JPH071676A - Ps plate wrapping material - Google Patents

Abstract

PURPOSE:To recycle a PS plate wrapping material used for PS plate wrapping paper and the like. CONSTITUTION:A material shown by a sign 11 is a paper material made of kraft paper having a basis weight of 75g/m<2> and a pH of 5. On a top surface of the paper material 11 (an outer surface in wrapping a PS plate, or an upper side in the figure), a moisture-proof layer 21 is laminated. The moisture-proof layer 21 is made of an acrylate latex and paraffin wax and applied in the amount of 13g/m<2> (after drying). A light-shielding layer 31 is laminated on the moisture-proof layer 21. The light-shielding layer 31 is made of printing ink containing 35wt.% benzine yellow and applied in the amount of 10g/m<2> (after drying). On a rear surface of the paper material 11 (an inner surface coming into contact with a PS plate in wrapping the PS plate, or a lower side in the figure), a light-reflecting layer 41 is laminated for reflecting a light for the purpose of shielding the light. The light-shielding layer 41 is made of a clay coating pigment containing 40wt.% kaolin and is 5mum in thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PS plate packaging material used for PS plate packaging paper and the like.

[0002]

2. Description of the Related Art Conventionally, as wrapping paper for PS plates, aluminum kraft paper obtained by laminating kraft paper and aluminum foil with a polyethylene film, laminated paper obtained by laminating black polyethylene film containing carbon black and kraft paper, carbon For example, polyethylene-laminated paper in which light-shielding paper obtained by squeezing black into kraft paper and polyethylene film are laminated is used. In these wrapping papers, the aluminum foil, the black polyethylene film, and the light-shielding paper mainly secure the light-shielding property.

[0003]

Since the conventional PS plate wrapping paper described above is a composite material in which aluminum foil or polyethylene film is laminated on kraft paper, it cannot be recycled and is incinerated or landfilled as industrial waste. I had to do it.

An object of the present invention is to solve the above problems and provide a PS plate packaging material that can be recycled.

[0005]

Means for Solving the Problems The present invention has been earnestly studied for a material that can be recycled to achieve the above object, and is a moisture-proof paper that can be recycled as used paper (Japanese Patent Publication No. 55-22597). ) Was focused on. This moisture-proof paper has moisture-proof property, mechanical strength and suitability for packaging machine,
Although it is suitable as an S plate packaging material, there is no one having a light-shielding property.

The moisture-proof paper can be provided with a light-shielding property by applying carbon black, which has been conventionally used in PS plate packaging materials, but carbon black cannot be removed without a deinking step. In general corrugated board makers that do not have a deinking process, carbon black is recycled paper that is raised on the surface, and it is virtually impossible to recycle packaging materials. Further, carbon black has problems such as stains in the manufacturing process of packaging materials and difficulty in treating waste carbon black. Although it is possible to apply aluminum powder, the aluminum powder could not be removed even in the deinking process, and the aluminum powder floated on the surface of the recycled paper, so it could not be recycled.

[0007] Therefore, the present inventor diligently studied a light-shielding substance which does not impair the recyclability. As a result, P
It was found that it is not necessary for the S plate to shield light in a wide wavelength range from ultraviolet rays to infrared rays as in the case of aluminum foil or carbon black, and it is sufficient to shield only a specific wavelength range. That is, since the PS plate uses a diazo photosensitive material, and the photosensitive wavelength of this diazo photosensitive material is limited to 250 to 500 nm, a substance capable of absorbing or reflecting at least light in this wavelength range may be used. It has been found that such pigments and dyes capable of blocking light with a wavelength of 250 to 500 nm do not hinder recycling.

Regarding the wavelength range of light shielding, a laminated film for packaging a photosensitive paper which shields light of 100 nm or more (Japanese Patent Publication No. 58
No. 13902), there is a polyester container (USP 4,803,255) for food or the like which shields light in the ultraviolet region of 300 to 450 nm, but these are unrelated to the PS plate.

The present invention has been made on the basis of the above findings. The PS plate packaging material of the present invention selectively emits a paper material and light of 250 to 500 nm provided on the same surface of the paper material. It is characterized in that it has a light-shielding layer containing one or more pigments and dyes which shield light and a moisture-proof layer provided by applying an aqueous emulsion comprising a synthetic rubber latex and a wax emulsion.

The PS plate packaging material of the present invention is 250
By coating a light-shielding paper material in which one or more pigments and dyes that selectively shield light of ~ 500 nm are incorporated, and an aqueous emulsion composed of a synthetic rubber latex and a wax emulsion on the light-shielding paper material And a moisture-proof layer provided.

Pigments that selectively absorb light of 250 to 500 nm include yellow pigments such as yellow lead and benzidine yellow, and mixed pigments of red and yellow pigments such as fanar rose and carmine 6B. Dyes that selectively absorb light of 250 to 500 nm are also effective as light-shielding materials, but they are inferior to pigments in terms of the filling rate that prevents light transmission.

The light-shielding layer contains one or more of the above pigments and dyes. The content of the pigment or the like is preferably about ² to 5 g / m ² , and the resin used for the light shielding layer was a synthetic rubber latex or a synthetic binder such as PVA. The coating amount of the light shielding layer, including the resin, is preferably about 10 to 12 g / m ² (after drying). The light shielding layer is laminated by printing, coating or the like.

The moisture-proof layer is provided by applying an aqueous emulsion comprising a synthetic rubber latex or resin latex and a wax emulsion. Synthetic rubber-based latex is produced by emulsion polymerization of a butadiene monomer or a monomer having two or more double bonds and another monomer having a double bond, and has a compounding ratio of each component or a functional group such as a carboxyl group. There are various types depending on whether or not a group is introduced. For example, there are methyl methacrylate butadiene type latex, styrene-butadiene type latex, and acrylonitrile-butadiene type latex. As resin-based latex, acrylate latex (ACL), vinyl acetate (PVA)
C) and ethylene acetate vinyl latex (EVA).

Examples of the wax emulsion include paraffin wax emulsion and polyethylene wax emulsion.

The coating amount of the moisture-proof layer is preferably about 10 to 15 g / m ² , and the thickness is 5 to 5 because a part of the moisture-proof agent penetrates into the paper material.
The thickness is about 10 μm.

Examples of paper materials include kraft paper, kraft paper, high-quality paper, bleached kraft paper, and pure white roll paper. The paper material is to prevent the alkaline components of the moisture-proof layer from adversely affecting the quality of the PS plate, that is, to prevent alkaline substances from inhibiting the fading reaction of the PS plate and deteriorating the plate inspection performance after printing. Therefore, it is preferably acidic, and specifically, a pH range of 5.0 to 6.0 is preferable.

A light-shielding paper material is obtained by incorporating one or more pigments and dyes that selectively shield light of 250 to 500 nm into such a paper material.

The basis weight of the paper material is preferably about 70 to 83 g / m ² , and the basis weight of the light-shielding paper material containing pigments is 80 to 10 g / m ^2.
About 0 g / m ² is preferable.

If necessary, the paper material and the light-shielding paper material can be provided with a light-reflecting layer on the side opposite to the light-shielding layer, and the light-reflecting layer can make the light-shielding property more complete. The light reflecting layer contains clay coating pigments such as kaolin and calcium carbonate. The thickness of the light reflection layer is 10μ
m or less is preferable.

[0020]

In the packaging material for PS plates of the present invention, one or more of pigments and dyes that selectively block light of 250 to 500 nm are 250 to 5
It prevents the PS plate from being exposed to light of 00 nm and allows the paper material to be recycled without adversely affecting the recycling process.

[0021]

Embodiments of the PS plate packaging material according to the present invention will be described with reference to the drawings. 1 to 4 are respectively PS
It is a fragmentary sectional view of the plate packaging material. In the PS plate packaging material shown in FIG. 1, reference numeral 11 is a paper material made of kraft paper having a basis weight of 75 g / m ² and a pH of 5, and the surface side (PS
A moisture-proof layer 21 is laminated on the side that becomes the surface when the plate is packaged (upper side in the figure). This moisture-proof layer 21 is formed of acrylate latex and paraffin wax, and the coating amount is 13 g / m 2.
² (after drying). Then, the light-shielding layer 31 is formed on the moisture-proof layer 21.
The light-shielding layer 31 is formed of a printing ink containing 35% by weight of benzine yellow and has a coating amount of 10 g / m ² (after drying). Further, a light reflection layer 41 for the purpose of light shielding by reflection is laminated on the back side of the paper material 11 (the side that comes into contact with the PS plate when it is the inner surface when the PS plate is packaged, the lower side in the figure). The light reflection layer 41 is formed of a clay coating pigment containing 40% by weight of kaolin and has a thickness of 5 μm.

In the PS plate packaging material shown in FIG. 2, reference numeral 12 is a paper material made of kraft paper having a basis weight of 75 g / m ² and a pH of 5, and a moisture-proof light-shielding layer 51 is laminated on the surface side of the paper material 12. The moisture-proof light-shielding layer 51 is formed of a printing ink prepared by kneading a pigment into a moisture-proof agent composed of the acrylate latex and paraffin wax, and has a coating amount of 20 g / m ² (after drying). A light reflection layer 42 is laminated on the back surface side of the paper material 12. The light reflection layer 42 is formed of a clay coating layer containing kaolin as a main material and has a thickness of 5 μm.

In the PS plate packaging material shown in FIG. 3, reference numeral 13 is a paper material made of kraft paper having a basis weight of 75 g / m ² and a pH of 5, and a moisture-proof layer 22 is laminated on the surface side of the paper material 11. The moisture-proof layer 22 is formed of acrylate latex and paraffin wax and has a coating amount of 13 g / m ² (after drying). A light-shielding layer 32 is laminated on the moisture-proof layer 22, and the light-shielding layer 32 is formed of a printing ink containing 35% by weight of benzine yellow and has a coating amount of 10 g / m ² (after drying).

In the PS plate packaging material shown in FIG. 4, reference numeral 61 is a light-shielding paper material which shields light having a wavelength of 250 to 500 nm.
The light-shielding paper material 51 is a kraft paper having a basis weight of 75 g / m ² and a pH of 5 and a yellow dye incorporated therein. A moisture-proof layer 23 is laminated on the surface side of the light-shielding paper material 51. The moisture-proof layer 21 is formed of acrylate latex and paraffin wax and has a coating amount of 10 g / m ² (after drying).

[Evaluation of Recycling Suitability] The packaging material was sequentially sent to the disaggregation step, the screen step and the paper making step to produce recycled paper, and the surface of this recycled paper was observed. In the packaging materials of the examples, the yellow pigment remained and floated on the surface of the recycled paper, but there was no problem with the commercial value of the recycled paper.

[Evaluation I of Light-Shielding Performance] A PS plate was wrapped with a wrapping paper according to the present invention, and this wrapping body was put in an outer corrugated cardboard box and exposed outdoors for 5 days. The sunlight conditions are 4 to 5 hours under direct sunlight and 35 to 40 hours in the shade. Then, it was inspected whether there was a problem in printing, development and printing performance of the PS plate. The wrapping paper of the example had no problem.

[Evaluation of Light-Shielding Performance II] A PS plate was wrapped with the wrapping paper according to the present invention, and this wrapping body was placed under an indoor white fluorescent lamp (500
LUX) and exposed for 200 hours. Then, it was inspected whether there was a problem in printing, development and printing performance of the PS plate. The wrapping paper of the example had no problem.

[0028]

INDUSTRIAL APPLICABILITY The PS plate wrapping material of the present invention can be reused by recycling the paper material after use, while ensuring the light-shielding property of the PS plate to be packed.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an embodiment of a PS plate packaging material of the present invention.

FIG. 2 is a partial cross-sectional view of another embodiment of the PS plate packaging material of the present invention.

FIG. 3 is a partial cross-sectional view of another embodiment of the PS plate packaging material of the present invention.

FIG. 4 is a partial cross-sectional view of another embodiment of the PS plate packaging material of the present invention.

[Explanation of symbols]

 11, 12, 13 ... Paper material 21, 22, 23 ... Moisture-proof layer 31, 32 ... Light-shielding layer 41, 42 ... Light-reflecting layer 51 ... Moisture-proof light-shielding layer 61 ... Light-shielding paper material

Claims (2)

[Claims] 1. A paper material and a paper material provided on the same surface of the paper material.
A light-shielding layer containing one or more pigments and dyes that selectively shield 250-500 nm light and a moisture-proof layer provided by applying an aqueous emulsion composed of a synthetic rubber latex or a resin latex and a wax emulsion. PS packaging material characterized by having 2. A light-shielding paper material in which one or more pigments and dyes that selectively shield light of 250 to 500 nm are incorporated, and a synthetic rubber latex or a resin latex and a wax emulsion in the light-shielding paper material. And a moistureproof layer provided by applying an aqueous emulsion of