JP2000127617A - Image recording medium and method for recording image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high dryability and a strong film quality for an application to a recent improved ink-jet printer by using a gelatin obtained by modifying at least 5C alkyldicarboxylic acid with an amino group as an ink absorbing layer on a support. SOLUTION: A modified gelatin is obtained by reacting at least 5C alkyldicarboxylic acid and its derivative with a lysine residue, i.e., an amino group in part of an amino acid residue in a gelatin molecule. An ink fixing layer contains, in addition to the modified gelatin, a polymer mordant. As the mordant, a vinyl polymer having a tertiary amino group and a vinyl polymer having a nitrogen-containing heterocyclic group are representative. The image recording medium comprises the ink fixing layer and a surface protective layer. The fixing layer is provided between the protective layer and a support, and formed of a plurality of layers. The protective layer is an ink permeable layer containing a hydrophilic polymer as a binder, and the polymer contains 50 wt.% or above of the layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording medium, and more particularly to an image recording medium suitably used in an ink jet system having improved image quality and film quality.

[0002]

2. Description of the Related Art As an image recording medium used in an ink jet system, ordinary paper or paper called an ink jet recording paper has been used. In general ink jet recording paper, an ink receiving layer is provided on paper (support). However, due to recent remarkable improvements in ink jet printers, conventional image recording media cannot provide sufficient printer performance.
Conventional image recording media have ink bleeding and cannot support the high resolution of recent inkjet printers. In addition, with the improvement in image quality, glossiness such as a photograph is required for an image, but a conventional image recording medium has low glossiness. Therefore, the image recording medium needs to be improved to the extent that the improvement of the ink jet system is achieved.

For various purposes, "modified gelatin" in which some groups in the molecular chain are modified is used as gelatin (for example, Japanese Patent Application Laid-Open Nos. 9-226232 and 9-226).
No. 99635, Japanese Patent Application Laid-Open No. 9-131963, Japanese Patent Application Laid-Open No. 9-156200, Japanese Patent Application Laid-Open No. 9-314991.
No., etc.). However, these gelatins were not always sufficient in terms of ink absorption performance.

[0004] Among these methods for improving image recording media,
In particular, the method of providing a polyolefin layer on a support is superior in that a glossy image closer to a photograph can be obtained than a conventional ink jet recording paper. However, since the support itself does not have ink absorbency, in order to obtain sufficient ink drying performance, a large amount of high ink-absorbing polymer must be used in the ink receiving layer, and the strength of the film decreases. Therefore, compatibility between drying properties and film quality was not sufficient.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image recording medium which is applied to a recently improved ink jet type printer and is preferably used. Another object of the present invention is to provide an image recording medium capable of obtaining high drying property and strong film quality. Still another object of the present invention is to provide an image recording method using the image recording medium.

[0006]

According to the present invention, the following objects (1) to (5) and an image recording method (6) are provided to achieve the above object. (1) An image recording medium characterized in that gelatin in which an amino group is modified with an alkyldicarboxylic acid having 5 or more carbon atoms is used for an ink absorbing layer on a support. (2) An image recording medium characterized by using gelatin in which an amino group is modified with an alkyldicarboxylic acid having 5 or more carbon atoms in an ink absorbing layer on a support and at least one kind of polymer mordant. (3) Two or more ink absorbing layers are formed on the support,
An image recording medium characterized by using gelatin in which an amino group is modified with an alkyldicarboxylic acid having 5 or more carbon atoms in at least one ink absorbing layer excluding an outermost surface layer. (4) Two or more ink-absorbing layers are formed on the support, and at least one ink-absorbing layer excluding the outermost surface layer has 5 carbon atoms.
An image recording medium characterized by using gelatin having an amino group modified with an alkyldicarboxylic acid and at least one polymer mordant. (5) An image recording medium, wherein two or more ink absorbing layers are formed on a support, and at least one polymer mordant is used in at least one ink absorbing layer except for the outermost surface layer. (6) The image recording medium according to any one of claims 1 to 5, wherein the support is a paper laminated with a polyolefin. (7) An image recording method, wherein an image is recorded by attaching and fixing an aqueous ink to the image recording medium according to any one of the above (1) to (6).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The modified gelatin used in the image recording medium of the present invention is different from a gelatin in which an amino group is modified with an alkyl dicarboxylic acid having 5 or more carbon atoms and an alkyl dicarboxylic acid having 5 or more carbon atoms and derivatives thereof (for example, Acid chloride) and a lysine residue in a part of the amino acid residues in the gelatin molecule, that is, an amino group (—NH ₂ ). As the gelatin used in the above reaction, gelatin generally used for photography can be used. Gelatin using animal collagen as a raw material is preferably used, and particularly, gelatin obtained from collagen using pig skin, cow skin, cow bone and the like as a raw material is preferably used. Further, the kind of gelatin is not particularly limited, and any of lime-processed gelatin and acid-processed gelatin can be used. Commercially available alkyldicarboxylic acids having 5 or more carbon atoms can be used. Specifically, glutaric acid, methyl succinic acid, adipic acid, dimethyl succinic acid, methyl glutaric acid, dimethyl glutaric acid, methyl adipic acid, pimelic acid, 3-ethyl-3-methyl glutaric acid, suberic acid, 1,2- Cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid,
And tridecanedicarboxylic acid. Particularly, those having 6 or more carbon atoms are preferably used, and those having 6 to less than 10 carbon atoms are most preferably used.

Further, the modified gelatin of the present invention and other gelatin (lime-treated gelatin, acid-treated gelatin, and derivative gelatin (for example, JP-B-38-4854 and JP-B-39-5514).
Nos. 40-12237 and 42-26345; U.S. Pat. Nos. 2,525,753 and 2,594,293
Nos. 2,614,928 and 2,763,639
Nos. 3,118,766 and 3,132,945
Nos. 3,186,846 and 3,312,553
No., British Patent Nos. 861,414 and 103,189,
Derivative gelatin described in JP-A-9-226232 and the like can be used in combination.

Further, two or more kinds of modified gelatins may be used in combination. The molecular weight of the modified gelatin is 1000-1000
000, preferably 10,000 to 20,000
More preferably, it is 0. The amount of the modified gelatin used is preferably 0.2 to 30 g / m ² ,
More preferably, it is 5 to 15 g / m ² .

The ink fixing layer preferably contains a polymer mordant in addition to the modified gelatin. Typical examples of the polymer mordant include a vinyl polymer having a tertiary amino group and a vinyl polymer having a nitrogen-containing heterocyclic group.
The tertiary amino group and the nitrogen-containing heterocyclic group may be in a quaternary ammonium state. A vinyl polymer having a nitrogen-containing heterocyclic group is preferably used. The nitrogen-containing heterocyclic group is preferably a tertiary imidazole group. The repeating unit having a tertiary imidazole group is represented by the following formula (1).

[0011]

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Wherein R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and L is a single bond or an alkylene. Group, arylene group, -CO-, -O-, -NH
And a divalent linking group selected from the group consisting of-and combinations thereof. Preferably, R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, methyl or ethyl, and more preferably a hydrogen atom or methyl. The alkylene group for L preferably has 1 to 6 carbon atoms. The arylene group for L is preferably phenylene. Regarding L, examples of combinations of an alkylene group, an arylene group, -CO-, -O- and -NH- are shown below. The left side of the following examples L ^{1 to} L ⁵ is the main chain,
The right side binds to the imidazole ring, respectively. L ¹ : -arylene group-alkylene group- L ² : -CO-O-L ³ : -CO-NH- L ⁴ : -CO-O-alkylene group- L ⁵ : -CO-NH-alkylene group- Specific examples of the repeating unit having a tertiary imidazole group represented by the above formula (1) are shown below.

[0013]

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[0014]

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[0015]

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A homopolymer comprising only a repeating unit having a tertiary imidazole group can be used as a polymer mordant. Further, a copolymer combining two or more kinds of repeating units having a tertiary imidazole group,
It may be used as a polymer mordant. Further, a copolymer obtained by combining a repeating unit having a tertiary imidazole group with another repeating unit can also be used as the polymer mordant. The proportion of the repeating unit having a tertiary imidazole group in the copolymer is preferably at least 50 mol%, more preferably at least 60 mol%. Specific examples of other repeating units are shown below.

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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Examples of copolymers obtained by combining a repeating unit having a tertiary imidazole group with another repeating unit are shown below. In the following examples, the numbers in parentheses indicate the numbers of the repeating units. The number on the right side of the parenthesis is mol% of the repeating unit.

Copolymer Tertiary imidazole unit Other unit (part 1) Other unit (part 2) CPM-1- (1) 50- (21) 50-CPM-2- (1) 90- (22) 10- CPM-3--(1) 95--(22) 5-CPM-4--(1) 90--(21) 5--(22) 5-CPM-5-(1) 95--(23) ) 5- CPM-6-(1) 95--(24) 5-CPM-7-(1) 95--(25) 5-CPM-8-(2) 95--(26) 5-CPM- 9- (7) 95--(23) 5-CPM-10-(10) 90--(25) 5--(27) 5-CPM-11-(8) 90--(28) 5-- (29) 5-CPM-12-(1) 90--(30) 5--(22) 5-CPM-13-(1) 90--(24) 5--(22) 5-CPM-14 − (1) 95− − ( 31) 5-CPM-15-(1) 90--(32) 5--(22) 5-CPM-16-(10) 90--(26) 5--(22) 5-CPM-17- (1) 62.5--(21) 31.25--(22) 6.25-

Copolymer Tertiary imidazole unit Other unit (No. 1) Other unit (No. 2) CPM-18- (1) 50- (33) 50- CPM-19- (1) 75- (22) 25- CPM-20-(1) 60--(21) 30--(22) 10- CPM-21-(1) 60--(34) 40- CPM-22-(8) 80--(35) ) 15--(36) 5-CPM-23-(1) 70--(23) 30- CPM-24-(1) 70--(24) 20--(22) 10- CPM-25-( 1) 80--(24) 20- CPM-26-(1) 65--(37) 35- CPM-27-(1) 70--(38) 30- CPM-28-(1) 65-- (39) 25--(22) 10- CPM-29-(1) 90--(40) 10- CPM-30-(2) 25--(41) 50--(42) 25- CPM-31− (1) 35− − (34) 50− − (43) 15−

Two or more polymer mordants may be used in combination. The molecular weight of the polymer mordant is 1000-1000
000, preferably 10,000 to 20,000
More preferably, it is 0. The amount of the polymer mordant used is preferably 0.2 to 30 g / m ² ,
More preferably, it is 0.5 to 15 g / m ² .

The image recording medium of the present invention comprises an ink fixing layer and a surface protective layer. The ink fixing layer is preferably provided between the surface protective layer and the support. The ink fixing layer may be composed of a plurality of layers.

The thickness of the ink fixing layer provided on the support (the total thickness when there are plural ink fixing layers) is 5 to 37 μm.
And more preferably 8 to 25 μm. The layer provided on the support preferably has an ink swelling ratio of 100 to 300% as a whole, and more preferably 150 to 250%.
The swelling ratio is a value obtained by subtracting the dry film thickness from the thickness of the coating layer measured after immersing the image recording medium in the target ink at 25 ° C. for 1 minute (the swelling value), and dividing the value by the dry film thickness ( %). Adjustment of the swelling ratio is important for controlling ink seepage and spreading, or for preventing damage in the printer. The ink-philic layer provided on the support is preferably formed by simultaneous coating, but may be formed by coating many times. Hereinafter, each layer, their components, and an image recording method will be sequentially described.

The surface protective layer is an ink-permeable layer (protective layer) using a hydrophilic polymer such as gelatin, saccharide, or water-soluble synthetic polymer as a binder. The hydrophilic polymer is 50
% By weight or more. Preferably, the hydrophilic polymer is at least 55% by weight of the layer, more preferably at least 60% by weight. The surface protective layer further contains solid particles having an average particle size of 3 to 100 μm as a matting agent. The surface protective layer preferably contains a surfactant. The surface protective layer has a function of controlling the spread and penetration of the ink. Further, the surface protective layer also has a function of physically or chemically protecting the dye image fixed to the ink absorbing layer. The surface protective layer has a thickness of 0.2 to 2 μm. The thickness is preferably from 0.3 to 1 μm. For the surface protective layer, a slip agent, a preservative, a latex, an anti-fading agent, a tinting dye, a pigment, a fluorescent thickening agent, and the like can be used as necessary.

Apart from the ink fixing layer, mainly PV
An ink fixing layer (II) using an A-based polymer as the ink receiving polymer can also be used. The PVA-based polymer of the ink fixing layer II is preferably 55% of the ink fixing layer II.
% By weight or more, more preferably 60% by weight or more. The PVA polymer of the ink fixing layer II has a molecular weight of 3
It is preferably from 00 to 2000. The PVA-based polymer of the ink fixing layer II has a saponification degree of 60 or more and 8
It is preferably 5 or less. Further, acetylacetoxy-modified gelatin may be partially used in combination. The ink fixing layer II is made of P
It is preferable to include a polymer mordant in addition to the VA-based polymer. The thickness of the ink fixing layer II is preferably 0.5
-20 μm, more preferably 1-20 μm, still more preferably 1.5-15 μm, most preferably 2-10 μm
It is. The ink fixing layer II may be preferably provided on the surface layer side of the ink fixing layer, or may be preferably provided on the support side on the contrary. This is the P
It is determined by the ink absorption performance of the VA-based polymer and the modified gelatin used for the fixed layer. It is preferable to use a polymer mordant in the ink fixing layer II. If necessary, preservatives, latexes, anti-fading agents, tinting dyes, pigments, fluorescent thickeners, surfactants, thickeners and the like can be used. The ink fixing layer is composed of a plurality of layers as necessary. In that case, acetylacetoxy-modified PV
A is preferably used as an ink-receiving polymer in the layer closest to the inner support of the plurality of layers.

An undercoat layer can be provided between the following polyolefin layer provided on the support and the ink fixing layer. The undercoat layer has a function of adjusting the swelling ratio and the curl balance, a function of maintaining the close contact between the ink fixing layer and the polyolefin layer described below, and a function of improving coatability when performing multilayer coating. The undercoat layer is preferably an undercoat layer using gelatin as a binder. Gelatin is preferably present in the 50
% By weight, more preferably at least 55% by weight, even more preferably at least 60% by weight. The undercoat layer preferably contains a fluorescent whitening agent in addition to gelatin. The undercoat layer may have two or more layers. The thickness of each undercoat gelatin layer is preferably 0.5 to 5 μm, more preferably 0.1 to 5 μm.
7 to 3 μm.

The polyolefin layer is a layer provided on a paper support and using polyolefin as a binder. The polyolefin preferably accounts for at least 50% by weight of the layer, more preferably at least 55% by weight, even more preferably at least 60% by weight. Specific examples of the polyolefin include polyethylene, polystyrene, and polybutene. Further, the polyolefin may be an olefin copolymer. Among them, polyethylene is particularly preferred. The polyolefin layer is provided on the support by coating or laminating. The polyolefin layer preferably contains a white pigment or a tinting dye or pigment. As the white pigment, titanium oxide and zinc oxide are preferable,
Anatase type titanium oxide is particularly preferred. In order to improve the dispersibility of anatase type titanium oxide, zinc oxide may be used in combination. When used in combination, the proportion of zinc oxide is preferably 50% by weight or less based on the entire pigment. The content of the white pigment in the polyolefin layer is preferably 5 to 50.
%, More preferably from 10 to 50% by weight, even more preferably from 15 to 30% by weight.

Dyes or pigments are used to color the polyolefin layer and adjust its surface reflectance. The dye or pigment is used at the application temperature of the polyolefin layer (generally 3
(At least 00 ° C.).
Examples of preferred dyes or pigments include cobalt blue, ultramarine and neodymium oxide. The coloring dye or pigment is preferably used in the range of 0.1 to 3% by weight of the white pigment. The surface reflection characteristics of the support can be adjusted by selecting the type of the coloring dye or pigment and adjusting the amount used. The thickness of the polyolefin layer is preferably from 10 to 100 μm, more preferably from 15 to 50 μm, and still more preferably from 20 to 35 μm. It is preferable that the surface of the polyolefin layer is mirror-finished. After performing a surface activation treatment (eg, corona discharge treatment, flame treatment) on the surface of the polyolefin layer, each layer described above may be provided.

As the support, paper or plastic film is preferably used. Paper is preferred over plastic film. In the case of plastic film,
There may be no polyolefin layer. The thickness of the support is 5
0 to 300 μm, preferably 80 to 200 μm
m is more preferable.

In the case of a paper support, it is preferable to provide a polyolefin layer as a back layer also on the back side of the support. The details of the polyolefin back layer are the same as those of the polyolefin layer provided on the front side. The back layer preferably has an antistatic function. Specifically, the surface resistivity of the back layer is preferably 1 × 10 ¹³ Ω · cm or less.

The PVA-based polymer contains at least 50 mol% of a vinyl alcohol unit. Therefore, the degree of saponification of the PVA-based polymer is at least 50 mol%. The saponification degree (proportion of vinyl alcohol units) is preferably from 60 to 90 mol%, more preferably from 65 to 80 mol%. The degree of saponification of polyvinyl alcohol used for ink jet recording paper is a value exceeding 90 mol%. According to the study of the present inventors, the degree of saponification was 90 mol%.
It has been found that the use of the following polyvinyl alcohols can eliminate the granular unevenness of the ink in the image. PVA
The system polymer may contain a repeating unit derived from an ethylenically unsaturated monomer in addition to the vinyl alcohol unit. Examples of ethylenically unsaturated monomers include acrylates, methacrylates, acrylamides, methacrylamides, olefins, vinyl ethers, unsaturated fatty acids (eg, acrylic acid, methacrylic acid, itaconic acid) and vinyl esters (eg, propionic acid) Vinyl, vinyl pivalate). An alkylthio group or an arylthio group may be bonded to the terminal of the PVA-based polymer. The alkylthio group and the arylthio group preferably have 8 or more carbon atoms.

It is particularly preferable that the PVA-based polymer is ordinary polyvinyl alcohol comprising only vinyl alcohol units and vinyl acetate units. The degree of polymerization of the PVA-based polymer used for the ink fixing layer is preferably 300 or more, more preferably 500 to 5,000, and most preferably 500 to 2,000.

The hardener is classified into a low molecular hardener and a high molecular hardener. Examples of low molecular hardeners include aldehyde compounds (eg, formaldehyde, glyoxal, glutaraldehyde), aziridine compounds, isoxazole compounds, epoxy compounds, vinyl sulfone compounds (eg,
1,3,5-triacryloyl-hexahydro-s-triazine, bis (vinylsulfonyl) methyl ether,
N, N′-ethylene-bis (vinylsulfonylacetamide) ethane, N, N′-trimethylene-bis (vinylsulfonylacetamide)), acryloyl compound, carbodiimide compound, triazine compound (eg, 2,4-dichloro) -6-hydroxy-s-triazine), N-methylol compounds (eg, dimethylol urea, methylol dimethylhydantoin), dioxane derivatives (eg, 2,3-dihydroxy dioxane), mucohalic acids (eg, mucochloric acid, mucophenoxychlor) Acid), dialdehyde starch, 1-chloro-6-hydroxytriazinylated gelatin, maleimide compounds, acetylene compounds and methanesulfonic acid esters.

Aziridine compounds are described in PB Report 19921, US Pat. Nos. 2,950,197 and 296.
Nos. 4404, 2983611, and 3271175, JP-B-46-40898, and JP-A-50-50.
There is a description in each publication of 91315. The isoxazole compound is described in US Pat. No. 3,331,609. Epoxy compounds are described in US Pat.
No. 7394, German Patent 1035663, British Patent 10
No. 33518, and JP-B-48-35495. For vinyl sulfone compounds, P
B report 19920, West German patent 1100942,
No. 2337412, No. 2545722, No. 2635
No. 518, No. 2742308, No. 2749260,
UK Patent 1251091; US Patent 3539644
And 3490911. The acryloyl compound is described in US Pat. No. 3,640,720. Regarding carbodiimide compounds, US Pat. Nos. 2,938,892 and 4,043,818;
Nos. 4061499, JP-B-46-3871
No. 5 has a description. For triazine compounds,
The specifications of West German Patents 2410973 and 2553915, U.S. Pat. No. 3,325,287, JP-A-52-127.
No. 22, there is a description.

Examples of the polymer hardener include a polymer having an aldehyde group such as a copolymer of acrolein (described in US Pat. No. 3,396,029) and a polymer having a dichlorotriazine group (see US Pat. No. 3,362,827, Research).・ Disclosure No. 17333 (1
978)), a polymer having an epoxy group (described in US Pat. No. 3,623,878), a polymer having an active vinyl group or a group which is a precursor thereof (Research Disclosure 16725 (1978), US Pat. No. 4,161,407) , JP-A-54-65033,
And the polymer having an active ester group (described in JP-A-56-66841). The amount of the hardener used is preferably 0.1 to 30% by weight of gelatin, and 0.5 to 1% by weight.
More preferably, it is 0% by weight. Since the low-molecular hardener has diffusibility, the other gelatin layers can be hardened only by adding it to the coating solution of one of the gelatin layers. These hardeners are actually hardened not only with gelatin but also with other polymers.

Solid particles having an average particle size of 3 to 100 μm are:
It is added to the surface protective layer as a matting agent. The thickness of the surface protective layer is 0.2 to 2 μm, which is smaller than the average particle size of the solid particles. Therefore, the solid particles may be present from the surface protective layer to a layer therebelow (from the first ink fixing layer to a layer above the polyolefin layer). In other words, solid particles may be present so as to cross the interface between the surface protective layer and the first ink fixing layer. The coating layer provided above the polyolefin layer,
In general, since the solid particles are formed by simultaneous coating, the solid particles can be present in the surface protective layer by adding the solid particles to a coating solution of any of the layers provided above the polyolefin layer. However, it is particularly preferable to add solid particles to the coating solution for the surface protective layer. The average particle size of the solid particles is
10 to 100 μm, preferably 10 to 30 μm
m is more preferable.

The solid particles used as the matting agent can be classified into inorganic particles and organic particles. Materials for the inorganic matting agent include oxides (eg, silicon dioxide, titanium oxide, magnesium oxide, aluminum oxide), alkaline earth metal salts (eg, barium sulfate, calcium carbonate, magnesium sulfate), silver halide (eg, Silver chloride, silver bromide) and glass. Regarding the inorganic matting agent, West German Patent 252
9321, British Patent Nos. 760775 and 126077
No. 2, U.S. Pat. Nos. 1201905 and 2192241
Nos. 3053662, 3062649, 32
No. 57206, No. 3322555, No. 3353958
Nos. 3370951, 3411907, 34
No. 37484, No. 3523022, No. 3615554
Nos. 3635714, 3769020 and 40
No. 21245 and No. 4029504.

The materials of the organic matting agent include starch, cellulose ester (eg, cellulose acetate propionate), cellulose ether (eg, ethyl cellulose).
And synthetic resins. The synthetic resin is preferably water-insoluble or hardly water-soluble. Examples of water-insoluble or poorly water-soluble synthetic resins include poly (meth) acrylates (eg, polyalkyl (meth) acrylate, polyalkoxyalkyl (meth) acrylate, polyglycidyl (meth) acrylate), poly (meth) Includes acrylamide, polyvinyl ester (eg, polyvinyl acetate), polyacrylonitrile, polyolefin (eg, polyethylene), polystyrene, benzoguanamine resin, formaldehyde condensation polymer, epoxy resin, polyamide, polycarbonate, phenolic resin, polyvinyl carbazole and polyvinylidene chloride . A copolymer obtained by combining the above polymer repeating units may be used.

In the case of a copolymer, a small amount of a hydrophilic repeating unit may be contained. Examples of the monomer that forms the hydrophilic repeating unit include acrylic acid, methacrylic acid, α, β-unsaturated dicarboxylic acid, hydroxyalkyl (meth) acrylate, sulfoalkyl (meth) acrylate, and styrene sulfonic acid. As for the organic matting agent, British Patent No. 1055713, US Pat.
939213, 22221873, 226866
No. 2, No. 232,037, No. 2,376,005, No. 2
391181, 701245, 299210
No. 1, No. 3079257, No. 3262782, No. 3
No. 443946, No. 3516832, No. 353934
No. 4, No. 3591379, No. 3754924, No. 3
767448, JP-A-49-106821.
And JP-A-57-14835. Two or more types of solid particles may be used in combination. The amount of the solid particles used is preferably 0.01 to 0.5 g / m ² ,
More preferably, it is 0.02 to 0.3 g / m ² .

The gelatin layer and the polyvinyl alcohol layer have an average particle size of 3 for the purpose of adjusting the ink absorption speed, preventing adhesion, improving the strength, or improving the curl balance.
Solid particles smaller than μm can be added. As the solid particles having an average particle size of less than 3 μm, inorganic pigments are preferably used. Examples of inorganic pigments include silica pigments, alumina pigments, titanium dioxide pigments, zinc oxide pigments, zirconium oxide pigments, mica iron oxide, lead white, lead oxide pigments, cobalt oxide pigments, strontium chromate, molybdenum pigments, smectite, Includes magnesium oxide pigments, calcium oxide pigments, calcium carbonate pigments and mullite. Silica pigments and alumina pigments are preferred. Two or more types of solid particles may be used in combination. Silica pigments include spherical silica and amorphous silica. The silica pigment can be synthesized by a dry method, a wet method, or an airgel method. The surface of the hydrophobic silica particles may be surface-treated with trimethylsilyl groups or silicone. Colloidal silica is particularly preferred. The average particle size of the silica pigment is preferably from 4 to 120 nm, more preferably from 4 to 90 nm. The silica pigment is preferably porous. The average pore size of the porous silica pigment is preferably from 50 to 500 nm. The average pore volume per weight of the porous silica pigment is preferably 0.5 to 3 ml / g.

The alumina pigment includes anhydrous alumina and alumina hydrate. As the crystal form of anhydrous alumina,
α, β, γ, δ, ζ, η, θ, κ, ρ or χ can be used. Alumina hydrate is preferred over anhydrous alumina. Monohydrate or trihydrate can be used as the alumina hydrate. Monohydrates include pseudoboehmite, boehmite and diaspore. Trihydrate includes gibbsite and bayerite. The average particle size of the alumina pigment is preferably from 4 to 300 nm, more preferably from 4 to 200 nm. The alumina pigment is preferably porous. The average pore size of the porous alumina pigment is preferably from 50 to 500 nm. The average pore volume per weight of the porous alumina pigment is preferably 0.3 to 3 ml / g. Alumina hydrate can be synthesized by a sol-gel method in which ammonia is added to an aluminum salt solution for precipitation, or a method in which alkali aluminate is hydrolyzed. Anhydrous alumina can be obtained by dehydrating alumina hydrate by heating. The amount of the inorganic pigment used is a dry weight ratio to the binder (gelatin or PVA-based polymer) of the layer to be added,
The content is preferably 5 to 100% by weight, more preferably 20 to 70% by weight.

A surfactant may be added to the gelatin layer or the polyvinyl alcohol layer. The surfactant functions as a coating aid, an antistatic agent, a slipperiness improver, an emulsifying dispersant, or an antiadhesive. A nonionic surfactant, an anionic surfactant, a cationic surfactant or an amphoteric surfactant can be used. Examples of the nonionic surfactant include steroids (eg, saponin), alkylene oxide derivatives (eg, polyethylene glycol, polyethylene glycol / polypropylene glycol condensate, polyethylene glycol alkyl ether, polyethylene glycol alkyl aryl ether, polyethylene glycol ester, polyethylene) Glycol sorbitan ester, polyalkylene glycol alkylamine,
Polyalkylene glycol alkylamides, polyethylene oxide adducts of silicone), glycidol derivatives (eg, alkenyl succinic acid polyglycerides, alkylphenol polyglycerides) and alkyl esters (eg, fatty acid esters of polyhydric alcohols) are included.

Examples of anionic surfactants include alkyl carboxylate, alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl sulfates, alkyl phosphates, N-acyl-N- Alkyl taurates, sulfosuccinates, sulfoalkyl polyoxyethylene alkyl phenyl ethers and polyoxyethylene alkyl eicosanoates. Examples of cationic surfactants include alkylamine salts, aliphatic or aromatic quaternary ammonium salts, heterocyclic quaternary ammonium salts,
Includes phosphonium salts and sulfonium salts. Examples of amphoteric surfactants include amino acids, aminoalkyl sulfonic acids, aminoalkyl sulfates, aminoalkyl phosphoric acids, alkyl betaines and amine oxides. The amount of the surfactant used is preferably from 0.005 to 0.5 g / m ² , and more preferably from 0.01 to 0.1 g / m ² .

A sliding agent may be added to the image recording medium. Examples of sliding agents include higher alkyl sodium sulfate,
Higher fatty acid higher alcohol esters, carbowax,
Includes higher alkyl phosphates and silicone compounds. The sliding agents that can be used are described in U.S. Patent Nos. 2,882,157, 3,121,060, and 385.
No. 0640, French Patent No. 2180465, British Patent No. 955061, No. 1143118, No. 126372
No. 2, No. 1270578, No. 1,320,564, No. 1
Nos. 320,957, 2,588,765 and 2,739,891
No. 1, No. 3018178, No. 3042522, No. 3
No. 080317, No. 308087, No. 312106
No. 0, 3222178, 329597, 3
No. 489567, No. 3516832, No. 365857
Nos. 3,679,411 and 3,870,521, JP-A-49-5017, and JP-A-51-141623.
Nos. 54-159221 and 56-81841, and Research Disclosure (Research Disclosure).
Disclosure) 13969. The amount of slip agent is preferably 5 to 200 mg / m ^2.

It is preferable to add a preservative (antibacterial agent or antibacterial agent) to the coating layer of the image recording medium, especially to the gelatin layer. Preferably, the preservative is water-soluble.
Examples of water-soluble preservatives include thiazolyl benzimidazole compounds, isothiazolone compounds, chlorophenol compounds, bromophenol compounds, thiocyanate compounds, isothiocyanate compounds, acid azide compounds, diazine compounds, triazine compounds, thiourea compounds, alkyl Guanidine compounds, quaternary ammonium salts, organotin compounds, organozinc compounds, cyclohexylphenol compounds, imidazole compounds, benzimidazole compounds, sulfamide compounds, active halogen compounds (eg, chlorinated sodium isocyanurate), chelating agents, sulfite compounds and Antibiotics (eg, penicillin) are included. For preservatives, refer to LEWest, Water Quality Criterion
ia ”) Phot. Sci. and Eng., Vol. 9, No. 6 (196
5), JP-A-55-111942 and JP-A-57-8542.
No., 57-157244, 58-105145
And No. 59-126533, and in Hiraguchi Hiroshi's "Bactericidal and Fungicide Chemistry" (published by Sankyo Publishing Company in 1982).

A high-boiling organic solvent may be added to the coating layer of the image recording medium. The high-boiling organic solvent functions as a plasticizer, a slipper or an anti-curl agent. Regarding the high boiling organic solvents that can be used, see JP-A-62-24.
No. 5253. As the high boiling point organic solvent, silicone oil (eg, dimethyl silicone oil, modified silicone oil obtained by introducing various organic groups into dimethyl siloxane) may be used. Regarding silicone oils, see JP-A-62-215953 and JP-A-62-15953.
No. 46449 is described in each gazette.

A polymer latex may be added to the coating layer (layer including the back layer) of the image recording medium. When a polymer latex is added, the effects of dimensional stabilization, curl prevention, adhesion prevention or crack prevention can be obtained.
A polymer having a low glass transition temperature (less than 40 ° C.) has an excellent effect of preventing curling or cracking. Further, even if a polymer having a high glass transition temperature is added to the back layer, a curl preventing effect can be obtained. Polymer latex is described in JP-A-62-245258 and JP-A-62-1.
Nos. 100668 and 62-131664.

An anti-fading agent may be added to the image recording medium. As the anti-fading agent, an antioxidant, an ultraviolet absorber or a metal complex can be used. Examples of antioxidants include chroman compounds, coumaran compounds, phenol compounds (eg, hindered phenols), hydroquinone derivatives, hindered amine derivatives, and spiroindane compounds. Regarding antioxidants, see JP-A-61-15.
No. 9644. Examples of UV absorbers include benzotriazole compounds (US Pat.
No. 4), a 4-thiazolidone compound (described in U.S. Pat. No. 3,352,681), a benzophenone compound (described in JP-A-46-2784) and an ultraviolet absorbing polymer (described in JP-A-62-260152). included. For metal complexes, see US Pat. No. 4,241,155.
Nos. 4,245,018 and 4,254,195, JP-A-61-88256, and JP-A-62-174741.
No. 63-199248, JP-A-1-75568
And No. 1-74272.

A fluorescent whitening agent may be added to the image recording medium. Examples of the optical brightener include stilbene compounds, coumarin compounds, biphenyl compounds, benzoxazolyl compounds, naphthalimide compounds, pyrazoline compounds and carbostyril compounds. About the optical brightener,
K. Veenkataraman ed., The Chemistry of Synthetic Dye
s ", Volume 5, Chapter 8 and JP-A-61-143752.

In the image recording medium, an aqueous ink is adhered imagewise to the surface protective layer side, whereby the aqueous ink penetrates into the surface protective layer and the polyvinyl alcohol layer and is fixed in the polyvinyl alcohol layer to form an image. Can be recorded. Specifically, it is used in an image recording method such as an ink jet method, a sublimation type thermal transfer method, and a dye diffusion transfer method, which includes release and reception of a dye. The effect is remarkable when the image recording medium of the present invention is used in the ink jet system. The inkjet system includes a continuous system and an on-demand system. Ink jet heads are classified into a piezo method, a bubble jet method, a thermal jet method, and a method using ultrasonic waves. Recent ink-jet image recording methods include a method of ejecting a large number of low-density inks called photo inks in a small volume, a method of improving image quality by using a plurality of inks having substantially the same hue and different densities, and a method of colorless and transparent. Has been proposed. According to the present invention, a remarkable effect of improving ink absorbency can be obtained in an image recording method using an ink jet printer having a high printing speed.

Further, according to the present invention, a large amount of ink having a low concentration is ejected (ink ejection amount: 10 ml / m ² or more).
Even in an image recording method using an ink jet printer, a remarkable effect of improving ink absorbency can be obtained. Furthermore, the present invention is remarkable in an image recording method using an ink jet printer that ejects ink dots whose ink droplets are 6 pl or less, and in an image recording method that uses an ink jet printer that mixes and ejects ink dots having different ink droplet sizes. The effect of improving ink absorption is obtained.

In order to improve the image quality, recent color ink-jet printers have changed from three colors of yellow, magenta, and cyan to four colors of yellow, magenta, cyan, and black, as well as yellow, dark magenta, light magenta, and dark cyan. The colors of ink are gradually increased, with six colors of light cyan and black. According to the present invention, a remarkable ink absorption improvement effect can be obtained even in a method of recording a color image using many types of inks (especially, six or more colors).

[0062]

The present invention will be described below with reference to examples.
The present invention is not limited to this embodiment. Example 1 (Support) Pulp mixing ratio: LBKP / NBSP = 6/4
High-quality paper (density: 1.053, thickness: 152 μm) was used as a support.

(Formation of Polyolefin Layer) Polyethylene was laminated on both surfaces of the support by extrusion coating at 300 ° C. to form a polyolefin layer, and the following support (1) was obtained. Support (1) Film thickness (μm) Surface subbing layer 0.1 Gelatin Surface polyolefin layer 36.0 Low density polyethylene (density 0.923): 90.2 parts Surface oxidized titanium oxide: 9.8 parts Ultramarine: 0.001 part Pulp layer 152.0 Fine paper (LBKP / NBSP = 6/4, density 1.053, polyolefin layer on the back side 27.0 high-density polyethylene (density 0.955), undercoat layer on the back side 0.1 styrene / acrylate copolymer colloidal silica polystyrene sodium sulfonate 215.2 in total

(Formation of Ink-Fixing Layer and Surface Protective Layer) On the support (1), layers having the following compositions were simultaneously coated to prepare an image receiving paper 101B. The ink fixing layer (1) is provided on the surface undercoat layer of the support (1).

Ink fixing layer (1) Coating amount Polyvinyl alcohol (saponification degree: 82%, average polymerization degree: 500) 0.650 g / m ² Gosefimer Z200 manufactured by Nippon Synthetic Chemical Industry Co., Ltd. 0.120 g / m ² The following compound W-01 (surfactant) 0.050 g / m ² The following compound F-02 (preservative) 0.001 g / m ² provided that the coating liquid viscosity was 15 CPS and the pH was 7.5.

[0066]

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Ink fixing layer (2) Coating amount Polyvinyl alcohol (saponification degree: 82%, average polymerization degree: 500) 2.600 g / m ² Polymer mordant CPM-17 1.700 g / m ^{2 The} above compound W-01 (interface active agent) 0.020 g / m ² above compound F-02 (preservative) 0.001 g / m ^2, however, the coating liquid viscosity 100 cps, pH 8.0

Ink fixing layer (3) Coating amount Polyvinyl alcohol (degree of saponification: 82%, average degree of polymerization: 500) 2.600 g / m ² Polymer mordant CPM-17 1.700 g / m ² Compound W-01 (interface Activator) 0.020 g / m ^{2 The} above compound F-02 (preservative) 0.001 g / m ^{2 The following} compound F-01 (fluorescent brightener) 0.060 g / m ² provided that the viscosity of the coating solution was 100 CPS and the pH was 7. 9

[0069]

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Coating amount of polyvinyl alcohol (degree of saponification: 82%, average degree of polymerization: 2000) 0.130 g / m ² matting agent (PMMA particles, average particle size: 12 μm) 0.250 g / m ² Compound W described above -01 (surfactant) 0.025 g / m ^{2 The following} compound W-02 (surfactant) 0.015 g / m ^{2 The} above compound F-02 (preservative) 0.002 g / m ^{2 The following} compound B-01 ( tinting) 0.001 g / m ² less than the following compound B-02 (tinting) 0.001 g / m ² less than the following compound B-03 (thickener) 0.010 g / m ² the following compound M-01 (matting agent 0.250 g / m ^2, provided that the viscosity of the coating solution is 45 CPS and the pH is 7.5.

[0071]

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[0072]

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The image receiving papers 102B to 111B were prepared in the same manner as the image receiving paper 101B, except that the polyvinyl alcohol in the ink fixing layer (2) and / or (3) of the image receiving paper 101B was replaced with gelatin shown in Table 1. Created. Next, except that the polymer mordant in the ink fixing layers (2) and (3) was removed and the polyvinyl alcohol in the ink fixing layers (2) and / or (3) was replaced with gelatin shown in Table 1, the image receiving method was repeated. Image receiving paper 104 in the same manner as paper 101B
A, 106A and 109A were prepared. Further, the polymer mordant for the ink fixing layers (2) and (3) was supplied to Nippon Shokubai Co., Ltd.
Polyment NK100PM (alkylamine polymer hydrochloride) was replaced with an equivalent weight, and the ink fixing layer (2)
The surfactant W of the following (3) was replaced with W-01.
-03 at 20 mg / m ² and the following surfactant W-04
The use of a 30 mg / m ^2, except that the polyvinyl alcohol in the ink fixing layer (2) and / or (3) was replaced with gelatin described in Table 1, the image receiving paper 104C~111C in the same manner as the receiving sheet 101B It was created. After preparing the image receiving paper, it was left for one week in an environment of 25 ° C. and 50% relative humidity.

[0074]

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[0075]

[Table 1]

Each image receiving paper is 29.5 cm long and 21.0 c wide.
m A4 sheet size. Inkjet color printer (PM750C, Seiko Epson Corporation)
Made, black ink MJIC7 and color ink PMIC1C
A photographic image was printed on each sample. The photographic image was taken with a camera (EOS-10, manufactured by Canon Inc.) using a color reversal film (Provia 1).
00, Fuji Photo Film Co., Ltd.)
It was read by a scanner and converted into a digital signal. In addition, an image captured by a digital still camera (FinePix700, manufactured by Fuji Photo Film Co., Ltd.) was also used. As the design, 20 kinds of landscapes, nature, people, clothing, still life, etc. selected based on the distribution of subjects of general photograph users were used.

The surface of the printed sample was rubbed at regular intervals immediately after output, and the ink absorbability was evaluated by checking whether the ink image could be rubbed. 25 ° C
The test was performed in an environment of -50% RH and 30 ° C.-80% RH. Table 1 shows the results in four stages of x (inferior), Δ (normal), （(excellent), and ◎ (very excellent). Further, the output image was visually evaluated for granular unevenness (beaded unevenness caused by mixing of ink droplets).
Similarly, Table 1 shows the results in three stages of × (poor), Δ (normal), and ○ (excellent).

As is clear from Table 1, the image receiving papers (106A to 111C) of the present invention have good ink absorbency and excellent drying properties.

When the modified gelatin of the present invention was used (10
6B and 109B), compared with the case of using generally used lime-processed gelatin (102B) or acid-processed gelatin (103B), or the case of using conventionally known modified gelatin (104B, 105B). Good ink absorption. In addition, the granular unevenness evaluated at the same time is excellent. It is presumed that the granular unevenness is caused by the coalescence of several ink droplets when drying is slow, and it is considered that the aspect of the present invention is again an indication that the ink absorption performance is good. When the modified gelatin of the present invention was used only in (2) or (3) of the ink fixing layer (107B, 107B)
C, 108B, 108C, 110B, 110C, 111
B, 111C) are used for both (106B, 10C).
6C, 109B, and 109C), the ink absorption performance is slightly inferior to that of the comparative example. Also,
When the modified gelatin of the present invention was used only in the ink fixing layer (2) close to the support, it was observed that the sharpness was good. Further, when the modified gelatin of the present invention was used only for the ink fixing layer (3) near the surface, it was observed that the water resistance was good.

When the polymer mordant of the present invention was used (1)
06B, 109B) are not used (106A, 10B
9A) is excellent in ink absorbency compared to 9A). General formula (1)
The ink absorbency tends to be superior to the case where Nippon Shokubai Co., Ltd.'s Polyment NK100PM (alkylamine polymer hydrochloride), which is a polymer mordant which is not represented in the above, is used (106C to 111C). Although not shown in Table 1, the image receiving paper having the configuration of the present invention was found to have excellent image storability (especially, resistance to light).
That is, when CPM-17 represented by the general formula (1) is used among the polymer mordants of the present invention (106B to 111B).
B) was particularly remarkable.

An image receiving paper 106D having no surface protective layer was prepared for the image receiving paper 106B of the present invention, and the same evaluation was carried out. As a result, the ink absorption was ○ (excellent) and the granular unevenness was ○ (excellent). Was). It can be seen that it is preferable to provide a surface protective layer. The same procedure as for the image receiving paper 106B was performed, except that the surface protective layer was replaced with polyvinyl alcohol (PVA, saponification degree 82%, average polymerization degree 2000) and the adipic acid-modified gelatin used in the present invention was replaced by an equal weight.
When 06E was prepared and evaluated, the ink absorbency was ◎ (excellent) and the granular unevenness was Δ (normal), and the ink absorbency was slightly inferior to 106B. Further, the image receiving paper 106E tended to have higher adhesiveness on the surface after drying as compared with 106B. Therefore, it is more preferable not to use the modified gelatin of the present invention for the surface protective layer.

The same as the image receiving paper 106A except that the surface protective layer was replaced with polyvinyl alcohol (PVA, saponification degree 82%, average polymerization degree 2000) and the polymer mordant CPM-17 used in the present invention was replaced by the same weight. An image receiving paper 106F was produced. Similarly, in the same manner as the image receiving paper 106B except that the surface protective layer was replaced with polyvinyl alcohol (PVA, saponification degree 82%, average polymerization degree 2000) and the polymer mordant CPM-17 used in the present invention was replaced with the same weight. Image receiving paper 106
G was produced. 106 B when comparing the ink absorption capacity
>106A>106G> 106F. Therefore, it is preferable not to use the polymer mordant of the present invention for the surface protective layer. In addition, the water resistance was evaluated by the degree of ink bleeding when the output was immersed in water for 1 minute. As in the case of the ink absorption ability, the case where no polymer mordant was used in the surface protective layer was superior. I understood that.

[0083]

Since the image recording medium of the present invention is constituted by blending gelatin whose amino group has been modified with an alkylcarboxylic acid having 5 or more carbon atoms in the ink absorbing layer, the image recording medium of the present invention has recently been developed. Is preferably used for an improved inkjet printer, and high drying properties can be obtained.

Claims (7)

[Claims] 1. An image recording medium characterized in that a gelatin in which an amino group is modified with an alkyldicarboxylic acid having 5 or more carbon atoms is used for an ink absorbing layer on a support. 2. An image recording medium characterized by using gelatin in which an amino group is modified with an alkyl dicarboxylic acid having 5 or more carbon atoms and at least one polymer mordant in an ink absorbing layer on a support. 3. A method in which two or more ink-absorbing layers are formed on a support, and at least one ink-absorbing layer excluding the outermost surface layer uses gelatin whose amino group is modified with an alkyldicarboxylic acid having 5 or more carbon atoms. An image recording medium characterized by the above-mentioned. 4. A gelatin in which two or more ink absorbing layers are formed on a support, and at least one of the ink absorbing layers excluding the outermost surface layer has an amino group modified with an alkyldicarboxylic acid having 5 or more carbon atoms and at least one kind of gelatin. An image recording medium using a polymer mordant. 5. An image recording medium comprising two or more ink absorbing layers formed on a support, wherein at least one kind of polymer mordant is used in at least one ink absorbing layer excluding the outermost surface layer. 6. The image recording medium according to claim 1, wherein the support is a paper laminated with a polyolefin. 7. An image recording method, wherein an image is recorded by attaching and fixing an aqueous ink imagewise to the image recording medium according to claim 1.