JP7796658B2 - Antistatic resin composition, resin film, and antistatic substrate film for dicing tape - Google Patents

Description

The present invention relates to an antistatic resin composition, a resin film comprising a layer formed from the antistatic resin composition, and a substrate film for antistatic dicing tape comprising the resin composition layer.

Semiconductor chips are produced by forming a large number of chips on a large-diameter silicon wafer and then dicing them into individual chips. The dicing process is often carried out after applying dicing tape to the front and/or back of the silicon wafer (on which multiple semiconductor chips are formed) for purposes such as protecting the surface of the semiconductor chips and fixing and picking up the individual chips after dicing.

In recent years, semiconductor chips have become smaller and thinner due to miniaturization of transistor structures and increased density of three-dimensional interconnect structures. As a result, static electricity generated during dicing has become more likely to cause problems, such as damage to the circuits of semiconductor chips. To address this issue, it has been proposed to impart antistatic properties to dicing tape and base films for dicing tape (see, for example, Patent Documents 1 to 3). However, these technologies require the incorporation of large amounts of antistatic agents to achieve sufficient antistatic properties. As a result, there are problems with the antistatic agent contaminating the metal rolls of the film-forming machine during film-forming of the base film. Furthermore, the antistatic agent contaminating the metal rolls of the film-forming machine is transferred to the base film, thereby reducing the properties of the adhesive layer formed on its surface.

Japanese Patent Application Laid-Open No. 2008-244377 JP 2011-210887 A Japanese Patent Application Laid-Open No. 2017-098369

The object of the present invention is to provide a resin composition that has sufficient antistatic properties and suppresses the inconvenience of the antistatic agent contaminating the metal rolls of the film-forming machine during film formation (hereinafter, this inconvenience may be abbreviated as "plate-out"), and a resin film that includes a layer formed from such a resin composition.
A further object of the present invention is to provide a resin film suitable as a base film for an adhesive tape (hereinafter referred to as "dicing tape") that is attached to the front and/or back surface of a silicon wafer or the like for the purpose of surface protection when dicing (cutting and separating) the silicon wafer or the like.

After extensive research, the inventors discovered that the above objective can be achieved by a resin composition having specific components and content ratios.

Aspects of the present invention are as follows.
[1].
(A) 20 to 99 parts by mass of an ethylene-based resin,
(B) 80 to 1 parts by mass of a propylene-based resin, and (C) 1 to 39 parts by mass of a block copolymer of propylene and a polyhydric alcohol;
Here, the sum of the blending amount of the component (A) ethylene-based resin and the blending amount of the component (B) propylene-based resin is 100 parts by mass;
The component (B) propylene-based resin does not include a block copolymer of propylene and a polyhydric alcohol.
Resin composition.
[2].
The resin composition according to item [1] above, wherein the mass ratio of the amount of the propylene-based resin (B) to the amount of the block copolymer of propylene and a polyhydric alcohol (C) is 0.4 or more.
[3].
the melt mass flow rate of the component (A) ethylene-based resin is lower than the melt mass flow rate of the component (C) block copolymer of propylene and polyhydric alcohol;
Here, the melt mass flow rate of the component (A) ethylene resin and the melt mass flow rate of the component (C) propylene and polyhydric alcohol block copolymer are measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 21.18 N.
The resin composition according to the above item [1] or [2].
[4].
the melting point of the propylene polymer segment of the component (C) propylene and polyhydric alcohol block copolymer is (Tm-30) to (Tm+30)°C;
Here, Tm is the melting point (unit: °C) of the propylene-based resin (component (B)).
The resin composition according to any one of the above items [1] to [3].
[5].
The resin composition according to any one of items [1] to [4] above, which is for use as a base film for a dicing tape.
[6].
A substrate film for a dicing tape, comprising at least one layer formed from the resin composition according to any one of items [1] to [5] above.
[7].
A dicing tape having a substrate film for a dicing tape, the substrate film comprising at least one layer formed from the resin composition according to any one of items [1] to [5] above.
[8].
A resin film comprising at least one layer formed from the resin composition according to any one of items [1] to [4] above.

The resin composition of the present invention has sufficient antistatic properties and suppresses plate-out. Preferred resin compositions of the present invention have sufficient antistatic properties and suppress plate-out, and resin films containing layers formed using the resin composition have excellent expandability. Therefore, resin films containing layers formed using the resin composition of the present invention can be suitably used as base films for dicing tapes, particularly those used in producing small, thin-film semiconductor chips.

FIG. 1 is a conceptual diagram of the film-forming apparatus used in the examples.

In this specification, the term "resin" is used to include resin mixtures containing two or more resins, as well as resin compositions containing components other than resin. In this specification, the term "film" is used 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. Furthermore, in this specification, laminating one layer with another layer in order includes both directly laminating the layers and laminating them with one or more additional layers, such as an anchor coat, interposed between them.

In this specification, the term "equivalent to or greater than" in relation to a numerical range means a certain number or more than a certain number. For example, 20% or more means 20% or more than 20%. The term "equal to or less than" in relation to a numerical range means a certain number or less than a certain number. For example, 20% or less means 20% or less than 20%. Furthermore, the symbol "to" in relation to a numerical range means a certain number, more than a certain number and less than another certain number, or another certain number. Here, another certain number is a number greater than the certain number. 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 combined in any way, 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.

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.

1. Resin Composition The resin composition of the present invention contains (A) an ethylene-based resin, (B) a propylene-based resin, and (C) a block copolymer of propylene and a polyhydric alcohol.
Here, the component (B) propylene-based resin does not include a block copolymer of propylene and a polyhydric alcohol. Therefore, compounds corresponding to the component (C) block copolymer of propylene and a polyhydric alcohol are excluded from the scope of the component (B) propylene-based resin. In other words, compounds corresponding to the block copolymer of propylene and a polyhydric alcohol are component (C) but not component (B).
Each component will be described below.

(A) Ethylene-Based Resin The component (A) ethylene-based resin is a resin primarily containing structural units derived from ethylene. Here, "primarily containing structural units derived from ethylene" means that the content of structural units derived from ethylene is usually 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and typically 75 to 100% by mass, based on the total mass of the ethylene-based resin. The component (A) ethylene-based resin functions to improve the expandability of the resin film.

Examples of the ethylene resin component (A) include low-density polyethylene, linear low-density polyethylene, very low-density polyethylene, medium-density polyethylene, and high-density polyethylene; ethylene-α-olefin copolymers such as ethylene-1-butene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer; ethylene-vinyl acetate copolymer; ethylene-unsaturated carboxylic acid ester copolymers such as ethylene-ethyl acrylate copolymer and ethylene-methyl methacrylate copolymer; ethylene-unsaturated carboxylic acid copolymers such as ethylene-acrylic acid copolymer and ethylene-methacrylic acid copolymer; ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymers such as ethylene-(meth)acrylic acid-(meth)acrylic acid alkyl ester copolymer; and ionomer resins in which the ethylene-unsaturated carboxylic acid copolymer or the ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer molecules are crosslinked with metal ions.

Examples of the metal ions used in the ionomer resin include lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, zinc ions, magnesium ions, and manganese ions. Of these metal ions, magnesium ions, and zinc ions are preferred, with sodium ions and zinc ions being more preferred.

When an ethylene-vinyl acetate copolymer, an ethylene-unsaturated carboxylic acid ester copolymer, an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, or an ionomer resin is used as the component (A) ethylene-based resin, the content of structural units derived from ethylene may be typically 98% by mass or less, preferably 96% by mass or less, and more preferably 94% by mass or less, based on the total mass of the ethylene-based resin, from the viewpoint of the expandability of the resin film. On the other hand, from the viewpoint of the blocking resistance of the resin film, this content may be typically 70% by mass or more, preferably 75% by mass or more, and more preferably 80% by mass or more.

When low-density polyethylene, linear low-density polyethylene, very low-density polyethylene, medium-density polyethylene, high-density polyethylene, or ethylene-α-olefin copolymer is used as the component (A) ethylene resin, the density (measured by the immersion method (ISO1183-1:2019) in accordance with JIS K6922-2:2018) is usually 950 kg/m ³ or less, preferably 945 kg/m ³ or less, more preferably 940 kg/m ³ or less, even more preferably 935 kg/m ³ or less, and most preferably 930 kg/m ³ or less, from the viewpoint of the expandability of the resin film. On the other hand, this density may be usually 880 kg/m ³ or more, preferably 890 kg/m ³ or more, more preferably 900 kg/m ³ or more, from the viewpoint of the blocking resistance of the resin film.

From the viewpoint of film-forming properties, the melt mass flow rate of the ethylene resin (component (A)) at 190°C may typically be 0.1 to 20 g/10 min, preferably 0.5 to 10 g/10 min. The melt mass flow rate of the ethylene resin (component (A)) is measured in accordance with JIS K7210-1:2014 at a temperature of 190°C and a load of 21.18 N.

Among these, from the viewpoint of suppressing plate-out, the ethylene-based resin component (A) is preferably an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, an ionomer resin of an ethylene-unsaturated carboxylic acid copolymer, or an ionomer resin of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer.

While not intending to be bound by theory, these compounds share the common characteristic of having a carboxyl group in their molecules, and the carboxyl group strongly interacts with the structural units derived from the polyhydric alcohol in the block copolymer of propylene and a polyhydric alcohol (component (C))) and with the metal ions contained in component (C). It is believed that this is why plate-out of component (C) the block copolymer of propylene and a polyhydric alcohol can be suppressed.

As the ethylene resin component (A), one of these may be used alone or in combination with two or more thereof.
When a mixture of two or more types of ethylene resins is used as the component (A), it goes without saying that the properties of the mixture should be determined by measuring the properties of the mixture.

(B) Propylene-Based Resin The propylene-based resin component (B) is a resin primarily containing structural units derived from propylene. Here, "primarily containing structural units derived from propylene" means that the content of structural units derived from propylene is usually 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and typically 75 to 100% by mass, based on the total mass of the propylene-based resin.
As mentioned above, the component (B) propylene-based resin does not include a block copolymer of propylene and a polyhydric alcohol, and therefore, the component (B) propylene-based resin excludes compounds corresponding to the component (C) block copolymer of propylene and a polyhydric alcohol.

Component (B) propylene-based resin inhibits plate-out of component (C) propylene and polyhydric alcohol block copolymer, thereby supporting the antistatic effect of component (C). While not intending to be bound by theory, it is believed that the functions of component (B) propylene-based resin are achieved through the following mechanism.

In the case of a resin composition comprising component (A) an ethylene-based resin and component (C) a block copolymer of propylene and a polyhydric alcohol, i.e., without component (B) a propylene-based resin, if the amount of component (C) blended is small, the component (C) forms a morphology in which the island phases of component (C) are dispersed and floating in isolation within the sea phase of component (A), failing to exhibit sufficient antistatic properties. To exhibit sufficient antistatic properties, a large amount of component (C) must be blended so that the island phases of component (C) are close together and continuous, forming an electrical path. However, component (A) and component (C) are not sufficiently miscible or compatible, and blending a large amount of component (C) results in component (C) easily plating out.

When component (B) propylene-based resin is added to this, i.e., in the case of a resin composition of component (A) ethylene-based resin, component (B) propylene-based resin, and component (C) block copolymer of propylene and polyhydric alcohol, the segments of component (C) that share a structure with component (B), i.e., the propylene polymer segments of component (C), are compatible with component (B) to form an island phase or eutectic. Therefore, even when a large amount of component (C) is blended, plate-out of component (C) is suppressed. On the other hand, from the viewpoint of forming an electrical path, the essential segments of component (C), i.e., the polyhydric alcohol polymer segments of component (C), are insufficiently miscible and compatible with component (B), and therefore, when the propylene polymer segments of component (B) and component (C) solidify/crystallize, they are discharged into the phase still in a molten state (the sea phase of component (A) when the crystallization temperature of component (A) is lower than those of components (B) and (C), or the amorphous or low-crystalline component phase of component (A) when the crystallization temperature of component (A) is higher than those of components (B) and (C)). As a result, the polyhydric alcohol polymer segments of component (C) are present at a high concentration in the phase still in a molten state, and when the phase still in a molten state solidifies, adjacent and continuous island phases, i.e., electrical paths, are formed, thereby exhibiting sufficient antistatic properties.

Examples of the propylene-based resin component (B) include propylene homopolymers and copolymers (including block copolymers and random copolymers) of propylene with one or more α-olefins (e.g., ethylene, 1-butene, 1-hexene, 1-octene, etc.).

Among these, as the component (B) propylene-based resin, a copolymer of propylene and an α-olefin is preferred from the viewpoint of miscibility and compatibility with the component (A) ethylene-based resin.

The melting point of the propylene-based resin component (B) may be typically 120°C or higher, preferably 125°C or higher, and more preferably 130°C or higher, from the viewpoint of the heat resistance and solvent resistance of the resin film. On the other hand, from the viewpoint of forming a eutectic with the propylene polymer segment of the block copolymer of propylene and polyhydric alcohol component (C), this melting point may be typically 160°C or lower, and preferably 150°C or lower.

The fusion enthalpy of the propylene-based resin (component (B)) may be typically 20 J/g or more, preferably 30 J/g or more, from the viewpoint of the heat resistance and solvent resistance of the resin film. On the other hand, from the viewpoint of the expandability of the resin film, this fusion enthalpy may be typically 90 J/g or less, preferably 88 J/g or less, more preferably 80 J/g or less, even more preferably 70 J/g or less, and even more preferably 60 J/g or less.

In this specification, the melting point and melting enthalpy of the propylene-based resin component (B) are calculated in accordance with JIS K7121-1987 using a differential scanning calorimeter (DSC measuring device) from a second melting curve (a melting curve measured during the final heating process) measured using a program that involves holding the temperature at 190°C for 5 minutes, cooling to -10°C at 10°C/min, holding the temperature at -10°C for 5 minutes, and then heating to 190°C at 10°C/min. The melting point is the peak-top temperature of the melting peak that appears in the 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.
It should also be noted that the melting peak appearing in a DSC second melting curve usually has a gently extending long base on both the high-temperature side and the low-temperature side; and that the baseline should be drawn so that the line extending the high-temperature side baseline to the low-temperature side coincides with the line extending the low-temperature side baseline to the high-temperature side in Figure 1 of JIS K7121-1987, Section 9. How to read DTA or DSC curves.

From the viewpoint of film-forming properties, the melt mass flow rate of the propylene-based resin (B) at 230°C may be preferably 0.1 to 20 g/10 min, more preferably 0.5 to 15 g/10 min, and even more preferably 1 to 10 g/10 min. The melt mass flow rate of the propylene-based resin (B) is measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 230°C and a load of 21.18 N.
The melt mass flow rate of the propylene-based resin (B) at 190°C can also be measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 21.18N.

As the propylene-based resin component (B), one of these may be used alone or in combination with two or more thereof.
When a mixture of two or more types of propylene resins (B) is used, the properties of the mixture should be determined by measuring the properties of the mixture.

(C) Block Copolymer of Propylene and Polyhydric Alcohol The above-mentioned component (C) block copolymer of propylene and polyhydric alcohol is a block copolymer having a propylene polymer segment primarily containing structural units derived from propylene and a polyhydric alcohol polymer segment primarily containing structural units derived from a polyhydric alcohol. Here, "primarily 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 to 100% by mass, based on the total mass of the propylene polymer segment. Here, "primarily containing structural units derived from a polyhydric alcohol" means that the content of structural units derived from a 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 to 100% by mass, based on the total mass of the polyhydric alcohol polymer segment. The above-mentioned component (C) block copolymer of propylene and polyhydric alcohol functions to exhibit antistatic properties.

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

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, as the polyhydric alcohol constituting the polyhydric alcohol polymer segment, from the viewpoint of forming a larger number of ether bonds relative to the number of carbon atoms and improving antistatic properties, ethylene glycol, diethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol (trimethylene glycol), and polypropylene glycol are preferred, and ethylene glycol, diethylene glycol, and polyethylene glycol are more preferred.
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 a polyhydric alcohol and one or more copolymerizable monomers.
Examples of the monomer copolymerizable with the polyhydric alcohol include compounds having two or more carboxyl groups in one molecule, such as aliphatic dicarboxylic acids, including 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, including hexamethylene diisocyanate.

The amount of propylene-derived structural units in the block copolymer of propylene and polyhydric alcohol (component (C)) may typically be 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. On the other hand, the amount of propylene-derived structural units may typically be 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. The amount of polyhydric alcohol-derived structural units in the block copolymer of propylene and polyhydric alcohol (component (C))) may typically be 70% by mass or less, preferably 60% by mass or less, and more preferably 50% by mass or more, from the viewpoint of suppressing plate-out. On the other hand, the amount of polyhydric alcohol-derived structural units may typically be 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.

The sum of the amount of structural units derived from propylene and the amount of structural units derived from polyhydric alcohol in the block copolymer of propylene and polyhydric alcohol (component (C))) may be generally 80% by mass or more, preferably 90% by mass or more, and typically 95 to 100% by mass, where the total amount of each structural unit in component (C) is 100% by mass.

The above-mentioned component (C), a block copolymer of propylene and a polyhydric alcohol, may be doped with metal ions. This can improve antistatic properties.

Examples of the metal ions include lithium ions, cesium ions, rubidium ions, potassium ions, barium ions, strontium ions, calcium ions, and sodium ions. Of these, lithium ions are preferred as metal ions from the viewpoint of improving antistatic properties.

From the viewpoint of improving antistatic properties, the content of the metal ions in the block copolymer of propylene and polyhydric alcohol (component (C)) may typically be 100 ppm or more, preferably 150 ppm or more, more preferably 300 ppm or more, and even more preferably 500 ppm or more. On the other hand, from the viewpoint of suppressing plate-out, the content of the metal ions may typically be 2000 ppm or less, preferably 1500 ppm or less, and more preferably 1000 ppm or less.

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

The melting point of the propylene polymer segment of the block copolymer of propylene and polyhydric alcohol (component (C)) may typically be (Tm - 30) to (Tm + 30)°C, preferably (Tm - 20) to (Tm + 20)°C, and more preferably (Tm - 10) to (Tm + 10)°C, from the viewpoint of forming a eutectic with the propylene-based resin (component (B)) and suppressing plate-out. Here, Tm is the melting point (unit: °C) of the propylene-based resin (component (B)).

In this specification, the melting point of the component (C) propylene and polyhydric alcohol block copolymer is calculated from 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 measuring device) according to a program that involves 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. The melting point of the propylene polymer segment is the peak-top temperature of a melting peak appearing in the temperature range of 100 to 165°C on the 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. The melting point of the polyhydric alcohol polymer segment varies depending on its composition, but in the case of a polyethylene glycol segment, for example, it is the peak-top temperature of a melting peak appearing in the temperature range of 20 to 60°C on the second melting curve. When two or more melting peaks are observed, the peak top temperature of the melting peak having the greatest peak top height is similarly taken as the melting point.
It should also be noted that the melting peak appearing in a DSC second melting curve usually has a gently extending long base on both the high-temperature side and the low-temperature side; and that the baseline should be drawn so that the line extending the high-temperature side baseline to the low-temperature side coincides with the line extending the low-temperature side baseline to the high-temperature side in Figure 1 of JIS K7121-1987, Section 9. How to read DTA or DSC curves.

From the viewpoint of film-forming properties, the melt mass flow rate at 190°C of the block copolymer of propylene and polyhydric alcohol (component (C)) is preferably 0.1 to 20 g/10 min, more preferably 0.5 to 15 g/10 min, and even more preferably 1 to 10 g/10 min. The melt mass flow rate of the block copolymer of propylene and polyhydric alcohol (component (C)) is measured in accordance with JIS K7210-1:2014 at a temperature of 190°C and a load of 21.18 N.

As the component (C), a block copolymer of propylene and a polyhydric alcohol, one or a mixture of two or more of these can be used.
When a mixture of two or more types of component (C), the block copolymer of propylene and a polyhydric alcohol, is used, it goes without saying that the properties of the mixture should be determined by measuring the properties of the mixture.

The amount of the ethylene resin (A) may be usually 99 parts by mass or less, preferably 95 parts by mass or less, and more preferably 92 parts by mass or less, from the viewpoint of antistatic properties and suppression of plate-out, where the sum of the amounts of the ethylene resin (A) and the propylene resin (B) is taken as 100 parts by mass. On the other hand, from the viewpoint of the expandability of the resin film, this amount may be usually 20 parts by mass or more, preferably 35 parts by mass or more, more preferably 45 parts by mass or more, and even more preferably 55 parts by mass or more.
In one embodiment, the amount of the ethylene-based resin (A) is typically 20 parts by mass or more and 99 parts by mass or less, preferably 20 parts by mass or more and 95 parts by mass or less, 20 parts by mass or more and 92 parts by mass or less, 35 parts by mass or more and 99 parts by mass or less, 35 parts by mass or more and 95 parts by mass or less, 35 parts by mass or more and 92 parts by mass or less, 45 parts by mass or more and 99 parts by mass or less, 45 parts by mass or more and 95 parts by mass or less, 45 parts by mass or more and 92 parts by mass or less, 55 parts by mass or more and 99 parts by mass or less, 55 parts by mass or more and 95 parts by mass or less, or 55 parts by mass or more and 92 parts by mass or less, where the sum of the amount of the ethylene-based resin (A) and the amount of the propylene-based resin (B) is 100 parts by mass.

The amount of the propylene-based resin (B) may be usually 1 part by mass or more, preferably 5 parts by mass or more, and more preferably 8 parts by mass or more, from the viewpoint of antistatic properties and plate-out suppression, where the sum of the amount of the ethylene-based resin (A) and the amount of the propylene-based resin (B) is 100 parts by mass. On the other hand, from the viewpoint of the expandability of the resin film, this amount may be usually 80 parts by mass or less, preferably 65 parts by mass or less, more preferably 55 parts by mass or less, and even more preferably 45 parts by mass or less.
In one embodiment, the amount of the propylene-based resin of component (B) is typically 1 part by mass or more and 80 parts by mass or less, preferably 1 part by mass or more and 65 parts by mass or less, 1 part by mass or more and 55 parts by mass or less, 1 part by mass or more and 45 parts by mass or less, 5 parts by mass or more and 80 parts by mass or less, 5 parts by mass or more and 65 parts by mass or less, 5 parts by mass or more and 55 parts by mass or less, 5 parts by mass or more and 45 parts by mass or less, 8 parts by mass or more and 80 parts by mass or less, 8 parts by mass or more and 65 parts by mass or less, 8 parts by mass or more and 55 parts by mass or less, or 8 parts by mass or more and 45 parts by mass or less, where the sum of the amount of the ethylene-based resin of component (A) and the amount of the propylene-based resin of component (B) is 100 parts by mass.

The blending amount of the block copolymer of propylene and polyhydric alcohol (Component (C)) may be usually 1 part by mass or more, preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, per 100 parts by mass of the sum of the blending amount of the ethylene resin (Component (A)) and the propylene resin (Component (B)), while from the viewpoint of suppressing plate-out, it may be usually 39 parts by mass or less, preferably 35 parts by mass or less, more preferably 32 parts by mass or less, and even more preferably 29 parts by mass or less.
In one embodiment, the amount of the block copolymer of propylene and polyhydric alcohol (C) is typically 1 part by mass or more and 39 parts by mass or less, preferably 1 part by mass or more and 35 parts by mass or less, 1 part by mass or more and 32 parts by mass or less, 1 part by mass or more and 29 parts by mass or less, 5 parts by mass or more and 39 parts by mass or less, 5 parts by mass or more and 35 parts by mass or less, 5 parts by mass or more and 32 parts by mass or less, 5 parts by mass or more and 29 parts by mass or less, 10 parts by mass or more and 39 parts by mass or less, 10 parts by mass or more and 35 parts by mass or less, 10 parts by mass or more and 32 parts by mass or less, 10 parts by mass or more and 29 parts by mass or less, 15 parts by mass or more and 39 parts by mass or less, 15 parts by mass or more and 35 parts by mass or less, 15 parts by mass or more and 32 parts by mass or less, or 15 parts by mass or more and 29 parts by mass or less.

The mass ratio of the amount of component (B) propylene resin to the amount of component (C) propylene and polyhydric alcohol block copolymer (amount of component (B)/amount of component (C)) is preferably 0.4 or more, preferably 0.6 or more, and more preferably 0.8 or more, from the viewpoint of suppressing plate-out. On the other hand, this mass ratio is preferably 10 or less, more preferably 6 or less, from the viewpoint of forming a eutectic between component (B) and the propylene polymer segment of component (C) and suppressing plate-out, even when there is a large difference between their melting points.

The melt mass flow rate of the component (A) ethylene resin at 190°C may be lower than the melt mass flow rate of the component (C) propylene and polyhydric alcohol block copolymer at 190°C, preferably at least half that value. When the melt mass flow rates of both components satisfy the above relationship, the polyhydric alcohol polymer segments of component (C) become elongated island phases upon exposure to shear stress, facilitating the formation of electrical flow paths and enabling the development of sufficient antistatic properties.

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, with the layer forming at least one surface of the resin film. The resin film of the present invention may be a monolayer film or a multilayer film. 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 film selvages (removed portions on both ends of the film that exceed the set width range generated during film production).

The method for producing the resin film of the present invention is not particularly limited, and known film production methods can be used. Examples of the film production method include a film production method using a calendar roll rolling film production apparatus equipped with a calendar roll processing machine and a take-up device; a film production method using a T-die film production apparatus equipped with an extruder, a T-die, and a take-up device; and a film production method using an inflation film production apparatus equipped with an extruder, a circular die, an inflation device, and a take-up device with a nip mechanism.

Examples of the calender roll rolling machine include an upright three-roll machine, an upright four-roll machine, an L-shaped four-roll machine, an inverted L-shaped four-roll machine, and a Z-roll machine.
Examples of the extruder include a single-screw extruder, a co-rotating twin-screw extruder, and a counter-rotating twin-screw extruder.
Examples of the T-die include a manifold die, a fishtail die, and a coat hanger die.

The thickness of the resin film of the present invention is not particularly limited and can be selected appropriately taking into consideration the intended use of the resin film. When the resin film of the present invention is used as a substrate film for dicing tape, its thickness may typically be 30 to 300 μm, preferably 50 to 200 μm, and more preferably 70 to 150 μm. The thickness here refers to the overall thickness of the resin film including at least one layer formed from the resin composition of the present invention (if it consists of multiple layers, the total thickness of those layers).

The surface resistivity of the resin film of the present invention may be usually 1×10 ⁶ to 1×10 ¹¹ Ω/□, preferably 1×10 ⁷ to 1×10 ¹⁰ Ω/□, more preferably 1×10 ⁸ to 1×10 ¹⁰ Ω/□, and even more preferably 1×10 ⁸ to 1×10 ⁹ Ω/□. When the resin film of the present invention has a surface resistivity within the above range, it can be suitably used as a base film for antistatic dicing tape.

In this specification, surface resistivity is measured in accordance with JIS K6911:1995, sections 5.13 Resistivity and 5.13.2 Laminated Plates, except that the test specimen is pretreated by leaving it in an environment at a temperature of 25°C and a relative humidity of 50% for 24 hours and the resistivity is measured in an environment at a temperature of 25°C and a relative humidity of 50%. A probe is attached to the test specimen with a load of 30 N, a voltage of 100 V is applied, and the surface resistivity (unit: Ω/□) is measured 30 seconds later. The test specimen is a square film piece with sides measuring 10 cm taken from a resin film (typically a substrate film for dicing tape).

The 5% strain tensile stress in the machine direction of the resin film of the present invention is typically 15 MPa or less (greater than 0 MPa), preferably 12 MPa or less (greater than 0 MPa), more preferably 2 to 10 MPa, and even more preferably 3 to 8 MPa. The 10% strain tensile stress in the machine direction of the resin film of the present invention is typically 20 MPa or less (greater than 0 MPa), preferably 18 MPa or less (greater than 0 MPa), more preferably 2 to 15 MPa, and even more preferably 4 to 12 MPa. The 20% strain tensile stress in the machine direction of the resin film of the present invention is typically 20 MPa or less (greater than 0 MPa), preferably 18 MPa or less (greater than 0 MPa), more preferably 3 to 15 MPa, and even more preferably 6 to 12 MPa. The 100% strain tensile stress in the machine direction of the resin film of the present invention is typically 25 MPa or less (greater than 0 MPa), preferably 20 MPa or less (greater than 0 MPa), more preferably 4 to 18 MPa, and even more preferably 8 to 15 MPa. When the resin film of the present invention has a strain tensile stress within the above range, it can be suitably used as a substrate film for an antistatic dicing tape having excellent expandability.

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 20% strain tensile stress is greater than the 10% strain tensile stress, and the 100% strain tensile stress is greater than the 20% strain tensile stress. When the machine direction strain tensile stresses of the resin film of the present invention satisfy the above-mentioned relationship, necking is strongly suppressed, making the film suitable for use as a base film for antistatic dicing tape with excellent expandability. 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.

3. Dicing Tape The dicing tape of the present invention is a dicing tape using the resin film of the present invention as a base film. The dicing tape of the present invention is usually produced by forming a pressure-sensitive adhesive layer directly or via an anchor coat on one side of the resin film of the present invention, and then slitting it to a desired width.

The adhesive used to form the adhesive layer is not particularly limited, and any adhesive can be used. Examples of adhesives used to form the adhesive layer include acrylic adhesives such as poly(meth)acrylic acid alkyl esters and copolymers of (meth)acrylic acid alkyl esters with other monomers; rubber adhesives such as natural rubber and butyl-isoprene rubber; polyurethane adhesives; polyester adhesives; polystyrene adhesives; and silicone adhesives.

The adhesive used to form the adhesive layer is preferably one with excellent transparency, as it ensures the transparency required of dicing tape, for example, sufficient visibility during laser marking. Here, "an adhesive with excellent transparency" refers to an adhesive with 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 can be calculated as the ratio of the integrated area of the transmission spectrum of the adhesive at wavelengths of 380 to 780 nanometers, measured using a Shimadzu Corporation "Solid Spec-3700" (product name) spectrophotometer and a quartz cell with an optical path length of 10 mm, to the integrated area of the transmission spectrum assuming 100% transmittance over the entire wavelength range of 380 to 780 nanometers.

Preferably, the adhesive used to form the adhesive layer is one whose adhesive strength can be reduced by heat curing or active energy ray curing. This reduction in adhesive strength allows the dicing tape to be easily and cleanly peeled off from the workpiece (processed object) without leaving any adhesive residue. It also reduces the amount of static electricity generated when peeling the dicing tape from the workpiece. Examples of adhesives whose adhesive strength can be reduced by heat curing or active energy ray curing include adhesives containing 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 such adhesives with at least one of an isocyanate-based curing agent, a photopolymerization initiator, and an organic peroxide.

As the adhesive for forming the adhesive layer, an antistatic adhesive is also preferred. The surface resistivity of the adhesive layer formed using the antistatic adhesive may usually be 1 x ¹⁰ to 1 x ¹⁰ Ω/□, preferably 1 x ¹⁰ to 1 x ¹⁰ Ω/□, more preferably 1 x ¹⁰ to 1 x ¹⁰ Ω/□, and even more preferably 1 x ¹⁰ to 1 x ¹⁰ Ω/□. Examples of the antistatic adhesive include adhesives disclosed in JP 2007-191532 A, JP 2008-007702 A, JP 2009-242745 A, and WO 2015/030186 A.

The adhesive used to form the adhesive layer can be one of these or a mixture of two or more of them.

The thickness of the adhesive layer is not particularly limited and can be any thickness. The thickness of the adhesive layer is typically 1 to 25 μm, preferably approximately 5 to 20 μm.

The present invention will be explained below using examples, but the present invention is not limited to these.

Measurement method (i) Surface resistivity Except that 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, the surface resistivity (unit: Ω/□) was measured in accordance with JIS K6911:1995, 5.13 Resistivity, 5.13.2 Laminated Plate, using a resistivity meter "Hiresta-UP MCP-HT450 (trade name)" and a double ring probe "MCP-JB03 (trade name)" from Nitto Seiko Analytech Co., Ltd. The probe was pressed onto the test specimen with a load of 30 N, a voltage of 100 V was applied, and the surface resistivity (unit: Ω/□) was measured 30 seconds later. A square film piece with a side length of 10 cm was taken from the dicing tape substrate film and used as the test specimen. Note that the notation "1.0E+10" in the table means that the surface resistivity was 1.0 x ¹⁰ Ω/□. Moreover, >1.0E+11 means that the surface resistivity was greater than 1.0×10 ¹¹ Ω/□.

(ii) Plate-out index (ΔG)
The film-forming apparatus used was the one shown in the conceptual diagram of Figure 1 (a film-forming apparatus equipped with an extruder 1 having a diameter of 40 mm, a T-die 2 having a resin outlet width of 600 mm, and a take-up device having a mechanism for nipping between a smooth roll (mirror-finish metal roll) 4 having a diameter of 150 mm and a grain roll (matt-finish rubber roll) 5 having a diameter of 250 mm). Measurements were performed in accordance with JIS Z8741-1997 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, except that the 8-degree specular gloss value (G ₀ ) of the smooth roll surface of the film-forming apparatus (a location 5 cm toward the center in the width direction from the location where the right edge in the width direction of the molten film contacts the smooth roll surface; hereinafter referred to as the "predetermined location") was applied to measure the specular gloss value of the curved surface, and the incident angle and reflection angle of light were set to 8 degrees. At this time, a jig was used to fit the smooth roll and the color difference meter and to ensure that the angle of incidence and angle of reflection of light were 8 degrees. Next, 3 kg of the resin composition was continuously extruded from the T-die 2 as a molten film 3, and the extruded molten film 3 was supplied and introduced between the rotating smooth roll 4 and the rotating textured roll 5, and pressed between the smooth roll 4 and the textured roll 5. The pressed molten film 3 was wrapped around the smooth roll 4 and sent to the next rotating roll 6, producing a film 7 with a thickness of 100 μm. At this time, the resin temperature at the T-die outlet was 210 ° C., the surface temperature of the smooth roll 4 was 25 ° C., the temperature of the cooling water flowing through the textured roll 5 was 25 ° C., and the take-up speed was 4 m / min. After film production (after all 3 kg of the resin composition was extruded from the T-die), the 8-degree specular gloss value (G ₁ ) of a predetermined location on the smooth roll surface of the film-forming apparatus was measured in the same manner as the 8-degree specular gloss value (G ₀ ). The plate-out index (ΔG) 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=(1-G ₁ /G ₀ )×100 (1)

(iii) Plate-out state (visual observation)
The state of the smooth roll surface was visually observed, and the state of plate-out was judged according to the following criteria.
A: Plate-out is sufficiently suppressed.
B: Plate-out is almost completely suppressed.
C: Plate-out is observed.
D: Significant plate-out is observed.

When the plate-out condition (visual observation) in the above test (iii) was ranked A, ΔG was generally 10% or less. When ranked B, ΔG was generally between 10% and 20%. When ranked C, ΔG was generally between 20% and 30%. When ranked D, ΔG was generally above 30%.

(iv) Tensile Test In accordance with JIS K7127:1999, a tensile tester "Autograph AGS-1kNG" (product name) manufactured by Shimadzu Corporation was used to punch out a sample from the film into the shape of a type 5 test piece of the above standard (see Figure 2 of the JIS standard) with the machine direction of the film being the tensile direction. A tensile test was carried out at a tensile speed of 200 mm/min and a temperature of 23°C to obtain a stress-strain curve in the machine direction (hereinafter abbreviated as "SS curve"). From the obtained SS curve in the machine direction, the 5% strain tensile stress in the machine direction (listed as "5% MD" in the table), the 10% strain tensile stress in the machine direction (listed as "10% MD" in the table), the 20% strain tensile stress in the machine direction (listed as "20% MD" in the table), and the 100% strain tensile stress in the machine direction (listed as "100% MD" in the table) were calculated according to Section 10.1 of JIS K7161-1:2014. The unit of these strain tensile stresses is MPa.

Raw materials used : (A) Ethylene-based resin (A-1): Mitsui-Dow Polychemical Co., Ltd.'s zinc ion-crosslinked ionomer resin "Himilan 1855" (trade name), melt mass flow rate (190°C, 21.18N) 1.0 g/10 min, melting point 83°C. According to JP 2013-098443 A, this is an ionomer resin obtained by crosslinking 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) "Himilan 1652" (trade name), an ionomer resin crosslinked with zinc ions from Mitsui-Dow Polychemicals Co., Ltd., has a melt mass flow rate (190°C, 21.18N) of 5.5 g/10 min and a melting point of 96°C. According to JP 2008-052011 A, this is an ionomer resin in which an ethylene-methacrylic acid copolymer is crosslinked with zinc ions. The content of structural units derived from methacrylic acid is 16% by mass (the content of structural units derived from ethylene is 84% by mass).
(A-3) "Himilan 1707" (trade name), an ionomer resin crosslinked with sodium ions, manufactured by Dow Mitsui Polychemicals Co., Ltd., with a melt mass flow rate (190°C, 21.18N) of 0.9 g/10 min and a melting point of 86°C.
(A-4) Ethylene-methacrylic acid copolymer "Nucrel N0903HC" (trade name) from Dow Mitsui Polychemicals Co., Ltd., melt mass flow rate (190°C, 21.18N) 2.5 g/10 min, content of structural units derived from methacrylic acid 9% by mass (content of structural units derived from ethylene 91% by mass), melting point 98°C.
(A-5) Tosoh Corporation's ethylene-vinyl acetate copolymer "Ultrathene 515" (trade name), melt mass flow rate 2.5 g/10 min, content of structural units derived from vinyl acetate 6% by mass (content of structural units derived from ethylene 94% by mass), melting point 100°C.
(A-6) Tosoh Corporation's low-density polyethylene "Petrothene 339" (trade name), melt mass flow rate (190°C, 21.18N) 3.0g/10min, density 924kg/m ³ , melting point 109°C.
(A-7) High density polyethylene "Hi-Zex 3300F" (trade name) manufactured by Prime Polymer Co., Ltd., melt mass flow rate (190°C, 21.18N) 1.1 g/10 min, density 949 kg/m ³ , melting point 131°C.

(B) Propylene-based resin (B-1) Japan Polypropylene Corporation's propylene-ethylene copolymer "Welnex RFX4V" (trade name), melt mass flow rate (230 ° C, 21.18 N) 6.0 g / 10 min, melt mass flow rate (190 ° C, 21.18 N) 3.0 g / 10 min, melting point 131 ° C, melting enthalpy 55 J / g. According to JP 2017-100357 A, it is a propylene-ethylene block copolymer. The content of structural units derived from ethylene is 29 mol% (21 mass% equivalent) (the content of structural units derived from propylene is 71 mol% (79 mass% equivalent)).
(B-2) Sumitomo Chemical Co., Ltd.'s propylene/1-butene copolymer "Tafthren T3732" (trade name), melt mass flow rate (230°C, 21.18N) 3 g/10 min, melt mass flow rate (190°C, 21.18N) 1.3 g/10 min, melting point 129°C, melting enthalpy 32 J/g. According to JP 2005-280173 A, it is a propylene/1-butene random copolymer. The content of structural units derived from 1-butene is 5% by mass (the content of structural units derived from propylene is 95% by mass).
(B-3) Propylene-ethylene random copolymer "F-730NV" (trade name) manufactured by Prime Polymer Co., Ltd., having a melt mass-flow rate (230°C, 21.18 N) of 7.0 g/10 min, a melt mass-flow rate (190°C, 21.18 N) of 3.0 g/10 min, a melting point of 139°C, a melting enthalpy of 88 J/g, and a content of structural units derived from ethylene of 3.4% by mass (a content of structural units derived from propylene of 96.6% by mass).

(C) Block copolymer of propylene and polyhydric alcohol:
(C-1) A block copolymer having a propylene polymer segment and a polyethylene glycol segment, "Pelectron PVH" (trade name), having a melt mass flow rate (190°C, 21.18 N) of 8 g/10 min, a content of structural units derived from propylene of 60% by mass, a content of structural units derived from polyethylene glycol of 40% by mass, a melting point of the propylene polymer segment of 134°C, a melting point of the polyethylene glycol segment of 34°C, and containing 770 ppm of lithium ions.
(C-2) Block copolymer having a propylene polymer segment and a polyethylene glycol segment, "Pelectron LMP-FS" (trade name), melt mass flow rate (190°C, 21.18 N) 15 g/10 min, content of structural units derived from propylene 56% by mass, content of structural units derived from polyethylene glycol 44% by mass, melting point of propylene polymer segment 113°C, melting point of polyethylene glycol segment 34°C, and containing 180 ppm of lithium ions.
(C-3) Block copolymer having a propylene polymer segment and a polyethylene glycol segment, "Pelectron PVL" (trade name), melt mass flow rate (190°C, 21.18 N) 15 g/10 min, content of structural units derived from propylene 59% by mass, content of structural units derived from polyethylene glycol 41% by mass, melting point of propylene polymer segment 132°C, melting point of polyethylene glycol segment 33°C, and containing 180 ppm of lithium ions.

Example 1
A resin composition containing 80 parts by mass of the component (A-1), 20 parts by mass of the component (B-1), and 20 parts by mass of the component (C-1) was used, and the film-forming apparatus (including an extruder 1, a T-die 2, and a take-up device having a mechanism for nipping a smooth roll (mirror-finish metal roll) 4 and a textured rubber roll) 5, as shown in the conceptual diagram of FIG. 1, was used. The resin composition was continuously extruded from the T-die 2 as a molten film 3. Next, the extruded molten film 3 was fed between the rotating smooth roll 4 and the rotating textured roll 5, and pressed between the smooth roll 4 and the textured roll 5. Subsequently, the pressed molten film 3 was wrapped around the smooth roll 4 and sent to the next rotating roll 6, and a film 7 having a thickness of 100 μm was produced. At this time, the resin temperature at the T-die outlet was 210 ° C., the surface temperature of the smooth roll 4 was 25 ° C., the temperature of the cooling water flowing through the textured roll 5 was 25 ° C., and the take-up speed was 4 m/min.
The above tests (i) to (iv) were carried out, and the results are shown in Table 1.

Examples 2 to 25
A film was produced in the same manner as in Example 1, except that the formulation of the resin composition was changed to one shown in any one of Tables 1 to 3. The above tests (i) to (iv) were carried out. The results are shown in any one of Tables 1 to 3.

It has been found that the resin composition of the present invention suppresses plate-out, and that resin films formed using this composition have sufficient antistatic properties. It has been found that the preferred resin composition of the present invention suppresses plate-out, and that resin films formed using this composition have sufficient antistatic properties and excellent expandability. Therefore, it has been considered that resin films formed using the resin composition of the present invention are suitable as substrate films for antistatic dicing tape.

It will be obvious to those skilled in the art that the resin composition of the present invention has the above-mentioned desirable properties and can therefore be suitably used as a material for injection molded products, extrusion molded products, and the like.
Furthermore, since the resin film formed using the resin composition of the present invention has the preferred properties as described above, it will be obvious to those skilled in the art that it can also be suitably used as a film or tape for semiconductor production other than dicing tape, for example, backgrind tape (used to protect the circuit surface in the process of thinly grinding a wafer) or die attach film (used to adhesively stack and mount cut wafer chips).

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

Claims (9)

(A) 20 to 99 parts by mass of an ethylene-based resin,
(B) 80 to 1 parts by mass of a copolymer of propylene and an α-olefin , and (C) 1 to 39 parts by mass of a block copolymer of propylene and a polyhydric alcohol;
where :
The component (A) ethylene-based resin is an ethylene-based resin having a carboxyl group in the molecule,
The sum of the blending amount of the component (A) ethylene resin and the blending amount of the component (B) propylene and α-olefin copolymer is 100 parts by mass;
The component (B) copolymer of propylene and α-olefin does not include a block copolymer of propylene and a polyhydric alcohol.
Resin composition. The resin composition according to claim 1, wherein the mass ratio of the blending amount of the component (B) propylene and α-olefin copolymer to the blending amount of the component (C) propylene and polyhydric alcohol block copolymer is 0.4 or more. the melt mass flow rate of the component (A) ethylene-based resin is lower than the melt mass flow rate of the component (C) block copolymer of propylene and polyhydric alcohol;
Here, the melt mass flow rate of the component (A) ethylene resin and the melt mass flow rate of the component (C) propylene and polyhydric alcohol block copolymer are measured in accordance with JIS K7210-1:2014 under conditions of a temperature of 190°C and a load of 21.18 N.
The resin composition according to claim 1 or 2. the melting point of the propylene polymer segment of the component (C) propylene and polyhydric alcohol block copolymer is (Tm-30) to (Tm+30)°C;
Here, Tm is the melting point (unit: °C) of the component (B) propylene and α-olefin copolymer .
The resin composition according to any one of claims 1 to 3. The resin composition according to any one of claims 1 to 4, wherein the component (A) ethylene-based resin comprises at least one selected from the group consisting of an ethylene-unsaturated carboxylic acid copolymer, an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer, an ionomer resin of an ethylene-unsaturated carboxylic acid copolymer, and an ionomer resin of an ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid ester copolymer. The resin composition according to any one of claims 1 to 5 , which is used for a base film of a dicing tape. A substrate film for a dicing tape, comprising at least one layer formed from the resin composition according to any one of claims 1 to 6 . A dicing tape having a substrate film for dicing tape, the substrate film comprising at least one layer formed from the resin composition according to any one of claims 1 to 6 . A resin film comprising at least one layer formed from the resin composition according to any one of claims 1 to 5 .