Method and compositions for laser imprinting and articles imprinted using such methods and composition

• US 5,919,853 A
• Filed: 07/16/1997
• Issued: 07/06/1999
• Est. Priority Date: 01/30/1996
• Status: Expired due to Fees

• Current Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Original Assignee: Otis Elevator Company (Otis Worldwide Corp.)
• Inventors: Budnik, Daniel J., Condit, David A.
• Primary Examiner(s): Cain, Edward J.
• Application Number:
  US08/895,313
• Time in Patent Office: 720 Days
• Field of Search: 524/413, 524/430, 524/431, 524/492, 524/493, 524/495, 524/496
• US Class Current: 524/413
• CPC Class Codes: B23K 26/18 using absorbing layers on the workpiece, e.g. for marking or protecting purposes
• CPC Class Codes: B41M 5/24 Ablative recording, e.g. by burning marks; Spark recording marking by high energetic means, e.g. by laser otherwise than burning or ablative removal B41M5/26; materials or methods for recording or reproduction by optical means G11B7/00
• CPC Class Codes: B44C 1/22 Removing surface-material, e.g. by engraving, by etching for multi-layer articles B44C3/005
• CPC Class Codes: B44C 1/228 by laser radiation
• CPC Class Codes: B44C 1/26 Inlaying with ornamental structures, e.g. niello work, tarsia work
• CPC Class Codes: Y10T 156/1064 Partial cutting [e.g., grooving or incising]

Abstract

A method of imprinting a workpiece includes lasing the workpiece to create a depression or other opening, depositing a laser-fusible polymer material into the depression, and then lasing the material so as to fuse the material into the depression. Preferably, the laser-fusible polymer material is fusible in the near infrared spectrum. An alternate method for imprinting using colored powder paints includes an additional step of heating the workpiece to ensure thermosetting of the colored powder paint. Laser fusible materials having particular physical characteristics and compositions may be used to facilitate the process.

Claims

1. A laser-fusible composition, comprising:

a minor component which includes polyester, carbon black and titanium dioxide; and

a major component which includes a styrene acrylic polymer, iron oxide, polyolefin and silica.

2. A composition as claimed in claim 1, wherein said minor component is in a range of approximately 5% to approximately 20% of said composition.

3. A composition is claimed in claim 1, wherein said composition is fusible in the near infrared spectrum.

4. A laser-fusible composition for imprinting workpieces, wherein the workpieces include a depression adapted to receive the composition for laser fusing the composition into the depression, the composition being a powder material having particle diameters less than a predetermined diameter, wherein the predetermined diameter is dependant upon the thermal exposure of the composition during laser fusing.

5. The laser-fusible composition as claimed in claim 4, wherein the particle diamters are less than or equal to 45 μ

m.

6. The laser-fusible composition as claimed in claim 4, wherein the particle diamters are less than or equal to 38 μ

m.

7. The laser-fusible composition as claimed in claim 4, further including an absorber material, wherein the absorber material enhances the energy absorption of the powder material during laser fusing.

8. The laser-fusible composition as claimed in claim 7, wherein the absorber material enhances the energy absorption of the powder material in the near infrared region.

9. A laser-fusible composition for imprinting workpieces, wherein the workpieces include a depression adapted to receive the composition for laser fusing the composition into the depression, the composition being a powder material including an absorber material, wherein the absorber material enhances the energy absorption of the powder material during laser fusing.

10. The laser-fusible composition as claimed in claim 9, wherein the absorber material enhances the energy absorption of the powder material in the near infrared region.

11. The laser-fusible composition as claimed in claim 10, wherein the absorber material includes copper phthalocyanine material.

12. The laser-fusible composition as claimed in claim 11, wherein the ratio of absorber material to powder material is 0.1% or less.

13. The laser-fusible composition as claimed in claim 10, wherein the absorber material includes diammonium salt material.

14. The laser-fusible composition as claimed in claim 11, wherein the ratio of absorber material to powder material is 1% or less.

15. The laser-fusible composition as claimed in claim 9, wherein the absorber material includes metal particles added to the powder material.

16. The laser-fusible composition as claimed in claim 15, wherein the absorber material includes submicron nickel powder.

17. The laser-fusible composition as claimed in claim 15, wherein the absorber material includes nickel-based superalloy powder.

18. The laser-fusible composition as claimed in claim 15, wherein the metal particles have a particle diameter of less than or equal to 45 μ

m.

19. The laser-fusible composition as claimed in claim 9, wherein the absorber material includes carbon particles added to the powder material.