JPS6157378A - Recording material - Google Patents

Abstract

PURPOSE:To enhance absorptivity to a water base ink and clearness of recorded images, by constituting a recording material of an ink-holding layer comprising a hydrophilic resin absorbent of water base inks, an ink-permeable layer comprising a water-resistant polyurethane, and a powder layer. CONSTITUTION:The ink-holding layer comprising a hydrophilic resin absorbent of water base inks is provided on the surface of a support base, and the ink-permeable layer comprising a substantially water-resistant polyurethane and the powder layer are laminated on the ink-holding layer to produce the recording material. The hydrophilic resin may be a hydrophilic natural resin such as albumin and gelatine, a hydrophilic synthetic resin such as polyamide and polyacrylamide or the like, and the thickness of the ink-holding layer is prefereably 5-30mum. The thickness of the in-permeale layer is preferably 0.1-5mum. A powder for forming the powder layer is preferably an inorganic or organic powder with a particle diameter of not larger than 20mum.

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 in particular, to improve ink receptivity, clarity of recorded images,
The present invention relates to a recording material that is excellent in conveyability in a printer, anti-blocking property, etc., and when the recording material is a translucent recording material, has excellent ink receptivity and translucency.

(Prior Art) The inkjet recording method uses 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 allows for 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 made of a base material called ordinary paper or inkjet recording paper provided with a porous ink absorbing layer. However, as the performance of inkjet air distribution devices improves and becomes more widespread, such as faster recording speeds and multicolor recording, more sophisticated and wide-ranging properties are being required of recording materials. That is, it can be used as a recording material for inkjet recording to obtain high-resolution, high-quality recorded images.

(1) The ink should be fixed on the recording material as quickly as possible.

(2) Even if ink dots overlap, the ink deposited later will not flow into the dots deposited earlier; (3) the ink droplets will spread to some extent on the recording material;
(4) The shape of the ink dot should be close to a perfect circle and its circumference should be smooth; (5) The OD (optical density) of the ink dot should be ) should be high and the area around the dot 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 multicolor inkjet recording, in addition to meeting the above-mentioned performance requirements, (6) the coloring properties of the coloring components of the ink must be met.

(7) Since the same number of droplets as the number of ink colors may curl and adhere to the same spot, the ink fixing property must be particularly excellent; (8) The surface must be glossy.

(9) High whiteness; (10) Smooth conveyance when applied to a printer.

In addition, images recorded by inkjet recording 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. Other uses for recorded materials other than 0 surface image observation, which are becoming increasingly required, include recording images projected onto a screen using optical equipment such as slides and 0HP (overhead/overhead projectors), and observing those images. Examples include those used for color printing, 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 absorbing layer is provided on the surface, and a recording liquid is absorbed into the porous voids to fix the recording agent.

On the other hand, when the surface of the ink absorption 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 transmitted light in, 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 not causing blocking due to adhesion due to the coating agent, and not allowing fingerprints to adhere when touched by the human hand.The present invention also provides such necessary performance. The present invention also provides a recording material for inkjet recording, which is equipped with the following.

The above and other objects of the invention are achieved by the following invention.

(Disclosure of the Invention) That is, the present invention is a recording material comprising an ink retaining layer, an ink permeable layer and a fine powder layer, and the ink permeable layer is made of a polyurethane resin.

To explain the present invention in detail, the main feature of the recording material of the present invention is that an ink permeable layer made of a polyurethane resin is provided on the ink retaining layer, and a fine powder layer is further provided on the ink permeable layer. Primarily, the objectives of the invention have been achieved thereby.

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

To explain the invention 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 conventionally known base material such as transparent or opaque 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, and glass plates. Preferred opaque substrates include, for example, general paper, cloth, wood,
Metal Plate 1 In addition to synthetic paper, the above-mentioned transparent base material may be made opaque by known means. Preferably, such substrates have a thickness in the range of about 10-200 pm.

In the present invention, the ink retaining layer in the present invention is mainly formed from a water-soluble or hydrophilic material that can accept 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, carboxymethylcellulose, polyvinyl alcohol, cationic Examples include synthetic resins such as modified polyvinyl alcohol, polyester, and sodium polyacrylate. Furthermore, in the present invention, the most preferred material is polyvinyl, which can form a layer that can quickly and stably hold ink several times its own weight. Water-soluble resins such as pyrrolidone, polyvinyl alcohol and/or polyacrylic resins. One or more of these materials may be used as desired.

Furthermore, in order to reinforce the strength of the ink retaining layer and/or improve the tightness with the base material, SBR latex, NOR latex, polyvinyl formal,
Resins such as polymethyl methacrylate, polyvinyl butyral, polyacrylonitrile, polyvinyl chloride, polyvinyl acetate, phenolic resins, alkyd resins, etc. may be used in combination with the above water-soluble resins.

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 base material by a known method such as a rot bar coating 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 a die method and used so that the ink retaining layer also has the function of a support, or
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 Omura.

The thickness of the ink retaining layer formed in this way may be within a range capable of retaining 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 pm or more. Practically speaking, a range of 0.5 to 30 Bm 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 made extensive research in order to impart the above-mentioned functions to the ink-retaining layer, and unexpectedly found that the polymer constituting the ink-retaining layer was coated with hydrophilic or hydrophilic polymers. It has been discovered that the above function can be easily achieved by forming a thin layer of polyurethane resin of inferior quality. 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 ink permeable layer having the above functions is made of a polyurethane resin having hydrophilicity equivalent to that of the polymer material forming the ink retaining layer, or a polyurethane resin having relatively poor hydrophilicity. The following was achieved by forming a thin layer, preferably with a thickness in the range of about 0.1-5 pm.

A polyurethane resin material useful for forming such a thin layer is an addition polymer of a polyinocyanate compound and a compound 1 having two or more active hydrogens, such as a polyol, a polyamine, or a polycarboxylic acid. Any known material 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 inocyanate groups include polyester, 2-diisocyanate ethane, 1,2-diisocyanate furopane, and tetramethylene-1,4-diisocyanate 5-pentane. methylene-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'-diincyanate, hexahydrodiphenyl-4°4'-diisocyanate, hexahydrodiphenyl ether-4,4'-diisocyanate,
Phenylene-1,4-diincyanate, toluylene-
2,6-diisocyanate, toluylene-2゜4-diincyanate, 1-methoxybenzene-2,4-diincyanate, 1-chlorophenylene diisocyanate,
Tetrachlorophenylene diisocyanate, metaxylylene diisocyanate, paraxylylene diisocyanate, diphenylmethane-4,4'-diincyanate,
Diphenylsulfide-49,4'-diincyanate, 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, anthraquinone-2,6-diisocyanate, triphenylmethane-4,4'-diisocyanate, azobenzene-4,4'-diisocyanate etc. can be mentioned.

Examples of compounds containing three isocyanate groups include 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.

00N(CH, enter N HCNH(CH,),N GO(
■) 0 ○ (■) 0 Also, preferred compounds having two or more active hydrogens are hydrophilic polyols, and suitable polyols include polyester polyols, polyether polyols, and polyester polyether polyols. Polyester polyols are compounds produced from polybasic acids and polyhydroxy compounds, with terminal hydroxy polyesters being 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 use the unsaturated groups present after or after forming the polyurethane to make it wood-philic by a known method such as graph Ifff combination with a sulfonic acid group, a cationic group, or a water-soluble hexamer. .

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 to amines such as N-methyljetanolamine, diethylenetriamine, and amines with aromatic groups.
Examples include polyols formed by optionally adding , or derivatives thereof, and these can be used alone or in combination of two or more. The polyester polyether polyol is obtained by condensing a polybasic acid as described above and a polyether polyol so as to form terminal hydroxyl groups.

Examples of such polyols include 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.

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.

Polyurethane or inocyanate-terminated urethane prepolymer 7A consisting of the above-mentioned components can be produced by any known method. Naturally, a prepolymer which is an adduct of polyester polyol or polyether polyol and has an incyanate terminal can also be used.

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

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

The polyurethane or urethane prepolymer as described above may be used in the form of a solution in an organic solvent, an emulsion in an aqueous medium, or a fine dispersion in an organic solvent or an aqueous medium. It is preferable to use these polymers in a relatively dilute solution or in a concentration such that the layer formed falls within the above range.

The method for forming an ink permeable layer using the above-mentioned materials is to apply the above-mentioned resin liquid to a certain thickness on the ink-retaining layer and then dry it. Preferably, micropores are created in the thin layer formed by the treatment.

Preferred methods for forming such a thin layer with micropores are as follows: (1) When forming a thin layer, a moisture-curable urethane prepolymer reacts with moisture to generate gas, and the part where the gas evaporates is A method of creating a microporous layer by leaving micropores in the thin layer.

(2) Mix or dissolve an inorganic or organic fine powder non-foaming agent in the above resin dissolved or dispersed in a polar or non-polar solvent, and apply heat when or after forming a thin layer on the ink retaining layer. (3) A volatile solvent that is relatively incompatible with the resin liquid used in (2) is dispersed, emulsified or solubilized by stirring, and a thin (4) a method of creating micropores by volatilizing the solvent during layer formation or after formation; (4) a material that is more soluble in organic solvents or water than the resin in the resin liquid; For example, after mixing low-molecular materials or polymers and forming a thin layer from a resin liquid, a highly soluble material is mixed with an organic solvent or water that does not damage the formed thin layer or ink-receiving layer. (5) A thin polyurethane layer generally known as an ultrafiltration membrane, ie, a resin filtration membrane, and a reverse osmosis membrane.

(6) Coating using an emulsion or dispersion of polyurethane or urethane prepolymer in an organic solvent or water; Examples include a method in which a particle layer made of polyurethane particles is formed by drying at a temperature that does not cause fusion or excessive fusion.

In the above method, the moisture-curable urethane prepolymer used is preferably a terminal NGO urethane prepolymer obtained by reacting a polyisocyanate and a polyol by NCO perforation. Examples of solvents include benzene, toluene, acetone,
Lower alcohols, petroleum solvents, water, etc. are suitable, and inorganic or organic blowing agents include ammonium carbonate, -i
t, ammonium nitrite, dinitrosopentamethylenetetramine, azodicarbonamide, azobisinbutyronitrile, P-toluenesulfocolhydrazide, 4.4
'-oxybis(benzenesulfonylhydrazide), diazoaminobenzene, diphenylsulfone-3,3'-
Disulfonyl hydrazide etc. are suitable, and the soluble material used in method (4) may be a low-molecular material or a polymer as long as it has higher solubility than the resin that is the film forming material. , is suitable when the thin layer is a cured or crosslinked film. Further, the particle size of the emulsion or dispersion used in the method (6) above is about 0.01
A range of 0.54 m is preferred.

The thickness of the ink permeable layer made of polyurethane resin formed in this manner is not particularly limited as long as it is 10g,m or less, although it depends on the amount of ink required for recording. A range of .1 to 5 pm is suitable. It is also possible to form the permeable layer using a material that causes the permeable membrane to swell or dissolve and collapse the micropores after the water-based ink permeates through it, but generally it is not suitable for use under high temperature and high humidity conditions. Formation of a permeable layer that is not easily swollen or dissolved by water-based ink so that it can be used even under harsh conditions such as, and protects the ink-retaining layer under such conditions. The size of the porous pores in the permeable layer made as described above is preferably 0.2 nm, since the water particle size is generally considered to be 0.2 nm. It is sufficient to have holes of the above number, but in the case of a translucent recording material, it is better to have holes of 1100 nm or less.

Although the hydrophilicity of the ink-permeable layer of the recording material having the above-mentioned basic structure is equal to or inferior to the wood-philicity of the ink-retaining layer, the recording material has the following basic structure. It is surprising that ink receptivity and ink fixing properties are significantly improved compared to conventional recording materials that do not exist.

This surprising effect is due to the fact that the ink-permeable layer is porous, with countless tiny pores that allow water-based ink to penetrate into the ink-retaining layer, and its surface is irregular on a microscopic scale. As a result, the adhered ink droplets quickly diffuse on the surface, expanding their contact area, and due to the capillary action of countless micropores, the ink absorption and fixing properties of the ink retaining layer are significantly improved. It is something that is being promoted.

In addition, in the above-mentioned recording material, the ink permeable layer can be formed from polyurethane, which has the same or lower hydrophilicity than the ink retaining layer. The ink does not leak to the surface and contaminate equipment, operators, or the surrounding area, and the surface is less likely to become sticky under high temperature and high humidity conditions.

Furthermore, the powder used in the present invention and secondly characterizing the present invention is a powder applied on the above-mentioned ink permeable layer,
A product that exhibits excellent ink fixation and smooth conveyance when the recording material is run through a printer, and also has the ability to eliminate protrusion when a large number of recording materials are stacked. It is.

As a result of intensive research to develop the above-mentioned mechanism, the present inventors have discovered that the above function can be achieved by applying a certain type of powder onto the ink permeable layer.

As for the powder having one function as mentioned above, the particle size is 20gm.
The following fine powders are preferred: 1 For example, silica, clay, talc, diatomaceous powder, calcium carbonate, calcium sulfate,
Barium sulfate, silicate aluminum, synthetic zeolite,
Inorganic powders include alumina, zinc oxide, lithopone, satin, white, etc.; organic powders include higher fatty acids or salts thereof, such as aluminum stearate, calcium stearate, anions, cations, etc.
Nonionic and amphoteric surfactants that are solid at room temperature, such as sodium dodecylbenzenesulfonate, sodium laurylsulfonate, potassium laurylsulfonate,
Examples include sodium stearyl sulfonate and polyethylene glycyl nonylphenyl ether with relatively high HLB. Such powder is deposited on the ink permeable layer at approximately 0.
．． It is preferable to apply it at a rate in the range of 0.01 to 1.0 g/rn'.

In order to apply the above materials, powder particles may be applied directly, or they may be applied by dispersing or suspending them in a suitable liquid (for example, water). Methods for applying the above material to the ink-permeable layer include dipping, brushing, spraying, roller coating, electrostatic adsorption, and the like.

The recording material of the present invention having the above-mentioned basic structure has better ink receptivity, ink fixation, blocking resistance, and fingerprint resistance than a recording material that does not have powder on the ink permeable layer. Moreover, it is desirable that transportability within the printer should be 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 the characteristics that are considered important from a practical standpoint, such as no fingerprints and no blocking during stacking.

The above is the basic configuration of the present invention, but in an embodiment in which the recording material of the present invention is translucent, 2! When using a translucent material as the iSi material and forming the ink retaining layer, ink permeable layer, and fine powder layer, it is necessary to ensure that the translucency of these layers is not impaired. However, to the extent that the translucency is not impaired, for example, silica, clay, talc, diatomaceous earth, calcium carbonate, calcium sulfate, etc.
barium sulfate, aluminum silicate, synthetic zeolite,
Fillers such as 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%, and preferably a linear light transmittance of 10% or more.

If the linear light transmittance is 2% or more, it is possible to project the recorded image onto a screen using OHP and observe it, and even more, the details of the recorded image can be seen! ! ! # In order to be observed brightly, it is desirable that the linear transmittance is 10% or more.

The linear transmittance T (%) here refers to the incident perpendicular to the X pull, transmitted through the sample, and at least 8
The spectral transmittance of the straight light that passes through the light-receiving side slit on the extension line of the incident optical path separated by more than cm and is received by the detector is measured using, for example, the 323-type Hitachi self-recording spectrophotometer (manufactured by Hitachi, Ltd.). The Y value of the tristimulus value of the color is determined from the measured spectral transmittance, and is determined by the following equation.

'r='y/y, X100 (1)
T: Linear transmittance Y: Y value of sample Y; Y value of blank Therefore, the linear transmittance referred to in the present invention is for straight light, and the diffuse transmittance (when an integrating sphere is placed behind the sample) ) and 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.

The problem with devices that use optical technology is the behavior of straight-line light, so when evaluating the light transmittance of the recording material to be used in those devices, it is important to check the straight-line transmittance of the recording material. It is particularly important to seek

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 10% or more to obtain a clearer image, and more preferably 50% or more. Therefore, 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.

Although the present invention has been described above by exemplifying one typical aspect of the recording material of the present invention, the recording material of the present invention is of course not limited to these aspects. In any embodiment, the ink retaining layer and/or the ink permeable layer may contain known agents such as dispersants, fluorescent dyes, pH adjusters, antifoaming agents, side lubricants, preservatives, and surfactants. In addition, the ink permeable layer can contain various additives such as
Further, as an anti-yellowing agent for polyurethane, various stabilizers such as organic tin stabilizers such as dibutyltin maleate and dioctyltin mercaptide, polyphosphite, trisnonylphenylphosphite, etc. 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.

The recording material of the present invention as described above is as described above in IJJ and as demonstrated in the Examples below.

The reception and fixation of ink has been significantly improved. For example, when recording in monochrome as well as full color, even when recording liquids of different colors adhere to the same spot repeatedly within a short period of time, the recording liquid can be easily fixed. There is no bleeding or bleed-out phenomenon, and high-resolution, clear images with excellent color development can be obtained. Also, when using optical equipment such as slides and OHPs to project recorded images onto a screen etc. for observation,
Compared to the case of conventional recording materials, the attached ink droplets are enlarged and fixed to the extent that they do not overlap other adjacent areas too much, and the transmitted light becomes more even. This provides a projected image with excellent uniform density. 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 method of the present invention will be explained in more detail according to Examples. In addition, in the first sentence, "part" means heavy iHTs Bp.

Example 1 A polyethylene terephthalate film (manufactured by Ondai) with a thickness of 1 OOp, rs was used as a translucent base material, and coating liquid A having the following composition was applied onto this film so that the film thickness after drying was 2.
Coat by bar coater method so that it becomes 0 JLm, 6
The ink retaining layer was formed by drying at 0°C for 20 minutes.Next, the following coating solution B was applied onto the ink retaining layer so that the dry film thickness was 34 m.1Then, at 70°C for 5 minutes. It is cured to form a porous ink-permeable layer, and then clay (kaolin clay, manufactured by Ueya Kaolin, particle size distribution 0.1 to 51 Lm) is applied at a rate of 1.0 g/rrr'. A translucent recording material of the present invention was obtained.

Coating liquid A composition: Styrene maleic acid half ester copolymer (Discoat N-14゜Daikyo Seiyaku Co., Ltd.) 15 parts water
85 parts Coating liquid B, 1 composition: Polyether polyurethane (Tricoat G, manufactured by Taiho Industries) 201 parts Acetone 80 parts The thus obtained recording material of the present invention was colorless and transparent.

Example 2 Mica (sericite FS) was used instead of the powder in Example 1.
The recording material of the present invention was obtained in the same manner as in Example 1, using 1.1, manufactured by Sanshin Koko Co., Ltd., particle size distribution: 0.5 to 5 pm). (Powder adhesion amount: 0.8 g/m') Example 3 Anhydrous silicon oxide (Erosil M, 0X-801 manufactured by Nippon Aeroseal, average particle size 0.03 fiLm) was used in place of the powder in Example 1. A recording material of the present invention was obtained in the same manner as in Example 1. (Powder adhesion amount 0
, 1 g/m') Example 4 A polyethylene terephthalate film (manufactured by Music University) with a thickness of l 00 p, rs was used, and coating liquid A having the following composition was applied onto this film so that the film thickness after drying was Coating was performed using the 8-coater method to give a coating thickness of 100 lm.

After drying at 80°C for 1 hour to form an ink retaining layer, the following coating solution B was applied onto the ink retaining layer to a dry film thickness of 14 m, and dried at 80°C for 10 minutes. Then, a 5% by weight aqueous dispersion of hydrous silicon dijoide (Syroid #161, manufactured by Fuji Davison, average particle diameter Full m) was made into an aqueous dispersion, and 0.2 g of water was sprayed onto the ink permeable layer. The ink retaining layer and the ink absorbing layer were then peeled together from the polyethylene terephthalate film to obtain a translucent recording material of the present invention.

Coating liquid composition: 10 parts polyvinyl alcohol (PVA 220, manufactured by Kuraray)
water
90 parts Coating liquid B composition: Water-dispersible urethane resin (Superflex 200° Industrial Pharmaceutical Type) 20 parts water
80 parts Example 5 The recording material of the present invention was prepared in the same manner as in Example 4, except that instead of the powder in Example 4, Urai) F, Nitto Funka Co., Ltd., particle size distribution: 0605-3 pm) was used for calcium carbonate. (Powder adhesion amount 0.5 g/rn').

Example 6 The procedure was repeated in the same manner as in Example 4, except that Diatom ± (Radiolite, manufactured by Showa Kagaku Kogyo, particle size distribution: 0°5 to 5 JLm) was used in place of the powder in Example 4.

A recording material of the present invention was obtained (powder adhesion amount 0.4 g/rn
').

Comparative Examples 1 to 2 Recording materials for comparative examples were obtained in the same manner as in Examples 1 and 4, except that no powder was applied in Examples 1 and 4.

For the recording materials obtained in Examples 1-6 and Comparative Examples 1-2, the following 4M! Inkjet recording is performed using an on-demand inkjet recording head (discharge orifice diameter 65 mm, piezo oscillator drive voltage 70 mm, frequency 3 KHz) that discharges ink using a piezoelectric vibrator. was carried out.

Yellow ink (composition) G, 1. Direct Yellow 86 2 parts N-methyl-
2-pyrrolidone 10 parts diethylene glycol
20 parts polyethylene glycol #200 15 parts water 55
Part magenta ink (composition) C, 1, acid red 35 2 parts N-methyl-2-pyrrolidone 10 parts diethylene glycol
20 parts polyethylene glycol #2 CIO 15 parts water 5
5 parts Cyan ink (composition) C, 1, Direct Blue 86 2 parts N-methyl-
2-pyrrolidone 10 parts diethylene glycol
20 parts polyethylene glycol #200 15 parts water 5
5 parts black ink (set f&) C, 1, food black 2 2 parts N-methyl-2-pyrrolidone 10 parts diethylene glycol
20 parts polyethylene glycol 9200 15 parts water 5
Table 1 shows the evaluation results of the recording materials of the above Examples and Comparative Examples. Each evaluation item in Table 1 was measured according to the following method.

(1) The ink fixation time was measured by leaving the recording material at room temperature after recording and measuring the time taken for the ink to dry and no longer adhere to the finger when touching the recorded image with the finger.

(2) The dot density was measured for black dots using Sakura Microdensidometer PDM-5 (manufactured by Konishiroku Photo Industries) by applying JIS K 7505 to printed microdots.

(3) OHP suitability is determined by ΔIll as a typical example of optical equipment.
This was determined by projecting the recorded image onto a screen using an OHP and visually observing it.The non-recorded area is bright, the recorded image has a high OD (optical density), and the projection is clear and easy to see with high contrast. The resulting image is O1: the non-recorded area is slightly dark, and the OD of the recorded image is
If the line is slightly low and the pitch width is 0.5 mm and the thickness is 0.25 mm, the line cannot be clearly distinguished. A case where the line could not be clearly distinguished or a case where the non-recorded area and the recorded image could not be distinguished was designated as X.

(4) Linear light transmittance was measured using a 323-type Hitachi self-recording spectrophotometer (Hitachi tA), keeping the distance from the sample to the light-receiving side at approximately 9 cm, and measuring the spectral transmittance as described in (1) above. ) was calculated using the formula.

(5) Conveyance performance: The recording material was cut to the size of an A4 plate, and was run on an inkjet printer (Canon A12, 0), and evaluated by the number of times the recording material stopped moving until the end of A41i printing.

(6) Fingerprint resistance is measured by applying one finger of both hands to the recording surface of the recording material.
Evaluation was made based on the number of fingerprints left on the surface by pressing 0 fingerprints.

(7) Blocking resistance was determined by cutting the recording material to the size of A4 size, stacking 50 sheets and placing a board on top of it.
After applying a load of 100 g and leaving the film in a room for one month, the load was removed and the blocking state of the film was observed. The case where there was no blocking was expressed as 0, and the case where there was blocking was expressed as x.

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35 seconds 50 seconds 40 seconds 45 seconds 1” L Toru J1.
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Claims (1)

[Claims] A recording material comprising an ink retaining layer, an ink permeable layer and a fine powder layer, the ink permeable layer being made of a polyurethane resin.