Material composition and method for its manufacture
A material composition for play or modelling purposes includes a particulate material and a binder which is disposed as thin layers on the particles. T-he binder includes a hydroxy-terminated polymer cross-linked by a boron compound, in particular a silicone oil. The concentration of particles is 90-98 vol % of the finished composition. A method for producing the material composition includes placing the particles in a mixer, adding the hydroxyl-terminated polymer, in particular silicone oil, and distributing it as thin layers on the surfaces of the particles and, thereafter, adding a boron-containing cross-linking agent in solution and mixing so that a cross-linking of the polymer takes place and the viscosity increases.
1. A material-composition, comprising on the one hand a particulate or granular material and, on the other hand, a binder which is disposed as a coating on the particles or grains, the binder comprising a hydroxyl-terminated polymer cross-linked by a boron compound, wherein the concentration of the particulate or granular material is about 90-98 vol % of the finished composition.
2. The material composition as claimed in claim 1 , wherein the hydroxy-terminated polymer is a silicone oil.
3. The material composition as claimed in claim 1 , wherein the particles or grains are coated with a surface-modifying agent under the coating of the binder.
4. The material composition as claimed in claim 3 , wherein the surface-modifying agent realises a layer of solid silicone.
5. The material composition as claimed in claim 1 , wherein the mean particle size of the particulate or granular material is about 0.05-0.5 mm.
6. The material composition as claimed in claim 5 , wherein the mean particle size of the particulate or granular material is about 0.07-0.15 mm.
7. A method for the production of a material composition, comprising the steps:
placing a quantity of particles or grains in a mixer;
supplying at least a first ingredient included in a binder of the material composition, the first ingredient comprising a hydroxy-terminated polymer of low viscosity, to the mixer;
distributing the first ingredient included in the binder as layers on surfaces of the particles or grains;
thereafter supplying a second ingredient in the form of a boron-containing cross-linking agent to the mixer in dissolved form for cross-linking the layers of the first ingredient.
8. The method as claimed in claim 7 , comprising raising the temperature of the composition.
9. The method as claimed in claim 7 , comprising surface modifying the particles to improve their adhesion to the binder.
10. The method as claimed in claim 7 , comprising kneading and de-airing after the second ingredient has been supplied.
11. The method as claimed in claim 7 , wherein the first ingredient is a hydroxy-terminated silicone oil.
12. The material composition as claimed in claim 2 , wherein the particles or grains are coated with a surface-modifying agent under the coating of the binder.
13. The material composition as claimed in claim 3 , wherein the surface-modifying agent realises a layer of solid silicone.
14. The material composition as claimed in claim 2 , wherein the mean particle size of the particulate or granular material is about 0.05-0.5 mm.
15. The material composition as claimed in claim 14 , wherein the mean particle size of the particulate or granular material is about 0.07-0.15 mm.
16. The method as claimed in claim 8 , comprising surface modifying the particles to improve their adhesion to the binder.
17. The method as claimed in claim 8 , comprising kneading and de-airing after the second ingredient has been supplied.
18. The method as claimed in claim 8 , wherein the first ingredient is a hydroxy-terminated silicone oil.