Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/02—Printing inks
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C1/00—Forme preparation
  • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
  • B41C1/1091—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by physical transfer from a donor sheet having an uniform coating of lithographic material using thermal means as provided by a thermal head or a laser; by mechanical pressure, e.g. from a typewriter by electrical recording ribbon therefor
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks

Definitions

• This invention relates to an improvement in the artof planographic printing and it comprises directly delineating on a dry cellulosic printing surface a printing image with a water-immiscible material which is sp ntaneously sorptive by said gagainst theattritional effects of the dampening and inking operations of planographic printing and it also comprises an image-forming material which is spontaneously sorptive for the printing surface and ,is preferentially ink-receptive and persistently retentive of printing ink contacted therewith against the attritional forces inherent in planographic printing operations, said imageformer being chosen from the groups hereinafter listed and being either a material directly applicable to the printing surface or a composition capable of leaving thereon a substantially waterimmiscible residue exhibiting such properties; and it further comprises the method of delineating the image by subjecting the residue of the composition on the printing surface to selective ultraviolet irradiation, and it also comprises the combination of a planographic printing
• a further and greater objection to this treatment is that the integration with a cellulosic printing surface of greasy image-forming materials by heat or time coincidentally tends to set" or integrate therewith finger marks or other greasy accidental or adventitious smears, and it is an advantage of the discovery upon which this invention is based that, immediately after the delineation of the image upon a suitable cellulosic printing surface with image-forming material of the type hereinafter set forth orwhen the said materials comprise a volatile component or vehicle-immediately after the evaporation of said component or vehicle, the said surface may be dampened with water or preferably with an acidic dampening solution such as is described in my Patent No.
• This discovery provides a method of pianographic printing from unified cellulosic plates, preferably having a low lateral water-diffusion rate, wherein such plates are prepared for printing by the direct-image delineation upon the substantially water-immiscible and is preferentially wettable by usual lithographic ink, whereby substantially longer editions are obtainable by direct or offset planographic printing than can be obtained under otherwise like conditions by like means from usual greasy image-forming materials similarly applied to such plates.
• an image-forming material adapted to direct delineation upon the unified cellulosic printing surface of a planographic printing plate, which material is spontaneously sorptive by said surface, is physically retained substantially intact over the delineated image area, is water-immiscible, and is preferentially ink-wettable; and its adhesion to said face, persisting when the latter is subsequently saturated by an aqueous dampening fluid, and its internal cohesion and its adhesion to printing ink are severally substantially greater than is the internal cohesion of a usual lithographic printing ink suitable for use therewith, in direct or offset planographic printing.
• spontaneous sorptivity by unified cellulosic surfaces of image-forming materials of the type hereinafter described, and the resistance of said materials to displacement from said surfaces, by the combined effects of dampening fiuids applied thereto and printing ink rolled thereover under printing conditions, are great in some measure of inverse proportionality as the free fatty acid content of said materials and the lateral water-diffusion rate of the substance of said surfaces are both diminishingly low.
• irradiated areas which may. be, and conveniently are, determined by a negative transparency-is rendered preferentially ink-wettable and retentive of printing ink against the attritional effects of the usual dampening and printing operations and whereby the non-printing areas, notwithstanding the presence thereon of the said potential image-forming material, remain preferentially water-wettable and'require no more than the usual dampening operation to become ink repellent.
• It also provides a method of preparation of cellulosic plates for planographic printing which consists solely in directly delineating, on the printing face thereof, an image with a spontaneously-sorptive image-forming material of I the character hereinafter described, dampening the said face and rolling lithographic ink thereover whereby to selectively ink said image.
• the cellulosic printing plate is first treated according to my copending application Serial No. 312,390, whereby the lateral water-diffusion rate is lowered, so as to be not more than 25 millimeters in 4 hours; and is then, except for the choice of image-forming material, prepared for printing in the following manner: to wit, the hereinafter described imageforming material is directly applied to the dry unified cellulosic printing face of the plate, a preferably acidic dampening solution is subse-' quently applied to the entire area thereof whereby the non-image areas are selectively moistened, and then without further preparatory treatment the ink rollers are passed over said entire surface area and the ink will adhere only to the image areas. Printing is thereafter carried out in the usual direct or offset planographic manner, ex
• gum arabic is preferably and advantageously omitted from the dampening solution.
• a directly-delineated planographic printing image In order to have printing utility in the field of office duplication and to be commercially practical, a directly-delineated planographic printing image must be capable of yielding at least one thousand clean facsimile copies without suffering appreciable disintegration or degradation. By this is meant that there should be no gross degradation of the copy at the one-thousandth impression as compared to the first impression.
• Spontaneously-sorptive image-forming materials having the hereinafter-stated characteristics when applied to suitable cellulosic surfaces of the character described in my copending application Serial No. 161,970, filed September 1, 1937, and in my above-identified copending continuation thereof, Serial No.
• 312,390 are capable of yielding commercially practical results under planographic printing conditions, and the materials of the preferred examples hereinafter given have been found to yield, under practical offset printing conditions, clean facsimile copies in editions of from two to more than fifteen thousand imipressions.
• planographic image-forming materials must vary widely in physical characteristics to meet the requirements of the several variant modes of image delineation.
• a crayon composition must be a solid of a wellrecognized character, capable under frictional attrition of leaving tracings of its substance upon the printing surface; while, at the other I extreme, a. writing composition suitable for pen work must be a fluid of suitablylow viscosity and high surface tension to flow readily from the nib or drawing pen and yield a clean fine line, and it must comprise a suitably volatile vehicle.
• the characteristics common to the imageiorming materials of this invention, in terms of the requirements they must fulfill, may be stated as follows: (1)
• the image-forming material or composition as applied to, or as residual on, the unified cellulosic printing face of a planographic plate must be substantially water-immiscible at least at room temperatures, since otherwise the image would of necessity be impaired by the dampening to which the plate is of necessity subjected before inking and during printing; and the image on the said printing lace must remain physically intact in'the sense that it must maintain a surface coverage over the entire original image area since, as pointed out above, the capacity for reproduction of an image upon a cellulosic printing" face depends soley upon the persistence thereon of the imagefoiming material; (2)
• the image-forming material or composition must a component which is-or which as the result of suitable treatment may become--preferentially wet 'by, and retentive of, usual lithographic printing ink since a, portion of the printing ink components of the hereinbe
• the substance of said printing face-such sorp-' tive bond must, notwithstanding the subsequent dampening of vthe cellulosic substance of said printing face, remain substantially the original image area since age would "work sharp" as the image area decreased or would fatten as the image area increased; and both the internal cohesion of the image-forming material and its sorptive bond to said substance, when the latter is subsequently dampened, must be severally substantially greater than both the adhesion of the said material to, and the internal cohesion of, the printing ink used therewith; and said sorptive bond must offer effective resistance to degradation by the attritional forces brought to bear under printing conditions; (4)"I'he spontaneously-sorptive image-forming material or composition as applied to, or as residual on, the surface of the plate must have substantially greater resistance to displacement therefrom under under printing conditions than have otherwise similar usual greasy image-forming materials under like conditions of application and printing.
• the life of a pianographic direct-image must be such as to yield an edition of at least one thousand clean facsimile copies, as stated, and for the present purposes the direct-image life of usual greasy image materials on the printing face of cellulosic plates and integrated therewith to prolong their life is, under optimum printing conditions, accepted as an adequate and satisfactory criterion of minimum commercial utility.
• mere contact of the usual greasy image materials with cellulosic printing surfaces does not furnish an image of satisfactory life within the purview of this invention.
• Usual greasy image-forming materials generally comprise a component high in free fatty acid to react with the substance of the printing surface, a pigment to renderthe delineation readily visible, .andv commonly one or more components adapted either to increase the water-immiscibility or to increase the'ink-retentiveness or both, and further adapted to, impart to the whole the desired consistency.
• compositions of spontaneously-sorptive image-forming materials requires a component which is ink-re- I ceptive and rete'ntive, which component may be such as has been used heretofore for the same purpose in greasy image-forming compositions; and it also requires a component which has a cohesion for unified cellulosic surfaces and particularly for such surfaces having a high oxidation-products content.
• components in some instances may be one and the same, although in general the particular requirements of viscosity-or plasticity, as the same may be-are best met by using two or more components complementary to each other in that one may impart the desired high spontaneous sorptivity, another the desired ink-receptivity and -retentiveness and, if required, the third may serve as a transient solvent only or as a permanent vehicle imparting to the whole the desired viscosity or plasticity and the necessary internal cohesion.
• Usual or greasy image-forming materials are 1 for the present purposes defined as embracing all image-formers as commonly used in planegraphic printing from metal to form a directprinting image (in contrast to'a photographic image) comprising essentially a free fatty acid, a soluble fatty acid soap or a fatty acid ester such as stearin and the vegetable waxes; where- ,as, by contrast, image-formers falling within the purview of this invention should not contain they may comprise an insoluble metal soap, such as a copper, barium, iron, or lead stearate, oleate or other soap, or may comprise an unsaturated fatty oil polymerized by oxidation, irradiation or halogenation as by chlorination for instance.
• image-forming material and image-former unless qualified by usual, greasy or fatty or unles clearly indicated by the context to embrace both the prior direct-imageformers and those of this invention, are used herein with reference to those materials or compositions which exhibit spontaneous-sorptivity for normally dry cellulosic surfaces comprising or consisting of, a non-fibrous continuum of substantially pure celluloseand which further exhibit, when and as originally applied to and residual as thin deposits on said surfaces'and after subsequent dampening thereplication, Serial No. 312,390; (2) An image is I delineated on the printing face of said plate with the image-forming material under test and in a mode appropriate thereto, and any volatile vehicular component thereof, it such there'be, ir allowed to evaporate at room temperature; (3)
• spontaneous sorptivity and spontaneously sorptive as used herein is meant an adhesion or adhesiveness for unified cellulosic printing surfaces, whether by absorption in or adsorptionion said surfaces, which is effected I by more contact of image-formers therewith and without the necessity of heating or a long time to the axis of the brayer so that its progress is one of pure rotation in a direction at right angles to the previous inking passes, in such manner as,
• unifying continuum as herein used is meant that non-fibrous form of cellulose resulting from gelatinization, by chemlcal reaction in the case of amyloid parchment and by mechanically accelerated hydration in the case of so-called glassine or greaseproof paper, which continuum not only surrounds the residual fibers as a coating but also serves to unify the whole by contact fusion, thus moreor less completely filling the. interstices and forming a non-fibrous continuum from any part of the structure to any other part thereof.
• cellulosic continuum Another example of a cellulosic continuum is found in a sheet of regenerated cellulose.
• unified cellulosic material any sheet material composed essentially of substantially pure cellulose, thevwet strength of which is primarily dependent upon that of a component non-fibrous continuum which may,
• oxidation-products content is meant the total effect of oxidation of the celluiosic component or components of a unified celluiosic material, such as parchment, glassine, greaseproof or regenerated cellulose, as represented by the arbitrary numerical sum of the values obtained for oxycellulose in terms of copper number (expressed in grams) and for hydrocellulose in terms of cold alkali solubility (expressed in percentage) by the more sensitive of the known methods.
• planographic printing is used herein, in the commonly accepted sense-which includes rotary offset printing, to denote that printing process in which the surface of the printing plate is substantially plane and in which the printing image is substantially in the plane of the printing surface; that is to say, the printingimage is neither raised appreciably above nor sunk much below the plane of the printin image.
• the expression celluiosic printing plate is herein used to denote a celluiosic structure, such as is more fully described in my Patent No. 2,134,165 and my copending application, Serial No. 161,970, characterized by a printing face of substantially pure unified celluiosic material and an integral backing adapted to restrict the swelling of the said printing face to a direction normal thereto when, under printing conditions, said face is dampened.
• the expression surface is used herein in a broadly inclusive three-dimensional sense as commonly used, and not in the strictly twodimensional sense as used in scientific reference to molecular surface phenomena, for instance.
• the lateral diffusionrate of water in unified celluiosic material is defined as the height (expressed in millimeters) to which distilled water rises in a sheet of said material over a period of 4 hours when the edges thereof are sealed against absorption of water in any convenient manner and when the sheet is suspended over a quiescent bath of said water at room temperature under the following further conditions: (1) the lower end of the sheet is maintained below the level of the bath, this being conveniently accomplished by folding a bit of sheeted block tin over the bottom edge; (2) the machine direction of the sheet is to be parallel to the surface of the bath; (3) the portion of the specimen above the bath is surrounded by moisture-saturated air; (4) a marker having been inscribed at the edge of the sheet, the sheet to exactly this mark and then raised by an amount slightly greater than the expansibility of the sheet in a direction normal to the machine direction thereof; (5) the sheet isv suspended thus for 4 hours, at the end of which time the rise from the marker is measured off in millimeters.
• irradiation as herein used is meant irradiation with ultraviolet light at an at a distance and for a time sufllcient to bring about the desired change in the substance being treated.
• irradiation with ultraviolet light at an at a distance and for a time sufllcient to bring about the desired change in the substance being treated.
• free fatty acid, greasy or fatty are herein used to embrace th essential fatty acid component of usual image-formers required for direct-image delineation on zinc and stone for planographic printing, which component comprises essentially a free fatty acid, a soluble fatty acid soap or a fatty acid ester such as stearin and vegetable waxes; but they do not embrace such acids as are comprised in an insoluble metal soap such as copper, barium, iron or lead stearate. oleate or other soap, or such acids when polymerized by oxidation, irradiation or halogenation as by chlorination for instance.
• the objectionable eflect of the inclusion of free fatty acid in an image-former when used on celluiosic printing surfaces may be made qualitatively manifest by drawing a set of lines on a celluiosic printing surface with a one per centum solution of abietic acid in acetone, another set of lines with a one per centum solution of oleic acid in acetone, and a third set of lines with a solution of one-half per centum abietic acid and onehalf per centum oleic acid in acetone; and, after the evaporation of the acetone, by exposing a portion of each of the three said sets of lines to irradiation by ultraviolet light for 15 to 30 minsets of lines delineated with oleic acid alone and with abietic and oleic acids together do not acl cept ink in the unirradiated portion at all and in the irradiated portion the oleic acid has become slightly ink-receptive while the abietic acid 'admi
• the spontaneously-somtive image-forming materials of this invention arenot of utility on celluiosic plates modified by component metal salts or siliceous materials, but only to say that a particular merit of the image-forming materials of this invention is in the substantial advantage derived from the use of said materials in combination with printing plate faces composed of substantially pure unified cellulose, and particularly when said cellulose has a high oxidation-products content, over the use with like printing faces of usual greasy imageforming materials.
• Spontaneously sorptive image-forming materials may comprise any of the following substances either alone or incombination, as will be further noted.
• Oil-soluble dyestufis Dyestuffs of the types above listed are ink-recaptive and -retentive, and also spontaneously sorptive. and may be used for direct-image delineation in a solvent vehicle. Lump oil aniline black may be used for direct-image delineation without a solvent vehicle.
• Abietic acid Gums and resins of the types above listed are ink-receptive and -retentive, and either are spontaneously sorptive or, as in the case of mastic, kauri and elemi, may be so modified by heating in admixture with morpholine as to become spontaneously sorptive.
• Vegetable oils such as cottonseed, rapeseed. linseed, linoleic and the like, are not imageformers in the unsaturated state but may be rendered useful as such by halogenation or irradiation and may be used in the unsaturated state as photogenic image-formers and be selectively irradiated as a thin deposit from a volatile vehicle on a cellulosic printing surface.
• Synthetic resinous substances such as coumaron indene resin, chlorinated oleyl alcohol, highly chlorinated diphenyl, sucrose octa-acetate, urea formaldehyde resin of the Beetle type,
• Insoluble metal soaps such as a copper, barium, iron or lead stearate, oleate, palmitate or the.
• Waxes are useful for the present purposes mainly as viscosltyor plasticity-augmenting components of an image-forming composition; but shellac wax represents the most outstanding exception as it has been foundto be in and of itself a good image-former; while candilla (candelilla) wax, selected as representing a wax having a high acid number, when heated in admixture with morpholine has also been found to be a good image-former, and it has been found to be true of beeswax vwhen bleached and subsequently irradiated in situ as a thin solvent residue on a unified cellulosic printing surface.
• candilla (candelilla) wax selected as representing a wax having a high acid number, when heated in admixture with morpholine has also been found to be a good image-former, and it has been found to be true of beeswax vwhen bleached and subsequently irradiated in situ as a thin solvent residue on
• an imageformer As in combination with a substance which is itself spontaneously sorptive, but need not necessarily be ink-receptive, whereby the viscosity, plasticity or internal cohesion of. the com: position is adjusted to a particular mode of image delineation.
• the following substances have been found useful in image-forming compositions when said substances were in consociative combination with ink-receptive and -retentive image-formers appropriately chosen from the foregoing lists.
• Solids such as ethyl ortho-benzoyi benzoate, octadecyl alcohol, octadecane diol and ortho-hydroxydiphenyl, though not of and in themselves ink-receptive, have been found useful in crayon compositions comprising ink-receptive substances pont) and triacetin, though not in and of themselves ink-receptive, have been found to be useful in more or less viscous compositions comprising ink-receptive substances chosen from those hereinabove listed.
• Volatile liquids such as ethylene glycol monobutyi ether and diethylene glycol monobutyl ether. though not in and of themselves ink-receptive, have been found to be useful in imageimprinting compositions comprising ink-receptive' substances listed.
• the mix may be eifected by heating and stirrins until uniform, in any convenient manner. Milling between tightrolls, however, is not recommended.
• said image-former having spontaneous sorptive adhesion for unified cellulose and being sufiiciently free from free fatty acid to permit spontaneous bonding with said surface by mere contact therewith without the application of heat orlapse of time.
• An image-forming composition for inking typewriter ribbons comprising a stearate of nigrosine and butyl ortho-benzyl benzoate.
• An image-forming crayon composition comprising a stearate of nigrosine and ethyl ortho"- benzoyl benzoate.
• An image-forming imprinting ink composition comprising ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, orange shellac and a stearate of nigrosine.
• water immiscible image former preferentially wettable by lithographic printing ink and exhibiting on a unified cellulosic surface an adhesion for such ink greater than the internal cohesion of such ink, said image-former havin spontaneous sorptive adhesion for unified cellulose and being sufiiciently free from free fatty acid to permit spontaneous bonding with said surface by mere contact therewith, and immediate dampening, inking and printing, without the application of heat or lapse of time.
• a direct image-forming crayon for use on a unified cellulosic planographic printing surface, said crayon comprising waterimmiscible image-forming material preferentially wettable by lithographic printing ink and exhibiting an adhesion for such ink greater than the internal cohesion of such ink, said crayon material having spontaneous sorptive adhesion for unified cellulose and being sufficiently free from free fatty acid to permit spontaneous bonding with said surface by mere contact therewith without .the application of heat or lapse of time.
• a direct image-forming crayon for use on a unified cellulosic planographic printing surface, said crayon comprising water immiscible image-forming material preferentially wettable by lithographic printing ink and exhibiting on a unified cellulosic surface an adhesion for such ink greater than the internal cohesion of such ink, said crayon material having spontaneous sorptive adhesion for unified cellulose and being sufficiently free from free'fatty acid to permit spontaneous bonding with said surface by more contact therewith without the application of heat or lapse of time.
• the crayon containing an oil soluble dye and a solid vehicle therefor.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Optics & Photonics (AREA)
• Manufacturing & Machinery (AREA)
• Printing Plates And Materials Therefor (AREA)
• Printing Methods (AREA)

Priority Applications (6)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (6)

Cited By (8)

• 0
  • NL NL61481D patent/NL61481C/xx active
  • IT IT385713D patent/IT385713A/it unknown
  • BE BE439773D patent/BE439773A/xx unknown
• 1940
  • 1940-01-04 US US312391A patent/US2342713A/en not_active Expired - Lifetime
  • 1940-07-30 GB GB12354/40A patent/GB541671A/en not_active Expired
  • 1940-08-29 FR FR876208D patent/FR876208A/fr not_active Expired

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