JPH11321081A - Picture recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a picture recording sheet, convenient in handling, by a method wherein visual recognition is improved and the size of total thickness is reduced. SOLUTION: A picture recording sheet is characterized in an ink receptor layer 3, formed on the rear surface side of a substrate 2 and into which light diffusion agent is mixed, and a protective layer, formed on the front surface side of the substrate 2 and consisting of ultraviolet ray cutting agent as well as hard coating agent. The brightness of a recorded picture is increased by back light whereby the visual recognizability of the recorded picture can be increased and, further, the recorded picture of the picture recording sheet is protected surely whereby the resistance to weather and moisture of the picture recording sheet can be increased remarkably. On the other hand, the light diffusion agent is mixed into the ink receptor layer, formed on the rear surface side of the substrate, whereby the absorption of ink and diffusion of light can be effected through one layer while the protective layer is formed integrally on the front surface side of the substrate whereby bonding of a protective film to the front surface side of the substrate is not required and the size of the thickness of the sheet can be reduced thereby making the handling of the sheet very convenient.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording sheet, and more particularly to an image recording sheet for recording a predetermined image by an image recording apparatus such as an ink jet type and visually recognizing the image by a backlight.

[0002]

2. Description of the Related Art In general, an image recording sheet for recording a predetermined image by an image recording apparatus such as an ink jet type and visually recognizing the image by a backlight is often used.

However, in such an image recording sheet, for example, when applied to a signboard for an advertisement or the like, the visibility of the recorded image is low, so that the visibility of the recorded image is conventionally enhanced. Image recording sheets have been developed.

In such a conventional image recording sheet, an ink image receiving layer is formed on the front side of a base made of a transparent synthetic resin or the like, and a light diffusing agent is applied on the back side of the base. A diffusion layer is formed.

In such a conventional image recording sheet, a desired image is recorded by discharging ink onto the surface of an ink receiving layer of the image recording sheet by an image recording apparatus such as an ink jet type. It is supposed to.

[0006] For example, when the image recording sheet is used for an advertisement signboard, the image recording sheet on which the image is recorded is attached by sticking it to the surface of a signboard body having a light source disposed therein. By turning on the light source of the signboard body with the image recording sheet attached in this way, light from this light source is diffused by the light diffusion layer, and the diffused light passes through the base material and the recorded image. It will be irradiated to the outside, the brightness of the recorded image of the image recording sheet is increased, it is possible to glitter this recorded image brilliantly,
The visibility can be improved.

Further, in general, when an image is recorded on the image recording sheet, the image is usually recorded by using a dye ink. Such a dye ink has poor weather resistance and water resistance, and has an ultraviolet ray. Alternatively, since the recorded image is deteriorated by rain or the like, the surface of the recorded image is covered with a protective film.

[0008]

However, in the conventional image recording sheet, although the visibility can be improved by a backlight, an ink image receiving layer and a light diffusion layer are formed on the front and back surfaces of the base material, respectively. Has a three-layer structure, and furthermore, the surface of the recorded image is covered with a protective film. Since this protective film has a relatively large thickness, when the protective film is attached to the image recording sheet, The overall thickness becomes large, and when the image recording sheet to which the protective film is adhered is wound and stored, transported, etc., there is a problem that handling is extremely inconvenient.

The present invention has been made in view of the above points, and has as its object to provide an image recording sheet which is easy to handle while improving visibility and reducing the overall thickness. is there.

[0010]

In order to achieve the above object, the image recording sheet according to the first aspect of the present invention records a predetermined image by an image recording apparatus such as an ink jet type, and this image is recorded by a backlight. In an image recording sheet for visually recognizing, an ink image receiving layer in which a light diffusing agent is mixed is formed on the back side of the base material, and a protective layer made of an ultraviolet cutting agent and a hard coating agent is formed on the front side of the base material. It is characterized by having done.

According to the first aspect of the present invention, an ink image receiving layer mixed with a light diffusing agent is formed on the back side of the base material, and a UV cut agent and a hard coat agent are formed on the front side of the base material. Since a protective layer is formed, the brightness of the recorded image can be increased by the backlight to enhance the visibility of the recorded image, and the recorded image on the image recording sheet can be protected without fail, and The weather resistance and water resistance of the recording sheet can be significantly improved. Also,
By mixing a light diffusing agent into the ink image receiving layer formed on the back side of the substrate, ink absorption and light diffusion are performed in one layer, and a protective layer is integrally formed on the front side of the substrate. As a result, there is no need to attach a protective film to the surface side of the base material, the thickness can be reduced, and handling becomes extremely convenient.

The invention described in claim 2 is the first invention.
, Wherein at least a surface of the protective layer is subjected to an anti-glare treatment.

According to the second aspect of the present invention, since at least the surface of the protective layer is subjected to an anti-glare treatment, when a recorded image is viewed from the front side of the image recording sheet, it is exposed to external light. The reflection can be prevented, and the visibility of the recorded image can be further improved.

[0014]

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 shows an embodiment of an image recording sheet according to the present invention. This image recording sheet 1 is a sheet-like sheet made of a transparent synthetic resin material such as PET (polyethylene terephthalate). It has a substrate 2, and an ink image receiving layer 3 is formed on the back side of the substrate 2. The ink receiving layer 3 is formed of, for example, a ceramic material such as silica or alumina; a swelling material such as PVA (polyvinyl alcohol); a porous material such as boehmite; Have been. Further, in the present embodiment, the ink image receiving layer 3 has, for example, a light diffusion function made of one or more of glass beads, a filler having a water absorbing ability, a layered mineral, silica, tanker, a spherical polymer, and the like. Is mixed. The particle size of this light diffusing agent is such that the maximum secondary particle diameter is
Of the film thickness of 以下 or less. If the particle size is larger than that, a pinhole is generated in the image, and the image becomes rough. Further, the amount of the light diffusing agent to be added depends on the water-absorbing polymer 10
0 to 10 parts to 200 parts. When the addition amount of the light diffusing agent is small, the light diffusion effect is small, and when the addition amount is large, the coating film strength is weakened. This addition amount is set to an optimum value according to the particle size, shape, refractive index and the like of the material of the light diffusing agent.

When the filler is used, the ink absorbency can be further improved. The ink image receiving layer 3 is formed by applying an aqueous solution obtained by synthesizing a material for forming the ink image receiving layer 3 to the surface of the substrate 2. It may be mixed during the synthesis of the material, or may be mixed after the synthesis.

On the front side of the substrate 2, a protective layer 4
This protective layer 4 is made of, for example, ZnO,
An ultraviolet ray cut agent composed of an inorganic substance such as TiO ₂ or CeO ₂ or an organic substance such as benzotriazole and a hard coat agent having a weather resistance and water resistance composed of a urethane-based, polyester-based or epoxy-based substance. Is formed.

Further, in the present embodiment, fine irregularities are formed on the surface of the protective layer 4 or irregularities are formed on the surface of the protective layer 4 by mixing a filler into the protective layer 4. , Anti-glare treatment.

In the present embodiment, a protective sheet 5 is adhered to the ink receiving layer 3 after the image has been recorded. An adhesive layer 6 that exhibits an adhesive function in this state is formed.

Next, the operation of the present embodiment will be described.

In the present embodiment, a desired image 4 is recorded on the surface of the ink receiving layer 3 of the image recording sheet 1 by discharging ink using, for example, an ink jet type image recording apparatus. It has become.

In this case, since the ink image receiving layer 3 is formed of a material to which ink is easily adsorbed, the ink is appropriately adsorbed and a clear image 4 can be obtained.

Thereafter, in the present embodiment, the protective sheet 5 is adhered to the recording image surface of the image recording sheet 1 on which the image is recorded via an adhesive layer 6 so that the back surface of the image recording sheet 1 is adhered. Cover.

By irradiating the recording image with light from the back side of the image recording sheet 1, this light is diffused and reflected by the light diffusing agent of the ink image receiving layer 3, and the reflected light is used for image recording. Since the light is irradiated to the front side of the sheet 1, the brightness of the recorded image on the image recording sheet 1 is increased, and the recorded image can be brilliantly shined, and the visibility can be improved.

Further, when the image recording sheet 1 is irradiated with external light such as sunlight or rainwater,
The recording image of the image recording sheet 1 can be surely protected by the ultraviolet cut agent and the hard coating agent of the protective layer 4, and the weather resistance and water resistance of the image recording sheet 1 can be remarkably increased. Moreover, in the present embodiment, since the anti-glare treatment is applied to the protective layer 4, when a recorded image is viewed from the front side of the image recording sheet 1, reflection by external light can be prevented, and It is possible to further enhance the visibility of the image.

Therefore, in the present embodiment, the ink receiving layer 3 mixed with the light diffusing agent is formed on the back side of the base material 2 and the ultraviolet cut agent and the hard coat agent are formed on the front side of the base material 2. Since the protective layer 4 is formed, the brightness of the recorded image can be increased by the backlight to enhance the visibility of the recorded image, and the recorded image on the image recording sheet 1 can be protected without fail. The weather resistance and water resistance of the image recording sheet 1 can be significantly improved.

Further, by mixing a light diffusing agent into the ink image receiving layer 3 formed on the back side of the substrate 2, ink absorption and light diffusion can be performed in one layer, and the surface side of the substrate 2 can be absorbed. Since the protective layer 4 is formed integrally with the substrate 2, it is not necessary to attach a protective film to the surface side of the substrate 2, the thickness can be reduced, and the handling becomes extremely convenient.

FIG. 2 shows another embodiment of the present invention.

In this embodiment, a coating layer 7 corresponding to the protective sheet 5 adhered to the back surface of the ink image receiving layer 3 in the embodiment of FIG. 1 is formed by transfer.

That is, as shown in FIG. 2, the coating layer 7 is thinly formed on the surface of the ink image receiving layer 3 in advance.
It is formed by transferring a coating layer 7b formed releasably on a release sheet 8 to a pretreatment coating layer 7a made of the same material as that of the above. In the present embodiment, the coating layer 7
Is formed of a durable coating material such as latex or a thermoplastic adhesive.

In the order of steps, the pretreatment coating layer 7a
As shown in FIG. 2, a liquid mixture of a durable coating material such as latex and a solvent is thinly applied to the back surface of the ink image receiving layer 3 formed on the back surface of the base material 2,
It is formed by drying. The coating material for forming the coating layer 7 may be any material having properties such as water resistance and weather resistance, and includes a UV cut material having UV resistance. It is good to select appropriately according to it. Further, in order to improve the visibility of the recorded image, it is preferable to use a transparent material such as transparent latex for the coating material. Examples of the transparent coating material other than the transparent latex include Aron Melt (trademark) manufactured by Toa Gosei Chemical Industry Co., Ltd., Nissin Hot Melt manufactured by Nissin Chemical Industry Co., Ltd., and Vini Blanc (products manufactured by Nissin Chemical Co., Ltd.) Hot melt materials such as This hot melt material is non-greasy at room temperature, becomes transparent when heated and pressed, exhibits adhesiveness, and is suitable for a transferable coating material. In addition, using a latex encapsulated in a heat-resistant microcapsule as a coating material, the microcapsule is crushed when hot-pressed to the coating layer 7b, and the coating material is protruded to form a pretreatment coating layer 7a. You may make it unify. Also,
If necessary, a translucent, chromatic coating material may be used.

The thickness of the pretreatment coating layer 7a is sufficient to increase the adhesion of the entire coating layer 7 formed integrally with the coating layer 7b to be transferred in the next step to the ink image receiving layer 3. (For example, the thickness of one to a plurality of particles of the coating material: 0.1 to 5 μm), and it is preferable that the thickness does not hinder the penetration of the ink permeated into the ink receiving layer 3 through the pretreatment coating layer 7a. . In the pretreatment coating layer 7a thus formed, a space is formed between the coating materials so that the ink can pass to the ink image receiving layer 3 side.

In the image recording according to this embodiment, ink is ejected (spouted) from the ink jet recording apparatus toward the pretreatment coating layer 7a of the image recording sheet 1 based on the image data.
This is done by letting The ink that has landed on the pre-treatment coating layer 7a passes between the coating materials adjacent to each other and passes through the lower ink image receiving layer 3 in the same manner as in the above-described embodiment.
Proceed to.

Finally, as shown in FIG. 2, a coating layer 7b formed releasably on a release sheet 8 via a release layer 9 is laminated on the surface of the pretreatment coating layer 7a. That is, the coating layer 7b is superimposed on the surface of the pretreatment coating layer 7a, and the whole is passed between the heat-pressing rolls (not shown) in order from left to right in FIG. As a result, the coating materials made of the same material as the pretreatment coating layer 7a and the coating layer 7b are firmly fused to each other to form the integral coating layer 7, and
In particular, the coating material of the pretreatment coating layer 7a penetrates between the materials for forming the ink image receiving layer 3, and is transferred and formed to the ink image receiving layer 3 with a large adhesive force. Then, the release sheet 8 is released from the coating layer 7 to form the image recording sheet 1.

The thickness of the integral covering layer 7 is as follows:
The thickness should be at least sufficient to protect the image formed on the ink image receiving layer 3.

If the coating layer 7b, which is releasably laminated on the release sheet 8 made of a material such as a PET film via the release layer 9, is directly releasably adhered to the release sheet 8, the release layer 9 can be omitted. When the surface of the release sheet 8 is flat, the surface of the coating layer 7b transferred to the ink image receiving layer 3 is formed flat, and gloss is imparted. Further, when fine irregularities are imparted to the surface of the release sheet 8, the surface of the coating layer 7b transferred to the ink image receiving layer 3 is imparted with fine irregularities, and is subjected to an antiglare treatment. Characters can be easily written or printed on the portion subjected to the anti-glare treatment. Therefore, by providing flat portions and uneven portions at desired positions on the surface of the release sheet 8,
Flat portions and uneven portions can be designed and arranged at desired positions on the surface of the coating layer 7 of the image recording sheet 1. Further, a predetermined uneven pattern is formed by embossing the surface of a heat-pressing roll (not shown) that presses and heats the release sheet 8 at the time of transfer, and the uneven pattern is formed via the release sheet 8 and the release layer 9. Then, the surface of the coating layer 7 transferred at the time of transfer is pressed, and the flat portion and the uneven portion may be designed and arranged at desired positions on the surface of the coating layer 7 of the image recording sheet 1. If the surface of the heat roll is coated with a silicone resin or a fluorine-based resin to impart releasability, the width of the substrate 2 and the release sheet 8 that are being pressed and heated by the heat-pressing roll can be adjusted. Even if the pre-treatment coating layer 7a formed on the surface of the ink-receiving layer 3 on the base material 2 is in direct contact with the heat-pressing roll, the pre-treatment coating layer 7a In addition, it is possible to prevent the ink image receiving layer 3 from being erroneously transferred to the heating and pressing roll side. The transfer of the coating layer 7b to the pretreatment coating layer 7a is performed by directly contacting the base material 2 and the release sheet 8 as shown in FIG. May be transferred to an intermediate transfer roll (not shown), and then transferred from the intermediate transfer roll to the surface of the pretreatment coating layer 7a on the substrate 2 side. If a pattern to which the coating layer 7b is to be transferred is formed on the surface of the transfer roll in the same manner as when offset printing is performed, the coating layer 7 corresponding to the predetermined pattern is formed on the surface of the ink image receiving layer 3. be able to.

In FIG. 2, the coating layer 7b and the release layer 9
Another functional layer having another function may be provided between the first and second layers. Since the other functional layer is not directly transferred to the pretreatment coating layer 7a formed on the surface of the ink image receiving layer 3, a material different from the pretreatment coating layer 7a and the coating layer 7b may be used. The other functional layer may have any function, for example, a UV cut layer for preventing the effect of ultraviolet rays, a hard coat layer for imparting hardness to the image recording sheet, and both of the above functions. A UV-cut hard coat layer having the following properties, a weather-resistant layer for imparting weather resistance, a solvent-resistant layer for imparting solvent resistance, and the like. As the material of the other functional layer that exerts these functions, it is preferable to use one or a combination of a plurality of types in the content of a known function of providing a resin agent. Examples of these resins include melamine resins, alkyd resins, acrylic resins, polyester resins, fluororesins, silicone resins, and acrylic silicone resins. Specifically, when a UV cut layer is provided as another functional layer, as a UV cut layer material, for example, a trade name: RUVA manufactured by Otsuka Chemical Co., Ltd.
-93, PUVA-30M or the like may be used. The thickness of the UV cut layer may be any thickness as long as it can absorb ultraviolet rays and prevent fading of the ink.
It is good to be about μm. Further, a coating layer may be further formed as another functional layer. In this case, one of the ink receiving layers 3
As a material for forming the pre-treatment coating layer 7a and the coating layer 7b to be formed on the surface of
T) and a material having a low glass transition point (Tg),
Transfer at low temperature is possible and pretreatment coating layer 7a
And a material having a high minimum film formation temperature (MFT) and a high glass transition point (Tg) as a material for forming a coating layer for forming the other functional layer. Can be improved. On the other hand, as a material having a low minimum film-forming temperature (MFT) and a low glass transition point (Tg), the above-mentioned product number 240 of Vinyblan (trade name) manufactured by Nissin Chemical Co., Ltd. can be mentioned. The length is preferably about 10 μm. On the other hand, as a material having a high minimum film forming temperature (MFT) and a high glass transition point (Tg), the above-mentioned product number 602 of Vinyblan (trade name) manufactured by Nissin Chemical Co., Ltd. can be mentioned. The thickness is preferably about 2 μm.

Further, by collecting the release sheet 8 after transferring the coating layer 7 and forming the coating layer 7 again, the material can be reused and environmental pollution can be prevented. .

The present invention is not limited to the above embodiments, but can be variously modified as needed.

[0040]

As described above, in the image recording sheet according to the first aspect of the present invention, the ink receiving layer containing the light diffusing agent is formed on the back surface of the base material, Since a protective layer composed of an ultraviolet ray cut agent and a hard coat agent is formed on the recording medium, the backlight can enhance the luminance of the recorded image and enhance the visibility of the recorded image, and moreover, the image recording sheet can be reliably formed. And the weather resistance and water resistance of the image recording sheet can be significantly increased. Also, by mixing a light diffusing agent into the ink image receiving layer formed on the back surface side of the base material, absorption of ink and diffusion of light are performed in one layer, and a protective layer is integrally formed on the front surface side of the base material. Since it is formed, it is not necessary to attach a protective film to the surface side of the substrate, the thickness can be reduced, and handling becomes extremely convenient.

According to the second aspect of the present invention, since at least the surface of the protective layer is subjected to an anti-glare treatment, when a recorded image is viewed from the front side of the image recording sheet, reflection by external light is prevented. This can provide an effect that the visibility of the recorded image can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of an image recording sheet according to the present invention.

FIG. 2 is a schematic cross-sectional view showing another embodiment of the image recording sheet according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image recording sheet 2 Base material 3 Ink image receiving layer 4 Protective layer 5 Protective sheet 6 Adhesive layer

Claims (2)

[Claims] 1. An image recording sheet for recording a predetermined image by an image recording apparatus such as an ink jet type and visually recognizing the image by a backlight, wherein an ink in which a light diffusing agent is mixed on the back side of the base material. An image recording sheet comprising an image receiving layer, and a protective layer comprising an ultraviolet ray cut agent and a hard coat agent formed on the surface side of the substrate. 2. The image recording sheet according to claim 1, wherein at least a surface of the protective layer has been subjected to an anti-glare treatment.