JP2002080758A - Printing material for forming image for medical diagnosis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing material for forming images for medical diagnosis, for displaying X-ray images by ink jet printing, making the images stand out and decreasing fatigue feeling in image observation. SOLUTION: This printing material for forming images for medical diagnosis is characterized by being intended for forming images using a pigment ink containing at least Aniline Black as the black pigment. Acetylene Black, phthalocyanine black, nigrosine or Titanium Black is also preferably used as the black pigment instead of the Aniline Black.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a recording material for displaying a medical diagnostic image, particularly an X-ray image, by ink jet recording.

[0002]

2. Description of the Related Art Conventionally, examination methods for providing an image of the inside of a human body include an ultrasonic examination, medical thermography, magnetic resonance imaging, positron emission tomography (PET), and a method using radiation such as X-rays. is there.

A radiographic system which is popular as a medical diagnosis today outputs a radiation image having radiation transmitted through a human body and having internal information of the human body, and uses a so-called intensifying screen (X-ray conversion screen) to produce a silver halide emulsion. Is exposed to the silver halide photographic film. Next, the exposed film is washed and dried after development and fixing to give a silver halide photographic film image that matches the radiation image. Diagnosis is made by looking at the photographic film image, and the silver halide photographic film comprises a silver halide emulsion layer (recording layer) and a transparent support.

On the other hand, in the case of a digital medical image, it is possible to output the image to a display screen or a transparent film hard copy. In recent years, medical image inspection methods (hereinafter, medical image inspection methods indicate various inspection methods that provide images of the inside of the human body) are digital medical images (hereinafter referred to as medical images) suitable for diagnostic evaluation in digital form. Indicates an image obtained by the medical image inspection method).

Examples of medical images that provide images suitable for diagnostic evaluation in digital form include digital subtraction angiography, magnetic resonance imaging, computed tomography,
Computer-assisted radiography.

[0006] Usually, medical images are diagnosed in detail by one or several doctors. That is, the medical images need to be easily viewed in a timely manner, and in many cases there should be no location restrictions. If more detailed observation is required, the evaluation is performed on a display screen. In this case, a display device having a high resolution / high dynamic range is required.

[0007] Due to these various circumstances, a transparent film hard copy is required for diagnosis. Hard copies of digital medical images are provided primarily by laser imagers. Laser imagers usually form a medical image on a recording medium consisting of a silver halide recording layer and a transparent support. This laser imager is composed of a film handling section, a laser exposure section, a development processing section, and a cleaning / drying processing section, and has a considerably complicated configuration. Therefore, currently marketed laser imagers are very expensive devices. As a general method of use, one laser imager is installed at a central location of a hospital, and a system is constructed so that digital medical images obtained by various medical image inspection methods can be connected via an image network and printed. .

That is, a laser imager is systematized as a core of a network. The greatest concern of such a system is that the laser imager cannot output medical images due to a failure of the laser imager or the network. As is well known, medical diagnosis is often time consuming, which is a significant drawback. In many cases, several laser imagers are installed or an emergency line is installed to avoid such a problem. Therefore, it is necessary to install several expensive laser imagers for safety measures. These actions ultimately lead to an increase in medical expenses. In addition, small hospitals have a significant problem in that their use of expensive laser imagers delays their response to digitization. Under the above circumstances, an inexpensive imager is desired.

[0009] By the way, in fields different from the above, image output devices for office and personal computers and word processors have been developed. As an image output method, for example, a wire dot output method, a thermosensitive coloring output method, a heat-sensitive melt transfer output method, a heat-sensitive sublimation transfer output method, an electrophotographic output method, an inkjet output method, and the like have been developed. The main use of these image forming output devices is to output characters, graphics, and the like created by a computer or the like to an opaque support such as paper. In addition, it may be used as a manuscript of an OHP (overhead projector) or the like in conferences or presentations at various conferences.

[0010] Among them, the ink jet recording is a method in which minute droplets of ink are caused to fly according to various operating principles and adhere to a recording film such as paper to record images and characters. It has advantages such as low noise, easy multi-coloring, and the like. Regarding nozzle clogging and maintenance, which has been a problem in the past with this method,
Improvements have been made in both ink and device aspects, and at present it is rapidly spreading in various fields such as various printers, facsimile machines, and computer terminals. For example, it is described in detail in the trend of the ink jet recording technology (Koichi Nakamura, edited by Nippon Kagaku Joho Co., Ltd. on March 31, 1995).

The ink-jet recording material used in this ink-jet recording system (hereinafter, also simply referred to as a recording material) has a high density of print dots, a bright and vivid color tone, a rapid ink absorption, and an overlap of print dots. In general, there is a demand for performance such as that ink does not flow out or bleed, that the diffusion of print dots in the horizontal direction is not excessively large, and that the periphery is smooth and not blurred. . Specifically, those obtained by applying an ink absorbing layer as a recording layer on various supports are generally used. The ink absorbing layer is roughly classified into a so-called swelling type ink absorbing layer mainly composed of a hydrophilic binder and a void type ink absorbing layer having a void layer in a recording layer.

Among them, an ink jet recording material having a void-type ink absorbing layer has a void layer in which voids are formed on a support as an ink absorbing layer by the presence of fine particles in a hydrophilic binder. There is an advantage that it has excellent ink absorbency, is less likely to cause image beading in a high ink area as compared with a swelling type, and has little deterioration in image quality in a high density area.

In recent years, many attempts have been made to improve the image quality obtained by ink jet recording. As one of them, a layer having relatively high transparency can be formed by using fine particles having a low refractive index and a small particle diameter as the fine particles used for forming the void-type ink absorbing layer. In this case, by using silica fine particles having a low refractive index and a small particle size, voids can be efficiently formed, a relatively high glossiness can be obtained, and an image having a high density can be obtained. I know. In addition, various methods for fixing a dye in a binder have been proposed in order to improve the water resistance and moisture resistance of the dye. A particularly effective means is to add a polymer having a tertiary or quaternary nitrogen atom, as disclosed in JP-A-57-36692.
Nos. 53-49113, 58-24492, 63
Nos. 224988, 63-307979, 59-
198186, 59-198188, 60-4
No. 6288, No. 61-61887, No. 61-7258
No. 1, No. 61-252189, No. 62-174184
No. 63-162275, JP-A-6-153798
Numerous methods have been proposed, including the issue number.

If such an office device can be used as an output device, it is possible to provide a medical image forming method which is inexpensive and outputs an image suitable for diagnosis and evaluation in digital form. However, the image obtained by printing medical information with a commercially available black ink has a slightly yellowish tinge, and the X-ray image diagnosis does not allow the image to be seen clearly, resulting in a feeling of fatigue during observation. Was.

[0015]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a recording method for displaying an X-ray image by ink jet recording, by selecting a black pigment used for the ink to enhance the image, and An object of the present invention is to provide an image forming and recording material for medical diagnosis that reduces the feeling of fatigue.

[0016]

The object of the present invention has been attained by a medical diagnostic image forming recording material which forms an image using a pigment ink containing at least aniline black as a black pigment. The effect of the present invention can be obtained by using any one of acetylene black, phthalocyanine black, nigrosine, and titanium black instead of aniline black.

Hereinafter, the present invention will be described in more detail. First, the black pigment contained in the pigment ink will be described.

The acetylene black used in the present invention is produced by maintaining the thermal decomposition temperature of acetylene gas at 2,000 ° C. or higher, preferably at 2200 ° C. or higher. The one described in JP-A-56-90860 is used.
In a preferred embodiment, when the acetylene gas is decomposed, hydrogen gas, an inert gas, or the like is introduced to control the thermal decomposition temperature so that the iodine adsorption amount becomes acetylene black of 20 to 110 mg / g. Yes (3-49
No. 941).

The phthalocyanine black, nigrosine and aniline black used in the present invention are all organic pigments. Phthalocyanine black can be produced, for example, by nitrating, reducing and then oxidizing phthalocyanine. Black is commercially available under the names of Spirit Black 850 (manufactured by Sumitomo Chemical Co., Ltd.) and Diamond Black 2RW (manufactured by Sumika Color Co., Ltd.).

These pigments can be used alone or in combination of two or more. In addition, these pigments may be contained in the ink in an amount necessary for a desired color reproduction, and it is 15% by mass or less based on the total amount of the ink.

The inkjet ink of the present invention has a surface tension of 55 × 10 ⁻⁵ N / cm or less. A surfactant is used to adjust the ink to such a surface tension. Surfactants used include cationic,
Any of anionic, amphoteric and nonionic can be used.

These surfactants can be used alone or as a mixture of two or more kinds. By adding in the range of 0.005 to 0.5% by mass based on the total amount of the ink, the surfactant before the filtration step can be used. The surface tension of the ink is 55 × 10 ⁻⁵ N /
cm or less.

The ink-jet ink of the present invention contains an organic solvent as a humectant in order to prevent drying of the tip of a head nozzle for discharging ink by an ink-jet method. Examples of such organic solvents include alkyl alcohols having 1 to 4 carbon atoms such as methyl alcohol, ethyl alcohol, propyl alcohol, i-propyl alcohol, butyl alcohol, sec-butyl alcohol, t-butyl alcohol and i-butyl alcohol. Amides such as dimethylformamide and dimethylacetamide; ketones or ketoalcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol and propylene glycol; Butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thioethylene glycol, hexylene glycol,
Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as diethylene glycol and 1,5-pentane glycol; glycerin; ethylene glycol methyl
Lower alkyl ethers of polyhydric alcohols such as (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, and triethylene glycol methyl (or ethyl) ether; N-methyl-2-pyrrolidone;
3-dimethyl-2-imidazolidinone and the like.

Of the above, a mixture of at least one high-boiling organic solvent, for example, a polyhydric alcohol such as ethylene glycol, propylene glycol or glycerin, and water is more preferable. The organic solvent is used as a mixture with water. The ratio of water to the organic solvent is 40/60 to 80 / by mass ratio.
20 is preferred.

The ink-jet ink component of the present invention comprises:
A pigment, a dispersant, water and an organic solvent are the main components. In addition, a viscosity adjuster, an antifoaming agent, a penetrant, a fungicide, a pH adjuster, and the like can be added as necessary.

The pigment dispersed in the ink-jet ink is prepared by using a dispersing machine to disperse a dispersion containing at least a disperse dye and / or pigment, a dispersant, water and an organic solvent in order to reduce the maximum particle size to 500 nm or less. Spread. As the disperser, a conventionally known sand mill or the like is used. Glass beads or ceramic beads having a particle size of 1.5 mm or less are used as beads inserted into the disperser in order to adjust the maximum particle size of the disperse dye or pigment to 500 nm or less. Preferably, zirconia beads of 0.5 mm or less are used. The filling rate of the beads placed in the disperser is preferably 80% or more of the internal volume of the disperser. Further, the disk peripheral speed of the disperser is preferably 10 m / sec or more, and the dispersion time
The residence time of the dispersion containing water, dispersant and organic solvent is preferably 60 minutes or more.

The maximum particle size of the pigment in the dispersion liquid dispersed in the ink is, for example, Zeta Seizer 1000 (trade name, trade name).
(Manufactured by Malvern Co., Ltd.).

[0028] The ink is produced through a filtration step. In the filtration step, an ethylene tetrafluoride resin is used as a filter medium. As the tetrafluoroethylene resin, for example, a PTFE type membrane filter manufactured by Advantech Toyo can be used. This filter has a pore size of 3.00.
０．１0.10 μm, porosity 83-68%, mass 2.7.
４4.9 mg / cm ² and thickness 70-80 μm.

[0029] In the filtration process, the ink is 4.9 × 10 ⁴ ~
Preferably, the pressure is increased to 19.6 × 10 ⁴ Pa. The ink sent into the filtration device is once pressurized by a compressor or the like to increase the filtration speed and suppress evaporation of volatile components of the ink.

[0030]

EXAMPLES The present invention will be described below with reference to examples, but embodiments of the present invention are not limited thereto. Unless otherwise specified, "%" in the examples means "% by mass",
“Parts” represents “parts by mass”.

Example 1 (Preparation of coating liquid-1) 180 g of fine-particle silica having an average primary particle size of 12 nm synthesized by a gas phase method was mixed with 180 g of pure water.
and dispersed by a high-speed homogenizer to obtain a blue transparent dispersion liquid-1. In this aqueous silica dispersion-1,
Exemplary cationic polymers (M
or-1) of a 25% aqueous solution was added thereto, and a defoaming agent (manufactured by Sannobuco: SN381) was added in an amount of 0.01% to the coating solution, and dispersed with a high-speed homogenizer for 30 minutes to give a pale transparent dispersion. A liquid was obtained.

[0032]

Embedded image

Next, 1 ml of an aqueous solution of 10% polyvinyl alcohol having an average degree of polymerization of 300 and a saponification degree of 98% was added, and a 5% aqueous solution of polyvinyl alcohol-2 having an average degree of polymerization of 3500 and a saponification degree of 95% (4% ethyl acetate was added). %) 60
0 ml was gradually added, then 100 ml of a 4% borax aqueous solution was added as a viscosity improver, and 20 ml of ethanol was further added. 30 ml of the following Dispersion-1 was added thereto to prepare a coating solution-1.

Dispersion-1 Solution 1 and solution 2 having the following composition were prepared, mixed and dispersed by an ultrasonic dispersing machine.

Solution 1 Liquid paraffin 3.0 g Ethyl acetate 5 mL Solution 2 Gelatin 1.0 g Surfactant (manufactured by Maruzen Pharmaceutical Co., Ltd .: QC-100) 2.8 g Pure water 22 mL <Preparation of recording material 1> 175 μm
The above coating solution-1 is applied on a polyethylene terephthalate (PET) film colored to a thickness of 0.17 and colored blue so that the wet film thickness becomes 240 μm, and then cooled so that the coating film temperature becomes 0 ° C. After that, wind at 40 ° C for 15
The recording material 1 was produced by drying by contacting for 0 second.

(Preparation of Coating Solution-2) Alumina Sol-52
After desalting 0 (manufactured by Nissan Chemical Industries, Ltd.), acetic acid was added to perform peptization. Next, the colloidal sol of the alumina hydrate was concentrated to obtain a 15% solution. On the other hand, polyvinyl alcohol (Kuraray: PVA117) was dissolved in ion-exchanged water to obtain a 10% solution. These two types of solutions are mixed so that the solid content of alumina hydrate and polyvinyl alcohol is 10: 1 by mass ratio, stirred and dispersed, and then boric acid 1 is used as a crosslinking agent for polyvinyl alcohol.
2 parts were added to prepare a coating solution-2.

<Preparation of Recording Material 2> A recording material 2 was prepared in exactly the same manner as in the preparation of the recording material 1 except that coating liquid-2 was used instead of coating liquid-1.

(Preparation of Ink-1) After mixing 2 parts of aminomethylpropanol, 81 parts of pure water, and 5 parts of diethylene glycol, the mixture was heated to 70 ° C. in a water bath, and then slowly diluted with No. 25 aniline black (Tokyo Color Materials Co., Ltd.) 12 parts). After confirming that aniline black was submerged in the liquid, premixing was performed for 30 minutes using a TK homomixer, and then dispersion treatment was performed under the following conditions.

(Dispersion conditions) Disperser: planetary ball mill (manufactured by Felice Japan) Grinding media: zirconia beads (0.75 mm diameter) Media filling rate: 30% Dispersion time: 45 minutes The obtained dispersion is centrifuged. To remove coarse particles.

Next, 8 parts of glycerin, 5 parts of ethylene glycol, 5 parts of ethanol, 0.05 parts of Demol P (manufactured by Kao Corporation), 0.05 part of pure water, and 56.95 parts of pure water were stirred well, and then 25 parts of the aniline black dispersion prepared above was added. did. This is further dispersed again under the condition of 400 MPa with a Nanomizer (manufactured by Nanomizer),
The prepared pigment ink was filtered with a membrane filter.

(Preparation of Ink Cartridge-1) BJF
The ink was extracted from the black ink cartridge of 850 (manufactured by Canon Inc .: inkjet printer), washed with ethylene glycol, and then filled with the previously prepared aniline black pigment ink.

(Preparation of Ink-2 and Preparation of Ink Cartridge-2) Except that aniline black was replaced by acetylene black (FX-35 manufactured by Denka Corporation), ink
Ink-2 was prepared in exactly the same manner as in No. 1 and packed in an ink cartridge in the same manner.

(Preparation of Ink-3 and Preparation of Ink Cartridge-3) Aniline black was converted to phthalocyanine black (Sumitone Cyanine Black 2 manufactured by Sumitomo Chemical Co., Ltd.).
Ink-3 was prepared in exactly the same manner as Ink-1 except that the mixture was changed to a mixture of 67% BX) and 33% aniline black (Diamond Black 2RW, Sumika Color Co., Ltd.), and packed in an ink cartridge in the same manner. It is.

(Preparation of Ink-4 and Preparation of Ink Cartridge-4)
%, Nigrosine 30%, and Titanium Black 20%, except that the mixture was changed to a mixture of Ink-1 and a pigment ink was prepared in the same manner as in Ink-1.

(Preparation of Comparative Ink and Preparation of Ink Cartridge) A pigment ink was prepared in the same manner as in Ink-1, except that aniline black was changed to carbon black (MA600, manufactured by Mitsubishi Chemical Corporation). Packed in a cartridge.

<Preparation and Evaluation of Image> The prepared ink cartridge of the pigment ink was placed in a holder of a black ink cartridge of BJF850 (an ink jet printer manufactured by Canon Inc.), and 1200 × 1200 dpi (2.54
Medical image data of the foot taken with X-rays in the mode of the number of dots per cm
bt (with an information content of bt) was printed on each recording material 1.

Table 1 shows the results.

[0048]

[Table 1]

The image formed by the recording material of the present invention was clearly and clearly visible and almost pure black as compared with the image formed by the comparative recording material.

[0050]

According to the image forming recording material of the present invention, it is possible to obtain a medical diagnostic image which looks clear and clear and is almost pure black.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 2C056 FB01 FC01 2H086 BA01 BA11 BA55 4J039 BA04 BA13 BA29 BA35 BC33 BC51 BC54 BC60 BC68 BE01 CA06 EA19 EA42 GA24

Claims (5)

[Claims] 1. An image forming and recording material for medical diagnosis, wherein an image is formed using a pigment ink containing at least aniline black as a black pigment. 2. An image forming and recording material for medical diagnosis, wherein an image is formed using a pigment ink containing at least acetylene black as a black pigment. 3. An image forming and recording material for medical diagnosis, wherein an image is formed using a pigment ink containing at least phthalocyanine black as a black pigment. 4. An image forming and recording material for medical diagnosis, wherein an image is formed using a pigment ink containing at least nigrosine as a black pigment. 5. An image forming and recording material for medical diagnosis, wherein an image is formed using a pigment ink containing at least titanium black as a black pigment.