US2873207A

US2873207A - Diazotype reproduction material and method

Info

Publication number: US2873207A
Application number: US489439A
Authority: US
Inventors: Ralph P Weegar; Henry C Unkauf
Original assignee: Dietzgen Co Eugene
Current assignee: Eugene Dietzgen Co
Priority date: 1955-02-21
Filing date: 1955-02-21
Publication date: 1959-02-10
Anticipated expiration: 1976-02-10

Description

Feb. 10, 1959 R. P. WEEGAR ET AL 2,873,207

DIAZOTYPE REPRODUCTION MATERIAL ND METHOD Filed Feb. 21, 1955 mvENToRs: RALPH P WEEGAR HENRY C. UNKAUF United States Patent DIAZOTYPE REPRODUCTION MATERIAL AND METHOD Ralph P. Weegar, Villa Park, and Henry C. Unkauf,

Chicago, Ill., assignors to Eugene Dietzgen Co., Chicago, Ill., a corporation of Delaware Application February 21, 1955, Serial No. 489,439

12 Claims. (Cl. 117-34) This invention relates to a diazotyp'e reproduction material and method o-f manufatcure. More particularly, it relates to the provision of a light-sensitive diazotype layer on aniimpervious organic surface of a photographicbase material, especially in the production of a dimensie-nelly stable photographic reproduction material.

Water and organi-c solvent-impervious organic surfaces such as those on polyester-filled glass and cotton fabrics, as commonly employed in the form of sheets in the drafting and printmaking ield, pose diflicult problems in the application and fixation thereon of other substances, particularly materials which provide photographic lightsensitive layers.

In the provision of photographic light-sensitive layers on base materials, an absorbent surface is commonly treated with a solution of light-sensitive components whichV serve to reproduce a desired image; Thus, for example, diazotype reproduction media are produced by treating an absorbent surface with a solution` containing azo dye components in an uncombined form. The most commonly used base material is paper, and the components are usually in aqueous solution. Sucient penetration is obtained to insure bonding ofthe paper and the sensitizing composition, and the ultimate dye image. Cellulose esters and ethers are also in common use as base materials, and they are impregnated with a sensitizing solution by the addition of penetrating or swelling agents which have a solvent action on the base material, to insure the necessary bonding.

The prior methods are, however, unsuitable for coating or impregnating` water and organic solvent-impervious surfaces, there being insufficient bonding with the base material to provide a uniform layer of the sensitizing components which is permanently bonded and is resistant to wear and abrasion. Furthermore, the dye images reproduced on the surface by exposure and'development have little permanency, and in order to prevent easy removal of the images, it is necessary to overcoat them with a transparent coating. Even such a coating on, for example, polyester-impregnated glass cloth, is easily scratched, chipped and otherwise damaged in ordinary handling, shipping, and storage.

There' are a number of advantages in the use of water and organic solvent-impervious base materials, especially those having a polyester surface, and it is therefore highly desirable to provide reproduction materials which include these materials together with a light-sensitive layer.

It is therefore an object of the invention to provide a new and improved diazotype reproduction material and method of manufacture.

A particular object is` to provide a reproduction material which includes a base having a polyester surface and a light-sensitive diazotype layer thereon.

A further object is to provide a dimensionally stable diazotype reproduction element which furnishes excellent uniform permanent reproduction and which is resistant to the various conditions encountered. An additional object'is to supply a reliable and effective method for providngay light-sensitive diazotype layer on a liquid-impervious polyester surface of a photographic base material. The impervious surface referred to absorbs substantially no water or organic solvent, so that it is unreceptive to aqueous and organic. solvent solutions,` for all practical` purposes, and there will be no or only insubstantial adherence or binding of the solutions and their ingredients to the surface.

Another object is to coat an impervious polyester surface employing a principally non-aqueous organic solvent solution of a light-sensitive diazo compound.

Still another object is to provide a diazotype reproduction material having a base of a polyester-filled tracing cloth, such as a polyester-filled glass or cotton fabric, and the like, and a strongly adherent diaz-otype layer. Polyester-filled glass tracing cloth, commonly referred to as photo-template glass cloth, provides a dimensionally stable reproduction material.

An additional object is to provide a method of preparing a polyester surfaced body having a design on the surface.

Yet another object is to provide a diazotype coat on a photographic base material having the desired properties of transparency or translucency, little color, storage stability and resistance to chemical and physical attack under the conditions normally encountered.

Other objectsinclude the manufacture and application of new and improved coating compositions, andy coats and coated base materials, and the provision of new and useful methods. These and other objects and advantages of theinvention will appear on consideration of the specication taken in conjunction with the attached drawing, in which the single figure is a broken perspective View of photo-template glass cloth provided with a diazotype layer or coat, according to a preferred embodiment of the invention.

The invention provides a photographic reproduction material which includes a base material having an impervious unsaturated polyester resin surface, and a coat of a light-sensitive diazo compound and a cellulose ester or ether. To furnish a satisfactory bond with the polyester surface, a bon-ding coat of an amine-formaldehyde resin is included between the polyester surface and the diazo layer or coat.

A method for providing a diazotype layer on anV impervious unsaturated polyester resin surface is provided in the invention, which method includes providing on the polyester surface a coat of an amine-formaldehyde resin and a solvent-soluble material serving to increase the solvent sensitivity of the coat While retaining its adhesiveness, and coating the resulting coated surface with an organic solvent solution of a diazo compound and a cellulose ester or ether.

rlhe base material provided with a coat of an amineformaldehyde resin forms the subject matter of copending application, Serial No; 489,438, filed February 2l, 1955, by Ralph P. Weegar and Henry C. Unkauf, which is incorporated herein by reference and made a part hereof as fully as if set forth herein in its entirety.

As `disclosed in the above copending application, it has been found that amine-formaldehyde thermosetting resins exhibit very good adhesion to polyesters, in particular, polyester-filled fabrics, such as glass or cotton fabrics, represented by the tracing cloths in common use inthe drafting and printmaking field.

The invention has particular reference to the unsaturated polyester resins, as the class is defined on pages S20-524 of Modern Plastics Encyclopedia, issue/vol. 32, No. 1A, 1954. These resins are condensation products of dibasic acids and glycols, prepared in part from an unsaturated dibasic acid, such as maleic or furnaric acid, and a glycol, suchV as ethylene glycol. The linear'polyesteris Patented Feb. l0, 19t-39:u

cross-linked with a polymerizable monomer, a monomeric vinyl type compound such as vinyl acetate, methyl meth acrylate and styrene, to provide a thermoset solid. Illustrative of the4 polyester resins coated in the invention are the Paraplex polyester-styrene resins (Resinous Prod-v ucts & Chemical Co.), such as P-l3 (flexible grade), P-43 (rigid grade) and P47 (semi-rigid grade). In the preparation of flexible tracing cloth, an exemplary com- .position for filling the fabric is a mixture of P-13 and P-47 in a weight ratio on the order of l to 4. These impervious polyester materials are resistant to the conditions encounteredin the production and use of photographic reproduction media.

The amine-formaldehyde resin may be a melamine, urea, urea-melamine, alkylated urea, acetylene diurea, or triazine type formaldehyde resin, for example. Preferably, a urea-modified melamine formaldehyde type resin is employed, such as Uformite MU56 (Resinous Products & Chemical Co.). Other `representative resins are Uformite MM-SS, a melamine resin, and MX-61, a triazine type resin. The resins are employed in heat-convertible form and are cured or thermoset on the polyester surface.

The cured amine-formaldehyde resin may be and frequently is resistant to the solvents which it is desired to use in the subsequent application ofa photographic sensitizing composition, such as alcohols, ketones and esters, and incompatible with the other constituents of the sensitizing composition. The resin is therefore ntodied to provide a coating to which a sensitizing layer will adhere properly without destroying the adhesion to the polyester surface. Thus, in addition to the amineforrnaldehyde resin, the coating composition and resulting coat according to the invention include a solventsoluble material serving to increase the solvent sensitivity of the coat while retaining its adhesiveness. The preferred solvent-soluble materials are the esters and ethers of cellulose, such as cellulose nitrate, ethyl cellulose, and cellulose acetate, and s hellac.

The resin coating compositions contain the described ingredients in solution in a suitable volatile organic solvent, lower alphatic esters being preferred as exhibiting good compatibility. The compositions should also includea curing catalyst, such as an acid. The base material is coated and thus rendered receptive to the sensi tizing composition by applying the solution to the surface of the material, removing solvent, and curing, preferably at a temperature of about 220-300" F.

It is further preferred to overcoat the amine resin coat, to increase its receptivity to the outer diazo-containing coat. The overcoat contains shellac and a member of the class of cellulose ethers and esters, such as ethyl cellulose, cellulose acetate, and nitrocellulose. The over coat is applied in volatile organic solvent solution, e. g., in a lower aliphatic alcohol or ester, the solvent is rcmoved, and the overcoat is cured, preferably at 220-300 F. Both the first coat and the overcoat are preferably cured together.

The sensitizing composition may be applied at any time after the overcoat, as described in more detail subsequently. The sensitized product prepared in this man ner will then consist essentially of the base material and three coats, films or layers on a surface thereof. lt will be understood that these ,coats will merge and extend into adjacent areas at their inner faces due to penetration, diffusion, and the like during application and curing or hardening.

While the proportions of the components of the amine resin or first coatings are subject to some variation de' pending upon the particular components and the properties sought, it is preferred that the amine-formaldehyde resin be present in a major proportion of the content of the amine resin and solvent-soluble material. Preferably, the solvent-soluble material, e. g., cellulose ester, cellulose ether or shellac, is present in a proportion of about 4. -80% by weight of the amine resin, and it is further preferred that the proportion be about 15-60%.

To improve the properties of the amine-formaldehyde resin coating, an alkyd resin, in particular, a non-oxidizing pure phthalic alkyd resin, may be incorporated into the compositions. The alkyd resins are preferably cured or thermoset pure phthalic alkyd resins modified with a non-drying oil acid, especially those of the glycerol phthalic anhydride type. Thus, for example, the alkyd resins may be the reaction products of phthalic acid or halogenated phthalic acid with a trihydric alcohol such4 as glycerol or other alcohols having three or more hydroxyl groups, or their hydroxyalkyl ethers, modified with i a nondrying oil acid such as the acids of coconut oil,

castor oil, cottonseed oil, olive oil, and the like. The preferred resin is a cured coconut oil acid-modified glycerol phthalate resin. When the alkyd resin is mixed with the heat-convertible amine-formaldehyde resin and the mixture is cured on the polyester surface, the resins adhere strongly and have a very pale color which is retained during and after curing.

In this preferred composition, the alkyd resin is employed in an amount equivalent to about Sil-200% by weight of the amine-formaldehyde resin, ldepending on the particular properties sought. An especially advantageous coat on phototemplate glass cloth is obtained when about ISO-200% by weight of alkyd resin is used, based on the amine resin. Employing both resins, the proportion of solvent soluble material is as described above for the amine resin alone, but the proportion is based instead on the combined weight of the alkyd and amine TCSIUS.

In the above first overcoat, which is applied over the amine resin or amine resin-alkyd resin coat, shellac is the predominant ingredient, about l050% by weight based on the shellac of cellulose ester or ether being included, with l5-25% of the latter being further preferred.

It may also be of advantage to provide a second overcoat, on the surface of the first and between it and the sensitizer coat. This embodiment is that illustrated in the drawing. The second overcoat contains an acrylic ester resin and a cellulose ester or ether, preferably nitrocellulose. The most useful acrylic esters are the methyl and ethyl esters of acrylic acid and methacrylic acid. The resins employed belong to the class of soft resins soluble in petroleum hydrocarbons. Ethyl acrylate appears to provide the most suitable resin. An exemplary resin is Acryloid F-lO (Resinous Products & Chemical Co.), a mineral thinner soluble acrylic ester resin.

The second overcoat preferably contains a. Vmajor weight proportion of the cellulose derivative, based on the total of the latter and the acrylic ester resin. It is further preferred that the proportion of acrylic ester resin be about 25-50% by weight based on the cellulose derivative. The second overcoat is applied to the first overcoahafter curing the latter, in a volatile organic solvent solution of the polymerized acrylic ester and the cellulose derivative, preferably in a lower aliphatic ester. The coated material is then dried to remove volatiles, preferably at about 15C-175 F.

The polyester surface thus coated and rendered receptive to the sensitizing composition is provided with an outer layer or coating of a light-sensitive diazo compound and a cellulose ester or ether, by applying the components in an organic solvent solution. A clear, colorless film-forming cellulose ether or ester is ernployed, such as ethyl cellulose, cellulose acetate, and nitrocellulose.

An important phenomenon cooperating in the invention is that although the films of the cellulose derivatives are not alone pervious to ammonia and water vapor, and to the developing solutions, so that a diazo layer cannot be overcoated satisfactorily with them, the thin films are suiciently pervious when mixed with the diazo com-y those which are N-rnono or (li-substituted `on the undiazotized amino groups, with or without aliphatic substitution on .the benzene ring. Also included are resinous condensation products of aldehydes, such as formalde- `hyde, with these light-sensitive `diazo compounds, and the p-amino phenyl sulfones of the diazo compounds. The boron tritluoride, the stannous chloride, the cadmium chloride, `and `thezinc chloride double salts of the afore- `mentioned light sensitive `organic solvent soluble 'diazo compounds are included. Specic examples of such jcompounds which are usedin the `production `of diazotype images of high contrast are the diazo derivatives of p-amino-N-methyl aniline, p.-amino-N-di-methyl aniline, p-amino-N-ethyl aniline, p-amino-N-di-ethyl aniline, pamino-NmethylNethyl aniline, p-amino-N-ethoxy anidine, p-aminoNmethyl-N-ethoxy aniline, p-amino-N- ethyl-N-ethoxy aniline, pamino-N-diethyl-m-toluidine, and 1-amino-3-methyl-4-ethylamino benzene, all in the form of their diazo double salts with zinc chloride, `cadmium chloride, stannous chloride,.or.boron triuoride, or their .diazo p-amino-phenyl sulfones, `or their diazoformaldehyde resinous condensation products.

As coupling components, any compound which will f'function as a coupling component may be employed .either inthe coating composition together with the diazo .compound in order to produce a two-component system, ,or in the developing solution asa color forming developer. In either case, the coupling component selected `iwillibe one which will `produce the desired `color or a combination of coupling components which will produce a multi-color effect. Examples of preferred coupling 4components are: 2,3-dihydroxy naphthalene and its `6- .sulfonic acid derivative, phloroglucinol, methyl Aphloroglucinol, resorcinol, lresorcinol-mono-methyl `ether, di-

-chloro .resorcinol, r11-hydroxy phenyl urea, acetoacetanilide, `acetoacetylcyclohexyl amide, 7-hydroxy naphthaamino-8-naphthol3,6 disulfonic acid, 2,7 dihydroxy naphthalene, l-naphthol-l-sulfonic acid, and l-amino-S- The sensitizing compositions may contain 'the usual `adjuncts ysuch as metal salts, to intensify the dyestuil` image, i. `e., aluminum sulfate, titanium ammoniumfluoride, nickel sulfate and `the like, and acids designed to =retard precoupling such as citric acid, maleic acid, tar- `taric acid, `boric -acid and the like.

.T he diazo composition. can also. advantageously include a V'filler such as colloidal silica, hydrated silica, diatomaceous earth, bentonite, mica and the like. The filler `acts to raise the softening point of the coating, promote development of aprint by inducing porosity, and provide a mat surface.

The sensitizingcomposition is a principally non-aqueous organic solvent solution of the diazo ingredients and .the cellulose ester or `ether. The ingredients are balanced for mutual compatibility and the properties def-sired. The solvent and cellulose derivativeare selected for solubility and are adjusted to a viscosity suitable `for application and which` will properly suspend the ller, and to provide a continuous `ilexible abrasion-resistant iiilm.v The solvents are preferably selected from the `group of-lower aliphatic alcohols, lower aliphatic ketones, lower aliphatic glycol esters and lower aliphatic glycol `ethers, and they are specially `selected to furnish a controlled rate of drying on application to the base material. Thus, thesolvents are `balanced toresult in a drying rate Awhich "is slow 4'enough to avoid condensation orlpic'kup rof water and to avoid ,premature drying lin the rollers -or other equipment, yet rapid enough to dry rapidly and completely in a satisfactory manner after application, furnishing a thin uniform strongly adhering and )nontacky surface coat. For example, a drying rateof 5-10 minutes `at 150-175" F. in commercial coating equipment is provided.

`The primary solvent for the mixture is methanol or ethanol, or acetone or methyl ethyl ketone may be Vsubstituted in whole or in part. The primary solventlis present in a major proportion by `weight of the total 'ofthe organic solvents, preferably in a proportion of -90% of the solvents. The primary solvent 'is blended with a minor proportion, preferably lO-40%, of a higher boil ing alcohol or theequivalent, which serves to Aprevent overly rapid drying with consequent blushing The medium boiling lower aliphatic alcohols `having 4 carbon atoms or more and which are liquid at room temperature, such as butyl alcohol and amyl alcohol, are desirably employed, and they Ymay be substituted in whole or "in part by lower aliphatic glycol esters or ethers, such as the esters or ethers of ethylene glyool, propylene yglycol and glycerine. In a controlled low humidity, normal or isopropanol may be used alone. ln the selection of solvents, due consideration must be given to the solubility of the .cellulose derivative.

rprinting, afsmallamount of a lower aliphatic glycolfsuch as ethylene-glycol, propylene .glycoland glycerine, may

be included to `assist in picking up Water vaporin developing. The proportion of Vglycol is preferably about 1A Ito l part by weight to l part of the cellulose derivative. This function together with'that of the secondary or 4higher boiling solvent is also provided `by `cellosolve esters, such as the lower aliphatic cellosolve esters, preferably -alkoxy ethyl acetate. p

'In the sensitizing composition, the cellulose ether or ester binder is preferably employed in a proportion of about 1A to 5 parts by weightto l part of diazo compound. The reference to diazo .compound does n-ot include the coupling components ,and the adjuncts. About 20 to 20() parts by Weightfofsolvent are employed-per part of diazo compound, so Vthat-the diazo oompoundis present in a proportion of aboutS toil-5% `of the solvents.

About 30to dt'lparts iof'solvent `per'part ofthe cellulose binder areemployed,equivalent to a `proportion'ofbind'er 4'of about 3.3% to A1.6% lbased `on the solvents. 'It-is ordinarily` preferred to incorporateabout 0.5 tto v5 tparts of `filler per part of diazo compound.

The composition includes merely sufficient water to dissolve those components of the diazo system which are insoluble or diicultly soluble inorganic solvents, but not enough to precipitate the cellulose ester `or ether binder, and the proportion of water thus amounts to a maximum of about 3% `byweight ofthe complete sensitizing comi position.

The sensitizing composition prepared'inltheabove manrieris applied to the polyester surface whichhas been rendered receptive thereto by the application of the described amine-formaldehyde resin coat, by brushing,

spraying, bead-coating, rollercoating, silk screeningyor thelike, to provide a thin coat on `the surface. `Thematerial is dried in the'dark, at.ajtemper.ature of fromabout room temperature to about 250 F., the upper temperature being limited bythe stability of the diazo components. An adherent sensitized layer is thus firmly bonded to the polyester surface. Thephotographic reproduction materialrso produced canfbe exposed "to light of `varying intensity in accordance with a `design`to be reproduced thereon, e. g., under a pattern to be'reproduced, and the images developed by exposure to ammonia vapors in the case of the two-component or dry-developing process, or by spraying, dipping, swabbing or sponging with a developing solution in the case of the one-component or moistdeveloping process.

When the original pattern or drawing is produced on a dimensionally stable medium, such as photo-templateglass cloth, the final diazotype reproduction will be an exact true-to-scale duplicate copy of the original. The resulting copy is unaffected by atmospheric moisture and continues to maintain its dimensional stability during handling and storage. The duplicate copy requires no overspraying or lacquering, as there is no rubbing or peeling l,off of the surface, and the image is well protected. The reproduction materials and the resulting prints may be transported and employed in various localities, for example, they have found widespread application in the manufacture of metal templates in the aircraft industry.

The following examples are furnished to assist in providing a complete understanding of the invention, but it lis to be understood that the invention is not limited thereto nor to the specific compositions, proportions and conditions set forth therein, which are given only for purposes of illustration.

Example 1 The following composition is employed to provide an amine-formaldehyde resin layer on an impervious polyester surface:

Urea melamine formaldehyde resin (Uforrnite MU-56) gm 130 5-6 Second RS nitrocotton gm 20-100 Ethyl acetate cc-- 900 n-Butyl acetate- N* l() Phosphoric acid gm-- 4 Example 2 Another exemplary composition is the following: Urea-melamine-formaldehyde resin (Uformite MU-56) gm-- 130 Ethyl cellulose gm-- 20-100 Ethyl acetate CC-.. p 900 n-Butyl acetate cc.- 100 Phosphoric acid s gm 4 The coat is applied as-in Example 1 and is cured for about 5 minutes at Z50-300 F.

Example 3 An additional composition wherein an alkyd resin is included, is the following:

Cured, non-drying oil acid-modified pure phthalic alkyd resin gm 130 Urea-melamine-formaldehyde resin gm-.. 50-130 1/2 second RS nitrocotton gm. 50-150 Ethyl acetate cc 900 n-Butyl acetate rt 100 Ethyl phosphoric acid gm..- 8

The coat is applied as in Example 1 and is cured for about 5 minutes at Z50-300 F.

Example 4 The following is an example of a composition for providing an overcoat on the surface of the coat formed according to Examples 1-3:

8 Bleached, dewaxed shellac gm..- 125 5-6 Second RS nitrocotton gm-.. 15-50 Ethyl acetate cc-- 200 Methanol cc 700 n-Butanol cc Example 5 Another example of a composition for providing an overcoat to further increase the receptivity of the alkyd resin coat is as follows:

Bleached, dewaxed shellac ..-gm

Ethyl cellulose gm-.. 15-50 Ethyl acetate cc 2.00

Methanol cc-- 700 n-Butanol cc-- 100 Example 6 The following composition is applied by roller coating commercial photo-template glass cloth with a layer which is 0.0002-0.0004" thick.

Cured coconut oil-modilied trihydric alcohol-phthalic anhydride alkyd resin (Duraplex ND-77B, Resinous Products & Chemical Co.) -grn-- Urea-melamine-formaldehyde resin (Uformite MU- 56) 9m. 75 5-6 Second RS nitrocotton ..-gm.... 75 Hydrated silica gm-- 5() Ethyl acetate cc-- 900 n-Butyl acetate cc 100 Ethyl phosphoric acid 2m 10 position:

Bleached, dewaxed shellac gm-.. 100 5-6 Second RS nitrocotton gm-.. 20 Hydrated silica gm-.. 50 Ethyl acetate cc 200 Methanol cc 700 n-Butanol cc- The overcoated product is dried at about ISO- F. for tive minutes, and the combined coatings are cured at about Z50-300 F. for ve minutes.

The resulting coated photo-template glass cloth is receptive to a light-sensitive diazotype organic solvent composition, which is applied thereover as described in the subsequent examples.

Example 7 A second overcoat may be applied on the surface of the first overcoat of Example 6. The following composition is applied and dried in the same manner aspthe first overcoat:

(Acryloid F-10) gm- 5-6 Second RS Nitrocotton gm 20-40 Ethyl acetate .cc 600-800 n-Butyl acetate ec-- l00-300 -methoxy ethyl acetate (Carbide & Carbo methyl cellosolve acetate) cc-- 100-300 `Water cc The resulting coated photo-template [glass l'cl'oth is ref ceptve to a light-sensitive diazotype organic solventco'mposition, which is applied thereover as described in the subsequent examples. The complete" photographic-reproduction material or element, lillustratedfin `the drawing, then includes the sheet of .photo'ltemplate `cloth 1, lthe am'ine resin-alkyd Aresin coat adhering to a surface of the cloth, the intermediate shellac rstoverc'oat 3 adhei-ing to the outer surface ofthe resin coat .2, the `intermediate `acrylic ester resin second overcoat! 'adhering to theouter surface of the `shellac overcoat 3, and 4the outer se'nsitizing coat S adhering :to the outer surface of the acrylic ester resin coat 4. The acrylic ester ,resin "Second overcoat 4` may be omitted, so `thatthe sensitizing coat 5 adheres to the outer surface of the shellac Aovercoat 3.

Example 8 lIhis example illustrates the production Aof a (direct (p'ositive image) dimensionally stable sepia intermediate '(second original) print,\am1nonia developed, on phototemplate `glass cloth.

A solution of sensitizer is prepared, having ,the rfollow- -ing composition: i

These ingredients, thoroughly mixed and ltered, are added to the following mixture: t

Methanol cc 8000 n-Butanol cc 1600 Silica aerogel (Monsanto Santocel CX) gms 600 `ethyl cellulose `in methanol (Hercules "N-SO) cc `6000 .t The nal sensitizing solution islstored ina covered crock `until ready for use.

`A roll of commercial plastic-impregnated photo-template glass cloth, 36 wide, 0.005 thick, ZOO-yards long, iswsub-coated according to Example 6er 7 and is then `bead-coated in a layer about 0.000l-0.0002 thick with theabove-described sensitizing solution on acloth llacquering machine of conventional design, dried in the dark, and Wrapped andpackaged in yard length rolls. Using part of one of these rolls, a contact print ismade by means of a carbon arc light and a vacuum frame, on av 3 x A12 section of the sensitizedmaterial. As the original pattern, a 3 x l2 non-dimensioned engineering pencil drawing on plastic-impregnated glass tracing cloth is used.

The resulting sepia intermediate `(or second original print, ammonia developed is an exact, true-to-scale posi- Vtive copy of the original pencil drawing on` glass cloth, p having a verytsmall linear distortion. From this tsecond original copy `can now be made exact true-toscale nondimensioned `metal template, if `the `metal has been sensitized with a positive image printing type of sensitizer- Example 9 This example illustrates the production of a direct (positive image) dimensionally stable blue line print, ammonia developed, on photo-template glass cloth.

A lsolution is prepared, having the following composi tion: t v

1Methanol cc 3500V pn-Butanol cc 250 150y egfsvsgfoe in o Ethylene glycol cc `150 Citric acid gms 100 Zinc chloride gms t Urea fgms 1.00 2,3-difhydroxynaphthalene grns Z 1p+diazofN-ethylfNethoxy aniline, stannous chloride douole salt gms 150 added to the following mixture:

Methanol -c 21000 An-Butan'ol cc` `800 'Hydrated silica 'gms 300 Ethyl cellulose 10% solutionin methanol. cc '3000 A roll of plastic-impregnated photo-template glass cloth, 48 wide, 0.005 thick, 150 yards long, is subcoated according to Example `i6 yor 7 and. is then rollercoatedin a layer yabout 00001-00002 `thick with `the above-described'sensitizing solution on a cloth lacqucring machine of conventional design, dried in the dark, and wrapped and packaged in sheets 4' wide and lin Alengths from 4 to l2'. A 4 x 8 sensitized sheet is selected, and a print is made from a 4 x 8 second original sepia intermediate print on plastic-impregnated glass eloth (made `from a 'non-dimensioned,` vtrue-to-'scale rengirneering `drawing `on photo-template glass .cloth hy the method `described inExample `f5).

The 4resulting blueline `positive copy, `printed :and ammonia developed, is an exact, true-to-scale positive copy `of `the second original sepia intermediate print, `having a very small linear distortion. i

Example 10 `A `solution 'is prepared, having the following corn' position:

A-Metboxy ethyl acetate (Carbide & Carbon methyl cellosolve acetate) cc 2500 Acetone -cc 500 n-Butanol cc A250 Methanol a cc 500 Water cc 300 Oxalic acid f t .t t gms 100 Naphthalene 1,3 ,6-tr' s u l f o ni c acid, (sodium salt) i gms `200 ,pDiazo-N-ethylN-benzyl aniline, cadmium chloride double salt.V gms-- 3.00

These ingredients, thoroughly mixed and filtered, `are `added to the following mixture:

Methanol cc 2000 Acetone cc 2000 Silica aerog-el (Godfrey L. Cabot Cab-O- `Sil) t gms y1100 `Cellulose acetate (Hercules, FM grade,`56% acetic acid content) gms A roll of plastic-impregnated photo-template glass cloth, 42" wide, 0.005 thick, 100 yards long, is subcoated according to Example 6 or 7 and is then rollercoated with the abovedescribed sensitizing solution on a 4cloth lacquering machine of conventionaldesign, -dried a developing solution composed of the following ingredients:

Water ce 4000 Potassium metaborate gms 300 Urea v gms 60 Phloroglucinol gms Resorcinol gms 30 After the print is developed, it is rinsed in water and air dried. The resulting sepia line positive print on glass cloth is an exact, true-to-scale positive copy of the original ink drawing on glass cloth, having a very small linear distortion. From this second original print can now be made exact, true-to-scale copies ou diazo sensitized glass cloth (as described in Example 9), or on metal templates when sensitized with a positive image printing type of sensitizer.

Example Il This example illustrates the production of a direct (positive image) dimensionally stable black line print, semi-moist developed, on photo-template glass cloth.

A solution is prepared, having the following composition:

-Ethoxy ethyl acetate (Carbide & Carbon cello- 10% ethyl cellulose solution in methanol cc 3000 A roll of plastic-impregnated photo-template glass cloth 30" wide, 0.005 thick, and 125 yards long, is subcoated as described in Example 6 or 7 and is then offset roller-coated with the above-described sensitizing solution on a cloth lacquering machine of conventional design, vdried in the dark, and wrapped and packaged in sheets measuring 21/2 x 5'. A print is made on one of these sensitized sheets from a 21/2"x 51 second original moist-developed sepia intermediate print on phototemplate glass cloth produced by the method described in Example l0. For exposure, a carbon are light is used, and the direct process positive print is made by the contact method, using a vacuum frame. The resulting print is developed by swabbing with a sponge moistened with a developing solution prepared as follows:

After the print is developed, it is blotted dry between filter papers, and air dried. The resulting black line `semi-moist developed positive print on photo-template glass cloth is an exact, true-to-scale copy of the sepia interrnediate print on glass cloth, it having a very small linear distortion.

ln the foregoing examples, various combinations of light-sensitive diazo compounds, or light-sensitive diazo compounds and azo coupling components, soluble in the types of organic solvents described, and suitable for the 4preparation of photographic light-sensitive layers, i. e., `which will provide a photographic reproduction, visually 12 reproducing a drawing on exposure to light .and develop ing by undergoing asubstantial color change, can be substituted for the compounds employed. Likewise, the compositions and procedures can be varied in other ways while still providing the results of the invention and falling within its scope.

In this manner, the invention provides a new and iml proved diazotype photographic reproduction material, especially a material useful in applications where dimensional stability is required. The new materials are exceptionally versatile in their application, overcome the prior disadvantages and provide new and improved industrial applications.

What is claimed is:

1.` The method for providing a light-sensitive diazotype layer on an impervious unsaturated polyester resin surface of a photographic base material which comprises providing on said surface a coat of an amine-formaldehyde resin anda solvent-soluble material serving to increase the solvent sensitivity of the coat while retaining its adhesiveness, providing on said coat an overcoat of shellac and a member selected from the class consisting of cellulose esters and cellulose ethers, and applying to the coated surface a coat of a light-sensitive diazo compound and a member of the class consisting of cellulose esters and ethers.

2. The method for providing a light-sensitive diazotype layer on an impervious unsaturated polyester resin surface of a photographic base material which comprises coating said surface with an organic solventsolution of a heat-convertible amine-formaldehyde resin and a solvent-soluble material serving to increase the solvent sensitivity of the coat while retaining its adhesiveness, removing volatiles, coating the coated surfacewith an organic solvent solution of shellac and a member selected from the class consisting of cellulose esters and cellulose ethers, curing the coating, and coating the coated surface with an organic solvent solution of a light-sensitive diazo compound and a member of the class consisting of cellulose esters and ethers.

3. The method for providing a light-sensitive diazotype layer on an impervious unsaturated polyester resin surface of a photographic base material which comprises coating said surface with an organic solvent solution of a heatconvertible amine-formaldehyde resin and a cured nondrying oil acid-moditied phthalic alkyd resin and a solventsoluble material from the class consisting of cellulose esters, cellulose ethers and shellac, removing volatiles, coating the coated surface with an organic solvent solution of shellac and a member selected from the class consisting of cellulose esters and cellulose ethers, curing the coatings, and coating the thus coated surface with an organic solvent solution of a light-sensitive diazo compound and a member of the class consisting of cellulose esters and ethers.

4. The method for providing a light-sensitive diazotype layer on an impervious unsaturated polyester resin surface of a photographic base material which comprises providing on said surface a coat of an amine-formaldehyde resin and a non-drying oil acid-modified phthalic alkyd resin and a solvent-soluble material from the classconsisting of cellulose esters, cellulose ethers and shellac, a lirst overcoat of shellac and a number selected from the class consisting of cellulose esters and cellulose ethers, a second overcoat of an acrylic ester resin and a member selected from the class consisting of cellulose esters and cellulose ethers, and an outer coat of a light-sensitive diazo compound and a member of the class consisting of cellulose esters and ethers.

5. rThe method for providing a light-sensitive diazotype layer on an impervious unsaturated polyester resin surface of a photographic base material which comprises providing on said surface a coat of an amine-formaldehyde resin and a non-drying oil acid-modified phthalic alkyd resin and a solvent-soluble material serving to increase the solvent sensitivity of the coat while retaining its adhesiveness, providing on said coat an overcoat of shellac and a member selected from the class consisting of cellulose esters and cellulose ethers, and coating the coated surface with an organic solvent solution of a lightsensitive diazo compound and a member of the class consisting of cellulose esters and ethers dissolved in a solvent selected from the class consisting of lower aliphatic alcohols, lower aliphatic ketones, lower aliphatic glycol esters, and lower aliphatic glycol ethers.

6. The method for providing a light-sensitive diazotype layer on an impervious unsaturated polyester resin surface of a photographic base material which comprises providing on said surface a coat of an amine-formaldehyde resin and a non-drying oil acid-modified phthalic alkyd resin and a solvent-soluble material from the class consisting of cellulose esters, cellulose ethers and shellac, a rst overcoat of shellac and a member selected from the class consisting of cellulose esters and cellulose ethers, and a second overcoat of an acrylic ester resin and a a member selected from the class consisting of cellulose esters and cellulose ethers, and coating the coated surface with an organic solvent solution of a light-sensitive diazo compound and a member of the class consisting of cellulose esters and ethers, said solvent being a mixture of methanol and butanol and containing a small amount of a lower aliphatic glycol.

7. The method for providing a light-sensitive diazotype layer on an impervious unsaturated polyester resin surface of a photographic base material which comprises providing on said surface a coat of a urea-melamineformaldehyde resin and a coconut oil acid-modified trihydric alcohol phthalate alkyd resin and nitrocellulose, a rst overcoat of shellac and nitrocellulose, a second overcoat of an acrylic ester resin and nitrocellulose, and an outer coat of a light-sensitive diazo compound and ethyl cellulose.

8. A photographic base material having an impervious unsaturated polyester resin surface, a coat on said surface of an amine-formaldehyde resin and a solvent-soluble material serving to increase the solvent sensitivity of the coat while retaining its adhesiveness, an intermediate coat of shellac and a member selected from the class consisting of cellulose esters and ethers, and an outer coat of a light-sensitive diazo compound and a member selected from the class consisting of cellulose esters and ethers.

9. A photographic base material having an impervious unsaturated polyester resin surface, a coat on said surface of an amine-formaldehyde resin and a member selected from the class consisting of cellulose esters, ce1- lulose ethers, and shellac, an intermediate coat of shellac and a member selected from the class consisting of cellulose esters and ethers, and an outer coat of a lightsensitive diazo compound and a member selected from the class consisting of cellulose esters and ethers.

l0. A photographic base material having an impervious unsaturated polyester resin surface, a coat on said surface of an amine-formaldehyde resin and a non-drying oil acid-modified phthalic alkyd resin and a member selected from the class consisting of cellulose esters, cellulose ethers, and shellac, an intermediate coat of shellac and a member selected from the class consisting of cellulose esters and ethers, and an outer coat of lightsensitive diazo compound and a member selected from the class consisting of cellulose esters and ethers.

11. A dimensionally stable diazotype photographic reproduction material comprising photo-template glass cloth, Y

a coat adhering to a surface thereof of an amine-formaldehyde resin and a non-drying oil acid-modified phthalic alkyd resin and a member selected from the class consisting of cellulose esters, cellulose ethers, and shellac, an intermediate coat of shellac and a member selected from the class consisting of cellulose esters and ethers, and an outer coat of a light-sensitive diazo compound and a member selected from the class consisting of cellulose esters and ethers.

12. A dimensionally stable diazotype photographic reproduction material consisting essentially of photo-template glass cloth, a coat adhering to a surface thereof of a urea-melamine-formaldehyde resin and a coconut oil acid-modified trihydric alcohol phthalate alkyd resin and nitrocellulose, a first overcoat of shellac and nitrocellulose adhering to the outer surface of the first-named coat, a second overcoat of 4an acrylic ester resin and nitrocellulose adhering to the outer surface of the first overcoat, and an outer coat of a light-sensitive diazo compound and ethyl cellulose adhering to the outer surface of the second overcoat.

References Cited in the iile of this patent UNITED 'STATES PATENTS 1,756,400 Schmidt Apr. 29, 1930 1,947,160 Holzwarth Feb. 13, 1934 1,997,745 Renker Apr. 16, 1935 2,140,089 Marasco Dec. 13, 1938 2,433,515 Jahoda Dec. 30, 1947 2,606,117 Trojnar Aug. 5, 1952 2,616,803 Ravich Nov. 4, 1952 2,663,640 Reichel et al Dec. 22, 1953 2,698,240 Alles et al Dec. 28, 1954 2,718,476 Eichorn Sept. 20, 1955