10≤Al2O3≤50 mol %; 2≤K2O≤40 mol %; 30≤SiO2≤70 mol %; and in which SiO2+Al2O3+K2O=80 mol % can be protected against surface crystallization of kalsilite by: including an amount of a nucleation promoting component effective to promote bulk crystallization in the glass; and/or providing on at least part of their surface, potassium scavenging materials.

대표청구항 ▼

1. Inorganic fibres formed as a glass having a composition comprising:— 10≤Al2O3≤50 mol %;12≤K2O≤40 mol %;30≤SiO2≤70 mol %; andan amount of a nucleation promoting component effective to promote bulk crystallisation in the glass; in which SiO2+Al2O3+K2O ≥80 mol % and with the total constituents not e

1. Inorganic fibres formed as a glass having a composition comprising:— 10≤Al2O3≤50 mol %;12≤K2O≤40 mol %;30≤SiO2≤70 mol %; andan amount of a nucleation promoting component effective to promote bulk crystallisation in the glass; in which SiO2+Al2O3+K2O ≥80 mol % and with the total constituents not exceeding 100 mol %. 2. Inorganic fibres, as claimed in claim 1 in which 20≤Al2O3≤35 mol %. 3. Inorganic fibres, as claimed in claim 2 in which 23≤Al2O3≤33 mol %. 4. Inorganic fibres, as claimed in claim 3 in which 25≤Al2O3≤31 mol %. 5. Inorganic fibres, as claimed in claim 1 in which 15≤K2O≤30 mol %. 6. Inorganic fibres, as claimed in claim 5, in which 17≤K2O≤25 mol %. 7. Inorganic fibres, as claimed in claim 6, in which 20≤K2O≤24 mol %. 8. Inorganic fibres, as claimed in claim 1, in which 35≤SiO2≤60 mol %. 9. Inorganic fibres, as claimed in claim 8 in which 40≤SiO2≤50 mol %. 10. Inorganic fibres, as claimed in claim 9 in which 40≤SiO2≤45 mol %. 11. Inorganic fibres, as claimed in claim 1, in which SiO2+Al2O3+K2O≥85 mol %. 12. Inorganic fibres, as claimed in claim 11, in which SiO2+Al2O3+K2O ≥90 mol. 13. Inorganic fibres, as claimed in claim 12, in which SiO2+Al2O3+K2O ≥95 mol %. 14. Inorganic fibres, as claimed in claim 1, in which the composition further comprises magnesia. 15. Inorganic fibres, as claimed in claim 14 in which 0.2≤MgO ≤5 mol %. 16. Inorganic fibres, as claimed in claim 15 in which 0.5≤MgO ≤4 mol %. 17. Inorganic fibres, as claimed in claim 16 in which 1≤MgO ≤3 mol %. 18. Inorganic fibres, as claimed in claim 1, in which the component capable of promoting bulk crystallisation is or includes zirconia, ceria, titania, phosphate, or mixtures thereof. 19. Inorganic fibres, as claimed in claim 18, in which the component capable of promoting bulk crystallisation is or includes zirconia. 20. Inorganic fibres, as claimed in claim 19, in which:— 3≤ZrO2≤10 mol %. 21. Inorganic fibres, as claimed in claim 20, in which:— 3.5 mol %≤ZrO2≤10 mol %. 22. Inorganic fibres, as claimed in claim 20, in which:— ZrO2≤9 mol %. 23. Inorganic fibres, as claimed in claim 22, in which:—ZrO2≤7 mol %. 24. Inorganic fibres, as claimed in claim 23, in which:—ZrO2≤5 mol %. 25. Inorganic fibres, as claimed in claim 1, that are melt formed and have been annealed at a temperature between 200° C. below a devitrification temperature for the fibres and the devitrification temperature for the fibres. 26. Inorganic fibres, as claimed in claim 25, in which the fibres have been annealed at a temperature and time sufficient to show an improvement in compressive strength at 900° C. of over 50% above unannealed fibres. 27. Inorganic fibres, as claimed in claim 26, in which the fibres have been annealed at a temperature and time sufficient to show an improvement in compressive strength at 900° C. of over 100% above unannealed fibres. 28. Thermal insulation comprising inorganic fibres as claimed in claim 1. 29. Thermal insulation, as claimed in claim 28, in which the insulation is in the form of a blanket of needled or otherwise entangled fibres. 30. Mastics comprising inorganic fibres as claimed in claim 1. 31. Composite materials comprising inorganic fibres as claimed in claim 1. 32. Papers comprising inorganic fibres as claimed in claim 1. 33. Support structures for catalyst bodies, the structures comprising inorganic fibres as claimed in claim 1. 34. Friction materials comprising inorganic fibres as claimed in claim 1. 35. Catalyst bodies comprising inorganic fibres as claimed in claim 1. 36. Fibre blends comprising inorganic fibres as claimed in claim claim 1. 37. Fibre blends as claimed in claim 36, in which the other fibres are or include polycrystalline fibres. 38. Inorganic fibres having a composition in weight percent:— Al2O3 36±1.5 wt %K2O 25.5±1.5 wt %SiO2 31±1.5 wt %ZrO2 6.5±0.5 wt %MgO 1±0.2 wt % with the total of these components being 99%-100% by weight. 39. Inorganic fibres formed as a glass having a composition comprising:— 10≤Al2O3≤50 mol %;12≤K2O≤40 mol %;30≤SiO2≤70 mol %; an amount of a nucleation promoting component effective to promote bulk crystallisation in the glass; the fibres bearing on at least part of their surface one or more potassium scavenging materials. 40. Inorganic fibres, as claimed in claim 39 in which the potassium scavenging materials comprise one or more sources of silica. 41. Inorganic fibres, as claimed in claim 40, in which the one or more sources of silica comprise a colloidal silica. 42. Inorganic fibres formed as a glass having a composition comprising:— 25≤Al2O3≤31 mol %;20≤K2O≤24 mol %;40≤SiO2≤45 mol %;3.5 mol %≤ZrO2≤7 mol %;1≤MgO ≤3 mol % in which SiO2+Al2O3+K2O≥80 mol % and with the total constituents not exceeding 100 mol %.