JPS62233283A - Recording medium - Google Patents

Abstract

PURPOSE:To prevent anchor coat layers from blocking to each other in manufacture of a recording medium, by a method wherein the anchor coat layers provided on the both faces of a substrate have different physical properties. CONSTITUTION:Anchor coat layers provided on both sides of a substrate consist of a material having a high adhesion to both the substrate and the ink accepting layer. The material is preferably made of a water-soluble or hydrophilic polymer because generally the substrate is hydrophobic and the ink accepting layer is hydrophilic. In addition, it is desirable that the anchor coat layers of different physical properties are formed on both faces of the substrate without replacement of a coating liquid. For example, coating liquid layers using the same coating liquid are applied on the both faces under different forming conditions such as drying and crosslinking conditions, the coating liquid layers are made of the materials using the same main component but added with different additives to vary the anchor layers of both faces in composition, or the like. As materials for the ink accepting layer and a curling preventive layer formed on the anchor coat layers of both faces, water-soluble or hydrophilic polymers of physical properties being similarly affected by the change in temperature and humidity are preferably used.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a recording material that is useful for various recording methods, and is particularly suitable for inkjet recording and that does not curl under a wide range of environmental conditions. The present invention relates to a recording material that can be suitably used without any problems.

(Prior Art) Inkjet recording methods include various ink (recording liquid) ejection methods, such as an electrostatic suction method, a method that applies mechanical vibration or displacement to the ink using a piezoelectric element, and a method that heats the ink to foam it. This method utilizes the pressure to generate and fly ink droplets, and some or all of them adhere to a recording material such as paper to perform recording, but it generates little noise and It is attracting attention as a recording method that allows high-speed printing and multicolor printing.

Ink for inkjet recording is mainly composed of water for safety and recording characteristics, and polyhydric alcohols are added to prevent nozzle clogging and improve ejection stability. In many cases.

The recording material used in this inkjet recording system has conventionally been a recording material consisting of a base material called ordinary paper or inkjet recording paper on which a porous ink-receiving layer is provided.

However, as the performance of inkjet recording apparatuses increases and becomes more widespread, such as faster recording speeds and multicolor recording, more advanced and wide-ranging properties are being required of recording materials. That is, in order to obtain a high-resolution, high-quality recorded image, it is necessary that ink reception be as quick as possible, that ink bleed be appropriate, and so on.

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 has improved and become more widespread, recording materials suitable for purposes other than surface image observation have become available. is becoming required.

Applications of recording materials other than surface image observation include those used to project recorded images onto a screen etc. using optical equipment such as slides and OHP (overhead projectors) for observation, and color printing. Examples include color separation plates used to create positive plates, 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.

However, since the ink used in conventional inkjet recording materials is water-based, the ink-receiving layer is made mainly of water-soluble to hydrophilic polymers so that the applied ink can be received as quickly as possible. is formed.

Therefore, the dimensions of the ink-receiving layer change due to changes in the surrounding conditions of a recording material having such an ink-receiving layer, especially changes in temperature and humidity conditions, and as a result, various curls occur. When such curling occurs, the feeding and ejection of the recording material to the recording device is obstructed, and in devices that record by wrapping the recording material around a drum, there is a serious problem that the wrapping does not work properly and recording is not possible. Occur.

Furthermore, when visually observing a recorded image, it appears curled, and when observed using an optical device such as an OHP, problems arise such as the image not being accurately focused on the screen. .

In order to prevent these curls, attempts have been made to provide an anti-curl layer on the back side of the substrate in recording materials for inkjet systems that have a substrate and an ink-receiving layer.

The curling phenomenon occurs because the ink-receiving layer causes a difference in expansion/contraction rate between the ink-receiving layer and the base material due to changes in the surrounding environment, particularly changes in temperature and humidity. Therefore, by providing an anti-curl layer with the same physical properties as the ink-receiving layer on the opposite side of the ink-receiving layer provided on the base material, the ink-receiving layer and the anti-curl layer on the front and back of the base material can be protected against environmental changes. The expansion and contraction forces are the same, and the forces on the entire recording material are balanced around the base material, thereby preventing the recording material from curling.

Therefore, it is preferable that the ink-receiving layer and the curl prevention layer are formed from materials having the same physical properties.

On the other hand, generally when providing an ink-receiving layer or an anti-curl layer on a base material, an anchor is placed between the base material and the ink-receiving layer or anti-curl layer for the purpose of improving adhesion to the base material. Each layer is provided with a thickness of about 0.1 to 10 pm. That is, it is preferable that the front and back sides of the base material have the same structure made of the same components.

The anchor coat layer and ink receiving layer (curl prevention N) as described above are coated layer by layer on the front and back sides of the base material.

(1) Anchor coat layer → Anchor coat layer → Ink receptive layer (anti-curl layer) → Anti-curl layer (ink receptive layer) (2) Anchor coat layer → Ink receptive layer (anti-curl layer) → Anchor coat layer → Anti-curl layer (ink-receiving layer), but in order to improve workability in manufacturing (
It is easy to imagine that the form 1) is used.

That is, in the form (1), the coating liquid is replaced twice on the coater, whereas in the form (2), it is replaced four times.

For the reasons mentioned above, the coating method (1) is generally used when providing the anchor coat layer and the ink receiving layer on the front and back sides of the base material. However, if the anchor coat layer provided between the base material and the ink-receiving layer is the same as the curl prevention layer provided between the base material and the anti-curl layer, the anchor coat layer and the anchor coat layer will not roll together. When forming the ink-receiving layer (curl prevention layer), they may come into contact with each other, causing blocking, and may not be able to be rewound when forming the ink-receiving layer (curl prevention layer), or may damage each other's anchor coat layers. This phenomenon occurs and becomes a very serious problem in coating.

Therefore, an object of the present invention is to easily provide a recording material in which the anchor coat layers do not block each other during the production of the recording material as described above.

As a result of intensive research to achieve the object of the present invention as described above, the present inventors have found that the object of the present invention has been achieved by forming the anchor coat layers provided on the front and back sides of the base material as layers with different physical properties. It was found that the shortcomings of the technology were resolved.

(Disclosure of the Invention) That is, the present invention provides a recording material comprising a base material, an anchor coat layer provided on the front and back sides of the base material, and an ink receiving layer and an anti-curl layer provided on each of the anchor coat layers. , is a recording material characterized in that the anchor coat layers provided on the front and back sides of the above-mentioned base material have different physical properties.

Next, to explain the present invention in more detail, as the base material used as the support for the ink receiving layer in the present invention, any conventionally known base material such as transparent or opaque can be used, and is suitable as a transparent base material. Examples include films or plates of polyester resins, diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride resins, polyimide resins, cellophane, celluloid, and glass plates. can be given. Preferred opaque substrates include, for example, ordinary paper, cloth, wood, metal plates, synthetic paper, and the like, as well as the above transparent substrates treated to make them opaque by known means. Such substrates generally range from 10 to 2,0004 m
It is preferable that the thickness be approximately the same.

Further, the anchor coat layer provided on the front and back sides of the base material as described above is preferably formed from a material that has high adhesiveness to both the base material and the ink receiving layer, and generally the base material is hydrophobic. On the other hand, since the ink-receiving layer is wood-philic, it is preferably formed from a water-soluble to hydrophilic polymer material having both of these properties at the same time. Examples of such preferred water-soluble to hydrophilic polymers include, for example, Polymers made by partially crosslinking conventionally known water-soluble to hydrophilic polymers to make them water-insoluble, or polymers made by partially making hydrophilic a conventionally known hydrophobic polymer, etc., as examples for forming the ink-receiving layer of This is preferable. Further examples of preferred polymers include crosslinkable polymers having reactive groups, such as incyanate-modified polyester resins having a small amount of free incyanate groups, incyanate-modified polyurethane resins, acrylic resins having epoxy groups, and methylol groups. Examples include amine resins having

Still other preferable examples include polar group-containing polymers having hydrogen bondable groups 1 that increase adhesion, such as hydroxyl groups, carboxyl groups, sulfonic acid groups, and amino groups.

In the present invention, anchor neat layers are formed on the front and back sides of the base material from one or more materials, but in the present invention, the anchor coat layers on the front and back sides of the base material formed from these materials have different physical properties. It is necessary.

One example of the method is to select two or more materials from the materials described above and form the respective anchor coat layers from different materials. When forming anchor coat layers with different physical properties on the front and back sides of a base material using this method, the steps are: Anchor coat layer (front) → Anchor coat layer (back) Ink receiving layer (anti-curl layer) → Anti-curl FF+ (ink-receiving layer), and since the materials for forming the front and back anchor coat layers are different, there is a disadvantage in the process that the coating liquid must be replaced every time one layer is formed.

Therefore, a preferred method of forming the anchor coat layer in the present invention is to form front and back anchor coat layers having different physical properties without substantially changing the coating solution. An example of such a preferred method is to use the same coating solution,
Method 1: Forming front and back layers with different physical properties by varying the drying conditions, crosslinking conditions, and other film forming conditions of the coating liquid layers coated on the front and back sides.1 Method of forming the front and back anchor coat layers using the same main components. Methods such as using a material and changing the composition of the material by adding a different additive to it, and changing the composition of the material by changing the amount of the same additive added are used. By employing such a method, it is possible to eliminate the disadvantage in the process of replacing the coating liquid every time the front and back anchor coat layers are formed.

As a method for forming such an anchor coat layer,
A coating solution is prepared by dissolving or dispersing the anchor coat layer forming material as described above in an appropriate solvent, and the coating solution is coated with a coating method such as a roll coating method, a rod bar coating method, a spray coating method, an air knife coating method, etc. It can be obtained by coating it on a substrate by a known method and then quickly drying it. Such an anchor coat layer is generally formed to a thickness of about 0.01 to 10 JLm, preferably about 0.1 to 3 JLm.

In the present invention, an ink-receiving layer and an anti-curl layer are formed on the above-mentioned front and back anchor coat layers, but such an ink-receiving layer and an anti-curl layer have physical properties that are subjected to the same effect on changes in temperature and humidity. If it has
They do not necessarily need to be formed from the same material, but may be formed from materials with different compositions, similar to the formation of the anchor coat layer described above.
It goes without saying that the coating solution may be formed without replacing the coating solution, and that it may be formed from the same material.

Generally, water-soluble to hydrophilic polymers are preferred as materials for forming the ink-receiving layer or anti-curl layer, and preferred examples of such polymers include albumin, gelatin, casein, starch, cationic starch, and gum arabic. , natural resins such as sodium alginate, polyvinyl alcohol, polyamide, polyacrylamide,
Examples include synthetic resins such as quaternized polyvinylpyrrolidone, polyethyleneimine, polyvinylpyricillium halide, melamine resin, polyurethane, polyester, and sodium polyacrylate, and one or more of these materials may be used in combination if desired.

Furthermore, in order to reinforce the strength of these layers and/or improve the adhesion with the anchor coat layer, S may be added as necessary.
Resins such as BR latex, NOR latex, polyvinyl formal, polymethyl methacrylate, polyvinyl butyral, polyacrylonitrile, polyvinyl chloride, polyvinyl acetate, phenolic resin, and alkyd resin may be used in combination.

In addition, in order to improve the ink absorbency of the ink receiving layer, various fillers such as silica, clay, etc. are added to the ink receiving layer.
Fillers such as talc, diatoms, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, synthetic zeolites, alumina, zinc oxide, lithopone, satin white, plastic pigments, etc. can also be dispersed in the ink-receiving layer.

The method for forming the ink-receiving layer and the anti-curl layer from the above materials may be the same as the method for forming the anchor coat layer described above, and the thickness of the ink-receiving layer and the anti-curl layer to be formed is generally is about 0.11-1O0J
Lm, preferably about 3 to 301 Lm.

The present invention has been explained 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. Also, the front and back anchor coat layers, ink receiving layers,
The anti-curl layer can contain various known additives such as dispersants, fluorescent dyes, pH adjusters, antifoaming agents, lubricants, preservatives, and surfactants.

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

The recording material of the present invention as described above has an ink-receiving layer and a curl prevention layer formed on both sides thereof, which behave in the same way with respect to changes in temperature and humidity. Also, it does not curl even when the ambient temperature and humidity change, both when observing the image after recording and during storage, etc., and it solves the various problems that occurred in the past, especially when feeding and discharging paper during recording. Moreover, since no curling occurs when the image is observed after recording, even when used as a document for OHP or the like, the projected image is not distorted or disturbed, and an accurate transparent image is formed.

In addition, the recording material of the present invention can be manufactured by forming an anchor coat layer and then winding it onto a roll.
Since the physical properties of the front and back anchor coat layers are different, the problem of the anchor coat layer being damaged as a result of blocking is also solved, and a high quality recording material is advantageously provided in terms of the process.

Next, the present invention will be explained in more detail by giving Examples, Comparative Examples, and Usage Examples. Note that 1 part or % in each sentence is based on weight unless otherwise specified.

Example 1 A polyethylene terephthalate film (manufactured by Toshi) with a thickness of 100 μm was used as a translucent base material, and the following coating solution A was applied to the surface of this film as an anchor coat layer for an ink-receiving layer so that the dry film thickness was lILm. It was coated by the Percoater method as described above and dried at 130°C for 1 minute.

1 plant foot L polyester CAD-78H5, Toyo Morton acid, 10
% toluene/methyl ethyl ketone solution) 100 parts incyanate (CAT-10, Toyo Morton acid, 10
% toluene/methyl ethyl ketone solution) 20 parts Next, the following coating solution B was applied as an anchor coat layer for the anti-curl layer to the back of the film using a bar coater method so that the dry film thickness was lpm, and the mixture was heated at 120°C for 2 minutes. Dry.

``Nuri'' ``Nuri'' Polyester (AD-78H5, Toyo Morton Acid.

10% toluene/methyl ethyl ketone solution) 100 parts incyanate (coronated, 10% toluene/methyl ethyl ketone solution manufactured by Nippon Polyurethane Industries)
25 parts Next, as an anti-curl layer, the following coating solution C was applied on the anchor coat layer for the anti-curl layer using a bar coater method so that the dry film thickness was 8 uLm,
It was dried at 80°C for 10 minutes.

Next, as an ink-receiving layer, the following coating liquid C was coated on the anchor coat layer for the ink-receiving layer by a bar coater method so that the dry film thickness was 81 parts, and was dried at 80° C. for 10 minutes.

1 Kou S Polyvinyl alcohol (PVA-220, manufactured by Kuraray) 5
Polyvinylpyrrolid (PVPK-90, manufactured by GAF)
5 parts water 9
The recording material of the present invention was obtained in such a manner that 0 or more copies were prepared.

Example 2 A polyethylene terephthalate film (manufactured by Toshi) with a thickness of 75 ILm was used as a translucent base material, and the following coating solution A was applied to the surface of this film as an anchor coat layer for an ink-receiving layer so that the dry film thickness was Igm. It was coated on a cloth using a percoater method and dried at 130° C. for 1 minute.

1 process: 100 parts of polyester (Vylon 203, manufactured by Toyobo, 10% toluene/methyl ethyl ketone solution), isocyanate (Coronate L, Nippon Polyurethane 2)
(to% toluene/methyl ethyl ketone solution)
90 parts Next, the following coating solution B was applied as an anchor coat layer for an anti-curl layer to the back side of the film using a percoater method so that the dry film thickness was 171 m.
It was dried at 110°C for 3 minutes.

1 engineering J polyester (Epikote 1007, shell acid, 10%
Butyl acetate/toluene/methyl ethyl ketone solution)
100 parts incyanate (dismodulated, manufactured by Bayer, 10% butyl acetate/toluene/methyl ethyl ketone solution) 85 parts Next, as an anti-curl layer, apply the following coating solution C on the anchor coat layer for the anti-curl layer to a dry film thickness of 5 g. Coated by bar coater method so that

It was dried at 100°C for 8 minutes.

Robust Wataru S Polyvinylvinylene (PVP-Ni-90, made by GAF) 10 parts water
90 parts Next, as an ink-receiving layer, the following coating liquid was coated on the anchor coat layer for the ink-receiving layer by a bar coater method so that the dry film thickness was 5 μm, and dried at 100° C. for 8 minutes.

1 Polyvinyl alcohol (PVA-420, manufactured by Kuraray) 1
0 parts water
A recording material of the present invention was obtained from 9 o parts as described in 2 above.

Example 3 A polyethylene terephthalate film (Toshi W) with a thickness of 75 ILm was used as a translucent base material, and the following coating solution A was applied to the surface of this film as an anchor coat layer for an ink-receiving layer so that the dry film thickness was IILm. It was coated using a bar coater method and dried at 100° C. for 1 minute.

Polyester (Byron 205, Toyobo Co., Ltd., 10% toluene/methyl ethyl ketone solution) 100 parts Incyanate (Coronate L, Nippon Polyurethane Kogyo Co., Ltd., 10% toluene/methyl ethyl ketone solution)
80 parts Next, the above coating solution A was applied as an anchor coat layer for an anti-curl layer to the back side of the film using a bar coater method so that the dry film thickness was lpm,
It was dried at 140°C for 1 minute.

Next, coating liquid C used in Example 2 was coated on the anchor coat layer for an anti-curling layer as an anti-curling layer by a bar caulking method so that the dry film thickness was 5 lm,
Let dry for a minute.

Next, the coating liquid C used in Example 2 was coated on the anchor coat layer for the ink-receiving layer as an ink-receiving layer by a barniter method so that the dry film thickness was 5 Bm.
Let dry for a minute.

The recording material of the present invention was obtained as described above.

Comparative Example 1 A comparative recording medium was prepared in the same manner as in Example 1 except that the anchor coat layer for the anti-curl layer was formed using coating liquid A used in Example 1. I got the material.

Comparative Example 2 A comparative recording material was prepared in the same manner as in Example 1, except that the anchor coat layer for the ink-receiving layer in Example 1 was formed using coating liquid B used in Example 1. I got the material.

Comparative Example 3 A comparative recording material was prepared in the same manner as in Example 2, except that the anchor coat layer for the anti-curl layer was formed using coating liquid A used in Example 2. I got the material.

Comparative Example 4 A comparative recording material was prepared in the same manner as in Example 2, except that the anchor coat layer for the ink-receiving layer was formed using coating liquid B used in Example 2. I got the material.

For the recording materials of the above Examples and Comparative Examples, the following 4
On-demand inkjet recording head that uses seed ink to eject ink using a piezoelectric vibrator (discharge orifice diameter 60JLm, piezoelectric vibrator drive voltage 70JLm)
Inkjet recording was carried out using a Q device having a frequency of 2 KHz).

Charcoal! (Composition) C, 1, Direct Yellow 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 parts Li21 (composition) C, 1, Acid Red 35 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
7s part Li21 (composition) C, 1, Direct Blue 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
7s club! 177 (Composition) C, 1, Food Black 2 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 copies The evaluation results of the recording materials of the Examples and Comparative Examples are shown in Table 1. Each evaluation item in Table 1 was measured according to the following method.

(1) Manufacture suitability is determined by one-layer coating using a reversible coater, etc.
When manufacturing a recording material by applying, drying and winding, the anchor neat layer for the ink-receiving layer and the anchor coat layer for the anti-curl IE layer come into contact during the first winding, and the ink-receiving layer Or, when unwinding to provide an anti-curl layer, it was observed that the anchor coat layers blocked each other and unwinding was not performed smoothly, or that the anchor coat layers peeled off from each other. There was no blowing or kinging between the anchor coat layers, smooth unwinding, and no peeling of the anchor coat layers from each other was rated 01, and cases where the anchor coat layers peeled from each other even partially were rated X.

(2) For curls, temperature: 20℃, humidity: 65%RH
Evaluation was made by determining the curl curvature radius when the recording material was hung vertically under the following environmental conditions. The radius of curvature of a plus side curl (a curl in which the ink-receiving layer side is convex) is indicated by a (+) symbol, and the minus side is indicated by a (-) symbol.

(3) Ink fixation time is determined by leaving the recording material after recording at room temperature (20°C, 65% RH) and touching the recorded image with your finger, the ink will dry and will no longer stick to your finger. The time was measured.

(4) Dot density can be determined using Sakura Microdensidometer PD by applying JISK7505 to printed microdots.
The black dots were measured using M-5 (manufactured by Konishiroku Photo Industry Co., Ltd.).

(5) 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, the pitch width is 0, the 5s layer, and the line of thickness 0.25 m1 cannot be clearly distinguished, Δ, the non-recorded area is quite dark, the OD of the recorded image is quite low, the pitch width is 1+u+, and the line is sa0
, 3+a■ lines were not clearly distinguishable, or cases where the recorded image could not be distinguished from non-2QffB were designated as X.

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Claims (2)

[Claims] (1) A recording material consisting of a base material, an anchor coat layer provided on the front and back sides of the base material, and an ink receiving layer and an anti-curl layer provided on each of the anchor coat layers, provided on the front and back sides of the base material. A recording material characterized in that the anchor coat layers have different physical properties. (2) Claim No. (2) for inkjet system
The recording material described in item 1).