Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N3/00—Preparing for use and conserving printing surfaces
  • B41N3/03—Chemical or electrical pretreatment
  • B41N3/038—Treatment with a chromium compound, a silicon compound, a phophorus compound or a compound of a metal of group IVB; Hydrophilic coatings obtained by hydrolysis of organometallic compounds

Definitions

• This invention relates to lithographic printing plates of the kind that are used, for example. in photolithography and carry a grain to which an image is applied.
• Such plates are usually made of, or at least have a surface of, zinc.
• the grain is usually formed by a cumbersome and lengthy mechanical treatment.
• the invention By means of the invention it is possible to produce a plate having a number of striking advantages in comparison with a mechanically grained plate.
• the grain is fine and deep and allows an increased number of prints to be taken from the plate.
• the fine grain takes the design well, so that the time usually spent by an artist in touching up the design before printing is considerably reduced.
• the excel lent dot-formation that is produced allows a finer Screen to be used.
• the phosphate coating does not oxidize in the air and therefore need not be covered when not actually in use. The plates can be'cleaned and used again more often, because the phosphate coating tends if anything to thicken them, whereas mechanical graining wears their surfaces away.
• etching solution made by adding 1 ounce of concentrated nitric acid to gallon of water-and then saturating the diluted acid with alum. After this treatment it is rinsed in cold water wiped again with the cleaning preparation and again rinsed in cold and hot water. The surface is then ready for the phosphate treatment, which consists in immersion for from 30 to 40 minutes in a solution made by dissolving in gallons of water, 30 lbs. of a powder containing (by weight) 77% zinc dihydrogen phosphate, 19% ferrous sulphate and 4% zinc carbonate. This solution is kept at a temperature of about to 200 F. After the immersion the plates are rinsed and dried.
• a method for graining a zinc lithographic plate which comprises treating the zinc plate with a cleaning solution, washing the said plate, immersing the said plate in an etching solution, washing the said plate, and then immersing the a cleaning solution comprising phosphoric acid,
• the method of graining a zinc lithographic plate which comprises treating a zinc plate with a cleaning solution comprising phosphoric acid, butyl alcohol and sulphonated lorol, then rinsing the said plate with water, immersing the said plate in an etching solution comprising nitric acid and alum, washing the said plate, and then immersing the said plate until suitably grained in a heated solution of zinc dihydrogen.
• a cleaning solution comprising phosphoric acid, butyl alcohol and sulphonated lorol

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Printing Plates And Materials Therefor (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10378296

Family Applications (1)

Country Status (4)

Cited By (1)

• 0
  • NL NL44488D patent/NL44488C/xx active
• 1935
  • 1935-12-21 GB GB35488/35A patent/GB467610A/en not_active Expired
• 1936
  • 1936-12-11 US US115445A patent/US2126181A/en not_active Expired - Lifetime
  • 1936-12-18 FR FR815191D patent/FR815191A/fr not_active Expired

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