Nonwoven sheet, packaging material for sterilization, and lid material for sterilization

Abstract

[Problem] To prevent fibers of a nonwoven sheet from being exposed to the outside when a packaging material for sterilization is opened. [Solution] This nonwoven sheet 10 comprises a nonwoven sheet body 11, a barrier layer 12 partially entering the nonwoven sheet body 11, and a heat seal layer 13 provided on the barrier layer 12. The nonwoven sheet 10 has air permeability.

Description

Nonwoven sheets, sterilization packaging materials, and sterilization lid materials

[0001] The present invention relates to a nonwoven sheet, a packaging material for sterilization, and a lid material for sterilization.

[0002] Conventionally, there have been known breathable sterilization packaging materials for storing medical instruments, or breathable sterilization lids that can be attached to containers for storing medical instruments. Such sterilization packaging materials or sterilization lids are made of nonwoven fabric, and this nonwoven fabric is heat-sealed to a mating material such as a synthetic resin film substrate or a synthetic resin container.

[0003] Medical instruments are stored in sterilization packaging materials or in synthetic resin containers. After the medical instruments have been sterilized, the sterilization packaging materials are opened or the sterilization lids are peeled off from the containers when the medical instruments are to be used.

[0004] However, when the sterilization packaging material is opened or the sterilization lid material is peeled off from the container, some fibers of the nonwoven fabric may remain on the other material and be exposed to the outside.

[0005] If some fibers of the nonwoven fabric remain on the mating material and are exposed to the outside, it is conceivable that these fibers may become contaminated as foreign matter in the medical device.

[0006] JP 2007-1584 A JP 2007-331781 A JP 2011-245734 A

[0007] The present disclosure has been made in consideration of these points, and aims to provide a nonwoven sheet, a sterilization packaging material, and a sterilization lid material that, when the sterilization packaging material is opened or the sterilization lid material is peeled off from the container, does not expose fibers to the outside and become mixed into medical instruments as foreign matter.

[0008] A first aspect of the present disclosure is a breathable nonwoven sheet comprising a nonwoven sheet body, a sealing layer provided on the nonwoven sheet body and partially extending into the nonwoven sheet body, and a heat seal layer provided on the sealing layer.

[0009] A second aspect of the present disclosure is the nonwoven sheet of the first aspect, wherein the sealing layer contains a styrene-acrylic resin.

[0010] A third aspect of the present disclosure is the nonwoven sheet of either the first or second aspect, wherein the heat seal layer contains a polyolefin resin.

[0011] A fourth aspect of the present disclosure is a nonwoven sheet in any one of the first to third aspects, wherein the nonwoven sheet body includes high-density polyethylene spunbond nonwoven fabric, sterilized paper, kraft paper, pure white paper, fine paper, coated paper, or art paper.

[0012] A fifth aspect of the present disclosure is the nonwoven sheet of any one of the first to fourth aspects, wherein the nonwoven sheet has an air permeability of 20 to 1500 s / 100 ml.

[0013] A sixth aspect of the present disclosure is the nonwoven sheet of any one of the first to fifth aspects, wherein the filling layer has a thickness of 0.5 μm or more and 15 μm or less.

[0014] A seventh aspect of the present disclosure is a nonwoven sheet in any one of the first to sixth aspects, wherein the heat seal layer has a thickness of 2 μm or more and 30 μm or less.

[0015] The eighth form of the present disclosure is a packaging material for sterilization, comprising a nonwoven sheet of any one of the first to seventh forms and a base film made of synthetic resin laminated on the heat seal layer of the nonwoven sheet, and obtained by bonding the nonwoven sheet and the base film together around their peripheries, leaving an opening.

[0016] A ninth form of the present disclosure is a sterilization lid material that is adhered to the flange portion of a synthetic resin container having a container body and a flange portion, the sterilization lid material comprising a nonwoven sheet of any of the first to seventh forms.

[0017] According to the present disclosure, when the sterilization packaging material is opened or the sterilization lid material is peeled off from the container, the fibers are not exposed to the outside, and the fibers do not become mixed into the medical instrument as foreign matter.

[0018] FIG. 1 is a side cross-sectional view showing a sterilization packaging material including a nonwoven sheet according to a first embodiment of the present disclosure. FIG. 2 is a side cross-sectional view showing a nonwoven sheet. FIG. 3 is a diagram showing the state in which both side edges of a nonwoven sheet and a base film are heat-sealed. FIG. 4 is a diagram showing the state in which a medical instrument is contained in a bag made of sterilization packaging material. FIG. 5 is a diagram showing a process for manufacturing a nonwoven sheet. FIG. 6 is a diagram showing the process of cutting a web-like nonwoven sheet to produce elongated nonwoven sheets. FIG. 7A is a diagram showing the side edge heat-sealed portion and the "inverted V"-shaped heat-sealed portion of the sterilization packaging material. FIG. 7B is a diagram showing a modified version of the sterilization packaging material shown in FIG. 7A. FIG. 7C is a diagram showing a modified version of the sterilization packaging material shown in FIG. 7A. FIG. 7D is a diagram showing a modified version of the sterilization packaging material shown in FIG. 7A. FIG. 8 is a diagram showing a cross-sectional image of a nonwoven sheet. FIGS. 9(A), (B), and (C) are diagrams showing images of the heat-sealed layer of the sterilization packaging material after opening. 10(A), 10(B), and 10(C) are images showing the heat-seal layer of a sterilization packaging material after opening. Fig. 11 is a diagram showing a specific example of the present disclosure. Fig. 12 is a diagram showing a sterilization lid material including a nonwoven sheet according to a second embodiment of the present disclosure.

[0019] First Embodiment Next, a first embodiment of the present disclosure will be described with reference to the drawings.

[0020] 1 to 11 are diagrams showing an embodiment of the present disclosure.

[0021] First, the sterilization packaging material 1 for storing medical instruments will be described with reference to Figures 1 to 4 and 7A. As shown in Figures 1 to 4 and 7A, the sterilization packaging material 1 is breathable. An internal space 1a is formed inside the sterilization packaging material 1, and medical instruments 5 are stored in this internal space 1a.

[0022] Such a sterilization packaging material 1 comprises a nonwoven sheet 10 that is impermeable to microorganisms but breathable, and a base film 2 made of synthetic resin laminated on the nonwoven sheet 10. By heat-sealing the periphery of the nonwoven sheet 10 and the base film 2, a heat-sealed portion 3 is formed on the periphery, and in this way a sterilization packaging material 1 having an internal space 1a is obtained.

[0023] 1 is a side cross-sectional view showing the packaging material for sterilization 1, and FIGS. 3 and 7A are views of the packaging material for sterilization 1 as seen from the base film 2 side.

[0024] As described above, the sterilization packaging material 1 is produced by overlapping the base film 2 on the nonwoven sheet 10 and heat-sealing both side edges parallel to the longitudinal direction L of the nonwoven sheet 10 and the base film 2. In this case, side edge heat-sealed portions 3a are formed by heat-sealing both side edges of the nonwoven sheet 10 and the base film 2. In addition, heat-sealed portions 3b shaped like an inverted V in plan view are formed so as to overlap with the side edge heat-sealed portions 3a on both side edges of the nonwoven sheet 10 and the base film 2, and the side edge heat-sealed portions 3a on both side edges of the nonwoven sheet 10 and the base film 2 and the heat-sealed portions 3b shaped like an inverted V in plan view constitute the heat-sealed portion 3. The nonwoven sheet 10 and the base film 2 form the sterilization packaging material 1 having an internal space 1a. On the side of the internal space 1a opposite the inverted V-shaped heat-sealed portion 3b, an opening 7 is formed by cutting the sterilization packaging material 1 in a direction perpendicular to the longitudinal direction L (see FIG. 7A ).

[0025] In this embodiment, a sterilization packaging material 1 having an internal space 1a is formed by the nonwoven sheet 10 and the base film 2. An opening 7 is provided in the sterilization packaging material 1 to form a bag 1A for storing a medical instrument 5. After the medical instrument 5 is stored in the internal space 1a through the opening 7, the opening 7 is heat-sealed to close the opening, thereby storing the medical instrument 5 in the breathable bag 1A.

[0026] Of the heat-sealed portions 3, heat-sealed portions 3b that are shaped like an inverted V in plan view and overlap with side edge heat-sealed portions 3a at the side edges protrude outward in the longitudinal direction L. When removing the medical device 5 from the internal space 1a of the bag 1A, the base film 2 can be easily peeled from the nonwoven sheet 10 from the tip of the inverted V-shaped heat-sealed portion 3b toward the inside in the longitudinal direction L. In this way, the bag 1B can be opened from the heat-sealed portion 3b, and the medical device 5 in the internal space 1a can be removed.

[0027] Next, the nonwoven sheet 10 will be described below.

[0028] As shown in Figures 1 and 2, the nonwoven sheet 10 comprises a nonwoven sheet body 11, a sealing layer 12 provided on the nonwoven sheet body 11 and partially extending into the nonwoven sheet body 11, and a heat seal layer 13 provided on the sealing layer 12.

[0029] In this embodiment, the nonwoven sheet body 11 is made of a cloth-like sheet with no woven fibers.

[0030] In this embodiment, the nonwoven sheet body 11 is impermeable to microorganisms but breathable, and includes "paper" and "nonwoven fabric." Of these, "paper" is a thin, flat sheet made by entangling fibers from plants, etc., while "nonwoven fabric" is a sheet made by collecting fibers in a fixed or random direction and bonding them with an adhesive resin, mechanically entangling them, or fusing the fibers together. The material of the nonwoven sheet body 11 will be described later.

[0031] Next, each of the components that make up the nonwoven sheet 10 will be described.

[0032] As described above, the nonwoven sheet 10 comprises the nonwoven sheet body 11 , the sealing layer 12 , and the heat seal layer 13 .

[0033] The nonwoven sheet body 11 has a basis weight of 20 g / m ２ ~90g / m ２ For example, a paper or nonwoven fabric having a basis weight of 75 g / m ２ Here, the spunbond nonwoven fabric refers to a nonwoven fabric of the direct spun type.

[0034] The sealing layer 12 may be made of a styrene-acrylic resin or an ethylene-vinyl acetate copolymer resin (EVA resin).

[0035] Furthermore, the heat seal layer 13 may be made of a polyolefin-based material, such as a polyethylene-based or polypropylene-based material.

[0036] In this embodiment, a portion of the sealing layer 12 provided on the nonwoven sheet main body 11 penetrates into the fiber pores of the nonwoven sheet main body 11. The nonwoven sheet main body 11 contains a plurality of fibers, resulting in a lack of uniformity in the fiber pores. In this embodiment, a portion of the sealing layer 12 penetrates into the pores of the nonwoven sheet main body 11 and adheres to the nonwoven sheet main body 11, thereby exerting an anchoring effect. Therefore, when the sterilization packaging material 1 is opened, the nonwoven sheet 10 and the base film 2 are peeled apart, but interlayer delamination does not occur between the nonwoven sheet main body 11 and the sealing layer 12. When the nonwoven sheet 10 and the base film 2 are peeled apart, interlayer delamination occurs between the sealing layer 12 and the heat-seal layer 13, or cohesive delamination occurs within the heat-seal layer 13, causing the heat-seal layer 13 to move toward the base film 2. In this manner, the nonwoven sheet 10 and the base film 2 are peeled apart.

[0037] Therefore, when the sterilization packaging material 1 is opened, some of the fibers of the nonwoven sheet body 11 do not migrate to the base film 2 side together with the heat seal layer 13 and are not exposed to the outside, and the exposed fibers of the nonwoven sheet body 11 do not get mixed into the medical instrument 5 as foreign matter.

[0038] In other words, if a heat seal layer is provided directly on the nonwoven sheet body without providing a sealing layer, when the sterilization packaging material is opened, some of the fibers of the nonwoven sheet body may migrate to the base film side along with the heat seal layer and be exposed to the outside.

[0039] According to this embodiment, when the sterilization packaging material 1 is opened as described above, interlayer delamination occurs between the sealing layer 12 and the heat-seal layer 13, or cohesive delamination occurs within the heat-seal layer 13, and the heat-seal layer 13 moves toward the base film 2.

[0040] Therefore, when the sterilization packaging material 1 is opened, some of the fibers of the nonwoven sheet body 11 will not migrate to the base film 2 side along with the heat seal layer 13, and some of the fibers of the nonwoven sheet body 11 will not be mixed into the medical instrument 5.

[0041] In this embodiment, a multilayer or single-layer film can be used as the base film 2. Each layer of the film can be made of a polyethylene resin, a polyethylene terephthalate resin, or a mixture thereof. For example, the base film 2 can be a polyethylene / polyethylene terephthalate film, a polyethylene film, or a polyethylene terephthalate film.

[0042] Next, the operation of this embodiment having such a configuration will be described.

[0043] First, a method for manufacturing a nonwoven sheet 10 will be described with reference to Fig. 5. As shown in Fig. 5, a web-like nonwoven sheet body 11 is fed from a paper feeder 30, and the nonwoven sheet body 11 is supplied between a gravure plate cylinder 31 and an impression cylinder 32. In this case, the nonwoven sheet body 11 has a basis weight of, for example, 20 g / m2 to 90 g / m2, preferably 75 g / m2. ２ High density polyethylene spunbond nonwoven fabric is used.

[0044] Next, the coating liquid to be the sealing layer 12 in the ink pan 41 is supplied from the furnisher roll 42 onto the gravure plate cylinder 31. The coating liquid on the gravure plate cylinder 31 is scraped off by a doctor blade 43, and then applied to the surface of the nonwoven sheet body 11 supplied between the gravure plate cylinder 31 and the impression cylinder 32.

[0045] Thereafter, the nonwoven sheet body 11 having the coating liquid applied to its surface is sent to the drying hood 33 .

[0046] The coating liquid for the sealing layer 12 stored in the ink pan 41 contains a styrene-acrylic resin and also contains water as a diluent. The diluent containing water is removed from the coating liquid applied to the surface of the nonwoven sheet body 11 sent to the drying hood 33, and the coating liquid is applied to the surface of the nonwoven sheet body 11 in a concentration of 1 to 10 g / m as a solid content. ２In this embodiment, the coating liquid for the filling layer 12 contains a styrene-acrylic resin component (approximately 39% by weight), a water component (approximately 60% by weight), and an additive component. In this case, the filling layer 12 has a thickness of 0.5 μm or more and 15 μm or less, preferably 1.0 μm or more and 4.0 μm or less, and a part of the filling layer 12 penetrates into the nonwoven sheet main body 11.

[0047] Next, the web-like nonwoven sheet body 11 is fed between a gravure plate cylinder 35 and an impression cylinder 36 .

[0048] During this time, the coating liquid in the ink pan 45 that will become the heat seal layer 13 is supplied from the furnisher roll 46 onto the gravure plate cylinder 35. The coating liquid on the gravure plate cylinder 35 is scraped off by a doctor blade 47, and then applied to the surface of the nonwoven sheet body 11 that is supplied between the gravure plate cylinder 35 and the impression cylinder 36.

[0049] Thereafter, the nonwoven sheet body 11 having the coating liquid applied to its surface is sent to the drying hood 37 .

[0050] The coating liquid for the heat seal layer 13 stored in the ink pan 45 contains a polyolefin resin and also contains water as a diluent. The diluent, including water, is removed from the coating liquid applied to the surface of the nonwoven sheet body 11 sent to the drying hood 37, and the coating liquid is applied to the surface of the nonwoven sheet body 11 in a concentration of 2 to 15 g / m2 as a solid content. ２ In this embodiment, the coating liquid for the heat-seal layer 13 contains a polyolefin resin component (approximately 26% by weight), a water component (approximately 73% by weight), and an additive component. In this case, the heat-seal layer 13 has a thickness of 2 μm or more and 30 μm or less, preferably 5 μm or more and 15 μm or less. Specifically, a polyethylene aqueous dispersion resin can be used as the coating liquid for the heat-seal layer 13.

[0051] In this way, the sealing layer 12 and the heat seal layer 13 are formed in this order on the surface of the nonwoven sheet body 11, thereby obtaining the nonwoven sheet 10. The nonwoven sheet 10 thus formed is wound up in the winding section 40.

[0052] The nonwoven sheet 10 wound in the winding section 40 has an air permeability of 20 s / 100 ml or more and 1500 s / 100 ml or less. The air permeability here is a value in accordance with the Oken method of JIS P8117:2009.

[0053] In this embodiment, the high-density polyethylene spunbond nonwoven fabric that forms the nonwoven sheet main body 11 has an air permeability of 8 s / 100 ml to 36 s / 100 ml. The nonwoven sheet 10 obtained by coating the sealing layer 12 and heat seal layer 13 on the nonwoven sheet main body 11 has a higher air permeability value (worsened air permeability) than the nonwoven sheet main body 11, but still has an air permeability of 20 s / 100 ml or more and 1500 s / 100 ml or less as described above, and is sufficiently breathable for the sterilization process described below. Here, the air permeability is a value based on the Gurley air permeability TAPPI T460.

[0054] Next, the web-like nonwoven sheet 10 is cut along cutting lines 10a extending in the longitudinal direction L to obtain a plurality of elongated nonwoven sheets 10 (see FIG. 6).

[0055] Next, the base film 2 is superimposed on the elongated nonwoven sheet 10 thus obtained, and the nonwoven sheet 10 and the base film 2 are heat-sealed together using a heat-sealing machine (not shown).

[0056] In this case, the nonwoven sheet 10 is superposed on the base film 2 with the heat seal layer 13 facing the base film 2 side.

[0057] By heat sealing using such a heat sealing machine, first, side edge heat-sealed portions 3a are formed on both side edges of the nonwoven sheet 10 and the base film 2 (see FIGS. 1 and 3). Next, heat-sealed portions 3b that are shaped like an inverted V in plan view are formed so as to intersect with the side edge heat-sealed portions 3a. The side edge heat-sealed portions 3a provided on both side edges of the nonwoven sheet 10 and the base film 2 and the heat-sealed portions 3b that are shaped like an inverted V in plan view constitute the heat-sealed portions 3 that join the nonwoven sheet 10 and the base film 2 (see FIG. 7A).

[0058] By heat-sealing the nonwoven sheet 10 and the base film 2 in this manner to form the side edge heat-sealed portion 3a and the heat-sealed portion 3b that is shaped like an inverted V in plan view, a sterilization packaging material 1 for storing a medical instrument 5 is obtained.

[0059] Thereafter, as shown in FIG. 7A, the sterilization packaging material 1 is cut in the front (upper in FIG. 7) and rear (lower in FIG. 7A) along the longitudinal direction L.

[0060] At this time, an opening 7 is formed below the packaging material for sterilization 1, and in this way, a bag body 1A having an internal space 1a is obtained from the packaging material for sterilization 1.

[0061] In Figure 7A, the inverted-V-shaped heat-sealed portion 3b of the heat-sealed portion 3 has a tip 3c that protrudes outward in the longitudinal direction L. The overlapping portion between the side edge heat-sealed portion 3a and the inverted-V-shaped heat-sealed portion 3b forms an overlapping portion 3d where heat sealing has been performed twice. The overlapping portion 3d, which is the overlapping portion between the side edge heat-sealed portion 3a and the inverted-V-shaped heat-sealed portion 3b in Figure 7A, will now be described in more detail. As shown in Figure 7A, when the inverted-V-shaped seal bar 50 that forms the inverted-V-shaped heat-sealed portion 3b consists only of a chevron portion 51, the overlapping portion 3d is the portion where the side edge heat-sealed portion 3a and the inverted-V-shaped heat-sealed portion 3b formed by the chevron portion 51 of the seal bar 50 overlap. 7D , when the inverted-V shaped seal bar 50 that forms the inverted-V shaped heat-sealed portion 3b has a mountain-shaped portion 51 and a pair of linear portions 52, 52 extending linearly from both ends of the mountain-shaped portion 51, the overlapping portion 3d is the portion where the side edge heat-sealed portion 3a overlaps with the portion of the seal bar 50 that corresponds to the mountain-shaped portion 51 and the portion that corresponds to the linear portion 52. In this way, by having the inverted-V shaped seal bar 50 have the mountain-shaped portion 51 and a pair of linear portions 52, 52 extending linearly from both ends of the mountain-shaped portion 51, the overlapping portion 3d can be reliably formed even if there is some misalignment between the side edge heat-sealed portion 3a and the portion that corresponds to the seal bar 50.

[0062] Next, the medical instrument 5 is placed into the internal space 1a through the opening 7, and the opening 7 of the bag body 1A is heat-sealed to close the entire periphery of the bag body 1A (see FIG. 4).

[0063] Thereafter, the bag body 1A, with the medical instrument 5 housed in the internal space 1a and the entire periphery closed, is placed in a gas sterilization chamber (not shown), and gas sterilization is performed on the bag body 1A in this gas sterilization chamber.

[0064] In this embodiment, the nonwoven sheet 10 of the bag body 1A is breathable, so that the medical instruments 5 inside the bag body 1A can be reliably sterilized by subjecting the bag body 1A to gas sterilization in a gas sterilization chamber.

[0065] When using the medical instrument 5 in a medical setting, the user first opens the bag 1A made of the sterilization packaging material 1. At this time, the user tears the inverted V-shaped heat-sealed portion 3b of the heat-sealed portion 3 from the tip end 3c protruding outward in the longitudinal direction L.

[0066] In this case, the inverted V-shaped heat-sealed portion 3b is easily torn from the tip portion 3c protruding outward in the longitudinal direction L, and in this way the bag 1A made of the sterilization packaging material 1 is opened.

[0067] Thereafter, the medical instrument 5 is taken out from the internal space 1a of the bag body 1A and used.

[0068] In this embodiment, a portion of the sealing layer 12 provided on the nonwoven sheet body 11 penetrates into the fiber pores of the nonwoven sheet body 11. Generally, the nonwoven sheet body 11 contains a plurality of fibers, and the fiber pores lack uniformity.

[0069] According to this embodiment, the sealing layer 12 provided on the nonwoven sheet main body 11 exhibits an anchoring effect by partially penetrating into the meshes of the nonwoven sheet main body 11 and adhering to the nonwoven sheet main body 11. Therefore, when the bag 1A made of the sterilization packaging material 1 is opened, the nonwoven sheet 10 and the base film 2 are peeled apart. At this time, no interlayer delamination occurs between the nonwoven sheet main body 11 and the sealing layer 12, but interlayer delamination occurs between the sealing layer 12 and the heat-seal layer 13. Alternatively, cohesive delamination occurs within the heat-seal layer 13, causing the heat-seal layer 13 to migrate toward the base film 2. Therefore, when the bag 1A made of the sterilization packaging material 1 is opened, some of the fibers of the nonwoven sheet main body 11 do not migrate toward the base film 2 together with the heat-seal layer 13 and become exposed to the outside. Therefore, some of the fibers of the nonwoven sheet main body 11 exposed to the outside do not get mixed into the medical device 5 as foreign matter.

[0070] Next, specific examples of the present disclosure will be described with reference to FIGS. 8 to 11. FIG.

[0071] This embodiment corresponds to the first embodiment shown in FIGS. 1 to 7A.

[0072] In this example, the nonwoven sheet body 11 is first made of a nonwoven fabric having a basis weight of 75 g / m ２ A spunbond nonwoven fabric made of high-density polyethylene was prepared. This nonwoven fabric has good bacterial barrier properties, and in order to maintain this bacterial barrier property, it was not subjected to a corona treatment.

[0073] Next, the coating liquid to be the sealing layer 12 in the ink pan 41 is supplied from the furnisher roll 42 onto the gravure plate cylinder 31. The coating liquid on the gravure plate cylinder 31 is scraped off by a doctor blade 43, and then applied to the surface of the nonwoven sheet body 11 supplied between the gravure plate cylinder 31 and the impression cylinder 32.

[0074] Thereafter, the nonwoven sheet body 11 having the coating liquid applied to its surface is sent to the drying hood 33 .

[0075] The coating liquid for the sealing layer 12 stored in the ink pan 41 contains a styrene-acrylic resin and also contains water as a diluent. The diluent containing water is removed from the coating liquid applied to the surface of the nonwoven sheet body 11 sent to the drying hood 33, and the coating liquid is applied to the surface of the nonwoven sheet body 11 in a concentration of 1 to 10 g / m as a solid content. ２ In this embodiment, the coating liquid for the filling layer 12 contains a styrene-acrylic resin component (approximately 39% by weight), a water component (approximately 60% by weight), and an additive component. In this case, the filling layer 12 has a thickness of 0.5 μm or more and 15 μm or less, preferably 1.0 μm or more and 4.0 μm or less, and a part of the filling layer 12 penetrates into the nonwoven sheet main body 11.

[0076] Next, the web-like nonwoven sheet body 11 is fed between a gravure plate cylinder 35 and an impression cylinder 36 .

[0077] During this time, the coating liquid in the ink pan 45 that will become the heat seal layer 13 is supplied from the furnisher roll 46 onto the gravure plate cylinder 35. The coating liquid on the gravure plate cylinder 35 is scraped off by a doctor blade 47, and then applied to the surface of the nonwoven sheet body 11 that is supplied between the gravure plate cylinder 35 and the impression cylinder 36.

[0078] Thereafter, the nonwoven sheet body 11 having the coating liquid applied to its surface is sent to the drying hood 37 .

[0079] The coating liquid for the heat seal layer 13 stored in the ink pan 45 contains a polyolefin resin and also contains water as a diluent. The diluent, including water, is removed from the coating liquid applied to the surface of the nonwoven sheet body 11 sent to the drying hood 37, and the coating liquid is applied to the surface of the nonwoven sheet body 11 in a concentration of 2 to 15 g / m2 as a solid content. ２ In this embodiment, the coating liquid for the heat-seal layer 13 contains a polyolefin resin component (approximately 26% by weight), a water component (approximately 73% by weight), and an additive component. In this case, the heat-seal layer 13 has a thickness of 2 μm or more and 30 μm or less, preferably 5 μm or more and 15 μm or less. Specifically, a polyethylene aqueous dispersion resin can be used as the coating liquid for the heat-seal layer 13.

[0080] In this way, the sealing layer 12 and the heat seal layer 13 are formed in this order on the surface of the nonwoven sheet body 11, thereby obtaining the nonwoven sheet 10. The nonwoven sheet 10 thus formed is wound up in the winding section 40.

[0081] On the other hand, a base film 2 was prepared from a film having the following structure: a polyethylene / polyethylene terephthalate film, a polyethylene film, or a polyethylene terephthalate film.

[0082] The rolled nonwoven sheet 10 was then cut along the longitudinal direction L to produce elongated nonwoven sheets 10. Next, the elongated nonwoven sheet 10 having the above-described configuration was overlapped with the base film 2 and heat-sealed to form the heat-sealed portion 3. In this case, the nonwoven sheet 10 was overlapped with the base film 2 so that the heat-sealed layer 13 faces the base film 2. In addition, a polyethylene layer was provided on at least the nonwoven sheet 10 side of the base film 2.

[0083] In this way, a packaging material for sterilization 1 was obtained, which was provided with a nonwoven sheet 10 and a base film 2, and in which the nonwoven sheet 10 and the base film 2 were joined by a heat-sealed portion 3.

[0084] In this example, as shown in FIG. 11, the solid content in the coating layer for the filling layer is 1.2 to 5.2 g / m ２ The solid content in the coating layer for the heat seal layer is 2.0 to 5.0 g / m ２ It was.

[0085] The air permeability of the sterilization packaging material 1 was 83 to 952 (s / 100 ml). The general required air permeability of a sterilization packaging material is 1000 (s / 100 ml), so the sterilization packaging material 1 maintained sufficient air permeability.

[0086] The heat seal strength (HS strength) of the heat seal portion 3 joining the nonwoven sheet 10 and the base film 2 was 1.2 to 4.2 (N / 15 mm width), ensuring sufficient heat seal strength.

[0087] Next, the nonwoven sheet according to this embodiment will be described in detail with reference to FIGS. 8 to 10(A), (B) and (C).

[0088] Here, Figure 8 is a diagram showing an image of the cross section of the nonwoven sheet, and Figures 9(A), (B), (C) and Figures 10(A), (B), and (C) are diagrams showing images of the heat seal layer after the sterilization packaging material has been opened.

[0089] As shown in Figures 8 and 11, in a nonwoven sheet 10, the sealing layer 12 provided on the nonwoven sheet main body 11 had a thickness of 1.93 µm or more and 3.30 µm or less, and the heat-seal layer 13 provided on the sealing layer 12 had a thickness of 11.28 µm or more and 12.65 µm or less. In this case, the thickness of the sealing layer 12 and the thickness of the heat-seal layer 13 were both obtained by visually measuring the distance between two points spaced apart in the vertical direction at 10 points in the cross-sectional image of the nonwoven sheet shown in Figure 8 and averaging the measured values. Here, the cross-sectional image of the nonwoven sheet shown in Figure 8 was an image captured using the following laser microscope: Keyence Corporation Color 3D Laser Microscope VK-8710. Imaging conditions: 50x objective lens, 1000x magnification on a 15-inch monitor. The cross-sectional image shown in Figure 8 was obtained by slicing a nonwoven fabric sample with a sliding microtome and observing the cross section of the sliced ​​sample. The ten measurement points were selected at approximately equal intervals from an arbitrary width of about 100 μm on the sliced ​​nonwoven fabric sample.

[0090] 9(A), (B), and (C) illustrate the heat-seal layer 13 that has migrated toward the base film 2 at the leading end 3c of the heat-seal layer 13. In this case, FIGS. 9(A), (B), and (C) show images of the heat-seal layer 13 magnified 20 times, 100 times, and 500 times compared to visual observation, respectively. As shown in FIGS. 9(A), (B), and (C), no fibers of the nonwoven sheet body 11 were observed on the heat-seal layer 13 in any case.

[0091] 10(A), (B), and (C) illustrate the heat-sealed layer 13 that has migrated toward the base film 2 in the overlapping portion 3d of the heat-sealed portion 3. In this case, FIGS. 10(A), (B), and (C) show images of the heat-sealed layer 13 at magnifications of 20x, 100x, and 500x, respectively, compared to visual observation. As shown in FIGS. 10(A), (B), and (C), no fibers of the nonwoven sheet body 11 were observed on the heat-sealed layer 13 in any case. The images of the heat-sealed layer shown in FIGS. 9(A), (B), and (C) and 10(A), (B), and (C) were captured using the laser microscope described above.

[0092] In this example, the coating liquid for the sealing layer and the coating liquid for the heat-sealing layer that are applied to the nonwoven sheet body 11 both contain water as a diluent. Therefore, when the nonwoven sheet body 11 is sent to the drying hoods 33, 37 after application of the coating liquid, the diluent can be safely and reliably removed from the nonwoven sheet body 11 without particularly strong heating in the drying hoods 33, 37. Furthermore, because the coating liquid contains water as a diluent, the application of the coating liquid to the nonwoven sheet body 11 can be carried out safely compared to when a coating liquid containing an organic solvent is used.

[0093] Next, modified examples of the present disclosure will be described with reference to Figures 7B and 7C. The modified examples shown in Figures 7B and 7C differ from the first embodiment shown in Figure 7A only in the heat sealing configuration between the nonwoven sheet 10 and the base film 2, and other configurations are substantially the same as those of the first embodiment shown in Figure 7A. In the modified examples shown in Figures 7B and 7C, the same parts as those in the embodiment shown in Figure 7A are designated by the same reference numerals and detailed description will be omitted. Here, Figures 7B and 7C are views of the sterilization packaging material 1 as seen from the base film 2 side.

[0094] In the modified example shown in Figure 7B, the sterilization packaging material 1 is produced by overlapping the base film 2 on the nonwoven sheet 10 and heat-sealing both side edges parallel to the longitudinal direction L of the nonwoven sheet 10 and the base film 2. In this case, side edge heat-sealed portions 3a are formed by heat-sealing both side edges of the nonwoven sheet 10 and the base film 2. In addition, heat-sealed portions 3b shaped like an inverted V in plan view are formed so as to overlap with the side edge heat-sealed portions 3a on both side edges of the nonwoven sheet 10 and the base film 2, and the side edge heat-sealed portions 3a on both side edges of the nonwoven sheet 10 and the base film 2 and the heat-sealed portions 3b shaped like an inverted V in plan view constitute the heat-sealed portion 3. The nonwoven sheet 10 and the base film 2 form a sterilization packaging material 1 having an internal space 1a. On the side of the internal space 1a opposite the inverted V-shaped heat-sealed portion 3b, an opening 7 is formed by cutting the sterilization packaging material 1 in a direction perpendicular to the longitudinal direction L (see Figure 7B).

[0095] In this modification, a sterilization packaging material 1 having an internal space 1a is formed by the nonwoven sheet 10 and the base film 2. An opening 7 is then formed in the sterilization packaging material 1 to form a bag 1A for storing a medical instrument 5. After the medical instrument 5 is stored in the internal space 1a through the opening 7, the opening 7 is heat-sealed to close it, allowing the medical instrument 5 to be stored in a sterile state inside the breathable bag 1A.

[0096] Of the heat-sealed portions 3, heat-sealed portions 3b, which are shaped like an inverted V in plan view and intersect with the side edge heat-sealed portions 3a on the side edges, protrude outward in the longitudinal direction L. When removing the medical device 5 from the internal space 1a of the bag 1A, the base film 2 can be easily peeled from the nonwoven sheet 10 from the tip of the inverted V-shaped heat-sealed portion 3b toward the inside in the longitudinal direction L. In this way, the bag 1B can be opened from the heat-sealed portion 3b, and the medical device 5 in the internal space 1a can be removed.

[0097] In FIG. 7B , the inverted-V-shaped heat-sealed portion 3b of the heat-sealed portion 3 has a tip 3c that protrudes outward in the longitudinal direction L. The overlapping portion between the side edge heat-sealed portion 3a and the inverted-V-shaped heat-sealed portion 3b forms an overlapping portion 3d where heat sealing has been performed twice. As shown in FIG. 7B , the side edge heat-sealed portion 3a extends from the inverted-V-shaped heat-sealed portion 3b toward the opening 7 and terminates just before the opening 7. This allows the medical device 5 to be easily and simply placed into the internal space 1a through the opening 7. Furthermore, the side edge heat-sealed portion 3a does not extend from the inverted-V-shaped heat-sealed portion 3b to the side opposite the opening 7. The overlapping portion 3d, which is the overlapping portion between the side edge heat-sealed portion 3a and the inverted-V-shaped heat-sealed portion 3b in FIG. 7B , will now be described in more detail. 7B , when an "inverted-V" shaped seal bar 50 that forms an "inverted-V" shaped heat-sealed portion 3b has a mountain-shaped portion 51 and a pair of linear portions 52, 52 extending linearly from both ends of the mountain-shaped portion 51, the overlapping portion 3d is the portion where the side edge heat-sealed portion 3a and the portion of the seal bar 50 that corresponds to the linear portion 52 overlap. In this way, by having an "inverted-V" shaped seal bar 50 that has a mountain-shaped portion 51 and a pair of linear portions 52, 52 extending linearly from both ends of the mountain-shaped portion 51, the overlapping portion 3d can be reliably formed even if there is some misalignment between the side edge heat-sealed portion 3a and the portion that corresponds to the seal bar 50. As shown in Figure 7B, the inverted V-shaped seal bar 50 that forms the inverted V-shaped heat seal portion 3b has a mountain-shaped portion 51 and a pair of straight portions 52, 52 that extend linearly from both ends of the mountain-shaped portion 51, and the overlapping portion 3d is the portion where the side edge heat seal portion 3a and the portion of the seal bar 50 that corresponds to the straight portion 52 overlap.This configuration can also be applied to the overlapping portion 3d shown in Figure 7C, which will be described later.

[0098] 7C , the sterilization packaging material 1 is produced by overlapping the base film 2 on the nonwoven sheet 10 and heat-sealing both side edges parallel to the longitudinal direction L of the nonwoven sheet 10 and the base film 2. In this case, side edge heat-sealed portions 3a are formed by heat-sealing both side edges of the nonwoven sheet 10 and the base film 2. In addition, heat-sealed portions 3b shaped like an inverted V in plan view are formed so as to intersect with the side edge heat-sealed portions 3a on both side edges of the nonwoven sheet 10 and the base film 2. These side edge heat-sealed portions 3a on both side edges of the nonwoven sheet 10 and the base film 2 and the heat-sealed portions 3b shaped like an inverted V in plan view constitute the heat-sealed portion 3. The nonwoven sheet 10 and the base film 2 form the sterilization packaging material 1 having an internal space 1a. On the side of the internal space 1a opposite the inverted V-shaped heat-sealed portion 3b, an opening 7 is formed by cutting the sterilization packaging material 1 in a direction perpendicular to the longitudinal direction L (see FIG. 7C ).

[0099] In this modification, a sterilization packaging material 1 having an internal space 1a is formed by the nonwoven sheet 10 and the base film 2. An opening 7 is then provided in the sterilization packaging material 1 to form a bag 1A for storing a medical instrument 5. After the medical instrument 5 is stored in the internal space 1a through the opening 7, the opening 7 is heat-sealed to close the opening, thereby storing the medical instrument 5 in the breathable bag 1A.

[0100] Of the heat-sealed portions 3, heat-sealed portions 3b, which are shaped like an inverted V in plan view and intersect with the side edge heat-sealed portions 3a on the side edges, protrude outward in the longitudinal direction L. When removing the medical device 5 from the internal space 1a of the bag 1A, the base film 2 can be easily peeled from the nonwoven sheet 10 from the tip of the inverted V-shaped heat-sealed portion 3b toward the inside in the longitudinal direction L. In this way, the bag 1B can be opened from the heat-sealed portion 3b, and the medical device 5 in the internal space 1a can be removed.

[0101] In FIG. 7C , the inverted-V-shaped heat-sealed portion 3b of the heat-sealed portion 3 has a tip 3c that protrudes outward in the longitudinal direction L. The overlapping portion between the side edge heat-sealed portion 3a and the inverted-V-shaped heat-sealed portion 3b forms an overlapping portion 3d where heat sealing has been performed twice. As shown in FIG. 7C , the side edge heat-sealed portion 3a extends from the inverted-V-shaped heat-sealed portion 3b toward the opening 7 and terminates just before the opening 7. This allows the medical device 5 to be easily and simply placed in the internal space 1a through the opening 7. Furthermore, the side edge heat-sealed portion 3a does not extend from the inverted-V-shaped heat-sealed portion 3b to the side opposite the opening 7. In the modified example shown in FIG. 7C , the side edge heat-sealed portion 7a does not extend from the inverted-V-shaped heat-sealed portion 3b to the side opposite the opening 7. Instead, a pair of dot-like heat-sealed portions 3e is formed outside the internal space 1a defined by the inverted-V-shaped heat-sealed portion 3b. In FIG. 7C, the nonwoven sheet 10 and the base film 2 can be bonded together by heat sealing them at the pair of dotted heat-sealed portions 3e.

[0102] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Fig. 12. In the second embodiment shown in Fig. 12, a nonwoven sheet is used as a sterilization lid, and other configurations are substantially the same as those of the first embodiment shown in Figs. 1 to 10. As shown in Fig. 12, a synthetic resin container 20 having a container body 21 and a flange 22 may be prepared, and a nonwoven sheet 10 may be attached to the flange 22 of the container 20 by heat sealing. In Fig. 12, the container 20 is a single-layer container made of polyethylene terephthalate, a single-layer container made of polypropylene, or a multi-layer container made of polyethylene terephthalate / polypropylene. The nonwoven sheet 10 is overlapped with the heat-seal layer 13 facing the flange 22.

[0103] As shown in FIG. 12, the nonwoven sheet 10 attached to the flange portion 22 by heat sealing constitutes a sterilization lid material 25.

[0104] In this embodiment, the medical instrument 5 is first placed in the container 20, and the nonwoven sheet 10 is attached by heat sealing to the flange portion 22 so as to cover the container 20. In this case, the nonwoven sheet 10 serves as a lid material 25 for sterilization.

[0105] The container 20 can be produced by any molding method, such as injection molding, sheet molding, blow molding, etc. The container 20 can be closed by heat-sealing the nonwoven sheet 10 to the flange portion 22.

[0106] When the sterilization lid 25 is peeled off from the flange 22 of the container 20, the heat seal layer 13 of the sterilization lid 25 moves toward the flange 22. In this case, no fibers of the nonwoven sheet body 11 constituting the nonwoven sheet 10 remain on the heat seal layer 13 side, and therefore, the remaining fibers do not get mixed into the medical device 5.

[0107] DESCRIPTION OF SYMBOLS 1 Sterilization packaging material 1a Internal space 1A Bag body 2 Base film 3 Heat-sealed portion 3a Side edge heat-sealed portion 3b "Inverted V"-shaped heat-sealed portion 5 Medical instrument 7 Opening 10 Nonwoven sheet 10a Cutting line 11 Nonwoven sheet body 12 Sealing layer 13 Heat-sealed layer 20 Container 21 Container body 22 Flange portion 25 Sterilization lid material

Claims

1. A breathable nonwoven sheet comprising: a nonwoven sheet body; a sealing layer provided on the nonwoven sheet body, a portion of which extends into the nonwoven sheet body; and a heat seal layer provided on the sealing layer.

2. The nonwoven sheet according to claim 1, wherein the sealing layer contains a styrene-acrylic resin.

3. The nonwoven sheet according to claim 1 or 2, wherein the heat seal layer contains a polyolefin resin.

4. The nonwoven sheet according to claim 1, wherein the nonwoven sheet body comprises high-density polyethylene spunbond nonwoven fabric, sterilized paper, kraft paper, pure white paper, fine paper, coated paper, or art paper.

5. The nonwoven sheet according to claim 1, wherein the air permeability of the nonwoven sheet is 20 to 1500 s / 100 ml.

6. The nonwoven sheet according to claim 1, wherein the filling layer has a thickness of 0.5 μm or more and 15 μm or less.

7. The nonwoven sheet according to claim 1, wherein said heat seal layer has a thickness of 2 μm or more and 30 μm or less.

8. A packaging material for sterilization, comprising the nonwoven sheet according to claim 1 and a base film made of synthetic resin laminated on the heat seal layer of the nonwoven sheet, the packaging material being obtained by bonding the nonwoven sheet and the base film together around their peripheries, leaving an opening.

9. A sterilization lid material that is adhered to the flange of a synthetic resin container having a container body and a flange, the sterilization lid material comprising the nonwoven sheet according to claim 1.

Images