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
  • B41M5/124—Duplicating or marking methods; Sheet materials for use therein using pressure to make a masked colour visible, e.g. to make a coloured support visible, to create an opaque or transparent pattern, or to form colour by uniting colour-forming components
  • B41M5/128—Desensitisers; Compositions for fault correction, detection or identification of the layers

Definitions

• the invention relates to a desensitizing printing ink for pressure-sensitive copy sheets which have a very good desensitizing effect and a correspondingly good resistance to yellowing.
• Pressure sensitive copy sheets generally consist of the combination of an upper and a lower sheet.
• the underside of the upper sheet is coated with microcapsules, in which a colorless or dark-colored, electron-donating leuco dye is enclosed.
• the surface of the lower sheet is coated with the electron-accepting color developing agent.
• the two types of leaves are placed so that the coated surfaces touch each other.
• a pressure such as that of a ballpoint pen, typewriter or the like is applied to these sheets so that the microcapsules break under this pressure and the capsule oil containing leuco dye penetrates into the color development layer, thereby causing the color development reaction which forms the record .
• a middle sheet coated on its upper side with the color developing agent and on its underside with the microcapsules containing leuco dye, one or more times between the upper sheet and the arranged on the bottom sheet allows multiple copies to be made simultaneously.
• the desensitizing ink can usually be on the tops of the middle and bottom sheets, i.e. be applied to a surface coated with the color developing agent.
• oil-based desensitizing inks for typographic printing and solvent-soluble desensitizing inks for flexographic printing and for special purposes a UV hardening type desensitizing ink are used.
• Desensitizing agents are, for example, cationic quaternary ammonium salts (for example dodecyltrimethylammonium chloride) from JL-A 3921/1958, tertiary amines with two polyethylene oxy radicals (for example N, N-di-polyoxyethylene ethylimine) from JL-A 29546/1971, polyoxyethylene ethylenestero the JL-A 38201/1972 and polyethylene glycol alkylphenyl ether), for example polyethylene glycol nonylphenyl ether) from JL-A 8288/1974.
• Such compounds are commonly used as desensitizing inks used in printing with the high-pressure process (rubber relief printing, flexographic printing or gravure printing).
• desensitization printing inks are inadequate desensitization effects, yellowing of the printed surface due to the influence of light, etc.
• desensitization printing is usually used in the printing of characters and lines in the wet offset printing process.
• a printing ink with which desensitization printing is possible using two-color wet offset printing devices In wet offset printing, dampening water is applied to the hydrophilic transfer image part, then the printing ink is applied by the inking roller to the oleophilic printing image part which has not been dampened by the dampening water. This printing ink is then transferred to a sheet through a printing blanket, which is why a strongly oleophilic printing ink is required for such prints.
• this oleophilic printing ink has the disadvantages that the printed sheet surface often shows an uneven printing image due to insufficient supply of the printing ink, or that the moistening device and the non-printed section of the sheet, due to the penetration of printing ink into the dampening water due to the emulsification that occurs is polluted.
• the object of the invention is to produce a desensitizing printing ink with a better desensitizing effect and greater resistance to yellowing and to make it possible to use it in the wet offset printing process.
• At least one of the compounds of the general formulas is used as the desensitizing printing ink: selected propylene oxide addition compound. is used, wherein a, b and c are each an integer of at least 1, R 'is one of the groups alkyl, alkenyl, aryl, substituted alkyl, substituted alkenyl and substituted aryl, and n is an integer of at least 1.
• the glycerol-propylene oxide addition compounds according to the invention preferably those with an average molecular weight below 7000, have a very good desensitizing effect.
• Glycerol-propylene oxide addition compounds are quite different in their solubility in water and viscosity, and the solubility in water increases with decreasing average molecular weight.
• glycerol-propylene oxide addition compounds with an average molecular weight below 600 completely dissolve in water. With an average molecular weight of 1000 the solubility is 30g per 100g water and with an average molecular weight above 3000 it is below 0.1g per 100g water. If the average molecular weight is above 7000, the viscosity becomes so high that the viscosity of the desensitizing ink becomes disadvantageously large.
• the glycerol-propylene oxide addition compounds according to the invention can be used as desensitizing printing inks when printing with typograph, flexographic, gravure printing devices and the like. be used. Those with an average molecular weight of 1000 to 7000 are preferably suitable for wet offset printing and enable long-term printing.
• the propylene oxide addition compounds of aliphatic alcohol or aromatic phenol, the propylene oxide addition compounds of formula (II), preferably those with a Average molecular weight below 8000 show a particularly good desensitizing effect.
• the propylene oxide addition compounds of alphatic alcohol or aromatic phenol are very different in terms of their viscosity, and those with an average molecular weight of 1500 to 8000 are particularly suitable for desensitizing printing inks. With an average molecular weight below 1500, the viscosity becomes lower; but above 8000 higher. It is therefore advisable to control the viscosity of the ink accordingly by adding a viscosity-increasing agent or a diluent when producing the desensitizing printing ink.
• the desensitizing printing ink according to the invention is produced using the propylene oxide addition compound of the formulas (I) and / or (II), pigment and binder as base component and additions of lubricants to prevent lubrication, wax compound, oxidation inhibitor etc.
• the pigments used in the preparation according to the invention are inorganic pigments, for example titanium dioxide, zinc oxide, barium sulfate, magnesium carbonate, calcium carbonate, barium carbonate, magnesium hydroxide, talc, etc.
• the binders are polymer binders, for example ketone resins, polyamide resins, maleic acid resins, phenolic resins, alkyd resins , Melamine resins, urea resins, etc.
• a varnish is usually produced by dissolving a binder in the desensitizing agent with heating, adding a pigment to this varnish and uniformly, for example in a three-roll mill is kneaded to form the color. It is advantageous to use 20 to 60 parts by weight of desensitizing agent, 10 to 40 parts by weight of pigment and 10 to 40 parts by weight of binder.
• the desensitizing ink was made as follows:
• a varnish was prepared from 20 parts by weight of maleic acid resin, added to 50 parts by weight of glycerol-propylene oxide addition compound and dissolved in 150 minutes at 150 ° C. 20 parts by weight of titanium dioxide and 10 parts by weight of calcium carbonate were added to the varnish. The mixture was stirred sufficiently with the mixing machine and then kneaded uniformly in a three-roll mill.
• the desensitizing ink of the composition shown below was prepared in the same manner as in Example 1.
• the desensitizing ink of the compositions below was prepared in the same manner as in Example 1.
• the desensitizing ink was prepared in the same manner and in the same amounts as in Example 1. with the proviso that a glycerol-propylene oxide addition compound with an average molecular weight of 300 was used in place of the glycerol-propylene oxide addition compound with an average molecular weight of 1000 of Example 1. .
• the desensitizing ink was prepared in the same manner in the same amounts as in Example 2. with the proviso that the glycerol-propylene oxide addition compound having an average molecular weight of 600 was used in place of the glycerol-propylene oxide addition compound having an average molecular weight of Example 2.
• the desensitizing ink of the composition shown below was prepared in the same manner as in Example 2.
• the desensitizing ink was prepared in the same manner with the same amounts as in Comparative Experiment 1, with the proviso that polyethylene glycol nonylphenyl ether (number of moles of ethylene oxide addition: 1) was used instead of the propylene glycol in Comparative Experiment 1.
• the desensitizing ink was prepared in the same manner with the same amounts as in Example 3 - with the proviso that polyethylene glycol nonylphenyl ether (mole number of ethylene oxide addition: 12) was used instead of the glycerol-propylene oxide compound of Example 3.
• the desensitizing ink was prepared in the same manner, in the same amounts as in comparative experiment 1, with the proviso that dodecyltrimethylammonium chloride was used instead of the propylene glycol in comparative experiment 1.
• a sheet printed with a desensitizing ink and an upper sheet (FW40T) (manufactured by Jujo Paper Co., Ltd.) Were placed so that the coated surfaces of the sheets touched each other.
• the multi-layered stack of sheets was written on with a typewriter. The color development was evaluated.
• a sheet was irradiated under a carbon arc lamp using a Fade-O-Meter (Toyo Seiki Seinaku-Sho Co., Ltd.) for 10 hours.
• the yellowing resistance of the surface printed with the desensitizing printing ink was measured.
• the desensitizing ink was prepared as follows: First, a varnish was prepared from 20 parts by weight of maleic acid resin added to 55 parts of nonylphenol-propylene oxide addition compound having an average molecular weight of 1,500, dissolved in 30 minutes at 150 ° C. 25 parts by weight of titanium dioxide were added to the varnish. The mixture was ge with the mixer sufficiently stirred and kneaded evenly in a three-roll mill.
• the desensitizing ink of the composition shown below was prepared in the same manner as in Example 6.
• the desensitizing ink of the composition shown below was prepared in the same manner as in Example 6.
• the desensitizing ink of the composition shown below was prepared in the same manner as in Example 6.
• the desensitizing ink was prepared in the same manner in the same amounts as in Comparative Experiment 5, with the proviso that polyethylene glycol nonylphenyl ether (mole number of ethylene oxide: 1) was used instead of the propylene glycol in Comparative Experiment 5.
• the desensitizing ink was prepared in the same manner and in the same amounts as in Example 8, with the proviso that polyethylene glycol nonylphenyl ether (mole number of ethylene oxide: 12) was used instead of the n-butyl alcohol-propylene oxide addition compound having an average molecular weight of 8,000 in Example 8.
• the desensitizing ink was prepared in the same manner and in the same amounts as in Comparative Experiment 5, with the proviso that dodecyltrimethylammonium chloride was used instead of the propylene glycol of Comparative Experiment 5.
• the desensitizing ink was prepared in the same manner and in the same amounts as in Comparative Experiment 6, with the proviso that a nonylphenol-propylene oxide-ethylene oxide addition compound having an average molecular weight of 1,400 was used instead of the n-butyl alcohol-propylene oxide addition compound having an average molecular weight of 4,500 in Example 6 .
• Table 2 shows the preferred properties of the desensitizing inks of the invention, i.e. the colors according to comparative experiments 5. to 8. either give a very good desensitizing effect or a very good yellowing resistance, while the color according to comparative experiment 9. has the disadvantage that wet offset printing with this ink causes difficulties. In contrast, all the colors according to Examples 6 to 8 give a sufficient desensitization effect, very good yellowing resistance and very good printability in wet offset printing

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• Color Printing (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (2)

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Citations (5)

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• 1982
  • 1982-02-12 US US06/348,309 patent/US4431450A/en not_active Expired - Lifetime
  • 1982-02-15 AU AU80482/82A patent/AU543612B2/en not_active Ceased
  • 1982-02-18 DE DE8282101229T patent/DE3264821D1/de not_active Expired
  • 1982-02-18 EP EP82101229A patent/EP0058944B1/fr not_active Expired

Patent Citations (9)

Non-Patent Citations (1)

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