JP2003251933A - Ink jet recording sheet for oil-based ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recording sheet for oil-based ink of which the swelling is reduced, of which the phenomenon of waviness is prevented and which is excellent in a print density. <P>SOLUTION: In regard to an ink jet recording sheet having a base and at least one ink receiving layer, the ink jet recording sheet for oil-based ink has at least one barrier layer between the base and the ink receiving layer. The barrier layer contains (a) a vinylidene chloride resin or (b) a resin which is an acrylonitrile-butadiene-styrene copolymer and of which the acrylonitrile constituent is 15 wt.% or more and the butadiene constituent 10-35 wt.% in a monomer weight ratio, or (c) the mixture of these resins. <P>COPYRIGHT: (C)2003,JPO

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, and more particularly to an ink jet recording sheet for oil-based ink, in which a base material is swollen by a solvent contained in the oil-based ink and the sheet itself is wavy. The present invention relates to an inkjet recording sheet for oil-based ink having a preventing function.

[0002]

2. Description of the Related Art In the printing of printed matter requiring water resistance, for example, posters used outdoors, it is necessary to use an oil-based ink using an organic solvent as a solvent.
There are cases where a low-boiling organic solvent is used as the organic solvent and a high-boiling organic solvent is used, but a low-boiling solvent is easily dried and has a problem that the inkjet nozzle is likely to be clogged. As the oil-based ink, an organic solvent having a relatively high boiling point is usually used.

However, when an oil-based ink containing a solvent having a high boiling point as a solvent is used, the solvent in the ink is difficult to dry, so that the solvent penetrates into the ink receiving layer and further into the substrate, and the substrate becomes oily. There is a problem that the sheet swells due to the solvent of the ink and the sheet itself becomes wavy. In addition, since the solvent is hard to dry, the oil-based ink bleeds out on the back surface of the paper, and stains and stains are easily formed. This is particularly noticeable when the base material is made of a polyolefin based material in order to reduce the cost of the sheet, and it cannot be practically used as an inkjet recording sheet for oil-based ink. Furthermore, when a plurality of inkjet recording sheets on which an image is printed by using an oil-based ink are stacked and stored, the solvent of the ink permeates the substrate from the back surface of the inkjet recording sheet, so that the substrate swells and the inkjet recording There was a problem that the recording sheet was wavy. In addition, there is a problem that an image is transferred to the back surface of the inkjet recording sheet, which causes a problem that the image density is lowered and the image blurring is deteriorated.

For this reason, it has been attempted to have a two-layer base material as a printer paper in which the oil-based ink is prevented from seeping out to the back surface of the paper, and to form a permeation preventive layer between the base materials. (Patent Document 1). However, in this case, it is possible to prevent the oil-based ink from seeping out on the back surface of the inkjet recording sheet to form spots or stains, but it contacts the ink receiving layer of the two-layer base material. Since the solvent penetrates into one of the base materials, it was not sufficient to achieve the object of the present invention to prevent the corrugation of the sheet. Further, an inkjet recording sheet for oil-based ink has been proposed in which a back coat layer made of an oil-soluble dye-non-dyeing resin is provided on the back surface of a base material (Patent Document 2), but penetration of a solvent from an ink receiving layer is prevented. It was not possible to achieve the object of the present invention. Further, there is also known an inkjet recording sheet for oil-based ink in which a barrier layer made of an oil-soluble dye non-dyeing resin such as acrylonitrile-butadiene rubber (NBR) is provided between a support and an ink receiving layer (Patent Document 3). ) In this case, although the printing quality can be improved, the penetration of the oil-based ink cannot be sufficiently prevented.

[0005]

[Patent Document 1] JP-A-11-254815 (first
page)

[Patent Document 2] Japanese Patent Laid-Open No. 10-264502 (first
page)

[Patent Document 3] Japanese Patent Laid-Open No. 10-264499 (first
(1 page)

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording sheet for oil-based ink, which can prevent the sheet from swelling and prevent the sheet from waving.

[0007]

The present inventor has completed the present invention by discovering that the above problems can be solved by the following constitution after earnest research. That is,
(1) In an inkjet recording sheet having a substrate and at least one ink receiving layer, a barrier layer is provided between the substrate and the ink receiving layer, and the barrier layer is (a).
Vinylidene chloride resin, or (b) acrylonitrile-
A butadiene-styrene copolymer, an oil-based ink containing a resin having an acrylonitrile component of 15% by weight or more and a butadiene component of 10 to 35% by weight in a monomer weight ratio, or (c) a mixture of these resins. (2) A back surface layer is provided on the opposite side of the substrate from the surface having the ink receiving layer, the back surface layer comprising:
(A) a vinylidene chloride resin or (b) an acrylonitrile-butadiene-styrene copolymer, which is a resin in which the acrylonitrile component is 15% by weight or more and the butadiene component is 10 to 35% by weight in a monomer weight ratio, Alternatively, (c) the inkjet recording sheet for oil-based ink according to (1) above, which contains a mixture of these resins.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The ink jet recording sheet for oil-based ink of the present invention is characterized by having a substrate, at least one ink receiving layer, and a barrier layer between the substrate and the ink receiving layer. The substrate of the present invention is not particularly limited as long as it has a sheet shape. That is, the substrate itself may be adversely affected by the solvent in the oil-based ink, such as swelling, waviness, and stains. Specifically, various materials such as plastic films and papers may be used. Can be used. Among these materials, a plastic film is preferable from the viewpoint that water resistance and strength can be imparted to the inkjet recording sheet, and a polyolefin film is particularly preferable from the viewpoints of manufacturing cost, handleability, processability, and the like. The polyolefin film is preferably a film of polyethylene, polypropylene or the like, a copolymer thereof, a blend or a cross-linked product thereof, and a polypropylene film is particularly preferable. Further, as the base material, it is also possible to use one in which an inorganic powder such as calcium carbonate is internally added, one in which an organic pigment is internally added, and further, various foamed plastics including a microvoid film, It is also possible to use a multi-layered one. The plastic film referred to here also includes what is called synthetic paper.

If desired, one or both surfaces of the base material may be subjected to a surface treatment by an oxidation method or a concavo-convex method for the purpose of improving the adhesiveness and the leakage property. Examples of the oxidation method include corona discharge treatment,
Chromium oxidation treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment, etc. may be mentioned, and as the concavo-convex method, for example, a sandblast method, a solvent treatment method, etc. may be mentioned. These surface treatment methods are appropriately selected according to the type of the base material, but in general, the corona discharge treatment method is preferably used in terms of effects and operability. Also, an easy adhesion treatment can be applied. The thickness of the base material is not particularly limited and can be appropriately selected depending on the application, but is usually 10 to 400 μm.
m, for example, 50 to 200 μm is preferable when it is used for producing a general poster.

Next, in the present invention, the ink receiving layer means not only a layer on which ink is directly jetted but also all layers provided on a substrate and having an ability to absorb ink. The present invention has at least one or more ink receiving layers, which are formed by binding a filler, which is a powder or pigment having good ink absorbability, with a binder. The substance that can be used as the filler is not limited to organic or inorganic, and examples thereof include calcium carbonate, silica, talc, clay, diatomaceous earth, aluminum hydroxide, polystyrene, polymethacrylate, titanium oxide, and calcined kaolin. In particular, an inorganic filler, particularly silica is preferable from the viewpoint of printability for oil-based ink. These fillers can be used alone or in combination of two or more.

In the present invention, a substance suitable as a binder to be added is a polymer, and specifically, acrylic resin, polyester, urethane resin, acrylic ester resin, chlorinated polypropylene, versatic acid vinyl resin, polyvinyl alcohol, Polyvinyl butyral, gelatin, polyvinyl acetal, carboxymethyl cellulose, polyvinylpyrrolidone, copolymers thereof, styrene-acrylic copolymer, ethylene-vinyl acetate copolymer, styrene-butadiene rubber, acrylic rubber and the like, but in particular, Acrylic ester resins are preferred from the viewpoint of good printability for oil-based inks. In addition, it is preferable to use a chlorinated polypropylene, a vinyl versatate resin, or the like that has a large property of swelling in the solvent of the oil-based ink, because it has an effect of preventing fading.
Further, as the substance suitable for the binder, one type may be used alone, or two or more types may be used in combination, but when a substance having a property of easily swelling in the solvent of the oil-based ink is mainly used. In order to maintain the strength of the layer after printing, it is preferable to use it by mixing with a resin that does not swell in the solvent of the oil-based ink.

Furthermore, the total solids weight of the ink receiving layer is
It is preferably in the range of 5 to 50 g / m ² . 5 g /
If it is less than m ² , blurring of the image is likely to occur, and 50 g / m ²
If it exceeds, the strength of the layer may be inferior. The thickness of the ink receiving layer is such that when the ink receiving layer is a single layer, the total thickness of the ink receiving layer is 30 to 30 when the ink receiving layer has a plurality of ink receiving layers. 70
The range of μm is preferable, and the range of 40 to 55 μm is particularly preferable. When the thickness of the ink receiving layer is less than 30 μm, the ink absorbency is poor and the image may be blurred and blurred. On the other hand, when the thickness of the ink receiving layer is more than 70 μm, the color developability may be deteriorated and it may be difficult to dry. Therefore, the surface of the layer is likely to be cracked, and banding may occur. In the ink receiving layer, if necessary, a defoaming agent, an antistatic agent, an ultraviolet absorber, a fluorescent brightening agent, a preservative,
A pigment dispersant and a thickener can be mixed.

The present invention is characterized by having at least one barrier layer between the ink receiving layer and the substrate. The barrier layer is a layer having a function of preventing the solvent in the oil-based ink from reaching the base material, and the barrier layer is (a) vinylidene chloride resin or (b) acrylonitrile-butadiene-styrene copolymer. Therefore, it is essential to contain a resin having an acrylonitrile component of 15% by weight or more and a butadiene component of 10 to 35% by weight in a monomer weight ratio, or (c) a mixture of these resins. The barrier layer prevents the ink solvent in the ink receiving layer of the printed sheet from penetrating to the base material of the sheet, thereby preventing the sheet base material from waviness due to the ink solvent. The vinylidene chloride resin here may be a resin of vinylidene chloride alone or a copolymer with another monomer. As the other monomer in the case of a copolymer, various kinds can be selected, but vinyl chloride, acrylonitrile, acrylic acid ester and the like are preferable. The method for producing the vinylidene chloride resin is not particularly limited, but emulsion polymerization or suspension polymerization is usually used, and a coating liquid can be prepared by adjusting the viscosity of the emulsion or suspension state with water, etc. Is.

Further, the acrylonitrile-butadiene-styrene copolymer is a copolymer of monomers containing at least a styrene component, a butadiene component and an acrylonitrile component, and the acrylonitrile component is 15% by weight or more in a monomer weight ratio, and Butadiene component is 10
The resin is 35% by weight, but the raw material monomer may be one in which methyl methacrylate or unsaturated carboxylic acid is used in combination with the above three components. It is presumed that one of the reasons that the barrier property of the oil-based ink against the solvent is exhibited is that the copolymer has 15% by weight or more of an acrylonitrile component having high polarity and strong polymer cohesive force. Further, if the butadiene component is 10% by weight or more, ink bleeding can be prevented and the print quality can be favorably affected, and if it is 35% by weight or less, the absorption of the solvent of the oil-based ink is suppressed to a low level, and the barrier property is secured. can do. This copolymer is commercially available, for example, as an aqueous dispersion (latex) of polymer particles having a particle size of 0.05 to 1 μm, which is synthesized by emulsion polymerization. Can be used as a coating liquid. Further, the acrylonitrile-butadiene-styrene copolymer resin and vinylidene chloride resin may be mixed and used.

The thickness of the barrier layer is preferably 1 to 10 μm, particularly preferably 3 to 8 μm. If it is less than 1 μm, the object of the present invention, which is to prevent the solvent from penetrating into the substrate, may not be sufficiently achieved.
If it exceeds μm, cracks will occur in the barrier layer,
As a result, there may be a problem that the adhesion strength with the ink receiving layer is lowered.

In the present invention, a back surface layer is provided on the side of the substrate opposite to the surface having the ink receiving layer, and the back surface layer comprises (a) vinylidene chloride resin or (b) acrylonitrile-butadiene-. It is preferable that the resin is a styrene-based copolymer having an acrylonitrile component of 15% by weight or more and a butadiene component of 10 to 35% by weight in a monomer weight ratio, or (c) a mixture of these resins. With such a configuration, when the printed sheets are stacked, the ink solvent in the ink receiving layer of the lower sheet does not penetrate into the base material of the upper sheet, and the sheet when the sheets are stacked Can be prevented from waving. The vinylidene chloride resin used for the back surface layer is the same resin as described for the barrier layer, and may be a homopolymer or a copolymer with another monomer. . The vinylidene chloride resin used in the barrier layer and the vinylidene chloride resin used in the back surface layer may be the same or different, but from the viewpoint of ease of production, production cost, etc., the barrier layer and the back surface are It is preferable to use the same vinylidene chloride resin for the layers.

As with the barrier layer, the thickness of the back surface layer is preferably 1 to 10 μm, and particularly preferably 3 to 8 μm. If it is less than 1 μm, the object of the present invention of preventing the solvent from penetrating into the base material may not be sufficiently achieved, and if it exceeds 10 μm, cracks may occur in the back surface layer to improve the appearance. Inconvenience such as damage may occur.

In the present invention, it is essential to have at least one barrier layer between the ink receiving layer and the substrate,
There may be a plurality of ink receiving layers. When there are a plurality of ink receiving layers, the effect of the present invention can be obtained if a barrier layer is provided between any one of these ink receiving layers and the substrate, but the functions of the plurality of ink receiving layers are sufficiently exhibited. For this purpose, it is preferable to provide a barrier layer between the ink receiving layer closest to the substrate and the substrate. Further, in addition to the ink receiving layer, the barrier layer, and the back surface layer, layers having other functions can be provided, and the configurations of these layers are not limited at all. That is, an anchor coat layer, an ultraviolet absorbing layer, etc. may be provided in addition to these layers.

For forming the ink receiving layer, the barrier layer, the back surface layer and other layers, various conventionally known methods such as coating, spraying and dipping can be used. Especially, reverse roll coat, air knife coat, gravure coat,
Coating by blade coating is desirable. In addition, various conventionally used additives such as a surfactant, a lubricant, a stabilizer, and a coloring agent can be added to the coating liquid. In addition, a desired ink receiving layer is formed by performing a drying process after coating, but the drying process is
100 to 120 ° C. by a usual method such as hot air drying
It is desirable to carry out at a moderate temperature.

The above-mentioned (a) vinylidene chloride resin or (b) an acrylonitrile-butadiene-styrene copolymer, wherein the acrylonitrile component is 15% by weight or more and the butadiene component is 10 to 35 in a monomer weight ratio.
The barrier layer or the back surface layer containing the resin in the amount of% by weight, or (c) the mixture of these resins is formed on the substrate by various methods as described above, and the resin or the mixture of the resins is dispersed in water. It is preferable to form the coating liquid prepared by preparing the coating liquid or the coating liquid prepared by dissolving the resin or the mixture of the resins in the solvent. This coating liquid can be mixed with various substances as long as the effect as a barrier layer or a back surface layer is not impaired. For example, an inorganic or organic filler may be included for the purpose of preventing blocking, or defoaming may be performed. It is also possible to mix agents and the like.

[0021]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Evaluation was performed by printing on a commercially available oil-based ink with a commercially available ink-jet printer for an ink-jet recording sheet prepared according to Examples 1 to 5 and Comparative Examples 1 to 3, and various evaluations were performed by the following methods. went. (1) Evaluation of swelling and waviness An inkjet recording sheet produced according to each of the examples and comparative examples was printed with two colors. There are three types of color combinations, cyan and magenta, cyan and yellow, magenta and yellow, and cyan, magenta, and yellow are 100% monochromatic. Left alone: After printing, the printed matter was left standing at room temperature and normal humidity for 48 hours, and then the occurrence of waviness was visually confirmed. Leaving them on top of each other; leaving two sheets so that the print screens of other prints come into contact with the back surface of the print object to be evaluated, and visually confirming the occurrence of waving of the inkjet recording sheet to be evaluated. confirmed. The evaluation was performed according to the following criteria. ○: Flat with no waviness ×: Wavy (2) Printing density 100% solid printing was performed with each color of cyan, magenta, yellow, and black, and Macbeth densitometer RD-9
The reflection density was measured using 18.

Example 1 A suspension containing vinylidene chloride (“Saran Latex L536B” manufactured by Asahi Kasei Corp., solid content concentration 49%) was used as a coating liquid A for a barrier layer and a back surface layer. Then, 16 parts by weight of silica (“Sylysia 450” manufactured by Fuji Silysia Chemical Ltd., solid content concentration 100% by weight) as a filler, chlorinated polypropylene (“Hardlen EH-202” manufactured by Toyo Kasei Kogyo KK, solid content concentration 20) as a binder. % By weight) and acrylic acid ester (“NK polymer AC-117N” manufactured by Shin Nakamura Chemical Co., Ltd., solid content concentration 3)
28 parts by weight (4% by weight) and 38 parts by weight of water were homogeneously mixed to prepare a coating liquid B for the ink receiving layer. Next, the coating liquid A was applied to both sides of a polypropylene film [Yupo FPG # 80] manufactured by YUPO Corporation] having a thickness of 80 μm.
Coating was performed so that the coating thickness after drying was 5 μm. After the coating liquid A is dried, the coating liquid B is applied to one surface so that the coating thickness is 50.
The ink-jet recording sheet as shown in FIG. 1 was prepared by coating and drying so as to have a thickness of μm, and the above evaluation was performed. The evaluation results are shown in Table 1.

Example 2 A suspension containing vinylidene chloride instead of the coating liquid A of Example 1 (“Saran Latex L529” manufactured by Asahi Kasei Corp.)
B ”, the solid content concentration was 49%), and an inkjet recording sheet was prepared and evaluated in the same manner as in Example 1 except that the coating liquid C was used. The evaluation results are shown in Table 1.

Example 3 The coating liquid A described in Example 1 was applied only to the surface on which the ink receiving layer was formed in order to form a barrier layer, and was not applied to form the back surface layer. An inkjet recording sheet was prepared and evaluated in the same manner as in Example 1 except for the above.
The evaluation results are shown in Table 1. Example 4 Instead of the coating liquid A of Example 1, acrylonitrile-butadiene-styrene copolymer latex (“latex F1064” manufactured by Asahi Kasei Corporation, solid content concentration 50% by weight, styrene 38% by weight in all monomer components, Butadiene 30
Wt%, acrylonitrile 18 wt%) coating liquid D
An inkjet recording sheet was prepared and evaluated in the same manner as in Example 1 except that the above was used. The evaluation results are shown in Table 1. Example 5 Instead of the coating liquid A of Example 1, acrylonitrile-butadiene-styrene copolymer latex (“latex F1150” manufactured by Asahi Kasei Corporation, solid content concentration 50% by weight, styrene 36% by weight in all monomer components, Butadiene 31
Wt%, acrylonitrile 18 wt%) coating liquid E
An inkjet recording sheet was prepared and evaluated in the same manner as in Example 1 except that the above was used. The evaluation results are shown in Table 1.

Comparative Example 1 A suspension containing an acrylic resin (“Acronal YJ6221D” manufactured by BASF Dispersion) was adjusted to a solid content of 49%, and a coating liquid F was obtained.
And The same substrate as in Example 1 was used, and one surface of the substrate was coated with the coating liquid F so that the coating thickness after drying was 5 μm. After drying the coating liquid F, the coating liquid B described in Example 1 was applied thereon and dried to a coating thickness of 50 μm, and an inkjet recording sheet was prepared and evaluated. . The evaluation results are shown in Table 1. Comparative Example 2 Instead of the coating liquid A of Example 1, acrylonitrile-butadiene-styrene copolymer latex (“latex F1574” manufactured by Asahi Kasei Corporation, solid content concentration 50% by weight, styrene 52% by weight in all monomer components, Butadiene 32
Wt%, acrylonitrile 11 wt%) coating liquid G
An inkjet recording sheet was prepared and evaluated in the same manner as in Example 1 except that the above was used. The evaluation results are shown in Table 1. Comparative Example 3 Instead of the coating liquid A of Example 1, acrylonitrile-butadiene-styrene copolymer latex (“latex R1199” manufactured by Asahi Kasei Corporation, solid content concentration 50% by weight, styrene weight 10% in all monomer components, Butadiene 50
Wt%, acrylonitrile 31 wt%) coating liquid H
An inkjet recording sheet was prepared and evaluated in the same manner as in Example 1 except that the above was used. The evaluation results are shown in Table 1.

[0026]

[Table 1]

As is clear from Table 1, the barrier layer contains
(A) a vinylidene chloride resin or (b) an acrylonitrile-butadiene-styrene copolymer containing a resin having an acrylonitrile component of 15% by weight or more and a butadiene component of 10 to 35% by weight in a monomer weight ratio. In the ink jet recording sheets of Examples 1 to 5, the base material does not swell due to the solvent of the oil-based ink, and the sheets do not wavy after being left alone. In particular, the ink jet recording sheets of Examples 1, 2, 4 and 5 further having a vinylidene chloride resin or the above-mentioned copolymer resin also in the back surface layer are stored even if the back surface of the sheet is overlapped with the printing screen of another sheet. ,
The sheet will not wavy. On the other hand, the sheets of Comparative Examples 1 to 3 in which the barrier layer does not contain the vinylidene chloride resin or the specific acrylonitrile-butadiene-styrene copolymer resin cause waviness in the state of being left alone, and are also left in piles. The waving phenomenon is also caused by doing so. In Comparative Example 1, an acrylic resin coating liquid was applied to the barrier layer, and in Comparative Examples 2 and 3, acrylonitrile-butadiene-styrene copolymer latex was used as the coating liquid. In Example 2, the acrylonitrile component of the copolymer is less than 15% by weight, and in Comparative Example 3, the butadiene component is more than 35% by weight, both of which are specific acrylonitrile-butadiene-styrene copolymers of the present invention. Is different from.

[0028]

INDUSTRIAL APPLICABILITY The ink jet recording sheet for oil-based ink of the present invention has no swelling of the sheet even when an oil-based ink is used, the corrugation phenomenon of the sheet is prevented, and the printing density is excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an inkjet recording sheet of the present invention.

[Explanation of symbols]

1 Ink receiving layer 2 barrier layers 3 base materials 4 Back layer

Claims (5)

[Claims] 1. An inkjet recording sheet having a substrate and at least one ink receiving layer, having at least one barrier layer between the substrate and the ink receiving layer,
The barrier layer is (a) a vinylidene chloride resin or (b) an acrylonitrile-butadiene-styrene copolymer, wherein the acrylonitrile component is 15% by weight or more and the butadiene component is 10 to 35% in a monomer weight ratio.
An ink jet recording sheet for oil-based ink, comprising a resin in an amount of wt%, or (c) a mixture of these resins. 2. A back surface layer is provided on the side opposite to the surface having the ink receiving layer of the base material, and the back surface layer is (a) vinylidene chloride resin or (b) acrylonitrile-butadiene-.
A styrene-based copolymer, which comprises a resin having an acrylonitrile component of 15% by weight or more and a butadiene component of 10 to 35% by weight in a monomer weight ratio, or (c) a mixture of these resins. The inkjet recording sheet for oil-based ink according to claim 1. 3. The inkjet recording sheet for oil-based ink according to claim 1, wherein the base material is polyolefin. 4. The ink jet recording sheet for oil-based ink according to claim 3, wherein the base material is any one selected from polyethylene, polypropylene and copolymers thereof. 5. The binder according to claim 1, wherein the binder of the ink receiving layer is at least one selected from acrylic ester resin, chlorinated polypropylene, and vinyl versatate resin. Inkjet recording sheet for oil-based ink.