Elastic sheet and laminate

Abstract

An elastic sheet formed from a resin composition containing a copolymer (a), a hydrocarbon softener (b), and a styrene-containing oligomer (c), with respect to 100 parts by mass of the copolymer (a), 50-200 parts by mass of the hydrocarbon softener (b), and 5-20 parts by mass of the styrene-containing oligomer (c), the copolymer (a) is a block copolymer containing a polymer block A mainly composed of a vinyl aromatic compound and a polymer block B mainly composed of a conjugated diene compound, or a hydrogenated product thereof, and the stretchable sheet has a thickness of 200 [mu] m or less.

Description

Technical Field

[0001] This invention relates to stretchable sheets and laminates. Background Technology

[0002] In clothing, daily necessities, hygiene products, and other products, there are parts that require elasticity. As components used in these parts, various elastic components, including thermoplastic synthetic resins such as polyurethane resins, polystyrene resins, and vinyl resins, as well as natural resins, have been studied in the past.

[0003] For example, Patent Document 1 discloses a stretchable material containing specific block copolymers and with adjusted physical properties such as residual strain, as a stretchable material with elasticity and flexibility. Patent Document 2 discloses a stretchable member formed from a thermoplastic polymer composition containing two specific block copolymers. Patent Document 3 discloses a porous sheet containing specific block copolymers and a hydrocarbon softener.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2002-363376

[0007] Patent Document 2: Japanese Patent Application Publication No. 2006-89546

[0008] Patent Document 3: Japanese Patent No. 6931363 Specification Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] According to the research of the inventors, the stretchable sheets used in the past sometimes become irreversible and prone to loosening with repeated use. Furthermore, in the case of stretchable sheets made of polyurethane resins used in the past, excessive tightness can sometimes negatively impact the comfort of wearing the clothing, for example.

[0011] Therefore, the object of the present invention is to provide a stretchable sheet that has a small fastening of the stretchable part and does not loosen during repeated use.

[0012] Problem Solving Methods

[0013] To solve the above-mentioned problems, the inventors conducted in-depth research on the materials and physical properties of the stretch sheet, and discovered that the above-mentioned problems can be solved by forming a stretch sheet with a specific thickness from a specific resin composition, thereby completing the present invention. That is, the present invention includes the following embodiments.

[0014] [1] A stretchable sheet formed from a resin composition comprising a copolymer (a), a hydrocarbon softener (b), and a styrene-containing oligomer (c), wherein the hydrocarbon softener (b) comprises 50 to 200 parts by weight relative to 100 parts by weight of the copolymer (a), and the styrene-containing oligomer (c) comprises 5 to 20 parts by weight.

[0015] The copolymer (a) is a block copolymer or its hydrogenation comprising a polymer block A mainly composed of a vinyl aromatic compound and a polymer block B mainly composed of a conjugated diene compound.

[0016] The thickness of the stretchable sheet is less than 200 μm.

[0017] [2] The stretchable sheet according to [1] has a tension of less than 1.5 N / 5 mm when it is 100% elongated.

[0018] [3] The stretchable sheet according to [1] or [2], wherein,

[0019] Based on the total amount of the resin composition, the total amount of copolymer (a), hydrocarbon softener (b), and styrene-containing oligomer (c) is 85% by mass or more.

[0020] [4] The stretchable sheet according to any one of [1] to [3], wherein,

[0021] The flow start temperature of the resin composition is below 200°C.

[0022] [5] The stretchable sheet according to any one of [1] to [4] is capable of being heat-fused at a temperature of 170°C or below.

[0023] [6] The stretchable sheet according to any one of [1] to [5], wherein,

[0024] The weight-average molecular weight of copolymer (a) is 50,000 to 140,000.

[0025] [7] The stretchable sheet according to any one of [1] to [6], wherein,

[0026] The copolymer (a) comprises constituent units derived from styrene monomers, and the amount of the constituent units derived from styrene monomers is 15% by mass or more based on the total amount of all constituent units of the copolymer (a).

[0027] [8] The stretchable sheet according to any one of [1] to [7], wherein,

[0028] The weight-average molecular weight of styrene-containing oligomers (c) is 1000~6000.

[0029] [9] The stretchable sheet according to any one of [1] to [8], wherein,

[0030] The resin composition further comprises 1 to 50 parts by weight of a polyolefin resin (d) relative to 100 parts by weight of copolymer (a).

[0031]

[10] According to the stretchable sheet described in [9], wherein,

[0032] The melt flow rate of polyolefin resin (d) is 0.1~100 g / 10 min.

[0033]

[11] The stretchable sheet according to [9] or

[10] , wherein,

[0034] Polyolefin resin (d) is ethylene with at least one C3-C 12 Copolymers of α-olefins.

[0035]

[12] The stretchable sheet according to any one of [1] to

[11] , wherein,

[0036] The amount of acrylic block copolymer in the resin composition is more than 0 parts by mass and less than 20 parts by mass relative to 100 parts by mass of copolymer (a).

[0037]

[13] The stretchable sheet according to any one of [1] to

[12] , wherein,

[0038] The length recovery rate of the stretch sheet after repeated 100% elongation at room temperature was over 99.0%.

[0039]

[14] The stretchable sheet according to any one of [1] to

[13] , wherein,

[0040] The length recovery rate of the stretch sheet after being held at 50% elongation for 2 hours at 35°C was over 87.0%.

[0041]

[15] The stretchable sheet according to any one of [1] to

[14] is a stretchable strip.

[0042]

[16] A laminated body having at least:

[0043] Expansive substrate layer (1), and

[0044] The resin layer (2) adjacent to the elastic substrate layer,

[0045] The resin layer (2) is a layer formed from any one of the stretchable sheets described in [1] to

[15] .

[0046]

[17] According to the laminated body described in

[16] , wherein,

[0047] The elastic substrate layer (1) and the resin layer (2) are adjacent to each other on both sides.

[0048] The effects of the invention

[0049] According to the present invention, a stretchable sheet with a small fastening of the stretchable portion can be provided, which does not loosen during repeated use. Detailed Implementation

[0050] The embodiments of the present invention will now be described in detail. It should be noted that the scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without departing from the spirit of the invention.

[0051] The stretchable sheet of the present invention is formed from a resin composition comprising a copolymer (a), a hydrocarbon softener (b), and a styrene-containing oligomer (c), wherein the hydrocarbon softener (b) comprises 50 to 200 parts by weight relative to 100 parts by weight of the copolymer (a), and the styrene-containing oligomer (c) comprises 5 to 20 parts by weight.

[0052] The copolymer (a) is a block copolymer or its hydrogenation comprising a polymer block A mainly composed of a vinyl aromatic compound and a polymer block B mainly composed of a conjugated diene compound.

[0053] The thickness of the stretchable sheet is less than 200 μm.

[0054] [Resin Composition]

[0055] (Copolymer(a))

[0056] The resin composition forming the stretchable sheet of the present invention comprises a copolymer (a), which is a block copolymer or a hydrogenation thereof comprising a polymer block A mainly composed of a vinyl aromatic compound and a polymer block B mainly composed of a conjugated diene compound.

[0057] Polymer block A is a polymer block primarily composed of vinyl aromatic compounds. Examples of vinyl aromatic compounds include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-tert-butylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, vinylanthracene, N,N-diethyl-4-aminoethylstyrene, vinylpyridine, 4-methoxystyrene, monochlorostyrene, dichlorostyrene, and divinylbenzene. These vinyl aromatic compounds can be used alone or in combination. From the viewpoint of reducing stress and improving elasticity at 100% elongation, styrene, α-methylstyrene, and 4-methylstyrene are preferred, with styrene being more preferred.

[0058] In this specification, "mainly composed of vinyl aromatic compounds" means that, based on the total amount of all constituent units of polymer block A, the amount of constituent units from vinyl aromatic compounds in polymer block A is more than 50% by mass. Based on the total amount of all constituent units of polymer block A, the amount of constituent units from vinyl aromatic compounds is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, further more preferably 90% by mass or more, particularly preferably 95% by mass or more, and particularly more preferably 100% by mass.

[0059] Furthermore, from the viewpoint of reducing stress and improving elasticity at 100% elongation, the amount of constituent units from vinyl aromatic compounds is preferably 5 to 75% by mass, more preferably 10 to 50% by mass, based on the total amount of all constituent units of the copolymer (a).

[0060] Polymer block A may contain constituent units from monomers other than vinyl aromatic compounds, such as constituent units from monomers constituting polymer block B described later. In this case, the content of structural units from monomers other than vinyl aromatic compounds in polymer block A is less than 50% by mass, preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less.

[0061] Polymer block B is a polymer block primarily composed of a conjugated diene compound. Examples of conjugated diene compounds include butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenylbutadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, 1,3,7-octtriene, myrcene, farnesene, and chlorobutene. These conjugated diene compounds can be used alone or in combination. From the viewpoint of reducing stress and improving elasticity at 100% elongation, the conjugated diene compound is preferably selected from at least one of butadiene, isoprene, and farnesene, and more preferably from at least one of butadiene and isoprene.

[0062] In this specification, "mainly composed of conjugated diene compounds" means that, based on the total amount of all constituent units of polymer block B, the amount of constituent units from conjugated diene compounds in polymer block B is more than 50% by mass. Based on the total amount of all constituent units of polymer block B, the amount of constituent units from conjugated diene compounds is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, further more preferably 90% by mass or more, particularly preferably 95% by mass or more, and particularly more preferably 100% by mass. It should be noted that when the copolymer (a) is a polymer that has been at least partially hydrogenated, the constituent units from conjugated diene compounds also include hydrogenated constituent units from conjugated diene compounds.

[0063] Furthermore, from the viewpoint of reducing stress and improving elasticity at 100% elongation, the amount of constituent units from the conjugated diene compound is preferably 25 to 95% by mass, more preferably 50 to 90% by mass, based on the total amount of all constituent units of the copolymer (a).

[0064] Polymer block B may contain constituent units from monomers other than the conjugated diene compound, such as constituent units from monomers constituting polymer block A or other monomers. In this case, the content of structural units from monomers other than the conjugated diene compound in polymer block B is less than 50% by mass, preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less.

[0065] The copolymer (a) is a block copolymer comprising polymer block A and polymer block B, or a hydrogenation thereof, preferably a hydrogenation of a block copolymer comprising polymer block A and polymer block B. When copolymer (a) is a hydrogenation, preferably 50 mol% or more of the carbon-carbon double bond of the polymer block B from the conjugated diene compound is hydrogenated, more preferably 75 mol% or more, and even more preferably 95 mol% or more.

[0066] The copolymer (a) only needs to contain at least one polymer block A and at least one polymer block B. From the viewpoint of heat resistance, mechanical properties, and stretchability of the stretchable sheet, it is preferable to contain at least two polymer blocks A and at least one polymer block B. The bonding mode between polymer blocks A and B can be linear, branched, or any combination thereof. When polymer block A is represented by A and polymer block B by B, examples include: a triblock structure represented by ABA, and a structure represented by (AB). n (AB) n -A (where n represents an integer greater than 2) represents multi-block copolymers, etc., among which, copolymers with a triblock structure represented by ABA are preferred from the viewpoint of heat resistance, mechanical properties, stretchability, and processability of the stretch sheet. When copolymer (a) contains two or more polymer blocks A, each polymer block A may be the same or different from the others. The same applies to polymer blocks B.

[0067] From the viewpoints of film-forming properties, heat resistance, mechanical properties, stretchability, and processability of the sheet, the weight-average molecular weight of copolymer (a) is preferably 50,000 or more, more preferably 52,000 or more. From the viewpoints of stretchability, such as the recovery after repeated stretching operations and / or maintaining a stretched state for a certain period of time, and reducing the thickness of the sheet, it is preferably 140,000 or less, more preferably 120,000 or less, and even more preferably 100,000 or less. The weight-average molecular weight of copolymer (a) is preferably 50,000 to 140,000, more preferably 50,000 to 120,000, and even more preferably 52,000 to 100,000. It should be noted that the weight-average molecular weight mentioned in this specification refers to the weight-average molecular weight converted from standard polystyrene, determined by gel permeation chromatography (GPC) under the conditions shown below, for example.

[0068] Measurement conditions:

[0069] GPC; LC Solution (manufactured by SHIMADZU)

[0070] Detector: Differential refractometer RID-10A (manufactured by SHIMADZU)

[0071] Column: Two TSKgelG4000Hxl tubes connected in series (made by TOSOH)

[0072] Guard column: TSKguardcolumnHxl-L (manufactured by TOSOH)

[0073] Solvent: Tetrahydrofuran

[0074] Temperature: 40℃

[0075] Flow rate: 1 ml / min

[0076] Concentration: 2mg / ml

[0077] In a preferred embodiment of the present invention, the copolymer (a) preferably comprises constituent units derived from styrene monomers. In this embodiment, from the viewpoint of improving elasticity, based on the total amount of copolymer (a), the content of styrene monomers in copolymer (a) is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more. Furthermore, from the viewpoint of softness, it is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less. From the above viewpoints, the content of styrene monomers in copolymer (a) is preferably 15-50% by mass, more preferably 20-40% by mass, and even more preferably 25-35% by mass. The content of constituent units derived from styrene monomers in copolymer (a) (also referred to as styrene content) can be calculated based on the monomer ratio during the manufacture of copolymer (a), or it can be determined by… 1 Calculations such as H-NMR analysis.

[0078] From the viewpoint of reducing stress at 100% elongation, the hardness of copolymer (a) is preferably 20A to 50A, more preferably 25A to 45A, and even more preferably 30A to 40A. The hardness can be measured using a type A hardness tester based on the JIS K 6253-1997 hardness tester standard.

[0079] From the viewpoint of improving elasticity, based on the total amount of the resin composition, the content of copolymer (a) contained in the resin composition is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more. From the viewpoint of processability and treatability, it is preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 55% by mass or less. From the above viewpoints, the content of copolymer (a) contained in the resin composition is preferably 20 to 70% by mass, more preferably 25 to 60% by mass, and even more preferably 30 to 55% by mass.

[0080] (Hydrocarbon softener (b))

[0081] In addition to the copolymer (a), the resin composition forming the stretchable sheet of the present invention further comprises a hydrocarbon softener (b). Examples of hydrocarbon softeners (b) include paraffinic oils, cycloalkane oils, aromatic oils, liquid paraffin, etc., with paraffinic oils and cycloalkane oils being preferred. These can be used alone or in combination of two or more. The hydrocarbon softener (b) is preferably a non-aromatic hydrocarbon softener. It should be noted that a non-aromatic hydrocarbon softener refers to a softener in which the proportion of carbon atoms in the aromatic ring to the total number of carbon atoms in the molecule is preferably less than 35%, more preferably less than 30%, and even more preferably less than 25%.

[0082] The content of hydrocarbon softener (b) is 50 to 200 parts by mass relative to 100 parts by mass of copolymer (a) contained in the resin composition. When the content of hydrocarbon softener (b) is less than 50 parts by mass, the elasticity of the resin composition is too high, and it is sometimes difficult to obtain stretchability. Moreover, sufficient film-forming properties of the resin composition are sometimes not obtained. On the other hand, when it exceeds 200 parts by mass, mechanical strength is sometimes not obtained. From the viewpoint of reducing stress at 100% elongation, the content of hydrocarbon softener (b) is preferably 55 to 170 parts by mass relative to 100 parts by mass of copolymer (a) contained in the resin composition, more preferably 60 to 150 parts by mass, and even more preferably 70 to 120 parts by mass.

[0083] The kinematic viscosity of the hydrocarbon softener (b) was determined at 40°C according to JIS K 2283:2000, and was preferably 10~500 mm. 2 / s, more preferably 50~450mm 2 / s, further preferably 100~400mm 2 / s.

[0084] (Contains styrene oligomers (c))

[0085] In addition to the copolymer (a) and the hydrocarbon softener (b), the resin composition forming the stretchable sheet of the present invention further comprises a styrene-containing oligomer (c). Here, in this specification, a styrene-containing oligomer refers to an oligomer having constituent units derived from styrene monomers and not belonging to the copolymer (a) described above. Examples of styrene-containing oligomers (c) include: polystyrene, polyα-methylstyrene, poly4-methylstyrene, styrene / α-methylstyrene copolymer, styrene / 4-methylstyrene copolymer, α-methylstyrene / 4-methylstyrene copolymer, and styrene / α-methylstyrene / 4-methylstyrene copolymer. It should be noted that the styrene-containing oligomer (c) may be used alone or in combination of two or more.

[0086] As a styrene-containing oligomer (c), commercially available products can be used. Examples of commercially available products that can be used as styrene-containing oligomers (c) include: Piccolastic A5 (polystyrene, softening point 5°C, Mw350), Piccolastic A-75 (polystyrene, softening point 74°C, Mw1300), Piccotex 75 (α-methylstyrene / 4-methylstyrene copolymer, softening point 75°C, Mw1100), Piccotex LC (α-methylstyrene / 4-methylstyrene copolymer, softening point 91°C, Mw1350), Kristalex 3070 (styrene / α-methylstyrene copolymer, softening point 70°C, Mw950), Kristalex 3085 (styrene / α-methylstyrene copolymer, softening point 85°C, Mw1150), Kristalex 3100 (styrene / α-methylstyrene copolymer, softening point 100°C, Mw1500), and Kristalex... Aromatic polymers manufactured by EASTMAN, including 5140 (styrene / α-methylstyrene copolymer, softening point 139℃, Mw 4900), Endex 155 (poly-α-methylstyrene, softening point 153℃, Mw 6900), and Endex 160 (poly-α-methylstyrene, softening point 158℃, Mw 9200); Haimer ST-95 (polystyrene, softening point 95℃, Mw 4000; manufactured by Sanyo Chemical Industry); and YS Resin SX-100 (polystyrene, softening point 100℃, Mw 2500; manufactured by Yasuhara). FMR-0150 (styrene / aromatic hydrocarbon copolymer, softening point 145℃, Mw2040; manufactured by Mitsui Chemicals Co., Ltd.), FTR-6100 (styrene / aliphatic hydrocarbon copolymer, softening point 95℃, Mw1210; manufactured by Mitsui Chemicals Co., Ltd.), FTR-6110 (styrene / aliphatic hydrocarbon copolymer, softening point 110℃, Mw1570; manufactured by Mitsui Chemicals Co., Ltd.), FTR-6125 (styrene / aliphatic hydrocarbon copolymer, softening point 125℃, Mw1950; manufactured by Mitsui Chemicals Co., Ltd.) FTR-7100 (styrene / α-methylstyrene / aliphatic hydrocarbon copolymer, softening point 100℃, Mw1440; manufactured by Mitsui Chemicals Co., Ltd.), FTR-0100 (poly-α-methylstyrene, softening point 100℃, Mw1960; manufactured by Mitsui Chemicals Co., Ltd.), FTR-2120 (styrene / α-methylstyrene copolymer, softening point 120℃, Mw2630; manufactured by Mitsui Chemicals Co., Ltd.), FTR-2140 (styrene / α-methylstyrene copolymer, softening point 137℃, Mw3230; manufactured by Mitsui Chemicals Co., Ltd.), etc.

[0087] The content of styrene-containing oligomer (c) is 5 to 20 parts by mass relative to 100 parts by mass of copolymer (a) contained in the resin composition. When the content of styrene-containing oligomer (c) is less than 5 parts by mass, the styrene phase of copolymer (a) is not reinforced and cannot withstand long-term elongation stress. On the other hand, when it exceeds 20 parts by mass, sufficient elasticity of the stretchable sheet is sometimes not obtained. From the viewpoint of preventing relaxation, the content of styrene-containing oligomer (c) is preferably 5 to 18 parts by mass relative to 100 parts by mass of copolymer (a) contained in the resin composition, more preferably 6 to 17 parts by mass, and even more preferably 7 to 15 parts by mass.

[0088] From the viewpoint of the reinforcing effect of the styrene phase in copolymer (a), the weight-average molecular weight of the styrene-containing oligomer (c) is preferably 300 or more, more preferably 700 or more, further preferably 1000 or more, more preferably 1500 or more, and especially preferably 2000 or more. From the viewpoint of compatibility with the styrene phase of copolymer (a), it is preferably 10000 or less, more preferably 8000 or less, more preferably 6000 or less, more preferably 5500 or less, and especially preferably 5000 or less. Therefore, the weight-average molecular weight of the styrene-containing oligomer (c) is preferably 300 to 10000, more preferably 700 to 8000, more preferably 1000 to 6000, more preferably 1500 to 5500, and especially preferably 2000 to 5000. It should be noted that the weight-average molecular weight of the styrene-containing oligomer (c) can be determined by gel permeation chromatography using standard polystyrene. The mechanism of the styrene phase in the styrene-containing oligomer-reinforced copolymer (a) is not clear, but it can be assumed that the styrene-containing oligomers of a certain molecular weight are compatible with the styrene phase of the copolymer (a), thus increasing the aggregation force of the styrene phase and achieving a reinforcing effect.

[0089] From the viewpoint of compatibility with the styrene phase of copolymer (a), based on the total amount of styrene-containing oligomer (c), the content of constituent units derived from styrene monomers in the styrene-containing oligomer (c) is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more. From the viewpoint of recovery after prolonged application of tensile stress, it is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. Therefore, from the above viewpoints, the content of constituent units derived from styrene monomers in the styrene-containing oligomer (c) is preferably 40 to 90% by mass, more preferably 50 to 80% by mass, and even more preferably 60 to 70% by mass.

[0090] The softening point of the styrene-containing oligomer (c) is not particularly limited, but from the viewpoint of processability, it is preferably 110°C or higher, more preferably 120°C or higher, and even more preferably 130°C or higher.

[0091] The resin composition forming the stretchable sheet of the present invention comprises at least the above-mentioned copolymer (a), hydrocarbon softener (b), and styrene-containing oligomer (c). From the viewpoint of improving stretchability, the total amount of these components is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and can be 100% by mass or less.

[0092] (Other ingredients)

[0093] In addition to the copolymer (a), hydrocarbon softener (b), and styrene-containing oligomer (c) mentioned above, the resin composition forming the stretchable sheet of the present invention may also contain other components. Examples of other components include: polyolefin resins (d), fillers (e), antioxidants (f), other resins, lubricants, light stabilizers, processing aids, pigments, colorants such as pigments, flame retardants, antistatic agents, matting agents, silicone oils, anti-blocking agents, ultraviolet absorbers, release agents, foaming agents, antibacterial agents, antifungal agents, fragrances, etc.

[0094] Polyolefin resin (d) can be any resin formed by polymerizing olefin monomers, and there is no particular limitation. From the viewpoint of strength, molding processability, chemical resistance, heat resistance, etc., propylene polymers, ethylene polymers and their mixtures are preferred.

[0095] Examples of propylene polymers include homopolymer polypropylene and copolymers of propylene with other α-olefins (e.g., random copolymers, block copolymers). Stereoregularity is not particularly limited and can be isotactic polypropylene, syndiotactic polypropylene, atactic polypropylene, etc. Copolymers of other α-olefins with propylene (e.g., random copolymers and block copolymers) are preferred. Examples of other α-olefins include ethylene and α-olefins with 4 to 20 carbon atoms, such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, etc. The other α-olefin can be one type or a combination of two or more.

[0096] Examples of ethylene-based polymers include: ethylene homopolymers such as low-density polyethylene (LDPE), medium-density polyethylene, and high-density polyethylene (HDPE); and copolymers of ethylene with other α-olefins (e.g., random copolymers and block copolymers). Examples of other α-olefins include α-olefins with 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Other α-olefins can be one type or a combination of two or more. Specific examples include: ethylene / 1-butene copolymers, ethylene / 1-hexene copolymers, ethylene / 1-heptene copolymers, ethylene / octene copolymers, ethylene / 4-methyl-1-pentene copolymers, ethylene / 1-nonene copolymers, and ethylene / 1-decene copolymers, etc., which are ethylene / α-olefin copolymers.

[0097] In addition, to improve the compatibility between the copolymer (a) and the polyolefin resin (d), an olefin resin containing active groups can be used, which is obtained by copolymerizing (random copolymerization, graft copolymerization) a monomer having active groups such as hydroxyl, carbonyl, amide and / or ester groups with the polyolefin resin (d).

[0098] From the viewpoint of film-forming properties, the polyolefin resin (d) is preferably an ethylene polymer, more preferably ethylene with at least one C3-C polymer. 12 A copolymer of α-olefins, more preferably a copolymer of ethylene and at least one C3-C6 α-olefin.

[0099] When the resin composition contains a polyolefin resin (d), its content relative to 100 parts by weight of copolymer (a) is preferably 1 to 50 parts by weight, more preferably 2 to 40 parts by weight, even more preferably 3 to 30 parts by weight, and even more preferably 4 to 20 parts by weight. When the content of polyolefin resin (d) is within the above range, both film-forming properties and stretchability can be achieved, and therefore it is preferred.

[0100] From the viewpoint of film-forming properties when using the resin composition to mold stretchable sheets, the melt flow rate of the polyolefin resin (d) is preferably 0.1 to 100 g / 10 min, more preferably 1 to 80 g / 10 min, and even more preferably 5 to 50 g / 10 min. The melt flow rate can be measured according to JIS K7210-1:2014 (230°C, 2.16 kg load).

[0101] From the viewpoint of fabric adhesion, the melting point of the polyolefin resin (d) is preferably 100~150℃, more preferably 110~140℃, and even more preferably 120~130℃. The melting point can be determined by DSC.

[0102] As filler (e), examples include organic fillers and inorganic fillers. Examples of organic or inorganic fillers include: clay, diatomaceous earth, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxides, mica, graphite, aluminum hydroxide, and other flaky inorganic fillers. Additionally, as organic or inorganic fillers, various metal powders, wood chips, glass powders, ceramic powders, granular or powdered polymers, and other granular or powdered solid fillers, as well as various natural or artificial short or long fibers (e.g., straw, wool, glass fiber, metal fiber, and various other polymer fibers), can be included. From the viewpoint of processability (reduced viscosity), based on the total amount of the resin composition, the content of filler (e) is preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and even more preferably 0 to 3% by mass. In one embodiment of the present invention, the content of filler (e) in the resin composition is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and even more preferably the resin composition does not contain filler (e).

[0103] Examples of antioxidants (f) include hindered phenolic, phosphorus, lactone, and hydroxyl antioxidants. Among these, hindered phenolic antioxidants are preferred. When antioxidant (f) is present, its content is preferably within the range that does not cause coloring when the resin composition is melt-blended, and is preferably 0.1 to 5 parts by weight relative to 100 parts by weight of copolymer (a).

[0104] Examples of other resins include tackifying resins. Examples of tackifying resins include rosin resins, terpene phenolic resins, terpene resins, aromatic hydrocarbons, modified terpene resins, aliphatic petroleum resins, alicyclic petroleum resins, aromatic petroleum resins, coumarone-indene resins, phenolic resins, xylene resins, etc. From the viewpoint of film-forming properties and processability when manufacturing stretchable sheets, the softening point of the tackifying resin is preferably 85~160°C, more preferably 100~150°C, and even more preferably 105~145°C.

[0105] When the above-mentioned tackifying resin is contained, its content is preferably within a range that does not impair the mechanical properties of the resin composition, preferably 100 parts by weight or less, more preferably 70 parts by weight or less, further preferably 30 parts by weight or less, and particularly preferably 10 parts by weight or less, relative to 100 parts by weight of copolymer (a).

[0106] Other examples of resins include acrylic block copolymers. The amount of acrylic block copolymer in the resin composition of the present invention is preferably 0 parts by mass or more and less than 20 parts by mass relative to 100 parts by mass of copolymer (a), more preferably 0 parts by mass or more and 15 parts by mass or less, even more preferably 0 parts by mass or more and 10 parts by mass or less, and even more preferably 0 parts by mass or more and 5 parts by mass or less.

[0107] From the viewpoint of film-forming properties and processability when manufacturing the stretchable sheet, the flow start temperature of the resin composition forming the stretchable sheet of the present invention is preferably below 200°C, more preferably below 190°C, further preferably below 180°C, even more preferably below 170°C, particularly preferably below 160°C, even more preferably below 150°C, and especially preferably below 140°C. From the viewpoint of heat resistance, it is preferably above 110°C, more preferably above 120°C, and even more preferably above 130°C. Therefore, the flow start temperature of this resin composition is preferably 110~200°C, more preferably 110~190°C, even more preferably 110~180°C, even more preferably 120~170°C, especially preferably 120~160°C, even more preferably 130~150°C, and especially preferably 130~140°C. The flow start temperature of the resin composition can be measured using a flow tester, specifically, it can be measured using the method described in the examples.

[0108] From the viewpoint of film-forming properties and processability when manufacturing stretchable sheets, the melt flow rate of the resin composition forming the stretchable sheets of the present invention is preferably 5 to 100 g / 10 min, more preferably 10 to 90 g / 10 min, and even more preferably 30 to 80 g / 10 min. The melt flow rate can be measured according to JIS K7210-1:2014 (190°C, 2.16 kg load).

[0109] The stretchable sheet of the present invention is a thin sheet with a thickness of 200 μm or less. From the viewpoint of manufacturing such a thin sheet, the film-forming properties of the resin composition are required to be sufficiently high. From the viewpoint of improving film-forming properties, the extensibility of the resin composition is important. The winding speed at break, measured using Capillograph at a piston extrusion speed of 10 mm / min, a die orifice diameter of 1.0 mm, and a temperature of 170°C, is preferably 35 m / min or more, more preferably 40 m / min or more, and even more preferably 50 m / min or more. The details of the method for measuring the winding speed are as described in the examples.

[0110] The method for manufacturing the resin composition forming the stretchable sheet of the present invention is not particularly limited as long as it can uniformly mix the copolymer (a), hydrocarbon softener (b), styrene-containing oligomer (c), and other components such as polyolefin resin (d), filler (e), and antioxidant (f) added as needed. Examples include methods such as mixing solutions obtained by dissolving these components in a solvent and drying them as needed, and methods such as melt-blending these components. From the viewpoint of improving the dispersibility of the constituent components, melt-blending is preferred. Melt-blending can be carried out using melt-blending equipment such as short-screw extruders, twin-screw extruders, kneaders, batch mixers, roller mills, and Banbury mixers. It is preferable to obtain the resin composition forming the stretchable sheet of the present invention by melt-blending at a temperature of 170 to 270°C and a screw speed of 50 to 500 rpm.

[0111] [Stretchable film]

[0112] The stretchable sheet of the present invention is a stretchable sheet formed from the above-described resin composition. The thickness of the stretchable sheet is 200 μm or less.

[0113] The thickness of the stretch sheet of the present invention is 200 μm or less. Since the stretch sheet of the present invention is a thin sheet of 200 μm or less, it is easy to laminate onto a substrate for use, and it can balance reduced tightness and stretchability. Furthermore, since the stretch sheet is formed from the resin composition described above, it is possible to manufacture a very thin sheet of 200 μm or less. The thickness of the stretch sheet can be measured using, for example, a thickness gauge. The thickness of the stretch sheet of the present invention is only required to be 200 μm or less, and is not particularly limited. It can be appropriately adjusted according to the desired thickness. From the viewpoint of balancing stress reduction at 100% elongation and fabric adhesion, 50 to 200 μm is preferred, more preferably 60 to 170 μm, and even more preferably 70 to 150 μm.

[0114] The tension at 100% elongation of the stretchable sheet is preferably 1.5 N / 5 mm or less. When the tension at 100% elongation is 1.5 N / 5 mm or less, the tightness of the stretchable portion is low; therefore, when the stretchable sheet is used in, for example, clothing, it is considered less likely to cause discomfort to the wearer. From the viewpoint of balancing reduced tightness and stretchability, the tension at 100% elongation of the stretchable sheet of the present invention is more preferably 0.3 N / 5 mm or more and 1.5 N / 5 mm or less, further preferably 0.4 N / 5 mm or more and 1.2 N / 5 mm or less, and even more preferably 0.5 N / 5 mm or more and 1.0 N / 5 mm or less.

[0115] The tension at 100% elongation of the stretchable sheet is determined by cutting the stretchable sheet into 5mm wide samples as test specimens, drawing markings at given intervals (e.g., 20mm) on the center of the test specimen, and stretching the sheet to twice the interval between the markings (until 100% elongation). This tension can be measured using, for example, the method described in the embodiments. It should be noted that if the width of the stretchable sheet is less than 5mm, the result measured using this sheet can be converted to a value with a 5mm width and used as the tension at 100% elongation of the stretchable sheet.

[0116] The 100% elongation stress of the stretchable sheet is calculated by dividing the 100% elongation tension measured as described above by the cross-sectional area of ​​the test specimen, which is the 100% elongation tension per unit cross-sectional area. From the viewpoint of reduced tightness, the 100% elongation stress of the stretchable sheet is preferably 0.33 to 0.76 MPa, more preferably 0.35 to 0.7 MPa, and even more preferably 0.40 to 0.65 MPa.

[0117] From the viewpoint of improving elasticity and easily suppressing relaxation during repeated use, the length recovery rate (hereinafter also referred to as "recovery rate A") of the elastic sheet of the present invention after repeated 100% elongation three times at room temperature is preferably 99.0% or higher. In the determination of recovery rate A, a sheet cut into pieces with a width of 5 mm and a length of 80 mm is used as the test sample, and the distance between the marks on the sheet before repeated 100% elongation three times at room temperature is set as L. α The distance between the markings of the stretchable sheet after three cycles of 100% elongation is defined as L. β The following formula can be used to calculate it.

[0118] Response rate A (%) = (1 - (L) β -L α ) / L α )×100

[0119] The response rate A is more preferably 99.0% or higher, more preferably 99.5% or higher, and even more preferably 99.9% or higher.

[0120] From the viewpoint of improving elasticity and easily suppressing relaxation during repeated use, the length recovery rate (hereinafter also referred to as "recovery rate B") of the elastic sheet of the present invention after being held at 35°C for 2 hours in a state of 50% elongation is preferably 84% or more. In the determination of recovery rate B, a sheet cut into pieces with a width of 5 mm and a length of 80 mm is used as the test sample. The distance between the marks on the sheet before being held at 35°C for 2 hours in a state of 50% elongation is set as L0, and the distance between the marks on the elastic sheet after being held is set as L1. The result is calculated using the following formula.

[0121] Response rate B (%) = (1 - (L1 - L0) / L0) × 100

[0122] The response rate B is more preferably 85% or higher, even more preferably 87% or higher, and even more preferably 89% or higher.

[0123] The stretchable sheet of the present invention is generally a sheet capable of heat fusion bonding. The stretchable sheet of the present invention can be used by heat fusion bonding to a substrate, or it can be used without heat fusion bonding. When heat fusion bonding to a substrate, the heat fusion bonding temperature is not particularly limited. From the viewpoint of ease of use in various applications, the stretchable sheet is preferably heat fused at a temperature preferably below 215°C, more preferably below 205°C, further preferably below 195°C, even more preferably below 185°C, particularly preferably below 175°C, even more preferably below 170°C, especially preferably below 160°C, even more preferably below 150°C, and even more preferably below 140°C. It should be noted that heat fusion bonding is achieved by tightly bonding the molten stretchable sheet to the substrate, therefore heat fusion bonding is more likely to occur at high temperatures. On the other hand, from the viewpoint of reducing the impact of heat on the substrate and reducing the load on production equipment, a low heat fusion bonding temperature is preferred. In this specification, the statement that the stretchable sheet can be heat-fused below a specific temperature does not preclude the possibility of heat-fused bonding at temperatures higher than that temperature; it simply means that the lower limit of the temperature range at which heat-fused bonding is possible is below the specific temperature. To determine whether the stretchable sheet can be heat-fused at a specific temperature, the stretchable sheet is overlapped with a test substrate, and a flatbed press (e.g., a flat automatic press HP-54N) is used at a specific temperature and a pressure of 4.0 N / cm. 2 If, after 20 seconds of bonding, the sheet and substrate adhere without peeling, it is determined that heat-melting bonding is possible at that temperature. Furthermore, for stretch sheets, it has been confirmed that heat-melting bonding is possible at a temperature 15°C or higher than the flow start temperature of the resin composition forming the stretch sheet. Therefore, the flow start temperature of the resin composition + 15°C can be used as the lower limit of the heat-melting bonding temperature.

[0124] Regarding the shape of the stretchable sheet of the present invention, there is no particular limitation as long as the thickness is less than 200 μm; for example, it can be a film, strip, or other shape of a given size. Furthermore, the stretchable sheet can be processed to be porous as needed, or it can be left unprocessed. In a preferred embodiment, the stretchable sheet of the present invention is a non-porous sheet.

[0125] In a preferred embodiment of the present invention, the elastic sheet is an elastic strip, such as an elastic strip with a long strip wound around a core material. The size of the elastic strip can be appropriately set according to the intended use of the elastic strip and is not particularly limited. For example, the width is preferably 1.0 to 5.0 cm, more preferably 1.5 to 4.5 cm, and even more preferably 2.0 to 4.0 cm. In addition, the length is preferably 20 to 50 m, more preferably 25 to 45 m, and even more preferably 30 to 40 m.

[0126] (Manufacturing method of stretchable sheet)

[0127] The manufacturing method of the stretchable sheet is not particularly limited as long as it can produce a thin stretchable sheet with a thickness of 200 μm or less using the above-described resin composition. It can be appropriately selected according to the desired shape of the sheet. For example, the stretchable sheet of the present invention can be manufactured by molding the resin composition into a sheet with a thickness of 200 μm or less using a processing machine such as a hot press roller, hot press, injection molding machine, insert injection molding machine, sheet forming machine, co-extrusion sheet forming machine, extrusion molding machine, or calendering roll forming machine. To obtain multilayer sheets, a co-extrusion sheet forming machine, extrusion lamination molding machine, or wet lamination machine can be used. A method can be used whereby the resin composition is dissolved in a solvent such as toluene, and the solution is coated onto a heated casting roller or a release film and then dried. Alternatively, after manufacturing a sheet with a thickness exceeding 200 μm using any of the above methods, further processes such as hot pressing and stretching can be performed to adjust the thickness to 200 μm or less, thereby manufacturing the stretchable sheet of the present invention.

[0128] The stretch sheet of the present invention can be used as a stretch member in its original state or in a state in which it is laminated with at least one substrate. For example, in applications such as clothing, the stretch sheet of the present invention can be used as a strip for stretchable parts, as a fastening part at the end, as a reinforcing material for parts where it is required to prevent the fabric from loosening, or as a seam tape for parts where waterproofing is required.

[0129] [Layered structure]

[0130] The present invention also provides a laminate formed by laminating the elastic sheet of the present invention with, for example, at least one substrate. For example, by laminating the elastic substrate with the elastic sheet of the present invention, and by heating and hot-melting and / or sewing the substrate and the elastic sheet as needed, a laminate having a substrate layer and a resin layer formed from the elastic sheet of the present invention can be obtained. The present invention also provides a laminate having at least an elastic substrate layer (1) and a resin layer (2) adjacent to the elastic substrate layer, the resin layer (2) being a layer formed from the elastic sheet of the present invention.

[0131] The stretchable substrate layer (1) is a layer of substrate with stretchability. Examples of such substrates include woven fabrics, nonwoven fabrics, and synthetic resin films. The laminate of the present invention is preferably a stretchable laminate.

[0132] The manufacturing method of the laminate of the present invention is not particularly limited. For example, one can overlap one or both sides of the elastic sheet of the present invention onto the elastic substrate, and heat and pressurize as needed to thermally bond the elastic substrate and the elastic sheet together. Alternatively, the laminate of the present invention can be manufactured by overlapping the elastic substrate onto one or both sides of the elastic sheet of the present invention and sewing them together.

[0133] The aforementioned stretchable sheets and laminates can be used in components for various applications that possess stretchable components. For example, they are particularly useful as materials for clothing, health products, medical supplies, sports equipment (especially sportswear), underwear, etc.

[0134] Example

[0135] The present invention will be described below by way of examples, but the present invention is not limited to these examples in any way. First, the methods for determining the physical property values ​​in the examples and comparative examples are as follows.

[0136] [Weight-average molecular weight]

[0137] The weight-average molecular weight was determined by gel permeation chromatography (GPC) under the following conditions.

[0138] Measurement conditions:

[0139] GPC; LC Solution (manufactured by SHIMADZU)

[0140] Detector: Differential refractometer RID-10A (manufactured by SHIMADZU)

[0141] Column: Two TSKgelG4000Hxl tubes connected in series (made by TOSOH)

[0142] Guard column: TSKguardcolumnHxl-L (manufactured by TOSOH)

[0143] Solvent: Tetrahydrofuran

[0144] Temperature: 40℃

[0145] Flow rate: 1 ml / min

[0146] Concentration: 2mg / ml

[0147] Melt Flow Rate (MFR)

[0148] The MFR of the resin composition was determined according to JIS K7210-1:2014 under conditions of 190°C and 2.16 kg load. It should be noted that if the resin composition does not flow at 190°C, the MFR cannot be determined and is recorded as "×". Additionally, values ​​of 55 or higher are recorded as "○".

[0149] 〔hardness〕

[0150] Type A hardness tester

[0151] Three test pieces (2 mm thick, totaling 6 mm) were stacked together after being conditioned for one day indoors at 23°C and 50% humidity. The hardness of the stack was measured using a Type A hardness tester 3 seconds after the start of the test, according to JIS K6253-3:2012. Hardness of 80 or higher was recorded as "hard".

[0152] [Elongation (winding speed at break)]

[0153] Stretchability was evaluated as an indicator of film formability. Stretchability is an indicator of thermoforming, blow molding, foam molding, etc., and an improvement in stretchability can be regarded as an improvement in molding processability.

[0154] The ductility was measured as described below.

[0155] Using a Capillograph 1D PMD-C (Toyo Seiki Co., Ltd.), extrusion was performed at a piston extrusion speed of 10 mm / min, and the winding speed at which the wire broke was recorded [m / min]. The die orifice diameter was set to 1.0 mm, and the temperature was set to 170°C. Seven measurements were performed, and the median was taken as the ductility value.

[0156] [Flow start temperature and meltable bonding temperature]

[0157] The flow test was conducted using a flow tester (Shimadzu Corporation, trade name: CFT-500D) with a 10 mm long die and a 1.0 mm aperture. A 1.7 g film of the resin composition was weighed, placed in the testing apparatus, and the temperature at which the resin began to flow was taken as the flow initiation temperature for each sample under a load of 15 kgf and a heating rate of 5 °C / min. The temperature obtained by adding 15 °C to the flow initiation temperature was taken as the melt-bonding temperature.

[0158] [Tension at 100% elongation and stress at 100% elongation]

[0159] Tension at 100% elongation and stress at 100% elongation were measured using a tensile testing machine (Autograph tensile testing machine (AGX-V) manufactured by Shimadzu Corporation).

[0160] A rectangular test piece with a width of 5 mm and a length of 80 mm was prepared, with markings spaced 20 mm apart in the center. One end of the test piece was fixed with a fixed clamp (chuck), and the other end was fixed with a movable clamp (chuck). It was elongated at a speed of 300 mm / min until the distance between the markings reached 40 mm (100% elongation). The tension measured at this point was taken as the tension (N) at 100% elongation for each specimen. Furthermore, the tension per unit cross-sectional area at 100% elongation and the stress at 100% elongation (MPa) were calculated.

[0161] [The length recovery rate A of the elastic band after repeated 100% elongation at room temperature (3 times)]

[0162] Cyclic tests at 100% elongation were performed using a tensile testing machine (Autograph tensile testing machine (AGX-V) manufactured by Shimadzu Corporation).

[0163] A rectangular test piece with a width of 5 mm and a length of 80 mm was prepared, with 20 mm intervals marked in the center. One end of the test piece was fixed with a fixed clamp (chuck), and the other end was fixed with a movable clamp (chuck). It was stretched at a speed of 300 mm / min until the distance between the marks reached 40 mm (100% elongation), and then returned to the initial chuck position at a speed of 300 mm / min. This process was repeated three times. The test piece was removed from the apparatus, and the length between the marks was measured after three cycles of tensile testing. Based on the results, the recovery rate (recovery rate A) of the length of the stretchable band after three cycles of 100% elongation at room temperature was calculated using the following formula.

[0164] Response rate A (%) = (1 - (L) β -L α ) / L α )×100

[0165] L α Initial spacing between markings (20mm)

[0166] L β 3. Distance between markings after cyclic tensile test (mm)

[0167] [The length recovery rate B of the elastic band after it has been held at 50% elongation for 2 hours at 35°C]

[0168] A rectangular test piece with a width of 5mm and a length of 80mm was made, and markings with 20mm intervals were set in the center.

[0169] One end of the test piece was fixed with a fixed clamp (chuck), and the other end was fixed with a movable clamp (chuck), allowing it to stretch until it reached 50% elongation (30 mm between the marks) and then fixed. After standing in an oven at 35°C for 2 hours, the tensile stress was released, and after naturally cooling at room temperature (25°C) for 10 minutes, the length between the marks was measured. Based on the results, the recovery rate (recovery rate B) of the length of the stretchable strip after maintaining 50% elongation at 35°C for 2 hours was calculated using the following formula.

[0170] Response rate B (%) = (1 - (L1 - L0) / L0) × 100

[0171] L0: Initial distance between markings (20mm)

[0172] L1: Distance between markings (mm) after maintaining a temperature of 35℃ for 2 hours.

[0173] 〔thickness〕

[0174] The thickness was determined by micrometer method according to 7.4.1.1 of JIS C2330 (2001).

[0175] [Example 1]

[0176] The hydrocarbon softener (b1) (PW-100G, paraffin oil, manufactured by Idemitsu Kosan Co., Ltd.) 80 parts by weight, the styrene-containing oligomer (c1) (FTR2140, α-methylstyrene-styrene copolymer, weight average molecular weight 3230, manufactured by Mitsui Chemicals Co., Ltd.), and the polyolefin resin (d1) (Evolue, manufactured by Prime Polymer Co., Ltd.) were extruded using a twin-screw extruder at 200°C. 7 parts by weight of SP1071C, C6-LLDPE, MFR: 10 g / 10 min (230 °C, 2.16 kg load), melting point 112 °C, metallocene catalyst) were mixed with 70 parts by weight of copolymer (a1) (SEPTON4033 manufactured by Kuraray Co., Ltd., styrene content: 30% by weight, Mw: 92,000, hardness 76A) and 30 parts by weight of copolymer (a2) ("SEPTON2002", manufactured by Kuraray Co., Ltd., styrene content: 30% by weight, Mw: 54,000, MFR: 70 g / 10 min, hardness 80A) to obtain resin composition 1.

[0177] Resin composition 1 was fed into an extrusion lamination molding machine (T-die type single-layer extrusion lamination molding machine, diameter 40mm, L / D=24), and resin composition 1 was extruded at an extrusion temperature of 200℃ to obtain a stretchable sheet 1 with a thickness of 75μm.

[0178] [Example 2]

[0179] The resin composition 1 obtained in the same manner as in Example 1 was fed into an extrusion lamination molding machine (T-die type single-layer extrusion lamination molding machine, diameter 40mm, L / D=24), and the resin composition 1 was extruded at an extrusion temperature of 200°C to obtain a stretchable sheet 2 with a thickness of 150μm.

[0180] [Example 3]

[0181] By replacing the hydrocarbon softener (b1) (PW-100G manufactured by Idemitsu Kosan Co., Ltd., paraffin oil) in Example 1 with the hydrocarbon softener (b2) (PW-380 manufactured by Idemitsu Kosan Co., Ltd., hydrogenated high viscosity paraffin oil), a stretchable sheet 3 with a thickness of 75 μm was also obtained.

[0182] [Example 4]

[0183] The styrene-containing oligomer (c1) (FTR2140 manufactured by Mitsui Chemicals Co., Ltd., α-methylstyrene-styrene copolymer) in Example 1 was replaced with a styrene-containing oligomer (c2) (Kristalex 5140 manufactured by EASTMAN, weight average molecular weight 4900). Otherwise, a stretchable sheet 4 with a thickness of 75 μm was obtained.

[0184] [Example 5]

[0185] The copolymer (a1) of Example 1 (SEPTON4033 manufactured by Kuraray Co., Ltd., styrene content: 30% by mass, Mw: 92,000, hardness 76A) was changed to copolymer (a3) ​​(TAIPOL6150 manufactured by TSRC Co., Ltd., styrene content: 29% by mass, Mw: 90,000, hardness 76A), and a stretchable sheet 5 with a thickness of 75 μm was obtained in the same way.

[0186] [Example 6]

[0187] The copolymer (a2) of Example 5 ("SEPTON2002", manufactured by Kuraray Co., Ltd., styrene content: 30% by mass, Mw: 54,000, MFR: 70 g / 10 min, hardness 80A) was changed to copolymer (a4) (TAIPOL6152 manufactured by TSRC, styrene content: 29% by mass, Mw: 55,000, hardness 76A). Otherwise, a stretchable sheet 6 with a thickness of 75 μm was obtained.

[0188] [Example 7]

[0189] The polyolefin resin (d1) of Example 1 (Evolue SP1071C, C6-LLDPE, MFR: 10 g / 10 min (230 °C, 2.16 kg load), melting point 112 °C) was changed to polyolefin resin (d2) (NEO-ZEX 2015M solution-processed C4-LLDPE, MFR: 1.2 g / 10 min (230 °C, 2.16 kg load), melting point 121 °C), and a stretchable sheet 7 with a thickness of 75 μm was obtained in the same way.

[0190] [Examples 8-20]

[0191] The composition of each component was changed as shown in Tables 1 and 2. Otherwise, stretchable sheets 8-20 with a thickness of 75 μm were obtained in the same manner as in Example 1.

[0192] [Example 21]

[0193] The copolymer (a1) of Example 11 (SEPTON 4033 manufactured by Kuraray Co., Ltd., styrene content: 30% by mass, Mw: 92,000, hardness 76A) was changed to copolymer (a1') (SEPTON 4044 manufactured by Kuraray Co., Ltd., styrene content: 30% by mass, Mw: 92,000, hardness 76A). Otherwise, a stretchable sheet 21 with a thickness of 75 μm was obtained in the same manner as in Example 1.

[0194] [Comparative Examples 1-3]

[0195] The composition of each component was modified as shown in Table 2, and otherwise, a stretchable sheet was obtained in the same manner as in Example 1. It should be noted that the copolymer (a5) was "SEPTON4055" manufactured by Kuraray Co., Ltd., with a styrene content of 30% by mass and a Mw of 298,000. Furthermore, the hardness could not be measured.

[0196] [Comparative Example 4]

[0197] The composition of each component was modified according to Table 2 to obtain a resin composition. The obtained resin composition was fed into an extrusion laminator (T-die type single-layer extrusion laminator, 40mm diameter, L / D=24) and extruded at an extrusion temperature of 200°C to form a sheet with a thickness of 200μm. A water-resistant, fabric-free double-sided adhesive sheet (Nitto Denko Corporation HJ-9150W) with release paper adhered to one side of this sheet was then glued on. Next, the obtained sheet was processed using a CO2 laser processing machine (EFL1300 type) manufactured by ELSEngineering to obtain a Φ1mm mesh film.

[0198] [Comparative Examples 5-8]

[0199] The composition of each component was changed as shown in Table 2. Otherwise, a stretchable sheet was obtained in the same manner as in Example 11.

[0200]

[0201]

[0202] The hardness, melt flow rate, flow initiation temperature, melt-bonding temperature, and winding speed at break of the resin compositions obtained in the examples and comparative examples were measured according to the methods described above.

[0203] The thickness, tension at 100% elongation, stress at 100% elongation, recovery rate A, and recovery rate B of the stretchable sheets obtained in the examples and comparative examples were measured according to the method described above. The results are shown in Tables 1 and 2.

[0204] [Clothing pressure]

[0205] The 75 μm thick film from Example 1 and Comparative Example 2 was cut into 1.2 cm × 80 cm pieces, and then heat-bonded on both sides (temperature 160 °C × pressure 0.1 MPa × time 20 seconds) to form a fabric with a plain knit weave (unit area mass 140 g / m²). 2 Composition ratio: polyester / polyurethane = 83 / 17). The ends were further sewn together to create a strap with a width of 1.2cm and a circumference of 75cm.

[0206] As an alternative feature for wearing comfort, the fabricated strap was fitted onto the abdomen of a mannequin with an 80cm waist using a garment pressure measuring device (AMI Techno, model AMI3037-10) at a room temperature of 25°C and a relative humidity of 50%. An air bladder was inserted between the mannequin and the strap, and the amount of air trapped (approximately 0.3cm) was measured. 3 The pressure at that time was calculated, and the results are shown in Table 3.

[0207]

[0208] Although the stretch sheets described in Examples 1-21 have low tension when 100% stretched, their length recovery rate (recovery rate A) is high after being repeatedly stretched to 100% three times at room temperature. Garments using such stretch sheets have low stress and sufficient stretchability, therefore, as shown in Table 3, they have low tightness. Furthermore, the stretch sheets described in Examples 1-21 also have a high length recovery rate (recovery rate B) after being held at 50% stretch for 2 hours at 35°C. Garments using such stretch sheets can withstand repeated stretching and are less prone to loosening. In contrast, as shown in Table 3, the stretch sheets of Comparative Examples 1-3, Comparative Example 5, and Comparative Example 8 cause a feeling of tightness when used in garments. Additionally, the recovery rate B of the stretch sheets of Comparative Examples 1-8 is low, making them prone to loosening. Comparative Examples 4-5 and Comparative Example 8 have poor extensibility, making it impossible to obtain sheets with a thickness of less than 100 μm.

Claims

1. A stretchable sheet formed from a resin composition comprising a copolymer (a), a hydrocarbon softener (b), and a styrene-containing oligomer (c), wherein the hydrocarbon softener (b) comprises 50 to 200 parts by weight relative to 100 parts by weight of the copolymer (a), and the styrene-containing oligomer (c) comprises 5 to 20 parts by weight. The copolymer (a) is a block copolymer or its hydrogenation comprising a polymer block A mainly composed of a vinyl aromatic compound and a polymer block B mainly composed of a conjugated diene compound. The thickness of the stretchable sheet is less than 200 μm.

2. The stretchable sheet according to claim 1, wherein the tension when 100% elongated is less than 1.5 N / 5 mm.

3. The stretchable sheet according to claim 1 or 2, wherein, Based on the total amount of the resin composition, the total amount of copolymer (a), hydrocarbon softener (b), and styrene-containing oligomer (c) is 85% by mass or more.

4. The stretchable sheet according to any one of claims 1 to 3, wherein, The flow start temperature of the resin composition is below 200°C.

5. The stretchable sheet according to any one of claims 1 to 4, which is capable of being heat-fused at a temperature below 170°C.

6. The stretchable sheet according to any one of claims 1 to 5, wherein, The weight-average molecular weight of copolymer (a) is 50,000 to 140,000.

7. The stretchable sheet according to any one of claims 1 to 6, wherein, The copolymer (a) comprises constituent units derived from styrene monomers, and the amount of the constituent units derived from styrene monomers is 15% by mass or more based on the total amount of all constituent units of the copolymer (a).

8. The stretchable sheet according to any one of claims 1 to 7, wherein, The weight-average molecular weight of styrene-containing oligomers (c) is 1000~6000.

9. The stretchable sheet according to any one of claims 1 to 8, wherein, The resin composition further comprises 1 to 50 parts by weight of a polyolefin resin (d) relative to 100 parts by weight of copolymer (a).

10. The stretchable sheet according to claim 9, wherein, The melt flow rate of polyolefin resin (d) is 0.1~100 g / 10 min.

11. The stretchable sheet according to claim 9 or 10, wherein, Polyolefin resin (d) is ethylene with at least one C3-C 12 Copolymers of α-olefins.

12. The stretchable sheet according to any one of claims 1 to 11, wherein, The amount of acrylic block copolymer in the resin composition is more than 0 parts by mass and less than 20 parts by mass relative to 100 parts by mass of copolymer (a).

13. The stretchable sheet according to any one of claims 1 to 12, wherein, The length recovery rate of the stretch sheet after repeated 100% elongation at room temperature was over 99.0%.

14. The stretchable sheet according to any one of claims 1 to 13, wherein, The length recovery rate of the stretch sheet after being held at 50% elongation for 2 hours at 35°C was over 87.0%.

15. The stretchable sheet according to any one of claims 1 to 14, wherein it is a stretchable strip.

16. A laminated body having at least: Expansive substrate layer (1), and The resin layer (2) adjacent to the elastic substrate layer, The resin layer (2) is a layer formed from the stretchable sheet according to any one of claims 1 to 15.

17. The laminate according to claim 16, wherein, The elastic substrate layer (1) and the resin layer (2) are adjacent to each other on both sides.

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