US2313810A - Copying and recording medium - Google Patents

Description

March H. R. DALTON 1 2,313,810

7 COPYING AND RECORDING MEDIUM Filed July 8, 1941 COLORED PAPER COLORED PAPER PIGMENT- BE ARlNG TRANSFER COATING INVENTOR HAROLD R. DALTON Patented 16, 1943 UNITED STATES PATENT OFFICE corrmo AND aacoanmo smnmu Harold n. Dalton, Teaneek, N. J. 7 Application July a, 1941, Serial No. 401,530

4 Claims. (0. ass-2a) This invention relates to'copying, transfer, or

recording mediums and more especially to such mediums in the form of a web or sheet of pliable material having a coating or coatings for effecting copying,- transfer or recording.

While the invention finds its greatest utility in the making of copies or transfers under control of such devices as typewriters, printing telegraph machines, telefacsimile machines, stencil machines and thelike, it is also of pronounced utilbeen roughly divisible into two groups. The first group includes those wherein the coating material is transferred from a web or sheet to the receiving surface and typical of which are the customary "carbon" papers used in typewriting and the like. The second group includes those wherein the coating material has its ch'aracteristics changed by impact of a printing hammer, type bar or the like, so that the copy or record is made on the same sheet or web which carries the coating. For purposes of simplicity in the ensuing description, the first group will be referred to as indirect copy medium, while the second group will be referred to as direct" medium. .One of the main objections to the prior known copying mediums of both the "direct" and indirect" kinds, is that they require the coating to be constituted in greater part with wax or wax-like or fatty substances, either alone or in conjunction with resin, stearic acid, clay, zinc oxide or dye. Because of the large percent of waxes in such prior mediums, the coatings have a melting point which is usually below 130 1".,'

thus restricting their utility to the colder climates and to low temperature conditions; requiring care in handling to prevent the relatively delicate coatings being destroyed by heat or friction. In the case of prior direct copying medium, the coating was applied to a colored paper, the waxlike coating being sufficiently thick to mask the color of the paper. These direct copying papers are used in much the same manner as ordinary carbon paper so that when the type bar or similar pressuredevice makes an impression on the original or first sheet, the pressure is transmitted to the wax-like coating and asa result the coating thickness is changed at thearea of impression and reveals the colored backing paper in accordance with the outline of the letter or character printed on the original or first sheet. Apart from the temperature limitations of such waxlike coatings, it has not been possible heretofore to provide a coating which issubstantially white. On the contrary, the prior wax coatings have a bluish or bluish gray appearance, so that it is not possible to produce a very marked contrast between the exposed backing paper and the unaffected wax coating. I Thus, copies produced on these prior papers are difllcult to read. Furthermore, the wax surface is very susceptible to ageing and smudging which militate against the permanence of the record.

Accordingly, it is a principal object of this invention to provide a coating material suitable either for direct" or "indirect". copy work, which typewritten matter, it is of equal importancein any situation where a record is to be made without employing carbon papers or the like. Examples of such uses may include, graph paper, recording webs for recording instruments generally such as tele-facsimile recording machines, printing telegraph machines and the like.

Another principal object of the invention is to provide an improved carbon paper which does not employ a large percentage of wax or waxlike substances as the retention medium for the carbon pigment. V

Another object is to provide a carbon paper which 'is relatively free from curling when sub,- iected to humid conditions.

A feature of the invention relates to a carbon or indirect copy medium which can be made with relatively low grade backing paper without dan-- ger of the coating material seeping through to the uncoated side of the paper.

Another feature relates to a carbon paper I which is materially less expensive to manufacture than customary waxy carbon papers.

Another feature relates to an indirect copy medium which is less subject to the deleterious A further feature relates to a copying paper 1 of the carbon'type which employs a minimum of or web which can be used either as a "direct" printing medium or as an findirectf printing medium.

A still further feature relates to the novel orgazination, arrangement and relative proportions and composition of parts which constitute an improved copying or recording blank.

Other features and advantages not specifically enumerated will be apparent after a consideration of the following detailed descriptions and the appended claims.

Fig. 1 is a magnified perspective view of a copying paper, according to the invention, with a portion of the surface coating removed. Fig. 2 is a modification of Fig.- 1.

While in the following description reference will be made to the manufacture of copyin or recording paper," it will be understood that in certain of its aspects the invention is not necessarily limited to paper but may be applied to any other sheet. web or blank such as plastics, glass, metal, fabric etc. Furthermore, where reference is made to a colored" paper, it will be understood that the term "colred is used in its broadest significance to include black, white or any other tint or shade.

Direct printing medium paper having a surface which is not too highly calendered or coated but which may be machine finished or somewhat rough and porous. The coating may be applied in any suitable manner and in thicknesses of one one-two-thousandths of an inch or more and will add very little to the cost of ordinary uncoated paper, while saving the cost of carbons and the work of handlin them. When used on the typewriter the sheets are superposed with their coated faces upward, and with very light paper as many as ten distinct copies can be produced at a time. An ordinary typewriter inking ribbon may be employed for the first or original copy using a plain sheet of paper, or if desired, the-first or original copy may also be made without the use of an inking ribbon,

colored red, blue, orange, etc., as desired. A.

large number of polyvalent metal soaps may be found which will give satisfactory results. However, those most desirable should have a high melting point and a pure white color at ordinary temperatures. The expression polyvalent metal soap is here used to denote a salt formed by the interaction of apolyvalent metal with a fatty acid, or its equivalent, and is intended to include salts of naphthenic acid, an acid obtained from the refining of petroleum. The stearates of calcium, magnesium, zinc, aluminum, lead, etc.,

and the palmitates of aluminum, zinc, etc., are good examples of such polyvalent metal soaps that can be used in the coating.

variety of materials such as waxes, gums, cellulose ethers or esters, etc. Although referred to as a bindingagent it should be understood that these materials beside acting to bind the particles of polyvalent metal soap together and to the surface of the copy and recording paper a typewriter. This action together with the fact that the polyvalent metal soaps tend to become transparent when subjected to pressure, as that produced-by characters of a typewriter'or pen stylus or pencil, removes to a certain extent the concealing coating and otherwise makes visible the contrasting paper on which the coating has been applied. Itwill therefore be evident that certain binding agents will require the addition of a plasticizing agent to them to give to the coating its spreading properties. Cellulose derivatives are examples of such binding agents and require the addition of a plasticizing agent such as castor oil or tricresyl phosphate, etc. Theamount of plasticizer necessary will depend on such factors as the type of cellulose derivative selected, whether a resin is used with the cellulose derivative or not, the hardness of the coating desired, etc., and-will have to be determined by the conditions and by ordinary tests. Waxes may be blended together to produce the desired effect and do not require a plasticizing agent. If desired the coating may be colored to contrast with the base sheet.

It is desirable but not necessary to select as the binding agent a material that is not water soluble. Copyand recording paper made with water soluble binding agents will be affected by moisture and the coatings destroyed when placed in contact with water, or in climates of high relative humidity. Gelatin and certain gums properly plasticized withv glycerol or ethylene glycol, etc., are water soluble binders that may be used. The resistance to moisture in the case of gelatin can be improved by properly hardening or tanning with formaldehyde or potassium dichromate. 1

Binders like the waxes and cellulose derivatives dissolved in an appropriate solvent when mixed with the polyvalent metal soaps dissolve them and only a transparent coating is produced when they are applied to the colored paper. It has been found that the dissolving of the polyvalent metal soaps can be prevented if the binding agents are properly prepared as water dispersions o'r emulsions first. before mixing. The resulting dispersion or emulsion containing the polyvalent metal soap can then be applied to the colored paper to produce a copy and recording paper having a melting point anywhere from 210 F. to

. 300 F. depending on the polyvalent metal soap and binding agent selected. The coating will also have a good color and appearance. -When used as a copy paper in a, typewriter the coating is removed sufiiciently to form a perfect reproduction of the character formed on the first or original typing sheet. The character becomes visible as a result of the colored paper appearin where the coating has been acted upon.

The binding agent may consist of a wide A water dispersion or emulsion of the binders mentioned above can be prepared by any of the well known methods used inthe art. For instance, good dispersions or emulsions can be prepared by using sodium or potassium soap, amine soaps, such as triethanolamine, cyclohexylamine, morpholine, etc., methyl cellulose,

polyvinyl alcohol and so-called dispersion agents like certain esters of higher fatty alcohols, etc.

The percentage of polyvalent metal soap present in the final coating dispersion or emulsion,

based on the amount of solid material contained therein, can be varied approximately between 10% and 75%, depending .upon the type of coating desired and to what particular use the copy and recording paper will be put; The coating maybe applied by the ordinary paper coating methods such as sprayingndipping, brushing and knife coating, and this coating is finished and solidified and the product completed by heating or otherwise evaporating the liquid therein, and possibly applying a light pressure to smooth off the surface.

The following exemplary embodiments of this invention are included for purposes of, illustration and should not be construed as representing limitations.

l. A method of preparing a water dispersion of polyvalent metal soap and carbowax, a water soluble wax-like material used as a binder; 30.0

grams. of carbowax (1500) and 40.0 grams'of,

carbowax (4000) are added to 100.0 c. c. of water and the mixture heated until a clear solution is obtained. 40.0 grams of calcium stearate and 4.0 grams of methocel (15 cps.-; dissolved in 25.0

c. c. of water) are added to this solution and mixed until the calcium stearate is well dis- 1 tributed. 300.0 0, c. of water is then added and the mixture passed through a colloid mill in order to obtain a uniform suspension.

Carbowax is manufactured by Carbide and Carbon Chemical Company. Methocel is the trade name for methyl cellulose manufactured by The Dow Chemical Company. Both are obtainable in the open market.

A colored paper coated with this coating will have a melting point of approximately 210 F;

2. A method of preparing a water dispersion or emulsion of a polyvalent metal soap and cellulose nitrate. The cellulose nitrate is used in the form of a lacquer containing some placticizer and solvent: 60.0 grams of clear commercial lacquer (cellulose nitrate #1001012 lacquer manufactured by Valentine a 00.), 20.0 grams of castor oil and 30.0 grams of stearic acid are melted togetherand slowly .added to 30.0 grams of triethanolamine dissolved in 400.0 c. c. of water at 90' C. 100.0 sic. of this cellulose nitrate dispersion or emulsion is mixed with 50.0 grams of zinc stearate and 3.0 grams of methocel (15 cps.; methyl cellulose). Additional water is added to produce a consistency satisfactory for application to the colored paper. Before applying to the paper the coating should be passed through a colloid mill.

A colored paper coated with this coating will have a melting point of approximately 220 1'.

.3. A method of preparing a water dispersion or emulsion of a polyvalent metal soap and 'a blend of waxes to form the coating: 40.0 grams of beeswax, 40.0 grams of carnauba wax and 40.0 grams of stearic acid are melted together and slowly added to 20.0 grams of morpholine dissolved in 400.0 c. c. of water at 90 C. 100.0 0. c.

of this wax emulsion or dispersion is mixed with g 50.0 grams of aluminum palmitate and 3.0 grams of methocel (15 cps.; methyl cellulose). Addipaper.

water.

plying to the colored paper the 'coating should be passed through a colloid mill.

A colored paper coated with this coating will have a melting point of approximately 300 F.

4. A method of preparing a dispersion or emulsion of polyvalent metal soapand a blend of waxes using polyvinyl alcohol as the dispersion or emulsifying agent: 60.0 grams of beeswax and 20.0 grams of opalwax (manufactured by the E. I. Du PontDe Nemours 8: Co.) are melted together and slowly added to a solution of 10.0

grams of polyvinyl alcohol (RH-488, manufac tured by the Ej I. Du Pont De Nemours 8: Co.) in

The polyvinyl al- 100.0 0. c. of water at 85 C. cohol solution is kept agitated or circulated rapidly and continuously. After the emulsion has become stable it is diluted with 300.0 c. c. of 100.0 0. c. of this emulsionv is mixed with 50.0 grams of magnesium stearate and additional water added to form the coating.- Before applying to the paper the, coating should be passed through a colloid mill.

A colored paper coated with this coating will have a melting point of approximately 230 F.

In each of the examples above "given the liquid prepared is applied to the paper as a thin, even coating in any suitable manner, such as. those previously mentioned, and allowed to dry and set,

so that the color of the base paper is substantially masked. The color of the paper may be pro-' duced by dyeing in the pulp or a color treatment applied after the paper is made on one or both surfaces. 1

, Indirect printing medium While the-foregoing specifications have dealt primarily'with coated papers which are capable of producing a record directly thereon, similar procedure can be used to manufacture indirect printing papers such as carbon papers. In the manufacture of the usual type of carbon paper, there are several conditions and problems which must be met, thus the carbon particles must be suspended or imbedded in a relatively thick layer of wax or waxy substance, the thickness of the wax being necessary because after a time the wax tends to seep through the surface of the This condition therefore, requires the use of comparatively expensive papers to support the carbon-wax coating and prevents the use of cheap porous papers. In accordance with the invention, the coatings or emulsions are, for the hms and does not readily curl as do ordinary tional water is added to produce a consistency satisfactory for application to paper. Before apmost part of a metal soap which does not have the seepage characteristics of wax, and therefore I have found it possible to use these soaps as substitutes for the ordinary wax coating permitting the use of relatively cheap and comparatively porous backing paper. ordinary wax carbon papers must be manufactured and coated under closely controlled temwax carbon papers.

In the manufacture of carbon paper according Furthermore, the

to the invention, the backing paper may be any cheap grade of the required thinness and weight and it may be blue, black or any other color desired. The paper iscoated with an emulsion or dispersion of a polyvalent metal soap or mixture thereof prepared and applied in accordance with any of the examples hereinabove described for direct printing mediums. In the case of carbon paper however, a suitable percentage oi carbon black, pigment, lake or other similar material is added to the emulsion or dispersion sothat when the paper is subjected to pressure against -a copy sheet, for example by a type bar or the like, the coating is sufficiently brittle and tacky- Y a minimum any pigments or granular material that would prevent spreading of the coating or any material that will cause the coating to be transferred or any material which will prevent the coating to becoming transparent. While in such direct printing papers, the presence of a small percent of dye will not greatly change the desired properties for direct printing,a material like carbon black or pigment when added to the coating will greatly modify the: direct printing properties according to the amount of carbon black or pigment which is used.

In certain cases, it may be desirable to make the paper .a composite one, that is one side may be coated with the polyvalent soap or soaps as above described substantially free from carbon black, pigment or the like, so that that particular side of the paper acts as a direct printing medium; whilethe reverse side of the paper may be covered with the polyvalent soap or soaps containing sufficient carbon black, pigment material or the like to cause this particular side of the paper to act as a transfer or carbon paper.

The invention is also applicable to the making of stencils. Thus the coating may be applied to a backing of dark "Ce1lophane or any other application Serial No.

backing usually employed for stencil blanks. The surface of the blank is then coated with a polyvalent soap or soaps as above described having the property of spreading or thinning at the area of impact of the type bar or hammer to reveal the dark suri'ace of the backing sheet with the result that the stencil record can be used in the ordinary way as a stencil blank and the stencilled record is, visible as it is made on the blank. For this purpose, of course, thebacking paper should be of a contrasting color with the polyvalent soap coating.

While certain specific materials, proportions of parts and uses have been described herein, it will be understood that various changes and modifications .may be made without departing from the spirit andscope of the invention. Thus any substantially water insoluble metal soap having the. characteristics of a polyvalent metal-soap may be employed. Preferably the polyvalent metal soaps are formed as salts of a fatty acid containing eight or more carbon atoms. The expression dispersion or disperse phase as employed in the attached claims is used in a broad sense to includecolloids, suspensoids, emulsions and emulsoids. 1

This application is a continuation-in-part of 380,617, filed February 26, 1941. 4

What I claim is:

1. A printing medium comprising a support having a transfer coating consisting mainly of a polyvalent metal soap incorporated with a binder and a quantity of pigment material.

2. A transfer printing medium consisting mainly of a polyvalent metal soap in disperse phase having incorporated therewith a quantity of pigment material.

3. A transfer printing medium comprising a pliable support having a coating consisting mainly of a. polyvalent metal soap dispersion mixed with a pigment, the coating having a melting temperature of not less than 200 F.

4. A printing medium comprising a web of pliable material, a transfer coating on one side of.

said web, a direct printing coating on the other side of said web, each of said coatings consisting mainly of a normally opaque polyvalent metal soap, said transfer coating containing also a quantity of pigment material.

' HAROLD R. DALTON.

Images