JP3015823B2 - Desensitizing ink for pressure-sensitive copying paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a desensitizing ink for pressure-sensitive copying paper. Furthermore, the present invention relates to a desensitizing ink for pressure-sensitive copying paper, which reduces or eliminates the function of a color developing agent for developing a colorless color developing agent.

[0002]

2. Description of the Related Art An electron-donating almost colorless dye precursor (hereinafter, referred to as a color former) and an electron-accepting acidic substance (hereinafter, referred to as a color former).
It has been known for a long time that a colored image can be obtained by a contact reaction with a developer. As a specific use of this phenomenon, for example, pressure-sensitive copying paper (US Pat.
505470 and 2505489) and heat-sensitive recording paper (JP-B-45-14039).

In general, developers for pressure-sensitive copying paper include inorganic solid acids such as activated clay, acid clay, attapulgite, zeolite, bentonite, silica and aluminum silicate.
Novolak-type phenolic resins and salicylic acid derivatives, or polyvalent metal salts of salicylic acid derivatives are used, especially polyvalent metal salts of salicylic acid derivatives have good color-forming properties,
Widely used in the market. In recent years, many salicylic acid resins or polyvalent resins thereof have been developed for the purpose of improving the color development speed of conventional phenolic resin-based developers and the poor water resistance of colored characters of salicylic acid-based developers. Metal salts have been proposed as developers. Examples of these color developers include polyvalent metal salts of salicylic acid and a co-condensation resin such as α, α′-dialkoxy-p-xylene (JP-A-62-176).
No. 875, No. 62-178387, No. 62-
178388, 63-53092, 6
Nos. 3-159082 and 63-160877), a polyvalent metal salt of a resin obtained by reacting a styrene derivative with a salicylic acid derivative having an aromatic substituent (JP-A-63-186729), Polyvalent metal salts of a resin obtained by reacting a benzyl halide with a salicylic acid derivative having a substituent (JP-A-63-254124), and other resin polyvalent metal salts described in JP-A-63-289017. And the like are known. Further, a polyvalent metal salt compound comprising a salicylic acid, a rosin, and a polyvalent metal compound has also been disclosed as an organic developer (Japanese Patent Application Laid-Open No. 2-563).

In general, as pressure-sensitive copying paper, an upper sheet having a color former layer containing microcapsules enclosing a color former on a support, and a lower sheet having a developer layer containing a color developer on the support. Paper, if necessary, a separate type in which a developer and a color former are used in combination with a middle paper provided with a developer layer and a color former layer on the front and back of the support, and a developer and a color former in the form of a single layer or a multi-layer The self-type provided on the same surface is used.

[0005] Characters colored by the reaction between a color former and a developer are recorded. However, depending on the form of the slip, it may not be possible to read the characters as colored characters. In the market, it is inked and printed on the surface of a layer containing a color developer.

[0006] The desensitizing ink is prepared by mixing a desensitizing agent with an ink resin serving as an appropriate adhesive, a pigment such as titanium oxide or calcium carbonate, a solvent for dissolving or diluting the resin or the desensitizing agent, or the like. Desensitizing inks for letterpress, offset, flexo, etc. are commercially available depending on the form of the ink or the means of printing. UV-curable desensitizing inks are also commercially available to increase the drying speed.

These desensitizing inks are described in US Pat. No. 2,777,805, JP-B-44-27255, JP-B-45-21448, and JP-A-46-22651.
JP-A-46-29546 and JP-A-47-3820
No. 1, No. 48-4050, No. 49-4484
JP, JP-A-19-19647, JP-A-49-2300
No. 8, No. 49-23850, No. 58-381
No. 19, JP-A-47-32915 and JP-A-48-325.
Nos. 6805 and 49-43708 and 49-43.
Nos. 72009 and 49-77709, 49
-77710, 49-15513, 4
Nos. 9-83509, 63-74681, 63-41184, 63-94879,
The details are described in JP-A-63-139781, JP-A-2-20777, German Patent Application (OLS) 2343800, JP-A-23590759, JP-A-2361856, and the like.

[0008] Recently, the method of passing printed pressure-sensitive copying paper through a machine to read characters or marks by the machine has been increasingly used. Typical reading devices include optical reading devices such as OCR, OMR, and label bar codes.

[0009] Desensitizers generally used in desensitizing inks include:
A relatively viscous fluid at room temperature is used so that it does not penetrate the paper layer after printing and does not transfer to a portion where color needs to be formed, and the effect of inhibiting color formation is increased. Therefore, the surface printed with desensitizing ink is
Generally, the stickiness is relatively large. Therefore, when the pressure-sensitive copy paper subjected to the desensitization printing is passed through a machine such as a reading device, the paper feeding state is poor due to the stickiness of the desensitized printing surface, which causes a reduction in workability.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a desensitizing ink which does not impair the machine-feeding suitability of pressure-sensitive copying paper and which is excellent in printing suitability and desensitizing effect.

[0011]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, the above object has been achieved by using a desensitizing ink containing a desensitizing agent and a fluororesin. And completed the present invention.

The fluororesin used in the present invention includes ethylene tetrafluoride resin, ethylene tetrafluoride-hexafluoropropylene resin, ethylene tetrafluoride-perfluoroalkyl vinyl ether copolymer resin, and ethylene tetrafluoride-ethylene copolymer. Polymer resins, ethylene trifluoride resins, vinylidene fluoride resins, polyvinyl fluoride, ethylene trifluoride-ethylene copolymer resins, and the like are preferred, with ethylene tetrafluoride resins being particularly preferred.

The amount used is 0.1% in the desensitizing ink.
-30% by weight, more preferably 0.5-10% by weight. If it is less than this, it is difficult to obtain the desired machine paper-feeding suitability, and if it is too large, it is difficult to print other colored ink on desensitized printing, pencil, ballpoint pen,
Poor writing performance with a felt-tip pen or the like, or a loss of balance with fountain solution on a printing press, resulting in adverse effects such as a decrease in printability.

The desensitizer mentioned herein includes, for example,
The following specific examples can be given. Quaternary ammonium salts such as dodecyltrimethylammonium chloride and octadecylammonium chloride; high molecular weight amines such as dodecylamine; 2,4,4-trimethyl-
Substituted oxazolines such as 2-oxazoline; reaction products of a diamine or polyamine derivative having a cyclic structure in a molecule such as xylylenediamine or N-aminopropylpiperidine with an alkylene oxide; polyoxyethylene alkylamine, polyoxyethylene alkyl ether; Polyoxyethylene alkyl phenyl ether, polyethylene glycol, polypropylene glycol, polyoxypropylene alkyl amine, polymer having glutamic acid-γ-alkyl ester residue, spiroacetal diamine, N- (aminoalkyl) -lactams, amines There are glycidyl ether adducts and the like. Among them,
As the desensitizer of the present invention, a compound obtained by adding an alkylene oxide having 3 or more carbon atoms to an ammonia or amine compound is particularly effective.

The desensitizing ink according to the present invention contains a desensitizing agent and a fluororesin, and may contain various other components as necessary. Other components included in the desensitizing ink of the present invention include materials for general printing inks. For example, ketone resin, polyamide resin, maleic acid resin,
Natural or synthetic polymer compounds such as phenolic resin, epoxy resin, alkyd resin, melamine resin, urea resin, nitrocellulose, ethylcellulose, butyral resin, polyvinyl alcohol, gelatin, shellac (these are 0 to 50 in desensitizing inks). % By weight, preferably 5%
-30% by weight. ), Inorganic substances such as barium sulfate, talc, kaolin, titanium dioxide, magnesium carbonate, calcium carbonate, aluminum hydroxide, magnesium hydroxide, calcium oxide, barium hydroxide, beryllium oxide, bentonite, and organic bentonite (these are desensitizing inks). 0-60% by weight, preferably 0.1-50% by weight), vegetable oils such as linseed oil, tung oil, soybean oil and cottonseed oil (these are 0-50% by weight in the desensitizing ink,
Preferably, it is contained in an amount of 0 to 30% by weight. ),methanol,
Organic solvents such as ethanol, ethyl acetate, toluene, hexane, methyl ethyl ketone, methyl isobutyl ketone, isopropyl alcohol, methyl cellosolve, and ethyl cellosolve (these are 0 to 50% by weight in the desensitized ink,
Preferably, it is contained in an amount of 0 to 30% by weight. ), Paraffin wax, microcrystalline wax, carnauba wax and the like (these are 0 to 2 in the desensitizing ink).
0% by weight, preferably 0 to 10% by weight. ), Starch, set-off inhibitors such as dextrin (these are
0 to 10% by weight, preferably 0 to 5% by weight is contained in the desensitizing ink. ) Can be used as a material for the desensitizing ink.

The desensitizing ink of the present invention can be easily prepared by those skilled in the art by mixing, dissolving or, if necessary, using a three-roller mill, a sand mill, or the like, and kneading the components. Can be. The desensitizing ink is supplied to the developer sheet by a method such as using a printing machine, spraying with a spray or the like, or writing by hand with a pen or eraser.

The coating amount of the desensitizing ink is 0.5 to 10 g /
m ² , preferably 0.5 to 5 g / m ² . here,
If the amount is less than 0.5 g / m ² , the effect cannot be sufficiently exhibited, and if it exceeds 10 g / m ² , drying becomes difficult during printing.

[0018]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.
In addition, the part in an example shows a weight part.

Preparation of desensitizing ink: To 40 parts of a propylene oxide adduct of ethylenediamine (average molecular weight: 4100), 17 parts of a rosin-modified phenol resin (Tamanol T135, manufactured by Arakawa Chemical Industries, Ltd.) were added and dissolved at 150 ° C. After cooling the melt to 25 ° C., titanium dioxide 2
5 parts and 18 parts of white spindle oil were added. Further, as shown in Table 1, powder of a fluororesin and the like were added, and the mixture was kneaded with a three roller mill to obtain a desensitizing ink. As a test paper,
Commercially available paper under pressure-sensitive copying paper (M-6, N-6
0) was used.

Each desensitizing ink is 3 g / m by offset printing.
Printing was applied so as to be ² . First, the evaluation was performed on the obtained printing surface and paper on pressure-sensitive copying paper (commercially available from Mitsubishi Paper Mills,
N-40, for black coloring), and the entire surface was colored with a super calender to evaluate the desensitizing effect. The obtained printed coated paper was conveyed with an optical character mark reader (OCR-V3050, manufactured by Toshiba Corporation), and the suitability for paper passing was observed.

In the evaluation judgment, ◎: particularly excellent, ：: excellent, Δ: inferior, ×: poor.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

As is clear from the results in Table 2, the desensitizing inks of the present invention are all excellent in the desensitizing effect and the suitability for paper passing.

Claims (3)

(57) [Claims] 1. A desensitizing ink for pressure-sensitive copying paper, comprising a desensitizing agent for reducing or eliminating the function of a color developer for forming a colorless color former and a fluororesin. 2. The desensitizing ink for pressure-sensitive copying paper according to claim 1, wherein the desensitizing agent is a compound obtained by adding an alkylene oxide having 3 or more carbon atoms to ammonia or an amine compound. 3. The desensitizing ink for pressure-sensitive copying paper according to claim 1, wherein the fluororesin is an ethylene tetrafluoride resin.