Issued Patents All Time
Showing 1–18 of 18 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 9683118 | Oil-based pigment ink composition and oil-based pigment ink writing tool | Masamitsu Takahashi, Ryotaro Kaba | 2017-06-20 |
| 8431632 | Crayon | Kotaro Sumitomo, Masamitsu Takahashi | 2013-04-30 |
| 8299143 | Crayon and process for producing the same | Kotaro Sumitomo, Masamitsu Takahashi | 2012-10-30 |
| 8242190 | Crayon and process for producing the same | Kotaro Sumitomo, Masamitsu Takahashi | 2012-08-14 |
| 7943684 | Process for production of black crayon | Kotaro Sumitomo, Masamitsu Takahashi | 2011-05-17 |
| 7485406 | Photostorage solid drawing medium | Masamitsu Takahashi, Kotaro Sumitomo | 2009-02-03 |
| 7396400 | Water base erasable ink composition for use in marking pens | Keiko Nakamura, Jiro Nakagawa | 2008-07-08 |
| 7384459 | Crayon | Hirokazu Matsuda | 2008-06-10 |
| 7297732 | Solid composition | Akiko Shirota | 2007-11-20 |
| 7291210 | Solid drawing material and method for producing the same | Keiko Nakamura, Kotaro Sumitomo | 2007-11-06 |
| 7208036 | Water-based pigment-containing ink composition for central core type marking pen | Naoshi Murata, Makoto Hirotani, Tomohiro Sawa | 2007-04-24 |
| 6730154 | Polychromic ink composition depending on viewing angle | Hiroshi Inoue, Satoshi Maruyama, Norihiro Hirano, Naoshi Murata, Shoko Matsumoto +1 more | 2004-05-04 |
| 6203910 | Crayon | Shinji Tsujio | 2001-03-20 |
| 6074465 | Fluorescent crayon | Shinji Tsujio | 2000-06-13 |
| 6039795 | Ink composition for oil marking pen | Masakazu Yokoi | 2000-03-21 |
| 4753759 | Microcapsule manufacture | Tomio Onoguchi | 1988-06-28 |
| 4620941 | Thermochromic compositions | Kimio Yoshikawa, Juzo Kuroda | 1986-11-04 |
| 4605441 | Ink composition for indicating progress and completion of vulcanization of rubber products | Yoshiaki Masuda, Masaji Yamamoto | 1986-08-12 |