COATED PRINTING PAPER

Abstract

The present invention provides a coated printing paper having a base paper, and a coating layer arranged on at least one surface of the base paper, wherein, an outermost coating layer positioned on the outermost side with respect to the base paper contains at least kaolin, calcium carbonate, starches, a latex, a dispersant, a lubricant and a cationic resin, in the outermost coating layer, a total amount of the starches and the latex is 5 parts by mass or more and 13 parts by mass or less, and an amount of the dispersant is 0.02 part by mass or more and 0.3 part by mass or less, an amount of the lubricant is 0.25 part by mass or more and 0.6 part by mass or less, and an amount of the cationic resin is 0.25 part by mass or more and 0.5 part by mass or less, with respect to 100 parts by mass of the pigment containing kaolin and calcium carbonate in the outermost coating layer, and a mass content ratio of the kaolin to the calcium carbonate in the outermost coating layer is kaolin:calcium carbonate=1:9 to 6:4, and a mass content ratio of the starches to the latex in the outermost coating layer is starches:latex=1:9 to 4:6.

According to the present invention, a coated printing paper having printing stain resistance, resistance to color density unevenness and dullness resistance can be provided.

Claims

1. A coated printing paper having a base paper, and a coating layer arranged on at least one surface of the base paper, wherein, an outermost coating layer positioned on the outermost side with respect to the base paper contains at least kaolin, calcium carbonate, starches, a latex, a dispersant, a lubricant and a cationic resin, in the outermost coating layer, a total amount of the starches and the latex is 5 parts by mass or more and 13 parts by mass or less, and an amount of the dispersant is 0.02 part by mass or more and 0.3 part by mass or less, an amount of the lubricant is 0.25 part by mass or more and 0.6 part by mass or less, and an amount of the cationic resin is 0.25 part by mass or more and 0.5 part by mass or less, with respect to 100 parts by mass of the pigment containing kaolin and calcium carbonate in the outermost coating layer, and a mass content ratio of the kaolin to the calcium carbonate in the outermost coating layer is kaolin: calcium carbonate=1:9 to 6:4, and a mass content ratio of the starches to the latex in the outermost coating layer is starches:latex=1:9 to 4:6.

Description

EXAMPLES

[0059] The present invention is described below more specifically using examples. It should be noted that the present invention is not limited to these examples. Here, “part by mass” and “% by mass” each represent “parts by mass” and “% by mass” of the dry solid content or the substantial component amount. The coating amount of the coating layer represents the dry solid content.

[0060] <Base Paper>

[0061] To pulp slurry composed of 100 parts by mass of LBKP having a freeness of 400 mL csf, 8 parts by mass of calcium carbonate as a filler, 1.0 part by mass of an amphoteric starch, 0.8 part by mass of aluminum sulfate, and an internal sizing agent were added to make a paper stock, which was formed into raw paper using the Fourdrinier papermaking machine. Starch was adhered to both sides of the obtained raw paper with a size press apparatus and the paper was subjected to machine calendering processing to prepare a base paper.

[0062] <Coating Composition of Outermost Coating Layer>

[0063] The coating composition of the outermost coating layer was prepared according to the following contents.

[0064] Kaolin: the number of parts is shown in Tables 1 and 2

[0065] Calcium carbonate: the number of parts is shown in Tables 1 and 2

[0066] Silica: the number of parts is shown in Tables 1 and 2

[0067] Starches: the type and the number of parts are shown in Tables 1 and 2

[0068] Latex: the type and the number of parts are shown in Tables 1 and 2

[0069] Dispersant: the type and the number of parts are shown in Tables 1 and 2

[0070] Lubricant: the type and the number of parts are shown in Tables 1 and 2

[0071] Cationic resin: the type and the number of parts are shown in Tables 1 and 2

[0072] The above contents were blended, mixed and dispersed with water, and the concentration was adjusted to 48% by mass.

[0073] (Coated Printing Paper)

[0074] Coated printing paper was prepared by the following procedure.

[0075] The coating composition of the outermost coating layer was applied on the both surfaces of the base paper using a blade coater, and then dried. After the drying, calendering processing was performed. The coating amount of the coating composition was 14 g/m.sup.2 per one surface.

TABLE-US-00001 TABLE 1 Resis- tance to Pigment Binder Cationic Prin- color Calcium Starches Latex Dispersant Lubricant resin ting den- Dull- Kaolin carbonate Silica Type Type Type Type Type stain sity ness Part Part Part Part Part Part Part Part resis- uneven- resis- by mass by mass by mass by mass by mass by mass by mass by mass tance ness tance Example 10 90 Urea phosphate Styrene- Acrylic Calcium Modified 5 4 5  1 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 30 70 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5  2 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5  3 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 4 5  4 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 32 48 20 Urea phosphate Styrene- Acrylic Calcium Modified 5 4 4  5 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 24 36 40 Urea phosphate Styrene- Acrylic Calcium Modified 5 3 3  6 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5  7 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 9   0.3 degree = 0.01) 1   Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5  8 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 7   0.3 degree = 0.01) 3   Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5  9 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 6   0.3 degree = 0.01) 4   Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 4 5 5 10 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.005) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5 11 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.002) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5 12 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.05) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 4 3 13 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.09) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 4 3 14 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 4.2 0.3 degree = 0.01) 0.8 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 3 4 5 15 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 11.1  0.3 degree = 0.01) 1.9 Example 40 60 Phosphate Styrene- Acrylic Calcium Modified 4 4 3 16 esterified starch butadiene type stearate polyamide 1.5 copolymer resin 0.6 0.5 8.5 0.3 Example 40 60 Urea phosphate Ethylene- Acrylic Calcium Modified 5 3 3 17 esterified starch vinyl type stearate polyamide (Average urea acetate resin 0.6 0.5 substitution copolymer 0.3 degree = 0.01) 8.5 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5 18 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.1 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 4 5 19 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.02 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Polycarboxylic Calcium Modified 4 4 4 20 esterified starch butadiene acid stearate polyamide (Average urea copolymer type 0.6 0.5 substitution 8.5 resin degree = 0.01) 0.3 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5 21 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.45 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5 22 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.25 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Ammonium Modified 4 4 5 23 esterified starch butadiene type oleate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5 24 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.4 substitution 8.5 0.3 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5 25 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.25 substitution 8.5 0.3 degree = 0.01) 1.5 Example 40 60 Urea phosphate Styrene- Acrylic Calcium Modified 5 5 5 26 esterified starch butadiene type stearate polyamide (Average urea copolymer resin 0.6 0.5 substitution 8.5 0.3 degree = 0.01) 1.5

TABLE-US-00002 TABLE 2 Resis- tance to Pigment Binder Cationic Prin- color Calcium Starches Latex Dispersant Lubricant resin ting den- Dull- Kaolin carbonate Silica Type Type Type Type Type stain sity ness Part Part Part Part Part Part Part Part resis- uneven- resis- by mass by mass by mass by mass by mass by mass by mass by mass tance ness tance Comparative 40 60 — Styrene- Acrylic Calcium Modified 1 3 3 Example 0 butadiene type stearate polyamide  1 copolymer 10 resin 0.3 0.6 0.5 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 2 4 4 Example esterified starch butadiene type stearate polyamide  2 5 copolymer 5 resin 0.3 0.6 0.5 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 5 2 2 Example esterified starch butadiene type stearate polyamide  3 0.5 copolymer 2.5 resin 0.3 0.6 0.5 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 2 3 4 Example esterified starch butadiene type stearate polyamide  4 2.4 copolymer 13.6 resin 0.3 0.6 0.5 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 4 2 4 Example esterified starch butadiene type stearate polyamide  5 1.5 copolymer 8.5 resin 0 0.6 0.5 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 4 4 2 Example esterified starch butadiene type stearate polyamide  6 1.5 copolymer 8.5 resin 0.6 0.6 0.5 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 4 3 2 Example esterified starch butadiene type stearate polyamide  7 1.5 copolymer 8.5 resin 0.3 0 0.5 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 4 2 3 Example esterified starch butadiene type stearate polyamide  8 1.5 copolymer 8.5 resin 0.3 1 0.5 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 3 2 3 Example esterified starch butadiene type stearate polyamide  9 1.5 copolymer 8.5 resin 0.3 0.6 0 Comparative 40 60 Phosphate Styrene- Acrylic Calcium Modified 4 4 2 Example esterified starch butadiene type stearate polyamide 10 1.5 copolymer 8.5 resin 0.3 0.6 1 Comparative 40 60 60 Phosphate Styrene- Acrylic Calcium Modified 5 2 3 Example esterified starch butadiene type stearate polyamide 11 1.5 copolymer 8.5 resin 0.3 0.6 0.5 Comparative 40 60 40 Phosphate Styrene- Acrylic Calcium Modified 3 2 3 Example esterified starch butadiene type stearate polyamide 12 1.5 copolymer 8.5 resin 0.3 0.6 0.5 Comparative 40 60 100 Phosphate Styrene- Acrylic Calcium Modified — — — Example esterified starch butadiene type stearate polyamide 13 1.5 copolymer 8.5 resin 0.3 0.6 0.5

[0076] <Printing Stain Resistance>

[0077] Using an inkjet printing press MR 20 MX-7000 manufactured by Miyakoshi Printing Machinery Co., a 6000 m evaluation image was printed with an aqueous pigment ink under the condition of a printing speed of 150 m/min. The image to be evaluated was 3 cm×3 cm square solid patterns recorded in a single continuous row with seven colors, namely, black, cyan, magenta, yellow, and superimposed colors (red, green, blue) created by a combination of two colors out of the above three color inks except black. Printing stains present in the printed portion were visually observed, and the printing stain resistance was evaluated according to the following criteria depending on the degree of visibility. In the present invention, if the evaluation is 3 to 5, it is assumed that the printing paper has printing stain resistance.

[0078] 5: No printing stain is recognized. Good.

[0079] 4: Printing stain is almost not recognized. Almost good.

[0080] 3: Printing stain is recognized slightly. However, there is no practical problem.

[0081] 2: Printing stain is recognized a little.

[0082] 1: Printing stain is recognized.

[0083] <Evaluation of Resistance to Color Density Unevenness>

[0084] Using an inkjet printing press MJP 20 MX-7000 manufactured by Miyakoshi Printing Machinery Co., a 6000 m evaluation image was printed with an aqueous pigment ink under the condition of a printing speed of 150 m/min. The image to be evaluated was 3 cm×3 cm square solid patterns recorded in a single continuous row with seven colors, namely, black, cyan, magenta, yellow, and superimposed colors (red, green, blue) created by a combination of two colors out of the above three color inks except black. The resistance to color density unevenness was evaluated based on the following criteria by visually observing the printed portion of each color solid portion image. In the present invention, if the evaluation is 3 to 5, it is assumed that the printing paper has resistance to color density unevenness.

[0085] 5: The color density is uniform.

[0086] 4: The color density is slightly non-uniform depending on the color.

[0087] 3: The color density is slightly non-uniform.

[0088] 2: The color density is partially non-uniform.

[0089] 1: The color density is non-uniform throughout the printed portion.

[0090] <Dullness Resistance>

[0091] Using an inkjet printing press MJP 20 MX-7000 manufactured by Miyakoshi Printing Machinery Co., a 6000 m evaluation image was printed with an aqueous pigment ink under the condition of a printing speed of 150 m/min. The image to be evaluated was 3 cm×3 cm square solid patterns recorded in a single continuous row with seven colors, namely, black, cyan, magenta, yellow, and superimposed colors (red, green, blue) created by a combination of two colors out of the above three color inks except black. The dullness resistance was evaluated according to the following criteria by visually observing a decrease in the saturation of each color in comparison with a standard color sample. In the present invention, if the evaluation is 3 to 5, it is assumed that the printing paper has dullness resistance.

[0092] 5: Good

[0093] 4: Generally good.

[0094] 3: Decrease in saturation is observed slightly. However, there is no practical problem.

[0095] 2: Decrease in saturation is observed a little.

[0096] 1: A decrease in saturation is observed.

[0097] The evaluation results are shown in Tables 1 and 2.

[0098] From Tables 1 and 2, it can be seen that Examples 1-26 corresponding to the present invention have printing stain resistance, resistance to color density unevenness and dullness resistance. On the other hand, it can be seen that Comparative Examples 1-12 which do not satisfy the constitution of the present invention cannot have these effects. In Comparative Example 13, blanket piling occurred for offset printing, and Comparative Example 13 was not a coated printing paper having suitability for an offset printing press.