ADDTIVES FOR BRAKE PAD Potassium hexatitanate
KUBOTA “TXAX”
Introduction
TXAX is plate shaped potassium hexatitanate, far from needle-like whisker. The mean size of TXAX is much larger than whisker. The shape and size are manufactured only by Kubota's original melting method.
| TXAX-A | TXAX-MA | Potassium Titanate | |
|---|---|---|---|
| Manufacturing process | Melting method | Melting method | Calcinations of Flux method |
| Shape | Plate like | Plate like | Needle like |
| SEM Image |  |
 |
 |
| Mean length | 150μm | 65μm | 10μm |
| Mean width or diameter | 30μm(width) | 13μm(width) | 0.4μm(dia.) |
| Mean aspect ratio | 5 | 5 | 25 |
* such as Dupon’s “Fybex” which had been discontinued, or Otsuka Chemical’s “TISMO”
Physical Characteristics of TXAX
| Category | Measuring method | unit | TXAX-MA | TXAX-A |
|---|---|---|---|---|
| Color | Visual observation | - | Light Yellow | Light Yellow |
| Chemical formula | X ray diffraction | - | K2Ti6O13(TiO2) | K2Ti6O13 |
| Shape | SEM observation | - | Plate like | Plate like |
| Size | SEM observation | um | Mean length: 65 Mean width: 13 | Mean length: 150 Mean width: 30 |
| PH | Quality standard of TXAX-A | - | 8 | 8 |
| Particle density | Le Chatelier pycnometer | g/㎤ | 3.6 | 3.5 |
| Bulk density | Bulk density measuring method | g/㎤ | 0.2 | 0.5 |
| Specific surface area | BET method | m²/g | 1.50 | 0.75 |
| Mohs hardness | Conversion from Vickers hardness | - | 3~4 | 3 |
| Melting point | DTA | ℃ | 1310~1350 | 1310~1350 |
| Moisture | 150℃~10min | mass% | 0.4 | 0.2 |
SEM: Scanning electron microscope
BET: Brinier, Emmett, Teller
DTA: Differential thermal analysis
Safety information of TXAX
- Registration in TSCA Inventory and EPA's first view on 1991 TSCA
No.(=PMN No.) P90-226 Potassium hexatitanate fiber, such as TXAX, is not found to have the same danger as asbestos, because the fibers manufactured by the melting method have larger width.
- EPA's final view on 1997, based on the results of sub-chronic inhalation toxicity studies
The study focused on the potentially most highly hazardous fraction,
because test animals were exposed to only TXAX's respirable fibers.
On that basis, EPA judged that TXAX does not have a significant risk of cancer or fibrosis.