Water-soluble glass composition

1. A water-soluble glass composition in the form of a solid body comprising 10 to 75 mole % P 2 O 5,

over 20 to 50 mole % alkali metal oxide,

up to 40 mole % ZnO and,

up to 40 mole % Bi 2 O 3 , the mole ratio of zinc to bismuth in the composition is in the range from 1:25 to 25:1 and wherein the composition is at least partially soluble in water and releases zinc and bismuth during a dishwashing cycle in an amount enough to ensure glassware corrosion protection without soiling the glassware.

2. A composition according to claim 1 , wherein the composition comprises 25 to 40 mole %, of an alkali metal oxide.

3. A composition according to claim 2 , wherein the alkali metal oxide is one or more of: Li 2 O, Na 2 O, K 2 O.

4. A composition according claim 1 , wherein the composition comprises less than 10 mole %, of an alkaline earth oxide.

5. A composition according to claim 4 , wherein the alkaline earth oxide is calcium oxide (CaO).

6. A composition according to claim 1 , wherein the composition comprises a refining agent.

7. A composition according to claim 6 , wherein the refining agent comprises less than 10 mole % of the composition.

8. A composition according to claim 6 , wherein the refining agent is a sulphate/oxide or antimony, arsenic, cerium, manganese or an admixture thereof.

9. A composition according to claim 1 , wherein the composition comprises an oxide of an element from the group consisting of silicon, germanium, tin and lead.

10. A composition according to claim 9 , wherein the amount of the silicon, germanium, tin or lead oxide is less than 10 mole %.

11. A composition according to claim 1 , wherein the composition comprises an oxide of an element from the group consisting of gallium, aluminium and boron.

12. A composition according to claim 9 , wherein the amount of the gallium, aluminium or boron oxide is preferably from 0.1 to 10 mole %.

13. A composition comprising:

from 41 to 54 mole % of P 2 O 5 ,

from 20 to 30 mole % of alkali oxides,

up to 5 mole % of SO 3 , from 15 to 25 mole % of ZnO,

from 0.2 to 1.5 mole % Bi 2 O 3 ,

less than 3 mole % of alkaline-earth oxides, and,

from 0.3 to 3 mole % of oxides of elements selected from the group consisting of silicon, aluminium and boron, and wherein the composition is at least partially soluble in water and releases zinc and bismuth during a dishwashing cycle in an amount enough to ensure glassware corrosion protection without soiling the glassware.

14. A composition according to claim 1 , wherein the composition is in the form of a shaped body.

15. A composition according to claim 1 , wherein the composition is in a comminuted form.