INCONTINENCE ARTICLE WITH PH REGULATOR

Abstract

The present invention relates to an incontinence article for absorption of bodily excretions, comprising an at least regionally liquid-permeable topsheet, a substantially liquid-impermeable backsheet, and an absorption body arranged between the topsheet and the backsheet, the incontinence article comprising a pH regulator between the topsheet and the backsheet at least regionally, characterized in that the pH regulator comprises monosodium citrate or disodium citrate.

Claims

1. An incontinence article for absorption of bodily excretions, comprising an at least regionally liquid-permeable topsheet, a substantially liquid-impermeable backsheet, and an absorption body arranged between the topsheet and the backsheet, the incontinence article comprising a pH regulator between the topsheet and the backsheet at least regionally, wherein the pH regulator comprises monosodium citrate or disodium citrate.

2. The incontinence article as claimed in claim 1, wherein the pH regulator further comprises trisodium citrate.

3. The incontinence article as claimed in claim 1, wherein the pH regulator consists of monosodium citrate.

4. The incontinence article as claimed in claim 1, wherein the pH regulator consists of disodium citrate.

5. The incontinence article of claim 1, wherein the pH regulator is particulate.

6. The incontinence article as claimed in claim 5, wherein at least 50 percent by weight of the pH regulator has a particle size of 10 to 2000 μm.

7. The incontinence article of claim 1, wherein the amount of pH regulator is 10 to 100 g/m.sup.2.

8. The incontinence article as claimed in claim 1, wherein the absorption body comprises at least one storage layer which comprises a superabsorbent polymer.

9. The incontinence article as claimed in claim 8, wherein the storage layer is substantially free of the pH regulator.

10. The incontinence article as claimed in claim 1, wherein the incontinence article further comprises a liquid absorption layer which forms a layer of the absorption body that directly faces the top sheet.

11. The incontinence article as claimed in claim 10, wherein the pH regulator is substantially positioned between the liquid absorption layer and an absorption body layer facing the backsheet.

12. The incontinence article as claimed in claim 1, wherein the incontinence article maintains a skin-friendly pH over at least two micturition events.

13. The incontinence article as claimed in claim 12, wherein the pH on a topside of the incontinence article that faces the skin is a value of 4.8-6.5.

14. An arrangement of incontinence articles as claimed in claim 1, wherein the arrangement comprises at least two incontinence articles, with at least a first incontinence article and a second incontinence article of the arrangement differing in at least one feature selected from the group consisting of size, absorption capacity in accordance with ISO11948-1 (1996), amount of pH regulator in g/m.sup.2, total amount of pH regulator per incontinence article, and number of absorption body layers.

15. An arrangement of incontinence articles as claimed in claim 1, wherein the arrangement comprises at least two incontinence articles, with at least a first incontinence article and a second incontinence article of the arrangement being different incontinence articles selected from the group consisting of incontinence pad, open-type incontinence diaper with closure systems, closed-type incontinence diaper, and bed pad.

16. The incontinence article as claimed in claim 6, wherein at least 50 percent by weight of the pH regulator has a particle size of 50 to 1200 μm.

17. The incontinence article as claimed in claim 6, wherein at least 50 percent by weight of the pH regulator has a particle size of 80 to 800 μm.

18. The incontinence article as claimed in claim 7, wherein the amount of pH regulator is 20 to 80 g/m.sup.2, further in particular 25 to 60 g/m.sup.2.

19. The incontinence article as claimed in claim 12, wherein the incontinence article maintains a skin-friendly pH over at least three micturition events.

20. The incontinence article as claimed in claim 13, wherein the pH on a topside of the incontinence article that faces the skin is a value of 5.0-6.2.

Description

[0065] Further features, details and advantages of the invention will become apparent from the accompanying claims and from the graphic depiction and following description of preferred embodiments of the invention and examples. In the drawing:

[0066] FIG. 1 shows a schematic depiction of an open-type incontinence diaper with closure elements in plan view as an exemplary embodiment of an incontinence article according to the invention

[0067] FIG. 2a shows schematically a cross-section through an incontinence article comprising a storage layer containing SAP material, a liquid absorption layer, and a pH regulator arranged in between

[0068] FIG. 2b shows schematically a cross-section through an incontinence article comprising two storage layers, SAP material, a liquid absorption layer, and a pH regulator arranged in between

[0069] FIG. 3 shows schematically positions of measurement points for surface pH measurement relative to a liquid absorption layer

[0070] FIG. 1 shows not to scale, but schematically, an incontinence article according to the invention, denoted overall by the reference number 17, which is, by way of example, an open-type incontinence diaper with closure elements for adults in the so-called T-shape. The incontinence diaper 17 comprises a main part (chassis), denoted overall by the reference number 65, having an absorption body 69 which absorbs body fluids. In this exemplary embodiment, the absorption body 69 comprises at least one storage layer 70, containing SAP material (not shown in FIG. 1), and a liquid absorption layer 71. The incontinence diaper 17 according to the invention contains a pH regulator 72 which is substantially arranged between the liquid absorption layer 71 and the at least one storage layer 70 of the absorption body, as described in more detail in FIGS. 2a and 2b. The absorption body 69 is arranged between two planar materials, specifically an at least regionally liquid-permeable topsheet 80 and a substantially liquid-impermeable backsheet 81 of the main part of the diaper 65.

[0071] Distinguishable on the incontinence diaper 17 are a longitudinal direction 73 and a transverse direction 74 of the incontinence diaper 17, the latter direction corresponding to a direction of the hip circumference of the user when the incontinence diaper is in place. The main part 65 comprises a front region 82 having front lateral longitudinal edges 83, a back region 64 having a first rear lateral longitudinal edge 66 and a second rear lateral longitudinal edge 67, and a crotch region 84 arranged in between. Adjacent to a respective longitudinal edge 85 of the crotch region 84, the main part 65 has an elasticized section in each case, and thus an elasticized leg opening section 86. In the case depicted, these elasticized leg opening sections 86 are formed by elastic threads which run between the topsheet 80 and backsheet 81 and are fixed to the topsheet 80 and/or backsheet 81 in a pretensioned state and which are curved in an arc and are therefore oriented at least with one component in the longitudinal direction 73 of the incontinence diaper 17.

[0072] On the T-shaped incontinence diaper 17, there are provided, in the back region 64 of the main part 65 in the transverse direction 74 of the incontinence diaper 17, a first elastic diaper side part 62 which extends laterally beyond the first rear lateral longitudinal edge 66 and a second elastic diaper side part 63 which extends laterally beyond the second rear lateral longitudinal edge 67, which elastic diaper side parts are, in the region of the rear lateral longitudinal edges 66 and 67, undetachably attached in an overlap region 87 to the back region 64 of the main part 65. By contrast, no diaper side parts are provided in the front region 82.

[0073] In an alternative variant embodiment, the incontinence diaper can also be in the form of an H-shaped incontinence diaper, in which case diaper side parts are then additionally formed in the front region and preferably on both sides, as shown in WO2005102241A1 for example. As a further variant embodiment, a closed-type incontinence diaper is also conceivable, in which case there is preferably respective attachment in the front region and in the back region of a stomach part and back part, which are joined to one another at respective lateral longitudinal edges of the stomach part and back part such that the incontinence diaper is annularly closed in the direction of the hip circumference, as shown in WO2013171068A1 for example. As a further variant embodiment, the incontinence article 17 can be in the form of a bed pad or incontinence pad.

[0074] The first elastic diaper side part 62 and the second elastic diaper side part 63 of the T-shaped incontinence diaper 17 each have at least one closure element 44 in the region of their free end 88 in the transverse direction 74 of the incontinence diaper 17. The closure element 44 is in the form of a preferably rectangular tab and is folded onto itself by the manufacturer. In case of use, the closure element 44 can be opened, i.e. unfolded, in order to place the incontinence diaper 17 on a user, with the first elastic diaper side part 62 and the second elastic diaper side part 63 overlapping the front region 82 of the main part 65 and the closure elements 44 being detachably adhesively fixed on the side of the front region 82 of the main part 65 that faces away from the user.

[0075] By way of example, FIGS. 2a and 2b each show schematically, not to scale, a cross-section through an incontinence article 18a, 18b, for example an open-type incontinence diaper with closure systems (as described in more detail in FIG. 1) or a closed-type incontinence diaper or an incontinence pad or a bed pad. The incontinence articles 18a, 18b comprise a liquid-permeable topsheet 80, a substantially liquid-impermeable backsheet 81 (thus in use), and an absorption body 76 arranged in between. The absorption body 76 of the incontinence article 18a (FIG. 2a) comprises a storage layer 70 containing fibrous material 70a, for example cellulose fibers or plastic fibers, and SAP material 70b, a liquid absorption layer 71, and a pH regulator 72 arranged in between. The liquid absorption layer 71 forms a layer of the absorption body 76 that directly faces the topsheet 80.

[0076] The storage layer 70 directly faces the backsheet and is substantially free of the pH regulator 72. The absorption body of the incontinence article 18b (FIG. 2b) additionally comprises a further layer, namely a layer 75 of the absorption body 76 that directly faces the backsheet 81 and that substantially consists of fibrous material 70a, for example cellulose fibers or plastic fibers, and is arranged between the storage layer 70 and the backsheet 81. The layer 75 directly facing the backsheet 81 is substantially free of pH regulator 72.

[0077] In the exemplary embodiments depicted in FIGS. 2a and 2b, the pH regulator 72 comprises particulate monosodium citrate of the type “Fine Granular F3500” from Jungbunzlauer. Said monosodium citrate has a particle size of 80 to 355 μm to an extent of 59 percent by weight and a purity of at least 99%. The amount of pH regulator 72 in this example is 30 g/m.sup.2.

[0078] The SAP material 70b is particulate in the cases depicted. In a conceivable variant, the SAP material can be fibrous or planar or foamy.

[0079] FIGS. 2a and 2b both show the cross-section through the incontinence article 18a and 18b, respectively, in the transverse direction 74, in the case of an incontinence diaper 17, for example in the crotch region (reference number 84 in FIG. 1, the elasticized leg opening sections 86 not depicted).

[0080] The liquid absorption layer 71 only partially covers the storage layer 70 of the absorption body 76 and, in the present case, has a smaller extent than the storage layer 70 (FIG. 2a) or the storage layer 70 and the layer 75 of the absorption body 76 that directly faces the backsheet 81 (FIG. 2b) in the transverse direction 74 of the incontinence article 18 resting flat. Alternatively, the liquid absorption layer can completely cover the storage layer and/or the layer 75 of the absorption body 76 that directly faces the backsheet 81.

[0081] In this example (FIG. 2b), the storage layer 70 has, in the transverse direction 74, substantially the same extent as the layer 75 of the absorption body 76 that directly faces the backsheet 81. However, the storage layer 70 and the layer 75 of the absorption body 76 that directly faces the backsheet 81 can also have different extents.

EXAMPLE 1: PH REGULATION BY MONOSODIUM CITRATE OR DISODIUM CITRATE COMPARED TO CITRIC ACID

[0082] 1A: An adult incontinence diaper was produced with a pH regulator consisting of monosodium citrate (first incontinence diaper 1A, according to the invention). The incontinence diaper 1A comprised the following components in the arrangement specified: [0083] Topsheet: SMS nonwoven material, 12 g/m.sup.2, type 3000063 from Avgol LTD [0084] Liquid absorption layer: Nonwoven material carded and thermally bonded (“air-through-bonded”), Bico/PES, 40 g/m.sup.2, dimensions of 90×270 mm (0.0243 m.sup.2), type 11040WC0A from Berry [0085] pH regulator: 25 g/m.sup.2 monosodium citrate, purity of >95%, nonhydrogenated, total amount per incontinence article of 0.6 g, calculated total molar amount of monosodium citrate per incontinence article of 0.003 mol, catalog number 21533 from Thermo Fisher Scientific [0086] Storage layer: 21.5 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute; mixed with 13.5 g of particulate SAP material (type SXM 9791 from Evonik) [0087] Layer of the absorption body that faces the backsheet: 34.8 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute [0088] Backsheet: Nonwoven film laminate, 18 g/m.sup.2, Hyfol PE soft textile, type 14202 from RKW

[0089] 1B: A further adult incontinence diaper was produced with a pH regulator consisting of disodium citrate (second incontinence diaper 1B, for comparison, according to the invention).

[0090] The incontinence diaper 1B comprised the following components in the arrangement specified: [0091] Topsheet: SMS nonwoven material, 12 g/m.sup.2, type 3000063 from Avgol LTD [0092] Liquid absorption layer: Nonwoven material carded and thermally bonded (“air-through-bonded”), Bico/PES, 40 g/m.sup.2, dimensions of 90×270 mm (0.0243 m.sup.2), type 11040WC0A from Berry [0093] pH regulator: 31 g/m.sup.2 disodium citrate, purity of 99%, hydrated form (disodium hydrogencitrate sesquihydrate), total amount per incontinence article of 0.75 g, calculated total molar amount of disodium citrate per incontinence article of 0.003 mol, catalog number 25024 from Thermo Fisher Scientific [0094] Storage layer: 21.5 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute; mixed with 13.5 g of particulate SAP material (type SXM 9791 from Evonik) [0095] Layer of the absorption body that faces the backsheet: 34.8 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute [0096] Backsheet: Nonwoven film laminate, 18 g/m.sup.2, Hyfol PE soft textile, type 14202 from RKW

[0097] 1C: A further adult incontinence diaper was produced with a pH regulator consisting of citric acid (third incontinence diaper 1C, for comparison, not according to the invention). The incontinence diaper 1C comprised the following components in the arrangement specified: [0098] Topsheet: SMS nonwoven material, 12 g/m.sup.2, type 3000063 from Avgol LTD [0099] Liquid absorption layer: Nonwoven material carded and thermally bonded (“air-through-bonded”), Bico/PES, 40 g/m.sup.2, dimensions of 90×270 mm (0.0243 m.sup.2), type 11040WC0A from Berry [0100] pH regulator: 26 g/m.sup.2 citric acid, purity of at least 99.5%, nonhydrogenated, total amount per incontinence article of 0.625 g, calculated total molar amount of citric acid per incontinence article of 0.003 mol, article number 471A1F, “citric acid anhydrous pharm” from Barcelonesa [0101] Storage layer: 21.5 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute; mixed with 13.5 g of particulate SAP material (type SXM 9791 from Evonik) [0102] Layer of the absorption body that faces the backsheet: 34.8 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute [0103] Backsheet: Nonwoven film laminate, 18 g/m.sup.2, Hyfol PE soft textile, type 14202 from RKW

[0104] The pH regulator was arranged between the liquid absorption layer and the storage layer in the first incontinence diaper 1A and second incontinence diaper 1B and third incontinence diaper 10.

[0105] For better comparability of pH regulation in the first incontinence diaper 1A and second incontinence diaper 1B and third incontinence diaper 10, the respective total amount of pH regulator per incontinence article was chosen such that a substantially equal total molar amount of the respective pH regulator per incontinence article of 0.003 mol was present in each case (see Table 1).

TABLE-US-00001 TABLE 1 pH regulators used in Example 1 1A 1B 1C (with MSC) (with DSC) (with CA) Water of crystallization Non- Sesqui- Non- hydro- hydrate hydro- genated genated Molarity [g/mol] 214.11 263.1 192.13 Total amount per incontinence 0.6 0.75 0.625 article [g] Surface area covered by pH 0.0243 0.0243 0.0243 regulator [m.sup.2] Amount of pH requlator [g/m.sup.2] 25 31 26 Total molar amount per 0.003 0.003 0.003 incontinence article [mol] MSC, monosodium citrate; DSC, disodium citrate; CA, citric acid

[0106] As described in more detail below in the test method section, three consecutive micturition events were simulated with a urine substitute liquid and the pH values were measured on a respective outer topside of the topsheet of the first and second and third incontinence article in the region of the liquid absorption layer 71. FIG. 3 shows the positions of four measurement points 3 relative to the liquid absorption layer 71 of the first and second and third incontinence article (when viewing the topsheet). A transverse extent A of the liquid absorption layer 71 was 90 mm in each case. A longitudinal extent B of the liquid absorption layer 71 was 270 mm. The pH was measured at all four measurement points 3, and the 4 measurement values at each time were used to calculate an average value, which is shown in Table 3. Moreover, the average pH values obtained after every simulated micturition were used to calculate a mean value and an associated standard deviation, which are likewise presented in Table 3. The measurement points 3 were distributed in the longitudinal direction 73 of the respective liquid absorption layer in such a way that a distance e between a measurement point 3 that is closest in the longitudinal direction 73 to a respective transverse edge 1 of the liquid absorption layer 71 and the respective transverse edge 1 that is closest in the longitudinal direction 73 was 45 mm. A distance d between two measurement points 3 following one another in the longitudinal direction 73 was 60 mm in this example.

[0107] A distance c between a measurement point 3 that is closest in the transverse direction 74 to a respective longitudinal edge 2 of the respective liquid absorption layer 71 and the respective longitudinal edge 2 that is closest in the transverse direction 74 was 25 mm. A distance f between two measurement points 3 following one another in the transverse direction 74 was 40 mm in this example.

[0108] Respective liquid volumes of the three simulated micturitions can be gathered from Table 2.

TABLE-US-00002 TABLE 2 Volumes of urine substitute liquid used in Example 1 Proportion of maximum Liquid volume absorption capacity [ml] [%] First simulated micturition 300 45 Second simulated micturition 150 22.5 Third simulated micturition 150 22.5 Total 600 90

[0109] The pH values measured at the various times at the described four measurement points 3 can be gathered from Table 3.

TABLE-US-00003 TABLE 3 pH regulation, monosodium citrate and disodium citrate compared to citric acid, pH values assigned to individual times are average values from four measurement values in each case First simulated Second simulated Third simulated micturition micturition micturition 1A 1B 1C 1A 1B 1A 1B 1C Time (with (with (with (with (with 1C (with (with (with (with [min]* MSC) DSC) CA) MSC) DSC) CA) MSC) DSC) CA) 1 5.2 5.0 4.3 5.4 5.7 5.4 5.3 5.7 5.4 3 5.3 5.3 4.0 5.4 5.6 5.3 5.5 5.7 5.3 5 5.2 5.3 4.3 5.5 5.5 5.3 5.4 5.7 5.4 10 5.3 5.1 4.5 5.5 5.4 5.3 5.5 5.8 5.4 15 5.2 5.3 4.1 5.4 5.7 5.4 5.5 5.7 5.6 20 5.1 5.3 4.3 5.5 5.6 5.4 5.5 5.6 5.7 MV 5.2 5.2 4.3 5.5 5.6 5.4 5.5 5.7 5.5 SD 0.1 0.1 0.2 0.1 0.1 0.1 0.1 0.1 0.1 MSC, monosodium citrate; DSC, disodium citrate; CA, citric acid MV, mean value of the preceding average pH values in the respective column for the micturition indicated in the column heading; SD, standard deviation *After the respective simulated micturition

[0110] The third incontinence diaper 10 containing citric acid yielded pH values of 4.0 to 4.5 after the first simulated micturition, and was distinctly below the skin-friendly range with a mean value of pH 4.3±SD=0.2. It was only with the second and third simulated micturition two and five hours after the start of the test that there was a skin-friendly pH within the range from 5.4 to 5.5 (mean values pH 5.4±SD=0.1 and pH 5.5±SD=0.1).

[0111] The second incontinence diaper 1B containing disodium citrate already yielded skin-friendly pH values of pH 5.0 to 5.3 (mean value pH 5.2±SD=0.1) after the first simulated micturition, and increased only slightly after the second and third simulated micturition (mean values pH 5.6±SD=0.1 and pH 5.7±SD=0.1).

[0112] The first incontinence diaper 1A containing monosodium citrate likewise maintained a relatively constant skin-friendly pH of 5.1 to 5.5 over three simulated micturition events and kept the pH constant at pH 5.4 to 5.5 particularly after the second and third simulated micturition (mean values pH 5.5±SD=0.1 in each case).

[0113] In particular, it was surprising that both the first incontinence diaper 1A and the second incontinence diaper 1B had an approximately identical, skin-friendly pH after the first simulated micturition (mean value pH 5.2±SD=0.1 in each case), but a distinctly higher pH than the third incontinence diaper 10 containing citric acid (mean value pH 4.3±SD=0.2), even though all three incontinence diapers had a substantially identical total molar amount of pH regulator (0.003 mol in each case). Furthermore, it was surprising that the pH values of both the first incontinence diaper 1A and the second incontinence diaper 1B, after the second and third simulated micturition, did not rise or did not rise substantially more strongly than the pH values of the incontinence diaper 10 containing citric acid (see mean values in Table 3).

[0114] The first incontinence diaper 1A containing monosodium citrate yielded only slightly better pH regulation than the second incontinence diaper 1B containing disodium citrate over the entire period of the test, with a substantially identical total molar amount of pH regulator (0.003 mol in each case). Therefore, when using monosodium citrate, approximately 20% less pH regulator can be used by weight compared to the hydrogenated disodium citrate used in this example. Thus, besides technical advantages as described above, advantages as regards economy and logistics are additionally also yielded by the choice of pH regulator.

EXAMPLE 2: PH REGULATION BY A PH REGULATOR CONSISTING OF CITRIC ACID AND TRISODIUM CITRATE

[0115] 2A: An adult incontinence diaper was produced with a pH regulator known in the prior art (WO2012121932A1) and consisting of a mixture of trisodium citrate and citric acid, the mixing ratio being 6.2:1 (w/w) (fourth incontinence diaper 2A, for comparison, not according to the invention). The incontinence diaper 2A comprised the following components in the arrangement specified: [0116] Topsheet: SMS nonwoven material, 12 g/m.sup.2, type 3000063 from Avgol LTD [0117] Liquid absorption layer: Nonwoven material carded and thermally bonded (“air-through-bonded”), Bico/PES, 40 g/m.sup.2, dimensions of 90×270 mm (0.0243 m.sup.2), type 11040WC0A from Berry [0118] pH regulator: 31 g/m.sup.2 (total amount per incontinence article of 0.75 g) trisodium citrate:citric acid in a ratio of 6.2:1 (w/w) [0119] Storage layer: 21.5 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute; mixed with 13.5 g of particulate SAP material (type SXM 9791 from Evonik) [0120] Layer of the absorption body that faces the backsheet: 34.8 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute [0121] Backsheet: Nonwoven film laminate, 18 g/m.sup.2, Hyfol PE soft textile, type 14202 from RKW

[0122] 2B: An adult incontinence diaper was produced with a pH regulator known in the prior art (WO2012121932A1) and consisting of a mixture of trisodium citrate and citric acid, the mixing ratio being 7.2:1 (w/w) (fifth incontinence diaper 2B, for comparison, not according to the invention). The incontinence diaper 2B comprised the following components in the arrangement specified: [0123] Topsheet: SMS nonwoven material, 12 g/m.sup.2, type 3000063 from Avgol LTD [0124] Liquid absorption layer: Nonwoven material carded and thermally bonded (“air-through-bonded”), Bico/PES, 40 g/m.sup.2, dimensions of 90×270 mm (0.0243 m.sup.2), type 11040WC0A from Berry [0125] pH regulator: 31 g/m.sup.2 (total amount per incontinence article of 0.75 g) trisodium citrate:citric acid in a ratio of 7.2:1 (w/w) [0126] Storage layer: 21.5 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute; mixed with 13.5 g of particulate SAP material (type SXM 9791 from Evonik) [0127] Layer of the absorption body that faces the backsheet: 34.8 g of cellulose fibers (“fluff”), type CoosAbsorb S from Resolute [0128] Backsheet: Nonwoven film laminate, 18 g/m.sup.2, Hyfol PE soft textile, type 14202 from RKW

[0129] The trisodium citrate used in the fourth incontinence diaper 2A and fifth incontinence diaper 2B had a purity of >99% and was present as a dihydrate (article number 27833.363 from VWR chemicals). The citric acid was present in nonhydrogenated form and had a purity of at least 99.5% (article number 471A1F, “citric acid anhydrous pharm” from Barcelonesa).

[0130] The pH regulator was arranged between the liquid absorption layer and the storage layer in the fourth incontinence diaper 2A and fifth incontinence diaper 2B.

[0131] As described in more detail with regard to Example 1 and in the test method section, three consecutive micturition events were simulated with a urine substitute liquid and the pH values were measured on the respective outer topside of the topsheet of the fourth and fifth incontinence article in the region of the liquid absorption layer 71. FIG. 3 shows the positions of the four measurement points 3 relative to the liquid absorption layer 71 of the fourth and fifth incontinence article (when viewing the topsheet). The transverse extent A of the liquid absorption layer 71 was 90 mm in each case. The longitudinal extent B of the liquid absorption layer 71 was 270 mm. The pH was measured at all four measurement points 3, and the 4 measurement values at each time were used to calculate an average value, which is shown in Table 5. Moreover, the average pH values obtained after every simulated micturition were used to calculate a mean value and the associated standard deviation, which are likewise presented in Table 5. The measurement points 3 were distributed in the longitudinal direction 73 of the respective liquid absorption layer in such a way that a distance e between a measurement point 3 that is closest in the longitudinal direction 73 to a respective transverse edge 1 of the liquid absorption layer 71 and the respective transverse edge 1 that is closest in the longitudinal direction 73 was 45 mm. A distance d between two measurement points 3 following one another in the longitudinal direction 73 was 60 mm in this example.

[0132] A distance c between a measurement point 3 that is closest in the transverse direction 74 to a respective longitudinal edge 2 of the respective liquid absorption layer 71 and the respective longitudinal edge 2 that is closest in the transverse direction 74 was 25 mm. A distance f between two measurement points 3 following one another in the transverse direction 74 was 40 mm in this example.

[0133] The liquid volumes of the three simulated micturitions can be gathered from Table 4.

TABLE-US-00004 TABLE 4 Volumes of urine substitute liquid used in Example 2 Proportion of maximum Liquid volume absorption capacity [ml] [%] First simulated micturition 300 45 Second simulated micturition 150 22.5 Third simulated micturition 150 22.5 Total 600 90

[0134] The pH values measured at the various times at the described measurement points 3 can be gathered from Table 5.

TABLE-US-00005 TABLE 5 pH regulation, pH regulator consisting of citric acid and trisodium citrate, pH values assigned to individual times are average values from four measurement values in each case First simulated Second simulated Third simulated micturition micturition micturition Time 2A 2B 2A 2B 2A 2B [min]* (6.2:1) (7.2:1) (6.2:1) (7.2:1) (6.2:1) (7.2:1) 1 5.7 5.6 5.8 5.7 5.9 5.8 3 5.5 5.7 5.8 5.8 5.9 5.9 5 5.7 5.7 5.8 5.8 5.8 5.9 10 5.6 5.6 5.9 5.8 5.8 5.8 15 5.6 5.7 5.9 5.8 5.9 5.8 20 5.6 5.7 5.9 5.8 5.9 5.8 MV 5.6 5.7 5.9 5.8 5.9 5.8 SD 0.1 0.1 0.1 0.0 0.1 0.1 MV, mean value of the preceding average pH values in the respective column for the micturition indicated in the column heading; SD, standard deviation *After the respective simulated micturition

[0135] The fourth and fifth incontinence diapers 2A and 2B containing the known pH regulator consisting of a mixture of trisodium citrate and citric acid in various mixing ratios yielded pH values of 5.5 to 5.7 after the first simulated micturition. After the second and third simulated micturition, the respective pH value in the fourth and fifth incontinence diaper rose to relatively high pH values of 5.7 to 5.9. Despite different mixing ratios of trisodium citrate and citric acid, the fourth and fifth incontinence diaper 2A and 2B showed approximately identical pH regulation, and so, in this example, neither mixing ratio offered an advantage over the other.

[0136] Looking at both Examples 1 and 2 together, it becomes apparent that the pH regulator comprising monosodium citrate of the first incontinence diaper 1A or disodium citrate of the second incontinence diaper 1B was superior to all the other incontinence diapers tested—the third incontinence diaper 10, fourth incontinence diaper 2A and fifth incontinence diaper 2B— since the pH values of the first incontinence diaper 1A and second incontinence diaper 1B were within the skin-friendly range over all three simulated micturitions; in particular, the pH values remained relatively constant within a narrow range, and further in particular, there was no substantial drop in pH values after the first micturition and no substantial rise with a total of three simulated micturitions even over more than 5 hours.

Test Method for pH Measurement on the Surface of an Incontinence Article:

[0137] A urine substitute solution is used to carry out a pH measurement on the surface of an incontinence article, in particular on an outer topside of the topsheet of the incontinence article. The urine substitute solution is a 0.9% (w/v) solution of sodium chloride (NaCl) in distilled water, prepared in accordance with ISO 11984-1 (1996), that has been adjusted to pH 6.8 using sodium hydroxide (NaOH). Such a solution has long been known in the common general knowledge in the art and the preparation thereof is part of the routine methods in the technical field.

[0138] The incontinence article to be tested is spread out flat with the topsheet side facing upward, completely unfolded if necessary, and fixed to a base if necessary.

[0139] The test is carried out in accordance with ISO 11984-1 (1996) at a temperature of 23° C.±2° C. and a relative air humidity of 50%±5%. The incontinence article to be tested and the urine substitute liquid are preconditioned accordingly in accordance with ISO 11984-1 (1996).

[0140] In order to represent a usage situation relatively realistically and to track the pH development or the buffering effect of the pH regulator over a relatively long usage period with multiple micturition events, three micturition events over a period of five hours are simulated in the course of the test as described below. Here, the incontinence article is loaded overall with a liquid volume corresponding to approximately 90% of a maximum absorption capacity of the incontinence article.

[0141] The volumes of the first and second and third simulated micturition are therefore to be chosen such that a total volume of the first and second and third simulated micturition corresponds to approximately 90% of the maximum absorption capacity of the incontinence article. At the same time, a volume of a first simulated micturition corresponds to 45% to 50% of the maximum absorption capacity of the incontinence article. A respective volume of a second and a third simulated micturition is substantially identical and corresponds in each case to 20% to 22.5% of the maximum absorbent capacity.

[0142] If the maximum absorption capacity of an incontinence article is unknown, the maximum absorption capacity is determined in advance in accordance with ISO 11984-1 (1996) on the basis of a second comparable incontinence article, for example an incontinence article which can be classified under the same absorbency and size and product type and optionally removed from the same packaging as the incontinence article to be tested.

[0143] A volume of the urine substitute solution corresponding to 50% of the maximum absorption capacity of the incontinence article is poured onto the dry incontinence article within 30 seconds for the purpose of simulating a first micturition, specifically in such a way that the urine substitute solution hits the incontinence article in a region in which the micturation liquid would also hit the incontinence article during a micturition event during use. If this region should not be absolutely certain, the urine substitute solution should hit the absorption body centrally, in particular in the region of a transverse central axis of the absorption body. If the incontinence article comprises a liquid absorption layer or liquid distribution layer, the urine substitute solution is poured onto the incontinence article especially centrally within a region formed by the liquid absorption layer or liquid distribution layer.

[0144] Two hours after starting the first simulated micturition with the first volume of urine substitute solution, a second volume of urine substitute solution corresponding to 20% of the maximum absorbent capacity of the incontinence article is poured onto the incontinence article, as described above, in order to simulate a second micturition.

[0145] Five hours after the start of loading with the first volume of urine substitute solution, a third volume of urine substitute solution corresponding to 20% of the maximum absorbent capacity of the incontinence article is poured onto the incontinence article, as described above, in order to simulate a third micturition.

[0146] After each of the three simulated micturition events, the pH is measured on the outer topside of the topsheet of the incontinence article 1, 3, 5, 10, 15 and 20 min after the end of the respective simulated micturition. To this end, the pH is measured at, in each case, 4 measurement points which are spaced from one another in the longitudinal and/or transverse direction of the incontinence article spread out flat, and an average value of the four measured values is formed. If a fluid absorption layer or fluid distribution layer is present, the measurements should be made within the region formed by said layer. In any case, the measurement points should be arranged within a region covered by pH regulator.

[0147] The measurement points should be spaced from one another, in particular should at least not overlap with one another. It is important to ensure that the measurement points on the incontinence article are not too dry in order to obtain reliable measurement results. The positions of the 4 measurement points should preferably be retained for all measurements, but it is also possible to vary the position of one or more measurement points, for example if one measurement point should be too dry at the time of a later measurement. This may be the case, for example, for incontinence articles exhibiting particularly low rewetting, in particular 15 and/or 20 minutes after the respective simulated micturition. If at least two suitable measurement points should not be available for a measurement at a specific time, the measurement is only evaluated at whatever are the other times after the end of the respective simulated micturition. If only two or three measurement points should be available for a measurement, an average value of the two or three measured values should be formed.

[0148] Owing to the routine nature of such pH measurements in the technical field, it is easily possible for a person skilled in the art to assess whether a possible measurement point is too dry.

[0149] In principle, the measurement can be carried out with any measuring device judged by a person skilled in the art to be suitable for surface pH measurement. For example, the electrodes from HANNA Instruments, models HI14142 or HI1413, are suitable. Before starting the measurement, the measuring device is calibrated according to the manufacturer's specifications.