JP3236118B2 - Record sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates, about the recording sheet.

[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,
No sufficient absorption and resolution can be obtained and does not be transparent can be obtained, for example, as such JP 2-276670, serial Rokushi over bets to form a porous layer of an inorganic based material Has been proposed.

[0003]

As described above [0005], a good ink absorbency, and, in the serial Rokushi over preparative having good porous layer of the fixing of the dye, resin during storage In some cases, even such a plasticizer as described above was adsorbed, causing discoloration. SUMMARY OF THE INVENTION An object of the present invention is to provide a recording sheet which has good ink absorbability and good dye fixability, and has no discoloration even after long-term storage.

[0004]

According to the present invention , there is provided a recording sheet having a porous ink-receiving layer containing a chain polyvalent carboxylic acid (excluding a polymer) on a base material , wherein
The receiving layer contains inorganic particles in an amount of 5 to 50 wt.
% Recording sheet
You . In addition, the present invention provides a method for producing a chain having 10 or less carbon atoms on a substrate.
Having a porous ink receiving layer containing a polycarboxylic acid of the formula
Recording sheet, wherein the ink receiving layer comprises inorganic particles
With a binder of 5 to 50% by weight based on the inorganic particles.
Ru recording sheet der a combined configuration.

[0005] In the present invention, the chain polycarboxylic acid is an organic acid selected from the group consisting of acids in which two or more hydrogens of a chain hydrocarbon are substituted with carboxyl groups and oxalic acid. However, polymers are excluded. Specific examples include malonic acid, succinic acid, adipic acid, maleic acid, and oxalic acid. This polycarboxylic acid may be partially or wholly anhydride. Further, as long as it shows acidic properties as a whole, it may further contain a substituent such as a hydroxyl group or an amino group such as citric acid or aspartic acid. The chain polyvalent carboxylic acid preferably has 10 or less carbon atoms including carbon atoms of the carboxyl group. If the number of carbon atoms exceeds 10, handling may be difficult due to a decrease in solubility in various solvents and the like, which is not preferable.

The linear polycarboxylic acid may be present in the form of a salt. As the salt, a salt in which an aqueous solution is acidic is preferable, and examples of such a salt include salts in which a part of hydrogen of a carboxyl group of a polycarboxylic acid is substituted with another cation. The cation at this time is preferably an alkali metal ion or an ammonium ion.

[0007] As a method for imparting a chain polycarboxylic acid to the porous ink receiving layer, a solution prepared by dissolving a chain polycarboxylic acid in an appropriate solvent is dipped in a porous ink receiving layer formed in advance or by a dipping method. A method of applying by a spray method or the like is preferably employed. Alternatively, a method in which a chain type polycarboxylic acid is mixed with a raw material for forming the porous ink receiving layer can be adopted. For porous ink receiving layer
In the method of applying the solution, the solvent can be appropriately selected according to the solubility of the chain polycarboxylic acid.
When the chain polycarboxylic acid is used in the form of a salt, the use of water as a solvent has an advantage that the application of the solution is facilitated.

The content of the chain type polycarboxylic acid is 0.05 to 7.5 based on the weight of the porous ink receiving layer.
% By weight. When the content of chain polycarboxylic acid is less than 0.05% by weight, the onset light effect is not sufficiently expressed, since discoloration of the recording sheet is likely to occur undesirably. When the content of the chain polycarboxylic acid exceeds 7.5% by weight, not only the effect of suppressing discoloration does not increase any more, but also the absorption of the porous ink receiving layer may be inhibited, which is not preferable. . The more preferred content of the chain polycarboxylic acid is 0.5 to 5.5% by weight.

In the present invention, the porous ink receiving layer comprises:
A porous layer capable of absorbing and fixing ink during recording.
If the thickness of the porous ink receiving layer is too thin, the dye cannot be sufficiently supported, and there is a possibility that only a printed matter having a low color density may be obtained, which is not preferable.If the thickness is too large, the strength of the porous ink receiving layer is reduced or , transparency of printed material transparency is reduced
Or it is not preferable because there is to Ruosore or impaired texture. The preferred thickness of the porous ink receiving layer is 1 to 5
0 μm.

[0010] The porous ink-receiving layer may include compositions that combine the inorganic particles in Bas-in <br/> loaders are preferred. The material of the inorganic particles, alumina, silica or their hydrates are preferred. When a pseudo-boehmite porous layer is used as the porous ink receiving layer, it has good absorbability and selectively adsorbs the dye well.
This is particularly preferable because a clear recorded matter having a high color density can be obtained. Pseudo-boehmite is an alumina hydrate represented by the composition formula of AlOOH, and is an aggregate having a pore structure.

The pseudo-boehmite porous layer has a pore structure substantially composed of pores having a radius of 10 to 100 °, and when the pore volume is 0.3 to 1.0 cc / g, sufficient absorption is obtained. It is preferable because it has transparency and transparency. At this time, if the substrate is transparent, one serial Rokushi over preparative also clear is obtained. If the substrate is opaque, Ru can be given the properties that are required without impairing the texture of the substrate. In addition to these physical properties, it is more preferable that the pseudo-boehmite porous layer has an average pore radius of 30 to 70 °. The pore size distribution is measured by a nitrogen adsorption / desorption method.

In order to produce a pseudo-boehmite porous layer having the above-mentioned pore structure, it is preferable to use a boehmite sol obtained by hydrolyzing an alkoxide of aluminum. Means for coating on the substrate, the boehmite sol, preferably by adding a binder to form a slurry, roll-coated, air knife coater, blade coater, rod coater, coated on the substrate using a bar coater, etc., and dried it is possible to adopt the method.

In the present invention, as the binder of the inorganic particles, organic substances such as starch and modified products thereof, polyvinyl alcohol and modified products thereof, SBR latex, NBR latex, hydroxycellulose and 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, and if it is too large, the amount of ink absorbed or the amount of the dye carried in the porous ink receiving layer may be reduced, About 5 to 50% by weight of the inorganic particles is required .

In the present invention, various substrates can be used. For example, polyester such as polyethylene terephthalate, polycarbonate, ETF
Plastic fluorine resin such as E, or can use the paper. Further, for the purpose of improving the adhesive strength of the porous ink receiving layer, a corona discharge treatment, an undercoat, or the like can be performed.

[0015]

Although the action of the chain polycarboxylic acid in the present invention is not clearly understood, it is adsorbed on the porous ink receiving layer and interacts with a component such as a plasticizer of plastic which causes color development. It is thought that these adsorption or coloring are suppressed.

[0016]

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 until the liquid temperature reached 75 ° C. by a mantle heater. While stirring, 306 g of aluminum isopropoxide was added,
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 mixture was peptized by keeping the temperature at 75 to 78 ° C. for 48 hours. The solution was further concentrated to 900 g to obtain a white sol.
The dried product of this sol was pseudo-boehmite.

[0017] In addition to polyvinyl sulfonyl A <br/> 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 applied to a corona discharge-treated polyethylene terephthalate (thickness: 100 μm) substrate using a bar coater so that the layer thickness when dried was 30 μm, and dried to form a pseudo boehmite porous material. A quality ink receiving layer was formed.

The surface of the porous ink receiving layer of the recording sheet obtained as described above was placed in an ethanol solution or an aqueous solution having a concentration of 0.2 mol / liter of a linear polycarboxylic acid or a salt thereof shown in Table 1. It was immersed and the solution was uniformly applied.
This was suspended vertically and air-dried.
It baked by heating at 0 degreeC for 4 minutes.

The recording sheet thus obtained ( hereinafter referred to as the recording sheet )
Lower, and processing of sheet), a recording sheet (hereinafter is not performed processing <br/> management in chain polycarboxylic acids, that untreated sheets)
, A polyvinyl chloride film of the same size was superimposed on each coated surface, and kept for 14 days in a room for comparison . In the untreated sheet, yellow coloring was observed at the end, but no such coloring was observed in any of the treated sheets.

[0020]

[Table 1]

Example 2 A coated paper obtained by coating porous silica on a paper substrate was coated on the coated surface of the coated paper in the same manner as in Example 1.
Solution of 0.2 mol / liter of chain polycarboxylic acids by immersing the shown, was coated evenly solution. This was suspended vertically and air-dried, and then heated and baked at 140 ° C. for 4 minutes in a drum dryer.

[0022] and the processing sheet obtained in this way, no
The processing sheet, overlapping polyvinyl chloride film of the same size in each of the coated surface, the ratio was held indoors 14 days
Compared . In the untreated sheet, yellow coloring was observed at the end, but no such coloring was observed in any of the treated sheets.

[0023]

The recording sheet of the present invention has good ink absorbability and good dye fixability. Moreover,
No discoloration occurs even after long-term storage. Although the recording sheet of the present invention is effective for various recording methods, it is particularly suitable as a recording medium for an ink jet printer.

Continuation of the front page (56) References JP-A-58-136478 (JP, A) JP-A-5-124330 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5 / 00

Claims (3)

(57) [Claims] 1. A recording sheet having a porous ink receiving layer containing a chain polyvalent carboxylic acid (excluding a polymer) on a substrate , wherein the ink receiving layer comprises inorganic particles,
Structure bonded with 5 to 50% by weight of a binder based on particles
The record sheet that is the result . 2. A recording sheet having a porous ink receiving layer containing a chain polycarboxylic acid having 10 or less carbon atoms on a substrate , wherein the ink receiving layer comprises inorganic particles,
Structure bonded with 5 to 50% by weight of a binder based on particles
The record sheet that is the result . 3. The recording sheet according to claim 1, wherein the porous ink receiving layer is pseudo-boehmite.