JPH0767789B2 - Print laminate film and print laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print laminate film and a print laminate, and more particularly to a print laminate film in which a biaxially oriented polypropylene resin layer and an adhesive resin layer are laminated. The present invention relates to a print laminate having the print laminate film laminated.

[Conventional technology]

For example, a print laminate obtained by laminating a resin film on printing paper is used for a cover for a book. The cover made of the print laminate is provided with gloss by the resin film.

[Problems to be Solved by the Invention]

The conventional print laminate is likely to curl to the laminate film side when heated. For this reason, in a book equipped with a book cover made of the conventional print laminate, the cover folded on the back side of the cover curls toward the side away from the display, and thus the cover is likely to be lifted even when the book is closed. Difficult to handle. Also, if the cover is forcibly closed, the cover may be bent.

An object of the first invention is to provide a print laminate film capable of curling a print laminate on the side of a base material layer such as printing paper.

An object of the second invention is to provide a print laminate using the print laminate film according to the first invention.

[Means for Solving the Problems]

The print laminate film according to the first invention is a laminate of a biaxially oriented polypropylene resin layer and an adhesive resin layer. This film is characterized in that the curl direction by heating is toward the adhesive resin layer side.

The polypropylene resin used for the biaxially stretched polypropylene resin layer is a homopolypropylene resin or a random copolymer resin of propylene and another olefin.

The homopolypropylene resin has an isotactic index (II) represented by the residual amount of boiling n-heptane extracted from 90 to 99% by weight, and an intrinsic viscosity [η] measured in tetralin according to ASTM-D1601. 1.0-4.0dl
/ g, more preferably 1.2 to 2.3 dl / g. Especially II is 9
6-98 wt% polypropylene, crystallization peak temperature is 110
Polypropylene having a temperature of not less than 0 ° C. and polypropylene having both the above properties are preferable.

Examples of the copolymer of propylene and olefin include copolymers of α-olefin such as ethylene, butene, and hexene with propylene. Particularly, those having an α-olefin content of 3 mol% or less are preferable.

In the case of the present invention, as the polypropylene resin,
It is preferable to use a homopolypropylene resin.

Known additives such as a crystal nucleating agent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, and an antiblocking agent may be added to the polypropylene resin used in the present invention.

Examples of the adhesive resin used in the adhesive resin layer include ethylene-vinyl acetate copolymer resins, ethylene-methyl methacrylate copolymer resins, and mixtures of these resins with petroleum resins, waxes, and the like. be able to. Among them, the adhesive resin used in the present invention has a melting point of 80 ° C.
The following are preferable, and those of 70 ° C. or lower are more preferable. When the melting point is higher than 80 ° C, the thermal adhesiveness of the laminate film deteriorates. Here, the melting point is a value measured using a differential scanning calorimeter (DSC). Specifically, the temperature of the sample resin is raised to 280 ° C at 20 ° C / min, held for 5 minutes, cooled at the same speed, and then raised again at the same speed. It is a value represented by the temperature at the apex of the melting peak with the large peak as the melting peak. The adhesive resin used is crystallized. When an adhesive resin that is easily crystallized is used, the adhesive resin layer is likely to shrink due to heating, and the curl direction of the laminate film due to heating tends to be toward the adhesive resin layer side.
Here, the adhesive resin that easily crystallizes refers to one having a main crystallization peak temperature of 65 ° C. or less. In particular, the adhesive resin is
Those having a main crystallization peak temperature of 45 ° C. or lower are preferable. The crystallization main peak temperature is a value measured using DSC. Specifically, the sample resin is 280 ℃ to 20 ℃ /
It is a value expressed by the temperature at the apex of the endothermic peak at that time when cooled at a temperature decrease rate of minutes.

The print laminated film of the present invention can be manufactured by using a method such as an extrusion laminating method or a coextrusion method. In the case of the extrusion laminating method, first, a biaxially stretched polypropylene resin film is produced from the above polypropylene resin. Then, the above-mentioned adhesive resin is extruded and laminated on the obtained film. In the case of the co-extrusion method, the above polypropylene-based resin and the adhesive resin are supplied to separate extruders to be extruded and laminated at a predetermined temperature, and a laminated film is produced by receiving the laminated resin on a cooling drum. . Then, the obtained laminated film is biaxially stretched.

In the print laminate film of the present invention, the biaxially oriented polypropylene resin layer preferably has a thickness of 10 to 30 μm.
The thickness of the adhesive resin layer is preferably 2 to 25 μm. When the thickness of the adhesive resin layer is less than 2 μm, the adhesiveness with the base material is insufficient and the effect of the present invention is difficult to obtain. vice versa,
When it exceeds 25 μm, no remarkable effect is obtained and the cost becomes high.

The print laminate film of the present invention preferably has a curl rate of 30% or less when heat-treated at 120 ° C. for 15 minutes. If the curl rate exceeds 30%, handling tends to be difficult.
Here, the curl rate means to prepare a sample film 1 having a length of l ₀ as shown in FIG. 1A and measure the length l ₁ when curled by heating as shown in FIG. 1B. , Is the value obtained by the following calculation formula.

Curl rate (%) = (l ₀ −l ₁ ) / l ₀ × 100 Further, in the print laminate film of the present invention, the surface roughness (R _a ) of the biaxially oriented polypropylene resin layer is 0.06 μm.
The following is preferable, and 0.04 μm or less is more preferable. R _a is
If it exceeds 0.06 μm, the gloss and transparency of the print laminate film deteriorate due to light scattering. Note that R _a
Is a value represented by the center line average roughness obtained at a cutoff of 0.25 mm based on JIS-B0601.

The print laminate film of the present invention is used as a laminate film for a book cover, for example, as described later.

*** The print laminate according to the second invention is a print laminate film in which a biaxially oriented polypropylene resin layer and an adhesive resin layer are laminated, and a base material laminated on the adhesive resin side. With layers. This print laminate is characterized in that the curl direction due to heating is toward the base material layer.

An example of the print laminate according to the present invention is shown in FIG. 2A. In the figure, a print laminate 10 is shown with a base layer 11
And a print laminate film 12 are laminated. The base material layer 11 is a printing paper, and the printing layer 11b is provided in a predetermined pattern on the base material paper 11a. The print laminate film 12 is the print laminate film according to the first invention, which comprises a biaxially oriented polypropylene resin layer 12a and an adhesive resin layer 12b. The print laminate 10 is manufactured by arranging the adhesive resin layer 12b side of the print laminate film 12 on the print layer 11b of the base material layer 11 and thermocompressing the both.

The print laminate 10 is used as a cover 21 of a book 20, for example, as shown in FIG. Cover 21
Since the print laminate film 12 according to the first aspect of the invention is provided as described above, it curls toward the base material layer 11 side by heating as shown in FIG. 2B. Therefore, the folded portion 21a of the cover 21 is curled toward the cover 20a side of the book 20. Therefore, the cover 21 using the print laminate 10 of the present invention is easy to handle and is unlikely to bend when the cover 20a is closed.

〔The invention's effect〕

The print laminate film according to the first invention is characterized in that the curl direction by heating is toward the adhesive resin layer. Therefore, according to the first aspect of the invention, it is possible to realize a print laminate film capable of curling the print laminate on the substrate side.

A print laminate according to the second invention comprises the above print laminate film. Therefore, the second
According to the invention of (1), it is possible to realize a print laminate that curls on the base material layer side.

〔Example〕

Example 1 A print laminate film was produced by extruding and laminating an adhesive resin on one side of a biaxially stretched polypropylene resin film. A mixture of ethylene-vinyl acetate copolymer resin, petroleum resin, and wax was used as the adhesive resin. The melting point of the adhesive resin was 65 ° C, and the crystallization temperature was 45 ° C.

The print laminate film of this example has a temperature of 120 ° C.
When heated for a minute, it curled toward the adhesive resin layer and the curl rate was 23%.

Furthermore, the obtained print laminate film was heated at 120 ° C.
When it was pasted onto the printing paper by thermocompression bonding, a print laminate curled on the printing paper side and easy to handle was obtained.

Example 2 As an adhesive resin, an ethylene-methyl methacrylate copolymer resin having a melting point of 75 ° C. and a crystallization temperature of 58 ° C. was used, and Example 1 was used.
A print laminate film similar to the above was produced.

The obtained print laminate film also curled toward the adhesive resin layer, and the curl rate was 13%.

When a print laminate similar to that of Example 1 was produced from the obtained print laminate film, a print laminate curling on the printing paper side and easy to handle was obtained.

Comparative Example Using the ethylene-vinyl acetate copolymer resin having a melting point of 95 ° C. and a crystallization temperature of 80 ° C. as an adhesive resin, the same print laminate film as in Example 1 was manufactured.

The obtained print laminate film curled on the biaxially oriented polypropylene film side, and the curl rate was 3%.

A print laminate similar to that of Example 1 was manufactured using the obtained print laminate film, but the print laminate was curl to the print laminate film side and was difficult to handle.

[Brief description of drawings]

FIG. 1A and FIG. 1B are schematic views showing the curl rate measuring method in the first invention, FIG. 2A is a vertical cross-sectional partial view of an example of the second invention, and FIG. 2B is a vertical cross-section during the curl. Partial view and FIG. 3 are perspective views when the second invention is applied to a book cover. 10 …… Print laminate, 11 …… Base material layer, 12 …… Print laminate film, 12a …… Biaxially oriented polypropylene resin layer, 12b …… Adhesive resin layer.

Claims (2)

[Claims] 1. A print laminate film in which a biaxially stretched polypropylene resin layer and an adhesive resin layer are laminated, wherein the curl direction by heating is the adhesive resin layer side. 2. A print laminate film in which a biaxially oriented polypropylene resin layer and an adhesive resin layer are laminated,
A print laminate having a base material layer laminated on the adhesive resin layer side, wherein the curl direction by heating is the base material layer side.