Marked thermoplastic compositions, methods of making and articles comprising the same, and uses thereof
View Patent ↗An article for laser marking can comprising: a thermoplastic composition comprising a thermoplastic polymer, an active component comprising at least one of a polymeric unit and an additive, wherein the thermoplastic polymer has a visible transmission of greater than or equal to 80% according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer, and thickness of 1 mm; and a mark produced by chemical rearrangement of the active component generated by a laser of a first wavelength; wherein the mark exhibits at least one of: (i) a change in optical properties in the region 400 nm to 700 nm when exposed to light having a wavelength less than or equal to 500 nm; and (ii) a change in optical properties in the region of 400 nm to 700 nm when exposed to light having a wavelength greater than or equal to the first wavelength.
1. An article for laser marking comprising:
a thermoplastic composition comprising a thermoplastic polymer, a component comprising at least one of a polymeric unit and an additive, wherein the thermoplastic polymer has a visible transmission of greater than or equal to 80% according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer, and thickness of 1 mm; and
a mark produced by chemical rearrangement of the component generated by a laser of a first wavelength;
wherein the mark exhibits a change in optical properties in the region of 400 nm to 700 nm when exposed to light having a wavelength greater than or equal to the first wavelength as compared to an area of the article without the mark; and
wherein the change in optical properties comprises a change in reflection.
2. The article of claim 1 , wherein the mark exhibits a change in reflection in the region 400 nm to 700 nm when exposed to light having a wavelength greater than or equal to 400 nm and a change in optical properties in the region 400 nm to 700 nm when exposed to light having a wavelength less than or equal to 500 nm.
3. The article of claim 1 , wherein the mark is visible when exposed to light having a wavelength of less than or equal to 400 nm.
4. The article of claim 3 , wherein the mark is only visible when exposed to light having a wavelength of less than or equal to 400 nm.
5. The article of claim 1 , wherein the thermoplastic composition comprises another additive comprising at least one of ultraviolet absorbing additive selected from hydroxybenzophenones, hydroxybenzotriazoles, hydroxybenzotriazines, cyanoacrylates, oxanilides, benzoxazinones, benzylidene malonates, hindered amine light stabilizers, nano-scale inorganics, and combinations comprising at least one of the foregoing.
6. The article of claim 1 , wherein the component is capable of being activated by the laser and wherein the component comprises ester groups of the formula
wherein at least 60 percent of the total number of R 1 groups contain aromatic moieties and the balance thereof are aliphatic, alicyclic, or aromatic, and R 2 groups can be oxygen, aliphatic, alicyclic, or aromatic, or contain aromatic moieties with the balance thereof being aliphatic, alicyclic, or aromatic.
7. The article of claim 6 , wherein the component is a carbonate group, R 2 is oxygen derived.
8. The article of claim 1 , wherein the thermoplastic polymer has less than or equal to 50% carbonate groups.
9. The article of claim 1 , wherein the thermoplastic polymer comprises polycarbonate, polyesters, polymethyl methacrylate, polystyrene, polybutylene terephthalate, polyolefins, polyamides, polyvinylchloride, polylactic acid, and combinations comprising at least one of the foregoing.
10. The article of claim 1 , wherein the first wavelength is less than or equal to 500 nm.
11. The article of claim 1 , wherein the first wavelength is less than or equal to 400 nm.
12. The article of claim 1 , wherein the component is capable of photo-chemical rearrangement into an ortho hydroxy-aryl carbonyl derivate.
13. The article of claim 1 , wherein the component is capable of laser induced deprotection to generate a UV active fluorophore.
14. An article for laser marking comprising:
a thermoplastic composition comprising a thermoplastic polymer, a component comprising at least one of a polymeric unit and an additive, wherein the thermoplastic polymer has a visible transmission of greater than or equal to 80 % according to ASTM D1003 -00, Procedure A, using D65 illumination, 10 degrees observer, and thickness of 1 mm; and
a mark produced by chemical rearrangement of the component generated by a laser of a first wavelength;
wherein the mark exhibits a change in optical properties in the region 400 nm to 700 nm when exposed to light having a wavelength less than or equal to 500 nm as compared to an area of the article without the mark; and
wherein the change in optical properties comprises a change in reflection.