US3076406A

US3076406A - Duplicating method and element for use therein

Info

Publication number: US3076406A
Application number: US458964A
Authority: US
Inventors: Robert T Florence
Original assignee: AB Dick Co
Current assignee: AB Dick Co
Priority date: 1954-09-28
Filing date: 1954-09-28
Publication date: 1963-02-05
Anticipated expiration: 1980-02-05

Description

United States Patent 3,076,406 DUPLICATING METHOD AND ELEMENT FOR USE THEREIN Robert T. Florence, Park Ridge, 111., assignor to A. B. Dick Company, Niles, Ill., a corporation of Illinois N0 Drawing. Filed Sept. 28, 1954, Ser. No. 458,964 3 Claims. (Cl. 101-149.5)

This invention relates to a copy process and to materials for use in the practice of same. It relates more particularly to a new and improved process for the reproduction of multiple copies embodying improvements over the present type of spirit or hectograph duplicating systems.

To the present, reproduction processes of the type described have been effected by systems generally referred to in the art as the gelatin system and as the spirit duplicating system. In the gelatin system, a master sheet is imaged by typing, writing or drawing with an ink composition containing a water soluble dye, usually crystal violet. The image is transferred in reverse by absorption during contact into a gelatin compound disposed in a pan or on the surface of a transfer sheet which then forms the printing medium. The water soluble dyestuff transfers from the moist printing medium to form copy upon contact with impression medium.

In the spirit duplicating system, the' image is formed in reverse on a master by transfer from a carbon type sheet coated with a composition containing a high proportion of a water soluble dye such as crystal violet, Victoria green, Victoria blue and the like. The image transfers from the master to copy sheets, the surfaces of which have been wetted with an alcohol or alcohol and water combination upon contact, as between a compression cylinder and a printing plate mounted in a rotary duplicating machine. The highly volatile solvents permit the production of a larger number of copies and provide for more rapid drying of the copy sheet to reduce setoff and smear. In the spirit duplicating systems, the dyestuif is preferably contained in a coating such as in a carbon sheet for trans fer in mirror image onto the printing master by the application of force or the like.

While hectograph and presently known spirit duplicating systems of the type described are desirable from the standpoint of their flexibility in use and simplicity. in operation, these processes have for a number of years been confronted with serious objectionable features. The most objectionable characteristics stem from the .highly dispersible fine particles of the dyestuff and from the highly soluble nature thereof in aqueous medium. The fine particle size of the dyestuif employed in the practice of the present systems leads to objections in their use for the manufacture of carbon transfer sheets or inking ribbons employed in the manufacture of the imaged master. In most manufacturing processes, the atmosphere in and about the formulating and coating room becomes contaminated with fine particles of the dyestulf whereby the personnel within the buildings and the territory surrounding the buildings acquire a characteristic purplish color.

Because of the highly water soluble nature of the dyestulfs which have been employed to the present in the practice of the spirit hectograph and duplicating systems, moisture on the hands of the operator is sufficient to remove a suflicient quantity of the dyefrom which it generally spreads to other parts of the body and clothing. It is difiicult even with the most extensive precautions to operate a hectograph or spirit duplicating system em bodying such dyestulfs without staining ones hands and clothing and without finding such discolorations from the dyestufr" existing on almost all surfaces within the vicinity of the duplicating machine. bjec of his provide a ystem 3,076,406 Patented Feb. 5, 1963 2. which is as simple and as flexible as a spirit or hectograph duplicating system but which is substantially free of such objectionable features of such prior art processes as heretofore employed.

Another object is to provide a duplicating system of the type described which is free of compounds capable of coloring or dirtying ones hands, clothing, or the atmosphere or environment during the manufacture and use of the elements employed in the copy process.

A further object is to provide a duplicating system in which permanent copy of good quality is secured.

More specifically, it is an object of this invention to provide a new and improved duplicating system and materials for use in same wherein the materials involved in the manufacture and use are incapable of color transfer value and wherein the copy is developed in the copy sheet itself thereby to permit the formation of copy by reaction to produce an insoluble product which remains permanently in the copy sheets.

In the copending application Ser. No. 287,616, filed May 13, 1952, description is made of an organic dye system which overcomes the objectionable features of the present spirit and hectograph duplicating systems and which provides a new and clean duplicating process withoutloss of the desirable features of the present processes. As described in the aforementioned application, instead of forming the image on the master with a basic aniline dye that is highly soluble in water or spirit solvents, as in the processes heretofore employed in gelatin or in spirit duplicating systems, the image is formed on the master of a water and/or alcohol soluble component of an azo dye and in which the component has no objectionable color transfer value in the state in which it exists in the master, imaging composition, inking ribbon or carbon sheet with which the master is formed but which upon transfer to the copy sheet forms an azo dyestuff by reaction with other components contained in a non-reactive state in the imaged master or contained in the fluid with which the copy sheet is wetted prior to contact with the imaged master for effecting transfer of the imaging components from the imaged master to the copy sheets or in the copy sheet itself or else contained in a fluid applied to the copy sheet subsequent to transfer of the imaging material from the master.

It has been found, in accordance with the practice of this invention, that similar concepts may be employed in a system which makes use of a Water and/ or alcohol soluble salt of a metal capable of reaction with another preferably alcohol and/ or water soluble compound to form an intensely colored reaction product in the form of a complex of the two materials. As in the system of the aforementioned application, one of these compounds may be contained as the component free of any dye color in the imaging master while the other is contained in the copy sheets or preferably in the fluid with which the copy sheets are wetted prior to contact with the imaged master or both of these components may be contained in the material with which the master is imaged when another material such as a base is employed as a component in the fluid or on the copy sheets and which is used to control the reaction in forming the intensely colored complex as a reaction product.

The concepts of this invention may be capable of a number of modifications which will hereinafter be described in greater detail. For purposes of illustration, but not of limitation, examples will now be given of one mode of carrying out the inventive concepts embodied herein.

EXAMPLE 1 -Transfer sheet:

fibrous base sheet with a composition compounded of the following materials:

12.0 percent by weight carnauba Wax 17.0 percent by weight microcrystalline wax 14.5 percent by weight heavy mineral oil 13.0 percent by weight light mineral oil 1.5 percent by weight sodium oleate 42.0 percent by weight nickel acetate The composition described above is reduced to a molten state at a temperature of about 80-90 C. for application as a hot melt onto the surface of the base sheet preferably in concentrations ranging from 15-30 pounds per 3000 square feet of surface area. The applied coating remains as a layer concentrated on the surface of the base sheet for enabling transfer onto an imaged master brought into surface contact therewith upon application of external force such as heat from a heat pattern or compression by means of a typewriter key, writing pencil, pen or stylus.

EXAMPLE 2 For preparation of the imaged master, the coated sheet manufactured in accordance with Example 1 is positioned with the coated side in surface contact with the prepared surface of a suitable master sheet whereby coating material is displaced from the coated base sheet to the surface of the master to form a mirror image thereon in response to forces applied against the uncoated side of the base sheet as by the means described including die impression.

EXAMPLE 3 Fluid composition: Methanol containing dithiooxamide in concentrations of 1 gram per liter of methanol.

EXAMPLE 4 Preparation of copy:

For the production of multiple copies, the imaged master prepared in accordance with Example 2 is mounted on a cylinder of a rotary duplicating machine of the conventional type used for spirit duplication. The copy sheets advanced through the machine are wetted as by means of a wick having an end portion immersed in a reservoir of the fluid of Example 3 prior to contact between the wetted surface of the copy sheet and the imaged surface of the master. As the wetted surface of the copy sheet moves into surface contact with the imaged master between the pressure roller and the cylinder mounting the master, some of the nickel acetate is leached from the imaging material for transfer in small amounts to the copy sheets where reaction takes place between the nickel acetate and the dithiooxamide to form a colored water insoluble reaction product.

In the preparation of a carbon sheet as described in Example 1, coatings of the desired weight are preferably made from a hot melt applied onto a suitable paper base sheet by conventional coating technique, such as by a roller coater, knife coater, spray coater, dip squeeze proc- 'ess or the like. The coating composition is incapable of flow when cooled to room conditions but remains concentrated on the surface of the base sheet so as to be capable of transfer substantially completely in certain areas responsive to externally applied force to form a mirror image on the surface of a suitable master sheet placed in contact therewith. While it is preferred to apply the coating composition as a hot melt in the manner described, the desired transfer coating may be formed on the base sheet by application of the materials from solvent solution, aqueous dispersion or emulsions. In the use of such compositions, the materials will usually be present in lesser concentrations with the result that it will usually require more than one coating to provide the desired coating weights on the base sheet.

It is desirable to embody as high concentration of the reactive component as possible in the carbon coating consistent with the ability of the coating to maintain the desired film characteristics and strength for transfer. Generally the amount of the reactive component present as an ingredient in the coating composition depends on the ability for maintain sufiicient fluidity under the conditions existing to achieve the desired application and coverage of the base sheet. For the production of a large number of copies of sufficient intensity, it is desirable to maintain the concentration of the reactive component or components in amounts greater than 20 percent by weight of the coating and preferably in excess of 50 percent by Weight. In general, fluidity of the desired character falls off when the concentration of the reactive component or components for use in forming the image on the copy sheet reaches 75 percent by weight of the composition but more may be used with the introduction of suitable fluidizing agents. As the metal salt, it is preferred to make use of a water and/or alcohol soluble salt of a metal having an intensely colored sulphide, such for example as the water soluble salts preferably of nickel, cobalt, copper, lead and the like, and of iron, beryllium and the like. Instead of nickel acetate in Example 1, use may be made of one or more of the following metal salts in similar concentrations:

Nickel chloride Nickel formate Nickel sulphate Cobalt acetate Cobalt chloride Cobalt iodide Cobalt sulphate Copper acetate Copper lactate Copper nitrate Copper sulphate Lead acetate Lead formate Lead chloride Lead sulphate Ferric chloride Beryllium chloride Instead of dithiooxamide, use may be made of other water and alcohol soluble compounds capable of reaction with the metals to form the desired reaction products.

While it is more economical to place the water and alcohol soluble metal salt in the carbon sheet or imaging material, it Will be evident that the concepts of this invention may be achieved when the dithiooxamide or equivalent material is compounded as a component in the carbon sheet or imaging composition with the soluble metal salt contained in the wetting out fluid or else in the copy sheet adapted to be wetted with a suitable fluid for leaching the reactive component from the imaging material of the master upon contact for reaction to form the copy as a colored reaction product.

EXAMPLE 5 A coating composition for preparation of a transfer or carbon sheet embodying the modification described above may be formulated of the following:

8.5 percent by weight carnauba wax 14.0 percent by weight oxidized microcrystalline wax 12.0 percent by weight petrolatum 15.5 percent by weight mineral oil 50.0 percent by weight dithiooxamide Application of the above onto a suitable paper base sheet may be made in weights of about 20 pound per 3000 square feet from a hot melt operating at a temperature of about -100 C.

When the imaging composition is formulated to contain the water or alcohol soluble dithiooxamide or other metal complexing compound as described in Example 5, the

EXAMPLE 6 2.0 percent by weight nickel tormate 80.0 percent by weight methanol 18.0 percent by weight water By way of still further modification, it is possible, in acordance with the practice of this invention, especially when the materials are dispersed as separate ingredients in a non-solvent medium such as a wax base of the type describe-d in Examples 1 and 5, to place both the water and alcohol soluble metal salt and the dithiooxamide or other water and alcohol soluble thio or sulphur containing compound in the coating composition or the imaging material. Under such circumstances, the fluid is formulated to contain the solvent for leaching the reaction products from the imaged master and it may be formulated further to contain alkali used to control the reaction and to produce more intense copy.

By way of still further modification, it is possible to embody one of the water or alcohol soluble components for the reaction in the imaging material as illustrated in Examples 1 and 5 and then produce copy in the impression paper by first wettingthe surfaces of the copy sheets with a solvent medium to leach some of the reactive component from the imaged master to the copy sheet and thensubsequently wet the surface of the copy sheet witha second fluid system containing the other reactive component such as dithiooxamide for use with the master imagedwith the composition of Example 1 or nickel acetate or the like metal salt for use in producing copy with a master-imaged with the composition of Example 5.

By way offurther illustration of the practice of this invention, the following will set forth additional formulations for use of one component in the coating and the other complexing compound in the fluid, but it will be understood that the various permutations previously described may similarly be employed by interchange of the reactive components between the fluid and the imaging material or within aseries of fluids as long as one of the components is present in the transfer coating or other material with which the master is imaged.

- EXAMPLE 7 Transfer coating:

23.4 percent by weightcarnauba wax 11.8 percent by weight castor oil 11.8 percent by weight mineral oil 53.0 percent by weight iron chloride EXAMPLE 8 Fluid for master imaged with composition of Example 7:-; v 1

33.0 percent by weight polyethylene glycol, molecular weight average 6000 (Carbowax 6000) 34.0 percent by weight dimethyl glyoxime EXAMPLE 10 Fluid for use with imaging material of Example 9:

90.0 percent by weight ammonium hydroxide (14% NH OH) 10.0 percent by weight nickel sulphate 6 EXAMPLE 11 Transfer coating:

EXAMPLE l2 Fluid for imaging composition of Example 11:

Saturated solution of ceric ammonium nitrate in l N hydrochloric acid EXAMPLE 13 Transfer coating:

33.0 percent by weight polyethylene glycol, molecular weight average 6000 (Carbowax 6000) 33.0 percent by weight polyethylene glycol, molecular weight average 1500 (Carbowax 1500) 34.0 percent by weight alpha benzil dioxime EXAMPLE l4 Fluid for use with composition of Example 13:

15 percent solution of copper sulphate in 28 percent solution of ammonium hydroxide EXAMPLE 15 Transfer coating:

33.0 percent by weight polyethylene glycol, molecular weight average 6000 (Carbowax 6000) 33.0 percent by weight polyethylene glycol, molecular weight average 1500 (Carbowax 1500) 34.0 percent by weight phloroglucinol EXAMPLE l6 Fluid for master imaged with composition of Example 15:

80.0 percent by weight water 20.0 percent by weight ferric nitrate EXAMPLE 17 Transfer coating:

33.0 percentby weight polyethylene glycol, molecularweight average 6000 (Carbowax 6000) 33.0 percent by weight polyethylene glycol, molecular weight average 1500 (Carbowax 1500) 34.0 percent by weight Fe(NH )(SO EXAMPLE 18 I Fluid for master imaged with composition'o'f Ex ample 17:

Saturated alcoholic solution of 8-hydroxyquinoline EXAMPLE 19 Transfer coating:

30.0 percent by weight polyethylene glycol, molecular weight average 6000 (Carbowax 6000) 60.0 percent by weight polyethylene. glycol, molecular weight average 1500 (Carbowax 15.00) 10.0 percent by weight beryllium chloride EXAMPLE 20 Fluid for transfer coating of Example 19:

Saturated alcoholic solution of quinalizarin EXAMPLE 21 Transfer coating:

11.0 percent by weight carnauba wax 15.0 percent by weight cardis wax 15.0 percent by weight mineral oil heavy 13.0 percent by weight mineral oil light 1.5 percent by weight sodium oleate 55.5 percent by weight nickel acetate EXAMPLE 22 Fluid for use with master imaged with composition of Example 21:

12.0 percent by weight diethanolamine 3.0 percent by weight ethyl cellosolve 10.0 percent by weight distilled water 74.0 percent by weight methanol 1.0 percent by weight potassium dithiooxalate Instead of potassium dithiooxalate which gives red copy, use may be made of corresponding amounts of thiosalicylic acid (brownish violet), p-dimethylaminobenzylidene (brownish red) or dithiooxamide (bluish black) copy.

The transfer coatings may be applied by hot melt or solutions or from dispersions as previously described.

It will be further understood that the concepts of this invention are not limited to the use of the reactive component in a transfer coating employed in the manufacture of an imaged master but that the concepts may be practiced by the use of imaging materials of the type described in the form of typewriter ribbons, writing inks, drawing crayons or the like embodying one or more of the substantially colorless reactive components of the type described in preparation of the imaged master with the other component for completing the reaction to form the colored reaction product in the fluid or in the copy sheet for reaction to develop the copy as an incidence to the transfer of the one component from the imaged master to the copy sheet. The compositions of such inking materails or crayons or typewriter ribbons may be formulated with a conventional base containing the reactive component in relatively high concentrations.

It will be apparent from this description that a completely new and improved duplicating process is provided herein capable of use in conventional hectograph duplicating machines or in conventional spirit duplicating machines to produce copy of improved quality without fear of set-off and without fear of dirtiness caused by discoloration by the various materials involved. Until the reaction product is formed in the copy sheets, the elements involved in the preparation of the master, in the manufacture of the imaging compositions and in the elements present in the materials used to produce the imaged master or in the imaged master itself remain wholly free of any color transfer value and therefore avoids dirtiness which is the most objectionable feature of processes which have heretofore been employed. It will be evident that the imaging material in the transfer sheet, master sheet or in other imaging compositions is free of any color and may be handled in a normal manner without staining or dirtying ones hands or clothing and equipment and the imaged master may be filed away for subsequent use to obtain additional copies without loss of definition or quality of the copy produced.

It will be understood that changes may be made in the details of the compositions, their formulations and their arrangement and method of use without departing from the spirit of the invention, especially as defined in the following claims.

I claim:

1. A transfer sheet for use in the preparation of an imaged duplicating master from which multiple copies can be produced comprising a base sheet and a composition, the major proportion of which exists as a continuous transfer coating concentrated on the surface of the base sheet to permit substantially complete displacement therefrom in selected areas, said composition containing a high concentration of nickel acetate and dithiooxamide and a wax carrier in which the dithiooxamide and nickel acetate are insoluble and in which the nickel acetate and dithiooxamide are present as dispersed phases in the wax matrix dispersed as separate ingredients in the coating.

2. The method of producing multiple copies by a duplicating process using a master imaged with a material containing a large proportion of a water and alcohol soluble salt of a polyvalent metal capable of reaction with a sulfide ion to form a highly colored polyvalent metal sulfide and a water and alcohol soluble organic thio compound capable of releasing sulfide ions from solution in a medium selected from the group consisting of alcohol and water and wherein the materials are dispersed as separate components in a wax matrix in which both of the compounds are insoluble, comprising contacting the imaged surface of the master with copy sheets wetted with a fluid which is a solvent for the sulphur containing compound and the metal salt whereby some of each of the compounds is leached for transfer from the imaged master to the copy sheets while in solution whereby reaction can take place to form the colored reaction product in the copy sheets.

3. The method of producing by a duplicating process using a master imaged with a material containing a large proportion of dithiooxamide and nickel acetate, dispersed as separate components in a wax carrier in which both of the materials are insoluble, comprising contacting the imaged surface of the master with copy sheets previously wetted with a fluid which is a solvent for the dithiooxamide and nickel acetate and which contains alkali in solution whereby some of the dithiooxamide and nickel acetate is leached for transfer from the imaged master to the copy sheets where reaction takes place to form the colored reaction product.

References Cited in the file of this patent UNITED STATES PATENTS 823,691 Ligon June 19, 1906 1,050,236 Schmitt Jan. 14, 1913 1,917,370 Hickmann July 11, 1933 2,038,486 Glas Apr. 21, 1936 2,073,033 Szasz Mar. 9, 1937 2,146,976 Neidich Feb. 14, 1939 2,168,098 Groak Aug. 1, 1939 2,217,349 Neidich Oct. 8, 1940 2,316,340 Kohn Apr. 13, 1943 2,663,656 Miller et al. Dec. 22, 1953 2,748,024 Klimkowski et al. May 29, 1956 2,755,200 Balon et al. July 17, 1956 2,936,707 Maguire et al. May 17, 1960