JPS61154988A - Recording material - Google Patents

Abstract

PURPOSE:To provide a recording material for ink jet recording especially excellent in aqueous ink receptivity and sharpness of a recording image, by forming an ink holding layer from an aqueous ink absorbable hydrophilic resin and constituting an ink pervious layer from a layer with a specific thickness comprising a water resistance polyurethane resin. CONSTITUTION:An ink pervious layer with a thickness of 0.01-0.1mum comprising a polyurethane resin is provided on an ink holding layer and a powder layer is further pref. provided to said ink pervious layer. The polyurethane resin material useful for forming said thin layer is an adduct polymer of a polyisocyanate compound and a compound having two or more of active hydrogen atoms, for example, polyol, polyamine or polycarboxylic acid. The above mentioned recording material is extremely improved in ink receptivity, long-term stability and characteristics at a printing time and has the OHP fittability of a printing diameter and is free from the white turbidity of a printed part and imparts a projection image with uniform density.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a recording material suitably used in an inkjet recording method, and particularly relates to ink receptivity, clarity of recorded images, transportability in a printer, and blocking resistance. When the recording material is a translucent recording material,
The present invention relates to a recording material that has excellent ink receptivity and translucency.

(Prior Art) Inkjet recording methods include various ink (recording liquid) ejection methods, such as an electrostatic suction method, a method that applies mechanical vibration or displacement to the recording liquid using a piezoelectric element, and a method that applies mechanical vibration or displacement to the recording liquid using a piezoelectric element. In this method, small droplets of ink are generated and made to fly by foaming and using the pressure of the foam, and some or all of these droplets adhere to a recording material such as paper to perform recording, but this method generates noise. It is attracting attention as a recording method that can perform high-speed printing and multicolor printing.

Inks for inkjet recording are mainly water-based in terms of safety and recording properties.
Polyhydric alcohols and the like are often added to prevent nozzle clogging and improve ejection characteristics.

The recording material used in this inkjet recording method has conventionally been a recording material consisting of a base material called ordinary paper or inkjet recording paper on which a porous ink receiving layer is provided. However, as the performance of inkjet recording apparatuses improves and becomes more widespread, such as faster recording speeds and multicolor recording, more advanced and wide-ranging properties are being required of recording materials. In other words, as a recording material for inkjet recording to obtain high-resolution, high-quality recorded images, (1) it must be able to accept ink as quickly as possible; (2)
Even if ink dots overlap, the ink deposited later does not flow into the dots deposited earlier; (3) the ink spreads appropriately and the ink dots become the desired size; (4) The shape of the ink dot is close to a perfect circle, and its circumference is smooth. (5) The OD (optical density) of the ink dot is high.

Doy) The surrounding area should not be blurred, It is necessary to satisfy basic requirements such as:

Furthermore, in order to obtain high-resolution recorded image quality comparable to color photography using a multicolor inkjet recording method, in addition to the above-mentioned required performance, (6) the coloring components of the ink must have excellent color development; 7) The ink receptivity is particularly excellent, as the same number of droplets as the number of ink colors may adhere to the same spot, (8) The surface is glossy, (9) Whiteness (10) The ability to convey the material smoothly when it is sent to a printer.

In addition, images recorded by inkjet recording methods have traditionally been used exclusively for surface image observation, but as the performance of inkjet recording devices has improved and become more widespread, recording materials suitable for purposes other than surface image observation have become available. Applications of recorded materials other than 0 surface image observation, which are becoming increasingly required, include projecting recorded images onto a screen, etc. using an optical device such as a slide or 0HP (overhead projector), and observing those images. , color separation plates for creating positive plates for color printing, and CMFs (color mosaic filters) used for color displays such as liquid crystals.

When a recording material is used for surface image observation, the diffused light of the recorded image is mainly observed, whereas for recording materials used in these applications, the problem is mainly the transmitted light of the recorded image. Become. Therefore, it is required to have excellent light transmittance, especially linear light transmittance, in addition to the above-mentioned performance requirements of the general recording material for inkjet recording.

(The problem that the invention is trying to solve) However,
The reality is that there is still no known recording material that satisfies all of these required performances.

Furthermore, most conventional recording materials for surface image observation use a method in which a porous ink-receiving layer is provided on the surface, and a recording liquid is received in the porous voids to fix the recording agent.

On the other hand, when the surface of the ink-receiving layer is non-porous, non-volatile components such as polyhydric alcohols in the ink remain on the surface of the recording material for a long time after recording, and the drying and fixing time of the ink is long. However, there are disadvantages in that clothing may get dirty or the recorded image may be damaged if it comes into contact with the recorded image.

An object of the present invention is to provide a recording material for inkjet recording that is particularly excellent in ink receptivity and the clarity of recorded images.

Still another object of the present invention is to use an optical device such as a slide or an OHP to project a recorded image onto a screen for observation, a color separation plate when creating a positive plate for color printing, or a liquid crystal display. An object of the present invention is to provide a translucent recording material for inkjet recording that can be used for observation of transmitted light such as CMF used in color displays.

Furthermore, the commonly required qualities of the recording material are that it should be able to feed the recording material smoothly without clogging when handled and put through the printer, that is, it should have good transportability; During storage, it is necessary to improve the product value by ensuring that it does not stick and block, and that it does not attract fingerprints when touched. The present invention also provides a recording material for inkjet recording that also has such necessary performance.

As a result of extensive research in order to achieve the above object, the inventor of the present invention has found that the ink receiving layer has a structure of two layers, an ink retaining layer and an ink permeable layer, and preferably a three layer structure including a fine powder layer. This has made it possible to obtain a recording material that is suitable for the ink-receiving layer.

However, when recording on the recording material with a large amount of ink,
Although the ink is accepted, the printed area becomes cloudy, and when this recorded image is used for transmitted light observation such as OHP, the cloudy area becomes dark in the projected image, which may cause problems such as decreased color development. Ta.

As a result of further research, we succeeded in obtaining a recording material that does not have cloudy printed areas and has excellent ink receptivity and color development according to the present invention described below.

(Disclosure of the Invention) That is, the present invention provides a recording material having an ink receiving layer consisting of an ink retaining layer and an ink permeable layer, in which the ink permeable layer has a thickness of 0.01 to 0. The recording material is made of a polyurethane resin having a thickness of less than IILm.

To explain the present invention in detail, the recording material of the present invention has an ink permeable layer made of a polyurethane resin and having a specific thickness, that is, a thickness of less than 0.01 to 0.1 gm, on the ink retaining layer. The main feature is that a fine powder layer is provided thereon, and the object of the present invention is mainly achieved thereby.

The recording material of the present invention generally includes a base material as a support, an ink retaining layer provided on the surface thereof, an ink permeable layer of a specific thickness made of polyurethane resin provided on the ink retaining layer, and preferably a It consists of a fine powder layer as the upper layer,
For example, particularly preferred main embodiments include (1) an embodiment in which the base material, the ink retaining layer, and the ink permeable layer (and the fine powder layer) are all translucent, and the recording material as a whole is translucent; (2) Examples include an embodiment in which at least one of the base material, ink retaining layer, and ink permeable layer (and fine powder layer) is opaque, and the recording material as a whole is opaque.

In any of the above cases, the ink retaining layer may also have the function of a support.

The present invention will be explained in more detail using the above two preferred embodiments as representative examples.As the base material that can be used as a support in the present invention, any of the conventionally known base materials such as transparent and opaque base materials can be used. Examples of suitable transparent substrates include polyester resins, diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride resins, polyimide resins, cellophane, and celluloid. Examples include films or plates such as, and glass plates. Preferred examples of the opaque substrate include, for example, general paper, cloth, wood, metal plates, synthetic paper, and the like, as well as the above-mentioned transparent substrates treated to make them opaque by known means. Preferably, such substrates have a thickness in the range of about 10 to 2001 Lm.

The ink retaining layer in the present invention is mainly formed from a water-soluble or hydrophilic material capable of retaining water-based ink, and preferred examples of such materials include:
Albumin, gelatin, casein, starch, cationic starch, gum arabic, natural resins such as sodium alginate, polyamide, polyacrylamide, polyvinylpyrrolidone, quaternized polyvinylpyrrolidone, polyethyleneimine, polyvinylpyricillium halide, melamine resin, polyurethane, carboxylic acid Methyl cellulose, polyvinyl alcohol, cation-modified polyvinyl alcohol,
Examples include synthetic resins such as polyester and sodium polyacrylate, and in the present invention, the most preferred materials are:
It is a water-soluble resin such as polyvinylpyrrolidone, polyvinyl alcohol, and/or polyacrylic resin that can form a layer that can quickly and stably hold ink several times its own weight. One or more of these materials may be used according to point 9.

Furthermore, in order to reinforce the strength of the ink retaining layer and/or improve the adhesion with the base material, SBR latex, NBR latex, polyvinyl formal, polymethyl methacrylate, polyvinyl butyral, polyacrylonitrile, polyvinyl chloride may be added as necessary. , polyvinyl acetate, phenol resin, alkyd resin, etc. may be used in combination with the water-soluble resins mentioned above.

As a method for forming such an ink retaining layer, a coating solution is prepared by dissolving or dispersing the above-mentioned polymers alone or in a mixture in an appropriate solvent, and the coating solution is coated by, for example, a roll coating method, It is preferable to apply the coating onto the substrate by a known method such as a rod percoat ink method, an air knife coating method, or a spray coating method, and then dry it immediately. Either a single ink retaining layer is formed by a known method such as the T-die method, and the ink retaining layer is used to have the function of a support.
By a method of laminating the sheet on the base material, a method of hot melt coating the polymer material, etc.
An ink retaining layer may be formed on the base material.

The thickness of the ink holding layer formed in this way may be within a range that can hold the ink, and although it depends on the amount of ink to be recorded, it is not particularly limited as long as it is 0.1 gm or more. Practically speaking, a range of 0.5 to 304 m is suitable.

The ink permeable layer used in the present invention and which primarily characterizes the present invention is a thin layer made of polyurethane resin provided on the ink retaining layer formed as described above. When a droplet of ink is deposited, the contact area is rapidly expanded (e.g., within a few seconds) to the extent that the droplet does not overlap excessively with other adjacent droplets, and the droplet penetrates into the ink-retaining layer. , and has a function of promoting ink reception by the ink retaining layer.

The inventor of the present invention has conducted extensive research with the aim of imparting the above-mentioned functions to the ink-retaining layer and also being able to project beautiful color images on OHP even immediately after printing with a color inkjet printer, and found that polyurethane resin The thickness of the ink permeable layer consisting of 0. It has been found that the function described in L can be easily achieved by setting the distance to less than O1 to 0.14 m. It was truly surprising that such a function could be achieved not only by a hydrophilic polyurethane resin, but also by a thin layer of a hydrophilic polyurethane resin that is hardly soluble in water.

The polyurethane resin material useful for forming such a thin layer is an addition polymer of a polyisocyanate compound and a compound having two or more active hydrogens, such as a polyol, a polyamine, or a polycarboxylic acid. Any of these can be used. Particularly preferred materials are:
The polyisocyanate compound and the polyol compound are
Using a terminated NGO urethane prepolymer obtained by reaction with an excess of GO, the prepolymer is coated on the ink-retaining layer with a suitable chain extender, such as water, hydrazine, low molecular weight polyol, low molecular weight polyamine, low molecular weight alcohol amine. It is obtained by polymerization and crosslinking using methods such as the following.

Polyisocyanates useful in forming polyurethanes or urethane prepolymers having two isocyanate groups include 1,2-diisocyanateethane, 1,2-diisocyanatepropane, tetramethylene-1,4-diisocyanate, pentamethylene- 1,
5-diisocyanate, hexamethylene-1,6-diisocyanate, nonamethylene-1,9-diisocyanate, decamethylene-1,10-diisocyanate, ω,
ω'-dipropyl ether diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, hexahydrodiphenyl-4°4'-diisocyanate, hexahydrodiphenyl ether-4,4'-diisocyanate, phenylene- 1,4-diisocyanate, tolylene-2,
6-diisocyanate, tolylene-2,4-diisocyanate, 1-methoxybenzene-2゜4-diisocyanate, -riocr phenylene diisocyanate, tetrachlorophenylene diisocyanate, metaxylylene diisocyanate, paraxylylene diisocyanate,
Diphenylmethane-4,4'-diisocyanate, diphenylsulfide-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, diphenyl ether 4,4'-diisocyanate, diphenyl ether 3,4'-diisocyanate, diphenyl ketone- 4,4'-diisocyanate, naphthalene-1,
4-diisocyanate, naphthalene-1,5-diisocyanate, 2,4'-biphenyl diisocyanate, 4
．． 4'-biphenyl diisocyanate, 3゜3'-dimethoxy-4,4'-biphenyl diisocyanate, andraquinone-2,6-diisocyanate, triphenylmethane-4,4'-diisocyanate, azobenzene-
Examples include 4,4'-diisocyanate.

Examples of compounds containing three incyanate groups include triphenylmethane triisocyanate, compounds represented by the following structural formulas (I) to (rV), and derivatives of these compounds. , one or more of these compounds can be selected and used as desired to form the polyurethane or urethane prepolymer.

(I) 0 0CN (CH, enter N HCN H(CH2), N C
0 (margin below) (m) (CH,), N C
0■ (■) 0 In addition, as a compound having two or more active hydrogens, a preferable one is a hydrophilic polyol, and as a suitable polyol, a polyester polyol, a polyether polyol, a polyester polyether polyol are preferable. A polyester polyol is a compound made from a polybasic acid and a polyhydroxy compound.

Hydroxy terminated polyesters are preferred. As polybasic acids, saturated fatty acids such as oxalic acid, succinic acid, adipic acid, and pimelic acid, unsaturated fatty acids such as maleic acid and fumaric acid, aromatic acids such as phthalic acid and isophthalic acid, or their anhydrides may be used alone or in combination. As the polyhydroxy compound, one or two types of diols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol, triols such as trimethylolpropane, trimethylolethane, hexanetriol, and glycerin, and hexaols such as sorbitol are used. The above can be used in combination.

Such polyester polyols generally have low hydrophilicity, so if a hydrophilic polyurethane resin is required, use one that has an unsaturated group as part of the raw material polybasic acid, and use it as a polyester polyol. It is preferable to make it wood-philic by a known method such as glat polymerization of sulfonic acid groups, cationic groups, or water-soluble monomers by utilizing the unsaturated groups present after or after forming the polyurethane.

The polyether polyol used in the present invention is a compound that contains two or more hydroxyl groups in one molecule and has an ether bond, and is a homopolymer or copolymer of ethylene oxide (EO) and propylene oxide (PO). and polyhydric alcohols such as glycerin, triols such as trimethylolpropane, hexanetriol, hexaols such as sorbitol, or ethylenediamine, benzenesulfamite, 2-aminoethanolamine,
EO or PO for amines such as N-methyljetanolamine, diethylenetriamine, and amines with aromatic groups.
Examples include polyols formed by optionally adding , or derivatives thereof.

These can be used alone or in combination of two or more. The polyester polyether polyol is obtained by condensing the above polybasic acid and polyether polyol so as to form terminal hydroxyl groups.

Other polyols include, for example, castor oil, tall oil or their derivatives, acrylic polyols, urethane polyols, and the aforementioned low molecular weight polyhydric alcohols can also be used as polyol components. Furthermore, it goes without saying that the various polyols mentioned above can be used alone or as a mixture.

Conventionally known methods are used to produce the polyurethane as described above. As an example, a compound having active hydrogen and a polyisocyanate compound having the same number of moles or more as the active hydrogen group are heated at 30 to 120°C for 30 minutes to 1 hour.
It can be synthesized by reacting for 68 hours using dibutyltin dilaurate or triethylene diamine as a catalyst if necessary.

In the production of polyurethane, the aforementioned low molecular weight polyols, low molecular weight diamines, low molecular weight alcohol amines, water, hydrazine, etc. are used as chain extenders.

The polyurethane or terminal isocyanate urethane prepolymer consisting of the above components can be prepared by any known method, but as the terminal isocyanate urethane prepolymer, commercially available ones,
For example, a prepolymer which is an adduct of tolylene diisocyanate and various polyester polyols or polyether polyols and has a terminal incyanate can also be used.

Furthermore, the urethane polymer may be a blocked urethane prepolymer stabilized by blocking its terminal NCO.

Polyurethane or urethane prepolymers made of such components can also be used with other polymers, such as homopolymers or copolymers made of vinyl acetate, acrylic esters, ethylene, vinyl chloride, other vinyl monomers, and vinyl monomers such as those mentioned above. and various wood-philic vinyl monomers, furthermore, vinylon,
It can also be used in combination with polymers such as cellulose derivatives, polyesters, and polyamides, and the above-mentioned wood-philic polymers for forming the ink-retaining layer.

The polyurethane or urethane prepolymer described above may be used in any state, including as a solution in an organic solvent, as an emulsion in an aqueous medium, or as a fine dispersion in an organic solvent or an aqueous medium. When used as an organic solvent solution, it is preferable to use a relatively dilute solution or a concentration such that the layer formed falls within the above range.

The method for forming the ink permeable layer using the above materials can be the same as the method for forming the ink retaining layer described above, but the thickness of the ink permeable layer to be formed is 0.01.
It is necessary to make it less than ~O, lpm. If the thickness of the ink permeable layer exceeds 0.1 gm, the printed area will become cloudy when recording with a large amount of ink, and such recorded images will not be OH.
When projected with P, etc., light is scattered in the cloudy part, the recorded part of the projected image becomes dark, and the ink does not develop the original color, which is not preferable.On the other hand, if the thickness of the ink transmission layer is 0.
If it is less than 0.01 gm, no improvement in ink receptivity due to the ink permeable layer is observed, which is not preferable.

In the recording material of the present invention having the basic structure as described below, the thickness of the ink permeable layer is from 0.01 to less than 0.1 gm, and its hydrophilicity is equal to the woodophilicity of the ink retaining layer. It is surprising that the recording material of the present invention has significantly improved ink receptivity compared to a recording material without such an ink permeable layer, although it is equivalent or inferior. .

Although the theoretical basis for such a surprising effect is currently unknown, it is based on the inventor's mere imagination (the present invention is not limited in any way by such mere imagination). The above-mentioned ink permeable layer is not necessarily a continuous film; there are countless microscopic gaps in the ink permeable layer that allow water-based ink to penetrate into the ink holding layer, and the surface is irregular within a very small range. , so that the deposited ink droplet quickly spreads on its surface and
It is thought that the contact area between them is expanded, and therefore the ink receptivity of the ink retaining layer is significantly promoted. Further, in the recording material of the present invention, the ink permeable layer is formed as a thin layer of 0.01 to less than 0.1 gm from hydrophilic polyurethane, which has the same or inferior hydrophilicity compared to the ink holding layer. Therefore, the ink adhering to one surface does not remain in the ink permeable layer, which has a low ink holding capacity, but quickly passes through the ink permeable layer, and is retained and fixed in the ink holding layer, which has a high ink holding capacity. Furthermore, the powder that is preferably used in the present invention and that is the second characteristic of the present invention is a powder that is applied on the above-mentioned ink permeable layer, and when the recording material is applied to a printer, it has excellent ink receptivity. It also has the function of exhibiting smooth conveyance and eliminating protrusion when a large number of recording materials are stacked.

As a result of various studies aimed at achieving the above-mentioned functions, the present inventors have discovered that the above-mentioned functions can be achieved by applying a certain type of powder onto the ink-permeable layer.

One particle size of powder with the above-mentioned functions is 2071 m.
The following fine powders are preferred, such as silica, clay, talc, diatomite, calcium carbonate, calcium sulfate,
barium sulfate, aluminum silicate, synthetic zeolite,
Examples include inorganic powders such as alumina, zinc oxide, lithopone, and satin white. Examples of organic powders include higher fatty acids or their salts, such as aluminum stearate, calcium stearate, and anionic, cationic, nonionic, and amphoteric powders. Examples of surfactants that are solid at room temperature include sodium dodecylbenzenesulfonate, sodium laurylsulfonate, potassium laurylsulfonate, sodium stearylsulfonate, and polyethylene glycol nonylphenyl ether with relatively high HLB. Such powder is deposited on the ink permeable layer at a density of about 0.
It is preferable to apply it at a rate in the range of 0.01 to 1.0 g/m''.

To apply the above-mentioned materials, powder particles may be applied directly, or they may be dispersed or suspended in a suitable liquid (for example, water). Examples of methods include dipping, coating, spraying, roller coating, electrostatic adsorption, and the like.

The preferred recording material of the present invention having the above-mentioned basic structure has better ink receptivity, ink fixing property, blocking resistance, and fingerprint resistance compared to a recording material without powder on the ink permeable layer. It is surprising that the properties and transportability within the printer are significantly improved.

The amount of powder applied to the permeable layer and the powder itself have many capillary voids, and due to the capillary action, the ink diffuses through the powder at a high speed, spreading over a wide area. and reaches the permeable layer. Therefore, it is thought that the synergistic effect with the powder applied to the permeable layer significantly improves ink receptivity, ink fixability, and transportability.

Furthermore, since the powder is applied to the top layer, it is possible to achieve functions that are important in practical terms, such as preventing fingerprints and blocking during stacking.

The above is the basic structure of the present invention, but in an embodiment in which the recording material of the present invention is translucent, a translucent material is used as the base material, and an ink retaining layer, an ink permeable layer and a fine powder layer are used. When forming these layers, it is necessary to ensure that their translucency is not impaired. However, to the extent that the translucency is not impaired, for example, silica, clay, talc, diatomaceous earth, etc.
Fillers such as calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, synthetic zeolite, alumina, zinc oxide, lithopone, satin white, etc. can also be dispersed in the ink retaining layer and/or the ink permeable layer.

In the present invention, sufficient light transmittance means that the recording material exhibits a linear light transmittance of at least 2% or more, and preferably a linear light transmittance of 105 or more.

If the linear light transmittance is 2% or more, it is possible to project and observe the recorded image onto a screen using OHP, for example, and in order to clearly observe the details of the recorded image,
It is preferable that the linear light transmittance is 105 or more.

The linear transmittance T (%) here refers to the amount of light incident perpendicularly to the sample, transmitted through the sample, and at least 8
C■ Measure the spectral transmittance of the straight light that passes through the light-receiving side slit on the extension line of the incident optical path that is further away than that and is received by the detector using, for example, the Hitachi Model 323 self-recording spectrophotometer (manufactured by Hitachi, Ltd.). Then, from the measured spectral transmittance, the Y value of the tristimulus value of the color is determined, and the value is determined by the following formula.

T=Y/Y, Light transmittance (install an integrating sphere behind the sample to determine light transmittance including diffused light), opacity (
The white and black backings are placed on the back of the sample and the ratio is calculated. ), which evaluates translucency using diffused light.

Since the problem with devices that use optical technology is the behavior of straight-line light, it is important to evaluate the straight-line transmittance of the recording material to be used in such devices. Determining the light index is particularly important.

For example, when observing a projected image on an OHP, in order to obtain a clear and easy-to-see image with high contrast between recorded and non-recorded areas, it is necessary that the non-recorded areas of the projected image be bright, that is, the straight line transparency of the recording material. It is required that the light rate be at a certain level or higher. In OHP tests using test charts, in order to obtain images suitable for the above purpose,
The in-line transmittance of the recording material should be 2% or more, preferably 105 or more to obtain a clearer image, and more preferably 50% or more. A recording material suitable for this purpose must have an in-line transmittance of 2% or more.

Further, in an embodiment in which the recording material of the present invention is opaque, an opaque material may be used for at least one layer among the base material, ink retaining layer, ink permeable layer, and fine powder layer.

The method of forming each layer used in this embodiment is the same as in the transparency embodiment described above.

In this opaque embodiment, when forming the ink retaining layer and the ink permeable layer, it is possible to use a large amount of the filler to the extent that film forming properties are not impaired, thereby further improving excellent ink receptivity and fixing properties. can.

The present invention has been explained above by illustrating typical aspects of the recording material of the present invention, but of course the recording material of the present invention is not limited to these aspects. Also, the ink retaining layer and/or ink permeable layer may contain various known additives such as dispersants, fluorescent dyes, pH adjusters, antifoaming agents, lubricants, preservatives, and surfactants. In addition, the ink permeable layer further contains various stabilizers such as organotin stabilizers such as dibutyltin maleinate and dioctyltin mercaptide, and polyphosphite and trisnonylphenyl phosphite as anti-yellowing agents for polyurethane. can be included.

Note that the recording material of the present invention does not necessarily have to be colorless, and may be a colored recording material.

As described above and as demonstrated in the Examples below, the recording material of the present invention as described above has significantly improved ink receptivity, stability over time, characteristics during printing, etc. For example, during full-color recording, even if different colors of recording liquid adhere to the same spot repeatedly within a short period of time, the recording liquid will not run out or seep, and images will be produced with high resolution, clarity, and excellent color development. is obtained. In addition, the printing diameter has excellent OHP suitability, and even when used for observation by projecting the recorded image onto a screen etc. using an optical device such as a slide or OHP, the adhered ink droplets are smaller than with conventional recording materials. Since the printed image is enlarged and fixed to the extent that it does not overlap excessively with other adjacent areas, the transmitted light becomes even more uniform, and there is no clouding of the printed area, resulting in a projected image with excellent uniform density. It is something to give. Furthermore, it can be suitably applied to uses other than conventional surface image observation, such as a color separation plate when creating a positive plate for color printing, or a CMF used in a color display such as a liquid crystal.

Hereinafter, the present invention will be explained in more detail according to Examples. Note that parts and percentages in the text are based on weight.

Examples 1 to 4 A polyethylene terephthalate film (manufactured by Toshi Co., Ltd., Q80) with a thickness of 100 IL was used as a translucent base material, and a 10% aqueous solution of the composition for forming an ink retaining layer shown in Table 1 below was added to the film. The composition for forming an ink permeable layer shown in Table 1 was coated using a bar coater method to the thickness shown in Table 1 and dried at 120°C for 3 minutes. Apply a 1% acetone solution to the thickness shown in Table 1 using a bar coater method, dry at 100°C for 1 minute, and then apply a fine powder layer as shown in Table 1. The mixture was sprayed and deposited at the indicated ratio to obtain a translucent recording material of the present invention.

Comparative Examples 1 and 2 Comparative recording materials were obtained in the same manner as in Examples 1 and 3, except that the ink permeable layer was not provided.

Comparative Examples 3 and 4 In Examples 1 and 2, the thickness of the ink permeable layer was 14
A recording material for comparison was obtained in the same manner as in Examples 1 and 2, except that m was used.

Comparative Example 5 In Example 1, the thickness of the ink permeable layer was changed to 0.005J.
A comparative recording material was obtained in the same manner as in Example 1, except that Lm was used.

The following four types of ink were used on the recording materials obtained in Examples 1 to 4 and Comparative Examples 1 to 5, using an on-demand inkjet recording head (discharge orifice) that discharges ink using a piezo vibrator. Inkjet recording was performed using a recording device having a final layer diameter of 60 mm, a piezo vibrator drive voltage of 70 V, and a frequency of 2 KHz.

Yellow ink (composition) C0! , Dai Left Yellow 86 2 parts diethylene glycol 20 parts polyethylene glycol #200 10 parts water
70 parts Magenta ink (composition) G, 1. Acid Red 35 2 parts diethylene glycol 20 parts polyethylene glycol #
200 10 parts water
70 parts Cyan ink (composition) C, 1, Direct Blue 86 2 parts diethylene glycol 20 parts polyethylene glycol #2
00 10 parts water
70 parts Black ink (composition) C, 1, Food black 2 2 parts diethylene glycol 20 parts polyethylene glycol #
200 10 parts water
70 copies The evaluation results of the recording materials of the above Examples and Comparative Examples are shown in Table 2 below. Each evaluation item in Table 2 was measured according to the following method.

(1) Ink fixation time was measured by measuring the time required for the ink to dry and stop adhering to the finger when touching the recorded image after recording.

(2) The dot density was calculated using Sakura Microdensidometer PD by applying JISK7505 to the printed microdots.
The black dots were measured using M-5 (manufactured by Konishiroku Photo Industry).

(3) OHP suitability was determined by printing 6 dots on the same cylinder, projecting the recorded image onto a screen using OHP, and visually observing it in order to evaluate the cloudiness of the printed area and optical suitability.

O: The recorded area is bright, and the recorded images are O and D.

It has a high optical density and can produce projected images with excellent contrast and color development and clarity.

×: The printed area is dark due to cloudiness, and the color development and clarity are poor.

Δ: Something between O and ×.

(4) Straight line transmittance was determined by measuring the spectral transmittance using a 323-type Hitachi self-recording spectrophotometer (newly manufactured by Hitachi Seisakusho), keeping the distance from the sample to the light-receiving side at approximately 9c+s, and measuring the spectral transmittance as described above ( 1) It was calculated using the formula.

(Issuance of procedural amendment) September 1985 core date

Claims (2)

[Claims] (1) In a recording material having an ink receiving layer consisting of an ink retaining layer and an ink permeable layer, the ink permeable layer is 0.0
A recording material comprising a polyurethane resin having a thickness of 1 to less than 0.1 μm. (2) The recording material according to claim (1), wherein the ink permeable layer has a fine powder layer thereon.