JP3435804B2 - Inkjet recording sheet - Google Patents

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 (hereinafter simply referred to as a recording sheet) and a 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, 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]

According to the present invention SUMMARY OF], on the substrate, sodium Ji Ossian acid and thiocyanate potassium
Contain one or more compounds selected from the group consisting of beam,
Inorganic particles and 5 to 50% by weight of the inorganic particles
There is provided a recording sheet having a porous ink-receiving layer having a constitution in which it is bound with an inder .

Further, according to the present invention, there is provided a recorded matter in which a dye is carried on the porous ink receiving layer of the above recording sheet.

Dithiocarbamate, thiuram salt, thiocyanates, and thiocyanate function as an anti-fading agent and prevent the fading of ink during storage after printing. The function of this anti-fading agent is not clear yet,
It is considered to stabilize other additives and prevent fading due to trace gases in the atmosphere.

These dithiocarbamates, thiuram salts, thiocyanates and thiocyanates have excellent anti-fading effect even when used alone. However, when a plurality of these compounds are used, a more excellent effect is obtained. Can be obtained. Further, by using these compounds in combination with a quenching agent composed of iodide or iodine, it is possible to obtain a greater effect of preventing discoloration, and it is also possible to prevent the recording sheet from being colored by the iodine quenching agent. The quencher is a substance that acts on active singlet oxygen generated in the presence of oxygen to deactivate it.

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.

The dithiocarbamate used as the anti-fading agent is preferably potassium dimethyldithiocarbamate, sodium diethyldithiocarbamate or the like, and the thiuram salt is preferably tetraethylthiuram disulfide or tetramethylthiuram monosulfide. is used, as the thiocyanate esters, preferably methyl thiocyanate, ethyl thiocyanate is used in the present invention, sodium Ji Ossian acid as a thiocyanate <br/>, thiocyanate potassium
Is used.

As the iodide used as a quencher, metal iodides such as potassium iodide and sodium iodide are preferably used.

In the present invention, the porous ink receiving layer may contain a hindered amine.

A method of applying to the porous ink-receiving layer one or more compounds selected from the group consisting of dithiocarbamate, thiuram salt, thiocyanates and thiocyanate (hereinafter referred to as the present anti-fading agent). Alternatively, as a method of applying a quenching agent composed of iodine or iodide (hereinafter referred to as the present quenching agent) and the present anti-fading agent, the present anti-fading agent may be added to a preformed porous ink-receiving layer, or A method of applying a solution in which the present anti-fading agent and the present quencher are dissolved in an appropriate solvent by a dipping method or a spray method is preferably adopted. It is also possible to employ a method in which the raw material for forming the porous ink receiving layer is mixed with the present anti-fading agent, or the present anti-fading agent and the present quencher are mixed in advance.

The content of the anti-fading agent is preferably 0.01 to 10% by weight based on the weight of the porous ink receiving layer. The content of the anti-fading agent is 0.01
If the amount is less than 10% by weight, the effect of the present invention is not sufficiently exhibited, and the ink may be discolored, which is not preferable. If the content of the present anti-fading agent exceeds 10% by weight, the absorptivity of the porous layer may be impaired, which is not preferable. The more preferable content of the present anti-fading agent is 0.1.
~ 1% by weight.

Although the present anti-fading agent is effective when used alone, the effect can be further enhanced by using it together with the present quencher. At this time, the total content of the present anti-fading agent and the present quencher is preferably 0.01 to 10% by weight based on the weight of the porous ink receiving layer. The total content of the present anti-fading agent and the present quencher 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. The total content of the anti-fading agent and the quencher is 1
When it exceeds 0% by weight, not only the coloring by the quencher itself becomes a problem but also the absorptivity of the porous layer may be hindered, which is not preferable. The total content of the present anti-fading agent and the present quencher is more preferably 0.1 to 1% by weight.
Is.

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 support the dye, and only a printed matter with 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, Ru configuration der in which the inorganic particles bonded by a binder. As the material of the inorganic particles,
Silica or alumina or hydrates thereof are preferred. Among these materials, pseudo-boehmite is particularly preferable. 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. Here, pseudo-boehmite is AlOO
It is an alumina hydrate represented by the composition formula of H, and the porous layer made of pseudo-boehmite is an aggregate having a pore structure.

When the porous ink receiving layer is made of pseudo-boehmite, the content of the present anti-fading agent or the total amount of the present anti-fading agent and the present quencher is 0.05 per 1 g of pseudo-boehmite. It is preferably about 50 mg. A more preferable range is 0.1 to 20 mg.

In the pseudo-boehmite porous ink receiving layer, the pore structure is substantially composed of pores having a radius of 1 to 10 nm, and the pore volume is 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. When the substrate is opaque, the recording sheet can be provided with necessary physical properties such as ink absorbency without impairing the texture of the substrate. 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 applying the pseudo-boehmite porous ink receiving layer on the substrate, a boehmite sol, preferably in the form of a slurry by adding a binder, using a roll coater, an air knife coater, a blade coater, a rod coater, a bar coater or the like. Apply on the base material,
A drying method can be preferably adopted.

As the binder used in the porous ink receiving layer, starch, its modified product, polyvinyl alcohol and its modified product, SBR (butadiene styrene rubber) latex, NBR (butadiene acrylonitrile rubber) latex, hydroxycellulose, polyvinylpyrrolidone, etc. The organic substances of are exemplified. 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. ~
Use 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.

[0023]

EXAMPLES Reference Example 1 A glass reactor having a capacity of 2 liters 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 75
Hydrolysis was carried out for 5 hours while maintaining at ~ 78 ° C. After that, the temperature was raised to 95 ° C., 9 g of acetic acid was added, and the mixture was added for 48 hours to
It was kept at ˜78 ° C. for peptization. 900g of this liquid
Concentration to give 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 treated with corona discharge treated polyethylene terephthalate (thickness 1
(00 μm) on a substrate using a bar coater so that the layer thickness when dried was 30 μm, and dried to form a pseudo-boehmite porous ink receiving layer.

The coated surface of the recording sheet obtained as described above was dipped in various concentrations of aqueous solutions or ethanol solutions of the treatment chemicals shown in Table 1 to uniformly apply the solution.
After hanging it vertically and air-drying it,
It was heated and baked at 0 ° C. for 4 minutes. In this reference example, a dithiocarbamate salt was used as a treatment agent.

A portion of the recording sheet thus obtained was cut out and immersed in an aqueous hydrochloric acid solution for 12 hours, and the solution was quantified by an ultraviolet-visible spectrophotometry or ion chromatography, and then recorded. The amount (carrying amount) of the treatment chemical consisting of the present anti-fading agent 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 reference example which had been subjected to the above-mentioned chemical treatment, the ink absorbability 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 Table 1. 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 Table 1 as "untreated".

[0029]

[Table 1]

In Table 1, the unit of the concentration of the treatment agent in the treatment liquid is a weight percentage, and the unit of the amount of the treatment agent carried in the recording sheet is mg per 1 g of pseudo-boehmite (AlOOH).
Is a number. The degree of fading is high (×), medium (△),
The degree of fading (small) is shown in three stages. The untreated sheet has a high degree of fading (x). The units of the concentration of the treatment liquid and the amount of the carried liquid and the evaluation criteria for the degree of fading are the same in Tables 2 and 3 below.

Reference Example 2 A recording sheet having a pseudo-boehmite porous ink receiving layer obtained in the same manner as in Reference Example 1 was treated with treatment liquids having various concentrations shown in Table 2 in the same manner as in Reference Example 1. Applied. Book
In the reference example, thiuram salt was used as a treatment agent. Table 2 shows the results of the same evaluations as in Reference Example 1. In addition, when recording was performed on the recording sheet of the present reference example using an inkjet printer, the ink absorbing property and the dye fixing property were excellent.

[0032]

[Table 2]

Example 1 A recording sheet having a pseudo-boehmite porous ink receiving layer obtained in the same manner as in Reference Example 1 was treated with treatment liquids having various concentrations shown in Table 3 in the same manner as in Reference Example 1. Applied. In the present embodiment, as a processing agent, thiocyanate diisocyanato
Lithium or potassium thiocyanate was used. Table 3 shows the results of the same evaluations as in Reference Example 1. In addition, when recording was performed on the recording sheet of this example using an inkjet printer, the ink absorbing property and the dye fixing property were excellent.

[0034]

[Table 3]

Reference Example 3 The coated paper obtained by coating the porous silica on the paper base material in the same manner as in Reference Example 1 was used to prepare various aqueous solutions or ethanol solutions of the treatment chemicals shown in Table 4. It was dipped and applied uniformly. This was hung vertically and air-dried, and then heated and baked at 140 ° C. for 4 minutes in a drum dryer. In this reference example, a dithiocarbamate salt was used as a treatment agent.

The silica-coated paper thus obtained was evaluated in the same manner as in Reference Example 1. The results are shown in Table 4. In Table 4, the unit of the concentration of the treatment agent in the treatment liquid is a weight percentage, and the unit of the amount of the treatment agent supported on the recording sheet is mg per 1 g of silica (SiO ₂ ). The degree of fading is high (×), medium (△), and low (○).
It was expressed in three stages. The untreated sheet has a high degree of fading (x). The units of the concentration of the treatment liquid and the supported amount and the evaluation criteria of the degree of fading are the same in Tables 5 and 6 below. In addition, when recording was performed on the silica-coated paper of this reference example using an inkjet printer, the ink absorbency and the dye fixability were excellent.

[0037]

[Table 4]

Reference Example 4 The silica-coated paper obtained in the same manner as in Reference Example 3 was coated with the treatment liquids having various concentrations shown in Table 5 in the same manner as in Reference Example 1. In this reference example, thiuram salt was used as a treatment agent. The silica-coated paper thus obtained was evaluated in the same manner as in Reference Example 3 . The results are shown in Table 5. The untreated silica-coated paper has a large degree of discoloration (x). In addition, the silica-coated paper of this reference example,
When recording was performed using an inkjet printer, the ink absorbency and the dye fixability were excellent.

[0039]

[Table 5]

Example 2 The silica-coated paper obtained in the same manner as in Reference Example 3 was coated with treatment liquids having various concentrations of treatment chemicals shown in Table 6 in the same manner as in Reference Example 1. In this example, sodium thiocyanate and potassium thiocyanate were used as treatment agents. The silica-coated paper thus obtained was evaluated in the same manner as in Reference Example 3 . The results are shown in Table 6.
The untreated silica-coated paper has a large degree of discoloration (x). In addition, when recording was performed on the silica-coated paper of this example using an inkjet printer, the ink absorbency and the dye fixability were excellent.

[0041]

[Table 6]

Example 3 The coated surface of a recording sheet having a pseudo-boehmite porous ink receiving layer obtained in the same manner as in Reference Example 1 was dipped in various aqueous solutions or ethanol solutions of the treatment chemicals shown in Table 7. , The solution was applied uniformly. This was hung vertically and air-dried, and then heated and baked at 140 ° C. for 4 minutes in a drum dryer. In the above Examples 1-2 and Reference Examples 1-4 ,
As a treatment agent, dithiocarbamate, thiuram salt,
Although only one compound of thiocyanates and thiocyanate was used, in this example,
As the treatment agent, a mixture of any one of dithiocarbamate, thiuram and sodium thiocyanate with a quencher consisting of sodium iodide or potassium iodide was used. The weight ratio of the quencher consisting of sodium iodide and potassium iodide to any one compound of dithiocarbamate, thiuram and sodium thiocyanate was 1: 2. The treatment liquid concentration is the total weight percentage of the mixture of the compound of any one of dithiocarbamate, thiuram and sodium thiocyanate and the quencher consisting of sodium iodide or potassium iodide.

Quenching comprising the compound of any one of dithiocarbamate, thiuram and sodium thiocyanate and sodium iodide or potassium iodide in the porous ink receiving layer of the recording sheet thus obtained. Quantification of total amount of mixture with agent and evaluation of fading degree
It carried out similarly to the reference example 1. The results are shown in Table 7. The unit of the carried amount and the evaluation standard of the degree of fading are the same as in Table 1.

Further, the coloring of the recording sheet was examined by allowing the sheet to stand in a room for 10 days and visually observing the coloring. The results are also shown in Table 7.

For comparison, the degree of fading and the coloring of the recording sheet were also examined by the same method for the recording sheet which was not treated with the chemicals. The results are shown in Table 7 as "untreated".

Further, as a treatment agent for comparison,
In the case of using only sodium iodide, which is a quencher, the degree of fading and the coloring of the recording sheet were examined by the same method. The results are also shown in Table 7.

[0047]

[0048]

[Table 7]

According to Table 7, a mixture of any one of dithiocarbamate, thiuram and sodium thiocyanate as a treating agent with a quencher consisting of sodium iodide or potassium iodide. In the case of this Example used, excellent anti-fading property, and further, sheet coloring was not observed, whereas when only sodium iodide, which is a quenching agent, was used as a treating agent, anti-fading property was not obtained. Although excellent, it can be seen that the recording sheet is colored.

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

Example 4 The coated surface of a recording sheet having a pseudo-boehmite porous ink receiving layer obtained in the same manner as in Reference Example 1 was dipped in aqueous solutions or ethanol solutions of various treatment chemicals shown in Table 8. , The solution was applied uniformly. This was hung vertically and air-dried, and then heated and baked at 140 ° C for 4 minutes in a drum dryer. In the above Examples 1-2 and Reference Examples 1-4 ,
As a treatment agent, dithiocarbamate, thiuram salt,
Although only one compound of thiocyanates and thiocyanate was used, in this example,
As the treatment agent, a mixture of thiuram salt and sodium thiocyanate or a mixture of sodium thiocyanate and a hindered amine compound was used. The weight ratio of thiuram salt to sodium thiocyanate was 1: 2, and the weight ratio of sodium thiocyanate to hindered amine compound was 2: 1. The treatment liquid concentration is a total weight percentage of a mixture of thiuram salt and sodium thiocyanate or a mixture of sodium thiocyanate and a hindered amine compound.

[0052] The recording sheet thus obtained porous ink-receiving layer, thiuram salt and thiocyanate isocyanatomethyl
A mixture of helium, or were performed as a mixture of sodium thiocyanate and hindered amine compound, the total amount of quantitative and evaluation of color fading level of Reference Example 1. The results are shown in Table 8. The unit of the carried amount and the evaluation standard of the degree of fading are the same as in Table 1.

For comparison, the degree of fading was also examined by the same method for the recording sheet which was not treated with the chemicals. The results are shown in Table 8 as "untreated".

Here, the TINUVIN 622LD is Ciba.
It is a product name of CIBA-GEIGY,
TINUVIN is a registered trademark of the same company.
This compound is a hindered amine-based compound, and is dimethyl-1- (2-hydroxyethyl) -4-dimethyl succinate.
Hydroxy-2,2,6,6-tetramethylpiperidine polycondensate. Chimasorb 944LD is a trade name of CIBA-GEIGY, and CHIMASSORB is a registered trademark of the company. This compound is a hindered amine-based compound, and is poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {2,2,2. It is represented by 6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}].

[0055]

[Table 8]

According to Table 8, excellent discoloration prevention is obtained not only when a mixture of thiuram salt and sodium thiocyanate is used as a treatment agent but also when a mixture of sodium thiocyanate and a hindered amine compound is used. It turns out that it shows sex.

When recording was performed on the recording sheet of this example using an ink jet printer, the ink absorbency and the dye fixing property were excellent.

[0058]

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.

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Claims (3)

(57) [Claims] On the 1. A substrate containing one or more compounds selected from the group consisting of sodium thiocyanate and potassium thiocyanate, 5-50% by weight relative to the inorganic particles and the inorganic particles An ink jet recording sheet having a porous ink receiving layer, which is bound with a binder. 2. The ink jet recording sheet according to claim 1, wherein the porous ink receiving layer further contains a quencher made of iodine or iodide. 3. The ink jet recording sheet according to claim 1, wherein the porous ink receiving layer has a structure in which pseudo-boehmite is bound with a binder.