JP3325123B2 - Recording sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording sheet for recording using a color material. In particular, the present invention relates to a recording sheet for forming an image sheet by inkjet recording, thermal transfer recording, electrophotographic recording, or the like.

[0002]

2. Description of the Related Art In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and apparatuses suitable for each information system have been developed and adopted. Among such recording methods, in ink recording using an ink jet or a plotter, and in thermal transfer recording using a melting type color material or a sublimation type color material, a device used is light and compact, and noise is reduced. And excellent in operability and maintainability.
Further, the apparatus used in such a recording method has been widely used recently because of easy colorization. In the conventional electrophotographic system, colorization has been advanced, and high-resolution, full-color printers and copiers have been developed and commercialized.

Various ink-jet systems have been developed. The physical methods are roughly divided into a method using a dye solution containing a water-soluble dye (aqueous ink) and a method using a dye solution containing an oil-soluble dye (oil-based ink). And a method in which a low-melting solid wax (wax ink) containing a dye is heated and melted. The mainstream is a type using an aqueous ink. In any case, the method is to form an image by ejecting liquid fine droplets onto the ink recording sheet.

The thermal transfer method is roughly classified into two types. The first method is to apply a heat-fusible ink coated on a support to the support and apply heat from the support to melt the ink into a pattern. Is a method of transferring an image to a recording sheet to obtain an image (fusing heat transfer). In the second method, a heat-sensitive recording material comprising a resin having a high softening point and a sublimable dye is coated on a support in the same manner as the former. This is a method (sublimation heat transfer) in which a sublimation dye is sublimated in a heat-applied pattern and transferred to a recording sheet to obtain an image. The mainstream of the electrophotographic method is a method in which an electrostatic latent image is formed by giving a light pattern to a charged photoconductive layer, transferred to a recording sheet after toner development, and melted and fixed with toner by heat.

On the other hand, in the following applications, it is necessary to use a transparent sheet. In many cases, an image is formed as described above using a transparent film provided with a color material receiving (absorbing) layer on the surface thereof. Create For example, OHP films that are increasingly used in place of slides in meetings, etc.,
Examples thereof include a film for a backlight display, which is increasingly used in place of a printed poster and a display board, and a film for a second original drawing.

[0006] The transparent film on which an image is formed by these recording methods can be used in addition to the hue, saturation, and brightness of the obtained image.
It is necessary that the color material is firmly adhered to the surface of the recording sheet, and in the case of ink jet recording, it absorbs the liquid ink quickly to obtain a fine image, and there is no ink bleeding or ink accumulation, In addition, it is required that the ink hardly bleeds due to adhesion of water (water resistance).

In order to solve these problems, various proposals have hitherto been made. For example, in the case of ink jet recording, a recording material using a cationic polymer such as a dimethylammonium chloride polymer or a cation modified product of polyvinyl alcohol is disclosed in JP-A-59-206.
No. 96 or JP-A-60-245585. These are based on the effect of penetration of aqueous ink by the hydrophilic groups or dissociable groups of the polymer.Thus, even if the film is thickened, a sufficient ink absorption rate cannot be obtained, and the suppression of color mixing bleeding is insufficient. Was not satisfactory, and the water resistance was not sufficient.

Further, a method of using a porous inorganic pigment in the colorant receiving layer is disclosed in JP-A-55-144172 and JP-A-5-144172.
JP-A-6-148584, JP-A-56-148585, JP-A-62-273881, JP-B-3-2
4906 and JP-A-60-245588. Further, methods using various types of silica particles are disclosed in JP-A-55-51583 (use of non-colloidal silica), JP-A-56-148585 (use of finely divided silica), and JP-A-61-19389. It is proposed in a gazette (use of colloidal silica). Although the porosity of the layer is generally high and the ink absorption rate is high in many cases, the suppression of color mixture bleeding is insufficient and the image resolution is not satisfactory.

A recording material having a colorant receiving layer containing silica particles surface-treated with a silane coupling agent is disclosed in JP-A-62-178384 and Japanese Patent Publication No. 3-2.
No. 4905. Although the resolution is somewhat improved, the porosity is reduced, so that the ink absorbency cannot be satisfied.

[0010]

SUMMARY OF THE INVENTION The present inventors have made various studies to obtain a recording sheet having a sufficient image absorbance and a sufficient suppression of color mixture bleeding and a high image resolution. Then, after forming the color material receiving layer, it was found that the recording sheet with high resolution can be obtained by applying, impregnating and drying a solution of a silane coupling agent having a quaternary ammonium salt. By impregnating the color material receiving layer with the solution of the silane coupling agent, the silane coupling agent enters into a large number of voids of the color material receiving layer, and is adsorbed on the surface of the void, reacting with each other, and a cured product. To form Such a coloring material receiving layer of the present invention can be said to be a layer in which a cured product of the silane coupling agent is uniformly held in a number of voids of the coloring material receiving layer. Therefore, the coloring material receiving layer of the present invention is a layer in which the quaternary ammonium salt that adsorbs the dye is uniformly held in the layer while maintaining a high porosity, and therefore, the ink absorbing property and the color mixing bleeding are suppressed. It is considered that the film exhibits excellent characteristics with sufficient suppression and high image resolution.

Accordingly, an object of the present invention is to provide a recording sheet having a color material receiving layer from which an image sheet can be obtained by ink jet recording, thermal transfer recording or electrophotographic recording. In particular, the present invention provides a recording sheet suitable for inkjet recording, which can rapidly absorb liquid ink, can obtain a fine image without ink bleeding or ink accumulation, and has excellent water resistance. Aim.

[0012]

The object of the present invention is to provide a recording sheet having a color material receiving layer provided on a support, wherein the color material receiving layer comprises silica having an average primary particle diameter of 10 nm or less.
A solution containing a silane coupling agent having a quaternary ammonium salt on the surface of a layer made of fine particles and a water-soluble resin,
This can be achieved by a recording sheet characterized by being a layer obtained by coating and drying.

Preferred embodiments of the recording sheet of the present invention are as follows. 1) The recording sheet, wherein a cured product in which the silane coupling agents are bonded to each other is formed. 2) The recording sheet, wherein the colorant receiving layer is a layer having a large number of voids. 3 ) The recording sheet, wherein the water-soluble resin is polyvinyl alcohol. 4 ) The above silica fine particles (hereinafter referred to as inorganic fine particles )
There) and the weight ratio of the water-soluble resin is 1.5: 1 to 10: The recording sheet in the 1 range. 5 ) The recording sheet as described above, wherein the colorant receiving layer has a light transmittance of 70% or more. 6 ) The recording sheet as described above, wherein the colorant receiving layer has a porosity of 50% or more. 7 ) The above recording sheet for ink jet recording, wherein the layer thickness of the colorant receiving layer is 10 to 50 μm. 8 ) The above-mentioned recording sheet for electrophotography or thermal recording wherein the layer thickness of the colorant receiving layer is 0.1 to 10 μm. 9 ) The silane coupling agent is 100 to 3600 m
g / m ² (preferably 250~2200mg / m ²⁾ in the range, the recording sheet is contained by the coating. The content of the silane coupling agent was determined using a trace total nitrogen analyzer (TN-10, manufactured by Mitsubishi Kasei Co., Ltd.).
It was determined by quantitative analysis of nitrogen atoms.

The recording sheet of the present invention has a basic structure comprising a support and a color material receiving layer formed on the support. The recording sheet of the present invention can be manufactured, for example, as follows.

As a material that can be used as the support, it is preferable to use a material that is transparent and has a property of resisting radiant heat when used in a backlight display, but it is preferable to use an opaque support such as paper. Is also good. Examples of the material for the transparent support include polyesters such as polyethylene phthalate; cellulose esters such as nitrocellulose, cellulose acetate, and cellulose acetate butyrate; and polysulfone, polyphenylene oxide, polyimide, polycarbonate, and polyamide. Of these, polyethylene phthalate is preferred. The thickness of the support is not particularly limited, but a thickness of 50 to 200 μm is preferred because it is easy to handle. The support may be one subjected to a corona discharge treatment, a flame treatment, or an ultraviolet irradiation treatment.

The colorant receiving layer of the present invention contains a water-soluble resin and inorganic fine particles as main components, and further contains a silane coupling agent having a quaternary ammonium salt or a cured product thereof. The silane coupling agent having a quaternary ammonium salt of the present invention or the colorant receiving layer containing a cured product thereof is a silane coupling agent having a quaternary ammonium salt or a self-cured product (crosslinked product) thereof. (A layer using inorganic fine particles, especially fine silica particles, is considered to have a myriad of fine voids, into which the coupling agent enters, and is hardened.) Is). Also, a silane coupling agent,
The cured product and the like may be present inside and on the surface of the color material receiving layer and sometimes inside the color material receiving layer. In the present invention, it is preferably present inside and on the surface.

The colorant receiving layer of the present invention can be produced, for example, as follows. Examples of the water-soluble resin include resins having a hydroxyl group as a hydrophilic structural unit, such as polyvinyl alcohol (PVA), cellulosic resins (methyl cellulose (MC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), and carboxymethyl cellulose (CMC). ), Etc.), chitins and starch; resins having ether linkages such as polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene glycol (PEG) and polyvinyl ether (PVE); and resins having amide groups or amide linkages Examples include polyacrylamide (PAAM) and polyvinylpyrrolidone (PVP). Further, a polyacrylate having a carboxyl group as a dissociable group, a maleic acid resin, an alginate and gelatins; a polystyrene sulfonate having a sulfone group, an amino group, an imino group, a tertiary amine and a quaternary ammonium salt. Having polyallylamine (P
AA), polyethyleneimine (PEI), epoxidized polyamide (EPAm), polyvinylpyridine and gelatins.

The inorganic fine particles have an average primary particle diameter of 1
Silica fine particles of 0 nm or less (preferably 3 to 10 nm)
Is used .

Since the silica particles tend to adhere to each other due to hydrogen bonding due to silanol groups on the surface, the average primary particle diameter is 10 nm or less (preferably 3 to 10 n) as described above.
In the case of m), a structure having a large porosity can be formed. Silica particles are roughly classified into a wet method and a dry method according to the production method. In the wet method, active silica is mainly produced by producing active silica by acid decomposition of silicate, polymerizing the silica appropriately, and coagulating and sedimenting to obtain hydrated silica. On the other hand, fumed silica is
High-temperature gas-phase hydrolysis of silicon halide (flame hydrolysis method), and silica sand and coke are reduced and vaporized by heating in an electric furnace by an arc and oxidized with air (arc method) to produce anhydrous silica. The method of obtaining is the mainstream. These hydrated silica and anhydrous silica have a density of silanol groups on the surface,
Although there is a difference in the presence or absence of vacancies and the like, they exhibit different properties, but in the case of silicic anhydride (anhydrous silica), a three-dimensional structure having a particularly high porosity is easily formed, which is preferable. Although the reason for this is not clear, the density of silanol groups on the surface of hydrated silica is as large as 5 to 8 particles / nm ^2, and the particles are likely to be densely aggregated (aggregate). It is presumed that coarse soft coagulation (flocculate) results in a structure having a high porosity because the number is small per unit / nm ² .

From the viewpoint of transparency, the type of the resin to be combined with the silica fine particles is important.
VA, especially low saponification degree (preferably 70-90% saponification degree)
PVA is preferred in terms of light transmission. PVA has a hydroxyl group in the structural unit, and it is considered that this hydroxyl group and a silanol group on the surface of the silica particle form a hydrogen bond, thereby easily forming a three-dimensional network structure in which the secondary particle of the silica particle is a chain unit. . Thereby, it is considered that a coloring material receiving layer having a structure having a high porosity can be obtained. In the ink jet recording, the color material receiving layer thus obtained not only can rapidly absorb ink by the capillary phenomenon and can perform fine recording without ink bleeding and ink accumulation, but also the color material in thermal recording, and The toner in photographic recording can be firmly adhered. The reason for this is that the coloring material and the toner penetrate into the pores of the porous layer, and as a result, the coloring material and the like are firmly fixed by the shape anchor effect caused by the three-dimensional network structure. Further, since the ratio of the inorganic fine particles is large, the heat resistance is high and the emboss resistance in electrophotographic recording is also high.

The ratio of the inorganic fine particles (preferably silica fine particles) to the water-soluble resin (PB ratio: the weight of the inorganic fine particles with respect to the weight of the water-soluble resin of 1) greatly affects the film structure. As the PB ratio increases, the porosity, pore volume, and surface area (per unit weight) increase. If it exceeds 10, there is no effect on the film strength and cracking during drying,
If it is less than 1.5, the voids are closed by the resin, the porosity decreases, and the ink absorption performance decreases. Therefore, the PB ratio is 1.5 to 1
A range of 0 is preferred. In particular, in the case of direct contact by hand, such as an OHP film, it is necessary to obtain a sufficient film strength.
The ratio is particularly preferably 5 or less, and in order to obtain high-speed ink absorptivity with an ink jet printer, the PB ratio is particularly preferably 2 or more. Therefore, the PB ratio is more preferably in the range of 2 to 5.

For example, when the average primary particle diameter as described above is 1
0 nm or less of anhydrous silica and a water-soluble resin having a PB ratio of 2 to 5
When completely dispersed in an aqueous solution and dried by application, a three-dimensional network structure having secondary particles of silica particles as a chain unit is formed, the average pore size is 30 nm or less, the porosity is 50% or more, and the pore specific volume. 0.5ml / g or more, and a specific surface area of 100m ² / g
The light-transmitting porous film (colorant receiving layer) can be easily formed.

The colorant receiving layer of the present invention is obtained by further applying a solution containing a silane coupling agent having a quaternary ammonium salt to the layer containing the above-mentioned inorganic fine particles and a water-soluble resin as main components, and drying. Layer. That is, a cured product of a silane coupling agent mainly having a quaternary ammonium salt is adhered and contained in the voids of the layer composed of the inorganic fine particles having a myriad of voids and the water-soluble resin. Such a layer is generally coated with a coating material for forming a colorant receiving layer, dried, then coated (or impregnated) with a solution (or dispersion) containing the silane coupling agent, and dried (preferably heat-treated). ) Can be formed.

In the colorant receiving layer of the present invention, a self-cured silane coupling agent having a quaternary ammonium salt is adsorbed on the surface of the layer and adsorbed and contained in numerous voids in the layer. Depending on conditions, an unreacted silane coupling agent may remain. The coloring material receiving layer of the present invention containing a cured product of such a silane coupling agent having a quaternary ammonium salt in the voids can form a fine image without ink bleeding or ink accumulation, and is excellent. Water resistance. That is, since the ink is adsorbed and fixed by the quaternary ammonium salt, and the silane coupling agent having the quaternary ammonium salt is mainly cured (crosslinked) or fixed, the ink moves due to the adhesion of water or the like. It is thought that there is not. As the silane coupling agent having a quaternary ammonium salt, a compound having a quaternary ammonium salt and a di- or trialkoxysilanyl group is preferable. Examples of preferred silane coupling agents include (1) 3- (trimethoxysilyl) propyldimethyloctadecyl ammonium chloride, (2) N-β
-(N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane and (3) 3- (trimethoxysilyl) propyldimethylhydroxyethylammonium chloride. These chemical formulas are shown below.

[0025]

Embedded image

In the curing of the silane coupling agent, a plurality of alkoxysilanyl groups are converted to silanol groups in the presence of water (possible with moisture in the air), and the silane coupling agents are combined (preferably by heating). , By a condensation reaction between silanol groups to form a crosslinked structure. The above compound (including the surface) in the colorant receiving layer, preferred to be contained in a range of 100~3600mg / m ^2, further 250~2200mg / m
² is preferred.

In the case of ink jet recording, the layer thickness of the colorant receiving layer needs to have an absorption capacity to absorb all the liquid droplets, and this needs to be determined in relation to the porosity of the coating film. For example, when the ink amount is 8 nl / mm ² and the porosity is 60%, a film of about 15 μm or more is required.
In the case of ink jet recording, the range is preferably 10 to 50 μm. In the case of thermal transfer or electrophotography, since a colorant or toner is adsorbed on the surface, a thin film is sufficient, and the thickness is preferably 0.1 to 10 μm.

The inorganic fine particles and the water-soluble resin which mainly constitute the color material receiving layer may be a single material or a mixture of a plurality of materials. The colorant receiving layer is mainly composed of the above-mentioned inorganic fine particles and a water-soluble resin, but may further contain various inorganic salts and an acid alkali as a pH adjuster in order to enhance the dispersibility of the particles. In addition, various surfactants may be used for the purpose of improving coating suitability and surface quality.
Even if it contains surfactants with ionic conductivity or metal oxide fine particles with electronic conductivity to suppress triboelectric charging or exfoliation charging of the surface, or to adjust surface electrical resistance in electrophotography Good. Further, a mordant may be used for the purpose of fixing a dye and increasing water resistance in ink jet recording. Further, various matting agents may be included for the purpose of reducing the friction characteristics of the surface. Further, various antioxidants and ultraviolet absorbers may be contained for the purpose of suppressing the deterioration of the coloring material.

An undercoat layer may be provided between the colorant receiving layer and the transparent support for the purpose of increasing the adhesiveness or adjusting the electric resistance. Further, the colorant receiving layer may be provided on one side of the transparent support, or may be provided on both sides to suppress curl and the like. When the color material receiving layer is provided only on one surface, an anti-reflection film may be provided on the opposite surface to enhance light transmittance. Refractive index ( _nr ) of this antireflection film
, If the refractive index of the transparent support is n _s nearby n _s ^1/2,
The film thickness is preferably close to λ / 4n (where λ is the wavelength of the OHP lamp used).

The colorant receiving layer before the application of the silane coupling agent can be provided on a support, for example, as described below. The coating material for forming a colorant receiving layer has an average primary particle size of 1
Silica fine particles of 0 nm or less are added to water (eg, 1
0 to 15% by weight), using a high-speed rotating wet colloid mill (eg, CLEARMIX (manufactured by M Technique Co., Ltd.)) at 10,000 rpm (preferably 5000 to 2).
After dispersing for 20 minutes (preferably 10 to 30 minutes) under the condition of high-speed rotation of 0000 rpm), an aqueous solution of polyvinyl alcohol (for example, so that the weight of PVA is about 1/3 of the weight of silica) is added. It can be obtained by performing dispersion under the same conditions as described above. The coating liquid thus obtained is a uniform sol, and by forming this on a support by the following coating method, a colorant receiving layer having a three-dimensional network structure of the present invention can be obtained. it can. That is, the coating solution of the uniform sol is coated on a support and then dried to evaporate water as a solvent. A wet gel is formed when the coating film reaches a gelation concentration due to this evaporation, and a porous xerogel is formed by further drying, and a coloring material receiving layer (hereinafter referred to as “coating”) before applying the silane coupling agent This is referred to as "the previous colorant receiving layer").

The formation of the colorant receiving layer before the coating is performed, for example, by applying a coating solution obtained by further adding an antistatic agent or the like to the coating solution if desired on the support (film).
It can be carried out by heating and drying. The coating can be performed by a known coating method such as an air doctor coater, a bread coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, and a bar coater. Drying is generally 50
Performed at １８０180 ° C. for 0.5-30 minutes. After drying with a hot air dryer at a relatively low temperature (preferably 50 to 90 ° C. (wind speed 3 to 8 m / sec)) for 0.5 to 3 minutes, it is further dried at a relatively high temperature (preferably 120 to 180 ° C. (20 minutes) is preferable from the viewpoint of preventing cracking during drying of the colorant receiving layer before coating, particularly when the film thickness is large.

On the obtained color material receiving layer before coating, a coating solution (solution) containing a silane coupling agent having a quaternary ammonium salt of the present invention is applied in the same manner as the formation of the color material receiving layer. It is applied by a method and dried to form the colorant receiving layer of the present invention. The coating liquid is prepared, for example, by dissolving the above compound in an organic solvent (eg, methanol, ethanol and isopropyl alcohol) or dispersing it in water, preferably to have a concentration of 0.1 to 20% by weight. You. The coating amount is such that the above-mentioned compound is contained in the colorant receiving layer in the amount described above (10
(In the range of 0 to 3600 mg / m ² ). Drying requires heating above the temperature at which the compound cures, and is generally performed at 50 to 180 ° C for 0.5 to 60 minutes, preferably at 80 to 150 ° C for 5 to 30 minutes.

Further, after coating and drying, it is possible to improve the surface smoothness, transparency and coating strength by, for example, passing between roll nips under heating and pressure with a super calender, gloss calender or the like. However, since such a process lowers the porosity (that is, the ink absorbency decreases), it is necessary to perform the treatment under a condition in which the porosity does not decrease much.

[0034]

【Example】

Example 1 (1) Composition of Coating Solution for Forming Coloring Material Receptive Layer (All parts by weight indicating the blending amounts of the following coating solutions all represent solid or non-volatile components) Dry Silica Fine particles (average primary particle diameter: 7 nm; 10 parts by weight; refractive index: 1.45; Aerosil A300 (manufactured by Nippon Aerosil Co., Ltd.)) polyvinyl alcohol (saponification degree 88%; degree of polymerization 3500; 3.3 parts by weight PVA235 ( (Kuraray Co., Ltd.) Ion-exchanged water 136.0 parts by weight of silica fine particles were added to ion-exchanged water (73.3 parts by weight), and a high-speed rotary wet-type colloid mill (CLEARMIX (M Technic) 1)
After dispersing at 0000 rpm for 20 minutes, an aqueous solution of polyvinyl alcohol (dissolved in the remaining 62.7 parts by weight of ion-exchanged water) was added, and the mixture was further dispersed under the same conditions as above to form a colorant receiving layer. An application liquid was obtained.

This coating solution was subjected to corona discharge treatment on the surface of biaxially stretched polyethylene terephthalate having a thickness of 100 μm, and the surface was applied using an air knife coater.
After drying for 1 minute at 70 ° C. (wind speed 5 m / sec) using a hot air drier, further drying was performed at 100 ° C. for 10 minutes. Thus, a color material receiving layer having a dry film thickness of 30 μm was formed.

(2) Composition of silane coupling agent solution having quaternary ammonium salt 3- (trimethoxysilyl) propyldimethyl 5 parts by weight octadecyl ammonium chloride (compound of (1) above; silane coupling agent, Polon MF -50: manufactured by Shin-Etsu Chemical Co., Ltd.) 95 parts by weight of methanol The above solution was applied onto the above color material receiving layer using a # 3.1 bar coater at an application amount (solid content) of 1100 mg / m ^2. Thereafter, heating was performed at 120 ° C. for 5 minutes to form a colorant receiving layer treated with a silane coupling agent having a quaternary ammonium salt. Thus, a recording sheet for ink jet was obtained.

Example 2 In Example 1, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (in place of 3- (trimethoxysilyl) propyldimethyloctadecyl ammonium chloride) Ink-jetting was carried out in the same manner as in Example 1 except that the compound (2), the silane coupling agent, and SZ6032 silane: manufactured by Toray Silicone Co., Ltd.) were used and the coating amount (solid content) was changed to 1070 mg / m ^2. A recording sheet was prepared.

Example 3 In Example 1, 3- (trimethoxysilyl) propyldimethylhydroxyethylammonium chloride (compound (3)) was used in place of 3- (trimethoxysilyl) propyldimethyloctadecyl ammonium chloride. Example 1 except that the coating amount (solid content) was changed to 1200 mg / m ² using
In the same manner as described above, a recording sheet for ink jet was produced.

Comparative Example 1 In Example 1, a cationic polymer (KR-850, Arakawa Chemical Industries, Ltd.) was used instead of a methanol solution of 3- (trimethoxysilyl) propyldimethyloctadecyl ammonium chloride.
) Was prepared in the same manner as in Example 1 except that the solution (5% by weight) was used.

[Comparative Example 2] In Example 1, amorphous silica (Syloid 404: manufactured by Fuji Devison Chemical Co., Ltd.) treated with aminopropyltriethoxysilane was used instead of the dry silica fine particles (Aerosil A300). A coating material for forming a colorant receiving layer was prepared, and a coating solution for inkjet was prepared in the same manner as in Example 1 except that a solution of a compound having a plurality of functional groups capable of reacting with a quaternary ammonium salt was not applied. A recording sheet was prepared.

The ink-jet recording sheet obtained above was evaluated for its suitability for ink-jet by the following measuring method. (1) Ink absorption speed Immediately after printing (approximately 10 seconds) a black solid on a recording sheet by an ink jet printer (PIXEL JET; manufactured by Canon Inc.), the paper is contacted and pressed to transfer the ink to the paper. The presence or absence was determined as follows. AA: No ink was transferred to paper. CC: Ink was transferred to paper. (2) Bleeding of Ink Color Mixing Using the same printer as above, the determination was made based on the degree of bleeding at the boundary of the solid black printed portion printed on the recording sheet. AA: There was no seepage. BB: Slight bleeding was observed. CC: Exudation was considerably observed. (3) Dot diameter Using the same printer as above, the diameter of the dots printed on the black ink recording sheet was measured with a microscope. (4) Water resistance Using the same printer as above, the recording sheet on which the black ink was printed was immersed in water for 60 seconds, then taken out, observed for the degree of ink bleeding, and evaluated as follows. AA: There was almost no seepage. BB: Slight bleeding was observed. CC: Exudation was considerably observed. (5) Parallel light transmittance haze meter (HGM-2DP; Suga Test Instruments Co., Ltd.)
Was used to measure the parallel light transmittance. The results of the above evaluation are shown in Table 1 below.

[0043]

[Table 1] Table 1 イ ン ク Ink Ink dot diameter Water resistance Transmittance Absorption rate Mixed color bleed (μm) (%) ──────────────────────────────────── Example 1 AA AA 99 AA 80.5 Example 2 AA AA 101 AA 81.2 Example 3 AA AA 100 AA 83.0 ────────────────────────────── ────── Comparative Example 1 BB BB 112 BB 69.6 Comparative Example 2 BB BB 130 BB 31.0 ──────────────────────────── ────────

[0044]

According to the recording sheet of the present invention, in ink jet recording, a liquid ink can be rapidly absorbed and a fine image free of ink bleeding and ink accumulation can be obtained. Further, the obtained image has excellent water resistance, and even if water or the like is excessively adhered to the recording sheet, almost no bleeding of the image occurs. Further, since it is excellent in ink absorbency and prevention of bleeding, the adhesiveness of a coloring material or a toner is improved in thermal transfer recording and electrophotographic recording. Therefore, it can be said that the recording sheet of the present invention is a recording sheet suitable for various recording methods.

Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) B41M 5/00 B41M 5/38-5/40 G03G 7/00

Claims (4)

(57) [Claims] 1. A recording sheet comprising a support provided with a color material receiving layer, wherein the color material receiving layer has an average primary particle size of
A recording layer characterized by being a layer obtained by applying and drying a solution containing a silane coupling agent having a quaternary ammonium salt on the surface of a layer made of silica fine particles having a diameter of 10 nm or less and a water-soluble resin. Sheet. 2. The recording sheet according to claim 1, wherein the colorant receiving layer has a light transmittance of 70% or more. 3. The weight ratio of silica fine particles having an average primary particle diameter of 10 nm or less to a water-soluble resin is 1.5: 1 to 10: 1.
The recording sheet according to claim 1 or 2, wherein 4. The recording sheet according to claim 1, wherein the support is transparent.