METHOD FOR TESTING THE RESISTANCE OF DATA CARRS AND SECURITY DOCUMENTS

Description

[0001] The present invention relates to a method for testing the resistance of data carriers such as ID, valuables, or identification documents and security documents. In particular, the invention relates to a testing method for the resistance of data carriers and security documents, such as ID cards, company ID cards, etc., personalized by printing and / or other security features, to disinfectants, particularly in medical environments.

[0002] For security documents, it is crucial that, despite intensive use, no or only minimal changes in appearance and functionality are noticeable throughout their entire service life. This applies especially to personalization.

[0003] Data carriers and security documents are often manufactured from different layers with security features and with personalisation incorporated by lamination, whereby the personalisation and security features can in principle be incorporated into the security document or data carrier and / or on its surface.

[0004] EP 1770385 A2 describes a method for testing the resistance of security documents and data carriers, whereby the surface of security documents or data carriers is rubbed with a rubbing pad that has previously been moistened with an artificial sweat solution as a test liquid.

[0005] DE 10 2015 208 802 A1 teaches a method for testing the resistance of materials used to manufacture valuable and security products to changes in their properties during use.

[0006] AU 2017 100 680 A4 teaches a method for determining the abrasion resistance of a functionalized substrate for production or use as a security document, wherein the abrasion simulation comprises a mechanical stress test, a chemical stress test at a temperature of at least 50 °C and a mechanical failure test.

[0007] Security documents, such as doctor's ID cards and health cards, are used in medical settings, where they may come into contact with disinfectants. These security documents are often personalized using thermal transfer or thermal sublimation printing, or they use a special inkjet ink that diffuses into the top layer. Contact with disinfectants can damage the document and compromise the legibility of the personalized design and / or the security feature.

[0008] US 8,329,777 B2 discloses a method for testing the resistance of security documents, in which the surface of the security document is scrubbed with isopropyl acetate or ethanol applied to cotton swabs.

[0009] Based on this, the object of the present invention is to provide a method with which the impairment of security documents or data carriers by disinfectants, in particular in a medical environment, can be tested in a simple manner and realistic conditions of the impairment can be simulated in a simple manner.

[0010] This problem is solved by the features of claim 1.

[0011] In the method according to the invention, the resistance of documents to disinfectants is determined by scrubbing the surface of security documents or data carriers with textile pieces that are previously wetted with a test liquid under defined conditions, wherein the scrubbing test is carried out with at least two different test liquids and the at least two different test liquids are selected from the groups of aqueous alcoholic solutions, liquids containing hydrophobic compounds and solutions containing biocides.

[0012] By conducting the tests with at least two different test liquids from the defined groups of test liquids, good results regarding the resistance of the security documents to disinfectants in the medical environment, for example in the context of hand disinfection, can be achieved in a small number of tests, without having to carry out the abrasion test on the surface of the security document with a large number of the different disinfectants available on the market.

[0013] Within the scope of the present invention, it was determined that realistic impairments can be simulated by conducting the abrasion test with a flat textile. It is understood that a new flat textile is used for each abrasion test with a test liquid.

[0014] The method according to the invention makes it possible to easily simulate the mechanical and chemical stresses caused by disinfectants in the medical environment and to test and ensure the long-term suitability of various surfaces of security documents or data carriers and the durability of personalization, security features, prints, applications, etc. against disinfectants in the medical environment.

[0015] According to the invention, the abrasion tests are carried out with at least two different test liquids from the three groups of test liquids explained below.

[0016] A test liquid is an aqueous alcoholic solution (hereinafter referred to as the first test liquid). The alcohol content in the solution should be a maximum of 96 wt.%, preferably between 50 wt.% and 95 wt.%, and particularly preferably between 60 wt.% and 90 wt.%.

[0017] In principle, all common alcohols, especially dialcohols and trialcohols, preferably with between 1 and 14 carbon atoms, can be used in the first test liquid. Particularly preferred alcohols are ethanol, n-propanol, propan-2-ol, n-, iso-, or tert-butanol, and butane-1,3-diol.

[0018] In addition, a mixture of different alcohols, such as ethanol / propan-2-ol, ethanol / butanol or ethanol / pentan-1-ol, ethanol / propan-1,2-diol, ethanol / butan-1,3-diol, ethanol / propan-1,2,3-triol, propan-1-ol / propan-2-ol can also be used in this first test liquid.

[0019] In a first preferred embodiment, the first test liquid is a concentrated aqueous ethanol solution; in a further preferred embodiment, the first test liquid is a concentrated aqueous isopropanol solution.

[0020] Within the scope of the invention, it is also possible to carry out the abrasion tests successively with both preferred variants of the first test liquid, thus with an ethanol solution and an isopropanol solution.

[0021] Another test liquid, hereinafter referred to as the "second test liquid," is a liquid containing hydrophobic compounds, wherein the hydrophobic compounds are preferably hydrocarbons, in particular alkanes, or a mixture of alkanes. The proportion of hydrophobic compounds, such as hydrocarbons, in particular alkanes, in the liquid is preferably between 2 wt.% and 30 wt.%, and particularly preferably between 3 wt.% and 10 wt.%. In principle, all liquid, preferably highly volatile, alkanes can be selected for the second test liquid, in particular alkanes with a carbon chain length of between 5 and 9 carbon atoms. Particular preference is given to using petroleum ether (petroleum ether gasoline) with a boiling range of 30°C - 70°C or 40°C - 65°C, or ligroin with a boiling range of 60°C to 100°C.

[0022] Generally, the hydrophobic component in this second test liquid is dissolved in a solvent such as an alcohol. The solvent content of the second test liquid is preferably in a concentration range between 70 wt.% and 98 wt.%, particularly preferably between 90 wt.% and 97 wt.%. The solvent is preferably an alcohol from the group consisting of ethanol, propan-1-ol, propan-2-ol, or a butanol or butanediol.

[0023] The third test fluid contains biocides, for example quaternary ammonium compounds such as trimethyltetradecylammonium bromide, benzalkonium chloride, cetylalkonium chloride, cetylpyridinium chloride, tetrabutylammonium hydroxide, paraquat polyquaternium-7 or tetradecyltrimethylammonium oxalate or biphenylol.

[0024] The biocide concentration is generally between 0.02 wt% and 5 wt%, preferably from 0.5 wt% to 4 wt% and particularly preferably from 1 wt% to 3 wt%.

[0025] The biocide(s) may be dissolved in a hydrophilic solvent or a hydrophilic solvent mixture, for example water or alcohol, in particular ethanol.

[0026] All test liquids are preferably solutions.

[0027] For the purposes of the present invention, a textile piece refers to raw materials processed into sheet-like structures such as woven, knitted, crocheted, braided, stitch-bonded, nonwoven, and felt of limited dimensions. The sheet-like textile is preferably made of cotton, particularly preferably a cotton fabric comparable to "Cotton Drill 702-480," which is used for the ISO 105-D01 standard.

[0028] By using the test fluids, a reliable statement can be made about the resistance of security documents to disinfectants. In addition, the results can be standardized based on the use of the defined test fluids and the defined test conditions, so that defined test conditions that can be reproduced over the long term are created.

[0029] This is not possible when using commercially available disinfectants, as the chemical composition often does not remain constant over many years.

[0030] The resistance of the security document is tested under defined conditions using at least two, preferably three or more, different test liquids from the groups of test liquids according to the invention. In the case of two test liquids, the test liquids are preferably selected so that they do not belong to the same group of test liquids.

[0031] If the test is carried out with three test liquids, at least two of the test liquids are preferably from different groups of test liquids.

[0032] If two or more test liquids are used in one variant, two different test liquids can also be selected from the group of aqueous alcoholic solutions.

[0033] In another variant, all three test fluids are selected from different groups.

[0034] If the abrasion test is carried out with four different test liquids, two test liquids should preferably be selected from the first group of aqueous alcoholic solutions and one test liquid each from the second and third groups.

[0035] For each test liquid, the individual test is then carried out using a piece of cloth, preferably a piece of cotton, moistened with the respective test liquid, whereby an abrasion test is carried out on the document surface with the moistened textile piece using a scouring or rubbing action that corresponds to the usage expectations.

[0036] In the context of the invention, "wetting" means that the textile piece is soaked in the test liquid or is sprayed or sprinkled with the test liquid.

[0037] It is essential that, within the scope of the present invention, the relevant number of different test liquids from the different groups can in principle be freely combined with one another, for example an 80% propan-2-ol / ethanol solution in water as the first test liquid, 10% octane in 90% butanol solution as the second test liquid and a solution of 4 wt.% tetrabutylammonium hydroxide in isopropanol as the third test liquid.

[0038] For the purposes of the invention, rubbing refers to a translational or rotational movement along the surface of the document under a certain pressure and over a specific area. A rubbing test is also referred to as an abrasion test.

[0039] The scouring can be carried out by a fixed number of double strokes under the influence of a defined scouring weight along a straight line, by a loading rotary movement or by a zigzag movement with defined angles to each other.

[0040] Scrubbing "under defined conditions" means that the test is repeated for the desired number of test solutions under the same conditions such as scrubbing pressure, scrubbing area, amount of wetted solvent, piece of textile, scrubbing path, number of double heights, etc.

[0041] This simulates the combination of mechanical abrasion and chemical stress in real-life use. In a preferred variant, in addition to the security document subjected to the abrasion test, the textile item is also examined after the abrasion test, for example, to determine whether and to what extent ink from the security document has rubbed off onto the textile item, or – in other words – whether and to what extent the document makes the disinfectant vulnerable, tamperable, and modifiable.

[0042] This procedure is generally suitable for all types of documents (including paper documents) and commercially available disinfectants for the medical environment.

[0043] If desired, the abrasion test can also be carried out with the desired disinfectant and / or the dry piece of textile.

[0044] In another variant, to test resistance to extreme stresses caused by disinfectants, the security documents are additionally completely immersed in the respective test fluid and then scrubbed under defined conditions with a dry textile or a textile moistened with the respective test fluid. The selected exposure time and scrubbing time must be set so that they at least correspond to the assumed extreme stresses. In a preferred variant of such an additional test for extreme stress, the exposure time was set at five minutes, more than twice the time specified for hand disinfection (0.5 minutes to 2 minutes) according to the Federal Health Gazette.

[0045] Depending on the material type, the dry textile fabric is often harder on the surface when unwetted. This makes the stress on the sample in the abrasion test even more intense.

[0046] The method according to the invention not only ensures the long-term suitability of the quality of the respective security documents, but also reduces the risk of complaints regarding the security documents.

[0047] The method is suitable for testing the resistance, in particular of plastic or paper surfaces of security documents and data carriers, especially polycarbonate, PVC or PET surfaces.

[0048] In addition, the durability of a personalization can be tested under defined conditions.

[0049] The process according to the invention can also be carried out with more viscous liquids, as long as they can wet the flat textile.

[0050] The abrasion tests can be evaluated, for example, through visual inspection, photo documentation, or UV / VIS spectroscopy, fluorescence spectroscopy, or laser scanning microscopy of the surface of the security document or data storage device. Furthermore, the functionality of any chips arranged on the surface or laminated chips with a correspondingly linked antenna can also be checked. Further evaluation of the deterioration of the surface of the security document or data storage device can be performed through examination with special light sources, ultrasound microscopy, and various electronic readout tests.

[0051] Furthermore, after conducting the abrasion tests, the flat textile pieces used can also be evaluated, for example, through spectroscopic analysis of the type and amount of dissolved dye, analysis of the dye itself, and detection of traces of metal or semiconductors that have been rubbed out. The amount of abrasion can be quantitatively analyzed using a digital image with pixel analysis using grayscale.

[0052] The area of ​​the piece of fabric used for scrubbing is generally between 45 and 55 cm2.

[0053] The contact pressure must be adapted to the conditions to be simulated and is preferably between 0.3 N / cm 2< and 0.7 N / cm 2< .

[0054] The abrasion under defined conditions is preferably carried out in an abrasion tester.

[0055] The invention also relates to a set of test liquids as defined in claim 10.

[0056] The invention is described in more detail below using an exemplary embodiment. Example

[0057] The following test fluids were used to test the resistance of a security document with a surface made of polycarbonate, PVC, PET and EVA to disinfectants: Group of test fluids used:

[0058] 1. Test liquid: a) 80 wt.% aqueous solution of ethanol (ultrapure, 96% minimum content)* alternatively or in addition to a) b) 70 wt.% aqueous solution of isopropanol (ultrapure, 96% minimum content)* 2. Test liquid: 95 wt.% aqueous solution of ethanol (ultrapure, 96% minimum content) + 5 wt.% petroleum benzine 40 - 65* 3. Test liquid: 98 wt.% ethanol (ultrapure, 96% minimum content) + 2 wt.% trimethyletradecylammonium bromide (biocide) (dissolved therein) *The aqueous solutions were used with deionized water. Comparison product: Sterillium commercial product

[0059] C. Security documents made of various laminated layers were tested. They had personalization printed on their PET, PVC, EVA, or polycarbonate surfaces using thermal transfer or thermal sublimation techniques, or the personalization was diffused into the surface using a special inkjet ink. In all of these different security documents, the test fluid can, in principle, dissolve the dye or ink and partially remove the personalization. D. Abrasion test with wetted cotton piece

[0060] A Quartant abrasion tester from Prüfbau was used to conduct the abrasion test. The device specifications were as follows: 0.5 N / cm 2 Scrubbing pressure, corresponds to approx. 600 g scrubbing weight 40 mm Diameter of the scouring surface (corresponding to approximately 1,250 mm 2< 5 cm Scheuerweg

[0061] The number of scrubbing cycles was 100 double strokes. Double strokes describe the double scrubbing path, which is completed once in the forward motion and then in the reverse motion. The scrubbing weight was provided with a flat piece of cotton fabric, which had previously been moistened with the test fluid to be examined.

[0062] The abrasion tests with the four different test liquids were carried out on the surface of four identical security documents, whereby a cotton fabric was wetted with one of the four test liquids 1a, 1b, 2 and 3 above.

[0063] The personalized surface of each security document was tested on the front side with a contact pressure of 0.5 N / cm2 and a round abrasive surface with a diameter of 40 mm with 100 double strokes. E. Additional test under extreme conditions:

[0064] Abrasion test after immersion in test fluid To further simulate extreme conditions, a security document was completely immersed in a test solution for five minutes. After removal, the document was blotted dry and subjected to an abrasion test within one minute as described above under D, but using a dry cotton fabric. F. Evaluation

[0065] After each test conducted according to C. or D., the readability of the personalization was visually assessed under daylight compared to an untreated security document. Security documents with low and high levels of personalization were used for this purpose. Furthermore, the security document was examined for changes such as cracks, deformations, detachments in the bond, etc. G. Results

[0066] The tests with test chemicals 1a, 1b, 2, and 3, as well as the comparative test with the commercially available reference product "Sterilium," revealed no abnormalities in the abrasion test with the moistened cotton pieces, nor in the subsequent test D. under more extreme conditions with immersion in the test liquid and subsequent abrasion test. No or only very slight changes were visible on the tested front side and its personalization. The textiles used as the abrasive medium showed no traces of color.

Claims

1. Method for testing the resistance of security documents and data carriers to disinfectants, wherein the surface of security documents or data carriers is rubbed with flat pieces of textile which have previously been wetted with a test liquid, under defined conditions, the abrasion test being carried out with at least two different test liquids and the at least two different test liquids being selected from the groups of aqueous alcoholic solutions, liquids containing hydrophobic compounds and solutions containing biocides.

2. Method according to claim 1, characterized in that as test liquid from the group of aqueous alcoholic solutions is used a solution with an alcohol content of at most 96% by weight, preferably between 50% by weight and 95% by weight and particularly preferably between 60% by weight and 90 wt.% and / or the alcohols preferably have between 1 and 14 carbon atoms and are particularly preferably selected from the group consisting of ethanol, n-propanol, isopropanol, n-, iso- or tert-butanol or butane-1,3-diol.

3. Method according to claim 2, characterized in that the first test liquid is a mixture of different alcohols, preferably an ethanol, n-propanol, propan-2-ol, n-, iso- or tert-butanol and butane-1,3-diol mixture.

4. A method according to any of the preceding claims, characterized in that the test liquid, which is a liquid containing hydrophobic compounds, contains hydrocarbons, in particular alkanes or a mixture of alkanes, preferably having a carbon chain length between 5 and 9 carbon atoms, the proportion of hydrophobic compounds in the liquid preferably being between 2% by weight and 30% by weight and more preferably between 3% by weight and 10% by weight and / or the proportion of solvent in this test liquid preferably being between 70% by weight and 98% by weight and is particularly preferred to be between 90% by weight and 97% by weight and / or the solvent is preferably an alcohol, in particular from the group ethanol, propan-1-ol, propan-2-ol, butanol or a butanediol.

5. A method according to any of the preceding claims, characterized in that the test liquid is a solution containing biocides, the biocides preferably being selected from the group consisting of quaternary ammonium compounds, such as, for example, trimethyltetradecylammonium bromide, benzalkonium chloride, ethylalkonium chloride, cetylpyridinium chloride, tetrabutylammonium hydroxide, paraquat polyquaternium-7, tetradecyltrimethylammonium oxalate or the biphenylols, the biocide concentration generally being between 0.02% by weight and 5 wt.%, preferably between 0.5 wt.% and 4 wt.%, and most preferably 1 wt.% to 3 wt.%, and / or the solvent is a hydrophilic solvent or a hydrophilic solvent mixture, such as water or an alcohol, in particular ethanol.

6. A method according to any one of claims 1 to 5, characterized in that the abrasion test is carried out with at least three different test liquids from the groups defined above and the at least three different test liquids preferably belong to three different groups of test liquids and / or two test liquids are from the group of aqueous alcoholic solutions.

7. Method according to claims 1 to 5, characterized in that at least two or three different test liquids belong to different groups of test liquids.

8. A method according to one of the preceding claims, characterized in that the flat textile is a planar structure such as a woven fabric, knitted fabric, mesh, braid, stitch-bonded fabric, nonwoven fabric and felt of limited extent and in particular a cotton fabric.

9. A method according to any of the preceding claims, characterized in that the security documents or data carriers are personalized by printing on the surface by means of thermal transfer or thermal sublimation processes or by using a special inkjet ink that diffuses into the upper layer, and / or the surface of the security document or data carrier is made of plastic, paper, and in particular of polycarbonate, PET, EVA or PVC.

10. Set of test fluids for carrying out the test of the resistance of security documents and data carriers to disinfectants in a process according to one of claims 1 to 9, wherein the set consists of at least two different test liquids from the groups of aqueous alcoholic solutions, of liquids containing hydrophobic compounds and of solutions containing biocides.