JPH0284470A - Desensitizing ink for pressure-sensitive copying paper - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a desensitizing ink for pressure-sensitive copying paper, in particular, a desensitizing ink for pressure-sensitive copying paper, which is free from edge recovery due to water, has excellent suitability for various types of printing, and has improved desensitizing effects and set-off properties. This invention relates to desensitizing ink for pressure copying paper.

(Prior art) Electron-donating or proton-accepting colorless organic compounds (
It has been known for a long time that a colored image is obtained by the reaction between a color former (hereinafter referred to as a color former) and an electron-accepting or proton-releasing agent (hereinafter referred to as a color developer).

Pressure-sensitive copying paper (
For example, US Patent Nos. 2505470, 2505489, 2550471, 2548366, 271
No. 2507, No. 2730456, No. 2730457, No. 3418250, No. 3672935), thermal recording paper (for example, Japanese Patent Publication No. 43-4160, No. 43-760)
No. 0, No. 45-14039, U.S. Patent No. 2939009
No.), etc. are failed. Furthermore, a printing method is known in which a colored image is obtained by supplying ink containing a color former to a sheet coated with a color developer (German patent application (OLS) 1939962).
issue).

The color developer has the properties defined above and includes clays, phenolic resins, metal salts of aromatic carboxylic acids, and the like.

Generally, in pressure-sensitive copying paper, a combination of a layer containing microcapsules containing a coloring agent and a color developer layer is used to obtain a colored image, and these layers are brought into contact with each other to obtain a colored image. This is done by destroying the microcapsules and bringing the color forming agent and color developer into contact.

Generally, these color developers are used as a color developer sheet that is uniformly applied to the entire surface of the support, but depending on the purpose of use of the pressure-sensitive copying paper, there may be areas on the side of the color developer sheet that do not require recording. In such cases, a method of desensitizing the color developer sheet by applying a desensitizing ink containing a desensitizing agent to that portion of the color developer sheet using a printing machine or the like is used.

Desensitizing inks used for such purposes are disclosed in, for example, U.S. Pat.
No. 5, No. 45-21448, No. 46-22651,
46-29546, JP 47-32915, JP 47-38201, JP 48-4050, JP 48-6805, JP 49-4484, JP 49-
No. 19647, No. 49-23008@, No. 49-238
No. 50, JP-A-49-43708, JP-A No. 49-7200
No. 9, No. 49-77709, No. 49-77710,
No. 49-15513, No. 49-83509, German patent application (OLS>2343800, No. 235907)
No. 9, No. 2361856, Japanese Patent Publication No. 58-38119, Japanese Patent Publication No. 74681-1981, Japanese Patent Application Publication No. 63-41184
Details are given in the issue.

(Problem to be Solved by the Invention) Desensitizing inks used for the above purpose generally use a desensitizer, a pigment such as titanium dioxide, a binder, and if necessary a diluent such as an organic solvent. No ink has been found that has an excellent desensitizing effect against various color developers and has good set-off properties. Also, if a desensitizer that is highly soluble in water is used, double images due to water will occur, and if a desensitizer that is insoluble in water is used, the printed area will not be uniform when used for offset printing, which are contradictory characteristics. It had become ink.

Therefore, an object of the present invention is to provide a desensitizing ink for pressure-sensitive copying paper that has excellent printability, has an excellent desensitizing effect on various color developers, has good set-off properties, and is free from double images due to water. It's about doing.

(Means for solving problems) The above objects are achieved by the invention described below.

That is, the present invention provides a desensitizing ink containing a desensitizing agent, a pigment, and a binder, in which N-aminopropylcyclohexylamine, 1,4-diaminocyclohexane, xylylenediamine, isophoronediamine,
4 to 70 per mole of an amine compound selected from N-7 minoethylpiperazine, N, N'-bis(aminopropyl)piperazine, N-aminopropylmorpholine, and 1,3-bis(aminomethyl)cyclohexane. The desensitizing ink for pressure-sensitive copying paper is characterized in that it contains an alkylene oxide adduct in which 40 mol % or more of the alkylene oxide is butylene oxide.

At least 40% of the alkylene oxide must be butylene oxide, but the remaining 60% or less can be ethylene oxide, propylene oxide, butylene oxide, styrene oxide, etc., but the most preferred is butylene oxide. be.

These desensitizers do not cause the phenomenon of oral browning of the area to which they are applied, and do not cause any set-off even under severe conditions. It also has particularly excellent hydrophobicity, and exhibits excellent printability not only in letterpress and flexographic printing, but also in offset printing.

Taking advantage of the above features of the present desensitizer, it can be used alone or in combination with conventionally known desensitizers.

As the pigment used in the present invention, white pigments such as titanium dioxide, barium sulfate, calcium carbonate, talc, kaolin, and bentonite are used.

The binders used in the present invention include rosin-modified phenolic resin, ketone resin, polyamide resin, maleic acid resin,
Natural or synthetic polymeric compounds such as phenolic resins, epoxy resins, alkyd resins, melamine resins, urea resins, nitrocellulose, ethylcellulose, butyral resins, polyvinyl alcohol, gelatin, and shellac are used.

The desensitizing ink of the present invention can be used with the above composition alone, but if necessary, an organic solvent may be used as a diluent. Examples of the organic solvent include linseed oil, tung oil, soybean oil, cottonseed oil, methanol, ethanol, ethyl acetate, toluene, hexane, methyl ethyl ketone, methyl isobutyl ketone, polypropylene glycol, polybutylene glycol, and paraffin oil.

The desensitizing ink of the present invention may also contain waxes such as paraffin wax, microcrystalline wax, and carbanal wax, starch, anti-set-off agents such as dextrin, ultraviolet absorbers, antioxidants, etc., as necessary. .

(Example) To 40 parts by weight of the desensitizer shown in Table 1, 17 parts by weight of a rosin-modified phenol resin (Tamanol T135, manufactured by Maeyo Kagaku Co., Ltd.) was added and dissolved at 150°C. 25% of this lysate
After cooling to .degree. C., 25 parts by weight of titanium dioxide and 18 parts by weight of white spindle oil were added and kneaded in a three-roller mill to obtain desensitized inks for offset and letterpress.

As the test paper, a commercially available pressure-sensitive copy paper (Fuji Pressure-Sensitive Paper, manufactured by Fuji Photo Film ■) was used.

Each desensitizer composition was applied by printing at a rate of 3 q/rd in both letterpress and offset printing. In the evaluation, first, the suitability for offset printing was observed during printing, and then a load of 1007/d was applied to the obtained printing coated paper.
- After combining the color developer layer on the lower paper, the transfer to the lower paper is evaluated as set-off, and the printed surface and the upper paper (commercially available Fuji pressure-sensitive paper) are overlapped and the surface is heated in a super calendar. Color development was performed, and the "desensitizing effect" and uniformity of the desensitizing effect were evaluated [raw]. Hereinafter, the present invention will be specifically explained with reference to Examples. In Examples, oxybutylene group and oxypropylene group are each abbreviated as BOLPO.

(Comparative Example) The desensitizers shown in Table 1 were made into ink and evaluated in the same manner as in the Examples.

Table 1 (Margins below) ◎: Especially excellent O: Excellent △: Slightly inferior ×: Inferior (Margins below) (Effects of the invention) The desensitizing ink according to the present invention has good printability and setability. Excellent in off-resistance and desensitization effect.

Claims (1)

[Claims] N-aminopropylcyclohexylamine, 1,4-diaminocyclohexane, xylylenediamine, isophoronediamine, N-aminoethylpiperazine, N,N'
- per mole of an amino compound selected from bis(aminopropyl)piperazine, N-aminopropylmorpholine, and 1,3-bis(aminomethyl)cyclohexane,
4 to 70 moles of alkylene oxide adduct,
A desensitizing ink for pressure-sensitive copying paper, characterized in that 40 mol% or more of the alkylene oxide contains an adduct of butylene oxide.