JP3150749B2 - Ink for flash fixing non-impact printer and preprinted paper using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved ink for a non-impact printer of a flash fixing type and a preprinted paper for a non-impact printer of a flash fixing type using the same. More specifically, the present invention provides a non-impact printer ink by a flash fixing method that absorbs light of a specific wavelength or less but does not substantially absorb near-infrared light, and printing using the black ink. The present invention relates to a preprinted paper which has no thermal influence due to flash irradiation, has significantly improved printer suitability, and can be read by a semiconductor laser beam having a wavelength of 650 to 1000 nm.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic non-impact printer (NIP), an image developed by a toner on a photosensitive drum or a photosensitive belt is transferred onto a printing paper, and the transferred toner image is transferred to a printing paper. A method of fusing by heat and fixing the print paper is used. As a heating method for fixing the toner, a heat roll method in which a heat roll is directly pressed into contact with a toner transfer surface to perform heat transfer heating, or a xenon / heat containing near infrared light is used.
The method can be broadly classified into a flash method in which the toner is directly heated by irradiating the toner transfer surface with a flash light and absorbing the near-infrared light of the toner.

In the former thermal roll method, the printing paper is directly pressed into contact with the transferred toner together with the thermal roll heated to a temperature of about 200 ° C., so that the heat resistance of the paper and the preprinted printing paper When the ink is used, the heat resistance of the ink is required. Paper and ink materials satisfying such requirements have been developed so far, and at present, printing paper having sufficient printer suitability is supplied. On the other hand, the flash method has a feature that the toner or the like that absorbs the near-infrared portion of the flash light is selectively heated, and the majority of the paper and ink constituting the printing paper do not absorb the near-infrared portion. Until now, no special consideration has been given to print paper. By the way, in recent years, the number of non-impact printers using the flash method has rapidly increased, and the use of print paper pre-printed with black ink has increased with the diversification of print paper. Heating by flash irradiation causes a decrease in ink adhesion and a distortion (curl, twist) due to heat of the paper, resulting in a problem of deterioration in printer suitability.

[0004] In order to solve this problem, in a flash fixing type non-impact printer print paper preprinted with black ink, flash fixing using an ink that does not substantially absorb near-infrared light is used as the black ink. Pre-print paper for non-impact printers has been proposed (JP-A-63-144081).
No.).

[0005] However, when the preprinting paper for the non-impact printer of the flash fixing type is used, since ink that does not substantially absorb near-infrared light is used, reading with a semiconductor laser beam having a wavelength of 650 to 1000 nm is not possible. There is a problem that it is not possible, and it is strongly desired to solve all of these problems.

[0006]

SUMMARY OF THE INVENTION In response to such a demand, the present invention provides a flash fixing type non-impact printer which absorbs light of a specific wavelength or less but does not substantially absorb near-infrared light. Ink and preprinted paper printed with this black ink, without thermal effects due to flash irradiation, markedly improved printer suitability, and also readable by semiconductor laser light having a wavelength of 650 to 1000 nm The purpose is to provide.

[0007]

Means for Solving the Problems In order to achieve the above object, the present inventors first examined the emission spectrum of xenon flash light used in a flash fixing device. A peak is observed, and an emission wavelength region is also observed in the visible and near-infrared regions. This indicates that the near-infrared region having a wavelength of 850 nm or more is involved in the thermal fusion of the toner. on the other hand,
As black ink, printing with a high hiding power and high density is required. Except for a very small number of special inks using iron black, etc., those using carbon black as a main pigment are used. Black is also used as a black pigment in gray or dark brown inks.However, there is a marked difference in the behavior to near infrared light between inks containing this carbon black and inks not containing it. I understood.

That is, FIG. 1 shows a black ink containing carbon black (A) and a black ink containing no carbon black (B) [an ink that does not substantially absorb near-infrared light (Japanese Patent Laid-Open No. 63-144081). Gazettes)] are near-infrared reflection spectra measured by applying color to high-quality paper. According to the spectra, both exhibit the same absorption in a wavelength region of 800 nm or less, but in the near-infrared region of 800 nm or more. It was observed that only the former was absorbed and the latter was hardly absorbed. Then, the black ink containing carbon black and the black ink not containing this were respectively spread on high-quality paper, and flash irradiation was attempted. In the ink containing no carbon black, no change was observed in the developed color. However, in the case of an ink product containing carbon black, the temperature of the product product increases, the paper distortion (curl,
When the amount of flash irradiation was further increased, thermal denaturation or scorching occurred on the paper, and it was found that the adhesive strength of the ink film was reduced depending on the type of ink.

FIG. 2C is a reflection spectrum diagram of the near-infrared portion of the paper itself. When the above black ink (B) containing no carbon black was used, no absorption was observed at a wavelength of 650 to 1000 nm, so that it was clarified that it could not be read by a semiconductor laser beam having a wavelength in the same range. . On the other hand, the toner absorbs near-infrared light similarly to the carbon black, but has a small area, and has a small adverse effect on the paper because the latent heat during fusion suppresses a temperature rise. It is supposed that.

[0010] Based on these findings, the present inventors have made 1
Non-impact by a flash fixing method that absorbs light of 000 nm or less but does not substantially absorb near-infrared light.
When printing with the printer ink, it was found that a preprinted paper was obtained which had no thermal effect due to flash irradiation, markedly improved printer suitability, and could be read by a semiconductor laser beam having a wavelength of 650 to 1000 nm. The present invention has been completed.

According to a first aspect of the present invention, there is provided a black ink for a flash fixing type non-impact printer, which absorbs light having a wavelength of 1000 nm or less but does not substantially absorb near-infrared light. This is a fixing type non-impact printer ink.

[0012] The invention of claim 2 of the present invention relates to a carbon black-free black ink obtained by subtractive color mixing of a general color pigment other than carbon black which does not substantially absorb near infrared light. 2. The ink for a non-impact printer according to claim 1, which is a black ink containing a substance that absorbs light of up to 1000 nm.

According to a third aspect of the present invention, in a printing paper for a non-impact printer of a flash fixing type preprinted with black ink, the black ink absorbs light having a wavelength of 1000 nm or less but emits near infrared light. Is a pre-printed paper for a flash fixing type non-impact printer, characterized by using an ink which does not substantially absorb the ink.

According to a fourth aspect of the present invention, there is provided a black ink comprising a carbon black-free black ink obtained by subtractive mixing of a general color pigment other than carbon black which does not substantially absorb near-infrared light. The preprinted paper for a non-impact printer according to claim 3, wherein the preprinted paper is a black ink containing a substance that absorbs light of up to 1000 nm.

The paper material used for the preprint paper of the present invention is not particularly limited, and any paper material conventionally used as a print paper for a flash fixing type non-impact printer can be used.

In the present invention, the black ink used for the pre-printing of the printing paper has a wavelength of 1000.
It is important to use a material that absorbs light of nm or less but does not substantially absorb near-infrared light. Printing paper preprinted with such an ink is hardly thermally affected by flash irradiation in a non-impact printer with a flash fixing method, does not undergo thermal denaturation such as distortion or burning, and has no ink film. In addition to being excellent in printer suitability, such as not causing a decrease in the adhesive strength, it can be read by a semiconductor laser beam having a wavelength of 650 to 1000 nm.

Examples of the black ink that absorbs light having a wavelength of 1,000 nm or less but does not substantially absorb near-infrared light include, for example, carbon black-free ink,
A black ink containing no carbon black, a black ink containing a substance that absorbs light having a wavelength of 600 to 1000 nm, or a carbon black-free ink containing carbon black, the amount of which is 1000 nm.
A black ink containing a small amount of carbon black that does not exhibit absorption in the near infrared region is used. The amount of the carbon black in the black ink containing a small amount of carbon black is 15 to 50% by weight, preferably 15 to 4% by weight of the carbon black-free ink.
0% by weight. 50 carbon black
If the content is not less than% by weight, the above-described thermal influence is exerted by the flash irradiation in the flash fixing type non-impact printer, which is not preferable. If the compounding amount of the carbon black is 15% by weight or less, it is not preferable because it cannot be read by the semiconductor laser light.

Examples of such a carbon black free ink include a black ink prepared by mixing three primary colors of a red pigment, a blue pigment and a yellow pigment, and a black ink using a black pigment other than carbon black. Examples of the three primary color inks include a cyan ink in which red light is absorbed when white light is applied to a coloring material, a magenta ink in which the same green light is absorbed, and a yellow ink in which blue-violet light is absorbed. When the color materials are mixed, the color light decreases, and this is called subtractive color mixing, and it is possible to reproduce all colors in the natural world on the paper surface by the mixing ratio.

Examples of the substance that absorbs light having a wavelength of 600 to 1000 nm include those obtained by coloring the above carbon black and leuco dye with an acidic substance, dyes or pigments,
Alternatively, a mixture thereof can be mentioned.

When the black ink for a non-impact printer of the flash fixing type of the present invention is produced by using the above-mentioned leuco dye, for example, a trade name N manufactured by Yamada Chemical Co., Ltd.
IRBlack78B (absorption wavelength 580 nm, 800-
900nm) and Yamamoto Kasei Co., Ltd., brand name Green
-118 (absorption wavelength 650 nm, 800-900 nm)
KMC-113 [trade name, manufactured by Kureha Chemical Co., Ltd.]
Activated clay or a phenolic resin-based or salicylic acid derivative metal chlorine-developing acidic substance is added to a solution dissolved at a concentration of 5 to 30% in a solvent such as AS-296 (trade name of Nippon Petrochemical Co., Ltd.). The reaction-colored substance is added to the above-mentioned mixed pigment of cyan, magenta and yellow to produce an ink. The amount of the leuco dye at this time may be blended so as to be about 0.3 to 3 g / m ² per unit area of the printed preprinted paper, and more specifically 0.4 to 1 g / m ^2. Although preferred, it is not particularly limited to this range.

The black ink has a visible portion and a near infrared portion (about 6 parts).
(1000 nm to 1000 nm).
It is compatible with MR and OCR devices, and has no absorption over the entire infrared region as in the case of the black ink mainly composed of carbon black as described above, so that it generates very little heat,
No ink damage due to flash fixing lamps.

The black ink for a non-impact printer of the flash fixing type according to the present invention can be produced by using the following infrared absorbing dye or pigment instead of using the above leuco dye. In this case, there is no need to make a reaction product with the developer as described above,
It can be added to a mixed pigment of colors, and the amount thereof may be the same as in the case of using the leuco dye, and is economical.
A desired ink can be obtained by mixing these dyes with cyan, magenta and yellow mixed color pigments in an appropriate amount. In this case as well, since there is no absorption over the entire infrared region, the calorific value is extremely small, and no ink is damaged by the flash fixing lamp, and it is possible to cope with OMR equipment.

Examples of infrared absorbing dyes or pigments Kayasorb Absorption wavelength IR-750 650-800 nm IRG-002,003 800-1700 nm IRG-022,033 850-1250 nm Nippon Kayaku Co., Ltd. SIR series SER 103 930 nm SIR 128 855 nm PA series PA1005 775-900 nm PA1006 780-950 nm manufactured by Midori Kagaku MIR-101, 1011, 1021 854 nm manufactured by Midori Kagaku IRF-950 850-950 nm IRF manufactured by Fuji Photo Film Co., Ltd. 1000 900-1100 nm In addition to the above, there may also be mentioned infrared-absorbing dyes or pigments manufactured and sold by Japan Photographic Pigment Research Institute, Toyo Ink Mfg. Co., Ltd. and the like.

Although there are a small number of OCR and OMR devices that are of the ultraviolet reading type, inks corresponding to these devices can be obtained by appropriately adding a known ultraviolet absorber to the various inks described above. It can be easily inferred that an effective ink is obtained. Examples of the ultraviolet absorber that can be used for this purpose include known ultraviolet absorbers such as salicylic acid, benzophenone, benzotriazole, and cyanoacrylate.

The black ink for a flash fixing type non-impact printer of the present invention thus obtained is
Compared to black ink mainly using carbon black,
It is said that the concealing power and concentration are relatively difficult to obtain, and have not been practically used. However, according to the study of the present inventors, only by slightly increasing the amount of the black ink,
It was found that hiding power and density equivalent to those of the black ink using carbon black were obtained.

Next, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 (D) shows a near-infrared portion reflection spectrum measured by applying the black ink of the present invention to a high-quality paper. According to this, it can be seen that absorption is exhibited in the wavelength region of 1000 nm or less, but hardly absorbed in the near infrared region of 1000 nm or more. FIG. 2 is a partial plan view showing an example of the preprinted paper of the present invention.
Item 4 is configured by printing with the black ink of the present invention. When a non-impact printer is flash-fixed on this paper, the printed portion hardly absorbs near-infrared light, as does the paper surface, so that undesirable phenomena such as curling and scorching do not appear at all, and most OMR and OCR I was able to respond to the equipment.

The black ink of the present invention is generally the type of desired printing paper, printing method, the kind of the printing machine, drying system, used in dispersed ink in bi Hikuru selected appropriately depending on the printing speed. In the present invention, there is no particular limitation on the method of preprinting the black ink on print paper, and any method such as letterpress printing, planographic printing, and gravure printing can be used.

[0028]

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention. Using the following components and following the basic recipe below, Black UV inks for flash fixing non-impact printers of the present invention and inks for comparison were prepared in the same manner as in Examples 1 to 8.

Ingredients: Pigment Oligomer (prepolymer, photopolymerizable low polymer) Monomer (reactive diluent, photopolymerizable monomer) Photopolymerization initiator (sensitizer) Additive (photopolymerization accelerator, polymerization) Inhibitor, adhesion promoter, misting inhibitor, wax)

Pigment 30% Prepolymer Bisphenol A Diglycidyl ether acrylate (BDGEA) 26% Monomer Trimethylolpropane triacrylate (TMPTA) 38% Photopolymerization initiator 4,4'-bisdiethylaminobenzophenone 3% 2,2 '-Dimethoxy-2-phenylacetophenone 3% Stabilizer Methylhydroquinone 0.1%

No. Pigment No. No. 1 Cyan, magenta, and yellow pigments were mixed in equal amounts. 2 No. No. 1 90% + carbon black 10% 3 No. No. 1 80% + carbon black 20% 4 No. No. 1 70% + carbon black 30% 5 No. No. 1 50% + NIR Black78B coloring product 50% No. 6 No. No. 1 30% + NIR Black 78B color-developed product 70% No. 7 No. No. 1 25% + NIR Black78B color-developed product 70% + carbon black 5% 8 No. 125% + PA1006 70% + carbon black 5%

Next, the above No. 1 to 8 inks and a commercially available normal black ink as a reference example at an OC of 70 g / m ² .
Offset printing was performed on R paper so that the ink amount was about 2 g / m ² , the ink was passed through a flash fixing type printer, a resistance test was performed, and a reading test was performed with an OCR reader. Table 1 shows the results.

[0033]

[Table 1] ◎ No problem at all ○ Can be used △ Somewhat poor × No problem

In Comparative Examples 1 and 2, the ink resistance was good, but there was a problem in OCR reading because the amount of carbon black was small. On the other hand, with the commercially available oil-based black ink of Reference Example, significant curl occurred on the paper. In contrast, Examples 1 to 6
When the ink of the present invention is used, the ink resistance is also OCR
The reading was good without any problem.

Example 7 Commercially available oil-based process inks (oxidized polymer) of cyan, yellow and magenta were mixed at a weight ratio of 1: 1: 1.
This was further kneaded and toned to obtain a color tone visually equivalent to that of a commercially available oil-based black ink (oxidative polymerization type using carbon black). The above ink No. of the present invention. 6 (used in Example 4) was similarly prepared. The above-described kneading and toning black ink, commercially available oil-based black ink [Toyo Ink Co., Ltd.] such that the concentration becomes 0.80 ± 0.05 on high quality paper (45 kg of continuous weight).
And the ink No. of the present invention. 6, and the reflection spectrum of the ink-colored product was measured. The results are shown in FIG. In this, A is a commercially available oil-based black ink, B is a kneaded and toned black ink, C is the spectrum of the paper itself, and D is the above ink No. of the present invention. 6 is a reflection spectrum. As can be seen from this figure, the commercially available oil-based black ink shows a flat absorption in the near infrared region, while the kneaded and toned ink has a wavelength of 800 nm.
In the wavelength region of not less than nm, there is almost no absorption. 6 is 1000 nm wavelength
In the above wavelength region, it hardly shows absorption.

[0036]

The ink for a pre-printer for a non-impact printer of the flash fixing type and the pre-print paper using the same according to the present invention are not black inks containing carbon black which absorbs near-infrared light. An improved carbon black-free black ink that does not substantially absorb near-infrared light. The ink absorbs light having a wavelength of 1000 nm or less but does not substantially absorb near-infrared light, and is preprinted using the ink. Preprinted paper which is hardly affected by the heat of the flash irradiation, has no distortion or scorch, and has a wavelength of 650.
It is possible to provide a preprinted paper that can be read by a semiconductor laser beam of up to 1000 nm. In addition, even if a UV ink vehicle is used, the adhesiveness of the film is not reduced, so that it is excellent in printer suitability. Further, since the preprinted paper of the present invention does not need to consider heat due to flash irradiation in this manner, the degree of freedom in designing the paper is large, and it is possible to cope with solid black printing. We can supply what looks good.

[Brief description of the drawings]

FIG. 1 is a near-infrared reflection spectrum diagram of a black ink containing carbon black, a black ink containing no carbon black, and a black ink of the present invention.

FIG. 2 is a partial plan view showing an example of the sheet of the present invention.

[Explanation of symbols]

 A Reflection spectrum of commercially available oil-based black ink B Reflection spectrum of kneading and toning black ink C Reflection spectrum of paper itself D Reflection spectrum of black ink of the present invention 1 Paper 2 Print column 3 Title 4 Items

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C09D 11/00-11/20 B41M 5/26

Claims (4)

(57) [Claims] 1. A black ink for a non-impact printer with a flash fixing method, wherein the ink absorbs light having a wavelength of 1000 nm or less but does not substantially absorb near-infrared light. . 2. A substance which absorbs light having a wavelength of 600 to 1000 nm in a carbon black-free black ink obtained by subtractive color mixing of a general color pigment other than carbon black which does not substantially absorb near-infrared light. 2. The ink for a non-impact printer according to claim 1, wherein said ink is a black ink containing: 3. A printing paper for a flash fixing type non-impact printer preprinted with black ink, wherein the black ink is an ink that absorbs light having a wavelength of 1,000 nm or less but does not substantially absorb near-infrared light. Preprinted paper for a non-impact printer using a flash fixing method, characterized in that it is used. 4. A substance that absorbs light having a wavelength of 600 to 1000 nm in a carbon black-free black ink obtained by subtractive color mixing of a general color pigment other than carbon black, wherein the black ink does not substantially absorb near-infrared light. 4. A preprinted paper for a non-impact printer with a flash fixing method according to claim 3, which is a black ink containing the same.