JPH0768919A - Recording sheet and recording article - Google Patents

Abstract

PURPOSE:To obtain a recording sheet good in ink absorbability and dye fixing properties and generating no fading during long-term preservation after printing by providing a porous ink receiving layer containing at least one component selected from an ultraviolet absorber, an antioxidant and quencher on a base material. CONSTITUTION:A recording sheet is constituted by providing a porous ink receiving layer containing one or more kinds of a components selected from an ultraviolet absorber, an antioxidant and a quencher on a base material. At this time, the porous ink receiving layer is composed of pseudo-boehmite. The substance contained in the porous ink receiving layer is composed of the mixture of the ultraviolet absorber, the antioxidant and the quencher. Further, the recording sheet is a recording medium for an ink jet printer. The porous ink receiving layer containing one or more kinds of the ultraviolet absorber, the antioxidant and the quencher is provided on the base material and a dye is supported on the porous ink receiving layer to constitute a recording article. By this constitution, the ink absorbability and dye fixing properties are together improved and fading is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet and recorded matter.

[0002]

2. Description of the Related Art Images are often formed using various printers such as an ink jet system, an electrostatic transfer system, and a sublimation type thermal transfer system. In this case, on plain paper,
Since sufficient absorbency and resolution cannot be obtained and a transparent material cannot be obtained, a recording sheet in which an inorganic porous layer is formed on a substrate is proposed, for example, as in JP-A-2-276670. Has been done.

[0003]

As described above, a recording sheet having a porous layer having a good ink absorbability and a good dye fixing property can be stored after printing and during storage. There was a case of fading. It is an object of the present invention to obtain a recording sheet having good ink absorbency and good dye fixing property, which does not fade even after storage for a long time after printing.

[0004]

The present invention provides a recording sheet having, on a substrate, a porous ink receiving layer containing at least one selected from an ultraviolet absorber, an antioxidant and a quencher. .

In the present invention, the ultraviolet absorber means a substance which absorbs ultraviolet rays and re-radiates the energy thereof as harmless heat energy and does not deteriorate itself. The antioxidant is a substance having a function of preventing deterioration of the dye due to a radical chain reaction, decomposition of generated peroxide, or deterioration of the dye due to ozone in the atmosphere. A quencher is a substance that acts on active singlet oxygen generated in the presence of oxygen to deactivate it.

As the ultraviolet absorber, those of benzotriazole type, benzophenone type, benzoate type and cyanoacrylate type can be preferably used. As the antioxidant, hindered phenol-based, phosphorus-based, and sulfur-based antioxidants can be preferably used. As the quencher, organic nickel compounds and metal halides can be preferably used. Also,
It is possible to use one type of substance that has more than one of these functions.

Commercially available ultraviolet absorbers or antioxidants include, specifically, Sumilizer, Sumisorb (trade name of Sumitomo Chemical Co., Ltd.), ADEKA STAB (trade name of Asahi Denka Co., Ltd.), IRGANOX, TINUVIN (Ciba.
Geigy product name), CYASORB, CYANOX
(Product name of Nippon Cyanamid Co., Ltd.), UV-CHECK
(Trade name of Ferro Chemicals, Inc.) and the like can be used. Specific examples of the quenching agent include nickel salts such as nickel dibutyldithiocarbamate, metal halides such as potassium iodide, sodium iodide, potassium bromide and sodium bromide, or iodine.

As a method of applying one or more kinds selected from ultraviolet absorbers, antioxidants and quenchers (hereinafter collectively referred to as the present stabilizer) to the porous ink receiving layer, a porous ink receiving layer formed in advance is used. A method in which a solution in which the stabilizer is dissolved in a suitable solvent is applied to the layer by an immersion method or a spray method is preferably adopted. Alternatively, a method in which the present stabilizer is mixed with the raw material for forming the porous ink receiving layer can also be adopted.

The content of the stabilizer is preferably 0.01 to 10% by weight based on the weight of the porous ink receiving layer. If the content of the present stabilizer is less than 0.01% by weight, the effect of the present invention is not sufficiently exhibited, and the discoloration of the ink may occur, which is not preferable. When the content of the present stabilizer exceeds 10% by weight, not only coloring due to the present stabilizer itself becomes a problem but also the absorptivity of the porous layer may be impaired, which is not preferable. The more preferable content of the present stabilizer is 0.1 to 1% by weight.

The ultraviolet absorber, the antioxidant and the quencher are effective even if they are used alone, but the effects can be further enhanced by combining them. In particular, it is preferable to use a mixture of an ultraviolet absorber or an antioxidant and a quencher. The content of the ultraviolet absorber, the antioxidant, and the quencher at the time of forming the composite is preferably 0.01 to 10% by weight, more preferably 0.1 to 0.5% by weight.

In the present invention, the porous ink receiving layer is
It is a porous layer capable of absorbing and fixing ink during recording.
If the thickness of the porous ink-receiving layer is too thin, it may not be able to sufficiently support the dye, and only a printed matter having a low color density may be obtained, which is not preferable. Conversely, if it is too thick, the strength of the porous ink-receiving layer will decrease. Or the transparency may be reduced to impair the transparency or texture of the printed matter, which is not preferable. The preferable thickness of the porous ink receiving layer is 1 to 50 μm.

The porous ink receiving layer preferably has a structure in which inorganic particles are bound by a binder. As a material for the inorganic particles, silica, alumina or a hydrate thereof is preferable. In particular, the pseudo-boehmite porous layer is preferable because it has good absorbability and selectively and well adsorbs the dye, and thus various recording methods can be used to obtain a clear recorded matter with high color density. Here, pseudo-boehmite is an alumina hydrate represented by the composition formula of AlOOH, and is an aggregate having a pore structure.

When the porous layer is pseudo-boehmite,
The ultraviolet absorber, antioxidant, and quencher are preferably 0.01 to 30 mmol per mol of pseudoboehmite. A more preferable range is 1 to 20 mmol.

The pseudo-boehmite porous layer has a pore structure whose pores substantially have a radius of 10 to 100Å and a pore volume of 0.3 to 1.0 cc / g. It is preferable because it has properties and is transparent. At this time, if the base material is transparent, a transparent recording sheet can be obtained. When the substrate is opaque, it is possible to impart the required physical properties without impairing the texture of the substrate. In addition to these physical properties, it is further preferable that the pseudo-boehmite porous layer has an average pore radius of 30 to 70Å. In addition,
The pore size distribution is measured by the nitrogen adsorption / desorption method.

In order to produce a pseudo-boehmite porous layer having a pore structure as described above, it is preferable to use a boehmite sol obtained by hydrolyzing an aluminum alkoxide. The means for applying onto the substrate is a boehmite sol, preferably with a binder added to form a slurry, which is applied onto the substrate using a roll coater, an air knife coater, a blade coater, a rod coater, a bar coater or the like, and dried. The method can be preferably adopted.

As the binder, starch and its modified products, polyvinyl alcohol and its modified products, SBR latex, NBR latex, hydroxycellulose,
Organic substances such as polyvinylpyrrolidone can be used. If the amount of the binder used is too small, the strength of the porous ink-receiving layer may be insufficient. On the contrary, if the amount is too large, the amount of ink absorbed and the amount of dye supported may be low. It is preferably about 50% by weight.

In the present invention, various materials can be used as the base material. For example, polyester such as polyethylene terephthalate, polycarbonate, ETF
A plastic such as a fluorine-based resin such as E, or paper can be preferably used. These substrates may be subjected to corona discharge treatment or undercoating for the purpose of improving the adhesive strength of the porous ink receiving layer.

[0018]

【Example】

Example 1 A glass reactor having a capacity of 2000 cc was charged with 540 g of water and 676 g of isopropyl alcohol and heated to 75 ° C. by a mantle heater. While stirring, 306 g of aluminum isopropoxide was added, and the liquid temperature was adjusted to 7
Hydrolysis was carried out for 5 hours while maintaining at 5 to 78 ° C. Then, the temperature was raised to 95 ° C., 9 g of acetic acid was added, and the mixture was added for 48 hours to 7
The temperature was kept at 5 to 78 ° C for peptization. Then add 90 parts of this liquid.
Concentration to 0 g gave a white sol. The dried product of this sol was pseudo-boehmite.

To 5 parts by weight of this alumina sol, 1 part by weight of polyvinyl alcohol was added, and further water was added to prepare a slurry having a solid content of about 10%. This slurry was applied onto a base material made of polyethylene terephthalate (thickness 100 μm) that had been subjected to corona discharge treatment, using a bar coater so that the layer thickness when dried was 30 μm, and dried to form a boehmite porous material. Layers were formed.

The coated surface of the sheet obtained as described above was dipped in an aqueous solution or ethanol solution having various concentrations of the antioxidant shown in Table 1 and applied uniformly. This is hung vertically and air-dried.
It was heated and baked for a minute.

A part of the recording sheet thus obtained was cut out and immersed in a hydrochloric acid aqueous solution for 12 hours, and then the solution was subjected to absorption spectrometry by ultraviolet / visible spectrum or ion chromatography to determine the porosity of the recording sheet. The amount of antioxidant in the sample was quantified. In addition, a black ink containing hood black 2 was applied to the recording sheet and exposed indoors for 30 days to examine the degree of black fading. The results are shown in Table 1.

In Table 1, the unit of the concentration of the antioxidant in the treatment liquid is% by weight, and the unit of the amount of the antioxidant carried in the sheet is the number of milligrams per gram of pseudo-boehmite (AlOOH). The degree of fading was represented by three levels: high degree of fading (x), medium degree of fading (△), and low degree of fading (◯). The untreated sheet has a large degree of fading (x).

[0023]

[Table 1]

Example 2 The ultraviolet absorbent shown in Table 2 was applied to a recording sheet having a pseudo-boehmite porous layer obtained in the same manner as in Example 1.
Was applied in the same manner as in. The results of the same evaluations as in Example 1 are shown in Table 2.

[0025]

[Table 2]

Example 3 A recording sheet having a pseudo-boehmite porous layer obtained in the same manner as in Example 1 was treated with the same antioxidants and ultraviolet absorbers shown in Table 3 as in Example 1. Applied.
Table 3 shows the results of the same evaluations as in Example 1.

[0027]

[Table 3]

Example 4 The quenching agent shown in Table 4 was applied to the recording sheet having the pseudo-boehmite porous layer obtained in the same manner as in Example 1 in the same manner as in Example 1. The results of the same evaluations as in Example 1 are shown in Table 4.

[0029]

[Table 4]

Example 5 For coated paper obtained by coating porous silica on a paper substrate, the antioxidants shown in Table 5 were dipped in various concentrations of aqueous solutions or ethanol solutions and uniformly coated. . This is hung vertically and air-dried, then 140
C., and baked for 4 minutes.

The silica-coated paper thus obtained was evaluated in the same manner as in Example 1. The results are shown in Table 5. However, the amount of the antioxidant in the coated paper is the number of milligrams per gram of silica. The untreated silica-coated paper has a large degree of discoloration (x).

[0032]

[Table 5]

Example 6 The silica coated paper obtained in the same manner as in Example 5 was coated with the ultraviolet absorbers shown in Table 6 in the same manner as in Example 5. Table 6 shows the results of the same evaluations as in Example 1.

[0034]

[Table 6]

Example 7 The silica-coated paper obtained in the same manner as in Example 5 was coated with the antioxidants and ultraviolet absorbers shown in Table 7 in the same manner as in Example 5. Table 7 shows the results of the same evaluations as in Example 1.

[0036]

[Table 7]

Example 8 The silica-coated paper obtained in the same manner as in Example 5 was coated with the quencher shown in Table 8 in the same manner as in Example 5. Table 8 shows the results of the same evaluations as in Example 1.

[0038]

[Table 8]

Example 9 The coated surface of the sheet obtained as in Example 1 is shown in Table 9
The solution was uniformly applied by immersing it in an aqueous solution of a 1: 1 weight ratio mixture of the agents shown in or an ethanol solution. This is hung vertically and air-dried.
It was heated and baked for a minute.

The total amount of the treatment chemicals in the porous material of the recording sheet thus obtained was quantified and the degree of fading was measured in the same manner as in Example 1. The results are shown in Table 9.

[0041]

[Table 9]

Example 10 Table 10 for the sheet obtained as in Example 1
The same treatment as in Example 9 was carried out except that the agents shown in (4) were used. Table 10 shows the evaluation results obtained in the same manner as in Example 1.

[0043]

[Table 10]

[0044]

The recording sheet of the present invention has good ink absorbability and good dye fixing property. Moreover, discoloration does not occur even after long-term storage. The recording sheet of the present invention is effective for various recording systems, but is particularly suitable for a recording medium for an inkjet printer.

Claims (6)

[Claims] 1. A recording sheet having, on a substrate, a porous ink receiving layer containing at least one selected from an ultraviolet absorber, an antioxidant and a quencher. 2. The recording sheet according to claim 1, wherein the porous ink receiving layer is pseudo-boehmite. 3. The substance contained in the porous ink-receiving layer is
The recording sheet according to claim 1 or 2, which is a mixture of an ultraviolet absorber or an antioxidant and a quencher. 4. The recording sheet according to claim 1, which is a recording medium for an inkjet printer. 5. A substrate is provided with a porous ink receiving layer containing at least one selected from an ultraviolet absorber, an antioxidant and a quencher, and the dye is carried on the porous ink receiving layer. Recorded material. 6. The recorded matter according to claim 5, wherein the porous ink receiving layer is pseudo-boehmite.