JP2000248214A - Ink for ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject ink which can be used in general ink jet printers without requiring a special device and can facilitate the follow-up investigations of forged copied articles by adding a specific composition absorbing light excluding visible light. SOLUTION: An ink for ink jet printers contains a composition which absorbs light excluding visible light and has an inherent absorption peak, preferably a plurality of the compositions. The ratio of the absorbance peak of a specific color light in the visible light region to the absorbance peak of a specific color light in the visible light-excluding region is set to a value. For example, a UV light absorbent 1 and a UV light absorbent 2 are added in a specific ratio to set a Pλmax:Pλuv1 ratio, a Pλmax: Pλuv2 ratio, and the like, wherein the Pλmax is the absorbance peak of a specific color absorption wavelength λmax in the visible light region; the Pλuv1 is the absorbance peak of the UV light absorption wavelength λuv1 of the UV absorbent 1; and the Pλuv2 is the absorbance peak of the UV light absorption wavelength λuv2 of the UV absorbent 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink for an ink jet printer containing a composition other than visible light, and more particularly to an ink for an ink jet printer capable of facilitating tracking of a forged print using the ink. Regarding ink.

[0002]

2. Description of the Related Art In recent years, image recording apparatuses capable of copying or duplicating color images, such as color copying machines and color printers, have become extremely high-performance. For this reason, a recorded matter reproduced using this image recording apparatus can obtain a very high-quality color image. In particular, the quality of the recorded matter using the recording apparatus of the ink jet system has been dramatically improved in accordance with the improvement in the performance of the ink. For this reason, there has been a risk that fraudulent creation of, for example, gift certificates, securities, bills, and the like, which should not be copied by using the recording apparatus of the ink jet system, has emerged.

[0003]

SUMMARY OF THE INVENTION However, when a printed material or the like which should not be copied is copied and the copied material is abused, an image forming apparatus such as a copying machine which made the copy is specified. Is effective not only in criminal investigations but also in eliminating motivation for abusing copies.

In order to prevent such misuse of the copied material, a retrospective search from a past patent application as a conventional technique for facilitating the pursuit search of a forged copy printed material is disclosed in, for example, JP-A-6-059601. An image reading unit, an image processing unit, an image generation unit that performs image generation on recording paper based on the image information after the image processing, and an information book that writes various types of information using special ink that cannot be easily recognized visually. An “image forming apparatus” that includes an insertion unit, a detection sensor, and a system controller is disclosed.

[0005] However, in contrast to conventional counterfeit copy prints,
The "image forming apparatus" for facilitating the pursuit operation includes:
It is necessary to write various information patterns on the recording paper using special ink, and a special device is required.
There is a problem that it is difficult to use it for a general inkjet printer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and does not require a special device, can be used in a general ink-jet printer, and is capable of pursuing a counterfeit copy printed matter. It is an object of the present invention to provide an ink-jet printer ink that can facilitate the above.

[0007]

The ink for an ink jet printer according to the present invention is characterized by "containing a visible light composition having a specific absorbance peak outside the visible region" (claim 1). It is.

[0008] Further, the present invention has the following features: (1) having a plurality of the non-visible light compositions (claim 2); and (2) setting a ratio of the absorbance peak to a specific color in a visible region to a specific value (claim 3). And

(Operation) The ink for an ink jet printer according to the present invention contains a composition outside the visible light region having a unique absorbance peak outside the visible region. Manufacturer,
Specific recording information (hidden information) such as a model can be recorded. As a result, it is possible to easily track and search for forged prints.

Further, by including a plurality of the non-visible light compositions, more specific information can be recorded. In addition, the blending ratio of the non-visible light composition can be adjusted so that the ratio with the absorbance peak of a specific color in the visible region is set to a specific value. Can be made.

[0011]

Embodiments of the present invention will be described below. FIG. 1 is a graph showing the relationship between the absorption wavelength and the absorbance in the present invention. The ink used for the ink for an ink jet printer according to the present invention has a composition outside visible light having a unique absorbance peak outside the visible region.
The ink composition can use a plurality of ink compositions, for example, an ultraviolet absorber 1 and an ultraviolet absorber 2. Furthermore, by adjusting the blending ratio of the composition outside the visible light and setting the ratio of the absorbance peak to a specific color in the visible region to a specific value, it is possible to set a unique value for each maker, model, etc. it can. Incidentally, when describing the relationship between the peak of the absorbance with reference to FIG. 1, in FIG. 1, the wavelength at which the absorbance of a particular color absorbance characteristic A in the visible region is maximized is lambda _max, of visible light outside the composition The wavelength at which the absorbance of the absorbance characteristic B is maximum is λ _uv . The peak values of these absorbances are Pλ _max and Pλ _uv , respectively.

[0012] Referring to Te or more in specific settings, for example, the ultraviolet absorber 1, by adding an ultraviolet absorber 2 at a specific ratio, the absorbance of the absorption wavelength lambda _{ma x} of a specific color in the visible region Ratio of the peak of λ to the peak of the absorbance at the ultraviolet absorption wavelength λ _uv1 of the ultraviolet absorbent 1 _{Pλ max} : Pλ
_uv1, the lambda _max ratio of the peak absorbance of ultraviolet absorption wavelength lambda _uv2 by peaks and the ultraviolet absorber 2 of absorbance P [lambda] _max:
P [lambda] _uv2 further, the lambda _uv1 and the lambda _uv2 absorbance peak ratio P [lambda] _uv1: P [lambda] _uv2 and can be set respectively.

The visible light composition having a specific absorbance peak outside the visible region is not specified as an ultraviolet absorbent, but an absorbent having a specific absorbance peak in the infrared region outside the visible region. But it is good. The ratio of these absorbance peaks is constant without being influenced by printing conditions such as the density of the ink.

(Examples) Hereinafter, the present invention will be described in detail with reference to examples, but the scope of the present invention is not limited to the following examples. FIG. 2 is a numerical table of the composition ratio, absorption wavelength, and absorbance ratio of each of the examples and comparative examples of the present invention.

Example 1 0.5% by weight of Irgacure 2959 (manufactured by Ciba Specialty Chemicals) was used as the ultraviolet absorber 1 of the above visible light composition, and 0.1% by weight of benzotriazole was used as the ultraviolet absorber 2 And other components were added at the ratios shown in FIG. The respective absorbance ratios of the ink of this embodiment are as _follows : _{Pλ max} : _{Pλ uv1} is 1: 1.4,
_{Pλ max} : _{Pλ uv2} is 1: 1.7, _{Pλ uv1} : _{Pλ uv2} is 1: 1.2
It is.

(Example 2) Irgacure 2959 (manufactured by Ciba Specialty Chemicals) of UV absorber 1 was used.
1.0% by weight of benzotriazole as ultraviolet absorber 2
5% by weight, and other components were added at the ratios shown in FIG. Each absorbance ratio of the ink of this embodiment is Pλ _max :
_{Pλ uv1} is 1: 1.1, _{Pλ max} : _{Pλ uv2} is 1: 1.3, P
λ _uv1 : _{Pλ uv2} is 1: 1.2.

Example 3 0.05% by weight of benzotriazole as ultraviolet absorber 2 and 0.02% of Irgacure 651 (manufactured by Ciba Specialty Chemicals) as ultraviolet absorber 3
% By weight and other components were added at the ratios shown in FIG. Each absorbance ratio of the ink of this embodiment is Pλ _max : Pλ
_uv2 is 1: 1.3, _{Pλ max} : _{Pλ uv3} is 1: 2, _{Pλ uv2} : _Pλ
uv3 is 1: 1.5.

(Example 4) Irgacure 2959 (manufactured by Ciba Specialty Chemicals) of ultraviolet absorber 1 was used.
0.5% by weight, 0.02% by weight of Irgacure 651 (manufactured by Ciba Specialty Chemicals) as an ultraviolet absorber 3, and other components were added at the ratios shown in FIG. Each absorbance ratio of the ink of the present embodiment is such that _{Pλ max} : _{Pλ uv1} is 1: 1.
4, _{Pλ max} : _{Pλ uv3} is 1: 2, _{Pλ uv1} : _{Pλ uv3} is 1: 1.
4

(Comparative Example) As a comparative example, an example in which no extra-visible light composition was added was given. The composition was as shown in FIG. In the comparative example, since there is no composition other than visible light such as an ultraviolet absorber, there is no absorbance peak outside visible light, and the absorbance peak ratio cannot be calculated. This allows
By using the ink jet printer ink of the embodiment, the peak ratio of the absorbance can be used as hidden information.

[0020]

The ink for an ink jet printer according to the present invention contains a visible light composition having a unique absorbance peak outside the visible region, so that a false print can be obtained.
It is possible to provide an ink for an ink jet printer capable of recording specific recording information that facilitates a tracking search.
Further, by using an ink containing a plurality of compositions other than visible light, it is possible to provide an ink for an ink jet printer capable of recording more specific recording information. Further, it is possible to provide an ink for an ink jet printer capable of adjusting the ratio of the absorbance peak of a specific color in the visible region to a specific value by adjusting the compounding ratio of the composition outside the visible light range and the like.

The ink for an ink jet printer of the present invention has the same characteristics in the visible region as the conventional ink,
There is no deterioration in image quality, and an ink jet printer using this ink can have specific recording information (hidden information) on printed matter without writing an image pattern for information recording. Therefore, it is possible to provide an ink for an ink-jet printer that can use an existing ink-jet printer without having to use a conventional ink-jet printer.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between an absorption wavelength and an absorbance in the present invention.

FIG. 2 is a numerical table of components, absorbance, absorbance ratio and the like of Examples of the present invention.

[Explanation of symbols]

A Absorbance characteristics of specific color in visible region B Absorbance characteristics of composition outside visible light λ _max Absorption wavelength of specific color in visible region λ _uv1 Ultraviolet absorption wavelength of ultraviolet absorber 1 λ _uv2 Ultraviolet region of ultraviolet absorber 2 Absorption wavelength λ _uv3 UV absorption wavelength of UV absorber 3 _{Pλ max} Absorbance peak value of absorption wavelength of specific color in visible region _{Pλ uv1} UV absorber 1 absorption peak value of UV absorption wavelength _{Pλ uv2} UV absorber The peak value of the absorbance at the ultraviolet absorption wavelength of the ultraviolet ray 2 _{Pλ uv3} The peak value of the absorbance at the ultraviolet wavelength of the ultraviolet absorbent 3

Claims (3)

[Claims] 1. An ink for an ink-jet printer comprising a visible light composition having a specific absorbance peak outside the visible region. 2. The ink for an ink jet printer according to claim 1, comprising a plurality of the non-visible light compositions. 3. The ink for an ink jet printer according to claim 1, wherein a ratio of the absorbance peak to a specific color in a visible region is set to a specific value.