MXPA01005876A - An absorbent article having a material laminate that comprises a liquid permeable top sheet and a liquid permeable liquid transfer sheet - Google Patents

Abstract

An absorbent article, such as a diaper, sanitary napkin, incontinence protector, wound dressing or the like, comprising an absorbent body (12) enclosed between a liquid-impermeable backing sheet (11) and a laminate (1) in the form of a liquid-permeable top sheet (2) and a liquid-permeable liquid transfer sheet (3), with the liquid transfer sheet (3) lying proximal to the absorbent body (12), in which article the liquid-permeable top sheet (2) and the liquid transfer sheet (3) are joined together and in which the absorbent body includes partially neutralised superabsorbent material.

Description

AN ABSORBENT ARTICLE THAT HAS A LAMINATE OF MATERIAL THAT COMPRISES A SUPERIOR COVER PERMEABLE TO THE LIQUID AND A TRANSFER SHEET (LIQUID PERMEABLE TO LIQUID) The present invention relates to an absorbent article comprising an absorbent body enclosed between a back cover impervious to liquid and a laminate of material in the form of an outer sheet permeable to liquid or top cover and a liquid permeable liquid transfer sheet, with the liquid permeable transfer sheet which is located next to the absorbent body.

BACKGROUND 15 A common problem encountered with absorbent articles such as diapers, sanitary napkins, incontinence guards and the like is that their use can lead to undesirable side effects such as skin irritation and associated problems. with smells of body wastes. These problems can arise as a result of occlusion, the presence of moisture and de factoreí; mechanical, microbial and enzymatic, all of which coact in mutual form to different degrees and amplify the effect of each other. Several undesirable side effects may arise also as a result or in conjunction with an increase in pH. US Pat. No. 3,794,034 discloses the importance of pH in the absorbent article and f "teaches the impregnation of the article with pH-regulating substances, which allows the pH in the article to be maintained between 3.6 and 6.0, which is beneficial with respect to both the inhibition of the growth of undesirable bacteria and with it the occurrence of undesirable odors and also helps to avoid the negative effect on the skin of the user. The Swedish patent application SE 9702298-2 teaches the use of an absorbent article which includes a pH regulating substance in the form of a partially neutralized superabsorbent material where, after wetting, the pH in the article will be between 3.5 and 4.9. An absorbent article according to the document SE 9702298-2 reduces the risk of skin irritation and also the problems associated with bad odors. A conventional superabsorbent material has a degree of neutralization of about 70%, considering that the partially neutralized superabsorbent material has a lower degree of neutralization.

BRIEF DESCRIPTION OF THE INVENTION The object of the present invention is to further reduce the risk of irritation of the skin, such as contact dermatitis. example. This is achieved with an absorbent article that includes an absorbent body comprising a partially neutralized superabsorbent material and a permeable fibrous top cover *. to liquid that is thermally bonded to a transfer sheet 5 of porous liquid in discrete regions (e.g., dotted / linear regions). The invention therefore relates to absorbent articles, such as diapers, sanitary napkins, incontinence guards, wound dressings and the like comprising a The absorbent body is enclosed between a liquid-impermeable backsheet and a laminate of material comprised of a sheet of liquid-permeable fibrous material such as a top cover and a sheet of liquid-permeable, porous and elastic material, such as a transfer sheet. liquid that is located next to the absorbent body, wherein the material laminate has a flat extension and a direction of thickness perpendicular to the planar extension wherein at least one of the sheets of material comprises thermoplastic material, and wherein two sheets of material are joined together Joints through joining means the locations within which the thermoplastic material is caused to soften at least partially or melt and thereby join the two sheets together and wherein the absorbent body includes partially neutralized superabsorbent and wherein the bonding regions of sheet or locations on the laminate are extend in the thickness direction of the laminate through the top cover and at least through a part of the liquid transfer sheet. The plastic cover is used as the top cover in many, types of absorbent articles. The benefit achieved through a fiber structure is that it reduces the risk of occlusion, which, in turn, reduces the risk of skin irritation. This is because a fiber structure is not as dense as a film. A fibrous top cover also has a normally smoother and more uniform surface for the skin, thereby reducing the mechanical effect of the top cover against the skin (eg skin irritation as the user moves). The benefit achieved by an acquisition layer of porous liquid or sheet between the liquid-permeable top cover and the absorbent body, which is thermally bonded to the top cover in discrete regions, is that the ventilation of the fibrous outer sheet is retained for a better effect than when the entire surface of the upper sheet or at least a large part of the surface thereof is attached to the surface of the liquid acquisition sheet. The discrete joints also normally provide in the thickness direction of the laminate, a denser structure than in the unbonded parts, which allows the liquid to be guided more easily at the locations attached to the porous liquid acquisition structure that is place inward Because the absorbent body includes material partially neutralized superabsorbent the pH will be reduced when using said body, thereby counteracting undesirable side effects, such as odors and irritation of the skin. This has a very strong effect on the user in combination with a drier and softer upper cover or outer sheet that confronts the user during use. A typical degree of neutralization is about 70%, although the degree of neutralization will be less in the case of the present invention. The invention is particularly suitable for use in the prevention of diaper rash, among other things.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in greater detail with reference to the figures of the accompanying drawings, in which Figure 1 illustrates from above a laminate included in the absorbent article according to the invention; Figure 2 is a sectional view through the laminate of Figure 1 taken on line 11-11 in said figure; Figure 3 illustrates a first bonding pattern; Figure 4 illustrates a second joining pattern; Figure 5 illustrates a third bonding pattern; Figure 6 illustrates a fourth bonding pattern; Figure 7 illustrates a fifth binding pattern; Figure 8 illustrates a first embodiment of the invention in the form of an incontinence guard; Figure 9 is a diagrammatic illustration of ammonia production in a reference product as compared to a reference product 4; and Figure 10 is a diagrammatic illustration of the pH of the skin surface when a test product is used that includes a conventional absorbent body compared to the use of a corresponding test product 4.

DESCRIPTION OF THE MODALITIES The invention relates to absorbent articles such as diapers, sanitary napkins, incontinence guards, wound dressings. Figure 8 shows by way of example an incontinence protector including an absorbent body or pad 12 enclosed between a liquid impermeable backsheet 11 and a material laminate 1 comprising a sheet of liquid permeable fibrous material 2 as an upper cover and a sheet of liquid permeable porous elastic material 3, a liquid transfer sheet 3. The liquid transfer sheet 3 faces the absorbent body 12 and the material laminate 1 has a flat extension and a direction of thickness perpendicular to said flat extension. At least one of the material sheets 2, 3 includes the thermoplastic material and the two sheets 2, 3 are joined together together through joining regions 4 on the laminate 1, whereby the thermoplastic material in said regions becomes at least partially smooth or fuses and in this way the two sheets of material 2, 3 are joined together. The body Absorbent includes partially neutralized superabsorbent. The joining regions of the laminate extend in the thickness direction of the laminate 1 through the upper sheet 2 and at least partially through the liquid transfer sheet 3. The joining regions on the laminate 1 are placed in two or more groups 5, with at least two joint locations 4 in each group 5, whereby the greatest distance between two mutually adjacent joint locations 4 in a given group is less than the shortest distance between each group 5 and its nearest adjacent group 5, said laminate 1 which thus tends between bonding locations 4 in each bonding group 5 bonding free regions 6 having a higher density than those bonding free regions 9 in the laminate which are located between the joint groups 5. The laminate is described in detail with reference to Figures 1-7. The laminate 1 illustrated in FIGS. 1 and 2 includes a first sheet of material 2, the upper sheet 2, and a second sheet of material 3, the liquid transfer sheet 3. The first sheet of material 2 is conventionally comprised of a relatively thin nonwoven material. The non-woven material can be produced in many forms, for example, by carding or spinning a fibrous mesh and then joining the mesh. A meltblowing technique can be used to deposit short fibers in the form of a fiber mesh. The fibers in the non-woven material may be joined in any one of a number of different ways. For example, different types of binder can be used. In addition, the heat-blown components present in the material can be used to effect bonding by ultrasound or by the application of heat. Other joining methods are sewing and hydroentanglement. A combination of different joining methods can also be used. When the laminate is used as a liquid-permeable upper material on an absorbent article, the first sheet of material 2, the top cover 2, is the sheet which is intended to be located close to the user of the article. It is important that the first sheet has a smooth and uniform surface against the user.

The second sheet of material 3, the liquid transfer sheet 3, will preferably be thicker than the sheet of the material 2, and is comprised of an elastic, porous fiber material, having a thickness from 0.5 to 4mm. This second sheet of material 3 serves as a liquid transfer sheet when the laminate is mounted on the absorbent article as an upper cover. The second sheet of material 3 will thus preferably be able to accommodate large volumes of liquid in a small space of time and distribute or disperse the liquid in the container. plane of said sheet of material, pass the absorbent liquid placed under the laminate 1, and also be able to temporarily store the liquid that does not have the time to be < • Absorbed by the absorbent body. Materials that are particularly suitable for use in the liquid transfer sheet 3 are synthetic fiber wadding, fiber layers bonded or non-bonded, bulky nonwoven material. A particular type of fiber material that can be used in this context is tow, by which fiber or fiber is essentially represented. long or infinitely parallel fiber filaments that exist in the form of layers or cords. Another suitable material in this context is the porous hydrophilic foam material. The second sheet of material may also consist of two or more layers of different material or one and the same type of material. A non-limiting example of a laminate forming the top cover of an absorbent article of the invention may be mentioned as a composite nonwoven material comprised of a first sheet of material 2 of non-woven synthetic fiber material having a weight per unit. of area between 10 and 50 g / m2 and one second sheet of material 3 comprised of synthetic fiber wadding and having a weight per unit area of between 20 and 100 g / m2. At least the first sheet 2 and preferably both sheets 2, 3 will include thermoplastic material. The suitable thermoplastic material is polyester, such as polyethylene and polypropylene and polyamides, polyester and similar. Other types of bicomponent fibers can be used.

The two sheets 2, 3 are joined through a large number of joint locations 4. The joint locations 4 are essentially point-like and have been formed by compression of laminate 1 and supplying power simultaneously. The thermoplastic material has been smoothed or fused at the joint locations 4, so as to join the two sheets 2, 3 of the laminate 1. The first and second sheets 2, 3 are joined together substantially by thermal bonds or ultrasonic joints in the form of welding, for example. The welding pattern formed in it has a three-dimensional structure. The joint locations 4 are placed in groups 5 with 4 joint locations 4, in each group 5. The 4 joints are positioned to form the corners of a square. The distances between the junction locations 4 in each group is shorter than the distance between the adjacent groups 5. The distance between the junction locations within the group 5 with them is determined as the shortest distance between mutually adjacent junction locations . Correspondingly, the distance between the groups 5 is determined as the closest distance between mutually adjacent groups 5. The distances are measured from the edges of the joint locations 4 in both cases. The shortest distance X between adjacent groups, is measured between the closest junction locations 4 together in respective groups 5, is suitably 2-6 mm, and the largest distance Y between mutually adjacent junction locations 4 in the groups it is suitably 0.5-1 mm. The first mentioned distance X is at least about twice as large as the last mentioned distance Y. The ratio x / y between the distances X and Y is from 2/1 to 12/1. As the molten or softened thermoplastic material in the laminate does not cools, it will solidify and function as a bonding agent for the laminate. In addition to this joining of the two sheets 2, 3, the porous structure in the sheets 2, 3 remains compact or dense. The most pronounced is the densification at the actual joint locations 4. The particular placement of the joint locations 4 means that the joined laminate 1 will exhibit square areas 6 which are limited by the joint locations 4 in the groups 5 and will be more dense in those regions than in the regions 7 between the groups 5. The sheets forming the laminate 1 shown in figures 1 and 3 are joined together by forming penetration holes 8 in the top cover 2 at the joint locations 4. In addition, the material located within and near the joint locations 4 is more densified and has thinner capillaries than the material surrounding. This improves the capacity in the regions where the joints are located to allow the liquid to pass from the top cover 2 to the liquid transfer sheet 3. Although the laminate 1 is shown to include penetration holes 8 in the first sheet 2, the top cover 2, it will be understood that this is not a necessary feature of the invention. Therefore, the invention also includes lamination in which the bonding locations 4 exhibit a surface of a nature more or less impervious to liquid, and a laminate that includes penetration orifices and liquid impervious joints. The binding locations of low liquid permeability or liquid impermeability are obtained for example, when the laminate includes a high proportion of thermoplastic material that is fused and then allowed to solidify on a film-like surface. Although the actual 4 union locations are almost practically impermeable to a liquid, the compacted fiber structure created around the joint locations 4 in conjunction with the joint compression that takes place closer to each joint location 4 still has a very high liquid transfer capacity. In addition, the densified regions 6 inward of the junction locations 4 in each group of the junction locations form zones of high liquid transfer capacity. Because the distance between the union locations 4 in each group í > it is relatively small, preferably from 0.5 mm to 1 mm, The compression of the material at the joint locations 4 will also affect the area 6 inward of the joint locations 4 so that a denser structure is obtained. Therefore, the size of the capillaries in the densified region 6 delimited by the joint locations 4 is, on average, smaller than the size of the capillaries in those regions of the laminate 1 that are between the groups 5 of the joint locations 4. The laminate 1 will therefore have a relatively high liquid transfer capacity in relation to the surface area (< combined of the bonding locations 4. The combined surface area 5 combined will preferably be from 3 to 11% of the total surface area.The surprisingly suitable liquid transport and liquid transfer capacity of the laminate are not due solely to joint locations 4 themselves and to the regions or areas immediately adjacent to these locations and exhibit a high liquid transfer capacity, but it is also due to those areas or regions located between the locations of a 4 in a group 5 that also contribute to the improved liquid transfer capacity. The invention therefore allows the regions of greatest capacity and with this the improved liquid transport capacity, are created while still obtaining a high volume laminate 1 which is soft and foldable. This results in a drier surface against the wearer's skin and in a product having a lower pH, due to the absorbent body which includes a superabsorbent partially neutralized. It also reduces the risk of undesirable side effects, such as odors and skin irritation. All the use of the products that are applied to the skin can lead to undesirable side effects. Those side effects may be caused by occlusion, the presence of moisture, and factors of a mechanical, microbial and enzymatic nature. Such use can also cause skin irritation, primary or secondary infections of the skin and generate undesirable odors. An increment (• pH is a normal occurrence when absorbent products are used against the skin, however, several undesirable side effects can occur as a result of or in conjunction with an increase in pH. it is shown that it has a relation to a pH surface of the skin, it is an example of such undesirable side effects 10 Another example of undesirable side effects is that of certain bacteria such as Proteus, are capable of metabolizing substances in the urine and other body fluids and give rise to odorous substances, such as ammonia and amines, which cause an increase in pH.

The balance of many odorous substances is displaced to generate more volatile components and therefore a greater amount of odors at low pH levels. An environment like that found in an absorbent article in which moisture, nutrients and heat, among other things, are available, also favor the growth of microorganisms. High numbers of bacteria constitute a risk of infection. A high bacterial presence also represents a greater risk of annoying odors being produced by the different substances that are formed as a result of biological degradation or chemistry of the body fluid components, such as components of urine and menstrual fluid. The activity of the microorganisms depends to a great extent on the pH and decreases with the descending values of the pH. (• The use of a partially superabsorbent material neutralized in the absorbent structure according to the invention results in a decrease in pH. The aforementioned undesirable side effects thus reduce in the case of an absorbent structure of the invention. The partially neutralized superabsorbent material is used in absorbent articles described in the patent application Swedish SE 9702298-2. A reduced pH value is obtained as a result of the in? Lusion of the material of a pH control substance in the form of a partially neutralized superabsorbent material. It has been found that an inhibitory effect of The pronounced growth is obtained with respect to the undesirable strains of microorganisms and the occurrence of undesirable side effects that may result from the use of the article are reduced, when the pH of the absorbent article is in the range of 3.5-4.9 or preferably 4.1-4.7 after the wetting the article. A partially neutralized and suitable superabsorbent material may be comprised of an entangled polyacrylate of the type described in the European patent specification EP 0 391 108, Casella AG. The superabsorbent materials different from the material mentioned above that have corresponding properties can used alternatively Examples of relationships between the degrees of neutralization and the pH values of the superabsorbent material will be evident from the following text. The information listed below has been taken from the Swedish patent application SE 9702298-2.

Degree of neutralization% PH 18 4.0 25 4.3 30 4.5 35 4.7 45 5.0 60 5.5 It will be evident from the table that the degree of neutralization should be less than normally 45% and preferably less than 35%. The degree of neutralization, however, should preferably be greater than about 20%. These degrees of neutralization are also appropriate with respect to the present invention. In those degrees of neutralization used in the absorbent structure of an absorbent article according to the invention, an acidic environment is obtained after the structure has been moistened when used against the skin, thereby inhibiting the growth of microorganisms and preventing odors unpleasant irritation of the skin. After moistening, the absorbent body of the absorbent article of the invention will have a pH in the range 3.5-4.9, preferably 4.1-4-7. Another benefit achieved by the invention is that occurrence of unpleasant odors and injuries to the skin as a result of the use of the absorbent article against the skin are avoided. The effect of growth inhibition is based on the fact that many microorganisms have an activity that is highly dependent on pH and decreases with decreasing pH values. Enzymes such as lipases and protease also have an activity that is strongly dependent on pH and that decreases with decreasing pH value. Therefore, a reduction in pH results in a reduction in the activity of the majority of the microorganisms and also a reduction in the enzymatic activity provided with this a reduction in the negative effects on the skin. The following examples are taken from SE 9702298-2 to illustrate the effect of the absorbent articles having an absorbent body including a partially neutralized superabsorbent material. The absorbent body also includes a cellulose pulp having a pH of 2.5-8.5. An absorbent body containing absorbent material and an absorbed liquid is by nature a heterogeneous system from a pH aspect. The system can include material superabsorbent, fibers and liquid that contains various types of ions. In order to obtain reproducible pH values, it is necessary to take measurements at several places in the sample body and calculate the value (• average of said measurements.

DESCRIBING THE EXAMPLES The following examples are intended to more closely illustrate the effect on absorbent articles having an absorbent body including a combination of partially neutralized superabsorbent material and cellulose pulp having a pH of 2.5-8-5. Comparisons are made with conventional material of a corresponding type.

TEST LIQUIDS: Test liquid 1 0.9% sodium chloride solution.

Test lumen 2 20 Synthetic urine according to the description of, among others, EP 0565606, such as urine obtained from Jayco Pharmaceuticals Co., Pennsylvania. The urine has a composition of 2 g / l KCl; 2 g / 1 Na2SO4; 0.85 g / 1 (NH4) H2PO4; 0.15 g / 1 (NH4) H2PO4; 0.19 g / l CaCl2 and 0.23 g / 1 MgCl2. This mixture has a pH c'e 6.0-6.4.

Test liquid 3 Synthetic urine containing the following substances: KCl, NaCl, MgSO4, KH2POI4, Na2HPO, NH2CONH2. This mixture has a pH of 6.0-6.5.

Test liquid 4 Sterile synthetic urine to which the microorganism growth medium has been added. Synthetic urine includes cations and anions, monovalent and bivalent and urea and was prepared according to the instructions given in Geigy, Scientific Tables, Vol. 2, 8ava. Ed., 1981, p. 53. The growth medium of the microorganism was based on data related to the Hook medium and the FSA medium for enterobacteria. This mixture had a pH of 6.6 TEST METHODS: Method 1. The manufacture of absorbent bodies for testing purposes The absorbent bodies were produced with the help of slightly modified test body formers in accordance with SCAN C 33:80. The lint pulp and superabsorbent material of the desired type were weighed and a uniform mixture of lint pulp and superabsorbent material was then passed in an air stream at a supression of approximately 85 mbar through a pipe having a diameter of 5 cm. and provided with a metallic net transported in the inferior one and a thin fabric placed over said network. The mixture of lint pulp and superabsorbent material was collected in the fabric placed on the metal net and subsequently the absorbent body was formed. The absorbent body was weighed and then compressed to a volume density of 6-12 cm3 / g. A number of absorbent bodies designated as reference product 1, reference product 2, test product 1, test product 2, test product 3, test product 4, and so on, of different compositions were then produced as described then. The amount of absorbent material in the single core and double core absorbent bodies was adapted so that the individual core bodies and the double core bodies had approximately the same absorption capacity.

Method 2. pH measurement in cellulose pulp The pH of the cellulose pulp in the different test products was measured by determining the pH of a water extract from the pulp according to SCAN P 14:65 1.0 g of air-dried cellulose pulp that was placed in a 100 ml glass laboratory beaker and 20 ml of distilled water were added. After stirring the mixture, an additional 50 ml of distilled water was added and the mixture was stirred for approximately 30 s. It was left to rest for 1 hour. The liquid was then poured and the pH was measured with a glass electrode at 20-30 ° C. They made two samples and the average value was calculated.

Method 3. pH measurement of an absorbent body An absorbent body having a diameter of approximately 50 mm was produced according to method 1. A certain amount of test liquid 1, 2 and 3 was added, 10 ml to an individual core absorbent body and 20 ml to a double core absorbent body. The absorbent body was allowed to expand for 30 minutes after which the pH of the absorbent body was measured with the aid of a surface electrode, Metrohm flat-bottom pH meter Beckman 012 or 072. Parallel measurements were performed in at least two different absorbent bodies. The pH was measured at 10 points on each absorbent body and the mean value was calculated.

Method 4, measurement of the inhibition of bacteria in absorbent bodies Absorbent bodies were prepared according to method 1. The absorbent bodies of single core and double core were prepared. Test liquid 4 was prepared. The respective bacterial suspensions of Escherichia coli (E.c.), Proteus mirabílis (P.m.), Enterococcus faecalis (E.F.) were cultured in nutrient broth at 30 ° C overnight. The graft cultures were diluted and the bacteria content was calculated. The cultures were mixed in different proportions so that the final culture mixture contained approximately 104 organisms per ml of test liquid 4. The test liquid 4 was poured into a jar of sterile sputum measuring 70.5 x 52 mm and having a volume of 100 ml and the absorbent body was placed inverted in the jar and allowed to absorb the liquid for a period of 5 minutes, after which the jar was turned over and incubated at 35 ° C for 0.6 and 12 hours respectively and the value of the bacteria in the absorbent body was subsequently determined. TGE agar was the nutrient used in measuring the total number of bacteria present and Drigalski agar and Slanetz Bartley agar were used for specific measurements of Escherichia coli and Proteus mirabilis and Enterococcus faecalis respectively.

Method 5, measurement of ammonia content Individual core absorbent bodies were prepared according to method 1. Test liquid and microorganisms were added according to method 5, after which the jars were incubated at 35 ° C during 0.3, 6 and 12 hours respectively and then the samples were taken from the jars with the help of a manual pump and Dráger tubes. The ammonia content was read as an indication of color along a graduated scale either in parts per million as a percentage by volume.

Method 6. pH measurement of skin surface Sample products were produced by coating the back side of the absorbent bodies according to the reference 3 and test 4 respectively with a polyethylene coating having a weight per unit of air of approximately 25 g / np2 and the front side of said bodies with no coating.

("Polypropylene fabric having a weight per unit air of approximately 20 g / m2.) Test liquid 3 was applied to the front side of the test product and absorbed therein. The resulting test products were placed in the test products. The forearms of the people in the test were allowed to rest there for 24 hours, the procedure was repeated twice.

The surface of the skin was measured at the contact site before applying the test products and after 24, 48 and 72 hours using a pH meter from the Courage + Hhazaka skin that had a Mettler-Toledo glass electrode. flat background 403/120.

PROOF PRODUCTS Reference product 1: An individual core absorbent body having the total weight of 1 gram produced from superabsorbent material conventional and a conventional chemithermomechanical cellulose pulp in a ratio of 15/85 weight percent.

Test Product 1: An individual core absorbent body having a total weight of 1 gram and produced from superabsorbent material partially neutralized having a pH = 1 to 4.2 according to the invention and a chemithermomechanical cellulose pulp having a pH of 5.8 at a ratio of 15/85% by weight. (• Test Product 2: An individual core absorbent body having a total weight of 1 gram and produced from a partially neutralized superabsorbent material having a pH equal to 4.2 according to the invention and a cellulose pulp chemithermomechanical having a pH = 3.7 in a ratio of 15/85% by weight.

Reference product 2: A two-core absorbent body. The upper core (UC) 15 has a total weight of 1.2 grams and is produced from a conventional superabsorbent material and a chemithermomechanical pulp in a ratio of 12/88%. The lower core (LC) has a total weight of 1.1 grams and is produced from a conventional superabsorbent material and a conventional chemical pulp in a ratio of 12/88% by weight.

Test product 3: A two-core absorbent body. The upper core (UC) had a total weight of 1.3 grams and was produced from a material partially neutralized superabsorbent having a pH = 4.5 of according to the invention, and a chemithermomechanical pulp having a pH of 5.8 in a ratio of 15/85%. The lower core (LC) has a total weight of 1.2 grams was produced from a partially neutralized superabsorbent material having a pH of 4.5 according to the invention and a chemical pulp having a pH = 6.2, in a ratio of 15. / 85% by weight.

Reference Product 3: An individual core absorbent body having a total weight of 1 gram was produced from partially neutralized superabsorbent material and a conventional chemical cellulose pulp at a ratio of 15/85% by weight.

Test Product 4: An individual core absorbent body having a total weight of 1 gram was produced from partially neutralized superabsorbent material having a pH = 4.2 according to the invention and a conventional chemical cellulose pulp, in a ratio of 15/85% by weight.

Reference product 4: An individual core absorbent body having a total weight of 1 gram was produced from conventional superabsorbent material and a chemithermomechanical cellulose pulp having a pH = 6.7, in a ratio of 15/85% by weight .

Test Product 5: An individual core absorbent body having a total weight of 1 gram and produced from partially neutralized superabsorbent material having a pH = 4. 2 according to the invention, and a chemo-tremomechanical pulp having a pH = 6.7 in a ratio of 15/85% by weight.

Test product 6: A two-core absorbent body. The upper core (UC) has a total weight of 1.3 grams and is produced from a partially neutralized superabsorbent matericil having a pH = 4.6 according to the invention and a chemithermomechanical pulp having a pH = 5.8, in a ratio of 15/85%. The lower core (LC) which has a total weight of 1.2 grams and is produced from partially neutralized superabsorbent material having a pH = 4.6 according to the invention and a chemical pulp having a pH = 6.3 at a ratio of 15. / 85% by weight.

TEST RESULTS: Example 1 As will be apparent from Table 1, the growth of microorganisms was adequate in a conventional single-core absorbent body according to reference product 1. The growth of bacteria was measured according to the method 4.

Table 1: Time Esherichia Proteus Enterococcus coli mirabilis faecalis 0 h 3.3 3.1 3.7 6 h 7.0 6.4 7.1 12 h 9.2 9.1 8.3 Example 2 It will be apparent from Table 2 that inhibition of growth of microorganisms was adequate in an individual core absorbent body according to test product 1. Inhibition of bacteria was measured according to method 4.

Table 2: Esherichia Proteus Enterococcus coli mirabilis faecalis 0 h 3.2 3.3 3.4 6 h 5.5 3.2 4.8 12 h 7.3 4.0 6.1 Example 3 It will be evident from the table that the inhibition of the growth of microorganisms was adequate in a body individual core absorbent according to the test product 2. The measurements were carried out according to method 4. II 'Table 3: Time Esh erich ia Protei us Enterococcus coli mirab ilis faecalis 0 h 3.4 3.3 3.5 10 6 h 3.2 2.6 3.6 12 h 2.8 2.0 3.5 Example 4 It will be evident from table 4 that the growth of microorganisms was suitable in a conventional two-core absorbent body according to the reference product 2. The measurements were carried out according to method 4. Table 4: 20 Time Eshi erichia Proteus Enterococcus coli mira bile faeca ilis UC * LC ** UC * LC ** UC * LC ** 0 h 3.4 3.4 3.4 3.4 3.4 3.4 6 h 6.8 7.0 6.6 6.7 6.7 6.2 25 12 h 9.0 9.0 9.1 9.0 8.0 7.8.

UC * = upper core LC ** = lower core Example 5 It will be apparent from Table 5 that inhibition of the growth of microorganisms was adequate in a two-core absorbent body according to test product 3. The measurements were carried out according to method 4.

Table 5 Time Esherichia Proteus Enterococcus coli mirabilis faecalis UC * LC. ** UC * LC * 'UC * LC ** 0 h 3 3.4 3.4 3.4 3.4 3.4 6 h 5.1 5.6 3.3 4.2 4.4 4.5 12 h 7.3 7.4 4.0 4.0 5.9 4.8 UC * = upper core LC ** = lower core Example 6 It will be apparent from Figure 9 that ammonia production was retarded in a way in an individual core absorbent body according to the test product 5, as compared to the conventional single core absorbent body according to the product reference 4. The measurements were carried out according to method 5.

Example 7 As will be apparent from Figure 10, after having used a sample product that included absorbent body according to test product 4 for a given period, the pH of the skin set at a lower level than in the case of a corresponding sample product containing a conventional superabsorbent material according to reference product 3, after adding test 3. The measurements were carried out according to method 6.

Example 8 As will be apparent from Table 6, the pH measured in an individual core absorbent body according to test product 1 is within the active pH range of 3.5-4.9 after the test liquid has been added. The measurements were carried out according to method 3.

Table 6 Fluid Liquid Liquid Test 1 test 2 test 3 PH 4.29 4.42 4.54 Example 9 As will be seen from table 7, after adding the test liquid the pH measured in a double core absorbent body according to the test product 6 is within the active test range of 3.5-4.9. The measurements were carried out according to method 3.

Table 7 Liquid Liquid Liquid Test 1 test 2 test 3 pH UC * 4.72 4.83 4.80 pH LC * 1 4.75 4.73 4.73 UC * = upper core ** LC = lower core Therefore a low pH has a better effect with respect to the inhibition of the growth of microorganisms. When a partially neutralized superabsorbent material is used together with the laminate described above in an absorbent article, additional benefits are obtained with respect to skin irritation and odor. The described laminate also has a drier surface for the user's skin, which also has a good effect with respect to skin irritation. As will be clearly seen from Figure 2 for example, the welding pattern in the laminate of the article of the invention has a three-dimensional structure. This means that less material will be located directly against the skin of the user, thereby providing a degree of freshness between the material of the surface and the skin of the user. This reduces the risk of skin irritation caused, for example, by irritation and / or because the skin is wetted as a result of the occlusion (heat) and / or because some liquid remains on the upper cover in contact with the skin. skin of the user after a first moistening. Next, additional embodiments of a laminate 1 used according to the invention are described. Figure 3 illustrates a joining pattern in a laminate 1 whose uppermost sheet or cover is located next to the user of an absorbent article of the invention. The binding pattern consists of diamond-shaped binding sites 4 placed in 5 'groups, with 4 binding sites 4 in each 5' group. The binding pattern shown in Figure 3 also includes top group formations 5"comprising 4 groups 5 'each having 4 attachment locations 4. Thus,, three different types of regions 6, 7 and 9 that have mutually different densities in the matercan be identified in the joint pattern shown in Figure 3. The densest materstructure that has the smallest pore size is found in the groups 5 'comprising 4 attachment locations 4. The less dense regions 7, which have a slightly larger pore size, are found in the upper group formations 5"comprising groups 5' each having 4 attachment locations 4. .

The regions 9 of the lowest density are between the upper group 5"formations, and between the upper group 5" and the single 5 'groups of the 4 union locations placed between the upper group 5"formations. In the case of the embodiment of Figure 4, the joint locations 4 are in the form of small hyphen-like joints (1- 1.5 mm) placed in generally parallel strip configurations 5 that are mutually separated by a distance that is greater than the distance between the joint locations 4 in said strips.

Located between the joint locations 4 in respective strips are the densified members 6 which have a pore size smaller than the regions 7 located between said lines or strips 5. Figures 5-7 illustrate further conceivable joining patterns. The union pattern shown in figure 5 includes pairs generally parallel wavy lines of union 4 where the distance between the lines 4 of each pair 5 exceeds the distance between the pairs 5 of the lines of union 4. Therefore, it is obtained with the joint pattern shown in Figure 5 a laminate that includes the densified liquid transfer regions between the lines of junction 4 of each pair and smooth, ventilated, bulky separation regions 7 between the joint pairs 5. An advantage that is achieved by placing the joint locations 4 in the form of strips or lines is that a superior material that includes said union pattern will lead the liquid along the strips or lines, and will counteract the dispersion of the liquid perpendicular to said strips or lines. This facility can be advantageously used to reduce the risk of edge spillage in the absorbent articles. Figure 6 illustrates a pattern including groups 5 each consisting of two joint locations 4 in the form of concentric rings delimiting the densified regions 6, while the less dense regions 7 lie outside the outer ring of the regions. ring-shaped junction locations 4. Figure 7 shows a pattern comprising parallel, short, 4-like lines, in pairs at a given separation distance to form the densified regions 6 between dashed lines 4 in each pair 5 and the less dense regions between the pairs of hyphen-like lines 4. Figure 8 illustrates an embodiment of an absorbent article of the invention in the form of an incontinence guard or towel 10 including a laminate 1 having a sheet upper permeable 2 and a liquid permeable liquid transfer sheet 3. The article also includes a liquid impermeable back sheet 11 and a body or cushion The absorbent bag 12 is enclosed between the upper cover 2 and the rear cover 11. The upper cover 12 and the rear cover 11 have a slightly greater extension than the absorbent body 12 and protrude slightly beyond the edges of said absorbent body. The upper cover 12 and the rear cover 11 are joined along their outwardly projecting portions 13, for example by glue or welding with heat or ultrasound. The absorbent body 12 can be of any conventional type. Examples of typical absorption material are cellulose fluff pulp, tissue paper, highly absorbent polymers (so-called superabsorbents) absorbent foam, absorbent nonwoven materials and the like. It is also usual to build absorbent bodies with layers of different materials having different properties with respect to liquid acquisition capacity, liquid dispersion capacity and storage capacity. Such constructions are well known to those skilled in the art and need not be described in detail herein. The thin absorbent bodies or normal pads currently in, for example, infant diapers and incontinence protector are frequently constituted of a mixed structure or in compressed layers of cellulose pulp and superabsorbent material. According to the invention, the absorbent material is combined with the partially neutralized superabsorbent material in an absorbent body. As mentioned before, this results in an absorbent article having a lower pH against the skin in use and having a dry surface for the skin. The irritation of the skin and the formation of gases with a bad smell are counteracted by several factors, such as the inhibited growth of microorganisms, less skin irritation and less moisture in contact with the skin. The incontinence protector or towel 10 has a hourglass configuration which includes wide outer portions 15 and 16 and a narrower crotch portion 17 located between said end portions 15, 16. The crotch portion 15 is that part of the incontinence guard that is intended to be located in the vicinity of the crotch portion 15. between the user's thighs in use and which functions as an acquisition surface for the discharged body fluid As mentioned before, between the liquid permeable top cover 2 and the absorbent body 11 is located an elastic liquid transfer sheet and porous 3, for example, wadding fiber, a layer of porous foam or a layer of one of the aforementioned materials that are suitable for the second sheet in the laminating shown in Figures 1 and 2. The liquid transfer sheet 3 receives the liquid that passes through of the upper cover 2. The urinary discharge often involves ia discharge of relatively large volumes of the liquid during a short period. It is therefore important that contact is achieved between the liquid-permeable top cover and the sheet "transfer of liquid that is located in 3 is such that the liquid can penetrate quickly inside the sheet of Liquid transfer 3. Because the liquid transfer sheet has a higher bulk density and a thickness preferably of 0.5-4 mm, sheet 3 is able to function as a temporary liquid container before it is absorbed subsequently within the absorbent body 11. In the embodiment shown, the liquid transfer sheet 3 it is slightly narrower than the absorbent body 11 although it extends along the entire length of the incontinence guard. An advantage with this design is that it allows a saving in consumption " # of material. Naturally, additional savings can be achieved, making the liquid transfer sheet 3 shorter than the length of the incontinence guard. For example, a conceivable alternative in this regard is to place the liquid transfer sheet 3 only in the crotch portion 17 of the incontinence guard, since the largest of the body fluid or fluid will be absorbed by the incontinence guard which can be expected to be discharged into this part of the shield 17. Those liquid transfer sheets which are normally used are often very porous and with this exhibit a relatively large effective average size, which is often greater than the effective average pore size of the conventional liquid permeable top sheet material. The effective average pore size of a fiber material can be measured according to a method described in EP-A-0 470 392. Since the liquid strives to pass from the thickest capillaries towards the finer capillaries and not vice versa as a result of capillary action, the liquid tends to remain in the fiber network of the external material outside instead of being drained by the more porous liquid transfer sheet. As a result, there is a risk that the liquid will travel on the surface of the sheet external or top cover, and spill origin. The liquid that It remains in the fiber structure of the upper cover will also cause the surface of said cover to feel moistened and thereby cause discomfort to the user. By attaching the liquid-permeable top cover 2 to the liquid transfer sheet 3 as described with reference to the sheet 1 shown in Figures 1 and 2, the liquid transfer sheet 3 will be compressed at the joint locations 4. Therefore, the liquid transfer sheet 3 has a density gradient where the density increases toward the respective binding locations 4. The liquid transfer sheet 3 will therefore be presented in a region around the bonding locations. with a pore size gradient and an area in which the effective average pore size is smaller than the average pore size of the liquid-permeable top cover 2. By grouping the bonding locations 4 according to the present invention, it is possible to increase that part of the surface of the sheet 1 in which the average pore size of the liquid transfer sheet 3 is smaller than the average pore size of the upper cover permeable to the liquid 2. This allows the Liquid transfer cover 3 drains the liquid away from the top cover 2 effectively. Because the liquid drained away from the top cover 2 in the region surrounding the respective junction locations 4 and in the denser regions 6 which are located between the junction locations 4 in each location group of junction 5, those regions will have a liquid deficit so that they achieve an equalization of the liquid with the surrounding regions. The top cover 2 will contain less liquid in total and consequently will feel drier against the skin than would otherwise be the case. Since a lower pH is obtained when the article is used, as a result of the partially neutralized superabsorbent material present in the absorbent body, the risk of, for example, skin irritation is greatly reduced. By placing the bonding locations 4 into groups 5 with unbonded densified regions 6 between the bonding locations 4, it is possible to achieve a highly effective liquid transport from the top cover, permeable to the liquid 2 towards the liquid transfer cover 3 , with relatively few unions. In addition the unbonded regions 7 are left between the groups 5 with what will be a wavy structure or "with protuberances" for the surface of the incontinence guard 10 which is located next to the user during use. These unattached regions 7 between the joining groups 5 are bulky and smooth, causing the laminate 1 to be ventilated and comfortable for use, also an effective distancing of said surface from the user's skin is made so that the skin will remain dry even when the laminate is moistened. In order to ensure that an effective liquid transfer is obtained between the liquid transfer sheet 3 and the absorbent body 11, the absorbent body will preferably have an greater affinity to the liquid than the liquid transfer sheet 3. This can be achieved, for example, by making the liquid transfer sheet 3 less hydrophilic than the absorbent body 11 and / or giving (• to the absorbent body 11 a finer capillary structure than the liquid transfer sheet 3. It will be understood that the invention is not restricted to the described illustrative embodiments thereof and that variants and modifications are conceivable within the scope of the following claims 10 By the word "comprises" as used herein, it is implied that it is included, but not limited to. fifteen twenty

Claims (10)

1. An absorbent article, such as a diaper, sanitary napkin, incontinence protector, wound dressing or the like comprising an absorbent body enclosed between a liquid impermeable backing and a laminate of material in the form of a sheet of permeable fibrous material. to the liquid that forms a top cover and a sheet of porous and elastic liquid-permeable material that forms a liquid transfer sheet 10 which is located next to the absorbent body, wherein the laminate has a flat extension and a direction of thickness perpendicular to the planar extension, wherein at least one of the sheets includes thermoplastic material, and wherein the two sheets are attached to each other. through bonding locations on the laminate within the Wherein the thermoplastic material is caused to soften or melt at least partially and thus bind the two sheets, characterized in that the absorbent body includes a partially neutralized superabsorbent material; and in which the joining regions and the sheets of the laminate extend in the direction of 20 thickness of said laminate through the top cover and at least partially through the liquid transfer sheet.

2. An absorbent article according to claim 1, characterized in that the regions of the laminate join are placed in two or more groups where each group includes at least 25 minus two union locations, where the relative distance more Large between two mutually adjacent joint locations in a given group is less than the shortest distance between a group and its nearest adjacent group, where the laminate includes between the joining locations in each joint group first unbonded laminate regions which have a higher density than second unbonded laminate regions located between respective linking groups.

3. An absorbent article in accordance with the claim 1 or 2, characterized in that the superabsorbent material has a degree of neutralization so that the pH in the absorbent body of the article when it is wetted will be in the range of 3.5-4.9, preferably 4.1-4.7.

4. An absorbent article in accordance with the claim 2 or 3, characterized in that the joining locations of the laminate include point connections, linear joints, rectangular joints or circular joints. An absorbent article according to any one of the preceding claims, characterized in that the upper cover has penetration holes within the joint locations. 6. An absorbent article according to any of the preceding claims, characterized in that the upper cover is comprised of a non-woven material. 7. An absorbent article according to any of the preceding claims, characterized in that the cover The upper part is comprised of a thermobonded, carded nonwoven material. An absorbent article according to any of the preceding claims, characterized in that the liquid transfer sheet is a sheet of fiber batt having a thickness of 0.5-4 mm. An absorbent article according to any one of the preceding claims, characterized in that the shortest distance X between two mutually adjacent groups of bonding locations is at least twice the size of the largest distance Y between two mutually bonding locations adjacent in respective groups. 10. An absorbent article according to claim 9, characterized in that the ratio of x / y between the distances x and y is from 2/1 to 12/1. 1 . An absorbent article according to claim 9 or 10, characterized in that x is 2-6 mm and y is 0.5-1 mm.