IL30177A - Light sensitive compositions and the use thereof - Google Patents

Description

This invention relates to photosensitive surfaces useful in photography and photo-copy reproduction processes and provides new photosensitive compositions suitable for coating surfaces to impart thereto the ability to receive a latent or visual image for replica or image repcroduction and copy work. The invention also includes processes for copying by developing the latent images which are produced on surfaces of photosensitive articles of this invention,using the compositions of this invention.

In such graphic arts as photography, photo-engraving, photolithography and collotype, silver halides and diazo compounds have been used as photosensitive materials which absorb energy from the visible spectrum in processes for making photographic images and in reprography. Such photosensitive agents have usually required close control of the chemicals used, of the time and of the amount of "treatment to develop the latent images present. Such processes are both expensive and impractical when it is desired to produce numerous copies of an object o image on an inexpensive surface such as a cellulosic web for example a cellulosic film, a sheet of paper or board, or a closely woven cellulosic textile. In addition the chemicals often used to develop and fix the silver halide or diazo photosensitised sunfaces have often needed close control of temperature and concentration, or the use of aqueou^ solutions to effect acceptable reproduction on the photosensitised surface.

It is thus desirable to find photosensitive materials and photochemically oxidisable materials which can be coated upon smooth surfaces to effect simple, inexpensive photoreproduction of images formed thereon without the need for special facilities such as dark rooms, and for extensive controls on time of exposure or development* In addition, silver used in most photographic and reproduction processes is in short supply, thus making it desirable &o develop a commercial inexpensive non-silver halide process.

It is thus an object of this invention to provide new, simple and inexpensive photosensitive materials useful for receiving latent or visual images as in photographic print or photocopy reproduction processes.

A further object of this invention is to provide new and useful methods for effecting photoreproduction of image-forming objects using a minimum of liquid reagents* In accordance with this invention there is provided a light-sensitive composition comprising (A) a photosensitive material which is activated by radiation within the near infrared to the ultra-violet portion of the spectrum, and (B) a photochemically oxidisable organic material having ethylenic unsaturation and having a molecular weight of at least 140 such that photoactivation of (A) serves to bring about oxidation of (B) by oxygen initially present in the surrounding atmosphere* The invention also provides a photographic element one surface with the said light-sensitive composition* Such photographic element when exposed to radiation within the near infra-red to ultrai-violet portion of the spectrum (hereinafter referred to as light) in the presence of gaseous oxygen produces a latent image which can be developed in various ways which will subsequently be explained.

The light-sensitive composition comprises a coafcable organic material having ethylenic unsaturation, which organic material is sufficiently stable under the conditions of use that it can be retained upon a base support in the presence of air. Upon exposure of thetreated surface to light the organic material is chemically attacked by oxygen in the excited state generated by the photosensitive material to effect chemical change therein which is fufficient to change the affinity of the organic material for a dyestuff in the areas of chemical attack with or without the intervention of organic solvents or other chemical seagents.

The photochemically oxidisable organic material may be any natural or synthetic organic material containing ethylenic unsaturation, which material may be applied to a suitable base aupport such as a glass or metal plate, a plastic solid or sheet, or -a surface of a paper sheet or board, and is sufficiently non-volatile at the temperature used. For use in this invention at ordinary room temperature the photochemically oxidisable organic material should have a molecular weight above 14Θ so that it will not be moved from the surface or from the reaction site by migration surface.

Natural materials which ma be used as the photo- chemically oxidisable organic material include rosin and the ethylenically unsaturated components thereof, terpenes such as abietic acid, neoabietic acid, maleopimaric acid, levopimaric acid, alpha-pinene , camphene, 3-carene, citronellol, aldehyde-modi ied rosin materials such as the formaldehyde-modified rosins, and fortified rosin materials such as those obtained by reacting rosin with alpha-beta-ethylenically unsaturated polycarboxylic acids and anhydrides thereof, as well as partial and complete esters of such acids as maleopimaric, maleic, fumaric, itaconic, aconitric and citraconic acids. The photocJpemically o idisable organic material may also be an unsaturated fatty oil or a fatty acid obtainable therefrom. Examples of such oils include olive, peanut, almond, neat's foot, peaan nut, lard, tung, safflower, cottonseed and soyabean oils. Non-glyceride ethylenically unsaturated oils such as tall oil may also be used.

Ethylenically unsaturated hydrocarbons of natural and synthetic origin may also be uaed. Examples include the aliphatic ethylenically unsaturated hydrocarbons having an average of at least 10 carbon atoms, e.g., 1-dodecene, l-tridecen^ 1—tetradecene, 1-pentftdecene , 1-hexadecene , l-docesen4 1-pentacosene, the non-terminally ethylenically unsaturated olefins such as 7 -heptadecene and 7,10 -hep-tadecadiene, and the aromatic ethylenically unsaturated hydrocarbons such as isopropenyltoluene, phenylisobutaae, Natural and synthetic polymeric organic materials containing free ethylenic unsaturation therein may also be used as the photooxidisable organic material* The ethylenic unsaturation may be non-terminal, e.g. present as a vinylene linkage; or terminal, e.g. present as a vinyl linkage or as a vinylidene linkage. In general, the. polymer backbone will be hydrocarbon in nature with any halide, ester, ether, hydroxyl, nitrile. phenyl or other group present pendant to the polymer backbone.

Illustrative examples of such ethylenically unsaturated polymers include natural rubbers and homopolymers and copolymers in which the monomer or one of the monomers is a diole in such as butadiene, isoprene, 2, 3-dimethyl- 1, 3-butadien$ piperylene, chloroprene, bromoprene ,2 - acetoxy - 1,3 -butadien¾ 2-methyl - pentpdiene and 2 - eth lhexadiene . The copolymers may be prepared from oc y e er, v ny n - dodecyl ether, v nyl n - tetra-decyi ether, vinyl n - hexadecyl ether and vinyl n -octadecyl ether; and the vinyl alkenyl ethers, e.g. divinyl ether, vinyl octenyl ether, vinyl tetradecenyl ether and vinyl octadecenyl ether; (b) Vinyl esters, e.g. vinyl acetate, vinyl butyrate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate and vinyl stearate; methacrylic and crotonic esters, e.g. methyl methacrylate , ethyl acrylate, propyl acrylate, amyl acrylate, n - heptyl acrylate, n - octyl methacrylate , n - nonyl acrylate, n -undecyl acrylate, n - tetradecyl acrylate, n - hexadecyl acrylate, n - octadecyl acrylate, vinyl acrylate, hexenyl methacrylate, dodecenyl acrylate, octadecenyl acrylate and ethyl crotonate; (h) Allyl esters, e.g. allyl acetate, allyl buty-rate, allyl caprylate, allyl caprate, allyl laurate, allyl myristate, allyl palmitate and allyl stearate; (i) Allyl alkyl ethers, e.g. allyl ethyl ether, allyl n - octyl ether, allyl n - dodecyl ether, allyl n -tetradecyl ether, allyl n - hexadecyl ether, allyl n -octadecyl ether; and vinyl alkenyl ethers, e.g. allyl vinyl ether, allyl octenyl ether, allyl tetradecenyl ether and allyl octadecenyl ether; (j) Cycloaliphhtic vinyl compounds, e.g. vinyl cyclohexane ; (k) Aryl vinyl compounds, e.g. styrene, vinyltoluene , vinylbiphenyl, vinyl naphthalene and the nuclear chloro sty enes ; (l) Heterocylic vinyl compounds, e.g. vinyl pyridine and vinyl dihydropyrane ; (m) Alpha-olefins , e.g. ethylene, propylene, butene -1, octene — 1, dodecene — 1, tetradecene — 1, hexadecene - 1 and heptadecene — 1, dichloroethylenes and tetrafluoroethylene ; and (n) Branched olefins, e.g. isobutylene, isoamylene and 2,3,3 -trimethyl - 1 - butene.

The unsaturated polymers which are used may also be prepared by copolymer!sation of two or more different diole ins, e.g. from a mixture of butadiene and piperylene, either in the presence or absence of one or more non-dienic copolymerisable monomers.

The preferred ethylenically unsaturated monomers are those having at least one valence attached to an electronegative substituent such as a double artriply bonded carbon atom e.g. vinyl, propynyl, phenyl, nitrile and carboxyl. The preferred ethylenically unsaturated comonomers are those listed above under (a), (b) , (c) , (d) (g) , (j),(k), (l) and (n) · The ethylenically unsaturated monomers listed under classes (k) and (n) are particularly preferred.

The amount of copolymerised diolefin monomer in a copolymer of diolefin monomer and monoethylenically unsaturated monomer is generally from 0.1 to 99% by weight. However, it is preferred that such polymers contain at least 1$ by weight of copolymerised diolefin monomer.

The physical characteristics of the ethylenically unsaturated polymers which can be photochemically oxidised molecular weight polymer oils containing relatively,[ few ethylenically unsaturated bonds to high molecular 1 weight rubbers and resins such as those resulting f om the polymerisation or co-polymerisation of diolefins\ in the absence or presence of one or more non-dienic copOlymerisable monomers. \ The photosensitive materials which are used as the second component of the compositions of thi invention in general undergo no permanent chemical change. The ■sIe Γ . materials may be any organic compound or mixture of com-* pounds which become excited as a result of photon absorpttionnand enters into a sequence of chemical reactions with atmospheric oxygen leading to a photochemical oxidation reaction in which the substrate (l) becomes oxidised , and the sensitiser is generally regenerated at the end of the cycle.

The preferred photosensitive materials for use herein are those generally referred to as being of the porphin type. This type of material may be described as any compound having the porphin structure, i.e. four pyrrole rings linked by single carbon or nitrogen atoms, and includes related compounds such as the porpnyrazines, the phthalocyanines and the chlorophylls.

Particular useful photosensitive materials are the aromatic group meso-substituted porphin compounds. Among these are the mesotetraarylporphins. Thesecompounds are porphins in which aryl groups having from 6 to 24 carbon atoms are substituted on the bridging carbon atoms of the together by four bridging carbon atoms to form a great ring, Examples of aryl groups which may be substituted in the meso-position of these compounds are phenyl, chlorophenyl, diclorophenyl, meihylphenyl, N,N - dimethylaminophenyl, hydroxyphenyl , naphthyl, biphenylyl, anthracyl and phenanthryl. In addition to the substituents in the aryl groups noted above, the aryl groups may also have any one or more other ' substituents, e.g. alkoxy groups having 1 to 20 carbon atoms such as methoxy, ethoxy, isopropoxy, butoxy and hexyloxy, provided that these do not change the fundamental aoomatic character of the groups. These photosensitive porphins including the above eaemplified arylporphins, can have various other substituents, particularly in the two beta positions in the pyrrole rings,, e.g. such substituents as alkyl (l to 20 carbon atoms) vinyl or allyllgroups or alkanoic acid groups such as methylcarboxy oarethylcarboxy.

Examples of porphin compounds which are useful as photochemical sensitive materials in this invention are the arylporphins such as the tetraphenyltetrazoporphins and the metal chelates thereof, e.g. magnesium and copper tetraphenyltetrazoporphins, tetraphenyl tetrazoporphin acetate and sulphate, and zinc, nickel and cobalt tetraphenyltetrazoporphins; and meso - aryl porphins including alpha beta, gamma, delta-naphthylporphin and the metal chelates thereof, e.g., tetraphenylporphin, tetrakis (2,4 - dichlorophenyl) porphin, tetrakis (2 - furyl) porphin, tetrakis(4 - methoxyphenyl) porphin, etrakis(4 - methyl zinc chelate, tetrakis(4 - nitrophenyl) orphin and tetrakis(4-dimethylaminophenyl) orphin zinc chelate; the tetrabenzomonoazo and tetrabenzodiazo- porphins; the 1,2,3,4,5,6,7,8 -octaphenylporphins and octa- phenylazoporphins such as octaphenylporphyrazine; the tetrabenzoporphins and the metal chelates thereof, e.g., tetrabenzoporphin and the zinc chelate thereof.

Other useful porphin type photosensitive materials which may be used include chlorophyll, such as chlorophyll a and chlorophyll b, haemin, the tetrazoporphins , vanadium tetraphenylporphin, chlorophyllin salt derivatives such as the reaction product of an alkali metal chlorophyllin salt and sodium bisulphite, hematoporphin, mercury proto- and hemato- porphins, vitamin Β^2 and its derivatives, tetrakis(l-naphthyl) porphin and cobalt protoporphin.

Belated porphin type materials which are azaporphyrins include the phthalocyanines such as metal-free phthalocyanine and the metal complexes of phthalocyanine such as the copper, zinc, magnesium, tuggsten, manganese, iron, nickel and cobalt phthalocyanines as well as phthalocyanine derivatives such as the copper, barium and magnesium salts of phthalocyaninesulphonic acid, a e lstod ef phthalocyaninesulpaonic- acid, acetylated phthalocyanine, alkoxy- and aryloxy-benzo-substituted phthalocyanines, »5' ,5",5' -tetraajnino - copperphthalocyanine - 4,4',4",4'"-tetrasulphonic aaid, copper and magnesium tetramethyl-thiophthalocyanines, arylthioethers of phthalocyanines, vinyl substituted tetraazoporphins and polymers thereof oxidation of organic ethylenically unsaturated bonds in the photochemically oxidisable organic material in a manner which makes this phenomenon useful for photo-reproduction purposes. The photochemically oxidisable organic material (l) and the photosensitive material (2) are brought together on a suitable surface, radiation is incident upon selected areas of the treated surface in the presence of gaseous oxygen, in an amount sufficient to effect photochemical oxidation to a significant extent and then the photochemical feaction is stopped by removal of the radiation. The extent of oxidation which occurs may vary widely depending upon the material (l) and the photosensitive material (2) . The dye receptivity material are also important. For example, an organic material comprising a polyisoprene polymer coated on a desired surface will require more oxidation to produce a bright image than will an organic material consisting of a polymer'cf 60 parts by weight of styrene and 40 parts of butadiene because of the difference in the dye receptivity characteristics of the two organic materials.

With organic materials euch as styrene—butadiene co- f polymers containing 60 part os* styrene and 40 parts of butadien, and which may contain small numbers of units derived from other functional monomers such as itaconic acid or its anhydride, oxidation sufficient to provide -9 -7 for the uptake of about 10 to about 10 moles of oxygen per square centimeter of coated surface is generally quite suitable for producing an intense image upon treating the surface with a dyestuff. Generally visible images can be obtained whemsufficient oxidation has occurred to provide —2 —10 for the uptake of 10 to 10 moles of oxygen per square centimetre of surface of the organic material. The depth of penetration of the oxidation into the organic material is not known. However, with the styrene-butad ene copolymer referred to above, oxidation to the extent of —8 —9 to 10 mdes of oxygen per square centimetre uptake by the polymer corresponds to a mininum coating depth of about 250 to 500 Angstrom units if all the double bonds in the polymer are oxidised. It will be recognized that in this application of the photooxidation reaction txr the weight concentration of the photosensitive material. sunface with a dyestuff, or by other methods.

The photosensitive material and the photochemically \ oxidisable organic material may be applied to the desiredl surface separately, or as a single composition by conventional methods such as incorporation in a suitable diluent emulsipn and coating therewifli. They may also be applied together : . with suitable pigments wherein the photochemioally oxidisaHe organic material (l) acts not only as the oxidisable material but also as a component of a pigment binder or adhesive. A typical example of a polymeric composition used for this purpose is a 48$ by weight aqueous latex emultion of a styrene/butadiene copolymer used either alone or together with starch or casein type materials as pigment binders in the coating of paper surfaces to make high quality printing papers. A coating composition may be prepared containing a small amount of the photosensitive material) e.g.. tetraphenylporphin. a pigment or a mixture of pigments, such as kaolin clay and titanium dioxide, and a binder or adhesive, e.g. an aqueous latex of a styrene/ butadiene copolymer, the total solids content of such composition ranging from 10$ to lOo by wei¾hi. The coating to a metal, plastic or glass article, and may be used immediately or stored and packaged for future use for effecting photocopying.

It will be appreciated that the selection of the diluent or other vehicle used with the photosensitive compositions will depend upon the nature of the substrate being treated and the photosensitive material in order to obtain a complete surface coverage. , Diluents which may be usdd alone or in combination with the photosensitive compositions of this invention are chlorinated hydrocarbons, such as ethyl chloride, methylene chloride, chloroform, carbon tetrachloride, trichloropropane , monochlorobenzene, trichloroethylene, perchloroethylene , difluorodichloro - methane, orthochloro- benzene, chlorinated polyphenyIs and chlorinated paraf/ins; hydrocarbons such as heptane, hexane, cyclohexane, eiscosane octadecene, benzene, xylene and toluene; polyethylene glycols; n-butoxy - ethanol; esters such as methyl acetate, ethyl acetate, ethoxyethoxyethyl acetate, di(2- ethylhexyl) phthalate, dimethyl phthalate, dilmethoxyethyl) phthalate and ditetrahydrofurfuryl phthalate; ketones such as acetone, raehjtyl ethyl ketone, cyclohexanone and undecanone; butyl stearate and dimethyl sulphoxide. ¥hen the photooxidation reaction has progressed to the desired extent for photo-reproduction, the reaction may be essentially stopped by ceasing to irradiate the photo-reproductive element with intense light. Usually from 10 to 60 seconds exposune to a source of light energy equivalent to a 1000 watt white light, 12 inches away from The dyestuff used to fix or develop the latent image produced "may be any dyestuff which has different ' 'J- affinities for the oxidised and non-oxidised areas of the irradiated surface. Dyes found useful are the organic solvent soluble or dispersible or oil soluble or dispersible dyes such as the kerosene and alcohol soluble dyestuffs, e.g., the triphenylmethane, azo and disperse dyestuffs. Ve have found that dyestuffs dissolved or dispersed in a solvent such as deodorised or highly refined kerosene generally react with the non-oxidised portion of . the irradiated surface and that dyestuffs dissolved in an alcohol such as 2 - ethylhexanol usually react with the oxidised portions of the irradiated surface. The particular areas with which the dyestuff reacts appears to depend upon the selective swelling characteristics of the solvent used, the effect of the dydstuff on the solubility parameter of the solvent, and upon the polarity of the dyestuff.

Although these factors appear to control the areas acted on by the dyestuff, the actual chemical or physical mechanism of the reaction and image application brought about by the dyestuff is not fully understood.

The solvents or disperslkng agents for the dyestuff may be any organic material which will dissolve or disperse the dyestuflf and which will aid in selecting the areas acted on by the dyestuff, viz. the oxidised or non-oxidised areas of the irradiated surface so that differences in photooxisation in different areas of the surface can readily be made apparent thereby. Suitable solvent or diluents opaque white sheet, include Sudan Brown, Sudan Red and Calco Oil Red dissolved in deodorised kerosene. Examples of dyestuffs usefli for developing latent images produced with a negative image forming subject, e.g., a photographic negative film, include Crystal Violet, Malachite Green, Victoria Blue and Nigrosine B dissolved in 2 - ethylhexanol.

The areas to which the dyestuff is directed depends both upon the dyestuff and the solvent. For example, Sudan Brown dissolved in kerosene is preferentially taken up by the nonoxidised areas. A strongly basic dyestuff like Crystal Violet is preferentially taken up by the oxidised areas except at those sites at which greater greater oxidation inversion appears to occur and the dyestuff is rejected in the overoxidised areas.

The dyestuffs may be simply wiped upon the exposed photooxidised element using a rag or brush or be sprayed on or applied by other conventional methods, and then dried by wiping the dyestuf -treated surface with a dry cloth or tissue. The result is a clear useful print or copy of the subject to be copied or reproduced.

Chelates, graphite and metal oxides may also be applied to the exposed photochemtcally oxidised surfaces to prepare the desired images.

The photosensitive materials may be used alone or in admixture to make more ef ective use of the incident radiation, so long as they do not interfere with the light absorbing ability of each other. For example, Rose Bengal and Methylene Blue may be used together at photosensitive materials with the preferred porphin type of photosensitive materials such as tetraphenylporphin. Suitable base or support materials include matals, e.g., steel, aluminum plates, zinc, copper and magnesium as sheets or foils, glass, wood, paper, composition board, cloth, cellulose esters, e.g., cellulose acetate, propionate and butyrate, the films or plates composed of various film-forming synthetic resins or high polymers, such as the addition polymers, including those mentioned for use in the photo-oxidisable layer and in particular of ethylenically unsaturated polymers, e.g., copolymers of vinyl chloride with vinyl acetate, styrene, isobutylene or acrylonitrile; the linear condensation polymers such as the linear pol amides, e.g., polyhexamethylene sebacaraide, and the polyester amides, e.g., polyhexamethylene adipamide/ adipate. Fillers or reinforcing agents can be present in the synthetic resin or polymer bases such as the various synthetic modified or natural fibres, e.g., cellulosic fibres, for instance, cotton, cellulose acetate, viscose rayon and paper; glass; wood? and s the nylons. These reinforced based may be used in laminated form.

The image-forming process makes use of visible light, a photosensitive material and a photochemically oxidisable organic material such as a styrene - butadiene copolymer which is capable of producing a latent image by using either a reflex, a reflective or a transmit- tive system. The latent image is rendered visible by means of suitable dye systems to produce high quality continuous tone pictures.

The latent image may also be used selectively to deposit finely divided solids euch as metals, metal oxides, graphite and chelates. If graphite is used, it may be used as a conducting base for electroplating metals. If natural rubber is used as the substrate, the unexposed area may be selectively dissolved to produce a relief image. Multicolour images may also be produced by the practice of this invention.

The compositions of this invention are generally useful in the graphic arts, when a reproduction of a drawing, design or plan is desired. Thus, in the manu automobiles, boats, radio and electrical equipment, the materials to be used, such as steel or aluminium, may be coated with the light-sensitive compositions of jfchis invention, dried, exposed through the master drawing and the latent image developed. The finished print is an exact reproduction of the original and adheres firmly to the metal or other material* Stencils or lettered transparencies may also be used to reproduce directions or identification numbers on parts of finished articles. The photo-sensitive elements of the present invention may also be used as print stock in the production of black and white prints.

The photosensitive layer is exposed to light, generally through a process transparency, e.g., a process negative or positive (an image-bearing transparency consisting solely of substantially opaque and substantially transparent areas in which the opaque areas are of substantially the same optical density) ox- a so-called line or halftone negative or positive.

It is possible to expose the photosensitive layer through paper or other light-transmitting materials.

A stronger light source or longer exposure times must, however, be used. Reflex exposure can also be used, e.g., in copying from paper or translucent films.

Suitable light sources include carbon arcs, tungsten and me cury-vapour arc lamps, fluorescent lamps, argon glow lamps, electronic flash units, photographic flood lamps and sunlight.

The invention will be more fully understood, by reference to the following examples. )·Ί ■ ' Photosensitive compositions suitable for .coating paper and other suitable base supports are prJpared to contain (l) a solvent or carrier (2) a photosensitive material and (3) a photochemically oxidisable organic material which is photooxidised when the composition is v exposed to light. Such compositions are illustrated in Example 1 below wherein the compositions A to T are applied to a styrene-butadiene copolymer coated paper. All parts are by weight unless otherwise specified.

Example 1 Compositions A .through T Com osi ion Compositions A to T are applied to coated paper- board. Exact positives of the positive transparencies ! used to mask the light sensitive composition are produced when the compositions are. exposed to light through the transparencies, and further developed with a kerosene solution of Colour Index Solvent Brown 22. ' j Example 2 I ' . '· . ί A solution containing parts of ditetrahydrofurfuryl phthalate and 1 part of acetophenone is applied to a paperboard . copolymer previously- coated with a styrene-butadiene/ latex. A suitable positive transparency is p l ar rl nvt> r t. n. r. nn rt nn rr) . Thr- nfi ri iii then exposed for a period of 15 minutes to an 85 watt ultraviolet light. The exposed board is wiped with an odorless kero- .

Colour Index Solvent Brown 22. sene solution containing 0.h nf n nni Ttrnwn N riyp . A clear image of the transparency is obtained on the board. ! Similar results are obtained as in.. Example 2, when the. . by acetophenone is replaced with jenzophenone, benzoin, benzil or triphenylene.

Example 3 a A paperboard previously coated with/styrene-butadiene copolymer /latex is coated with Composition A of. Example 1. A lantern over slide transparency is placed on. the coated board. A fluorescent ■' *: light is used to expose the board for about 10 minutes. The image is developed with a kerosene solution of uP nt Drown -Jl- dyo^ Colour Index Solvent Brown 22.

: ' . Example 4, · 1: Example 3 is repeated with a 200 watt incandescent · ' i j . flood lamp ein user! as the light source. · j Example ' ■ An opaque paper sheet coated with a styrene-butadiene copolymer j latex is treated with a solution having the following composi- • ■ , I tion: ; i · Levopimaric-formaldehyde adduct 100' parts ! Chloroform 400 parts ; Chlorinated paraffin (Chlorowax 50) 250 parts Ditetrahydrofurfuryl phthalate 600 parts _ _ Tetraphenylporphin . · 5 parts The resulting coated sheet is used for reproducing a type-written letter on light bond paper by directing a 1000 watt light source located 14 inches above the paper sheet for 30 seconds with the letter interposed between the light source and the treated paper. The image is. developed with a 0.4 solution of Calco Oil Violet V dissolved in dodecane.

Example 6 j Following the procedure of Example 5, similar results j are obtained when levopimaric acid or dihydroab etic acid j is substituted for the levopimaric acid-formaldehyde adduct.

Example 7 Composition U The following solution is prepared.

Parti).

Chloroform 600 Chlorinated paraffin (Chlorowax 50) . 500 Ditetrahydrofurfuryl phthalate . .1200 Levopimaric acid- ormaldehyde adduct 50 ' t Gum Rosin 100 Maleopimaric Acid 50 A number- of photosensitizer solutions are prepared by j adding 5 parts of the photosensitve materials listed below j to 1000 parts of composition U. Each of the resulting solutions is applied to a board coated with styrene-butadie ne copolymer latex. The board is then covered by a transparency and exposed to a 300 watt light at 10 inches for four minutes. A kerosene solution of Colour Index Solvent Brown 22, Calco Oil Violet1, Violet BN or Nigrosin B is used to produce a photographic i image on the board. , ·, , ·■--.- • iie results oDWinea are noted below.

Inter r tation Photosensitive material of. Resulting Developed Image Tetraphenylporphin Good picture Methoxytetraphenyl.porph.ln Faint picture Zinc te raphenylporphin Faint picture Hydrox etraphen lporphin Dark background Naphthyltetraphenylporphin Good picture 3, ~Dichlorotetraphenylporphin Good background and de inition 2 , -Blchlorotetraphenylporphin Good background and definition Chlorophyll Good picture - fair definition Eosin Y Faint picture' Eosin B Faint picture Rose Bengal Good picture Example 8 ■ i . · Λ mixture containing 3 parts of 2, 4-dichlorotetra- phenylporphin, 400 parts of chloroform and l600 parts of e co sane is heated to a temperature of about 40 to 50°C and .applied copolymer to a paperboard coated with a styrene-butadiene/lntex.. An ex- I cellent image is produced when the board is covered with a transparency, exposed to a 500 watt lamp and developed with. a. Colour Index Solvent Brown 22. 1 ' DuPoni; Brown . dyo oolution. '■ ■ .......J.

I Examples 9 to 13 Proceeding as described in Example.8, the photosensitive material solutions described below are substituted for that used in Example 8 to obtain excellent reproduced images.

Examples 14 to 20 These examples illustrate the incorporation of both the | photosensitive material and the photochemically oxidisable j organic material in the surface coating applied to a cellulosic web. A standard coating base is prepared as follows: s While tli.l mi ture being s Li rred, 4'J>0 gromc ol" clay and 530 i grama of titanium dioxide are added. The resulting mixture is stirred for 10 minutes. One hundred twenty nine grams of ! a' 60/40 styrene-butadiene polymeria- latex containing 8$ solids. ■ /•"and 1.1 grams of water are added to 200 grams of the standard ■ i coating and the mixture is stirred gently for 15 minutes. All- quota of this coating solution are mixed with the photooenal- below tize.r solution a*- indicated/ in each example bolow^ and applied to a sulfite paperboard., .The r sults of the evaluation of each treated board as ^photographic substrate^ after exposure through transparency for 1 to 2 minutes using a 1000 watt lamp -and sub- stuff recorded, sequent developing with dye/ are gi n h -inw.

Example 21 , he styrene-butadiene copolymer latex coating material is replaced by a natural rubber latex. The photosensitive *- ,·.,:;J to produce an image when covered with a transparency, s jse 1 to a 1000 watt lamp for 1 to 2 minutes and developed o suitable dyestuff. ^ "~ Example. 22 · v, A stundard paperboard is double coated by the air ^ copolymer knife method with a s yrene -butadiene /latex containin a :: clay/titanium di¾xide pigment in . a ratio of two pprts of , photosensitive pigment to one part of styrene-butadiene copolymer. A /feensi* . :oiaor solution containing 83. 8 mg. of tetraphenyl porphin, 6 . 5 g. of chlorinated polyphen 1 , 13 · 5 g« mineral oil and 8 g. surface of the • of chloroform is wiped on the/ coated board. A negative trans- parency is placed on the board and exposed to a 1000 watt lemp for -about 1 minute. The board is dusted with/activated carbon and the excess is brushed away. An image is produced on the adheres to the unexposed areas of the surface board. The carbon 16 -found to adhoro to tho noxpocod aroa. of the board.

Example 23 A standard paperboard is coated with a pigmented photosensitive Gtyrene -butadiene copolymer latex, A bmbltl-i r solution of then Example 22 is applied to the coating. The coated board is/ ex- posed to light through a photographic negative transparency. /latent ' using a . The 'image on the board is developed with the use of a solid dye solution of crystal violet in a petroleum wax having a. melting point of 117 °F.

Example 2 , , 0 A standard paperboard coated with a pigmented styrene- rendered butadiene copolymer latex ( 2 ; 1 pigment to binder) is flensifti r.ert /photosensitive with a solution of 320 mg of tetraphenylporphin, 0 g- of chloroform, 90 g. of a 1 : 1 mixture CIO; hydrocarbon and. chlorinated Selected polyphenyl. PAJ. titular areas of two sets o the above-treated boards are exposed to light. The first board is wiped with un jrctUu mce obtained for each area Is shown below. then with . ■ .', board is first wiped with kerosene, followed by a ■ finally with ,i »_>lution of Calco oil red B Q__and' i%e«. a 2-ethyl- . ·,·-;' „· jlut Ion of Victoria Blue R. , The surface is finally rfiUi dry graphite- The resistance obtained for each v . jf S !U shown below.

I Board No. 1 Board No. 2 s¾ ) · . · ■'■' ■ **i-.«xposed Area >00,000 ohm/cm . 40., 000-50, 000 ohm/cm x& oscd Area °¾ . o j A surface which is differentially conductive is obtained on each board. j Example 25 rendered photosensitive A standard board coated and 'consitiaed as in Exam- pie 24 is exposed to light through ,a negative. The image is first developed with a kerosene solution of Sudan Brown <tye *: then and tiieja- the surface/ls-polished with a kerosene solution of Victoria Blue ,R to obtain a bronzed image.- Example 2(3 rendered photosensitive A standard board coated and sensitized as in Exam- p e 24 is exposed to light with a strip of aluminum foil laid or upon the board. After a to.10 minute exposure the coated surface is wiped with kerosene and graphite. The graphite is up selectively deposited/on the nonoalldized area. The board is then copper' plated using 1.5 volt dry cells and a copper sul- fite sulfuric acid bath. The copper is deposited /¾¾ the graph! ed areas. in a similar manner A piece of brass shim stock similarly. ■treated JUia. to the , ■ abovo paperboard is copper plated by the same procedure, The . copper is deposited on the graphited area. .

Example 2.7; photosensitive .described in The aonoi iaei1 solution ·&£ Example 24 is applied to a paperboard coated with a natural rubber latex. The coated board is exposed through a transparency. The surface is then yield wiped with kerosene to obtain a relief image. ' ,\ i ' . , Similar results are obtained when Rose Bengal Is B'.'h- photosens tive stituted for the tetraphenylporphin in the .sensitirer solution. j Example 28 . · A sulfite bleached carbon/¾¾oc is coated with a ^ to mil thickness of coating color containing 2 parts of pigment poly- (90:10 clay-titanium dioxide) and 1 part of/vinyl acetate latex rendered photosensitive i of 50-60 solids. The boarH is oonoitiaod with a solution con- • ' , f taining tung oil, tetraphenylporphin, chloroform and octadecorie. After exposure through a transparency the image is developed Example 29 Similar results to those described in Example 28 are obtained when an ethylene/vinyl chloride copolymer latex having 50-60 solids content is used iri place of the polyvinyl acetate latex.

Example 30 The procedure described in Example 28 is repeated using a butyl acrylate copolymer latex containing 50-50 solids in •place of the polyvinyl acetate latex. An excellent image is; obtainec -frainoa=> Example 31 Example 28 is repeated using polyethylene tere-phthalate as the base support in place of the carton stock.

Example 32 Following the procedure described in Example 28 a polyvinyl I :hloride latex is substituted for the polyvinyl acetate latex. I ■ Example 33 · " ' ' ' : Λ sheet of tracing paper is coated with etyrenej- butadiene latex containing finely divided polyvinyl chlori!?.. photosensitive j Λ -i solution consisting of 2 parts of tetra.phenyl-l .porphin, 100 parts of maleopimaric acid, 300 parts of chloroform and 200 parts of di-$ ethylhexyl) phthalate is applied to the coated surface of the paper. The treated paper is placed Example 36 The procedure described in Example 35 is repeated and I The Procedure described in Example 35 is repeated jL but the exposed substrate is developed with a solution of silver nitrate in a mixture of ethanol, isopropanol ! and octanol. The treated area is then exposed to hydrogen i chloride vapours and light to obtain a brown image.

Example 38 The procedure described in Example 35 is repeated but the exposed area is developed by applying in sequence the following solutions. (1) Potassium hydroxide dissolved in a mixture of ethanol and octanol, (2) Hydroquinone dissolved in octanol, (3) Silver nitrate dissolved in water and a mixture of ethanol and methanol. j An image is obtained in which the metal is selectively ' ! deposited upon the oxidised areas.

Example 39 The procedure of Example 35.is repeated, ferric sulphate being substituted for ferric nitrate to produce ' a yellow positive image.

I Example 40 ! The procedure of Example 35 is repeated except that copper sulphate is substituted for the ferric nitrate A positive image is produced.

Example 41 A pigmented styrene/butadiene copolymer latex coated paperboard treated with the photosensitive solution described in Example 24 is covered with a vinylidene copolymer film which adheres tightly to the surface in some .areas and leaves wrinkles in other areas. The board assembly is exposed to. light and the surface is then ! ΐ ' developed with a solution of Crystal Violet in 2 - ethyl- r hexanol. The areas underlying the wrinkles selectively absorb the dyestuff . The areas to which the film adheres tightly show a lack of dyestuff receptivity) due to lack ; ; I i . ; ' of oxidation.

Example 42 Proceeding as described in Example 41, drops of water j i are deposited on the coating in place of the plastic film. | ' 1 · ! After exposure to light and developing with a solution of Victoria Blue in 2 - ethylhexanol , the areas underlying the drops of water are most discernible as light areas upon| a dark background. The Victoria Blue dyestuff solution1 j is selectively absorbed by the oxidised areas: the drops 1 of water prevent oxidation in the areas which underlie them.

Example 43 The procedure of Example 42 is repeated, except that a solution of Sudan Brown in kerosene is used to develop ! the exposed surface. The areas underlying the drops of water appear as dark areas upon a light background. The Sudan Brown solution is selectively absorbed by the non-oxidised areas.

From the foregoing it will be evident that this invention provides novel photosensitiser compositions which are useful for a variety- of copying, printing, decorative and manufacturing applications. The advantage lies in the j inexpensive, quick and simple procedures involved in the general application of the compositions of this invention, j is found to produce an image when covered with a transparency, exposed to a 1000 watt lamp for 1 to 2 minutes and developed with a suitable dye.

Example 22 A standard paperboard is double coated by the air . knife me thod with a otyrene-butadiene latex containing a 90 ;; 10 clay/tItanium dioxide pigment in . a ratio of two ports of pigment to one part of styrene-butadiene copolymer. A sensitizer solution containing 83.8 mg. of tetraphenyl porphin, 6.5 g. of chlorinated polypheny!, 15 · 5 g- mineral oil and 8 g. of chloroform is wiped on the coated board. A negative trans- parency is placed on the board and exposed to a 1.000 , watt lamp for about 1 minute. The board is dusted with activated carbon and the excess is brushed away. An image is produced on the board. The carbon is found to adhere to the unexposed area..

Example 2^> A standard paperboard is coated with a pigmented. styrene-butadiene copolymer latex. A sensitizer solution of ; Example 22 is applied to the coating. The coated board is ex- · posed to light through a photographic negative transparency. The image on the board is developed with the use of a solid dye solu io of crystal violet in a petroleum wax having a. melting point of 11? °F.

Example 2 A standard paperboard coated with a pigmented styrene-' butadiene copolymer latex (2^ 1 pigment to , inder) is sensitized with a solution of 320 mg of tetraphenylporphin, 50 g„ of chloro form, 90 g. of a lsl mixture CiQ hydrocarbon and chlorinated polyphenyl. Particular areas of two sets of the above-treated boards are exposed to light. The first board is wiped with graphite. The nonexposed areas become darker than the exposed are . The resis ance obtained for each area is shewn below.4' ' ' The second board is first wiped with kerosene, followed by a kerosene solution. of Calco oil red BMC and then a 2-ethyl- hexano.l solution of Victoria Blue R.> The surface is finally wiped with dry graphite. The resistance obtained for each' area is shown below.

Board No. 1 Board No. 2 Non xposed Area 500,000 ohm/cm 40., 000-50, 000 ohm/cm . Exposed Area OQ .

' A surface, which is dif erentia l conductiv is Obtained on each board.

Example 25 . ' A. standard board coated and sensitized as in Example 2 is exposed to light through a negative. The image is first developed with a kerosene solution of Sudan Brown dye and then the surface is polished with a kerosene solution of Victoria Blue R to obtain a bronzed image..

Example 26 A standard board coated and sensitized as in Exam-· pie 24 is exposed to light with a strip of aluminum foil laid on the board. After a to 10 minute exposure the coated surface is wiped with kerosene and graphite. The graphite is selectively deposited on the nonoxidized area. The board is then copper' plated using 1.5 volt dry cells and a copper sul- fite sulfuric acid bath. The copper is deposited on the graph.i ed areas.

A piece of brass shim stock similarly treated as the above paperboard is copper plated by the same procedure. The ..copper is deposited on the graphi ed area.

Claims (9)

1. ¥ΗΔΤ IS CLAIMED IS: 1. A light-sensitive composition comprising (A) a photo-?' sensitive material which is activated by radiation vithin the near infra—red to the ultra-violet portion of the spectrum, and (B) a photochemically oxidisable organic material having ethylenic unsaturation and having a molecular weight of at least 140 such that photo-activetion of (A) eerves to bring about oxidation of (B) by oxygen initially present in the surrounding atmosphere.
2. 2. A composition according to claim 1, in which the photosensitive material is of the porphin type.
3. 3. A composition as claimed in claim 2, in which the photosensitive material is an arylporphin or a metal chelate thereof, a tetrabenzomonoazoporphin, a tetrabenzodiazopor phin, a 1,2,3,4,5,6,7,8 — octaphenylpor hin or octaphenyl- azoporphin, or a tetrabenzoporphin or a metal chelate thereof.
4. 4. A composition as claimed in claim 2, in which the photosensitive material is phthalocyanine or a metal chelate thereof.
5. 5. A composition as claimed in claim 2, in which the photosensitive material is a chlorophyll.
6. 6. A composition according to claim 1, in which tie photosensitive material is a fluorescein type dyestuff.
7. 7. A composition according to claim 6, in which the fluorescein type dyestuff is Eosin or Rose Bengal.
8. 8. A composition according to claim 1, in which the photosensitive material is a triarylmethane dyestuff.
9. 9. A composition according to claim 8, in which the triarylmethane dyestuff is Crystal Violet, Malachite Green or Victoria Blue, ( 10. A composition as claimed in any of the preceding claims in which the material having ethylenic unsaturafcLon > is a copolymer of (i) a diole in and (ii) a vinyl .ether* , a vinyl ester, a vinyl halide, a vinyl ketone, acrylic, methacrylic or crotonic acid or a derivative thereof, a ■ eyeloaliphatic vinyl compound, an aryl vinyl compound or <\ a branched chain olefin. 11. A photographic element comprising a base support. ^ \ coated upon at least a part of one surface with a composition-according to any of the preceding claims. 12. A method of preparing a visible image which comprises irradiating selected areas of the surface of a photographic element according to claim 11 with radiation within the near infra-red to the ultra-violet portion of the spectrum in the presence of gaseous oxygen and thereafter treating the irradiated surface with a dyestuff dissolved or dispersed in an organic solvent, or by depositing upon the irradiated surface. a finely divided solid the dyestuff or finely divided solid having different affinities for the irradiated and non-irradiated areas of the surface. 13. A method of preparing a relief image which comprises irradiating selected areas of the surface of a photographic element having a natural rubber substrate eoated with a light-sensitive composition according to claim 1 and - 35 - selectively dissolving the unexposed areas thereof, said irradiating being with radiation within the near infra-red to ultra-violet portion of the spectrum and in the presence of gaseous oxygen. 14. A method as claimed in claim 13 in which the unexposed areas are selectively dissolved with kerosene* 15* light-sensitive composition according to claim 1 and substantially as hereinbefore described with reference to any of the Examples. 16. A photographic element according to claim 11 and substantially as hereinbefore described with reference to any of the Examples. 17. A method fo preparing a visible image according Attorneys for Applicants. - 36 -