JPS62183383A - Producing of light-transmitting printed matter - Google Patents

Abstract

PURPOSE:To obtain a light-transmitting printed matter excellent in clearness, resolution and optical density of recorded images, by recording in a recording liquid on a recording material comprising a surface layer and an ink-holding layer, and transparentizing only the surface layer. CONSTITUTION:This method comprises a step of recording in a recording liquid on a recording material comprising a liquid-permeable surface layer and an ink-holding layer, the recording being conducted on the surface layer side of the recording material, and a step of transparentizing the surface layer. The transparentization after recording may be carried out by a method wherein resin particles constituting the surface layer are melted by heating to provide a uniform film. The melting temperature of the resin constituting the surface layer is set to be lower than the melting temperature of the ink-holding layer and the softening temperature of a base. Steps of providing the ink-holding layer and the surface layer on the base generally include a drying step, and the drying temperature is preferably not lower than 80 deg.C, so that the melting temperature of the resin constituting the surface layer must be not lower than the drying temperature.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the production of translucent prints using a recording liquid,
In particular, the present invention relates to a method for producing a translucent printed matter with excellent clarity of recorded images and ink absorbency.

[Conventional technology]

For example, writing with a fountain pen has been a common method for recording using a recording liquid for a long time, but recently, so-called inkjet recording methods have also appeared, and recording liquids are also used here.

The inkjet recording method generates small droplets of recording liquid using various operating principles, and performs recording by flying these droplets and adhering them to the recording material, which produces less noise and enables high-speed printing. , is attracting attention as a recording method characterized by its ability to print in multiple colors. Water-based recording liquids are mainly used for inkjet recording in terms of safety and recording suitability.

Conventionally, the recording materials used in this inkjet recording method have been ordinary paper, and recording materials such as paper with an ink-absorbing layer on top of the paper to improve ink absorption properties have been used. developed and used. In order to obtain high resolution and high quality recorded images in the inkjet recording method, these recording materials must: 1) absorb ink as quickly as possible; 2) absorb the ink as quickly as possible; 2) when ink dots overlap, 3) The diameter of the ink dot should not be larger than necessary. 4) The shape of the ink dot should be close to a perfect circle and the surrounding area should be smooth. 5) The density of the ink dot It is necessary that the ink satisfies the required performance as a recording material, such as having a high color density and not blurring the dot periphery; and 6) excellent ink color development.

In addition, until now, in inkjet recording, recording materials have been used to obtain recorded images for surface image observation, but as inkjet recording technology improves and devices become more widespread, applications other than inkjet recording materials have been used. For example, the recorded image is projected onto a screen using an optical device such as a slide or 0HP (overhead projector) for observation, contact printers, printing plates for printed circuit boards (photomasks), and colors used when making positive plates for color printing. Examples include decomposition plates and CMFs (color mosaic filters) for liquid crystal color displays.

Transparent negatives and positives used in optical instruments or devices that utilize optical technology are produced by taking a photograph of the recorded object or the object to be recorded, or directly recorded on a transparent recording material such as plastic film. However, by performing inkjet recording using an inkjet recording material that can be made transparent, the recording speed is increased, and it is also possible to produce high-quality, full-color prints with high resolution that can be used in optical equipment such as those mentioned above. A recorded image can be obtained. Therefore, in order to use it for such purposes, in addition to the performance required for the above-mentioned general recording material for inkjet recording, it is necessary to have transparency suitable for the intended use.

As the above-mentioned transparent recording material, a method is known in which a porous ink-receiving layer is provided on a transparent base material, an image is recorded by an inkjet recording method, and a print for transmitted light observation is obtained by performing a transparency treatment. It is being

Although the recording material used in this method has excellent ink absorbency, it has poor color development because the dye in the recording liquid partially aggregates after it becomes transparent. Furthermore, since the material constituting the porous ink-receiving layer itself does not have sufficient ink retention, after it becomes transparent, the ink remains in liquid form at the interface between the transparent substrate and the ink-receiving layer, causing image bleeding and It has drawbacks such as the tendency for the ink-receiving layer to peel off.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a translucent material that is particularly excellent in the clarity, resolution, and optical density of recorded images, and that is suitable for high-speed recording. The object of the present invention is to provide a method for creating sex prints.

Another object of the present invention is to provide a method for producing a translucent printed matter that is excellent in ink receptivity, water resistance, light resistance, blocking resistance, storage stability, etc. of recorded images.

Still another object of the present invention is to provide a method for producing a translucent print that does not cause peeling between the base material and the ink retaining layer in the ink recording section.

[Means for solving problems]

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

That is, the present invention includes a step of performing recording on a recording material having a surface layer having liquid permeability and an ink retaining layer using a recording liquid from the surface layer side of the recording material, and making the surface layer transparent. 1. A method for producing a translucent printed matter, comprising the steps of:

[For production]

The main feature of the present invention is that after recording is performed using a recording liquid on a recording material having a surface layer and an ink retaining layer, only the surface layer is subjected to a transparent treatment.

The recording material used in the present invention has a liquid-permeable surface layer,
It has the function of quickly absorbing and transmitting the recording liquid attached to its surface.

The absorption at this time is mainly due to wetting and permeation of the recording liquid into the surface layer, and compared to the diffusion and permeation of absorption in conventional ink absorbing layers using wood-philic polymers, the absorption speed is much faster. Are better.

On the other hand, a preferred embodiment that has liquid permeability is a porous structure with cracks inside the surface layer, but since such a structure is light diffusive, it is necessary to After this, it is necessary to perform a transparent treatment.

In this process of transparentization, the liquid-permeable surface layer material changes into a uniform structure with low light diffusivity, but the layer becomes transparent with the recording liquid or recording agent remaining in it. When this is done, it is difficult to obtain a clear image due to problems such as compatibility between the material constituting the liquid-permeable surface layer and the recording agent, and the recording agent aggregates non-uniformly.

Therefore, in the present invention, by providing an ink retaining layer in contact with the surface layer having liquid permeability, even after the surface layer is made transparent,
They discovered that it is possible to obtain clear images.

The ink retaining layer absorbs and retains the recording liquid temporarily absorbed by the surface layer, and the ink absorption speed may be lower than that of the surface layer, but the absorbing power must be greater than that of the surface layer.

Absorption in the ink holding layer is mainly by diffusion and penetration, and the recording agent is also uniformly dispersed, resulting in a clear image.

The relationship between demand diffusion permeation and leakage permeation is as follows: Absorption rate Diffusion Wetness Absorption power Diffusion > Wetness The present invention utilizes the advantages of diffusion permeation and wetness permeation.

Hereinafter, the present invention will be described in detail based on embodiments.

The recording material of the present invention includes a base material as a support, and absorbs substantially the recording liquid or recording agent formed on the support.
An ink retaining layer for capturing and formed on the ink retaining layer. It is composed of a surface layer that directly receives the recording liquid, has liquid permeability, and leaves virtually no recording agent behind.

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

As the base material used in the present invention, conventionally known materials can be used, and specifically, polyester resin, diacetate resin, and triacetate resin.

Examples include plastic films, plates, and glass plates such as polystyrene resin, polyethylene resin, polycarbonate resin, polymethacrylate resin, cellophane, celluloid, polyvinyl chloride resin, and polyimide resin.

In addition, since the present invention is to obtain a translucent printed matter, the base material must be transparent.

Furthermore, by selecting a base material having water resistance, abrasion resistance, and blocking resistance, it is possible to impart water resistance, abrasion resistance, and blocking resistance to the printed matter.

The liquid permeability of the surface layer constituting the recording material used in the present invention refers to a property that allows the recording liquid to pass through it quickly and does not substantially allow the recording material in the recording liquid to remain in the surface layer.

A preferred embodiment of the surface layer having liquid permeability is one having a porous structure having cracks and communicating pores inside the surface layer, and can be made transparent by heating, pressurization, a solvent, or the like.

The surface layer that satisfies the above characteristics is mainly composed of resin particles and a binder.

The resin particles used in the present invention are thermoplastic resins that are non-adsorbent to the recording material, and can be melted and made uniform using a resin or solvent that can be fused and made uniform by heating and/or pressure. Organic particles such as resin, for example, at least one resin powder and emulsion such as polyethylene, polymethacrylate, elastomer, ethylene-vinyl acetate polymer, styrene-acrylic copolymer, polyester, polyacrylic, polyvinyl ether, etc. Used as desired.

Note that the resin particles used in the present invention are not limited to the resin particles mentioned above, and may be any well-known material as long as it is non-adsorbent to the recording agent and can be made transparent. I do not care.

As with resin particles, it is necessary that the recording material is non-adsorbent.

As the preferred material for the stone material, any conventionally known material can be used as long as it has the above-mentioned functions.
Polyvinyl alcohol, acrylic resin, styrene-acrylic copolymer, ethylene-vinyl acetate copolymer, starch, polyvinyl butyral, gelatin, casein, ionomer, gum arabic, carboxymethyl cellulose amide, phenol, melanin, epoxy, styrene-butadiene rubber, etc. One or more of these resins can be used as desired.

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

The mixing ratio (weight ratio) of and the resin particles/binder is preferably in the range of resin particles/binder = 172 to 50/1, more preferably in the range of 3/l to 20/1. be.

If this mixing ratio is less than 172, the cracks and communication pores in the surface layer will become smaller and the recording liquid absorption effect will decrease. Furthermore, if the mixing ratio is 50/1 or more, the adhesion between the resin particles or between the ink retaining layer and the resin particles becomes insufficient, making it impossible to form a surface layer.

Although the thickness of the surface layer depends on the amount of recording droplets, it is preferably 1 to 200 gm, more preferably 3 to 50 gm.

Next, the non-porous ink holding layer that substantially captures the recording liquid or recording agent absorbs and captures the recording liquid that has passed through the surface layer, and substantially permanently retains the recording liquid.

The ink retaining layer needs to have a stronger ability to absorb recording liquid than the surface layer.

This is because if the absorbency of the ink-retaining layer is weaker than that of the surface layer, the green liquor applied to the surface of the surface layer will stagnate, causing the gap between the surface layer and the ink-retention layer to stagnate. At the interface, the recording liquid permeates and diffuses laterally within the surface layer. the result,
The resolution of the recorded image decreases, making it impossible to form a high-quality image.

Furthermore, the ink retaining layer needs to be light-transmissive. .

An ink retaining layer that satisfies the above requirements is soluble in a light-transmitting resin that adsorbs a recording agent and/or a recording liquid, and has a ma.
It is preferable that the light-transmitting resin is made of a transparent resin.

For example, when an aqueous recording system containing an acid dye or a direct dye is used as a recording agent, the ink retaining layer is made of a cationic resin having adsorption properties for the dye, such as a quaternized polyamine. and/or made of a wood-philic polymer that is swellable to an aqueous recording liquid.

The material constituting the ink retaining layer has the function of absorbing and trapping the recording liquid, forms a non-porous layer, and is sufficiently stable for transparency treatment after inkjet recording. It is not particularly limited as long as it does not lose its function.

The thickness of the ink holding layer is sufficient as long as it is sufficient to absorb and capture the recording liquid, and although it varies depending on the amount of recording droplets, it is preferably 1 to 50 pm, more preferably 3 to 20 pm.
It is.

The method for forming the ink retaining layer and surface layer on the substrate is as follows:
A coating solution is prepared by dissolving or dispersing the above-mentioned material 4 in a suitable solvent, and the coating solution is coated using, for example, a roll coating method, a Radvar coating method, a spray coating method, an air knife coating method. It is preferable to apply the material onto the substrate by a known method such as hot-melt coating or to form a single sheet from the material and then apply the sheet to the substrate. A method such as laminating may also be used.

However, when providing the ink retaining layer on the substrate, it is necessary to ensure strong adhesion between the base material and the ink retaining layer and to eliminate spaces.

If there is a space between the base material and the ink retaining layer, the surface of the recorded image will be subject to diffuse reflection, which will lower the substantial 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, felt-tip pens, pen plotters, etc.
, ink mist, inkjet, various types of printing, and other recording devices and devices that use a recording liquid containing a recording agent.

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

The recording liquid used in the recording method of the present invention can be a conventionally known water-based and/or oil-based recording liquid, but in order to quickly penetrate the surface layer and be quickly absorbed and captured by the ink holding layer, , it is necessary that the viscosity of the recording liquid be 500 cps or less. Preferably, the viscosity is 100 cps or less, preferably 50 cps or less.

Furthermore, in consideration of safety against fire, resistance to environmental contamination, etc., water-based recording liquids are preferred.

As the recording agent contained in the recording liquid, conventionally known coloring agents such as dyes and pigments and/or materials with coloring properties can be used. For example, as recording agents used in inkjet recording, direct dyes, acidic Water-soluble dyes such as dyes, basic dyes, reactive dyes, and food dyes are preferred.

In the present invention, methods for making the recording material transparent after recording with a recording liquid include a method using heating, a method using pressure, a method using a combination of heating and pressure, a method using a solvent or a plasticizer, etc. .

For example, to explain specifically how to make the material transparent by heating, the resin particles that form the surface layer are melted by heating,
There is a way to make a uniform coating.

When transparentizing is performed by heating, if the ink retaining layer also melts, the image will be disturbed, and the support will also become softened, which is undesirable as it will induce deformation.

Therefore, it is essential that the melting temperature of the resin forming the surface layer is lower than the melting temperature of the ink retaining layer and the softening temperature of the support.

Usually, when a preferably used polyethylene terephthalate film is used as a base material, it is necessary to heat it at 150° C. or lower.

Further, the process of forming the ink retaining layer and surface layer on the base material usually includes a drying process, but in order to obtain sufficient efficiency in the drying process for practical purposes, the drying temperature should be 60°C or higher, preferably 80°C or higher. ℃ or higher, and therefore the melting temperature of the resin constituting the surface layer needs to be higher than this temperature.

Other methods for making the resin transparent include a method of fusing the resin particles in the surface layer by applying pressure, a method of dissolving and homogenizing the resin particles with a solvent, etc., but all of these methods are suitable for the present invention.

In order to use the translucent print obtained in this manner for observation using transmitted light such as OHP, the recording material must have sufficient translucency after the transparent treatment.

In order to use it for the above purpose, it is necessary that the linear transmittance of the print is 10% or more.

In the present invention, the linear transmittance (T%) refers to the incident light incident perpendicularly to the sample, passing through the sample, and passing through a light-receiving side or lift located on an extension of the incident optical path, at least 8 cm away from the sample, The Y value of the color tristimulus value is determined from the measured spectral transmittance using the following formula.

T=Y/yoX 100 -----(1)T
;Linear transmittance Y;Sample value yO;Blank Y value Therefore, the linear transmittance referred to in the present invention is for straight light, and the diffuse transmittance (also for diffused light by installing an integrating sphere behind the sample) This method differs from methods that evaluate transparency using diffused light, such as opacity (place a white and black backing on the back of the sample and calculate the ratio between them). Since the problem with devices that use optical technology is the behavior of straight-line light, it is important to determine the straight-line transmittance of the print to evaluate the transparency of the print to be used with those devices. , is particularly important.

In the present invention, the obtained translucent printed matter is treated with, for example, OH
When observing using equipment such as P, etc., it is possible to record from the surface layer as in the past and observe the recorded surface using transmitted light, or to observe the mirror image between originals on the surface side. It is also possible to record from the side and observe from the substrate side.

〔Example〕

Hereinafter, the present invention will be specifically explained based on Examples. Note that 1 part in the text is based on weight.

Example 1 Polyethylene terephtate film (
The following composition A was coated on this base material using a bar coater method so that the dry film thickness was 714 mm, and then dried in a drying oven at 120°C for 5 minutes. It dried inside.

Composition A Further, the following composition B was coated on the hill by a bar coater method so that the dry film thickness was 12Jj, m, and the mixture was heated at 80°C for 10 minutes.
Dry in a drying oven for minutes.

Composition B The recording material thus obtained was white and opaque.

Using the four types of ink shown in Table 1 below, we use an on-demand inkjet recording head' that generates bubbles with a heat-generating resistor and ejects the recording liquid using the pressure generated by this recording material. Inkjet recording was carried out using a recording device having the following. Thereafter, the surface layer was heat-treated for 140 mm for 0.1 minute to make it transparent.

The translucent print thus obtained was tested and evaluated in accordance with the following method to determine whether it was suitable for the purpose of the present invention.

1) Ink absorbency was determined by measuring the time it took for the printed matter to dry and fix sufficiently without adhering to the finger when the printed area was touched with the finger after inkjet recording by leaving the print at room temperature.

2) The image transmission density (0-D) after the eclosion process was measured for the black ink recorded area using a Macbeth transmission densitometer TD-504.

3) What is the linear transmittance of the non-recorded area after the transparentization process?

Using a UV-200 spectrophotometer (manufactured by Shimadzu Corporation), the distance from the sample to the window on the light-receiving side was maintained at about 9 cm, and the spectral transmittance was measured and determined from equation (1).

4) Adhesion between the base material and the ink-retaining layer (ink-absorbing layer) in the image area after the transparentization treatment was checked for the black ink-recorded area, and the recorded area was rubbed 10 times using a plastic eraser to test the ink-retaining layer (ink-absorbing layer). ○1. Those that do not cause peeling between the ink absorbing layer) and the base material. Those that caused peeling were rated x.

5) The resolution of the recorded image was evaluated visually according to the following criteria by projecting the print onto a screen using an OHP.

O: pitch width 0.2 mm, thickness 0.1 mm line can be clearly distinguished Δ: pitch width 0.2 mm, size 0.1 mm line cannot be clearly distinguished ×; pitch width 0.5 m 'm, thickness 0.3 mm
L7) Lines cannot be clearly distinguished Further, based on the above results, a comprehensive evaluation was performed and the results of 0 or more are shown in Table 2.

In the overall evaluation, a score of X was given if even one of the above five evaluation items was unsatisfactory.

Table-1 Yellow ink (composition) C, 1, Direct Yellow 86 2 parts N-methyl-2
-pyrrolidone 10 parts diethyl glycol
20 parts polyethylene glycol #200 ts
i water
55 parts Magenta ink (composition) C, 1, acid red 35 2 parts N-methyl-2
-pyrrolidone 10 parts diethyl glycol
20 parts polyethylene glycol #200 15 parts water 55 parts cyan ink (composition C, 1, Direct Blue 86 2 parts N-methyl-2
-pyrrolidone 10 parts diethyl glycol
20 parts polyethylene glycol #200 15 parts water
55 parts Black ink (composition) C, 1, food black 2 2 parts N-methyl-2
-pyrrolidone 10 parts diethyl glycol
20 parts polyethylene glycol #200 15 parts water
55 parts Example 2 The polyethylene terephthalate film used in Example 1 was used as a translucent base material, and the following composition C was applied on this base material.
was coated using a bar coater method to a dry film thickness of 5 ILm, and dried in a drying oven at 110°C for 10 minutes.

Composition C Further, the following composition was coated thereon by a bar coater method to a dry film thickness of 20 gm, and dried in a drying oven at 80° C. for 10 minutes.

Composition D - 100 parts by weight of styrene resin latex (L-8801; manufactured by Asahi Kasei Corporation) - 50 parts by weight of solvent-soluble acrylic resin powder (Dianal LX; manufactured by Mitsubishi Rayon) - Surfactant (-% Rex 0T) -P made by Kao ■ [・Water
100 parts by weight The recording material thus obtained was white and opaque. It was i1. Inkjet recording similar to that in Example 1 was performed on this recording material.

After recording, add 1 to 2 pieces of the recording material to a processing liquid consisting of the following composition.
When subjected to a partial immersion treatment and then dried at room temperature, the resin powder formed a transparent film and a print with excellent translucency was obtained.

Processing solvent/composition and method of Example 1 ← Accordingly, the recording material was evaluated and the results of 0 or more are shown in Table 2.

Example 3 Using the polyethylene terephthalate film used in Example 1 as a translucent base material, the following composition E was applied on this large material.
was applied using a bar coater method to a dry film thickness of 10 gm at 100°C.

Dry in a drying oven for 12 minutes.

Composition E This was further coated with the following Composition F using a bar coater method to a dry film thickness of 104 m, and dried in a drying oven at 70°C for 10 minutes.

Composition F The recording material thus obtained was white and opaque.

Inkjet recording similar to that in Example 1 was performed on this recording material.

After recording, the fixing roller (transport speed 9.5 mm/s
ec, roller linear pressure of 40 kg) to obtain a translucent printed matter.

The obtained prints were evaluated according to the method of Example 1. The results are shown in Table-2.

Example 4 Using the polyethylene terephthalate film used in Example 1 as a translucent base material, the following composition G was coated on this large material by a bar coater method so that the dry film thickness was 8 gm. ℃ for 5 minutes in a drying oven.

Further, on top of Composition G, the following Composition H was coated using a bar coater method so that the dry film thickness was 20 gm, and the mixture was heated at 80°C for 10 minutes.
Dry in a drying oven for minutes.

Composition H The recording material thus obtained was white and opaque.

Ink jet recording similar to that in Example 1 was performed on this recording material.

After recording, processing was carried out by using a combination of heating and pressure using a fixing roller (conveyance speed 9.5 mm/Sec, roller linear pressure 40 kg, roller temperature 150° C.) to obtain a translucent printed matter.

This print was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 1 Completely the same as Example 1, except that Composition A was not applied in Example 1, and only Composition B minus the surfactant was applied onto the lumber. A translucent print was obtained in the same manner. The evaluation results are shown in Table 2.

Comparative Example 2 Completely the same as Example 2, except that in Example 2, Composition C was not applied, and only the composition obtained by removing the surfactant from the composition was applied onto the lumber. A translucent print was obtained. The evaluation results are shown in Table 2.

Comparative Example 3 Completely the same as Example 3, except that 1 Composition E was not applied in Example 3, and only the composition obtained by removing the surfactant from Composition F was applied on the lumber. A translucent print was obtained in the same manner. The evaluation results are shown in Table 2.

Comparative Example °4 Example 4 and Example 4 except that Composition G was not applied and only Composition H excluding the surfactant was applied onto the lumber. A translucent print was obtained in exactly the same manner. The evaluation results are shown in Table 2.

Table-2 Example 1 1 second 1.02 70% ○ ○
02 1 second 0.87 40% OOO 35 seconds 0.95 72% ○ ○ 04
3 seconds 1.00 75% ○ ○ O Comparative example 1
30 seconds 0.85 70% ×××2 1 second 0.
80 40% x Δ x 3 5 seconds 0.90
72% × Δ × 4 3 seconds 0.88 75%
X Δ
An excellent translucent printed matter without peeling between the base material and the ink retaining layer can be obtained in minutes.

Further, in the present invention, since the image is substantially retained and only the surface layer is made transparent, a high-resolution image can be obtained without blurring or disturbance of the image.

Furthermore, in the present invention, i! Since the surface layer becomes non-porous with the brightening treatment, durability such as water resistance and weather resistance, and storage stability of recorded images are significantly improved.

Claims (6)

[Claims] (1) A step of recording with a recording liquid from the surface side of the recording material on a recording material having a liquid-permeable surface layer and an ink holding layer, and a step of making the surface layer transparent. A method for producing a translucent printed matter, characterized by comprising: (2) The method for producing a translucent printed matter according to claim 1, wherein the recording material comprises an ink retaining layer and a surface layer laminated on a translucent base material. (3) The method for producing a translucent print according to claim 1, wherein the transparent print is made transparent by heat treatment. (4) Claim 1: Transparency is achieved by pressure treatment.
Method for creating translucent prints as described in Section 1. (5) A method for producing a translucent printed matter according to claim 1, in which transparency is achieved by using a combination of heat treatment and pressure treatment. (6) The method for producing a translucent print according to claim 1, wherein the transparent print is made transparent using a solvent or a plasticizer.