Laser marking of phosphorescent plastic articles
US5976411A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Dec 16, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24901
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention provides molded, extruded or formed phosphorescent plastic articles having laser marked indicia and methods for preparing the articles. The indicia may be seen as a contrast against a phosphorescent background or, alternatively, the indicia may themselves be phosphorescent. An article of the invention has a composition comprising about 50% to about 99% by weight of a thermoplastic or thermosetting resin, about 1% to about 50% by weight of a phosphorescent phosphor pigment and about 0.001% to about 1% by weight of a laser energy absorbing additive. Resin compositions which themselves are laser energy absorbing do not require the additive; however, the addition of small quantities of the laser energy additive enhances the quality and contrast of the laser mark. The composition may further comprise small quantities of one or more of a whitening pigment, a lubricating agent, or an inert filler without interfering with the phosphorescence of the article and/or the quality and contrast of the laser mark.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.