JP2000256991A - Waterproof printing paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide waterproof printing paper having high waterproof, not causing blocking, excellent in winding operability and printability, enabling printed surface to have an excellent finish and capable of being disintegrated. SOLUTION: This waterproof printing paper is produced by coating one surface or both ones of base paper with a coating fluid prepared by mixing core-shell-structured acrylic resin emulsion, inorganic pigment and polyolefin- based fine particles. The coating fluid preferably contains 6-75 pts.wt. total solid content of the inorganic pigment and polyolefin-based fine particles and 3-72 pts.wt. solid content of the inorganic pigment respectively based on 100 pts.wt. solid content of the core-shell-structured acrylic resin emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof paper for printing which has high water resistance and is capable of offset printing. More specifically, it is a waterproof paper for printing that can be used for outdoor posters, home delivery slips, map paper, etc.It has no blocking, good winder workability, good print workability, excellent printed surface quality, and can be disintegrated The present invention relates to a waterproof paper for printing.

[0002]

2. Description of the Related Art Hitherto, a water-resistant sheet having high water resistance and printability has been developed and used for outdoor posters, sticking slips of home delivery slips, label paper, and the like.

[0003] Such a water-resistant sheet is made of a synthetic resin which is essentially unaffected by rainwater or the like, and is formed into a sheet by coating it with a pigment or the like. A synthetic paper having both water resistance and printability has been proposed by laminating paper and a synthetic resin film and providing a printing layer mainly composed of an inorganic filler or the like on the synthetic resin film surface. The former specific example is disclosed in JP-A-3-234900, and the latter specific example is described in JP-A-2-33399.

[0004] Certainly, the above-mentioned water-resistant sheet or synthetic paper has a high degree of water resistance because of using a synthetic resin film material. In addition, due to the provision of a printing layer, it also has printability that is difficult to obtain with a synthetic resin film.

[0005] However, the water-resistant sheet as described above is more expensive than paper and has no biodegradability unlike paper. Therefore, when these are discarded, they remain forever as they are, As a waste, it results in harm to the natural environment. Further, when such a water-resistant sheet or synthetic paper is incinerated, the calorific value is larger than that of paper, and depending on the components, it may cause damage to the incinerator or generate toxic gas. Furthermore, the water-resistant sheet as described above is small in conductivity and easily generates static electricity. For this reason, a paper feeding trouble such as a heavy running easily occurs in a printing operation or a processing operation.

On the other hand, in the above-mentioned synthetic paper, the used synthetic paper cannot be reused as waste paper due to the presence of the synthetic resin film, and waste paper, forest protection, effective use of resources, etc. Not desirable from a standpoint. In addition, paper and synthetic resin film have a large difference in expansion and contraction characteristics, especially due to temperature changes and humidity changes. In the processing operation, a trouble is likely to occur in a paper feeding unit or the like.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above background, and has been studied in order to solve the above problems. It is an object of the present invention to have high water resistance, no blocking, and a winder. An object of the present invention is to provide a disintegratable printing water-resistant paper which has good workability and printing workability, can obtain excellent printed surface quality, and can be disintegrated.

[0008]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have come to invent a waterproof paper for printing as described below.

That is, the waterproof paper for printing of the present invention is obtained by applying a coating liquid comprising an acrylic resin emulsion having a core / shell structure, an inorganic pigment, and polyolefin fine particles to one or both sides of a base paper. It is a feature.

In the present invention, the total of the solid content of the inorganic pigment and the polyolefin-based fine particles is preferably 6 to 75 parts by weight per 100 parts by weight of the solid content of the acrylic resin emulsion having a core / shell structure.

In the present invention, the solid content of the inorganic pigment is preferably 3 to 72 parts by weight per 100 parts by weight of the solid content of the acrylic resin emulsion having a core / shell structure.

Furthermore, in the present invention, it is preferable to apply a coating liquid comprising an acrylic resin emulsion having a core / shell structure, an inorganic pigment and polyolefin fine particles in a solid content of 3 to 15 g / m ² per one surface. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The waterproof paper for printing of the present invention will be described in detail below.

As a method for imparting high water resistance to paper, a method of applying a synthetic resin emulsion to cover the paper surface has been used. However, there is a problem of blocking, and in order to stably supply the paper to the market. In general, a type in which a wax component is contained in a synthetic resin emulsion is used.

However, the waterproof paper for printing which the present inventors aim for must also have printability, and cannot be used with a synthetic resin emulsion containing a wax component because it repels ink. Further, in order to have printability, the resin component itself must have ink acceptability.

As a result of intensive studies, the present inventors have found that a soft component having a low glass transition point in the core portion and excellent in water resistance, flexibility and film formation, and a high glass transition point and a high film hardness in the shell portion. By coating an acrylic resin emulsion having a core / shell structure composed of a hard component, high water resistance, relatively low occurrence of blocking, and relatively good printing water resistance for printing. I got paper.

However, the printed surface quality after printing is sufficient for very simple ruled lines and patterns composed of solid portions, which are often seen in printed forms.
For delicate designs such as posters, this water-resistant paper for printing is still insufficient and needs to be improved. Regarding the printing workability, there is no particular problem in the winding work as in the form printing, but in the work by the sheet-fed printing machine, the chargeability is increased by the resin film,
There was a problem that the paper ran twice during printing due to static electricity. Furthermore, on the operation side, when winding the paper, wrap it in a grooved roll so that the paper flows outward so that the paper does not wrinkle, and roll it up.However, when the paper is covered with a resin film, a sticky feeling occurs on the surface Slippage was worsened, and a problem occurred that wrinkles occurred during winding during coating and winding during winding.
In addition, it has been found that blocking occurs when the winding of the waterproof paper for printing is stored or transported for a long period of time under high temperature and high humidity conditions.

Further investigations have attempted to solve the above problem by mixing an inorganic pigment with an acrylic resin emulsion having a core / shell structure. Inorganic pigments are generally used as a main component in the coating layer composition of coated paper in order to improve ink receptivity. In addition, since the inorganic pigment is a mineral component, the conductivity is enhanced, and generation of static electricity can be prevented. Further, it is considered that the addition of the inorganic pigment eliminates the stickiness of the acrylic resin emulsion film and suppresses the generation of wrinkles and blocking during coating or winding.

As a result, the problems of improved printed surface quality and heavy running in the printing operation were solved by the addition of the inorganic pigment. However, it has been found that a large amount of inorganic pigment must be added in order to solve the problem of wrinkling during coating or winder, which significantly reduces water resistance. In addition, since the inorganic pigment itself is relatively easily absorbed by moisture, the problem that blocking occurs under high temperature and high humidity conditions has not been solved. From the above, it has been found that it is very difficult to solve the problem of the acrylic resin emulsion having a core / shell structure only by adding an inorganic pigment.

Therefore, the present inventors have conducted further intensive studies and attempted to solve the above problem by adding polyolefin-based fine particles to a coating agent obtained by mixing an inorganic pigment in an acrylic resin emulsion having a core / shell structure. The polyolefin-based fine particles used here are those used as a lubricant or an anti-blocking agent. That is, an attempt was made to solve the problem of printability of an acrylic resin emulsion having a core / shell structure with an inorganic pigment, and to solve the problem of wrinkles and blocking that occur during coating and winding with a polyolefin resin dispersion. It is. As a result, all of the above problems were solved, and the waterproof paper for printing of the present invention could be obtained.

As the base paper used in the present invention,
Although not particularly limited, NBKP, LBKP,
Wood pulp such as NBSP, LBSP, GP, and TMP, non-wood pulp such as kenaf, bagasse, Manila hemp, and cotton, or paper made from used paper pulp is preferable. In use, these pulp may be used alone or mixed at an arbitrary ratio. Further, such a paper was coated with a coating agent containing an inorganic pigment as a main component,
So-called coated paper is also suitable as a substrate. In addition, as a raw material of the used paper pulp referred to in the present invention, the white paper and the white paper shown in the used paper standard quality standard table of the used paper recycling promotion center.
Ruled white, cream white, card, special white, medium white, imitation, fair white,
Examples include Kent, white art, extra high quality, separate high quality, newspapers and magazines. Further specific examples include non-coated computer recording paper that is information-related recording paper, printer recording paper such as thermal paper and pressure-sensitive paper, and OA waste paper such as PPC recording paper, art paper, coated paper, lightly coated paper, Coated paper such as matte paper, or high-quality paper, high-quality color, notebooks, stationery,
Used paper such as wrapping paper, fancy paper, medium paper, newsprint, paper change, super wrapping paper, imitation paper, pure white roll paper, uncoated paper such as milk carton, and waste paper such as paperboard, chemical pulp paper, and high yield. Pulp-containing paper or the like is used, but is not particularly limited regardless of printing, copying, printing, or non-printing.

The acrylic resin emulsion used in the present invention has a high level of water resistance and relatively good blocking resistance, and has a low glass transition point in the core portion, and has excellent water resistance, flexibility and film forming properties. It is an acrylic resin emulsion having a core / shell structure composed of an excellent soft component and a hard component having a high glass transition point and a high film hardness in a shell portion. The components of the acrylic resin emulsion are not limited to the following, but in addition to acrylic acid, γ-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, styrene-acrylic , Acrylamide,
Acrylonitrile and the like are used.

Examples of the inorganic pigment used in the present invention include natural minerals such as coral stone, zeolite, ceramics, calcined bone powder, silica, talc, kaolin, calcium carbonate, titanium oxide, Otani stone, activated carbon, activated alumina, sepiolite and the like. Is preferred. In use, one kind of these inorganic pigments or a mixture of two or more kinds can be used.

The polyolefin-based fine particles used in the present invention are usually used as a lubricant and an anti-blocking agent. The types of raw materials include thermoplastic elastomers, low-density polyolefins, ionomers, vinyl acetate-based copolymerized polyolefins, And low molecular weight polyolefins.

In the present invention, an acrylic resin emulsion having a core / shell structure is preferably used as a water-resistant agent used in a coating liquid applied on a base paper. When a resin emulsion other than an acrylic resin emulsion and an acrylic resin emulsion without a core / shell structure are used, water resistance, blocking, and printing suitability (printed surface quality, printing workability)
And the desired waterproof paper for printing cannot be obtained.

In the present invention, the coating liquid to be coated on the base paper is prepared by mixing a solid content of an inorganic pigment and polyolefin fine particles with respect to 100 parts of a solid content of an acrylic resin emulsion having a core / shell structure. Is preferably 6 to 75 parts. If the total content of the solid content of the inorganic pigment and the polyolefin-based fine particles is less than 6 parts with respect to the solid content of the acrylic resin emulsion having a core / shell structure, high water resistance can be obtained. In some cases, wrinkles occur during winding, blocking occurs, and the desired printability cannot be obtained. When the total solid content of the inorganic pigment and the polyolefin-based fine particles exceeds 75 parts with respect to the solid content of the acrylic resin emulsion having a core / shell structure, the emulsion film is formed by the inorganic pigment and the polyolefin-based fine particles. Formation is significantly inhibited, and sufficient water resistance cannot be obtained.

In the present invention, the inorganic pigment used in the coating liquid applied on the base paper is 3 parts as solid based on 100 parts of the solid of an acrylic resin emulsion having a core / shell structure. The compounding ratio is preferably up to 72 parts. If the solid content of the inorganic pigment is less than 3 parts with respect to 100 parts of the solid content of the acrylic resin emulsion having a core / shell structure, not only the printed surface quality is not good, but also the problem of heavy running due to static electricity. Occurs and the desired printability cannot be obtained. Further, with respect to the solid content of the acrylic resin emulsion having a core / shell structure,
If the solids content of the inorganic pigment exceeds 72 parts, formation of a film of the emulsion is significantly inhibited by the inorganic pigment, and sufficient water resistance cannot be obtained.

Further, in the present invention, a coating liquid comprising an acrylic resin emulsion having a core / shell structure, an inorganic pigment, and polyolefin fine particles may be applied as a solid content in an amount of 3 to 15 g / m ² per one surface. preferable.
When the coating amount is less than 3 g / m ² , the paper surface is not completely coated, and the water resistance is reduced. On the other hand, when the coating amount exceeds 15 g / m ² , the coating liquid is not sufficiently dried in the drying zone of the coating machine, and blocking and cockling are likely to occur. Therefore, the coating speed has to be reduced, and the production efficiency deteriorates.

In producing the waterproof paper for printing of the present invention, an apparatus for applying a coating agent composed of an acrylic resin emulsion having a core / shell structure, an inorganic pigment, and polyolefin-based fine particles to a paper substrate is as follows. A known coating machine such as a two-roll, film transfer type size press, a calender size press, a roll coater, an air knife coater, a die coater, a bar coater, a bill blade coater, a blade coater, a short dwell blade coater, and a film transfer coater are appropriately used. .

[0030]

EXAMPLES The present invention will be described below with reference to examples of the present invention, but the present invention is not limited to these examples. Further, "parts" and "%" shown in Examples are parts by weight and% by weight unless otherwise specified.

Example 1 Acrylic resin emulsion having a core / shell structure (Technocoat HT-218, Heisei Techno Co., Ltd.) as a solid content of 100 parts, an inorganic pigment (Mizukasil P-52)
7, Mizusawa Chemical Co., Ltd.) as a solid content of 5 parts, and polyolefin-based fine particles (Chemipearl W-300, Mitsui Chemicals Co., Ltd.) as a solid content of 5 parts, until the coating liquid solids concentration becomes 35% with water. Diluted. Using a bar coater, this coating liquid was coated on a coated paper (New Pearl Coat L 64.0 g / m ^2, manufactured by Mitsubishi Paper Mills, Ltd.) as a solid content at 5 g / m ² on one side.
m ² to obtain water-resistant paper for printing.

Example 2 Inorganic pigment (Mizukasil P-527, Mizusawa Chemical Co., Ltd.)
As solids, and polyolefin-based fine particles (Chemipearl W-300, Mitsui Chemicals, Inc.) as solids
A water-resistant paper for printing was obtained in the same manner as in Example 1 except that parts were blended.

Example 3 Inorganic pigment (Mizukasil P-527, Mizusawa Chemical Co., Ltd.)
As solids, and polyolefin-based fine particles (Chemipearl W-300, Mitsui Chemicals, Inc.) as solids 3 parts
A water-resistant paper for printing was obtained in the same manner as in Example 1 except that parts were blended.

Example 4 Inorganic pigment (Mizukasil P-527, Mizusawa Chemical Co., Ltd.)
Was obtained in the same manner as in Example 1 except that the solid content was 40 parts and the polyolefin-based fine particles (Chemipearl W-300, Mitsui Chemicals, Inc.) were mixed in a solid content of 40 parts.

Example 5 Inorganic pigment (Mizukasil P-527, Mizusawa Chemical Co., Ltd.)
Was obtained in the same manner as in Example 1 except that 35 parts were mixed as a solid content and 40 parts as a solid content of polyolefin-based fine particles (Chemipearl W-300, Mitsui Chemicals, Inc.).

Example 6 A water-resistant paper for printing was obtained in the same manner as in Example 1, except that the amount of coating on the base paper was 2 g / m ² on one side as a solid content.

Example 7 The amount of coating on the base paper was 17 g / m ^{2 on} one side as the solid content.
A water-resistant paper for printing was obtained in the same manner as in Example 1, except that

Comparative Example 1 Ethylene copolymer resin emulsion (HYTEC S-
3121, Toho Chemical Industry Co., Ltd.)
0 parts, 5 parts of an inorganic pigment (Mizukasil P-527, Mizusawa Chemical Co., Ltd.) as a solid content, and 5 parts of polyolefin-based fine particles (Chemipearl W-300, Mitsui Chemical Co., Ltd.) as a solid content. This coating solution was coated on both sides of a coated paper (New Pearl Coat L: 64.0 g / m ² ) using a bar coater so as to have a solid content of 5 g / m ² on one side, and then printed. Waterproof paper was obtained.

Comparative Example 2 Water-based polyester emulsion (HYTEC PE-1)
010, Toho Chemical Industry Co., Ltd.)
Part, an inorganic pigment (Mizukasil P-527, Mizusawa Chemical Co., Ltd.) as a solid content of 5 parts, and polyolefin-based fine particles (Chempearl W-300, Mitsui Chemical Co., Ltd.) as a solid content of 5 parts. This coating solution was coated on a coated paper (New Pearl Coat L6 manufactured by Mitsubishi Paper Mills Co., Ltd.) using a bar coater.
4.0 g / m ² ) was coated on both sides so that the solid content was 5 g / m ² on one side to obtain a waterproof paper for printing.

Comparative Example 3 Anionic surfactant emulsion polymerization Acrylic resin emulsion (Technocoat HT-102, Heisei Techno Co., Ltd.) as a solid content of 100 parts, an inorganic pigment (Mizukasil P)
-527, Mizusawa Chemical Co., Ltd.) as a solid content of 5 parts, and polyolefin-based fine particles (Chemipearl W-300, Mitsui Chemicals Co., Ltd.) as a solid content of 5 parts, and the coating solution solids concentration becomes 35% with water. Diluted. This coating solution was coated on both sides of a coated paper (New Pearl Coat L: 64.0 g / m ² ) using a bar coater so as to have a solid content of 5 g / m ² on one side, and then printed. Waterproof paper was obtained.

Comparative Example 4 100 parts of an acrylic resin emulsion (Technocoat HT-141, Heisei Techno Co., Ltd.) using a protective colloid as a solid content, and an inorganic pigment (Mizukasil P-52)
7, Mizusawa Chemical Co., Ltd.) as a solid content of 5 parts, and polyolefin-based fine particles (Chemipearl W-300, Mitsui Chemicals Co., Ltd.) as a solid content of 5 parts, until the coating liquid solids concentration becomes 35% with water. Diluted. Using a bar coater, this coating liquid was coated on a coated paper (New Pearl Coat L 64.0 g / m ^2, manufactured by Mitsubishi Paper Mills, Ltd.) as a solid content at 5 g / m ² on one side.
m ² to obtain water-resistant paper for printing.

Comparative Example 5 An acrylic resin emulsion having a core / shell structure (Technocoat HT-218, Heisei Techno Co., Ltd.) was diluted with water until the coating liquid solids concentration became 35%. This coating solution was coated on both sides of a coated paper (New Pearl Coat L: 64.0 g / m ² ) using a bar coater so as to have a solid content of 5 g / m ² on one side, and then printed. Waterproof paper was obtained.

Comparative Example 6 An acrylic resin emulsion having a core / shell structure (Technocoat HT-218, Heisei Techno Co., Ltd.) as a solid content of 100 parts, an inorganic pigment (Mizukasil P-52)
7, Mizusawa Chemical Co., Ltd.) as a solid content was mixed in 6 parts, and diluted with water until the coating solution solid content concentration became 35%. This coating solution was coated on a coated paper (Mitsubishi Paper Co., Ltd.) using a bar coater.
Co., Ltd .: New Pearl Coat L 64.0 g / m ² ) was coated on both sides so that the solid content was 5 g / m ² on one side to obtain a waterproof paper for printing.

Comparative Example 7 100 parts of an acrylic resin emulsion having a core / shell structure (Technocoat HT-218, Heisei Techno Co., Ltd.) as a solid content, and polyolefin fine particles (Chemipearl W-300, Mitsui Chemicals, Inc.) were used. Five parts were mixed as a solid content, and diluted with water until the coating solution solid content concentration became 35%. This coating solution was coated on a coated paper (New Pearl Coat L 64.0, manufactured by Mitsubishi Paper Mills Co., Ltd.) using a bar coater.
g / m ² ) to give a solid content of 5 g / m ² on one side to obtain a waterproof paper for printing.

The water-resistant paper for printing of Examples 1 to 7 and Comparative Examples 1 to 6 were evaluated for water resistance, winder workability, printed surface quality, printing workability, blocking, disintegration, cockling, and drying. Are shown in Table 1 below.

(Water Resistance) The water resistance was evaluated by dropping 5 cc of water droplets on the surface of the waterproof paper for printing, and after standing for 24 hours, observing the penetration of water to the back surface. ：: Water does not permeate to the back surface, and no unevenness occurs on the waterproof paper for printing. ：: Water did not penetrate to the back surface, but the water-resistant paper for printing was uneven. Δ: Some penetration of water into the back surface is observed, but there is no practical problem. X: The thing which water permeated the whole surface where the water droplet was dripped was judged as x. The desired water resistance is ○ or more.

(Winder workability) Winder workability was evaluated by evaluating wrinkles and meandering during winding of water-resistant paper for printing. ：: No wrinkling or meandering occurs even when the winder work is performed at a speed of 100 m / min or more. Δ: If the winder operation is performed at a speed of 50 m or more and less than 100 m / min, the operation can be performed without wrinkles or meandering. X: A work that could be performed without wrinkles or meandering when the speed of the winder operation was less than 50 m / min, and a wrinkle or meander generated even at a work speed of less than 50 m / min were determined as x. The target winder workability is △ or more.

(Printed surface quality) The printed surface quality was measured at 8,000 sheets / hour on a sheet-fed lithographic offset rotary printing press (diamond 304, Mitsubishi Heavy Industries, Ltd.) using a waterproof paper for printing (2000 plates, chrysanthemum plate). The superiority of the printed image when four-color offset printing was performed was visually evaluated. ：: Good printed surface quality. Δ: The printed surface quality is slightly inferior, but there is no practical problem. X: The printed surface is poor quality and there is a problem. The target level is △ or more.

(Printing workability) The printing workability was evaluated by printing water-resistant paper for printing (2000 plates, chrysanthemum plate, 2000 sheets) on a sheet-fed lithographic offset rotary printing press (Dia 304, Mitsubishi Heavy Industries, Ltd.).
At the time of printing at four sheets / hour, blocking and running due to slippage when printing four colors were evaluated. ○: Work can be performed without any problem. Δ: Slight occurrence of heavy running and paper slippage is not a problem in practical use. X: Heavy running and paper slippage were frequent and there was a problem in workability. The target is △ or more, but preferably ○.

(Blocking) The blocking was 5 cm
10 sheets of waterproof paper for printing of 5 × 5 cm pieces are stacked at 40 ° C and 9
Under a 0% condition, a load of 400 kg / cm ²
After standing for 0 minutes, the occurrence of blocking was evaluated. 5: Paper thread is not stuck. 4: The paper thread is stuck, but peels off immediately. 3: There is a sound when the paper is peeled off and peeled off. 2: The paper threading is partially adhered completely and does not peel off. 1: The paper threading is completely adhered to the entire surface and does not peel off. The goal is three or more.

(Disintegration property) Waterproof paper for printing is cut into 1 cm squares, 24 g of absolute dry weight is collected, and disintegration work is performed using 2000 g of water with a pulp disintegrator manufactured by Kumagaya Riki Kogyo (based on JIS P8209). Was done. Next, a handsheet was prepared using the pulp slurry after defibration, and the defibration properties were evaluated according to the following criteria. ：: Good disintegration. Δ: Disintegration takes time, but at a practically usable level. ×: Not disintegrated. The goal is more than △.

(Cockling) When the coating liquid is applied on the base paper, a wrinkled wrinkle is generated on the coated paper depending on conditions such as the viscosity of the coating liquid and the coating amount. But that is called cockling. The state was visually evaluated. ：: good without cockling Δ: Cockling occurred slightly, but no practical problem. ×: Cockling frequently occurred, and appearance was poor. The goal is more than △.

(Dryability) The water content after coating was measured to determine whether the coating liquid applied on the base paper was sufficiently dried after passing through the drying zone of the coating machine. ：: sufficiently dried with a water content of 6% or less. Δ: Moisture at 6 to 12% of moisture, but blocking, etc.
There is no practical problem. ×: Moisture exceeds 12%, and a problem such as blocking occurs inside the winding after coating. The goal is more than △.

[0054]

[Table 1]

Evaluation: From the results of Example 1 and Comparative Examples 1 to 4, it is clear that an acrylic resin emulsion having a core / shell structure is preferable as a waterproofing agent used for waterproofing paper for printing.

From the results of Comparative Examples 5 to 7, the water-resistant paper for printing obtained by applying only the acrylic resin emulsion having a core / shell structure showed that blocking under high-temperature and high-humidity conditions, winder workability, and printing were performed. Waterproof paper for printing coated with a coating liquid comprising an acrylic resin emulsion having a core / shell structure and an inorganic pigment having poor workability has poor blocking and winder workability, and an acrylic having a core / shell structure. Water-resistant paper for printing coated with a coating liquid consisting of a resin-based resin emulsion and polyolefin-based fine particles,
It is clear that the printed surface quality and printing workability are poor.

From the results of Examples 1 to 7, the coating liquid was
The total of the solid content of the inorganic pigment and the polyolefin-based fine particles is 6 to 75 parts by weight per 100 parts by weight of the solid content of the acrylic resin emulsion having a shell structure, and the acrylic resin emulsion having a core / shell structure has a core / shell structure. The solid content of the inorganic pigment is 3 per 100 parts by weight of the solid content.
When the above coating solution is applied as a solid to a surface of 3 to 15 g / m ² , water resistance, winder workability, finished surface quality, printing workability, blocking, disintegration It is evident that a water-resistant paper for printing having very good cockling and drying properties can be obtained.

[0058]

The waterproof paper for printing of the present invention comprises an acrylic resin emulsion having a core / shell structure, an inorganic pigment,
It is a water-resistant paper for printing which is composed of polyolefin-based fine particles, has high water resistance and excellent printability, does not generate blocking, has good winder and printing workability, and has excellent disintegration properties.

Claims (4)

[Claims] An acrylic resin emulsion having a core / shell structure on one or both sides of a base paper, an inorganic pigment,
A waterproof paper for printing characterized by being coated with a coating liquid comprising polyolefin-based fine particles. 2. The coating liquid has a total of 6 to 75 parts by weight of a solid content of an inorganic pigment and polyolefin fine particles per 100 parts by weight of a solid content of an acrylic resin emulsion having a core / shell structure. The waterproof paper for printing according to claim 1, wherein: 3. The coating liquid according to claim 1, wherein the solid content of the inorganic pigment is 3 to 72 parts by weight per 100 parts by weight of the solid content of the acrylic resin emulsion having a core / shell structure. 2. Waterproof paper for printing according to 2. 4. The method according to claim 1, wherein the coating liquid is applied in a solid content of 3 to 15 g / m ² per one side.
The waterproof paper for printing according to any one of claims 1 to 3.