JPWO2017034030A1 - Elastic materials, elastic materials and clothing products - Google Patents

Abstract

An elastic member comprising: an elastic part having a structure in which a skin layer of an elastic material is plastically deformed; and a shape holding part in which the layer structure of the elastic material is maintained.

Description

  One aspect of the present invention relates to a stretchable material capable of forming an elastic web or an elastic film. Another aspect of the present invention relates to a stretchable member that can be suitably used as an elastic web or an elastic film. Another aspect of the present invention relates to a clothing product including an elastic material or an elastic member.

  Conventionally, elastic materials such as an elastomer film in which a skin layer is laminated on an elastomer core are known. For example, Patent Document 1 discloses a multilayer elastomer laminate including an elastomer layer and an inelastic skin layer, and discloses that the multilayer elastomer laminate is used for clothing and the like.

JP-T-5-501386

  Stretchable members such as elastic webs are required to have good bondability with other members when applied to clothing products and the like.

  Further, in one aspect, the stretchable member is required to have uniform stretch when stretched because stretchability of the stretchable portion may impair wearability and comfort during wearing. ing.

  Further, in another aspect, when the stretchable member is applied to a clothing product that is in close contact with the skin, when the width of the stretchable portion when stretched becomes small, the tightening force is likely to act locally and comfortable when worn. There is a risk of damage. In addition, when applied to clothing products, deformation due to repeated use is also a problem.

  In other aspects, clothing products (for example, sanitary goods such as diapers) that employ elastic members such as elastic webs are required to maintain sufficient fit even when worn for a long time. Yes.

  An elastic material according to one aspect of the present invention includes a core layer including an elastomer, and at least one skin including a resin material having a tensile stress higher than that of the core layer in at least one direction and forming a microphase separation structure. A layer.

  In such a side surface, it is possible to obtain a stretchable member in which stretchable portions are arbitrarily formed by stretching a part of the stretchable material and plastically deforming a part of the skin layer. Since the stretchable member includes the stretchable portion and the shape holding portion in which the layer structure of the stretchable material is maintained, the shape holding portion is sufficiently secured to the other member. Moreover, in such a side surface, since the skin layer contains a resin material that forms a microphase separation structure, the skin layer can be plastically deformed uniformly in the stretching direction. When the skin layer is uniformly plastically deformed, the formed stretchable portion is excellent in elongation uniformity during elongation.

  In the elastic material according to one aspect, skin layers may be provided on both main surfaces of the core layer. In such a stretchable material, the tensile stress on both main surfaces becomes more uniform, and when a stretchable portion is provided, warpage due to nonuniform shrinkage is prevented. Further, in such an elastic material, the skin layers come into contact with each other when wound in a roll shape, and therefore between the elastic materials (for example, between the skin layer and the core layer wound on the skin layer). Is prevented, and the workability during unwinding and the storage stability of the stretchable material are improved.

  In one embodiment, the resin material may contain a block copolymer. In such an elastic material, since the microphase separation structure can be easily formed by the block copolymer, the above-described effects can be obtained more remarkably.

  In one embodiment, the thickness of the core layer may be greater than or equal to the thickness of the skin layer. By making the relationship between the thickness of the core layer and the skin layer as described above in the stretchable material in which the skin layer has a microphase separation structure, narrowing (necking) of the stretchable portion at the time of elongation is sufficiently suppressed. That is, in the stretchable member obtained from the stretchable material of this aspect, since necking at the time of extension becomes small, the local action of the tightening force is prevented, and excellent comfort at the time of wearing can be realized. In addition, the stretchable material according to this aspect tends to have a more uniform elongation when stretched.

In one embodiment, the ratio T ₂ / T ₁ of the thickness T ₂ of the skin layer to the thickness T ₁ of the core layer may be 0.1 or more and 1.0 or less, and is 0.2 or more and 0.5 or less. Good. In the stretchable material in which the skin layer has a microphase separation structure, necking at the time of elongation is more significantly suppressed by making the relationship between the thickness of the core layer and the skin layer as described above. For this reason, according to the elastic material which concerns on this aspect, the clothing product which is further excellent in the comfort at the time of wear can be provided. In addition, the stretchable material according to this aspect tends to have a more uniform elongation when stretched.

  In at least one direction, the elastic material according to one aspect may have a tensile stress at 300% elongation of 110% or less of the tensile yield stress of the skin layer. When the stretchable member has a stretchable part and a shape retaining part, if the tensile stress required for stretching is significantly greater than the tensile yield stress of the skin layer, the shape retaining part cannot be plastically deformed during stretching, and the original shape cannot be maintained repeatedly. May interfere with the use of When the tensile stress at the time of 300% elongation is 110% or less of the tensile yield stress of the skin layer, the shape holding part can maintain the original shape even if it is stretched by about 200% which is practically useful. The joining property with the member is further improved, and repeated use is possible.

  In at least one direction, the stretchable material according to one aspect may have a shrinkage ratio in the width direction orthogonal to the stretch direction at the time of 200% stretch of 30% or less. When the elastic member has an elastic part and a shape holding part, the width of the shape holding part is maintained at a constant width, and the elastic part is narrowed according to the extension, but when the width of the elastic part becomes extremely narrow at the time of extension, The difference between the width of the shape holding portion and the width of the stretchable portion becomes large. In such a case, particularly when applied to a clothing product that is in close contact with the skin, the wearability may be reduced, or the tightening force may easily act locally, thereby impairing comfort during wearing. In the stretchable material according to this aspect, since the shrinkage ratio in the width direction orthogonal to the stretch direction at the time of 200% elongation is 30% or less, the degree of narrowing of the stretchable portion at the time of elongation is sufficiently small, and the wearability And the comfort at the time of wear can fully be acquired.

  An elastic material according to another aspect of the present invention includes a core layer including an elastomer, and at least one skin layer having a tensile yield stress lower than that of the core layer in at least one direction. The tensile stress at% elongation is 110% or less of the tensile yield stress of the skin layer, and the shrinkage ratio in the width direction perpendicular to the extension direction at 200% elongation is 30% or less.

  In such a side surface, the tensile stress at 300% elongation of the stretchable material is 110% or less of the tensile yield stress of the skin layer. Since the shape can be maintained, the bondability with other members is improved, and repeated use is possible. Moreover, in such a side surface, since the shrinkage ratio in the width direction orthogonal to the stretching direction when the stretchable material is stretched 200% is 30% or less, the degree of narrowing (necking) of the stretchable portion when stretched Is sufficiently small to achieve excellent wearability and comfort when worn.

  In the elastic material according to one aspect, skin layers may be provided on both main surfaces of the core layer. In such an elastic material, the expansion / contraction rate on each main surface side becomes uniform, and warpage at the time of contraction is prevented.

  In one embodiment, the thickness of the core layer may be greater than or equal to the thickness of the skin layer. By making the relationship between the thickness of the core layer and the skin layer as described above in the stretchable material having the relationship between the tensile stress and the shrinkage rate described above, necking of the stretchable portion at the time of extension is more significantly suppressed. That is, in the elastic member obtained from the elastic material of this aspect, necking at the time of extension is further reduced, so that local action of the tightening force is prevented and excellent comfort at the time of wearing can be realized. In addition, the stretchable material according to this aspect tends to have a more uniform elongation when stretched.

In one embodiment, the ratio T ₂ / T ₁ of the thickness T ₂ of the skin layer to the thickness T ₁ of the core layer may be 0.1 or more and 1.0 or less, and is 0.2 or more and 0.5 or less. Good. In the stretchable material having the relationship between the tensile stress and the shrinkage rate described above, necking at the time of elongation is further remarkably suppressed by making the relationship between the thickness of the core layer and the skin layer as described above. For this reason, according to the elastic material which concerns on this aspect, the clothing product which is further excellent in the comfort at the time of wear can be provided. In addition, the stretchable material according to this aspect tends to have a more uniform elongation when stretched.

  Another aspect of the present invention relates to a stretchable member including a stretchable portion having a structure in which a skin layer of the stretchable material is plastically deformed, and a shape holding portion in which the layered structure of the stretchable material is maintained. Such a stretchable member can be produced from the stretchable material described above, and good jointability with other members can be obtained in the shape holding portion.

  Another aspect of the present invention relates to a method for producing a stretchable member, comprising a step of stretching at least a portion of the stretchable material and plastically deforming at least a portion of the skin layer.

  In one aspect, in the above step, a part of the skin layer may be plastically deformed to form a shape holding portion in which the layer structure of the stretchable material is maintained and a stretchable portion in which the skin layer is plastically deformed.

  Another aspect of the present invention relates to a clothing product including the stretchable member.

  An elastic material according to another aspect of the present invention includes a core layer containing an elastomer and at least one skin layer having a higher 10% tensile stress than the core layer in at least one direction, and stretches in 300% in one direction. Then, when the stretchable part is formed by plastically deforming the skin layer, the stretchable part has a strain of 25% or less by stretching 160% and holding at 40 ° C. for 1 hour.

  According to such an elastic material, an elastic member in which an elastic part is arbitrarily formed can be obtained by extending a part of the elastic material and plastically deforming a part of the skin layer. And since the said elastic member is hard to produce distortion even when the expansion-contraction part is hold | maintained in the expansion | extension state, when it applies to clothing products, it can fully maintain the excellent fitting property also by long-time wearing. .

  The stretchable member may include a stretchable portion and a shape holding portion that maintains the layer structure of the stretchable material. When such a stretchable member is applied to a clothing product, the stretchable part expands when worn and the shape holding part maintains its shape. For this reason, the said elastic | stretch member is obtained by joining with another member in a shape holding part, and favorable joining property with another member is acquired.

  In the elastic material according to one aspect, skin layers may be provided on both main surfaces of the core layer. In such an elastic material, the tensile stress on both main surfaces becomes more uniform, and when an expansion / contraction part is provided, warpage or the like due to non-uniform expansion / contraction is prevented. Moreover, in such an elastic material, since skin layers contact each other when rolled up in a roll shape, blocking between the elastic materials is prevented, and workability during unwinding and storage stability of the elastic material are good. Become.

  In one embodiment, the thickness of the core layer may be greater than or equal to the thickness of the skin layer. By making the relationship between the thicknesses of the core layer and the skin layer as described above, narrowing (necking) of the stretchable part during stretching tends to be suppressed. That is, in the stretchable member obtained from the stretchable material of this aspect, since necking at the time of extension becomes small, the local action of the tightening force is prevented, and excellent comfort at the time of wearing can be realized.

In one embodiment, the ratio T ₂ / T ₁ of the thickness T ₂ of the skin layer to the thickness T ₁ of the core layer may be 0.1 or more and 1.0 or less. By making the relationship between the thicknesses of the core layer and the skin layer as described above, necking during stretching tends to be remarkably suppressed. For this reason, according to the elastic material of this aspect, the clothing product excellent in the comfort at the time of wear can be provided.

  In at least one direction, the elastic material according to one aspect may have a tensile stress at 300% elongation of 110% or less of the tensile yield stress of the skin layer. When the stretchable member has a stretchable part and a shape-retaining part, if the tensile stress required for elongation is significantly greater than the tensile yield stress of the skin layer, the skin layer of the shape-retaining part can be plastically deformed during stretching to maintain the original shape. In some cases, repeated use may be hindered. If the tensile stress at the time of 300% elongation is 110% or less of the tensile yield stress of the skin layer, the shape holding part can maintain the original shape even if the elongation is about 200% that is practically useful. Bondability with the member becomes even better, and good bondability is maintained even after repeated use.

  An elastic material according to another aspect of the present invention includes a core layer containing an elastomer and at least one skin layer having a 10% tensile stress higher than the core layer in at least one direction, and the elastomer comprises a branched polymer. contains.

  According to such an elastic material, an elastic member in which an elastic part is arbitrarily formed can be obtained by extending a part of the elastic material and plastically deforming a part of the skin layer. And since the elastomer of the core layer contains a branched polymer, the stretchable member is less likely to be distorted even if the stretchable portion is held in an expanded state, and therefore has excellent fit when worn for a long time. Well maintained.

  The stretchable member may include a stretchable portion and a shape holding portion that maintains the layer structure of the stretchable material. When such a stretchable member is applied to a clothing product, the stretchable part expands when worn and the shape holding part maintains its shape. For this reason, the said elastic | stretch member is obtained by joining with another member in a shape holding part, and favorable joining property with another member is acquired.

  In one embodiment, the elastomer may further contain a linear polymer. Thereby, effects such as improvement of processability to the film are exhibited.

  In the elastic material according to one aspect, skin layers may be provided on both main surfaces of the core layer. In such an elastic material, the tensile stress on both main surfaces becomes more uniform, and when an expansion / contraction part is provided, warpage or the like due to non-uniform expansion / contraction is prevented. Moreover, in such an elastic material, since skin layers contact each other when rolled up in a roll shape, blocking between the elastic materials is prevented, and workability during unwinding and storage stability of the elastic material are good. Become.

  In one embodiment, the thickness of the core layer may be greater than or equal to the thickness of the skin layer. By making the relationship between the thicknesses of the core layer and the skin layer as described above, narrowing (necking) of the stretchable part during stretching tends to be suppressed. That is, in the stretchable member obtained from the stretchable material of this aspect, since necking at the time of extension becomes small, the local action of the tightening force is prevented, and excellent comfort at the time of wearing can be realized.

In one embodiment, the ratio T ₂ / T ₁ of the thickness T ₂ of the skin layer to the thickness T ₁ of the core layer may be 0.1 or more and 1.0 or less. By making the relationship between the thicknesses of the core layer and the skin layer as described above, necking during stretching tends to be remarkably suppressed. For this reason, according to the elastic material of this aspect, the clothing product excellent in the comfort at the time of wear can be provided.

  In at least one direction, the elastic material according to one aspect may have a tensile stress at 300% elongation of 110% or less of the tensile yield stress of the skin layer. When the stretchable member has a stretchable part and a shape-retaining part, if the tensile stress required for elongation is significantly greater than the tensile yield stress of the skin layer, the skin layer of the shape-retaining part can be plastically deformed during stretching to maintain the original shape. In some cases, repeated use may be hindered. If the tensile stress at the time of 300% elongation is 110% or less of the tensile yield stress of the skin layer, the shape holding part can maintain the original shape even if the elongation is about 200% that is practically useful. Bondability with the member becomes even better, and good bondability is maintained even after repeated use.

  Another aspect of the present invention relates to a stretchable member including a stretchable portion having a structure in which a skin layer of the stretchable material is plastically deformed and a shape holding portion in which the layered structure of the stretchable material is maintained. Such an elastic member sufficiently maintains the elasticity of the expansion / contraction part even after repeated use, and therefore, when applied to a clothing product, the fit at the time of wearing is sufficiently maintained.

  Another aspect of the present invention relates to a method for producing a stretchable member, comprising a step of stretching at least a portion of the stretchable material and plastically deforming at least a portion of the skin layer.

  In one aspect, in the above step, a part of the skin layer may be plastically deformed to form a shape holding portion in which the layer structure of the stretchable material is maintained and a stretchable portion in which the skin layer is plastically deformed.

  Another aspect of the present invention relates to a clothing product including the stretchable material or the stretchable member.

  According to one aspect of the present invention, it is possible to provide a stretchable member capable of obtaining good bondability with other members when applied to clothing products and the like.

  Moreover, according to the other one side surface, the elastic member which has an expansion-contraction part excellent in the elongation uniformity at the time of expansion | extension can be provided. In addition, according to another aspect, it is possible to provide an extensible member that is sufficiently prevented from being deformed by extension and can be used repeatedly. Moreover, according to the other one side surface, the local effect | action of a clamping force is prevented and the elastic member which can implement | achieve the outstanding mounting | wearing property and the comfort at the time of wear can be provided.

  Moreover, according to the other one aspect | mode of this invention, the clothing material provided with the elastic material for producing the above-mentioned elastic member, the manufacturing method of an elastic member, and an elastic member is provided.

  In another aspect of the present invention, there is provided an elastic member capable of sufficiently maintaining good fit even when worn for a long time when applied to clothing products and the like. In another aspect of the present invention, there is provided a stretchable member capable of obtaining good bondability with other members when applied to clothing products and the like.

  Moreover, in the other one side surface of this invention, the elastic material for producing the above-mentioned elastic member, and the manufacturing method of an elastic member are provided.

  Furthermore, in another aspect of the present invention, there is provided a clothing product comprising the above-described stretchable material or stretchable member.

FIG. 1 is a plan view showing an embodiment of an elastic material. FIG. 2 is an enlarged cross-sectional view taken along line II-II in FIG. FIG. 3A and FIG. 3B are diagrams for explaining one aspect of the stretching process of the elastic material. FIG. 4 is a plan view showing an aspect of the stretchable member. FIG. 5 is a diagram showing the relationship between the stretch rate of the stretchable material and the stretchable member and the tensile stress. FIG. 6 is a plan view showing an aspect of the stretchable material. FIG. 7 is an enlarged cross-sectional view showing a cross section taken along line II-II in FIG. 6. Fig.8 (a) and FIG.8 (b) are the figures for demonstrating the one aspect | mode of the extending | stretching process of an elastic material. FIG. 9 is a plan view showing one embodiment of the stretchable member. FIG. 10A, FIG. 10B, and FIG. 10C are diagrams for explaining the extension test of the stretchable part. FIG. 11 is a diagram illustrating an example of the relationship between the elongation rate of the stretchable material and the stretchable member and the tensile stress.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the drawings are partially exaggerated for easy understanding, and dimensional ratios and the like are not limited to those described in the drawings.

[First embodiment]
A preferred first embodiment of the stretchable material, stretchable member and clothing product according to the present invention will be described below.

(Elastic material)
The elastic material according to the present embodiment includes a core layer containing an elastomer and a skin layer having a tensile yield stress lower than that of the core layer in at least one direction.

  The stretchable material can form a stretchable member having a stretchable part by plastically deforming at least a part of the skin layer by a stretching process. In forming the stretchable member, only a part of the skin layer may be plastically deformed to provide a portion (shape holding portion) in which the layer structure of the stretchable material is maintained. The stretchable member having the shape holding portion ensures good bondability with other members in the shape holding portion.

  In this embodiment, the stretchable material may have a layer structure (skin layer / core layer / skin layer) in which skin layers are laminated on both main surfaces of the core layer. In such a stretchable material, the tensile stress on both main surfaces becomes more uniform, and when a stretchable portion is provided, warpage due to nonuniform shrinkage is prevented. Further, in such an elastic material, the skin layers come into contact with each other when wound in a roll shape, and therefore between the elastic materials (for example, between the skin layer and the core layer wound on the skin layer). Is prevented, and the workability during unwinding and the storage stability of the stretchable material are improved. The layer structure of the elastic material is not limited to this. For example, the elastic material may have a layer structure (core layer / skin layer) in which a skin layer is laminated only on one side of the core layer. You may have the layer structure (core layer / skin layer / core layer) by which the core layer was each laminated | stacked on both main surfaces.

  In the present embodiment, the core layer and the skin layer may be directly bonded or indirectly bonded via an intermediate layer. The intermediate layer may be, for example, an adhesive layer that joins a modification layer containing a coloring material, a core layer, and a skin layer. The bonding mode of the core layer and the skin layer is not particularly limited. For example, the resin materials constituting the core layer and the skin layer may be fused to each other and bonded by an adhesive layer interposed between the core layer and the skin layer. It may be.

In the present embodiment, the thickness T ₁ of the core layer may be a thickness T ₂ or more skin layers. In such a stretchable material, narrowing (necking) of the stretchable portion at the time of extension is more significantly suppressed. That is, in the stretchable member obtained from such a stretchable material, necking at the time of extension is reduced, so that local action of the tightening force is prevented, and excellent comfort when worn can be realized. In particular, when the skin layer has a microphase separation structure to be described later, necking is more significantly suppressed and the comfort during wearing is further improved by making the relationship between the thickness of the core layer and the skin layer as described above. . Moreover, in such an elastic material, there exists a tendency for the elongation at the time of expansion | extension to become more uniform.

In this embodiment, the ratio _T 2 / _{T 1} of the thickness _{T 2} of the skin layer to the thickness _{T 1} of the core layer may be 0.1 to 1.0, a 0.2 to 0.5 It's okay. According to such an elastic material, since necking at the time of expansion | extension is suppressed notably, the clothing product which is further excellent in the comfort at the time of wear can be provided. In particular, when the skin layer has a microphase separation structure to be described later, necking is more significantly suppressed and the comfort during wearing is further improved by making the relationship between the thickness of the core layer and the skin layer as described above. . Moreover, in such an elastic material, there exists a tendency for the elongation at the time of expansion | extension to become more uniform.

Incidentally, when a plurality of the skin layer is laminated to the stretchable material, the thickness T ₂ of the skin layer exhibits a total thickness of each skin layer. Further, when a plurality of the core layer is laminated stretchable material, the thickness T ₁ of the core layer exhibits a total thickness of each core layer.

  In the present embodiment, the stretchable material may have a tensile stress at 300% elongation in at least one direction of 110% or less of the tensile yield stress of the skin layer in the same direction. When the stretchable member has a stretchable part and a shape retaining part, if the tensile stress required for stretching is significantly greater than the tensile yield stress of the skin layer, the shape retaining part cannot be plastically deformed during stretching, and the original shape cannot be maintained repeatedly. May interfere with the use of If the tensile stress at the time of 300% elongation does not greatly exceed the tensile yield stress of the skin layer, the shape holding part can maintain the original shape even if the practically useful elongation of about 200% is performed. Bondability is further improved and repeated use is possible. In such a stretchable material, a stretchable portion may be formed by stretching in a direction in which the tensile stress at 300% elongation and the tensile yield stress of the skin layer satisfy the above relationship.

  In the present embodiment, the tensile stress at 300% elongation of the stretchable material is measured at a test piece width of 25 mm, a chuck interval of 50 mm, and a test speed of 300 mm / min in accordance with JIS K7127. Further, the tensile yield stress of the skin layer is measured according to JIS K 7127 at a test piece width of 25 mm, a chuck interval of 50 mm, and a test speed of 300 mm / min. When the stretchable material has a plurality of skin layers, the maximum tensile yield stress of each skin layer is referred to as “tensile yield stress of skin layer”. The tensile yield stress of the skin layer may be measured by peeling only the skin layer from the elastic material, and may be measured using a test piece equivalent to the skin layer. As a simple discrimination method, in the tensile stress test of the stretchable material, the yield point at which all skin layers are plastically deformed can be regarded as the tensile yield stress of the skin layers.

  In this embodiment, when the stretchable material is stretched 200% in at least one direction, the shrinkage ratio in the width direction orthogonal to the stretch direction (ratio of the width shrunk by stretching to the width before stretching) is 30%. Or less, preferably 25% or less, more preferably 20% or less, still more preferably 15% or less, and even more preferably 10% or less. When the elastic member has the expansion / contraction part and the shape holding part, the width of the shape holding part is maintained at a constant width, and the expansion / contraction part is narrowed according to the extension. Here, when the width of the expansion / contraction part becomes extremely narrow at the time of extension, the difference between the width of the shape holding part and the width of the expansion / contraction part becomes large. In such a case, particularly when applied to a clothing product that is in close contact with the skin, the wearability may be reduced, or the tightening force may easily act locally, thereby impairing comfort during wearing. In the stretchable material, the degree of shrinkage in the width direction perpendicular to the stretched direction when stretched 200% is 30% or less, and the degree of narrowing of the stretchable portion when stretched is sufficiently small. The comfort of the time can be sufficiently secured. In such a stretchable material, the stretchable portion may be formed by stretching in a direction in which the shrinkage rate falls within the above range.

  In the present embodiment, the contraction rate in the width direction orthogonal to the extension direction at the time of 200% extension indicates a value measured by the following method. First, a rectangular test piece (width 50 mm, length 50 mm or more) having a long side and a short side along an extending direction and a width direction perpendicular thereto is prepared. The both ends in the extending direction of the test piece are sandwiched so that the length of the extending portion is 50 mm, and extended by 200% in the extending direction. When the initial width of the test piece is L1, and the minimum width of the test piece at 200% stretching is L2, the shrinkage rate (%) is calculated by (L2 / L1) × 100.

  Below, each layer which comprises the elastic material which concerns on this embodiment is explained in full detail.

<Core layer>
The elastic material according to this embodiment includes a core layer containing an elastomer. A core layer is a layer which bears the elastic function of an elastic member, The composition etc. may be selected so that it may have desired rubber elasticity.

  The elastomer contained in the core layer is a material having rubber elasticity, and the core layer has a 10% tensile stress lower than that of the skin layer. In this embodiment, the 10% tensile stress is also called 10% Modulus, and is a force per unit area necessary for 10% elongation, and is measured according to JIS K 6251.

  The 10% tensile stress of the core layer may be, for example, 0.5 MPa or less, 0.3 MPa or less, or 0.1 MPa or less. Thereby, since it stretches following small stress, the elastic member excellent in handleability is obtained. The core layer may have a 10% tensile stress in the above range in at least one direction. The core layer may have a 10% tensile stress in the above range in the stretching direction of the elastic material.

  The 300% tensile stress of the core layer may be 4 MPa or less, for example, or 2 MPa or less. Thereby, since it stretches following small stress, the elastic member excellent in handleability is obtained. The 300% tensile stress of the core layer may be, for example, 1 MPa or more, and preferably 1.5 MPa or more. Thereby, extending without limit is suppressed. The core layer may have 300% tensile stress in the above range in at least one direction. The core layer may have a 300% tensile stress in the above range in the stretching direction of the stretchable material.

The core layer thickness T ₁ may be, for example, 10 μm or more, and is preferably 15 μm or more. Further, the thickness T _{1 of the} core layer may be, for example, 100 μm or less, 50 μm or less, or 35 μm or less from the viewpoint of reducing the material cost while obtaining a sufficient effect.

  The core layer may be made of a resin material containing an elastomer (hereinafter also referred to as “resin material (A)”). The type of elastomer is not particularly limited. For example, styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene / butylene-styrene block copolymer (SEBS), polyurethane, ethylene copolymer (For example, ethylene vinyl acetate, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer), propylene oxide (PO) and the like.

  The resin material (A) constituting the core layer may contain components other than those described above. For example, the resin material (A) is made of a stiffening agent (eg, polyvinyl styrene, polystyrene, poly α-methyl styrene, polyester, epoxy resin, polyolefin, coumarone-indene resin), a viscosity reducing agent, a plasticizer, a tackifier ( For example, aliphatic hydrocarbon tackifier, aromatic hydrocarbon tackifier, terpene resin tackifier, hydrogenated terpene resin tackifier), dye, pigment, antioxidant, antistatic agent, adhesive, tack An inhibitor, slip agent, heat stabilizer, light stabilizer, foaming agent, glass bubble, starch, metal salt, microfiber, and the like may be included.

<Skin layer>
The elastic material according to the present embodiment includes a skin layer having a 10% tensile stress higher than that of the core layer in at least one direction. The skin layer has a function of protecting the core layer in the stretchable material, and is plastically deformed by a stretching process when the stretchable member is manufactured. At this time, the core layer is elastically deformed, and only the skin layer is plastically deformed, so that the stretched portion can be used as the stretchable portion of the stretchable member. The skin layer may have a function of maintaining the shape of the shape holding portion in the stretchable member.

  The 10% tensile stress of the skin layer may be 1 MPa or more, for example, or 2 MPa or more. Thereby, it does not deform | transform with a small tensile stress, and the handleability of an elastic material becomes favorable. Further, the 10% tensile stress of the skin layer may be, for example, 15 MPa or less, or 10 MPa or less. Thereby, the stress for plastically deforming the skin layer can be reduced, and workability is improved. The skin layer may have a 10% tensile stress in the above range in at least one direction. The skin layer may have a 10% tensile stress in the above range in the stretching direction of the elastic material. In this embodiment, the 10% tensile stress of the skin layer is measured in accordance with JIS K 6251.

  The tensile yield stress of the skin layer may be, for example, 2 N / 25 mm or more, preferably 2.5 N / 25 mm or more, more preferably 3 N / 25 mm or more. Further, the tensile yield stress of the skin layer may be, for example, 10 N / 25 mm or less, and preferably 7 N / 25 mm or less. The skin layer may have a tensile yield stress in the above range in at least one direction. Moreover, the skin layer may have the tensile yield stress of the said range in the extending | stretching direction of an elastic material. The tensile yield stress of the skin layer is measured according to JIS K 7127 at a test piece width of 25 mm, a chuck interval of 50 mm, and a test speed of 300 mm / min.

  The tensile yield strain of the skin layer may be, for example, 20% or less, and preferably 15% or less. The skin layer may have a tensile yield strain in the above range in at least one direction. The skin layer may have a tensile yield strain in the above range in the stretching direction of the elastic material. In this embodiment, the tensile yield strain of the skin layer is measured according to JIS K 7127 at a test piece width of 25 mm, a chuck interval of 50 mm, and a test speed of 300 mm / min.

The thickness T _{2 of the} skin layer may be, for example, 2 μm or more, and preferably 5 μm or more from the viewpoints that the above-described preferable tensile properties can be easily obtained and that the production becomes easy. The thickness T ₂ of the skin layers, from the viewpoint of reducing material cost while obtaining a sufficient effect may be for example 30μm or less and preferably 20μm or less.

  The resin material constituting the skin layer (hereinafter also referred to as “resin material (B)”) may form a microphase separation structure. In such a skin layer, since a phase structure that is easily plastically deformed is densely distributed throughout the skin layer, it can be uniformly plastically deformed by a stretching process. Thereby, the stretchable part formed becomes excellent in the uniformity of elongation at the time of extension. Further, since the skin layer has a micro phase separation structure, necking at the time of extension is more remarkably suppressed, and an elastic member that is further excellent in comfort at the time of wearing is realized.

  Further, when such a skin layer is used, the elongation becomes uniform even at a relatively low degree of stretching such as 100% stretching, and therefore any stretching such as 100%, 150%, 200%, 250%, 300%, etc. The stretchable material can be stretched at a degree. Note that when the degree of stretching at the time of the stretching process is different, mechanical properties such as elasticity and tensile stress of the formed stretchable part are changed. That is, in this aspect, the stretchable part having different characteristics can be formed from the same stretchable material by changing the stretching degree during the stretching process. For this reason, for example, even when the required characteristics differ depending on the part of the clothing product, the same stretchable material can be applied to each part by adjusting the degree of stretching according to the desired characteristic.

  The microphase separation structure formed by the resin material (B) may be, for example, a lamellar structure, a gyroid structure, a cylinder structure, a BCC structure, or the like. The microphase-separated structure may be formed by a block copolymer, for example, or may be formed by a polymer blend.

  The resin material (B) may contain a block copolymer. The block copolymer is preferably a block copolymer that forms a microphase-separated structure. Examples of the block copolymer include those containing, as elements, olefins such as ethylene, propylene, and butylene, esters such as ethylene terephthalate, and styrenes such as styrene.

  The resin material (B) may form a microphase separation structure by a polymer blend containing two or more kinds of polymers. Examples of the polymer contained in the resin material (B) include polypropylene, polyethylene, polybutylene, polyethylene terephthalate, and polystyrene.

  The resin material (B) may contain components other than those described above. For example, mineral oil extenders, antistatic agents, pigments, dyes, antiblocking agents, starches, metal salts, stabilizers and the like may be included.

  The manufacturing method of the elastic material according to the present embodiment is not particularly limited, and for example, a general multilayer film forming technique using a resin material can be applied.

  In the elastic material according to the present embodiment, for example, the core layer and the skin layer are integrally formed by simultaneous extrusion molding of the resin material (A) constituting the core layer and the resin material (B) constituting the skin layer. It may be. The conditions for the coextrusion molding may be appropriately adjusted according to the composition of the resin material (A) and the resin material (B). The stretchable material according to the present embodiment may be manufactured by molding and laminating the A layer containing the resin material (A) and the B layer containing the resin material (B), respectively.

(Elastic member)
The stretchable member according to the present embodiment includes a stretchable portion (also referred to as an activation portion) having a structure in which the skin layer of the stretchable material is plastically deformed. The stretchable member according to the present embodiment may further include a shape holding portion (also referred to as an unactivated portion) in which the layer structure of the stretchable material is maintained.

  The stretchable member according to this embodiment can be suitably used as an elastic web applied to clothing products and the like because the stretchable portion functions as a rubber elastic body. In addition, the stretchable member according to the present embodiment can be bonded to another member in the shape holding portion, thereby obtaining good bondability with the other member.

  If the stretchable member has an uneven elongation when stretched, the wearability and the comfort when worn may be impaired. Since the stretchable member according to this embodiment is formed from the above-described stretchable material, it can be excellent in the uniformity of elongation of the stretchable portion.

  In addition, when the stretchable member is applied to a clothing product that is in close contact with the skin, if the width of the stretchable portion when stretched becomes small, the tightening force tends to act locally, which may impair the comfort when worn. is there. Since the stretchable member according to the present embodiment is formed from the above-described stretchable material, the degree of narrowing of the stretchable portion at the time of extension is sufficiently small, and the wearability and comfort at the time of wearing can be sufficiently ensured. .

  In the elastic member, deformation due to repeated use can be a problem when applied to clothing products. Since the stretchable member according to the present embodiment is formed from the above-described stretchable material, the shape holding portion can maintain the original shape even after repeated use, and good bondability with other members can be maintained.

  The stretchable part has a structure in which the skin layer of the stretchable material is plastically deformed. In other words, the stretchable part may include a core layer and a plastically deformed skin layer. In the stretchable part, the plastically deformed skin layer may exist as a continuous layer, or may be divided by stretching.

  The shape holding part has a layer structure of stretchable material. That is, the shape holding part may include a core layer and a skin layer. It can also be said that the shape holding portion is an unstretched portion of the stretchable material.

  The stretchable member is manufactured by subjecting a stretchable material to a stretching treatment depending on the intended use. The use of the elastic member is not particularly limited, and may be used for clothing, for example. More specifically, the elastic member may be, for example, a disposable diaper, an adult incontinence pad, a shower cap, a surgical gown, a hat and booth, a disposable pajamas, a competition shoulder, a clean room garment, a hat head hand or a visor. Etc., and used for an ankle band (for example, a panties cows protector), a wrist band, a rubber pan, a wet suit and the like.

  The method for producing an elastic member includes a step of stretching at least a part of the elastic material and plastically deforming at least a part of the skin layer (also referred to as a step of activating at least a part of the elastic material). It's okay. The stretchable part is formed by stretching the stretchable material until the skin layer is plastically deformed. Plastic deformation is generally achieved by stretching beyond the tensile yield strain of the skin layer.

  In the manufacturing method of the elastic member, the elastic part and the shape holding part may be formed by plastically deforming only a part of the skin layer.

  The stretching method of the elastic material is not particularly limited. For example, by sandwiching and stretching both ends of the stretchable material with a predetermined width, two shape holding portions with a predetermined width (unstretched portions sandwiched) and a stretchable portion formed between the shape holding portions, The elastic member provided is formed.

  The temperature condition at the time of extending | stretching an elastic material is not specifically limited, Room temperature may be sufficient. The stretch ratio of the stretchable material only needs to be equal to or higher than the tensile yield strain of the skin layer, and may be equal to or higher than the stretch ratio practically assumed. Further, as described above, since the mechanical properties of the stretchable part can be changed depending on the stretch ratio, the stretch ratio may be set according to desired characteristics.

  Next, a preferred aspect of the present embodiment will be described with reference to the drawings.

  FIG. 1 is a plan view showing an aspect of the stretchable material according to the present embodiment, and FIG. 2 is an enlarged cross-sectional view taken along line II-II in FIG. As shown in FIGS. 1 and 2, the stretchable material 10 includes a core layer 1 and a skin layer 2 a and a skin layer 2 b provided on both main surfaces of the core layer 1.

In the stretchable material 10, the thickness T ₁ of the core layer 1 is equal to or greater than the total thickness T ₂ of the skin layer 2 a and the skin layer ₂ b, and the total thickness T ₂ of the skin layer 2 a and the skin layer ₂ b with respect to the thickness T ₁ of the core layer 1. The ratio T ₂ / T ₁ is 0.1 or more and 1.0 or less.

  In the stretchable material 10, both the skin layer 2a and the skin layer 2b are configured to include a resin material that forms a microphase separation structure. The skin layer 2a and the skin layer 2b can be uniformly plastically deformed by a stretching process because the phase structure that is easily plastically deformed is densely distributed throughout the skin layer. For this reason, the expansion-contraction part formed from the expansion-contraction material 10 becomes the thing excellent in the elongation uniformity at the time of expansion | extension.

  The stretchable material 10 has a substantially rectangular shape in a plan view, and functions as a stretchable member by being stretched in the longitudinal direction. The resin materials constituting the skin layer 2a and the skin layer 2b have substantially the same composition. Moreover, the tensile yield stress in the longitudinal direction of the skin layer 2a and the skin layer 2b is substantially the same. By stretching the stretchable material 10 in the longitudinal direction, the skin layer 2a and the skin layer 2b are plastically deformed to form a stretchable portion.

  The tensile stress at 300% elongation in the longitudinal direction of the stretchable material 10 is 110% or less of the tensile yield stress of the skin layer 2a and the tensile yield stress of the skin layer 2b. Thereby, even if it performs about 200% of elongation time practically useful, the shape holding | maintenance part mentioned later can maintain the original shape, and favorable bondability with another member is maintained.

  FIG. 3A and FIG. 3B are diagrams for explaining one aspect of the stretching process of the elastic material. In this aspect, the elastic material 10 is clamped by the rectangular holding members in the region 3a at the center in the longitudinal direction of the elastic material 10 and the terminal region 3b and the region 3c, the region 3a is fixed, and the region 3b and the region 3c are fixed. By stretching along the longitudinal direction, the region 3a and the region 3b and the region 3a and the region 3c are stretched.

  FIG. 3B shows the state of the stretchable material at the time of stretching, and the shape holding portions 4a, 4b, and 4c corresponding to the regions 3a, 3b, and 3c sandwiched by the sandwiching members maintain the form of the stretchable material 10. In the extending portions 5a and 5b between the region 3a and the region 3b and between the region 3a and the region 3c, the stretchable material 10 is stretched, and the skin layer of the stretchable material 10 is plastically deformed.

  When the stretchable material 10 is stretched 200% in the longitudinal direction, the contraction rate in the width direction perpendicular to the longitudinal direction is 30% or less. The “shrinkage ratio” is the ratio (L2−L1) / L2 of the width contracted by expansion (the value obtained by subtracting the minimum width during expansion from the width before expansion (L2−L1)) with respect to the width L2 before expansion. Indicates. “At 200% extension” indicates that the length L4 at the time of extension is 200% with respect to the initial length L3 of the part to be extended.

  FIG. 4 is a plan view showing one aspect of the stretchable member according to the present embodiment. The elastic member 20 includes a shape holding part 14 in which the layer structure of the elastic material 10 is maintained, and an elastic part 15 formed between the shape holding parts 14. When the stretchable member 20 is pulled in the longitudinal direction, the stretchable portion 15 expands, and the shape holding portion 14 retains its shape. For this reason, in the elastic member 20, good adhesion to other members can be obtained by joining the other members with the shape holding portion 14.

  FIG. 5 is a diagram illustrating a relationship between the stretch rate and the tensile stress of the stretchable material and the stretchable member according to one aspect. In FIG. 5, a line 51 indicates the relationship between the stretch rate of the stretchable material and the tensile stress. A line 52 indicates the relationship between the expansion rate and the tensile stress when the elastic member formed by extending the elastic material by 300% is extended. 5 corresponds to the tensile yield point of the skin layer, and the tensile stress at the point 53 corresponds to the tensile yield stress of the skin layer. A point 54 in FIG. 5 is a point when the stretchable material is stretched by 300%, and the tensile stress at the point 54 may be 110% or less of the tensile stress at the point 53.

[Second Embodiment]
A preferred second embodiment of the stretchable material, stretchable member and clothing product according to the present invention will be described below.

(Elastic material)
The elastic material according to the present embodiment includes a core layer containing an elastomer and a skin layer having a higher 10% tensile stress than the core layer in at least one direction.

  The stretchable material can form a stretchable member having a stretchable part by plastically deforming at least a part of the skin layer by a stretching process. In forming the stretchable member, only a part of the skin layer may be plastically deformed to provide a portion (shape holding portion) in which the layer structure of the stretchable material is maintained. The stretchable member having the shape holding part can ensure good bondability with other members in the shape holding part.

  In this embodiment, the stretchable material may have a layer structure (skin layer / core layer / skin layer) in which skin layers are laminated on both main surfaces of the core layer. In such a stretchable material, the tensile stress on both main surfaces becomes more uniform, and when a stretchable portion is provided, warpage due to nonuniform shrinkage is prevented. Further, in such an elastic material, the skin layers come into contact with each other when wound in a roll shape, and therefore between the elastic materials (for example, between the skin layer and the core layer wound on the skin layer). Is prevented, and the workability during unwinding and the storage stability of the stretchable material are improved. However, the layer structure of the stretchable material is not limited to the above. For example, the elastic material may have a layer structure (core layer / skin layer) in which a skin layer is laminated only on one side of the core layer, and the core layer is laminated on both main surfaces of the skin layer. It may have a layer structure (core layer / skin layer / core layer).

  In the present embodiment, the core layer and the skin layer may be directly bonded or indirectly bonded via an intermediate layer. The intermediate layer may be, for example, an adhesive layer that joins a modification layer containing a coloring material, a core layer, and a skin layer. The bonding mode between the core layer and the skin layer is not particularly limited. For example, the resin materials constituting the core layer and the skin layer may be fused and bonded, and the bonding is interposed between the core layer and the skin layer. You may adhere | attach by the agent layer.

In the present embodiment, the thickness T ₁ of the core layer may be a thickness T ₂ or more skin layers. In such a stretchable material, narrowing (necking) of the stretchable portion at the time of elongation tends to be suppressed. That is, in the stretchable member obtained from such a stretchable material, necking at the time of extension is reduced, so that local action of the tightening force is prevented, and excellent comfort when worn can be realized.

  Further, by reducing the thickness of the skin layer, it is possible to further reduce the strain of the stretchable part when the stretched state is maintained for a long time. In addition, when there is no skin layer, it is expected that the strain of the stretchable part can be reduced, but it is desired that there is a skin layer from the viewpoint of productivity, workability, weather resistance, storage stability, There is an increasing expectation for a stretchable material having a skin layer and less strain at the stretchable portion.

In the present embodiment, the ratio T ₂ / T ₁ of the thickness T ₂ of the skin layer to the thickness T ₁ of the core layer may be 0.01 or more and 1.0 or less, and is 0.1 or more and 0.5 or less. It's okay. According to such an elastic material, since the elastic member in which necking at the time of extension is more significantly suppressed is obtained, it is possible to provide a clothing product that is further excellent in comfort at the time of wearing.

Further, from the viewpoint of further reducing the strain of the stretchable part when the stretched state is maintained for a long time, the ratio T ₂ / T ₁ is preferably 0.3 or less, more preferably 0.25 or less, and still more preferably. It may be 0.2 or less.

Incidentally, when a plurality of the skin layer is laminated to the stretchable material, the thickness T ₂ of the skin layer exhibits a total thickness of each skin layer. Further, when a plurality of the core layer is laminated stretchable material, the thickness T ₁ of the core layer exhibits a total thickness of each core layer.

  Further, the stretchable material may have a tensile stress at 300% elongation in one direction of 110% or less of the tensile yield stress of the skin layer in the same direction. When the stretchable member has a stretchable part and a shape retaining part, if the tensile stress required for stretching is significantly greater than the tensile yield stress of the skin layer, the shape retaining part cannot be plastically deformed during stretching, and the original shape cannot be maintained repeatedly. May interfere with the use of. If the tensile stress at the time of 300% elongation does not greatly exceed the tensile yield stress of the skin layer, the shape holding part can maintain the original shape even if the practically useful elongation of about 200% is performed. Bondability is further improved. In such a stretchable material, the stretchable portion may be formed by stretching in a direction in which the tensile stress at 300% elongation and the tensile yield stress of the skin layer satisfy the above relationship.

  In the present embodiment, the tensile stress at 300% elongation of the stretchable material is measured at a test piece width of 25 mm, a chuck interval of 50 mm, and a test speed of 300 mm / min in accordance with JIS K7127. Further, the tensile yield stress of the skin layer is measured according to JIS K 7127 at a test piece width of 25 mm, a chuck interval of 50 mm, and a test speed of 300 mm / min. When the stretchable material has a plurality of skin layers, the maximum tensile yield stress of each skin layer is referred to as “tensile yield stress of skin layer”. The tensile yield stress of the skin layer may be measured by peeling only the skin layer from the elastic material, and may be measured using a test piece equivalent to the skin layer. As a simple discrimination method, in the tensile stress test of the stretchable material, the yield point at which all skin layers are plastically deformed can be regarded as the tensile yield stress of the skin layers.

  In this embodiment, when the stretchable material is stretched by 200% in at least one direction, the shrinkage rate in the width direction orthogonal to the stretch direction (ratio of the width shrunk by stretching to the width before stretching) is 50%. Or less, preferably 30% or less, more preferably 25% or less, more preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. When the elastic member has the expansion / contraction part and the shape holding part, the width of the shape holding part is maintained at a constant width, and the expansion / contraction part is narrowed according to the extension. Here, when the width of the expansion / contraction part becomes extremely narrow at the time of extension, the difference between the width of the shape holding part and the width of the expansion / contraction part becomes large. In such a case, particularly when applied to a clothing product that is in close contact with the skin, the wearability may be reduced, or the tightening force may easily act locally, thereby impairing comfort during wearing. When the shrinkage ratio in the width direction orthogonal to the extension direction at 200% extension is 30% or less, the degree of narrowing of the stretchable part at the time of extension is sufficiently small, and the wearability and comfort at wearing are sufficient. Can be secured. In such a stretchable material, the stretchable portion may be formed by stretching in a direction in which the shrinkage rate falls within the above range. In addition, when the remarkable change does not arise in the comfort at the time of wearing even by narrowing by extension, the stretchable material does not necessarily have a shrinkage rate in the above range.

  In the present embodiment, the shrinkage ratio in the width direction orthogonal to the extension direction at the time of 200% extension indicates a value measured by the following method. First, a rectangular test piece (width 50 mm, length 50 mm or more) having a long side and a short side along the extending direction and the width direction perpendicular thereto is prepared. The both ends in the extending direction of the test piece are sandwiched so that the length of the extending portion is 50 mm, and extended by 200% in the extending direction. When the initial width of the test piece is L1, and the minimum width of the test piece at 200% stretching is L2, the shrinkage rate (%) is calculated by (L2 / L1) × 100.

  In this embodiment, when the stretchable material is stretched by 300% in one direction to form a stretchable portion, the stretchable portion is stretched by 160% in the same direction, and strain by an elongation test that is held at 40 ° C. for 1 hour is 25%. Or less, more preferably 22% or less, and even more preferably 20% or less. In this case, even when the stretchable part is held in the stretched state, it is difficult for the strain to remain. Therefore, when applied to a clothing product, excellent fit at the time of wearing can be sufficiently maintained even by repeated use.

  In addition, the distortion | strain by an elongation test means that the length of the expansion-contraction part before an expansion | extension test is 100%, and the length of the expansion / contraction part after an expansion | extension test is 125% or less.

  Below, each layer which comprises the elastic material which concerns on this embodiment is explained in full detail.

<Core layer>
The elastic material according to this embodiment includes a core layer containing an elastomer. A core layer is a layer which bears the elastic function of an elastic member, The composition etc. may be selected so that it may have desired rubber elasticity.

  The elastomer contained in the core layer is a material having rubber elasticity, and the core layer has a 10% tensile stress lower than that of the skin layer. In this embodiment, the 10% tensile stress is also called 10% Modulus, and is a force per unit area necessary for 10% elongation, and is measured according to JIS K 6251.

  The 10% tensile stress of the core layer may be, for example, 0.5 MPa or less, 0.3 MPa or less, or 0.1 MPa or less. Thereby, since it stretches following small stress, the elastic member excellent in handleability is obtained. The core layer may have a 10% tensile stress in the above range in at least one direction. The core layer may have a 10% tensile stress in the above range in the stretching direction of the elastic material.

  The 300% tensile stress of the core layer may be 4 MPa or less, for example, or 2 MPa or less. Thereby, since it stretches following small stress, the elastic member excellent in handleability is obtained. The 300% tensile stress of the core layer may be, for example, 1 MPa or more, and preferably 1.5 MPa or more. Thereby, it is suppressed that it extends indefinitely practically. The core layer may have 300% tensile stress in the above range in at least one direction. The core layer may have a 300% tensile stress in the above range in the stretching direction of the stretchable material.

The core layer thickness T ₁ may be, for example, 10 μm or more, and is preferably 15 μm or more. Further, the thickness T _{1 of the} core layer may be, for example, 100 μm or less, 50 μm or less, or 35 μm or less from the viewpoint of reducing the material cost while obtaining a sufficient effect.

  The core layer may be made of a resin material containing an elastomer (hereinafter also referred to as “resin material (A)”). The type of elastomer is, for example, styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene butadiene rubber, hydrogenated or partially. Examples include hydrogenated SIS, hydrogenated or partially hydrogenated SBS, polyurethane, ethylene copolymer (eg, ethylene vinyl acetate, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer), propylene oxide (PO), and the like. .

  In one embodiment, the elastomer may contain a branched polymer. As a result, the stretchable portion of the stretchable member is less likely to remain strained even when worn for a long time. Moreover, it becomes easy to restrain the distortion by the above-mentioned extension test to the suitable range of 25% or less because an elastomer has a branched polymer. That is, according to this aspect, an elastic member that can maintain excellent fit even when worn for a long time is obtained.

  The branched polymer is a polymer having a branched structure in the molecule, and may be, for example, a graft polymer, a star polymer, a dendrimer, or the like.

  The resin material (A) constituting the core layer may contain components other than those described above. For example, the resin material (A) is made of a stiffening agent (eg, polyvinyl styrene, polystyrene, poly α-methyl styrene, polyester, epoxy resin, polyolefin, coumarone-indene resin), a viscosity reducing agent, a plasticizer, a tackifier ( For example, aliphatic hydrocarbon tackifier, aromatic hydrocarbon tackifier, terpene resin tackifier, hydrogenated terpene resin tackifier), dye, pigment, antioxidant, antistatic agent, adhesive, tack An inhibitor, slip agent, heat stabilizer, light stabilizer, foaming agent, glass bubble, starch, metal salt, microfiber, and the like may be included.

<Skin layer>
The elastic material according to the present embodiment includes a skin layer having a 10% tensile stress higher than that of the core layer in at least one direction. The skin layer has a function of protecting the core layer in the stretchable material, and is plastically deformed by a stretching process when the stretchable member is manufactured. At this time, the core layer is elastically deformed, and only the skin layer is plastically deformed, so that the stretched portion can be used as the stretchable portion of the stretchable member. The skin layer may have a function of maintaining the shape of the shape holding portion in the stretchable member.

  The 10% tensile stress of the skin layer may be 1 MPa or more, for example, or 2 MPa or more. Thereby, it does not deform | transform with a small tensile stress, and the handleability of an elastic material becomes favorable. Further, the 10% tensile stress of the skin layer may be, for example, 15 MPa or less, or 10 MPa or less. Thereby, the stress for plastically deforming the skin layer can be reduced, and workability is improved. The skin layer may have a 10% tensile stress in the above range in at least one direction. The skin layer may have a 10% tensile stress in the above range in the stretching direction of the elastic material. In this embodiment, the 10% tensile stress of the skin layer is measured in accordance with JIS K 6251.

  The tensile yield stress of the skin layer may be, for example, 2 N / 25 mm or more, preferably 2.5 N / 25 mm or more, more preferably 3 N / 25 mm or more. Further, the tensile yield stress of the skin layer may be, for example, 10 N / 25 mm or less, and preferably 7 N / 25 mm or less. The skin layer may have a tensile yield stress in the above range in at least one direction. Moreover, the skin layer may have the tensile yield stress of the said range in the extending | stretching direction of an elastic material. The tensile yield stress of the skin layer is measured according to JIS K 7127 at a test piece width of 25 mm, a chuck interval of 50 mm, and a test speed of 300 mm / min.

  The tensile yield strain of the skin layer may be, for example, 20% or less, and preferably 15% or less. The skin layer may have a tensile yield strain in the above range in at least one direction. The skin layer may have a tensile yield strain in the above range in the stretching direction of the elastic material. In this embodiment, the tensile yield strain of the skin layer is measured according to JIS K 7127 at a test piece width of 25 mm, a chuck interval of 50 mm, and a test speed of 300 mm / min.

The thickness T _{2 of the} skin layer may be, for example, 2 μm or more, and preferably 5 μm or more from the viewpoints that the above-described preferable tensile properties can be easily obtained and that the production becomes easy. The thickness T ₂ of the skin layer, from the viewpoint of distortion can be further reduced in the expansion unit upon maintaining the extended state for a long time, may be for example 30μm or less and preferably 20μm or less.

  In one embodiment, the resin material constituting the skin layer (hereinafter also referred to as “resin material (B)”) may form a microphase separation structure. In such a skin layer, since a phase structure that is easily plastically deformed is densely distributed throughout the skin layer, it can be uniformly plastically deformed by a stretching process. Thereby, the stretchable part formed becomes excellent in the uniformity of elongation at the time of extension. Further, since the skin layer has a micro phase separation structure, necking at the time of extension is more remarkably suppressed, and an elastic member that is further excellent in comfort at the time of wearing is realized.

  Further, when such a skin layer is used, the elongation becomes uniform even at a relatively low degree of stretching such as 100% stretching, and therefore any stretching such as 100%, 150%, 200%, 250%, 300%, etc. The stretchable material can be stretched at a degree. Note that when the degree of stretching at the time of the stretching process is different, mechanical properties such as elasticity and tensile stress of the formed stretchable part are changed. That is, in this aspect, the stretchable part having different characteristics can be formed from the same stretchable material by changing the stretching degree during the stretching process. For this reason, for example, even when the required characteristics differ depending on the part of the clothing product, the same stretchable material can be applied to each part by adjusting the degree of stretching according to the desired characteristic.

  The microphase separation structure formed by the resin material (B) may be, for example, a lamellar structure, a gyroid structure, a cylinder structure, a BCC structure, or the like. The microphase-separated structure may be formed by a block copolymer, for example, or may be formed by a polymer blend.

  The resin material (B) may contain a block copolymer. The block copolymer is preferably a block copolymer that forms a microphase-separated structure. Examples of the block copolymer include those containing, as elements, olefins such as ethylene, propylene, and butylene, esters such as ethylene terephthalate, and styrenes such as styrene.

  The resin material (B) may form a microphase separation structure by a polymer blend containing two or more kinds of polymers. Examples of the polymer contained in the resin material (B) include polypropylene, polyethylene, polybutylene, polyethylene terephthalate, and polystyrene.

  In another embodiment, the resin material (B) may form a uniform layer structure without forming a microphase separation structure. Thereby, in the expansion-contraction part of an elastic member, the distortion by long-time wearing can be suppressed more notably. Moreover, it becomes easy to restrain the distortion by the above-mentioned extension test to the suitable range of 25% or less because a skin layer has a uniform layer structure. That is, according to this aspect, as compared with the case where the resin material (B) forms a microphase-separated structure, the distortion of the stretchable part due to wearing for a long time is further suppressed, and excellent fit is maintained for a longer period. it can.

  The resin material (B) may contain a homopolymer. According to the resin material (B) containing a homopolymer, a skin layer having the above-described uniform layer structure can be easily obtained.

  Examples of the homopolymer include polypropylene, polyethylene, polybutylene and the like.

  The resin material (B) may contain components other than those described above. For example, mineral oil extenders, antistatic agents, pigments, dyes, antiblocking agents, starches, metal salts, stabilizers and the like may be included.

  The manufacturing method of the elastic material according to the present embodiment is not particularly limited, and for example, a general multilayer film forming technique using a resin material can be applied.

  In the elastic material according to the present embodiment, for example, the core layer and the skin layer are integrally formed by simultaneous extrusion molding of the resin material (A) constituting the core layer and the resin material (B) constituting the skin layer. It may be. The conditions for the coextrusion molding may be appropriately adjusted according to the composition of the resin material (A) and the resin material (B). The stretchable material according to the present embodiment may be manufactured by molding and laminating the A layer containing the resin material (A) and the B layer containing the resin material (B), respectively.

(Elastic member)
The stretchable member according to the present embodiment includes a stretchable portion (also referred to as an activation portion) having a structure in which the skin layer of the stretchable material is plastically deformed. The stretchable member according to the present embodiment may further include a shape holding portion (also referred to as an unactivated portion) in which the layer structure of the stretchable material is maintained.

  The stretchable member according to this embodiment can be suitably used as an elastic web applied to clothing products and the like because the stretchable portion functions as a rubber elastic body. In addition, the stretchable member according to the present embodiment can be bonded to another member in the shape holding portion, thereby obtaining good bondability with the other member.

  If the stretchable member is distorted by holding the stretchable part in an extended state for a long time, the stretchable member may not be able to maintain excellent fit when worn. Since the stretchable member according to the present embodiment is formed from the above-described stretchable material, the strain of the stretchable portion is sufficiently suppressed, and excellent fit can be maintained for a long time. Moreover, in the aspect in which the skin layer of the stretchable material has a uniform layer structure, the distortion of the stretchable portion is more remarkably suppressed, and the change in fit can be significantly reduced even by repeated use.

  In addition, if the stretchable member has an uneven elongation when stretched, the wearability and the comfort when worn may be impaired. In this embodiment, in the aspect in which the skin layer has a microphase separation structure, the stretch layer can have excellent elongation uniformity.

  In addition, when the stretchable member is applied to a clothing product that is in close contact with the skin, if the width of the stretchable portion when stretched becomes small, the tightening force tends to act locally, which may impair the comfort when worn. is there. In the present embodiment, in the aspect in which the skin layer has a microphase separation structure, the degree of narrowing of the stretchable part when stretched is sufficiently small, and the wearability and the comfort when worn can be sufficiently secured.

  In the elastic member, deformation due to repeated use can be a problem when applied to clothing products. Since the stretchable member according to the present embodiment is formed from the above-described stretchable material, the shape holding portion can maintain the original shape even after repeated use, and good bondability with other members can be maintained.

  The stretchable part has a structure in which the skin layer of the stretchable material is plastically deformed. In other words, the stretchable part may include a core layer and a plastically deformed skin layer. In the stretchable part, the plastically deformed skin layer may exist as a continuous layer, or may be divided by stretching.

  The shape holding part has a layer structure of stretchable material. That is, the shape holding part may include a core layer and a skin layer. It can also be said that the shape holding portion is an unstretched portion of the stretchable material.

  The stretchable member is manufactured by subjecting a stretchable material to a stretching treatment depending on the intended use. The use of the elastic member is not particularly limited, and may be used for clothing, for example. More specifically, the elastic member may be, for example, a disposable diaper, an adult incontinence pad, a shower cap, a surgical gown, a hat and booth, a disposable pajamas, a competition shoulder, a clean room garment, a hat head hand or a visor. Etc., and used for an ankle band (for example, a panties cows protector), a wrist band, a rubber pan, a wet suit and the like.

  The method for producing an elastic member includes a step of stretching at least a part of the elastic material and plastically deforming at least a part of the skin layer (also referred to as a step of activating at least a part of the elastic material). It's okay. The stretchable part is formed by stretching the stretchable material until the skin layer is plastically deformed. Plastic deformation is generally achieved by stretching beyond the tensile yield strain of the skin layer.

  In the manufacturing method of the elastic member, the elastic part and the shape holding part may be formed by plastically deforming only a part of the skin layer.

  The stretching method of the elastic material is not particularly limited. For example, by sandwiching and stretching both ends of the stretchable material with a predetermined width, two shape holding portions with a predetermined width (unstretched portions sandwiched) and a stretchable portion formed between the shape holding portions, The elastic member provided is formed.

  The temperature condition at the time of extending | stretching an elastic material is not specifically limited, Room temperature may be sufficient. The stretch ratio of the stretchable material only needs to be equal to or higher than the tensile yield strain of the skin layer, and may be equal to or higher than the stretch ratio practically assumed. Further, as described above, since the mechanical properties of the stretchable part can be changed depending on the stretch ratio, the stretch ratio may be set according to desired characteristics.

  Next, a preferred aspect of the present embodiment will be described with reference to the drawings.

  FIG. 6 is a plan view showing an aspect of the stretchable material according to the present embodiment, and FIG. 7 is an enlarged cross-sectional view taken along line II-II in FIG. As shown in FIGS. 6 and 7, the stretchable material 10 includes a core layer 1 and a skin layer 2 a and a skin layer 2 b provided on both main surfaces of the core layer 1, respectively.

In the stretchable material 10, the thickness T ₁ of the core layer 1 is equal to or greater than the total thickness T ₂ of the skin layer 2 a and the skin layer ₂ b, and the total thickness T ₂ of the skin layer 2 a and the skin layer ₂ b with respect to the thickness T ₁ of the core layer 1. The ratio T ₂ / T ₁ is 0.1 or more and 1.0 or less.

  In the elastic material 10, the core layer is made of a resin material containing a branched polymer. Moreover, the skin layer 2a and the skin layer 2b are comprised with the resin material containing a homopolymer. For this reason, the stretchable part formed from the stretchable material 10 has little distortion even when the stretched state is maintained for a long time, and can maintain excellent fit for a long time when applied to clothing products.

  The stretchable material 10 has a substantially rectangular shape in a plan view, and functions as a stretchable member by being stretched in the longitudinal direction. The resin materials constituting the skin layer 2a and the skin layer 2b have substantially the same composition. Moreover, the tensile yield stress in the longitudinal direction of the skin layer 2a and the skin layer 2b is substantially the same. By stretching the stretchable material 10 in the longitudinal direction, the skin layer 2a and the skin layer 2b are plastically deformed to form a stretchable portion.

  The tensile stress at 300% elongation in the longitudinal direction of the stretchable material 10 is 110% or less of the tensile yield stress of the skin layer 2a and the tensile yield stress of the skin layer 2b. Thereby, even if it performs about 200% of elongation time practically useful, the shape holding | maintenance part mentioned later can maintain the original shape, and favorable bondability with another member is maintained.

  Fig.8 (a) and FIG.8 (b) are the figures for demonstrating the one aspect | mode of the extending | stretching process of an elastic material. In this aspect, the elastic material 10 is clamped by the rectangular holding members in the region 3a at the center in the longitudinal direction of the elastic material 10 and the terminal region 3b and the region 3c, the region 3a is fixed, and the region 3b and the region 3c are fixed. By stretching along the longitudinal direction, the region 3a and the region 3b and the region 3a and the region 3c are stretched.

  FIG. 8B shows the state of the stretchable material at the time of stretching, and the shape holding portions 4a, 4b and 4c corresponding to the regions 3a, 3b and 3c sandwiched by the sandwiching members maintain the form of the stretchable material 10. In the extending portions 5a and 5b between the region 3a and the region 3b and between the region 3a and the region 3c, the stretchable material 10 is stretched, and the skin layer of the stretchable material 10 is plastically deformed.

  When stretched 200% in the longitudinal direction, the shrinkage ratio in the width direction orthogonal to the longitudinal direction is measured. The “shrinkage ratio” indicates a ratio (L2−L1) / L2 of a width contracted by expansion (a value obtained by subtracting a minimum width during expansion (L2−L1)) from the width L2 before expansion. . “At 200% extension” indicates that the length L4 at the time of extension is 200% with respect to the initial length L3 of the part to be extended.

  FIG. 9 is a plan view showing an aspect of the stretchable member according to the present embodiment. The elastic member 20 includes a shape holding part 14 in which the layer structure of the elastic material 10 is maintained, and an elastic part 15 formed between the shape holding parts 14. When the stretchable member 20 is pulled in the longitudinal direction, the stretchable portion 15 expands, and the shape holding portion 14 retains its shape. For this reason, in the elastic member 20, good adhesion to other members can be obtained by joining the other members with the shape holding portion 14.

  FIG. 10A, FIG. 10B, and FIG. 10C are diagrams for explaining the extension test of the stretchable part. FIG. 10A shows the state of the test piece before the extension test. The test piece 30 before the extension test is a stretchable part formed by stretching the stretchable material 10 by 300% (the length L4 when stretched is 300% with respect to the length L3 before stretched in FIG. 9). In the test piece 30, the central portion is the extended portion 15 a and both ends are the sandwiching portions 16 a and 16 b. In the elongation test, as shown in FIG. 10B, the stretched portion 15a is stretched 160% (the length L6 when stretched is 300% with respect to the length L5 before stretching) at 40 ° C. for 1 hour. Hold. “Strain by extension test” indicates the elongation ratio (100 × (L5−L7) / L5) of the length L7 of the stretched portion 15b after the stretch test with respect to the length L5 of the stretched portion 15a before the stretch test.

  In the stretchable member 20 shown in FIG. 9, the strain by the stretch test of the stretchable portion 15 may be 25% or less, preferably 22% or less, more preferably 20% or less. Thereby, when applied to clothing products, excellent fit is sufficiently maintained even when worn for a long time.

  FIG. 11 is a diagram illustrating an example of the relationship between the elongation rate and tensile stress of the stretchable material and the stretchable member according to one aspect. In FIG. 11, the line 51 shows the relationship between the elongation rate of the elastic material and the tensile stress. A line 52 indicates the relationship between the elongation rate and the tensile stress when the elastic member formed by extending the elastic material by 300% is extended. The point 53 in FIG. 11 corresponds to the tensile yield point of the skin layer, and the tensile stress at the point 53 corresponds to the tensile yield stress of the skin layer. A point 54 in FIG. 11 is a point when the stretchable material is stretched by 300%, and the tensile stress at the point 54 may be 110% or less of the tensile stress at the point 53.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to an Example.

[Examples mainly related to the first embodiment]
(Example X-1)
As a resin material (X-A-1) constituting the core layer, 72 parts by weight of “Quintac 3390” (manufactured by Zeon Corporation, styrene-isoprene-styrene block copolymer), and “Quintac 3620” (manufactured by Zeon Corporation, A mixed material of 25 parts by mass of styrene-isoprene-styrene block copolymer) and 3 parts by mass of “PS-M AZ 12N8613” (manufactured by Dainichi Seika Kogyo Co., Ltd., styrene-isoprene-styrene block copolymer base white masterbatch) was used. . The white masterbatch is added to give a white color. As a resin material (X-B) constituting the skin layer, “Novatec PP BC2E” (manufactured by Nippon Polypro Co., Ltd., ethylene propylene block copolymer) was used.

A first skin layer made of 3.5 g of a resin material (X-B), a core layer made of 28 g of a resin material (X-A-1), and a resin by a coextruded film manufacturing system manufactured by Sumitomo Heavy Industries Modern Co., Ltd. A tape-like stretchable material (X-a-1) having a width of 5 cm was produced in which a second skin layer made of 3.5 g of the material (X-B) was laminated in this order. In the obtained elastic material (X-a-1), the first skin layer has a thickness of 3.8 μm, the core layer has a thickness of 30.4 μm, and the second skin layer has a thickness of 3.8 μm. The ratio T ₂ / T ₁ of the total thickness T ₂ of the skin layer to the thickness T ₁ of the layer was 0.25. From the stretchable material (X-a-1), a test piece having a width of 5 cm and a length of 7 cm (stretching part 5 cm, sandwiching part 1 cm at both ends) was obtained, and the following stretching tests 1 to 3 were performed.

<Extension test 1>
Both ends of the test piece were sandwiched and stretched to 350% in the longitudinal direction. At the time of 100%, 200%, 300% and 350% stretching, the minimum width of the stretched portion was measured while maintaining the stretched state. From the measured minimum width and initial width (5 cm), the shrinkage rate at each extension was determined.

<Extension test 2>
One side of the test piece was marked at 1 mm intervals and stretched to 300% in the longitudinal direction. At the time of 100%, 200% and 300% stretching, the distance between the marks was measured while maintaining the stretched state, and the average value and standard deviation of each distance were obtained.

<Extension test 3>
The relationship between the tensile stress up to 300% of the test piece and the elongation rate was determined using a Tensilon universal material testing machine (RTG-1225, manufactured by A & D Co., Ltd.), and was graphed as shown in FIG. From the obtained graph, the tensile yield stress of the test piece and the tensile stress at 300% elongation were determined.

  From the results of the stretch tests 1 to 3, the stretchable material (X-a-1) has a sufficiently low shrinkage rate when stretched, excellent stretch uniformity, and a tensile stress when stretched by 300%. It was confirmed that it was 110% or less of the stress. Moreover, the graph obtained by the extending | stretching test 3 was as showing in FIG.

(Example X-2)
The amount of the resin material (X-B) constituting the first skin layer and the second skin layer was changed to 5.25 g, respectively, and the amount of the resin material (X-A-1) constituting the core layer was changed to 24. A tape-like stretchable material (X-a-2) having a width of 5 cm was obtained in the same manner as in Example X-1, except that it was changed to 0.5 g.

In the obtained elastic material (X-a-2), the thickness of the first skin layer is 5.7 μm, the thickness of the core layer is 26.6 μm, the thickness of the second skin layer is 5.7 μm, the ratio _T 2 / _{T 1} of the total thickness _{T 2} of the skin layer to the thickness _{T 1} of the layer was about 0.43. From the stretchable material (X-a-2), a test piece having a width of 5 cm and a length of 7 cm (stretching part 5 cm, sandwiching part 1 cm at both ends) was obtained, and the above stretching tests 1 to 3 were performed.

  From the results of the stretching tests 1 to 3, the stretchable material (X-a-2) has a sufficiently low shrinkage rate when stretched, excellent stretch uniformity, and a tensile stress when stretched by 300%. It was confirmed to be 110% or less of the stress.

(Example X-3)
The amount of the resin material (X-B) constituting the first skin layer and the second skin layer was changed to 2.625 g, and the amount of the resin material (X-A-1) constituting the core layer was 29. A tape-shaped stretchable material (Xa-3) having a width of 5 cm was obtained in the same manner as in Example X-1, except that the amount was changed to .75 g.

In the obtained elastic material (X-a-3), the first skin layer has a thickness of 2.9 μm, the core layer has a thickness of 32.2 μm, and the second skin layer has a thickness of 2.9 μm. the ratio _T 2 / _{T 1} of the total thickness _{T 2} of the skin layer to the thickness _{T 1} of the layer was about 0.18. From the stretchable material (X-a-3), a test piece having a width of 5 cm and a length of 7 cm (stretched portion 5 cm, sandwiched portions 1 cm at both ends) was obtained, and the stretching tests 1 to 3 were performed.

  From the results of the stretching tests 1 to 3, the stretchable material (X-a-3) has a sufficiently low shrinkage rate when stretched, is excellent in stretch uniformity, and the tensile stress when stretched by 300% is the tensile yield of the skin layer. It was confirmed to be 110% or less of the stress.

(Example X-4)
As a resin material (X-A-2) constituting the core layer, 47 parts by weight of “Quintac 3390” (manufactured by ZEON Corporation, styrene-isoprene-styrene block copolymer) and “Quintac 3620” (manufactured by ZEON Corporation, A mixed material of 50 parts by mass of styrene-isoprene-styrene block copolymer) and 3 parts by mass of “PS-M AZ 12N8613” (manufactured by Daiichi Seika Kogyo Co., Ltd., styrene-isoprene-styrene block copolymer base white masterbatch) is used. It was. As a resin material (X-B) constituting the skin layer, “Novatec PP BC2E” (manufactured by Nippon Polypro Co., Ltd., ethylene propylene block copolymer) was used.

In a co-extruded film manufacturing system manufactured by Sumitomo Heavy Industries Modern Co., Ltd., a first skin layer made of 5.25 g of resin material (X-B), a core layer made of 24.5 g of resin material (X-A-2), And the 2nd skin layer which consists of resin material (XB) 5.25g was laminated | stacked in this order, and the tape-shaped elastic material (Xa-4) of width 5cm was produced. In the obtained elastic material (X-a-4), the first skin layer has a thickness of 5.7 μm, the core layer has a thickness of 26.6 μm, and the second skin layer has a thickness of 5.7 μm. the ratio _T 2 / _{T 1} of the total thickness _{T 2} of the skin layer to the thickness _{T 1} of the layer was about 0.43. From the stretchable material (Xa-4), a test piece having a width of 5 cm and a length of 7 cm (stretched portion 5 cm, sandwiched portions 1 cm at both ends) was obtained, and the stretching tests 1 to 3 were performed.

  From the results of the stretching tests 1 to 3, the stretchable material (Xa-4) has a sufficiently low shrinkage rate when stretched, excellent stretch uniformity, and the tensile stress when stretched by 300% is the tensile yield of the skin layer. It was confirmed that it was 110% or less of the stress.

(Example X-5)
The amount of the resin material (X-B) constituting the first skin layer and the second skin layer was changed to 2.625 g, and the amount of the resin material (X-A-2) constituting the core layer was 29. A tape-like stretchable material (Xa-5) having a width of 5 cm was obtained in the same manner as in Example X-4 except that the amount was changed to .75 g.

In the obtained elastic material (X-a-5), the thickness of the first skin layer is 2.9 μm, the thickness of the core layer is 32.2 μm, the thickness of the second skin layer is 2.9 μm, the ratio _T 2 / _{T 1} of the total thickness _{T 2} of the skin layer to the thickness _{T 1} of the layer was about 0.18. From the stretchable material (Xa-5), a test piece having a width of 5 cm and a length of 7 cm (stretched portion 5 cm, sandwiched portions 1 cm at both ends) was obtained, and the stretching tests 1 to 3 were performed.

  From the results of the stretching tests 1 to 3, the stretchable material (Xa-5) has a sufficiently low shrinkage rate when stretched, excellent stretch uniformity, and a tensile stress when stretched by 300%. It was confirmed to be 110% or less of the stress.

(Example X-6)
The amount of the resin material (X-B) constituting the first skin layer and the second skin layer is changed to 3.5 g, and the amount of the resin material (X-A-2) constituting the core layer is 28 g. A tape-shaped stretchable material (Xa-6) having a width of 5 cm was obtained in the same manner as in Example X-4, except that the change was made.

In the obtained stretchable material (Xa-6), the thickness of the first skin layer is 3.8 μm, the thickness of the core layer is 30.2 μm, the thickness of the second skin layer is 3.8 μm, The ratio T ₂ / T ₁ of the total thickness T ₂ of the skin layer to the thickness T ₁ of the layer was 0.25. From the stretchable material (Xa-6), a test piece having a width of 5 cm and a length of 7 cm (stretched portion 5 cm, sandwiched portion 1 cm at both ends) was obtained, and the stretching tests 1 to 3 were performed.

  From the results of the stretching tests 1 to 3, the stretchable material (Xa-6) has a sufficiently low shrinkage rate when stretched, excellent stretch uniformity, and the tensile stress when stretched by 300% is the tensile yield of the skin layer. It was confirmed to be 110% or less of the stress.

(Example X-7)
The amount of the resin material (X-B) constituting the first skin layer and the second skin layer was changed to 7.0 g, and the amount of the resin material (X-A-2) constituting the core layer was 21 g. A tape-shaped stretchable material (Xa-7) having a width of 5 cm was obtained in the same manner as in Example X-4, except that the change was made.

In the obtained stretchable material (Xa-7), the thickness of the first skin layer was 7.6 μm, the thickness of the core layer was 22.8 μm, the thickness of the second skin layer was 7.6 μm, the ratio _T 2 / _{T 1} of the total thickness _{T 2} of the skin layer to the thickness _{T 1} of the layer was about 0.67. From the stretchable material (Xa-7), a test piece having a width of 5 cm and a length of 7 cm (stretching portion 5 cm, sandwiching portions 1 cm at both ends) was obtained, and the above stretching tests 1 to 3 were performed.

  From the results of the stretching tests 1 to 3, the stretchable material (Xa-7) has a sufficiently low shrinkage rate when stretched, excellent stretch uniformity, and a tensile stress when stretched by 300%. It was confirmed that it was 110% or less of the stress.

(Example X-8)
The amount of the resin material (X-B) constituting the first skin layer and the second skin layer was changed to 8.75 g, respectively, and the amount of the resin material (X-A-2) constituting the core layer was changed to 17 A tape-like stretchable material (Xa-8) having a width of 5 cm was obtained in the same manner as in Example X-4 except that the thickness was changed to 0.5 g.

In the obtained stretchable material (Xa-8), the thickness of the first skin layer was 9.5 μm, the thickness of the core layer was 19.9 μm, the thickness of the second skin layer was 9.5 μm, The ratio T ₂ / T ₁ of the total thickness T ₂ of the skin layer to the thickness T ₁ of the layer was 1.0. From the stretchable material (X-a-8), a test piece having a width of 5 cm and a length of 7 cm (stretching part 5 cm, sandwiching part 1 cm at both ends) was obtained, and the above stretching tests 1 to 3 were performed. Described.

  From the results of the stretching tests 1 to 3, the stretchable material (X-8) has a sufficiently low shrinkage rate when stretched, and the tensile stress when stretched by 300% is 110% or less of the tensile yield stress of the skin layer. confirmed.

(Comparative Example X-1)
As a comparison object, an elastic member used in Mooney S size manufactured by Unicharm Co., Ltd. was used (tape-like elastic material (X-b-1)). The material constituting the first and second skin layers was polypropylene, and the material constituting the core layer was styrene-isoprene-styrene block copolymer.

The thickness of the first skin layer is 3.8 μm, the thickness of the core layer is 30.4 μm, the thickness of the second skin layer is 3.8 μm, and the total thickness T ₂ of the skin layer relative to the thickness T ₁ of the core layer The ratio T ₂ / T ₁ was 0.25. From the stretchable material (X-b-1), a test piece having a width of 5 cm and a length of 7 cm (stretching portion 5 cm, sandwiching portions 1 cm at both ends) was obtained, and the stretching tests 1 and 2 were performed.

  As a result of the stretching tests 1 and 2, in the stretchable material (Xb-1), the shrinkage rate at the time of stretching was larger than in Examples X-1 and X-6, and the stretched portion was not evenly stretched. .

(Reference Example X-1)
5 cm wide tape as in Example X-6, except that the resin material (X-B) constituting the skin layer was changed to “Novatec PP FA3EB” (manufactured by Nippon Polypro Co., Ltd., homopolypropylene). A stretchable material (X-b-2) was produced. In the obtained elastic material (Xb-2), the first skin layer has a thickness of 3.8 μm, the core layer has a thickness of 32.2 μm, and the second skin layer has a thickness of 3.8 μm. The ratio T ₂ / T ₁ of the total thickness T ₂ of the skin layer to the thickness T ₁ of the layer was 0.25. From the stretchable material (X-b-2), a test piece having a width of 5 cm and a length of 7 cm (stretching portion 5 cm, sandwiching portions 1 cm at both ends) was obtained, and the above stretching tests 1 and 2 were performed.

  As a result of the stretching tests 1 and 2, in the stretchable material (Xb-2), the shrinkage ratio at the time of stretching is larger than in Examples X-1 and X-6, and the stretched portion tends to be non-uniform. was there.

  A part of the results of the stretching tests 1 and 2 are shown in Tables 1 and 2.

[Examples mainly related to the second embodiment]
(Example Y-1)
As resin material (YA-1) constituting the core layer, 40 parts by weight of “Quintac 3620” (manufactured by Nippon Zeon Co., Ltd., styrene-isoprene-styrene block copolymer, mixture of linear polymer and branched polymer), 56 parts by weight of “Quintac 3390” (manufactured by Zeon Corporation, styrene-isoprene-styrene block copolymer, linear polymer), 4 parts by weight of 20% TiO ₂ -containing styrene-isoprene-styrene block copolymer-based white masterbatch , And a mixed material were used. The white masterbatch is added to give a white color. Moreover, “Novatec PP BC2E” (manufactured by Nippon Polypro Co., Ltd., ethylene propylene block copolymer) was used as the resin material (YB-1) constituting the skin layer.

By a co-extruded film manufacturing system manufactured by Sumitomo Heavy Industries Modern Co., Ltd., a first skin layer made of 3.5 g of resin material (Y-B-1), a core layer made of 28 g of resin material (Y-A-1), And the tape-shaped elastic material (Ya-1) with which the 2nd skin layer which consists of 3.5 g of resin materials (Y-B-1) was laminated | stacked in this order was produced. In the obtained elastic material (Ya-1), the thickness of the first skin layer is 3.8 μm, the thickness of the core layer is 30.4 μm, the thickness of the second skin layer is 3.8 μm, The ratio T ₂ / T ₁ of the total thickness T ₂ of the skin layer to the thickness T ₁ of the layer was 0.25.

  As a result of conducting the following elongation test on the obtained stretchable material (Ya-1), the strain by the elongation test was 20.0%.

  When a stretchable member is produced from a stretchable material (Ya-1) and applied to a clothing product, a good fit is maintained even when the stretched material is held for a long time in a stretched state and a temperature of about body temperature. It was.

<Extension test>
By stretching the elastic layer to 300% in the longitudinal direction (direction perpendicular to the direction in which the tape-shaped elastic material is conveyed in the coextrusion film production system, Cross Direction), the skin layer of the stretched part is plastically deformed, A stretchable part was produced. A test piece having a width of 4 cm and a length of 15 cm (stretched portion: 10 cm (= L5), sandwiched portions at both ends: 2.5 cm each) was obtained from the stretchable portion. Both ends of the test piece were sandwiched, the stretched part was stretched by 160%, and the stretched state was kept at 40 ° C. for 1 hour. After 1 hour, the stretched state was released, and the length L7 of the stretched portion was measured. From the lengths L5 and L7, the strain by the extension test was determined by the following formula.
Strain (%) by extension test = 100 × (L5-L7) / L5

(Example Y-2)
As the resin material (YA-2) constituting the core layer, 50 parts by weight of “Quintac 3620”, 46 parts by weight of “Quintac 3390”, and a styrene-isoprene-styrene block copolymer-based white masterbatch containing 20% TiO ₂ A mixed material was prepared by mixing 4 parts by mass. A stretchable material (Ya-2) was produced in the same manner as in Example Y-1, except that the resin material (YA-2) was used instead of the resin material (YA-1).

  About the obtained elastic material (Ya-2), when the extension test was done by the method similar to Example Y-1, the distortion by an extension test was 19.3%. In addition, when a stretchable member is produced from a stretchable material (Ya-2) and applied to a clothing product, even if it is held for a long time in a stretched state and a temperature of about body temperature, it has a good fit. Maintained.

(Example Y-3)
As a resin material (YB-2) constituting the skin layer, “Novatec PP FA3EB” (manufactured by Nippon Polypro Co., Ltd., polypropylene homopolymer) was prepared. An elastic material (Ya-3) was produced in the same manner as in Example Y-1, except that the resin material (YB-2) was used instead of the resin material (YB-1).

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Ya-3), the distortion | strain by an expansion | extension test was 19.0%. In addition, when a stretchable member is produced from a stretchable material (Ya-3) and applied to a clothing product, even when it is held for a long time in a stretched state and a temperature of about body temperature, it has good fit. Maintained.

(Example Y-4)
Resin material (Y-A-2) and resin material (Y-B-2) were prepared in the same manner as in Examples Y-2 and Y-3. Other than using resin material (Y-A-2) instead of resin material (Y-A-1) and using resin material (Y-B-2) instead of resin material (Y-B-1) Produced a stretchable material (Ya-4) in the same manner as in Example Y-1.

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Ya-4), the distortion | strain by an expansion | extension test was 16.7%. Moreover, when a stretchable member was produced from the stretchable material (Ya-4) and applied to a clothing product, even when it was held for a long time in a stretched state and a temperature of about body temperature, good fit was obtained. Maintained.

(Example Y-5)
Resin material (Y-B-2) was prepared in the same manner as Example Y-2. The resin material (Y-B-2) is used instead of the resin material (Y-B-1), and the amount of the resin material (Y-B-2) constituting the first skin layer and the second skin layer is determined. Each was changed to 7.0 g, and the elastic material (Y-a-) was changed in the same manner as in Example Y-1 except that the amount of the resin material (YA-1) constituting the core layer was changed to 21 g. 5) was produced.

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Ya-5), the distortion | strain by an expansion | extension test was 24.3%. Moreover, when an elastic member is produced from an elastic material (Ya-5) and applied to a clothing product, even when it is held for a long time in a stretched state and at a temperature of about body temperature, the fit is sufficient. Maintained.

(Example Y-6)
Resin material (Y-A-2) and resin material (Y-B-2) were prepared in the same manner as in Examples Y-2 and Y-3. The resin material (Y-A-1) is used instead of the resin material (Y-A-1), the resin material (Y-B-2) is used instead of the resin material (Y-B-1), and the first The amount of the resin material (Y-B-2) constituting the skin layer and the second skin layer was changed to 7.0 g, and the amount of the resin material (Y-A-2) constituting the core layer was 21 g. An elastic material (Ya-6) was produced in the same manner as in Example Y-1, except that the change was made.

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Ya-6), the distortion | strain by an expansion | extension test was 22.3%. In addition, when an elastic member is produced from an elastic material (Ya-6) and applied to a clothing product, even when it is held for a long time in a stretched state and at a temperature of about body temperature, the fit is sufficient. Maintained.

(Example Y-7)
As a resin material (YA-3) constituting the core layer, 96 parts by weight of “Quintac 3620” and 4 parts by weight of a 20% TiO ₂ -containing styrene-isoprene-styrene block copolymer-based white masterbatch were mixed. A mixed material was prepared. An elastic material (Ya-7) was produced in the same manner as in Example Y-1, except that the resin material (YA-3) was used instead of the resin material (YA-1).

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Ya-7), the distortion | strain by an expansion | extension test was 21.0%. In addition, when an elastic member is produced from an elastic material (Ya-7) and applied to a clothing product, even when it is held for a long time in a stretched state and at a temperature of about body temperature, the fit is sufficient. Maintained.

(Example Y-8)
Resin material (YA-3) and resin material (YB-2) were prepared in the same manner as in Examples Y-7 and Y-3. Other than using resin material (Y-A-3) instead of resin material (Y-A-1) and using resin material (Y-B-2) instead of resin material (Y-B-1) Produced a stretchable material (Ya-8) in the same manner as in Example Y-1.

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Ya-8), the distortion | strain by an expansion | extension test was 18.3%. In addition, when a stretchable member is produced from a stretchable material (Ya-8) and applied to a clothing product, even when it is held for a long time in a stretched state and at a temperature of about body temperature, it has good fit. Maintained.

(Example Y-9)
As a resin material (YA-4) constituting the core layer, 96 parts by mass of “Quintac 3450” (manufactured by Nippon Zeon Co., Ltd., styrene-isoprene-styrene block copolymer, branched polymer), containing 20% TiO ₂ A mixed material prepared by mixing 4 parts by mass of a styrene-isoprene-styrene block copolymer-based white masterbatch was prepared. A stretchable material (Ya-9) was produced in the same manner as in Example Y-1, except that the resin material (YA-4) was used instead of the resin material (YA-1).

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Ya-9), the distortion | strain by an expansion | extension test was 23.0%. In addition, when an elastic member is produced from an elastic material (Ya-9) and applied to a clothing product, even when it is held for a long time in a stretched state and a temperature of about body temperature, it has a good fit. Maintained.

(Comparative Example Y-1)
As a comparison object, the elastic member currently used by the Mooney S size by Unicharm Co., Ltd. was used as a commercially available clothing product (tape-shaped elastic material (Yb-1)). The tape-shaped stretchable material (Yb-1) had polypropylene layers on both sides of the core made of styrene-isoprene-styrene block copolymer. The core thickness was 30.4 μm, and the polypropylene layer thickness was 3.8 μm.

  For the tape-shaped stretchable material (Yb-1), an extension test was performed in the same manner as in Example Y-1. The strain by the extension test was 30.7%. Moreover, in the garment product using the tape-shaped stretchable material (Yb-1), the stretchable portion is easily distorted by long-time stretching, and it is difficult to maintain sufficient fit.

(Reference Example Y-1)
As the resin material (YA-4) constituting the core layer, “Kraton D1114P” (manufactured by Kraton Polymer Japan, styrene-isoprene-styrene block copolymer, linear polymer) was prepared. A stretchable material (Yc-1) was produced in the same manner as in Example Y-1, except that the resin material (YA-4) was used instead of the resin material (YA-1). .

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Yc-1), the distortion | strain by an expansion | extension test was 25.3%. Moreover, when an elastic member was produced from the elastic material (Yc-1) and applied to a clothing product, the stretchable part was easily distorted by stretching for a long time, and the fit property tended to be inferior compared to the examples. It was.

(Reference Example Y-2)
As a resin material (YA-5) constituting the core layer, 96 parts by mass of “Quintac 3421” (manufactured by Nippon Zeon Co., Ltd., styrene-isoprene-styrene block copolymer, linear polymer), and containing 20% TiO ₂ A mixed material was prepared by mixing 4 parts by mass of a white masterbatch based on styrene-isoprene-styrene block copolymer. A stretchable material (Yc-2) was produced in the same manner as in Example Y-1, except that the resin material (YA-5) was used instead of the resin material (YA-1).

  When the expansion | extension test was done by the method similar to Example Y-1 about the obtained elastic material (Yc-2), the distortion | strain by an expansion | extension test was 33.0%. Moreover, when an elastic member was produced from the elastic material (Yc-2) and applied to a clothing product, the stretchable part was easily distorted by stretching for a long time, and the fit property tended to be inferior compared to the examples. It was.

(Example Y-10)
“Quintac 3620” was prepared as a resin material constituting the core layer. An elastic material (Ya-10) was produced in the same manner as in Example Y-1, except that “Quintac 3620” was used instead of the resin material (Y-A-1).

  A test piece having a width of 25 mm and a length of 100 mm (stretched portion 25 mm, sandwiched portions 37.5 mm) was obtained from the stretchable material (Ya-10), and the following tests were performed. As a result of the test, the first-time stress (at 100%) was 1.80 (N / 25 mm), and the second-time return stress (at 50%) was 0.20 (N / 25 mm).

<Stress measurement test>
Both ends of the test piece were sandwiched and stretched to 100% at 300 mm / min in the longitudinal direction, and the stress (going stress) at that time was measured. The measurement result was defined as a first-time stress (100%) (1st loading force at 100%) (N / 25 mm).
Next, the stretched state was released, and again stretched to 100% at 300 mm / min, and then returned to 50% at 300 mm / min. The stress (return stress) when the elongation was returned to 50% was measured, and the measurement result was defined as the second return stress (50%) (2nd unloading force at 50%) (N / 25 mm).

(Example Y-11)
“Quintac 3450” was prepared as a resin material constituting the core layer. A stretchable material (Ya-11) was produced in the same manner as in Example Y-1, except that “Quintac 3450” was used instead of the resin material (YA-1).

  When the obtained stretchable material (Y-a-11) was tested in the same manner as in Example Y-10, the result was that the first-time stress (100%) was 1.62 (N / 25 mm). The second return stress (50%) was 0.20 (N / 25 mm).

(Reference Example Y-3)
“Quintac 3421” was prepared as a resin material constituting the core layer. A stretchable material (Yc-3) was produced in the same manner as in Example Y-1, except that “Quintac 3421” was used instead of the resin material (Y-A-1).

  When the obtained stretchable material (Yc-3) was tested in the same manner as in Example Y-10, the result was a first-time stress (at 100%) of 1.58 (N / 25 mm). The second return stress (at 50%) was 0.12 (N / 25 mm).

  From Example Y-10, Example Y-11, and Reference Example Y-3, when the core layer contains a branched polymer, the second return stress (at 50) is greater than when the core layer contains only a linear polymer. %) Increases. A large second return stress (50%) means that when the stretch material is applied to a clothing product, the force of fitting the clothing product to the wearer's body is great. From this, it can be said that the stretchable material containing a branched polymer in the core layer is particularly suitable for applications requiring fit. If the first-time stress (100%) is small, the force required for the stretching treatment of the stretchable material is small and the workability is excellent. In Example Y-10 and Example Y-11, the second return stress (at 50%) can be increased while the first-time stress (at 100%) is kept within a range where sufficient workability can be obtained. ing.

  DESCRIPTION OF SYMBOLS 1 ... Core layer, 2 ... Skin layer, 10 ... Elastic material, 14 ... Shape holding part, 15 ... Elastic part, 20 ... Elastic member.

Claims (31)

A core layer comprising an elastomer;
At least one skin layer comprising a resin material having a 10% tensile stress higher than the core layer in at least one direction and forming a microphase separation structure;
A stretchable material.   The elastic material according to claim 1, wherein the skin layers are provided on both main surfaces of the core layer.   The stretchable material according to claim 1 or 2, wherein the resin material contains a block copolymer.   The elastic material as described in any one of Claims 1-3 whose thickness of the said core layer is more than the thickness of the said skin layer. The ratio _T 2 / _{T 1} of the said skin layers having a thickness of _{T 2} to the thickness _{T 1} of the said core layer is 0.1 to 1.0, stretchable material according to any one of claims 1-4 . The stretchable material according to claim 5, wherein the ratio T ₂ / T ₁ is 0.2 or more and 0.5 or less. In at least one direction,
The tensile stress at 300% elongation is 110% or less of the tensile yield stress of the skin layer, and the shrinkage ratio in the width direction perpendicular to the elongation direction at 200% elongation is 30% or less. The elastic material as described in any one of -6. A core layer comprising an elastomer;
At least one skin layer having a tensile yield stress lower than the core layer in at least one direction;
With
In at least one direction,
An elastic material having a tensile stress at 300% elongation of 110% or less of the tensile yield stress of the skin layer and a shrinkage ratio in the width direction perpendicular to the elongation direction at 200% elongation of 30% or less.   The elastic material according to claim 8, wherein the skin layers are respectively provided on both main surfaces of the core layer.   The elastic material according to claim 8 or 9, wherein a thickness of the core layer is equal to or greater than a thickness of the skin layer. The stretch material according to any one of claims 8 to 10, wherein a ratio T ₂ / T ₁ of the thickness T ₂ of the skin layer to the thickness T _{1 of the} core layer is 0.1 or more and 1.0 or less. . The stretchable material according to claim 11, wherein the ratio T ₂ / T ₁ is 0.2 or more and 0.5 or less.   A stretchability comprising: a stretchable portion having a structure in which the skin layer of the stretchable material according to any one of claims 1 to 12 is plastically deformed; and a shape holding portion in which the layered structure of the stretchable material is maintained. Element.   The manufacturing method of an elastic member provided with the process of extending at least one part of the elastic material as described in any one of Claims 1-12, and plastically deforming at least one part of the said skin layer.   In the step, a part of the skin layer is plastically deformed to form a shape holding portion in which a layer structure of the stretchable material is maintained, and a stretchable portion in which the skin layer is plastically deformed. The manufacturing method as described.   A clothing product comprising the stretchable member according to claim 13. A core layer comprising an elastomer;
At least one skin layer having a 10% tensile stress higher than the core layer in at least one direction;
With
When a stretchable portion is formed by stretching 300% in one direction and plastically deforming the skin layer, the stretchable portion has a strain of 25% or less by stretching 160% and holding at 40 ° C. for 1 hour. ,
Elastic material.   The elastic material according to claim 17, wherein the skin layers are provided on both main surfaces of the core layer.   The stretchable material according to claim 17 or 18, wherein a thickness of the core layer is equal to or greater than a thickness of the skin layer. The ratio _T 2 / _{T 1} of the said skin layers having a thickness of _{T 2} to the thickness _{T 1} of the said core layer is 0.1 to 1.0, stretchable material according to any one of claims 17 to 19 .   The stretchable material according to any one of claims 17 to 20, wherein a tensile stress at 300% elongation is 110% or less of a tensile yield stress of the skin layer in at least one direction. A core layer comprising an elastomer;
At least one skin layer having a 10% tensile stress higher than the core layer in at least one direction;
With
The elastomer contains a branched polymer;
Elastic material.   The elastic material according to claim 22, wherein the elastomer further contains a linear polymer.   The stretchable material according to claim 22 or 23, wherein the skin layers are provided on both main surfaces of the core layer.   The elastic material as described in any one of Claims 22-24 whose thickness of the said core layer is below the thickness of the said skin layer. The ratio _T 2 / _{T 1} of the said skin layers having a thickness of _{T 2} to the thickness _{T 1} of the said core layer is 0.1 to 1.0, stretchable material according to any one of claims 22 to 25 .   The stretchable material according to any one of claims 22 to 26, wherein the tensile stress at 300% elongation is 110% or less of the tensile yield stress of the skin layer in at least one direction. An elastic part having a structure in which the skin layer of the elastic material according to any one of claims 17 to 27 is plastically deformed;
A shape holding portion in which the layer structure of the stretchable material is maintained;
A stretchable member.   The manufacturing method of an elastic member provided with the process of extending at least one part of the elastic material as described in any one of Claims 17-27, and plastically deforming at least one part of the said skin layer.   30. The step according to claim 29, wherein in the step, a part of the skin layer is plastically deformed to form a shape holding portion in which a layer structure of the stretchable material is maintained and a stretchable portion in which the skin layer is plastically deformed. Production method.   A clothing product comprising the stretchable material according to any one of claims 17 to 27 or the stretchable member according to claim 28.

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