JPH11131389A - Coated paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coated paper capable of allowing multicolored gradation design to be readily printed at a high speed in large quantities by using the paper the print on which is described to be difficult. SOLUTION: This coated paper is obtained by using a Japanese paper having 4 mm average fiber length as a base paper, and coating a coating liquid containing polyethylene particles having 4.5 μm volume average particle diameter, and a binder on both sides of the paper to provide a clear coating layer. A multicolored gradation design can be printed on the coated paper by a high- speed offset printing machine at a speed of several thousand to ten thousand sheets per hour.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated paper, and more particularly, to a paper made of paper which has been conventionally difficult to print.
In addition, the present invention relates to coated paper capable of easily and rapidly printing a large number of multicolored pictures with gradation.

[0002]

2. Description of the Related Art Paper is a sheet obtained by entanglement of cellulose fibers taken from a plant as a raw material with each other, and hydrogen bonding hydrophilic groups such as OH groups contained in the cellulose fibers to each other. When this cellulose fiber is long, the entanglement between the fibers is strong, and the number of bonding points between the cellulose fibers is also large, and therefore, despite its thin thickness, it is tough and hard to break, and
It is known that flexible and highly transparent paper can be obtained. And supple and highly transparent paper like this
The entanglement of the fibers and the density of the fiber density can be observed with the naked eye, and thus the entanglement of the fibers and the density of the fiber density observed with the naked eye create a subtle feeling and taste.

However, when printing on such a paper having a long fiber length, the adhesive strength of the printing ink to the printing plate or blanket exceeds the adhesive strength to the paper surface,
For this reason, the printing ink does not adhere to the paper surface, or the entanglement and hydrogen bond between the celluloses are broken, and the paper is peeled off or fluffed. In addition, since the adhesion of the printing ink is not stable, and it is not possible to accurately control where the ink adheres and where it does not adhere, it is difficult to print a pattern with gradation (dark and light), and it was possible to print a gradation image temporarily. However, only a low-quality printed matter having uneven gradation (shading) was obtained.

On the other hand, such a paper having a long fiber length has little or no rigidity required for printing due to its flexibility, and is easily wound around a printing cylinder or a blanket cylinder of a printing press. There was a problem. For this reason, for example, high-speed mass printing of several thousands to 10,000 sheets per hour has been impossible.

On the other hand, there is also known a technique in which a coating layer is applied to paper having a long fiber length, and printing is performed on the coating layer. For example, it is a coating liquid in which a natural resin such as alum or rosin is mixed with glue. There is also known a technique in which a synthetic resin such as polyamide, epoxy resin, polyethylene, or polyvinyl chloride is applied as a coating solution, and printing is performed on the obtained coating layer. However, the paper provided with these coating layers has a smooth surface. Therefore, when a large number of papers coated in this way are stacked, the paper and the paper come into close contact with each other. There is a problem that paper cannot be fed.

[0006] Due to the existence of these various problems, papers having a long fiber length have been demanded for a long time in spite of their unique texture and taste, or excellent characteristics such as toughness and suppleness. However, a multicolor gradation image could not be printed.

At present, printing techniques applied to paper having a long fiber length include, for example, flexographic printing, silk screen printing, woodcut printing and the like. Although not strictly included in the printing technology, as a means for applying a pattern, a printing die is placed on paper, and a dye solution or printing paste is applied from a hole formed in the printing die to obtain a cellulose fiber at an exposed portion. A dyeing method or a printing method for dyeing is applied. In addition, there is also known a method in which an anti-paste paste is applied in a pattern instead of a printing type, and cellulose fibers at a portion exposed from a portion where the anti-paste paste is not applied are dyed or printed. However, in any of these methods, it is difficult to form a pattern with gradation (dark and light) or a multi-color pattern, although the image forming speed is slow and time-consuming.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to easily print a multicolor pattern having a gradation on paper which has been conventionally difficult to print. It is another object of the present invention to provide coated paper capable of high-speed, high-volume printing.

[0009]

That is, the invention according to claim 1 is based on the premise that coated paper is provided with a paper substrate and a transparent coating layer directly applied on the paper substrate.
The transparent coating layer contains polyolefin particles and a binder for fixing the polyolefin particles to the paper substrate, and the site where the polyolefin particles exist protrudes from the peripheral region.

According to the first aspect of the present invention, since a coating layer is applied directly on a paper base material, the adhesive force between the printing ink and the coating layer is adjusted to transfer the printing ink. It is possible to increase.
In addition, the coating layer provides a stiffness necessary for printing, and can prevent winding around a plate cylinder or a blanket cylinder of a printing press.

Further, the coating layer according to claim 1 is
Since the polyolefin particles are contained and the site where the polyolefin particles are projected protrudes from the periphery thereof, even when a plurality of coated papers are stacked, the size of the protruding portion is limited between these papers. Accordingly, a gap is formed, and these papers do not adhere to each other. For this reason, it is possible to apply the present invention to a high-speed printing machine, and moreover, to feed the sheets one by one without fail.

As described above, according to the first aspect of the present invention, the printing machine is designed to have a good adhesion to a printing ink, compatibility with a printing cylinder of a printing machine, compatibility with a paper feeding device of the printing machine, and the like. The compatibility with each part is greatly improved, and as a result, high-speed multicolor printing of, for example, 10,000 sheets per hour or more can be performed, which is compatible with a mass high-speed printing machine as a whole.

Next, the polyolefin particles according to claim 1 may be those which are not affected by the solvent, such as low density polyethylene particles, high density polyethylene particles, medium density polyethylene particles, polypropylene particles, and the like. Polybutene particles, polypentene particles, particles composed of a copolymer thereof, and the like can be used. Further, particles composed of a copolymer obtained by copolymerizing a small amount of a monomer other than the olefin with the olefin monomer may be used without causing any harm. Incidentally, polyethylene particles are preferred.

Further, as the polyolefin particles,
Desirably, the size of at least one of the particles is greater than the thickness of the coating layer. Generally, the thickness of the coating layer is about 1 to 5 μm, and the maximum particle size in the polyolefin particles may reach several times the volume average particle size. If the volume average particle size is 1 μm or more, the largest of these polyolefin particles may be larger than the thickness of the coating layer. Preferably, the volume average particle size is at least 2 μm, more preferably at least 3 μm. The volume average particle size can be measured, for example, by a laser diffraction method, a Coulter counter method, or the like. Since this measurement can be made by measuring the particle size of the polyolefin in the coating liquid, the production design of the coated paper can be simplified.

The invention according to claim 2 has been made based on such a reason. That is, the invention according to claim 2 is based on a paper base and a transparent coating directly applied on the paper base. The transparent coating layer is provided by applying a coating liquid containing polyolefin particles having a volume average particle diameter of 1 μm or more, and a binder for fixing the polyolefin particles to the paper base material. It is characterized by having been done.

Further, it is desirable that the polyolefin particles have a particle size capable of satisfactorily scattering light in the visible region. That is, the binder applied to the coating layer together with the polyolefin particles, generally,
The light absorptivity is low on the long wavelength side (about 700 nm) of light in the visible region (light having a wavelength of about 400 to 700 nm), and increases as the wavelength approaches the short wavelength side (about 400 nm). Therefore, the binder is slightly,
Normally, the color is colored to a complementary color (brown) of the color of light (purple) in nm. Therefore, for example, when using paper having a delicate texture and taste due to the entanglement of fibers and the density of the fiber density, the paper may appear to be colored slightly brown due to the binder. . On the other hand, when the polyolefin particles scatter the visible light well, coloring can be suppressed by the scattered light. As described above, the coloring of the coating layer is suppressed, and furthermore, the gloss of the surface is suppressed by light scattering, so that the high whiteness and the associated texture and taste can be fully utilized. This particle size may be 30 μm or less. Preferably it is 20 μm or less, more preferably 10 μm or less. Incidentally, the average particle size in the coating layer can be measured by an electron microscope.

The invention according to claim 3 has been made based on such technical reasons. That is, the invention according to claim 3 is based on the invention according to claim 1 or 2,
The polyolefin particles have an average particle size of 30 μm or less.

The polyolefin particles preferably occupy 5 to 50% by weight of the coating layer. If the amount is less than 5% by weight, the light scattering performance of the coating layer is insufficient, and the paper may be slightly colored. Preferably, it is at least 10% by weight. On the other hand, if it exceeds 50% by weight, the transfer performance of the ink is inferior, and it becomes difficult to print a beautiful gradation image.

Next, as the binder according to the present invention,
Synthetic resins or semi-synthetic resins that can be dissolved or dispersed in a solvent can be used. For example, rosin-modified phenolic resins, petroleum resins, alkyd resins or modified resins thereof, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate- Copolymer, acrylic resin, polyester resin,
Examples include urethane resins, chlorinated polyolefin resins, chlorinated rubber resins, ethylene-vinyl acetate copolymer resins, polyamide resins, and cellulose resins.

Next, as the paper substrate according to claims 1 to 3, those containing cellulose fibers having an average fiber length of 3 mm or more can be suitably applied, but not limited thereto, and any paper can be applied. For example, paper which has conventionally been difficult to perform beautiful high-speed mass printing can be applied. For example, rough paper, straw paper, recycled paper, kraft paper, and the like.

The paper substrate containing cellulose fibers having an average fiber length of 3 mm or more is made of goose, manila hemp, crocodile, honey, etc., and the beating step is omitted or beaten under relatively mild conditions. Perform the process, to minimize the cutting of cellulose fibers contained in these raw materials,
Japanese paper whose average length is limited to 3 mm or more can be exemplified.

The invention according to claim 4 limits the paper base material to a preferable one for the above reasons. That is, a fourth aspect of the present invention is based on the first to third aspects, wherein the paper base material contains cellulose fibers having an average fiber length of 3 mm or more.

As the paper base material according to the fourth aspect, any of handmade Japanese paper and machine-made Japanese paper can be used. Further, even in the case of Western paper, if the average fiber length is 3 mm or more, the pliability and toughness can be utilized, but Japanese paper is excellent in terms of texture and taste due to the degree of entanglement of cellulose fibers, and preferably It is possible to apply. For the same reason, it is preferable to use a material having high transparency and capable of visually observing the degree of entanglement of cellulose fibers when viewed through an electric or fluorescent lamp. In addition, the paper substrate may be any of a sheet paper and a rolled paper. In the case of web paper, high-speed printing is possible within the range of the performance of the printing press,
Thousands to 1000 per hour, even when using sheet paper
It is possible to perform multicolor gradation printing of four or more colors at zero or more high-speed printing.

Next, the coating liquid according to the present invention is applied to a paper substrate by using a printing method such as an offset printing method (offset printing with water and offset printing without water), a gravure printing method and a silk screen printing method. Can be applied.

When the coating is performed by using the offset printing method, it is preferable to use a rosin-modified phenol resin, a petroleum resin, an alkyd resin or a modified resin thereof as the binder. As the solvent, hydrocarbon solvents such as normal paraffin, isoparaffin, aromatic hydrocarbon, naphthene and α-olefin can be preferably used. In addition, drying oils such as linseed oil, tung oil and soybean oil can be added. In addition, additives such as a dryer, a drying inhibitor, and an ultraviolet absorber can be contained. The mixing ratio is, assuming that the binder is 100 parts by weight, 0 to 400 parts by weight of the drying oil, 0 to 100 parts by weight of the solvent, and 1 to 20 parts by weight of the additive. The polyolefin particles, when the solid content (which remains as a coating layer after coating and drying and is composed of a binder, a drying oil, additives, etc.) is 100 parts by weight,
It is desirable to occupy 5 to 50 parts by weight. Preferably,
It is 10 to 50 parts by weight.

The coating liquid can be applied directly on a paper substrate by an offset printing method using a conventional method. “Direct” means that the composition is applied onto a paper substrate without a printing ink film. If the printing ink film is present, the paper substrate expands and contracts due to the fountain solution when the coating liquid is applied, and therefore, the printing ink film printed on the coating layer and the paper substrate and the coating layer Alignment with the printing ink film becomes difficult.

Next, when applying by gravure printing, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate-copolymer,
It is preferable to use acrylic resins, polyester resins, urethane resins, chlorinated polyolefin resins, chlorinated rubber resins, ethylene-vinyl acetate copolymer resins, polyamide resins, and cellulose resins. As the solvent, toluene, ethyl acetate, isobutyl acetate, methyl ethyl ketone, methyl isobutyl ketone and the like can be preferably used.
In addition, additives can be added. The mixing ratio was 100 parts by weight of the binder and 100 parts by weight of the solvent.
To 400 parts by weight and 0 to 20 parts by weight of additives. In addition,
It is desirable that the polyolefin particles occupy 5 to 50 parts by weight when the solid content is 100 parts by weight. Preferably, it is 10 to 40 parts by weight.

Claims 5 and 6 are based on the above circumstances and specify a method of applying a coating layer. That is, the invention according to claim 5 is based on the invention according to claims 1 to 4, characterized in that the transparent coating layer is provided by offset printing, and according to claim 6, The invention is based on the premise of the invention according to claims 1 to 4, characterized in that the transparent coating layer is provided by gravure printing.

The transparent coating layer can be provided on one side of the paper substrate, but can also be provided on both sides. In this case, multi-color gradation printing can be performed on both surfaces.

The transparent coating layer is desirably formed uniformly on the entire surface of the paper substrate in order to minimize water absorption during the formation of the transparent coating layer and expansion and contraction caused by the water absorption. It is also possible to apply a pattern to a part of the substrate as long as the expansion and contraction of the substrate does not cause any harm. In this case, it is possible to provide a printing ink film on the transparent coating layer. However, even if the printing ink film is not provided, the light transmittance of the portion where the transparent coating layer is present is different from that of the portion where the transparent coating layer is not present. A decorative effect such as a pattern can also be exhibited.

It is also possible to form a thick transparent coating layer on a part of the paper substrate and form a relatively thin transparent coating layer on other parts. Again, in this case,
It exhibits a decorative effect similar to a watermark pattern.

Next, claims 7 to 9 relate to coated paper having a printed layer. That is, the invention according to claim 7 is based on the inventions according to claims 1 to 6, and is characterized in that a printing ink film is provided on the transparent coating layer. The invention according to claim 8 is based on the premise of the invention according to claim 7, characterized in that the printing ink film constitutes a pattern with gradation. The invention according to claim 7, Claims 7 to
8 is based on the premise that the printing ink film comprises a patterned printing ink film arranged and provided so as to form a color pattern of two or more colors.

These printing ink films can be formed by conventionally known offset printing (offset printing with water and offset printing without water), gravure printing, etc., and in particular, several thousand to ten thousand per hour. High-speed mass printing of 1,000 sheets is possible. Also, printing can be performed by an electrophotographic printing method represented by color copying. When applied to an electrophotographic printing method such as color copying, it is possible to easily and easily form a print pattern of various kinds in a small amount on a paper base material such as Japanese paper having an excellent texture and taste.
When the printing of the pattern and the application of the transparent coating layer are performed by the same printing method, the printing of the pattern can be performed by one printing machine following the application of the transparent coating layer.

It is also possible to further apply the transparent coating layer on the printing ink film and to sandwich the printing ink film between the transparent coating layers. In this case,
Since the upper surface of the printing ink film is coated with the transparent coating layer having high hydrophobicity, the resistance to hydrophilic beverages, sweat, etc. is improved, and printed matter having extremely high storability can be obtained.

Next, the coated paper according to the present invention can be applied to any application. However, when the paper base is made of paper having a long average fiber length, its transparency, flexibility, texture, taste, etc. It is desirable to apply the present invention to applications that can take advantage of the characteristics described above.

Such applications include, for example, folding screens,
Examples include bran front paper, wallpaper front paper, and shoji paper. When applied to these uses, it is desirable to exhibit a decorative effect similar to a watermark pattern.
Such a decorative effect can be achieved, for example, by providing a transparent coating layer in a pattern or by partially changing the thickness of the transparent coating layer. Alternatively, the printing ink film may be formed by printing a thin black ink in a pattern.

Further, when used as a paper for a copy of a scroll such as a Japanese painting, a print, a scroll, a religious picture, a mandala picture, a scripture, etc., it has a taste that is hard to distinguish from the real picture.

The present invention may be used as an inventory sheet for gifts to be given at the time of bereavement, a gold seal for congratulations or non-congratulations, invitations and invitations for weddings, greeting cards, Christmas cards, telegrams, and other mounts. Is also possible.

Further, when applied to a lamp shade or a running light used for indoor lighting, it is possible to create a fascinating atmosphere having a multi-color gradation pattern. Moreover, it is also possible to enhance the hygiene and aesthetic properties as indoor ceiling paper, wallpaper and the like.

Further, the present invention can be used for a cover of a magazine or a book or a sheet of a body, a calendar, a poster, a flyer, a catalog, a book cover, and the like.

Further, the present invention can be applied to chiyogami, origami, and the like, and chiyogami and origami having a photographic pattern which has not existed conventionally can be obtained.

In addition, liquid containers such as sake (glass bottles,
It can also be used as a label for plastic bottles). It can also be used as paper for the exterior of a liquid paper container such as a paper pack. In this case, by laminating a plastic film, aluminum foil, or a plastic film having a silicon oxide vapor-deposited film and the like, by making the laminated material such that the paper substrate can be visually observed from the outer surface, Both hygiene and aesthetic properties can be enhanced.

In addition, various types of wrapping paper, such as paper for mizuhiki, paper for dolls, exterior and interior of packaging boxes, individual wrapping paper such as buns, wrapping paper for wrapping products sold at stores such as department stores, and kimonos It can be used as a wrapping paper for wrapping or preserving garments or for storing. Further, the coated paper of the present invention can be sewn and used as clothing such as shirts, blouses and suits.

[0044]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] Using a varnish- modified rosin-modified phenol resin as a binder,
First, varnish A was prepared to have the following composition.
That is, 40% by weight of the rosin-modified phenol resin,
Tung oil 40% by weight, No. 3 solvent (Nippon Petrochemical Co., Ltd.)
Solvent production) 20% by weight was charged into a four flask with a stirring function, and heated to 180 ° C. to dissolve the binder,
Varnish A was used.

Preparation of Transparent Coating Solution Polyethylene particles (4.5 μm in volume average particle size measured by a laser diffraction method) were added to the varnish A, and the varnish A was 88.4.
Parts by weight: 10 parts by weight of particles were mixed and thoroughly dispersed and kneaded with a ball mill. As additives, 0.3% by weight of manganese naphthenate and 0.1% by weight of a cobalt naphthenate dryer.
3% by weight and 1% by weight of a drying inhibitor were mixed to obtain a transparent coating liquid. When the solid content (the component remaining on the paper substrate after printing and drying) in the coating liquid is 100 parts by weight, the content of the polyethylene particles is about 12.1 parts.
Parts by weight.

Echizen Japanese paper (average fiber length: 4 mm, medium thickness mouth, sheet paper) manufactured by hand-making using grooves as a base material for forming a transparent coating layer
It was used. This paper base material had a delicate texture, with the entanglement of the cellulose fibers being visually recognizable, and had high transparency and whiteness. When the electric lamp was seen through the electric lamp, the electric lamp felt dazzling.

A large number of the paper base materials are stacked and stacked, and the stacked body is mounted on a sheet feeding section of a sheet-fed offset printing press.
A transparent coating layer was formed by uniformly applying and drying the entire surface of both sides of the Japanese paper.

An electron micrograph of a cross section of the obtained coating layer was taken and analyzed by a computer. As a result, the coating layer had an average thickness of about 1.1 μm, and the polyethylene particles had a thickness of 4.5 μm or less. Average particle size. In addition, the polyethylene particles protruded from the coating layer to constitute a protruding portion, despite the fact that the polyethylene particles were crushed by the meat of a printing machine and the particle size was reduced.

A large number of the above-mentioned paper base materials provided with a transparent coating layer on both sides of the pattern printing are stacked and stacked, and the stack is supermaster 102
(High-speed offset printing press with eight colors (Headerberg Co., 4 colors + 4 backs) manufactured by Heidelberg) was attached to the paper feed unit. In addition, a photograph of an athlete was adopted as a pattern on the front side, and a multicolored pattern with gradation in four colors of ink, indigo, red, and yellow was printed. Also,
As the back side pattern, a world map is adopted, ink, indigo, red,
We decided to print a multi-color picture without gradation in four yellow colors.
The map symbols and characters of the back side world map were printed with black ink.

Then, the high-speed offset printing machine was operated. At the beginning of the operation, printing was performed at a speed of 3,000 sheets per hour, but the speed was gradually increased, and printing was performed at a maximum speed of 8,000 sheets per hour. Even at this maximum speed, printing could be performed to the end of the stack without any trouble such as a paper feeding error or a paper wrapping around the blanket cylinder.

The printed matter obtained was sampled during printing, and its hue and gradation were confirmed. Not only those printed at a print speed of 3000 sheets per hour, but also those printed at a maximum speed of 8000 sheets per hour have the desired hue and gradation, and full-color high-speed large-scale offset printing can be performed. It could be confirmed.

[Second to Sixth Embodiments] The mixing ratio of varnish A and polyethylene particles was set to varnish A8
5.4 parts by weight: 13 parts by weight of particles (second embodiment),
81.4 parts by weight of varnish A: 17 parts by weight of particles (third embodiment), 78.4 parts by weight of varnish A: 20 parts by weight of particles (fourth embodiment), 68.4 parts by weight of varnish A: 30 parts by weight of particles Parts (fifth embodiment), 60.4 parts by weight of varnish: 38 parts by weight of particles (sixth embodiment), except that high-speed printing was performed in the same manner as in the first embodiment.

When the solid content is 100 parts by weight, the content of the polyethylene particles is 15.7 parts by weight, 20.3 parts by weight, 23.8 parts by weight, 30.8 parts by weight, and 43. 2 parts by weight.

Each of the obtained prints has the desired hue and gradation, and even when the content of polyethylene particles is 10 to 50% by weight of solid content, full-color high-speed mass offset printing is possible. Was confirmed to be possible.

Seventh Embodiment Preparation of Varnish Acrylic polyol having methyl methacrylate and butyl methacrylate as main constituent units, and vinyl chloride
Using a vinyl acetate copolymer resin as a binder, a varnish B was first prepared to have the following composition.

That is, the acrylic polyol 2
2.5% by weight, 2.5% by weight of the vinyl chloride-vinyl acetate copolymer resin, 37.5% by weight of toluene, 17.5% by weight of isobutyl acetate, 15% by weight of ethyl acetate, and 3% by weight of methyl isobutyl ketone were stirred. The mixture was charged into a four-necked flask equipped with a function and heated to dissolve the binder, thereby obtaining Varnish B.

Preparation of Transparent Coating Solution To 100 parts by weight of the varnish B, 5 parts by weight of polyethylene particles (4.5 μm in volume average particle diameter measured by a laser diffraction method) were mixed, and sufficiently dispersed. did. When the solid content (the component remaining on the paper substrate after printing and drying) in this coating liquid is 100 parts by weight, the content of the polyethylene particles is about 16.7 parts by weight.

Echizen Japanese paper (average fiber length: 4 mm, medium-thick mouth, sheet paper) manufactured by hand-making from groats as a base material for forming a transparent coating layer
It was used. This paper base material had a delicate texture, with the entanglement of the cellulose fibers being visually recognizable, and had high transparency and whiteness. When the electric lamp was seen through the electric lamp, the electric lamp felt dazzling.

The above-mentioned transparent coating solution was uniformly applied to the entire surface of one side of the paper substrate by a small gravure proof press and dried. Next, the paper substrate was inverted, and uniformly coated and dried on the opposite surface.

An electron micrograph of a cross section of the obtained coating layer was taken and analyzed by a computer. As a result, the coating layer had an average thickness of about 3 μm, and the polyethylene particles had an average thickness of 4.5 μm or less. Had a particle size. Moreover, the polyethylene particles were broken by the meat of a printing machine or the like, and although the particle size was reduced, a part of the polyethylene particles protruded from the coating layer to form a convex portion.

The transparency, whiteness, and texture of the paper substrate were all the same as before the formation of the transparent coating layer.

A large number of the above-mentioned paper base materials provided with a transparent coating layer on both sides of the pattern printing were stacked and stacked, and the stack was mounted on a sheet feeding section of a sheet-fed gravure printing machine. In addition, the landscape of the beach with clouds and blue sky was adopted as the pattern on the front side, and a multi-color pattern with gradation in four colors of ink, indigo, red, and yellow was printed. As the picture on the back side, the guide map of the above-mentioned beach was printed with a multi-color picture with no gradation in four colors of ink, indigo, red, and yellow. The characters in the guide map on the back side were printed with black ink.

Then, the sheet-fed gravure printing machine was operated. At the beginning of operation, printing was performed at a relatively low speed, but the printing speed was gradually increased and printing was performed at a high speed. Even at this maximum speed, printing could be performed up to the end of the stack without causing troubles such as a paper feeding error or winding of the paper around the gravure plate cylinder.

The obtained printed matter was sampled during printing, and its hue and gradation were confirmed. Not only those printed at low speed but also those printed at the highest speed have the desired hues and gradations, confirming that high-speed full-color high-speed printing is possible.

[Eighth and Ninth Embodiments] Varnish B100
High-speed printing was performed in the same manner as in the seventh embodiment except that the polyethylene particles were changed to 8 parts by weight (the eighth embodiment) and 10 parts by weight (the ninth embodiment) with respect to the weight parts. did.

When the solid content is 100 parts by weight, the content of polyethylene particles is 34.9 parts by weight and 28.6 parts by weight, respectively.

Each of the obtained prints has the desired hue and gradation, the register accuracy of each color is high, and the content of polyethylene particles is 10 to 40% by weight in solid content ratio. Also, it was confirmed that full-color high-speed gravure printing was possible.

[0068]

According to the invention according to claims 1, 5 to 9,
Because the transparent coating layer directly applied on the paper base contains polyolefin particles and a binder for fixing the polyolefin particles to the paper base, the existence site of the polyolefin particles protrudes from the surrounding area. The compatibility with each part of the printing machine, such as the adhesion to the printing ink, the compatibility with the printing cylinder of the printing machine, and the compatibility with the paper feeding device of the printing machine, is significantly improved. Therefore, even if paper, which has conventionally been difficult to print, is used as a base material, it is possible to achieve multicolor high-speed printing, which is compatible with a mass high-speed printing machine as a whole.

According to the present invention, the transparent coating layer is provided by applying a coating liquid containing polyolefin particles having a volume average particle diameter of 1 μm or more, Since the particle size can be measured by measuring the particle size in the coating liquid, there is an effect that the production design of the coated paper can be simplified.

Next, according to the third, fifth to ninth aspects of the present invention, the polyolefin particles have an average particle size of 30 μm or less and scatter visible light well, so that high whiteness and the accompanying This has the effect that the texture and taste can be fully utilized.

Further, according to the invention according to claims 4 to 5 to 9, since the paper base material contains cellulose fibers having an average fiber length of 3 mm or more, the flexibility and the toughness of the paper base are enhanced.
In addition, there is an effect that multicolor high-speed printing becomes possible.

Claims (9)

[Claims] 1. A coated paper comprising a paper substrate and a transparent coating layer directly applied on the paper substrate, wherein the transparent coating layer fixes polyolefin particles and the polyolefin particles to the paper substrate. Characterized in that the polyolefin particles are present in a region where the polyolefin particles protrude from a peripheral region thereof. 2. A coated paper comprising a paper base material and a transparent coating layer directly applied on the paper base material, wherein the transparent coating layer comprises polyolefin particles having a volume average particle diameter of 1 μm or more; and polyolefin particles. Coated with a coating solution containing a binder for fixing the coated paper to the paper base material. 3. The polyolefin particles having an average particle size of 30.
The coated paper according to claim 1, wherein the thickness is not more than μm. 4. The coated paper according to claim 1, wherein said paper substrate contains cellulose fibers having an average fiber length of 3 mm or more. 5. The coated paper according to claim 1, wherein said transparent coating layer is provided by offset printing. 6. The coated paper according to claim 1, wherein said transparent coating layer is provided by gravure printing. 7. The coated paper according to claim 1, further comprising a printing ink film on the transparent coating layer. 8. The coated paper according to claim 7, wherein said printing ink film forms a pattern with gradation. 9. The coated paper according to claim 7, wherein the printing ink film comprises a patterned printing ink film provided so as to constitute two or more color pictures.