JP2001047738A - Highly glossy ink jet recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording material jointly having a high glossiness and excellent drying characteristics by making the pigment a finely divided inorganic pigment of a specified particle size, and also, providing an internal pore capacity (volume) on the primary particle of the pigment, in an ink jet recording material including a supporting material and a pigment-containing ink-receiving layer. SOLUTION: In this ink jet recording material including a supporting material and a pigment-containing ink-receiving layer, the pigment is made a finely divided inorganic pigment of which the particle size is 0.01 to 1.0 μm, and also, an internal pore capacity (volume) is provided on the primary particle of the pigment. In this case, the internal pore capacity of the primary pigment particle is set to be approx. 0.1 to 3.0 cm3/g. Also, the average particle size of the finely divided inorganic pigment is set to be less than approx. 0.3 μm. In addition, the finely divided inorganic pigment is made silica. In the meantime, in the ink-receiving layer, polyvinyl alcohol is contained as a binder, and the saponification value is set to be approx. 75 to 98 mol%. Then, the ratio of the pigment to the binder in the ink-receiving layer is set within a range of approx. 10:1 to 1:1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a recording material having a high gloss and excellent ink drying properties for an ink jet printing method. Further, the present invention relates to a method for producing the ink jet recording material.

[0002]

BACKGROUND OF THE INVENTION In recent years, in connection with the overall development of electronic media, the importance of techniques for producing color prints has greatly increased. The goal of this technique is to adapt the image quality of color prints to the level of silver halide photography. One of the key technologies is ink jet printing, which has recently provided improved image quality. In the ink jet printing method, fine ink droplets are applied to a recording material. Ink jet recording materials used in this technology include:
Advanced requirements are required. As the request, for example,
High resolution, high color density of printed dots, fast ink absorption, good abrasion fastness, short ink drying time, no bleeding, no dye diffusion in the cross direction of printed dots, few spots ( Mottle), light fastness, and high water fastness, as well as dimensional stability. An even more important requirement for commercial applications is surface gloss. This is particularly important not only when preparing art graphics, but also when producing images that provide a photographic appearance.

The recording paper providing high gloss is, for example, resin-coated paper having a recording layer. DE19618
607A1 describes the use of polyolefin-coated paper to achieve high gloss. But,
Since the polyolefin layer acts as a barrier layer for the ink, the drying time is prolonged, and the ink cannot be absorbed by the supporting paper.

[0004] Drying due to the ink being dispersed in the hydrophilic polymer of the recording layer is very slow, so faster capillary ink absorption is required. This can be achieved by using pigments having a fine pore structure. For example, precipitated silica having a particle size of 5-10 μm and having sufficient pore volume to allow good ink absorption can be used. However, depending on the size of the pigment,
No gloss can be obtained.

[0005] Gloss can be achieved by using a finely divided pigment having a particle size smaller than the wavelength of visible light (for example, described in JP09323475). Among other pigments, such pigments include particle sizes of 10 to 3
0 nm colloidal silica. The surface of the pigment is modified cationically or anionicly to avoid the formation of larger secondary particles. According to the pigment,
It does not adversely affect the gloss, but instead reduces the absorption capacity of the recording material.

[0006] Known finely divided pigments include pyrogenic silica having an average particle size of about 6 nm.
These pigments, which are not surface modified and have no internal pore volume, have a strong tendency to form clumps having a size in the range of visible light wavelengths. Therefore, sufficient gloss cannot be achieved.

[0007] In addition, a recording material having a high gloss surface is obtained by cast-coating a recording layer on a support and treating the resulting product with a very smooth heated cylinder surface. Materials are known. The recording material is, for example, JP63-265680
Is disclosed.

[0008] EP 0810101 A1 describes a recording medium having a porous ink receiving layer containing alumina hydrate having a boehmite structure. The particle size of the alumina hydrate is in the range of 1 to 50 nm in the maximum length for needle-shaped particles or the maximum diameter for plate-shaped particles. The pore volume of the secondary particles of the alumina hydrate is preferably in the range of 0.1 to 1.0 cm ³ / g. The primary particles have no internal pore volume. This recording material will provide a high gloss.

JP 98-119417A includes a support,
A recording sheet having an ink permeable layer and an ink swelling layer for an ink jet printing method is disclosed. The ink permeation layer may be made of colloidal silica having a particle size of 10 to 200 nm. The silica can be modified to be cationic or anionic, and cationic colloidal silica is preferable in consideration of the movement of the ink after printing. The colloidal silica has no internal pore volume. The thickness of the ink permeable layer is 5 to 50 μm. This document describes that the goal is to overcome the difference in gloss between a print area and a non-print area of an image.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording material having both high gloss and excellent drying characteristics.

[0011]

SUMMARY OF THE INVENTION The object is to provide a support comprising a support and at least one ink-absorbing layer containing a highly colored finely divided inorganic pigment, wherein the primary particles of the pigment have an internal pore volume. ) Can be achieved by a recording material having:

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The pigment present in the recording layer is a finely divided inorganic pigment having a particle size of 0.01 to 1.0 .mu.m, particularly 0.02 to 0.5 .mu.m. Particularly preferred pigments have a particle size of 0.1.
It is a pigment of 1 to 0.3 μm. The pigment may be selected from the group consisting of elements belonging to Group IIa of the Periodic Table of the Elements and aluminum oxides, carbonates, silicates or sulfates. Preferred compounds include silica, aluminum oxide, barium sulfate, calcium carbonate, and magnesium silicate. The amount of the pigment in the recording layer can be from 50 to 90% by weight (based on the weight of the dried layer).

Particularly preferred is silica having a particle size of less than 0.3 μm, but aluminum oxide or a mixture of silica and aluminum oxide having an average particle size of less than 0.3 μm can also be used to advantage. According to another aspect of the present invention, a cation-modified silica having a particle size of 0.2 to 0.3 μm is used. The primary particles of the pigment used in the present invention are 0.1 to 0.1.
3.0 cm ³ / g, in particular having an internal pore volume of 0.5 to 1.5 cm ³ / g.

The binder used in the recording layer of the present invention is a hydrophilic colloid and / or a water-soluble binder such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, gelatin, starch, starch derivatives, casein, cellulose ester, alginate, and the like. It can be selected from the group consisting of polyethylene glycol, polyacrylic acid, or mixtures thereof. Particularly preferred as the binder in the recording layer is polyvinyl alcohol. Polyvinyl alcohol has a saponification value of 75 to 93 mol.
% Or completely saponified. Viscosity 35-100 cP, especially 50-75 c
It has been found that a high molecular weight polyvinyl alcohol of P is very preferred. The viscosity data is obtained based on an aqueous solution containing 4% by weight of polyvinyl alcohol,
Then, the measured value at 20 ° C. was recorded. The mass ratio of pigment to binder in the recording layer is about 1: 1 to 10:
1, especially 7: 1 to 9: 1.

The recording layer may further contain additives such as a crosslinking agent, a dispersant, a plasticizer, a fluorescent brightener, and a dye fixing agent. Dye fixatives include, for example, cationic agents such as quaternary polyammonium salts, cationic polyamines, cationic polyacrylamides, and cationic polyethylene imines. Particularly preferred are quaternary hydroxy-functional or amino-functional polyacrylates and addition products of the polyamine / epichlorohydrin resin or polyamidamine / epichlorohydrin resin systems. The amount of the dye fixing agent can be up to 5% by weight (based on the dried layer). If the amount of the dye fixing agent exceeds about 5% by weight, the gloss of the recording material may be adversely affected. The weight ratio of dye fixing polymer to binder in the ink recording layer can be from 1: 2 to 1:20, especially from 1: 4 to 1:10. The coating amount of the recording layer can be about 10 to 30 g / m ² , especially 15 to 25 g / m ² .

According to a preferred embodiment of the present invention, the recording material comprises a further layer, ie a cover layer applied on said ink recording layer. The cover layer is preferably a hydrophilic colloid and / or a water-soluble polymer such as gelatin, starch, starch derivative, casein, cellulose ester, alginate, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl acetate, polyethylene glycol, polyglycol. Acrylic acid or a mixture of the aforementioned binders can be mentioned.
Particularly preferred are polyvinyl alcohol and polyvinylpyrrolidone-homopolymer and / or polyvinylpyrrolidone-copolymer.

The binder content in the dry cover layer is 20
It can be from -90% by weight, preferably 40-90% by weight, most preferably 50-80% by weight (based on the dried layer). The cover layer may include further additives, for example, a crosslinking agent, a plasticizer, an optical brightener, and a dispersant. Further, the cover layer may include an inorganic oxide and / or a hydroxide. In particular, aluminum oxide, exothermic aluminum hydroxide, and aluminum oxide hydrate are suitable for this purpose. The mass ratio of inorganic oxide to binder is from 1: 1 to 1: 100, in particular 1: 1.
2-1: 50.

According to a further preferred embodiment, the cover layer further contains one or more cationic polymers which do not interfere with the pigment of the ink recording layer. In particular, quaternary hydroxy-functional or amino-functional acrylate homopolymers and / or acrylate copolymers are preferred. The amount of the cationic polymer in the cover layer is 1 to 3
It can be 0% by weight, in particular 5 to 20% by weight (based on the dried layer). The coating amount of the cover layer,
It is 0.1 to 3 g / m ² , especially 0.5 to ² g / m ² .

As the support material, any base paper can be used. Preferably, surface-size paper, calender paper or uncalendered paper, or high-size base paper can be used. The base paper can be sized with an acidic or neutral sizing agent. In particular, Tap
Paper having a surface roughness, determined according to pi 538 roughness, of less than 300 Sheffield units is preferred. The base paper will have high dimensional stability and will be able to absorb the moisture contained in the ink without curling. Highly dimensionally stable papers made from pulp mixtures including softwood sulphate fiber pulp and eucalyptus pulp are particularly suitable. D
E19602793B1 discloses a base paper for an ink jet recording material, so please refer to it for details.

In a particularly preferred embodiment of the present invention, the paper surface
In order for the open hole structure to exist,
Do not size to strength. 200 Sheffield roughness
Particular units of paper are particularly preferred. The basis weight of the base paper
Generally, 50-300 g / m ^TwoCan be Change
In a preferred embodiment, the back side of the support material is coated with a resin.
ing. Polyolefin or polyester
Can be used. Poly used for coating the base paper
The olefin is preferably low density polyethylene (LD)
PE) and / or high density polyethylene (HDPE)
You. The resin layer may include a pigment and another additive.
And its coating weight is 5 g / m^TwoAbove, more preferred
Or 20g / m^TwoIt is as follows. However, Barita
Coated and calendered base paper is also suitable for support
You.

For applying the layers on the support material according to the invention, any conventional coating and metering method can be used, such as roller coating, gravure or nip, air brushing, or bleed knife metering. A particularly preferred method is a method referred to as "wet-in-wet" in which both layers are applied by a cascade coater or a slot die coater. After the layer has been applied and after the layer has dried, the coated paper can be calendered to further increase smoothness. The following examples further illustrate the invention.

[0022]

【Example】

EXAMPLES 1-5 Essentially base paper, A layer coated on one side of the base paper, and B layer applied on the A layer (cover layer)
5 types of ink jet recording materials (Examples 1 to 5)
5) was produced. Hereinafter, the production of the inkjet recording material will be described in more detail.

The front side of the neutrally sized base paper is
Coated with low density polyethylene (LDPE). Covering body (mass) contained TiO ₂ to about 10 wt%.
The coating amount was 20 g / m ² . The back side of the base paper is L
A mixture of DPE and HDPE (high density polyethylene) was coated at a coverage of 20 g / m ² . The basis weight of the obtained base paper was 160 g / m ² . On the front side of the base paper, the coatings shown in Table 1 were applied to produce a layer A.
A second coating having the composition shown in Table 2 was applied on the wet A layer to produce a B layer. The coating amount of the dried layer B was 0.5 ± 0.2 g / m ² . The amounts given in each table mean% by weight based on the dry weight of the layer.

[0024]

[Table 1]

[0025]

[Table 2]

Thus, the following recording materials were produced.

[0027]

[Table 3]

[0028]

Comparative Example On a base paper having a polyethylene coating on both sides and a basis weight of 150 g / m ² , the ink receiving layer described in Table 4 was applied in an amount of 15 g / m ² . 10
After drying the ink receiving layer at a temperature of 4 ° C., the cover layer B2 of the above embodiment is placed on the ink receiving layer C1 or C2.
Was applied in an amount to give a dry coating weight of 2 g / m ² respectively. Subsequently, the cover layer was dried.

[0029]

[Table 4]

[0030]

[Test results] An ink jet printer "Epson 740" was applied to the recording papers manufactured in the above Examples and Comparative Examples.
At 720 dpi (dots per inch). The test print images were used to determine color density and drying time. Gloss is measured using unprinted material, D
r. Laboratory Reflectometer R manufactured by Lange
At L3, measured at an angle of 60 ° according to DIN 67530. Color density was measured for cyan, magenta, yellow, and black using an X-Rite densitometer type 428.

The drying behavior of the printing material was determined as follows. DIN A5 images were printed. Immediately after the printer finishes printing, remove the printed matter, and gently trace the image with your finger to make it dirty. The drying time was classified as less than 10 seconds (very good) or more than 10 seconds (insufficient) when no visible smear was observed in the image. The test results are summarized in Table 5.

[0032]

[Table 5]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor's Zyling 13212, NY, United States of America. Syracuse, Apartment 25E, Bear Road 5548 (72) Inventor Claus Bee. Kespar, Colorado, United States 80302-9375, Boulder, South Lake Ridge Trail 3048

Claims (21)

[Claims] 1. An ink jet recording material comprising a support material and a pigment-containing ink receiving layer, wherein the pigment is a finely divided inorganic pigment having a particle size of about 0.01 to 1.0 μm, and primary particles of the pigment. Wherein the ink jet recording material has an internal pore volume. 2. The ink jet recording material according to claim 1, wherein the primary pigment particles have an internal pore volume of about 0.1 to 3.0 cm ³ / g. 3. The ink jet recording material according to claim 1, wherein the finely divided inorganic pigment has an average particle size of less than about 0.3 μm. 4. The ink jet recording material according to claim 2, wherein the finely divided inorganic pigment has an average particle size of less than about 0.3 μm. 5. The ink jet recording material according to claim 1, wherein the finely divided inorganic pigment is silica. 6. The ink jet recording material according to claim 5, wherein the silica is a cation-modified silica. 7. The ink jet recording material according to claim 1, wherein the finely divided inorganic pigment is aluminum oxide. 8. The ink jet recording material according to claim 1, wherein the ink receiving layer contains polyvinyl alcohol as a binder. 9. The polyvinyl alcohol has a saponification value of:
The ink jet recording material according to claim 8, wherein the amount is about 75 to 98 mol%. 10. The ink jet recording material according to claim 8, wherein the polyvinyl alcohol is a completely hydrolyzed polyvinyl alcohol. 11. The ink jet recording material of claim 1, wherein the ratio of pigment to binder in the ink receiving layer is in the range of about 10: 1 to 1: 1. 12. The ink jet recording material according to claim 1, wherein the ink receiving layer contains a cationic dye fixing agent. 13. The ink jet recording material according to claim 1, wherein a cover layer is provided on the surface of the ink receiving layer. 14. The ink jet recording material according to claim 13, wherein the cover layer contains a hydrophilic colloid and / or a water-soluble polymer. 15. The ink jet recording material according to claim 14, wherein the polymer is a polyvinylpyrrolidone homopolymer and / or a polyvinylpyrrolidone copolymer. 16. The ink jet recording material according to claim 14, wherein the polymer is polyvinyl alcohol. 17. The ink jet recording material according to claim 13, wherein the cover layer contains aluminum oxide and / or aluminum hydroxide. 18. The coating amount of the cover coating is as follows:
Less than about 2 g / m ^2, the ink jet recording material according to claim 13. 19. The ink jet recording material according to claim 1, wherein the support material is uncoated base paper or resin-coated base paper. 20. The resin-coated paper is a base paper coated on one or both sides with a polyolefin resin.
2. The ink jet recording material according to item 1. 21. A pigment composition comprising a support, a pigment-containing ink receiving layer and a cover layer, wherein the pigment has a particle size of about 0.01 to 1.0 μm.
m of a finely divided inorganic pigment, and wherein the primary particles of the pigment have an internal pore volume, comprising: applying a pigment-containing ink receiving layer on the support material; The method of manufacturing, comprising applying the cover layer on the ink receiving layer by a wet coating method;