JPH0739206B2 - How to make translucent prints - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to the production of a translucent print using a recording liquid,
In particular, the present invention relates to a method for producing a translucent printed matter having excellent recorded image sharpness and ink absorbency.

[Conventional technology]

A method of recording using a recording liquid has been popular since writing has been fountain pen writing, for example, but recently, a so-called ink jet recording system has also appeared, and the recording liquid is also used here.

The ink jet recording method generates droplets of a recording liquid (droplets) according to various operating principles and causes the droplets to fly and adhere to a recording material to perform recording. It has attracted attention as a recording method characterized by being capable of multicolor printing. As a recording liquid for ink jet recording, an aqueous liquid is mainly used in terms of safety and recording suitability.

Conventionally, ordinary paper has been generally used as the recording material used in the ink jet recording method. However, as the performance of ink jet recording devices has improved, such as speeding up recording and increasing the number of colors, recording materials such as ink-jet recording paper that have a porous ink absorption layer on the substrate and have increased ink absorption have become Developed and used. In order to obtain a high resolution and high quality recording image in the ink jet recording system, these recording materials are 1) capable of absorbing ink rapidly and 2) when ink dots are overlapped later. The adhered ink does not flow to the previous dot 3) The diameter of the ink dot does not become larger than necessary, 4) The shape of the ink dot is close to a perfect circle, and its periphery is smooth, 5) The density of the ink dot It is necessary to satisfy the required performance as a recording material, such as a high color density, no blur around the dots, and 6) excellent color development of the ink.

Up to now, in ink jet recording, a recording material has been used to obtain a recorded image for surface image observation, but with the improvement of ink jet recording technology and the spread of devices, the characteristics of ink jet recording have been utilized. It has become possible to use it for other purposes. Examples of applications other than surface image observation include, for example, observing recorded images on a screen with an optical device such as a slide or OHP (overhead projector), contact printer, printing plate master (photomask), Color separation plates for making positive plates for color printing, CMF (color mosaic filter) for liquid crystal color displays, etc.

Transparent negatives and positives used in optical equipment or devices that use optical technology can be created by taking a picture of the recorded material or the material to be recorded, or by recording directly on a transparent recording material such as a plastic film. Although the ink jet recording is performed using a transparent recording material for inkjet, the recording is speeded up and the full resolution of high quality with high resolution that can be used in the above optical devices is achieved. A recorded image can be obtained. Therefore, in order to use it for such an application, in addition to the performance required for the recording material for the general ink jet recording described above, it is necessary to have transparency suitable for the intended application.

As the transparent recording material, a method is known in which a porous ink-receiving layer is provided on a transparent substrate, an image is recorded by an ink jet recording method, and then a transparent treatment is performed to obtain a printed matter for transmitted light observation. ing.

The recording material used in this method is excellent in ink absorbability, but it is inferior in color developability because the dye in the recording liquid partially aggregates after being made transparent. In addition, since the material itself constituting the porous ink-receiving layer itself does not have sufficient ink-retaining property, the ink remains liquid at the interface between the transparent substrate and the ink-receiving layer after making it transparent, which may cause image bleeding or blurring. It has drawbacks such as easy peeling of the ink receiving layer.

[Problems to be solved by the invention]

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a light-transmitting material which is particularly excellent in sharpness, resolution, and optical density of a recorded image and which is suitable for high-speed recording. It is to provide a method for producing a sex print.

Another object of the present invention is to provide a method for producing a translucent printed matter which is excellent in ink receptivity, water resistance of a recorded image, light resistance, blocking resistance, storability and the like.

Still another object of the present invention is to provide a method for producing a translucent printed matter in which the base material and the ink holding layer are not separated from each other in the ink recording portion.

[Means for solving problems]

 The above object is achieved by the present invention described below.

That is, the present invention is directed to a recording material in which a light-transmitting ink holding layer and an opaque surface layer which is non-adsorptive to a recording agent and has liquid permeability are sequentially laminated on a transparent substrate. A method for producing a translucent print, comprising: a step of recording with a recording liquid from a surface layer side of the recording material; and a step of making the surface layer transparent.

[Work]

The main feature of the present invention is that after recording with a recording liquid on a recording material having a surface layer and an ink holding layer, only the surface layer is made transparent.

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

The absorption at this time is mainly the wetting and permeation of the recording liquid into the surface layer, and the absorption rate is remarkably excellent as compared with the conventional case where the absorption in the ink absorbing layer using a hydrophilic polymer is diffusion and permeation. ing.

On the other hand, as a preferred embodiment having liquid permeability, a porous structure having cracks inside the surface layer and the like can be mentioned. However, since such a structure is light diffusing, in order to obtain a translucent printed matter, recording After performing the above, it is necessary to carry out a transparency treatment.

In this clearing process, the substance that constitutes the liquid-permeable surface layer changes into a uniform structure with small light diffusivity, but it becomes transparent when the recording liquid or recording agent remains in this layer. In the case of (1), it is difficult to obtain a clear image because the recording agent agglomerates non-uniformly due to the problem of the compatibility of the substance constituting the liquid-permeable surface layer and the recording agent.

Therefore, in the present invention, by providing the ink holding layer in contact with the surface layer having liquid permeability, even after the surface layer is made transparent,
We have found that a clear image can be obtained.

The ink holding layer absorbs and holds the recording liquid temporarily absorbed in the surface layer, and the ink absorption speed may be smaller than that of the surface layer, but the absorption power must be larger than that of the surface layer.

The absorption in the ink holding layer is mainly diffusion and penetration, and the recording material is evenly dispersed to form a clear image.

The relationship between diffusion penetration and wet penetration is absorption rate diffusion << wetting absorption capacity diffusion >> wetting, and in the present invention, the advantages of diffusion penetration and wet penetration are utilized.

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

The recording material of the present invention absorbs a base material as a support and a recording liquid or a recording agent formed on the support,
It is composed of an ink holding layer for capturing and a surface layer formed on the ink holding layer, which directly receives the recording liquid, has liquid permeability, and does not substantially leave the recording agent.

However, when the surface layer or the ink holding layer also has a function as a base material, the base material is not always necessary.

As the base material used in the present invention, conventionally known materials can be used, and specifically, polyester resin, diacetate resin, triacetate resin, polystyrene resin, polyethylene resin, polycarbonate resin, polymethacrylate resin, cellophane, celluloid, poly Examples thereof include plastic films such as vinyl chloride resin and polyimide resin, plates or glass plates.

Since the present invention is intended to obtain a translucent printed matter, the substrate needs to be transparent.

Further, by selecting a substrate having water resistance, abrasion resistance and blocking resistance as the substrate, 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 the property of allowing the recording liquid to quickly pass therethrough and substantially not allowing the recording material in the recording liquid to remain in the surface layer.

A preferred embodiment of the liquid-permeable surface layer has a porous structure having cracks and communicating holes inside the surface layer and can be made transparent by heating, pressurizing, a solvent or the like.

The surface layer for satisfying 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-adsorptive to the recording agent, and can be melted and homogenized by using a resin or a solvent that can be fused and homogenized by heating and / or pressure. At least one of organic particles such as resin, for example, polyethylene, polymethacrylate, elastomer, ethylene-vinyl acetate polymer, styrene-acryl copolymer, polyester, polyacryl, polyvinyl ether, or other resin powder and emulsion is desired. Used by.

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

Further, the binder used has a function of binding the resin particles to each other and / or the ink holding layer,
Like the resin particles, it needs to be non-adsorptive to the recording agent.

As a preferable material for the binder, any conventionally known material can be used as long as it has the above-mentioned function.
Polyvinyl alcohol, acrylic resin, styrene-acrylic copolymer, ethylene-vinyl acetate copolymer, starch, polyvinyl butyral, gelatin, casein, ionomer, gum arabic, carboxymethyl cellulose, polyvinylpyrrolidone, polyacrylamide, phenol, melanin, epoxy, One or more resins such as styrene-butadiene rubber can be used if desired.

Further, in order to improve the function as the surface layer, various additives such as a surfactant and a penetrating agent may be added to the surface layer, if necessary.

The mixing ratio (weight ratio) of the resin particles and the binder is preferably in the range of resin particles / binder = 1/2 to 50/1, and more preferably in the range of 3/1 to 20/1. Is.

If the mixing ratio is 1/2 or less, the surface cracks and communication holes become small, and the effect of absorbing the recording liquid decreases. Also,
When the mixing ratio is 50/1 or more, the adhesion between the resin particles or the ink holding layer and the resin particles becomes insufficient, and the surface layer cannot be formed.

The thickness of the surface layer is preferably 1 to 200 μm, and more preferably 3 to 50 μm, although it depends on the recording droplet amount.

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

The ink holding layer needs to have a stronger absorbing power for the recording liquid than the surface layer.

This is because when the absorption capacity of the ink holding layer is weaker than that of the surface layer, when the recording liquid applied to the surface of the surface layer passes through the surface layer and the leading end of the recording liquid reaches the ink holding layer. In addition, the recording liquid stays in the surface layer, and the recording liquid permeates and diffuses laterally in the surface layer at the interface between the surface layer and the ink holding layer. As a result, the resolving power of the recorded image is lowered, and it becomes impossible to form a high quality image.

Further, the ink holding layer needs to be light transmissive.

The ink holding layer satisfying the above requirements is preferably composed of a light-transmitting resin that adsorbs a recording agent and / or a light-transmitting resin that is soluble and swellable in a recording liquid.

For example, when an aqueous recording liquid containing an acidic dye or a direct dye is used as a recording agent, the ink holding layer contains a cationic resin having an adsorptivity for the dye, for example, a quaternized polyamine and / or It is composed of a hydrophilic polymer having a swelling property for an aqueous recording liquid.

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

The thickness of the ink holding layer may be sufficient to absorb and capture the recording liquid and varies depending on the recording droplet amount, but it is preferably 1 to 50 μm, and more preferably 3 to 20 μm.

As a method of forming the ink holding layer and the surface layer on the substrate,
The materials listed above are dissolved or dispersed in a suitable solvent to prepare a coating solution, and the coating solution is known, for example, by a roll coating method, a rod bar coating method, a spray coating method, an air knife coating method, or the like. The method of coating on the substrate by the method of, and then quickly drying is preferable. For example, a hot melt coating method is used to form the above material or a single sheet is formed from the above material, and the sheet is laminated on the substrate. The method of is also good.

However, when the ink holding layer is provided on the substrate, it is necessary to strengthen the adhesion between the base material and the ink holding layer and eliminate the space.

The presence of a space between the substrate and the ink holding layer is not preferable because the surface of the recorded image is diffusely reflected and the optical density of the image is substantially lowered.

As means for recording an image using the recording material of the present invention, a fountain pen, ballpoint pen, felt pen, pen blotter, ink mist, ink jet, various printing, etc. A device is mentioned.

From the viewpoint of high speed of image recording, an ink jet recording device or a pen blotter is preferable.

As the recording liquid used in the recording method of the present invention, conventionally known water-based and / or oil-based recording liquids can be used, but in order to quickly permeate into the surface layer and be quickly absorbed and captured in the ink holding layer. It is necessary that the viscosity of the recording liquid is 500 cps or less. Preferably, the viscosity is 100 cps or less, suitably
It is less than 50cps.

An aqueous recording liquid is preferable in view of safety against fire and pollution resistance to the environment.

As the recording agent to be contained in the recording liquid, conventionally known coloring agents such as dyes and pigments and / or materials having a coloring property can be used. For example, as the recording agent used for ink jet recording, a water-soluble dye represented by a direct dye, an acid dye, a basic dye, a reactive dye, an edible pigment, etc. is preferable.

In the present invention, examples of the method of making the recording material transparent after recording with a recording liquid include a method by heating, a method by pressurizing, a method of using heating and pressurizing in combination, a method of using a solvent or a plasticizer, and the like. .

For example, specifically explaining the method of making transparent by heating, by melting the resin particles forming the surface layer by heating,
There is a method of forming a uniform film.

In the case of making transparent by heating, if the ink holding layer is also melted, the image is disturbed and the support is also softened, which causes deformation and is not desirable.

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

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

Further, the step of forming the ink holding layer or the surface layer on the substrate usually includes a drying step, but in order to obtain sufficient efficiency in the drying step in practice, the drying temperature is 60 ° C. or higher, preferably
The temperature is 80 ° C or higher, and therefore the melting temperature of the resin constituting the surface layer needs to be higher than this temperature.

In addition to this, as a method of making transparent, a method of fusing the resin particles of the surface layer by pressure, a method of dissolving and homogenizing with a solvent, and the like can be mentioned.

In order to use the translucent print obtained in this manner for observation of transmissive light such as OHP, the translucency of the recording material after the transparency treatment must be sufficient.

In order to use it for the above purpose, the linear transmittance of the print
It must be 10% or more.

The linear transmittance (T%) referred to in the present invention means that the light is incident perpendicularly to the sample, passes through the sample, passes through the light-receiving side slit on the extension line of the incident optical path at least 8 cm or more from the sample, and The spectral transmittance of the linear light received by is measured using, for example, a UV-200 spectrophotometer (manufactured by Shimadzu Corporation), and from the measured spectral transmittance, the Y value of the tristimulus value of the color is calculated. It is a value obtained by the following equation.

T = Y / y ₀ × 100 (1) T; linear transmittance Y; sample value y ₀ ; blank Y value Therefore, the linear transmittance referred to in the present invention is for linear light and diffuse transmission. Diffusion such as rate (an integrating sphere is placed behind the sample to obtain the transmittance including diffused light) and opacity (the white and black backing is applied to the back of the sample and the ratio is calculated) It is different from the method of evaluating transparency by light. Since the behavior of linear light is a problem in devices that use optical technology, it is not possible to determine the linear transmittance of the printed product in order to evaluate the transparency of the printed product to be used in those devices. , Especially important.

In the present invention, the translucent print obtained is used as, for example, an OHP.
When observing with a device such as the above, recording may be performed from the surface side as in the conventional case and the recording surface may be observed with transmitted light. It can also be observed from the material side.

[Examples] Hereinafter, the present invention will be specifically described based on Examples.
In addition, in the text, parts are based on weight.

Example 1 A polyethylene terephthalate film (thickness 100 μm; manufactured by Toray Industries, Inc.) was used as a translucent base material, and the following composition A was coated on this base material by a bar coater method so that the dry film thickness was 7 μm. It was coated and dried in a drying oven at 120 ° C for 5 minutes.

Composition A Further, the following composition B was applied thereon by a bar coater method so that the dry film thickness was 12 μm, and dried in a drying oven at 80 ° C. for 10 minutes.

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

An on-demand type ink jet recording head for generating bubbles (foam) with a heating resistor and discharging the recording liquid with the pressure using four kinds of ink shown in Table 1 below for this recording material is provided. Ink jet recording was performed using a recording device. Then, the surface layer was heat-treated at 140 ° C. for 1 minute to make it transparent.

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

1) The ink absorbency was measured by measuring the time until the ink was not adhered to the finger and was sufficiently dried and fixed even after the printed material was left at room temperature after the ink jet recording and the recording portion was touched with the finger.

2) The image transmission density (OD) after the light-transmitting treatment was measured on the black ink recording portion using a Macbeth transmission densitometer TD-504.

3) The linear transmittance of the non-recording area after the transparency treatment is UV-200.
Using a spectrophotometer (manufactured by Shimadzu Corporation), the distance from the sample to the window on the light receiving side was kept at about 9 cm, the spectral transmittance was measured, and the value was calculated from the equation (1).

4) Adhesion between the base material and the ink holding layer (ink absorbing layer) in the image area after the transparentization treatment was performed for the black ink recording area, and the recording area was rubbed 10 times with a plastic eraser to remove the ink holding layer ( The case where peeling between the ink absorbing layer) and the substrate did not occur was marked with ◯, and the case where peeling occurred was marked with x.

5) The resolution of the recorded image was evaluated according to the following criteria by visually projecting the printed matter on the screen by OHP.

○: A line with a pitch width of 0.2 mm and a thickness of 0.1 mm can be clearly discriminated. △: A line with a pitch width of 0.2 mm and a thickness of 0.1 mm cannot be clearly discriminated. ×: A pitch width of 0.5 mm and a thickness of 0.3 mm. Lines that cannot be clearly distinguished From the above results, a comprehensive evaluation was performed. The above results are shown in Table 2.

In the comprehensive evaluation, even one of the above-mentioned five evaluation items was insufficient, and was evaluated as x.

Table-1 Yellow ink (composition) CI Direct Yellow 86 2 parts N-methyl-2-pyrrolidone 10 parts Diethyl glycol 20 parts Polyethylene glycol # 200 15 parts Water 55 parts Magenta ink (composition) CI 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) CI Direct Blue 86 2 parts N-methyl-2-pyrrolidone 10 parts Diethyl glycol 20 parts Polyethylene glycol # 200 15 parts Water 55 Part Black ink (composition) CI 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 Polyethylene used in Example 1 as a translucent base material. Using a terephthalate film, the following composition C was formed on this substrate.
Was coated by a bar coater method so as to have a dry film thickness of 5 μm, and dried at 110 ° C. for 10 minutes in a drying furnace.

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

Composition D The recording material thus obtained was white and opaque. The same ink jet recording as in Example 1 was performed on this recording material.

After recording, add 1 to 2 of the recording material to the treatment liquid composed of the following composition.
When the resin powder was subjected to a dipping treatment and then dried at room temperature, the resin powder formed a transparent film, and a printed matter having excellent translucency was obtained.

Treatment solvent composition The recording material was evaluated according to the method of Example 1. The above results are shown in Table-2.

Example 3 The polyethylene terephthalate film used in Example 1 was used as a light-transmitting substrate, and the following composition E was formed on this substrate.
Was coated by a bar coater method so as to have a dry film thickness of 10 μm, and dried at 100 ° C. for 12 minutes in a drying furnace.

Composition E Further, the following composition F was coated thereon by a bar coater method so as to have a dry film thickness of 10 μm, and dried in a drying oven at 70 ° C. for 10 minutes.

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

The same ink jet recording as in Example 1 was performed on this recording material.

After recording, pressure was applied by a fixing roller (conveying speed: 9.5 mm / sec, roller linear pressure: 40 Kg) to obtain a translucent printed matter.

According to the method of Example 1, the obtained printed matter was evaluated. The results are shown in Table-2.

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

Composition G Further, the following composition H was coated thereon by a bar coater method so that the dry film thickness was 20 μm, and dried in a drying oven at 80 ° C. for 10 minutes.

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

The same ink jet recording as in Example 1 was performed on this recording material.

After recording, fixing roller (conveying speed 9.5 mm / sec, roller linear pressure 4
(0 Kg, roller temperature 150 ° C.), and heat treatment was applied in combination to obtain a light-transmitting print.

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

Comparative Example 1 The same as Example 1 except that the composition A was not applied and only the composition obtained by removing the surfactant from the composition B was applied on the substrate. In the same manner, a translucent printed matter was obtained. The evaluation results are shown in Table 2.

Comparative Example 2 Exactly the same as Example 2 except that the composition C was not applied and only the composition obtained by removing the surfactant from the composition D was applied on the substrate. Then, a translucent print was obtained. The evaluation results are shown in Table 2.

Comparative Example 3 The same as Example 3 except that the composition E was not applied and only the composition obtained by removing the surfactant from the composition F was applied on the substrate. In the same manner, a translucent printed matter was obtained. The evaluation results are shown in Table 2.

Comparative Example 4 The same as Example 4 except that the composition G was not applied and only the composition H except the surfactant was applied on the substrate. In the same manner, a translucent printed matter was obtained. The evaluation results are shown in Table 2.

[Effect] According to the method of the present invention, it is possible to obtain an excellent light-transmitting printed matter which does not cause separation of the substrate and the ink holding layer in the image portion recorded with the recording liquid.

Further, in the present invention, since only the surface layer that does not substantially retain an image is subjected to the transparency treatment, a high-resolution image can be obtained without blurring or disturbance of the image.

Further, in the present invention, since the surface layer becomes non-porous with the transparency treatment, the durability of the recorded image such as water resistance and weather resistance and the storage stability are remarkably improved.

Front page continuation (72) Inventor Ryuichi Arai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-59-178288 (JP, A) JP-A-58-110287 ( JP, A) JP-A-57-89954 (JP, A)

Claims (5)

[Claims] 1. A recording material in which a light-transmitting ink holding layer and an opaque surface layer which is non-adsorptive to a recording agent and has liquid permeability are sequentially laminated on a transparent substrate. A method for producing a translucent print, comprising: a step of recording with a recording liquid from the surface side of the recording material; and a step of making the surface layer transparent. 2. The method for producing a translucent print according to claim 1, wherein the heat treatment is used to make the material transparent. 3. The method for producing a translucent printed matter according to claim 1, wherein the transparentization is performed by a pressure treatment. 4. The method for producing a translucent print according to claim 1, wherein the heat treatment and the pressure treatment are used together to make the material transparent. 5. The method for producing a translucent print according to claim 1, wherein the solvent or the plasticizer is used for transparency.