US2299693A - Coating for paper - Google Patents

Description

' Oct. 20, 1942. GREEN 2,299,693

COATING FOR PAPER Filed Feb. 25, 194 0 Barrett K. Green Inventor His Attorney Patented Oct. 20, 1942 COATING FOR PAPER Barrett K. Green,

National Cash Register Company, Ohio, a corporation of Maryla awi Dayton, Ohio, assignor to The Dayton,

Application February 23, 1940, Serial No. 320,385

19 Claims.

This invention relates to paper that is sensitizcd to produce visible markings on its surface in response to impact or pressure.

The invention more particularly relates to an impact-sensitive emulsion coating for paper, to be dried thereon, the dried coating having profusely dispersed at random therein minute liquidcontaining cells of two types, which two types of liquid are kept chemically insulated one from the other until the coating is ruptured in selected areas by impact or pressure, whereupon the liquid contents of the two types of cells are caused to contact and chemically unite with one another to form a localized stained area. The individual cells are so small and the effect of the rupturing of the coating is so localized that the mark left on such sensitized paper by being struck by type, for instance, appears to the eye as ordinary printing, the individual contents of the ruptured cells causing a mosaic effect.

Therefore, it is the principal object of this invention to provide a sensitized paper that will generate a visible mark where struck.

Another object of the invention is to provide a coating for paper which, when applied, sensitizes the paper to impact or pressure to produce a local visible mark.

Another object of the invention is to provide a coating for paper which is a mixture of two emulsions having the same continuous phase but different discontinuous phases, which discontinuous phases are chemically active with one another on contact, but which are normally chemically insulated one from the other by the continuous phase.

Another object of the invention is to provide paper having a coating consisting of a plurality of types of liquid cells profusely dispersed in a plasticized solid, which solid is rupturable by impact to produce, at the place of rupture, a visible stain caused by chemical combination of the liquids from difierent cell types.

Another object of the invention is to produce a solid film containing a profuse number of discrete liquid cells, invisible to the unaided eye, that are rupturable by an impact to produce, by means of the released liquids, a local visually integrated area.

Another object of the invention is to provide an emulsion having the same continuous phase and a plurality of discontinuous phases, the continuous phase of which may be dried into a tough transparent film having dispersed therein liquid cells formed from the discontinuous phases of the emulsion.

With these and incidental objects in view. the invention includes certain novel features of construction and combinations of parts, the es sential elements of which are set forth in appended claims and a preferred form or embodiment of which is hereinafter described with reference to the drawing which accompanies and forms a part of this specification.

The drawing is a diagrammatic cross-section through a coated piece of paper showing the dried coating thereon, and showing a typical rupture thereof.

GENERAL DESCRIPTION In preparing the coating, two emulsions are made, the continuous phase of each emulsion being the same solution of a solid and a liquid drying agent. The dispersed phase of each emulsion is selected so as to be chemically reactive on contact with the dispersed phase of the other emulsion to produce a stain. The emulsions so prepared are then applied to the paper either by mixing them together and applying the mixture or by applying one emulsion followed by the other after a short drying period. The common continuous phase of the emulsion is selected so that it chemically insulates the interspersed chemically active discontinuous phases of the mixture of emulsions against reaction during normal handling while the mixture is in the liquid state. If the emulsions are applied separately, the second emulsion combines with the first-applied emulsion to a depth determined by the time the first emulsion is allowed to dry, as the common continuous phase of the emulsions allows the second-applied emulsion to penetrate the partially-dried first coat.

The common continuous phase of the emulsions is preferably colorless and transparent, as are the two types of liquids dispersed in the continuous phase, as it is desirable to have the backgrond color of the paper show through. However, it is within the scope of this invention to have the continuous phase or either of the discontinuous phases of the emulsion of some characteristic color to contrast with the color produced by the impact or pressure.

As the coating produced must be flexible and indifferent to ordinary changes in temperature and humidity, plasticizers and hygroscopic control substances may be included in the coating.

A protective coating of wax, gum, or other inert film may be placed over the emulsion coating as a protection against damage by friction, pressure, or special atmospheric conditions.

EMULSION #1 Continuous phase Grams 1:1 solution of gum dammar in toluene 100 Di-( para tert-butylphenyl) mono-phenyl phosphate (C26H3104P), as a plasticizer 8.5

Discontinuous phase Grams Glycerine 33 Ferric ammonium sulphate 3.2 Water 14 EMULSION #2 Continuous phase Same as the continuous phase of Emulsion #1.

Discontinuous phase Glycerine grams 33 Gallic acid d 6.4 Water do 14 The approximate analysis of the dried coating produced by mixing the above two emulsions and applying the mixture to the paper is:

Continuous solid phase Percent Gum dammar 52.0 Di-(para tert-butylphenyl) mono-phenyl phosphate 8.9

Discontinuous or dispersed phase Percent Glycerine 33.8

Ferric ammonium sulphate 1.7

Gallic acid; 3.6

The emulsions are so made as to cause the dispersed cells to be of a size under 1 millimeter in diameter, which result may be obtained by the use of a screen of 325 mesh to the inch. The dispersed cells of such minute size produce, when a great number of them are ruptured, stains that appear continuous to the eye even though the stain is composed of a great number of smaller stain areas.

The coating may be applied so as to leave the dispersed cells only one deep or several deep over the surface of the paper, depending on the type of impact or pressure which the paper is to receive, or on the results desired. It is obvious that, by use of a different selection of stain-producing chemicals in the dispersed phases of the coating, almost any color of stain can be produced.

Various plasticizers such as castor oil, tri-butyl phosphate, or butyl stearate may be used in appropriate quantities in place of the di-( para tertbutylphenyl) mono-phenyl phosphate.

The plasticized solids used as the continuous phase of the coating may be selected for the characteristics of flexibility desired without departing from the spirit of the invention.

Referring to the drawing, the dispersed liquid cells of Emulsion #1 and the dispersed liquid cells 2| of Emulsion #2 are shown imbe-dded at random in the solid continuous phase 23 of the coating 24. When the coating is ruptured internally by the bursting of the cells, as at point 22, the cells 20 and 2| have their contents combined, as at 25, producing a staining compound which contrasts with the color of the paper 26. In the case of the two formulas given, the compound resulting from the reaction of the gallic acid and the ferric ammonium sulphate is of a blue-black color changing to a black color.

The scope of the invention is not deemed to be limited to a coating of the particular substances contained in the emulsion given as an example, but is deemed to cover any rupturable coating containing dispersed inclusions of heterogeneous liquids having a local stain-producing action when caused to contact by rupture of the continuous phase of the coating.

While the form of invention herein shown and described is admirably adapted to fulfill the objects primarily stated, it is to be understood that it is not intended to confine the invention to the form or embodiment herein disclosed, for it is susceptible of embodiment in various forms all coming within the scope of the claims which follow.

What is claimed is:

1. A liquid emulsion having a continuous phase which is a solution of a solid in a drying liquid, and having a plurality of chemically reactive discontinuous phases, said continuous phase upon drying becoming a rupturable solid continuous phase having dispersed therein heterogeneous liquid inclusions formed from the said discontinuuous phases and said liquid inclusions being reactive to form a stain when allowed to mix upon the rupture of the solid phase.

2. An emulsion having a continuous phase and two discontinuous phases, said discontinuous phases each being colorless but chemically reactive to form a stain if physically in contact. but which are kept from contact with one another by the continuous phase until said continuous phase is broken.

3. An emulsion having a continuous phase and a plurality of heterogeneous discontinuous phases which are chemically reactive on contact to form a perceptible mark but are physically separated by the said continuous phase under normal conditions which do not rupture the continuous phase.

4. A rupturable solid film having profusely dispersed at random therein two types of liquidcontaining cells of microscopic size, the liquids of the two types of cells being chemically reactive to produce a stain but normally physically separated by the solid until the solid is ruptured.

5. A solid film having profusely dispersed at random therein two types of discrete liquid-containing cells invisible to the unaided eye, said solid being rupturable by pressure to cause the contents of said ruptured cells to coalesce locally and react chemically so as to become visible.

6. The combination with a paper body, of a rupturable cellular coating thereon, the cells of said coating being profusely dispersed at random throughout the coating and containing colorless liquids which, when allowed to coalesce upon rupture of the coating, combine to produce a stain.

7. The combination with a paper body, of a coating comprising a plastic solid having profusely dispersed at random therein a plurality of kinds of liquid inclusions, said coating being resistant to ordinary handling but rupturable by printing impacts to coalesce the different kinds of liquid inclusions at the points oi impact, which coalesced liquids react to term a perceptible mark within the coating.

8. A coating for paper consisting of a plastic solid having profusely dispersed therein heterhaving dispersed therein Grams, Glycerine 33 Ferric ammonium sulphate-.. 3.2 Water 14 and the second of said emulsions being:

Grams lzl'solution of gum dammar in toluene 100 Di-(para tert-butylphenyl) mono-phenyl.

phosphate (CaeHsxOsPl 8.5 having dispersed therein Grams Glycerine 33 Gallic a 6.4 Water 14 both or said dispersed phases having a particle size of less than .1 millimeter in diameter.

phases being normally isolated from each other by the continuous phase but being chemically reactive to roduce a stain when the continuous phase is broken down to allow them to contact with one another. y

13. A solid having dispersed at random therein discrete inclusions of chemically heterogeneous liquids, said solid having been derived from a continuous phase oi an emulsion by drying and the liquid inclusions having been-the discontinuous phases of said emulsion. I

14. A liquid coating compositioii comprising an emulsion having a continuous phase and a plurality oi discontinuous chemically reactive phases. said emulsion being converted by drying into a rupturable solid continuous phase containing a plurality of liquid discontinuous phases which react to form a stain when they coalesce upon rupture oi the solid phase.

15. A sensitized record material comprising a base sheet having a coating of aplastic solid containing profusely distributed at random therein discrete inclusions oi liquids which are chemically reactive to form a visible mark, said coating being resistant to rupture in ordinary handling but rupturable by printing impacts to coalesce 10. The method of sensitizing paper to produce I visible marks by impact comprising the steps of applying a first coating consisting of an emulsion having a dryable continuous phase and a discontinuous phase'which remains as liquid inclusions in the dried continuous phase, and the step of applying a second coating over the first coating as said first coating has partially dried, said second coating being an emulsion having the same kind of continuous phase as the first coating and a discontinuous phase of a substance chemically reactive to the substance of the discontinuous phase of the first coating, the two mentioned discontinuous phases being partially interspersed in the coating but chemically separated by a common continuous phase.

11. The method of sensitizing paper to produce visible marks by impact comprising the steps of preparing a first emulsion having a dryable liq- 'uid continuous phase and a discontinuous phase of a rupturable solid cont the liquid inclusions and enable the chemical reactign to form visible marks at the points of impac 16. A sensitized record material comprising a base sheet having thereo a coating composed uous phase and containing a profusion of interspersed droplets of a plurality of discontinuous liquid phases which liquid phase are chemically reactive to produce a stain within the coating when allowed to coalesce upon rupture oi the continuous phase.

17. A sensitized record material comprising a base sheet having thereon a coating composed of a rupturable plastic continuous phase containing profusely dispersed therein microscopic discrete liquor inclusions oia plurality of chemically reactive substances which react to form a visible mark when allowed to coalesce and which are normally separated by the continuous phase but are released by the rupture of the continuous phase and react to form a visible mark at'the point of rupture.

18. A sensitized record material comprising a base sheet having thereon a coating composed of a rupturable plastic solid continuous phase which has profusely dispersed therein droplets of two discontinuous liquid phases which react to form a stain when allowed to coalesce by rupture of the plastic solid.

/ 19. Asensitized record material comprising a base sheet having thereon a colorless, transparent coating comprising a rupturable solid phase containing a profusion of discrete liquid inclusions of a plurality of discontinuous phases, the liquid in each of said discontinuous phases being clear ,and colorless while contained in the discrete inclusions but being chemically reactive to form a visible colored mark when allowed to coalesce upon rupture of the solid phase.

BARRE'I'I K. GREEN.

and two discontinuous phases, said discontinuous fi-sert. "finch forms a ruptnrable solid phase- .icnnna'icn'm or connscmion.

' October 20;, 191 2.

It in: hereby certified that error appea rsin the printed specification of the above mnnbered patent re qui'rin'g correction as follows: Page 5, first column, line 11., claim 8, for "A coating for paper consisting of" read The combination witnpeper, of'a coating compris1ng--; line 12, claim 9, after coating insert material.--; line k0, claim 10, before "and" inijo'r the words "a-common continuous" read -the common rupturable contin ii ioufl"; line 66, claim 11, after "phase" and before the periddinsert --'-to Ibnn a. m pturable solid coating containing profusely interspersed discrete inclusions of the two chemically reactive discontinuous phases--- li d seoond co umn, line '1, claim 12 after "phases" and before the comma insert firofdsel'y 'dispersdtherein-q line 2, same claim, afte i insert niicroscopic droplets--; lines 7,8 and 9 claim 15 for solid havingdispersed at random. therein discrete inclusions oichemic'ally heterogeneous liquids, saidsolid" read --A solid film having discrete incl lesions of chemically heterogeneous liquids profusely dispersedat random throughout it, said film-: line 16, claim 11;, for "converted? read "co vertible-. line #5, claim 17, for "'liquor" read -liquid-; and tha t th'e' said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 21pm day of November, A. D. lgiia.

Henry Van Arsdale,

"( 1) Acting Commissioner of Patents.-

lines51and 52, same claim,

. cert. which forms a r'uptfirable solid phaseicsRmrIcAm or commcnon.

--Pate nt no; 2,299,693. October 20, v151;.2.

of the above 'cnumbered patent requiring column, line 14., claim 8, 4 read 5 m n fi thps per, cf a ccating comprising--; line 12, claim 9, after "coatin'g' insert -me.teria1,--; line #0, claim 16, before "and" inlines 51 and 52, same claim, {or the words "acommon continuous read --the common rupturable continficus; line, 66, claim- 11, after "phase" and before the period insert iend second column, line 1, claim 12, after "thases and before the comma insert profusely dispersed-therein-'; line 2, same claim, after "bein insert n iicroscbpic droplets; lines 7, 8 and 9 claim f r having dispersed at random therein discrete inclusions of. chemically heter- 'ogeneous liquids, sa id'solid' read I out it, said film-E; line 16, claim 11+, for "converted" read "convertible--;' 111161 claim 17, for "'liquor" read ---liquid-; and the tithe said Letters Patent sheuld be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed ma sealed this 2mm da of November, A. n. 19u2.

Hem-y va Arsdale,

( Acting Connnissioner of Patents.

Page 5, first ."A solid film having discrete incltlsions of chemically heteregeneeus liquids 'promsel-y dispersed-at random thrcugh-

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