Method for using mastitis prevention sheet, mastitis prevention sheet, and method for producing mastitis prevention sheet

Abstract

In the present invention, a mastitis prevention sheet for livestock includes a base material layer and an adhesive layer that contains chitosan and that is supported by the base material layer. In the adhesive layer, the surface opposite to the surface facing the base material layer is an adhesive surface. In the present invention, a method for using a mastitis prevention sheet comprises: causing a first portion of the adhesive surface to adhere to a second portion of the adhesive surface, whereby a mastitis prevention sheet is attached to a nipple so that the mastitis prevention sheet has a cylindrical shape surrounding the nipple; and causing the first portion of the adhesive surface to adhere to the second portion of the adhesive surface at a position set apart from the orifice of the nipple so as to close the cylindrical end of the mastitis prevention sheet.

Description

Method for using mastitis prevention sheet, mastitis prevention sheet, and method for manufacturing mastitis prevention sheet

[0001] The present disclosure relates to a method for using a mastitis prevention sheet, a mastitis prevention sheet, and a method for manufacturing a mastitis prevention sheet.

[0002] One example of a teat orifice protection patch for livestock includes a laminate of an elastic sheet and an adhesive layer laminated on a first surface of the elastic sheet. The tensile stress at double elongation of the laminate is in the range of 0.1 N or more and 5 N or less. The teat orifice protection patch further includes a protective film laminated on a second surface, which is the surface opposite to the first surface of the elastic sheet, and a release sheet attached to the adhesive layer. When the teat orifice protection patch is used, the release sheet is first peeled off from the adhesive layer. Next, the adhesive layer is attached to the teat so as to cover the teat orifice located at the tip of the teat. The protective sheet is then removed from the elastic sheet (see, for example, Patent Document 1).

[0003] International Publication No. 2017 / 150203

[0004] Incidentally, milk synthesized in the mammary gland is secreted from the nipple orifice. Therefore, when a nipple orifice protection patch is attached to the nipple so as to cover the nipple orifice, milk secreted from the nipple orifice gets into the gap between the nipple and the nipple orifice protection patch. This reduces the adhesiveness of the adhesive layer to the nipple, making the nipple orifice protection patch more likely to peel off from the nipple.

[0005] One aspect of a method for using a mastitis prevention sheet is a method for using a mastitis prevention sheet for livestock that has an antibacterial effect and includes a base layer and an adhesive layer that contains chitosan and is supported on the base layer. The adhesive layer has an adhesive surface on the side opposite to the surface facing the base layer. The method for using the mastitis prevention sheet includes attaching the mastitis prevention sheet to the teat so that the sheet has a tubular shape that surrounds the teat, and closely contacting a first portion of the adhesive surface with a second portion of the adhesive surface at a position away from the teat orifice of the teat so as to close the tubular end of the mastitis prevention sheet.

[0006] One aspect of the mastitis prevention sheet is an antibacterial mastitis prevention sheet comprising a base layer and an adhesive layer supported on the base layer, the adhesive layer having an adhesive surface on the side opposite to the surface facing the base layer, and the adhesive strength between a first portion of the adhesive surface and a second portion of the adhesive surface being 2 N / 25 mm or more and 10 N / 25 mm or less.

[0007] One aspect of the method for producing a mastitis prevention sheet is a method for producing an antibacterial mastitis prevention sheet for livestock, comprising a base layer and an adhesive layer containing chitosan and supported on the base layer. The method includes forming the base layer, forming the adhesive layer containing 2% by mass or more of chitosan, and having an adhesion strength of 2 N / 25 mm or more and 10 N / 25 mm or less between a first portion of the adhesive surface, which is the surface opposite to the surface facing the base layer, and a second portion of the adhesive surface, and bonding the adhesive layer to the base layer. Forming the adhesive layer includes using an acidic aqueous solution containing chitosan.

[0008] FIG. 1 is a cross-sectional view showing the structure of a mastitis prevention sheet. FIG. 2 is a plan view showing the structure of a mastitis prevention sheet. FIG. 3 is a plan view showing the structure of a first modified example of a mastitis prevention sheet. FIG. 4 is a plan view showing the structure of a second modified example of a mastitis prevention sheet. FIG. 5 is a plan view showing the structure of a third modified example of a mastitis prevention sheet. FIG. 6 is a process diagram showing one step included in a method of using a mastitis prevention sheet. FIG. 7 is a process diagram showing one step included in a method of using a mastitis prevention sheet. FIG. 8 is a process diagram showing one step included in a method of using a mastitis prevention sheet. FIG. 9 is a process diagram showing one step included in a method of using a mastitis prevention sheet. FIG. 10 is a process diagram showing one step included in a method of using a mastitis prevention sheet. FIG. 11 is a flowchart illustrating the step of forming a base layer included in the method of manufacturing a mastitis prevention sheet. FIG. 12 is a flowchart illustrating the step of forming an adhesive layer included in the method of manufacturing a mastitis prevention sheet. FIG. 13 is a flowchart showing the step of forming a mastitis prevention sheet included in the method of manufacturing a mastitis prevention sheet. FIG. 14 is a table showing the evaluation results of Test Example 1. FIG. 15 is a table showing the evaluation results of Test Example 2.

[0009] An embodiment of a method for using a mastitis prevention sheet, a mastitis prevention sheet, and a method for manufacturing a mastitis prevention sheet will be described with reference to Figures 1 to 15. [Mastitis prevention sheet] The mastitis prevention sheet will be described with reference to Figures 1 to 5. Figure 1 shows the cross-sectional structure of the mastitis prevention sheet along a plane perpendicular to the plane in which the mastitis prevention sheet spreads.

[0010] As shown in FIG. 1, the mastitis prevention sheet 10 comprises a base layer 11 and an adhesive layer 12 supported on the base layer 11. The mastitis prevention sheet 10 comprises a main sheet body 10B. The main sheet body 10B includes a base layer 11 and an adhesive layer 12. The mastitis prevention sheet 10 has an antibacterial effect. In the example shown in FIG. 1, the adhesive layer 12 is in contact with the base layer 11. A printed layer, for example, may be located between the adhesive layer 12 and the base layer 11. In the adhesive layer 12, the surface opposite to the surface facing the base layer 11 is the adhesive surface 12S. In the example shown in FIG. 1, the adhesive layer 12 is in contact with the base layer 11, and therefore the surface of the adhesive layer 12 opposite to the surface in contact with the base layer 11 is the adhesive surface 12S. The adhesive surface 12S is the surface that is attached to the teats of the livestock to which the mastitis prevention sheet 10 is to be attached. The livestock may be, for example, a dairy cow.

[0011] The mastitis prevention sheet 10 of the present disclosure satisfies the following conditions: (Condition 1) It contains 2% by mass or more of chitosan. (Condition 2) The adhesion strength between the first portion of the adhesive surface 12S and the second portion of the adhesive surface 12S is 2 N / 25 mm or more and 10 N / 25 mm or less.

[0012] Because the adhesive layer 12 contains 2% by mass or more of chitosan, the mastitis prevention sheet 10 has an antibacterial effect. Furthermore, because the adhesion strength when the first portion of the adhesive surface 12S is brought into close contact with the second portion is 2 N / 25 mm or more, the mastitis prevention sheet 10 can be attached to the nipple by the adhesion portion formed by the adhesion between the first and second portions. Furthermore, because the adhesion strength between the first and second portions of the adhesive surface 12S is 10 N / 25 mm or less, when the tubular end of the mastitis prevention sheet 10 is blocked below the nipple orifice, a space can be formed in which milk secreted from the nipple orifice can be collected.

[0013] The first portion of the adhesive surface 12S may be any area within the adhesive surface 12S, and the second portion may be an area different from the first portion and may be any area within the adhesive surface 12S other than the first portion.

[0014] The chitosan content in the adhesive layer 12 is preferably 5% by mass or less, from the viewpoint of reducing the amount of chitosan used while maintaining the antibacterial effect of chitosan. Therefore, the chitosan content in the adhesive layer 12 may be 2% by mass or more and 5% by mass or less. Alternatively, the chitosan content is preferably 5% by mass or more, from the viewpoint of maintaining a high level of antibacterial activity value of chitosan and reducing variation in antibacterial activity value due to variation in chitosan content. Therefore, the chitosan content in the adhesive layer 12 may be 5% by mass or more and 10% by mass or less. The chitosan content is the percentage of the mass of chitosan relative to the sum of the mass of the solids in the base agent used to form the adhesive layer 12, the mass of the solids in the curing agent used to form the adhesive layer 12, and the mass of chitosan.

[0015] The antibacterial effect of chitosan is confirmed by a method conforming to JIS Z 2801:2010 "Antibacterial processed products - Antibacterial test method, antibacterial effect." The adhesive strength of the adhesive layer 12 is a value measured by a tensile test conforming to JIS K 7127:1999 "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets."

[0016] 1, the adhesive layer 12 is in contact with the base layer 11. The sheet body 10B composed of the adhesive layer 12 and the base layer 11 may satisfy the following conditions: (Condition 3) The total light transmittance of the sheet body 10B is 30% or more.

[0017] If the total light transmittance of the sheet body 10B is 30% or more, when the sheet body 10B is attached to the nipple, it is possible to observe the nipple through the sheet body 10B. Therefore, after the sheet body 10B is attached to the nipple, it is possible to visually check the condition of the nipple without peeling off the sheet body 10B. Therefore, since it is not necessary to peel off the sheet body 10B to visually check the condition of the nipple, it is not necessary to peel off a portion of the sheet body 10B once attached to the nipple, and therefore the sheet body 10B is less likely to peel off from the nipple. Furthermore, if the total light transmittance of the sheet body 10B is 30% or more, it is also possible to check through the sheet body 10B whether milk secreted from the nipple orifice is present in the space formed by the sheet body 10B below the nipple orifice.

[0018] The total light transmittance of the sheet body 10B is a value measured by a method in accordance with JIS K 7361-1:1997 "Plastics - Test method for total light transmittance of transparent materials - Part 1: Single beam method."

[0019] In the example shown in Figure 1, the mastitis prevention sheet 10 further comprises a protective layer 13 and a release layer 14. Of the above-mentioned base material layer 11, the surface opposite to the surface that contacts the adhesive layer 12 is the surface 11S. The protective layer 13 contacts the surface 11S of the base material layer 11. The protective layer 13 covers the entire base material layer 11. The release layer 14 contacts the adhesive surface 12S of the adhesive layer 12. The release layer 14 covers the entire adhesive layer 12.

[0020] FIG. 2 shows the planar structure of the mastitis prevention sheet 10 as viewed from a perspective opposite to the plane on which the mastitis prevention sheet 10 spreads. As shown in FIG. 2, the mastitis prevention sheet 10 has a flat plate shape before use. When viewed from a perspective opposite to the plane on which the mastitis prevention sheet 10 spreads, the mastitis prevention sheet 10 has a belt-shaped portion 10S along the outer edge 10E of the mastitis prevention sheet 10, and through-holes 10H located in the belt-shaped portion 10S. In the example shown in FIG. 2, the mastitis prevention sheet 10 has multiple through-holes 10H. When the mastitis prevention sheet 10 has through-holes 10H, the number of through-holes 10H may be one or more, and multiple through-holes 10H are preferred. Each through-hole 10H penetrates the mastitis prevention sheet 10 in the thickness direction of the mastitis prevention sheet 10. Each through-hole 10H has a shape that extends along the outer edge 10E of the mastitis prevention sheet 10.

[0021] When the mastitis prevention sheet 10 is attached to the nipple, the through hole 10H can be positioned below the nipple opening, so that milk secreted from the nipple opening can be discharged from the space surrounded by the mastitis prevention sheet 10 through the through hole 10H.

[0022] In the example of the mastitis prevention sheet 10 shown in Figure 2, when viewed from a perspective opposite to the plane on which the mastitis prevention sheet 10 extends, the outer edge 10E of the mastitis prevention sheet 10 has the same shape as the outer edge of the protective layer 13. The outer edge 10E of the mastitis prevention sheet 10 has a rectangular shape extending along the first direction D1, which is the longitudinal direction of the mastitis prevention sheet 10. The base material layer 11, adhesive layer 12, and release layer 14 have rectangular shapes extending along the first direction D1, similar to the mastitis prevention sheet 10. The base material layer 11, adhesive layer 12, and release layer 14 have the same shape. Therefore, in the following, we will compare the sizes of the protective layer 13 and the base material layer 11, and will omit a comparison of the sizes of the adhesive layer 12 and release layer 14 with the size of the protective layer 13. In addition, in the following, we will explain the position of the base material layer 11 relative to the protective layer 13, and will omit a description of the positions of the adhesive layer 12 and release layer 14 relative to the protective layer 13.

[0023] The base material layer 11 is smaller than the protective layer 13, and when viewed from a perspective facing the plane in which the mastitis prevention sheet 10 spreads, the base material layer 11 is located within the protective layer 13. When viewed from a perspective facing the plane in which the mastitis prevention sheet 10 spreads, part of the outer edge of the base material layer 11 overlaps part of the outer edge of the protective layer 13. In the example shown in Figure 2, the outer edge of the protective layer 13 is composed of a first long side, a second long side, a first short side, and a second short side. The first long side and the second long side extend along a first direction D1, and the first short side and the second short side extend along a second direction D2, which is the short side direction of the mastitis prevention sheet 10. The second direction D2 is a direction perpendicular to the first direction D1. When viewed from a viewpoint opposite to the plane on which the mastitis prevention sheet 10 spreads, the outer edge of the base material layer 11 overlaps the first long side and part of each short side of the outer edge of the protective layer 13. In the base material layer 11, the length LLS of the long side along the first direction D1 may be, for example, 100 mm or more and 150 mm or less. In the base material layer 11, the length LSS of the short side along the second direction D2 may be, for example, 50 mm or more and 100 mm or less.

[0024] The protective layer 13 includes a first region 13R1 and a second region 13R2. The second region 13R2 is a region of the protective layer 13 that contacts the base material layer 11. In contrast, the first region 13R1 is a region of the protective layer 13 that does not contact the base material layer 11. The regions 13R1 and 13R2 extend along the first direction D1, and the first region 13R1 and the second region 13R2 are aligned along the second direction D2. The length of the first region 13R1 along the second direction D2 may be, for example, 5 mm or more and 20 mm or less.

[0025] The above-mentioned belt-shaped portion 10S is located in the second region 13R2 of the protective layer 13. That is, the belt-shaped portion 10S includes part of the protective layer 13, part of the base material layer 11, part of the adhesive layer 12, and part of the release layer 14 of the mastitis prevention sheet 10. Therefore, each through-hole 10H located in the belt-shaped portion 10S penetrates the protective layer 13, base material layer 11, adhesive layer 12, and release layer 14 in the thickness direction of the mastitis prevention sheet 10.

[0026] The belt-shaped portion 10S has a shape that follows the first long side of the outer edge of the protective layer 13 and extends in the first direction D1. In the example shown in FIG. 2, the belt-shaped portion 10S is located on the opposite side of the first region 13R1 of the protective layer 13 with respect to the center of the mastitis prevention sheet 10 in the second direction D2. In the belt-shaped portion 10S, the multiple through holes 10H are arranged at equal intervals along the first direction D1. The intervals between the through holes 10H may include intervals having a first length and intervals having a second length different from the first length. That is, although the multiple through holes 10H are arranged regularly in the example shown in FIG. 2, the multiple through holes 10H may be arranged irregularly.

[0027] 2, the plurality of through holes 10H are composed of through holes 10H included in a first row 10HL1 and through holes 10H included in a second row 10HL2. Each row 10HL1, 10HL2 extends along a first direction D1, and the first row 10HL1 and the second row 10HL2 are arranged at an interval in the second direction D2. The through holes 10H belonging to the first row 10HL1 and the through holes 10H belonging to the second row 10HL2 are arranged in a staggered arrangement in one array composed of the first row 10HL1 and the second row 10HL2.

[0028] The length L10H of the through holes 10H may be 1 mm or more and 4 mm or less when viewed from a perspective opposite to the plane on which the mastitis prevention sheet 10 extends. In the example shown in Figure 2, the length L10H of the through holes 10H in the first direction D1 may be 1 mm or more and 4 mm or less. When the length of the through holes 10H is 1 mm or more and 4 mm or less, it is possible to increase the reliability with which the mastitis prevention sheet 10 adheres to the nipples and to increase the reliability with which milk is discharged through the through holes 10H.

[0029] The mastitis prevention sheet 10 may have the structure shown in Figures 3 to 5, which are referred to below. Figures 3 to 5 show the planar structure of the mastitis prevention sheet 10 as seen from a viewpoint opposite to the plane on which each mastitis prevention sheet 10 spreads.

[0030] The mastitis prevention sheet 10 of a first modified example shown in Figure 3 has a different external shape from the mastitis prevention sheet 10 shown in Figure 2. As shown in Figure 3, the mastitis prevention sheet 10 may have a trapezoidal shape. The protective layer 13 has a trapezoidal shape, and in the protective layer 13, a pair of short sides extending along the second direction D2 are parallel to each other. The base layer 11, like the protective layer 13, has a trapezoidal shape, and in the base layer 11, a pair of short sides extending along the second direction D2 are parallel to each other. The adhesive layer 12 and the release layer 14 have the same shape as the base layer 11. In the protective layer 13, a first region 13R1 and a second region 13R2 are aligned along the second direction D2. In the protective layer 13, the second region 13R2 has a trapezoidal shape, and the first region 13R1 has a parallelogram shape along one long side of the second region 13R2.

[0031] The mastitis prevention sheet 10 of the second modified example shown in Figure 4 has a different external shape than the mastitis prevention sheet 10 shown in Figure 2, similar to the mastitis prevention sheet 10 shown in Figure 3.

[0032] As shown in Figure 4, the mastitis prevention sheet 10 may have a substantially trapezoidal shape. However, in the mastitis prevention sheet 10, each long side of the protective layer 13 has a bending point at the boundary between the first region 13R1 and the second region 13R2. In the protective layer 13, the first region 13R1 and the second region 13R2 are aligned along the first direction D1. The first region 13R1 and the second region 13R2 each have a trapezoidal shape. The first region 13R1 has a trapezoidal shape that tapers more steeply than the second region 13R2 in the first direction D1, in the direction from the second region 13R2 to the first region 13R1. The second region 13R2 has a trapezoidal shape that tapers in the first direction D1, in the direction from the second region 13R2 to the first region 13R1.

[0033] When viewed from a perspective opposite to the plane on which the mastitis prevention sheet 10 is spread, the base material layer 11 has a trapezoidal shape that overlaps the second region 13R2 of the protective layer 13. The adhesive layer 12 and the release layer 14 have the same shape as the base material layer 11.

[0034] The third modified example of the mastitis prevention sheet 10 shown in Figure 5 differs from the mastitis prevention sheet 10 shown in Figure 2 in that the protective layer 13 of the mastitis prevention sheet 10 has a slit 13B.

[0035] As shown in Fig. 5, the protective layer 13 has two cuts 13B in the first region 13R1. Each cut 13B extends from the outer edge of the protective layer 13 toward the base layer 11. The cuts 13B have a length that does not reach the base layer 11. In the example shown in Fig. 5, each cut 13B extends along the second direction D2. Because the protective layer 13 has the cuts 13B, when peeling the protective layer 13 from the base layer 11, it is possible to peel the protective layer 13 from the base layer 11 by splitting the protective layer 13 along the cuts 13B. Therefore, it is easy to peel the protective layer 13 from the base layer 11.

[0036] The distance D13B between the slits 13B in the first direction D1 may be, for example, 3 mm or more and 40 mm or less. This makes it easy to grasp the portions of the protective layer 13 located between the slits 13B. The center of the mastitis prevention sheet 10 in the first direction D1 may be located between the slits 13B. This makes it possible to split the protective layer 13 approximately in the center in the first direction D1 by splitting the protective layer 13 along the slits 13B.

[0037] The mastitis prevention sheet 10 may have only one slit 13B, or may have three or more. The mastitis prevention sheet 10 of the first modified example may also have a slit 13B. In this case, the mastitis prevention sheet 10 may have a slit 13B located in the first region 13R1 of the protective layer 13 and extending, for example, along the second direction D2. The mastitis prevention sheet of the second modified example may also have a slit 13B. In this case, the mastitis prevention sheet 10 may have a slit 13B located in the first region 13R1 of the protective layer 13 and extending, for example, along the first direction D1.

[0038] [Method of using the mastitis prevention sheet] A method of using the mastitis prevention sheet 10 will be described with reference to Figures 6 to 10. Below, a method of using the mastitis prevention sheet 10 when attaching the mastitis prevention sheet 10 to the teats of a dairy cow, which is an example of livestock, will be described. The method of using the mastitis prevention sheet 10 includes attaching the mastitis prevention sheet 10 to the teat so that the mastitis prevention sheet 10 has a tubular shape that surrounds the teat, and bringing a first part of the adhesive surface 12S into close contact with a second part of the adhesive surface at a position away from the teat opening of the teat so as to close the tubular end of the mastitis prevention sheet 10.

[0039] According to the method of using the mastitis prevention sheet 10 disclosed herein, the mastitis prevention sheet 10 is attached to the nipple so as to have a cylindrical shape that surrounds the nipple. This makes it difficult for milk secreted from the nipple opening to spread between the adhesive surface 12S and the nipple. Furthermore, because the first portion of the adhesive surface 12S adheres closely to the second portion at a position away from the nipple opening, milk secreted from the nipple opening is less likely to remain between the adhesive surface 12S and the nipple opening. This makes it difficult for the adhesive layer to peel off from the nipple, and as a result, the mastitis prevention sheet 10 is less likely to peel off from the nipple. The method of using the mastitis prevention sheet 10 will be explained in more detail below with reference to the drawings.

[0040] As shown in Figure 6, when using the mastitis prevention sheet 10, after peeling off the release layer 14 from the adhesive layer 12, part of the adhesive surface 12S is attached to the teat N of the dairy cow C. This positions the mastitis prevention sheet 10 relative to the teat N. At this time, the mastitis prevention sheet 10 is positioned relative to the teat N so that the through-holes 10H of the mastitis prevention sheet 10 are located away from the teat orifice NA located at the tip of the teat N. In other words, the mastitis prevention sheet 10 is positioned relative to the teat N so that the through-holes 10H of the mastitis prevention sheet 10 are located below the teat orifice NA.

[0041] Next, as shown in Figure 7, the mastitis prevention sheet 10 is folded so that the adhesive surface 12S of the mastitis prevention sheet 10 surrounds the nipple N, thereby adhering the third portion 12S3 of the adhesive surface 12S to the fourth portion 12S4 of the adhesive surface 12S. This causes the flat mastitis prevention sheet 10 to be attached to the nipple N in a cylindrical shape that surrounds the nipple N. The adhesive area formed by adhering the third portion 12S3 of the adhesive surface 12S to the fourth portion 12S4 is likely to be located outside the nipple N in the radial direction of the nipple N, and is unlikely to be located below the nipple orifice NA. As a result, the adhesive area is less likely to come into contact with milk secreted from the nipple orifice NA.

[0042] Next, as shown in Figure 8, the protective layer 13 is peeled off from the base layer 11. At this time, for example, the user of the mastitis prevention sheet 10 grasps the first region 13R1 of the protective layer 13. Next, the user peels the protective layer 13 away from the base layer 11 in the direction from the first region 13R1 to the second region 13R2, thereby peeling the protective layer 13 off from the base layer 11. After peeling the protective layer 13 from the base layer 11, the user preferably grasps the tubular portion of the mastitis prevention sheet 10 that surrounds the nipple N, thereby bringing the tubular portion into close contact with the nipple N.

[0043] 9, the first portion 12S1 of the adhesive surface 12S is brought into close contact with the second portion 12S2 of the adhesive surface 12S at a position away from the nipple orifice NA of the nipple N so as to close the tubular end 10TE of the sheet body 10B of the mastitis prevention sheet 10. In this way, according to the method of using the mastitis prevention sheet 10 disclosed herein, the mastitis prevention sheet 10 is attached to the nipple N so as to have a tubular shape that surrounds the nipple N. As a result, the adhesive portion formed by the second portion 12S2 being in close contact with the first portion 12S1 of the adhesive surface 12S makes it difficult for milk secreted from the nipple orifice NA to spread, making it difficult for the adhesive layer 12 to peel off from the nipple N. This makes it difficult for the sheet body 10B of the mastitis prevention sheet 10 to peel off from the nipple N.

[0044] Furthermore, since the adhesion strength on the adhesive surface 12S is approximately constant within the adhesive surface 12S, the adhesion strength between the first portion 12S1 and the second portion 12S2 is equal to the adhesion strength between the third portion 12S3 and the fourth portion 12S4.

[0045] In this case, the mastitis prevention sheet 10 may be attached to the nipple N so that the through-hole 10H is located at the tubular end 10TE of the sheet body 10B. In this case, since the through-hole 10H is located at the tubular end 10TE of the sheet body 10B, it is possible for the milk secreted from the nipple N to be discharged from the space surrounded by the sheet body 10B through the through-hole 10H in the tubular end 10TE.

[0046] When sealing the tubular end 10TE of the sheet body 10B, the adhesive portion formed by adhering the third portion 12S3 of the adhesive surface 12S to the fourth portion 12S4 may be wrapped around the nipple N. This prevents the adhesive portion from protruding in the radial direction of the nipple N, thereby preventing the adhesive portion from getting caught on an obstacle, for example. This prevents the sheet body 10B from coming off the nipple N.

[0047] As shown in Figure 10, the method of using the mastitis prevention sheet 10 may further include discharging milk M through the through-holes 10H located at the tube end 10TE of the sheet body 10B. When discharging milk M through the through-holes 10H, the user of the mastitis prevention sheet 10 may grasp the sheet body 10B together with the teat N of the dairy cow C, thereby discharging milk M from the space enclosed by the sheet body 10B to the outside. Alternatively, milk M secreted from the teat orifice NA into the space enclosed by the sheet body 10B may seep out through the through-holes 10H due to its own weight. In this case, the sheet body 10B is even less likely to peel off from the teat N than if milk M secreted from the teat orifice NA remained in the space enclosed by the sheet body 10B.

[0048] [Manufacturing method of mastitis prevention sheet] A manufacturing method of the mastitis prevention sheet 10 will be described with reference to Figures 11 to 13. When manufacturing the mastitis prevention sheet 10, the base material layer 11 and adhesive layer 12 provided in the mastitis prevention sheet 10 are formed separately, and then the adhesive layer 12 is bonded to the base material layer 11. Below, the process of manufacturing the base material layer 11 will be described with reference to Figure 11, the process of manufacturing the adhesive layer 12 will be described with reference to Figure 12, and the process of manufacturing the mastitis prevention sheet 10 by bonding the adhesive layer 12 to the base material layer 11 will be described with reference to Figure 13.

[0049] As shown in FIG. 11 , the process for preparing the substrate layer 11 includes a first coating film forming step (step S11), a drying step (step S12), and an aging step (step S13). Specifically, a first coating film is formed using a first coating liquid for forming the substrate layer 11 (step S11). At this time, the first coating film is formed on one surface of the protective layer 13. The first coating film is then dried (step S12). The thickness of the first coating film after drying may be, for example, 5 μm or more and 30 μm or less. The first coating film is then aged to obtain the substrate layer 11 from the first coating film, resulting in a first laminate composed of the substrate layer 11 and the protective layer 13 (step S13). The thickness of the substrate layer 11 obtained after aging is equal to the thickness of the first coating film after drying.

[0050] The protective layer 13 is formed from a synthetic resin. The protective layer 13 may be formed, for example, from a base sheet and a release layer. In this case, the release layer is laminated on the base sheet. When the protective layer 13 includes a base sheet and a release layer, the release layer is in contact with the base layer 11. The base sheet may be formed, for example, from either a polyolefin resin or a polyester resin. The polyester resin may be, for example, a polyethylene terephthalate resin. The polyolefin resin may be, for example, a polypropylene resin. The base sheet is preferably formed from a polyolefin resin. The base sheet may be any of a uniaxially oriented sheet, a biaxially oriented sheet, and a non-oriented sheet. The release layer may be formed, for example, from a silicone resin.

[0051] The protective layer 13 may be composed of only the above-mentioned base sheet. In this case, the contact surface of the base sheet that comes into contact with the base layer 11 may be processed to facilitate peeling of the base layer 11 from the base sheet. The processing of the contact surface of the base sheet may be, for example, embossing. The thickness of the protective layer 13 may be, for example, 30 μm or more and 400 μm or less.

[0052] The base layer 11 is made of a synthetic resin. The synthetic resin used to form the base layer 11 may be, for example, a polyurethane resin. The polyurethane resin may be an aqueous polyurethane. This allows for a base layer 11 that is highly suitable for application to the skin. The thickness of the base layer 11 may be, for example, 5 μm or more and 30 μm or less. The thin base layer 11 made of polyurethane resin stretches well even when a small external force is applied to the base layer 11 to stretch it. Therefore, the base layer 11 has high conformability to the nipple, which is the target of application of the sheet body 10B, and can have high adhesion to the nipple.

[0053] The thickness of the substrate layer 11 may be, for example, 5 μm or more and 30 μm or less. The tensile elongation at break of the substrate layer 11 may be, for example, 130% or more. The tensile elongation at break can be determined in accordance with JIS K 7161-1:2014 (ISO 527-1) "Plastics - Determination of tensile properties - Part 1: General rules" and JIS K 7127:1999 (ISO 527-3) "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets." If the object to be measured does not have a yield point, the tensile break strain is measured; if it has a yield point, the nominal tensile strain at break is measured, and the tensile break elongation can be determined using these measured values.

[0054] The tensile strength at 100% elongation of the base material layer 11 may be, for example, 4 N / cm or less. The tensile strength at 100% elongation is the value obtained by dividing the magnitude of the force measured when the strain reaches a specified value (100%), as defined in JIS K 7161-1:2014 (ISO 527-1) "Plastics - Determination of tensile properties - Part 1: General rules," by the width of the test piece. The tensile strength at 100% elongation (T) (N / cm) can be calculated using the following formula:

[0055] T = F / W In the above formula, F is the magnitude of the measured force (N), and W is the width of the test piece (cm).

[0056] The base layer 11 may be formed from a synthetic resin other than polyurethane resin, such as polyvinylidene fluoride resin, ethylene-vinyl acetate copolymer resin, polypropylene resin, and polyethylene terephthalate resin.

[0057] As shown in FIG. 12 , the process for preparing the adhesive layer 12 includes an acidic aqueous solution preparation step (step S21), a second coating liquid preparation step (step S22), a second coating film formation step (step S23), and a drying step (step S24). Specifically, when forming the adhesive layer 12, first, an acidic aqueous solution containing chitosan is prepared (step S21). Next, a second coating liquid for forming the adhesive layer 12 is prepared using an acidic aqueous solution containing chitosan, a main adhesive agent for forming the adhesive layer 12, an adhesive curing agent, and chitosan (step S22). Because the acidic aqueous solution containing chitosan is prepared before mixing the main adhesive agent with the second coating liquid, chitosan molecules can be uniformly distributed in the second coating liquid. This ensures that chitosan molecules are uniformly distributed in the adhesive layer formed using the second coating liquid. The second coating liquid may contain a solvent different from the acidic aqueous solution. In this case, the viscosity of the second coating liquid can be adjusted using a solvent other than the acidic aqueous solution.

[0058] In this way, the adhesive layer 12 is formed by mixing an acidic aqueous solution containing chitosan with the base and curing agent contained in the adhesive. Chitosan is soluble in an acidic aqueous solution, and in the acidic aqueous solution, the amino groups of chitosan have a positive charge, which allows the chitosan to have antibacterial activity. As described above, the adhesive layer 12 is formed using chitosan dissolved in an acidic aqueous solution and having antibacterial activity, so the adhesive layer 12 can contain antibacterial chitosan. The acidic aqueous solution in which the chitosan powder is dissolved may contain an inorganic acid or an organic acid. Examples of inorganic acids include hydrochloric acid, nitric acid, and sulfuric acid. Examples of organic acids include formic acid, acetic acid, lactic acid, and citric acid.

[0059] Next, a second coating film is formed on one surface of the release layer 14 using the second coating liquid (step S23). The second coating film is then dried to obtain the adhesive layer 12 from the second coating film (step S24). This results in an adhesive layer 12 that satisfies the above-described conditions 1 and 2. Because the second coating liquid used to form the adhesive layer 12 contains an acidic compound, the adhesive layer 12 formed using the second coating liquid also contains an acidic compound. The thickness of the adhesive layer 12 may be, for example, 5 μm or more and 30 μm or less. This method of forming the adhesive layer 12 can increase the certainty that chitosan has an antibacterial effect in an adhesive layer 12 containing 2% by mass or more of chitosan.

[0060] The release layer 14 may be configured so that the peel strength between the release layer 14 and the adhesive layer 12 is smaller than the peel strength between the protective layer 13 and the base layer 11. The release layer 14 is made of a synthetic resin. The release layer 14 is made of, for example, a base sheet and a release layer. The release layer is laminated on the base sheet. When the release layer 14 comprises a base sheet and a release layer, the release layer is in contact with the adhesive layer 12. The base sheet may be made of, for example, a polyethylene terephthalate resin. The base sheet may be any of a uniaxially oriented sheet, a biaxially oriented sheet, and a non-oriented sheet. The release layer may be made of, for example, a silicone resin.

[0061] The release layer 14 may be composed of only the above-mentioned base sheet. In this case, the contact surface of the base sheet that comes into contact with the adhesive surface 12S of the adhesive layer 12 may be processed to facilitate peeling of the adhesive layer 12 from the base sheet. The processing of the contact surface of the base sheet may be, for example, embossing. The thickness of the release layer 14 may be, for example, 12 μm or more and 350 μm or less.

[0062] The adhesive layer 12 may be formed from various types of adhesives. The adhesive for forming the adhesive layer 12 may be, for example, a rubber-based adhesive, an acrylic-based adhesive, a silicone-based adhesive, or a urethane-based adhesive. The adhesive layer 12 may be formed from a two-component adhesive. The thickness of the adhesive layer 12 may be, for example, 5 μm or more and 30 μm or less. To change the adhesion strength between the first portion 12S1 and the second portion 12S2 of the adhesive surface 12S in the adhesive layer 12 from a first value to a second value, for example, the adhesive forming the adhesive layer 12 may be changed from a first material to a second material. Furthermore, the adhesion strength of the adhesive layer 12 tends to increase as the thickness of the adhesive layer 12 increases. Furthermore, the adhesion strength of the adhesive layer 12 tends to decrease if the adhesive layer 12 is dried and then aged in an environment at a higher temperature than when the adhesive layer 12 was dried. When aging the adhesive layer 12, for example, the adhesive layer 12 may be left standing in an environment at 80°C for 7 days or more.

[0063] The chitosan may be in the form of a powder. The maximum particle size of the chitosan may be, for example, 50 μm or less. From the viewpoint of preventing chitosan from being recovered on the plate used for applying the second coating film, it is preferable that the maximum particle size of the chitosan be smaller than the thickness of the second coating film before drying. From the viewpoint of making it easier for the chitosan contained in the adhesive layer 12 to come into contact with the papilla N, it is preferable that the maximum particle size of the chitosan be larger than the thickness of the adhesive layer 12 formed by drying the second coating film. The maximum particle size of the chitosan can be determined, for example, by the size of the openings in the sieve used to sort the chitosan.

[0064] As shown in Figure 13, the process of obtaining a mastitis prevention sheet 10 from a first laminate and a second laminate includes a bonding step (step S31) and an aging step (step S32). In detail, when obtaining the mastitis prevention sheet 10, first, the adhesive layer 12 of the second laminate is bonded to the base layer 11 of the first laminate (step S31). Next, the laminate composed of the first laminate and the second laminate is aged (step S32). This allows the mastitis prevention sheet 10 to be obtained. In the obtained mastitis prevention sheet 10, the protective layer 13, base layer 11, adhesive layer 12, and release layer 14 are laminated in the order described above.

[0065] [Test Example] A test example will be described with reference to Figures 14 and 15. [Test Example 1] [Test Example 1-1] A biaxially oriented polypropylene (OPP) film (FOR-MP, manufactured by Futamura Chemical Co., Ltd.) with one matte surface of a pair of surfaces facing each other in the thickness direction was prepared as a protective layer. An aqueous polyurethane containing an ether-based polyol (Takelac WS-6021, manufactured by Mitsui Chemicals, Inc.) (Takelac is a registered trademark), which serves as a first coating liquid, was applied to the matte surface of the OPP film, thereby forming a first coating film. The first coating film was then dried to obtain a dried first coating film having a thickness of 15 µm. The dried first coating film was then aged at room temperature for 48 hours to obtain a substrate layer. This resulted in a first laminate composed of a protective layer and a substrate layer.

[0066] A release film (Cerapeel WZ, Toray Film Processing Co., Ltd.) (Cerapeel is a registered trademark) consisting of a polyethylene terephthalate (PET) film and a release layer was prepared as the release layer. A urethane adhesive (SP-205, Toyochem Co., Ltd.), a curing agent (T-501B, Toyochem Co., Ltd.), and a diluent (NC401 Solvent C, Toyo Ink Co., Ltd.) were also prepared. Chitosan powder (Hokkaido Soda Co., Ltd., chitosan powder, deacetylation degree 83.5%, molecular weight approximately 220,000) selected through a 0.6 mm sieve was dispersed in water to a chitosan powder mass of 5% by mass, thereby obtaining a chitosan aqueous solution. Next, to dissolve the chitosan powder, an acetic acid aqueous solution containing chitosan was prepared by adding an equal mass of acetic acid to the chitosan powder.

[0067] When the sum of the mass of the solids in the base agent, the mass of chitosan, and the mass of the solids in the curing agent is 100% by mass, an acetic acid solution containing chitosan was added to the base agent so that the mass of chitosan was 2% by mass, and then the base agent and the acetic acid solution containing chitosan were mixed. Next, a dilution solvent was added to the first mixture of the base agent and the acetic acid solution containing chitosan to adjust the viscosity of the second mixture composed of the base agent, the acetic acid solution containing chitosan, and the solvent. Next, a curing agent was added to the second mixture, and the second mixture with the added curing agent was then stirred to obtain a second coating liquid for forming an adhesive layer.

[0068] Next, the second coating liquid was applied to the release layer of the release film to obtain a second coating film. At this time, the coating amount of the second coating liquid was 100 g / m ２ The second coating film was then dried to obtain a 15 μm thick adhesive layer, thereby obtaining a second laminate composed of a release layer and an adhesive layer.

[0069] The adhesive layer of the second laminate was bonded to the base layer of the first laminate to obtain a laminate. The laminate had a layer structure in which a protective layer, a base layer, an adhesive layer, and a release layer were laminated in the order described. The laminate was then aged at 50°C for 72 hours to obtain the mastitis prevention sheet of Test Example 1-1.

[0070] [Test Example 1-2] A mastitis prevention sheet of Test Example 1-2 was obtained in the same manner as Test Example 1-1, except that an aqueous acetic acid solution containing chitosan was added to the main ingredient so that the mass of chitosan was 5% by mass.

[0071] [Test Example 1-3] A mastitis prevention sheet of Test Example 1-3 was obtained in the same manner as Test Example 1-1, except that an aqueous acetic acid solution containing chitosan was added to the main ingredient so that the mass of chitosan was 10 mass%.

[0072] [Test Example 1-4] An external nipple seal (Tee Toner, manufactured by Tokuyama Corporation) (Tee Toner is a registered trademark) was used as the mastitis prevention sheet for Test Example 1-4. The external nipple seal had a transparent film, a urethane layer, an adhesive layer formed from butyl acrylate, and release paper laminated in the order listed.

[0073] [Test Example 1-5] A mastitis prevention sheet of Test Example 1-5 was obtained in the same manner as Test Example 1-1, except that an aqueous acetic acid solution containing chitosan was added to the main ingredient so that the mass of chitosan was 0.1 mass%.

[0074] [Test Example 1-6] A mastitis prevention sheet of Test Example 1-6 was obtained in the same manner as Test Example 1-1, except that an aqueous acetic acid solution containing chitosan was added to the main ingredient so that the mass of chitosan was 1% by mass.

[0075] [Test Example 1-7] A mastitis prevention sheet for Test Example 1-7 was obtained using the same method as Test Example 1-1, except for the following change in the adhesive layer formation method. In Test Example 1-7, a release film (same as above) was prepared as a peel layer when forming the adhesive layer. A urethane adhesive (same as above), a curing agent (same as above), and fibrous chitosan (manufactured by Hokkaido Soda Co., Ltd.) were also prepared. Next, chitosan was added to the base agent so that the chitosan mass was 30% by mass when the sum of the mass of the solids in the base agent, the mass of chitosan, and the mass of the curing agent was 100% by mass. The base agent and chitosan were then mixed to obtain a first mixture. A curing agent was added to the first mixture, and the first mixture with the curing agent added was then stirred to obtain a second coating liquid for forming the adhesive layer.

[0076] Next, the second coating liquid was applied to the release layer of the release film to obtain a second coating film. At this time, the coating amount of the second coating liquid was 100 g / m ２ The second coating film was then dried to obtain a 15 μm thick adhesive layer, thereby obtaining a second laminate composed of a release layer and an adhesive layer.

[0077] [Test Example 1-8] A mastitis prevention sheet of Test Example 1-8 was obtained by the same method as Test Example 1-1, except that the method of forming the adhesive layer in Test Example 1-1 was changed as follows. In Test Example 1-8, a release film (same as above) was prepared as a peeling layer when forming the adhesive layer. In addition, a urethane adhesive (same as above) and a curing agent (same as above) were prepared as the main agent. Next, the curing agent was added to the main agent, and the main agent with the curing agent added was stirred to obtain a second coating liquid for forming the adhesive layer.

[0078] Next, the second coating liquid was applied to the release layer of the release film to obtain a second coating film. At this time, the coating amount of the second coating liquid was 100 g / m ２ The second coating film was then dried to obtain a 15 μm thick adhesive layer, thereby obtaining a second laminate composed of a release layer and an adhesive layer.

[0079] [Test Example 1-9] A mastitis prevention sheet for Test Example 1-9 was obtained using the same method as Test Example 1-1, except for the following change in the adhesive layer formation method. In Test Example 1-9, a release film (same as above) was prepared as a peel layer when forming the adhesive layer. A urethane adhesive (same as above), a curing agent (same as above), and chitosan powder (same as above) were also prepared. Next, chitosan was added to the base agent so that the chitosan mass was 10% by mass when the sum of the mass of the solids in the base agent, the mass of chitosan, and the mass of the solids in the curing agent was 100% by mass. The base agent and chitosan were then mixed to obtain a first mixture. A curing agent was added to the first mixture, and the first mixture with the added curing agent was then stirred to obtain a second coating liquid for forming the adhesive layer.

[0080] Next, the second coating liquid was applied to the release layer of the release film to obtain a second coating film. At this time, the coating amount of the second coating liquid was 100 g / m ２ The second coating liquid was then dried to obtain a 15 μm thick adhesive layer, thereby obtaining a second laminate composed of the release layer and the adhesive layer.

[0081] [Evaluation Method] [Adhesion Strength] When measuring the adhesion strength between the first and second portions of the adhesive surface, two second laminates composed of a release layer and an adhesive layer were prepared for each mastitis prevention sheet. Next, a test specimen was prepared by attaching the adhesive layer of the second second laminate to the adhesive layer of the first second laminate. The adhesion strength between the two adhesive layers of the test specimen was measured using a tensile test in accordance with JIS K 7127:1999 "Plastics - Test Methods for Tensile Properties - Part 3: Test Conditions for Films and Sheets." An autograph tester (Shimadzu Corporation, Autograph AGS-X Load Cell 1 kN) (Autograph is a registered trademark) was used as the tensile tester, and the test speed was set to 300 mm / min. Three test specimens were prepared for each mastitis prevention sheet, and the average adhesion strength of the three test specimens was set as the adhesion strength for each test specimen.

[0082] [Peel Strength] For each mastitis preventive sheet of each test example, the peel strength between the base layer and the protective layer was measured. The peel strength between the base layer and the protective layer was measured using the same method as used to measure the adhesion strength on the adhesive surface. That is, the peel strength between the base layer and the protective layer of the mastitis preventive sheet was measured by a tensile test in accordance with JIS K 7127:1999 "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets." An autograph tester (same as above) was used as the tensile tester, and the test speed was set to 300 mm / min. For each mastitis preventive sheet of each test example, three sheets were prepared, and the average peel strength of the three sheets was set as the peel strength for each test example.

[0083] [Adhesive Strength] The adhesive strength of the adhesive layer of each mastitis prevention sheet was measured. The adhesive strength of the adhesive layer to the SUS plate was measured using the same method as when measuring the adhesive strength of the adhesive surface. That is, the adhesive strength of the adhesive layer in the mastitis prevention sheet was measured by a tensile test in accordance with JIS K 7127:1999 "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets." An autograph tester (same as above) was used as the tensile tester, and the test speed was set to 300 mm / min. For each mastitis prevention sheet in each test example, three sheets were prepared, and the average adhesive strength of the three sheets was set as the adhesive strength for each test example.

[0084] [Total Light Transmittance] A laminate of the base material layer and adhesive layer provided in the mastitis preventive sheet of each test example was formed on a paper frame to form a test specimen for the mastitis preventive sheet of each test example. The total light transmittance of the test specimen was measured using a method in accordance with JIS K 7361-1:1997 "Plastics - Test method for total light transmittance of transparent materials - Part 1: Single beam method." A haze meter (Murakami Color Research Laboratory, Haze meter HM-150) was used for this measurement. Three test specimens were prepared for each mastitis preventive sheet of each test example, and the average value of the total light transmittances for the three test specimens was set as the total light transmittance for each test example.

[0085] [Applicability] The mastitis prevention sheet of each test example was attached to the silicone nipple of a milk bottle for dairy cows. At this time, the mastitis prevention sheet of each test example was attached to the silicone nipple using the method of use previously described with reference to Figures 6 to 9. The applicability of the mastitis prevention sheet of each test example when attached to the silicone nipple was evaluated using the following two-point scale.

[0086] ○ The mastitis prevention sheet could be attached to the silicone nipple with a space below the nipple opening in which water supplied from the baby bottle could remain. × The mastitis prevention sheet could not be attached to the silicone nipple with a space below the nipple opening in which water supplied from the baby bottle could remain.

[0087] [Antibacterial effect] The antibacterial activity value against Escherichia coli of each mastitis prevention sheet was measured according to JIS Z 2801:2010 "Antibacterial processed products - Antibacterial test method, antibacterial effect." The antibacterial effect of each mastitis prevention sheet was evaluated according to the following two-point scale.

[0088] Good: The antibacterial activity value is 2.0 or more, and the mastitis prevention sheet has an antibacterial effect. Bad: The antibacterial activity value is less than 2.0, and the mastitis prevention sheet does not have an antibacterial effect.

[0089] [Evaluation Results] The evaluation results for adhesion strength, peel strength, adhesive strength, total light transmittance, application, and antibacterial effect for each mastitis prevention sheet are shown in Figure 14. As shown in Figure 14, the adhesion strength of the adhesive layer was 3.7 N / 25 mm in Test Example 1-1, 3.1 N / 25 mm in Test Example 1-2, and 2.9 N / 25 mm in Test Example 1-3. The adhesion strength of the adhesive layer was 11.6 N / 25 mm in Test Example 1-4, 3.4 N / 25 mm in Test Example 1-5, and 2.6 N / 25 mm in Test Example 1-6. The adhesion strength of the adhesive layer was 1.3 N / 25 mm in Test Example 1-7, 2.2 N / 25 mm in Test Example 1-8, and 3.1 N / 25 mm in Test Example 1-9.

[0090] The peel strength between the base layer and the protective layer was found to be 0.08 N / 25 mm in Test Example 1-1, 0.09 N / 25 mm in Test Example 1-2, and 0.09 N / 25 mm in Test Example 3. The peel strength between the base layer and the protective layer was found to be 0.10 N / 25 mm in Test Example 1-4, 0.08 N / 25 mm in Test Example 1-5, and 0.08 N / 25 mm in Test Example 1-6. The peel strength between the base layer and the protective layer was found to be 0.12 N / 25 mm in Test Example 1-7, 0.08 N / 25 mm in Test Example 1-8, and 0.08 N / 25 mm in Test Example 1-9.

[0091] The adhesive strength of the adhesive layer was found to be 5.5 N / 25 mm in Test Example 1-1, 4.4 N / 25 mm in Test Example 1-2, and 6.0 N / 25 mm in Test Example 1-3. The adhesive strength of the adhesive layer was found to be 7.2 N / 25 mm in Test Example 1-4, 5.5 N / 25 mm in Test Example 1-5, and 6.4 N / 25 mm in Test Example 1-6. The adhesive strength of the adhesive layer was found to be 1.9 N / 25 mm in Test Example 1-7, 3.8 N / 25 mm in Test Example 1-8, and 3.4 N / 25 mm in Test Example 1-9.

[0092] The total light transmittance of the sheet body was found to be 92.0% in Test Example 1-1, 92.1% in Test Example 1-2, and 92.0% in Test Example 3. The total light transmittance of the sheet body was found to be 28.5% in Test Example 1-4, 92.1% in Test Example 1-5, and 92.1% in Test Example 1-6. The total light transmittance of the sheet body was found to be 79.8% in Test Example 1-7, 92.0% in Test Example 1-8, and 91.5% in Test Example 1-9.

[0093] The adhesiveness of the mastitis prevention sheet was found to be "○" in Test Examples 1-1 to 1-3, 1-5, 1-6, 1-8, and 1-9, and "×" in Test Examples 1-4 and 1-7.

[0094] The antibacterial effect of the mastitis prevention sheet was determined to be "○" in Test Examples 1-1 to 1-3, and "×" in Test Examples 1-5 to 1-9. In detail, the antibacterial activity value of Test Example 1-1 was 4.4, the antibacterial activity value of Test Example 1-2 was 6.2, and the antibacterial activity value of Test Example 1-3 was 6.1. The antibacterial activity value of Test Example 1-4 was unmeasurable, the antibacterial activity value of Test Example 1-5 was 1.0, and the antibacterial activity value of Test Example 1-6 was 0.8. The antibacterial activity value of Test Example 1-7 was 0.0, and the antibacterial activity value of Test Example 1-9 was -0.2. In calculating the antibacterial activity value, the test result of Test Example 1-8, which did not contain chitosan, was set as the control.

[0095] Thus, it was found that the mastitis prevention sheets of Test Examples 1-1 to 1-3 were rated "○" for both adhesion and antibacterial effect, while the mastitis prevention sheets of Test Examples 1-4 to 1-6 were rated "×" for at least one of adhesion and antibacterial effect.

[0096] That is, it was confirmed that when the adhesion strength was within the range of 2.6 N / 25 mm or more and 3.7 N / 25 mm or less, it had suitable adhesion. Furthermore, it was confirmed that when the peel strength was within the range of 0.08 N / 25 mm or more and 0.10 N / 25 mm or less, it was possible to peel the protective layer from the base layer. Furthermore, it was confirmed that when the adhesive strength was within the range of 3.4 N / 25 mm or more and 7.2 N / 25 mm or less, it was possible to attach the mastitis prevention sheet to the nipple in a cylindrical shape that surrounded the nipple.

[0097] Furthermore, it was found that with the mastitis prevention sheets of Test Examples 1-1 to 1-3 and Test Examples 1-5 to 1-9, the condition of the nipples could be visually observed through the sheet body attached to the nipples. In contrast, with the mastitis prevention sheet of Test Example 1-4, it was found that the condition of the nipples could not be visually observed through the sheet body attached to the nipples.

[0098] [Test Example 2] [Test Example 2-1] A mastitis prevention sheet for Test Example 2-1 was obtained using the same method as in Test Example 1-1. In this case, the length of the long side of the sheet body included in the mastitis prevention sheet was set to 120 mm, and the length of the short side was set to 70 mm. Then, of the pair of long sides of the sheet body, a band-shaped portion was set along the second long side opposite the first long side, which is the boundary between the first region of the protective layer and the sheet body. In this case, the width of the band-shaped portion in the direction in which the short side extends was set to 10 mm, based on the second long side. Then, two rows of through holes were formed in the band-shaped portion. In this case, the distance between the rows was set to 2 mm, the length of the through holes in the direction in which the long sides extend was set to 1 mm, and the distance between the through holes in the direction in which the long sides extend was set to 1 mm.

[0099] [Test Example 2-2] A mastitis prevention sheet of Test Example 2-2 was obtained in the same manner as Test Example 2-1, except that the length of the through holes in the direction in which the long sides extended was set to 2 mm.

[0100] [Test Example 2-3] A mastitis prevention sheet of Test Example 2-3 was obtained in the same manner as Test Example 2-1, except that the length of the through holes in the direction in which the long sides extended was set to 3 mm.

[0101] [Test Example 2-4] A mastitis prevention sheet of Test Example 2-4 was obtained in the same manner as Test Example 2-1, except that the length of the through holes in the direction in which the long sides extended was set to 4 mm.

[0102] [Test Example 2-5] A mastitis prevention sheet of Test Example 2-5 was obtained in the same manner as Test Example 2-1, except that the length of the through holes in the direction in which the long sides extended was set to 5 mm.

[0103] [Evaluation Method] [Attachment] When each mastitis prevention sheet was attached to the silicone teat of a milk bottle for dairy cows, whether or not the mastitis prevention sheet broke was evaluated using the following three-point scale.

[0104] ○: No tears occurred in the mastitis prevention sheet between the through-holes in the direction of the long side. △: Tears were observed in the mastitis prevention sheet in some areas between the through-holes in the direction of the long side, but no widening of the through-holes was observed. ×: When the mastitis prevention sheet was attached to the silicone nipple, the through-holes widened in the direction of the short side, causing parts of the mastitis prevention sheet to tear.

[0105] [Leakage] After pouring water into a milk bottle for dairy cows, each mastitis prevention sheet was attached to a silicone teat that was draining water from the teat opening over time. Then, 10 minutes after the mastitis prevention sheet was attached, whether or not water was leaking from the mastitis prevention sheet was evaluated using the following two-point scale.

[0106] ○ No water leaked from the holes in the mastitis prevention sheet. △ Water leaked from the holes in the mastitis prevention sheet.

[0107] [Excretion] After pouring water into a milk bottle for dairy cows, each mastitis prevention sheet was attached to a silicone nipple that was excreting water from the nipple opening over time. Next, 10 minutes after the mastitis prevention sheet was attached, the silicone nipple was squeezed with the right hand. Whether or not water could be excreted from the through-holes of the mastitis prevention sheet was evaluated using the following two-point scale.

[0108] ○ Water was discharged from the through-holes without resistance. △ Although it was possible for water to be discharged from the through-holes, the resistance to water discharge from the through-holes was high and the water was difficult to discharge, or although it was possible for water to be discharged from the through-holes, parts of the mastitis prevention sheet were torn as the water was discharged.

[0109] [Evaluation Results] The evaluation results of the mastitis prevention sheets of each test example regarding application, leakage, and discharge are shown in FIG.

[0110] As shown in Figure 15, the evaluation results for application of the mastitis prevention sheets were "○" for the mastitis prevention sheets of Test Example 2-1 to Test Example 2-3, "△" for the mastitis prevention sheet of Test Example 2-4, and "×" for the mastitis prevention sheet of Test Example 2-5. Note that, since the evaluation result for application of the mastitis prevention sheet of Test Example 2-5 was "×", leakage and discharge were not evaluated for the mastitis prevention sheet of Test Example 2-5.

[0111] The evaluation results for water leakage were found to be "○" for the mastitis prevention sheets of Test Examples 2-1 to 2-4.

[0112] The evaluation results for water discharge were "○" for the mastitis prevention sheets of Test Example 2-2 and Test Example 2-3. In contrast, the mastitis prevention sheet of Test Example 2-1 had high resistance when water was discharged from the through-holes, making it difficult for water to be discharged, and therefore the evaluation result was "△". Furthermore, the mastitis prevention sheet of Test Example 2-4 suffered tears in part of the mastitis prevention sheet as water was discharged, and therefore the evaluation result was "△".

[0113] From these results, it was confirmed that application, leakage, and discharge were all within the acceptable range in Test Examples 2-1 to 2-4, and the evaluation results for Test Examples 2-1 to 2-4 were "○". On the other hand, since the evaluation result for application in Test Example 2-5 was "×", it was also confirmed that the evaluation result for Test Example 2-5 itself was "×". Therefore, it can be said that the length of the through hole is preferably 1 mm or more and 4 mm or less, and more preferably 2 mm or more and 3 mm or less.

[0114] As described above, one embodiment of the method of using a mastitis prevention sheet, the mastitis prevention sheet, and the method of manufacturing a mastitis prevention sheet can achieve the following effects: (1) The mastitis prevention sheet 10 is attached to the nipple N so as to have a cylindrical shape that surrounds the nipple N. This makes it difficult for milk M secreted from the nipple orifice NA to spread between the adhesive surface 12S and the nipple N. Furthermore, because the first portion 12S1 of the adhesive surface 12S is in close contact with the second portion 12S2 at a position away from the nipple orifice NA, milk M secreted from the nipple orifice NA is unlikely to remain between the adhesive surface 12S and the nipple orifice NA. This makes it difficult for the adhesive layer 12 to peel off from the nipple N, and as a result, the sheet body 10B is unlikely to peel off from the nipple N.

[0115] (2) The adhesive portion formed by adhering the fourth portion 12S4 to the third portion 12S3 of the adhesive surface 12S is less likely to be penetrated by milk M secreted from the nipple opening NA, making it difficult for the adhesive layer 12 to peel off from the nipple N.

[0116] (3) By positioning the through hole 10H at the tubular end 10TE of the mastitis prevention sheet 10, it is possible to discharge the milk M secreted from the nipple N through the through hole 10H at the tubular end 10TE and out of the space surrounded by the sheet body 10B.

[0117] (4) When milk M is discharged through the through-hole 10H, the sheet body 10B is less likely to peel off from the nipple N than when the milk M secreted from the nipple opening NA remains within the space surrounded by the sheet body 10B.

[0118] (5) Because the adhesive layer 12 contains 2% by mass or more of chitosan, the mastitis prevention sheet 10 has an antibacterial effect. Furthermore, because the adhesion strength when the third portion 12S3 of the adhesive surface 12S is adhered to the fourth portion 12S4 is 2 N / 25 mm or more, the mastitis prevention sheet 10 can be attached to the nipple N by the adhesion portion formed by the adhesion between the third portion 12S3 and the fourth portion 12S4. Furthermore, because the adhesion strength between the first portion 12S1 and the second portion 12S2 of the adhesive surface 12S is 10 N / 25 mm or less, when the tubular end 10TE of the mastitis prevention sheet 10 is closed below the nipple orifice NA, a space can be formed in which milk M secreted from the nipple orifice NA can accumulate.

[0119] (6) When the mastitis prevention sheet 10 is attached to the nipple N, the through hole 10H can be positioned below the nipple opening NA, so that milk secreted from the nipple opening NA can be discharged from the space surrounded by the sheet body 10B through the through hole 10H.

[0120] (7) When the length of the through hole 10H is 1 mm or more and 4 mm or less, it is possible to increase the reliability of the mastitis prevention sheet 10 adhering to the nipple N and also to increase the reliability of milk M being discharged through the through hole 10H.

[0121] (8) If the total light transmittance of the sheet body 10B is 30% or more, when the sheet body 10B is attached to the nipple N, it is possible to observe the nipple N through the sheet body 10B.

[0122] The above-described embodiment can be modified and implemented as follows. [Method of using the mastitis prevention sheet] The mastitis prevention sheet 10 may be attached to the nipple N by the following method. First, as shown in Figure 6, a part of the mastitis prevention sheet 10 is positioned on the nipple N. Next, the protective layer 13 is peeled off from the base layer 11 while the mastitis prevention sheet 10 is wrapped around the nipple N. The surface of the base layer 11 that comes into contact with the adhesive layer 12 and from which the protective layer 13 has been peeled off is the adhered surface. A first part of the adhesive surface 12S of the adhesive layer 12 is brought into close contact with a first part of the adhered surface of the base layer 11, and the sheet body 10B can be attached to the nipple N in a state where the sheet body 10B has a tubular shape that surrounds the nipple N.

[0123] The above-described method can provide the following effects: (9) The adhesive portion formed by adhering the first portion of the adhesive surface 12S to the first portion of the surface to be adhered is less susceptible to the spread of milk M secreted from the nipple opening, and therefore the adhesive layer 12 is less likely to peel off from the nipple N.

[0124] [Through holes] The mastitis prevention sheet 10 does not have to have through holes 10H. Even in this case, if the mastitis prevention sheet 10 satisfies conditions 1 and 2, it is possible to obtain the effect equivalent to (1) above.

[0125] The mastitis prevention sheet 10 may have through holes extending along the short sides. Even in this case, it is possible to discharge milk M through the through holes by squeezing the teats N of the dairy cow C together with the mastitis prevention sheet 10.

[0126] [Total Light Transmittance] Only a portion of the sheet body 10B may have a total light transmittance of 30% or more. That is, the sheet body 10B may have a transmitting portion that is a portion of the sheet body 10B and has a total light transmittance of 30% or more. In this case, the following effects can be obtained.

[0127] (10) Through the transparent portion, it is possible to visually observe the state of the nipple N or the state of the space formed below the nipple N.

[0128] The total light transmittance of the sheet body 10B may be less than 30%. Even in this case, the mastitis prevention sheet 10 can achieve the effect equivalent to that of (1) above by satisfying conditions 1 and 2.

Claims

1. A method for using a mastitis prevention sheet for livestock which has an antibacterial effect and comprises a base layer and an adhesive layer which contains chitosan and is supported on the base layer, the adhesive layer having an adhesive surface on the side opposite to the side facing the base layer, the method comprising: attaching the mastitis prevention sheet to the nipple so that the mastitis prevention sheet has a tubular shape surrounding the nipple; and closely adhering a first part of the adhesive surface to a second part of the adhesive surface at a position away from the nipple orifice of the nipple so as to seal the tubular end of the mastitis prevention sheet.

2. A method of using the mastitis prevention sheet described in claim 1, wherein attaching the mastitis prevention sheet to the nipple includes adhering the third part of the adhesive surface to the fourth part of the adhesive surface, so that the mastitis prevention sheet has a tubular shape surrounding the nipple.

3. A method of using the mastitis prevention sheet described in claim 1, wherein the surface of the base layer opposite the surface facing the adhesive layer is an adhesive surface, and attaching the mastitis prevention sheet to the nipple includes adhering a third part of the adhesive surface to a first part of the adhesive surface of the base layer, thereby attaching the mastitis prevention sheet to the nipple so that the mastitis prevention sheet has a tubular shape surrounding the nipple.

4. A method of using a mastitis prevention sheet described in any one of claims 1 to 3, wherein the mastitis prevention sheet has a through hole penetrating the mastitis prevention sheet in the thickness direction of the mastitis prevention sheet, and attaching the mastitis prevention sheet includes attaching the mastitis prevention sheet to the nipple so that the through hole is positioned at the tubular end of the mastitis prevention sheet.

5. A method for using the mastitis prevention sheet according to claim 4, further comprising discharging milk from the through holes located at the tubular end of the mastitis prevention sheet.

6. A mastitis prevention sheet having antibacterial properties, comprising a base layer and an adhesive layer containing 2% by mass or more of chitosan and supported by the base layer, wherein the adhesive layer has an adhesive surface on the side opposite to the surface facing the base layer, and the adhesion strength between a first portion of the adhesive surface and a second portion of the adhesive surface is 2 N / 25 mm or more and 10 N / 25 mm or less.

7. A mastitis prevention sheet as described in claim 6, wherein when viewed from a viewpoint opposite to the plane in which the mastitis prevention sheet spreads, the mastitis prevention sheet comprises a band-shaped portion along the outer edge of the mastitis prevention sheet, and a through hole that penetrates the mastitis prevention sheet along the thickness direction of the mastitis prevention sheet, is located in the band-shaped portion, and has a shape extending along the outer edge of the mastitis prevention sheet.

8. A mastitis prevention sheet as described in claim 7, wherein the length of the through holes is 1 mm or more and 4 mm or less when viewed from a viewpoint opposite to the plane on which the mastitis prevention sheet spreads.

9. A mastitis prevention sheet as described in any one of claims 6 to 8, wherein the adhesive layer is in contact with the base material layer, and the total light transmittance in at least a part of the sheet body composed of the adhesive layer and the base material layer is 30% or more.

10. A method for manufacturing a mastitis prevention sheet for livestock having an antibacterial effect, comprising a base layer and an adhesive layer containing chitosan and supported on the base layer, the method comprising: forming the base layer; forming the adhesive layer containing 2 mass% or more of chitosan, the adhesive layer having an adhesion strength of 2 N / 25 mm or more and 10 N / 25 mm or less between a first part of the adhesive surface, which is the surface opposite to the surface facing the base layer, and a second part of the adhesive surface; and bonding the adhesive layer to the base layer, wherein forming the adhesive layer comprises using an acidic aqueous solution containing the chitosan.

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