Ink security introduction

The so-called anti-counterfeiting ink, that is, adding a special performance of anti-counterfeiting materials in the ink chain material, processed by a special process of special printing ink. The anti-counterfeit inks currently developed and applied in China can be divided into 10 categories and are separately elaborated. The specific implementation is mainly printed on the ticket, product trademark and package by ink printing. This type of anti-counterfeiting technology is characterized by simple implementation, low cost, good concealment, bright colors, easy inspection (even hand-warming color change), and strong reproducibility. It is the preferred anti-counterfeiting technology for banknotes, tickets and trademarks in various countries.

1. UV fluorescent ink

Under the irradiation of ultraviolet light (200-400nm), it can emit special light with visible light (400-800nm). According to different wavelengths of the excitation light source, it can be divided into short-wave ultraviolet excitation fluorescence anti-forgery printing ink (excitation wavelength 254nm) and long-wave ultraviolet laser fluorescence anti-counterfeit printing ink (excitation wavelength of 365nm). According to whether the color of the ink is divided into two kinds of colored fluorescent ink and colorless fluorescent ink. Among them, fluorescent materials commonly used are classified according to their composition. First, the organic fluorescent material is an unsaturated molecule with a large conjugate, most of which are excited by sunlight. It is used for decoration with obvious colors, and has poor fluorescence stability and is easily oxidized and decomposed. Second, an inorganic fluorescent material synthesized at a high temperature is used. Luminescent materials for fluorescent screens and fluorescent tubes have good resistance to radiation and high stability, but are difficult to disperse in oily media. It is difficult to synthesize and has poor water resistance; in other words, chemically synthesized rare earth organic complexes are used as fluorescent materials. Conventional organic rare earth fluorescent complexes have simple preparation, are easy to disperse, dissolve, and refine in oily media, are colorless under visible light, and have strong fluorescence effects under ultraviolet light excitation.

2. Daylight excitation color change security ink

In the sunlight, it can emit visible light (400 ~ 800nm) anti-counterfeiting printing ink. This ink is discolored on the surface due to the action of the sun, and it is also substantially discolored by ultraviolet rays. At present, several kinds of such inks that have been developed and applied on the Chinese market are under sunlight (also under UV light), that is, discoloration effects can occur, from colorless to violet, blue, yellow, etc., and can also be designed to be colored. Colorless change is a rookie and wonderful thing in security materials.

3. Thermal security ink (also known as thermochromic security ink)

Under the effect of heating, the ink can change color effect. According to the different temperature required for discoloration, can be divided into hand-temperature color anti-counterfeiting ink and high-temperature anti-counterfeiting ink. Hand-type color change security ink refers to the 34-36 °C temperature, can produce discoloration effect of the ink. According to the difference in color change, it can be divided into single color reversible, multi-color irreversible and multi-color irreversible thermal ink. Now China has developed five kinds of hand-temperature single color reversible ink, color change methods are: rose red becomes colorless, purple red becomes colorless, blue becomes colorless, green becomes colorless, orange red becomes colorless can also be designed for Colored into a variety of other colors; 叁 kinds of high temperature single color reversible security ink, color change methods: pink to blue, yellow red, red and black and so on. Thermochromic substances can be classified into inorganic salts, coordination compounds, organic substances (dye molecules) and liquid crystal polymers.

4. Reaction color change ink

Various chemical substances added to the ink, under certain conditions, can produce various chemical reactions, so that the ink changes color, to achieve anti-counterfeiting purposes. Part of the heat-sensitive anti-counterfeit inks, pressure-sensitive color-changing inks, and humidity-sensitive color changes are all color-changing inks. In addition, the acid tellurium indicator is added to the ink, and after the trademark is printed, a color change agent is encountered, which can change the color of the ink and achieve the purpose of anti-counterfeiting.

5. Magnetic ink

It is a special ink made by mixing magnetic iron oxide powder into ink. At this stage, it is mainly used to print magnetically encoded letters and symbols of bank tickets, and has the effect of recording and storing information. A magnetically encoded ticket can be inserted into a magnetic code reader to identify authenticity. Appropriately used on the packaging and decoration, it can have a stronger and more secure anti-counterfeit.

6. Biochemical reaction ink

This type of ink is mixed with a substance that produces a biochemical reaction. This ink can be used first to apply a marker that is not visible to the naked eye to the packaged goods and to the anti-counterfeiting prints. Then, the chemical reagents are selected according to the formula and used. When operating with slight heat, moisture, or friction, words or patterns will appear. As the chemical composition of the ink is relatively complicated, it is very difficult to make counterfeit, some secret documents, important tickets, etc. are printed using this ink.

7. LCD ink

Compounds with crystalline properties were added to the liquid crystal ink. Under the influence of weak current and temperature, the liquid crystal displays bright and dark patterns and colors due to changes in the crystal lattice. With this kind of ink, the packaging and decorating products can react with changes in temperature. If it is used to print calendars, it will show different colors as the temperature of the four seasons changes. It is a kind of new ink material that is very vital and yet to be developed. The promotion of its use in the field of packaging and decoration, its anti-counterfeiting effect is incalculable.

8. Printing ink

Printing ink is made up of pigments, fillers, binders, etc. The choice of ingredients in pigments is an important factor in determining the hue and vividness of prints. Ink toning is a very complex problem. Some organic and inorganic pigments in nature have differences in chroma, brightness, and some intrinsic colors that cannot be achieved by artificial synthesis. The ink of the same type produced by different ink factories varies in color from batch to batch. Therefore, some of the larger manufacturers of packaging and decorating products use their own products to print at some large-scale and more technologically advanced printing companies. At the same time, they have customized special inks for each product in the ink factory. The ink factory is responsible for confidentiality.

9. Laser holographic logo combined with fluorescent encryption security ink

Laser holograms have been widely used in trademarks, corporate logos and other fields. However, with the popularization, application and popularization of laser hologram preparation technology, there are many manufacturers that can produce laser holograms. If it can not damage the integrity of the laser holographic identity on the premise of adding new anti-counterfeiting measures for secondary encryption, it can improve its anti-counterfeiting capabilities.

Our country has now researched and developed a laser holographic logo secondary encryption comprehensive anti-counterfeiting technology, that is, on the laser holographic logo, after adding certain detectable special fluorescent materials through a certain process, it is invisible to the naked eye in the sunlight, and the ultraviolet light of the money detector is The following shows special colored fluorescent graphics, featuring abrasion resistance, heat resistance, convenient and accurate detection, and strong anti-counterfeit features, with less increase in production costs.

10. In addition to altered ink

If a correction is made at the corresponding site, some kind of password will appear. This type of ink is mainly used to print securities such as cheques, bills of exchange and documents. If someone alters or eliminates the original figures on the denominations of bills of exchange, it will immediately appear as "Voided."

Reprinted from: China Security Network