JPH11277883A - Recording medium and ink jet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain ink dots from extending, and form high quality images having no blotting and strike through by having a base paper containing kenaf pulp being subjected to interior application size treatment; however, not subjected to exterior application size treatment, and allowing a Stockigh sizing degree of the recording medium to be in a specific value or lower. SOLUTION: An ink receptor layer containing a pigment is provided on at least one of a base paper containing kenaf pulp, and the base paper is subjected to exterior application size treatment; however, not subjected to interior application size treatment, and a Stockigt sizing degree of the recording body is made 30 secs or lower for the production of a recording medium. The base paper used herein is made by a paper making machine after conducting an interior application of a fixer or the like to fix various kinds of interior application sizing agents for giving resistance relative to pulp material containing kenaf pulp and a fixer or the like to fix the sizing agent. A part of kenaf pulp constituting the base paper is preferable to be a mixture consisting of a woody part and base part of kenaf. Also, the recording medium is made of the order of 50-250 μm in thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium which retains the natural texture of kenaf paper and has excellent image characteristics, and ink jet recording which uses the recording medium to fly ink as droplets for recording. About the method.

[0002]

2. Description of the Related Art Ink-jet recording is a method in which fine droplets of ink are made to fly and adhere to a recording medium such as paper according to various operating principles to record images, texts, and the like. It has features such as operation with noise, easy multi-coloring, high flexibility of the recording pattern, and no development and fixing step. In recent years, it has been widely used not only for recording monochrome images composed of various figures including characters but also for recording full-color images. In addition, it is used not only for office equipment but also for various purposes such as industrial use or creation of art work, and is rapidly spreading.

[0003] The main constituent materials of the recording medium used in the ink jet recording system include not only so-called plain paper such as copy paper and bond paper made of ordinary wood pulp, but also various types of paper having an image forming layer on the surface. Various types are used, such as coated paper, transparent films for OHP made of synthetic resin, and fabrics formed of various fibers. Among these, the use of recording media such as plain paper has been remarkably increased with the spread of personal computers in recent years and office automation (OA).

Further, with the spread of the ink jet recording method as described above, the characteristics of the recording medium used in the ink jet recording method are also high-speed absorption and high absorption capacity of the ink, or image density and print quality when printing is performed. There is an increasing demand for improved print quality and, moreover, for improved water resistance of printed matter. In particular, the ink jet recording medium has both the property that the ink attached to the paper surface quickly penetrates into the paper and becomes apparently dry, and the property that the spread of the ink dots on the paper surface can be suppressed. It is necessary to be. In particular, when multi-color printing is performed by simultaneously attaching two or more different colors of ink to one point on the paper surface, or when high-speed printing is performed even in single-color printing, the ink penetrates into the paper quickly. Otherwise, the other ink will overlap the ink that first adheres to the paper,
A problem occurs in which the ink saturates on the paper surface and flows out, or the ink remaining on the paper surface causes contamination of a recording medium or the like while handling the paper on which the image is formed. Therefore, in such a case, a recording medium having good ink absorbency is required.

In response to such a request, Japanese Patent Laid-Open No. 55-5 / 55
No. 1583 discloses that a coating layer composed of amorphous silica and a polymer binder exhibits high ink absorbency for printing with an aqueous ink and is suitable for high-speed printing. Therefore, it seems effective to apply such a coating layer as an ink receiving layer of an inkjet recording medium.

In recent years, kenaf has attracted attention as an alternative to wood as a pulp material for papermaking. The kenaf pulp made from this kenaf is roughly classified into a trunk pulp obtained by pulping the whole wood and bast, a bast pulp obtained by pulping only the bast, and a wood pulp obtained by pulping only the wood. You. The kenaf paper containing kenaf pulp as a main material has a texture similar to that of Japanese paper, is bulky, has a large ink storage capacity, and is excellent in ink absorbency. Therefore, it is considered to be particularly suitable for the case of performing the above-described multi-color printing which requires a recording medium having excellent ink absorbency.

[0007]

However, paper (recording medium) having good ink absorbency, such as kenaf paper, generally causes bleeding or strike-through, and furthermore, the spread of ink dots on the paper surface. Therefore, there is another problem that the resolution of a recorded image is reduced, and thus there is a problem that the kenaf paper having ink absorbency and good image clarity has not been obtained. To improve these points, if an ink receiving layer is formed on the kenaf paper surface,
Certainly, ink jet recording characteristics such as ink absorbency and high-speed printing suitability can be improved, but in this case, a problem occurs in that the natural texture of kenaf paper is lost. Furthermore, when the ink receiving surface on which an image is formed is white, browning of black ink occurs,
There are also problems such as poor image quality when a full-color image is formed.

As a method of suppressing the spread of ink dots by improving the method of forming a recording medium, Japanese Patent Publication No. 60-275 discloses a method.
No. 88, while internally adding a wet paper strength agent, a base paper was formed substantially without sizing, and the surface thereof was coated with a coating solution, resulting in a Steckigt sizing degree (water resistance) of 3 seconds or less. An ink jet recording sheet configured as described above is described. However, this technique suppresses the spread of ink dots by giving a fine size to the paper surface, but according to the study of the present inventors, because of the fine size, uniform spread of the dots and There were drawbacks such as insufficient image density.

Accordingly, an object of the present invention is to provide a recording medium comprising kenaf paper as a base paper and having an ink receiving layer provided thereon, without impairing the feel of the kenaf paper serving as the base paper, and quickly removing the ink adhering to the paper surface. Penetration, and the spread of ink dots formed by ink droplets is suppressed,
An object of the present invention is to provide a recording medium capable of forming a high-quality image without bleeding or strike-through, particularly a full-color image, and an ink jet recording method using the recording medium.

[0010]

The above object is achieved by the present invention described below. That is, the present invention provides a recording medium in which an ink receiving layer containing a pigment is provided on at least one surface of a base paper containing kenaf pulp, wherein the base paper has an internally added size but is subjected to an externally added size treatment. A recording medium characterized in that the recording medium has a degree of Stiggent sizing of 30 seconds or less, and an ink jet recording method using the recording medium.

[0011]

Next, the present invention will be described in detail with reference to preferred embodiments. First, the base paper used in the present invention will be described. The base paper is made of kenaf pulp,
Any one may be used as long as it is contained. Accordingly, kenaf pulp alone may be used as a pulp raw material, or kenaf pulp and another type of pulp such as wood pulp may be used. Kenaf consists of a wood part and a bast part, but the characteristics of the wood part and the bast part are slightly different.Wood pulp consisting of the wood part has a short fiber and a large amount of lignin, whereas a bast part Bast pulp consisting of is long in fiber and low in lignin. When the woody part and the bast part are pulped together, the resulting pulp has properties in between.

In the present invention, any kenaf pulp can be used. In particular, it is preferable to use kenaf pulp obtained by appropriately adding bast pulp to woody pulp according to desired properties. That is, when woody chemical pulp using only the woody part of kenaf as a raw material is used, the obtained base paper has poor air permeability, and particularly when the recording medium of the present invention is used as an ink jet recording paper, the ink has an ink. Tends to be insufficiently absorbent.

The base paper used in the present invention contains kenaf pulp as described above.
The amount of kenaf pulp is preferably 10 to 100% by weight of the total pulp constituting the base paper, and more preferably 30 to 100% by weight from the viewpoint of the texture of kenaf. preferable. That is, if the amount of kenaf pulp in the base paper is less than 10% by weight, kenaf paper having a kenaf peculiar texture and color is impaired, which is not preferable.

Examples of the pulp which can be used together with the kenaf pulp at this time include, for example, ordinary pulp mainly containing conifers such as Akamatsu, Kuromatsu, Ezomatsu, Todomatsu and cedar, and broadleaf trees such as beech, hippo and Shinoki. Can be Further, those obtained by pulping them by any method may be used. For example, groundwood pulp, sulfite pulp, kraft pulp, semi-chemical pulp, chemical ground pulp, refiner ground pulp and the like can be used. Further, used paper pulp obtained by recycling can also be used. Further, in the recording medium of the present invention, in addition to these cellulose fibers, inorganic fibers such as glass fibers or synthetic fibers such as polyester fibers and aramid fibers can be used as needed. In the present invention, depending on the use of the recording medium, a base paper can be formed by using the above-mentioned materials alone, or by selecting a plurality of materials appropriately from these materials and using them together with kenaf pulp.

The base paper used in the recording medium of the present invention uses a pulp material containing kenaf pulp as described above, and
It is obtained by forming using the same method as in the case of producing paper made of ordinary wood pulp except that the external sizing treatment is not performed. That is, when producing the base paper used in the present invention, the internal size is applied in the same manner as in the normal case. This is because the strength of the base paper cannot be obtained when the internal size is not applied, and the strength becomes insufficient when the coating liquid is applied on the base paper to form the ink receiving layer. This is because troubles occur during coating. On the other hand, since no external sizing treatment has been performed, the wet permeability is good, and when the ink is applied, the ink can quickly penetrate into the base paper. In the recording medium of the present invention, the excessive ink penetration into the base paper which may be caused by not performing the externally added size processing is optimized by forming an ink receiving layer having a pigment on the base paper having the above configuration. To a state that is appropriate.

According to the study of the present inventors, an ink receiving layer containing a pigment is formed on at least one surface of the base paper having the above constitution, and the resulting recording medium has a Stigget sizing degree of 30 seconds or less. With this configuration, appropriate ink absorbency is realized, and the ink quickly penetrates into the base paper, and spread of ink dots on the paper surface is suppressed.
That is, unless the degree of Stekigt sizing is within 30 seconds, the ink does not quickly penetrate into the recording medium of the present invention, for example, when the ink is applied by an ink jet method. Phenomena such as beading occur, and a clear image having a high color density cannot be obtained. Therefore, the base paper used in the present invention can have a Steckigt sizing degree as small as possible, for example, 200, by appropriately selecting the material to be used and the forming method.
Seconds or less, and more preferably 15 seconds or less.
Preferably, it is formed so as to be 0 second or less. That is,
When the degree of Stekigt sizing of the base paper is larger than 200 seconds, penetration of the coating liquid into the base paper when the coating liquid is applied to the base paper surface to form an ink receiving layer is prevented,
Since it is difficult to form a good ink receiving layer, when printing is performed on the ink receiving surface, a tendency such as bleeding is likely to occur.

[0017] The base paper used has a Steckigt sizing degree of 30.
In the case where the recording medium of the present invention is not longer than 30 seconds, a method of reducing the Steckigt sizing degree of the recording medium of the present invention to 30 seconds or less includes, for example, adding a surfactant to a coating liquid for forming an ink receiving layer on a base paper Method. As the surfactant used at this time, for example, a conventionally known surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant can be used.

The base paper used in the present invention is specifically obtained by the following method. For example, pulp materials including kenaf pulp listed above, various internal sizing agents for imparting resistance to liquids such as ink and fixing agents for fixing these sizing agents, flexibility of paper,
Various fillers added for the purpose of improving the surface smoothness, opacity, printability, etc., and, if necessary, a paper strength enhancer, a retention enhancer, a defoamer, a conductive agent, a dye, etc. After the internal addition, it is obtained by papermaking with a paper machine selected from a fourdrinier paper machine, a round net paper machine, a short net paper machine, and an inclined wire paper machine. In the present invention, the externally added size processing (surface size) usually performed in this paper machine is not performed for the reason described above.

As the internal sizing agent that can be used in preparing the base paper, a rosin-based sizing agent that has been widely used can be used. In this case, a sulfate band is used as a fixing agent. Added. When a neutral sizing agent such as an alkyl ketene dimer or alkenyl succinic acid is used, it is used together with a cationic fixing aid such as a cationic starch. As the filler, for example, clay, talc, light calcium carbonate, calcined kaolin, aluminum oxide,
An inorganic filler composed of an inorganic pigment such as aluminum hydroxide and titanium oxide may be used. Further, as a paper strength agent,
Polyacrylamide-based polymers, starch and the like can be used.

The kenaf pulp component of the base paper used in the recording medium of the present invention is preferably a mixture of kenaf wood and bast. In the recording medium of the present invention, it is preferable to use a base paper having a thickness of 50 to 250 μm and a basis weight of 50 to 250 m ² / g. The base paper used in the present invention has a disintegration freeness of 3%.
It is preferably from 00 to 600 ml. In preparing the base paper used in the present invention, conventionally known equipment such as a machine calender or a super calender can be used as needed when adjusting the thickness and surface smoothness.

In the recording medium of the present invention, an ink receiving layer is formed on at least one surface of the base paper formed as described above as follows. Hereinafter, the ink receiving layer will be described. The ink receiving layer in the invention contains at least a pigment, and preferably contains a pigment and a binder. Examples of pigments that can be used at this time include, for example, silica, zeolite, calcium carbonate, diatomaceous earth, kaolin clay, calcined clay, talc, aluminum hydroxide, colloidal alumina, alumina, alumina hydrate, barium sulfate, titanium dioxide, Pigments that have been conventionally used as coating agents for general coated paper, such as zinc oxide, zinc carbonate, magnesium silicate, magnesium carbonate, and organic pigments (plastic pigments), may be mentioned. In the present invention, these pigments can be used alone or in combination of two or more. Particularly preferred pigments are alumina hydrate or silica.

In the present invention, when the ink receiving layer of the recording medium is formed, a coating liquid in which these pigments are dispersed is prepared, and this is coated on at least one surface of the base paper. In this case, it is preferable that the average particle diameter of the pigment be less than 500 nm in a state where the pigment is dispersed in the coating liquid.
Alumina hydrate tends to be in such a state, and in the present invention, alumina hydrate may be used as a pigment constituting the ink receiving layer. Further, among the alumina hydrates having such a particle diameter, the BET specific surface area is 5 to 500 m ^2.
/ G of alumina hydrate is more preferred.

In the recording medium of the present invention, if the average particle diameter of the pigment in a dispersed state in the coating liquid is larger than 500 nm, the surface giving an extremely white impression when the ink receiving layer is formed. And the color and texture of the kenaf may be impaired. On the other hand, if the ink receiving layer is formed using a pigment in a dispersed state in the coating liquid having an average particle diameter of less than 500 nm, the color and the texture of the base paper kenaf are impaired by the pigment. Never be.

If alumina hydrate suitable for the present invention, particularly alumina hydrate such as X-ray amorphous or boehmite and pseudo-boehmite, and gamma alumina are used, for example, acetic acid, hydrochloric acid, nitric acid, formic acid, etc. A coating liquid in which alumina hydrate is dispersed in a state where the average particle diameter is 300 nm or less can be obtained relatively easily by a known treating agent. As a result, if the ink receiving layer is formed using the coating liquid, a recording medium can be obtained in which the color and texture of the kenaf paper as the base paper are maintained without loss.

Further, in addition to the above-mentioned advantages, the alumina hydrate has a positive charge, and thus is fixed to a dye having a negative charge, which is used in an ink widely used for ink jet recording and the like. There is an advantage that the property is good. Therefore, if the ink receiving layer is formed by using alumina hydrate, an image having excellent color developability can be formed. Therefore, if alumina hydrate is used as the pigment constituting the ink receiving layer of the recording medium of the present invention, a silica compound conventionally known as a material for the ink receiving layer is used, and a coating layer similar to the conventional one is used. Does not cause problems such as browning of black ink and problems such as light fastness that occur when an ink receiving layer is formed, and especially when a full-color image is formed, compared with a conventional recording medium in terms of image quality. A particularly favorable result is obtained.

The ink receiving layer of the recording medium of the present invention is formed by containing at least the above-mentioned pigments. Preferably, these pigments are stably fixed to at least one surface of the base paper. It is preferable to constitute with the binder for the above. As the binder used at this time, for example, polyvinyl alcohol, modified polyvinyl alcohol, polyacrylamide, partially saponified polyvinyl acetate, oxidized starch, etherified starch, cellulose derivatives such as carboxymethylcellulose and hydroxyethylcellulose, casein, gelatin, Soy protein, maleic acid resin, and the like. These may be used alone or in combination of two or more.

In the present invention, a coating solution containing the binder as described above and the pigment such as alumina hydrate described above is prepared, and the coating solution is applied to at least one surface of the base paper containing kenaf pulp. It is preferable to apply and dry to form an ink receiving layer. It is preferable that the compounding ratio of the pigment in the coating liquid at this time is 15 to 90% by weight of the total solids of the formed ink receiving layer.
In other words, if the amount is less than 15% by weight, when an image is formed on the formed ink receiving layer, the fixability of the dye in the ink tends to be insufficient, and the resulting image may have reduced print density, feathering, and bleeding. Occurrence is observed, and character quality and image quality are easily impaired. On the other hand, when the content exceeds 90% by weight, powder falls off from the formed ink receiving layer, and when the recording medium of the present invention is applied to an ink jet printer or the like, there may be a problem in transportability. In addition, the surface on which the ink receiving layer is formed tends to be white, and the natural color and texture of kenaf are likely to be impaired.

Further, in the present invention, when a binder is used for forming the ink receiving layer, the compounding ratio of the binder is set to be 10 to 85% by weight of the total solid of the ink receiving layer on which the binder is formed. preferable.
In other words, when the content exceeds 85% by weight, the ink absorption of the ink receiving layer tends to be impaired due to the formation of a film by the binder. On the other hand, if the content is less than 10% by weight, the binding strength of the ink receiving layer to at least one surface of the base paper is insufficient, and there is a possibility that powder may fall off. However, when alumina hydrate is used alone as a pigment constituting the ink receiving layer, the alumina hydrate is easily applied to at least one surface of the base paper when it is applied to at least one surface of the base paper. While sinking, the natural feel of the base paper is maintained as it is, but in normal use, there is almost no problem of powder falling off the recording medium surface. There is no problem without using a binder. Therefore, in the present invention, the binder is not always essential when forming the ink receiving layer.

In the coating liquid for forming the ink receiving layer, a pigment dispersant,
Printed matter after recording when an image is formed using an aqueous ink such as an antifoaming agent, a coloring agent, an antioxidant, an ultraviolet absorber, a viscosity modifier, a lubricant, a crosslinking agent, and an ink for inkjet recording. A cationic compound, a cationic resin or the like for improving the water resistance of the recording medium is appropriately selected and used in accordance with the production conditions of the recording medium and the required performance such as the printing quality of the obtained printed matter.

Next, a method for forming the ink receiving layer will be described. First, the components of the ink receiving layer described above are uniformly dispersed or dissolved in an aqueous medium by an ordinary method to prepare a coating liquid. As the aqueous medium used at this time, water or a mixed medium of water and an organic solvent is used. As the dispersion method, for example, using a dispersing machine such as a ball mill, an attritor, a sand mill, a homomixer, a microfluidizer (manufactured by Microfluidics), a nanomizer (manufactured by Nanomizer), and uniformly dispersing or dissolving. Is preferred.

The viscosity of the coating liquid prepared as described above varies depending on the coating method, coating apparatus, coating amount, and the like used when coating the coating liquid on at least one surface of the base paper. However, in general, it is preferable to adjust and use 30 cps to 1000 cps. If it is lower than 30 cps, it is difficult to apply a predetermined amount of the coating liquid on at least one surface of the base paper, and if it is higher than 1000 cps, the coated surface is not uniform, which is not preferable.

In the present invention, an ink receiving layer is provided on at least one surface of the base paper having kenaf pulp by applying a coating liquid having the above-described structure using a coating apparatus or a size press apparatus. As a coating method, either an on-machine coater or an off-machine coater may be used, and a conventionally known air knife coater, die coater, blade coater, gate roll coater, bar coater, rod coater, roll coater, gravure coater, curtain coater, etc. Can be used. Then, after coating on at least one surface of the base paper, the coating liquid is dried by blowing hot air to form an ink receiving layer. The temperature and the flow rate of the hot air at this time may be appropriately changed depending on the base paper and the coating liquid to be used.
Preferably, the temperature is about 0 ° C. If the temperature is lower than 50 ° C., it takes a long time to dry.

Further, after coating, a calendering treatment such as a machine calender, a super calender, a soft calender, etc. may be performed to smooth the surface. In the recording medium of the present invention, the ink receiving layer formed on at least one surface of the base paper as described above has a solid content of 1 to 10 g / m2 when expressed in terms of a solid coating amount (basis weight). The range of ² is preferred. That is, in the case of a recording medium having an ink receiving layer having a coating amount of less than 1 g / m ² , when an image is formed, a print density is reduced, feathering and bleeding are liable to occur, and character quality and image quality are reduced. The image tends to be inferior in quality. On the other hand, when a recording medium having an ink receiving layer having a coating amount of more than 10 g / m ² is used, the whiteness of the ink receiving layer surface increases, and the natural color of kenaf is impaired. Since the surface of the kenaf paper as the base paper itself is covered with the components of the ink receiving layer quite densely, the texture of the kenaf paper is considerably impaired. In the invention, it is particularly preferable to form the ink receiving layer so that the coating amount is 10 g / m ² or less from the viewpoint of maintaining the color and texture of the kenaf paper.

In many cases, the ink receiving layer constituting the recording medium of the present invention formed as described above is not formed so as to cover at least one surface of the base paper having kenaf pulp, It is formed with the coating liquid partially penetrating into the paper. That is, in the recording medium of the present invention, since a part of the coating liquid is impregnated inside the base paper, the boundary between the ink receiving layer and the base paper is not always clear. For this reason, the color and texture of the ink receiving surface on the side where the ink receiving layer is formed can be made not different from the kenaf paper as the base paper.

The recording medium of the present invention can be used for various recording methods. In particular, in the past, it was difficult to say that bleeding or feathering occurred, the print density was low, and the image quality was good. A remarkable effect can be obtained when used in an ink jet recording system using an aqueous ink. In this case, as the ink used in the ink jet recording method, a normal ink including a colorant, a liquid medium, and other additives may be used. As a coloring agent at this time, a direct dye,
Acid dyes, basic dyes, reactive dyes, or water-soluble dyes such as food dyes, etc., as the liquid medium, water, or an aqueous liquid medium using water and various water-soluble organic solvents may be used. it can.

Examples of other recording methods that can use the recording medium of the present invention include, for example, a resin film, a high-density paper, a synthetic paper and a hot-melt ink containing a hot-melt substance, a dye or the like as a main component. A thermal transfer recording method in which a medium coated on a thin base material is heated from the back side, and the ink is melted and transferred. A solid ink jet is used to heat and melt the hot-melt ink to form small droplets and fly and record. Examples include a recording method, an ink-jet recording method using an ink in which an oil-soluble dye is dissolved in a solvent, and a recording method using a photosensitive pressure-sensitive donor sheet using microcapsules containing a photopolymerizable monomer and a colorless or colored dye / pigment. Can be

The common feature of these recording methods is that the ink is in a liquid state during recording. The liquid ink has a property of penetrating or diffusing in the depth direction or the horizontal direction of the ink receiving layer of the recording medium before curing, solidifying or fixing, and the recording medium for these various recording methods is adapted to each method. Requires proper absorption. Therefore, in the recording medium of the present invention, when forming an ink receiving layer, by appropriately selecting a pigment, a binder, and the like, it is possible to form a recording medium having an appropriate absorbency suitable for the various recording methods described above. Good.

Further, the recording medium of the present invention is also used as a recording medium of an electrophotographic recording system widely used in copiers, printers and the like, and a recording system for heating and fixing a toner which is a solid recording agent which is not liquid. it can. Further, it can be used as a recording medium for forming characters and images with ordinary writing implements or paints, or as a recording medium for a recording method using a special ink such as a print.

[0039]

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. In addition, “%” in the text is based on weight unless otherwise specified. Example 1 First, the woody part of kenaf from Thailand was 20% and the bast part was 80%.
% Cooking, bleaching, Canadian Standard
A kenaf paper raw material having a freeness of 410 ml was obtained. To the kenaf paper raw material obtained above, light calcium carbonate (trade name “PC-700”,
5% of internal sizing agent (manufactured by Shiraishi Industry Co., Ltd.) (trade name "Size Pine K-903" manufactured by Arakawa Chemical Co., Ltd.)
1%, a yield improver (trade name “High Holder 35
1 ", manufactured by Kurita Kogyo Co., Ltd.) and then papermaking using a fourdrinier paper machine so that the grammage becomes 180 g / m ^2.
A base paper containing 0% and not subjected to external size treatment was obtained.
The Stockigt sizing degree of this base paper was 125 seconds.

Next, a coating liquid having the following composition (in terms of solid content) was coated on one surface of the base paper with a dry solid content of 10 g /
After coating so that the m ^2, dried to form an ink-receiving layer to obtain a recording medium of the present embodiment. Water was used as the aqueous medium of the coating liquid. In addition, the obtained recording medium had a Steckigt sizing degree of 13 seconds. Pigment: 10 parts by weight fine particle silica (trade name "Syloid", manufactured by Fuji Silysia Chemical Ltd., BET ratio area: 300 m ² / g) Cationic substance: Polyallylamine hydrochloride (trade name "PAA-HCl-3L" Molecular weight 10,000, manufactured by Nitto Bo) 3 parts by weight Surfactant:-Polyethylene polypropylene glycol ether (trade name "Epan 420", manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight Binder:-Polyvinyl alcohol (trade name " PVA117 ", manufactured by Kuraray Co., Ltd.) 1 part by weight

Example 2 The same kenaf paper as used in Example 1 was used as a base paper, and one side of the obtained base paper was coated using only alumina hydrate as a pigment having the following composition (in terms of solid content). The liquid was applied so as to be 8 g / m ^{2 in} terms of dry solid content, and then dried to form ink receiving layers, respectively, to obtain a recording medium of Example 2. The resulting recording medium had a Stekigt sizing degree of 5 seconds. Pigment: 10 parts by weight of alumina (trade name "Alumina Sol 520", manufactured by Nissan Chemical Co., Ltd., BET specific surface area: 232 m ² / g) Cationic substance:-Benzalkonium chloride (trade name "G-50", Sanyo Chemical Industry Co., Ltd.) 3) parts by weight Binder: 1 part by weight of polyvinyl alcohol (trade name "PVA117", manufactured by Kuraray Co., Ltd.)

Example 3 40 parts by weight of so-called whole stem kenaf pulp obtained by digesting and blanching all woody and bast parts of Thai kenaf, 40 parts by weight of softwood bleached kraft pulp (NBKP), and hardwood bleached kraft pulp (LBKP) 20 parts by weight), 1.5 parts by weight of a rosin-based sizing agent (trade name "SPN700", manufactured by Arakawa Hayashi San Kagaku Co., Ltd.), 5 parts by weight of a sulfuric acid band as a fixing agent, and a paper strength agent 0.5 parts by weight of starch (trade name "Amicol", manufactured by Nisse Chemical Co., Ltd.)
Freeness 400ml, Fourdrinier paper machine, basis weight 125g / m
Papermaking to be ^2, as the pulp raw material, to obtain a base paper obtained by mixing the kenaf pulp and wood pulp. The resulting paper had a Steckigt sizing degree of 120 seconds. One side of the base paper obtained above was coated with the same coating liquid as in Example 1 so as to have a dry solid content of 5.5 g / m ^2, and then dried to form an ink receiving layer. Thus, a recording medium of this example was obtained. The resulting recording medium had a Stöckicht sizing degree of 20 seconds.

Images were formed on the recording media of Examples 1 to 3 using an ink jet printer (trade name "BJC430", manufactured by Canon Inc.), and the recording media after printing were evaluated as follows. . That is, the recording medium after printing was visually observed, and was evaluated as ○ when the texture of the Japanese paper remained, and as X when the texture was impaired. Immediately after printing, the printed area was touched with the hand. The ink was evaluated as ○ if the ink did not adhere to the hand, and evaluated as × if the ink did adhere to the hand. Furthermore, the recording medium after printing was visually observed, and was evaluated as ○ if no bleeding, strikethrough, or deformation was observed, and evaluated as × if observed. Observe the printed image visually, and if the image is clear,
If it was unclear, it was evaluated as x. Table 1 shows the results of each evaluation. In addition, regarding the degree of Stekigt size of each recording medium measured based on JIS-P-8122,
The results are summarized in Table 1.

[0044]

[Table 1] Table 1 Evaluation results

[0045]

According to the present invention as described above, the following effects can be obtained. 1. The recording medium of the present invention has a unique Japanese paper texture. 2. By providing the ink receiving layer on at least one surface of the base paper, the ink is quickly penetrated into the base paper,
In addition, since the spread of the ink dots on the paper surface can be suppressed, image clarity and beading are improved, and a high-quality image can be formed.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C09D 201/00 D21H 1/22 Z 5/14 Z 5/00 Z

Claims (9)

[Claims] 1. A recording medium in which a pigment-containing ink receiving layer is provided on at least one surface of a base paper containing kenaf pulp, wherein the base paper has been internally sized but has been subjected to external sizing. And a recording medium having a Stöckigt sizing degree of 30 seconds or less. 2. The recording medium according to claim 1, wherein the base paper has a Steckigt sizing degree of 200 seconds or less. 3. The base paper contains 10% by weight of kenaf pulp.
The recording medium according to claim 1, wherein the recording medium is contained at 00% by weight. 4. The recording medium according to claim 1, wherein a surfactant is contained in the ink receiving layer. 5. A pigment having a BET specific surface area of 5 to 500 m ² /
The recording medium according to claim 1, wherein the recording medium is g of alumina hydrate or silica. 6. The recording medium according to claim 1, wherein a cationic substance is contained in the ink receiving layer. 7. When the ink receiving layer is represented by a coating amount,
Recording medium according to claim 1 coated amount is 1 to 10 g / m ² in solids. 8. The recording medium according to claim 1, wherein the basis weight is 50 to 250 g / m ² . 9. An ink jet recording method, wherein recording is performed using the recording medium according to claim 1.