Reivindicaciones

1. Biodegradable glass fibre characterised by a glass composition of 58 to 60 % by wt. of SiO<2> 15 to 20 % by wt. of Na<2> O 0 to 3 % by wt. of K<2> O 2 to 4.5 % by wt. of MgO 5 to 9 % by wt. of CaO 7 to 9 % by wt. of B<2> O<3> 1.1 to 2.5 % by wt. of Al<2> O<3> 0 to 0.5 % by wt. of SO<4>2- 0 to 1 % by wt. being the remainder based on the mass of the composition in each case. 2. Glass fibre according to claim 1 in which the sum total of the components MgO and CaO is ≥10.5 % by wt. based on the mass of the composition forming the fibre. 3. Glass containing 58 to 60 % by wt. of SiO<2> 15 to 20 % by wt. of Na<2> O 0 to 3 % by wt. of K<2> O 2 to 4.5 % by wt. of MgO 5 to 9 % by wt. of CaO 7 to 9 % by wt. of B<2> O<3> 1.1 to 2.5 % by wt. of Al<2> O<3> 0 to 0.5 % by wt. of SO<4>2- 0 to 1 % by wt. being the remainder based on the mass of the composition in each case. 4. Glass according to claim 3 in which in which the sum total of the components MgO and CaO is ≥10.5 % by wt. based on the mass of the glass composition. 5. Process for the production of a biodegradable glass fibre in which the glass composition is melted, shredded to form primary fibres and drawn to form secondary fibres characterised in that a glass composition of 58 to 60 % by wt. of SiO<2> 15 to 20 % by wt. of Na<2> O 0 to 3 % by wt. of K<2> O 2 to 4.5 % by wt. of MgO 5 to 9 % by wt. of CaO 7 to 9 % by wt. of B<2> O<3> 1.1 to 2.5 % by wt. of Al<2> O<3> 0 to 0.5 % by wt. of SO<4>2- 0 to 1 % by wt. being the remainder based on the mass of the composition in each case is shredded into fibres by a centrifugal process. 6. Process according to claim 5 characterised in that a molten glass composition is used whose sum total of the components MgO and CaO is ≥10.5 % by wt. based on the mass of the composition. 7. Process according to claim 5 or 6 characterised in that the molten glass composition is shredded into fibres by means of a rotating disc. 8. Use of the glass fibres according to claim 1 or 2 as insulating or damping material.