JP2018199877A - Leather-like sheet and wearing article using the same - Google Patents

Abstract

To provide a leather-like sheet that is easy to deform conforming to the slow movement of the human body and is easy to absorb energy received by the impact and the like to a quick movement of the body.SOLUTION: A leather-like sheet comprising a fabric and polyurethane applied on the fabric is used. In the leather-like sheet, the glass transition temperature that corresponds to a peak value of a loss tangent is 0 to 40°C and the loss tangent at the glass transition temperature is 0.2 or more and at 25°C median E(1) of the complex modulus of elasticity Ein a frequency range of 10 to 50 Hz is larger than median E(2) of the complex modulus of elasticity in a frequency range of 0.1 to 1 Hz.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a leather-like sheet that easily deforms following the shape of a human body, has excellent wearability and retention during exercise, and easily absorbs energy received by impact.

  2. Description of the Related Art Leather-like sheets such as artificial leather containing a nonwoven fabric and polyurethane applied to the nonwoven fabric are widely used as materials for articles worn on the human body such as sports gloves (including gloves) and shoes.

  Although it is not a technique related to a leather-like sheet, the following Patent Document 1 and the following Patent Document 2 disclose a material using a polyurethane foam as a material that easily deforms following the movement of the human body. For example, the following Patent Document 1 discloses a cushion for a human body using a polyurethane foam having specific viscoelastic characteristics, a knee pad and leggers used in bra cups, shoulder pads, insoles, sports, etc., and a buffer in a helmet. Disclosure of materials. Patent Document 2 below also discloses a polyurethane foam having specific viscoelastic properties for mounting on a human body.

JP 2009-035697 A JP2013-147530A

  When a person wears an article using a conventional leather-like sheet, the leather-like sheet does not deform sufficiently following the movement of the person, so that the fit is insufficient. Moreover, the ability to absorb the energy received by the impact was poor. Furthermore, due to insufficient wearability and retention during intense exercise, for example, in the case of gloves, the ability to grip objects is insufficient, and in the case of shoes, the load on the foot can be sufficiently eased. There wasn't.

  In order to solve the above-described problems, the present invention easily deforms following a slow movement of a human body, and has excellent wearability and holding ability for a fast movement, and is affected by an impact. An object is to provide a leather-like sheet that easily absorbs energy.

One aspect of the present invention includes a fabric and polyurethane applied to the fabric, and has a glass transition temperature of 0 to 40 ° C., which is a temperature corresponding to a peak value of loss tangent (tan δ), and at the glass transition temperature. Loss tangent is 0.2 or more, and at 25 ° C., the median E ^* (1) of the complex elastic modulus E ^* in the frequency region of 10 to 50 Hz is the center of the complex elastic modulus in the frequency region of 0.1 to 1 Hz. Value E ^* (2) Higher leather-like sheet. When an article using a leather-like sheet is worn on a person, it will soften due to the heat received from body temperature for slow movements, so it will follow the movements of the person and deform to fit the human body. On the other hand, it is easy to absorb the impact, and the wearability and the holding property are improved. E ^* (1) is, for example, 80 MPa or more, and E ^* (2) is more preferably less than 80 MPa.

  The polyurethane is preferably a non-foamed polyurethane from the viewpoint of excellent abrasion resistance.

  Moreover, since it is excellent in a fullness that a fabric is a nonwoven fabric, it is preferable from the point from which the article | item using the leather-like sheet | seat excellent in the feeling of fitting is obtained.

  Another aspect of the present invention is an attached product using any one of the above leather-like sheets as a material. As an example, if you wear a sports glove, it will deform easily to fit the shape of your hand when you wear it, and when you receive a ball or hit a ball with a golf club or bat, It becomes easier to absorb the energy caused by the impact.

  The leather-like sheet of the present invention, when used as a material for an article to be worn on a human body, easily deforms following a human movement and has a high fit. Further, according to the wearing product of the present invention, for example, in the case of sports gloves, it becomes easier to grip a ball, club, bat, etc., for example, in the case of sports shoes, while having a high fit, It becomes easier to absorb shocks when strenuous exercise is performed.

It is a graph which shows the temperature dependence of tan-delta of the artificial leather which is the leather-like sheet | seat obtained by the Example and the comparative example. It is a graph which shows the frequency dependence of the complex elastic modulus E ^* in 25 degreeC of the artificial leather which is the leather-like sheet | seat obtained by the Example and the comparative example.

  The leather-like sheet of this embodiment is a leather-like sheet such as artificial leather or synthetic leather having viscoelastic properties described later, including a fabric and polyurethane impregnated in the fabric.

  Examples of the fabric include sheets of fiber structures such as nonwoven fabrics and knitted fabrics of various fibers.

  The type of fiber forming the fabric is not particularly limited. For example, polyethylene terephthalate (PET), modified polyethylene terephthalate, polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polytriethylene terephthalate, polyhexamethylene terephthalate, Aromatic polyester resins such as polypropylene terephthalate and polyethylene naphthalate, aliphatic polyesters such as polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, and polyhydroxybutyrate-polyhydroxyvalerate copolymer Polyester fiber such as resin; polyamide 6, polyamide 66, polyamide 610, polyamide 10, polyamide 11, polyamide 12, polyamide 6 Polyamide resins such as 2; Polypropylene resins such as polypropylene, polyethylene, polybutene, polymethylpentene, chlorinated polyolefins, ethylene vinyl acetate copolymers, styrene ethylene copolymers; Modifications containing 25 to 70 mol% of ethylene units Examples thereof include modified polyvinyl alcohol resins formed from polyvinyl alcohol and the like; and crystalline elastomers such as polyurethane elastomers, polyamide elastomers, and polyester elastomers.

  For example, when using a non-woven fabric, the single fiber fineness of the fibers forming the non-woven fabric may be a regular fiber such as more than 1 dtex or an ultrafine fiber such as 1 dtex or less. In the case of producing a leather-like sheet article, it is preferably an ultrafine fiber. The single fiber fineness of the ultrafine fiber is 1 dtex or less, further 0.0001 to 0.9 dtex, particularly 0.001 to 0.5 dtex, and more particularly 0.003 to 0.1 dtex, which is a dense material with excellent texture. It is preferable from the point by which a nonwoven fabric is obtained. Such non-woven fabrics of ultrafine fibers are obtained by, for example, ultrafine treatment of ultrafine fiber-generating fibers such as sea-island cross-section fibers and multilayer laminated cross-section fibers obtained by using a mixed spinning method or a composite spinning method. A fiber entanglement is preferred.

  Examples of the polyurethane applied by impregnating the fabric used in the production of the leather-like sheet of the present embodiment include polyurethanes obtained by polymerizing an isocyanate component, a polyol component and a chain extender as described below.

  As the isocyanate component used for producing the polyurethane used for producing the leather-like sheet of the present embodiment, those conventionally used for producing polyurethane can be used without any particular limitation. Specific examples thereof include 2,4- or 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, m- or p-phenylene diisocyanate, isophorone diisocyanate, and the like. These may be used alone or in combination of two or more. Of these, 4,4'-diphenylmethane diisocyanate is particularly preferred.

  Moreover, as a polyol component, the compound which has at least 2 or more active hydrogen in 1 molecule, especially a hydroxyl group is mentioned. Specific examples thereof include polyoxyalkylene polyols produced by adding alkylene oxides to polyhydric alcohols such as diols and triols, aliphatic amines and aromatic amines as initiators, and condensation of acids and alcohols. Polyester polyols produced by the above, or polytetramethylene glycol, polybutadiene polyol, polypropylene glycol, poly 1,4-butylene glycol adipate, polyethylene glycol adipate, polytetramethylene glycol, polyethylene glycol, propylene oxide adduct of bisphenol A . Although the molecular weight of a polyol is not specifically limited, It is preferable that it is a weight average molecular weight 200-2000 grade. As the polyol component, a propylene oxide adduct of bisphenol A is particularly preferable.

  Examples of the chain extender include glycols such as ethylene glycol, 1,4-butanediol and diethylene glycol, amines such as diethanolamine, triethanolamine, tolylenediamine and hexamethylenediamine, and TDI (tolylene diisocyanate) of trimethylolpropane. And polyisocyanates such as adduct, triphenylmethane triisocyanate, bis (2-hydroxyethyl) hydroquinone, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, and the like. Among these, 1,4-butanediol is particularly preferable.

  The molar ratio of isocyanate component: chain extender: polyol component is 1.5-3: 0.5-2: 1, more particularly 1.8-2.5: 0.8-1.5: 1, especially Is preferably 1.9 to 2.2: 0.9 to 1.2: 1.

  Moreover, you may use a catalyst in order to accelerate | stimulate reaction as needed. Examples of the catalyst include metal catalysts such as tertiary amines such as triethylamine, tetramethylhexamethylenediamine, and tolylenediamine, and tin-based catalysts such as stannous octylate, stanas oleate, and dibutyltin dilaurate. . These may be used alone or in combination of two or more.

  Polyurethane is synthesized using the above-mentioned raw materials including isocyanate, polyol, chain extender and, if necessary, catalyst. Specific examples of the synthesis method include methods disclosed in, for example, JP-A-61-293214 and JP-A-63-244341.

  Polyurethane is prepared in solution and used to impregnate fabrics. The solvent for preparing the polyurethane solution is not particularly limited. Specifically, for example, an organic solvent such as N, N-dimethylformamide (DMF), acetone, methyl ethyl ketone, and tetrahydrofuran can be used. Among these, DMF is particularly preferable because it is a good solvent for polyurethane and has excellent wet coagulation properties. If the fabric is impregnated with a polyurethane solution and immersed in, for example, a water bath having a liquid temperature of 25 to 70 ° C., the polyurethane is wet-coagulated in the voids in the fabric.

  As a content rate of the polyurethane with respect to the total amount with a fabric, it is 20-70 mass%, Furthermore, it is preferable that it is 30-65 mass%, especially 40-60 mass%.

  The polyurethane may be a foam or a non-foam. Further, even if only polyurethane is used alone, it is within the range not impairing the effects of the present invention, other polyurethanes, acrylic elastic bodies other than polyurethane, polyamide elastic bodies such as polyamide elastomers, and polyester elastic bodies such as polyester elastomers. , A polystyrene elastic body, a polyolefin elastic body, and an elastic polymer body such as an elastic silicone resin may be used in combination.

  A leather-like sheet can be obtained by finishing the fiber base material obtained by applying polyurethane to the fabric. As a finishing treatment, a leather-like sheet having a raised surface such as a suede tone or a nubuck tone can be obtained by buffing the surface of the fiber base material to raise the surface fibers. Moreover, the leather-like sheet | seat which has the surface of a silver tone is obtained by providing a resin layer by the well-known method as a finishing process on the surface of a fiber base material.

  Although the thickness of a leather-like sheet | seat is not specifically limited, For example, it is preferable that it is about 300-3000 micrometers, Furthermore, about 500-1500 micrometers.

The leather-like sheet of the present embodiment includes a fabric and polyurethane applied to the fabric, has a glass transition temperature of 0 to 40 ° C., which is a temperature corresponding to a peak value of loss tangent (tan δ), and a glass transition. tanδ in the temperature is not less than 0.2, at 25 ° C., the center value of the complex elastic modulus ^{E *} in the frequency domain of the 10~50Hz ^{E *} (1) of complex elastic modulus in the frequency domain of the 0.1~1Hz center It is higher than the value E ^* (2). The complex elastic modulus E ^* is obtained from the relationship of E ^{* 2} = E ′ ² + E ″ ^{2. Further} , tan δ is the ratio of the loss elastic modulus E ″ to the storage elastic modulus E ′ (E ″ / E ′). Defined by

  The temperature of the human body surface is usually 28-30 ° C. For this reason, when an article using the leather-like sheet of this embodiment is attached to the surface of the human body, the leather becomes soft at body temperature by having a glass transition temperature in the range of 0 to 40 ° C., which is near the temperature of the body surface. A sheet is obtained.

  In the leather-like sheet of this embodiment, tan δ at the glass transition temperature is 0.2 or more, preferably 0.2 to 0.6, and more preferably 0.2 to 0.5. When tan δ at the glass transition temperature is less than 0.2, the resilience becomes strong and rubber-like is obtained. Further, when tan δ at the glass transition temperature is too high, the rebound is too low and the deformed shape tends to be difficult to return.

Further, the frequency dependency of the complex elastic modulus E ^* is an index of the form maintaining property during exercise. The leather-like sheet of the present embodiment, at 25 ° C., the center value of the complex elastic modulus in the frequency domain of the 10~50Hz E ^* (1) is the center value of the complex elastic modulus in the frequency domain of the 0.1~1Hz E ^* ( It has higher characteristics than 2). In such a case, it is easily deformed to fit the shape of the hand at the time of wearing, and it is easy to absorb energy received by impact during exercise. E ^* (1) is, for example, 80 MPa or more, and E ^* (2) is preferably less than 80 MPa. If E ^* (1) is too low, deformation tends to occur during exercise. In addition, when E ^* (1) is too high, there is a tendency for the wearing feeling during exercise to deteriorate. Moreover, when E ^* (2) is too high, the wearing feeling at the time of wearing tends to deteriorate.

  In addition, the frequency of the human body surface at the time of slow motion is about 0.1-1 Hz. On the other hand, the frequency of the surface of the human body when subjected to an impact by exercise is about 10 to 50 Hz. When an article using a leather-like sheet having the above characteristics is attached to the human body, the leather-like sheet easily follows the movement of the person against the slow movement when wearing, so the wearer must A high fit can be obtained. On the other hand, when the wearer receives an impact while exercising, the leather-like sheet absorbs energy from the impact and converts it into heat, so that a good impact absorbability can be obtained. Such leather-like sheets are articles worn on the human body such as gloves (gloves) and shoes, in particular, sports gloves (golf gloves, baseball gloves) and sports shoes (running shoes, It is preferably used as a material such as tennis shoes.

  For example, golf gloves are manufactured by slicing a leather-like sheet into a shape along the shape of a hand and sewing it. The golf gloves manufactured in this way are manufactured in a plurality of sizes as ready-made products, but it was difficult to prepare many sizes that fit more finely by hand. Golf gloves manufactured using a leather-like sheet as described above may have individual differences in hand size compared to golf gloves using conventional leather-like sheets in order to fit the shape of the hand due to body temperature. , Can ensure a fit. Also, because it follows the shape of the hand at body temperature and absorbs the energy of fast movements such as impact and vibration, it absorbs vibration and protects the hand when the ball is hit, and deformation is suppressed Thus, the shape of the hand at the contact portion is maintained, and the grip is prevented from shifting.

  Hereinafter, the present invention will be described more specifically with reference to examples. The scope of the present invention is not limited to these examples.

[Example 1]
Polyamide non-woven fabric with an average fineness of 0.007 dtex is impregnated with a 13% by mass DMF solution of polyurethane “HB-21” manufactured by SMP Technologies Inc. so that the mass ratio of polyurethane / non-woven fabric is 35/65 in terms of polyurethane solid content. And a fiber substrate having a thickness of 1.5 mm, which was wet-solidified in water, was prepared. The surface layer of the obtained fiber base material was buffed and raised to obtain a raised artificial leather as a leather-like sheet. The polyurethane was a non-porous polyurethane.

  And the obtained artificial leather was evaluated as follows.

(Evaluation of dynamic viscoelasticity of artificial leather)
A test piece of artificial leather having a width of 10 mm and a length of 40 mm was prepared. Then, the storage elastic modulus E ′ and loss elastic modulus E ″ of the test piece when the measurement temperature was changed were measured using a viscoelasticity measuring device (DMS6100 manufactured by SII Nanotechnology Inc.). : Tensile, frequency: 1 Hz, measurement temperature: -60 to 110 ° C., heating rate: 5 ° C./min, and ratio E ″ / E ′ of loss elastic modulus E ″ to storage elastic modulus E ′ is tan δ From the graph showing the change of tan δ with respect to the temperature, the temperature at which tan δ becomes maximum in the measurement temperature range was defined as the glass transition temperature T _g .

(Glove characteristics)
A baseball glove was created using the obtained artificial leather. Then, with 10 baseball experienced players wearing gloves, 100 hard balls were hit, scored according to the following criteria, and determined by majority vote.
A: The glove fits the movement of the hand, and when the ball was hit, the hand, the glove, and the bat were hardly displaced, and it was strongly felt that the shock was absorbed well.
B: The glove fits the movement of the hand, and when the ball was hit, the hand, the glove, and the bat were hardly displaced, and it was felt that the shock was absorbed well.
C: It was felt that there was a gap between the glove and the hand, and that there was a gap between the hand, the glove and the bat when hit.

(Shoe characteristics)
Running shoes were created using the obtained artificial leather. Then, 10 athletes who experienced athletics scored according to the following criteria, and judged by majority vote.

A: The shoe fits the movement of the foot, and when dashing, it was hard to cause a shift between the foot and the shoe, and it was strongly felt that the shock was well absorbed.
B: The shoe fits the movement of the foot, and when dashing, it was difficult to cause a shift between the foot and the shoe, and it was somewhat felt that the shock was absorbed well.
C: It was felt that there was a gap between the shoe and the foot, and when the dash was made, there was a shift between the foot and the shoe.

The results are shown in Table 1. FIG. 1 shows the temperature dependence of tan δ, and FIG. 2 shows the frequency dependence of the complex elastic modulus E ^* at 25 ° C.

[Example 2]
Polyamide-based non-woven fabric with an average fineness of 0.007 dtex is impregnated with a 20% by mass DMF solution of polyurethane “HB-21” manufactured by SMP Technologies Co., Ltd. so that the mass ratio of polyurethane / non-woven fabric is 50/50 in terms of polyurethane solid content. And a fiber substrate having a thickness of 1.5 mm, which was wet-solidified in water, was prepared. The surface layer of the obtained fiber base material was buffed and raised to obtain a raised artificial leather.

  The obtained artificial leather was evaluated in the same manner as in Example 1. The results are shown in Table 1, FIG. 1 and FIG.

[Comparative Example 1]
A 13% by weight DMF solution of a polyether-based polyurethane having a glass transition temperature of about −40 ° C. is applied to a polyamide-based nonwoven fabric having an average fineness of 0.007 dtex so that the mass ratio of polyurethane / non-woven fabric is 35/65 in terms of polyurethane solid content. A fiber substrate having a thickness of 1.5 mm that was impregnated and wet-solidified in water was prepared. The surface layer of the obtained fiber base material was buffed and raised to obtain a raised artificial leather.

  The obtained artificial leather was evaluated in the same manner as in Example 1. The results are shown in Table 1, FIG. 1 and FIG.

Claims (5)

The glass transition temperature, which is a temperature corresponding to the peak value of loss tangent (tan δ), is 0 to 40 ° C., and the loss tangent at the glass transition temperature is 0.2. That's it,
At 25 ° C., the median E ^* (1) of the complex elastic modulus E ^* in the frequency region of 10 to 50 Hz is higher than the median E ^* (2) of the complex elastic modulus in the frequency region of 0.1 to 1 Hz. Characteristic leather-like sheet. The leather-like sheet according to claim 1, wherein E ^* (1) is 80 MPa or more and E ^* (2) is less than 80 MPa.   The leather-like sheet according to claim 1 or 2, wherein the polyurethane is non-foamed polyurethane.   The leather-like sheet according to any one of claims 1 to 3, wherein the fabric is a non-woven fabric.   The wearing goods characterized by using the leather-like sheet of any one of Claims 1-4 as a raw material.