JPH11198312A - Multilayered film or sheet made of olefinic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance damage resistance, heat resistance and cutting properties without damaging characteristics such as excellent high frequency welder characteristics or the like in an ethylene/methyl methacrylate copolymer resin film or sheet. SOLUTION: A multilayered film or sheet made of an olefinic resin is obtained by laminating outer layers 12(a), 12(b) based on isotactic polypropylene or a mixture of this polypropylene and at least one of a hydrogenated styrene/ butadiene rubber, a hydrogenated styrene/isoprene rubber and an ethylenic elastomer on both surfaces of an intermediate layer 11 comprising an olefinic resin based on at least one resin selected from an ethylene/(meth)acrylate copolymer resin and an ethylene/vinyl actate copolymer resin through adhesive layers 13(a), 13(b) comprising an olefinic polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flexible multilayer film or sheet (hereinafter referred to as "film / sheet") made of an olefin resin used for stationery, various cases, packaging, agricultural use, and the like. Sometimes)
More specifically, the present invention relates to a flexible multilayer film / sheet made of an olefin resin having excellent suitability for high-frequency welding, excellent scratch resistance, heat resistance, and cutting properties.

[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 a defect that the surface is easily scratched (poor in scratch resistance),
Conventionally, various proposals have been made to improve this, specifically, proposals such as adding a fatty acid amide and forming a coating film on the surface have been made.

[0004] However, in order to improve the scratch resistance by the above-described method, it has been found that the film / sheet made of an ethylene-methyl methacrylate copolymer resin or an ethylene-vinyl acetate copolymer resin has an inherent high frequency welder. In many cases, such characteristics as being excellent 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 film / sheet made of an ethylene-methyl methacrylate copolymer resin, an ethylene-vinyl acetate copolymer resin, or the like, which has improved scratch resistance, heat resistance, and cutting property without impairing the inherent properties of the film / sheet. It is to improve disadvantages such as inferiority.

[0007]

Means for Solving the Problems A film / sheet of the present invention made to solve the above-mentioned problems is characterized in that an olefin resin is provided on both sides of an intermediate layer made of an olefin resin via an adhesive layer made of an olefin polymer. An olefin-based resin multilayer film or sheet obtained by laminating an outer layer made of a resin, and an olefin-based resin forming an intermediate layer,
An olefin resin mainly composed of at least one selected from ethylene- (meth) acrylate copolymer resin and ethylene-vinyl acetate copolymer resin, wherein the olefin resin forming the outer layer is (a) isotactic polypropylene. Any of olefinic resins mainly composed of a mixture of isotactic polypropylene and one or more selected from hydrogenated styrene-butadiene rubber, hydrogenated styrene-isoprene rubber, and ethylene-based elastomer It is a multilayer film or sheet made of an olefin resin characterized by the above.

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 monomer component other than ethylene and vinyl acetate may be copolymerized.

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.

The olefin resin multilayer film / sheet of the present invention has an outer layer made of an olefin resin laminated on both surfaces of the above-mentioned intermediate layer via an adhesive layer made of an olefin polymer. As described above, the olefin resin forming the outer layer includes (a) an olefin resin mainly composed of isotactic polypropylene, (a) isotactic polypropylene, hydrogenated styrene-butadiene rubber, and hydrogenated styrene-isoprene rubber. And an olefin resin mainly composed of a mixture with at least one selected from ethylene elastomers.

Examples of the isotactic polypropylene forming the outer layer include isotactic homopolypropylene which is a homopolymer of propylene, isotactic random polypropylene in which propylene and ethylene are copolymerized at random, and block copolymer of propylene and ethylene. Can be used, but it is suitable for high-frequency welder, contains no colorant or has a small amount of colorant added (that is, colored and transparent).
From the viewpoint of transparency in the case of a film or sheet, isotactic random polypropylene is particularly preferred. Further, as long as its properties are not impaired, it may be copolymerized with other monomers other than the above.

The olefin resin forming the outer layer is selected from the olefin resin (a) described above, that is, isotactic polypropylene, hydrogenated styrene-butadiene rubber, hydrogenated styrene-isoprene rubber, and ethylene-based elastomer. When using an olefin resin mainly containing a mixture with one or more of the above, the mixing ratio of hydrogenated styrene-butadiene rubber or the like mixed with isotactic polypropylene is preferably 50% by weight or less, particularly preferably 20% by weight or less. .

As the above-mentioned hydrogenated styrene-butadiene rubber and hydrogenated styrene-isoprene rubber, those having a styrene content of about 5 to 30% by weight are preferred.

As the above-mentioned ethylene elastomer,
A copolymer of ethylene and α-olefin having a density of about 0.850 to 0.910 g / cm ³ , specifically, ethylene and propylene, butene-1, pentene-1, hexene-1, heptene-1, Copolymers with one or more α-olefins selected from octene-1, nonene-1, deken-1 and the like can be used.

In both cases where the olefin resin (a) and the olefin resin (a) are used as the olefin resin for forming the outer layer, the mixing ratio of hydrogenated styrene-butadiene rubber and the like is not limited. As long as there is no significant departure from the above range, there is no particular difference in scratch resistance, high-frequency welder suitability, heat resistance, and cutability. A more flexible film / sheet is obtained as compared with the case of using the olefin resin (a). Therefore, whether to use the olefin resin (a) or the olefin resin (a) as the olefin resin for forming the outer layer is determined, for example, in applications where higher flexibility is required. If it is used, it is appropriately performed depending on the use of the obtained film or sheet, such as using the olefin-based resin (a).

The olefin resin forming the outer layer may include, if necessary, an antistatic agent, an antioxidant, a light stabilizer such as 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 resins, specifically, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, Polyethylene, such as high-density polyethylene; copolymers of ethylene with vinyl acetate, (meth) acrylate, etc., and syndiotactic polypropylene (random or block copolymers of propylene and ethylene, ie, random polypropylene) , Block polypropylene, etc.); polybutene; olefin rubber; etc. may be mixed.

The olefin resin multilayer film / sheet of the present invention comprises an outer layer laminated on both surfaces of an intermediate layer. These laminates are formed by bonding an olefin polymer to an adhesive layer between the intermediate layer and the outer layer. Is performed via As the olefin polymer forming the adhesive layer, any one can be used as long as it can bond the intermediate layer and the outer layer, but preferably, syndiotactic polypropylene, It is at least one selected from polybutene, butene-α-olefin copolymer, and olefin-based adhesive resin. When outer layers are laminated on both surfaces of the intermediate layer via an adhesive layer made of such an olefin-based polymer, not only the interlayer adhesion is excellent, but also the suitability of the obtained film / sheet for high-frequency welding is high. There is also an advantage of improving. Of course, as long as the adhesiveness is not impaired, it may contain various additives as described above and polymers other than the above-mentioned olefin-based polymer. The olefin-based adhesive resin includes an ethylene- (meth) acrylic acid copolymer resin, an ethylene-methyl methacrylate- (meth) acrylic acid copolymer resin, an ethylene-maleic anhydride copolymer resin, and the like.

As means for laminating the outer layer on both surfaces of the intermediate layer, the olefin resin composition for forming the adhesive layer between the olefin resin composition for forming the intermediate layer and the olefin resin composition for forming the outer layer may be used. Coextrusion method through which the polymer composition is interposed (three layers and five layers coextrusion method), coextrusion inflation method in the same manner, and the method of calendering, extruding, inflation, etc. Separately, and a method of heat laminating by sandwiching the above-mentioned adhesive layer formed into a film between them, an intermediate layer and an outer layer are separately formed by a calender method, an extrusion method, an inflation method, etc. , A method in which an olefin-based polymer composition that forms adhesiveness in a molten state obtained by extruding from a T-die of an extruder and the like is sandwiched therebetween, and pressure-bonded. Is Nawa. Of course, for the purpose of further improving the adhesiveness, a corona discharge treatment, a primer treatment, or the like can be performed prior to the lamination.

The olefin resin multilayer film of the present invention
The thickness of the sheet is not particularly limited, but is generally 0.03 to 2.0 mm as the above application.
It is.

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 thickness of the above-mentioned adhesive layer is not particularly limited as long as the intermediate layer and the outer layer can be bonded to each other, and is not particularly limited. Generally, a thickness of about 5 to 30 μm is sufficient. It is.

The multilayer film / sheet made of 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, since the portion where the coating film is formed significantly deteriorates the suitability for a high-frequency welder, a coating film may be formed. Need to keep this in mind. Of course, the same applies to the case of forming a print pattern.

The olefin-based resin multilayer film / sheet of the present invention having the above-mentioned constitution is soft, has excellent scratch resistance and heat resistance, and does not contain a colorant or has a small amount of a colorant added. (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.

[0031]

EXAMPLES Specific examples of the present invention will be described below, but the present invention is not limited to the following examples.

Examples 1 to 9 and Comparative Examples 1 to 3 The olefin-based resin composition for the intermediate layer, the olefin-based resin composition for the outer layer and the olefin-based polymer composition for the adhesive layer having the composition shown in Table 1. And co-extruded with a multilayer T-die extruder to obtain a total thickness of 0.3 mm, a thickness of the intermediate layer of 0.2 mm, a thickness of each outer layer of 0.03 mm, and a thickness of each adhesive layer of 0.3 mm.
An olefin resin multilayer film of 02 mm (20 μm) was obtained. However, Comparative Example 1 was a three-layer film having a total thickness of 0.3 mm in which an outer layer having a thickness of 0.05 mm was formed without interposing an adhesive layer, and Comparative Examples 2 and 3 did not form an outer layer.
It was a single-layer film having a thickness of 0.3 mm. In addition, the obtained film was evaluated for suitability for high-frequency welding, scratch resistance, transparency, interlayer adhesion, heat resistance, and cutability according to the following criteria.

A) Suitability for high-frequency welder ：: Bonding possible without heating the welder blade 可能: Bonding possible by heating the welder blade to 40-60 ° C. △: Bonding by heating the welder blade to 70 ° C. or higher Possible ×: High-frequency welding is practically impossible. B) Flaw resistance Gakushin-type friction tester (Kanakin No.3, No. 50 rubbing)
), The haze value (unit%) was measured based on JIS-K-6714, and compared with the haze value before rubbing. ：: haze increase is less than 20% x: haze increase is 20% or more c) transparency ：: haze value is less than 5% ：: haze value is 5% or more and less than 10% x: haze value is 10% or more d) Adhesion between layers ：: good (no separation between layers of each layer during welding of high-frequency welder) ×: poor (separation occurs between layers of each layer during welding of high-frequency welder) e) Heat resistance 、 １: 1 hour at 100 ° C No deformation is observed even when left undisturbed. X: Deformation is observed when left at 100 ° C. for 1 hour. F) Cutability ○: No deformation is observed when 50 films are stacked and cut. X: Film Deformation is seen in the film when cutting 50 sheets

[0034]

[Table 1]

For reference, FIG. 1 shows an enlarged cross-sectional view of a part of the olefin resin multilayer film of Example 1. Reference numeral 1 in the figure denotes a multilayer film made of an olefin-based resin, and reference numeral 1 denotes
Reference numeral 1 denotes an intermediate layer, reference numerals 12 (a) and (b) denote outer layers, and reference numerals 13 (a) and (b) denote adhesive layers.

[0036]

As described in detail above, the multilayer film / sheet made of an olefin resin of the present invention is excellent in high frequency welder suitability, scratch resistance, heat resistance, and cutting property, for stationery, various cases, packaging, and agriculture. It can be suitably used for applications 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.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view showing a multilayer film made of an olefin-based resin of Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Multilayer film made of olefin resin 11 ... Middle layer 12 (a), 12 (b) ... Outer layer 13 (a), 13 (b) ... Adhesive layer

Claims (6)

[Claims] An olefin resin multilayer film or sheet comprising an olefin resin-containing outer layer laminated on both surfaces of an olefin resin-containing intermediate layer via an olefin polymer adhesive layer. The olefin resin forming 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 forming the outer layer. -Based resin is an olefin-based resin mainly composed of isotactic polypropylene,
Multilayer film or sheet made of olefin resin. 2. An olefin resin multilayer film or sheet comprising an olefin resin-containing outer layer laminated on both surfaces of an intermediate layer made of an olefin resin via an adhesive layer made of an olefin polymer. The olefin resin forming 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 forming the outer layer. The olefin resin is a multi-layer made of olefin resin, wherein the olefin resin is a mixture of isotactic polypropylene and one or more selected from hydrogenated styrene-butadiene rubber, hydrogenated styrene-isoprene rubber, and ethylene elastomer. Film or sheet. 3. The mixing ratio of at least one selected from hydrogenated styrene-butadiene rubber, hydrogenated styrene-isoprene rubber and ethylene-based elastomer contained in the olefin resin forming the outer layer is 50% by weight or less. Item 4. An olefin resin multilayer film or sheet according to Item 2. 4. The isotactic polypropylene according to claim 1, wherein the isotactic polypropylene is a random polypropylene.
The multilayer film or sheet made of an olefin-based resin according to any one of claims 1 to 3. 5. An olefin polymer forming an adhesive layer, wherein the olefin polymer is syndiotactic polypropylene, polybutene,
The olefin resin multilayer film or sheet according to any one of claims 1 to 4, wherein the multilayer film or sheet is at least one selected from a butene-α-olefin copolymer and an olefin adhesive resin. 6. The thickness ratio between the intermediate layer and the outer layer is 2: 1.
The olefin resin multilayer film or sheet according to any one of claims 1 to 5, wherein the ratio is in the range of from 20 to 20: 1.