The invention relates to a laser-markable polyamide composition comprising: a first phase comprising Sb.sub.2O.sub.3 and an aliphatic polyamide with an amide density AD1, and a second phase comprising an aliphatic polyamide with an amide density AD2, wherein AD1-AD2 is at least 0.01, and wherein the amount of Sb.sub.2O.sub.3 is between 0.1 and 5 wt %, a halogen-free flame retardant in an amount of between 1 to 25 wt %, wherein the amount in weight percentage are based on the total amount of composition. The invention also relates to a process for preparing a laser-markable polyamide composition, as well as laser-marked products comprising the composition.

A universal or all-purpose laser marking composition for forming satisfactorily dark laser marks on a wide variety of substrates is provided. The marking composition comprises an enhancer of nitrides, carbides, silicides, and combinations thereof. The enhancer may be selected one or more of ferromanganese, ferrosilicon, Fe.sub.xSi.sub.(1-x) where X can range from about 0.005 to 0.995, Fe.sub.5Si.sub.2, MgFeSi, SiC, CaSi, (Co)Mo, MoSi.sub.2, TiSi.sub.2, ZrSi.sub.2, WSi.sub.2, MnSi.sub.2, YSi, Cu.sub.5Si, Ni.sub.2Si, Fe.sub.3C, Fe.sub.7C.sub.3 and Fe.sub.2C, MoC, Mo.sub.2C, Mo.sub.3C.sub.2, YC.sub.2, WC, Al.sub.4C.sub.3, Mg.sub.2C, Mg.sub.2C.sub.3, CaC.sub.2, LaC.sub.2, Ta.sub.4C.sub.3, Fe.sub.2N, Fe.sub.3N, Fe.sub.4N, Fe.sub.7N.sub.3, Fe.sub.16N.sub.2, MoN, Mo.sub.2N, W.sub.2N, WN, WN.sub.2, and combinations thereof and combinations thereof. Upon disposing the marking composition on a substrate and exposing the marking composition to laser radiation, the marking composition absorbs the laser radiation, increases in temperature, chemically bonds with the substrate, and when formed on each of a metal, glass, ceramic, stone, and plastic substrates, the mark has a negative L dark contrast value of at least 1 compared to a mark formed by the marking composition without the enhancer.

A compounded polymer material that can be laser marked is provided. The compounded polymer material includes an enhancer of nitrides, carbides, silicides, or combinations thereof. Upon forming the compounded polymer material into an article and exposing it to laser radiation, the irradiated portion of the compounded polymer material absorbs the laser radiation, increases in temperature, and forms a mark in the article. A lightness value difference (L) between the mark and the non-irradiated portion of the article has an absolute value of at least 5, and the lightness value difference between the mark and the non-irradiated portion is greater than if the polymer material did not include the enhancer.

Disclosed is a method for manufacturing a multi-layer data medium by hot rolling under pressure, able to be marked under the effect of laser radiation applied to at least one outer surface (11) of this medium, in which at least one marking (13) with optically variable effect is disposed with respect to a laser marking sub-layer so that the outer surface (11) has a portion with optically variable effect optically superimposed on at least one part of the laser marking sub-layer and a portion (16) without marking with optically variable effect optically superimposed on at least one part of the laser marking sub-layer. These portions are produced with contents of at least one marking agent which is sensitive to the laser radiation which are different.

A laser marking additive including a bismuth compound and a polyol. The laser marking additive can be directly added to a matrix polymer to prepare a laser markable composition, or the laser marking additive can be added to a polymer to prepare a masterbatch, which can be added to a matrix polymer. Preferred polyols are PEG, and polyols having at least 3 hydroxy groups.

The present invention relates to colored laser-markable and laser-weldable polymeric materials which are distinguished by the fact that they comprise, as absorber, at least one doped tin oxide or indium oxide having a large specific surface area.

Flame retardant thermoplastic compositions that are capable of being used in a laser direct structuring process. The compositions include a thermoplastic resin, a laser direct structuring additive, and a flame retardant. The compositions offer flame retardant characteristics while also substantially maintaining the mechanical properties of the base thermoplastic resin, such as the impact strength and/or HDT of the composition. The compositions can be used in a variety of applications such as personal computers, notebook and portable computers, cell phone and other such communications equipment.

A tattoo arts practice pad is made by forming an otherwise-blank silicone pad having distributed pigment from a color dye, then lasering imagery onto the pad to result in traceable line images corresponding to areas that discolor the ink, so that discoloration in the shape of the line image on the pigment results without covering silicone with another material and without altering smoothness or silicone-tattoo needle interactions.

The invention relates to a process for partial colouring, in particular colour laser engraving, of plastic parts, preferably of thermoplastic parts, very particularly preferably of thermoplastic parts comprising a layer construction, comprising the steps of: i) providing a plastic part (A) having at least one surface; ii) laying a colour tape atop at least one portion of the at least one surface of the plastic part (A) to obtain a surface of the plastic part (A) covered with the colour tape; iii) irradiating the plastic part (A) from ii) with focused, preferably nonionizing, electromagnetic radiation (C) on at least one portion of the surface of the plastic part (A) covered with the colour tape, wherein the partial colouring is effected essentially only at the sites on the plastic part (A) irradiated in step iii), wherein the wavelength range of the focused, preferably nonionizing, electromagnetic radiation (C) is in a range from 200 to 20 000 nm, preferably in a range from 300 to 18 000 nm, particularly preferably in a range from 350 to 16 000 nm.

There is provided a medium issuance system which can easily transfer print on an intermediate transfer sheet to a polycarbonate transfer medium. The medium issuance system 50 includes an intermediate transfer sheet supply section 52 for supplying an intermediate transfer sheet 53 to a polycarbonate transfer medium 1, and a hot stamp 55 for heating and pressing the intermediate transfer sheet 53 to transfer print 10A, 10C on the intermediate transfer sheet 53 to the transfer medium 1. The hot stamp 55 heats and presses the intermediate transfer sheet 53 at a temperature of not less than 120? C. and not more than 200? C., and at a pressure of not less than 0.1 kgf/cm.sup.2 and not more than 1000 kgf/cm.sup.2.