JP2003291332A - Inkjet recorder, inkjet recording method and inkjet recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray diagnosing apparatus which automatically adjusts a position of a top plate and/or an X-ray system so that an X-ray application direction to a concerned part of a body to be inspected of the X-ray system and a relative position between the X-ray system and the concerned part of the body to be inspected, the relative position between the X-ray system and the concerned part of the body to be inspected, or a position related to a body axis direction of the body to be inspected of the concerned part of the body to be inspected is maintained when a holder for holding the top plate where the body to be inspected is loaded, and the X-ray system is moved. <P>SOLUTION: When the X-ray system moves to rotate by a rotation angle ϕ with respect to a longitudinal direction of the top plate 1 and a center axis of X-ray beams moves from R<SB>1</SB>to R<SB>2</SB>, a control unit determines a rise/fall angle θ of the top plate 1 as θ=ϕ. Moreover, supposed that the concerned part moves from Q<SB>1</SB>to Q<SB>2</SB>in accordance with a move of the rise/fall angle θ of the top plate 1, the control unit determines a moving amount A' in relation to the longitudinal direction of the top plate 1 and a moving amount B' in relation to a perpendicular direction. The position of the top plate 1 is adjusted on the basis of these values, whereby a relative position between an X-ray application source and the concerned part Q of the body to be inspected is maintained. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording method and an inkjet recording apparatus for recording by ejecting ink onto a recording medium, and more specifically, an inkjet recording method having a step of correcting warpage of the recording medium. The present invention also relates to an inkjet recording apparatus having a unit for forcing the warp of the recording medium.

Furthermore, the present invention relates to an inkjet recording medium, and more particularly to an inkjet recording medium having improved curl characteristics.

[0003]

2. Description of the Related Art An ink jet recording apparatus for recording an image by ejecting ink in the form of fine droplets onto a recording surface of a recording medium has been improved in image quality by silver halide photography due to recent technological progress and cost reduction of the apparatus. As soon as it becomes possible, it has become popular rapidly.

In such an ink jet recording apparatus,
Since the image recording is performed by ejecting ink in the form of minute droplets, it is an essential condition that ink is appropriately landed at a predetermined position in order to realize higher quality image printing. Has been done. Therefore, for such a reason, it has been required to perform recording by bringing the recording head and the recording medium as close as possible to each other.

However, since the base material of the recording medium used in such an ink jet recording apparatus is mainly composed of a paper material or the like, the recording medium warps,
This may cause a problem that the recording medium comes into contact with the recording head of the inkjet recording apparatus.

As described above, when the recording medium warps and the recording medium comes into contact with the recording head of the ink jet recording apparatus, it is an essential condition for realizing higher quality image printing. Since it becomes impossible to satisfy "property of ink landing on a predetermined position", the image quality of an image print is deteriorated. In addition, contact with the recording head causes scratches and stains on the recording surface of the recording medium, and in the worst case, the recording medium is clogged inside the apparatus, so-called paper jam occurs.

Particularly, when the recording medium is a roll-shaped recording medium wound in a roll, the curl of the recording medium increases the degree of warpage of the recording medium. The problem of contact with the head became more serious.

Even if an attempt is made to set the distance between the recording medium and the recording head of the ink jet recording apparatus to an appropriate value in order to solve this contact problem, the degree of the warp changes depending on the characteristics of the recording medium. In addition, even in the case of the same recording medium, in a roll-shaped recording medium wound in a roll shape, the degree of warpage changes depending on the remaining amount of the winding, so that the recording medium and the inkjet It has been difficult to set the distance between the recording heads of the recording device to an appropriate value.

On the other hand, if the recording medium has a warp even after it is ejected from the ink jet recording apparatus, the stockability of the ejection tray on which the recording media are stacked is deteriorated. There was a problem. Furthermore, there is a problem that a recording medium having a warp has poor handleability, and it is difficult to handle it as a product or a product.

On the other hand, in recent years, high quality and high speed printing have been demanded in ink jet recording. For that purpose, an inkjet recording medium having improved ink absorption amount and ink absorption speed and improved glossiness has been required.

The ink jet recording medium is roughly classified into two types depending on the form of the ink absorbing layer. One is an inkjet recording medium having a swelling type ink absorbing layer, which is excellent in glossiness, but the ink absorbing speed is slow, and color bleeding or beading occurs,
Causes image quality deterioration.

On the other hand, a small amount of a water-soluble binder and a crosslinking agent,
And a void type ink jet recording medium having an ink absorbing layer composed of a porous void layer composed of a large amount of an inorganic pigment, which has a high ink absorbing speed and high image quality, but when the air is dry, etc. , It is easily cracked and fine cracks occur on the surface of the recording medium, degrading the image quality.

A stable film can be formed by increasing the amount of the water-soluble binder or water-absorbent resin used in these ink jet recording media. However, when a large amount of the water-soluble binder is used, environmental conditions, mainly humidity changes. As a result, the resin itself swells and contracts to cause a volume change, resulting in curling of the recording medium.

Even if resin fine particles are added in place of the water-soluble binder used in these ink absorbing layers to suppress environmental fluctuations, partial unevenness occurs immediately after recording with aqueous ink and absorbing the ink.

In particular, in the case of a so-called RC base paper in which both sides of the paper are coated with resin as the base material of the recording medium, the volume change due to the environmental change of the base material is small, so the expansion coefficient on the ink absorption layer side and the base material side. Difference becomes large, and curling is more likely to occur.

Further, in the continuous and large-scale production of images, the need for roll paper instead of sheets is increasing. Roll-shaped recording media are beginning to be used not only in commercial printers (large format printers) but also in personal printers.

Due to the handling property of the roll-shaped recording medium and the restrictions on the size of the apparatus, a core core having a small diameter is required, and the roll-shaped recording medium is already curled before printing. The recording medium has a curl.

If an image is recorded by ink jet with such a curl still occurring, the print quality may be deteriorated due to the contact with the head during recording or the change in the distance between the head and the recording medium as described above. If a problem occurs and curl or partial unevenness remains after printing, it not only impairs the quality when viewing images, but also when storing the recording medium in an album, frame, bag, etc. Becomes an obstacle to. Moreover, when the image is pasted on a wall or the like as it is, a part of the image may become invisible due to curling. If such a strong curl is forcibly corrected with a hand, the image portion may be damaged.

The present invention has been made in view of the above circumstances, and one of the objects thereof is an ink jet for which the warp of the recording medium is forced to be flat by subjecting the recording medium to heat and pressure treatment. Recording method and inkjet recording apparatus, further, according to the characteristics of the recording medium, the degree of warp, the remaining amount of winding, etc., by appropriately performing a heating and pressurizing process, the warp of the recording medium is corrected to be flat, (EN) An inkjet recording method and an inkjet recording apparatus capable of realizing high-quality image printing and capable of producing an image print without warpage.

Another object of the present invention is to provide an ink jet recording in which a straightening curl can be made almost flat when a specific curl is applied to a medium before printing and a specific heating and pressurizing process is simultaneously carried out. It is to provide a medium, and further to provide an image forming method using the medium.

[0021]

The above object can be achieved by the following constitutions.

The inkjet recording method according to claim 1 is a step of straightening the warp of the recording medium by applying heat and pressure to the recording medium; and after the straightening step, the straightening step is performed on the recording medium. It is characterized by having an image forming step of ejecting ink to form an image.

An ink jet recording method according to a second aspect of the invention is characterized by including a step of fixing the image by applying at least heat after the image forming step.

According to a third aspect of the present invention, there is provided an ink jet recording method, wherein an image forming step of forming an image by ejecting ink onto the recording medium; applying heat and pressure to the recording medium to form an image on the recording medium. A straightening process to straighten the warp;
And a fixing step of fixing the image by applying at least heat to the recording medium on which the image is formed.

An ink jet recording method according to a fourth aspect of the present invention is an image forming step of forming an image by ejecting ink onto a recording medium; and applying heat and pressure to the recording medium on which the image is formed. According to the inkjet recording method having a straightening step of straightening the warp of the recording medium, the recording medium contains a thermoplastic resin, and the heating temperature in the straightening step is lower than the temperature at which the thermoplastic resin melts. It is characterized by.

The ink jet recording method according to claim 5 is an image forming step of forming an image by ejecting ink onto a recording medium having an ink absorbing layer containing an inorganic pigment and a water-soluble binder on a support. And an inkjet recording method including a correction step of correcting the warp of the recording medium by applying heat and pressure to the recording medium, wherein the recording medium has a curl value of -30 to -40 mm. On the other hand, when the heating / pressurizing treatment is applied under the following heating / pressurizing conditions, the curl value of the recording medium is −
Inkjet recording method characterized by 10 to +10 mm: heating and pressurizing conditions: a cylindrical iron cylinder having a diameter of 30 mm, and a diameter 30 at a position facing the iron cylinder.
mm silicon rubber roller is coated with a tetrafluoroethylene-perfluoroalkyl ether copolymer together, and a fixing device having a heater inside an iron cylinder is used, and the recording medium is inserted so that the iron cylinder contacts the surface of the ink absorption layer. A conveying speed of the recording medium of 10 mm / s,
Nip width 0.3 mm, linear pressure 3 for width 297 mm
Simultaneous heating and pressurization is performed under the conditions of 2 kgf, the surface temperature of the iron cylinder is 120 ° C., and the coating thickness of the tetrafluoroethylene-perfluoroalkyl ether copolymer with which the iron cylinder is coated is 100 μm.

An ink jet recording method according to a sixth aspect is characterized in that the mass ratio of the inorganic pigment to the water-soluble binder in the ink absorbing layer of the recording medium is 3: 1 to 9: 1. is there.

In the ink jet recording method according to the seventh aspect, in the recording medium, the ink absorbing layer has a Tg of
Is 20 ° C. or less and contains an emulsion resin containing polyvinyl alcohol as a dispersion medium.

The ink jet recording method according to claim 8 is characterized in that the recording medium has a surface layer containing a thermoplastic resin on the ink absorbing layer.

The ink jet recording method according to a ninth aspect is characterized in that the surface layer further contains an inorganic pigment.

An ink jet recording method according to a tenth aspect of the invention is characterized in that the heating temperature in the straightening step is lower than the temperature at which the thermoplastic resin melts.

In the ink jet recording method according to claim 11, the center line average roughness of the ink absorbing layer defined by JISB-0601 has a reference length of 2.5 mm and a cutoff value of 0.8 mm. It is characterized in that the measured value is 0.8 or more and 4 or less.

The ink jet recording method according to a twelfth aspect is characterized in that the ink is a pigment ink.

An ink jet recording apparatus according to a thirteenth aspect of the present invention includes a straightening device that straightens the warp of the recording medium by applying heat and pressure, a recording head that ejects ink, and a conveying section that conveys the recording medium. In the inkjet recording apparatus, the straightening device is arranged upstream of the recording head in the transport direction of the recording medium.

In the ink jet recording apparatus according to the fourteenth aspect, the straightening device has a heating roller having a heating device and a pressure roller having a pressure device provided at a position facing the heating roller. It is characterized by.

According to the fifteenth aspect of the present invention, in the ink jet recording apparatus, the straightening device has a driven belt driven by the heating roller, and a pressing portion provided at a position facing the driven belt. It is a thing.

According to a sixteenth aspect of the present invention, in the ink jet recording apparatus, the straightening device is driven by the heating roller.
A driven roller, a heating belt suspended by the heating roller and the first driven roller, a second driven roller driven by the pressure roller, and a pressure belt suspended by the pressure roller and the second driven roller. It is characterized by having.

In the ink jet recording apparatus according to the seventeenth aspect, the correction means includes a heating and pressing roller having a heating means and a pressing means, a driven roller driven by the heating and pressing roller, the heating and pressing roller, and the heating and pressing roller. It has a heating belt suspended on the driven roller, and a drum roller provided at a position facing the heating belt.

In the ink jet recording apparatus according to the eighteenth aspect, the straightening means is a pressure roller having a pressure means,
A driven roller driven by the pressure roller, a pressure belt suspended between the pressure roller and the driven roller, and a heating drum roller having a heating unit provided at a position facing the pressure belt. It is characterized by.

An ink jet recording apparatus according to a nineteenth aspect of the invention is characterized in that the heating roller and the pressure roller have hardnesses different from each other, and a difference in hardness between them is not less than twice. is there.

In the ink jet recording apparatus according to a twentieth aspect, one of the heating roller and the pressure roller is a metal roller and the other is a rubber roller.

An ink jet recording apparatus according to a twenty-first aspect is characterized in that the metal roller is provided on the side where the warp of the recording medium is convex.

In the ink jet recording apparatus according to the twenty-second aspect, the recording apparatus inputs the thickness and type of the recording medium, and the control means for controlling the heating temperature according to the input by the input means. It is characterized by having.

In an ink jet recording apparatus according to a twenty-third aspect, the recording apparatus detects the degree of warpage of the recording medium, and a control means for controlling the heating temperature according to the output from the detecting means. It is characterized by having.

In the ink jet recording apparatus according to a twenty-fourth aspect, the recording medium is a roll-shaped recording medium, and the recording apparatus detects the remaining amount of the roll-shaped recording medium, and the detection means. And a control means for controlling the heating temperature according to the output of.

In the ink jet recording apparatus according to the twenty-fifth aspect of the present invention, the recording apparatus controls the inputting means for inputting the thickness and type of the recording medium, and controlling the pressurizing pressure according to the input by the inputting means. And means.

In the ink jet recording apparatus according to a twenty-sixth aspect, the recording apparatus controls the detection means for detecting the degree of warp of the recording medium, and the pressurization pressure control according to the output from the detection means. It is characterized by having means.

According to a twenty-seventh aspect of the present invention, in the ink jet recording apparatus, the recording medium is a roll-shaped recording medium, and the recording apparatus detects the winding remaining amount of the roll-shaped recording medium, and the detection means. It is characterized by having a control means for controlling the pressurizing pressure according to the output of.

An ink jet recording apparatus according to a twenty-eighth aspect is characterized in that the recording apparatus has a guide for holding the recording medium flat on the downstream side of the straightening device in the conveying direction of the recording medium. Is. According to a twenty-ninth aspect of the invention, the ink jet recording apparatus is characterized in that the recording medium is conveyed with the side where the warp of the recording medium is convex as the upper surface.

An ink jet recording apparatus according to a thirtieth aspect of the invention is a straightening apparatus for correcting warpage of a recording medium by applying heat and pressure, a recording head for ejecting ink, a conveying section for conveying the recording medium, and at least It has a fixing device having a heating unit.

An ink jet recording medium according to a thirty-first aspect has an ink absorbing layer containing an inorganic pigment and a water-soluble binder on a support, and a surface layer containing a thermoplastic resin on the ink absorbing layer. In the inkjet recording medium, when the recording medium has a curl value of −30 to −40 mm, the curl value of the recording medium is − when the heat and pressure treatment is applied under the following heating and pressurizing conditions. The inkjet recording medium is characterized by having a size of 10 to +10 mm. Heating and pressurizing conditions: a cylindrical iron cylinder having a diameter of 30 mm and a silicon rubber roller having a diameter of 30 mm at a position facing the iron cylinder are both covered with a tetrafluoroethylene-perfluoroalkyl ether copolymer, and a heater is provided in the iron cylinder. The recording medium is inserted so that the iron cylinder is in contact with the surface of the ink absorbing layer using a fixing device having a built-in recording medium, and the conveying speed of the recording medium is 10 m.
m / s, nip width 0.3 mm, linear pressure 32 kgf for width 297 mm, iron cylinder surface temperature 120 ° C., coating thickness of tetrafluoroethylene-perfluoroalkyl ether copolymer coating iron cylinder To 100 μm
Simultaneous heating and pressurizing treatment are performed under the conditions of.

An ink jet recording medium according to a thirty-second aspect of the invention is characterized in that the surface layer further contains an inorganic pigment.

[0053]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an ink jet recording apparatus according to the present invention will be described below. FIG. 1 is a schematic configuration diagram of an inkjet recording apparatus according to this embodiment. FIG. 2 is a schematic configuration diagram showing another example of the inkjet recording apparatus according to the present embodiment.

[First Embodiment] FIG. 1 shows a schematic structure of an ink jet recording apparatus according to this embodiment. As shown in the figure, the ink jet recording apparatus according to the present embodiment mainly performs a heating and pressurizing process on the recording medium original winding 2 in which the recording medium 1 is wound in a roll shape and the recording medium 1. A straightening unit 3 that is a unit that straightens the warp and a holding unit 4 that is a unit that flatly holds the recording medium 1 after straightening.
And a recording medium transport unit 5 that is a means for transporting the recording medium 1.
The recording head 6 is a unit for recording a predetermined image on the recording surface of the recording medium 1, and the cutting unit 7 is a unit for cutting the recording medium after recording into a predetermined size.

The recording medium 1 is a roll-shaped recording medium wound so that its recording surface is on the outside, and is a conveying roller (driving roller) provided in the recording medium conveying section 5.
The recording medium original winding 2 is pulled out by the 51 and the driven roller 52, and is conveyed rightward in the drawing.

The positions and number of the conveying rollers (driving rollers) 51 and the driven rollers 52 are not limited to the above.

As the recording medium 1, it is possible to use a sheet-shaped recording medium which is cut into a predetermined size in advance. In such a case, the ink jet recording apparatus is as shown in FIG. Form, that is, the cutting portion 7
Shall be omitted.

FIG. 3 shows a partially enlarged view of the vicinity of the correction section 3 (see FIG. 1). As shown in FIG.
Is mainly composed of a heating roller 31 having a heating means, and a pressure roller 32 having a pressure means provided at a position facing the heating roller 31. The heating roller 31 is made of a hollow metal roller and has a heating element 31a such as a halogen heater as a heat source built therein along the axial direction thereof. Then, the heating roller 31 is heated by the heat generated by the heating element 31a, and the warp of the recording medium 1 pressed by the heating roller 31 is corrected by the heat. The pressure roller 32 is a rubber roller, and the heating roller 31
It has a pressing portion 32a composed of a spring or the like for pressing the pressing roller 32 toward. And the pressurizing section 32a
The pressing roller 32 causes the pressing roller 32 to move to the heating roller 31.
The recording medium 1 which is pressed to and is sandwiched between these rollers.
The warp is corrected by pressure.

Further, the heating roller 31 and the pressure roller 32 are heated by the heating roller 31 and the heating temperature by the heating roller 31 according to the input contents from the input unit 8 which is a means for inputting the thickness and type of the recording medium 1. The control unit 9 is connected to the control unit 9 that is a unit that controls the pressure applied by the pressure roller 32. When the user inputs the thickness and type of the recording medium from the input unit 8, the control unit 9 causes The heating temperature of the heating roller 31 and the pressure applied by the pressure roller 32 are appropriately controlled according to the thickness and type of the recording medium 1.

Further, the heating roller 31 and the pressure roller 32 have a warp sensor 10 such as a proximity sensor which is a means for detecting the degree of warpage of the recording medium 1 and the remaining amount of the recording medium original winding 2. Connected to a control unit 9 that is a unit that controls the heating temperature of the heating roller 31 and the pressure applied by the pressure roller 32 according to the detection result from the remaining amount sensor 11 such as a proximity sensor that is a detection unit. Based on the detection results from the warp sensor 10 and the remaining winding amount sensor 11, the control unit 9 appropriately adjusts the degree of warpage of the recording medium and the remaining winding amount of the recording medium original winding 2. The heating temperature of the heating roller 31 and the pressure applied by the pressure roller 32 are controlled.

The control of the heating temperature by the heating roller 31 is performed by the control section 9 controlling the electric power supplied to the heating element 31a inside the heating roller 31. As a result, the surface temperature of the heating roller 31 is maintained within an appropriate temperature range, and the warp of the recording medium 1 can be satisfactorily corrected. Specifically, 60 ℃
It is preferable that the temperature is in the range of 130 ° C. or higher to satisfactorily correct the warp of the recording medium, and further 80 ° C. or higher and 1
It is preferably in the range of 00 ° C or lower.

The control of the pressure applied by the pressure roller 32 is performed by the control unit 9 controlling the pressure applied to the pressure roller 32 by the pressure unit 32a. For example, the pressurizing unit 32a includes a spring 32b, an eccentric cam 32c, and the like, and the control unit 9
By controlling the rotational position of a drive motor (not shown) connected to the eccentric cam 32c, the pressing force of the spring 32b on the pressure roller 32 is controlled. As a result, the pressure applied by the pressure roller 32 to the recording medium 1 is appropriately controlled, and the warp of the recording medium 1 can be satisfactorily corrected.

FIG. 4 shows a partially enlarged view of the vicinity of the heating roller 31 and the pressure roller 32. As described above, since the heating roller 31 is a metal roller and the pressure roller 32 is a rubber roller, the recording medium 1 which is conveyed while being sandwiched between them is emphasized in the drawing. The state shown in FIG. That is, the heating roller 3 which is the metal roller has a surface on which the warp of the recording medium is convex.
When the recording medium 1 is conveyed between these rollers after being set to the 1 side, the warp of the recording medium 1 is forced in the opposite direction, so that the recording medium 1 is corrected to be flat. By adding the effect of heating and pressurization to this, the warp of the recording medium 1 is corrected more evenly.

The hardness difference between the heating roller 31 and the pressure roller 32 is preferably twice or more. The implementation results that are the basis for this are shown below.

The evaluation was performed using the following three stages. A: The warp was completely corrected B: The warp was slightly corrected but was almost corrected C: There was no problem in practical use, but the warp remained. Result of execution 1; Roller hardness difference 1 time ... Correction condition: C Implementation result 2; Roller hardness difference 1.3 times ... Correction degree of warp of recording medium: C Implementation result 3; Roller hardness difference 1.5 times ... Correction degree of recording medium warp: C Execution result 4: Roller hardness difference of 1.8 times ... Correction of warp of recording medium: B Execution result 5: Roller hardness difference of 2 times or more ... Correction of warp of recording medium: A

As described above, when the hardness difference between the heating roller 31 and the pressure roller 32 is double or more, it is confirmed that the warp of the recording medium 1 is appropriately corrected. The hardness difference of the pressure roller 32 is 2
It has been determined that it is preferably twice or more.

Therefore, the rubber material forming the pressure roller 32 is K-6253 (IS
According to the hardness measurement method defined in O 48-1994 and ISO 7619-1997), the hardness of the metal material of the heating roller 31 should be half or less.

Further, the correction section 3 is provided with the heating roller 3
Since the recording medium 1 is composed of a pair of rollers, the pressure roller 32 and the pressure roller 32, it is preferable that the recording medium 1 is conveyed with its convex surface as the upper surface. This is
As shown in FIG. 5A, when the recording medium 1 is conveyed with the surface having the convex warp as the upper surface, the recording medium 1 relatively smoothly enters the correction section 3, while FIG. As shown in b), when the surface of the recording medium 1 having a convex warp is conveyed as the lower surface, the leading end of the recording medium 1 hits the correction section 3 and smoothly enters the correction section 3. It is impossible to do it. As described above, when the recording medium 1 is prevented from smoothly entering the correction portion 3, the recording surface of the recording medium 1 may be scratched, wrinkled, or the like. It is assumed that the convex surface is conveyed as the upper surface.

The holding portion 4 is subordinate to the correction portion 3 and is provided at a position downstream of the correction portion 3 in the recording medium conveyance direction. In order to maintain the flatness of the recording medium 1 that has been heated and pressed by the correction unit 3,
After the heat and pressure treatment, the flatness needs to be maintained until it is sufficiently cooled. Therefore, this is done by providing the holding portion 4. The holding portion 4 is formed flat by a sheet metal or the like, and the recording medium 1 is sandwiched from the upper and lower sides to straighten it.

The correction unit 3 and the holding unit 4 described above are
By providing the recording head 6 on the upstream side in the recording medium conveyance direction, the warp of the recording medium 1 is corrected before the recording by the recording head 6 is performed. As a result, good recording is performed by the recording head 6.

However, the corrector 3 and the holder 4
May be provided at a position immediately before the sheet is discharged, that is, at the downstream side of the cutting unit 7 in the recording medium conveyance direction for the purpose of preventing the recording medium after the sheet from being warped. In reality, the warp of the recording medium after the paper discharge is also a very serious problem, and thus such a form is also preferably used.

In such a case, the ink jet recording apparatus has a configuration as shown in FIG. 6, that is, the correction section 3 and the holding section 4 are provided at the downstream position of the cutting section 7 in the recording medium conveying direction. It shall take the form.

Returning to FIG. 1, the description will be continued. The recording medium transporting section 5 includes a transporting roller 51 that is rotationally driven by a drive motor (not shown), and a driven roller 52 that is provided at a position facing the transporting roller 51.
The recording medium 1 is sandwiched between the conveying roller 21 and the driven roller 22, and the rotational driving of the conveying roller 21 allows the recording head 6 to be described later to record an image and the cutting unit 7 to cut the sheet. Accordingly, the recording medium 1 is configured to be conveyed by a predetermined amount in the right direction in the drawing.

The recording head 6 is constructed so as to be movable in the main scanning direction along a scanning guide (not shown) which is provided over the width direction of the recording medium 1 so as to be substantially orthogonal to the conveying direction of the recording medium 1. It is a reciprocating scanning type recording head. The recording head 6 has a plurality of ink tanks that store inks of colors such as Y (yellow), M (magenta), C (cyan), and K (black), and moves in the main scanning direction along a scanning guide. However, by ejecting a predetermined ink at a predetermined timing according to the image data, a predetermined image is recorded on the recording surface of the recording medium 1 in cooperation with the conveyance of the recording medium 1 by the conveying means 5. Form.

The cutting unit 7 is, for example, the recording medium 1
A reciprocating scanning circular cutter configured to be movable in the main scanning direction along a scanning guide (not shown) that is installed across the width direction of the recording medium 1 so as to be substantially orthogonal to the conveyance direction of the recording medium 1. A controller 7 (not shown) cuts the recording medium 1 into a predetermined size. The cutting unit 7
The installation position of is not limited to this, for example,
It may be provided on the upstream side of the straightening unit 3 in the recording medium conveyance direction.

The recording medium 1 cut into a predetermined size by the cutting unit 7 is discharged to the outside of the ink jet recording apparatus, that is, to the paper discharge tray.

[Second Embodiment] Next, an ink jet recording apparatus for performing a fixing process on a recording medium will be described.

FIG. 7 shows a schematic structure of the ink jet recording apparatus in this embodiment. As shown in the figure, the ink jet recording apparatus according to the present embodiment mainly performs a heating and pressurizing process on the recording medium original winding 2 in which the recording medium 1 is wound in a roll shape and the recording medium 1. A straightening unit 3 that is a unit that straightens the warp, a holding unit 4 that is a unit that holds the straightened recording medium 1, a recording medium transport unit 5 that is a unit that transports the recording medium 1, and a recording unit. A recording head 6 which is means for recording a predetermined image on the recording surface of the medium 1.
And a cutting unit 7 that is a unit that cuts the recording medium after recording into a predetermined size, and a unit that performs a fixing process of the ink absorption layer on the recording medium surface layer by subjecting the recording medium to heat and pressure processing. The fixing unit 12 is a fixing unit 12.

The recording medium 1 is a so-called recording medium having an ink absorbing layer on the surface layer, and is a roll recording medium wound so that the recording surface having the ink absorbing layer is on the outside. As a recording medium preferably used in the inkjet recording apparatus in the present embodiment, the ink absorbing layer JIS standard B-0601 (ISO 468-1) is used.
982, ISO 3274-1975, ISO 428
7 / 1-1984, ISO 4287 / 2-1984 and I
(Corresponding to SO 4288-1985), the center line average roughness has a reference length of 2.5 mm and a cutoff value of 0.
Those that satisfy the conditions of 0.8 or more and 4 or less when measured at 8 mm can be cited. By using such a recording medium, the warp of the recording medium can be satisfactorily corrected. The recording medium 1 is pulled out from the recording medium original winding 2 by a conveying roller (driving roller) 51 and a driven roller 52 provided in the recording medium conveying unit 5 and conveyed rightward in the drawing.

The installation position and the number of the transport roller (driving roller) 51 and the driven roller 52 are not limited to the above.

Further, as the recording medium 1, it is possible to use a sheet-shaped recording medium which is cut into a predetermined size in advance, and in such a case, the ink jet recording apparatus as shown in FIG. In addition, the cutting section 7 is omitted.

FIG. 3 is applied correspondingly to a partial enlarged view of the vicinity of the correction section 3 (see FIG. 7). As shown in the figure, the straightening unit 3 mainly includes a heating roller 31 having a heating unit.
And a pressure roller 32 having a pressure means provided at a position facing the heating roller 31. The heating roller 31 is made of a hollow metal roller and has a heating element 31a such as a halogen heater as a heat source built therein along the axial direction thereof. Then, the heating roller 31 is heated by the heat generated by the heating element 31a, and the warp of the recording medium 1 pressed by the heating roller 31 is corrected by the heat. Also,
The pressure roller 32 is made of a rubber roller, and has a pressure unit 32 a made of a spring or the like that presses the pressure roller 32 toward the heating roller 31. Then, the pressing roller 32 is pressed against the heating roller 31 by the pressing force of the pressing portion 32a, and the warp of the recording medium 1 sandwiched between these rollers is corrected by the pressure.

The heating roller 31 and the pressure roller 32 are heated by the heating roller 31 according to the contents input from the input unit 8 which is a means for inputting the thickness and type of the recording medium 1. The control unit 9 is connected to the control unit 9 that is a unit that controls the pressure applied by the pressure roller 32, and the user inputs the thickness and type of the recording medium 1 from the input unit 8 to thereby control the control unit. 9 is configured to appropriately control the heating temperature by the heating roller 31 and the pressure applied by the pressure roller 32 according to the thickness and type of the recording medium 1.

Further, the heating roller 31 and the pressure roller 32 detect the degree of warpage of the recording medium 1 and the warp sensor 10, and the means for detecting the remaining amount of the recording medium original winding 2. Is connected to the control unit 9 which is a unit for controlling the heating temperature by the heating roller 31 and the pressure applied by the pressure roller 32 according to the detection result from the remaining amount sensor 11. 9
Degree of Warp of the Recording Medium 1 and the Recording Medium Main Roll 2
The heating temperature of the heating roller 31 and the pressure applied by the pressure roller 32 are appropriately controlled according to the remaining amount of winding.

The control of the heating temperature by the heating roller 31 is performed by the control section 9 controlling the electric power supplied to the heating element 31a inside the heating roller 31. As a result, the surface temperature of the heating roller 31 is maintained within an appropriate temperature range, and the warp of the recording medium 1 can be satisfactorily corrected. Specifically, 60 ℃
It is preferable that the temperature is in the range of 130 ° C. or higher to satisfactorily correct the warp of the recording medium, and 80 ° C. or higher and 100 ° C.
It is more preferable that the ratio is within the following range.

The control of the pressure applied by the pressure roller 32 is performed by the control unit 9 controlling the pressure applied to the pressure roller 32 by the pressure unit 32a. For example, the pressurizing unit 32a includes a spring 32b, an eccentric cam 32c, and the like, and the control unit 9
By controlling the rotational position of a drive motor (not shown) connected to the eccentric cam 32c, the pressing force of the spring 32b on the pressure roller 32 is controlled. As a result, the pressure applied by the pressure roller 32 to the recording medium 1 is appropriately controlled, and the warp of the recording medium 1 can be satisfactorily corrected.

FIG. 4 is applied correspondingly to a partially enlarged view of the vicinity of the heating roller 31 and the pressure roller 32. As described above, since the heating roller 31 is a metal roller and the pressure roller 32 is a rubber roller, the recording medium 1 conveyed while being sandwiched between them is
When emphasized and illustrated, the state shown in FIG. That is, the surface of the recording medium having a convex warp is set to the side of the heating roller 31 which is the metal roller and is conveyed between these rollers, whereby the recording medium 1 is forced to warp in the opposite direction. Therefore, it will be flattened. The effect of heating and pressurization is also added to this, so that the warp of the recording medium 1 is corrected more evenly.

The hardness difference between the heating roller 31 and the pressure roller 32 is preferably twice or more. The implementation result which is the basis thereof is the same as that in the case of the first embodiment.

The heating roller 31 and the pressure roller 32
When the hardness difference between the heating roller 31 and the pressure roller 32 is twice or more, the warp of the recording medium 1 is appropriately corrected. Therefore, it is preferable that the hardness difference between the heating roller 31 and the pressure roller 32 is two times or more. .

Therefore, the rubber material forming the pressure roller 32 has a hardness not more than half that of the metal material forming the heating roller 31 according to the hardness measuring method defined in JIS K-6253. It is preferable to use the same.

Further, the correction section 3 includes the heating roller 3
Since the recording medium 1 is composed of a pair of rollers, the pressure roller 32 and the pressure roller 32, it is preferable that the recording medium 1 is conveyed with its convex surface as the upper surface. This is
As shown in FIG. 5A, when the recording medium 1 is conveyed with the surface having the convex warp as the upper surface, the recording medium 1 relatively smoothly enters the correction section 3, while FIG. As shown in b), when the surface of the recording medium 1 having a convex warp is conveyed as the lower surface, the leading end of the recording medium 1 hits the correction section 3 and smoothly enters the correction section 3. It is impossible to do it. As described above, when the recording medium 1 is prevented from smoothly entering the correction portion 3, the recording surface of the recording medium 1 may be scratched, wrinkled, or the like. It is assumed that the convex surface is conveyed as the upper surface.

The holding section 4 is subordinate to the straightening section 3 and is provided at a position downstream of the straightening section 3 in the recording medium conveying direction. In order to maintain the flatness of the recording medium 1 that has been heated and pressed by the correction unit 3,
After the heat and pressure treatment, the flatness needs to be maintained until it is sufficiently cooled. Therefore, this is done by providing the holding portion 4. The holding portion 4 is formed flat by a sheet metal or the like, and the recording medium 1 is sandwiched from the upper and lower sides to straighten it.

The correction section 3 and the holding section 4 described above are
By providing the recording head 6 on the upstream side in the recording medium conveyance direction, the warp of the recording medium 1 is corrected before the recording by the recording head 6 is performed. As a result, good recording is performed by the recording head 6.

However, the correction section 3 and the holding section 4 are concerned.
May be provided at a position immediately before the sheet is discharged, that is, at the downstream side of the cutting unit 7 in the recording medium conveyance direction for the purpose of preventing the recording medium after the sheet from being warped. In reality, since the warp of the recording medium after the paper discharge is a very serious problem, such a form is also preferable.

Returning to FIG. 7, the description will be continued. The recording medium transporting section 5 includes a transporting roller 51 that is rotationally driven by a drive motor (not shown), and a driven roller 52 that is provided at a position facing the transporting roller 51.
The recording medium 1 is sandwiched between the conveying roller 21 and the driven roller 22, and the rotational driving of the conveying roller 21 allows the recording head 6 to be described later to record an image and the cutting unit 7 to cut the sheet. Accordingly, the recording medium 1 is configured to be conveyed by a predetermined amount in the right direction in the drawing.

The recording head 6 is constructed so as to be movable in the main scanning direction along a scanning guide (not shown) which is laid across the width direction of the recording medium 1 so as to be substantially orthogonal to the conveying direction of the recording medium 1. It is a reciprocating scanning type recording head. The recording head 6 has a plurality of ink tanks storing pigment inks of respective colors such as Y (yellow), M (magenta), C (cyan), and K (black), and performs main scanning along a scanning guide. While moving, by ejecting a predetermined ink at a predetermined timing according to the image data,
A predetermined image is recorded and formed on the recording surface of the recording medium 1 in cooperation with the conveyance of the recording medium 1 by the conveying unit 5.

The cutting unit 7 is, for example, the recording medium 1
A reciprocating scanning circular cutter configured to be movable in the main scanning direction along a scanning guide (not shown) that is installed across the width direction of the recording medium 1 so as to be substantially orthogonal to the conveyance direction of the recording medium 1. A controller 7 (not shown) cuts the recording medium 1 into a predetermined size. The cutting unit 7
The installation position of is not limited to this, for example,
It may be provided on the upstream side of the straightening unit 3 in the recording medium conveyance direction.

The recording medium 1 cut into a predetermined size by the cutting unit 7 is further conveyed to the fixing unit 12.

FIG. 9 shows an embodiment of the fixing unit 12. The fixing unit 12 is provided on the downstream side of the recording head 6 in the recording medium conveyance direction so as to perform a fixing process (heating and pressing process) on the recording medium 1 after the image is recorded and formed by the recording head 6. It is a thing. It is possible to use a fixing device that employs various fixing methods such as a roller fixing method and a belt fixing method that are already known in the fixing section. Therefore, in this embodiment, the roller fixing method is used. The fixing device will be taken as an example, and will be briefly described below.

As shown in the figure, the fixing section 12 mainly includes a heating roller 12a having a heating means, and a pressure roller 12b having a pressing means provided at a position facing the heating roller 12a. It consists of Heating roller 1
The reference numeral 2a includes a hollow metal roller, and a heating element 12c such as a halogen heater as a heat source is built in along the axial direction thereof. Then, the heating roller 31 is heated by the heat generated by the heating element 12c, and the ink absorption layer of the recording medium 1 pressed by the heating roller 31 is melted by the heat. The pressure roller 12b is made of a rubber roller, and the heating roller 12b
It has a pressing portion 12d composed of a spring or the like for pressing the pressing roller 12b toward a. And the pressurizing unit 1
The pressing roller 12b is pressed against the heating roller 12a by the pressing force of 2d to flatten the ink absorption layer of the recording medium 1 sandwiched between these rollers.

The recording medium 1 on which the fixing process of the ink absorbing layer has been performed by the fixing unit 12 is sufficiently cooled, and then,
The sheet is ejected to the outside of the inkjet recording apparatus, that is, to the sheet ejection tray.

Another example of the correction section 3 in the above [first embodiment] and [second embodiment] will be described below.

(Other Example 1) FIG. 10 shows another example of the correction section 3. As shown in the figure, the correction unit 3-1 in this example
Mainly includes a heating roller 31-1 having a heating means, a driven roller 32-1 driven by the heating roller 31-1,
A heating belt 33-1 suspended around these, a pressure roller 34-1 provided with a pressure means provided at a position facing the heating roller 31-1, and a position facing the heating belt 33-1. Pressure plate 35-1 having a pressurizing means
It consists of The heating roller 31-1 is composed of a hollow metal roller and has a heating element 31a-1 such as a halogen heater as a heat source built therein along the axial direction thereof. Then, the heating roller 31-1 and further the heating belt 33-1 are heated by the heat generation of the heating element 31a-1, and the warp of the recording medium 1 pressed by this is corrected by heat. The pressure roller 34-1 is made of a rubber roller, and is made of a spring or the like that presses the pressure roller 34-1 toward the heating roller 31-1.
have. Then, the pressure roller 34-1 is moved to the heating roller 31- by the pressing force of the pressure unit 34a-1.
The warp of the recording medium 1 nipped between these rollers is corrected by the pressure by pressing it toward the roller 1. Further, the pressing plate 35
-1 is made of a sheet metal member and has a pressing portion 35a-1 made of a spring or the like for pressing the pressing plate 35-1 toward the heating belt 33-1. Then, the pressurizing unit 35a-
The pressing plate 35-1 is pressed against the heating belt 33-1 by the pressing force of 1, and the warp of the recording medium 1 conveyed between them is corrected by the pressure. The pressing portion 35a-1 may be omitted as the pressing plate 35-1 is fixed at an appropriate position.

As described above, by configuring the straightening section by the belt system, the heating and pressurizing treatment can be performed for a sufficient time to straighten the warp of the recording medium. It can be corrected more flatly.

(Other Example 2) FIG. 11 shows still another example of the correction section 3. As shown in the figure, the correction unit 3-2 in this example mainly includes a heating roller 31-2 having a heating unit.
And the driven roller 32- driven by the heating roller 31-2.
2, a heating belt 33-2 suspended on these, a pressure roller 34-2 provided with a pressure means at a position facing the heating roller 31-2, and the pressure roller 34-2.
The driven roller 36-2 is driven by the driven roller 36-2, and the pressure belt 37-2 is suspended around the driven roller 36-2. The heating roller 31-2 is composed of a hollow metal roller and has a heating element 31a- such as a halogen heater which is a heat source along the axial direction thereof.
Built in 2. Then, the heating roller 31-2 and further the heating belt 33-2 are heated by the heat generation of the heating element 31a-2, and the warp of the recording medium 1 pressed by this is corrected by heat. In addition, the pressure roller 3
4-2 is a pressure unit 34a-2 including a spring or the like that presses the pressure roller 34-2 toward the heating roller 31-2.
The pressing roller 34-2 is pressed against the heating roller 31-2 by the pressing force of the pressing portion 34a-2, and the warp of the recording medium 1 sandwiched between these rollers is pressed by the pressure. to correct. Further, the pressure belt 37-2 is
The recording medium 1 is pressed against the heating belt 33-2 by the tension or a pressing means (not shown), and the warp of the recording medium 1 conveyed between them is corrected by the pressure.

As described above, by configuring the straightening section by the belt system, the heating and pressurizing treatment can be performed for a sufficient time to straighten the warp of the recording medium, so that the warp of the recording medium can be prevented. It can be corrected more flatly.

(Other Example 3) FIG. 12 shows still another example of the correction section 3. As shown in the figure, the straightening unit 3-3 in this example is mainly composed of a heating / pressurizing roller 31-3 having a heating means and a pressing means, and a driven roller driven by the heating / pressurizing roller 31-3. 32-3, a heating / pressurizing belt 33-3 suspended thereon, and a drum roller 38-3 provided at a position facing the heating / pressurizing belt 33-3. The heating / pressurizing roller 31-3 is made of a hollow metal roller and has a heating element 31a-3 such as a halogen heater as a heat source built therein along the axial direction thereof. Then, the heat and pressure roller 31-3 and further the heat and pressure belt 33-3 are generated by the heat generated by the heating element 31a-3.
Is heated, and the warp of the recording medium 1 pressed by this is corrected by heat and pressure. The heating / pressurizing roller 31-3 is a pressing unit 3 including a spring or the like that presses the heating / pressurizing roller 31-3 toward the drum roller 38-3.
1b-3, the heating and pressing roller 31-3 is moved by the pressing force of the pressing portion 31b-3 to the drum roller 38-.
3, the warp of the recording medium 1 nipped between these rollers is corrected by the pressure. Further, the heating / pressurizing belt 33-3 presses the recording medium 1 against the drum belt 38-3 by its tension or pressing means not shown, and presses the warp of the recording medium 1 conveyed between them. Correct by

As described above, the correction unit is composed of the belt and the drum roller, and the curvature of the drum roller is used to correct the warp of the recording medium, thereby simplifying the structure of the correction unit. In addition, the heating and pressure treatment can be performed for a sufficient time to correct the warp of the recording medium. Therefore, the manufacturing cost is reduced and
The warp of the recording medium can be corrected more evenly.

(Other Example 4) FIG. 13 shows still another example of the correction section 3. As shown in the figure, the correction unit 3-4 in this example mainly includes a pressure roller 34-4 having a pressure unit.
And the driven roller 32-, which is driven by the pressure roller 34-4.
4, a pressure belt 33-4 suspended on these, and a drum roller 38-4 having a heating means provided at a position facing the pressure belt 33-4.
The drum roller 38-4 is made of a hollow metal roller and has a heating element 38a-4 such as a halogen heater as a heat source built therein along the axial direction thereof. And the heating element 3
The drum roller 38-4 is heated by the heat generated by 8a-4, and the warp of the recording medium 1 pressed by the drum roller 38-4 is corrected by the heat. Further, the pressure roller 34-4 moves toward the drum roller 38-4.
4 has a pressurizing portion 34a-4 composed of a spring or the like for pressing 4,
The pressing roller 3 is pressed by the pressing force of the pressing portion 34a-4.
4-4 is pressed against the drum roller 38-4, and the warp of the recording medium 1 sandwiched between these rollers is corrected by the pressure. Further, the pressure belt 33-4 presses the recording medium 1 against the drum belt 38-4 by its tension or pressing means not shown, and presses the warp of the recording medium 1 conveyed between them. Correct by

As described above, the correction unit is configured by the belt and the drum roller, and the curvature of the drum roller is used to correct the warp of the recording medium, thereby simplifying the structure of the correction unit. In addition, the heating and pressure treatment can be performed for a sufficient time to correct the warp of the recording medium. Therefore, the manufacturing cost is reduced and
The warp of the recording medium can be corrected more evenly.

Incidentally, the correction units 3-1 to 3-4 described above.
Also in this case, the heating temperature and the pressurizing pressure are controlled in the same manner as the correction unit 3 described above. Further, also in the correction units 3-1 to 3-4, the guide 4 is provided downstream of the recording medium conveyance direction.

The ink jet recording medium preferably used in the present invention will be described in detail below.

An ink jet recording medium may be image-printed with a water-based ink or may absorb moisture or swell to form a curl depending on the humidity in the atmosphere. In addition, the ink jet recording medium provided in the form of a roll may have a curl that is forced in advance.

The curl value in the present invention is measured by the following method.

<Curl value> Recording medium is 20 cm × 20 c
The size of m is left for 2 hours in an environment of 23 ° C./50% RH, then placed on a horizontal table, and the average value of the lifting amount of the four corners is taken as the curl value. At this time, a curl with the ink absorption layer on the inner side was a positive value, and a curl with the ink absorption layer on the outer side was a negative value.

In order to evaluate the curl characteristics of the ink jet recording medium, the following treatments and measurements are carried out.

<Method of setting initial curl> A cylindrical object having a diameter of 6 cm is wound around the recording medium so that the ink absorption layer of the recording medium is on the outside, and this is wound in a thermostatic chamber at 40 to 50 ° C. for several hours.
Leave it for about half a day and add a curl habit. The standing time is set so that the curl value is −30 to −40 mm.

<Heating, Pressurizing Device and Processing Method> Diameter 30
mm columnar iron cylinder (upper roller) and silicon rubber roller (lower roller with a diameter of 30 mm) are both covered with a tetrafluoroethylene-perfluoroalkyl ether copolymer, and a fixing device having a heater built in the iron cylinder. The recording medium is inserted so that the upper roller is in contact with the surface of the ink absorbing layer, and the nip width is 0.3 mm and the linear pressure is 2 mm.
Simultaneous heating and pressurization is performed under the condition of 32 kgf for a width of 97 mm. The transport speed at this time is 10 mm / s. Further, the surface temperature of the upper roller is adjusted to 120 ° C. The coating thickness of the tetrafluoroethylene-perfluoroalkyl ether copolymer with which the iron roller is coated is 100 μm.

By the above method, the ink jet recording medium of the present invention can be specified.

In the ink jet recording medium of the present invention, the mass ratio of the inorganic pigment to the water-soluble binder is 3: 1 to.
It is preferably 9: 1.

Examples of the inorganic pigment used for the above purpose include light calcium carbonate, heavy calcium carbonate,
Magnesium carbonate, kaolin, clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc hydroxide, zinc sulfide, zinc carbonate, hydrotalcite,
Aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica,
Examples thereof include white inorganic pigments such as alumina, colloidal alumina, pseudo-boehmite, aluminum hydroxide, lithopone, zeolite and magnesium hydroxide.

As the inorganic pigment, it is particularly preferable to use solid fine particles selected from silica and alumina or alumina hydrate.

As silica that can be used in the present invention, silica synthesized by a usual wet method, colloidal silica, silica synthesized by a vapor phase method and the like are preferably used, and particularly preferable fine particle silica is used. , Colloidal silica or fine particle silica synthesized by a vapor phase method, and among them, fine particle silica synthesized by a vapor phase method is a cationic polymer used not only for obtaining a high porosity but also for fixing a dye. It is preferable that coarse aggregates are not easily formed when added to. Alumina or alumina hydrate may be crystalline or amorphous, and also has amorphous particles, spherical particles,
Any shape such as acicular particles can be used.

The inorganic pigment is preferably in a state in which the fine particle dispersion liquid before mixing with the cationic polymer is dispersed up to the primary particles.

The particle size of the inorganic pigment is preferably 100 nm or less. For example, in the case of the gas phase method fine particle silica, the average particle diameter of the primary particles of the inorganic pigment dispersed in the state of primary particles (particle diameter in the dispersion state before coating) is 10
It is preferably 0 nm or less, more preferably 4 to 50.
nm, most preferably 4 to 20 nm.

As the most preferably used silica synthesized by the vapor phase method having an average primary particle diameter of 4 to 20 nm, for example, Aerosil manufactured by Nippon Aerosil Co., Ltd. is commercially available. This gas phase method fine particle silica is in water,
For example, the primary particles can be dispersed relatively easily by suction dispersion using a jet stream inductor mixer manufactured by Mitamura Riken Kogyo Co., Ltd.

Examples of the water-soluble binder that can be used in the present invention include polyvinyl alcohol, gelatin, polyethylene oxide, polyvinylpyrrolidone,
Polyacrylic acid, polyacrylamide, polyurethane,
Dextran, dextrin, agar, pullulan, water-soluble polyvinyl butyral, hydroxyethyl cellulose,
Examples include carboxymethyl cellulose and the like. It is also possible to use two or more of these water-soluble binders in combination.

The water-soluble binder preferably used in the present invention is polyvinyl alcohol.

Polyvinyl alcohol includes not only ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, but also modified polyvinyl alcohol such as cation-modified polyvinyl alcohol having terminals and anion-modified polyvinyl alcohol having an anionic group. Be done.

The polyvinyl alcohol obtained by hydrolyzing vinyl acetate preferably has an average degree of polymerization of 1,000 or more, and particularly preferably an average degree of polymerization of 1,500 to.
Those of 5,000 are preferably used. The saponification degree is preferably 70 to 100%, and 80 to 99.5.
% Is particularly preferable.

Examples of the cation-modified polyvinyl alcohol include primary to tertiary amino groups and quaternary ammonium groups as described in JP-A-61-10483 in the main chain or side chain of the polyvinyl alcohol. Which 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-acrylamido-2,2-dimethylethyl) ammonium chloride and trimethyl (3-acrylamido-3,3-dimethylpropyl) ammonium. Chloride, N-vinylimidazole, N-vinyl-2-methylimidazole, N-
(3-dimethylaminopropyl) methacrylamide, hydroxylethyltrimethylammonium chloride,
Examples thereof include trimethyl (2-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 anion-modified polyvinyl alcohol is, for example, polyvinyl alcohol having an anionic group as described in JP-A No. 1-206088, JP-A-6-61.
Copolymers of vinyl alcohol and a vinyl compound having a water-soluble group, as described in JP-A Nos. 1-237681 and 63-307979, and JP-A-7-2852.
And modified polyvinyl alcohol having a water-soluble group as described in No. 65.

As the nonion-modified polyvinyl alcohol, for example, a polyvinyl alcohol derivative obtained by adding a polyalkylene oxide group to a part of vinyl alcohol as described in JP-A-7-9758, and JP-A-8-25795. Examples thereof include block copolymers of the described vinyl compounds having a hydrophobic group and vinyl alcohol. Polyvinyl alcohol can be used in combination of two or more types such as different degree of polymerization or modification.

Oil droplets made of a hydrophobic organic compound having a melting point of 40 ° C. or lower can be used in the ink jet recording medium of the present invention. Usually, the solubility in water at room temperature is 0.
It is 1% by mass or less, particularly preferably 0.01% by mass or less and a hydrophobic organic compound having a melting point of 40 ° C. or less. Examples of such a hydrophobic organic compound include an organic compound generally known as a hydrophobic high boiling point organic solvent and a hydrophobic polymer having a melting point of 40 ° C. or lower.

For example, phthalic acid esters (dibutyl phthalate, dioctyl phthalate, diisodecyl phthalate, etc.), phosphoric acid esters (tricresyl phosphate, trioctyl phosphate, etc.), fatty acid esters (butyl stearate, bis sebacate bis ( 2-ethylhexyl), ethylene glycol distearate, glycerol tributyrate, etc.), amides (N, N-diethyllaurylamide, N, N-diethyl-2- (2,5)
-Di-t-amylphenoxy) butanamide etc.), ethers (ethylene glycol dibutyl ether, decyl ether, dibenzyl ether etc.), silicone oil and liquid paraffin.

The emulsion resin according to the present invention having Tg of 20 ° C. or lower and polyvinyl alcohol as a dispersant will be described. Polyvinyl alcohol used as a dispersant is, in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, cation-modified polyvinyl alcohol and anion-modified polyvinyl alcohol having an anionic group such as a carboxyl group, silyl. Modified polyvinyl alcohol such as silyl modified polyvinyl alcohol having a group is also included. The average degree of polymerization of polyvinyl alcohol is preferably 300 to 5,000, and the degree of saponification is preferably 70 to 100 mol%.

Examples of the resin emulsion-polymerized with polyvinyl alcohol include homopolymers or copolymers of ethylene monomers such as acrylic acid esters, methacrylic acid esters, vinyl compounds and styrene compounds, and diene compounds such as butadiene and isoprene. Examples of the combination include acrylic resins, styrene-butadiene resins, ethylene-vinyl acetate resins, and the like.

These emulsion resins impart flexibility during formation of the void layer, and those having flexibility even at room temperature are suitable. More preferably, they are fused at room temperature to form the layer. Therefore, at this time, Tg when the emulsion resin is formed into a film is preferably 20 ° C. or lower, and more preferably −40 to 10 ° C.

Examples of the thermoplastic resin according to the present invention include polycarbonate, polyacrylonitrile, polystyrene, polyacrylic acid, polymethacrylic acid, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyester, polyamide and polyether. And copolymers thereof. Among them, styrene-acrylic acid ester copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-acrylic acid ester copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, SBR latex preferable.

The thermoplastic resin may be a mixture of a plurality of polymers having different monomer compositions, particle sizes, and degrees of polymerization.

In selecting the thermoplastic resin, the ink absorbency, the glossiness of the image after fixing by heating and pressurization,
Image fastness and releasability should be considered.

Regarding the ink absorbability, when the particle size of the thermoplastic resin is less than 0.05 μm, the separation of the pigment particles and the ink solvent in the pigment ink becomes slow, and the ink absorption speed is lowered. On the other hand, if it exceeds 10 μm, it is not preferable from the viewpoint of film strength and gloss deterioration of the inkjet recording medium after coating and drying. For this reason, the preferable thermoplastic resin diameter is preferably 0.05 to 10 μm,
More preferably, it is 0.1 to 5 μm. More preferably, it is 0.1 to 1 μm.

As a criterion for selecting the thermoplastic resin, the glass transition point (Tg) can be mentioned. When Tg is lower than the coating drying temperature, for example, the coating drying temperature at the time of manufacturing the recording medium is already higher than Tg, and the voids for the ink solvent to pass through are lost by the thermoplastic resin. See also T
If g is higher than the temperature at which the support is denatured by heat, a fixing operation at a high temperature is required in order to melt and form a film after ink jet recording with a pigment ink. Thermal stability etc. becomes a problem. The preferable Tg of the thermoplastic resin is 50 to 150 ° C.

As the minimum film forming temperature (MFT),
It is preferably 50 to 150 ° C. The thermoplastic resin is preferably dispersed in an aqueous system from the viewpoint of environmental suitability,
In particular, an aqueous latex obtained by emulsion polymerization is preferable. At this time, the type obtained by emulsion polymerization using a nonionic dispersant as an emulsifier is a form that can be preferably used. From the viewpoint of odor and safety, the thermoplastic resin used preferably has a small amount of residual monomer components, is preferably 3% by mass or less, and more preferably 1% by mass or less, based on the solid content of the polymer. Preferably 0.
It is 1 mass% or less.

The solid content of the thermoplastic resin contained in the surface layer is preferably ² g / m ² or more and 20 g / m ² or less, more preferably ^{2 to} 15 g / m ² .
More preferably, it is in the range of 2.5 to 10 g / m ² . If the solid content of the thermoplastic resin is too small, a sufficient film cannot be formed and the pigment cannot be sufficiently dispersed in the film. Therefore, the image quality and gloss are not sufficiently improved. Also,
When the solid content of the thermoplastic resin is too large, the thermoplastic resin cannot be completely formed into a film in a short heating step, and the fine particles remain as opaqueness, which deteriorates the image quality. In addition, the ink absorption speed is also reduced, causing bleeding at the boundary, which is a problem.

The surface layer having the thermoplastic resin in the present invention is not limited to the outermost surface layer. An outermost layer may be provided on the surface layer for surface protection or other purposes. In the inkjet recording paper of the present invention, it is preferable that the thermoplastic resin contained in the surface layer be melted and formed into a film after image recording, for example, by heating. For example, when printing with dye ink, light resistance or water resistance can be improved by applying heat treatment after image recording.

In the case of printing with pigment ink, heat treatment is applied after image recording to improve image quality, for example, glossiness, abrasion resistance, and degree of bronzing. it can.

The curing agent that can be used in the present invention is not particularly limited as long as it causes a curing reaction with a water-soluble binder, but boric acid and salts thereof are preferable, and other known ones can be used. Generally, it is a compound having a group capable of reacting with a water-soluble binder or a compound that promotes a reaction between different groups of the water-soluble binder, and is appropriately selected and used according to the type of the water-soluble binder. .

Specific examples of the curing agent include epoxy type curing agents (diglycidyl ethyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-diglycidyl cyclohexane, N, N-). Diglycidyl-4-glycidyloxyaniline, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, etc.), aldehyde type curing agents (formaldehyde, glyoxal, etc.), active halogen type curing agents (2,4-dichloro-6-hydroxy-)
1,3,5-s-triazine, etc.), active vinyl compounds (1,3,5-trisacryloyl-6H-s-triazine, bisvinylsulfonylmethyl ether, etc.), aluminum alum and the like.

The boric acid or a salt thereof means an oxyacid having a boron atom as a central atom and a salt thereof, and specifically, orthoboric acid, diboric acid, metaboric acid, tetraboric acid,
Pentaboric acid and octaboric acid and their salts are mentioned. Boric acid having a boron atom and a salt thereof as a curing agent may be used as a single aqueous solution or as a mixture of two or more kinds. Particularly preferred is a mixed aqueous solution of boric acid and borax. The aqueous solutions of boric acid and borax can be added only in relatively dilute aqueous solutions, but by mixing them, a concentrated aqueous solution can be obtained and the coating solution can be concentrated. In addition, p of the aqueous solution to be added
There is an advantage that H can be controlled relatively freely.

In the ink jet recording medium of the present invention, a cationic polymer is preferably used for the purpose of preventing image bleeding due to storage after recording.

Examples of the cationic polymer include polyethyleneimine, polyallylamine, polyvinylamine,
Dicyandiamide polyalkylene polyamine condensate, polyalkylene polyamine dicyandiamide ammonium salt condensate, dicyandiamide formalin condensate, epichlorohydrin / dialkylamine addition polymer, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride / SO ₂ copolymer, polyvinylimidazole, Vinylpyrrolidone / vinylimidazole copolymer, polyvinylpyridine, polyamidine, chitosan, cationized starch, vinylbenzyltrimethylammonium chloride polymer, (2-methacryloyloxyethyl) trimethylammonium chloride polymer,
Examples thereof include dimethylaminoethyl methacrylate polymer.

The support according to the present invention may be any of those conventionally used for ink jet recording media, for example, paper support such as plain paper, art paper, coated paper and cast coated paper, plastic support, both sides. A paper support coated with polyolefin, a composite support obtained by laminating these, and the like can be appropriately selected and used.

In the ink jet recording medium of the present invention, for the purpose of increasing the adhesive strength between the support and the ink absorbing layer,
Prior to applying the ink absorbing layer, it is preferable to subject the support to corona discharge treatment, subbing treatment, or the like. Further, the recording medium of the present invention does not necessarily have to be colorless, and may be colored recording paper.

In the ink jet recording medium of the present invention, the use of a paper support in which both sides of the base paper support are laminated with polyethylene or the like allows a recorded image to be close to a photographic quality, and a high quality image can be obtained at low cost. , Particularly preferred. A paper support laminated with such polyethylene will be described below.

The base paper used for the paper support is mainly made of wood pulp, and if necessary, synthetic paper such as polypropylene or synthetic fiber such as nylon or polyester is used in addition to wood pulp. As wood pulp, LBKP, LBSP, NBKP, NBSP,
Any of LDP, NDP, LUKP, and NUKP can be used, but LBKP, NBSP, which has a large amount of short fibers,
It is preferable to use more LBSP, NDP, and LDP. However, the ratio of LBSP and / or LDP is 1
0 mass% or more and 70 mass% or less are preferable.

As the above pulp, a chemical pulp containing few impurities (sulfate pulp or sulfite pulp) is preferably used, and a pulp whose whiteness is improved by bleaching is also useful. The base paper contains sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength enhancers such as starch, polyacrylamide and polyvinyl alcohol, optical brighteners and polyethylene glycols. A water retention agent such as, a dispersant, and a softening agent such as quaternary ammonium can be appropriately added.

If desired, various additives may be incorporated into any layer on the ink absorbing layer side of the ink jet recording paper of the present invention.

For example, JP-A-57-74193 and JP-A-5-74193.
UV absorbers described in JP-A Nos. 7-87988 and 62-261476, JP-A-57-74192 and 57-8.
7989, 60-72785, 61-1465.
91, JP-A-1-95091 and JP-A-3-13376.
Anti-fading agents, various anionic, cationic or nonionic surfactants described in JP-A-59-429.
No. 93, No. 59-52689, No. 62-280069.
No. 61-242871, and JP-A-4-2192.
66, etc., optical brighteners, sulfuric acid, phosphoric acid,
Acetic acid, citric acid, sodium hydroxide, potassium hydroxide,
Various known additives such as a pH adjusting agent such as potassium carbonate, an antifoaming agent, a lubricant such as diethylene glycol, an antiseptic, a thickener, an antistatic agent, a matting agent and the like may be contained.

In the present invention, the effect is more exerted when the roll-shaped recording medium is used. The roll-shaped recording medium referred to here means a long recording medium wound around a core. The diameter (outer diameter) of the core core is not particularly limited, but the diameter of the core core is preferably 10 cm or less so that the entire apparatus does not become too large. More preferably 1
It is 0 cm or less and 2 cm or more. The roll width is not particularly limited, but can be selected in the range of 5 to 120 cm.
Also, the length of the roll-shaped recording medium is not particularly limited,
It can be selected in the range of 5 to 200 m.

Next, a method for manufacturing the ink jet recording medium of the present invention will be described.

As a method for producing the ink jet recording medium, each of the constituent layers including the ink absorbing layer is individually or simultaneously selected from the well-known coating methods, coated on a support and dried. You can As the coating method, for example, roll coating method, rod bar coating method, air knife coating method, spray coating method, curtain coating method, or US Pat.
The slide bead coating method using the hopper described in Nos. 761,419 and 2,761,791, the extrusion coating method and the like are preferably used.

When the slide bead coating method is used, the viscosity of each coating solution at the time of simultaneous multi-layer coating is 5
The range is preferably from 100 to 100 mPa · s, more preferably from 10 to 50 mPa · s. When using the curtain coating method, the range of 5 to 1200 mPa · s is preferable, and more preferably 25 to 500 mPa · s.
Is the range.

The viscosity of the coating liquid at 15 ° C. is preferably 100 mPa · s or more, and 100 to 30,
000 mPa · s is more preferable, and even more preferably 3,
000 to 30,000 mPa · s, and most preferably 10,000 to 30,000 mPa · s.

As a coating and drying method, the coating liquid is 3 times.
It is preferable that after the simultaneous multilayer coating is performed by heating to 0 ° C. or higher, the temperature of the formed coating film is once cooled to 1 to 15 ° C. and dried at 10 ° C. or higher. During preparation of the coating solution, during coating and during drying, it is preferable to prepare, coat and dry the coating solution at a temperature not higher than Tg of the thermoplastic resin so that the thermoplastic resin contained in the surface layer does not form a film. More preferably,
As the drying conditions, a wet bulb temperature of 5 to 50 ° C. and a film surface temperature of 10
It is carried out under the condition of a temperature range of 50 ° C. In addition, as a cooling method immediately after coating, it is preferable to use a horizontal setting method from the viewpoint of uniformity of the formed coating film.

In the manufacturing process, the temperature is 35 ° C. or higher and 70 ° C.
It is preferable to have a step of storing for 24 hours or more and 60 days or less under the following conditions.

The heating condition is not particularly limited as long as it is stored at 35 ° C. or higher and 70 ° C. or lower for 24 hours or longer and 60 days or shorter, but a preferable example is, for example, 36 ° C.
3 days to 4 weeks, 40 ° C for 2 days to 2 weeks, or 55
1 to 7 days at ° C. By applying this heat treatment,
The curing reaction of the water-soluble binder or the crystallization of the water-soluble binder can be promoted, and as a result, preferable ink absorbency can be achieved.

When an image is recorded using the ink jet recording medium of the present invention, a recording method using an aqueous ink is preferably used, and the aqueous ink may be an aqueous dye ink or an aqueous pigment ink. . The aqueous dye ink or the aqueous pigment ink is a recording liquid containing the following colorant, liquid medium, and other additives.

As the colorant, there are known water-soluble dyes such as direct dyes, acid dyes, basic dyes, reactive dyes and food dyes known in ink jet, organic pigments such as azo pigments, phthalocyanine pigments and dye lakes, and carbon. An aqueous pigment such as an inorganic pigment such as black can be used.

Examples of other water-based ink additives include water-soluble organic solvents (propanol, hexanol, ethylene glycol, diethylene glycol, glycerin, hexanediol, urea, etc.), surfactants, water-soluble polymers, preservatives and mildew-proofing agents. Agents, viscosity adjusting agents, pH adjusting agents and the like.

[0173]

The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In addition, the% display described in the examples represents mass% unless otherwise specified.

Example 1 << Preparation of Silica Dispersion-1 >> Vapor phase method silica having an average primary particle size of about 0.012 μm (manufactured by Tokuyama Corporation:
QS-20) 125 kg was suction-dispersed at room temperature in 620 L of pure water whose pH was adjusted to 2.5 with nitric acid using a jet stream inductor mixer TDS manufactured by Mitamura Riken Kogyo Co., Ltd. Then, the total amount was adjusted to 694 L to prepare a silica dispersion liquid-1.

<< Preparation of Silica Dispersion Liquid-2 >> 1.14 kg of the cationic polymer (P-1), 2.2 L of ethanol,
Aqueous solution containing 1.5 L of n-propanol (pH =
2.3) 69.4 L of the above silica dispersion liquid-1 in 18 L
Was added with stirring, and then 7.0 L of an aqueous solution containing 260 g of boric acid and 230 g of borax was added.
1 g of N381 (manufactured by San Nopco Ltd.) was added. This mixed liquid was dispersed with a high pressure homogenizer manufactured by Sanwa Kogyo Co., Ltd., and the total amount was adjusted to 97 L with pure water to prepare a silica dispersion liquid-2.

<< Preparation of Oil Drops >> 20 g of diisodecyl phthalate (mp = −53 ° C.) and antioxidant (AO-1) 2
0 g and 45 g of ethyl acetate were dissolved by heating, 210 ml of an aqueous gelatin solution containing 8 g of acid-treated gelatin, 2.9 g of cationic polymer (P-1) and 10.5 g of saponin (produced by Eastman Chemical Co.) and 55 ° C. After mixing and emulsifying with a high-pressure homogenizer, the total amount was adjusted to 300 ml with pure water to prepare oil droplets.

[0177]

[Chemical 1] << Synthesis of Emulsion Resin >> 5% polyvinyl alcohol aqueous solution (polymerization degree 1700, saponification degree 88.5 mol%) 4
Adjust the pH of 00g to 3.5 and add 50g of methyl methacrylate and 50g of butyl acrylate while stirring to 60g.
The temperature was raised to 0 ° C., and 10 g of a 5% ammonium persulfate aqueous solution was added to initiate polymerization. After 15 minutes, 100 g of butyl methacrylate and 100 g of butyl acrylate were gradually added over 3 hours, and after 5 hours, the mixture was cooled when the polymerization rate reached 99.9%. This was neutralized to pH 7.0 to synthesize an emulsion resin.

The emulsion resin was dried at 60 ° C. in a vacuum drier and the Tg was measured by a differential scanning calorimeter, it was 5 ° C.

<< Preparation of coating liquid-1 >> The following coating liquid-1 was prepared using the silica dispersion liquid-2 prepared above.

While stirring 600 ml of the silica dispersion liquid-2 at 40 ° C., 130 ml of a 10% aqueous solution of polyvinyl alcohol (Kuraray Industries Co., Ltd .: PVA235) was added, and the total amount was made up to 1000 ml with pure water. 1
And

<< Preparation of Coating Solutions-2 to 4 >> 130 ml of 10% polyvinyl alcohol to be added to Coating Solution-1
Coating liquids-2 to 4 were prepared in the same manner as coating liquid-1, except that the amounts were changed to 10 ml, 95 ml, and 195 ml.

<< Preparation of coating liquid-5 >> Coating liquid-2 except that 30 ml of the oil droplets prepared above was further added to coating liquid-2.
A coating liquid-5 was prepared in the same manner as in.

<< Preparation of Coating Liquid-6 >> The above silica dispersion liquid
While stirring 600 ml of 2 at 40 ° C., 1 part of polyvinyl alcohol (Kuraray Industry Co., Ltd .: PVA235)
100 ml of 0% aqueous solution was added, and further 6.0 g of the synthetic emulsion resin was added, and the total amount was 1000 ml with pure water.
To give coating liquid-6.

<< Coating Liquid Mixing Silica and Thermoplastic Resin-1
Preparation >> A styrene-acrylic latex polymer (Tg 78 ° C., average particle size 0.2 μm, solid content concentration 50%) obtained by emulsion polymerization using 1,600 ml of the above-mentioned coating solution-1 using an aqueous solution of polyvinyl alcohol as an emulsifier is a thermoplastic resin. The pH was adjusted to 4.7 with a 6% aqueous nitric acid solution so that the mass ratio of silica to the thermoplastic resin was 1: 1,
The mixture was added and mixed at 0 ° C with stirring. The total amount of this was adjusted to 1000 ml with pure water to prepare a mixed coating liquid-1 of silica and a thermoplastic resin.

<< Coating Liquid Mixing Silica and Thermoplastic Resin-2
Preparation> The coating solution-2 of silica and thermoplastic resin was prepared in the same manner as the coating solution-1 of silica and thermoplastic resin, except that the coating solution-5 was used.

[Preparation of Inkjet Recording Medium-1] As a support, polyethylene-coated paper in which both sides of a base paper having a basis weight of 170 g / m ² are coated with polyethylene (8% by mass of anatase in the polyethylene layer on the ink absorption layer side) Type titanium oxide is contained, and 0.05g on the ink absorption layer surface side
/ M ² gelatin subbing layer is provided, and Tg is provided on the opposite side.
Was provided with a back layer containing 0.2 g / m ² of latex polymer having a temperature of about 80 ° C. The coating liquid-1 prepared above was applied from the polyethylene coated surface side of 10) to a wet film thickness of 200 μm, and once cooled to about 7 ° C., 20 to 6
A warm air of 5 ° C. was blown and dried to prepare an inkjet recording medium-1 of the invention.

[Preparation of Inkjet Recording Medium-2 to 6] Inkjet recording medium 2 of the present invention was prepared in the same manner as inkjet recording medium-1 using coating liquids-2 to 6.
~ 6 were produced.

[Preparation of Inkjet Recording Medium-7] Onto the inkjet recording medium-1, the mixed coating liquid-1 of silica and thermoplastic resin prepared above was wet-thickness 50 μm.
It is coated so that it becomes m and cooled once to about 7 ℃, then 20
It was dried by blowing warm air of ˜65 ° C. to prepare an inkjet recording medium-7 of the invention.

[Preparation of Inkjet Recording Medium-8] Except that the above-prepared mixed coating solution of silica and thermoplastic resin-2 was applied onto Inkjet recording medium-2.
An inkjet recording medium-8 of the present invention was produced in the same manner as the inkjet recording medium-7.

[Preparation of Inkjet Recording Medium-9] Except that the above-prepared mixed coating solution of silica and thermoplastic resin-1 was applied onto Inkjet recording medium-3.
Inkjet recording medium-9 of the invention was prepared in the same manner as inkjet recording medium-7.

[Preparation of Inkjet Recording Medium-10]
An inkjet recording medium-10 of the present invention was prepared in the same manner as the inkjet recording medium-7 except that the mixed coating liquid-1 of silica and thermoplastic resin prepared above was applied onto the inkjet recording medium-6. did.

[Preparation of Inkjet Recording Medium-11]
An inkjet recording medium-11 of the present invention was prepared in the same manner as the inkjet recording medium-7 except that the mixed coating solution-2 of silica and thermoplastic resin prepared above was applied onto the inkjet recording medium-6. did.

[Preparation of Inkjet Recording Medium-12]
In the preparation of the silica dispersion liquid-2, the silica dispersion liquid-1,
Dispersion liquid 3 in which 69.4L of silica was not added was prepared, and coating liquid 7 was prepared in the same manner as coating liquid-1. An inkjet recording medium-12 was prepared in the same manner as the inkjet recording medium-1 except that the coating liquid 7 was used.

<< Measurement of Curl >><Applying and measuring initial curl> A recording medium was set to 20 cm × 20.
It was cut into a size of cm and wound around a cylindrical object having a diameter of 6 cm so that the ink absorbing layer of the recording medium was on the outside, and this was left in a thermostatic chamber at 40 ° C. to 50 ° C. for several hours to half a day. . Curling value is -30 to -40 mm
So that Remove from cylinder, 23 ℃, 50
After being left for 2 hours in an environment of% RH, it was placed on a horizontal table and the average value of the lifted amount of the four corners was taken.

<Measurement of curl after heating and pressurizing> Each sample having the initial curl value shown in Table 1 was treated with the above heating and pressurizing device (120 ° C., 3 for a width of 297 mm linear pressure).
The curl value after applying 2 kgf) was similarly measured.

The measurement results are shown in Table 1.

[0197]

[Table 1]

<Evaluation> Further, Table 2 shows evaluations relating to fluctuations in curl (warpage) and occurrence of cracks depending on environmental conditions. The details will be described below.

<Variation of curl due to environmental conditions> Each of the recording media was cut into 20 × 20 cm square pieces,
The cut sample obtained is from 10 hours to 2 hours for several hours to half a day.
It was left in an environment of 0% RH. Then, the cut samples were placed on a horizontal plane, and the average distance L1 (mm) at which the four corners of the cut sample were separated from the horizontal plane was measured. The upward warp from the horizontal plane was measured as +, and the warp in the opposite direction was measured as-. At the same time, each of the cut samples was left in an environment of 30 ° C. and 80% RH, and the average distance of the four corners from the horizontal plane was set to L2 (mm). The difference L1-L2 (mm) between the average distances is shown as the difference in warpage due to the environmental conditions in Table 2.

<Generation of cracks on the surface> Each of the storage media (samples) prepared as described above was installed in a large inkjet printer IGUAZU1440 (manufactured by Konica) to prepare a color image, and the image was recorded on the recording medium. did. The recording medium on which the image was recorded was subjected to a linear pressure of 32 kgf at a temperature of 120 ° C. and a width of 297 mm with a heating and pressure treatment device. After that, the sample was held at 40 ° C for 8 months in January.
It was stored in an environment of 0% RH and the state of crack generation on its surface was observed. Table 2 shows the observation results classified by the following symbols. A: No crack was generated. B: The number of cracks is 5 or less within 20 × 20 cm. C: The number of cracks in 20 × 20 cm is 5 or more and 10 or less. D: The number of cracks is 20 or more in 20 × 20 cm.

[0201]

[Table 2]

Generally, when the environmental conditions, especially the humidity and the temperature are changed, the warp of the recording medium recorded by ink jet is
It tends to be due to varying degrees of expansion or contraction of the binder, or other ingredients, within the medium. However,
The warp of the inkjet recording medium of the present invention showed a relatively low change. More particularly, in general, when stored at high temperature and high humidity, the ink layer of the recording medium absorbs water and expands,
On the other hand, the surface of the recording medium dries to form a film. Therefore, cracks are likely to occur due to distortions inside and outside the recording medium. However, the recording medium according to the present invention has relatively few cracks.

Example 2 With the ink jet recording medium-7 prepared in Example 1, a sample having a width of 297 mm and a length of 20 m after coating was used as a core of a core having a diameter of 7.6 cm and the ink absorbing layer was on the outside. Wrapped around. This was attached to a large format inkjet printer IGUAZU1440 (manufactured by Konica) to produce a color image. This image was heated by the heating / pressurizing device used in Example 1 at 120 ° C. and a linear pressure of 297 mm at 32.
It was processed under the conditions of kgf. An ink jet print with no curl was obtained.

[0204]

As described above, according to the ink jet recording method and the ink jet recording apparatus of the present invention, the heating and pressurizing treatment is appropriately performed according to the characteristics of the recording medium, the degree of warpage, the remaining amount of winding, and the like. As a result, since the warp of the recording medium can be corrected flat, it is possible to realize high-quality image printing without the recording head and the recording medium coming into contact with each other. In addition, it is possible to create an image print without warpage.

According to the present invention, an ink jet recording medium having excellent flatness and an image forming method using the same can be provided.

[0206]

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an inkjet recording apparatus according to claim 1 of the present invention.

FIG. 2 is a schematic configuration diagram showing another example of the inkjet recording apparatus shown in FIG.

FIG. 3 is a configuration diagram showing a control configuration of a correction unit of the inkjet recording apparatus shown in FIG.

FIG. 4 is a partially enlarged view of the vicinity of a correction unit of the inkjet recording apparatus shown in FIG.

FIG. 5 is an explanatory diagram for explaining how a recording medium enters a correction unit.

FIG. 6 is a schematic configuration diagram showing another example of the inkjet recording apparatus shown in FIG.

FIG. 7 is a schematic configuration diagram showing an embodiment of an inkjet recording apparatus according to claim 2 of the present invention.

8 is a schematic configuration diagram showing another example of the inkjet recording apparatus shown in FIG.

9 is a schematic configuration diagram showing an embodiment of a fixing unit of the inkjet recording apparatus shown in FIG.

FIG. 10 is a schematic configuration diagram showing another example of the correction unit of the inkjet recording apparatus according to the present invention.

11 is a schematic configuration diagram showing another example of the correction unit shown in FIG.

FIG. 12 is a schematic configuration diagram showing still another example of the correction unit of the inkjet recording apparatus according to the present invention.

13 is a schematic configuration diagram showing another example of the correction section shown in FIG.

[Explanation of symbols]

1 ... Recording medium 2 ... Original recording medium 3 ... Correction department 31 ... Heating roller 31a ... Heating element 32 ... Pressure roller 32a ... Pressure unit 32b ... spring 32c ... Eccentric cam 4 ... holding unit 5: recording medium transport unit 51 ... conveyor roller 52: driven roller 6 ... Recording head 7 ... Cutting part 8: Input section 9 ... Control unit 10 ... Warp sensor 11 ... Roll remaining amount sensor 12 ... Fixing unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toyoaki Sugaya             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Association             In-house (72) Inventor Hidenobu Oya             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company (72) Inventor Kenichiro Hiramoto             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Association             In-house (72) Inventor Shinichi Suzuki             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company (72) Inventor Makoto Kaga             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company (72) Inventor Teruyuki Fukuda             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company F term (reference) 2C056 EB12 EB14 EB30 EC13 EC14                       EC29 EC32 FC06 HA29 HA30                       HA45 HA46                 2H086 BA02 BA05 BA13 BA15 BA33                       BA35 BA41

Claims (32)

[Claims] 1. A correction step of correcting warpage of the recording medium by applying heat and pressure to the recording medium; and, after the correction step, ink is ejected onto the recording medium to form an image. An inkjet recording method comprising an image forming step. 2. The inkjet recording method according to claim 1, further comprising a step of fixing the image by applying at least heat after the image forming step. 3. An image forming step of forming an image by ejecting ink onto a recording medium; a correcting step of correcting warpage of the recording medium by applying heat and pressure to the recording medium; An inkjet recording method, comprising a fixing step of fixing the image by applying at least heat to the recording medium on which the image is formed. 4. An image forming step of forming an image by ejecting ink onto a recording medium; and correcting warpage of the recording medium by applying heat and pressure to the recording medium on which the image is formed. The inkjet recording method having a straightening step, wherein the recording medium contains a thermoplastic resin, and a heating temperature in the straightening step is lower than a temperature at which the thermoplastic resin melts. 5. An image forming step of forming an image by ejecting ink onto a recording medium having an ink absorbing layer containing an inorganic pigment and a water-soluble binder on a support; and applying heat to the recording medium. In an inkjet recording method having a correction step of correcting the warp of the recording medium by applying a pressure, the recording medium has the following heating and pressurizing conditions with respect to the recording medium having a curl value of -30 to -40 mm. The curl value of the recording medium is -10 to 10 when the heating and pressurizing process is applied.
Inkjet recording method characterized by +10 mm: heating and pressurizing conditions: a cylindrical iron cylinder having a diameter of 30 mm and a silicon rubber roller having a diameter of 30 mm at a position facing the iron cylinder are both tetrafluoroethylene-perfluoroalkyl ether. Coated with a copolymer,
Using a fixing device having a heater built in an iron cylinder, the recording medium is inserted so that the iron cylinder contacts the surface of the ink absorbing layer, and the recording medium is conveyed at a speed of 10 mm / s, a nip width is 0.3 mm, and a linear pressure is 297 mm. 32kg for the width of
f, the surface temperature of the iron cylinder is 120 ° C., and the heating and pressurizing simultaneous treatment is performed under the condition that the coating thickness of the tetrafluoroethylene-perfluoroalkyl ether copolymer with which the iron cylinder is coated is 100 μm. 6. The mass ratio of the inorganic pigment to the water-soluble binder in the ink absorbing layer of the recording medium is 3: 1 to.
It is 9: 1, The inkjet recording method of Claim 5 characterized by the above-mentioned. 7. The recording medium according to claim 5, wherein the ink absorption layer contains an emulsion resin having a glass transition point Tg of 20 ° C. or lower and polyvinyl alcohol as a dispersion medium. Inkjet recording method described. 8. The ink jet recording method according to claim 5, wherein the recording medium has a surface layer containing a thermoplastic resin on the ink absorbing layer. 9. The ink jet recording method according to claim 8, wherein the surface layer further contains an inorganic pigment. 10. The ink jet recording method according to claim 8, wherein the heating temperature in the straightening step is lower than the melting temperature of the thermoplastic resin. 11. The JIS B-0 of the ink absorbing layer
The center line average roughness specified in 601 has a reference length of 2.5.
mm, when the cutoff value is 0.8 mm,
It is 0.8 or more and 4 or less, It is characterized by the above-mentioned.
11. The inkjet recording method according to any one of 1 to 10. 12. The ink jet recording method according to claim 5, wherein the ink is a pigment ink. 13. A straightening device for straightening a warp of a recording medium by applying heat and pressure, a recording head for ejecting ink,
And an inkjet recording apparatus having a conveying section for conveying the recording medium, wherein the straightening device is arranged upstream of the recording head in a conveying direction of the recording medium. 14. The correction device according to claim 13, wherein the straightening device includes a heating roller having a heating device, and a pressure roller having a pressure device provided at a position facing the heating roller. Inkjet recording device. 15. The ink jet recording apparatus according to claim 14, wherein the straightening device includes a driven belt that is driven by the heating roller, and a pressing portion that is provided at a position facing the driven belt. . 16. The straightening device includes a first driven roller driven by the heating roller, a heating belt suspended between the heating roller and the first driven roller, a second driven roller driven by the pressure roller, and The ink jet recording apparatus according to claim 14, further comprising a pressure belt suspended from the pressure roller and a second driven roller. 17. The correction means includes a heating / pressurizing roller having a heating means and a pressing means, a driven roller driven by the heating / pressurizing roller, the heating / pressurizing roller, and a heating belt suspended by the driven roller. The inkjet recording apparatus according to claim 13, further comprising a drum roller provided at a position facing the heating belt. 18. The correction means comprises a pressure roller having a pressure means, a driven roller driven by the pressure roller, a pressure belt suspended from the pressure roller and the driven roller,
The inkjet recording apparatus according to claim 13, further comprising a heating drum roller having a heating unit provided at a position facing the pressure belt. 19. The heating roller and the pressure roller have hardnesses different from each other, and a hardness difference between them is 2 or less.
15. The ink jet recording apparatus according to claim 14, wherein the number is twice or more. 20. The ink jet recording apparatus according to claim 14, wherein one of the heating roller and the pressure roller is a metal roller and the other is a rubber roller. . 21. The ink jet recording apparatus according to claim 20, wherein the metal roller is provided on a side where the warp of the recording medium is convex. 22. The recording apparatus comprises: an input unit for inputting the thickness and type of the recording medium; and a control unit for controlling a heating temperature according to the input by the input unit. Item 22. The inkjet recording device according to any one of items 13 to 21. 23. The recording apparatus comprises: a detection unit that detects the degree of warpage of the recording medium; and a control unit that controls the heating temperature according to the output from the detection unit. Item 22. The inkjet recording device according to any one of items 13 to 21. 24. The recording medium is a roll-shaped recording medium, and the recording device detects a winding remaining amount of the roll-shaped recording medium, and a heating temperature control according to an output from the detection unit. 22. The inkjet recording apparatus according to claim 13, further comprising a control unit that performs the above. 25. The recording apparatus has an input unit for inputting a thickness and a type of the recording medium, and a control unit for controlling a pressurizing pressure according to an input by the input unit. The inkjet recording device according to claim 13. 26. The recording apparatus comprises: a detection unit that detects the degree of warpage of the recording medium; and a control unit that controls the pressurizing pressure according to the output from the detection unit. Item 22. The inkjet recording device according to any one of items 13 to 21. 27. The recording medium is a roll-shaped recording medium, and the recording device detects the amount of winding of the roll-shaped recording medium, and a pressurizing pressure according to the output from the detector. 22. The ink jet recording apparatus according to claim 13, further comprising control means for controlling. 28. The recording device according to claim 13, further comprising a guide for holding the recording medium flat, which is downstream of the straightening device in the conveying direction of the recording medium.
7. The inkjet recording device according to any one of 7. 29. The ink jet recording apparatus according to claim 13, wherein the recording medium is conveyed with a side where the warp of the recording medium is convex as an upper surface. 30. A straightening device for straightening the warp of a recording medium by applying heat and pressure, a recording head for ejecting ink,
An inkjet recording apparatus having a fixing unit having a conveyance unit that conveys the recording medium and at least a heating unit. 31. An ink jet recording medium having an ink absorbing layer containing an inorganic pigment and a water-soluble binder on a support, and a surface layer containing a thermoplastic resin on the ink absorbing layer, wherein the recording medium is , −30 to −40 mm, the curl value of the recording medium is −10 when the heating and pressurizing process is applied under the following heating and pressing conditions.
Inkjet recording medium characterized by being +10 mm: Heating and pressurizing conditions: A cylindrical iron cylinder with a diameter of 30 mm,
A silicone rubber roller having a diameter of 30 mm is covered with a tetrafluoroethylene-perfluoroalkyl ether copolymer at a position facing the iron cylinder, and a fixing device having a heater built in the iron cylinder is used. Insert the recording medium so that
Transport speed of the recording medium 10 mm / s, nip width 0.3
mm, linear pressure is 32 kgf for a width of 297 mm, the surface temperature of the iron cylinder is 120 ° C., and the coating thickness of the tetrafluoroethylene-perfluoroalkyl ether copolymer for coating the iron cylinder is heated and applied under the condition of 100 μm. Simultaneous pressure treatment is performed. 32. The ink jet recording medium according to claim 31, wherein the surface layer further contains an inorganic pigment.