WO2012063117A1

WO2012063117A1 - Process for carrying-out anti-counterfeiting labels provided with invisible identifying signs

Info

Publication number: WO2012063117A1
Application number: PCT/IB2011/002641
Authority: WO
Inventors: Riccardo D'agostino; Pietro Favia; Francesco Fracassi; Pasqua Rossini; Lorenzo Barca; Paolo Benigno
Original assignee: Plasma Solution S.R.L.
Priority date: 2010-11-10
Filing date: 2011-11-10
Publication date: 2012-05-18
Also published as: IT1402447B1; ITBA20100046A1

Abstract

The present invention deals with a process for the realization of labels endowed with an invisible identification drawing to use as an effective method for preventing counterfeiting. This is based on treatments able to give different surface properties to different domains of polymeric materials, paper materials and materials of other kind (e.g. hydrophilic areas alternating with other hydrophobic areas, areas with charge alternating with neutral areas, acid areas alternating with basic areas, etc) according to pre-set drawings, by means of an appropriate system of masks. The drawing obtained with our method will be totally invisible to the naked eye, but a commercial highlighter runned over the labels will allow to highlight a secret drawing applied to the batch identified by the said labels.

Description

PROCESS FOR CARRYING-OUT ANTI-COUNTERFEIT1NG LABELS PROVIDED WITH INVISIBLE IDENTIFYING SIGNS"

Technical field

The present invention deals with the realization of labels endowed with an invisible identification drawing to use as an effective method for preventing counterfeiting.

Invention background

The problem of counterfeiting involves a greater and greater number of industrial fields, from pharmaceutical products to food industry, from tobacco smoking products to credit cards. Such illegal activity is exponentially growing all over the world.

The forged goods, manufactured inside clandestine factories, with any quality control and/or conformity with national laws, pose a total risk to consumers and a serious threat to the enterprises that focus on the quality and the originality of the products.

The system of invisible writing, pertaining the present patent, allows to solve definitively this problem. The idea at the basis of the patent is based on the possibility to invisibly mark the products; by this way a sequence of numbers, symbols, logos, or letters are transferred in an exclusive way to the items to protect, thus guaranteeing their authenticity and protecting the interests of either the manufacturer and consumers.

The conducted study allowed to realize sticky and non-sticky labels customizable in an invisible way. With the surface modification technologies based on cold plasma processes (ablation processes, thin film deposition, and treatment), already successfully used in many industrial applications, it is possible to stamp confidential codes on labels which can be applied as a unique method of recognition for products to be protected.

The subject of EP 1855127 also deals with safety elements in safety optical devices for protecting from counterfeiting. In particular it describes safety _ elements in shape of labels with elements having a surface area with reliefs and microstructures leading to optical effects and methods for realizing these labels.

Nowadays cold plasma technology is numbered among the most versatile technologies used for properly modifying the surface properties of common materials, thus imparting them unusual performance considered impossible to reach by means of traditional technologies.

Plasma is a state of the matter in which there is a partially ionized gas rich of active species - atoms, radicals, ions, electrons - produced by the fragmentation and ionization of the neutral species contained in the gas feed. The state of the plasma can be found also in nature at high temperatures (thermal plasma) as in stars, lightning, fire, or at low temperature (cold plasma) as in aurora borealis and in interstellar space. In appropriate experimental conditions it is possible to artificially light on a cold plasma, at room temperature (neon lights, plasma TV sets, etc.).

By varying the process parameters (gas/vapors feed, pressure, power, etc.) in customized plasmochemical reactors, it is possible to expose the materials to the active species of the cold plasma, modifying their surfaces with three different categories of processes:

• etching (ablation) of the material with the formation of volatile compounds;

• deposition of thin films (PE-CVD, Plasma Enhanced Chemical Vapor Deposition);

• treatment of substrate - insertion, grafting of chemical functionalities on the surface.

By means of plasma technology it is possible to synthesize new surfaces on conventional thermolabile materials, such as polymers, paper, leather, textiles, without producing any degradation of the materials themselves, thus obtaining different and more interesting chemical composition and properties compared to the starting materials. In addition, the plasmochemical processes are dry processes working without solvents, by using very small amount of the active compounds in the gas feed, thus working in an eco- compatible way . Other important advantages of this technology are the reduced process cost, the possibility to scale up the processes for large products and the speed of the processes.

Summary

The present invention allows to realize labels and various materials customizable in an invisible way which can be utilized as anti-forging elements. These results are obtained with processes of surface modification by cold plasma, either at low or high pressure, able to modify the surface composition and the surface properties of the exposed materials by means of appropriate and customizable masks, with an invisible result that does not change the aesthetical appearance of the labels and of the materials.

Brief Description of the Drawings

Further features and advantages of the present invention can be obtained by looking at the following description, by way of an example and not a restriction, with reference to the attached drawings:

Figure 1 - Treated and untreated adhesive labels modified by means of the described invention, before and after coloring the labels by an highlighter. Figure 2 - Simplified scheme of a plasmochemical reactor suitable for the treatments described in this invention: A) winding/unwinding chambers for substrates - paper, polymers, metals; B) process chamber; C) winding/unwinding drums; D) substrate; E) electrodes

Detailed description of some preferred modes of realization for the present invention

The result of the chemical combination of two surfaces with different properties (e.g. surface energy, wettability, acid-base property, surface charging, etc.) results in a tangible outcome e.g. when a commercial highlighter is run over surface, in a way that is discovered a secret code applied to the batch - as shown in figure 1.

The plasma is generated by properly applying an electric field at high frequency (KHz- Hz) to the electrodes of the reactor, where the samples to be modified have been positioned. The gas feeding the plasma can eventually be delivered to the reactor in mixture with inert gas (buffer) by setting a proper flow and a proper pressure, in order to improve the homogeneity of the process. The process can be carried out at low pressure and at atmospheric pressure.

For the present invention a plasma reactor with parallel plate electrodes has been used, schematically reported in Figure 2.

This kind of reactor can be used for many applications, for examples it can be used for plasma treating fabrics. The chambers are connected to a pressure measuring system - controlled before, during and after the process - as well as to a pumping system for maintaining the pressure at an optimized value, and minimizing the contaminations before, during and after the process. In a typical process the whole system is evacuated until the base pressure reaches the value of few millitorr before introducing the process gas.

The feed gas mixture is introduced in the reactor through proper diffusers positioned on the walls of and/or on the electrodes; composition, flow and pressure of the gas feed are controlled by valves and mass flow controllers, in order to guarantee a homogeneous and constant inflow of active species on the substrate during the process.

The winding speed and the tension of the substrate on the winding/unwinding drums C can be opportunely adapted to the typologies of substrate (paper, polymers, metals). The motors for controlling the motion can be driven by inverter or "stepper" motors for a fine regulation, concurring to reduce the mechanical tensions of the substrate. The mask with the drawing to be transferred to the substrate is opportunely fixed, so that the substrate can run between the mask and the lower electrode.

During the process the substrate unwinds from the first drum, runs between the mask and the lower electrode, and stops. Then the plasma is turned on for an opportune time, so that it is possible to transfer the drawing of the mask to the substrate. After that the plasma is turned off, and the substrate is winded on the second drum, until a new substrate is transferred to the electrode. The plasma is therefore turned on again, and so on, until the entire substrate-web is treated.

In the reactor it is also possible to treat flat substrates with proper dimensions, which are in reels, by simply positioning them on the lower electrode, and setting over them a mask provided with the drawing to transfer.

The plasma is triggered between the electrodes E, which are positioned at an optimized mutual distance and a distance from the substrate, as a function of all process parameters (pressure, flux and composition of the gas, frequency and power of the applied electric field, etc). The distance between the electrodes can be varied from some centimeters to few millimeters. One or both the electrodes are properly connected to the high frequency electric field generator (KHz-MHz); one or both the electrodes can be covered with dielectric material. During the process the electric field can be triggered either at constant power or modulated according to an optimized periodicity. All the process can be automated, controlled by computer.

At the exit of the pumping system the gas originating from the process, that can contain volatile organic compounds deriving from the treatment of the substrate and/or of the gas feed, can be filtered on active carbon or other devices able to remove these organic compounds.

A typical process for transferring a drawing onto a web substrate in reel will proceed according the following modality:

- substrate loading

The substrate reel is loaded on the unwinding drum through an appropriate opening; the substrate iS ; unwinded and made to pass through process chamber, from there it passes in the winding chamber, and here is fixed to the winding reel. The mask is fastened well in contact with the substrate onto the lower electrode, so that the substrate can easily pass through it and the electrode. Then the reactor is closed and, automatically in dependence of system approval, it is evacuated by the pumps until the pressure value established before the process is reached.

- plasmochemical treatment

When the pressure required has been reached, the gas mixture is introduced in the reactor with the values of composition, flow and pressure predetermined for the process. Then the plasma is turned on between the electrodes at the optimized power and modulation for the required process time. After that the plasma is turned off, the web substrate is moved until a new untreated area is positioned. The plasma is therefore turned on again for treating the new exposed area, and so on.

- "venting" and removal of the treated web substrate

At the end of the process the plasma is turned off whilst the pumping system continue to evacuate the remaining gas/vapors of the process and of the substrate. The air is left to enters in the system (venting) for leading the chambers back to the atmospheric pressure, and removing the reel from the winding chamber.

The transfer of an invisible drawing on the labels can be carried out with the following experimental parameters:

Substrate: a sheet with labels of paper, polymer, fabric

Mask

substrate unwinding speed: 0 - 20 m/min

Base pressure: < 10 mtorr

Working pressure: between 10 and 2000 mtorr (low pressure); between 1000 torr and 5 atm (high pressure)

Gas feed: 02, Ar, HMDSO vapors, VTMS (vapors), CF4, C3F6, pure or in mixture.

Gas buffer (eventually to add to gas feed): N2, Ar, He, and other noble gases Frequency of the electric field: 10 KHz - 900 MHz (low pressure); ,1-150 KHz (high pressure)

Power of the electric field: 0.01 - 20 W/cm2 Total gas flow: 0.1-1000 sml/min (low pressure); 0.1-20 sl/min (high pressure)

Claims

1. Process of cold plasma treatments designed for invisibly marking a substrate, by transferring onto it a drawing, a code, a seal, a mark which are invisible by naked eye, with the aim of subsequently enabling easily its identification, thus verifying its authenticity

2. The process according to claim 1 in which the treated domains of the substrate have exactly the same reflectivity, color, roughness of the untreated ones.

3. The process according to claim 1 carried out in a plasmochemical reactor at a frequency higher than 100 MHz.

4. The process according to claim 1 performed with a cold plasma process at low pressure.

5. The process according to claim 1 obtained in a cold plasma process at atmospheric pressure.

6. The process according to claims 1 carried out in a plasmochemical reactor of "plasma-jet" type.

7. The process according to claims 1 , 4, 5, 6 performed on paper, polymer, fabric, metal substrates and labels.

8. The process according to claims 1 , 4, 5, 6 performed on paper, paperboard substrates and polymeric surfaces and labels used in food and pharmaceutical packaging.

9. The process according to claims 1 , 4, 5, 6 performed on paper, paperboard and polymeric surfaces and labels used in packaging of cigarette and cigars cartoons.

10. The process according to claims 1 , 4, 5, 6 performed on paper, paperboard, polymeric surfaces and labels used in for toy packaging.

11. The process according to claims 1, 4, 5, 6 performed on paper, paperboard, polymeric surfaces and labels suitable for packaging of jewels and luxury articles.

12. The process according claims 1 , 4, 5, 6 performed on paper, paperboard and polymeric surfaces and labels suitable for packaging of fashion articles.

13. Use in the process according claims 1 , 4, 5, 6 of a gas containing some of the following gases and vapors:

Gas buffer (Helium, Argon, Nitrogen) 0 - 95%

HMDSO or other monomers containing Si, C, O.H 0 - 95%

VTMS (Vapors) or other monomers containing Si,C, H 0 - 95%

14. The use in the process according to claims 1 , 4, 5, 6 of a gas containing some of the following gases or vapors:

Gas buffer (Helium, Argon, Nitrogen) 0 - 95%

Oxygen 0 - 100% Air 0 - 100% HMDSO (vapors) or other monomers containing Si, C, O,H 0 - 95% VTMS (Vapors) or other monomers containing Si.C, H 0 - 95%