JP2000326625A - Powder paint coating sheet, its manufacture and use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder paint coating sheet having a surface layer made of second inorganic fine particles on a resin layer continued with particles of a powder paint composition on a base material through first inorganic fine particles therebetween while having a gap, its manufacture and use or particularly an ink jet recording image receptive sheet capable of forming a clear and accurate image in a high density with a resin layer and a surface layer as an ink receptive layer, and a method for manufacturing it. SOLUTION: The powder paint coating sheet comprises a resin layer 15 continued with powder paint composition particles 12 containing a resin and a coloring agent interposing first inorganic fine particles 13 therebetween while having a gap on a base material 11, and a surface layer 17 adhering and fixing second inorganic fine particles 16 with a binding agent on the layer 15. In such a powder paint coating sheet, the particles 13 in the layer 15 are hydrophilic, and when the particles 16 are hydrophilic, an aqueous ink jet recording image receptive sheet in which the layer 15 and the layer 17 are formed as aqueous ink jet ink receptive layer can be suitably used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder-coated sheet and a method of manufacturing and using the same, and more particularly, to a powder-coated composition sheet having a continuous resin layer with gaps between the particles. Powder coated sheet having a surface layer formed by adhering and fixing inorganic fine particles on the resin tank with a binder, and its production and use, particularly, the resin layer and the surface layer As an ink-receiving layer for aqueous inkjet recording.

[0002]

2. Description of the Related Art Conventionally, various recording systems have been known. In recent years, aqueous ink jet recording systems in which ink is ejected directly from a nozzle toward an image receiving sheet and adhered to thereby perform recording have been widely used. I have.

Conventionally, this aqueous ink-jet recording image-receiving sheet has been prepared by wet-coating a solution containing a resin, an inorganic pigment such as silica, and other additives onto a substrate and drying the solution to form an inorganic pigment in a resin layer. To form a resin layer having a structure having voids, and in addition, using a water-soluble or water-swellable resin as a resin, absorbing the inkjet ink into the voids and the resin to form an image. ing. in this way,
Conventionally, by using a dedicated image receiving sheet, a high-quality recorded image can be obtained for the first time by an inkjet recording method.

However, from the viewpoint of manufacturing, such a dedicated image receiving sheet is formed by wet coating a resin or other additives on a base material to form an ink receiving layer. When removing is required, consideration for the environment is required, furthermore, the resin used is limited as described above, and furthermore, the obtained image-receiving sheet has many manufacturing steps and uses an organic solvent, Expensive.

[0005]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies on the production of an image receiving sheet for ink jet recording by dry coating of a powder coating composition instead of wet coating, and as a result, the powder coating composition The first inorganic fine particles are mixed in a predetermined ratio to the product to form a powder mixture, which is dry-coated on a substrate, melted by heating, and fixed, so that the particles of the powder coating composition are interposed therebetween. The first inorganic fine particles are interposed therebetween, and are continuous while having a gap. Thus, the particles of the powder coating composition are apparently mutually separated and separated by the first inorganic fine particles. It has been found that a resin layer can be formed on a substrate.

[0006] The image-receiving sheet for ink-jet recording having such a resin layer as an ink-receiving layer can be manufactured inexpensively and easily using any resin without any restrictions on the resin to be used. According to such an image-receiving sheet for ink-jet recording, it is possible to form a clear image at a high density with excellent permeability and absorptivity of the ink-jet ink, and thus to obtain a high-quality ink-jet recorded image.

Further, the inventors of the present invention have formed an ink-jet recording which can form a clearer and more accurate image with a higher density by forming a surface layer composed of the second inorganic fine particles on the resin layer. It has been found that an image receiving sheet for use can be obtained, and the present invention has been accomplished.

Accordingly, the present invention provides a method of producing a resin composition comprising the steps of: providing particles of a powder coating composition on a substrate with a first inorganic fine particle interposed therebetween; Powder coated sheet having a surface layer composed of inorganic fine particles and its production and use, in particular, an ink jet capable of forming a clear, accurate image with high density by using the resin layer and the surface layer as ink receiving layers An object of the present invention is to provide a recording image receiving sheet and a method for manufacturing the same.

[0009]

According to the present invention, there is provided a resin composition in which a powder coating composition particle containing a resin and a colorant has a gap with a first inorganic fine particle interposed therebetween. A powder coating sheet is provided which has a layer on a base material and a surface layer formed by bonding and fixing second inorganic fine particles on the resin layer with a binder.

According to a preferred embodiment, the powder coated sheet according to the present invention has an average particle diameter of 0.1 containing a resin and a colorant.
Powder coating composition particles having a mean particle size of
A first inorganic fine particle having a thickness of 1 to 100 μm is interposed and a continuous resin layer having a thickness of 1 to 100 μm is provided on the base material with a gap therebetween, and an average particle diameter of 1 μm is formed on the resin layer.
It has a surface layer formed by bonding and fixing inorganic fine particles of about 50 nm with a binder.

[0011] In the powder coating sheet, when the first inorganic fine particles in the resin layer include a hydrophilic one and the second inorganic fine particles are hydrophilic, the first inorganic fine particles in the resin layer may be in the same state as the resin layer. It can be suitably used as an image receiving sheet for aqueous inkjet recording in which the surface layer is a receiving layer for aqueous inkjet ink.

A method according to the present invention for producing such a powder coating coated sheet comprises mixing a powder coating composition containing a resin and a colorant with first inorganic fine particles to form a powder mixture; A step of dry-coating this on a base material to form a resin layer, and a step of bonding and fixing second inorganic fine particles on the resin layer with a binder to form a surface layer. including.

According to a preferred embodiment, the method according to the present invention for producing such a powder coating coated sheet comprises a powder coating composition particle having an average particle diameter of 0.1 to 30 μm containing a resin and a colorant. And a first inorganic fine particle to form a powder mixture, dry-coating the mixture on a substrate to form a resin layer, and forming a powder mixture having an average particle diameter of 1 to 50 nm on the resin layer. Adhering and fixing the inorganic fine particles of No. 2 with a binder to form a surface layer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A powder coating composition according to the present invention is a powder coating composition having an average particle diameter (average primary particle diameter, hereinafter the same) containing a resin and a colorant of 0.1 to 30 μm. The particles have intervening first inorganic fine particles having an average particle diameter of 1 nm to 1 μm, and have a gap and a continuous thickness of 1 to 1
A resin layer having a thickness of 100 μm is provided on the base material, and a surface layer formed by bonding and fixing second inorganic fine particles having an average particle diameter of 1 to 50 nm with a binder is provided on the resin layer.

In the powder coating sheet according to the present invention, as described later, the first inorganic fine particles in the resin layer include a hydrophilic fine particle and the second inorganic fine particles include a hydrophilic fine particle. In this case, the resin layer and the surface layer can be suitably used as an aqueous ink jet recording image-receiving sheet having an aqueous ink-jet ink receiving layer.

First, the production of such a powder coating sheet according to the present invention will be described. According to a preferred embodiment, the powder coating sheet according to the present invention has a powder coating composition having an average particle diameter of 0.1 to 30 μm, preferably 1 to 25 μm, and an inorganic particle having an average particle diameter of 1 nm to 1 μm. Mixing the fine particles to form a powder mixture, dry-coating the mixture on a base material to form a resin layer, and bonding the second inorganic fine particles on the resin layer with a binder , Fixing and forming a surface layer.

According to the present invention, first, the first inorganic fine particles are adhered to the surfaces of the particles of the powder coating composition by mixing the powder coating composition and the first inorganic fine particles. A powder mixture obtained by coating the surfaces of the particles of the powder coating composition with the first inorganic fine particles is obtained.

In the present invention, the substrate is usually
Paper, synthetic paper, synthetic resin sheet and the like are preferably used.
If necessary, a substrate made of metal is also used. Paper is
The material is not particularly limited as long as it is made of ordinary cellulose fiber, and includes not only plain paper but also high-quality paper and coated paper. Examples of plain paper include ordinary PPC copy paper, paper subjected to calendering to improve the smoothness of the surface of the PPC copy paper, and thermal transfer word processor paper and coated paper that have already been surface-treated. Can be mentioned. Examples of the synthetic resin sheet include sheets made of polyester, polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, polyamide, and the like. Examples of the synthetic paper include those obtained by extruding a mixture of a polyolefin resin or another synthetic resin as a resin component, a required inorganic filler, and the like. In particular, by using paper as the base material, the powder-coated sheet and the ink-jet recording image-receiving sheet according to the present invention can be manufactured at low cost.

The powder coating composition used in the present invention contains a resin. This resin forms a resin layer as a receiving layer of the ink-jet ink on the base material, for example, as described above, together with a role as a binder resin to combine various components of the powder coating composition into powder. In addition, when characters and images are recorded by inkjet ink, a colorant such as a dye or a pigment that forms them is supported to enable recording on an image receiving sheet.

In the present invention, the above-mentioned resin forming the powder coating composition is not particularly limited, and may be a hydrophobic resin, a hydrophilic resin containing a water-absorbing resin or a water-soluble resin, or the like. These mixtures are used. A mixture of these resins may be a mixture of two or more resin particles, for example, a mixture of hydrophobic resin particles and water-absorbent resin particles or hydrophilic resin particles, or, as described later, two or more resin particles. For example, a composite obtained by melt-kneading hydrophobic resin particles with a water-absorbing resin or a water-soluble resin, cooling, pulverizing, and classifying may be used.

The hydrophobic resin means a resin having a deionized water absorption of 0.1 times or less, preferably 0.01 times or less of its own weight. Specific examples thereof include saturated polyester resin and polyamide. Resin, (meth) acrylic resin, polyurethane resin, polyvinyl acetal resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride / vinyl acetate copolymer resin, vinylidene chloride resin, polystyrene resin, styrene / acryl copolymer resin, styrene / butadiene Examples thereof include styrene resins such as copolymer resins, polyethylene resins, ethylene / propylene copolymer resins, ethylene / vinyl acetate copolymer resins, polyolefin resins such as polypropylene, and epoxy resins.

The above-mentioned saturated polyester resin is a polymer obtained by condensation polymerization of a dihydric carboxylic acid and a dihydric alcohol, and the dihydric carboxylic acid is not limited. And aliphatic dibasic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid and hexahydrophthalic anhydride; and aromatic dibasic acids such as phthalic anhydride, phthalic acid, terephthalic acid and isophthalic acid. be able to. If necessary, a tribasic or higher polybasic acid may be used in combination. Examples of such polybasic acids include trimellitic anhydride and pyromellitic anhydride.

The dihydric alcohol is not limited, and examples thereof include ethylene glycol, propylene glycol, butylene glycol, hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, and hydrogenated bisphenol A. be able to. If necessary, a trihydric or higher polyhydric alcohol may be used in combination. Examples of such polyhydric alcohols include glycerin, trimethylolpropane, diglycerin, pentaerythritol, sorbitol and the like.

In the present invention, commercially available products can be suitably used as the saturated polyester resin. Such commercial products include, for example, Byron 103, 20
0, 290, 600 (manufactured by Toyobo Co., Ltd.), KA-10
38C (Arakawa Chemical Co., Ltd.), TP-220, 235
(Manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Diacron ER-1
01, ER-501, FC-172, FC-344, F
C-714 (manufactured by Mitsubishi Rayon Co., Ltd.), Tuffton NE-
382, 1110, 2155 (manufactured by Kao Corporation) and the like.

The styrene-acrylic copolymer resin is a copolymer of styrene and (meth) acrylic acid ester. Specifically, the (meth) acrylic acid ester includes, for example, ethyl acrylate and butyl acrylate. , Methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like.

As such a styrene-acrylic copolymer resin, various commercially available products can be suitably used. Commercially available products include, for example, Hymer UNI-3000, TB
-1800, TBH-1500 (Sanyo Chemical Industry Co., Ltd.)
CPR-100, 600B, 200, 300, X
PA4799, 4800 (manufactured by Mitsui Chemicals, Inc.) and the like.

According to the present invention, the hydrophobic resin used has a softening point of 60 to 150 ° C., preferably 70 to 120 ° C.
Those in the range of ° C are preferred.

The water-absorbing resin is not particularly limited in the polymer material constituting the same, but it is preferably a chemically crosslinked water-absorbing resin, and the amount of deionized water absorbed per unit weight of the resin. Is 100-1000g
/ G is preferable, and especially 300 to 10
Those in the range of 00 g / g are preferred. Examples of such a water-absorbing resin include a crosslinked product of polyacrylic acid partial sodium salt (for example, Aqualic (registered trademark) CA manufactured by Nippon Shokubai Co., Ltd., Sun Fresh ST-500MPS manufactured by Sanyo Chemical Industry Co., Ltd.) and the like. And starch / acrylic acid graft polymer partial sodium salt (for example, Sanfresh ST-500S or 100 manufactured by Sanyo Chemical Industries, Ltd.).

In addition, a crosslinked isobutylene-sodium maleate copolymer, a crosslinked styrene-sodium maleate copolymer, a starch-sodium polyacrylate grafted product, a saponified starch-polyacrylonitrile grafted product, cellulose-polystyrene Examples thereof include a grafted product of sodium acrylate and a vinyl alcohol-sodium (meth) acrylate copolymer. Commercially available products can be obtained for such a chemically crosslinked type water absorbent resin.

Examples of the water-soluble resin include polyvinyl alcohol, polyethylene oxide, polyethylene oxide-polypropylene oxide copolymer,
Examples include hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylpyrrolidone, and the like.

According to the present invention, the hydrophilic resin used has a softening point of 40 to 150 ° C., preferably 50 to 120 ° C.
Those in the range of ° C are preferred.

When the powder coated sheet according to the present invention is used for an image receiving sheet for ink jet recording, the resin in the powder coated composition is not particularly limited as described above. Hydrophobic resins such as polyester resins and styrene-acrylic copolymer resins, and mixtures of these hydrophobic resins with water-soluble resins such as polyvinyl alcohol and polyethylene oxide are preferably used.

In the present invention, the powder coating composition may contain additives such as a coloring agent and a filler, if necessary. The colorant is preferably white, and for example, titanium oxide or silica is preferably used, but is not limited thereto. The colorant gives the substrate the required ground color. The white colorant gives the substrate a white ground color.
The coloring agent is usually 0.5 to 60 in the powder coating composition.
%, Preferably in the range of 5 to 50% by weight. As the filler, for example, calcium carbonate or the like is used.

Further, according to the present invention, the powder coating composition does not cause offset when dry-coated on a substrate and then melted by heating to be fixed on the substrate. Thus, if necessary, an anti-offset agent may be contained. Usually, the melting point of the anti-offset agent is 50.
Various waxes in the range of -150 ° C are preferably used. Specifically, for example, paraffin wax,
Examples thereof include polyolefin waxes such as polyethylene and polypropylene, fatty acid metal salts, fatty acid esters, higher fatty acids, and higher alcohols. Such an offset preventing agent is usually used in a powder coating composition in an amount of 0.1.
To 20% by weight, preferably 0.5 to 10% by weight.

As described above, a powder coating composition containing a colorant, a filler, and other additives together with a resin is prepared by mixing these, and is usually about 100 to 200 ° C., preferably about 1 to 200 ° C.
It is obtained by melt-kneading at a temperature of about 30 to 180 ° C. for several minutes, usually about 3 to 5 minutes, cooling, pulverizing and classifying. The powder coating composition has an average particle size of 0.1.
-30 μm, preferably 1-25 μm, most preferably 5-20 μm.

As described above, the powder coating composition contains a colorant, a filler, and other additives together with the resin. According to the present invention, in the powder coating composition, various resins are used. It may be a composite integrated into the powder coating composition in various structures or forms.

That is, the simplest powder coating composition is one in which the resin components are composed of a single resin (for example, a hydrophobic resin) having the same properties. However, according to the present invention, the resin component in the powder coating composition may be a composite composed of two or more resins having different properties.

For example, a hydrophobic resin and water-absorbent resin particles having an average particle diameter of 1 μm to 20 μm, preferably 5 μm to 15 μm are melt-kneaded, if necessary, with the above-mentioned additives. Since the water-absorbent resin particles have a large average particle size by being pulverized so as to have an average particle size of 5 to 20 μm, the kneaded material is mainly cracked at the interface between the hydrophobic resin and the water-absorbent resin particles. The hydrophobic resin composition particles contained can be obtained as a powder coating composition while partially exposing the water-absorbent resin particles having a large particle size to the surface of the hydrophobic resin particles. Then, as described above, if this is mixed with inorganic fine particles, a powder mixture can be obtained. The ratio of the water-absorbing resin particles is preferably in the range of 5 to 50% by weight, particularly 10 to 30% by weight in the total amount of the hydrophobic resin and the water-absorbing resin particles.

In general, the above-mentioned chemically crosslinked water-absorbent resin does not melt by heating, and therefore has an average particle size of 20%.
If it exceeds μm, it is difficult to uniformly disperse the hydrophobic resin in the hydrophobic resin, even if the hydrophobic resin is melted, kneaded and pulverized, and exists as a particle independent of the hydrophobic resin particles. It will be. However, in the present invention, when the water-absorbent resin and the hydrophobic resin particles are melt-kneaded and pulverized, it is not necessary that all of the used water-absorbent resin particles are dispersed in the hydrophobic resin. May be present as particles independent of the hydrophobic resin composition particles obtained. When the average particle size of the water-absorbent resin particles is smaller than 1 μm,
Since the water-absorbent resin particles are uniformly dispersed in the kneaded material, the kneaded material is less likely to crack at the interface.

According to such a powder coating composition, a portion of the water-absorbent resin particles is exposed on the surface of the hydrophobic resin particles, and thus imparts hydrophilicity to the hydrophobic resin particles. Powder coating sheet having a resin layer composed of a body coating composition, when this is used as an aqueous inkjet recording image receiving sheet, the resin layer, as an ink receiving layer,
It has ink absorbency and color development.

Further, according to the present invention, the hydrophobic resin and the water-soluble resin are melt-kneaded with the above-mentioned additives, if necessary, and the resulting kneaded product has an average particle size of 1 to 30 μm, preferably Since the hydrophilic resin is poorly compatible with the hydrophobic resin by being crushed to have a particle size of 5 to 20 μm, the kneaded material is dispersed as particles in the kneaded material. While breaking at the interface with the hydrophobic resin particles and partially exposing the water-soluble resin particles to the surface of the hydrophobic resin particles, the contained hydrophobic resin composition particles can be obtained as a powder coating composition. . Then, as described above, if this is mixed with inorganic fine particles, a powder mixture can be obtained. The ratio of the water-soluble resin particles is
In the total amount of the hydrophobic resin and the water-soluble resin, 5 to 50
% By weight, especially in the range of 10 to 30% by weight.

According to such a powder coating composition, a part of the water-soluble resin particles is exposed on the surface of the hydrophobic resin particles and thus imparts hydrophilicity to the hydrophobic resin particles. When a powder coated sheet having a resin layer composed of a body coating composition is also used as an image-receiving sheet for aqueous inkjet recording, the resin layer has ink absorbency and color development.

Further, according to the present invention, the hydrophobic resin and the hydrophilic inorganic fine particles having an average particle size of 1 to 5 μm are melt-kneaded and pulverized so as to have an average particle size of 5 to 20 μm. Hydrophobic resin composition particles can be obtained while partially exposing the inorganic fine particles of water to the surface of the hydrophobic resin particles. That is, like this:
After the hydrophobic resin and the hydrophilic inorganic fine particles are melt-kneaded and cooled, when the obtained kneaded material is pulverized so as to have an average particle size of 5 to 20 μm, the average particle size of the hydrophilic inorganic fine particles is relatively large. Since the kneaded material has a diameter, the kneaded material is mainly cracked at the interface between the hydrophobic resin and the inorganic fine particles, and as a result, the inorganic fine particles having such a large particle diameter are partially exposed on the surface of the hydrophobic resin particles. Thus, the obtained hydrophobic resin composition particles can be obtained.

Even with such a powder coating composition, a part of the inorganic fine particles is exposed on the surface of the hydrophobic resin particles, and thus imparts hydrophilicity to the hydrophobic resin particles. When a powder coated sheet having a resin layer composed of a body coating composition is also used as an image-receiving sheet for aqueous inkjet recording, the resin layer has ink absorbency and color development.

The hydrophilic inorganic fine particles kneaded with the hydrophobic resin and dispersed in the kneaded product of the hydrophobic resin have an average particle diameter of 1 μm.
When it is smaller than m, the inorganic fine particles are uniformly dispersed in the kneaded material, and the kneaded material is less likely to crack at the interface. On the other hand, when the average particle diameter of the hydrophilic first inorganic fine particles is larger than 5 μm, the inorganic fine particles are present as independent particles together with the hydrophobic resin composition particles.
As will be described later, this powder coating composition has an average particle size of 1 nm.
A powder mixture obtained by mixing the surface of the hydrophobic resin composition particles with the hydrophilic second inorganic fine particles by mixing with a hydrophilic second inorganic fine particle having a thickness of 1 μm to 2 μm; When dry coating on top, heating and fixing
There is a possibility that good fixing may be hindered.

The ratio of the inorganic fine particles dispersed in the hydrophobic resin is determined based on the total amount of the hydrophobic resin and the inorganic fine particles.
The range is preferably 5 to 50% by weight, particularly preferably 10 to 30% by weight.

As the hydrophilic inorganic fine particles having an average particle diameter in the range of 1 μm to 5 μm to be dispersed in the hydrophobic resin, commercially available products can be suitably used. Examples of such commercially available products include silica such as Carplex manufactured by Shionogi & Co., Ltd., Mizukasil manufactured by Mizusawa Chemical Industry Co., Ltd., and Fine Seal X-37, 40, 70, 80 manufactured by Tokuyama Corporation. ED-I, ED-III, E manufactured by Yonesho Lime Industry Co., Ltd.
DV, calcium carbonate such as Callite KT manufactured by Shiraishi Calcium Co., Ltd., and the like.

Further, according to the present invention, if necessary, two or more kinds selected from the above-mentioned water-absorbent resin, water-soluble resin and hydrophilic inorganic fine particles are mixed with the hydrophobic resin, melt-kneaded, and pulverized. The powder coating composition may be prepared by classification. In particular, a water-soluble resin and hydrophilic inorganic fine particles are blended with a hydrophobic resin, melt-kneaded, pulverized, classified, and the powder coating composition thus obtained is preferred as the powder coating composition used in the present invention. This is an example. In preparing such a powder coating composition, the water-soluble resin and the hydrophilic inorganic fine particles can each be used in a range of 5 to 50% by weight, but preferably 10 to 60% by weight in total. It is good to use in the range.

According to the present invention, such a powder coating composition is mixed with first inorganic fine particles having an average particle diameter in the range of 1 nm to 1 μm to form a powder mixture as described above. By dry coating on the surface of the substrate, heated and melted, and fixed, on the substrate, particles of the powder coating composition between which a substantially continuous film consisting of the inorganic fine particles is interposed. Thus, a continuous resin layer can be formed while having a gap.

In the present invention, the thickness of the resin layer is usually from 1 to 100, although it depends on the use of the powder coating sheet.
It is in the range of μm, preferably in the range of 2 to 80 μm, particularly preferably in the range of 5 to 50 μm. In particular, when the powder coating sheet according to the present invention is used for an image receiving sheet for aqueous inkjet recording, the thickness of the resin tank is preferably within the above range.

According to the present invention, the above-mentioned powder mixture may be dry-coated directly on a substrate, heated and melted and fixed to form a resin layer composed of a powder coating composition. , If necessary, to increase the adhesion between the resin layer and the substrate,
Alternatively, an undercoat made of an appropriate resin may be provided on the base material in order to enhance the smoothness of the base material. Such an undercoat may be provided by dry coating a suitable powder coating, or may be coated with a resin solution.

According to the present invention, the resin layer having a unique structure as described above has an average particle diameter of 0.1 including a resin and a colorant.
1-30 μm powder coating composition particles and average particle size 1 nm
A powder mixture comprising 0.5 to 10% by weight of first inorganic fine particles of 0.5 to 1 μm is dry-coated on a substrate, and the powder coating composition is completely melted to form a continuous coating film. The powder coating composition can be obtained by heating the powder mixture to a temperature lower than the temperature at which the powder coating composition is formed, and incompletely, that is, partially melting the powder coating composition.

Preferably, in the powder mixture comprising the powder coating composition and the first inorganic fine particles, the ratio of the first inorganic fine particles is in the range of 1 to 9% by weight, most preferably 5 to 9% by weight. It is in the range of 8% by weight. However, optimally, it can be experimentally determined according to the average particle diameter of each of the powder coating composition used and the first inorganic fine particles.

When the mixing ratio of the first inorganic fine particles is too small, the first inorganic fine particles are interposed between the powder coating composition particles when the powder mixture is heated and melted and fixed on a substrate. Form a substantially continuous film, interposed between the individual powder coating composition particles, while the powder coating composition particles have a gap, it is not possible to form a continuous resin layer ,
Therefore, for example, when such a powder coating sheet is used as an image receiving sheet for ink jet recording, an image obtained by ink jet recording is not sufficient in density. On the other hand, when the amount is too large, the fixability of the formed resin layer to the substrate is poor, for example, when the substrate is bent,
The resin layer is easily peeled from the substrate. Furthermore, if the proportion of the resinous powder coating composition is relatively small and such a resin layer is used as the ink receiving layer, the formed image density may be insufficient.

Further, the average particle diameter of the first inorganic fine particles is 1
When the particle size is smaller than nm, even if the inorganic fine particles are used in a relatively large amount, the powder coating composition particles cannot form a continuous resin layer while having a gap between them, and on the other hand, the average particle diameter. Is larger than 1 μm, such a first
After dry-coating a powder mixture consisting of inorganic fine particles and a powder coating composition on a substrate, when heated and melted, it is difficult to fix on the substrate, and thus the formed resin The layer peels off from the substrate, causing defects in the resulting powder coated sheet. Therefore, even if such a powder coating sheet is used for an image receiving sheet for ink jet recording, a high quality recorded image cannot be obtained.

When the powder coated sheet according to the present invention is used as an image-receiving sheet for aqueous ink jet recording, the first inorganic fine particles are preferably hydrophilic, and the first inorganic fine particles are preferably hydrophilic. Of these, inorganic fine particles of hydrophilic inorganic oxides and inorganic carbonates are preferable. However, hydrophilic inorganic fine particles and hydrophobic inorganic fine particles may be used in combination, if necessary, depending on the required characteristics of the obtained aqueous inkjet recording image receiving sheet. For example, hydrophilic inorganic fine particles and hydrophobic inorganic fine particles can be used in combination, if necessary, to adjust the absorbability of the aqueous inkjet ink in the ink receiving layer.

As such first inorganic fine particles, commercially available products can be easily obtained. Commercially available hydrophilic inorganic fine particles include, for example, Aerosil (registered trademark) 50, 90 which is anhydrous silica manufactured by Nippon Aerosil Co., Ltd.
G, 130, 200, 200V, 200CF, 200F
AD, 300, 300CF, 380, OX50, TT6
00, MOX80, MOX170, COK84, etc., aluminum oxide C, titanium dioxide P25, etc., Carplex (registered trademark) silica FPS- manufactured by Shionogi & Co., Ltd.
2, FPS-3, FPS-4, FPS-5, FPS-1
01, CS-5, CS-7, BS-304F, BS-3
And inorganic oxide fine particles such as anhydrous silica S13, V15, N20, T30 and T40 manufactured by Clariant Japan. In addition, callite KT, which is calcium carbonate manufactured by Shiroishi Kogyo Co., Ltd., can also be used as the hydrophilic inorganic fine particles.

On the other hand, commercially available hydrophobic inorganic fine particles include, for example, Aerosil R972, R972V, R972CF, anhydrous silica manufactured by Nippon Aerosil Co., Ltd.
R974, R202, R805, R812S, titanium dioxide T805, RX200, RY200, etc., and anhydrous silica H15, H20, H3 manufactured by Clariant Japan
0, H2000, H2000 / 4, H3004, H20
15EP, H2050EP and the like.

As described above, the powder coating composition sheet according to the present invention has a substantially continuous film composed of the first inorganic fine particles interposed between the particles of the powder coating composition, as described above. While having a gap, having a continuous resin layer,
As a result, as described above, not only the first inorganic fine particles are exposed in the form of a film on the surface of the resin layer, but also the particles of the powder coating composition intervene with the first inorganic fine particles. In contact with each other, usually from about 1 nm to 200 n
It has a gap of about m, but in some cases, the powder coating composition particles are not in contact with each other, and a gap may be between them.

The powder coating sheet according to the present invention has a surface layer composed of second inorganic fine particles on such a resin layer on a substrate. That is, the powder coating sheet according to the present invention has a two-layer structure composed of a resin layer and a surface layer on a substrate. This surface layer is formed by bonding and fixing the second inorganic fine particles to each other with a binder, and bonding and fixing a layer made of such inorganic fine particles to the resin layer.

Such a surface layer can be formed by either a dry method or a wet method. First, according to the dry method, a mixture of the second inorganic fine particles and the powder of the resin used for forming the resin layer as the binder is dry-coated on the resin layer, and heated under pressure to form the binder. By melting the binder, the second inorganic fine particles can be bonded and fixed on the resin layer while being mutually bonded by the binder. According to the present invention, the binder is used in an amount of usually 1 to 200 parts by weight, preferably 5 to 100 parts by weight of the second inorganic fine particles.
It is used in the range of １００100 parts by weight.

In the dry method, the resin used as the binder is a resin used for forming the resin layer, that is, a hydrophilic resin including a water-absorbing resin or a water-soluble resin, in addition to a hydrophobic resin. It is a mixture, and preferably the same resin as the resin forming the resin layer is used, but it is not necessary to be the same. However, the resin used as the binder preferably has an average particle diameter of 10 μm or less, and preferably has a softening temperature in the range of 40 to 100 ° C.

In the case of the dry method, a powder mixture comprising the powder coating composition and the first inorganic fine particles is dry-coated on a substrate, which is heated and melted to form a resin layer on the substrate. After being fixed as above, the second inorganic fine particles may be bonded and fixed on the resin layer with a binder to form a surface layer. A powder mixture comprising the first inorganic fine particles is dry-coated, and then a mixture of the second inorganic fine particles and a resin powder as a binder is coated on the coating layer of such a powder mixture by a dry coating method. After coating, the coating layer of the powder mixture and the layer formed of the mixture of the second inorganic fine particles and the resin powder thereon are heated under pressure to fix the resin layer on the base material. At the same time, a second inorganic fine particle may be bonded and fixed on the resin layer with a binder to form a surface layer.

Next, in the case of the wet method, the second inorganic fine particles are dispersed in an appropriate medium, preferably an aqueous medium such as water, and a binder, preferably a water-soluble resin is added thereto. Is dissolved to prepare a coating liquid, which is coated on a resin layer, and then dried to form a surface layer made of the second inorganic fine particles on the resin layer.

FIG. 1 schematically shows a cross section of a preferred embodiment of such a powder coating sheet according to the present invention. On the substrate 11, the individual powder coating composition particles 12 form a film 14 between which the first inorganic fine particles 13 are substantially connected.
The resin layer 15 having a gap is formed while interposing. On such a resin layer 15, a surface layer 17 is further formed by bonding and bonding the second inorganic fine particles 16 to each other with a binder and bonding and fixing the second inorganic fine particles 16 on the resin layer. .

The powder coating sheet thus obtained depends on its purpose and application, but the surface layer usually has a thickness of 10 nm to 3 μm, preferably 20 nm to 3 μm.
It is preferably in the range of 1 μm, and particularly in the range described above when the powder coating sheet according to the present invention is used as an image receiving sheet for ink jet recording.

According to the present invention, as described above, the resin layer contains hydrophilic inorganic fine particles as the first inorganic fine particles.
A powder coating sheet in which the second inorganic fine particles are hydrophilic can be suitably used as an aqueous ink jet recording image-receiving sheet.

That is, the image-receiving sheet for ink-jet recording according to a particularly preferred embodiment of the present invention comprises a powder coating composition particle having an average particle diameter of 0.1 to 30 μm containing a resin and a colorant, and having an average particle diameter of 1 nm to 1 nm. With a first inorganic fine particle containing hydrophilic inorganic fine particles of 1 μm interposed therebetween, while having a gap, a continuous resin layer having a thickness of 1 to 100 μm is provided on the base material, and an average is formed on the resin layer. Particle size 1
It has a surface layer that can be adhered and fixed using 50 nm hydrophilic second inorganic fine particles as a binder.

The average particle diameter of the second inorganic fine particles is 50 nm.
When larger than, when inkjet recording is performed on an image receiving sheet having such a layer of inorganic fine particles on the surface, the obtained image may lack accuracy, and may be used for inkjet recording to give a high quality recorded image. In some cases, the sheet cannot be used as an image receiving sheet. The second inorganic fine particles are
Although the average particle diameter may be smaller than 1 nm, it is sufficient to use one having an average particle diameter of 1 nm or more from the viewpoint of availability.

In the present invention, in order to dry-coat a powder coating composition containing inorganic fine particles on a substrate and dry-coat second inorganic fine particles on a resin layer, for example, Electrostatic coating such as electrospray method and electrostatic immersion method, spray coating method, spray coating method, dispersion method, powder coating such as powder melting and laminating method, dusting method, cascade method, electrophotographic method such as magnetic brush developing method And so on.

Among these dry coatings, in the present invention, for example, an electrostatic spray method can be preferably used. This electrostatic spraying method is a kind of powder coating, and specifically, a mixture of a fine powder coating composition and inorganic fine particles (hereinafter referred to as a powder mixture) at the tip of a spray gun is air. And a negative high voltage (for example,
-50 to -90 kV) to apply a negative charge to the powder mixture and, along with a grounded electrode to the back surface of the substrate,
Thus, the negatively charged powder mixture is carried to the substrate and electrostatically deposited by the electric field present between the spray gun and the grounded electrode.

FIG. 2 shows a preferred embodiment of the method for producing a powder-coated sheet according to the present invention using such an electrostatic spraying method. That is, the continuous long base material (for example, plain paper) 22 rewound from the roll 21 is
3 into a booth 24, where the powder mixture is dry-coated by a first spray gun 28 by electrostatic spraying, as will be described later, and then likewise in a second booth ( (Not shown), and the mixture of the second inorganic fine particles and the binder is dry-coated by the second spray gun 31. The sheet thus obtained is then guided to a fixing roll 25 where it is heated under pressure to melt the powder coating composition and to form a resin layer having the special structure as described above. And a powder coating sheet 30 according to the present invention having a surface layer composed of the second inorganic fine particles adhered and fixed thereon with a binder. The powder coating sheet is then wound on a roll or cut as appropriate.

The transport belt 23 has a grounded (ie, positive) electrode 2 on the back side along the substrate transported by the transport belt 23.
6. The powder mixture is conveyed from the storage tank 27 to the spray gun 28 by compressed air, while a negative high voltage is applied by a DC power supply 29 to a needle electrode (not shown) incorporated at the tip of the spray gun. The powder mixture is negatively charged. Thus, the powder mixture is carried to and adhered to the substrate by the electric field present between the spray gun and the electrodes along the substrate on the conveyor belt. Dry coating of the second inorganic fine particles is performed in the same manner.

[0074]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited by these examples.

Example 1 (Production of an image receiving sheet for ink jet recording)
65 parts by weight of an acrylic copolymer resin (Hymer UNI-3000 manufactured by Sanyo Chemical Industry Co., Ltd.) and 30 parts by weight of a white pigment (hydrophilic silica P-78A manufactured by Mizusawa Chemical Industry Co., Ltd.) are mixed in a biaxial melt kneader. At 150 to 160 ° C. for 4 minutes. After cooling, the obtained kneaded product was pulverized and classified to obtain a white powder coating composition having an average particle size of 11.0 μm.
5 parts by weight of hydrophilic anhydrous silica (Aerosil 200, manufactured by Nippon Aerosil Co., Ltd., average particle diameter: 12 nm) is mixed with 95 parts by weight of the white powder coating composition, and dry-coated by electrostatic spraying. The mixture was a white powder mixture (anhydrous silica 5% by weight).

After the white powder mixture was applied to the entire surface of a commercially available plain paper using a commercially available electrostatic spray device,
The resin layer was heated, melted and fixed to form a resin layer having a thickness of 20 μm.

Next, 70 parts by weight of hydrophilic silica (Aerosil 50 manufactured by Nippon Aerosil Co., Ltd., average particle size 30 nm) and a water-soluble resin (polyethylene oxide-polypropylene oxide copolymer CP-20 manufactured by Sumitomo Seika Co., Ltd.)
00L) and 30 parts by weight. The resulting powder mixture is deposited on the resin layer using an electrostatic spray device, and then heated under pressure to bind the hydrophilic silica to each other in a layered manner with a resin and to form the hydrophilic silica. Was adhered onto the resin layer to form a surface layer having a thickness of 10 μm. Thus, an image receiving sheet for ink jet recording was obtained.

(Inkjet Recording) Using a commercially available inkjet printer (Epson PM-750C), inkjet recording was carried out on the above-mentioned image receiving sheet for inkjet recording, and the ink absorbency and color development were examined. Further, after the ink jet recording was performed, the image receiving sheet was bent to check whether the surface layer was cracked and peeled off, and the fixability of the surface layer was evaluated. In addition, the ink absorbency is described as `` good '' when the ink is not attached to the fingertip by touching the image with the fingertip immediately after inkjet recording the color chart specified by the Japan Standards Association on recording paper, and the ink is partially The case where it adhered to the fingertip was defined as “bad”. The color development of the ink was measured using a Macbeth densitometer (model number RD-914) at the darkest part. Table 1 shows the results.

Comparative Example 1 After a resin layer was formed in the same manner as in Example 1, hydrophilic silica (Aerosil 5 manufactured by Nippon Aerosil Co., Ltd.) was applied to the surface of the resin layer.
0, average particle diameter of only 30 nm) using an electrostatic spraying device, and then heating the resin to compress the hydrophilic silica onto the resin layer to form a layer having a thickness of 5 μm.
Was formed, and thus an image receiving sheet for ink jet recording was obtained.

With respect to this image receiving sheet, in the same manner as in Example 1, the fixing property of the surface layer, the ink absorbing property and the color developing property were examined. Table 1 shows the results.

Example 2 Water-soluble polyvinyl alcohol (PVA- manufactured by Kuraray Co., Ltd.)
117) 20 parts by weight and 30 parts by weight of hydrophilic silica (Aerosil 50 manufactured by Nippon Aerosil Co., Ltd., average particle diameter: 30 nm) were added to 50 parts by weight of water and mixed to prepare an aqueous coating liquid.

After forming a resin layer in the same manner as in Example 1, the above coating solution was applied to the surface, heated and dried to fix the hydrophilic silica in a layer with a resin.
By bonding a layer made of this hydrophilic silica on the resin layer,
A surface layer having a thickness of 10 μm was formed, and thus an image receiving sheet for inkjet recording was obtained.

With respect to this image receiving sheet, in the same manner as in Example 1, the fixing property of the surface layer, the ink absorbing property and the color developing property were examined. Table 1 shows the results.

Comparative Example 2 Styrene / acrylic copolymer resin (C manufactured by Mitsui Chemicals, Inc.)
PR-200) 20 parts by weight and hydrophilic silica (Aerosil 50 manufactured by Nippon Aerosil Co., Ltd., average particle diameter 30 nm) 3
0 parts by weight was added to 50 parts by weight of toluene and mixed to prepare an oily coating solution.

After forming a resin layer in the same manner as in Example 1, the above-mentioned coating solution was applied to the surface thereof, heated and dried to fix the hydrophilic silica in a layer with a resin.
By bonding a layer made of this hydrophilic silica on the resin layer,
A surface layer having a thickness of 10 μm was formed, and thus an image receiving sheet for inkjet recording was obtained.

With respect to this image receiving sheet, the fixing property of the surface layer, the ink absorbing property and the color developing property were examined in the same manner as in Example 1. Table 1 shows the results.

[0087]

[Table 1]

[0088]

According to the powder coating composition sheet of the present invention, the powder coating composition particles containing the resin and the colorant are connected to each other with a gap therebetween, with the first inorganic fine particles interposed therebetween. A resin layer is provided on the base material, and the resin layer has a surface layer formed by bonding and fixing the second inorganic fine particles with a binder, and preferably includes a resin and a colorant. The powder coating composition particles having an average particle diameter of 0.1 to 30 μm have a first inorganic fine particle having an average particle diameter of 1 nm to 1 μm interposed therebetween, and have a thickness of 1 to 100 continuous with a gap.
A resin layer having a thickness of μm is provided on a substrate, and a surface layer formed by bonding and fixing second inorganic fine particles having an average particle diameter of 1 to 50 nm with a binder is provided on the resin layer.

In particular, according to the present invention, the resin coating contains hydrophilic first inorganic fine particles and the second inorganic fine particles are hydrophilic. It can be suitably used as an image receiving sheet.

That is, if the aqueous ink-jet ink adheres to such an image-receiving sheet for aqueous ink-jet recording, the dyes and pigments in the ink are removed from the surface of the hydrophilic second inorganic fine particles constituting the surface layer of the image-receiving sheet. Since it is quickly absorbed and captured by the layer, a high-density image can be formed. Moreover, under the surface layer made of the second inorganic fine particles, the powder coating composition particles have a gap therebetween with a substantially continuous film made of the first inorganic fine particles interposed therebetween. Since the resin layer is formed continuously, the moisture in the ink-jet ink passes through the surface layer made of the second inorganic fine particles, and quickly moves along the film made of the inorganic fine particles between the powder coating composition particles. Since it is adsorbed, trapped and stays in the receiving layer, it does not reach the substrate.

Therefore, according to the image receiving sheet for ink jet recording according to the present invention, even when the base material is paper, the base material does not get wet, and on the other hand, when the base material is a synthetic resin film. Is also absorbed and captured by the first inorganic fine particles, so that the image is not blurred. Further, even when bent, the surface layer does not crack or peel off from the resin layer.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a cross section of a preferred embodiment of a powder coating sheet according to the present invention.

FIG. 2 shows an example of an apparatus configuration for manufacturing a powder coating sheet according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Base material, 12 ... Powder coating composition particles, 13 ... First inorganic fine particles, 14 ... Film 1, 15 ... Resin layer, 16 ... Second inorganic fine particles, 17 ... Surface layer, 21 ... Roll, 22 ... Long base material, 23 ... Conveyer belt, 24 ... Booth, 25 ... Fixing roll, 26 ... Electrode, 27 ... Storage tank, 28 ... First spray gun, 29 ... DC power supply, 30 ... Powder coating Sheet, 31 ... second spray gun.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 7/12 C09D 7/12 Z 201/00 201/00 F-term (Reference) 2H086 BA15 BA32 BA33 BA45 4D075 AA01 AA52 AE03 CA35 DA04 DB18 DC18 EA02 EA17 EA19 EC02 EC53 EC54 4F100 AA00B AA00H AA08A AA08B AA08H AA19A AA19B AA19H AA20A AA20B AA20H AA21A AA21B AA21H AK01A AK21B AS00B AT00C BA03 BA07 BA10B CA13A CC00 DE01A DE01B DE01H DG10C EH611 EH612 EJ192 EJ421 EJ422 EJ861 GB90 JA20A JA20B JD14 YY00A YY00B 4J038 BA091 CB011 CB081 CC021 CD021 CD081 CE021 CE061 CF021 CG111 CG141 CK031 CP011 DB001 DD001 DF021 DG001 DH001 HA216 HA286 HA446 KA08 KA20 MA02 MA14 NA01 NA27 PA02 PC10 PC10 PC08

Claims (14)

[Claims] A powder coating composition particle containing a resin and a colorant has a first inorganic fine particle interposed therebetween, and has a continuous resin layer on a base material while having a gap. A powder paint coated sheet having a surface layer formed by bonding and fixing second inorganic fine particles with a binder on a resin layer. 2. An average particle size of 0.1 to 30 containing a resin and a colorant.
μm powder coating composition particles have an average particle size of 1 nm
A 1-μm-thick first inorganic fine particle is interposed, a resin layer having a thickness of 1 to 100 μm is formed on a substrate, and has an average particle diameter of 1 to 50 μm.
2. The powder coating sheet according to claim 1, further comprising a surface layer formed by bonding and fixing the second inorganic fine particles of nm with a binder. 3. 3. The powder coating composition according to claim 1, wherein the first inorganic fine particles are in the range of 0.5 to 10% by weight based on the total amount of the powder coating composition and the first inorganic fine particles. Coated sheet. 4. The method according to claim 1, wherein the first inorganic fine particles are hydrophilic anhydrous silica,
The powder-coated sheet according to any one of claims 1 to 3, comprising aluminum oxide, titanium dioxide, or calcium carbonate. 5. The method according to claim 1, wherein the second inorganic fine particles are hydrophilic anhydrous silica,
The powder-coated sheet according to claim 1, which is aluminum oxide, titanium dioxide, or calcium carbonate. 6. An image-receiving sheet for aqueous ink jet recording according to claim 1, wherein the resin layer and the surface layer are ink receiving layers. 7. A powder coating composition comprising a resin and a colorant, and a first coating composition.
A powder mixture by mixing with inorganic fine particles of the above, dry-coating the mixture on a base material to form a resin layer, and second inorganic fine particles on the resin layer with a binder Adhering and fixing to form a surface layer. 8. An average particle size of 0.1 to 30 containing a resin and a colorant.
mixing the powder coating composition particles having a particle diameter of 1 μm to form a powder mixture, dry-coating the mixture on a substrate to form a resin layer, and forming an average particle diameter of 1 to 50 nm on the resin layer. Second
Bonding the inorganic fine particles with a binder to form a surface layer to form a surface layer. 9. The method according to claim 7, wherein a mixture comprising the second inorganic fine particles and a resin powder as a binder is dry-coated on the resin layer and heated to form a second mixture. A method for producing a powder coating-coated sheet that forms a surface layer by bonding and fixing inorganic fine particles with a binder. 10. The method according to claim 7, wherein
A coating liquid containing the second inorganic fine particles and a resin as a binder is wet-coated on the resin layer, dried, and the second inorganic fine particles are bonded and fixed with the binder, and the surface is fixed. A method for producing a powder coating sheet for forming a layer. 11. The amount of the first inorganic fine particles is 0.5 to 10% by weight based on the total amount of the powder coating composition and the first inorganic fine particles.
The method for producing a powder-coated sheet according to claim 7 or 8, wherein 12. The method according to claim 7, wherein the first inorganic fine particles include hydrophilic anhydrous silica, aluminum oxide, titanium dioxide or calcium carbonate. 13. The method according to claim 7, wherein the second inorganic fine particles are hydrophilic anhydrous silica, aluminum oxide, titanium dioxide or calcium carbonate. 14. The method according to claim 7, wherein the resin layer and the surface layer serve as an ink receiving layer.