JPH04308786A - Recording sheet and recorded matter - Google Patents

Abstract

PURPOSE:To obtain a recording sheet having antistatic properties, little possibility of being wound into a machine, no possibility of having sticking properties and stains caused by the adhesion of an oil from feed rollers, heating rollers, and the like, and an ease of release even in the stacked state after printing. CONSTITUTION:In a recording sheet provided with a dye adsorbing layer on a substrate, a recording sheet provided with a porous alumina hydrate layer on the surface of the substrate on the opposite side to the dye adsorbing layer. A recorded matter obtained by adsorbing a dye in the dye adsorbing layer of said recording sheet.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording sheets and recorded materials.

0002

2. Description of the Related Art In recent years, overhead projectors (hereinafter referred to as OHP) have been increasingly used in place of conventional slides at conferences and the like. In such a case, an image is formed on a transparent recording sheet by handwriting or using a printer such as an electrostatic transfer method or an inkjet method.

Conventionally, as an OHP recording sheet, a plastic sheet such as polyethylene terephthalate, or a sheet whose surface has been processed to easily absorb dyes has been used.

0004

[Problem to be solved by the invention] Since these OHP recording sheets use plastic sheets as the base material, they are easily charged with electricity and are often caught in the machine when the recording sheet is automatically fed by the machine. . Furthermore, the sheet may become sticky or dirty due to oil adhering from conveyance rollers, heating rollers, etc.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording sheet that is compatible with a machine and can produce recorded matter with high color density and high durability.

[0006]

[Means for Solving the Problems] The present invention provides a recording sheet in which a dye adsorption layer is provided on the recording surface of a substrate, and a porous layer is provided on the side of the substrate opposite to the dye adsorption layer. A recording sheet provided with an alumina hydrate layer is provided.

In the present invention, the porous alumina hydrate layer on the opposite side to the surface provided with the dye adsorption layer provides the sheet with appropriate electrical conductivity and oil absorption.

The porous alumina hydrate on the opposite side to the surface on which the dye adsorption layer is provided is pseudoboehmite (AlO(OH)
) is preferred. A porous alumina hydrate layer has sufficient absorption when its pore structure consists essentially of pores with a radius of 10 to 100 Å and a pore volume of 0.3 to 1.0 cc/g. It is preferable because it has properties and transparency. At this time, if the base material and the dye adsorption layer are transparent, a transparent recording sheet can also be obtained.

Desirably, in addition to these physical properties, the average pore radius of the alumina hydrate layer is 15 to 50 Å, and the volume of pores having a radius of ±10 Å of the average pore radius is the total pore volume. If it is 45% or more, it is particularly preferable from the viewpoint of achieving both absorbency and transparency. The average pore radius is 15~
It is further preferred that the volume of pores having a radius of 30 Å and ±10 Å of the average pore radius is 55% or more of the total pore volume. Note that the pore radius distribution in the present invention is measured by a nitrogen adsorption/desorption method.

[0010] The thickness of the alumina hydrate layer on the opposite side to the surface on which the dye adsorption layer is provided is appropriately selected depending on the specifications of each printer, etc., but it is preferable that each layer adopts a thickness of 0.5 to 50 μm. . The thickness of the alumina hydrate layer is 0.5 μm
If it is less than 50 μm, the effect of the present invention may not be fully expressed, and if it exceeds 50 μm, the transparency of the alumina hydrate layer may be impaired or the strength of the layer may be reduced, which are both undesirable. .

[0011] The means for forming the alumina hydrate layer on the substrate is, for example, adding a binder to alumina hydrate to form a slurry, and using a roll coater, an air knife coater, a blade coater, a rod coater, a bar coater, a comma coater, etc. A method can be adopted in which the coating is applied using a lacquer and dried.

As the binder, organic substances such as starch and modified products thereof, polyvinyl alcohol and modified products thereof, SBR latex, NBR latex, carboxymethyl cellulose, hydroxymethyl cellulose, and polyvinylpyrrolidone can be used. The amount of binder used is preferably about 5 to 50% by weight of the alumina hydrate. If the amount of binder used is less than 5% by weight, the strength of the alumina hydrate layer may be insufficient, and conversely, if it exceeds less than 50% by weight, the adsorption of the dye will be insufficient. Each of these is undesirable because there is a risk.

[0013] In the present invention, the base material is not particularly limited, and various materials can be used. Specifically, various plastics or papers such as polyester resins such as polyethylene terephthalate and polyester diacetate, polycarbonate resins, and fluorine resins such as ETFE can be preferably used. For OHP recording sheets, the substrate must be transparent, but opaque substrates can also be used. Further, for the purpose of improving the adhesive strength of the alumina hydrate layer, corona discharge treatment, undercoating, etc. can also be performed.

In the present invention, the dye adsorption layer is also preferably a porous alumina hydrate. In particular, it absorbs and fixes pigments well,
Due to its good transparency, pseudoboehmite (AlO(
OH) ) is preferred.

[0015] The alumina hydrate layer of the dye adsorption layer has a pore structure substantially consisting of pores with a radius of 10 to 100 Å and a pore volume of 0.3 to 1.0 cc/g. is preferable because it has sufficient absorbency and the alumina hydrate layer is also transparent. Desirably, in addition to these physical properties, the average pore radius of the alumina hydrate layer is 15 to 50.
Å and the volume of pores having a radius of ±10 Å of the average pore radius is 45% or more of the total pore volume, which is particularly preferable from the viewpoint of achieving both fixability and transparency. The average pore radius is 15 to 30 Å, and the average pore radius is ±10 Å.
It is further preferred that the volume of the pores having a radius of 55% or more of the total pore volume is 55% or more of the total pore volume.

The thickness of the dye adsorption layer is appropriately selected depending on the specifications of each printer, but it is preferably 0.5 to 50 μm. If the thickness of the dye adsorption layer is less than 0.5 μm, the dye may not be adsorbed sufficiently.
If it exceeds 50 μm, the transparency of the dye adsorption layer may be impaired or the strength of the layer may be reduced, which is not preferable.

[0017] As the means for adsorbing the dye on the base material, the same method as for the back side is preferably used.

The recording sheet of the present invention can be suitably used as a transparent sheet such as an OHP recording sheet. Not only that, even opaque materials have the effects of the present invention. Additionally, if a transparent substrate is used and a transparent porous alumina hydrate layer is provided on the opposite side of the surface on which the dye adsorption layer is provided, the image of the dye adsorption layer can be observed through the transparent substrate. .

[0019]

【Example】

[Example 1] A glass reactor with a capacity of 2000 cc was charged with 900 g of water and 676 g of isopropyl alcohol.
The liquid temperature was heated to 75°C using a mantle heater. 306 g of aluminum isopropoxide was added while stirring, and hydrolysis was carried out for 5 hours while maintaining the liquid temperature at 75 to 78°C. Thereafter, the temperature was raised to 95°C, 9 g of acetic acid was added, and the temperature was maintained at 75 to 78°C for 48 hours to peptize. This liquid was further concentrated to 900 g to obtain a white sol. The dried material of this sol was pseudo-boehmite.

1 part by weight of polyvinyl alcohol was added to 5 parts by weight of this alumina sol, and water was further added to prepare a slurry having a solid content of about 10%. This slurry was coated onto a sheet base material made of polyethylene terephthalate (thickness: 100 μm) subjected to corona discharge treatment using a bar coater so that the dry layer thickness was 10 μm, and dried. Next, the above-mentioned alumina sol was applied to the opposite side in the same manner so that the dry film thickness was 5 μm, and dried to obtain a recording sheet. The average pore radius of the alumina hydrate layer obtained on the substrate was 20 Å, with a pore radius of 10 to 3
The 0 Å pore volume was 60% of the total pore volume.

Regarding the above-mentioned recording sheet, an electrostatic transfer type electrophotographic digital copying machine (Pixel DI manufactured by Canon Inc.
A solid pattern of red, yellow, and blue was continuously printed using the printer O). When I observed the back side of the printed side of the recording sheet that overlapped with the printed part of the pattern, I found that
There was no sticky feeling at all. Further, after printing, the overlapping recording films were allowed to stand, and after 3 hours, the overlapping films were peeled off, and the overlapping films could be easily peeled off. There was no sticky feeling on the printed part.

[0022]

[Effects of the Invention] The recording sheet of the present invention has suppressed electrification properties and can be less likely to be caught in a machine. Furthermore, since this layer adsorbs oil adhering from conveyance rollers, heating rollers, etc., the sheet does not become sticky or dirty. When the recording sheets are piled up, the recording sheets do not become difficult to peel off from each other. Furthermore, in the case of printing methods that use ink containing a large amount of solvent, such as inkjet printers, the alumina hydrate layer on the opposite side of the printed surface absorbs the solvent in the overlapping part, so it is continuous. Even if the recording sheets printed using the same method are stacked on top of each other immediately, they will not stick together. Therefore, recorded matter continuously printed by a machine can be stably obtained.

Claims (3)

[Claims] Claim 1: In a recording sheet in which a dye adsorption layer is provided on a substrate, on the opposite side of the substrate to the surface on which the dye adsorption layer is provided,
A recording sheet with a porous alumina hydrate layer. 2. The recording sheet according to claim 1, wherein the dye adsorption layer is a porous alumina hydrate. 3. A recorded matter in which a dye is adsorbed to the dye adsorption layer of the recording sheet according to claim 1 or 2.