Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/025—Duplicating or marking methods; Sheet materials for use therein by transferring ink from the master sheet
  • B41M5/03—Duplicating or marking methods; Sheet materials for use therein by transferring ink from the master sheet by pressure
• • 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
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/14—Production of collotype printing forms

Definitions

• the present invention relates to a new and improved process for forming a printing platefor intaglio and flat printing.
• the carrier or support of the image, design, or lettering to be printed is provided with a tannable or hardenable, image-receptive gelatin layer the thickness of which in the swollen state must not exceed about 0.1 mm.
• Such an extremely thin colloidal layer is first subjected to preliminary tanning or hardening treatment in such a manner that the image, design, or lettering subsequently applied to said pre-tanned or pre-hardened colloidal layer is also subjected to a certain degree of preliminary tanning or hardening. Said preliminary tanning or hardening treatment renders the colloidal layer extremely stable and durable so that it does no longer dissolve even when exposed to the action of boiling water. Provision of such an extremely thin colloidal layer prevents too deep a final image-fixing tanning or hardening and, consequently, too deep an impression of the image, design, or lettering to be printed and, thus, produces especially sharp prints.
• chromic acid or its salts are added to the writing, drawing, or image-forming agent, such as typewriter ribbon, ink or the like.
• a reducing agent capable of reducing chromic acid such as, for instance, hydroxylamine hydrochloride, monomethyl p-amino phenol sulfate or the like, are added to the pre-tanned or pro-hardened, 'very thin tannable or hardenable colloidal layer.
• chromic acid present in the drawing, writing, or image-forming agent encounters the reducing agent present in said layer and is reduced, even in the absence of actinic light, at the marked areas, thereby forming chromic chromate or other chromium salts of lower degree of oxidation.
• the course of said reduction reaction is revealed by a brownish discoloration of the originally yellow image, design, or lettering. Said reduction reaction proceeds, even in the dark, much quicker than the reaction caused by exposing the layer to light. It is advisable to apply the reducing agent only after the image, design, or lettering has been drawn or written on said colloidal carrier and after any required corrections have been made.
• the imagefdesign, or lettering to be printedl is first drawn or written on a piece of paper by means ofabichromate containing writing, .or drawing, .or other imagerforrning agent and said original is then transferred to the moistcried and slightly driedpre-tanned or pm-hardened, very thin colloidal layer to form thereon an image, designer lettering in reverse, in easesaid colloidal ,printingsurface is used in direct printing.
• the entire image, design, or lettering is coated with a sol tion, for instanc of -4 g. efhydrazine hyd oc oride,
• Said solution almost instantaneously, causes tanning or hardening of the image, design, or lettering.
• Printing surfaces according to the present invention are far superior to other known printing surfaces in that they tenaciously retain the greasy image-fanning ma terial, that they will not tone-up during use, that the images, designs, or lettering produced thereon will not fall oif during use, that they will withstand considerably more pressure without distortion than heretofore produced images, designs, or lettering, that said surfaces will permit erasure without the use of liquids and without showing the erasure, that they have a remarkably long service life, that they will produce prints of extraordinary sharpness and definition, even in long runs, and that they have other greatly improved characteristics.
• tanning refers to a treatment of the water soluble colloidal layer whereby its water solubility is reduced and it is hardened.
• the preliminary tanning or hardening treatment is preferably effected by means of formaldehyde. Care must be taken not to cause too strong a tanning or hardening of the colloidal layer because, in this case, the colloidal layer will accept the printing ink not only at those places where the image, design, or lettering has been produced 'by subsequent tanning or hardening of said colloidal layer but also at those other places exposed to such excessive preliminary hardening.
• the colloidal layer must also not be too soft because then it is not suitable for the production of sufficiently long runs due to a disintegration of the colloidal layer on printing.
• Subsequent tanning or hardening to fix the image, design, or lettering to the colloidal layer requires a degree of tanning or hardening which prevents the image, design, or lettering from dissolving and disintegrating in the course of the normal printing procedure.
• the pre-tanned or pre-hardened, very thin colloidal layer does not contain a reducing agent.
• the image-forming agent for instance, the typewriter ribbon contains potassium bichromate. Writing with said bichromate containing ribbon on the colloidal layer produces thereon the image.
• Final image-fixing tanning or hardening of the colloidal layer at those places where the image to be printed has been written on is effected when moistening the colloidal layer and the image thereon with a reducing agent, such as hydroxylamine hydrochloride.
• the pre-hardened colloidal layer is first moistened with a solution of said reducing agent.
• a solution of said reducing agent When writing on such a layer with a typewriter ribbon containing potassium bichromate therein, tanning or hardening of the image sets in instantaneously.
• instantaneous production of an image, design, or lettering on a colloidal layer for subsequent printing was not possible.
• the most preferred agents for producing a printable image, design, or lettering on a prehardened colloidal layer are alkali bichromates and hydroxylamine salts although other agents, as explained hereinbefore, may also be used.
• a gelatin layer on a supporting backing, partially hardening said layer by treating with a tanning agent, printing on said layer with an image forming agent, containing a compound seleoted from the group consisting of chromic acid and salts thereof, coating said printed layer with an agent capable of reducing said image forming agent, the reducing agent being selected from the group consisting of hydroxyl amine salts and monomethyl p-arninophenol sulfate, whereby the portions of said printed layer contacted by said image forming agent are hardened and caused to shrink.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Printing Methods (AREA)
• Duplication Or Marking (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=27209643

Family Applications (1)

Country Status (6)

Cited By (2)

Families Citing this family (2)

Citations (11)

• 1950
  • 1950-03-28 DE DED1923A patent/DE832544C/de not_active Expired
• 1951
  • 1951-08-18 DE DED10057A patent/DE920045C/de not_active Expired
• 1953
  • 1953-12-02 BE BE524758D patent/BE524758A/xx unknown
  • 1953-12-04 FR FR1102969D patent/FR1102969A/fr not_active Expired
  • 1953-12-04 GB GB33864/53A patent/GB750260A/en not_active Expired
  • 1953-12-05 CH CH325101D patent/CH325101A/de unknown
• 1954
  • 1954-01-28 US US406876A patent/US2962961A/en not_active Expired - Lifetime

Patent Citations (11)

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