| 摘要 |
<p>The invention relates to a process for the manufacture of an object with a coloured marking by irradiating the surface of the object with laser light in the form of the marking, wherein at least at the place where the marking is applied the object consists of a plastic composition comprising at least three prechrome compounds which only acquire their colour-generating capacity after a colour-generating treatment and which under the influence of laser light can lose their colour-generating capacity again, the surface of the object being subjected to the colour-generating treatment at least at the place where the marking is applied, after which the surface of the object is irradiated with laser light in the shape of the marking, the prechrome compounds having been chosen such that and being present in such a concentration that with each wavelength between 400 and 700 nanometers at least part of the amount of incident light is absorbed.</p> |
