Powder formed from mineral or rock material with controlled particle size distribution for thermal films
View Patent ↗An ultra-fine powder formed from a naturally occurring mineral or rock material and having a controlled or “engineered” particle size distribution (PSD) to match the infrared spectra with a maximum particle size in the range of 14-17 microns measured as either D99, or preferably D95, and a minimum particle size D5 in the range of 4-7 microns. Preferably the maximum particle size is about 15 microns, the minimum particle size is about 5 microns and the D50 particle size is about 8-10 microns with the moisture content of the particle size “engineered” powder being less than about 0.20 percent by weight and preferably about 0.05 to 0.08 percent by weight of the powder. This specially “engineered” ultra-fine powder is used to reduce the thermicity of thermal film to a value less than about 20%.
1. A powder filler for thermal film, said powder filler having substantially no free silica and being formed from a naturally occurring mined substance with the particle size controlled where said powder filler is ultra-fine and has a particle size spread between D5 and D95 of less than about 12 microns and wherein said D95 particle size is 14-17 microns, said substance has a refractive index in the range of 1.4 to 1.6.
2. A powder filler for thermal film, said powder filler having substantially no free silica and being formed from a naturally occurring mined substance with the particle size controlled where said powder filler is ultra-fine and has a particle size spread between D5 and D95 of less than about 12 microns and wherein said D5 particle size is in the range of 4-7 microns, said substance has a refractive index in the range of 1.4 to 1.6.
3. An ultra-fine powder filler as defined in claim 2 wherein said substance has a Mohs hardness of at least 5.
4. An ultra-fine powder filler as defined in claim 3 wherein said filler has substantially no free silica.
5. A powder filler for thermal film, said powder filler having substantially no free silica and being formed from a naturally occurring mined substance with the particle size controlled where said powder filler is ultra-fine and has a particle size spread between D5 and D95 of less than about 12 microns and wherein said D5 particle size is in the range of 4-7 microns, wherein said substance is nepheline syenite.
6. A powder filler for thermal film, said powder filler having substantially no free silica and being formed from a naturally occurring mined substance with the particle size controlled where said powder filler is ultra-fine and has a particle size spread between D5 and D95 of less than about 12 microns and wherein said D95 particle size is 14-17 microns, wherein said substance is nepheline syenite.
7. An ultra-fine powder filler for thermal film, said powder filler formed from a naturally occurring mined substance with an engineered maximum grain size in the range of 14-17 microns, a minimum grain size D5 in the range of 4-7 microns, a maximum node of the PSD curve for the powder being between 7 and 14 microns, said substance has a refractive index in the range of 1.4 to 1.6.
8. An ultra-fine powder filler as defined in claim 7 wherein the moisture content of said powder filler is less than 0.20%.
9. An ultra-fine powder filler as defined in claim 7 wherein said substance has a Mohs hardness of at least 5.
10. An ultra-fine powder filler as defined in claim 9 wherein said filler has substantially no free silica.
11. An ultra-fine powder filler as defined in claim 7 wherein said filler has substantially no free silica.
12. An ultra-fine powder filler for thermal film, said powder filler formed from a naturally occurring mined substance with an engineered maximum grain size in the range of 14-17 microns, a minimum grain size D5 in the range of 4-7 microns, a maximum node of the PSD curve for the powder being between 7 and 14 microns, wherein said substance is nepheline syenite.
13. An ultra-fine powder filler as defined in claim 12 wherein said maximum particle size is the D95 particle size.
14. An ultra-fine powder filler as defined in claim 13 wherein said maximum particle size is about 15 microns and said minimum particle size is at about 5 microns.
15. An ultra-fine powder filler as defined in claim 12 wherein said maximum particle size is about 15 microns and said minimum particle size is about 5 microns.
16. An ultra-fine powder filler as defined in claim 13 wherein said D50 particle size is in the range of 8-10 microns.
17. An ultra-fine powder filler as defined in claim 12 wherein said D50 particle size is in the range of 8-10 microns.
18. An ultra-fine powder filler as defined in claim 13 wherein the moisture content of said powder filler is less than 0.20%.
19. An ultra-fine powder filler as defined in claim 12 wherein the moisture content of said powder filler is less than 0.20%.
20. An ultra-fine powder filler as defined in claim 13 wherein said filler has substantially no free silica.
21. An ultra-fine powder filler as defined in claim 12 wherein said filler has substantially no free silica.
22. A thermal film comprising a filler formed from a naturally occurring mined substance with an engineered maximum particle size in the range of 14-17 microns, a minimum grain size D5 in the range of 4-7 microns and a maximum node of the PSD curve for the powder being between 7 and 14 microns, said maximum particle size being the D95 particle size, said mined substance having a refractive index of about 1.4 to 1.6.
23. A thermal film as defined in claim 22 wherein said filler is loaded at a percentage to give a thermicity of less than 20%.
24. A thermal film comprising a filler formed from a naturally occurring mined substance with an engineered maximum particle size in the range of 14-17 microns, a minimum grain size D5 in the range of 4-7 microns and a maximum node of the PSD curve for the powder being between 7 and 14 microns, said mined substance having a refractive index of about 1.4 to 1.6.
25. A thermal film as defined in claim 24 wherein said filler is loaded at a percentage to give a thermicity of less than 20%.