US2313808A

US2313808A - Copy and recording paper

Info

Publication number: US2313808A
Authority: US
Inventors: Harold R Dalton
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-02-26
Filing date: 1941-02-26
Publication date: 1943-03-16
Anticipated expiration: 1960-03-16

Description

March 16, 1943. H. R. DALTON COPY AND RECORDING PAPER Filed Feb. 26, 1941 R E P A P NORMALLY OPAQUE COATING INVENTOR HAROLD R. DALTON ATTORNE UNITED STATES, PATENT OFFICE 'corr AND aacoanmo rat-an Harold R. Dalton, 'l'eaneck Township, Bergen County, N. 1.

Application February 26, 1941, Serial No. 380,817

The invention relates primarily to to produce copies on a typewriter or similar machine without; the employment of carbon paper, but it may also be'employed with pen, pencil or stylus and in presses for printing from type or plates as well as by typewriter with or without ink.

Heretofore there has been used copy paper consisting essentially of a colored paper coated on one side with a soft light weight coating of such materials as waxes and fats alone or combined with rosin, stearic acid, clay, zinc oxide or dye. Suiiicient of this coating material is so applied to the colored paper as to mask the color of it and give the coated surface a gray appearance. In typing the blow from the type through the first or original sheet is sufllcient to spread or remove the coating where the type has struck and expose the colored paper to some extent, thus producing a copy of the typing.

There are several serious drawbacks to the use of the above mentioned copy papers, including the low melting point of the coatings, which is usually below 130 F., the poor contrast between the characters produced in typing and the color of the coated surface, and their rather unattractive appearance. The low melting point of the coatings restrictsthe use of the papers to the colder climates and necessitates care in handling to protect their delicate surfaces from being destroyed by heat. stricted in their use because of the rather poor contrast between characters and coating which makes the typing diflicult to read unless the light is very good and the unattractive appearance of the gray inherent color of the coatings.

The object of this invention is to produce a copy paper which is free from all oi the objections stated and which will serve satisfactorily as a copy and recording paper. Such a paper is particularly adapted for intra oillce and intra plant letters and memoranda, for billing machines where du'plicates are used and for many other purposes, and dispenses with the use of carbon paper or the like and eliminates the trouble and inconvenience incident to the'handlingof carbons. It may also be used for graph paper used for recording instruments and the like and will dispense with the customary inking devices.

The emulsions or dispersions here described may be applied to various weights and quality oi. paper having a surface which is not too highly calendered or coated but which may be machine finished or somewhat rough and porous. The

The papers are also reloclaims. (Cl. 282-28) paper used 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 handling 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 flrst'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, a sheet. coated according to the present improvements being used in that case for the original. v

In the accompanying drawing is illustrated a magnified perspective view of a copying and recording paper, according to the invention, with a portion of the surface coating removed.

In practicing the invention a rather smooth light weight colored paper i is provided with a coating 2 in the form of a water dispersion or emulsion of a polyvalent metal soap (also known in the art as a metallic soap), and a binding agent. The paper may be black or colored red, blue, orange, etc., as desired. A large number of polyvalent metal soaps may be found which will give satisfactory results. g 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 a polyvalent metal with a fatty acid, or its equivalent, and is intended to include salts of naphthenie 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.

The binding agent may consist of a wide va- I riety of materials such as waxes, gums. cellulose coating may be applied in any suitable manner ethers or esters, etc. Although referred to as a binding agent 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 must also serve as a base for the polyvalent metal soap and allow the coating to spread slightly on the paper when a light blow or pressure is applied such as that from a character of 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 penoil, removes to a certain extent the concealing coating and otherwise makes visible the contrasting paper on which the coating has been applied. It will 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. The amount 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 comditions 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. Copy and 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 with 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.

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 or 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 sufficiently 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 paperappearing where the coating has been acted upon.

A water dispersion or emulsion of the binders mentioned above can be prepared by any of the well known methods used in th 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 and 75%, depending upon the type of coating desired and to what particular use the copy and recording paper will be put. The coating may be applied by the ordinary paper coating methods such as spraying, dipping,'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.

1. 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 0. 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 distributed. 300.0 c. 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.

A method of preparing a water dispersion or emulsion of a polyvalent metal soap and cellulose nitrate: Th cellulose nitrate is used in the form of a lacquer containing some plasticizer and solvent: 60.0 grams of clear commercial lacquer (cellulose nitrate #1001012 lacquer manufactured by Valentine 8; 00.), 20.0 grams of castor oil and 30.0 grams of stearic acid are melted together and slowly added to 30.0 grams of triethanolamine dissolved in 400.0 0. c. of water at 90 C. 100.0 c. c. of this cellulose nitrate dispersion or emulsion is mixed with 50.0 grams of Zinc stearat 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 F.

3. A method of preparing a water dispersion or emulsion of a polyvalent metal soap and a blend of waxes to form th coating: 40.0 grams of bees wax, 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 0. c. of water at 90 C. 100.0 0. c. of this wax emulsion or dispersion is mixed with 50.0 grams of aluminum palmitate and 3.0 grams of Methocel (15 cps.; methyl cellulose). Additional water is added to produce a consistency satisfactory for application to paper. Before applying 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 soap and a blend of waxes using polyvinyl alcohol as the dispersion or emulsifying agent: 60.0 grams of bees wax and 20.0 grams of Opalwax (manufactured by the E. I. du Pont de Nemours 8: C0.) are melted together and slowly added to a solution of 10.0 grams of polyvinyl alcohol (RH-488, manufactured by the E. I. du Pont de Nemours & Co.) in 100.0 c. c. of water at C. The polyvinyl alcohol solution is kept agitated or circulated rapidly and continuously. After the emulsion has become stable it is diluted with 300.0 0. c. of water. 100.0 0. c. of this emulsion 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 produced by dyeing in the pulp or a color treatment applied after the paper is made on one or both surfaces.

What I claim is:

1. A paper of the kind, indicated composed of a colored sheet having a coating the base of which consists mainly of a polyvalent metal soap held in a waxy material and having the characteristic of .being rendered transparent by pressure thereon as of type, pen, stylus or pencil to expose the color of the base sheet where the pressure is applied.

2. A paper of the kind indicated composed of a colored sheet having a coating the base of which consists mainly of a polyvalent metal in a waxy material and substantially free from fatty acids said coating having the characteristic of being rendered transparent by pressure thereon as of type, pen, stylus or pencil to expose the color of the base sheet where the pressure is applied the polyvalent soap being evenly distributed in the waxy material and the said material and soap being spreadable by pressure.

3. A paper of the kind indicated composed of a colored sheet coated with an opaque polyvalent metal soap dispersion held in a waxy material and having the characteristic of being rendered transparent by pressure thereon as of type, pen, stylus or pencil to expose the color. of the base sheet where the pressure is applied.

4. A paper of the kind indicated composed of a colored sheet coated with a white opaque material the base of which consists mainly of a polyvalent metal soap in a finely divided state soap held '3 held and distributed in a wax-lik substance to sufilcient thickness to conceal the color of the base and said wax-like substance facilitating the spreading of said material to render it transparent in response to localized pressure as of type striking thereon to expose the color of the base sheet at the areas of pressure.

5. A copy and recording paper consisting of a light weight colored paper having applied to a surface a coating the base of which consists mainly of a polyvalent metal soap and a water resistant binding agent.

6. A coating mixture for use in the manufacture of a copy and recording paper said mixture consisting mainly of a water dispersion or emulsion of a polyvalent metal soap and a binding agent.

7. A paper of the kind indicated composed of a colored base sheet coated with'a metallic soap in a waxy material said soap having the characteristic of being rendered transparent by pressure thereon as of type, pen, stylus or pencil to expose the color of the base sheet where the pressure is applied and said material being spreadable' permanently by such pressure and said waxy material acting as a binder and also facilitating the spreading of said coatlng'in response to said pressure. Q

8. A copying sheet consisting of a backing of a thin flexible material such as a light-weight paper carrying a c'opying layer in'the form of a dried emulsion the base of which consists mainly of a polyvalent metal soap and having a waxy binder, which layer has the properties of being normally substantially opaque and of becoming substantially transparent in localized areas when subjected to localized pressure or impact.

9. A printing medium comprising a support having a coating consisting mainly of a substantially water-insoluble polyvalent metal soap incorporated with a binder.

10. A printing medium according to claim 9 in which the support is of porous pliable material and'the soap is of the polyvalent metal type with a waxy binder.

HAROLD R. DALTON.