US2313592A - Safety paper and process of preparing the same - Google Patents
Safety paper and process of preparing the same Download PDFInfo
- Publication number
- US2313592A US2313592A US358523A US35852340A US2313592A US 2313592 A US2313592 A US 2313592A US 358523 A US358523 A US 358523A US 35852340 A US35852340 A US 35852340A US 2313592 A US2313592 A US 2313592A
- Authority
- US
- United States
- Prior art keywords
- paper
- safety paper
- benzidine
- safety
- preparing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title description 6
- HFACYLZERDEVSX-UHFFFAOYSA-N benzidine Chemical class C1=CC(N)=CC=C1C1=CC=C(N)C=C1 HFACYLZERDEVSX-UHFFFAOYSA-N 0.000 description 16
- 239000000976 ink Substances 0.000 description 15
- -1 benzidine Chemical class 0.000 description 14
- 150000001875 compounds Chemical class 0.000 description 10
- 150000003839 salts Chemical class 0.000 description 10
- 239000000126 substance Substances 0.000 description 10
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical class Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 7
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 6
- 239000012286 potassium permanganate Substances 0.000 description 6
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 6
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 125000001424 substituent group Chemical group 0.000 description 4
- 150000002989 phenols Chemical class 0.000 description 3
- 239000011800 void material Substances 0.000 description 3
- AZQWKYJCGOJGHM-UHFFFAOYSA-N 1,4-benzoquinone Chemical compound O=C1C=CC(=O)C=C1 AZQWKYJCGOJGHM-UHFFFAOYSA-N 0.000 description 2
- NIQCNGHVCWTJSM-UHFFFAOYSA-N Dimethyl phthalate Chemical compound COC(=O)C1=CC=CC=C1C(=O)OC NIQCNGHVCWTJSM-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 150000004982 aromatic amines Chemical class 0.000 description 2
- 238000004061 bleaching Methods 0.000 description 2
- 238000002845 discoloration Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- DFHGTHZPDMDKTO-UHFFFAOYSA-N 2-amino-5-(4-aminophenyl)cyclohexa-2,4-diene-1,1-disulfonic acid Chemical compound C=1(CC(C(N)=CC1)(S(=O)(=O)O)S(=O)(=O)O)C1=CC=C(N)C=C1 DFHGTHZPDMDKTO-UHFFFAOYSA-N 0.000 description 1
- ZXVONLUNISGICL-UHFFFAOYSA-N 4,6-dinitro-o-cresol Chemical group CC1=CC([N+]([O-])=O)=CC([N+]([O-])=O)=C1O ZXVONLUNISGICL-UHFFFAOYSA-N 0.000 description 1
- OCEINMLGYDSKFW-UHFFFAOYSA-N 4-(4-amino-3-nitrophenyl)-2-nitroaniline Chemical compound C1=C([N+]([O-])=O)C(N)=CC=C1C1=CC=C(N)C([N+]([O-])=O)=C1 OCEINMLGYDSKFW-UHFFFAOYSA-N 0.000 description 1
- LPDSNGAFAJYVKH-UHFFFAOYSA-N 4-(4-aminophenyl)-2,3-dichloroaniline Chemical compound C1=CC(N)=CC=C1C1=CC=C(N)C(Cl)=C1Cl LPDSNGAFAJYVKH-UHFFFAOYSA-N 0.000 description 1
- RQBGCPGMPGMRCF-UHFFFAOYSA-N 4-(4-aminophenyl)-6,6-dibromocyclohexa-1,3-dien-1-amine Chemical compound C1C(Br)(Br)C(N)=CC=C1C1=CC=C(N)C=C1 RQBGCPGMPGMRCF-UHFFFAOYSA-N 0.000 description 1
- LHECBTWFKAHFAS-UHFFFAOYSA-N 4-(4-aminophenyl)-6,6-dichlorocyclohexa-1,3-dien-1-amine Chemical compound C1C(Cl)(Cl)C(N)=CC=C1C1=CC=C(N)C=C1 LHECBTWFKAHFAS-UHFFFAOYSA-N 0.000 description 1
- LAAGZZYZOZJYAS-UHFFFAOYSA-N 4-(4-aminophenyl)-6,6-dichlorocyclohexa-1,3-dien-1-amine;dihydrochloride Chemical compound Cl.Cl.C1C(Cl)(Cl)C(N)=CC=C1C1=CC=C(N)C=C1 LAAGZZYZOZJYAS-UHFFFAOYSA-N 0.000 description 1
- 239000001856 Ethyl cellulose Substances 0.000 description 1
- ZZSNKZQZMQGXPY-UHFFFAOYSA-N Ethyl cellulose Chemical compound CCOCC1OC(OC)C(OCC)C(OCC)C1OC1C(O)C(O)C(OC)C(CO)O1 ZZSNKZQZMQGXPY-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- ZOXJIQNURSAHRV-UHFFFAOYSA-N [4-(4-azaniumylphenyl)phenyl]azanium;sulfate Chemical class [O-]S([O-])(=O)=O.C1=CC([NH3+])=CC=C1C1=CC=C([NH3+])C=C1 ZOXJIQNURSAHRV-UHFFFAOYSA-N 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 239000007900 aqueous suspension Substances 0.000 description 1
- 235000010290 biphenyl Nutrition 0.000 description 1
- 239000004305 biphenyl Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- FBSAITBEAPNWJG-UHFFFAOYSA-N dimethyl phthalate Natural products CC(=O)OC1=CC=CC=C1OC(C)=O FBSAITBEAPNWJG-UHFFFAOYSA-N 0.000 description 1
- 229960001826 dimethylphthalate Drugs 0.000 description 1
- VFNGKCDDZUSWLR-UHFFFAOYSA-L disulfate(2-) Chemical compound [O-]S(=O)(=O)OS([O-])(=O)=O VFNGKCDDZUSWLR-UHFFFAOYSA-L 0.000 description 1
- 230000008029 eradication Effects 0.000 description 1
- 229920001249 ethyl cellulose Polymers 0.000 description 1
- 235000019325 ethyl cellulose Nutrition 0.000 description 1
- 150000003840 hydrochlorides Chemical class 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 229910052920 inorganic sulfate Inorganic materials 0.000 description 1
- 229940099596 manganese sulfate Drugs 0.000 description 1
- 235000007079 manganese sulphate Nutrition 0.000 description 1
- 239000011702 manganese sulphate Substances 0.000 description 1
- SQQMAOCOWKFBNP-UHFFFAOYSA-L manganese(II) sulfate Chemical compound [Mn+2].[O-]S([O-])(=O)=O SQQMAOCOWKFBNP-UHFFFAOYSA-L 0.000 description 1
- 150000002828 nitro derivatives Chemical class 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- ZUOUZKKEUPVFJK-UHFFFAOYSA-N phenylbenzene Natural products C1=CC=CC=C1C1=CC=CC=C1 ZUOUZKKEUPVFJK-UHFFFAOYSA-N 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 239000004289 sodium hydrogen sulphite Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
- D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
- D21H21/44—Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
- D21H21/46—Elements suited for chemical verification or impeding chemical tampering, e.g. by use of eradicators
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S101/00—Printing
- Y10S101/29—Printing involving a color-forming phenomenon
Definitions
- This invention relates to safety paper, and it comprises a safety paper having incorporated therein a 3,3 benzidine derivative reactive with potassium permanganate solutions to form colored compounds which are stable, especially to heat, and which are resistant to reduction by sodium bisulfite. It further comprises safety paper having distinctive marking or indicia printed thereon by inks containng such benzidine derivatives, and it further comprises inks suitable for the prmting of safety paper, which inks contain benzidine derivatives of the character described.
- Safety paper for makin bank checks, drafts, bonds or other documents are composed of a paper base impregnated with chemicals which develop discoloration upon the application of chemical ink eradicators. This impregnation may be throughout the paper or it "may be the result of printing warning indicia, such as the word void," n the paper so that when ink eradicators are applied for the purpose of altering the document the chemicals are converted to colored compounds. If, for example, the word void is printed with a colorless ink, or the printing is camoufiaged when slightly discernible, as shown, for example, in the Smith Patent 1,689,302, then when chemical ink eradicators are applied the word void flashes up in color.
- the class of compounds I use can be generically defined as substantially colorless 3,3 disubstituted benzidines, or salts thereof, which yield 001- ored compounds when treated with potassium permanganate, but which colored compounds are resistant to reduction or bleaching by sodium bisulfite. All of the substances I use are thus benzidines, or benzidine salts, having substituents in the 3,3 positions, further qualified by their chemical behaviour when treated with potassium permanganate followed by sodium bisulfite.
- diphenylbenzidine and salts thereof 3,3 dichlorobenzidine and salts thereof 3,3 dibromobenzidine and salts thereof 3,3 benzidine disulfonic acid and salts thereof 3,3 dinitrobenzidine and salts thereof 3,3 diphenylbenzidine and salts thereof All but the diphenyl compound are benzidines which are disubstituted in the 3,3 positions by negative substituents, and all such negatively substituted benzidines form colored compounds with permanganate which are resistant to removal when treated with sodium bisulfite.
- Salts of thesecompounds are generally the di-. hydrochloride such as 3,3 dichlorobenzidine dihydrochloride since the hydrochlorides are readily water soluble.
- the dinitro compounds are yellow but this is no objection if the paper itself is tinted yellow or, when the nitro compound is used for printing warning indicia the printing is camouflaged as described above. All of these benzidine derivatives develop discernible brownish stains when treated with permanganate and the stain resists attempts to remove it by the application of a sodium bisulfite solution. The stains also resist attempts to remove them by volatilization.
- the disubstituted benzidines of the present invention can be incorporated in the paper in any of the ways well known in the art.
- One of the simplest is to impregnate the paper with an aqueous solution of the disubstituted benzidine in the form of its water-soluble dihydrochloride and then precipitate an insoluble salt by treating the paper with an aqueous solution of an inorganic sulfate. This precipitates the water-insoluble disulfate.
- the insoluble disubstituted benzidine sulfate can be added to the beater in the manufacture of the paper as a suspension. or aqueous suspensions of the insoluble sulfate, such as 3,3 dic mecanicbenzidine sulfate can be used for sizing the paper.
- .Proportions of the substituted benzidine are This is particularly useful where warning words or indicia which develop color upon the application of eradicators are printed.
- One suitable ink contains 2 parts by weight of a 5% solution of ethyl cellulose in dimethylphthalate and 1 part of dichlorobenzidine.
- the ink vehicle used can be varied and is no part of the present invention. The proportions can, of course, be varied over wide limits depending upon the printing conditions and the desired depth of color in the resulting stain.
- benzidine derivatives of the present invention are particularly designed to be responsive to permanganate eradicators and resistant to attempts to remove the colored compounds thus formed, it will, of course, be understood that the substances of my invention are highly responsive to eradicators of the hypochlorite type. Thus I have been able to provide color-forming compounds for use in safety paper which are responsive to common ink eradicators and are resistant to attempts which may be made to remove the colored compounds formed.
- safety paper in the appended claims means any paper or writing surface on which it is desired to indicate the application of a chemical ink eradicator by the production of a stain or discoloration.
- a. safety paper which comprises incorporating in the paper a benzidine compound chosen from the group consisting of substituted benzidines, having negative substituents in the 3,3 positions, and salts thereof.
- An ink comprising a vehicle and a benzidine compound chosen from the group consisting of substituted benzidines, having negative sub- BURGESS W. SMITH.
Landscapes
- Inks, Pencil-Leads, Or Crayons (AREA)
- Paper (AREA)
Description
Patented Mar. 9, 1943 SAFETY PAPER AND PROCESS OF PREPARING THE SAME Burgess W. Smith, Rochester, N. 1%, assignor to The Todd Company, Inc., Rochester, N. Y., a corporation of New Yorlr No Drawing. Application September 26, 1940, Serial No. 358,523
12 Claims.
This invention relates to safety paper, and it comprises a safety paper having incorporated therein a 3,3 benzidine derivative reactive with potassium permanganate solutions to form colored compounds which are stable, especially to heat, and which are resistant to reduction by sodium bisulfite. It further comprises safety paper having distinctive marking or indicia printed thereon by inks containng such benzidine derivatives, and it further comprises inks suitable for the prmting of safety paper, which inks contain benzidine derivatives of the character described.
Safety paper for makin bank checks, drafts, bonds or other documents are composed of a paper base impregnated with chemicals which develop discoloration upon the application of chemical ink eradicators. This impregnation may be throughout the paper or it "may be the result of printing warning indicia, such as the word void," n the paper so that when ink eradicators are applied for the purpose of altering the document the chemicals are converted to colored compounds. If, for example, the word void is printed with a colorless ink, or the printing is camoufiaged when slightly discernible, as shown, for example, in the Smith Patent 1,689,302, then when chemical ink eradicators are applied the word void flashes up in color.
Various color-forming compounds have been used in the past for preparation of safety paper of this type, and the impregnating chemicals have generally been adequate for the development of a permanent color with solutions of hypochlorites preceded or followed by the action of an organic acid, such as tartaric. Safety papers which contain aromatic amines, such as benzidine, and phenol compounds, such as diphenols, together with manganese sulfate, produce more or less permanent stains with eradicators of the hypochlorite type. Potassium permanganate will also form a colored oxidation product with amines and phenols but this colored oxidation product can be bleached .with reducing agents, such as sodium bisulphite. Moreover, many of the colored oxidation products obtained by means of potassium permanganate will sublime when heated moderately, because of their quinone character, and they can be driven off from the paper by warming the paper below the charring temperature thereof.
Thus the usual aromatic amines and phenolic compounds are satisfactory when hypochlorite ink eradicators are used, but are unsatisfactory when ink eradicators of the permanganate type are used. Since potassium permanganate is cheap and readily available it is sometimes used for the purpose of altering documents, and if the safety paper used for these documents is not resistent to the bleaching or volatilization of the colored permanganate oxidation product then, of course, the paper is limited in its protection.
I have now discovered a class of organic compounds which can be incorporated in safety paper, or in inks for the printing of warning indicia thereon, and which overcome common objections hitherto encountered with respect to eradication by permanganates.
The class of compounds I use can be generically defined as substantially colorless 3,3 disubstituted benzidines, or salts thereof, which yield 001- ored compounds when treated with potassium permanganate, but which colored compounds are resistant to reduction or bleaching by sodium bisulfite. All of the substances I use are thus benzidines, or benzidine salts, having substituents in the 3,3 positions, further qualified by their chemical behaviour when treated with potassium permanganate followed by sodium bisulfite.
Among the substances which can be used in the practice of the present invention are:
3,3 dichlorobenzidine and salts thereof 3,3 dibromobenzidine and salts thereof 3,3 benzidine disulfonic acid and salts thereof 3,3 dinitrobenzidine and salts thereof 3,3 diphenylbenzidine and salts thereof All but the diphenyl compound are benzidines which are disubstituted in the 3,3 positions by negative substituents, and all such negatively substituted benzidines form colored compounds with permanganate which are resistant to removal when treated with sodium bisulfite.
Salts of thesecompounds are generally the di-. hydrochloride such as 3,3 dichlorobenzidine dihydrochloride since the hydrochlorides are readily water soluble. The dinitro compounds are yellow but this is no objection if the paper itself is tinted yellow or, when the nitro compound is used for printing warning indicia the printing is camouflaged as described above. All of these benzidine derivatives develop discernible brownish stains when treated with permanganate and the stain resists attempts to remove it by the application of a sodium bisulfite solution. The stains also resist attempts to remove them by volatilization.
The disubstituted benzidines of the present invention can be incorporated in the paper in any of the ways well known in the art. One of the simplest is to impregnate the paper with an aqueous solution of the disubstituted benzidine in the form of its water-soluble dihydrochloride and then precipitate an insoluble salt by treating the paper with an aqueous solution of an inorganic sulfate. This precipitates the water-insoluble disulfate. Alternatively, the insoluble disubstituted benzidine sulfate can be added to the beater in the manufacture of the paper as a suspension. or aqueous suspensions of the insoluble sulfate, such as 3,3 diciilorbenzidine sulfate can be used for sizing the paper.
.Proportions of the substituted benzidine are This is particularly useful where warning words or indicia which develop color upon the application of eradicators are printed. One suitable ink contains 2 parts by weight of a 5% solution of ethyl cellulose in dimethylphthalate and 1 part of dichlorobenzidine. The ink vehicle used can be varied and is no part of the present invention. The proportions can, of course, be varied over wide limits depending upon the printing conditions and the desired depth of color in the resulting stain.
While the benzidine derivatives of the present invention are particularly designed to be responsive to permanganate eradicators and resistant to attempts to remove the colored compounds thus formed, it will, of course, be understood that the substances of my invention are highly responsive to eradicators of the hypochlorite type. Thus I have been able to provide color-forming compounds for use in safety paper which are responsive to common ink eradicators and are resistant to attempts which may be made to remove the colored compounds formed.
The term safety paper" in the appended claims means any paper or writing surface on which it is desired to indicate the application of a chemical ink eradicator by the production of a stain or discoloration.
Having thus described my invention, what I claim is:
1. Safety paper containing a benzidine compound chosen from the group consisting of substituted benzidines having negative substituents in the 3,3 positions, and salts thereof.
2. Safety paper containing a 3,3 dihalo benzidine compound.
3. Safety paper containing a 3,3 dichlorobenzidine compound.
4. Safety paper containing a 3,3 diphenyl benzidine compound;
5. The process of preparing a. safety paper which comprises incorporating in the paper a benzidine compound chosen from the group consisting of substituted benzidines, having negative substituents in the 3,3 positions, and salts thereof.
6. The process of preparing a safety paper which comprises incorporating in the paper a 3,3 dihalo benzidine compound.
'7. The process of preparing safety paper which comprises incorporating therein a 3,3 dichlorbenzidine compound.
8. The process of preparing safety paper which comprises incorporating therein a 3,3 diphenyl benzidine compound.
9. An ink comprising a vehicle and a benzidine compound chosen from the group consisting of substituted benzidines, having negative sub- BURGESS W. SMITH.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US358523A US2313592A (en) | 1940-09-26 | 1940-09-26 | Safety paper and process of preparing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US358523A US2313592A (en) | 1940-09-26 | 1940-09-26 | Safety paper and process of preparing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2313592A true US2313592A (en) | 1943-03-09 |
Family
ID=23410002
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US358523A Expired - Lifetime US2313592A (en) | 1940-09-26 | 1940-09-26 | Safety paper and process of preparing the same |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2313592A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2555474A (en) * | 1948-06-04 | 1951-06-05 | Vries John De | Safety ink |
| US3886083A (en) * | 1974-05-09 | 1975-05-27 | American Bank Note Co | Safety inks and documents |
-
1940
- 1940-09-26 US US358523A patent/US2313592A/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2555474A (en) * | 1948-06-04 | 1951-06-05 | Vries John De | Safety ink |
| US3886083A (en) * | 1974-05-09 | 1975-05-27 | American Bank Note Co | Safety inks and documents |
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