Controlled color laser marking of plastics
US5977514A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Jun 13, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24901
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for obtaining both light and dark laser marks on a colored plastic article by using a composition with (i) a thermoplastic resin that foams when heated, (ii) about 0.4% to 0.7% by weight of a mica based laser energy absorbing additive and (iii) a coloring agent with one or more colorants selected from the group of pigments, dyes, and mixtures of pigments and dyes. Using a laser at certain settings results in charring of the resin to produce dark laser marks. At other selected laser settings, the resin foams to produce a light mark on a colored background. By varying the laser energy settings, various degrees of both foaming and charring can be achieved on a single plastic article, having a single resin composition, resulting in a multicolored laser image produced by various shades of light and/or dark marks against the background color.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.