Foam

Abstract

To provide foam that has preferable adhesion to a wound and a skin surface and allows for efficient treatment of water content such as exudate and sweat from the wound and the skin surface.SOLUTION: A foam includes a first region part and a second region part. The second region part is arranged in an outer periphery of the first region part. The first region part has a first cell structure and the second region part has a second cell structure. The first cell structure and the second cell structure have structures different from each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to foams. [Background technology]

[0002] Foams are used in a variety of products that come into contact with the skin. Examples of such products include wound dressings, which are used to treat external wounds and surgical wounds. Wound dressings basically have the function of preventing infection from the outside by physically protecting the wound surface. There are various types of wound dressings, and they are appropriately selected and used depending on the condition of the wound and the purpose of the treatment.

[0003] One example of a wound dressing is a hydrocolloid material, which is a hydrophilic polymer dispersed in a hydrophobic polymer. The hydrophilic polymer in the hydrocolloid absorbs exudate from the wound surface and turns into a sol or gel. This is said to maintain a moist environment on the wound surface, promote wound healing, and relieve pain. Hydrocolloids are also used as skin adhesives for artificial anus appliances.

[0004] As an example of a wound dressing material, a so-called polyurethane foam material that includes a resin foam has been proposed (see Patent Document 1). Hereinafter, polyurethane foam material may be simply referred to as foam material or foam. The foam material includes a porous foam made by foaming urethane. When the foam is applied to the wound surface, the porous portion absorbs exudate.

[0005] Also, as an example of a wound dressing, a molded article has been proposed having a foam region and a compressed region, in which the compressed region is obtained by compressing a foam layer, and the foam layer and the foam region include a polyurethane material obtained by foaming and drying a composition containing an anionic hydrophilized polyurethane aqueous dispersion (see Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2000-175958 A [Patent Document 2] Special Publication No. 2012-500737 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the hydrocolloid material proposed in Patent Document 1 may not adhere well to the wound surface due to the influence of a relatively elastic hydrophobic polymer, etc., and may have a lower water absorption rate and amount compared to foam materials. In addition, the foam material proposed in Patent Document 2 also has a relatively elastic and resilient cell structure, so the adhesion between the wound and the foam at the interface between the wound surface and the foam is not sufficient, and the function of maintaining a moist environment on the wound surface and promoting wound healing may not be fully exhibited.

[0008] Therefore, a main object of the present invention is to provide a foam that has good adhesion to wounds and skin surfaces and can efficiently treat moisture such as exudate and sweat from wounds or skin surfaces. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides a foam comprising a first region and a second region, the second region being arranged around the outer periphery of the first region, the first region having a first cell structure and the second region having a second cell structure, the first cell structure and the second cell structure being different structures from each other. Effect of the Invention

[0010] According to the present invention, a foam can be provided that has good adhesion to a wound or skin surface and can efficiently treat moisture such as exudate and sweat from the wound or skin surface. The foam according to the present invention can provide a wound dressing that forms a sol on the wound application surface when applied to a wound, and has good adhesion to the wound or skin surface, and can efficiently treat moisture such as exudate and sweat from the wound or skin surface. The foam according to the present invention can provide a member for use in an ostomy appliance that has high adhesion to the skin surface and can efficiently treat moisture such as excreta from the stoma and sweat, for example, for wearers of ostomy appliances who sweat a lot. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the configuration of a foam according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of the configuration of a foam according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a diagram showing an example of the configuration of a wound dressing including a foam according to an embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing an example of the configuration of an excrement collection device including a foam according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic diagram of a cell structure possessed by a foam according to an embodiment of the present invention. [Figure 6] FIG. 6 is a schematic diagram of a cell structure possessed by a foam according to an embodiment of the present invention. [Figure 7] FIG. 7 is a video microscope photograph of the cell structure of the foam produced in Example 1. [Figure 8] FIG. 8 is a video microscope photograph of the cell structure of the foam produced in Example 2. [Figure 9] FIG. 9 shows the results of the complex modulus of the foams produced in Examples 1 and 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A preferred embodiment for carrying out the present invention will be described below. Note that the following description shows an example of a typical embodiment of the present invention, and the scope of the present invention should not be interpreted as being narrow.

[0013] A foam according to an embodiment of the present invention includes a first region and a second region, the second region is disposed around the outer periphery of the first region, the first region has a first cell structure, the second region has a second cell structure, and the first cell structure and the second cell structure are different from each other. In the foam according to the embodiment of the present invention, the first region may be disposed approximately in the center of the foam, and the second region may be disposed in the peripheral portion of the foam.

[0014] In the foam according to the embodiment of the present invention, it is preferable that the thickness of the first region is thicker than that of the second region. For example, the thickness of the first region may be in the range of 1,000 μm to 5,000 μm and the thickness of the second region may be in the range of 100 μm to 500 μm, and more preferably, the thickness of the first region may be in the range of 2,000 μm to 3,800 μm and the thickness of the second region may be in the range of 200 μm to 350 μm.

[0015] In the foam of the embodiment of the present invention, the first cell structure may have an open cell structure, and the second cell structure may have a closed cell structure. When the first cell structure has an open cell structure, the water absorption rate increases in the first region, for example, body fluids can be quickly absorbed, and the breathability, moisture permeability, and water evaporation properties are improved, making it difficult for skin maceration to occur. In addition, when the second cell structure has a closed cell structure, the water absorption rate and water absorption amount are suppressed in the second region, preventing the intrusion of water from the outside (the peripheral or edge portion of the foam), improving water resistance, making the foam of the embodiment of the present invention less likely to peel off, and preventing excess exudate absorbed in the first region from spreading to the surrounding area and causing maceration of healthy skin.

[0016] The open-cell structure is a structure made up of open cells, and an open cell is, for example, a cell that is connected to adjacent cells and is composed of at least two cells. The closed-cell structure is a structure made up of closed cells, and an closed cell is, for example, a cell that is not connected to adjacent cells.

[0017] In a foam according to an embodiment of the present invention, the first cell structure may have a first open-cell structure, the second cell structure may have a second open-cell structure, and a ratio of the first open-cell structure to the first cell structure may be greater than a ratio of the second open-cell structure to the second cell structure. Since the ratio of the first open-cell structure to the first cell structure is greater than the ratio of the second open-cell structure to the second cell structure, the first region has a faster water absorption rate than the second region, and therefore the first region can absorb body fluids such as exudate, blood, and sweat more quickly than the second region.

[0018] The ratio of the first open-cell structure to the first cell structure and the ratio of the second open-cell structure to the second cell structure may be a ratio by number or a ratio by volume. In the case of a ratio by number, it means the number of open cells in the first open-cell structure relative to the total number of closed cells and open cells in the first cell structure, and the number of open cells in the second open-cell structure relative to the total number of closed cells and open cells in the second cell structure. In the case of a ratio by volume, it means the volume of open cells in the first open-cell structure relative to the total volume of closed cells and open cells in the first cell structure, and it means the volume of open cells in the second open-cell structure relative to the total volume of closed cells and open cells in the second cell structure. The first open-cell structure is a structure made up of open cells, and the second open-cell structure is a structure made up of open cells, where open cells are, for example, those that are connected to adjacent cells and are composed of at least two cells.

[0019] In the foam of the embodiment according to the present invention, the first cell structure may have a first closed cell structure, and the second cell structure may have a second closed cell structure, and the ratio of the first closed cell structure to the first cell structure may be smaller than the ratio of the second closed cell structure to the second cell structure. By making the ratio of the first closed cell structure to the first cell structure smaller than the ratio of the second closed cell structure to the second cell structure, the water absorption speed and amount of the second region is further reduced relative to the first region, preventing the intrusion of moisture from the outside (periphery or edge of the foam), improving the water resistance of the second region, making the foam of the embodiment according to the present invention less likely to peel off, and preventing excess exudate absorbed in the first region from spreading to the surrounding area and causing maceration of healthy skin.

[0020] The ratio of the first closed cell structure to the first cell structure and the ratio of the second closed cell structure to the second cell structure may be a ratio by number or a ratio by volume. In the case of a ratio by number, the ratio is the number of closed cells in the first closed cell structure relative to the total number of closed cells and open cells in the first cell structure, and the number of closed cells in the second closed cell structure relative to the total number of closed cells and open cells in the second cell structure. In the case of a ratio by volume, the ratio is the volume of closed cells in the first closed cell structure relative to the total volume of closed cells and open cells in the first cell structure, and the ratio is the volume of closed cells in the second closed cell structure relative to the total volume of closed cells and open cells in the second cell structure. The first closed cell structure is a structure made up of closed cells, and the second closed cell structure is a structure made up of closed cells, where closed cells are, for example, cells that are not connected to adjacent cells.

[0021] In the foam of the embodiment of the present invention, it is preferable that the first region and / or the second region have adhesiveness, and it is more preferable that both the first region and the second region have adhesiveness. When the first region and / or the second region have adhesiveness, the foam adheres well to the body surface such as skin or wound when applied, and moisture such as exudate and sweat from the body can be quickly disposed of. By making the adhesiveness of the first region lower than that of the second region and making the adhesiveness of the second region higher, the foam of the embodiment of the present invention has a configuration that is difficult to peel off.

[0022] In the foam of the embodiment according to the present invention, the number of bubbles in the first region may be greater than the number of bubbles in the second region. In the case of open cells, the number of bubbles refers to the number of bubbles constituting the open cells, for example, the number of open cells consisting of two bubbles is two. When the number of bubbles in the first region is greater than the number of bubbles in the second region, the water absorption speed of the first region increases, and the foam of the embodiment according to the present invention can quickly absorb, for example, body fluids, while the water absorption speed and amount of the second region are further reduced, the intrusion of moisture from the outside (the peripheral or peripheral part of the foam) is suppressed, and the water resistance of the second region is improved, making the foam less likely to peel off, and the excess exudate absorbed in the first region can be prevented from spreading to the surrounding area, causing maceration of healthy skin.

[0023] In the foam according to the embodiment of the present invention, the first region may have a larger water absorption capacity per unit volume than the second region. Since the first region has a larger water absorption capacity per unit volume than the second region, the second region is resistant to water from the outside, is not easily peeled off (e.g., during bathing), is not easily absorbed, and is highly durable, while the first region is easily absorbed by exudates and the like, and skin maceration is not easily caused in the first region.

[0024] In the foam according to the embodiment of the present invention, the specific gravity of the first region may be smaller than that of the second region. The specific gravities of the first region and the second region can be adjusted by the difference in the number of cells and the cell structure. For example, by increasing the number or volume ratio of the open cell structure, the specific gravity of the first region can be made smaller than that of the second region, and the water absorption properties of the first region and the second region can be changed.

[0025] In the foam of the embodiment according to the present invention, the elastic modulus of the first region may be greater than that of the second region. Since the elastic modulus of the first region is greater than that of the second region, the first region can be pressed against a body surface (e.g., skin) more strongly than the second region. The foam of the embodiment according to the present invention exerts a hemostatic effect, a molding action, and a scar formation inhibitory effect by pressing against a wound or surgical wound, and in a stoma appliance, it can adhere more strongly to the body surface around the stoma and follows the unevenness of the skin around the stoma edge, making it difficult for excrement such as urine and feces to leak.

[0026] Hereinafter, the foam according to the embodiment of the present invention will be described in more detail with reference to Fig. 1 and Fig. 2. Fig. 1 and Fig. 2 are cross-sectional views showing examples of the configuration of the foam according to the embodiment of the present invention. Note that the foam according to the first embodiment of the present invention is not limited to the examples of the configuration of the foam according to the embodiment of the present invention shown in Fig. 1 and Fig. 2, within the scope not departing from the object and gist of the present invention.

[0027] First, a foam according to an embodiment of the present invention will be described with reference to Fig. 1. The foam 1 (1-1) shown in Fig. 1(a) comprises a first region 2 (2-1) and a second region 3 (3-1-1 and 3-1-2). The second regions 3-1-1 and 3-1-2 are disposed on the outer periphery of the first region 2-1. T-1-1 shown in Fig. 1(a) is the skin contact surface of the second region 3-1-1, T-2-1 is the skin contact surface of the first region 2-1, and T-3-1 is the skin contact surface of the second region 3-1-2.

[0028] As shown in Fig. 1(a), the thickness of the first region 2-1 (vertical direction in Fig. 1; the same applies below) is approximately equal to or greater than the thickness of the second region 3-1-1 and 3-1-2 (vertical direction in Fig. 1; the same applies below). The first region 2-1 is convex with respect to the second region 3-1-1 and 3-1-2, the thickness of the first region 2-1 is approximately constant, and the cross-sectional shape of the first region 2-1 is approximately rectangular. The thickness of the first region 2-1 does not have to be constant.

[0029] As shown in Figure 1(a), the thickness of the second regions 3-1-1 and 3-1-2 decreases as they move away from the first region, and the thicknesses of the second regions 3-1-1 and 3-1-2 converge at the tips of the second regions 3-1-1 and 3-1-2, and the cross-sectional shapes of the second regions 3-1-1 and 3-1-2 are approximately triangular.

[0030] The skin contact surface T-1-1 of the second region 3-1-1, the skin contact surface T-2-1 of the first region 2-1, and the skin contact surface T-3-1 of the second region 3-1-2 may be planar with a flat portion or curved.

[0031] FIG. 1(b) is an enlarged view of P-1, which is a part of the second region 3-1-1, P-2, which is a part of the first region 2-1, and the boundary L-1 between P-1 and P-2, which are shown in FIG. 1(a). As shown in FIG. 1(b), R-1 (enlarged view of P-1), which is a part of the second region 3-1-1, has closed bubbles i-1-b-1, and R-2 (enlarged view of P-2), which is a part of the first region 2-1, has open bubbles c-1-b-1. The boundary L-2 (L-1) between the first region 2-1 and the second region 3-1-1 is where the thickness change rate of the first region 2-1 and the thickness change rate of the second region 3-1-1 are different, or where the thickness of the first region 2-1 and the thickness of the second region 3-1-1 are approximately equal or different, and where the bubble structure changes.

[0032] FIG. 1(c) is an enlarged view of Q-1, which is a part of the first region 2-1, Q-2, which is a part of the second region 3-1-2, and the boundary M-1 between Q-1 and Q-2 shown in FIG. 1(a). As shown in FIG. 1(c), open bubbles c-1-c-1 exist in S-1 (enlarged view of Q-1), which is a part of the first region 2-1, and closed bubbles i-1-c-1 exist in S-2 (enlarged view of Q-2), which is a part of the third region 3-1-2. The boundary M-2 (M-1) between the first region 2-1 and the second region 3-1-2 is where the thickness change rate of the first region 2-1 and the thickness change rate of the second region 3-1-2 are different, or where the thickness of the first region 2-1 and the thickness of the second region 3-1-2 are approximately equal or different, and where the bubble structure changes.

[0033] The foam according to the embodiment of the present invention will be further described with reference to FIG.

[0034] The foam 1-2-a shown in Fig. 2(a) has a first region 2-2-a and second regions 3-2-a-1 and 3-2-a-2. The second regions 3-2-a-1 and 3-2-a-2 are arranged on the outer periphery of the first region 2-2-a. T-1-2-a shown in Fig. 2(a) is the skin contact surface of the second region 3-2-a-1, T-2-2-a is the skin contact surface of the second region 2-2-a, and T-3-2-a is the skin contact surface of the second region 3-2-a-2.

[0035] As shown in Fig. 2(a), the thickness of the first region 2-2-a (vertical direction in Fig. 2(a) hereinafter) is approximately equal to or greater than the thickness of the second region 3-2-a-1 and 3-2-a-2 (vertical direction in Fig. 2(a) hereinafter). The first region 2-2-a is convex with respect to the second region 3-2-a-1 and 3-2-a-2, the thickness of the first region 2-2-a decreases as it approaches the regions of the second region 3-2-a-1 and 3-2-a-2, and the cross-sectional shape of the first region 2-2-a is approximately semicircular.

[0036] As shown in FIG. 2(a), the second regions 3-2-a-1 and 3-2-a-2 have a substantially constant thickness and a substantially rectangular cross-sectional shape.

[0037] The skin contact surface T-1-2-a of the second region 3-2-a-1, the skin contact surface T-2-2-a of the first region 2-2-a, and the skin contact surface T-3-2-a of the second region 3-2-a-2 may be planar with a flat portion or curved.

[0038] The foam 1-2-b shown in Fig. 2(b) has a first region 2-2-b and second regions 3-2-b-1 and 3-2-b-2. The second regions 3-2-b-1 and 3-2-b-2 are arranged on the outer periphery of the first region 2-2-b. T-1-2-b shown in Fig. 2(b) is the skin contact surface of the second region 3-2-b-1, T-2-2-b is the skin contact surface of the second region 2-2-b, and T-3-2-b is the skin contact surface of the second region 3-2-b-2.

[0039] As shown in FIG. 2(b), the thickness of the first region 2-2-b (vertical direction in FIG. 2(b) hereinafter) is approximately equal to or greater than the thickness of the second region 3-2-b-1 and 3-2-b-2 (vertical direction in FIG. 2(b) hereinafter). The first region 2-2-b is convex with respect to the second region 3-2-b-1 and 3-2-b-2, and the thickness of the first region 2-2-b is approximately constant in the center of the first region, but becomes smaller as it approaches the regions of the second region 3-2-b-1 and 3-2-b-2, and the cross-sectional shape of the first region 2-2-b is tapered. Although not shown, the cross-sectional shape of the first region 2-2-b may be an inverse tapered shape.

[0040] As shown in FIG. 2(b), the second regions 3-2-b-1 and 3-2-b-2 have a substantially constant thickness and a substantially rectangular cross-sectional shape.

[0041] The skin contact surface T-1-2-b of the second region 3-2-b-1, the skin contact surface T-2-2-b of the first region 2-2-b, and the skin contact surface T-3-2-b of the second region 3-2-b-2 may be planar with a flat portion or curved.

[0042] The foam 1-2-c shown in Fig. 2(c) comprises a first region 2-2-c and second regions 3-2-c-1 and 3-2-c-2. The second regions 3-2-c-1 and 3-2-c-2 are arranged on the outer periphery of the first region 2-2-c. T-1-2-c shown in Fig. 2(c) is the skin contact surface of the second region 3-2-c-1, T-2-2-c is the skin contact surface of the second region 2-2-c, and T-3-2-c is the skin contact surface of the second region 3-2-c-2.

[0043] As shown in Fig. 2(c), the thickness of the first region 2-2-c (vertical direction in Fig. 2(c) hereinafter) is approximately equal to or greater than the thickness of the second region 3-2-c-1 and 3-2-c-2 (vertical direction in Fig. 2(c) hereinafter). The first region 2-2-c is convex with respect to the second region 3-2-c-1 and 3-2-c-2, and the thickness of the first region 2-2-c is maximum at approximately the center and decreases toward the second region 3-2-c-1 and 3-2-c-2, and the cross-sectional shape of the first region 2-2-c is approximately rectangular.

[0044] As shown in FIG. 2(c), the thickness of the second regions 3-2-c-1 and 3-2-c-2 decreases with increasing distance from the first region, and the thickness of the second regions 3-2-c-1 and 3-2-c-2 converges at the tips of the second regions 3-2-c-1 and 3-2-c-2, so that the cross-sectional shapes of the second regions 3-2-c-1 and 3-2-c-2 are approximately triangular.

[0045] The skin contact surface T-1-2-c of the second region 3-2-c-1, the skin contact surface T-2-2-c of the first region 2-2-c, and the skin contact surface T-3-2-c of the second region 3-2-c-2 may be planar with a flat portion or curved.

[0046] The cell structure of the foam according to the embodiment of the present invention will be described in detail with reference to FIGS.

[0047] First, the cell structure of the foam according to the embodiment of the present invention will be described with reference to Fig. 5. Fig. 5(a) is a schematic diagram showing a first example of a first cell structure of the first region of the foam according to the embodiment of the present invention. Fig. 5(b) is a schematic diagram showing a first example of a second cell structure of the second region of the foam according to the embodiment of the present invention.

[0048] As shown in Fig. 5(a), the first cell structure has a first open cell structure consisting of open cells c-5-a-1 to c-5-a-4. As shown in Fig. 5(b), the second cell structure has a second closed cell structure consisting of closed cells i-5-b-1 to i-5-b-4, and further has a second open cell structure consisting of open cell c-5-b-1.

[0049] As shown in Fig. 5, the ratio of the first open cell structure to the first cell structure is greater than the ratio of the second open cell structure to the second cell structure. This ratio may be the ratio of the number of bubbles or the ratio of the volume of the bubbles. Also, as shown in Fig. 5, the ratio of the first closed cell structure-1 to the first cell structure (Fig. 5a) is smaller than the ratio of the second closed cell structure to the second cell structure. This ratio may be the ratio of the number of bubbles or the ratio of the volume of the bubbles.

[0050] Next, the cell structure of the foam according to the embodiment of the present invention will be described with reference to Fig. 6. Fig. 6(a) is a schematic diagram showing a second example of the first cell structure of the first region of the foam according to the embodiment of the present invention. Fig. 6(b) is a schematic diagram showing a second example of the second cell structure of the second region of the foam according to the embodiment of the present invention.

[0051] As shown in Fig. 6(a), the first cell structure has a first open cell structure composed of open cells c-6-a-1 to c-6-a-5, and further has a first closed cell structure composed of closed cells i-6-a-1 to i-6-a-3. As shown in Fig. 6(b), the second cell structure has a second closed cell structure composed of closed cells i-6-b-1 to i-6-b-5, and further has a second open cell structure composed of open cells c-6-b-1.

[0052] As shown in Fig. 6, the ratio of the first open cell structure to the first cell structure is greater than the ratio of the second open cell structure to the second cell structure. This ratio may be the ratio of the number of bubbles or the ratio of the volume of bubbles. Also, as shown in Fig. 6, the ratio of the first closed cell structure to the first cell structure is smaller than the ratio of the second closed cell structure to the second cell structure. This ratio may be the ratio of the number of bubbles or the ratio of the volume of bubbles.

[0053] The foam according to the embodiment of the present invention may be used as a component of a wound dressing. By using the foam according to the embodiment of the present invention as a wound dressing or a component of a wound dressing, the following effects are expected. - It can compress and fix the wound, which helps stop bleeding. - Compression and fixation of the surgical site prevents the occurrence of hypertrophic scars. The second area has a lower water absorption capacity than the first area, so it is not affected by external moisture, such as when bathing.

[0054] Hereinafter, a wound dressing comprising a foam according to an embodiment of the present invention will be described with reference to Fig. 3. Fig. 3(a) is a top view showing an example of the configuration of a wound dressing comprising a foam according to an embodiment of the present invention. Fig. 3(b) is a cross-sectional view showing an example of the configuration of a wound dressing comprising a foam according to an embodiment of the present invention. Note that the wound dressing comprising a foam according to an embodiment of the present invention is not limited to the example of the configuration of the wound dressing comprising a foam according to an embodiment of the present invention shown in Fig. 3, within the scope of the object and spirit of the present invention.

[0055] As shown in FIG. 3(a), the wound dressing 4-3-a includes a substrate 5-3-a on the top of the wound dressing 4-3-a.

[0056] Next, refer to FIG. 3(b). The wound dressing 4-3-b is formed by laminating a release film 6-3-b, a foam 1-3-b, and a base material 5-3-b in this order. The foam 1-3-b has a first region 2-3-b and second regions 3-3-b-1 and 3-3-b-2. The second regions 3-3-b-1 and 3-3-b-2 are disposed on the outer periphery of the first region 2-3-b. The release film 6-3-b side is the skin contact surface side.

[0057] Except for the above description, the contents of Figs. 1 to 2 and Figs. 5 to 6 can be directly applied to the foam of the embodiment according to the present invention used for a wound dressing.

[0058] The foam according to the embodiment of the present invention may also be used as a skin protective agent as a part of the face plate of an excrement storage appliance (sometimes called an ostomy appliance). Examples of excrement storage appliances (ostomy appliances) include artificial anus appliances, artificial bladder appliances, ileostomy appliances, etc. By using the foam according to the embodiment of the present invention as a part of the face plate of an excrement storage appliance (ostomy appliance), the following effects are achieved. As a face plate for ostomy appliances, it adheres closely to the skin around the stoma and prevents leakage. It is especially suitable for inverted stomas and uneven skin. Even if it is applied for a long time, it can quickly absorb moisture from sweat and excrement, preventing maceration and peeling of the skin.

[0059] Hereinafter, an excrement collection appliance (ostomy appliance) including a foam according to an embodiment of the present invention will be described with reference to Fig. 4. Fig. 4(a) is a top view showing an example of the configuration of an excrement collection appliance including a foam according to an embodiment of the present invention. Fig. 4(b) is a cross-sectional view showing an example of the configuration of an excrement collection appliance including a foam according to an embodiment of the present invention. Note that the excrement collection appliance including a foam according to an embodiment of the present invention is not limited to the example of the configuration of the excrement collection appliance including a foam according to an embodiment of the present invention shown in Fig. 4, within the scope of the object and spirit of the present invention.

[0060] Fig. 4(a) shows the excrement collection appliance 7-4-a. As shown in Fig. 4(a), the pouch 9-4-a included in the excrement collection appliance 7-4-a is formed into a sealed bag shape using a plastic film, and a base plate 8-4-a is provided on the top. The base plate 8-4-a is attached to the patient's artificial opening (stoma), and excrement is discharged into the pouch 9-4-a through the opening 10-4-a of the base plate 8-4-a.

[0061] Next, refer to Fig. 4(b). In the excrement collection device 7-4-b, a face plate 8-4-b is disposed on a pouch 9-4-b, and the face plate 8-4-b has an opening 10-4-b. From the pouch 9-4-b side, base materials 5-4-b-1 and 5-4-b-2, foams 1-4-b-1 and 1-4-b-2, and release films 6-4-b-1 and 6-4-b-2 are laminated in this order. The foam 1-4-b-1 has a first region 2-4-b-1 and a second region 2-4-b-1. The foam 1-4-b-2 has a first region 2-4-b-2 and a second region 2-4-b-2. The second regions 2-4-b-1 and 2-4-b-2 are disposed around the outer periphery of the first regions 2-4-b-1 and 2-4-b-2. The release films 6-4-b-1 and 6-4-b-2 are on the skin contact side.

[0062] Other than as described above, the contents of Figs. 1 to 2 and Figs. 5 to 6 can be directly applied to the foam of the embodiment according to the present invention used in the excrement collection device.

[0063] The materials used in the production of the foam according to the present invention will now be described.

[0064] (Urethane) The foam according to the present invention includes a urethane resin prepared by foaming a mixture of at least one polyol, a compound containing at least one isocyanate group, and a hydrophilic polymer. For efficient foaming, it is preferable to include a foaming agent. In the present invention, as described below, it is preferable to react at least one polyol with a compound containing at least one isocyanate group in the presence of a hydrophilic polymer containing a foaming agent to foam the mixture. It is preferable to use a solvent-free material for at least one polyol and a compound containing at least one isocyanate group, since this makes it possible to prepare a homogeneous foam. In the foam according to the present invention, in relation to the OH equivalent of the polyol and the NCO equivalent of the compound containing at least one isocyanate group, the NCO / OH ratio may be any value, but is preferably 0.5 or more and 1.0 or less. The OH equivalent of the polyol is preferably 1000 or more, and the NCO equivalent of the polyisocyanate is preferably 100 or more.

[0065] (Polyol) The foam of the present invention can be produced using a polyol for producing polyurethane foam. The polyol is not particularly limited, and a commercially available one can be used. From the viewpoint of increasing safety when the foam material of the present invention is applied to the human body, it is preferable to use a polyol for medical products.

[0066] The blending amount of the polyol is preferably 25 to 80 mass %, more preferably 50 to 70 mass %, based on the total mass of the mixture of materials before foaming.

[0067] Examples of polyols include polyether polyols, polyester polyols, and polycarbonate polyols. Examples of polyether polyols include polypropylene ether glycol and polytetramethylene glycol. Examples of polyester polyols include polybutylene adipate and polycaprolactone glycol. Examples of polycarbonate polyols include 1,6-hexane polycarbonate diol. Usually, these compounds are used alone, but two or more of them may be used in combination.

[0068] (Compound containing at least one isocyanate group) The foam of the present invention can be produced using a compound containing at least one isocyanate group for producing polyurethane foam (hereinafter, sometimes abbreviated to isocyanate). The isocyanate is not particularly limited, and commercially available isocyanates can be used. From the viewpoint of increasing safety when the foam material of the present invention is applied to the human body, it is preferable to use an isocyanate for medical products.

[0069] Generally, isocyanates for producing urethane foams are classified into aromatic, alicyclic, and aliphatic types. Any of these may be used as long as it can provide an appropriate expansion ratio and exhibit appropriate properties as a foam material. The isocyanate may be a compound having multiple isocyanate groups in one molecule. The isocyanate may be a prepolymer in which a monomer having multiple isocyanate groups is polymerized in advance.

[0070] Examples of compounds containing at least one isocyanate group include aromatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, m- and p-phenylene diisocyanate, and 2,4- and 2,6-tolylene diisocyanate, alicyclic diisocyanates such as isophorone diisocyanate, 4-4'-dicyclohexylmethane diisocyanate, and 1,4-cyclohexylene diisocyanate, and aliphatic diisocyanates such as hexamethylene diisocyanate. Usually, these compounds are used alone, but two or more of them may be used in combination.

[0071] Specific examples of aliphatic polyisocyanates that can be used include hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), butene diisocyanate (BDI), 1,3-butadiene-1,4-diisocyanate, octamethylene diisocyanate, and modified products thereof. Specific examples of alicyclic polyisocyanates that can be used include isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate [hydrogenated diphenylmethane diisocyanate (hydrogenated MDI)], hydrogenated xylene diisocyanate (hydrogenated XDI), cyclohexane diisocyanate, methylcyclohexane diisocyanate, and dicyclohexylmethane diisocyanate.

[0072] As the polyisocyanates, in addition to the above-mentioned aliphatic or alicyclic polyisocyanates, trifunctional or higher polyisocyanates such as lysine ester triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, and bicycloheptane triisocyanate can also be used. Among these polyisocyanates, lysine ester triisocyanate and 1,3,6-hexamethylene triisocyanate are preferred. These polyisocyanates can be used together with the above-mentioned diisocyanate, and the blending amount thereof is preferably 60 mass% or less in the polyisocyanates.

[0073] A preferred isocyanate for producing the foam according to the present invention is a polyisocyanate prepolymer in which an aliphatic isocyanate monomer has been polymerized in advance, and which has an isocyanate group at its terminal.

[0074] The amount of isocyanate blended is preferably 5 to 30% by mass, and more preferably 8 to 30% by mass, based on the total mass of the mixture of materials before foaming.

[0075] (foaming agent) In producing the foam according to the present invention, a foaming agent is used to properly foam the material. As the foaming agent, water or an organic solvent can be used.

[0076] When water is used as a blowing agent, it is preferable to mix the water with polyol and isocyanate in a state where the water is absorbed in a hydrophilic polymer described later. In this case, the water naturally contained in the hydrophilic polymer can be utilized. By heating the mixture, a foam suitable for the foam of the present invention can be produced in which a porous and hydrophilic polymer is dispersed. When polyol and isocyanate are reacted and crosslinked, if water is used as a blowing agent, the isocyanate and water react, and no crosslinking reaction occurs. However, the present invention makes it possible to produce a foam using water while proceeding with the crosslinking reaction by retaining water in the hydrophilic component.

[0077] The organic solvent is preferably one which does not remain after foaming, and examples of the organic solvent that can be used include ethanol, ethyl acetate, hexane, pentane, acetone, and dichloromethane.

[0078] (hydrophilic polymer) One of the features of the foam of the present invention is that it contains a hydrophilic polymer. When the foam contains a hydrophilic polymer, the exudate absorbed when the foam is applied to the wound surface is absorbed by the hydrophilic polymer. This makes it possible to prevent the exudate from returning to the wound surface even if the foam is compressed or stretched after absorbing water when applied to the wound surface.

[0079] In the foam of the embodiment according to the present invention, the amount of hydrophilic polymer contained per unit volume in the first region is preferably greater than the amount of hydrophilic polymer contained per unit volume in the second region.

[0080] For example, when a powder or fibrous hydrophilic polymer is used as the hydrophilic polymer, the foam of the present invention will turn into a sol on the wound surface of the foam material when it absorbs moisture such as exudate. The sol is said to not only physically protect the wound surface but also to be useful in reducing pain.

[0081] The blending amount of the hydrophilic polymer is preferably 5 to 50 mass %, more preferably 10 to 30 mass %, based on the total mass of the material mixture before foaming.

[0082] The water content of the hydrophilic polymer may be any amount, but is preferably 10% by mass or more from the viewpoint of the expansion ratio. This preferred embodiment allows the foam of the present invention to have a predetermined adhesiveness. The hydrophilic polymer may be swellable and water-soluble, swellable and water-insoluble, non-swellable and water-soluble, or non-swellable and water-insoluble. The foam of the present invention preferably contains at least one water-soluble hydrophilic polymer. The foam of the present invention more preferably contains at least two hydrophilic polymers, at least one of which is a water-soluble hydrophilic polymer, and at least one of which is a swellable hydrophilic polymer. In this way, by containing a water-soluble hydrophilic polymer and a swellable hydrophilic polymer, the hydrophilic polymer forms a sol-like substance on the foam surface, and the swellable polymer can hold water, so that the foam can be formed by volatilization of water during heating while suppressing the crosslinking inhibition of isocyanate by water in the foam manufacturing process. As the hydrophilic polymer of the present invention, one that becomes a sol after absorbing water is preferred, and one that becomes a sol after absorbing water in the foam and flows out of the foam is preferred.

[0083] The hydrophilic polymer is not particularly limited, and may be a natural, semi-synthetic or synthetic hydrophilic polymer. Note that "semi-synthetic" is also called partial chemical synthesis, and refers to chemical synthesis using compounds isolated from natural sources such as plant materials, microorganisms or cell cultures as starting materials.

[0084] Specific examples of natural hydrophilic polymers include plant-based polymers such as gum arabic, gum tragacanth, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, and starch (e.g., rice, corn, potato, and wheat starch), microbial polymers such as xanthan gum, dextrin, dextran, succinoglucan, mannan, locust bean gum, and pullulan, and animal polymers such as casein, albumin, and gelatin. Citrus pectin is preferred as the pectin.

[0085] Specific examples of semi-synthetic hydrophilic polymers include starch-based polymers (e.g., carboxymethyl starch, methylhydroxypropyl starch, etc.); cellulose-based polymers (e.g., methyl cellulose, ethyl cellulose, methylhydroxypropyl cellulose, hydroxyethyl cellulose, sodium cellulose sulfate, hydroxypropyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, etc.); alginic acid-based polymers (e.g., sodium alginate, calcium alginate, propylene glycol alginate, etc.).

[0086] Specific examples of synthetic hydrophilic polymers include vinyl polymers (eg, polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, carboxyvinyl polymers, etc.); acrylic polymers (eg, sodium polyacrylate, polyacrylamide, etc.); polyethyleneimine, etc.

[0087] The above hydrophilic polymers may be used alone or in combination of two or more. Of the above hydrophilic polymers, it is preferable to use one or more selected from sodium carboxymethylcellulose, pectin, karaya gum, mannan, guar gum, locust bean gum, and gelatin. When an alginic acid-based polymer is used among the above hydrophilic polymers, the foam of the present invention may exert a hemostatic effect on the wound surface.

[0088] (catalyst) In order to efficiently react the polyol and isocyanate according to the present invention, it is preferable to use a catalyst. The catalyst may be any catalyst that is used in polyurethane foams, and examples of the catalyst that can be used include amine catalysts such as triethylamine, triethylenediamine, diethanolamine, dimethylaminomorpholine, N-ethylmorpholine, and tetramethylguanidine, tin catalysts such as stannous octoate and dibutyltin dilaurate, and metal catalysts such as phenylmercury propionate, lead octenate, and zinc carbonate.

[0089] (others) The foam according to the present invention may contain other components to be mixed with the hydrophilic polymer. For example, a silver compound may be contained in order to impart antibacterial properties. In order to improve water absorption, a sphingolipid such as ceramide, hyaluronic acid, astaxanthin, or other physiologically active substance may be contained. In addition, a compound exhibiting a buffering action such as anhydrous sodium citrate may be contained as a pH adjuster. The foam according to the present invention may contain a surfactant, but it is preferable that it does not contain a surfactant. This is because the foam according to the present invention absorbs water even without containing a surfactant. In addition, by not containing a surfactant, the foam according to the present invention can further reduce skin irritation.

[0090] When the foam according to the present invention absorbs moisture such as exudate, the surface of the foam becomes sol-like because the hydrophilic polymer contained in the foam absorbs the moisture and becomes sol-like.

[0091] (base material) The foam according to the present invention may contain a substrate, which may be a commercially available resin film.

[0092] Examples of the resin film include those selected from polyurethane, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, polyolefins such as polypropylene, polyethylene, low-density polyethylene, high-density polyethylene, and polypropylene, olefin copolymers such as ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-methacrylic acid polymer (EMAA), and ethylene-acrylic acid copolymer (EAA), polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, and silicone. These may be used alone or in combination.

[0093] (Method of manufacturing foam) A method for producing a foam according to an embodiment of the present invention will be described.

[0094] First, a mold is prepared. Then, at least a polyol, an isocyanate, a hydrophilic polymer, a catalyst, etc. are placed in the mold, mixed, and heated to produce the foam of the embodiment according to the present invention. EXAMPLES

[0095] The foam according to the present invention will be described in more detail below with reference to examples. Note that the examples described below are representative examples of the foam according to the present invention. The scope of the foam according to the present invention should not be interpreted narrowly by these examples.

[0096] <Example 1> 37.8 g of polyol, 5.4 g of polyisocyanate, 31.8 g of zinc-based catalyst, and 15.0 g of sodium carboxymethylcellulose were mixed, placed in a mold, and heated at 110° C. for 30 minutes to produce Foam 1.

[0097] <Example 2> 25.2 g of polyol, 3.6 g of polyisocyanate, 1.2 g of zinc-based catalyst, and 10.0 g of sodium carboxymethylcellulose were mixed, placed in a mold, and heated at 90° C. for 60 minutes to prepare Foam 2.

[0098] [Evaluation method and results] (Observation of video microscope photographs) The cell structures of the foam 1 produced in Example 1 and the foam 2 produced in Example 2 were observed under a video microscope. The results of the observation under the video microscope are shown in FIG. 7. FIG. 7(a) is a video microscope photograph of the first cell structure-1 in the first region-1 of the foam 1. FIG. 7(b) is a video microscope photograph of the second cell structure-1 in the second region-1 of the foam 1. FIG. 8(a) is a video microscope photograph of the first cell structure-2 in the first region-2 of the foam 2. FIG. 8(b) is a video microscope photograph of the second cell structure-2 in the second region-2 of the foam 2.

[0099] First, FIG. 7 will be described. As shown in FIG. 7(a), the first cell structure-1 has a first open cell structure-1 composed of, for example, open cells 1 to 3. As shown in FIG. 7(a), the first open cell structure-1 also has open cells other than the open cells 1 to 3. As shown in FIG. 7(b), the second cell structure-1 has a second closed cell structure-1 composed of, for example, closed cells 1 to 3, and further has a second open cell structure-1 composed of, for example, open cell 4. As shown in FIG. 7(b), the second closed cell structure-1 also has closed cells other than the closed cells 1 to 3, and the second open cell structure-1 also has open cells other than the open cell 4.

[0100] As shown in Fig. 7, it can be seen that the ratio of the first open cell structure-1 to the first cell structure-1 is greater than the ratio of the second open cell structure-1 to the second cell structure-1 (ratio of the number of bubbles in Fig. 7). Also, as shown in Fig. 7, it can be seen that the ratio of the first closed cell structure-1 to the first cell structure-1 (no closed cell structure is observed in Fig. 7(a)) is smaller than the ratio of the second closed cell structure-1 to the second cell structure-1 (ratio of the number of bubbles in Fig. 7).

[0101] Next, FIG. 8 will be described. As shown in FIG. 8(a), the first cell structure-2 has a first open cell structure-2 composed of, for example, open cells 5 to 7, and further has a first closed cell structure-2 composed of, for example, closed cells 3. As shown in FIG. 8(a), the first open cell structure-2 also has open cells other than the open cells 5 to 7, and the first closed cell structure-2 also has open cells other than the closed cell 3. As shown in FIG. 8(b), the second cell structure-2 has a second closed cell structure-2 composed of, for example, closed cells 4 to 6, and further has a second open cell structure-2 composed of, for example, open cells 8. As shown in FIG. 8(b), the second closed cell structure-2 also has open cells other than the closed cells 4 to 6, and the second open cell structure-2 also has open cells other than the open cell 8.

[0102] As shown in Fig. 8, it can be seen that the ratio of the first open cell structure-2 to the first cell structure-2 is greater than the ratio of the second open cell structure-2 to the second cell structure-2 (ratio of the number of bubbles in Fig. 8). Also, as shown in Fig. 8, it can be seen that the ratio of the first closed cell structure-2 to the first cell structure-2 is smaller than the ratio of the second closed cell structure-2 to the second cell structure-2 (ratio of the number of bubbles in Fig. 8).

[0103] (Measurement of water absorption) From each of the foams, foam 1 produced in Example 1 and foam 2 produced in Example 2, cylindrical test pieces with a thickness of 0.3 to 1.4 mm and a diameter of 30 mm were produced, and the thickness (height of the cylinder) and weight of each of the first and second regions of foam 1 produced in Example 1 and foam 2 produced in Example 2 were measured (the weights are referred to as test piece weight 1 before water absorption). The circular surface of the test piece is approximately flat. The test piece was immersed in physiological saline at 37°C. After a certain period of time (1 hr, 24 hr, 48 hr), the test piece was taken out, the moisture attached to the test piece was wiped off, and the weight was measured (the weights are referred to as test piece weight 1 after water absorption). The amount of water absorption was calculated by the following formula (1). π is the ratio of the circumference of the circumference of the circle. The measurement results of the amount of water absorption of each of foams, foam 1 and foam 2, are shown in Table 1 below.

number

[0104] (Measurement of foam thickness) The thicknesses of the first and second regions of Foam 1 produced in Example 1 and the first and second regions of Foam 2 produced in Example 2 were measured with a thickness gauge. The measurement results of the thicknesses of Foam 1 and Foam 2 are shown in Table 1 below.

[0105] (Adhesive strength measurement) The adhesive strength of each of the first and second regions of Foam 1 produced in Example 1 and the first and second regions of Foam 2 produced in Example 2 was measured using a TACKINESS TESTER (manufactured by RHESCA). The conditions were 23°C, impression speed: 30mm / min, press time: 20sec, test speed: 600mm / min, and preload: 10gf. The measurement results of the adhesive strength of each of Foam 1 and Foam 2 are shown in Table 1 below.

[0106] (Measurement of apparent specific gravity) The apparent specific gravity of each of the first and second regions of Foam 1 produced in Example 1 and the first and second regions of Foam 2 produced in Example 2 was calculated from the weight and thickness (measured with a thickness gauge) of a 30 mmφ sample. The measurement results of the apparent specific gravity of each of Foam 1 and Foam 2 are shown in Table 1 below.

[0107] (Measurement of viscoelasticity) The viscoelasticity of each of the first and second regions of Foam 1 produced in Example 1 and the first and second regions of Foam 2 produced in Example 2 was measured using a rheometer (manufactured by Anton Paar), and the results of the complex shear modulus were compared. The measurement results of the complex shear modulus of each of Foam 1 and Foam 2 are shown in FIG. 9 below. The graph in FIG. 9 shows the results of the complex modulus at 0.1 Hz, 1 Hz, 10 Hz, and 100 Hz for each of the first and second regions of Foam 1 and the first and second regions of Foam 2. The vertical axis in FIG. 9 indicates the complex modulus value (Pa).

[0108] (Consideration) In Foam 1 and Foam 2, the first region had a lower specific gravity than the second region, but had higher viscoelasticity, lower adhesive strength, and faster absorption speed. This means that the first region has a high moisture processing ability for exudates and the like, allowing for appropriate compression to be applied. On the other hand, the second region absorbs less moisture from the outside and has adhesive strength, making it highly durable against sweat and exudates. Furthermore, it is flexible, causing less physical irritation to the skin. It is considered to be ideal for applications where absorbency is required in the center (first region) and fixing strength is required around the periphery (second region).

[0109] [Table 1]

[0110] The present invention can also have the following configurations. [1] A first region and a second region are provided, The second area is disposed around the first area, The first region has a first cell structure, and the second region has a second cell structure, A foam, wherein the first cell structure and the second cell structure are different structures from each other. [2] The foam according to [1], wherein the first region is thicker than the second region. [3] The foam according to [1] or [2], wherein the first cell structure has an open cell structure and the second cell structure has a closed cell structure. [4] the first cell structure has a first open cell structure; the second cell structure has a second open cell structure; The foam according to any one of [1] to [3], wherein a ratio of the first open-cell structure to the first cell structure is greater than a ratio of the second open-cell structure to the second cell structure. [5] the first cell structure has a first closed cell structure; the second cell structure has a second closed cell structure; The foam according to any one of [1] to [4], wherein a ratio of the first closed cell structure to the first cell structure is smaller than a ratio of the second closed cell structure to the second cell structure. [6] The foam described in any one of [1] to [5], wherein the first region and / or the second region has adhesiveness. [7] The foam according to any one of [1] to [6], wherein the number of bubbles in the first region is greater than the number of bubbles in the second region. [8] The foam described in any one of [1] to [7], wherein the first region has a larger water absorption amount per unit volume than the second region has a larger water absorption amount per unit volume. [9] The foam according to any one of [1] to [8], wherein the specific gravity of the first region is smaller than the specific gravity of the second region.

[10] The foam according to any one of [1] to [9], wherein the elastic modulus of the first region is greater than the elastic modulus of the second region.

[11] The foam described in any one of [1] to

[10] , wherein the first region is arranged in approximately the center of the foam, and the second region is arranged in the peripheral portion of the foam.

[12] At least one hydrophilic polymer is included, The foam according to any one of [1] to

[11] , wherein the amount of the hydrophilic polymer contained per unit volume in the first region is greater than the amount of the hydrophilic polymer contained per unit volume in the second region. [Explanation of symbols]

[0111] 1(1-1, 1-2-a, 1-2-b, 1-2-c, 1-3-b, 1-4-b-1, 1-4-b-2) ··· Foam, 2 (2-1, 2-2-a, 2-2-b, 2-2-c, 2-3-b, 2-4-b-1, 2-4-b-2)...first area part, 3(3-1-1, 3-1-2, 3-2-a-1, 3-2-a-2, 3-2-b-1, 3-2-b-2, 3-2-c-1, 3-2-c-2, 3-3-b-1, 3-3-b-2, 3-4-b-1, 3-4-b-2)...Second area part, 4-3-a, 4-3-b...Wound dressing, 7-4-a, 7-4-b: Excrement collection equipment, T(T-1-1, T-2-1, T-3-1, T-1-2-a, T-2-2-a, T-3-2-a, T-1-2-b, T-2-2-b, T-3-2-b, T-1-2-c, T-2-2-c, T-3-2-c)...Skin contact surface,

Claims

1. A first region and a second region are provided, The second region is disposed around the outer periphery of the first region, The first region has a first cell structure, and the second region has a second cell structure, the first region and the second region contain the same resin, the first cell structure and the second cell structure are different structures from each other, a portion of the first region made of the same resin as that of the second region constitutes the first air bubble structure; the first cell structure has an open cell structure, and a proportion of the open cell structure in the first cell structure is greater than a proportion of the open cell structure in the second cell structure; The foam, wherein the same resin is a urethane resin prepared by foaming a mixture of at least one polyol, at least one compound containing an isocyanate group, and a hydrophilic polymer.

2. 2. The foam according to claim 1, wherein the ratio of the open cell structure in the cell structure is the number of the open cells relative to the total number of the closed cells and the open cells in the cell structure.

3. 2. The foam according to claim 1, wherein the ratio of the open cell structure in the cell structure is the volume of the open cells relative to the total volume of the closed cells and the open cells in the cell structure.

4. The foam according to claim 1 , wherein the first region has a thickness greater than a thickness of the second region.

5. 5. The foam according to claim 1, wherein the first cell structure has an open cell structure and the second cell structure has a closed cell structure.

6. the first cell structure has a first open cell structure; the second cell structure has a second open cell structure; 6. The foam according to claim 1, wherein a ratio of the first open-cell structure to the first cell structure is greater than a ratio of the second open-cell structure to the second cell structure.

7. the first cell structure has a first closed cell structure; the second cell structure has a second closed cell structure; 7. The foam according to claim 1, wherein a ratio of the first closed cell structure to the first cell structure is smaller than a ratio of the second closed cell structure to the second cell structure.

8. The foam according to claim 1 , wherein the first region and / or the second region has adhesiveness.

9. The foam according to claim 1 , wherein the number of cells in the first region is greater than the number of cells in the second region.

10. The foam according to claim 1 , wherein the first region has a larger water absorption amount per unit volume than the second region has a larger water absorption amount per unit volume.

11. The foam according to claim 1 , wherein the specific gravity of the first region is smaller than the specific gravity of the second region.

12. The foam of claim 1 , wherein the first region has a greater elastic modulus than the second region.

13. The foam according to claim 1 , wherein the first region is disposed at a substantially central portion of the foam, and the second region is disposed at a peripheral portion of the foam.

14. At least one hydrophilic polymer is included, 14. The foam according to claim 1, wherein the amount of the hydrophilic polymer contained per unit volume in the first region is greater than the amount of the hydrophilic polymer contained per unit volume in the second region.

15. A waste containment device comprising a foam according to any one of claims 1 to 14.

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