JPH08311386A - Lithographic print and ink for lithography used therefor - Google Patents

Abstract

PURPOSE: To obtain a lithographic print, not finding the image at the first glance and capable of providing clear image by scrubbing the surface with pencil and ink for lithography used for the print. CONSTITUTION: This lithographic print is obtained by providing an image by white-based lithographic ink layer on white-based paper and contains 5-60wt.% particulate abrasive material having 0.005-5μm average particle diameter of primary particles in the ink layer and has 5-50% gloss value on the surface of ink layer as 60 deg. mirror gloss. Ink used therefor contains 5-60wt.% particular abrasive agent having 0.005-5μm average particle diameter of primary particles in a solid component in drying. The mixture of one or two or more kinds of materials selected from particles of magnesium carbonate, barium sulfate, alumina, microsilica, titanium oxide, urea resin, an acrylic resin, vinyl chloride resin is especially used as the abrasive agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithographic printing material and a lithographic printing ink used therefor. More specifically, an image such as a pattern or a character is printed on a white paper with the same white lithographic printing ink. The present invention relates to a lithographic printing material in which an image cannot be seen at first glance, but when a surface is rubbed with a pencil, an image portion is deeply colored and an image appears, and a lithographic printing ink used for printing the lithographic printing material.

[0002]

2. Description of the Related Art Conventionally, white ink is printed on white paper so that images such as pictures and characters cannot be seen at a glance.
Printed matter in which the printed area is darkly colored and the image appears when the surface is rubbed with a pencil is commonly called love print or friction print.In most cases, it is printed by the gravure printing method, which is a kind of coloring picture. It was used in applications such as toys. In the present invention, the printed matter will be referred to as a love print hereinafter for the sake of convenience. In order to print such a love print, it is effective that the white ink used is composed of a binder that is relatively easily colored with a pencil and a relatively large amount of white pigment or inorganic particles with a large particle size. This is because the gravure printing method with a wide selection range of ink materials was most suitable for printing such an ink.

However, in the case of gravure printing, although the printing speed can be made relatively high in rotary gravure printing, it takes time and money for plate making and printing plates, resulting in an expensive printing fee and a short delivery time. It is difficult to turn around even in such cases,
Further, the sheet-fed gravure printing has a drawback that the printing speed is low, there is a problem of delivery time in a large lot, and the printing cost is higher than that of the planographic printing. From such a background, the preparation of the plate is simple, the printing speed can be relatively high, and the white ink is used in order to adopt the lithographic printing method which is easy to print with the usual fine patterns and characters. Attempts were made to prepare it as a lithographic printing ink and print it with a lithographic printing machine.However, as described above, the ink contains a relatively large amount of white pigment and inorganic particles with a large particle size. Has low fluidity,
It was not possible to perform stable printing.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and on the premise of adopting a lithographic printing system, the problems are solved and an actual lithographic printing machine is used. Using it, the fluidity of the ink is good, stable printing can be performed without leaving a blank, and when printed on white paper, the ink layer is the same color and the image is not conspicuous,
An object of the present invention is to provide a lithographic print excellent in performance as a love print in which an ink layer is deeply colored and a clear image appears only by rubbing the surface with a pencil or the like, and a lithographic printing ink used therefor.

[0005]

As a result of various studies to solve the above problems, the inventors of the present invention have found that the material and particle size of the particulate matter added to the ink as an abrasive or also as a white colorant. The present invention has been completed by paying attention to the addition amount thereof, and adjusting the compounding ratio of these, the vehicle, and the additives such as the high boiling point solvent and the wax compound. That is, the invention of claim 1 is a lithographic printed material having an image formed of a white lithographic printing ink layer on a white paper, the area including the image being rubbed with a pencil. Is a deep-colored image to appear an image.

According to the second aspect of the present invention, an image formed by a white lithographic printing ink layer is formed on a white paper, and when the area containing the image is rubbed with a pencil, the ink layer portion is colored deeply. A lithographic printed material on which a white image is formed, wherein the white lithographic printing ink layer contains a particulate abrasive and the white lithographic printing ink layer surface has a glossiness according to JIS Z8741 Method 3 (60 degree mirror surface). It consists of a lithographic print characterized by a gloss measurement of 5 to 50%. In addition, claim 3
The invention described in (1) above comprises the planographic printed matter according to claim 2, wherein the primary particles of the particulate abrasive have an average particle size of 0.005 to 5 μm and a content of 5 to 60% by weight.

The invention according to claim 4 is a white lithographic printing ink used for printing the lithographic printing material according to the present invention, wherein the ink has an average particle size of primary particles in a solid content when dried. Add 5 to 6 particulate abrasives with a diameter of 0.005 to 5 μm
The lithographic printing ink is characterized by containing 0% by weight. In the invention of claim 5, the particulate abrasive is one or more selected from particles of magnesium carbonate, barium sulfate, alumina, microsilica, titanium oxide, urea resin, acrylic resin and vinyl chloride resin. The lithographic printing ink according to claim 4, which is a mixture of

(Preferred Embodiments) Preferred embodiments of the lithographic printed material of the present invention and materials used for the lithographic printing ink used therein will be described below. First, the resin used in the vehicle of the lithographic printing ink of the present invention is not particularly limited as long as it is a resin used in lithographic printing ink, and any resin can be used. Specific examples include, for example, resins for oil-based inks such as rosin-modified phenol resin, alkyd resin, and petroleum resin, and ionizing radiation-curable resin materials such as acrylic oligomers and monomers. Particulate abrasives dispersed in a vehicle composed of these resins form an uneven surface on the surface of the ink layer formed by printing, improve the colorability with a pencil, and suppress the increase in the glossiness of the surface. It is added in order to make it as close as possible to the glossiness of the surface. For example, inorganic particulate abrasives such as magnesium carbonate, barium sulfate, alumina, micro silica, titanium oxide, and urea resin, acrylic resin, vinyl chloride resin. Organic particulate abrasives such as

These abrasives can be used alone,
You may mix and use 2 or more types in order to adjust whiteness and the fluidity required for printability. Further, if the above-mentioned abrasive is contained, other abrasives, color pigments and the like may be additionally contained for adjustment. The particle size of the abrasive is preferably such that the average particle size of the primary particles is 0.005 to 5 μm,
Secondary particles should be easily dispersed into primary particles by a disperser such as a three-roll mill used for dispersing in a vehicle during production of a lithographic printing ink.

The amount of the abrasive added is related to the glossiness of the surface of the printed ink layer and the colorability of the printed portion with a pencil. The glossiness of the surface of the ink layer is JIS Z8.
741 Specular gloss measurement method 3 (60 degree specular gloss)
The range of 5 to 50% is also preferable in order to match the glossiness of the surface of the paper. From this point, the solid content at the time of drying the ink should be contained in the range of 5 to 60% by weight. It is preferable to add. When the content of the abrasive is less than 5% by weight, the above glossiness becomes 50% or more,
Even if rubbed with a pencil, the surface of the ink layer is not colored so much that it is not practical. On the other hand, when the content is 60% by weight or more, the colorability of the ink layer surface with a pencil is good, but the fluidity as an ink decreases and the printability of lithographic printing becomes poor, which is not preferable. Further, in this case, the glossiness is 5% or less.

The average particle size of the primary particles of the polishing agent is 0.005.
When the thickness is less than μm, coloring on the surface of the ink layer by a pencil is unlikely to occur, and further, the fluidity required for lithographic printing suitability cannot be imparted, which is not practical. When the average particle size of the primary particles of the abrasive is 5 μm or more, the coloring property of the ink layer surface with a pencil is good, but the PS used in lithographic printing
It is not preferable because the ink receiving portion of the plate is shaved and the printing durability is reduced. In the lithographic printing ink of the present invention, in addition to the above, vegetable oil, an effective wax compound for forming an ink, a dispersant, an additive such as a dryer or a sensitizer, a solvent, etc. may be used, if necessary. You can

Next, the paper used for the lithographic print of the present invention,
That is, as the paper for printing the above lithographic printing ink, white paper is usually preferable. However, the lithographic printing ink of the present invention can be adjusted to the same color, and when colored with a pencil, a colored paper can also be used as long as the difference in shade between the printed portion and the non-printed portion can be clearly discriminated. . Further, when comparing uncoated paper and coated paper as the types of paper, the coated paper can make clear the difference in the density of coloring with a pencil between the printed portion and the non-printed portion of the planographic printing ink of the present invention. Is preferred. The thickness of the paper is not particularly limited and may be freely selected as long as it can be printed by a lithographic printing machine.

The lithographic printing mode using the above lithographic printing ink and paper may be either lithographic printing using dampening water or waterless lithographic printing not using dampening water. As the drying method, any of oxidative polymerization, dryer drying, and curing by irradiation with ionizing radiation such as ultraviolet ray or electron beam irradiation can be used.

[0014]

The lithographic print of the present invention has an image formed by a white lithographic printing ink layer on a white paper, and since the color tone of the paper surface and the printed image are the same, the image is printed as it is. It is difficult to discriminate that the image layer is present, and the ink layer portion is darkly colored and the image appears only when the area including the image is rubbed with a pencil. The white lithographic printing ink layer has an average primary particle size of 0.005 to 5
Since 5 to 60% by weight of the particulate abrasive of μm is contained, the surface is formed in an uneven shape, and the glossiness of the ink layer surface is 5 to 5 according to JIS Z8741 Method 3 (60 degree specular gloss).
Since it can be adjusted to 0% and the gloss and color tone of the surface of the paper can be made substantially the same, the printed image becomes difficult to see and coloring with a pencil becomes easy. Furthermore, by using one or a mixture of two or more selected from particles of magnesium carbonate, barium sulfate, alumina, microsilica, titanium oxide, urea resin, acrylic resin, vinyl chloride resin as the particulate abrasive, the ink The gloss and color tone of the layer surface
It ’s easier to get closer to that of the paper surface,
Further, the coloring property of the ink layer portion with a pencil is also improved.

In the white lithographic printing ink of the present invention, the color tone is adjusted to the color of the white paper, and at the same time, the average particle size of the primary particles in the solid content during drying is 0.005 to 5.
It is configured to contain a fine granular abrasive having a size of μm in the range of 5 to 60% by weight. Therefore, the fluidity suitable for printing is maintained, the printability is good, and the surface of the ink layer after printing is formed by the granular abrasive so as to have fine irregularities. For this reason, not only the color tone but also the glossiness of the surface of the ink layer is brought close to the surface of the paper, the image can be made inconspicuous, and the coloring property with a pencil can be improved.

[0016]

[Creation of planographic printing ink]

(Examples 1, 2, 3, 4, 5) 55 parts of a lithographic ink vehicle (manufactured by The Inktech Co., Ltd.) prepared as described below was added with the respective abrasives shown in Table 1 in respective amounts. Disperse each using a three-roll mill, add 5 parts of wax compound and 0.5 part of cobalt dryer 8% (manufactured by Nippon Kagaku Sangyo) after dispersion, and vehicle No. 5 so that the tack of the ink becomes 10-11. Examples 1 to 5 were adjusted using a solvent (made by Nippon Oil Co., Ltd.) and the total amount was 100 parts.
A lithographic printing ink was prepared. Preparation of vehicle for lithographic ink (manufactured by The Inktech) To 40 parts of rosin-modified phenol resin (KG801 manufactured by Arakawa Chemical Industry), 20 parts of linseed oil and 38 parts of No. 5 solvent (manufactured by Nippon Oil Co., Ltd.) were added and heated to 200 ° C. After melting,
After cooling to 120 ° C, the aluminum chelate (A
2 parts of LCH-50 Kawaken Fine Chemical Co., Ltd.) was added and the temperature was raised again to 200 ° C. for gelation to prepare a gel varnish, which was used as a lithographic ink vehicle.

(Examples 6, 7, 8, 9, 10) 20 parts of epoxy acrylate resin (lipoxy SP-1509 Showa High Polymer), 30 parts of dipentaerythritol hexaacrylate (Kayarad DPHA Nippon Kayaku) were used as vehicles. Each of the abrasives shown in Table 1 was added thereto in an amount, and the sensitizer (IRGACURE 184
(Manufactured by Ciba Geigy) and dispersed using a three-roll mill, and Kayarad DPHA was added and adjusted so that the ink tack was 10 to 11, and the total amount was 100 parts. I made an ink.

(Comparative Examples 1 and 2) 20 parts of alkyd resin (Araquid 5001 manufactured by Arakawa Chemical Industry Co., Ltd.) was used as a vehicle, and each of the abrasives shown in Table 2 was added thereto in respective amounts to use a three-roll mill. After dispersing, 5 parts of wax compound and 0.5 parts of cobalt dryer 8% (Nippon Kagaku Sangyo Co., Ltd.) were added, and the ink tack was 10-11.
Was adjusted using the above vehicle No. 5 solvent (manufactured by Nippon Oil Co., Ltd.) to prepare lithographic printing inks of Comparative Examples 1 and 2 in which the total amount was 100 parts.

(Comparative Examples 3 and 4) 80 parts of the same lithographic ink vehicle (made by The Inktech) as used in Examples 1 to 5 were added with the respective abrasives shown in Table 2 in respective amounts. Add and disperse using a 3-roll mill, then add 5 parts of wax compound, 0.5 parts of cobalt dryer 8% (manufactured by Nippon Kagaku Sangyo Co., Ltd.) and ink tack of 10-1.
A vehicle No. 5 solvent (manufactured by Nippon Oil Co., Ltd.) was adjusted so as to be 1, and the lithographic printing inks of Comparative Examples 3 and 4 were prepared so that the total amount was 100 parts.

(Comparative Example 5) The same vehicle for lithographic ink as used in Examples 1 to 5 (manufactured by The Inktech)
30 parts of the abrasive (calcium carbonate) shown in Table 2 was added to 55 parts.
Parts and dispersed using a three-roll mill, 5 parts of wax compound, 0.5 parts of cobalt dryer 8% (manufactured by Nippon Kagaku Sangyo Co., Ltd.) were added, and the ink tack was 10 to 1
A lithographic printing ink of Comparative Example 5 was prepared by adjusting the amount of vehicle to 1 and using solvent No. 5 (made by Nippon Oil Co., Ltd.) so that the total amount was 100 parts.

[0021]

[Table 1] Abrasives added to the inks of Examples 1 to 10 Note) * 1: Magnesium carbonate (magnesium carbonate TT manufactured by Tokuyama Soda) * 2: Barium sulfate (precipitating barium sulfate manufactured by Sakai Chemical) * 3: Vinyl chloride resin (ZEON 121 manufactured by Nippon Zeon) * 4: Titanium oxide (titanium oxide) SR-1 Ishihara Sangyo) * 5: Acrylic resin (Shin Loihi Color 3SCL made by Shin Roihi) * 6: Microsilica (Erosiel 200 made by Nippon Aerosil) (hereinafter, blank space)

[0022]

[Table 2] Abrasives added to the inks of Comparative Examples 1 to 5 Note) * 4 and * 5 are the same as those in Table 1. * 7: Calcium carbonate (Shirahama T-DD Shiraishi Kogyo)

[Preparation of lithographic printed matter] Using the inks of Examples 1 to 10 and Comparative Examples 1 to 5 prepared as described above, an illustration pattern is coated by a Lithrone 26 type lithographic printing machine (manufactured by Komori Corporation). Paper (basis weight 105 g / m
² Top coat made by Shin-Oji Paper Co., Ltd.) Printed on 5000 sheets. It should be noted that Examples 1 to 5 and Comparative Examples 1 to 5 were printed at a printing speed of 8000 rpm and then naturally dried at room temperature for 24 hours. At the same time, the ink was cured by passing it through an ultraviolet irradiation device of a 120 W / cm high-pressure mercury lamp (two-lamp type) at a speed of 40 m / min to prepare respective lithographic prints.

[Evaluation and Results] Regarding the lithographic printing inks and lithographic prints of Examples 1 to 10 and Comparative Examples 1 to 5 prepared as described above, the printability of the ink during printing,
The conspicuousness of the printed part (image) of the printed matter, the coloring of the printed part with a pencil (difference in coloring between the non-printed part and the printed part), and the 60-degree specular gloss of the printed part (ink layer surface) were evaluated. The results are shown in Table 3 as symbols or measured values.

The evaluation criteria and measuring method are as follows. Ink printability ○: Good printability and good printability x: Ink-related troubles and poor printability ○ Conspicuousness of printed part (image) ○: Inconspicuous △: Slightly conspicuous ×: Conspicuous thing Coloring of printed part with pencil ○: Good coloring of printed part, image is clearly visible ×: Low coloring of printed part and image is unclear Printed part (ink layer surface) ) Specular gloss of 60) JIS Z 8741 (1983) Specular gloss measurement method 3 (60 specular gloss). As the measuring device, a GM-26D gloss meter (manufactured by Murakami Color Research Laboratory) was used. (Below margin)

[0026]

[Table 3] Evaluation results Note) In Comparative Examples 1 and 2, the fluidity of the ink on the lithographic printing press was remarkably inferior, so the printing was stopped halfway and the printability was judged to be poor. Samples were collected and other items were evaluated.

As is clear from the evaluation results in Table 3, the lithographic printing inks and lithographic prints of Examples 1 to 10 of the present invention were good in all the above-mentioned evaluation items, and were suitable for the purpose of the present invention. It was a thing. On the other hand, the lithographic printing inks and lithographic prints of Comparative Examples 1 to 5 are inferior in fluidity of the ink on the lithographic printing machine in Comparative Examples 1 and 2,
It lacks printability, and Comparative Examples 3, 4, and 5
Has a high glossiness of the ink layer surface, colorability with a pencil,
The performance was lacking in terms of the conspicuousness of the printed part. The reason for this is that in Comparative Examples 3 and 4, the content of the abrasive was 5% by weight or less, which was too small, but in Comparative Example 5, the calcium carbonate used as the abrasive was white luster T-.
DD (manufactured by Shiraishi Industry Co., Ltd.), which is for a white pigment, is easily wrapped in a vehicle, has a high glossiness on the surface of the ink layer, and as a result, has a low coloring property with a pencil.

[0028]

EFFECTS OF THE INVENTION Since the lithographic printing material of the present invention and the lithographic printing ink used therefor have the constitutions described in detail above, the following effects can be obtained.
According to the lithographic printed material of the present invention, the surface of the paper and the surface of the printed ink layer, that is, the image surface, are similar in color tone and gloss, so that the presence of the image is not recognized as it is,
By rubbing the surface with a pencil, a printed matter in which the ink layer portion is colored darker than the paper surface and an image appears clearly can be provided easily and with high productivity by lithographic printing. Further, according to the lithographic printing ink of the present invention, a printed matter having the above-mentioned function, which has been conventionally printed by the gravure printing method, can be printed easily by the lithographic printing method with good printing suitability. Also, it is possible to freely carry out the contact printing with the general lithographic printing pattern, easily deal with the short delivery time regardless of the size of the lot, and it is very large that it contributes to the improvement of the productivity.

Front page continuation (72) Kenichi Oshiki 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. (72) Inventor Tomoyuki Goto 450 Aoto-cho, Midori-ku, Yokohama-shi, Kanagawa The Inc. Inside TEC Co., Ltd. (72) Inventor Takahiro Suzuki 450 Aotocho, Midori-ku, Yokohama-shi, Kanagawa The Ink-Tech Co., Ltd.

Claims (5)

[Claims] 1. A lithographic printed material having an image formed of a white lithographic printing ink layer on a white paper, the area including the image being rubbed with a pencil so that the ink layer portion is deeply colored. A lithographic print characterized by the appearance of an image. 2. A lithographic printing plate having an image formed of a white lithographic printing ink layer on a white paper and rubbing a region containing the image with a pencil to darken the ink layer portion to reveal the image. The printed matter, wherein the white lithographic printing ink layer contains a particulate abrasive, and the glossiness of the white lithographic printing ink layer surface is 5 according to JIS Z8741 method 3 (60 degree specular gloss). A lithographic print characterized by being -50%. 3. The lithographic print according to claim 2, wherein the primary particles of the particulate abrasive have an average particle size of 0.005 to 5 μm and a content of 5 to 60% by weight. 4. A white lithographic printing ink comprising 5 to 60% by weight of a particulate abrasive having an average primary particle size of 0.005 to 5 μm in a solid content when dried. A lithographic printing ink characterized by containing. 5. The particulate abrasive is one or a mixture of two or more selected from particles of magnesium carbonate, barium sulfate, alumina, microsilica, titanium oxide, urea resin, acrylic resin and vinyl chloride resin. The lithographic printing ink according to claim 4, wherein