Composition for laser marking

• US 6,127,475 A
• Filed: 09/25/1998
• Issued: 10/03/2000
• Est. Priority Date: 09/25/1998
• Status: Expired due to Term

• Current Assignee: SABIC Global Technologies BV (Government of Saudi Arabia)
• Original Assignee: General Electric Company
• Inventors: Vollenberg, Peter H. Th., Fisher, Robert A.
• Primary Examiner(s): Cain, Edward J.
• Application Number:
  US09/160,901
• Time in Patent Office: 739 Days
• Field of Search: 524/494, 524/495, 524/496
• US Class Current: 524/495
• CPC Class Codes: B41M 5/267 Marking of plastic artifacts, e.g. with laser
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence

Abstract

A resin composition with laser marking properties comprises a polyester thermoplastic resin, a sufficient amount of channel black carbon pigment for forming a dark background coloration wherein said channel black carbon pigment decomposes in laser struck areas whereby light colored markings are obtained on the dark background.

Claims

1. A resin composition having laser marking properties consisting essentially of a polyester thermoplastic resin, a sufficient amount of channel black carbon pigment for forming a dark background coloration whereby light colored markings are obtained on said dark background coloration in areas struck by laser light.

2. A resin composition having laser marking properties according to claim 1 wherein said channel black is present in a amount from about 0.01 to about 5 percent.

3. A resin composition having laser marking properties according to claim 2 herein said channel black is present in a amount from about 0.03 to about 3 percent.

4. A resin composition having laser marking properties according to claim 1 wherein said channel black has a fine non-aggomerated particles wherein a particle size from about 10 to about 30 nm.

5. A resin composition having laser marking properties according to claim 1 wherein said channel black is prepared by impinging combusted hydrocarbon gas on cooled surface.

6. A resin composition having laser marking properties according to claim 1 wherein said composition comprises a sufficient amount of light pigment for forming a light coloration in said laser struck areas.

7. A resin composition having laser marking properties according to claim 1 wherein said polyester composition comprises structural units of the following formula:

##STR2## wherein each R¹ is independently a divalent aliphatic, alicyclic or aromatic hydrocarbon or polyoxyalkylene radical, or mixtures thereof and each A¹ is independently a divalent aliphatic, alicyclic or aromatic radical, or mixtures thereof.

8. A resin composition having laser marking properties according to claim 1 additionally including reinforcing glass fibers.

9. A resin composition having laser marking properties according to claim 8 wherein said glass fibers comprise from 5 to 40 weight percent.

10. A molder article having laser radiated marked surface portions, said article comprises a polyester thermoplastic resin, a sufficient amount of channel black carbon pigment for forming a dark background coloration whereby light colored markings are obtained on said dark background in areas struck by laser light.

11. A resin composition having laser marking properties according to claim 10 wherein said polyester composition comprises structural units of the following formula:

##STR3## wherein each R¹ is independently a divalent aliphatic, alicyclic or aromatic hydrocarbon or polyoxyalkylene radical, or mixtures thereof and each A¹ is independently a divalent aliphatic, alicyclic or aromatic radical, or mixtures thereof.

12. A resin composition having laser marking properties according to claim 11 additionally including reinforcing glass fibers.

13. A resin composition having laser marking properties according to claim 12 wherein said fibrous glass comprises from 5 to 40 weight percent.