JP2003136830A - Method for forming medical diagnostic image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a medical diagnostic image suitable for a medical diagnosis by using an ink jet recording method. SOLUTION: The method for forming the medical diagnostic image comprises the steps of forming the image on a medical ink jet recording material having at least one ink acceptive layer on a light permeable support, and then providing a transparent resin protective layer on the image surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an image for medical diagnosis in the medical field by using an inkjet recording system.

[0002]

2. Description of the Related Art Silver salt photographs that have been generally used in the medical field so far require wet processing such as development processing, which causes a problem of waste liquid. On the other hand, the inkjet recording method is a complete dry recording method,
It can be said that the recording method is extremely suitable for environmental protection. Further, the ink jet recording method has been attracting attention because it produces less noise, has more flexibility in recording patterns, and can form complex images accurately and quickly.

Recording materials used in the ink jet recording system include many types such as void type mainly composed of inorganic fine particles such as silica and alumina, swelling type mainly composed of water-soluble polymer, and composite type combining them. Recording materials are known.

The void type is one in which a porous ink-receiving layer composed of inorganic fine particles and a hydrophilic binder is provided on a support. For example, JP-A-55-51583 and JP-A-55-51853.
No. 6-157, No. 57-107879, No. 57-10.
No. 7880, No. 59-230787, No. 62-160.
No. 277, No. 62-184879, No. 62-1833.
82 and 64-11877, JP-A-3-215.
08, No. 4-67986, Japanese Patent Publication No. 3-56552,
JP-A-8-132728, JP-A-10-81064,
Dohei 10-119423, Dohei 10-175365
No. 10-203006, 10-21760
No. 1, Doppei 11-20300, Doppei 11-20306
No. 11-34481 and the like.

The swelling type is one in which an ink receiving layer mainly composed of a water-soluble polymer is provided on a support. For example, in JP-A-60-168651, polyvinyl alcohol and polyacrylic acid-based water-soluble polymer are used. The use of hydroxyethyl cellulose in JP-A-60-262685, the use of a mixture of carboxymethyl cellulose and polyethylene oxide in JP-A-61-181679, and the use of water-soluble cellulose and polyvinyl in JP-A-61-193879. The use of a mixture of pyrrolidone, JP-A-62-263084, proposed a receiving layer formed from an aqueous gelatin solution having a specific pH, and JP-A-1-146784 proposed the use of a mixture of gelatin and a surfactant. There is.

As a composite type, a recording sheet in which a swelling layer made of a water-soluble polymer is provided on a void layer made of silica fine particles or alumina sol is disclosed in JP-A-9-323475. Recording sheets having a fine porous ink-permeable layer made of a hydrophobic polymer are disclosed in JP-A-61-35275 and JP-A-62-196.
No. 175, and a recording sheet having a porous layer made of a pigment on a layer made of a water-soluble polymer is disclosed in JP-A Nos. 62-140878 and 62-222887.
No., Dohei 3-72460, Dodai 7-186521,
No. 10-29369 and the like.

Further, it is known to provide a protective layer on the image forming surface after printing on an ink jet recording material to form an image, for example, JP-A-8-118784, JP-A-8-174989, and JP-A-8-174989. 2001-39006,
It is described in Japanese Patent Application Laid-Open No. 2001-213044.

On the other hand, a method for producing an image for medical diagnosis by the ink jet recording system, which is the object of the present invention, is disclosed in Japanese Patent Laid-Open No.
00-94664, JP-A-2000-318302, and JP-A-2000-335104.

In medical practice, the recorded recording material is often used immediately for diagnosis, and
There are many opportunities to come into contact with water. Therefore, it is important that the recorded image does not change even if water adheres within a very short time (for example, within 10 minutes, further within 5 minutes) after printing and recording. The recording material used for the examination is usually stored for a long time, but it is required that the image does not change due to the storage. As described above, in the medical field, it is required that the inkjet recording material can withstand more severe conditions as compared with the environment in which the conventional inkjet recording material is generally used, and a method for producing a medical diagnostic image satisfying this is desired.

In medical diagnosis, a diagnostic image sheet on which an image is recorded is attached to a Schaukasten and observed by transmitted light. At this time, reflected light (return light) of external light (indoor light) other than transmitted light is used. The image may be difficult to see due to glare. Therefore, it is necessary to prevent glare.

[0011]

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a method of producing a diagnostic image suitable for medical diagnosis by using an inkjet recording system.

[0012]

The above object of the present invention is to protect a transparent resin on the image surface after image formation on a medical ink jet recording material provided with at least one ink receiving layer on a light transmissive support. It was basically achieved by a method of creating a medical diagnostic image, which is characterized by the provision of layers.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
According to the present invention, a transparent resin protective layer is provided on the image side after printing on a medical inkjet recording material (hereinafter referred to as a recording material) by an inkjet recording method. The transparent resin protective layer is provided by coating the image surface with various resin solutions such as a thermoplastic resin or a heat-fusible resin that is formed by heating or a resin that is cured by ultraviolet irradiation (eg, bar coater, roll coater, applicator). , A spinner or an inkjet recording device) to form a coating layer, a method of thermally transferring an overcoat resin layer through a heat resistant film, a method of laminating a laminate film, and the like. The transparent resin protective layer thus provided can be irradiated with heat, wind, UV light, microwaves, infrared rays, etc., if necessary.

One of the preferred embodiments of the present invention is to provide the transparent resin protective layer by a method of heating the image surface to 50 ° C. or higher. This further improves the fading on storage. When heated, water and water-soluble organic solvent in the ink remaining on the surface of the image permeate and diffuse inside the ink receiving layer, and the colorant and solvent are more easily separated and the stability of the colorant is increased. Presumed to be. In this case, it is necessary that the amount of solvent remaining on the image surface is small in order to sufficiently obtain the effect of heating, and the ink receiving layer is preferably a layer having a high absorbability of the ink solvent. Therefore, the ink receiving layer is preferably a porous layer mainly containing vapor phase silica, or alumina or alumina hydrate.
Details will be described later. The heating temperature of the image surface is preferably 6
It is in the range of 0 to 250 ° C., more preferably 65 to 20.
It is in the range of 0 ° C. The heating time is related to the heating temperature,
It is 0.1 seconds or more, preferably 0.5 seconds or more. There is no particular upper limit, but there is no difference in effect even if heated for 30 seconds or longer.

Another preferred embodiment of the present invention is to laminate a transparent laminate film on the image side. It may be heated or not at the time of bonding, but it is preferable to heat as described above. As the laminate film, a transparent base material coated with an adhesive or an adhesive is preferably used. Examples of the transparent substrate include various films such as polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyphenylene sulfite, polyether sulfone and polyvinyl chloride. The thickness of the transparent substrate is generally 20 to 200 μm, preferably 30 to 200 μm.
It is about 100 μm. These base materials include benzophenones such as 2-hydroxybenzophenone and 2,4-dihydroxybenzophenone, (2-hydroxyphenyl) benzotriazole, (2-hydroxyphenyl-).
An ultraviolet absorber such as 5-methylphenyl) benzotriazole may be contained.

A heat-sealing type or pressure-sensitive adhesive type resin is preferably used for the pressure-sensitive adhesive or adhesive. As the resin, any of styrene type, butadiene type, acrylic type, urethane type and the like can be used, but acrylic adhesives are preferable, for example, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, Acrylic monomers such as N-methylolacrylamine and copolymers such as ethylene-based monomers and styrene-based monomers copolymerizable therewith can be used.

In the above-mentioned embodiment in which the laminate film is attached to the image surface, the effect of the present invention can be sufficiently exhibited by attaching the laminate film only to the image surface, but the cut surface of the recording material is also covered with the laminate film. Is preferred. The media used for medical diagnosis are usually cut into sheets of a specific size, and air and moisture gradually infiltrate the cut surface of the cut ink-receiving layer during long-term storage, adversely affecting the printed images. May be given. In order to completely prevent this, it is preferable that the cut surface is also integrally covered with the image surface with the laminate film as described above. Specifically, by applying a laminating film of a size larger than the recording material to both the front and back surfaces of the image-recorded recording material and bonding the laminating films on both the front and back surfaces with heat seal or an adhesive, the image surface and the cut surface are separated. A method of integrally coating is adopted. As a result, the image plane and the cut plane are completely blocked from the outside air.

In the present invention, the surface of the transparent resin protective layer coated as described above has a center line average roughness Ra value of 0.1 μm in order to prevent glare due to the reflected light of the room light during examination. It is preferable that the surface is roughened as described above. This surface roughening is performed by pressing the rough surface roller while the coated resin is softened by heating, or by pressing the heated rough surface roller to the resin layer, or by embossing in advance. A method of laminating a roughened laminate film can be adopted. The Ra value of the transparent protective layer is preferably 0.15 μm.
It is at least m, more preferably at least 0.2 μm. The upper limit is about 5 μm.

In the present invention, the surface of the recording material on the ink receiving layer side (image surface, but unprinted portion) preferably has a center line average roughness Ra value of 0.8 μm or less. By setting the Ra value of the image surface to 0.8 μm or less, preferably 0.6 μm or less, the adhesion between the transparent resin protective layer coated on the image surface after image recording and the image surface is improved, and the adhesion is improved. In addition to this, the air remaining between the image surface and the transparent resin protective layer is reduced, so that the image storability is improved. Further, as described above, the Ra value of the image surface of the recording material is 0.
The range of 1 to 0.8 μm is preferable, and 0.15 to 0.8 μm
Is more preferable, and the range of 0.2 to 0.7 μm is particularly preferable. In this case, it is possible to sufficiently prevent glare even if the transparent resin protective layer is not roughened.

The center line average roughness Ra value is in accordance with JIS-B.
It can be measured according to 0601. Specifically, it can be measured using a surface roughness profile measuring instrument, for example, Surfcom 1400D manufactured by Tokyo Seimitsu Co., Ltd. From the measured cross-section curve, a part of the measurement length L is extracted in the direction of the center line, the center line of the extracted part is the X axis, the direction of longitudinal magnification is the Y axis, and the roughness curve is y = f (x). Ra value is expressed in units of micrometers, and
It can be calculated by the formula. The cutoff value is 0.8 mm.

[0021]

[Equation 1]

The recording material used in the present invention has at least one ink receiving layer on the light transmissive support. The structure of the ink receiving layer is not particularly limited, but it is preferable to have at least one porous layer mainly containing inorganic fine particles. As described above, in the medical field, since it is used for diagnosis in a short time after printing and recording, it is necessary that ink does not adhere even if the recorded image is touched immediately after printing. Required. The porous layer is excellent in this respect.

The content of the inorganic fine particles in the ink receiving layer is preferably 50% by weight or more, more preferably 60% by weight or more, based on the total solid content. The inorganic fine particles preferably have an average primary particle size of 30 nm or less, and the average particle size of the secondary particles formed by aggregating these primary particles is 500.
nm or less is preferable. By using such ultrafine particles, the transparency, which is an important performance for medical applications, is advantageously exerted.

Further, since the medical recording material is observed with transmitted light, the image portion needs to have a certain density.
Therefore, it is required to absorb a relatively large amount of ink. Therefore, the content of the inorganic fine particles in the ink receiving layer is preferably 8 g / m ² or more, more preferably 10 to 50 g / m ^2, in particular 13~50g / m ² is preferred. By containing such a large amount of inorganic fine particles, the transparency decreases. Therefore, it is preferable to use smaller inorganic fine particles, and it is more preferable to use inorganic fine particles having an average primary particle diameter of 3 to 20 nm and an average secondary particle diameter of 30 to 400 nm.

Examples of the above-mentioned inorganic fine particles include silica fine particles and alumina fine particles. The silica fine particles are classified into those by the wet method and those by the vapor phase method, depending on the synthesis method. Usually, silica fine particles often refer to wet-process silica. As the wet process silica, silica sol obtained through metathesis of sodium silicate with an acid or the like or an ion exchange resin layer, or colloidal silica obtained by heating and aging this silica sol, and gelation of the silica sol, and by changing the formation conditions thereof Silica gel in which primary particles of several μm to 10 μm are siloxane-bonded to form three-dimensional secondary particles, and further, silica sol, sodium silicate, sodium aluminate, and the like silicic acid obtained by heating are produced. There is a synthetic silicic acid compound as a main component.

Vapor phase silica is also called a dry method as opposed to a wet method, and is generally produced by a flame hydrolysis method. Specifically, a method of burning silicon tetrachloride with hydrogen and oxygen is generally known, but instead of silicon tetrachloride, silanes such as methyltrichlorosilane and trichlorosilane may be used alone or in the form of silicon tetrachloride. It can be used as a mixture with. The vapor phase silica is available from Aerosil Japan and QS from Tokuyama Corporation.
It is commercially available as a type and can be obtained.

In the present invention, vapor phase silica is preferably used among the above synthetic silicas. Vapor phase silica is
Compared with wet process silica, a three-dimensional structure having a high porosity is easily formed, which is preferable. The reason for this is not clear, but it is considered that the density of surface silanol groups has an influence. That is, compared to wet method silica, vapor phase method silica
It is considered that the density of surface silanol groups is low, which results in coarse soft agglomeration (flocculate) and a structure with high porosity.

Among the vapor phase silicas, the average primary particle diameter is preferably 3 to 20 nm. Further, when expressed by the specific surface area by the BET method, vapor-phase method silica having a specific surface area of 100 to 500 m ² / g is preferable.

The BET method referred to in the present invention is one of the methods for measuring the surface area of powder by the vapor phase adsorption method, and is a method for obtaining the total surface area of 1 g of a sample, that is, the specific surface area, from the adsorption isotherm. Nitrogen gas is often used as the adsorbed gas, and the most commonly used method is to measure the adsorbed amount from the change in pressure or volume of the adsorbed gas. The most prominent of the isotherms for multimolecular adsorption are Brunauer, Emmett,
It is a Teller's formula, which is called BET formula, and is widely used for determining the surface area. The surface area is obtained by determining the adsorption amount based on the BET formula and multiplying the area occupied by one adsorbed molecule on the surface.

In the present invention, alumina or alumina hydrate is also preferably used. As the alumina, γ-alumina which is a γ-type crystal of aluminum oxide is preferable,
Of these, δ group crystals are preferable. γ-alumina can reduce the primary particles down to about 10 nm, but normally, secondary particle crystals of several thousands to tens of thousands nm are 300 nm or less with an ultrasonic wave, a high pressure homogenizer, an opposed collision type jet crusher, or the like. Those crushed to some extent are preferable, and those having a particle size of 100 nm or less can be more preferably used.

Alumina hydrate is Al ₂ O ₃ .nH ₂ O
It is represented by the constitutive formula (n = 1 to 3). When n is 1, it represents an alumina hydrate having a boehmite structure, and when n is more than 1 and less than 3, it is an alumina hydrate having a pseudo-boehmite structure. It can be obtained by a known production method such as hydrolysis of aluminum alkoxide such as aluminum isopropoxide, neutralization of aluminum salt with alkali, and hydrolysis of aluminate.

The average particle size of the primary particles of the alumina hydrate used in the present invention is preferably 5 to 50 nm, particularly 5 to 50 nm.
It is preferable to use tabular grains having a thickness of 30 nm and an average aspect ratio (ratio of average particle diameter to average thickness) of 2 or more.

The most preferable inorganic fine particles used in the present invention are the above-described vapor phase silica. By using this vapor phase method silica, extremely preferable results can be obtained in terms of ink absorption capacity, ink absorption speed, and transparency.

In the present invention, gas phase method silica, alumina, or alumina hydrate, which are ultrafine particles as described above, is preferably used in the present invention. In this case, the gloss of the ink receiving layer surface becomes high, The above-mentioned glare easily occurs due to the reflected light. In order to prevent this, it is preferable to adjust the center line average roughness Ra value of the printed surface in the range of 0.1 to 0.8 μm as described above. R
In order to adjust the a value, a method of incorporating fine particles of inorganic or polymer having an average particle diameter of about 3 to 30 μm into the ink receiving layer can be adopted.

In the present invention, it is preferable to use a hydrophilic bander together with the above-mentioned inorganic fine particles. Especially the degree of polymerization is 1
A polyvinyl alcohol having a degree of polymerization of 2000 or more is preferable. Further, polyvinyl alcohol may be used in combination with another hydrophilic polymer. In this case, the content of polyvinyl alcohol is preferably 50% by weight or more of the total hydrophilic polymer. The saponification degree of the polyvinyl alcohol used in the present invention is preferably 70 to 95%.

The content of the hydrophilic binder is preferably in the range of 5 to 40% by weight based on the inorganic fine particles,
In particular, it is preferably used in the range of 10 to 35% by weight.

In the present invention, the ink receiving layer preferably contains a cationic polymer. As the cationic polymer used in the present invention, those known in the art can be used. For example, polyethyleneimine,
Polydiallylamine, polyallylamine, JP-A-59-
No. 20696, No. 59-33176, No. 59-331
77, 59-155088, 60-11389.
No. 60, No. 60-49990, No. 60-83882, No. 60-109894, No. 62-198493, No. 6
3-49478, 63-115780, 63-
280681, JP-A-1-40371, 6-23.
No. 4268, No. 7-125411, No. 10-1937.
No. 76, No. 10-217601 and the like 1
To water-soluble cationic polymer having a tertiary amino group, a quaternary ammonium base, or a phosphonium base. Among these cationic polymers, those having a quaternary ammonium group are preferable.

The weight average molecular weight of the cationic polymer used in the present invention is preferably 10,000 or more, and the upper limit is about 100,000. It is more preferably about 10,000 to 80,000, and by using a cationic polymer in this range, it is effective for the ink absorption rate and the image change to water / alcohol. The content of cationic polymer is
A suitable range is 1 to 20% by weight, preferably 1 to 10% by weight, based on the above-mentioned inorganic fine particles.

The ink receiving layer in the present invention preferably contains various oil droplets in order to improve the brittleness of the film, and such oil droplets have a solubility in water at room temperature of 0.01% by weight. % Or less of a hydrophobic high-boiling organic solvent (eg, liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil) or polymer particles (eg, styrene, butyl acrylate, divinylbenzene, butyl methacrylate, hydroxyethyl methacrylate, etc.) Particles obtained by polymerizing one or more polymerizable monomers) may be contained. Such oil droplets can be preferably used in the range of 5 to 50% by weight based on the hydrophilic binder.

In the present invention, the ink receiving layer may be hardened with an appropriate hardener for the purpose of improving water resistance and dot reproducibility. Specific examples of the hardener include aldehyde compounds such as formaldehyde and glutaraldehyde, ketone compounds such as diacetyl and chloropentanedione, and bis (2-chloroethylurea) -2-hydroxy-4,6-dichloro-1. , 3,5 triazine, a compound having a reactive halogen as described in US Pat. No. 3,288,775, divinyl sulfone, a compound having a reactive olefin as described in US Pat. No. 3,635,718, US N-methylol compounds as described in US Pat. No. 2,732,316, US Pat. No. 3,103,43
Isocyanates such as those described in US Pat.
No. 7,280, 2,983,611, aziridine compounds, US Pat. No. 3,100,704, carbodiimide compounds, US Pat. No. 3,093.
There are epoxy compounds as described in No. 1,537, halogen carboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane, and inorganic hardeners such as chromium alum, zirconium sulfate, boric acid and borate. They may be used alone or in combination of two or more. Among the above hardeners, boric acid and borate are preferable. The addition amount of the hardener is preferably 0.01 to 40% by weight with respect to polyvinyl alcohol.

In the present invention, the film surface pH of the ink receiving layer
Is preferably adjusted to 3 to 5.5. The film surface pH of the ink receiving layer is as described in J. TAPPI paper pulp test method N0.
According to the method described in 49, the surface pH is measured after dropping distilled water on the surface of the ink receiving layer and after 30 seconds.

The pH of the film surface of the ink receiving layer is preferably adjusted at the stage of the coating liquid, but since the pH of the coating liquid and the film surface pH in the coated and dried state do not always coincide with each other, It is necessary to obtain the relationship with the film surface pH in advance by experiments or the like in order to obtain a predetermined film surface pH.

The pH of the coating liquid for the ink receiving layer is selected by appropriately combining acids or alkalis. As the acid, inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid, acetic acid, citric acid,
An organic acid such as succinic acid is used, and as the alkali, sodium hydroxide, aqueous ammonia, potassium carbonate, trisodium phosphate, or an alkali metal salt of a weak acid as a weak alkali is used. As the alkali metal salt of the weak acid, volatile acids such as acetic acid, carbonic acid, hydrogen carbonate, formic acid and propionic acid and salts of alkali metals such as sodium, potassium and lithium are preferable.

The pH of the surface of the ink receiving layer containing the above-mentioned cationic polymer is adjusted to the range of 3 to 5.5, and the transparent resin protective layer of the present invention is further coated, whereby the image bleeds during storage. Can be prevented.

Further, the ink receiving layer preferably contains a water-soluble zirconium compound. For example, zirconium acetate, zirconium nitrate, basic zirconium carbonate, zirconium hydroxide, zirconium carbonate ammonium, zirconium carbonate potassium, zirconium sulfate, zirconium fluoride, zirconium chloride, zirconium chloride octahydrate, zirconium oxychloride, hydroxy chloride. Examples include zirconium. By containing a water-soluble zirconium compound in the ink receiving layer,
The transparency of the recording material using ultra-inorganic fine particles such as vapor phase silica, alumina or alumina hydrate is improved.

In the present invention, the ink receiving layer further comprises a surfactant, a coloring dye, a coloring pigment, an ink dye fixing agent, an ultraviolet absorber, an antioxidant, a pigment dispersant, a defoaming agent and a leveling agent. , Preservative, optical brightener, viscosity stabilizer,
Various known additives such as a pH adjuster can also be added.

In the present invention, the ink receiving layer may be one layer or two or more layers, and the coating method is not particularly limited, and a known coating method can be used. For example, a slide bead system, a curtain system, an extrusion system, an air knife system, a roll coating system, a rod bar coating system and the like are used, but a slide bead system and a slide curtain system are particularly preferably used.

Examples of the light transmissive support used in the present invention include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate, diacetate resins, triacetate resins, nitrocellulose, and cellulose ester resins such as cellulose acetate. Examples of the plastic resin film include polyolefin resin, acrylic resin, polycarbonate resin, polyvinyl chloride, polyimide resin, polysulfone, polyphenylene oxide, cellophane, and celluloid. In particular, a polyester film is preferably used because of its properties such as heat resistance and its price. The thickness of these resin film supports is
It is preferably about 100 to 250 μm from the viewpoint of curling property and handling ease. In particular, for medical purposes, a so-called blue PET film colored in blue is preferably used.

When the coating solution for the ink receiving layer is applied to the above-mentioned plastic resin film support, prior to coating,
Corona discharge treatment, flame treatment, ultraviolet irradiation treatment, plasma treatment and the like are usually performed.

In the present invention, it is preferable to provide a primer layer mainly composed of a synthetic resin on a light transmissive support such as a plastic resin film. After applying the coating liquid for the ink receiving layer on the primer layer, the coating liquid is once cooled (at least 10 seconds) in an atmosphere of 20 ° C. or less, and then at a relatively low temperature (maximum temperature is 60 ° C.).
Drying with air (° C. or lower) is advantageous for transparency and surface film strength.

The primer layer provided on the plastic resin film is mainly composed of synthetic resin. Examples of the synthetic resin include acrylic resin, polyester resin, vinylidene chloride, vinyl chloride resin, vinyl acetate resin, polystyrene, polyamide resin, and polyurethane resin. Among these, acrylic resin, polyester resin, vinylidene chloride resin, and polyurethane resin are particularly preferable. As the acrylic resin, a homopolymer of an alkyl acrylate and an alkyl methacrylate or a copolymer thereof is generally used. As the polyester resin, a polycondensate of a glycol (for example, ethylene glycol, diethylene glycol) and a polybasic acid such as an aliphatic or aromatic dibasic acid is generally used. The vinylidene chloride resin is preferably a homopolymer or a copolymer with an alkyl acrylate, an alkyl methacrylate and / or acrylonitrile.
As the polyurethane resin, a water-dispersed polyurethane emulsion is preferable. These resins can be applied on the support as a solution or aqueous solution of an organic solvent, but are preferably water-dispersible polymers, and are applied on the support as an emulsion or a latex.

These synthetic resins are contained in an amount of 60% by weight or more based on the total solid content of the primer layer.
Preferably, the content is 80% by weight or more. Furthermore, the primer layer contains a surfactant, an isocyanate,
A crosslinking agent such as epoxy, fine particles such as colloidal silica, and water-soluble polymer such as gelatin and polyvinyl alcohol may be contained.

The above-mentioned primer layer is formed on the support by 0.01
It is provided with a film thickness (dry film thickness) of ˜5 μm. It is preferably in the range of 0.05 to 5 μm.

The support of the present invention may be coated with various back coat layers for antistatic properties, transport properties, curl prevention properties and the like. The backcoat layer may contain an inorganic antistatic agent, an organic antistatic agent, a hydrophilic binder, a latex, a curing agent, a surfactant and the like in an appropriate combination.

[0055]

The present invention will be described in detail below with reference to examples, but the contents of the present invention are not limited to the examples.

Example 1 The following light transmissive support was prepared. <Support> A primer layer having the following composition was provided on a polyethylene terephthalate film having a thickness of 175 μm and containing a blue inorganic pigment so that the dry film thickness was 0.3 μm. Primer layer: vinylidene chloride: methyl acrylate: acrylic acid (90: 9: 1, wt%) latex (weight average molecular weight 42000).

An ink receiving layer coating solution having the following composition was coated on the above support with a slide bead coating device and dried. The ink receiving layer coating liquid shown below was prepared to have a silica concentration of 8% by weight, and the coating amount of vapor phase silica was 20 g / m ²
Was applied.

<Ink-Receptive Layer Coating Liquid> 100 parts of vapor-phase process silica (average primary particle size 12 nm, specific surface area 200 m ² / g, average secondary particle size 300 nm) Cationic polymer 3 parts (dimethylmethylallylammonium chloride, average molecular weight) 40,000) Boric acid 4 parts Polyvinyl alcohol 22 parts (Polymerization degree 3500)

The above coating liquid was adjusted so that the pH of the film surface of the ink receiving layer after coating and drying was 4.

<Preparation of Image Sheet A for Medical Diagnosis> A recording image was prepared by printing on the recording material prepared as described above using an ink jet printer and black ink so that the transmission density was 2.0. .

<Preparation of Image Sheet B for Medical Diagnosis> After a recorded image is prepared in the same manner as the image sheet A for medical diagnosis, a polyethylene terephthalate film having a thickness of 10 μm and an ethylene-vinyl acetate copolymer layer having a thickness of 6 μm are formed. The thermal transfer sheet provided with is heated so that the temperature of the image surface at the time of transfer is 73 ° C. to transfer the ethylene-vinyl acetate copolymer layer to the image surface to prepare an image sheet B for medical diagnosis. .

<Preparation of Medical Diagnosis Image Sheet C> After a recorded image is prepared in the same manner as the above-mentioned medical diagnosis image sheet A, an aqueous acrylic emulsion type adhesive is applied to one side of a polyethylene film having a thickness of 8 μm. Using the film coated with 10 g / m ^2, a pressure-sensitive adhesive coated surface of the film was superposed on the image surface and passed through a press roll to prepare a medical diagnostic image sheet C.

With respect to the three types of image sheets produced as described above, image fading during storage was evaluated as follows. The image sheet was left at room temperature and normal humidity for 1 month, and the image residual ratio {(density after leaving for 1 month / concentration before leaving) x 10
0} was obtained and evaluated according to the following criteria. ◎: 95% or more ○: 90% or more and less than 95% △: 85% or more and less than 90% ×: less than 85%

As a result of the test, the image sheet A (comparative example) was x, the image sheet B (invention) was ⊚, and the image sheet C (invention) was ∘.

Example 2 <Preparation of Image Sheet D for Medical Diagnosis> The same recording material as in Example 1 was printed with an ink jet printer and black ink so that the transmission density was 2.0, and the recorded image was recorded. Created. On this image side, a laminated film (a film having an adhesive layer and a thickness of 50 μm: LAMI CORP
Made by ORANTION; LAMINATING FILM)
Laminator (NAKABAYASHI Co.LT
D; PACLAMI PRO; ModelPLP-3
25) and was attached at a heating temperature of 125 ° C. to prepare an image sheet D for medical diagnosis.

<Preparation of Image Sheet E for Medical Diagnosis> A recorded image was prepared in the same manner as the image sheet D, and the image surface and the cut surface were covered with the same laminate film and laminator. That is, a laminate film having a size larger than that of the recording material was applied to both front and back surfaces of the recording material, laminated from both sides, and the cut surfaces of the recording material were also wrapped so as to be wrapped.

Example 1 for the above two types of image sheets
When the image residual rate was evaluated in the same manner as in, both were ◎. Next, the image residual rate when left for 1 month under more severe conditions (temperature 30 ° C., relative humidity 80%) was evaluated. As a result, the image sheet D was ◯, and the image sheet E was ⊚.

Example 3 An image sheet was prepared in the same manner as the image sheet B of Example 1. However, as shown below, the film surface pH of the ink receiving layer
Was changed in the range of 2.5 to 6.5 to prepare four types of image sheets. Medical diagnostic image sheet F-1; Membrane surface pH 2.5 Medical diagnostic image sheet F-2; Membrane surface pH 3.5 Medical diagnostic image sheet F-3; Membrane surface pH 5.0 Medical diagnostic image sheet F-4 Membrane surface pH 6.0

Example 1 for the above four types of image sheets
Image residual rate was evaluated in the same manner as
-1 was good, and image sheets F-2, F-3, and F-4 were good. Further, when the image bleeding when left for 2 weeks under the conditions of a temperature of 30 ° C. and a relative humidity of 90% was evaluated,
The image sheets F-1, F-2, and F-3 had no bleeding, but F-4 had bleeding.

Example 4 An image sheet was prepared in the same manner as the image sheet B of Example 1. However, zirconium acetate is added to the ink receiving layer at 2.5.
Added some. Image fading of the thus-prepared medical diagnostic image sheet G during storage was as good as that of the image sheet B, and the transparency of the image sheet was further improved as compared with the image sheet B.

Example 5 Medical diagnostic image sheets H-1 and H-2 were prepared in the same manner as the image sheet D of Example 2. However, two types of laminated films (two types having different rough surface states) that were embossed so that the surface was rough were used. The center line average roughness Ra value of the laminate film surface of the image sheet H-1 thus produced was 0.3 μm, and the image sheet H-
The Ra value of 2 was 0.6 μm. On the other hand, the Ra value of the image sheet D was less than 0.1 μm. Image sheet H-
Image fading of 1 and H-2 during storage was as excellent as that of image sheet D. Next, a glare state due to an interior light when the image sheet was attached to a Schaucasten (diagnostic light-projecting device) was observed. As a result, the image sheet D showed glare depending on the position of the room light, but the image sheets H-1 and H-2 had no glare under any conditions.

Example 6 Using the same support and the same ink receiving layer coating solution as in Example 1, a recording material (a) was prepared which was coated so that the coating amount of vapor phase silica was 22 g / m ^2. When the center line average roughness Ra value of the image surface of this recording material was measured, the Ra value was less than 0.1 μm.

On the other hand, in order to make the same ink receiving layer coating liquid into a two-layer structure, it was divided into 4 (lower layer): 1 (upper layer), and 0.5 g / gram of polystyrene beads (average particle diameter 17 μm) was further added to the upper layer. The lower layer and the upper layer were simultaneously multi-layered coated on a support similar to the above by a slide bead coating device so that the amount of m ² was added. The total amount of fumed silica applied to the recording material is 22 g / m ² . The Ra value on the image side of the recording material (b) thus produced was 0.5 μm.

Further, a recording material (c) having an Ra value of 1.0 was prepared in the same manner as the above recording material (b) except that the amount of polystyrene beads added to the upper layer was increased.

The three types of recording materials prepared as described above were printed using an ink jet printer and black ink so that the transmission density was 2.0, and recorded images were prepared. Next, heat is applied to a polyethylene terephthalate film having a thickness of 10 μm and an ethylene-vinyl acetate copolymer layer having a thickness of 8 μm so that the temperature of the image surface at the time of transfer is 75 ° C. by applying heat to ethylene-acetic acid. By transferring the vinyl copolymer layer to the image surface, three types of medical diagnostic image sheets I-1 (recording material a), I-2 (recording material b), and I-3 (recording material c) are prepared. did.

The image fading of the three kinds of image sheets produced as described above was evaluated in the same manner as in Example 1 when stored for one month. All the image sheets were good and were good. Further, when the image bleaching was similarly evaluated after extending the storage period to 2 months, the image sheets I-1 and I-2 were ⊚ and I-3 was ∘. In addition, the transparency of I-3 was slightly lower than that of the image sheets I-1 and I-2.

Next, the glaring condition caused by the room light when the image sheet was attached to the Schaucasten (diagnostic light-projecting device) was observed. As a result, the image sheet I-1 showed glare depending on the position of the room light, but the image sheets I-2 and I-3 had no glare under any conditions.

Example 7 The same tests as in Examples 1 to 6 were repeated except that the vapor phase silica of the ink receiving layer was changed to alumina hydrate (average primary particle size 10 nm). As a result, the same results as in Examples 1 to 6 above were obtained.

[0079]

As is apparent from the above examples, it is understood that the storage fading of medical diagnostic images can be greatly reduced by providing the transparent resin protective layer on the image surface. In particular, by covering the resin protective layer while heating the image surface to 50 ° C. or higher, image fading can be further suppressed. Furthermore,
According to the present invention, the cut surface of the recording material is also covered with the resin protective layer integrally with the image surface, whereby the image fading can be dramatically suppressed. Furthermore, the bleeding of the image during storage is improved by containing the cationic polymer in the ink receiving layer of the recording material and adjusting the film surface pH of the ink receiving layer in the range of 3 to 5.5. Furthermore, the transparency required for medical images is improved by incorporating a water-soluble zirconium compound into the ink receiving layer. Further, the glaring caused by the room light when the image sheet is attached to the Schaukasten (diagnostic light-projecting device) causes the center line average roughness R of the surface of the transparent resin protective layer coated on the image surface.
It can be completely prevented by setting the value a to 0.1 μm or more, particularly preferably 0.2 μm or more. Further, by adjusting the Ra value of the image surface of the recording material to preferably 0.1 to 0.8 μm, more preferably 0.2 to 0.7 μm, image fading and glare. Is further suppressed.

Claims (9)

[Claims] 1. A medical diagnostic device characterized in that a transparent resin protective layer is provided on the image surface after image formation on a medical inkjet recording material having at least one ink receiving layer provided on a light-transmissive support. How to create an image. 2. The method for producing an image for medical diagnosis according to claim 1, wherein the transparent resin protective layer is provided by a method of heating at 50 ° C. or higher. 3. The method for producing a medical diagnostic image according to claim 1, wherein the transparent resin protective layer is a laminated film, and the laminated film covers the image surface and the cut surface of the recording material. 4. The method for producing a medical diagnostic image according to claim 1, 2 or 3, wherein the center line average roughness (Ra value) of the transparent resin protective layer is 0.1 μm or more. 5. The center line average roughness (Ra value) of the image surface
Is 0.8 μm or less, the method for producing an image for medical diagnosis according to claim 1, 2 or 3. 6. The method for producing an image for medical diagnosis according to claim 1, wherein the ink receiving layer mainly contains vapor grown silica. 7. The ink receiving layer mainly contains alumina or alumina hydrate.
The method for creating a medical diagnostic image described in 1. 8. The ink-receiving layer contains a cationic polymer and has a film surface pH of 3 to 5.5.
9. The method for creating an image for medical diagnosis according to any one of 8. 9. The method for producing a medical diagnostic image according to claim 6, wherein the ink receiving layer contains a water-soluble zirconium compound.