PAPER HAVING WATERMARK AND FORMATION OF WATERMARK
Document Type and Number:
Japanese Patent JP3486275
PROBLEM TO BE SOLVED: To easily form water marks by partially changing the thickness of the base material without mechanical pressing, for example, conventionally using a pressure roller.
SOLUTION: A near infrared ray-absorbing material 2 comprising a near infrared absorbing material which selectively absorbs the light of a prescribed wavelength in the near infrared area to emit heat and a binder is used to print desired characters or patterns for realizing water mark in a prescribed area 3 on the surface of the paper 1. Then, the paper 1 is radiated with the laser beam having a prescribed wavelength to burn the printed near infrared ray- absorbing material as well as a part of the base paper so that a prescribed thickness remains whereby the water mark is formed as the base paper is scraped off at a prescribed depth in the thickness direction.
October 24, 2003
September 30, 1995
TOPPAN MOORE CO LTD
B23K26/00; B23K26/18; B41M3/14; B41M7/00; D21H21/26; D21H25/04; D21H27/02; B23K26/00; B23K26/18; B41M3/14; B41M7/00; D21H21/14; D21H25/00; D21H27/02; (IPC1-7): D21H27/02; B23K26/00; B23K26/18; B41M3/14; B41M7/00; D21H25/04