Security thread and process for the preparation thereof

• US 20020058138A1
• Filed: 12/27/2001
• Published: 05/16/2002
• Est. Priority Date: 03/02/1998
• Status: Abandoned Application

• Current Assignee: Korea Security Printing & Minting Corp.
• Original Assignee: Korea Security Printing & Minting Corp.
• Inventors: Park, Yong-Hwan, Kim, Jong-Kyu
• Application Number:
  US10/033,494
• Publication Number:
  US 20020058138A1
• Time in Patent Office: Days
• US Class Current: 428/364
• CPC Class Codes: D21H 21/42 Ribbons or strips filaments D21H15/06
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber

Abstract

A partially metallized film having a dyed region and a transparent region alternately at an each regular interval on a major surface thereof is useful as a security thread to be embedded in a security paper. The partially metallized film for a security thread is conveniently prepared by printing a fluorescent pigment or dyestuff at a regular interval on a transparent film, applying a water-soluble ink over the dyed regions and to another selected portions of the film at a regular interval, depositing a layer of a metal on the entire surface of the transparent film including the water-soluble ink layer; and washing the metal deposited film with water to remove the portion of the metal layer deposited on the water-soluble ink layer.

Claims

1. A partially metallized film for a security thread having a dyed region and a transparent region alternately at an each regular interval on a major surface thereof, the regions being in the form of a figure, character or pattern.

2. The partially metallized film for a security thread according to claim 1, wherein the film is prepared by a process comprising the steps of

(i) printing a fluorescent pigment or dyestuff at a regular interval on a major surface of a transparent film in the form of a figure, character or pattern;

(ii) applying a water-soluble ink over the pigment or dyestuff-printed regions and to another selected portions of the major surface of the film at a regular interval in the form of a figure, character or pattern;

(iii) depositing a layer of a metal on the entire surface of the transparent film including the water-soluble ink layer; and

(iv) washing the metal deposited film with water to remove the portion of the metal layer deposited on the water-soluble ink layer.

3. The partially metallized film for a security thread according to claim 2, wherein the metal is selected from the group consisting of aluminum, tin, silver and an alloy of cobalt and nickel.

4. The partially metallized film for a security thread according to claim 1, wherein the film has a thickness ranging from 15 to 35 μ

m and a width ranging from 0.5 to 5 mm.