AU711831B2 - A printing process for a package of pre-printed laser security document blank forms - Google Patents

Description

1 P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: A PRINTING PROCESS FOR A PACKAGE OF PRE-PRINTED LASER SECURITY DOCUMENT BLANK FORMS The following statement is a full description of this invention, including the best method of performing it known to us: GH REF: P21769F:PJT/MB 2 A Printing Process for a Package of Pre-Printed Laser Security Document Blank Forms This invention concerns a printing process, and in particular a pre-printed process for producing tamper-resistant laser printed documents including anti-counterfeiting printing on its surface.

Modern technology has made it possible for a large number of people to counterfeit security and other important documents, and as a counter-reaction to this, there is a continuing need for new built-in security features to prevent such documents (particularly laser printer produced cheques) from being tampered with after they have been printed, or at least, of making such tampering difficult to disguise.

s. 15 One of the problems in this regard is that laser printer machines with Toners and Fusers provide a hostile environment for both paper and printing ink, in that the paper and ink has to withstand temperatures of 210 0 C and pressures of 140psi at dwell times of 34 milliseconds.

20 Some laser printing machines also use high molecular weight silicone lubricants during processing which partially solubilise normal printing inks causing

S.

unwanted marking on the sheet and the build-up of ink within the laser printer. This leads to further stresses on the preprinted forms during the "feeding" process through the laser printing machine which can cause malfunctions and breakdowns with resultant losses in productivity.

It is an object of the present invention to provide for an improved form of creating a document blank for laser printing which alleviates some of the aforementioned difficulties in the printing process.

In accordance with a first aspect of the present invention there is provided a method of creating a document blank for laser printing, the method comprising the steps of: printing first identification information utilising an invisible ink comprising a solubilised S:P21 769F 3 dispersion of 2-aminobenzothiozole in a castor oil and phenolic resin solution; printing second identification information utilising an invisible ink formulated with optical brighteners, said second identification information being ultra-violet visible; printing background identification information utilising a first colourant dispersed in laser varnishes containing castor oil and phenolic resins.

Further, the method preferably includes the step of utilising a red ink colourant having a defined measurable Print Contrast Signal to print positioning or highlighting information on the document blank.

Preferably the red ink colourant comprises a Di 15 arylyde Pyrazalone and Calcium Salt Mono Azo Hydroxy Naphthoic Acid in a laser ink varnish.

[:%Preferably the first colourant comprises one of the group of copper phthalocyanine, alumina tartrazine yellow, or copper ferrocyanide blues, greens or pink.

20 The method of the preferred embodiment can further include the step of printing a cyan background on the document blank and subsequently passing the document blank through a dedicated in-line perforation unit to achieve a smooth flat perforation of said document blank.

The preferred embodiment discloses the application of a five unit lithographic printing process to render a tamper-resistant laser security cheque as a A4 perforated form document.

Anti-counterfeiting measures are incorporated into the design by a combination of chemically reactive inks and invisible inks which are rendered visible by black ultraviolet light, erasable inks readily erasable with rubber erasers on papers which instantly bleed when spotted with solvents such as alcohols, acetone, methyl ethyl ketone, ethyl acetate, aliphatic and aromatic hydrocarbons, acids and alkalis, sodium hypochlorite, bleach or ink removers.

Furthermore, by a judicious combination of S:P21769F 4 photographic screens and screen angles into a design, a latent non-visible image word can be introduced into the cheque background pattern which will be rendered visible when photocopied.

The process of the preferred embodiment also embodies the use of an "open rectangular data box" printed with a special red ink for printing imagecompatible documents. This ink has a measured printcontrast-signal so as to create a high contrast with the data and facilitate accurate and fast data transcription.

The paper utilised with the preferred embodiment has to have the right tensile strength specifications for use in the lithographic process. Preferably, it is relatively free of optical brighteners; has excellent 15 curl control; uniform porosity; smooth surface characteristics; free of paper dust debris; a moisture level of 5% static free, and produced within tight tolerances of stiffness and thickness of batch uniformity. The weight of the paper in grams per square 20 metre should be 90-92 gsm. The surface of the paper should be chemically sensitive to a broad range of solvents, acids, alkalis, bleaches, etc.

*It is assumed that the final desired A4 form is to be presented in long-grain paper format.

The paper is then subjected to a pre-laser printing process. The pre-printing process is conducted on a high speed lithographic sheet fed press capable of applying five inks on five individual units. The press should include the usual electronic monitoring and computer print control technology to print at the highest levels, including registration accuracy. The press must have the use of isopropyl alcohol in the fountain solution to ensure uniform and correct levels of ink film density and minimum water uptake into the printed sheet. Equally so, the choice of exceptional positive anodised aluminium plates and compressible rubber blankets is of great importance.

All inks used should be non-volatile and formulated S:P21769F for withstanding laser printing. They hence should be able to withstand temperatures of 210 0 C and pressures of 140psi. They should not contain waxes or silicones, volatile or halogen components, ketones or esters. They should have high heat resistance and no thermo plasticity, nor do give off any fumes or odours. The inks should be resistant to the silicone lubricant used with the fuser roller in laser printers. In addition, they should not be affected by resin components contained in laser toners and should be non-flammable.

The printing process may then proceed as follows: Press Unit i: The first unit of the press uses an invisible ink comprising a solubilised dispersion of 2 aminobenzothiozole in 15 a castor oil and phenolic resin system.

The printing plate is prepared with the word "VOID" printed in a random pattern all across and over the background of the A4 sheet which is to form a cheque.

20 Press Unit 2: The second unit will also be printed with a secondary laser invisible ink formulated with optical brighteners.

This is printed with a plate containing, for example, below and across the bottom of the cheque wording identifying the source of the cheque, e.g. "Queensland Credit Union" Printing Unit 3: A red ink colourant based on Di arylyde Pyrazalone and Calcium salt Mono Azo Hydroxy Naphthoic Acid in a laser ink varnish is printed as a red screen dot in an open rectangular box, where the figure amount of the cheque has to go, towards the middle right of the cheque.

This ink preferably has a defined measurable Print Contrast Signal (PCS) which can be analysed by an Image Qualifier.

S:P21 769F 6 Printing Unit 4: A cyan plate is then printed in the main body of the form (quite separate from the cheque component area) and can be, for example, a screened version of an emblem logo.

Printing Unit 5: The final printing unit uses a copper phthalocyanine colourant dispersed in laser varnishes containing castor oil and phenolic resins. The subject matter printed forms the background colour and design pattern of the cheque itself.

For example, incorporating a reversed image of the owner source name in Sreverse lettering together with a 15 pattern (which can be swirl, leaf or box n. *or the like which conceals a hidden latent image not discernible to the eye.

(The colourant could also be based on alumina tartrazine yellow or copper 20 ferrocyanide blues, greens or pink) Post Printing: After all five units of the lithographic printing press have completed the application of the five inks and appropriate subject matter, the paper passes through a dedicated in-line perforation unit to achieve a smooth flat (8 teeth to the inch) perforation between the letter part and the cheque part of the document.

No spray powder or other forms of accelerated heat or drying processes should be used as they adversely affect moisture content of the paper and runnability of the printed product through the laser printing machines.

All printing and post-printing processes should be controlled in an environment temperature of 20 0 C 2 0

C

and a relative humidity of 50% Cutting and Packaging: The printed sheets are guillotined with S:P21769F 7 tungsten blades to give ultra smooth, debris-free cuts and with a measured moisture control of 5% 0.5% of the printed product, they are packaged in lots of 500 A4 forms to a ream, topped and bottomed with an 1800uhm thickness unlined box board material for protection and shrinkwrapped in heat sealable multi-layered film of microns thickness sheets of molecular structured cross-linked polyolefin film to control the packaged ream's moisture vapour transmission rate.

.006%Four such reams (4 x 500) are placed in a carton 15 with lid so that movement in the box is held to a minimum and protection of ream damage is achieved in transit to the user.

:The pre-printed laser security A4 cheque form can then be utilised for processing in a laser printer 20 to print text on the top letter portion and to print the "cheque" information below the perforated segment of the cheque itself which can also have suitable built-in antiforgery characteristics to protect against colour Scopying. Examples of anti-counterfeiting techniques are those disclosed in Australian Patent No. 35688/78 to I Burroughs Corporation and Australian Patent No. 29915/92 to Moore Business Forms, Inc.

Excellent runnability in laser printers was found in the final product.

The final product was found to further have excellent tamper-resistant and anti-forgery characteristics. These include: As a result of the steps carried out by press unit i, the invisible words "VOID" embodied in the cheque format become almost immediately visible as a brown stain when any tampering of the surface of the cheque was attempted with bleach or sodium hypochlorite or "Milton" fluid.

S:P21769F 8 As a result of the steps carried out by press unit 2, the invisible words identifying cheque ownership such as "Queensland Credit Union" printed directly on the paper below the coloured cheque background fluoresced to visible blue under a black ultraviolet illumination light source.

As a consequence of the steps carried out by press unit 5, if a plastic or rubber eraser is used to remove any printed or written matter, the coloured ink coating will immediately showed strong evidence of erasure.

Any solvents, acids, alkalis, ink remover or chemicals used to erase any portion of the cheque immediately showed up as a strong bleed and dramatic ***change in colour characteristics.

15 It would be appreciated by a person skilled in the art that numerous variations and/or modifications may be .o made to the present invention as shown in the specific embodiment without departing from the spirit or scope of the invention as broadly described. The present 20 embodiment is, therefore, to be considered in all respects to be illustrative and not restrictive.

go S:P21769F

Claims (8)

1. A method of creating a document blank for laser printing, said method comprising the steps of: printing first identification information utilising an invisible ink comprising a solubilised dispersion of 2-aminobenzothiozole in a castor oil and phenolic resin solution; printing second identification information utilising an invisible ink formulated with optical brighteners, said second identification information being ultra-violet visible; printing background identification information utilising a first colourant dispersed in laser varnishes containing castor oil and phenolic resins. 15

2. A method as claimed in claim 1 further comprising the step: utilising a red ink colourant having a defined measurable Print Contrast Signal to print positioning or highlighting information on said document blank. 20

3. A method as claimed in claim 2 wherein said red ink colourant comprises a Di arylyde Pyrazalone and 5 Calcium Salt Mono Azo Hydroxy Naphthoic Acid in a laser ink varnish.

4. A method as claimed in claim 1 wherein said first colourant comprises one of the group of copper phthalocyanine, alumina tartrazine yellow, or copper ferrocyanide blues, greens or pink.

A method as claimed in any preceding claim further comprising the step of printing a cyan background on said document blank.

6. A method as claimed in any preceding claim further comprising the step of passing said document blank through a dedicated in-line perforation unit to achieve a smooth flat perforation of said document blank.

7. A document blank when created by the method as claimed in any preceding claim. S:P21769F 10

8. A method of creating a substantially as hereinbefore described. document blank Dated this 1st day of May 1997 J S MCMILLAN PRINTING GROUP By its Patent Attorneys GRIFFITH HACK CO. 4* S S S. S SS 4 S *SeSS. S S S V 5 S 5.5. S:P21 769F