Antistatic resin composition, resin film, and semiconductor manufacturing process film

Abstract

This resin composition comprises: (A) at least one ethylene-based resin selected from the group consisting of ethylene-unsaturated carboxylic acid copolymers, ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymers, ionomers of ethylene-unsaturated carboxylic acid copolymers, and ionomers of ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymers; (B) a propylene-based soft polyolefin; (C) an acid-modified polyolefin; and (D) a block copolymer of propylene and a polyhydric alcohol. The melting point of the propylene-based soft polyolefin (B) may be 60-115°C. The absolute value of the difference between the crystallization temperature of the ethylene-based resin (A) and the crystallization temperature of the propylene-based soft polyolefin (B) may be 20°C or lower. The acid-modified polyolefin (C) may include an acid-modified polyethylene.

Description

Antistatic resin composition, resin film, and film for semiconductor manufacturing process

[0001] The present invention relates to a resin composition having antistatic properties, a resin film including a layer formed from the resin composition, and a film for use in semiconductor manufacturing processes that uses the resin film as a film substrate.

[0002] Semiconductor chips are produced by forming a large number of chips together on a large-diameter silicon wafer, polishing the silicon wafer from its backside (the side opposite to the side on which the circuits are formed (circuit side)) to the desired thickness, and then dicing (cutting and separating) into individual semiconductor chips. This silicon wafer polishing process is often carried out after laminating an adhesive film (hereinafter referred to as a "backgrinding film") to the circuit side of the silicon wafer for the purpose of protecting the circuit side of the silicon wafer. This dicing process into individual semiconductor chips is often carried out after laminating an adhesive film (hereinafter referred to as a "dicing film") on the circuit side and / or backside of the silicon wafer for the purpose of protecting the surface of the semiconductor chips and fixing and picking up the individual cut semiconductor chips. Furthermore, an adhesive film (hereinafter referred to as a "die attach film") is often used to adhesively stack and mount semiconductor chips on a substrate. Thus, many types of adhesive films are used in the semiconductor manufacturing process.

[0003] In recent years, semiconductor chips have become smaller and thinner due to miniaturization of transistor structures and increased density of three-dimensional interconnect structures. This has led to increased susceptibility to problems caused by static electricity generated during dicing and other operations, such as damage to semiconductor chip circuits. Therefore, it has been proposed to impart antistatic properties to semiconductor manufacturing process films and film substrates for semiconductor manufacturing process films (see, for example, Patent Documents 1 to 3). However, these techniques require the incorporation of large amounts of antistatic agents to achieve sufficient antistatic properties. As a result, there have been problems such as the antistatic agent contaminating the metal rolls of the film-forming equipment during film formation (hereinafter, this problem may be referred to as "plate-out"). Furthermore, the antistatic agent contaminating the metal rolls of the film-forming equipment is transferred to the film substrate, thereby reducing the properties of the adhesive layer formed on the film substrate. Therefore, the present applicant proposed the technology described in Patent Document 4. However, from the perspective of efficient long-run production of large lots of film substrates, further suppression of plate-out is desired.

[0004] JP 2008-244377 A JP 2011-210887 A JP 2017-098369 A WO 2022 / 064949

[0005] The object of the present invention is to provide a resin composition that has antistatic properties and that suppresses the inconvenience of the antistatic agent contaminating the metal roll of a film-forming device during film formation; a resin film that includes a layer formed from the resin composition; and a film for semiconductor manufacturing processes that uses the resin film as a film substrate.

[0006] As a result of extensive research, the present inventors have found that the above object can be achieved by using a specific resin composition.

[0007] That is, the various aspects or embodiments of the present invention are as follows. [1] A resin composition comprising: (A) 18 to 97% by mass of at least one ethylene-based resin selected from the group consisting of an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, an ionomer of an ethylene-unsaturated carboxylic acid copolymer, and an ionomer of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer; (B) 1 to 40% by mass of a propylene-based flexible polyolefin; (C) 1 to 16% by mass of an acid-modified polyolefin; and (D) 1 to 26% by mass of a block copolymer of propylene and a polyhydric alcohol, wherein the sum of the blend amounts of the (A) ethylene-based resin, (B) the propylene-based flexible polyolefin, (C) the acid-modified polyolefin, and (D) the block copolymer of propylene and a polyhydric alcohol is 100% by mass. [2] A resin composition according to the above item [1], wherein the melting point of the (B) propylene-based flexible polyolefin is 60 to 115°C. [3]. The resin composition according to [2] above, wherein the absolute value of the difference between the crystallization temperature of (A) the ethylene-based resin and the crystallization temperature of (B) the propylene-based flexible polyolefin is 20°C or less. [4]. The resin composition according to [1] above, wherein the (C) acid-modified polyolefin comprises an acid-modified polyethylene. [5]. The resin composition according to [1] above, wherein the mass ratio of the blended amount of (B) the propylene-based flexible polyolefin to the blended amount of (D) the block copolymer of propylene and a polyhydric alcohol is 0.4 to 10. [6]. A resin film having, as at least one layer component, a layer formed from the resin composition according to any one of [1] to [5] above. [7]. The resin film according to [6] above, which is used as a film substrate for a semiconductor manufacturing process film. [8]. A semiconductor manufacturing process film comprising the resin film according to [6] above.

[0008] The resin composition of the present invention has antistatic properties and suppresses plate-out during film formation. A preferred resin composition of the present invention has sufficient antistatic properties, sufficiently suppresses plate-out during film formation, and a resin film containing a layer formed therefrom has excellent expandability. Here, excellent expandability generally refers to having tensile properties suitable for the expanding process (a process in which, after cutting a silicon wafer, the dicing film is pulled to increase the distance between individual semiconductor chips to make them easier to pick up). Therefore, a resin film containing a layer formed using the resin composition of the present invention can be suitably used as a film substrate for semiconductor manufacturing process films, such as dicing films, backgrinding films, and die attach films, and is particularly suitable as a film substrate for semiconductor manufacturing process films used in the production of small, thin semiconductor chips.

[0009] 1 is a DSC measurement example of (B-1) propylene-based flexible polyolefin used in the examples. 2 is a conceptual diagram of a film-forming apparatus used in the examples.

[0010] In this specification, the term "resin" is used to include a resin mixture containing two or more resins, and a resin composition containing components other than resin.

[0011] In this specification, the term "film" is used interchangeably or interchangeably with "sheet." In this specification, the terms "film" and "sheet" are used to refer to materials that can be industrially wound into rolls. The term "plate" is used to refer to materials that cannot be industrially wound into rolls. In addition, in this specification, laminating one layer and another layer in order includes both directly laminating the layers and laminating the layers with one or more additional layers, such as an anchor coat, interposed between them.

[0012] In this specification, the term "equivalent to or greater than" in relation to a numerical range means a certain numerical value or more than a certain numerical value. For example, 20% or greater means 20% or more than 20%. The term "equal to or less than" in relation to a numerical range means a certain numerical value or less than a certain numerical value. For example, 20% or less means 20% or less than 20%. Furthermore, the symbol "to" in relation to a numerical range means a certain numerical value, more than a certain numerical value and less than another certain numerical value, or another certain numerical value. Here, the other certain numerical value is a number greater than the certain numerical value. For example, 10 to 90% means 10%, more than 10% and less than 90%, or 90%. Furthermore, the upper and lower limits of a numerical range can be arbitrarily combined, and embodiments incorporating any combination can be interpreted. For example, from a statement regarding the numerical range of a certain characteristic such as "usually 10% or more, preferably 20% or more. On the other hand, it is usually 40% or less, preferably 30% or less," or "usually 10 to 40%, preferably 20 to 30%," it can be read that the numerical range of the certain characteristic is 10 to 40%, 20 to 30%, 10 to 30%, or 20 to 40% in one embodiment.

[0013] Other than in the examples, or where otherwise specified, all numerical values ​​used in the specification and claims should be understood to be modified by the term "about." Without attempting to limit the application of the doctrine of equivalents to the claims, each numerical value should be construed in light of the number of significant digits and by applying ordinary rounding techniques.

[0014] In this specification, terms specifying shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are intended to include not only the strict meanings but also substantially the same states.

[0015] In this specification, when it is explained that "comprises a certain substance," it is to be understood that, in one embodiment, it contains a certain substance, consists of a certain substance, or consists only of a certain substance. For example, from the explanation that "composition A comprises substance a1 and substance a2," it is to be understood that, in one embodiment, composition A comprises substance a1 and substance a2, composition A consists of substance a1 and substance a2, or composition A consists only of substance a1 and substance a2.

[0016] 1. Resin Composition In one embodiment, the resin composition of the present invention comprises (A) at least one ethylene-based resin selected from the group consisting of an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, an ionomer of an ethylene-unsaturated carboxylic acid copolymer, and an ionomer of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, (B) a propylene-based flexible polyolefin, (C) an acid-modified polyolefin, and (D) a block copolymer of propylene and a polyhydric alcohol. The amounts of the components (A), (B), (C), and (D) are not particularly limited and may be appropriately adjusted to impart desired properties. In a preferred embodiment, the resin composition of the present invention comprises 18 to 97% by mass of at least one ethylene-based resin selected from the group consisting of an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, an ionomer of an ethylene-unsaturated carboxylic acid copolymer, and an ionomer of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, (B) 1 to 40% by mass of a propylene-based flexible polyolefin, (C) 1 to 16% by mass of an acid-modified polyolefin, and (D) 1 to 26% by mass of a block copolymer of propylene and a polyhydric alcohol, provided that the total amount of the ethylene-based resin, (B) the propylene-based flexible polyolefin, (C) the acid-modified polyolefin, and (D) the block copolymer of propylene and a polyhydric alcohol is 100% by mass. Each component will be described below.

[0017] (A) Ethylene-Based Resin The resin composition of the present invention contains (A) at least one ethylene-based resin selected from the group consisting of an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, an ionomer of an ethylene-unsaturated carboxylic acid copolymer, and an ionomer of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer. The (A) ethylene-based resin functions to improve the expandability of the resin film.

[0018] The unsaturated carboxylic acid that can be used as a constituent monomer of the (A) ethylene-based resin is a compound having one or more carbon-carbon double bonds and one or more carboxyl groups (including acid anhydrides) per molecule. Examples of such unsaturated carboxylic acids include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, and crotonic acid; unsaturated dicarboxylic acids such as itaconic acid, fumaric acid, and maleic acid; unsaturated dicarboxylic acid monoesters such as maleic acid monoesters, fumaric acid monoesters, and itaconic acid monoesters; and unsaturated dicarboxylic acid anhydrides such as maleic anhydride and itaconic anhydride. When an unsaturated carboxylic acid has two or more carboxyl groups, even if some of the carboxyl groups are esterified, if the other carboxyl groups remain unesterified, it is classified as an "unsaturated carboxylic acid" rather than an "unsaturated carboxylic acid ester." The unsaturated carboxylic acid may preferably contain an unsaturated monocarboxylic acid, more preferably one or more selected from the group consisting of acrylic acid and methacrylic acid. As the unsaturated carboxylic acid, one of these or a mixture of two or more thereof can be used.

[0019] The unsaturated carboxylic acid ester that can be used as a constituent monomer of the (A) ethylene-based resin is a compound in which all carboxyl groups of the unsaturated carboxylic acid are esterified. Examples of the unsaturated carboxylic acid ester include alkyl acrylates such as methyl acrylate, ethyl acrylate, and butyl acrylate; unsaturated monocarboxylic acid monoalkyl esters such as alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; and unsaturated dicarboxylic acid dialkyl esters such as dialkyl maleates such as dimethyl maleate and diethyl maleate. The unsaturated carboxylic acid ester may preferably include one or more selected from the group consisting of alkyl acrylates and alkyl methacrylates. The unsaturated carboxylic acid ester may be one or a mixture of two or more of these.

[0020] Examples of the ethylene-unsaturated carboxylic acid copolymer include an ethylene-acrylic acid copolymer and an ethylene-methacrylic acid copolymer. In a preferred embodiment, the ethylene-unsaturated carboxylic acid copolymer may be an ethylene-methacrylic acid copolymer.

[0021] Examples of the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer include ethylene-methacrylic acid-methacrylic acid alkyl ester copolymers such as ethylene-methacrylic acid-ethyl methacrylate copolymer, ethylene-methacrylic acid-acrylic acid alkyl ester copolymers such as ethylene-methacrylic acid-butyl acrylate copolymer, ethylene-acrylic acid-methacrylic acid alkyl ester copolymers such as ethylene-acrylic acid-ethyl methacrylate copolymer, and ethylene-acrylic acid-acrylic acid alkyl ester copolymers such as ethylene-acrylic acid-butyl acrylate copolymer.

[0022] The ionomer of the ethylene-unsaturated carboxylic acid copolymer is one in which some or all of the carboxyl groups of the ethylene-unsaturated carboxylic acid copolymer are neutralized with metal ions.The ionomer of the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer is one in which some or all of the carboxyl groups of the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer are neutralized with metal ions.

[0023] Examples of the metal ions that can be used in the ionomer of the ethylene-unsaturated carboxylic acid copolymer and the ionomer of the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer include lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, zinc ions, magnesium ions, and manganese ions. Among these, the metal ions may preferably include one or more selected from the group consisting of magnesium ions, sodium ions, and zinc ions, and more preferably include one or more selected from the group consisting of sodium ions and zinc ions.

[0024] The content of the ethylene-derived structural units in the (A) ethylene-based resin can be appropriately selected from the viewpoint of the expandability and blocking resistance of the resin film formed from the resin composition. From the viewpoint of the expandability of the resin film, the content of the ethylene-derived structural units in the (A) ethylene-based resin may be preferably 98% by mass or less, more preferably 96% by mass or less, and even more preferably 94% by mass or less. On the other hand, from the viewpoint of the blocking resistance of the resin film, this content may usually be 70% by mass or more, preferably 74% by mass or more, and more preferably 78% by mass or more. In one embodiment, the content of structural units derived from ethylene in the (A) ethylene-based resin may typically be 70% by mass or more and 98% by mass or less, and preferably 70% by mass or more and 96% by mass or less, 70% by mass or more and 94% by mass or less, 74% by mass or more and 98% by mass or less, 74% by mass or more and 96% by mass or less, 74% by mass or more and 94% by mass or less, 78% by mass or more and 98% by mass or less, 78% by mass or more and 96% by mass or less, or 78% by mass or more and 94% by mass or less.

[0025] The melting point of the (A) ethylene-based resin may be preferably 60° C. or higher, more preferably 70° C. or higher, even more preferably 75° C. or higher, and most preferably 80° C. or higher, from the viewpoint of the blocking resistance of the resin film formed from the resin composition. On the other hand, the melting point of the (A) ethylene-based resin may be preferably 115° C. or lower, more preferably 110° C. or lower, even more preferably 105° C. or lower, and most preferably 100° C. or lower, from the viewpoint of the expandability of the resin film. In one embodiment, the melting point of the (A) ethylene-based resin may be preferably 60°C or higher and 115°C or lower, more preferably 60°C or higher and 110°C or lower, 60°C or higher and 105°C or lower, 60°C or higher and 100°C or lower, 70°C or higher and 115°C or lower, 70°C or higher and 110°C or lower, 70°C or higher and 105°C or lower, 70°C or higher and 100°C or lower, 75°C or higher and 115°C or lower, 75°C or higher and 110°C or lower, 75°C or higher and 105°C or lower, 75°C or higher and 100°C or lower, 80°C or higher and 115°C or lower, 80°C or higher and 110°C or lower, 80°C or higher and 105°C or lower, or 80°C or higher and 100°C or lower.

[0026] In this specification, the crystallization temperature and melting point of (A) ethylene-based resin are measured by the following method. First, in accordance with JIS K7121-1987, a differential scanning calorimeter (DSC measuring apparatus) is used to measure a DSC crystallization curve and a DSC second melting curve (a melting curve measured during the final heating process) using a program in which a sample is held at 230°C for 5 minutes, cooled to -50°C at 10°C / min, held at -50°C for 5 minutes, and heated to 230°C at 10°C / min. The crystallization temperature is the peak-top temperature of the crystallization peak appearing in the DSC crystallization curve. When two or more crystallization peaks are observed, the peak-top temperature of the crystallization peak with the greatest peak-top height is taken as the crystallization temperature. The melting point is the peak-top temperature of the melting peak appearing in the DSC second melting curve. When two or more melting peaks are observed, the peak-top temperature of the melting peak with the greatest peak-top height is taken as the melting point.

[0027] The melt mass flow rate of the (A) ethylene-based resin, measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 21.18 N, may be preferably 0.05 to 20 g / 10 min, more preferably 0.1 to 15 g / 10 min, and even more preferably 0.5 to 10 g / 10 min, from the viewpoint of film-forming properties of the resin composition.

[0028] The ethylene-based resin (A) can be one of these or a mixture of two or more of them. When a mixture of two or more of them is used as the ethylene-based resin (A), it goes without saying that the properties of the mixture should be determined by measuring the properties of the mixture.

[0029] (B) Flexible Propylene-Based Polyolefin The resin composition of the present invention contains (B) a flexible propylene-based polyolefin, which suppresses plate-out of (D) a block copolymer of propylene and a polyhydric alcohol during film formation and aids in the antistatic effect of (D).

[0030] (B) Propylene-based flexible polyolefin is a resin that mainly contains structural units derived from propylene and has amorphous or low crystallinity. Here, "having amorphous or low crystallinity" means that no melting peak is observed in the DSC second melting curve (the measurement method will be described later) or that the melting point is 120°C or lower. Here, "mainly containing structural units derived from propylene" means that the content of structural units derived from propylene is 50 to 100 mol% relative to 100 mol% of all structural units of the propylene-based flexible polyolefin. Here, compounds corresponding to (D) block copolymers of propylene and polyhydric alcohols are excluded from (B) propylene-based flexible polyolefin.

[0031] The (B) propylene-based flexible polyolefin may preferably have a melting point from the viewpoint of the heat resistance and solvent resistance of the resin film formed from the resin composition. In this case, the melting point of the (B) propylene-based flexible polyolefin may be preferably 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher from the viewpoint of the heat resistance and solvent resistance of the resin film formed from the resin composition. On the other hand, the melting point of the (B) propylene-based flexible polyolefin may be preferably 115°C or lower, more preferably 110°C or lower, even more preferably 105°C or lower, and most preferably 100°C or lower from the viewpoint of the flexibility and expandability of the resin film formed from the resin composition. In one embodiment, the melting point of the (B) propylene-based flexible polyolefin may preferably be 60°C or higher and 115°C or lower, more preferably 60°C or higher and 110°C or lower, 60°C or higher and 105°C or lower, 60°C or higher and 100°C or lower, 70°C or higher and 115°C or lower, 70°C or higher and 110°C or lower, 70°C or higher and 105°C or lower, 70°C or higher and 100°C or lower, 80°C or higher and 115°C or lower, 80°C or higher and 110°C or lower, 80°C or higher and 105°C or lower, or 80°C or higher and 100°C or lower.

[0032] The absolute value (unit: °C) of the difference between the crystallization temperature of the (A) ethylene-based resin and the (B) propylene-based soft polyolefin may be preferably 30°C or lower, more preferably 20°C or lower, even more preferably 10°C, and most preferably 0 to 5°C, from the viewpoint of the function of supporting the antistatic property-imparting effect of the (D) block copolymer of propylene and a polyhydric alcohol in the (B) propylene-based soft polyolefin.

[0033] Without intending to be bound by theory, the reason why a small difference in crystallization temperature between the (A) ethylene-based resin and the (B) propylene-based soft polyolefin is preferable from the viewpoint of the function of (B) propylene-based soft polyolefin in supporting the antistatic effect of the (D) propylene-polyol block copolymer is considered as follows: The propylene polymer segment of the (D) propylene-polyol block copolymer is solidified in a state of being compatible with the (B) propylene-based soft polyolefin, and the polyol polymer segment may be present in the vicinity thereof (in the propylene polymer islands or sea). Therefore, the shape / morphology of the (B) propylene-based soft polyolefin or the propylene polymer islands or sea may affect the antistatic effect of the (D) propylene-polyol block copolymer. When the difference in crystallization temperature between (A) the ethylene-based resin and (B) the propylene-based flexible polyolefin is small, they are compatible with each other in a molten state, and this can result in a morphology in which seas (or islands) of ethylene polymers and islands (or seas) of propylene polymers are mixed together. As a result, the islands (or seas) of propylene polymers tend to be adjacent and continuous, which can enhance the above-mentioned auxiliary effect.

[0034] In one embodiment, the content of structural units derived from propylene in (B) the flexible propylene-based polyolefin may be preferably 60 mol% or more, 70 mol% or more, 80 mol% or more, or 90 to 100 mol% relative to 100 mol% of all structural units in the flexible propylene-based polyolefin.

[0035] In this specification, the crystallization temperature and melting point of (B) propylene-based soft polyolefin are measured by the following method. First, in accordance with JIS K7121-1987, a differential scanning calorimeter (DSC measuring apparatus) is used to measure a DSC crystallization curve and a DSC second melting curve (a melting curve measured during the final heating process) using a program in which a sample is held at 230°C for 5 minutes, cooled to -50°C at 10°C / min, held at -50°C for 5 minutes, and heated to 230°C at 10°C / min. The crystallization temperature is the peak-top temperature of the crystallization peak appearing in the DSC crystallization curve. When two or more crystallization peaks are observed, the peak-top temperature of the crystallization peak with the greatest peak-top height is taken as the crystallization temperature. The melting point is the peak-top temperature of the melting peak appearing in the DSC second melting curve. When two or more melting peaks are observed, the peak-top temperature of the melting peak with the greatest peak-top height is taken as the melting point. Figure 1 shows an example of DSC measurement of the following component (B-1), a propylene-based soft polyolefin, used in the examples. The lower curve in Figure 1 is the DSC second melting curve, and the upper curve is the DSC crystallization curve. The following points should be noted during measurement: (1) the melting peak appearing in the DSC second melting curve of a propylene-based soft polyolefin usually has a gently extending long tail on the low-temperature side; (2) the high-temperature side often also has a gently extending long tail; and (3) the baseline should be drawn so that the line extending the high-temperature side baseline toward the low-temperature side in Figure 1 of JIS K7121-1987, Section 9, "How to read DTA or DSC curves," coincides with the line extending the same low-temperature side baseline toward the high-temperature side.

[0036] As the (B) propylene-based soft polyolefin, one having the above-mentioned properties can be appropriately selected and used.

[0037] Examples of the propylene-based flexible polyolefin (B) having the above-mentioned properties include atactic polypropylene and copolymers (including random copolymers and block copolymers) of propylene with one or more of other α-olefins (e.g., ethylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene).

[0038] The melt mass flow rate of the propylene-based soft polyolefin (B), measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 230°C and a load of 21.18 N, may be preferably 0.1 to 50 g / 10 min, more preferably 1 to 40 g / 10 min, and even more preferably 3 to 30 g / 10 min, from the viewpoint of film-forming properties of the resin composition.

[0039] The melt mass flow rate of the propylene-based soft polyolefin (B), measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 21.18 N, may be preferably 0.05 to 20 g / 10 min, more preferably 0.1 to 15 g / 10 min, and even more preferably 0.5 to 10 g / 10 min, from the viewpoint of film-forming properties of the resin composition.

[0040] The propylene-based flexible polyolefin (B) can be one of these or a mixture of two or more of them. When a mixture of two or more of them is used as the propylene-based flexible polyolefin (B), it goes without saying that the properties of the mixture should be determined by measuring the mixture.

[0041] (C) Acid-Modified Polyolefin The resin composition of the present invention contains (C) an acid-modified polyolefin, which serves to suppress plate-out of (D) a block copolymer of propylene and a polyhydric alcohol during film formation.

[0042] (C) Acid-modified polyolefin is a resin obtained by modifying a polyolefin with an unsaturated carboxylic acid (usually by graft polymerizing the unsaturated carboxylic acid onto the polyolefin).

[0043] Examples of the polyolefins that can be used in the production of (C) acid-modified polyolefin include polyethylenes such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), very low-density polyethylene (VLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and ethylene-α-olefin (e.g., propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, etc.) copolymers (including random copolymers and block copolymers); polypropylenes such as propylene homopolymers and propylene-α-olefin (e.g., ethylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, etc.) copolymers (including random copolymers and block copolymers); polybutene, and polypentene. The polyolefins may preferably contain polyethylenes such as those exemplified above. The polyolefins may be one or a mixture of two or more of these.

[0044] The unsaturated carboxylic acid that can be used to produce (C) acid-modified polyolefin is a compound having one or more carbon-carbon double bonds and one or more carboxyl groups (including acid anhydrides) in one molecule. Examples of the unsaturated carboxylic acid include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, and crotonic acid; unsaturated dicarboxylic acids such as itaconic acid, fumaric acid, and maleic acid; unsaturated dicarboxylic acid monoesters such as maleic acid monoester, fumaric acid monoester, and itaconic acid monoester; and unsaturated dicarboxylic acid anhydrides such as maleic anhydride and itaconic anhydride. The unsaturated carboxylic acid may preferably contain an unsaturated dicarboxylic acid anhydride, more preferably contain maleic anhydride. The unsaturated carboxylic acid may be one or a mixture of two or more of these.

[0045] The (C) acid-modified polyolefin may preferably contain an acid-modified polyethylene, more preferably contain an unsaturated dicarboxylic acid anhydride-modified polyethylene, and even more preferably contain a maleic anhydride-modified polyethylene.

[0046] (A) Ethylene-based resin and (C) acid-modified polyolefin, which are resins obtained by modifying polyethylene, are clearly distinguished in that, in the (A) ethylene-based resin, the structural unit derived from the unsaturated carboxylic acid is usually present only in the main chain and is not grafted, whereas in the (C) acid-modified polyolefin, the structural unit is usually grafted.

[0047] (C) Acid-modified polyolefins are resins obtained by modifying polypropylene as exemplified above, and have structural units derived from unsaturated carboxylic acids, whereas (B) propylene-based flexible polyolefins do not have structural units derived from unsaturated carboxylic acids, and thus the two are clearly distinguished from each other.

[0048] Without intending to be bound by theory, the reason why (A) ethylene-based resins do not suppress plate-out of (D) propylene and polyhydric alcohol block copolymers during film formation, while (C) acid-modified polyolefins do, is considered as follows: The carboxyl groups (including acid anhydrides) of the structural units derived from unsaturated carboxylic acids are capable of strong interaction with the polyhydric alcohol polymerized segments of (D) propylene and polyhydric alcohol block copolymers. However, in (A) ethylene-based resins, structural units derived from unsaturated carboxylic acids are typically present only in the main chain, and therefore, adjacent structural units derived from ethylene act as obstacles to prevent strong interaction. On the other hand, in (C) acid-modified polyolefins, structural units derived from unsaturated carboxylic acids are typically grafted and are sufficiently distant from the structural units derived from olefins, so they strongly interact with the polyhydric alcohol polymerized segments of (D) propylene and polyhydric alcohol block copolymers, thereby suppressing plate-out. In particular, when the acid-modified polyolefin (C) contains the above-mentioned polyethylene (acid-modified polyethylene), the block copolymer (D) of propylene and a polyhydric alcohol strongly interacts with both the propylene polymer islands (or sea) and the ethylene polymer sea (or islands), and plate-out can be suppressed very effectively.

[0049] The acid-modified polyolefin (C) can be produced by modifying a polyolefin using an unsaturated carboxylic acid by a known method. Examples of methods for producing the acid-modified polyolefin (C) include a method of melt-kneading a blend containing, per 100 parts by mass of the polyolefin, typically 0.01 to 10 parts by mass, preferably 0.1 to 6 parts by mass, and more preferably 0.3 to 3 parts by mass of the unsaturated carboxylic acid and typically 0.01 to 5 parts by mass, preferably 0.05 to 3 parts by mass, and more preferably 0.1 to 1 part by mass of an organic peroxide, using any melt kneader. Preferably, in order to completely react the unsaturated carboxylic acid and the organic peroxide and prevent any unreacted organic peroxide from remaining in the acid-modified polyolefin (C), the blend is melt-kneaded at a temperature of at least one minute half-life temperature of the organic peroxide for at least one minute, more preferably at least two minutes at a temperature of at least one minute half-life temperature of the organic peroxide.

[0050] Examples of the organic peroxide include dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(tert-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylcumyl peroxide. From the viewpoint of manufacturability, the organic peroxide preferably contains one whose one-minute half-life temperature is slightly lower than the usual melt-kneading temperature used in producing the acid-modified polyolefin (C). Specific examples of such organic peroxides include 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane and 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexyne-3. The organic peroxide may be one of these or a mixture of two or more of them.

[0051] Examples of the melt kneader include batch kneaders such as pressure kneaders and mixers, extrusion kneaders such as single-screw extruders, co-rotating twin-screw extruders and counter-rotating twin-screw extruders, and calendar roll kneaders, etc. These may be used in any combination.

[0052] The melt mass flow rate of the acid-modified polyolefin (C), measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 230°C and a load of 21.18 N, may be preferably 0.1 to 50 g / 10 min, more preferably 1 to 40 g / 10 min, and even more preferably 3 to 30 g / 10 min, from the viewpoint of film-forming properties of the resin composition.

[0053] The melt mass flow rate of the acid-modified polyolefin (C), measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 21.18 N, may be preferably 0.05 to 20 g / 10 min, more preferably 0.1 to 15 g / 10 min, and even more preferably 0.5 to 10 g / 10 min, from the viewpoint of film-forming properties of the resin composition.

[0054] The acid-modified polyolefin (C) can be one of these or a mixture of two or more of them. When a mixture of two or more of them is used as the acid-modified polyolefin (C), it goes without saying that the properties of the mixture should be determined by measuring the properties of the mixture.

[0055] (D) Block Copolymer of Propylene and Polyhydric Alcohol The resin composition of the present invention contains (D) a block copolymer of propylene and a polyhydric alcohol. The (D) block copolymer of propylene and a polyhydric alcohol is a block copolymer having a propylene polymer segment mainly containing structural units derived from propylene and a polyhydric alcohol polymer segment mainly containing structural units derived from a polyhydric alcohol. Here, "mainly containing structural units derived from propylene" means that the content of structural units derived from propylene is usually 60% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and typically 95% by mass to 100% by mass, relative to the total mass of the propylene polymer segment. Here, "mainly containing structural units derived from polyhydric alcohol" means that the content of structural units derived from polyhydric alcohol is usually 60% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and typically 95% by mass to 100% by mass, relative to the total mass of the polyhydric alcohol polymer segment. (D) The block copolymer of propylene and polyhydric alcohol functions to impart antistatic properties.

[0056] (D) A block copolymer of propylene and a polyhydric alcohol has a polyhydric alcohol polymer segment, whereas (B) a propylene-based soft polyolefin or (C) a resin obtained by modifying polypropylene, which is an acid-modified polyolefin, does not have a polyhydric alcohol polymer segment, and therefore they are clearly distinguishable from each other.

[0057] The propylene polymer segment may be a propylene homopolymer segment, or may be a copolymer segment of propylene and one or more α-olefins (e.g., ethylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene).

[0058] Examples of the polyhydric alcohol constituting the polyhydric alcohol polymer segment include aliphatic polyhydric alcohols such as ethylene glycol, diethylene glycol, neopentyl glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol (trimethylene glycol), polypropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol (tetramethylene glycol), 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, decamethylene glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2,2,4,4'-tetramethyl-1,3-cyclobutanediol, glycerin, and trimethylolpropane. Among these, the polyhydric alcohol constituting the polyhydric alcohol polymer segment preferably contains one or more selected from the group consisting of ethylene glycol, diethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol (trimethylene glycol), and polypropylene glycol, from the viewpoint of forming a larger number of ether bonds relative to the number of carbon atoms and improving antistatic properties, and more preferably contains one or more selected from the group consisting of ethylene glycol, diethylene glycol, and polyethylene glycol.

[0059] The polyhydric alcohol polymer segment may be a polymer segment consisting only of structural units derived from a polyhydric alcohol, or may be a copolymer segment of one or more monomers copolymerizable with a polyhydric alcohol. Examples of the monomer copolymerizable with a polyhydric alcohol include compounds having two or more carboxyl groups in one molecule, such as aliphatic dicarboxylic acids, such as oxalic acid, succinic acid, adipic acid, suberic acid, and sebacic acid, and compounds having two or more isocyanate groups in one molecule, such as aliphatic diisocyanates, such as hexamethylene diisocyanate.

[0060] The amount of propylene-derived structural units in the (D) propylene and polyhydric alcohol block copolymer may be typically 30% by mass or more, preferably 40% by mass or more, and more preferably 50% by mass or more, from the viewpoint of suppressing plate-out during film formation. On the other hand, the amount of propylene-derived structural units in the (D) propylene and polyhydric alcohol block copolymer may be typically 90% by mass or less, preferably 80% by mass or less, and more preferably 70% by mass or less, from the viewpoint of antistatic properties. On the other hand, the amount of polyhydric alcohol-derived structural units in the (D) propylene and polyhydric alcohol block copolymer may be typically 70% by mass or less, preferably 60% by mass or less, and more preferably 50% by mass or less, from the viewpoint of suppressing plate-out during film formation. On the other hand, the amount of polyhydric alcohol-derived structural units in the (D) propylene and polyhydric alcohol block copolymer may be typically 10% by mass or more, preferably 20% by mass or more, and more preferably 30% by mass or more, from the viewpoint of antistatic properties. Here, the sum of the amount of propylene-derived structural units and the amount of polyhydric alcohol-derived structural units is 100% by mass.

[0061] The sum of the amount of the structural units derived from propylene and the amount of the structural units derived from polyhydric alcohol in the block copolymer of propylene and polyhydric alcohol (D) may be usually 80% by mass or more, preferably 90% by mass or more, and typically 95% by mass or more and 100% by mass or less, where the total amount of each structural unit in the block copolymer of propylene and polyhydric alcohol (D) is 100% by mass.

[0062] The block copolymer of propylene and polyhydric alcohol (D) may be doped with metal ions, thereby improving the antistatic properties.

[0063] Examples of the metal ions include lithium ions, cesium ions, rubidium ions, potassium ions, barium ions, strontium ions, calcium ions, and sodium ions. From the viewpoint of improving antistatic properties, the metal ions may preferably include lithium ions.

[0064] The content of the metal ions in the block copolymer of propylene and a polyhydric alcohol (D) may be usually 100 ppm or more, preferably 150 ppm or more, more preferably 300 ppm or more, and even more preferably 500 ppm or more from the viewpoint of improving antistatic properties, while the content of the metal ions in the block copolymer of propylene and a polyhydric alcohol (D) may be usually 2000 ppm or less, preferably 1500 ppm or less, and more preferably 1000 ppm or less from the viewpoint of suppressing plate-out.

[0065] In this specification, the content of the metal ions in the block copolymer of propylene and polyhydric alcohol (D) is measured by atomic absorption spectrometry.The measurement sample is prepared by using a microwave device, and then ashing (wet decomposition) the sample using a mixed acid of nitric acid and hydrochloric acid (volume ratio 8:2), adding an aqueous hydrochloric acid solution, filtering, and adjusting the filtrate to the specified volume with purified water.At this time (when adjusting the filtrate to the specified volume with purified water), yttrium is added as an internal standard.

[0066] The melt mass flow rate of the block copolymer of propylene and polyhydric alcohol (D), measured in accordance with JIS K7210-1:2014 at a temperature of 190°C and a load of 21.18 N, may be preferably 0.05 to 30 g / 10 min, more preferably 0.1 to 20 g / 10 min, and even more preferably 1 to 15 g / 10 min, from the viewpoint of film formability.

[0067] The melt mass flow rate of the ethylene resin (A) measured in accordance with JIS K7210-1:2014 at a temperature of 190°C and a load of 21.18 N may be lower than the melt mass flow rate of the block copolymer of propylene and polyhydric alcohol (D) measured in accordance with JIS K7210-1:2014 at a temperature of 190°C and a load of 21.18 N, and may be preferably a value lower than or equal to half the melt mass flow rate of the block copolymer of propylene and polyhydric alcohol (D).

[0068] Without intending to be bound by theory, it is considered that the polyhydric alcohol polymer segments of (D) the block copolymer of propylene and polyhydric alcohol are excluded from both the ethylene polymer sea (or islands) and the propylene polymer island (or sea), and that when the melt mass flow rates of both satisfy the above-mentioned relationship, they become elongated island phases upon receiving shear stress, making it easier to form electrical flow paths, thereby exhibiting sufficient antistatic properties.

[0069] The block copolymer of propylene and a polyhydric alcohol (D) may have a peak top of the melting peak derived from the propylene polymer segment in a second melting curve (a melting curve measured during the final heating process) measured in accordance with JIS K7121-1987 using a differential scanning calorimeter (DSC) according to a program of holding at 190°C for 5 minutes, cooling to -10°C at 10°C / min, holding at -10°C for 5 minutes, and heating to 190°C at 10°C / min, preferably in a temperature range of 100 to 165°C, more preferably in a temperature range of 120 to 160°C. Furthermore, the block copolymer of propylene and a polyhydric alcohol (D) may have a peak top of the melting peak derived from the polyhydric alcohol polymer segment in the second melting curve, preferably in a temperature range of 10 to 60°C, more preferably in a temperature range of 20 to 50°C.

[0070] The block copolymer (D) of propylene and a polyhydric alcohol may be one of these or a mixture of two or more of them. When a mixture of two or more of them is used as the block copolymer (D) of propylene and a polyhydric alcohol, it goes without saying that the properties of the mixture should be determined by measuring the properties of the mixture.

[0071] Amount of Each Component The amounts of (A) the ethylene resin, (B) the propylene-based soft polyolefin, (C) the acid-modified polyolefin, and (D) the block copolymer of propylene and polyhydric alcohol are described below, where the total amount of (A) the ethylene resin, (B) the propylene-based soft polyolefin, (C) the acid-modified polyolefin, and (D) the block copolymer of propylene and polyhydric alcohol is 100% by mass.

[0072] The blending amount of the (A) ethylene-based resin can be appropriately selected from the viewpoint of the expandability of the resin film and from the viewpoint of suppressing plate-out of the (D) block copolymer of propylene and a polyhydric alcohol. From the viewpoint of the expandability of the resin film, the blending amount of the (A) ethylene-based resin may be usually 18% by mass or more, preferably 24% by mass or more, more preferably 30% by mass or more, and even more preferably 36% by mass or more. On the other hand, from the viewpoint of suppressing plate-out of the (D) block copolymer of propylene and a polyhydric alcohol, the blending amount of the (A) ethylene-based resin may be usually 97% by mass or less, preferably 88% by mass or less, more preferably 81% by mass or less, and even more preferably 72% by mass or less. From the viewpoint of the expandability of the resin film and the suppression of plate-out of the block copolymer of propylene and a polyhydric alcohol (D), the blending amount of the (A) ethylene-based resin may usually be 18% by mass or more and 97% by mass or less, and preferably 18% by mass or more and 88% by mass or less, 18% by mass or more and 81% by mass or less, 18% by mass or more and 72% by mass or less, 24% by mass or more and 97% by mass or less, 24% by mass or more and 88% by mass or less, 24% by mass or more and 81% by mass or less, 24% by mass or more and 72% by mass or less, 30% by mass or more and 97% by mass or less, 30% by mass or more and 88% by mass or less, 30% by mass or more and 81% by mass or less, 30% by mass or more and 72% by mass or less, 36% by mass or more and 97% by mass or less, 36% by mass or more and 88% by mass or less, 36% by mass or more and 81% by mass or less, or 36% by mass or more and 72% by mass or less.

[0073] The blending amount of (B) propylene-based soft polyolefin can be appropriately selected from the viewpoint of suppressing plate-out of (D) propylene and polyhydric alcohol block copolymer and enhancing the antistatic effect of component (D), and from the viewpoint of the expandability of the resin film. The blending amount of (B) propylene-based soft polyolefin may be usually 1% by mass or more, preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 12% by mass or more, from the viewpoint of suppressing plate-out of (D) propylene and polyhydric alcohol block copolymer and enhancing the antistatic effect of component (D). On the other hand, the blending amount of (B) propylene-based soft polyolefin may be usually 40% by mass or less, preferably 38% by mass or less, more preferably 36% by mass or less, and even more preferably 34% by mass or less, from the viewpoint of the expandability of the resin film. The blending amount of the propylene-based soft polyolefin (B) may be, from the viewpoint of suppressing plate-out of the block copolymer of propylene and polyhydric alcohol (D) and thereby assisting the antistatic property-imparting effect of the component (D), and from the viewpoint of the expandability of the resin film, usually from 1 to 40% by mass, preferably from 1 to 38% by mass, 1 to 36% by mass, 1 to 34% by mass, 5 to 40% by mass, 5 to 38% by mass, 5 to 36% by mass, 5 to 34% by mass, 8 to 40% by mass, 8 to 38% by mass, 8 to 36% by mass, 8 to 34% by mass, 12 to 40% by mass, 12 to 38% by mass, 12 to 36% by mass, or 12 to 34% by mass.

[0074] The amount of the acid-modified polyolefin (C) can be appropriately selected from the viewpoint of suppressing plate-out of the block copolymer of propylene and a polyhydric alcohol (D) and from the viewpoint of film formability. The amount of the acid-modified polyolefin (C) may be usually 1% by mass or more, preferably 2% by mass or more, more preferably 3% by mass or more, and even more preferably 4% by mass or more. On the other hand, from the viewpoint of film formability, the amount of the acid-modified polyolefin (C) may be usually 16% by mass or less, preferably 14% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less. From the viewpoint of suppressing plate-out of the block copolymer of propylene and a polyhydric alcohol (D) and from the viewpoint of film formability, the blending amount of the acid-modified polyolefin (C) may be typically from 1 to 16% by mass, preferably from 1 to 14% by mass, from 1 to 12% by mass, from 1 to 10% by mass, from 2 to 16% by mass, from 2 to 14% by mass, from 2 to 12% by mass, from 2 to 10% by mass, from 3 to 16% by mass, from 3 to 14% by mass, from 3 to 12% by mass, from 3 to 10% by mass, from 4 to 16% by mass, from 4 to 14% by mass, from 4 to 12% by mass, or from 4 to 10% by mass.

[0075] The blending amount of the block copolymer of propylene and a polyhydric alcohol (D) can be appropriately selected from the viewpoint of suppressing plate-out, taking into consideration the desired level of antistatic properties. From the viewpoint of suppressing plate-out, the blending amount of the block copolymer of propylene and a polyhydric alcohol (D) may be usually 26% by mass or less, preferably 24% by mass or less, more preferably 22% by mass or less, and even more preferably 20% by mass or less. On the other hand, from the viewpoint of antistatic properties, the blending amount of the block copolymer of propylene and a polyhydric alcohol (D) may be usually 1% by mass or more, preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 12% by mass or more. The blending amount of the block copolymer of propylene and a polyhydric alcohol (D) may be, taking into consideration the desired level of antistatic properties and from the viewpoint of suppressing plate-out, typically 1% by mass or more and 26% by mass or less, preferably 1% by mass or more and 24% by mass or less, 1% by mass or more and 22% by mass or less, 1% by mass or more and 20% by mass or less, 5% by mass or more and 26% by mass or less, 5% by mass or more and 24% by mass or less, 5% by mass or more and 22% by mass or less, 5% by mass or more and 20% by mass or less, 8% by mass or more and 26% by mass or less, 8% by mass or more and 24% by mass or less, 8% by mass or more and 22% by mass or less, 8% by mass or more and 20% by mass or less, 12% by mass or more and 26% by mass or less, 12% by mass or more and 24% by mass or less, 12% by mass or more and 22% by mass or less, or 12% by mass or more and 20% by mass or less.

[0076] The mass ratio of the blending amount of the propylene-based flexible polyolefin (B) to the blending amount of the block copolymer of propylene and polyhydric alcohol (D) (blended amount of component (B) / blended amount of component (D)) may be preferably 0.4 or more, more preferably 0.6 or more, and even more preferably 0.8 or more, from the viewpoint of suppressing plate-out. On the other hand, this mass ratio may be preferably 10 or less, more preferably 6 or less, and even more preferably 3 or less, from the viewpoint of forming a eutectic between the propylene-based flexible polyolefin (B) and the propylene polymer segment (D) and suppressing plate-out, even when there is a large difference between their melting points. From the viewpoint of suppressing plate-out, the mass ratio of the blending amount of the propylene-based soft polyolefin (B) to the blending amount of the block copolymer of propylene and polyhydric alcohol (D) may be preferably 0.4 to 10, 0.4 to 6, 0.4 to 3, 0.6 to 10, 0.6 to 6, 0.6 to 3, 0.8 to 10, 0.8 to 6, or 0.8 to 3.

[0077] The resin composition of the present invention may further contain optional components other than components (A) to (D) as desired, to the extent that the object of the present invention is not adversely affected. Examples of such optional components include thermoplastic resins other than components (A) to (C), antistatic agents other than component (D), and additives commonly used in polyolefin-containing compositions.

[0078] Examples of the thermoplastic resin other than the components (A) to (C) as an optional component include polyethylenes such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), very low-density polyethylene (VLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), and ethylene-α-olefin copolymers (including random copolymers and block copolymers); polypropylenes such as propylene homopolymers and propylene-α-olefin copolymers (including random copolymers and block copolymers) having a melting point exceeding 120°C; ethylene-vinyl acetate copolymers, polybutene, and polypentene.

[0079] Examples of the optional antistatic agent other than component (D) include glycerin fatty acid esters.

[0080] Examples of the additives typically used in polyolefin-containing compositions as optional components include antioxidants, neutralizing agents, slip agents, antiblocking agents, antifogging agents, weather resistance stabilizers, light resistance stabilizers, nucleating agents, inorganic colorants, organic colorants, and masterbatches for dry blending of these additives.

[0081] Examples of the antioxidant include hindered phenol-based antioxidants, phosphite-based antioxidants, and thioether-based antioxidants.

[0082] Examples of the neutralizing agent include fatty acid metal salts such as calcium stearate, zinc stearate, and magnesium stearate, hydrotalcites, and composite metal hydroxides such as lithium aluminum composite hydroxide.

[0083] Examples of the slip agent include fatty acid amides such as erucic acid amide, oleic acid amide, stearic acid amide, behenic acid amide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, stearyl erucamide, and oleyl palmitamide.

[0084] Examples of the anti-blocking agent include inorganic fine particles such as silica, and organic fine particles such as cross-linked acrylic resins.

[0085] These optional components may be used alone or in combination of two or more.

[0086] The amount of the optional components is not particularly limited as long as it does not contradict the object of the present invention. In one embodiment, the amount of the optional components may be 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less, 7 parts by mass or less, 5 parts by mass or less, 4 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, 1 part by mass or less, or 0.5 parts by mass or less, or may be about 0 parts by mass or more and 0.5 parts by mass or about 0.01 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the total amount of components (A) to (D).

[0087] In one embodiment, the resin composition of the present invention may not contain any one or more of the optional components described above.

[0088] As used herein, "not containing a certain component" means that the component is not intentionally blended. In the technical field of resin compositions, when a certain component is intentionally blended, it is typically blended in an amount of 0.01 part by mass or more. Therefore, "not containing a certain component" can also be rephrased as meaning that the content of the component is typically less than 0.01 part by mass, preferably 0.001 part by mass or less, and more preferably 0.0001 part by mass or less (0 part by mass or more) per 100 parts by mass of the total blended amounts of components (A) to (D).

[0089] The resin composition of the present invention can be obtained by using any melt kneader, charging components (A) to (D) and any optional components used as desired into the melt kneader simultaneously or in any order, and melt kneading, preferably at a resin temperature of 200 to 260°C.

[0090] Examples of the melt kneader include batch kneaders such as pressure kneaders and mixers, extrusion kneaders such as single-screw extruders, co-rotating twin-screw extruders, and counter-rotating twin-screw extruders, and calendar roll kneaders. Two or more of these may be used in any combination.

[0091] The resulting resin composition can be pelletized by any method and then molded into any article by any method, such as hot cutting, strand cutting, or underwater cutting.

[0092] Alternatively, the resulting resin composition may be directly subjected to film formation or molding.

[0093] 2. Resin Film The resin film of the present invention is a resin film including at least one layer formed from the resin composition of the present invention. The resin film of the present invention typically includes at least one layer formed from the resin composition of the present invention, and this layer can form at least one surface of the resin film. The resin film of the present invention may be a monolayer film or a multilayer film. The multilayer film may consist of only a plurality of resin films of the present invention, or may include one or more resin films of the present invention and one or more other resin films. In the latter case, the other resin constituting the other resin film is not particularly limited and may be any known resin. The other resin film also includes a resin film forming a pressure-sensitive adhesive layer. In one embodiment, the resin film of the present invention may be a monolayer film. In another embodiment, the resin film of the present invention may be a multilayer film in which both outer layers are formed using virgin materials from the resin composition of the present invention and the intermediate layer is formed using a mixture of virgin materials from the resin composition of the present invention and recycled materials such as materials derived from film selvages (removed portions on both ends of the film that exceed the specified width range during film production).

[0094] The thickness of the resin film of the present invention is not particularly limited and can be appropriately selected taking into consideration the specific type of film to be used in semiconductor manufacturing processes and its intended use. The thickness of the resin film of the present invention may be typically 30 to 500 μm, preferably 50 to 300 μm, more preferably 60 to 200 μm, even more preferably 70 to 150 μm, and most preferably 80 to 120 μm. Here, the thickness refers to the overall thickness of the resin film including at least one layer formed from the resin composition of the present invention (or the total thickness of the layers when the film is composed of multiple layers).

[0095] The surface resistivity of the resin film of the present invention can be appropriately selected taking into consideration the specific type of film to be used in the semiconductor manufacturing process and its usage. From the viewpoint of antistatic properties, the surface resistivity of the resin film of the present invention is usually 1×10 １１ Ω / □ or less, preferably 1×10 １０ On the other hand, the surface resistivity of the resin film of the present invention is usually 1×10 ７ Ω / □ or more, preferably 1×10 ８ In one embodiment, the surface resistivity of the resin film of the present invention is generally 1×10 Ω / □ or more from the viewpoint of antistatic properties and suppressing problems caused by electrical conduction. ７ Ω / □ or more 1×10 １１ Ω / □ or less, preferably 1×10 ７ Ω / □ or more 1×10 １０ Ω / □ or less, 1×10 ８ Ω / □ or more 1×10 １１ Ω / □ or less, or 1 x 10 ８ Ω / □ or more 1×10 １０ The surface resistivity may be Ω / □ or less. Here, the surface resistivity is measured according to the following test (iii) Surface Resistivity.

[0096] The machine direction strain tensile stresses of the resin film of the present invention may preferably be such that the 10% strain tensile stress is greater than the 5% strain tensile stress, the 25% strain tensile stress is greater than the 10% strain tensile stress, the 50% strain tensile stress is greater than the 25% strain tensile stress, and the 100% strain tensile stress is greater than the 50% strain tensile stress. When the strain tensile stresses of the resin film of the present invention have the above-mentioned relationship, necking is strongly suppressed, and the film can be suitably used as a film substrate with excellent expandability for semiconductor manufacturing processes. Here, "necking" refers to the occurrence of partial elongation due to poor force propagation when the film is stretched. Here, each strain tensile stress is measured according to the following test (iv) tensile test.

[0097] 3. Film Forming Method The method for forming the resin film of the present invention is not particularly limited, and known film forming methods can be used. Examples of the film forming method include a film forming method using a calender roll rolling film forming apparatus equipped with a calender roll rolling processing machine and a take-up device; a film forming method using a T-die film forming apparatus equipped with an extruder, a T-die, and a take-up device; and a film forming method using an inflation film forming apparatus equipped with an extruder, a circular die, an inflation device, and a take-up device with a nip mechanism.

[0098] A preferred method for producing a multilayer resin film of the present invention, in which both outer layers are formed using virgin materials of the resin composition of the present invention and the middle layer is formed using a mixture of virgin materials of the resin composition of the present invention and recycled materials such as materials derived from the selvage of a film, will be described.

[0099] A preferred method for producing the multilayer film includes, for example, using a film-producing apparatus equipped with a plurality of extruders, a coextrusion T-die, and a take-up device having a first chill roll and a mechanism for pressing a molten film against the first chill roll, and performing the following steps: (1) continuously co-extruding a molten multilayer film from the coextrusion T-die; (2) using the pressing mechanism to press the molten multilayer film extruded in step (1) against the rotating first chill roll so that it is held thereon; and (3) sending the multilayer film held against the first chill roll in step (2) from the first chill roll to the next rotating roll.

[0100] The extruder is not particularly limited and may be appropriately selected from known extruders, such as a single-screw extruder, a co-rotating twin-screw extruder, and a counter-rotating twin-screw extruder.

[0101] To prevent deterioration of the raw material resin, it is preferable to purge the inside of the extruder with nitrogen. It is also preferable to dry the raw material resin before using it for film formation. It is also preferable to transport the dried resin directly from the dryer to the extruder and charge it.

[0102] The coextrusion T-die is not particularly limited, and any known coextrusion T-die can be appropriately selected and used. Examples of the coextrusion T-die include multi-manifold type, stack plate type, and feed block type.

[0103] The first chill roll is not particularly limited, and any known rotating roll having a cooling mechanism can be appropriately selected and used. Examples of the first chill roll include a mirror-finished or matte metal rotating roll having a mechanism for circulating a cooling medium such as water or oil inside the roll.

[0104] The pressing mechanism is not particularly limited, and any known pressing mechanism can be appropriately selected and used. Examples of the pressing mechanism include an air knife, an air chamber, a vacuum chamber, a nip roll, and combinations thereof.

[0105] The set temperature of the outlet (lip) of the co-extrusion T-die in step (1) can be appropriately selected from the viewpoints of stably performing the step of continuously co-extruding the molten multilayer film, suppressing deterioration of the raw material resins, and suppressing plate-out. From the viewpoint of stably performing the step of continuously co-extruding the molten multilayer film, the set temperature may be typically 200°C or higher, preferably 220°C or higher, and more preferably 230°C or higher. On the other hand, from the viewpoints of suppressing deterioration of the raw material resins and suppressing plate-out, the set temperature may be typically 300°C or lower, preferably 280°C or lower, and more preferably 260°C or lower. In one embodiment, from these viewpoints, the set temperature may typically be 200°C or higher and 300°C or lower, preferably 200°C or higher and 280°C or lower, 200°C or higher and 260°C or lower, 220°C or higher and 300°C or lower, 220°C or higher and 280°C or lower, 220°C or higher and 260°C or lower, 230°C or higher and 300°C or lower, 230°C or higher and 280°C or lower, or 230°C or higher and 260°C or lower.

[0106] The surface temperature of the first chill roll can be appropriately selected from the viewpoints of completely cooling and solidifying the multilayer film when it is fed from the first chill roll to the next rotating roll in step (3) and preventing condensation from forming on the surface of the first chill roll. The surface temperature of the first chill roll may be typically 80°C or lower, preferably 60°C or lower, and more preferably 50°C or lower, from the viewpoint of completely cooling and solidifying the multilayer film when it is fed from the first chill roll to the next rotating roll in step (3). On the other hand, the surface temperature of the first chill roll may be typically 15°C or higher, preferably 20°C or higher, more preferably 25°C or higher, and even more preferably 30°C or higher, from the viewpoint of preventing condensation from forming on the surface of the first chill roll, although this depends on the temperature and humidity of the film-forming environment. In one embodiment, from these viewpoints, the surface temperature of the first chill roll may be typically 15°C or higher and 80°C or lower, preferably 15°C or higher and 60°C or lower, 15°C or higher and 50°C or lower, 20°C or higher and 80°C or lower, 20°C or higher and 60°C or lower, 20°C or higher and 50°C or lower, 25°C or higher and 80°C or lower, 25°C or higher and 60°C or lower, 25°C or higher and 50°C or lower, 30°C or higher and 80°C or lower, 30°C or higher and 60°C or lower, or 30°C or higher and 50°C or lower.

[0107] When a nip roll is used as the pressing mechanism, it is preferable to use one having a mechanism for controlling the surface temperature of the nip roll. In this case, the surface temperature of the nip roll can be appropriately selected taking into consideration the surface material of the nip roll from the viewpoint of suppressing or preventing the problem of the molten multilayer film adhering to the nip roll and from the viewpoint of preventing condensation on the surface of the nip roll. From the viewpoint of suppressing or preventing the problem of the molten multilayer film adhering to the nip roll, the surface temperature of the nip roll may be usually 80°C or less, preferably 70°C or less, and more preferably 60°C or less, although it depends on the surface material of the nip roll. On the other hand, from the viewpoint of preventing condensation on the surface of the nip roll, the surface temperature of the nip roll may be usually 15°C or more, preferably 20°C or more, more preferably 25°C or more, and even more preferably 30°C or more, although it depends on the temperature and humidity of the film production environment. In one embodiment, from these viewpoints, the surface temperature of the nip roll may be typically 15°C or higher and 80°C or lower, preferably 15°C or higher and 70°C or lower, 15°C or higher and 60°C or lower, 20°C or higher and 80°C or lower, 20°C or higher and 70°C or lower, 20°C or higher and 60°C or lower, 25°C or higher and 80°C or lower, 25°C or higher and 70°C or lower, 25°C or higher and 60°C or lower, 30°C or higher and 80°C or lower, 30°C or higher and 70°C or lower, or 30°C or higher and 60°C or lower.

[0108] In step (3), the multilayer film that has been pressed against and embraced by the first chill roll in step (2) is sent to the next rotating roll. By pressing the molten multilayer film against and embraced by the first chill roll, it is possible to ensure that the multilayer film is completely cooled and solidified when sent to the next rotating roll.

[0109] 4. Semiconductor manufacturing process film The semiconductor manufacturing process film of the present invention includes the resin film of the present invention. The semiconductor manufacturing process film of the present invention can usually be produced by using the resin film of the present invention as a film substrate, forming a pressure-sensitive adhesive layer on one side of the film substrate directly or via an anchor coat, and then slitting the film to a desired width.

[0110] The adhesive for forming the adhesive layer is not particularly limited, but examples thereof include acrylic adhesives such as poly(meth)acrylic acid alkyl esters and copolymers of (meth)acrylic acid alkyl esters with other monomers copolymerizable with (meth)acrylic acid alkyl esters, such as (meth)acrylic acid; rubber adhesives such as natural rubber and butyl-isoprene rubber; polyurethane adhesives; polyester adhesives; polystyrene adhesives; and silicone adhesives.

[0111] In one preferred embodiment, the adhesive may be cured by heat treatment or active energy ray irradiation to reduce its adhesive strength. By reducing the adhesive strength, the semiconductor manufacturing process film can be easily peeled cleanly from a workpiece (e.g., an adherend such as a semiconductor wafer) without leaving any adhesive residue. Furthermore, the amount of static electricity generated when peeling the semiconductor manufacturing process film from the workpiece can be reduced. Examples of adhesives that can reduce their adhesive strength include adhesives having two or more reactive functional groups per molecule (e.g., amino groups, vinyl groups, epoxy groups, methacryloxy groups, acryloxy groups, isocyanate groups, etc.), and adhesive compositions containing the adhesive and at least one of an isocyanate-based curing agent, a photopolymerization initiator, and an organic peroxide.

[0112] In one preferred embodiment, the pressure-sensitive adhesive may have excellent transparency, from the viewpoint of ensuring sufficient transparency required for semiconductor manufacturing process films, for example, visibility during laser marking. Here, "a pressure-sensitive adhesive with excellent transparency" refers to a pressure-sensitive adhesive having a visible light transmittance of typically 50% or more, preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more. Visible light transmittance is measured using a Shimadzu Corporation "Solid Spec-3700" spectrophotometer and a quartz cell with an optical path length of 10 mm. The integrated area of ​​the transmission spectrum of the pressure-sensitive adhesive at wavelengths of 380 to 780 nanometers is calculated as the ratio of the integrated area of ​​the transmission spectrum to the integrated area of ​​the transmission spectrum assuming a transmittance of 100% over the entire wavelength range of 380 to 780 nanometers.

[0113] In one preferred embodiment, the pressure-sensitive adhesive may be an antistatic pressure-sensitive adhesive. From the viewpoint of antistatic properties, the surface resistivity of the pressure-sensitive adhesive layer formed using the antistatic pressure-sensitive adhesive is usually 1×10 １１ Ω / □ or less, preferably 1×10 １０ On the other hand, the surface resistivity of the pressure-sensitive adhesive layer is usually 1×10 ７ Ω / □ or more, preferably 1×10 ８ From these viewpoints, the surface resistivity of the pressure-sensitive adhesive layer is usually 1×10 ７ Ω / □ or more 1×10 １１ Ω / □ or less, preferably 1×10 ７ Ω / □ or more 1×10 １０ Ω / □ or less, 1×10 ８ Ω / □ or more 1×10 １１ Ω / □ or less, or 1 x 10 ８ Ω / □ or more 1×10 １０ The surface tension may be Ω / □ or less. Examples of the pressure-sensitive adhesive having antistatic properties include pressure-sensitive adhesives disclosed in JP 2007-191532 A, JP 2008-007702 A, JP 2009-242745 A, and WO 2015 / 030186 A.

[0114] As the pressure-sensitive adhesive, one of these or a mixture of two or more thereof can be used.

[0115] The method for forming the pressure-sensitive adhesive layer using the pressure-sensitive adhesive is not particularly limited, and any known web coating method can be appropriately selected and used. As the web coating method, from the viewpoint of applying the pressure-sensitive adhesive coating material with good productivity by a roll-to-roll method, methods such as rod coating, roll coating, gravure coating, reverse coating, kiss reverse coating, and die coating are preferred.

[0116] The thickness of the pressure-sensitive adhesive layer is not particularly limited and can be appropriately selected taking into consideration the specific type of the target semiconductor manufacturing process film, its usage mode, and the properties of the pressure-sensitive adhesive used. The thickness of the pressure-sensitive adhesive layer may be generally about 1 to 30 μm, preferably about 5 to 25 μm, and more preferably about 10 to 20 μm.

[0117] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0118] Measurement and evaluation methods of physical properties (i) Plate-out index (ΔG) (1) A film-making apparatus (having an extruder 1 with a diameter of 40 mm, a T-die 2 with a resin outlet width of 600 mm, and a take-up device having a mechanism for nipping with a smooth roll (mirror-finish metal roll) 4 with a diameter of 250 mm and a grain roll (matt-finish rubber roll) 5 with a diameter of 150 mm) shown in the conceptual diagram of FIG. 2 was used. (2) Before film formation, the 8-degree specular gloss value (G ０) was applied to measure the specular gloss value of the curved surface, and the angles of incidence and reflection of light were set to 8 degrees. Measurements were performed using a spectrophotometer "CM-600d" (trade name) manufactured by Konica Minolta, Inc., equipped with a target mask "CM-A180" (trade name) attached to the spectrophotometer, in accordance with JIS Z8741-1997. A jig was used to fit the smooth roll and the color difference meter, and to ensure that the angles of incidence and reflection of light were 8 degrees. (3) Next, 20 kg of the resin composition was continuously extruded from a T-die 2 as a molten film 3. The extruded molten film 3 was fed and introduced between a rotating smooth roll 4 and a rotating textured roll 5, where it was pressed between the smooth roll 4 and the textured roll 5. The pressed molten film 3 was then wrapped around the smooth roll 4 and sent to the next rotating roll 6, producing a film 7 having a thickness of 100 μm. At this time, the resin temperature at the outlet of the T-die was 240°C, the surface temperature of the smooth roll 4 was 25°C, the temperature of the cooling water flowing through the grain roll 5 was 25°C, and the take-up speed was 6 m / min. (4) After film formation (after all 20 kg of the resin composition was extruded from the T-die), the 8° specular gloss value (G １ ) to the 8-degree specular gloss value (G ０ The plate-out index (ΔG: unit %) was calculated from the 8-degree specular gloss values ​​of the smooth roll surface before and after film formation using the following formula (1): ΔG = (G ０ -G １ ) / G ０ × 100 ... (1)

[0119] (ii) Plate-out state (visual observation) The state of the smooth roll surface before and after film formation in the above test (i) Plate-out index (ΔG) was visually observed, and the plate-out state was judged according to the following criteria: A: Plate-out was sufficiently suppressed. B: Plate-out was suppressed. C: Plate-out was observed. D: Significant plate-out was observed.

[0120] When the plate-out state (visual observation) of the above test (ii) was ranked A, ΔG was generally 10% or less. When it was ranked B, ΔG was generally more than 10% to 20%. When it was ranked C, ΔG was generally more than 20% to 30%. When it was ranked D, ΔG was generally more than 30%.

[0121] (iii) Surface Resistivity The test specimen was pretreated by leaving it in an environment of 25°C and 50% relative humidity for 24 hours, and the resistivity was measured in an environment of 25°C and 50% relative humidity. In accordance with JIS K6911:1995, 5.13 Resistivity and 5.13.2 Laminated Plates, except that the test specimen was pretreated by leaving it in an environment of 25°C and 50% relative humidity, the surface resistivity (unit: Ω / □) was measured using a resistivity meter "Hiresta-UP MCP-HT450" (trade name) and a double ring probe "MCP-JB03" (trade name) manufactured by Nitto Seiko Analytech Co., Ltd. The probe was crimped to the test specimen with a load of 30N, and a voltage of 100V was applied. 30 seconds later, the surface resistivity (unit: Ω / □) was measured. The test specimen was a square film piece with a side length of 10 cm taken from the resin film formed in the above test (i) Plate-out Index (ΔG). For example, the notation "1E+10" in the table indicates that the surface resistivity is 1 x 10 １０ Ω / □. Also, >1E+11 means that the surface resistivity is 1×10 １１ This means that the resistance exceeded Ω / □.

[0122] (iv) Tensile Test (iv-1) Creation of Stress-Strain Curve According to JIS K7127:1999, a tensile tester "Autograph AGS-1kNG" (trade name) manufactured by Shimadzu Corporation was used to punch out a sample from the resin film formed in the above test (i) Plate-out Index (ΔG) into the shape of a test piece Type 2 of the above standard (Figure 1 of the JIS standard) with the machine direction as the tensile direction, and a tensile test was performed at a tensile speed of 200 mm / min to obtain a stress-strain curve. At this time, the sample was conditioned for 16 hours or more in an environment of a temperature of 23±2°C and a humidity of 50±10%, and then a tensile test was performed in the same temperature and humidity environment.

[0123] (iv-2) Calculation of strain tensile stress, tensile stress at break, and tensile strain at break: From the stress-strain curve obtained above, the 5% strain tensile stress (unit: MPa), 10% strain tensile stress (unit: MPa), 25% strain tensile stress (unit: MPa), 50% strain tensile stress (unit: MPa), 100% strain tensile stress (unit: MPa), tensile stress at break (unit: MPa), and tensile strain at break (unit: %) were calculated according to JIS K7161-1:2014.

[0124] Raw materials used: (A) Ethylene-based resin; (A-1) Mitsui-Dow Polychemicals' zinc ion ionomer "Himilan 1855" (trade name), melt mass flow rate (190°C, 21.18N) 1.0 g / 10 min, crystallization temperature 55°C, melting point 83°C, melting enthalpy 57 J / g. According to JP 2013-098443 A, this is an ionomer obtained by neutralizing an ethylene-methacrylic acid-ethyl methacrylate copolymer with zinc ions. The content of structural units derived from ethylene is 80% by mass, the content of structural units derived from methacrylic acid is 10% by mass, and the content of structural units derived from ethyl methacrylate is 10% by mass. (A-2) Dow Mitsui Polychemical Co., Ltd.'s zinc ion ionomer "Himilan 1652" (trade name), melt mass flow rate (190°C, 21.18N) 5.5 g / 10 min, crystallization temperature 81°C, melting point 96°C, melting enthalpy 94 J / g. According to JP 2008-052011 A, this is an ionomer obtained by neutralizing an ethylene-methacrylic acid copolymer with zinc ions. It contains 16% by mass of structural units derived from methacrylic acid and 84% by mass of structural units derived from ethylene. (A-3) Dow Mitsui Polychemical Co., Ltd.'s sodium ion ionomer "Himilan 1707" (trade name), melt mass flow rate (190°C, 21.18N) 0.9 g / 10 min, crystallization temperature 48°C, melting point 86°C, melting enthalpy 30 J / g. According to JP 2022-172416 A, an ionomer is an ethylene-methacrylic acid copolymer partially neutralized with sodium ions. The content of structural units derived from ethylene is 94.5 mol%, and structural units derived from methacrylic acid is 5.5 mol% (3.1 mol% unneutralized units, 2.4 mol% neutralized units). (A-4) Dow Mitsui Polychemicals' ethylene-methacrylic acid copolymer "Nucrel N0903HC" (trade name), melt mass flow rate (190°C, 21.18N) 2.5 g / 10 min, content of structural units derived from methacrylic acid is 9% by mass, content of structural units derived from ethylene is 91% by mass, crystallization temperature is 84°C, melting point is 98°C, and melting enthalpy is 98 J / g.

[0125] (B) Propylene-based soft polyolefin (B-1) Mitsui Chemicals, Inc.'s propylene-based soft polyolefin "Tafmer XM7090" (trade name), melt mass flow rate (190°C, 21.18N) 3.0 g / 10 min, melt mass flow rate (230°C, 21.18N) 7.0 g / 10 min, crystallization temperature 56°C, melting point 96°C, melting enthalpy 48 J / g. According to JP 2019-199530 A, it is a propylene-1-butene copolymer. The content of structural units derived from 1-butene is 4.9% by mass (3.7 mol%), and the content of structural units derived from propylene is 95.1% by mass (96.3 mol%). (B-2) Mitsui Chemicals, Inc.'s propylene-based soft polyolefin "Tafmer XM7070S" (trade name), melt mass flow rate (190°C, 21.18N) 3.0 g / 10 min, melt mass flow rate (230°C, 21.18N) 7.0 g / 10 min, crystallization temperature 29°C, melting point 75°C, melting enthalpy 31 J / g. According to JP 2016-035054 A, it is a propylene-1-butene copolymer. The content of structural units derived from propylene is 74 mol% (68% by mass), and the content of structural units derived from 1-butene is 26 mol% (32% by mass).

[0126] (C) Acid-modified polyolefin (C-1) Mitsui Chemicals, Inc.'s acid-modified polyolefin "TAFMER MD715" (trade name), melt mass flow rate (190°C, 21.18N) 1.5g / 10min, melt mass flow rate (230°C, 21.18N) 3.0g / 10min, crystallization temperature 33°C, melting point 50°C, melting enthalpy 32J / g. According to JP 2016-030810 A, a maleic anhydride-modified ethylene-1-butene copolymer. (C-2) Mitsui Chemicals, Inc.'s acid-modified polyolefin "Tafmer MA8510" (trade name), melt mass flow rate (190°C, 21.18N) 2.4 g / 10 min, melt mass flow rate (230°C, 21.18N) 5.0 g / 10 min, crystallization temperature 54°C, melting point 70°C, melting enthalpy 36 J / g. JP 2018-076516 A describes a maleic anhydride graft-modified product obtained by graft copolymerizing maleic anhydride onto an ethylene-α-olefin copolymer.

[0127] (D) Block Copolymers of Propylene and Polyhydric Alcohols (D-1) "PELECTRON UC" (trade name), a block copolymer having a propylene polymer segment and a polyethylene glycol segment, manufactured by Sanyo Chemical Industries, Ltd., with a melt mass flow rate (190°C, 21.18N) of 12 g / 10 min. This block copolymer has peaks at peak top temperatures of 86°C and 79°C attributable to the propylene polymer segment and a peak at a peak top temperature of 5°C attributable to the polyethylene glycol segment in its DSC crystallization curve, and peaks at peak top temperatures of 156°C and 131°C attributable to the propylene polymer segment and a peak at a peak top temperature of 31°C attributable to the polyethylene glycol segment in its DSC second melting curve. (D-2) "PELECTRON PVH" (trade name), a block copolymer having a propylene polymer segment and a polyethylene glycol segment, manufactured by Sanyo Chemical Industries, Ltd., with a melt mass flow rate (190°C, 21.18N) of 8 g / 10 min. This block copolymer has a DSC crystallization curve with a peak at a peak top temperature of 81°C and a shoulder peak near 90°C attributable to the propylene polymer segment, and a peak at a peak top temperature of 8°C attributable to the polyethylene glycol segment. The DSC second melting curve has shoulder peaks at peak top temperatures of 134°C and near 150°C attributable to the propylene polymer segment, and a peak at a peak top temperature of 34°C attributable to the polyethylene glycol segment. (D-3) Sanyo Chemical Industries, Ltd.'s block copolymer "Pelectron PVL" (trade name) having a propylene polymer segment and a polyethylene glycol segment, melt mass flow rate (190°C, 21.18N) 15 g / 10 min. This block copolymer has a DSC crystallization curve with a peak at a peak top temperature of 83°C attributable to the propylene polymer segment, and a peak at a peak top temperature of 8°C attributable to the polyethylene glycol segment. The DSC second melting curve has a peak at a peak top temperature of 132°C attributable to the propylene polymer segment, and a peak at a peak top temperature of 33°C attributable to the polyethylene glycol segment.

[0128] Example 1 A blend consisting of 56% by mass of the above (A-1), 17% by mass of the above (B-1), 10% by mass of the above (C-1), and 17% by mass of the above (D-1) was melt-kneaded using a twin-screw extrusion melt kneader at a die outlet resin temperature of 200°C to obtain a resin composition. The above tests (i) to (iii) were carried out. The results are shown in Table 1.

[0129] Examples 2 to 18 Resin compositions were obtained in the same manner as in Example 1, except that the formulation was changed as shown in Table 1 or Table 2. The above tests (i) to (iii) were carried out. The results are shown in Table 1 or 2. The test piece obtained from the resin composition of Example 18 had a surface resistivity of 1×10 １４ Since the antistatic property was very low at Ω / □, the above-mentioned plate-out tests (i) and (ii) were omitted.

[0130]

[0131]

[0132] It was found that the resin composition of the present invention has antistatic properties and plate-out is suppressed. Furthermore, it was found that the resin composition according to a preferred embodiment of the present invention has sufficient antistatic properties and plate-out is sufficiently suppressed.

[0133] Furthermore, the resin films formed using the resin compositions of Examples 1 to 3 and Example 6 in the above test (i) plate-out index (ΔG) were subjected to the above test (iv) tensile test.

[0134] The resin film formed using the resin composition of Example 1 had a 5% strain tensile stress of 4.8 MPa, a 10% strain tensile stress of 6.7 MPa, a 25% strain tensile stress of 8.4 MPa, a 50% strain tensile stress of 9.0 MPa, a 100% strain tensile stress of 9.8 MPa, a tensile break stress of 30.9 MPa, and a tensile break strain of 500%.

[0135] The resin film formed using the resin composition of Example 2 had a 5% strain tensile stress of 5.2 MPa, a 10% strain tensile stress of 7.3 MPa, a 25% strain tensile stress of 9.1 MPa, a 50% strain tensile stress of 9.7 MPa, a 100% strain tensile stress of 10.5 MPa, a tensile breaking stress of 33.4 MPa, and a tensile breaking strain of 500%.

[0136] The resin film formed using the resin composition of Example 3 had a 5% strain tensile stress of 5.1 MPa, a 10% strain tensile stress of 7.2 MPa, a 25% strain tensile stress of 9.0 MPa, a 50% strain tensile stress of 9.5 MPa, a 100% strain tensile stress of 10.2 MPa, a tensile breaking stress of 34.5 MPa, and a tensile breaking strain of 540%.

[0137] The resin film formed using the resin composition of Example 6 had a 5% strain tensile stress of 6.7 MPa, a 10% strain tensile stress of 9.2 MPa, a 25% strain tensile stress of 11.5 MPa, a 50% strain tensile stress of 12.6 MPa, a 100% strain tensile stress of 13.6 MPa, a tensile break stress of 29.6 MPa, and a tensile break strain of 510%.

[0138] It was found that the resin film formed from the resin composition according to the preferred embodiment of the present invention has excellent expandability.

[0139] From these results, it was considered that a resin film containing a layer formed using the resin composition of the present invention can be suitably used as a film substrate for semiconductor manufacturing process films, such as dicing films, backgrinding films, and die attach films, and can be particularly suitably used as a film substrate for semiconductor manufacturing process films used in producing small, thin semiconductor chips.

[0140] 1: Extruder 2: T-die 3: Molten film 4: Smooth roll 5: Grain roll 6: Rotating roll 7: Film

Claims

1. A resin composition comprising: (A) 18 to 97% by mass of at least one ethylene-based resin selected from the group consisting of an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, an ionomer of an ethylene-unsaturated carboxylic acid copolymer, and an ionomer of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer; (B) 1 to 40% by mass of a propylene-based soft polyolefin; (C) 1 to 16% by mass of an acid-modified polyolefin; and (D) 1 to 26% by mass of a block copolymer of propylene and a polyhydric alcohol, wherein the sum of the blend amounts of the (A) ethylene-based resin, (B) the propylene-based soft polyolefin, (C) the acid-modified polyolefin, and (D) the block copolymer of propylene and a polyhydric alcohol is 100% by mass.

2. The resin composition according to claim 1, wherein the melting point of the propylene-based soft polyolefin (B) is 60 to 115°C.

3. The resin composition according to claim 2, wherein the absolute value of the difference between the crystallization temperature of the ethylene-based resin (A) and the crystallization temperature of the propylene-based soft polyolefin (B) is 20°C or less.

4. The resin composition according to claim 1, wherein (C) the acid-modified polyolefin comprises an acid-modified polyethylene.

5. The resin composition according to claim 1, wherein the mass ratio of the blended amount of (B) propylene-based soft polyolefin to the blended amount of (D) propylene and polyhydric alcohol block copolymer is 0.4 to 10.

6. A resin film having at least one layer formed from the resin composition according to any one of claims 1 to 5.

7. The resin film according to claim 6, which is used as a film substrate for a film used in semiconductor manufacturing processes.

8. A film for use in semiconductor manufacturing processes, comprising the resin film according to claim 6.

Images