JP2000094827A - Ink jet recording paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an ink jet recording paper friendly with the environment and generating only a few bleeding phenomenons along fibers and bleedings on the printing boundary sections of different colors. SOLUTION: Bagasse pulp is used as a pulp raw material, and the printing ratio of the bagasse pulp to the total pulp quantity is set as 70% or less and desirably a paper using a neutral rosin sizing agent as a sizing agent is introduced therein, and 30 second cup water absorption degree measured by 5% isopropyl alcohol water solution is 14-25 g/m2.

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. More specifically, it relates to environmentally friendly ink jet recording paper, which uses bagasse pulp as base paper and prints with an ink jet printer, which causes less ink bleeding along the fibers and bleeding at the printing boundary between different colors. It is.

[0002]

[Prior art]

[0003] In recent years, from the viewpoint of environmental protection, use of used paper in various papers has been studied. As the use of waste paper has progressed, alkaline substances such as calcium carbonate have been mixed in papermaking systems conventionally produced in an acidic region, and the pH of the papermaking system has been increasing.
As a result, the pH of the papermaking system increases, and the activity of the sulfate band used in the acidic papermaking system decreases. As the activity of the sulfate band decreases, the problem that the sizing property of the paper decreases tends to occur. Thus, paper that has been conventionally made in an acidic region is now being made in a neutral to alkaline system, with the help of using calcium carbonate, which is an inexpensive filler.

[0004] When making paper with a neutral to alkaline system,
Alkyl ketene dimer or alkenyl succinic anhydride is used as a sizing agent, but there are still problems in controllability of sizing property and stains in the papermaking system during papermaking.

[0005] As the utilization rate of waste paper increases, waste paper is used even on paper that has not been used, and the waste paper itself tends to be insufficient. Therefore, the use of non-wood plant resources such as kenaf and bagasse is also attracting attention. In particular, bagasse (sugar mill squeezed waste) formed at the end of the sugar production process has attracted attention from the viewpoint of its effective use. However, paper using these non-wood plant resources has only been used as offset printing paper for small quantity printing.

On the other hand, when looking at recent printing methods,
Compared with the conventional offset printing method, a printing machine for personal use which is inexpensive and maintenance-free has been developed. As a printing method of these printing machines, an ink jet method and an electrophotographic method are often used. In particular, the development of an ink jet printing machine has been remarkable in terms of space saving and low cost. At the same time, multi-color and full-color prints are becoming more common than conventional monochrome one-color printing.

Regarding the characteristics of paper using bagasse pulp as described above, for example, as described in the Paper Pulp Technology Times, July 1998, p. Although it is known that the air permeability increases, at present, utilization in the field of ink-jet paper has hardly been known in terms of ink-jet suitability.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet printer using bagasse pulp for base paper, which causes bleeding of ink along fibers and bleeding at a printing boundary between different colors. It is intended to provide an environmentally friendly ink jet recording paper with less ink.

[0009]

The present inventors have conducted intensive studies to solve the above-mentioned drawbacks, and as a result, have come to invent the ink jet recording paper of the present invention.

That is, in the ink jet recording paper of the present invention, bagasse pulp is used as a pulp raw material, and a paper in which the mixing ratio of bagasse pulp to the total pulp content is 70% or less is used as base paper, and 30 seconds measured with a 5% isopropyl alcohol aqueous solution. It is characterized by having a Cobb water absorption of 14 to 25 g / m ² . Further, the invention is characterized in that a neutral rosin sizing agent is used as an internal sizing agent when the base paper is made.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the ink jet recording paper of the present invention will be described in detail.

First, the present inventors have studied the relationship between inkjet suitability and sizing degree. When printing with an inkjet printer, if the permeability of the ink to the inkjet recording paper is too high, the print density may not be sufficient or the ink may bleed along the fibers on the surface of the inkjet recording paper (such a case). The phenomenon is hereinafter referred to as feathering). On the other hand, if the penetrability of the ink into the ink jet recording paper is too low, when different colors are adjacent to each other, the inks are mixed with each other at the boundary line and appear to bleed (this phenomenon will be described below). This is called bleeding). Therefore, it is necessary that the ink jet recording paper has such a size that the ink permeates into the paper appropriately. However, conventionally, when inkjet recording paper was manufactured using an index based on the degree of Stekigt sizing such as measuring paper sizing property or the Cobb's water absorption using water as an index, the inkjet quality could not be sufficiently controlled. .

[0013] The reason for this is that the ink used in an ink jet printer has a higher permeability to paper than water, and the permeation behavior into ink jet recording paper is different from that of water. . Therefore, the present inventors have conducted intensive studies and found that it is necessary to use a liquid having a composition close to the ink of an ink jet printer when evaluating the permeability of the ink into the ink jet recording paper. The 30-second Cobb water absorption measured with a 5% isopropyl alcohol aqueous solution can be used as an index of the size of the ink jet recording paper, and the 30-second Cobb water absorption measured with a 5% isopropyl alcohol aqueous solution of the ink jet recording paper is 14 to 25 g / m. ^By controlling to ² , it was found that an ink jet recording paper with little feathering and bleeding can be provided when printing with an ink jet printer.

The 30-second Cobb water absorption of ink-jet recording paper measured with a 5% aqueous isopropyl alcohol solution is 1
If it is less than 4 g / m ² , the size of the ink jet recording paper is too high, and feathering is good, but bleeding is deteriorated.

The 30-second Cobb water absorption of the ink jet recording paper measured with a 5% aqueous isopropyl alcohol solution was 2
When the amount is more than 5 g / m ² , the size of the ink jet recording paper is too low and the bleeding is good, but the feathering is poor and the print density does not increase.

Means for controlling the sizing properties of the ink jet recording paper of the present invention include: adjusting the amount of an internal sizing agent, adjusting the amount of ash when manufacturing the ink jet recording paper; A method of applying a water-soluble binder such as oxidized starch or PVA can be used. A styrene / acrylic acid copolymer, a styrene / methacrylic acid copolymer, an acrylonitrile / vinyl formal / acrylic ester copolymer, and a styrene / maleic acid copolymer are used together with a water-soluble binder such as oxidized starch and PVA. It is effective to use a surface sizing agent such as a polymer in combination.

Next, the present inventors examined the relationship between the amount of bagasse pulp and the suitability for inkjet. Bagasse pulp is composed of long fiber components originating from vascular sheath fibers and short non-fibrous cells, and has a wider fiber length distribution width than hardwood pulp used for ordinary high quality paper. Further, paper made using bagasse pulp generally tends to have poor air permeability.

From the viewpoint of ink jet suitability, it has been found that, when a paper containing bagasse pulp is viewed, the air permeability of the paper deteriorates, the drying property of the ink deteriorates, and the bleeding deteriorates. In addition, it has been found that long fibers tend to remain in the fibers constituting the paper surface, and that feathering is likely to occur. When the blending amount of bagasse pulp was small, the amount was measured with a 5% isopropyl alcohol aqueous solution by a method such as adjusting the amount of the internal sizing agent, the amount of the ash, and applying a water-soluble binder or a surface sizing agent to the surface of the inkjet recording paper. 30-second Cobb water absorbency 14-2
Feathering and bleeding can be improved by adjusting to 5 g / m ² .

However, if the content of bagasse pulp exceeds 70% of the total pulp content, the air permeability becomes extremely poor and the long fiber content increases, so that the sizing control as described above occurs. It has been found that the improvement of feathering and bleeding is insufficient with the method alone.

As described above, paper having a bagasse pulp content of 70% or less based on the total pulp content is used as base paper.
By setting the 30-second Cobb water absorption measured with a 5% aqueous isopropyl alcohol solution to 14 to 25 g / m ² , it is possible to provide an ink jet recording sheet having good feathering and bleeding.

Although the compounding ratio of bagasse pulp of the base paper of the ink jet recording paper of the present invention is 70% by weight or less, from the viewpoint of the environment, it is better to reduce the compounding ratio of wood pulp as much as possible. Then, a paper blended with a blending ratio of bagasse pulp in the range of 30 to 70% by weight based on the total amount of pulp is used as base paper so that the 30-second Cobb water absorption measured with a 5% isopropyl alcohol aqueous solution is 14 to 25 g / m ^2. By doing so, it is possible to provide an environment-friendly inkjet recording sheet with good feathering and bleeding.

Finally, the present inventors studied the control of the size of the ink jet recording paper of the present invention. As described above, in order to provide an ink jet recording sheet with little feathering and bleeding, it is necessary to finely control the size of the ink jet recording sheet. In particular, control of ink absorption in the thickness direction of paper becomes important. Conventionally, when making a neutral paper, it is made using a pulp slurry in a pH range of a neutral to alkaline range. Alkyl ketene dimers and alkenyl succinic anhydrides have been used as internal sizing agents that have been used when making neutral paper.

The alkyl ketene dimer and the alkenyl succinic anhydride have extremely high sizing properties with respect to the amount added to the pulp as compared with rosin sizing agents conventionally used in acidic papermaking systems. However, the change in sizing property with respect to the change in the amount added to the pulp was rapid, and it was difficult to control the sizing property. On the other hand, the rosin sizing agent used in the acidic papermaking system did not exhibit sizing properties in the papermaking system in the neutral to alkaline region.

Thus, the present inventors have found that a neutral rosin sizing agent is effective as an internal sizing agent when the base paper of the ink jet recording paper of the present invention is formed.
The neutral rosin sizing agent in the present invention refers to, for example, a sizing agent as described in Journal of the Japanese Association of Paper Technology, Vol. 47, No. 5, p. 31-34 (1993). The neutral rosin sizing agent is an emulsion type rosin sizing agent comprising rosin as a raw material, esterified rosin, and an emulsifier.

The amount of the neutral rosin sizing agent to be added when the base paper of the ink jet recording paper of the present invention is formed is desirably 0.1 to 0.5% by weight based on pulp. When a neutral rosin sizing agent is used, a certain amount of sulfate band is required for the expression of sizing properties.
2.0% by weight is desirable.

As described above, the blending ratio of bagasse pulp with respect to the total amount of pulp is 70% by weight or less, and a paper using a neutral rosin sizing agent as an internal size is used as a base paper for 30 seconds measured with a 5% isopropyl alcohol aqueous solution. By setting the Cobb water absorption to 14 to 25 g / m ² , it is possible to provide an ink jet recording sheet with less feathering and bleeding.

Examples of the internal filler used for producing the ink jet recording paper of the present invention include kaolin and clay in addition to light calcium carbonate and heavy calcium carbonate.

The ash content of the ink jet recording paper of the present invention is preferably in the range of 3 to 20% by weight. More preferably, the content is 5 to 15% by weight.

On the surface of the ink jet recording paper of the present invention, a binder such as starch and polyvinyl alcohol, a dimensional stabilizer such as ethylene-urea resin, an inorganic conductive agent such as sodium chloride and potassium chloride, an organic conductive agent, a surface active agent It is of course possible to apply agents, pigments and dyes.

As a device for applying the above binder and surface sizing agent, a conventional size press, a gate roll size press, a film transfer type size press, a rod coater, a bill blade, a short dwell coater and the like can be used. it can. Among these coating devices, it is desirable to use a system in which the inside of the paper layer is impregnated with the above-mentioned size press liquid.

The pulp usable for producing the neutral paper of the present invention includes NBKP, LBKP, NBSP and LB.
In addition to SP, GP, TMP and the like, used paper pulp is used, and used alone or in combination as needed.

The raw materials of the used paper pulp referred to in the present invention include, for example, top white, ruled white, cream white, card, and the like shown in the used paper standard quality standard table of the used paper recycling promotion center.
Special white, medium white, imitation, fair white, Kent, white art, special top cut,
Another example is newspaper, magazine, etc. Further specific examples include uncoated computer paper, which is information-related paper,
Printer paper such as thermal paper, pressure-sensitive paper, and OA waste paper such as PPC paper, coated paper such as art paper, coated paper, lightly coated paper, matte paper, or fine paper, color fine, notebook,
Used paper such as stationery, wrapping paper, fancy paper, medium paper, newsprint, paper change, super-hanging paper, imitation paper, pure white roll paper, uncoated paper such as milk carton, etc.
Chemical pulp paper, high-yield pulp-containing paper and the like are used, but are not particularly limited regardless of printing, copying, printing, and non-printing.

Other additives 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 preventive.

The ink jet recording paper of the present invention can be used not only as ink jet recording paper but also as offset printing paper, transfer paper for electrophotography, and thermal transfer image receiving paper.

[0035]

The present invention will be described below with reference to examples of the present invention, but the present invention is not limited to these examples. Further, “parts” and “%” shown in Examples are
Unless indicated otherwise, parts by weight and% by weight are indicated.

Example 1 First, a pulp slurry was prepared according to the following base paper composition. <Base paper composition> LBKP (freeness: 450 ml) 95 parts Bagasse pulp (freeness: 450 ml) 5 parts Calcium carbonate (manufactured by Okutama Industry Co., Ltd .; Tamapearl TP121) 7 parts Sulfuric acid band 0.5 parts Cationized starch (Nisseki Chemical) Exel No. 4) 1.0 part Alkyl ketene dimer (Arakawa Chemical; Size Pine K-903) 0.08 parts Yield improver (HIMO; NR11LS) 0.02 parts

A base paper was manufactured from a 0.5% by weight pulp slurry having the above composition at a papermaking width of 1500 mm and a papermaking speed of 200 m / min using a fourdrinier paper machine. A size press liquid having the following composition was applied to the base paper. <Composition of size press liquid> Oxidized starch (manufactured by Nippon Food Processing Co., Ltd .; MS3800) 3 parts Surface sizing agent (Harima Chemical Co., Ltd .; KN-500) 0.2 parts Water 96.8 parts

As described above, an ink jet recording sheet having a basis weight of 64 g / m ² , a density of 0.75 g / cm ³ and a water content of 5.0% was obtained.

Example 2 LBKP (freeness: 450 ml) 85 in Example 1
Ink-jet recording paper of Example 2 was prepared in the same manner except that 15 parts by weight and 15 parts of bagasse pulp (freeness: 450 ml) were used.

Example 3 In Example 1, LBKP (freeness: 450 ml) 70
Inkjet recording paper of Example 3 was prepared in the same manner except that 30 parts by weight of bagasse pulp (freeness: 450 ml) was used.

Example 4 In Example 1, LBKP (freeness; 450 ml) was 50.
Inkjet recording paper of Example 4 was prepared in the same manner except that 50 parts by weight and bagasse pulp (freeness: 450 ml) were used.

Example 5 In Example 1, LBKP (freeness: 450 ml) 30
Inkjet recording paper of Example 5 was prepared in the same manner except that 70 parts by weight of bagasse pulp (freeness: 450 ml) was used.

Example 6 In Example 1, LBKP (freeness: 450 ml) 70
Parts, bagasse pulp (freeness: 450 ml) 30 parts,
An ink jet recording paper of Example 6 was produced in the same manner except that the internal sizing agent was changed to 0.10 parts of alkenyl succinic anhydride (manufactured by Seiko Chemical Co .; Coropearl Z100).

Example 7 In Example 1, LBKP (freeness: 450 ml) 30
Parts, 70 parts of bagasse pulp (freeness: 450 ml)
An ink jet recording paper of Example 7 was produced in the same manner except that the internal sizing agent was 0.10 parts of alkenyl succinic anhydride (manufactured by Seiko Chemical Co .; Coropearl Z100).

Example 8 In Example 1, LBKP (freeness: 450 ml) 85
Parts, 15 parts bagasse pulp (freeness; 450 ml)
An ink jet recording sheet of Example 8 was prepared in the same manner except that the sulfuric acid band was 1.2 parts and the internal sizing agent was a neutral rosin sizing agent (NT85, manufactured by Arakawa Chemical Co .; NT85).

Example 9 In Example 1, LBKP (freeness: 450 ml) 70
Parts, bagasse pulp (freeness: 450 ml) 30 parts,
An ink jet recording paper of Example 9 was produced in the same manner as above except that the sulfuric acid band was 1.2 parts and the internal sizing agent was a neutral rosin sizing agent (NT85, manufactured by Arakawa Chemical Co., Ltd.).

Example 10 LBKP (freeness: 450 ml) of Example 1 was used.
Parts, 50 parts bagasse pulp (freeness; 450 ml)
An ink jet recording sheet of Example 10 was prepared in the same manner except that the sulfuric acid band was 1.2 parts and the internal sizing agent was a neutral rosin sizing agent (NT85, manufactured by Arakawa Chemical Co., Ltd.).

In Example 1, LBKP (freeness: 45
0 ml) 30 parts, bagasse pulp (freeness; 450 ml)
70 parts, a sulfuric acid band of 1.2 parts, and an internal sizing agent of a neutral rosin sizing agent (Arakawa Chemical Co .; NT85) 0.30
The same procedure as in Example 11 was carried out except that the ink jet recording paper was prepared.

Example 12 In Example 1, LBKP (freeness; 450 ml) was 50%.
Parts, 50 parts bagasse pulp (freeness; 450 ml)
An ink jet recording paper of Example 12 was prepared in the same manner except that the sulfuric acid band was changed to 1.2 parts and the internal sizing agent was changed to a neutral rosin sizing agent (NT85, manufactured by Arakawa Chemical Co., Ltd .; NT5).

Example 13 In Example 1, LBKP (freeness: 450 ml) 50
Parts, 50 parts bagasse pulp (freeness; 450 ml)
An ink jet recording paper of Example 13 was produced in the same manner except that the sulfuric acid band was 1.2 parts and the internal sizing agent was 0.25 parts of a neutral rosin sizing agent (Arakawa Chemical; NT85).

Example 14 In Example 1, LBKP (freeness: 450 ml) 50
Parts, 50 parts bagasse pulp (freeness; 450 ml)
9 parts of calcium carbonate, 1.2 parts of a sulfate band, and a neutral rosin sizing agent (Arakawa Chemical; NT8
5) An ink jet recording sheet of Example 14 was produced in the same manner except that the amount was 0.30 parts.

Example 15 LBKP (freeness: 450 ml) of Example 1 was used.
Parts, 50 parts bagasse pulp (freeness; 450 ml)
13 parts of calcium carbonate, 1.2 parts of sulfuric acid band, neutral rosin sizing agent (Arakawa Chemical; NT8
5) An ink jet recording paper of Example 15 was prepared in the same manner except that the amount was 0.30 parts.

Example 16 In Example 1, LBKP (freeness: 450 ml) 50
Parts, 50 parts bagasse pulp (freeness; 450 ml)
13 parts of calcium carbonate, 1.2 parts of sulfuric acid band, neutral rosin sizing agent (Arakawa Chemical; NT8
5) An ink jet recording sheet of Example 16 was produced in the same manner except that 0.35 parts was used.

Example 17 In Example 1, LBKP (freeness: 450 ml) 50
Parts, 50 parts bagasse pulp (freeness; 450 ml)
13 parts of calcium carbonate, 1.2 parts of sulfuric acid band, neutral rosin sizing agent (Arakawa Chemical; NT8
5) An ink jet recording sheet of Example 17 was prepared in the same manner except that 0.40 parts was used.

Example 18 In Example 1, 70 parts of waste paper pulp (freeness; 450 ml) and 30 parts of bagasse pulp (freeness: 450 ml) from high-quality PPC paper were used.
Neutral rosin sizing agent (Arakawa Chemical; N
T85) Example 1 was repeated in the same manner except that 0.30 part was used.
Inkjet recording paper No. 8 was produced.

Comparative Example 1 In Example 1, LBKP (freeness: 450 ml) 25
Ink-jet recording paper of Comparative Example 1 was prepared in the same manner except that 75 parts of bagasse pulp (freeness: 450 ml) was used.

Comparative Example 2 Bagasse pulp in Example 1 (freeness: 450 ml)
An ink jet recording paper of Comparative Example 2 was prepared in the same manner except that the amount was 100 parts.

Comparative Example 3 In Example 1, LBKP (freeness; 450 ml) 50
Parts, 50 parts bagasse pulp (freeness; 450 ml)
Inkjet recording paper of Comparative Example 3 was produced in the same manner except that 0.10 part of alkyl ketene dimer (manufactured by Arakawa Chemical Co .; size pine K-903) was used.

Comparative Example 4 In Example 1, LBKP (freeness: 450 ml) 50
Parts, 50 parts bagasse pulp (freeness; 450 ml)
An ink jet recording paper of Comparative Example 4 was prepared in the same manner except that 0.05 part of an alkyl ketene dimer (manufactured by Arakawa Chemical Co .; size pine K-903) was used.

Comparative Example 5 In Example 1, LBKP (freeness: 450 ml) 50
Parts, 50 parts bagasse pulp (freeness; 450 ml)
An ink jet recording sheet of Example 10 was prepared in the same manner except that the sulfuric acid band was 1.2 parts and the internal sizing agent was 0.40 parts of a neutral rosin sizing agent (Arakawa Chemical Co., Ltd .; NT85).

Comparative Example 6 In Example 1, LBKP (freeness: 450 ml) 50
Parts, 50 parts bagasse pulp (freeness; 450 ml)
Inkjet recording paper of Example 10 was produced in the same manner except that the sulfuric acid band was 1.2 parts and the internal sizing agent was 0.20 parts of a neutral rosin sizing agent (Arakawa Chemical Co., Ltd .; NT85).

The 30-second Cobb water absorption of the ink-jet papers of Examples 1 to 18 and Comparative Examples 1 to 6 measured with a 5% aqueous isopropyl alcohol solution was 5% as the solvent used for the measurement.
% Isopropyl alcohol, the contact time between the test piece and the solvent was 30 seconds, and the others were measured according to JIS P8140.

The inkjet suitability of the inkjet papers of Examples 1 to 18 and Comparative Examples 1 to 6 was evaluated in the following manner.

<Feathering> Characters and ruled lines were printed on the inkjet papers of Examples 1 to 18 and Comparative Examples 1 to 6 using a Canon printer “BJ-220JS”, and the degree of blurring of the characters and ruled lines was visually observed. Was evaluated according to the following criteria. The evaluation is a five-level evaluation, and if it is three or more, it is a practical level.

Evaluation criteria: "5" Very good. "4" Almost no ink bleeding along the fiber. "3" There are spots of ink bleeding along the fiber, but there is no problem. "2" Characters and ink bleeding along the fiber along the ruled lines are seen, and the character quality is poor. "1" Characters, ink bleeding along the fiber along the ruled lines are seen everywhere, and characters and the like are indistinguishable.

<Bleeding> Solid printing portions of black, cyan, magenta, and yellow were printed on the inkjet papers of Examples 1 to 18 and Comparative Examples 1 to 6 using a Canon printer “BJC-420J”. Then, a pattern is printed such that the solid printing section of each color is adjacent to the solid printing section of another color. The degree of bleeding at the boundary between adjacent colors was visually evaluated according to the following criteria.
The evaluation is a five-level evaluation, and if it is three or more, it is a practical level.

Evaluation criteria: "5" Very good. "4" Almost no bleeding between colors at the boundary. "3" There are some bleeding between colors at the borderline, but there is no problem. "2" The bleeding between the colors at the boundary line is clearly visible, and the boundary line is difficult to understand. "1" The bleeding between the colors at the boundary is severe, and the colors at the boundary are mixed, and the color at the boundary is discolored.

Tables 1 and 2 show the evaluation results of the ink-jet papers of Examples 1 to 18 and Comparative Examples 1 to 6.
Summarized in

[0069]

[Table 1]

[0070]

[Table 2]

Evaluation: In Tables 1 and 2, the ink jet recording papers obtained in Examples 1 to 18 and Comparative Examples 1 to 6 were mixed with bagasse, the type of sizing agent when the base paper was manufactured, and 5%. The ink jet aptitude, such as feathering and bleeding when printing with an inkjet printer, and the Cobb water absorption measured with an isopropyl alcohol aqueous solution were evaluated.

Comparing Examples 1 to 7 with Comparative Examples 1 and 2, it can be seen that feathering and bleeding of the ink jet recording paper of the present invention deteriorate as the amount of bagasse increases. Further, as a level that can be practically used, it is found that the compounding amount of bagasse pulp is 70% by weight or less.

When Examples 10, 12, and 13 were compared with Comparative Examples 5 and 6, the Cobb water absorption of the ink jet recording paper of the present invention measured with a 5% aqueous isopropyl alcohol solution was in the range of 14 to 25 g / m ^2. In this case, it was found that feathering and bleeding were good when printing was performed with an inkjet printer.

When comparing Example 4 with Comparative Examples 3 and 4, the inkjet recording paper of the present invention showed a Cobb water absorption of 14 to 25 g measured with a 5% aqueous isopropyl alcohol solution.
It can be seen that feathering and bleeding were good when printing was performed with an inkjet printer in the range of / m ² .

Comparison of Examples 1 to 11 shows that alkyl ketene dimer, alkenyl succinic anhydride and neutral rosin sizing agent can be used as the internal sizing agent used for the base paper of the ink jet recording paper of the present invention. At the same time, when Examples 2 to 7 and Examples 8 to 11 are compared, the neutral rosin sizing agent as the base paper of the ink jet recording paper of the present invention is more effective in feathering and bleaching than alkyl ketene dimer and alkenyl succinic anhydride. It turns out that reading is good.

A comparison between Example 4 and Examples 14 and 15 shows that the increase in ash content of the ink jet recording paper of the present invention slightly reduces feathering but improves bleeding. . Also, when increasing the ash content of the base paper, feathering is also possible if the Cobb water absorption measured with a 5% isopropyl alcohol aqueous solution is within the range of 14 to 25 g / m ^{2 when} the sizing of the inkjet recording paper of the present invention is reduced. It can be seen that bleeding can also provide good ink jet recording paper.

When Examples 15 to 17 are compared, even if the ash content of the ink jet recording paper of the present invention increases and the feathering slightly decreases, the feathering is also bleeding by controlling the size. It can also be seen that good ink jet recording paper can be provided.

Finally, comparing Example 9 with Example 18, it can be seen that the ink jet recording paper using both bagasse pulp and waste paper pulp has almost the same ink jet suitability as the ink jet recording paper using LBKP and bagasse pulp together.

[0079]

As described above, bagasse pulp is used as a raw material for pulp, the mixing ratio of bagasse pulp to the total pulp content is 70% by weight or less, and more preferably, a neutral rosin sizing agent is used as an internal sizing agent. The measured paper was used as a base paper and measured with a 5% isopropyl alcohol aqueous solution.
By setting the 0 second Cobb water absorption to 14 to 25 g / m ² , when printing with an ink jet printer, the bleeding phenomenon of ink along the fiber and the bleeding at the printing boundary between different colors are small. It is possible to provide an eco-friendly ink jet recording paper.

Claims (2)

[Claims] 1. A paper having a bagasse pulp content of 70% by weight or less based on the total amount of pulp is used as a base paper, and a 30-second Cobb water absorption measured with a 5% isopropyl alcohol aqueous solution is 14 to 25.
g / m ² . 2. The ink jet recording paper according to claim 1, wherein a neutral rosin sizing agent is used as an internal sizing agent when the base paper is made.