Elastomer composition and film thereof

Abstract

To provide an elastomer composition and a film thereof that are suitable as materials for soft and transparent products. [Solution] An elastomer composition comprising (A) 100 parts by mass of a copolymer elastomer of α-olefin and polyene, preferably a copolymer elastomer of α-olefin and non-conjugated diene, (B) 0.1 to 300 parts by mass of polyolefin, preferably polypropylene, and (C) 0.01 to 30 parts by mass of a photopolymerization initiator, preferably a hydrogen abstraction type photopolymerization initiator, and a film thereof. The heat resistance of the film can be increased by irradiation with active energy rays.

Description

[Technical Field]

[0001] The present invention relates to elastomer compositions and films thereof. [Background technology]

[0002] Copolymer elastomers of α-olefins and polyenes, such as copolymer elastomers of ethylene, propylene, and dienes (EPDM), do not have double bonds in their main chain, and therefore possess excellent heat resistance, aging resistance, ozone resistance, and weather resistance. They have long been widely used in various elastomer products for automotive, industrial, and construction applications. Furthermore, because copolymer elastomers of α-olefins and polyenes are flexible and highly transparent, they are considered suitable as materials for flexible, or flexible and transparent, products or components, such as automotive surface protection films like chipping films, and automotive decorative films like dressing films, marking films, taillight seals, and emblem seals. They are also considered suitable as materials for umbrellas, raincoats, bags, and patches. However, their use as materials for flexible products, particularly flexible and transparent products, has not been proposed until now. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2010-180370 [Patent Document 2] Japanese Patent Publication No. 2005-019315 [Patent Document 3] International Publication No. 2021 / 060446 [Overview of the project] [Problems that the invention aims to solve]

[0004] The object of the present invention is to provide an elastomer composition and a film thereof that are suitable as materials for flexible products. [Means for solving the problem]

[0005] As a result of diligent research, the inventors have found that the above problem can be solved by a specific elastomer composition.

[0006] In other words, the embodiments of the present invention are as follows. [1]. An elastomer composition comprising (A) a copolymer elastomer of α-olefin and polyene, (B) a polyolefin (excluding those corresponding to the copolymer elastomer of α-olefin and polyene mentioned above), and (C) a photopolymerization initiator, wherein the amount of the photopolymerization initiator (C) is 0.01 to 30 parts by mass per 100 parts by mass of the copolymer elastomer of α-olefin and polyene mentioned above. [2]. The elastomer composition according to item [1], wherein the above component (A) copolymer elastomer of α-olefin and polyene comprises a copolymer elastomer of α-olefin and non-conjugated polyene. [3]. The elastomer composition according to item [1] or [2], wherein the copolymer elastomer of component (A) α-olefin and polyene comprises a copolymer elastomer of ethylene, propylene, and one or more dienes selected from the group consisting of 5-ethylidene-2-norbornene, tricyclo[4.3.0.12,5]deca-3,7-diene, and 1,4-hexadiene. [4]. The elastomer composition according to any one of items [1] to [3], wherein the above component (C) photopolymerization initiator comprises a hydrogen abstraction type photopolymerization initiator. [5]. An elastomer composition according to any one of items [1] to [4], which does not contain an intramolecular cleavage type photopolymerization initiator. [6]. The elastomer composition according to any one of items [1] to [5], wherein the amount of component (B) polyolefin is 0.1 to 100 parts by mass per 100 parts by mass of the copolymer elastomer of component (A) α-olefin and polyene. [7]. The elastomer composition according to any one of items [1] to [6], wherein the above component (B) polyolefin contains polypropylene. [8]. A film comprising the elastomer composition described in any one of items [1] to [7]. [9]. Articles containing the films described in item [8]. [Effects of the Invention]

[0007] The elastomer composition of the present invention exhibits excellent flexibility and significantly improved moldability. The preferred elastomer composition of the present invention also has good transparency, heat resistance, and color tone. Therefore, the elastomer of the present invention can be suitably used as a material for base films such as surface protection films and decorative films, for example, surface protection films for automobiles such as chipping films, and decorative films for automobiles such as dressing films, marking films, taillight seals, and emblem seals. Therefore, the elastomer of the present invention can be suitably used as a material for umbrellas, raincoats, bags, and patches. [Modes for carrying out the invention]

[0008] In this specification, the term "resin (including elastomers; hereinafter the same)" is used to include resin mixtures containing two or more resins, as well as resin compositions containing components other than resins.

[0009] In this specification, the term "film" is used interchangeably or equivalently with "sheet". In this specification, the terms "film" and "sheet" are used for those that can be industrially wound into a roll. The term "plate" is used for those that cannot be industrially wound into a roll. Also, in this specification, laminating one layer on top of another layer in order includes both directly laminating those layers and laminating with one or more other layers such as an anchor coat intervening between those layers.

[0010] In this specification, the term "or more" related to a numerical range is used to mean a certain numerical value or more than a certain numerical value. For example, 20% or more means 20% or more than 20%. The term "or less" related to a numerical range is used to mean a certain numerical value or less than a certain numerical value. For example, 20% or less means 20% or less than 20%. Also, the symbol "~" related to a numerical range is used to mean 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 numerical value larger than a certain numerical value. For example, 10~90% means 10%, more than 10% and less than 90%, or 90%. Furthermore, the upper limit and the lower limit of a numerical range can be arbitrarily combined, and arbitrarily combined embodiments should be construed. For example, from the description "usually 10% or more, preferably 20% or more. On the other hand, usually 40% or less, preferably 30% or less." or "usually 10~40%, preferably 20~30%" related to the numerical range of a certain characteristic, it should be construed that the numerical range of that certain characteristic is 10~40%, 20~30%, 10~30%, or 20~40% in one embodiment.

[0011] Unless otherwise specified or except in the case of examples, all numerical values used in this specification and the claims should be understood to be modified by the term "about". Without intending to limit the application of the doctrine of equivalents to the claims, each numerical value should be construed in light of the significant figures and by applying ordinary rounding methods.

[0012] In this specification, with respect to terms specifying shapes and geometric conditions, such as terms like parallel, orthogonal, and perpendicular, in addition to their strict meanings, states that are substantially the same shall also be included.

[0013] In this specification, when describing "including a certain substance", in one embodiment, it shall be construed as including a certain substance, consisting of a certain substance, or consisting only of a certain substance. For example, from the description "Composition A includes Substance a1 and Substance a2", in one embodiment, it shall be construed that Composition A includes 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.

[0014] 1. Elastomer composition: The elastomer composition of the present invention includes (A) a copolymer elastomer of an α-olefin and a polyene, (B) a polyolefin, and (C) a photoinitiator. Hereinafter, each component will be described.

[0015] (A) Copolymer elastomer of α-olefin and polyene: The elastomer composition of the present invention includes (A) a copolymer elastomer of an α-olefin and a polyene. Since the component (A) is amorphous or low-crystalline, it has elastomeric properties and functions to impart excellent flexibility to a molded article such as a film obtained using the elastomer composition of the present invention. Further, since the (A) copolymer elastomer of an α-olefin and a polyene is amorphous or low-crystalline, it has transparency and functions to impart good transparency to a molded article such as a film obtained using the preferred elastomer composition of the present invention.

[0016] In this specification, amorphous or low-crystallinity means that, in the crystallization curve measured using a Diamond DSC differential scanning calorimeter from PerkinElmer Japan Co., Ltd. in accordance with JIS K7121-1987, with a temperature program of holding at 190°C for 5 minutes and cooling to -50°C at a cooling rate of 10°C / min, no peak associated with crystallization (hereinafter referred to as "crystallization peak") is observed, or the peak top temperature of the crystallization peak (hereinafter referred to as "crystallization temperature") is 90°C or lower. Here, if there are two or more crystallization peaks, the peak top temperature of the crystallization peak with the highest peak height is taken as the crystallization temperature. (A) The crystallization temperature of the copolymer elastomer of α-olefin and polyene may be preferably 75°C or lower, more preferably 60°C or lower, even more preferably 50°C or lower, and even more preferably 40°C or lower. (A) In one embodiment, the copolymer elastomer of α-olefin and polyene may not show any crystallization peak.

[0017] The above α-olefin is an alkene having a carbon-carbon double bond at the α-position. Examples of the above α-olefin include ethylene, propylene, 1-butene, 1-hexene, 1-octene, and 4-methylpentene-1. One or more of these can be used as the above α-olefin.

[0018] The above polyene is an alkene having two or more carbon-carbon double bonds in one molecule. Examples of the above polyene include non-conjugated polyenes (polyenes in which each carbon-carbon double bond is separated by two or more carbon-carbon single bonds), conjugated polyenes (polyenes having a conjugated diene structure in which two carbon-carbon double bonds are separated by one carbon-carbon single bond), and polyenes having an allene structure (a diene in which two carbon-carbon double bonds are adjacent). Among these, (A) from the viewpoint of making the copolymer elastomer of α-olefin and polyene not having double bonds in the main chain, the above non-conjugated polyene is preferred.

[0019] Examples of the above-mentioned non-conjugated polyenes include non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene, bicyclo[2.2.1]hepta-2-ene (norbornene), 5-ethylidene-2-norbornene (ethylidenenorbornene), and tricyclo[4.3.0.12,5]deca-3,7-diene (dicyclopentadiene), as well as non-conjugated trienes such as 1,3,7-octatriene, 1,5,9-decatriene, (Z)-4-ethylidene-8-methyl-1,7-nonadiene, and bicyclo[2.2.1]hepta-2,5-diene.

[0020] One or more of the above polyenes can be used.

[0021] (A) The copolymer elastomer of α-olefin and polyene may preferably include a copolymer elastomer of α-olefin and non-conjugated polyene, more preferably include an α-olefin and non-conjugated diene copolymer elastomer other than ethylene and ethylene, even more preferably include an ethylene, propylene, and non-conjugated diene copolymer elastomer, and even more preferably include an ethylene, propylene, and one or more non-conjugated dienes selected from the group consisting of ethylene, propylene, and 5-ethylidene-2-norbornene (ethylidenenorbornene), tricyclo[4.3.0.12,5]deca-3,7-diene (dicyclopentadiene), and 1,4-hexadiene.

[0022] (A) Mooney viscosity (ML) measured according to ASTM D1646 for copolymer elastomers of α-olefin and polyene, using an L-type rotor, with a preheating time of 1 minute, rotor rotation time of 4 minutes, and a test temperature of 125°C. 1+4 From the viewpoint of film formation, the temperature (125°C) is preferably 70 or less, more preferably 50 or less, even more preferably 40 or less, and most preferably 30 or less. On the other hand, from the viewpoint of mechanical strength, it is preferably 10 or more, and more preferably 15 or more.

[0023] (A) The copolymer elastomer of α-olefin and polyene may contain constituent units derived from monomers other than α-olefin and polyene (hereinafter referred to as "other monomers"), to the extent that it does not contradict the objectives of the present invention. Examples of the above other monomers include unsaturated carboxylic acids such as (meth)acrylic acid, alkyl esters of (meth)acrylate such as methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate, acid anhydrides of unsaturated carboxylic acids such as maleic anhydride, aromatic vinyl compounds such as styrene, and polymerizable compounds having a carbon-carbon double bond such as vinyl acetate. One or more of these other monomers can be used. The content of constituent units derived from the above other monomers in the copolymer elastomer of (A) α-olefin and polyene may be 10% by mass or less, 6% by mass or less, 3% by mass or less, 1% by mass or less, or 0 to 0.5% by mass in one embodiment, with the total sum of all constituent units of component (A) being 100% by mass.

[0024] (A) The copolymer elastomer of α-olefin and polyene may, in one preferred embodiment, not contain any of the other monomers mentioned above. Here, "not containing any of the other monomers mentioned above" means that the other monomers are not intentionally used. Therefore, "not containing any of the other monomers mentioned above" can be rephrased as the content of constituent units derived from the other monomers in component (A) being typically 0.1% by mass or less, preferably 0.05% by mass or less, more preferably 0.01% by mass or less, and even more preferably 0 to 0.001% by mass.

[0025] (A) The copolymer elastomer of α-olefin and polyene may preferably be polymerized using a metallocene catalyst, from the viewpoint of flexibility.

[0026] (A) One or more of these can be used as copolymer elastomers of α-olefin and polyene.

[0027] (B) Polyolefins: The elastomer composition of the present invention contains (B) polyolefin. (B) polyolefin enhances the moldability when forming films or the like using the elastomer composition of the present invention.

[0028] (B) Polyolefin is a resin that mainly contains α-olefins (for example, ethylene, propylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene). Here, "mainly containing α-olefins" means that the content of constituent units derived from α-olefins in (B) polyolefin is 60% by mass or more, with the total sum of all constituent units being 100% by mass. Also, (A) copolymer elastomers of α-olefin and polyene, in other words, those containing constituent units derived from polyene, are excluded from (B) polyolefin. The content of constituent units derived from α-olefins in (B) polyolefin is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95-100% by mass.

[0029] (B) Examples of polyolefins include ethylene resins, propylene resins, 1-butene resins, and 4-methyl-1-pentene resins.

[0030] The above-mentioned ethylene-based resin is a resin that mainly contains constituent units derived from ethylene. The content of constituent units derived from ethylene in the above-mentioned ethylene-based resin is usually 50% by mass or more, preferably 60% by mass or more, more preferably 65% ​​by mass or more, and typically 70 to 100% by mass, based on the total amount of all constituent units being 100% by mass.

[0031] Examples of the ethylene-based resins mentioned above include polyethylene such as ultra-low density polyethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, and ethylene-α-olefin copolymers such as ethylene-1-butene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer; ethylene-(meth)acrylate alkyl 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; ionomer resins in which the intermolecules of the ethylene-unsaturated carboxylic acid copolymer are crosslinked with metal ions; and ethylene-vinyl acetate copolymer.

[0032] Examples of metal ions used in the above-mentioned ionomer resin include lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, zinc ions, magnesium ions, and manganese ions.

[0033] The above-mentioned propylene-based resin is a resin that mainly contains structural units derived from propylene. The content of structural units derived from propylene in the above-mentioned propylene-based resin is usually 50% by mass or more, preferably 60% by mass or more, more preferably 65% ​​by mass or more, and typically 70 to 100% by mass, with the total sum of all structural units being 100% by mass.

[0034] Examples of the propylene-based resins mentioned above include polypropylene, such as propylene homopolymers, and copolymers of propylene with one or more α-olefins (e.g., ethylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene, etc.) (including block copolymers and random copolymers).

[0035] The above-mentioned 1-butene-based resin is a resin that mainly contains constituent units derived from 1-butene. The content of constituent units derived from 1-butene in the above-mentioned 1-butene-based resin is usually 50% by mass or more, preferably 60% by mass or more, more preferably 65% ​​by mass or more, and typically 70 to 100% by mass, with the total sum of all constituent units being 100% by mass.

[0036] Examples of the 1-butene-based resins mentioned above include 1-butene homopolymers and poly1-butenes such as copolymers (including block copolymers and random copolymers) of 1-butene with one or more α-olefins (e.g., ethylene, propylene, 1-hexene, 1-octene, and 4-methyl-1-pentene).

[0037] The above-mentioned 4-methyl-1-pentene resin is a resin that mainly contains structural units derived from 4-methyl-1-pentene. The content of structural units derived from 4-methyl-1-pentene in the above-mentioned 4-methyl-1-pentene resin is usually 50% by mass or more, preferably 60% by mass or more, more preferably 65% ​​by mass or more, and typically 70 to 100% by mass, based on the total amount of all structural units being 100% by mass.

[0038] Examples of the 4-methyl-1-pentene resins mentioned above include poly4-methyl-1-pentene, such as 4-methyl-1-pentene homopolymers and copolymers (including block copolymers and random copolymers) of 4-methyl-1-pentene with one or more α-olefins (e.g., ethylene, propylene, 1-butene, 1-hexene, and 1-octene).

[0039] (B) The polyolefin may preferably include the above-mentioned polypropylene from the viewpoint of transparency and blocking resistance.

[0040] The melt mass flow rate of (B) polyolefin, measured under conditions of 230°C and 21.18N in accordance with JIS K7210-1:2014, can be appropriately selected from the viewpoint of moldability and miscibility with copolymer elastomer of (A) α-olefin and polyene, taking into consideration the amount of (B) polyolefin used. From the viewpoint of moldability, the melt mass flow rate of (B) polyolefin may be 0.1 g / 10 min or more, preferably 1 g / 10 min or more, more preferably 3 g / 10 min, and even more preferably 10 g / 10 min or more. On the other hand, from the viewpoint of miscibility with copolymer elastomer of (A) α-olefin and polyene, the melt mass flow rate of (B) polyolefin may be 100 g / 10 min or less, more preferably 60 g / 10 min or less, and even more preferably 40 g / 10 min or less.

[0041] (B) In one preferred embodiment, the polyolefin may include a crystalline polyolefin. This can reduce the tack of the elastomer composition of the present invention and suppress molding problems. Furthermore, the flexibility of the elastomer composition of the present invention can be adjusted to a desired level by changing the amount of crystalline polyolefin included.

[0042] (B) If the polyolefin contains a crystalline polyolefin, its enthalpy of melt may be preferably 130 J / g or less, more preferably 120 J / g or less, even more preferably 110 J / g or less, and even more preferably 100 J / g or less, from the viewpoint of transparency. On the other hand, from the viewpoint of suppressing molding troubles, the above enthalpy of melt may be preferably 10 J / g or more, more preferably 20 J / g or more, even more preferably 30 J / g or more, even more preferably 40 J / g or more, and most preferably 50 J / g or more.

[0043] (B) If the polyolefin includes a crystalline polyolefin, its melting point may be 165°C or lower, preferably 160°C or lower, more preferably 155°C or lower, even more preferably 150°C or lower, even more preferably 145°C or lower, and most preferably 140°C or lower, depending on the type of (C) photopolymerization initiator, from the viewpoint of suppressing the consumption of the (C) photopolymerization initiator before irradiation with active energy rays. On the other hand, from the viewpoint of suppressing molding troubles, the above melting point may be 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher.

[0044] In this specification, the melting point and enthalpy of melting of (B) polyolefins are calculated from the DSC second melting curve (the melting curve measured during the final heating process) measured using a differential scanning calorimetry (DSC) device in accordance with JIS K7121-1987, with a program that involves holding at 230°C for 5 minutes, cooling to -50°C at 10°C / min, holding at -50°C for 5 minutes, and heating to 230°C at 10°C / min. The melting point is the peak top temperature of the melting peak appearing in the second melting curve. If two or more melting peaks are observed, the peak top temperature of the melting peak with the largest peak top height is taken as the melting point. Note that the melting peak appearing in the DSC second melting curve of polyolefins usually has a long, gradual tail on the low-temperature side; and the baseline should be drawn so that the straight line extending the high-temperature baseline towards the low-temperature side coincides with the straight line extending the low-temperature baseline towards the high-temperature side, as shown in Figure 1 of JIS K7121-1987, 9. How to Read DTA or DSC Curves.

[0045] (B) One or more of these polyolefins may be used.

[0046] (B) The amount of polyolefin can be appropriately selected from the viewpoint of moldability, taking into consideration the desired level of flexibility. The amount of polyolefin can be, from the viewpoint of moldability, usually 0.1 parts by mass or more, preferably 1 part by mass or more, and more preferably 3 parts by mass or more, per 100 parts by mass of copolymer elastomer of (A) α-olefin and polyene. Also, from the viewpoint of blocking resistance, the amount of polyolefin can be 6 parts by mass or more, or 9 parts by mass or more, in one embodiment. On the other hand, from the viewpoint of obtaining the desired level of flexibility, the amount of polyolefin can be 300 parts by mass or less, 250 parts by mass or less, 200 parts by mass or less, 150 parts by mass or less, 120 parts by mass or less, 100 parts by mass or less, 80 parts by mass or less, 60 parts by mass or less, 40 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 12 parts by mass or less, or 10 parts by mass or less, in one embodiment.

[0047] (C) Photopolymerization initiator: The elastomer composition of the present invention contains (C) a photopolymerization initiator. Component (C) generates radicals when irradiated with active energy rays, thereby crosslinking the copolymer elastomer of (A) α-olefin and polyene, and improving its heat resistance.

[0048] (C) Photopolymerization initiators are broadly classified into (C1) hydrogen abstraction type photopolymerization initiators and (C2) intramolecular cleavage type photopolymerization initiators. (C1) Hydrogen abstraction type photopolymerization initiators are compounds that become excited when they absorb light of a specific wavelength, abstract hydrogen from surrounding hydrogen donors, and generate radicals. (C2) Intramolecular cleavage type photopolymerization initiators are compounds that generate radicals when they absorb light of a specific wavelength, causing bonds at specific sites within the photopolymerization initiator itself to break.

[0049] (C1) Examples of hydrogen abstraction type photopolymerization initiators include benzophenone compounds, anthraquinone compounds, thioxanthone compounds, and hexaarylbisimidazole.

[0050] Examples of the benzophenone compounds mentioned above include benzophenone, methyl-o-benzoylbenzoate, 4-methylbenzophenone, 4,4'-bis(diethylamino)benzophenone, o-methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, and 2,4,6-trimethylbenzophenone.

[0051] Examples of the above-mentioned anthraquinone compounds include methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, and 2-amylanthraquinone.

[0052] Examples of the thioxanthone compounds mentioned above include thioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone.

[0053] Among these, (C1) benzophenone compounds are preferred as hydrogen abstraction type photopolymerization initiators from the viewpoint of suppressing discoloration of the molded article.

[0054] (C2) Examples of intramolecular cleavage-type photopolymerization initiators include alkylphenone compounds, acylphosphine oxide compounds, and oxime ester compounds.

[0055] Examples of the alkylphenone compounds mentioned above include 1-hydroxycyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-methylpropanone, 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and 2-benzyl-2-(dimethylamino)-4'-morpholinobtyrophenone.

[0056] Examples of the above-mentioned acylphosphine oxide compounds include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0057] Examples of the oxime ester compounds mentioned above include 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(o-benzoyl oxime), and ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyl oxime).

[0058] (C) When the copolymer elastomer of (A) α-olefin and polyene includes the copolymer elastomer of the α-olefin and non-conjugated polyene, the photopolymerization initiator may preferably include (C1) a hydrogen abstraction type photopolymerization initiator, and more preferably include (C1) a hydrogen abstraction type photopolymerization initiator and not include (C2) an intramolecular cleavage type photopolymerization initiator.

[0059] While not intending to be bound by theory, the following considerations explain why, from the viewpoint of heat resistance, it is preferable to use (C1) hydrogen abstraction type photopolymerization initiators when (A) the copolymer elastomer of α-olefin and polyene includes the copolymer elastomer of α-olefin and non-conjugated polyene. (C1) Hydrogen abstraction type photopolymerization initiators seek a hydrogen source in the carbon-carbon double bond in the copolymer elastomer of (A) α-olefin and polyene, and not elsewhere. In the case of the copolymer elastomer of α-olefin and non-conjugated polyene, carbon-carbon double bonds do not exist in the main chain, but only in the side chains composed of structural units derived from the non-conjugated polyene. Therefore, the crosslinking reaction proceeds exclusively, and the main chain is not cleaved. As a result, the degree of crosslinking increases, and heat resistance is sufficiently improved. On the other hand, the radicals generated by (C2) intramolecular cleavage type photopolymerization initiators act on random locations in the copolymer elastomer of (A) α-olefin and polyene. Therefore, even in the case of copolymer elastomers of α-olefin and non-conjugated polyene, crosslinking and main chain severance become competition. As a result, the degree of crosslinking is suppressed, and the improvement in heat resistance is also suppressed.

[0060] (C) The thermal decomposition initiation temperature of the photopolymerization initiator is preferably 160°C or higher, more preferably 170°C or higher, even more preferably 180°C or higher, and even more preferably 190°C or higher, from the viewpoint of suppressing decomposition before irradiation with active energy rays. (C) A higher thermal decomposition initiation temperature of the photopolymerization initiator is preferable. However, considering the heat resistance of the other components, a thermal decomposition initiation temperature of 300°C is sufficient.

[0061] Here, the thermal decomposition onset temperature is the extrapolation onset temperature of the step-like change (mass loss accompanied by endothermic activity) that appears in the temperature-mass curve measured using a thermogravimetric differential thermal analyzer with a program that holds the sample at 25°C for 5 minutes and then increases the temperature to 300°C at a rate of 10°C / min. Here, the extrapolation onset temperature is the temperature at the intersection of a straight line extending from the low-temperature baseline to the high-temperature side and a tangent line drawn at the point where the slope of the curve of the step-like change is maximum. If two or more step-like changes occur, the calculation is performed starting with the one at the lowest temperature.

[0062] (C) One or more of these can be used as photopolymerization initiators.

[0063] (C) The amount of photopolymerization initiator added is usually 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.2 parts by mass or more, and most preferably 0.3 parts by mass or more, per 100 parts by mass of the copolymer elastomer of (A) α-olefin and polyene, from the viewpoint of heat resistance. On the other hand, from the viewpoint of suppressing discoloration of the molded article, it is usually 30 parts by mass or less, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and most preferably 3 parts by mass or less.

[0064] (D) Lubricant: In one preferred embodiment, the elastomer composition of the present invention may further contain (D) a lubricant. By including (D) a lubricant in the elastomer composition of the present invention, moldability is further improved, and molded articles with good transparency can be easily obtained. By including (D) a lubricant in the elastomer composition of the present invention, film-forming properties are further improved, and films with good transparency can be easily obtained.

[0065] (D) Examples of lubricants include fatty acid-based lubricants, metal soaps, fatty acid amides, aliphatic alcohols, ester-based lubricants, hydrocarbon-based lubricants, and silicone oils.

[0066] Examples of the above-mentioned fatty acid-based lubricants include saturated fatty acids such as capric acid, lauric acid, palmitic acid, and stearic acid; unsaturated fatty acids such as oleic acid, linoleic acid, ricinoleic acid, behenic acid, and erucic acid; and hydroxy fatty acids such as 12-hydroxystearic acid.

[0067] The above-mentioned metal soaps are salts of aliphatic carboxylic acids such as fatty acids and hydroxy fatty acids with metals such as calcium, zinc, and barium. Examples of the above-mentioned metal soaps include higher fatty acid metal salts. Examples of said higher fatty acid metal salts include metal stearate salts such as calcium stearate, zinc stearate, and barium stearate; metal laurate salts such as calcium laurate, zinc laurate, and barium laurate; and metal ricinoleate salts such as calcium ricinoleate, zinc ricinoleate, and barium ricinoleate.

[0068] The above-mentioned fatty acid amides are compounds obtained by amidating fatty acids, hydroxy fatty acids, and other aliphatic carboxylic acids with an amine compound. Examples of the above-mentioned fatty acid amides include saturated higher fatty acid amides such as capric acid amide, palmitic acid amide, and stearic acid amide; unsaturated higher fatty acid amides such as oleic acid amide, linoleic acid amide, and erucic acid amide; and bis-higher fatty acid amides such as ethylenebis-stearic acid amide, ethylene-bis-oleic acid amide, and ethylene-bis-erucic acid amide.

[0069] Examples of the above-mentioned aliphatic alcohols include stearyl alcohol, lauryl alcohol, and palmityl alcohol.

[0070] Examples of the ester-based lubricants mentioned above include glycerin monostearate, glycerin monooleate, and butyl stearate.

[0071] Examples of the hydrocarbon lubricants mentioned above include paraffin wax and polyethylene wax.

[0072] (D) One or more of these can be used as lubricants.

[0073] (D) When a lubricant is used, the amount of the lubricant added may be preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of the copolymer elastomer of (A) α-olefin and polyene, from the viewpoint of reliably obtaining the effect of using the lubricant (D). On the other hand, from the viewpoint of suppressing problems caused by the bleeding out of the lubricant (D), it may be preferably 2 parts by mass or less, more preferably 1 part by mass or less.

[0074] The elastomer composition of the present invention may further contain other optional components other than (A) a copolymer elastomer of α-olefin and polyene, (B) polyolefin, and (C) a photopolymerization initiator, to the extent that it does not contradict the objectives of the present invention. Examples of the other optional components include (A) a copolymer elastomer of α-olefin and polyene and (B) resins other than polyolefin (including elastomers), heat stabilizers, antioxidants, weather-resistant stabilizers, light-resistant stabilizers, ultraviolet absorbers (excluding compounds corresponding to (C) a photopolymerization initiator), anti-fouling agents, nucleating agents, antistatic agents such as glycerin fatty acid esters, flame retardants, inorganic particles, organic particles, inorganic colorants, and organic colorants. One or more of these other optional components can be used. The amount of the other optional components is not particularly limited, as they are optional components, to the extent that it does not contradict the objectives of the present invention. The amount of the above-mentioned other optional components may be 50 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 10 parts by mass or less, 5 parts by mass or less, 3 parts by mass or less, 0 to 1 part by mass, or approximately 0.01 to 50 parts by mass per 100 parts by mass of (A) α-olefin and polyene copolymer elastomer in one embodiment.

[0075] In one embodiment, the elastomer composition of the present invention may not contain any one or more of the above-mentioned other optional components. Here, not containing any of the above-mentioned other optional components means that the component is not intentionally included. Therefore, not containing any of the above-mentioned other optional components can also be rephrased as the content of the component being less than 0.01 parts by mass, preferably 0.001 parts by mass or less, and more preferably 0 to 0.0001 parts by mass, per 100 parts by mass of the copolymer elastomer of (A) α-olefin and polyene.

[0076] 2. Method for producing elastomer compositions: The elastomer composition of the present invention can be obtained by using any melt kneader and simultaneously or in any order introducing (A) a copolymer elastomer of α-olefin and polyene, (B) polyolefin, and (C) a photopolymerization initiator, as well as any other optional components used as desired, into the melt kneader and melt kneading, preferably at a resin temperature above the melting point of (B) polyolefin and below the thermal decomposition initiation temperature of (C) photopolymerization initiator.

[0077] Examples of the above-mentioned melting and mixing machines include batch mixers such as pressure kneaders and mixers; extrusion mixers such as single-screw extruders, co-rotating twin-screw extruders, and opposite-rotating twin-screw extruders; and calender roll mixers. These may be used in any combination.

[0078] The resulting elastomer composition can be pelletized by any method and then molded into any article by any method. Pelletization can be carried out by methods such as hot cutting, strand cutting, and underwater cutting.

[0079] In another embodiment, the lump, rod, or strand-shaped elastomer composition discharged from the melt kneader may be directly sent to any molding machine to form an article.

[0080] 3. Film: The film of the present invention is a film comprising the elastomer composition of the present invention. In one typical embodiment, the film of the present invention is a film made of the elastomer composition of the present invention. In one preferred embodiment, the film of the present invention is a film made of the elastomer composition of the present invention, wherein (C) a photopolymerization initiator is acted upon irradiation with active energy rays, and (A) a copolymer elastomer of α-olefin and polyene is crosslinked. In one embodiment, the film of the present invention may be a multilayer film having one or more layers made of the elastomer composition of the present invention. In another preferred embodiment, the film of the present invention is a multilayer film having one or more layers made of the elastomer composition of the present invention, wherein the layer made of the elastomer composition of the present invention is a multilayer film in which (C) a photopolymerization initiator is acted upon irradiation with active energy rays, and (A) a copolymer elastomer of α-olefin and polyene is crosslinked.

[0081] The total light transmittance of the film of the present invention, as measured according to JIS K7136:2000, is preferably 70% or more, more preferably 75% or more, even more preferably 80% or more, even more preferably 85% or more, and most preferably 88% or more. A total light transmittance of 70% or more allows the film of the present invention to be suitably used in applications requiring transparency, such as base films for chipping films.

[0082] The loss tangent (tanδ) of the film of the present invention at a temperature of 140°C is preferably 0.70 or less, more preferably 0.60 or less, even more preferably 0.50 or less, and even more preferably 0.40 or less, from the viewpoint of heat resistance. Here, the loss tangent (tanδ) is the value of the loss tangent (tanδ) at a temperature of 140°C in the temperature-loss tangent curve obtained by measuring using a dynamic viscoelasticity measuring device, using a sample of 25 mm in length and 10 mm in width taken from the film, setting the sample so that the distance between the chucks is 5 mm, holding it in tensile mode, frequency of 1 Hz, and temperature of -80°C for 1 minute, and then raising the temperature to 250°C at a heating rate of 5°C / min. Although there is no intention to be bound by theory, the loss tangent (tanδ) at a temperature of 140°C is considered to be an indicator of the degree of crosslinking of the copolymer elastomer of (A) α-olefin and polyene in the film of the present invention (when the loss tangent (tanδ) at a temperature of 140°C is smaller, the degree of crosslinking is greater).

[0083] The thickness of the film of the present invention can be appropriately determined considering film-forming properties, application and required characteristics, and handling. When used as a base film for a chipping film, the thickness of the film of the present invention is usually 50 to 700 μm, preferably 100 to 500 μm, and more preferably 120 to 300 μm.

[0084] 4. Film manufacturing method: The method for producing the film of the present invention is not particularly limited. For example, a method for producing the film of the present invention can be obtained by first obtaining the elastomer composition of the present invention, then forming it into a film by a known method, and then irradiating it with active energy rays. In one preferred embodiment, the film of the present invention can be obtained by a production method comprising: (1) a step of obtaining the elastomer composition of the present invention; (2) a step of forming a film using a film-making apparatus with the elastomer composition obtained in step (1); and (3) a step of irradiating the film-like molded body obtained in step (2) with active energy rays.

[0085] Step (1) described above is a step to obtain the elastomer composition of the present invention. The elastomer composition of the present invention is described in "1. Elastomer Composition". The method for obtaining the elastomer composition of the present invention is described in "2. Method for Producing the Elastomer Composition".

[0086] Step (2) above is a step of forming a film using a film-forming apparatus with the elastomer composition obtained in step (1) above. The elastomer composition may be used in pellet form, or the lump, rod, or strand form of the elastomer composition discharged from the melt kneader may be sent directly to the film-forming apparatus and used.

[0087] The above-mentioned film-forming apparatus is not particularly limited, and any film-forming apparatus can be used. Since the elastomer composition of the present invention is a relatively high-viscosity composition, the above-mentioned film-forming apparatus may preferably be a T-die film-forming apparatus comprising an extruder, a T-die, and a winding device, or a calender roll rolling film-forming apparatus comprising a calender roll rolling machine and a winding device.

[0088] When using a T-die film-forming apparatus equipped with an extruder, a T-die, and a winding device as the above-mentioned film-forming apparatus, the T-die outlet resin temperature may be preferably 300°C or lower, more preferably 240°C or lower, and even more preferably 200°C or lower, from the viewpoint of suppressing the consumption of (C) photopolymerization initiator before irradiation with active energy rays. On the other hand, the T-die outlet resin temperature may be preferably 120°C or higher, more preferably 135°C or higher, and even more preferably 150°C or higher, from the viewpoint of melting and dispersing (C) photopolymerization initiator to ensure the action of the component, and from the viewpoint of the transparency of the resulting film.

[0089] When using a calender roll rolling film-forming apparatus equipped with a calender roll rolling machine and a winding device as the above-mentioned film-forming apparatus, the resin temperature of the film-like molded body sent from the calender roll rolling machine to the winding device may be preferably 300°C or lower, more preferably 240°C or lower, and even more preferably 200°C or lower, from the viewpoint of suppressing the consumption of (C) photopolymerization initiator before irradiation with active energy rays. On the other hand, the resin temperature may be preferably 120°C or higher, more preferably 135°C or higher, and even more preferably 150°C or higher, from the viewpoint of melting and dispersing the (C) photopolymerization initiator to reliably obtain the action of the component, and from the viewpoint of the transparency of the resulting film.

[0090] Step (3) above is a step of irradiating the film-like molded body obtained in step (2) above with active energy rays. In step (3), by irradiating with active energy rays, (C) the photopolymerization initiator acts and (A) the copolymer elastomer of α-olefin and polyene is crosslinked.

[0091] The cumulative irradiation dose of the above irradiation can be appropriately selected and determined from the viewpoint of sufficient crosslinking (obtaining sufficient heat resistance) and from the viewpoint of preventing discoloration (yellowing), taking into account the thickness of the film-like molded body obtained in step (2) above. The cumulative irradiation dose of the above irradiation depends on the thickness of the film-like molded body obtained in step (2) above, but from the viewpoint of sufficient crosslinking (obtaining sufficient heat resistance), it is usually 100 mJ / cm². 2 Preferably 300 mJ / cm² 2 More precisely, 500 mJ / cm 2 The above is acceptable. On the other hand, from the viewpoint of preventing discoloration (yellowing), the usual amount is 10,000 J / cm². 2 Preferably, 7000 mJ / cm² 2 More specifically, 4000 mJ / cm² 2 More preferably, 2000 mJ / cm² 2 The following is acceptable:

[0092] After step (3) above, an aging treatment may be performed. This can stabilize the properties of the film of the present invention.

[0093] 5. Goods: The articles of the present invention include the elastomer composition of the present invention. In one typical embodiment, the articles of the present invention include the film of the present invention. Examples of articles of the present invention include surface protection films, such as chipping films and other surface protection films for automobiles, and decorative films, such as dressing films, marking films, taillight seals and emblem seals and other decorative films for automobiles, as well as umbrellas, raincoats, bags and patches. [Examples]

[0094] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0095] Measurement method (i) Tensile test: In accordance with JIS K7127:1999, a tensile testing machine "Autograph AGS-1kNX (product name)" manufactured by Shimadzu Corporation was used. Samples punched from film were used to create test specimens of type 5 (Figure 2 in the above JIS standard), with the machine direction of the film oriented in the tensile direction. Tensile tests were performed at a tensile speed of 200 mm / min and a temperature of 23°C to obtain stress-strain curves. Next, from the obtained stress-strain curves, the tensile stress at which the sample fractured was calculated as tensile strength (unit: MPa), and the strain was calculated as tensile elongation (unit: %).

[0096] (b) Total light transmittance: In accordance with JIS K7136:2000, the total light transmittance (unit: %) of the film was measured using the NDH4000 turbidimeter (product name) manufactured by Nippon Denshoku Industries Co., Ltd. The glossy side (the side that was the mirror-finish roll side during film formation) was positioned towards the light source.

[0097] (h) Loss tangent (tanδ): Using a dynamic viscoelasticity measuring device, a sample taken from the film was used in a shape of 25 mm in length and 10 mm in width such that the machine direction of the film was the tensile direction. The sample was set so that the distance between the chucks was 5 mm, held for 1 minute at a tensile mode, a frequency of 1 Hz, and a temperature of -80°C, and then a temperature-loss tangent curve was obtained under the conditions of a temperature program in which the temperature was raised to 250°C at a rate of 5°C / min. Next, the value of the loss tangent at a temperature of 140°C was calculated from the obtained temperature-loss tangent curve.

[0098] (ii) Yellowness index: In accordance with JIS K7105:1981, the yellowness index of the film was measured using a colorimeter "SolidSpec-3700 (trade name)" manufactured by Shimadzu Corporation.

[0099] Raw materials used (A) Copolymer elastomer of α-olefin and polyene (A-1) Ethylene·propylene·ethylidene norbornene copolymer "Nordel 4725P (trade name)" of The Dow Chemical Company. Crystallization temperature 36°C (low crystallinity), Mooney viscosity (ML 1+4 125°C) 25, content of structural unit derived from ethylene 70% by mass, content of structural unit derived from ethylidene norbornene 4.9% by mass (A-2) Ethylene·propylene·ethylidene norbornene copolymer "Nordel 4820P (trade name)" of The Dow Chemical Company. Crystallization temperature 79°C (low crystallinity), Mooney viscosity (ML 1+4 125°C) 20, content of structural unit derived from ethylene 85% by mass, content of structural unit derived from ethylidene norbornene 4.9% by mass

[0100] (B) Polyolefin (B-1) Propylene·ethylene random copolymer "Novatec MG03BD (trade name)" of Japan Polypropylene Corporation, melt mass flow rate (230°C, 21.18 N) 30 g / 10 min, melting point 153°C, melting enthalpy 89 J / g. (B-2) Novatec MA1B (trade name), a propylene homopolymer from Nippon Polypropylene Co., Ltd., with a melt mass flow rate of 21 g / 10 min (230°C, 21.18 N), melting point 162°C, and enthalpy of fusion 104 J / g. (B-3) Evonik's polyolefin "VESTOPLAST508 (trade name)": Melt mass flow rate (230°C, 21.18N) was unmeasurable (significantly exceeding 100g / 10min), and the DSC melting curve did not show a clear melting peak (amorphous). (B-4) Nippon Polypropylene Co., Ltd.'s polypropylene "Wintec WFW4M (product name)", melt mass flow rate (230℃, 21.18N) 7.0g / 10min, melting point 135℃, enthalpy of fusion 76J / g. (B-5) Nippon Polypropylene Co., Ltd.'s polypropylene "Wintec WSX03A (product name)", melt mass flow rate (230℃, 21.18N) 25g / 10min, melting point 125℃, enthalpy of fusion 66J / g.

[0101] (C1) Hydrogen abstraction type photopolymerization initiator (C1-1)4-benzoyl-4'-methyldiphenyl sulfide. CAS number 83846-85-9, thermal decomposition onset temperature 200°C.

[0102] (C2) Intramolecular cleavage type photopolymerization initiator (C2-1) Omnirad 184 (trade name), an alkylphenone-based photoinitiator (1-hydroxycyclohexyl phenyl ketone) from IGM Resins.

[0103] Example 1-1 A mixture consisting of 100 parts by mass of component (A-1), 5.0 parts by mass of component (B-1), and 0.50 parts by mass of component (C1-1) was melt-kneaded at a temperature of 170°C to obtain an elastomer composition. Next, using this elastomer composition, a die "T150C" was connected to a Laboplast Mill "4C150" (product name) manufactured by Toyo Seiki Seisakusho Co., Ltd. Extrusion was performed according to the manuals for these devices, with cylinder set temperatures of 120°C / 180°C / 200°C in the order of C1 / C2 / C3, a die set temperature of 200°C, and a screw rotation speed of 80 rpm. The resin pressure (unit: MPa) was measured during extrusion. The results are shown in Table 1.

[0104] Examples 1-2~12 An elastomer composition was obtained in the same manner as in Example 1-1, except that the formulation was changed as shown in Table 1. The resin pressure (in MPa) was then measured in the same manner as in Example 1-1. The results are shown in Table 1.

[0105] [Table 1]

[0106] It was found that the elastomer composition of the present invention can be extruded at low resin pressure. Therefore, it was concluded that the moldability of the elastomer composition of the present invention has been greatly improved.

[0107] Example 2-1 A mixture consisting of 100 parts by mass of component (A-1), 2.0 parts by mass of component (B-1), and 0.5 parts by mass of component (C1-1) was melt-kneaded at a temperature of 170°C to obtain an elastomer composition. Next, an unirradiated film with a thickness of 150 μm was obtained using a T-die film-forming apparatus equipped with a 40 mm extruder, a T-die, and a winding device having a nipping mechanism between a mirror-finish metal roll and a matte rubber roll. Subsequently, the unirradiated film was irradiated using a high-pressure mercury lamp type ultraviolet irradiation device with an integrated light intensity of 730 mJ / cm². 2 The film was obtained after irradiation with ultraviolet light under the specified conditions. Tests (a) to (d) described above were performed. The results are shown in Table 2.

[0108] Examples 2-2~7 Except for changing the formulation as shown in Table 2, the irradiated film was obtained in the same manner as in Example 2-1. Tests (a) to (d) described above were performed. The results are shown in Table 2.

[0109] [Table 2]

[0110] Films made from the elastomer composition of the present invention were found to have excellent flexibility. Films made from preferred elastomer compositions of the present invention were also found to have good transparency, heat resistance, and color tone. However, the film of Example 2-6 had greater variation in thickness compared to the films of the other examples. This was considered to be because the kneading conditions were too weak to adequately mix components (A-1) and (B-3).

[0111] All disclosures of Japanese Patent Application No. 2023-085844 are incorporated herein by reference. In the event of any conflict between the contents of this specification and the disclosures of Japanese Patent Application No. 2023-085844, the contents of this specification shall prevail.

Claims

1. (A) Copolymer elastomer of α-olefin and polyene, (B) Polyolefins (excluding those corresponding to the copolymer elastomer of component (A) α-olefin and polyene), and (C) Photopolymerization initiator The above components include, where the amount of component (C) photopolymerization initiator is 0.01 to 30 parts by mass per 100 parts by mass of component (A) copolymer elastomer of α-olefin and polyene. Elastomer composition.

2. The elastomer composition according to claim 1, wherein the above component (A) copolymer elastomer of α-olefin and polyene comprises a copolymer elastomer of α-olefin and non-conjugated polyene.

3. The elastomer composition according to claim 1, wherein the above component (A) copolymer elastomer of α-olefin and polyene comprises a copolymer elastomer of ethylene, propylene, and one or more dienes selected from the group consisting of 5-ethylidene-2-norbornene, tricyclo[4.3.0.12,5]deca-3,7-diene, and 1,4-hexadiene.

4. The elastomer composition according to claim 2, wherein the above component (C) photopolymerization initiator includes a hydrogen abstraction type photopolymerization initiator.

5. The elastomer composition according to claim 4, which does not contain an intramolecular cleavage type photopolymerization initiator.

6. The elastomer composition according to claim 1, wherein the amount of component (B) polyolefin is 0.1 to 100 parts by mass per 100 parts by mass of the copolymer elastomer of component (A) α-olefin and polyene.

7. The elastomer composition according to claim 1, wherein the above component (B) polyolefin comprises polypropylene.

8. A film comprising the elastomer composition according to any one of claims 1 to 7.

9. An article comprising the film described in claim 8.

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