JP3398479B2 - Recording sheet and recorded matter - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates, about the recording sheet and the recording material.

[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, ordinary paper cannot obtain sufficient absorbency and resolution, nor can it be transparent. Therefore, for example, as in JP-A-2-276670, an inorganic porous layer is formed on a substrate. A recording sheet in which the above is formed has been proposed.

[0003]

The recording sheet having the above-mentioned inorganic porous layer has good ink absorbability and good dye fixing property. However, in the case of the recording sheet having this inorganic porous layer, there is a case where the color fades during storage after printing.

Therefore, the present invention provides a recording sheet which has a good ink absorbency and a good dye fixing property, and which does not fade even after long-term storage after printing. With the goal.

[0005]

The present invention provides, on a substrate, one or more compounds selected from the group consisting of thiourea derivatives, thiosemicarbazide derivatives and thiocarbohydrazide derivatives (hereinafter referred to as group A compounds). and selected from the group consisting of iodine, iodide, dithiocarbamates, from thiocyanate salt <br/> and thiocyanate esters 1
Contains one or more compounds (hereinafter referred to as group B compounds)
Provided is a recording sheet having an ink absorbing porous ink receiving layer. The present invention also relates to the above-mentioned ink-absorbing porous ink receiving layer (hereinafter, simply referred to as a porous ink receiving layer.
( U ) provides the above-mentioned recording sheet which is a layer having a structure in which pseudo-boehmite is bound with a binder.

Further, the dye in the porous ink-receiving layer of the recording sheet described above that provides recorded matter borne.

The thiourea derivative, the thiosemicarbazide derivative and the thiocarbohydrazide derivative of the group A compound function as an anti-fading agent and prevent the fading of the ink during storage after printing. Although the function of this anti-fading agent is not clear, it is considered that the anti-fading agent prevents the fading due to a trace gas in the atmosphere. The thiourea derivative, the thiosemicarbazide derivative and the thiocarbohydrazide derivative in the group A compound have excellent anti-fading effect even when they are used alone. However, if these compounds are used in combination, a more excellent effect can be obtained. You can

Iodine, iodide, dithiocarbamate, thiocyanate, thiocyanate of group B compound
Acts as extinction agent, it has the anti-fading effect. In addition,
A quencher is a substance that acts and deactivates active singlet oxygen generated in the presence of oxygen. In the group B compound,
More preferred are iodide, dithiocarbamate and thiocyanate.

Although the group A compound and the group B compound have an anti-fading effect alone, they are used in combination in the present invention . As a result, it has a higher effect of preventing discoloration as compared with the case where each is used alone. Further, as the B group compound, in the case of using iodine or iodide, there was the recording sheet by iodine Ru is colored, A group compound also has the effect of preventing the coloring.

Further, as the group B compound, one or more kinds selected from the group consisting of iodine and iodide and one or more kinds selected from the group consisting of dithiocarbamate, thiocyanate and thiocyanate are used in combination. This is preferable because the effect of preventing discoloration is further enhanced.

The recording sheet of the present invention is particularly preferably used as a recording medium for an ink jet printer. The recording sheet of the present invention is particularly excellent in ink absorptivity and fixability, and thus can express a clear color and high color density,
Moreover, it is possible to form sharp dots.

Of the group A compounds, the thiourea derivative is preferably thiourea, N-methylthiourea, N,
N'-dimethylthiourea, tetramethylthiourea, etc. are used. As the thiosemicarbazide derivative, thiosemicarbazide, N-methylthiosemicarbazide, N-phenylthiosemicarbazide and the like are preferably used. As the thiocarbohydrazide derivative, thiocarbohydrazide, N-methyl-N'butylthiocarbohydrazide and the like are preferably used.

As the iodide of the group B compounds, metal iodides such as potassium iodide and sodium iodide are preferably used. The dithiocarbamates, preferably, potassium dimethyl dithiocarbamate, or the like is used et <br/> Re that sodium diethyldithiocarbamate. As the thiocyanate, sodium thiocyanate, potassium thiocyanate and the like are preferably used.

As a method of applying the group A compound and the group B compound to the porous ink receiving layer, a solution of the group A compound or the group B compound dissolved in an appropriate solvent is added to the porous ink receiving layer formed in advance. A method of applying by dipping or spraying is preferably adopted . A method of previously mixing the Group A compounds and the group B compound in the raw material to form a multi-porous ink-receiving layer can be employed.

The total content of the group A compound and the group B compound is 0.01 to 0.01 based on the weight of the porous ink receiving layer.
It is preferably 10% by weight. The total content is 0.
If the amount is less than 01% by weight, the effect of the present invention is not sufficiently exhibited, and the ink may be discolored, which is not preferable. If the total content exceeds 10% by weight, the absorptivity of the porous ink receiving layer may be impaired, which is not preferable. The total content of the group A compound and the group B compound is more preferably 0 . It is 1 to 3% by weight.

[0016] The content of the group A compounds, and to the total content of Group A compound and Group B compound 1 0-90 wt%
Is preferred. If the content deviates from the above range, the effect of using the group A compound and the group B compound together may not be exhibited, which is not preferable.

In the present invention, the porous ink receiving layer is
An inorganic 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 carry the dye, and only a printed matter with a low color density may be obtained, which is not preferable, and if it is too thick, the strength of the porous ink receiving layer will decrease. or, also transparency of prints transparency decreases is not preferable because there is to Ruosore or impaired texture. Preferred thickness of porous ink receiving layer
Is 1 to 50 μm.

The porous ink-receiving layer is preferably a structure in which bonded inorganic particles in Bas-in <br/> loaders. As the material of the inorganic particles, silica or alumina or a hydrate of these is preferable. Among these materials , pseudo- boehmite is
Particularly preferred. This is because the porous layer made of pseudo-boehmite has good absorbency and selectively and well adsorbs the dye, so that a clear recorded matter with high color density can be obtained by using various recording methods. Where pseudo-boehmite is
Alumina hydrate represented by the composition formula of AlOOH,
The porous layer made of pseudo-boehmite is an aggregate having a pore structure.

The porous ink receiving layer is made of pseudo-boehmite .
Layer (hereinafter referred to as pseudo-boehmite porous ink receiving layer)
If it is, the total content of Group A compound and Group B compound, Ri per pseudoboehmite 1 g 0. It is preferably from 05 to 50 mg. A more preferable range is 0 . 1-20m
It is g.

The pseudo-boehmite porous ink-receiving layer has a pore structure of pores having a radius of substantially 1 to 10 nm and a pore volume of 0.3 to 1.0 cc / g. It is preferable because it has sufficient absorbency and transparency. If the pseudo-boehmite porous ink receiving layer having a pore structure in this range is used, when the substrate is transparent,
A transparent recording sheet can be obtained. If the substrate is opaque, Ru can grant The required physical properties of the absorbent of the ink without impairing the texture of the substrate to the recording sheet. Further, it is more preferable that the average pore radius of the pseudo-boehmite porous ink receiving layer is in the range of 3 to 7 nm. The pore size distribution is measured by the nitrogen adsorption / desorption method.

In order to produce the pseudo-boehmite porous ink receiving layer having a pore structure as described above, it is preferable to use a boehmite sol obtained by hydrolyzing an aluminum alkoxide. As a means for forming a pseudo-boehmite porous ink-receiving layer on a substrate, the addition of Ba in <br/> Zehnder boehmite sol to form a slurry, a roll coater, air knife coater, a blade coater, a rod coater, a bar coater, etc. It is possible to preferably employ a method of coating on a substrate by using and drying.

Examples of the binder for the porous ink receiving layer include starch and its modified products, polyvinyl alcohol and its modified products, SBR (butadiene styrene rubber) latex, NBR (butadiene acrylonitrile rubber) latex, hydroxycellulose, polyvinylpyrrolidone and the like. Organic substances 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.

[0023] In the present invention, cut with use various ones as substrate. For example, polyesters such as polyethylene terephthalate, polycarbonate, plastic of fluororesin or the like of ETFE, etc., or Ru <br/> can in a suitably used paper. 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.

[0024]

Example A glass reactor having a capacity of 2 liters was charged with water 54
0 g and 676 g of isopropyl alcohol were charged and the liquid temperature was heated to 75 ° C. by a mantle heater. Add 306 g of aluminum isopropoxide with stirring,
Hydrolysis was carried out for 5 hours while maintaining the liquid temperature at 75 to 78 ° C. After that, the temperature was raised to 95 ° C., 9 g of acetic acid was added, and
The temperature was kept at 75 to 78 ° C. for peptization. Further, this solution was concentrated to 900 g to obtain a white sol. The dried product of this sol was pseudo-boehmite.

[0025] while handling polyvinyl alcohol 1 part by weight of this alumina sol 5 parts by weight, further adding water, to prepare a solid content of about 10% of the slurry. This slurry was treated with corona discharge treated polyethylene terephthalate (thickness 1
On a substrate made of 00μm), the layer thickness when dry using a bar coater the coating so that the 30 [mu] m, to form a dried擬Be <br/> Mai preparative multi-porous ink-receiving layer.

The coated surface of the recording sheet obtained as described above was dipped in an aqueous solution or an ethanol solution having various concentrations of the treatment chemicals shown in Tables 1 to 5 to uniformly coat the solution. This was hung vertically and air-dried, and then heated and baked at 140 ° C. for 4 minutes in a drum dryer. The ratios of the group A compound and the group B compound in Tables 1 to 5 are weight ratios. The treatment liquid concentrations in Tables 1 to 5 are the total weight percentages of the mixture of the group A compound and the group B compound.

A portion of the recording sheet thus obtained is cut out and immersed in an aqueous hydrochloric acid solution for 12 hours, and the solution is quantified by an ultraviolet-visible spectrum absorption spectrophotometric method or ion chromatography for recording. The amount (supported amount) of the compound in the porous ink receiving layer of the sheet was determined. When an ink jet printer was used for recording on the recording sheet of this example which had been subjected to the chemical treatment as described above, the ink absorbing property and the dye fixing property were excellent.

Further, 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 Tables 1-5. For comparison, the degree of discoloration was examined in the same manner for the recording sheet that was not treated with the chemicals. The results are also shown in Tables 1-5 as "untreated".

In Tables 1 to 5, the carrying amount is the total amount of the group A compound and the group B compound carried in the recording sheet, and the unit thereof is mg per 1 g 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 high degree of fading (x).

[0030]

[Table 1]

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

[Table 4]

[0034]

[Table 5]

When recording was carried out on the recording sheet of this example using an ink jet printer, the ink absorbency and the dye fixability were excellent.

[0036]

The recording sheet of the present invention has good ink absorbability and good dye fixing property. Moreover, it does not fade 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 (3)

(57) [Claims] 1. A substrate comprising one or more compounds (A) selected from the group consisting of thiourea derivatives, thiosemicarbazide derivatives and thiocarbohydrazide derivatives, and iodine, iodide, dithiocarbamate, and thiocyanate. A recording sheet having an ink-absorbing porous ink-receiving layer containing one or more compounds (B) selected from the group consisting of acid salts and thiocyanates. 2. The recording sheet according to claim 1, wherein the ink-absorbing porous ink-receiving layer is a layer in which pseudo-boehmite is bound with a binder. Wherein Yi recording sheet according to claim 1 or 2, wherein
Recording material in which a dye is supported on the ink- absorbing porous ink-receiving layer.