JP3139830B2 - Print laminating film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print laminating film to be attached to a printing surface such as printing paper.

[0002]

2. Description of the Related Art Conventionally, print laminating is a method for laminating a plastic film and printing paper by thermocompression bonding without using an adhesive, in view of environmental pollution and hygiene caused by a solvent of the adhesive. Film is used.

[0003] As one method of producing such a film for print lamination, a biaxially stretched film or the like is formed in advance, and then a resin having thermal adhesiveness is melt-extruded on at least one surface of the film in a separate step. There are an outline method and an inline method for laminating.

[0004]

However, such a film for print lamination has surface glossiness in terms of performance,
Laminate strength, thin film properties, etc. were inferior and expensive.

[0005] In view of the current situation, the present inventors have reduced the number of steps and are easy to work by forming a film having a layer containing a petroleum resin in, for example, an in-line method, that is, in one step. Gloss, lamination strength,
The present inventors have conducted intensive studies to provide a print laminating film having excellent thin film properties and the like, and as a result, have reached the present invention.

[0006]

According to the present invention, at least one surface of a surface resin layer A made of a polypropylene resin containing a petroleum resin (hereinafter, simply referred to as a resin layer A) contains at least 25% by weight of a polyolefin resin. The present invention relates to a print laminating film formed by laminating adhesive layers B to be printed. Two

The polypropylene resin of the resin layer A according to the present invention includes a polypropylene homopolymer having a boiling n-heptane extraction residue of 90% or more and a propylene-α-olefin copolymer having an α-olefin content of 5 mol% or less. Examples thereof include a mixture of a propylene homopolymer and a propylene-α-olefin copolymer having a combined propylene content of 95 mol% or more, and a so-called homopolypropylene resin. There is no particular limitation. However, the polypropylene resin used for the resin layer A needs to have a higher melting point than the polyolefin resin used for the adhesive layer B.

The petroleum resin according to the present invention includes an aliphatic petroleum resin, a hydrogenated petroleum resin, an aromatic petroleum resin and the like, and is not particularly limited, but has an average molecular weight of 1,200 to 2,2.
Preferred are those having about 000, a softening temperature of 80 to 140 ° C. and an iodine value of about 20 to 150. At this time, it is needless to say that the present invention is not limited to the above numerical value range, but may be a petroleum resin having a numerical value outside this range.

[0009] The content of the petroleum resin is not particularly limited,
1 to 60 with respect to 100 parts by weight of the polypropylene resin
It is desirable to add parts by weight. If the amount is less than 1 part by weight, the film surface becomes rough, or the desired luster or the like cannot be obtained even when laminated with paper or the like. Transparency, glossiness, laminate strength, and the like tend to decrease, which is often undesirable.

The polyolefin resin used as the adhesive layer B is a polypropylene resin, a mixture of a polypropylene resin with a polyethylene resin, a polybutene-1 resin, a polybutadiene resin or the like, or a propylene resin.
Ethylene random copolymer, ethylene propylene
Grafting compounds having polar groups such as block copolymers, ethylene / propylene / butene terpolymer, propylene / ethylene / gen terpolymer, ethylene / vinyl acetate copolymer, maleic acid and maleic anhydride Copolymers such as a polymerized modified polyolefin copolymer and those obtained by mixing these copolymers with a polypropylene resin can be exemplified. Preferred examples thereof include ethylene-vinyl acetate copolymers (vinyl acetate content, for example, (5 to 30% by weight) and an ethylene / propylene / block copolymer are desirable, but it is a matter of course that the invention is not limited to this. In short, a polyolefin resin alone, a polyolefin resin mixture, or a mixture of a polyolefin resin and another polymer can be exemplified. At this time, it is necessary that the adhesive layer B contains at least 25% by weight, preferably more than 50% by weight of a polyolefin-based resin. Polymer (for example, a copolymer of nylon 6 and nylon 12), vinyl chloride-based copolymer (for example, ethylene-vinyl chloride copolymer, vinyl acetate
Vinyl chloride copolymer), polyester polymers and the like. The mixing amount of such another polymer is not more than 75% by weight, preferably less than 50% by weight. When the content of the polyolefin resin is 25% by weight or less, transparency, surface glossiness and the like are lowered, and it is often unfavorable as a film for print lamination. The purpose of adding another polymer is to improve the lubricity between the film and the roller during film formation, prevent the contact layer B from winding around the roller, and improve the lubricity between the surface of the resin layer A and the surface of the adhesive layer B. Prevention of wrinkles during winding into a roll, prevention of blocking during storage, and the like can be considered.

Various additives such as a heat stabilizer, an antioxidant, a plasticizer, an antistatic agent, a lubricant, a pigment, a colorant, a nucleating agent, fine particles are added to the resin layer A and / or the adhesive layer B. Etc. may be added.

The thickness of the resin layer A is usually from 10 to 20.
μ and the adhesive layer B are usually preferably 1 to 15 μm as the film for print lamination, but the numerical ranges of these are not particularly limited.

In order to form the print laminating film of the present invention, the adhesive layer B (or the resin layer A) is stretched in one direction while the resin layer A (or the adhesive layer B) is melt-extruded and formed. A method in which melt extrusion lamination is performed by another extruder in the in-line, stretched in a direction perpendicular to the stretching direction, and if necessary, a heat treatment step is continuously performed in one step. After laminating the layer B by a co-extrusion method or the like, successively biaxially stretching or simultaneously biaxially stretching,
If necessary, a method of heat treatment can be exemplified, but is not particularly limited. When the film of the present invention is used, for example, as a heat-shrinkable film, the heat-shrinkability is such that the shrinkage in the vertical or horizontal direction of the film is 3 to 100 ° C. for 5 minutes in a dry atmosphere.
About 60% is preferable, but this numerical range is not limited.
An appropriate amount may be selected depending on the target substance.

The adhesive layer B of the print laminating film of the present invention is desirably subjected to a surface treatment in order to impart thermal adhesion to printing paper or the like. The treatment may be performed by an appropriate method, but corona discharge treatment is particularly preferable. Corona discharge treatment strength, film temperature during treatment, treatment atmosphere, and the like may be appropriately selected according to the intended lamination strength, and are not particularly limited. If necessary, the surface of the resin layer A may be subjected to a corona discharge treatment, and this is not particularly limited.

Next, the film for print lamination of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of a print-laminated film of the present invention and print paper, wherein 1 is a resin layer A made of a polypropylene-based resin containing a petroleum resin, and 2 is at least 25% by weight of a polyolefin-based resin. The adhesive layer B contained. Reference numeral 3 denotes a printed printing paper serving as a base material. The surfaces of the resin layer A and the adhesive layer B are subjected to corona discharge treatment 4, and are laminated so that the adhesive layer B is in contact with the printing surface of the printing paper.

Next, one embodiment of the present invention will be described based on examples, but it is needless to say that the present invention is not limited to these.

[0017]

【Example】

Example 1 A composition comprising 80% by weight of a crystalline polypropylene resin and 20% by weight of a hydrogenated petroleum resin was supplied to an extruder, melted at 260 ° C., extruded into a sheet, and cooled. Solidified. Subsequently, the film was stretched 5 times in the machine direction by a machine for stretching in the same line to obtain a uniaxially stretched sheet (layer A). On the other hand, another extruder installed on the same production line was charged with 88% by weight of an ethylene / vinyl acetate copolymer (vinyl acetate content 25%), 10% by weight of an ethylene / propylene block copolymer, and 2% by weight of silica. % Of the composition and melt-extruded at 280 ° C. to form a laminate (B
Layer) and stretched 8 times in the transverse direction (direction perpendicular to the extrusion direction) at 160 ° C., and then guided to the room after the heat treatment at 160 ° C.
Relax 8% laterally, then slowly cool to room temperature. Next, a corona discharge treatment (treatment conditions were 3
0 w · min / m ² ) to give 15 μm of A layer and 10 μm of B layer
Was obtained. A heat roll temperature of 100 ° C., a pressure of 35 kg / cm, and a speed of 25 m /
Print lamination was performed by thermocompression bonding under the conditions of min. Table 1 shows the surface gloss of the printing surface of the printing paper and the lamination strength between the film and the printing paper.

COMPARATIVE EXAMPLE Crystalline polypropylene resin was fed to an extruder to give 260
After melt-extrusion cooling and solidification at ℃, it was stretched 5 times in the machine direction to obtain a uniaxially stretched sheet. Subsequently, the film was stretched 8 times in the transverse direction at 160 ° C. Then, after the heat treatment at 160 ° C., 8
% Relaxed, slowly cooled to room temperature, and subjected to corona discharge treatment (30 w · min / m ² ) to a thickness of 15
to obtain a biaxially oriented polypropylene-based film (resin layer A). On the other hand, while the composition having the same composition as the adhesive layer B of Example 1 was melt-extruded in another extruder outside the in-line, extrusion lamination was performed on one surface of the biaxially oriented polypropylene-based film, and the resin layer A had a thickness of 15 μm. A film of print B having a thickness of 10 μm was obtained. 100 ° C., pressure 35 kg / cm, speed 25 so that the adhesive layer B of the obtained print laminating film is in contact with the printing surface of the printing paper.
Print lamination was performed by thermocompression bonding at m / min. Table 1 shows the surface glossiness of the printing surface of the printing paper and the lamination strength between the printing paper and the film for printing lamination. At this time, the surface glossiness was measured according to JIS-k-6783. The lamination strength is indicated by the average peel strength when 10 test pieces having a width of 15 mm from the printed laminated paper were peeled at 180 degrees.

[0020]

[Table 1]

As is apparent from the above, the print laminating film of the present invention has better surface gloss and laminating strength than the conventional print laminating film, and is expected to be used in a wide range of fields in the future.

[0022]

The film for print lamination of the present invention is obtained by laminating a resin layer A and an adhesive layer B. Therefore, for example, when laminated on printing paper, excellent surface glossiness and lamination strength of the printed surface can be imparted. The present invention is not limited to printing paper, but also includes films, metals,
It can also be used as a film for lamination with wood, etc., and is expected to have a wide range of applications in the future.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a print laminating film of the present invention.

[Explanation of symbols]

 1. 1. resin layer A 2. Adhesive layer B Base material 4. Corona discharge treatment 5. printing

Claims (1)

(57) [Claims] 1. A print laminating film comprising a surface resin layer A made of a polypropylene resin containing a petroleum resin and an adhesive layer B containing at least 25% by weight of a polyolefin resin laminated on one surface of the surface resin layer A.