JP2002293011A - Ink jet recording paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording paper, which has a high water absorbability and quick ink drying properties and the favorable and excellent reproducibility of an ink image. SOLUTION: The base paper of this ink jet recording paper is a multilayered paper-made one manufactured by a paper-making method, the density of the topmost layer of which is 0.7 to 0.9 g/cm<3> and those of its middle layer and of its undermost layer are 0.2 to 0.8 g/cm<3> .

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 paper mainly using an aqueous ink, and more particularly to an excellent ink-jet recording paper having high water absorption, quick drying, and good clarity of an ink-jet recorded image. It is.

[0002]

2. Description of the Related Art An ink jet recording apparatus adopts an ink jet recording method in which minute droplets of ink are directly ejected onto recording paper by various operating principles represented by a piezo type and a thermal type. This is a device for recording.

This ink-jet recording apparatus has advantages such as high speed, low noise, easy multi-coloring, high flexibility of recording patterns, and no need for development and fixing. In particular, yellow, magenta and cyan are contained in a solvent. When an ink of each color containing a color material such as black or the like is used, it is possible to obtain an image comparable to multi-color printing by a plate making method, and it has been rapidly spreading in recent years.

On the other hand, the ink jet recording paper suitably used in such an ink jet recording apparatus has high opacity, high recording density, vivid color tone, quick ink absorption, and even when ink dots overlap. Ink does not bleed, dots do not grow larger than necessary,
Ink jet recording suitability such as high whiteness is required. Furthermore, it is required to have a suitable transporting property so that a paper jam does not occur in the ink jet recording apparatus.

[0005] Recently, the object of ink jet recording is
A wide range of applications are being developed, taking advantage of the fact that printing information can be easily changed, such as menus in coasters and cafeterias, as well as publishing / printing paper and information paper.

As a recording sheet used in the ink jet recording system, a recording sheet in which a porous ink absorbing layer is provided on a support conventionally called ordinary paper or ink jet recording paper has been used. .

However, when these conventional recording sheets are to be applied as they are to bulky coasters or menu sheets, there are some serious problems. That is, it is difficult to produce a bulky recording paper with a single layer, and it is difficult to obtain necessary water absorption because of a single layer (in the case of a coaster), and the drying property and the clarity of an ink jet recorded image are poor. Was not tolerable.

[0008] Ink jet recording paper technology has not been developed for applications requiring water absorption, drying properties, and reproducibility of ink jet recorded images while being bulky, such as coasters and menu applications.

[0009]

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide an ink jet recording sheet which is excellent in water absorption, drying properties and reproducibility of an ink jet recorded image when ink jet recording is performed. It is.

[0010]

Means for Solving the Problems The invention according to claim 1 of the present invention, which has solved the above-mentioned problems, is a multi-layer base paper whose base paper is manufactured by a laminating method, wherein the density of the uppermost layer of the multi-layer base paper is Is 0.7 to 0.9 g / cm ³ , and the density of the middle layer and the lowermost layer is 0.2 to 0.8 g / cm ³ .

[0011] The invention according to claim 2 is characterized in that at least one of the middle layer and the lowermost layer of the multi-layer base paper contains thermofoamable microcapsules.

[0013] The invention according to claim 3 is that at least one of the middle and lowermost layers of the multi-layered base paper is provided with a bulk-forming pulp of 20 to 40%.
It is characterized by containing 30% by weight.

[0013] The invention according to claim 4 is characterized in that at least one of the middle layer and the lowermost layer of the multi-layer base paper contains a bulking agent.

The invention according to claim 5 is characterized in that recycled pulp is contained in an amount of 50% by weight or more as a raw pulp for a multi-layer base paper.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the ink jet recording paper according to the present invention will be described in more detail. First, the base paper according to the present invention is a multi-layer base paper manufactured by a laminating method, and the density according to the present invention was measured in accordance with JISP 8118 by peeling off each layer at the final papermaking finishing stage. Things. The density of the top layer is the ink-jet recording is performed, preferably 0.7~0.9g / cm ^3, the middle layer, the density of the lowermost layer, 0.2 to 0.8 g / cm ³
It is preferable that

If the density of the uppermost layer exceeds 0.9 g / cm ³ , there is a problem that paper swells during papermaking, and
Poor ink absorbency and drying properties. 0.7g / cm density
^If it is less than ³ , the rigidity is low and not suitable for practical use,
There is a problem that ink spreads. When the density of the middle layer and the lowermost layer exceeds 0.8 g / cm ³ , it is difficult to obtain a bulky texture, and when the density is less than 0.2 g / cm ³ , the paper quality becomes hard to withstand use, and various processes and ink jet printing are performed. During printing, delamination or wrinkling of the product, a problem called so-called emi, occurs.

Further, in the present invention, the following techniques can be suitably used as means for adjusting the density of each of the uppermost layer, the middle layer, and the lowermost layer. (1) Each layer, especially the middle layer and the lower layer, preferably contains 30 to 200 kg / t of heat-foamable microcapsules.
The heat-expandable microcapsules used in the present invention are obtained by encapsulating a low-boiling solvent in the outer shell of fine particles of thermoplastic synthetic resin, and have an average particle diameter of 5 to 130 times, and an average particle diameter of 5 to 130 times.粒子 30 μm particles. The amount of the thermally expanded particles is 1 to 20 parts by weight, preferably 3 to 20 parts by weight, based on 100 parts by weight of the pulp. If the amount is less than 1 part by weight, there is almost no effect on lowering the density, and if it exceeds 20 parts by weight, the paper interlayer strength is reduced and the economic efficiency is poor.

As the thermoplastic synthetic resin constituting the outer shell, copolymers such as vinylidene chloride, acrylonitrile, acrylates and methacrylates are usually used, and low boiling halogenated hydrocarbons, methylsilane and the like can be used. .

The heat-expandable microcapsules are heated to a temperature higher than the softening point of the thermoplastic synthetic resin constituting the outer shell, and are simultaneously vaporized with a low-boiling solvent (preferably having a boiling point of 80 ° C. or lower). The pressure increases and the outer shell expands to form closed cells.

As the heat-expandable microcapsules, Matsumoto Oil & Fats Co., Ltd. Matsumoto Crosssphere F-30D,
F-30GS, F-20D, F-50D, F-80D
And Expancel WU of Nippon Philite Co., Ltd.
U and the like are known, but not limited thereto. (2) Bulk-forming pulp is used for each layer, especially the middle layer and the bottom layer. As the bulk-forming pulp, a mercerized pulp obtained by swelling fibers by treating the pulp with caustic soda, and a cotton linter pulp obtained by carefully treating short hairs attached to cotton can be suitably used. (3) A bulking agent is added to each layer or, desirably, to one of the middle layer and the bottom layer. Sofon (manufactured by BASF), Sulsol (manufactured by Kindai Kagaku), and KB115 (manufactured by Kao) having an effect of expressing bulk can be suitably used.
The bulking agent is preferably added in an amount of 0.3 to 1.0% by weight based on the pulp.

In addition to the above techniques, the bulk can be more suitably adjusted by lowering the wet paper web press pressure during papermaking, lowering the finishing calender pressure, and adjusting the water content.

The use of pulp which can be mixed with heat-foamable microcapsules and which can obtain a bulk is most preferably used for the middle layer and the lower layer from the viewpoint of ink receptivity.

More preferably, the uppermost layer of the multi-layer base paper,
Alternatively, at least one of the middle and lower layers contains 5 recycled pulp.
0% by weight or more is used.

By using 50% by weight or more of the recycled pulp in the structure of the target layer, the reproducibility of the recorded image is improved. Further, since the layer swells little due to water absorption, the sharpness is good when an ink jet recorded image is formed.

When the short fibers obtained by mechanically classifying the recycled pulp are blended in each layer, the long fibers which cause formation deterioration can be relatively reduced. Specifically, the classification of the pulp is 42 as the fiber length of the pulp after the classification.
15-45% mesh residue, 150-400C freeness
It is preferable for the definition to be SF.

Recycled pulp used in the uppermost layer, the middle layer, and the lower layer includes, for example, upper white, ruled white, card, special white, medium white,
Imitation, Kent, white art, newspapers and the like. Two or more of these pulp may be used.

The pigments contained in the multi-layer base paper of the present invention include silica, colloidal silica, silicon oxide, zinc oxide, alumina, kaolin, calcined kaolin, clay, talc, calcium carbonate, barium sulfate, magnesium carbonate, and silicic acid. Examples thereof include calcium, aluminum hydroxide, titanium dioxide, zinc white, and their modified products, and organic pigments such as polystyrene and urea.

The average particle diameter of the pigment is about 0.05 to 20 μm, preferably 0.2 to 10 μm, as measured by an electron microscope. In particular, calcium carbonate and colloidal silica are preferred in terms of ink drying properties and absorbency.

Examples of the calcium carbonate include synthetic aragonite-based and calcite-based light calcium carbonate, and heavy calcium carbonate obtained by pulverizing and classifying natural calcium carbonate. preferable.

The colloidal silica is preferably a cation-modified non-spherical colloidal silica, which is coated with a hydrated metal oxide such as hydrated aluminum hydroxide, hydrated zirconium hydroxide, or hydrated tin hydroxide as a cation modifier.
Cation-modified non-spherical colloidal silica is preferably used, and in particular, cation-modified with hydrous aluminum hydroxide is preferably used.

The amount of the pigment to be contained in each layer of the multi-layer base paper in the present invention is useful in a range of 5 to 60% by weight in solid content based on the pulp contained in the layer. When the pigment amount is small, the ink receptivity is poor, the drying property of the ink-recorded image is deteriorated, and the reproducibility of the image is reduced. On the other hand, when the pigment amount is too large, the base paper strength is reduced. Is fragile, and powder dropping tends to worsen.

Each layer of the multi-layer base paper in the present invention includes:
Various polymers may be contained for the purpose of improving the drying property, water absorption, sharpness of an image and the like of the ink. Specific examples of such polymers include lime-processed gelatin, acid-processed gelatin, enzyme-processed gelatin, and gelatin derivatives such as various gelatins such as phthalic acid, maleic acid, and gelatin reacted with dibasic acid anhydrides such as fumaric acid. Ordinary polyvinyl alcohols having various degrees of saponification, carboxy-modified, cationic-modified and amphoteric polyvinyl alcohols and their derivatives, starches such as oxidized starch, cationized starch, etherified starch, and carboxymethyl cellulose.
, Cellulose derivatives such as hydroxyethylcellulose, polyvinylpyrrolidone, polyvinylpyridium halide, sodium polyacrylate, methacrylic acid copolymer salt, polyethylene glycol, polypropylene glycol, polyvinyl ether, alkyl vinyl ether and maleic anhydride copolymer. Copolymers, styrene / maleic anhydride copolymers and salts thereof, synthetic polymers such as polyethyleneimine, styrene / butadiene copolymers, conjugated diene-based copolymer latex such as methyl methacrylate / butadiene copolymer, polyvinyl acetate, Vinyl acetate polymer latex such as vinyl acetate / maleic acid ester copolymer, vinyl acetate / acrylic acid ester copolymer, ethylene / vinyl acetate copolymer, acrylic acid ester polymer, meta Acrylic acid ester polymers, ethylene
Acrylic ester copolymer, acrylic polymer or copolymer latex such as styrene / acrylic ester copolymer, latex of vinylidene chloride copolymer, or functional groups such as carboxyl group of these various polymers Functional group-modified polymer latex by monomer,
Aqueous adhesives such as thermosetting synthetic resins such as melamine resin and urea resin, and synthetic resin adhesives such as polymethyl methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride / vinyl acetate copolymer, polyvinyl butyral, and alkyd resin And these can be contained alone or in combination. The amount of the polymer used is 0.5 to 100 parts by weight of the solid content of the pulp in the layer to which the base paper is added.
A range of 50 parts by weight is useful, but a range of 5 to 30 parts by weight is preferred.

Each layer of the multi-layer base paper in the present invention includes:
Various additives can be contained in addition to the pigment, the polymer, and the surfactant. For example, silane coupling agents such as γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, and polymer hardeners include active halogen compounds, vinyl sulfone compounds, aziridine compounds, and epoxy resins. Compounds, acryloyl compounds, hardening agents such as isocyanate compounds, preservatives such as p-hydroxybenzoic acid ester compounds, benzisothiazolone compounds, isothiazolone compounds, coloring dyes, fluorescent whitening agents, etc., and hydroxymethanesulfonic acid as a yellowing inhibitor Soda, sodium p-toluenesulfinate and the like, ultraviolet absorbers such as benzotriazole compounds having a hydroxy-di-alkylphenyl group at the 2-position, and antioxidants such as polyhindered phenol compounds and organopolysiloxanes. San compound, as a pH adjusting agent, sodium hydroxide, sodium carbonate, sulfuric acid, hydrochloric acid, phosphoric acid, and citric acid can be incorporated in combination octyl alcohol, various additives such as silicon-based defoaming agent as appropriate.

The absolute dry weight of the multi-layer base paper of the present invention is not particularly limited, but is preferably from 30 to 250 g / m ² , and particularly preferably the absolute dry weight of the uppermost layer is from 10 to 100 g / m ² .

Next, the stock chiller to which the internal chemicals are added is formed by multi-layer making so that a uniform formation can be obtained by a conventionally used paper machine such as a fourdrinier machine or a round mesh machine. After papermaking, the paper is subjected to calendering using a machine calender, a super calender, a heat calender, or the like, to produce a base paper having a Beck smoothness of 50 seconds or more, preferably 100 seconds or more.

[0036]

EXAMPLES Next, examples will be described in order to more specifically explain the present invention. Of course, the present invention is not limited to only these examples. In the examples, parts and%
Represents parts by weight and% by weight unless otherwise specified.

[Adjustment of recycled pulp] Waste paper is mechanically classified,
Recycled pulp of 150 to 400 CSF was obtained.

The recycled pulp and the hardwood bleached kraft pulp are mixed at different mixing ratios, the uppermost, middle, and lowermost raw pulp is adjusted, and an auxiliary agent such as a pigment and a sizing agent is appropriately added thereto to form an ink jet. Recording paper was made.

Example 1 Recycled pulp and mercerized pulp derived from waste magazine paper were used for 70:
The uppermost layer mixed at a ratio of 30; the recycled pulp derived from used white paper, the LBKP and the mercerized pulp mixed at a ratio of 30:50:20, and the thermal foamed resin added at 10% by weight; the recycled pulp derived from waste magazine paper And mercerized pulp 70: 3
The lower layer containing 20% by weight of a thermofoamable resin and 30 kg / ton of a bulking agent (SOFNON) was mixed together to form a base paper for inkjet recording paper. Upper layer 0.9g / c
m ³ , middle layer 0.7 g / cm ³ , bottom layer 0.8 g / cm ³
Was obtained.

Example 2 Recycled pulp derived from recycled old paper, LB and LB derived from Kamishira waste paper were mixed with recycled pulp derived from waste magazine paper, LBKP and mercerized pulp at a ratio of 30:50:20, and added with 3% by weight of a thermal foaming resin.
KP and mercerized pulp are mixed at a ratio of 60:20:20, the thermally foamed resin is 30% by weight, and the bulking agent (Sulsol) 4 is used.
The middle layer to which 0 kg / ton was added, the lower layer in which recycled pulp derived from old magazine paper, LBKP and mercerized pulp were mixed at a ratio of 70:10:20, and the respective layers were combined to form an inkjet recording paper base paper. The density is 0.7 g / cm ^{3 for} the uppermost layer, 0.8 g / cm ^{3 for} the middle layer, and 0.
8 g / cm ³ of ink jet recording paper was obtained.

Example 3 Recycled pulp derived from used paper, LBKP, and mercerized pulp were mixed at a ratio of 60:30:10, and 5% by weight of a thermal foaming resin was added.
KP and mercerized pulp were mixed at a ratio of 40:30:30, and 5% by weight of a thermally foamed resin and a bulking agent (Sulsol) 30 were used.
The middle layer to which kg / ton was added, the recycled pulp derived from old magazine paper, the LBKP, and the mercerized pulp were mixed at a ratio of 40:50:10, and 10% by weight of the thermal foaming resin and 100 kg / ton of bulking agent (Sulsol) were added. The lower layer and the respective layers are combined to form an ink jet recording paper base paper, and the base paper density is 0.8 g / cm ^{3 for the} uppermost layer and 0.6 g / cm for the middle layer.
^3. An ink jet recording paper having a lowermost layer of 0.6 g / cm ³ was obtained.

Example 4 The uppermost layer obtained by mixing recycled pulp derived from waste magazine paper and LBKP at a ratio of 70:30, and the recycled pulp derived from waste newspaper and mercerized pulp were mixed at a ratio of 80:20. Recycled pulp, LBKP, and cotton linter pulp derived from waste media paper mixed with 10% by weight of a middle layer are mixed at 50: 40: 1.
And the lowermost layers containing 5% by weight of the thermally foamed resin and 200 kg / ton of bulking agent (Sulsol) were mixed together to form a base paper for inkjet recording paper, and the base paper density was 0.75 g for the uppermost layer. / Cm ³ , middle layer 0.8 g / c
m ³ , an ink jet recording paper having a lowermost layer of 0.7 g / cm ³ was obtained.

Example 5 Recycled pulp derived from waste magazine paper and LB mixed with recycled pulp derived from used magazine paper, LBKP and mercerized pulp at a ratio of 80:10:10, and 1% by weight of a thermofoam resin were added.
KP and mercerized pulp were mixed at a ratio of 70:20:10, and 3% by weight of a thermally foamed resin and a bulking agent (Sulsol) 3
0 kg / ton added was lowest layer was papermaking ink jet recording base paper Shi combined paper making, respectively, the base paper density was obtained top layer 0.8 g / cm ^3, the ink jet recording paper of the lowermost 0.75 g / cm ^3.

Comparative Example 1 The uppermost layer obtained by mixing recycled pulp derived from waste magazine paper, LBKP and mercerized pulp at a ratio of 40: 55: 5, and recycled pulp derived from Kamishira paper, LBKP and mercerized pulp in 5 parts.
The mixture was mixed at a ratio of 0: 45: 5, and a middle layer containing 2% by weight of a thermally foamed resin and 10 kg / ton of a bulking agent (Sulsol), and a recycled pulp derived from waste magazine paper and LBKP mixed at a ratio of 40:60. The lower layers are laminated together to form an inkjet recording paper base paper, and the base paper density is 0.6 g / c in the uppermost layer.
m ³ , middle layer 0.7 g / cm ³ , bottom layer 0.6 g / cm ³
Was obtained.

Comparative Example 2 Recycled pulp derived from waste magazine paper and LB mixed with recycled pulp derived from waste magazine paper and LBKP at a ratio of 30:70.
KP is mixed at a ratio of 40:60, and a middle layer to which 20 kg / ton of a bulking agent (sulsol) is added, recycled pulp derived from waste newspaper, LBKP and mercerized pulp are mixed at 50: 45: 5.
And the lowermost layers to which 3% by weight of the thermofoaming resin and 20 kg / ton of bulking agent (Sulsol) are added are mixed together to form an inkjet recording paper base paper, and the base paper density is 0.55 g / top layer. cm ³ , middle layer 0.6 g / c
m ³ , an ink jet recording paper having a lowermost layer of 0.7 g / cm ³ was obtained.

Comparative Example 3 Recycled pulp derived from waste magazine paper, LBKP and mercerized pulp were mixed at a ratio of 10:80:10, and recycled pulp derived from imitation waste paper and LBKP were mixed at a ratio of 30:70. The middle layer to which 250 kg / ton of bulking agent (Sulsol) was added, recycled pulp derived from old newspaper, LBKP and mercerized pulp were mixed at a ratio of 60:20:20, and 20% by weight of the thermal foaming resin was added to the bulking agent (Sulsol). The lowermost layers to which 10 kg / ton was added were mixed together to form an ink jet recording paper base paper, and the base paper density was 0.5 g / top layer.
cm ³ , middle layer 0.55 g / cm ³ , bottom layer 0.9 g / c
to obtain an ink jet recording paper of m ^3.

Comparative Example 4 Recycled pulp derived from old magazine paper, LBKP and mercerized pulp were mixed at a ratio of 50: 45: 5, and the uppermost layer to which 5% by weight of a thermally foamed resin was added, and 300 kg / ton of bulking agent was added to LBKP. The lowermost layers are laminated together to form a base paper for inkjet recording paper, and the density of the base paper is 0.7 g / cm for the uppermost layer.
^3. An ink jet recording paper having a lowermost layer of 0.5 g / cm ³ was obtained.

Comparative Example 5 Inkjet recording paper base paper was made from a single layer in which LBKP and mercerized pulp were mixed at a ratio of 90:10 to obtain an ink jet recording paper having a base paper density of 0.6 g / cm ³ .

Table 1 shows the results obtained by the following evaluation methods. Water absorption: Black solid printing was performed on the uppermost layer of the ink jet recording paper by an ink jet printer, and immediately after printing, the presence or absence of ink transfer to a finger was determined. Drying property: Solid printing of black, magenta, yellow, and blue is performed on the uppermost layer of the ink jet recording paper by an ink jet printer, and the printing portion of each color is ink jet recorded and rubbed with a finger after 30 minutes to dry the image. Was visually determined. Image reproducibility: 0.25 point white line images were drawn on black solid printing portions at 1 mm intervals, and the sharpness of the image portions was visually determined. The evaluation criteria of the quality test are as follows. ：: No problem and excellent. ：: good. Δ: Within the practical limit. X: Poor.

[0050]

[Table 1]

From the results in Table 1, it can be seen that the ink jet recording paper of the present invention, which is the base paper of Examples 1 to 5, has good water resistance, drying properties and image reproducibility, while the ink jet recording paper of Comparative Examples 1 to 5 It can be seen that the recording paper is inferior in water resistance, drying properties, and image reproducibility.

[0052]

According to the present invention, it is possible to provide an excellent ink jet recording paper having high water absorption, quick drying of ink, and good reproducibility of an ink image.

Claims (5)

[Claims] 1. The base paper is a multi-layer base paper manufactured by a laminating method, wherein the density of the uppermost layer of the multi-layer base paper is 0.7.
0.9 g / cm ³ , and the density of the middle layer and the lowermost layer is 0.1 g / cm ³ .
An ink jet recording paper having a weight of 2 to 0.8 g / cm ³ . 2. The ink jet recording paper according to claim 1, wherein at least one of the middle layer and the lowermost layer of the multi-layer base paper contains heat-expandable microcapsules. 3. The ink jet recording paper according to claim 1, wherein at least one of the middle layer and the lowermost layer of the multi-layer base paper contains 20 to 30% by weight of a bulk pulp. 4. The ink jet recording paper according to claim 2, wherein at least one of the middle layer and the lowermost layer of the multi-layer base paper contains a bulking agent. 5. The ink-jet recording paper as claimed in claim 1, wherein recycled pulp is contained in an amount of 50% by weight or more as a raw material pulp for the multi-layer base paper.