JPH08290658A - Desensitizing ink for developer sheet and the developer sheet - Google Patents

Abstract

PURPOSE: To easily detect a printed area by visual observation by a desensitizing ink for a developer sheet consisting of a desensitizer, a pigment, and a binder, wherein the desensitizing ink contains an acid-base indicator or a mixture of an electron donative coupler and an acid material. CONSTITUTION: In a developer sheet, a developer layer 12 is provided on a support body 11 and a desensitizing ink layer 13 is formed thereon. The desensitizing ink layer 13 contains an acid-base indicator or a mixture of an electron donative coupler and an acid compound. A desensitizing ink preferably has a characteristic that not only it colors when it is applied on the support body 11 and dried, but also a colored color phase gradually vanishes. Accordingly, in manufacturing the developer sheet, after the desensitizing ink is applied to a desired area of a developer layer 12 by printing and dried, the formed area can be ascertained by visual observation immediately. The acid-base indicator or the electron donative coupler of 0.05-5 pts.wt. is added based on 100 pts.wt. of desensitizer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a desensitizing ink for a developer sheet and a developer sheet having a desensitizing ink layer, and particularly to a desensitizing ink capable of forming a desensitizing ink layer which can be visually detected. And a developer sheet on which the desensitizing ink layer is formed.

[0002]

2. Description of the Related Art An electron-donating colorless organic compound (hereinafter referred to as
It has been known for a long time that a color is exhibited by a reaction between a "color-forming agent" and an electron-accepting substance (hereinafter also referred to as "developing agent"). A pressure-sensitive recording sheet is known as a specific application of this phenomenon. In the pressure-sensitive recording sheet, a color former layer composed of microcapsules containing a color former and a color developer layer containing a color developer are brought into contact with each other, and pressure is applied thereto according to the writing pressure, type, etc. to form the microcapsules. The color image is formed by destroying and reacting the color developing agent with the color developing agent.

Pressure-sensitive recording sheets are often used in the form of forms as carbonless recording sheets. Generally, a carbonless type recording sheet is composed of two types of sheets, an upper paper having a color former layer formed on one side of a support (generally paper) and a lower paper having a color developer layer formed on one side of the support. A combination of three types of sheets, that is, a combination of the above-mentioned upper paper, a color developer layer formed on one surface of the support, and a developer layer formed on the opposite surface thereof, and a lower paper described above. Used as a configuration. The lower and middle sheets are
It is called a developer sheet because it has a developer layer on one surface.

Clays, phenolic resins, metal salts of aromatic carboxylic acids and the like are known as color developers having the above-mentioned properties. In general, a coating liquid containing these color developers is uniformly applied to the entire surface of a paper (support) to form a color developer layer, thereby producing a color developer sheet. The color developer layer of the color developer sheet (middle paper or lower paper) thus obtained is for forming a color image, but when it is desired to provide an area where a color image cannot be formed depending on the application. There is. Such a region can be formed by applying a desensitizing ink containing a desensitizing agent only to the region by printing or the like.

As described above, when the desensitizing ink is applied only on a specific area of the developer layer, it is determined whether the desensitizing ink is formed in a predetermined area (position) on the developer layer. After the confirmation, the desensitizing ink is formed under the confirmed coating conditions, and the actual manufacturing is performed. However, since the developer layer is white and the applied desensitizing ink layer is almost white, the desensitizing ink application position cannot be immediately confirmed. After the application by the machine, the printing machine is stopped once, and the applied material (developing agent sheet) is sampled for confirmation.
As a method for confirming the coating position, Japanese Patent Laid-Open No. 50-62
There is known a method of spraying a solution in which a color former described in JP-A 492 is dissolved in a solvent onto the surface of the developer layer. As such a color developing agent solution, for example, "Spray Checker" manufactured by Fuji Photo Film Co., Ltd. is commercially available. That is, when the color developer solution is sprayed on the surface of the developer layer, the area where the desensitizing ink does not exist develops color, and the area where the desensitizing ink exists (that is, the surface of the developer layer) does not develop color. The coated area can be confirmed.

However, in the work of spray-coating the above-mentioned color-forming agent solution, it is necessary to perform sufficient ventilation so that the organic solvent does not fill the inside of the work place, or it is necessary to perform it in another well-ventilated place. In addition, the sampling as described above also causes an unusable portion of the developer sheet. Furthermore, desensitizing ink is usually printed continuously by offset printing, so it is desirable to continuously confirm the desensitizing ink formation area, but it is necessary to print the desensitizing ink formation area by spray coating. However, it is extremely difficult to carry out continuously. Furthermore, such a confirmation method has a problem that not only the developer sheet but also its peripheral devices may be contaminated.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to form a desensitizing ink layer whose position can be easily visually detected when printed on the developer layer of a developer sheet. Another object of the present invention is to provide a desensitizing ink for a color developer sheet, which enables Another object of the present invention is to provide a developer sheet having a desensitizing ink layer that can easily detect the area of the desensitizing ink layer during coating and drying.

[0008]

The present invention provides a desensitizing ink for a developer sheet, which comprises a desensitizing agent, a pigment and a binder, wherein the desensitizing ink comprises an acid / base indicator or an electron-donating coloring agent and an acid. A desensitizing ink for a developer sheet, characterized in that it contains a mixture with a substance.

The preferred embodiments of the above desensitizing ink for color developer sheet of the present invention are as follows. 1) The desensitizing ink as described above, wherein the acid / base indicator or the electron-donating color former is contained in an amount of 0.05 to 5 parts by weight based on 100 parts by weight of the desensitizing agent. 2) The desensitizing ink as described above, wherein the acid / base indicator is neutral or alkaline and exhibits color. 3) The desensitizing ink as described above, wherein the acidic substance is a volatile compound. 4) The desensitizing ink as described above, wherein the acidic substance is a phenol derivative.

The present invention also has a developer having, on one surface of a support, a developer layer containing an electron-accepting developer capable of forming a color image by contact with an electron-donating color former. There is also a developer sheet characterized in that a desensitizing ink layer formed from the desensitizing ink for a developer sheet is provided in a part of the surface of the developer layer in the sheet.

The preferred embodiments of the color developer sheet of the present invention are as follows. 1) The above-described developer sheet, in which the desensitizing ink layer is applied and formed by offset printing. 2) The color developer sheet is an intermediate paper in which a color developer layer containing microcapsules containing a color developer is provided on the surface on the side where the developer layer is not provided.

The desensitizing ink for a color developer sheet of the present invention is characterized by containing a mixture of an acid / base indicator or an electron donating color former and an acidic substance. Such a desensitizing ink for a color developer sheet is characterized in that when it is applied to a support (usually paper) and dried, it develops color, and then the developed hue gradually disappears. Therefore, when a developer sheet having a desensitizing ink layer is produced, by using the desensitizing ink, color is developed at the time of coating and drying.
The formation area of the desensitized ink layer formed by the color development can be immediately confirmed. Furthermore, the developed color disappears naturally without any special treatment. Therefore, the present invention
While having the advantage that the area where the desensitizing ink layer is formed can be confirmed immediately, the produced developer sheet is no different from a normal developer sheet.

The developer sheet provided with the desensitizing ink layer of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram schematically showing a cross section of a typical example of the color developer sheet of the present invention. In FIG. 1, a color developer layer 12 is provided on a support 11, and a desensitizing ink layer 13 is formed in a specific region on the color developer layer 12. This laminate is usually used as a lower sheet. When a color-forming agent layer composed of color-forming agent-containing microcapsules is provided on the surface on which the color-developing agent layer 12 is not provided, it is used as an inner sheet.

In the present invention, the desensitizing ink layer 13 comprises
As described above, a mixture of an acid / base indicator or an electron-donating color former and an acidic compound (these solutions are applied to paper,
It has a property that it develops a color when dried and the hue thereof gradually disappears). Such desensitizing ink not only develops a color when the desensitizing ink is applied to a support and dried, but the hue of the developed color gradually increases (generally, 1
It disappears within 7 days). Therefore, when the developer sheet is manufactured, it is possible to immediately visually confirm the formation area of the developer layer after the desensitizing ink is applied to the desired area of the developer layer by printing or the like and dried. As a result, it is possible to easily detect the printing area of the desensitizing ink, which is conventionally performed by the spray checker, continuously while printing and without contaminating the recording paper or the like.

The desensitizing ink of the present invention can be manufactured as follows. The desensitizing ink of the present invention comprises a desensitizing agent,
A conventional oil-soluble ink composition comprising a pigment and a binder further contains a mixture of an acid / base indicator or an electron-donating color former and an acidic substance.

Acid / base indicators include alizarin red, alizarin yellow, ammonium iron (III) sulfate,
Bromocresol green, bromocresol purple, bromophenol blue, bromothymol blue,
Chlorophenol red, Congo red, o-cresolphthalein, cresol red, 2,5-dinitrophenol, 2,6-dinitrophenol, diphenylamine, iron (III) sulfate, lacmoid, methanyl yellow, methyl orange, methyl red, Methyl yellow,
Neutral red, nitramine, p-nitrophenol, phenolphthalein, phenol red, porier blue, rosolic acid, thymol blue, thymolphthalein, tropeoline O, tropeoline OO, uranine, 2-dimethylsulfamoyl-5-methanesulfonamide- 4- (4-sulfamoylphenylazo) -1
-Naphthol, 5-benzenesulfonamide-4- (2
-Methanesulfonyl-4-nitrophenylazo) -1-
Naphthol, crystal violet and its carbinol body, malachite green and its carbinol body,
(4-dodecylbenzenesulfonyl) -bis (4-diethylaminophenyl) carbinol, and 1- (2-
Carboxyphenyl) -4-diethylamino-5-phenylaminofuran and the like can be mentioned. Among these, Alizarin Yellow, Bromocresol Green,
Bromocresol purple, bromophenol blue,
Bromothymol blue, chlorophenol red, congo red, o-cresolphthalein, cresol red, 2,5-dinitrophenol, methanyl yellow, methyl orange, methyl red, nitramine, p-
Nitrophenol, phenolphthalein and phenol red are preferred.

The above-mentioned acid / base indicator is generally used as a solution dissolved in an organic solvent such as alcohol (eg ethanol). That is, the desensitizing ink of the present invention can be obtained by adding a solution of an acid / base indicator to the desensitizing ink. Examples of the organic solvent include low boiling point alcohols such as methanol, ethanol and propanol; low boiling point hydrocarbons such as pentane and hexane; low boiling point aromatic hydrocarbons such as benzene, toluene and xylene; acetone, cyclohexanone and dioxane. Examples thereof include ethers; alkyl halides such as chloroform and carbon tetrachloride; esters such as methyl acetate and ethyl acetate; cellosolve; and ethylene glycol.

The concentration of the acid / base indicator solution is 1 to 40.
Weight% is preferable, and 2 to 20 weight% is especially preferable. The desensitizing ink preferably contains an acid / base indicator in an amount of 0.05 to 5 parts by weight based on 100 parts by weight of the desensitizing agent.
It is particularly preferable to contain 0.2 to 3 parts by weight.

A so-called leuco dye can be used as the electron-donating color former used in the mixture of the electron-donating color former and the acidic substance. For example, triphenylmethanephthalide compound, fluorane compound, phenothiazine compound, indolylphthalide compound,
Various compounds such as leuco auramine compounds, rhodamine lactam compounds, triphenylmethane compounds, triazene compounds, spiropyran compounds, fluorene compounds can be mentioned. Of these, crystal violet lactone and malachite green lactone are preferable.

As the acidic substance, 4-t-butylphenol, 4-hydroxydiphenoxide, α-naphthol, β-naphthol, methyl-4-hydroxybenzoate, 4-hydroxyacetophenol, 4-t-octylcatechol, 2, 2'-hydroxydiphenol,
2,2'-methylenebis (4-methyl-6-t-isobutylphenol), p-hydroxybenzaldehyde,
4,4'-isopropylidene bis (2-t-butylphenol), 4,4'-sec-butylidene diphenol, 4-phenylphenol, 4,4'-isopropylidenediphenol, 2,2'-methylenebis (4 -Chlorophenol), hydroquinone, 4,4'-cyclohexylidenediphenol, 1-oxy-2-naphthoic acid, 2-oxy-p-toluic acid, salicylic acid, m-oxybenzoic acid, p-oxybenzoic acid, 4 Mention may be made of oxyphthalic acid, gallic acid, benzoic acid, ethyl p-hydroxybenzoate, butyl p-hydroxybenzoate and benzyl p-hydroxybenzoate. Of these, 4-t-butylphenol and p-oxybenzoic acid are preferred.

When a mixture of an electron-donating color former and an acidic substance is used, the electron-donating colorant and an acidic compound may be added directly to the desensitizing ink, but these are volatilized from the acidic substance (compound). It is preferable to add the one dissolved in an easy organic solvent. Thereby, the desensitizing ink of the present invention can be obtained. Examples of the organic solvent include low boiling point alcohols such as methanol, ethanol and propanol;
Low boiling point hydrocarbons such as pentane and hexane; Low boiling point aromatic hydrocarbons such as benzene, toluene and xylene; Ethers such as acetone, cyclohexanone and dioxane; Alkyl halides such as chloroform and carbon tetrachloride; Methyl acetate, ethyl acetate, etc. The esters thereof; cellosolve; and ethylene glycol.

The mixing ratio (weight ratio) of the electron-donating color former and the acidic compound is preferably 1:99 to 50:50, and particularly preferably 5:95 to 40:60. The concentration of the solution of the electron-donating color former is preferably 1 to 40% by weight, particularly 2 to 2%.
0% by weight is preferred. Further, the desensitizing ink preferably contains 0.1 to 5 parts by weight, and particularly preferably 0.2 to 3 parts by weight, of the electron-donating color former based on 100 parts by weight of the desensitizer.

When the desensitizing ink containing the above-mentioned acid / base indicator (usually almost uncolored) is applied to paper which is a support, it develops color upon drying. Normally, the desensitizing ink dries very quickly, so the color develops almost immediately when applied.
The formation area of the desensitizing ink application area can be easily confirmed immediately and visually. The color-desensitized desensitized ink layer gradually loses its color when exposed to air, and generally disappears completely within 7 days (preferably within 1 day).

Further, a desensitizing ink containing a mixture of the electron-donating color former and an acidic substance (usually hardly colored due to the presence of a polar solvent) was applied to a support paper. In this case, the electron-donating color former and the acidic compound react with each other as the material is dried to develop a color. Usually, the desensitizing ink is dried very quickly, so that the color is developed almost at the same time as the application, and the application area of the desensitizing ink can be visually confirmed immediately and easily. The desensitized ink layer that has developed color gradually loses color due to recrystallization of the electron-donating color former or by volatilization or sublimation of the acidic substance,
Generally, the color disappears almost completely within 7 days (preferably within 1 day).

As the desensitizer that can be used in the desensitizing ink of the present invention, known materials can be used. For example, quaternary ammonium salts such as dodecyltrimethylammonium chloride and octadecylammonium chloride; high molecular weight amines such as dodecylamine and dodecyldiamine; substituted oxazolines such as 2,4,4-trimethyl-2-oxazoline; xylenediamine and N.
-Diamines having a cyclic structure in the molecule such as aminopropylpiperidine; reaction products of polyamine derivatives such as ethylene oxide, propylene oxide or butylene oxide adducts of polyamines with alkylene oxides; polyoxyethylene alkylamines; polyoxyethylene alkyl ethers Polyoxyethylene ester; Polyoxyethylene alkyl phenyl ether; Polyethylene glycol; Polypropylene glycol; Polyoxypropylene alkylamine; Polymer having glutamic acid-γ-alkyl ester residue; Spiroacetal diamine; N- (aminoalkyl)- Examples thereof include lactams and glycidyl ether adducts of amines. Reaction products of alkylene oxides with polyamine derivatives such as ethylene oxide, propylene oxide or butylene oxide adducts of polyamines are preferred.

Examples of pigments that can be used in the desensitizing ink of the present invention include white pigments such as titanium dioxide, barium sulfate, calcium carbonate, talc, kaolin and bentonite. The pigment is preferably contained in the ink in an amount of 5 to 200 parts by weight with respect to 100 parts by weight of the desensitizer, and more preferably 10 to 100 parts by weight.

As the binder that can be used in the desensitizing ink of the present invention, rosin-modified phenol resin, ketone resin, polyamide resin, maleic acid resin, phenol resin, epoxy resin, alkyd resin, melamine resin,
Examples thereof include urea resins, nitrocellulose, ethyl cellulose, butyral resins, synthetic resins such as polyvinyl alcohol, and natural resins such as gelatin and shellac. The binder is 5 to 100 parts by weight of the desensitizer.
It is preferably contained in the ink in an amount of 200 parts by weight, more preferably in the range of 10 to 100 parts by weight.

If desired, the desensitizing ink of the present invention may be diluted with an organic solvent before use. Organic solvents include linseed oil, tung oil, soybean oil, cottonseed oil, methanol,
Examples thereof include ethanol, ethyl acetate, toluene, hexane, ethyl acetate, toluene, hexane, methyl ethyl ketone, methyl isobutyl ketone, polypropylene glycol, polybutylene glycol, paraffin oil and the like. Further, if necessary, an ultraviolet absorber, waxes such as paraffin wax, listerin wax, carnauba wax, etc., or anti-setoff agents such as starch and textrin may be used.

In the desensitizing ink of the present invention, for example, the above desensitizing agent (optional ultraviolet absorber) is heated and mixed, and after cooling, an organic solvent is added if desired. The resulting varnish contains a pigment,
A desensitizing ink can be manufactured by adding and dispersing a binder and a mixture of the acid / base indicator of the present invention or the electron-donating color former and an acidic substance. The above-mentioned dispersion can be performed by a roll mill such as a three roll mill, an art writer, a sand grinder or the like.

The final coating amount (solid content) of the desensitizing ink coated on the surface of the developer layer (described later) on the support is 0.
^{8g / m 2 ~4.0g / m 2} , preferably 1.0 g / m
^{2 to} 3.0 g / m ² is suitable.

The developer sheet of the present invention, as described above,
A specific desensitizing ink layer obtained by applying the desensitizing ink to a desired region on the surface of the developer layer is provided. Therefore, except for this specific desensitizing ink layer, it has the same structure as a conventionally known pressure-sensitive recording sheet and can be manufactured in the same manner. The support may be any support conventionally used as a support for a color developer sheet, for example, high-quality paper, medium-quality paper, waste paper, machine-coated paper, art paper, cast coat. Examples thereof include paper, synthetic paper, resin coated paper, plastic film and the like.

The color developing agent contained in the color developing layer for contacting the color developing agent layer of another pressure-sensitive recording sheet of the present invention includes:
Acid clay, activated clay, attapulgite, zeolite,
Examples include bentonite, clay substances such as kaolin, metal salts of aromatic carboxylic acids, phenol formaldehyde resins and the like. Of these, aromatic carboxylic acid metal salts are preferable. Preferred specific examples of the aromatic carboxylic acid metal salt include 3,5-di-t-butylsalicylic acid and 3,5-di-t-butylsalicylic acid.
5-di-t-octylsalicylic acid, 3,5-di-t-nonylsalicylic acid, 3,5-di-t-dodecylsalicylic acid, 3-methyl-5-t-dodecylsalicylic acid, 3-t
-Dodecyl salicylic acid, 5-t-dodecyl salicylic acid,
5-cyclohexylsalicylic acid, 3,5-bis (α, α
-Dimethylbenzyl) salicylic acid, 3-methyl-5-
(Α-Methylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl) -5-methylsalicylic acid, 3- (α,
α-Dimethylbenzyl) -6-methylsalicylic acid, 3-
(Α-Methylbenzyl) -5- (α, α-dimethylbenzyl) salicylic acid, 3- (α, α-dimethylbenzyl)
-6-ethylsalicylic acid, 3-phenyl-5- (α, α
Zinc salt, nickel salt, aluminum salt, calcium salt of dimethylbenzyl) salicylic acid, carboxy-modified terpene phenol resin, salicylic acid resin which is a reaction product of 3,5-bis (α-methylbenzyl) salicylic acid and benzyl chloride Etc. can be mentioned.

The above-mentioned aromatic carboxylic acid metal salt can be mechanically dispersed in an aqueous system or dissolved in an organic solvent before use.

When the aromatic carboxylic acid metal salt is mechanically dispersed, it can be treated with a ball mill, an art writer, a sand grinder or the like to prepare a dispersion liquid.

As the organic solvent for dissolving the metal salt of aromatic carboxylic acid, diisopropylnaphthalene, 1-phenyl-1-xylylethane, 1-phenyl-1-isopropylphenylethane, 1-phenyl-1-ethylphenylethane, toluene, Examples thereof include xylene, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, ethyl acetate, butyl acetate, amyl acetate, methylene chloride, butanol, paraffin and kerosene.

A solution prepared by dissolving an aromatic carboxylic acid metal salt in the above organic solvent is added to the dispersion-containing water in an amount of 5 to 120% by weight, preferably 50 to 100% by weight, and emulsified and dispersed. Subsequently, the emulsified dispersion may be heated to remove the organic solvent. The aromatic carboxylic acid metal salt is generally used by dissolving it in an organic solvent in an amount of 10 to 200% by weight.

As the dispersant, an ionic or nonionic surfactant or a water-soluble polymer compound can be used. Examples of the surfactant include alkylbenzene sulfonate, alkylnaphthalene sulfonate, alkyl sulfonate, dialkyl sulfosuccinate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyhydric alcohol fatty acid partial ester and the like. . Examples of the water-soluble polymer compound include polyvinyl alcohol, modified polyvinyl alcohol, polyacrylamide, sodium polyacrylate, polyvinyl ether, sodium polystyrene sulfonate, and maleic anhydride copolymer.

The coating liquid for forming the developer layer contains, as a binder, styrene / butadiene copolymer latex, vinyl acetate latex, acrylic ester latex, polyvinyl alcohol, polyacrylic acid, maleic anhydride. / Styrene copolymer, carboxymethylcellulose, synthetic polymers such as methylcellulose,
Alternatively, natural polymers such as starch, casein, gum arabic and gelatin may be added.

The final coating amount of the color developer applied to the support is
^{0.1g / m 2 ~3.0g / m 2} , preferably 0.2g
/ M ^{2 to} 1.0 g / m ² is suitable.

The color developer sheet of the present invention has a color developer layer and a desensitizing ink layer thereon on a support.
On the back side thereof, a color-forming agent layer composed of color-forming agent-containing microcapsules may be formed (middle paper). Further, in the pressure-sensitive recording sheet (upper paper or middle paper) used in combination with the color developer sheet of the present invention, a color former layer composed of microcapsules containing a color former is formed. Such a color-developing agent layer can be formed in the same manner as the color-developing agent layer composed of the microcapsules of the conventional pressure-sensitive recording sheet.
For example, a color former is dissolved in a suitable solvent to form microcapsules, and a coating liquid for forming a color former layer containing microcapsules together with a binder, a capsule protector, etc. is prepared, coated on a support, and dried to develop a color. The agent layer is formed.

The color forming agent contained in the color forming agent layer needs to be relatively changed as described above depending on the color forming agent layer used, but a conventional color forming agent can be used. For example, triphenylmethanephthalide compound, fluoran compound, phenothiazine compound, indolylphthalide compound, leukoauramine compound, rhodamine lactam compound, triphenylmethane compound, triazene compound, spiropyran compound, Various compounds such as fluorene compounds can be mentioned.

As the solvent, natural or synthetic oils can be used alone or in combination. Examples of such solvents include vegetable oil, kerosene, paraffin, naphthenic oil,
Examples thereof include alkylated biphenyl, alkylated terphenyl, chlorinated paraffin, alkylated naphthalene, diarylalkane, and phthalic acid ester.

The microcapsules containing the color former can be produced by any method known per se, for example, interfacial polymerization method, internal polymerization method, phase separation method, external polymerization method, coacervation method and the like. it can. In addition, a water-soluble binder, a latex-based binder or the like can be used as the binder, and cellulose powder, starch particles, talc or the like can be used as the capsule protecting agent. The formation of the microcapsule layer on the support can also be performed by a method known per se.

The final coating amount of the color former in the color former layer is 0.
03-0.30 g / m ² , preferably 0.05-0.2
0 g / m ² is suitable.

Next, a method for detecting the formation area of the desensitizing ink layer formed on the developer layer using the desensitizing ink of the present invention will be described. That is, in the desired area of the developer layer of the developer sheet (the area where a color image is not desired to be formed), the desensitizing ink for developer sheet of the present invention is applied by printing, and after drying, It is carried out by visually detecting the formation area of the desensitized ink layer which is colored by drying. The desensitizing ink for the color developer sheet of the present invention is
Since it contains a mixture of a basic indicator or an electron-donating color former and an acidic substance, when the printed surface is viewed after printing, only the desensitizing ink layer formed on the developer layer develops color (depending on the substance used. Different colors). This makes it possible to easily detect whether or not the desensitized ink layer is formed at a predetermined position. Since the color of the desensitizing ink layer gradually disappears, the developer sheet obtained without requiring special decoloring treatment can be used as a product.
Further, such detection is extremely simple as compared with the method using the conventional spray checker, that is, it can be detected visually, while continuously printing the desensitizing ink on the developer layer by offset printing, The above detection can be performed continuously. At this time, it is possible to detect the printing speed while maintaining the normal speed (generally 20 to 200 m / min). Furthermore, since such a detection method can be performed visually, it is not necessary to sample the recording paper, and thus all printed materials can be made into products.

Further, the desensitizing ink is printed only on a specific area of the developer layer, but it may be partially printed on the developer layer other than the area (background stain). The detection is also important in producing a pressure-sensitive recording sheet having a desensitizing ink layer. In the above method, the background stain portion can be visually detected in the same manner as in the detection of the desensitization ink layer. Therefore, the desensitization ink is continuously printed, and the background stain portion is detected while continuously moving the printing sheet. be able to. Therefore, the above-described detection method can be used even in a production system in which the printed developer sheet is directly wound on a roll after offset printing by the roll. On the other hand, the detection method using the spray checker cannot be used in the winding production system, and the production system includes a step of folding once after printing (that is, a production system that can be taken out to apply the spray checker).
Otherwise it cannot be used.

[0048]

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

[Example 1] [Preparation of developer sheet (lower paper)] 15 parts by weight of zinc 3,5-di-α-methylbenzylsalicylate, 120 parts by weight of calcium carbonate, 30 parts by weight of activated clay, zinc oxide 20 parts by weight and 1 part by weight of sodium hexametaphosphate in 20 parts of water
In addition to 0 parts by weight, a dispersion was prepared by dispersing with a sand grinder so that the average particle diameter was 3 μm.
Next, to 400 parts by weight of this dispersion, polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name “PVA-203”)
10 parts by weight of 10% by weight aqueous solution and 100 parts by weight of 10% by weight aqueous solution of polyvinyl alcohol (Kuraray Co., Ltd., trade name "PVA-117") are added, and water is added so that the solid content concentration becomes 20% by weight. In addition, adjustment was performed to prepare a coating liquid for forming a developer layer.

On one surface of the base paper having a basis weight of 50 g / m ² ,
The developer layer-forming coating liquid was applied using an air knife coater so that the solid coating amount was 5 g / m ² , and the coating film was dried to produce a developer sheet.

[Preparation of Coloring Agent Sheet (Upper Paper)] As a coloring agent, 5.0 parts by weight of 2-anilino-3-methyl-6-diethylaminofluorane, 1.0 part by weight of benzoylleucomethylene blue and 2-dibenzyl were used. 2.0 parts by weight of amino-6-diethylaminofluorane was dissolved in 100 parts by weight of diisopropylnaphthalene. Carbodiimide-modified diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name "Millionate MTL", solid content 100) as polyvalent isocyanate in the obtained oily liquid.
%) 10 parts by weight and an isocyanurate of hexamethylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., trade name "Coronate EH", 75% by weight ethyl acetate solution).
A primary solution was prepared by dissolving 5 parts by weight and 3.0 parts by weight of a butylene oxide adduct of ethylenediamine (addition mole number of butylene oxide to ethylenediamine: 16.8 mol, molecular weight: 1267) as an alkylene oxide adduct of amine.

Next, 10 parts by weight of polyvinyl alcohol and 5 parts by weight of carboxymethyl cellulose were dissolved in 140 parts by weight of water to prepare a secondary solution. While vigorously stirring the secondary solution, the primary solution was poured into the secondary solution to form an oil-in-water emulsion. When the size of the oil droplet reached 7.0 μm, stirring was weakened, 100 parts by weight of water at 20 ° C. was added to this emulsion, and then the temperature of the system was gradually raised to 65 ° C. 90
Hold for minutes. To the thus obtained capsule liquid, 80 parts by weight of a 15% aqueous solution of polyvinyl alcohol, 30 parts by weight of carboxy-modified SBR latex as a solid content, and 60 parts by weight of starch particles (average particle size 15 μm) were added. Next, water was added to adjust the solid content concentration to 20% by weight to prepare a color developer layer-forming coating liquid containing microcapsules containing a color developer.

On one surface of the base paper having a basis weight of 40 g / m ² ,
The coating liquid for forming the color forming agent layer described above has a solid content coating amount of 4.0.
It was applied using an air knife coating machine so as to be g / m ² , and the coating film was dried to produce a color former sheet.

[Production of desensitizing ink] The following structure:

[0055]

Embedded image

40 parts by weight of a desensitizing agent containing rosin-modified maleic acid resin (Marquide # 1, manufactured by Arakawa Chemical Co., Ltd.) 2
Add 0 parts by weight and 5 parts by weight of an ultraviolet absorber (Tinuvin 328, manufactured by Ciba Geigy Co., Ltd.), and add 18 parts by an oil bath.
The resin and the ultraviolet absorber were dissolved in the desensitizer by heating to 0 ° C. After dissolution, the product was taken out from the oil bath, and 5 parts by weight of white spindle oil and 5 parts by weight of linseed oil were added to prepare a varnish. After cooling this varnish to about 25 ° C., 30 parts by weight of titanium dioxide, 2 parts by weight of organic bentonite and 2 parts by weight of a 10% by weight ethanol solution of cresol red as an acid / base supporting agent of the present invention are added, and a three-roll mill is added. And kneaded to obtain a desensitizing ink.

Example 2 In Example 1, crystal violet lactone and ethyl p-hydroxybenzoate (0.2 parts by weight / 1 part by weight) were used as a mixture of the electron-donating color former of the present invention and an acidic substance. A desensitizing ink was produced in the same manner as in Example 1 except that a solution dissolved in 2 parts by weight of ethyl acetate was used. The color developer sheet and the color developer sheet were prepared in the same manner as in Example 1.

Comparative Example 1 A desensitizing ink was prepared in the same manner as in Example 1 except that the acid / base support of the present invention was not used. The color developer sheet and the color developer sheet were prepared in the same manner as in Example 1.

[Comparative Test] 1) Detection of Printed Area of Desensitizing Ink The desensitizing ink obtained above was developed on the developer layer of the developer sheet using a business form printer. Offset printing was performed at a color material sheet feed rate of 80 m / min so that the ink print amount (solid content) was 2.0 g / m ² . (Example 1) Immediately after printing the desensitizing ink obtained in Example 1 on the developer layer of the developer sheet, an orange color was developed in the area where the desensitizing ink was printed. As a result, the printed area of the desensitizing ink could be easily confirmed. When the printed area was observed after 24 hours, the color development disappeared completely. (Example 2) When printing was performed in the same manner as above, blue was developed in the area where the desensitizing ink was printed. This allows
The printing area of the desensitizing ink was easily confirmed. When the printed area was observed after 24 hours, the color development disappeared completely. (Comparative Example 1) On the other hand, when the desensitizing ink of Comparative Example 1 was used for printing in the same manner as described above, and then the area where the desensitizing ink was printed was observed in the same manner as above, no color development was observed.
Therefore, the printed area of the desensitizing ink could not be confirmed.

2) Printing of areas where desensitizing ink is not formed and areas where desensitizing ink is formed when combined with a color developing agent sheet (degree of desensitizing effect) Color density of printing in areas where desensitizing ink is not formed The printing prevention effect in the area where the desensitizing ink was formed was not different between the pressure-sensitive recording sheets of Examples 1 and 2 and Comparative Example 1, and showed the same performance.

The above results are summarized in Table 1.

Table 1 ──────────────────────────────────── Substances that decolorize after color development Desensitizing ink Layer color development Desensitizing effect Immediately after printing 24 hours ──────────────────────────────────── Example 1 Cresol Red Orange None Good Example 2 Crystal Violet Blue None Good lactone / p-hydroxybenzoic acid ─────────────────────────────── ────── Comparative Example 1 None None None Good ─────────────────────────────────────

[0063]

The desensitizing ink of the present invention contains a mixture of an acid / base supporting agent or an electron-donating color former and an acidic substance. When such a desensitizing ink is printed on the color developing agent layer of the color developing agent sheet, the printed area is colored, so that the area can be easily detected visually. That is, it is possible to immediately detect the desensitizing ink by printing the desensitizing ink in a desired region of the developer layer of the developer sheet and then simply seeing the desensitizing ink near the printed region. . As a result, it is possible to continuously detect the printing area of the desensitizing ink, which is conventionally performed by the spray checker, while performing printing. Further, since the color of the desensitized ink layer gradually disappears, it is not necessary to perform a decoloring process.

[Brief description of drawings]

FIG. 1 shows a cross section of a typical example of a pressure-sensitive recording sheet of the present invention,
It is a figure which shows typically.

[Explanation of symbols]

 11 Support 12 Developer Layer 13 Desensitizing Ink Layer

Claims (3)

[Claims] 1. A desensitizing ink for a color developer sheet, comprising a desensitizer, a pigment and a binder, wherein the desensitizing ink contains an acid / base indicator or a mixture of an electron donating color former and an acidic substance. Desensitizing ink for developer sheets, which is characterized by 2. The color developer according to claim 1, wherein the acid / base indicator or the electron-donating color former is contained in an amount of 0.05 to 5 parts by weight relative to 100 parts by weight of the desensitizer. Desensitizing ink for sheets. 3. A developer sheet having, on one surface of a support, a developer layer containing an electron-accepting developer capable of forming a color image by contact with an electron-donating color developer, A desensitizing ink layer formed by the desensitizing ink for a developer sheet according to claim 1, which is provided in a partial area of the surface of the developer layer.