JPS6149885A - Recording material - Google Patents

Abstract

PURPOSE:To enhance receptivity to water base inks and the clearness of recorded images, by forming an ink-permeable layer in a thickness of not larger than 10mum from a resin which is comparable to or inferior to a resin constituting an ink-holding layer with regard to hydrophilicity. CONSTITUTION:The ink-holding layer comprising a hydrophilic resin absorbent of water base inks and the ink-permeable layer having a thickness of nor larger than 10mum and formed of a resin comparable to or inferior to the above hydrophilic resin with regard to hydrophilicity are laminated on a base to produce a recording material. The ink-absorbent resin is, for example, a hydrophilic natural resin such as albumin, gelatine and casein or a hydrophilic synthetic resin such as polyamide, polyacrylamide and polyvinyl pyrrolidone. The thickness of the ink-holding layer depends on the layer of an ink used for recording, but is preferably 0.5-30mum. The thickness of the ink-holding layer is preferably larger than that of the ink-permeable layer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a recording material suitably used in an inkjet recording method, and in particular has excellent ink receptivity and clarity of recorded images. When the recording material is a translucent recording material, it relates to a recording material that has excellent ink receptivity and translucency.

(Prior Art) The inkjet recording method uses various ink (recording liquid) ejection methods, such as an electrostatic suction method, a method that applies mechanical vibration or displacement to the recording liquid using a piezoelectric element, and a method that applies mechanical vibration or displacement to the recording liquid using a piezoelectric element. In this method, small droplets of ink are generated and made to fly by foaming and using the pressure of the foam, and some or all of these droplets adhere to a recording material such as paper to perform recording, but this method generates noise. It is attracting attention as a recording method that allows for high-speed printing and multicolor printing.

Inks for inkjet recording are mainly water-based in terms of safety and recording properties.
Polyhydric alcohols and the like are often added to prevent nozzle clogging (1) and to improve ejection characteristics.

Conventionally, the recording material used in this inkjet recording method is a recording material made of a base material called ordinary paper or inkjet recording paper provided with a porous ink absorbing layer. However, as the performance of inkjet recording apparatuses improves and becomes more widespread, such as faster recording and multicolor recording, more sophisticated and wide-ranging properties are being required of recording materials. In other words, in order to obtain high-resolution, high-quality recorded images, the recording material for Infusiera I recording must: (1) fix the ink to the recording material as quickly as possible; (2) ink dots; Even if the dots overlap, the ink deposited later will not flow into the dots deposited earlier. (3) Although the ink droplets will spread to some extent on the recording material,
(4) The shape of the ink dot should be close to a perfect circle and its circumference should be smooth. (5) The OD of the ink dot should be the same. It is necessary to satisfy basic requirements such as high optical density (optical density) and no blurring around the dots.

Furthermore, in order to obtain high-resolution recorded image quality comparable to that of color photography using the multicolor inkjet recording method, in addition to the performance requirements listed in (6) the coloring components of the ink must have excellent color development; (7) The ink fixation properties are particularly excellent since the same number of droplets as the number of ink colors may adhere to the same spot, (8) The surface must be glossy, (9) White A high level of performance, etc., is required with emphasis on performance.

In addition, images recorded by the inkjet recording method have traditionally been used exclusively for surface image observation, but as the performance of inkjet recording devices improves and becomes more widespread, recorded images have become suitable for uses other than surface image observation. There is a growing demand for materials. The recording material is used for purposes other than surface image observation, such as projecting recorded images onto a screen or the like using an optical device such as a slide or 0HP (over-height projector), and observing those images. Examples include color separation plates for creating positive plates for color printing, and CMF (color mosaic filters) used in color displays such as liquid crystals.

When a recording material is used for surface image observation, the diffused light of the recorded image is mainly observed, whereas for recording materials used in these applications, the problem is mainly the transmitted light of the recorded image. Become. Therefore, it is required to have excellent light transmittance, especially linear light transmittance, in addition to the above-mentioned performance requirements of the general recording material for inkjet recording.

(The problem that the invention is trying to solve) However,
The reality is that there is still no known recording material that satisfies all of these required performances.

Furthermore, most conventional recording materials for surface image observation use a method in which a porous ink absorbing layer is provided on the surface, and a recording liquid is absorbed into the porous voids to fix the recording agent.

On the other hand, when the surface of the ink absorption layer is non-porous, non-volatile components such as polyhydric alcohols in the ink remain on the surface of the recording material for a long time after recording, and the drying and fixing time of the ink is long. However, there are disadvantages in that clothing may get dirty or the recorded image may be damaged if it comes into contact with the recorded image.

An object of the present invention is to provide a recording material for inkjet recording that is particularly excellent in ink receptivity and the clarity of recorded images. 1 Yet another object of the present invention is to use an optical device such as a slide or an OHP to project a recorded image onto a screen for observation, a color separation plate for creating a positive plate for color printing, or a liquid crystal display. An object of the present invention is to provide a translucent recording material for Infusiera I recording that can be used for transmitted light observation of CMF and the like used in color displays.

- The above and other objects of the invention are achieved by the following invention.

(Disclosure of the Invention) That is, the present invention is a recording material comprising an ink retaining layer and an ink permeable layer, and the thickness of the ink permeable layer is 1107L or less.

To explain the present invention in detail, the recording material of the present invention has 1011. The main feature is that an ink-permeable layer having a specific property and having a thickness of not more than m is provided, and the object of the present invention has been mainly achieved thereby.

The recording material of the present invention generally comprises a base material as a support, an ink retaining layer provided on the surface thereof, and an ink permeable layer provided on the ink retaining layer 1-.For example, as a particularly preferred main embodiment, (1) All of the base material, the ink retaining layer, and the ink transmitting layer are translucent, and the recording material as a whole is translucent; (2) At least the base material, the ink retaining layer, and the ink transmitting layer are translucent. Examples include an embodiment in which one layer is opaque and the entire recording material is opaque.

In any of the above cases, the ink retaining layer may also have the function of a support.

To explain the invention in more detail using the above two preferred embodiments as representative examples, as the base material that can be used as a support in the present invention, any conventionally known base material such as transparent or opaque can be used. Examples of suitable transparent base materials include polyester resin, diacetate-1.
Examples include films or plates of resins such as triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride resins, polyimide resins, cellophane, celluloid, and glass plates. Preferred examples of the opaque substrate include general paper, cloth, wood, metal plate 1 synthetic paper, and the above-mentioned transparent substrates treated to make them opaque by known means.

Preferably, such a substrate has a thickness of about 10 to 200 μm.

In the present invention, the ink retaining layer provided on the thickening material is mainly formed from a hydrophilic material that can accept water-based ink, and preferred examples of such materials include albumin, gelatin, and casein. , starch, cationic starch, Arabico J1, natural resins such as sodium alginate, polyamide, polyacrylamide,
Polyvinylpyrrolidone, quaternized polyvinylpyrrolidone,
Synthetic resins such as polyethyleneimine, polyvinylpyricillium halide, melamine resin, polyurethane, carboxymethyl cellulose, polyvinyl alcohol-modified polyvinyl alcohol, polyester, polyacrylic liquor, etc. are mentioned, and one or more of these materials can be used as desired. used.

Furthermore, in order to reinforce the strength of the ink retaining layer and/or improve the adhesion with the base material, SBR latex, NBR latex, polyvinyl formal, polymethyl methacrylate, polyvinyl butyral, polyacrylonitrile, polyvinyl chloride may be added as necessary. , polyvinyl acetate, phenol resin, alkyd resin, etc. may be used in combination.

As a method for forming such an ink retaining layer, a coating liquid is prepared by dissolving or dispersing the polymers listed in (-) in an appropriate solvent, and the coating liquid is prepared by:
For example, it is preferable to apply the coating onto the Omurakami using a known method such as a roll coating method, a rod bar coating method, an air knife coating method, a spray coating method, etc., and then dry it immediately. By known methods such as heat stretching method and T-die method,
A method of forming a single ink-retaining layer so that the ink-retaining layer also has the function of a support, or laminating the sheet to the above-mentioned substrate, by hot-melt coating with a polymer material. An ink retaining layer may be formed on the base material l- by a method or the like.

The thickness of the ink retaining layer formed in this manner may be within a range capable of retaining ink, and may vary from 0.1 p.m. to 0.1 p.m. There is no particular limitation as long as there is m. Practically speaking, 0.5 to 30 JLm is suitable.

The ink permeable layer used in the present invention and which mainly characterizes the present invention is made of natural or synthetic resin and has a thickness of 10 p.m., which is provided on the ink retaining layer formed as described above. m or less, and when a droplet of ink is attached to the surface, the contact area is quickly increased (e.g., for several seconds) to the extent that the droplet does not overlap excessively with other droplets adjacent to each other. (within)
Expand your eyes. It has the function of promoting the penetration of ink into the ink holding layer and the reception of the floating ink in the ink holding layer.

The inventor of the present invention conducted intensive research to impart the above-mentioned functions to the ink-retaining layer, and unexpectedly found that the ink-retaining layer had a hydrophilicity comparable to or of the same degree as the polymer constituting the ink-retaining layer. It has been found that the function described in item 1- can be easily achieved by forming a thin layer with a thickness of 1 Op,m or less from an inferior polymer. Like this
J: It was truly surprising that the function was also achieved with thin films of polymers that, for example, have no or little solubility in water.

The ink-permeable layer having the functions described in the following is made of a polymer with hydrophilicity comparable to or relatively inferior to that of the polymer material forming the ink-retaining layer, and has a thickness of at least 10 pLm, preferably about 0.1 to 5 μm. This was achieved by forming a thin film of

Polymeric materials useful in forming such thin layers include:
Homopolymers or copolymers made of vinyl acetate, acrylic esters, ethyl chloride, vinyl chloride, and other vinyl monomers, and polymers made of vinyl monomers such as those described above and various hydrophilic vinyl monomers;
Polymers such as vinylon, polyurethane, cellulose derivatives, polyester, polyamide, and the above-mentioned wood-philic polymers for forming an ink-retaining layer, either singly or in combination, have hydrophilicity comparable to or inferior to that of the ink-retaining layer. It is preferable to select it as such.

Further, the selected polymer may be a solution in an organic solvent, but it is preferably used in the form of an emulsion in an aqueous medium, an organic solvent, or a fine dispersion in an aqueous medium.

When used as an organic solvent solution, it is preferable to use a relatively thin solution or a concentration such that the layer that is formed falls within the above range.

The method for forming the ink permeable layer using the material described in 1-1 can be the same as the method for forming the ink retaining layer described above.

In the recording material of the present invention having the basic structure as described in 2 above, the thickness of the ink permeable layer is 10 μm or less, and the hydrophilicity thereof is comparable to or inferior to the hydrophilicity of the ink retaining layer. Nevertheless, the recording material of the present invention has significantly improved ink receptivity and ink fixing properties compared to conventional recording materials without such an ink permeable layer. is surprising. Although the theoretical basis thereof is currently unknown, according to the inventor's deep imagination (the present invention is not limited by such deep imagination), the ink permeable layer is It is not necessarily a continuous film, but the ink-permeable layer has countless microscopic gaps that allow the water-based ink to penetrate into the ink-retaining layer, and its surface is microscopically irregular, resulting in the formation of an adhesive layer. Is the ink droplet basic? It is thought that the ink absorbency and fixing properties of the ink retaining layer are significantly promoted by diffusing on the surface and expanding their contact area. Furthermore, in the recording material of the present invention, the ink permeable layer is formed from a polymer with hydrophilicity of the same level or lower than that of the ink retaining layer as a thin layer of 10 pLm or less, so that the ink adhering to the surface is , it does not remain in the ink permeable layer with low ink retention ability, but quickly permeates through the ink permeation layer and is retained in the ink retention layer with high ink retention ability.
It will be established. In addition, the use of less hydrophilic polymers can prevent the received ink from leaching to the surface and contaminating equipment, operators, or the surrounding area, even in high-temperature, high-humidity environments. The surface will not become sticky under high humidity.

The following is the basic structure of the present invention. In an embodiment in which the recording material of the present invention is translucent, a translucent material is used as the base material, and the ink retaining layer and the ink permeable layer are formed. In this case, it is necessary to ensure that these layers do not impair the translucency. However, to the extent that its translucency is not impaired,
For example, silica, clay, talc, diatomaceous, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, synthetic zeolite, alumina, zinc oxide, lithopone, sachin why! Fillers such as * can also be dispersed in the ink retaining layer.

In the present invention, sufficient light transmittance means that the recording material has a linear light transmittance of at least 2% or more, and preferably a linear light transmittance of 10% or more.

If the linear light transmittance is 2% or more, it is possible to project and observe the recorded image onto a screen using OHP, for example, and in order to clearly observe the details of the recorded image,
It is desirable that the linear light transmittance is 10% or more.

The linear transmittance T (%) here refers to the amount of light incident perpendicularly to the sample, transmitted through the sample, and at least 8
The spectral transmittance of the straight light that passes through the light-receiving side slit located on the extension line 1- of the incident optical path separated by c+n or more and is received by the detector is measured using a side light such as a 323-type Hitachi self-recording spectrophotometer (manufactured by Hitachi, Ltd.). The Y value of the color tristimulus value is determined from the measured spectral transmittance using the following formula.

T=Y/Y, X100 (1) T; Linear transmittance Y; Y value Y of the sample. Y value of Ni blank Therefore, the straight light transmittance referred to in the present invention is for straight light, and the diffuse light transmittance (an integrating sphere is provided behind the sample to determine the light transmittance including diffused light). and opacity (
The white and black backings are placed on the back of the sample and the ratio is calculated. ), which evaluates translucency using diffused light.

Since the problem with devices that use optical technology is the behavior of straight-line light, it is necessary to evaluate the translucency of the recording material to be used in these devices. Determining the light index is particularly important.

For example, when observing a projected image on an OHP, in order to obtain a clear and easy-to-see image with high contrast between recorded and non-recorded areas, the non-recorded areas in the projected image must be bright, that is, the straight line of the recording material. A certain amount of light transmittance 1-
It is required that the standards are met. In an OHP test chart test, in order to obtain an image suitable for the above purpose, the in-line transmittance of the recording material is 2% or more, and to obtain a clearer image, it is preferably 10%. The ratio is required to be less than -1-, and more preferably 50% or more. Therefore, a recording material suitable for this purpose must have an in-line transmittance of 2% or more.

Further, in an embodiment in which the recording material of the present invention is opaque, an opaque material may be used for at least one layer among the base material, the ink retaining layer, and the ink permeable layer.

The method of forming each layer used in this embodiment is the same as in the transparency embodiment described above.

In this opaque embodiment, when forming the ink retaining layer and the ink permeable layer, a large amount of the filler is used to the extent that film forming properties are not impaired, and further excellent ink receptivity and fixing properties are promoted. be able to.

The present invention has been described above by illustrating typical aspects of the recording material of the present invention, but of course the recording material of the present invention is not limited to these aspects. In addition, in any embodiment, the ink retaining layer contains a dispersant, fluorescent dye, p
Various known additives such as H regulators, antifoaming agents, lubricants, preservatives, and surfactants can be included.

Note that the recording material of the present invention does not necessarily have to be colorless, and may be a colored recording material.

As explained above and as demonstrated in the Examples below, the recording material of the present invention as described above has significantly improved ink reception and fixation, and for example, in the case of monochrome as well as full color. When recording, there is no dripping or oozing of the recording liquid even if different colored recording liquids adhere to the same spot repeatedly within a short period of time, resulting in high-resolution, clear images with excellent color development. can get. Furthermore, when using an optical device such as a slide or OHP to project a recorded image onto a screen, etc. for observation, attached ink droplets are more likely to interfere with other adjacent areas than with conventional recording materials. Since the image is magnified and fixed to such an extent that it does not overlap excessively, the transmitted light becomes even more uniform, providing a projected image with excellent uniform density. Furthermore, it can be suitably applied to uses other than conventional surface image observation, such as a color separation plate when creating a positive plate for color printing, or a CMF used for color displays such as axillary crystals.

Hereinafter, the method of the present invention will be explained in more detail according to Examples. In addition, the term "part" in the text refers to the landing standard.

Example 1 A polyethylene terephthalate film (manufactured by Toshi) with a thickness of 100 pm was used as a translucent base material, and coating liquid A having the following composition was applied onto this film so that the film thickness after drying was 10 #.
Apply by bar coater method to obtain Lm and heat at 60°C.
The ink retaining layer was formed by drying for 20 minutes.

Next, the following coating liquid B is applied onto the ink retaining layer so that the dry film thickness becomes IILm, and dried at 60° C. for 15 minutes to form an ink permeable layer. I got the material.

Coating liquid AMI composition: Water-soluble acrylic resin (Korgum HW-7, manufactured by Showa Kobunshi) 20 parts Polyvinyl alcohol (PVA-420, manufactured by Kuraray) 5 parts water
75
Part Coating Liquid B Composition: Tree-friendly urethane resin (Tricoat G, manufactured by Taiho Industries) Io part Acetone 90 parts The recording material of the present invention thus obtained was colorless and transparent.

Example 2 A recording material of the present invention was obtained in the same manner as in Example 1 except that art paper was used as the base material.

Example 3 A polyethylene terephthalate film (manufactured by Music University) with a thickness of 100 p and m was used, and coating liquid A having the following composition was applied to this film l- using a bar coater so that the film thickness after drying was 100 μm. The ink-retaining layer was formed by coating the ink by applying the same method and drying at 80° C. for 1 hour. Next, coating liquid B below was applied to the ink retaining layer 1- so that the dry film thickness was 3 cm, and dried at 80°C for 20 minutes to form an ink permeable layer. The ink retaining layer and the ink transmitting layer were both peeled off from the phthalate filtrate to obtain a translucent recording material of the present invention.

Coating liquid A composition: Polyvinyl alcohol (PVA-220 manufactured by Kuraray) 5 parts Polyvinylpyrrolidone (PVP K-90GAF manufactured) 5 parts water
90
Part Coating liquid B composition: Carboxymethyl cellulose (Celogen BS Dai-T Gyo Seiyaku Co., Ltd.) 2 parts Water
9
8 parts Example 4 The same film as used in Example 1 was used as the base material, and coating solution A having the following composition was applied to this base material using a bar coater so that the film thickness after drying was 8 pL11. The ink retaining layer was formed by applying the ink with a horn and drying at 50° C. for 20 minutes. Next, Coating Solution B below was applied onto the ink retaining layer so that the dry film thickness was 2Ii, m, and heated at 70°C.
The mixture was dried for 10 minutes to form an ink permeable layer, thereby obtaining an opaque recording material of the present invention.

Coating liquid A composition: Hydroxyethyl cellulose (HECAH-15, manufactured by Fuji Chemical) 5 parts water
9
5 parts Coating liquid B composition: Acrylic resin (Guikaratsuku S-1235, Daido Kasei Kogyo type) 5 parts Ethanol 95 parts Comparative Examples 1 and 2 Same as Examples 1 and 3 except that no ink permeable layer was formed. A recording material for comparison was prepared using the same method.

Comparative Examples 3 to 4 In Examples 1 and 4, the thickness of the ink permeable layer was set to 20
Comparative recording materials were prepared in the same manner as in Examples 1 and 4, except that VL+1 and 15 m2 were used.

The following four types of ink were used on the recording materials of Examples and Comparative Examples described in 1-1. Vibrator drive voltage 7
Inkjet recording was performed using a recording device having a voltage of 0 V and a frequency of 3 KHz.

Yellow ink (composition) cr, Direct Yellow 86 2 parts N-methyl-
2-pyrrolidone 10 parts diethylene glycol
20 parts polyethylene glycol #200 15 parts water 5
5 parts Magenta ink (composition) CA, Acid Red 35 2 parts N-methyl-
2-pyrrolidone 10 parts diethylene glycol
20 parts polyethylene glycol #200 15 parts water 5
5 parts cyan ink (composition) CA, Dyref i Blue 86 2 parts N-methyl-
2-pyrrolidone 10 parts diethylene glycol
20 parts polyethylene glycol #200 15 parts water 55
Part black ink (composition) CA, food black 2 2 parts N-methyl-
2-pyrrolidone 10 parts diethylene glycol
20 parts polyethylene glycol #200. 15 parts water
Table 1 shows the evaluation results of the recording materials of Examples and Comparative Examples. Each evaluation item in Table 1 was measured according to the following method.

(1) Ink fixation time was measured by leaving the recording material at room temperature after recording and measuring the time taken for the ink to dry and stop adhering to the finger when touching the recorded image with the finger.

(2) The dot density was measured for black dots using Sakura Microdensidometer PDM-5 (manufactured by Konishiroku Photo Industries) by applying JIS K 7505 to printed microdots.

(3) OHP suitability was measured as a representative example of optical equipment, and the recorded image was projected onto a screen using OHP.
Judgment is made by visual observation. 0 indicates that the non-recorded area is bright, the OD (optical density) of the recorded image is high, and a clear and easy-to-see projected image with high contrast is obtained, while the non-recorded area is slightly dark and the recorded image is 0. If the OD of the image is rather low and the line with a pitch width of 0.5 mm and a thickness of 0.25 mm cannot be clearly distinguished, Δ is used. sa0
．． A case where the 3 mm line could not be clearly distinguished or a case where the non-recorded area and the recorded image could not be distinguished was rated as "x".

(4) Linear light transmittance is calculated using a 3-part 3-type Hitachi self-recording spectrophotometer (1
The distance from the sample to the light-receiving side was kept at about 9 cm, and the spectral transmittance was measured using the above formula (1).

(Margins below) - Angle poly 1 ≦ 1 - (- 1 Example 2 ↓ Name A Ink fixing time 20°C 65 stations H15 seconds 15 seconds 45 seconds
15 seconds 20℃ 85 canter H15 seconds 15 seconds 4
5 seconds 30 seconds straight light transmittance 78% 80
% 81% dot density
0.9 1.2
1.0 1.0 store” LyojL Ox
o OO platform warehouse 1 2 夛 4 1Z long fixation temperature 20℃ 65 stations H1 minute 1 minute 3 minutes
20℃ for 30 minutes or more 85B) 1 Unable to record Unable to record 15 minutes 30 minutes Straight-line transmission rate 80% 78% 70%
78% dot +-a word level
1.0, 1.0
0.8 1.00HP suitability o o
o.

41f revision applicant: Canon Co., Ltd. Sozai 5: Ichitosaku 2-79-75 Suigacho 11 official documents with procedures (voluntary) September 1985) 81]

Claims (1)

[Claims] A recording material comprising an ink retaining layer and an ink permeable layer, the ink permeable layer having a thickness of 10 μm or less.