GB2060491A - Security Document - Google Patents

Abstract

In at least an area for handwriting, a document has a primary printing which will exhibit evidence of attempts at erasure by a solvent or chemical eradicator for the printing ink used and a secondary printing which is at least partially erasable by the use of mechanical erasing means such as an india rubber. Preferably, the secondary printing overlies the primary printing and the two printings are of different configurations so that each of them can be recognized.

Description

SPECIFICATION Security Documents This invention relates to printed security documents, for example bank cheques, travellers' cheques, airline tickets and other documents which are adapted for the insertion by hand of names, signatures, amounts of money or other information of a peculiar or personal nature and which are sensitive to attempts to alter the inserted information. The invention is particularly directed to such documents printed with sensitive inks and to inks having sensitive characteristics. By "sensitive" we mean that an attempt to alter the inserted information results in a noticeable-change in the appearance of the document so as to alert a person receiving it to the fact that the document has been altered.

Already known are safety papers and safety printing inks and techniques which are reasonably sensitive to attempted eradication of both conventional liquid inks, that is inks consisting of colouring material dissolved in water, and ballpoint type inks which typically consist of one or the higher glycols as a vehicle with an aniline dye for colouring material.

The eradication referred to in the preceding paragraph is particularly solvent or chemical eradication but protection against mechanical erasure has also to some extent been achieved by incorporation of special materials e.g. fluorescent pigments in the area to be protected so that attempted alteration by mechanical erasure gives a reduction in the intensity of fluorescence. However, the detection of fluorescent materials requires the use of an ultra-violet light source and this may not always be available when a document is examined.

Recently, ballpoint pens with special erasable inks, which are hereinafter referred to as "time setting" inks, have come into public use. For example, U.S. Patent No. 4,097,290 discloses ballpoint writing which is capable of producing a trace which is potentially as permanent as those produced by conventional inks, but which is easily erasable by mechanical means (for example by a normal rubber) during an initial period of about two hours.

Thus, it will be appreciated that security documents bearing written information of this latter kind are particularly vulnerable to fraudulent practices by mechanical erasure of the original information and the subsequent insertion of other information.

It is, therefore, the object of the present invention to provide an improved security document which may readily exhibit evidence of attempts to remove or alter information which has been applied to the document, for example, by handwriting.

According to this invention, a printed security document comprises in at least an area thereof for the receipt of ink-applied handwriting, a primary printing which will exhibit evidence of attempted erasure by the application thereto of a solvent or chemical eradicator for the printing ink thereof and a secondary printing which is at least partially erasable by the application thereto of mechanical erasing means.

Preferably the solvent or chemical eradicator is also a solvent or chemical eradicator for handwriting inks comprising high boiling range vehicles such as diols and glycols in combination with oil-soluble or solvent soluble dyes.

Preferably the secondary printing overlies the primary printing and the two printings are of different configuration thereby to enable each of them to be recognized.

Preferably, the security document is of the travellers' cheque type and includes at least one said area for the receipt of handwriting.

Preferably also the primary printing is capable of: a) deforming under the pressure of handwriting to trap or interlock with ink used in the handwriting and especially with ballpoint pen ink.

b) being wetted by handwriting inks, especially ballpoint pen inks.

c) showing visible colour changes when subjected to solvents or chemical eradicators for ink used in handwriting.

d) enhancing legibility of the handwritten information by providing an improved surface, as compared with unprinted paper, for the receipt of handwriting.

The ink composition for the primary printing may be applied in continuous or discontinuous phase. According to the nature of the composition it may be applied by one or more of the letter press, dry offset, gravure, flexographic or other printing processes.

In one form, the ink for the primary printing may comprise a film forming glycol-thinnable resin and dyes which provide colour and reactivity to solvent and chemical eradicators. Preferably also, this ink includes additives which will enhance the wettability by and compatability with inks used in handwriting, especially ballpen inks of the above mentioned "time-setting" type; typically these additives are long chain alcohols, anionic Turkey red oil or non-ionic wetting agents e.g. polyethylene glycol based materials.

In another form the primary printing ink composition is one particularly suitable for the flexographic or gravure processes and is based on synthetic rubber latex type compounds as a binder constituent, a clay type filler, reactive additives in the form of dyes which are sensitive to eradicators or solvents and, as required, flow modifiers and dispersing agents. Such an ink may be colourless, white or invisible in relation to the substrate when applied.

The said secondary printing may be of any convenient configuration well known in security printing. For example, it may comprise an array of parallel straight or curved lines, or more preferably it may be in the general form of a grid, screen or interlaced pattern thereby to provide a large number of intersection points with the handwritten information Alternatively, it may comprise closely disposed rows of microcharacters or symbols. In all cases however, the said printing should be sufficiently coarse to be easily visible. The secondary printing requires to have a high degree of compatibility with the primary printing and, although deformable under conditions of mechanical erasure, be sufficiently stable under conditions of normal handling to withstand rub-off and degradation of print quality during the preparation and use of the document.

The secondary printing may be carried out by means of any suitable letter press, dry offset, gravure, or flexographic process or by the intaglio direct plate process which is used for the production of high quality security documents. In the latter case the intaglio pattern is desirably of a fine line type in order not to make difficult the application of handwriting thereto.

In one form the ink composition for the secondary printing may comprise a blend of drying and non-drying oils which is pigmented by conventional pigments and includes a substantial proportion of wax compounds. The drying oil component is provided to give surface drying of the final print as well as to form part of the vehicle for the pigments. The wax compound is present in far higher proportions than is normally found in printing inks in order to confer on the dry printed ink a high degree of deformability.

Such an ink may be described as soft when in its printed form but nonetheless may be selected so as to be stable and permanent under normal conditions of manufacture and use of security documents.

In another form, suitable for use with the intaglio direct plate process, the secondary printing ink may be of a kind which is known for the production, by the said intaglio process, of security documents which by nature of their intended use have a resistance to rubbing which is relatively low as compared with that required by security documents such as banknotes. Impressions made from such inks are well suited to accepting/entrapping ink applied by handwriting, e.g. by ballpoint pens and, because of their relatively low resistance to rubbing, they will readily show signs of the mechanical erasure of handwriting thereupon.

The ink compositions of either or both the primary and secondary printings may include a fluorescent material thereby to enable weil-known security testing techniques to be applied to documents printed therewith.

By way of example afirstinkforthe primary printing may comprise a dye (0.1 to 10%); resin solids (35 to 50%); glycol diluent (35 to 60%); and a wetting agent (0.1 to the percentages being on a dry weight by weight basis. In specific form one such ink comprises Ink 'A' Dye Percent Auramine (ex F.A. Bayer-German) 2.4 Maxillon Brilliant Orange (ex Ceiba Geigy) 1.6 F.P. 777 Fluorescent additive (ex Sterling Chemicals) 4.0 Resin Solids Hercules (trade mark) resin M230 41.4 3-ethanolamine as plasticizer and pH modifier 9.2 Glycol Diluent Diethylene Glycol 36.4 Wetting Additive ICI (trade mark) Dispersal Flake 5.0 A second ink for the primary printing which is especially suitable for flexographic/gravure types coating and, if desired, for providing a printing which has tonal qualities matching those of the substrate may comprise a binder (10-30%); a co-binder (2 to 6%); filler (60 to 80%); an additive which is reactive to a solvent or chemical eradicator (1 to 2%); a flow modifier (0.1 to 1.0%) and a dispersing agent (0.5 to 1 .5%)-the percentages being on a dry weight by weight basis. A typical ink formulation may include 40 to 70% of the dry ingredients listed above and correspondingly water to between 60 and 309/0. In specific form the dry constituents of such an ink comprise, by way of example: Ink 'B' Binder Percent (styrene butadiene rubber latex (SBR) or acrylic latex or styrene acrylic latex) 18 Co-binder (starch or dextrine) 3 Ink 'B' (cont.).Percent Filler Mix (comprising clay of high absorbency and medium to high particle size filler of high absorbency such as calcium carbonate) 76 Reactive Additive (encapsulated dyes which are sensitive to solvent eradicators) 1.5 Flow Modifier (high viscosity polyacrylate or polyvinyl alcohol or carboxymethyl cellulose) 0.5 Dispersing Agent (low viscosity polyacrylate phosphates or Calgon (trade mark) (Sodium Lexametaphosphate)) 1.0 By way of example, a first ink for the secondary printing may comprise a drying oil (50 to 80%); non drying oil (5 to 30%);a pigment (1 to 15%); wax additive (1 to 12%); and a dryer catalyst (0.1 to 1 .0%)-the percentages being on a dry weight by weight basis.In specific form one such ink comprises:- Ink'C' Percent Drying oil (drying oil alkyd) 60 Non-drying oil (castor oil) Pigment (Monastral Blue BS) 8 WaxAdditive Carnauba Wax 3.5 Paraffin Wax 3.5 Bedesol 599 (trade mark) (drying oil alkyd) 3.0 Petroleum distillate 260/290 1.5 Dryer catalyst (cobalt naphthenate) 0.5 A second ink for the secondary printing which is suitable for the intaglio direct plate process is exemplified, as a red ink, as follows Ink'D' Percent on Dry wtlby wt Basis Permanent Red 2244 (ex A. B. Fleming Limited) 6.0 Liberty Red DC 37601 (ex S.C.C. Company Limited) 6.0 Cromophtal Bordeaux (ex Ceiba Geigy) 4.0 Printer's White (alumina hydrate) 1.5 Whiting (calcium carbonate) 14.0 Blanc Fixe (barium sulphate-fine particle) 22.0 Intaglio Varnish (5-7 poise) (ex U.S.Varnish Corporation) 13.5 Barytes (barium sulphate) 24.5 Gel Alkyd (ex Cray Valley Products Limited) 4.0 Wax Mixture comprising: Carnauba wax Paraffin wax Drying oil alkyd Petroleum distillate 260/290

3.0 Driers 1.5 Travellers' cheques, each comprising an area for the application of signatures which contains a primary printing and an overprinted secondary printing, were prepared as follows:- Cheque I With the primary printing as a solid rectangle applied by the dry offset process using Ink 'A' and with the secondary printing also applied by the dry offset process as a diamond grid pattern made up from two sets of parallel lines disposed at 1 mm pitch using Ink 'C'.

Cheque II With the secondary printing as for Cheque I but with the primary printing thereof replaced by a discontinuous printing of Ink 'B' applied by the flexographic process.

Cheque Ill With the primary printing of Cheque I but with the secondary printing thereof replaced by a fine line intaglio printing, by the direct plate process, of Ink 'D'.

Two cheques of each of Cheques I, ll and Ill were signed across their signature panel areas using a time-setting ink.

Within an hour an attempt was made to remove the signature from one cheque of each pair by means of a rubber eraser. In all cases this resulted in erasure of the signature but also removal of the secondary printing in the vicinity thereof. This removal was readily discernible to the human eye.

All attempts to remove the signatures of the other of each pair of cheques by means of chloroform successfully removed the signatures but also, by its effect on the primary printing, resulted in a clear and obvious indication of chemical tampering.

Claims (14)

Claims

1. A printed security document comprising in at least an area thereof for the receipt of ink-applied handwriting, a primary printing which will exhibit evidence of attempted erasure by the application thereto of a solvent or chemical eradicator for the printing ink thereof and a secondary printing which is at least partially erasable by the application thereto of mechanical erasing means.

2. A security document as claimed in Claim 1 in which the secondary printing overlies the primary printing and the two printings are of different configurations.

3. A security document as claimed in either of Claims 1 and 2 in which the printing ink of the primary printing is soluble or eradicatable by a solvent or eradicator for handwriting inks comprising high boiling range vehicles, such as diols or glycols, in combination with oil-soluble or solvent soluble dyes.

4. A security document as in any one of the preceding claims in which the primary printing is applied by a process selected from the letterpress, dry offset, gravure and flexographic processes and the secondary printing is applied by a process selected from any of the foregoing processes and the direct plate intaglio process.

5. A security document as claimed in any one of the preceding claims in which the primary printing provides a solid continuous coating of ink.

6. A security document as claimed in any one of Claims 1 to 4 in which the primary printing provides a discontinuous coating of ink.

7. A security document as claimed in any one of the preceding claims in which the primary printing comprises a coloured ink.

8. A security document as claimed in any one of Claims 1 to 6 in which primary printing comprises an ink having tonal qualities similar to those of the substrate of the document.

9. A security document as claimed in one of the preceding claims in which the secondary printing comprises a fine grid pattern suitable for handwriting thereupon.

10. A security document as claimed in any one of the preceding claims in which the ink of the primary printing includes a dye or similar material which becomes visible upon the application of said solvent or chemical eradicator.

11. A security document as claimed in any one of the preceding claims in which the ink of the secondary printing comprises a wax within the range 1 to 12% on a dry weight basis.

12. A security document as claimed in any one of the preceding claims in which the ink of either or both the primary and secondary printings includes a fluorescent material.

13. A security document as claimed in any one of the preceding claims in the form of a travellers cheque.

14. A security document substantially as described in any one of Examples I to III hereof.