JPH05295309A - Desensitizing ink for pressure-sensitive copying paper - Google Patents

Abstract

PURPOSE:To provide the objective ink excellent in the desensitizing effect and adaptability to feeding of the paper printed therewith. CONSTITUTION:This ink contains a desensitizing agent and at least one compound selected from among dimethylpolysiloxane and its derivatives. As the desensitizing agent, an adduct of ammonia or an amine compound with a 3C or higher alkylene oxide is preferably used in particular. This invention can give the ink having good desensitizing effect and adaptability to feeding of the paper printed therewith.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a desensitizing ink for pressure-sensitive copying paper. Further, the present invention relates to a desensitizing ink for pressure-sensitive copying paper, which reduces or eliminates the function of a color developing agent that develops 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,
It has long been known that a colored image can be obtained by a contact reaction with a color developer). Specific examples of utilizing this phenomenon include, for example, pressure-sensitive copying paper (US Pat.
No. 505470, No. 2505489, etc.) and thermal recording paper (Japanese Patent Publication No. 45-14039, etc.).

Generally, as a developer for pressure-sensitive copying paper, an inorganic solid acid such as activated clay, acid clay, attapulgite, zeolite, bentonite, silica, aluminum silicate, etc.,
Novolak type phenolic resins and salicylic acid derivatives, or polyvalent metal salts of salicylic acid derivatives are used. Particularly, polyvalent metal salts of salicylic acid derivatives have good coloring properties,
Widely used in the market. Further, recently, many salicylic acid resins or their polyvalent resins have been developed for the purpose of improving the conventional phenolic resin-based color developer, which has a slow color development speed, and the salicylic acid-based color developer, which has slightly poor water resistance of the colored characters. Metal salts have been proposed as developers. Examples of these 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, and 6
3-159082, 63-160877, etc.), 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), aromatic A polyvalent metal salt of a resin obtained by reacting a salicylic acid derivative having a group substituent with a benzyl halide (JP-A-63-254124), and other resin polyvalent metals described in JP-A-63-289017. Organic developers such as salts are known. Further, a polyvalent metal salt compound composed of salicylic acids, rosins, and a polyvalent metal compound has also been disclosed as an organic developer (JP-A-2-563).

In general, as a pressure-sensitive copying paper, an upper paper having a color former layer containing microcapsules containing a color former on a support, a lower paper having a developer layer containing a color developer on a support. Paper, if necessary, a separate type that uses a combination of medium paper with a developer layer and a color developer layer provided on the front and back sides of the support, and a developer or color developer in the form of one or multiple layers of the support. The self type provided on the same surface is used.

Characters colored by the reaction between the color former and the color developer are recorded. However, depending on the format of the slip, it may not be possible to read the characters as the color-developed characters. In the market, it is made into ink and printed on the surface of the layer containing the developer.

In the desensitizing ink, a desensitizing agent is mixed with an ink resin which functions 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, and the like. However, desensitizing inks for letterpress, offset, flexo, etc. are commercially available depending on the form of the ink or the means of printing. UV-curing desensitizing inks are also commercially available to increase the drying speed.

Regarding these desensitizing inks, US Pat. No. 2,777,805, JP-B-44-27255, JP-B-45-21448, and JP-A-46-22651.
No. 46, 29546 and No. 47-3820.
1, gazette 48-4050 gazette, gazette 49-4484.
No. 49, 19647 and No. 49-2300.
8 gazette, the same 49-23850 gazette, the same 58-381.
19, JP-A-47-32915, 48-
6805, 49-43708, 49-
72009, 49-77709, 49.
No. 77770, No. 49-15513, No. 4
No. 9-83509, No. 63-74681, No. 63-41184, No. 63-94879,
No. 63-139781, Japanese Patent Application Laid-Open No. 2-20477, German Patent Application (OLS) 2343800, No. 23590759, No. 2361856, and the like.

In recent years, the usage of passing a printed pressure-sensitive copying paper through a machine so that the machine reads a character or a mark is increasing. Typical reading devices include optical reading devices such as OCR, OMR, and label bar codes.

Desensitizers generally used in desensitizing inks are
A relatively viscous fluid material is used at room temperature so that it does not penetrate through the paper layer after printing or transfer to a portion that needs color development, and that the effect of preventing color development becomes large. Therefore, the surface printed with desensitizing ink is generally relatively sticky. Therefore, when the pressure-sensitive copy paper on which the desensitized printing is performed is passed through a machine such as a reading device, the 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 is excellent in printability and desensitizing effect without deteriorating mechanical passability of pressure-sensitive copying paper.

[0011]

Means for Solving the Problems The present inventor has conducted extensive studies to solve the above problems, and as a result, desensitization containing a desensitizing agent and one or more compounds selected from dimethylpolysiloxane or a derivative thereof. The inventors have found that the above objects can be achieved by using an ink, and completed the present invention.

The dimethylpolysiloxane used in the present invention is represented by the following chemical formula 1, wherein R in the formula is a methyl group is a dimethylpolysiloxane, and the dimethylpolysiloxane derivative is a dimethylpolysiloxane. Some of the methyl groups have been changed to phenyl groups, some have been changed to hydrogen, some have been changed to alkyl groups having 2 or more carbon atoms, epoxy groups,
The thing etc. which changed to the alkyl group which has a substituent, such as a carboxyl group, an amino group, and a hydroxyl group, are mentioned.

[Chemical 1]

The amount of dimethylpolysiloxane or its derivative used is 0.1 to 30% by weight in the desensitizing ink.
And more preferably 0.5 to 10% by weight. 0.5
If it is less than 10% by weight, it is difficult to obtain the desired suitability for mechanical paper passage, and if it exceeds 10% by weight, it is difficult to print other colored ink on the desensitized print, pencil, ballpoint pen, felt-tip pen. And the like, or the balance with dampening water on the printing machine is lost and the printability is deteriorated.

Examples of the desensitizer referred to here include, for example,
The following specific examples can be given. Quaternary ammonium salts such as dodecyltrimethylammonium chloride and octadecylammonium chloride; amines having a large molecular weight such as dodecylamine; 2,4,4-trimethyl-
Substituted oxazoline such as 2-oxazoline; Reaction product of alkylene oxide with diamine or polyamine derivative having a cyclic structure in the molecule such as xylylenediamine and N-aminopropylpiperidine; polyoxyethylene alkylamine, polyoxyethylene alkyl ether, Of polyoxyethylene alkyl phenyl ether, polyethylene glycol, polypropylene glycol, polyoxypropylene alkyl amine, glutamic acid-γ-alkyl ester residue-containing polymer, spiro acetal diamine, N- (aminoalkyl) -lactams, amines There are glycidyl ether adducts and the like. Above all,
As the desensitizer of the present invention, a compound obtained by adding an alkylene oxide having 3 or more carbon atoms to ammonia or an amine compound is particularly effective.

The desensitizing ink according to the present invention contains a desensitizing agent and one or more compounds selected from dimethylpolysiloxane or a derivative thereof, and may optionally contain various other components. . Examples of other components contained in the desensitizing ink of the present invention include materials for general printing ink. For example, natural or synthetic polymer compounds such as ketone resin, polyamide resin, maleic acid resin, phenol resin, epoxy resin, alkyd resin, melamine resin, urea resin, nitrocellulose, ethyl cellulose, butyral resin, polyvinyl alcohol, gelatin, shellac. (These are contained in the desensitizing ink in an amount of 0 to 50% by weight, preferably 5 to 30% by weight.), Barium sulfate,
Talc, kaolin, titanium dioxide, magnesium carbonate,
Inorganic substances such as calcium carbonate, aluminum hydroxide, magnesium hydroxide, calcium oxide, barium hydroxide, beryllium oxide, bentonite, and organic bentonite (these are contained in the desensitizing ink in an amount of 0 to 60% by weight, preferably 0.1% by weight).
1 to 50% by weight is contained. ), Linseed oil, tung oil, soybean oil, cottonseed oil and the like (these are 0 to 0 in the desensitizing ink).
50% by weight, preferably 0 to 30% by weight. ),
Methanol, ethanol, ethyl acetate, toluene, hexane, methyl ethyl ketone, methyl isobutyl ketone,
Organic solvents such as isopropyl alcohol, methyl cellosolve, ethyl cellosolve, etc.
50% by weight, preferably 0 to 30% by weight. ),
Waxes such as paraffin wax, microcrystalline wax, and carnauba wax (these are contained in desensitizing ink in an amount of 0 to 20% by weight, preferably 0 to 10% by weight), anti-set agents such as starch and dextrin. (These are contained in the desensitizing ink in an amount of 0 to 10% by weight, preferably 0 to 5% by weight.) And the like can be used as a material for the desensitizing ink.

The desensitizing ink of the present invention can be easily prepared by a person skilled in the art by mixing, dissolving, or if necessary, using a three-roller mill, a sand mill, etc., by kneading the components. You can The desensitizing ink is supplied to the developer sheet by using a printing machine, spraying with a spray or the like, or handwriting with a pen or an 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 it is less than 0.5 g / m ² , the effect cannot be sufficiently exhibited, and conversely, if it exceeds 10 g / m ² , drying becomes difficult during printing.

[0018]

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

Examples 1-6 and Comparative Examples 1-2 Preparation of desensitizing inks: 40 parts of propylene oxide adduct of ethylenediamine (average molecular weight 4100) with rosin-modified phenol resin (Tamanol T135 manufactured by Arakawa Chemical Industry Co., Ltd.) 17 Parts were added and melted at 150 ° C. After cooling this melt to 25 ° C., 25 parts of titanium dioxide and 18 parts of white spindle oil were added, and the additives and the like as shown in Table 1 were added, and the mixture was kneaded with a three-roll mill to prepare Examples 1-5.
The desensitizing inks used in Comparative Examples 1 and 2 were obtained. Similarly,
Polypropylene glycol (average molecular weight 4000) 50
Parts, 20 parts rosin-modified phenolic resin, 1 titanium dioxide
A desensitizing ink used in Example 6 was obtained by adding 5 parts of dimethylpolysiloxane to an ink composed of 8 parts and 12 parts of white spindle oil.

3 g / of each desensitizing ink on an offset printing machine
The pressure-sensitive copy paper lower paper (N-60, manufactured by Mitsubishi Paper Mills Co., Ltd.) was applied by printing so as to be m ² . The evaluation was performed by using the obtained printed surface and pressure-sensitive copy paper (commercially available from Mitsubishi Paper Mills Co., Ltd., N
-40, for black color development), and the entire surface was colored with a supercalender, and the desensitizing effect was examined.
Further, the printed coated paper obtained was carried by an optical character mark reading device (OCR-V3050 manufactured by Toshiba Corp.), and the suitability for paper passing was observed. The results are listed in Table 2.

The evaluation judgment is expressed as ⊚: particularly excellent, ◯: excellent, Δ: inferior, and x: defective.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

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

Claims (2)

[Claims] 1. A sensation comprising a desensitizing agent that reduces or eliminates the function of a color developing agent that develops a colorless compound, and one or more compounds selected from dimethylpolysiloxane or a derivative thereof. Desensitizing ink for pressure copying paper. 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.