JPH11192775A - Method for ink jet recording and recorded material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance an image density and to improve a resolution by forming at least a porous polymer resin layer on a base material and regulating a superposition of a fine pore size distribution of the resin layer and a particle size distribution of a pigment component. SOLUTION: In the method for ink jet recording for recording a recording medium having at least one porous polymer resin layer 104 on a base material 101 by using an ink containing at least a pigment component, when a fine pore size distribution of a porous polymer resin layer 104 and a particle size distribution of a pigment component are set to predetermined frequency distributions, an image is formed in such a manner that a ratio of frequency of a fine pore size of the layer 104 to be superposed with the particle size distribution of the pigment component to that of the overall fine pore size of the layer 104 is set to 0.1 to 10%. After the image is formed, the layer 104 is heat treated. In a recorded material thus obtained, an ink pigment component 200 is fixed near a surface of the layer 102, and an ink dye component 200 is fixed on the material 101.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method suitable for forming an image using an ink containing a pigment component.

[0002]

2. Description of the Related Art Ink jet recording is a method in which fine droplets of ink are caused to fly according to various operating principles and adhere to a recording medium such as paper to record images, characters, and the like. It has features such as easy multi-coloring, great flexibility in recording patterns, and no need for development and fixing. For this reason, as a recording method of a recording device for various images, it is rapidly spreading in various uses including information devices. Furthermore, images formed by the multi-color ink jet method can obtain multicolor printing by the plate-making method or a record comparable to printing by the color photographic method. Since it can be manufactured at lower cost than by multicolor printing or printing, it is being widely applied to the field of full-color image recording. Faster recording,
Recording devices and recording methods have been improved with the demand for improved recording characteristics such as higher definition and full color.However, advanced characteristics have also been required for recording media. Various recording media that can be used for various purposes, inks, and the like have been improved.

In the ink jet recording method, ink droplets are ejected from a nozzle toward a recording medium at a high speed. Since the ink contains a large amount of a solvent such as water or a mixture of water and an organic solvent, the ink jet recording method is very expensive. In order to obtain color density, it is necessary to use a large amount of ink. In addition, since the ink droplets are continuously ejected, when the first droplet is ejected, a beading phenomenon occurs in which the ink droplets are fused and the ink dots are joined, and the image is disturbed. For this reason, the ink jet recording medium is required to have both a large ink absorption amount and a high ink absorption speed.

For this reason, as disclosed in Japanese Patent Application Laid-Open No. Hei 2-276670, a porous layer made of inorganic particles such as a porous layer made of alumina hydrate is provided on a base material in order to enhance absorption, color development and resolution. Many recording media by formation have been proposed. Japanese Patent Application Laid-Open No. 4-101880 proposes a recording medium in which a resin in which an ink fixing layer is transparent and which is dissolved or swelled by a solvent contained in the ink is formed on a substrate.

[0005] In the ink jet recording system, a type of ink in which a dye component is dissolved in a solvent has hitherto been often used. However, when a dye ink is used, it is inherently inferior in light resistance and ozone resistance, and therefore, there is a problem that the printed matter is faded or discolored when stored for a long period of time. For this reason, a porous layer made of a thermoplastic polymer material is provided on a substrate as described in JP-A-58-136482 and U.S. Pat. No. 5,374,475, and after printing, the porous layer is formed by the action of heat and pressure. There has been proposed a recording medium in which the material is dissolved to make it dense.

Further, as in Japanese Patent Publication No. 2-3673,
A recording medium having a two-layered ink receiving layer in which an inorganic pigment layer having a large ink absorption amount is formed on a base material and an ink receiving layer made of a thermoplastic organic polymer is provided on the outermost layer has been proposed.

On the other hand, recently, instead of dye ink,
In order to solve the problems of light fastness, water fastness, and ozone fastness, and to obtain a high-density image, a pigment ink has been widely used and has been applied to an ink jet recording system.

In the case where a pigment ink is used, there is a problem in that the pigment is insoluble in a solvent, and when exposed to the surface of a medium, it has poor abrasion resistance and poor water resistance. A mechanism is needed. A method is known in which a polymer fixing agent is contained in the pigment ink in addition to the pigment component, and the polymer fixes the pigment when the ink lands.
In order to obtain high fixability, there is also an improvement. Further, a recording liquid using both a pigment and a dye is known from the viewpoint of obtaining a high-density image.

As media for pigment ink, Japanese Patent Application Laid-Open Nos. 8-230308, 9-30116, 9-66660, and 9-123593 have been proposed.

[0010]

However, according to the above prior art, there are the following problems.
That is, there is a remarkable difference in the size of the particles and molecules of the pigment and the dye in the ink, so there is a large difference in the fixing and adsorption mechanisms, and the recording medium used for the dye ink is different from the pigment ink. Is not always applicable.

For example, when printing on a medium described in Japanese Patent Application Laid-Open No. 2-276670, as shown in FIG.
2. There is a portion that is deposited and exposed on the surface, and sufficient abrasion resistance and water resistance cannot be obtained. Further, Japanese Patent Application Laid-Open No.
When printing on the recording medium described in No. 0, the state in which the viscosity or the strength of the resin member is reduced due to the dissolution or swelling of the resin member by the ink solvent continues, and the absorption speed is low, so that stickiness or peeling due to contact occurs. Also, the image color density is insufficient. When printing on a recording medium described in JP-A-58-136482 and US Pat. No. 5,374,475,
As the coloring material passes through the microporous structure together with the pigment component and the dye component, it is taken into the microporous layer.
As shown in (2), since the pigment component 200 having a large particle size is half-dispersed in the pores of the resin layer 402, the image density cannot be increased even if the ink amount is increased.

In Japanese Patent Publication No. 2-31673, a sufficient ink absorption amount can be obtained.
Similarly, it is not considered to be applicable to pigment inks. That is, since the correlation between the size of the pores of the pigment and the resin layer has not been optimized, the pigment component in the pigment ink is dispersed and arranged in the pores of the resin layer on the inorganic pigment layer. However, even if the ink amount is increased, the image density cannot be increased.

Further, there are some problems in the medium corresponding to the pigment ink described above.

In the above-mentioned JP-A-8-230308, a porous undercoat layer having a submicron order pore size is provided on a substrate, and an overcoat layer containing plastic beads and having micron order pores is provided thereon. Therefore, the pigment that constitutes the image is trapped in the micron-order holes of the overcoat layer, but the trapped pigment is dispersed and enters the overcoat layer in the vertical direction. It is difficult to achieve the concentration. Further, since the pigment only enters the pores of the overcoat layer and is not fixed and fixed, there has been a problem that long-term reliability is lacking when the recorded matter is stored.

In Japanese Patent Application Laid-Open No. 9-30116, as shown in FIG. 11, a surface layer 603 having pores through which a pigment 200 passes and an ink holding layer 602 are provided on a light-transmitting substrate 601. The volume and the pH of the surface layer are adjusted, pigment ink is printed from the surface layer 603 side, and an image is observed from the translucent base material 601 side. When characters are printed, mirror characters are printed. There is a problem that the apparatus and the image preprocessing must be performed. Further, since the surface layer 603 has pores large enough to allow the pigment to pass through, the transparency of the surface layer 603 was reduced, and the surface layer 603 was not suitable for a transmission type recording medium such as OHP.

In Japanese Patent Application Laid-Open No. 9-66660, a lower alumina hydrate porous layer is provided on a base material, and a porous layer having an average pore diameter smaller than that of the lower alumina hydrate porous layer is provided thereon. Although the upper layer adjusts the ink absorption speed and uniformly disperses and absorbs the pigment ink, the absorption of the upper porous layer is slow, so that problems such as bleeding occur when printing a large amount of ink. Was.

In JP-A-9-123593, 1
A porous layer of alumina hydrate having a thickness of about 200 μm is provided, and a water-soluble resin layer having a thickness of 0.01 to 50 μm is provided thereon to absorb and swell the solvent in the ink and appropriately control the drying speed. However, there are problems such as a long time from swelling to drying and bleeding when printing a large amount of ink.

In consideration of the above problems, the present invention provides an ink-jet recording method which can uniformly fix a pigment and obtain a high image density even when a pigment ink containing a pigment component as a coloring material, and this ink-jet recording method. It is an object to provide a recorded matter obtained by a recording method.

[0019]

According to the ink jet recording method of the present invention, recording is carried out on a recording medium having at least one layer of a porous polymer resin formed on a substrate, using an ink containing at least a pigment component. In the inkjet recording method, when the pore diameter distribution of the porous polymer resin layer and the particle size distribution of the pigment component are each a frequency distribution,
The ratio of the frequency of the pore diameter of the porous polymer resin layer overlapping the particle size distribution of the pigment component to the frequency of the entire pore diameter of the porous polymer resin layer is set to 0.1% to 10%. An image is formed, and after the image is formed, the porous polymer resin layer is subjected to a heat treatment.

The recorded matter of the present invention has at least one polymer resin layer on a base material, and the pigment component of the ink is fixed near the surface of the polymer resin layer. The dye component of the ink is fixed.

The present invention resides in an ink jet recording method in which when printing an ink containing a pigment component as a main component of a coloring material, the pigment is fixed uniformly and a high image density is obtained. Furthermore, it is excellent in water resistance, light resistance, can be stored for a long period of time, and even when using an ink having a relatively high pigment concentration, it can obtain abrasion resistance, so that the effect of increasing the pigment concentration of the ink can be achieved. It is in the recorded matter that has been demonstrated and has achieved high image density and excellent color tone. The present invention has been completed by studying the findings obtained by the inventors' experiments in further detail.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to preferred embodiments.

FIGS. 1 and 2 show an example of the recorded matter of the present invention. In FIG. 1, 101 is a substrate, 102 is a polymer resin layer in which a porous polymer resin layer is formed by heating, 200 is a fixed pigment component, and 201 is a fixed dye component.
FIG. 2 shows a structure in which a porous inorganic pigment layer 103 is provided between a base material 101 and a polymer resin layer 102.
0 is fixed near the surface of the resin layer 102 and the dye component 201
Are fixed on the porous inorganic pigment layer 103.

In the present invention, since the pigment components 200 of the ink are uniformly arranged and fixed in the vicinity of the surface of the polymer resin layer 102, even when printing over a wide range such as solid printing, light from the image Is prevented as much as possible, and a recorded matter on which an image having a high image density is formed can be obtained. Further, since the polymer resin layer 102 is transparent, a recorded matter which can be used for an OHP or the like utilizing light transmission can be obtained. Here, the transparent polymer resin layer has a light transmittance of at least 50% or more, and preferably 85% or more. Further, since the dye component is fixed on the base material 101 or in the porous inorganic pigment layer 103, the image density is further increased, and an excellent color tone is obtained. , It is possible to prevent fading and discoloration peculiar to the dye component. Here, since the polymer resin layer 102 is formed by densifying the porous polymer resin layer by a heat treatment, the resin melted in the pigment components uniformly arranged at the same time as the densification is performed. After permeation and cooling, the resin and the pigment component are integrated and a strong bond is obtained, and a recorded matter having high scratch resistance and high water resistance is obtained.

Here, the recording medium for obtaining the recorded matter as shown in FIGS. 1 and 2 is that shown in FIGS. 3 and 4.
And 104 in FIG. 4 denotes a porous polymer resin layer which becomes a polymer resin layer by heating.

FIG. 5 is a schematic view of the porous polymer resin layer as viewed from the ink landing surface. Here, the porous polymer resin layer has a porous matrix structure formed therein, and gaps in the porous matrix structure correspond to pores. In the figure, reference numeral 901 denotes polymer resin particles, 902 denotes pores, and 200 denotes a landed pigment component.

In the present invention, when ink is landed on the porous polymer resin layer, the relationship between the pore diameter of the porous polymer resin layer and the particle size of the pigment component in the ink is optimized. , The solvent in the ink passes through the pores 902,
The pigment component is absorbed in the porous polymer resin layer, and the pigment component 200 does not pass through the pores and is adsorbed and arranged near the surface of the porous polymer resin layer. That is, the porous polymer resin layer 104 functions as a layer through which the solvent component in the ink passes, and further functions as a pigment component holding layer for fixing the pigment component. That is, it functions as a “filter” that allows the water (solvent) in the ink to pass but does not allow the pigment component to pass. At this time, the relationship between the pore diameter of the porous polymer resin layer and the particle size of the pigment component was as shown in FIG. 6, where the particle size distribution of the pigment component and the pore diameter distribution of the porous polymer resin layer were respectively shown. By controlling the degree of overlap as a frequency distribution, the role of a "filter" is realized. That is, even in the case of a distribution in which the pigment component having a relatively small particle size in the particle size distribution is contained in the ink, the frequency of the pore diameter of the porous polymer resin layer overlapping the particle size distribution of the pigment component (part A) Frequency),
0.1% of the frequency of the entire pore diameter of the porous polymer resin layer.
When the content is 1% to 10%, the effect of the arrangement of the pigment components and the effect of the filter for passing the solvent can be obtained. If it is less than 0.1%, the passage of the solvent in the ink is hindered, and if it is 10% or more, the effect of uniform arrangement is reduced. Further, it is more preferable that the degree of overlap is 5% or less.

Here, the pore diameter of the porous polymer resin layer is preferably in the range of 10 to 300 nm. 10n
If it is smaller than m, the absorption rate cannot be increased,
When pores larger than 300 nm are present, the overlap with the particle diameter of the pigment component in the ink increases, and the effect of uniformly arranging the pigment component decreases.

The pores of the porous polymer resin layer may have the surface layer and the middle layer, and the lower layer and the pore diameter may be inclined and distributed, and particularly, the depth within 5 μm from the surface of the porous polymer resin layer. By setting the pore diameter to 100 nm or less in the direction range, the effect of uniform arrangement of the pigment component near the surface of the porous polymer layer is further enhanced. Further, the image density can be further increased by limiting the pigment component to a portion within 1 μm. The pore size distribution was measured by drying a recording medium having a porous polymer resin layer formed on a PET film in a vacuum state for at least 24 hours and then applying a mercury intrusion method (for example, EW WASHIBURN, Proc. Natl.Acad.Sc
i. 7, p. 115 (1921) etc.). The pore size was calculated by using Barrett.
These methods are used (J. Am. Chem. Soc. 73.373).
(1951)).

On the other hand, the particle diameter of the pigment component herein means substantially the diameter of the aggregate of primary particles. Generally, the particle size distribution of the pigment component used in the ink jet is 3
In the range of 0 to 500 nm, and more preferably,
It is in the range of 60 to 200 nm. Here, the particle size of the pigment particles is measured using a centrifugal sedimentation method.

The pores of the porous polymer resin layer as described above depend on the type of polymer resin particles used, the particle size, drying conditions,
It is obtained by optimizing the relationship such as the film thickness.

Here, in order to form the porous polymer resin layer, thermoplastic resin particles are used. These resin particles are used as an aqueous or non-aqueous dispersion or suspension, and are used as a colloidal solution in a solvent or water. Exist and used.

Examples of such resin particles include polyester, polyethylene, polyurethane, styrene-acrylic copolymer, polyacrylate, polymethacrylate, ethylene-vinyl acetate copolymer, polystyrene, polyvinyl chloride and the like. No. However, it is not limited to these resins, and those obtained by modifying these resins and those obtained by copolymerizing monomers can also be used. These resin particles are used alone or in combination as desired.

The shape of the resin particles may be spherical or needle-like. However, in order to form a porous polymer resin layer having more uniform pores, a shape close to a true sphere is preferable.

The resin particles have an average particle size of 0.1 μm to 5.0.
μm is preferred. If the average particle diameter of the resin particles is less than 0.1 μm, a porous polymer resin layer having good ink absorbency and permeability is formed because pores having a pore diameter of 10 nm or more cannot be obtained. Because of this, the ink overflows and bleeds. When the average particle diameter of the resin particles exceeds 5.0 μm, the pore diameter is 300 nm.
The pigment component in the ink is partially or more diffused into the porous polymer resin layer, and the pigment component is dispersed near the surface of the porous polymer resin layer. And cannot be arranged and distributed near the surface layer. For this reason, since the image is scattered with the pigment, the image has a dull color density. The preferred average particle size of the resin particles is from 0.2 μm to 3.0 μm.

The minimum film forming temperature of the resin particles is 40 ° C. to 150 ° C.
It is preferably in the range of ° C. Here, the minimum film forming temperature is a minimum temperature at which the resin particles can be formed as a uniform film when formed and heated as a coating film. In the present invention, after the resin particles are uniformly applied, the porous polymer resin layer is not formed into a dense film in order to form a porous polymer resin layer. It is necessary to heat and dry under conditions such that a porous matrix structure is formed. The porous matrix structure referred to here is different from a structure in which the inorganic particles themselves have pores like a porous inorganic pigment layer and absorb using the pores. A matrix structure is obtained by partial bonding by heat, and ink absorption is performed using other gaps. Therefore, when the minimum film-forming temperature is lower than 40 ° C., when coating and drying the resin particles, a dense film tends to be formed, and the porous property is lost. For this reason, not only the pigment component in the ink but also the permeation of moisture is impeded, and the ink overflows during printing, causing bleeding. Although it is possible to lower the drying temperature in order not to form a dense film, the solvent in the applied dispersion or colloidal solution becomes difficult to dry, and the drying time becomes longer. If the minimum film forming temperature exceeds 150 ° C., it is necessary to increase the heat treatment after image formation, and the pigments and dyes in the base material, the porous inorganic pigment layer, and the ink are decomposed, oxidized, and colored. Problems arise. A more preferred minimum film forming temperature is 50 ° C to 130 ° C.

The thickness of the porous polymer resin layer is 1 μm to 40 μm.
μm is preferred. When the thickness is less than 1 μm, it does not function as an ink absorbing layer when a film is formed,
In addition, the function of fixing the pigment component is reduced. That is,
In the present invention, the reason why the pigment component of the ink can be fixed is as follows. First, when the ink is printed, the ink is uniformly arranged near the surface of the porous polymer resin layer. As the amount of ink to be printed is increased and the concentration of the pigment component is increased, after the ink lands, the pigment component itself overlaps on the surface of the porous polymer resin layer to form a dense layer and form a uniform arrangement. But have not joined at this time. Naturally, if the printed portion is rubbed as it is, the arranged pigment components are peeled off. However, in the present invention, by heating after printing, the resin particles forming the porous polymer resin layer around the uniformly arranged pigment component are melted and combined with the pigment component. At this time, if the thickness of the porous polymer resin layer is not sufficient, the resin particles cannot be completely bonded to the pigment component, and an unfixed pigment component is present. Here, the viscosity of the resin particles is reduced by heating in the gaps between the arranged pigment components, and the resin particles permeate in a molten state and serve as an adhesive between the pigment components. Here, by setting the thickness of the porous polymer resin layer to a sufficient thickness, the molten resin component can sufficiently penetrate into the gap between the pigment components, and can further sufficiently cover the surface of the pigment component of the ink. In the case of an ink containing a dye component, if the thickness is too small, the effects such as light resistance and ozone resistance are reduced. Conversely, if the thickness is too large, cracks or the like may occur during drying, resulting in a decrease in strength or a loss of uniformity of the coating film. Therefore, the transparency and the sharpness of the image are also reduced. A more preferred thickness of the porous polymer resin layer is 3 μm to 30 μm.

The heat treatment for densifying the porous polymer resin layer is carried out in a generally used hot air drying oven, infrared drying oven, hot plate or the like alone or in combination. Heating may be performed from the front or back surface of the recorded matter, or from both surfaces. Further, a pressure treatment may be used in combination with the heat treatment. At this time, since the melting by the heat treatment is promoted by the pressure treatment, the densification of the resin is promoted, and the treatment can be performed in a shorter time. Specifically, the heat treatment is completed by passing through a roll-shaped heat roll used for lamination or the like, and then passing through a cooling roll. At this time, if the surface of the roll is made a mirror surface, a smoother surface can be obtained, and if the surface of the roll has a shape, a mat-like surface can be obtained.

The solid content concentration of the polymer resin particles is not particularly limited, but 5 to 50% by weight of resin particles can be appropriately used. Incidentally, a small amount of a polymer component acting as a binder may be added to the polymer resin particles.

The method of applying the polymer resin particles is not particularly limited, and it can be performed by a roll coater, an air knife coater, a blade coater, a bar coater, a gravure coater, a rod coater or the like. Drying is performed by a commonly used hot air drying oven, infrared drying oven, or the like, alone or in combination, at a temperature lower than the minimum film forming temperature of the polymer resin particles.

The substrate 101 is not particularly limited, and various substrates can be used. Papers such as appropriately sized paper, non-sized paper, resin-coated paper, resin films and sheets, fabrics, glass and metal can be used. Transparent films and sheets of polyester, polystyrene, polyvinyl chloride, polymethyl methacrylate, cellulose acetate, polyethylene, polycarbonate, etc., or hydrated alumina, hydrated titanium white, etc., or foamed resin Films and sheets can be used. When a transparent film is used as a substrate, it can be used for medical images such as OHP (overhead projector) sheets and X-ray films. When using an opaque plastic film containing white pigment or paper as the base material,
It can also be used in the field of photo-like photo images. Further, the color tone of the whole image can be adjusted by making the base material contain various kinds of color pigments or the like so as to be translucent or colored.

The surface of the substrate may be subjected to a surface treatment such as a corona treatment or the like, or an easy-adhesion layer may be provided as a subbing layer in order to improve the adhesion to the ink receiving layer. Further, an anti-curl layer such as a resin layer or a pigment layer may be provided on the back surface or a predetermined portion of the substrate for curl prevention.

The thickness of the substrate is not particularly limited, either.
Those having a size of 5 μm to 500 μm are preferred. The thickness of the substrate is appropriately selected depending on the purpose.

Further, as a recording medium capable of realizing high image density and high gradation, as shown in FIGS. 2 and 4, a porous inorganic pigment layer 103 and a porous polymer resin are provided on a substrate 101. A recording medium in which the layers 104 are sequentially formed is conceivable. In the present invention, when the recording medium of FIG. 4 is used, the porous polymer resin layer 104 and the porous inorganic pigment layer 10
Since the relationship between the absorption amount and the absorption speed of No. 3 is optimized, high absorption capacity can be obtained. That is, printing by a printer having a large amount of ink becomes possible. Therefore, an image with high image density and high gradation can be obtained. That is, by making the absorption amount of the porous inorganic pigment layer 103 located in the lower layer larger than the absorption amount of the porous polymer resin layer 103 located in the upper layer, most of the solvent is absorbed by the porous inorganic pigment layer 103. Therefore, the porous polymer resin layer 104
The solvent is prevented from overflowing in the lateral direction. In this way, by adjusting the ink absorption balance of the entire layer, the dot diameter of the landed ink can be optimized, and the high image density obtained by the pigment component can be secured without being hindered. Further, by making the absorption rate of the porous polymer resin layer 104 located on the upper layer higher than the absorption rate of the porous inorganic pigment layer 103 located on the lower layer, the solvent of the ink that has landed immediately after ink printing is received by the lower layer. Because it can be passed, the possibility of bleeding on the surface can be further reduced,
An image with higher resolution can be formed.

Here, the porous inorganic pigment layer 103 functions as an absorbing layer for the solvent component in the ink and, in the case of an ink containing a dye component, as a fixing layer for the dye component, and absorbs the ink in the entire ink absorbing layer of the sheet. In particular, it is desired that the ink absorption amount is large.

In order to ensure a sufficient amount of absorption, it is necessary to adjust the pore diameter of the porous inorganic pigment layer. At this time, the average pore diameter is preferably 20 nm or less, and it is desirable that pores exceeding 20 nm are not substantially present. When the pore diameter exceeds 20 nm, light scattering is caused, transparency is impaired, and an image formed when printed is undesirably whitish. The pore size distribution is measured by a nitrogen adsorption / desorption method.

Further, in order to adjust the absorption amount, the total pore volume of the porous inorganic pigment layer is desirably in the range of 0.1 to 1.0 cc / g. A more preferred range is 0.4 to 0.6 cc / g.
It is. When the pore volume of the porous inorganic pigment layer is larger than the above range, cracks and powder fall occur when the porous inorganic pigment layer is formed, and when the pore volume is smaller than the above range, ink absorption is poor. Further, the pore volume per area unit of the porous inorganic pigment layer is desirably 8 cc / m ² or more. Below the above range, the ink absorption capacity of the porous inorganic pigment layer is insufficient particularly when multicolor printing is performed, and the ink overflows to cause bleeding in the image. The BET specific surface area of the porous inorganic pigment layer is preferably in the range of ²⁰ to 450 m2 / g. If the BET specific surface area is too small, the haze increases, so that the image has a white haze. Conversely, BET
If the specific surface area is too large, cracks tend to occur.

It is desirable that the porous inorganic pigment layer is formed on a substrate as a layer in which inorganic pigment particles are bound with a binder. The inorganic pigment particles are preferably in the form of porous particles, and the particle diameter is preferably from 20 to 500.
nm is preferred. For example, when a particle having a particle size smaller than this range is used, cracks may easily occur, and when a particle having a particle size larger than this range is used, haze may be caused by light scattering. And the image may become whitish overall. Specifically, calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titania, zinc oxide, zinc carbonate, aluminum silicate, alumina hydrate, silicic acid, sodium silicate, magnesium silicate, calcium silicate, Silica and the like can be used, and these can be used alone or in combination.

Particularly preferred pigments from the viewpoint of image aptitude such as ink absorbency and resolution are silica and alumina hydrate. As the silica, a natural silica, a synthetic silica, an amorphous silica, or a chemically modified silica-based compound can be used. Particularly, a silica having a positive charge is preferably used.

Alumina hydrate has a positive charge, so that the dye in the ink is fixed well, an image with high gloss and good color development can be obtained, and the alumina hydrate has a lower level than the ink receiving layer using other pigments. Haze increases transparency and is more preferable as a pigment used in a porous inorganic pigment layer.

The alumina hydrate used in the present invention is represented by the following general formula.

Al2O3-n (OH) 2n.mH2O In the formula, n represents any one of the integers 0, 1, 2 and 3, and m represents a value of 0 to 10, preferably 0 to 5. Represent. m
Since H2 O often represents a detachable aqueous phase that does not participate in the formation of a crystal lattice, m can take a non-integer value. Also, when this type of alumina hydrate is calcined, m can reach a value of zero.

Alumina hydrates suitable for the practice of the present invention include, for example, Japanese Patent Application Nos. 5-125439 and 5-125.
No. 438, No. 5-125439, No. 6-114571
It is preferable to use the alumina hydrate described in the above item.

The pore properties of the alumina hydrate are adjusted during the production process. However, in order to satisfy the BET specific surface area and the pore volume of the porous inorganic pigment layer, the pore volume is 0.1%. It is preferable to use alumina hydrate having a concentration of １．０1.0 ml / g. When the pore volume of the alumina hydrate is out of the above range, it becomes difficult to make the pore volume of the porous inorganic pigment layer fall within the above specified range.

The BET specific surface area is 40 to 500.
It is preferable to use an alumina hydrate having a m2 / g. When the BET specific surface area of the alumina hydrate is out of the above range, it is difficult to make the specific surface area of the porous inorganic pigment layer within the above specified range.

As the binder used in combination with the above pigment, a water-soluble and water-dispersible polymer substance is preferable.
For example, polyvinyl alcohol or a modified product thereof (cation modified, anionic modified, silanol modified), starch or a modified product thereof (oxidation, etherification), gelatin or a modified product thereof, casein or a modified product thereof, carboxymethylcellulose, gum arabic, hydroxy Ethyl cellulose, cellulose derivatives such as hydroxypropyl methyl cellulose, SBR latex, NBR latex,
Conjugated diene-based copolymer latex such as methyl methacrylate-butadiene copolymer, functional group-modified polymer latex, vinyl-based copolymer latex such as ethylene-vinyl acetate copolymer, polyvinylpyrrolidone, maleic anhydride or a copolymer thereof And acrylate copolymers are preferred. These binders can be used alone or in combination of two or more.

As long as the BET specific surface area and the pore volume of the porous inorganic pigment layer satisfy the above ranges, the mixing ratio between the pigment and the binder is 1: 1 to 30: 1 by weight, preferably 5: 1. ２０20: 1. When the amount of the binder is less than the above range, the mechanical strength of the porous inorganic pigment layer is insufficient, and cracks and powder fall occur. Gets worse.

A coating liquid is obtained using the above-mentioned inorganic pigment particles and a binder, and by forming a coating film on a substrate,
A porous inorganic pigment layer can be formed.

The pH of the coating solution itself is preferably from 3 to 7.
When a porous inorganic pigment layer is formed using a coating liquid having a pH lower than 3, discoloration of the printed ink may easily occur. When the pH is higher than 7, the coating solution tends to thicken, and the stability over time may decrease.

The coating liquid may further contain a dispersant, a thickener, a pH adjuster, a lubricant, a fluidity modifier, a surfactant, an antifoaming agent, a water-proofing agent as long as the object of the present invention is not impaired. Agents, defoamers,
A release agent, a sunscreen and the like can also be added.

The coating of the coating liquid on the substrate is performed, for example, by a blade coating method, an air knife coating method, a roll coating method, a flash coating method, a gravure coating method, a kiss coating method, a die coating method, an extrusion method, a slide hopper. (Slide bead) method, curtain coat method, spray method and the like.

The coating amount of the coating liquid on the substrate may be appropriately selected depending on the desired use and the like. That is, if the thickness is too thin, the ink cannot be sufficiently absorbed, and bleeding to the upper porous polymer resin layer side occurs, which is not preferable. Conversely, if the thickness is too large, the strength of the porous layer is reduced, or a coating film defect occurs during coating and drying. Further, the transparency is reduced, and the transparency of the recorded matter and the sharpness of the image may be impaired, which is not preferable. Therefore, the preferable thickness of the porous inorganic pigment layer is 5 to 50 μm in order to secure the absorption amount and maintain the strength of the entire film.

The porous inorganic pigment layer can be obtained by subjecting the coating layer provided on the substrate to a drying treatment by heating as necessary. By the drying treatment, the aqueous medium (dispersion medium) evaporates, and a film is formed by bonding or bonding of the alumina hydrate particles and the binder by crosslinking. The conditions for the drying treatment can be appropriately determined according to the composition of the coating solution used. Drying is performed by a commonly used hot air drying oven, infrared drying oven, or the like, alone or in combination.

The pigment ink for inkjet used in the present invention is not particularly limited, but an outline thereof will be described below.

The amount of the pigment component contained in the pigment ink in the present invention is preferably 0.1 to 20% by weight, more preferably 1 to 12% by weight. Although any pigment can be used in the present invention, for example, carbon black used in black ink includes a carbon black manufactured by a furnace method and a channel method, and a particle diameter of primary particles. Is 15 to 40 nm, specific surface area is 50 to 300 square m / g by BET method, DB
The P oil absorption is 40-150 ml / 100 g, and the volatile content is 0.
5 to 10%, pH value from 2 to 9;
o. 2300, no. 900, MCF88, No. 3
3, No. 40, no. 45, no. 52, MA7, M
A8, No. 2200B (Mitsubishi Chemical) RAVEN 12
55 (made in Colombia), REGAL 400R, REGAL 330, REGAL 6
60R, MOGUL L (Cabot), ColorBlack FW1, Colo
r Black FW18, Color Black S170, Color Black S150,
Commercial products such as Printex 35 and Printex U (Degussa) can be used. Pigments used in the yellow ink include CI Pigment Yellow 1 and CI Pigment Yell.
ow 2, CIPigment Yellow 3, CIPigment Yellow 13,
CI Pigment Yellow 16, Pigment Yellow 83, Pigments used as magenta ink include CI Pigment Re
d5, CIPigment Red 7, CIPigment Red 12, CIPig
ment Red 48 (Ca), CIPigment Red 48 (Mn), CIPigmen
t Red 57 (Ca), CIPigment Red 112, CIPigment Red
122, As pigments used as cyan ink, C.I.
I.PigmentBlue1, CIPigment Blue 2, CIPigment B
lue 3, CIPigment Blue 15: 3, CIPigment Blue 16,
CIPigment Blue 22, CIVat Blue 4, CIVat Blue
6 and the like, but are not limited to these.
Further, a product newly manufactured for the present invention can be used.

In order to improve the dispersibility of the pigment, a dispersant is added. Examples of the dispersant include a nonionic surfactant, an anionic surfactant, and a water-soluble resin. When a known type of easily dispersible pigment is used, it may not be added.

Further, in the ink used in the present invention, preferably, the whole ink is adjusted to be neutral or alkaline, so that the solubility of the water-soluble resin is improved, and further, the ink is excellent in long-term storage stability. It is desirable because it can be ink. However, in this case, it is preferable that the pH range is 7 to 10 because it may cause corrosion of various members used in the ink jet recording apparatus.

As described above, the pigment and the water-soluble resin
It is dispersed or dissolved in a liquid medium.

The solvent suitable for the ink used in the present invention is a mixed solvent of water and a water-soluble organic solvent. The water is not general water containing various ions, but is ion-exchanged water such as deionized water. It is preferred to use

Other optional solvent components that can be used in combination include water-soluble organic solvents used by mixing with water, such as methyl alcohol, ethyl alcohol, and the like.
n-propyl alcohol, isopropyl alcohol, n
-Butyl alcohol, sec-butyl alcohol, te
alkyl alcohols having 1 to 4 carbon atoms such as rt-butyl alcohol; amides such as dimethylformamide and dimethylacetamide; ketones or ketone alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyethylene glycol; Polyalkylene glycols such as polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol,
1,2,6-hexanetriol, thiodiglycol,
Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as hexylene glycol and diethylene glycol; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether Lower alkyl ethers of polyhydric alcohols such as N-methyl-2-pyrrolidone,
2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like.

The content of the water-soluble organic solvent in the ink used in the present invention is generally in the range of 3 to 50% by weight of the total weight of the ink, preferably in the range of 3 to 40% by weight. The amount of water used is in the range of 10 to 90% by weight, preferably 30 to 80% by weight of the total weight of the ink.

The method of preparing the ink used in the present invention is as follows. First, a pigment and, if necessary, a dispersant are added to an aqueous solution containing at least a water-soluble organic solvent and water, and the mixture is stirred. , And centrifugation as needed to obtain a desired dispersion. Next, the compound used in the present invention or the components described above are added to the dispersion, and the mixture is stirred to obtain an ink.

Further, it is effective to carry out premixing for 30 minutes or more before dispersing the aqueous solution containing the pigment. This premixing operation improves the wettability of the pigment surface and promotes the adsorption of the resin to the pigment surface when a water-soluble resin is contained.

On the other hand, the disperser used in the present invention may be any commonly used disperser, and examples thereof include a ball mill, a roll mill, and a sand mill. Among them, a high-speed sand mill is preferable, for example, a super mill, a sand grinder, a bead mill,
Agitator mill, Glen mill, Dyno mill, Pearl mill, Kobol mill (all trade names) and the like.

In the present invention, as a method for obtaining a pigment having a desired particle size distribution, the size of the pulverized media of the disperser is reduced, the filling rate of the pulverized media is increased, the processing time is lengthened, and the discharge speed is increased. For example, a method such as slowing down, classifying with a filter after centrifugation, centrifugation or the like is used. Alternatively, a combination of these techniques may be used.

The dyes contained in the ink as required in the present invention include direct dyes, acid dyes, basic dyes, and the like.
Known water-soluble dyes such as reactive dyes and food dyes may be used. I. Direct Black 1
7, 19, 32, 51, 71, 108, 146, C.I.
I. Direct Blue 6, 22, 25, 71, 86, 9
0, 106, 199, C.I. I. Direct Red 1,
4, 17, 28, 83, C.I. I. Direct Yellow 1
Direct dyes such as 2, 24, 26, 86, 98, 142,
C. I. Acid Black 2, 7, 24, 26, 31,
52, 63, 112, 118, C.I. I. Acid Blue 9, 22, 40, 59, 93, 102, 104, 11
3, 117, 120, 167, 229, 234, C.I.
I. Acid Red 1, 6, 32, 37, 51, 52,
80, 85, 87, 92, 94, 115, 180, 25
6, 317, 315, C.I. I. Acid Yellow 11,
Acid dyes such as 17, 23, 25, 29, 42, 61 and 71; I. Basic Black 2, C.I.
I. Basic Blue 1, 3, 5, 7, 9, 24, 2
5, 26, 28, 29, C.I. I. Basic Red 1,
2, 9, 12, 13, 14, 37 and the like can also be used.

The above-mentioned examples of the dye are particularly preferable for the ink applicable to the recording method of the present invention, and the dye for the ink used in the present invention is not limited to these dyes. The content of these dyes in the ink is
0.5 to 4.0% by weight is preferred.

[0078]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

In the following description, what is described as% is based on weight.

Example 1 A transparent PET film having a thickness of 100 μm (100Q manufactured by Toray Industries, Inc.,
80D, transmittance 88.74%), and a coating dispersion was prepared by the following method in order to form the porous inorganic pigment layer 103 on the substrate. First, an aluminum slurry was prepared by hydrolyzing aluminum dodoxide, and water was added to the alumina slurry until the alumina hydrate solid content became 7.9%. Next, a 3.9% nitric acid aqueous solution is added to the mixture to adjust the pH.
After adjustment, a colloidal sol was obtained through an aging step.
The colloidal sol was spray-dried at 75 ° C. to obtain an alumina hydrate. Alumina hydrate was dispersed in ion-exchanged water to obtain a 15% dispersion. Next, polyvinyl alcohol (Nippon Synthetic Chemical Industry Co., Ltd., Gohsenol NH1)
8) was dissolved and dispersed in ion-exchanged water to obtain a 10% solution. The alumina hydrate and the polyvinyl alcohol solution were mixed at a weight ratio of 10: 1 and stirred to prepare a coating dispersion. After die coating the coating dispersion using a coating machine and a hot air drying furnace (not shown),
After drying (drying temperature 140 ° C.), a porous inorganic pigment layer 103 having a thickness of 35 μm was formed. At this time, the pore diameter of the coating layer was 8 to 18 nm.

Next, in order to form the porous polymer resin layer 104, an aqueous polyester resin dispersion (average particle diameter of emulsion resin: 1.0 μm, minimum film forming temperature: 100 ° C.)
The coating liquid having a glass transition temperature of 57 ° C. and a solid concentration of 30.0%) was die-coated using a coating machine and a hot-air drying furnace (not shown), and then dried (drying temperature 60 ° C.).
An 8 μm porous polymer resin layer 103 was formed to obtain a recording medium 100. At this time, the pore diameter of the coating layer is 30 to
It was 100 nm.

Using a not-shown ink-jet printer provided with a transport mechanism, the solid pattern shown in FIG. 7 and the line pattern shown in FIG. 8 were printed on the recorded material 100. At this time, an experimental machine equipped with a head having an orifice diameter of 40 × 40 μm × 64 nozzles × 4 was used as the ink jet printer. Print density 200%, 300
% And 400%.

The ink is a black monochromatic pigment ink.
The ink composition was as follows. Pigment carbon black 1
The particle diameter of the aggregate of the secondary particles was 50 to 250 nm.

Carbon black (MCF88: Mitsubishi Kasei) dispersion 20 parts Diethylene glycol 5 parts Glycerin 1 part Ion exchange water 68 parts Isopropyl alcohol 1 part Here, the pore diameter distribution of the porous polymer resin layer and the pigment component The degree of overlap in the particle size distribution was 4.3%.

After completion of printing, the recording material was put into a hot-air drying furnace (not shown), kept at 140 ° C. for 1 minute, and thermally fixed to obtain a recorded matter. At this time, in order to prevent curling of the recorded matter, a jig capable of fixing the end was provided. After the heat fixing, the recorded matter was returned to room temperature and removed from the jig.

Regarding the above recording medium and recorded matter (1)
-(7) were evaluated. The evaluation results are shown in Table 1.
Here, the evaluation was judged to be acceptable when there was no evaluation result of X for all items.

(Evaluation) (1) Ink Absorption Rate (Dryability) After printing, the time during which the printed portion of the recorded matter before fixing was lightly touched with a finger was measured. (Amount of single color ink 400%) (Standard) ○ Stains within 10 seconds, Δ within 60 seconds, × 60 seconds or more

(2) Absorbing ability (bleeding, beading) The printed portion of the printed and fixed printed matter was visually observed,
The occurrence of beading was checked. (Criterion) ◎ No occurrence at 400%, ○ No occurrence at 300%, △ No occurrence at 200%, × 200%

(3) Ink Fixing Property (Scratch Resistance, Water Resistance) The printed portion of the printed and fixed recorded matter is rubbed with a cloth soaked with water. (Criterion) ○ No change, × Pigment adheres to cloth

(4) Image Transmission Density (OD) after Processing The image density of the printed portion of the printed and fixed recording material was measured from the printing side using a Macbeth densitometer RD-918. (400% of single color ink)

(5) Resolution of Recorded Image The recorded matter fixed and printed was projected by a film projection shakasten and visually observed. (Criterion) ○ A line with a pitch width of 0.2 mm and a thickness of 0.1 mm is clearly discriminated, Δ slightly distorted, × remarkable distortion

(6) Storage Stability (Temperature, Humidity) The printed and fixed printed matter is placed in an environmental tester capable of maintaining a temperature of 45 ° C. and a relative humidity of 95%. After 240 hours, the print quality taken out and the degree of discoloration (fading) were confirmed. (Criterion) ○ No change, △ Bleed or slightly discolored, × Severe bleeding or complete fading

(7) Storage stability (light fastness, ozone fastness) The recorded matter having been printed and fixed was exposed to a room for three months, and the degree of discoloration (
(Fading) was confirmed. (Standard) ○ No change at all, △ Slightly discolored, × Completely fading

Comparative Example 1 A recording medium was obtained in the same manner as in Example 1, except that the porous polymer resin layer was not provided as the upper layer. Continuous printing was performed on this recording medium by the same ink jet printer as in Example 1, and the ink was dried to obtain a recorded matter. Then, (1)-
The evaluation of (7) was performed. The evaluation results are shown in Table 1.

Comparative Example 2 The procedure of Example 1 was repeated except that the pore diameter distribution of the pores in the upper porous polymer resin layer was increased so as to overlap the particle diameter distribution of the pigment component of the ink. A recording medium was obtained. At this time, the average particle diameter of the polyester resin used for the coating liquid for the upper porous polymer resin layer was 6 μm. The drying temperature is 60 ° C and the film thickness is 18μ.
m. At this time, the pore diameter of the pores of the porous polymer resin layer is 120 to 360 nm, and the degree of overlap between the particle diameter distribution of the pigment component and the pore diameter distribution of the porous polymer resin layer is 5 nm.
8%. Continuous printing was performed on this recording medium using the same inkjet printer as in Example 1, and heat fixing was performed in the same manner as in Example 1 to obtain a recorded material. Thereafter, evaluations (1) to (7) were performed in the same manner as in Example 1. The evaluation results are shown in Table 1.

Comparative Example 3 A recording medium was obtained in the same manner as in Example 1, except that the upper layer was replaced with a porous inorganic pigment layer. Here, a silica gel layer was formed as the porous inorganic pigment layer. In order to form a silica gel layer, a silica sol having a primary particle diameter of 10 to 20 nm and a polyvinyl alcohol copolymer having a silanol group (Kuraray Co., Ltd., R
-Polymer R-1130) and a silica sol coating liquid having a solid content of 5% (the copolymer / SiO2 = 0.3). After die coating on the lower layer with a coating machine not shown, 14
After drying at 0 ° C., a 10 μm thick silica gel layer was provided as an upper layer to obtain a recording medium. At this time, the pore diameter of the coating layer was 5 to 15 nm. Continuous printing was performed on this recording medium by the same inkjet printer as in Example 1,
The ink was dried to obtain a recorded matter. Thereafter, evaluations (1) to (7) were performed in the same manner as in Example 1. The evaluation results are shown in Table 1.

Comparative Example 4 A recording medium was obtained in the same manner as in Example 1 except that the upper layer was replaced by a water-soluble resin layer. Here, in order to form a water-soluble resin layer, polyvinylpyrrolidone (PVP K15 manufactured by Gokyo Sangyo Co., Ltd.)
Using a 0% aqueous solution as a coating solution, the lower layer was die-coated and dried at 80 ° C. by a drier of a coating machine (not shown), and dried at 140 ° C.
A heat treatment was performed at ℃ to provide a 5 μm-thick polyvinylpyrrolin layer as an upper layer to obtain a recording medium. Continuous printing was performed on this recording medium using the same ink jet printer as in Example 1, and the ink was dried to obtain a recorded matter. Thereafter, evaluations (1) to (7) were performed in the same manner as in Example 1. The evaluation results are shown in Table 1.

Example 2 A recording medium was obtained in the same manner as in Example 1 except that the upper porous polymer resin layer was changed to a layer made of polyurethane resin. Here, in order to obtain an upper porous polymer resin layer, an aqueous polyurethane resin dispersion (emulsion resin having an average particle diameter of 0.8 μm, a minimum film forming temperature of 110 ° C., a glass transition temperature of 53 ° C., and a solid content of 30. (Prepared to 0%). The drying temperature was 60 ° C. and the film thickness was 18 μm. At this time, the pore diameter of the pores of the porous polymer resin was 36 to 112 nm, and the degree of overlap between the particle size distribution of the pigment component and the pore diameter distribution of the porous polymer resin layer was 5.2%. Was. Continuous printing was performed on this recording medium using the same ink jet printer as in Example 1, and heat fixing was performed in the same manner as in Example 1 to obtain a recorded material. Thereafter, evaluations (1) to (7) were performed in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 3 A recording medium was obtained in the same manner as in Example 1 except that the upper porous polymer resin layer was changed to a layer made of a styrene / acrylic copolymer resin.
Here, in order to obtain an upper porous polymer resin layer, an aqueous styrene-acrylic copolymer resin dispersion (average particle diameter of emulsion resin 1.2 μm, minimum film forming temperature 109 ° C., glass transition temperature 53 ° C., (Adjusted to 30.0% solid content)
Was used. The drying temperature is 60 ° C and the film thickness is 18μm
And At this time, the pore diameter of the pores of the porous polymer resin is 41 to 124 nm, and the degree of overlap between the particle diameter distribution of the pigment component and the pore diameter distribution of the porous polymer resin layer is 6.4%.
Met. Continuous printing was performed on this recording medium using the same ink jet printer as in Example 1, and heat fixing was performed in the same manner as in Example 1 to obtain a recorded material. Then, Example 1
(1) to (7) were evaluated in the same manner as described above. The evaluation results are shown in Table 2.

(Example 4) In Example 1, the lower inorganic pigment resin layer was a porous silica gel layer, and the inorganic particles were made of colloidal silica (Adelite CT-1 manufactured by Asahi Denka Co., Ltd.).
A recording medium was obtained in the same manner except that the above (00) was used. At this time, the thickness of the lower inorganic particle layer is 30 μm. At this time, the pore diameter was 6 to 24 nm. A recording medium was obtained by forming a polyester resin layer of 18 μm as a porous polymer resin layer on the upper layer in the same manner as in Example 1. Next, printing and heat fixing were performed with an ink jet printer in the same manner as in Example 1 to obtain a recorded material. Thereafter, evaluations (1) to (7) were performed in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 5 The same procedure as in Example 1 was carried out except that the polyester layer was formed directly on the substrate and no lower layer was provided. At this time, a recording medium was obtained with the polyester layer having a thickness of 40 μm. The pore diameter of the pores of the porous polymer resin is in the range of 30 to 96 nm, and the degree of overlap between the pore diameter distribution of the porous polymer resin layer and the particle size distribution of the pigment component is 4.6%. there were. In the same manner as in Example 1, printing and heat fixing were performed with an ink jet printer to obtain a recorded matter. Then, as in the first embodiment, (1)
-(7) were evaluated. The evaluation results are shown in Table 2.

Example 6 The same procedure was performed as in Example 1, except that a face dye ink prepared by adding a dye component as a toning material to the pigment ink was used. As in Example 1, a recording medium was obtained by forming an alumina porous layer as a lower layer and a polyester resin layer as an upper layer. The ink used was an ink containing 1.0% by weight of CI Food Black 2 as a dye component. In the same manner as in Example 1, printing and heat fixing were performed with an ink jet printer to obtain a recorded matter. Thereafter, evaluations (1) to (7) were performed in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 7 The same procedure was performed as in Example 1 except that the pigment inks were changed to yellow, magenta, and cyan. A recording medium was obtained by forming an alumina porous layer as a lower layer and a polyester resin layer as an upper layer in the same manner as in Example 1. The pigment components used in the ink were CI Pigment Yellow 74, Pigment Blue 15, and CI Pigment Red 112 to prepare respective pigment inks. At this time, the particle diameter of the aggregate of the primary particles of the pigment is in the range of 50 to 300 nm, and the degree of overlap between the pore diameter distribution of the porous polymer resin layer and the particle diameter distribution of the pigment component is 5.3%. Met.

In the same manner as in Example 1, printing and heat fixing were performed with an ink jet printer to obtain a recorded matter. afterwards,
When the evaluations (1) to (7) were performed in the same manner as in Example 1, it was determined to be acceptable as in Example 1.

Example 8 The procedure of Example 1 was repeated, except that a 100 μm-thick polyester film (Lumirror, manufactured by Toray Industries, Inc.) was used as a white film as the base material. A recording medium was obtained by forming a polyester resin layer on the upper layer. Next, printing and heat fixing were performed with an ink jet printer in the same manner as in Example 1 to obtain a recorded material. Then, (1)-
The evaluation of (7) was performed. The evaluation (4) of the image density was evaluated using a Macbeth reflection densitometer RD-1255. As a result, it was determined to be acceptable as in Example 1.

Example 9 In this example, the average particle diameter of the emulsion resin particles forming the upper layer was set to 0.0
The thickness was changed from 5 μm to 10.0 μm to provide porous polymer resin layers having different pore diameter distributions. In the same manner as in Example 1, an alumina porous layer was formed as a lower layer, and an upper layer was formed using a polyester emulsion resin having each particle diameter to obtain a recording medium. Next, printing and heat fixing were performed with an ink jet printer in the same manner as in Example 1 to obtain a recorded material.
Thereafter, evaluations (1) to (7) were performed in the same manner as in Example 1. The evaluation results are shown in Table 3.

Example 10 In this example, a porous polymer resin layer was provided using a coating liquid in which two types of emulsion resins having different average particle diameters of the emulsion resin particles forming the upper layer were mixed. . In the same manner as in Example 1, a recording medium was obtained by forming an alumina porous layer as a lower layer and a porous polymer resin layer as an upper layer. At this time, the average particle diameter of the polyester emulsion A was 2.5 μm, and the average particle diameter of the polyester emulsion B was 0.2 μm, each of which was mixed at a ratio of 5: 1. At this time, both the glass transition temperature of the polyester resin emulsion was 57 ° C., and the minimum film formation temperature was 100 ° C. after mixing. The pore diameter of the pores of the porous polymer resin is in the range of 26 to 121 nm, and the degree of overlap between the pore diameter distribution of the porous polymer resin layer and the particle diameter distribution of the pigment component is 6.1%. there were.

Next, in the same manner as in Example 1, printing and heat fixing were performed with an ink jet printer to obtain a recorded material. Thereafter, evaluations of (1) to (7) were performed in the same manner as in Example 1, and it was determined to be acceptable as in Example 1.

(Embodiment 11) This embodiment is the same as the embodiment 1 except that the heat fixing and the pressure treatment are performed in addition to the heat treatment.
Was performed in the same manner as described above. Here, a heat roll laminator (not shown) was used at the time of heat fixing. At this time, by making the upper and lower roll surfaces smooth, the printed surface of the recorded matter had improved smoothness. Further, by providing a matting process with a pitch of 0.5 μm and a depth of 0.5 μm on the upper and lower roll surfaces, a recorded material having a small reflection on the printed surface of the recorded material was obtained. Thereafter, evaluations of (1) to (7) were performed in the same manner as in Example 1, and it was determined to be acceptable as in Example 1.

[0110]

[Table 1]

[0111]

[Table 2]

[0112]

[Table 3]

[0113]

As described above, according to the present invention, at least a porous polymer resin layer is formed on a substrate, and a porous inorganic pigment layer is sequentially formed as necessary. By adjusting the overlap between the pore size distribution and the particle size distribution of the pigment component, when the pigment ink is printed, the pigment component is arranged near the surface of the porous polymer resin layer, and the image density is high and the resolution is high. Excellent recorded matter can be obtained. Further, by heating and making the porous polymer resin layer transparent, the fixation of the pigment ink is reliably performed, and the scratch resistance and water resistance can be improved. Further, when an ink containing a pigment component and a dye component is printed, each is uniformly arranged and fixed, a color tone can be obtained, and at the same time, a recorded matter and a recording method with good storage stability can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a recorded matter obtained by printing a pigment ink on a recording medium by an inkjet recording method of the present invention.

FIG. 2 is a cross-sectional view showing another example of a recorded matter obtained by printing a pigment ink on a recording medium by the inkjet recording method of the present invention.

FIG. 3 is a sectional view showing an example of a recording medium used in the present invention.

FIG. 4 is a sectional view showing another example of a recording medium used in the present invention.

FIG. 5 is a plan view showing an example of a relationship between an ink pigment and a porous polymer resin layer of a recording medium.

FIG. 6 is a graph showing an example of a relationship between a particle diameter of a pigment component in an ink used in the present invention and a pore diameter of a porous polymer resin layer.

FIG. 7 is a diagram showing an example of a print evaluation pattern used in an embodiment of the present invention.

FIG. 8 is a diagram showing another example of the print evaluation pattern used in the embodiment of the present invention.

FIG. 9 is a diagram illustrating an example of a recorded matter obtained by printing a pigment ink on a conventional recording medium.

FIG. 10 is an enlarged cross-sectional view of another example of a recorded material according to a conventional recording method, and FIG.

FIG. 11 is a diagram showing still another example of a recorded matter according to a conventional recording method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Substrate 102 Polymer resin layer 103 Porous inorganic particle layer 104 Porous polymer resin layer 200 Pigment 201 Dye 901 Polymer resin particle 902 Micropore

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naoki Kushida 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (16)

[Claims] 1. An ink jet recording method for performing recording on a recording medium having at least one porous polymer resin layer formed on a base material using an ink containing at least a pigment component, wherein the porous polymer When the pore diameter distribution of the resin layer and the particle diameter distribution of the pigment component are each a frequency distribution, the frequency of the entire pore diameter of the porous polymer resin layer overlaps the particle diameter distribution of the pigment component. The ratio of the frequency of the pore diameter of the porous polymer resin layer is 0.1% to 10%.
%, And after the image formation, the porous polymer resin layer is subjected to a heat treatment. 2. The ink jet recording method according to claim 1, wherein the pigment components are arranged within a range of 5 μm in a depth direction from the surface of the porous polymer resin layer. 3. The distribution of the pore diameter of the entire porous polymer resin layer is in a range of 10 to 300 nm, and 100 nm or less in a depth direction within 5 μm from the surface of the porous polymer resin layer. The inkjet recording method according to claim 1, wherein 4. The porous polymer resin layer has a thickness of 1 to 4
2. The ink jet recording method according to claim 1, wherein the thickness is in a range of 0 [mu] m. 5. The ink jet recording method according to claim 1, wherein the content of the pigment component in the ink is 0.1 to 20% by weight based on the whole ink. 6. The method according to claim 1, wherein a porous inorganic pigment layer is formed between the substrate and the porous polymer resin.
3. The inkjet recording method according to item 1. 7. The ink jet recording method according to claim 6, wherein the absorption amount of the porous inorganic pigment layer is larger than the absorption amount of the porous polymer resin layer. 8. The ink jet recording method according to claim 6, wherein the absorption speed of the porous polymer resin layer is higher than the absorption speed of the porous inorganic pigment layer. 9. The ink jet recording method according to claim 1, wherein a dye component is contained in the ink. 10. The ink jet recording method according to claim 9, wherein said dye component is passed through pores of said porous polymer resin layer and fixed in said porous inorganic pigment layer. 11. A base material having at least one polymer resin layer on a base material, wherein a pigment component of the ink is fixed near the surface of the polymer resin layer, and a dye component of the ink is fixed on the base material. Recorded matter characterized by the fact that: 12. The recorded matter according to claim 11, wherein the polymer resin layer is transparent. 13. The method according to claim 1, wherein the polymer resin layer is formed by densifying a porous polymer resin.
The recorded matter according to 1. 14. A porous inorganic pigment, wherein a porous inorganic pigment layer and a polymer resin layer are sequentially formed on a substrate, and a pigment component of ink is fixed near the surface of the polymer resin layer. A recorded matter, wherein the dye component of the ink is fixed in the layer. 15. The recorded matter according to claim 14, wherein the polymer resin layer is transparent. 16. The method according to claim 1, wherein the polymer resin layer is formed by densifying a porous polymer resin.
4. The recorded matter according to 4.