US2333979A - Safety paper - Google Patents

Safety paper Download PDF

Info

Publication number
US2333979A
US2333979A US407011A US40701141A US2333979A US 2333979 A US2333979 A US 2333979A US 407011 A US407011 A US 407011A US 40701141 A US40701141 A US 40701141A US 2333979 A US2333979 A US 2333979A
Authority
US
United States
Prior art keywords
coating
paper
ink
benzidine
base
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
Application number
US407011A
Inventor
Rexford H Bradt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fox River Paper Corp
Original Assignee
Fox River Paper Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Fox River Paper Corp filed Critical Fox River Paper Corp
Priority to US407011A priority Critical patent/US2333979A/en
Application granted granted Critical
Publication of US2333979A publication Critical patent/US2333979A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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
    • 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
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/914—Transfer or decalcomania
    • Y10S428/915—Fraud or tamper detecting
    • 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
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/916—Fraud or tamper detecting
    • 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
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24802—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
    • Y10T428/24835—Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] including developable image or soluble portion in coating or impregnation [e.g., safety paper, etc.]

Definitions

  • the invention relates to an improved process for the manufacture of safety paper usable for documents, bonds, checks, notes, and the like, and to the safety paper produced by said process.
  • One purpose is the provision of a safety paper in which any erasure becomes immediately apparent by the revelation of an underlying layer of a different color than the surface layer of the paper.
  • Another purpose is the provision of a paper, which may be absorbent or not, but which has a relatively absorbent coating of a different color whereby the ink which is applied to the coating penetrates entirely through the coating and also to or into the base paper, whereby a removal of the coating is not sufiicient to remove the ink.
  • Another purpose is the provision of a safety paper having a coating sensitive to ink removers whereby a staining of the coating results when an ink remover is applied thereto.
  • Another purpose is the provision of a relatively absorptive coating impregnated with or including a chemical or chemicals responsive to an ink eradicator whereby, when an ink eradicator is applied, the coating takes up a large amount of the eradicator, thus assuring the production of a deep stain.
  • the method of formation of the paper is as follows: An ordinary base paper, such as a bond or ledger paper, is employed, and this base paper may, if desired, be somewhat ink absorptive. Ink which is applied to the coating and passes through the coating will penetrate to or into the base paper. A relatively absorbent coating of a different color than the base paper is applied to the paper.
  • a wide variety of coatings may be employed, but it is important that whatever coating is used be relatively ink absorbent, preferably sufficiently absorbent so that the amount of ink normally used, and the amount of pressure normally applied in writing or typing on the paper, will be sufficient to cause some of the ink to pass, under normal circumstances, entirely through the coating and to or into the base paper, whereby a mere erasure of the coating will not be enough to eliminate the ink.
  • a colored coating may be used, or a colored paper, or coating and paper of different colors.
  • Any such coating may include a relatively porous filler, and any suitable binder, so that the coating, when it dries, will be ink absorptive, and
  • a diiferential coloring of the absorbent coating and the absorbent base makes the erasure of the ink impossible without detection, because of the change in color produced by the removal of the coating, it is also found important to protect the coating against ink eradicators.
  • Any suitable chemical or chemicals which react by a color change to the presence of or the application of ink eradicators may, therefore, be applied to or included in the coating. While a wide variety of such chemicals may be employed, the employment of benzidine is taken as an example, or a chemical or chemicals of the benzidine group.
  • benzidine in connection with the coating, it is found desirable to cut the benzidine with a suitable acid and to make it into a colloidal paste, for example in a ball mill.
  • phosphoric acid in a chemical equivalent proportion, gives a paste that is free from any tendency to body or jell the coating mixture.
  • the benzidine combines chemically with the phosphoric acid.
  • the following may be employed:
  • the ratio of filler, especially the calcium carbonate, to the casein controls the absorptiveness of the coating.
  • the casein is the binder that holds the coating to the surface of the sheet. Enough casein must be used to keep the coating from dusting ofi.
  • the above given ratio of filler and casein produces a coating which will not dust off, but provides a surface which can readily be written upon by pen and ink, but is absorbent enough to take up an appreciable quantity of the ink.
  • the benzidine phosphate responds to the usual ink removers which contain a chlorine oxidizing agent.
  • the calcium carbonate in the coating reacts with any acid which may be used alone or in conjunction with the ink remover. It will be'understood, of course, that, whereas a, practical set of proportions is illustrated, substantial variations from the proportions above given may be employed without departing from the present invention.
  • the coating including the suitable chemical, such as the benzidine phosphate paste, may be applied to the base paper in any suitable manner.
  • the base paper may for example be passed through a bath or body of the coating in liquid form; the coating may thereafter be doctored in any suitable manner, and the coated paper dried.
  • H V A coating preferably sufiiciently ink ab-v sorptive so that the ink penetrates entirely through the coating and to or into the.ba-se paper.
  • a safety paper including a base adapted to receive and retain ink, a coating of a color differentiated from that of the and suificiently ink absorptive to permit ink supplied to the sur-, face of said coating to penetratereadily to the surface of the base, said coating firmly adhering to the base and not normally separable therefrom andhaving a mineral filler including clay and calcium carbonate and a binder. and a color changing agent of the benzidine group chemically neutralized with phosphoric acid.

Description

Patented Nov. 9, 1943 IUNITED STATES PATENT OFFICE SAFETY PAPER Y Rexford H. Bradt, Battle Creek, Mich, assignor to Fox River Paper Corporation, Appleton, Wis., a corporation of Wisconsin N Drawing.
The invention relates to an improved process for the manufacture of safety paper usable for documents, bonds, checks, notes, and the like, and to the safety paper produced by said process.
One purpose is the provision of a safety paper in which any erasure becomes immediately apparent by the revelation of an underlying layer of a different color than the surface layer of the paper.
Another purpose is the provision of a paper, which may be absorbent or not, but which has a relatively absorbent coating of a different color whereby the ink which is applied to the coating penetrates entirely through the coating and also to or into the base paper, whereby a removal of the coating is not sufiicient to remove the ink.
Another purpose is the provision of a safety paper having a coating sensitive to ink removers whereby a staining of the coating results when an ink remover is applied thereto.
Another purpose is the provision of a relatively absorptive coating impregnated with or including a chemical or chemicals responsive to an ink eradicator whereby, when an ink eradicator is applied, the coating takes up a large amount of the eradicator, thus assuring the production of a deep stain.
Other purposes will appear from time to time in the course of the specification and claim.
The method of formation of the paper is as follows: An ordinary base paper, such as a bond or ledger paper, is employed, and this base paper may, if desired, be somewhat ink absorptive. Ink which is applied to the coating and passes through the coating will penetrate to or into the base paper. A relatively absorbent coating of a different color than the base paper is applied to the paper.
A wide variety of coatings may be employed, but it is important that whatever coating is used be relatively ink absorbent, preferably sufficiently absorbent so that the amount of ink normally used, and the amount of pressure normally applied in writing or typing on the paper, will be sufficient to cause some of the ink to pass, under normal circumstances, entirely through the coating and to or into the base paper, whereby a mere erasure of the coating will not be enough to eliminate the ink. A colored coating may be used, or a colored paper, or coating and paper of different colors.
Any such coating may include a relatively porous filler, and any suitable binder, so that the coating, when it dries, will be ink absorptive, and
Application August 15;, 1941, Serial No. 407,011
1 Claim. (c1. 1 17 -1) will adhere firmly to the base paper, and not dust off. 7
Whereas a diiferential coloring of the absorbent coating and the absorbent base makes the erasure of the ink impossible without detection, because of the change in color produced by the removal of the coating, it is also found important to protect the coating against ink eradicators. Any suitable chemical or chemicals which react by a color change to the presence of or the application of ink eradicators may, therefore, be applied to or included in the coating. While a wide variety of such chemicals may be employed, the employment of benzidine is taken as an example, or a chemical or chemicals of the benzidine group. In employing benzidine in connection with the coating, it is found desirable to cut the benzidine with a suitable acid and to make it into a colloidal paste, for example in a ball mill. As an example of such an acid, phosphoric acid, in a chemical equivalent proportion, gives a paste that is free from any tendency to body or jell the coating mixture. The benzidine combines chemically with the phosphoric acid.
As a specific example of the coating composition, the following may be employed:
The ratio of filler, especially the calcium carbonate, to the casein controls the absorptiveness of the coating. The casein is the binder that holds the coating to the surface of the sheet. Enough casein must be used to keep the coating from dusting ofi. The above given ratio of filler and casein produces a coating which will not dust off, but provides a surface which can readily be written upon by pen and ink, but is absorbent enough to take up an appreciable quantity of the ink.
The benzidine phosphate responds to the usual ink removers which contain a chlorine oxidizing agent. The calcium carbonate in the coating reacts with any acid which may be used alone or in conjunction with the ink remover. It will be'understood, of course, that, whereas a, practical set of proportions is illustrated, substantial variations from the proportions above given may be employed without departing from the present invention.
The coating, including the suitable chemical, such as the benzidine phosphate paste, may be applied to the base paper in any suitable manner. The base paper may for example be passed through a bath or body of the coating in liquid form; the coating may thereafter be doctored in any suitable manner, and the coated paper dried.
The end product is a safety paper which has the following elements and characteristics:
(a) An ordinary base paper, which, if desired, may be somewhat ink absorptive.
(b) A coating which adheres firmlyto *the surface of the base paper sheet.
(c) A differentiation in color between the coating and the base paper. H V (d) A coating preferably sufiiciently ink ab-v sorptive so that the ink penetrates entirely through the coating and to or into the.ba-se paper.
(6 A coating including a chemical or chemicals, such as benzidine phosphate, which stains 'ing.
when an ink eradicator is applied, the depth of the stain being intensified by the liquid absorptive characteristic of the coating. 7 g V It will he realized that various changes may be made in the details or steps-of the ethod of manufacturing the paper, in the pro rtions used, and in the characteristics of the paper itself. It is possible, for example, to apply benzidine phosphate, or some other suitable chemical to the base paper itself, in addition to or in place of the benzidine phosphate in the coat- It will be realized, therefore, that the disclosure herein may be taken as in a broad sense illustrative, instead of a limitation to the precise characteristics of the paper and the precise sequence of .steps herein described.
What is claimed is:
A safety paper including a base adapted to receive and retain ink, a coating of a color differentiated from that of the and suificiently ink absorptive to permit ink supplied to the sur-, face of said coating to penetratereadily to the surface of the base, said coating firmly adhering to the base and not normally separable therefrom andhaving a mineral filler including clay and calcium carbonate and a binder. and a color changing agent of the benzidine group chemically neutralized with phosphoric acid.
REXFORD H. BRADT.
US407011A 1941-08-15 1941-08-15 Safety paper Expired - Lifetime US2333979A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US407011A US2333979A (en) 1941-08-15 1941-08-15 Safety paper

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US407011A US2333979A (en) 1941-08-15 1941-08-15 Safety paper

Publications (1)

Publication Number Publication Date
US2333979A true US2333979A (en) 1943-11-09

Family

ID=23610241

Family Applications (1)

Application Number Title Priority Date Filing Date
US407011A Expired - Lifetime US2333979A (en) 1941-08-15 1941-08-15 Safety paper

Country Status (1)

Country Link
US (1) US2333979A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001430A1 (en) * 1979-11-21 1981-05-28 Wiggins Teape Group Ltd Method of preventing erasure of an image and a booklet of security papers
EP0156463A1 (en) * 1984-02-07 1985-10-02 Unisys Corporation Protection of legal documents by reverse penetration
US4614367A (en) * 1982-06-17 1986-09-30 Rand Mcnally & Co. Tamper-resisting multipart negotiable instruments
US4725497A (en) * 1985-01-21 1988-02-16 Societe Anonyme: Aussedat-Rey Unfalsifiable safety paper
FR2644803A1 (en) * 1989-03-22 1990-09-28 Arjomari Prioux NEW SUPPORT WITH TRANSPARENT COUPLING FOR SAFETY DOCUMENT
US6783991B1 (en) 2002-02-06 2004-08-31 The Standard Register Company Reversible and reusable authentication system for secure documents

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001430A1 (en) * 1979-11-21 1981-05-28 Wiggins Teape Group Ltd Method of preventing erasure of an image and a booklet of security papers
EP0029714A1 (en) * 1979-11-21 1981-06-03 The Wiggins Teape Group Limited Method of preventing erasure of an image and a booklet of security papers
US4614367A (en) * 1982-06-17 1986-09-30 Rand Mcnally & Co. Tamper-resisting multipart negotiable instruments
EP0156463A1 (en) * 1984-02-07 1985-10-02 Unisys Corporation Protection of legal documents by reverse penetration
US4725497A (en) * 1985-01-21 1988-02-16 Societe Anonyme: Aussedat-Rey Unfalsifiable safety paper
FR2644803A1 (en) * 1989-03-22 1990-09-28 Arjomari Prioux NEW SUPPORT WITH TRANSPARENT COUPLING FOR SAFETY DOCUMENT
EP0390638A1 (en) * 1989-03-22 1990-10-03 Arjo Wiggins S.A. Base-sheet for security document, with a transparent coating
US6783991B1 (en) 2002-02-06 2004-08-31 The Standard Register Company Reversible and reusable authentication system for secure documents

Similar Documents

Publication Publication Date Title
US2589306A (en) Bleachable transfer ink
US2083372A (en) Sympathetic ink
US2772184A (en) Paper coating
CA2055745C (en) Process for reducing the water vapour permeability of paper
US3870435A (en) Visual recording method and means
US2333979A (en) Safety paper
US2954302A (en) Water repellent paper and sheathing board
US2445586A (en) Moisture-sensitive paper and the manufacture thereof
JPS57157786A (en) Recording paper for ink jet printer
US2819184A (en) Production of cast surfaced coated paper
US3532534A (en) Method of making a waterproof polyvinyl alcohol coated paper
US2419206A (en) Control of gloss in printing
US2316120A (en) Decalcomania paper
US2931752A (en) Transfer medium and method of making
US3711321A (en) Rapid drying polyvinyl alcohol color coating process
US2637665A (en) Impregnated paper and method of making same
US4393103A (en) Erasable dense paper and improved method of manufacturing
US2364505A (en) Method of making coated paper
US1994750A (en) Typewriter paper of deferred indelibility and method of preparing the same
GB852131A (en) Improvements in or relating to manifolding papers
US1652042A (en) Safety paper
US2553154A (en) Method of waterproofing and flameproofing paper
US3079271A (en) Pressure sensitive sheet record material and method of making
US1983650A (en) Adhesive
US1954805A (en) Method of making adhesives in the form of sheets or the like