JP2003025720A - Manufacturing method for ink jet recording support, ink jet recording film, manufacturing method therefor, and medical image forming method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording film, the ink accepting layer of which does not easily peel off even when being clamped on a shear casten or the like and to which flatting properties on the film viewer are given and a medical image forming method using the same. SOLUTION: The manufacturing method of an ink jet recording support is to heat treat the transparent support under a temperature ranging from the glass transition point Tg ( deg.C) of the support to Tg-40 ( deg.C) for one min to 1,500 hr under the condition that the transparent support is wound about a winding core having the outer diameter ranging from 100 to 1,000 nm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording film, and more particularly to an inkjet recording film for medical image formation and a medical image forming method suitable for displaying an image of the inside of a human body obtained by medical diagnosis. Regarding

[0002]

2. Description of the Related Art Conventionally, as an inspection method for giving an image of the inside of the human body, ultrasonic inspection, medical thermography, magnetic resonance imaging, positron emission tomography (PET), and a method using radiation such as X-rays. There is. Radiographic systems, which are popular as medical diagnostics today, transmit radiation through the human body and output a radiographic image containing internal information of the human body.
A so-called intensifying screen (X-ray conversion screen) converts the silver halide emulsion into a wavelength having sensitivity and exposes the silver halide photographic film. Next, the exposed film is washed and dried after development and fixing, and becomes a silver salt photographic film image corresponding to a radiation image. Diagnosis is made by looking at this silver halide photographic film image.

On the other hand, in the case of digital medical images, it is possible to output the image to a display screen or a transparent film hard copy. Medical image inspection method (hereinafter,
The medical image inspection method refers to various inspection methods that give an image of the inside of the human body), and in recent years, a digital medical image suitable for diagnostic evaluation in a digital form (hereinafter, a medical image is the medical image inspection method). The image obtained by the above) is provided. Examples of medical images that provide images suitable for diagnostic evaluation in digital form include digital subtraction angiography, magnetic resonance imaging, computed tomography, computerized radiography and the like.
Usually, medical images are diagnosed in detail by one or several doctors. That is, medical images need to be easily and timely viewed, and in many cases there should be no location restrictions. If more detailed observation is required, it is evaluated on a display screen. In this case, a display device having high resolution / high dynamic range is required.

Under these circumstances, therefore, transparent film hard copy is required for diagnosis. Hard copies of digital medical images are primarily provided by laser imagers. A laser imager normally forms a medical image on a recording medium consisting of a silver halide recording layer and a transparent support. The laser imager structure is composed of a film handling part, a laser exposure part, a development processing part, and a washing / drying processing part, and has a fairly complicated structure.
Therefore, laser imagers currently on the market are very expensive devices. As a general usage method, one laser imager is installed in a central place of a hospital, and systematized so that digital medical images obtained by various medical image inspection methods can be connected by an image network and printed. .

That is, the laser imager is systematized as the core of the network. The biggest concern of such a system is that the laser imager cannot output a medical image due to a failure of the laser imager or the network.

As is well known, medical diagnosis is often time-consuming, which is a serious problem. In many cases, several laser imagers or emergency lines are installed to avoid such problems. Therefore, it is inevitable to install several expensive laser imagers as a safety measure. These actions will eventually lead to higher medical costs. Furthermore,
In a small hospital, there is also a big problem that an expensive laser imager delays the response to digitization. Therefore, an inexpensive imager is desired in view of the above situation.

By the way, although it is a field different from the above, an image output device of a computer or a word processor has been developed for offices and personals. As an image output system, for example, a wire dot output system, a heat-sensitive color development output system, a heat-sensitive melt transfer output system, a heat-sensitive sublimation transfer output system, an electrophotographic output system, an inkjet output system and the like have been developed. The main use of these image forming and outputting devices is to output characters, figures, etc. created by a computer or the like onto an opaque support such as paper. In addition, OHP at conferences and various conference presentations
It may also be used as a document such as (overhead projector). And as a recent technological trend,
Colorization technology has been developed to emphasize a part of characters and figures.

By the way, in the ink jet recording, minute droplets of ink are ejected by various operating principles to adhere to a recording film such as paper to record images, characters and the like, but relatively high speed and low noise. It has advantages such as easy multicoloring. As the recording material used in this ink jet recording system, those in which an ink absorbing layer is coated 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 the recording layer. Among them, the ink jet recording material having a void type ink absorbing layer has a void layer in which voids are formed by the presence of fine particles in a hydrophilic binder as an ink absorbing layer on a support. It has the advantages that it is excellent in ink absorbency, and that beading of an image in the high ink region is less likely to occur in comparison with the swelling type and image quality is less deteriorated in the high density region.

In recent years, many attempts have been made to improve the image quality obtained by ink jet recording. As one of them, 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, a layer having a relatively high transparency can be formed. It was also found that at this time, voids were efficiently formed by using silica fine particles having a low refractive index and a small particle size, and relatively high glossiness was obtained, and an image with high density was obtained. ing.

In order to improve the water resistance and moisture resistance of the dye, various methods of fixing the dye in the binder have been proposed. Particularly effective means is Level 3 or 4.
Is to add a polymer having a nitrogen atom of the grade,
JP-A-57-36692, 53-49113, 58-24492, 63-224988, 63.
-307979, 59-198186, 59-
1988188, 60-46288, 61-61.
887, 61-72581, 61-25218.
No. 9, No. 62-174184, No. 63-162275.
A large number of methods have been proposed, including Japanese Patent Laid-Open No. 6-153798.

If such an office apparatus can be used as an output apparatus, it is possible to provide a medical image forming method which is inexpensive and digitally outputs an image suitable for diagnostic evaluation.

However, since the support is provided with a layer composed of the hydrophilic resin and the inorganic fine particles on one surface thereof, the humidity change and the
The heat of the Schaukasten causes the film to curl and fluctuates, whereby the ink receiving layer is easily peeled off, and when the ink is continuously caught and removed from the Schaukasten, the receiving layer is easily peeled off. Further, since curling on the Schaukasten makes diagnosis difficult, there remains a problem of eliminating curl of the film after inkjet recording and flatness on the Schaukasten.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a medical image forming method which is inexpensive and digitally outputs an image suitable for diagnostic evaluation, and more specifically, it is used for medical purposes. Handling property that is a problem in the case, that is, the ink-receiving layer is not easily peeled off even if the recording film is slightly rough such as sandwiched between the Schaukasten, and the inkjet recording film having a flatness on the Schaukasten and the medical using the same An object is to provide an image forming method.

[0014]

[Means for Solving the Problems] As a result of continuing diligent studies, we were able to solve the above problems by the following configurations.

(1) The transparent support has an outer diameter of 100 mm or more 1
It is 1 at a temperature from the glass transition point Tg (° C) to Tg-40 (° C) of the support in a state of being wound around a winding core of 000 mm or less.
A method for producing a support for inkjet recording, which comprises heat-treating for minutes to 1500 hours.

(2) A method for producing an ink jet recording film, which comprises coating an ink receiving layer on the outer winding surface of the ink jet recording support obtained by the production method described in (1) above.

(3) The ink receiving layer of the ink jet recording film produced by the production method described in (2) contains silica fine particles having an average primary particle diameter of 5 to 100 nm and a water-soluble resin, and An inkjet recording film, wherein the mass ratio of the fine particles to the water-soluble resin is in the range of 3: 1 to 10: 1.

(4) of the ink jet recording film,
Hold the upper edge of the recorded film in an atmosphere of 23 ° C. and 55% RH, and the amount of warp when hanging is +0.5 cm to −5.
The film for inkjet recording according to (3), wherein the film is cm.

(5) of the ink jet recording film,
When the recorded film is placed on a flat surface in an atmosphere of 23 ° C. and 55% RH, the rising curl is +3 mm to -1.
The film for inkjet recording according to (3) or (4), which has a thickness of 0 mm.

(6) The inkjet recording film as described in any one of (3) to (5), which is a medical image recording film.

(7) A medical image forming method using the ink jet recording film described in (6) above.

The present invention will be described in detail below. The polyester used in the support of the present invention is preferably a polyester having a dicarboxylic acid component and a diol component as main constituents and having film-forming properties. The main constituent dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ether dicarboxylic acid,
Examples thereof include diphenylethanedicarboxylic acid, cyclohexanedicarboxylic acid, diphenyldicarboxylic acid, diphenylthioether dicarboxylic acid, diphenylketone dicarboxylic acid and phenylindanedicarboxylic acid. Further, as the diol component, ethylene glycol, propylene glycol, tetramethylene glycol, cyclohexanedimethanol, 2,2-bis (4-
Hydroxyphenyl) propane, 2,2-bis (4-hydroxyethoxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, bisphenol full orange hydroxyethyl ether, diethylene glycol,
Examples include neopentyl glycol, hydroquinone, cyclohexanediol and the like. Among the polyesters containing these as the main constituents, terephthalic acid and 2,6-naphthalenedicarboxylic acid are used as dicarboxylic acid components from the viewpoints of transparency, mechanical strength, dimensional stability and the like.
As the diol component, a polyester containing ethylene glycol or 1,4-cyclohexanedimethanol as a main constituent is preferable. Among them, polyesters containing polyethylene terephthalate or polyethylene naphthalate as a main constituent, copolymerized polyesters containing terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol, and mixtures of two or more of these polyesters Polyester as a constituent is preferable.

A biaxially stretched polyester film is preferably used in the polyester support used in the present invention. The polyester constituting the biaxially stretched polyester may be copolymerized with another copolymerization component, or may be mixed with another polyester, as long as the effects of the present invention are not impaired. Examples of these are
The dicarboxylic acid component and the diol component mentioned above, or the polyester which consists of them can be mentioned. The polyester used in the present invention may contain an antioxidant such as a hindered phenol compound, a phosphite compound, and a thioether compound. These antioxidants may be used alone or in combination of two or more.

The method for synthesizing the polyester used in the present invention is not particularly limited, and the polyester can be produced by a conventionally known method for producing polyester. For example, a direct esterification method in which a dicarboxylic acid component is directly esterified with a diol component, first a dialkyl ester is used as a dicarboxylic acid component, and an ester exchange reaction is performed between this and the diol component, and this is heated under reduced pressure. A transesterification method in which the excess diol component is removed to perform polymerization can be used.

The thickness of the biaxially stretched polyester support used in the present invention is 60 to 250 μm, particularly 90 to 180 μm.
It is preferably m. The biaxially stretched polyester film used in the present invention preferably has a light transmittance of 50% or more. It is more preferably at least 75%. When the light transmittance is less than the above value, the transparency of the film after recording provided with an ink receiving layer to be described below is lowered and the diagnosability is deteriorated, which is not preferable. The above light transmittance is J
It is measured according to IS-K7105.

Next, a method for producing the biaxially stretched polyester support used in the present invention will be described.

The biaxially stretched polyester support used in the present invention can be prepared by a conventionally known method. For example,
The raw material polyester is molded into pellets, dried with hot air or vacuum dried, melt-extruded, extruded into a film from a T-die, adhered to a cooling drum by an electrostatic application method or the like, cooled and solidified to form an unstretched film. obtain. Then
The obtained unstretched film is heated to a temperature within the range of Tg + 100 ° C. from the glass transition temperature (Tg) of polyester through a plurality of roll groups and / or a heating device such as an infrared heater, and is subjected to single-stage or multi-stage longitudinal stretching. . The longitudinal stretching ratio is usually in the range of 2.5 times to 6 times, and it is necessary to set it in a range in which subsequent transverse stretching is possible. The polyester film uniaxially stretched in the machine direction obtained as described above was added with Tg.
˜Tm−20 ° C. (Tm is the melting point of the polyester film), transverse stretching is performed, and then heat setting is performed. The transverse stretching ratio is usually 3 to 6 times. The heat setting is carried out at a temperature higher than the final transverse stretching temperature and usually within a temperature range of Tm-20 ° C or lower for 0.5 to 300 seconds. At this time, it is preferable to heat-set while sequentially raising the temperature difference in the range of 1 to 100 ° C. in the two or more divided regions. The heat-fixed film is usually cooled to Tg or less, and the clip gripping portions at both ends of the film are cut and wound up. At this time, it is preferable to perform a relaxation treatment in the width direction and / or the longitudinal direction by 0.1 to 10% within a temperature range not higher than the final heat setting temperature and not lower than Tg. The relaxation treatment is not particularly limited and may be performed by a conventionally known means. However, it is preferable to perform these treatments while sequentially cooling in a plurality of temperature regions. More optimal conditions of these heat setting conditions, cooling, and relaxation treatment conditions differ depending on the polyester constituting the film, so by measuring the physical properties of the obtained biaxially stretched film and adjusting appropriately so as to have preferable properties. Just decide.

Since the polyester support used in the present invention is used for a film for ink jet recording for medical diagnostic images, the polyester support is colored blue for the purpose of softening the eyes of an observer, facilitating diagnosis and the like. Preferably.

The method of coloring is not particularly limited, and it is sufficient to add a required amount of a coloring agent at any stage from the polymerization of polyester to the melt extrusion and color it. The method of preparing master pellets, diluting them appropriately and melt-extruding is preferable because the concentration can be easily controlled. This method is effective when fine adjustment of the concentration is required, for example, when the recovered polyester is contained. The concentration of the dye in the master pellet is preferably 10 ² to 10 ⁴ ppm.

The dyes preferably used in the practice of the present invention include, for example, anthraquinone type, azo type, azomethine type, indoaniline type, oxonol type, triphenylmethane type and carbocyanine type dyes, but more preferably used. It is possible to use anthraquinone type dye, and it is preferable to use a dye having an absorption maximum by a spectrophotometer in the range of 570 to 700 nm. For more specific examples of the compound, refer to JP-A-3-231738, page 6, Compound No. 37-No. 40, etc., but particularly preferred specific examples are shown below.

[0031]

[Chemical 1]

In the production of the above-mentioned film, a functional layer such as an antistatic layer, a slipping layer or an adhesive layer may be coated before and / or after stretching. At this time, various surface treatments such as corona discharge treatment and chemical treatment can be applied as necessary. Further, for the purpose of improving the strength, it is also possible to carry out the stretching used for known stretching films such as multi-stage longitudinal stretching, re-longitudinal stretching, re-longitudinal transverse stretching, and transverse / longitudinal stretching. Of course, the clip grips on both ends of the cut film are
After being pulverized or, if necessary, subjected to a treatment such as granulation treatment, depolymerization and repolymerization, it can be reused as a film raw material of the same type or as a film raw material of a different type.

The ink receiving layer of the ink jet recording system (hereinafter referred to as the ink receiving layer) is very rigid because it contains a large amount of inorganic fine particles with respect to the binder, and the ink receiving layer is easily cracked due to a change in curl due to a change in humidity. . In particular, cracks tend to occur when the curl direction reverses, such as when the curl changes from the normal curl to the reverse curl. Here, the normal curl refers to a curl in which both ends of the film rise when the ink receiving layer is turned up, and the reverse curl refers to that both ends of the film rise when the ink receiving layer is turned down.

That is, due to the curl fluctuation, the adhesiveness between the support and the receiving layer is weakened, and the film is peeled off or cracked by the impact of inserting the film into the Schaukasten or the like.
This is troublesome because not only the humidity change but also the curl changes due to the heat when the product is placed in the Schaukasten for a long time. In addition, if the positive curl is strong, the lower end may jump up when observing with the upper end sandwiched by the Schaukasten, which may hinder the diagnosis. It has been found that a preferable state of the diagnostic film on the Schaukasten is a flat state, and if the curl is strong enough to exceed the electrostatic adhesion between the film and the Schaukasten surface, a problem occurs. Therefore, it has been found that a film having a warp amount or a rising curl within the range described below when the ink receiving layer is provided on a support having a resin layer coated on the support can improve the above problems.

The rising curl refers to an average of the heights of the four corners which rise due to the curl of a film cut into four pieces. The method for imparting curl is to use a polyester film to be a transparent support or an inkjet recording film having an ink receiving layer formed on the support so that the ink receiving layer is on the outer side with respect to the outer diameter. By heat-treating from a glass transition point Tg (° C) of the support to a temperature of Tg-40 (° C) for 1 minute to 1500 hours in a state of being wound around a winding core of 100 mm or more and 1000 mm or less, +3 to -10 mm of It gives rise curl.

The warp amount is obtained by the amount of horizontal movement of the lower side of the film, which has the upper side of the film cut into four pieces and is vertically suspended. For a perfectly flat film, the amount of horizontal movement of the lower side with respect to the upper side is zero. The amount of warpage is expressed in cm of the moving amount, where the moving amount in the direction of the recording surface is positive and the moving amount in the direction opposite to the recording surface is negative. A polyester film serving as a transparent support, or an inkjet recording film having an ink receiving layer formed on the support so that the ink receiving layer is on the outer side of the winding, and the core has an outer diameter of 100 mm or more and 1000 mm or less. Glass transition point T of the support in the state of being wound on
1 minute to 1500 at a temperature of g (° C) to Tg-40 (° C)
By heat-treating for a time, a film having a warpage amount of +0.5 to -5 cm is obtained.

The longer the heat treatment time is, the more effective it is. The upper limit of the heat treatment is 1500 hours, and the more preferable heat treatment time is 24 to 200 hours. The heat treatment temperature is from Tg ° C to Tg-40 ° C, more preferably Tg
The effect of the present invention is maximized when the heat treatment is performed in the range of ℃ to Tg -10 ℃ for the above time.

The ink jet recording film of the present invention has a basic constitution comprising a transparent support and a transparent ink receiving layer formed on the support. The ink receiving layer of the present invention is a layer having a three-dimensional network structure having a porosity of 50 to 80%, and the three-dimensional network structure comprises silica fine particles having an average primary particle diameter of 5 to 100 nm and a water-soluble resin, It can be obtained by using the silica fine particles and the water-soluble resin in a mass ratio of 3: 1 to 10: 1.

The silica fine particles forming the secondary particles have an average primary particle diameter of 100 nm or less (preferably 5 to 50 n).
m) and the refractive index is 1.45, and the silica fine particles are used to disperse with a water-soluble resin in an amount in the above range to give a three-dimensional structure in which the secondary particles of the fine particles are chain units. Since a network structure is formed and fine pores are formed in the gaps of the network, a porous film structure having an extremely high porosity and a high light transmittance can be obtained. In general, as the particle size decreases, the surface area per mass (specific surface area) increases, and the influence of particle interaction due to surface characteristics becomes stronger. Therefore, in the sol liquid in which ultrafine particles are highly dispersed in the dispersion liquid, when the particles collide with each other in the dispersion liquid, the probability that the particles will adhere to each other due to the electrical characteristics of the surface or hydrogen bonding increases, that is, the particles to each other. The so-called flocculation (soft agglomeration state) with a small number of contact points is generated, and a wet gel is formed with a three-dimensional network structure in which these are connected. When this is dried and the dispersion liquid evaporates, fine voids are formed in the three-dimensional network (mesh) structure to form a porous xerogel. This is an application of a method called a sol-gel method in a broader sense, and the formation of the ink receiving layer of the present invention also utilizes this. The formation of fine voids in this three-dimensional network structure becomes more remarkable as the particles become smaller, and particularly silica fine particles having an average primary particle diameter of 100 nm or less (and an amount within the above range) can be dissolved. It is possible to form a transparent porous film having a small pore diameter of 100 nm or less and a large porosity, in which a light scattering is small. Since the silica particles are easily attached to each other by hydrogen bonds due to silanol groups on the surface, the average primary particle diameter is 100 as described above.
nm or less (preferably 30 nm or less, particularly preferably 3 nm)
In the case of 10 nm), a structure having a large porosity can be formed. Silica particles are roughly classified into a wet method and a dry method depending on the production method. In the wet method, a method in which activated silica is generated by acid decomposition of a silicate, the activated silica is appropriately polymerized, coagulated and precipitated to obtain hydrous silica, is the mainstream. On the other hand, dry method silica is a method by high-temperature gas phase hydrolysis of silicon halide (flame hydrolysis method), a method in which silica sand and coke are heated and reduced and vaporized by an arc in an electric furnace, and this is oxidized by air ( The main method is to obtain anhydrous silica by the arc method). These hydrous silicas and anhydrous silicas have different properties due to the difference in the density of silanol groups on the surface and the presence / absence of pores, but in the case of anhydrous silicic acid (anhydrous silica), a three-dimensional structure with a particularly high porosity is formed Easy to do and preferable. The reason for this is not clear, but when the density of silanol groups on the surface is 5 to 8 particles / nm ^{2 in} the case of hydrous silica, it is easy for particles to aggregate densely, and in the case of anhydrous silica on the other hand, it is 2-3 Pieces / nm
^Since it is as small as ² , it is presumed that coarse soft aggregation (flocculate) occurs and the structure has a high porosity. As the silica fine particles used in the present invention, it is most preferable to use anhydrous silica fine particles produced by a gas phase method. The above three-dimensional network structure is preferably formed by connecting secondary particles having a particle size of 10 to 300 nm in which silica fine particles are aggregated, and more preferably 20 to 100 nm. The porosity of 50 to 80% of the three-dimensional network structure is preferably 56 to 80%, and the pores forming the porosity are 5 to 100%.
It is preferable to have an average diameter (average pore diameter) of nm, particularly preferably 10 to 50 nm. The volume of pores (pore volume) is preferably 0.5 to 0.9 ml / g, more preferably 0.6 to 0.9 ml / g. Furthermore, the specific surface area of the ink receiving layer is preferably in the range of 100 to 250 m ² / g, especially 120~200m ² / g are preferred.

The light transmittance of the ink receiving layer is 70%.
The above is preferable. In addition to silica fine particles, the following materials may be used as long as the object of the present invention is not impaired. As the fine particles used, those having a refractive index of 1.40 to 1.60 are preferable from the viewpoint of not decreasing the transparency, and for example, colloidal silica, calcium silicate, zeolite, kaolinite, halloysite, muscovite, talc, carbonic acid. Examples thereof include calcium and calcium sulfate.

Further, an antifoaming agent may be added to prevent defects during application of the working liquid. As the defoaming agent of the present invention, various generally known defoaming agents, for example, oil-based, fatty acid-based, fatty acid ester-based, alcohol-based, ether-based, phosphoric acid ester-based, amine-based, amide-based, metal soap Although a system, a sulfuric acid ester system, a silicon system etc. can be used, a fatty acid ester system, an ether system, a metal soap system, a silicon system is especially preferred, and a silicon system is especially preferred. You may use these individually or in combination of 2 or more types.

In the ink jet recording film of the present invention, as the hydrophilic binder used in combination with the above-mentioned inorganic fine particles, polyvinyl alcohol and its derivatives, polyalkylene oxide, polyvinyl pyrrolidone, polyacrylamide, gelatin, hydroxylethyl cellulose, carboxymethyl cellulose, Although pullulan, casein, dextran and the like can be used, it is preferable to use a hydrophilic binder having a low boiling point organic solvent contained in the ink and water and a low hydrophilicity, from the viewpoint of film strength immediately after printing.

In the present invention, polyvinyl alcohol or a derivative thereof is preferable because of its film-forming property. Among them, the average degree of polymerization is preferably 1000 or more, and most preferably 2000 or more. The saponification degree is preferably 70 to 100%, particularly preferably 80 to 100%.

Two or more of the above hydrophilic binders may be used in combination, but even in this case, it is preferable to contain at least 50% by mass of polyvinyl alcohol or its derivative. Examples of the polyvinyl alcohol derivative include cation-modified polyvinyl alcohol, anion-modified polyvinyl alcohol, and nonion-modified polyvinyl alcohol. The cation-modified polyvinyl alcohol is obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate. Examples of the ethylenically unsaturated monomer having a cationic group include trimethyl (2-acrylamide-
2,2-Dimethylethyl) ammonium chloride, trimethyl (3-acrylamido-3,3-dimethylpropyl) ammonium chloride, N-vinylimidazole, N-vinyl-2-methylimidazole, N- (3-
Examples thereof include dimethylaminopropyl) methacrylamide, hydroxylethyltrimethylammonium chloride, trimethyl (methacrylamidopropyl) ammonium chloride and N- (1,1-dimethyl-3-dimethylaminopropyl) acrylamide. The ratio of the cation-modified group-containing monomer of the cation-modified polyvinyl alcohol is 0.1 to 10 mol%, preferably 0.2 to 5 mol% with respect to vinyl acetate. The degree of polymerization of the cation-modified polyvinyl alcohol is usually 500 to 4000, preferably 1000 to 4000. The saponification degree of the vinyl acetate group is usually 60 to 100 mol%, preferably 70 to 99.
Mol%. Anion-modified polyvinyl alcohol is
For example, polyvinyl alcohol having an anionic group as described in JP-A 1-206088,
JP-A-61-237681 and 63-30797
A copolymer of vinyl alcohol and a vinyl compound having a water-soluble group as described in JP-A No. 9-90, and a modified polyvinyl alcohol having a water-soluble group as described in JP-A-7-285265. Can be mentioned. Examples of the nonion-modified polyvinyl alcohol include polyvinyl alcohol derivatives obtained by adding a polyalkylene oxide group to a part of vinyl alcohol as described in JP-A-7-9758, JP-A-8-2.
Examples thereof include block copolymers of a vinyl compound having a hydrophobic group and vinyl alcohol described in Japanese Patent No. 5795. The ratio of the inorganic fine particles to the hydrophilic binder in the void layer of the inkjet recording material of the present invention is 3 by mass.
It is preferably double or more in order to obtain high porosity and high film strength.

From the same viewpoint, the more preferable ratio of the inorganic fine particles to the hydrophilic binder is 6 or more. The upper limit of the ratio of the inorganic fine particles to the hydrophilic binder is preferably about 8 or less from the viewpoint of the cracking performance of the film. It is the purpose of the present invention to improve the film-forming property of the void layer, the water resistance of the film, and the addition of a hardening agent capable of crosslinking with the hydrophilic binder in the void layer of the ink jet recording film of the present invention. It is preferable in that the film strength after printing is improved. Examples of such hardeners include organic hardeners containing an epoxy group, an ethyleneimino group, an active vinyl group, and the like, and inorganic hardeners such as chrome alum, boric acid, and borax. Especially when the hydrophilic binder is polyvinyl alcohol, an epoxy type hardener having at least two epoxy groups in the molecule, boric acid or a salt thereof, and borax are preferable. As boric acid, not only orthoboric acid but also metaboric acid, tetraboric acid, etc. can be used. The amount of the hardener added is usually 1 to 200 per 1 g of the hydrophilic binder.
mg, preferably 2-100 mg. The void layer of the inkjet recording film of the present invention preferably contains a cationic polymer for the purpose of improving the water resistance and bleeding resistance of the image. As the cationic polymer used in the present invention, for example, a cationic polymer having a primary to tertiary amino group and a quaternary ammonium base can be used, but it is less likely to cause discoloration with time and deterioration of light resistance, and a dye. A cationic polymer having a quaternary ammonium salt group is preferable because of its high fixing property.

Further, if necessary, JP-A-57-366 can be used.
No. 92, Basic Latex Polymer, Japanese Patent Publication No. 4-1
No. 5744, JP-A Nos. 61-58788 and 62-17.
Polyallylamine described in Japanese Patent No. 4184, etc.
A weak alkali metal acid salt described in JP-A-1-47290 can be used in combination. The cationic polymer preferably used in the present invention is obtained as a homopolymer of the following monomer having a quaternary ammonium salt group or a copolymer with another monomer. Next, specific examples of monomers having a quaternary ammonium salt group that are preferably used will be given.

[0047]

[Chemical 2]

[0048]

[Chemical 3]

Specific examples of the monomer copolymerizable with the above-mentioned monomer will be given below, but the present invention is not limited thereto.

[0050]

[Chemical 4]

[0051]

[Chemical 5]

Specific examples of the cationic polymer having a quaternary ammonium salt group which is preferably used are given below, but the present invention is not limited thereto. The numbers indicate the mole percentage of monomer.

[0053]

[Chemical 6]

[0054]

[Chemical 7]

[0055]

[Chemical 8]

The cationic polymer may be water-soluble or latex particles obtained by emulsion polymerization, but in the present invention, it is preferable to use a water-soluble cationic polymer.

Among the water-soluble cationic polymers, cationic polymers having an average molecular weight of 50,000 or less are preferred because they are less likely to aggregate with the inorganic fine particles and the glossiness is less likely to deteriorate. More preferably, the average molecular weight is 30,000 or less. The lower limit of the average molecular weight is not particularly limited, but is about 2000 or more in terms of water resistance and moisture resistance. The average molecular weight here is a number average molecular weight, and refers to a polystyrene conversion value determined by gel permeation chromatography. It is preferable that the above-mentioned cationic polymer is 0.5 times or more in mass ratio with respect to the hydrophilic binder used in the recording layer, since sufficient water resistance and moisture resistance can be obtained. Also,
Due to the film forming property of the void layer and the like, it is preferably 2 times or less. The upper limit of the amount used is not particularly limited, but is preferably 3 g / m ² or less from the viewpoint of ink absorbency, curl of the recording film, and the like.

The void layer of the ink jet recording film of the present invention may contain various liquid droplets or polymer latex in order to improve the brittleness of the film after coating and drying. Such droplets are, for example, liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, which have a solubility in water of about 0.
01% by mass or less of a hydrophobic high-boiling organic solvent, for example, styrene, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, divinylbenzene, hydroxyethyl methacrylate, etc. A polymer latex obtained by emulsification and dispersion can be added.

Such droplets and latex particles can be preferably used in an amount of 10 to 50% by mass based on the hydrophilic binder. For prevention of cracks and brittleness of the film, it is also preferable to include polyols having a molecular weight of 300 or less. Examples of such polyols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, glycerin, 1,6-hexanediol, and polyethylene glycol having a molecular weight of 300 or less.

If desired, various additives can be incorporated in any layer on the ink receiving layer side of the ink jet recording film of the present invention. For example, JP-A-57
-74193, 57-87988 and 62-261476, the ultraviolet absorbers described in JP-A-57-74192, 57-87989, 60-72785 and 61- No. 146591, Japanese Patent Laid-Open Nos. 1-95091 and 3-13376.
Anti-fading agents, various anionic, cationic or nonionic surfactants described in JP-A-59-4.
No. 2993, No. 59-52689, No. 62-
280069, 61-242871, and JP-A-4-219266, optical brighteners, sulfuric acid, phosphoric acid, acetic acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, etc. Various known additives such as a pH adjusting agent, a lubricant such as diethylene glycol, an antiseptic, a thickener, an antistatic agent, a matting agent and the like can be contained.

In the ink jet recording film of the present invention, the amount of coating solid content on the ink receiving layer side is 5 to 40 g /
m ² is preferable, and 10 to 30 g / m ² is more preferable. The dry film thickness of the inkjet recording film of the present invention is determined by the porosity of the film and the required amount of voids, and is generally 15 μm or more, preferably 20 μm or more. The void volume of the ink receiving layer of the inkjet recording film of the present invention is preferably 10 to 40 ml per 1 m ² of the recording material, and more preferably adjusted to a range of 15 to 30 ml. However, the void volume is J. TAPPI paper pulp test method No. 51-87 When measuring the ink absorptive side of the recording material by the method described in the liquid absorptivity test method for paper and paperboard (Bristow's method), the liquid transfer amount (ml / m ² ) at the absorption time of 2 seconds was measured. expressed. Although the liquid used at this time is pure water (ion-exchanged water), it may contain less than 2% of a water-soluble dye in order to facilitate the determination of the measurement area. The recording material of the present invention may have two or more recording layers having the above-mentioned void layer. In this case, 2
The ratio of the inorganic fine particles to the hydrophilic binder in the void layer of at least one layer may be different from each other. In addition to the above-mentioned void layer, it may have no void layer, or may have a layer swelling with ink together with the void layer. Such a swelling layer may be provided on the lower layer of the void layer (the side closer to the support) or on the upper layer of the void layer (the side away from the support), and when there are two or more void layers, the void layer. May be provided between.

A hydrophilic binder is usually used for the swellable layer, and examples of the hydrophilic binder used here include the hydrophilic binder used for the void layer. On the side opposite to the side having the ink receiving layer of the ink jet recording film of the present invention, various kinds of back layers are provided in order to further prevent curling and sticking when superposed immediately after printing and ink transfer prevention. It is preferable to provide. The structure of the back layer depends on the type and thickness of the support,
A hydrophilic binder or a hydrophobic binder is generally used, though it varies depending on the constitution and thickness of the ink receiving layer. The thickness of the back layer is usually in the range of 0.1 to 10 μm.
Further, the back layer may have a roughened surface in order to prevent sticking to other recording materials, improve writing properties, and further improve transportability in an inkjet recording apparatus. For this purpose, organic or inorganic fine particles having a particle size of 2 to 20 μm are preferably used. Therefore, as a preferred embodiment of the present invention, inkjet recording having at least one void layer containing at least a hydrophilic binder, inorganic fine particles having an average particle size of 100 nm or less, a cationic polymer and an antifoaming agent on a polyester support. Film.

Next, a method for producing the ink jet recording film of the present invention will be described. The inkjet recording film of the present invention can be obtained by applying at least the void layer of the present invention onto a support and drying it. It can be obtained by adding a suitable solvent such as water, alcohol, or various organic solvents to the material for forming the void layer, coating the material on the support, and drying. In order to obtain the effects of the present invention, the viscosity at the time of preparing the coating solution is important, and it is possible to obtain a sufficient effect by adjusting the viscosity to preferably 100 cp or less, more preferably 50 cp.

The temperature of the coating liquid when the ink-jet recording film of the present invention is applied is usually 25 to 60 ° C.,
30-50 degreeC is preferable. It is preferable to cool the coating solution once to increase the viscosity of the coating solution after coating on the support or to gel the solution, and then dry with warm air. It is preferable that the film surface temperature after coating is 20 ° C. or lower, preferably 5 to 15 ° C. Drying after cooling is preferably performed by blowing warm air at 20 to 60 ° C. to obtain a uniform film surface. The wet film thickness at the time of application varies depending on the target dry film thickness, but is generally 50 to 300 μm, preferably 70 to 25 μm.
The 0 μm coating speed is largely 20 to 200 m / min, and the drying time is generally 2 to 10 minutes, although it depends largely on the drying ability. The method for coating the above-mentioned void layer on the support can be appropriately selected from known methods. As a coating method, a roll coating method, a rod bar coating method, an air knife coating method, a spray coating method, a curtain coating method or US Pat.
An extrusion coating method using a hopper described in Japanese Patent No. 294 is preferably used.

In the ink jet recording method, various conventionally known methods can be used as the recording method. For details, see, for example, the trend of ink jet recording technology (edited by Koichi Nakamura, March 31, 1995, Nihon Kagaku). Information Co., Ltd.).

[0066]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. The evaluation method used in the examples will be described in detail below.

(Glass transition temperature) 10 mg of film
Differential scanning calorimeter (DSC120 manufactured by Seiko Instruments Inc.)
20 minutes per minute in a nitrogen stream of 100 cm ³ per minute.
The glass transition temperature (Tg) was detected by raising the temperature at a temperature rising rate of ° C. Tg was an average value of the temperature at which the baseline began to become eccentric and the temperature at which the baseline newly returned.

(Rising curl) The height of the four corners that rises due to the curl when the recorded film cut into 4 pieces is conditioned at 23 ° C. and 55% RH and spread on a flat surface with the recording surface facing up. Is expressed in mm. If it does not stand up, the same measurement is performed with the recording surface facing down, and the sign of the obtained value is-(minus). If the recording surface does not rise even if the recording surface faces down, the rising curl amount is set to 0.

(Amount of Warp) When the recorded film cut into four pieces is conditioned at 23 ° C. and 55% RH and held by the upper side of the film and suspended vertically, the amount of movement of the lower side in the horizontal direction Desired. The amount of warpage is expressed in cm of the moving amount, where the moving amount in the direction of the recording surface is positive and the moving amount in the direction opposite to the recording surface is negative. If the flatness is good and it hangs straight, the warpage amount is set to 0.

(Schaukasten suitability) This refers to the adhesiveness of a film on a Schaukasten when a recorded sample is inserted into a vertical type Schaukasten.

Example 1 (Preparation of Biaxially Stretched Film) Dimethyl terephthalate 10
0.05 parts by mass of magnesium acetate hydrate as an ester exchange catalyst was added to 0 parts by mass and 65 parts by mass of ethylene glycol, and transesterification was carried out according to a conventional method. 0.05 parts by mass of antimony trioxide and 0.03 parts by mass of trimethyl phosphate were added to the obtained product. Then
The temperature was gradually raised and the pressure was reduced, and polymerization was carried out at 280 ° C. and 67 Pa to obtain a polyethylene terephthalate (PET) resin having an intrinsic viscosity of 0.65.

150 pieces of pelletized PET resin
After vacuum drying at ℃ for 8 hours, 140
At 0 ° C., a blue dye, Macrolex Blue RR (manufactured by Bayer), was added so that the blue density after stretching was 0.17. Sprinkle with a rotary mixer and melt-mix and color with an extruder. At 285 ° C, melt-extrude in layers from a T-die at 30 ° C.
While being electrostatically applied on the cooling drum of No. 3, they were brought into close contact with each other and cooled to solidify to obtain an unstretched film. This unstretched sheet was stretched 3.3 times in the longitudinal direction at 80 ° C. using a roll type longitudinal stretching machine. The obtained uniaxially stretched film was subjected to a total transverse stretching ratio of 50 at 90 ° C. in the first stretching zone using a tenter transverse stretching machine.
%, And further stretched in the second stretching zone at 100 ° C. so that the total transverse stretching ratio was 3.3 times. Then 2 at 70 ° C
Pre-heat treatment for 5 seconds, and then the first fixing zone at 150 ° C for 5 seconds
Heat setting was performed for 2 seconds, and heat setting was performed for 15 seconds at the second fixing zone 220 ° C. Cool to room temperature over 60 seconds, thickness 175μm
A biaxially stretched film of was obtained. The glass transition point Tg of the obtained biaxially stretched film was 81 ° C.

(Preparation of Heat Treated Film) From the biaxially stretched film obtained here, a width of 1500 mm and a length of 200
A 0 m film was sampled and wound on a core (material: phenol resin) having a diameter of 210 mm. In this state,
The entire roll was heated to 70 ° C. for 24 hours, held for 80 hours, and then heated for 24 hours to room temperature to obtain a heat-treated film having a thickness of 175 μm.

(Preparation of film with undercoating) Corona discharge treatment of 8 W / m ² · min was applied to both sides of the above heat-treated film, and coating solution a-1 was applied to both sides to give a dry film thickness of 0.2 μm. It was provided and dried to provide an undercoat layer A-1. Further, both surfaces of the undercoat layer A-1 were subjected to corona discharge of 8 W / m ² · min, the coating solution a-2 was applied so as to have a dry film thickness of 0.03 μm, and dried to obtain the undercoat layer A-2. Was set up. Then, the support was heat-treated at 140 ° C. for 2 minutes to obtain an undercoated film.

[0075]   << Subbing coating solution a-1 >> n-Butyl acrylate (10% by mass) t-Butyl acrylate (35% by mass) Styrene (27 mass%) 2-hydroxyethyl acrylate (28% by mass)                 Copolymer latex liquid (solid content 30%) 70 g Compound (A) 0.1 g Hexamethylene-1,6-bis (ethylene urea) 0.4g Make up to 1 liter with water.

[0076]   << Subbing coating liquid a-2 >> Compound (A) 0.2 g 3.1 g of compound (B) Compound (C) 0.3 g Silica matting agent (particle size 2-3 μm) 3.0 g Make up to 1 liter with water.

[0077]

[Chemical 9]

180 g of fine particle silica having an average primary particle size of 12 nm synthesized by a gas phase method was added to 1000 ml of pure water and dispersed by a high speed homogenizer to obtain a pale transparent dispersion. Next, in this silica aqueous dispersion, 25 of the exemplified cationic polymer Mor-1 is used as the cationic polymer.
% Aqueous solution (100 ml), and 0.01% of antifoaming agent DF-1 (polypropyleneoxy-polyethyleneoxy-disuccinate) was added to the coating solution and dispersed by a high-speed homogenizer for 30 minutes to give a pale white transparent solution. A dispersion was obtained. Next, the average degree of polymerization is 300, and the saponification degree is 98%.
1 ml of polyvinyl alcohol aqueous solution was added, and further, 600 m of 5% polyvinyl alcohol aqueous solution (containing 4% by mass of ethyl acetate) having an average degree of polymerization of 3500 and a saponification degree of 95%.
1 was gradually added, then 100 ml of a 4% borax aqueous solution was added as a viscosity improver, and further 20 ml of ethanol was added. To this, 30 ml of the following dispersion 1 was added,
An ink receiving layer liquid that forms a layer having voids was prepared.

(Dispersion 1) Solutions 1 and 2 having the following compositions were prepared, mixed and dispersed by an ultrasonic disperser. Solution 1 Di-i-decyl phthalate 3.0 g Ethyl acetate 5 ml Solution 2 Gelatin 1.0 g Surfactant (Maruzen Pharmaceutical Co., Ltd. QC-100) 2.8 g Pure water 22 ml Ink receiving layer obtained as described above The liquid was applied to the outer surface of the roll when heat-treated so that the wet film thickness was 240 μm, and the applied film temperature was cooled to 15 ° C. or lower, and then 40 ° C.
Sample 1 was prepared by drying with warm air for 150 seconds.

Example 2 Except that the heat treatment was carried out so that the ink receiving layer was not wound after the ink receiving layer was coated.
An undercoat layer and an ink receiving layer were applied in the same manner as in Example 1 to prepare Sample 2.

[Comparative Example 1] An undercoat layer and an ink receiving layer were coated on the outer surface of the film in the same manner as in Example 1 without heat-treating the biaxially stretched film to prepare Sample 3.

[Comparative Example 2] A subbing layer and an ink receiving layer were coated in the same manner as in Example 1 except that the coated surface of the ink receiving layer was changed to the inner surface of the roll when heat-treated, to prepare Sample 4. did.

[Comparative Example 3] Except that the heat treatment was carried out in the roll after the ink receiving layer was coated.
An undercoat layer and an ink receiving layer were applied in the same manner as in Example 1 to prepare Sample 5.

[Comparative Example 4] A sample 6 was prepared by coating the undercoat layer and the ink receiving layer on the winding inner surface of the film in the same manner as in Example 1 without heat-treating the biaxially stretched film.

Samples 1 to 6 produced as described above were cut into 4 pieces, and medical diagnostic image data was printed using a piezo type ink jet printer to obtain a recorded film. The evaluation of these recorded films is summarized in Table 1.

[0086]

[Table 1]

[0087]

EFFECT OF THE INVENTION Curling is reduced by subjecting an ink jet recording film having an ink receiving layer or a support to heat treatment, and handling property, that is, flatness on a Schaukasten, which is a problem when used for medical purposes, is imparted. The ink jet recording film and the medical image forming method using the same can be provided.

Claims (7)

[Claims] 1. A transparent support having an outer diameter of 100 mm or more and 100 or more.
1 minute-at a temperature from the glass transition point Tg (° C) to Tg-40 (° C) of the support in a state of being wound around a winding core of 0 mm or less.
A method for producing a support for inkjet recording, which comprises heat treatment for 1500 hours. 2. A method for producing an ink jet recording film, which comprises coating an ink receiving layer on the outer winding surface of the ink jet recording support obtained by the production method according to claim 1. 3. The ink receiving layer of the ink jet recording film produced by the production method according to claim 2, contains silica fine particles having an average primary particle diameter of 5 to 100 nm and a water-soluble resin, and the fine particles are contained. And a water-soluble resin in a mass ratio in the range of 3: 1 to 10: 1. 4. An ink jet recording film, 23
Hold the upper edge of the recorded film in an atmosphere of 55 ° C RH, and the amount of warp when hanging is +0.5 cm to -5 cm.
The film for inkjet recording according to claim 3, wherein 5. An ink jet recording film, 23.
The rising curl when a recorded film is placed on a flat surface in an atmosphere of 55 ° C RH +3 mm to -10 m
The film for inkjet recording according to claim 3 or 4, wherein m is m. 6. The inkjet recording film according to claim 3, which is a medical image recording film. 7. A medical image forming method using the ink jet recording film according to claim 6.