JPH0818458B2 - Desensitizing ink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a desensitizing ink used for pressure-sensitive copying paper and having an excellent desensitizing effect. More specifically, the present invention relates to a desensitizing ink for suppressing or preventing the coloring of a dye precursor in a pressure-sensitive copying paper comprising a combination of a colorless or light-colored dye precursor and a color developing agent.

Generally, a pressure-sensitive copying paper is a sheet having a microcapsule layer containing a solution of an electron-donating basic dye called a dye precursor (hereinafter referred to as "CB sheet") and an electrophilic developer coated. It is used in combination with a sheet having a layer (hereinafter referred to as “CF sheet”). Also, paper coated with microcapsules containing a color developer on the front surface and a dye precursor on the back surface (hereinafter referred to as “CFB sheet”)
If it is used between the B and CF sheets, a large number of copies can be made.

In the pressure-sensitive copying paper used in this way, a desensitizing ink is applied to a CF sheet using a printing machine or the like on portions where copying is not necessary, thereby suppressing or preventing the coloring of the dye precursor.

[Conventional technology]

Known desensitizers include quaternary ammonium salts (Japanese Examined Patent Publication No. 33-3921), tertiary amines having two polyethylene oxide groups (Japanese Examined Patent Publication No. 46-29546), and initial condensation products of urea resins. (Japanese Patent Publication No. 46-35697), polyoxyethylene monoalkyl ester (Japanese Patent Publication No. 47-38201), ethylene oxide addition compound of polyalkylene polyamine (Japanese Patent Publication No. 49-23008), propylene oxide addition compound of alkylene diamine ( JP-B-49-23850), polypropylene glycol having an average molecular weight of 400 to 5000 (JP-B-55-55)
1919), polyamine glycidyl ester or glycidyl ether addition compounds (JP-B-51-22416), diazabicycloalkenes or salts thereof (JP-B-54-26926).
No.), spiro acetal type diamine (Japanese Patent Publication No. 55-16188)
No.), active hydrogen polyamine and alkylene oxide addition compound (Japanese Patent Publication No. 53-23724) and others.

These desensitizing agents are prepared and used in printing inks corresponding to printing methods such as letterpress printing, intaglio printing, lithographic printing, and stencil printing, that is, desensitizing inks.

[Problems to be solved by the invention]

In recent years, research on color developers has progressed, and CF and CFB sheets using a polyvalent metal salt of a salicylic acid derivative and / or a polyvalent metal salt of a salicylic acid co-condensation resin as a color developer have improved coloring ability and stability of a color image. Improved and partially put into practical use.

For example, JP-B-51-25174, JP-B-52-1327, and JP-A-54-54
40898, JP-A-61-100493, Japanese Patent Application No. 61-18027, and the like, polyvalent metal salts of salicylic acid having various substituents, polyvalent metal salts of salicylic acid-based condensates, etc. are typical. Is.

CF sheets and CFB sheets that use these salicylic acid-based polyvalent metal salts as developers have a large developing ability, so when using desensitizing inks that were previously used for phenol resin-based developers, etc. The desensitizing effect on the dye precursor is insufficient, and a sufficient effect cannot be obtained unless the volume of ink is increased.

However, when the amount of the ink is increased, the drying speed becomes slow, and there is a problem during printing such as set-off due to insufficient drying or bleeding to a portion where the ink is not printed.

Some of the adducts of alkylamines and ethylene oxide or propylene oxide, which have been proposed in some cases, have excellent desensitizing effects, but generally have high affinity for water, which poses a problem especially for offset printing inks. Had left.

[Means for solving problems]

The present inventors have conducted various studies to solve such a problem, (In the formula, R is a lower alkylene group, X _{1 to} X ₅ are OH groups or —NR′R ″ groups (R ′ is a hydrogen atom or
C ₁ -C ₁₅ alkyl group, R ″ represents a C ₁ -C ₁₅ alkyl group), and at least one of them is not an OH group). The present invention has been completed by finding that the above problems can be solved by using it as a component.

The compound used in the present invention has a basic skeleton represented by the general formula (I) and generally has the general formula (II) (In the formula, R represents a lower alkylene group.) A dialkyleneamine pentaacetic acid and various alkylamines or dialkylamines are dehydrated (for example, PCl ₃ , PCl ₅ , SOCl ₂
Etc.) in the presence of the condensation reaction.

The alkylamine or dialkylamine used here is represented by the general formula (III) R′-NH—R ″ (III) (wherein R ′ is a hydrogen atom or a C ₁ -C ₁₅ alkyl group, and R ″ is C ₁ -C _{15 represents} an alkyl group.).

Examples of specific compounds include However, the composition is not limited to these, and naturally includes a composition obtained by reacting a mixed amine with dialkylenetriaminepentaacetic acid.

The compound represented by the general formula (I) or a mixture thereof used as a desensitizer in the present invention is generally obtained as a light-colored viscous liquid substance, and has a very high affinity (solubility) for water. There are few. Further, it has a high affinity with the vehicle resin used for preparing the affinity ink.

The desensitizing ink of the present invention contains the compound represented by formula (I) in the desensitizing ink in an amount of 5 to 60% by weight, preferably 15 to 50% by weight.

Examples of materials other than the desensitizer for obtaining the desensitized ink of the present invention include (i) vehicles such as ink resins such as rosin-modified phenol, rosin ester, maleic acid resin, and styrene-maleic acid resin. 0-40 in sensitive ink
% By weight, preferably 5 to 30% by weight.

Examples of the pigment (ii) include inorganic pigments such as titanium dioxide, zinc oxide, calcium carbonate and clays, which are contained in the desensitizing ink in an amount of 0 to 50% by weight, preferably 0.3 to 20% by weight.

(Iii) Vegetable oils such as linseed oil, tung oil, soybean oil, cottonseed oil and the like can be mentioned, and 0 to 50% by weight, preferably 0 in the desensitizing ink.
~ 20% by weight.

(Iv) In addition, in order to improve the printability, additives such as paraffin and metal soap, an anti-UV agent, an antioxidant, a lubricant, a fluorescent enhancer and the like can be mentioned.

Various known methods can be used to obtain the desensitizing ink of the present invention.

The desensitizing ink of the present invention may be used in combination with a known desensitizing agent, if necessary.

(Functions and Effects) The desensitizing ink containing the compound represented by the general formula (I) as an active ingredient may have ink properties capable of being printed by not only letterpress printing but also various printing machines such as flexure, gravure, and offset printing. It is possible and particularly suitable for wet offset printing which is generally used for printing desensitizing ink.

The desensitizing effect of the desensitizing ink of the present invention has a sufficient effect on a CF sheet and a CFB sheet using a polyvalent metal salt of a salicylic acid derivative and / or a polyvalent metal salt of a salicylic acid cocondensation resin as a developer. . It is considered that this desensitizing effect is due to the formation of a complex with a metal that is considered to be the coloring site of the color developer to inactivate the color developer.

Therefore, an excellent desensitizing effect is exhibited with a small amount of the salicylic acid metal salt-based color developer, and yellowing (coloring) of the desensitized portion with time is extremely small.

It goes without saying that the desensitizer of the present invention is also effective against known developers such as clays (eg, acid clay, activated clay, attapulgite, etc.) and phenol resins.

Further, regarding the dye precursor, 3-diethylamino-6
It is extremely effective for various known dye precursors such as triphenylmethanephthalide dye precursors including fluoran dye precursors such as -methyl-7-anilinofluorane.

Since the desensitizer used in the ink of the present invention has extremely low solubility in water, when the ink of the present invention is used and wet offset printing is performed, there is no bleeding in the non-printed portion of the printed portion and a small amount. Since the amount of coating has a desensitizing effect, it is possible to cope with high speed printing.

The CF sheet and CFB sheet coated with the desensitizing ink of the present invention can obtain a good printed surface without yellowing over time and odor.

Desensitizing ink of the present invention is a color developer coating surface weight servings to (CF surface) 1 g / cm ² or more, preferably to exhibit sufficient desensitizing effect by printing 2 to 10 g / cm ^2.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

CB sheets and CF sheets used in the examples and comparative examples were prepared as follows.

Preparation of CF sheet 100 parts of 10% aqueous solution of ethylene maleic anhydride and water
240 parts were mixed, the pH was adjusted to 4.0 with a 10% NaOH aqueous solution, and 200 parts of alkylnaphthalene in which 5% by weight of 3-diethylamino-6-methyl-7-anilinefluorane was dissolved was emulsified with a homomixer. Methylated methylol melamine aqueous solution with a solid content of 50% (Mitsui Toatsu Chemicals “Euramine T-
530 ") was added, and the mixture was kept under stirring at 55 ° C for 3 hours to obtain a microcapsule liquid having an average particle diameter of 5.0μ.

100 parts of this microcapsule solution and 20 parts of flour starch granules
20 parts of 20% oxidized starch and 116 parts of water were added and stirred, and coated on 40 g / m ² paper so that the solid content was 5 g / m ² to obtain a CB sheet.

Preparation of CF Sheet (A) The zinc salt of 3,5-di-α-methylbenzylsalicylic acid was wet-milled using a sand grinding mill in the presence of a small amount of a high molecular weight anionic surfactant, and solidified. An aqueous suspension with a mold weight of 40% by weight was prepared.

Using the aqueous suspension, an aqueous paint having the following composition (solid
30%), and the dry coating amount of 40 g / m ² of high-quality paper is 5.5 g / m
A CF-sheet (A) was prepared by coating and drying so as to be ² .

Composition of water-based paint Solid part by weight Soft calcium carbonate 100 Developer 20 Adhesive Oxidized starch 8 Synthetic latex 8 Preparation of CF sheet (B) 3,5-di-α-methylbenzyl salicylic acid Instead of salicylic acid-α, α ′ Dimethoxy-p-xylene-
A CF sheet (B) was similarly prepared using a zinc salt of a mesitylene co-condensation resin.

Example-1 As a desensitizer, 25 parts of rosin-modified phenol and 10 parts of linseed oil were added to 50 parts of the above compound-1 and dissolved by heating to give a varnish. Twenty-five parts of titanium dioxide was added to this varnish and uniformly kneaded with a three-roll mill to obtain a desensitizing ink.

CF sheet (A) and CF sheet (B) of pressure-sensitive copy paper using the obtained desensitizing ink using a wet offset printing machine
It was printed so that the coating amount was 3 g / m ² .

The wet offset printing suitability was investigated by evaluating the printability, the stain on the dampening water device of the printing machine during wet offset printing, and the stain on the non-printed portion of the printed CF sheet.

Evaluation method ○ Good print finish.

 △ Although printing is possible, it is difficult to put it into commercial use.

 × Cannot be printed.

Black color CF of the obtained desensitized printing paper and pressure-sensitive copying paper
The sheet was used for printing with a typewriter (IBM65). The desensitizing effect was evaluated by a color development test. The Y value of a spectrocolor meter SZ-Σ80 (manufactured by Nippon Denshoku Industries Co., Ltd.) was used for the concentration measurement. The desensitizing effect is expressed by the following equation.

The yellowing was evaluated by placing the desensitized printing paper in an atmosphere of 300 ppm NO _X gas for 30 minutes, measuring the degree of yellowing with a spectrocolor meter SZ-Σ80, and using the w value.

Examples-2 to 5 Desensitizing inks were obtained by using compounds 2 to 5 in the same manner.

Example-6 A desensitized ink was obtained using a condensation reaction product of diethylenetriamine and dialkylamine (CHIRESTO CHEMICAL, CHIREST MZ-4).

Comparative Example 1 Polypropylene glycol (molecular weight 300
0) 25 parts of rosin-modified phenolic resin was added to 50 parts, heated and dissolved to form a varnish. Titanium dioxide on this varnish
25 parts were added, and the mixture was uniformly kneaded with a three-roll mill to obtain a desensitized ink.

Comparative Example 2 25 parts of a rosin-modified phenolic resin was added to polyoxyethylene octadecylamine (n = 10) as a desensitizer, heated and dissolved to give a varnish. Titanium dioxide on this varnish
25 parts were added, and the mixture was uniformly kneaded with a three-roll mill to obtain a desensitized ink.

Using the desensitizing inks obtained in Examples 1 to 6 and Comparative Examples 1 and 2, a desensitized printing paper was prepared in the same manner as in Example 1, and the same desensitized printing paper was tested in the same manner as in Example 1. .

For reference, the test was also performed without using the desensitizing ink. The test results are shown in Table-1.

[Effects of the Invention] The I value showing the desensitizing effect (the smaller the number, the greater the desensitizing effect) is 1.3 to 2.3 in the Examples, and the value is small, indicating that the desensitizing effect is complete. Show (I value 1.3 ~
The value of 2.1 is the effect of the impression of the typewriter on the reflectance. ).

The yellowing I _WB value (the smaller the number, the lesser the yellowing) is in all Examples 1 to 6 and the smaller the yellowing is.

 The wet offset printing suitability is also good.

From the above results, the desensitizing ink of the present invention is clearly superior to the comparative example in desensitizing effect, yellowing, and printability.

Claims (2)

[Claims] 1. A general formula (I) (In the formula, R is a lower alkylene group, X _{1 to} X ₅ are OH groups or —NR′R ″ groups (R ′ is a hydrogen atom or
C ₁ -C ₁₅ alkyl group, R ″ represents a C ₁ -C ₁₅ alkyl group), and at least one of them is not an OH group). Characteristic desensitizing ink for pressure-sensitive copying paper. 2. The reduction according to claim 1, which has a desensitizing effect on a color developing layer using a polyvalent metal salt of a salicylic acid derivative and / or a polyvalent metal salt of a salicylic acid co-condensation resin as a developer. Sensitive ink.