US2418304A - Adhesive photosensitive material - Google Patents

Description

April 1, 1947. v M. R. HuTcHlsoN 2,418,304

ADHESIVE PHOTOSENSITIVE MATERIAL Filed Dec. V22, 1943 EMULS/0N 0F F//VHL Y SENS/WWW ense f/mrsfr no//fsn/E @mss EMME/vr #mam/E wwf INVENTOR M/LL fl? Refsf HurcH/s o/v y ATTORNE S Patented pr. 1, 1947 UNITED STATES PATENT OFFICE 2,418,304 ADHESIVE PHoTosENsIrIvE MATERIAL Philadelphia, Pa.

Application December 22, 1943, Serial No. 515,282

2 Claims.

'In my APatent No. 2,311,547, granted February 16, 1,943, I have disclosed a process for producing templates and the like, which process includes the preparation of three diierent laminated units, each comprising a substantially rigid backing elea suriace layer of sheet material (paper), which, though hygroscopic in character, is rendered immune to plane dimensional variations', regardless of moisture conditions, by being bonded to said rigid non-hygroscopic backing element, Vby means of ,a water-proof heat-settingadhesive. 'gliliefirst4 `unitfisthe image or drawing unit, consisting of a :metal backing element, surfaced with plainfpaper, on which the template design is Adrzutfnin pencil. Thesecond unit is the negative unit, consisting of la'glassV backing element,` `surffaced ,with photographic paper, on which `a reflex negative .is produced from the drawingunit. The third unit ,is the positive unit, consisting of a graphic paper, on which a positive print is made from thereex negative unit, .said metal backing element `becoming the finished template after being machined in accordance with the template design, reproduced thereon.

` The photographic paperemployed forthe negative `and positive units, `is prepared in the usual way; that isto sayybylooping the paper transversely and drawing it over the surface of an aqueouslphotographicemulsion solution and then leading the coated paper over "a `roller vpast a, `fdoct'or bar,1ocated at a fixed distance yfrom `the surffaceof the paper, whereby an emulsionoating., "of a deiinite uniform thickness, is produced onthe paper.` The coating of the water-proof `heat-setting adhesive is applied tothe `plflir in thesame way, the. coating being applied `in l-icjuid orsolution form. In each instance, after the application `of the coating,`the paper Vis led. through ,a drying alley Vfor a period of time long enough to dry and to solidify the applied coating. AInmy prior patent, the .described procedure contemplates the Iapplication of lthe adhesive coating prior to the application of the emulsioncoating,

fitbeing thought, at thetime, that, byfollowing `such sequence, it would be easier `to apply the emulsion,coating-because of thestiffening of the paper produced by thepreviously applied adhesive coating.v Y

As thus prepared, the photographic 4paper is laid rwithrfitsadhesive face in contact with lthe surface of the backing element, to whichgit is `to `be applied (glass in one instance and metal irr` the l pther ,1ar1dthen bonded t0 thezbact-riefelement. runder heat and-pressure. noweverfiamy prior 2 patent, the adhesive coating on the photographic paper is not lrelied upon alone for bonding the paper to the backing element, but the latter itself is first prepared with an adhesive coating for contact with the adhesive coating of the paper, ment, which is non-hygroscopic in character, and

it being thought, at the time, the two coated -surfaces would produce a\rmer bond than could 4be secured if only one of the two `surfaces Were coated.

10 As explained in my prior patent, the adhesives itheheat-settingf of the adhesive, said bond wi-ll Abe unaffected by the heat generated during `the `template machining operations, which may" develop a rtemperature of between l`500"`.l. and 600 and, Vin-e'nild'ition, the adhesive must besui- Y 'ciently'water-proof, dilute-aeid-proof and dil-utemetal 'backing element, surfaced with photoalkali-proof that, when-the photographic paper is bonded `to the backing element, by the heatsetting of the adhesive, said `bond will be unaffected by the solutionsused in the processing of the-photographicemulsion, after the printing exposure. iFor 4the negative laminated unit, the adhesive must likewise be suiciently water-proof, dilute-acidproof and dilute-alkali-proof that, when fthe photographic paper is` bonded to the glass backingele'ment, by the'heat-setting of the fadhesive, saidlcond will be unaffected bythe solutions nsed the processing of the photographic emulsion," after the printing exposure;` and, moreover, `the adhesive, `once heat-set, must possess the requisite light-transmitting properties. The

adhesive for the negative laminated unit `should also, preferably, -be of such character that the bond between thephotographic paper and-the' glass backing-element may be" broken, either by 40 hprolenged watersoaking or-by the use of solvents tioned, the ladhesives'must be of the `heat-setting *Variety (whether thermo-plastic or :thermo-set- `.ti'ng or "bothhno" cold-setting adhesive "having "been foundwhich-would answer the requirements.

`lVIyl'oresent invention is concernedV solely with the'` preparation of thenegative and positive-laminated units, presenting an improved adhesive -.photographic; paper, suitable for the purpose'.V

As onexfeature of -my invention, I have discoveredthat'better resultsy may be obtained by omitting the adhesive coating from K,tllefhacklng l element and applying an adhesivecoating only,4 to

or Vafter the coating step.

and finally rolling up the double-coated paper' with the adhesive face in direct contactwith the emulsion face.

In following the proceduredescribed in my issued patent, I found that, whenv the adhesive coating is rst applied to the paper base, the

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When the adhesive photosensitive material is prepared in accordance with my present invention, the adhesive and emulsion coatings may be brought into direct contact, Without any deleterious eiect, in Winding up the material into a roll, no liner or separator being needed. This, of course, is an added advantage of considerable importance 'from a practical standpoint.

I should, perhaps, add that the photographic Aemulsion which is employed, in the practice of my present process, is thesame as that described in my priorpatent above identified. In other j words, the emulsion solution is prepared so that lthe emulsion coating of the photographic paper,

as used` forboththe negative and positive units,

Vwill have an initial sensitivity greater than that required for the service intended, so as to comcoated paper, unless prevented from doing so,`Wil1 curl or assume a tube-like form when the paper loop is moved into and out of contact with the surface of the emulsion in the applying trough; This curling or -tubing effect is probably caused by the water-proof character of the already applied and solidified adhesive coating, on one side of the paper, and the non-water-proof or waterabsorbing character of the opposite or emulsiontaking side. In other words, when the emulsion coating is applied, the paper will absorb water from the highly aqueous emulsion solution and expanden one side, as it is free to do, but, because of the presence of the Water-proof adhesive coating, the paper cannot expand on the other side.;v Henceit becamevnecessary` to use mechanical means to hold the paper straight, as vit is drawnv through the emulsion trough and later through the long drying alley--a very difficult operation and one which is far from satisfactory. This diiiculty of curling does not arise when,

according tothe present invention, the emulsion coating is applied and dried before theapplication of the adhesive coating. The explanation seems to be that,in applying the emulsion coating onto plain or, unlacquered paper, any expansion of the paper by water absorption from the aquei .ous emulsion `solution is uniform throughout, and

that, when vthe adhesive coating later is applied, nowateris absorbed by the paper, due to the `non-aqueous character of the adhesive solution, andhence no Vexpansion of the paper takes place.

As another feature of the invention and one of great importance, I have discovered that, by

.the Vreverse sequence above described, the emulsion coating will not be fogged or otherwise contaminated by the adhesive coating, either during a InV other words, I have discovered that, whereas the emulsion coating,before it becomes dried or solidified, is susceptible to fogging or contamination lby the previously applied adhesive coating, the emulsion,

coatinghas no such susceptibility, in its dried or solidifiedcondition.v The explanation is probably this: If the emulsion coating is applied after the adhesive coating, Vthe emulsion solution (bethe solvents used in Apreparing the adhesive solution, and this, whether the solvents are present ihiliquidor vaponforrn during the'` coating and drying periods." Y l 'l inghighly aqueous) penetrates through the paper 1,.

-print from fthe'vreex negative pensate for whatever loss of sensitivity takes place in the heat-setting of the adhesive and subsequent conditioning when the photographic paper is bonded to the-backing element. yNotwithstanding such supersensitivity of the photographic emulsion, my present processor applying the emulsion coating rst and the adhesive coating last, avoids any fogging or contamination of the emulsion, either during the coating and drying periods or, later on, during the plasticizing or heat-,setting period.

Referring now to the drawings: Fig. 1 is a sectional view, greatly' enlarged, depicting a portion of a sheetfof adhesive photo 'sensitive material as preparedfor'making up the negative laminated unit.v .'Ifhe material consists "of `a paper base |"(about.003" in thickness) having, on one-side, a uniform coating 2 (ofthe usual thickness) oflan unexposed light-sensitive emulsion and, on the other side, a uniform coating 3 (about .001 in thicknesspf a waterproof heat-setting adhesiva' these coatings pos` sessing the characteristics and'being applied in the manner above described.

Fig. 2 is a sectional view, greatly enlarged,` depicting the adhesive photosensitive material of Fig. 1 bonded, by the heat-setting ofthe adhesive coating, toa glass backing element 4 (about .25" in thickness 'as to template sizes up to 4 x 6 and thicker for larger ones), this papersurfaced glass element being the laminatedunit Iwhich isl used in making a reflex negative print from the'original drawing unit. l Fig. 3 isasectional view, greatly enlarged, depicting a portion of a sheetpfyadhesiye photo; sensitive material, asV prepared for the making vup of the positive .lamin'atedunit l lThe material consists of a paperbase V5 (about .003",inthickness) having,VY on one side, ai'uniform .coating (ofthe-usual' thickness); of an unexposed light'- Vsensitive emulsion and, on thepther. side, a'uniform coatingl (about .Qlfin' thickness) of'a. water-proof heat-,setting adhesive, theservcoatings possessing the characteristics and beingxapplied in themanner above described. ,Y The sheet ofaadhesive photosensitive'material 11's bonded, by theQheat-setting of the adhesive,

toda metall backing Heminente (about .065" iny thickness as to `normal' sized templates), this paper-surfaced metal element Vbeing theV laminated unitvwhich isused in making a positive print for Fig. 2 and which, as before explained, is later converted, by machining,- into the finalV template.;

rHaving thus described -my invention, what I `'claim is:' 1 l 1. As an article of manufacture, adapted'for use in-afphotographic process for vproducing on -'as'urfa'cef-of-"the material `to befabricat'dfan accurate replica of some particular image, a laminated unit comprising a glass backing element and a photosensitive material adhered thereto, said photosensitive material comprising a flexible sheet material coated on one side with a first-applied unexposed light-sensitive photographic emulsion, and on the other side with a later-applied Water-prooi heat-setting adhesive, said photographic emulsion being immune to contamination by said adhesive, the heat-setting of the adhesive in bonding, the sheet material to the glass backing element having the eiect of reducing the sensitivity of the photographic emulsion, and the initial sensitivity of the emulsion being suii'iciently greater than that necessary for the service intended to compensate for said reduction in sensitivity.

2. As an article of manufacture, adapted for use in the fabrication of a template or the like suitable for metal Working operations, a laminated unit comprising a metal backing element possessing the requisite thickness and rigidity to become the finished template and capable of being machined in accordance With the template design, and a photosensitive material adhered thereto for the reproduction of the template design thereon, said photosensitive material comthe sensitivity of the photographic emulsion, and

the initial sensitivity of the emulsion being sumciently greater than that necessary for the service intended to'compensate for said reduction in sensitivity.

MILLER REESE HUTCHISON.

REFERENCES `CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 770,421 Derepas Sept. 20, 1904 1,605,699 Bourgess Nov. 2, 1926 2,147,772 Kallander Feb. 21, 1939 2,000,528 Linderman May 7, 1935

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