WO2024203319A1 - Resin composition, modifier, and composition containing said modifier - Google Patents

Abstract

The present disclosure relates to a resin composition (A) comprising: 50 parts by mass to 99 parts by mass inclusive of a composition (a1) comprising at least two ethylene-(vinyl acetate) copolymers having different vinyl acetate contents from each other; and 1 part by mass to 50 parts by mass inclusive of a styrene-based block copolymer (a2) (wherein the total amount of the components (a1) and (a2) is 100 parts by mass).

Description

Resin composition, modifier and composition containing the modifier

The present invention relates to a resin composition that contains a composition containing at least two types of ethylene-vinyl acetate copolymers with different vinyl acetate contents, and a styrene-based block copolymer.

In recent years, interest in the problem of environmental pollution caused by plastics has increased, and material recycling of plastic products has been promoted.

In the case of plastic material recycling, if different types of plastics are mixed in the collected plastic waste, there is a problem that the physical properties of the recycled plastic deteriorate due to their poor compatibility with each other.

As a result, the current process involves sorting collected plastic waste by material and then recycling it into products.

However, in the case of multi-layer films or containers made of different types of plastics (hereinafter referred to as composite plastics), it is difficult to separate the individual materials, so they cannot be recycled and are currently either landfilled or incinerated.

Against this background, the addition of compatibilizers is being considered as a means of recycling composite plastics.

For example, Patent Document 1 shows that the physical properties of composite plastics, such as composite plastics of polyethylene (PE) and polyethylene terephthalate (PET), or composite plastics of polypropylene (PP) and acrylonitrile-butadiene-styrene copolymer (ABS), can be improved by adding a compatibilizer.

However, while the inventors were investigating the recycling of composite plastics, they discovered that when a resin containing polyester in polyolefin was made into a film, a defect in appearance known as fish eyes frequently occurred.

Japanese Patent Application Publication No. 2001-220473

The present invention aims to provide a resin composition that is effective in reducing fisheyes that occur when a thermoplastic resin containing two or more plastic components is made into a film, and a modifier made from the resin composition. Furthermore, the present invention aims to provide a modifier that can produce a recycled film with good appearance from waste containing multiple plastics.

As a result of intensive research aimed at solving the above problems, the inventors discovered that a resin composition containing a specific ethylene-vinyl acetate copolymer and a styrene-based block copolymer is highly effective at reducing fisheyes that occur when a thermoplastic resin containing two or more plastic components is made into a film, and thus completed the present invention.

The resin composition (A), which is one embodiment of the present invention, contains 50 to 99 parts by mass of a composition (a1) containing at least two types of ethylene-vinyl acetate copolymers differing in vinyl acetate content, and 1 to 50 parts by mass of a styrene-based block copolymer (a2) (where the sum of (a1) and (a2) is 100 parts by mass).

The resin composition of one embodiment of the present invention is effective as a modifier for thermoplastic resins containing two or more plastic components, and films of the modified thermoplastic resin have few fisheyes and excellent film appearance, making them useful for molded products that require these physical properties.

The present invention will now be described in detail with reference to preferred embodiments.

<Resin composition (A)>
The resin composition (A) according to one embodiment of the present invention is a composition (a1) containing at least two kinds of ethylene-vinyl acetate copolymers having different vinyl acetate contents, and a styrene-based The block copolymer (a2) is contained in an amount of 1 part by mass or more and 50 parts by mass or less.

Each ethylene-vinyl acetate copolymer in composition (a1) (hereinafter referred to as "EVA composition (a1)"), which comprises at least two types of ethylene-vinyl acetate copolymers differing in vinyl acetate content and which constitutes resin composition (A), can be obtained by a known manufacturing method. Specifically, manufacturing methods such as high-pressure radical polymerization, solution polymerization, or emulsion polymerization can be mentioned. The ethylene-vinyl acetate copolymer can be conveniently selected from commercially available products, and is commercially available under the trade name Ultrathene from Tosoh Corporation and under the trade name Levaprene from Lanxess KK.

The vinyl acetate content of the ethylene-vinyl acetate copolymer, measured according to JIS K6924-1, is preferably 6% by mass or more and 90% by mass or less, and more preferably 15% by mass or more and 85% by mass or less. A vinyl acetate content of 6% by mass or more is preferred because it has excellent compatibility with polyesters, while a vinyl acetate content of 90% by mass or less is preferred because it has excellent compatibility with polyolefins.

From the viewpoint of compatibility, the ethylene-vinyl acetate copolymer contained in the EVA composition (a1) is preferably two or more types, more preferably three or more types. In addition, the difference in vinyl acetate content between each ethylene-vinyl acetate copolymer is preferably 1% by mass or more, more preferably 5% by mass or more. Furthermore, the difference in vinyl acetate content between at least one pair of ethylene-vinyl acetate copolymers is preferably 40% by mass or less, more preferably 20% by mass or less, and most preferably 15% by mass or less.

Here, in the EVA composition (a1), the difference in vinyl acetate content between each ethylene-vinyl acetate copolymer can be calculated as follows, for example, in a composition containing three types of ethylene-vinyl acetate copolymers having vinyl acetate contents of 25 mass%, 50 mass%, and 80 mass% (hereinafter, the vinyl acetate contents will be referred to as VAc25, VAc50, and VAc80, respectively).
VAc50 - VAc25 = 25% by mass
VAc80 - VAc50 = 30% by mass
VAc80 - VAc25 = 55% by mass

The styrene-based block copolymer (a2) constituting the resin composition (A) may be composed of at least one polymer block mainly composed of styrene monomer units and at least one polymer block mainly composed of conjugated diene compound monomer units. The styrene-based block copolymer (a2) may also be a hydrogenated product in which the double bonds are partially saturated/fully saturated by hydrogenation.

In this specification, a polymer block mainly composed of styrene monomer units means that it contains 50% by mass or more of monomer units derived from styrene, when the monomer units in the polymer block are taken as 100% by mass. The content of monomer units derived from styrene contained in a polymer block mainly composed of styrene monomer units may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, or 100% by mass.

In this specification, a polymer block mainly composed of conjugated diene compound monomer units means that the polymer block contains 50% by mass or more of monomer units derived from a conjugated diene compound when the monomer units in the polymer block are taken as 100% by mass. The content of monomer units derived from a conjugated diene compound contained in the polymer block mainly composed of conjugated diene compound monomer units may be 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, or 100% by mass.

Conjugated diene compounds constituting polymer blocks mainly composed of conjugated diene compound monomer units include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, phenylbutadiene, 4,5-diethyl-1,3-octadiene, and 3-butyl-1,3-octadiene. Polymer blocks mainly composed of conjugated diene compound monomer units may be composed of one type of these conjugated diene compounds alone, or two or more types. In addition, they may be subsequently hydrogenated to partially or completely saturate the double bonds.

Specific examples of styrene-based block copolymers (a2) include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), styrene-ethylene-butene-styrene block copolymers (SEBS) which are hydrogenated products of SBS, and styrene-ethylene-propylene-styrene block copolymers (SEPS) which are hydrogenated products of SIS. Among these, styrene-ethylene-butene-styrene block copolymers (SEBS) are preferred in terms of compatibility with ethylene-vinyl acetate copolymers and polyolefins or polyesters.

The proportion of the polymer block made of styrene in the styrene-based block copolymer is preferably 10% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 30% by mass or less. If it is 10% by mass or more, it is preferable because it has excellent compatibility with polyester, and if it is 50% by mass or less, it is preferable because it has excellent compatibility with polyolefin.

In the resin composition (A), the mixing ratio of the EVA composition (a1) and the styrene-based block copolymer (a2) is 50 parts by mass or more and 99 parts by mass or less of the EVA composition (a1), and 1 part by mass or more and 50 parts by mass or less of the styrene-based block copolymer (a2) (where the total of (a1) and (a2) is 100 parts by mass), and preferably 60 parts by mass or more and 90 parts by mass or less of the EVA composition (a1), and 10 parts by mass or more and 40 parts by mass or less of the styrene-based block copolymer (a2) (where the total of (a1) and (a2) is 100 parts by mass). By including 50 parts by mass or more and 99 parts by mass or less of the EVA composition (a1), the film appearance of the blended resin is further improved. On the other hand, by including 1 part by mass or more and 50 parts by mass or less of the styrene-based block copolymer (a2), the fisheyes of the blended resin are further reduced.

The modifier, which is one aspect of the present invention, is described in detail below.

<Resin Compatibilizer (Modifier)>
The resin compatibilizer (hereinafter, may be referred to as a "modifier") according to one embodiment of the present invention contains a resin composition (A).

By blending resin composition (A) as a modifier with the base resin, the appearance of the film when the resin is molded into a film can be improved and fisheyes can be reduced.

In addition, it is preferable that the base material to be blended is a thermoplastic resin containing at least polyolefin and polyester (hereinafter referred to as "thermoplastic resin (B)").

The modifier can be used in any form, such as pellets or powder.

The thermoplastic resin (B) to which the modifier is added may contain at least polyolefin and polyester. In other words, the thermoplastic resin (B) may contain thermoplastic resins other than polyolefin and polyester. Examples of resin components other than polyolefin and polyester include polyamide, ethylene-vinyl alcohol copolymer, polystyrene, etc.

Polyolefins include polyethylene, polypropylene, ethylene-propylene copolymers, ethylene-acrylic acid ester copolymers, and ethylene-methacrylic acid ester copolymers. Polyethylenes include high-density polyethylene, low-density polyethylene, and linear low-density polyethylene.

Polyesters include polyethylene terephthalate, glycol-modified polyethylene terephthalate (PETG resin), polybutylene terephthalate, polylactic acid, etc.

Examples of polyamides include nylon 6, nylon 6,6, nylon 11, and nylon 12.

Among these, the polyolefins contained in the thermoplastic resin (B) are preferably high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and polypropylene, as they have excellent film formability, and low-density polyethylene and linear low-density polyethylene are more preferable. As the polyester, polyethylene terephthalate is preferable, as it has excellent film appearance. As the resin other than polyolefins and polyesters, at least one member of the group consisting of polyamides and ethylene-vinyl alcohol copolymers is preferable.

The ratio of the resins constituting the thermoplastic resin (B) is preferably 70 parts by mass or more and 99 parts by mass or less of polyolefin and 1 part by mass or less and 30 parts by mass or less of polyester, because the strength of the film is excellent, and more preferably 80 parts by mass or more and 99 parts by mass or less of polyolefin and 1 part by mass or less and 20 parts by mass or less of polyester. When resins other than polyolefin and polyester are contained, the ratio of the resins constituting the thermoplastic resin (B) is preferably 70 parts by mass or more and 98 parts by mass or less of polyolefin, 1 part by mass or more and 29 parts by mass or less of polyester, and more preferably 80 parts by mass or more and 98 parts by mass or less of polyolefin, 1 part by mass or more and 19 parts by mass or less of polyester, and 1 part by mass or more and 19 parts by mass or less of resins other than polyolefin and polyester.

The thermoplastic resin (B) may be an unused virgin resin, or a resin obtained by recovering plastic waste. In other words, it includes a form in which all of the one or more types of resin are unused resins, a form in which at least one of the one or more types of resins is a used resin, and a form in which all of the one or more types of resin are used resins.

The plastic waste is not particularly limited, but may be any of the following: burrs or film trimming loss generated in plastic molding factories, waste that cannot be used as products such as non-standard products, or waste from used plastic products collected from the city or consumers. In an embodiment of the present invention, a recycled resin composition is produced as the resin composition by using plastic waste as a material for the resin composition. In addition, when using a resin obtained by collecting plastic waste, it may contain organic substances such as PVC resin, wax, adhesives, plasticizers, and antioxidants, and/or inorganic substances such as fillers as impurities.

<Resin Composition>
A resin composition containing a resin composition (A) and a thermoplastic resin (B) is also included in one aspect of the present invention. The mixing ratio of the resin composition (A) and the thermoplastic resin (B) in the resin composition is preferably 1 part by mass or more and 15 parts by mass or less of the resin composition (A) per 100 parts by mass of the thermoplastic resin (B), and more preferably 1 part by mass or more and 10 parts by mass or less of the resin composition (A). When the resin composition (A) is 1 part by mass or more, it is preferable because it is excellent in improving the film appearance and suppressing fish eyes, and when it is 15 parts by mass or less, it is preferable because it is excellent in film moldability. Specific examples and preferred aspects of the resin composition (A) and the thermoplastic resin (B) are as described in the above item <Resin compatibilizer (modifier)>.

The melt mass flow rate (MFR) of the resin composition containing the resin composition (A) and the thermoplastic resin (B) is not particularly limited, but in order to provide excellent film moldability, the MFR measured under conditions of 190°C and a load of 2.16 kg is preferably 0.5 g/10 min or more and 30 g/10 min or less, more preferably 0.8 g/10 min or more and 20 g/10 min or less, and most preferably 1 g/10 min or more and 10 g/10 min or less.

The method for producing a resin composition containing the resin composition (A) and the thermoplastic resin (B) is not particularly limited as long as it is possible to disperse each component, and the composition can be produced using a commonly used resin kneading device. Examples of kneading devices include single-screw extruders, twin-screw extruders, multi-screw extruders, Banbury mixers, pressure kneaders, rotating rolls, and internal mixers. Among these, twin-screw extruders are preferred because of their excellent dispersibility and continuous productivity.

When kneading with a twin-screw extruder, the screw rotation speed is not particularly limited, but kneading at 50 rpm to 3000 rpm is preferable, and more preferably 150 rpm to 1000 rpm. A screw rotation speed of 50 rpm or more is preferable because it improves the dispersibility of each mixed component and results in excellent physical properties of the resulting resin, while a screw rotation speed of 3000 rpm or less is preferable because it prevents deterioration of the resin due to excessive shear heat generation and results in excellent physical properties of the resulting resin.

The kneading temperature is preferably above the melting point of the component with the lowest melting point in the thermoplastic resin (B) and below about 300°C.

In addition, the resin composition containing the resin composition (A) and the thermoplastic resin (B) may contain antistatic agents, light stabilizers, ultraviolet absorbers, nucleating agents, antioxidants, antiblocking agents, flow improvers, release agents, flame retardants, colorants, inorganic neutralizing agents, hydrochloric acid absorbers, filler conductive agents, chain extenders, hydrolysis inhibitors, and the like, as long as the effects of the present invention are not impaired.

<Molded body>
In addition, the resin composition containing the resin composition (A) and the thermoplastic resin (B) can be used in any form such as pellets or powder. A molded article made of the resin composition containing the resin composition (A) and the thermoplastic resin (B) is also included in one aspect of the present invention.

The method for molding the resin composition is not particularly limited, but examples include profile extrusion, film, sheet, blow, injection, foaming, extrusion coating, and rotational molding. Among these, film is preferred due to the excellent moldability of the resin composition, which is one aspect of the present invention.

A film made of the resin composition is also included in one embodiment of the present invention. The film molding method is not particularly limited, and examples thereof include inflation molding, coextrusion inflation molding, T-die molding, coextrusion T-die molding, calendar molding, and compression molding. Among these, inflation molding, coextrusion inflation molding, T-die molding, and coextrusion T-die molding are preferred because of their excellent productivity. The film according to one embodiment of the present invention may be laminated with other films, and the lamination method is also not particularly limited, and examples thereof include dry lamination, extrusion lamination, and sandwich lamination.

The resin composition containing the resin composition (A) and the thermoplastic resin (B) of this embodiment described above can suppress the occurrence of fisheyes when made into a film. Note that fisheyes are particulate lumps that resemble fish eyes and are caused by foreign matter (unmelted material, etc.) that appears in the film.

The film of one embodiment of the present invention can be obtained by forming the resin composition into a film (molding into a film shape). The film made of the resin composition may be a single layer or may be used in the form of a multilayer film. The lamination structure of the multilayer film is not particularly limited, but may include, for example, not only the layer (I) of the resin composition of one embodiment of the present invention but also layers made of other components, such as a virgin resin layer (II), an adhesive layer (III) or a barrier layer (IV). Specific examples include layer (I)/layer (II), layer (II)/layer (I)/layer (II), layer (I)/layer (III)/layer (IV)/layer (III)/layer (I), layer (I)/layer (III)/layer (IV)/layer (III)/layer (II), etc. The "/" between layers means that the layers are adjacent to each other. The thickness of the film made of the resin composition is not particularly limited, but is preferably 10 μm to 300 μm from the viewpoint of further suppressing the occurrence of fisheyes.

The film forming temperature is preferably in the range of 190°C to 250°C, more preferably in the range of 200°C to 250°C, and even more preferably in the range of 220°C to 250°C. A forming temperature of 190°C or higher is preferable because it reduces the occurrence of fish eyes, while a forming temperature of 250°C or lower is preferable because it provides excellent film formability.

The film is useful as a packaging container for food, daily necessities, industrial parts, medicines, office supplies, chemical products, etc., a surface protection film, an agricultural film such as silage wrap, a shrink film, a transport bag, etc.

〔summary〕
That is, the respective aspects of the present invention are as follows [1] to [15].
[1] A resin composition (A) comprising 50 parts by mass or more and 99 parts by mass or less of a composition (a1) containing at least two kinds of ethylene-vinyl acetate copolymers having different vinyl acetate contents, and 1 part by mass or more and 50 parts by mass or less of a styrene-based block copolymer (a2) (wherein the total of (a1) and (a2) is 100 parts by mass).
[2] The resin composition (A) according to [1], wherein the vinyl acetate content of each ethylene-vinyl acetate copolymer contained in the composition (a1) containing an ethylene-vinyl acetate copolymer is 6% by mass or more and 90% by mass or less.
[3] The resin composition (A) according to [1] or [2], wherein the composition (a1) containing an ethylene-vinyl acetate copolymer contains three or more ethylene-vinyl acetate copolymers having different vinyl acetate contents.
[4] In the ethylene-vinyl acetate copolymer composition (a1), the difference in vinyl acetate content between each ethylene-vinyl acetate copolymer is 1 mass% or more, and further, the difference in vinyl acetate content between at least one pair of ethylene-vinyl acetate copolymers is 40 mass% or less. The resin composition (A) according to any one of [1] to [3].
[5] The resin composition (A) according to any one of [1] to [4], wherein the styrene-based block copolymer (a2) is a block copolymer having at least one polymer block mainly composed of styrene monomer units and at least one polymer block mainly composed of conjugated diene compound monomer units, or a hydrogenated product thereof.
[6] The resin composition (A) according to any one of [1] to [5], wherein the styrene-based block copolymer (a2) is a styrene-butadiene-styrene block copolymer (SBS), a styrene-isoprene-styrene block copolymer (SIS), or a hydrogenated product thereof.
[7] The resin composition (A) according to any one of [1] to [6], wherein the styrene-based block copolymer (a2) is a styrene-ethylene-butylene-styrene block copolymer (SEBS).
[8] The resin composition (A) according to [7], wherein the styrene block ratio of the styrene-ethylene butylene-styrene block copolymer (SEBS) is 10% by mass or more and 50% by mass or less.
[9] A resin compatibilizer comprising the resin composition (A) according to any one of [1] to [8].
[10] A resin composition comprising the resin composition (A) according to any one of [1] to [8] and a thermoplastic resin (B) containing a polyolefin and a polyester, the resin composition (A) being contained in an amount of 1 part by mass or more and 15 parts by mass or less per 100 parts by mass of the thermoplastic resin (B).
[11] The resin composition according to [10], wherein the polyester is polyethylene terephthalate.
[12] The resin composition according to [10] or [11], wherein the resin contained in the thermoplastic resin (B) is a resin obtained by recovering plastic waste.
[13] A molded article made of the resin composition according to any one of [10] to [12].
[14] A film made of the resin composition according to any one of [10] to [12].
[15] A packaging container made of the film according to [14].

The present invention will be explained below with reference to examples and comparative examples, but the present invention is not limited to these.

[Evaluation method]
(1) Melt Mass Flow Rate (MFR)
The MFR of the resin composition and the ethylene-vinyl acetate copolymer was measured using a melt indexer (manufactured by Takara Kogyo Co., Ltd.) at 190° C. and a load of 2.16 kg.

(2) Number of Fisheyes The number of fisheyes per 500 ^cm2 of the prepared film was visually counted.

(3) Total Light Transmittance As an index of film transparency, the total light transmittance was measured with a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., Model NDH7000).

(4) Surface Smoothness of Film The surface smoothness of the film was evaluated by visual inspection. Films with little surface roughness were marked with ◯, and films with much roughness were marked with ×.

[Example 1]
As the resin composition (A), a resin composition having the following composition was used.

(Resin composition (A))
2 parts by mass of ethylene-vinyl acetate copolymer (a1-25) having a vinyl acetate content of 25% by mass and a melt mass flow rate of 3.0 g/10 min (manufactured by Tosoh Corporation, product name Ultrathene 640) Vinyl acetate content 1 part by mass of ethylene-vinyl acetate copolymer (a1-50) (manufactured by LANXESS AG, product name Levaprene 500) having a vinyl acetate content of 80% by mass and a melt mass flow rate of 3.0 g/10 min 1 part by mass of ethylene-vinyl acetate copolymer (a1-80) (manufactured by LANXESS AG, product name Levaprene 800) having a mass flow rate of 5.0 g/10 min. Styrene-ethylene-butylene-styrene block copolymer (a2 -13) (KRATON, styrene content 13% by mass, product name G1657VS) 1 part by mass

The resin composition was dry blended and melt-kneaded using a twin-screw extruder (manufactured by Technovel, product name ULT nano 25TW) with a screw diameter of 25 mm at a resin temperature of 160°C and a screw rotation speed of 150 rpm to obtain pellets of resin composition (A).

The following resin was used as the thermoplastic resin (B) containing at least polyolefin and polyester:

(Thermoplastic resin (B))
Linear low-density polyethylene (manufactured by Tosoh, MFR 2.0 g/10 min, product name Nipolon Z HF210K) 90 parts by mass Polyethylene terephthalate (manufactured by Unitika, product name MA-2103) 10 parts by mass

The above resins were dry blended to obtain thermoplastic resin (B).

Five parts by mass of resin composition (A) and 100 parts by mass of thermoplastic resin (B) were pre-blended in a tumbler mixer. Next, using a twin-screw extruder (manufactured by Technovel, product name ULT nano 25TW) with a screw diameter of 25 mm, the mixture was melt-mixed at a resin temperature of 260°C and a screw rotation speed of 300 rpm. After melt mixing, the mixture was cooled to room temperature to obtain resin composition pellets (molten mixture). The MFR of the resin composition was 3.0 g/10 min.

A single-layer film made of the resin composition pellets was obtained using a microcast molding machine (manufactured by Labtech Engineering).

The molding temperature was 200°C, the take-up speed was 2 m/min, the film width was 50 mm, and the total film thickness was 50 μm.

The number of fisheyes that occurred in the obtained film, as well as the total light transmittance and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Example 2]
A single layer film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition (A). The MFR of the resin composition was 3.0 g/10 min.

(Resin composition (A))
2 parts by mass of ethylene-vinyl acetate copolymer (a1-25) having a vinyl acetate content of 25% by mass and a melt mass flow rate of 3.0 g/10 min (manufactured by Tosoh Corporation, product name Ultrathene 640) Vinyl acetate content 1 part by mass of ethylene-vinyl acetate copolymer (a1-50) (manufactured by LANXESS AG, product name Levaprene 500) having a vinyl acetate content of 80% by mass and a melt mass flow rate of 3.0 g/10 min 1 part by mass of ethylene-vinyl acetate copolymer (a1-80) (manufactured by LANXESS AG, product name Levaprene 800) having a mass flow rate of 5.0 g/10 min. Styrene-ethylene-butylene-styrene block copolymer (a2 -30) (KRATON, styrene content 30% by mass, product name G1726MS) 1 part by mass

The number of fisheyes that occurred in the obtained film, as well as the total light transmittance and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Example 3]
A single layer film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition (A). The MFR of the resin composition was 3.0 g/10 min.
(Resin composition (A))
Ethylene-vinyl acetate copolymer (a1-25) having a vinyl acetate content of 25% by mass and a melt mass flow rate of 3.0 g/10 min (manufactured by Tosoh Corporation, product name Ultrasen 640) 1.5 parts by mass Ethylene-vinyl acetate copolymer (a1-50) having a vinyl acetate content of 50% by mass and a melt mass flow rate of 3.0 g/10 min (manufactured by Lanxess Co., Ltd., product name Levaprene 500) 0.75 parts by mass Ethylene-vinyl acetate copolymer (a1-80) having a vinyl acetate content of 80% by mass and a melt mass flow rate of 5.0 g/10 min (manufactured by Lanxess Co., Ltd., product name Levaprene 800) 0.75 parts by mass Styrene-ethylene butylene-styrene block copolymer (a2-30) (manufactured by KRATON, styrene content 30% by mass, product name G1726MS) 2 parts by mass

The number of fisheyes that occurred in the obtained film, total light transmittance, and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Comparative Example 1]
A monolayer film was obtained in the same manner as in Example 1, except that 100 parts by mass of a composite resin prepared by dry blending 90 parts by mass of linear low-density polyethylene (manufactured by Tosoh, MFR 2.0 g/10 min, product name Nipolon Z HF210K) and 10 parts by mass of polyethylene terephthalate (manufactured by Unitika, product name MA-2103) was used as the thermoplastic resin (B) containing at least polyolefin and polyester. The MFR of the resin composition was 3.0 g/10 min.

The number of fisheyes that occurred in the obtained film, total light transmittance, and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Comparative Example 2]
A single layer film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition (A). The MFR of the resin composition was 3.0 g/10 min.
(Resin composition (A))
5 parts by mass of ethylene-vinyl acetate copolymer (a1-25) having a vinyl acetate content of 25% by mass and a melt mass flow rate of 3.0 g/10 min (manufactured by Tosoh Corporation, product name Ultrathene 640)

The number of fisheyes that occurred in the obtained film, as well as the total light transmittance and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Comparative Example 3]
A single layer film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition (A). The MFR of the resin composition was 3.0 g/10 min.

(Resin composition (A))
2.5 parts by mass of ethylene-vinyl acetate copolymer (a1-25) having a vinyl acetate content of 25% by mass and a melt mass flow rate of 3.0 g/10 min (manufactured by Tosoh Corporation, product name Ultrathene 640) 1.25 parts by mass of ethylene-vinyl acetate copolymer (a1-50) having a vinyl content of 50% by mass and a melt mass flow rate of 3.0 g/10 min (manufactured by LANXESS AG, product name Levaprene 500) 1.25 parts by mass of ethylene-vinyl acetate copolymer (a1-80) (manufactured by LANXESS AG, product name Levaprene 800) having a melt mass flow rate of 5.0 g/10 min

The number of fisheyes that occurred in the obtained film, as well as the total light transmittance and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Comparative Example 4]
A single layer film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition (A). The MFR of the resin composition was 3.0 g/10 min.
(Resin composition (A))
Styrene-ethylene-butylene-styrene block copolymer (a2-13) (manufactured by KRATON, styrene content 13% by mass, product name G1657VS) 5 parts by mass

The number of fisheyes that occurred in the obtained film, as well as the total light transmittance and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Comparative Example 5]
A single layer film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition (A). The MFR of the resin composition was 3.0 g/10 min.

(Resin composition (A))
Styrene-ethylene-butylene-styrene block copolymer (a2-30) (manufactured by KRATON, styrene content 30% by mass, product name G1726MS) 5 parts by mass

The number of fisheyes that occurred in the obtained film, total light transmittance, and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Comparative Example 6]
A single layer film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition (A). The MFR of the resin composition was 3.0 g/10 min.

(Resin composition (A))
4 parts by mass of ethylene-vinyl acetate copolymer (a1-25) (product name Ultrathene 640, manufactured by Tosoh Corporation) having a vinyl acetate content of 25% by mass and a melt mass flow rate of 3.0 g/10 min. Styrene-ethylene Butylene-styrene block copolymer (a2-13) (manufactured by KRATON, styrene content 13% by mass, product name G1657VS) 1 part by mass

The number of fisheyes that occurred in the obtained film, as well as the total light transmittance and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

[Comparative Example 7]
A single layer film was obtained in the same manner as in Example 1, except that a resin composition having the following composition was used as the resin composition (A). The MFR of the resin composition was 3.0 g/10 min.

(Resin composition (A))
4 parts by mass of ethylene-vinyl acetate copolymer (a1-25) (product name Ultrathene 640, manufactured by Tosoh Corporation) having a vinyl acetate content of 25% by mass and a melt mass flow rate of 3.0 g/10 min. Styrene-ethylene Butylene-styrene block copolymer (a2-30) (manufactured by KRATON, styrene content 30% by mass, product name G1726MS) 1 part by mass

The number of fisheyes that occurred in the obtained film, as well as the total light transmittance and film surface smoothness were measured using the evaluation methods described above. The evaluation results are shown in Table 1.

As shown in Table 1, the films of Examples 1 to 3 had two or less fisheyes, confirming that the occurrence of fisheyes was suppressed. In addition, it was confirmed that the surface smoothness was good and the film appearance was excellent.

Films made from the resin composition of the present invention are useful as packaging containers for food, daily necessities, industrial parts, pharmaceuticals, office supplies, chemical products, etc., surface protection films, agricultural films such as silage wrap, shrink films, transport bags, etc.

Claims (15)

Resin composition (A) containing 50 parts by mass or more and 99 parts by mass or less of composition (a1) containing at least two types of ethylene-vinyl acetate copolymers with different vinyl acetate contents, and 1 part by mass or more and 50 parts by mass or less of styrene-based block copolymer (a2) (wherein the sum of (a1) and (a2) is 100 parts by mass). The resin composition (A) according to claim 1, in which the vinyl acetate content of each ethylene-vinyl acetate copolymer contained in the composition (a1) containing an ethylene-vinyl acetate copolymer is 6% by mass or more and 90% by mass or less. The resin composition (A) according to claim 1, wherein the composition (a1) containing an ethylene-vinyl acetate copolymer contains three or more types of ethylene-vinyl acetate copolymers having different vinyl acetate contents. The resin composition (A) according to claim 1, in which the difference in vinyl acetate content of each ethylene-vinyl acetate copolymer in the ethylene-vinyl acetate copolymer composition (a1) is 1% by mass or more, and further the difference in vinyl acetate content of at least one pair of ethylene-vinyl acetate copolymers is 40% by mass or less. The resin composition (A) according to claim 1, wherein the styrene-based block copolymer (a2) is a block copolymer having at least one polymer block mainly composed of styrene monomer units and at least one polymer block mainly composed of conjugated diene compound monomer units, or a hydrogenated product thereof. The resin composition (A) according to claim 1, wherein the styrene-based block copolymer (a2) is a styrene-butadiene-styrene block copolymer (SBS), a styrene-isoprene-styrene block copolymer (SIS), or a hydrogenated product thereof. The resin composition (A) according to claim 1, wherein the styrene-based block copolymer (a2) is a styrene-ethylene-butylene-styrene block copolymer (SEBS). The resin composition (A) according to claim 7, in which the styrene block ratio of the styrene-ethylene-butylene-styrene block copolymer (SEBS) is 10% by mass or more and 50% by mass or less. A resin compatibilizer comprising the resin composition (A) according to any one of claims 1 to 8. A thermoplastic resin composition comprising the resin composition (A) according to claim 1 and a thermoplastic resin (B) containing a polyolefin and a polyester,
A resin composition comprising 1 part by mass or more and 15 parts by mass or less of a resin composition (A) relative to 100 parts by mass of a thermoplastic resin (B). The resin composition according to claim 10, wherein the polyester is polyethylene terephthalate. The resin composition according to claim 10, wherein the resin contained in the thermoplastic resin (B) is a resin obtained by recovering plastic waste. A molded article made of the resin composition according to any one of claims 10 to 12. A film made of the resin composition according to any one of claims 10 to 12. A packaging container made of the film described in claim 14.