JPH0216078A - Ink jet recording method - Google Patents

Abstract

PURPOSE:To inhibit an ink from bleeding and diffusing to obtain an accurate and sharp image by incorporating a pigment having high dye trapping properties in a coated layer and determining a maximum recording density to be less than the initial transfer amount of a recording medium. CONSTITUTION:A recording material in use is provided with a surface layer mixed with a silica or alumina pigment having a BET specific surface area of 200m<2>/g or less and the same fiber as a base. For example, a coating liquid of fine powder silica having a particle diameter of 8mum and a water solution of polyvinyl alcohol is applied on a filter paper for qualitative analysis. This coated paper is recorded with a water ink containing 5-50% polyvalent alcohol. The coated paper is 44ml/m<2> in initial transfer amount (a liquid transfer amount at a contact time of 10msec. by a Bristol method), free from bleeding, and superior in ink absorptivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an inkjet recording method, and particularly to a multicolor inkjet recording method that provides high-density, high-definition images.

[Conventional technology]

In multicolor inkjet recording systems that use recording liquids of two or more different colors, special paper is often used in view of the coloring properties of the colorants and the ink absorption properties.

Conventionally, such recording materials include: (1) general paper containing bulbs as its main component, made into a small size paper such as filter paper or blotting paper, and (2) base material. It is known that a coating layer is provided thereon using a porous pigment such as silica or zeolite that has a large oil absorption capacity and adsorbs the coloring components in the ink.

Recording material (1) can be produced at a low cost, and although it has excellent ink absorption, the ink penetrates deeply into the fiber layer of the paper, resulting in poor color development of the colorant in the ink. Because it is absorbed along the fibers on the paper surface, a phenomenon called feathering occurs, causing dots to become jagged instead of circular, and dots to become too large, resulting in a decrease in resolution and the inability to obtain high-quality images. There was a drawback.

For this reason, such uncoated paper has been used mostly for monochrome recording, personal computer terminals, and other applications that have relatively low resolution and do not require high-density images.

As the recording material (2), conventionally, for example, JP-A-58-13
Coated paper based on relatively high-sized paper (commercially available high-quality paper) described in JP-A No. 2586 and JP-A-59-35977 can be mentioned.

These coated papers have a porous and uniform ink-receiving layer, so they have appropriate ink absorption and can produce images with excellent dot shape and resolution. The required recording method requires that a larger amount of ink be absorbed and fixed at high speed. We have responded.

However, as the amount of coating increases, the coating layer may peel off from the base paper when the recording material comes into contact with the conveyance system in the recording device.
So-called powder falling occurs, which not only pollutes the inside of the device, but also
This may cause the nozzles of the inkjet head to become clogged.

Furthermore, due to the large amount of coating applied during the manufacturing process, migration of the binder occurs, resulting in a decrease in the strength of the coating amount and a decrease in ink absorption.

Such problems can be solved to some extent by relaxing the drying conditions or dividing the number of coats, but this increases manufacturing costs.

These drawbacks can be improved by providing a porous pigment layer on a base paper of low sizing, for example, as disclosed in JP-A-59-1856
No. 90 exemplifies a recording material having a coating layer containing silica containing a specific substance on a base paper having a size degree of 4 seconds or less.

Although this type of recording material has excellent ink absorbability even when a relatively thin ink receiving layer is provided, it has the following drawbacks.

(1) The ink-receiving layer is thin and cannot hold much ink, and a large amount of ink penetrates deeply into the base paper, resulting in decreased printing density, deterioration of dot shape, and resolution due to excessive bleeding of adhered ink droplets. , deterioration of print quality.

(2) During coating, the binder in the coating liquid is absorbed by the base paper of low size, resulting in powder falling on the surface despite the thin coating layer.

Furthermore, with the demand for faster and higher recording density, inkjet heads have become multi-nozzle, and the nozzle arrangement has become more dense. A drawback has also become apparent, which is a problem called bleeding, in which the ink bleeds and mixes at the boundaries of prints of different colors.

The above problems are unique to absorbent type coated paper that uses a thin coat layer and absorbent base paper.
In particular, the above-mentioned bleeding problem is a serious problem as it directly causes a deterioration in image quality.

The above problems are thought to be caused by the ink-receiving layer, the base paper, and the amount of ink adhered to each other, but there is no known method to solve the above problems by focusing on the mutual relationship between these. There wasn't.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned drawbacks, to provide a recording material that has quick ink absorption even if the coating layer is thin, has excellent dot shape, and has a suitable dot bleeding rate. It is an object of the present invention to provide an inkjet recording method that forms high-definition and clear images using.

A further object of the present invention is to provide an inkjet recording method that allows high-definition images to be obtained without the aforementioned bleeding problem even when high-density recording is performed.

[Means for solving problems]

The above object is achieved by the present invention as follows.

That is, the present invention provides an inkjet recording method in which recording is performed by attaching small droplets of recording liquid to a recording material, wherein the maximum recording density is less than or equal to the initial transfer amount of the recording material. It is.

[For production]

In an inkjet recording method using a water-based ink, the present inventors particularly aimed to obtain a recording material that solved the drawbacks of the prior art as a recording material (as a result of intensive research, it was found that even if the recording material is Even though the coating layer is thin, it provides high ink absorption, excellent color properties, and image density, and adhered ink droplets do not bleed too much, have an appropriate bleed rate, and have a dot shape, producing high-definition, high-quality images. The present invention was achieved by discovering an inkjet recording method suitable for providing the above information.

In addition, the present inventors have investigated the issue of bleeding in the direction of inkjet printing, which performs high-density and high-speed recording using absorbent coated paper; The problem of bleeding can be significantly improved when a recording material with a specific physical property value (the amount of liquid transfer at a contact time of 10 milliseconds using the Bristow method, hereinafter referred to as the initial transfer amount) is used in relation to the recording density. I found out that.

In other words, the above-mentioned bleeding problem occurs when the ink absorption capacity of the recording material is less than the amount of adhered ink. This is a separate issue from the ink flow that occurs when printing with multiple colors of ink overlapping each other.

The present invention will be explained in detail below.

For details of the method for measuring liquid permeation amount using the Bristow method, which mainly characterizes the present invention, please refer to
vensk Paperstidn Nr19 r Liquid Absorption 1nt
o Paper During Short Time
Intervals (J, Authony Bris
tow) J. In addition, the initial transfer amount referred to in the present invention is determined based on the method described in J. This charge was set to 0.5 Kg/crrf. Recording materials that are excellent in inkjet suitability often have weak wet strength of the coating layer or base paper, so it is necessary to measure the strength at a level not exceeding 0.5 Kg/crrf.

In addition, in the present invention, diethylene glycol 3 is used as the test liquid.
The measurements were carried out using distilled water containing 0% by weight.

This means that the amount of liquid transferred to the paper is v=Kr-1-Ka [7cosθ(t-tw)/
77]! 4......Song ■V: Liquid transfer amount Kr: Roughness index Ka: Absorption coefficient
γ: Surface tension of liquid θ: Contact angle
t: absorption time tW: wetting time
η: Represented by a general formula for the viscosity of a liquid, it is difficult to obtain accurate values using conventional testing methods that use distilled water, and as mentioned above, the inkjet inks currently in use are prone to nozzle clogging. In order to solve problems such as
This is because it is a water-based ink containing 5 to 50% by weight of polyhydric alcohol.

The recording method of the present invention is achieved by using a recording material whose initial transfer amount determined by the method described above is greater than or equal to the maximum recording density. That is, when a recording material whose initial transfer amount is less than the maximum recording density is used, the above-mentioned bleeding problem occurs.

As mentioned above, the problem of bleeding is a problem specific to the base paper absorbing type of slightly coated paper, which does not occur with heavy coated paper.
Even if the paper has the same level of Steckigt size as described in Japanese Patent Application No. 9-185690, Rem water absorption as shown in Japanese Patent Application Laid-open No. 109783/1983, or Cobb water absorption according to JIS-P-8140, It was found that there are cases where bleeding occurs and cases where it does not occur.

This means that the problem of adhering ink penetrating the paper and bleeding does not contribute to the paper's ink absorbency of the order of seconds or tens of seconds as described above, but rather that it This is thought to be because it is a matter of seconds.

The present inventors believe that the Bristow method is optimal for analyzing problems related to ink penetration into paper and bleeding in inkjet recording, and that the problem of bleeding in particular has a strong correlation with the initial transfer amount. We found that.

The maximum recording density of the recording method used in the present invention refers to the maximum amount of ink application (m
f/rrr).

For example, if the nozzle pitch d (mm) and the nozzle average ejected droplet volume v (nI) are yellow (
Y), magenta (M), cyan (C), black (Bk
), the maximum recording density p(
mj! /a) is 1, p=nv/d”・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
......Represented by ■. The average ejected droplet volume of a nozzle referred to here is the average value of the volume per droplet when single ejection is performed for each nozzle, and the average value for each nozzle is further averaged. . In the above formula, n is the maximum number of overlapping prints, and in monochrome printing, n=1. Y, M
, C and their mixed colors, red (R), green (
In so-called business color printing, which consists of seven colors, G), blue (Bl), and Bk, n = 2, and in Victorian color printing, which aims to reproduce even more tones, 2≦n≦3. be. Of course, the maximum number of overprints (
n) is determined as a value for the entire system (including image processing), not just the recording device.

The present invention will be specifically explained below by giving examples of preferred embodiments of the recording material used in the present invention. Note that the example shown below is one of the preferable examples, and it is possible to use other embodiments that meet the requirements of the present invention in addition to the following embodiments.

The base paper as a support for the recording material is conventionally known LBKP.
Although the bulb is mainly made of wood bulbs such as SNBKP, synthetic fibers or glass fibers may be mixed therein if necessary.

Specific examples of the filler used for the base paper of the recording material in the method of the present invention include clay talc, kaolinite, titanium oxide, calcium carbonate, etc.
-8128, the content is preferably in the range of 2 to 15%, more preferably 4 to 10%.

If the ash content is less than 2%, the ink droplets will smear significantly and the shape of the ink droplets will deteriorate, resulting in a decrease in print quality and the problem that the amount of liquid transfer per 10 milliseconds cannot be increased. If it exceeds 15%, the recording material loses its stiffness, causing a problem in retractability.

In addition to the above-mentioned materials, the base paper is made using conventionally known papermaking aids, sizing agents, fractionation improvers, paper strength enhancers, etc., as necessary. From the viewpoint of storage stability of recorded images, etc., a neutral papermaking method is preferable to an acidic papermaking method using sulfuric acid band.

Furthermore, for the purpose of enhancing the strength, water resistance, etc. of the surface of the base paper, surface size pressing may be performed using a conventionally known surface sizing agent such as starch, oxidized starch, or polyvinyl alcohol.

In the method of the present invention, the amount of liquid transfer in 10 milliseconds of the recording material is increased (in order to adjust the amount of liquid transferred in 10 milliseconds, the Steckigt size degree of the base paper adjusted as described above is adjusted to 0 to 15 seconds. ,
Preferably it is 0 to 10 seconds, more preferably 0 to 5 seconds.

Furthermore, in the base paper absorption type recording material used in the method of the present invention, the basis weight of the base paper is also important, and preferably 70 g/
rI? As mentioned above, it is more preferable to set it as 90 g/rd or more. In particular, if the basis weight is less than 70g/-, the recording material that has absorbed the ink may become wavy (knotkling) or
In addition to causing the problem of bleed-through, the amount of liquid transferred in 10 milliseconds is also reduced.

The next preferred porosity of the base paper is 40% or more, more preferably 60% or more. If the porosity is less than 40%, even if a base paper with a large basis weight is used, the amount of transfer in 10 milliseconds cannot be increased.

In the method of the present invention, the surface smoothness of the recording material is also an important factor. This is because, as is clear from the equation (2) above, the amount of liquid transfer has a high correlation with the roughness index (kr) of the paper. In particular, in a small range t, it is influenced more by the surface properties of the paper than by the liquid properties. The following two methods are available for adjusting a low-smooth recording material.

(3) When using a base paper with low smoothness as the base paper, (
4) When lowering the surface smoothness in the process of forming the ink-receiving layer, the preferred Bekk smoothness (J
IS-P-8119) is 40 seconds or less, preferably 20 seconds or less. In the case of (4), the influence of the smoothness of the base paper is small (although it is still preferable to use a base paper with a low smoothness of about 40 seconds or less).

On the other hand, the ink receiving layer is formed mainly using a pigment as a binder. Pigments include synthetic silica, magnesium silicate, aluminum silicate, calcium silicate, clay,
Examples include inorganic pigments such as talc, calcium carbonate, calcium sulfate, barium sulfate, titanium oxide, zinc oxide, alumina, satin white, and lithopone.

Among these, those preferred for the method of the present invention are synthetic silica,
These are silica-based pigments such as aluminum silicate, calcium silicate, and magnesium silicate, and alumina-based pigments. These pigments have many fine internal pores that absorb solvents, dyes, etc. in the ink, and color development is better when these colorants are captured in the outermost layer of the ink-receiving layer. In addition, this is because it is preferable to design a high amount of liquid transfer in 10 milliseconds.

The preferred BET specific surface area of these pigments is 200
r+? /g or less, more preferably 5 to 150 rrr
/g.

More preferably, it is within the range of 10-100 rrr/g.

According to the findings of the present inventors, it is preferable for the specific surface area of the pigment to be high for the reasons mentioned above, but when a pigment exceeding 200 d/g is used, the problem of indoor discoloration of printed matter becomes particularly noticeable. Indoor discoloration is a problem specific to coated paper, and even when stored in an atmosphere that is not exposed to direct sunlight, the Bk printed area may turn brown, which is a serious problem.

When using a pigment with a specific surface area of 200d1g or less,
Although there is a problem that the color development of the dye is somewhat low, this point can be compensated for by using a pigment whose surface is cationic.

That is, it is a method of adsorbing the dye onto the pigment by using the acidic groups (sulfonic acid group, carboxylic acid group, etc.) that the dye has, and preferable pigments have a specific surface area of
Alumina of 200d/g or less, specific surface area of 2oorr
Examples include those in which the surface of silica having a size of f/g or less is cationized with an organic or inorganic aluminum compound or an amine-based silane coupling agent.

On the other hand, binders include starch, oxidized starch, gelatin, casein, gum arabic, sodium alginate, carboxymethylcellulose, polyvinyl alcohol, polyvinylpyrrolidone, water-soluble polymers such as sodium polyacrylate, SBR latex, MBK latex, and vinegar emulsion. , water-dispersed polymers such as acrylic emulsions, etc., and one or more of these may be used.

The ink-receiving layer also contains water-resistant agents (dye fixing agents), dispersants, fluorescent dyes, pH adjusters, antifoaming agents, lubricants, preservatives,
Additives such as surfactants may also be included.

The above-mentioned recording material of the method of the present invention is prepared by dissolving and dispersing the above-mentioned materials in a medium such as water. It is coated onto a support using a conventionally known method such as a coater or size press coater, and then dried as quickly as possible to adjust the coating.

A second feature of the recording material used in the method of the present invention is that the fibrous material of the base paper is present in the vicinity of the recording surface, and more preferably, the fibrous material of the base paper is present on the recording surface. It consists of a mixture of the substance and the pigment described above.

A preferable dry coating 1 of the ink receiving layer for this purpose is approximately 0.1 to 10 g/rr? , more preferably 0.5-5g
/rd. If the coating amount is less than 0.1 g/rd, problems like the above-mentioned recording material (1) will occur, and if it is more than 10 g/d, the advantages of using a small amount coating, paper There is less powder generation, less burden on manufacturing,
etc. will disappear. In particular, in the case of the above-mentioned embodiment (3), it is necessary to set the coating amount to about 0.5 to 3 g/d so that the roughness of the base paper appears on the surface.

The particle diameter of the pigment used is not particularly limited in the case of the embodiment (3), but in the case of the embodiment (4), coarse particles of about 2 to 20 μm are suitable. In other words, if it is less than 2 μm, it is difficult to give the surface an appropriate roughness;
If it exceeds m, it is advantageous in terms of initial absorption, but the dot shape deteriorates and the image becomes grainy.

The ratio of pigment and binder used in the method of the present invention is preferably 5/1 to 1/3, more preferably 3/1 to 1/2.
is within the range of If the ratio of binder used is higher than the above range, the ink absorbency will drop significantly, and if the ratio of pigment used is higher, the binding power of the binder will be low.
Problems such as powder falling from the surface of the ink receiving layer occur.

The viscosity of the aqueous coating solution obtained by dispersing the above materials is 1500 cp (centipoise) or less, more preferably 1000 cp, and still more preferably 500 cp or less, within a range that allows the desired dry coating amount to be obtained. This is desirable.

When using a coating liquid with a viscosity exceeding 1500 cp,
In addition to poor coating suitability and easy coating unevenness, coating
During drying, the amount of binder distributed near the surface layer of the recording surface increases (initial stage), resulting in a decrease in ink absorption.

The recording material obtained in this way may be subjected to super calender treatment after drying in order to increase the surface strength of the coating layer. However, if calendering is performed excessively, the initial stage of the paper This is not preferable because it causes a decrease in absorbency (amount of liquid transfer of several to tens of milliseconds in contact time according to the Bristow method).

The stability of the recording material itself obtained as described above
Size degree is 0 to 15 seconds, Beck smoothness is 0 to 40 seconds,
Is the basis weight 70g/rr? Above, more preferably 9, Og/
It is preferable that it is rrr or more. Recording materials whose Steckigt size exceeds 15 seconds, Bekk smoothness exceeds 40 seconds, or whose basis weight is less than 70 g/rrf have low initial ink absorption and are within the usable range. This is not preferable because it limits the

In the method of the present invention, the ink itself applied to the above-mentioned specific recording material by an inkjet recording method may be a known ink. These inks contain water-soluble dyes such as direct dyes, acid dyes, basic dyes, reactive dyes, and food colorings as coloring materials.

Such water-soluble dyes are generally used in a proportion of about 0.1 to 20% by weight in conventional inks, and this proportion may be the same in the present invention.

The solvent used in the water-based ink used in the present invention is water or a mixed solvent of water and a water-soluble organic solvent, and particularly preferred is a mixed solvent of water and a water-soluble organic solvent, and a water-soluble organic solvent is particularly suitable. It is preferable to use deionized water instead of ordinary water containing polyhydric alcohol, which has the effect of preventing ink from drying.

The content of the water-soluble organic solvent in the ink is generally in the range of 0 to 95% by weight, preferably 5 to 50% by weight based on the total weight of the ink.

In addition to the above-mentioned components, the ink used in the present invention may optionally contain a surfactant, a viscosity modifier, a surface tension modifier, and the like.

In the method of the present invention, the inkjet recording method for performing recording by applying the above-mentioned ink to the above-mentioned specific recording material is such that the ink is effectively separated from the nozzle and the ink is applied to the recording material, which is a projecting object. Any method may be used as long as it can give
For example, IEEE Trans Actions on Industry Applications (IEEE T
transactions on industry
Applications) Vol, JA-13,
No. 1 (February/March 1977 issue), Nikkei Electronics April 19, 1976 issue, January 29, 1973
It is described in the Japanese issue and the May 6, 1974 issue.

Among these methods, the method that is especially excellent for high-speed, high-density printing is the method that applies an electrical signal to a piezo element to create mechanical displacement, which applies pressure to the ink and causes it to be ejected from a nozzle. Among them, JP-A-54-59
In the bubble jet recording method described in Japanese Patent No. 936, ink subjected to the action of thermal energy undergoes a rapid volume change, and the acting force resulting from this state change causes the ink to be ejected from a nozzle. Excellent for forming multi-nozzles.

〔Effect of the invention〕

Since the recording material used in the method of the present invention contains a large amount of pigment with high dye-capturing properties in the coating layer, there is a high probability that the dye in the ink droplets will be captured and absorbed by the pigment, resulting in ink bleeding and Diffusion is suppressed, resulting in improved dot shape and excellent ink absorption, color development, and resolution.

Furthermore, the recording material used in the method of the present invention has excellent ink absorption properties on the order of milliseconds, and according to the method of the present invention using the above-mentioned recording material, a recording material having a thin coating layer is used. , does not generate paper dust in the device, and has a low load on the manufacturing process (not only can the recording material be obtained at low cost, but also has an excellent dot shape and a thin coating layer,
Clear, high-definition images can be obtained without the bleeding problems that are typical of inkjet paper.

Further, according to the method of the present invention, the obtained images have good storage stability, and the problem of indoor discoloration peculiar to coated paper does not occur.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. Note that "%" or "%" in the text is based on weight unless otherwise specified.

(Example) The following paper was used as the base paper.

Base paper A: Qualitative 3 paper No. 131 Toyo Roshi (manufactured by M;
Beck smoothness 0 seconds B: Quantitative 3 paper 5A Toyo Roshi (manufactured by Kiki) Beck smoothness 2 seconds C: Hard 3 paper 4A
Manufactured by Toyo Roshi ■; Beck smoothness 18 seconds/2 The above base paper C was calendered at a linear pressure of 100 kg/cm using a test super calender (manufactured by Kumagai Uita Kogyo), and the Beck smoothness was 43 seconds. did.

Commercially available inkjet paper F with Beck smoothness of 65 seconds: Canon NP paper Beck smoothness of 17 seconds A coating liquid with the following composition was applied to the above base paper at a dry coating amount of 3 g/I.
Coated with bar coater method to give TI' and heated at 120°C.
After drying for 2 minutes, recording materials for the method of the present invention and for comparison were obtained.

(Coating liquid 1 composition) Fine powder silica 12 parts (Mizukashiru P-78D manufactured by Mizusawa Chemical Co., Ltd. Average particle size 8 μm) Polyvinyl alcohol 6 parts (PVA-117
/PVA-105 made by Kuraray) water
82 parts A coating liquid having the following composition was applied to the above base paper at a dry coating amount of 2 g/rr?
The recording materials were coated using a bar coater method and dried at 120° C. for 2 minutes to obtain recording materials for the method of the present invention and for comparison.

(Coating liquid composition 2) Fine powder alumina 1 part (Alumina RG-40 manufactured by Iwatani Chemical Industry, average particle size 0.5 μm) Cationized polyvinyl alcohol 6 parts (PVA-
C-118-2A manufactured by Kuraray) cationic resin (FAA-1
00 Nittobo) 1 part water
Table 1 shows the Bekk smoothness and Steckigt sizing of the recording materials prepared in the above manner.

The following recording devices (1) to (3) are used for the recording materials listed above in the table.
Recording was performed using

Recording method (1): Recording was carried out using a bubble jet recording apparatus having an ink jet recording head with a nozzle interval of 14.2 per 1 mm.

The actual measured value of the average ejected droplet volume of the nozzles of this recording head is 0.052nf, and the maximum number of overlapping prints n=2 for Y, M, C, and Bk.

Business color printing using 7 colors of R, G, and B.
The test was carried out using the above-mentioned recording material.

The maximum recording density of this recording method is 20.9 mI! /I am.

Recording method (1): Recording was carried out using a piezojet type recording apparatus having an inkjet recording head with seven nozzles spaced at 1 mm.

The actual measured value of the average ejected droplet volume of the nozzles of this recording head is 0.079nj7, and the maximum number of overlapping prints n = 2
The printing was carried out using the above-mentioned recording material. The maximum recording density of this recording method is 7.7 ml/a.

Recording method (2): Recording was carried out using a bubble jet type recording apparatus having an ink jet recording head with a nozzle interval of 15.7 per 1 mm.

The average ejected droplet volume of this nozzle is 0.026 n I
! Full-color printing was performed with a maximum number of overlapping prints of 3. The maximum recording density of this recording method is 19.2mj
! /rr? It is.

(1) The initial transfer amount of the recording material was measured using the above-mentioned test liquid and a dynamic liquid permeation measuring device (manufactured by Toyo Seiki Seisakusho) according to the method of J. TAPPI. The circumference of the disc used for measurement was 1000 mm, the slit size of the head box was 1 mm x 15 mm, and the load on the head was 0.5 kg/crr.
Measured under f.

(2) For bleeding, mix the above-mentioned recording material with 10 parts glycerin and dye.
2 parts water
83 parts The dyes shown below were used in the above ink.

Y, C, I Direct Yellow 86 M, C, I Acid Red 35 C, C, I Direct Blue 86 Bk, C, I Hood Black 2 The printing suitability evaluation for each recording method is as follows. I did it.

However, it causes bleeding. °5″″For those observed with a thickness of 1 mm or more×, 0.5~l,
Those within the range of Om m were designated as O.

(3) Ink absorption is printed using recording method 1,
When compared to the monochromatic portion, those in which line thickening did not occur in the mixed color portion were rated as 01 and ×.

(4) O; D is 0 of Bk when recording method 3 is used.
, D, values were evaluated using a Macbeth densitometer RD-914.

(5) For indoor storage stability, the Bk printed batch used in the evaluation in (4) was hung on the wall of an ordinary office for 6 months. Color difference between the printed matter after being left and the printed matter immediately after printing (△E*
ab) was determined using Color Analyzer CA-35 (manufactured by Murakami Color Science). The above evaluation results are shown in the second
Shown in the table.

Table 2 Recording sheet Initial transfer amount Bleeding ink 0. D.

No, (mj/nf) Recording method (D
■0 Absorbency P (ml/d) 20.9 7.7
19.2OO○ ○ OO ○ O○ × ○ × X x X ×OX ○ ○ O OO.

OOO Qx × ○ × × × × x Q guidance Preservability (△E”ab)

Claims (5)

[Claims] (1) An inkjet recording method in which recording is performed by attaching small droplets of recording liquid to a recording material, wherein the maximum recording density is less than or equal to the initial transfer amount of the recording material. (2) The ink jet recording method according to claim 1, wherein the recording material is a base paper provided with an ink receiving layer containing a pigment. (3) The inkjet recording method according to claim 2, wherein the recording material has a surface layer consisting of a mixture of pigment and fibrous material of base paper. (4) The inkjet recording method according to claim 2, wherein the pigment is a silica-based and/or alumina-based pigment having a BET specific surface area of 200 m^2/g or less. (5) The inkjet recording method according to claim 1, wherein the recording liquid is an aqueous recording liquid containing 5 to 50% by weight of polyhydric alcohol.