DE60304417T2 - Ink jet recording element and printing method - Google Patents

Description

The The present invention relates to a porous ink jet recording element with two types of polymer particles as well as a printing method below Use of the element.

In a typical inkjet recording or printing system ink droplets from a nozzle at high speed in the direction of a recording element or medium ejected, to create an image on the medium. The ink droplets or the recording liquid contains or contains generally a recording agent such as a dye or a pigment and a big one Amount of solvent. The solvent or the carrier liquid is typically made of water and an organic material, such as a monohydric alcohol, a polyhydric alcohol or mixtures prepared thereof.

One Ink jet recording element typically has one carrier on, on at least one surface, an ink-receiving layer or image-receiving layer, which includes those the for a reflection view is determined having an opaque carrier and those who are for one Viewing by means of transmitted Light are determined, which have a transparent support.

One essential characteristic for Inkjet recording elements is the need for after Printing to dry quickly. To date, porous recording elements have become developed, which lead to an almost immediate drying, as long as they have a sufficient thickness and a sufficient pore volume, to the liquid Effectively absorb ink. For example, a porous recording element be prepared by coating by casting, wherein a particle-containing coating applied to a support and dried in contact with a polished, smooth surface becomes.

Inkjet prints, manufactured by printing on inkjet recording elements are subject to degradation by environmental factors. They are particularly susceptible to damage, arising from contact with water and atmospheric Gases, such as ozone, gives. The damage after image production Made by contact with water, the shape of water can stain by removing the gloss of the topcoat occur due to a dye smear due to a undesirable Color diffusion and even by total release of the imaging layer. Ozone bleaches out inkjet dyes, resulting in a density loss leads. To avoid these disadvantages, inkjet prints often become laminated. However, lamination is costly as it is a separate roll of material required. A protection of the pressure can also be achieved by applying a polymer solution or dispersion on the surface an ink jet element after the image has been generated. The watery coating solutions are often polymer dispersions suitable for film formation are when the water is removed. Because of the great variety of surface properties However, it is difficult to get a watery polymer solution which is universally compatible with all inkjet receivers.

Alternatively, ink-jet recording elements having a two-layer structure such as those described in EP-A-1078775A2, in which US-A-5,756,755 is used JP 59222381 and in US-A-4832984. These elements typically comprise a porous ink-transporting overcoat of thermally fusible particles, resulting in either a swellable or porous ink-receiving layer. When printing, the ink passes through the cover layer into an ink-receiving layer. The cover layer is then sealed to give a print which is resistant to water and discoloration. Such overcoats, which thermally fusible particles typically either contain a binder or are thermally sintered together to provide a degree of mechanical integrity of the layer prior to the image recording and reflow stages.

The JP 256099694 describes an ink-jet recording element in which the image-recording layer contains a latex or wax particles of a diameter of 0.1 to 5.0 μm. While this recording element has a porous surface, the image-receiving layer has a very poor integrity and tends to detach from the support, resulting in image defects.

EPA-0858905 A1 describes the preparation of a recording medium having an outer porous layer by applying and drying a particulate thermoplastic resin at a temperature above its glass transition temperature (Tg) but below its minimum film formation temperature (MFFT). In the case of this element, however, there is a problem because the Trocknungstem temperature must be set very accurately to a temperature between the Tg temperature and the MFFT temperature in order to achieve the desired result.

The EP-A-0858906 relates to a carrier material, a porous ink receiving layer and a porous surface layer with good ink capacity. Desirable would it be however, if a good ink capacity could be achieved without Need to use a separate ink receptacle Layer.

It is an object of this invention, a novel, porous ink jet recording element which absorbs ink immediately and after image recording leads to a picture, that's a good quality and opposite Water and abrasion resistant. It is another subject of this Invention, a porous To provide inkjet recording element, which is easy to manufacture is.

One Another object of the invention is the provision of a printing method using the element described above.

These and other items be according to the invention provided comprising an ink jet recording element with a carrier, on which is a fusible, porous imaging layer with at least two types of hydrophobic polymer particles with different glass transition temperatures, wherein the first type of hydrophobic polymer particles has a Tg value from bigger than 60 ° C, which is essentially monodisperse and being the second type of hydrophobic polymer particles has a Tg of less than 25 ° C.

at Application of the invention is a porous ink jet recording element That is, it is printed with an inkjet ink, dry "immediately" against contact is that has a good picture quality and after the melting together a satisfactory resistance across from Abrasion and the action of water shows.

by virtue of the absence of light-diffusing material in the ink-receiving layer after fusing, the elements of the invention are suitable especially for transparent inkjet media and medical imaging media.

• A) Bereitstellung eines Tintenstrahl-Druckers, der auf digitale Datensignale anspricht;
• B) Beladung des Druckers mit dem Tintenstrahl-Aufzeichnungselement, wie oben beschrieben;
• C) Beladung des Druckers mit einer Tintenstrahl-Tinte; und
• D) Bedrucken der Bildempfangsschicht unter Verwendung der Tintenstrahl-Tinte entsprechend den digitalen Datensignalen.

Another embodiment of the invention relates to an ink jet printing process comprising the steps of:

• A) providing an inkjet printer responsive to digital data signals;
• B) loading the printer with the ink jet recording element as described above;
• C) loading the printer with an inkjet ink; and
• D) Printing the image-receiving layer using the ink-jet ink according to the digital data signals.

1a and 1b are sample prints of particle size data obtained by using an Ultrafine Particle Analyzer.

2 is an electron scanning micrograph of the comparison element C-1 which will be described later.

3 is an electron scanning micrograph of the comparison element C-2 which will be described later.

4 is an electron scanning micrograph of the element 1 of the invention, which will be described later.

5 is an electron scanning micrograph of the element 5 of the invention, which will be described later.

6 is an electron scanning micrograph of the element 11 of the invention, which will be described later.

The first type of hydrophobic polymer particles used in this invention, which is substantially monodisperse, can be prepared, for example, by emulsion polymerization of ethylenically unsaturated monomers with or without surfactants. Any suitable ethylenically unsaturated monomer or mixtures of monomers may be used to prepare the monodisperse polymer particles. For example, there may be used ethylene, propylene, 1-butene, butadiene, styrene, α-methylstyrene, vinyltoluene, t-butylstyol; monoethylenically unsaturated esters of fatty acids (such as vinyl acetate, allyl acetate, vinyl stearate, vinyl pivalate); monoethylenically unsaturated amides of fatty acids (such as N-vinylacetamide, N-vinylpyrrolidone); ethylenically unsaturated monocarboxylic or dicarboxylic acid esters (such as methyl acrylate, ethyl acrylate, propyl acrylate, 2-chloroethyl acrylate, 2-cyanoethyl acrylate, hydroxyethyl acrylate, methyl methacrylate, n-butyl methacrylate, benzyl acrylate, 2-ethylhexyl acrylate, cyclohexyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, isobornyl acrylate, isobornyl methacrylate, n-octyl acrylate, diethyl maleate, diethyl itaconate); Ethylenically unsaturated monocarboxylic acid amides (such as acrylamide, t-butylacrylamide, isobutylacrylamide, n-propylacryamide, dimethylacrylamide, methacrylamide, diacetoneacrylamide, acryloylmorpholine); and mixtures thereof. Up to 5% by weight, based on the total monomer mixture of water-soluble monomers, can be copolymerized to improve particle stability. Examples of preferred water-soluble comonomers are ethylenically unsaturated sulfonate or sulfate salts (such as sodium acrylamide 2-methylpropane sulfonate, sodium vinyl benzene sulfonate, potassium vinyl benzyl sulfonate, sodium vinyl sulfonate); monoethylenically unsaturated compounds (such as acrylonitrile, methacrylonitrile) and monoethylenically unsaturated carboxylic acids (such as acrylic acid, methacrylic acid, itaconic acid and maleic acid).

Tabelle 1

If desired, for the preparation of the monodisperse polymer particles, monomers having a UV absorbing moiety, a residue of an antioxidant, or a crosslinking moiety may be used to improve the light fastness of the image or other properties. Examples of UV-absorbing monomers that can be used include the following monomers:

Table 1

To typical crosslinking monomers used to prepare the monodisperse Polymer particles can be used which are within the scope of the invention are used aromatic divinyl compounds, such as divinylbenzene, divinylnaphthalene or derivatives thereof; Diethylene carboxylate esters and amides such as ethylene glycol dimethacrylate, Diethylene glycol diacrylate and other divinyl compounds such as divinyl sulfide or Divinyl sulfone compounds. Divinylbenzene and ethylene glycol dimethacrylate are especially preferred.

Examples for the Preparation of monodisperse polymer particles can be found in "Emulsion Polymerization and Emulsion Polymers ", P.A. Lovell and M.S. El-Aasser, John Wiley & Sons, Ltd., 1997, and in US-A-4,415,700.

The monodisperse polymer particles used in the invention are non-po Rös. By non-porous is meant a particle that is either pore-free or non-permeable to liquids. These particles can have either a smooth or a rough surface.

Of the second type of hydrophobic polymer with a Tg of less as 25 ° C, used in the present invention may be either a latex or a hydrophobic polymer of any composition, which can be stabilized in a water-based medium. Such hydrophobic Polymers are generally classified as either condensation polymers or addition polymers. For example, condensation polymers can be used belong Polyesters, polyamides, polyurethanes, polyureas, polyethers, polycarbonates, polyacid and polymers with combinations of the types mentioned above. addition polymers are polymers which are produced by polymerization of monomers from Vinyl type as above for the preparation of mono disperse polymer particles described. Polymers having monomers, the water insoluble homopolymers are preferably used, as are copolymers of such Monomers. Preferred polymers can also have monomers which lead to water-soluble homopolymers, when the total polymer composition is sufficiently water-insoluble, to form a latex. The watery Phase of the latex or colloidal dispersion of the invention water-soluble Have polymers, for example, the viscosity and the Flow characteristics to monitor. The watery Phase can also be surface-active Contain agents of cationic, anionic, zwitterionic or non-ionic types. Further lists of suitable monomers for Add-type polymers can be found in US Pat. No. 5,594,047.

in the Case of a preferred embodiment the invention is the Tg value of the polymer particle of the first Type at 60 ° C up to 140 ° C. In the case of another embodiment the Tg of the second hydrophobic polymer is at -60 ° C to 25 ° C. In the event of another preferred embodiment the monodisperse polymer particles having a Tg of 60 ° C to 140 ° C have a mean Particle size from 0.2 μm to 2 μm. The middle Particle size is defined as the size (or the diameter), which are 50 volume percent smaller than the particles as the size.

in the In another preferred embodiment, the monodisperse ones have Polymer particles a decade ratio less than 2, where the decade-ratio is an index of monodispersity and defines is as the relationship the particle size at the 90th percentile (percentile) of the particle size distribution curve to particle size in the 10th percentile. Percentile is defined as the given one Percentage of volume less than the specified size. In the event of another preferred embodiment is the wt .-% of monodisperse polymer particles with high Tg to the low Tg hydrophobic polymer at 10: 1 to 2.5: 1.

To the printing of the element used in the invention When the fusible, porous ink-receiving layer is heated and / or melted together by pressure to form a virtually continuous, to form transparent layer on the surface. After melting together (fusing), this layer is made non-light-scattering. The melting together can be effected in any way appropriate for the intended Purpose is suitable. A description of a fusion method using a fused band can be found in the US-A-5,258,256 and a description of a fusing method using a fuser roll is found in the US-A-4,913,991.

in the Case of a preferred embodiment the fusion is effected by contacting the surface of the Element with a heat-melting element, like a fuser roll or a fuser belt. For example, the melting together can be effected by feedthrough of the element through a pair of heated rollers, which on one Temperature of 60 ° C up to 160 ° C are heated under application of a pressure of 5 to 15 MPa a transport speed of 0.005 m / sec. up to 0.5 m / s ..

The Image receiving layer may further contain additives, such as pH modifiers, Rheology modifiers, surfactants, UV absorbers, Biocides, lubricants, waxes, dyes, optical brighteners, etc ..

The image-receiving layer may be applied to one or both substrate surfaces by conventional pre-measured or post-measured coating methods such as knife, air knife, rod, roll, slot, curtain and slide funnel methods, etc. The choice of coating process will be made determined by the economics of the process and in turn determined by the compositions such as the coating solids, the coating viscosity and the coating speed speed.

The thickness of the image recording layer before fusing may be 10 to 100 μm, preferably 20 to 70 μm. The coating thickness required is determined by the need for the coating to act as a sump for the absorption of ink solvent. In general, the image-receiving layer is applied in an amount of 10 g / m ² to 60 g / m ² . Further, the pore volume of the fusible, porous image-receiving layer is generally from 5 to 50 ml / m ² .

Of the Carrier, in the case of the ink jet recording element of the invention can be opaque, translucent or transparent. For example can simple papers are used, with resin coated papers, laminated paper as described in US-A-5,853,965; 5,866,282; 5,874,205; 5,888,643; 5,888,681; 5,888,683; and 5,888 714, various plastic materials, including polyester resins, such as poly (ethylene terephthalate), poly (ethylene naphthalate) and poly (ester diacetate), Cellulosic materials, such as cellulose acetate, cellulose diacetate and Cellulose triacetate, a polycarbonate resin, a fluororesin such as poly (tetrafluoroethylene), a metal foil, various glass materials and the like. The carrier may further consist of a voided polyolefin, polyester or a membrane. examples for the production of a pore-containing polyester can be found in US-A-5,354,601 and 6,379,780. A voided membrane can according to the known Technique of phase inversion. The thickness of the carrier, the used in the invention may be 12 to 500 microns, preferably at 75 to 300 microns.

If he wishes, can to the adhesion the porous one Particle layer of the invention to improve the carrier, the surface of the carrier a corona discharge treatment be exposed before the base layer or the solvents absorbing layer on the carrier is applied. Although the recording elements described herein described as being primarily suitable for ink-jet printers, can they used as recording media for pen plotter devices become. Pen plotters work by direct recording on the surface of the Recording medium by using a pen consisting of a bunch of capillary tubes in contact with an ink reservoir.

During the Ink printing process, ink droplets are rapidly in the porous coating absorbed by capillary action and the image is opposite one contact dry as soon as it comes out of the printer. As a result, allow porous Coatings quickly "drying" the ink and produce a across from a smear resistant image.

There the image recording element may come into contact with other image recording objects or the drive or transport mechanisms of the image recording devices, additives, like surface-active Agents, lubricants, matting particles and derglei chen the element be added in amounts that have the properties of interest do not dismantle.

The ink jet ink for recording in the case of the recording elements of the present Invention are well known in the art. The Ink compositions used in ink-jet printing are typically liquid Compositions with a solvent or a carrier liquid, Dyes or pigments, humectants, organic solvents, Detergents, thickeners, preservatives and the like. The solvent or the carrier liquid may consist of water alone or of water mixed with others water miscible solvents, such as polyhydric alcohols. Inks containing organic materials, like polyhydric alcohols the vast majority carrier or the vast majority Solvent liquid are, can also be used. Particularly suitable are mixed solvents from water and polyhydric alcohols. The dyes used in such Compositions used are typically water-soluble direct dyes or Acid-type dyes. Such liquid Compositions are detailed have been described in the art, including, for example, the US-A-4,381,946; 4,239,543 and 4,781,758.

The The following examples are intended to illustrate the invention in more detail.

EXAMPLES

example 1

Production of monodisperse polymer particles

particle of this invention were prepared according to one of the three below Method.

Method A: Preparation of anionic, monodisperse polymer particles in the presence of a surfactants through

One two liter reaction flask was charged with 753 g demineralized Water, 2.56 g aerosol MA-80 (Cytek Industries, Inc.) and one variable amount of sodium carbonate. The contents of the flask were opened Heated to 80 ° C. with stirring in a nitrogen atmosphere at 150 revolutions / minute. An addition flask with aqueous Phase was prepared with 649 g of demineralized water, 3.38 g Aerosol MA-80 and 3.78 g sodium persulfate. An addition flask for a monomer phase was prepared by adding 1011.4 g of ethyl methacrylate and 164.6 g of methyl methacrylate. Then 3.43 g of sodium persulfate in given the reaction flask. Within two minutes 498 became g of the aqueous Phase was added and 820 g of the monomer phase were added during a Added over a period of three hours. The reactor contents were then for two hours at 80 ° C heated to 20 ° C chilled was and what the reactor contents through a 200 micron Polycloth were filtered. The latex was purified by ultrafiltration Concentrated solids content of 50%. The size of the latex particles was controlled by the amount of monomer phase and by the amount of added sodium carbonate. The concentrations of surface-active Means and initiator were kept constant at 0.5 wt .-% and 0.7 wt .-%, based on the monomer. For example, was at a solids content of 40% of the reaction medium without sodium carbonate, the average particle size at 517.7 Nanometers and at a solids content of 50% with 7.84 g of sodium carbonate the mean particle size was 831.6 Nanometers. If particles of 800 nanometers were desired a staggered addition of the monomer phase required to monomer pooling to avoid as well as a strong exothermic reaction. To achieve this were 507 g of the aqueous Phase during 3.5 hours added. At the same time, 40 g of the monomer phase while the first 30 minutes, after which 940 g was added over the next three hours were.

Method B: Preparation of anionic, monodisperse polymer particles, free from surface-active medium

One 12 liter Morton reaction flasks were charged with 2000 g demineralized water. The contents of the flask were heated to 80 ° C with stirring under a nitrogen atmosphere with 150 revolutions / minute. A first addition flask with aqueous Phase was made with 1987 g of demineralized water and 13.2 g of sodium metabisulfite. A second addition flask with aqueous Phase was made with 1973 g of demineralized water and 26.4 sodium persulfate. A monomer phase addition flask was made by adding 2182 g of ethyl methacrylate and 364 g of methyl methacrylate. Then it was added to the reaction flask of each addition flask started at a rate of 5 g per minute. The addition pistons were refilled according to need. rehearse were taken at different times and the addition of the monomer phase was interrupted when the desired Latex particle size reached was. Additions of the redox initiator solutions were extended 30 minutes over the addition of the monomer phase to turn off residual monomers. The reactor flask contents were stirred at 80 ° C for one hour, whereupon to 20 ° C chilled and to which they were filtered through a 200 μm polycloth. The latex was purified by ultrafiltration to a solids content of 50% concentrated.

Method C: Preparation of cationic, monodisperse polymer particles, free from surface-active medium

A 12 liter Morton reaction flask was charged with 4000 g of demineralized water. The flask contents were heated to 80 ° C with stirring in a nitrogen atmosphere at 150 revolutions / minute. The addition flask with the initiator solution was prepared with 1974 g of demineralized water and 26.4 g of 2,2'-azobis (2-methylpropionamidine) dihydrochloride. A monomer phase addition flask was prepared by adding 2182 g of ethyl methacrylate and 364 g of methyl methacrylate. Then, the addition of the contents of each addition flask to the reactor flask was started at a rate of 5 g per minute. The addition flasks were replenished as needed. Samples became different The addition of the monomer phase was discontinued when the desired particle size of the latex had been reached. The additions of the redox initiator solutions were extended for 30 minutes beyond the end of the addition of the monomer phase to remove residual monomers. The reactor flask contents were stirred at 80 ° C for one hour, after which they were cooled to 20 ° C and filtered through a 200 μm polycloth. The latex was concentrated by ultrafiltration to a solids content of 50%.

Preparation of comparative polymer particles CP-1 (broad particle size distribution)

An organic composition was prepared by dissolving 47.9 g of cellulose acetate butyrate (Eastman Chemicals CAB 551-0.2) in 112.7 g of ethyl acetate at 68 ° C with stirring. An aqueous composition was prepared by dissolving 13.4 g of a 10% solution of Alkanol XC ^® (DuPont Corp.) in 361.3 g of water and heating to 68 ° C. The aqueous phase was added to the organic phase with low shear mixing and the combined phases were passed twice through a high shear Gaulin colloid mill to produce a particulate masterbatch. The resulting masterbatch was subjected to a rotary evaporator treatment to remove ethyl acetate, resulting in a cellulose acetate butyrate particle dispersion.

Preparation of comparative polymer particles CP-2 (broad particle size distribution)

CP-2 became similar as in the case of Process A, with the exception that the aqueous phase and the monomer phase were combined to pre-emulsify and that the phases in the reaction flask are from a single addition flask were added. The monomer emulsion was not stable, it occurred monomer pooling in the reactor and reaction heat output was not constant. Particle size distribution data, obtained by means of an Ultrafine Particle Analyzer, showed a bimodal particle size distribution at.

characterization of polymer particles

Glass transition temperature

Of the Tg of the dry polymer materials was determined by Differential Scanning Calorimetry (DSC) using a heating rate of 20 ° C / minute and the results are summarized in Table 2 below. Of the Tg value is defined here as the break point of the glass transition.

Particle size measurement

Polymer particles were characterized by an Ultrafine Particle Analyzer (UPA) manufactured by Leeds & Northrup. Two forms of graphical representation were obtained for the representation of the particle size data: the histogram (as in 1a shown) and the cumulative representation (as in 1b shown). Percentile points in 1b specify the given percentage of the volume that is less than the specified size. The 50% is used as the "average particle size". The decade-ratio is defined as the ratio of the particle size at the 90th percentile point to the particle size at the 10th percentile point. The smaller the decade ratio, the narrower the particle size distribution. Related to 1b for example, the 90th percentile point is 0.74 microns and the 10th percentile point is 0.31, so the decade ratio is 2.39 (0.74 divided by 0.31).

In Table 2 shows the production methods, the composition and the properties of the polymer particles used in the examples were summarized.

Table 2

• MM = methyl methacrylate
• EM = ethyl methacrylate
• EGD = ethylene glycol dimethacrylate
• SSDMEAA = sodium 2-sulfo-1,1-dimethylethylacrylamide
• AN = acrylonitrile
• UV-1 = refers to the structure on Table 1
• Particle dispersion B-1 with low T

B-1 is a polyurethane dispersion Witcobond W-320 ^® (CK Witco Corporation). The dispersion is non-ionic, therefore it is compatible with anionic or cationic polymer particle dispersions. The mean particle size of the dispersion was 3 μm and the Tg value was -12 ° C, both values reported by CK Witco Corporation.

Preparation of the comparison element C-1

A single layer porous ink jet medium was prepared by applying an aqueous solution containing particles CP-1 and B-1 to a polyethylene-coated paper which had been subjected to a corona discharge treatment prior to coating. The concentrations of CP-1 and B-1 were 36 and 7.2 wt%, respectively. 0.4% of a nonionic surface active agent Olin 10G ^® (Olin Corp.) was used in the coating solution thereto in order to control the surface tension during coating. The coating solution was deposited in an amount of 108.9 g / m ² (10 cc / ft ² ) and dried at 49 ° C for 3 minutes, followed by another 8 minutes at 25 ° C by circulating compressed air.

Preparation of the comparison element C-2

The Comparative element C-2 became similar as the element C-1 made with the exception that the polymer particle CP-2 was used.

Preparation of the comparison element C-3

Comparative Element C-3 was prepared similar to C-1 except that the coating solution contained 32% polymer particles P-7 and 3.2% Airvol ^® 205 polyvinyl alcohol (PVA) (Air Products Corp.).

Production of the elements 1-12 of the invention

The Elements 1-12 were similar prepared as C-1 except that the polymer particles P-2, P-3, P-4, P-6, P-7, P-9, P-10, P-11, P-12, P-14, P-15 and P-16 were.

Scanning electron microscopy (SEM)

One Piece of the Element was cut out and placed on a SEM stub with a Carbon belt attached. The surface The sample was mixed with platinum-palladium in a vacuum evaporator to produce a electrical conductivity Metal-coated. The sample was taken in an electron scanning microscope from Type Hitachi 5-4100 field emission gun scanning electron microscope (FEGSEM) examines using electron beam energy from 5 keV. On the sample, images were recorded at a tilt angle from 0 ° C and the representative Images of the coating were captured in a magnification area from 2000x to 50000x.

SEM images of comparison elements C-1 and C-2 and elements 1, 5 and 11 of this invention are shown in FIGS 2 - 6 shown.

Ink absorption

Inkjet samples came with an Epson Stylus Photo 820 printer a color ink cartridge T027 and a black ink cartridge T026 and they were used to print a pre-formed digital image used by color spots and images. The printed sample was immediately afterwards by means of a finger on strongly colored areas, as they were expelled from the printer, rubbed off. An "immediate Drying "means that the pressure at the touch was dry and that the picture by the finger abrasion reaction is not smeared or damaged has been. When the particles coalesced and a continuous Film when drying after coating provided, so supplied the ink droplets on the surface and did not penetrate through the layer.

As a result, such an image had a low optical density and easily smeared when worn ben.

merger

The printed samples was fused or fused together a set of heated, pressurized rollers, of which at least one was heated to a temperature of 150 ° C at a Speed of 2.5 cm per second.

Test for water and discoloration resistance

A solution of the dye Ponceau Red was prepared by dissolution of 1 g of the dye in 1000 g of a mixture of acetic acid and Water (5 parts: 95 parts). A Ponceau-Red dye solution of a Diameter of about 1 cm was applied to the sample surface Applied for 5 minutes. The liquid was then mixed with a Wipes paper towel of type Sturdi-Wipes paper towel wiped. It happened a visual observation of the tested area that recorded has been. No marking of dye staining left on the image, indicates the presence of a water-resistant topcoat; a red discoloration in the picture shows no presence of a water-resistant Topcoat on.

Picture quality

Gut

= kein Verschmieren

Mäßig

= geringes Verschmieren

Schlecht

= starkes Verschmieren

The elements were visually inspected and evaluated as follows:

Well

= no smearing

Moderate

= slight smearing

Bad

= heavy smearing

The Examination results of the comparison elements as well as the elements of the invention are summarized in Table 3 below.

Table 3

The The above results show that the ink jet recording elements the invention have improved ink absorption, a improved picture quality and an improved discoloration resistance compared to the comparison elements.

Example 2

In In this example, several types of ink jet elements have been used on a transparent, biaxially oriented poly (ethylene terephthalate) film support made, as in the case of medical imaging applications is used. Desirable is to achieve an image that has a slight veil after the Melting together to look at it in a transmission way to be able to.

Preparation of the comparison element C-4

This element consisted of a single porous ink-receiving layer consisting of fumed alumina (Cab-O-Sperse PG003 ^® (Cabot Corp.)), PVA (GH-23, (Nippon Ghosei)), 2,3-dihydroxy-1 , 4-dioxane (Clariant Corp.) and the dye mordant MM in a weight ratio of 82.5: 7.5: 3: 7 and having a thickness of 20 microns. MM was a cross-linked hydrogel polymer particle having an average particle size of 80 nm, made from 87% by weight of N-vinylbenzyl-N, N, N-trimethylammonium chloride and 13% by weight of divinylbenzene. 0.07% of a nonionic surfactant, Olin 10G ^® (Olin) was used in the coating solution to control the surface tension during coating.

Preparation of the comparison element C-5

This element was a simple ink-jet porous layer composed of PVA (Airvol 205 ^®), 5.9 .mu.m silica gel (23F (Crossfield)) and 2,3-dihydroxy-1,4-dioxane (Clariant Corp.) in a Weight ratio of 48.8: 48.8: 2.4 and with a thickness of 20 microns.

Production of the elements 13 to 26 according to this invention

These Elements were similar like the items 1 to 12 made with the exception that different Polymer particles were used and based on poly (ethylene terephthalate) Films were applied. That for Each particle used for each element is shown in Table 4 below listed.

Ink absorption and merger

These Elements were printed and fused as described in Example 1. A previously compiled digital image with a medical Black and white x-ray image and gray scales was used for printing.

Movie appearance after the merger

Gut

= klar oder transparent

Schlecht

= schleierig

The elements were checked after fusing and rated as follows:

Well

= clear or transparent

Bad

= hazy

The following results were obtained: Table 4

The above results show that the commonly used layer compositions for ink-jet elements such as Comparative Elements C-4 and C-5 are not suitable for medical imaging applications because of their strong light-scattering properties. Elements 13-26 according to the invention provide transparent images in addition to fast ink absorption and satisfactory image quality, and are therefore particularly suitable for medical inkjet imaging applications.

The element 13 was further examined for the pore volume in the ink-receiving layer. The study was conducted using the Mercury Intrusion Porosimetry, Model 9520 from Micromeritics Instrument Corporation. The volume of mercury entering the pores as a function of the applied hydraulic pressure on the mercury / sample combination was measured. When the amount of mercury had entered, the amount of pore volume was measured by changing the electric capacity, since the mercury column over the mercury / sample mass decreases as the mercury enters the sample. In the case of element 13, a pore volume of 19.5 ml / m ^{2 was} measured.

Example 3

in the In the case of this example, two pigment-based ink sets were applied to the Element 3 of the invention printed and dry and fuse left as described in Example 1. The two sentences of Pigment inks differed in the average particle size of the pigment dispersions, measured by UPA for a particle size measurement, as described in Example 1. Epson inks, used for the Epson C80 printer, filled in Epson ink cartridges T0322 (blue-green), T0323 (purple) and T0324 (yellow) and three additional ones Pigmented inks made by the inventors after similar Methods as described in US-A-5,679,138; 5 670 139; 6,152,999 and 6,210,474, were used for printing. The particle sizes of Pigments used in these inks are in Table 5 listed.

Table 5

Gut

= Bild war unbeschädigt

Schlecht

= Bild wurde abgerieben mit Kratzlinien auf der Oberfläche.

After fusing, the prints were checked for abrasion resistance at the inked areas by rubbing the samples with a dry paper towel 8 times under a pressure of 200 g over an area of 3.5 cm in diameter. The elements were examined and rated as follows:

Well

= Picture was undamaged

Bad

= Image was rubbed off with scratches on the surface.

The following results were obtained: Table 6

The The above results show that the pigments have a medium Particle size of 90 nm or larger, imprinted to the element 3 of this invention, a poor abrasion resistance exhibited.

From Cross sections were made and further investigated for these prints to the dye position through optical microscopy. It turned out that the pigments used in the Inks 1 and 2 were used, remained on the surface of the element 3 and that the pigments used in inks 3 to 6 penetrated into the ink-receiving layer. This indicates that the average particle size of the pigments, which are used in the inks, preferably less than 90 nm is to provide satisfactory abrasion resistance in the image areas to create.

Claims (10)

Ink jet recording element with a support, on which is a fusible, porous imaging layer contains at least two types of hydrophobic polymer particles with different glass transition temperatures, wherein the first type of hydrophobic polymer particles has a Tg value from bigger than 60 ° C, which is substantially monodisperse and wherein the second type is hydrophobic Polymer particles has a Tg of less than 25 ° C. The element of claim 1, wherein the first type of hydrophobic polymer particles that are substantially monodisperse, has an average particle size, which is defined as the size of such that 50% by volume of the particles are less than 0.2 microns to 2 microns, wherein this type a particle size distribution has that relationship the particle size at the 90% proportion of the particle size distribution curve to the particle size in the 10% -part of the particle size distribution curve is less than 2. The element of claim 1, wherein the first type hydrophobic polymer particles that are substantially monodisperse, a Tg value of 60 ° C up to 140 ° C Has. The element of claim 1, wherein the second type is hydrophobic polymer particles has a Tg of -60 ° C to 25 ° C. The element of claim 1, wherein the weight ratio of the first type of hydrophobic polymer particles to the second type of hydrophobic polymer particles at 10: 1 to 2.5: 1. The element of claim 1, wherein the porous imaging layer is coated in an amount of from 10 g / m ² to 60 g / m ² . An element according to claim 1, in which the carrier is a resin-coated paper or a transparent polymer film. The element of claim 1, wherein the porous imaging layer is cross-linked. The element of claim 1 wherein the porous imaging layer deposits ultraviolet radiation contains sorbent. Ink jet printing process with the steps: A) the provision of an inkjet printer based on digital Responds to data signals; B) the loading of the printer with the An ink jet recording element according to claim 1; C) the loading the printer with an ink-jet ink; and D) the printing the image-receiving layer using the ink-jet ink accordingly the digital data signals.