JP2002178631A - Ink jet recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet which has so unique exterior and texture as to widen the variation of designs and heighten the effect of the design and is excellent in water resistance and printability. SOLUTION: In the ink jet recording sheet having at least a base material and an ink receiving layer, the base material is made of a plastic film having a specific gravity of 0.5 to 0.85 and being embossed. In addition, the opacity according to JIS P 8138 of the ink receiving layer is set to be 50% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet, and more particularly, to a sheet having a unique appearance and texture capable of widening design variations and enhancing the effect of design, and having improved water resistance and printability. Also relates to an excellent ink jet recording sheet.

[0002]

2. Description of the Related Art Conventionally, in the case of materials and media on which printing, printing, printing, and the like are recorded, importance is often placed not only on the suitability for the recording method but also on the appearance and texture of the material and the medium itself. is there. In such a case, there are various applications where design is required. For example, in applications such as posters, greeting cards, gift calendars, etc., in order to enhance the effect of the design, the materials and media to be recorded are used. Appearance and texture play an important role. Therefore, conventionally, media having various characteristics such as various fine papers, glossy papers, and pattern papers have been developed and used.

[0003] In addition, depending on the application, in terms of water resistance and strength,
In many cases, a medium to be recorded is desirably plastic instead of paper. For example, a plastic film that has been subjected to a surface treatment or various synthetic papers is used.

On the other hand, various printing methods such as offset printing and silk screen printing, and various printing methods such as an ink jet recording method and a thermal transfer recording method have been used as a recording method. Above all, the ink jet recording method has the advantage of not requiring the creation of a plate or an ink ribbon, high speed, low noise, easy multi-coloring, the possibility of enlarging an image, and the flexibility of recording patterns. Nature
Furthermore, it has a feature that development and fixing are not required, and has been rapidly spreading in various applications in recent years as a method for obtaining hard copies of various graphics including characters, color images, and the like.

[0005] The recording sheet used in such an ink jet recording method is usually white plain paper or photo glossy paper, and as described above, the surface of the plastic film is improved to improve water resistance and strength. Treated and various synthetic papers are also used. However, ink jet recording, which uses a plastic film as the base material, has a unique appearance and texture that allows the recording sheet itself to widen design variations and enhance the design effect, and is excellent in printability. At present, there are very few sheets for use.

[0006]

SUMMARY OF THE INVENTION In view of the above problems of the conventional ink jet recording sheet, the present invention uses a plastic film as a base material, and the recording sheet itself has a unique appearance and texture. An object of the present invention is to provide a recording sheet having excellent printing suitability for an ink jet recording method.

[0007]

Means for Solving the Problems An object of the present invention to solve the above problems is to provide an ink jet recording sheet having at least a substrate and an ink receiving layer, wherein the substrate has a specific gravity of O. .5 ~ O.85, consisting of embossed plastic film, and
The opacity of the ink receiving layer according to JIS P 8138 is 50.
% Or less.

The plastic film which is the base material of the recording sheet of the present invention has been embossed and has a unique appearance and texture compared to an unprocessed one. An ink receiving layer is provided on a plastic film. However, since the opacity is low, the appearance and texture of the substrate can be seen through the ink receiving layer.

The plastic film used as the base material of the recording sheet of the present invention is a plastic film which is particularly excellent in embossability among films, and is capable of deep and clear embossing.

Further, the ink receiving layer of the recording sheet of the present invention has low opacity and excellent ink jet recording suitability, so that a high quality image can be obtained.

In the present invention, in addition to the above constitution, there is also a constitution in which the ink receiving layer contains fine particle silica having an average primary particle diameter of 7 nm to 40 nm, and a constitution in which the plastic film is a foamed plastic film.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the ink jet recording sheet of the present invention will be described. The recording sheet of the present invention has a configuration having at least the following base material and an ink receiving layer.In addition to the configuration in which the ink receiving layer is provided directly on the base material, the ink receiving layer is appropriately provided between the base material and the ink receiving layer. An anchor coat layer or an intermediate layer having low opacity may be provided.

The plastic film as the base material of the recording sheet of the present invention can be selected from various types. From the viewpoint of the material, select from general thermoplastic resin films such as polyethylene terephthalate, polypropylene, polystyrene, polycarbonate, etc., those containing inorganic powders such as calcium carbonate, and those containing organic pigments. It is possible to Further, from the viewpoint of the structure, it is possible to select from those in which voids are generated during the manufacturing process, multilayers, and the like. Further, the plastic film of the substrate in the present invention also includes synthetic paper.

In the present invention, it is necessary to select a plastic film having a specific gravity of 0.5 to 0.85 as the base plastic film. If it is less than O.5, the strength of the film is insufficient,
If it exceeds O.85, the reproducibility of the embossed pattern will be insufficient. More preferably, it is 0.5 to 0.75. Examples of such a film include, for example, a trade name (manufactured by Chisso Corporation; Calre (FNR type and FNF type)) produced mainly with cyclopentadiene.

As a method of adjusting the specific gravity of the plastic film, there are a method of selecting a material, a method of providing holes in the film by some method, and the like. As the one provided with the holes, a foamed plastic film is suitably used from the viewpoint of the reproducibility of the embossed pattern and the concealing property. here,
A foamed plastic film refers to a plastic film having cracks or voids formed on the surface or inside of the film, or having fine bubbles or cavities, which contain inorganic powder such as calcium carbonate. Name, forming method, bubbles, etc., such as those formed by stretching a stretched film to generate cavities around the inorganic powder (microvoid film) or foaming a foaming agent in a film containing a foaming agent. The form of the cavity is not limited.

The embossing of the base material in the present invention is generally performed as embossing of paper or film, and transfers the unevenness of the plate to a sheet by applying heat or pressure. Yes, various schemes can be used. For example, various devices such as a lithographic press and a roll embossing machine can be used, and various systems such as on-machine embossing, off-machine embossing, double-sided embossing, and single-sided embossing can be used. In addition, wiping may be performed after embossing to fill the concave portion with wiping ink to further enhance the design.

Next, the ink receiving layer in the present invention can be provided by coating a substrate. For example, the coating can be performed by an apparatus such as an air knife coater, a bar coater, and a roll coater.

The ink receiving layer contains a pigment component, a binder, an additive and the like. The ink receiving layer must have an opacity of 50% or less in accordance with JIS P 8138 in order to prevent the appearance and the material of the base film from being concealed and to exert the appearance effect of embossing.

The pigment component is water-insoluble and includes silica, calcium carbonate, magnesium carbonate, diatomaceous earth, talc, titanium oxide, alumina sol and the like, and these can be used alone or in combination. Synthetic silica is effective from the viewpoint of ink absorption capacity. When the particle diameter of the pigment increases, the irregularity of light increases, and the transparency of the ink receiving layer decreases. For the purpose of the present invention, the pigment preferably has an average primary particle size of 7 nm to 40 nm. In particular, it is more preferable to use silica having an average primary particle diameter of 7 nm to 10 nm in terms of transparency. The content of the pigment component is 60% by weight to 80% by weight of the total solids in the receiving layer.
Is preferred.

Suppressing the opacity of the ink-receiving layer, through which the embossed state of the base plastic film is visible, has several advantages. For example, when an ink receiving layer is provided on the embossed substrate by coating or the like, a phenomenon occurs in which the coating liquid fills the concave portions of the embossed pattern. Therefore, the irregularities on the surface of the ink receiving layer
It does not accurately reflect the embossed pattern of the base material, and the difference in height between the concave portions and the convex portions is smaller than that of the base material. Therefore, when an opaque ink-receiving layer is provided, there is little difference in height between the concave portions and the convex portions on the surface, that is, an embossed product having an unclear pattern. On the other hand, when the opacity of the ink receiving layer is low, the embossed pattern of the base material is seen through the ink receiving layer even if the height difference between the concave portion and the convex portion on the surface is small. Goods. Also, a method of embossing after providing an opaque ink receiving layer on a flat base material can be considered, but it is difficult to achieve both embossing suitability and printing suitability of the ink receiving layer. Problems such as peeling of the ink receiving layer occur. Also, even if a clear embossed pattern can be produced with an opaque ink receiving layer by any method, in that case,
The height difference between the concave portions and the convex portions on the surface of the ink receiving layer is large, which adversely affects the printing quality depending on the picture. On the other hand, when the opacity of the ink receiving layer is low, the embossed pattern of the base material can be seen as described above, so that no irregularities are required on the surface of the ink receiving layer, which is preferable in terms of printing quality.

Next, as the binder resin, polyvinyl alcohol, polyvinyl butyral, gelatin, polyvinyl acetal, carboxymethyl cellulose, polyvinyl pyrrolidone, styrene-acryl copolymer, ethylene-vinyl acetate copolymer, styrene-butadiene rubber, polyurethane resin And acrylic resin.
These can be used alone or as a mixture. In particular, polyvinyl alcohol is preferable in terms of transparency and strength of the receiving layer.

The thickness of the ink receiving layer is preferably from 3 to 20 μm, more preferably from 5 to 10 μm.

In the ink receiving layer of the present invention, the above-mentioned pigment components, binders, additives and the like are appropriately used in combination according to the purpose and purpose, but it is necessary to adjust the opacity to 50% or less. It is. The opacity in the present invention is opacity according to JIS P8138 as described above. When the opacity exceeds 50%, the embossed pattern becomes difficult to see, and does not meet the purpose of the present invention. More preferably, the opacity is 20% or less.

As additives, a surfactant, an antistatic agent, an antifoaming agent, an ultraviolet absorber and the like can be contained as required.

[0025]

The present invention is as described above. According to the ink jet recording sheet of the present invention, the base material is given a unique appearance and texture by embossing and can be seen through the ink receiving layer. In addition, since it is excellent in printing suitability, it is possible to achieve a unique effect that a variety of designs can be widened and a design effect can be enhanced. Therefore, the inkjet recording sheet of the present invention has an effect that it can be suitably used in fields and applications where design is required.

[0026]

Next, examples of the ink jet recording sheet of the present invention and comparative examples will be described. In the following description, “parts” indicates “parts by weight” and “%” indicates “% by weight”.

(Example 1) A synthetic paper having a thickness of 120 µm (manufactured by Chisso Corporation; trade name: Carrele FNR-120) was used as a base material. The specific gravity of this product is 0.68, which is a foamed plastic film. A test embossing machine (trade name: VW151) manufactured by Sakai Seisakusho Co., Ltd.
The embossed composition having the following composition was sufficiently stirred and dispersed with a 00 mm plate to obtain a coating liquid for the ink receiving layer. Water 519 parts Polyvinyl alcohol (manufactured by Kuraray Co., Ltd .: PVA235) 5% aqueous solution 330 parts Fine particle silica 58 parts (manufactured by Nippon Aerosil Co., Ltd .: average particle diameter of primary particles of Aerosil 300 7 nm) Dicyandiamide polycondensate 17 parts (Nichika Chemical Co., Ltd .: Neofix E-117) 77 parts of isopropyl alcohol The above-mentioned coating solution was applied to the above-mentioned base material so as to have a coating thickness of 20 μm to obtain a sheet of Example 1.

(Example 2) A sheet was obtained in the same manner as in Example 1 except that a synthetic paper having a thickness of 130 µm (manufactured by Oji Yuka Synthetic Paper Co., Ltd .; trade name: Yupohigloss GFG130) was used as a base material. . This synthetic paper (Yupo High Gloss GFG130)
It has a specific gravity of 0.79 and is a foamed plastic film. It has a matte surface and a glossy surface. In this embodiment, the matte surface is embossed.

Comparative Example 1 Polypropylene film having a thickness of 100 μm (manufactured by Nimura Chemical Industry Co., Ltd .; trade name: PB-260)
100) was used as a substrate. The specific gravity of this film is O.90, not a foamed plastic film. This substrate was embossed in the same manner as in Example 1 to obtain a substrate of Comparative Example 1. The brand of fine-particle silica was Mizukasil (trade name) manufactured by Mizusawa Chemical Industry Co., Ltd.
Mizukasil P-78F average primary particle size 12,000nm)
Except having replaced with, the same composition as in Example 1 was sufficiently stirred,
It was dispersed to form a coating liquid for the ink receiving layer. On the above substrate,
The above coating liquid was applied so that the coating thickness became 20 μm, and a sheet of Comparative Example 1 was obtained.

The sheets of Examples 1 and 2 and the sheet of Comparative Example 1 were evaluated by the following methods. First, the relationship between the pressure at the time of embossing and the sharpness of the embossed pattern was evaluated for the base material of each sheet. The pressure was measured by linear pressure kg / cm, and the sharpness of the embossed pattern was measured by surface roughness Ra (μm). The measurement results are as shown in Table 1.

[0031]

[Table 1]

As is clear from Table 1, the substrate of the sheet of Example 1 had a very clear embossed pattern.
Although the substrate of the sheet of Example 2 was inferior to the substrate of the sheet of Example 1, a clear embossed pattern was obtained. In contrast, the base material of the sheet of Comparative Example 1 did not have a clear embossed pattern.

Next, the coating liquid used for the sheet of Example 1 and the coating liquid used for the sheet of Comparative Example 1 were mixed with an opacity of 13.O.
% To 16.0% of transparent PET so that the coating thickness was 20 μm, and the opacity according to JIS P 8138 was measured. Table 2 shows the measurement results.

[0034]

[Table 2]

In the above, the base material and the coating layer before coating were separately evaluated.
When each sheet of Comparative Example 1 was visually observed, it was as follows. That is, in the sheet of Example 1, a very clear pattern of the base material was seen with almost no damage even through the coating layer, and as a result, a recording sheet having a very high design property was obtained. The sheet of Example 2 was clear although the embossed pattern of the substrate was inferior to the sheet of Example 1,
It was almost intact even through the coating layer and became a recording sheet having high design properties. In the sheet of Comparative Example 1, the embossed pattern of the base material was unclear, and when it was seen through the coating layer, it was slightly more difficult to see, so that the recording sheet was poor in design.

Next, an ink jet printer (manufactured by Hewlett-Packard Japan; product name: HP Design)
jet2000CP), and printing was performed with dye ink. It was confirmed by visual observation that no bleeding occurred and that the color developability was good. No bleeding occurred in any of the sheets of Example 1, Example 2 and Comparative Example 1, and the color developability was good. Was also good.

Table 3 shows the results of comprehensive evaluation of each sheet of Example 1, Example 2, and Comparative Example 1.

[0038]

[Table 3]

Claims (3)

[Claims] 1. An ink jet recording sheet having at least a substrate and an ink receiving layer, wherein the substrate is
Specific gravity is 0.5 to 0.85, made of embossed plastic film, and JIS of the ink receiving layer
An ink jet recording sheet having an opacity of 50% or less according to P 8138. 2. The ink receiving layer according to claim 1, wherein the average particle size of the primary particles is
2. The ink jet recording sheet according to claim 1, which contains 7 nm to 40 nm fine particle silica. 3. The ink jet recording sheet according to claim 1, wherein the plastic film is a foamed plastic film.