JP2597916Y2 - Manufacturing method of magnetic recording medium - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated water-resistant sheet for one-sided offset printing which has excellent water resistance, printability, low chargeability, weather resistance and dimensional stability.

[0002]

2. Description of the Related Art Heretofore, in a printing paper in which a thermoplastic synthetic resin is laminated on a base material, an inorganic pigment such as calcium carbonate is contained in a synthetic resin layer to reduce the chargeability.

[0003]

In the above-mentioned conventional laminated sheet, the charging is suppressed to some extent by the effect of the inorganic pigment compounded in the synthetic resin layer. However, in order to prevent static electricity trouble on the printing press during the drying period, it is desirable to add an antistatic agent to the synthetic resin layer to further lower the chargeability. However, if the resin layer contains an antistatic agent, the hydrophilic surface of the antistatic agent will be present on the surface of the resin layer. Does not conform to the print surface, and the print finish is often impaired. Accordingly, an object of the present invention is to provide a laminated water-resistant sheet for single-sided offset printing in which the chargeability of a laminated sheet for single-sided offset printing is reduced without impairing printability and the like.

[0004]

According to the present invention, the object is to provide a single-sided offset printing sheet formed by laminating a thermoplastic synthetic resin on both sides of a substrate, and a surface specific resistance of a back side which is a non-printing side. Value is 1 × 1 at 60% relative humidity
A 0 ⁸ ~1 × 10 ¹² Ω, and the surface resistivity is achieved by a low chargeability of the single-side offset printing laminated waterproof sheet being smaller than the surface resistivity of the surface is printed surface be able to.

The antistatic agent used in the laminated waterproof sheet for single-sided offset printing according to the present invention includes, for example, an anionic, cationic or nonionic surfactant, and an inorganic conductive material represented by a metal oxide. And conductive resins. The antistatic treatment using these antistatic agents can be carried out by kneading or coating the outermost synthetic resin layer laminated on paper or plastic used as a base material. The blending amount of the antistatic agent is not generally discussed because the antistatic effect varies depending on the type and method of addition, but when viewed from the surface specific resistance value adjusted by the antistatic agent, 1 × 10 ⁶ to 1 × 10 ¹³ Ω, preferably 1 × 10 ⁸
To 1 × 10 ¹² Ω, and the printed surface is 1 × 10 ⁹ to 1 × 10 ¹⁷ even when the antistatic treatment is performed.
Ω, preferably 1 × 10 ¹² to 1 × 10 ¹⁴ Ω.

In the laminated sheet according to the present invention, an inorganic pigment may be contained in the thermoplastic synthetic resin layer. In this case, the average particle size of the inorganic pigment used is usually 0.01 to 10 μm from the viewpoint of the dispersibility of the inorganic pigment in the resin layer and the writeability and printability of the inorganic pigment imparted to the resin layer.
m, preferably 0.1 to 5 μm. Examples of the inorganic pigment that can be used include calcium carbonate, titanium oxide, talc, clay, kaolin, barium sulfate, calcium silicate, magnesium oxide, silicon oxide, diatomaceous earth, magnetic iron oxide, and the like, and mixtures thereof. .

According to the present invention, when incorporating an inorganic pigment into a synthetic resin layer, a small amount of an organic filler such as carbon black, a phenol resin, a melamine resin, and a urea resin may be mixed to further improve the dispersibility of the filler. As an auxiliary agent to be added, a fatty acid salt, a tackifier, a hydrophilized polyolefin wax, or the like can be appropriately added, and the surface treatment of the filler can be performed with them. The blending amount of the inorganic pigment is not particularly limited, but is preferably 20 to 80% by weight, more preferably 25 to 50% by weight.

As the base material constituting the laminated sheet of the present invention, for example, high quality paper, medium quality paper, coated paper and various synthetic resin films can be used. On the other hand, as the polyolefin-based thermoplastic resin forming the resin layer, an ethylene-based resin, a propylene-based resin, and a polyester-based resin are preferable.

Here, the olefin resin is ethylene,
Not limited to homopolymers of 1-olefins such as propylene, but also include copolymers containing small amounts of other monomers copolymerizable with 1-olefins, such as vinyl acetate, ethyl acrylate, methyl methacrylate, and the like. , And compositions of different polymers or copolymers.

[0010] As a method for manufacturing a laminated sheet of the present invention, a polyolefin resin layer containing no inorganic pigment is extruded on at least one surface of a base material layer from a T-die film forming machine, and an inorganic pigment-containing material is separately formed on the upper surface. A method in which the polyolefin resin layer is laminated and joined while being extruded from a T-die film forming machine is preferred. Here, the thickness of the resin layer is usually 3 μm or more, preferably 5 to 15 μm in the inorganic pigment-containing layer.

The outermost layer and the resin layer in contact with the substrate are made of the same material, for example, a combination of low-density ethylene resins, high-density ethylene resins, propylene polymers, and 1-butene polymers. It is preferred that
Even when these polymers are composed of a composition of two or more kinds of polymers, the composition of the constituent polymers of each layer and those having the same blending ratio between both layers are included.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a laminated waterproof sheet according to an embodiment of the present invention. For example, a high-quality paper is used as a base material (1), and a thermoplastic synthetic resin layer ( 2) is laminated, and on the other hand, the thermoplastic synthetic resin (3) is also laminated on the back surface side which is the non-printing surface. And in this invention, it is comprised so that the surface specific resistance value of the thermoplastic synthetic resin (3) of a non-printing surface side may become smaller than the thermoplastic synthetic resin layer (2) of a printing surface side. FIG. 2 is a cross-sectional view of a laminated water-resistant sheet according to another embodiment of the present invention, in which the thermoplastic resin layer on the surface side is composed of an intermediate layer (4) and an outermost layer (5), Similarly, the thermoplastic resin layer on the back side is also composed of two layers, an intermediate layer (6) and an outermost layer (7).

Examples 1 to 7 and Comparative Examples 1 to 4 Laminated sheets having the structures shown in Tables 1 to 3 were produced. The raw materials used are as follows. Fine paper ... Jujo Paper Co., Ltd., "Gold King" (basis weight 64 g / m ²⁾ PP ... Polypropylene (Mitsui Petrochemical Industries Co., Ltd. LA221) fillers ... calcium nonionic surfactant carbonate ... Kao Corporation EL320

The synthetic resin is laminated or extruded from a T-die, and while spraying ozone on the molten resin in contact with the base material layer, the laminated waterproof structure having various structures shown in Tables 1 to 3 is obtained. The sheet was manufactured, and the following physical properties were measured. The results are shown in Tables 1 to 3. The measurement physical properties and the measurement method are as follows.

[Measurement physical properties] [Measurement method] 1) Thickness: JIS P-8118 2) Surface specific resistance: 23 ° C. × 60% RH using Model P-601 VE-30 manufactured by Kawaguchi Electric Co., Ltd. 1 week after the production in the atmosphere described above. 3) Dynamic friction coefficient measurement: JIS P-8147 4) Printability: Roland offset lithographic printing press (202B) The size of the printing sheet is 297 x 420mm (A3), and the paper feeding speed is 8000 sheets / hour. The atmosphere was 20 ° C. × 40% RH. The ink used was TK-CCM-KS manufactured by Toyo Ink. 5) Measurement of surface potential on the printing press: Measurement was performed with a KSD6110 surface potential measuring device manufactured by Kasuga Electric Co., Ltd. in the paper feeding section on the printing press. 6) Printing workability (supply / discharge): ◎ 0 troubles per 2000 sheets ○ 1 trouble per 2000 sheets △ 2 troubles per 2000 sheets × 3 troubles per 2000 sheets or more 7) Finish of stamped surface: ○ Good × Uneven stamped surface Yes

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

[0020]

According to the present invention, as shown in Tables 1 to 3, troubles due to static electricity can be prevented without causing an adverse effect of the antistatic agent on the printed surface. In addition, since both surfaces are covered with the resin, a laminated sheet for single-sided offset printing having excellent water resistance, weather resistance and dimensional stability can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of a laminated waterproof sheet of the present invention.

FIG. 2 is a sectional view of another embodiment of the laminated waterproof sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base material 2 ... Synthetic resin layer 3 ... Synthetic resin layer 4 ... Intermediate layer 5 ... Outermost layer 6 ... Intermediate layer 7 ... Outermost layer

Continuing on the front page (72) Inventor Yuji Kohama 5-21-1, Oji, Kita-ku, Tokyo Jujo Paper Co., Ltd. Product Development Laboratory (72) Inventor Michio Takano 3rd Chigusa Kaigan, Ichihara-shi, Chiba Mitsui Oil Chemical Industry Incorporated (72) Inventor Takeshi Harada 3 Chigusa Coast, Ichihara-shi, Chiba Mitsui Oil Chemical Industry Co., Ltd. (56) References JP-A-62-259848 (JP, A) JP-A-3-61039 (JP, A)

Claims (4)

(57) [Scope of request for utility model registration] 1. A single-sided offset printing sheet in which a thermoplastic synthetic resin is laminated on both sides of a base material, wherein the non-printed surface has a surface specific resistance of 1 × 10 ⁸ to 1 at a relative humidity of 60%. A low-charging laminated water-resistant sheet for single-sided offset printing, characterized in that the surface resistivity is × 10 ¹² Ω and the surface specific resistance is smaller than the surface specific resistance of the surface which is the printing surface. 2. The laminated waterproof sheet according to claim 1, wherein both the front and back surfaces of the sheet are subjected to an antistatic treatment. 3. The antistatic treatment is performed using any one kind of antistatic agent selected from an anionic surfactant, a cationic surfactant, a nonionic surfactant, and a conductive resin. The laminated water-resistant sheet according to claim 2, wherein 4. The laminated waterproof sheet according to claim 1, wherein the thermoplastic synthetic resin is a polyolefin resin.