JP2001121809A - Ink jet recording sheet and manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording sheet having high glossiness, good printing quality and ink dryability and improved adhesive properties of the surface of a polyolefin resin coating sheet with an ink receiving layer. SOLUTION: In the ink jet recording sheet comprising an ink receiving layer on at least one surface of a sheet-like support, the support is a polyolefin resin coating sheet providing a polyolefin resin composition layer on at least one surface of a paper base by melt extruding, the receiving layer is provided at the composition layer side, the surface of the composition layer has a fine ruggedness, and its centerline mean roughness is SRa=0.1 to 10 μm of a range (JIS B 0601).

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, the present invention relates to a high-quality ink jet recording sheet having good adhesion between a sheet-like support and an ink receiving layer, a high glossy surface, and excellent printing quality and ink drying property.

[0002]

2. Description of the Related Art An ink jet recording method is a recording method in which small droplets of ink are caused to fly from nozzles, and ink droplets are attached and absorbed on a recording sheet. Printers using this method are compatible with color printing, and are small in size and inexpensive as compared with other recording type printers. In recent years, with the advancement of personal computers and the spread of multimedia, there has been an increasing demand for printing documents including color and color photographs at work and at home. It is considered one of the.
Conventionally, as a recording sheet used in ink jet recording, it is necessary to apply an ink-absorbing resin or an ink-absorbing layer composed of various pigments and a water-soluble resin or various latexes on one side of a paper substrate, and further necessitate Accordingly, a recording sheet whose surface is smoothed by a super calendar process or the like is used. However, since these recording sheets had irregularities derived from pulp fibers on the surface of the paper substrate and had poor smoothness, only the finished ink jet recording sheet had insufficient gloss. Alternatively, when printing is performed, there is a problem that the portion that has absorbed the ink is stretched and the sheet is wavy. In order to compensate for the drawbacks of the paper substrate, an ink-jet printing machine that uses a polyolefin resin-coated sheet in which both sides of a base paper are coated with a polyethylene resin or various plastic sheets such as a polyester film as a sheet-like support, and is provided with an ink receiving layer. A recording sheet has been proposed and has achieved some results (for example, Japanese Patent Application Laid-Open Nos. 4-216990 and 7-327).
No. 23). However, because the polyolefin resin and the polyester resin are hydrophobic, the affinity between the surface of the sheet-like support and the ink absorbing layer is generally poor, so that coating defects such as repelling occur in the coating process, or There were problems such as insufficient adhesion between the ink receiving layer and the sheet-like support.

[0003] In order to solve these problems, prior to the coating of the ink receiving layer, a method of performing a surface activation treatment such as a corona treatment, or providing a subbing layer mainly composed of a water-soluble resin is used. It was performed, but did not have a sufficient effect.

[0004]

DISCLOSURE OF THE INVENTION The present inventors studied various ink jet recording sheets in which a polyolefin resin-coated sheet was mainly coated with an ink-absorbing resin, and used, for example, a cellulose resin as the ink-absorbing resin. It has been found that the obtained ink jet recording sheet is excellent in print quality, gloss, ink drying property and the like (for example, Japanese Patent Application Nos. 10-85926 and 10-27).
1347, Japanese Patent Application No. 10-228096), there is a problem that the cellulosic resin hardly adheres to the surface of the polyolefin resin-coated sheet, and there is a concern about occurrence of coating defects. SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording sheet having high glossiness, good print quality and good ink drying properties, and having improved adhesion between a polyolefin resin-coated sheet surface and an ink receiving layer. .

[0005]

The present invention includes the following aspects. [1] In an inkjet recording sheet having an ink receiving layer provided on at least one surface of a sheet-like support, the sheet-like support is provided by melt-extruding a polyolefin resin composition layer on at least one surface of a paper substrate. A polyolefin resin-coated sheet, wherein the ink absorption layer is provided on the polyolefin resin composition layer side, and the surface of the polyolefin resin composition layer has fine irregularities, and the center line average roughness is SRa = 0. An ink jet recording sheet having a range of 1 μm to 10 μm (JIS-B0601). [2] Surface glossiness of ink jet recording sheet (JI
(S-P8142) is 30% or more. [3] The ink jet recording sheet according to [1] or [2], wherein the ink receiving layer contains at least one cellulose resin. [4] In the method for producing an ink jet recording sheet comprising an ink receiving layer provided on the polyolefin resin composition layer side of a polyolefin resin composition sheet having a polyolefin resin composition layer on at least one surface of a paper substrate, at least one of the paper substrate In the step of providing a polyolefin resin composition layer on one surface, the polyolefin resin composition layer is provided by melt extrusion, the polyolefin resin composition layer is cooled and solidified using a cooling roll having fine irregularities, and the surface thereof is cooled. A method for producing an ink jet recording sheet, characterized by being formed with fine irregularities. [5] The surface of the polyolefin resin composition layer is formed with fine irregularities, and the center line average roughness is SRa =
The method for producing an inkjet recording sheet according to [4], wherein the inkjet recording sheet is adjusted to a range of 0.1 μm to 10 μm (JIS-B0601).

[6] The center line average roughness of the surface of the polyolefin resin composition layer is in the range of 0.5 μm to 5 μm (JIS-
B0601). The inkjet recording sheet according to [1], [2] or [3]. [7] Surface glossiness of inkjet recording sheet (JIS
-P8142) is 90% or more. [8] The ink receiving layer contains at least one of methylcellulose (MC), carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC), and hydroxypropylcellulose (HPC) [3]. The ink jet recording sheet according to the above. [9] The method for producing an ink jet recording sheet according to [4] or [5], wherein the cooling roll is made of chrome-plated iron and has fine irregularities formed by a sandblast method.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by forming fine irregularities on the surface of a polyolefin resin-coated sheet, The adhesiveness with the ink receiving layer is improved, and it is found that the glossiness of the inkjet recording sheet does not decrease in a specific range of surface roughness,
The present invention has been completed. That is, the inkjet recording sheet of the present invention is an inkjet recording sheet in which an ink receiving layer is provided on at least one surface of a sheet-like support, wherein the sheet-like support is a polyolefin resin composition on at least one surface of a paper substrate. Is a polyolefin resin-coated sheet obtained by melt-extruding, for example, in the step of melt-extruding the polyolefin resin composition on a paper substrate, the surface of the polyolefin resin composition is cooled and solidified using a cooling roll having fine irregularities, The surface of the polyolefin resin-coated sheet is molded with fine irregularities.

[0008] The sheet-like support according to the present invention is a polyolefin resin-coated sheet obtained by melt-extruding a polyolefin resin composition on at least one surface of a base paper. Base paper is composed mainly of wood pulp. As wood pulp, chemical pulp such as LBKP and NBKP, GP,
Various pulp such as mechanical pulp such as PGW, TMP, CTMP, CMP and CGP, and waste paper pulp such as DIP are exemplified. Furthermore, various conventionally known papermaking additives can be blended as needed. As papermaking additives, various papermaking pigments, binders, sizing agents, fixing agents,
Examples thereof include a retention improver, a cationizing agent, a dry paper strength enhancer, a wet paper strength enhancer, a pH adjuster, a conductive agent, and a dye. One or more of these materials can be blended. As the paper machine, a known fourdrinier paper machine, a cylindrical paper machine, a twin wire paper machine, or the like can be used. Also,
Any acidic, neutral or alkaline papermaking may be used. The base paper may be subjected to a tab size or size press with starch or polyvinyl alcohol, or a surface smoothness treatment with a machine calender, a heat calender, a soft calender, a super calender, etc., subsequent to the paper making. The thickness of the base paper is not particularly limited.
It is preferable that it is from μm to 500 μm. If the thickness is less than 30 μm, the rigidity of the ink jet recording sheet is low, and inconveniences such as a decrease in feel when touched by hand, texture, and opacity occur. On the other hand, if the thickness is more than 500 μm, it becomes rigid and difficult to handle, and a trouble may occur during paper feeding by a printer. The thickness of the base paper is not particularly limited, but is preferably in a range of about 30 to 500 g / m ² .

The polyolefin resin coating layer is formed by melt-coating a resin composition containing a polyolefin resin as a main component and, if necessary, a white pigment and various additives. Examples of the polyolefin resin include homopolymers and copolymers such as ethylene and propylene.
Seeds or two or more kinds can be used as appropriate. Among them, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, and polypropylene are preferred because they have good workability and are easily available. Although the physical properties of the polyolefin resin are not particularly limited, the molecular weight is preferably 20,000 due to suitability for processing and curl.
0-200,000, density 0.915-0.950 g
/ Cm ³ and the melt index are preferably in the range of 2 to 40 g / 10 min (JIS K-6760).

[0010] The polyolefin resin coating layer on the side on which the ink receiving layer is provided (the side on the front side) preferably contains a white pigment in order to increase whiteness and opacity and to make printed images clear. . As white pigments, anatase-type white titanium, rutile-type titanium dioxide, zinc oxide,
Examples thereof include calcium carbonate and talc, and one kind or a mixture of two kinds can be used. The particle size of the white pigment is generally 1 μm or less, but is preferably 0.5 μm or less in order to obtain a desired surface roughness. The blending amount of the white pigment is not particularly limited, but is 0.1 to 30 parts by weight based on 100 parts by weight of the polyolefin resin.If less than 0.1 part by weight, the effect of increasing whiteness or opacity is small, If it exceeds 30 parts by weight, dispersion in the olefin resin becomes difficult. The preferred range is 1 part by weight to 15 parts by weight.
Parts by weight. In order to enhance the dispersibility of the white pigment in the polyolefin resin, the surface of the pigment is aluminum or
Surface treatment with a silane coupling agent or the like is also possible. In addition to white pigments, additives such as dispersants, surfactants, colored pigments, dyes, optical brighteners, antioxidants,
A plasticizer or the like can be appropriately compounded. The mixing and dispersion of the white pigment into the polyolefin resin and the addition of additives are performed using a kneading extruder, a heating roll kneader, a Banbury mixer, a pressure kneader, or the like. The polyolefin resin coating layer is formed by a melt extrusion coating method. That is, a polyolefin resin composition melted by using an extruder is cast on a running base paper from a slit die into a film and coated. The temperature of the molten film at that time varies depending on the type of polyolefin resin.
0 ° C. to 350 ° C. is common. As the slit die, a T-type die, an L-type die, a fish-type die and a flat die are preferable, and the opening diameter of the slit is approximately 0.1 to
2 mm.

The cooling roll for cooling a molten resin film coated with a polyolefin resin of the present invention has fine irregularities on the surface. As a method of forming fine irregularities on the surface of the cooling roll, surface polishing, surface evaporation, sand blasting, etching, electrochemical corrosion, plating, etc. can be exemplified, among which sand blasting is effective. preferable. The material of the cooling roll can be exemplified by metals such as iron, stainless steel and aluminum.
The surface can be subjected to a surface treatment such as nickel plating, chrome plating, enamelling, and Teflon processing. The material of the cooling roll and the method of forming fine surface irregularities can be arbitrarily selected as long as a desired shape is obtained.However, from the viewpoint of effect, chrome plating is performed on the iron cooling roll and sand blasting is performed. It is preferable to apply.

Further, the pressing pressure of the cooling roll at the time of melt extrusion is not limited as long as a desired surface shape is obtained, but is generally from 10 to 100 kg / cm as a linear pressure. When the surface temperature of the cooling roll is increased, the releasability between the polyolefin resin coating layer and the cooling roll is deteriorated. Therefore, the surface temperature is reduced to 5 to 5 by a method such as circulating cooling water.
The temperature is preferably set to 0 ° C. from the viewpoint of processability. In the present invention, the center line average roughness of the surface of the polyolefin resin coating layer on which the ink receiving layer is provided is preferably 0.1 μm to
The thickness is adjusted to 10 μm, more preferably 0.2 μm to 7 μm, and most preferably 0.5 μm to 5 μm. If it is less than 0.1 μm, the effect of improving the adhesion may not be sufficiently obtained, while if it exceeds 10 μm, the surface gloss of the recording surface of the finally obtained recording medium is reduced. Therefore, it is preferable to adjust the thickness to 10 μm or less for applications requiring a high glossy recording surface and an excellent recording density. Although the reason why the coating defects of the ink receiving layer coating are suppressed by the present invention is not necessarily clear, due to fine irregularities on the surface, bubbles are generated between the wet coating film of the ink receiving layer coating liquid and the support. This is presumed to be due to the effect of preventing the entry of

The surface opposite to the surface on which the ink receiving layer is provided (surface on the back side) can be coated with the polyolefin resin composition. The coating amount of the polyolefin resin coating layer is not particularly limited, but on the front side and the back side of the base paper,
Is 5g / m ² ~50g / m ^2, respectively. If the amount is less than 5 g / m ² , problems such as insufficient adhesion to the base paper and a uniform resin coating layer cannot be obtained. 50g / m
^{If the number} exceeds ² , the sheet-like support becomes thicker, and the curl increases, or the cost rises unnecessarily. A preferred range is from 10 g / m ² to
30 g / m ² . Polyolefin resin coating layer is 1
It may be a layer or a configuration of two or more layers.
In the case of two or more layers, the same resin composition may be laminated, or different resin compositions may be laminated. Two or more layers may be simultaneously coated by a co-extrusion method. Furthermore, the surface of the polyolefin resin coating layer on which the ink receiving layer is to be provided is subjected to a surface activation treatment such as corona treatment or a small amount of a water-soluble resin for the purpose of improving the adhesiveness with the ink receiving layer. Then, an undercoat layer may be provided. Also, on the back side of the polyolefin resin coating layer, that is, on the side opposite to the side on which the ink receiving layer is provided, the purpose of suppressing curling of the completed ink jet recording sheet, or improving the printer transportability, or the antistatic ability and writing property. A backside coating layer can also be provided for the purpose of imparting, for example,

The ink receiving layer of the present invention is not particularly limited as long as desired printability is obtained, but preferably contains at least one ink absorbing resin. The ink-absorbing resin is a resin having an ability to absorb ink ejected when printing with an ink jet printer, such as polyvinyl alcohol, cationized polyvinyl alcohol, and modified polyvinyl alcohol such as silanol-modified polyvinyl alcohol, polyvinyl pyrrolidone, and modified polyvinyl alcohol. Polyvinylpyrrolidone, gelatin, modified gelatin, casein, soy casein, modified soy casein, starch, oxidized starch, etherified starch, various starch derivatives such as phosphated starch, carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxypropylmethylcellulose and the like Examples include water-soluble resins such as cellulose derivatives and water-dispersible resins such as vinyl acetate copolymer. A water-soluble resin is preferable in terms of absorbability. Above all, an ink receiving layer containing a cellulose derivative, polyvinylpyrrolidone and a cationic resin has advantages such as good ink drying properties, excellent image quality, and less stickiness, and is preferred.

In the ink receiving layer, in addition to the ink absorbing resin, a cationic resin, an antiblocking agent, an ink fixing agent, a pigment, a pigment dispersant, a thickener, a fluidity improver, a surfactant, a defoamer , Foam inhibitor, penetrant, coloring dye, coloring pigment,
A fluorescent whitening agent, an ultraviolet absorber, an antioxidant, an antiseptic, an antiseptic, a water-proofing agent and the like can be appropriately compounded. The cationic resin functions as an ink fixing agent.
Dyes used in ink jet printer inks,
For example, various resins that form insoluble salts with sulfonic acid groups, carboxyl groups, amino groups, etc. of aqueous direct dyes and water-soluble acid dyes, and various resins containing secondary amines, tertiary amines, quaternary ammonium salts, etc. Cationic resins can be exemplified. For example, polyethyleneimine, polyvinylpyridine, polydialkylaminoethyl methacrylate, polydialkylaminoethyl acrylate, polydialkylaminoethyl methacrylamide, polydialkylaminoethylacrylamide, polyepoxyamine, polyamideamine, dicyandiamide-formalin condensate, dicyandiamide polyalkyl- Examples include compounds such as polyalkylene polyamine condensates, polydimethyldiallylammonium chloride, polyvinylamine, and polyallylamine, and modified products thereof. Blocking can be prevented by adding a pigment. When a pigment of several μm is added as a pigment, if added in a large amount, there is a possibility that the gloss may decrease, and there is no particular limitation, but 10 parts by weight or less based on 100 parts by weight of the ink absorbing resin.
It is preferably at most 3 parts by weight, more preferably at most 1 part by weight. Further, when the pigment particle size is 1 μm or less, since the decrease in gloss is small, the amount of the pigment added can be increased to improve the ink absorbency. In this case, about 400 parts by weight or less can be added. The particle size (aggregate particle size for a pigment forming an aggregate particle size) is preferably 600 nm or less.

The coating amount of the ink receiving layer of the present invention is 3 to 30 g / m ² in terms of dry weight. If the amount is less than 3 g / m ^2, the ink for full-color printing may not be able to be absorbed.
If it exceeds m ² , the resulting ink jet recording sheet may not only be thickened, but also may be incurred or curled, or may have disadvantages such as increased cost. Gloss of recording surface, that is, ink receiving layer surface (JIS-P8142,
75% gloss) is preferably 30% or more, more preferably 50% or more, still more preferably 70%, and most preferably 8%.
0% or more. Thereby, recording excellent in recording density and image glossiness can be obtained. The ink receiving layer of the present invention can be applied by a known method. For example, it can be appropriately selected from various coating methods such as various blade coaters, roll coaters, air knife coaters, bar coaters, rod blade coaters, short dwell coaters, gravure coaters, extrusion coaters, and curtain coaters.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto. Unless otherwise specified, the coating amount indicates a dry coating amount. [Examples 1 to 5] [Production of base paper] Softwood bleached kraft pulp (NBKP) 20
A mixed pulp of 80 parts by weight of hardwood bleached kraft pulp (LBKP) is beaten to 280 ml of Canadian freeness with a double disc refiner, and the following papermaking chemicals are added in the following amounts based on the absolute dry weight of the pulp. And stir well to disperse to a concentration of 0.5%
Was prepared. Pulp (mixed pulp of NBKP / LBKP): 100 parts by weight, alkyl ketene dimer 0.4 part by weight, cationized starch 2.0%, cationic polyacrylamide resin 0.1%, polyamide polyamine epichlorohydrin resin 0.7%, The pH was adjusted to 7.5 by adding aqueous sodium hydroxide.

The pulp slurry having the above composition is paper-made by a fourdrinier machine, passed through a drier, a size press, and a machine calender, and has a basis weight of 180 g / m ² , a tightness of 1.0 g / cm ³ and a water content of 7.5%. Base paper was manufactured. The composition of the size press liquid is as follows. 2 parts by weight of carboxyl-modified polyvinyl alcohol, 1 part by weight of sodium chloride The concentration of the size press solution was adjusted to 5%, and this solution was coated on both sides of the paper so that the coating amount of the coating solution was 25 g / m ² (dry coating). 1.25 g / m ² ).

[Coating of Polyolefin Resin Coating Layer] After applying corona discharge treatment to both the front and back surfaces of the base paper, a polyolefin resin composition 1 having the following composition mixed and dispersed by a Banbury mixer was added to the wire side of the base paper ( Back side)
Was applied by a melt extruder (melting temperature: 280 ° C.) having a T-die so that the coating amount was 25 g / m ² . Subsequently, the polyolefin resin composition 2 was coated on the felt side (front side) of the base paper so that the coating amount was 30 g / m ² . In this case, a cooling roll was used in which the surface of an iron roll was chrome-plated, and the surface was finely roughened by sandblasting. Various types of surface roughness shown in Table 1 were obtained by adjusting the type of particles and the processing time of the sandblasting treatment (Examples 1 to 3).
5).

Olefin resin composition 1 65 parts by weight of high density polyethylene resin (density 0.945, melt index 20 g / 10 min), 35 parts by weight of low density polyethylene resin (density 0.914, melt index 4 g / 10 min)

Olefin resin composition 2 35 parts by weight of linear low-density polyethylene resin (density 0.926, melt index 20 g / 10 min), low-density polyethylene resin (density 0.919, melt index 2 g / 10 min) 50 Parts by weight, anatase type titanium dioxide (manufactured by Ishihara Sangyo, trademark: A-2
20) 10 parts by weight, zinc stearate 0.1 part by weight, antioxidant (manufactured by Ciba-Geigy, trademark: Irganox1)
010) 0.03 parts by weight, ultramarine (Daiichi Kasei, trademark: Aoguchi ultramarine No. 2000)
0.09 parts by weight, a fluorescent whitening agent (trade name: UVITEX O, manufactured by Ciba Geigy)
B) 0.3 parts by weight

[Coating of Back Layer] After the surface of the polyolefin resin coating layer on the back side is subjected to a surface activation treatment by corona treatment, a back layer composition 1 having the following composition is applied in an amount of 1
Coating was performed so as to be 0 g / m ² . Back layer composition 1 95 parts by weight of carboxymethyl cellulose (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Cellogen 7A), 5 parts by weight of polyester resin dispersion (manufactured by Takamatsu Yushi, trade name: Pesresin A-513E), surfactant (Dainippon) 0.05 parts by weight, manufactured by Ink Chemical Industry Co., Ltd., trade name: Mizukasil P-52, manufactured by Mizusawa Chemical Industry Co., Ltd.
6) 5 parts by weight

[Coating of Ink Receiving Layer] The surface of the polyolefin resin coating layer on the front side is subjected to a surface activation treatment by corona treatment, and then the undercoat layer 1 having the following composition is coated in an amount of 0.1%.
Coating was performed with a bar coater so as to be 1 g / m ² . Further, the coating amount of the ink receiving layer composition 1 was 15 g / m.
^The composition was coated with a die coater so as to be ² (Examples 1 to 3). Undercoat layer composition 1 100 parts by weight of gelatin (manufactured by Miyagi Chemical Co., acid-treated beef bone gelatin), surfactant (manufactured by Kao, trademark: Emal E27C) 0.0
5 parts by weight Ink receiving layer composition 1 75 parts by weight of hydroxypropyl methylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: Metroose 65SH-50), 20 parts by weight of polyvinylpyrrolidone (manufactured by BASF, trade name: rubiscol K-17), as a cationic resin 5 parts by weight of allylamine / diallylamine hydrochloride (manufactured by Nitto Boseki, trademark: PAA-D11-HCL), 0.2 parts by weight of starch particles (manufactured by Oji Cornstarch, trademark: Ace A) as a blocking inhibitor.

After the surface of the polyolefin resin coating layer on the front side is subjected to a surface activation treatment by corona treatment, the ink receiving layer composition 2 is coated with a die coater so that the coating amount is 25 g / m ^2. Coated. (Example 4,
5) Ink receiving layer composition 2 95 parts by weight of polyvinylpyrrolidone (manufactured by BASF, trade name: rubiscol K-90), 5 parts by weight of allylamine / diallylamine hydrochloride (manufactured by Nitto Boseki, trade name: PAA-D11-HCL) as a cationic resin 0.2 parts by weight of silica particles (trade name: P-78F, manufactured by Mizusawa Chemical Industries) as a blocking inhibitor.

[Comparative Examples 1 and 2] Base paper was coated in the same procedure as in Example 1 except that a cooling roll which had not been subjected to sandblasting but was mirror-finished was used for coating the polyolefin resin coating layer on the front side. And the front and back were coated with a polyolefin resin composition to produce a sheet-like support. Then, after the back layer was applied in the same procedure as in Example 1, the corona treatment and the undercoat layer were applied in the same procedure as in Example 1, and then the ink receiving layer was applied in the same manner as in Example 1. An ink jet recording sheet was completed (Comparative Example 1). A base paper was formed by the same procedure as in Example 1 except that a cooling roll that had not been sandblasted with a mirror-finished surface was used to coat the polyolefin resin coating layer on the front side, and the front and back surfaces of the polyolefin resin composition were used. To produce a sheet-like support. Then, after the back layer was applied in the same procedure as in Example 1, the ink receiving layer was applied only by corona treatment without providing an undercoat layer, thereby completing ink jet recording (Comparative Example 2).

Example 6 In coating a polyolefin resin coating layer on the front side, a rough surface was used by using a cooling roll provided with large irregularities by sandblasting.
According to the same procedure as described above, the front and back were coated with the polyolefin resin composition to produce a sheet-like support. Further, in the same procedure as in Example 1, a back layer and an ink receiving layer were provided to complete an ink jet recording sheet.

Comparative Example 3 After a base paper was manufactured in the same procedure as in Example 1, a back layer and an ink receiving layer were provided in the same procedure as in Example 1 without providing a polyolefin layer on the front and back sides, thereby completing an ink jet recording sheet. Was. Table 1 shows the evaluation results of the ink jet recording sheets of Examples 1 to 6 and Comparative Examples 1 to 3 produced by the above procedure.

[Surface Roughness of Polyolefin Resin Coating Layer]
According to the method of IS-B0601, the center line average roughness SRa of the surface of the polyolefin resin coating layer was measured with a stylus type measuring instrument. [Adhesion between ink receiving layer and polyolefin resin coating layer]
The ink receiving layer was cut with a razor to make five parallel scratches at intervals of 3 mm, and the same direction was applied in a direction perpendicular to the five scratches.
Scratched book. After a cellophane tape was stuck on the perpendicular wound, the cellophane tape was peeled off in the direction of 180 degrees with respect to the adhesive surface, and this mark was judged according to the following criteria. ：: No peeling of the ink receiving layer. ×: peeling was observed in the area surrounded by the wound. XX: Peeling occurred regardless of the presence or absence of scratches.

[Gloss] According to the method of JIS-P8142, 7
The specular gloss was measured at 5 degrees. [Print quality] Inkjet printer (ENCAD,
(Trademark: NOVAJET PRO, GO ink installed) in black, cyan, magenta, and yellow, and
A mixed color of red, green, and blue was printed, and the uniformity of the printed portion was visually observed. ◎: No shading or cracks were observed in the printed portion. 〇: Slight unevenness and cracking are slightly observed. X: The density unevenness and cracking are remarkable.

[Ink Drying Property] After printing with the printer described above, high quality paper was overlaid at regular intervals, and the presence or absence of ink transfer was evaluated. ◎: No transfer occurred 10 minutes after printing. 〇: No transfer after 10 to 30 minutes of printing. ×: Transference occurred 30 minutes after printing.

[0031]

[Table 1]

As is clear from the results shown in Table 1, the ink jet recording sheets shown in Examples of the present invention have good adhesion between the ink receiving layer and the polyolefin layer, high glossiness, and high print quality. And excellent ink drying properties. In contrast, Comparative Example 1 used a mirror-finished cooling roll, so that the finished ink jet recording sheet had a higher surface gloss than the example and was good. Adhesion decreased. In Comparative Example 2, the adhesion was further reduced because the undercoat layer was not provided. In Example 6, since a cooling roll having large surface irregularities was used,
Glossiness decreased. In Comparative Example 3, only a very low gloss was obtained because no polyolefin resin coating layer was provided.

[0033]

According to the present invention, it is possible to obtain an ink jet recording sheet having high gloss, good printing quality and good ink drying property, and having improved adhesion between the surface of the polyolefin resin-coated sheet and the ink receiving layer. it can.

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Claims (5)

[Claims] In an ink jet recording sheet having an ink receiving layer provided on at least one surface of a sheet-like support, the sheet-like support melt-extrudes a polyolefin resin composition layer on at least one surface of a paper substrate. A polyolefin resin-coated sheet provided, wherein the ink receiving layer is provided on the polyolefin resin composition layer side,
The surface of the polyolefin resin composition layer has fine irregularities and its center line average roughness is SRa = 0.1 μm to 10 μm
m (JIS-B0601). 2. The ink jet recording sheet according to claim 1, wherein the surface glossiness (JIS-P8142) of the ink jet recording sheet is 30% or more. 3. The ink receiving layer according to claim 1, wherein the ink receiving layer contains at least one cellulose resin.
3. The ink jet recording sheet according to item 1. 4. A method for producing an ink jet recording sheet comprising a polyolefin resin-coated sheet having a polyolefin resin composition layer on at least one surface of a paper substrate and an ink receiving layer provided on the polyolefin resin composition layer side. In the step of providing a polyolefin resin composition layer on at least one surface of the polyolefin resin composition layer is provided by melt extrusion, the polyolefin resin composition layer is cooled and solidified using a cooling roll having fine irregularities, and the A method for producing an ink jet recording sheet, characterized in that the surface is molded with fine irregularities. 5. The surface of the polyolefin resin composition layer is formed with fine irregularities, and the center line average roughness is SRa.
= 0.1 μm to 10 μm range (JIS-B0601)
5. The method for producing an ink jet recording sheet according to claim 4, wherein the method is adjusted to: