JP2565955B2 - Method for manufacturing off-wheel coated base paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention applies a size press solution, which is mainly an etherified starch paste solution, to maintain the air permeability of the base paper and streak during coater application. The present invention also relates to a method for producing an off-wheel coated base paper, which is characterized in that

(B) Conventional Technology As a conventional manufacturing method for such an off-wheel coated base paper, a size press liquid containing 10% or less of oxidized starch paste liquid is mainly used by a size press of two rolls for the purpose of improving the blister resistance. I was smearing.

In addition, the transfer type roll coater method transfers the paste solution on the roll and finally smears it on the paper,
A sufficient viscosity was required for the paste solution, and a high-concentration starch paste solution and a color mainly mixed with a pigment and a binder were smeared.

Also, as shown in Japanese Patent Publication No. 60-39799, a method of using PVA as a substitute for starch has been proposed.

(C) Problems to be Solved by the Invention However, the conventionally known two-roll size press system, in which a size press liquid mainly containing 10% or less of oxidized starch paste liquid is smeared, is used. Although the blister resistance is improved because it penetrates into the inside, the load of the after-dryer after the size press process is increased and a large amount of steam is required.

Further, the transfer roll coater method has a high concentration of oxidized starch paste liquid to be smeared, so the drying load of the after-dryer is good, but the air permeability of the base paper deteriorates due to the film formation on the paper layer surface by starch. I will end up. This tendency becomes more remarkable when PVA is used. Furthermore, the high film-forming property also impedes the permeation of the starch paste solution into the paper, and therefore no increase in the number of binding points in the paper is observed. No improvement in strength can be expected. As a result, it has been difficult to give the coated base paper obtained by the transfer type roll coater method the blister resistance which is a characteristic of the off-wheel coated base paper.

Also, from the point of view of dry load only, the NSP method that does not smear in the size press process is the best, but since this method does not control the surface at all, the streak phenomenon during coater smearing, Problems such as reduction of surface strength are likely to occur.

(D) Means for Solving the Problems The present inventors need to use the size press method from the viewpoint of reducing the load on the after-dryer and suitability for streak in the coater. As a result of intensive research to improve the drawbacks, the size press liquid obtained mainly from a certain type of processed starch has a viscosity comparable to that of the high-concentration oxidized starch conventionally used even at a low concentration, and more than that. By having excellent air permeability, and by combining it with neutral papermaking, the off-wheel coat, which is extremely unique and unprecedented, does not impair blister resistance within the range where these properties are retained. The inventors have found that a base paper can be obtained and have reached the present invention.

As the raw material of the processed starch used in the present invention, general-purpose starch such as potato starch, tapioca starch, and corn starch can be used. Furthermore, as a processing method,
Carboxyalkyl etherification, hydroxyalkyl etherification, etc. have been carried out, but the type is not selected. However, it is generally preferred to use a hydroxyalkyl etherified potato-based starch for use as a size press starch.

Further, the starch used in the present invention has a Brookfield viscosity (LVE type) of 3% paste at 30 ° C. at a shear rate of 60 rpm of 10 m.
-Pa or more, but preferably 15 to 100 m-Pa is suitable because the starch paste liquid transferability in a transfer type roll coater is further improved.

Furthermore, Hercules type high shear viscosity (4400rp
m, A bob) is preferably 9 to 25 m · Pa. Also,
In the present invention, it is better that the amount of the processed starch to be smeared is smaller, and the maximum amount is 3.0 g / m ² , preferably 0.5 g / m ² or less. To improve blister resistance, increase internal bond strength,
It is also necessary to improve the air permeability, but it is appropriate that the base paper smeared with the modified starch according to the present invention has an air permeability of 350 mmHg or more.

The base paper used in the present invention may be any kind of paper that can be made using a normal paper machine, but it is made by neutral papermaking having a papermaking pH of 7 or higher according to JIS P-8133. The blister resistance is further improved by combining it with paper.

Regarding the filler in the paper, talc, light calcium carbonate, heavy calcium carbonate, titanium dioxide, etc. in neutral papermaking,
Kaolin, clay, talc, etc. are used in acidic papermaking, but the type is not selected.

Furthermore, general-purpose synthetic paper strength agents such as polyacrylic amide can be added to the paper.

Further, as a method for smearing the size press liquid in carrying out the present invention, a size press coat, a bill blade coat, a calendar stack coat, a roll coat, or the like, which is a conventionally known surface size of being smeared on the surface of the paper and then dried. Although any method can be adopted, a method using a transfer type roll coater is particularly preferable from the viewpoint of controlling the amount of processed starch deposited and reducing the drying load.

(E) Example Comparative Example 1 Oxidized starch (Nippon Shokuhin Kako MS-3800), which is generally used as a size press starch for GRC, was cooked at a 14% concentration, and the Hercules viscosity (4400 rpm, A bo
b) and B viscosity were measured.

In addition, using this 60 ° C paste solution, the amount of solids deposited on both sides of 140 g / m ² unsized press base paper becomes ² g / m ² ,
Application was performed using a size press coater. After drying this size press paper, it was allowed to stand for 48 hours under the conditions of a temperature of 20 ° C. and a relative humidity of 65%, and the air permeability was measured.

Further, after coating layers were provided on the front and back of this size press paper, solid printing was performed on both sides by RI printing machine and left for 48 hours under the same conditions as above. Then, when this coated paper was dried by direct heating (about 300 ° C.), it was checked whether or not fire blister occurred. The results are shown in Table 1.

Comparative Example 2 A size press was performed in the same manner as in Comparative Example 1 except that a 3% aqueous solution of polyvinyl alcohol (Nippon Gosei Kagaku Kogyo, Gohsenal T-330H) was used.

Comparative Example 3 A size press was carried out in the same manner as in Comparative Example 1 except that 3% sizing liquid of acetylated potato starch (LERF37, Oji National) was used.

Comparative Example 4 Cationized corn starch (Gato Size, Oji National)
Size pressing was performed in the same manner as in Comparative Example 1 except that the 50% 3% glue solution was used.

Comparative Example 5 A size press was carried out in the same manner as in Comparative Example 1 except that a 3% sizing solution of a quaternary medium-grade cationic starch (Perfectamyl PW, manufactured by Abebe Co., Ltd.) was used.

Example 1 Bidoxyetherified potato starch (Avebe, Solvic
A size press was performed in the same manner as in Comparative Example 1 except that 3% paste solution of ote 100) was used.

Example 2 High-viscosity hydroxyetherified potato starch (Abebe Co.,
A size press was performed in the same manner as in Comparative Example 1 except that 3% paste solution of Solvicote 200) was used.

(F) Effects of the Invention The off-wheel coated base paper according to the present invention is manufactured as described above, but the paper has a high air permeability because the etherified starch is smeared uniformly on the paper. Paper with high blister resistance can be obtained.

Further, according to the present invention, the etherified starch can be applied with a low-concentration paste solution so that the amount of smear can be easily controlled, and a transfer type roll coater having a good drying property can be used. Therefore, it is possible to easily and economically manufacture the off-wheel coated base paper without changing the conventional equipment.

Claims (1)

(57) [Claims] 1. An off-wheel having an air permeability of 350 mHg or more obtained by sizing a paper with a size press liquid mainly composed of etherified starch paste liquid so that the amount of adhered starch is 3 g / m ² or less. Manufacturing method of coated base paper.