Laser beam absorbing resin composition, coloring material therefor and laser bean marking method

• US 5,578,120 A
• Filed: 02/15/1996
• Issued: 11/26/1996
• Est. Priority Date: 04/22/1993
• Status: Expired due to Fees

• Current Assignee: Somar Pty Limited
• Original Assignee: Somar Pty Limited
• Inventors: Takahashi, Jun, Ochi, Hideo, Toyoda, Masaaki, Yasuda, Akira
• Primary Examiner(s): Szekely, Peter A.
• Application Number:
  US08/601,833
• Time in Patent Office: 285 Days
• Field of Search: 106/401, 106/446, 106/450, 106/467, 106/470, 106/482, 106/483, 252/501.1, 252/520
• US Class Current: 106/438
• CPC Class Codes: B41M 5/267 Marking of plastic artifacts, e.g. with laser
• CPC Class Codes: B41M 5/286 using compounds undergoing unimolecular fragmentation to obtain colour shift, e.g. bleachable dyes
• CPC Class Codes: B41M 5/46 characterised by the light-to-heat converting means; characterised by the heat or radiation filtering or absorbing means or layers
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01P 2004/32 Spheres
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C08K 3/34 Silicon-containing compounds
• CPC Class Codes: C09C 1/0081 Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound C09C1/0015, C09C1/0078 take precedence
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Abstract

A laser beam absorbing resin composition is disclosed which includes 100 parts by weight of a resin, and 1-100 parts by weight of composite particles having an average particle diameter of 0.1-50 μm and each including a particulate, laser beam absorbing inorganic substance, and a colorant physically bonded directly to the inorganic substance and capable of discoloring upon being heated at a temperature of 250° C. or more, the weight ratio of the colorant to the inorganic substance being in the range of 1:99 to 50:50. By irradiating a shaped, hardened body of the above composition with a laser beam, the colorant is thermally decomposed, so that the color of the irradiated surface is changed and becomes discriminative from that of non-irradiated surface.

Claims

1. A particulate coloring material comprising composite particles which have an average particle diameter of 0.1-50 μ

m and each of which is composed of (a) a particulate, laser beam absorbing inorganic substance selected from the group consisting of cordierite, zeolite, zirconium silicate and calcium silicate and (b) a colorant physically bonded directly to said inorganic substance and capable of discoloring upon being heated at a temperature of 250°

C. or more, the weight ratio of said colorant to said inorganic substance being in the range of 1;

99 to 50;

50.

2. A material according to claim 1, wherein said composite particles are obtained by a method including sintering a blend of said inorganic substance with said colorant to obtain a sintered mass, and pulverizing said sintered mass.

3. A material according to claim 2, wherein said colorant is Nb₂ O₅, TiO₂ (IV) and titanium yellow.