Composition for laser marking

• US 6,214,916 B1
• Filed: 04/29/1998
• Issued: 04/10/2001
• Est. Priority Date: 04/29/1998
• Status: Expired due to Fees

• Current Assignee: SABIC Global Technologies BV (Government of Saudi Arabia)
• Original Assignee: General Electric Company
• Inventors: Zalm, Cor van der, Mercx, Franciscus P. M., Verhoogt, Hendrik
• Primary Examiner(s): Niland, Patrick D.
• Application Number:
  US09/069,261
• Time in Patent Office: 1,077 Days
• Field of Search: 524/539, 524/401, 524/404, 524/405, 524/414, 524/432, 524/394, 523/137, 430/56, 430/127, 430/200, 430/495.1, 430/945
• US Class Current: 524/404
• CPC Class Codes: B41M 5/267 Marking of plastic artifacts, e.g. with laser
• CPC Class Codes: C08K 2003/2296 of zinc
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/24 Acids; Salts thereof C08K3/16 takes precedence
• CPC Class Codes: C08K 3/38 Boron-containing compounds
• CPC Class Codes: C08K 5/098 Metal salts of carboxylic acids
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: Y10S 430/146 Laser beam

Abstract

A resin composition having laser marking properties from a NdYAG radiation laser wherein said composition comprises a polyester thermoplastic resin, a sufficient amount of light pigment for forming a light background coloration, and an effective amount of marking agent wherein said polyester thermoplastic resin decomposes in laser struck areas to form dark colored markings in laser struck areas on the light background coloration wherein the marking agent is selected from the group consisting of boron phosphate, zinc oxide, zinc stannate, zinc hydroxy stannate, tin (II) oxalate and mixtures thereof.

Claims

1. A resin composition having laser marking properties from a NdYAG radiation laser wherein said composition comprises a polyester thermoplastic resin, a sufficient amount of light pigment for forming a light background coloration, and an effective amount of marking agent wherein said polyester thermoplastic resin decomposes in laser struck areas to form dark colored markings in laser struck areas on the light background coloration wherein said marking agent is present in an amount of from about 1 to about 5 percent by weight based on the weight of the total weight of the resin composition and selected from the group consisting of boron phosphate, zinc oxide, zinc stannate, zinc hydroxy stannate, tin (II) oxalate and mixtures thereof.

2. A resin composition having laser marking properties according to claim 1 wherein said marking agent is present in a amount from 1 to 3 percent by weight based on the total weight of the composition.

3. A resin composition having laser marking properties according to claim 1 wherein said marking agent consist essentially of boron phosphate.

4. A resin composition having laser marking properties according to claim 1 wherein said marking agent consist essentially of zinc oxide.

5. A resin composition having laser marking properties according to claim 1 wherein said marking agent consist essentially of zinc stannate.

6. A resin composition having laser marking properties according to claim 1 wherein said marking agent consist essentially of zinc hydroxy stannate.

7. A resin composition having laser marking properties according to claim 1 wherein said marking agent consist essentially of tin (II) oxalate.

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

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.

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

10. A resin composition having laser marking properties according to claim 9 wherein said glass fibers comprise from 5 to 40 weight percent based on the total weight of the resin composition.

11. A molded article having laser radiated marked surface portions, said article comprising a resin composition having laser marking properties which resin compositions comprises a polyester thermoplastic resin, a sufficient amount of light pigment for forming a light background coloration, and an effective amount of marking agent wherein said polyester thermoplastic resin decomposes in laser struck areas to form dark colored markings in laser struck areas on the light background coloration wherein said marking agent is present in an amount of from about 1 to about 5 percent by weight based on the total weight of the resin composition and is selected from the group consisting of boron phosphate, zinc oxide, zinc stannate, zinc hydroxy stannate, tin (II) oxalate and mixtures thereof.

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

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.

13. A resin composition of claim 11 having laser marking properties additionally including reinforcing glass fibers.

14. A polyester resin composition of claim 13 having laser marking properties wherein said fibrous glass comprises from 5 to 40 weight percent based on the total weight of the resin composition.