US3563738A - Copying process and materials - Google Patents

Abstract

A PHOTOCOPYING AND REPRODUCTION MATERIAL USEFUL IN COPYING VARIOUS COLORS IS PROVIDED BY COMBINING A FIRST COMPONENT WHICH IS THERMALLY ACTIVATABLE TO A TACKY SUPER-COOLED STATE WITH A SECOND LIGHT-SENSITIVE COMPONENT WHICH, WHEN EXPOSED TO ACTINIC RADIATION, CHANGES THE HEAT-ACTIVATABILITY AND THERMAL PROPERTIES OF THE FIRST COMPONENT. ACTINIC EXPOSURE AND HEATING IN COMBINATION WITH THE APPLICATION OF CONTRASTING DUST DEVELOPMENT PROVIDES CLEAR COPIES OF ORIGINAL GRAPHICS. THE MATERIALS ARE USEFUL ALSO IN THE PRODUCTION OF MULTIPLE COPIES.

Description

United States Patent 3,563,738 COPYING PROCESS AND MATERIALS Kohei Itano, Hachioji-shi, Masashi Nakano, Nishitamagun, Shoichiro Hoshino, Narimune, and Akira Kato, Hachioji-shi, Japan, assignors to Keuffel & Esser Company, Hoboken, N.J., a corporation of New Jersey No Drawing. Filed Oct. 16, 1967, Ser. No. 675,317 Claims priority, application Japan, Oct. 18, 1966, 41/ 68,252 Int. Cl. G03c 11/12 US. CI. 96-28 Claims ABSTRACT OF THE DISCLOSURE A photocopying and reproduction material useful in copying various colors is provided by combining a first component which is thermally activatable to a tacky super-cooled state with a second light-sensitive component which, when exposed to actinic radiation, changes the heat-activatability and thermal properties of the first component. Actinic exposure and heating in combination with the application of contrasting dust development provides clear copies of original graphics. The materials are useful also in the production of multiple copies.

BACKGROUND OF THE INVENTION Heretofore, a variety of copying processes have been known. Among these, there are copying processes using a copying material comprising 2 kinds of chemicals which, when heated, react with each other to form a visible image (U.S. Patent 2,663,654), and copying processes using a copying material comprising a substance which has such characteristics that it fuses or vaporizes when subjected to heating (momentary heating) and possesses dust-adhering property even after cooling (a thermally transferable substance capable of maintaining supercooled state) (Japanese patent publication No. 2,432/66).

However, the copying materials employed in the abovementioned copying processes are useful for the copying of IR-absorbing originals, but not for the copying of colored originals.

SUMMARY OF THE INVENTION The copying process of the present invention uses a novel copying material containing a thermally activatable and transferable component which fuses or vaporizes on heating and maintains for a while, even after cooling, a quasi-stable dust adhering tacky state, and a photoactive component which, when subjected to irradiation with actinic light, is activated and reacts with said thermally transferable component to reduce the heat sensitivity of said component. In the present invention, said novel copying material is subjected to local exposure (image-wise exposure corresponding to an original) to reduce the heat sensitivity of the background area and is then heated after placing a receptor sheet thereon. When the copying material is heated in such a state as above, only the area corresponding to the image portion fuses or vaporizes, and the thermally transferable component is transferred onto the receptor sheet. Subsequently, the receptor sheet is peeled off and is developed with a toner, whereby the image is made visible to obtain a copy. The present invention gives such advantages that not only many copies "ice can be prepared from one copying material but also the thus obtained copies are excellent in quality and stable.

The present invention will be explained in detail below.

The copying material employed in the present invention is entirely novel as mentioned above and is composed of the components as shown hereunder.

As the first component of the present copying material, a thermally transferable component is employed which is a normally hard, non-tacky solid having such properties that it can fuse or vaporize when heated at a temperature of 180 C. for a short period of time, and that even when cooled after heating, it can maintain, for a while, a quasi-stable fluidable state, i.e. a fused or vaporized state, and can transfer, onto another sheet, in a trace amount in a state having stickiness (hereinafter referred to as super-cooled state). In addition to the above-mentioned properties the first component has such properties that when exposed to light in the presence of such a photo-active component as mentioned later, it reacts with said photo-active component to be greatly reduced in, or entirely deprived of, its fusibility or vaporizability.

Since there was obtained no chemical literature showing data which are suitable for clarifying substances usable as the first components, it was necessary to establish the definite test method described below.

According to this method, there is first selected a substance capable of forming a dust adhering latent image on a receptor sheet, when the following procedures are followed:

The substance is coated in a small amount on a base such as paper, film or glass, the receptor sheet is placed on the coated base, the composite is heated to a temperature of 70180 C., and then the receptor sheet is peeled off from the base to reveal a dust-adhering substance. In a counter-test the selected substance is mixed with one of the photoactive components mentioned later, e.g. tribromornethylphenylsulfone and the mixture is coated on such a base as mentioned above and is exposed to actinic Acetanilide,

Benzotriazole, O-toluenesulfonamide, N-ethyl-N-benzyl-2,S-diethoxyaniline, Cinnamylidene-benzophenone, 4-hydroxycalcon, Dicinnamoyl, 2,6-dimethoxydiphenyl, Cinnamylideneacetophenone, 1-phenyl-3-pyrazolidone, 1-m-tolyl-3-pyrazolidone, l-O-tolyl-3-pyrazolidone, 5-phenyl-3-pyrazolidone, Tribenzylamine, 2,4-dihydroxybenzophenone.

As the second component of the present copying material, a photo-active component is contained. Essentially, a substance effective as the photo-active component is such that when exposed to near-ultraviolet light of 30004000 A., it is activated and reacts with the above-mentioned thermally transferable component to reduce the heat sensitivity of said component. That is, the photo-active component may be any of a number of substances which not only destroy the supercooled state of the thermally transferable component but also make said component difiicultly fusible and vaporizable.

Particularly effective as such photo-active components are compounds represented by the general formula wherein R is a halogen atom, a substituted or unsubstituted alkyl, aralkyl, aryl, aroyl or heterocyclic radical or a radical represented by RSO or RSO-, where R is same in the case of R and R R and R are individually a hydrogen, chlorine, bromine or iodine atom, and R R and R are not hydrogen atoms at a same time.

Typical as the compounds repersented by the above general formula are as exemplied below.

Tetrabromocarbon,

Pentabromoethane,

Bromoform,

Iodoform, l,1,l-trichloro-2-methyl-2-propanol, 2,2,2-tribromoethanol-dichlorobromoethane, a,a,a-Tribromotoluene, a,u,a-a',u,a-Hexabromo-m-xylene, Trichloroacetamide,

Hydrated chloral,

Hydrated bromal, w,w,w-Tribromoquinaldine, Tribromomethylphenylsulfone Trichloromethylphenylsulfone, 2,5-dimethyl-w,w,w-tribromoacetophenone.

These photo-active components decompose or sublime on heating.

The copying material employed in the present invention is prepared by forming the above-mentioned two components into a solution together with a film-forming high molecular weight substance (binder) and applying the solution onto a suitable support such as paper or film base, followed by drying.

The high molecular weight binders to be used in the above case include, for example, celluloses such as acetyl cellulose, acetylbutyl cellulose and ethyl cellulose, vinyl compounds such as vinyl chloride, vinyl acetate, vinyl acrylate and copolymers thereof, styrene-maleic acid copolymers, and synthetic rubbers such as cyclized rubbers, acrylic rubbers and butadiene rubbers.

By incorporation of a suitable sensitizer, the copying material of the persent invention can not only be broadened in sensible wave length range but can be increased in photosensitivity. That is, when a sensitizer is incorporated, the copying material comes to be sensitive to light having a wave length within a range of 3000-6000 A., and therefore copying can be carried out by application of not only ultraviolet light but also a visible light. For example, not only through copying using ultraviolet light but also reflex copying using a visible light (sunlight) can be effected and the copying of multi-color originals can be easily carried out.

Such sensitizers are classified into two kinds; so called color sensitizers and chemical sensitizers.

Effective as the sensitizers belonging to the former are various photosensitive dyes employed in the silver halide photography such as acridine dyes, cyanine dyes, merocyanine dyes and styryl type dyes.

Typical as such sensitizers are, for example, as follows:

Acridine Orange,

Acridine Red,

Rose Bengale,

Eosine,

Erythrocin Methylene Blue,

Pinakryptol yellow,

Pinacyanol,

1- 3-ethyl-2(H) -benzothiazolidene] -4-butylidene dibenzothiazolylmethane,

[1-ethyl-4(1H)-quinolidene]-ethylidene-di-2- benzothiazolylmethane,

5-2- 3-ethylbenzoxazolidene) -ethylidene-Z-phenylimide- 3-phenyl-4-keto-tetrahydrothiazole,

1,3-diethylthio-4-carbocyanine iodide,

1,3-dirnethyloxa-2'-carbocyanine-p-toluenesulfonate,

5-[l-methyl-2(1H)-quinolidene]-2-butylidene-3- ethyl-2-thio-2,4-oxazolidenedione.

Typical as the sensitizers belonging to the latter are, for example, as follows:

Aldehydes such as benzaldehyde, p-dimethylamino-benzaldehyde, o-phthalaldehyde, o-phthalaldehydic acid and phenylacetaldehyde.

Quinones such as 1,2-benzanthraquinone, 1,4-dichloroanthraquinone and l-chloroanthraquinone.

Heterocyclic N-oxide compounds such as 2,4-dimethylquinoline-N-oxide and quinaldine-N-oxide.

Quaternary compounds of N-oxides such as N-methoxy- 2,5-dimethylpyridinium iodide, N,N-O-xylene-oxyl-bis-2- methylquinolinium bromide.

When these sensitizers are suitably used, the sensitivity can be increased more than tenfold, and the copying materials come to show a sensitivity many-fold higher than the sensitivity of commercial diazo copying papers.

The copying materials employed in the present invention are prepared by dissolving or dispersing the abovementioned constituents in a binder solution and applying the solution or dispersion onto a suitable support according to a known procedure.

In this case, preferable quantitative proportions of individual constituents are as follows:

Parts Solvent 500-1000 Film-forming binder 20l00 Thermally transferable component l5 Photo-active component 5-50 Sensitizer (optional) 0.1-5

(Provided, the amount of binder is at most 10% based on the amount of solvent.)

Usable volatile solvents, in addition to water, are alcohols such as ethanol, methanol and propanol, ketones such as acetone and methylethylketone, aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as hexane and ligroin, halogenated hydrocarbons such as methylene chloride and trichlene, tetrahydrofuran, dimethylformamide and cyclohexane. It is, however, needless to say that suitable solvents should be selected considering safety, drying rate, solvent capability and the like.

The constituents as mentioned above are not only used in a completely dissolved state but also may be applied in an undissolved state. Alternatively, they may be formed into fine particles and rubbed into an original paper (support) or may be incorporated in a paper material at the time of making the original paper.

It is to be suggested that in preparing the sensitized copying material of the present invention the operations be effected under a yellow or red safety lamp and that the drying be carried out at a temperature below C.

As the support, any of plastic film bases, glass sheets or metal plates may be used. Generally, however, the use 5 of a transparent or translucent thin paper or plastic film base makes it possible to obtain a clear image excellent in resolution and high in density. Further, the amount of liquid to be coated on the support is preferably 13,u. in thickness.

When the thus prepared copying material is subjected to image-wise exposure corresponding to an original, an invisible latent image is immediately formed. This latent image is heated, by use of a heating means such as an infrared lamp or heating roll, to a temperature of 70- 180 C., preferably 150-180 C., for 210 seconds to transfer the thermally transferable component in an unexposed portion to a receptor sheet, and then the latent image thus brought into a supercooled state is developed with a dust such as an electro-photographic toner to obtain a clear visibile image.

If, in this case, the copying material contains a sensitizer, it shows a sensitivity to light within the wave length range of 3000-6000 A., and therefore the exposure can be effected by use of not only near ultraviolet light but also a visible light.

Ordinarily, the exposed copying material is heated after placing a receptor sheet thereon. Alternatively, however, there may be adopted such procedure that only the copying material is heated and then a receptor sheet is placed thereon.

As the dusts to be used for making the latent image visible, there are phenolic, polyterpene, polyester, arylsulfonamide, polyphenyl and epoxy resins and rosin and the like natural rubbers and resins which have been colored with various pigments such as carbon black, Prussian blue. Toluidine Red and the like. Among these, a polyethylene dust colored with carbon black is particularly useful and has such advantages that it well adheres to a latent image portion in a supercooled state and the dust adhered to other portions can be simply and completely removed by such mechanical action as patting.

The dusted visible image thus formed may be fixed as such to obtain a printing master or may be transferred onto other receptor sheet. The fixing treatment can be simply effected by heating or by using a solvent. The resulting visible image is a permanently stable copy which is stable to both light and heat.

As the copying apparatus, a commercially available diazo copying machine can be used in the case of through copying, and an exposure device for diffusion transfer process can be used in the case of reflex copying.

PREFERRED EMBODIMENTS The following examples illustrate the present invention.

Example 1 Under a red safety lamp, a liquid of the composition shown below was applied, according to reverse roller coating method, to a tracing paper, so that the amount of the liquid applied became 25 cc./m. was then dried at a temperature below 70 C. to prepare a copying material.

Tribromomethylphenylsulfonel.5 g.

Acetanilide0.1 g.

Benzotriazole0.3 g.

1-( 3-ethylbenzothiazolidene -3- (4-quinolyl) propene-(2)-0.0l g.

Ethyl cellulosel.5 g.

Acetone20 cc.

The thus obtained copying material was a reddish light permeable material. The coated surface of the copying material was brought into contact with a polychromatic original bearing on a thick white paper an image printed with black, red, green and blue inks. The composite was irradiated for seconds, through the side of the copying material, with a light from a 500 w. tungsten filament lamp, i.e. with a light having an intensity of 100,000 luxes, at a distance of 30 cm. The thus exposed copying material was placed on a paper receptor sheet so that the coated surface thereof was contacted with the receptor 6 sheet. Subsequently, the composite was pressed for several seconds between fiat glass plates maintained at about C. Alternatively, the composite may be passed between heating bars or squeeze rolls, one or both of which are maintained at a required 'high temperature. The sheets were separated and on the receptor sheet there was, corresponding to the ink image of the original, a latent image of the heat sensitive component in a supercooled state, but said latent image was not clearly visible. Thereafter, carbon black was lightly sprinkled over the latent imagebearing receptor sheet, whereby the black powder well adhered to the latent image portion corresponding to the image portion of the original and the receptor sheet came to have a clear visible image. In place of the carbon black powder, a developing toner comprising an extremely fine globular mass of a colored thermoplastic resin was used to obtain a copy having a markedly beautiful background.

The copying material was capable of producing a clear image without resort to a receptor sheet transfer simply by applying the powder directly to the material after exposing and heating.

In either procedure the copy was converted into a permanent copy by heating in a chamber for a short period of time or, in the case of the copy bearing IR-absorbing color, by exposing to infrared ray sufiicient in intensity to fuse the thermoplastic resin onto the paper surface.

Example 2 Under a red safety lamp, a liquid of the composition shown below was coated onto a transparent polyester film to a wet film thickness of 4,11. and was allowed to dry until the liquid became non-sticky to obtain a transparent copying material.

Tribromomethyl-p-nitrophenylsulfone1 g. l-Pheny1-3-pyrazolidone0.2 g.

Ethyl cellulose0.5 g. Methylethylketone-10 cc.

The coated surface of the transparent copying material was closely contacted with the typewritten surface of an original comprising a typewritten white paper. The composite was subjected to exposure, through the side of the copying material, for 10-15 seconds, using a tungsten lamp. Subsequently, the coated surface of the thus exposed copying material was closely contacted with a receptor sheet and further contacted with an infrared ray-absorbing black paper, and the composite was uniformly heated to a high temperature by exposing the same for a short period of time to a radiant ray rich in infrared ray.

Thereafter, the receptor sheet was separated from the copying material and was lightly sprinkled with carbon black, as in Example 1, whereby the black powder well adhered to the latent image portion corresponding to the image portion of the original to obtain a clear visible image. A number of copies were obtainable be repeated transfer to receptor sheets.

Example 3 Under a red safety lamp, a liquid of the composition as shown below was coated on a tracing paper so that the coated amount became 23 cc./m. and was then dried at a temperature below 70 C. to obtain a copying material.

Tribromoquinaldine1 g.

Molecular compound of l-phenyl-B-pyrazolidone and hydroquinone0.2 g.

Ethyl cellulosel.5 g.

Acridine orange0.l g.

Acetone-20 cc.

The copying material was irradiated for 35 minutes through a photographic transparent image with an incandescent lamp having a brightness of 10,000 luxes, thereby making the material image-wise heat-insensitive, and was then heated together with a receptor sheet as set forth in Example 1. Subsequently, the receptor sheet was 7 separated from the copying material and was then treated in the same manner as in Example 1 to obtain a clear visible copy.

On the other hand, a copying material, which had been prepared in the same manner as above, except that Acridine Orange was excluded, was exposed for 10 minutes under the same conditions as above. In this case, the copying material, when heated together with a receptor sheet vaporized to form on the receptor sheet a latent image of supercooled material, and there was formed a visible image by treatment of said latent image with a toner.

The above examples have been presented for the purpose of illustration and should not be taken to limit the scope of the present invention. It will be apparent that the described examples are capable of many variations and modifications which are likewise to be included within the scope of the present invention as set forth in the appended claims.

What is claimed is:

1. Copying material comprising:

(a) a support;

(b) a heat-sensitive component on said support comprising a compound normally heat-activatable to a tacky condition and capable of retaining for a substantial period after cooling below the activating temperature a tacky, dustable condition; and

(c) a photosensitive component in intimate Contact with said heat-sensitive component comprising a compound activatable by light to a condition reactive with said heat-sensitive component to cause a substantial reduction in the heat-sensitivity of said latter component, said photosensitive compound having the general formula wherein R is a halogen atom, a substituted or unsubstituted alkyl, aralkyl, aryl, aroyl or heterocyclic radical or a radical represented by R-SO or RSSO, where R is of a character as listed for R and R R R are individually a hydrogen, chlorine, bromine or iodine atom, at least one being a halogen. 2. Material according to claim 1 wherein said heatsensitive component comprises a com ound selected from the group consisting of acetanilide, benzotriazole, o-toluenesulfonamide, N-ethyl-N-benzyl-2, S-diethoxyaniline, r'

compound, thereby creating a tacky condition in un- 6 exposed areas of said material.

5. A method of providing a visible image comprising:

(a) image-wise exposing to light material according to claim 1;

(b) uniformly heating the exposed material to a temperature sufficient to activate said heat-activatable compound, thereby creating a tacky condition in unexposed areas of said material; and

(c) contacting said tacky areas with a visibly contrasting powdered material.

6. A method according to claim 4 including, subsequent to said heating step, the steps of:

(a) contacting the tacky face of said material to a receptor surface; and

(b) separating said material face and receptor surface, thereby providing said dust-developable image on said receptor surface.

7. A method of forming an image comprising:

(a) image-wise exposing to light copying material according to claim 1;

(b) forming a face-to-face combination of said exposed material and a receptor surface;

(0) uniformly heating said combination to a temperature sufficient to activate said heat-activatable compound, thereby creating a tacky, transferable condition in unexposed areas of said material;

(d) separating said material and receptor surface, thereby depositing on said receptor surface a portion of said tacky compound corresponding to said unexposed areas; and

(e) contacting the tacky compound on said receptor surface with a powdered material.

8. A method according to claim 7 wherein said imagewise exposing is accomplished by:

(a) combining said material in face-to-face contact with an original bearing an image of greater light opacity and absorption than the background of said original; and

(b) exposing the combination to light for a time sufficient to activate the photo-sensitive component of said copying material, thereby defining in said material a heat-activatable image corresponding to said original image.

9. A method of making multiple copies of an image comprising:

(a) repeating the steps of claim 6 with a multiplicity of receptor surfaces; and

(b) contacting the resulting dust-developable images on said receptor surfaces with a powdered material.

10. A method of making multiple copies of an original comprising:

(a) repeating, with a multiplicity of receptor sheets, the last four steps of the method according to claim 8.

References Cited UNITED STATES PATENTS 3,042,515 7/1962 Wainer 96-1 15 3,100,702 8/1963 Rauner et al. 9628 3,360,367 12/1967 Stricklin 9628 3,390,995 7/1968 Manos 9648 NORMAN G. TORCHIN, Primary Examiner I. R. HIGHTOWER, Assistant Examiner US. Cl. X.R. 9648, 67

2 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 563 738 Dated 16 February 1971 fi wfl Kohei Itano, Masahi Nakano, Shoichiro Hoshino and Akira Kat It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 7, Line 43 "RS- SO, where R is of a character as listed for R should read ---R 50- where R is of a character as listed for R1;-

Signed and sealed this 18th day of May 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, J'R. Attesting Officer Commissioner of Patents