Heavy ion microporous security printing

Heavy ion micropore anti-counterfeiting is a new high-energy particle anti-counterfeiting high-tech emerging in recent years, also known as super anti-counterfeiting technology. It is currently one of the most important anti-counterfeiting technologies for high-energy particle-based anti-counterfeiting technology in China (the other is dual-core nuclear track technology). The research, promotion and application of this technology led it to go beyond the mysterious atomic energy laboratory and enter the field of mass life. It is an important result of the peaceful use of atomic energy technology.

1. Heavy ion micropore anti-counterfeiting principle

Heavy ion micropore anti-counterfeit has its unique advantages. It not only has superior anti-counterfeiting performance, but also its materials and technologies are controlled by the state, and counterfeiters cannot obtain it (it requires the use of high-energy particle control equipment to make plates), and its identification method is simple and suitable for the frontline. , second-line and third-line security.

We know that matter is made up of atoms. The atoms are composed of nuclei and electrons that run around the nucleus. The electrons in atoms are stripped and become ions. Heavy ions with certain energy can penetrate the plastic film and cause damage on the plastic film. Under traces, if these traces are chemically etched, micron-sized micropores with good consistency and diameters can be expanded. The diameter and density of these heavy ion micropores can be controlled. The use of thin membranes with heavy ion micropores for filtration is a good material. If a pattern is composed of a large number of heavy ion micropores on the thin film, under the visible light, due to the diffraction and refraction of the heavy ion micropores, the visual effect will be a white pattern when viewed by the human eye, and the non-pattern area will remain transparent. status. Heavy ion micropores can be air permeable and water-permeable. If a colored liquid (such as a pen) is applied, the pattern area will be colored, leaving a color pattern. To achieve anti-counterfeiting purposes.

2. Heavy ion micropore technology and its anti-counterfeiting features

Heavy ions with a certain amount of energy can penetrate plastic films. How can heavy ions be adequately functioned? Studies in nuclear physics tell us that heavy ion accelerators can accelerate the atomic nucleus with sufficient energy; fission fragments in nuclear reactors also have the energy to penetrate the thin film. This means that a security film with a heavy ion microhole pattern is to be produced, provided that a heavy ion accelerator or a nuclear reactor must be used. These nuclear facilities are all under the strict supervision of the relevant state departments. It is necessary to build and own these facilities, and only have funds. No approval from the competent national nuclear facilities department is not acceptable.

The traces left by the ion breakdown film can be at a fixed angle to the film surface. Studies have found that these traces can be used to form heavy ion micropores of various shapes in different ways, such as tapered, cylindrical, double-cone shaped through-holes or non-through holes. It is also possible to combine these differently shaped holes as needed. Different holes have different optical effects. The researchers used a variety of specific processes to develop visible and invisible heavy-ion micropore anti-counterfeiting labels.

Heavy ion micropore anti-counterfeiting technology uses transparent thin film as raw material, heavy ion radiation energy generated by heavy ion generator, irradiates plastic film, and breaks down the plastic film to form an air-permeable and water-proof anti-counterfeiting identification pattern composed of micropores. Divided into color-printing type, dripping water disappearance type, invisible micropore type and integrated type, microscopic observation of micropore pore size, hole density and hole type, compared with the special parameters to distinguish authenticity.

If the average consumer can identify with the simplest method and prove that the pattern is composed of heavy ion micropores, it will be possible to use this type of anti-counterfeiting label. Using a colored liquid, for example, smearing a pattern with a watercolor pen, peeling a heavy ion microporous security film from the substrate, leaving a print-through color pattern on the substrate proves that the pattern is composed of heavy ion micropores. . However, the security film is adhered to the substrate with an adhesive, and the adhesive can easily block the heavy ions and make the colored liquid unable to pass through. Therefore, the adhesive used must not only block the heavy ion micropores, but also make the coloring viscosity appropriate and not stick to the anti-counterfeiting film when uncovered. To achieve these requirements is not an easy task and must be solved with high technology. Now the heavy ion micro-hole anti-counterfeiting label realizes this requirement, and achieves both. At the same time, the parameters such as hole density and hole shape have opened up a place for multiple anti-counterfeiting and expert identification. The most important feature of the heavy ion micropore anti-counterfeiting technology is that the identification method is extremely easy, as long as the protective film on the label is peeled off, and then the colored paint is applied, so that the paint leaks into the microporous pattern, and then the excess paint is wiped To go, the security pattern is revealed, and the true and false are clear at a glance.

Heavy ion micropore anti-counterfeiting is a unique emerging anti-counterfeiting technology with extremely high anti-counterfeiting performance. Other anti-counterfeiting technologies, such as exquisite laser holographic anti-counterfeiting, color temperature change, anti-counterfeiting of light variable inks, anti-counterfeiting of various patterns, watermark paper anti-counterfeiting, and anti-counterfeiting of rainbow printing, also have their own characteristics, such as being able to combine them with heavy ion micro The combination of hole anti-counterfeiting technology is bound to be a major breakthrough in the field of anti-counterfeiting.

3. The application of heavy ion microporous technology in the field of security printing

After many years of research, Tsinghua University applied atomic energy science and technology, combined with other disciplines applied technology, research and development of the above heavy ion micropore anti-counterfeiting technology products - heavy ion micropore anti-counterfeiting labels. The novelty of this product is that its pattern of anti-counterfeit labels consists of a large number of heavy ion micropores with a uniform pore size. This kind of heavy ion micropore can not be imitated by mechanical and laser methods.

Heavy ion micropore anti-counterfeit labels are developed on the basis of two high-tech research results, one is nuclear heavy ion microporous membrane technology, and the other is heavy ion lithography. Its manufacturing method consists of three steps: First, the uranium fission fragments induced by accelerator heavy ions or reactor neutrons are used as "shells" to bombard plastic films, cause ionization damage on the surface and inside of plastic films, and form a nuclear track base film; The anti-counterfeit identification master pattern is copied into a transitional film plate and printed on the base film to form a lithographic mask; finally, through a chemical etching process, a pattern consisting of heavy ion micropores and the same as the original master plate is produced on the base film. Heavy ion microhole identification is manufactured using indirect radiation imaging methods, which is the development and application of heavy ion lithography in the field of anti-counterfeiting. Heavy ion microholes have pore densities of several million ions per cubic centimeter. The pore diameter is very small, in the micron or submicron range, is only about one-hundredth of the diameter of a hair and it is invisible to the naked eye. However, due to the light diffraction and refraction of heavy ion micropores, the anti-counterfeit pattern composed of a large number of micropore communities appears visually white, which is easily recognized by the naked eye and becomes the basis for mass identification of authenticity of commodities, while heavy ions are microporous. Microstructures and properties can be observed with an optical microscope.

The heavy ion micro-hole anti-counterfeiting mark has the characteristic of “microscopic microscopic display of macro display” and realizes the anti-counterfeiting target combining expert identification with mass identification. On the one hand, heavy ion micropores have very strict microscopic scientific parameters such as pore density, pore diameter, chance of heavy pores, and the like. These parameters are controlled by irradiation and etching processes, which can form a stringent cryptographic signal that is permanently stored within the knowledge and become the scientific basis for expert identification and legal identification. On the other hand, in the anti-counterfeit labels, a design scheme consisting of millions of heavy ion micropores for each logo pattern is adopted, so that invisible millions of pixels are “amplified” to become visible macroscopic patterns and reused. The optical and penetrating properties of heavy ion micropores make the pattern disappear or print. Without using any equipment, the eye can determine the authenticity; microscopic macro display is the true essence and vitality of heavy ion micropore anti-counterfeiting technology.

At present, heavy ion anti-counterfeiting technology is mainly applied to laser holographic films, various papers, plastic films and other materials, and can be used for various kinds of documents, documents, advanced product packaging, etc. It is a new generation of advanced technology and superior anti-counterfeiting performance. Anti-counterfeiting technology.