US3216350A

US3216350A - Duplicating process and products

Info

Publication number: US3216350A
Application number: US384305A
Authority: US
Inventors: Sharkey Melvin
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-07-22
Filing date: 1964-07-22
Publication date: 1965-11-09
Anticipated expiration: 1982-11-09
Also published as: DE1282031B; GB1065507A

Description

Nov. 9, 1965 M. SHARKEY 3,216,350

DUPLICATING PROCESS AND PRODUCTS Filed July 22, 1964 INVENTOR Melvin Sharke y MQQHZM HT roe/v.5 Y5

3,216,350 DUPLICATING PRQCESS AND PRGDUCTS Melvin Sharkey, 1614 Hereford Road, Hewlett, N.Y. Filed July 22, 1964, Ser. No. 384,305 12 (Zlaims. (Cl. fill-149.4)

The present invention relates to a novel dry hectograph duplicating process and to the imaged master sheets for use in such process.

In the conventional spirit hectograph duplicating process, dye images are typed or drawn onto a master sheet and these images are duplicated onto copy sheets which have been wetted with volatile dye solvent such as ethanol, the solvent dissolving dye from the images onto the copy sheet prior to its evaporation.

While the spirit process enjoys widespread commercial success, it has at least one great disadvantage which prohibits its use for certain applications such as for the production of copies of patterns used in the garment industry. The spirits used in the spirit duplicating process are very volatile and combustible and therefore present a fire and explosion hazard which prevents their use in areas where prohibited by fire laws.

A number of dry hectograph processes have been proposed in an effort to eliminate the necessity of using volatile spirits. Most of these methods employ non-volatile dye-solvent coatings on the copy sheets so that when master images are pressed thereagainst, portions of the master images are transferred to the copy sheet coating and gradually dissolved therein. Such a process, such as taught by U.S. Patent No. 3,034,428, has the disadvantages that dissolution and development of the dye color on the copy sheet is slow and uncontrollable since a mass of dye is pressure-transferred to the copy sheet and the copy sheet coating continues to dissolve the dye into areas States Patent adjacent to the areas which actually support the dye images so that broadening and blurring of the images results.

However, equally objectionable is the fact that the specially-coated copy sheets are expensive and this expense, when added to the expense of providing conventional master paper which is also costly, makes the process prohibitive for a large-scale web-copy operation as is used in the pattern-copying field.

A dry copy process has been proposed in U.S. Patent No. 2,501,495 which employs conventional copy paper. According to this process, dye images are typed upon the resinous coating on a master sheet and the images are then pressed against a copy sheet while the master is cooled and the cop-y sheet is heated. This process is rather tedious due to the necessity of closely controlling the temperature of a cooling roll and a heating roll in close proximity, but more importantly this process is not a hectograph or dye-dissolving process but depends upon the mass transfer of portions of the master images to each copy sheet. Undissolved dyestulf is so easily smudged and has such a tremendous staining power that the copies imaged by this process cannot be handled without blurring the images and staining the hands and clothing. This makes such copies useless in the pattern field where staining of the fabric being cut cannot be tolerated.

With these problems and disadvantages of the prior art in mind, it is an object of the present invention to provide a novel dry hectograph copying process in which dye images can be dissolved onto conventional copy papers without the use of volatile spirits and without the necessity and expense of using specially-coated copy sheets.

It is another object of this invention to provide imaged hectograph master sheets which are dry-to-the-touch but which are activated by means of heat to provide sufii- 'ice cient non-volatile dye solvent to dissolve the dyestulf in the master images so that it can be transferred in developed, dissolved form to a copy sheet under the elfects of even slight pressure.

It is still another object of the invention to provide imaged hectograph master sheets which can be used periodically for the production of duplicate copies by means of heat alone and which revert to dry, stable form upon cooling after each use.

These and other objects and advantages are accomplished according to this invention in a manner which will be clear to those skilled in the art in the light of the present disclosure including the drawing, in which:

FIGURE 1 is a diagrammatic cross-section, to an enlarged scale, of an imaged hectograph master sheet according to the present invention.

FIG. 2 is a sectional view showing an arrangement of a master-carrying drum, a master sheet heating system and a pressure roll included in an apparatus suitable for carrying out the process used herein for duplicating and transferring hectograph images from a master sheet to successive copy sheets.

FIG. 3 is a sectional view of an arrangement of a continuous master sheet and a continuous copy sheet, as used in the pattern making art.

The objects and advantages of the present invention are accomplished by providing as a master sheet a paper foundation having thereon a heat-meltable coating comprising at least a major amount by weight of one or more heat-meltable materials which, in their melted state, are solvents for the dyestulf in the images placed upon the master sheet coating. The imaged master sheet is dry and may be handled and stored until copies of the imaged subject matter are desired. At such time, as many copies as desired may be produced on plain copy paper by merely heating the master sheet to melt the coating thereon and bringing the heated master sheet into pressure contact with a succession of copy sheets.

The mode of operation of the present master sheets is not completely understood although it appears that the dissolving of the master images is brought about mainly by a spreading of the melted solvent coating over the images when the master is placed in pressure contact with each copy sheet. This provides a fresh supply of dissolved dyestulf for each copy sheet and brings about a slow metering of the dyestuff from the master sheet to the succession of copy sheets.

Referring to the drawing, FIG. 1 illustrates a master sheet 10 having a paper foundation 11 carrying a heatmeltable dye-solvent layer 12 and dye-containing images 13. The nature of the heat-meltable dye-solvent layer 12 forms a critical part of the present invention. This layer must be non-pressure-transferable and therefore is applied as a relatively thin layer most of which is present in the form of an impregnation of the paper foundation. Because of the differences in the absorbency of papers of different types, it is impossible to place a limitation on the amount of dye-solvent coating to be applied. However, it is clearly within the skill of the artisan to apply the dye-solvent compositions in such amounts that the entire surface of the paper sheet is filled and smoothed to produce a continuous coating which is not sufficiently thick to be pressure-transferable.

The dye-solvent coating compositions of this invention preferably consist of one or more solid materials which are dye solvents in their melted state and which melt at a temperature within the range of from about F. to about 250 F. and preferably within the range of from F. to about F. Materials found suitable for this purpose include solid fatty alcohols such as cetyl, myristyl and stearyl alcohols; solid fatty acids such as stearic, palmitic, lauric and capric; solid esters of various glycols and organic acids, and solid glycol ethers such as polyethyleneand polypropylene-glycol ethers. It has also been found possible to use higher melting point solid dye solvents or lower melting point solid or liquid dye solvents provided that they are used in admixture with other solid dye solvents to provide a composition having a melting point between 80 F. and 250 F.

The aforementioned dye solvents, either alone or in admixture with small amounts of low melting point wax binder materials such as beeswax, mineral wax or the like, are coated onto a paper web to form a thin, smooth, continuous coating thereon. The coating must be substantially non-pressure-transferable and while it is difiicult to give a suitable range of coating weights due to the differences in absorptivity of different paper stocks, in general the coating is applied in a weight ranging between 2 and 7 pound per ream (25" x 38" x 500 sheets).

The prepared master web is used in web form for the production of large copies such as garment patterns or may be reduced to sheet lengths. The master is imaged on the dye-solvent coating in conventional manner by superposing the master and a hectograph transfer sheet, the transfer layer being against the dye-solvent coating, and applying imaging pressure against the back of the master sheet to transfer mirror-reverse images to the dye-solvent coating. The hectograph composition of the transfer sheet must have a higher melting point than the dye-solvent coating.

The imaged master sheet may then be used .to form duplicate copies by placing the imaged side of the master against any copy paper, applying sufiicient pressure to insure overall contact, and applying heat such as by a heated pressure means such as a heated iron, a hot plate, a heated drum or roller, or by infrared radiation or the like, whereby the dye-solvent coating becomes melted and penetrates, surrounds and envelops the unmelted master images and dissolves the dyestuff therein whereby the dissolved dyestuff stains the copy sheet to form thereon dissolved dye images corresponding to the master images.

If desired, the imaged master sheet may be heated before it is contacted with the copy sheet, provided that contact is made while the dye-solvent coating is still in the melted state. Also in cases where it is desired to use infrared radiation as the heating means, it is preferred that the master paper he pigmented dark and/ or that the copy paper have a dark coating on the back side so that it will absorb the infrared radiation and convert it to heat. The dye-solvent coating should not be pigmented a dark color but rather should be clear or translucent or pigmented a light color such as white to correspond with the color of the copy sheet so as not to be noticeable if melted portions thereof transfer to the copy sheet during the duplicating process.

Any suitable apparatus may be used for the present duplicating process provided that it includes heating means to heat the master sheet between 80 F. and 250 F. to melt the dye-solvent coating, and pressure means to force the heated master into intimate surface contact with the copy sheet.

The device illustrated by FIG. 2 comprises a heated drum 20 having mounted thereon the imaged master sheet 10 and a pressure roller 30 urged against the heated drum. Drum is internally heated by means of electrical heating means 21 to provide a temperature at the surface of the drum sufiiciently high to melt the coating on the master sheet. If desired, external heating means such as infrared radiation lamp 22 may be used as a supplement to or in place of the internal heating means 21. Copies are made by urging a copy sheet 15 between the drum and the pressure roller whereby the dissolved dyestuif in the master images 13 stains the surface of the copy sheet to form duplicate images thereon. These duplicate images have an instant color since they consist of dissolved dyestuff, and they are substantially nonsmearing and clean-to-the-touch since they are free of undissolved dyestuff or wax.

The embodiment illustrated by FIG. 3 of the drawing pertains to continuous web copying whereby a continuous imaged master sheet 10 from supply roll 41 and a continuous copy sheet 15 from supply roll 51 are urged into pressure contact between roller 25 and pressure roller 30 to effect the duplicating step after which the master sheet is wound on take-up roll 42 and the imaged copy sheet carrying dye images 14 is wound on take-up roll 52. The heating of the master sheet prior to contact with the copy sheet is accomplished by infrared radiation lamps 22 and, if desired, by internal heating means in roller 25.

It is a critical feature of the present invention that the hectograph dyestuff images 13 on the master sheet must be non-meltable at the temperature used to effect the present duplicating process since melting of the master images would permit a melting-over or mass transfer to the copy sheet so that the images formed thereon would contain undissolved dyestufl and wax binder material and would be easily smudged and very dirty-to-the-touch. In other Words, if the master images are melted at the temperatures employed, then the transfer would consist of solid rather than dissolved dyestuif and the formed copy would itself be useful as a master sheet.

Any conventional hectograph transfer sheet may be used to image the present master sheets provided that the hectograph composition has a higher melting point than the temperature used to melt the dye-solvent layer in the duplicating operation. Most wax-base hectograph compositions melt above F. and are well suited for use according to the present invention. Lower melting wax-base compositions may be used provided that very low melting point dye-solvent coatings are used and the temperature used in the duplicating operation is between the melting point of the coating and the melting point of the images.

If desired, higher melting point solvent-applied hectograph compositions based upon film-forming binder materials such as cellulose plastics, vinyl resins and hydrophilic colloids may be used in place of hot melt wax compositions. Such compositions have a melting point Well in excess of 250 F.

In most cases it has been found preferable to use hectograph transfer sheets on which the transfer layer has a low caliper or thickness in the area of from 2 to 6 points (0.0002 to 0.0006 inch or 0.2 to 0.6 mil) since such thin layers deposit thin master images on the master sheet. Since the image dissolution on the master sheet appears to be the result of the melted dye solvent spreading over the master images, then it is preferred to maintain the dye-solvent coating and the height of the master images on as equal a plane as possible. It has been found that thin hectograph layers are preferred and that the height of images placed with such thin layers is nearly on an equal plane With the surface of the dyesolvent coating due to embossing and/or displacement of the dye-solvent coating in the impressed areas.

In cases where the melting of the dye-solvent coating is effected by means of infrared radiation lamps, the master images should consist of a hectograph composition which absorbs little, if any, of the radiation. Most conventional hectograph compositions and dyestuffs are suitable in this regard.

It should be understood that melting of the coating on the master sheet may be effected in any number of ways other than by applying heat directly to the master sheet. For instance the copy sheet may be heated before or during its contact with the master whereby heat is transferred to the master to cause the melting of its coating. Also the process may be carried out in a heated atmosphere such as an oven whereby the copy sheet, master sheet and master images are heated to the same extent.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. The process of duplicating master images onto a succession of copy sheets which comprises the steps of:

(a) forming a master sheet by applying to a paper foundation sheet a thin solid coating which is substantially non-pressure-transferable and which comprises at least one solid solvent material which, in its melted state, is a solvent for a hectograph dyestutf,

(b) applying over said solid coating images which contain an undissolved hectograph dyestutf which is soluble in the melted solvent material of the coating, said images having a melting temperature higher than the melting temperature of the said solid coating, and

(c) heating the imaged master sheet to a temperature sufiiciently high to melt the solid coating without melting the images, and

(d) pressing the heated master sheet against a succession of copy sheets whereby the melted solvent material dissolves a portion of the hectograph dyestufi onto each copy sheet surface to stain each copy sheet surface pressed thereagainst to form dissolved dyestuif images on the copy sheets in areas correspond ing to the imaged areas of the master sheet.

2. The process according to claim 1 in which the coating on the master sheet has a melting point within the range of from about 80 F. to about 250 F., the images thereon have a higher melting point, and sufiicient heat is applied to create a temperature of between about 80 F. and 250 F. in the coating of the master sheet to melt the coating without melting the images thereon.

3. The process according to claim 1 in which the solvent material comprises at least one material selected from the group consisting of fatty acids, fatty alcohols, solid esters and solid ethers.

4. The process according to claim 1 in which the images which contain undissolved dyestuff include a binder material selected from the group consisting of wax and film-forming binder materials.

5. The process of duplicating master images onto a succession of copy sheets which comprises the steps of:

(a) forming a master sheet by applying to an infrared radiation-absorbing paper foundation sheet a thin solid coating which has a melting temperature in the range of 80 F. to 250 F., which is substantially non-pressure-t-ransferable and which comprises at least one solid solvent material which, in its melted state, is a solvent for a hectograph dyestuif,

(b) applying over said solid coating images which contain an undissolved hectograph dyestulf which is soluble in the melted solvent material of the coating and which does not absorb infrared radiation, said images having a melting temperature higher than the melting temperature of the said solid coating, and

(c) applying infrared radiation to heat the imaged master sheet to a temperature sufficiently high to melt the solid coating without melting the images, and

(d) pressing the heated master sheet against a succession of copy sheets whereby the melted solvent material dissolves a portion of the hectograph dyestuff onto each copy sheet surface to stain each copy sheet surface pressed thereagainst to form dissolved dyestuff images on the copy sheets in areas corresponding to the imaged areas of the master sheet.

6. The process of duplicating master images onto a succession of copy sheets which comprises the steps of:

(a) forming a master sheet by applying to a paper foundation a thin solid coating which has a melting temperature in the range of 90 F. to 160 R, which is substantially non-pressure-transferable and which comprises at least one solid solvent material which, in

6 its melted state, is a solvent for a hectograph dyestufl",

(c) superposing the imaged master sheet with its images in surface contact with a succession of copy sheets, and

(d) applying a heated pressure means against the master sheet to press the master sheet into intimate surface contact with each copy sheet and melt the coating on the master sheet without melting the images thereon whereby the melted solvent material dissolves a portion of the hectograph dyestuff onto each copy sheet surface to stain each copy sheet surface pressed thereagainst to form dissolved dyestutf images on the copy sheets in areas corresponding to the imaged areas of the master sheet.

7. The process of duplicating master images onto a succession of copy sheets which comprises the steps of:

(a) forming a master sheet by applying to a paper foundation a solid coating having a weight of between about 2 and 7 pounds per ream and having a melting temperature in the range of F. to 250 E, which is substantially non-pressure-transferable and which comprises at least one solid solvent material which, in its melted state, is a solvent for a hectograph dyestuff and which is selected from the group consisting of fatty acids, fatty alcohols, solid esters and solid ethers,

(b) applying over said solid coating on the master sheet images which contain a hectograph dyestuff which is soluble in the melted solvent material of the coating, said images having a melting temperature higher than the melting temperature of the said solid coating, and

(d) pressing the heated master sheet against a succession of copy sheets whereby the melted solvent material dissolves a portion of the hectograph dyestufi onto each copy sheet surface to stain each copy sheet surface pressed thereagainst to form dissolved dyestutf images on the copy sheets in areas corresponding to the imaged areas of the master sheet.

8. A hectograph master sheet carrying undissolved dyestuif images and adapted for the placement of duplicate dissolved dyestuif images on a conventional copy sheet by means of heat and in the absence of spirit duplicating fluids, which comprises a paper foundation sheet having thereon a thin solid coating which is substantially nonpressure-transferable and which contains at least one solid solvent material which, in its melted state, is a solvent for hectograph dyestuff, and having on said thin solid coating at least one image comprising hectograph composition having a higher melting temperature than the melting temperature of the said thin solid coating and containing undissolved hectograph dyestuif which is soluble in the melted solvent material of said coating.

9. A hectograph master sheet according to claim 8 in which the solvent material comprises at least one material selected from the group consisting of fatty acids, fatty alcohols, solid esters and solid ethers.

10. A hectograph master sheet according to claim 8 in which the hectograph composition includes a binder material selected from the group consisting of wax and film-forming binder materials.

11. A hectograph master sheet carrying undissolved dyestutf images and adapted for the placement of duplicate dissolved dyestuff images on a conventional copy sheet by means of heat and in the absence of spirit duplicating fluids, which comprises an infrared radiationabsorbing paper foundation sheet having thereon a thin solid coating which is substantially non-pressure-transferable and which has a meltingtemperature within the range of 90 F. to 160 F. and which contains at least one solid solvent material which, in its melted state, is a solvent for hectograph dyestuff, and having on said thin solid coating at least one image comprising hectograph composition which does not absorb infrared radiation and which has a higher melting temperature than the melting temperature of the said thin solid coating and contains undissolved hectograph dyestufi which is soluble in the melted solvent material of said coating.

12. A hectograph master sheet carrying undissolved dyestufl images and adapted for the placement of duplicate dissolved dyestuif images on a conventional copy sheet by means of heat and in the absence of spirit duplicating fluids, which comprises a paper foundation sheet having thereon a solid coating which is substantially non-pressure-transferable and which has a Weight of between about 2 and 7 pounds per ream and a melting temperature within the range of 90 F. to 160 F. and which contains at least one solid solvent material which, in its melted state, is a solvent for hectograph dyestuif, and having on said solid coating at least one image comprising hectograph composition having a higher melting temperature than the melting temperature of the said solid coating and containing undissolved hectograph dyestuff, which is soluble. in the melted solvent material of said coating.

References Cited by the Examiner UNITED STATES PATENTS 2,163,934 6/39 Collins 101-149.4 2,501,495 3/50 Carroll et a1. 101 -1495 2,862,832 12/58 Shepherd 117-32 ROBERT E. PULFREY, Primary Examiner.

DAVID KLEIN, Examiner.

Claims

1. THE PROCESS FOR DUPLICATING MASTER IMAGES ONTO A SUCCESSION OF COPY SHEETS WHICH COMPRISES THE STEPS OF: (A) FORMING A MASTER SHEETS BY APPLYING TO A PAPER FOUNDATION SHEET A THIN SOLID COATING WHICH IS SUBSTANTIALLY NON-PRESSURE-TRANSFERABLE AND WHICH COMPRISES AT LEAST ONE SOLID SOLVENT MATERIAL WHICH, IN ITS MELTED STATE, IS A SOLVENT FOR A HECTOGRAPH DYESTUFF, (B) APPLYING OVER SAID SOLID COATING IMAGES WHICH CONTAIN AN UNDISSOLVED HECTOGRAPH DYSTUFF WHICH IS SOLUBLE IN THE MELTED SOLVENT MATERIAL OF THE COATING, SAID IMAGES HAVING A MELTING TEMPERATURE HIGHER THAN THE MELTING TEMPERATURE OF THE SAID SOLID COATING, AND (C) HEATING THE IMAGED MASTER SHEET TO A TEMPERATURE SUFFICIENTLY HIGH TO MELT THE SOLID COATING WITHOUT MELTING THE IMAGES, AND (D) PRESSING THE HEATED MASTER SHEET AGAINST A SUCCESSION OF COPY SHEETS WHEREBY THE MELTED SOLVENT MATERIAL DISSOLVES A PORTION OF THE HECTOGRAPH DYESTUFF ONTO EACH COPY SHEET SURFACE TO STRAIN EACH COPY SHEET SURFACE PRESSED THEREAGAINST TO FORM DISSOLVED DYESTUFF IMAGES ON THE COPY SHEETS IN AREAS CORRESPONDING TO THE IMAGED AREAS OF THE MASTER SHEET.

8. A HECTOGRAPH MASTER SHEET CARRYING UNDISSOLVED DYESTUFF IMAGES AND ADAPTED FOR THE PLACEMENT OF DUPLICATE DISSOLVED DYSTUFF IMAGES ON A CONVENTIONAL COPY SHEET BY MEANS OF HEAT AND IN THE ABSENCE OF SPIRIT DUPLICATING FLUIDS, WHICH COMPRISES A PAPER FOUNDATION SHEET HAVING THEREON A THIN SOLID COATING WHICH IS SUBSTANTIALLY NONPRESSURE-TRANSFERABLE AND WHICH CONTAINS AT LEAST ONE SOLID SOLVENT MATERIAL WHICH, IN ITS MELTED STATE, IS A SOLVENT FOR HECTOGRAPH DYESTUFF, AND HAVING ON SAID THID SOLID COATING AT LEAST ONE IMAGE COMPRISING HECTOGRAPH COMPOSITION HAVING A HIGHER MELTING TEMPERATURE THAN THE MELTING TEMPERATURE OF THE SAID THIN SOLID COATING AND CONTAINING UNDISSOLVED HECTOGRAPH DYSTUFF WHICH IS SOLUBLE IS THE MELTED SOLVENT MATERIAL OF SAID COATING.