JP2003205680A - Ink jet recording element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recording element having a fast ink drying time, having good stability when exposed to ozone and a high humidity condition and having high gross while minimizing cracking, and to provide a printing method using the ink jet recording element. <P>SOLUTION: In the ink jet recording element wherein an image receiving layer containing porous polymeric particles in a polymeric binder is formed on a support, the polymeric binder is polyvinyl alcohol having a hydrolysis ratio of at least 95% and a number average molecular weight of at least 45,000. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording element and a printing method using the element. More particularly, the invention relates to a porous ink jet recording element containing porous polymeric particles. 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 to produce an image on the medium. An ink droplet (or recording liquid) generally comprises a recording agent (eg, a dye or pigment) and a large amount of solvent. Solvents (or carrier liquids) are generally made from water and organic materials (eg, monohydric alcohols, polyhydric alcohols, or mixtures thereof). [0003] Ink jet recording elements generally comprise, on at least one surface, a support bearing an ink-receiving or image-forming layer, such elements comprising a reflective substrate having an opaque support. Included are those intended for expression observation and those intended for observation by transmitted light having a transparent support. [0004] Although a wide variety of different types of image recording elements have been proposed for use with ink jet devices, there are many open problems in the art and known products include: There are a number of deficiencies that have limited their commercial utility. It is well known that in order to achieve and maintain photographic quality images on such image recording elements, the ink jet recording elements must meet the following conditions. [0006] easily wet, padling
(I.e., no aggregation of adjacent ink dots leading to non-uniform density). No image bleeding. Absorbs high concentrations of ink and dries quickly to prevent the elements from blocking together when next printed or superimposed on another surface; Not exhibit any discontinuities or defects (eg cracks, repellents, combs, etc.) due to the interaction between the support and / or the layer (s); No unabsorbed dye agglomerates on the free surface, causing crystallization of the dye and causing blooming or ferroblowing (bronzing) effects in the image forming area. Have an optimized image fastness to prevent fading due to contact with water or irradiation by sunlight, tungsten lamps or fluorescent lamps; [0007] An ink jet recording element that simultaneously provides nearly instantaneous ink drying time and good image quality is desirable. However, it is difficult to simultaneously achieve these requirements of an ink jet recording medium because the ink composition and ink volume that the recording element needs to be compatible with is wide. [0008] Ink jet recording elements are known which employ a porous or non-porous single or multilayer coating which acts as a suitable image-receiving layer on one or both sides of a porous or non-porous support. Recording elements using non-porous coatings generally have good image quality, but exhibit poor ink drying time. Although recording elements using porous coatings exhibit excellent drying times, they generally have poorer image quality and are prone to cracking. [0009] A problem with known ink jet recording elements that employ a porous single or multilayer coating that acts as a suitable image receiving layer is the dye stability on storage. In particular, dyes printed on inkjet receiver elements have a propensity for fading due to exposure to ozone present in the atmosphere. [0010] Another problem with known ink jet recording elements that employ a porous single or multilayer coating that acts as a suitable image receiving layer is image stability under high humidity storage conditions. In particular, dye image-receiving layers are hydrophilic and have a tendency to absorb water from the atmosphere, so that dyes have a tendency to migrate through the image-receiving layer. [0011] Co-pending US patent application Ser. No. 09 / 608,466 (filed Jun. 30, 2000) relates to an ink jet recording element wherein the image receiving layer contains porous polymeric particles in a polymeric binder. However, this element causes aggregation of the polymer particles during the preparation of the coating solution,
There is a problem in that on application, an element with low gloss is produced. JP-A-9-207430, JP-A-8-324101 and JP-A-2000-203154 disclose a porous material for an ink jet recording element containing polyvinyl alcohol and inorganic particles having various hydrolysis rates. It relates to an image receiving layer.
However, there is a problem with these elements in that these references do not disclose the degree of hydrolysis of polyvinyl alcohol required to provide good gloss and low cracking. The following is prior art document information related to the invention of this application. [Patent Document 1] JP-A-8-324101 [Patent Document 2] JP-A-2000-203154 [Patent Document 3] JP-A-9-207430 [Problems to be Solved by the Invention] It is an object of the present invention to provide an ink jet recording element having a fast ink drying time. It is another object of the present invention to provide an ink jet recording element that has good stability when exposed to ozone and high humidity conditions. Another object of the present invention is to provide an inkjet recording element having high gloss while minimizing cracking. It is yet another object of the present invention to provide a printing method using the above-described ink jet recording element. SUMMARY OF THE INVENTION These and other objects are attained by an inkjet recording element comprising a support carrying an image receiving layer containing porous polymeric particles in a polymeric binder. Wherein said polymeric binder has a hydrolysis rate of at least 95% and at least 45,000
This is achieved by the present invention comprising an inkjet recording element comprising polyvinyl alcohol having a number average molecular weight of. DETAILED DESCRIPTION OF THE INVENTION The use of the present invention results in good drying time, good stability when exposed to ozone and high humidity conditions, and high gloss while minimizing cracking. An ink jet recording element is obtained. Another aspect of the present invention is: A) a step of preparing an ink jet printer responsive to a digital data signal; B) a step of loading said printer with said ink jet recording element; Loading the ink composition; and D) printing the inkjet recording element using the inkjet ink composition in response to the digital data signal. The support used in the ink jet recording element of the present invention may be opaque, translucent, or transparent. For example, various plastics such as plain paper, resin-coated paper, polyester resins (eg, polyethylene terephthalate, polyethylene naphthalate, and polyester diacetate), polycarbonate resins, fluorine resins (eg, polytetrafluoroethylene), metal foils, May be used. In a preferred embodiment, the support is a paper material or a voided plastic material. The thickness of the support used in the present invention can be 12 to 500 µm, preferably 75 to 300 µm. The porous polymer particles used in the present invention are in the form of porous beads, porous irregularly shaped particles, or aggregates of emulsion particles. Suitable porous polymer particles used in the present invention include, for example, acrylic resins, styrene resins, and cellulose derivatives (for example, cellulose acetate, cellulose acetate butyrate, cellulose propionate, cellulose acetate propionate, And ethyl cellulose), polyvinyl resins (e.g., polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate, and polyvinyl butyral, polyvinyl acetal, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer), and ethylene-allyl copolymer (e.g., Ethylene-allyl alcohol copolymer, ethylene-allyl acetone copolymer, ethylene-allyl benzene copolymer, ethylene-allyl ether copolymer), ethylene acrylic copolymer And polyoxymethylene,
And polycondensation polymers (eg, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyurethane, and polycarbonate). In a preferred embodiment of the present invention, the porous polymer particles are produced from a styrene monomer or an acrylic monomer. In producing such styrenic or acrylic polymers, any suitable ethylenically unsaturated monomer or mixture of monomers may be used. For example, styrene compounds (eg, styrene, vinyl toluene, p-chlorostyrene,
Vinylbenzyl chloride or vinylnaphthalene) or an acrylic compound (for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloroacryl) Methyl methacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate), and mixtures thereof. In another preferred embodiment, methyl methacrylate or ethylene glycol dimethacrylate is used. In a preferred embodiment of the present invention, the porous polymer particles are cross-linked. They can have a degree of crosslinking of 27 mol% or more, preferably 50 mol%, most preferably 100 mol%. The degree of crosslinking is determined by the mole% of the polyfunctional crosslinking monomer introduced into the porous polymer particles. Typical crosslinking monomers that may be used in the production of the porous polymer particles used in the present invention include aromatic divinyl compounds (eg, divinylbenzene, divinylnaphthalene, or derivatives thereof), and diethylene carboxylic acid. Acid esters and amides (eg,
Ethylene glycol dimethacrylate, diethylene glycol diacrylate), and other divinyl compounds (eg, divinyl sulfide or divinyl sulfone compounds). Divinylbenzene and ethylene glycol dimethacrylate are particularly preferred. The porous polymer particles used in the present invention contain an organic compound by, for example, pulverization and classification of a porous organic compound, emulsion polymerization, suspension polymerization, and dispersion polymerization of an organic monomer. Dissolving the organic material in a water-immiscible solvent by spray drying or dispersing the solution as fine droplets in an aqueous solution, and removing the solvent by evaporation or other suitable technique Can be prepared by a polymer suspension technique consisting of Bulk, emulsion, dispersion, and suspension polymerization procedures are well known to those skilled in the polymer art and are described in G. Odian's "P.
rinciples of Polymerization ", 2nd Ed., Wiley (1981)
And WP Sorenson and TW Campbell's "Prepara
tion Method of Polymer Chemistry ", 2nd Ed., Wiley
(1968). Techniques for synthesizing porous polymer particles are described, for example, in US Pat. Nos. 5,840,293;
Nos. 93,805, 5,403,870, and 5,599,889, and JP-A-5-222108 (1993). For example, an inert liquid or porogen may be mixed with the monomers used in making the porous polymer particles. At this point, after polymerization is complete, the resulting polymeric particles are substantially porous, as the polymer is formed around the porosifying agent, thereby forming a network of pores. This technique is more fully described in US Pat. No. 5,840,293, referenced above.
Thus, the porosity of the porous polymer particles is determined by mixing the monomer used to produce the porous polymer particles with a porogen, dispersing the resulting mixture in water, and To form the above-mentioned porous polymer particles. A preferred method for preparing the porous polymer particles used in the present invention includes droplets of the ethylenically unsaturated monomer containing the crosslinking monomer and the porogen in an aqueous medium. Forming a suspension or dispersion of the above, polymerizing the monomers to form solid porous polymeric particles, and optionally removing the porosifying agent by vacuum stripping. It is. The particles thus prepared are:
As measured by the specific surface area, 35m ² / g or more, preferably from 100 m ² / g or more porosity. This surface area is usually measured by BET nitrogen analysis known to those skilled in the art. The above-mentioned porous polymer particles are prepared according to US Pat.
88,598, 5,378,577, 5,563,226, and
It may be covered with a layer of colloidal inorganic particles as described in the specifications of US Pat. No. 5,750,378. Alternatively, the porous polymer particles may be covered with a layer of colloidal polymer latex particles as described in US Pat. No. 5,279,934. The porous polymeric particles used in the present invention have a median diameter of less than 10 μm, preferably less than 1 μm, most preferably less than 0.6 μm. The median diameter is defined as the statistical mean of the particle size distribution measured on a volume basis. For more details on measuring median diameter, see T. Allen, "ParticleSiz
e Measurement ", 4th Ed., Chapman and Hall (1990)
Please refer to. As described above, the polymer particles used in the present invention are porous. Porous means either particles with voids or particles that are liquid permeable. These particles may have either a smooth or a rough surface. The image receiving layer of the ink jet recording element of the present invention may contain a surfactant. Suitable surfactants include anionic or cationic surfactants. As mentioned above, the polyvinyl alcohol used in the present invention has a hydrolysis rate of at least 95% and a number average molecular weight of at least 45,000.
In a preferred embodiment of the present invention, the polyvinyl alcohol has a hydrolysis rate of at least 98%. In another preferred embodiment of the present invention, the polyvinyl alcohol has a number average molecular weight of 70,000 to 105,000. Commercial embodiments of such polyvinyl alcohols include Gohsenol ™ AH-22 from Nippon Gohsei,
Gohsenol ™ AH-26 and Gohsenol ™ AH-1
There are seven. The image receiving layer may be made of, for example,
It may contain additives such as a regulator, a crosslinking agent, a rheology regulator, a surfactant, an ultraviolet absorber, a biocide, a lubricant, a water-dispersible latex, a mordant, a dye, and a fluorescent brightener. The image-receiving layer can be applied to the substrate by conventional pre-metering or post-metering coating methods (eg, blade coating, air knife coating, rod coating, roll coating, slot die coating, curtain coating, slide coating, etc.). It can be applied to one or both surfaces. The choice of coating method will depend on the economics of operation, which will in turn determine the formulation specifications such as coating solids, coating viscosity, and coating speed. The image receiving layer has a thickness of 5 to 100 μm,
Preferably it can range from 10 to 50 µm. The required coating thickness is determined by the need for the coating to act as a reservoir to absorb the ink solvent. The image receiving layer of the present invention has a content of 0.2 to 10.0 g /
m ^2, preferably of the polymeric binder 0.40~ 5.0g / m ^2, and 1.5~60g / m ^2, preferably contain porous polymeric particles 3.0~30g / m ^2. [0036] 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 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 water-soluble direct dyes or acid dyes. Such liquid compositions are described, for example, in U.S. Pat.
It is described extensively in the prior art, including 81,946, 4,239,543 and 4,781,758. The following examples further illustrate the present invention. EXAMPLES The following elements having the described image-receiving layer were prepared. Element 1 of the Invention Borax (sodium tetraborate decahydrate) and sulfonated polyester dispersion AQ29 ™ (Eastman Chemical Co.)
And a coating surfactant Olin 10G ™ in a 10% by weight aqueous solution (the ratio of borax to polyester binder is
33:67) was applied by rod coating on a corona discharge treated resin-coated paper at a total dry laydown of 1.5 g / m ^{2 and} a dry laydown of borax of 0.5 g / m ²
And the dry laydown of the polyester binder is 1.0
g / m ² . The subbing layer coating was dried in a 40 ° C. oven for 20 minutes. An 18% by weight second solution comprising porous polymer particles (polyethylene glycol dimethacrylate) and a polyvinyl alcohol binder (AH-26 from Nippon Gohsei) (the ratio of porous polymer particles to PVA is 80:20) was applied over the above subbing layer by blade coating with a drying laydown of 40 g / m ² and dried at 40 ° C. for 20 minutes to provide an image receiving layer. The number average molecular weight of the polyvinyl alcohol listed in Table II was estimated from the viscosity of a 4% aqueous solution according to the table provided by the commercial manufacturer of polyvinyl alcohol. The hydrolysis rate of polyvinyl alcohol was obtained from the above manufacturer. Element 2 of the Invention This element was prepared the same as Element 1 except that the polyvinyl alcohol in the image receiving layer was AH-22 from Nippon Gohsei. Element 3 of the Invention This element was prepared the same as Element 1 except that the polyvinyl alcohol in the image receiving layer was AH-17 from Nippon Gohsei. Control element C-1 (low molecular weight PVA)
Ku, hydrolysis rate low) This element also has a polyvinyl alcohol in the image-receiving layer, except that it has a AL-06 manufactured by Nippon Gohsei, was prepared the same as Element 1. Control element C-2 (having a low hydrolysis rate)
Of) this element, the polyvinyl alcohol in the image-receiving layer, except that it has a Nippon Gohsei made of GH-23, was prepared the same as Element 1. Control element C-3 (having a low hydrolysis rate)
Of) this element, the polyvinyl alcohol in the image-receiving layer, except that it has a Nippon Gohsei made of GH-17, was prepared the same as Element 1. Control element C-4 (having a low hydrolysis rate)
Of) this element, the polyvinyl alcohol in the image-receiving layer, except that it has a Nippon Gohsei made KH-20, was prepared the same as Element 1. Control element C-5 (having a low hydrolysis rate)
Of) this element, the polyvinyl alcohol in the image-receiving layer, except that it has a Nippon Gohsei made KH-17, was prepared the same as Element 1. Tests Each element was imaged using an Epson 870 ink jet printer and ink jet ink (cartridge T007 (black) and cartridge T008 (color)) and then evaluated for cracks according to Table I. . [Table 1] Next, each element was measured for 60 ° gloss using a Gardner gloss meter. The average gloss and Dmin for cyan, magenta, yellow, red, blue, green and black were recorded in Table II. Average gloss greater than about 35 is acceptable. [Table 2] The above results show that any element according to the invention having a polyvinyl alcohol having a hydrolysis rate of at least 95% and a number average molecular weight of at least 45,000 provides better gloss compared to the control element. Is shown. Further, elements according to the present invention having a hydrolysis rate of at least 95% and a number average molecular weight of at least 70,000 provide both good gloss and fewer cracks as compared to the control element. Other preferred embodiments of the present invention are described below in connection with the claims. [1] An ink jet recording element comprising a support carrying an image receiving layer containing porous polymer particles in a polymer binder, wherein the polymer binder has at least 95% hydrolysis. An inkjet recording element comprising a polyvinyl alcohol having a ratio and a number average molecular weight of at least 45,000. [2] The element according to [1], wherein the porous polymer particles have a median diameter of less than 10 μm. [3] The element according to [1], wherein the porous polymer particles have a median diameter of less than 1 μm. [4] The element according to [1], wherein the porous polymer particles are crosslinked and have a degree of crosslinking of at least 27 mol%. [5] The porous polymer particles are produced from a styrene monomer or an acrylic monomer.
The element according to [1]. [6] The element according to [5], wherein the acrylic monomer comprises methyl methacrylate or ethylene glycol dimethacrylate. [7] The element according to [1], wherein the polyvinyl alcohol has a hydrolysis rate of at least 98%. [8] The element according to [1], wherein the support is a paper material or a voided plastic material. [9] The porosity of the porous polymer particles is determined by mixing the monomer used to produce the polymer particles with a porogen, dispersing the resulting mixture in water, and The element according to [1], which is achieved by polymerizing the monomer to form the porous polymer particles. [10] A) a step of preparing an ink jet printer responding to a digital data signal; B) a step of loading the ink jet recording element according to [1] into the printer; C) an ink jet ink composition in the printer. Loading an article; and D) printing on the inkjet recording element using the inkjet ink composition in response to the digital data signal.

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Claims (1)

Claims: 1. An ink jet recording element comprising a support carrying an image receiving layer containing porous polymer particles in a polymer binder, wherein the polymer binder comprises at least one polymer binder. Have a hydrolysis rate of 95% and at least
An ink jet recording element comprising polyvinyl alcohol having a number average molecular weight of 45,000.