Material for sanitary product

Abstract

To provide a materiel for sanitary product that enables manufacturing of a sanity item that has sufficient strength and prevents a user from feeling an unpleasant sticky touch.SOLUTION: A material for sanitary product includes a first sheet and a second sheet, the first sheet and the second sheet being stacked, the first sheet being formed of cellulose based fiber, the second sheet being formed of spunbond nonwoven fiber. It is preferable that the first sheet is formed of cotton fiber or rayon fiber. It is preferable that the spunbond nonwoven fiber forming the second sheet is sheath-core bicomponent fiber having a fiber structure where polyethylene terephthalate is disposed in a core part and polyethylene is disposed in a sheath part.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a material for sanitary materials, for example, a material for sanitary materials such as diapers, napkins, and incontinence pads. [Background technology]

[0002] As this type of sanitary material, nonwoven sheets made only of hydrophobic synthetic fibers made of polypropylene are often used. However, since they are made only of hydrophobic synthetic fibers, they are easy to permeate when they come into contact with a large amount of body fluid at once, but are difficult to permeate when they come into contact with a small amount of body fluid, and are difficult to absorb from the surface of the nonwoven sheet. To solve this problem, for example, Patent Document 1 discloses a surface layer made of hydrophobic synthetic fibers, in which an aggregate of hydrophilic fibers such as cotton is dispersed and contained in a clump or crimped state inside. With such a sanitary material, a large amount of liquid quickly permeates the hydrophobic synthetic fibers, and a small amount of liquid is retained in the aggregate of hydrophilic fibers. This makes it easier to keep the surface of the surface layer dry.

[0003] Also, as a publicly known material for hygienic materials, those formed from cotton sheets are widely known. Cotton sheets have good liquid absorption properties and are excellent at absorbing liquids discharged from the human body, and because they are made of natural materials, they are preferred as materials that come into direct contact with the skin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-651 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, cotton sheets are not strong enough to be used as sanitary products, and when the cotton sheets absorb liquid and come into direct contact with the skin of the user as sanitary products, they give the user an unpleasant sticky feeling.

[0006] It is therefore an object of the present invention to obtain a material for sanitary materials that can be manufactured into sanitary materials that have sufficient strength and do not give an unpleasant sticky feeling to users. [Means for solving the problem]

[0007] To achieve this objective, the hygienic material of the present invention is characterized by a laminate of a first sheet made of cellulosic fibers and a second sheet on the skin side made of spunbond nonwoven fabric.

[0008] According to the hygienic material of the present invention, it is preferable that the first sheet is formed from cotton fibers or rayon fibers.

[0009] According to the hygienic material of the present invention, it is preferable that the fineness of the constituent fibers of the second sheet is 3 to 15 dtex.

[0010] According to the sanitary material of the present invention, it is preferable that the second sheet is formed from a spunbond nonwoven fabric whose constituent fibers are core-sheath type composite fibers in which polyethylene terephthalate is arranged in the core and polyethylene is arranged in the sheath.

[0011] According to the hygienic material of the present invention, the basis weight of the first sheet is 7 to 23 g / m 2 It is preferable that:

[0012] According to the hygienic material of the present invention, the basis weight of the second sheet is 8 to 23 g / m 2 It is preferable that: Effect of the Invention

[0013] According to the sanitary material of the present invention, since the first sheet made of cellulosic fibers and the second sheet on the skin side made of spunbonded nonwoven fabric are laminated, the strength of the sanitary material can be provided by the second sheet on the skin side made of spunbonded nonwoven fabric, and therefore the strength can be improved compared to a sanitary material composed only of a cotton sheet. In addition, in the sanitary material of the present invention, liquids such as body fluids pass through the second sheet made of spunbonded nonwoven fabric on the skin side and can be quickly absorbed by the first sheet made of cellulosic fibers with excellent liquid absorption laminated underneath, so that the sanitary material has excellent liquid absorption compared to a sanitary material composed only of a sheet made of hydrophobic fibers such as spunbonded nonwoven fabric. Moreover, since the second sheet made of spunbonded nonwoven fabric is the skin side that directly contacts the skin, the first sheet made of cellulosic fibers with liquid absorption does not come against the skin of the user, which has the advantage of not giving the user an unpleasant sticky feeling. Furthermore, since the second sheet made of spunbond nonwoven fabric is placed on the skin side, it is possible to effectively prevent liquid from flowing back from the first sheet made of absorbent cellulosic fibers onto the user's skin. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a diagram showing a method for measuring liquid absorbency. [Diagram 2] FIG. 2 is a diagram showing a method for measuring the liquid backflow prevention property. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The hygiene material of the present invention is configured by laminating a first sheet formed from cellulosic fibers and a second sheet facing the skin, formed from a spunbond nonwoven fabric, forming the top sheet of the hygiene material.

[0016] Examples of the cellulosic fibers constituting the first sheet include absorbent fibers such as cotton fibers, rayon fibers, etc. The first sheet is formed into a sheet shape by superposing a web containing these fibers on a second sheet and subjecting it to a hydroentanglement treatment, and then integrating the first sheet with the second sheet.

[0017] Cotton fibers have a higher degree of polymerization of cellulose and a higher degree of crystallinity than rayon fibers. Therefore, water molecules once captured in the narrow amorphous space between microfibrils tend not to be released again. In addition, the cross section of cotton fibers has a hollow part called a lumen. Therefore, generally speaking, cotton fibers have a higher liquid retention than rayon fibers. Therefore, sanitary materials such as diapers and incontinence pads generally have a three-layer structure consisting of a sanitary material that is a surface layer, an absorbent material that absorbs and retains liquid in the layer below, and a leak-proof layer that prevents liquid leakage in the layer below. However, when rayon fibers are selected rather than cotton fibers for the first sheet in the sanitary material of the present invention, the first sheet releases the liquid absorbed by the first sheet itself without retaining it, and the released liquid can be transferred well to the absorbent material present in the layer below, thereby improving the prevention of liquid returning to the surface side.

[0018] The basis weight of the first sheet is 7 to 23 g / m 2 The hygienic material of the present invention is capable of effectively absorbing fluids discharged from the human body by forming a sheet having such a basis weight from cellulosic fibers into an appropriate size in the surface direction.

[0019] The first sheet is made of cellulosic fibers such as cotton and rayon, and the fiber fineness is preferably about 1.0 to 2.5 dtex, and more preferably 1.5 to 1.9 dtex. When the fineness of the cellulosic fibers such as cotton and rayon constituting the first sheet is within the above range, the cellulosic fibers themselves absorb liquid, and the interfiber spaces also retain liquid well, making it possible to improve the liquid absorbency of the first sheet.

[0020] The first sheet is made of cellulosic fibers, but may contain small amounts of other fibers, such as synthetic fibers such as polyester fibers and polypropylene fibers, within the scope of the effects of the present invention.

[0021] The spunbond nonwoven fabric constituting the second sheet has continuous fibers made of synthetic resin as its constituent fibers. Examples of such fibers include general polyethylene fibers, polypropylene fibers, and polyester fibers, and polyethylene fibers and polypropylene fibers are preferably used because of their good flexibility and excellent hydrophobicity. The cross-sectional form of the fiber can be a solid cross-section, a hollow cross-section, or the like. The fiber may be a single-phase cross-section fiber made of a single phase, but a composite cross-section fiber using multiple types of resins can also be applied. Among them, a composite cross-section fiber having a core-sheath structure with a core and a sheath can be preferably used.

[0022] The core-sheath fiber is preferably one in which a high melting point component is arranged in the core and a low melting point component with a melting point lower than that of the core component is arranged in the sheath. Examples of such a combination of components include a core made of polyester such as polyethylene terephthalate and a sheath made of polyethylene, and a core made of polypropylene and a sheath made of polyethylene. When the core-sheath fiber is spun to form a web, the web is heat-treated at a temperature equal to or higher than the softening point or melting point of the sheath and equal to or lower than the melting point of the core, and the sheath acts as a heat-fusible component while the core maintains its fibrous form. As a result, the fibers are thermally bonded to each other, and the web is turned into a spunbonded nonwoven fabric, resulting in a spunbonded nonwoven fabric that is excellent in both hydrophobicity and flexibility.

[0023] The second sheet formed of spunbond nonwoven fabric has a basis weight of 8 to 23 g / m 2 In the hygienic material of the present invention, the basis weight of the second sheet is preferably 8 g / m 2 As a result of the above, the required strength can be provided.

[0024] The fineness of the fibers constituting the second sheet is preferably 3 to 15 dtex. When the fineness is 3 dtex or more, voids and through-holes of appropriate size are formed in the surface direction of the skin side of the hygienic material, thereby improving the transfer of liquid to the absorbent material below. On the other hand, when the fineness is 15 tex or less, flexibility can be maintained. For these reasons, the single fiber fineness is more preferably 6 to 14 dtex.

[0025] In addition, the spunbonded nonwoven fabric has a basis weight and a single fiber fineness in the above-mentioned range, that is, a small basis weight and a fineness that is not too small, so that the spunbonded nonwoven fabric has through-holes and moderate voids. Therefore, when the spunbonded nonwoven fabric forming the second sheet and the cellulosic fiber constituting the first sheet are subjected to a hydroentanglement treatment, which is a means for laminating and integrating the spunbonded nonwoven fabric forming the second sheet with the cellulosic fiber constituting the first sheet, the cellulosic fiber is likely to be entangled in the through-holes and voids of the spunbonded nonwoven fabric. In addition, in the hygienic material obtained by lamination, liquid can be transferred well from the voids and through-holes of the spunbonded nonwoven fabric to the first sheet below. Therefore, although the second sheet composed of continuous fibers made of hydrophobic synthetic resin is located on the side directly contacting the skin, the liquid transfer to the first sheet below is good, so that the liquid absorbency is good even without the addition of a hydrophilic agent, and even a small amount of body fluid is easily permeated.

[0026] The second sheet is easily permeable to small amounts of body fluid even without the addition of a hydrophilic agent; however, addition of a hydrophilic agent may be preferable, as it reduces the contact angle with droplets and improves liquid compatibility, thereby improving the transfer of liquid to the first sheet underneath.

[0027] The hygienic material of the present invention has a first sheet made of cellulosic fibers, and therefore exhibits excellent liquid absorption. For example, when tested using 50 mL of 1% by mass physiological saline as described below, the liquid absorption amount can be 20 g or more. The liquid absorption amount is preferably 20 g or more, and particularly preferably 25 g or more.

[0028] The hygienic material of the present invention is a laminate of a first sheet made of cellulosic fibers and a second sheet on the skin side made of a spunbond nonwoven fabric, and therefore when tested, for example, using 30 mL of 1% by mass physiological saline as described below, the amount of wetback can be kept to 0.70 g or less, and excellent wetback prevention properties can be achieved. The amount of wetback is preferably 0.70 g or less, and particularly preferably 0.65 g or less. EXAMPLES

[0029] The characteristics in the following Examples and Comparative Examples were evaluated as follows.

[0030] (1)Liquid absorption The top sheet of a commercially available incontinence pad product (120cc) was slowly peeled off to expose the absorbent body inside, and the sanitary material of the examples and comparative examples was cut into a test piece measuring 20 cm in length and 5 cm in width, which was then reattached to the above-mentioned absorbent body to prepare the test sample 10 shown in FIG. 1. The test sample 10 was fixed on a 45-degree inclined surface 11. 50 mL of 1% by mass saline was prepared as a test liquid and poured into a funnel 12 with a plug at the end, and the test liquid 13 was once collected. The height from the test sample 10 to the bottom end of the funnel 12 was set to 2 cm, and the plug of the funnel 12 was removed, and the test liquid 13 was poured into the test sample 10.

[0031] At that time, the test liquid that had flowed down from the test sample 10 along the inclined surface 11 was weighed, and the liquid absorbency of the test sample 10 was evaluated based on the amount of liquid absorbed [g] calculated by the following formula. Amount of liquid absorbed [g] = 50 [g] - amount of liquid that flowed down [g]

[0032] (2) Prevents liquid from leaking back In the same manner as in the evaluation of "(1) Absorbency" above, the top sheet of the incontinence pad product (120cc) was slowly peeled off to expose the absorbent body inside, and the sanitary material of the examples and comparative examples was cut into a test piece measuring 20 cm in length and 5 cm in width, which was then reattached to the above-mentioned absorbent body to prepare the test sample 10 shown in FIG. 2. 30 mL of 1% by mass saline was prepared as the test liquid, and this test liquid was evenly injected into the test sample 10, after which a pressure of 4 kPa was applied by the weight 15 for 2 minutes. The weight 15 was then temporarily removed, and the weighed filter paper 14 was placed on the test sample 10, and a pressure of 4 kPa was again applied by the weight 15 for 2 minutes. The filter paper 14 was then weighed, and the liquid return prevention property of the test sample 10 was evaluated based on the amount of liquid return [g] calculated by the following formula. Liquid return amount [g] = Mass of filter paper containing test liquid after load application [g] - Mass of the filter paper containing the test liquid before loading [g]

[0033] Example 1 The continuous fiber spunbonded nonwoven fabric constituting the continuous fiber layer as the first sheet was made of core-sheath composite continuous fibers with a single fiber fineness of 7.3 dtex, the core being made of polyethylene terephthalate with a melting point of 260°C and the sheath being made of polyethylene with a melting point of 130°C. This continuous fiber spunbonded nonwoven fabric was partially thermocompressed to integrate the constituent fibers. The basis weight was 13 g / m 2 It was.

[0034] Rayon having a single fiber fineness of 1.7 dtex and a fiber length of 40 mm was used as the short fiber constituting the short fiber layer as the second sheet. The short fiber group made of this rayon was passed through a parallel carding machine to obtain a basis weight of 15 g / m 2 A staple fiber web of 1000 g was prepared.

[0035] Next, the two layers were laminated to form a short fiber web / continuous fiber nonwoven fabric, and the laminate with this two-layer structure was placed on a 100 mesh wire net.

[0036] Using a hydroentanglement machine with multiple 0.12 mm diameter nozzles arranged at 0.64 mm intervals, the above-mentioned two-layer laminate was hydroentangled by spraying water, thereby forming the laminate into a nonwoven fabric. The water was sprayed once from the short fiber web side at a water pressure of 2.8 MPa, once from the short fiber web side at a water pressure of 4.2 MPa, and then the laminate was inverted and sprayed twice from the continuous fiber nonwoven fabric side at a water pressure of 4.2 MPa. The laminate was then placed on a support having a 15-mesh woven fabric structure, and high-pressure water was sprayed three times from the short fiber web side at a water pressure of 7.0 MPa. Furthermore, in order to remove excess moisture from the obtained laminated nonwoven fabric, it was dried at 100°C for 90 seconds using a continuous hot air dryer, and the hygienic material of Example 1 was obtained.

[0037] Example 2 Instead of the sheath-core composite continuous fiber having a single fiber fineness of 7.3 dtex in Example 1, a continuous fiber layer was used as the first sheet, the component fiber of which was a sheath-core composite continuous fiber having a single fiber fineness of 13.3 dtex. The basis weight was 17 g / m 2 It was.

[0038] Other than that, the same procedure was followed as in Example 1 to obtain a sanitary material of Example 2.

[0039] Example 3 The staple fiber web constituting the staple fiber layer as the second sheet was the same as that in Example 1, with a basis weight of 15 g / m 2 Instead of the above, the basis weight is 10g / m 2 The following was used.

[0040] Other than that, the same procedure was followed as in Example 1 to obtain a hygienic material of Example 3.

[0041] Example 4 As the staple fiber web constituting the staple fiber layer as the second sheet, bleached cotton having a single fiber fineness of 1.7 dtex was used instead of the rayon staple fiber in Example 1. This cotton staple fiber group was passed through a parallel carding machine to obtain a basis weight of 15 g / m 2 A staple fiber web of 1000 g was prepared.

[0042] Other than that, the same procedure was followed as in Example 1 to obtain a sanitary material of Example 4.

[0043] Example 5 The same staple fiber web and continuous fiber nonwoven fabric as in Example 1 were prepared and then laminated to form a staple fiber web / continuous fiber nonwoven fabric structure, and this two-layer laminate was placed on a 100-mesh wire net.

[0044] Using a hydroentanglement machine with multiple 0.12 mm diameter nozzles arranged at 0.64 mm intervals, the above-mentioned two-layer laminate was hydroentangled by spraying water from the short fiber web side, thereby forming the laminate into a nonwoven fabric. The water was sprayed once from the short fiber web side at a water pressure of 2.8 MPa, once from the short fiber web side at a water pressure of 4.2 MPa, then the laminate was inverted and the high-pressure water was sprayed twice from the continuous fiber nonwoven fabric side at a water pressure of 4.2 MPa, and finally the laminate was again inverted and the high-pressure water was sprayed three times from the short fiber web side at a water pressure of 7.0 MPa. After that, in order to remove excess moisture from the obtained laminated nonwoven fabric, it was dried at 100°C for 90 seconds using a continuous hot air dryer, and the hygienic material of Example 5 was obtained.

[0045] Comparative Example 1 A sanitary material having only a continuous fiber layer and no short fiber layer was produced. In detail, the same continuous fiber spunbonded nonwoven fabric as in Example 1 was produced and used as the sanitary material of Comparative Example 1 as it was.

[0046] Comparative Example 2 A hygiene material having only a short fiber layer and no continuous fiber layer was produced. In detail, rayon having a single fiber fineness of 1.7 dtex and a fiber length of 40 mm was used as the short fiber constituting the short fiber layer. The rayon short fiber group was passed through a parallel carding machine to obtain a basis weight of 30 g / m2. 2 A staple fiber web of 1000 g was prepared.

[0047] Next, this short fiber web was placed on a 100 mesh wire net. Then, using a hydroentanglement treatment machine with a plurality of 0.12 mm diameter injection holes arranged at 0.64 mm intervals, water was injected into the above-mentioned short fiber web to perform hydroentanglement treatment, thereby forming the short fiber web into a nonwoven fabric. The water was injected once from the front side of the short fiber web at a water pressure of 2.8 MPa, once from the front side of the short fiber web at a water pressure of 4.2 MPa, and then the short fiber web was inverted and injected twice from the back side of the short fiber web at a water pressure of 4.2 MPa. Thereafter, the short fiber web was placed on a support having a 15 mesh woven fabric configuration, and high-pressure water was applied three times from the front side of the short fiber web at a water pressure of 7.0 MPa. Further, in order to remove excess moisture from the obtained nonwoven fabric, a drying treatment was performed at 100°C for 90 seconds using a continuous hot air dryer, and the hygienic material of Comparative Example 2 was obtained.

[0048] The evaluation results of the hygienic materials of Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Table 1.

[0049] [Table 1]

[0050] The sanitary material of Examples 1 to 5 all exhibited good performance in terms of both liquid absorption and liquid return prevention. In particular, in Examples 1 to 4, the mesh of the support used in integrating the continuous fiber spunbond nonwoven fabric and the staple fiber web by hydroentanglement treatment was 15 mesh, so that large voids were formed in the sanitary material by the water flow, which is expected to improve the transfer of liquid to the absorbent material located below the sanitary material.

[0051] In Example 2, the continuous fiber spunbonded nonwoven fabric forming the continuous fiber layer had a single fiber fineness of 13.3 dtex, which was thicker than the 7.3 dtex of Example 1. This resulted in the formation of many large voids and through-holes in the surface direction on the skin side of the sanitary material, which improved the transfer of liquid to the absorbent material located below the sanitary material compared to Example 1, and improved prevention of liquid backflow was observed.

[0052] In Example 3, the staple fiber web constituting the staple fiber layer was the same as in Example 1 with a basis weight of 15 g / m 2 Instead of the above, the basis weight is 10g / m 2 Since the surface area of ​​the rayon web in contact with the test liquid was reduced, the amount of liquid absorbed was reduced compared to Example 1. On the other hand, since the volume of the rayon web that retains the liquid was reduced, the amount of liquid wetting was reduced compared to Example 1, and improved prevention of liquid wetting was observed.

[0053] In Example 4, a cotton web was used as the short fiber web constituting the short fiber layer instead of the rayon web of Example 1, and the liquid absorption performance was comparable to that of Example 1. On the other hand, since cotton fiber has a higher liquid retention capacity than rayon fiber, the transfer of liquid to the absorbent material located below the sanitary material was reduced compared to Example 1, resulting in an increase in the amount of liquid return and a slight decrease in the ability to prevent liquid return.

[0054] In Example 5, the mesh of the support used when integrating the continuous fiber spunbond nonwoven fabric and the staple fiber web by hydroentanglement treatment was changed from 15 mesh in Examples 1 to 4 to 100 mesh. As a result, holes corresponding to the mesh were unlikely to exist in the plane direction of the rayon web on the non-skin side of the sanitary material, and rayon fibers were present evenly over the entire surface, which increased the surface area of ​​the rayon web that came into contact with the test liquid, improving liquid absorption compared to Example 1. On the other hand, the voids in the plane direction were smaller, which reduced the ability of the liquid to migrate to the absorbent material below compared to Example 1, and a slight decrease in the ability to prevent liquid backflow was observed.

[0055] In Comparative Example 1, the sanitary material was composed only of the continuous fiber spunbonded nonwoven fabric constituting the continuous fiber layer in Example 1, and no short fiber layer was used, so the liquid return prevention property was extremely good, but the liquid absorbency was poor.

[0056] In Comparative Example 2, the sanitary material was composed only of the rayon web constituting the short fiber layer in Example 1, and no continuous fiber spunbond nonwoven fabric was used. However, in order to form a self-supporting sanitary material, the basis weight was 15 g / m2 in Example 1. 2 Instead of 30g / m 2 As a result, the liquid absorbency was extremely good, but the ability to prevent liquid return was poor.

Claims

1. A sanitary material comprising a first sheet made of cellulosic fibers and a second sheet facing the skin, the second sheet being made of spunbond nonwoven fabric and laminated together.

2. 2. The hygienic material according to claim 1, wherein the first sheet is made of cotton fiber or rayon fiber.

3. 2. The hygienic material according to claim 1, wherein the fineness of the fibers constituting the second sheet is 3 to 15 decitex.

4. The hygienic material according to claim 1 or 3, characterized in that the second sheet is formed of a spunbond nonwoven fabric whose constituent fibers are core-sheath type composite fibers in which polyethylene terephthalate is arranged in the core and polyethylene is arranged in the sheath.

5. The basis weight of the first sheet is 7 to 23 g / m ２ 3. The sanitary material according to claim 1 or 2,

6. The weight of the second sheet is 8 to 23 g / m ２ 4. The sanitary material according to claim 1 or 3,

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