KR20040108216A - A photopaper for inkjet recording - Google Patents

Abstract

PURPOSE: A photo paper for inkjet printing is provided to have excellent ink absorbency, image sharpness, light fastness, water resistance and scratch resistance. CONSTITUTION: The photo paper for inkjet printing comprises: a first ink storage layer(4) having water soluble or hydrophilic resin and pigment formed on the top of a base layer(2); and a second ink storage layer(5) having resin, inorganic particles and a slip agent formed on the top of the first ink storage layer. The photo paper for inkjet printing has excellent ink absorbency and sharp color images and shows excellent water resistance, light fastness and scratch resistance.

Description

Photo paper for inkjet recording

The present invention relates to a photo paper for inkjet recording. More specifically, the present invention relates to a photo paper for ink jet recording, which has a vivid color image and excellent water resistance and is excellent in light resistance and scratch resistance.

The inkjet printing method is a printing method in which ink is sprayed through a thin nozzle to print. The inkjet printing method has a high printing speed, low maintenance costs associated with printing output, and recently, a high resolution image can be provided. It is used a lot. The recording medium used for printing in such an inkjet method includes a variety of recording media such as general paper, specially coated exclusive paper, dedicated film, and the like.

An ink-receiving layer, which is a recording medium that effectively reflects the characteristics of the inkjet printing method as described above, on a support surface made of paper or the like made of pulp, which sufficiently absorbs an aqueous ink and makes an image clear. This coating is mainly provided. Generally, a dispersion in which a pigment such as a silica compound or an alumina compound is dispersed in a binder resin such as polyvinyl alcohol or the like is applied onto a surface of the support to form an ink receiving layer, thereby forming a structure in which the support and the ink receiving layer are stacked in order. There is provided a recording medium having. For example, Japanese Patent Application Laid-Open No. 57-82085 discloses a recording medium containing an inorganic pigment and an organic pigment and having an ink receiving layer made of a water-soluble resin, and Japanese Patent Laid-Open No. 62-268682 discloses fine silica powder. Disclosed is a recording medium having an ink receiving layer comprising a polyvinyl alcohol copolymer having a silanol group.

As described above, one of the recording media coated with a specific component such that a paper or the like is provided with a specific component on the upper surface of the support so as to provide suitable properties for an inkjet printing method is a photo paper for an inkjet printer. This photo paper for inkjet printers is produced by coating a top surface of a substrate such as single-sided or double-sided art paper, cast coated paper, polyethylene terephthalate, synthetic paper, polypropylene film, photo paper, etc. with a material having excellent ink absorption, ink fixing, water resistance, and light resistance, Background Art [0002] It is used for digital photography or image printing using inkjet printers such as thermal, piezoelectric or phase-transfer methods, or in exterior wall decoration, design, and advertising.

Such photo papers for inkjet recording have been developed in various ways. For example, US Pat. No. 5,866,268, Japanese Patent Laid-Open No. 55-144172, Japanese Patent Laid-Open No. 62-268682 include a hydrophilic resin such as a cellulose derivative and a polyvinyl alcohol copolymer. Disclosed is a photo paper for ink jet recording used in the art. However, these papers have poor light resistance and have poor water resistance, such as an image flowing when immersed in water within 10 minutes after printing. In addition, Japanese Laid-Open Patent Publication No. 60-232990 and Japanese Laid-Open Patent Publication No. 6-199035 disclose inkjet recording photo papers using alumina hydrate together with a water-soluble binder, but these papers have excellent water absorption and gloss, It has a disadvantage of poor scratchability.

Therefore, there is a need to develop a photo paper for ink jet recording, which has fast ink absorption and excellent color development, and also has durability such as light resistance, water resistance and scratch resistance.

The technical problem to be solved by the present invention is to provide an inkjet recording photo paper having excellent ink absorption, image clarity, light resistance, water resistance and scratch resistance in order to solve the problems of the prior art as described above.

1 is a diagram showing a cross-sectional structure of an inkjet recording photo paper according to an embodiment of the present invention.

<Brief description of the major symbols in the drawings>

1 .: back coating (optional component)

2 .: substrate layer

3 .: Undercoat (optional component)

4 .: First ink receiving layer

5 .: second ink receiving layer

In order to solve the above technical problem, the present invention has a first ink receiving layer containing a water-soluble or hydrophilic resin and a pigment on the base layer, and a second containing a resin, inorganic particles and slip agent on the first ink receiving layer An ink jet recording photo paper having an ink receiving layer is provided.

The resin of the first ink receiving layer and the second ink receiving layer constituting the inkjet recording photo paper may be polyvinyl alcohol resin, polyvinyl pyrrolidone resin, cellulose, gelatin, polyethylene oxide, acrylic resin, polyester resin, poly It is preferably at least one selected from the group consisting of urethane-based resins and copolymers in the form of quaternary ammonium.

The pigment of the first ink receiving layer is preferably silica particles or alumina particles having an average particle diameter of 20-200 nm that can improve ink absorption and color development.

The first ink receiving layer further comprises at least one curing agent selected from the group consisting of glyoxal, zirconium oxychloride, oxazoline, isocyanate, epoxide, aziridine, melamine-formaldehyde and dialdehyde which crosslink the molecules of the resin. can do.

The inorganic particles of the second ink receiving layer included in the inkjet recording photo paper of the present invention may be at least one selected from the group consisting of calcium carbonate, talc, alumina, silica, and titanium oxide, among which sol has excellent light resistance and ink absorption ability. Preference is given to titanium oxide in the form.

The slip agent of the second ink receiving layer may be at least one selected from the group consisting of a wax, an acrylic compound, and a siloxane compound, and preferably, a siloxane compound.

The substrate layer of the photo paper for inkjet recording of the present invention may be single-sided or double-sided art paper, cast coated paper, photo paper, synthetic paper, polypropene film, polyester film, polycarbonate film, cellulose acetate film or polyethylene terephthalate film.

The inkjet recording photo paper of the present invention is located between the base layer and the ink receiving layer and crosslinks at least one resin selected from the group consisting of acrylic resins, polyurethane resins, vinyl resins and polyol resins and molecules of the resins. It may further comprise an undercoat comprising a curing agent residue.

The photo paper for inkjet recording of the present invention may further include a backside coating layer coated on the base layer.

The photo paper for ink jet recording according to the present invention as described above has excellent ink absorption power and clear image, and also improves water resistance, light resistance and scratch resistance, and thus can be usefully used as an effective ink jet recording medium.

The present invention is described in more detail as follows.

According to the present invention, an inkjet recording having a first ink receiving layer containing a water-soluble or hydrophilic resin and a pigment on top of a substrate layer, and a second ink receiving layer containing a resin, inorganic particles and a slip agent on the first ink receiving layer. Photo paper is provided.

Since the first ink receiving layer of the photo paper for inkjet recording plays a role of substantially fixing the ink ejected through the nozzle onto the paper, the ink receiving layer should mainly contain components having excellent ink absorption and image stability. On the other hand, the second ink receiving layer serves to deliver the ink ejected from the printer to the first ink receiving layer and the image formed by fixing the ink delivered to the first ink receiving layer from an external environment or physical contact such as water, heat or light. At the same time protects. Therefore, the second ink receptive layer should include components that can improve not only ink absorbing power but also water resistance and scratch resistance at the same time.

The resin of the first ink receiving layer of the present invention is used as a binder, and polyvinyl alcohol-based resin, polyvinyl pyrrolidone-based resin, cellulose, gelatin, polyethylene oxide, acrylic resin, polyester-based resin, polyurethane resin or quaternary ammonium group It is preferred that at least one selected from the group consisting of a polymer comprising a. The resin used in the first ink receptive layer may serve as a binder of other components of the first ink receptive layer and may be of any kind as long as it does not adversely affect the ink absorption and image clarity of the coated first ink receptive layer. Can be used. In addition, an appropriate molecular weight of such a polymer resin may be appropriately selected in consideration of compatibility with other components included in the first ink receiving layer together with the resin. Among these, cellulose includes, for example, methyl cellulose, hydroxypropyl cellulose, and the like, and polymers including quaternary ammonium groups include, for example, vinylpyrrolidone, N, N-dimethylaminoethylmethacrylic acid copolymer lactate And the like. In particular, the cationic substituent of the polymer containing the quaternary ammonium group can improve the output effect of the anionic ink.

The pigment contained in the first ink receiving layer according to the present invention is preferably silica particles or alumina particles, which is a kind of inorganic filler capable of improving ink absorbency and color development of the first ink receiving layer. It is preferable that such pigment particles have an average particle diameter of 20-200 nm, because when the average particle diameter of the particles is 20 nm or less, the ink absorbency may be poor, and when it is 200 nm or more, the glossiness may be lowered. Even if silica particles or alumina particles having an average particle diameter of 20-200 nm are spherical in form of ink, the silica particles or alumina particles are preferably microporous.

The pigment should be contained in a larger amount than the water-soluble or hydrophilic resin included in the first ink receiving layer as a binder so that the water resistance of the inkjet photo paper is improved. Therefore, the weight ratio of the suitable resin to the pigment of the first ink receiving layer of the present invention is preferably 50: 50-1: 99, more preferably 30: 70-5: 95. However, when the amount of the pigment included in the first ink receiving layer is increased to improve the water resistance of the inkjet photo paper, the glossiness of the ink receiving layer and the adhesive force to the base layer may be lowered. Additives can be used.

The additive that may be included in the first ink receiving layer is one selected from the group consisting of an adhesive, a brightener, a talc, a titanium oxide, a light diffusing agent, a pH adjusting agent, an antioxidant, an antifoaming agent, a leveling agent, a lubricant, an anti-curling agent, a surfactant, and the like. It is preferable that it is above. These additives are used for the purpose of supplementing the physical properties of the photographic paper and improving its functionality, and any additive may be used as long as it satisfies this purpose and does not adversely affect desirable properties of the photographic paper for inkjet recording. Especially when the fluorescent dye is included as an additive, the visible whiteness (apparent whiteness) of the coated paper tends to increase, so that the fluorescent dye is present in an amount of 0.01 to 0.5% by weight based on the total content of the resin and the pigment. It is desirable to prevent the fatigue of the paper user's eyes due to the increase in the apparent whiteness.

In order to improve the water resistance of the photo paper for inkjet recording, a coupling agent or a curing agent may be further included in manufacturing the first ink receiving layer. Examples of suitable curing agents include glyoxal, zirconium oxychloride, oxazoline, isocyanates, epoxides, aziridine, melamine-formaldehyde or dialdehyde and the like. Such hardeners form intermolecular crosslinks of the resin contained in the first ink receptive layer, so that they may be present in the form of the hardener moiety in the first ink receptive layer that is actually coated and dried.

The second ink receptive layer of the photo paper for inkjet recording of the present invention contains a resin used as a binder to increase the adhesive force during coating or to prevent the surface deterioration such as cracks, and is used in the first ink receptive layer as described above. Polyvinyl alcohol-based resin, polyvinyl pyrrolidone-based resin, cellulose, polyester-based resin and the like can all be used. However, when the first ink receiving layer is first formed on the base layer and then the second ink receiving layer is coated on the formed first ink receiving layer, the components of the first ink receiving layer in which the solvent used for the second ink receiving layer is already formed are formed. For example, it is necessary to prevent surface degradation from occurring by dissolving a hydrophilic or water-soluble resin or the like used as a binder. Therefore, the solvent used in the second ink receiving layer is an organic solvent, not a hydrophilic or water-soluble solvent, and the resin of the second ink receiving layer is preferably a hydroxymethyl cellulose or a polyester resin having good solubility in such an organic solvent. Do. The content of the resin contained in the second ink receiving layer is preferably 10-60% by weight of the total solids contained in the second ink receiving layer, and more preferably 20-50% by weight. If the content of the resin is less than 10% by weight, it may not function sufficiently as a binder. If the content of the resin is 60% by weight or more, the ink absorbing power for delivering the ink to the first ink receiving layer may be reduced. 2 It may be difficult to pass through the ink receiving layer.

The inorganic particles included in the second ink receiving layer according to the present invention are preferably calcium carbonate, talc, alumina, silica, titanium oxide, or the like, which may also be included in the first ink receiving layer, and particularly, sol-type titanium oxide having excellent light resistance and ink absorption. Is most preferred. It is preferable that the size of such an inorganic particle is 5-50 nm, because when the particle size is 5 nm or less, ink absorption power falls, and when it is 50 nm or more, glossiness and light resistance fall. The content of the inorganic particles is preferably 30-90% by weight of the total solids contained in the second ink receiving layer, more preferably 50-80% by weight, which is glossiness when the content of the inorganic particles is 90% by weight or more. This is because a lowering of less than 30 wt% may cause a problem of lowering ink absorption.

The second ink receiving layer according to the present invention includes a slip agent which serves to smooth the surface of the photographic paper to protect the image or the paper itself upon physical contact. Examples of such slip agents include waxes, polyethylene powders, acrylic compounds or siloxane compounds, and of these, siloxane compounds are preferred. The content of such slip agent is preferably 1% by weight or less, more preferably 0.5% by weight or less of the total solids contained in the second ink receiving layer. When the slip agent having the above content is included in the second ink receiving layer, the ink absorbing power of the second ink receiving layer is lowered, so that ink cannot be sufficiently delivered to the first ink receiving layer or a feeding error occurs during printing.

The base layer of the photo paper for inkjet recording according to the present invention is generally single-sided or double-sided art paper, cast coated paper, photo paper, and the like, and when the coating composition for forming an ink-receiving layer is coated and then dried to form an ink-receiving layer as described above. It is preferable to have a thickness of 50-300 mu m in order to prevent the paper constituting the base material layer from bending and to facilitate handling. In addition, a synthetic paper, a polyester film, a polypropene film, a polycarbonate film, a polyethylene terephthalate film, a cellulose acetate film, or the like may be used as the base layer depending on the use of the photo paper for inkjet recording.

The inkjet recording photo paper according to the present invention may include an undercoating layer between the ink receiving layer and the base layer in order to enhance the adhesive force between the base layer and the ink receiving layer. The undercoating layer may include a resin having high glossiness, and may provide a photo paper having excellent gloss regardless of the material of the base layer, and may further include a sunscreen, an antioxidant, and the like, to provide a base layer that is vulnerable to light. By supplementing the shortcomings, the light resistance of the photo paper can be improved. In addition, instead of adding a brightening agent or a dye which increases the whiteness of the photo paper but causes yellowing of the printing portion and the non-factor portion to the ink receiving layer, it can be added to the undercoat layer to improve the whiteness of the photo paper without side effects such as a yellowing effect. have.

Examples of the resin that can be used in such an undercoat layer include acrylic resins, polyurethane resins, vinyl resins, polyol resins, and the like, and these are usually used with a curing agent such as a polyisocyanate compound or the like. In addition, as long as it is compatible with water-soluble or hydrophilic resins and pigments contained in the ink receiving layer, papers such as art paper, cast coated paper, photo paper, or polyolefin-based films such as polypropylene and polyethylene, polyethylene terephthalate film, etc. It can be used as resin. The thickness of the undercoat layer is preferably about 0.1-5 탆, more preferably 0.5-2 탆. When the thickness of the undercoat layer is 5 μm or more, the ink absorbency decreases, and when the thickness of the undercoat layer is 0.1 μm or less, the adhesion effect to the ink receiving layer substrate may be reduced.

The photo paper for inkjet recording of the present invention may further include a back coating layer coated on the bottom of the base layer to protect the base layer. The back coating layer is made of one or more materials selected from the group consisting of polyvinyl alcohol-based resin, polyvinylpyrrolidone-based resin, cellulose and acrylic resin, etc. used as a binder in the ink receiving layer to improve continuous feeding and curling phenomenon. It is preferable.

Photo paper for inkjet recording according to the present invention,

a) forming a first ink receiving layer by coating an upper portion of the base layer with a composition for forming a first ink receiving layer comprising a water-soluble or hydrophilic resin and a pigment; And

b) coating the second ink receptive layer by coating the upper portion of the first ink receptive layer formed in step a) with a composition for forming a second ink receptive layer comprising a resin, an inorganic material, and a slip agent;

It is prepared by a method comprising a.

The solvent used in the composition for forming the first ink receiving layer is preferably used in consideration of environmental problems and operational problems, and the content thereof is preferably 200-500% by weight of the total weight of solids to be included in the first ink receiving layer. 300-400% by weight is more preferred. Although water is mainly used as a solvent, in consideration of dissolving and drying the polymer included in the composition for forming the first ink-receiving layer, one or more solvents selected from the group consisting of alcohols, glycol ethers, ketones, and dimethylformamide may be used together. In particular, it is preferable to use an alcohol such as methanol, ethanol, isopropanol, methyl cellosolve, etc. at 50 wt% or less of the total solvent.

When coating the composition for forming the first ink receiving layer, there is no change in ink absorption and fixability at a predetermined thickness or more, and it is generally preferable to coat a thickness of about 10-40 μm. As a coating method, all coating methods, such as an air knife, a knife roll, a reverse, and a slot die method, can be used.

When coating the composition for forming the second ink receptive layer, if the second ink receptive layer formed as a result of coating is too thick, the ink absorption may decrease and curling may occur. If the thickness is too thin, it is difficult to improve the light resistance and scratch resistance of the present invention. Therefore, a coating thickness of 0.5-10 mu m is preferable, and among these, 1-5 mu m is more preferable. The coating technique of the second ink receptive layer formation composition is the same as the coating technique of the composition for forming the first ink receptive layer as described above, and if a small amount is to be coated, a Mayer bar or gravure method may be used.

The undercoating layer, which may be located between the ink receiving layer and the base layer of the inkjet recording photo paper according to the present invention, may be formed by coating the base layer before the first ink receiving layer is formed. It is preferable to coat the composition for forming the undercoat layer in an amount such that the thickness of the undercoat layer is about 0.1-5 μm, and the coating method may be applied to all coating methods, but gravure coating is generally used.

The inkjet recording photo paper of the present invention may further include a backside coating layer coated on the lower portion of the base layer in order to improve continuous feeding and to compensate for curling. The back coating layer is one selected from the group consisting of polyvinyl alcohol resin, polyvinyl pyrrolidone resin, cellulose, gelatin, polyethylene oxide, acrylic resin, polyester resin, and polyurethane resin, which are binder resins used in the ink absorbing layer. The resin may include at least one crosslinker moiety selected from the group consisting of oxazoline, isocyanate, epoxide, aziridine, melamine-formaldehyde, dialdehyde, and a boron compound that crosslinks the molecules of the above resins. It is preferable that the thickness of the backside coating layer is 0.5-4 μm, and this backside coating layer may be formed under the base layer using a conventional coating method.

Hereinafter, the present invention will be described in more detail with reference to Examples, but is not limited thereto.

(Example)

Example 1

A water soluble undercoat layer-forming composition was prepared such that the undercoat layer had a composition as follows.

95 parts by weight of polyol (DL-505SA-1, manufactured by Shinsung Chemical Co., Ltd., Korea)

5 parts by weight of polyisocyanate (manufactured by Shinsung Chemical Co., Ltd., Korea)

The composition for forming the undercoat layer was coated on a gelatinized photo paper having a thickness of 200 μm using a bar coater, and then dried in an oven at 100 ° C. for 1 minute to form an under coating layer having a thickness of 1 μm on the photo paper. .

The composition for forming a water-soluble first ink receiving layer was prepared such that the first ink receiving layer had a composition as follows.

10 parts by weight of polyvinyl alcohol (CM-318, product made by Nippon Kuraray Co., Ltd.)

87 parts by weight of alumina sol (HN-AL30, manufactured by Hana Chemical Co., Ltd., Korea)

0.5 parts by weight of fixer (HANWET HF-59, manufactured by Hansol Chemence, Korea)

2.5 parts by weight of zirconium oxychloride (manufactured by Japan Pure Chemical Industries, Ltd.)

The first ink receiving layer-forming composition was coated using a bar coater on the undercoating layer formed as described above. This was dried in an oven at 110 ° C. for 3 minutes to form a first ink receiving layer having a thickness of 30 μm on the undercoat.

A water-soluble second ink-receiving layer-forming composition was prepared such that the second ink-receiving layer had a composition as follows.

Titanium oxide sol (CST-10, manufactured by MCI, Korea) 70 parts by weight

0.5 parts by weight of polyethersiloxane (Glide 450, manufactured by Tego, Germany)

29.5 parts by weight of hydroxypropyl cellulose (Klucel-E, manufactured by Hercules, France)

The composition for forming the second receiving layer was coated on the first ink receiving layer formed as described above using a bar coater. It was dried in an oven at 110 ° C. for 1 minute to form a second ink receiving layer having a thickness of 1 μm on the first ink receiving layer, thereby stacking photo paper, an undercoating layer, a first ink receiving layer, and a second ink receiving layer. Photo paper for inkjet recording having a was prepared.

Example 2

An inkjet recording photo paper was produced in the same manner as in Example 1 except that the first ink-receiving layer-forming composition was prepared such that the first ink-receiving layer had a composition as follows.

10 parts by weight of polyvinyl alcohol (CM-318, product made by Nippon Kuraray Co., Ltd.)

86.5 parts by weight of alumina sol (HN-AL30, manufactured by Hana Chemical Co., Ltd., Korea)

0.5 parts by weight of fixer (HANWET HF-59, manufactured by Hansol Chemence, Korea)

2.5 parts by weight of zirconium oxychloride (manufactured by Japan Pure Chemical Industries, Ltd.)

0.5 parts by weight of a fluorescent brightener (Tinopal IJT, manufactured by Shiva Chemical, France)

Example 3

An inkjet recording photo paper was produced in the same manner as in Example 1 except that the first ink-receiving layer-forming composition was prepared such that the first ink-receiving layer had a composition as follows.

10 parts by weight of polyvinyl alcohol (CM-318, product made by Nippon Kuraray Co., Ltd.)

86.5 parts by weight of silica sol (ST-PS-M, manufactured by Nissan Chemical, Japan)

0.5 parts by weight of fixer (HANWET HF-59, manufactured by Hansol Chemence, Korea)

2.5 parts by weight of zirconium oxychloride (manufactured by Japan Pure Chemical Industries, Ltd.)

0.5 parts by weight of a fluorescent brightener (Tinopal IJT, manufactured by Shiva Chemical, France)

Example 4

An inkjet recording photo paper was produced in the same manner as in Example 2 except that the second ink receiving layer-forming composition was prepared such that the second ink receiving layer had a composition as follows.

10 parts by weight of titanium oxide (TINT-AYD WD2002, manufactured by Ilimentis, Germany)

0.5 parts by weight of polyethersiloxane (Glide 410, manufactured by Tego, Germany)

89.5 parts by weight of polyester (EW-300, manufactured by SK Chemicals, Inc.)

Example 5

The photo paper for inkjet recording was produced in the same manner as in Example 2 except that the undercoating layer was not formed.

Comparative Example 1

The photo paper for inkjet recording was produced in the same manner as in Example 1 except that the second ink receiving layer was not formed.

Comparative Example 2

The photo paper for inkjet recording was produced in the same manner as in Example 2 except that the second ink receiving layer was not formed.

Comparative Example 3

The photo paper for inkjet recording was produced in the same manner as in Example 3 except that the second ink receiving layer was not formed.

Comparative Example 4

The photo paper for inkjet recording was produced in the same manner as in Example 4 except that the second ink receiving layer was not formed.

Comparative Example 5

The photo paper for inkjet recording was produced in the same manner as in Example 5 except that the second ink receiving layer was not formed.

Comparative Example 6

An inkjet recording photo paper was produced in the same manner as in Example 2 except that the second ink receiving layer-forming composition was prepared such that the second ink receiving layer had a composition as follows.

Titanium oxide sol (CST-10, manufactured by MCI, Korea) 70 parts by weight

5 parts by weight of polyethersiloxane (Glide 450, manufactured by Tego, Germany)

25 parts by weight of hydroxypropyl cellulose (Klucel-E, manufactured by Hercules, France)

Comparative Example 7

The photo paper for inkjet recording was produced in the same manner as in Example 2 except that the second ink receiving layer was formed so that the thickness of the second ink receiving layer was 10 m.

Experimental Example 1 Measurement of Ink Absorption, Image Clarity, and Water Resistance

1) Measurement of Ink Absorption

Immediately after printing a black image on each photo paper using an Epson Stylus Photo 1290 printer and an HP Photosmart 100 printer, the white paper was stacked, a 5 kg iron ball was placed for 10 seconds, and the amount of ink on the white paper was checked.

2) Measurement of Image Sharpness

After printing magenta and black images using an Epson Stylus Photo 1290 printer and an HP Photosmart 100 printer, the light density of images printed on each photo paper was measured with a D196 light density meter (manufactured by GretagMacbeth, USA).

3) Measurement of water resistance

Images of yellow, magenta, cyan, and black are printed on each sheet using Epson Stylus Photo 1290 printer and HP Photosmart 100 printer, and the D196 light density meter (GretagMacbeth, USA) The density was measured. After 24 hours of printing, each sheet on which an image was printed was immersed in tap water for 3 hours. After 3 hours, the paper was taken out of tap water and dried in an oven at 30 ° C. for 24 hours, and then the light density of the image was measured again using a D196 light density meter (Gretag Macbeth, USA), and the previously measured light density (printed photo paper was measured). Light density measured before immersion in tap water).

The ink absorbing power, sharpness and water resistance of the photo paper according to Example 1-5 and Comparative Example 1-7 were evaluated by the above methods, and the results are summarized in Table 1 below.

Ink absorbance Optical Density Water resistance Epson Stylus Photo 1290 HP Photosmart 100 magenta black magenta black Example 1 1.12 2.61 1.51 1.91 Example 2 1.13 2.59 1.53 1.92 Example 3 1.14 2.57 1.52 1.91 Example 4 1.12 2.60 1.54 1.90 Example 5 1.13 2.59 1.52 1.92 Comparative Example 1 1.13 2.59 1.53 1.93 Comparative Example 2 1.11 2.63 1.51 1.91 Comparative Example 3 1.15 2.62 1.54 1.89 Comparative Example 4 1.12 2.61 1.52 1.90 Comparative Example 5 1.11 2.59 1.53 1.91 Comparative Example 6 △ 1.19 2.79 1.59 2.05 Comparative Example 7 × 1.25 2.81 1.67 2.21 ×

In the case of the ink absorbency shown in Table 1, the ink does not come out on the white paper, which shows the excellent ink absorption. The case where the white paper paper is stained with ink and exhibits poor ink absorption is indicated by x, and the middle case by Δ. As a result of the experiment, the ink absorbency of the photo paper of Comparative Example 6-7 was relatively poor compared to the ink absorbency of the remaining photo papers. As a result, when the content of the siloxane serving as the slip agent among the components included in the second ink receiving layer is too high, or when the second ink receiving layer is too thick, the ink ejected from the printer is placed in the lower portion of the second ink receiving layer. It becomes difficult to move to a receiving layer, and it can confirm that the ink absorbency of the photo paper for inkjet recording falls. However, the ink of all the photo paper of Comparative Example 6-7 adhered to the surface of the photo paper, so that the light density was relatively high.

On the other hand, the higher the light density value described in Table 1, the better the image clarity. In particular, in the case of Example 1-5, it showed excellent results compared to the existing released products.

In the case of water resistance evaluation, the case where there is a change in light density measured before immersing the printed paper in tap water and the light density measured after immersion is × It is shown as. Accordingly, it can be seen that the photo paper having relatively weak water resistance is the photo paper of Comparative Example 7, whereby the second ink receiving layer having a predetermined thickness or more does not help to improve the water resistance.

Experimental Example 2 Measurement of Light Resistance

Using an Epson Stylus Photo 1290 printer and an HP Photosmart 100 printer, images of yellow, magenta and cyan were printed on the photo papers of Examples 1-5 and Comparative Examples 1-7, and the light density of the images was measured using a D196 optical density meter. (Measured by Gretag Macbeth, USA). The image was exposed to light resistance evaluator (Q-Sun / 3000 Xenon Tester, manufactured by Q-Lab, USA) for 10 hours at 60 ° C., and then optical density was measured with the optical density meter. By comparing the two optical density values, the reduction ratio was calculated and the results are summarized in Table 2 below.

Epson Stylus Photo 1290 HP Photosmart 100 yellow magenta draft yellow magenta draft Example 1 8% 3% 5% 3% 6% 8% Example 2 9% 5% 6% 5% 8% 9% Example 3 8% 5% 7% 5% 7% 9% Example 4 9% 4% 6% 4% 8% 8% Example 5 8% 4% 6% 6% 8% 8% Comparative Example 1 13% 8% 10% 10% 14% 12% Comparative Example 2 16% 11% 14% 14% 16% 14% Comparative Example 3 18% 12% 15% 13% 17% 15% Comparative Example 4 14% 13% 13% 14% 16% 13% Comparative Example 5 15% 9% 12% 12% 13% 14% Comparative Example 6 12% 8% 9% 9% 11% 10% Comparative Example 7 9% 5% 7% 4% 7% 8%

The smaller the light density change rate described in Table 2 above, the better the light resistance of the photo paper. When comparing the light density change rate of Example 1-5 and Comparative Example 1-5, when the 2nd ink receiving layer which concerns on this invention was introduce | transduced into the inkjet recording photo paper, it can be seen that light resistance improves. However, when the content of the siloxane that acts as a slip agent among the components included in the second ink receiving layer is high (Example 6), it is found that the light resistance is lowered, and when the second ink receiving layer is too thick (Example 7 ), The light resistance did not increase much. This is considered to be because the ink ejected from the printer did not pass through the second ink receiving layer and adhered to the photo paper surface.

Experimental Example 3 Measurement of Durability and Scratch Resistance

1) hardness measurement

The hardness of each sheet was measured with a hardness tester TH 130 (manufactured by Time, USA).

2) Scratch resistance measurement

A black image was printed on each sheet with an Epson Stylus Photo 1290 printer (manufactured by Epson Japan), and then the light density of each image was measured with a D196 light density meter (manufactured by GretagMacbeth, USA). The image was tested with a 5130 Abraser (manufactured by Taber, USA), and the rotation speed was recorded when the light density of this image became 50% of the original image light density.

In this manner, the durability and scratch resistance of the photo paper of Examples 1-5 and Comparative Example 1-7 were evaluated, and the results are summarized in Table 3 below.

Hardness Scratch resistance Example 1 400 120 Example 2 390 120 Example 3 400 130 Example 4 410 130 Example 5 380 100 Comparative Example 1 350 80 Comparative Example 2 350 70 Comparative Example 3 340 70 Comparative Example 4 340 80 Comparative Example 5 320 60 Comparative Example 6 420 150 Comparative Example 7 470 180

The hardness described in Table 3 indicates the surface strength of the photo paper, that is, the durability. The higher the value, the higher the strength of the photo paper. From Table 3, it can be seen that when the second ink receiving layer according to the present invention is introduced into the inkjet recording photo paper, the surface strength of the photo paper increases. This is considered to be because when the second ink receiving layer according to the present invention containing the siloxane-based slip agent is introduced into the photo paper, the surface friction of the photo paper is reduced to increase the surface hardness of the photo paper.

On the other hand, scratch resistance is a property of scratch resistance on the surface of the photo paper, and the higher the rotation speed, the higher the scratch resistance. As can be seen from the numerical values of Comparative Example 6-7, it was found that excellent scratch resistance can be obtained by introducing a coating layer having excellent hardness.

As described above, the photo paper for inkjet recording incorporating the first ink receiving layer and the second ink receiving layer according to the present invention exhibits excellent ink absorption and water resistance, and also improves light resistance and scratch resistance, making the recording highly suitable for inkjet printing. It can be used as a medium.

Claims (16)

A first ink receiving layer containing a water-soluble or hydrophilic resin and a pigment on the base layer, and a second ink receiving layer containing a resin, inorganic particles, and a slip agent on the first ink receiving layer. Photo paper. The resin of the first ink receiving layer and the second ink receiving layer is polyvinyl alcohol resin, polyvinyl pyrrolidone resin, cellulose, gelatin, polyethylene oxide, acrylic resin, polyester resin, polyurethane resin. And at least one selected from the group consisting of polymers containing quaternary ammonium groups. The photo paper for inkjet recording according to claim 1, wherein the pigment of the first ink receiving layer is silica particles or alumina particles having an average particle diameter of 20-200 nm. The photo paper for inkjet recording according to claim 1, wherein the weight ratio of the resin to the pigment contained in the first ink receiving layer is 50: 50-1: 99. The method of claim 1, wherein the first ink receiving layer further comprises at least one additive selected from the group consisting of fluorescent dyes, talc, light diffusing agents, pH adjusting agents, antioxidants, antifoaming agents, leveling agents, lubricants, anti curling agents and surfactants. An inkjet recording photo paper comprising a. The method of claim 1, wherein the first ink receiving layer is selected from the group consisting of glyoxal, zirconium oxychloride, oxazoline, isocyanate, epoxide, aziridine, melamine-formaldehyde and dialdehyde which crosslink the molecules of the resin. An ink jet recording photo paper further comprising at least one curing agent residue. The photo paper for inkjet recording according to claim 1, wherein the inorganic particles of the second ink receiving layer are at least one selected from the group consisting of calcium carbonate, alumina, silica and titanium oxide. The photo paper for inkjet recording according to claim 1, wherein the inorganic particle size of the second ink receiving layer is 5-50 nm. The photographic paper for inkjet recording according to claim 1, wherein the inorganic particle content of the second ink receptive layer is 30 to 90% by weight of the solids contained in the second ink receptive layer. The photo paper for inkjet recording according to claim 1, wherein the slip agent of the second ink receiving layer is at least one selected from the group consisting of wax, acrylic compound and siloxane compound. The photo paper for inkjet recording according to claim 1, wherein the slip agent content of the second ink receiving layer is 1% by weight or less of the solids contained in the second ink receiving layer. The photographic paper according to claim 1, wherein the base layer is single-sided art paper, double-sided art paper, cast coated paper, photo paper, synthetic paper, polyester film, polycarbonate film, cellulose acetate film, or polyethylene terephthalate film. The method of claim 1, wherein one or more resins selected from the group consisting of acrylic resins, polyurethane resins, vinyl resins, and polyol resins and the curing agent residues are located between the base layer and the ink receiving layer. An inkjet recording photographic paper, further comprising an undercoat layer. The photo paper for inkjet recording according to claim 13, wherein the curing agent is a polyisocyanate compound. The photo paper for inkjet recording according to claim 13, wherein the undercoating layer has a thickness of 0.1-5 탆. The photo paper for inkjet recording according to claim 1, wherein a backside coating layer is coated under the base layer.