JPH08258396A - Ink jet recording sheet and its manufacture - Google Patents

Abstract

PURPOSE: To provide an ink jet recording sheet and its manufacturing method wherein water-color ink is used, recording density is high in ink jet recording, and it is equipped with an excellent carrying property as well as characteristics wherein an irregularity in a recorded part, its depressed state, and strike through of ink are little. CONSTITUTION: At least one ink accepting layer is provided on one side of a base material, and a starch grain layer is provided between the base material and the ink accepting layer. The ink jet recording sheet is manufactured by coating the ink accepting layer on the base material having the starch grain layer wherein starch grain and an aqueous binder are main constituents.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording sheet for recording with an aqueous ink. More specifically, the recording density is high, and
The present invention relates to an ink jet recording sheet which is extremely easy to convey in a printer and which is capable of remarkably reducing flicker and strike-through of ink and a method for producing the same.

[0002]

2. Description of the Related Art Ink jet recording is a system in which minute droplets of ink are ejected by various operating principles and adhered to a recording sheet such as paper to record images, characters, etc. It has features such as easy multicoloring, great flexibility in recording patterns, and no need for development-fixing.
As a recording device for various figures and color images including kanji, it is rapidly spreading for various purposes.

As a recording sheet used in this ink jet recording system, various efforts have been made in terms of equipment and ink composition so that high quality paper or coated paper used in ordinary printing or writing can be used. Came. However, with the improvement of the performance of inkjet recording devices and the expansion of applications such as higher speed, higher definition or full color of the device, it is required that the recording sheet also has the following advanced characteristics. Became. (1) It has excellent transportability when recording with a normal recording device. (2) It is possible to prevent strike-through and cockling of the image recorded on the surface and obtain a high-quality recorded image under a wide range of temperature and humidity conditions. (3) The recording dot density and the image density are high. (4) Image color and sharpness are good. (5) The print dot shape is good. (6) Good ink absorption. (7) The recorded image has good image storability such as water resistance, light resistance, and ozone resistance. (8) In the coat type recording sheet, the adhesiveness of the coating layer is high and there is little powder falling. (9) Yellowing of the recording sheet itself is unlikely to occur. (10) Compared with the dot diameter in the single-color portion, the dot diameter in the heavy-color portion hardly changes, there is almost no bleeding in the heavy-color portion, and a high-definition recorded image can be obtained.

In the past, many proposals have been made focusing on the improvement of specific performance among these. For example, JP-A-62-282967 has an ink holding layer and an ink transport layer on a substrate in order to improve ink absorbency, optical density of recorded image, glossiness, curl resistance and the like. Further, a recording material provided with a curl suppressing layer having the same or similar physical properties as the ink holding layer is disclosed. Further, in JP-A-61-235184, in order to improve ink absorbability, image clarity, transportability, etc., a recording material provided with an ink receiving layer is provided with a curl prevention layer made of a resin such as polyacrylamide. The example provided is disclosed. Furthermore, JP-A-62-162586 and JP-A-62-16255.
No. 87 discloses a printer sheet by providing a layer made of a very small amount (0.01 to 1.0 g / m ² ) of powder on the opposite surface or both surfaces of the recording layer (film base material). A recording material having improved transportability and blocking resistance is disclosed.

[0005]

However, a recording material provided with the above-mentioned curl suppressing / preventing layer (Japanese Patent Laid-Open No. Sho 62-2).
No. 82967) aims to improve contactability with the printer head by curling and preventing curling, and to improve transportability. However, particularly in a printer using a cut sheet, it is still caused by the property of the sheet itself. In addition, there is a problem in that pick-up at the time of sheet feeding is defective, and therefore, conveyance defects such as jamming (paper jam), skew feeding, and double feeding are likely to occur, and stable continuous recording cannot be performed.

Further, the recording material having a layer made of the above-mentioned powder (Japanese Patent Laid-Open No. 62-162586, etc.) has a problem that not only the powder falls but also the transportability is not satisfactory.

The present invention solves these problems and provides a high recording density necessary for ink jet recording using a water-based ink, in addition to excellent transportability due to good pickup during paper feeding. However, it is an object of the present invention to provide an ink jet recording sheet having various properties such as excellent powder dropping performance, which is capable of remarkably reducing unevenness and flicker in a recording portion, and a method for producing the same.

[0008]

In order to achieve this object, the present invention provides an ink jet recording sheet having at least one ink receiving layer on one side of a support, which comprises starch particles and an aqueous binder as main components on the surface. And an ink-receiving layer coated on a support having a starch particle layer formed thereon, and a method for producing the same.

In the ink jet recording sheet of the present invention, the starch particles provided on the surface of the support form a layer structure while maintaining the particle shape so that the space between the ink receiving layer and the support is maintained while maintaining the ink absorbability. The adhesive strength of the recording medium is improved, the powder is prevented from falling off from the ink receiving layer, and the slip between the pickup roll and the recording sheet when the recording sheets are sequentially picked up from the bundle of recording sheets installed in the printer is prevented.

Further, by reducing the irregularities on the surface of the support and making the thickness of the ink receiving layer uniform, the dye distribution in the ink receiving layer containing the dye fixing agent is made uniform, which is caused by the localization of the dye. The uneven density of the recording portion is eliminated. In addition, the permeation of the recording portion of the recording sheet and the strike-through of the ink are prevented by delaying the permeation of the ink solvent separated from the dye in the ink receiving layer into the paper.

The starch particles used in the starch particle layer of the present invention are produced from raw materials such as corn (corn starch), wheat, barley, rice, potatoes, cassava (tapioca), sweet potatoes (sweet potatoes) and sago. Or the following (a)-
(I) can be mentioned, and rice starch powder is particularly preferable. (A) Oxidized starch obtained by oxidizing with an oxidizing agent such as sodium hypochlorite. (B) Acid-treated starch treated with hydrochloric acid or sulfuric acid. (C) Enzyme-treated starch. (D) Dialdehyde starch reacted with periodic acid. (E) Esterified starch such as acetylated starch, urea phosphorylated starch, phosphorylated starch and the like. (F) Etherified starch such as hydroxyalkylated starch and carboxyalkylated starch. (G) Cationized starch. (H) Crosslinked starch such as formaldehyde crosslinked starch, epichlorohydrin crosslinked starch, and phosphoric acid crosslinked starch. (I) Graft-polymerized starch obtained by polymerizing starch having active sites with vinyl monomers such as acrylic acid, acrylonitrile, acrylamide, methacrylic acid ester, vinyl acetate and cyclic monomers such as epoxide, episulfide, imine and lactam.

Of these starch particles, those which have little or no solubility in cold water are preferable for maintaining the particle shape in the ink jet recording sheet of the present invention.
It is almost insoluble in water at 40 ° C or lower, and the gelatinization start temperature is preferably 50 ° C or higher. The starch particle size is preferably in the range of 1 to 20 μm in volume average particle size in order to satisfy both the adhesive strength with the ink receiving layer, the absorption speed and amount of ink, and the quality of the recorded image. It is preferably in the range of 2 to 10 μm. The starch particle layer of the present invention is preferably composed of the above-mentioned starch particles and an aqueous polymer binder, and the aqueous polymer binder is preferably 5 parts by weight or more and 100 parts by weight to 100 parts by weight of the starch particles. If the amount of the aqueous polymer binder is less than 5 parts by weight, the strength of the starch particle layer is insufficient and slippage between the pickup roll and the recording sheet may occur due to detachment of the ink receiving layer. On the other hand, if the amount of the aqueous polymer binder exceeds 100 parts by weight, sufficient voids are not formed in the starch particle layer, the ink absorbability is deteriorated, and the recording performance is deteriorated.

Examples of the aqueous polymer binder used in the starch particle layer of the present invention include starch derivatives such as oxidized starch, etherified starch and phosphoric esterified starch; cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose; casein; Polyvinyl alcohol derivatives such as gelatin, soybean protein, polyvinyl alcohol, or silyl-modified polyvinyl alcohol; polyvinylpyrrolidone, maleic anhydride resin, styrene-butadiene copolymer, methyl methacrylate-butadiene copolymer, and other conjugated diene copolymer latex. An acrylic (co) polymer latex such as a polymer or copolymer of an acrylic ester and a methacrylic ester; a vinyl copolymer latex such as an ethylene vinyl acetate copolymer; Functional group-modified (co) polymer latexes with monomers containing functional groups such as carboxy groups of these various (co) polymers; water-based adhesives such as thermosetting synthetic resins such as melamine resins and urea resins; polymethylmethacrylate Acrylic or methacrylic acid polymer or copolymer resin such as; polyurethane resin,
Mention may be made of unsaturated polyester resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral, alkyd resins. Among these water-soluble binders, from the viewpoint of recording performance and adhesive strength, oxidized starch, etherified starch,
The use of starch derivatives such as phosphated starch is preferred. In addition to this aqueous polymer binder, the starch particle layer in the present invention contains a white inorganic pigment, a cationic dye fixing agent, a surface sizing agent, and other additives for the purpose of improving recording performance and controlling ink absorption rate. obtain.

The coating amount of the starch particle layer is 2 g / m ² or more 2
It is preferably 0 g / m ² or less, and when it is less than 2 g / m ² , a layer is not formed and a sufficient effect cannot be obtained.
^When it exceeds ² , the coloring property of the dye is deteriorated due to the hiding property of the starch particles, and the recording density is decreased.

The ink receiving layer of the present invention comprises a white inorganic pigment,
It is preferably composed mainly of a water-soluble binder and a cationic dye fixing agent. Examples of the white inorganic pigment include calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide,
Zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate,
Examples thereof include synthetic amorphous silica, pseudo-boehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrohaloysite, magnesium carbonate, magnesium hydroxide and the like. Among these, porous synthetic amorphous silica having a large pore volume is preferable. It is also possible to use starch particles.

As the cationic dye fixing agent, a monomer or oligomer of a primary to tertiary amine or quaternary ammonium salt, which dissociates when dissolved in water to exhibit a cationic property,
Mention may be made of polymers, preferably oligomers or polymers. In particular, the cation charge amount by the colloid titration method is 1 to 10 meq. / G of cationic dye fixing agent. 1 meq. If it is less than / g, the fixing performance of the water-soluble dye in the water-based ink is poor, and the water resistance of the recorded image is reduced. Also, 10 meq. If it exceeds / g, the water resistance of the recorded image can be improved with a small amount, but the light resistance and ozone resistance of the recorded image are poor, and the yellowing of the recording sheet is deteriorated.

The white inorganic pigment, the starch particles, the aqueous polymer binder, and the cationic dye fixing agent in the starch particle layer and the ink receiving layer of the ink jet recording sheet of the present invention are one kind or a mixture of two or more kinds. May be.

In the ink receiving layer of the present invention, the aqueous polymer binder is 10 to 100 parts by weight, the aqueous polymer binder is 10 to 100 parts by weight, and the cationic dye fixing agent is 0.1 to 100 parts by weight. 5 g / m ² and a cation charge amount of 0.1 to 50 meq / m ² are preferably contained.

As the support in the present invention, paper or a thermoplastic resin film, synthetic paper, synthetic resin laminated paper such as photographic support, sheet-like material such as non-woven fabric mainly composed of wood fiber or synthetic fiber Is mentioned. In the case of paper, addition of internal sizing agent, no addition, use of sizing agents such as neutral sizing agent, polymer sizing agent, and acidic sizing agent alone or in combination, with or without filler may be used without any limitation. Absent. As the internal filler for the paper support, conventionally known pigments are used alone or in combination as a white pigment.

As a method for producing the ink jet recording sheet of the present invention, for example, pulp fibers are disintegrated into a slurry, and if necessary, a filler, a sizing agent and other additives are added, papermaking is carried out by a paper machine and dried. Or, after the papermaking, size-press the starch particles and the water-soluble polymer binder, or
Coat with a gate roll coater, dry and machine calender. Alternatively, after obtaining the support sheet, a starch particle layer is provided using a coating device or a size press device. The method for providing the ink receiving layer may be either an on-machine coater or an off-machine coater. After coating, further calender finish. The coating amount of the ink receiving layer is preferably in the range of 5 to 30 g / m ² .

Other additives such as colloidal silica, a pigment dispersant, a thickener, a fluidity improver, a defoamer, and a suppressor are added to the support, the starch particle layer and the ink receiving layer in the ink jet recording sheet of the present invention. Foaming agent, release agent, foaming agent,
A penetrant, an anti-bacterial agent, a water resistant agent, a wet paper strength enhancer, a dry paper strength enhancer and the like can be appropriately blended.

The aqueous ink referred to in the present invention is a recording liquid containing a colorant, a solvent, and other additives. Examples of the colorant include water-soluble dyes such as direct dyes, acid dyes, basic dyes, reactive dyes and food dyes. Examples of the solvent for the aqueous ink include water and various water-soluble organic solvents. Other additives include, for example, pH.
Examples include regulators, sequestering agents, fungicides, viscosity regulators, surface tension regulators, wetting agents, surfactants and rust inhibitors.

[0023]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. Further, “parts” and “%” shown in the examples represent parts by weight and% by weight, unless otherwise specified.

COMPARATIVE EXAMPLE 1 Freeness 450 ml CSF LBKP 67 parts, freeness 45
To a pulp slurry consisting of 8 parts of 0 ml CSF NBKP, 0.6 parts of cationic starch, 10 parts of talc, 10 parts of heavy calcium carbonate, 5 parts of light calcium carbonate and 0.1 part of alkyl ketene dimer were added, and p of the pulp slurry was added.
H was adjusted to 8.2, papermaking was dried with a Fourdrinier paper machine, followed by impregnation with a size press to a concentration of 10% aqueous solution of oxidized starch so that the solid content was 5 g / m ² on both sides, drying, and further machine calendering. After finishing, a coated base paper having a basis weight of 63 g / m ² was obtained. On this coated base paper, 75 parts of synthetic amorphous silica (Fineseal X37B, manufactured by Tokuyama Soda Co., Ltd.), synthetic amorphous silica (Cyroid 620, manufactured by Fuji Devison Co., Ltd.) 25
Part, polyvinyl alcohol (PVA117, Kuraray Co., Ltd.) 20 parts and cationic dye fixing agent (Smilet's Resin 1001, Sumitomo Chemical Co., Ltd., cationic charge amount 3.5 m
eq. / G) 30% of a coating solution having a concentration of 18% was coated with an air knife coater so that the solid content was 10 g / m ^2, and the maximum temperature of hot air was 120 ° C. or higher and drying was performed.

Example 1 Freeness 450 ml CSF LBKP 67 parts, freeness 45
To a pulp slurry consisting of 8 parts of 0 ml CSF NBKP, 0.6 parts of cationic starch, 10 parts of talc, 10 parts of heavy calcium carbonate, 5 parts of light calcium carbonate and 0.1 part of alkyl ketene dimer were added, and p of the pulp slurry was added.
H was adjusted to 8.2, papermaking was dried with a Fourdrinier paper machine, and then rice starch particles (average particle size 4 μm) were 100 with a size press.
Parts and 10 parts of oxidized starch as an aqueous binder were impregnated with an impregnating solution having a concentration of 10% so as to have a solid content of 4.5 g / m ² on both sides, dried, and machine calendered to give a basis weight of 63 g / m ^2. An inkjet recording sheet of Example 1 was obtained in the same manner as Comparative Example 1 except that the coated base paper of m ² was obtained.

Comparative Example 2 Instead of size-pressing the aqueous solution of oxidized starch in Comparative Example 1, an aqueous solution of oxidized starch having a concentration of 20% was used as solids on both sides of 3.2.
Apply with a gate roll coater to achieve g / m ² ,
An inkjet recording sheet of Comparative Example 2 was obtained in the same manner as Comparative Example 1 except that a coated base paper having a basis weight of 63 g / m ² was obtained.

Example 2 In Comparative Example 1, LBKP60 having a freeness of 380 ml CSF.
Parts, 15 parts of NBKP having a freeness of 480 ml CSF, and 0.6 parts of cationic starch, 20 parts of heavy calcium carbonate, 15 parts of light calcium carbonate and 0.1 part of alkyl ketene dimer were added to a pulp slurry to prepare a pulp slurry. The pH was adjusted to 8.2, papermaking was dried with a Fourdrinier paper machine, and subsequently 100 parts of wheat starch particles (average particle diameter 12 μm) and 20 parts of oxidized starch as an aqueous binder were mixed to give a concentration of 40%.
Except that a coating base paper having a basis weight of 87 g / m ² was obtained by coating with a gate roll coater so as to have a solid content of 6 g / m ² on both sides, drying, and machine calendering. An inkjet recording sheet of Example 2 was obtained in the same manner as Comparative Example 1.

Example 3 In Comparative Example 1, LBKP60 having a freeness of 380 ml CSF.
Parts, 15 parts of NBKP having a freeness of 480 ml CSF, and 0.6 parts of cationic starch, 20 parts of heavy calcium carbonate, 15 parts of light calcium carbonate and 0.1 part of alkyl ketene dimer were added to a pulp slurry to prepare a pulp slurry. The pH was adjusted to 8.2, papermaking was dried with a Fourdrinier paper machine, and machine calendering was performed to obtain a base paper having a basis weight of 75 g / m ² . On one side of this base paper, rice starch particles (average particle size 4μ
m) 100 parts and 5 parts of polyvinyl alcohol (PVA117, manufactured by Kuraray Co., Ltd.) as an aqueous binder were applied with an air knife coater to a solid content of 12 g / m ² to obtain a coating solution having a concentration of 40%. An ink jet recording sheet of Example 3 was obtained in the same manner as Comparative Example 1 except that 87 g / m ² coated base paper was obtained.

Example 4 In Example 3, 50 parts of rice starch particles (average particle size 4 μm),
Concentration 2 with 20 parts of synthetic amorphous silica (Cyroid 620, manufactured by Fuji Davisson) and polyvinyl alcohol (PVA 117, manufactured by Kuraray Co., Ltd.) as an aqueous binder.
Except that 2% of the coating solution was coated by an air knife coater so that the 12 g / m ² on a solids to give a basis weight 87 g / m ² coating base paper, carried out in the same manner as in Comparative Example 1 Example An inkjet recording sheet of No. 4 was obtained.

Comparative Example 3 In Example 3, 100 parts of synthetic amorphous silica (Cyroid 620, manufactured by Fuji Davisson) and polyvinyl alcohol (PVA 117, manufactured by Kuraray) 20 as an aqueous binder were used.
12g / m2 of solid content of 17% concentration coating solution
It is coated with an air knife coater so that it becomes ^2, and the basis weight is 87
An inkjet recording sheet of Comparative Example 3 was obtained in the same manner as Comparative Example 1 except that a g / m ² coated base paper was obtained.

Example 5 Instead of size-pressing the oxidized starch aqueous solution in Comparative Example 1, 100 parts of rice starch particles (average particle size 4 μm) and 100 parts of oxidized starch as an aqueous binder were mixed to obtain a concentration of 20%.
The same procedure as in Comparative Example 1 was carried out except that a coating liquid having a solid content of 5.0 g / m ² on both sides was coated with a gate roll coater to obtain a coated base paper having a basis weight of 64 g / m ^2. An inkjet recording sheet of Example 5 was obtained.

<Performance> The performance of the ink jet recording sheet was measured by the following method. (1) Recording Density The printing density is the ink jet printer (BJC-82
0J, manufactured by Canon Inc.), and the black print portion was measured using a Macbeth RD-918 model. (2) Unevenness in recording area Unevenness in the printing area is caused by ink jet printer (MJ-7
00V2C), cyan solid printing was performed in the super fine mode, and the density unevenness of the recording portion was visually evaluated. Evaluation Criteria A: No density unevenness is observed in the recording area. B: Very slight density unevenness is observed in the recording area. Poor: Density unevenness is noticeable in the recording area. (3) Blobs in the recording part and strike-through of the ink
C-600J (manufactured by Canon Inc.) was used to perform solid blue (cyan + magenta) printing, and the rubbed state of the recording portion after standing and drying overnight was visually evaluated. In addition, the strike-through of the ink was also visually evaluated. Bottling evaluation criteria ○: Bottling is not recognized in the recording area. Δ: Slight fluttering is recognized in the recorded area. Poor: Prickles are clearly recognized in the recorded area. Strikethrough Evaluation Criteria: No ink strikethrough is observed on the back surface of the recording area. Δ: Slight strike-through of the ink is recognized in the recording area. X: Ink strike-through is observed in the recording area. (4) Transportability Transportability is based on the inkjet printer (BJ-10V,
(Manufactured by Canon Inc.) with a cut sheet feeder attached, the edge of the inkjet recording sheet was held under the environment of 20 ° C. and 65% RH, forcibly causing a feeding failure, and then 100 sheets were passed. It was evaluated by the number of accident sheets. Evaluation Criteria A: The number of accident sheets per 100 sheets is 0 to 1. B: 2 to 10 accident sheets per 100 sheets. C: Feeding failure occurred and 100 sheets could not be conveyed.

The results of measuring the performance of the ink jet recording sheets of Comparative Examples 1-2 and Examples 1-3 are shown in Table 1 below.

[0034]

[Table 1]

[0035]

The ink jet recording sheet of the present invention is
By having a starch particle layer containing starch particles and an aqueous binder as a main component between the support and the ink receiving layer, unevenness of a recording portion when inkjet recording is performed using an aqueous ink,
Bottling and strike-through of ink are remarkably reduced, and the problem of pick-up failure due to slipping of the pick-up roll at the time of sheet feeding caused by powder falling from the sheet is solved, enabling stable continuous printing. That is, according to the present invention, it has a high recording density required for ink jet recording using a water-based ink, has little unevenness in the recording portion, swelling and ink strike-through, and has excellent transportability due to good pickup performance. An inkjet recording sheet and a method for manufacturing the same are provided.

Claims (2)

[Claims] 1. An inkjet recording sheet having at least one or more ink receiving layers on one side of a support, wherein a starch particle layer containing starch particles and an aqueous binder as main components is provided between the support and the ink receiving layer. An inkjet recording sheet characterized by: 2. An ink jet recording sheet having at least one or more ink receiving layers on one side of a support, wherein the ink receiving layer is coated on a support having a starch particle layer containing starch particles and an aqueous binder as main components. A method for manufacturing an inkjet recording sheet, comprising: