JPS6147894A - Metal vapor deposited 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 (Industrial Application Field) The present invention relates to metallized paper, and more particularly to metallized paper with improved gloss, which is based on uncoated paper.

(Prior Art) Metal foil laminated paper, especially aluminum foil laminated paper, has been widely used as packaging materials and label paper. However, in recent years, so-called metal-deposited paper, in which sialuminum is deposited on aluminum foil-laminated paper, has come into use. Metal-metalized paper uses much less aluminum than aluminum foil-laminated paper, and has good recovery properties even when bent.Also, because the aluminum layer is very thin, the characteristics of paper are utilized, making it suitable for printing, etc. It has excellent workability, and since there is no plastic deformation like aluminum foil, the surface is less prone to scratches. Metalized paper is widely used for packaging materials, labels, etc., taking advantage of these advantages and metallic luster.

Metal-metalized paper can be produced by directly vapor-depositing metal onto the base paper, but when producing metal-metalized paper with a smooth surface and metallic luster, resin is deposited on top of the base paper. A common method is to provide a layer and deposit a metal onto this so-called undercoat layer. The purpose of this adder/der coat layer is to smooth the surface of the base paper, increase the gloss of the deposited film, improve the adhesion between the paper and the aluminum film, and suppress the release of moisture and gas from the abrasive during deposition. Established in Therefore, various types of metallized paper having an undercoat layer have been considered (for example, JP-A-57-134556, JP-A-5
7-149344, JP 58-126393, JP 11f858-211447, JP 59-929
(No. 8, etc.), and the undercoating agents include water-based and solvent-based ones.

(Problem to be solved by the invention) However, simply applying a water-based undercoat agent makes it difficult to produce a metallic luster on the surface, and in some cases, a large amount of coating is required to produce the luster, which tends to cause curling. However, it has not been widely used due to some reasons.

On the other hand, solvent yarn a/goo coating agents have strong permeability into the base paper during coating, and when applied to uncoated paper such as high-quality paper, a good metallic luster cannot be obtained unless a large amount of undercoat agent is applied. . Therefore, it is common to use coated paper as the base paper, but coated paper requires an extra step of coating and one step of carrying and coating compared to uncoated paper, resulting in higher costs. In addition, in both cases, the proportion of the clay coat layer and undercoat layer in the entire metallized paper increases,
The paper's inherent stiffness and flexibility are impaired, the difference between the front and back sides becomes large, and curling tends to occur, which impairs the paper's suitability for work.

Therefore, it was considered to apply a water-based undercoat agent and a solvent-based undercoat layer to uncoated paper, but in this case, the adhesion between the water-based and solvent-based undercoat layers was poor, and it was difficult to use metals for practical purposes. It was not possible to obtain metallized paper.

In order to solve these problems, the present inventors conducted extensive research and found that using a rubber-based resin with a glass transition point within a specific range as an aqueous undercoat agent eliminates the above-mentioned drawbacks including glossiness and adhesion. We have discovered that it is possible to do this, and based on this knowledge, we have accomplished the present invention.

(Another means to solve the problem) That is, a coating layer formed by coating and drying an aqueous dispersion of a rubber-based resin having a glass transition point in the range of 120 to 20°C on at least one surface of the mineral-based paper of the present invention; The present invention relates to metal-deposited paper in which metal-deposited layers are sequentially formed. The present invention also relates to a metal-deposited paper in which a coating layer formed by coating and drying the aqueous dispersion of the rubber-based resin, a coating layer formed by coating and drying a solvent-based resin, and a metal vapor-deposited layer are sequentially formed.

The force transition point is a temperature unique to polymeric substances with a sufficiently high molecular weight, and is the temperature at which the state changes from a glass-like hard state to a rubber-like state, depending on the monomer composition of the polymer, the degree of carboxyl modification, and the plasticizer. It changes depending on the amount used, etc.

The present inventors focused on the glass transition point of the rubber-based resin to determine the gloss of the surface when an aqueous dispersion of a rubber-based resin is coated on a base paper and dried, and then a metal is vacuum-deposited thereon. The present invention was completed by discovering that good surface gloss can be obtained only by using a rubber-based resin having a transition point.

The aqueous dispersion of the rubber resin according to the present invention may be a copolymer of two or three of styrene, butadiene, acrylonitrile, acrylic ester, methacrylic ester, ethylene, propylene, or further acrylic acid. It is an aqueous dispersion of a carboxyl-modified polymer using methacrylic acid, chloro/acid, maleic acid, etc.

The dispersion has a polymer as a discontinuous phase and water as a continuous phase, and is generally in a form called a polymer emulsion, polymer latex, etc. The rubber resin used in the present invention has a glass transition point. 120
It is limited to those within the range of ~20°C.

When the metallized paper of the present invention consists of a base paper, a layer formed by coating and drying an aqueous dispersion of a rubber-based resin, and a metallized layer, the rubber-based resin whose glass transition point is higher than 20°C is coated. Due to insufficient leveling of the layers, the gloss of the metallized paper becomes matte, resulting in poor adhesion to the base paper. As the glass transition point decreases, the leveling of the coating layer improves and the gloss of the metallized paper also improves. However, the glass transition point is -206C
Below this, the coating layer becomes sticky to the touch. If such tackiness occurs, the papers will stick together when they are rolled up during manufacture, resulting in a serious defect. Furthermore, the adhesion to the base paper also tends to be weak.

Coating of an aqueous dispersion of a rubber-based resin with a glass transition point in the range of 120 to 20°G onto a base paper can be performed using a roll method, an air knife coater method, a percoater method, a blade coater method, or a spray method. It can be applied uniformly and continuously by a known method such as the method.

The solid content of the aqueous dispersion on the base paper is 1 to 20 J.
il 7 m2, preferably 5 to 1597 m''. The aqueous dispersion coated on the base paper is dried at a temperature equal to or higher than the film forming temperature of the dispersion.

Although drying conditions are influenced by the particle size and concentration of the aqueous dispersion, drying is generally carried out at 100° C. or higher for several seconds to several minutes.

If you want to obtain a metal-deposited paper with even higher gloss, you can apply a solvent-based resin on top of the coated layer formed by coating and drying an aqueous dispersion of a rubber-based resin with a glass transition point of -20 to 20°C. It is possible to obtain highly glossy metal-deposited paper by providing a dry coating layer and forming a metal-deposited layer thereon by vacuum deposition. The glass transition point of rubber resin is 12
If the temperature is lower than 0°C or higher than 20°C, in addition to the above-mentioned drawbacks, the adhesion between the rubber resin layer and the solvent resin layer decreases.

The solvent-based resin used in the present invention is a solvent-based resin generally used for the undercoat of metallized paper, and has excellent adhesion to the coating layer formed by coating and drying an aqueous dispersion of rubber-based resin, and is vacuum-deposited. There are no particular restrictions on the resin as long as it has good gloss afterward, and various resins including melamine alkyd resins, alkyd resins, epoxy resins, urethane resins, acrylic resins, and chlorine/vinyl acetate resins can be used. The solvent-based resin is placed on the rubber-based resin layer as a solid content of 1 to 1597 m
2 preferably 3-10,! i'/m2 is applied and dried to form a resin layer. Drying requires a temperature necessary to evaporate the solvent and a temperature higher than the film forming temperature, and is carried out at 80 to 150°C for several seconds to several minutes. Metal evaporation is 10-2 to l 0-
This is done by heating the metal to be deposited above its melting point in a vacuum of 5 Torr to generate J atoms and/or polymers, which are then deposited on the coating layer. , zinc, gold, silver,
Copper and other alloys can be used, but aluminum is particularly suitable. These vapor depositions are performed using a known batch vapor deposition machine, semi-continuous vapor deposition machine, or continuous vapor deposition machine. After metal vapor deposition, depending on the purpose of packaging, printing, etc., it can be used as is or after being overcoated for the purpose of imparting printability, improving surface strength, and coloring to improve weather resistance.

The base paper used in the present invention is limited to uncoated paper and clear coated paper. This is not preferred because the properties of coated paper are impaired.

(Example) The effects of the present invention will be explained using examples, but the present invention is not limited thereto.Example 1 One side of high-quality imitation paper (meter tsubo i509/m2) Stere/-acrylic resin aqueous dispersion (Polysol AP-2675E, Showa Kobunshi Co., Ltd.) at 7°C
Coated with a solid content of 8 g/m'' (concentration 45% by weight) using a bar coater, dried for 30 seconds in a blow dryer at 110°C, and coated with aluminum to a thickness of approximately 50 nm in a vacuum of 2 x 10-' Torr. It was vapor-deposited.

The surface gloss of the metallized paper thus obtained and the adhesion between the rubber-based resin layer and the solvent-based resin layer were examined. -3M type (measured using Mura and Color Research Pfr&ri).

Adhesion was determined visually by attaching cellophane tape to the aluminum layer and then peeling off the cellophane tape.

After coating and drying the rubber-based rIEI fat, the surface of the resin layer was touched with a finger to check the tackiness to the touch.

The results are shown in Table 1.

Examples 2 to 6 In place of the rubber-based fat aqueous dispersion with a glass transition point of 7°C used in Example 1, a glass transition point of 5°C and 110°C was used.
Styrene acrylic resin aqueous dispersion (Polysol AP-2679 and Polysol 8F-2694, both manufactured by Showa Kobunshi Co., Ltd.), glass transition point -7°0117°
C styrene/-butadiene resin aqueous dispersion (2Tuxter 7310 and Luxstar 3307B, both manufactured by Dainippon I/K Industries Co., Ltd.), glass transition point 12 °C
Styrene-butadiene-acrylic resin aqueous dispersion (
Luckstar KS-1, Dainippon Ink & Chemicals Co., Ltd.!
The test was carried out in the same manner as in Example 1, except that the solid content of 8177 m2 was applied using a bar coater, and Examples 2 to 6 were obtained, respectively. The results are shown in Table 1. , Comparative Examples 1 to 5 Instead of using the rubber-based resin aqueous dispersion with a glass transition point of 7°C used in the examples, dispersions with glass transition points of -54°C and -30°C were used.
, 25°C styrene/acrylic resin aqueous dispersion (Polysol AP-610, Polysol AP-619, Polysol AP-2666, all manufactured by Showa Kobunshi Co., Ltd.), glass transition point 26°C, 61°C Stere/-butadiene resin aqueous dispersion (each Luckstar DS-20
4. The same procedure as in Example 1 was conducted except that Luxturf 132C (both manufactured by Dainippon Ink and Chemicals Co., Ltd.) was used. The results are shown in Table 1.

Example 7 A stereo/-acrylic resin aqueous dispersion having a glass transition point of 7° C. was coated and dried in the same manner as in Example 1, and then a solvent-based undercoat agent (MCA-4021, manufactured by Dainippon Ink and Chemicals Co., Ltd.) was applied. ) to solid content 3. ! After coating with an "i'/m" gravure coater, it was dried for 30 seconds in a blow dryer at 140°C, and then aluminum was vapor-deposited in the same manner as in Example 1. The results are shown in Table 2.

Example 8 The styrene/-acrylic resin aqueous dispersion with a glass transition point of 7°C in Example 7 was coated with a solid content of 81/m2.
The same procedure as in Example 7 was carried out except that 7 m" was applied. The results are shown in Table 2.

Comparative Example 6 One side of high-quality paper (meter tsubo i: 5011/m") was coated with clay (coating fk141/n2). A solvent-based undercoating agent was applied to the clay coated side of the single-sided coated paper in the same manner as in Example 7. Example 7
Drying and vapor deposition were performed in the same manner. The results are shown in Table 2.

Table 2 (Effects of the Invention) The metallized paper produced according to the present invention has excellent metallic luster on the surface, and excellent adhesion between the metallized film and the resin layer, between the resin layers, or between the W fat layer and the base paper.

Also, since there is no filler coat layer or thick undercoat layer,
The rI during printing, post-processing, and use without damaging the paper properties:
Excellent workmanship. Therefore, it is suitable for various packaging materials, labels, etc.

Claims (2)

[Claims] (1) At least one surface of the base paper has a glass transition point of -20
A metal-deposited paper formed by sequentially forming a coating layer formed by coating and drying an aqueous dispersion of a rubber-based resin in the range of .degree. C. to 20.degree. C. and a metal-deposited layer. (2) At least one surface of the base paper has a glass transition point of −20
A metal-deposited paper formed by sequentially forming a coating layer formed by coating and drying an aqueous dispersion of a rubber-based resin in the range of .degree. C. to 20.degree. C., a coating layer formed by coating and drying a solvent-based resin, and a metal-deposited layer.