JP2000263928A - Ink jet recording sheet and method for ink jet recording using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet having improved light resistance in the case of ink jet recording the sheet having a porous ink absorption layer on a non-water absorbing support with an aqueous ink containing phthalocyanine aqueous dye. SOLUTION: The ink jet recording sheet comprises a porous ink absdorption layer containing a polyalkylenepolyamine dicyandiamide polycondensate on a non-water absorbing support. It is preferable to use any of a boric acid or its salt, a water soluble polyvalent metal ion, water soluble reducer, a sulfur- containing compound and a hydrophobic antioxidant in addition to the polalkylenepolyamine dicyandiamide polycondensate. The sheet is recorded by an aqueous ink containing a phthalocyanine water soluble cyanine dye and containing 30 wt.% or above of a high boiling point organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet recording sheet, and more particularly to an ink jet recording sheet having a porous ink absorbing layer and improved light fastness.

[0002]

2. Description of the Related Art In recent years, the image quality of ink-jet recording has been rapidly improving, and the image quality is approaching that of photographs. In order to achieve such photographic equivalent image quality (hereinafter referred to as photographic image quality) by ink jet recording, improvements are also being made in the recording paper surface, and recording is performed by providing a fine gap layer on a highly smooth support. Paper is becoming one of the closest to photographic quality because of its high ink absorption and high drying properties.

[0003] The characteristics required for recording paper have been further enhanced in accordance with such high image quality. In particular, ink jet recording in which a support is a non-water-absorbing support and an ink absorbing layer is provided thereon. The paper is preferable because the support maintains high smoothness during ink-jet recording, so that high-quality prints can be obtained.

In ink-jet recording, a water-soluble dye is usually used as a coloring material. However, since the water-soluble dye has high hydrophilicity, it is usually stored for a long period of time under high humidity after recording, or When water droplets adhere to the surface, the dye tends to bleed easily.

In order to solve this problem, it is common practice to add a dye-fixing substance to the ink-receiving layer, and such a dye-fixing agent has a cationic surface. Examples thereof include inorganic pigments (such as alumina fine particles) and cationic polymers having a quaternary ammonium base in the molecule.

However, the fact that the ink-absorbing layer is a void layer means that a high ink-absorbing property and a uniform image without unevenness can be obtained during ink-jet recording, but the porous film has a high oxygen permeability and thus has a high oxygen permeability. Light resistance afterwards tends to deteriorate.

[0007] In particular, when an aqueous ink containing a water-soluble phthalocyanine dye is used as an ink and recorded on an ink jet recording paper having a porous ink absorbing layer on a non-water-absorbing support, light may be emitted depending on the surrounding environmental conditions. It turned out that there was a problem that fading was easily accelerated.

The present inventors have conducted intensive studies on this point. As a result, the photo-fading of the phthalocyanine dye was found to be due to the fact that the ink was a low-evaporating high-boiling organic solvent (diethylene glycol,
Glycerin, etc.) and an ink having a relatively low concentration of a phthalocyanine dye (especially, about 1% by weight or less), and an ink absorbing layer comprising a void layer on a non-water-absorbing support. It has been found that it is easy to occur when recording is performed on the provided ink jet recording paper.

[0009] The light fading depends on the surrounding environment, particularly humidity, and the higher the humidity, the more the fading is promoted. As a result of analysis, it has been found that oxygen is involved in the fading.

Conventionally, it is well known that an antioxidant is effective for light discoloration involving oxygen, and it is also well known that an antioxidant is added to ink jet recording paper. As a result of investigations by the present inventors, the inkjet recording paper provided with a void layer on a non-absorbent support, the light discoloration of an image recorded with a water-soluble phthalocyanine dye, a sufficient effect is not necessarily obtained. Did not.

In particular, most of the compounds which are effective when conventionally added to ink-jet recording paper have a relatively sufficient anti-fading effect at the initial stage, but the effect tends to gradually disappear over time. However, there has been no satisfactory photobleaching involving oxygen for a relatively long period of time.

JP-B-2-35675 describes an ink jet recording paper which uses a polyalkylene polyamine / dicyandiamidammonium salt condensate as a cationic resin and has improved weather resistance. Also, JP-A-9-
No. 254529 describes an ink jet recording paper in which a polyalkylene polyamine / dicyandiamide condensate containing no quaternary ammonium salt structure prevents white background yellowing and discoloration and has improved water resistance.

However, in the ink jet recording paper described in the above publication, only the one using a water-absorbing support as the support is described. As a result of investigations by the present inventors, the polyalkylene polyamine / dicyandiamide-based polycondensate is used in a water-absorbing support (that is, a recording paper in which the support absorbs an ink solvent) to prevent the phthalocyanine dye from fading. Was not observed. This is because in the case of a water-absorbing support such as paper, oxygen passes from the front and back of the ink-absorbing material, and the large pore size of the support makes it easier for oxygen to penetrate, thus providing an anti-fading effect. It is presumed that it cannot be done.

[0014]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to carry out inkjet recording on an inkjet recording paper having a porous ink absorbing layer on a non-water-absorbing support with an aqueous ink containing a phthalocyanine-based aqueous dye. An object of the present invention is to provide an ink jet recording sheet having improved light fastness at the time.

[0015]

The object of the present invention has been attained by the following inventions.

(1) Ink jet recording paper having a porous ink absorbing layer containing a polyalkylene polyamine / dicyandiamide-based polycondensate on a non-water-absorbing support.

(2) An ink jet recording paper having a porous ink absorbing layer containing a polyalkylene polyamine / dicyandiamide polycondensate and boric acid or a salt thereof on a non-water-absorbing support.

(3) Ink jet recording paper having a porous ink absorbing layer containing a polyalkylenepolyamine / dicyandiamide-based polycondensate and a water-soluble polyvalent metal ion on a non-water-absorbing support.

(4) Ink jet recording paper having a porous ink absorbing layer containing a polyalkylene polyamine / dicyandiamide polycondensate and a water-soluble reducing agent on a non-water-absorbing support.

(5) Ink jet recording paper having a porous ink absorbing layer containing a polyalkylene polyamine / dicyandiamide polycondensate and a sulfur-containing compound on a non-water-absorbing support.

(6) An ink jet recording paper having a porous ink absorbing layer containing a polyalkylene polyamine / dicyandiamide-based polycondensate and an emulsified dispersion of a hydrophobic antioxidant on a non-water-absorbing support.

(7) A water-based ink containing a phthalocyanine-based water-soluble cyan dye and a high-boiling organic solvent in an amount of 30% by weight or more, and is an ink jet recording paper according to any one of (1) to (6). Ink jet recording method for recording on a paper.

Hereinafter, the present invention will be described in detail.

The polyalkylene polyamine / dicyandiamide polycondensate used in the present invention is a polycondensate of polyalkylene polyamine and dicyandiamide.

Examples of the polyalkylene polyamine include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, iminobispropylamine and their hydrochlorides, lead sulfate, acetate and the like.

Various polyalkylene polyamine / dicyandiamide polycondensates are commercially available.
For example, Neofix RP-70, Neofix PNF
-70, Neofix E-117 (all manufactured by Nikka Kagaku), Parafix EP (Ohara Palladium Chemical), Diazine Fix 400 (Nissei Chemical),
FASTGEN P-708 (manufactured by Tokai Oil Industries), Jetfix 20 (manufactured by Kuroda Kabushiki Kaisha), Kayafix M (manufactured by Nippon Kayaku), PAP-1 (manufactured by Nippon Senka Kogyo)
And the like. The average molecular weight of the polyalkylene polyamine / dicyandiamide-based polycondensate is 2,000 to 2
00,000 is preferred.

The addition amount of the polyalkylene polyamine / dicyandiamide-based polycondensate is generally 0.01 to 5 g, preferably 0.1 to ² g per 1 m ^{2 of} recording paper.

The ink jet recording paper of the present invention has a porous ink-absorbing layer provided on a non-water-absorbing support. Conventionally, the porous ink-absorbing layer can be formed by a number of methods. In particular, the porous ink absorbing layer is preferably one in which a void layer is formed from an inorganic pigment and a small amount of a hydrophilic binder.

This porous ink absorbing layer is basically composed of inorganic fine particles and a small amount of a hydrophilic binder. Examples of such inorganic fine particles include light calcium carbonate, heavy calcium carbonate, magnesium carbonate, and the like. Kaolin, clay, talc, calcium sulfate, barium sulfate,
Titanium dioxide, zinc oxide, zinc hydroxide, zinc sulfide, zinc carbonate, hydrotalcite, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, alumina, colloidal alumina, pseudoboehmite, hydroxylated Examples include white inorganic pigments such as aluminum, lithopone, zeolite, and magnesium hydroxide.

These inorganic fine particles can be used as primary particles or in a state where secondary aggregated particles are formed. However, from the viewpoint of high gloss and quick absorption, the inorganic fine particles are used in the film. It is preferable to use inorganic fine particles having a size of 0.1 to 0.01 μm.

In the present invention, the inorganic fine particles having an anionic surface include silica synthesized by a gas phase method because of their low cost and low refractive index fine particles capable of obtaining a high reflection density. Colloidal silica is preferred.
As the inorganic fine particles having a cationic surface, fumed silica treated with a cationic surface, colloidal silica treated with a cationic surface, alumina, colloidal alumina, pseudo boehmite, and the like can also be used.

As the hydrophilic binder used in the ink absorbing layer, for example, polyvinyl alcohol, gelatin,
Polyethylene oxide, polyvinylpyrrolidone, polyacrylic acid, polyacrylamide, polyurethane, dextran, dextrin, carrageenan (κ, ι, λ
Etc.), agar, pullulan, water-soluble polyvinyl butyral,
Hydroxyethyl cellulose, carboxymethyl cellulose and the like can be mentioned. Two or more of these hydrophilic polymers can be used in combination.

The hydrophilic polymer preferably used in the present invention is polyvinyl alcohol. The polyvinyl alcohol includes, in addition to ordinary polyvinyl alcohol obtained by hydrolyzing polyvinyl acetate, modified polyvinyl alcohol such as polyvinyl alcohol having a cation-modified terminal or anion-modified polyvinyl alcohol having an anionic group. .

As the polyvinyl alcohol obtained by hydrolyzing vinyl acetate, those having an average degree of polymerization of 1,000 or more are preferably used.
0 is preferred. The saponification degree is preferably from 70 to 100%, particularly preferably from 80 to 99.5%.

As the cation-modified polyvinyl alcohol, for example, a tertiary amino group or a quaternary ammonium group as described in JP-A No. 61-10483 can be added to the main chain or side chain of the polyvinyl alcohol. Which is obtained by saponifying a copolymer of an ethylenically unsaturated monomer having a cationic group and vinyl acetate.

Examples of the ethylenically unsaturated monomer having a cationic group include trimethyl. (2-acrylamido-2,2-dimethylethyl) ammonium chloride and trimethyl. (3-acrylamido-3,3-dimethylpropyl). Ammonium chloride, N-vinylimidazole, N-vinyl-2-methylimidazole, N
-(3-dimethylaminopropyl) methacrylamide,
Examples include hydroxylethyl trimethylammonium chloride, trimethyl (methacrylamidopropyl) ammonium chloride, N- (1,1-dimethyl-3-dimethylaminopropyl) acrylamide, and the like.

The proportion of the cation-modified group-containing monomer in the cation-modified polyvinyl alcohol is 0.1 to 10 mol%, preferably 0.2 to 5 mol%, based on vinyl acetate.

The anion-modified polyvinyl alcohol is, for example, a polyvinyl alcohol having an anionic group as described in JP-A No. 1-2060888 or JP-A-61-2.
Copolymers of vinyl alcohol and a vinyl compound having a water-soluble group as described in JP-A Nos. 37681 and 63-307979, and modifications having a water-soluble group as described in JP-A-7-285265 Polyvinyl alcohol.

Examples of the nonionic modified polyvinyl alcohol include polyvinyl alcohol derivatives in which a polyalkylene oxide group is added to a part of vinyl alcohol, as described in JP-A-7-9758.
And a block copolymer of a vinyl compound having a hydrophobic group and vinyl alcohol described in JP-A-25795.

Two or more kinds of polyvinyl alcohols such as different degrees of polymerization and different types of modification can be used in combination.

The amount of the inorganic fine particles used in the ink absorbing layer depends on the required ink absorbing capacity, the porosity of the void layer,
Although it largely depends on the kind of the inorganic fine particles and the kind of the hydrophilic binder, generally, about 5 to 30 per m ² of the recording paper
g, preferably 10 to 25 g.

The ratio of the inorganic fine particles to the hydrophilic binder used in the ink absorbing layer is approximately 2: 1 to 2 by weight.
0: 1, particularly preferably 3: 1 to 10: 1.

The non-water-absorbing support used for the recording paper of the present invention includes a transparent support and an opaque support.

Examples of the transparent support include films made of polyester resin, diacetate resin, triacetate resin, acrylic resin, polycarbonate resin, polyvinyl chloride resin, polyimide resin, cellophane, celluloid, and the like. Among them, those having the property of resisting radiant heat when used as OHP are preferable, and polyethylene terephthalate is particularly preferable. The thickness of such a transparent support is about 10 to 200 μm
Is preferred.

Examples of the opaque support include resin-coated paper (so-called RC paper) having a polyolefin resin-coated layer obtained by adding a white pigment or the like to at least one of base papers.
A so-called white pet obtained by adding a white pigment such as barium sulfate to polyethylene terephthalate is preferred.

Prior to the application of the ink receiving layer, it is preferable to subject the support to a corona discharge treatment or a subbing treatment for the purpose of increasing the adhesive strength between the various supports and the ink image receiving layer. Further, the recording sheet of the present invention is not necessarily colorless, and may be a colored recording sheet.

In the ink jet recording paper of the present invention, it is preferable to use a paper support in which both sides of the base paper support are laminated with polyethylene, since the recorded image is close to photographic quality, and a high quality image can be obtained at low cost. preferable.
A paper support laminated with such polyethylene will be described below.

The base paper used for the paper support is made of wood pulp as a main raw material, and if necessary, in addition to wood pulp, using synthetic pulp such as polypropylene or synthetic fiber such as nylon or polyester. As wood pulp, LBKP, LBSP, NBKP, NBSP, LD
Any of P, NDP, LUKP, and NUKP can be used, but LBKP, NBSP, and LBS containing a large amount of short fibers
It is preferable to use more P, NDP, and LDP.
However, the ratio of LBSP and / or LDP is preferably 1070% by weight.

As the pulp, a chemical pulp containing a small amount of impurities (sulfate pulp or sulfite pulp) is preferably used, and pulp having improved whiteness by a bleaching treatment is also useful.

In the base paper, sizing agents such as higher fatty acids and alkyl ketene dimers, white pigments such as calcium carbonate, talc and titanium oxide, paper strength agents such as starch, polyacrylamide and polyvinyl alcohol, fluorescent whitening agents, Water retention agents such as polyethylene glycols, dispersants, and softening agents such as quaternary ammonium can be appropriately added.

The freeness of pulp used for papermaking is determined by CSF
The fiber length after beating is preferably 30 to 50 cc, and the sum of the 24 mesh residual weight% and the 42 mesh residual weight% defined in JIS-P-8207 is 30 to 50 cc.
70% is preferred. The weight percentage of the remaining 24 mesh is 2
It is preferably 0% by weight or less.

The basis weight of the base paper is preferably 30 to 250 g,
Particularly, 50 to 200 g is preferable. Base paper thickness is 40-2
50 μm is preferred.

The base paper may be calendered at the papermaking stage or after the papermaking to provide high smoothness. The base paper density is generally 0.7 to 1.2 g / m ² (JIS-P-8118). Further, the rigidity of the base paper is preferably from 20 to 200 g under the conditions specified in JIS-P-8143.

A surface sizing agent may be applied to the surface of the base paper. As the surface sizing agent, the same sizing agents as those which can be added to the base paper can be used.

The pH of the base paper is preferably 5 to 9 when measured by the hot water extraction method specified in JIS-P-8113.

The polyethylene covering the front and back surfaces of the base paper is mainly low-density polyethylene (LDPE) and / or high-density polyethylene (HDPE), but other LLDPE, polypropylene and the like can also be partially used. .

In particular, the polyethylene layer on the ink receiving layer side is preferably a layer obtained by adding rutile or anatase type titanium oxide to polyethylene to improve opacity and whiteness as widely used in photographic printing paper. preferable. The content of titanium oxide is about 3 to 20% by weight, preferably 4 to 13% by weight, based on polyethylene.

The polyethylene-coated paper can be used as glossy paper, or when polyethylene is melted, extruded and coated on the surface of a base paper, a so-called embossing treatment is performed to obtain a matte which can be obtained with ordinary photographic printing paper. Those having a surface or silk surface can also be used in the present invention.

The amount of polyethylene used on the front and back of the base paper is selected so as to optimize the curl at low and high humidity after the ink receiving layer and the back layer are provided. The layer has a thickness of 20 to 40 μm, and the back layer has a thickness of 10 to 30 μm.

Further, the above-mentioned polyethylene-coated paper support comprises:
It preferably has the following characteristics.

1) Tensile strength: JIS-P-8113
2-30 kg in the vertical direction and 1 in the horizontal direction with the strength specified by
~ 20kg.

2) Tear strength: JIS-P-8116
10 to 200 g in the vertical direction and 2 in the horizontal direction
0-200 g.

3) Elasticity: compressive elastic modulus ≧ 10 ³ kgf / c
m ² .

4) Surface Beck smoothness: JIS-P-811
20 seconds or more (gloss surface) under the conditions specified in 9. Less than this is also possible for molded products.

5) Opacity: Under the measurement conditions of linear light incidence / diffuse light transmission conditions, the transmittance of light in the visible region is 20% or less (particularly 15% or less).

In the recording paper of the present invention, the light resistance of the phthalocyanine dye is improved by adding a polyalkylene polyamine / dicyandiamide polycondensate to the ink absorbing layer on the non-absorbing support. The effect can be maintained by adding an emulsified dispersion of a water-soluble reducing agent, a sulfur-containing compound or a hydrophobic antioxidant. The effect of maintaining the anti-fading effect is particularly significant when stored at high humidity.

As the water-soluble reducing agent, JP-A-8-300
No. 807, No. 8-150773, No. 8-108617
Nos. 9-267544 and the like, for example, sulfites, nitrites, phosphites, thiosulfates, ascorbic acid or salts thereof, and hydroxylamine derivatives (N, N
-Diethylhydroxylamine, N, N-disulfoethylhydroxylamine sodium salt, N-hydroxyphthalimide, N, N-dicarboxyethylhydroxylamine sodium salt), glucose and the like.

Examples of the sulfur-containing compound include those described in JP-A-61-17.
Nos. 7279, 61-163886 and 64-364
No. 79, JP-A-7-314883 and JP-A-7-31488
No. 2, No. 1-115677, etc., for example, thiocyanate, thiourea, 2-mercaptobenzimidazole, 2-mercaptobenzthiazole, 2-mercaptobenzoxazole, 5-mercapto-1-methyltetrazole, 2,5-dimercapto-1,3,4
-Triazole, 2,4,6-trimercaptocyanuric acid, thiosalicylic acid, thiouracil, 1,2-bis (2
-Hydroxyethylthio) ethane and the like.

Examples of the hydrophobic antioxidant include JP-A-57-74192 and JP-A-57-87989, and
Known antioxidants such as those described in JP-A-115667 and JP-A-3-13376 can be used. Particularly preferred antioxidants are those in which at least one of the ortho positions of the hydroxyl group is 3
So-called hindered phenolic antioxidant substituted with a secondary alkyl group, piperidine-based antioxidant in which two carbon atoms linked to a nitrogen atom are both substituted with an alkyl group (so-called hindered amines), phenols or polyphenols It is an antioxidant in which at least one hydroxyl group of hydroxybenzenes is etherified with an alkyl group.

The above-mentioned hydrophobic antioxidant is preferably used in combination with a hydrophobic high-boiling point organic solvent (such as di-2-ethylhexyl phthalate, di-i-decyl phthalate, tricresyl phosphate and tri-2-ethylhexyl phosphate). It is added in a state of being emulsified and dispersed in a hydrophilic binder. When the hydrophobic antioxidant is dissolved in an organic solvent such as acetone or methanol and added, or added by a wet pulverization method, the effect of preventing fading is small.

The ratio of the hydrophobic antioxidant to the high-boiling organic solvent is generally from 1: 5 to 10: 1 by weight.

The amount of the compound that maintains the fading prevention effect of the polyalkylenepolyamine / dicyandiamide-based polycondensate is generally about 0.01 to 10 per m ^{2 of} recording paper.
g, preferably 0.1 to 2 g.

In order to impart water resistance to the porous ink-absorbing layer, generally, alumina fine particles having a cationic surface are used as inorganic pigments, or silica fine particles having an anionic surface are mixed with quaternary silica. A cationic polymer having an ammonium base is used in combination. However, when the polyalkylene polyamine / dicyandiamide-based polycondensate of the present invention is added to such an ink absorbing layer, bleeding tends to be deteriorated after printing.

If the ink absorbing layer contains boric acid or a salt thereof or a water-soluble polyvalent metal ion in order to prevent the deterioration of the bleeding, the bleeding is improved.

The boric acid or a salt thereof refers to an oxyacid having a boron atom as a central atom and a salt thereof. Specifically, orthoboric acid, diboric acid, metaboric acid, tetraboric acid, pentaboric acid,
Includes octaboric acid and their salts.

The boric acid or a salt thereof can be used for recording paper 1 m
^It is used in an amount of 0.05 to ² g, preferably 0.1 to 1 g per ² pieces.

The water-soluble polyvalent metal ions include
It is a tetravalent polyvalent metal ion, specifically, Ca ²⁺ , Mg
²⁺ , Zn ²⁺ , Cu ²⁺ , Fe ³⁺ , Ni ²⁺ , Co ²⁺ , Al ³⁺
And the like, in particular, Ca ²⁺ , Mg ²⁺ , Zn ²⁺ , Al
³⁺ is preferred.

The amount of such polyvalent metal ions added is generally about 0.1 to 10 mmol per 1 m ^{2 of} recording paper.
When the amount is less than 0.1 mmol, the effect is small. When the amount exceeds 10 mmol, aggregation of the dye is promoted, and a bronzing phenomenon on the surface is easily caused. Particularly preferred is 0.
2 to 2 mmol.

[0079] In addition, K ^+, Na ^+, also the content of monovalent cations NH ₄ ^+, etc., in an ink absorbing layer containing a polyalkylene polyamine dicyandiamide polycondensate care must be taken.

The amount of the monovalent cation has a relatively small effect on ink absorption, bleeding and discoloration after printing, but when added in a large amount, bleeding after printing tends to be deteriorated. The preferable addition amount is about 0.1 per 1 m ^{2 of} recording paper.
It is at most 1 mmol, particularly preferably at most 0.05 mmol. The lower limit is not particularly limited.

It is preferable that the ink absorbing layer of the recording paper of the present invention further contains a water-soluble polyvalent metal ion.

Various additives other than those described above can be added to the ink absorbing layer and other optional layers of the ink jet recording paper of the present invention.

For example, polystyrene, polyacrylates, polymethacrylates, polyacrylamides, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, or copolymers thereof, urea resins, melamine resins, etc. Organic latex fine particles;
Various cationic or nonionic surfactants;
74193, 57-87988 and 62-26
UV absorber described in No. 1476; JP-A-57-741
No. 92, No. 57-87989, No. 60-72785
Discoloration inhibitors described in JP-A Nos. 61-146591, 61-95091 and 3-13376; JP-A-59-42993 and 59-52689.
Fluorescent brighteners described in JP-A Nos. 62-280069, 62-242871 and JP-A-4-219266; sulfuric acid, phosphoric acid, citric acid, sodium hydroxide, potassium hydroxide, potassium carbonate, etc. PH adjuster; known additives such as an antifoaming agent, a preservative, a thickener, an antistatic agent, and a matting agent.

When the surface of the inorganic fine particles is anionic, a cationic polymer having a quaternary ammonium base is added to the ink absorbing layer in order to improve the water resistance of the dye and the bleeding after printing. Is preferably added.

As such a cationic polymer, known polymers can be used.
Nos. 0-193776, 10-217601, and 11
Those described in No. -20300 are preferred.

The porous ink absorbing layer may be composed of two or more layers. In this case, the constitutions of the ink absorbing layers may be the same or different.

The method for applying various hydrophilic layers, which are appropriately provided as necessary, such as the ink absorbing layer and the undercoat layer of the recording paper of the present invention, to the support may be appropriately selected from known methods. Can be. A preferred method is obtained by applying and drying a coating solution constituting each layer on a support. In this case, two or more layers can be coated simultaneously, and in particular, simultaneous coating in which all the hydrophilic binder layers need only be applied once is preferable.

Examples of the coating method include a roll coating method, a rod bar coating method, an air knife coating method, a spray coating method, a curtain coating method and an extrusion coating method using a hopper described in US Pat. No. 2,681,294. It is preferably used.

When recording an image using the ink jet recording paper of the present invention, a recording method using an aqueous ink is preferably used.

The aqueous ink referred to in the present invention is a recording liquid comprising the following colorant, liquid medium, and other additives.

As the coloring agent, a water-soluble dye or a water-dispersible pigment such as a direct dye, an acid dye, a basic dye, a reactive dye or a food coloring known in the ink jet can be used.
Among them, those having a particularly large effect are those containing a phthalocyanine dye as a cyan dye. Phthalocyanine dyes are particularly widely known among cyan dyes,
And is used.

Examples of the solvent for the aqueous ink include water and various water-soluble organic solvents, for example, alcohols such as methyl alcohol, i-propyl alcohol, butyl alcohol, t-butyl alcohol, and i-butyl alcohol; dimethylformamide, dimethylacetamide Amides such as acetone, ketone or ketone alcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol, propylene glycol, butylene glycol;
Polyhydric alcohols such as triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol, glycerin, triethanolamine; ethylene glycol methyl ether, diethylene glycol methyl (or ethyl) ether, triethylene And lower alkyl ethers of polyhydric alcohols such as glycol monobutyl ether.

Among these many water-soluble organic solvents,
Polyhydric alcohols such as diethylene glycol, triethanolamine and glycerin, and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monobutyl ether are preferred.

Other additives for the water-based ink include, for example, a pH adjuster, a metal sequestering agent, a fungicide, a viscosity adjuster, a surface tension adjuster, a wetting agent, a surfactant and a rust inhibitor.

The aqueous ink liquid is 25 to 60 dyn / 20 ° C. in order to improve the wettability on the recording paper.
cm, preferably in the range of 30 to 50 dyn / cm.

[0096]

EXAMPLES The present invention will be described below with reference to examples, but embodiments of the present invention are not limited to these. In addition, "%" in an Example shows absolute dry weight% unless there is particular notice.

Example 1 (Preparation of Silica Dispersion-1) 125 kg of fumed silica (A300 manufactured by Nippon Aerosil Co., Ltd.) having an average primary particle size of about 0.007 μm was prepared by Mitamura Riken Kogyo Co., Ltd. Using a jet stream inductor mixer TDS, the mixture was suction-dispersed at room temperature in 620 liters of pure water adjusted to pH = 3.0 with nitric acid, and then the total amount was made up to 694 liters with pure water.

(Preparation of Silica Dispersion-2) 1.63 kg of the following cationic polymer (P-1) and 2.2 parts of ethanol
Liter, an aqueous solution (pH = 3.0) containing 1.5 liter of propanol and 18 liter of silica dispersion-1.
Was added with stirring, and then 1 g of an antifoaming agent (SN381: manufactured by San Nopco) was added.

This mixture was dispersed with a high-pressure homogenizer manufactured by Sanwa Kogyo Co., Ltd., and the total amount was made up to 97 liters with pure water.

[0100]

Embedded image

(Preparation of Coating Liquid) The following coating liquid was prepared using the above silica dispersion liquid-2.

To 650 ml of the silica dispersion liquid 2 was added 40 ° C.
The following additives were sequentially mixed while stirring.

6 ml of a 10% aqueous solution of polyvinyl alcohol (manufactured by Kuraray Industries: PVA203) 5 ml of a 5% aqueous solution of polyvinyl alcohol (manufactured by Kuraray Industries: PVA235) 240 ml A polyalkylenepolyamine / dicyandiamide-based polycondensate shown in Table 1 (Addition amount per 1 m ^{2 of} paper) 10% aqueous solution of acid-treated gelatin 24 ml Pure water is used to make the total volume 1000 ml.

<Preparation of Inkjet Recording Paper> Thickness 1
Polyethylene-coated paper in which both sides of a 70 g / m ² base paper are coated with polyethylene (containing 8% by weight of anatase type titanium oxide in the polyethylene on the ink receiving layer side; 0.05 g / m ² gelatin undercoating on the ink receiving layer side) Layer on the opposite side, containing 0.2 g / m ² of a latex polymer having a Tg of about 80 ° C. as a back layer) so as to have a wet film thickness of 170 μm and cooling to about 7 ° C. once. After that, drying was performed by blowing warm air at 20 to 65 ° C. to prepare recording papers 1 to 5.

Comparative Example 1 Recording paper-1A to 5A were produced in the same manner as in Example 1 except that the support used in Example 1 was changed to a water-absorbing cast-coated paper having a thickness of 150 μm.

Each of the obtained recording sheets was evaluated for light fastness.

<< Lightfastness >> Each recording paper was prepared by using an aqueous ink containing 2% by weight of a phthalocyanine-based cyan dye, 6% by weight of glycerin and 20% by weight of ethylene glycol, and changing the discharge amount stepwise by an ink jet printer. Printed on.

The obtained printed image was subjected to a fluorescent lamp fading tester for 20 days under two conditions of 30 ° C./50% RH and 30 ° C./75% RH under the condition that the printing surface was about 2000 Lux. For 80 days.

The reflection density after irradiation with the fluorescent lamp at the point where the reflection density before irradiation with the fluorescent lamp becomes 1.0 was used as a measure of light fastness as a dye residual ratio.

Table 1 shows the obtained results.

[0111]

[Table 1]

From the results in Table 1, it can be seen that the recording papers 1 to 5 of the present invention using the non-water-absorbing support were more light-fast than the comparative recording papers 1A to 5A using the water-absorbing support. It is understood that the discoloration is further improved by adding the polyalkylene polyamine / dicyandiamide-based polycondensate of the present invention to recording paper having a non-water-absorbing support.

On the other hand, when a water-absorbing support is used, even if a polyalkylene polyamine / dicyandiamide polycondensate is added, the light resistance is hardly improved.

Example 2 Recording papers 21 to 29 obtained by adding a water-soluble polyvalent metal compound shown in Table 2 to recording paper-2 produced in Example 1 were produced in the same manner. Note that recording papers 11 and 12 in which only a water-soluble polyvalent metal compound was added to recording paper-1 were also prepared.

The light fastness of each of the obtained recording sheets was evaluated in the same manner as in Example 1, and the bleeding after printing was evaluated as follows. Table 2 shows the results.

<< Bleed >> A cyan line (line width ≒ 300 μm) was printed with the ink used in the light fastness test and the ink jet printer.
m) was printed and stored at 40 ° C. and 80% RH for 5 days.

The line width before and after storage was measured with a microdensitometer (the width of the portion where the reflection density was 50% of the maximum density was taken as the line width), and the bleeding was determined according to the following values. The smaller the value, the better the bleeding.

{Line width after storage (μm) −line width before storage (μm)} / line width before storage (μm)

[0119]

[Table 2]

From the results shown in Table 2, it is found that the addition of the polyalkylene polyamine / dicyandiamide polycondensate slightly deteriorates bleeding (2 for recording paper-1). In addition, the recording papers 11 and 12 show deterioration in light resistance during long-term storage.

It is considered that the dyeing property to the cationic polymer having higher dye fixing property was inhibited by the polyalkylene polyamine / dicyandiamide-based polycondensate. It can be seen that all of the papers 21 to 28 have improved bleeding without adversely affecting the light resistance.

It can be seen that the recording paper-29 to which a salt other than a polyvalent metal salt was added could not obtain the effect of improving bleeding.
Incidentally, the recording paper-25 was slightly bronzed on the surface.

Example 3 The following silica dispersion-3 containing borate was prepared in the same manner as the silica dispersion-2 prepared in Example 1.

(Preparation of Silica Dispersion-3) Cationic polymer (P-1: supra) 1.63 kg, ethanol 2.2
Liter, an aqueous solution (pH = 3.0) containing 1.5 liter of propanol and 18 liter of silica dispersion-1.
Was added with stirring, then 7.0 liter of an aqueous solution containing 260 g of boric acid and 230 g of borax was added, and 1 g of an antifoaming agent (SN381: supra) was added.

This mixed solution was dispersed with a high-pressure homogenizer manufactured by Sanwa Kogyo Co., Ltd., and the total amount was adjusted to 97 liters with pure water.

(Preparation of Coating Solution) The above silica dispersion-3
Was used to prepare the following coating liquid to which the polyalkylene polyamine / dicyandiamide-based polycondensate used in Example 1 was added in an amount shown in Table 3.

To 650 ml of the silica dispersion liquid 3 was added 40 ° C.
The following additives were sequentially mixed while stirring.

[0128] Polyvinyl alcohol: 10% aqueous solution 6ml polyvinyl alcohol (PVA 203 supra) (PVA235: supra) 5% aqueous solution of 260ml Table polyalkylene polyamine dicyandiamide polycondensates (numerical values shown in 3 recording sheet 1 m ² per The total amount is adjusted to 1000 ml with 24 ml of pure water and a 10% aqueous solution of acid-treated gelatin.

<Preparation of Recording Paper> In the same manner as in Example 1, recording papers 31 to 35 containing borate were prepared corresponding to recording papers 1 to 5 prepared in Example 1. However, RC base paper was used for the support.

Using the obtained recording paper, the light resistance and the bleeding were evaluated in the same manner as in Examples 1 and 2, and the results shown in Table 3 were obtained.

[0131]

[Table 3]

From the results shown in Table 3, it can be seen that the recording paper to which the borate was added has improved the bleeding due to the polyalkylene polyamine / dicyandiamide polycondensate without adversely affecting the light resistance.

Example 4 (Preparation of silica dispersion-4) In silica dispersion-3, the cationic polymer was changed from P-1 to P-2.
A silica dispersion-4 was prepared in the same manner as the silica dispersion-2 except that boric acid and borax were changed to 200 g and 210 g, respectively.

[0134]

Embedded image

(Preparation of Titanium Oxide Dispersion) Titanium oxide W
-10 (manufactured by Ishihara Sangyo Co., Ltd.), 25 kg, 1 liter of 5% sodium tripolyphosphate aqueous solution, 10 liters of polyvinyl alcohol (PVA235), antifoaming agent (SN381)
The solution was added to 75 liters of an aqueous solution containing 3 ml and 1.5 kg of the cationic polymer (P-1), dispersed by a high-pressure homogenizer, and the total amount was made up to 100 liters with pure water to obtain a titanium oxide dispersion.

(Preparation of Oil Dispersion-1) 34 kg of di-i-decyl phthalate and 45 liters of ethyl acetate were mixed with 11 kg of acid-treated gelatin and 10 kg of katin polymer (P-1).
The mixture was added to 270 liters of an aqueous solution containing 10 kg and 11 kg of saponin at 50 ° C., and emulsified and dispersed by a high-pressure homogenizer.

(Preparation of Coating Solutions) The following four coating solutions were prepared.

Coating solution for first layer (lowest layer) Silica dispersion-3 600 ml 10% aqueous solution of polyvinyl alcohol (PVA203) 6.1 ml 5% aqueous solution of polyvinyl alcohol (PVA235) 260 ml Oil dispersion-1 29 ml Titanium oxide dispersion 33 ml Cationic latex (AE-803: Showa Kogaku Kogyo Co., Ltd.) 36 ml Polyalkylenepolyamine / dicyandiamide-based polycondensate shown in Table 4 (numerical values indicate the amount added per 1 m ² of recording paper) Finish (coating solution pH = 4.5).

Second layer coating liquid Silica dispersion-3 670 ml Polyvinyl alcohol (PVA203) 10% aqueous solution 6.1 ml Polyvinyl alcohol (PVA235) 5% aqueous solution 240 ml Oil dispersion-1 41 ml Cationic latex (AE-803: before) Ex) 11 ml Polyalkylenepolyamine / dicyandiamide-based polycondensate shown in Table 4 (numerical values indicate the amount added per 1 m ² of recording paper) The total amount is finished to 1000 ml with pure water (coating solution pH = 4.5).

Third Layer Coating Solution Silica Dispersion-4 630 ml Polyvinyl alcohol (PVA203) 10% aqueous solution 6.1 ml Polyvinyl alcohol (PVA235) 5% aqueous solution 260 ml Oil dispersion-1 41 ml Cationic latex (AE-803: before) Ex) 11 ml The total volume is adjusted to 1000 ml with pure water (coating solution pH = 4.5).

Coating solution for fourth layer (top layer) Silica dispersion-4 610 ml 10% aqueous solution of polyvinyl alcohol (PVA203) 6.1 ml 5% aqueous solution of polyvinyl alcohol (PVA235) 270 ml Silicon oil dispersion (BY-22-839: (Toray Dow Corning Silicone Co., Ltd.) 16 ml Saponin 50% aqueous solution 2 ml Make up the total amount to 1000 ml with pure water (coating solution pH = 4.5).

<Preparation of Recording Paper> The coating liquids of the first to fourth layers were simultaneously coated on the support used in Example 1 so that the wet film thickness of each layer was 45 μm. Recording papers 41 to 45 and 41A to 45A were produced.

Using these recording sheets, the light resistance was evaluated in the same manner as in Example 1, and the results shown in Table 4 were obtained.

[0144]

[Table 4]

From the results shown in Table 4, it can be seen that the ink absorbing layer has a multi-layer structure, and the polyalkylene polyamine / dicyandiamide-based polycondensate is added only to the two layers close to the support. It can be seen that the effect of preventing fading is obtained.

Example 5 When preparing the oil dispersion-1 of Example 4, di-i-
An oil dispersion was prepared in the same manner as in Oil Dispersion-1 except that the hydrophobic antioxidants shown in Table 5 were added together with decyl phthalate and ethyl acetate. In the table, numerical values indicate the total amount added per 1 m ² of recording paper.

Recording papers 41 and 4 produced in Example 4
Recording papers-41 and 42 except that the oil dispersions of the first to third layers of No. 2 were changed to the oil dispersions prepared as described above.
Recording papers 51 to 55 (containing a polyalkylene polyamine / dicyandiamide polycondensate corresponding to recording paper -42), 51B to 55B (recording paper -41)
(No polyalkylene polyamine / dicyandiamide-based polycondensate was contained).

The light fastness of these recording sheets was evaluated in the same manner as in Example 1, and the results shown in Table 5 were obtained.

[0149]

[Table 5]

[0150]

Embedded image

From the results shown in Table 5, it can be seen that the effect of preventing the fading of the polyalkylenepolyamine / dicyandiamide-based polycondensate is maintained for a long time by adding the hydrophobic antioxidant. In particular, it can be seen that this effect is high when stored at high humidity.

On the other hand, when a polyalkylenepolyamine / dicyandiamide-based polycondensate is not contained, a high anti-fading effect cannot be obtained even by the addition of the hydrophobic antioxidant.

Example 6 Recording sheets -42 and 41 of Example 4 were prepared by adding various additives shown in Table 6 to recording sheets -61 to 66 and-.
61B-66B were produced like Example-4.

The above additives were added to the first layer coating solution as water or methanol solutions, respectively. The addition amounts shown in Table 6 are the addition amounts per 1 m ² of the recording paper.

The recording sheets 61 to 66 are the same as the recording sheet 42.
The recording papers -61B to 66B do not contain a polyalkylenepolyamine-dicyandiamide-based polycondensate corresponding to recording paper -41.

The light resistance of the recording paper obtained in the same manner as in Example 4 was evaluated, and the results shown in Table 6 were obtained.

[0157]

[Table 6]

From the results shown in Table 6, the water-soluble reducing agent was used in combination with the polyalkylene polyamine / dicyandiamide-based polycondensate (Recording Paper-61 to 63), and the sulfur-containing compound was used in combination (Recording Paper-64). -66), it can be seen that the light-fading property is improved over a long period of time.

On the other hand, when the polyalkylene polyamine / dicyandiamide-based polycondensate is not contained, the effect of preventing fading of the phthalocyanine-based cyan dye is insufficient with only the above additives.

[0160]

As described above, according to the present invention, light resistance is dramatically improved by including a polyalkylene polyamine / dicyandiamide-based polycondensate in a porous ink absorbing layer on a non-water-absorbing support. can do.

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 2C056 EA13 FC06 2H086 BA15 BA31 BA34 BA38 BA54 BA56 BA62

Claims (7)

[Claims] 1. An ink-jet recording sheet comprising a non-water-absorbing support and a porous ink-absorbing layer containing a polyalkylenepolyamine / dicyandiamide-based polycondensate. 2. An ink-jet recording sheet comprising a non-water-absorbing support and a porous ink-absorbing layer containing a polyalkylenepolyamine / dicyandiamide-based polycondensate and boric acid or a salt thereof. 3. An ink-jet recording paper comprising a non-water-absorbing support and a porous ink-absorbing layer containing a polyalkylenepolyamine / dicyandiamide-based polycondensate and a water-soluble polyvalent metal ion. 4. An ink-jet recording sheet comprising a non-water-absorbing support and a porous ink-absorbing layer containing a polyalkylenepolyamine / dicyandiamide-based polycondensate and a water-soluble reducing agent. 5. An ink-jet recording paper comprising a non-water-absorbing support and a porous ink-absorbing layer containing a polyalkylenepolyamine / dicyandiamide-based polycondensate and a sulfur-containing compound. 6. An ink-jet recording comprising a non-water-absorbing support and a porous ink-absorbing layer containing an emulsified dispersion of a polyalkylenepolyamine / dicyandiamide-based polycondensate and a hydrophobic antioxidant. Paper. 7. An ink-jet recording sheet according to claim 1, which is an aqueous ink containing a phthalocyanine-based water-soluble cyan dye and a high-boiling organic solvent in an amount of 30% by weight or more. An inkjet recording method characterized by the above-mentioned.