Color development writing compositions and writing instruments
US10711150B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 2018 |
| Grant date | Jul 14, 2020 |
| Priority date | — |
| Expiry date | Aug 4, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K2003/2241
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Writing compositions capable of undergoing a color development when brought into contact with a specific substrate including a color change-inducing compound are provided. Application of the writing compositions to surfaces other than the intended substrate will avoid color development and prevent staining of the unintended surfaces. The writing compositions include at least one particulate filler including a clay, at least one leuco dye, one or more waxes chosen from a group consisting of polyethylene wax, soy wax, paraffin wax, and beeswax, at least one thermoplastic binder material including a polyethylene, titanium dioxide, and optionally at least one additive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.