JPS5846198A - Multi-layered coated paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing multilayer pigment-coated paper or paperboard that has good printing gloss, ink setting properties, and quick drying.

Traditionally, Shidasol Coat or Multi-stage Coating Expansion - Lid-type =-Turf 2 to 3 times, or P-Router Coating and then Air Knife Coater Coating, or P-Router Coating and then F-Ray P Coater Coating, etc., is performed by combining different types of coaters.

Furthermore, to achieve high-speed and efficient coating, instead of the air knife single route, the I-solute method has been implemented in which a roll coater is used for undercoating and a blade coater is used for topcoating, but even then, the air knife single coat is still effective. It cannot be said that it is superior in quality compared to.

Another purpose of the I-sol coat is to compensate for defects in the base paper, such as smoothing out irregularities in the base paper and improving smoothness.

In other words, the current multi-stage coating is simply a matter of efficiency or correcting defects in the original paper, depending on the special circumstances of each factory. Treated paper inevitably suffers from a decrease in printing gloss, especially when the amount of coating is small.

The present invention solves this problem - ITo1) A detailed study of the combination of properties of the undercoat paint and the topcoat paint,
After undercoating, an alkaline agent is added so that the - of the coating layer is 8.6 or more, preferably 8.8 or more and 9.8 or less, and after overcoating, an alkali agent is added so that the - of the coating layer is 8 or less, preferably 7. .3-7.
By adjusting the coating liquid so as to give a coating liquid of 7, a pigment-coated paper with good printing gloss and good setting properties was obtained.

Formation of a uniform ink film should produce a stamp surface with good gloss, which is achieved by uniform absorption of the ink vehicle into the coating layer and sufficiently uniform set retention in the film.

On the other hand, depending on the multi-stage coating, the ink vehicle absorption becomes better than the single coating, and the print gloss tends to decrease. On the other hand, if an alkali is added to the paint in single coating, the absorption of ink vehicle will be suppressed and the printing gloss will be reduced, but the setting property will deteriorate.

Based on the above facts, it has been realized that it is possible to improve the surface area by including an alkali in the undercoat layer to suppress the absorption of ink vehicle, and by providing a topcoat layer with a dry weight of δ to 16 mm.

In the present invention, the pigments used in the coating layer include clay, kaolin, and aluminum hydroxide. Common pigments for coated paper include precipitated calcium carbonate, heavy carbon calcium, titanium oxide, sulfuric acid/sulfuric acid, zinc oxide, and plastic fragments. In addition, as the adhesive that forms the coating layer together with the pigment, styrene-butadiene copolymer,
Conjugated citric polymer latex such as methyl methacrylate/butadiene copolymer, acrylic polymer latex such as heavy metal body or copolymer of acrylic acid ester and/or methacrylic acid ester, ethylene/♂yl acetate copolymer, etc. f-nyl-based polymer latex, or functional group-modified polymer latex with monomers containing functional groups such as carxyl groups of various heavy metals, /9N nyl alcohol, olefin/masiic anhydride resin, metsene resin, etc. Synthetic resin adhesives, starches such as positive starch, oxidized starch, force A-
Adhesives for coated papers such as cellulose derivatives such as -xymethylcellulose, hyproxyethylcellulose, proteins such as protein extracted from single cell assimilated materials such as soybean protein, methanol, acetic acid, etc. are used alone or in combination.

In addition, various auxiliary agents such as an antifoaming agent, a coloring agent, and a flow modifier may also be used as appropriate.

In the present invention, the undercoat coating liquid is a blade coater, an air knife coater, an o-ru, a brush coater, a curtain coater, a champlex coater, a nono-coater, etc., which are commonly used in the production of coated paper. Gutu-
The base paper is coated in one layer or in multiple layers using an on-machine or off-machine coater equipped with a coating device such as an acoater or a size coater. The method for forming the top coat layer formed on the undercoat 9 coat layer is not particularly limited, and the above-mentioned coating apparatus can be used.

The coating layer referred to in the present invention is measured as follows. That is, the first step is to remove the - of the surface of the coated paper.

Second step: Next, the surface of the 100-0 coating layer of the coated paper is scraped to a uniform thickness of 20 mp using a suitable machine or tool, such as a force-sled blade. - of
The eighth step is the surface 1 of the different coated papers of the Sansol.
The surface layer of 00- is measured in the same way as 4-way, and the - of the surface after oystering and 9-way is measured using a hydrogen ion concentration colorimeter.

Do the above operations until the cardboard layer appears? Measure the return. - of the surface layer is 8.0 or less, and - of the other layer is
That is, if any of the measurements at each time is a゛δ6 or more, it is within the scope of the present invention.

The present invention will be explained in more detail below with reference to Examples, but it is of course not limited thereto.

Examples 1-6 Comparative Examples 1-3 Secondary kaolin (tntra cot
e) to 100 parts as a dispersant and di-tetraphosphoric acid 10.1
Make a slurry with an electric kina, add 6 parts of phosphoric acid ester starch (M84600) and BB9ft.
Add 12 parts of Yux (J11R0695) and prepare the solution (
1. Add each alkali to this and the coating layer after coating is 8 to 1.
Make it about 0. Coating is done using tabletop blade coater 1
8 coated, and tabletop air knife coater 1-grade kaolin (tntra White 90) 100
10 parts of oxidized starch, 12 parts of 8B latex.
Coating was performed from 11/l to 209y, and gloss was applied using a suit calender.

White paper gloss, printing gloss, ink set, and
The measurement results for the printed surface strength are also listed in Table 1.

As is clear from the results in Table 1, each Example 1 of the present invention
9. Printing gloss was higher than that of the comparative example.

-White paper gloss is GIO1551Meter GM-2
6D (manufactured by Murakami Color Research Institute) at an incident angle of 75 degrees f.

h Printing gloss was measured using R1 printing tester (manufactured by Mei Seisakusho).
Ink is Sup@r Apex (manufactured by Dainippon Ink ■)
Gloss M@t@rGM-
26D at an incident angle of 60 degrees.

C. The ink set used was an RI printing tester (manufactured by Mei Seisakusho) to determine the ink transferability of the printing reversal paper. The evaluation criteria were determined to be worse in the order of ○■△Δ×.

d. Printing surface strength was determined by printing 1 IPI ink using an RI printing tester (manufactured by Mei Seisakusho) and determining surface peeling.9.

The evaluation standard was that JIK of ○@Δmu× becomes worse.

e, - of the ayan layer was determined using a hydrogen ion concentration (-) colorimeter.

Claims (3)

[Claims] (1) After applying an undercoat mainly consisting of pigments and adhesives to the base paper, a topcoat is further applied and dried, and on nine-coated paper, the - of the multiple layers of the undercoat is 8.6 or more, or - of the two topcoats. 8.0
A multilayer coated paper characterized by the following: (2) The multilayer coated paper according to claim 1, wherein - of the coated paper is 7.3 to 7.71. (3) The multilayer coated paper according to claim 1 or 2, wherein - of the undercoat layer is &8 to 9.81.