JPH11198308A - Olefin-based resin multilayer film or sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the high frequency welder characteristics and scratch resistance of a film by a structure wherein the film consists of an olefin-based resin intermediate layer mainly made of an ethylene-ester (meth)acrylate copolymer resin or ethylene-vinyl acetate copolymer resin and olefin-based resin outer layers mainly made of an ionomer. SOLUTION: An olefin-based resin, which forms the intermediate layer 1.1 of an olefin-based resin multilayer film 1, is an olefin-based resin mainly made of the resin selected from a group consisting of an ethylene-ester (meth)acrylate copolymer resin and an ethylne-vinyl acetate copolymer resin or an olefin-based resin mainly made of a mixture of two or more resins selected from the above- mentioned group. An olefin-based resin, of which outer layers 12(a) and 12(b) to be formed on both the sides of the intermediate layer 11 is an olefin-based resin mainly made of ionomer. Thus, the high frequency welder characteristics, scratch resistance and cutting properties of the film can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a flexible multilayer film or sheet made of an olefin resin used for stationery, various cases, packaging, agricultural use, etc.
For details, refer to "Film / Sheet"). For more information, refer to Soft multilayer film made of olefin resin with excellent suitability for high frequency welder, scratch resistance, heat resistance, and cutting property.
It is about a sheet.

[0002]

2. Description of the Related Art Conventionally, flexible films and sheets made of synthetic resin have been used for stationery, various cases, packaging, agricultural use, and the like. Further, as this film / sheet, a single-layer film / sheet made of an ethylene-methyl methacrylate copolymer resin or an ethylene-vinyl acetate copolymer resin is known.

[0003]

The single-layer film / sheet composed of the above-mentioned ethylene-methyl methacrylate copolymer resin or ethylene-vinyl acetate copolymer resin has the advantages of flexibility and excellent suitability for high-frequency welding. In terms of point, it can be said that it is suitable for use in the above applications that often require secondary processing, but on the other hand, it has the disadvantage that the surface is easily scratched (poor in scratch resistance). Various proposals have been made to improve the above, specifically, such as adding a fatty acid amide or forming a coating film on the surface.

[0004] However, in order to improve the scratch resistance by the above-described method, it is difficult to use a high frequency welder which is inherently provided in a film or sheet made of an ethylene-methyl methacrylate copolymer resin or an ethylene-vinyl acetate copolymer resin. In many cases, such characteristics as being excellent in the properties are impaired.

Further, a single-layer film or sheet made of an ethylene-methyl methacrylate copolymer resin or an ethylene-vinyl acetate copolymer resin is inferior in heat resistance, and tends to be deformed even at a temperature of about 80 to 90 ° C. There is also a drawback or a defect that the cutting property is inferior and the blade is hard to enter at the time of cutting, so that the vicinity of the end (the end formed by cutting) is elongated and easily deformed.

[0006] The present invention provides a method for producing a film or sheet comprising an ethylene-methyl methacrylate copolymer resin or an ethylene-vinyl acetate copolymer resin without impairing the inherent properties of the film or sheet. It is intended to further improve the high-frequency welder characteristics as compared with the resulting film / sheet and to improve defects such as poor scratch resistance, heat resistance and cutability.

[0007]

Means for Solving the Problems A film / sheet according to the present invention made to solve the above-mentioned problems comprises an intermediate layer made of an olefin resin and an outer layer, and the olefin resin forming the intermediate layer is made of ethylene. An olefin resin mainly composed of at least one selected from a (meth) acrylate copolymer resin and an ethylene-vinyl acetate copolymer resin, wherein the olefin resin forming the outer layer is an olefin resin mainly composed of an ionomer; A multilayer film / sheet made of an olefin-based resin, characterized in that:

The olefin resin forming the intermediate layer of the olefin resin multilayer film / sheet of the present invention is selected from ethylene- (meth) acrylate copolymer resins and ethylene-vinyl acetate copolymer resins as described above. Is an olefin resin mainly composed of a resin or a mixture of two or more selected from these.

The ethylene- (meth) acrylate copolymer resin is obtained by copolymerizing ethylene with an acrylate ester and / or methacrylate ester. Specifically, the above-mentioned ethylene-methyl methacrylate copolymer resin is used. In addition to the resin, an ethylene-methyl acrylate copolymer resin, an ethylene-ethyl acrylate copolymer resin, and the like can be used.

The ethylene- (meth) acrylate copolymer resin has a (meth) acrylate component of 5 to 30% by weight, particularly 15 to 30% by weight from the viewpoint of suitability for a high frequency welder. Is preferred.

Of course, the ethylene- (meth) acrylate copolymer resin may be a mixture of different types of (meth) acrylate and its content, etc., copolymerized with ethylene. . In addition, as long as the properties of the obtained film / sheet are not impaired,
A copolymer of a monomer component other than ethylene and (meth) acrylate may be used.

As the ethylene-vinyl acetate copolymer resin, a resin having a vinyl acetate component of 5 to 30% by weight, particularly 15 to 30% by weight from the viewpoint of suitability for high frequency welding is preferred.

Of course, the ethylene-vinyl acetate copolymer resin may be a mixture of resins having different vinyl acetate contents. Further, as long as the properties of the obtained film / sheet are not impaired, a copolymer of monomer components other than ethylene and vinyl acetate may be used.

If necessary, one or more olefin resins selected from ethylene- (meth) acrylate copolymer resins and ethylene-vinyl acetate copolymer resins constituting the intermediate layer may have an antistatic agent, an antioxidant, Agents, light stabilizers such as hindered amine compounds, lubricants, ultraviolet absorbers,
Various additives such as an inorganic filler and a coloring agent such as a pigment may be added.

The intermediate layer of the olefin resin multilayer film / sheet of the present invention comprises an ethylene- (meth) acrylate copolymer resin and an ethylene-vinyl acetate copolymer resin to which various additives are added as required. It is formed of one or more selected olefin-based resins. The ethylene- (meth) acrylate copolymer resin and ethylene-vinyl acetate described above may be used as long as the properties of the resulting film or sheet are not impaired. Polymers other than copolymer resins, specifically, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, polyethylene such as high-density polyethylene; isotactic or syndiotactic polypropylene (random of propylene and ethylene, Block copolymers, ie random polypropylene, block poly Including such propylene); polybutene; olefin rubbers, ethylene-based elastomer; like no problem even by mixing.

In the multilayer film / sheet made of olefin resin of the present invention, outer layers made of olefin resin are formed on both surfaces of the above-mentioned intermediate layer. As described above, the olefin resin forming the outer layer is an olefin resin mainly composed of an ionomer.

The ionomer which forms the outer layer is formed of sodium ion, potassium ion, magnesium ion, zinc ion between the molecular chains (between carboxyl groups in the molecular chain) of the ethylene-acrylic acid copolymer or the ethylene-methacrylic acid copolymer. Crosslinked with metal ions such as ions. Further, as long as the properties are not impaired, a copolymer of monomer components other than ethylene, acrylic acid and methacrylic acid may be used.

The olefin resin forming the outer layer may include, if necessary, a light stabilizer such as an antistatic agent, an antioxidant, a hindered amine compound, a lubricant, an ultraviolet ray, similarly to the olefin resin forming the intermediate layer. Various additives such as an absorbent, an inorganic filler, and a coloring agent such as a pigment may be added.

As long as the properties of the obtained film / sheet are not impaired, polymers other than the above-mentioned olefin resin (ionomer), specifically, low density polyethylene, linear low density polyethylene, medium density Polyethylene such as polyethylene and high-density polyethylene; isotactic or syndiotactic polypropylene (including random and block copolymers of propylene and ethylene, that is, random polypropylene and block polypropylene, etc.); polybutene; olefin-based rubber; Hydrogenated styrene-butadiene rubber; hydrogenated styrene-isoprene rubber; and the like.

The olefin resin multilayer film / sheet of the present invention is formed by forming outer layers on both surfaces of an intermediate layer. Preferably, the forming means is a co-extrusion method or a co-extrusion inflation method in which the production process is simple. It is. Of course, the intermediate layer and the outer layer are separately formed by means such as a calendering method, an extrusion method, and an inflation method, and the multilayer of the present invention is formed by laminating them by means such as heat lamination or bonding with an appropriate adhesive. A film sheet can be obtained. The olefin resin multilayer film / sheet of the present invention also has an advantage that the interlayer adhesion is excellent without an adhesive between the intermediate layer and the outer layer.

The thickness of the olefin-based resin multilayer film / sheet of the present invention is not particularly limited.
m.

The ratio of the thickness of the intermediate layer to the thickness of each of the outer layers in the olefin resin multilayer film / sheet of the present invention is preferably in the range of 2: 1 to 20: 1. When the thickness ratio of the intermediate layer and the outer layer deviates significantly from the above range, a multilayer film that can solve the problem of the present invention.
I can't get a sheet. Note that the thickness of both outer layers does not necessarily have to be the same.

The multilayer film / sheet made of an olefin resin of the present invention can form an embossed pattern such as satin or silk on one or both sides, or can form a printed pattern by ordinary printing. In addition, it is also possible to form a coating film of various paints such as water-based, solvent-based, and ultraviolet-curing types.However, the portion where the coating film is formed is significantly reduced in suitability for a high-frequency welder. Need to keep this in mind. Of course, the same applies to the case of forming a print pattern.

The multilayer film / sheet made of the olefin resin of the present invention having the above constitution is soft, has excellent scratch resistance and heat resistance, does not contain a colorant, or has a small amount of a colorant. (That is, in the case of a colored transparent film or sheet), it is also excellent in transparency. Further, since it is excellent in high frequency welder suitability and cutting property, it is suitable for use in applications requiring secondary processing.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific examples of the olefin resin multilayer film / sheet of the present invention will be described with reference to the drawings.

FIG. 1 is a partially enlarged cross-sectional view of one embodiment of the multilayer film / sheet made of an olefin resin of the present invention.
Reference numeral 1 in the figure denotes an olefin resin multilayer film, 11
Is an intermediate layer, and 12 (a) and (b) are outer layers.

In the present embodiment, the intermediate layer 11 is made of an ethylene-methyl methacrylate copolymer resin (Aclift WH20).
2; trade name, manufactured by Sumitomo Chemical Co., Ltd., and on both sides thereof, an outer layer 12 (a) composed of an ionomer (Himilan 1605; trade name, manufactured by Mitsui Dupont Chemical Co., Ltd.);
(B) is formed. The thickness of the intermediate layer is 0.2
The thickness of each of the outer layers 12 (a) and 12 (b) is 0.025 mm (the thickness of the entire multilayer film 1 is 0.3 mm).

The olefin resin multilayer film 1 of the present embodiment
Is an olefin-based resin composition for forming the intermediate layer 11,
It is obtained by co-extrusion of the olefin resin composition forming the outer layers 12 (a) and (b) with a three-layer T-die extruder.

The olefin resin multilayer film 1 of the present embodiment
Is excellent in high frequency welder suitability and also excellent in scratch resistance, transparency, interlayer adhesion, heat resistance and cutting properties, and is suitable for stationery, various cases, packaging, agricultural use, etc. Met.

Further, a resin using an ethylene-vinyl acetate copolymer resin (Evatate H-2031; trade name, manufactured by Sumitomo Chemical Co., Ltd.) as the olefin resin forming the intermediate layer 11 also has various performances equivalent to those of this example. Had.

[0031]

As described in detail above, the olefin resin multilayer film / sheet of the present invention is excellent in high-frequency welder suitability, scratch resistance, heat resistance and cutting properties, for stationery, for various cases, for packaging, It can be suitably used for agricultural purposes and the like.

When the amount of the coloring agent is small or when no coloring agent is added, there is an advantage that the transparency is excellent.

Furthermore, the olefin resin multilayer film / sheet of the present invention has excellent interlayer adhesion even without an adhesive between the intermediate layer and the outer layer. It can be manufactured.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view of one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Multilayer film made of olefin resin 11 ... Intermediate layer 12 (a), (b) ... Outer layer

Claims (2)

[Claims] An olefin-based resin multilayer film or sheet comprising an olefin-based resin intermediate layer and olefin-based resin outer layers formed on both surfaces thereof, wherein the olefin-based resin forms the intermediate layer. Is an olefin resin mainly composed of at least one selected from ethylene- (meth) acrylate copolymer resin and ethylene-vinyl acetate copolymer resin, and the olefin resin forming the outer layer is mainly composed of an ionomer. An olefin resin-based multilayer film or sheet, which is an olefin resin. 2. The thickness ratio between the intermediate layer and the outer layer is 2: 1.
The olefin resin multilayer film or sheet according to claim 1, wherein the ratio is in the range of 20 to 20: 1.