JP2828737B2 - Coated paper for printing - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated printing paper using waste paper, and more particularly to a coated printing paper having good light fastness, which effectively uses waste pressure-sensitive copying paper. It is about.

[Conventional technology]

In general, a coated paper for printing is produced by coating a coating composition containing a pigment and an adhesive as main components on a base paper obtained by making pulp fiber, drying and then super-calendering.

On the base paper of the coated paper for printing, pulp obtained by subjecting wood to chemical treatment, mechanical treatment, semi-chemical / semi-mechanical treatment, etc. is beaten chemically so-called virgin pulp, A base paper obtained by adding a filler, a sizing agent, a fixing agent, a dye, and the like to the pulp slurry and performing papermaking is used. In this paper making process, the adhesive is often subjected to a surface treatment in order to increase the surface strength of the paper.

Thus, coated paper for printing obtained using such a base paper is printed by lithographic printing, letterpress printing, flexographic printing or gravure printing, and the like, and is used for calendars, posters, magazines, books, flyer advertisements, catalogs, etc. Although used in a wide range of fields, photofading (yellowing) generally occurs easily, and improvement thereof is desired.

Also, the demand for paper is steadily increasing with the development of the economy. For this reason, in recent years, from the viewpoint of effective use of resources,
There is a growing trend toward recycled pulping of waste paper and its effective use.

At present, the amount of waste paper used in Japan exceeds 50% of the raw material used for paper and paperboard production, and there is an increasing demand for recycling more waste paper from the viewpoint of effective use of resources.

Recycled paper that can be recycled and pulped is newspaper, cardboard, magazine, imitation, color (including art), white, card, special white, medium white, white manila, notch, middle quarrel, tea imitation paper ( Western paper), mount, ground ticket, ball, thermal paper, pressure-sensitive copying paper,
CP0.

As a method of recycling and pulping pressure-sensitive copying paper waste paper from these waste papers, generally, a disintegration step of disintegrating the waste paper in an alkaline solution to obtain a pulp suspension, and a rough selection for separating foreign matter. Recycling pulping through a selection process, a flotator process for foam-separating dye-containing microcapsules and a developer, a washing process for washing the dye-containing microcapsules and a developer, and a bleaching process for whitening the color The method has been adopted. The recycled pulping method of used pressure-sensitive copying paper is as follows.
Since it is necessary to go through a very complicated process, the pressure-sensitive copying paper is still only partially used.

[Problems to be solved by the invention]

The present invention relates to a coated paper for printing using waste paper, and more particularly to an object of providing a coated paper for printing with good light fastness by effectively utilizing recycled pulp from pressure-sensitive copying paper waste paper. It is.

[Means for solving the problem]

The present invention relates to a base paper made by adding an amine compound and / or a quaternary ammonium salt compound to a pulp slurry containing recycled pulp or a pulp slurry containing recycled pulp obtained from a pressure-sensitive copying paper waste paper. A coated paper for printing characterized by having a coated layer containing the same.

[Action]

In the present invention, the recycled pulp contained in the base paper is obtained by recycling used pressure-sensitive copying paper. This used pressure-sensitive copying paper contains microcapsules containing an electron-donating dye on one side of the base paper. "Top paper" coated with a layer, "Bottom paper" coated with a layer containing an electron-accepting compound (color developing agent) which reacts with electron donating to form a color, and a layer containing microcapsules on one side of base paper "Medium paper" in which a layer containing a color developer is applied on the other side, and "self-coloring paper" in which microcapsules and a color developer are laminated or mixed on the same side of the base paper are known. Waste paper used by appropriately combining them, semi-finished products and waste paper generated in the process of manufacturing these pressure-sensitive copy papers.

When disintegrating the above pressure-sensitive copy paper waste paper, it is advisable to disintegrate it with an alkaline aqueous solution in order to accelerate the disintegration, and as the alkaline agent, sodium hydroxide, potassium hydroxide,
Examples include calcium hydroxide, sodium silicate, sodium carbonate, potassium carbonate, sodium hypochlorite, calcium hypochlorite, and the like. Among these, hypochlorite is particularly effective and preferred for used paper that has already developed a color because it promotes disaggregation and oxidizes and decomposes dyes and the like to bleach.
In addition, when disintegrating used pressure-sensitive copying paper, foreign materials such as plastics and sticky substances are often included, and when disintegrated, they are crushed into small pieces by a stirrer or the like, which may deteriorate the separation effect in the selection process. . Therefore, it is preferable to adjust the degree of disaggregation.

If foreign matter is crushed into small pieces by a stirrer, etc., not only will the separation effect in the selection process be poor, but if the paper is made using recycled pulp, the pressure-sensitive adhesive will block the wire in the paper making process. The press roll and the blanket,
There is a problem that the paper breaks and the papermaking efficiency is significantly reduced. Further, there is a problem in that spots are formed on the paper surface, which adversely affects paper layer formation or quality.
When a device such as a pulper is determined, the method of adjusting the degree of defibration may be adjusted by adjusting the length of defibration time, pulp concentration, water temperature, alkali addition amount, etc., and is not particularly limited.

The thus-obtained recycled pulp slurry of the pressure-sensitive copying paper waste paper is further sent to a selective process, where it is screened to separate foreign substances. If a rough selection process is provided before the fine selection process, large foreign matter can be removed in the rough selection process before shifting to the fine selection process, so that clogging of the screen in the fine selection process can be prevented.

In the present invention, the recycled pulp of the used pressure-sensitive copying paper obtained by the defibration treatment as described above is used by being blended with another pulp, for example, a so-called virgin pulp. The base paper obtained by blending this recycled pulp with virgin pulp and making paper is low in tension and has good smoothness. To take advantage of this characteristic, 5-95% by weight of the total pulp constituting the base paper is preferable. Is 10 ~
It is desirable to contain it in the range of 90% by weight. By the way, 5
If the amount is less than 10% by weight, the desired effect is not sufficient.
On the other hand, if the content is 95% by weight or more, it is difficult to obtain base paper having excellent paper strength even when used in combination with coniferous virgin pulp. Further, if this recycled pulp is used without beating, a base paper having sufficient paper strength cannot be obtained. For this reason, it is desirable to process by a beater in a pre-process of a paper machine. In the case of beating treatment, the recycled pulp may be treated alone, or may be blended with virgin pulp and beaten together.

The degree of beating depends on the amount of recycled pulp, the type of paper machine,
What is necessary is just to select suitably according to the physical properties of a coating composition, the kind of a coater, the required quality of a product, etc.

As the beating machine, a conical refiner, a single refiner, a double disc refiner, or the like is used, but the use of a double disc refiner is more preferable in consideration of power.

Thus, in the present invention, a base paper obtained by adding an amine compound and / or a quaternary ammonium salt compound to a pulp slurry containing a recycled pulp or a recycled pulping step of used pressure-sensitive copying paper waste paper. Is an important requirement.

By the way, if the recycled pulp of the pressure-sensitive copying paper waste paper is used as it is, the microcapsules remaining due to the pressure during the smoothing process in the calender of the paper machine or the super calender after the coater are destroyed and react with the developer. Color, which reduces the commercial value.

When an amine compound and / or a quaternary ammonium salt compound is added to the step of regenerating pulverized pressure-sensitive copying paper and / or the resulting pulp slurry containing the regenerated pulp, these compounds become electron donating dyes. The contact reaction between the compound and the electron-accepting compound (color developing agent) is prevented, thereby suppressing color development.

Examples of the amine compound and / or quaternary ammonium salt compound used in the present invention include an aliphatic amine salt and an aliphatic quaternary ammonium salt.
Examples include cationic surfactants such as ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, carboxybetaine type, and aminocarboxylates, and amphoteric surfactants. Furthermore, cation-modified starch, cation-modified latex, cation-modified polyvinyl alcohol, cation-modified plant gum, polyethylene imine, polyamine, polyamide / polyamine,
Among polyacrylamides, urea formalin resins, melamine formalin resins, polyamide resins, and the like, some of those generally used as retention aids or paper strength enhancers are also effective.

The specific substance of the amine compound and / or quaternary ammonium salt compound used depends on the types and amounts of the electron-donating dye and the electron-accepting substance (developer). Become. The addition amount is effective at 0.05 to 10% by weight based on the dry pulp.

It is effective to add the amine compound and / or the quaternary ammonium salt compound to the pulp slurry before the papermaking containing the recycled pulping step or the obtained recycled pulp.

The papermaking of the pulp slurry to which the amine compound and / or the quaternary ammonium salt compound is added may be made by any of ordinary acidic papermaking and neutral papermaking, but neutral papermaking is considered in consideration of recovery of damaged paper and light resistance. Is preferred. In the case of neutral papermaking, calcium carbonate is blended as a filler and the papermaking pH is adjusted to 6
Adjust to 9 and make paper. When the pH is 6 or less, the solubility of calcium carbonate increases, and the yield during papermaking deteriorates. On the other hand, when the pH is 9 or more, alkali burning of the pulp occurs, and the whiteness decreases.

As the filler, in addition to calcium carbonate, generally known and used fillers in the papermaking industry, for example, talc, kaolin, clay, calcined kaolin, delamikaolin, titanium dioxide, calcium sulfate, calcium hydroxide, aluminum hydroxide, zinc hydroxide, Mineral fillers such as magnesium hydroxide, magnesium carbonate, magnesium sulfate, magnesium silicate, white carbon, and bentonite, and organic synthetic fillers such as polystyrene resin fine particles, urea formalin resin fine particles, and fine hollow particles are appropriately selected and used in combination. Further, fillers contained in waste paper, broke, and the like can also be used effectively.

Examples of the internal additive for papermaking include various conventionally used anionic, nonionic, cationic or amphoteric retention enhancers, drainage improvers, paper strength enhancers and sizing agents, and the like. Sizing agents such as alkyl ketene dimer sizing agent, alkenyl succinic anhydride sizing agent, styrene-acrylic sizing agent, stearic anhydride sizing agent, petroleum resin sizing agent, rosin sizing agent, etc. Organic compounds such as acrylamide, polyethyleneimine, polyamine, polyamide / polyamine, vegetable gum, urea formalin resin, melamine formalin resin, polyvinyl alcohol, latex, polyethylene oxide, polyamide resin, and derivatives or modified products thereof, and aluminum sulfate, etc. Water-soluble aluminum salt, colloidal silica In combination one inorganic compounds such as bentonite or two or more appropriately used,
Further, internal additives for papermaking such as dyes, pH adjusters, defoamers, pitch control agents, slime control agents and the like are appropriately added according to the use of paper.

As the paper machine, a fourdrinier paper machine, a twin wire paper machine, a round net paper machine or the like which is usually used can be used. A multi-cylinder dryer or a Yankee dryer can be used in the drying section of the paper machine.

In the present invention, a coating layer containing a pigment and an adhesive as main components is formed on the base paper thus obtained, but in the present invention, formation of a coating layer containing an alkaline pigment is essential. The reason for the requirement is that, as described above, the base paper contains an amine compound and / or a tertiary pulp slurry to prevent discoloration in the pulp slurry containing the recycled pulp and / or in the pulp slurry containing the obtained recycled pulp. A quaternary ammonium salt compound is added. Kaolin,
If a coating layer consisting only of a non-alkali pigment such as clay is formed, the whiteness and light resistance of the coated paper will be poor, and the commercial value will be reduced.

On the other hand, by containing the alkaline pigment in the coating layer in an amount of 5% by weight or more of the total pigment, the whiteness of the coated paper is improved, the light resistance is further improved, and the coated paper having excellent printability is obtained. You get it.

Examples of the alkaline pigment include heavy calcium carbonate, light calcium carbonate, satin white, aluminum hydroxide, and magnesium carbonate.

These alkaline pigments have high whiteness, and when a coating composition containing these pigments is provided on base paper, coated paper having high whiteness can be obtained. Among them, satin white, heavy calcium carbonate, light calcium carbonate, and the like are preferable.

The content of these pigments is preferably 5% by weight or more based on the solids of all the pigments in order to obtain the above effects, and more preferably 10% by weight or more in order to obtain more effects.

Examples of the adhesive include proteins such as casein, soy protein, and synthetic protein; conjugated diene copolymer latex such as styrene / butadiene copolymer and methyl methacrylate / butadiene copolymer; latex; acrylic acid ester and / or methacrylic acid. An acrylic polymer latex such as an ester polymer or a copolymer, a vinyl polymer latex of an ethylene / vinyl acetate polymer, or these various polymer latexes are modified with a functional group-containing monomer such as a carboxyl group. Alkali-soluble, alkali-swellable or alkali-insoluble polymers Latex and various synthetic resin polymers called binder pigments; synthetic resin adhesives such as polyvinyl alcohol, olefin, maleic anhydride resin, melamine resin, etc., and oxidized starch , Positive starch, esterified starch, dextrin, etc. Starches; carboxymethylcellulose, 1 or more conventional coated paper for adhesives, such as such as cellulose derivatives such as hydro-oxy cellulose is appropriately selected and used.

In general, the adhesive is blended in an amount of 4 to 50 parts by weight, more preferably about 10 to 30 parts by weight, based on 100 parts by weight of the pigment. Various assistants such as an antifoaming agent, a colorant, a mold release agent, a flow modifier, and a preservative are appropriately blended in the coating liquid as needed, but as an auxiliary for promoting solidification of the coating layer. For example, about 0.1 to 10 parts by weight of a salt of a polyvalent metal such as amine, amide, polyacrylamine or the like or zinc, aluminum, magnesium, calcium, barium or the like may be added to 100 parts by weight of the pigment.

Coating liquid is used in the production of general coated paper, for example, blade coater, air knife coater, roll coater, reverse coater, bill blade coater, curtain coater, die slot coater, gravure coater, champlex coater, size press coater, etc. One or multiple layers are coated on base paper by an on-machine or off-machine coater provided with a double-side or single-side coating device. The solid content concentration is generally 40 to 75% by weight
However, in consideration of operability, a range of 45 to 70% by weight is preferable. The coating amount of the coating liquid on the base paper is generally about 3 to 50 g / m ² per one side in terms of dry weight, but 5 to 40 g / m ^{2 in} consideration of whiteness, light fastness and printability of the obtained coated paper. The range of the degree is preferable.

In addition, as a method for drying the wet coating layer, conventionally known various methods such as steam heating, blast heating, gas heater heating, high-frequency heating, electric heater heating, infrared heater heating, leather heating, electron beam heating, etc. A drying method can be appropriately adopted.

The coated paper thus obtained has excellent light fastness and excellent printability.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples, but is not limited to these. In the examples, parts and% indicate parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 <Preparation of base paper> Water was charged into a pulper such that the pressure-sensitive copying paper used paper and the pulp concentration became 5%, and 2% of a sodium hydroxide solution was added to the used paper, followed by disintegration for 30 minutes. .

This suspension was adjusted to a pulp concentration of 3.5%, and was carefully selected using a screen with a slit width of 0.5 mm (CH-type high-concentration screen manufactured by Aikawa Iron Works Co., Ltd.).

Polyethyleneimine (BASF; Polymin SK) was added as an amine compound to the accept pulp at 1% based on the dry pulp, and beaten with a double desk refiner.
400 ml of recycled pulp with a freeness of 400 ml was obtained. LBK which was beaten this regenerated pulp 4 times, each to 500ml freeness
P90 parts, pulp slurry prepared by mixing NBKP 6 parts,
Heavy calcium carbonate was added so that the paper ash content was 10%, and 0.5% of a sulfuric acid band and 0.5% of cationic starch (manufactured by Oji National Co., Ltd .; trade name: 0NL-400) were added.
Alketene dimer (Dick Hercules; trade name; Harcon) 0.1% as a sizing agent; cationic polyacrylamide (Allide Colloid; trade name;
Percoll 155] 0.05% was added and mixed.

Thus the pulp slurry prepared by papermaking with fourdrinier multi cylinder type cylinder dryer paper machine, and a size press so as oxidized starch becomes 2 g / m ^2, to obtain a coated paper sheet having a basis weight of 64 g / m ² .

<Preparation of coating composition> 80 parts of kaolin [manufactured by EMC; trade name; UW-90], heavy calcium carbonate [manufactured by Bihoku Powder Chemical Industry Co., Ltd .; trade name; softon
1800) 10 parts, Satin White 10 parts and sodium hydroxide 0.
1 part and 0.3 part of sodium polyacrylate are dispersed in a Coreth disperser, and 5 parts of oxidized starch, 13 parts of styrene-butadiene latex and 0.05 part of a silicon-based antifoaming agent are added, and the mixture is stirred and mixed. A 60% coating solution was prepared.

<Coating> The coating composition obtained as described above was coated on both sides of the base paper using a blade coater so that the dry weight was 20 g / m ² per one side, dried with a drier, and Pressure treatment was performed with a render to obtain a double-side coated paper.

Table 1 shows the results of quality evaluation of the coated paper thus obtained.

Example 2 <Preparation of base paper> Water was charged into a pulper so that the pressure-sensitive copying paper used paper and the pulp concentration became 5%, and a sodium hypochlorite solution was added to the used paper at 1% to the used paper. And disintegrated for 30 minutes.

This suspension was adjusted to a pulp concentration of 3.5%, and was carefully selected using a screen with a slit width of 0.5 mm (CH-type high-concentration screen manufactured by Aikawa Iron Works Co., Ltd.).

Cationic polyacrylamide [manufactured by Kurita Kogyo Co., Ltd .; trade name: Crifix CP-66]
2] was added to dry pulp at 1% and beaten with a double desk refiner to obtain a recycled pulp having a freeness of 400 ml. To 10 parts of the recycled pulp, 80 parts of LBKP beaten to 500 ml of freeness and 10 parts of NBKP were added to a pulp suspension prepared by adding heavy calcium carbonate so that the paper ash content was 10%.
%, Cationic starch (manufactured by Oji National Co., Ltd .; trade name: 0NL-400) 0.5%, and an alkyl ketene dimer [Dick Hercules Co., Ltd.] as a sizing agent.
0.1%, cationic polyacrylamide (manufactured by Allied Colloid Co., Ltd .; trade name: Percoll)
155] 0.05% was added.

Thus the pulp slurry prepared by papermaking with fourdrinier multi cylinder type cylinder dryer paper machine, and a size press so as oxidized starch becomes 2 g / m ^2, to obtain a coated paper sheet having a basis weight of 64 g / m ² .

<Preparation of coating composition> Kaolin (manufactured by EMC; trade name; UW-90) 70 parts, heavy calcium carbonate [trade name of Bihoku Powder Chemical Industry Co., Ltd .; softon 18
00] 10 parts, Sachin white 10 parts and sodium hydroxide 0.1
Parts and 0.3 parts of sodium polyacrylate were placed in a Coreth dispersing machine and dispersed, and 5 parts of oxidized starch, 13 parts of styrene-butadiene latex and 0.05 part of a silicone-based antifoaming agent were added, and mixed by stirring. % Coating solution was prepared.

<Coating> The coating composition obtained as described above was coated on both sides of the base paper using a blade coater so that the dry weight was 20 g / m ² per one side, dried with a drier, and Pressure treatment was performed with a render to obtain a double-side coated paper.

Table 1 shows the results of quality evaluation of the coated paper thus obtained.

Example 3 <Preparation of base paper> Water was charged into a pulper such that the pressure-sensitive copying paper used paper and the pulp concentration became 5%, and a sodium hypochlorite solution was added to the used paper at 1% to the used paper. And disintegrated for 30 minutes.

This pulp slurry was adjusted to a pulp concentration of 3.5%,
It was carefully selected using a screen with a slit width of 0.5 mm (CH type high concentration screen manufactured by Aikawa Iron Works Co., Ltd.).

Cationic polyacrylamide [manufactured by Kurita Kogyo Co., Ltd .; trade name: Crifix CP-66]
2] was added to dry pulp at 1% and beaten with a double desk refiner to obtain a recycled pulp having a freeness of 400 ml. Heavy calcium carbonate was added to 30 parts of the recycled pulp, and 60 parts of LBKP and 10 parts of NBKP, each of which was beaten to 500 ml of freeness, and heavy calcium carbonate was added so that the paper ash content was 10%. ,
Polyacrylamide [Arakawa Chemical Co., Ltd .; trade name; KW67
7) Add 0.5% and further, as a sizing agent, alkyl ketene dimer [manufactured by Arakawa Chemical Co., Ltd .; trade name; SPK-902] 0.1
%, Cationic polyacrylamide [manufactured by Allied Colloid Co .; trade name; Percoll 155] 0.05%.

The pulp slurry thus adjusted was subjected to papermaking using a fourdrinier multi-cylinder cylinder dryer paper machine to obtain a base paper for coated paper having a basis weight of 65 g / m ² .

<Preparation of coating composition> Kaolin (manufactured by EMC; trade name; UW-90) 50 parts, heavy calcium carbonate [trade name of Bihoku Powder Chemical Industry Co., Ltd .; softon 18
00] 30 parts, satin white 20 parts and sodium hydroxide 0.1
Parts and 0.3 parts of sodium polyacrylate were placed in a Coreth dispersing machine and dispersed, and 5 parts of oxidized starch, 13 parts of styrene-butadiene latex and 0.05 part of a silicone-based antifoaming agent were added, and mixed by stirring. % Coating solution was prepared.

<Coating> The coating composition obtained as described above was coated on both sides of the base paper using a blade coater so that the dry weight was 20 g / m ² per one side, dried with a drier, and Pressure treatment was performed with a render to obtain a double-side coated paper.

Table 1 shows the results of quality evaluation of the coated paper thus obtained.

Example 4 <Preparation of base paper> Water was charged into a pulper such that the pressure-sensitive copying paper used paper and the pulp concentration became 5%, and a sodium hypochlorite solution was added to the used paper at 1% to the used paper. And disintegrated for 30 minutes.

This pulp slurry was adjusted to a pulp concentration of 3.5%,
It was carefully selected using a screen with a slit width of 0.5 mm (CH type high concentration screen manufactured by Aikawa Iron Works Co., Ltd.).

To this accept pulp, a cationic surfactant [manufactured by Kao Corporation; trade name: Kotamine 24P] was added at 1% to the dry pulp, beaten with a double desk refiner, and obtained with 400 ml of freeness recycled pulp. Was. To 60 parts of the recycled pulp, 30 parts of LBKP beaten to 500 ml of freeness and 10 parts of NBKP were added to a pulp suspension prepared by adding heavy calcium carbonate so that the paper ash content was 10%. %, Polyacrylamide (Arakawa Chemical Co., Ltd .; trade name; KW677) 0.7%
Further, as a sizing agent, 0.1% of an alkyl ketene dimer [manufactured by Arakawa Chemical Co., Ltd .; trade name; SPK-902] 0.1%, and 0.05% of cationic polyacrylamide [manufactured by Allied Colloid Co., trade name; Percoll 155] were added.

The pulp slurry thus adjusted was subjected to papermaking using a fourdrinier multi-cylinder cylinder dryer paper machine to obtain a base paper for coated paper having a basis weight of 65 g / m ² .

<Preparation of coating composition> 30 parts of kaolin [manufactured by EMC; trade name; UW-90], heavy calcium carbonate [trade name of Bihoku Powder Chemical Industry Co., Ltd .; softon 18]
00] 40 parts, satin white 30 parts and sodium hydroxide 0.1
Parts and 0.3 parts of sodium polyacrylate were placed in a Coreth dispersing machine and dispersed, and 5 parts of oxidized starch, 13 parts of styrene-butadiene latex and 0.05 part of a silicone-based antifoaming agent were added, and mixed by stirring. % Coating solution was prepared.

<Coating> The coating composition obtained as described above was coated on both sides of the base paper using a blade coater so that the dry weight was 20 g / m ² per one side, dried with a drier, and Pressure treatment was performed with a render to obtain a double-side coated paper.

Table 1 shows the results of quality evaluation of the coated paper thus obtained.

Comparative Example 1 <Preparation of base paper> Water was charged into a pulper so that the used pressure-sensitive copying paper and the pulp concentration were 5%, and the mixture was disintegrated for 30 minutes.

This pulp slurry was adjusted to a pulp concentration of 3.5%,
It was carefully selected using a screen with a slit width of 0.5 mm (CH type high concentration screen manufactured by Aikawa Iron Works Co., Ltd.).

This accept pulp was beaten with a double desk refiner to obtain 400 ml of recycled pulp having a freeness of 400 ml. Talc was added to 10 parts of the recycled pulp, and 30 parts of LBKP and 10 parts of NBKP, each of which had been beaten to a freeness of 500 ml, were added with talc so that the paper ash content was 10%. 0.5%, sulfate band 3
% Was added.

The pulp slurry thus adjusted is subjected to papermaking using a fourdrinier multi-cylinder cylinder dryer paper machine, and the oxidized starch is pressed to a size of ² g / m ² to produce a base paper for coated paper having a basis weight of 65 g / m ^2. Obtained.

<Preparation of coating composition> 80 parts of kaolin [manufactured by EMC; trade name; UW-90], heavy calcium carbonate [trade name of Bihoku Powder Chemical Industry Co., Ltd .; softon 18]
00] 10 parts, Sachin white 10 parts and sodium hydroxide 0.1
Parts and 0.3 parts of sodium polyacrylate were placed in a Coreth dispersing machine and dispersed, and 5 parts of oxidized starch, 13 parts of styrene-butadiene latex and 0.05 part of a silicone-based antifoaming agent were added, and mixed by stirring. % Coating solution was prepared.

<Coating> The coating composition obtained as described above was coated on both sides of the base paper using a blade coater so that the dry weight was 20 g / m ² per one side, dried with a drier, and Pressure treatment was performed with a render to obtain a double-side coated paper.

Table 1 shows the results of quality evaluation of the coated paper thus obtained.

Comparative Example 2 In the same manner as in Example 1 <Preparation of base paper> to obtain a coated paper for sheet having a basis weight of 65 g / m ^2.

<Preparation of coating composition> A coating liquid having a solid concentration of 60% was prepared in the same manner as in Example 1 except that 100 parts of kaolin (manufactured by EMC; UW-90) was used as a pigment.

<Coating> The coating composition obtained as described above was coated on both sides of the base paper using a blade coater so that the dry weight was 20 g / m ² per one side, dried with a drier, and Pressure treatment was performed with a render to obtain a double-side coated paper.

Table 1 shows the results of quality evaluation of the coated paper thus obtained.

<Quality evaluation method> 1. Whiteness: Measured by JIS P-8123 Hunter reflectance.

2. Light resistance: Weather meter (Toyo Rika Kogyo Co., Ltd.)
Using a single lamp, measure the whiteness after irradiating with ultraviolet light for 16 hours.

3. Base paper pH: Measured in accordance with JIS P-8133 water extraction pH.

〔effect〕

As is clear from the results in Table 1, the coated printing paper obtained in each of the examples of the present invention had high whiteness and transparent light resistance.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) D21H 1 / 22,3 / 38,3 / 48 D21H 11/14

Claims (5)

(57) [Claims] An alkali pigment is added to a base paper obtained by adding an amine compound and / or a quaternary ammonium salt compound to a pulp slurry containing recycled pulp at the step of reclaiming pressure-sensitive copying paper waste paper or the obtained recycled pulp. A coated paper for printing characterized by forming a coated layer containing: 2. A method of producing a recycled pulp of waste pressure-sensitive copying paper into base paper.
The coated paper for printing according to claim 1, wherein the content of the coated paper is about 95% by weight. 3. The coated paper for printing according to claim 1, wherein the base paper is made by adding 0.05 to 10% by weight of an amine compound and / or a quaternary ammonium salt compound. 4. The coated paper for printing according to claim 1, wherein the total amount of the pigment contained in the coating layer is at least 5% by weight of an alkaline pigment. 5. A base paper having a hot water extraction pH (JIS P 8133) of 6-9.
The coated paper for printing according to claim 1, wherein: