RU2417106C2 - Absorbent product - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to an absorbent product, such as a diaper, absorbent pull-up, sanitary towels, or incontinence panty, with a vapour-permeable protective layer, comprising a moisture permeable coating layer facing a user when in use, a water-proof, however vapour-permeable protective layer facing an opposite side from a user when in use, and an absorbent core between the coating layer and protective layer; said product has a longitudinal direction (2), a transversal direction (3), two substantially longitudinal lateral borders (4, 5), one substantially transversal front border (7), one substantially transversal back border (8), one substantially longitudinal middle line (6), a front portion (9) and a back portion (10) from each side from the substantially longitudinal central line (11); the substantially longitudinal middle line (6) and central line (11) are crossed with each other in a cross point (12) where the presented absorbent product contains at least one monovalent salt of the X⁺Y^- form in the amount 1-75 wt % at core weight.

EFFECT: product reduces the risk of infection and unpleasant odours due to limited growth and activity of undesired microorganisms.

15 cl, 8 dwg, 5 ex

Description

Technical field

The present invention relates to an absorbent article, such as a diaper, absorbent underpants, a sanitary napkin, or an incontinence product with a vapor-permeable protective layer containing at least one monovalent salt of the form X ⁺ Y ^- .

State of the art

As a rule, microorganisms appear in absorbent products during use. Microorganisms are introduced into absorbent products by body fluids, such as urine or menstrual fluid, or in contact with skin. The growth of bacteria in absorbent products can be significant during the time at which these products are in use. With a large number of microorganisms, there is an increased risk of urinary tract infection and skin irritation, and in addition, the presence of bacteria is largely associated with the presence of odors.

Bacteria are often bacteria that are commonly found in an individual. As a rule, there is an ecological balance between the various microorganisms located on the skin and mucous membranes, and normal microbial flora is important to prevent the possibility of propagation of unwanted microorganisms. Sometimes this balance can be disturbed, so that potential pathogens can strengthen, grow, and then lead to infection, for example, due to the use of drugs, insufficient hygiene, poor immune defense, excessive hygiene, skin changes, changes in the mucous membranes and prolonged use of absorbent products.

Using absorbent products over a long period of time without regular replacement or with poor hygiene in combination with weakened immune defenses can lead to the growth and spread of microorganisms. In addition, tight-fitting clothing and underwear can increase the risk of microbial growth. With an increased amount of unwanted microorganisms in an individual or in an absorbent article, there is an increased risk of microbial imbalance and infections.

A natural component of the prevention of genitourinary infections is improved personal hygiene. However, it would be impractical to wash the genital area with concentrated soap or bactericidal agents, and therefore it may be difficult for an individual to reduce the risk of infection to an appropriate level using conventional agents. Excessively thorough washing with concentrated detergents also violates the normal flora of the desired bacteria, which contributes to our protection against unwanted bacteria. In addition, it is sometimes difficult to change absorbent products. Long-term use can also increase the risk of infections if microorganisms continue to multiply within the product. Closed space and temperature favor the growth of microorganisms in the product and on the skin and mucous membranes of the user.

Emerging infections have traditionally been treated with conventional antibiotics. However, repeated antibiotic treatment can lead to the development of resistant bacterial strains, which can create difficulties for further treatment of infections. Another problem associated with antibiotic treatment is that many individuals are hypersensitive to antibiotics. In addition, antibiotics can be harmful to the skin and the vaginal flora in women, leading to the fact that this infection can reappear. The disadvantage of using antibiotics can also be a violation and destruction of bacteria of normal flora.

Description of the Related Art

Previous attempts have been aimed at reducing the growth of microorganisms and bacteria in absorbent products by introducing bacteriostatic agents and lowering the pH.

It was also proposed to use lactic acid bacteria due to their inhibitory effect on pathogenic microorganisms. It has been shown that the use of lactic acid bacteria reduces the incidence of infections both on the skin and on the mucous membranes.

WO 2004/105822 describes the use of absorbent products with the addition of lactic acid producing bacteria. Bacterial cells are transferred to the user's skin and reduce the risk of microbial infection in the urogenital area of the user and on the skin of the user.

EP 1032434 B1 describes an absorbent article containing lactic acid bacteria. Bacteria are placed in such a way as to be transferred to the user's skin in order to worsen the conditions for unwanted microorganisms.

EP 510619 provides a number of agents that prevent the growth of bacteria, for example chlorhexidine, quaternary ammonium compounds, copper salts, chelating agents, parabens, chitin and pH buffers.

US 2004/0180093 provides several examples of antimicrobial agents, for example, silver compounds, copper compounds and zinc compounds contained in the polymer composition. Ions of silver, copper and zinc have antibacterial properties.

No. 4,883,478 describes the preparation of an absorbent composition containing a saccharide. The monosaccharide and / or disaccharide is mixed with a superabsorbent to form a homogeneous paste. This absorbent material can be used, for example, in a dressing. The composition has particular advantages for treating wounds, since sugar favors wound healing. In addition, sugar reduces the activity of water and, thus, prevents the growth of microorganisms. However, sugar must be concentrated in order to act as a preservative. When diluted with urine, for example, it acts as a nutrient.

A decrease in pH is also able to inhibit the growth / activity of bacteria. This can be done, for example, using acidic superabsorbent polymers, acidic cellulose, adding acids, and so on.

In some cases, absorbent articles contain moisture-proof but vapor-permeable protective layers. Such protective layers allow gases, such as air and water vapor, to pass through, but are impervious to liquids such as urine and menstrual fluid. Thus, the moisture content on the skin of the user during use is reduced, and the product gives a feeling of a “breathing” product. The fluid may be released directly by the wearer's skin during perspiration, or it may come from a body-selected fluid absorbed by the absorbent core. The decrease in moisture content due to the use of vapor-permeable layers was insufficient to reduce the growth of microorganisms. In addition, unpleasant odors can penetrate the vapor-permeable protective layer.

Lactic acid bacteria in absorbent products need special protection during storage, and a more stable solution is needed to solve this problem. In addition, it would be desirable to find a solution that is environmentally safer and simpler than the solutions mentioned above, known in the prior art.

The undesirable presence of microorganisms in absorbent products, even in low concentrations, in some situations can create conditions for an increase in the number of pathogenic microorganisms. In this case, in absorbent products, the risk of an unpleasant odor increases, since unwanted bacteria often lead to bad odors. Thus, it is necessary to prevent the occurrence and growth of microorganisms in absorbent products. The present invention is directed to solving these problems.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an absorbent article with improved hygienic properties that reduces the risk of infection and unpleasant odor by limiting the growth and activity of undesirable microorganisms.

In accordance with the present invention, this is achieved with an absorbent article, such as a diaper, absorbent panties, a sanitary towel or an incontinence product, with a vapor-permeable protective layer containing at least one monovalent salt of form X ⁺ Y ^- in an amount 1-75 wt.% (% In dry condition) based on the weight of the core.

Brief Description of the Drawings

Figure 1 shows an absorbent article according to the invention in the form of a sanitary napkin for women.

Figure 2 shows an absorbent article according to the invention in the form of an incontinence product intended for men.

Figure 3 shows an absorbent article according to the invention in the form of a sanitary napkin for women with a crotch area.

Figure 4 is a diagram showing the growth of bacteria with the addition of various salts.

The figure 5 presents the amount of ammonia released by adding various salts.

Figure 6 is a graph showing an increasing salt concentration in combination with a vapor-permeable layer.

The figure 7 shows the activity of water in salt solutions of 3% concentration.

The figure 8 shows the activity of water in various salt solutions in Elga-H ₂ O.

Definitions

The inventors have identified two different ways to indicate the salt content in the product. The first is the percentage (%) in the dry state. The percentage (%) in the dry state describes the amount of salt relative to the weight of the core, as shown below. This description is used by the inventors for a dry product, that is, when the product is manufactured, and before it was used.

% dry = Ms / (Ms + Mk)

Ms = mass of added salt

Mk = core mass, e.g. SAP mass + pulp mass + any other core ingredients.

The inventors also want to determine the salt content in the wetted product, namely% in the wetted state. % in the wet state describes the amount of added salt (% in the dry state), which dissolves in the liquid when using the product. The amount of fluid varies depending on the user's situation, and the fluid may be a synthetic test fluid or real fluids secreted by the body, such as urine, menstrual fluid, and so on.

% in the wet state = Ms / Mv

Ms = mass of added salt

Mv = mass of fluid

It is the final salt content and therefore also the activity of water in the wetted product that have a decisive influence on whether bacterial growth is suppressed and hygiene is improved and to what extent. Therefore,% in the wet state is an important parameter to use when describing the action of added salt (% in the dry state). When the product gets wet under the influence of urine, test fluid, and so on, salt is added to its own salt content in these fluids, but this was not included in the calculation of the description of the wet state.

Water activity is a measure of the amount of free water in the system and is a decisive factor for whether microorganisms will grow or not. The definition of water activity is the equation: A _W = P _S / P ₀ , where P _S represents the partial pressure of steam above the sample at a certain temperature, and P ₀ represents the partial pressure of steam above pure water - at the same temperature. Water activity is a dimensionless number in the range from 0 to 1, while the activity of water for pure water is 1, and when the activity of water is 0, free water is absent.

By "pure salt" is meant a content of at least 99% by weight of salt.

A “wet zone” should be understood as an absorbent article zone that receives body fluid. This area is often placed in the center of the absorbent article. If the product has a front part, a back part and a crotch area, the crotch area is often the part of the absorbent product that first receives the fluid secreted by the body. In the case of an incontinence product intended for men, the wet area is the front of the product, which receives urine from the penis, and it is usually the central part of the product. Since the absorbent article may be positioned on the user's body in various ways and this may differ from case to case, reference is also made to the “putative wet area”. This is such a zone that they intend to use as a wet zone when using an absorbent product, and it, of course, is also the central part, as mentioned above.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an absorbent article 1, such as a diaper, absorbent panties, a feminine sanitary pad or an incontinence product with a vapor permeable protective layer, wherein FIG. 1 shows a feminine sanitary napkin including a moisture permeable covering layer which is intended for appeal to the user’s side when used, moisture-proof, but vapor-permeable protective layer, which is designed to turn in the opposite direction from the user consumption, and an absorbent core between the coating layer and the protective layer, wherein said product has a longitudinal direction 2, a transverse direction 3, two essentially longitudinal lateral edges 4, 5, one substantially transverse front edge 7, one, a substantially transverse trailing edge 8, one substantially longitudinal median line 6, a front portion 9 and a rear portion 10 on each side of a substantially transverse center line 11, wherein said middle line 6 and the center line 11 intersect each other friend at intersection 12, this absorbent article comprises at least one monovalent salt form X ⁺ Y ^-. in an amount of 1-75 wt% (% dry) based on the weight of the core.

When a liquid, such as urine, enters an absorbent article, the activity of the water in the absorbent article increases. The presence of salt in the absorbent product will lead to a decrease in the activity of water in the absorbent product when the liquid contacts the salt. This product preferably contains 5-55 wt.% (% In dry condition) of salt based on the weight of the core. The transverse center line 11 is preferably placed at a point located in the middle of the length of the product.

During use, water vapor is forced out through the vapor-permeable / breathable protective layer. The driving force of the displacement of water vapor through the protective layer will undoubtedly be influenced by the environment of the outer part of the back layer. Water vapor inside is easier to move out if the moisture content on the surface of the product is low. The result of the transfer of water vapor through this layer is that the liquid from the absorbent product disappears and the salt remains in the product. This leads to an increase in the concentration of salt in the selected liquid remaining in the product, and this, in turn, leads to a further decrease in the activity of water, which further reduces the growth of bacteria. With reduced bacterial growth, there is the added benefit of suppressing unpleasant odors. Thus, it is possible to eliminate the disadvantage of a vapor-permeable protective layer, which allows the penetration of undesirable odors through it. As steam is removed, a decrease in temperature is also achieved, and the bacteria in this case will grow more slowly. This provides greater comfort and hygiene.

The use of salt in an absorbent product is simple and inexpensive. It is probably also environmentally safer than using other antimicrobial agents, it may be good for the skin and does not lead to the emergence of resistant bacterial strains. Thus, salt reduces the activity of water in a wetted absorbent article. A wet absorbent article should also mean a product that is wetted with excreted matter from the urogenital area or skin of the wearer. Salt coordinates water and thereby reduces the activity of water, which, in turn, inhibits the growth of microbes during use. This is an advantage in the sense of hygiene, since it reduces, for example, the risk of infection. In addition, reduced microbial growth acts as an odor inhibitor, since microorganisms, such as bacteria, for example, produce unpleasant smelling substances, such as ammonia. Using the present invention, the amount of ammonia formed is reduced.

Thus, the combination with a vapor-permeable protective layer is highly effective, since unpleasant odors are not formed in this product to such a large degree, and therefore, fewer unpleasant odors can penetrate the protective layer. This effect increases with decreasing water activity due to the vapor-permeable protective layer.

The amount of free water, water activity is a very important parameter that determines whether bacteria, yeast or mold can grow in various environments. In absorbent products, bacteria mainly grow. Bacteria are a group of microorganisms that is inhibited primarily when water activity decreases.

The protective layer is waterproof but vapor permeable so that water vapor can escape from the product. This is a particular advantage in the case of a large product, since a large surface area is provided for removing steam.

X ^{+ is} selected from among Na ⁺ , K ⁺ , NH ₄ ⁺ , and Y ^{- is} selected from among Cl ^- , C ₂ H ₃ O ₂ ^- and C ₃ H ₅ O ₂ ^- . Monovalent salts can be selected from among NaCl, NaC ₂ H ₃ O ₂ (Na propionate), NaC ₃ H ₅ O ₂ (Na acetate), KCl, KC ₂ H ₃ O ₂ (K propionate), KC ₃ H ₅ O ₂ ( acetate K), NH ₄ Cl, NH ₄ C ₂ H ₃ O ₂ and NH ₄ C ₃ H ₅ O ₂ . These monovalent salts have a good effect on reducing water activity.

Polyvalent ions also work, but polyvalent positively charged ions can have a negative effect on a superabsorbent polymer. Due to ionic bonding, polyvalent positively charged ions are able to interact with the network of a superabsorbent polymer and adversely affect the swelling and, therefore, its absorption in a more negative way than is the case with monovalent salts.

The salt is preferably distributed within the boundaries of the central region in the vicinity of the point of mutual intersection 12. This region is considered to be a wet zone, since it is in this region of the absorbent product, primarily urine and body fluids. Therefore, the salt is preferably distributed in the intended wetting zone.

It is advantageous to place the salt inside and near the area around the wet zone, since the salt must be in contact with the liquid applied to the absorbent article so that it can reduce the activity of water to some extent. The size of the wet zone depends on which absorbent product is required, how much fluid the user emits, and so on. For example, the diaper has a wetting area more than the feminine sanitary napkin. In addition, the wet area for a relatively large incontinence preservative will be larger than for a smaller incontinence preservative. In the wet zone, the salt dissolves in the liquid, and then is transferred with this liquid to other parts of the product.

The region within which the salt is distributed extends at least 1.5 cm from the center line 11 in the longitudinal direction 2 and at least 1.5 cm from the center line 6 in the transverse direction 3. This region extends into both directions from the center line and midline. This is an area that will heavily receive fluid from the user when using this product. In order to make its best use, salt should be placed in this area. Salt can also be placed in the area that covers the entire absorbent article. Then it will not come into contact with the liquid everywhere, but it may be easier to add salt without limiting its location.

According to one aspect of the present invention, the absorbent article is an incontinence product intended for men and is intended to be placed so that it covers the male penis. The incontinence product 21 for men is shown in FIG. 2. As with the absorbent product shown in FIG. 1, this product in the form of an incontinence product intended for men is shown in FIG. 2 with a moisture permeable coating. a layer which is intended to be turned towards the user during use, a moisture-proof protective layer, which is intended to be turned to the opposite side from the user during use, and absorbent core between the coating layer and the protective layer, wherein said product has a longitudinal direction 22, a transverse direction 23, two essentially longitudinal side edges 24, 25, one essentially transverse front edge 27, one essentially transverse rear edge 28, one substantially longitudinal center line 26, front 29 and rear 10 on each side of the substantially transverse center line 11. The center line 6 and center line 11 intersect each other at the intersection 12. In addition, used for incontinence and there are attachments for attaching 218, 219. The salt is distributed inside the central region around the intersection point 212. By analogy with the above, the salt is distributed in the region that extends at least 1.5 cm from the center line 11 in the longitudinal direction 1 and at least 1.5 cm from the midline 6 in the transverse direction 3.

Some absorbent articles also include the crotch area. Such an article is shown in FIG. 1 and FIG. 3. In FIG. 1, the crotch region is not shown, but is marked in FIG. 3. The crotch region 320 is located essentially in the center of the absorbent article. The center line 311 passes through the crotch region 320, the length of which is approximately 7-12 cm. The boundaries of the crotch region in this figure are defined by the front, substantially transverse edge 321 and the rear, substantially transverse edge 322. Absorbent articles with a crotch area are for example, feminine hygiene pads, diapers and incontinence products, but not incontinence products intended for men in whom protection is proposed to be placed so that it essentially to the mother, covered the male penis. The crotch region is a region that receives body fluid and can determine the boundaries of the wet zone, and the salt is preferably distributed in the crotch region of the absorbent article.

In some cases, it is advantageous to wet most of the product. For example, in the case of products capable of absorbing a lot of liquid, it is advisable to make sure that the liquid is distributed over a large area of the product. Then more vapor will pass through the vapor-permeable protective layer. In this case, it may be advantageous for there to be a spreading layer in the absorbent article that distributes the liquid in a direction outside the wet zone. The larger the area within which the liquid spreads, the better the steam will escape through the vapor-permeable protective layer. Therefore, the absorbent article preferably contains a spreading layer.

The distribution layer may include a material whose capillary force is greater than that of the adjacent material from which it will receive fluid. In addition, the spreading layer will be able to quickly absorb liquid due to the capillary effect along the plane of the layer. The distribution layer can be made using wet canvas technology, which produces a layer of dry paper with strength in the wet state. You can also get a spreading layer using airborne technology. In order for the structure obtained by the method of dry canvas forming to have good strength, it is necessary to add binders, such as glue, or fusible fibers. The distribution layer may include one or more different types of cellulosic fibers, non-cellulosic fibers such as wool, silk, or synthetic fibers. Pressed industrial pulp can be used as a non-woven material, for example spunlace, meltblown and so on.

The spreading layer can be placed between the cover layer and the absorbent core, or between the absorbent core and the protective layer. In addition, the distribution strip can be placed inside the absorbent core, for example between two absorbent layers.

However, in the case of some products, the presence of a distribution layer is disadvantageous. This applies, for example, to products designed to absorb a small amount of liquid.

There is no need to distribute the salt within the entire area to which the liquid spreads. The liquid dissolves the salt and then transfers the salt with it.

Salt can also be placed inside the area that covers the entire absorbent article. Then it will not come into contact with the liquid everywhere, but it may be easier to add salt without limiting its position.

Salt can be distributed within the absorbent core. This is where liquid accumulates, and it is important, although not necessary, that the salt comes in contact with the liquid that accumulates in the absorbent core.

Salt can also be distributed at the top of the absorbent core. There it will come into direct contact with the incoming liquid as soon as this liquid passes through the coating layer and any other layers located between the coating layer and the absorbent core. The salt dissolves and then can be transferred further to the absorbent core.

The absorbent article consists of a vapor-permeable protective layer, the vapor permeability of which can be at least 500 g / m ² and 24 hours, measured at 23 ° C by ASTM-6701 MDCON. Such vapor permeability is necessary so that steam can pass through the protective layer in a satisfactory manner and so that it can affect the salt content.

The particle size of the salt can be from 50 to 1500 microns. The salt may be in the form of grains, in which case the diameter of these grains is considered. Since salt grains may have an acute-angled shape and may have an irregular shape, the diameter in question is the average diameter. The salt may also be in the form of particles of some other form, for example, such as flakes. The size of these flakes refers to the long side of the flakes, i.e. the width of the flakes, and this width can be up to 1 cm. The thickness of the flakes can be up to about 5 mm. The size may depend on which product they are placed in, where the salt is placed in the product, and whether rapid or slow dissolution of the salt is required. In the case where the salt is placed in the upper part of the absorbent core, it is more advisable to have relatively small grains. The liquid quickly comes into contact with the salt, and the liquid will pass rather quickly down into the absorbent core and probably will not be in contact with the solid salt for any lengthy period of time. If the salt is placed under the absorbent core, the liquid has already passed through the core and will not be further transferred down the article. Perhaps small grains or particles will be more appropriate if the salt does not come into contact with so much liquid (because the liquid does not pass through the salt), as in the case when the salt is placed inside or at the top of the core. At the same time, large grains can come up, since the liquid and salt can be in contact for a relatively long time.

As already noted, the salt is preferably placed in the central region around the intersection of the center line and the center line, regardless of whether the salt is placed inside or on top or under what layer. In addition, the absorbent core can be divided into several absorbent layers, and salt can be placed between these layers. Moreover, the salt can be placed in one of several layers or in all layers of the absorbent core. Salt may be contained in other layers, such as an airlaid layer, located between the overburden and the absorbent core. In addition, the layer may be located under the absorbent core, between the core and the protective layer where this salt is placed.

Salt can be added as pure salt, i.e. with a purity of 99%. Therefore, it really does not contain any impurities. Salt is an inexpensive component of absorbent products, and in addition, it is easy to apply to the product. Salt can also be applied by spraying a salt solution, or a layer of an absorbent article can be soaked or immersed in a salt solution, and then the salt solution is allowed to evaporate so that the solvent in the water, for example, evaporates from the article. Then the salt will be in the absorbent article in the form of salt crystals. The salt is preferably present in pure form, i.e. with a purity of 99% by weight of salt.

The salt can be used in the form of particles and introduced into the mixture in the process of obtaining an absorbent core. Of course, salt grains can also be introduced in separate layers under the core, inside the core or over the core. In the case where the salt is dissolved in the liquid or suspended in the liquid, this salt solution or a suspension of salt is applied to the absorbent core by spraying. Spraying is followed by a drying step. Advantageously, the salt solution / salt dispersion / salt suspension is already applied by the manufacturer, since the spraying step can be avoided during the preparation of the product. The salt solution can be sprayed onto one or both sides of the absorbent core.

The solvent used for the salt may be water. As a dispersant for the salt, a volatile organic solvent, for example ethanol, or a mixture of a water-miscible organic solvent such as ethanol can be used. Ethanol will play the role of a carrier for salt.

Undesirable bacteria whose growth is prevented according to the invention are extremely sensitive to a decrease in water activity. E. coli and Proteus reduce growth rates, even when the water activity is 0.98, and experience great difficulties in growth with water activity less than 0.95.

Several factors contribute to a decrease in water activity in an absorbent article. The salt content in urine is approximately 1%, which also leads to a decrease in water activity. The salt content in the urine varies greatly during the transition from person to person and from case to case (depending, among other things, on the amount of fluid drunk). In this case, the activity of water will depend on the amount of salt added, on what salt is added, on how much urine is transferred to the pad, and on the intrinsic salt content in the urine.

Salt can be added in such an amount that the activity of the water in the absorbent article is below 0.98. The lower limit for the amount of salt to be added is, for example, 10-30 wt.% Based on the weight of the core and the product for incontinence with a large load. Even such a low content as 1 wt.% In some products can lead to water activity less than 0.98. Higher salt content and therefore lower water activity provide better inhibition of bacterial growth. Urine salt content will also contribute to a decrease in water activity. The upper limit of 75 wt.% (% Dry) is indicated mainly for reasons of production technology.

It was found that a salt content of about 3 wt.% (% When wet) in synthetic urine, test liquid 2 is very beneficial in reducing water activity, in order to reduce ammonia excretion, and to inhibit bacterial growth in absorbent articles. For 1, 2 and 3 wt.% (% Wet) of the added salt in synthetic urine, test fluid 1 or 2, various tests were carried out, which are described later after the examples. Therefore, it is advantageous that the salt concentration in the wetted absorbent article is about 3% by weight (% when wet) of the salt added to the synthetic urine. 1 and 2 wt.% (% When wet) of the added salt also work well.

An absorbent article has a maximum absorption that is different for different products. Therefore, so that when the absorbent product gets wet during use, the amount of added salt is 3%, or 2%, or 1% (wetted), you need to add different amounts of salt depending on which product is used. Products have different weights, different core weights and different maximum absorbency. In order to obtain 3% by weight (wet%) of the salt in the liquid in the absorbent article according to the invention, the maximum absorbency, i.e. the maximum mass of liquid that the absorbent article is capable of absorbing, was calculated and how much salt can be calculated from it add to the absorbent article to achieve a salt content of approximately 3% by weight (% when wet). According to the invention, therefore, an absorbent article is contemplated in which the amount of added salt corresponds to 3 wt.% (% When wet) of the maximum mass of liquid that this product can absorb, for example, if the absorption capacity is 100 ml, then add 3 g of salt. Since the intrinsic salt content in urine is usually about 1 wt.%, Therefore, the final content is about 4 wt.%.

All the tests in the examples were carried out at the maximum load of the products (the largest amount of liquid that the product can absorb). This corresponds to the least favorable situation, that is, the dilution of salt is the maximum. In real-life situations, maximum loading is rarely achieved before replacing the product, i.e. the salt concentration is higher and the effect is greater.

The following are weights for various products. In addition, examples of calculating maximum absorbency are given. Thus, for the respective products, the amount of salt that needs to be added can be easily calculated. The dry weight of the core in women's panty liners is 1-3 g, for feminine sanitary napkins - 3-15 g, for baby diapers - 20-50 g, and for products that protect against incontinence - 10-120 g (from the weakest to maximum protection )

The maximum absorption mass for technical fluff pulp is usually 6 ml / g, and for superabsorbent polymers it is usually 25 ml / g. Then an incontinence preventing product with 54 g (divided into two layers of 17 and 34 g) of technical fluff pulp and 18.5 g of superabsorbent polymer will have a maximum absorbency of 787 ml, i.e. a maximum absorption of 324 ml, for technical fluff pulp and 463 ml for a superabsorbent polymer. If such a product requires an amount of salt corresponding to 3 wt.% (% When wet) of the absorbency, it will be approximately 24 g of salt.

An incontinence product with 47 g (divided into two layers of 14 and 33 g) of technical fluff pulp and 6 g of superabsorbent polymer will have a maximum absorbency of 432 ml. Then 3 wt.% (% Wet) of the added salt, calculated on the basis of the maximum absorbency, will be 13 g of salt. These calculations can be performed for various products by a person skilled in the art, taking into account the core composition and its maximum absorbency.

When placing salt in different areas of the product, its concentration in some areas may be higher. If the product is not loaded as much as possible, the concentration is also higher. And with increasing concentration, the effect is better.

If steam can be transported through a vapor-permeable protective layer, the salt concentration in the absorbent article will increase. One of the following examples shows that the salt concentration overnight for a night diaper with a vapor-permeable protective layer can increase from 2 to 3 wt.% Salt, as can be seen from figure 6. This is a significant change, since the number of bacteria and the release of ammonia decrease with increasing salt concentration from 2 to 3 wt.%, as can be seen from figures 4 and 5.

In the examples, E. coli, P. mirabilis and E. faecalis were selected as suitable test bacteria. All of them are examples of bacteria, the growth of which in large quantities is undesirable in products used for incontinence, for example, during use. For example, they can lead to infections in the urinary tract (UTI). It is often reported that the most common cause of UTI is E. coli. Proteus is also urease-positive, which means that it is able to break down urine to ammonia. Ammonia is a significant cause of unpleasant odors in the use of an incontinence product.

In the case of 3% added salt (% wet) (NaCl high in Figure 4), the growth of all those test bacteria after 14 hours will be below log 5.5. This is a significant difference compared with a control sample and a significant improvement in hygiene.

The vapor permeable backing layer will also contribute to preventing water activity from increasing. In addition, vapor permeable protective layers with greater vapor permeability can be used, since this reduces unpleasant odors from the absorbent article.

The following are examples of various materials from which an absorbent article of the present invention can be made.

The covering layer can be made of fabric material, nonwoven material, polymeric material such as perforated plastic films, foam or mesh foam. Suitable fabric or non-woven materials may include natural fibers (e.g., cellulose or cotton fibers), synthetic fibers (e.g., polymer fibers such as polyesters, polypropylene or polyethylene), or a combination of natural and synthetic fibers. Non-woven materials can be obtained in several different ways, such as the spunbond method, carding, spunbond method, the method of wet canvas, gidrootvanie and a combination of these various methods.

The vapor-permeable protective layer often consists of a plastic film, for example, obtained from polyethylene, polypropylene or from a laminate based on them. By adding a filler, for example titanium dioxide, chalk, or the like, this layer becomes vapor permeable. In addition, this layer can be stretched. You can also use a moisture-permeable material, which is processed so that it becomes moisture-proof. Such processing may include partially coating the surface with a moisture-proof adhesive, coating the surface with a hydrophobic substance, obtaining a laminate from a moisture-permeable layer and a moisture-proof material, calendaring the initially moisture-permeable material in a hot state so that the surface melts and the material thus becomes moisture-proof. The coating is not applied to the entire surface; instead, there are pores through which steam can penetrate. The vapor-permeable but moisture-proof material may also include moisture-proof, vapor-permeable fabrics or laminate materials consisting of several layers of textile material or layers of film and textile material. Examples of substantially moisture-proof but vapor-permeable textile materials are hydrophobic non-woven materials, porous plastic films, porous plastic films, filled cell porous materials, laminated materials consisting of one or more layers of spunbond in combination with meltblown layers, filled films of plastics, layers of waxed material and treated cotton.

The protective layer may have adhesive attachments in the form of bends with an adhesive substance, for example, on the side of the protective layer, which is opposite to the covering layer, so that it can be attached to panties, underpants or panties. When the product is not used, a release agent can be applied over the adhesive to protect the adhesive.

The absorbent core may also consist of one or more layers of cellulose fibers, for example, industrial fluff pulp, dry defibrated airlide, or compressed pulp. Other materials that can be used include, for example, non-woven absorbent material, porous material, synthetic fiber material, or peat. In addition to cellulosic fibers or other absorbent materials, the absorbent core may also include superabsorbent materials (SAP), superabsorbent polymers, which are materials in the form of fibers, particles, granules, films, or the like. Superabsorbent polymers are inorganic or organic substances that are capable of swelling in water and are not soluble in water and which can absorb at least 20 times the amount of an aqueous solution containing 0.9 wt.% Sodium chloride. Organic substances that are suitable as superabsorbent polymers may include natural substances such as polysaccharides, polypeptides and the like, and also synthetic substances such as synthetic hydrogel polymers. Such hydrogel polymers may include, for example, polyacrylic acid, alkali metal salts of polyacrylic acids, polyacrylamides, polyvinyl alcohol, polyacrylates, polyacrylamides, polyvinyl pyridines and so on. Other suitable polymers include a grafted copolymer of hydrolyzed starch and acrylonitrile, a copolymer of starch and acrylic acid, and copolymers of isobutylene and maleic anhydride and mixtures thereof. Hydrogel polymers are preferably readily crosslinked to ensure that the substance remains substantially insoluble in water. Preferred superabsorbent materials can be crosslinked so that the crosslink density of the outer surface or shell, superabsorbent particles, fibers, spheres and so on is higher than that of the inside of the superabsorbent. The proportion of superabsorbents in the absorbent core may be from 10 to 90 wt.% Or preferably from 30 to 70 wt.%.

The absorbent core may contain layers of different materials with different characteristics with respect to their ability to receive liquid, their ability to distribute liquid and their capacities. In most cases, the absorbent core expands in the longitudinal direction and may, for example, be rectangular, in the shape of a T, or in the form of an hourglass. The hourglass-shaped core is wider in the front and back than in the crotch area to ensure effective absorption, while this design makes it easier to shape the product to fit and wrap around the wearer, thus leading to a better fit around the legs .

In addition, the absorbent article may include a transfer layer between the coating layer and the absorbent core. The transfer layer is a porous flexible material and may include one or more of airlide, cotton wool, fabric, carded fiber fabric, superabsorbent particles or superabsorbent fibers. The transfer layer has a high ability to instantly receive liquid and can temporarily hold the liquid until it is absorbed by the absorbent core located beneath it. The transfer layer can cover all parts of the absorbent core.

The coating layer, the protective layer and the intermediate materials are brazed along the edges of the product, which can be accomplished, for example, by thermal soldering or by any other standard methods.

The absorbent article may also have wings on the sides. In addition, it may contain elastic to provide better contact with the body in case the product breaks, as well as to reduce leakage.

Thus, it has been found that salt acts extremely well to inhibit the growth of bacteria in absorbent articles. Absorbent articles often contain superabsorbent materials, and salt is known to have a negative effect on many superabsorbent polymers, although in fact there are superabsorbent polymers that are insensitive to salt. However, the monovalent salt affects them insignificantly and in these cases the positive effect of suppressing bacteria exceeds this consideration. The use of monovalent salt is advantageous if superabsorbent polymers are used in the product. Salt itself is inexpensive and environmentally friendly. In combination with the vapor-permeable protective layer, the positive effects noted above are achieved and increase with increasing salt concentration during use of the absorbent article. At the same salt content and at the same frequency of product replacement, better hygiene is achieved, and since the temperature in the product decreases with the transfer of steam through the protective layer, greater convenience and less growth of microorganisms are achieved. A breathable product is obtained that is convenient for the user, and in addition, the risk of infection during use is reduced.

The invention is further illustrated by the following examples.

Examples

Test fluid 1 is used to determine pH, determine bacterial growth and determine ammonia excretion (reference in Example 2): sterile synthetic urine to which microorganism growth medium was added. Synthetic urine contains monovalent and divalent cations and anions and urea and was obtained according to Geigy, Scientific Tables, vol. 2, 8 ^th ed., 1981, p. 63. Microorganism growth media was prepared based on Hook information and the intestinal bacteria environment FSA. The pH of this mixture is 6.6.

Test liquid 2 is used to determine the activity of water:

Prescription - Synthetic Urine

Magnesium sulfate 0.66 g / l (100 ml of stock solution per 5 liters)

Potassium chloride 4.47 g / l (100 ml of stock solution per 5 liters)

Sodium chloride 7.60 g / l (38.0 g per 5 liters)

Urea (urea) 18.00 g / l (90.0 g per 5 liters)

Potassium dihydrogen phosphate 3.54 g / l (100 ml of stock solution per 5 liters)

Disodium hydrogen phosphate, anhydrous 0.745 g / l (100 ml of the initial solution per 5 liters)

Triton X-100, concentration of 0.1% 1.00 g / l (5.0 g per 5 liters)

Deionized water up to 1 liter (5.0 liter per 5 liter)

Cough red (dye) concentration of 10% 0.4 g / l (2.0 g per 5 liters)

Principle

First, four stock solutions are prepared. The chemicals and stock solutions are mixed to form a solution for use.

Performance

Weighing chemicals requires accuracy so that the solution for use has the proper properties. Prepare stock solutions according to the recipe. Mix the solutions in the order indicated in the recipe.

Stock solutions (shelf life 1 month)

0.274 M magnesium sulfate: dissolve 33 g of magnesium sulfate in deionized water, getting 1 l (per 5 l of the original solution: 165 g MgSO ₄ ).

2.998 M potassium chloride solution: dissolve 223.5 g of potassium chloride in deionized water to obtain 1 L (per 5 L of the original solution: 1117.5 g KCl).

1.3201 M potassium dihydrogen phosphate solution: Dissolve 177 g of potassium dihydrogen phosphate in deionized water to give 1 L (per 5 L of the original solution: 885 g KH ₂ PO ₄ ).

0.262 M disodium hydrogen phosphate solution: Dissolve 37.25 g of disodium hydrogen phosphate in deionized water to give 1 L (per 5 L of the original solution: 186.25 g Na ₂ HPO ₄ ).

Solution for use (shelf life 3 weeks)

Fill the flask 60% with deionized water.

Add Magnesium Sulfate Solution

Add potassium chloride solution

Add Sodium Chloride

When it dissolves, add urea

When it dissolves, add potassium dihydrogen phosphate solution

Add disodium hydrogen phosphate solution

Add Triton X-100

Add deionized water to the exact volume.

Physical properties

The solution for use must have the following numerical values:

Surface energy (surface tension) 60 ± 3 mN / m

Conductivity 23 ± 2 mS

pH 6.0 ± 0.5

Temperature 22 ± 2 ° С

Method 1: Obtaining samples for absorption test for testing

Samples for the absorption test were taken by punching from an absorbent core obtained in a pilot plant. In the production of a core in a pilot plant, a standard method for producing a core matrix was used. The absorption test sample consisted of a homogeneous mixture of fluff pulp pulp, 0.72 g of Weierhauser pulp (NB 416) and 0.48 g of superabsorbent polymer (SAP) (Degussa SXM9135). The absorbent core was pressed into a mass of approximately 8-10 cm ³ / g. The size of the selected test punching method was 5 cm in diameter, the mass was about 1.2 g.

Method 2: Determination of ammonia emission in absorbent cores

Samples for the absorption test were prepared by Method 1. A bacterial suspension of Proteus mirabilis was grown in a nutrient solution at 30 ° C. overnight. The grafted cultures were diluted with test liquid 1 and the number of bacteria was determined. The final culture contained approximately 10 ⁵ organisms in ml of test fluid. The absorbent core was placed in a plastic bath and bacteria containing test liquid 1 was added to the absorbent core, after which the contents were incubated at 35 ° C for 4, 6, and 8 hours, and then the samples were removed from the container using a hand pump and a so-called gas metering tube Drager. The value of the ammonia content was obtained in the form of a color change on a scale graded in parts per million or volume percent.

Method 3: Determination of bacterial growth in absorbent cores

16 ml (corresponding to the maximum absorbency of the test sample according to method 1) of the test liquid 1 containing bacteria were added to the test sample placed in plastic baths, and the baths were covered with lids. The baths were turned upside down and incubated in a warm chamber at 35 ° C. After incubation for 0, 6 and 12 hours, the test samples were placed in a plastic bag with peptone water and the contents were homogenized (mixed and processed) in a stomaker for 3 minutes. The homogenate was diluted in test tubes for dilution with peptone water and the microbiological culture was plated on agar plates. Slanetz Bartley agar agar was used for E. faecalis, and Drigalski agar agar was used for E. coli P. mirabilis. Samples were incubated at 35 ° C for 1-2 days before counting the colonies and calculating log CFU / ml. In addition, control tests with absorbent cores without NaCl were performed.

Method 4: Determination of water activity

Water activity was determined as follows. A device for measuring water activity was obtained from Aqua Lab, Model Series 3 TE, Pentagon Devices Inc. (US patent 5816704). A sample, a solution with different amounts of different salts in Elga-H ₂ O, or in synthetic urine, test liquid 2, was placed in a plastic cup. The quantity is not critical, but it is important that the bottom surface of the plastic cup is closed. The sample is transferred to a test chamber, which is closed and measurements are taken. When the test value becomes constant, a green light flashes, and the digital value of the water activity can be read. The following salts were tested: NaCl, KCl, NH ₄ Cl, KC ₂ H ₃ O ₂ (acetate K), NaC ₂ H ₃ O ₂ (Na acetate).

Example 1. Bacterial growth with the addition of NaCl

Bacteria were grown in nutrient broth and diluted to a desired concentration of approximately Log 3.3 in test fluid 1 (method 4). Samples for the absorption test were prepared by method 1. 29 (high), 22 (medium) and 12 (low) wt.% NaCl (% in dry state) were added to the core, which corresponds to 3 (high), 2 (medium) and 1 (low) wt.% NaCl (% wet) in the wet product. This proportion also applies to other examples. Bacterial growth was determined according to method 4.

The result is presented in figure 4, which clearly shows that the growth of all 3 test bacteria is less after 6 and 12 hours compared with the control tests, but in addition, the inhibition is greater at a higher salt content.

Example 2. The allocation of ammonia when adding NaCl or CaCl ₂

Samples for the absorption test were prepared by Method 1. To the test sample was added 16 ml — the maximum absorption capacity — of test fluid 1 containing bacteria. To the core were added 29 (high), 22 (medium) and 12 (low) wt.% NaCl (% in dry condition) and 22 (average) wt.% CaCl ₂ (% in dry condition). The amount of ammonia recovered was determined by method 3 after 6 and 8 hours. In addition, control tests were carried out using absorption test samples without NaCl or CaCl ₂ .

The results are shown in figure 5. The amount of ammonia released was less for all samples with added salt compared to control samples. Minimum NH ₃ release was observed in the sample containing 29 wt.% NaCl.

Example 3. Determination of salt concentration in combination with a vapor-permeable protective layer

The calculations were based on the product from which the sample was taken by punching, and this sample was 5 cm in diameter and consisted of a coating layer of polypropylene non-woven material, superabsorbent particles (SAP) mixed with fluff pulp and a protective layer of polypropylene Mocon 8000 g / m ² and 24 h, which corresponded to 333 g / m ² and h. A more realistic vapor permeability value was determined at 250 g / m ² and h using a steam meter (SWL 3 NO211 from Delfin Technologies Ltd.). The measurement was carried out using a wet product for 1 h using a steam meter.

16 ml of test fluid 2 containing various amounts of added salt was added to a diaper sample. The surface area of the diaper sample was 1963 × 10 ^-3 m ² and the approximate value of its volatility was 0.5 g / h. 0.48 g, 0.32 and 0.16 g of NaCl were added to samples 1, 2 and 3, respectively. The increase in salt concentration is shown in figure 6.

In case of test 2, the salt concentration was changed from 2 to exactly 3 wt.% (% When wet) for 12 hours, which may correspond to the use of a diaper for one night. An increase in the salt concentration from 2 to 3 wt.% (% In the wet state) leads to a decrease in the emission of ammonia, which can be seen from figure 5, and to a decrease in the growth of bacteria, which can be seen from figure 4. For all the studied values of the salt concentration, the salt concentration increased when measured after 6 hours and 12 hours.

Example 4. Determination of water activity at a 3% concentration of salt solutions

The water activity was determined in Elga-H ₂ O (USF Elga, distilled water) and the synthetic urine test liquid 2. To show that the addition of salt leads to decrease of water activity Water activity was determined for different salts in water and Elga test liquid 2. When determining the activity of water in test liquid 2 with its own salt content, the measured water activity was 0.984. In the case of Elga water, the measured water activity was 0.999. 3 wt.% Of various salts were added to test liquid 2 and Elga water, and water activity was determined by method 4.

An obvious decrease in water activity is shown in Figure 7. After adding 3% salt, the activity of water in test liquid 2 is less than 0.975.

Example 5. The activity of water at different concentrations of NaCl, Na acetate, NH _four Cl

Water activity was determined by method 4, but at different salt concentrations in Elga-H ₂ O. Figure 8 clearly shows the decrease in water activity with increasing salt concentration.

Claims (15)

1. An absorbent product, such as a diaper, absorbent panties, a sanitary napkin, or an incontinence product with a vapor-permeable protective layer, including a moisture-permeable covering layer, intended to be turned towards the user upon use, a moisture-proof but vapor-permeable protective a layer intended for circulation in the opposite direction from the user during use, and an absorbent core between the coating layer and the protective layer, while the specified product them there is a longitudinal direction (2), a transverse direction (3), two essentially longitudinal lateral edges (4, 5), one essentially transverse front edge (7), one essentially transverse rear edge (8) , one substantially longitudinal center line (6), front part (9) and rear part (10) on each side of the substantially transverse center line (11), wherein said center line (6) and center line (11) intersect each other at the point of intersection (12), characterized in that the absorbent article contains at least one monovalent salt of the form X ⁺ Y ^- in an amount of 1-75 wt.% based on the weight of the core, where X ^{+ is} chosen from the number of Na ⁺ , K ⁺ , NH ₄ , and Y ^{- is} selected from among the Cl ^- , C ₂ H ₃ O ₂ ^- and C ₃ N _s O ₂ ^- . 2. Absorbent product according to claim 1, characterized in that the salt is distributed in the central region around the intersection point (12). 3. Absorbent product according to claim 1 or 2, characterized in that said region extends at least 1.5 cm from the center line (11) in the longitudinal direction (2) and at least 1.5 cm from the midline (6) in the transverse direction (3). 4. The absorbent product according to claim 1, characterized in that the vapor permeability of the vapor permeable protective layer is at least 500 g / m ² and 24 hours 5. Absorbent product according to claim 1, characterized in that the salt is distributed inside the absorbent core. 6. Absorbent product according to claim 1, characterized in that the salt is distributed in the upper part of the absorbent core. 7. Absorbent product according to claim 1, characterized in that the absorbent product also contains a distribution layer. 8. The absorbent product according to claim 1, characterized in that the spreading layer is located between the covering layer and the absorbent core. 9. The absorbent product according to claim 1, characterized in that the distribution layer is located between the absorbent core and the protective layer. 10. The absorbent product according to claim 1, characterized in that the distribution layer is located inside the absorbent core. 11. The absorbent product according to claim 1, characterized in that the particle size of the salt is from 50 to 1500 microns. 12. The absorbent product according to claim 1, characterized in that the salt is added in the form of flakes and the width of these flakes is up to 1 cm 13. Absorbent product according to claim 1, characterized in that the salt is added in the form of a pure salt. 14. The absorbent product according to claim 1, characterized in that the salt is added in such an amount that the activity of water in the absorbent product when wet is less than 0.98. 15. Absorbent product according to claim 1, characterized in that the salt is added in such an amount that the concentration of each of E. coli, P. mirabilis and E. faecalis in the product can be maintained below 6.5 Log CFU / ml through 10 hours after moistening with synthetic urine.

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