JP2015139680A - Ball skin material and ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball skin material that holds high wear resistance, while suppressing such a tactile sensation as the fingers sink at the time when grasping a ball, and maintaining a surface tactile sensation close to the tactile sensation of cowhide skin materials and sticking to the surface.SOLUTION: A ball skin material includes: a fiber base material 1 containing a nonwoven fabric containing extra-fine filaments with fineness of 0.5 dtex or less, and a high polymer elastic body impregnated and imparted to the nonwoven fabric; a surface resin layer 2; and an adhesion layer 5 with a thickness of 100 μm or less for making the surface resin layer 2 adhere to the fiber base material 1. The surface resin layer 2 contains a first layer 3 with the thickness of 10-50 μm, and a second layer 4 arranged at the surface side of the ball from the first layer 3 and having the thickness of 10-20 μm. The first layer 3 contains 50-90 mass% of a first high polymer elastic body with 100% modulus of 4-8 MPa and 10-50 mass% of inorganic particles. The second layer 4 contains 50-90 mass% of a second high polymer elastic body with 100% modulus of 10-15 MPa and 10-50 mass% of inorganic particles.

Description

  The present invention relates to a skin material for a ball used for baseball, softball, and the like. Specifically, the present invention relates to a skin material for a ball made of so-called artificial leather that is sewn over a core ball.

  Conventionally, a hard baseball for games is produced by wrapping a core ball material mainly composed of cork, rubber or the like with two pieces of cow leather and sewing them together with a sewing thread. Baseball Rules 1.09 "The ball is made by wrapping a thread around a small core of cork, rubber or similar material, wrapping it in two pieces of white horseskin or cowhide, and stitching it firmly. The weight is 5 oz to 5 oz 1 / 4 (141.7 g to 148.8 g), and the circumference is 9 in to 9 in 1/4 (22.9 cm to 23.5 cm).

  Since cowhide uses leather as a raw material, there are large variations in properties such as strength depending on the individual cows and the parts used. In addition, cow leather is easy to absorb moisture when it gets wet in the rain, is easy to wear on the surface, and is relatively expensive. A hard baseball that uses so-called artificial leather as a skin material instead of cowhide, which has solved the disadvantages of such a hard baseball for games using cowhide, is also known. A hard baseball using such artificial leather as a skin material is usually used as a practice ball. Hardball baseballs for practice using artificial leather as the skin material have relatively small variations in properties between the skin materials, and it is difficult to absorb moisture by controlling the properties of the resin component that becomes the surface resin layer. Moreover, it is relatively inexpensive and excellent in durability.

  Various skin materials for balls using artificial leather as described above have been proposed. For example, in Patent Document 1 below, a base layer, a binder layer, and a film layer are arranged in this order, the base layer has an impregnated layer composed of a fiber entangled body and a porous polymer elastic body, and the film layer is 100 Disclosed is a ball skin material containing a polymer elastic body and inorganic particles having a% modulus of 4 to 8 MPa, an inorganic particle content of 20 to 50% by weight, and a thickness of 20 to 150 μm. Further, for example, in Patent Document 2 below, 20% strength in any one direction (AD) and its direction (AD) in order to suppress the occurrence of wrinkles that occur during sewing and the tearing of the sewn portion when repeatedly used. A skin material for a ball is disclosed in which the ratio (AD / OD) of 20% strength in the direction (OD) perpendicular to () is in the range of 0.8 to 1.2.

JP 2011-24788 A JP 2012-230368 A

  A ball using artificial leather mainly used for practice as a skin material has the following disadvantages compared to a ball using cow leather mainly used for games as a skin material. Since the skin material of cowhide is finished by embossing the skin layer of cowhide containing dense collagen fibers, the ball using cowhide as the skin material compares the feeling that a finger sinks when the pitcher holds it The surface feels small and sticks to the surface. On the other hand, a ball using artificial leather as a skin material has a softer surface than a ball using cowhide as a skin material, and the touch that a finger sinks when the ball is held remains. Since a subtle difference in feel when the ball is held greatly affects the controllability of the pitcher, a difference in feel between the baseball for the game and the baseball for practice is not preferable. Further, by providing a resin layer containing a polymer elastic body having a low modulus on the surface layer of the artificial leather, it is possible to impart a tactile sensation that attracts the surface of the cowhide skin material. However, when a resin layer including such a polymer elastic body having a low modulus is provided, there is a problem that wear resistance is lowered.

  The present invention does not leave a feeling that the finger sinks when the pitcher grasps the ball, and also maintains a surface feel that sticks to the surface close to that of the cowhide skin material, while maintaining high wear resistance. An object of the present invention is to provide a skin material for a ball using an artificial leather that can hold the skin.

  A skin material for a ball according to the present invention (hereinafter also simply referred to as a skin material) includes a non-woven fabric containing ultrafine fibers having a fineness of 0.5 dtex or less, and a fiber substrate containing a polymer elastic body impregnated in the non-woven fabric, and a surface A resin layer, and an adhesive layer having a thickness of 100 μm or less for adhering the surface resin layer and the fiber base, and the surface resin layer is a ball having a thickness of 10 to 50 μm and a ball that is more ball And a second layer having a thickness of 10 to 20 μm disposed on the surface side of the first polymer elastic body, the first polymer elastic body having a 100% modulus of 4 to 8 MPa and 50 to 90% by mass and inorganic particles The second layer contains 10 to 50% by mass of a second polymer elastic body having a 100% modulus of 10 to 15 MPa and 10 to 50% by mass of inorganic particles.

  In the case of a skin material using a nonwoven fabric having a low fiber density made of fibers of ordinary fineness, which has been widely used in the past, a thick foamed urethane layer or the like is disposed because the surface irregularities formed by the fibers of the nonwoven fabric are large. Otherwise, there was a problem that the unevenness of the fibers would appear on the surface resin layer. When such a thick urethane foam layer is provided, it is felt that the finger sinks when the ball is gripped. When a non-woven fabric containing ultrafine fibers having a fineness of 0.5 dtex or less and a fiber base material containing a polymer elastic body impregnated in the non-woven fabric can be used, the surface of the non-woven fabric itself can be finished densely and smoothly. A smooth surface resin layer can be formed without a thick foamed urethane layer or the like. Therefore, by bonding the fiber base material and the surface resin layer with an adhesive layer having a thickness of 100 μm or less without using a thick urethane foam layer or the like, the flexibility of sinking fingers when holding the ball is suppressed. The Moreover, the surface close | similar to the tactile sensation of the skin material of cowhide by arranging the 1st layer containing the 1st polymer elastic body of the low modulus whose 100% modulus is 4-8 Mpa as a surface resin layer near the surface Surface tactile sensation such as sticking to can be expressed. The first layer also suppresses wrinkles from occurring when sewing the skin material. Further, since the second layer including the second high modulus elastic polymer body is provided on the surface side of the ball, the wear resistance is not lowered even if the first layer is provided.

  Further, in the plane direction, the tear strength is 150 N or more in any of the first direction, the second direction perpendicular to the first direction, and the third direction intersecting the first direction at 45 degrees, And it is preferable that 20% strength is 50 N / 25 mm or more. The skin material covered with the thread covering the outer periphery of the core sphere has a problem that the seam portion expands due to the tension of the thread to be stitched or tears from the stitch stitched with the thread. If the tear material is torn from the seam or the skin material itself is extended under the tension of the thread, the skin material itself is damaged. If the thread is damaged and frayed or cut before the skin material itself is damaged, it can be repaired by sewing the skin material again with a new thread. If the skin material itself is damaged, it is difficult to obtain the original characteristics even if the skin material is repaired again with a new thread. In such a case, by adjusting the properties and orientation of the fiber, the tensile strength and tear strength can be made uniform in all directions, higher than the tension of the yarn used for sewing the ball. Losing the skin material itself is prevented from being damaged.

  Moreover, the grip feeling can be adjusted by further laminating an outermost layer having a thickness of 0.001 to 2 μm including a third polymer elastic body having a 100% modulus of 0.5 to 4 MPa.

  The ball according to the present invention is a ball comprising a core sphere and a plurality of skin materials that are stitched with a thread that covers the outer periphery of the core sphere, and the skin material is any one of the above-described skin materials for a ball. It is. Such a ball has a feeling that the finger sinks when the pitcher grasps the ball, and it is high while maintaining a surface feel that sticks to the surface close to that of the cowhide skin material. Maintains wear resistance.

  Further, in the plane direction, the tear strength is 150 N or more in any of the first direction, the second direction perpendicular to the first direction, and the third direction intersecting the first direction at 45 degrees, In addition, when the above-mentioned ball skin material having a 20% strength of 50 N / 25 mm or more is used and sutured with a thread having a tensile strength of 100 to 150 N, the skin material itself is damaged by the tension of the thread. A ball in which is suppressed is obtained.

  According to the present invention, the feeling that the finger sinks when the pitcher grips the ball is suppressed, and high wear resistance is maintained while maintaining the surface feel that sticks to the surface close to the feel of the cowhide skin material. A ball using an artificial leather skin material holding

FIG. 1 is a schematic cross-sectional view for explaining a layer structure of a ball skin material 10 of an embodiment of a ball skin material according to the present invention. FIG. 2 is an explanatory diagram for explaining a state in which the web is folded at a predetermined folding angle α.

  A ball skin material 10 according to an embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a schematic cross-sectional view of a ball skin material 10 according to an embodiment. 1 is a fiber base material including a non-woven fabric containing ultrafine fibers having a fineness of 0.5 dtex or less and a polymer elastic body impregnated in the non-woven fabric. It is. Reference numeral 2 denotes a surface resin layer including a first layer 3 having a thickness of 10 to 50 μm and a second layer 4 having a thickness of 10 to 20 μm. Reference numeral 5 denotes an adhesive layer 5 that bonds the surface resin layer 2 and the fiber base material 1 together. The surface resin layer 2 is a layer that imparts durability, such as wear resistance, to the ball skin material 10 and an appearance and texture similar to cowhide. Further, an outermost layer 6 having a thickness of 0.001 to 2 μm for adjusting the grip feeling may be further laminated on the surface of the surface resin layer 2 in order to adjust the grip feeling as necessary.

  The second layer 4 is arranged on the surface side of the ball, and includes a high elastic layer containing 50 to 90% by mass of a second polymer elastic body having a 100% modulus of 10 to 15 MPa and 10 to 50% by mass of inorganic particles. It is. The first layer 3 contains 5 to 90% by mass of a first polymer elastic body having a 100% modulus of 4 to 8 MPa and 10 to 50% by mass of inorganic particles, which are arranged on the core ball side of the ball. It is a low elastic layer. Further, the outermost layer 6 includes a third polymer elastic body having a 100% modulus of 0.5 to 4 MPa.

  Hereinafter, each element of the skin material for balls will be described in detail.

  The fiber base material includes a non-woven fabric containing ultrafine fibers having a fineness of 0.5 dtex or less and a polymer elastic body impregnated in the non-woven fabric. According to the non-woven fabric containing ultrafine fibers having a fineness of 0.5 dtex or less, a dense and smooth surface having low uniformity of fibers and high homogeneity, such as a surface layer containing collagen fibers contained in cowhide, can be obtained. . By using such a fiber base material, it is possible to suppress a feeling that a finger sinks when the pitcher holds the ball. In addition, when a non-woven fabric of ultrafine fibers is used, a smooth surface can be formed only by the non-woven fabric, so that it is formed by fibers on the surface, as in the case of using a non-woven fabric made of fibers with high fineness. A smooth surface can be obtained without a thick urethane foam layer or the like for smoothing the unevenness.

  The nonwoven fabric of ultrafine fibers can be obtained by, for example, entanglement treatment of ultrafine fiber generating fibers such as sea-island type composite fibers to form a fiber entangled body, and then subject the fibers to ultrafine fiber treatment. In the present embodiment, the case where the sea-island type composite fiber is used will be described in detail. However, even if an ultrafine fiber-generating fiber other than the sea-island type composite fiber is used, it is directly used without using the ultrafine fiber-generating fiber. Ultra fine fibers may be spun. In addition, as a specific example of the ultrafine fiber generation type fiber other than the sea-island type composite fiber, a plurality of ultrafine fibers are formed by lightly bonding immediately after spinning, and a plurality of ultrafine fibers are formed by unraveling by mechanical operation. Such as a split-divided fiber, or a petal-type fiber in which a plurality of resins are alternately gathered in a petal shape in the melt spinning process, and any fiber that can form ultrafine fibers is used without particular limitation. It is done.

  For example, the sea-island type composite fiber can be prepared by mixing and melting two types of incompatible polymers and discharging them from a spinneret or by melting two types of incompatible polymers separately. Spinning is performed by a composite spinning method in which the melt is joined by a spinneret and discharged. And the sea component of the obtained sea-island type composite fiber is dissolved or decomposed and removed to form a fiber bundle-like ultrafine fiber. The number of islands in the cross section of the sea-island composite fiber is preferably 5 to 70, more preferably 15 to 50, and the mass ratio of the sea component to the island component is 10:90 to 70:30. preferable.

  The ultrafine fiber is made of a resin that forms the island component of the sea-island type composite fiber. Specific examples of the resin that forms the island component include, for example, polyamides such as polyamide 6, polyamide 66, polyamide 610, and polyamide 612; polyesters such as polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; acrylic polymers; Is mentioned. Among these, polyamide 6 and polyethylene terephthalate are particularly preferable from the viewpoint of excellent durability. Specific examples of the resin forming the sea component include polyethylene, polystyrene, copolymer polyester, thermoplastic polyvinyl alcohol, and the like.

  The fineness of the ultrafine fiber is 0.5 dtex or less, preferably 0.0001 to 0.5 dtex, more preferably 0.0001 to 0.2 dtex. When it exceeds 0.5 dtex, the surface smoothness decreases. Moreover, when it is less than 0.0001 dtex, mass productivity tends to be lowered.

  The nonwoven fabric of ultrafine fibers in this embodiment is a nonwoven fabric of ultrafine fibers of long fibers. Such a nonwoven fabric of ultrafine fibers of long fibers is preferably produced through a long fiber web of sea-island type composite fibers. Since the fiber entangled body of long ultrafine fibers can be dense in fiber density and can form high entanglement, high tensile strength and tear strength can be obtained.

The long island web of sea-island type composite fibers is preferably formed by a so-called spunbond method. Specifically, for example, after the web is pulled and refined at a speed of 2000 to 5000 m / min by a suction device such as an air jet nozzle, a molten polymer for forming a sea-island type composite fiber discharged from a spinneret is used. The web is formed by depositing on a movable collecting surface while opening the fiber. The basis weight of the web is preferably about ²⁰ to 50 g / m ² , for example.

  In addition, a long fiber means a continuous fiber that is not a short fiber intentionally cut after spinning. More specifically, for example, it means a fiber not derived from a short fiber intentionally cut so that the fiber length is about 3 to 80 mm. It is preferable that the fiber length of the sea-island type composite fiber before the ultrafine fiber formation is 100 mm or more, and it can be technically manufactured and unavoidably cut in the manufacturing process. The fiber length may be km or more. In addition, a part of long fiber may be inevitably cut | disconnected and become a short fiber in a manufacturing process by the needle punch at the time of the entanglement mentioned later, or buffing of the surface.

And after obtaining the stacked web which laminated | stacked the several layer web, the fiber entanglement of a sea-island type composite fiber is obtained by performing a three-dimensional entanglement process by a needle punch process, a high-pressure water flow, etc. In the case of the needle punching process, for example, it is preferable to carry out under the condition that at least one barb penetrates from both sides simultaneously or alternately. The punching density is not particularly limited, but is preferably in the range of 300 to 5000 punch / cm ² , more preferably in the range of 500 to 3500 punch / cm ² .

  In addition, when forming a stacked web by laminating webs, as shown in FIG. 2, a web 11 formed by a spunbond method is formed in a predetermined direction along the MD direction parallel to the traveling direction of the production line. It is preferable to fold the sheet so as to have a predetermined number of layers for each folding angle α and a predetermined interval from the viewpoint of suppressing anisotropy of tensile strength and tear strength. The folding angle α is an acute angle formed by the axis 12 parallel to the MD direction of the long fiber web 11 and the axis 13 parallel to the fold of the web 11 as shown in FIG. By such a process, a stacked web in which the webs are folded and stacked so as to overlap a plurality of layers is obtained.

  The web folding angle α is appropriately adjusted in order to adjust the orientation characteristics. Specifically, the folding angle α is preferably less than 90 degrees, preferably 75 to 89 degrees, more preferably 78 to 88 degrees, and particularly preferably 80 to 87 degrees. Further, the folding interval and the number of layers are appropriately selected in order to adjust the desired basis weight and density. Although the folding interval is not particularly limited, it is about 30 to 250 mm, further about 60 to 200 mm, and the number of laminated layers is appropriately adjusted according to the basis weight, for example, 5 to 40 layers, further 8 to 30 layers It is preferable that it is a grade.

  Moreover, it is preferable that the stacked web is subjected to a widening process (drawing out) for applying a tension in the width direction while being heat-treated in order to relax the anisotropy of mechanical properties. Such a widening treatment can improve the tensile strength and tear strength in the width direction. The extending ratio of the widening process is not particularly limited, but is preferably 5% or more, and more preferably 10% or more.

The web formed in this manner is entangled three-dimensionally by needle punching or high-pressure water flow, thereby obtaining a fiber entanglement of sea-island type composite fibers. In the case of the needle punching process, for example, it is preferable to carry out under the condition that at least one barb penetrates from both sides simultaneously or alternately. The punching density is not particularly limited, but is preferably in the range of 300 to 5000 punch / cm ² , more preferably in the range of 500 to 3500 punch / cm ² . The basis weight of the sea-entangled composite fiber fiber entanglement is not particularly limited, but is preferably 300 to 2000 g / m ² .

  Next, a polymer elastic body is impregnated into the fiber entanglement of the sea-island type composite fiber. Examples of the method of impregnating the fiber entanglement of the sea-island type composite fiber with the polymer elastic body include, for example, impregnating the fiber entanglement of the sea-island type composite fiber with the solution or dispersion of the polymer elastic body, The method of coagulating can be mentioned. The impregnation of the polymer elastic body may be performed before the ultrafine fiber treatment of the sea-island type composite fiber, after the ultrafine fiber treatment, or before and after the ultrafine fiber treatment. In particular, it is performed before the ultra-fine fiber treatment of the sea-island type composite fiber. By forming a void in the portion where the sea component after the ultra-fine fiber is removed, the fiber base material has a moderately supple feel. It is preferable because it can be maintained.

  The type of the polymer elastic body is not particularly limited. Specifically, for example, an acrylic elastic body such as polyurethane, acrylonitrile-butadiene copolymer, acrylic acid ester or methacrylic acid ester copolymer, or polyamide elastic body. And various polymer elastic bodies such as silicone rubber. Among these, polyurethane is particularly preferable from the viewpoint that a good texture can be obtained. In addition, the soft segment of polyurethane is selected from one or more types from among polyester units, polyether units, and polycarbonate units. The polymer elastic bodies may be used alone or in combination of two or more. Moreover, you may contain a pigment, dye, a coagulation regulator, a stabilizer, etc. as needed.

  The solvent or dispersion medium for adjusting the solution or dispersion of the polymer elastic body is not particularly limited. Specifically, it may be an organic solvent such as N, N-dimethylformamide (DMF), acetone, methyl ethyl ketone, tetrahydrofuran, or an aqueous solvent. Among these, DMF is particularly preferable because it is a good solvent for polyurethane and has excellent wet coagulation properties. An entangled nonwoven fabric is impregnated with such a solution or dispersion of a polymer elastic body and immersed in a water bath at a liquid temperature of 25 to 70 ° C. or in a mixed liquid bath of a good solvent for polymer elastic body and water. Thus, the polymer elastic body can be wet-solidified. Such a polymer elastic body is preferably porous.

  The content ratio of the polymer elastic body is such that the mass ratio of the fiber forming the nonwoven fabric to the polymer elastic body (fiber / polymer elastic body) is 40/60 to 70/30, and further 50/50 to 60 / A range of 40 is preferred. If the proportion of the polymer elastic body is too high, the resulting ball skin material tends to have a rubber-like hard texture. If the proportion of the polymer elastic body is too low, the resulting ball skin material There is a tendency that the form stability is lowered, and it becomes easy to stretch under the tension of the thread to be sewn.

  By applying the ultrafine fiber treatment to the fiber entanglement of the sea-island composite fiber, a nonwoven fabric that is a fiber entanglement of fiber bundles of ultrafine fibers is formed. The ultrafine fiber treatment may be performed at any stage before or after applying the polymer elastic body. By immersing the fiber entanglement of the sea-island type composite fiber in a solvent or a decomposing agent that selectively removes the sea component for a predetermined time to selectively remove the sea component, the sea-island type composite fiber becomes a fiber bundle. Converted to extra fine fibers. For example, when the island component is polyamide or polyethylene terephthalate and the sea component is polyethylene, toluene, trichloroethylene, tetrachloroethylene, or the like can be preferably used as the solvent. Further, when the island component is polyamide or polyethylene terephthalate and the sea component is an easily alkali-decomposable modified polyester, an aqueous caustic soda solution or the like can be preferably used as the decomposing agent. By such treatment, the sea component is removed from the fiber entangled body of the sea-island type composite fiber, and the nonwoven fabric that is the fiber entangled body of the ultrafine fiber is obtained.

  The ultra-fine fibers formed from the sea-island type composite fibers, for example, that 5 to 70 fibers are present in a bundle form have high tensile strength and tearing strength, and depending on the tension of the thread for sewing the resulting skin material for balls. Is preferable because it is difficult to stretch. The number of ultrafine fibers forming a bundle is more preferably 10-50.

  An oil agent such as a silicon-based oil agent may be applied to the nonwoven fabric, which is a fiber entangled body of ultrafine fibers formed in this manner, for the purpose of controlling the friction coefficient between fibers as necessary. Examples of the application method include a method of forcibly impregnating an aqueous solution or aqueous dispersion of an oil agent by dipping and niping, a method of spraying and penetrating with a spray, a method of imprinting and penetrating with a bar coater, knife coater, comma coater, etc. The method which combined these methods is mentioned. In addition, the front and back surfaces may be buffed to smooth the surface.

  In this way, a fiber base material obtained by impregnating a non-woven fabric of ultrafine fibers with a polymer elastic body is obtained. Although the thickness of a fiber base material is not specifically limited, It is preferable that it is 800-2000 micrometers, Furthermore, it is 1000-1500 micrometers. If the fiber substrate is too thin, wrinkles tend to occur during sewing, and if it is too thick, it tends to be too heavy and easily deviate from the standards defined in the baseball rules.

The apparent density of the nonwoven fabric itself that does not contain a polymer elastic body is preferably 0.2 to 0.6 g / cm ³ , more preferably 0.25 to 0.4 g / cm ³ . If the apparent density of the nonwoven fabric itself is too low, irregularities derived from the shape of the fiber tend to appear on the surface, and high tensile strength and tear strength tend to be difficult to obtain. As the apparent density of the fiber base material, 0.4 to 0.8 g / cm ^3, preferably further is 0.5~0.7g / cm ^3. When the apparent density of the fiber substrate is too low, high tensile strength and tear strength tend to be difficult to obtain. Moreover, when the apparent density of a fiber base material is too high, there exists a tendency for the sewing property of a skin material to also fall.

  As shown in FIG. 1, the ball skin material 10 in the present embodiment includes a fiber base material 1 including a first layer 3 having a thickness of 10 to 50 μm and a second layer 4 having a thickness of 10 to 20 μm. The resin layer 2 is bonded via the adhesive layer 5. Furthermore, on the surface of the surface resin layer 2, an outermost layer having a thickness of 0.001 to 2 μm including a third polymer elastic body having a 100% modulus of 0.5 to 4 MPa may be further laminated.

  The second layer is a layer that becomes a substantial skin of the ball skin material and imparts wear resistance to the ball surface, and a second polymer elastic body having a 100% modulus of 10 to 15 MPa and a mass of 50 to 90 mass. % And a high elastic layer having a thickness of 10 to 20 μm containing 10 to 50% by mass of inorganic particles. On the other hand, the first layer is a layer that expresses a surface tactile sensation that sticks to the surface close to the tactile sensation of the cowhide skin material, and suppresses wrinkles during sewing, and the 100% modulus is 4 to 8 MPa. A low elastic layer having a thickness of 10 to 50 μm and containing 50 to 90% by mass of the first polymer elastic body and 10 to 50% by mass of inorganic particles. In addition, when the second layer, which is a high elastic layer, is laminated on a fiber base material without the first layer, which is a low elastic layer, wrinkles easily occur during sewing, and the surface resin layer It becomes too hard and difficult to sew.

  The second layer contains 50 to 90% by mass of the second polymer elastic body. The 100% modulus of the second polymer elastic body is 10 to 15 MPa, and preferably 11 to 13 MPa. When the 100% modulus of the second polymer elastic body exceeds 15 MPa, the surface resin layer becomes too hard and the surface feel that sticks to the surface close to the feel of the cowhide skin material decreases, and sewing Sometimes it becomes easy to get cocoons. Further, when the 100% modulus of the second polymer elastic body is less than 10 MPa, the wear resistance is lowered.

  The thickness of the second layer is 10 to 20 μm, preferably 12 to 18 μm, and more preferably 14 to 16 μm. When the thickness of the second layer is less than 10 μm, the influence of the first layer which is a low elastic layer is increased, and the wear resistance is lowered. In addition, when the thickness of the second layer exceeds 20 μm, the surface resin layer becomes too hard and the surface feel that sticks to the surface close to the feel of the cowhide skin material is reduced. Is easier to enter.

  The first layer contains 50 to 90% by mass of the first polymer elastic body. The 100% modulus of the first polymer elastic body is 4 to 8 MPa, and preferably 5 to 7 MPa. When the 100% modulus of the first polymer elastic body exceeds 8 MPa, the surface resin layer becomes too hard and the surface feel that sticks to the surface close to the feel of the cowhide skin material decreases, and sewing Sometimes it becomes easy to get cocoons. Further, when the 100% modulus of the first polymer elastic body is less than 4 MPa, the wear resistance is lowered.

  The thickness of the first layer is 10 to 50 μm, preferably 15 to 30 μm, and more preferably 20 to 25 μm. When the thickness of the first layer is less than 10 μm, the surface feel that sticks to the surface close to the feel of the cowhide skin material is lowered. In addition, the second layer alone provides a resin-like feel when the ball is gripped, and the difference from the tactile feel of cowhide increases. In addition, when the thickness of the first layer exceeds 50 μm, it tends to be heavier than the weight of the cowhide skin, and it is likely to deviate from the standard set by the baseball rules, or the difference from the tactile feel of the leather.

  The polymer elastic body for forming the first layer and the second layer is not particularly limited as long as it is a polymer elastic body having 100% modulus defined as described above. Examples of the type of polymer elastic resin include various polymer elastic bodies such as polyurethane, acrylic elastic bodies, polyamide elastic bodies, and silicone rubber. These may be used alone or in combination of two or more. Among these, polyurethane is preferable from the viewpoint that a texture similar to cowhide is obtained and mechanical properties such as wear resistance and strength are excellent. The 100% modulus of the polymer elastic body can be adjusted as appropriate by selecting the type of resin and adjusting the crosslinking density. In addition, in the polyurethane, a polyether-based polyurethane having excellent abrasion resistance is used for the second layer, and a polycarbonate-based polyurethane having excellent weather resistance, abrasion resistance, and oil resistance is used for the first layer. Particularly preferred. In addition, the polymer elastic body for forming the first layer and the second layer is particularly preferably a non-porous polymer elastic body from the viewpoint of maintaining high wear resistance.

  As the polyurethane, a two-component polyurethane is preferably used. The crosslinking agent for crosslinking the two-component polyurethane is not particularly limited as long as it is a known crosslinking agent. Specific examples thereof include epoxy compounds, aziridine compounds, carbodiimide compounds, organic polyisocyanate compounds, oxazoline compounds, melamine formamide compounds, urea methylol compounds, and the like. The mass ratio between the polyurethane and the cross-linking agent is preferably 50/1 to 50/10, more preferably 50/2 to 50/7, since it hardly swells when wet and is excellent in texture.

  The 1st layer and the 2nd layer contain 10-50 mass% of inorganic particles, respectively. Such inorganic particles are blended for the purpose of concealing the appearance of the fiber substrate. Specific examples of such inorganic particles include, for example, white pigments such as titanium oxide, black pigments such as carbon black, and other inorganic particles such as iron oxide and silica, which are suitable for the purpose. Is blended. In addition, since a general hard baseball is white, titanium oxide is preferably used as a skin material of a general hard baseball.

  The ratio of the inorganic particles contained in each of the first layer and the second layer is 10 to 50% by mass, preferably 20 to 40% by weight, and more preferably 25 to 35% by weight. When the ratio of the inorganic particles contained in each of the first layer and the second layer is less than 10% by mass, the fiber base material cannot be sufficiently concealed. Moreover, when the ratio of the inorganic particle contained in each of the 1st layer and the 2nd layer exceeds 50 mass%, a surface resin layer becomes hard and becomes brittle, and abrasion resistance falls.

  The surface resin layer including the first layer and the second layer as described above is, for example, for forming a surface resin layer including the first layer and the second layer on a release paper by a dry-type surface. A film is formed, and further, an adhesive layer is formed on the film and adhered to the surface of the fiber substrate, and then the release paper is peeled off. Further, when a release paper having pore-like irregularities is used as the release paper, for example, an appearance closer to cowhide can be obtained, and grip properties are also improved. Note that any of the first layer, the second layer, the outermost layer, and the adhesive layer is preferably a nonporous layer in order to suppress water permeation and surface wear.

  The thickness of the adhesive layer that bonds the surface resin layer and the fiber substrate is 100 μm or less, preferably 30 to 100 μm, and more preferably 40 to 60 μm. As the kind of the adhesive that forms the adhesive layer, various polymer elastic adhesives such as polyurethane adhesives, acrylic adhesives, polyamide adhesives, and silicone rubber adhesives are preferably used. Of these, polyurethane adhesives, particularly crosslinkable polyurethane adhesives are preferred. Since the adhesive layer formed from a crosslinkable polyurethane adhesive does not easily swell in water, it must maintain high adhesion to the surface resin layer even when balls are used under harsh conditions such as getting wet. Can do.

  Moreover, it is preferable that an outermost layer having a thickness of 0.001 to 2 μm including a third polymer elastic body having a 100% modulus of 0.5 to 4 MPa is further laminated on the surface of the surface resin layer. By further laminating such an outermost layer having a particularly low 100% modulus, the grip feeling of the ball can be improved. The polymer elastic body for forming such an outermost layer is not particularly limited as long as it is a polymer elastic body having a 100% modulus of 0.5 to 4 MPa. Examples of such a polymer elastic resin include polyurethane resins, rubber resins, petroleum hydrocarbon resins, and the like.

  The thickness of the outermost layer is preferably 0.001 to 2 μm, more preferably 0.01 to 1 μm, and particularly preferably 0.1 to 1 μm. When the thickness of the outermost layer is too thick, the grip feeling on the surface tends to be too high, and when it is too thin, the effect of improving the grip feeling tends to be insufficient.

  Each of the above-mentioned layers is blended with other pigments, fillers, light stabilizers, antioxidants, ultraviolet absorbers, fluorescent agents, and other additives as necessary, as long as the effects of the present invention are not impaired. May be.

  In addition, all the thickness of each layer mentioned above is average thickness. The surface resin layer of the skin material may have irregularities formed using, for example, release paper having pore-like irregularities, and irregularities derived from the fiber shape of the fiber base material. Therefore, the thickness of each layer is a value obtained by calculating the average of the film thicknesses of at least 30 points selected at random, as will be described later.

  The total thickness of the surface layer and the adhesive layer is preferably 50 to 120 μm, more preferably 60 to 80 μm. If the total thickness of the surface layer and adhesive layer is too thick, it will tend to be heavier than the weight of the cowhide skin. In this case, when the standard is not set by the baseball rules or the pitcher holds the ball There is a tendency that the feeling that the finger of the sun goes down becomes large.

  In addition, the thickness ratio of the second layer to the first layer (second layer / first layer) is 0.2 to 1.0, more preferably 0.3 to 0.6 at the time of sewing. It is preferable from the viewpoint that wrinkles are not easily generated and that a tactile sensation closer to a ball using a leather skin material is obtained.

  In this way, the skin material of the present embodiment is obtained. In addition, the skin material may be subjected to a known scouring treatment as necessary before or after the surface resin layer is formed, or before and after the formation. By the kneading process, it is possible to give a kneading wrinkle similar to flexibility and cowhide. For the stagnation treatment, known means such as a high-pressure liquid flow dyeing machine, a wins, a tumbler, and a mechanical stagnation machine can be used.

  The thickness of the skin material thus obtained is preferably 800 to 2000 μm, more preferably 1000 to 1500 μm. If the thickness of the skin material is too thin, large wrinkles are likely to occur during sewing, and if it is too thick, it tends to be too heavy and easily deviate from the standards defined in the baseball rules.

  Further, the skin material of the present embodiment, in the surface direction, in any direction of the first direction, the second direction orthogonal to the first direction, and the third direction intersecting the first direction at 45 degrees, It is preferable that the tear strength is 120 N or more, particularly 150 N or more, more preferably 170 N or more, and the 20% strength is 50 N / 25 mm or more, more preferably 65 N / 25 mm or more. In a conventional artificial leather skin material, when stitched with a thread, the seam portion may expand due to the tension of the stitched thread, or may tear from the stitch during use. If the skin material is torn or the skin material itself extends and loses the tension of the thread, the skin material itself is damaged. If the yarn frays or breaks before the skin material itself is damaged, the skin material can be repaired by sewing again with a new thread. However, when the skin material itself is damaged, it is difficult to obtain the original characteristics even if the skin material is repaired again with a new thread. In such a case, the skin material itself can be damaged by losing the tension of the thread by adjusting it to have a tensile strength higher than that of a general thread used for ball stitching in any direction. Is suppressed.

  The skin material thus obtained is preferably used as a skin material for hard baseballs such as baseball and softball. Such a skin material is used instead of leather when a ball is manufactured using a known manufacturing method such as a hard baseball. Specifically, a core of a core consisting of a cork core and a rubber layer is wrapped with two ball skin materials obtained by cutting the core ball around the core ball formed into a predetermined shape. For example, 108 seams can be sewn together with a sewing thread.

  In the case of a hard baseball for game using leather, a natural thread such as cotton thread is generally used as a sewing thread, but there is a problem that the natural thread is easily frayed due to wear. In the case of a ball obtained using the skin material of the present embodiment, a sewing thread made of a synthetic resin having high wear resistance and high strength such as a thread of an aromatic polyamide resin fiber may be used. For example, a ball for practicing a batting used only for a pitching machine is likely to be worn and frayed by the foil of the pitching machine, and is frequently used. Therefore, it is required to maintain high durability for a long period of time. In such an application, high durability can be maintained for a long time by using a sewing thread made of a synthetic resin such as an aromatic polyamide resin. For balls used for ground practice, durability is improved by blending cotton yarn with aromatic polyamide resin fiber yarn, for example, using about half of the yarn as aromatic polyamide resin fiber yarn. As a result, fraying and the like due to abrasion with the earth and sand can be suppressed.

  The tensile strength of cotton yarn is usually about 60-80N. The tensile strength of the aromatic polyamide resin fiber yarn is about 130N to 140N. Therefore, the tensile strength can be adjusted in the range of about 60 to 140 N by blending them at a predetermined ratio. For example, when cotton yarn and aromatic polyamide resin fiber are blended in the same amount, the tensile strength can be adjusted to about 100 to 110N.

  When a sewing thread having a high tensile strength as described above is used, the surface of the skin material is likely to spread due to the tension of the thread to be sewn or torn from the seam sewn with the thread. Such a problem occurs in all directions of the first direction, the second direction perpendicular to the first direction, and the third direction intersecting the first direction at 45 degrees as described above. This can be solved by using a skin material having a strength higher than the tensile strength of the sewing thread. Specifically, for example, when using a sewing thread having a tensile strength of about 100 to 110 N, in the surface direction, the first direction intersects with the second direction orthogonal to the first direction at 45 degrees. In all directions of the third direction, by using the above-described skin material having a tear strength of 120 N or more and a 20% strength of 50 N / 25 mm or more, the skin material is damaged by the tension of the yarn. It becomes easy to be suppressed. In order to prevent tearing from a stitch stitched with a sewing thread having a tensile strength of about 100 to 110 N, the tear strength of the skin material is particularly preferably 150 N or more.

  EXAMPLES Next, although an Example demonstrates this invention in detail, the scope of the present invention is not limited to the following Example. In addition, unless otherwise indicated, the part and% in an Example are related with mass. Various characteristics were measured by the following methods.

(1) Fineness of extra fine fibers An arbitrary cross section parallel to the thickness direction of the obtained ball skin material was observed with a scanning electron microscope (SEM) at a magnification of about 100 to 300 times. Then, 20 ultra-long fiber bundles oriented almost perpendicularly to the cross section from the observation field were randomly selected. Subsequently, the cross section of each selected ultrafine fiber bundle was enlarged to a magnification of about 1000 to 3000 times, and the average value of the cross-sectional areas of the ultrafine fibers was obtained. The fineness of the ultrafine fibers was determined from the cross-sectional area obtained and the specific gravity of the resin forming the ultrafine fibers.

(2) 100% Modulus of Resin Forming Each Layer of Surface Resin Layer A film having a thickness of 50 to 100 μm of the polymer elastic body used for forming each layer was produced. A test piece of 2.5 cm × 16 cm was prepared from this film, and a stress-strain curve was obtained according to the measuring method described in 8.12.1 “Tensile strength test” of JIS L1096. Then, the stress at 100% elongation was read from the stress-strain curve, and the 100% modulus was obtained.

(3) Thickness of each layer of surface resin layer An arbitrary cross section parallel to the thickness direction of the obtained skin material for a ball was observed with a SEM at 300 times. And the film thickness of 30 places chosen at random was measured and the average value was calculated | required.

(4) 20% strength of ball skin material Using a 2.5 cm × 16 cm test piece cut out from the obtained ball skin material, stress was applied according to 8.12.1 “Tensile strength test” of JIS L1096. -A strain curve was obtained. And the stress when it extended 20% from a stress-strain curve was read, and 20% strength was calculated | required.

(5) Tearing strength of the skin material for balls Using a 4 cm × 10 cm test piece cut out from the obtained skin material for balls, JIS L1096 8.15.1 A-1 method (single tongue) “Tearing strength test According to the above, the load when tearing the skin material for balls was measured to determine the tear strength. In addition, a test piece is prepared for each direction of any one direction, a direction rotated by 45 degrees with respect to that direction, and a direction rotated by 90 degrees with respect to that direction for each skin material for the ball. Each was evaluated.

(6) Flexibility of the surface of the ball skin material Although it is difficult to quantitatively determine the tactile sensation when the ball is gripped, there is some correlation with the softness of the surface of the ball skin material. If the surface is hard, the feeling of sticking cannot be obtained. The surface flexibility of the ball skin material was evaluated using a soft tester used to measure leather flexibility as defined by ISO 17235: 2002 (IULTCS / IUP 36). Specifically, the skin material for the ball is fixed on a table with a metal 25 mm ring, and a metal pin with a diameter of 5 mm, to which a certain load is applied, is pushed down. The softer the leather, the deeper the pin penetrates. The greater the penetration depth, the greater the sensation of sticking when holding the ball.

(7) Tactile feel and feel of the ball The 10 baseball team pitchers used the ball as a pitching practice ball, and the difference in tactile sensation from the game ball made of cowhide was determined according to the following criteria. It was.
A: Seven or more people judged that the surface feels sticky and the feel when grasped is a ball close to the skin material of cowhide.
B: Five people had the same judgment as A, and five people had the same judgment as C.
C: Seven or more people judged that the surface feels sticky and the feel when grasped is a ball that is clearly different from the leather skin material.

(8) Abrasion resistance (Taber wear)
The weight loss due to Taber abrasion on the surface of the skin material was measured according to JIS K6264. In addition, it measured on the conditions of wear wheel: H-22, load: 4.9N, rotation speed 60rpm, 1000 times. The weight loss (mg), which is the difference between the mass before the abrasion test and the mass after the abrasion test, was determined.

(9) Sewing durability The obtained ball is used for about 6 hours per day for about 2 hours in practice at a university baseball club, and the condition near the seam of the skin of the ball after 2 months is as follows: Judged by the criteria of.
A: No tear occurred in the seam.
B: A tear occurred in the seam.

(10) Ease of Sewing Ease of sewing at the time of manufacturing the ball was determined according to the following criteria A: The needle hole of the seam was not opened, and the appearance was beautiful.
B: The needle hole of the seam spread in an elliptical shape, and the appearance was not beautiful.

(11) Generation of wrinkles at the time of sewing The occurrence of wrinkles at the time of sewing was determined based on the following criteria A: No wrinkles were formed at the stitches, and the appearance was beautiful.
B: A wrinkle entered the seam, and even if it was corrected, it did not look beautiful.

[Example 1]
Polyamide 6 as an island component and polyethylene as a sea component were melted in a single screw extruder, respectively, and sea island type composite fibers having a mass ratio of 50:50 and 25 islands were melt-spun from a composite spinning nozzle. Then, a long fiber web was formed by spraying the sea-island type composite fiber discharged from the composite spinning nozzle onto the collection net while stretching it with an air flow of 3500 m / min. The basis weight of the obtained web was 30 g / m ² , and the fineness of the sea-island type composite fiber was 2 dtex.

The obtained web was continuously folded at regular intervals so that the folding angle was 84 degrees with respect to the length direction of the web, and the web was stacked in 10 layers. The width was 176 cm and the basis weight was 593 g / m ^2. Got a stacked web. The resulting stacked web was subjected to a needle punching process of 1400 punch / cm ² using a 1 barb felt needle, and then subjected to a widening process by applying a tension in the width direction, thereby extending 10%. Then, an entangled nonwoven fabric made of long fibers of sea-island type composite fibers with a basis weight of 420 g / m ² and a thickness of 1.60 mm was obtained by passing between heated rolls and performing a heat press treatment.

Next, an entangled nonwoven fabric of sea-island type composite fibers was impregnated with an 18% DMF solution of polyester polyurethane, and wet coagulated into a porous state in water. Then, the sea-island type composite fiber was converted into ultra-long fibers by extracting and removing polyethylene, which is a sea component of the sea-island type composite fiber, with 95 ° C. toluene. In this manner, a fiber base material having a density of 0.36 g / cm ³ , a basis weight of 415 g / m ² , and a thickness of about 1150 μm, including a non-woven fabric of ultrafine fibers of 0.03 dtex and a polymer elastic body was obtained.

Subsequently, 100 parts by mass of polycarbonate-based polyurethane (NY-360: manufactured by DIC Corporation), 20 parts by mass of titanium oxide, 20 parts by mass of DMF, 10 parts by mass of isopropanol, 10 parts by mass of ethyl acetate, and burnock on the release paper having pores. The second layer was formed by applying a coating solution for forming the second layer, which was blended with 3 parts by mass of DN950 (a crosslinking agent manufactured by DIC Corporation) at a wet coating amount of 70 g / m ² and then drying. Formed. The second layer contains 32% by weight of titanium oxide. The crosslinked polycarbonate polyurethane had a 100% modulus of 11 MPa.

Next, on the surface of the second layer, 100 parts by mass of polyether-based polyurethane (ME8116: manufactured by Dainichi Seika Co., Ltd.), 30 parts by mass of titanium oxide, 30 parts by mass of DMF, 30 parts by mass of methyl ethyl ketone, NE crosslinking agent (large The first layer was formed by applying a coating solution for forming the first layer containing 3 parts by mass of Nissei Kasei Co., Ltd. at a wet coating amount of 105 g / m ² and then drying. The first layer contains 30% by weight of titanium oxide. The crosslinked polyether polyurethane had a 100% modulus of 7.5 MPa.

And on the surface of the first layer, 100 parts by mass of polyether polyurethane (UD-8310: manufactured by Dainichi Seika Kogyo Co., Ltd.), 10 parts by mass of cross-linking agent Takenate D110N (manufactured by Mitsui Chemicals, Inc.), crosslinking promotion After applying a coating solution for forming an adhesive layer containing 2 parts by weight of an agent (QS: Takeda Pharmaceutical Co., Ltd.), 15 parts by weight of DMF, and 15 parts by weight of ethyl acetate at a wet coating amount of 135 g / m ^2. In order to promote the cross-linking reaction of the adhesive layer in a dryer having an atmospheric temperature of 60 ° C., it is bonded to the surface of the fiber base material with the resin tack remaining after drying at 130 ° C. Time curing was performed. And the surface resin layer by which the contact bonding layer, the 1st layer, and the 2nd layer were laminated | stacked in order on the surface of the fiber base material was formed by peeling a release paper.

Next, in order to form the outermost layer, a polyurethane-based polyurethane resin having a 100% modulus of 0.7 MPa dissolved in toluene is used as a coating solution, and is applied with a gravure roll so that the solid content is 1 g / m ^2. did.

  In this manner, a ball skin material having a thickness of about 1240 μm was obtained. When the cross section of the obtained skin material for balls was observed with a scanning electron microscope (300 times), the film thicknesses of 30 locations selected at random were measured, and the average value was determined. The thickness of the second layer Was 15 μm, the thickness of the first layer was 23 μm, the thickness of the adhesive layer was 50 μm, and the thickness of the outermost layer was less than 1 μm.

  And the hard baseball used for practice was produced using the obtained skin material for balls. Specifically, a core material in which a woolen core is wound around a rubber core centered on a spherical cork is wrapped with a skin material for a ball cut to a predetermined size, and an aromatic polyamide having a fineness of 1815 dtex and a tensile strength of 137 N The ball skin material was stitched using a sewing needle so that 108 stitches were formed from a sewing thread having a tensile strength of 104 N, which is a blended yarn containing the same amount of resin fiber Kevlar (registered trademark). In this way, a hard baseball having a weight of 145 g and a circumference of 230 cm was obtained.

  And the characteristic of the obtained skin material for balls and the hard baseball was evaluated by the evaluation method described above. Table 1 shows the characteristics of the hard baseball and the evaluation results.

[Example 2]
In Example 1, a skin material and a ball were produced and evaluated in the same manner as in Example 1 except that the thickness of the first layer was changed to 15 μm instead of 23 μm. The results are shown in Table 1.

[Example 3]
In Example 1, skin materials and balls were produced and evaluated in the same manner as in Example 1 except that the thickness of the first layer was changed to 50 μm instead of 23 μm. The results are shown in Table 1.

[Example 4]
In Example 1, the same procedure as in Example 1 was performed except that the polyether-based polyurethane having a 100% modulus of 4 MPa was used instead of the polyether-based polyurethane having a 100% modulus of 7.5 MPa in the first layer. Skin materials and balls were manufactured and evaluated. The results are shown in Table 1.

[Example 5]
In Example 1, in place of the polycarbonate-based polyurethane in which the 100% modulus of the second layer is 11 MPa, the amount of the crosslinking agent is increased to change to a polycarbonate-based polyurethane in which the 100% modulus is 15 MPa. Thus, a skin material and a ball were manufactured and evaluated. The results are shown in Table 1.

[Example 6]
In Example 1, a skin material and a ball were manufactured and evaluated in the same manner as in Example 1 except that the thickness of the second layer was changed to 12 μm instead of 15 μm. The results are shown in Table 1.

[Example 7]
In Example 1, a skin material and balls were produced and evaluated in the same manner as in Example 1 except that the thickness of the second layer was changed to 20 μm instead of 15 μm. The results are shown in Table 1.

[Example 8]
In Example 1, the obtained web was subjected to needle punching on the stacked web obtained by repeatedly folding the web at a constant interval so that the folding angle was 84 degrees with respect to the length direction of the web. By applying tension in the width direction and expanding the width, instead of performing 10% unwinding, the obtained web is spaced at a constant angle so that the folding angle is 84 degrees with respect to the length direction of the web. A skin material in the same manner as in Example 1 except that the stacked webs obtained by continuously repeating folding in the above were subjected to needle punching treatment, and were not subjected to tensioning in the width direction and were not carried out. And balls were manufactured and evaluated. The results are shown in Table 1.

[Example 9]
In Example 1, skin materials and balls were produced and evaluated in the same manner as in Example 1 except that the thickness of the adhesive layer was changed to 100 μm instead of 50 μm. The results are shown in Table 1.

[Comparative Example 1]
In Example 1, the thickness of the first layer was changed to 38 μm instead of 23 μm, and a skin material and a ball were manufactured and evaluated in the same manner as in Example 1 except that the second layer was not provided. did. The results are shown in Table 1.

[Comparative Example 2]
In Example 1, the thickness of the second layer was changed to 38 μm instead of 15 μm, and a skin material and a ball were manufactured and evaluated in the same manner as in Example 1 except that the first layer was not provided. did. The results are shown in Table 1.

[Comparative Example 3]
In Example 1, after forming an entangled nonwoven fabric of sea-island type composite fibers, instead of obtaining an ultrafine fiber nonwoven fabric by obtaining ultrafine fiber nonwoven fabric, a solid fiber nonwoven fabric having a fineness of 2 dtex was obtained, and the surface of the nonwoven fabric was smoothed A skin material and a ball were produced and evaluated in the same manner as in Example 1 except that a foamed layer having a thickness of 50 μm was provided. The results are shown in Table 1.

[Comparative Example 4]
In Example 1, instead of using a nonwoven fabric of ultrafine fibers of long fibers, needle punching was performed using a single fiber web formed by carding short fibers obtained by cutting sea-island composite fibers into 51 mm. A skin material and a ball were produced and evaluated in the same manner as in Example 1 except that a nonwoven fabric of ultrafine fibers of short fibers obtained through an entangled nonwoven fabric of short-sea sea-island composite fibers was used. The results are shown in Table 1.

  From the results of Table 1, the balls obtained in Examples 1 to 8 according to the present invention are all made of cowhide with a surface feel that more than 7 out of 10 stick and a feel when gripped. It was determined that the ball was close to the skin material. In addition, the surface of the skin material was excellent in wear resistance. On the other hand, the skin material obtained in Comparative Example 1 in which the second layer was not provided had low wear resistance. Further, the skin material obtained in Comparative Example 2 in which the first layer was not provided had low surface flexibility correlated with the surface tactile sensation, and the surface tactile sensation was also inferior. Further, the skin material obtained in Comparative Example 3 using a nonwoven fabric of 2 dtex fibers that is not ultrafine fibers required a urethane foam layer in order to smooth the surface of the nonwoven fabric. For this reason, there are many opinions that there is a feeling that sinks when grasped. More than 7 out of 10 people feel that the surface feel that sticks and the feel when grasped are clearly different from the leather skin material. Determined to be a ball. In addition, the skin material obtained in Comparative Example 4 using a single-fiber ultrafine fiber non-woven fabric in place of long-fiber ultrafine fibers has a particularly low 20% tensile strength and tear strength, and therefore has poor durability. The surface was not sufficiently densified, and the surface texture was poorly judged.

DESCRIPTION OF SYMBOLS 1 Fiber base material 2 Surface resin layer 3 1st layer 4 2nd layer 5 Adhesive layer 6 Outermost layer 10 Skin material for balls

Claims (6)

A skin material for the ball,
The skin material includes a non-woven fabric containing ultrafine fibers having a fineness of 0.5 dtex or less, a fiber base material including a polymer elastic body impregnated in the non-woven fabric, a surface resin layer, the surface resin layer, and the fiber base material. An adhesive layer having a thickness of 100 μm or less,
The surface resin layer includes a first layer having a thickness of 10 to 50 μm, and a second layer having a thickness of 10 to 20 μm disposed on the surface side of the ball with respect to the first layer,
The first layer contains 50 to 90% by mass of a first polymer elastic body having a 100% modulus of 4 to 8 MPa and 10 to 50% by mass of inorganic particles,
The skin material for balls, wherein the second layer contains 50 to 90% by mass of a second polymer elastic body having a 100% modulus of 10 to 15 MPa and 10 to 50% by mass of inorganic particles.   In the plane direction, the tear strength is 120 N or more in any of the first direction, the second direction orthogonal to the first direction, and the third direction intersecting the first direction at 45 degrees, And the skin material for balls according to claim 1 whose 20% strength is 50 N / 25mm or more.   The skin material for a ball according to claim 1 or 2, wherein a total thickness of the surface layer and the adhesive layer is 50 to 120 µm.   The ball according to any one of claims 1 to 3, wherein an outermost layer having a thickness of 0.001 to 2 µm and further including a third polymer elastic body having a 100% modulus of 0.5 to 4 MPa is further laminated. Skin material. A ball comprising a core ball and a plurality of skin materials that are sewn with a thread, covering the outer periphery of the core ball,
The said skin material is a skin material for balls of any one of Claims 1-4, The ball | bowl characterized by the above-mentioned.   The ball according to claim 5, wherein the ball skin material is the ball skin material according to claim 2, and the yarn is a yarn having a tensile strength of 60 to 140N.

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