(12) United States Patent

Transcription

1 USOO B2 (12) United States Patent Mehta et al. () Patent N.: (45) Date f Patent: Jan. 7, 2014 (54) CHEMICALLY REACTIVE SECURITY INK, A METHOD OF USE OF SUCH INK, AND SECURITY DOCUMENTS INCORPORATING SUCH INK (75) Inventrs: Rajendra Mehta, Daytn, OH (US); Steven L. Yeager, Daytn, OH (US); Stephen D. Webendrfer, Miamisburg, OH (US) (73) Assignee: The Standard Register Cmpany, Daytn, OH (US) (*) Ntice: Subject t any disclaimer, the term f this patent is extended r adjusted under 35 U.S.C. 154(b) by 1682 days. (21) Appl. N.: 11/754,630 (22) Filed: May 29, 2007 (65) Prir Publicatin Data US 2007/O A1 Dec. 6, 2007 Related U.S. Applicatin Data (60) Prvisinal applicatin N. 60/8,086, filed n Jun. 1, (51) Int. Cl. B42D IS/TO ( ) B4LM 5/04 ( ) B4LM 3/4 ( ) B44F L/12 ( ) G09C 3/ ( ) C09D II/00 ( ) (52) U.S. Cl. USPC /96: 283/72; 428/195.1; 427/7; 6/31.27: 6/31.28; 6/31.44 (58) Field f Classificatin Search USPC... 6/31.27, 31.28, 31.44; 283/93, 72, 283/95, 96; 523/160; 524/594; 427/7 See applicatin file fr cmplete search histry. (56) References Cited U.S. PATENT DOCUMENTS 3,5,385 A * 5/1970 Lythge et al /29 5, A * 3/1993 Mwry et al ,209,515 A 5/1993 Dtsn et al. 5,340,159 A * 8/1994 Mwry, Jr ,601,683 A 2, 1997 Martin 5,636,874 A 6/1997 Singer 6,306,929 B1 /2001 Amn et al. 2005/ A1 3/2005 Mehta et al , 1951 FOREIGN PATENT DOCUMENTS EP GB A1 * A * 3, , 1999 WO WO 2005/ A1 * 5, CO9B 67/08 * cited by examiner Primary Examiner Mark Ruthksky Assistant Examiner Laura C Pwers (74) Attrney, Agent, r Firm Dinsmre & Shhl LLP (57) ABSTRACT A dcument uses a chemically reactive security ink t facili tate security, making it mre difficult t alter a genuine Secu rity dcument. The chemically reactive security ink masks a warning wrd r message n a security dcument. The hidden warning wrd r message is revealed when the dcument is Subjected t chemical washing. 23 Claims, 4 Drawing Sheets

2 U.S. Patent Jan. 7, 2014 Sheet 1 f ZZZZZZYZZZZZY ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ F.G. 1 % 13 YE 16 S Z, 2 27 Z2 2 3zzzzzzzzzzzzzzzzzzzzzzzzzzzzz!) 2ZZZZZZZZZZZZZZZZZY al 7 ZZZZZZZZZZZZZZZZZZZZZZZZZ ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ2 244 % 3. 2O m Azazi 2% m 2 zzzzzzzzzzzzzzzzzzzzzzz!, 2Z2 1. FG, 2

3 U.S. Patent Jan. 7, 2014 Sheet 2 f 4 w g C s 0. P O u O O d O cc d? t e e. s c c s d c d Y d c FG. 3 FG. 4 O F.G. 5 this message DO NOT CASH THIS CHECK F.G. (3

4 U.S. Patent Jan. 7, 2014 Sheet 3 f 4

5 U.S. Patent Jan. 7, 2014 Sheet 4 f 4

6 1. CHEMICALLY REACTIVE SECURITY INK, A METHOD OF USE OF SUCH INK, AND SECURITY DOCUMENTS INCORPORATING SUCH INK CROSS-REFERENCE TO RELATED APPLICATIONS This applicatin claims the benefit f prvisinal patent applicatin Ser. N. 60/8,086, filed Jun. 1, 2006, under 35 U.S.C STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH ORDEVELOPMENT Nt applicable. BACKGROUND OF THE INVENTION The present inventin relates t chemically reactive Secu rity ink, a methd f using Such ink, and dcuments incrp rating Such ink, and mre particularly t Such ink, methd, and dcuments in which fraudulent changes t security dcu ments may be made bvius. A number f appraches have been taken in the past t thwart r reduce the fraudulent mdificatin f security dcu ments. It has been cmmn fr criminals t mdify a security dcument, fr example increasing the value f a bank check, by applying a slvent t the security dcument t remve a prtin f the valid written infrmatin frm an area f the dcument and then typing, printing r writing altered infr matin int the same area n the dcument. Varius appraches have been taken in an attempt t make Such dcu ment alteratins nticeable and, therefre, ineffective. U.S. Pat. N. 6,306,929 teaches a bleeding ink that is used fr printing security dcuments. The 929 patent disclses bleed ing inks having nn-drying vehicles, as well as using dye stuffs sensitive t rganic slvents and ther chemical agents. The 929 patent suggests the same dyes used in knwn bleed ing inks, such as Slvent Blue 67. U.S. Pat. N. 5,601,683 t Martin teaches printing a vid pantgraph in dye-based, slvent-sensitive inks that wash away with acetne r bleach. U.S. Pat. N. 5,209,515 t Dtsn etal teaches a slvent sensitive ink which reacts t the applicatin f a slvent r pressure t frm a visible stain, image, r warning indicia, such as fr example the wrd "VOID". It may be printed as repeating text, a spt, r as a full cating. The 515 patent disclses an ink that changes frm clrless t a clr, prviding a cvert Security feature. The ink remains invisible until it is attacked by slvent. It is knwn that sme slvent-sensitive vid catings f this srt will wash away cmpletely if saked lng enugh. U.S. Pat. N. 5,636,874 t Singer teaches a feature that can be used fr authenticatin and validatin. Temperature-sen sitive ink is printed ver a temperature-insensitive message, bth inks being f the same clr. When the dcument is rubbed r heated, the temperature sensitive ink turns clrless and this reveals a message such as VALID' underneath. Upn cling, the clr returns nce again, masking the message. Varius chemically reactive inks have been used fr secu rity purpses. Bleeding inks, erasable inks, cin-reactive inks, transparent inks, pen-reactive inks, transparent inks, heat reactive reversible and irreversible inks, infrared inks, ptically variable inks, phtchrmic inks, and ultravilet invisible flurescent inks all ffer ways f either authenticat ing by effecting a change in appearance under cntrlled circumstances, r prvide prtectin against fraud by making undetected alteratin mre difficult. In anther alteratin technique, called check washing, a check is fraudulently altered after washing it with any f a number f chemical cleaners t remve the valid data. This mst cmmnly ccurs with handwritten checks. Check washing is less cmmnly used with cmmercial checks that are printed with a tner ink, since a slvent may nt be as effective as scraping and picking the tner frm the check Surface mechanically. It is seen, therefre, that a need exists fr an imprved ink and methd fuse f such ink, as well as an imprved security dcument, in which alteratins t the security dcument are made mre bvius such that the fraudulent use f the dcu ment is prevented r made mre difficult. SUMMARY OF THE INVENTION This need is met by a chemically reactive security ink, substantially as disclsed and described herein. The chemi cally reactive security ink cmprises a slvent sluble dye, and a nn-drying vehicle r ink base. The slvent sluble dye may be selected frm the grup f az, Xanthene, anthraquinne, triarylmethane, azine, thiazine, phathalcyn ine, and metal cmplexes f the same. The slvent sluble dye may cmprise a slvent sluble dye selected frm the grup f slvent black 3, slvent black 5, slvent red 23, slvent red 132, slvent red 8, slvent red 49, slvent red 89, slvent red 122, slvent blue 4, slvent blue 5, slvent blue 35, slvent blue 44, slvent blue 45, slvent blue 59, slvent blue 97, slvent vilet 9, and slvent vilet 8. The slvent sluble dye in the ink may be between 0.1% and 20% by weight, and mre preferably between 1% and 8% by weight. The nn-drying vehicle r ink base may cmprises a blend f tw r mre f tall il butyl ester, mdified phenlic resin, silica, and calcium stearate. The resin may cmprise frm % t 60% f the nn-drying vehicle r ink base by weight, and mre prefer ably frm 32% t 45% f the nn-drying vehicle r ink base by weight. The il may cmprise frm 30% t 90% f the nn-drying vehicle r ink base by weight, and mre prefer ably frm 40% t 65% f the nn-drying vehicle r ink base by weight. The silica may cmprise frm 0% t 15% f the nn-drying vehicle r ink base by weight, and mre prefer ably frm 6% t 9% f the nn-drying vehicle r ink base by weight. The calcium stearate may cmprise frm 0% t 6% f the nn-drying vehicle r ink base by weight, and mre pref erably frm 1% t 3% f the nn-drying vehicle r ink base by weight. The ink may include ne r mre additinal slvent dyes. Further, it may include a bleach reactive chemical. A security dcument incrprates the chemically reactive security ink, and cmprises a dcument Substrate, a message n the Substrate, and a slvent sluble masking ink printed ver the message. By this arrangement, when the masking ink is remved as a result f the applicatin f slvent, the mes sage becmes visible. The message may be a warning mes sage that nly becmes visible after slvent is applied t the masking ink. The message may be printed n the Substrate adjacent an area that carries handwritten infrmatin. The message may be printed in a pantgraph pattern, and with the masking ink als printed in a pantgraph pattern. The mes sage may be printed adjacent ne r mre infrmatin areas n the security dcument, arund the periphery f ne r mre infrmatin areas n the security dcument, r in ne r mre infrmatin areas n the security dcument. The security dcument may be a bank check having a frnt face and a rear face, with the message being printed n the

7 3 frnt face f the bank check adjacent t r in at least ne f a written amunt area, a numerical amunt area, a payee area, and a MICR accunt and ruting number area. The security dcument may be a bank check having a frnt face and a rear face, with the message being printed n the rear face f the bank check adjacent t r in an endrsement area. It will be appreciated that it is an bject f the present inventin t prvide a security ink and a security dcument carrying Such ink in which the dcument is prtected against nefarius alteratin r change. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 illustrate the pssible placement patterns f the ink f the present inventin n a security dcument, Such as a check; FIGS. 3 and 4 illustrate the appearance f the patterned Slvent sensitive ink masking a VOID message, and with the masking ink remved, respectively; FIGS. 5 and 6 illustrate the appearance f the patterned Slvent sensitive ink masking a warning message, and with the masking ink remved, respectively; FIG. 7 shws ne psitin f a slvent sensitive ink ver a hidden message in a bank check with the additin f ther security features, including an anti-cpy pantgraph and a thermchrmic authenticatin insignia; and FIG. 8 shws anther psitin f slvent sensitive ink ver a hidden message in a bank check with the additin f ther security features, such as laid lines printed n the back f the check. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventin relates t a chemically sensitive security ink, and the use f suchink n secure dcuments. The security ink, when expsed t a slvent, changes clr, r changes between a clred and clrless state. This change in clr r paqueness can prvide an indicatin f tampering with a dcument, r can be used t authenticate a dcument. The ink has the advantage f being reactive with a wide variety f slvents plar, nnplar, aliphatic, armatic, xygenated, and halgenated. Further, the ink can be used n dcuments that will Subsequently be prcessed thrugh laser printers. The inventin als cntemplates printing a slvent sensi tive ink ver a message n a security dcument in rder t mask r t bscure the message. The message is preferably printed in a slvent resistant ink. The message remains hidden until the masking ink is expsed t Slvent and its clr remved. The slvent sensitive ink f the present inventin is preferred as the masking ink, but ther slvent sensitive inks are als cntemplated. An exemplary use in this fashin is n security dcuments, such as certificates f title, bank checks, currency, birth certificates, negtiable dcuments, gift certifi cates, cllege transcripts, and the like. The message culd be used t indicate an attempt t alter the security dcument thrugh the use f the slvent. Other uses fr the hidden message arrangement, including authenticatin, will als be apparent. In ne versin f the security dcument, having a hidden message, if the security dcument has a backgrund printed as pantgraph, the message is preferably printed in the same ink as the pantgraph. Pantgraphs are typically printed by wet ffset, lithgraphy, r rtgravure printing prcesses, and are typically printed with inks that are relatively impervius t slvents nce cmpletely cured r dried. The message prtin f the dcument may be in narrative frm, such as fr example, If yu can read this message, this dcument has been cmprmised. Alternately the message may simply be Tamper-Alert. VOID r a graphic f sme srt. The message may be printed anywhere n the security dcument, including its frnt and rear Surfaces. Preferably, the masking ink and message ink are the same clr. The preferred masking ink utilizes a nn-drying vehicle Such that it remains pen t being sensitive t slvents. The ink may als bleed thrugh t the ppsite side f the paper, creating feature that is difficult t duplicate if an attempt is made t replicate the frm with a cpier r scanner. While nn-drying, the ink is cmpatible fr use n dcuments being prcessed thrugh laser printers. The security dcuments preferably cntain multiple secu rity features t thwart criminal attempts at altering r dupli cating the frm. Using mre features results in mre rbust fraud prtectin. Such features may include any cmbinatin feature, such as a Vid pantgraph fr anti-cpy prtectin, thermchrmic ink fr validatin r authenticatin purpses, laid lines t prevent cut and paste fraud, Slvent sensitive catings, printings, r speckles that g frm clrless t clr upn attacks frm Slvents, water marks, security threads, clred paper fibers, high reslutin brders, micrprinting, and any ther f a large number f security features that are knwn in the art. The chemically reactive security ink f the present inven tin may als be used apart frm bscuring a hidden message. Fr example, it may be used as a bleeding numbering ink. It may be used fr printing lines r brders arund certain fields f a security dcument such as the payee field, cnvenience amunt field, written amunt field, MICR accunt field, r ther fields f a bank check. This nvel chemically reactive security ink can be applied by wet ffset lithgraphy and letterpress t any dcument needing a security feature that makes it evident t even a casual bserver that tampering using slvents t remve inks and tners has ccurred. The mst preferred methd f print ing this ink is dry ffset printing r letterpress printing. The chemical reactive ink f this inventin reacts with a variety f slvents plar, nnplar, armatic, aliphatic, halgenated, and xygenated. A hidden message can be printed under the ink s that it is revealed if there is any tampering with the dcument using a slvent. The hidden message can be printed by any typical methd, such as flex graphy, wet r dry lithgraphy, r screen-printing. The mes sage will be hidden best if the message is printed with an ink that has a clr which matches that f the chemical reactive ink. The message can be printed as either a slid r a screen, varying frm a 0% slid t a 1% screen. The chemical reactive ink can be printed in a pattern, Such as Chinese characters r pseudrandm marble patterns, t hide the mes sage effectively. Other security techniques can be used with security dcu ment accrding t the present inventin, prviding cumula tive security prvisins. Fr example, ther arrangements can be added fr detecting the use f slvents. These arrange ments include using paper that has ne r several dyes as dry particles that will spread and create Small stained dts when expsed t slvent. Mre than ne dye is typically used t react with all types f slvents. Certain prir art inks may als be used, althugh they may nt be as effective as desired, since if the frger is patient and washes the dcument with ne r mre slvents ver an extended perid f time, the stains frm Such inks can be cmpletely remved. Anther type f slvent reactive ink is the chemical vid ink. Chemical vid inks react with slvent t g frm clr

8 5 less t clred, and are usually printed as a message such as "VOID. Sme vid inks are reactive with bleach, prducing a clr image when expsed t bleach. Chemical vid inks typically cntain Slid leuc dyes and Slid activatrs. The active cmpnents are nly sluble in plar and xygenated Slvents (e.g. alchls, ketnes, esters) and thus tampering with nn-xygenated slvents is nt revealed. The chemical reactive ink f the present inventin has the advantage ver security paper and Vid inks f the prir art that it reacts with a wide variety f slvents plar, nnplar, aliphatic, armatic, xygenated, and halgenated. When expsed t slvent, the ink clr will disappear and a hidden message can be revealed that cnfirms tampering. As stated abve, prir art chemical Vid inks may nt reveal tampering with a nn-xygenated Slvent, and sme dyes within a secu rity paper can be cmpletely disslved and washed away leaving n evidence f tampering. Sme examples f slvents that effectively remve the clr frm the inventin are: methanl, ethanl, isprpanl, hexyl carbitl. 1-pentanl, acetne, tluene, gasline, isprpylamine, 1-methyl-2-pyr rlidne, mineral spirits, S-limnene, range il, m-xylene, prpylene glycl prpyl ether, heptanes, caprlactne, chl rfrm, diethylene glycl mnbutyl ether, phenyl ether, 3-methyl-2-butanne, 2-butanne, carbn tetrachlride, pr pylene glycl mnmethyl ether acetate, leic acid, dictyl phthalate, 2-ethylhexanic acid, rubbing alchl, and nail plish remver. The chemical reactive ink f the present inventin is cm prised f tw parts. The first part is a slvent sluble dye. Any slvent dye can be incrprated int the inventin. Such dyes can be frm any f the chemical families f slvent dyes, such as az, Xanthene, anthraquinne, triarylmethane, azine, thi azine, phathalcynine, and metal cmplexes f the same. The mst effective slvent dye is sluble in a wide variety f slvents. The preferred dye fr this inventin is frm the anthraquinne family, specifically slvent blue 351,4-bis (butylamine)anthraquinne. Examples f ther dyes that can be used, hwever, are: slvent black 3, slvent black 5, sl vent red 23, slvent red 132, slvent red 8, slvent red 49, slvent red 89, slvent red 122, slvent blue 4, slvent blue 5, slvent blue 35, slvent blue 44, slvent blue 45, slvent blue 59, slvent blue 97, slvent vilet 9, and slvent vilet 8. The present inventin is nt t be cnsidered t be limited t any specific dye, hwever. The cncentratin f dye in the ink can be frm 0.1% t 20%, with the preferred range being 1% t 8%. The secnd part is a nn-drying vehicle r ink base. Althugh a drying vehicle (e.g., based n either an alkyd r linseed il) r UV curable vehicle can be used, such vehicles tend t trap the dye in a crsslinked matrix which reduces the amunt f dye that can be disslved and leached ut by the slvent. The preferred base cnsists f a blend f tw r mre f tall il butyl ester, mdified phenlic resin, silica, and calcium Stearate. This base prvides gd printing qualities, Slvency f the dye, and is nn-drying. Other types and cm binatins f resins, ils, and mdifiers may be equally effec tive. The level f resin can be frm % t 60% f the nn-drying vehicle r ink base by weight, with the preferred range being 32% t 45%. The il level can be frm 30% t 90% f the nn-drying vehicle r ink base by weight, with the preferred range being 40% t 65%. Silica can be incrprated at 0% t 15% f the nn-drying vehicle r ink base by weight, with the preferred level being 6% t 9%. The calcium stearate can be added at 0% t 6% f the nn-drying vehicle r ink base by weight, with the preferred level being 1% t 3%. When the ink has nly the slvent dye as the clrant, the ink will g frm clred t clrless when expsed t slvent A third cmpnent can be added t give a clr change. The cmpnent can be anther slvent dye that is sluble in a limited grup f slvents, and thus it culd be disslved ut f the ink with the blue r remain n the paper depending n the Slvent. The cmpnent can als be a pigment that cannt be disslved by slvents. A prtin f the pigment can be washed away by a slvent that slubilizes the ink base while a prtin f the pigment remains in the paper fibers, giving a visible tint t the printed area. If a hidden message is printed under this ink, the ink is selected Such that the message is visible thrugh the pigment clr. An ptinal additin t the ink f the present inventin is a bleach reactive chemical t reveal evidence f expsure t bleach. One such chemical is Chlrstain OR (a guanidine derivative) frm Bayer Crp. Anther variatin f the inventin is using a dye dispersin mixed int a flexgraphic ink base. The slvent dye is grund t a small particle size t act as a pigment in the water-based ink. Hwever, the dye can still be disslved and remved by a slvent. This allws printing by flexgraphic methds. Examples f frmulatins include the fllwing, where Frmula 1 is the preferred frmulatin. Frmula 1 SPR Resin 41.70% Sylfat % Aersil R % Calcium Stearate 1.35% Slvent Blue 35 Dye S.00% SPR Resin is available frm AkzNbel Resins, Wd stck, Cnn. This is a maleated phenlic mdified resin. Sylfat 9012 is available frm Arizna Chemical, Panama City, Fla. This is a tall il fatty acid butyl ester. Aersil R972 is available frm Degussa Crp., Ridgefield Park, N.J. This is a hydrphbic fumed silica. Calcium stearate is available frm Witc Crp. Slvent Blue G (Slvent Blue 35) is available frm Aakash Chemical, Glendale Heights, Ill. Frmula 2 SPR Resin 41.70% Sylfat % Aersil R % Calcium Stearate 1.35% Chlrstain RR S.00% Chlrstain RR is available frm Bayer Crp., Pittsburg, Pa. This is Slvent Blue 97. Chlrstain RR had lwer slubility ver the range f slvents as cmpared t Slvent Blue G. Khl and Madden Sy Laser PMS 293 Blue Ink Aakash Black BN Dye (Slvent Black 3) Frmula 3 90% available frm Khl & Madden, Nrthlake, IL % Here, a slvent dye was incrprated int a cnventinal drying ink. The dye culd be disslved ut f the ink imme

9 7 diately after printing but the amunt f ink that culd be remved after 24 hurs was reduced due t xidatin f the ink vehicle. Frmula 4 Khl and Madden UWWarm Red FLMDV Chlrstain Blue RR 90% % After curing, the amunt f dye that culd be remved was greatly reduced. Turning t the drawings, it will be seen that the chemically reactive ink can be printed ver a hidden warning message virtually anywhere n the security dcument. It is particularly advantageus t use Suchink and hidden warning messages in thse areas f the dcument that are mst likely t be the subject f attempted alteratin. FIGS. 1 and 2 illustrate a number f areas in which the masking ink may be applied t a security dcument, and cmmn reference numerals are used in these tw drawings t refer t crrespnding ele ments. The security dcument f FIG. 1 has a dcument substrate 12 which typically will be a paper r similar mate rial. Typically, a message is printed n the Substrate, and then a slvent sluble masking ink accrding t the present inven tin is printed ver the message. When the masking ink is remved as a result f the applicatin f slvent, the message becmes visible. The message may be a warning message that nly becmes visible after a slvent is applied t said masking ink. The message is printed n the substrate adjacent ne r mre infrmatin areas n the security dcument, as shwn in FIG. 1. The slvent sluble masking ink may be applied ver the message n the check. These areas include at least ne f a written amunt area 14, a numerical amunt area 16, a payee area 18, a MICR accunt and ruting number area 20 and the signature area 22. The chemical sensitive ink may be printed near ne r mre f these areas in a variety f patterns t reveal tampering with slvent. FIG.3 shws an example f the masking ink being applied ver a hidden message. The masking ink essentially bscures the VOID wrd frm view. As shwn in FIG. 4, hwever, when the masking ink is remved as a result f the applicatin f Slvent, a warning message is revealed which will give ntice t even a casual bserver that the dcument has been Vided by alteratin. The message may be printed in a pan tgraph pattern, as shwn in FIG.4, and then verprinted with the masking ink, als in a pantgraph pattern, as shwn in FIG. 3. Alternatively, the message may be printed in a pale ink as shwn in FIG. 6, and then verprinted with the masking ink in a pantgraph pattern, as shwn in FIG. 5. The warning mes sage in this case is smewhat mre lengthy. The masking ink essentially bscures the warning frm view, as shwn in FIG. 5. As illustrated in FIG. 6, hwever, when the masking ink is remved as a result f the applicatin f slvent, a warning message is revealed which will give ntice t even a casual bserver that the dcument has been vided by alteratin. It will be appreciated that the hidden message may be printed n the substrate in any f the areas 14, 16, 18, 20. and 22 that carry handwritten infrmatin, rather than adja cent these areas. This has the advantage f making it difficult t apply a slvent t the handwritten infrmatin withut activating the masking ink. Hwever, it has the disadvantage that the message culd be partially bscured by the handwrit ten infrmatin. As a further alternative, the message may be printed arund the periphery f ne r mre infrmatin areas 14, 16, 18, 20, and 22 n the security dcument, as shwn in FIG 2. FIGS. 1 and 2 shw the applicatin f the warning message t the frnt face 24 f the security dcument, such as a bank check. FIG. 8 shws the applicatin f the warning message t the rear face f the bank check in an endrsement area 26. FIG. 8 further illustrates the use f laid lines 28 which will make alteratin f the bank check mre difficult, especially if alteratin by cutting and pasting the check is attempted. FIG. 7 illustrates the use f the masked warning message in cnjunctin with ther security measures. Fr example, the masked warning message in area 30 may be cmbined with a thermchrmic ink authenticatin insignia 32 and a Vid pantgraph backgrund pattern 34. The masked warning message prvides an indicatin if the security dcument is phtcpies, while the thermchrmic ink authenticatin insignia will change clr when Subjected t heat t facilitate testing t be sure that the dcument is genuine. Other aspects, bjects, and advantages f the present inven tin can be btained frm a study f the drawings, the discl Sure, and the appended claims. What is claimed is: 1. A security dcument incrprating a chemically reactive security ink, cmprising: a dcument Substrate, a message printed n said dcument Substrate in a slvent resistant message ink, and a slvent-sluble masking ink printed in a pattern ver said message s that said pattern bscures r hides said mes Sage until said slvent-sluble masking ink is remved by expsure f said slvent-sluble masking ink t sl Vent, wherein: the slvent-sluble masking ink cmprises a slvent Sluble dye and a nn-drying vehicle r ink base; the slvent-sluble dye is selected frm the grup cnsist ing f az dyes, Xanthene dyes, anthraquinne dyes, triarylmethane dyes, azine dyes, thiazine dyes, phthal cyanine dyes, and metal cmplexes f the same; the nn-drying vehicle r ink base cmprises frm % t 60% by weight resin and frm 30% t 90% by weight il, based n the ttal weight f the nn-drying vehicle r ink base; the slvent-sluble masking ink cmprises frm 0.1% t 20% by weight said slvent-sluble dye, based n the ttal weight f the slvent-sluble masking ink. 2. The security dcument f claim 1, in which the message is a warning message. 3. The security dcument f claim 1, in which the message is printed n said dcument Substrate adjacent an area that carries handwritten infrmatin. 4. The security dcument f claim 1, in which the message is printed in a pantgraph pattern, and in which said slvent sluble masking ink is printed in a pantgraph pattern. 5. The security dcument f claim 1 in which said message is printed adjacent ne r mre infrmatin areas n the security dcument. 6. The security dcument f claim 5 in which said message is printed arund the periphery f ne r mre infrmatin areas n the security dcument. 7. The security dcument f claim 1 in which said security dcument is a bank check having a frnt face and a rear face, and in which said message is printed n the frnt face f the bank check adjacent t at least ne f a written amunt area, a numerical amunt area, a payee area, a MICR accunt and ruting number area, and a signature area.

10 8. The security dcument f claim 7 in which said security dcument is a bank check having a frnt face and a rear face, and in which said message is printed n the frnt face f the bank check arund the periphery f at least ne f a written amunt area, a numerical amunt area, a payee area, a MICR accunt and ruting number area, and a signature area. 9. The security dcument f claim 1 in which said security dcument is a bank check having a frnt face and a rear face, and in which said message is printed n the frnt face f the bank check in at least ne f a written amunt area, a numeri cal amunt area, a payee area, a MICR accunt and ruting number area, and a signature area.. The security dcument f claim 1 in which said security dcument is a bank check having a frnt face and a rear face, and in which said message is printed n the rear face f the bank check adjacent t an endrsement area. 11. The security dcument f claim 1 in which said security dcument is a bank check having a frnt face and a rear face, and in which said message is printed n the rear face f the bank check in an endrsement area. 12. The security dcument f claim 1 in which said slvent sluble masking ink further cmprises a secnd slvent sluble dye that is sluble in a limited grup f slvents with respect t said first slvent-sluble dye. 13. The security dcument f claim 1 in which said slvent sluble masking ink further cmprises a slvent-insluble pigment. 14. The security dcument f claim 13 in which said sl Vent-insluble pigment has a pigment clr selected Such that said message is visible thrugh said pigment clr when said Slvent-sluble masking ink is expsed t slvent and said first slvent-sluble dye is remved. 15. The security dcument f claim 1 in which said slvent resistant message ink and said slvent-sluble masking ink are the same clr. 16. The security dcument f claim 1 in which said il is a tall il butyl ester. 17. The security dcument f claim 1 in which said resin is a phenlic resin The security dcument f claim 1 in which said il is a tall il butyl ester and said resin is a maleated phenlic resin. 19. The security dcument f claim 1, in which said sl Vent-sluble masking ink further cmprises a mdifier selected frm the grup cnsisting f silica, calcium Stearate, and cmbinatins theref. 20. The security dcument f claim 1 in which: said slvent-sluble masking ink cmprises frm 1% t 8% by weight said slvent-sluble dye, based n the ttal weight f the slvent-sluble masking ink; and said nn-drying vehicle r ink base cmprises frm 32% t 45% by weight said resin and frm 40% t 65% by weight said il, based n the ttal weight f the nn drying vehicle r ink base. 21. The security dcument f claim 20, in which said Slvent-sluble masking ink further cmprises a mdifier selected frm the grup cnsisting f silica, calcium Stearate, and cmbinatins theref. 22. The security dcument f claim 1 in which: said slvent-sluble masking ink cmprises frm 1% t 8% by weight f said slvent-sluble dye, based n the ttal weight f the slvent-sluble masking ink; said resin is a maleated phenlic resin; said il is a tall il butyl ester; and said nn-drying vehicle r ink base cmprises: frm % t 45% by weight said maleated phenlic resin, based n the ttal weight f the nn-drying vehicle r ink base; frm 40% t 65% by weight said tall il butyl ester, based n the ttal weight f the nn-drying vehicle r ink base; frm 6% t 9% by weight silica, based n the ttal weight f the nn-drying vehicle r ink base; and frm 1% t 3% calcium stearate, based n the ttal weight f the nn-drying vehicle r ink base. 23. The security dcument f claim 22, in which said Slvent-sluble dye is an anthraquinne dye. k k k k k