JP2002248856A - Ink jet recording element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous ink jet recording element, which has a crack-free and favorable whole appearance, a drying time quicker tan that of other one and little ink agglutination. SOLUTION: The ink jet recording element ahs a support and a porous image accepting layer including particles, a polyvinyl alcohol binder and a crosslinker and providing on the support. The particles have primary particle diameters of 7 to 40 nm allowing an aggregate having the maximum diameter of 300 nm to be formed. The crosslinker is present by at least 20 mass% of the polyvinyl alcohol binder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a porous ink jet recording element and a printing method using the element.

[0002]

BACKGROUND OF THE INVENTION In a typical ink jet recording or printing system, ink droplets are ejected from nozzles at high speed toward a recording element or medium, producing an image on the medium. Ink droplets (or recording liquids) generally comprise a recording agent such as a dye or pigment and a large amount of solvent. The solvent (or carrier liquid) is generally made from water and organic materials (such as monohydric alcohols, polyhydric alcohols or mixtures thereof) and the like.

[0003] Ink jet recording elements generally comprise a support bearing on at least one surface thereof an ink-receiving layer or an image-receiving layer, which is intended to be viewed in reflection (opaque supports). Having) and those intended to be viewed by transmitted light (with transparent support)
Is included.

[0004] An important characteristic of an ink jet recording element is:
It is necessary to dry quickly after printing.
For this reason, porous recording elements have been developed that provide almost instantaneous drying as long as they have sufficient thickness and pore volume to contain the liquid ink efficiently. For example,
Porous recording elements can be produced by cast coating, in which a coating containing particulates is applied to a support and dried in contact with a polished smooth surface.

When manufacturing a porous recording element, it is difficult to optimize both the surface appearance of the image receiving layer and the ink drying time. Good image-receiving layer surface appearance is obtained when there are substantially no cracks. A crack-free surface appearance can be easily obtained by adding more binder to the image receiving layer. However, since the binder closes the holes in the image receiving layer, a large amount of the binder increases the drying time. Therefore, it is difficult to obtain an image receiving layer free from cracks and still drying at high speed.

[0006] Another problem with recording elements is ink agglomeration, which occurs when adjacent ink points agglomerate,
That is to produce a non-uniform density.

US Pat. No. 6,037,050 and EP-A-888,904 relate to ink jet recording elements in which the ink-absorbing layer comprises polyvinyl alcohol which is crosslinked with inorganic particles such as silica and a hardener. However, in these documents, the crosslinking agent is based on one binder.
There is no disclosure that it should be present in an amount greater than 0%.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a porous ink jet recording element which has a good overall appearance without cracks, has a drying time which is better than others, and has less ink agglomeration. is there. Another object of the present invention is to provide a printing method using the above elements.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording element having a support, and a porous image-receiving layer comprising particles, a polyvinyl alcohol binder and a cross-linking agent thereon, wherein the particles have a maximum particle size. This is achieved according to the invention in which the diameter which may agglomerate to 300 nm has a primary particle size of 7 to 40 nm and the crosslinking agent is an inkjet recording element present in an amount of at least 20% by weight of the polyvinyl alcohol binder.

The use of the present invention results in a porous ink jet recording element having a crack-free, high gloss, good overall appearance, having a drying time that is greater than others, and having less ink agglomeration.

[0011] Another aspect of the present invention is: A) providing an ink jet printer that responds to digital data signals; B) mounting the above ink jet recording element in the printer; Mounting on a printer, and D) printing on the image receiving layer using the inkjet ink composition in response to the digital signal.

[0012]

DETAILED DESCRIPTION OF THE INVENTION Examples of particles useful in the present invention include alumina, boehmite, clay, calcium carbonate, titanium dioxide, calcined clay, aluminosilicate, silica, barium sulfate, or polymer beads. These particles may be porous or non-porous. In a preferred embodiment of the present invention, the particles are metal oxides,
Preferably it is smoked (fumed). Although many types of inorganic and organic particles are produced by a wide variety of methods for image receiving layers and are commercially available, the porosity of the ink receiving layer is necessary to obtain very fast ink drying. is there. The pores formed between the particles must be large and interconnected enough so that the printing ink passes quickly through this layer and gives the impression of fast drying away from the outer surface. At the same time, the pores formed between the particles must be arranged so that they are small enough not to scatter visible light.

The particles can be in a primary form or in the form of secondary aggregated particles. This aggregate has a diameter of 7 to 40 nm
Up to 300 diameters
Aggregated to nm. The pores in the dry coating of such agglomerates fall within the range required to ensure low optical scattering and still sufficient ink wicking.

In the present invention, any smoke-treated metal oxide particles can be used. Examples of such particles include smoked alumina, silica, titania, cationic silica, antimony (III) oxide, chromium (III) oxide, iron oxide
(III), germanium (IV) oxide, vanadium (V) oxide, or tungsten (VI) oxide. Preferred examples of smoke treated metal oxides that can be used in the present invention include silica and alumina smoke treated oxides. The smoke-treated metal oxide is available in dry form or as a dispersion of the agglomerates described above.

[0015] Methods of smoke treating metal oxides are well known in the art. For example, Tec of Degussa AG., 1995
hnical Bulletin Pigments, No. 56, AEROSIL ™ Pr
Highly Dispersed Metallic O manufactured by ocess
You can refer to xides.

In the present invention, any polyvinyl alcohol can be used. In a preferred embodiment, these polyvinyl alcohols have an average viscosity greater than 20 cp when used in a 4% solid aqueous solution at 20 ° C. Specific examples of such polyvinyl alcohols that can be used in the present invention include:

[0017]

[Table 1]

The amount of polyvinyl alcohol binder used should be sufficient to provide cohesion to the image receiving layer, but the interconnected pore structure formed by the aggregates is not closed by the binder. Should be as small as possible. In a preferred embodiment of the present invention, the mass ratio of the binder to the total amount of the particles is 1:20.
１ ： 1: 5.

The image receiving layer can also contain a mordant. Examples of mordants that can be used include water-soluble cationic polymers, metal salts, water-insoluble cationic polymers in latex form, water-dispersible polymers, beads, or cationic, whether the core is organic or inorganic and the shell is in any case Polymeric core / shell particles are included. Such particles can be the product of addition or condensation polymerization, or a combination of both. They can be linear, branched, hyperbranched, grafted, random, block, and can have other polymer microstructures well known in the art. They may also be partially crosslinked. Core useful in the present invention /
Examples of shell particles are described in US patent application Ser.
2,097 specification (Title of Invention: Inkjet printing method, 2
Filed Jan. 26, 000, docket No. 81894HEC). Examples of water-dispersible particles useful in the present invention include Lawrence
No. 09 / 770,128 (Title of Invention:
Inkjet printing method, filed on January 26, 2000, Docket N
o. 81815HEC) and Lawrence et al.
No. 127 (Title of Invention: Inkjet printing method, 200
Docket No. 81817HEC, filed Jan. 26, 0).

Examples of the crosslinking agent that can be used in the present invention include carbodiimide, polyfunctional aziridine, aldehyde, isocyanate, epoxide, polyvalent metal cation, acetal, ketal and the like. In a preferred embodiment of the present invention, the crosslinking agent is an aldehyde, acetal or ketal. In a more preferred embodiment, the crosslinking agent is 2,3-dihydroxy-1,4-dioxane.

As mentioned above, the crosslinking agent is present in an amount of at least 20% by weight of the polyvinyl alcohol. This amount is far from the typical amount of crosslinking agent for polyvinyl alcohol. For example, Robert J. Kane's TAPPI PRESS, Atlanta G
a., 1995, page 96, PaperCoating Additives, describes the use of a typical aldehyde crosslinker, glyoxal, at 10% by weight, based on polyvinyl alcohol. In a preferred embodiment of the invention, the crosslinking agent is present at at least 40% by weight of the polyvinyl alcohol binder, more preferably at 50% by weight.

Since the image receiving layer is a porous layer containing particles, its void volume must be sufficient to absorb all the printing ink. For example, if the porous layer has 60% by volume pores, the image-receiving layer must have a physical thickness of at least 54 μm to immediately absorb 32 cc / m ² of ink.

The support of the ink jet recording element used in the present invention may be any of those conventionally used for ink jet receivers, such as resin coated paper, paper, polyester, or Teslin ™ (PPG Industries, Inc., Pittsburgh, USA). Tyvek ™ synthetic paper (DuPont Cor), a polyethylene polymer-containing material sold in Pennsylvania)
p.) and Oppalyte ™ film (Mobil Chemical
Co.) as well as other composite films and the like as described in US Pat. No. 5,244,861. Opaque supports include plain paper, coated paper, synthetic paper, photographic paper support, melt extrusion coated paper, and laminated paper (eg, biaxially oriented support laminates).
Biaxially stretched support laminates are disclosed in U.S. Pat.
Nos. 5,866,282, 5,874,205, 5,888,643, 5,888,681, 5,888,683, and 5,888,714. These biaxially stretched supports are
It includes a paper base and a biaxially oriented polyolefin sheet laminated to one or both sides of the paper base, typically polypropylene.

On the transparent support, glass, cellulose derivatives (eg, cellulose ester, cellulose triacetate,
Cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate), polyesters (eg, polyethylene terephthalate, polyethylene naphthalate, poly 1,4-cyclohexane dimethylene terephthalate, polybutylene terephthalate, and copolymers thereof), polyimide, polyamide, polycarbonate , Polystyrene, polyolefins (eg, polyethylene or polypropylene), polysulfones, polyacrylates, polyetherimides, and mixtures thereof. The above-mentioned paper includes a wide variety of papers from high-end paper (for example, photographic paper) to low-end paper (for example, newsprint).

The support used in the present invention has a thickness of 50 to 500 μm.
m, preferably 75 to 300 μm. If necessary, antioxidants, antistatics, plasticizers and other known additives may be incorporated into the support.
To improve the adhesion of the ink receiving layer to the support, the surface of the support may be subjected to a corona discharge treatment before the application of the image receiving layer.

The coating composition used in the present invention can be prepared by any of a number of well-known methods such as dip coating, wound wire rod coating, doctor blade coating, gravure coating and reverse roll coating, slide coating, bead coating, extrusion coating, curtain coating and the like. It can be applied by techniques. Known coating and drying methods are described in Research Disclosur
e), No. 308119, published December 1989, pp. 1007-1008. Slide coating is preferred,
The base layer and overcoat may be applied simultaneously.
After coating, this layer is generally dried by simple evaporation and can be facilitated by known techniques such as convection heating.

To improve colorant fade, UV absorbers, radical quenchers or antioxidants may be added to the image receiving layer, as is known in the art. Other additives include pH improvers, adhesion promoters, rheology improvers, surfactants, biocides, lubricants, dyes, optical brighteners, matting agents,
An antistatic agent and the like are included. In order to obtain sufficient coatability, additives well-known in such fields, for example, surfactants, defoamers, alcohols, and the like can be used. The usual amount of coating aid is 0.0% of the total solution weight.
It is an amount of active coating aid of 1 to 0.30%. These coating aids can be non-ionic, anionic, cationic or amphoteric. A specific example is MCCUTCHEON No. 1.
Volume "Emulsifiers and Dtergents", 1995, North American version.

The coating composition can be coated from water or an organic solvent, with water being preferred. The total solids content should be selected to produce a useful coating thickness in the most economical way. In specific coating formulations, the solids content is typically 10-40%.

[0029] Ink jet inks used to image the recording elements of the present invention are well known in the art. Generally, the ink composition used in inkjet printing is a liquid composition comprising a solvent or carrier liquid, a dye or pigment, a wetting agent, an organic solvent, a detergent, a thickener, a preservative, and the like. The solvent or carrier liquid can be pure water or can be water mixed with other water-miscible solvents such as polyhydric alcohols.
Further, an ink in which an organic material such as a polyhydric alcohol is a main carrier or a solvent liquid may be used. Particularly useful is a mixed solvent of water and a polyhydric alcohol. The dyes used in such compositions are generally
It is a water-soluble direct dye or acid dye. Such liquid compositions include, for example, U.S. Patent Nos. 4,381,946; 4,239,
Nos. 543 and 4,781,758 (which are incorporated herein by reference) are widely described in the prior art.

[0030]

EXAMPLE Element 1 of the present invention was coated with a fumed alumina (Cab-O-Sper
se ™ PG003, Cabot Corp.), PVA-B and the crosslinker 2,3-dihydroxy-1,4-dioxane (Clariant)
Corp.) in a ratio of 88: 10: 2 to give an aqueous coating formulation having a solids content of 30% by weight. As a result, the crosslinking agent is a polyvinyl alcohol binder 20
It is present in an amount of% by weight.

This layer was bead-coated at 40 ° C. on a polyethylene-coated paper base previously subjected to a corona discharge treatment. The coating was dried at 60 ° C. with forced air to obtain a recording element having a thickness of 40 μm.

Element 2 of the Invention The ratio of the composition is 87: 10: 3 to obtain an aqueous coating formulation with a solids content of 30% by weight, so that the crosslinking agent is 30% by weight of the polyvinyl alcohol binder. This element was prepared similarly to Element 1 except that it was present in the amount of

Element 3 of the Invention The ratio of the composition is 86: 10: 4 to give an aqueous coating formulation with a solids content of 30% by weight, so that the crosslinking agent is 40% by weight of the polyvinyl alcohol binder. This element was prepared similarly to Element 1 except that it was present in the amount of

Comparative element C-1 PVA-D was used in place of PVA-B, and the ratio of the composition was 8
Same as Element 1 except that an aqueous coating formulation having a ratio of 4: 15: 1 and 30% by weight solids was obtained, such that the crosslinker was present in an amount of 6.6% by weight of the polyvinyl alcohol binder. This element was prepared as follows.

Comparative Element C-2 PVA-D was used instead of PVA-B, and the ratio of the composition was 8
6.5: 12.5: 1 ratio, solid content 30% by mass
An aqueous coating formulation was prepared, similar to Element 1, except that the crosslinker was present in an amount of 8% by weight of the polyvinyl alcohol binder.

Comparative Element C-3 PVA-D was used in place of PVA-B, and the ratio of the composition was 8
An aqueous coating formulation having a ratio of 9: 10: 1 and 30% solids by weight was obtained, such that the crosslinker was present in an amount of 10% by weight of the polyvinyl alcohol binder, similar to Element 1 except that The element was prepared.

Coating Quality The dried coating was visually inspected for cracking defects as follows.

[Table 2]

The above results show that neither the recording element of the present invention nor the element of the comparative example has cracks.

Drying time Test images of cyan, magenta, yellow, red, green, blue and black bars (1.1 cm × 13.5 cm each) were cataloged on the above elements using an Epson Stylus ™ Photo870. Printing was performed with the ink of the number T008201. Immediately after being ejected from the printer, the bond paper was placed over the printed image and rolled with a smooth weight. Thereafter, the bond paper was separated from the printed image. If the recording element was not dry, the ink was transferred to the bond paper. The length of the bar imaged on the bond paper was measured.
The measured length of the bar imaged on the bond paper is proportional to the drying time. Drying times corresponding to about 40 cm or less are acceptable.

[0040]

[Table 3]

The above results show that the elements of the invention have much better drying times than the comparative elements.

Agglutination Test A test image of the green patch was taken from Epson Stylus ™ Photo 87.
Using 0, the element was printed with the ink of catalog number T008201. The patches were visually rated for ink agglomeration and rated as follows. 1 = none 2 = only 3 = medium 4 = terrible

The following results were obtained.

[Table 4]

The above results show that the recording elements of the present invention have much less aggregation than the comparative elements.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Lori Jeanie Shaw-Klein 14613, New York, USA 17F, Rochester, Riverside Street 17F term (reference) 2C056 FC06 2H086 BA15 BA31 BA33 BA35 BA45 BA46

Claims (1)

[Claims] 1. An ink jet recording element having a support and a porous image-receiving layer comprising particles, a polyvinyl alcohol binder and a cross-linking agent thereon, wherein said particles are capable of agglomerating up to 300 nm. Is 7 ~
A primary particle size of 40 nm and the crosslinking agent is at least 20% by weight of the polyvinyl alcohol binder
Inkjet recording element present in an amount of