JPS62244687A - Recording material and recording method using it - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Applications'n) The present invention relates to recording materials suitable for recording methods using ink, such as felt pens, fountain pens, pen plotters, and inkjet recording devices. The present invention relates to a recording material with excellent absorbency and color properties of recorded images, and a recording method for obtaining high quality recorded images.

(Prior art) Conventional recording methods using ink 1 For example, recording materials used for writing with fountain pens, felt-tip pens, ballpoint pens, etc., and recording with pen plotters, inkjet recording devices, etc. include high-quality paper, lb. Paper, general paper such as writing paper, or art paper.

Examples include coated paper such as cast neat paper.

However, in recent years, with the development of recording devices such as inkjet recording devices and pen plotters, sufficient recording characteristics have not been obtained with the above-mentioned conventional recording materials.

In other words, in recent recording methods such as those described above, high-speed recording and multi-color recording are performed that are incomparable to conventional methods.
Conventional recording materials have not reached satisfactory levels in ink absorption, color development when a plurality of inks are deposited on the same location, chromaticity, and the like.

In order to solve these problems, coated paper having a porous ink-absorbing layer on the surface of the base material, such as inkjet paper, has been devised.
Japanese Patent No. 214989 describes a sheet having a porous ink-absorbing resin layer provided on a base material.

This ink absorption layer is porous and contains pores and cracks inside, which improves the ink absorption speed.

In this way, by providing a porous ink absorption layer,
Although it is possible to increase ink absorption to some extent,
Since the absorption layer is porous, the recording material has light diffusing properties, making it impossible to obtain clear recorded images with high optical density and glossy recorded images.

In addition, since the recorded image is observed from the ink recording surface, the recording agent is configured to remain as much as possible on the surface of the absorbing layer, which has the disadvantage that the durability and storage stability of the image, such as water resistance and abrasion resistance, are inferior. There is.

As one method for solving such problems, a recording medium disclosed in, for example, Japanese Unexamined Patent Publication No. 136480/1980 is known. This recording medium has at least one highly white ink-receiving layer provided on a support, and the formed image is observed from the support. In this method, various performances such as water resistance on the viewing surface have been sufficiently resolved, but a large amount of pigment is used to enhance the white charcoal of the ink receiving layer, and as a result, whitening is high.
The attached ink is adsorbed by the pigment.

Since the amount of ink that reaches the interface between the ink-receiving layer and the support is small, the image density on the viewing surface cannot be sufficiently high, and the color properties and resolution are also poor.

In addition, recently, as the speed and quality of recording using inkjet recording devices, pen plotters, etc. has increased, there has been a demand for recording materials with dramatic recording performance.

In other words, there is a need for recording materials that are significantly superior to conventional recording materials in all aspects of recording performance, including ink absorption, recording agent color development, recorded image quality, resolution, color, recorded image density, and gloss. It's here.

As a result of research in order to provide a recording material as described above, the present inventor has discovered a material having a specific structure, which has a liquid-permeable ink transport layer and an ink retention layer, and in which the recording surface and the image observation surface are in a front-back relationship. I previously suggested recording materials.

However, in the recording materials of these prior inventions,
The correlation between various required performances, such as the ink absorbency of the formed ink transport layer, its strength, its relationship with the ink retaining layer, and its relationship with the quality of the formed image, is not clear, and it is difficult to improve certain types of performance. 0 For example, if the thickness of the ink transport layer is increased to improve ink absorption, the image density may decrease, the resolution may decrease due to the addition of If the number of particles is too large, cracks may occur in the ink transport layer or powder may fall off severely, while if the number of particles is too small, various problems may occur, such as insufficient ink absorbency.

Therefore, the above-mentioned recording materials exhibit excellent ink absorption, water resistance, blocking resistance, etc. during recording, and after recording, they exhibit image quality such as excellent color, high image density, and resolution. There is a demand for a recording material that can provide an image that has the same characteristics as those described above.

(Problems to be Solved by the Invention) However, at present, a recording material that simultaneously satisfies all of these recording characteristics has not yet been obtained.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a recording material that has an appropriate gloss on its surface and allows recording images with excellent image density to be obtained.

A further object of the present invention is to provide a recording material from which recorded images can be obtained that are excellent in water resistance, abrasion resistance, storage stability, visibility, and the like.

Still another object of the present invention is to provide a recording method that allows the above-mentioned high-quality recorded images to be easily obtained.

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

(Means for Solving the Problems) That is, the first invention has an ink transport layer and an ink holding layer containing non-staining particles and a binder with respect to the recording material. The refractive index of the particles contained in the ink transport layer is 1.
4 or more, and the thickness of the rigid ink transport layer is 21 Lm or more.

Furthermore, a second aspect of the present invention is a recording method for recording with ink on the ink transport layer of a recording material having an ink transport layer and an ink retention layer, the method comprising: recording with ink in the ink transport layer of the recording material; The recording method is characterized in that the particles contained in the ink have a refractive index of 1.4 or more, and the ink transport layer has a thickness of 2 pm or more.

As a result of intensive research in order to resolve the unclear points of the prior invention as described above, the present inventors discovered that the transparency of the recording material, in which recording is performed from the ink transport layer and the image is observed from the back side, is based on transparency. An ink transport layer is formed from particles having a specific refractive index and a binder, and the thickness of the ink transport layer formed in this way is often 27 tm or more, thereby achieving excellent ink absorbency during recording. It has been found that it is possible to achieve both excellent image quality after recording. That is, with the above configuration, the background of the image becomes moderately light diffusive, and the image quality is greatly improved by causing moderate white discoloration.

(Function) The recording material of the present invention is different from conventional recording materials in which the recording surface and the viewing surface are the same, and the recording surface and the viewing surface are in a front-back relationship.

That is, in the recording material of the present invention, recording is basically performed using ink on the ink transport layer, and the recorded image is observed from the ink retaining layer side.

The ink transport layer that primarily characterizes the present invention is mainly composed of particles and a binder, has liquid permeability, and has the function of quickly absorbing and transmitting ink attached to its surface. On the other hand, the ink retaining layer has a function of absorbing and retaining ink or recording material transferred from the ink transport layer.

At this time, the ink transport layer must have high affinity for the liquid medium in the ink, and at the same time, the recording agent (dye,
On the other hand, adsorption of colorants such as pigments and materials with color-forming properties must be low.

Therefore, the ink transport layer is constructed by selecting a material that has properties such as wetting, penetration, and diffusion for the ink medium, but does not have properties such as adsorption, penetration, and reaction for the recording material. There must be.

The ink retaining layer, which is the second feature of the present invention, must have a stronger ability to absorb ink than the ink transport layer in order to stably absorb and capture the ink temporarily absorbed by the ink transport layer.

Therefore, the ink retaining layer must have high affinity for the recording agent as well as for the ink medium.

Hereinafter, the present invention will be explained in more detail based on preferred embodiments.

The recording material of the present invention includes a base material as a support, an ink retaining layer formed on the base material that absorbs and captures the ink or recording agent, and an ink retaining layer formed on the ink retaining layer. The recording material is composed of an ink transport layer that directly receives the recording material, has liquid permeability, and leaves virtually no recording material behind.

However, if the ink transport layer or the ink retention layer also functions as a base material, the base material is not necessarily required.

As the base material used in the present invention, any conventionally known base material can be used, and specifically, polyester resin, diacetate resin, triacetate resin, polystyrene resin, polyethylene resin, polycarbonate resin, polymethacrylate resin, cellophane, celluloid. Examples include plastic films, plates, and glass plates such as polyvinyl resin, polyvinylidene chloride resin, and polyimide resin. The thickness of these base materials may be any thickness, but is generally about 1ILm to 5.000ILm.

Note that, as described above, in the present invention, since a recorded image is observed from the side opposite to the recording side, the base material needs to have light-transmitting properties.

In addition, the base material used may be subjected to any processing as long as it finally has translucency. For example, the base material may be given a desired pattern, an appropriate gloss, or a textured pattern. It is possible to apply Furthermore, by selecting a base material having water resistance, abrasion resistance, etc., it is also possible to impart water resistance, abrasion resistance, etc. to the image observation surface of the recording material.

The ink transport layer constituting the recording material of the present invention needs to have an appropriate porosity and a thickness of 21 Lm or more in order to exhibit appropriate liquid permeability. refers to the property of allowing ink to pass through in accordance with the ink absorbency of the ink retaining layer and substantially preventing the recording agent in the ink from remaining within the ink transport layer, in order to adjust the liquid permeability of the ink transport layer. A preferred embodiment is to form a porous structure having appropriate cracks and communicating pores inside the ink transport layer.

Furthermore, as described above, in the present invention, in order to observe a reflective recorded image from the opposite side of the recording surface, it is preferable that the ink transport layer that forms the background of the image has an appropriate amount of white charcoal and appropriate light diffusing properties. .

Such appropriate white charcoal and appropriate light diffusivity (opacity) are achieved by forming a layer containing particles having a refractive index of 1.4 or more to a thickness of 2 pm or more.

The ink transport layer for satisfying the above characteristics is preferably mainly composed of particles that are non-staining to the recording material and have a refractive index of 1.4 or more, and a binder.

Such particles include the recording agent in the ink, that is,
Any particles may be used as long as they do not substantially adsorb dyes, etc., and particularly suitable particles in the present invention include highly hydrophobic thermoplastic resins, thermoplastic resins, etc., since dyes in inks are generally water-soluble. Organic particles such as curable resins, such as polystyrene, polymethacrylate, elastomer, ethylene-vinyl acetate polymer, styrene-acrylic copolymer, polyester, polyacrylic, polyvinyl ether,
At least one of resin powders such as polyamide, polyolefin, guanamine, and SBR, and their emulsions and suspensions may be used as desired. Preferably, such particles have a particle size in the range of 0.1 to 100 μm.

Further, in order to increase the white charcoal content of the ink transport layer, a white inorganic pigment may be added to an extent that does not impede the ink permeability of the ink transport layer.

Further, the binder used has a function of binding the particles to each other and/or to the ink retaining layer, and is preferably non-staining to the recording material like the single particles.

Preferred materials for the binder include any conventionally known materials as long as they have the above-mentioned functions.For example, polyvinyl alcohol, acrylic resin, styrene-acrylic copolymer, ethylene-vinyl acetate copolymer. , starch, polyvinyl butyral, gelatin, casein, ionomer, gum arabic, carboxymethylcellulose, polyvinylpyrrolidone, polyacrylamide, phenol, melamine, epoxy, styrene-butadiene rubber, urea resin, phenolic resin, α-olefin resin, chloroprene, nitrile rubber, etc. One or more of these resins can be used as desired.

Furthermore, in order to improve the function as an ink transport layer, various additives such as surfactants, penetrants, etc. may be added to the ink transport layer as necessary.

The mixing ratio (weight ratio) of the particles and the binder is preferably in the range of particles/binder = 1/3 to 50/l, more preferably in the range of 3/l to 20/1. . If there is too much binder in this mixing ratio, there will be fewer cracks and communicating pores in the ink transport layer, reducing the ink absorption effect, and if there are too many particles in this mixing ratio, the porosity will be high. However, the image quality deteriorates, and furthermore, the adhesion between the particles or between the ink retaining layer and the particles becomes insufficient, and the strength of the ink transport layer becomes insufficient or the layer cannot be formed.

The thickness of the ink transport layer depends on the amount of ink, but is preferably 2 μm or more, more preferably 3 to 807 μm.
It is zm. If the thickness is less than 2 pm, even if particles with a specific refractive index as described above are used, it will not be possible to impart appropriate whiteness and light diffusivity to the ink transport layer, and the ink transport properties and transport of the ink transport layer will be impaired. The speed etc. become unfavorable due to the relationship with the ink retaining layer.

Next, the non-porous ink retention layer that substantially captures the ink or recording agent absorbs and captures the recording agent in the ink that has passed through the ink transport layer, and substantially permanently retains the recording agent.

The ink retaining layer needs to have a stronger ink absorption ability than the ink transport layer. This is because when the absorption power of the ink retention layer is weaker than the absorption strength of the ink transportation layer, the ink applied to the surface of the ink transportation layer passes through the ink transportation layer, and the tip of the ink reaches the ink retention layer. When the ink reaches the ink, the ink stays in the ink transport layer, so that the ink permeates and diffuses laterally within the ink transport layer at the interface between the ink transport layer and the ink retention layer. As a result, the resolution of the recorded image decreases, making it impossible to form a high-quality recorded image.

Furthermore, as described above, since the recorded image is observed from the side opposite to the recording surface, the ink retaining layer is preferably light-transmissive.

An ink retaining layer that satisfies the above requirements is a light-transmitting resin that adsorbs the recording agent and/or is soluble in the ink.
Preferably, it is made of a light-transmitting resin that has swelling properties.

For example, when a water-based ink containing an acid dye or a direct dye is used as the recording material, the ink-retaining layer is made of a resin that has adsorption properties for the dye, such as a water-soluble resin that has swelling properties for the water-based ink. It is preferable that the ink retaining layer is made of a lignophilic polymer.The material constituting the ink retaining layer is not particularly limited as long as it has the function of absorbing and trapping ink and can form a non-porous layer. It's not something you can do.

The thickness of the ink retaining layer may be sufficient as long as it absorbs and traps ink, and although it varies depending on the amount of ink droplets, it is preferably 1 to 50 ILm, more preferably 3 to 2 ILm.
0ILm.

The material constituting the ink retaining layer may be any material as long as it can absorb water-based ink and retain the coloring material in the ink. Examples of such water-soluble or hydrophilic polymers, which are preferably formed from natural polymers, include albumin, gelatin, casein, starch, cationic starch, gum arabic, natural resins such as sodium alginate, carboxymethyl cellulose, and hydroxyethyl cellulose. , polyamide, polyacrylamide, polyethyleneimine, polyvinylpyrrolidone, quaternized polyvinylpyrrolidone, polyvinylpyricillium halide, melamine resin, phenolic resin, alkyd resin,
Polyurethane.

Synthetic resins such as polyvinyl alcohol, ion-modified polyvinyl alcohol, polyester, and sodium polyacrylate, preferably wood-philic polymers made by crosslinking these polymers to make them water-insoluble, and wood-philic and water-philic polymers composed of two or more types of polymers. Examples include insoluble polymer complexes, wood-philic and water-insoluble polymers having wood-philic segments, and the like.

As a method for forming an ink retaining layer and an ink transport layer on a substrate, a coating solution is prepared by dissolving or dispersing the materials preferably listed above in a suitable solvent.

The coating liquid may be applied, for example, by a roll coating method.

Lot bar coach ink method, spray coating method,
Preferably, the coating is applied onto a substrate by a known method such as an air knife coating method, and then quickly dried.
The above-mentioned material may be hot-melt coated, or a single sheet may be formed from the above-mentioned material, and the sheet may be laminated onto a base material.

However, when providing the ink retaining layer on the base material, it is preferable to strengthen the adhesion between the base material and the ink retaining layer by, for example, forming an anchor coat layer, and to eliminate spaces.

If a space exists between the base material and the ink retaining layer, the surface of the recorded image will reflect diffusely, which will substantially lower the optical density of the image, which is not preferable.

Means for recording images using the recording material of the present invention include fountain pens, ballpoint pens, and felt-tip pens.

Examples include recording instruments and recording devices that use ink containing a recording agent, such as pen plotters, ink misters, ink jets, and various types of printing.

From the viewpoint of high-speed image recording, inkjet recording devices and pen plotters are suitable.

The ink used in the recording method of the present invention can be a conventionally known water-based and/or oil-based ink, but in order to quickly penetrate the ink transport layer and be quickly absorbed and captured by the ink retention layer, , the viscosity of the ink is 500 cp
It is necessary that the value is less than or equal to s. Preferably, the viscosity is 1
00 cps or less, preferably 50 cps or less.

In addition, water-based inks are preferable in consideration of safety against fire and stain resistance against the environment.

As the recording agent contained in the ink, conventionally known coloring agents such as dyes and pigments and/or materials having color-forming properties can be used.For example, recording agents used in inkjet recording include direct dyes, basic dyes, etc. , Reactive Dye 1 Water-soluble dyes typified by food coloring and the like are preferred.

In the recording method of the present invention, since the recording surface and the observation surface are in a front-back relationship, when printing characters, it is necessary to use a device that can print mirror characters, unlike the conventional method.

However, in the recording material of the present invention, the ink transport layer can be made transparent by heating after recording, and in such a case, the recording surface can also be used as an observation surface. Therefore.

In such a case, characters etc. may be recorded in a normal state.

(Examples) Hereinafter, the present invention will be specifically described based on Examples. In addition, unless otherwise specified, % or parts are based on gi amount.

Example 1 A polyethylene terephthalate film (thickness 100 μm, manufactured by Toshi) was used as a translucent base material, and the following composition A was coated on this base material using a bar coater method so that the dry film thickness was 8#Lm. It was coated and dried in a drying oven at 110°C for 10 minutes.

Benikō 1L Comb-shaped polymer (25% methyl cellosolve solution) 60 parts Methyl vinyl ether/maleic anhydride monoethyl ester) lt (+1; antrez ES-425, G
Made by AF.

10% water/ethanol solution) 40 parts
The above comb-shaped polymer is obtained by graft polymerizing 20 parts of methyl methacrylate macromer to 80 parts of the main chain (a copolymer of 64 parts of 2-hydroxyethyl methacrylate and 16 parts of dimethyl acrylamide).

Furthermore, the following composition B was applied on top of it to a dry film thickness.

Coat by bar coater method so that it becomes 20pLm8
It was dried in a drying oven at 0°C for 10 minutes.

Low-density polyethylene resin (CHEMPART 200, manufactured by Mitsui Petrochemical Industries, Ltd., solid content 40%, refractive index 1.51) 100 parts Ethylene-vinyl acetate copolymer resin (CHEMPART V-TOO, manufactured by Mitsui Petrochemical Industries, Ltd., Solid content: 40%) 10 parts Perfluoroalkyl phosphate ester (S-112 manufactured by Asahi Glass Co., Ltd.) 0.2 parts The thus obtained recording material of the present invention was white and opaque.

Examples 2 to 4 White and opaque recording materials of the present invention were obtained in the same manner as in Example 1, except that the following compositions were used in place of composition B in Example 1.

C. 2 Acrylic resin (Microsphere PM, manufactured by Matsumoto Yushi Seiyaku, refractive index 1.49) 100 parts Styrene-butadiene copolymer resin (L-2337, manufactured by Asahi Kasei, solid content 50%) 18 parts Sodium dioctyl nulphosacsi Nate (Helex 0T-P, manufactured by Kako)
0.15 parts water
55 parts D---3 Ethylene-vinyl acetate copolymer resin (V-200, manufactured by Mitsui Petrochemical Industries, solid content 40%, refractive index 1.47) 100 parts Ionomer resin (Chemipearl SA-100, manufactured by Mitsui Petrochemical Industries, Ltd. 10 parts perfluoroalkylcarboxylic acid fil (S-111, manufactured by Asahi Glass)
0.2 parts E-4 Polystyrene resin (L-8801, manufactured by Asahi Kasei, solid content 4
8%, refractive index 1.59) 100 parts ionomer resin (Chemipearl SA-100, manufactured by Mitsui Petrochemical Industries, solid content 37%) 13 parts perfluoroalkyl carboxylate (S-113, manufactured by Asahi Glass)
0.2 part Comparative Example 1 In Example 4, Composition E resulted in a dry film thickness of 1.5 μm.
A white and opaque recording material of a comparative example was obtained in the same manner as in Example 4 except that a layer of m was formed.

Comparative Example 2 A white and opaque recording material of a comparative example was obtained in the same manner as in Example 4 except that Composition F below was used in place of Composition B in Example 1.

Benijo J Teflon resin (30L, Mitsui DuPont fluorochemical acid, refractive index 1.35) 100 parts Ionomer resin (Chemipearl SA-100, manufactured by Mitsui Petrochemical Industries, solid content 37%) 27 parts Perfluoroargyl carbon Acid acid (S-111, manufactured by Asahi Glass)
0.2 parts water
20 parts Example 5 and Comparative Example 3 Using the following four types of ink on each of the recording materials of the above Examples and Comparative Examples, bubbles were generated with one heating resistor, and the ink was blown by the pressure. Each solid inkjet recording was performed using a recording apparatus having an on-demand type inkjet recording head. 4 used
The composition of the seed ink is shown below, and it was tested and evaluated in accordance with the following method to determine whether it was sufficiently suitable for the purpose of the present invention for the recorded matter thus obtained. The evaluation results are shown in Table 1 below.

Artificial U (composition) C1■, Acid Yellow 23 2 parts diethylene glycol 15 parts water
85 part Rinami z! (Composition) C, 1, Acid Red 92 2 parts diethylene glycol 15 parts water
85 parts Nursery U (composition) C, 1, Direct Blue 86 2 parts diethylene glycol 15 parts water
85 parts 1 zl (composition) C,l Direct Black 19 2 parts diethylene glycol 15 parts water
85 parts (1) Ink absorption is after inkjet recording.

The recorded matter was left at room temperature, and the time required for the ink to sufficiently dry and fix without adhering to the finger even when the recorded portion was touched with a finger was measured.

(2) The image optical density (0,0,) is the Macbeth densitometer T
Image observation side A for black ink recording area using R524
and measured from recording surface B.

(3) Whiteness is measured using a Hunter set colorimeter using JIS
Measurement was made from the image observation surface side of the recording material according to the method of P-8123.

(4) Color clarity was determined by visually comparing the color clarity of inkjet recorded images from the image viewing surface side, and ranking the best one as O, the worst as ×, and ranked Olo, Mu, and ×.

The above results are shown in Table 1.

(Effects) With the recording material of the present invention configured as described above, it is not impossible to observe the recorded image from the side recorded with ink, like ordinary paper.

By observing the recorded image from the side opposite to the recording surface, that is, from the ink retaining layer or the base material side, excellent effects not available in the past can be obtained.

That is, since the ink retaining layer has translucency, 1
Diffuse reflection on the image viewing surface is reduced.

A high image optical density that could not be achieved when recording with ink on a porous sheet such as paper can be obtained.

In addition, since the ink transport layer, which serves as the recording surface, is formed using particles with a specific refractive index and has a thickness of 2 pm or more, the background of the image exhibits appropriate white discoloration and light diffusivity. Improves ink absorption and recorded image density,
It is possible to provide images with high contrast, excellent brightness, resolution, color, etc.

Furthermore, when a translucent substrate is used as the substrate, in addition to the above-mentioned effects based on the substrate's optical transparency, the recorded image has gloss, water resistance, weather resistance, and abrasion resistance. Granted.

The recording material of the present invention is significantly superior to the conventional method of laminating a transparent film on the surface of the recorded image in terms of the optical density of the recorded image and the operability when creating the recorded image. .

(Left below) IIL-Ni'acid 2m-Arashim (Recorded material) 12 dan 4 1
2nd construction IL recovery 2 seconds 1 second 2 seconds 1 second 60 seconds 2 seconds zL Abnormality A 1.72 1.88 1.80
1.78! ,22 1.88BO
420,O50,590,5B 0.88 0
．． 85- 80.3 81.5 82
．． 0 83.2 78.8 75.111+
OO@OΔ

Claims (11)

[Claims] (1) It has an ink transport layer and an ink retention layer containing particles that are non-stainable to the recording material and a binder, and the refractive index of the particles contained in the ink transport layer is 1.4 or more. A recording material characterized in that the thickness of the ink transport layer is 2 μm or more. (2) The recording material according to claim (1), wherein the ink transport layer and the ink retention layer are laminated on a base material. (3) The recording material according to claim (2), wherein the base material is translucent. (4) Claim No. 2, wherein the ink transport layer is porous (
The recording material described in item 1). (5) The recording material according to claim (1), wherein the ink retaining layer is non-porous. (6) The recording material according to claim (1), wherein the ink retaining layer is mainly composed of a water-soluble or hydrophilic polymer. (7) The ink transport layer is light-diffusing, and the ink-retaining layer is more light-transmissive than the ink transport layer.
The recording material described in item 1). (8) The recording material according to claim (1), wherein the ink retaining layer has a stronger ink absorption ability than the ink transport layer. (9) The recording material according to claim (1), wherein the ink transport layer has communicating holes. (10) The recording material according to claim (1), wherein the ink transport layer includes cracks. (11) A recording method for recording with ink on the ink transport layer of a recording material having an ink transport layer and an ink retention layer, the method comprising: A recording method characterized in that the refractive index is 1.4 or more and the thickness of the ink transport layer is 2 μm or more.