JP2003276310A - Ink-jet recording sheet for non-aqueous pigment ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink-jet recording sheet for a non-aqueous pigment ink which has an ink receiving layer on an ink-solvent absorbing support and a high image density, is excellent in ink fixing properties, and prevents the lowering of the image density with the passage of time and the bleeding of an image. <P>SOLUTION: In the ink-jet recording sheet, the ink receiving layer on the support contains as oil gelling agent. The oil gelling agent is preferably selected from 2,5-diketopiperazine, γ-bis-n-butylamide, and aluminum dialkylphosphates. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ink jet recording sheet. More specifically, it relates to an inkjet recording sheet for a non-aqueous pigment ink used for inkjet recording using a non-aqueous pigment ink in which a coloring material pigment is dispersed in a non-aqueous solvent.

[0002]

2. Description of the Related Art Inkjet recording is a recording of images, characters, etc. by ejecting minute droplets of ink by various operating principles and adhering them to a recording sheet such as paper. Inkjet recording has features such as high speed, low noise, easy multicoloring, great flexibility in recording patterns, and no need for development-fixing. It can be used as a recording device for characters, graphics, color images, etc. for various purposes. Is rapidly spreading in.

Conventionally, in ink jet recording, water-based ink, that is, water or a mixed solvent of water and a hydrophilic solvent, is used.
Inks in which colorants such as dyes and pigments are dispersed or dissolved have been used. However, ink jet recording using a water-based ink has various problems caused by the printing portion of the recording sheet absorbing and expanding the solvent in the ink. The elongation of the recording sheet is caused by the hydrogen bond between the fibers maintaining the mechanical strength of the support being cut by the solvent of the water-based ink, particularly water, which adversely affects the conveyance of the recording sheet in the printer. In addition to adversely affecting the accuracy of the relative positional relationship between the print head and the recording sheet in the printer, it causes undesired phenomena such as a decrease in the dimensional accuracy of the resulting drawing and unevenness in the image. ing.

To solve such a problem, Japanese Patent Laid-Open No. 57-1
No. 0660, No. 57-10661, JP-A-5
JP-A-202324 and JP-A-5-331397 propose to use a non-aqueous ink in which a colorant is dissolved or dispersed in a non-aqueous solvent such as isoparaffin hydrocarbon. According to these proposals, it is possible to carry out ink jet recording which does not cause elongation of the recording sheet at all, has high dimensional accuracy, and causes no image unevenness. Furthermore, due to the low viscosity and low surface tension that are characteristic of non-aqueous solvents, it is possible to increase the drive frequency of the print head compared to inkjet recording using water-based ink, resulting in extremely high-speed inkjet recording. It can be carried out.

As such a non-aqueous ink, a non-aqueous pigment ink in which a pigment as a colorant is dispersed in a high boiling solvent has been proposed.

A recording sheet used for ink jet recording using such a non-aqueous ink is disclosed in JP-A 64-247.
No. 85, etc. propose a recording sheet having an ink receiving layer composed of an oil-absorbing inorganic pigment, an organic pigment, and a water-based adhesive, and JP-A No. 1-255580 discloses an ink receiving layer composed of silica and an adhesive. Recording sheets with layers have been proposed.

However, in these recording sheets, since the ink penetrates deep into the ink receiving layer and further penetrates into the support, only a low image density can be obtained and the color reproducibility in double-color printing is poor. was there. Further, since the high boiling point solvent in the ink stays in the recording sheet together with the colorant pigment, the colorant pigment may move over time, causing a decrease in image density and blurring of the image.

[0008]

An object of the present invention is to provide a high image density in an inkjet recording sheet for a non-aqueous pigment ink used in a printer or plotter using an inkjet recording system using a non-aqueous pigment ink. It is another object of the present invention to provide an inkjet recording sheet for non-aqueous ink, which is excellent in color reproducibility and ink fixability, and is prevented from lowering image density and preventing image bleeding over time.

[0009]

The objects of the present invention are solved by the means described below.

That is, in an ink jet recording sheet for a non-aqueous pigment ink, which comprises an ink solvent absorbing support and an ink receiving layer containing inorganic fine particles, the ink receiving layer contains an oil gelling agent.

More preferably, the oil gelling agent is
2,5-diketopiperazine, γ-bis-n-butylamide and aluminum dialkyl phosphate.

The amount of the oil gelling agent added is most preferably 1 part by mass or more and 30 parts by mass or less based on 100 parts by mass of the inorganic fine particles.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below with reference to preferred embodiments.

The present invention is an ink jet recording sheet for non-aqueous pigment ink comprising an ink solvent absorbing support and an ink receiving layer containing inorganic fine particles, wherein the ink receiving layer contains an oil gelling agent. It is characterized by.

The ink receiving layer in the present invention has an absorptive void mainly containing inorganic fine particles and a binder. Examples of the inorganic fine particles include inorganic fine particles such as silica (synthetic amorphous silica, vapor grown silica, colloidal silica), magnesium carbonate, titanium oxide, zinc oxide, and alumina hydrate.

The oil gelling agent is a drug that applies a phenomenon that an aggregate is formed by intermolecular hydrogen bond and it grows into a huge aggregate, and it is bundled by interaction such as van der Waals force. Then, they become entangled in a knitted pattern and interfere with each other's movement to lose fluidity, and a solvent is entangled in them to cause gelation.

The oil gelling agents used in the present invention include 2,5-diketopiperazine derivatives, 1,2,3,4.
-Dibenzylidene-D-sorbitol, 1,2-hydroxystearic acid, N-lauroyl-L-glutamic acid, γ-bis-n-butylamide, spin-labeled steroids, cholesterol derivatives, aluminum dialkylphosphates, phenolic cyclic oligomers, 2,3-bis-n-hexadecyloxyanthracene, cyclic dipsipeptide derivative, partially fluorinated alkane, cystine derivative,
Sodium bis (2-ethylhexyl) sulfosuccinate, triphenylamine derivative, butyrolactone derivative, fluorinated alkylated oligomer, urea derivative, vitamin H derivative, gluconamide derivative, cholic acid derivative, L-alanine derivative, L-isoleucine derivative, L
-Valine derivatives, oligo (α-amino acids), triaminopyrimidine derivatives, barbituric acid derivatives, trialkyl-1,3,5-benzenetricarboxamides, and the like. Ketopiperazine, γ-bis-n-butylamide and aluminum dialkylphosphate are preferred. Moreover, you may use these individually or in combination of 2 or more types.

The addition amount of the oil gelling agent is 1
It is preferably 1 part by mass or more and 30 parts by mass or less with respect to 00 parts by mass. If the amount is less than 1 part by mass, the fixing properties of the high boiling point solvent and the colorant pigment are insufficient, and ink bleeding is slightly reduced. If it exceeds 30 parts by mass, the ink bleeding will be improved, but the image density will be lowered.

In the present invention, the binder used in the ink receiving layer includes the following polymers.
Lime-processed gelatin, acid-processed gelatin, enzyme-processed gelatin, gelatin derivatives, for example, various gelatins such as gelatin reacted with anhydrides of dibasic acids such as phthalic acid, maleic acid and fumaric acid, polyvinyl alcohols with various saponification degrees, Carboxy-modified, cation-modified and amphoteric polyvinyl alcohols and their derivatives, starches such as oxidized starch, cationized starch and etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, polyvinylpyrrolidone, polyvinylpyridinium halide and polyacrylic acid. Soda, acrylic acid methacrylic acid copolymer salt, polyethylene glycol, polypropylene glycol, polyvinyl ether, alkyl vinyl ether / maleic anhydride copolymer, styrene /
Maleic anhydride copolymer or salt thereof, synthetic polymer such as polyethyleneimine, styrene / butadiene copolymer, conjugated diene copolymer latex such as methylmethacrylate / butadiene copolymer, polyvinyl acetate, vinyl acetate / malein Vinyl acetate polymer latex such as acid ester copolymer, vinyl acetate / acrylic acid ester copolymer, ethylene / vinyl acetate copolymer, acrylic acid ester polymer, methacrylic acid ester polymer, ethylene / acrylic acid ester copolymer Polymer, acrylic polymer or copolymer latex such as styrene / acrylic acid ester copolymer, vinylidene chloride copolymer latex, etc. or functional group-containing monomer such as carboxyl group of these various polymers Functional group modified polymer latex, melamine resin, urea resin, etc. Water-based adhesives such as cured synthetic resin type and polymers such as polymethylmethacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride / vinyl acetate copolymer, polyvinyl butyral, alkyd resin and other synthetic resin type adhesives, either alone or in combination. It is possible to contain it.

If necessary, the ink receiving layer may contain a hardener,
Various additives such as antiseptics, dyes, ultraviolet absorbers, antioxidants, pencil writing agents, pH adjusters and defoamers can be added. For example, active halogen compounds, vinyl sulfone compounds, aziridine compounds, epoxy compounds,
Hardeners such as acryloyl compounds and isocyanate compounds, preservatives such as p-hydroxybenzoic acid ester compounds, benzisothiazolone compounds and isothiazolone compounds described in JP-A-1-102551, γ-aminopropyltriethoxysilane, N- β (aminoethyl) γ
Silane coupling agents such as aminopropyltrimethoxysilane, JP-A-63-204251 and JP-A-1-
UV absorbers such as benzotriazole compounds having a hydroxy-di-alkylphenyl group at the 2-position, such as colored pigments, colored dyes and fluorescent dyes described in Japanese Patent No. 266537.
Antioxidants such as hindered phenol compounds described in JP-A-1-105245, starch granules, plastic pigments, pencil writing agents composed of organic or inorganic fine particles such as barium sulfate having a particle diameter of 0.2 to 5 μm, and caustic soda. , Sodium carbonate, sulfuric acid, hydrochloric acid, phosphoric acid, citric acid, etc.
An H modifier, an octyl alcohol, an antifoaming agent such as a silicon-based agent can be appropriately combined and added.

In the present invention, the dry coating amount of the ink receiving layer is preferably ¹ to 25 g / m ² . If the dry coating amount of the ink receiving layer is less than 1 g / m ² , the ink absorbability is poor, and the ink overflows from the ink receiving layer after printing, and the image is liable to be mixed with color or rubbed. On the other hand, when it exceeds 25 g / m ² , the image density is lowered due to the sinking of the ink.

In the present invention, the ink receiving layer is obtained by applying a coating liquid for the ink receiving layer containing the constituents in a solvent on a support and drying. As a coating method of the ink receiving layer coating liquid, for example, a commonly used coating method such as a slide hopper system, a curtain system, an extrusion system, an air knife system, a roll coating system and a rod bar coating system is used.

In the present invention, the ink receiving layer may be either a single layer or a multilayer of two or more layers. In the case of multiple layers, each layer may have a different composition or the same composition. When forming multiple layers, two or more layers may be coated at once or one layer at a time.

The ink solvent absorbent support of the present invention absorbs non-aqueous ink, and for example, general paper, coated paper, baryta paper and the like are used. Furthermore, the support is not particularly limited as long as it is a support such as a cloth that can absorb the non-aqueous ink.

The support of the present invention may be provided with an undercoat layer before coating the ink receiving layer in order to improve the coatability of the ink receiving layer coating liquid. To such an undercoat layer, pigments, various water-soluble polymers, latexes, hardeners, surfactants and the like can be appropriately combined and added.

The support in the present invention has an antistatic property,
A back coat layer may be provided in order to impart transportability, curl prevention property, and the like. An inorganic or organic antistatic agent, a water-soluble binder, a synthetic resin latex, a hardener, a pigment, a surfactant and the like can be added to such a back coat layer in an appropriate combination.

The non-aqueous pigment ink used for recording on the ink jet recording sheet of the present invention is generally used in an ink jet printer using a non-aqueous ink, contains a coloring material pigment and a high boiling point solvent, and is required. Depending on the case, it may contain a dispersant, a penetrating agent, a low boiling point solvent, an antioxidant, an ultraviolet absorber and the like.

Specific examples of the coloring material pigment in the non-aqueous pigment ink include carbon black, furnest black, lamp black, acetylene black, channel black, C.I. I. Pigment Black, Orthoaniline Black, Toluidine Orange, Permanent Carmine FB, First Yellow AAA, Disazo Orange PMP, Lake Red C, Brilliant Carmine 6B, Phthalocyanine Blue, Quinacridone Red,
C. I. Pigment Blue, C.I. I. Pigment Red, C.I. I. Pigment yellow, dioxane violet, pictoria pure blue, alkali blue toner, alkali blue R toner, first yellow 10
G, ortho-nitroaniline orange, toluidine red, barium red 2B, calcium red 2B, pigment scar red 3B lake, anthocin 3B lake, rhodamine 6B lake, methyl violet lake, basic blue 6B lake, fast sky blue, reflex blue G, Brilliant Green Lake, Phthalocyanine Green G, Navy Blue, Ultramarine Blue, Iron Oxide Powder, Zinc Flower, Calcium Carbonate, Clay, Barium Sulfate,
Alumina white, aluminum powder, daylight fluorescent pigment, pearl pigment and the like can be mentioned.

The high boiling point solvent in the non-aqueous pigment ink is
Boiling point is 120 to 400 ° C, preferably 120 to 350 ° C
With a solvent of, it becomes a stable dispersion medium for finely divided pigments,
It serves to prevent ink from sticking to the nozzle tip of the print head. Therefore, it is preferable to prevent the ink from drying at room temperature, have a high penetration speed with respect to the recording sheet, and have a flow characteristic that follows a print head having a high-speed ejection property.

Examples of the high boiling point solvent include aliphatic hydrocarbon solvents, carbitol solvents, cellosolve solvents, higher fatty acid ester solvents, higher alcohol solvents, higher fatty acid solvents, aromatic hydrocarbon solvents and the like. To be Among them, liquid paraffin and aliphatic hydrocarbon solvents are suitable because they have little odor.

Examples of the aliphatic hydrocarbon solvent include IP solvent manufactured by Nippon Oil Co., Ltd., Shellsol D40 manufactured by Shell Chemical Co., Ltd.
Shersol D70, Shersol 70, Shersol 71, Isopar E, Isopar G, Isopar H, Isopar L, Isopar M, Exol D30, Exol D40, Exol D80, Exol D110, Exol D130, Exol D14
0, Exol DSP100 / 140 and the like.

Further, butyl carbitol can be used as the carbitol solvent, and ethyl cellosolve can be used as the cellosolve solvent. Examples of the higher fatty acid ester-based solvent include dioctyl phthalate, dibutyl succinic acid isobutyl ester, adipic acid isobutyl ester, dibutyl sebacate, di-2-ethylhexyl sebacate, and the like.
Methyl hexanol, oleyl alcohol, trimethyl hexanol, trimethyl butanol, tetramethyl nonanol, 2-pentyl nonanol, 2-nonyl nonanol, 2-hexyl decanol, etc. are mentioned. Further, examples of the higher fatty acid-based solvent include oleic acid,
Examples of the aromatic hydrocarbon solvent include diisopropyl naphthalene.

These solvents can be used alone. However, in order to adjust the viscosity, adjust the penetration into the recording sheet, and adjust the wettability between the print head and the ink-wetted portion of the printer, the solvent is used. A method of using a group hydrocarbon solvent and a polar solvent in combination is often used.

Examples of polar organic solvents include alcohols, particularly long chain alcohols, glycols, polyglycols, esters and ethers of glycols and polyglycols, particularly mono- and di-alkyl ethers of glycols and polyglycols, ketones and the like. . Further, esters of dicarboxylic acids, for example, dioctyl sebacate ester and the like can be mentioned.

[0035]

The present invention will be described in detail below with reference to examples, but the contents of the present invention are not limited to the examples.

(Preparation of support) 80 parts LBKP, NBK
P20 parts, light calcium carbonate 8 parts, heavy calcium carbonate 8 parts, talc 8 parts, alkyl ketene dimer 0.1
Parts, cationic polyacrylamide 0.03 parts, cationized starch 0.8 parts, sulfuric acid band 0.4 parts and an appropriate amount of water to form a slurry, and using a Fourdrinier paper machine, basis weight 90 g / m ^Two supports were prepared. An ink jet recording sheet was obtained by applying a 25% concentration ink receiving layer coating solution having the following composition to the support by a curtain method so that the dry coating amount was 15 g / m ² .

[0037]   Example 1   Ink receiving layer coating liquid formulation 1 Synthetic amorphous silica (Fineseal X37B, manufactured by Tokuyama Corporation) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts 2,5-Diketopiperazine 1 part           63 parts of water

Example 2 An ink jet recording sheet was prepared in the same manner as in Example 1 except that the coating liquid for the ink receiving layer had the following composition. Ink receiving layer coating liquid formulation 2 Synthetic amorphous silica (Fineseal X37B, manufactured by Tokuyama Corporation) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts 2,5-Diketopiperazine 10 parts Water 90 parts

Example 3 An ink jet recording sheet was prepared in the same manner as in Example 1 except that the coating liquid for the ink receiving layer was changed to the following composition. Ink Receptor Layer Coating Composition 3 Synthetic Amorphous Silica (Fineseal X37B, manufactured by Tokuyama Corp.) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts 2,5-Diketopiperazine 30 parts Water 150 parts

Example 4 An ink jet recording sheet was prepared in the same manner as in Example 1 except that the coating liquid for the ink receiving layer was changed to the following composition. Ink receiving layer coating liquid formulation 4 Synthetic amorphous silica (Fineseal X37B, manufactured by Tokuyama Corp.) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts 2,5-Diketopiperazine 0.5 parts Water 61.5 parts

Example 5 An ink jet recording sheet was prepared in the same manner as in Example 1, except that the coating liquid for the ink receiving layer was changed to the following composition. Ink Receptor Layer Coating Composition 5 Synthetic Amorphous Silica (Fineseal X37B, manufactured by Tokuyama Corp.) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts 2,5-Diketopiperazine 35 parts Water 165 parts

Example 6 An ink jet recording sheet was prepared in the same manner as in Example 1 except that the coating liquid for the ink receiving layer was changed to the following composition. Ink Receptor Layer Coating Composition 6 Synthetic Amorphous Silica (Fineseal X37B, manufactured by Tokuyama Corp.) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts γ-bis-n-butylamide 1 part Water 63 parts

Example 7 An ink jet recording sheet was prepared in the same manner as in Example 1 except that the coating liquid for the ink receiving layer had the following composition. Ink receiving layer coating liquid formulation 7 Synthetic amorphous silica (Fineseal X37B, manufactured by Tokuyama Corp.) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts γ-bis-n-butylamide 30 parts Water 150 parts

Example 8 An ink jet recording sheet was prepared in the same manner as in Example 1 except that the coating liquid for the ink receiving layer had the following composition. Ink receiving layer coating liquid formulation 8 Synthetic amorphous silica (Fineseal X37B, manufactured by Tokuyama Corp.) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts Aluminum dialkyl phosphate 1 part Water 63 parts

Example 9 An ink jet recording sheet was prepared in the same manner as in Example 1, except that the coating liquid for the ink receiving layer was changed to the following composition. Ink receiving layer coating liquid formulation 9 Synthetic amorphous silica (Fineseal X37B, manufactured by Tokuyama Corporation) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts Aluminum dialkyl phosphate 30 parts Water 150 parts

Comparative Example 1 Ink Receptor Layer Coating Liquid Blending 10 An ink jet recording sheet was prepared in the same manner as in Example 1, except that the ink receiving layer coating liquid was blended as follows. Synthetic amorphous silica (Fineseal X37B, manufactured by Tokuyama Corp.) 100 parts Polyvinyl alcohol (10% aqueous solution) 400 parts Water 60 parts

Examples 1 to 9 produced as described above,
Regarding the inkjet recording sheet for non-aqueous ink of Comparative Example 1, a non-aqueous pigment inkjet printer (PJ36
00: By using Olympus Optical Co., Ltd., a solid black solid printing pattern was printed, and evaluation was performed by the following method. The results are shown in Table 1.

(Evaluation Method) (Printing Density) The evaluation of the “printing density” is carried out immediately after printing by printing 1
The optical density of the solid printed portion of the black ink after a week was measured with an optical densitometer (RD-919 manufactured by Macbeth).
The larger this value is, the higher the print density is, and the optical density is 1.5.
When it is at least above, it is good, and when it is at least 1.8, it is very good.

(Ink Penetration) The cross section of the portion where the optical density was measured was observed with a microscope (300 magnification) to observe and evaluate the degree of penetration of the coloring material. The case where the coloring material did not penetrate into the support was designated as "○", and the case where the coloring material penetrates into the support was designated as "x".

(Ink bleeding) The "ink bleeding" was evaluated by visually observing and evaluating the bleeding of the ink from the periphery of the solid printed portion after 24 hours.
The case where there was no bleeding was marked with “◯”, the case where slight bleeding occurred was marked with “Δ”, and the case where bleeding was clearly generated was marked with “x”.

(Ink overflow property) "Ink overflow property" was evaluated by visually observing and evaluating the ink drying property immediately after solid printing, and a mark "○" indicates that ink was not completely overflowed and printing was performed. The one in which overflow printing unevenness was generated was designated as “Δ”, and the one in which overflow printing was generated was designated as “x”.

(Fixing property) "Fixing property" was evaluated by rubbing the surface of the solid printed portion of the black ink with the index finger once in one direction, and the coloring agent did not spread on the surrounding white paper (unprinted) portion. (Fixing property is good) is indicated by "A", that there is no problem in practical use but the colorant has spread, and "O" is indicated, and that in which the colorant has fallen off the surface (poor fixing property) is indicated by "X".

[0053]

[Table 1]

As is clear from Table 1, in Examples 1 to 9 in which the ink-receiving layer contains the oil gelling agent, the image density was high and the image density did not decrease with time, and the ink fixability was excellent. It can be seen that the image blur is also good. In Comparative Example 1, the high-boiling point solvent and the colorant pigment reach the support, so that the printing density is low, and the colorant pigment remains with the high-boiling point solvent, causing a decrease in density over time, causing ink bleeding and fixing. The sex was also a bad level.

[0055]

INDUSTRIAL APPLICABILITY According to the present invention, an ink jet recording sheet for a non-aqueous pigment ink, which comprises an ink receiving layer provided on an ink solvent absorbing support, has a high image density, is excellent in ink fixability, and is aged. An ink jet recording sheet for a non-aqueous pigment ink in which a decrease in image density and image blurring due to the above are prevented can be obtained.

Claims (3)

[Claims] 1. An ink jet recording sheet for non-aqueous pigment ink, comprising an ink solvent absorbing support and an ink receiving layer containing inorganic fine particles, wherein the ink receiving layer contains an oil gelling agent. Inkjet recording sheet for non-aqueous pigment ink. 2. The oil gelling agent according to claim 1, wherein the oil gelling agent is an oil gelling agent selected from 2,5-diketopiperazine, γ-bis-n-butylamide and aluminum dialkylphosphate. Inkjet recording sheet for water-based pigment ink. 3. The non-aqueous pigment ink according to claim 1, wherein the amount of the oil gelling agent added is 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the inorganic fine particles. Inkjet recording sheet.